Temperature dependence of surface reconstructions of Au on Pd(110)

Surface reconstructions of Au film on Pd(110) substrate are studied using a local Einstein approximation to quasiharmonic theory with the Sutton-Chen interatomic potential. Temperature dependent surface free energies for different coverages and surface structures are calculated. Experimentally observed transformations from $(1\times1)$ to $(1 \times 2)$ and $(1 \times 3)$ structures can be explained in the framework of this model. Also conditions for Stranski-Krastanov growth mode are found to comply with experiments. The domain of validity of the model neglecting mixing entropy is analyzed.Comment: 7 pages, REVTeX two-column format, 3 postscript figures available on request from [email protected] To appear in Phys. Rev. Letter

Practical Learning and Theory-Practice as Perceived by Student Nurses in Universiti Malaysia Sabah

Introduction: The theory-practice gap is arguably the most important issue in nursing today, given that it challenges the concept of research based practice, which is the basis of nursing as a profession. Majority of the student nurses shared their views that some of the practical procedures that they learned during their theory sessions was different from what was practiced in the wards which caused some worries among the student’s that it may affect their performance during their Obstructive Structured Clinical Examination (OSCE). Aim: The aim of this study is to determine the perception of nursing students’ towards the practical learning and strategies to bridge the theory-practice gap. Method: Survey questionnaires pertaining to perception towards the practical learning and strategies to bridge the gap were distributed among 60 UMS students nurses Year 2 and Year 3 to understand their perception on theory-practice gap. Results: As for clinical practice experience, all (100%) students stated that clinical instructor and nursing educators did orientation during the first time in the wards or clinic. Forty students (66.67%) responded “yes” that supervision occurs all the time during the clinical posting. As for practical learning, all students indicated that simulation lab was found in their faculty and nursing block. On strategies, 50 (83%), students agreed that it is helpful if nurse educators spend time in clinical practice to update their skills and re-experiencing the realities of practice. Thirty eight (63%) students agreed that that they need clarification of difficult concepts from staff nurses, clinical instructors and nurse educators. Conclusion and Recommendations: Responses from students have suggested some strategies in bridging the gap between theory and practice such as continuous communication between the education and clinical area

COMPUTATION OF STRUCTURE AND ENERGY OF THE Σ3 (21(-1)) TILT BOUNDARY IN SILICON

On compare entre elles differentes determinations expérimentales et théoriques du vecteur de translation [MATH] du joint de grains de flexion Σ3 (21[MATH]) dans le silicium. Un calcul utilisant le potentiel de Keating donne un vecteur [MATH] et une structure atomique en très bon accord avec le calcul de liaison forte de Paxton et Sutton et avec les déterminations expérimentales de Bourret et al. sur le germanium. Cela confirme la validité du modèle de Papon et Petit pour la structure atomique de ce joint de grains.Different experimental and theoretical determinations of the rigid body translation [MATH] in the Σ3 (21[MATH]) tilt grain boundary in silicon are compared. A calculation using Keating's potential gives a [MATH] vector and an atomic structure in very good agreement with Paxton and Suttont's tight binding calculation and with experimental determinations on germanium by Bourret et al. This confirms the validity of Papon and Petit's model for the atomic structure of this grain boundary

Calculation of Grain Boundary Free Energy by Molecular Dynamics and Tests on Silicon Perfect Crystal

info:eu-repo/semantics/publishedPolycrystalline Semiconductors II

Spectroscopie des composés Ga1-xAlxAs par modulation de longueur d'onde

Reflectivity measurements by wavelength modulation have been performed from 1.3 to 5.5 eV on epitaxial layers of Ga 1-xAl xAs with different compositions (0 < x < 0.62). The results, in good agreement with earlier electroreflectance measurements on these compounds, prove the great interest of this method in spite of its technical difficulties.On a effectué des mesures de réflectivité par modulation de longueur d'onde entre 1,3 et 5,5 eV sur des couches épitaxiales de Ga1- xAlxAs de composition variable 0 < x < 0,62. Les résultats, qui sont en bon accord avec les mesures antérieures d'électroréflectance sur ces composés, prouvent que cette méthode de modulation peut être d'un grand intérêt malgré ses difficultés techniques

Free Energy of the ?= 11 (332) Tilt Grain Boundary in Silicon

info:eu-repo/semantics/publishedIntergranular and Interphase Boundaries in Material

CUBIC [001] TWIST CSL GRAIN BOUNDARIES STUDY BY MEANS OF RANDOM WALK

The random walk procedure has been applied on some typical relaxed CSL twist grain boundaries. The relaxation has been achieved by means of the Molecular Dynamics method, applied on the CSL computational cells. Some of the random walk parameters are discussed and the information dimension is examined as a function of the rotation angle θ. The remarkable anisotropy observed in the parameters between the grain boundary and the bulk is common to many dynamical properties of the grain boundaries

Direct Free Energy Estimates along a Real Path by Means of Constrained Molecular Dynamics

info:eu-repo/semantics/publishedIntergranular and Interphase Boundaries in Material

Simulation of NMR Fermi contact shifts for Lithium battery materials: the need of an efficient hybrid functional approach

In the context of the development of NMR Fermi contact shift calculations for assisting structural characterization of battery materials, we propose an accurate, efficient, and robust approach based on the use of an all electron method. The full-potential linearized augmented plane wave method, as implemented in the WIEN2k code, is coupled with the use of hybrid functionals for the evaluation of hyperfine field quantities. The WIEN2k code is able to fully relax relativistic core states and uses an autoadaptive basis set that is highly accurate for the determination of the hyperfine field. Furthermore, the way hybrid functional approaches are implemented offers the possibility to use them at no additional computational cost. In this paper, NMR Fermi contact shifts for lithium are studied in different classes of paramagnetic materials that present an interest in the field of Li-ion batteries: olivine LiMPO4 (M = Mn, Fe, Co, Ni), anti-NASICON type Li3M2(PO4)3 (M = Fe, V), and antifluorite-type Li6CoO4. Making use of the possibility to apply partial hybrid functionals either only on the magnetic atom or also on the anionic species, we evidence the role played by oxygen atoms on polarisation mechanisms. Our method is quite general for an application on various types of materials