Sustainability

25 pages, 3574 KiB

Open AccessArticle

Using the Entropy and TOPSIS Models to Evaluate Sustainable Development of Islands: A Case in China

by Ding-Yi Zhao, Yu-Yu Ma and Hung-Lung Lin

Sustainability 2022, 14(6), 3707; https://doi.org/10.3390/su14063707 - 21 Mar 2022

Cited by 23 | Viewed by 3733

China is a major maritime country with numerous islands, which are rich in natural resources. Island resources exhibit excellent development potential; in this regard, the market demand for uninhabited island development has been strong. The scientific and reasonable utilization of the resources of [...] Read more.

China is a major maritime country with numerous islands, which are rich in natural resources. Island resources exhibit excellent development potential; in this regard, the market demand for uninhabited island development has been strong. The scientific and reasonable utilization of the resources of uninhabited islands can create huge economic value for the region and the country, inject vitality into the national economy, and enhance the stability of the overall sustainable development of the national economy. However, previous research on islands focused on a limited area of economy or ecology, and few studies provide a comprehensive evaluation of uninhabited island development. Such development requires enormous investment and has a profound impact. Therefore, a comprehensive and scientific evaluation system is necessary for uninhabited island development planning. This paper accordingly develops an island planning and evaluation indicator system based on multi-criteria decision-making (MCDM), and entropy analysis method, and the approach of Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). A validation analysis was conducted to prove the effectiveness of the evaluation system. The evaluation system comprehensively considers both economic and ecological factors, which makes up for the one-sidedness of the previous evaluation focusing on economy or ecology, and effectively ensures the sustainable development of island development. In this regard, the evaluation system can provide important guidance for the government’s island planning management and the investment decision-making of enterprises. This system can also provide new ideas for the sustainable development of islands. Full article

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20 pages, 3565 KiB

Open AccessArticle

A Study on the Optimization of In-Process Inspection Procedure for Active Pharmaceutical Ingredients Manufacturing Process

by Taho Yang, Shin-Yi Lin, Yu-Hsiu Hung and Chung-Chien Hong

Sustainability 2022, 14(6), 3706; https://doi.org/10.3390/su14063706 - 21 Mar 2022

Cited by 3 | Viewed by 3172

Abstract

The in-process inspection procedure is one of the critical operations in the active pharmaceutical ingredients manufacturing process. This study aims to improve the performance of the IPI service system in terms of three main criteria, namely service level, cycle time, and maximum tardy [...] Read more.

The in-process inspection procedure is one of the critical operations in the active pharmaceutical ingredients manufacturing process. This study aims to improve the performance of the IPI service system in terms of three main criteria, namely service level, cycle time, and maximum tardy time. In solving this multiple-criteria decision-making problem, the proposed study seeks to redesign three process control factors, namely the service configuration, the dispatching rule, and the scheduling rule. The problem is solved using the Taguchi robust design methodology. Since the Taguchi method handles parameter design problems with only one criterion, Technique for Order Preference by Similarity to an Ideal Solution, a multiple-criteria decision-making method, is used to provide a surrogate response to the Taguchi method. The numerical results show that the redesigned IPI system improves the service level by 28.75%, the cycle time by 18.32%, and the maximum tardy time by 22.22%. Full article

(This article belongs to the Special Issue Smart Manufacturing and Sustainable Lean Management)

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26 pages, 4305 KiB

Open AccessArticle

Investigation on Human Development Needs, Challenges, and Drivers for Transition to Sustainable Development: The Case of Qatar

by Btool H. Mohamed, Mustafa Disli, Mohammed bin Saleh Al-Sada and Muammer Koç

Sustainability 2022, 14(6), 3705; https://doi.org/10.3390/su14063705 - 21 Mar 2022

Cited by 21 | Viewed by 7731

Abstract

Human development has been widely accepted as both the primary goal and driver of sustainable development. Human development is critically important for countries attempting a radical transformation from a resource-based economy to knowledge-based, sustainable development, like Qatar. This paper examines Qatar’s human development [...] Read more.

Human development has been widely accepted as both the primary goal and driver of sustainable development. Human development is critically important for countries attempting a radical transformation from a resource-based economy to knowledge-based, sustainable development, like Qatar. This paper examines Qatar’s human development needs and challenges with respect to its economic, demographic, and educational development goals. Following a comprehensive literature review, domain-specific documentary information and data were collected and analyzed, along with qualitative insights and data obtained through semi-structured interviews with local professionals from various sectors, to gather opinions about the needs, challenges, drivers, and recommendations for human development. A preliminary integrated policy framework and set of recommendations for human development planning are proposed as a guide, for Qatar and similar countries, for transitioning from a resource-based economy to knowledge-based sustainable development. This framework and the understanding of the needs, challenges, and drivers based on the qualitative research, in conjunction and in comparison with the literature analysis, are expected to assist decision-makers in devising, and more importantly implementing, tailored policies and roadmaps focused on four key dimensions: skills (education), citizenship, leadership, and health. Full article

(This article belongs to the Special Issue Sustainability on Education Policies)

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19 pages, 2605 KiB

Open AccessArticle

Production and Characterization of Polyhydroxyalkanoates from Wastewater via Mixed Microbial Cultures and Microalgae

by Simone Bagatella, Riccardo Ciapponi, Elena Ficara, Nicola Frison and Stefano Turri

Sustainability 2022, 14(6), 3704; https://doi.org/10.3390/su14063704 - 21 Mar 2022

Cited by 6 | Viewed by 4345

Abstract

In the context of circular economy and sustainable production of materials, this project investigated the feasibility of producing sustainable polyhydroxyalkanoates (PHA) from microalgae and sludge used in the treatment of municipal wastewater. The overall process was studied looking at the main steps: microalgae [...] Read more.

In the context of circular economy and sustainable production of materials, this project investigated the feasibility of producing sustainable polyhydroxyalkanoates (PHA) from microalgae and sludge used in the treatment of municipal wastewater. The overall process was studied looking at the main steps: microalgae production, fermentation of the biomass, production and characterization of the PHAs. It was possible to obtain blends of hydroxybutyrate-hydroxyvalerate copolymers with high molecular weights and different compositions depending on the nature of the feedstock (mixed volatile fatty acids). In some cases, almost completely amorphous PHA materials were obtained, suggesting a potential diversification of uses and applications. Full article

(This article belongs to the Special Issue Wastewater Treatment and Sustainability of Development)

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24 pages, 1058 KiB

Open AccessArticle

An Asymmetric Nexus: Remittance-Led Human Capital Development in the Top 10 Remittance-Receiving Countries: Are FDI and Gross Capital Formation Critical for a Road to Sustainability?

by Chengjuan Xia, Md. Qamruzzaman and Anass Hamadelneel Adow

Sustainability 2022, 14(6), 3703; https://doi.org/10.3390/su14063703 - 21 Mar 2022

Cited by 44 | Viewed by 3941

Abstract

As a growth input, human capital and remittances have received significant attention and their role on other macro fundamentals has also been investigated. However, the effects of remittances on human capital development are not yet conclusive in the literature. The motivation of the [...] Read more.

