Search Results (22)

Food security is an important guarantee for national security and public health. Underground reinforced concrete (RC) grain silos can provide a quasi-low temperature environment for grain storage, effectively ensuring the quality of the stored grain. The stress status of the underground silo during soil backfilling construction is complex, which puts the structure at risk of failure. The present study developed a numerical simulation method to investigate the mechanical properties of underground silos during backfilling construction processes. A finite element (FE) analysis of the backfilling construction process of an underground RC grain silo was conducted, and the nonlinear contact between the underground silo and the surrounding soil, as well as the material nonlinear behavior of the soil, was considered. The deformation characteristics and stress distribution of the underground silo during the backfilling construction process were revealed. The results indicate that the underground RC grain silo exhibits good mechanical performance. The underground silo underwent overall settlement during the backfilling construction process, with a total settlement of 21 mm. The maximum radial displacement of the silo wall and the maximum deflection of the radial primary beam were 0.84 mm and 5.67 mm, respectively, both of which were smaller than the limit values. After the completion of backfilling construction, there was a high risk of concrete cracking of the silo wall. The maximum radial and circumferential tensile stresses of the concrete at the silo top were both high, which led to cracking in the top of the silo. Our research results provide important support for the design and evaluation of underground RC grain silos. Full article

Copper contamination of natural waters is a global problem that affects ecosystems and public health, yet this metal is an essential micronutrient and has important applications. The efficacy of Staphylococcus epidermidis CECT 4183 as a Cu(II) biosorbent in synthetic solutions and its potential ability to synthesize CuO nanoparticles (CuO-NPs) from its cellular extract was investigated. In addition, the biocidal potential of the nanoparticles was evaluated against five microorganisms. Using response surface methodology, the optimal operating conditions were determined to be biomass dose, 0.2 g/L, and pH 5.5. Equilibrium tests were performed, and biosorption isotherms were obtained for four models with a maximum biosorption capacity of 48.14 mg/g for the Langmuir model. Different spectroscopic and microscopic techniques were used to determine the mechanisms involved in the biosorption process, which was dominated by surface physicochemical interactions with strong involvement of methyl, methylene, carbonyl, amino, and phosphate groups. The techniques also allowed for characterizing the obtained nanoparticles, which had a quasi-spherical morphology and an average size of 14 nm. Finally, biocidal tests showed that the CuO-NPs had a good inhibitory capacity for the microorganisms tested, with minimum inhibitory concentrations (MIC) between 62.5 and 500 µg/mL for bacteria and between 1000 and 2000 µg/mL for yeasts. S. epidermidis CECT 4183 showed good potential for Cu(II) bioremediation and for the synthesis of CuO-NPs with biocidal capacity. S. epidermidis CECT 4183 showed good potential for use in Cu(II) biosorption, and its cell extract presented a high capacity for the green synthesis of CuO-NPs, which at the same time turned out to be good biocidal agents. Full article

In Romania, rural communities grapple with decades of depopulation and economic decline, endangering the natural and cultural richness of their landscapes. The implementation of Romania’s 2030 sustainable development plan presents an opportunity to reverse these trends by merging economic and community development with cultural preservation. This paper examines the potential for creating new livelihood opportunities through a program that integrates sustainable agrotourism with culturally appropriate vernacular architecture in Romania’s distinct rural regions. Focusing on two such regions characterized by significant rural population decline yet endowed with ecological services capable of supporting a diverse rural economy, we collaborated with an architect and landscape engineer to devise three specific and detailed agritourist housing scenarios. These scenarios draw upon local architectural forms harmonious with the vernacular landscape, providing accommodations for agrotourism guests and facilitating craft workshops for visitors interested in rural crafts and traditions. We evaluated the cultural appropriateness of the architectural designs through a social survey and assessed the broader social utility of the development plan via an expansive cost–benefit analysis, treating the project’s sustainability features as quasi-public goods. Such interdisciplinary endeavours are essential for effectively bridging conceptually driven social analysis with pragmatic design and planning strategies, essential for achieving sustainable futures for rural communities and landscapes, as exemplified by rural Romania. Full article

Business incubators (BIs) in China have predominantly exhibited a government-led characteristic, recently broadening their spatial and temporal scope and extending reach to the county level. Regarding the inadequacies of county-level analysis scale, this study leverages Points of Interest (POI) big data to overcome them. To comprehend the governmental rationale in the construction of BIs, we examine the evolution dynamics of BIs in conjunction with policies. An economic geography framework is developed, conceptualizing BIs as quasi-public goods and productive services, and incorporating considerations of county-level fiscal operations and industrial structures. Focusing on the Yangtze River Delta (YRD) region as a case study, our findings reveal that over 98% of County Administrative Units (CAUs) have built BIs. Using kernel density estimation and Moran’s I, the spatial patterns of CAUs are identified. The CAUs are further classified into three categories of economic levels using the k-means algorithm, uncovering differentiated relationships between industry, finance, and their respective BI. Additionally, we analyze the density relationship between BIs and other facilities at a micro-level, showcasing various site selection rationales. The discussions highlight that while BIs tend to align with wealthier areas and advanced industries, affluent CAUs offer location advantages on BIs, whereas less wealthy CAUs prioritize quantity for political achievements. This paper concludes with recommendations about aligning BIs based on conditions and outlooks on future research. Full article

