Safety and associated parameters influencing performance of rail road grade crossings: A critical review of state of the art

INTRODUCTION

Railroad grade crossings (RRGCs) have emerged as critical transportation infrastructures from the point of safety and operational aspects because two modes of transportation intermingle at the intersecting zone; the understanding of safety and traffic operation at RRGC is of prime concern while planning and designing this transportation facility.

METHOD

In this context, this work tries to comprehend RRGC performance-related parameters from published literature and figure out critical gaps. An international synthesis on the identified potential parameters influencing the RRGC performance (i.e., safety, driver behavior, and operational impact) was carried out by critically reviewing the articles published worldwide. Furthermore, key findings, used variables, analysis methods, research gaps, and recommendations were studied.

RESULTS

The review revealed that many researchers had explored the driver behavior and safety aspect based on past crash data and violations prevailing at RRGC. However, little research has been done to evaluate the effect of highways' operational characteristics on the performance of RRGC. Moreover, limited investigation has been carried out to understand the dilemma of drivers and the proactive safety evaluation of pedestrians and non-motorized vehicles at RRGC. A total of seven critical research gaps concerning parameters are recognized, facilitating a clear agenda for further research pertaining to RRGC performance.

Beyond financial proxies in Cohesion Policy inputs' monitoring: A system dynamics approach

European Union's Cohesion Policy aims to foster development and reduce disparities among regions by redistributing more than one-third of the European budget. Given the policy's importance and complexity, an elaborated monitoring and evaluation system has been established. While attention has been dedicated to evaluating policy impact, the monitoring of inputs (i.e., allocated financial resources) has been limited to the control of financial dimensions (i.e., funds' absorption rate). As the implementation process entails a sequence of steps, this research explores whether financial proxies alone are adequate to monitor the policy inputs. To test this hypothesis, a system dynamics model is built. Simulations highlight that the absorption rate captures shocks that might occur during the inputs' expenditure with significant delay. To that end, we elaborate three novel operative monitoring indicators (i.e., funds' demand, funds' offer, procedural efficiency), which may overcome the financial indicators' mono-dimensionality and time lags' limitations.

Cellular automata based framework for evaluating mitigation strategies of sponge city

Urban surface water flooding is increasing because of climate change and urbanization, and brings great challenges to urban sustainable development. It is, therefore, most important to develop urban flood management approaches to alleviate the consequences of floods. China is implementing a "sponge city" initiative to tackle urban surface water flooding and improve urban water management. There is, however, limited cost-effectiveness evaluation to support the choice of economically efficient mitigation strategies. To address this gap, this study developed an evaluation framework based on cellular automata and cost-benefit analysis to assess the performance of mitigation strategies in sponge city construction. This approach is demonstrated with a case study of Siergou (Dalian, China), which has a total area of 10.1 km². The mitigation measures of green roofs, permeable pavements and bio-retention were used to generate mitigation scenarios. A two-dimensional cellular automata-based model was used to simulate urban surface water flooding. The results obtained from the case study indicate that the framework can achieve cost-effective mitigation strategies for sponge city construction, which can support robust decision making. The distribution of mitigation strategies has great impacts on the effectiveness of alleviating urban flood risk. This study provides new insight into the development of cost-effective mitigation strategies for sponge city construction.

Prediction methods for microRNA targets in bilaterian animals: Toward a better understanding by biologists

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level. Because of their wide network of interactions, miRNAs have become the focus of many studies over the past decade, particularly in animal species. To streamline the number of potential wet lab experiments, the use of miRNA target prediction tools is currently the first step undertaken. However, the predictions made may vary considerably depending on the tool used, which is mostly due to the complex and still not fully understood mechanism of action of miRNAs. The discrepancies complicate the choice of the tool for miRNA target prediction. To provide a comprehensive view of this issue, we highlight in this review the main characteristics of miRNA-target interactions in bilaterian animals, describe the prediction models currently used, and provide some insights for the evaluation of predictor performance.

