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11.
ABSTRACT: River Environment Classification (REC) is a new system for classifying river environments that is based on climate, topography, geology, and land cover factors that control spatial patterns in river ecosystems. REC builds on existing principles for environmental regionalization and introduces three specific additions to the “ecoregion” approach. First, the REC assumes that ecological patterns are dependent on a range of factors and associated landscape scale processes, some of which may show significant variation within an ecoregion. REC arranges the controlling factors in a hierarchy with each level defining the cause of ecological variation at a given characteristic scale. Second, REC assumes that ecological characteristics of rivers are responses to fluvial (i.e., hydrological and hydraulic) processes. Thus, REC uses a network of channels and associated watersheds to classify specific sections of river. When mapped, REC has the form of a linear mosaic in which classes change in the downstream direction as the integrated characteristics of the watershed change, producing longitudinal spatial patterns that are typical of river ecosystems. Third, REC assigns individual river sections to a class independently and objectively according to criteria that result in a geographically independent framework in which classes may show wide geographic dispersion rather than the geographically dependent schemes that result from the ecoregion approach. REC has been developed to provide a multiscale spatial framework for river management and has been used to map the rivers of New Zealand at a 1:50,000 mapping scale.  相似文献   
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INTRODUCTION: This paper describes a web-based system for monitoring and assessing construction safety and health performance, entitled the Construction Safety and Health Monitoring (CSHM) system. METHOD: The design and development of CSHM is an integration of internet and database systems, with the intent to create a total automated safety and health management tool. A list of safety and health performance parameters was devised for the management of safety and health in construction. A conceptual framework of the four key components of CSHM is presented: (a) Web-based Interface (templates); (b) Knowledge Base; (c) Output Data; and (d) Benchmark Group. RESULTS: The combined effect of these components results in a system that enables speedy performance assessment of safety and health activities on construction sites. With the CSHM's built-in functions, important management decisions can theoretically be made and corrective actions can be taken before potential hazards turn into fatal or injurious occupational accidents. IMPACT ON INDUSTRY: As such, the CSHM system will accelerate the monitoring and assessing of performance safety and health management tasks.  相似文献   
13.
The potential for oil spills in Arctic regions has increased significantly because of the development of petroleum resources. Response to an oil spill in the Arctic is likely to be much slower than that in the temperate region because of the remoteness of the area and its severe climate. In the face of these unique problems, accurate prediction of the extent and subsequent movement of an oil spill is vital to any cleanup effort. Presented is the framework of a program to study the movement of oil spills in the Arctic. Existing models of oil spreading and polar ice dynamics are reviewed and areas where new model development is required are defined. A system design is developed that may be used for developing a plan to act in the event of a major spill.  相似文献   
14.
Runaway reactions present a potentially serious threat to the chemical process industry and the community; such reactions occur time and time again often with devastating consequences. The main objective of this research is to study the root causes associated with ammonium nitrate (AN) explosions during storage. The research focuses on AN fertilizers and studies the effects of different types of fertilizer compatible additives on AN thermal decomposition. Reactive Systems Screening Tool (RSST) has been used for reactivity evaluation and to better understand the mechanisms that result in explosion hazards. The results obtained from this tool have been reported in terms of parameters such as “onset” temperature, rate of temperature and pressure rise and maximum temperature. The runaway behavior of AN has been studied as a solid and solution in water. The effect of additives such as sodium sulfate (Na2SO4) and potassium chloride (KCl) has also been studied. Multiple tests have been conducted to determine the characteristics of AN decomposition accurately. The results show that the presence of sodium sulfate can increase the “onset” temperature of AN decomposition thus acting as AN thermal decomposition inhibitor, while potassium chloride tends to decrease the “onset” temperature thus acting as AN thermal decomposition promoter.  相似文献   
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This study aggregates the narrative findings from the investigation of 12 accidents or ‘near hits’ across a wide range of industrial settings to build a catalogue of organisational and cultural precursors to accidents. It was found that many were important factors in multiple events. It is argued that by addressing these potential vulnerabilities using the findings and proposed tools based upon them, organisations undertaking safety related activities will not only develop greater awareness of these deeper-lying issues but should be able to better control the risks associated with them.The precursors have been classified under eight headings and examples of key findings from three of these are presented. Statements providing potential defences against the identified vulnerabilities have been developed which should enable organisations to scrutinise the adequacy of existing expectations or requirements within their business. Probing questions have been developed based on the statements which should allow an assessment to be made as to whether these have been ‘embedded’ in the organisation.It is argued that organisational vulnerability tools should be developed to enable a systematic approach to ‘diagnosing’ incubating precursors. It is also argued that there is the potential for further resilience to be achieved through the use of models of the complex dynamics of socio-technical processes within organisations.  相似文献   
17.
