SOCIO-ECONOMIC IMPACTS OF RURAL WATER SUPPLES1

ABSTRACT Development of community water systems in rural areas through the Farmers Home Administration, U. S. D. A., has been marked since the initiation of the program in the early 1%O's. System development in Mississippi has been very rapid and now numbers the largest among the states excepting Texas. Concurrent with this growth, however, has been a concern for operational quality and efficiency as well as questions of community impacts. The paper is purposed with describing the results of research conducted relative to these areas and methods currently being employed or considered for dealing with problematic items.     

When control becomes a liability rather than an asset: Comparing home and office days among part‐time teleworkers

Past research has mainly examined differences between employees working under conventional versus teleworking arrangements or high‐intensity versus low‐intensity teleworking. Yet because many workers combine days worked from the office with days worked from home (part‐time telework), it may be more appropriate to examine within‐individual variation in office versus home days. Accordingly, we compare diary data from 77 employees on three home days and three office days. This setup enables us to contribute to the theoretical debate on the duality of control and accountability. Specifically, by comparing job locations (home versus office), we identify conditions under which job control (worktime control) is more likely to act as an asset or as a liability. Results suggest that ability to concentrate is higher and need for recovery is lower, on home days than on office days. However, on home days, generally high level of worktime control amplifies the association between job demands and need for recovery—whereas this association is reversed when worktime control is generally moderate. No similar differences are observed on office days. Finally, whereas employees experiencing high job demands are more able to concentrate during home days than during office days, worktime control has no differential effect in this respect. Copyright © 2016 John Wiley & Sons, Ltd.     

Developing alternative land-use scenarios to facilitate natural resource management across jurisdictional boundaries

Scenario planning is an effective approach for examining possible futures by exploring the implications and consequences of different policy responses to landscape stressors. We present here a case study that explores plausible futures of urban growth in Southern Nevada, USA that illustrates how scenario analysis can be used to inform region-wide resource management by spatially modeling drivers of change, resource impacts, and potential policy responses. Using a suite of energy, water and biodiversity impact models, we assess the outcomes of the various futures on priority resources, resulting in a clear basis of comparison between alternative policies and their potential outcomes. This case study demonstrates the utility of scenario modeling for natural resource management by exploring crucial policy decisions that might be made in the near-term that could have lasting and sometimes conflicting influences on regional resources over the long term.     

Low temperature autoignition of Jet A and surrogate jet fuel

An experimental study of the low-temperature and low-pressure autoignition of Jet A and surrogate fuels was conducted using the ASTM-E659 standardized test method. Two surrogate fuels (Aachen and JI mixtures), their individual components and two batches (POSF-4658 and POSF-10325) of standardized Jet A were tested using the ASTM-E659 method for a range of fuel concentrations and temperatures. The ignition behaviors were categorized into four distinct ignition modes. The individual hydrocarbon components had a wide range of ignition behaviors and minimum autoignition temperatures (AIT) values depending on the molecular structure. The two Jet A batches showed similar ignition behavior with measured AITs of 229 ±3°C and 225 ±3°C respectively. Both surrogates exhibited similar ignition behavior to Jet A with comparable AITs of 219 ±3.1°C (Aachen) and 228 ±3°C (JI) with the JI mixture proving to be a more suitable surrogate to Jet A in the low-temperature thermal ignition regime.     

Carbonaceous aerosol emissions from India

Budget estimate for carbonaceous aerosols including black carbon (BC) and organic carbon, emitted from the combustion of various fuels, is very important for regional climate studies. Emission factors for carbonaceous aerosols from bio-fuels and soft coke were determined in a controlled combustion study. The emission factors thus obtained along with those available for other fossil fuels consumed in different sectors have been applied to assess the budget for carbonaceous aerosols from India. Preliminary calculations give a range of 1.6–1.8 Tg of carbonaceous aerosols that include 0.4–1.4 Tg of BC. A major (80%) portion of carbonaceous aerosols emitted from India is found to originate from the use of biomass for energy as 70–80% of energy requirement in rural India is met by combustion of traditional bio-fuels.     

