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Bhandari R, Dhital NB, Rijal K. Effect of lockdown and associated mobility changes amid COVID-19 on air quality in the Kathmandu Valley, Nepal. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1337. [PMID: 37853205 DOI: 10.1007/s10661-023-11949-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/05/2023] [Indexed: 10/20/2023]
Abstract
The COVID-19 pandemic caused a setback for Nepal, leading to nationwide lockdowns. The study analyzed the impact of lockdown on air quality during the first and second waves of the COVID-19 pandemic in the Kathmandu Valley. We analyzed 5 years of ground-based air quality monitoring data (2017-2021) from March to July and April to June for the first and second wave lockdowns, respectively. A significant decrease in PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm) concentrations was observed during the lockdowns. The highest rate of decline in PM2.5 levels was observed during May and July compared to the pre-pandemic year. The PM2.5 concentration during the lockdown period remained within the WHO guideline limit and NAAQS for the maximum number of days compared to the lockdown window in the pre-pandemic years (2017-2019). Likewise, lower PM2.5 levels were observed during the second wave lockdown, which was characterized by a targeted lockdown approach (smart lockdown). We found a significant correlation of PM2.5 concentration with community mobility changes (i.e., walking, driving, and using public transport) from the Spearman correlation analysis. Lockdown measures restricted human mobility that led to a lowering of PM2.5 concentrations. Our findings can be helpful in developing urban air quality control measures and management strategies, especially during high pollution episodes.
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Affiliation(s)
- Rikita Bhandari
- Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal.
| | - Narayan Babu Dhital
- Department of Environmental Science, Patan Multiple Campus, Tribhuvan University, Lalitpur, Nepal
| | - Kedar Rijal
- Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
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Ecological Transition in the Field of Brake Pad Manufacturing: An Overview of the Potential Green Constituents. SUSTAINABILITY 2022. [DOI: 10.3390/su14052508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nowadays, the drive for green products has undergone a rapid increase following the global ecoawareness and the severe regulations aimed at preventing the environment from further damage. The use of ecosafe constituents in materials for harsh applications, such as brake pad systems, can be a possible solution for reducing health hazards arising from particle release during braking. Based on this, the present study provides a bibliographic review of green alternative constituents for friction material formulation, focusing the attention on their influence on the tribological properties of the final composites. The traditional materials still used in commercial brake pads are shortly described, with the aim to provide an overview of the current situation. In the final part of the review, following the trend of circular economy, works dealing with the use of waste as an ingredient of friction materials are also reported. The whole literature screening points out that much work is still required to obtain completely green friction materials. Indeed, few works dealing with the phenolic resin replacement, proposing inorganic ecosafe materials such as geopolymers, are present. On the contrary, the use of natural fibers is widely investigated: palm kernel, flax, agave and aloe can be identified as promising constituents based on the literature results and the generated patents.
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Hu B, Ouyang G. In situ solid phase microextraction sampling of analytes from living human objects for mass spectrometry analysis. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116368] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Huang Y, Li Y, Luo Q, Huang X. One-Pot Strategy as a Green and Rapid Method to Fabricate Magnetic Molecularly Imprinted Nanoparticles for Selective Capture of Sulfonylurea Herbicides. ACS APPLIED MATERIALS & INTERFACES 2021; 13:37280-37288. [PMID: 34324296 DOI: 10.1021/acsami.1c11433] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetic solid-phase extraction (MSPE) based on molecularly imprinted nanoparticles (MINs) has attracted wide attention in sample pretreatment because it combines the merits of high selectivity and quick extraction procedures. However, laborious, time and solvent-consuming steps were involved in the synthesis of magnetic imprinted particles in existing approaches. To circumvent this dilemma, a green and rapid "one-pot" strategy was proposed to prepare MINs. Halosulfuron-methyl (HSM) was selected as a template molecule, and Gaussian 09 simulation software was employed to screen the 2,4,6-trivinylboroxin pyridine complex (TBP) as a functional monomer. Subsequently, the fabrication was simply conducted using a hydrothermal approach by mixing self-assembly solution of TBP-HSM, Fe3+, Fe2+, dimethyl sulfoxide, and azobisisobutyronitrile in one-pot with a total reaction time of 3.0 h. Various characterized results well evidenced the successful imprint of HSM and the resultant HSM-MINs presented satisfying superparamagnetism and saturation magnetism. Under the optimized parameters, the obtained HSM-MINs displayed good recognition capability and selectivity toward HSM (recognition coefficient was 2.60), as well as a satisfactory saturation adsorption capacity (1781 μg/g). The quantification of sulfonylurea herbicides at trace levels in environmental water and soil samples was selected as a paradigm to demonstrate the practicality and reliability of HSM-MINs/MSPE. The present study provides a convenient, reliable, and green approach for fabricating a magnetic molecular-imprinting adsorbent for MSPE.
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Affiliation(s)
- Youfang Huang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems; Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies; College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Yanyun Li
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Qing Luo
- Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, Fujian 361005, China
| | - Xiaojia Huang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems; Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies; College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
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Yang J, Wang Y, Pan M, Xie X, Liu K, Hong L, Wang S. Synthesis of Magnetic Metal-Organic Frame Material and Its Application in Food Sample Preparation. Foods 2020; 9:E1610. [PMID: 33172006 PMCID: PMC7694616 DOI: 10.3390/foods9111610] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022] Open
Abstract
A variety of contaminants in food is an important aspect affecting food safety. Due to the presence of its trace amounts and the complexity of food matrix, it is very difficult to effectively separate and accurately detect them. The magnetic metal-organic framework (MMOF) composites with different structures and functions provide a new choice for the purification of food matrix and enrichment of trace targets, thus providing a new direction for the development of new technologies in food safety detection with high sensitivity and efficiency. The MOF materials composed of inorganic subunits and organic ligands have the advantages of regular pore structure, large specific surface area and good stability, which have been thoroughly studied in the pretreatment of complex food samples. MMOF materials combined different MOF materials with various magnetic nanoparticles, adding magnetic characteristics to the advantages of MOF materials, which are in terms of material selectivity, biocompatibility, easy operation and repeatability. Combined with solid phase extraction (SPE) technique, MMOF materials have been widely used in the food pretreatment. This article introduced the new preparation strategies of different MMOF materials, systematically summarizes their applications as SPE adsorbents in the pretreatment of food contaminants and analyzes and prospects their future application prospects and development directions.
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Affiliation(s)
- Jingying Yang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yabin Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Mingfei Pan
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xiaoqian Xie
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Kaixin Liu
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Liping Hong
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Shuo Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; (J.Y.); (Y.W.); (M.P.); (X.X.); (K.L.); (L.H.)
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China
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