Sustainability

Sustainability of products that seek to maintain ecosystem balance, such as electric vehicles or solar system inverters, often require extensive testing during their developmental stages in a manner that minimizes wastage and drives creativity. Multi-stress accelerated test planning is often used for these products, their subsystems and components if their in-service failures are driven by multiple stress factors. Multi-stress accelerated life testing (ALT) often expedites time to failure for highly reliable products. Many studies assume model parameters that may not be appropriate for the considered stress factors. Most importantly, the effect stress interaction has on the ALT plan is often ignored, especially for cases where historical data are lacking. To address this gap, in this work, a technique based on a combination of rapid experimental data collection and heuristic-based optimization is proposed for ALT planning. In addition, the effect of stress interaction on the ALT plan was also evaluated. Specifically, the Arrhenius model was used to develop a maximum likelihood mathematical expression for multi-stress factor scenarios with and without interaction. Subsequently, two optimization stages based on particle swarm optimization (PSO) were carried out using time varying inertia weight constants to drive early and late global and local searches, respectively. In the first stage, model parameters were estimated, while, in the second stage, an ALT optimal plan was generated based on a D-optimality criterion. Verification of stress factor interactions was carried out using graphical response analysis. An experiment, designed to investigate electromigration in solder joints under three stress factors (temperature, current density and mechanical load), was used to validate the study. The variation in the choice of Latin hypercube design (LHD) results in disparity in the levels of stress within each stress combination as well as sample allocation. Our results clearly show the need to investigate stress interactions prior to multi-stress acceleration planning. Full article

This study focused on smart farms in Korea to confirm that the fourth industrial revolution technology is a tool that can be used for sustainable economic development in agriculture. This study used the input–output table, which included the production-inducing effects of the demand inducement model, value-added inducing effects, supply shortage effects of the supply inducement model, and the interlinkage effect. These methods were used to compare the impact of smart farm machinery on agriculture and the impact of smart farms on the Korean economy compared to conventional agriculture, thereby confirming the extent of the effect of fourth industrial revolution technology on agriculture. This study was conducted to determine whether this agricultural sector could lead to sustainable economic development. The analysis revealed that the production-inducing effects of smart farms showed a greater ripple effect than those of the agricultural sector. However, both value-added inducing effects and supply shortage effects showed a larger ripple effect in the agricultural sector. Considering only the indirect effect, the smart farms were found to evenly affect secondary and tertiary industries. In the case of value-added inducing and supply shortage effects, agriculture was found to have a greater impact on the secondary industry, whereas smart agri-machines and farms had a greater impact on the tertiary industry. Moreover, according to the interlinkage effect, agriculture was classified as a raw industry with final demand, and smart farms as a manufacturing industry with intermediate demand. These results have several implications. For the fourth industrial revolution technology to lead sustainable economic growth in agriculture, continuous creation of new value by developing various types of business models linked to other industries in consideration of the industrial characteristics of smart farms and agri-machines is necessary. In addition, to fully demonstrate the economic effects of smart farms, continuous management and support are required so that smart technologies can be strategically utilized in the agricultural sector. Full article

Information and Communication Technology (ICT) has been acknowledged to be an enabler of small businesses, including those in the informal sector. However, determining the relationship between the perception of technology by informal service providers and the readiness to use technology is critical. By adopting a survey research design, this study investigates how the perception of a web technology portal (WTP) by informal sector service providers in the Cape Town metropolitan area in South Africa affects their readiness to use WTP to support their businesses. The study involved a sampled population of 419 informal sector service providers within the Cape Town metropolis. A conceptual framework consisting of constructs from the self-efficacy theory (SET), the unified theory of acceptance and use of technology (UTAUT) and the technology readiness index (TRI) was used as the theoretical reference for the study. We used a semi-structured questionnaire based on a five-point Likert scale to collect data, which we analyzed using partial least squares structural equation modelling (PLS-SEM). The results showed that discomfort (p = 0.330), effort expectancy (p = 0.630), innovativeness (p = 0.620), optimism (p = 0.740), insecurity (p = 0.110), facilitating conditions (p = 0.160), and internal factors (p = 0.180) all had a non-significant positive influence on e-readiness. On the other hand, self-efficacy (p < 0.001), performance expectancy (p < 0.030), social influence (p < 0.001), and external factors (p < 0.001) had a significant positive influence on e-readiness. Gender and business type, the moderating variables for respondents’ e-readiness, were found to be insignificant (p > 0.005) for e-readiness for web portal technology utilization. This study identifies the key variables that could influence the readiness of informal sector operators to utilize web portal technology. It also provides a guide for designers and developers of digital platforms and government policymakers on critical factors germane to providing technology support for the informal business sector. Full article

