Room temperature ferromagnetism and photoluminescence of nanocrystalline Zn1 − xCoxO thin films prepared by sol–gel MOD

Zn_1???xCo_xO (ZC) [x?=?0, 1, 3, 5, 7 and 9?mol%] thin films were prepared by sol–gel combined metallo-organic decomposition method. The films were deposited on the Si substrate with spin-coating technique and annealed at 600?°C for 3?h. X-ray diffraction pattern shows the formation hexagonal wurtzite phase and distortion (c/a) decreases with increasing Co concentration in ZnO. The average grain size is measured using Scherer relation. Atomic force microscopy is used to confirm the formation of nanograins resulted by the use of polyethylene glycol as surfactant. The photoluminescence was recorded by using He-Cd laser of excitation wavelength 325?nm in wavelength region of 350–650?nm which exhibits some influence of Co doping on the multiplication of defects such as O vacancies, Zn interstitials and grain boundary defects. All thin films show room temperature ferromagnetism except pure ZnO which is diamagnetic and 9?mol% of Co shows paramagnetism. This behaviour is interpreted as due to fluctuations in the magnetic ordering, depending on grain size and site location in grain boundaries or oxygen vacancies.     

Neutron and X-ray diffraction studies and cohesive interface model of the fatigue crack deformation behavior

The crack-tip deformation behavior during a single overload, fatigue test of ferritic stainless steel, and Ni-based HAYNES 230 superalloy is studied at different structural levels using (1) neutron-diffraction, from which both the elastic-lattice strain and volume-averaged total dislocation densities are obtained, (2) polychromatic X-ray microdiffraction to probe the geometrically necessary dislocations and boundaries distribution, and (3) an irreversible and hysteretic cohesive interface model which has been implemented into a finite element framework to simulate the stress/strain evolution near the fatigue crack tip. Neutron strain measurements and finite element simulations are in qualitative agreement on the macroscopic length scale. Large plastic deformation induced by the overload and the resulting compressive residual strains are observed in front of the crack tip after the overload, and are the principal reason for the fatigue-crack-growth retardation. Strong strain gradients surrounding the crack propagation result in the formation of a high density of geometrically necessary dislocations near the fractured surface and cause local lattice rotations on the submicron level.     

high-resolution electron microscopy at a (113) symmetric Thermally activated step motion observed by tilt grain-boundary in aluminium

Grain-boundary migration is demonstrated to proceed by lateral propagation of a small step in a (113), [110] symmetric Al tilt grain-boundary. In-situ high-resolution (transmission) electron microscopy (HREM) at 523K allowed the study of atomic-scale detail at video rates during the migration process. The grain-boundary translational states on both sides of the step are identical, which leads to a step dislocation. This defect can move laterally by a combination of climb and glide. Dynamic HREM images indicate considerable atomic agitation within the dislocation core. A detailed temporal analysis of the step movements shows small random displacements of the dislocation core.     

Formation of ω -Al7Cu2Fe phase during laser processing of quasicrystal-forming Al–Cu–Fe alloy

The formation of an ω-Al₇Cu₂Fe phase during laser cladding of quasicrystal-forming Al₆₅Cu_23.3Fe_11.7 alloy on a pure aluminium substrate is reported. This phase is found to nucleate at the periphery of primary icosahedral-phase particles. A large number of ω-phase particles form an envelope around the icosahedral phase. On the outer side, they form an interface with an α-Al solid solution. Detailed transmission electron microscopic observations show that the ω phase exhibits an orientation relationship with the icosahedral phase. Analysis of experimental results suggests that the ω phase forms by precipitation on an icosahedral phase by heterogeneous nucleation and grows into the aluminium-rich melt until supersaturation is exhausted. The microstructural observations are explained in terms of available models of phase transformations.     

Log-normal nanograin-size distributions in nanostructured composites

A key challenge in the fabrication of superhard nanocomposite films is how to control the distribution of grain sizes in these materials. High-resolution transmission electron microscopy has been used to measure nanograin-size distributions in the Ti–B–N films with various B contents. The results show that the mean grain size decreases with increase of B content and the grain-size distribution conforms to a log-normal function when the hardness approaches a maximum value. The transition from normal to log-normal distributions can be determined by analysis in terms of a minimum information criterion. The origin of a log-normal size distribution probably results from heterogeneity arising from a diffusion-drift process.     

