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741.
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743.
Mohammad Sadegh Taskhiri Anthony S.F. Chiu 《Resources, Conservation and Recycling》2011,55(7):730-737
The establishment of an eco-industrial park (EIP) provides opportunity for individual plants to cooperate with each other in order to utilize resources efficiently and thus reduce waste. The goal of an EIP is to “close the loop” through recycling and reuse of material and energy streams. Studies show with current freshwater consumption trends there would be water stress aggravated by global warming in the near future. This paper presents a model to design an EIP water reuse network that considers overall system sustainability as measured with emergy, as well as cost saving desired by individual plants. Case studies from literature are then solved to illustrate the advantage of this method in decision making. The illustrative examples show how the model achieves a compromise among the potentially conflicting fuzzy goals of the various EIP stakeholders. 相似文献
744.
In this paper, we consider design-based estimation using ranked set sampling (RSS) in finite populations. We first derive
the first and second-order inclusion probabilities for an RSS design and present two Horvitz–Thompson type estimators using
these inclusion probabilities. We also develop an alternate Hansen–Hurwitz type estimator and investigate its properties.
In particular, we show that this alternate estimator always outperforms the usual Hansen–Hurwitz type estimator in the simple
random sampling with replacement design with comparable sample size. We also develop formulae for ratio estimator for all
three developed estimators. The theoretical results are augmented by numerical and simulation studies as well as a case study
using a well known data set. These show that RSS design can yield a substantial improvement in efficiency over the usual simple
random sampling design in finite populations. 相似文献
745.
Syed Ali-Musstjab-Akber-Shah Eqani Riffat Naseem Malik Ashiq Mohammad 《Environmental geochemistry and health》2011,33(1):33-47
Organochlorine pesticides (OCPs), viz. β-hexachlorocyclohexane (β-HCH), γ-HCH, aldrin, dieldrin, endrin, heptachlor, endosulfan-I,
endosulfan-II, heptachlor endoepoxide, heptachlor exoepoxide, mirex, dicofol, o,p′-dichlorodiphenyltrichloroethane (o,p′-DDT), p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyltrichloroethylene (DDE) and 12 other physicochemical parameters
were measured in surface sediments from River Chenab during two sampling seasons (summer and winter, 2007) to evaluate spatial
and temporal trends of sediment pollution. Hierarchical agglomerative cluster analysis identified three groups of sites based
on spatial similarities in physicochemical parameters and OCP residual concentrations. Spatial discriminant function analysis
(DFA) segregated 14 parameters, viz. dicofol, endosulfan-I, heptachlor endoepoxide, dieldrin, DDD, DDE, endosulfan-II, o,p′-DDT, p,p′-DDT, pH, electrical conductivity (EC), Cl−1, total P (%), and silt, which explained 96% of total variance between spatial groups. γ-HCH was the most frequently detected
(63%) pesticide, followed by DDD (56%). The ratio of DDTs to their metabolites indicated current input and anaerobic biodegradation.
Temporal DFA highlighted aldrin, heptachlor endoepoxide, Cl−1, total P, and EC as important variables which caused variations between summer and winter. DDTs were relatively more prevalent
as compared to other OCPs in the sediments samples during both seasons. DDT metabolites were detected at greater frequencies
and concentrations in winter, whereas DDT isomers were more prevalent in summer sediment samples. Factor analysis identified
agricultural and industrial activities as major sources of sediment OCP contamination. Concentrations of γ-HCH, heptachlor
endoepoxide, dieldrin, and DDTs (isomers and metabolites) in all sediment samples were well above interim sediment quality
guidelines (ISQGs) and probable effect limits (PEL) given by Canadian Sediment Quality Guidelines (CSQGs). 相似文献
746.
Aminul Islam Mohammad Asaduddin Laskar Akil Ahmad 《Environmental monitoring and assessment》2011,175(1-4):201-212
A selective method has been developed for the determination of trace amount of metal ions after preconcentration on 1-(2-pyridylazo)-2-naphthol loaded Amberlite XAD-4 resin. The chelating resin was characterized on the basis of infra red spectra, thermal and chemical stability, and hydrogen ion capacity. High preconcentration factor of 160?C400 up to a low preconcentration limit of 10 ??g L???1 has been achieved for almost all the metals. The chelating resin was highly selective even in the presence of large concentrations of alkali and alkaline earth metals and various matrix components. Chromatographic separation of metal ions in binary mixtures has been accomplished. The analytical utility of the resin for metal ions was explored by analyzing natural water and standard reference materials. 相似文献
747.