Flocculation and dewatering of anaerobically digested sludge is known to be a major cost factor in the economy of wastewater treatment plants. Hence, several endeavors have been underway in search of affordable and effective alternatives. This study focuses on the effects of different metal cations, including FeCl₃, CaCl₂ and MgSO_4, on the dewaterability of digested sludge. The effects of these metal flocculants were also investigated in the presence of co-polymers and surfactants, which can be considered the novelty of this study. The polymers and surfactants investigated in this study were emulsion polymer, CTAB and SDS. Sampling and characterization of digested sludge was conducted, and total solid (TS), volatile solid (VS), dewaterability in capillary suction time (CST), total dissolved solids (TDS), chemical oxygen demand (COD), pH and conductivity of the unconditioned digested sludge samples were determined. The dewaterability of FeCl₃, CaCl₂ and MgSO₄ conditioned digested sludge samples were compared, and MgSO₄ conditioned digested sludge showed better dewaterability compared to the other two metal conditioning agents at a pH of 6.8. The dewaterability was further improved by the addition of emulsion polymer (EMA 8854), cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). Fe Cl₃ was found to perform better under an acidic pH of around 3. The dual conditioning using polymer and CTAB resulted in better dewaterability, with CaCl₂ as metal conditioning agent. Moreover, the effects of pH, metal dose and polymer dose on the dewaterability of digested sludge were also investigated. The effects of metal and polymer conditioning on the particle size of the sludge flocs was also investigated. Optimum dewatering performance was achieved for metal doses of 0.16 v/v, 0.075 v/v and 0.16 v/v for FeCl₃, CaCl₂ and MgSO₄, respectively, and a corresponding CTAB dose of 0.1 v/v and EMA dose of 15 kg/TDS were found to be the optimum. SDS as a polymer conditioning agent resulted in the deterioration of dewatering performance. Full article

Carbon neutrality has been widely acknowledged as a challenge to environmental mitigation and global climate change policy. The current study examines the association between collaboration in climate change mitigation technologies (CMTs), energy productivity (EP), natural resources rent (NRR), renewable energy consumption (REC), and environmentally related tax (ET) on CO₂ emissions for a panel dataset of 30 OECD economies from 1990 to 2020. This paper employs panel data econometric techniques such as AMG, CCEMG, and CS-ARDL. The empirical outcomes show that CMTs, EP, REC, and ET have a negative effect on CO₂ emissions, indicating that their increase will bring about the reduction of carbon emissions, whereas NRR has a positive impact on CO₂ emissions, suggesting that its increase will raise CO₂ emissions. Most interestingly, REC and EP play a leading role in all selected variables by decarbonizing and effectively converting conventional energy into clean, green energy in the process of energy production and utilization. Finally, the OECD countries are anticipated to transition their energy from conventional resources to renewable sources, which will be validated by the increase in energy productivity and the adoption of clean and green technology in the short term. Full article

