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alkej-344
The Effects of Long-Term Operation and High Temperature on Material Properties of Austenitic Stainless Steel Type 321H
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Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properties. Tensile properties of stainless steel (AISI 321H) were decreased as temperature increases; the trend of properties decreasing for the samples of un-used tube material is the same for the ex-used material. The trend of stress-strain curve will not change due to elevated temperature exposure for long time of service, except the yield strength will be higher in this diagram. The yield strength increased under these conditions, but the ability of material  which is elongated will decrease. Hardness and absorbed energy increased by 11.28 and 14% respectively when the material is aged for long time under effect of high temperature accompanied with creep effect.

Keywords:  Hardness, Impact, Mechanical Properties, Stainless Steel 321H, Mechanical Properties, Tensile Strength, Tube Furnace.

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Publication Date
Wed Jan 01 2014
Journal Name
مجلة إبن الھيثم للعلوم الصرفة و التطبيقية
دراسة تأثير درجة حرارة التلدين على الخواص التركيبية والبصرية لأغشية الرقيقة ZnSe
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الخلاصة ر 􀑧􀑧 ة التبخي 􀑧􀑧 رة بطريق 􀑧􀑧 ة المحض 􀑧􀑧 الرقيق ZnSe درس تأثير التلدين الحراري في بعض الخواص التركيبية والبصرية لأغشية ود 􀑧􀑧 ة حي 􀑧􀑧 لال تقني 􀑧􀑧 ن خ 􀑧􀑧 اعتين م 􀑧􀑧 دة س 􀑧􀑧 373,473 ) م )K راوح 􀑧􀑧 رارة تت 􀑧􀑧 درجات ح 􀑧􀑧 ة ب 􀑧􀑧 550±20 ) والملدن ) nm مك 􀑧􀑧 راري بس 􀑧􀑧 الح ة 􀑧􀑧 الاشعة السينية درست الخواص التركيبية واظھرت بأن الاغشية تمتلك طبيعة بلورية (تركيب مكعب). وبعد اجراء المعامل واص 􀑧􀑧 ا ا

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Publication Date
Sun Nov 01 2015
Journal Name
Journal Of Engineering
Effects of Welding Parameters on Temperature Distribution and Tensile Strength of AA6061-T6 Welded by Friction Stir Welding
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The present research aims to study the effect of friction stir welding (FSW) parameters on temperature distribution and tensile strength of aluminum 6061-T6. Rotational and traverse speeds used were (500,1000,1400 rpm) and (14,40,112 mm/min) respectively. Results of mechanical tests showed that using 500rpm and 14mm/min speed give the best strength. A three- dimensional fully coupled thermal-stress finite element model via ANSYS software has been developed. The Rate dependent Johnson-Cook relation was utilized for elasto-plastic work deformations. Heat-transfer is formulated using a moving heat source, and later used the transient temperature outputs from the thermal analysis to determine equivalent stresses in the welde

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Publication Date
Tue Feb 26 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effective Unified Accounting System on the Characteristics Quality of Accounting Information: An Applied Research in Municipality of AL-Najaf City
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The system of accounting information role in the success of the economic unit, whether for-profit or non-purposeful, and through the availability of financial reports of information accounting for quality properties in the financial reports, which are the final product of all departments, sections and other parties, including help in strengthen the decisions of the administration and operations of Information economic Unity. The municipalities of economic units, non-profit, which is characterized by certain characteristics, including the multiplicity of activities (service, productivity, construction) and multiple sources of access to resources, so the accounting information system that seeks to provide decision makers with information o

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Publication Date
Fri Jan 01 2016
Journal Name
World Scientific News
Effect of annealing temperature on the structural and optical properties of CdSe: 1% Ag thin films
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Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
The nonlinear optical properties of Epoxy/Alumina Nanocomposites
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Linear and nonlinear optical properties of epoxy/ Al2O3 nanocomposites system were studied for epoxy neat and (0.5, 1.5, 3, and 5) % Al2O3 nanocomposites.The band gap of epoxy and its nanocomposites was obtained at these weight ratios. Nonlinear optical properties experiments were performed using Q-switched Nd:YAG laser z-scan system.These experiments were carried out for different parameters: wavelengths (1064 nm and 532 nm), laser intensities (0.530, 0.679, and 0.772) GW/cm2 and weight ratio of Al2O3 nanocomposites. The results showed that the band gaps were decreased with increasing the weight ratio of nanoalumina except at 5wt% and the nonlinear refractive index coefficient is directly proportional to the incident intensities while o

