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Zhao JY, Chi ZL, Song JJ, Lu SP, Zhang YN, Lei CK, Shu CM. Study on the thermal behaviour of spontaneous combustion of open-pit minerals. Sci Total Environ 2024; 929:172477. [PMID: 38621544 DOI: 10.1016/j.scitotenv.2024.172477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/28/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
To study thermal behaviour during spontaneous combustion of an open-pit coal mine, mixed slag (coal, oil shale, and coal gangue) was taken as the research object. Laser thermal conductivity analyser and differential scanning calorimetry were used to test thermophysical parameters and heat release characteristics of the minerals. The parameters can be employed to calculate the apparent activation energy using the Arrhenius equation and evaluate the thermal behaviour of open-pit mixed slag. The results indicate that thermophysical parameters have stage characteristics. Thermal diffusivity and thermal conductivity of minerals, especially mixed slag, have a strong correlation with temperature. Heat flow of minerals exhibits five characteristic stages, and heat flow of the samples is consistent with the change in heating rate. During the heating process, thermal diffusivity and heat flow of the mixed slag are between those of a single mineral. Except for the mixed slag at 15 and 20 °C/min, the initial exothermic temperature of the other samples is mainly concentrated at 50-80 °C. Thermal energy release of the sample is mainly concentrated in the accelerated exothermic stage and rapid exothermic stage. Thermal energy release of mixed slag in rapid exothermic stage is always greater than that in accelerated exothermic stage, and the proportion of thermal energy release in these two stages exceeds 98 %. The apparent activation energy during the accelerated exothermic stage is lower, making it easier to release heat, and rapid exothermic stage is relatively high, which can readily lead to heat accumulation. Thermal analysis reveals that the thermal behaviour of mixed slag is significantly different from that of a single mineral. Its unique exothermic characteristics can provide a more accurate theoretical basis for the prevention and control of environmental pollution caused by slag spontaneous combustion.
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Affiliation(s)
- Jing-Yu Zhao
- School of Safety Science and Engineering, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China
| | - Zhao-Long Chi
- School of Safety Science and Engineering, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China
| | - Jia-Jia Song
- School of Safety Science and Engineering, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China.
| | - Shi-Ping Lu
- School of Safety Science and Engineering, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China
| | - Yan-Ni Zhang
- School of Safety Science and Engineering, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China; Shaanxi Key Laboratory of Prevention and Control of Coal Fire, Xi'an University of Science and Technology, No. 58, Yanta Mid. Rd., Xi'an, Shaanxi 710054, PR China
| | - Chang-Kui Lei
- School of Safety and Emergency Management Engineering, Taiyuan University of Technology, No. 79, Yingze West Street, Taiyuan, Shanxi 030024, PR China
| | - Chi-Min Shu
- Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology, 123, University Rd., Sec. 3, Douliou, Yunlin 64002, Taiwan
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Kumar A, Kumar M, Mahboob MR, Srivastava B. Influence of °Brix/Acid, and flow rate of pineapple juice and electric field strength on the performance of continuous ohmic heating system. J Food Sci Technol 2024; 61:1188-1200. [PMID: 38562592 PMCID: PMC10981646 DOI: 10.1007/s13197-024-05961-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 01/24/2024] [Accepted: 02/22/2024] [Indexed: 04/04/2024]
Abstract
A lab-scale continuous ohmic heating (COH) system was developed, and its performance was studied for pineapple juice heating as a model sample. The effect of independent parameters [°Brix/Acid (unstandardized, 18, 22, 26) and flow rate (80-120 mL/min) of juice and electric field strength (EFS: 25-45 V/cm)] were analysed for responses viz. come-up-time, heating rate (HR) and system performance coefficient (SPC). The full factorial experimental design was used for this study. The results showed that with an increase in °Brix/Acid, the % acidity and electrical conductivity decreased significantly (p < 0.05); thus, the come-up-time to reach 90 °C increased significantly. The HR was significantly (p < 0.05) influenced by °Brix/Acid and EFS but less so by flow rates at higher EFS. The SPC was more than 0.90 and reduced significantly (p < 0.05) with an increase in °Brix/Acid and flow rate. The HR was modeled using a feed-forward back-propagation artificial neural network (ANN) with the best topology of 3, 5, and 1 neurons in the input (independent), hidden, and output (response) layers, respectively. The model performed efficiently, which is evident from the high R2 (0.998) and low RMSE (1.255). Thus, the COH, with its high efficiency and HR, can effectively be used to process fruit juice. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s13197-024-05961-x.
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Affiliation(s)
- Amardeep Kumar
- Department of Food Engineering and Technology, School of Engineering, Tezpur University, Napam, Assam 784028 India
| | - Manibhushan Kumar
- Department of Food Engineering and Technology, School of Engineering, Tezpur University, Napam, Assam 784028 India
| | - Md. Rahat Mahboob
- Department of Electrical Engineering, School of Engineering, Tezpur University, Tezpur, Assam 784028 India
| | - Brijesh Srivastava
- Department of Food Engineering and Technology, School of Engineering, Tezpur University, Napam, Assam 784028 India
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Ferrero L, Losi N, Rigler M, Gregorič A, Colombi C, D'Angelo L, Cuccia E, Cefalì AM, Gini I, Doldi A, Cerri S, Maroni P, Cipriano D, Markuszewski P, Bolzacchini E. Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter. Sci Total Environ 2024; 917:170221. [PMID: 38280585 DOI: 10.1016/j.scitotenv.2024.170221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/27/2023] [Accepted: 01/14/2024] [Indexed: 01/29/2024]
Abstract
Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m-3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (-0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia; Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia
| | - C Colombi
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - L D'Angelo
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy; Institute for Atmospheric and Environmental Sciences, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany
| | - E Cuccia
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - A M Cefalì
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - I Gini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - A Doldi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cerri
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - P Maroni
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - D Cipriano
- RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - P Markuszewski
- Institute of Oceanology, Polish Academy of Sciences, 81-712 Sopot, Poland; Bolin Centre for Climate Research and Department of Environmental Science, Stockholm University, 10691 Stockholm, Sweden
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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Tito E, Marcolongo CA, Pipitone G, Monteverde AHA, Bensaid S, Pirone R. Understanding the effect of heating rate on hydrothermal liquefaction: A comprehensive investigation from model compounds to a real food waste. Bioresour Technol 2024; 396:130446. [PMID: 38367926 DOI: 10.1016/j.biortech.2024.130446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/30/2024] [Accepted: 02/09/2024] [Indexed: 02/19/2024]
Abstract
Hydrothermal liquefaction (HTL) emerges as an efficient technology for converting food waste into biocrude. Among HTL parameters, the impact of heating rate is understudied. This study systematically explores its variation (5-115 K/min) on HTL performance using actual food waste and model compounds representing its constituents. Results revealed that an increase in heating rates significantly impacts HTL performances (+63 % biocrude and -34 % solid with food waste) with short residence times, as slower heating rates imply a longer overall time and a higher kinetic advancement of the reaction. Conversely, with longer residence times, the influence of heating rates becomes negligible, as kinetics during heating times are overshadowed by those at operating temperatures. A subtle effect of heating variation at extended residence time was observed only with carbohydrates. This research emphasizes the utility of a kinetic severity factor (KSF) as a valuable tool for simultaneously considering heating rates, operating times, and temperatures.
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Affiliation(s)
- Edoardo Tito
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Carlo Alberto Marcolongo
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Giuseppe Pipitone
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
| | - Alessandro H A Monteverde
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Samir Bensaid
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Raffaele Pirone
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
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Hu Y, Li M, Zhou N, Yuan H, Guo Q, Jiao L, Ma Z. Catalytic stepwise pyrolysis for dechlorination and chemical recycling of PVC-containing mixed plastic wastes: Influence of temperature, heating rate, and catalyst. Sci Total Environ 2024; 908:168344. [PMID: 37951271 DOI: 10.1016/j.scitotenv.2023.168344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/27/2023] [Accepted: 11/03/2023] [Indexed: 11/13/2023]
Abstract
The viability of pyrolysis technology for chemical recycling of plastics is challenged by the presence of PVC in real-world mixed plastic wastes. This study aims to investigate catalytic stepwise pyrolysis as a pretreatment step to remove chlorine from PVC-containing plastic wastes prior to further processing. TG-FTIR and Py-GCMS analysis as well as experiments on a lab-scale pyrolysis system were conducted to study the influence of key processing parameters on the pretreatment including temperature, heating rate, and catalysts. Py-GCMS results indicated 300 °C to be the best pretreatment temperature in terms of balancing Cl removal and avoidance of organochloride formation. Metal oxides, i.e., CaO and Fe2O3, mainly acted as adsorbents of HCl gases with little cracking effect, and their adsorption effects are positively correlated with alkalinity. ZSM-5 catalysts promoted the release of HCl, and the dechlorination effect was more pronounced with ZSM-5 of higher acidity. In contrast, in the lab-scale pyrolysis system, 350 °C pretreatment achieved the highest HCl generation ratio, i.e., 43.60 %. The addition of zeolite catalyst significantly reduced the content of organochloride in the pyrolysis oil in contrast to the performance of metal oxides, but also absorbed most HCl instead of promoting HCl release as in Py-GCMS tests. Mass balance analyses revealed that the majority of chlorine was retained in the solid residues following the catalytic stepwise pyrolysis process, with the notable exception of Fe2O3. ZSM-5(25) catalyst combined with 350 °C pretreatment temperature and 550 °C final pyrolysis achieved the lowest chlorine content in the pyrolysis oil, i.e., 20 ppm, among different process conditions.
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Affiliation(s)
- Yanjun Hu
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China; Zhejiang Carbon Neutral Innovation Institute, Zhejiang University of Technology, Chaowang Road 18#, 310024 Hangzhou, China
| | - Mingzhe Li
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Nan Zhou
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China.
| | - Hao Yuan
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Qianqian Guo
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Long Jiao
- Institute of Thermal and Power Engineering, Zhejiang University of Technology, Liuhe Road 288#, 310023 Hangzhou, China
| | - Zengyi Ma
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, 310013 Hangzhou, China
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Nath B, Chen G, Bowtell L, Graham E. Kinetic mechanism of wheat straw pellets combustion process with a thermogravimetric analyser. Heliyon 2023; 9:e20602. [PMID: 37822613 PMCID: PMC10562926 DOI: 10.1016/j.heliyon.2023.e20602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/09/2023] [Accepted: 09/30/2023] [Indexed: 10/13/2023] Open
Abstract
In this study, the combustion characteristics of two wheat straw pellets (WSP) (T1: 100% wheat straw and T5: 70% wheat straw; 10% sawdust, 10% biochar; 10% bentonite clay) were performed at a heating rate 20 °C/min under a temperature from 25 to 1200 °C in air atmosphere. A thermogravimetric analyser (TGA) was used to investigate the activation energy (Eα), pre-exponential factor (A), and thermodynamic parameters. The DTG/TG profile of WSP was evaluated by model-free and model-based methods and found the model-based method was suitable for WSP thermal characterisation. The result demonstrates that the thermal decomposition occurred in four stages, comprising four consecutive reaction steps. A→B→C→D→E→F. Further, the model-based techniques were best fitted with kinetic reaction models like Cn (nth-order reaction with auto-catalyst), Fn (reaction of nth order), F2 (second-order phase interfacial reaction) and D3 (diffusion control). The average Eα for Fn, Cn, D3 and F2 models were 164.723, 189.782, 273.88, and 45.0 kJ/mol, respectively, for the T1 pellets. Alternatively, for T5 pellets, the A was 1.17E+2, 1.76E+16, 5.5E+23, and 1.1E+3 (1/s) for F2, D3, Cn and Fn models. Overall, the thermodynamic properties showed that WSP thermokinetic reactions were complex and multi-point equilibrium, indicating a potentiality as a bioenergy feedstock.