The widely used dyes in the pharmaceutical, chemical, and medical industries have brought about an intensive concern for the sustainable development of the environment. Membrane separation offers a versatile method for classified recycling and the reuse of residual components. In this work, polyimide membranes were synthesized via the polymerization of 4,4′-(hexafluor-isopropylidene) diphthalic anhydride and 1,4-bis (4-aminophenoxy) benzene diamine. The organic solvent nanofiltration membrane was prepared by casting onto a glass plate and precipitating in the non-solvent phase. The properties of the membranes were recorded by FTIR, ¹HNMR, TGA, and GPC. The molecular simulations were carried out to analyze the affinity between the membrane and different solvents. The membrane was used in the removal of Rose Bengal, methyl blue, Victoria blue B, and crystal violet from methanol. The effects of the feed liquid concentration, operating pressure, swelling degree, organic solvent resistance, and long-term running on the membrane performance were studied. Results showed that membranes prepared in this work demonstrated high solvent permeation and dye rejection due to the sieving effect and solvent affinity. For methyl blue, the solvent performance achieved a permeability of 2.18 L∙m⁻²∙h⁻¹∙bar⁻¹ corresponding to a rejection ratio of 94.2%. Furthermore, the membrane exhibited good stability over 60 h of continued testing. These results recommend a potential strategy in the development of a suitable monomer to prepare a polyimide membrane for dye separation. Full article

The need for continuous global improvement in the construction industry’s current state is inevitable. This pursuit for advancement is to benefit all concerned stakeholders in the construction industry, and innovation has been acknowledged as this improvement measure. Interestingly, Building Information Model (BIM) is a typical example of such innovation in the construction industry. It circumvents human errors, lessening project costs, strengthening productivity and quality, and reducing the project delivery time. This analysis investigates the factors influencing BIM implementation in construction in developing nations. A comprehensive literature review was performed to determine what factors contribute to BIM adoption. These drivers were categorized using exploratory factor analysis (EFA). Partial Least Square Structural Equation Modeling (PLS-SEM) was also used with a questionnaire survey of 100 Nigerian building engineering professionals. Findings from the model highlight the most critical drivers of sustainable BIM deployment. The study’s conclusion will serve as a guideline for policymakers in developing nations that want to finish successful projects by avoiding BIM implementation drivers and improving the accomplishment of building projects via the usage of BIM. Full article

The current work presents a novel microfluidic approach, allowing a full separation of blood cells. The approach relies on using a polydimethylsiloxane serpentine microchannel equipped with a series of electrodes, providing two separation zones. The proposed design exploits the unique configuration of the channel along with the inherent difference in dielectric properties of the three kinds of blood cells to achieve a size-based sorting. The platelets (PLTs) are subjected to a larger dielectrophoretic force than red blood cells (RBCs) and white blood cells (WBCs), forcing them to be separated in the first zone. This leaves RBCs and WBCs to be separated in the second zone. The model developed in this work has been used intensively to examine the feasibility of the proposed approach. The model results showed a full separation of blood content can be achieved over a range of phase flow rates and AC frequencies. Full article

Traditional villages are human treasures left behind by the integration of material space and non-material culture in the process of agricultural civilization. Studying the spatial autocorrelation characteristics, heterogeneity, and quantitative attribution of the factors influencing traditional villages provides new ideas for the protection of traditional villages. This study took 75 traditional villages as the research object. From the perspective of spatial autocorrelation and spatial heterogeneity, the study used nuclear density estimation and Moran’s I index to analyze the spatial distribution patterns and selected 12 factors to construct the GWR modeling and geodetector to analyze the main driving forces and the interaction mechanism. The results showed that, firstly, the overall spatial layout of traditional villages in the Awa Mountain area had two cores, two sides, and a scattered distribution; the global Moran’s I was 0.774, and 55.6% of traditional villages showed a clustering phenomenon. Second, the spatial layout of traditional villages in the Awa Mountain area has been jointly promoted and mutually constrained by multiple factors in a dynamic and complex mechanism with obvious spatial heterogeneity. The natural factor is the basic factor, which determines the location and scale of development of villages; the spatial factor is the auxiliary factor; the social factor is the decisive factor, with a negative global correlation and a positive local correlation; the regional cultural factor is the key factor, and the regional factor and the social factor complement each other; and factors such as a backward economic level, restricted transportation, less external communication, and low population density play a protective role. Third, the main driving factor is the proportion of ethnic minorities (X10), and the explanatory power of q-value reaches 0.54; the proportion of ethnic minorities (X10) ∩ average annual precipitation (X4) has the strongest interactive driving force, which belongs to nonlinear enhancement, and the q-value is 0.93, which proves that the explanatory power of the two-factor model is much greater than the single-factor model from the system perspective. Full article