Acquiring fundamental movement skills (FMS) in early childhood is linked to long-term engagement in physical activity, promoting lifelong health. Concurrently, the development of self-regulation contributes to fostering socially responsible and empathetic individuals. This study aims to contribute to the sustainable development goals of Good Health and Well-being (Goal 3) and Quality Education (Goal 4) by promoting early education practices that enhance children’s physical and socio-emotional development. This quasi-experimental study, employing a pre/post-test control design, examined the influence of different kindergarten physical education programs on FMS and self-regulation. Participants from a sports-themed kindergarten, ordinary public kindergarten, and non-profit private kindergarten were equally divided into three groups. The “Hello Sunshine” (HS) group followed a ball game-based program; the ordinary physical education (OPE) group’s curriculum had multi-themed physical activities; and the free-play (FP) group as a comparison group (free play) spent their activity time freely playing. Data from a total of 239 children were analyzed, all of whom received identical assessments of fundamental movement skills and self-regulation by the Test of Gross Motor Development-3 (TGMD-3) and the head–toes–knees–shoulders (HTKS) test at baseline and after 10 weeks of the PE curriculum. There was a significant effect of grouping on TGMD-3 composite scores after controlling for the pre-test score (F(2, 235) = 65.232, p < 0.001, Partial η² = 0.357). The composite score of the HS group was clearly higher than that of the OPE (95% CI:10.72~16.45) and FP (95% CI: 4.16~9.98) groups. A significant group time effect was observed for self-regulation (F(2, 236) = 4.588, p = 0.011, Partial η² = 0.037). After 10 weeks, the HS group displayed a more significant increase in self-regulation (14.8%) than that in the OPE (9.7%) and FP (14.6%) groups. The ball game-based program exhibited more advantages in promoting fundamental movement skills and self-regulation among the kindergarteners. Overall, this study’s findings highlight the potential benefits of kindergarten physical education programs and underscore the importance of early childhood development, emphasizing its potential to contribute to holistic child development and align with sustainability goals. Full article

This paper proposes an approach to determining the optimal number of medical specialists in a particular territory. According to the author’s theoretical model, in order to maximise public welfare, the marginal contribution of the last physician recruited to the growth of the public utility function should be equal to the marginal cost of attracting them and providing conditions for their work. To empirically assess the contribution of physicians to the number of lives saved, the CVD mortality rate is modelled using the instrumental variable method. At the level of provision of cardiologists in the amount of 1 per 100,000 people, their marginal contribution to the number of lives saved is not less than 124 per 100,000 people, with a further decrease of 10 per 100,000 people with an increase in the level of provision of one unit. The use of the obtained results will increase the validity of managerial decisions and improve the determination of the optimal number of doctors when choosing between alternative possibilities of spending money on hiring doctors with different profiles or other expenses, especially in the case of limited resources. Full article

Climate change research has received increasing attention from both researchers and the public, and the analysis of precipitation is one of the most important topics in this field. As a supplement to gauge observations, satellite-derived precipitation data present advantages, as they have high spatiotemporal resolution and good continuity. The Global Precipitation Measurement (GPM) mission is the newest generation of precipitation measurement products designed to conduct quasi-global satellite observations. This study used the latest Integrated Multi-satellitE Retrievals for GPM data collected between 2001 and 2020 to analyze changes in precipitation amount, frequency, and intensity on global land and ocean surfaces. The results showed that precipitation intensity over the ocean was generally higher than on land, and the two were more similar at the hourly scale than at the daily scale, as shown by the JS divergence statistics: 0.0323 and 0.0461, respectively. This may be due to the thermodynamic differences between land and the ocean, which can accumulate over a longer time scale. The average number of annual precipitation hours and days increased by 50 h and 5 days during 2011–2020 compared with the previous decade. The absence of obvious changes in annual precipitation amounts led to a decrease in annual precipitation intensity and the weakening of extreme precipitation on land. The analysis of precipitation regimes in nine mainland regions of the globe showed a significant increasing trend for both hourly and daily precipitation in North Asia, while insignificant changes or even decreasing trends were detected in the other regions. The results of this study elucidated the variations in precipitation between land and ocean areas and can contribute to the understanding of global precipitation. Full article

