Preferred Language
Articles
/
jih-883
A Theoretical Investigation of Enhanced Thermoelectric Figure of Merit of Low-Dimensional Structures
...Show More Authors

 The power factors and electronic thermal conductivities in bismuth telluride (Bi2Te3), lead-telluride (PbTe), and gallium arsenide (GaAs) at room temperature (300K) quantum wires and quantum wells are theoretically investigated. Our formalism rigorously takes into account modification of these power factors and electronic thermal conductivities in free-surface wires and wells due to spatial confinement. From our numerical results, we predict a significant increase of the power factor in quantum wires with diameter w=20 Ã…. The increase is always stronger in quantum wires than in quantum wells of the corresponding dimensions. An unconfined phonon distribution assumed based on the bulk lattice thermal conductivity is then employed to evaluate the possible enhancement of the thermoelectric figure of merit. The electronic thermal conductivity of a 20Ã… diameter wire and a 20Ã… layer thickness is found to be of no significant decrease. The resultant ZT, calculated for Bi2Te3, PbTe and GaAs, quantum wires and quantum wells, showed increase significantly. The additional thermoelectric figure of merit enhancement is mostly due to the two- and one-dimensional carrier confinement which lead to the enhancement of power factor.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Sep 30 2020
Journal Name
Neuroquantology
Theoretical Analysis of the Electronic Current at Au/PTCDA Interface
...Show More Authors

Abstract We have been studied and analysis the electronic current at the interfaces of Au/PTCDA system according to simple quantum mode for the electronics transition rate due to postulate quantum theory. Calculation of electronic current were performed at interface of Au/PTCDA as well as for investigation the feature of electronic density at this devices. The transition of electronic current study under assume the electronic state of Au and PTCDA were continuum and the states of electrons must be closed to energy level for Au at Fermi state, and the potential at interface feature depended on structure of Au and PTCDA material. The electronic transition current feature was dependent on the driving force energy that results of absorption ene

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (4)
Scopus Crossref
Publication Date
Fri Aug 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Experimental & Theoretical Analysis of Composite (Polyester & Silicon-Carbide) Cantilever Beam
...Show More Authors

A cantilever beam is made from composite material which is consist of (matrix: polyester) and (particles: Silicon-Carbide) with different volume fraction of particles. A force is applied at the free end of beam with different values. The experimental maximum deflection of beam which occurs at the point of the applied load is recorded. The deflection and slope of beam are analyzed by using FEM modeling. MATLAB paltform is built to assemble the equations, vector and matrix of FEM and solving the unknown variables (deflection and slope) at each node. Also ANSYS platform is used to modeling beam in finite element and solve the problem. The numerical methods are used to compare the results with the theoretical and experimental data. A good ag

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Theoretical Investigations of High Power Yb3+: YAG Thin-Disk Laser
...Show More Authors

     The present study includes a theoretical treatment to derive the general equations of pumping threshold power ( ), laser output power (Pout), and laser device efficiency (ƞ) of the element-doped thin-disk laser (Yb3+) with a quasi-three-level pumping scheme in the continuous wave mode at a temperature of (299K°). In this study, the host crystals (YAG) were selected as typical examples of this laser design in a Gaussian transverse mode. The numerical solution of these equations was made using Matlab software by selecting the basic parameters from the recently published scientific articles for the laser design of these crystal hosts. According to this simulation, this article studied the effect o

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Mar 30 2013
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Theoretical Study on Heat Transfer in the Presence of Fouling
...Show More Authors

The fouling depositions of crude oil stream were studied theoretically in a shell and tube heat exchanger to investigate the effect of depositions on the heat transfer process. The employed heat exchanger was with steam flowing in the inner tubes and crude oil in the shell at different velocities and bulk temperatures. It is assumed that fouling occurs only on the heated stream side (crude oil). The analysis was carried out for turbulent flow heat transfer conditions with wide range of Reynolds number, bulk temperature and time. Many previously proposed models for fouling resistance were employed to estimate a new model for fouling rate. It is found that the fouling rate and consequently the heat transfer coefficient were affected by Rey

... Show More
View Publication Preview PDF
Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
Space-Charge Effect on the Theoretical Design of Enzil Lens
...Show More Authors

The presentwork is a theoretical study in the field of charged particle optics. It concentrates on the design of electrostatic enzil lens for focusing charge particles beams, using inverse method in designingthe electrostatic lens. The paraxial ray equation was solved to obtain the trajectory of the particles, the optical properties such as the focal length and spherical and chromatic aberration coefficients were determined. The shape of the electrode of the electrostatic lens were determined by solving poison equation and the results showed low values of spherical and chromatic aberrations, which are considered as good criteria for good design.