Soil remediation is the act of removing or reducing the availability of contaminants from soil. In the case of agriculture, soil remediation targets the removal of pollutants, including residual pesticides/herbicides, hydrocarbons, and toxic heavy metals. This is often done by chemical treatments with multiple washes or excavation of soils, which are costly and time-consuming. Therefore, finding cheaper, less time-consuming remediation methods is highly desirable. In this review, we will examine the addition of biochar as an effective method of soil remediation. Biochar is a carbon-rich material derived from burning biomass in an oxygen-limited environment with benefits such as high cation exchange capacity, large surface area, neutral to alkaline pH, and some nutritional content. Biochar can also be a sanctuary for naturally occurring microbes and can be inoculated with specific microbes for contaminant breakdown. The physical and chemical characteristics of biochar combined with biological activity can help bind and promote the degradation process of these contaminants without the need to use hazardous chemicals or remove a large amount of soil. Biochar, and the microbes they house, can bind these contaminants through electrostatic attraction, sorption, precipitation, and bioaccumulation, reducing their availability to the surrounding environment. However, the characteristics of biochar and its biological activity can vary depending on the feedstock, pyrolysis temperature, and time the mass is heated. Therefore, some of these traits can be modified through pre or post-treatments to suit their intended use, allowing for biochar to be made for specific contaminants. This review hopes to increase interest in biochar research to fill in missing gaps of information that could make biochar production cheaper and more consistent, as it offers a greener way to clean up contaminants in soil. Full article

Along with the prevalence of photovoltaic (PV) procurement contracts, the corruption between auctioneers and potential electricity suppliers has attracted the attention of energy regulators. This study considers a corruption-proof environment wherein corruption is strictly suppressed. It elaborates a mechanism to explore the impact of corruption-proof measures on PV procurement auctions. It adopts incentive compatible constraints based on revelation principle to reflect PV firms' optimal utilities. It employs first-price and first-score auctions and uses the Bayesian Nash equilibrium to provide a description of market outcomes. The results show that several strategies have different impacts on social welfare, PV firms' utility, and the benefits of corruption. First, a first-price auction cannot act as a suitable policy because it may encourage corruption. Second, the first-score choice is desirable for social welfare to fit the forthcoming high-quality and low-price surroundings. Third, the first-score strategy maximizes PV firms' utility and total income. The implications suggest that regulators ought not to employ first-price auctions in the future PV market from the perspective of social welfare. Another disadvantage of the first-price approach is that it enables the PV firm to maintain the utmost benefit from corruption. Full article

The focus on developing teacher expertise makes teaching and learning more sustainable, as it is a way of working to create improvement in education. The objective of this study was to explore the direct or indirect impacts of principal instructional leadership and school support on teacher expertise and explore the mediating effect of teachers’ professional development agency. A survey of 1123 teachers was conducted at 21 primary schools and 20 secondary schools in Hebei and Shanxi provinces of northern China. Structural equation modeling and bootstrapping were performed to test the relationships between variables. Results showed that teachers’ professional development agency mediated the effects of principal instructional leadership and school support on teacher expertise. School support was a better predictor of teacher expertise than principal instructional leadership. Providing instructional conditions and leadership support were non-significantly related to teacher expertise. Colleague support and student support were the better predictors of teacher expertise than providing instructional guidance and monitoring. The findings indicate that the growth of teacher expertise depends on building their professional development agency. Teachers will have a strong sense of agency to sustain the teaching profession when principals establish a supportive school climate that emphasizes teaching and learning in their leadership practice and enables teachers to build positive relationships with colleagues and students. The study confirms the supportive factors that impact teacher expertise and provides useful implications for the daily practice of teachers, principals, and administrators. Full article