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Affiliation(s)
- Bidhan Nath
- School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Guangnan Chen
- School of Agriculture and Environmental Science, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Les Bowtell
- School of Engineering, University of Southern Queensland, Toowoomba, QLD, 4350, Australia
| | - Elizabeth Graham
- Physical and Mechanical properties Laboratory, Central Analytical Research Facility, Queensland University of Technology, Brisbane, QLD, 4000, Australia
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Han G, Du Y, Du L. Effects of heating rate and shell colour on the cardiac thermal performance in a polymorphic gastropod Batillaria attramentaria. Mar Environ Res 2023; 189:106045. [PMID: 37295309 DOI: 10.1016/j.marenvres.2023.106045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/31/2023] [Accepted: 06/03/2023] [Indexed: 06/12/2023]
Abstract
Heating rate has gained extensive attention in mechanistic understanding of physiological responses to changing thermal conditions in the context of climate change. In polymorphic gastropods, differences in the absorption of solar energy between dark- and light-coloured individuals lead to supposable differences in their heating rates and body temperatures in sunshine. In the present study, we examined the effect of heating rate on heart rate (HR) in a polymorphic gastropod Batillaria attramentaria. By using biomimetic models, we found that daily maximum temperature of snails with a dark unbanded shell (D-type morph) was higher than snails with a white line on the upper side of each whorl (UL-type morph) by 0.6 °C when exposed to sunlight, but there was no apparent difference in heating rates between D- and UL-type models. We measured HR of snails at various heating rates from 3.0 to 9.0 °C h-1. Faster heating rates significantly increased maximum thermal tolerance in both D- and UL-type snails, highlighting the importance to have thorough knowledge on the heating rate in the field to obtain accurate maximum thermal limit of gastropods. Critical temperature at which HR precipitously declines was higher in D-type snails than UL-type snails. Our results suggested that the impacts of heating rate as well as the shell colour should be considered to gain a mechanistic understanding of the population dynamics of polymorphic gastropods.
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Affiliation(s)
- Guodong Han
- College of Life Science, Yantai University, Shandong, 264005, China.
| | - Yinghui Du
- College of Life Science, Yantai University, Shandong, 264005, China
| | - Lina Du
- College of Life Science, Yantai University, Shandong, 264005, China
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Gu X, Cao T, Mou J, Liu J. Water bath is more efficient than hot air oven at thermal inactivation of coronavirus. Virol J 2023; 20:84. [PMID: 37131169 PMCID: PMC10153051 DOI: 10.1186/s12985-023-02038-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 04/11/2023] [Indexed: 05/04/2023] Open
Abstract
BACKGROUND Thermal inactivation is a conventional and effective method of eliminating the infectivity of pathogens from specimens in clinical and biological laboratories, and reducing the risk of occupational exposure and environmental contamination. During the COVID-19 pandemic, specimens from patients and potentially infected individuals were heat treated and processed under BSL-2 conditions in a safe, cost-effective, and timely manner. The temperature and duration of heat treatment are optimized and standardized in the protocol according to the susceptibility of the pathogen and the impact on the integrity of the specimens, but the heating device is often undefined. Devices and medium transferring the thermal energy vary in heating rate, specific heat capacity, and conductivity, resulting in variations in efficiency and inactivation outcome that may compromise biosafety and downstream biological assays. METHODS We evaluated the water bath and hot air oven in terms of pathogen inactivation efficiency, which are the most commonly used inactivation devices in hospitals and biological laboratories. By evaluating the temperature equilibrium and viral titer elimination under various conditions, we studied the devices and their inactivation outcomes under identical treatment protocol, and to analyzed the factors, such as energy conductivity, specific heat capacity, and heating rate, underlying the inactivation efficiencies. RESULTS We compared thermal inactivation of coronavirus using different devices, and have found that the water bath was more efficient at reducing infectivity, with higher heat transfer and thermal equilibration than a forced hot air oven. In addition to the efficiency, the water bath showed relative consistency in temperature equilibration of samples of different volumes, reduced the need for prolonged heating, and eliminated the risk of pathogen spread by forced airflow. CONCLUSIONS Our data support the proposal to define the heating device in the thermal inactivation protocol and in the specimen management policy.
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Affiliation(s)
- Xinxia Gu
- Laboratory of Infectious Diseases and Vaccine, West China School of Medicine, West China Hospital, Sichuan University, 88 Keyuan S. Rd, Chengdu, 610041, China
| | - Ting Cao
- Laboratory of Infectious Diseases and Vaccine, West China School of Medicine, West China Hospital, Sichuan University, 88 Keyuan S. Rd, Chengdu, 610041, China
| | - Jun Mou
- Laboratory of Infectious Diseases and Vaccine, West China School of Medicine, West China Hospital, Sichuan University, 88 Keyuan S. Rd, Chengdu, 610041, China
| | - Jie Liu
- Laboratory of Infectious Diseases and Vaccine, West China School of Medicine, West China Hospital, Sichuan University, 88 Keyuan S. Rd, Chengdu, 610041, China.
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Li C, Xia H, Liu C, Zeng K, Zhang L. Analysis of the effect of heating rate on pyrolysis kinetics and product composition of copper-containing waste circuit boards. Environ Sci Pollut Res Int 2023; 30:33075-33089. [PMID: 36471150 DOI: 10.1007/s11356-022-24524-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Pyrolysis is a cost-effective and environmentally benign method for recycling organic waste, which can be converted into high-energy gases and oils. Pyrolysis technology was employed in this study to recycle copper-containing discarded circuit board material and recover copper, glass fibers, and gases and oils with high calorific values. Thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectrometry (GC-MS) were used to evaluate pyrolyses of copper-containing waste circuit board materials conducted at different heating rates (5, 10, 20, and 40 °C/min), and the resulting volatiles were studied in detail. The effects of heating rate on the kinetics and activation energies for pyrolyses of copper-containing waste circuit boards were also investigated by using the Coats-Redfern (C-R) method. The TGA curves and FTIR spectra did not differ significantly for different heating rates, and the main functional groups identified with the FTIR results were O-H, C = C, aromatic benzene, substituted benzene, and C-Br. Additionally, GC-MS analyses showed that the heating rate had a great influence on the pyrolysis products formed; the phenol content decreased with increasing heating rate, and the highest content was realized at 5 ℃/min. Energy dispersive spectroscopy (EDS) analyses showed that bromine was removed from the solid phase products during pyrolysis, while copper was effectively enriched in the feedstock. This indicated that pyrolysis can be used to recover copper-containing waste circuit boards.
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Affiliation(s)
- Chunyu Li
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
| | - Hongying Xia
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China.
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China.
| | - Chengfei Liu
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Copper Co., Ltd, Kunming, 650000, China
| | - Kangqing Zeng
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
| | - Libo Zhang
- Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
- Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, 650093, Yunnan, China
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, 650093, Yunnan, China
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10
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Ansari K, Ramachandran S. Radiative effects of absorbing aerosol types over South Asia. Sci Total Environ 2023; 858:159969. [PMID: 36347289 DOI: 10.1016/j.scitotenv.2022.159969] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/21/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
A comprehensive study on classifying the aerosol types and absorbing aerosol types, and quantifying the effect of absorbing aerosols on aerosol optical and radiative properties using four years (2015-2016, 2018-2019) of high-quality Aerosol Robotic Network (AERONET) datasets over Kanpur (urban) and Gandhi College (rural) in the Indo-Gangetic Plain (IGP) region is conducted on a seasonal scale, for the first time. Biomass burning (BB), urban-industrial, and mixed aerosol types are always present, whereas dust aerosol and mostly dust absorbing aerosol types are only present in pre-monsoon and monsoon seasons. During winter and post-monsoon seasons, BB aerosols and mostly black carbon (MBC) absorbing aerosols dominate, and the contribution of aerosol optical depth (AOD) and single scattering albedo (SSA) corresponding to MBC to total AOD and SSA are higher. SSA for MBC varies over a broader range due to mixing of BC with water-soluble aerosols. During pre-monsoon and monsoon seasons, mixing of dust with anthropogenic aerosols increases the amount of mixed aerosol type. Surface cooling and atmospheric heating efficiency for mixed aerosols are higher than MBC and dust aerosols due to enhancement in aerosol absorption over both locations. Seasonal analysis of aerosol radiative properties showed that during winter and post-monsoon, MBC absorbing aerosols are the major contributor in controlling/influencing the total aerosol radiative forcing (ARF) and heating rate (HR). During the other seasons, each absorbing aerosol type significantly influences ARF depending on their AOD and SSA values. In addition to Kanpur and Gandhi College, data from seven other AERONET sites located at Karachi, Lahore, Jaipur, Lumbini, Pokhara, Bhola, and Dhaka in South Asia are analysed to conduct a regional-scale examination of aerosol optical parameters and radiative effects due to different absorbing aerosol types. As the aerosol characteristics and trends are similar over these sites, the findings from such a regional-scale analysis can be an appropriate representative for the South Asian region. The regional analysis revealed that the annual mean atmospheric ARF (ARFATM) and ARF efficiency (ARFEATM), and HR are higher for MBC, followed by mixed and MD aerosols over South Asia due to higher AOD, and higher absorbing efficiency of MBC aerosols. In comparison, mixed aerosols exhibit higher ARFATM over East Asia. This quantification of absorbing aerosol types over a global aerosol hotspot will be useful for an accurate quantification of climate impacts of aerosols.
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Affiliation(s)
- Kamran Ansari
- Physical Research Laboratory, Ahmedabad, 380009, India; Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, 382055, India.