As a growth input, human capital and remittances have received significant attention and their role on other macro fundamentals has also been investigated. However, the effects of remittances on human capital development are not yet conclusive in the literature. The motivation of the study is to gauge the role of remittances in the process of human capital development in the topb10 remittance recipients for the period spanning from 1980 to 2019. The study has implemented symmetric and asymmetric estimations to explore the effects of remittances, FDI, and gross capital formation on human capital development. The study documented a positive and statistically significant linkage between remittances and human capital development; a similar linkage was revealed for FDI and gross capital formation. Asymmetric assessment detected asymmetric effects running from remittances, FDI, and gross capital formation to human capital development, both in the long-run and the short-run. Moreover, asymmetric shocks in remittances and FDI have exposed positive and statistically significant human capital development. In contrast, gross capital formation revealed a negative and statistically significant connection with human capital development. Referring to a directional causality test, the study documented a feedback hypothesis that holds in explaining the causality between remittances, FDI, and human capital development and unidirectional causality running from gross capital formation and human capital development. In regard to policy formulation, the study suggested that offering additional incentives could induce migrants to send more remittances into the economy, eventually supporting sustainable economic growth. Second, an efficient and effective financial sector can ensure optimal utilization through the channel of capital formation in the economy; therefore, countries must pay attention to the establishment of efficient intermediation. Full article

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21 pages, 9931 KiB

Open AccessArticle

Implementation of Construction Waste Recycling under Construction Sustainability Incentives: A Multi-Agent Stochastic Evolutionary Game Approach

by Ying Sun and Zhaolin Gu

Sustainability 2022, 14(6), 3702; https://doi.org/10.3390/su14063702 - 21 Mar 2022

Cited by 18 | Viewed by 2918

Abstract

Because of the rapid development of the economy and the process of urbanization, construction waste recycling is becoming increasingly important and should be considered. Motivated by effectively managing the construction waste recycling under sustainability incentives, the multi-agent stochastic game model is used to [...] Read more.

Because of the rapid development of the economy and the process of urbanization, construction waste recycling is becoming increasingly important and should be considered. Motivated by effectively managing the construction waste recycling under sustainability incentives, the multi-agent stochastic game model is used to evaluate the evolutionary behavior of the government agencies, waste recyclers, and waste producers. To capture the uncertainty existing in the external environment, the replicator dynamic formula is integrated with Gaussian noise, and the Lyapunov exponent diagram is analyzed to illustrate the nonlinear dynamic behavior. The numerical approximations are then solved by utilizing the random Taylor expansion formula. Finally, a numerical simulation is performed to evaluate the evolutionary trajectories of the participants involved. The findings revealed that: (1) the government agency should adopt a positive supervision approach, which can encourage waste producers and recyclers to collaborate around each other; (2) lower sorting and disposal costs can enhance construction waste recycling; and (3) the existence of uncertainty in the environment around different participants will influence one’s strategy selection. Full article

(This article belongs to the Topic Sustainability in Buildings: New Trends in the Management of Construction and Demolition Waste)

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20 pages, 2146 KiB

Open AccessArticle

Citizen Participation and Climate Change within an Urban Community Context: Insights for Policy Development for Bottom-Up Climate Action Engagement

by Mufaro Chitsa, Subarna Sivapalan, Balbir Singh Mahinder Singh and Khai Ern Lee

Sustainability 2022, 14(6), 3701; https://doi.org/10.3390/su14063701 - 21 Mar 2022

Cited by 11 | Viewed by 5226

Abstract

Citizen-led mitigation and adaptation are key to climate policy advancement and acceleration, particularly within an urban development context. The top-down approach requires the development of clear action plans for the involvement and engagement of citizens to accelerate bottom-up climate mitigation and adaptation efforts [...] Read more.

Citizen-led mitigation and adaptation are key to climate policy advancement and acceleration, particularly within an urban development context. The top-down approach requires the development of clear action plans for the involvement and engagement of citizens to accelerate bottom-up climate mitigation and adaptation efforts within the urban context. In Malaysia, there are national policy strategies such as the 12th Malaysia Plan, the National Urban Wellbeing Blueprint, the National Climate Change Policy, and the Malaysian New Urban Agenda. However, a successful implementation of climate policies can only be achieved when citizens are adequately socialized to policy impacts. This paper explores citizen perceptions and attitudes toward participation in mitigation and adaptation efforts for climate action within an urban context. Underpinned by the Theory of Planned Behavior and the Transtheoretical Theory, this study explored the approach of citizen participation as a possible tool for assessing climate policy effectiveness for bottom-up climate mitigation and adaptation efforts within an urban context. The study was set within the Malaysian urban context, given the limited empirical evidence in the area. The findings of the study suggest that a bottom-up approach to citizen participation through education, awareness, and inclusive climate policy formulation procedures will result in positive attitudes toward citizen participation. Full article

(This article belongs to the Special Issue Looking beyond Sustainability: Selected Papers from the 9th World Sustainability Forum (WSF 2021))

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14 pages, 12689 KiB

Open AccessArticle

Research on the Coordination between Agricultural Production and Environmental Protection in Kazakhstan Based on the Rationality of the Objective Weighting Method

by Danmeng Wang, Shilin Li, Shynggys Toktarbek, Nueryia Jiakula, Ping Ma and Yongzhong Feng

Sustainability 2022, 14(6), 3700; https://doi.org/10.3390/su14063700 - 21 Mar 2022

Cited by 9 | Viewed by 2459

Abstract

In the context of sustainable development, agricultural production and environmental protection are inseparable, and environmental quality directly affects regional agricultural production safety. Kazakhstan is the largest food producer and exporter in Central Asia, and the quality of its agricultural environment is of great [...] Read more.

In the context of sustainable development, agricultural production and environmental protection are inseparable, and environmental quality directly affects regional agricultural production safety. Kazakhstan is the largest food producer and exporter in Central Asia, and the quality of its agricultural environment is of great significance to international food security. This study focuses on the rationality of the entropy weight, factor weight, and CRITIC weight in the agricultural environmental evaluation within the common objective weight method, and comprehensively evaluates the coordination of environmental protection and agricultural production in Kazakhstan. The results show that (1) CRITIC weights are the most stable, followed by factor weights, while entropy weighting is the most unstable; objective weighting methods have their limitations and must be related to actual conditions and subjective experience. (2) The level of environmental protection and the degree of coordination are most problematic near the Aral Sea, followed by the remaining western region; the results reveal that these evaluation indexs are also insufficient at Kostany and Karagandy in the central region; this is caused by historical issues, climate change, natural conditions, and agricultural management patterns. Investment in environmental protection and agricultural production management should be coordinated in a targeted manner. (3) Except for the areas near the Aral Sea, the level of agricultural production in other states is very promising. This research serves as a reference for environmental assessment research, environmental governance investment, and agricultural production management in Kazakhstan. Full article

(This article belongs to the Section Sustainable Agriculture)

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12 pages, 1314 KiB

Open AccessEditor’s ChoiceArticle

Implementing Artificial Intelligence Techniques to Predict Environmental Impacts: Case of Construction Products

by Anish Koyamparambath, Naeem Adibi, Carolina Szablewski, Sierra A. Adibi and Guido Sonnemann

Sustainability 2022, 14(6), 3699; https://doi.org/10.3390/su14063699 - 21 Mar 2022

Cited by 18 | Viewed by 8697

Abstract

Nowadays, product designers, manufacturers, and consumers consider the environmental impacts of products, processes, and services in their decision-making process. Life Cycle Assessment (LCA) is a tool that assesses the environmental impacts over a product’s life cycle. Conducting a life cycle assessment (LCA) requires [...] Read more.

