Unperturbed dimensions of atactic poly（dibenzyl itaconate）s

The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference.     

Experimental study and numerical simulation of the sludge concentration in a sedimentation tank

Sedimentation tanks and clarifiers play a significant role in an active sludge system, and the efficiency of the whole system is closely related with the design and operation of the sedimentation tanks. This paper focuses on the sludge concentration in each cross-section of the sedimentation tank. We measured the sludge concentration to explore its distribution inside the tank, carried in-situ tests to research the fluid pattern and real operational rules of the sedimentation tank. We also used the computational fluid dynamics (CFD) software, PHOENICS 3.5, to simulate the solid-liquid two-phase fluid inside the tank and describe the sludge concentration distribution. The numerical results indicate obviously a sludge-water interface and a compression interface inside the sedimentation tank, a stratified sedimentary region with uniform concentration and a compression region with high concentration at the bottom of the tank. Although the simulated concentrations deviated slightly from those of in-situ tests, they were still acceptable for identifying the sludge interfaces and fluid pattern inside a sedimentation tank, which are important parameters for optimizing the tank size and improving the settling efficiency.     

Racial identity and academic attainment among African American adolescents

In this study, the relationships between racial identity and academic outcomes for African American adolescents were explored. In examining race beliefs, the study differentiated among (a) importance of race (centrality), (b) group affect (private regard), and (c) perceptions of societal beliefs (public regard) among 606 African American 17-year-old adolescents. Using cluster analysis, profiles of racial identity variables were created, and these profile groups were related to educational beliefs, performance, and later attainment (high school completion and college attendance). Results indicated cluster differences across study outcomes. Also, the relationships between academic attitudes and academic attainment differed across groups. Finally, the paper includes a discussion on the need to consider variation in how minority youth think about group membership in better understanding their academic development.     

When parents are deaf versus hard of hearing: patterns of sign use and school placement of deaf and hard-of-hearing children

This paper investigates the importance of knowing whether or not deaf and hard-of-hearing students have one or more deaf or hard-of-hearing parents. As noted by Mitchell and Karchmer (2004), deaf and hard-of-hearing school-age children and youth in the United States with at least one parent identified as "hearing impaired" are nearly evenly split between having at least one deaf parent and having at least one hard-of-hearing parent. However, there is no literature on the importance, if any, of this distinction. Findings from the investigation reported herein suggest that the distinction between having a deaf versus a hard-of-hearing parent is quite substantial, particularly as it pertains to the use of signing in the home. Further, signing in the home, which is reliably predicted by parental hearing status, is a significant predictor of the school setting in which the student is currently placed and the instructional use of signing in the classroom. Limitations related to the available measure of parental hearing status are discussed.     

Maternal intrusiveness, maternal warmth, and mother-toddler relationship outcomes: variations across low-income ethnic and acculturation groups

The present study investigated the extent to which maternal intrusiveness and warmth during play, observed in 579 European American, 412 African American, and 110 more and 131 less acculturated Mexican American low-income families when children were approximately 15 months old, predicted 3 dimensions of the mother-toddler relationship 10 months later. Intrusiveness predicted increases in later child negativity in all 4 groups. Among African Americans only, this association was moderated by maternal warmth. Intrusiveness predicted negative change in child engagement with mothers only in European American families. Finally, near-significant trends suggested that intrusiveness predicted later decreased dyadic mutuality in European American and more acculturated Mexican American families, but not in African American or less acculturated Mexican American families.     

Progress report on the development of child abuse prevention, identification, and treatment systems in Eastern Europe

PROBLEM: After the Soviet Union dissolved in 1989, it became apparent that there was little recognition of the problems of child abuse and neglect, professionally, legally, or societally. There were no effective systems or laws in place to deal with these problems. METHOD: Beginning in 1995 the Children's Mental Health Alliance, in conjunction with the Open Society Institute began conducting trainings in Eastern Europe [Journal of the American Academy of Child Adolescent Psychiatry 39 (2000) 660]. Originally 18 countries from the Baltics to the Balkans participated. A program was elaborated which would proceed in several stages: (1) training mental health professionals to deal with child abuse and neglect (CAN); (2) teaching multidisciplinary team work and fostering the development of multidisciplinary NGOs focused on CAN; (3) promoting the self-sufficiency of these NGO's which would then facilitate social and legal reform and increase public awareness of the problem. Specific methods included multi-national trainings, assignment of mentors to the developing teams who maintained weekly contact with the teams and made yearly site visits to their countries, and overseeing project grants from OSI. RESULTS: NGO's had been established and registered in 11 countries, many establishing a network of programs within their countries. By 2000, over 3800 mental health professional had been trained, either directly by the program or by the trainees of the program. By the end of 2000, over 17,000 other professionals (lawyers, police, judges, educators, other physicians, etc.) had been trained by the network. CONCLUSION: While more work needs to be in this region, the teams in 11 countries have made solid starts.     

Effect of Foam Cladding for Blast Mitigation： Numerical Simulation

Two numerical simulations were performed to investigate the protective effect of the foam cladding. One simulation is based on a previous experimental study, which is a ballistic pendulum with and without a foam cladding subjected to close-range blast loading. The other model is a steel beam with and without a foam cladding under blast loading. The overpressure due to the blast event can be calculated by the empirical function ConWep or by an arbitrary Lagrangian-Eulerian （ALE） coupling model. The first approach is relatively simple and widely used. The second approach can model the propagation of the blast wave in the air and the interaction between the air and the solid. It is found that the pendulum with the foam cladding always swings to a larger rotation angel compared to a bare pendulum. However, the steel beam with an appropriate foam cladding has a smaller deflection compared to the bare beam without a foam cladding. It is concluded that the protective effect of the foam cladding depends on the properties of the foam and the protected structure.     

Potential Effect of <Emphasis Type="Italic">Bacopa monnieri</Emphasis> on Nitrobenzene Induced Liver Damage in Rats

The study was designed to evaluate the hepatoprotective activity of ethanolic extract of Bacopa monnieri in acute experimental liver injury induced by Nitrobenzene in rats. The extract at the dose of 200 mg/kg body weight was administered orally once every day for 10 days. The increased serum marker enzymes, Aspartate transaminase, Alanine transaminase and alkaline phosphatase were restored towards normalization significantly by the extract. Significant increase in SOD, CAT and GPx was observed in extract treated liver injured experimental rats. Histopathological examination of the liver tissues supported the hepatoprotection. It is concluded that the ethanolic extract of Bacopa monieri plant possess good hepatoprotective activity.