Influence of oxygen introduced in TiFe-based hydride forming alloy on its morphology,structural and hydrogen sorption properties

Hydrogen sorption performances of TiFe are very sensitive to the preparation conditions, especially ones which result in contamination of the material with oxygen.     

200 NL H2 hydrogen storage tank using MgH2–TiH2–C nanocomposite as H storage material

MgH₂-based hydrogen storage materials are promising candidates for solid-state hydrogen storage allowing efficient thermal management in energy systems integrating metal hydride hydrogen store with a solid oxide fuel cell (SOFC) providing dissipated heat at temperatures between 400 and 600 °C. Recently, we have shown that graphite-modified composite of TiH₂ and MgH₂ prepared by high-energy reactive ball milling in hydrogen (HRBM), demonstrates a high reversible gravimetric H storage capacity exceeding 5 wt % H, fast hydrogenation/dehydrogenation kinetics and excellent cycle stability. In present study, 0.9 MgH₂ + 0.1 TiH₂ +5 wt %C nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was prepared by HRBM preceded by a short homogenizing pre-milling in inert gas. 300 g of the composite was loaded into a storage tank accommodating an air-heated stainless steel metal hydride (MH) container equipped with transversal internal (copper) and external (aluminium) fins. Tests of the tank were carried out in a temperature range from 150 °C (H₂ absorption) to 370 °C (H₂ desorption) and showed its ability to deliver up to 185 NL H₂ corresponding to a reversible H storage capacity of the MH material of appr. 5 wt% H. No significant deterioration of the reversible H storage capacity was observed during 20 heating/cooling H₂ discharge/charge cycles. It was found that H₂ desorption performance can be tailored by selecting appropriate thermal management conditions and an optimal operational regime has been proposed.     

The relation of congitive-dissonance theory to an aspect of psychotherapeutic practice.

"The present paper is designed to link dissonance theory with one practical reality-oriented aspect of the process of psychotherapy with emotionally troubled individuals—namely, the charging of fees." Freud stated that "money matters are treated by civilized people in the same way as sexual matters—with the same inconsistency, prudishness, and hypocrisy. It is… avowed… that in order to accomplish any significant therapeutic work the patient must be charged a fee that is somewhat painful and discomforting." Dissonance theory "would predict that if a person paid nothing for something that he believed was worth nothing he would not experience cognitive dissonance. Rather his cognitive world would be in a state of harmony in this regard. My main purpose has been to stimulate greater clinical interest in the possibilities of employing general psychological theories, developed in the more traditional academic areas of psychology, to shed light upon seemingly complex issues in the field of clinical psychology." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent developments in the buckling and nonlinear analysis of thin-walled structural members

This paper describes recent work performed at the University of Sydney to develop buckling and nonlinear analyses of thin-walled structural members undergoing local, distortional and overall buckling. The analyses are based on the finite strip method of structural analysis and include elastic and inelastic buckling and the full nonlinear response with both post-local buckling and plasticity. Two variations of the finite strip method have been used, these being the semi-analytical and spline finite strip methods. A nonlinear beam-column analysis based on the influence coefficient method for including the local buckling behaviour in the overall member response is also described.

The analytical methods are compared with tests performed at the University of Sydney on cold-formed rectangular hollow sections, welded I-sections, welded channel sections and cold-formed channel sections. Spatial plastic collapse mechanismsdeveloped for the welded sections described above are also compared with the post-ultimate response of the test sections.     

Utility of the Rorschach in predicting movement in psychiatric casework.

50 women were administered psychological tests at the time their children were institutionalized for emotional disturbances. Utilizing objective Rorschach signs, psychologists predicted which women would show movement in psychiatric casework. Highly significant agreement was found between the predictions and the actual outcomes of casework based on Hunt-Kogan ratings of movement following at least 1 yr. of casework. It was concluded that this method of using Rorschach data possesses considerable research utility, and that further investigation with these procedures may eventually contribute to increased efficiency in use of clinical facilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Uptake of mercury by thiol-grafted chitosan gel beads