Mohammad Shahidul Islam James S. Bonner Temitope O. Ojo Cheryl Page 《Environmental monitoring and assessment》2011,175(1-4):349-366
Corpus Christi Bay (TX, USA) is a shallow wind-driven bay and thereby, can be characterized as a highly pulsed system. It cycles through various episodic events such as hypoxia, water column stratification, sediment resuspension, flooding, etc. Understanding of the processes that control these events requires an efficient observation system that can measure various hydrodynamic and water quality parameters at the multitude of spatial and temporal scales of interest. As part of our effort to implement an efficient observation system for Corpus Christi Bay, a mobile monitoring system was developed that can acquire and visualize data measured by various submersible sensors on an undulating tow-body deployed behind a research vessel. Along with this system, we have installed a downward-looking Acoustic Doppler Current Profiler to measure the vertical profile of water currents. Real-time display of each measured parameter intensity (measured value relative to a pre-set peak value) guides in selecting the transect route to capture the event of interest. In addition, large synchronized datasets measured by this system provide an opportunity to understand the processes that control various episodic events in the bay. To illustrate the capability of this system, datasets from two research cruises are presented in this paper that help to clarify processes inducing an inverse estuary condition at the mouth of the ship channel and hypoxia at the bottom of the bay. These measured datasets can also be used to drive numerical models to understand various environmental phenomena that control the water quality of the bay. 相似文献
748.
Riffat Naseem Malik Sidra Rauf Ashiq Mohammad Syed-Ali-Musstjab-Akber Shah Eqani Karam Ahad 《Environmental monitoring and assessment》2011,173(1-4):325-341
In this study, residual concentration of organochlorine pesticides (OCPs) in the sediments, prey, and eggs of Bubulcus ibis were measured from three breeding heronries from the Punjab province of Pakistan. Pattern of contamination in eggs followed the order: DDTs > HCHs > heptachlor > aldrin. Overall, pesticide residual concentrations were greater in eggs of cattle egrets collected from heronry on the River Ravi. Among HCHs, ??-HCH was more prevalent in eggs, whereas DDTs followed the order: DDD > DDE > p,p ??-DDT > o,p ??-DDT. Eggshell thinning was detected which showed negative relationship with residual concentration of DDE. In prey samples, residual concentration of POPs followed the order: DDTs > HCHs > dicofol > heptachlor; however, contamination pattern in sediments followed a slightly different order: DDTs > heptachlor > dicofol > HCHs > dieldrin > aldrin. Concentration of ??-HCH was more prevalent in sediments and comparatively greater concentrations of POPs were measured in sediments collected from the River Ravi. Dicofol was found for the very first time in the biological samples from Pakistan, and its concentration was measured as relatively high in eggs from heronry from the River Chenab. Residual concentrations measured in eggs were below the levels that could affect egret populations. Biomagnification of the total OCPs through the food chain was evident in three breeding heronries. The concentration of DDE measured in eggs of the cattle egret suggests the need for monitoring this contaminant in other bird species at different trophic levels. 相似文献
749.
Mohammad Dadashzadeh Faisal Khan Kelly Hawboldt Rouzbeh Abbassi 《Process Safety and Environmental Protection》2011,89(5):295-299
Fugitive emission rate quantification in an oil and gas facility is an important step of risk management. There are several studies conducted by the United States Environmental Protection Agency (USEPA) and American Petroleum Institute (API) proposing methods of estimating emission rates and factors. Four major approaches of estimating these emissions, in the order of their accuracy, are: average emission factor approach, screening ranges emission factor approach, USEPA correlation equation approach, and unit-specific correlation equation approach. The focus of this study is to optimize the USEPA correlation equations to estimate the emission rate of different units in an oil and gas facility. In the developed methodology, the data available from USEPA (1995) is used to develop new sets of equations. A comparison between USEPA correlation equations and the proposed equations is performed to define the optimum sets of equations. It is observed that for pumps, flanges, open-ended lines, and others, the proposed developed equations provide a better estimation of emission rate, whereas for other sources, USEPA equations supply the better estimate of emission rate. 相似文献
750.