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11
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Ningombam SS, Khatri P, Larson EJL, Dumka UC, Sarangi C, Vineeth R. Classification of MODIS fire emission data based on aerosol absorption Angstrom exponent retrieved from AERONET data. Sci Total Environ 2023; 858:159898. [PMID: 36343809 DOI: 10.1016/j.scitotenv.2022.159898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
Biomass burning emits a large quantity of gaseous pollutants and aerosols into the atmosphere, which perturbs the regional and global climate and has significant impacts on air quality and human health. In order to understand the temporal and spatial distributions of biomass burning and its contribution to aerosol optical and radiative impacts, we examined fire emission data and its contribution to aerosol optical and radiative impacts over six major hot-spot continents/sub-continents across the globe, namely North-Central (NC) Africa, South America, US-Hawaii, South Asia, South East Asia, and Australia-New Zealand, using long-term satellites, ground-based and re-analysis data during 2000-2021. The selected six sites contributed ∼70% of total global fire data. The classification of biomass burning, such as pre, active, and post burning phases, was performed based on the Absorption Angstrom Exponent (AAE) estimated from 55 AERONET (AErosol RObotic NETwork) stations. The study found the highest contribution of fire count (55 %) during the active burning phase followed by post (36 %) and pre (8 %) burning phases. Such high fire counts were associated with high absorption aerosol optical depth (AAOD) during the active fire event. Strong dominance of fine and coarse mode mixed aerosols were also observed during active and post fire regimes. High AAOD and low Extinction Angstrom Exponent (EAE) over NC Africa during the fire events suggested presence of mineral dust mixed with biomass burning aerosols. Brightness temperature, fire radiative power and fire count were also dominated by the active burning followed by post and pre burning phases. The maximum heating rate of 3.15 K day-1 was observed during the active fire events. The heating rate profile shows clear variations for three different fire regimes with the highest value of 1.80 K day-1 at ∼750 hPa altitude during the active fire event.
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Affiliation(s)
| | - Pradeep Khatri
- Center for Atmospheric and Oceanic Studies (CAOS), Graduate School of Science, Tohoku University, Japan
| | | | - Umesh Chandra Dumka
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, India
| | - Chandan Sarangi
- Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, India
| | - R Vineeth
- Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, India
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12
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Zhang W, Jia J, Ding Y, Jiang G, Sun L, Lu K. Effects of heating rate on thermal degradation behavior and kinetics of representative thermoplastic wastes. J Environ Manage 2022; 314:115071. [PMID: 35430512 DOI: 10.1016/j.jenvman.2022.115071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/07/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
Waste thermoplastics are the most common solid wastes, and thermal degradation has excellent advantages in the disposal of these wastes and obtaining valuable hydrocarbon fuels. As a significant factor, the heating rate is crucial to the thermal degradation process. Consequently, thermal degradation behavior and kinetics of representative thermoplastics under different heating rates were investigated by using thermogravimetric analysis and differential scanning calorimetry in the air. Kinetic parameters were estimated by using the Coats-Redfern method. Subsequently, the Shuffled Complex Evolution (SCE) method was used to optimize kinetic parameters, and the optimized results were compared with the calculated kinetics of distributed activation energy model (DAEM) method to find the effects of heating rate on kinetic parameters. The results showed that with the increase of heating rate, thermogravimetric curves moved to the right, which corresponded to a higher temperature range. The number of mass loss rate peaks and exothermic peaks decreased. Additionally, activation energy was the same at the determined minimum and maximum heating rates, and other heating rates had little effect on kinetic parameters. Moreover, the calculated activation energy of the DAEM method at the minimum heating rate of 5 K/min was closest to the optimized values of the SCE method, indicating that the lower the minimum heating rate was, the more accurate the activation energy was.
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Affiliation(s)
- Wenlong Zhang
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Jia Jia
- Naval Research Institute, Beijing, 100161, China
| | - Yanming Ding
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China.
| | - Gonghua Jiang
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Lulu Sun
- Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Kaihua Lu
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
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13
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Manić N, Janković B, Stojiljković D, Angelopoulos P, Radojević M. Thermal characteristics and combustion reactivity of coronavirus face masks using TG-DTG-MS analysis. J Therm Anal Calorim 2022; 147:10131-10143. [PMID: 35528133 PMCID: PMC9062285 DOI: 10.1007/s10973-022-11358-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
The presented paper deals with the influence of the heating rate on combustion characteristics (reactivity and reactivity evaluation, ignition index (D i), burnout index (D f), the combustion performance index (S), and the combustion stability index (R W)) of the protective coronavirus face masks. Two types of commonly used face masks in different state (new and exploited) were investigated by TG-DTG analysis in an air atmosphere, directly coupled with mass spectrometry (MS). Based on the experimental results, the impact of ultimate and proximate analysis data on the evolved gas analysis (EGA) was discussed. Also, the derived values from thermo-analytical (TA) data were compared with the literature reports, related to individual constitutive face mask materials. According to the performed research, it was established that different maximal reaction rate values at various heating rates indicate the complex nature of coronavirus face mask thermo-oxidative degradation, which is stimulated with carbon oxidation reactions and volatile matter (VM) release. By detailed analysis of obtained TG-DTG profiles, it was established that process takes place through the multiple-step reaction pathways, due to many vigorous radical reactions, causes by polymers degradation. The performed research was done to evaluate the possible utilization of coronavirus waste to energy production and sustainable pandemic environmental risk reduction.
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Affiliation(s)
- Nebojša Manić
- Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, University of Belgrade, Belgrade, Serbia
| | - Bojan Janković
- Department of Physical Chemistry, Vinča Institute of Nuclear Sciences - National Institute of The Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Dragoslava Stojiljković
- Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, University of Belgrade, Belgrade, Serbia
| | - Panagiotis Angelopoulos
- School of Mining and Metallurgical Engineering, National Technical University of Athens, Athens, Greece
| | - Miloš Radojević
- Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, University of Belgrade, Belgrade, Serbia
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14
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Jeong J, An S, Kim T, Joung W. Transient Thermal Characteristics of a Heated Infrared Temperature Sensor for Noncontact Medical Thermometry. Int J Thermophys 2022; 43:62. [PMID: 35194282 PMCID: PMC8853165 DOI: 10.1007/s10765-022-02990-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
In this work, the transient responses of a heated infrared (IR) temperature sensor were investigated to improve the reliability of determined target temperatures obtained from IR-based medical thermometers. A medical-grade IR temperature sensor was heated at the lower edge of the sidewall of the sensor. To reduce the uncertainty due to the conversion factor of the thermal detector, the temperature of the target, which was a thermostatted blackbody source, was determined when the observed target temperature and the temperature of the detector coincided during the heating and cooling of the sensor. When the determined target temperature was compared with the blackbody source temperature, it was found that during heating, due to the produced temperature gradient in the sensor, the observed target temperature showed erroneous depressions, resulting in the determined target temperature being considerably lower than the true target temperature. In contrast, the determined target temperature during cooling of the heated sensor was consistent with the tested blackbody source temperatures within the claimed uncertainty at all heating conditions. Therefore, based on the obtained results, it was concluded that temperature measurements using an IR temperature sensor could be carried out with the least uncertainty by determining the target temperature when the observed target and detector temperatures coincided during cooling of the heated sensor.
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Affiliation(s)
- Jaehyuk Jeong
- Department of Intelligent Robot Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
| | - Sujin An
- Department of Mechanical Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
| | - Taewan Kim
- Department of Intelligent Robot Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
- Department of Mechanical Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
| | - Wukchul Joung
- Department of Intelligent Robot Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
- Department of Mechanical Engineering, Pukyong National University, 45 Yongso-ro, Nam-gu, Busan, 48513 Republic of Korea
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15
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Milošević D, Savić S, Kresoja M, Lužanin Z, Šećerov I, Arsenović D, Dunjić J, Matzarakis A. Analysis of air temperature dynamics in the "local climate zones" of Novi Sad (Serbia) based on long-term database from an urban meteorological network. Int J Biometeorol 2022; 66:371-384. [PMID: 33389147 DOI: 10.1007/s00484-020-02058-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 11/11/2020] [Accepted: 11/20/2020] [Indexed: 05/29/2023]
Abstract
A comprehensive analysis of air temperature (Ta) dynamics in "local climate zones" (LCZs) of Novi Sad (Serbia) was based on measurements from 17 stations during 3 years. Hourly changes of Ta, cooling rates (CR), heating rates (HR), and urban heat island (UHI) intensity were assessed on seasonal and annual level and during heat wave (HW) and cold wave (CW) periods. Substantial differences are observed for minimum (Tmin) and mean temperatures (Tmean) between LCZs. Two-phase nocturnal cooling was recognized with the first cooling phase characterized by intensive LCZ dependent cooling starting at 1-3 h before sunset and lasting until 3-4 h after sunset. The second cooling phase lasts until sunrise and is characterized by less intensive and LCZ nondependent cooling. The most intensive cooling (CRpeak) was observed in first cooling phase of HW and ranged from - 1.6 °C h-1 in street canyon (LCZ 2) to - 3.9 °C h-1 in forest (LCZ A). Furthermore, a new cooling indicator (CRtotal) was introduced. Due to cooling differences, the most intensive UHI of 5.5 °C was noticed between LCZs 2 and A at sunset + 1 h during HW. Two-phase diurnal heating was also recognized in LCZs with the first heating phase characterized by intensive LCZ dependent heating starting at sunrise and lasting until 4-7 h afterwards. The most intensive heating (HRpeak) ranged from 2.0 °C h-1 in street canyon to 3.0 °C h-1 in industrial area (LCZ 8) during HW. The second heating phase lasts until sunset and is characterized by less intensive heating and smaller HR differences between LCZs.
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Affiliation(s)
- Dragan Milošević
- Climatology and Hydrology Research Centre, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia.
| | - Stevan Savić
- Climatology and Hydrology Research Centre, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Milena Kresoja
- Institute of Economic Sciences, Zmaj Jovina 12, Belgrade, 11000, Serbia
| | - Zorana Lužanin
- Department of mathematics and informatics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Ivan Šećerov
- Climatology and Hydrology Research Centre, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Daniela Arsenović
- Climatology and Hydrology Research Centre, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Jelena Dunjić
- Department of Geography, Tourism and Hotel Management, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Andreas Matzarakis
- Research Centre Human Biometeorology, German Meteorological Service, Stefan-Meier-Str. 4, D-79104, Freiburg, Germany
- Environmental Meteorology, Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, Werthmann strasse 10, D-79085, Freiburg, Germany
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16
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Zhou L, Tey CY, Bingol G, Balaban MO, Cai S. Effect of different microwave power levels on inactivation of PPO and PME and also on quality changes of peach puree. Curr Res Food Sci 2022; 5:41-48. [PMID: 35028593 PMCID: PMC8715141 DOI: 10.1016/j.crfs.2021.12.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 11/29/2022] Open
Abstract
The effect of microwave (MW) treatment with different power densities (4.4, 7.7, and 11.0 W/g) on polyphenol oxidase (PPO) and pectin methyl esterase (PME) inactivation in peach puree were studied, and the changes in color, rheological properties, total polyphenol and flavonoid and antioxidant capacity were evaluated. By using time/temperature data collected during MW heating, three cook values levels (0.36, 10, 24 min) for each power density were calculated. The PPO was significantly decreased from ca. 50% to ca. 5% when increasing the cook value level, regardless of power density applied. While PME significantly decreased from 40.6% to 10.2% when power density increased from 4.4 to 11.0 W/g at cook value 24 min. MW treatment did not alter the flow behaviour of peach puree. The apparent viscosity values of peach puree significantly increased after MW treatment with increasing cook value, regardless of power density applied. The L* values of peach puree significantly increased from 36.98 to 38.10 or more after MW treatment at cook value 10 min and 24 min. MW treatment could maintain the amount of total polyphenol, total flavonoid and antioxidant capacity, preserving the nutritional and functional values of the product. Same cook value of MW treatment resulted in similar inactivation level of PPO. PME significantly decreased when power density increased at cook value 3. PME was more resistant to MW treatment than PPO in peach puree. Higher cook value better preserved the antioxidants and antioxidant capacities.
