Calculation of the phonon dispersion curves for b.c.c. transition metals using the Finnis-Sinclair potentials

Abstract

The phonon dispersion curves for body-centred cubic transition metals are calculated using Finnis-Sinclair potentials. The accuracy of results obtained for metals of the VIa and Va groups is commented on.     

Investigation of the interaction of He and D in FeBSi alloy

He and H can be produced by nuclear reaction. In addition, energetic particles of He and T and D, which are isotopes of H, in the plasma of fusion reactor induce the damage in the surface of materials, such as erosion, sputtering and blistering. To investigate the interaction of He and D, amorphous and crystalline FeBSi alloys were irradiated by He or D₂ or He?+?D₂ ions with 5?keV. The results of thermal desorption indicated that more He atoms were trapped in both the amorphous and crystalline alloy irradiated by He ions than D atoms in those alloys irradiated by D₂ ions. Although He and D atoms were trapped in FeBSi alloy irradiated by He?+?D₂ ions, desorption peaks of D₂ and He were separated. Absorption of D in an amorphous alloy was influenced by the presence of He; however, absorption of He was independent of D₂ irradiation in both alloys.     

Local translational order in the icosahedral quasicrystalline phase of V41Ni36Si23

Abstract

The local translational order of the icosahedral quasicrystalline phase in rapidly solidified V₄₁Ni₃₆Si₂₃ has been investigated by means of selected-area electron diffraction and high-resolution electron microscopy. Experimental results show that translational order always occurs in the twofold direction and can be observed when the quasicrystal is examined along its fivefold and threefold as well as twofold axes. Sometimes it occurs in two or three coplanar twofold directions simultaneously. In these cases some crystalline islands exist in the icosahedral quasicrystal and this corresponds to the initial stage of transformation from a quasicrystal to the stable crystalline phase.     

Knowing when to seek anger: Psychological health and context-sensitive emotional preferences

According to hedonic approaches to psychological health, healthy individuals should pursue pleasant and avoid unpleasant emotions. According to instrumental approaches, however, healthy individuals should pursue useful and avoid harmful emotions, whether pleasant or unpleasant. We sought to reconcile these approaches by distinguishing between preferences for emotions that are aggregated across contexts and preferences for emotions within specific contexts. Across five days, we assessed daily confrontational and collaborative demands and daily preferences for anger and happiness. Somewhat consistent with hedonic approaches, when averaging across contexts, psychologically healthier individuals wanted to feel less anger, but not more happiness. Somewhat consistent with instrumental approaches, when examined within contexts, psychologically healthier individuals wanted to feel angrier in more confrontational contexts, and some wanted to feel happier in more collaborative contexts. Thus, although healthier individuals are motivated to avoid unpleasant emotions over time, they are more motivated to experience them when they are potentially useful.     

Evaluating the Acute Contributions of Dopaminergic Replacement to Gait With Obstacles in Parkinson's Disease

The influence of dopaminergic replacement (DR) on gait in people with Parkinson's disease (PD) is well documented. However, little is known about the acute effects of dopamine on more complex locomotor tasks that require visual guidance to avoid obstacles during gait. The authors investigated the influence of DR on locomotor behavior in a task where movement planning and control might be challenged by the height of the obstacle. The PD group included patients diagnosed with idiopathic PD (n = 12), as well as healthy controls (n = 12). Patients walked and stepped over obstacles of different heights before (OFF) and after (ON) levodopa intake. Spatial adjustments were not modulated by DR, but the step time to perform these anticipatory gait adjustments was longer only in PD-OFF (compared with healthy controls) when approaching the highest obstacle, but not PD-ON. During the crossing phase, trail limb toe clearance of PD patients was shorter than healthy controls only during the OFF state. ON-OFF comparisons were significantly different only for the time to reach the lead foot clearance over the highest obstacle. In summary, DR partially improved movement slowness but did not directly affect movement amplitude of lower limb regulation in this gait task.     

Well-Being in the Batswana Cultural Context: Constructs and Measures

The study investigated wellbeing in a Setswana-speaking sample. Participants (n=459, males =141 females =318; 22% = aged between 30 and 40 years) completed the General Psychological Well-being Scale (GPWS: Khumalo, Temane & Wissing, 2010) and the Mental Health Continuum Short-Form (MHC-SF: Keyes, 2005b). Data were analyzed applying classical test theory (CTT), structural equation modelling (SEM; measurement model) and item response theory (IRT; Rasch model). Both GPWS and MHC-SF measures yielded a multidimensional wellbeing factor structures indicative of a hedonic-eudaimonic wellbeing overlap. Further qualitative research could explore the cultural contextual meanings of wellbeing in Setswana culture.     

Structure of a cubic phase related to Cd?Mg?rare-earth quasicrystals

The structure of a Cd₆₈Mg₁₂Dy₂₀ crystalline phase denoted as the φ-phase, which has a composition close to that of the Cd₆₆Mg₂₁Dy₁₃ icosahedral quasicrystalline phase, has been investigated by electron diffraction and scanning transmission electron microscopy (STEM). The φ phase has a fcc lattice with a = 21.6Å. High-angle annular dark-field STEM with Z contrast confirms that the phase has the Cd₄₅Sm₁₁-type structure. The atomic cluster in the structure is shown to be characterized by a Friauf polyhedron with tetrahedral symmetry.     

Nonconscious goals can shape what people want to feel

Goals can determine what people want to feel (e.g., Tamir et al., 2008), but can they do so even when they are primed outside of conscious awareness? In two studies, participants wanted to feel significantly less angry after they were implicitly primed with a collaboration goal, compared to a neutral prime. These effects were found with different implicit priming manipulations, direct and indirect measures of emotional preferences, and when controlling for concurrent emotional experiences. The effects were obtained in social contexts in which the potential for collaboration was relatively higher (Study 1) and lower (Study 2). Also, similar effects were found when collaboration was activated nonconsciously (Studies 1–2) and consciously (Study 2). By showing that nonconscious goals can shape emotional preferences, we demonstrate that what people want to feel can be determined by factors they are unaware of.     

Family Caregiver’s Positive,Negative, and Ambivalent Feelings Towards Stroke Survivors: Association with Psychological Well-Being

Applied Research in Quality of Life - Ambivalence is the simultaneous experience of positive and negative feelings toward a specific person. Recent research suggested ambivalence is negatively...