A multilevel perspective of interpersonal trust: Individual,dyadic, and cross‐level predictors of performance

While it is generally known that interpersonal trust facilitates individual functioning, few studies have examined the role of specific features of the interpersonal trust network — individual, dyadic, third‐party, and network‐level features — on individual performance. We adopt a multilevel perspective of interpersonal trust to examine how individuals' performance is not only predicted by their individual‐level centrality in the interpersonal trust network but also moderated, at the network level, by the overall centralized nature of that network. Further, we examine whether mutual trust relationships at the dyadic level, as well as shared trust ties to common third parties, can predict individuals' performance. We test our hypotheses with 206 members in 15 professional networking groups and find that interpersonal trust operates at multiple levels to predict members' performance in terms of generating income from business referrals. These findings provide theoretical and practical implications on how interpersonal trust relationships operate and can be managed for performance gains. Copyright © 2016 John Wiley & Sons, Ltd.     

Electroactive polyamide modified carbon paste electrode for the determination of ascorbic acid

Construction electroactive polyamide (EPA) with aniline-pentamer-based in the main chain has been modified on the surface of carbon paste electrode (CPE) for detecting ascorbic acid (AA). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy studies confirm the well-defined molecular structure of the oligoaniline and EPA. Further, the in situ chemical oxidation of EPA was monitored by UV-Visible absorption spectrum. The electroactivity of the EPA was evaluated by performing electrochemical cyclic voltammetry study. The sensing response studies have revealed that this EPA-modified CPE electrode can detect AA in the range of 0.05–0.7 mM with detection limit of 0.005 mM and sensitivity of 1.5 × 10^–5 AmM^–1. Besides, this EPA-modified CPE electrode shows a minimal relative standard deviation of 1.73%.     

Two-phase modeling of sediment clouds

A sediment cloud release in stagnant ambient fluid occurs in many engineering applications. Examples include land reclamation and disposal of dredged materials. The detailed modeling of the distinct characteristics of both the solid and fluid phases of the sediment cloud is hitherto unavailable in the literature despite their importance in practice. In this paper, the two-phase mixing characteristics of the sediment cloud are investigated both experimentally and theoretically. Experiments were carried out to measure the transient depth penetration and the lateral spread of the sediment cloud and its entrained fluid using the laser induced fluorescence technique, with a range of particle sizes frequently encountered in the field (modeled at laboratory scale). A two-phase model of the sediment cloud that provides detailed predictions of the mixing characteristics of the individual phases is also proposed. The entrained fluid characteristics are solved by an integral model accounting for the buoyancy loss (due to particle separation) in each time step. The flow field induced by the sediment cloud is approximated by a Hill’s spherical vortex centered at the centroid and with the size of the entrained fluid. The particle equation of motion under the effect of the induced flow governs each computational particle. A random walk model using the hydrodynamic diffusion coefficient is used to account for the random fluctuation of particles in the dispersive regime. Overall, the model predictions of the two-phase mixing characteristics are in good agreement with the experimental data for a wide range of release conditions.     

Nitrous oxide generation in denitrifying phosphorus removal process: main causes and control measures

Despite the many benefits of denitrifying phosphorus removal process, the significant generation of nitrous oxide (N₂O), a potent greenhouse gas, remains a problem for this innovative and promising process. To better understand and more effectively control N₂O generation in denitrifying phosphorus removal process, batch experiments were carried out to investigate the main causes of N₂O generation, based on which the control measures were subsequently proposed. The results showed that N₂O generation accounted for 0.41 % of the total nitrogen removal in denitrifying phosphorus removal process, whereas, in contrast, almost no N₂O was generated in conventional denitrification process. It was further demonstrated that the weak competition of N₂O reductase for electrons and the high nitrite accumulation were the two main causes for N₂O generation, evidenced by N₂O production and reduction rates under different conditions. Accordingly, the reduction of N₂O generation was successfully achieved via two control measures: (1) the use of continuous nitrate addition reducing N₂O generation by around 91.4 % and (2) the use of propionate as the carbon source reducing N₂O generation by around 69.8 %.     

城市建筑垃圾的资源化利用

随着建设项目的增多,建筑垃圾也日益增多。本文对建筑垃圾资源化利用进行了初步分析,重点通过对建筑垃圾的分类研究,提出我国建筑垃圾资源化存在问题及建议。     

Effect of metal ions and humic acid on the dechlorination of tetrachloroethylene by zerovalent iron

The dechlorination of tetrachloroethylene (PCE) by zerovalent iron (Fe(0)) in the presence of metal ions and humic acid was investigated. In the absence of metal ion and humic acid, 64% of the initial PCE was dechlorinated after 125 h with the production of ethane and ethene as the major end products. The dechlorination followed pseudo-first-order kinetics and the normalized surface rate constant (k(SA)) for PCE dechlorination was (3.43+/-0.61)x10(-3)lm(-2)h(-1). Addition of metal ions enhanced the dechlorination efficiency and rate of PCE, and the enhancement effect followed the order Ni(II)>Cu(II)>Co(II). The k(SA) for PCE dechlorination in the presence of metal ions were 2-84 times higher than that in the absence of metal ions. X-ray photoelectron spectroscopy (XPS) showed that Cu(II) and Ni(II) were reduced by Fe(0) to zerovalent metals, and resulted in the formation of bimetallic system to accelerate the dechlorination reaction. On the contrary, humic acid out-competed the reactive sites on iron surface with PCE, and subsequently decreased the dechlorination efficiency and rate of PCE by Fe(0). However, the reactivity of Fe(0) for PCE dechlorination in the presence of metal ions and humic acid increased by a factor of 3-161 when compared to the iron system containing humic acid alone. Since humic acid and metal ions are the most often found co-existing compounds in the contaminated aquifers with chlorinated hydrocarbons, results obtained in this study is useful to better understand the feasibility of using Fe(0) for long-term application to the remediation of contaminated sites.     

Degradation of carbofuran in water by solar photocatalysis in presence of photosensitizers

The effect of the presence of photosensitizers, methylene blue (MB) and rose Bengal (RB), on the degradation of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) in water in a solar photocatalytic system was investigated. It was found that as compared to MB, RB generally showed a stronger effect on the decomposition of carbofuran under comparable conditions. Among the conditions studied, adding 2 x 10(-6) M of RB, that corresponding to 2% of the initial concentration of carbofuran solution in the system, rendered the most effective degradation of carbofuran. As a result, a carbofuran removal percentage of 69.9%, a mineralization efficiency of 28.0%, and a microtoxicity reduction of 65.0% could be achieved. The degradation and mineralization of carbofuran was found to follow the pseudo-first order reaction kinetics. The decomposition mechanism of carbofuran was further investigated through identification of the intermediates to elaborate the influence of dye photosensitizer on the solar photocatalysis of carbofuran in water. On the basis of the intermediates identified, including carbofuran phenol, 3-hydroxy carbofuran phenol, and substituted alcohols (3-phenoxy 1-propanol, 2-ethyl 1-hexanol, 2-butoxyl ethanol), it appears that hydrolysis and hydroxylation were the two key mechanisms for decomposing carbofuran during the process of solar photocatalysis with the aid of dye photosensitizer.