Forestry infrastructure plays a critical role in promoting tree growth to achieve carbon-neutral targets. However, as a quasi-public good, it faces challenges because of its non-excludability, meaning that everyone can use it whether they pay for it or not, which results in a phenomenon known as ‘free-riding’ and poor supply. In China, the government can regulate the supply behaviour by adjusting information feedback approaches, such as disclosing the supply value and revenue. This study examined three information feedback approaches: full feedback (disclosing supply and revenue), half feedback (disclosing only supply), and no feedback (no disclosure). It then combined these three information feedback methods with other three groups of variables, namely whether there was a reward or punishment mechanism, whether the return rate of forestry infrastructure was certain, and whether the foresters could communicate with each other, and 20 policy scenarios were designed. Using experimental economics, foresters’ supply behaviours in these policy scenarios were simulated. The results revealed that: (1) The scenario yielded the highest supply, which is with half feedback, certain return rate of forestry infrastructure, with a reward or punishment mechanism, and no communication. (2) When there is no reward or punishment mechanism, no communication, and the return rate of forestry infrastructure is certain, no feedback increases the supply. In the presence of rewards and punishments, half feedback leads to the highest supply. If there are no rewards or punishments but with a certain return rate and communication, full feedback results in the highest supply. (3) Implementing a reward or punishment mechanism and information feedback simultaneously increases the supply more effectively. The theoretical analysis and policy recommendations of this study aim to improve the supply status of forestry infrastructure. Full article

Sharing new energy vehicles is crucial for addressing the issue of traditional vehicles’ carbon emissions, reducing urban traffic congestion, safeguarding the environment, and promoting citizens’ use of green transportation. However, the parking lot’s drawbacks—poor location, challenging parking, and difficulty finding a car—lead to a low popularity rate, few users, and infrequent use. How to scientifically choose parking outlets and maximize the advantages of sharing new energy vehicles has become an important topic in current urban traffic management. This paper constructed a “G-B-U” framework starting with quasi-public goods and stakeholders to analyze the factors influencing the location selection of these vehicles. On this basis, a three-stage location decision method of “market demand prediction—alternative network screening—location model solution” is proposed to optimize the location selection of shared new energy vehicles. The factors are analyzed, and numerical examples are studied, using the districts of Xuzhou City in China as examples: Gulou, Yunlong, and Quanshan. The findings indicate that the main variables influencing how frequently Xuzhou residents use shared new energy cars are network dispersion, rental and return convenience, and usage experience. After site selection optimization, the journey distance is nearly cut in half, saving users a significant amount of travel time. It may meet the travel needs of residents better based on the same number of parking lots. Full article

Gambling disorder in youth is an emerging public health problem, with adolescents and young adults constituting a vulnerable age group for the development of gambling-related problems. Although research has been conducted on the risk factors for gambling disorder, very few rigorous studies can be found on the efficacy of preventive interventions in young people. The aim of this study was to provide best practice recommendations for the prevention of disordered gambling in adolescents and young adults. We reviewed and synthesized the results of existing RCTs and quasi-experimental studies covering nonpharmacological prevention programs for gambling disorder in young adults and adolescents. We applied the PRISMA 2020 statement and guidelines to identify 1483 studies, of which 32 were included in the systematic review. All studies targeted the educational setting, i.e., high school and university students. Most studies followed a universal prevention strategy, that particularly targeted adolescents, and an indicated prevention strategy for university students. The reviewed gambling prevention programs generally showed good results in terms of reducing the frequency and severity of gambling, and also regarding cognitive variables, such as misconceptions, fallacies, knowledge, and attitudes towards gambling. Finally, we highlight the need to develop more comprehensive prevention programs that incorporate rigorous methodological and assessment procedures before they are widely implemented and disseminated. Full article

In quasi-brittle materials such as concrete, numerical methods are frequently used to simulate the crack propagation for monotonic loading. However, further research and action are required to better understand the fracture properties under cyclic loading. For this purpose, in this study, we present numerical simulations of mixed-mode crack propagation in concrete using the scaled boundary finite element method (SBFEM). The crack propagation is developed based on a cohesive crack approach combined with the thermodynamic framework of a constitutive concrete model. For validation, two benchmark crack-mode examples are modelled under monotonic and cyclic loading conditions. The numerical results are compared against the results from available publications. Our approach revealed good consistency compared to the test measurements from the literature. The damage accumulation parameter was the most influential variable on the load-displacement results. The proposed method can provide a further investigation of crack growth propagation and damage accumulation for cyclic loading within the SBFEM framework. Full article