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Affiliation(s)
- Linyan Zhou
- Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Chemical and Materials Engineering Department, University of Auckland, 20 Symonds St, Auckland, 1142, New Zealand
| | - Chia Ying Tey
- Chemical and Materials Engineering Department, University of Auckland, 20 Symonds St, Auckland, 1142, New Zealand
| | - Gokhan Bingol
- Chemical and Materials Engineering Department, University of Auckland, 20 Symonds St, Auckland, 1142, New Zealand
| | - Murat O Balaban
- Chemical and Materials Engineering Department, University of Auckland, 20 Symonds St, Auckland, 1142, New Zealand
| | - Shengbao Cai
- Faculty of Agriculture and Food, Kunming University of Science and Technology, Kunming, Yunnan Province, China
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17
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Lima C, Helene AF, Camacho A. Leaf-cutting ants' critical and voluntary thermal limits show complex responses to size, heating rates, hydration level, and humidity. J Comp Physiol B 2021. [PMID: 34837117 DOI: 10.1007/s00360-021-01413-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 08/30/2021] [Accepted: 10/03/2021] [Indexed: 11/25/2022]
Abstract
Thermal variation has complex effects on organisms and they respond to these effects through combined behavioral and physiological mechanisms. However, it is less clear how these traits combine in response to changes in body condition (e.g., size, hydration) and environmental factors that surround the heating process (e.g., relative humidity, start temperatures, heating rates). We tested whether these body conditions and environmental factors influence sequentially measured Voluntary Thermal Maxima (VTmax) and Critical Thermal Maxima, (CTmax) in leaf-cutting ants (Atta sexdens rubropilosa, Forel, 1908). VTmax and CTmax reacted differently to changes in body size and relative humidity, but exhibited similar responses to hydration level, start temperature, and heating rate. Strikingly, the VTmax of average-sized workers was closer to their CTmax than the VTmax of their smaller and bigger sisters, suggesting foragers maintain normal behavior at higher temperatures than sister ants that usually perform tasks within the colony. Previous experiments based on hot plate designs might overestimate ants’ CTmax. VTmax and CTmax may respond concomitantly or not to temperature rises, depending on body condition and environmental factors.
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Ferrero L, Bernardoni V, Santagostini L, Cogliati S, Soldan F, Valentini S, Massabò D, Močnik G, Gregorič A, Rigler M, Prati P, Bigogno A, Losi N, Valli G, Vecchi R, Bolzacchini E. Consistent determination of the heating rate of light-absorbing aerosol using wavelength- and time-dependent Aethalometer multiple-scattering correction. Sci Total Environ 2021; 791:148277. [PMID: 34119780 DOI: 10.1016/j.scitotenv.2021.148277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM2.5) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23-30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HRFF (+24 ± 1%) and higher HRBC (+10 ± 1%) than that of AE31. Conversely, HRBB and HRBrC were -28 ± 1% and -29 ± 1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent Cλ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination. Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - V Bernardoni
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - L Santagostini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cogliati
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; Remote Sensing of Environmental Dynamics Lab., DISAT, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano, Italy
| | - F Soldan
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - S Valentini
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - D Massabò
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - G Močnik
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - P Prati
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - A Bigogno
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - G Valli
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - R Vecchi
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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Shi S, Zhu B, Lu W, Yan S, Fang C, Liu X, Liu D, Liu C. Estimation of radiative forcing and heating rate based on vertical observation of black carbon in Nanjing, China. Sci Total Environ 2021; 756:144135. [PMID: 33288247 DOI: 10.1016/j.scitotenv.2020.144135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/12/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
Owing to a lack of vertical observations, the impacts of black carbon (BC) on radiative forcing (RF) have typically been analyzed using ground observations and assumed profiles. In this study, a UAV platform was used to measure high-resolution in-situ vertical profiles of BC, fine particles (PM2.5), and relevant meteorological parameters in the boundary layer (BL). Further, a series of calculations using actual vertical profiles of BC were conducted to determine its impact on RF and heating rate (HR). The results show that the vertical distributions of BC were strongly affected by atmospheric thermodynamics and transport. Moreover. Three main types of profiles were revealed: Type I, Type II, Type III, which correspond to homogenous profiles (HO), negative gradient profiles (NG), and positive gradient profiles (PG), respectively. Types I and II were related to the diurnal evolution of the BL, and Type III was caused by surrounding emissions from high stacks and regional transport. There were no obvious differences in RF calculated for HO profiles and corresponding surface BC concentrations, unlike for NG and PG profiles. RF values calculated using surface BC concentrations led to an overestimate of 13.2 W m-2 (27.5%, surface) and 18.2 W m-2 (33.4%, atmosphere) compared to those calculated using actual NG profiles, and an underestimate of approximately 15.4 W m-2 (35.0%, surface) and 16.1 W m-2 (29.9%, atmosphere) compared to those calculated using actual PG profiles. In addition, the vertical distributions of BC HR exhibited clear sensitivity to BC profile types. Daytime PG profiles resulted in a positive vertical gradient of HR, which may strengthen temperature inversion at high altitudes. These findings indicate that calculations that use BC surface concentrations and ignore the vertical distribution of BC will lead to substantial uncertainties in the effects of BC on RF and HR.
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Affiliation(s)
- Shuangshuang Shi
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Bin Zhu
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China.
| | - Wen Lu
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Shuqi Yan
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Chenwei Fang
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xiaohui Liu
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Duanyang Liu
- Key Laboratory of Transportation Meteorology, China Meteorological Administration, Jiangsu Institute of Meteorological Sciences, Nanjing Joint Institute for Atmospheric Sciences, Nanjing 210008, China
| | - Chao Liu
- Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environment Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology, Nanjing 210044, China
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Rupakheti D, Rupakheti M, Abdullaev SF, Yin X, Kang S. Columnar aerosol properties and radiative effects over Dushanbe, Tajikistan in Central Asia. Environ Pollut 2020; 265:114872. [PMID: 32497948 DOI: 10.1016/j.envpol.2020.114872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/14/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
This paper presents the results of the study on columnar aerosol optical and physical properties and radiative effects directly observed over Dushanbe, the capital city of Tajikistan, a NASA AERONET site (equipped with a CIMEL sunphotometer) in Central Asia. The average aerosol optical depth (AOD) and Ångström exponent (AE) during the observation period from July 2010 to April 2018 were found to be 0.28 ± 0.20 and 0.82 ± 0.40, respectively. The highest seasonal AOD (0.32 ± 0.24), accompanied by the lowest average AE (0.61 ± 0.25) and fine-mode fraction in AOD (0.39), was observed during summer due to the influence of coarse particles like dust from arid regions. Fine particles were found in significant amounts during winter. The 'mixed aerosol' was identified as the dominant aerosol type with presence of 'dust aerosol' during summer and autumn seasons. Aerosol properties like volume size distribution, single scattering albedo, asymmetry parameter and refractive index suggested the influence of coarse particles (during summer and autumn). Most of the air masses reaching this site transported local and regional emissions, including from beyond Central Asia, explaining the presence of various aerosol types in Dushanbe's atmosphere. The seasonal aerosol radiative forcing efficiency (ARFE) in the atmosphere was found high (>100 Wm-2) and consistent throughout the year. Consequently, this resulted in similar seasonally coherent high atmospheric solar heating rate (HR) of 1.5 K day-1 during summer-autumn-winter, and ca. 0.9 K day-1 during spring season. High ARFE and HR values indicate that atmospheric aerosols could exert significant implications to regional air quality, climate and cryosphere over the central Asian region and downwind Tianshan and Himalaya-Tibetan Plateau mountain regions with sensitive ecosystems.
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Affiliation(s)
- Dipesh Rupakheti
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | | | - Sabur F Abdullaev
- Physical Technical Institute of the Academy of Sciences of Tajikistan, Dushanbe, Tajikistan
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100101, China.
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21
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Hu K, Zhao D, Liu D, Ding S, Tian P, Yu C, Zhou W, Huang M, Ding D. Estimating radiative impacts of black carbon associated with mixing state in the lower atmosphere over the northern North China Plain. Chemosphere 2020; 252:126455. [PMID: 32197175 DOI: 10.1016/j.chemosphere.2020.126455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 02/29/2020] [Accepted: 03/08/2020] [Indexed: 06/10/2023]
Abstract
Black carbon (BC) exerts important radiative effects over regions with intensive emissions. This study presents in-situ aircraft measurements of BC vertical profiles including mass loading, size distribution and mixing state, spanning a range of pollution levels in both warm and cold seasons over Beijing. The development of planetary boundary layer (PBL) influenced the properties of pollutants at low levels, and regional transport from the southwest elevated the pollution at higher altitudes. Thicker coatings of BC were associated with higher pollution in the PBL, where interactions between BC and other substances intensively took place. Considering the mixing state of BC, the absorption efficiency could be potentially increased by up to 86% and 60% in the PBL and lower free troposphere, respectively. Including a column-integrated absorption enhancement, the in-situ constrained absorption aerosol optical depth at wavelength 870 nm (AAOD870) improved the agreement with AERONET by 28%, but the in-situ measurement remained 19% lower. A radiative transfer model finds a BC heating rate of 0.1-0.3 K/d and 0.5-3.1 K/d for less and more polluted environments respectively, and the BC coating effect could positively introduce a +0.1-4.2 Wm-2 radiative forcing. The presence of aerosol layer enhanced the positive vertical gradient of heating rate by redistributing the actinic flux. In particular, this gradient was further enhanced by introducing thickly-coated BC at higher level during the regional transport events, which may promote the temperature inversion and further depress the PBL development on polluted days.