Design strategy for microalloyed ultra-ductile magnesium alloys

This article describes a design strategy deployed in developing ultra-ductile Mg alloys based on a microalloying concept, which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the resulting microstructural and mechanical properties. After processing, the so-designed alloys ZQCa3 (Mg–3Zn–0.5Ag–0.25Ca–0.15Mn, in wt.%) and ZKQCa3 (Mg–3Zn–0.5Zr–0.5Ag–0.25Ca–0.15Mn, in wt.%) reveal very fine grains (<10 µm), high ductility (elongation to fracture of up to 30%) at moderate strength or high strength (ultimate tensile strength of up to 350 MPa) at reasonable ductility. These properties are explained based on thermodynamic modelling, microstructure analysis including transmission electron microscopy studies, and microstructural and mechanical testing after annealing, and are compared to a related commercial alloy (ZK31).     

Enhancement on the faceted growth and the coarsening of the MnBi primary phase during the directional solidification under a high magnetic field

The effect of a high magnetic field on the morphology of the MnBi primary phase during the directional solidification has been investigated experimentally and the results show that an application of a high magnetic field has enhanced the faceted growth and the coarsening of the MnBi primary phase. This may be attributed to the effect of a high magnetic field on the diffusion of the solute Mn and the growth anisotropy of the MnBi crystal.     

Psychometric Properties of the Locus of Control of Behaviour Scale (LCBS) among Australians Seeking Alcohol and Other Drug (AOD) Treatment

Despite a paucity of studies evaluating the psychometric properties of the Locus of Control of Behaviour Scale (LCBS), it continues to be widely used in behavioural research. The present study sought to redress this gap in the literature. The 17‐item LCBS was administered to 373 Australians attending Alcohol and Other Drug (AOD) treatment agencies in the northern metropolitan region of Perth. Confirmatory factor analyses were conducted in order to determine which of several plausible measurement models provided the best fit for the data. A unidimensional model, recommended by the authors of the LCBS, and a two‐dimensional (Internal Locus of Control vs External Locus of Control) model provided poor fits. Other multidimensional models, differing only in the dimensionality of the externality factor, were also tested. A multidimensional model consisting of an Internal Locus of Control factor and four component External Locus of Control factors provided the best fit; however, the fit is probably best described as “reasonable” rather than “good.” A subsequent exploratory factor analysis using parallel analysis indicated a cohesive internality factor; however, the externality factor showed a tendency to fragment into smaller components. Results were discussed in terms of the problematic externality factor.     

Exploring the Factor Structure of the Proactive Coping Inventory: A Southern African Study

This study explored the factor structure of the Proactive Coping Inventory (PCI) to determine whether its six-factor structure holds within the Southern African context. Data on proactive coping were collected from students attending three universities, one each in Botswana (n=88, females=45.5%, mean age=21.31 years, SD=2.04), Namibia (n=38, females=47.4%, mean age=24.21 years, SD=3.47) and South Africa (n=496, females=56.9%; mean age=22.27 years, SD=2.60). Exploratory factor analysis was used to determine the factor structure of the PCI. Findings suggest that the PCI is comprised of two factors: Future-Oriented Coping (comprised of Proactive Coping, Reflective Coping, Strategic Planning and Preventive Coping) and Support Seeking (comprised of Instrumental Support Seeking and Emotional Support Seeking). This is in line with theory that suggests that individuals cope by means of persisting towards goal attainment.     

The Imagination of Images and Images of Imagination: How the Imagination Relates to Aging,Health, and Spirituality

ABSTRACT

Psychological literature suggests that religion and spirituality increase in late adulthood. Yet, operational definitions of spirituality and religiosity remain widely debated and inadequate for the concepts they are designed to measure. The empirical studies of religion and spirituality as one ages are of poor design and often measure only limited aspects of religion or spirituality. Few empirical studies exist which have been conceived to only study religiosity and spirituality in late adulthood. The purpose of this study was to determine the defining aspects of religiosity and spirituality using the Allport, Ross Intrinsic, Extrinsic Religiosity Scale, Ellison's Spiritual Well-Being Scale, and Neugarten's Life Satisfaction Instrument. Using a principal component factor analysis, the study examined the factor structure using an older adult sample of 320 individuals 65 years of age and older. Having a purpose in life combines with intrinsic religious questions for the first factor. Life satisfaction questions group together on two factors and extrinsic religiosity is clearly one factor. The scales used hold together well when combined. A new, shortened scale to measure aspects of religiosity and spirituality is proposed.