柴油机排气控制的研究进展

伴随着柴油机排放标准的日益严格,柴油机排气控制愈来愈受到重视。对降低柴油机微粒和NOx排放的发动机改造、燃料改进和排气后处理技术进行了综述,并指出了今后的努力方向。     

浅谈氮气灭火系统的应用

随着哈龙替代气体研究的不断深入 ,氮气作为惰性气体灭火的一种 ,引起了人们的广泛关注。然而 ,在矿井火灾防治中 ,氮气因其来源广泛、价格低廉 ,很早就得到广泛的应用。笔者对氮气灭火系统的特性、优缺点及其适用范围进行了分析 ,将氮气与其他哈龙替代气体灭火系统进行了比较 ,探讨了引起矿井与建筑火灾扑救差异的原因。针对目前固定式氮气灭火系统应用系统压力较高的特点 ,提出使用长距离输送和制氮机供氮的方法 ,来降低因高压力所带来的成本问题。提出使用氮气灭火系统 ,建立地铁、隧道及地下公共设施等地下建筑物大型火灾的灭火技术     

葡萄糖和硝基苯为混合燃料时MFC的产电特性研究

通过构建双极室微生物燃料电池(microbial fuel cell,MFC),以铁氰化钾溶液为阴极电子受体,以硝基苯(nitrobenzene,NB)和葡萄糖为混合燃料,研究MFC的产电特性和NB的降解情况.结果表明,在外阻为1000Ω的条件下,随着NB初始浓度的增加,双极室MFC的产电特性明显受到抑制.当葡萄糖浓度为1000mg/L,NB初始浓度分别为0、50、150、250mg/L时,MFC的运行周期逐渐缩短,分别为55.7、51.6、45.9、32.2h;最大输出电压分别为670、597、507、489mV;最大体积功率密度分别为28.57、20.42、9.29、8.47W/m3;电荷量分别为65.10、43.50、35.48、30.32C.MFC利用NB和葡萄糖为混合燃料,可以在稳定地输出电能的同时实现有机物高效降解,MFC对NB去除率高达100%,对COD的去除率达到87%～98%.但以250mg/LNB为单一燃料时,MFC无明显产电现象.DGGE图谱表明NB的加入改变了MFC阳极电极上微生物的群落结构.     

基于理化特性的车用燃料着火危险性评价

为了研究在实际使用过程中汽车燃料存在的着火危险性,从燃料理化特性出发,系统分析了各种评价车用燃料着火危险性的参数.采用德尔菲法建立了评价燃料着火危险性的数学模型.研究结果表明:着火的基础是混合气的浓度在着火界限之内,而达到着火界限的难易程度取决于燃料的危险度日值、燃料的蒸发性和燃料的聚集性.当燃料达到着火界限后有自燃和点燃两种着火方式,点燃着火危险性具有实际意义.引入点燃着火危险因子的概念来评价燃料点燃着火危险性.常用燃料的着火危险性由大到小为:氢气、汽油、LJ)G、二甲醚、天然气和柴油.这证明该模型可以用来评价燃料点燃着火危险性. 燃料存在的着火危险性,从燃料理化特性出发,系统分析了各种评价车用燃料着火危险性的参数.采用德尔菲法建立了评价燃料着火危险性的数学模型.研究结果表明:着火的基础是混合气的浓度在着火界限之内,而达到着火界限的难易程度取决于燃料的危险度日值、燃料的蒸发性和燃料的聚集性.当燃料达到着火界限后有自燃和点燃两种着火方式,点燃着火危险性具有实际意义.引入点燃着火危险因子的概念来评价燃料点燃着火危险性.常用燃料的着火危险性由大到小为:氢气、汽油、LPG、二甲醚、天然气和柴油.这证明该模型可以用 评价燃料点燃着火     

气水交替膜生物反应器同步脱氮除碳效能研究

通过长期运行实验,对比研究了气水交替膜生物反应器(gas-water alternative membrane bioreactor,AMBR)和传统淹没式膜生物反应器(submerged membrane bioreactor,SMBR)对模拟生活污水的处理效果.结果表明,两反应器对COD和NH4+-N的去除效果较为类似,去除率均高于96%;SMBR对污染物的去除作用以混合液中的活性污泥为主,而AMBR混合液中的活性污泥量很少,污染物的去除主要依靠附着于中空纤维膜表面微生物的作用.但AMBR比SMBR具有明显的反硝化脱氮优势,AMBR对TN的去除率为76.94%,远高于SMBR的52.41%.此外,通过两反应器长期运行过膜阻力变化规律的研究发现,AMBR比SMBR具有更好的抗膜污染能力.