This study describes the synthesis and characterization of thiol-grafted chitosan beads for use as mercury (Hg) adsorbents. Chitosan flakes were dissolved and formed into spherical beads using a phase inversion technique, then crosslinked to improve their porosity and chemical stability. Cysteine was grafted onto the beads in order to improve the adsorption affinity of Hg to the beads. The beads possessed an average diameter of 3.2 mm, porosity of 0.9, specific surface area of approximately 100 m2/g, average pore size of approximately 120 angstroms, and specific gravity of 2.0. Equilibrium and kinetic uptake experiments were conducted to study the uptake of Hg by the beads. The adsorption capacity was approximately 8.0 mmol-Hg/g-dry beads at pH 7, and decreased with decreasing pH. Hg adsorption kinetics was modeled as radial pore diffusion into a spherical bead with nonlinear adsorption. Use of the nonlinear Freundlich isotherm in the diffusion equation allowed modeling of the uptake kinetics with a single tortuosity factor of 1.5 +/- 0.3 as the fitting parameter for all initial Hg concentrations, chitosan loadings, and agitation rates. At agitation rates of 50 and 75 rpm, where uptake rate was reduced significantly due to the boundary layer effect, the mass transfer coefficient at the outside boundary was also used as a fitting parameter to model the kinetic data. At agitation rates higher than 150 rpm, pore diffusion was the rate-limiting step. The beads exhibited a high initial uptake rate followed by a slower uptake rate suggesting pore diffusion as the rate-determining step especially at high agitation rates. Higher uptake rates observed in this study compared to those in a previous study of chitosan-based crab shells indicate that dissolution and gel formation increase the porosity and pore accessibility of chitosan.     

3D Finite Element Study on Load Transfer at Doweled Joints in Flat and Curled Rigid Pavements

This study examines load transfer across doweled joints in rigid pavements using 3D finite element analysis. A recently developed dowel modeling strategy is employed that allows the efficient and rigorous consideration of dowel/slab interaction. Parametric studies on the response of a typical, dowel‐retrofitted pavement system subjected to axle loads and varying degrees of slab curling are conducted. To examine the effect of slab support on pavement response, the studies consider two different foundation types: layered elastic with an asphalt‐treated base and a dense liquid foundation. The results of the studies are discussed with emphasis on the effect of slab curling and foundation type on joint load transfer and the potential for joint distress. While there are significant differences in response for the ATB‐supported slabs and the slabs founded on a dense liquid, slab curling does generally increase dowel shears and dowel/slab bearing stresses. However, further examination of the parametric study results that accounts for compressive fatigue of the concrete at the dowel/slab interface indicates that slab curling may not significantly increase the potential for damage to the slab concrete surrounding the dowels.     

Multigrid Preconditioner for Unstructured Nonlinear 3D FE Models

Multigrid and multigrid-preconditioned conjugate-gradient solution techniques applicable for unstructured 3D finite-element models that may involve sharp discontinuities in material properties, multiple element types, and contact nonlinearities are developed. Their development is driven by the desire to efficiently solve models of rigid pavement systems that require explicit modeling of spatially varying and discontinuous material properties, bending elements meshed with solid elements, and separation between the slab and subgrade. General definitions for restriction and interpolation operators applicable to models composed of multiple, displacement-based isoparametric finite-element types are proposed. Related operations are used to generate coarse mesh element properties at integration points, allowing coarse-level coefficient matrices to be computed by a simple assembly of element stiffness matrices. The proposed strategy is shown to be effective on problems involving spatially varying material properties, even in the presence of large variations within coarse mesh elements. Techniques for solving problems with nodal contact nonlinearities using the proposed multigrid methods are also described. The performance of the multigrid methods is assessed for model problems incorporating irregular meshes and spatially varying material properties, and for a model of two rigid pavement slabs subjected to thermal and axle loading that incorporates nodal contact conditions and both solid and bending elements.     

THE MEANING AND CLINICAL VALIDITY OF THE TAYLOR ANXIETY SCALE AND THE HYSTERIA-PSYCHASTHENIA SCALES FROM THE MMPI.

The authors attempt to determine the meaning of the psychasthenia, anxiety, and composite hysteria-psychasthenia scales in terms of related personality traits as assessed by other techniques and to examine further the intercorrelations among these scales. Findings suggest caution in ascribing performance differences between high- and low-anxiety groups, measured by the Taylor scale, as being solely due to the drive properties of anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rorschach and TAT indices of homosexuality in overt homosexuals, neurotics, and normal males.

Rorschach and TAT protocols of 20 male overt homosexuals, 20 male neurotics, and 20 normal male students were compared in order to determine whether proposed homosexual signs were discriminative. The homosexual group gave a significantly greater mean number of the Rorschach and TAT signs than did either nonhomosexual group. "Within the homosexual group, correlation between the number of Rorschach signs and number of TAT signs produced by each S proved significant, serving as a check on the validity of both schemes and indicating the consistency of these 2 diverse measures of homosexuality." (PsycINFO Database Record (c) 2010 APA, all rights reserved)