Outcome of different treatment mixes in a multidimensional neuropsychological rehabilitation program.

Within a clinical demonstration program, 59 traumatically brain-injured patients were treated with 1 of 3 mixes of treatment. Mix 1 included cognitive remediation (CGR), small-group interpersonal (SGI) communication training, therapeutic community activities, and personal counseling. Mix 2 was similar to Mix 1 but stressed SGI exercises and eliminated CGR. Mix 3 emphasized CGR and eliminated SGI exercises. The efficacy of the treatment mixes was evaluated with performance on neuropsychological tests, improved independence in functional activities, measures of intra- and interpersonal functioning, and vocational outcome. Ss' participation in the program, irrespective of treatment mix, yielded improvements in (1) self-image, (2) quality of interpersonal relatedness and interaction, (3) involvement with others in naturalistic settings, and (4) vocational outcome. Overall, data point to the superiority of the balanced mix (Mix 1) over Mixes 2 and 3. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multi-criteria Decision-making Approach for Environmental Impact Assessment to Reduce the Adverse Effects Of Dams

Water Resources Management - Environmental Impact Assessments (EIAs) of development projects are necessary to minimize negative impacts and maximize benefits. The objective of this paper is to...     

Effect of silicides on tensile properties and fracture of alloy Ti-6AI-5Zr-0.5Mo-0.25Si from 300 to 823 K

The tensile properties and fracture behaviour of alloy Ti-6AI-5Zr-0.5Mo-0.25Si (wt%) have been investigated over a wide range of temperature from 300 to 823 K, in the as-water-quenched (WQ) and different aged (473 to 1073 K for 24 h)conditions following-solution-treatment (1323 K for 0.5 h). There is only a limited increase in strength but a drastic reduction in the ductility, at 300 K, due to ageing at 923 K. There is strong dynamic strain-ageing (DSA) in the unaged (WQ) state from 623 to 823 K and it is essentially due to silicon in the solid solution. The degree of DSA decreases with the ageing temperature and DSA does not occur in specimens aged at 973 and 1073 K. In general, the ductility of the WQ as well as the aged material increases with test temperature, except in the range of DSA, where the ductility of WQ material is reduced. The mode of fracture of the WQ specimens remains ductile in the lower and higher ranges of test temperature, but changes to quasi-cleavage at intermediate test temperatures. The minimum in the ductility and quasi-cleavage mode of fracture at 773 K, in the WQ material, is due to strong DSA. Three different modes of fracture, namely faceted, ductile, and mixed intergranular and ductile in the lower, intermediate and higher range of test temperature, respectively, are observed also in the aged conditions (at and above 923 K) of the material. The tensile properties and fracture characteristics in the aged conditions are controlled by the silicides.     

Influence of ageing treatment on work hardening behaviour of a Ni-base superalloy

Thus it may be summarised that work hardening behaviour of the alloy superni 263 can not be analysed using the simple power law equation. The work hardening behaviour is satisfactorily analysed using the modified power law equation (Ludwigson equation). There is systematic variation in the different work hardening parameters K₁, n₁, K₂, n₂ and _C with the period of ageing at 800 °C. The drastic lowering of the parameters n₁ and e_up, from ageing even for a short duration, suggests that this material should be formed in fully solution treated condition and any precipitation of γ′ must be avoided for good formability.     

Throughput analysis of STS-based CDMA system with variable spreading factor in non-frequency selective Rayleigh fading channel

The throughput enhancement of space-time spreading (STS)-based code division multiple access (CDMA) system is investigated in this paper. Variable spreading factor (VSF) is utilized to improve the data throughput of the system in non-frequency selective Rayleigh fading channel. In this contribution, an analytical approach is proposed to compute a new expression for the bit error rate (BER) performance of the STS-based CDMA system against pre-despreading signal-to-noise-ratio (SNR) for different values of spreading factor. The other contribution of the paper is deriving a new analytical expression for the throughput enhancement of the VSF STS-based CDMA system in non-frequency selective Rayleigh fading channel. Simulation and analytical results demonstrate that using VSF method in STS-based CDMA system improves the throughput of the system by keeping the BER performance at a target level.     

