Influence of construction and demolition waste management on the environmental impact of buildings

The purpose of this study is to quantify comparable environmental impacts within a Life Cycle Analysis (LCA) perspective, for buildings in which the first (Materials) and last (End of Life) life cycle stages are adjusted to several waste/material management options. Unlike most LCAs, the approach is “top-down” rather than “bottom-up”, which usually involves large amounts of data and the use of specific software applications. This approach is considered appropriate for a limited but expedient LCA designed to compare the environmental impacts of different life cycle options.Present results, based on real buildings measurements and demolition contractor activities, show that shallow, superficial, selective demolition may not result in reduced environmental impacts. Calculations actually show an increase (generally less than 5%) in most impact categories for the Materials and End of Life stages because of extra transportation needs. However, core material separation in demolition operations and its recycling and/or reuse does bring environmental benefits. A reduction of around 77% has been estimated in the climate change impact category, 57% in acidification potential and 81% in the summer smog impact (for the life cycle stages referred).     

LOCAL ATTITUDES TOWARD ALTERNATIVE USES OF A RESERVOIR PROJECT1

ABSTRACT: The purpose of this paper is to examine the correlates of attitudes toward alternative uses which could have been made of public resources employed to construct a multipurpose reservoir. A sample of 303 adult residents of a rural community impacted by lake construction was asked to evaluate several alternative development options which could have been implemented in lieu of the lake project. The alternative options evaluated were: rural industrialization, keeping land in agriculture and forests, improving public services, building a state or national park, drilling water wells for urban water supply, aid to small business, helping poor people, building several smaller impoundments, and private recreation development. The findings revealed the local people preferred the lake project to every option except keeping the land in agriculture and forest. Even this option was not strongly supported when compared with the lake project. Socio-demographic, attitude, and cost assessment factors were investigated using a “vested interest” perspective for hypotheses development. These findings demonstrated that costs and benefits were relatively good predictors of attitudes toward alternative development options and were supportive of the theoretical perspective advanced in this paper.     

A Technicoeconomic Approach for the Selection of a Site Remediation Strategy—Part A: Theory

A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine the value of this remediation strategy. The model is an extension of actual cost–benefit analysis, with consideration of “irreversible” remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology. It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially feasible strategies, and how uncertainty on the site's level of contamination affects these strategies.     

Adrift on a sea of platitudes: Why we will not resolve the greenhouse issue

The issue of greenhouse warming has received a great deal of attention in recent years. It has become the object of much scientific scrutiny, media coverage, and political rhetoric. What is our current state of knowledge regarding this phenomenon? What are the possible options for preventing or slowing its advance, or for living with its consequences? What obstructs our taking actions to deal with this issue? These are the questions addressed here. Beginning with a brief overview of our current knowledge, I then examine potential policy options, and finally assess the likelihood of constructive actions. The conclusion reached is that we will probably not deal with this issue, not because we lack a sufficient understanding of the phenomenon, its consequences and workable solutions, but because we lack the philosophical, ethical, and political will to do so. As a result we are likely to continue to drift across a sea of platitudes.     

Estimating the volatility of mining projects considering price and operating cost uncertainties

In the real option pricing model of valuation and decision making, the estimation of future volatility is a key input parameter. For traded commodities or financial assets, past volatility is used as a proxy for predictions. But, for projects, this approach is not feasible because, in most cases, historical data of traded projects are not available. As an alternate solution, it is usually assumed that project volatility is equal to that of commodity price. In order to investigate this assumption, we estimate the project volatility considering that both commodity price and operating cost evolve as a geometric Brownian motion (GBM). Results of a hypothetical gold mining project indicate that project volatility is higher than that of commodity price and it only drops to price volatility under very unrealistic industry conditions, such as very high prices or very low production costs. In addition, we find that project volatility is independent of production capacity and taxation, but depends on increments in price and cost, as well as strongly on their degree of correlation.     

国际碳税方案的比较分析

碳税作为一种控制二氧化碳排放的经济手段受到许多学者的青睐,国外一些学者主张通过在国际层面实行碳税来实现全球二氧化碳减排的目标,并提出了不同的设计构想。但至今仍没有研究者对国际上的国际碳税提议进行系统的归纳。对已有国际碳税提议进行归纳和分析即成为本文的目的。本文将已有典型的国际碳税提议归纳成四种方案,即统一的国际税方案、有差异的国际税方案、统一的国内税方案和国内税+边境调节税方案,分别阐述了每种方案的内容和特征,并运用比较分析的方法从成本效益、公平性、参与广泛性及可操作性四个方面对所归纳的四种方案进行对比分析。通过分析得出,如果仅基于成本效益、公平性、参与广泛性及可操作性四个指标,前三种方案差别不大,但都明显优于第四种方案,因此第四种方案是最劣的。但如果考虑到方案实行的现实条件和推动力,最劣的第四种方案是短期内最可能实现的,并且,最优的国际碳税方案可能需由最劣的方案逐次演化而成,而难以直接实现。     

A Technicoeconomic Approach for theSelection of a Site Remediation Strategy—Part B: Model Application

Different tools, such as a screening matrix or decision framework, are available to select a remediation technology to treat a contaminated site. However, unless these methods can point out the appropriate technology in regards to the decision-maker's knowledge about the contaminated site, they are less useful to evaluate both the technical effectiveness and the cost of the remediation, and to assess different remediation strategies from either future data acquisition or the use of an irreversible remediation technology. A model developed to allow such evaluations has been used to simulate the remediation of a virtual contaminated site. From this, four remediation recommendations have been made. These recommendations are guidelines for the build up of a remediation strategy that would both maximize the effectiveness of the decontamination and minimize its total cost.     

基于多资产期权的土地资源组合开发优化研究

基于土地供应动态价格存在不确定性和期末土地资源的市场推广具有灵活性，土地资源的储备开发价值包括初始投资和期末看涨期权价值。根据欧式多资产期权方法，通过把收益的算术平均近似表达为几何平均的形式，多维问题可以转换为一维问题。参照一篮子期权的几何平均B-S期权定价模型，给出了基于实物期权的多项土地资源储备与开发的算术平均收益的夏普比率优化目标函数。数值计算表明，土地资源配置比例越是均匀，土地储备的期权价值越小。期权价值与配置比例反映为非线性关系。     

Water resource pricing: Policy options

This paper critically examines pricing policy options for water resources and attempts to derive an operationally feasible and socially desirable pricing structure for this important resource. Marginal cost pricing options are studied under different economic and resource conditions, such as inflation, constrained water resources and price distortions in an economy. Options such as pricing of water at its ‘real’ resource value, ‘social’ pricing, and pricing to reflect intangible benefits are also examined.     

常州市水质总体规划方案的多指标决策研究

本文概述了用于水质总体规划研究中的协调规划、协同游戏理论和存优汰劣等3种多指标决策方法。介绍了在常州市水质保护总体规划方案优化研究中应用多指标决策方法,在进行水质效益和费用分析基础上,确定最优的总体规划方案。