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61.
Pirooz Darabi Tingwen Li Konstantin Pougatch Martha Salcudean Dana Grecov 《Chemical engineering science》2010,65(15):4472-4483
A simplified mathematical model and numerical simulations of the governing Navier–Stokes equations are used to predict the shape evolution, rupture distance, and liquid distribution of stretching pendular liquid bridges between two equal-sized spherical solid particles. In the simplified model, the bridge shape is approximated with a parabola, and it is assumed that the surface tension effects dominate the viscous, inertial, and gravitational effects. For the numerical simulations, a commercial Computational Fluid Dynamics (CFD) software package – FLUENT – is used. The rupture distance predictions obtained with both models are compared with experimental data and a reasonable agreement is found. The results of the numerical investigations show that for simulations with negligible viscous, inertial, and gravitational effects, the rupture distance approaches an asymptotic value, which is close to the value predicted by the simplified model. The bridge profiles predicted using the simplified model and the numerical simulation are compared. It is found that a second-order polynomial appropriately represents the stable bridge shape for particles with identical contact angles; however, for liquid bridges between particles with different contact angles, the numerical simulations of the governing Navier–Stokes equations should be used. 相似文献
62.
Hernández-Ceruelos A Madrigal-Santillán E Morales-González JA Chamorro-Cevallos G Cassani-Galindo M Madrigal-Bujaidar E 《International journal of molecular sciences》2010,11(10):3793-3802
Chamomilla recutita (L.) Rauschert (Asteraceae), popularly known as chamomile, is a plant used in traditional medicine for various therapeutic purposes. Chamomile essential oil (CEO) is particularly known to inhibit the genotoxic damage produced by mutagens in mice somatic cells. The aim of this research was to determine the inhibitory potential of CEO on the genotoxic damage produced by daunorubicin (DAU) in mice germ cells. We evaluated the effect of 5, 50, and 500 mg/kg of essential oil on the rate of sister chromatid exchange (SCE) induced in spermatogonia by 10 mg/kg of the mutagen. We found no genotoxicity of CEO, but detected an inhibition of SCE after the damage induced by DAU; from the lowest to the highest dose of CEO we found an inhibition of 47.5%, 61.9%, and 93.5%, respectively. As a possible mechanism of action, the antioxidant capacity of CEO was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method and ferric thiocyanate assays. In the first test we observed a moderate scavenging potential of the oil; nevertheless, the second assay showed an antioxidant capacity similar to that observed with vitamin E. In conclusion, we found that CEO is an efficient chemoprotective agent against the damage induced by DAU in the precursor cells of the germinal line of mice, and that its antioxidant capacity may induce this effect. 相似文献
63.
Rothke Steven E.; Friedman Alan F.; Jaffe Alan M.; Greene Roger L.; Wetter Martha W.; Cole Patricia; Baker Kathryn 《Canadian Metallurgical Quarterly》2000,12(3):335
Data from several clinical samples and the Minnesota Multiphasic Personality Inventory–2 standardization group are presented to familiarize the reader with response patterns of different groups on a new validity scale designed to assist in the identification of exaggeration or fabrication of psychological disturbance. Sensitivity-specificity analyses are included along with suggestions for use of the F(p) Scale with other validity scales. Cautions about setting single cutoff scores are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
We find much of interest, and little to disagree with, in the commentaries on our article. We take issue only with the suggestion that our article was provocative and submit that the attempt to understand the use of stimulants as smart pills does not imply an endorsement of the practice. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
65.
66.
Social and metacognitive contributors to gender differences in 1st grader's mathematics strategy use were explored. Fifty-eight children solved addition and subtraction problems individually and in groups of 3 in October, January, and May. The children's strategy use was assessed individually, as well as their metacognitive knowledge for mathematics strategies and their rationales for the use of different mathematics strategies. The children also solved addition and subtraction problems in groups. Gender differences were found: Girls were more likely to count on fingers or use counters (overt strategies); boys were more likely to use retrieval (from memory) to solve addition and subtraction problems. All children were less likely to use overt strategies and more likely to use covert strategies and retrieval in the group session. Metacognition was a significant predictor of strategy use. Social rationales for strategy use emerged at the end of the year. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
67.
Zaslow Martha J.; Weinfield Nancy S.; Gallagher Megan; Hair Elizabeth C.; Ogawa John R.; Egeland Byron; Tabors Patton O.; De Temple Jeanne M. 《Canadian Metallurgical Quarterly》2006,42(1):27
This study examined predictions from preschool parenting measures to middle childhood cognitive and socioemotional child outcomes to explore whether parenting assessment methodologies that require more time, training, and expense yield better predictions of child outcomes than less intensive methodologies. Mother-child dyads (N=278) in low-income African American families were assessed when the child was in preschool, using maternal report, the Home Observation for Measurement of the Environment-Short Form (P. Baker & F. Mott, 1989; R. Bradley & B. Caldwell, 1984), and structured observational measures of parenting. Child outcomes reported by children, mothers, teachers, and direct assessment were collected 4 years later. All parenting methodologies showed some predictive value; however, observational parenting measures showed the strongest and most consistent predictions of child outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
68.
Costigan Catherine L.; Cox Martha J.; Cauce Ana Mari 《Canadian Metallurgical Quarterly》2003,17(3):397
This study evaluates the impact of work experiences on parenting quality during the transition to parenthood. Dual-earner parents (n = 83) completed measures of work experiences (autonomy and interpersonal atmosphere). Parenting was observed twice, 3 months apart. Hierarchical regression analyses showed that mothers who reported a more negative interpersonal atmosphere at work showed decreases in positive parenting and increases in negative personal parenting over time, after controlling for their occupational status and general well-being. Mothers' work experiences also predicted changes in fathers' observed parenting. In contrast, fathers' work experiences were largely unrelated to fathers' or mothers' parenting. With one exception, parents' occupational status did not moderate work-parenting relationships, and feelings of role overload did not mediate these relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
The fine structure and physical properties of bright and semidull poly(ethylene terephthalate) (PET) fibers were investigated as successive layers of the polymer were removed by hydrolysis using aqueous solutions of sodium hydroxide up to weight losses of 90 and 68%, respectively. For both types large changes in molecular weight distribution did not occur, although as weight loss increased, the density of the remaining fiber increased. Alterations in fine structure with weight loss were also observed by thermal analysis. Greater strength loss with decreasing weight occurred for the semidull fiber than for the bright sample. Larger pits formed on the surface of the hydrolyzed semidull fibers than on the surface of the bright products. This observation is attributed to the titanium oxide present in the semidull fibers. It was also noted that as the density of the bright PET samples was increased by heatsetting, the rate of hydrolysis decreased. 相似文献
70.
Developed an intimacy interview and a rating system that allowed the reliable classification of 40 25–35 yr old women in 6 intimacy statuses. The interview/rating system included 2 new statuses: committed and uncommitted merger. The intimacy status interview and rating system, the Objective Measure of Ego-Identity Status (OMEIS), and 3 subscales from the Personality Research Form (PRF) were administered to Ss. It was predicted that merger Ss would score lower than Ss in other statuses on the Autonomy and Dominance and higher on the Succorance scales of the PRF. Results show that intimacy status was related to OMEIS scores. Most (7 of 9) committed merger Ss scored as identity diffuse or foreclosed. Nine uncommitted merger Ss scored as identity diffuse or moratorium. Ss in the moratorium category had strong religious involvement. Merger Ss had significantly higher scores on the Succorance scale of the PRF. Results are discussed in the context of childhood processes of attachment and separation. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献