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A Theoretical Investigation of Enhanced Thermoelectric Figure of Merit of Low-Dimensional Structures
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 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.

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Publication Date
Thu Mar 01 2012
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Impact of Islamic Financial Inspection Thought on the Development of Inspection and comparing it with Positive Thought: Theoretical Comparative Study
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You Mohammed, you're prophet of God and I'm Gabriel)). With this heavenly call which Mohammed, the messenger of God (may God's mercies be on him), got and when he left Hiraa cave and after getting the aye ((read with your God's name)), a new period of mankind's history started. From that time, the greatest state was established. There was no public treasury and no public financial resources at that time. Abu Baker (God bless him) spent a lot of money to support the costs of the new mission. After Al-Hijra, the bases of establishing the Islamic state were available but it lacked administrative and financial organizing. Therefore the prophet was very keen to find Islamic system which ensures justice and availability of

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Publication Date
Thu Jan 15 2015
Journal Name
مجلة كلية التربية-المؤتمر العلمي التخصصي لكلية التربية
Investigation the Effect of Irradiation by Gamma-Ray on the Structural and Optical Properties of (CIGS) Films
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Publication Date
Thu Mar 02 2023
Journal Name
East European Journal Of Physics
Investigation of the Impact of Glass Waste in Reactive Powder Concrete on Attenuation Properties for Bremsstrahlung Ray
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Reactive Powder Concrete (RPC) is one of the most advanced recent high compressive strength concrete. This work explored the effects of using glass waste as a fractional replacement for fine aggregate in reactive powder concrete at levels of 0%, 25%, 50%, and 100%. Linear and mass attenuation coefficients have been calculated as a function of the sample's thickness and bremsstrahlung energy. These coefficients were obtained using energy selective scintillation response to bremsstrahlung having an energy ranging from (0.1-1.1) MeV. In addition, the half-value thickness of the samples prepared has been investigated. It was found that there is a reversal association between the attenuation coefficient and the energy of the bremsstrahlu

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Publication Date
Thu Mar 01 2018
Journal Name
Journal Of Engineering
Numerical Investigation of the Effect of Inserted Twisted Tape inside Submerged Bundle Tubes on its Thermal Performance
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Twisted tape insertion in smooth plain tube is one of types of passive methods that is used to enhance heat transfer. Swirl fluid flow inside tube and related heat transfer characteristics are very complex. ANSYS FLUENT (V 16.1) and ASPEN industrial program are used in analyzing this technique for enhancement heat transfer. A circular plain tube has length L=8534mm and 17 mm inner diameter with twisted tape has twist ratio of y = (H/D) = (150/17) =8.8 along with a plain tube were considered for this study. Eight Reynolds numbers (Re) of 784, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 are used to analyze the response of thermal performance. Crude oil API 28 exit temperature, film heat transfer coefficient, Nusselt number

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Publication Date
Wed Oct 24 2018
Journal Name
European Journal Of Environmental And Civil Engineering
Investigation the impacts of fuel oil contamination on the behaviour of passive piles group in clayey soils
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Publication Date
Fri Jun 29 2018
Journal Name
Journal Of Engineering
Numerical Investigation of the Effect of Inserted Twisted Tape inside Submerged Bundle Tubes on its Thermal Performance
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Twisted tape insertion in the smooth plain tube is one of the types of passive methods that are used to enhance heat transfer. Swirl fluid flow inside the tube and related heat transfer characteristics are very complex. ANSYS FLUENT (V 16.1) and ASPEN industrial program are used in analyzing this technique for enhancement heat transfer. A circular plain tube has length L=8534mm and 17 mm inner diameter with a twisted tape of twist ratio of y = (H/D) = (150/17) =8.8 along the plain tube were considered for this study. Eight Reynolds numbers (Re) of 784, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 are used to analyze the response of thermal performance. Crude oil API 28 exit temperature, film heat transfer coefficient, Nus

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Publication Date
Sun Sep 04 2016
Journal Name
Baghdad Science Journal
Investigation of the New Room Temperature Ionic Liquid of Al(NO3)3.9H2O with Urea CO(NH2)2
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Mixing aluminum nitrate nonahydrate with urea produced room temperatures clear colorless ionic liquid with lowest freezing temperature at (1: 1.2) mole ratio respectively. Freezing point phase diagram was determined and density, viscosity and conductivity were measured at room temperature. It showed physical properties similar to other ionic liquids. FT-IR,UV-Vis, 1H NMR and 13C NMR were used to study the interaction between its species where - CO ??? Al- bond was suggested and basic ion [Al(NO3)4]? and acidic ions [Al(NO3)2. xU]+ were proposed. Water molecule believed to interact with both ions. Redox potential was determined to be about 2 Volt from – 0.6 to + 1.4 Volt with thermal stability up to 326 ?.

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Publication Date
Thu Dec 01 2016
Journal Name
Journal Of Engineering
Analytical and Experimental Investigation for the Effect of Air Injection Angle on the Performance of Airlift Pump
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The effect of air injection angle on the performance of airlift pump used for water pumping has been studied analytically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90  (for conventional) to 45  and 22.5  (for modified). Continuity and one-dimensional momentum balance for the flow field with basic principle of two-phase flow and expressions of slip ratio and friction factor as function of flow rates were formulated. The analytical and experimental investigations were carried out f

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Publication Date
Fri Dec 30 2022
Journal Name
Eastern-european Journal Of Enterprise Technologies
Experimental investigation and modelling of residual stresses in face milling of Al-6061-T3 using neural network
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Milling process is a common machining operation that is used in the manufacturing of complex surfaces. Machining-induced residual stresses (RS) have a great impact on the performance of machined components and the surface quality in face milling operations with parameter cutting. The properties of engineering material as well as structural components, specifically fatigue life, deformation, impact resistance, corrosion resistance, and brittle fracture, can all be significantly influenced by residual stresses. Accordingly, controlling the distribution of residual stresses is indeed important to protect the piece and avoid failure. Most of the previous works inspected the material properties, tool parameters, or cutting parameters, bu

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Publication Date
Sun Apr 30 2023
Journal Name
Iraqi Journal Of Science
Synthesis and Investigation of the Structural Characteristics of Zinc Oxide Nanoparticles Produced by an Atmospheric Plasma Jet
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     In this paper, ZnO NPs were prepared using D.C high-voltage and high frequency with an output of 6 kHz at two different preparation times preparation (10,12) minutes. Transmission electron microscopy (TEM) with (FE-SEM) was used to examine the homogenous, compact, and dense surface of the zinc oxide nanoparticles created with apparent grain size determined by (XRD), XRD results explain that the increase of the preparation time from 10 minutes to 12-minute caused an increase in crystallite size. In addition, FE-SEM showed that the increase in the ZnO NPs cluster distribution with particle size increases with increasing the preparation time. AFM was also utilized to determine the degree of cooperation between the surfaces of the z

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