Introduction: Natural Capital, Poverty and Development

Can development occur without running down natural resources in an unsustainable way? The concept of natural capital offers a way for those with divergent views (ecologists and economists for example) to discuss this difficult question. Four aspects are examined in detail. First, the role of institutions in facilitating sustainable development is discussed, with examples from forestry. Then examples from (eco)tourism illustrate the potential – and limits – of applicability of the concept. Measurement issues for natural capital are then considered in detail. Finally, the concept is applied to agricultural strategy in fragile lands, where the tradeoff between the environment and development is likely to be most severe. Some implications for future research and policy are developed.     

Institutions, Forest Management, and Sustainable Human Development – Experiences from India

New institutional economists have argued that there are many categories of institutions, including market and non-market institutions, which may prove economically efficient, specifically for public goods and common pool goods. The Government of India introduced a non-market community-based institution, known as Joint Forest Management (JFM), for forest management and protection in 1990. JFM is a sharing mechanism for forest planning and management based on sharing of rights and duties, control and decision-making authority over forestlands, between forest departments and local user groups. By 2001, 42 000 Village Forest Committees established under JFM were managing over 11.5 million ha forestland. These institutions have proved very useful, and have contributed to forest management as well as four aspects of sustainable human development (SHD) – ecological output, income generation, village infrastructure development, and community empowerment. In the long-term, community-based institutions will prove to be a foundation of SHD and participatory democracy.     

中国国家资源环境安全问题初探

作为世界上最大的发展中国家 ,中国资源环境的现实基础表现出明显脆弱的特征。更严重的问题是 ,未来人口的增长和生活水平的提高对现已十分脆弱的国家资源环境安全基础产生着巨大的压力。若在此问题上出现认识和发展政策上的失误 ,便会产生巨大负面效应 ,严重影响中国国家现代化的进程。为此 ,建议 2 1世纪中国可持续发展战略的首要任务应是确保国家资源环境安全的稳定性。     

Novel Biocomposites Sheet Molding Compounds for Low Cost Housing Panel Applications

Biocomposites were made by a novel high volume processing technique named biocomposite sheet molding compound panel (BCSMCP) manufacturing process. This process design was inspired by the commercial glass fiber–polyester resin composite fabrication method called sheet molding compounding (SMC). This process yields continuous production of biocomposites on a large scale, and thus can be easily adopted in industries. A unique fiber dispersion method, which enabled uniform distribution of natural fibers, was used in this process. Consistency of the process was tested by evaluating the repeatability of the resultant materials mechanical properties. The low cost biocomposites produced as a result of the processing will be used for various panel applications such as housing and transportation. The molded samples were tested for various mechanical and thermal properties, in accordance with ASTM procedures. The biocomposites were made with various natural fibers including, big blue stem grass, jute, and industrial hemp. By combining different natural fibers in varying mass fractions, hybrid biocomposites were made using this process. Grass fiber reinforced polyester biocomposites processed by the SMC line showed very promising results.     

Sustainable Cellular Biocomposites from Natural Fibers and Unsaturated Polyester Resin for Housing Panel Applications

Increased environmental awareness and interest in long-term sustainability of material resources has motivated considerable advancements in composite materials made from natural fibers and resins, or biocomposites. In spite of these developments the lower stiffness and strength of biocomposites has limited their applications to non-load-bearing components. This paper presents an overview of a study aimed at showing that the shortcomings of biocomposites can be overcome through hybrid material designs and efficient structural configurations to make them suitable for load bearing structural components. Hybrid blends of natural and synthetic fibers can significantly improve the characteristics of biocomposites with minimal cost and environmental impact, and hierarchical cellular designs can maximize material efficiency in structural components. Periodic and hierarchical cellular plate designs made from natural fibers and unsaturated polyester resin were evaluated experimentally and analytically. Stiffness, strength, and dimensional stability of all-biocomposite and hybrid natural–synthetic material systems were evaluated through material tests while structural performance of cellular plate designs was assessed through flexural tests on laboratory-scale samples. The experimental results were correlated with analytical models for short-fiber composites and cellular structures. The results showed that biocomposites have adequate short-term performance and that they can efficiently compete with housing panels made from conventional structural materials.     