为了配合乡、镇发展,须考虑规划兴建大型污水处理厂,以免污水破坏环境;但过往颇多大型污水处理厂出现初投大、使用率低等现像,原因是建造配套市政地下管网涉及更大之投资和复杂的征地、施工等问题,难以配合发展速度解决,或因不明朗因素高估了乡镇的发展需要,种种原因往往导致急速发展的地区浪费国家资源。浮水植物生长迅速、吸收养份的能力特强,美国早在三十多年前应用於处理生活污水,唯因有引起臭味、蚊患等蔽端而未推广,经改良之后受到进一步重视。浮水植物水处理系统大多采用凤眼莲,系统拥有统建设规模弹性、投资小、能耗低和操作易等优点,可作为乡、镇污水处理的一个过渡性选择甚至最终方案考虑。  相似文献   
18.
The electrical instrumentation control systems (EICS) ‘As-built’ documentations of a copper mine were found to possess a significant errors and omissions, which hindered the asset owner’s ability to undertake effective and efficient operations and maintenance. A Systems Information Model (SIM) was used to retrospectively create a connected system to ensure all physical equipment and the associated connections that were constructed are modelled in an object-orientated database. In creating the SIM, the existing errors and omissions in the ‘As-built’ documentation were quantified, and cost savings that could be achieved for a future planned copper mine, with a similar design, were identified. The limitations of using conventional computer-aided-design (CAD) to design and document EICS are discussed. It is recommended that retrospectively creating a SIM can provide owners and operators with significant productivity benefits as well as ensure the asset’s integrity. The case study presented provides asset owners and operators with the empirical evidence to challenge conventional thinking surrounding the design, engineering and documentation of EICS using CAD and alternatively consider the use of SIM.  相似文献   
19.
This paper describes the MICORE approach to quantify for nine field sites the crucial storm related physical hazards (hydrodynamic as well as morphodynamic) in support of early warning efforts and emergency response.As a first step historical storms that had a significant morphological impact on a representative number of sensitive European coastal stretches were reviewed and analysed in order to understand storm related morphological changes and how often they occur around Europe. Next, an on-line storm prediction system was set up to enable prediction of storm related hydro- and morphodynamic impacts. The system makes use of existing off-the-shelf models as well as a new open-source morphological model. To validate the models at least one year of fieldwork was done at nine pilot sites. The data was safeguarded and stored for future use in an open database that conforms to the OpenEarth protocols.To translate quantitative model results to useful information for Civil Protection agencies the Frame of Reference approach ( [Van Koningsveld et al., 2005] and [Van Koningsveld et al., 2007] ) was used to derive Storm Impact Indicators (SIIs) for relevant decision makers. The acquired knowledge is expected to be directly transferred to the civil society trough partnerships with end-users at the end of the MICORE project.  相似文献   
20.
Increasing production of corn masa for tortillas, chips, and related snack foods is resulting in large quantities of organic residuals requiring environmentally sound management. These byproduct streams appear suitable for use as livestock feed material, thus eliminating landfilling costs. Possibilities for developing livestock feed include direct shipping to livestock feeding facilities, blending prior to shipping, extrusion processing, pellet mill processing, and dehydration. To assess the viability of these options for reprocessing masa byproducts as livestock feed materials, an economic model was developed and applied to each of these alternatives. Through a series of simulation runs with this model, it was determined that direct shipping was by far the most inexpensive means of recycling masa processing residuals (10–57 $/Mg). Other alternatives examined in increasing order of costs included blending prior to shipping, extrusion, pellet mill processing (3–15, 5–18, and 4–18 times greater than direct shipping, respectively), while dehydration was clearly cost-prohibitive (33–81 times greater). Bagged feed was slightly more expensive to produce than bulk feed (1.1 times greater), and reprocessing costs increased as delivery distance increased, due to increased labor, equipment, and fuel costs, but decreased as byproduct generation rate increased, due to the development of the economies of scale. Alternately, based on a tipping fee of 50 $/Mg, the total estimated cost to landfill ranged from 65 to 112 $/Mg. Based on this cost analysis, direct shipping and feeding to livestock is the recycling option of choice for masa processing byproducts. Although specific details of process configurations and associated costs will vary, similar results are likely for other high moisture food processing residuals destined for utilization as livestock feed or components thereof.  相似文献   
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