Yard waste prediction from estimated municipal solid waste using the grey theory to achieve a zero-waste strategy

Environmental Science and Pollution Research - Yard waste is one of the key components of municipal solid waste and can play a vital role in implementing zero-waste strategy to achieve sustainable...     

Empirical equation for transverse dispersion coefficient based on theoretical background in river bends

There are different approaches to estimating the transverse dispersion coefficient in river mixing. Theoretical approaches have derived the dispersion coefficient from the concept of shear flow, which has dominant effects on the transverse mixing. Empirical approaches have developed an equation using the hydraulic and geometric data of rivers through dimensional analysis and regression techniques. These two equations interact closely with each other. For example, the complicated theoretical equation can be simplified by empirical approaches, and the functional relationships of the empirical equation can be derived from theoretical bases. In this study, a new empirical equation for the transverse dispersion coefficient has been developed based on the theoretical background in river bends. As a regression method, the least-square iterative method was used because the equation was a nonlinear model. The estimated dispersion coefficients derived by the new equation were compared with observed transverse dispersion coefficients acquired from natural rivers and coefficients calculated by the other existing empirical equations. From a comparison of the existing transverse dispersion equations and the proposed equation, it appears that the behavior of the existing formula in a relative sense is very much dependent on the flow condition and the river geometry. Moreover, the proposed equation does not vary widely according to variation of flow conditions. Also, it was revealed that the equation proposed in this study becomes an asymptotic curve as the curvature effect increases.     

Quantification of solid waste management system efficiency using input–output indices

Journal of Material Cycles and Waste Management - The assessment of solid waste management systems is vital for continued improvement in the efficiency of waste management systems (WMSs). Many...     

Employee voice behavior: A meta‐analytic test of the conservation of resources framework

Although voice (i.e. expressing change‐oriented ideas and suggestions) has frequently been investigated as a way for workers to reciprocate to their employers for the positive treatment they receive, much less is known about how workers use voice to deal with stress. This study takes a conservation of resources perspective to examine the relationships among workplace stress, voice behavior, and job performance. We first examined the strength of relationships of three major groups of workplace stressors and strains (job based, social based, and organization based) with voice behavior. We then examined the relationships of voice behavior with performance variables (e.g. in‐role performance and creativity) to investigate how voice may help workers preserve or accumulate resources to enhance their performance. The meta‐analytic findings presented here provide support for a negative relationship between workplace stress and voice and a positive relationship between voice behavior and performance outcomes. Copyright © 2011 John Wiley & Sons, Ltd.     

Risky driving and the perception of motorcycle accident causes among chinese motorcyclists in Hong Kong

Objective: The primary purposes of this study were to explore the relationship between risk-taking acts while driving motorcycles and perceived causes of motorcycle accidents, as well as their contribution to active involvement in traffic accidents among Chinese motorcyclists in Hong Kong. Active involvement means the riders was likely at fault for the crash. Methods: A total of 774 motorcyclists were recruited, of whom 292 had been involved in active motorcycle accident in the previous 3?years. All were asked to fill in a questionnaire, which was developed to assess their risk-taking acts while driving a motorcycle and perception of motorcycle accident causes. Results: The results of the study revealed 3 dimensions of accident causes, namely, driving-related, environment-related, and belief-related causes. These motorcycle accident causes were correlated with risk-taking acts while driving a motorcycle. A multivariate logistic regression analysis showed that risk-taking acts while driving motorcycles (adjusted odds ratio [OR]: 1.036, 95% confidence interval [CI]: 1.020-1.052), perception of driving-related cause (adjusted OR: 0.941, 95% CI: 0.916-0.967), and belief-related cause (adjusted OR: 1.134, 95% CI: 1.088-1.182) were significant factors contributing to involvement in active traffic accidents by motorcycle riders after controlling for concurrent demographic variables. Conclusions: The study highlights that perceived causes of motorcycle accidents are multidimensional, including those areas related to driving, the environment, and beliefs. It substantiates previous studies that a higher degree of driving-related risk perception is related to a lower degree of risk-taking acts while driving. Further research is needed to understand why belief-related causes, sometimes called superstitions, lead riders to believe that it is beyond their ability to affect accident causation and prevention.     

Assessment of soil washing for heavy metal contaminated paddy soil using FeCl3 washing solutions

Environmental Geochemistry and Health - In this study, soil washing is applied for the remediation of heavy-metal (Pb, Cu and Zn) contaminated paddy soil located near an abandoned mine area. FeCl3...     

Functional values of stabilimenta in a wasp spider, Argiope bruennichi: support for the prey-attraction hypothesis

Many orb-weaving spiders decorate their webs with conspicuous ultraviolet (UV)-reflective stabilimenta. The prey-attraction hypothesis suggests that stabilimenta are visually attractive to prey and thus may increase the spiders’ foraging success. However, previous studies on the function of stabilimenta have produced conflicting results in Argiope species. Using a combination of field and laboratory studies, we examined whether the linear stabilimentum of Argiope bruennichi contributes to prey interception. We recorded prey interceptions in 53 webs with stabilimenta and 37 equally-sized webs without stabilimenta, classifying captured prey according to their taxonomical group and size. On average, 6.2?±?4.7 prey items were intercepted in webs with stabilimenta, while 3.2?±?2.9 items were intercepted in webs without stabilimenta. The effects of stabilimenta on foraging success appear to be due to increased interception of UV-sensitive insect pollinators, including 20 families of Diptera, Hymenoptera, Coleoptera, and Lepidoptera. The mean number of UV-sensitive prey was 4.4?±?3.6 in webs with stabilimenta compared with 1.8?±?2.1 in webs without stabilimenta. Webs with and without stabilimenta did not differ in the mean number of UV-nonsensitive prey captured. The linear stabilimentum showed strong positive effects on the interception of large prey: webs with stabilimenta captured more than twice as many large prey (≥5?mm) than webs without stabilimenta, whereas there was only a slight difference in the interception rates for small prey (<5?mm). Comparisons among different Argiope species suggest that the stabilimentum may have different adaptive functions in different species or ecological contexts.     

Gas permeability of biochar-amended clay: potential alternative landfill final cover material

Compacted biochar-amended clay (BAC) has been proposed as an alternative landfill final cover material in this study. Biochar has long been proposed to promote crop growth, mitigate odor emission, and promote methane oxidation in field soils. However, previous studies showed that soil-gas permeability was increased upon biochar application, which will promote landfill gas emission. The objective of the present study is to investigate the possibility of using compacted BAC as an alternative material in landfill final cover by evaluating its gas permeability. BAC samples were prepared by mixing 425-μm-sieved peanut shell biochar with kaolin clay in different ratios (0, 5, 10, and 15 %, w/w) and compacting at different degrees of compactions (DOC) (80, 85, and 90 %) with an optimum water content of 35 %. The gas permeability of the BACs was measured by flexible wall gas permeameter and the microstructure of the BACs was analyzed by SEM with energy-dispersive x-ray spectroscopy (EDX). The results show that the effects of biochar content on BAC gas permeability is highly dependent on the DOC. At high DOC (90 %), the gas permeability of BAC decreases with increasing biochar content due to the combined effect of the clay aggregation and the inhibition of biochar in the gas flow. However, at low DOC (80 %), biochar incorporation has no effects on gas permeability because it no longer acts as a filling material to the retard gas flow. The results from the present study imply that compacted BAC can be used as an alternative final cover material with decreased gas permeability when compared with clay.