Nowadays, product designers, manufacturers, and consumers consider the environmental impacts of products, processes, and services in their decision-making process. Life Cycle Assessment (LCA) is a tool that assesses the environmental impacts over a product’s life cycle. Conducting a life cycle assessment (LCA) requires meticulous data sourcing and collection and is often time-consuming for both practitioner and verifier. However, predicting the environmental impacts of products and services can help stakeholders and decision-makers identify the hotspots. Our work proposes using Artificial Intelligence (AI) techniques to predict the environmental performance of a product or service to assist LCA practitioners and verifiers. This approach uses data from environmental product declarations of construction products. The data is processed utilizing natural language processing (NLP) which is then trained to random forest algorithm, an ensemble tree-based machine learning method. Finally, we trained the model with information on the product and their environmental impacts using seven impact category values and verified the results using a testing dataset (20% of EPD data). Our results demonstrate that the model was able to predict the values of impact categories: global warming potential, abiotic depletion potential for fossil resources, acidification potential, and photochemical ozone creation potential with an accuracy (measured using R² metrics, a measure to score the correlation of predicted values to real value) of 81%, 77%, 68%, and 70%, respectively. Our method demonstrates the capability to predict environmental performance with a defined variability by learning from the results of the previous LCA studies. The model’s performance also depends on the amount of data available for training. However, this approach does not replace a detailed LCA but is rather a quick prediction and assistance to LCA practitioners and verifiers in realizing an LCA. Full article

(This article belongs to the Special Issue Life Cycle Thinking and Sustainability Assessment of Buildings)

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20 pages, 1604 KiB

Open AccessArticle

Streetcar Development in China: The Motivations Behind

by Meng An and Xuewu Chen

Sustainability 2022, 14(6), 3698; https://doi.org/10.3390/su14063698 - 21 Mar 2022

Cited by 1 | Viewed by 3143

Abstract

In recent years, there has been a remarkable rebirth of the streetcar in China, with dozens of projects under consideration, in planning and construction, or already completed in cities throughout the country. The development of such a relatively mega-project often raises the question [...] Read more.

In recent years, there has been a remarkable rebirth of the streetcar in China, with dozens of projects under consideration, in planning and construction, or already completed in cities throughout the country. The development of such a relatively mega-project often raises the question of “why Chinese cities develop their streetcar projects”. Building on insights into streetcar projects materials and in-depth interviews with elite figures, and together with relevant socioeconomic data comparisons, the paper sets out to reveal how the resurgence of the streetcar was facilitated and motivated, and why such urban mega-projects are so attractive to cities, and to further derive lessons to better inform policymakers, planners, and researchers in proposing, planning and implementing streetcars in China. Our findings revealed five major themes to motivate streetcars development in China, which unpacked the answer to the question into five aspects: rapid urbanization, supportive policy environment, less-restrictive approval mechanisms, goal-seeking for streetcar development, and potential inter-city competition. A discussion of these themes in the Chinese context leads us to the conclusion that the process of proposing, promoting, and approving streetcar projects is not only dependent on its expected achievements bring to the region but very much on the economic–political reasons and inter-city competition. Full article

(This article belongs to the Section Sustainable Transportation)

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29 pages, 3183 KiB

Open AccessArticle

Analysis of SPI as a Drought Indicator during the Maize Growing Period in the Çukurova Region (Turkey)

by Roman Rolbiecki, Ali Yücel, Joanna Kocięcka, Atılgan Atilgan, Monika Marković and Daniel Liberacki

Sustainability 2022, 14(6), 3697; https://doi.org/10.3390/su14063697 - 21 Mar 2022

Cited by 23 | Viewed by 3945

Abstract

One of the major challenges for agriculture related to climate change is drought. The increasing temperatures and decreasing precipitation in many parts of the world have enhanced the frequency and severity of drought events. Therefore, a detailed analysis is required in order to [...] Read more.

One of the major challenges for agriculture related to climate change is drought. The increasing temperatures and decreasing precipitation in many parts of the world have enhanced the frequency and severity of drought events. Therefore, a detailed analysis is required in order to determine the drought frequency and take the necessary precautions. In this study, the climatic conditions in the agricultural region of Çukurova (Turkey) were analysed. Meteorological data for the three provinces of Adana, Mersin, and Osmaniye were used. The aim was to calculate the Standardized Precipitation Index (SPI) for each of the three provinces analysed, and to use these values to detect drought during the different growth periods of maize. We also investigated whether the SPI values for the last 30 years differ significantly between the provinces. Furthermore, indicators such as the duration, magnitude, severity, recurrence, and drought frequency were also calculated. Using linear regression analysis, we determined whether there were trends in the multi-year data for the total precipitation and mean temperature. In addition, the water deficiency was determined by examining the amount of water required by maize and the adequacy of the precipitation in each development period. As a result, it was found that the Çukurova region is prone to droughts, but they follow a mild course in most cases. However, no statistically significant differences were observed between the SPI values in the three provinces. The calculated average approximate drought recurrences (Tr) and expected intensities (Iave) were Tr ~ 1.036 years and Iave ~ 5.634 mm year⁻¹ in 3 years for Adana, Tr ~ 1.031 years and Iave ~ −0.312 mm year⁻¹ in 3 years for Mersin, and Tr ~ 1.052 years and Iave ~ −0.084 mm year⁻¹ in 3 years Osmaniye. The research carried out in this paper confirmed that maize cultivation in the Çukurova region is vulnerable to drought, and adaptation actions should be taken immediately. Full article

(This article belongs to the Special Issue Environmental Engineering and Water Resources Management)

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15 pages, 556 KiB

Open AccessArticle

Influencing Factors of the Continuous Use of a Knowledge Payment Platform—Fuzzy-Set Qualitative Comparative Analysis Based on Triadic Reciprocal Determinism

by Hong Huo and Quanxi Li

Sustainability 2022, 14(6), 3696; https://doi.org/10.3390/su14063696 - 21 Mar 2022

Cited by 14 | Viewed by 3741

Abstract

Based on triadic reciprocal determinism, in this study, we adopted the fuzzy-set qualitative comparative analysis (fsQCA) method to conduct configuration analysis on the factors that influence the continuous use of knowledge payment platforms and explain the mechanism of the configuration effect of different [...] Read more.

