磁流体波的穿透对地表电磁环境的影响

本文用两点边值问题的方法数值求解了磁流体波在穿透中纬度电离层和大气层的传播,给出了其对地表电磁环境的影响。在假设磁流体竖直入射,并且大地为理想导体的边界条件下,运用IMSL的子程序BVPFD计算给出了数值结果,数值结果显示磁流体波在穿透电离层和大气层的传播过程中,电场在低电离层和大气层逐渐衰减,在地面达到零,而磁场能够穿透电离层和大气层而到达地面,但在到达地面时衰减了一个量级。这对我们改善环境电磁辐射的监测,去除电磁监测过程中的本底干扰具有一定的启示参考作用。     

露天煤矿道路双侧管路喷雾降尘数值模拟研究

卡车道路运输是露天煤矿最大粉尘源之一,粉尘污染对煤矿职业人群健康、卡车司机能见度均产生影响。湿式喷雾是从产尘根源上解决道路粉尘的有效方法,且喷雾参数直接决定防尘效果及其经济成本。以霍林河北露天煤矿卡车路面为研究背景,采用FLUENT19.2建立卡车道路喷雾降尘模型;分析喷嘴角度、孔径及喷洒量对粉尘浓度的影响机制。研究结果表明：卡车路面粉尘产生机制为碾压破碎、离心抛洒及诱导气;增加颗粒含水率可有效减少扬尘负荷,喷嘴最佳入射角度为30°时,雾距对路面覆盖度良好;喷嘴孔径为10 mm时,斯托克斯碰撞系数最大;喷水量为0.15 L/m2及土壤含水率为4.0%时,路面粉尘控制效果最好。研究结论为有效控制露天煤矿卡车路面运输粉尘提供了理论依据。     

矿山粉尘的浓度指标

矿山粉尘浓度指标是矿山粉尘计量指标中的一项重要指标，是矿山安全环保技术管理和企业管理中的一项重要考核指标。本旨在介绍基本概念，同时介绍矿山粉尘浓度的表示方法和测定方法。     

四川省水泥行业除尘现状及对策

水泥工业是国民经济发展的重要基础材料行业,同时也是高污染行业,尤其是生产过程中的粉尘排放较为严重。四川作为水泥工业大省,粉尘治理工作任重而道远。对四川省水泥行业除尘现状及近三年水泥行业粉尘排放浓度变化情况进行了分析,提出粉尘治理存在的问题及不足,针对四川省的具体情况提出了一些建议和措施。     

LMC低压长袋除尘器在矿热炉烟气治理中的应用

阐述了LMC型低压长袋脉冲喷吹除尘器在矿热炉烟气治理中的成功应用。LMC型除尘器在设计上充分考虑到矿热炉高温烟气温度和粉尘性质对设备的影响,并根据不同烟气温度、粉尘性质及工艺的变化,采用不同配件和材料。     

托盘技术在石灰石—石膏法脱硫中的应用研究

文章介绍了托盘技术在石灰石—石膏法脱硫工艺中的应用.以60MW机组脱硫项目为例,通过比较改造前后的使用情况,得出了托盘技术的投资成本、运行成本更低,对SO2、粉尘等污染物具有更好的脱除效果的结论,同时提出了进一步完善托盘使用的建议.     

稳直流超高压静电除尘技术在水泥粉尘污染防治中的应用

从ＪＧＱ系列稳直流超高压静电除尘器的技术特征、该除尘技术在水泥厂粉尘污染防治工作中的应用等方面加以介绍，并通过实际应用效果监测与评价，提出在青海省推广ＪＧＱ系列稳直流超高压静电除尘器的建议     

长钢烧结厂8m^2竖炉电振污染治理实践

通过全面介绍本单位高产量下竖炉电振粉尘污染治理的思路，实践效果。进一步阐述了高温高压力情况下粉尘污染治理的一般原则和方法。     

湿式静电除尘器在污染物减排治理中的应用

湿式电除尘器对排放烟气中的微细、黏性或高比电阻粉尘,以及烟气中的酸雾、气溶胶、液滴、臭味、重金属、二英等污染物有显著的脱除效果,是深度处理大气污染物的高效设备,已在污染物的减排治理方面得到了广泛应用,但对其系统性论述的文献仍甚少。文章详细分析了湿式静电除尘器的工作原理、不同结构型式、系统组成及关键的应用问题,为类似的工程设计和应用提供参考。     

FE型电袋复合除尘器在大型燃煤机组上的应用

介绍了FE型电袋复合除尘器的特点,以及其在大型燃煤机组上的应用情况,运行结果显示,该新型除尘器不仅可以满足更高的排放要求,而且可以长期稳定运行,并对细微粉尘有更好的捕集效果;可从根本上解决大型燃煤机组粉尘排放的难题。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

Surface applied water treatment residuals affect bioavailable phosphorus losses in Florida sands

