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Heidi M. Reichenbach Hongmei An Paul J. McGinn 《Applied catalysis. B, Environmental》2003,44(4):347-354
A polymerizable-complex method (PCM) was used with automated solution deposition to generate combinatorial libraries of oxide powders that were evaluated for their ability to catalyze the combustion of soot. Chemical compositions were examined for catalytic activity in the soot combustion reaction in parallel using infrared thermography and serially using automated thermogravimetric analysis. Although infrared analysis is much faster, it is not easily suited to analyzing soot combustion in the configuration employed in the present study. Instead, the slower automated thermogravimetric analysis (TGA) was found to be much more reliable and reproducible. The results of characterizing simple oxide systems (Ce–K–O, Cu–K–O, Ce–Na–O and Cu–Na–O) are reported. 相似文献
65.
Spontaneous Imbibition Experiments of Enhanced Oil Recovery with Surfactants and Complex Nano-Fluids 下载免费PDF全文
Brian F. Towler Heidi L. Lehr Scott W. Austin Brooks Bowthorpe Jacob H. Feldman Sabrina K. Forbis David Germack Mahshid Firouzi 《Journal of surfactants and detergents》2017,20(2):367-377
Two types of porous media were analyzed with the intention of exploring alternative enhanced oil recovery methods. Core samples were taken from the Tensleep Formation of the Black Mountain Field in Hot Springs County, WY. The lithology is mainly sandstone and dolomite. The measured effective porosity values ranged from 13.0 to 18.0%, and permeabilities from 19 to 68 md. Production from the Tensleep and Phosphoria formations using conventional methods has resulted in a low secondary recovery factor, possibly due to high capillary forces and an oil-wet formation. Different surfactants were investigated to determine the viability of a possible enhanced oil recovery process using a spontaneous imbibition process in Amott cells. A very high enhanced recovery factor of more than 89% was achieved using a complex nano-fluid that consists of a mixture of surfactant, solvent, co-solvent and water. These recovery factors compared with 13% by brine imbibition and up to 21% using commercial surfactants. At the other end of the scale, very high porosity volcanic pumice was also subjected to the same tests. For this rock the porosity values ranged from 65 to 90% and permeabilities were 2.0–2.7 d. Secondary recovery showed values up to 81% on spontaneous imbibition and up to 91% when surfactants were employed. These experimental results indicate that pumice has favorable reservoir characteristics, but, due to its weak brittle nature, it would not be expected that it could withstand the overburden stress at any significant depth. However, it does represent a useful laboratory specimen. 相似文献
66.
There are often multiple competing objectives for industrial scheduling and production planning problems. Two practical methods are presented to efficiently identify promising solutions from among a Pareto optimal set for multi-objective scheduling problems. Generally, multi-objective optimization problems can be solved by combining the objectives into a single objective using equivalent cost conversions, utility theory, etc., or by determination of a Pareto optimal set. Pareto optimal sets or representative subsets can be found by using a multi-objective genetic algorithm or by other means. Then, in practice, the decision maker ultimately has to select one solution from this set for system implementation. However, the Pareto optimal set is often large and cumbersome, making the post-Pareto analysis phase potentially difficult, especially as the number of objectives increase. Our research involves the post Pareto analysis phase, and two methods are presented to filter the Pareto optimal set to determine a subset of promising or desirable solutions. The first method is pruning using non-numerical objective function ranking preferences. The second approach involves pruning by using data clustering. The k-means algorithm is used to find clusters of similar solutions in the Pareto optimal set. The clustered data allows the decision maker to have just k general solutions from which to choose. These methods are general, and they are demonstrated using two multi-objective problems involving the scheduling of the bottleneck operation of a printed wiring board manufacturing line and a more general scheduling problem. 相似文献
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Richard Ashley David Blackwood David Butler Paul Jowitt John Davies Heidi Smith Daniel Gilmour Crina Oltean-Dumbrava 《Canadian Metallurgical Quarterly》2008,134(3):200-209
Effective integrated water management is a key component of the World Water Vision and the way in which aspirations for water equity may be realized. Part of the vision includes the promotion of sustainability of water systems and full accountability for their interaction with other urban systems. One major problem is that “sustainability” remains an elusive concept, although those involved with the provision of urban wastewater systems now recognize that decisions involving asset investment should use the “triple bottom line” approach to society, the economy, and the environment. The Sustainable Water Industry Asset Resource Decisions project has devised a flexible and adaptable framework of decision support processes that can be used to include the principles of sustainability more effectively. Decision mapping conducted at the outset of the project has shown that only a narrow range of criteria currently influence the outcome of asset investment decisions. This paper addresses the concepts of sustainability assessment and presents two case studies that illustrate how multicriteria decision support systems can enhance the assessment of the relative sustainability of a range of options when decisions are being made about wastewater asset investment. 相似文献
68.
