农户庭院型生态工艺原位处理源分离后的洗涤废水

选择长江三角洲地区有一定代表性的乡村家庭,开展了厌氧池-多级布水模块化人工湿地原位处理源分离后的废水的实例研究,旨在掌握乡村家庭源分离后废水的水质特征,并通过厌氧池-多级布水模块化人工湿地,重点解决乡村家庭源分离后的废水原位净化达标排放问题。结果表明,耗氧有机物(以COD计)、BOD₅、LAS (linear alkylbenzene sulfonates)是洗涤废水、灰水中的主要污染物质;季节变化、进水浓度对厌氧池-多级布水模块化人工湿地处理源分离后的废水中的耗氧有机物、LAS影响不显著,但季节变化对粪大肠菌群影响显著。总体上,2户农户的设施出水均符合《农田灌溉水质标准》(GB 5084-2005)水作作物的相关规定。     

Precipitation of swine and cattle manure phosphorous using limestone dust

The effectiveness of SPS and PULPRO, fine limestone dusts, in precipitating swine and dairy manure phosphorous (P) was determined in the laboratory. Both manures were sieved before being treated with limestone, to reproduce the treatment of mechanically separated manure and to observe the precipitation effect of limestone without that of the large manure solid particles. P precipitation was optimized by varying precipitation conditions (propeller blade speeds, mixing time and limestone levels) and limestone particle size. P precipitation was optimized using a propeller blade mixing speed of 0.3 m s(-1) for at least 5 minutes, using 3% limestone (dry limestone mass over wet manure mass). In terms of particle size, PULPRO 20 (limestone with a particle size of 0.02 mm) produced the most P precipitation and the smallest volume and mass of sludge, as compared to PULPRO 10, PULPRO 3 and SPS (limestone with a particle size of 0.01, 0.003 and 0.3 to 0.003 mm, respectively). For both 9.5% TS (total solids) dairy and 8.8% TS swine manure, mechanical separation followed by limestone precipitation concentrated 90% of manure TS and TP in a sludge volume representing 45% of the initial raw manure mass.     

Protein and amino acid composition of the tergal gland secretions ofBlatta orientalis andEurycotis floridana (Dictyoptera: Blattidae)

Summary Nymphs and adult females ofBlatta orientalis and nymphs ofEurycotis floridana produce a proteinaceous sticky secretion which accumulates on the last abdominal tergites. The proteic patterns do not differ between individuals of the same species. HPLC analyses show that all the common amino acids are found in both species, aspartic and glutamic acids representing 24 to 37% of the total amount of amino acids. InB. orientalis, glutamic acid is the more abundant amino acid whereas inE. floridana it is the aspartic acid. The secretion appears and accumulates rapidly on isolated insects. Behavioural assays revealed that these secretions have a defensive role.     

Work‐to‐nonwork conflict among married male and female lawyers

The primary objective of this study was to examine work‐related factors that were hypothesized to contribute to time‐ and strain‐based work‐to‐nonwork conflict among married male and female lawyers. The findings show that work overload was the only common determinant for both forms of work‐to‐nonwork conflict for both male and female lawyers. Work context was important in understanding female lawyers' feelings of time‐ and strain‐based conflict, where working in a law firm resulted in greater work‐to‐nonwork conflict. For male lawyers, working longer hours, working in a setting with more women and having a wife who held the breadwinner role contributed to their feelings of time‐based conflict. Contrary to what was expected, the actual number of hours worked was not important in influencing married lawyers' feelings of work‐to nonwork conflict. The results show that the domestic status variables were not important for female lawyers' feelings of time‐based conflict and that additional family roles reduces their feelings of strain‐based conflict. It was argued that female lawyers may successfully cope with their demanding careers because they can afford to pay for external sources of child care and domestic assistance, which should be investigated in future research. It was also suggested that working long hours does not automatically lead to work‐to‐nonwork conflict for lawyers because they typically exercise considerable control over the scheduling of their work time, which may allow them to deal with the potentially conflicting demands of their work and nonwork lives. Copyright © 1999 John Wiley & Sons, Ltd.     