Performance evaluation of surrogate measures of safety with naturalistic driving data

Surrogate measures of safety (SMoS) play an important role in detecting traffic conflicts and in traffic safety assessment. However, the underlying assumptions of SMoS are different and a certain SMoS may be adequate/inadequate for different applications. A comprehensive approach to evaluate the validity and applicability of SMoS is lacking in the literature. This study proposes such a framework that supports evaluating SMoS in multiple dimensions. We apply the framework to gain insights into the characteristics of six widely-used SMoS for longitudinal maneuvers, i.e., Time to Collision (TTC), single-step Probabilistic Driving Risk Field (S-PDRF), Deceleration Rate to Avoid a Crash (DRAC), Potential Index for Collision with Urgent Deceleration (PICUD), Proactive Fuzzy Surrogate Safety Metric (PFS), and the Critical Fuzzy Surrogate Safety Metric (CFS). To ensure comparability, all measures are calibrated with the same risk detection criterion. Four performance indicators, i.e., Prediction Accuracy, Timeliness, Robustness, and Efficiency are computed for all six SMoS and validated using naturalistic driving data. The strengths and weaknesses of all six measures are compared and analyzed elaborately. A key result is that not a single SMoS performs well in all performance dimensions. S-PDRF performs best in terms of Robustness but consumes the most time for computation. TTC is the most efficient but performs poorly in terms of Timeliness and Robustness. The proposed evaluation approach and the derived insights can support SMoS selection in active vehicle safety system design and traffic safety assessment.

Featured services and performance of BDS-3

BeiDou Global Navigation Satellite System (BDS-3) not only performs the normal positioning, navigation and timing (PNT) functions, but also provides featured services, which are divided into geostationary orbit (GEO) and medium earth orbit (MEO) satellite-based featured services in this paper. The former refers to regional services consisting of the regional short message communication service (RSMCS), the radio determination satellite service (RDSS), the BDS satellite-based augmented service (BDSBAS) and the satellite-based precise point positioning service via B2b signal (B2b-PPP). The latter refers to global services consisting of the global short message communication service (GSMCS) and the MEO satellite-based search and rescue (MEOSAR) service. The focus of this paper is to describe these featured services and evaluate their performances. The results show that the inter-satellite link (ISL) contributes a lot to the accuracy improvement of orbit determination and time synchronization for the whole constellation. Compared with some other final products, the root mean squares (RMS) of the BDS-3 precise orbits and broadcast clock are 25.1 cm and 2.01 ns, respectively. The positioning accuracy of single frequency is better than 6 m, and that of the generalized RDSS is usually better than 12 m. For featured services, the success rates of RSMCS and GSMCS are better than 99.9% and 95.6%, respectively; the positioning accuracies of single and dual frequency BDSBAS are better than 3 and 2 m, respectively; the positioning accuracy of B2b-PPP is better than 0.6 m, and the convergence time is usually smaller than 30 min; the single station test shows that the success rate of MEOSAR is better than 99%. Due to the ISL realization in the BDS-3 constellation, the performance and capacities of the global featured services are improved significantly.

Performance evaluation of an EMS system using queuing theory and location analysis: A case study

