Activated fly ash/slag blended cement

This paper presents the results of the preparation of an ecological cementing material from granulated blast-furnace slag (GBFS) and Class C fly ash (CCFA). The desulphurization gypsum, calcined at 600–800 °C for 0.5–1.5 h, works as the main ingredient of the activator in the cementing material. The optimized formulation of the cementing material was obtained with the aid of factorial design method: slag, 70%; CCFA, 18%; activator, 12%. The “partial super-fine grinding process” was adopted to improve the performance, i.e., 85% of the mixture is ground to Blaine fineness of 3500 cm²/g, 15% further ground to around 5000 cm²/g. The compressive strength of 28 days of the cement mortar is up to 49 MPa and flexural strength 8.4 MPa. The hydration products, investigated by SEM and X-ray diffraction, are mainly ettringite and C–S–H gel.     

危险化学品泄漏扩散研究探讨

对危险化学品泄漏扩散的研究是事故应急救援的基础。针对近年来日益增多的危险化学品泄漏事故,本文从数学模型和计算机仿真模拟两方面系统评述了国内外危险化学品泄漏扩散方面的研究,其中数学模型研究主要分为“反求源强”模型和扩散模型两类,计算机仿真模拟主要分为静态离线仿真模拟和实时动态仿真模拟两类。在此基础上,提出了进一步研究的一般框架和研究的方向。     

Possibilities and options for the Clean Development Mechanism and the Green Investment Scheme in Central and Eastern Europe: Macedonian and Romanian perspectives

Central and Eastern Europe (CEE) is a rapidly changing and developing region which is making the transition to a market based economy. Along with economic reforms, the countries of the region are engaged in substantial environmental reforms, including climate change mitigation activities. Mitigation of, and adaptation to, the consequences of climate change are costly processes. It is therefore of great importance that the national and international mechanisms addressing these problems use methods both environmentally sound and economically efficient. Through two case studies that address the Clean Development Mechanism (CDM) in the Former Yugoslav Republic of Macedonia, and the Green Investment Scheme (GIS) in Romania, this paper explores challenges, related tasks and main problems in the establishment of mechanisms of the Kyoto Protocol in Central and Eastern Europe.     

Poly(vinyl alcohol)/Compost Composites for Biofiltration of Swine Waste Volatiles

In this study, a Poly(vinyl alcohol)(PVA)/compost composite bead is prepared and is indicated suitable as a filter material for biofiltration. The optimal preparation process is with the compost size of 16–35 mesh, the ratio of water to compost of 40 g/15 g compost, and the immersion time in the phosphate solution of 60 min. The composite bead prepared by this process is a porous spherical particle with a diameter between 2.4 and 6.0 mm and a density of 0.96 g/cm³. It contains 9.43 mg P/g dry solid and 12.1 mg N/g dry solid. The equilibrium moisture content of the composite bead bed from adsorption and holding experiments is 50.5 and 54.6% on a wet basis respectively, which is about 1.74 times higher than that of swine manure compost bed. It corresponds to the optimal filter material required and is sufficient to sustain biological activity as the composite bead adsorbs equilibrium moisture. The bulk compressive strength of the composite bead bed is about 1.15 times larger than that of swine manure compost bed to ensure even distribution of air flow and reduce the head loss as the air flow stream passed through. The pH value of the filter bed could maintain in the 6.9–7.2 range during the operation period due to the composite bead has the phosphate buffer capacity. The percentage of ethyl acetate removal could remain at over 99% for 40 days operation while the composite beads adsorbed inorganic nitrate nutrients. The pressure drop of two kind composite beads and pig manure compost filter beds are 0 and 2 mm H₂O, respectively, after operating for 40 days.     