Based on triadic reciprocal determinism, in this study, we adopted the fuzzy-set qualitative comparative analysis (fsQCA) method to conduct configuration analysis on the factors that influence the continuous use of knowledge payment platforms and explain the mechanism of the configuration effect of different influencing factors. The research included six casual variables: perceived value, platform quality, satisfaction, trust, subjective norms, and habits. Continuous use intention and continuous use behavior were used as the outcome variables. By discussing the action paths of six casual variables on two outcome variables, it is suggested that the operators of knowledge payment platforms should select different influencing factor configuration paths to improve the service and promote the continuous use of the knowledge payment platform by users. Full article

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15 pages, 8593 KiB

Open AccessArticle

A 3D-FE Model for the Rutting Prediction in Geogrid Reinforced Flexible Pavements

by Giovanni Leonardi and Federica Suraci

Sustainability 2022, 14(6), 3695; https://doi.org/10.3390/su14063695 - 21 Mar 2022

Cited by 13 | Viewed by 2962

Abstract

Permanent deformation (rutting) is an important disturbing failure on flexible road pavements. This phenomenon appears on the flexible pavement as longitudinal depressions, and it is a consequence of the degradation of materials under high traffic loading based on consolidation/densification, surface wear, plastic/shear flow, [...] Read more.

Permanent deformation (rutting) is an important disturbing failure on flexible road pavements. This phenomenon appears on the flexible pavement as longitudinal depressions, and it is a consequence of the degradation of materials under high traffic loading based on consolidation/densification, surface wear, plastic/shear flow, and mechanical deformation. Hence, the rutting phenomenon depends on the accumulation of permanent deformations on pavement surfaces subjected to repeated wheel loads. In recent years, several studies have confirmed that the service life of asphalt pavements can be increased by using geosynthetics between or within layers because of the improved mechanical properties. The aim of this paper is to present the results of the 3D-finite element (FE) simulations and the development of the rutting phenomenon in a traditional flexible pavement and a reinforced one, both subjected to a cyclic load. Through Abaqus/CAE software, a road section reinforced by a geogrid was analyzed and compared with a traditional road section to investigate the advantages given by the geosynthetic completely embedded at two-thirds of the asphalt concrete layer (AC) in terms of permanent deformations. The results show the capability of the proposed FE study, that uses the plasticity model of Drucker-Prager for unbound materials combined with the simple creep law to model HMA layers to predict the permanent deformation distribution. Full article

(This article belongs to the Collection Reviews, Advances and Applications in Environmental Sustainability)

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26 pages, 7003 KiB

Open AccessArticle

Government Intervention, Human Mobility, and COVID-19: A Causal Pathway Analysis from 121 Countries

by Feng Wang, Xing Ge and Danwen Huang

Sustainability 2022, 14(6), 3694; https://doi.org/10.3390/su14063694 - 21 Mar 2022

Cited by 8 | Viewed by 2444

Abstract

Based on data from 121 countries, the study assesses the dynamic effect and causality path of the government epidemic prevention policies and human mobility behaviors on the growth rates of COVID-19 new cases and deaths. Our results find that both policies and behaviors [...] Read more.

Based on data from 121 countries, the study assesses the dynamic effect and causality path of the government epidemic prevention policies and human mobility behaviors on the growth rates of COVID-19 new cases and deaths. Our results find that both policies and behaviors influenced COVID-19 cases and deaths. The direct effect of policies on COVID-19 was more than the indirect effect. Policies influence behaviors, and behaviors react spontaneously to information. Further, masks give people a false sense of security and increase mobility. The close public transport policy increased COVID-19 new cases. We also conducted sensitivity analysis and found that some policies hold robustly, such as the policies of school closing, restrictions on gatherings, stay-at-home requirements, international travel controls, facial coverings, and vaccination. The counterfactual tests suggest that, as of early March 2021, if governments had mandated masking policies early in the epidemic, the cases and deaths would have been reduced by 18% and 14% separately. If governments had implemented vaccination policies early in the pandemic, the cases and deaths would have been reduced by 93% and 62%, respectively. Without public transportation closures, cases and deaths would have been reduced by 40% and 10%, respectively. Full article

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14 pages, 880 KiB

Open AccessArticle

The Influence of Social Networks on the Digital Recruitment of Human Resources: An Empirical Study in the Tourism Sector

by Ionica Oncioiu, Emanuela Anton, Ana Maria Ifrim and Diana Andreea Mândricel

Sustainability 2022, 14(6), 3693; https://doi.org/10.3390/su14063693 - 21 Mar 2022

Cited by 15 | Viewed by 7957

Abstract

The global employment landscape will continue to change due to new technologies, in particular automation, online collaboration tools, and artificial intelligence. The shortage of skilled workers and the growing jobs of e-tourism employees are a challenge for maintaining day-to-day operations. It is crucial [...] Read more.

The global employment landscape will continue to change due to new technologies, in particular automation, online collaboration tools, and artificial intelligence. The shortage of skilled workers and the growing jobs of e-tourism employees are a challenge for maintaining day-to-day operations. It is crucial to develop a digital recruitment strategy and communicate a good employer brand, supported by targeted digital advertising. This study aims to identify the impact of social networks on the effectiveness of digital human resources recruitment strategies in tourism. On the basis of a sample of 620 respondents who had experience of the digital recruitment of human resources in the tourism sector, the collected data was analyzed using structural equation modeling. The results underline the high relevance of building these strategies, as professional communication in social networks is the key to successful work in sustainable human resources practices. Full article

(This article belongs to the Special Issue Sustainability in People Management)

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22 pages, 3338 KiB

Open AccessArticle

Adaptive DMA Design and Operation under Multiscenarios in Water Distribution Networks

by Xuan Khoa Bui, Gimoon Jeong and Doosun Kang

Sustainability 2022, 14(6), 3692; https://doi.org/10.3390/su14063692 - 21 Mar 2022

Cited by 11 | Viewed by 2794

Abstract

Water distribution network (WDN) is a human-centered infrastructure that is indispensable for modern cities worldwide. In addition to optimizing the operation and management (O&M) of WDNs under the current state, water utilities should be able to manage uncertain and risk conditions for improving [...] Read more.

Water distribution network (WDN) is a human-centered infrastructure that is indispensable for modern cities worldwide. In addition to optimizing the operation and management (O&M) of WDNs under the current state, water utilities should be able to manage uncertain and risk conditions for improving their O&M efficiency. Although the disintegration of large WDNs into permanent district metered areas (DMAs) is an O&M innovation based on water leakage monitoring and pressure management, its network redundancy and reliability diminish under anomalous conditions. Therefore, this study proposed a design and operation procedure to obtain optimal, self-adaptive DMA configurations for various plausible abnormal scenarios. The proposed method is based on multiscenario simulation and optimization, comprising two phases: (1) design of optimal DMA layout for each scenario using the pressure uniformity index to optimize the placement of flow meters and gate valves, and (2) dynamic transformation of the base DMA configuration into an adaptive DMA layout adapting to abnormal conditions and optimization of the locations and statuses of the control valves. Moreover, we used a real-world WDN to demonstrate the effectiveness of the proposed approach, and the obtained results revealed the efficiency and appropriate performance of the adaptive DMA layouts for sustainable adaptation of WDNs under anomalous conditions. Full article

(This article belongs to the Special Issue Safety in the Operation of Water Supply Systems)

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14 pages, 758 KiB

Open AccessArticle

The Emergence of Unconventional Tourism Services Based on Autonomous Vehicles (AVs)—Attitude Analysis of Tourism Experts Using the Q Methodology

by Katalin Ásványi, Márk Miskolczi, Melinda Jászberényi, Zsófia Kenesei and László Kökény

Sustainability 2022, 14(6), 3691; https://doi.org/10.3390/su14063691 - 21 Mar 2022

Cited by 6 | Viewed by 2677

Abstract

The spread of autonomous vehicles (AVs) could fundamentally change tourism-related mobility in the near future. However, the empirical research on tourism impacts is still very limited. This research aims to systematize the expected tourism impacts of AVs and to explore how experts in [...] Read more.