Water treatment residuals (WTR) can reduce runoff P loss and surface co-application of P-sources and WTR is a practical way of land applying the residuals. In a rainfall simulation study, we evaluated the effects of surface co-applied P-sources and an Al-WTR on runoff and leacheate bioavailable P (BAP) losses from a Florida sand. Four P-sources, namely poultry manure, Boca Raton biosolids (high water-soluble P), Pompano biosolids (moderate water-soluble P), and triple super phosphate (TSP) were surface applied at 56 and 224kgPha(-1) (by weight) to represent low and high soil P loads typical of P- and N-based amendments rates. The treatments further received surface applied WTR at 0 or 10gWTRkg(-1) soil. BAP loss masses were greater in leachate (16.4-536mg) than in runoff (0.91-46mg), but were reduced in runoff and leachate by surface applied WTR. Masses of total BAP lost in the presence of surface applied WTR were less than approximately 75% of BAP losses in the absence of WTR. Total BAP losses from each of the organic sources applied at N-based rates were not greater than P loss from TSP applied at a P-based rate. The BAP loss at the N-based rate of moderate water-soluble P-source (Pompano biosolids) was not greater than BAP losses at the P-based rates of other organic sources tested. The hazards of excess P from applying organic P-sources at N-based rates are not greater than observed at P-based rates of mineral fertilizer. Results suggest that management of the environmental P hazards associated with N-based rates of organic materials in Florida sands is possible by either applying P-sources with WTR or using a moderate water-soluble P-source.     

Animal Consciousness and Ethics in Asia and the Pacific

The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships. This revised version was published online in July 2006 with corrections to the Cover Date.     

Rehabilitation and Flood Management Planning in a Steep,Boulder-Bedded Stream

This study demonstrates the integration of rehabilitation and flood management planning in a steep, boulder-bedded stream in a coastal urban catchment on the South Island of New Zealand. The Water of Leith, the primary stream flowing through the city of Dunedin, is used as a case study. The catchment is steep, with a short time of concentration and rapid hydrologic response, and the lower stream reaches are highly channelized with floodplain encroachment, a high potential for debris flows, significant flood risks, and severely degraded aquatic habitat. Because the objectives for rehabilitation and flood management in urban catchments are often conflicting, a number of types of analyses at both the catchment and the reach scales and careful planning with stakeholder consultation were needed for successful rehabilitation efforts. This included modeling and analysis of catchment hydrology, fluvial geomorphologic assessment, analysis of water quality and aquatic ecology, hydraulic modeling and flood risk evaluation, detailed feasibility studies, and preliminary design to optimize multiple rehabilitation and flood management objectives. The study showed that all of these analyses were needed for integrated rehabilitation and flood management and that some incremental improvements in stream ecological health, aesthetics, and public recreational opportunities could be achieved in this challenging environment. These methods should be considered in a range of types of stream rehabilitation projects.     

AN INDEX FOR MEASURING THE PERFORMANCE OF IRRIGATION MANAGEMENT SYSTEMS WITH AN APPLICATION1

ABSTRACT: This paper presents a statistically valid index for measuring the performance of irrigation systems. The index is applied to a sample of 39 farms on a watercourse under the warabandi system of irrigation management in India. It is found that while the farmers in fact irrigated almost exactly the total amount of irrigated area as designed, inter-farm variations were considerable. The index shows that the degree of error of managerial effectiveness of irrigation on this watercourse is 20 percent. Therefore it is concluded that the system is performing at 80 percent effectiveness.     

WATER LOSS EQUATIONS AND COEFFICIENTS TO ESTIMATE RUNOFF FROM RAINFALL1

Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found.     

Vegetation dynamics in impounded marshes along the Indian River Lagoon,Florida, USA

Data are presented on the vegetation dynamics of two impounded marshes along the Indian River Lagoon, in east-central Florida, USA. Vegetation in one of the marshes (IRC 12) was totally eliminated by overflooding and by hypersaline conditions (salinities over 100 ppt) that developed there in 1979 after the culvert connecting the marsh with the lagoon was closed. Over 20% recovery of the herbaceous halophytesSalicornia virginica, S. bigelovii, andBatis maritima was observed at that site after the culvert was reopened in 1982, but total cover in the marsh remains well below the original 75%. No recovery of mangroves was observed at this site. The second site (SLC 24), while remaining isolated from the lagoon during much of the study, did not suffer the complete elimination of vegetation experienced at the first site. At this location, mangroves increased in cover and frequency with a concomitant decrease in herbaceous halophytes. Considerable damage to the vegetation was evident at IRC 12 when the impoundment was closed and flooded for mosquito control in 1986. Although the damage was temporary, its occurrence emphasizes the need of planning and constant monitoring and adjustment of management details as conditions within particular marshes change. Storms and hurricanes may be important in promoting a replacement of black mangroves by red mangroves in closed impoundments because the former cannot tolerate pneumatophore submergence for long periods of time. University of Florida-IFAS Journal Series R-00521.