Degradation of fenamiphos in soils collected from different geographical regions: The influence of soil properties and climatic conditions

The persistence of fenamiphos (nematicide) in five soils collected from different geographical regions such as Australia, Ecuador and India under three temperature regimes (18, 25 and 37°C) simulating typical environmental conditions was studied. The effect of soil properties (soil pH, temperature and microbial biomass) on the degradation of fenamiphos was determined. The rate of degradation increased with increase in temperature. Fenamiphos degradation was higher at 37°C than at 25 and 18°C (except under alkaline pH). The degradation pathway differed in different soils. Fenamiphos sulfoxide (FSO) was identified as the major degradation product in all the soils. Fenamiphos sulfone (FSO₂), and the corresponding phenols: fenamiphos phenol (FP), fenamiphos sulfoxide phenol (FSOP) and fenamiphos sulfone phenol (FSO₂P) were also detected. The degradation of fenamiphos was faster in the alkaline soils, followed by neutral and acidic soils. Under sterile conditions, the dissipation of the pesticide was slower than in the non-sterile soils suggesting microbial role in the pesticide degradation. The generation of new knowledge on fenamiphos degradation patterns under different environmental conditions is important to achieve better pesticide risk management.     

Gemstone mining as a development cluster: A study of Brazil’s emerald mines

For many centuries, emeralds have bejeweled the rich and famous all over the world. Emeralds have also made many millionaires overnight, sometimes by chance, as in some of the cases reported in this study. On the other hand, even though emerald mining has brought some economic benefits, many of these have remained at the top of the production chain. In many cases mining activities have caused a number of negative social and environmental impacts locally. Working conditions in small mines are very poor in general: with bad ventilation, high temperatures, long working hours, lack of safety, informal working contracts and no health or life insurance. Environmental impacts can be significant, such as widespread deforestation, erosion of abandoned mines, and soil and water pollution in streams. The economic and social public benefits can be minimal. Even when taxes on gem mining are relatively low, much of the mining local activity is informal and the high value-added formal activities take place outside the mining regions. This study aims to understand the dynamics of emerald mining and its impact on local development using the concept of clusters. The research analyzes three case studies in Brazil: Campos Verdes/Santa Terezinha (Goias state), Nova Era/Itabira (Minas Gerais state) and Carnaiba/Campo Formoso (Bahia state). Emerald mining regions attract many migrants, increasing the demand for public services (infrastructure, health, education, etc.), but local governments are unable to provide for them because the activity produces little tax revenue. In the end, there is a growing mismatch between demand and supply of public services, leading to a series of social and environmental problems. However, working with the concept of cluster can help to shed light on policies to improve the local benefits of gem mining, by organizing the miners and their supporting organizations to allow investments that bring long term benefits locally.     

基于灰色支持向量机的湿天然气集输管道腐蚀研究

湿天然气集输管道系统运行时间长,管道腐蚀严重,失效泄漏事故频发,其系统风险评价面临诸多问题,因而研究其腐蚀率预测有重要意义。基于灰色支持向量机(GSVM)方法,综合考虑管道材质及其各种影响因素,对其进行灰色相关分析,并根据结果选取有较高相关度的影响因子作为输入变量,将腐蚀率作为目标输出函数,建立湿天然气集输管道腐蚀预测模型。并通过实证分析比较,发现用该模型计算出的管道腐蚀率平均相对误差较小,其预测结果与实际值吻合程度较高,使预测精度得到提高。     

Study on Lockout Procedures for the Safety of Workers Intervening on Equipment in the Municipal Sector in Québec

In Québec, workers intervening in hazardous zones of machines, equipment and processes during maintenance, repairs and unjamming activities have to apply lockout procedures. Lockout procedures involve shutting down the equipment, isolating it, applying individual locks, releasing residual energies and verifying the absence of energies. Lockout has mostly been linked to industrial sectors. However, the municipal sector also faces challenges when it comes to controlling hazardous energies. The objectives of this research are to study serious accidents linked to our subject, study the application of lockout in different municipalities in Québec, identify the specificities for the municipal sector and propose some means to support the application of lockout. We will show that lockout procedures are required in different locations in municipalities and that they are currently being implemented in the municipal sector in Québec. Moreover, we propose a model which aims at facilitating the implementation of lockout procedures in the municipal sector.     

Adsorption Air Cleaning From Ozone

Not much has been written about air cleaning from ozone. The aim of this paper was to demonstrate the possibility of adsorption air cleaning from ozone. The second aim was to investigate the dependence of the efficiency of ozone removal from the air on the height of the adsorber layer and on concentrations of ozone, and to obtain empirical formulas for calculating the efficiency of ozone treatment. Equipment for air cleaning from ozone and nitrogen and sulphur dioxides is suggested.     

3D simulation of hydrogen ignition in a rapid compression machine

Low-temperature (at T < 900–950 K) ignition delays of hydrogen–air mixtures are mainly measured in rapid compression machines (RCM). This communication is aimed at numerical simulation of ignition delays of hydrogen–air mixtures in the RCM by means of a coupled three-dimensional (3D) Unsteady Reynolds-Averaged Navier–Stokes (URANS) – Particle Method (PM) simulation of RCM operation capable of catching turbulence–chemistry interaction. The study indicates that the time history of piston motion in an RCM affects the final state of a test mixture at the end of compression stroke and therefore influences the phenomena relevant to test mixture ignition. More specifically, the calculations show that different laws of piston motion at a fixed average piston velocity (i.e., fixed piston displacement and fixed compression time) and fixed compression ratio result in different evolution of mean pressure, temperature and velocity fields in the RCM test section leading to different ignition behavior. The reasons for the arising differences lie in the fact that the local instantaneous piston velocity determines the roll-up vortex structure, strength and turbulence dissipation in it, heat transfer in test-section walls, and mass leakage through piston rings.     

风力发电设备在我国不同气候条件下环境适应性分析

风力发电设备的环境适应性问题已经引起风电企业的重视,本文介绍了温度、湿度、盐雾、低气压、台风、雷电等环境因素对风力发电设备性能的影响,总结了我国不同地区和不同季节应该关注不同的环境因素,提出了风力发电设备在不同环境因素作用下的防护措施。     

电动汽车用电机及其控制器振动试验方法的探讨

振动试验是汽车产品设计验证和质量检验重要试验方法。本文主要从试验标准、试验条件、振动试验中主要参数的计算推导及应用、试验工装的设计、试验中应注意的问题等方面对电动汽车电机及其控制器的振动试验进行介绍。     

循环喷淋洗涤技术在生产应用中存在的问题及解决方法

中国石油宁夏石化公司采用循环喷淋洗涤技术回收尿素造粒塔粉尘,在该回收系统的运行过程中,存在排气中尿素粉尘含量偏高的情况,从设备管理和工艺优化等方面查找原因,制定应对措施并逐一进行实施,从而降低造粒塔排气中尿素粉尘的含量,减少空气污染,达到了污染减排的目的。     

环保型阻垢剂的研究进展

介绍了近年来循环冷却水系统中环保型阻垢剂的研究进展。重点阐述了价廉无污染的淀粉、单宁、木质素、纤维素、壳聚糖和腐植酸钠等天然高分子环保型阻垢剂,以及目前广泛应用的共聚物类的环保型阻垢剂和聚环氧琥珀酸、聚天冬氨酸、S-羧乙基硫代琥珀酸等新型环保型阻垢剂的阻垢性能和环境降解性能,并对这些阻垢剂的应用现状进行了阐述。而改性和复配是环保型阻垢剂的发展趋势。