77 research outputs found

    Energy Calculations of The Realistic Quantum Slab

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    We calculated the total energy of a semiconductor quantum dot which is defined by the trench gate method. In our calculation we used a recently developed energy functional called ``orbital-free energy functional". We compared the total energies obtained by Thomas-Fermi approximation, orbital-free energy functional and standard local-density approximation for the square quantum slab geometry. We have seen that this newly developed energy functional is numerically very efficient, superior to the Thomas-Fermi approximation and is in good agreement with the local-density approximation for two different sizes of quantum dot systems.Comment: 8 pages, 4 figure

    The effect of theoretical and simulation training on medical errors of nurse students in karadeniz technical university, Turkey

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    Objective: To assess the efficacy of theoretical training related to medical errors and patient safety and practical simulation training on students' knowledge and skill levels. Methods: This experimental study was conducted from March 28 to May 18, 2016, at nursing department of a university and comprised of students attending the third grade of the nursing school. The subjects were divided into two equal experimental and control groups. The experimental group, among other things, received simulation training that involved a demonstration and subsequent one-to-one practice. Data was collected on a proforma that included demographic information, pretest and post-test scores, checklists for pre-assessments and final assessments related to nursing practices. Results: There were 62 nurses divided into two groups of 31(50%) each. The difference between post-test scores of the concerning theoretical training about medical errors and patient safety was statistically significant (p0.05), while there was a significant difference between their final assessments (p<0.05). Conclusion: Theoretical education increased students' levels of knowledge regarding medical errors and patient safety, and the the practical simulation training reduced malpractices by improving skills. © 2018, Pakistan Medical Association. All rights reserved

    Characterization of platinum nitride from first-principles calculations

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    We have performed a systematic study of the ground state properties of the zinc-blende, rock-salt, tetragonal, cuprite, fluorite and pyrite phases of platinum nitride by using the plane wave pseudopotential calculations within the density functional theory. The equilibrium structural parameters and bulk moduli are computed within both the local density approximation (LDA) and generalized gradient approximation (GGA). The comparison of the equation of state (EOS) calculated within the LDA for the pyrite structure with the experimental results demonstrates an excellent agreement, hence the use of the LDA rather than the GGA is essential. Complete sets of elastic moduli are presented for cubic forms. The analysis of the results reveal that the pyrite phase with PtN2 stoichiometry leads to the formation of a hard material with the shear modulus G = 206GPa. The electronic structure of pyrite PtN2 is given, which shows a narrow indirect gap. The vibrational properties of platinum nitride are investigated in detail from lattice dynamical calculations. The calculations show that fluorite and pyrite structures are dynamically stable as well. However, the calculated vibrational modes of pyrite PtN2 do not show complete agreement with experimental Raman frequencies. © 2009 IOP Publishing Ltd

    Theoretical Investigation of Local Electron Temperature in Quantum Hall Systems

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    In this work we solve thermo-hydrodynamical equations considering a two dimensional electron system in the integer quantum Hall regime, to calculate the spatial distribution of the local electron temperature. We start from the self-consistently calculated electrostatic and electrochemical potentials in equilibrium. Next, by imposing an external current, we investigate the variations of the electron temperature in the linear-response regime. Here a local relation between the electron density and conductivity tensor elements is assumed. Following the Ohm's law we obtain local current densities and by implementing the results of the thermo-hydrodynamical theory, calculate the local electron temperature. We observe that the local electron temperature strongly depends on the formation of compressible and incompressible strips.Comment: 10 pages, 4 figure

    Polynomial Solution of Non-Central Potentials

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    We show that the exact energy eigenvalues and eigenfunctions of the Schrodinger equation for charged particles moving in certain class of non-central potentials can be easily calculated analytically in a simple and elegant manner by using Nikiforov and Uvarov (NU) method. We discuss the generalized Coulomb and harmonic oscillator systems. We study the Hartmann Coulomb and the ring-shaped and compound Coulomb plus Aharanov-Bohm potentials as special cases. The results are in exact agreement with other methods.Comment: 18 page

    The role of open abdomen in non-trauma patient : WSES Consensus Paper

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    The open abdomen (OA) is defined as intentional decision to leave the fascial edges of the abdomen un-approximated after laparotomy (laparostomy). The abdominal contents are potentially exposed and therefore must be protected with a temporary coverage, which is referred to as temporal abdominal closure (TAC). OA use remains widely debated with many specific details deserving detailed assessment and clarification. To date, in patients with intra-abdominal emergencies, the OA has not been formally endorsed for routine utilization; although, utilization is seemingly increasing. Therefore, the World Society of Emergency Surgery (WSES), Abdominal Compartment Society (WSACS) and the Donegal Research Academy united a worldwide group of experts in an international consensus conference to review and thereafter propose the basis for evidence-directed utilization of OA management in non-trauma emergency surgery and critically ill patients. In addition to utilization recommendations, questions with insufficient evidence urgently requiring future study were identified.Peer reviewe

    The Effect of the Electron Temperature on Incompressible Strips in Quantum Hall Regime

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    We used a theory of thermo-hydrodynamics in quantum Hall system observed on a two-dimensional system in high magnetic fields at low temperatures, to investigate the electron temperature in the linear response regime. The variation of electron temperature exhibits an antisymmetric distribution of the incompressible strips. According to this result, we obtain effects of the electron temperature on the current density distribution using a Thomas-Fermi-Poisson approximation. We observe that incompressible strips change with increasing and/or decreasing the electron temperature with regard to the lattice temperature

    SHALLOW DONORS IN A COUPLED TRIPLE GRADED QUANTUM WELL UNDER THE ELECTRIC AND MAGNETIC FIELDS

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    The binding energy of the donor in three different shaped triple graded GaAs-(Ga, Al)As quantum wells which is obtained by changing the depth of the central-well potential (Vo) is calculated by using a variational approach. The results have been obtained in the presence of uniform magnetic and electric fields applied along the growth direction as a function of the impurity position. In addition, we also give the binding energy of the hydrogenic donor impurity for triple square quantum wells having the same physical parameters with triple graded quantum well structures in order to see the effect of different geometric confinements on the donor impurity binding energy.Triple quantum wells, hydrogenic impurities, graded well, 71.55
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