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171.
Considers that although the social status of occupations has remained stable over the past 4 decades, much information about occupational prestige has been derived from studies that assume a masculine context. 102 women's caucus members, 107 female secretarial and clerical workers, 110 female undergraduates, and 78 nonworking women (mean ages = 28.4, 30.2, 21.1, and 29.5, respectively; mean yrs of college education = 3, 1.5, 3, and 2, respectively) ranked 25 occupations by prestige and perceived suitability for women. The various groups agreed on the prestige accorded to various occupations. However, the same groups showed clear differences when asked whether the occupations were appropriate for women: women's caucus members were most likely to rate an occupation as appropriate for women, followed by undergraduates, secretarial employees, and nonworking women. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
172.
We develop a new efficient numerical methodology for automated simultaneous registration and intensity correction of images. The approach separates the intensity correction term from the images being registered in a regularized expression. Our formulation is consistent with the existing non-parametric image registration techniques, however, an extra additive intensity correction term is carried throughout. An objective functional is formed for which the corresponding Hessian and Jacobian is computed and employed in a multi-level Gauss–Newton minimization approach. In this paper, our experiments are based on elastic regularization on the transformation and total variation on the intensity correction. Validations on dynamic contrast enhanced MR abdominal images for both real and simulated data verified the efficacy of the model.  相似文献   
173.
The concentrations of total, colloidal, and truly dissolved lead (Pb) were investigated in tap water following laboratory simulations of partial lead pipe replacements. Old lead pipes were recovered from service in New Orleans, La and mounted horizontally in an experimental apparatus at Tulane Univ. Municipal water was diverted for two weeks at low flowrates of 0.2 or 1.1?L/min (0.05 or 0.3?gal/min) through two pipe trains operated continuously and two pipe trains operated intermittently. Samples were collected to determine relative concentrations and time needed for each form of Pb (total, colloidal, and truly dissolved) to stabilize below the U.S. Environmental Protection Agency action level (AL) of 15?μg/L Pb. Results demonstrate that total Pb concentrations exceeded the AL immediately following simulated partial pipe replacements. In most cases, total Pb concentrations were reduced below the AL by flushing for 15–30?min but subsequent sampling revealed total Pb concentrations greater than the AL. Continuous flow pattern flushing was more effective at stabilizing total Pb concentrations below the AL than intermittent flows. Results also demonstrate that colloidal Pb concentrations were 38–54% of total Pb and truly dissolved Pb concentrations were 41–60% of total Pb concentrations after stabilization.  相似文献   
174.
Mercury intrusion porosimetry is a widely used technique for characterization of the pore size distribution of cement-based materials. However, the technique has several limitations, among which are the ink bottle effect and a cylindrical pore geometry assumption that lead to inaccurate pore size distribution curves. By substituting Wood’s metal for mercury as the intruding liquid, scanning electron microscopy and imaging techniques can be applied to the sample after intrusion. The molten Wood’s metal solidifies within the pore structure of the sample, which allows it to be sectioned and observed in the scanning electron microscopy. From here, the sample can be analyzed both qualitatively, by observing the changes in the appearance of the sample as the intrusion process progresses, and quantitatively, by applying image analysis techniques. This study provides insight for better interpretation of mercury intrusion porosimetry results and the possibility for quantitative characterization of the spatial geometry of pores in cement-based materials.  相似文献   
175.
OVERVIEW: Supercritical water is a great medium in which to perform chemical reactions and to develop processes. Due to its unique thermo‐physico‐chemical properties, supercritical water is able to play the role of solvent of organic compounds and/or to react with them. These specific properties have been used since the 1990s to develop new technologies dedicated to the environment and energy. IMPACT: Supercritical water based technologies are innovative and efficient processes having a strong impact on society, the environment and the economy, and is termed a sustainable technology. APPLICATIONS: Three main applications for supercritical water technology are under development: (i) supercritical water oxidation (SCWO); (ii) supercritical water biomass gasification (SCBG); and (iii) hydrolysis of polymers in supercritical water (HPSCW) for composites/plastics recycling. In this paper some fundamentals of supercritical water are first presented to introduce the above three major developments. Then these technologies are reviewed in terms of their present and future industrial development and their impact on the environment and on energy production. Copyright © 2010 Society of Chemical Industry  相似文献   
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It is well known that acidity, pH, of a solution accelerates the hydrolysis of soluble amides. Here we describe the unexpected result that weak small organic acids at low concentrations hydrolyze a polyamide at rates approximately twice that of a water HCl solution of the same pH. The effect of three small organic acids in dilute solutions, acetic, propanoic, and butanoic was studied. It is observed that the effect on the hydrolysis rate increases as the organic acid gets weaker. Butanoic, the weakest acid, has the strongest effect on increasing the hydrolysis rate. Measurements on the concentration of these acids in the polyamide reveal that there is a selective desire for these weak organic acids to diffuse into the polyamide. The concentration of these acids in the polyamide is found to be several multiples of the concentration in the water environment. And the acid concentration is highest for butanoic. The hydrolysis rate is shown to be governed by solubility, not pH of the water environment. The longer hydrocarbon tail on the carboxylic group increases its compatibility with the polyamide's monomer structure. Results are reported on the hydrolysis of polyamide-11 polymerized from aminoundecanoic acid, both neat and a commercial plasticized composition, placed in water at 100 °C and 120 °C under anaerobic conditions in high pressure glass tubes.  相似文献   
179.
The emergence of multidrug‐resistant bacteria and pathogens has created an urgent need for the development of new antibiotics. Herein we report our investigations into the broad‐spectrum activity of an easily prepared water‐soluble polyaminosterol compound, namely claramine A1, against both drug‐sensitive and drug‐resistant Gram‐negative and Gram‐positive bacterial strains. We also report its peculiar mechanism of action, which differs from that of all the other well‐known classes of antibiotics, toward Gram‐negative and Gram‐positive bacteria. Given their low cytotoxicity, this class of compounds based on claramine A1 could constitute an effective response to combat the emergence of multidrug‐resistant bacteria and nosocomial diseases.  相似文献   
180.
Early studies indicated that teachers’ enacted beliefs, particularly in terms of classroom technology practices, often did not align with their espoused beliefs. Researchers concluded this was due, at least in part, to a variety of external barriers that prevented teachers from using technology in ways that aligned more closely with their beliefs. However, many of these barriers (access, support, etc.) have since been eliminated in the majority of schools. This multiple case-study research was designed to revisit the question, “How do the pedagogical beliefs and classroom technology practices of teachers, recognized for their technology uses, align?”  相似文献   
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