POD characterisation of extreme wake patterns of turbulent wind fields past rectangular buildings

Environmental Fluid Mechanics - The turbulent wind fields around three different rectangular building models in two types of simulated atmospheric boundary layer are measured using particle image...     

Decolorization of palm oil mill effluent using growing cultures of Curvularia clavata

Agricultural wastewater that produces color are of environmental and health concern as colored effluent can produce toxic and carcinogenic by-products. From this study, batch culture optimization using response surface methods indicated that the fungus isolated from the pineapple solid waste, Curvularia clavata was able to decolorize sterile palm oil mill effluent (POME) which is mainly associated with polyphenol and lignin. Results showed successful decolorization of POME up to 80 % (initial ADMI [American Dye Manufacturing Index] of 3,793) with 54 % contributed by biosorption and 46 % by biodegradation after 5 days of treatment. Analysis using HPLC and GC-MS showed the degradation of color causing compound such as 3-methoxyphenyl isothiocynate and the production of new metabolites. Ecotoxicity test indicated that the decolorized effluent is safe for discharge. To determine the longevity of the fungus for a prolonged decolorization period, sequential batch decolorization studies were carried out. The results showed that lignin peroxidase and laccase were the main ligninolytic enzymes involved in the degradation of color. Carboxymethyl cellulase (CMCase) and xylanase activities were also detected suggesting possible roles of the enzymes in promoting growth of the fungus which consequently contributed to improved decolorization of POME. In conclusion, the ability of C. clavata in treating color of POME indicated that C. clavata is of potential use for decolorization and degradation of agricultural wastewater containing polyphenolic compounds.     

A 59-year sedimentary record of metal pollution in the sediment core from the Huaihe River,Huainan, Anhui,China

An approximately 59-year (1955–2014) sedimentary record of metal elements (Cu, Pb, Zn, Ni, Co, Mn, and Fe) in a sediment core, collected from the Huaihe River, Huainan City, Anhui Province, China, was reconstructed by using ²¹⁰Pb geochronology. Copper, Zn, Ni, Co, and Mn evaluated by enrichment factor (EF) indicated minor contamination due to water pollution accidents of the Huaihe River that occurred in 1990s and 2004. Lead presented the most severe pollution among the metals studied, especially during 1957–1974. The use of leaded petrol and atmospheric deposition of coal combustion flue gases could have contributed to Pb contamination. In spite of the general good quality (mean sediment pollution index (SPI) 35.69) of the sediment core evaluated by SPI based on the principal component analysis, worse sediment qualities in the upper section (<6 cm, 2004) were still observed, suggesting intensive human activities causing the increasing concentrations of metals in recent decades.     

Examining the effects of feeling trusted by supervisors in the workplace: A self‐evaluative perspective

Trusting and feeling trusted are related but unique components of a trusting relationship. However, we understand relatively little about the effects of felt trust on work performance and organizational citizenship behavior. From a self‐evaluative perspective, this study argued that when employees perceive that their supervisors trust them, their organization‐based self‐esteem is enhanced, leading them to perform better in the workplace. We tested our hypotheses on a sample of 497 teachers using two trust measures, that is, reliance and disclosure, and found support for them on the basis of the reliance (but not the disclosure) measure. The effect of felt trust especially reliance on the employees' work performances were mediated by their organization‐based self‐esteem. Copyright © 2013 John Wiley & Sons, Ltd.     

Double sampling for stratification for the monitoring of sparse tree populations: the example of Populus euphratica Oliv. forests at the lower reaches of Tarim River, Southern Xinjiang, China

Desertification is a pressing issue in the dry Tarim River basin, which is under anthropogenic stresses. In this study, double sampling for stratification (DSS) is employed to inventory Populus euphratica Oliv. forests in the lower reaches of the Tarim River Basin in Xinjiang, China. The two objectives were evaluating DSS as a sampling technique for monitoring desertification and generating baseline information for permanent observation. Here, DSS consists of two phases: in phase 1, crown cover is observed on a large sample of plots on a high resolution satellite image, and these photo-plots are stratified into five crown cover strata. Phase 2 is a stratified random sample from these photo-plots and the sampled plots are field observed. Approximately 32% of the study area is without P. euphratica trees. As expected, estimated mean poplar tree density and basal area increase with crown cover. DSS takes advantages of stratification (fieldwork efficiency and statistical precision) without the need for a priori strata delineation. It proves feasible for inventory the sparse poplar population and holds promise for the assessment of trees outside the forest, where density varies considerably and pre-stratification is intractable. It can be integrated into permanent observation systems for monitoring vegetation changes.     

