Multiple transitions in poly(allylbenzene): 1. Thermophysical properties

Polyallylbenzene is a semicrystalline material the thermal behaviour and physical properties of which reveal several transitions. Thermal and differential calorimetric analysis have shown the influence of the history of the material about the glass transition and melting. Several techniques such as thermomechanical analysis, dilatometry and inverse gas chromatography give additional information for the unidimensional and volume behaviour of the polymer versus temperature.     

Dilute solution behavior and Mark-Houwink constants for a non-linear cationic polyelectrolyte

Mark-Houwink coefficients and radius of gyration dimensions are presented for six unfractionated cationic polyelectrolytes of the poly(dimethylamine-epichlorohydrin-ethylendiamine) type. The copolymer system was studied in .05M, .10M, and 1.0M NaCl, and .12M NaClO₄ aqueous solutions. Their solution behavior, as studied by intrinsic viscosity and light-scattering technique, suggests these polymers adopt a somewhat spherical or star-like conformation in aqueous salt solutions.     

Fracture Mechanics of cracks originating from holes treated for notch stress relieving

A tensile plate with a circular hole is investigated. The notch stresses are calculated, for an optimum notch arrangement as well as cold expansion of the notch. The stress-intensity factor is calculated for a crack originating at a single circular hole surrounded by two axially arranged circular stress-relieving notches. Furthermore, the influence of cold expansion of the main notch, which is to be relieved, and of the combination of cold expansion and stress-relieving notches on the stress intensity factor is investigated. The weight-function is given for all the cases above. It has been computed with good approximation by a Finite-Element-Method.     

26.5 GHz bandwidth InGaAsP lasers with tight optical confinement

By reducing the active-layer width of constricted-mesa lasers to 1 ?m, we have increased 20°C CW bandwidth to 16 GHz and the -60°C bandwidth to 26.5 GHz. The pulsed 20°C bandwidth is 22 GHz, indicating that the present bandwidth limitation is predominantly thermal. Optical transmission systems with bandwidths spanning the S, G, J, X, P and K microwave waveguide bands simultaneously are now possible.     

L'impact des relations interpersonnelles et familiales sur les personnes souffrant d'agoraphobie: L'état de la question.

Reviews the literature on the impact of interpersonal relationships, especially family relationships, on the development, maintenance, and behavioral treatment of agoraphobia. Interpersonal relationships seem to play some role in the agoraphobic pathology, mainly for the onset of agoraphobia and the presence of social anxiety. However, it seems that its importance is less than what has been suggested in the literature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impairment of memory for spatial context in schizophrenia.

A group of 33 patients with schizophrenia were compared with control participants using a spatial memory task in which words were presented on locations of a grid. In the first part of the experiment, recognition of target information (words) was tested. In the second, 2 tasks of spatial location (contextual information) were given involving different sets of words placed in different locations: A location memory task (determining which word was in a particular spatial location) explored an associative form of spatial memory, and a relocation task (determining where a particular word was located) explored an associative and a nonassociative form of spatial memory. Patients were more impaired with regard to the location memory task than to the target recognition and relocation tasks. The impairment was negatively correlated with Stroop task performance. The results suggest that schizophrenia is associated with a spatial context memory deficit, which could be due to defective associations between target and spatial information. This deficit seemed to be related to frontal dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Insights into potential cellular mechanisms of cisplatin nephrotoxicity and their clinical application

Cisplatin preferentially accumulates in cells of the S3 segment of the renal proximal tubule and is toxified intracellularly by hydration. The earliest manifestation of toxicity is inhibition of protein synthesis. GSH depletion is another important mechanism causing CP toxicity. Intracellular binding to SH groups leads to GSH depletion, resulting in lipid peroxidation and eventually mitochondrial damage. New measures to prevent GSH depletion and scavenge intracellular free oxygen radicals have been tried in clinical studies. Promising results indicate that cisplatin nephrotoxicity can be further reduced in the future.     

On the morphology of the modulated precipitation of extended multiplets and Fe9C4 epsilon or eta carbide obtained by aging and tempering in Fe- C martensite

The clustering of carbon atoms into isolated multiplets followed by their ordering into (100)_α’ mono-layers leads to the B2 monoclinic multilayer structure called the extended multiplet, during the low temperature aging of Fe-C martensite. The ultimate step of the process is obtained by a lC,2Fe, lC,5Fe, lC,5Fe sequence along the [001]_α′. direction giving rise to a 12 lattice parameter periodicity associated with antiphase domains, for matching the lattices of the precipitate and of the matrix. It explains the satellites observed by electron diffraction as well as the (023)_α′. habit plane revealed by the diffuse scattering streaks and TEM observations. The carbon free regions between the antiphase domains correspond to the ‘C ’ or ‘к’ phase as determined from the (200)/(020) and (002) martensite peak profile X-ray analysis. The laterin situ transformation to the ordered Fe₉C₄ ε- or η-carbide, corresponds to an orthorhombic structure with parametersα _η =3α _ε,b _η≈ 3α_ε√3, andc _η =c _ε, ifα _ε andcε are the initial parameters of the Fe hcp stacking,i.e., α _η= 8.46 to 8.49 Å,b _η = 14.04 to 14.07 Å, andc _η = 4.31 to 4.32 Å for the binary Fe-C alloys. The transformation induces plate-like carbide precipitates with a (035)(gα′). predicted habit plane, which is 4.40 deg away from the approximate (012)_ga′. plane observed by TEM.     

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