Michigan's graduated driver licensing program: evaluation of the first four years

INTRODUCTION: To evaluate the four-year outcome of Michigan's graduated driver licensing (GDL) program, motor-vehicle crash data for 16-year-old drivers in 1996 (pre-GDL), and 1998-2001 (post-GDL) were analyzed. METHOD: Relative risks and 95% confidence intervals for several crash types were computed, and pre-post-GDL population-based crash rates were compared. Reductions in crash risks among 16-year-olds previously found in 1998 and 1999 were generally maintained in 2000 and 2001. RESULTS: Reductions in crash risk among 16-year-olds from 1996 to 2001 were 29% for all, 44% for fatal, 38% each for nonfatal-injury and fatal-plus-nonfatal-injury, 32% for day, 31% for evening, 59% for night, 32% for single-vehicle, and 28% for multi-vehicle crashes. Even after adjusting for more general population-wide changes among drivers 25 years and older that might have contributed to changes in 16-year-old crash risk, reductions remained impressive (19% for all crashes in 2001). IMPACT ON INDUSTRY: As one approach to reducing teenage motor-vehicle morbidity and mortality, GDL remains promising.     

Heavy metals in the polychaete Glycera longipinnis from the southwest of India

Metal concentrations in sediment and in whole tissue of the benthic polychaete Glycera longipinnis collected along the southwest coast of India were analysed. Relative seasonal accumulation of metals (Cu, Pb, Cr, Ni, Zn, Cd, Hg) was studied by categorising the habitat as less polluted or highly polluted based on metal contamination routed through industrial and urban sources. The metal content in tissues varied seasonally in the ranges, Cu: 2.21–27.08 μg·g^?1, Pb: 0.06–4.92 μg·g^?1, Cr: 1.73–29.20 μg·g^?1, Ni: 1.60–4.61 μg·g^?1, Zn: 14.72–82.30 μg·g^?1, Cd: 0.04–1.38 μg·g^?1and Hg: below decetable limits to 0.86 μg·g^?1. Concentration of heavy metals was found to be high in the whole body of G. longipinnis pooled from the polluted transects. The results of this study suggest that G. longipinnis may act as a useful biological indicator for heavy metal pollution along the southwest coast of India.     

Hydrolytic biodegradation of chlorothalonil in the soil and in cabbage crops

Broccoli and Chinese cabbage crops were treated at planting by pouring an emulsion of the fungicide chlorothalonil around the stem of the plant. During culture, chlorothalonil was biodegraded in soil into l,3‐dicarbamoyl‐2,4,5,6‐tetrachlorobenzene (compound 1), l,3‐dicyano‐4‐hydroxy‐2,5,6‐trichlorobenzene (compound 2), and l‐carbamoyl‐3‐cyano‐4‐hydroxy‐2,5,6‐trichlorobenzene (compound 3). Compounds 1 and 2 were the major metabolites in soil. In the harvested broccoli (in the flower) and Chinese cabbages (the leaves), the concentrations of chlorothalonil and of compounds 1 and 2 were lower respectively than 0.1, 0.1 and 0.5mg/kg fresh weight.     

A Parallel Computation Tool to Enable Dynamic Sensitivity and Model Performance Analysis of APEX: Evapotranspiration Modeling

Global sensitivity analysis can be used for assessing the relative importance of model parameters on model outputs. The sensitivity of parameters usually indicates a temporal variation due to variation in the environmental conditions (e.g., variation in weather or plant growth). In addition, the size of averaging window by which the outputs of a model are aggregated or averaged may impact parameter sensitivities. In this study, temporal variation of parameters sensitives, model performance, as well as the impact of the size of time‐averaging window on evapotranspiration (ET) prediction using the Agricultural Policy/Environmental eXtender (APEX) model are investigated. To achieve these goals, an open‐source package named PARAPEX was developed in R and used to perform dynamic sensitivity and model performance analysis of APEX using parallel computation. PARAPEX reduced the computation time from 5,939 to 379 s (using 20 and 1 computation nodes, respectively). The sensitivity analysis results indicated the parameters accounting for the reducing effect of plant cover on evaporation from the soil surface, the effect of soil on the plant root growth, and the effect of cycling and transformation dynamics of organic matter at the top soil layer as the top sensitive parameters based on the mean daily simulated ET and the Nash–Sutcliffe model performance measure. The dynamic performance analysis indicated poor ET predictions by APEX during the growing seasons. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.