In emergency medical services (EMS), response time is a key factor that shows the performance of the system. This factor is composed of two parts including activation time and travel time. The activation time of an emergency call is the time a call center spends on taking an incoming call for EMS and decides whether an ambulance should be dispatched or the emergency can be resolved by giving some medical advices. Having a good number of call center operators including call takers and dispatchers can help to reduce this time and thus the response time. However, this alone may not be enough to have a reasonable cycle time. In fact, having idle ambulances located in right places when emergency calls occur is an influential factor to reduce the travel time and thus have an optimal response time and save people's lives. Although many researchers have studied improving either the activation time or the travel time, to the best of our knowledge, there exists no study focusing on both. Motivated by this gap, in this study, a framework is proposed which uses queuing theory and location analysis to address both activation and travel times. In this regard, first, queuing theory is applied to evaluate the performance of an EMS call center and reduce the average activation time. Then, three mathematical models including mobile stations, MEXCLP and MECRP are applied to locate ambulances such that the average travel time is minimized. To shed light on the merits of using queuing theory and location models, computational results based on the real-world data from Tehran EMS Center are provided. The proposed methodology can reduce the average response time by approximately four minutes and increase the average coverage by 35%. This work is an example of the tremendous positive impact that the application of queuing theory and mathematical modeling can have. The proposed framework can significantly decrease the cycle time and increase the ambulance coverage level. The findings of this study help the policy makers of EMS centers with evaluating the performance of their systems and determining the optimal number of operators and locations of ambulances in a way that enhances the quality of emergency services.

Investigation into cavitational intensity and COD reduction performance of the pinned disc reactor with various rotor-stator arrangements

In this study, the hydrodynamic cavitation and wastewater treatment performance of a rotary generator with pin disk for hydrodynamic cavitation are investigated. Various geometrical features and arrangements of rotor and stator pins were evaluated to improve the configuration of the cavitation device. The pilot device used to perform the experiments was upgraded with a transparent cover that allows visualization of the hydrodynamic cavitation in the rotor-stator region with high-speed camera and simultaneous measurement of pressure fluctuations. Based on the hydrodynamic characteristics, three arrangements were selected and evaluated with respect to the chemical effects of cavitation on a 200-liter wastewater influent sample. The experimental results show that the rotational speed and the spacing of the rotor pins have the most significant effect on the cavitation intensity and effectiveness, while the pin diameter and the surface roughness are less significant design parameters. Cavitation intensity increases with pin velocity, but can be inhibited if the pins are arranged too close together. At best configuration, COD was reduced by 31% in 15 liquid passes, consuming 8.2 kWh/kg COD. The number of liquid passes also proved to be an important process parameter for improving the energy efficiency.

Heterojunction photocatalysts for degradation of the tetracycline antibiotic: a review

Antibiotic pollution is a major health issue inducing antibiotic resistance and the inefficiency of actual drugs, thus calling for improved methods to clean water and wastewater. Here we review the recent development of heterojunction photocatalysis and application in degrading tetracycline. We discuss mechanisms for separating photogenerated electron-hole pairs in different heterojunction systems such as traditional, p-n, direct Z-scheme, step-scheme, Schottky, and surface heterojunction. Degradation pathways of tetracycline during photocatalysis are presented. We compare the efficiency of tetracycline removal by various heterojunctions using quantum efficiency, space time yield, and figures of merit. Implications for the treatment of antibiotic-contaminated wastewater are discussed.

Nature-based solutions efficiency evaluation against natural hazards: Modelling methods, advantages and limitations

Nature-based solutions (NBS) for hydro-meteorological risks (HMRs) reduction and management are becoming increasingly popular, but challenges such as the lack of well-recognised standard methodologies to evaluate their performance and upscale their implementation remain. We systematically evaluate the current state-of-the art on the models and tools that are utilised for the optimum allocation, design and efficiency evaluation of NBS for five HMRs (flooding, droughts, heatwaves, landslides, and storm surges and coastal erosion). We found that methods to assess the complex issue of NBS efficiency and cost-benefits analysis are still in the development stage and they have only been implemented through the methodologies developed for other purposes such as fluid dynamics models in micro and catchment scale contexts. Of the reviewed numerical models and tools MIKE-SHE, SWMM (for floods), ParFlow-TREES, ACRU, SIMGRO (for droughts), WRF, ENVI-met (for heatwaves), FUNWAVE-TVD, BROOK90 (for landslides), TELEMAC and ADCIRC (for storm surges) are more flexible to evaluate the performance and effectiveness of specific NBS such as wetlands, ponds, trees, parks, grass, green roof/walls, tree roots, vegetations, coral reefs, mangroves, sea grasses, oyster reefs, sea salt marshes, sandy beaches and dunes. We conclude that the models and tools that are capable of assessing the multiple benefits, particularly the performance and cost-effectiveness of NBS for HMR reduction and management are not readily available. Thus, our synthesis of modelling methods can facilitate their selection that can maximise opportunities and refute the current political hesitation of NBS deployment compared with grey solutions for HMR management but also for the provision of a wide range of social and economic co-benefits. However, there is still a need for bespoke modelling tools that can holistically assess the various components of NBS from an HMR reduction and management perspective. Such tools can facilitate impact assessment modelling under different NBS scenarios to build a solid evidence base for upscaling and replicating the implementation of NBS.

