The economics of tire remanufacturing

The world market for tires is described to identify the current material flow from raw materials to tires and the used tire disposal problem. Then, I describe the value-adding operations in the tire production process and in the tire retreading process. Once retreading is identified as the only recovery alternative that maximizes tire utilization, I explain why heat generation is the only recovery alternative, when retreading is not technically feasible. The economic values of heat generation in electric plants and in cement kilns are discussed. The paper culminates with the case of retreading, the tire remanufacturing process and the recommendation of a simple decision rule for selecting the number of times a tire should be retreaded to maximize its utilization.     

MUNICIPAL WATER USE AND WATER RATES DRIVEN BY SEVERE DROUGHT: A CASE STUDY1

ABSTRACT: This paper synthesizes and interprets data pertaining to the evolution of average water revenue, water use, and the average cost of water supply in the City of Santa Barbara, California, from 1986 to 1996, a period which included one of the most devastating droughts in California this century. The 1987–1992 drought hit the study area particularly hard. The City of Santa Barbara was dependent exclusively on local sources for its water supply. That made it vulnerable as the regional climate is prone to extreme variability and recurrent droughts. The 1986–1992 drought provided a rare opportunity to assess the sensitivity of municipal water use to pricing, conservation, and other water management measures under extreme drought conditions. Our analysis indicates that the average cost of water rose more than three-fold in real terms from 1986 to 1996, while the gap between the average cost of supply and the average revenue per unit of water (= 100 cubic feet) rose in real terms from $0.14 in 1986 to $ 0.75 in 1996. The rise of $3.08 in the average cost of supplying one unit of water between 1986 and 1996 measures the cost of hedging drought risk in the study area. Water use dropped 46 percent at the height of the drought relative to pro-drought water use, and remains at 61 percent of the pre-drought level. The data derived from the 1987–1992 California drought are unique and valuable insofar as shedding light on drought/water demand adaptive interactions. The experience garnered on drought management during that unique period points to the possibilities available for future water management in the Arid West where dwindling water supplies and burgeoning populations are facts that we must deal with.     

论环保意识与现代化工企业的营销观

回顾了市场营销对企业发展的核心作用；讨论了环保意识的增强对营销活动的影响以及环保法规与经济调控对企业的巨大压力；介绍了适应时代要求的社会环境营销观的内容及对现代化工企业的影响，并对化工企业如何树立新型营销观进行了探讨。     

用事故树分析法进行炼厂油罐爆炸事故的环境风险评价

论述了风险、风险评价、环境风险评价的概念及其主要内容，说明利用事故树分析法进行工程环境风险评价的程序和方法。并运用这种方法对某炼厂油罐爆炸事故进行了大气环境风险评价。     

岷江都江堰段水环境容量计算及水质综合评价

岷江水域兼有灌溉，供水，发电等多重功能。本文对岷江都江堰段水环境现状进行了模糊综合评价，并计算了水环境容量。     

煤层气勘探开发和利用的环境影响分析

煤层气是煤层中自生自储的一种非常规天然气，其成分主要是甲烷。与煤和石油比较，煤层气是一种清洁能源，因此加快煤层气的开发和利用，能改善能源结构，缓和能源紧张状况，减少环境污染。根据煤层气的特点，详细分析了其对于大气环境、水环境以及土壤、植物的影响因素后指出：开发利用煤层气对大气环境的影响利大于弊，而对水体、土壤、农作物等则产生一系列不利影响。     

SOUND POLICY OR SMOKE AND MIRRORS: DOES ECOSYSTEM MANAGEMENT MAKE SENSE?1

ABSTRACT: Protection of ecosystems as entities on the landscape has attracted a wide range of support. Ecosystem-based public policies are claimed to be more effective, efficient, and scientifically sound than other approaches to environmental and natural resource policy. The ecosystem concept was never intended to serve as a public policy guide or to determine landscape units for land management purposes. This paper critically examines the use of the ecosystem concept in public policy and land use management and analyzes the proposed rule to manage the National Forest System according to ecosystem management principles. The concept is found to be unsuitable as a basis for guiding environmental and natural resource public policies in general while the proposed rule to manage the national forests according to ecosystem management principles is shown to be incoherent.     

INTEGRATED RIVER BASIN OPTIMIZATION: MODELING ECONOMIC AND HYDROLOGIC INTERDEPENDENCE1

ABSTRACT: This paper presents an integrated optimal control model that optimizes economic performance of reservoir management in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the General Algebraic Modeling System (GAMS). Results show that application of this model to New Mexico's Rio Chama basin can increase total system benefits over historical benefits by exploiting complementarities between hydroelectricity production, instream recreation, and downstream lake recreation.     

城市可持续发展政策的取向与反思

本文对城市可持续发展进行了概述，从物理环境、经济环境和社会环境的相互作用的角度分析了城市可持续发展的政策取向，对当今的可持续发展的政策进行反思，提出了建立环境公平促进可持续发展的政策思路。     

电力工业发展与环境保护

从我国电力工业发展历程、面临的主要环境问题、污染控制等方面全面简述我国电力工业环境保护取得的发展与成就；展望“十一五”电力发展目标及电力环保指标；分析了为实现环境目标需要实施的污染控制措施。