The spread of autonomous vehicles (AVs) could fundamentally change tourism-related mobility in the near future. However, the empirical research on tourism impacts is still very limited. This research aims to systematize the expected tourism impacts of AVs and to explore how experts in different fields of tourism view the technological innovation ahead. The opinions of tourism experts (n = 21) involved in the research were analyzed using the Q methodology. Statements (n = 40) were formulated in topics derived from the literature. Based on the analysis, we distinguished four groups of opinions. An optimistic, technology-oriented group of experts suggested that AV-based sightseeing may emerge as a prominent unconventional service. An accessibility-focused group of experts predicting slow progress stressed that the spread of AVs could improve access to infrastructurally advanced destinations. A mobility-service-oriented group considered that the use of AVs is becoming conventional in terms of mobility, but its appearance remains unconventional for other tourism services. Due to the potential negative effects, a skeptical group of experts believes that AVs will not become conventional in tourism. The value of the research is the creation of groups based on tourism experts’ attitudes, which can help prepare strategic tourism decisions in the future. Full article

(This article belongs to the Special Issue A Geography of Unconventional Tourist Mobility: New Approaches and Methodologies)

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19 pages, 625 KiB

Open AccessArticle

Sustainable Adoption of E-Learning from the TAM Perspective

by Saman Sattar Saleh, Muesser Nat and Musbah Aqel

Sustainability 2022, 14(6), 3690; https://doi.org/10.3390/su14063690 - 21 Mar 2022

Cited by 15 | Viewed by 6173

Abstract

This study investigates the imperative to adopt e-learning and how it influences educational process sustainability. For developing countries, adopting e-learning has always been a challenge because of the lack of mechanisms due to the resistance of teachers and students, low level of information [...] Read more.

This study investigates the imperative to adopt e-learning and how it influences educational process sustainability. For developing countries, adopting e-learning has always been a challenge because of the lack of mechanisms due to the resistance of teachers and students, low level of information and communication technology (ICT) literacy, and lack of ICT infrastructure. A quantitative research methodology was used by applying a hypothesized extended model of the technology acceptance model (TAM) for the adoption of e-learning. The factors were investigated by analyzing the intentions of 367 students and teachers. Data were collected through an online questionnaire. This study aims to identify the factors that influence students’ and teachers’ attitudes toward the adoption of sustainable e-learning and illustrate the moderating role of the mentality acceptance factor in the relationship between system trust and interaction, on the one hand, and PU and PEOU on the other. Findings of the study indicated that all TAM constructs significantly impact the BI of e-learning use. Additionally, the results showed that mentality acceptance substantially moderates the relationship between system trust and interaction, on the one hand, and PU and PEOU on the other. These findings suggest that educational institutions should focus on factors influencing teachers’ and students’ attitudes toward adopting and using e-learning services. Lack of internet connection, ICT skills, and technology capabilities are the main issues, and the main TAM constructs of all factors. Full article

(This article belongs to the Topic Advances in Online and Distance Learning)

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24 pages, 8746 KiB

Open AccessArticle

Machine Learning-Based Intelligent Prediction of Elastic Modulus of Rocks at Thar Coalfield

by Niaz Muhammad Shahani, Xigui Zheng, Xiaowei Guo and Xin Wei

Sustainability 2022, 14(6), 3689; https://doi.org/10.3390/su14063689 - 21 Mar 2022

Cited by 25 | Viewed by 3187

Abstract

Elastic modulus (E) is a key parameter in predicting the ability of a material to withstand pressure and plays a critical role in the design of rock engineering projects. E has broad applications in the stability of structures in mining, petroleum, geotechnical engineering, [...] Read more.

Elastic modulus (E) is a key parameter in predicting the ability of a material to withstand pressure and plays a critical role in the design of rock engineering projects. E has broad applications in the stability of structures in mining, petroleum, geotechnical engineering, etc. E can be determined directly by conducting laboratory tests, which are time consuming, and require high-quality core samples and costly modern instruments. Thus, devising an indirect estimation method of E has promising prospects. In this study, six novel machine learning (ML)-based intelligent regression models, namely, light gradient boosting machine (LightGBM), support vector machine (SVM), Catboost, gradient boosted tree regressor (GBRT), random forest (RF), and extreme gradient boosting (XGBoost), were developed to predict the impacts of four input parameters, namely, wet density (ρ_wet) in gm/cm³, moisture (%), dry density (ρ_d) in gm/cm³, and Brazilian tensile strength (BTS) in MPa on output E (GPa). The associated strengths of every input and output were systematically measured employing a series of fundamental statistical investigation tools to categorize the most dominant and important input parameters. The actual dataset of E was split as 70% for the training and 30% for the testing for each model. In order to enhance the performance of each developed model, an iterative 5-fold cross-validation method was used. Therefore, based on the results of the study, the XGBoost model outperformed the other developed models with a higher accuracy, coefficient of determination (R² = 0.999), mean absolute error (MAE = 0.0015), mean square error (MSE = 0.0008), root mean square error (RMSE = 0.0089), and a20-index = 0.996 of the test data. In addition, GBRT and RF have also shown high accuracy in predicting E with R² values of 0.988 and 0.989, respectively, but they can be used conditionally. Based on sensitivity analysis, all parameters were positively correlated, while BTS was the most influential parameter in predicting E. Using an ML-based intelligent approach, this study was able to provide alternative elucidations for predicting E with appropriate accuracy and run time at Thar coalfield, Pakistan. Full article

(This article belongs to the Special Issue Advances in Rock Mechanics and Geotechnical Engineering)

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28 pages, 13332 KiB

Open AccessArticle

Study on the Extraction Method of Sub-Network for Optimal Operation of Connected and Automated Vehicle-Based Mobility Service and Its Implication

by Sehyun Tak, Jeongyun Kim and Donghoun Lee

Sustainability 2022, 14(6), 3688; https://doi.org/10.3390/su14063688 - 21 Mar 2022

Cited by 3 | Viewed by 2023

Abstract

There have been enormous efforts to implement automated vehicle-based mobility (AVM) by considering smart infrastructure such as cooperative intelligent transportation system. However, there is lack of consideration on economical approach for an optimal deployment strategy of the AVM service and smart infrastructure. Furthermore, [...] Read more.