Anisotropic ZnO nanostructures and their nanocomposites as an advanced platform for photocatalytic remediation

In pursuit of advanced heterogeneous photocatalysts, ZnO has emerged as a promising option for solar-driven heterogeneous photocatalyst with many advantageous properties (e.g., optical band structure and electronic properties). However, as the efficacy of such system can also be limited by a number of demerits (e.g., fast recombination of charge carriers and limited photon absorption), considerable efforts are needed for its effective and practical scale-up. This article provides a detailed literature review of the synthesis and modification of ZnO nanostructures with tuned band structures and controllable morphologies for solar light harvesting. The potential of anisotropic ZnO nanostructures is also discussed with respect to the photocatalytic degradation of organic/inorganic water pollutants. Further, the role of various metal dopants is discussed for the enhancement of photocatalytic activity along with evaluation of their photocatalytic performances under UV-visible or solar irradiation. Finally, our discussions are expanded to describe the prospects of developed ZnO nano-photocatalysts for real-world applications with respect to light-harvesting efficiency and mechanical stability.

Performance evaluation of FAO Penman-Monteith and best alternative models for estimating reference evapotranspiration in Bangladesh

Proper assessment of reference evapotranspiration (ET₀) is necessary for pastoral activity and water management. The Penman-Monteith FAO56 (ET_pmf) method has been recommended as the identical ET₀ estimation model; nonetheless, it belongs to a vast climatic data requirement. There is an urgent need to discover an ideal alternate model for evaluating ET₀ in particular places where all climatic data is insufficient. The performances of 15 empirical models were assessed to get the best alternative model by comparing it with the PMF-56 model. These 15 models were evaluated by employing a daily scatter plot and three well known numerical approaches: relative root-mean-square error, mean absolute error and Nash–Sutcliffe coefficient in this study. Furthermore, a linear regression model was implemented to calibrate and validate the empirical models' performances throughout the 1981–2005 and 2006–2018 time intervals, separately. The outcomes displayed that the ET_pmf rose primarily and declined later on a monthly period with the topmost amount in April and the lowermost amount in January. Overall, the Abtew model was the best alternate method showing the highest determination coefficient values more than 0.85 from January to December. In contrast, the Penman, WMO, Trabert, Valiantzas1, Valiantzas2, Valiantzas3 and Jensen-Haise models presented moderate performances with fewer inaccuracies. Afterwards, modification, the version of the above-described models every month has been upgraded deliberately related to actual. The Abtew model had simplicity in the computation process, only used maximum temperature and solar radiation data and linearly well connected to the PMF-56 model.