Forest infrastructure is an important material basis for healthy forests. According to public goods theory, most forest infrastructures are quasi-public goods, with demand exceeding supply, more than one supplier, unclear responsibilities between suppliers, and a resultant free-rider problem. This study explored ways to improve the supply of goods for forest infrastructure when the government—as leader—cooperates with foresters—as followers. Experimental economics were used to explain the factors that influence the behaviour of forest infrastructure quasi-public goods suppliers; to design twelve policy scenarios by communication, information feedback, rewards and punishments, and leadership styles; and to simulate the changes in foresters’ supply behaviour in different scenarios to analyse which policies were conducive to improving the supply of quasi-public forest infrastructures. The results were as follows: communication, rewards and punishments, information feedback, and leadership style reduce foresters’ free-riding behaviour; communication, rewards, and punishment increase supply, and, furthermore, the supply of the scenario with rewards and punishment is 1.792–4.616 times that of the situation without rewards and punishment; without the constraints of rewards and punishment, only feedback information reduces the supply; and the p values of the Mann–Whitney U test for the influence of leadership style on the supply level of forest infrastructure were all greater than 0.05, which indicates that no significant difference exists between leading by words and leading by example in supply improvement. When foresters are able to communicate with each other, reward and punishment exist, and information feedback is provided; hence, the supply of foresters is higher regardless of whether the government leads by words or by example. This study provided policy suggestions on how to improve the supply of quasi-public goods for forestry infrastructure, namely, that the organizer should organize foresters to fully negotiate before raising funds for infrastructure construction; publish, when appropriate, the supply and income of foresters; and formulate appropriate reward and punishment measures. Full article

The farmland shelterbelt is an important artificial ecological project for improving farmland microclimates, ensuring agricultural production, and promoting sustainable development in China’s ecologically fragile areas. Due to the quasi-public attribute, farmland shelterbelts were mainly constructed and managed by the government in the past. In recent years, the reform of the separation of three rights in collective forestland and the mechanism of “private supply of public goods” have prompted farmers to participate in the modern forest management system. However, there is a lack of consistency between farmers’ management intentions and actual contract operation and management behaviors, resulting in weakened management and protection in many places, which seriously restricts the construction efficiency of farmland shelterbelts. Therefore, based on the survey data and planning behavior theory (TPB) of 1106 farmers in 16 major agricultural production areas (counties) in Xinjiang, this study aims to explore the key factors affecting farmers ‘forestry management and production decision making and to verify the transformation mechanism of farmers’ behavior through path analysis. The results show that the management decisions of farmers in ecologically fragile areas follow the path form of “cognitive → intention → behavior”, in which the multi-dimensional cognition of farmers has a significant impact on farmers’ behavioral intention, while the effect on behavioral response is relatively small, which currently depends on the promotion of ecological compensation and government behavior. Finally, this study puts forward countermeasures and suggestions for continuously stimulating the farmers’ forest operation behavior and provides policy reference for promoting the sustainable development of farmland shelterbelts in ecologically fragile areas put forward countermeasures and suggestions for continuously stimulating farmers’ forestry behavior. Full article

An analysis of the following aspects of water economics was undertaken: Water as an Economic and Social Good, Modes of Government Intervention, Water Scarcity in Economic Theory and Agricultural Water Management Changes, with the support of over 300 sources. Emphasis was placed on the connection with primary aspects of economics, in contrast to the usual applicative expositions found in water economics literature. This is a novel approach comparing international bodies’ definitions with economic theory at primary level which leads, upon occasion, to serious contradictions which were exhibited in broad lines. Furthermore, it compares the global implications of these definitions to the existing reality at country level, and a lack of bilateral consistency is exhibited. The uniform picture presented at global level is shown to become a non-uniform one at country level, where sharp variations in resources and availability form a competitive market between nations, and water-rich countries already possessing a competitive advantage are shown to attain a water-based comparative advantage as well. It is shown that although at country level water has a quasi-public good character with minimal private good market existence, this is achieved with the existence of a private goods market at international level via international trade in virtual water. A novel approach to management problems stemming from authority levels starting at global level and ending at farm level is analyzed and redressed by employing reality gap theory. Full article

Based on a tripartite game model among suppliers of public goods, consumers, and the government, a tripartite repeated game model is constructed to analyze the evolution mechanism of which suppliers supply at low prices, consumers purchase, and the government provides incentives, and to establish the dynamics system of a repeated game. The equilibrium points of the evolutionary game are solved, and among them, the equilibrium points are found to satisfy the parameter conditions of ESS. The numerical simulation is employed to verify the impact of penalty coefficients and discount factors on the stability of strategies, which are adopted by the three players in a tripartite repeated game on public goods, and scenario analyses are conducted. The research results of this paper could provide a reference for the government, suppliers, and consumers to make rapid decisions, who are in the supply chain of public goods, especially quasi-public goods, such as coal, water, electricity, and gas, and help them to obtain stable incomes and then ensure the stable operation of the market. Full article