Factors Affecting Take-up of and Drop-out from Home Composting Schemes

This paper reports survey results from Scotland and north-west England into home composting attitudes and behaviours. The results concentrate on: the take-up of home composting through promotional campaigns; and the reasons for drop-out. Motivations for take-up were balanced between environmental and gardening reasons, although capital cost was an important issue for some. Drop-outs occurred mainly through participants moving house or because of lack of success in producing compost. Few of those experiencing problems sought help. Those that did favoured official or professional sources. Neighbourhood social pressures to compost were relatively weak. The results are discussed in terms of the sustainability of home composting behaviour and the manage ment interventions that might be required in sustaining that behaviour.     

Deep bed filtration of anaerobic cattle manure effluents with natural zeolite

Abstract

This study was carried out in a pilot plant for the treatment of anaerobic cattle manure waste. The pilot plant consisted of a semicontinous anaerobic reactor, a settling tank, a filtration process and an ionic exchange column. The study was focused on the filtration process, with natural zeolite as filtering material. In the filtration process different media sizes of natural zeolites packed in columns were tested. The ranges of media size were 0.4 ‐ 1.0, 1.0 ‐ 3.0 and 3.0 ‐ 5.0 mm. Filtration systems operated by gravity flow from 2 to 10 m³m^‐2h^‐1. The process control was done by assays of solids, turbidity, total and soluble COD, ammonium and orthophosphate. The results showed a better behaviour in the filters packed with a media size range between 1.0 and 3.0 mm, operating at 7 m³m^‐2h^‐1, principally when effluent gross particles were previously retained in an Heterogeneous Media Filter, operating at 4 m³m^‐2h^‐1. The head losses diagrams in the filter runs were obtained, at each operational conditions. The hydraulic behaviour of traditional silica sand and natural zeolite beds were compared at the same operational conditions.     

The aerobic soil degradation of spinosad ‐ a novel natural insect control agent

Abstract

Spinosad is a natural product with biological activity against a range of insects including lepidoptera. It is comprised of two major components namely spinosyns A and D. The degradation of spinosad in soil under aerobic conditions was investigated using two U.S. soils (a silt loam and a sandy loam) which were treated with either ¹⁴C‐spinosyn A or ‐spinosyn D at a 2X use rate of 0.4mg/kg soil for spinosyn A and 0.1mg/kg for spinosyn D. Further samples of soil were pre‐sterilised prior to treatment in order to establish whether spinosyns A and D degrade abiotically. Flasks of treated soil were incubated in the dark at 25°C for up to one year after treatment.

HPLC and LC‐MS of soil extracts confirmed that the major degradation product of spinosyn A was spinosyn B, resulting from demethylation on the forosamine sugar. Other dégradâtes were hydroxylation products of spinosyns A and B, with hydroxylation probably taking place on the aglycone portion of the molecule. Half lives were similar for both spinosyns and were in the range 9–17 days, with longer half lives in the pre‐sterilised soils (128–240 days) suggesting that degradation was largely microbial.     

Risk evaluation of natural disasters based on connection function

There are many uncertain factors,such as stochastic,fuzzy and gray information in the risk analysis on natural hazard.The set pair analysis(SPA)deals effectively with the various uncertain factors contributing to evaluation of the risk level of natural disasters.The evaluation indicators and standards of natural disasters risk are analyzed by identity-discrepancycontrary(IDC).The result,the connection numbers,still has uncertainty information.Thus,yielding the risk evaluation model of natural disasters based on connection function,which construct a set pair relation between the indicators of connection numbers and comprehensive evaluation standards,and describe uncertainty of the connection numbers by using connection function.The study showed that the proposed model takes into account only the uncertainty of risk evaluation indicator identification on natural disasters,also the uncertainty of result connection numbers.This approach gives full consideration to the uncertainty of systematic evaluation process along with the actual meaning of comprehensive evaluation functions.Therefore,this means it is able to reduce the uncertainty of final evaluation results and improve the accuracy and reasonability of evaluation results.This model is capable of reflecting actual situation of the risk evaluation on natural disaster affected by various uncertain factors and has a promotional value in the natural disaster risk assessment.     