Development and implementation of standardized study performance metrics for a VA healthcare system clinical research consortium

The cost of conducting clinical trials is continuously increasing and is driven in large part by the time and resources required to activate trials and reach accrual targets. The impact of low enrollment in a clinical trial can negatively affect the validity of study results and delay its generalizability to the broader population. Quality is a multidimensional concept which could relate to the design, conduct, and analysis of a trial, its clinical relevance, protection/safety of study participants, or quality of reporting. Furthermore, the quality of controlled trials is of obvious relevance to systematic reviews and if the "raw material" or "data" is flawed then the conclusions of systematic reviews cannot be trusted. To date, the literature surrounding the establishment of standardized study enrollment and quality metrics to assess site performance in clinical trial consortiums is scarce. The lack of these metrics presents challenges to study site teams, sponsors, and other clinical research enterprise key stakeholders for adequately monitoring and evaluating study site performance as it relates to fulfilling trial enrollment and quality goals. The Department of Veterans Affairs (VA) Cooperative Studies Program (CSP) Network of Dedicated Enrollment Sites (NODES) undertook an effort to determine the feasibility of establishing and implementing standardized study enrollment and quality metrics for a clinical research consortium (NODES) as a tool to evaluate its performance. In this manuscript, we describe the development and implementation of standardized study enrollment and quality metrics to assess site performance across studies in our clinical research consortium.

Clinical performance evaluation of SARS-CoV-2 rapid antigen testing in point of care usage in comparison to RT-qPCR

BACKGROUND

Antigen rapid diagnostic tests (RDT) for SARS-CoV-2 are fast, broadly available, and inexpensive. Despite this, reliable clinical performance data from large field studies is sparse.

METHODS

In a prospective performance evaluation study, RDT from three manufacturers (NADAL®, Panbio™, MEDsan®, conducted on different samples) were compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) in 5 068 oropharyngeal swabs for detection of SARS-CoV-2 in a hospital setting. Viral load was derived from standardised RT-qPCR Cycle threshold (Ct) values. The data collection period ranged from November 12, 2020 to February 28, 2021.

FINDINGS

The sensitivity of RDT compared to RT-qPCR was 42·57% (95% CI 33·38%-52·31%). The specificity was 99·68% (95% CI 99·48%-99·80%). Sensitivity declined with decreasing viral load from 100% in samples with a deduced viral load of ≥108 SARS-CoV-2 RNA copies per ml to 8·82% in samples with a viral load lower than 104 SARS-CoV-2 RNA copies per ml. No significant differences in sensitivity or specificity could be observed between samples with and without spike protein variant B.1.1.7. The NPV in the study cohort was 98·84%; the PPV in persons with typical COVID-19 symptoms was 97·37%, and 28·57% in persons without or with atypical symptoms.

INTERPRETATION

RDT are a reliable method to diagnose SARS-CoV-2 infection in persons with high viral load. RDT are a valuable addition to RT-qPCR testing, as they reliably detect infectious persons with high viral loads before RT-qPCR results are available.

FUNDING

German Federal Ministry for Education and Science (BMBF), Free State of Bavaria.

Aligning efficiency benchmarking with sustainable outcomes in the United Kingdom water sector

The provision of fundamental services by water and sewage companies (WaSCs) requires substantial energy and material inputs. A sustainability assessment of these companies requires a holistic evaluation of both performance and efficiency. The Hicks-Moorsteen productivity index was applied to 12 WaSCs in the United Kingdom (UK) over a 6-year period to benchmark their sustainability, based on eight approaches using different input and output variables for efficiency assessment. The choice of variables had a major influence on the ranking and perceived operational efficiency among WaSCs. Capital expenditure (utilised as part of total expenditure) for example, is an important input for tracking company operations however, potential associated efficiency benefits can lag investment, leading to apparent poor short-term performance following capital expenditure. Furthermore, water supplied and wastewater treated was deemed an unconstructive output from a sustainability perspective since it contradicts efforts to improve sustainability through reduced leakage and consumption per capita. Customer satisfaction and water quality measures are potential suitable alternatives. Despite these limitations, total expenditure and water supplied and wastewater treated were used alongside customer satisfaction and self-generated renewable energy for a holistic sustainability assessment within a small sample. They indicated the UK water sector has improved in productivity by 1.8% on average for 2014-18 and still had room for improvement, as a technical decline was evident for both the best and worst performers. Collectively the sample's production frontier was unchanged but on average companies moved 2.1% closer to it, and further decomposition of productivity revealed this was due to improvements in economies of scale and scope. Careful selection of appropriate input and output variables for efficiency benchmarking across water companies is critical to align with sustainability objectives and to target future investment and regulation within the water sector.