This article analyzes consumer, local producer, and retailer green orientation regarding local food production and consumption in an urban food market context. This approach extends previous research, mainly focused on green orientation of consumers, by including a broader analysis of the perceptions of different relevant stakeholders. For this purpose, an empirical study was carried out in the context of a local urban market of a medium-sized city through the application of a survey to producers, retailers, and consumers, which included a green orientation scale. Results showed that local consumers and local retailers have a similar high level of green orientation, while local producers are less green-oriented. These conclusions highlight the importance of the green “values” in local communities and the need to reinforce marketing efforts and specific training programs to different stakeholders, namely local producers focused on sustainability. Full article

In the context of “smart cities” and stock-based development, street renewal focuses more on quality and sustainability in China. To improve the efficiency of current smart technology applications, a comprehensive whole-life cycle system needs to be established in street space. After sorting out the application of smart technologies in the street design guidelines (SDGs) for typical cities in China, the compilation and application of smart technologies for sustainability were categorized into five areas: smart transportation, convenient living, life enrichment, the protection of vulnerable people, and environmental monitoring. Based on theoretical support and realistic needs, a smart street management and control platform (SSMCP) was built. The SSMCP is divided into four layers: the basic information layer for the background, the technology platform layer for the core processing, the institutional protection layer for the guarantee mechanism, and the scene application layer for spatial interactions. The results can provide a scientific reference for improving the sustainability of street space and implementing a “smart cities” project at the street level. Full article

The influence of in-plane and out-of-plane element array effects of honeycomb on the impact characteristics of sandwich panels was studied under different local impact speeds. The numerical model is calibrated by air cannon impact experiment and used to conduct the investigations. It is demonstrated that the sandwich panel with in-plane honeycomb core (SPIH) exhibits a response mode with larger local indentation and smaller overall deflection, and also shows superior energy absorption as compared to the sandwich panel with out-of-plane honeycomb core (SPOH). When facing more severe impact conditions, SPIH shows better anti-penetration capability. When the impact radius is 20 mm and the impact velocity is 83 m/s, the SHOP is penetrated while the SHIP is not. When the impact radius is 20 mm and the impact velocity is 100 m/s, the total absorbed energy of SHIP is 59.79% higher than that of SPOH, and the impact residual velocity is 32.67% lower. Furthermore, the impact mitigation performances of SPIH with different density gradient cores are investigated by comparing their deformation modes and energy absorption characteristics. The results indicate that different gradient schemes enable sandwich panels to perform multiple functions. The positive gradient design in the cell stretching direction is beneficial to reduce the overall deflection and improve the energy absorption effect. Full article

Pursuing sustainability in the production inventory model has motivated researchers to reconsider carbon emission costs. In this study, we develop an economic production quantity (EPQ) inventory model to consider greenhouse gas and wastewater emission costs. This study aims to optimize the production quantity, the total costs per production cycle, and the waste emissions. To validate and test the model, data from a pulp and paper mill industry was used. The effectiveness of the model was determined by comparing the costs generated under three (3) scenarios: (1) an EPQ model that considers the costs of greenhouse gas (GHG) emissions; (2) an EPQ model considering shortages; and (3) a multiproduct EPQ model considering shortages. Our proposed sustainable EPQ models can provide decision-makers with insights to visualize how certain factors affect the manufacturing system. Future research can be conducted to consider the product life cycle as well as deteriorating items. Full article