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Affiliation(s)
- Kang Hu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Delong Zhao
- Beijing Weather Modification Office, Beijing, China
| | - Dantong Liu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Shuo Ding
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ping Tian
- Beijing Weather Modification Office, Beijing, China
| | - Chenjie Yu
- Centre for Atmospheric Sciences, School of Earth and Environmental Sciences, University of Manchester, Manchester, M13 9PL, UK
| | - Wei Zhou
- Beijing Weather Modification Office, Beijing, China
| | - Mengyu Huang
- Beijing Weather Modification Office, Beijing, China
| | - Deping Ding
- Beijing Weather Modification Office, Beijing, China
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Akça S. Determination of thermoluminescence properties of ZnB 2O 4:Tm 3+,Li + for dosimetric purposes. Appl Radiat Isot 2020; 157:109041. [PMID: 32063334 DOI: 10.1016/j.apradiso.2020.109041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/08/2020] [Accepted: 01/08/2020] [Indexed: 11/19/2022]
Abstract
This study aims to investigate the comparison of the thermoluminescence (TL) emission of Li+ and Tm3+ co-doped and un-doped zinc borate (ZnB2O4) phosphors prepared by wet chemical synthesis method. The crystal structure of the samples has been determined by means of X-ray powder diffraction and matched with the standard pattern of ZnB2O4 (PDF Card No. 039-1126). TL glow curves of 5 Gy beta irradiated Li+ (at different concentrations of 0.2, 0.5, 0.8 and 1.0%) and Tm3+ (1.0%) co-doped ZnB2O4 have been recorded using various band pass filters to determine both the optimum concentration and the suitable filter. The TL green emission (565 nm) of Li+ (1.0%), Tm3+ (1.0%) co-doped ZnB2O4 phosphor displays a complex structure where one can distinguish, at least, three groups of components peaked at 69, 166 and 291 °C where the more suitable dosimetric maxima appears at higher temperature. It could be observed how the 166 and 291 °C TL glow maxima of this material exhibits (i) good linearity in the range of 0.11-15 Gy, (ii) a minimum detectable dose value of 1.11 mGy, (iii) does not modify significantly the TL emission in shape and intensity after reusability (10 cycles) and (iv) a negligible fading effect for 5 Gy irradiated aliquots stored in darkness and room temperature up to 169 h. Additionally, it could be found that (v) kinetic parameters estimated by using variable heating rate method of Hoogenstraaten and initial rise method give similar results.
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Affiliation(s)
- Sibel Akça
- Cukurova University, Arts-Sciences Faculty, Physics Department, 01330, Adana, Turkey.
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Adhikari S, Gascó G, Méndez A, Surapaneni A, Jegatheesan V, Shah K, Paz-Ferreiro J. Influence of pyrolysis parameters on phosphorus fractions of biosolids derived biochar. Sci Total Environ 2019; 695:133846. [PMID: 31416032 DOI: 10.1016/j.scitotenv.2019.133846] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 07/22/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Transforming biosolids into biochar, through pyrolysis, could result in more sustainable waste management. Influence of pyrolysis conditions (temperature, heating rate and residence time) on physico-chemical properties of biosolids (collected at Mount Martha Water Recycling Plant, Melbourne), phosphorus fractions and phosphorus forms was investigated. Twelve different biochar samples were produced at 400, 500 and 600 °C, at two heating rates (5 and 20 °C/min) and at two residence times (30 and 120 min). Biochar yield, pH, electrical conductivity (EC), elements (C, H and N) and BET surface area were analysed. Sequential extraction of P in biosolids and resultant biochars was done using Hedley method. Characterization was completed with SEM images and results from 31P liquid state NMR. Increased temperatures would not only increase the alkalinity, decrease EC and increase the adsorption capacity by increasing the surface area but also convert the readily available P to a less available pool. Therefore, this nutrient might be released to soil slowly over a longer period of time. The results showed that temperature, along with residence time and heating rate, had a significant effect on the characteristics observed. Therefore, all these factors need to be carefully considered when preparing biochar for use as a soil amendment.
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Affiliation(s)
- S Adhikari
- School of Engineering, RMIT University, GPO Box 2476, 3001 VIC, Melbourne, Australia
| | - G Gascó
- Department of Agricultural Production, Technical University of Madrid, Ciudad Universitaria, 28040 Madrid, Spain
| | - A Méndez
- Department of Geological and Mining Engineering, Technical University of Madrid, 28040 Madrid, Spain
| | - A Surapaneni
- South East Water Corporation, Waters Edge, 101 Wells Street, Frankston 3199, Victoria, Australia
| | - V Jegatheesan
- School of Engineering, RMIT University, GPO Box 2476, 3001 VIC, Melbourne, Australia
| | - K Shah
- School of Engineering, RMIT University, GPO Box 2476, 3001 VIC, Melbourne, Australia
| | - J Paz-Ferreiro
- School of Engineering, RMIT University, GPO Box 2476, 3001 VIC, Melbourne, Australia.
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Öztürk C, Çelik E. Influence of heating rate on the flexural strength of monolithic zirconia. J Adv Prosthodont 2019; 11:202-208. [PMID: 31497267 PMCID: PMC6718841 DOI: 10.4047/jap.2019.11.4.202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/17/2019] [Accepted: 08/02/2019] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Fabrication of zirconia restorations with ideal mechanical properties in a short period is a great challenge for clinicians. The purpose of the study was to investigate the effect of heating rate on the mechanical and microstructural properties of monolithic zirconia. MATERIALS AND METHODS Forty monolithic zirconia specimens were prepared from presintered monolithic zirconia blanks. All specimens were then assigned to 4 groups according to heating rate as Control, Group 15℃, Group 20℃, and Group 40℃. All groups were sintered according to heating rates with the sintering temperature of 1500℃, a holding time of 90 minutes and natural cooling. The phase composition was examined by XRD analysis, three-point bending test was conducted to examine the flexural strength, and Weibull analysis was conducted to determine weibull modulus and characteristic strength. Average grain sizes were determined by SEM analysis. One-way ANOVA test was performed at a significance level of 0.05. RESULTS Only tetragonal phase characteristic peaks were determined on the surface of analyzed specimens. Differences among the average grain sizes of the groups were not statistically significant. The results of the three-point bending test revealed no significant differences among the flexural strength of the groups (P>.05). Weibull modulus of groups was ranging from 3.50 to 4.74. The highest and the lowest characteristic strength values were obtained in Group 20℃ and Control Group, respectively. CONCLUSION Heating rate has no significant effect on the flexural strength of monolithic zirconia. Monolithic zirconia restorations can be produced in shorter sintering periods without affecting the flexural strength by modifying the heating rate.
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Affiliation(s)
- Caner Öztürk
- Department of Prosthodontics, Faculty of Dentistry, Hatay Mustafa Kemal University, Hatay, Turkey
| | - Ersan Çelik
- Department of Prosthodontics, Faculty of Dentistry, Ordu University, Ordu, Turkey
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Londoño-Restrepo SM, Millán-Malo BM, Del Real-López A, Rodriguez-García ME. In situ study of hydroxyapatite from cattle during a controlled calcination process using HT-XRD. Mater Sci Eng C Mater Biol Appl 2019; 105:110020. [PMID: 31546350 DOI: 10.1016/j.msec.2019.110020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 10/26/2022]
Abstract
In situ High-Temperature X-ray diffraction (HT-XRD) from 400 to 900 °C was carried out to obtain patterns of bio hydroxyapatite every 20 °C during calcination processes at heating rates of 3, 6, and 9 °C/min to determine changes in its structural parameters as well as in its thermal expansion coefficient (TEC) for a and c lattice parameters. Additionally, High-Resolution Transmission Electron microscopy (HR-TEM) demonstrates that this HAp has an ordered nano like plate crystalline structure. The raw sample exhibits broad X-ray peaks originated by its nano size, and after calcination at about 700 °C, these become narrowed due to crystal growth. The calculation of the TEC as a function of the temperature for this hydroxyapatite shows a nonlinear increment for the a and c lattice parameters. Lattice thermal expansion occurs as water and organic matter are lost as the coalescence of HAp crystals take place; furthermore, as the heating rate increases, so does the lattice volume. Thermal analyses confirm that crystal growth is a process that starts after the bone sample has lost all its organic material and then bio-hydroxyapatite size changes from nano to micro-scale. A simulation using the PDF-4 software confirmed the nanometric size of the hydroxyapatite.
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Affiliation(s)
- Sandra M Londoño-Restrepo
- Posgrado en Ciencia e Ingeniería de Materiales, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, 76230 Querétaro, Qro., Mexico; Escuela Nacional de Estudios Superiores (ENES), Universidad Nacional Autónoma de México, Campus Juriquilla, 76230 Querétaro, Qro., Mexico.
| | - Beatriz M Millán-Malo
- Departamento de Nanotecnología, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, 76230 Querétaro, Qro., Mexico
| | - Alicia Del Real-López
- Departamento de Ingeniería Molecular de Materiales, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, 76230 Querétaro, Qro., Mexico
| | - Mario E Rodriguez-García
- Departamento de Nanotecnología, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, 76230 Querétaro, Qro., Mexico
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Yüksel M, Dogan T, Portakal ZG, Topaksu M. Synthesis and luminescence characterization of microcrystalline Nd-doped calcium sulfate. Appl Radiat Isot 2019; 148:197-203. [PMID: 30981124 DOI: 10.1016/j.apradiso.2019.04.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/15/2019] [Accepted: 04/03/2019] [Indexed: 11/16/2022]
Abstract
In the present study, the precipitation method was used to synthesize microcrystalline Nd-doped CaSO4 phosphor. Structural and morphological analysis of the phosphor samples were performed by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. In addition, luminescent properties of the samples were characterized by thermoluminescence (TL) and optically stimulated luminescence (OSL) methods. The results of XRD analysis and SEM images showed that the prepared CaSO4:Nd powder samples have an orthorhombic crystal structure and almost spherical in size with an average between 3 and 17 μm. In the light of the luminescence analysis, the optimum preheat temperature required to evacuate the low temperature electron traps was determined as 170 °C. It was also presented that CaSO4:Nd samples have the potential to be used as a dosimetric material with a linear dose sensitivity between 1 and 20 Gy (as TL dosimeter), and 1 and 10 Gy (as an OSL dosimeter) when they are exposed to beta irradiation. In addition, the full width at the half maximum (FWHM) values of the main TL peaks presented no independence of HR.
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Affiliation(s)
- Mehmet Yüksel
- Çukurova University, Arts-Sciences Faculty, Physics Department, 01330, Adana, Turkey.
| | - Tamer Dogan
- Çukurova University, Vocational School of Imamoglu, Department of Computer Technologies, 01700, Adana, Turkey
| | | | - Mustafa Topaksu
- Çukurova University, Arts-Sciences Faculty, Physics Department, 01330, Adana, Turkey
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Ko JH, Wang J, Xu Q. Impact of pyrolysis conditions on polycyclic aromatic hydrocarbons (PAHs) formation in particulate matter (PM) during sewage sludge pyrolysis. Chemosphere 2018; 208:108-116. [PMID: 29864701 DOI: 10.1016/j.chemosphere.2018.05.120] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/10/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) not only present a risk to human health when released into the air, but also can be precursors to form particulate matter (PM) during sewage sludge pyrolysis. In this study, 16 EPA PAHs in PM (ΣPAHPM) during sewage sludge pyrolysis were investigated with increasing temperature (200oC-1000 °C) and holding time under different operation conditions [inert gas flow rate (IGFR) (200-800 mL/min) and heating rate (5-20 °C/min)]. ΣPAHPM varied with temperature, IGFR, and heating rate, and ranged from 597 (±41) μg/g to 3240 (±868) μg/g. ΣPAHPM decreased with increasing IGFR but increased with rapid heating rate. Among PAHs species in PM, naphthalene (Nap) was commonly detected at low temperature ranges in all tested conditions. Chrysene (CHR), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd] pyrene (IND), and benzo[g,h,i]perylene (BghiP) in PM became abundant at high temperature with a low IGFR. At high temperature ranges with high volatile conditions (rapid heating rate and low IGFR), PAH formation and growth reactions were considerable, resulting in the formation of heavy PAHs in PM.