Performance evaluation of medical service for breast cancer patients based on diagnosis related groups

Background

To evaluate the performance of medical service for patients with breast cancer in Henan Province, China, using diagnosis related groups (DRGs) indicators and to provide data to inform practices and policies for the prevention and control of breast cancer.

Methods

The data were collected from the front pages of medical records (FPMR) of all hospitals above class II that admitted breast cancer patients in Henan Province between 2016 and 2019. Breast cancer patients were the subjects in our study. China DRGs (CN-DRGs) was used as a risk adjustment tool. Three indicators, including the case mix index (CMI), number of DRGs, and total weight, were used to evaluate the range of available services for patients with breast cancer, while indicators including the charge efficiency index (CEI), time efficiency index (TEI) and inpatient mortality of low-risk group cases (IMLRG) were used to evaluate medical service efficiency and medical safety.

Results

Between 2016 and 2019, there were 103,760 patients with breast cancer. The total weight increased over the study period at an average annual rate of 21.71%. The TEI decreased over the study period by 15.60%. The CEI exhibited an increasing trend, but the average annual rate of increase was small (2.94%). The IMLRP was 0.02, 0, 0 and 0.01% in 2016, 2017, 2018 and 2019, respectively.

Conclusion

The performance of medical service improved between 2016 and 2019 for breast cancer patients discharged from study hospitals in Henan Province. The main area of improvement was in the range of available services, but medical institutions must still make efforts to improve the efficiency of medical services and ensure medical safety. DRGs is an effective evaluation tool.

Evaluation of staff nurses performance in Level III private hospitals in Region IV-A basis for continuing professional development program

This study determined the clinical performance of staff nurses in Level III private hospitals. Determination of the clinical competency measured using the questionnaire checklist adopted from the nursing core competency standards. Results indicated that the overall clinical performance of staff nurses in the Beginning Nurses' Role in Client Care, Leadership and Management, and Research are competent based on the evaluation of respondents. Staff nurses' performance, according to profile divulges no significant difference in client care, leadership, and management, while a significant difference is found in research when the highest educational attainment and location of hospital affiliation are considered. Evaluation of those with master's degree is significantly higher than those with bachelor's degree and with master's units. In terms of the current position, the findings disclosed a significant difference in beginning nurses' roles in leadership and management. The correlation of client care, leadership, and management, and research revealed a directly proportional relationship.

Performance evaluation for the design of a hybrid cloud based distance synchronous and asynchronous learning architecture

The COVID-19 emergency suddenly obliged schools and universities around the world to deliver on-line lectures and services. While the urgency of response resulted in a fast and massive adoption of standard, public on-line platforms, generally owned by big players in the digital services market, this does not sufficiently take into account privacy-related and security-related issues and potential legal problems about the legitimate exploitation of the intellectual rights about contents. However, the experience brought to attention a vast set of issues, which have been addressed by implementing these services by means of private platforms. This work presents a modeling and evaluation framework, defined on a set of high-level, management-oriented parameters and based on a Vectorial Auto Regressive Fractional (Integrated) Moving Average based approach, to support the design of distance learning architectures. The purpose of this framework is to help decision makers to evaluate the requirements and the costs of hybrid cloud technology solutions. Furthermore, it aims at providing a coarse grain reference organization integrating low-cost, long-term storage management services to implement a viable and accessible history feature for all materials. The proposed solution has been designed bearing in mind the ecosystem of Italian universities. A realistic case study has been shaped on the needs of an important, generalist, polycentric Italian university, where some of the authors of this paper work.