Urban forestry development plans, which sometimes pass under the “slogan” of urban forestry, are a great opportunity for our cities. Improving urban forestscapes is a successful part of any urban sustainability strategy, including concrete actions in support of citizens’ well-being. The experience of Italy with the most recent forest planning legislation and a specific focus on Rome, with the recent implementation of a local forest plan, is thus fundamental to give due weight to the different roles of road trees in the ecological, architectural, engineering and social fields, differentially considering some aspects relevant to urban forestation plans and in particular in projects for the new planting of road trees. The present study discusses the main issue of road trees as a part of the green system, linking the “porosity” of urban landscapes with beneficial contributions in terms of ecosystem services. It is outlined how considering the issue of road trees within the more general question of the structure of urban and metropolitan green areas, which includes urban parks, ecological corridors between wilderness areas, residual green areas of buildings, riparian strips of rivers, agricultural areas, natural and wooded areas, is necessary in current planning for urban forests. The project of new plantings and replacement of existing trees should also follow a careful analysis of the local and regional ecological network, promoting a full integration with the mobility network, the service system and the city’s public spaces, including vacant land. Any strategy promoted by urban forestry, and in particular tree-lined roads, should work in synergy with the other measures for urban redevelopment and landscape enhancement of the city in a truly holistic perspective. Finally, the identity of street tree lines in building the image of a given city should be significantly enhanced, recovering in some ways (and giving value to) the aesthetic and scenic role of urban trees. Full article

Previous studies have observed that increased precipitation positively affects primary production in semiarid grasslands in Inner Mongolia, while soil carbon (C) and nitrogen (N) strongly influence how ecosystems respond to precipitation as well as anthropogenic disturbances under different management strategies. Therefore, in this study, we investigated the storage of organic C and N in four grassland sites with similar flora and landforms but with different grazing intensities to characterize how the storage and concentrations of C and N respond to relief from grazing pressure and precipitation. The concentrations of soil organic carbon (SOC), soil total nitrogen (STN), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN), as well as the contents of soil bacteria and fungi in the 0–50 cm soil layers, were measured. The results showed that SOC, STN, MBC, and MBN storage varied greatly among the four grassland sites (p < 0.05), with all decreasing significantly with grassland degradation and increasing greatly with the exclusion of grazing, i.e., the establishment of natural grassland (NG). More than 90% of C and 95% of N stored in the soil were lost due to heavy grazing, but the losses were smaller in other nutrient pools (including the aboveground biomass, litter, and roots). Interestingly, the proportion of the particle size fractions (clay, silt, and sand) had a stronger effect on limiting the soil and microbial nutrient pools compared to precipitation. The limited range of C and N storage found in these grassland soils indicated that enclosed fencing was a valuable management tool with a high potential to sequester C in the top meter of the soil, showing a stronger effect than precipitation. This study provides a theoretical basis for improving grassland recovery in semiarid areas that have been heavily grazed. Full article

Cowpea is the second most consumed leguminous crop after groundnut in Mali. Its national production was 260,000 tons in 2018. It contributes to nitrogen fixation in the soil. The improved varieties of cowpea cultivars contain traits such as high grain yield, drought resistance, and early maturity. However, the adoption of improved cowpea varieties remains low. The non-participation and or non-consideration of the needs of men and women farmers in the varietal selection process contributed to the low adoption rate of improved cowpea varieties. This study aims to understand the gender dynamics and social structures within the communities. It examines its influence on the adoption of improved varieties of cowpea. Anchored on gender relations theories, gender and social structures are analyzed as the core frame for organizing social relations that guide and coordinate individuals’ actions in a given situation. Qualitative and quantitative approaches were applied to collect data from cowpea growers in 11 villages around the Cinzana Research Station. It emerged from the study that male farmers are quick adopters of newly released cowpea varieties because they are mainly more involved in trials, innovation platforms, field visits, demonstration plot activities, and FPVS than women. Women are less involved in these activities, except in sorting harvested cowpea grains and seeds in the Cinzana Research Station. Women's participation in cowpea related-activities is determined by the rules and norms of physical mobility and the structures that control and guide social interactions and connections within and outside of households and communities. The study recommends efficient resource allocation within households and communities, and the set up of strong institutional frameworks (such as innovation platforms) to enable women in adopting new and improved cowpea varieties and to expand the available opportunities in the cowpea production system. Full article