Role of Amino Acids on <Emphasis Type="Italic">In Situ</Emphasis> Photografting of Jute Yarn with 3-(Trimethoxysilyl) Propylmethacrylate

To improve the mechanical performance of natural lignocellulosic jute yarn, grafting with [3-(trimethoxysilyl) propylmethacrylate] (TMSPM) monomer has been performed on in situ UV radiation and optimized the monomer concentration (30%) and irradiation time (30 min). Effect of various amino acids (1%) as additives in TMSPM with photografted jute yarn at optimized system has been studied. The polymer loading (PL) and tensile properties like tensile strength (TS) and elongation at break (Eb) of treated samples were enhanced by incorporation of amino acids and the highest properties (TS = 300% and Eb = 386%) achieved by the sample treated with l-Arginine (Arg) with 32.5% PL value. Weak acid like 3% acetic acid and inorganic acid like 1% sulfuric acid were also incorporated in the optimized system of TMSPM grafting and compared their effect on the tensile properties with amino acid treated samples. Water absorption and weathering resistance of treated and untreated samples were also performed and treated sample showed lesser water uptake as well as less weight loss and mechanical properties as compared to untreated samples.     

Effect of natural organic matter on arsenic release from soils and sediments into groundwater

Arsenic (As) contamination in groundwater has received significant attention recently. Natural and anthropogenic sources contribute to the worldwide occurrence of As contamination. As speciation is an important factor related to its toxic and mobile behavior. The release of As from soils and sediments into groundwater is governed by several geophysicochemical processes, of which, As sorption behavior is of principle significance. This review paper summarizes existing information regarding the effects of natural organic matter (NOM) on the fate and mobility of As species in the environment. NOM may enhance the release of As from soils and sediments into the soil solution, thereby facilitating As leaching into the groundwater. The main influencing mechanisms include competition for available adsorption sites, formation of aqueous complexes, and/or changes in the redox potential of site surfaces and As redox speciation. NOM may also serve as binding agents, thereby reducing As mobility. However, comparably little research has been performed on this aspect. Since most investigations have been done on purified minerals under laboratory conditions, further research involving various geological materials under natural environmental conditions is required. Development of proper geochemical conceptual models may provide means of predicting the role of NOM in arsenic leaching and/or immobilization.     

城市天然气工程环境风险评价

结合广州、深圳、东莞、佛山等城市的天然气工程情况,对城市天然气工程的环境风险评价进行了讨论,并采用穆尔哈斯(Moorhowse)和普里恰特(Prichard)提出的热辐射预测模式和爆炸冲击波预测模式对城市天然气工程进行了风险评价.结果表明,如果发生天然气泄漏并引起火灾,假设在10 min以内,城市门站、调压站和城市高中压管道的火球对建筑物和设备的严重损害范围( A 级)最远距离分别为35.8 m、18.0 m和28.7 m,爆炸冲击波严重损害范围( C1 级)分别为距事故处54.8 m、27.8 m和44.4 m.最后从城市门站、调压站选址及输气管道选线、安全防范距离、作业过程中的风险控制与管理以及事故应急对策四方面提出了风险事故的防范措施与对策.     

生态伦理:可持续发展理论架构的基础

生态伦理作为可持续发展的基础理论构架的根据．主要体现在：从自然内在价值论与自然权利论的角度出发为可持续发展价值观提供了合理性证明：通过对人与自然间伦理关系的确定、道德原则规范的制定及对人类道德境界的全新诠释,为人类可持续发展提供了新的道德观支持;通过对“环境公正”理论的深入阐发．丰富和完善了“公正”这一可持续发展的核心理念。     

我国Natech事件分布规律及涉水Natech事件致因分析

为弥补我国自然—技术事件(Natech事件)案例研究空白,基于多种数据挖掘方法对近20 a公开报道的自然灾害诱发的技术事故案例进行收集整理,建立了Natech事件数据库.对该类事件时空分布、行业分布进行交叉分析后发现:Natech事件季节特征明显,暴雨和大风是主要肇因,建筑业和交通运输业脆弱性较强.在引入不利气象情景对...