Sibling relationship, family, and genetic factors in sibling similarity in sexual risk.

Siblings’ risky attitudes toward sex and pregnancy and risky sexual behavior were studied in 1583 dyads from the National Longitudinal Study of Adolescent Health. We tested moderators of the links between 2 siblings’ reports of sexual risk as well as mediators of the links between siblings’ genetic similarity and similarity in their sexual risk. Siblings’ sexual risk reports were correlated, and consistent with social learning predictions, associations were stronger between siblings with close relationships and in same-gender dyads and, to a lesser extent, between more genetically similar siblings and those closer in age. Consistent with behavior genetics’ hypotheses about gene–environment correlations, similarity in family warmth and sibling relationship closeness mediated associations between siblings’ genetic similarity and similarity in their sexual risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

汉方，健康秀发之源

想要拥有一头健康有光泽的秀发是许多人的梦想，然而因为受到空气污染、生活与工作环境的多重压力，以及不良饮食习惯等因素，大多数的人其实无法拥有非常健康的发质。     

Application of a method for the mathematical experimental statistical modeling approach to analyze physical–chemical properties of interpenetrating polymer network of polyurethane and unsaturated polyester

Modern statistical analysis methods were employed to investigate and evaluate the effect of chemical composition on mechanical properties of interpenetrating polymer network (IPN) formulations that had been synthesized of polyurethane and unsaturated polyester resin (cross‐linked with styrene). Experiments run according to the mathematical plan made a basis for empirical models derived from the Sheffe polynomials. The models were utilized to optimize the chemical composition of IPN from the viewpoint of achievable mechanical parameters, to assess changes of those properties over the whole theoretically possible scope of quantitative compositions, and to investigate the effects of individual components and their possible interactions. The findings supported a thesis on complex interactions between polymeric components of IPN; they can be the reason for tangled polyurethane, unsaturated polyester, and linear polystyrene polymer networks, and ultimately they can be responsible for the formation of immiscible phases within the plastics produced. Data were also obtained which make it possible to evaluate potential mechanical properties of synthesized IPN compounds as coating materials and engineering plastics. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1855–1867, 2005     

The swelling behavior of interpenetrating polymer networks composed of polyurethane and unsaturated polyester

The kinetics of swelling and the sorption performance were observed for the polymer compositions with interpenetrating polymer networks made up of polyurethane and unsaturated polyester during their exposure to chlorobenzene at 25°C. It was found that the rates for solvent transport and solvent absorption processes were controlled by the chemical composition of the formulation studied. On the basis of the observed swelling process, parameters could be assessed which were specific for the mass transfer process, i.e., diffusion coefficient, sorption coefficient, and permeability coefficient. Moreover, an attempt was made to evaluate structural parameters that describe topology of the obtained networks. It was found that the increasing share of polyurethane in the composition reduced crosslinking density in the polyester network that resulted in faster diffusion of the solvent and higher sorption capacity for the solvent. The higher the styrene content in the composition, the higher the crosslinking density in the system, and hence the diffusion of solvent and its sorption inside the polymer network was much more difficult. In the scanning electron microscope analysis of samples, which had been subjected to swelling, no leaching was observed for any phase present in the system, despite phase separation for both the components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3511–3519, 2006     

DEM simulation of the packing structure and wall load in a 2-dimensional silo

The filling and discharge of a two-dimensional wedged-bottom silo holding circular objects was modelled using DEM technique to examine the influence of method of silo filling on distribution of orientations of unit vectors normal to contact points (contact normals) and normal contact forces. It was found that packing structure determined through method of generation of grain bedding significantly influenced distribution of contact normals. Nearly hexagonal network of contact normals was obtained for central filling of silo while sprinkle filling provided higher anisotropy of contact normals. The significance of frictional conditions and number of particles in system on distribution of contact normals was analysed. Increase in number of grains reduced disturbance from boundaries on behaviour of assembly. Distribution of loads on silo bottom obtained in simulation for different wall roughness was found in qualitative agreement with experimental data.     

Teaching elementary school students to identify story themes.

An instructional program focused on story theme was administered to 2nd and 3rd graders (high-, average-, and low-achieving students, including some with disabilities) in a high-poverty school. Compared with more traditional instruction, the program improved theme comprehension and the identification of instructed themes when they appeared in new stories. However, the program did not help students apply a theme to real-life situations or identify and apply noninstructed themes. Findings indicated that at-risk children (at all achievement levels, including those with disabilities) were able to achieve some degree of abstract, higher order comprehension when given instruction that combined structured lessons, a strategy, and discussion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationships between post-failure state and compression strength of sudetic fractured rocks

The behaviour of the Sudetic crystalline rocks in a pre- and a post-critical state of stress is the topic of this work. The pre-and post-critical failure energy ratio has been discussed, and the regression lines of residual strength of fractured rocks has been detrmined, based on which the residual strength (R_rez) and the standard compression strength (R_e) relationship was empirically determined as R_rez=0.18R_c+5.6;     

Effect of fabrication temperature on strain‐sensing capacity of polypyrrole‐coated conductive fabrics

Textile strain sensors were made from polypyrrole‐coated stretchable fabrics by a method of screen printing with chemical vapor deposition. The effect of polymerization temperature on the sensing performances was studied. It was found that polymerization at low temperature significantly improved the electrical conductivity, strain sensitivity and environmental stability of the fabric sensors. The conductive fabrics were characterized using X‐ray diffraction, thermogravimetry, contact angle measurements, particle size analysis, scanning electron microscopy and scanning probe microscopy. Powders of pure polypyrrole prepared by the same fabrication method were characterized for a better understanding of the polypyrrole coating. Copyright © 2007 Society of Chemical Industry     

Search for optimal geometry of a conical turbine agitator for heat transfer in stirred vessels

Simultaneous measurements of power consumption P and heat transfer coefficient α for a jacketed, baffled, agitated vessel of diameter D = 0.45 m, equipped with a conical turbine, were carried out. The following geometric parameters of the agitator were tested: diameter d, blade width b and number Z, and distance from the bottom of the vessel to the lower edge of the blade h. The results of these investigations were generalized mathematically. On the basis of optimization, the best geometric parameters with respect to heat transfer are proposed for the conical turbine agitator.