The Janus face of paternalistic leaders: Authoritarianism,benevolence, subordinates' organization‐based self‐esteem,and performance

We investigated how the two components of paternalistic leadership, namely authoritarianism and benevolence, jointly influenced work performance through their impacts on organization‐based self‐esteem (OBSE). Using a sample of 686 supervisor–subordinate dyads collected from a manufacturing firm in the People's Republic of China, we found that OBSE mediated the negative relationship between authoritarian leadership on one hand and subordinate task performance and organizational citizenship behavior toward the organization (OCBO) on the other. We also found that the negative effect of authoritarian leadership on subordinate OBSE, task performance, and OCBO was weaker when supervisors exhibited higher levels of leader benevolence. Also, OBSE mediated the joint effect of authoritarian leadership and benevolent leadership on subordinate task performance and OCBO. Copyright © 2012 John Wiley & Sons, Ltd.     

Emotional exhaustion and job performance: The moderating roles of distributive justice and positive affect

In a field study among 241 shop assistants and their 59 supervisors in fashion chain stores in Mainland China and Hong Kong, we found a negative relationship between emotional exhaustion and four indicators of job performance (overall performance, emotional display, OCB‐O, and OCB‐I) when employees perceived high levels of distributive justice in the exchange relationship with the organization, whereas emotional exhaustion was unrelated to any of these performance types when employees perceived low levels of distributive justice. In addition, this negative two‐way interaction effect of emotional exhaustion by distributive justice on job performance was buffered when employees were high on positive affect and intensified when they were low on positive affect. We used the conservation of resources (COR) theory, the attribution model of justice, and the broaden‐and‐build theory of positive emotions to clarify and discuss the moderating roles of distributive justice and positive affect in the relationship between emotional exhaustion and job performance. Copyright © 2009 John Wiley & Sons, Ltd.     

Polychlorinated biphenyls (PCBs) in marine fishes from China: Levels, distribution and risk assessment

Muscle tissues of large yellow croakers (Pseudosciaena crocea) and sliver pomfret (Pampus argenteus) from nine coastal cities of East China including Dalian, Tianjin, Qingdao, Shanghai, Zhoushan, Wenzhou, Fuzhou, Quanzhou and Xiamen were analyzed for polychlorinated biphenyl (PCB) concentrations. Thirty-six PCB congeners were quantified in the fishes, of which 11 congeners were dioxin-like PCBs. The total PCB concentrations of the present study were at the low end of the global range, which may be related to the smaller usage and shorter consumption history of PCBs in China. PCBs 18, 29, 52, 66, 101, 104, 138, 153, 180 and 194 were the major constituents found in the fish samples. Regression analysis showed a strong positive correlation (R² = 0.800; p < 0.001) between total dioxin-like PCBs and total PCB concentrations, and that total PCB concentrations explain 80% of the variability in total dioxin-like PCB concentrations. Among the species investigated, significantly higher concentrations of total PCBs were found in croakers than in pomfrets, which may be attributed to their different feeding and living habits. No significant difference in total PCB concentrations among the cities was observed; principal component analysis (PCA) of PCB profiles indicated that PCB pollution came from similar sources in the sampling areas and that there may be other PCB sources in Dalian and Wenzhou. The calculated carcinogenic risks (CRs) from the two species based on a low consumption group and high consumption group were all greater than 10⁻⁶, suggesting that daily exposure to dioxin-like PCBs via fish consumption results in a lifetime cancer risk of greater than one in one million. In contrast, the hazard quotients (HQs) of noncancer risks were all less than unity.