There have been enormous efforts to implement automated vehicle-based mobility (AVM) by considering smart infrastructure such as cooperative intelligent transportation system. However, there is lack of consideration on economical approach for an optimal deployment strategy of the AVM service and smart infrastructure. Furthermore, the influence of travel demand in service area has been ignored. We develop a new framework for maximizing the profit of connected and automated vehicle-based mobility (CAV-M) service using cost modeling and metaheuristic optimization algorithm. The proposed framework extracts an optimal sub-network, which is selected by a set of optimal links in the service area, and identifies an optimal construction strategy for the smart infrastructure depending on given operational design domain and travel demand. Based on service network analyses with varying demand patterns and volumes, we observe that the optimal sub-network varies with the combination of trip demand patterns and volumes. It is also found that the benefit of deploying the smart infrastructure is obtainable only when there are sufficient travel demands. Furthermore, the optimal sub-network is always superior to raw network in terms of economical profit, which suggests the proposed framework has great potential to prioritize road links in the target area for the CAV-M service. Full article

(This article belongs to the Special Issue Towards Sustainability: Data-Driven Design of Intelligent Transportation Systems)

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14 pages, 309 KiB

Open AccessArticle

Exploring the Intersection Where Business Models, a Circular Economy and Sustainability Meet in the Waste Economy: A Scoping Review

by Marlin Hoffman, Catherina J. Schenck and Frederick Herbst

Sustainability 2022, 14(6), 3687; https://doi.org/10.3390/su14063687 - 21 Mar 2022

Cited by 5 | Viewed by 4888

Abstract

The authors endeavor to investigate the intersection and relationship between sustainability, business models and a circular economy. These three concepts are believed to be at the heart of finding a solution to creating and implementing a circular economy. The three pillars of sustainability [...] Read more.

The authors endeavor to investigate the intersection and relationship between sustainability, business models and a circular economy. These three concepts are believed to be at the heart of finding a solution to creating and implementing a circular economy. The three pillars of sustainability (society, environment and economics) have been identified as the golden thread when applied to developing circular economies and the business models used in these circular economies. These three pillars highlighted the areas of intersection and engagement between the circular economy and business models. The three pillars, or stakeholders, need to be considered equally and, where there is sacrifice and benefits, they need to be balanced. A scoping review was chosen, as the starting point, to ascertain the literature in the field. The results of the scoping review showed a lack of research conducted at the point of intersection between these three fields. Finding a solution by creating and implementing a circular economy will have positive effects on the economy, environment and society, as there is, proverbially, “not much time left” and everyone in the process will sacrifice and benefit. The research has highlighted the need to explore the intersection and relationship between sustainability, business models and the circular economy as a concept, and future research should develop frameworks to guide the development and implementation of this intersection to include all relevant stakeholders. Full article

(This article belongs to the Special Issue Circular Economy: Waste Management and Producer Responsibility)

23 pages, 5645 KiB

Open AccessArticle

Energy, Exergy, and Economic Analysis of Cryogenic Distillation and Chemical Scrubbing for Biogas Upgrading and Hydrogen Production

by Esfandiyar Naeiji, Alireza Noorpoor and Hossein Ghanavati

Sustainability 2022, 14(6), 3686; https://doi.org/10.3390/su14063686 - 21 Mar 2022

Cited by 10 | Viewed by 4357

Abstract

Biogas is one of the most important sources of renewable energy and hydrogen production, which needs upgrading to be functional. In this study, two methods of biogas upgrading from organic parts of municipal waste were investigated. For biogas upgrading, this article used a [...] Read more.

Biogas is one of the most important sources of renewable energy and hydrogen production, which needs upgrading to be functional. In this study, two methods of biogas upgrading from organic parts of municipal waste were investigated. For biogas upgrading, this article used a 3E analysis and simulated cryogenic separation and chemical scrubbing. The primary goal was to compare thermoeconomic indices and create hydrogen by reforming biomethane. The exergy analysis revealed that the compressor of the refrigerant and recovery column of MEA contributed the most exergy loss in the cryogenic separation and chemical scrubbing. The total exergy efficiency of cryogenic separation and chemical scrubbing was 85% and 84%. The energy analysis revealed a 2.07% lower energy efficiency for chemical scrubbing. The capital, energy, and total annual costs of chemical absorption were 56.51, 26.33, and 54.44 percent lower than those of cryogenic separation, respectively, indicating that this technology is more economically feasible. Moreover, because the thermodynamic efficiencies of the two methods were comparable, the chemical absorption method was adopted for hydrogen production. The biomethane steam reforming was simulated, and the results indicated that this method required an energy consumption of 90.48

\frac{MJ}{{kg}_{H_{2}}}

. The hydrogen production intensity equaled 1.98

\frac{{kmole}_{H_{2}}}{{kmole}_{biogas}}

via a 79.92% methane conversion. Full article

(This article belongs to the Special Issue Environmental Effects Assessment of Clean Energy Technologies and Sustainable Development)

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15 pages, 1324 KiB

Open AccessArticle

Spatiotemporal Evolution of the Environmental Adaptability Efficiency of the Agricultural System in China

by Xianglong Tang, Chenyu Lu, Peng Meng and Wei Cheng

Sustainability 2022, 14(6), 3685; https://doi.org/10.3390/su14063685 - 21 Mar 2022

Cited by 8 | Viewed by 2352

Abstract

Since its emergence, the development of agriculture has always been closely related to changes in the natural environment. The productivity and development of agriculture largely depend on natural conditions and agriculture and has an important impact on the environment. The development of modern [...] Read more.

Since its emergence, the development of agriculture has always been closely related to changes in the natural environment. The productivity and development of agriculture largely depend on natural conditions and agriculture and has an important impact on the environment. The development of modern conventional agriculture has also led to a series of ecological, economic, and social problems that threaten human development and sustenance. China has historically been heavily reliant on agriculture and provides food and clothing for approximately 22% of the world’s population while only accounting for 9% of the world’s cultivated land and 6% of freshwater resources. Since the 21st century, the agricultural development of China has faced increasing resource and environmental constraints due to rapid industrialization and urbanization. Based on the perspective of efficiency evolution, data envelopment analysis (DEA) and spatial autocorrelation analysis (SAA) were used to test the environment adaptability efficiency within China’s agricultural systems across 30 provinces, autonomous regions, and municipalities, and explore its temporal and spatial evolution patterns and characteristics. Our study thus possesses both theoretical and practical significance. Furthermore, this study would enable the development of methods to assess China’s agricultural systems, in addition to providing a theoretical basis and guidelines for the creation of sustainable agriculture development strategies both in China and in other countries and regions. The following are the main conclusions of this study: (1) from 2000 to 2018, the overall environmental adaptability efficiency within China’s agricultural systems exhibited a gradual upward trend, achieving a transition from medium-level efficiency towards high-level efficiency, and the environmental adaptability of agricultural systems continued to increase. However, a certain gap remained between the level achieved and the DEA’s level of effectiveness, and therefore additional efforts are required to close this gap. (2) The environmental adaptability efficiency within China’s agricultural system showed a significant positive correlation in spatial distribution. Particularly, clear spatial aggregation characteristics were observed at the provincial level, which was also characterized by strong features of spatial dependence and spatial heterogeneity. Moreover, the degree of spatial aggregation increased gradually over time. High-value areas were mainly located along the southeast coastal area, whereas low-value areas were primarily located in the inland areas of the northwest. Therefore, environmental adaptability efficiency generally followed a northwest-southeast spatial distribution. Full article