Performance of sewage treatment plants and impact of effluent discharge on receiving water quality within an urbanized area

In Brazil, wastewater treatment coverage is low. Even when treatment is carried out, many municipalities cannot achieve adequate levels of contaminant removal, and the usual practice of releasing raw or treated domestic effluent into water bodies remains. Thus, this pollution source puts pressure on water resources, compromising downstream uses of the disposal. This study has two aims: (1) to evaluate the performance of sewage treatment plants and (2) to determine the impact of discharging treated effluent on the water quality of receiving water bodies located within an urbanized area in the Velhas River basin, Minas Gerais State, Brazil. Monitoring data from raw wastewater were compared with typical ranges reported in literature, and effluent concentrations were compared between plants. The monitoring data of the receiving water bodies collected at points upstream and downstream of each disposal were statistically compared. Different performances between the systems and significant alterations in the receiving bodies resulting from the discharge of the treated effluents were found.

Standardized method for material flow data collection at city level

The collection of material flow data is the first step in the evaluation of the circular economy performance and material metabolism at the city level. However, Chinese statistical data are published by Chinese National Bureau of Statistics, and provincial and municipal Bureau of Statistics. This resulted in data being scattered in dispersed sources and varying between cities, even brings about mistakes. Therefore, we established a standardized data collection and accounting method with regular data sources for Chinese cities. In this data collection method, material flow accounting mainly consists of three parts: direct material input, material recycling, and waste disposal. It covers four types of materials, including fossil fuels, biomass, metal minerals, and non-metallic minerals with 155 items. We combined the data sources for the material flow accounting within a standardized Excel spreadsheet with detailed information on statistical data sources and equations to convert the information into material flow data. The statistical data were derived from the China City Statistical Yearbook, the provincial Statistic Yearbook, and the city's statistical yearbook. The estimated data in the material accounting were obtained by converting statistical data using relative coefficients. According to the main sources and features of materials use, the intersectoral material flows can also be estimated following this standardized method for urban metabolism analysis, circular economy performance evaluation, and ecological network analysis. The standardized method for material flow data collection was adopted in the article "H. Gao, X. Tian, Y. Zhang, L. Shi, F. Shi, 2021. Evaluating circular economy performance based on ecological network analysis: A framework and application at city level. 105257. Resources, Conservation & Recycling. https://doi.org/10.1016/j.resconrec.2020.105257".

Sustainability assessment of existing onshore wind plants in the context of triple bottom line: a best-worst method (BWM) based MCDM framework

Not only the steadily growing demand for electricity generation but also the environmental concerns in recent years have led to the belief in the importance of renewable energy. Wind is one of the most important renewable energy sources utilized in electricity generation for a sustainable environment. This paper deals with performance assessment for existing onshore wind plants in terms of triple bottom line of sustainability and aims to propose a structural methodology. Furthermore, the proposed framework is essentially formed through two stages: the first stage is the determination of relative weights for sustainability factors through the best-worst method (BWM) and the second stage is a sustainability performance assessment of the available 42 wind plants in Izmir, Turkey. According to the findings, the environmental dimension is the most significant, followed by the economic and social dimensions. The results also reveal that distance to protected areas is the most important factor among others in terms of sustainability performance and that the wind plants throughout the north side of Izmir have a higher sustainability performance. To validate the robustness and reliability of the introduced framework, a sensitivity analysis is also conducted. The proposed framework could be employed successfully in other scientific applications.

Assessing Industrial Robot agility through international competitions

Manufacturing and Industrial Robotics have reached a point where to be more useful to small and medium sized manufacturers, the systems must become more agile and must be able to adapt to changes in the environment. This paper describes the process for creating and the lessons learned over multiple years of the Agile Robotics for Industrial Automation Competition (ARIAC) being run by the National Institute of Standards and Technology.