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Affiliation(s)
- Jae Hac Ko
- Key Laboratory for Eco-Efficient Polysilicate Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055 China
| | - Jingchen Wang
- Key Laboratory for Eco-Efficient Polysilicate Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055 China
| | - Qiyong Xu
- Key Laboratory for Eco-Efficient Polysilicate Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055 China.
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28
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Efika CE, Onwudili JA, Williams PT. Influence of heating rates on the products of high-temperature pyrolysis of waste wood pellets and biomass model compounds. Waste Manag 2018; 76:497-506. [PMID: 29559298 DOI: 10.1016/j.wasman.2018.03.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/19/2018] [Accepted: 03/09/2018] [Indexed: 06/08/2023]
Abstract
The effect of heating rates ranging from 5 °C min-1 to 350 °C min-1 on the yields of pyrolysis products of wood and its main pseudo-components (cellulose, hemicellulose and lignin) have been investigated at a temperature of 800 °C in a horizontal fixed bed reactor. Results showed a successive dramatic increase and decrease in gas and liquid yields, respectively, while the yields of solid products showed a gradual decrease as heating rates increased. Increased gas formation and an increasingly aromatic oil/tar support the theory of rapid devolatilization of degradation products with increasing heating rate, leading to extensive cracking of primary pyrolysis vapours. Solid products with coal-like calorific value and large surface areas were obtained. CO became the dominant gas both on a mass and volume basis, at the heating rate of 350 °C min-1 for all samples except xylan, which also produced a significant yield of CO2 (20.3 wt% and 25.4 vol%) compared to the other samples. Cellulose produced a gas product with highest calorific value of 35 MJ kg-1 at the highest heating rate. Results also indicate that the three main pseudo-components of biomass each exert a different influence on the products of high temperature pyrolysis of woody biomass.
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Affiliation(s)
- Chidi E Efika
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9 JT, UK
| | - Jude A Onwudili
- School of Engineering and Applied Sciences, Aston University, Birmingham B4 7ET, UK.
| | - Paul T Williams
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9 JT, UK
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29
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Eren Gültekin E. The effect of heating rate and sintering temperature on the elastic modulus of porcelain tiles. Ultrasonics 2018; 83:120-125. [PMID: 28610712 DOI: 10.1016/j.ultras.2017.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/01/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
The scope of the present study is to investigate the change of elastic modulus with the physical and mechanical properties of porcelain tiles. In the study, porcelain tiles were sintered at different temperatures and at different heating rates to obtain minimum water absorption (%). After this, the time of flight of longitudinal and shear ultrasonic waves was measured through the tile. The time of flight of ultrasonic waves was measured using contact ultrasonic transducers operating on a pulse-echo mode. Using the time of flight of the ultrasonic waves and the thickness of the tiles, the velocity of the waves was determined. Using the ultrasonic velocities and bulk density, the elastic modulus of the tiles was determined. Helium pycnometry, a bend test, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were also carried out. The results show that the elastic modulus decreased with an increase of total porosity, but increased with bulk density and firing shrinkage. There is a polynomial relationship between elastic modulus and strength.
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Affiliation(s)
- Elif Eren Gültekin
- Nevşehir Hacı Bektaş Veli University, Fine Arts Faculty, Department of Ceramic and Glass, Prof. Dr. Rıza Ayhan Street, 50800 Hacibektas-Nevsehir, Turkey.
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Sharma D, Srivastava AK, Ram K, Singh A, Singh D. Temporal variability in aerosol characteristics and its radiative properties over Patiala, northwestern part of India: Impact of agricultural biomass burning emissions. Environ Pollut 2017; 231:1030-1041. [PMID: 28915541 DOI: 10.1016/j.envpol.2017.08.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 08/11/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
A comprehensive measurements of aerosol optical depth (AOD), particulate matter (PM) and black carbon (BC) mass concentrations have been carried out over Patiala, a semi-urban site in northwest India during October 2008 to September 2010. The measured aerosol data was incorporated in an aerosol optical model to estimate various aerosol optical parameters, which were subsequently used for radiative forcing estimation. The measured AOD at 500 nm (AOD500) shows a significant seasonal variability, with maximum value of 0.81 during post-monsoon (PoM) and minimum of 0.56 during winter season. The Ångström exponent (α) has higher values (i.e. more fine-mode fraction) during the PoM/winter periods, and lower (i.e. more coarse-mode fraction) during pre-monsoon (PrM). In contrast, turbidity coefficient (β) exhibits an opposite trend to α during the study period. BC mass concentration varies from 2.8 to 13.9 μg m-3 (mean: 6.5 ± 3.2 μg m-3) during the entire study period, with higher concentrations during PoM/winter and lower during PrM/monsoon seasons. The average single scattering albedo (SSA at 500 nm) values are 0.70, 0.72, 0.82 and 0.75 during PoM, winter, PrM and monsoon seasons, respectively. However, inter-seasonal and inter-annual variability in measured aerosol parameters are statistically insignificant at Patiala. These results suggest strong changes in emission sources, aerosol composition, meteorological parameters as well as transport of aerosols over the station. Higher values of AOD, α and BC, along with lower SSA during PoM season are attributed to agriculture biomass burning emissions over and around the station. The estimated aerosol radiative forcing within the atmosphere is positive (i.e. warming) during all the seasons with higher values (∼60 Wm-2) during PoM-08/PoM-09 and lower (∼40 Wm-2) during winter-09/PrM-10. The present study highlights the role of BC aerosols from agricultural biomass burning emissions during post-monsoon season for atmospheric warming at Patiala.
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Affiliation(s)
- D Sharma
- Department of Physics, Punjabi University, Patiala, India; Department of Physics, Arya College, Ludhiana, India
| | - A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India.
| | - K Ram
- Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi, India
| | - A Singh
- Department of Physics, Punjabi University, Patiala, India
| | - D Singh
- Department of Physics, Punjabi University, Patiala, India
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Patel PN, Dumka UC, Babu KN, Mathur AK. Aerosol characterization and radiative properties over Kavaratti, a remote island in southern Arabian Sea from the period of observations. Sci Total Environ 2017; 599-600:165-180. [PMID: 28475910 DOI: 10.1016/j.scitotenv.2017.04.168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/18/2017] [Accepted: 04/22/2017] [Indexed: 06/07/2023]
Abstract
Long-term measurements of spectral aerosol optical depth (AOD) using sun/sky radiometer for a period of five years (2009-2014) from the remote island location at Kavaratti (KVT; 10.56°N, 72.64°E) in the southern Arabian sea have been analysed. Climatologically, AODs decrease from October to reach maximum of ~0.6 (at 500nm) in March, followed by a sudden fall towards May. Significant modulations of intra-seasonal timescales over this general pattern are noticed due to the changes in the relative strength of distinctively different sources. The corresponding changes in aerosol inversion parameters reveal the presence of coarse-mode aerosols during spring and fine-mode absorbing aerosols in autumn and winter months. An overall dominance of a mixed type of aerosols (~41%) with maximum in winter (~53%) was found via the AOD500 vs. Ångström exponent (α440-870) relationship, while biomass-burning aerosols or thick urban/industrial plumes contribute to ~19%. Spectral dependence of Ångström exponent and aerosol absorbing properties were used to identify the aerosol types and its modification processes. Based on air mass back trajectory analysis, we revealed that the advection of aerosols from Indian subcontinent and western regions plays a major role in modifying the optical properties of aerosols over the observational site. The shortwave aerosol direct radiative forcing estimated via SBDART model ranges from -11.00Wm-2 to -7.38Wm-2, -21.51Wm-2 to -14.33Wm-2 and 3.17Wm-2 and 10.0Wm-2 at top of atmosphere, surface and within the atmosphere, respectively. This atmospheric forcing translates into heating rate of 0.62-1.04Kday-1. Furthermore, the vertical profiles of aerosols and heating rate exhibit significant increase in lower (during winter and autumn) and mid troposphere (during spring). This may cause serious climate implications over Kavaratti with further consequences on cloud microphysics and monsoon rainfall.
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Affiliation(s)
- Piyushkumar N Patel
- Calibration & Validation Division, Space Applications Centre, ISRO, Ahmedabad 380 015, India.
| | - U C Dumka
- Aryabhatta Research Institute of Observational Sciences, Nainital 263 001, India.
| | - K N Babu
- Calibration & Validation Division, Space Applications Centre, ISRO, Ahmedabad 380 015, India
| | - A K Mathur
- Calibration & Validation Division, Space Applications Centre, ISRO, Ahmedabad 380 015, India
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Cao Q, Yuan G, Yin L, Chen D, He P, Wang H. Morphological characteristics of polyvinyl chloride (PVC) dechlorination during pyrolysis process: Influence of PVC content and heating rate. Waste Manag 2016; 58:241-249. [PMID: 27596943 DOI: 10.1016/j.wasman.2016.08.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 08/12/2016] [Accepted: 08/26/2016] [Indexed: 06/06/2023]
Abstract
In this research morphological techniques were used to characterize dechlorination process of PVC when it is in the mixed waste plastics and the two important factors influencing this process, namely, the proportion of PVC in the mixed plastics and heating rate adopted in the pyrolysis process were investigated. During the pyrolysis process for the mixed plastics containing PVC, the morphologic characteristics describing PVC dechlorination behaviors were obtained with help of a high-speed infrared camera and image processing tools. At the same time emission of hydrogen chloride (HCl) was detected to find out the start and termination of HCl release. The PVC contents in the mixed plastics varied from 0% to 12% in mass and the heating rate for PVC was changed from 10 to 60°C/min. The morphologic parameters including "bubble ratio" (BR) and "pixel area" (PA) were found to have obvious features matching with PVC dechlorination process therefore can be used to characterize dechlorination of PVC alone and in the mixed plastics. It has been also found that shape of HCl emission curve is independent of PVC proportions in the mixed plastics, but shifts to right side with elevated heating rate; and all of which can be quantitatively reflected in morphologic parameters vs. temperature curves.