View Publication Preview PDF
Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Physics
Power dissipation and time of breakdown in AC discharge of argon at a low pressure in the frequency range 5-10 kHz
...Show More Authors

The influence of 5-10 kHz audio frequency on the power dissipation in ac discharge of argon gas was studied experimentally, at pressures 50-80 mTorr and electrodes separation 10 cm (pd range 0.5-0.8 Torr.
cm). The measurements have shown that the discharge behavior in the ac circuit is equivalent to a series RC circuit. It is observed that the variation curve of discharge power P with the frequency f is approximately has a Gaussian shape. It is also observed that the curve of Pm- pd is the inverse of Paschen curve, where Pm is the maximum power in the frequency range. The time of breakdown is estimated from the curve of P- f.

View Publication Preview PDF
Publication Date
Thu Mar 21 2024
Journal Name
Egyptian Journal Of Medical Human Genetics
Low heterozygosity for rs3811050, a 5 prime untranslated region variant of the gene encoding interleukin-38 (IL1F10), is associated with a reduced risk of systemic lupus erythematosus
...Show More Authors
Abstract<sec> <title>Background

Interleukin-38 (IL-38), an inflammatory cytokine discovered in recent years, has been implicated in the pathogenesis of systemic lupus erythematosus (SLE). IL-38 is encoded by the IL1F10 (interleukin 1 family member 10) gene. Genetic variants of this gene have been associated with susceptibility to a number of autoimmune and inflammatory diseases, while their association with SLE risk has not been explored. In this case–control study, two novel variants of the 5 prime untranslated region (5′UTR) of the IL1F10 gene, rs3811050 C/T and rs3811051 T/G, were investigated

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Mon Oct 01 2012
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Effectiveness of Low Level Laser in the Treatment of Carpal Tunnel Syndrome
...Show More Authors

Background: Carpal tunnel syndrome (CTS) is one of common peripheral nerve disorder which involves an entrapment neuropathy of the median nerve at the wrist which occurs either due to primary idiopathic cause or secondary to systemic causes. The diagnosis of CTS is clinical and supported by neurophysiological analysis. Surgical intervention is the main treatment modality.
Objective: The aim of the present study is to evaluate the effectiveness of low level laser therapy (LLLT) to treat mild – moderate CTS cases.
Pateients and methods: The study involves 60 symptomatic patients complaining of CTS were divided into two groups. Group A was subjected to real LLLT by Gallium – Arsenide (Ga-As) laser (904 nm), whereas group B was sub

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Effect of Cryogenic Treatment on the Properties of Low Carbon A858 Steel
...Show More Authors

This study is concerned with the effect of Deep Cryogenic Treatment (DCT) at liquid nitrogen temperature (-196 o C) on the mechanical properties and performance of low carbon steel (A858). The tests specimens were divided in to two groups, the first group was subjected to the conventional heat treatment of normalizing, and the second group was also normalized then subjected to (DCT). The results have shown that after (DCT), the Hardness, Tensile properties and the impact energy absorbed were all slightly increased. However the fatigue test showed some positive improvement in fatigue limit by 20(N/mm2 ), and the volume wear rates at different loads were significantly decreased after (DCT). The changes in microstructure due to (DCT) were c

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Aug 01 2020
Journal Name
Jordan Journal Of Physics
Theoretical Simulation of Backscattering Electron Coefficient for SixGe1-x/Si Heterostructure as a Function of Primary Electron Beam Energy and Ge Concentration
...Show More Authors

Abstract: This study aims to investigate the backscattering electron coefficient for SixGe1-x/Si heterostructure sample as a function of primary electron beam energy (0.25-20 keV) and Ge concentration in the alloy. The results obtained have several characteristics that are as follows: the first one is that the intensity of the backscattered signal above the alloy is mainly related to the average atomic number of the SixGe1-x alloy. The second feature is that the backscattering electron coefficient line scan shows a constant value above each layer at low primary electron energies below 5 keV. However, at 5 keV and above, a peak and a dip appeared on the line scan above Si-Ge alloy and Si, respectively, close to the interfacing line

... Show More
View Publication
Scopus (1)
Scopus Clarivate Crossref