How Is Household Vulnerability Gendered? Female‐headed Households in the Collectives of Suleimaniyah,Iraqi Kurdistan

This research tries to reach an understanding of the well-being of female-headed household members through a comparison to male-headed household members in the collectives of the Suleimaniyah governorate in Iraqi Kurdistan. Research was undertaken in five collectives in Suleimaniyah during the summer of 1998. The research contributes to the current gender and development debates which are concerned with improving the understanding of the specific gendered forms of disadvantage faced by female-headed households rather than assuming the universal poverty of this group. An understanding of well-being is approached through a broad conceptualisation of vulnerability in preference to a narrow poverty definition. That the findings of this research are complex attests to the multi-dimensional and mutually constitutive gendered experiences of vulnerability. The definitive conclusion to emerge from this research is a refuting of the rhetoric-fuelled stereotype that households headed by women are at a disadvantage in all the dimensions of vulnerability in comparison to households headed by men. The research also establishes the methodological necessity of examining intra-household distributive mechanisms that determine individuals' well-being.     

环境保护新曙光——纳米材料在环保中的应用

本文介绍了纳米TiO2光催化性的作用机理以及在环境保护中的应用，并对其应用前景及存在的问题作了简要地阐述。此外还介绍了纳米氧化锌及纳米稀土钙钛矿复合氧化物等纳米材料在环境保护中的应用。     

利用粉煤灰制作新型建筑材料

粉煤灰不仅占用大量耕地,而且严重污染环境。针对东营地区粉煤灰的产生现状,积极开发粉煤灰的废物利用。通过对粉煤灰生产空心砌块的原料配比和生产工艺实施的调查,结果表明,利用粉煤灰生产新型建筑材料是减少占地和建材工业征地的有效途径,能变废为宝、化害为利,达到保护环境的目的。     

家庭装修选用管材面面观

家庭装修在管材的选择上与工程建设不同，业主往往因缺乏对管材的基本了解而在众多选择中不知所措。作者对市场上一些常用管材在卫生健康、环保、使用寿命、施工配套等几大方面作出了详细的比较，减少了装修业主选择的盲目性。并根据家庭装修的特点推荐出适宜管材。     

纳米气敏材料的研究与发展趋势

各种气体尤其是对可燃性气体和毒性气体的检测和监控已成为企业当前急需解决的问题之一。纳米技术对提高气敏材料的灵敏度、选择性和长期稳定性有重要的作用,并且能降低工作温度和缩短温度的响应时间。文中论述了氢气、硫化氢、碳氢化合物、氮氧化合物、乙醇、丙酮等气体的纳米气敏材料的研究现状,并对其发展的趋势进行了预测。     

REGIONAL CHARACTERISTICS OF NUTRIENT CONCENTRATIONS IN STREAMS AND THEIR APPLICATION TO NUTRIENT CRITERIA DEVELOPMENT1

ABSTRACT: In order to establish meaningful nutrient criteria, consideration must be given to the spatial variations in geographic phenomena that cause or reflect differences in nutrient concentrations in streams. Regional differences in stream nutrient concentrations were illustrated using stream data collected from 928 nonpoint‐source watersheds distributed throughout the country and sampled as part of the U.S. EPA National Eutrophication Survey (NES). Spatial patterns in the differences were compared and found to correspond with an a priori regional classification system based on regional patterns in landscape attributes associated with variation in nutrient concentrations. The classification consists of 14 regions composed of aggregations of the 84 U.S. EPA Level III Ecoregions. The primary distinguishing characteristics of each region and the factors associated with variability in water quality characteristics are presented. The use of the NES and many other extant monitoring data sets to develop regional reference conditions for nutrient concentrations in streams is discouraged on the basis of sample representation. The necessity that all sites used in such an effort be regionally representative and consistently screened for least possible impact is emphasized. These sampling issues are rigorously addressed by the U.S. EPA Environmental Monitoring and Assessment Program (EMAP). A case‐study, using EMAP data collected from the Central and Eastern Forested Uplands, demonstrates how regional reference conditions and draft nutrient criteria could be developed.