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Affiliation(s)
- Qiongmin Cao
- Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092, China
| | - Guoan Yuan
- Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092, China
| | - Lijie Yin
- Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092, China.
| | - Dezhen Chen
- Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092, China
| | - Pinjing He
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 200092 Shanghai, China
| | - Hai Wang
- Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092, China
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Deng T, Deng X, Li F, Wang S, Wang G. Study on aerosol optical properties and radiative effect in cloudy weather in the Guangzhou region. Sci Total Environ 2016; 568:147-154. [PMID: 27295588 DOI: 10.1016/j.scitotenv.2016.05.156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
Currently, Guangzhou region was facing the problem of severe air pollution. Large amount of aerosols in the polluted air dramatically attenuated solar radiation. This study investigated the vertical optical properties of aerosols and inverted the height of boundary layer in the Guangzhou region using the lidar. Simultaneously, evaluated the impact of different types of clouds on aerosol radiation effects using the SBDART. The results showed that the height of the boundary layer and the surface visibility changed consistently, the average height of the boundary layer on the hazy days was only 61% of that on clear days. At the height of 2km or lower, the aerosol extinction coefficient profile distribution decreased linearly along with height on clear days, but the haze days saw an exponential decrease. When there was haze, the changing of heating rate of atmosphere caused by the aerosol decreased from 3.72K/d to 0.9K/d below the height of 2km, and the attenuation of net radiation flux at the ground surface was 97.7W/m(2), and the attenuation amplitude was 11.4%; when there were high clouds, the attenuation was 125.2W/m(2) and the attenuation amplitude was 14.6%; where there were medium cloud, the attenuation was 286.4W/m(2) and the attenuation amplitude was 33.4%. Aerosol affected mainly shortwave radiation, and affected long wave radiation very slightly.
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Affiliation(s)
- Tao Deng
- Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080, China.
| | - XueJiao Deng
- Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080, China
| | - Fei Li
- Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510080, China
| | - ShiQiang Wang
- Zhuhai Meteorological Administration, Zhuhai 519000, China
| | - Gang Wang
- Haizhu Meteorological Administration, Guangzhou, 510000, China
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Chen D, Li Y, Cen K, Luo M, Li H, Lu B. Pyrolysis polygeneration of poplar wood: Effect of heating rate and pyrolysis temperature. Bioresour Technol 2016; 218:780-788. [PMID: 27423545 DOI: 10.1016/j.biortech.2016.07.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 07/09/2016] [Accepted: 07/11/2016] [Indexed: 06/06/2023]
Abstract
The pyrolysis of poplar wood were comprehensively investigated at different pyrolysis temperatures (400, 450, 500, 550, and 600°C) and at different heating rates (10, 30, and 50°C/min). The results showed that BET surface area of biochar, the HHV of non-condensable gas and bio-oil reached the maximum values of 411.06m(2)/g, 14.56MJ/m(3), and 14.39MJ/kg, under the condition of 600°C and 30°C/min, 600°C and 50°C/min, and 550°C and 50°C/min, respectively. It was conducive to obtain high mass and energy yield of bio-oil at 500°C and higher heating rate, while lower pyrolysis temperature and heating rate contributed towards obtaining both higher mass yield and energy yield of biochar. However, higher pyrolysis temperature and heating rate contributed to obtain both higher mass yield and energy yield of the non-condensable gas. In general, compared to the heating rate, the pyrolysis temperature had more effect on the product properties.
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Affiliation(s)
- Dengyu Chen
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Yanjun Li
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
| | - Kehui Cen
- Nanfang College, Nanjing Forestry University, Nanjing 210037, China
| | - Min Luo
- Nanfang College, Nanjing Forestry University, Nanjing 210037, China
| | - Hongyan Li
- Nanfang College, Nanjing Forestry University, Nanjing 210037, China
| | - Bin Lu
- Nanfang College, Nanjing Forestry University, Nanjing 210037, China
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Yavari S, Malakahmad A, Sapari NB. Effects of production conditions on yield and physicochemical properties of biochars produced from rice husk and oil palm empty fruit bunches. Environ Sci Pollut Res Int 2016; 23:17928-17940. [PMID: 27255313 DOI: 10.1007/s11356-016-6943-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/20/2016] [Indexed: 06/05/2023]
Abstract
Biochar is the bio-solid material produced by pyrolysis. The biochar properties are controlled by feedstock and pyrolysis variables. In this study, the impacts of these production variables on biochar yield and physicochemical properties including pH, cation exchange capacity (CEC), total organic carbon (TOC) content, surface area, and pore volume and size were investigated. Rice husk (RH) and oil palm empty fruit bunches (EFB) were used as biomass. The biochars were produced at temperature range of 300 to 700 °C, heating rate of 3 to 10 °C/min and retention time of 1 to 3 h. The pyrolysis conditions were optimized using response surface methodology (RSM) technique to maximize the values of the responses. Analysis of variance (ANOVA) of the results demonstrated that the data fitted well to the linear and quadratic equations. Temperature was found to be the most effective parameter on the responses followed by retention time and heating rate, sequentially. CEC, TOC, surface area, and pore characteristics were evaluated as biochar properties determining their sorption potential. The optimum conditions for the maximum values of the properties were temperatures of 700 and 493.44 °C and time of 3 and 1 h for RH and EFB biochars, respectively. Heating rate at 3 °C/min was found to be the best rate for both biochars. The structure of EFB biomass was more sensitive to heating than rice husk. The biomass type and the production variables were demonstrated as the direct effective factors on biochar yield and physicochemical properties.
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Affiliation(s)
- Saba Yavari
- Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Bandar Seri, Iskandar, Malaysia.
| | - Amirhossein Malakahmad
- Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Bandar Seri, Iskandar, Malaysia
| | - Nasiman B Sapari
- Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Bandar Seri, Iskandar, Malaysia
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Matthews G, Goulet CT, Delhey K, Chapple DG. The effect of skin reflectance on thermal traits in a small heliothermic ectotherm. J Therm Biol 2016; 60:109-24. [PMID: 27503723 DOI: 10.1016/j.jtherbio.2016.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/16/2016] [Accepted: 06/20/2016] [Indexed: 11/19/2022]
Abstract
Variation in colour patterning is prevalent among and within species. A number of theories have been proposed in explaining its evolution. Because solar radiation interacts with the pigmentation of the integument causing light to either be reflected or absorbed into the body, thermoregulation has been considered to be a primary selective agent, particularly among ectotherms. Accordingly, the colour-mediated thermoregulatory hypothesis states that darker individuals will heat faster and reach higher thermal equilibria while paler individuals will have the opposite traits. It was further predicted that dark colouration would promote slower cooling rates and higher thermal performance temperatures. To test these hypotheses we quantified the reflectance, selected body temperatures, performance optima, as well as heating and cooling rates of an ectothermic vertebrate, Lampropholis delicata. Our results indicated that colour had no influence on thermal physiology, as all thermal traits were uncorrelated with reflectance. We suggest that crypsis may instead be the stronger selective agent as it may have a more direct impact on fitness. Our study has improved our knowledge of the functional differences among individuals with different colour patterns, and the evolutionary significance of morphological variation within species.
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Affiliation(s)
- Genevieve Matthews
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Celine T Goulet
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Kaspar Delhey
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - David G Chapple
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
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Mundike J, Collard FX, Görgens JF. Torrefaction of invasive alien plants: Influence of heating rate and other conversion parameters on mass yield and higher heating value. Bioresour Technol 2016; 209:90-9. [PMID: 26954309 DOI: 10.1016/j.biortech.2016.02.082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 05/15/2023]
Abstract
With the aim of controlling their proliferation, two invasive alien plants, Lantana camara (LC) and Mimosa pigra (MP), both widespread in Africa, were considered for torrefaction for renewable energy applications. Using thermogravimetric analysis, the influence of heating rate (HR: 2.18-19.82°Cmin(-1)) together with variable temperature and hold time on char yield and HHV (in a bomb calorimeter) were determined. Statistically significant effects of HR on HHV with optima at 10.5°Cmin(-1) for LC and 20°Cmin(-1) for MP were obtained. Increases of HHV up to 0.8MJkg(-1) or energy yield greater than 10%, together with a 3-fold reduction in torrefaction conversion time could be achieved by optimisation of HR. Analysis of the torrefaction volatiles by TG-MS showed that not only hemicelluloses, but also lignin conversion, could influence the optimum HR value.
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Affiliation(s)
- Jhonnah Mundike
- Department of Process Engineering, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - François-Xavier Collard
- Department of Process Engineering, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa.
| | - Johann F Görgens
- Department of Process Engineering, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
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Fan X, Liu Z, Norbeck JM, Park CS. A simple kinetic analysis of syngas during steam hydrogasification of biomass using a novel inverted batch reactor with instant high pressure feeding. Bioresour Technol 2016; 200:731-737. [PMID: 26562689 DOI: 10.1016/j.biortech.2015.10.094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 06/05/2023]
Abstract
A newly designed inverted batch reactor equipped with a pressure-driven feeding system was built for investigating the kinetics of syngas during the steam hydrogasification (SHR) of biomass. The system could instantly load the feedstock into the reactor at high temperature and pressure, which simulated the way to transport the feedstock into a hot and pressurized gasifier. Experiments were conducted from 600°C to 700°C. The inverted reactor showed very high heating rate by enhancing the carbon conversion and syngas production. The kinetic study showed that the rates of CH4, CO and CO2 formation during SHR were increased when the gasification temperature went up. SHR had comparatively lower activation energy for CH4 production. The activation energies of CH4, CO and CO2 during SHR were 42.8, 51.8 and 14kJ/mol, respectively.
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Affiliation(s)
- Xin Fan
- Bourns College of Engineering-Center for Environmental Research and Technology (CE-CERT), Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0425, United States
| | - Zhongzhe Liu
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI 53233, United States.
| | - Joseph M Norbeck
- Bourns College of Engineering-Center for Environmental Research and Technology (CE-CERT), Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0425, United States
| | - Chan S Park
- Bourns College of Engineering-Center for Environmental Research and Technology (CE-CERT), Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521-0425, United States
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Yu J, Sun L, Wang B, Qiao Y, Xiang J, Hu S, Yao H. Study on the behavior of heavy metals during thermal treatment of municipal solid waste (MSW) components. Environ Sci Pollut Res Int 2016; 23:253-65. [PMID: 26538255 DOI: 10.1007/s11356-015-5644-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 10/19/2015] [Indexed: 05/19/2023]
Abstract
Laboratory experiments were conducted to investigate the volatilization behavior of heavy metals during pyrolysis and combustion of municipal solid waste (MSW) components at different heating rates and temperatures. The waste fractions comprised waste paper (Paper), disposable chopstick (DC), garbage bag (GB), PVC plastic (PVC), and waste tire (Tire). Generally, the release trend of heavy metals from all MSW fractions in rapid-heating combustion was superior to that in low-heating combustion. Due to the different characteristics of MSW fractions, the behavior of heavy metals varied. Cd exhibited higher volatility than the rest of heavy metals. For Paper, DC, and PVC, the vaporization of Cd can reach as high as 75% at 500 °C in the rapid-heating combustion due to violent combustion, whereas a gradual increase was observed for Tire and GB. Zn and Pb showed a moderate volatilization in rapid-heating combustion, but their volatilities were depressed in slow-heating combustion. During thermal treatment, the additives such as kaolin and calcium can react or adsorb Pb and Zn forming stable metal compounds, thus decreasing their volatilities. The formation of stable compounds can be strengthened in slow-heating combustion. The volatility of Cu was comparatively low in both high and slow-heating combustion partially due to the existence of Al, Si, or Fe in residuals. Generally, in the reducing atmosphere, the volatility of Cd, Pb, and Zn was accelerated for Paper, DC, GB, and Tire due to the formation of elemental metal vapor. TG analysis also showed the reduction of metal oxides by chars forming elemental metal vapor. Cu2S was the dominant Cu species in reducing atmosphere below 900 °C, which was responsible for the low volatility of Cu. The addition of PVC in wastes may enhance the release of heavy metals, while GB and Tire may play an opposite effect. In controlling heavy metal emission, aluminosilicate- and calcium-based sorbents can be co-treated with fuels. Moreover, pyrolysis can be a better choice for treatment of solid waster in terms of controlling heavy metals. PVC and Tire should be separated and treated individually due to high possibility of heavy metal emission. This information may then serve as a guideline for the design of the subsequent gas cleaning plant, necessary to reduce the final emissions to the atmosphere to an acceptable level.