Performance evaluation of a decentralized rooftop solar photovoltaic system with a heat recovery cooling unit

The present work represents a detailed performance analysis of a 5-kW_p on-grid solar photovoltaic rooftop system installed on a flat roof of a hospital building at a height of 12 m from the ground level, located at Perambalur (latitude 11° 23' N and longitude 78° 93' E), Tamilnadu, India. The daily, monthly and annual average performance parameters of the PV system including energy output, final yield, reference yield, array yield, photovoltaic array efficiency, system efficiency, inverter efficiency, performance ratio and capacity utilization factor have been analysed. The environmental benefit analysis and the payback period of the installed solar photovoltaic plant are also discussed. This solar photovoltaic power plant generates around 7144 kWh per annum of electrical energy, which is fed into the grid, and the annual average array, inverter, system efficiency, capacity utilization factor and performance ratio of the plant are found to be 12.15%, 97.12%, 11.72%, 16.31% and 76.83%, respectively, during the year 2019. The overall PV module electrical efficiency has been increased by 1.21% by applying the forced air circulation mechanism and 2.31% by applying the forced water circulation mechanism. Subsequently, the heat gained by the system can be utilized for heat load application. The installed solar photovoltaic power plant has a positive impact on greenhouse gas emissions with a reduction of 11.287 t of CO₂, 8.86 kg of SO₂, 18.50 kg of NO_x and 485.792 kg of ash per annum. The water-based cooling in photovoltaics can potentially generate an output energy of 7310 kWh, which is relatively higher than the energy generated by the photovoltaic module with air cooling.

Performance evaluation of a novel pilot-scale pinned disc rotating generator of hydrodynamic cavitation

This study investigates hydrodynamic performance of a novel pinned disc rotating generator of hydrodynamic cavitation in comparison with a serrated disc variant on a pilot-scale. Experimental results show that at a given rotational speed and liquid flow rate, the pinned disc generates more intense cavitation (i.e. lower cavitation number, higher volume fraction of vapor and higher amplitude of pressure fluctuations) than the serrated disc, while also consuming less energy per liquid pass (i.e., higher flow rate and pumping pressure difference of water at similar power consumption). Additionally, mechanical and chemical wastewater treatment performance of the novel cavitator was evaluated on an 800 L influent sample from a wastewater treatment plant. Mechanical effects resulted in a reduction of average particle size from 148 to 38 µm and increase of specific surface area, while the oxidation potential was confirmed by reduction of COD, TOC, and BOD up to 27, 23 and 30% in 60 cavitation passes, respectively. At optimal operating conditions and 30 cavitation passes, pinned disc cavitator had a 310% higher COD removal capacity while consuming 65% less energy per kg of COD removed than the serrated disc cavitator. Furthermore, the specific COD-reduction energy consumption of the pinned disc cavitator on the pilot scale is comparable to the best cases of lab-scale orifice and venturi devices operating at much lower wastewater processing capacity.

Thermal, hygric, and environmental performance evaluation of thermal insulation materials for their sustainable utilization in buildings

As energy use in the building sector is increasing worldwide, building materials with characteristics that save energy are becoming increasingly important; in addition, there is an emerging need for high-performance insulation materials with low thermal conductivity. However, thermal insulation should consider thermal conductivity, which is the main performance parameter, in addition to the water adsorption rate, acidity, and deformation and expansion due to drying conditions. This study evaluated the main performance of 21 insulation materials used at construction sites to objectively and clearly evaluate their overall performance, including their thermal conductivity. Thermal conductivity was measured by the heat flow meter method according to ASTM C518 and ISO 8301 standards; it was also evaluated according to the drying conditions. The water absorption rate was evaluated by ISO 2896 to ensure the sustainability and long-term thermal conductivity performance of the material. Acidity was evaluated with ASTM E861 to reduce the environmental load of the buildings and soil. The results of this study reviewed an appropriate method to measure the main performance according to the type of insulation.