Drag and lift coefficients of inclined finite circular cylinders at moderate Reynolds numbers

The flow around two-dimensional cylinders at moderate Reynolds numbers has been much studied, both for cylinders perpendicular to the flow and for cylinders yawed to the flow. In contrast, yawed finite aspect ratio cylinders have received little attention. In this article we describe computer simulations of cylinders with aspect ratios 2  L/D  20 yawed at angles 0°  α  90° relative to a free stream. The simulations were carried out for Reynolds numbers in the range 1  Re  40. The simulations show that the Independence Principle [Zdravkovich MM. Flow around circular cylinders, vol. 2: applications. New York: Oxford University Press; 2003[1]] is not accurate for α  45°. We have also found that for all aspect ratios, the ratio of the lift to drag force reaches a maximum for 40° < α < 50°. Finally, we present C_L and C_D relationships as best curve fits to computational data.     

Yield and fracture behaviour of cross-linked epoxies

The yield stress and fracture energies of a series of cross-linked epoxy resins were studied in order to correlate the macroscopic mechanical properties with the polymer microstructure. Five networks with varying cross-link densities were synthesized by reacting a homologous series of epoxy resins with stoichiometric quantities ofm-phenylenediamine. For all the networks, the yield stress decreased with increasing temperatures in accordance with the predictions of the Eyring theory of viscosity. At constant temperatures, the yield stress decreased with increasing molecular weight between cross-links. The fracture studies revealed two distinct types of crack propagation behaviour above and below approximately 0 °C. Below 0 °C the cracks propagated in a stable and continuous manner, while the crack propagation behaviour changed to an unstable stick-slip mode as the test temperature was increased above 0 °C. For unstable crack growth, the fracture energies for crack initiation increased with increasing temperature, while the fracture energies for crack arrest were, within the limits of experimental error, independent of temperature. The crack arrest fracture energies were similar in magnitude to the fracture energies for stable crack propagation. An empirical power-law type correlation was observed between the glassy arrest fracture energies and the average molecular weight between cross-links. Micrographs of specimens which failed by the unstable, stick-slip mode revealed characteristic plastic deformation zones which highlighted the positions of crack initiation and arrest along the crack path. The deformation zone widths were observed to increase with increasing test temperatures, providing evidence of greater localized plastic deformations and higher fracture initiation energies at higher temperatures.     

On the formation of the diamond grain configuration during high temperature creep and fatigue

A study has been made of the influence of test variables on the formation of the diamond grain configuration during high temperature creep and fatigue deformation of a wide variety of metals. The proposed mechanisms for the formation of this interesting grain morphology are reviewed. It is concluded that the diamond grain configuration arises from a balance between grain-boundary sliding, grain-boundary mobility, intragranular deformation and defect imbalance across the grain boundaries and that it tends to be stabilized by intergranular cavitation. While the phenomenon occurs during high temperature fatigue in a variety of metals irrespective of their crystal structure, during creep it has been observed only in to h c p metals. It is surmised that the occurrence of the diamond array of grain boundaries during creep deformation in h c p metals is aided by the limited number of slip systems which leads to high defect imbalances in adjacent grains and consequently high driving forces for grain-boundary migration. On the basis of quantitative metallography involving measurements of the number of edges per grain section, the number of grains meeting at vertices, angular distribution histograms and grain-boundary lengths in different angular orientations with respect to the stress axis in "annealed" and "diamond" microstructures, it is concluded that the shape of the "diamond" grain is essentially the same as that of the "annealed" grain but in a distorted form.     

Oxidation behaviour of the near α-titanium alloy IMI 834

Oxidation behaviour of the near α-titanium alloy IMI 834 was investigated over a range of temperatures, from 600–800°C, in air. Specimens were solution-treated in the α + β and β phase fields for 1 h and 1/2 h, respectively and cooled in air to room temperature. The solution treated samples were subjected to stabilization treatment at 700°C for 2 h, followed by cooling in air. Oxidation behaviour of these samples was studied from 600–800°C in air, for 50 h. The morphology of the scales formed was examined by SEM and the phases present in the scales were characterized by X-ray diffraction. While there was little oxidation at 600°C, the rate of oxidation increased at higher temperatures. In general, the rate of oxidation was found to be more in the α + β treated condition than that in the β treated one. The results are discussed in terms of the characteristics of the oxide film formed under different conditions.