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This study proposes a model linking firm motivations for seeking ISO 14001 certification to the effectiveness of three major components of an environmental management system (EMS)--environmental policy, the assessment of environmental aspect and impacts, and management review. The relationship of these EMS components with a self-reported measure of environmental performance is also examined. From a sample of 29 ISO 14001 certified facilities in Hong Kong (of 71 total certifications at the time the data was collected), it was found that motivations to enhance firm reputation are positively related to perceptions of the effectiveness of the policy statement. Motivations for reputation enhancement and cost reduction were positively related to perceptions of EMS effectiveness in assessing environmental aspects and impacts. The effectiveness of the methodology for identifying environmental aspects and impacts was also found to be positively related to improved environmental performance.  相似文献   
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Population dynamics of weeds in successive maize and bean crops were evaluated in two soil management systems (conventional and no-tillage), for two maize applications (grain and silage), and in four consecutive growing seasons. Every year, conventional tillage consisted in plowing and harrowing before sowing. In no-tillage, chemical weed desiccation was made with the mixture glyphosate + 2.4-D. To control weeds, the mixture fluazifop-p-butil + fomesafen was applied on the bean crop in all the planting seasons, and the herbicides nicosulfuron + atrazine on maize after crop emergence (1998--1999, 1999--2000, 2001--2002) and atrazine + metolachlor before emergence (2000--2001). Purple nutsedge (Cyperus rotundus) was the most important species under conventional soil tillage; while in no-tillage the dicotyledonous weed species (Amaranthus deflexus, Bidens pilosa, Euphorbia heterophylla, Galinsoga parviflora Ipomoea grandifolia) were the most relevant. Regardless of the maize use, the C. rotundus population and tuber bank, with prevailingly dormant tubers, was considerably reduced in no-tillage compared with the conventional system.  相似文献   
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ABSTRACT

Smart and eco-cities have become important notions for thinking about urban futures. This article contributes to these ongoing debates about smart and eco-urbanism by focussing on recent urbanisation initiatives in Asia. Our study of India’s Smart Cities Mission launched under the administration of Narendra Modi and China’s All-In-One eco-cities project initiated by Xi Jinpin unfolds in two corresponding narratives. Roy and Ong’s [2011. Worlding Cities: Asian Experiments and the Art of Being Global. Oxford: Wiley-Blackwell] “worlding cities” serves as the theoretical backdrop of our analysis. Based on a careful review of a diverse set of academic literature, policy and other sources we identify five process-dimensions for analysing the respective urban approaches. We show how the specific features of China’s and India’s urban focus, organisation, implementation, governance and embedding manifest both nations’ approaches to smart and eco-urbanism. We argue that India’s Smart City Mission and China’s All-in-One project are firmly anchored in broader agendas of change that are set out to transform the nation and extend into time. The Indian Smart City Mission is part of a broader ambition to transform the nation enabling her “smart incarnation” in modernity. Smart technologies are seen as the key drivers of change. In China the framework of ecological civilisation continues a 5000-year historical tradition of civilisation excellence. By explicitly linking eco-urbanism to the framework, eco-cities become a means to enact ecological civilisation on the (urban) ground.  相似文献   
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This paper tackles the increasingly significant problem of irrigation-induced soil salinity within a groundwater management model. Irrigation can result not only in heavier salt concentrations but also in the removal of salt from the soil through return flows. Given these contradictory observations, we are interested in the effects on soil salt concentration if irrigation efficiency is improved. We develop a model of salt concentration patterns in both soil and groundwater. We introduce a negative externality to the production process by assuming that soil degradation due to higher soil salinity affects total factor productivity. Within this framework, we show that in the presence of this externality, increasing irrigation efficiency can lead to higher or lower soil salt concentration, depending on the social cost of transferring salt from one reservoir to another.  相似文献   
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Brazil is the world’s main producer of passion fruit. Previous reports show that passion fruit rinds, an industrial waste, contain large amounts of pectin. Pectin is a dietary fiber that is widely used in the food industry as a gelling agent and stabilizer. In this study, the quality and characteristics of pectin extracted from yellow passion fruit rind flour was investigated. Pectin was extracted from both commercially available and prepared passion fruit peels using nitric acid. Once extracted, the pectin was evaluated for its molecular characteristics and chemical composition as well as for the apparent and reduced viscosity of the gel. Prepared (blanched) rind flour yielded 203.4 g kg−1 of pectin, which contained a uronic acid content of 681 mg g−1, a degree of esterification of 80, a degree of methylation of 80, a reduced viscosity of 6.8 dL g−1 and an apparent viscosity of 13.4 cP. The results suggest a clear influence of the raw material on it’s the resultant characteristics of the pectin. In addition, our results show that therheological properties and molar characteristics of pectin were negatively affected when the rind flours were subjected to high temperatures. Pectin methyl esterase activity was detected in the freeze-dried, unblanched raw material. Extensive efforts have been directed towards minimizing waste and the reported results show that high quality pectin can be obtained from passion fruit rinds, an industrial waste product of passion fruit processing.  相似文献   
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Waste management in the building industry in Hong Kong has become an important environmental issue. Particularly, an increasing amount of construction and demolition (C&D) waste is being disposed at landfill sites. In order to reduce waste generation and encourage reuse and recycling, the Hong Kong Government has implemented the Construction Waste Disposal Charging Scheme (CWDCS) to levy charges on C&D waste disposal to landfills. In order to provide information on the changes in reducing waste generation practice among construction participants in various work trades, a study was conducted after 3 years of implementation of the CWDCS via a structured questionnaire survey in the building industry in Hong Kong. The study result has revealed changes with work flows of the major trades as well as differentiating the levels of waste reduced. Three building projects in the public and private sectors were selected as case studies to demonstrate the changes in work flows and the reduction of waste achieved. The research findings reveal that a significant reduction of construction waste was achieved at the first 3 years (2006–2008) of CWDCS implementation. However, the reduction cannot be sustained. The major trades have been influenced to a certain extent by the implementation of the CWDCS. Slight improvement in waste management practices was observed, but reduction of construction waste in the wet-finishing and dry-finishing trades has undergone little improvement. Implementation of the CWDCS has not yet motivated subcontractors to change their methods of construction so as to reduce C&D waste.  相似文献   
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