Global disposal strategies for waste cathode ray tubes

The collection and management of waste electrical and electronic appliances around the world, and the possible negative environmental consequences have been an issue of current debate. Cathode ray tubes (CRTs) used as display screen for computer monitors and televisions contains large quantities of lead, estimated at between 0.5 and 4 kg, depending on the size of the CRT and has been identified as the most polluting of all electronic waste components. Having failed the tests used in the toxicity characterization of solid wastes, CRTs have been declared ‘hazardous’ and subsequently banned from landfills and incinerators in most developed countries. Presently, large quantities of CRTs are generated globally with only few developed countries having effective take back and sound management program. Meanwhile, large quantities of CRT-containing devices are being moved across frontiers into developing countries in the name of ‘reuse’ and ‘bridging the digital divide’. With near absence of recycling infrastructure for electronic wastes in most developing countries, waste CRTs are disposed of with MSW at open dumps and unsanitary landfills. This paper reviews the current practices in the management of CRTs around the world, with emphasis on the role of regulations, availability of recycling infrastructure, recycling/reuse routes, and export into developing countries. Inappropriate disposal of waste CRTs creates the opportunity for large-scale environmental contamination with heavy metals, especially lead. Appropriate disposal routes are required globally in the management of CRTs in order to mitigate environmental contamination and human exposure to toxins.     

Safety related questions for computer-controlled plants: derivation, organisation and application

The use of computers in process control has improved productivity and product quality but has also caused a number of accidents. If we learn from these accidents we may be able to prevent them from happening again. This paper advocates a systematic approach to deriving and organising safety-related questions from past incidents and then applying the questions to consider the safety issues related to the whole life-cycle of computer-controlled plants. Over 170 questions were derived from 300 incident reports provided by two major organisations. The questions are organised into a structured framework so that relevant questions can be located easily when considering different aspects of a computer-controlled plant. Examples illustrating the application of the questions are given. The whole set of questions is listed in the Appendix.     

Use of a geographic information system for storm runoff prediction from small urban watersheds

The use of computer-assisted map analysis techniques for prediction of storm runoff from a small urban watershed in the United States is investigated. An automated procedure for calculating input parameters for the US Soil Conservation Service (SCS) method of predicting storm runoff volume and peak timing is presented. Advanced techniques of spatial analysis are used to characterize spatial coincidence, surface configuration and effective hydrologic distance. A limited verification of the automated procedure indicates that the model reasonably characterizes water flow. A sensitivity analysis of basin disaggregation suggests that the SCS method yields increased volume and peak discharge predictions as the watershed is divided into smaller and smaller subunits. As a means to demonstrate the practical application of the automated procedure, a simulation of the effects on surface runoff for a potential residential development is presented.     

The use of computer models in planning upland land use

The British Ecological Society has suggested that computer‐based techniques could be used in the coordination of policies across different land uses in upland planning. This paper looks briefly at one such technique — a linear programming model — and describes its use at a regional scale for the Sedburgh area in north‐west England. The paper concludes with consideration of why such models are not in more common use.     

Use of computer models of flood inundation to facilitate communication in flood risk management

It is now widely recognised that good communication between multi-disciplinary stakeholders is central to effective flood risk management. Recent developments in Geographical Information Systems, increased availability of accurate digital terrain models from remotely sensed data sources and improved graphical computer interfaces have made the outputs from computer models of flood inundation easily accessible to the stakeholder community. As a consequence, predictions from such models are now being used routinely as a means of communication between engineers and other stakeholders in flood risk management. This paper provides a review of the modelling methods most appropriate for flood risk communication. These are one-dimensional models which are suitable for simulating flood risk at a catchment or sub-catchment scale and appropriate for communicating the impact of strategic flood management decisions and two-dimensional models which can be applied across a range of scales but, are now being regularly applied at the relatively small scale, less than 10 km², where they have the potential to inform and communicate disaster management decisions. The role of such models in communicating between modellers and non-modellers by providing a means for immediate visualisation of “the future” is discussed and illustrated by application to two case studies.     

Development of inherent safety and health index for formulated product design

The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.     

基于GIS的抗震设防区划计算机应用模型

结合抗震设防区划的研究、编制和管理工作,探讨了将抗震设防区划计算机应用模型划分为三个层次的若干设想和建设,并对抗震设防区划计算机应用与发展的某些关键问题进行了讨论。     

铁路车站计算机联锁控制系统的可靠性和安全性分析

铁路车站计算机联锁控制系统 ,直接关系到列车运行的安全。通过可靠性框图分析法 ,对采用不同冗余结构的铁路车站计算机联锁控制系统的可靠性和安全性的指标进行了分析和比较 ,并通过仿真计算对分析和比较的结果进行了验证 ,为铁路车站计算机联锁控制系统的选型提供了技术支持     

Pollution performance of firms from pulp and paper industries

The water pollution emissions by 13 of the largest pulp and paper companies, developed on the basis of monthly reports filed with the US Environmental Protection Agency (EPA) by these companies, indicate a wide disparity in the amount of pollution discharged by them into the nation's waterways. Furthermore, the net discharge of pollution in waterways by all firms is positive, which indicates that all the firms in the study pollute the nation's waterways to some degree. Information presented in this study will be useful for public issues, such as evaluating the effectiveness of the Clean Water Act, government's water pollution policy and abatement strategy, and management's effectiveness in abating water pollution.     

排污收费实用计算机程序

本文就新执行的“四川省超标排污收费管理办法”中的内容，编制了计算机ｆｏｘｂａｓｅ语言程序，专门用于排污收费工作。该技术全部采用汉字录入，操作方便，不用专门的计算机技术，使操作者一看就懂，一学就会，对强化环境执法，提高环境管理的科学化水平，提高工作效率，意义重大。