Hamann Heidi A.; Smith Timothy W.; Smith Ken R.; Croyle Robert T.; Ruiz John M.; Kircher John C.; Botkin Jeffrey R. 《Canadian Metallurgical Quarterly》2008,27(1):100
Objective: The familial context plays an important role in psychosocial responses to genetic testing. The purpose of this study was to compare sibling pairs with different combinations of BRCA1/BRCA2 test results on measures of affect, interpersonal responses, and physiological reactions. Design: Forty-nine sibling dyads with different combinations of BRCA1/BRCA2 test results (i.e., mixed, positive, negative) completed a questionnaire, and 35 of the dyads also participated in a laboratory-based discussion of genetic testing. Main Outcome Measures: The primary outcome variables included participant reports of supportive actions toward their sibling, state anger and anxiety, perceptions of sibling behavior, and electrodermal responses. Results: Compared to positive and negative dyads, mixed pairs reported less friendly general support actions, noted more anger, and perceived their sibling to be less friendly and more dominant during the interactions. In comparisons between same-result (i.e., positive, negative) pairs, positive dyads reported more dominant support behaviors and perceived their sibling to be friendlier during the interactions. Conclusion: Data suggest that siblings who have different test results may experience more interpersonal strain than siblings who have the same test result. Future research on genetic testing and family relationships can expand upon these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
Characterization of Raman spectra measured in vivo for the detection of cervical dysplasia 总被引:1,自引:0,他引:1
Robichaux-Viehoever A Kanter E Shappell H Billheimer D Jones H Mahadevan-Jansen A 《Applied spectroscopy》2007,61(9):986-993
Raman spectroscopy has been shown to have the potential for providing differential diagnosis in the cervix with high sensitivity and specificity in previous studies. The research presented here further evaluates the potential of near-infrared Raman spectroscopy to detect cervical dysplasia in a clinical setting. Using a portable system, Raman spectra were collected from the cervix of 79 patients using clinically feasible integration times (5 seconds on most patients). Multiple Raman measurements were taken from colposcopically normal and abnormal areas prior to the excision of tissue. Data were processed to extract Raman spectra from measured signal, which includes fluorescence and noise. The resulting spectra were correlated with the corresponding histopathologic diagnosis to determine empirical differences between different diagnostic categories. Using histology as the gold standard, logistic regression discrimination algorithms were developed to distinguish between normal ectocervix, squamous metaplasia, and high-grade dysplasia using independent training and validation sets of data. An unbiased estimate of the accuracy of the model indicates that Raman spectroscopy can distinguish between high-grade dysplasia and benign tissue with sensitivity of 89% and specificity of 81%, while colposcopy in expert hands was able to discriminate with a sensitivity and specificity of 87% and 72%. 相似文献
70.
Doucette WJ Chard JK Fabrizius H Crouch C Petersen MR Carlsen TE Chard BK Gorder K 《Environmental science & technology》2007,41(7):2505-2509
Trichloroethylene (TCE) contaminated groundwater migrating into communities surrounding Hill Air Force Base (HAFB) in northern Utah prompted a multiyear monitoring program (2001-2003) to examine the extent of TCE uptake and transfer into edible fruits. During the initial sampling in fall 2001, TCE was detected in a small fraction of the 167 fruit and tree core samples collected from 17 private residences. Samples were analyzed using headspace gas chromatography (GC) with electron capture detection (ECD) with limited confirmation by mass spectrometry (MS) in selected ion monitoring mode. In fall 2002, over 300 samples were collected from the same general locations sampled in 2001. No TCE was found in any of the fruit or vegetable samples above the method detection limit (MDL) for the headspace GC/MS method (approximately 0.1 microg/ kg fresh weight, depending on sample size), but TCE was again detected in several fruit tree trunk core samples. The detection of TCE in fruit in 2001, but not in 2002, may have been due to improvements in the analytical procedure or changes in the environmental conditions impacting transfer to fruit. The 2003 monitoring focused on repeated sampling over several months at five locations that were selected to represent the range of exposure scenarios evaluated during the previous years. No TCE was identified in any of the fruit above the MDL during 2003, however TCE was again found in tree core samples as observed in 2001 and 2002. 相似文献