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151.
This paper presents a Business Recovery Assessment Framework (BRAF) to help researchers and practitioners design robust, repeatable, and comparable studies of business recovery in various post‐disruption contexts. Studies assessing business recovery without adequately considering the research aims, recovery definitions, and indicators can produce misleading findings. The BRAF is composed of a series of steps that guide the decisions that researchers need to make to ensure: (i) that recovery is indeed being measured; (ii) that the indicators of recovery that are selected align with the objectives of the study and the definition of recovery; and, where necessary, (iii) that appropriate comparative control variables are in place. The paper draws on a large dataset of business surveys collected following the earthquakes in Canterbury, New Zealand, on 4 September 2010 and 22 February 2011 to demonstrate the varied conclusions that different recovery indicators can produce and to justify the need for a systematic approach to business recovery assessments.  相似文献   
152.
The perennially ice-covered, closed basin lakes in the McMurdo Dry Valleys respond rapidly to environmental changes, especially climate. For the past 15 years, the McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) program has monitored the physical, chemical and biological properties of the lakes in Taylor Valley. In order to better assess the physiochemical controls on the biological process within one of these lakes (Lake Hoare), we have used vertical profile data to estimate depth-dependent correlations between various lake properties. Our analyses reveal the following results. Primary production rates (PPR) are strongly correlated to light (PAR) at 12-15 m and to soluble reactive phosphorus (SRP) at 8-22 m. Chlorophyll-a (CHL) is also positively correlated to PAR at 14 m and greater depths, and SRP from 15 m and greater. This preliminary statistical analysis supports previous observations that both PAR and SRP play significant roles in driving plant growth in Lake Hoare. The lack of a strong relationship between bacterial production (BP) and dissolved organic carbon (DOC) is an intriguing result of the analysis.  相似文献   
153.
C. Martin  E. Ayesa 《Ecological modelling》2010,221(22):2656-2667
This paper proposes an Integrated Monte Carlo Methodology (IMCM) to solve the parameter estimation problem in water quality models. The methodology is based on Bayesian approach and Markov Chain Monte Carlo techniques and it operates by means of four modules: Markov Chain Monte Carlo (MCMC), Moving Feasible Ranges (MFR), Statistical Analysis of the Joint Posterior Distribution (SAD) and Uncertainty Propagation Analysis (UPA). The main innovation of the new proposal lies in the combination of MCMC and MFR modules which provides the joint posterior distribution of the calibrated parameters following the classical Bayesian approach. While MCMC module, based on Shuffled Complex Evolution Metropolis (SCEM-UA) algorithm, is specially designed to sample complex joint posterior shapes within certain parameter ranges, the MFR readjusts these ranges until the coverage of the feasible parameter space is guaranteed. Once the joint posterior distribution is properly defined, the SAD provides the parameter statistics and the UPA performs an analysis of the uncertainty propagation through the model. The possibilities of the new proposal have been tested on the basis of a simple model featuring different activated sludge batch experiments. IMCM has been implemented in Matlab and it is prepared to be easily connected to any software package.  相似文献   
154.
钒是一种重要的生命冗索,同时也是环境污染物之一,因此环境样品及生命有机体中微量钒的测定具有重要的实际意义,是预测和评估其对人体健康、环境发全影响的重要前提之一。环境中钒主要以Ⅳ价和V价存在,因而对钒的测定方法研究主要集中在Ⅳ和Ⅴ价化合物的分离分析上,对Ⅴ(Ⅴ)和Ⅴ(Ⅳ)的分离方法,和光谱法、催化动力法、极谱法、酶学反应法等测定Ⅴ(Ⅴ)、Ⅴ(Ⅳ)和Ⅴ的方法进行了综述。  相似文献   
155.
Retractable type fall arresters are part of the equipment used for protecting people against falls from a height. They are an intermediate part between full body harness worn by a man and the structural anchor at the worksite. The most important task of retractable type fall arresters is to arrest people’s falls and to reduce their harmful consequences. Information received from users as well as laboratories testing protective equipment indicates that the performance of such equipment is incorrect under specific conditions. The paper is concerned with an analysis of the conditions in which retractable type fall arresters demonstrate intermittent performance and with an explanation of that phenomenon. The results of tests investigating anchor devices and the performance of retractable type fall arresters are presented. External and internal factors contributing to intermittent performance have been determined and guidelines for safer use of these devices have been developed.  相似文献   
156.
157.
Improvised explosive devices (IEDs) have become an alternative method for terrorists or criminals who face difficulties in obtaining traditional explosives as threatening tools. The ease of obtaining precursor materials from commodity chemicals in the free market and the ease of generating bombs through the hands of novices have created problems. Controlling the potential precursors to defeat illegal acquisition is not trivial due to their widespread use as common merchandise among chemical industries and consumers. However, efforts to identify the potential precursors may be the first step for devising appropriate control measures. In this study, we proposed a systematic screening method for identifying potential IED precursors (IEDPs) from commodity chemicals, which are regulated by Korean controls. We identified 25 potential IEDPs from 3980 candidate chemicals that can be diverted into IEDs or homemade bombs but are not likely to be solely used as an IED. We also developed a methodology of prioritizing the potential precursor chemicals to assess the urgency of controls using a scoring system with four criteria: previous listing as an official precursor; past record of being encountered in criminal use; volume of commercial circulation, which denotes the probability of exposure to individuals; and the degree of regulatory counter-measures against illegal acquisitions that are currently effective in Korea.  相似文献   
158.
本文采用3种不同的消解方法对环境土壤标准物质ESS-2和ESS-3进行处理,火焰原子分光光度法分别测定其中铜(Cu)、锌(Zn)元素的含量.3种消解方法为:电热板消解法、微波消解法和全自动消解法.分析测定结果探讨这3种消解方法的优缺点,以期获得最经济实效的消解手段.实验证明:微波消解法操作简便快捷、赶酸时间短、无污粢、准确度高、精密度好,因此提高了工作效率.  相似文献   
159.
Hypsometry has been shown to be a useful tool in geomorphic analysis of watersheds with the use of third‐degree polynomial equations to express the hypsometric curve. Despite its usefulness with watersheds in the equilibrium stage, the third‐degree polynomial has been found to be inadequate to describe the hypsometry of Monadnock phase watersheds. Three other equations — a modified third‐degree polynomial with a rational term, a sigmoidal model, and a double exponential — were used to determine hypsometric attributes of 32 Monadnock phase watersheds and compared to the third‐degree polynomial form. The three other equations were found to be better fits for Monadnock phase watersheds than the third‐degree polynomial equation, regardless of which ratio — area or elevation — was plotted as the independent variable. Due to the occasional failure of each functional form to give logical values for hypsometric attributes, the importance of using more than one form equation is discussed. After determining the best‐fit equation for each watershed, the usefulness of hypsometric attributes is discussed in relation to erosion processes within Monadnock phase watersheds.  相似文献   
160.
燃煤电厂烟气脱硫设施脱硫效率计算方法的探讨   总被引:2,自引:0,他引:2  
为准确评估燃煤电厂脱硫设施在实际运用中的脱硫效率,根据目前脱硫效率的三种计算方法在实际运用中的问题,并应用燃煤电厂的实测数据,对比了三种方法计算得出脱硫效率的相对误差。结果表明:根据折算浓度评估脱硫效率,综合考虑了烟气泄漏对计算脱硫效率的影响,并且不受烟气旁路排放等因素影响,理论上和实践中都可以得到准确的脱硫效率。  相似文献   
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