(This article belongs to the Collection Sustainability in Agricultural Systems and Ecosystem Services)

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12 pages, 831 KiB

Open AccessArticle

Effect of Nitrogen Fertilizer and Biochar on Organic Matter Mineralization and Carbon Accretion in Soil

by Momtahina Hasnat, Mohammad Ashraful Alam, Mariam Khanam, Bushra Islam Binte, Mohammad Humayun Kabir, Mohammad Saiful Alam, Mohammed Zia Uddin Kamal, Golum Kibria Muhammad Mustafizur Rahman, Mohammad Manjurul Haque and Mohammad Mizanur Rahman

Sustainability 2022, 14(6), 3684; https://doi.org/10.3390/su14063684 - 21 Mar 2022

Cited by 10 | Viewed by 3191

Abstract

Soil carbon (C) mineralization was studied in an incubation experiment comprised of two factors having six organic materials and three nitrogen (N) rates. Cow dung (CD), rice straw (RS), wood ash (WA), cow dung biochar (CB), rice straw biochar (RB) and wood biochar [...] Read more.

Soil carbon (C) mineralization was studied in an incubation experiment comprised of two factors having six organic materials and three nitrogen (N) rates. Cow dung (CD), rice straw (RS), wood ash (WA), cow dung biochar (CB), rice straw biochar (RB) and wood biochar (WB) considering 2.5 g C kg⁻¹ soil along with three levels of N, i.e., 0, 0.05 and 0.10 g N kg⁻¹ soil were mixed with 400 g of soil used in each pot. The pots were placed for 0, 30, 60, 90, 120, 150 and 180 days of incubation, and soils were collected after each incubation and analyzed for C and N. Irrespective of treatment factors, C decreased in an irregular fashion until 180 days of incubation. From the initial level of 1.91%, C contents decreased to 1.08, 1.10, 1.06, 1.23, 1.17 and 1.12% in soil mixed with CD, RS, WA, CB, RB and WB, respectively, and to 1.28, 1.11 and 0.99% in 0, 0.05 and 0.10 g N kg⁻¹ soil, respectively, at 180 days of incubation. The mineralization followed the order of WA > CD > RS > WB > RB > CB. Biochars could supply stable C in soil, while N enhances mineralization; optimization of N is therefore essential to ensure soil C accretion. Full article

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26 pages, 3004 KiB

Open AccessArticle

Learning from the Past: Pandemics and the Governance Treadmill

by D. G. Webster, Semra A. Aytur, Mark Axelrod, Robyn S. Wilson, Joseph A. Hamm, Linda Sayed, Amber L. Pearson, Pedro Henrique C. Torres, Alero Akporiaye and Oran Young

Sustainability 2022, 14(6), 3683; https://doi.org/10.3390/su14063683 - 21 Mar 2022

Cited by 3 | Viewed by 3891

Abstract

Global human health threats, such as the ongoing COVID-19 pandemic, necessitate coordinated responses at multiple levels. Public health professionals and other experts broadly agree about actions needed to address such threats, but implementation of this advice is stymied by systemic factors such as [...] Read more.

Global human health threats, such as the ongoing COVID-19 pandemic, necessitate coordinated responses at multiple levels. Public health professionals and other experts broadly agree about actions needed to address such threats, but implementation of this advice is stymied by systemic factors such as prejudice, resource deficits, and high inequality. In these cases, crises like epidemics may be viewed as opportunities to spark structural changes that will improve future prevention efforts. However, crises can also weaken governance and reinforce systemic failures. In this paper, we use the concept of the governance treadmill to demonstrate cross-level dynamics that help or hinder the alignment of capacities toward prevention during public health crises. We find that variation in capacities and responses across local, national, and international levels contributes to the complex evolution of global and local health governance. Where capacities are misaligned, effective local prevention of global pandemic impacts tends to be elusive in the short term, and multiple cycles of crisis and response may be required before capacities align toward healthy governance. We demonstrate that this transition requires broader societal adaptation, particularly towards social justice and participatory democracy. Full article

(This article belongs to the Special Issue Role for the Public Health System in Creating Sustainable Communities)

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23 pages, 2137 KiB

Open AccessArticle

Factors Influencing Returning Migrants’ Entrepreneurship Intentions for Rural E-Commerce: An Empirical Investigation in China

by Lijuan Huang, Yi Huang, Raoyi Huang, Guojie Xie and Weiwei Cai

Sustainability 2022, 14(6), 3682; https://doi.org/10.3390/su14063682 - 21 Mar 2022

Cited by 34 | Viewed by 6801

Abstract

Many Internet users have provided a favorable atmosphere for rural e-commerce to thrive, and the return of rural inhabitants starting their own companies has had a significant impact on rural economic development. Understanding the influencing elements for returning residents to carry out rural [...] Read more.

Many Internet users have provided a favorable atmosphere for rural e-commerce to thrive, and the return of rural inhabitants starting their own companies has had a significant impact on rural economic development. Understanding the influencing elements for returning residents to carry out rural e-commerce operations can provide suggestions for the ongoing development of the economy in rural regions and the lack of talent faced in rural areas, especially in light of the trend of people returning to their hometowns. This work offers a research model based on the push–pull–mooring (PPM) theory to explain the factors that drive returning residents to engage in rural e-commerce entrepreneurship. The empirical results determined using the PLS-SEM method and SmartPLS 3.0 software to analyze the survey data of 151 returning residents revealed that urban employment obstacles, policy support, and infrastructure are positively connected with returning residents carrying out rural e-commerce entrepreneurship. Start-up costs are negatively correlated with rural e-commerce entrepreneurship by returning residents. Policy support plays an intermediary role in the price of starting a business and in the return of rural residents starting a rural e-commerce business. We recommend that the government strengthens policy support for returning entrepreneurs, improves rural e-commerce infrastructure, assists entrepreneurs in lowering their start-up costs, and initiates activities aimed at enhancing entrepreneurial intentions and sustaining entrepreneurial activities, based on the findings of this study. Full article

(This article belongs to the Section Economic and Business Aspects of Sustainability)

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45 pages, 16011 KiB

Open AccessArticle

Investigation of Small-Scale Photovoltaic Systems for Optimum Performance under Partial Shading Conditions

by Mahmoud A. M. Youssef, Abdelrahman M. Mohamed, Yaser A. Khalaf and Yehia S. Mohamed

Sustainability 2022, 14(6), 3681; https://doi.org/10.3390/su14063681 - 21 Mar 2022

Cited by 1 | Viewed by 2390

Abstract

Not only are small photovoltaic (PV) systems widely used in poor countries and rural areas where the electrical loads are low but they can also be integrated into the national electricity grid to save electricity costs and reduce CO₂ emissions. Partial shading [...] Read more.