An “Asymmetric Threat” That Should Have Been Anticipated: Political Discourse on 2007 Wildfires in Greece

This paper examines the pre-election interpretative repertoires employed by the two main political parties in Greece regarding the 2007 summer wildfires, which have been recorded as the worst natural disaster in contemporary Greek history. This involved a discourse analysis of press releases, interviews, and press conference statements. While the New Democracy governing party initially followed a “business-as-usual” scenario, comparing the situation with past wildfires under the administration of PASOK (the biggest opposition party), the increasing number of deaths over time rendered any such comparison invalid. In order to regain momentum, the government launched the interpretative repertoire of “asymmetric threat”, which proved instrumental in helping the government to get re-elected. This political discourse lacked any consideration of broad socioeconomic changes in rural areas in Greece which might have contributed substantially to the severity of the disaster. Implications for wildfire policy are discussed.     

Design of a novel comfort liner for a motorcycle helmet

Natural fibres are nowadays increasingly being employed for producing protective clothing and sportswear. Due to economic and/or environmental considerations they are replacing synthetic materials. The present work provides an insight into the design and development of a novel comfort liner for a motorcycle helmet. The liner is produced from wool and Tunisian alfa fibre. The plant of the alfa fibre is abundantly available in Tunisia. Furthermore, we describe a design concept for a liner that uses these natural fibres and phase change material to improve sweat absorption and perception of thermal comfort. The raw material, the processes involved and the solution to use the phase change material are analysed. The novel comfort liner can facilitate breathability and evaporative transfer of heat in the safety helmet. In addition, it increases comfort, well-being, and provides an indirect message to use natural fibres for textile support to preserve our environment.     

Effect of hydrogen addition to CNG in a biodiesel-operated dual-fuel engine

Alternative fuels for diesel engine applications are gaining more prominence as they have numerous advantages compared to fossil fuels. They are renewable, biodegradable; provide food and energy security and foreign exchange savings. They address environmental concerns and socio-economic issues as well. Gaseous fuels such as compressed natural gas and hydrogenated compressed natural gas (HCNG) appear more attractive fuels for diesel engine applications operated in dual-fuel mode. Such dual fuel engines can replace considerable amount of liquid-injected pilot fuels by gaseous fuels besides being friendly to the environment. A small quantity of liquid fuel injected towards the end of the compression stroke initiates combustion of the inducted gas in the dual-fuel engines. The main advantage of dual-fuel engines is their lower nitrogen oxides (NO_x) and particulate emissions. Hence renewable fuels such as biodiesels and gaseous fuels can be used predominantly for transportation and power generation applications. Gaseous fuels are clean burning and are more economical as well. A suitable carburettor was designed to supply a stoichiometric mixture of air and HCNG to the modified diesel engine operated in dual-fuel mode. The biodiesel used in this study is derived from Honge oil called the Honge oil methyl ester (HOME). This paper presents the performance, combustion and exhaust emission characteristics of a single cylinder, four stroke, direct injection, stationary diesel engine operated on HOME and HCNG in dual-fuel mode. From the results it is observed that HOME–HCNG combination gave lower brake thermal efficiency (BTE) and improved emission levels when compared with diesel/HOME in single fuel operation. Lower smoke and particulate matter were obtained with dual-fuel operation. Comparative measures of BTE, peak pressure, pressure–crank angle variation, smoke opacity, hydrocarbon, carbon monoxide and NO_x emissions have been made and analysed.     

LNG船舶进出港航行移动安全区宽度定量计算分析

为保障液化天然气(LNG)船舶进出港通航安全,提出一种基于LNG船舶碰撞事故概率和风险的LNG船舶移动安全区宽度界定方法。该方法以船舶碰撞概率模型、船舶碰撞损害模型和LNG池火危害模型为基础,计算LNG船舶在航行过程中的事故概率和风险,并根据其分布特征,结合事故概率与风险可接受标准,定量界定LNG船舶移动安全区的宽度。研究表明,LNG船舶移动安全区宽度与通航水域交通流分布、事故船舶的排水量、航行速度等相关。在水上交通管理应用中,可根据LNG船舶及应用水域交通的实际情况确定LNG船舶进出港航行移动安全区的宽度。     

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。     

自然通风对学生宿舍室内苯污染影响的数值模拟

为降低健康风险,采用计算流体力学数值模拟方法,研究了4种不同通风工况对学生宿舍室内苯污染的影响,讨论了室内苯浓度、气流速度矢量与空气龄分布。结果表明：自然通风对于室内苯污染的去除效果明显,进出风口的位置与大小会影响室内气流分布,良好的气流组织更有利于室内污染物的及时排出;出风口对于室内污染物的排出影响较大,增大出风口的面积有利于苯的排出,能更加有效地降低室内苯污染;进风口对室内空气龄影响明显,增大进风口面积能有效提高室内空气的新鲜程度,有利于室内苯污染的稀释,提高学生宿舍室内空气品质。