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Affiliation(s)
- Jie Yu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China
| | - Lushi Sun
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China.
| | - Ben Wang
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China.
| | - Yu Qiao
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China
| | - Jun Xiang
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China
| | - Song Hu
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China
| | - Hong Yao
- State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, 430074, Wuhan, Hubei, China
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Chen D, Zhou J, Zhang Q. Effects of heating rate on slow pyrolysis behavior, kinetic parameters and products properties of moso bamboo. Bioresour Technol 2014; 169:313-319. [PMID: 25063973 DOI: 10.1016/j.biortech.2014.07.009] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/30/2014] [Accepted: 07/01/2014] [Indexed: 06/03/2023]
Abstract
Effects of heating rate on slow pyrolysis behaviors, kinetic parameters, and products properties of moso bamboo were investigated in this study. Pyrolysis experiments were performed up to 700 °C at heating rates of 5, 10, 20, and 30 °C/min using thermogravimetric analysis (TGA) and a lab-scale fixed bed pyrolysis reactor. The results show that the onset and offset temperatures of the main devolatilization stage of thermogravimetry/derivative thermogravimetry (TG/DTG) curves obviously shift toward the high-temperature range, and the activation energy values increase with increasing heating rate. The heating rate has different effects on the pyrolysis products properties, including biochar (element content, proximate analysis, specific surface area, heating value), bio-oil (water content, chemical composition), and non-condensable gas. The solid yields from the fixed bed pyrolysis reactor are noticeably different from those of TGA mainly because the thermal hysteresis of the sample in the fixed bed pyrolysis reactor is more thorough.
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Affiliation(s)
- Dengyu Chen
- Materials Science & Engineering College, Nanjing Forestry University, Nanjing 210037, China.
| | - Jianbin Zhou
- Materials Science & Engineering College, Nanjing Forestry University, Nanjing 210037, China
| | - Qisheng Zhang
- Materials Science & Engineering College, Nanjing Forestry University, Nanjing 210037, China
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Srivastava AK, Yadav V, Pathak V, Singh S, Tiwari S, Bisht DS, Goloub P. Variability in radiative properties of major aerosol types: a year-long study over Delhi--an urban station in Indo-Gangetic Basin. Sci Total Environ 2014; 473-474:659-666. [PMID: 24412733 DOI: 10.1016/j.scitotenv.2013.12.064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 12/11/2013] [Accepted: 12/15/2013] [Indexed: 06/03/2023]
Abstract
Aerosol measurements over an urban site at Delhi in the western Ganga basin, northern India, were carried out during 2009 using a ground-based automatic sun/sky radiometer to identify their different types and to understand their possible radiative implications. Differentiation of aerosol types over the station was made using the appropriate thresholds for size-distribution of aerosols (i.e. fine-mode fraction, FMF at 500 nm) and radiation absorptivity (i.e. single scattering albedo, SSA at 440 nm). Four different aerosol types were identified, viz., polluted dust (PD), polluted continent (PC), mostly black carbon (MBC) and mostly organic carbon (MOC), which contributed ~48%, 32%, 11% and 9%, respectively to the total aerosols. Interestingly, the optical properties for these aerosol types differed considerably, which were further used, for the first time, to quantify their radiative implications over this station. The highest atmospheric forcing was observed for PC aerosol type (about +40 W m(-2), along with the corresponding atmospheric heating rate of 1.10 K day(-1)); whereas the lowest was for MBC aerosol type (about +25 W m(-2), along with the corresponding atmospheric heating rate of 0.69 K day(-1)).
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Affiliation(s)
- A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof. Ramnath Vij Marg, New Delhi, India.
| | - V Yadav
- Department of Civil Engineering, Institute of Engineering and Technology, Lucknow, India
| | - V Pathak
- Department of Civil Engineering, Institute of Engineering and Technology, Lucknow, India
| | - Sachchidanand Singh
- Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi, India
| | - S Tiwari
- Indian Institute of Tropical Meteorology (Branch), Prof. Ramnath Vij Marg, New Delhi, India
| | - D S Bisht
- Indian Institute of Tropical Meteorology (Branch), Prof. Ramnath Vij Marg, New Delhi, India
| | - P Goloub
- Laboratoire d'Optique Atmopshérique, Lille University/CNRS, Villeneuve d'Ascq, France
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Sanabria EA, Vaira M, Quiroga LB, Akmentins MS, Pereyra LC. Variation of thermal parameters in two different color morphs of a diurnal poison toad, Melanophryniscus rubriventris (Anura: Bufonidae). J Therm Biol 2014; 41:1-5. [PMID: 24679965 DOI: 10.1016/j.jtherbio.2014.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 11/15/2022]
Abstract
We study the variation in thermal parameters in two contrasting populations Yungas Redbelly Toads (Melanophryniscus rubriventris) with different discrete color phenotypes comparing field body temperatures, critical thermal maximum and heating rates. We found significant differences in field body temperatures of the different morphs. Temperatures were higher in toads with a high extent of dorsal melanization. No variation was registered in operative temperatures between the study locations at the moment of capture and processing. Critical thermal maximum of toads was positively related with the extent of dorsal melanization. Furthermore, we founded significant differences in heating rates between morphs, where individuals with a high extent of dorsal melanization showed greater heating rates than toads with lower dorsal melanization. The color pattern-thermal parameter relationship observed may influence the activity patterns and body size of individuals. Body temperature is a modulator of physiological and behavioral functions in amphibians, influencing daily and seasonal activity, locomotor performance, digestion rate and growth rate. It is possible that some growth constraints may arise due to the relationship of color pattern-metabolism allowing different morphs to attain similar sizes at different locations instead of body-size clines.
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Affiliation(s)
- Eduardo A Sanabria
- CONICET, Instituto de Ciencias Básicas, Facultad de Filosofía Humanidades y Artes, Universidad Nacional de San Juan, Avenida José Ignacio de la Roza 230 (O), 5400 San Juan, Argentina.
| | - Marcos Vaira
- Centro de Investigaciones y Transferencia de Jujuy (CIT-JUJUY) CONICET, Universidad Nacional de Jujuy, Av. Bolivia 1711 (4600), Jujuy, Argentina; San Salvador de Jujuy, Argentinae Instituto de Bio y Geociencias del NOA, Universidad Nacional de Salta, Salta, Argentina.
| | - Lorena B Quiroga
- Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina.
| | - Mauricio S Akmentins
- Centro de Investigaciones y Transferencia de Jujuy (CIT-JUJUY) CONICET, Universidad Nacional de Jujuy, Av. Bolivia 1711 (4600), Jujuy, Argentina; San Salvador de Jujuy, Argentinae Instituto de Bio y Geociencias del NOA, Universidad Nacional de Salta, Salta, Argentina.
| | - Laura C Pereyra
- Centro de Investigaciones y Transferencia de Jujuy (CIT-JUJUY) CONICET, Universidad Nacional de Jujuy, Av. Bolivia 1711 (4600), Jujuy, Argentina; San Salvador de Jujuy, Argentinae Instituto de Bio y Geociencias del NOA, Universidad Nacional de Salta, Salta, Argentina.
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43
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Kirtania K, Tanner J, Kabir KB, Rajendran S, Bhattacharya S. In situ synchrotron IR study relating temperature and heating rate to surface functional group changes in biomass. Bioresour Technol 2014; 151:36-42. [PMID: 24189382 DOI: 10.1016/j.biortech.2013.10.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 10/07/2013] [Accepted: 10/10/2013] [Indexed: 06/02/2023]
Abstract
Three types of woody biomass were investigated under pyrolysis condition to observe the change in the surface functional groups by Fourier transform infrared (FTIR) technique with increasing temperature under two different (5 and 150°C/min) heating rates. The experiments were carried out in situ in the infrared microscopy beamline (IRM) of the Australian Synchrotron. The capability of the beamline made it possible to focus on single particles to obtain low noise measurements without mixing with KBr. At lower heating rate, the surface functional groups were completely removed by 550°C. In case of higher heating rate, a delay was observed in losing the functional groups. Even at a high temperature, significant number of functional groups was retained after the higher heating rate experiments. This implies that at considerably high heating rates typical of industrial reactors, more functional groups will remain on the surface.
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Affiliation(s)
- Kawnish Kirtania
- Department of Chemical Engineering, Monash University, Clayton, VIC 3800, Australia
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López-González D, Fernandez-Lopez M, Valverde JL, Sanchez-Silva L. Thermogravimetric-mass spectrometric analysis on combustion of lignocellulosic biomass. Bioresour Technol 2013; 143:562-574. [PMID: 23835261 DOI: 10.1016/j.biortech.2013.06.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 06/11/2013] [Accepted: 06/14/2013] [Indexed: 06/02/2023]
Abstract
Combustion characteristics of biomass main components and three lignocellulosic biomass (fir wood, eucalyptus wood and pine bark) were investigated by thermogravimetric analysis coupled with mass spectrometry. The combustion of biomass was divided into two main steps, devolatilization and char oxidation stage. Heating rate effect was also studied. Generally, the higher the heating rate, the higher the decomposition temperature. Furthermore, the weight loss rate decreased due to particle temperature gradients. Combustion kinetics were studied. Models based on reaction order (Oi), nucleation (Ni) and diffusion (Di) achieved the best fitting to the experimental data. Cellulose oxidation presented the highest activation energies. CO, CO2 and H2O were the main components evolved from combustion. Additionally, light hydrocarbons (CH4 and C2H5) were also present. Finally, nitrogen compounds were in a higher proportion than sulfur compounds being released as primary amines and NOx.
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Affiliation(s)
- D López-González
- Department of Chemical Engineering, University of Castilla-La Mancha, Avda. Camilo José Cela 12, 13071 Ciudad Real, Spain
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