Not only are small photovoltaic (PV) systems widely used in poor countries and rural areas where the electrical loads are low but they can also be integrated into the national electricity grid to save electricity costs and reduce CO₂ emissions. Partial shading (PS) is one of the phenomena that leads to a sharp decrease in the performance of PV systems. This study provides a comprehensive performance investigation of small systems (consisting of ten modules or fewer) under all possible shading patterns that result from one shading level (300 W/m² is chosen). The most common configurations are considered for which a performance comparison is presented. Five small systems of different sizes are studied under PS. A new simplifying method is proposed to identify the distinct PS patterns under study. Consequently, the number of cases to be studied is significantly reduced from 1862 to 100 cases only. The study is conducted using the MATLAB/Simulink^® environment. The simulation results demonstrate the most outperformed configuration in each case of PS pattern and the amount of improvement for each configuration. The configurations include static series-parallel (SP), static total-cross-tied (TCT), dynamic switching between SP and TCT, and TCT-reconfiguration. The study provides PV systems’ owners with a set of guidelines to opt for the best configuration of their PV systems. The optimum recommended configuration is TCT reconfiguration, rather than dynamic switching between SP and TCT. The less recommended option, which enjoys simplicity but is still viable, is the static TCT. It outperforms the static SP in most cases of PS patterns. Full article

(This article belongs to the Special Issue Technology Innovation and Applications of Power Electronics of Renewable Energy Systems)

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27 pages, 6235 KiB

Open AccessArticle

Fuzzy AHP-Based Design Performance Index for Evaluation of Ferries

by Harsha Cheemakurthy and Karl Garme

Sustainability 2022, 14(6), 3680; https://doi.org/10.3390/su14063680 - 21 Mar 2022

Cited by 13 | Viewed by 2927

Abstract

Within waterborne public transportation (WPT), one often observes a mismatch between the operational requirements and ferry characteristics. A method to holistically evaluate ferries with respect to local requirements could lead to tailored procurement and targeted refurbishment of existing fleet. In this study, we [...] Read more.

Within waterborne public transportation (WPT), one often observes a mismatch between the operational requirements and ferry characteristics. A method to holistically evaluate ferries with respect to local requirements could lead to tailored procurement and targeted refurbishment of existing fleet. In this study, we develop a structure for operational requirements and use it as a basis for a ferry evaluation methodology. The requirements’ structure follows a three-level hierarchy starting from broad vessel design to mandatory requirements to performance requirements. The performance requirements are based on the three pillars of sustainability, aided by commuter surveys carried out in Stockholm ferries, interviews with public transport providers (PTP) and previous literature. The evaluation of the ferry is performed using analytic hierarchic process (AHP) to convert the PTP’s subjective preferences and ferry performance into a single dimensionless index. Rules for quantification of performance metrics including social performance are proposed. The uncertainties associated with AHP are addressed by employing fuzzy AHP based on extent analysis and fuzzy AHP in combination with particle swarm optimization. Two applications including performance assessment of existing ferries and assembly of a modular ferry are discussed. The method can lead to objective decision making in ferry evaluation, potentially leading to a more efficient WPT. Full article

(This article belongs to the Topic Sustainable Transport Systems and New Mobility Services: Challenges and Solutions)

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14 pages, 14166 KiB

Open AccessArticle

Contributions of Wetland Plants on Metal Accumulation in Sediment

by Marelé A. Nel, Gletwyn Rubidge, Janine B. Adams and Lucienne R. D. Human

Sustainability 2022, 14(6), 3679; https://doi.org/10.3390/su14063679 - 21 Mar 2022

Cited by 4 | Viewed by 2228

Abstract

Wetlands, and especially salt marshes, are well-known sinks of metals, which limit toxic amounts of metals from entering the food chain. This study investigated metal concentrations (Cr, Cu, Fe, Mn, Ni, Pb, Zn) in a highly urbanised estuary, and compared vegetated rhizosediment ( [...] Read more.

Wetlands, and especially salt marshes, are well-known sinks of metals, which limit toxic amounts of metals from entering the food chain. This study investigated metal concentrations (Cr, Cu, Fe, Mn, Ni, Pb, Zn) in a highly urbanised estuary, and compared vegetated rhizosediment (Salicornia tegetaria, Spartina maritima, and Zostera capensis) with bare sediment, in a depositional and non-depositional site, in the intertidal zone of the Swartkops Estuary. The samples were collected at two sites along the middle and lower reaches of the estuary and analysed using a Total X-ray Fluorescence (TXRF) spectrometer. It was found that the rhizosediment contained more metals and that metal concentrations in the sediment decreased as follows: S. tegetaria > S. maritima > Z. capensis > bare sediment. Although metal accumulation was similar in bare sediment for the depositional (Site B) and the non-depositional site (Site A), the rhizosediment displayed higher metal accumulation in the depositional site (Site B). However, regardless of site-specific depositional tendencies, rhizosediment displayed higher metal accumulation than bare sediment. These results indicate that vegetated sites and vegetated depositional sites should be the focus of monitoring metals in estuaries around the world. Full article

(This article belongs to the Special Issue Aquatic Plants as Bioindicators of Trace Metal Pollution)

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25 pages, 3427 KiB

Open AccessReview

A Review of Medical Waste Management Systems in the Republic of Korea for Hospital and Medical Waste Generated from the COVID-19 Pandemic

by Cheol-Woo Yoon, Min-Jung Kim, Yoon-Su Park, Tae-Wan Jeon and Min-Yong Lee

Sustainability 2022, 14(6), 3678; https://doi.org/10.3390/su14063678 - 21 Mar 2022

Cited by 32 | Viewed by 10307

Abstract

With the increasing generation of medical waste worldwide, managing medical waste has become crucial, given its potential environmental and public health risks. Previously in the Republic of Korea, medical waste was often mixed with municipal waste and disposed of in residential landfills or [...] Read more.

With the increasing generation of medical waste worldwide, managing medical waste has become crucial, given its potential environmental and public health risks. Previously in the Republic of Korea, medical waste was often mixed with municipal waste and disposed of in residential landfills or unsuitable treatment facilities (e.g., improperly managed incinerators). Environmental regulators and waste producers have made extensive efforts in recent years to improve waste management at healthcare facilities. This study presents an overview of the status of medical waste management in Korea and discusses information on the generation, composition, separation, transportation, and treatment of medical waste. Incineration was confirmed to be the most preferred treatment method for medical waste and was the only one used until late 2005. Large-scale medical waste incinerators are used for treating medical waste from most medical facilities in Korea; however, with increasing regulations on toxic air emissions (e.g., dioxins and furans), air emission standards are being tightened for all existing small-scale incineration facilities without air pollution control. Since medical waste usually contains various plastic materials such as polyvinyl chloride, these incinerators are highly likely to emit toxic air pollutants if improperly operated and managed. Waste minimization and recycling, control of toxic air emissions from medical waste incinerators, and alternative treatment methods to incineration are seen as major challenges. Incineration capacity cannot be expanded as quickly as the rising quantities of medical waste in Korea; thus, there is a growing need to reconsider the overall management system. Accordingly, we examined various medical waste treatment policies and methods that are being implemented in other countries, in addition to the main strategy of waste management. To determine preferable directions for the improvement of the medical waste management system, we investigated and compared the status of domestic and foreign waste management and proposed directions for improvement, focusing on several issues related to the current medical waste management system in Korea. Full article

(This article belongs to the Topic Solid Waste Management)

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