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Publication Date
Sat Feb 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
The impact of customer contact on operation performance Case study in the specialist Dental Centre in Al-alwia
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the researchers Sought to determine the impact of the customer contact (Within a client contact there are two times, first is the total time required to create a service and within it there is contact time while the second time is the time of client contact ؛ where means a time that records the physical presence of the customer during the process of service) on operations performance by concentrate attention on the cost (labor productivity) and quality (patient ratio to the doctor) and speed (cycle time) and flexibility (the flexibility range) , as well as ruling out variable of innovation because of impossibility to measure this variable in the Specialty Center for Dental in al-alwia due to the center is lacking of mechanisms t

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The effects of raddiation on the optical properties of GERMANIUM SELENIDE semiconductor.
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Study was made on the optical properties of Ge2oSe8othinfilms prepared by vac-uum evaporation as radiated by (0,34,69) Gy of 13 ray.The optical band gab Eg and tailing band A.Et were studied in the photon energy range ( 1 to 3)eV. The a-Ge20Se8o film was found to be indirect gap with energy gap of (1.965,1.9 , 1.82) eV at radiated by B ray with absorption doses of (0,34,69)Gy respectively.The Ea and AEt of Ge20Se80 films showed adecrease in E8 and an increase in AEt with radiation. This be-havior may be related to structural defects and dangling bonds.

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Publication Date
Fri Jun 30 2023
Journal Name
Mathematical Modelling Of Engineering Problems
Enhanced Prosthesis Control Through Improved Shoulder Girdle Motion Recognition Using Time-Dependent Power Spectrum Descriptors and Long Short-Term Memory
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Surface electromyography (sEMG) and accelerometer (Acc) signals play crucial roles in controlling prosthetic and upper limb orthotic devices, as well as in assessing electrical muscle activity for various biomedical engineering and rehabilitation applications. In this study, an advanced discrimination system is proposed for the identification of seven distinct shoulder girdle motions, aimed at improving prosthesis control. Feature extraction from Time-Dependent Power Spectrum Descriptors (TDPSD) is employed to enhance motion recognition. Subsequently, the Spectral Regression (SR) method is utilized to reduce the dimensionality of the extracted features. A comparative analysis is conducted between the Linear Discriminant Analysis (LDA) class

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Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Impact Of Means Of Support On The Intention Entrepreneurial Field Research On A Sample Of Algerian Students
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     The aim of this paper to study the effect of the implicit factors on the entrepreneurial spirit of the students of the Algerian university. Our structural model was proposed based on the model (Shapiro et Sokol, 1982) and the model (Ajzen, 1991). We tested it on a sample of 163 university students at the University of Algiers 3. The model consists of a set of variables (the intention of contracting as a dependent variable, structural and social educational support as independent variables). The results showed that educational and social support factors affect the entrepreneurial spirit of students more than structural support. The Applied Impacts are the enhancing of knowledge capacities of university stu

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Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
The Influence of RF power, pressure and substrate temperature on optical properties of RF Sputtered vanadium pentoxide thin films
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The V2O5 films were deposited on glass substrates which produce using "radio frequency (RF)"power supply and Argon gas technique. The optical properties were investigated by, UV spectroscopy at "radio frequency" (RF) power ranging from 75 - 150 Watt and gas pressure, (0.03, 0.05 and 0.007 Torr), and substrate temperature (359, 373,473 and 573) K. The UV-Visible analysis shows that the average transmittance of all films in the range 40-65 %. When the thickness has been increased the transhumance was decreased from (65-40) %. The values of energy band gap were lowered from (3.02-2.9 eV) with the increase of thickness the films in relation to an increase in power, The energy gap decreased (2.8 - 2.7) eV with an increase in the pressure and

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