University of Technology-IraqEngineering and Technology Journal1681-690025520070525Fatigue Damage Accumulation Behavior of 2024 Al-Alloy Under The Effect of Shot Pening Tim15916918132510.30684/etj.25.5.1ENJournal Article20050424Fatigue damage accumulation behavior of 2024 Al-alloy has been investigated under the effect of varying the time of shot peening. Damage accumulation from low-high and from high- low stresses has been studied using rotating bending tests. The time of shoot peening is in the range 2-20 min. The conclusions derived from this study areUniversity of Technology-IraqEngineering and Technology Journal1681-690025520070525Adopting Small Signal Model for the Equivalent Circuit Instrumentation of a Multi-QuantumWells Semiconductor Laser17017818132610.30684/etj.25.5.2ENJournal Article20041130In this study, results of an analysis for the MQW semiconductor laser performance are presented. This analysis considers the steady-state condition and small signal modeling to introduce optical gain, charge carrier density, current and output laser power. Accordingly, a description of AC RLC circuit equivalent to semiconductor laser structure is presented in order to introduce operation and output parameters as well as achievable efficiencies. University of Technology-IraqEngineering and Technology Journal1681-690025520070525An Investigation of Elastic Buckling for Perforated Plates In Aircraft Structure17919718132710.30684/etj.25.5.3ENJournal Article20050605The present work performs mechanical buckling analyses on square and rectangular plates with central cutouts under uniaxial compressive load. The cutouts were either circular or square holes. The material of plates was the widely used in aircraft structures i.e. Al-2024 T3 aluminum alloy. The finite element structure analysis technique was used to study the effects of plate support conditions, plate aspect ratio , hole geometry, and hole shape on the buckling characteristics of the perforated plates. The well- known finite element structural ANSYS program was used to perform the calculations. Square plates with circular and square cutouts showed decays in buckling strengths as the hole sizes were increased. On the other hand , rectangular plates unexpectedly exhibited an anomalous behavior when their buckling strengths enhanced as the holes were enlarged. The plate buckling mode shape could be symmetrical or anti-symmetrical, depending on the plate boundary conditions, aspect ratio and the hole size. For the same cutouts areas, the buckling strengths of the same sized plates with square holes, University of Technology-IraqEngineering and Technology Journal1681-690025520070525دراسة تأثير الحجم الحبيبي للدقائق و درجة حرارة التشكيل على الخواص الميكانيكية للمواد المركبة ذات الأساس من البوليمر19820618132810.30684/etj.25.5.4ENJournal Article20050831This research deals with the study of the effect of adding pure aluminum powder of different sizes (106μm, 250μm,1-2mm)to novolac materials. This has been achieved by hot pressing matrix and reinforcement materials, after preparing the matrix from novolac (85%of phenol formaldhyd and 15%of hexamethylin tetra amin as hardener with the assistance of an acid).After sieving the matrix to the required particles size , a compression pressure (15Mpa) has been applied for 30 minutes as forming time, and under different forming temperature degrees ranging from75,100,125,150,200co. So their influence on the matrix characteristics and the compound material is studied.The results have shown that the addition of particles to the matrix improves to a great extent the mechanical properties, since testing deflection and hardness have shown an increase in direct proportion to increase in the grain size of the additive particles, which work as nucleas to increase the cross linking of the matrix.The tests show the best forming temperature is 150co which gives best properties. University of Technology-IraqEngineering and Technology Journal1681-690025520070525مساهمة في دراسة العلاقة بين التداعي والانتفاخ مع اجهادات مص التربة20722418132910.30684/etj.25.5.5ENJournal Article20060402This research aims to study the role of soil suction and clay minerals on volumetric changes of a collapsible soil selected from Hawy Al-Kanissa area in Mosul city. The effect of low and highly plastic clayey soil as an additive to this soil has been investigated. The main results show the optimum clay content for soil to collapse decreases with the increase in the plasticity of soil. Swelling percent and pressure increase with the clay content, plasticity of soil and dry unit weight. <br />Soil suction was also studied for collapsible soil with different clay contents. The results show linear relationships for all types of soil. Soil suction also increases with plasticity. Thus soil (CH) gave more suction than soil (CL). However, dry unit weight had little effect on soil suction, which was frequently negligible. Addition to that, statistical models between soil suction with collapse and swelling potential were obtained with an acceptable correlation coefficient. University of Technology-IraqEngineering and Technology Journal1681-690025520070525ﺇﺩﺍﺭﺓ ﻭﻤﻌﺎﻟﺠﺔ ﺍﻟﻨﻔﺎﻴﺎﺕ ﺍﻟﺼﻠﺒﺔ ﻓﻲ ﺒﻌﺽ ﻤﺴﺘﺸﻔﻴﺎﺕ ﻤﺩﻴﻨﺔ22524618133010.30684/etj.25.5.6ENJournal Article20050601<br />Hospital solid waste management is one of the most neglected parts of the managerial process in Baghdad. This research has been done to evaluate the actual state of this system in some hospitals in Baghdad as a case study and to find out thUniversity of Technology-IraqEngineering and Technology Journal1681-690025520070525Image Denoising Using Hybrid Transforms66968218133110.30684/etj.25.5.7ENWalid AminMahmoudRaghad AladdinJassimJournal Article20050724In this paper a new family of transformation for image denoising is<br />presented, Multiridgelet and Walidlet transforms, which have been proposed<br />as alternatives to Discrete Wavelet and Multiwavelet transforms.<br />Walidlet transform is an intelligent tool for solving image processing<br />problems such as image denoising with straight edges, the general algorithm<br />of image denoising using discrete multiwavelet transform is introduced, then<br />followed by the general algorithm of image denoising using Walidlet<br />transform that is proposed here in order to achieve better results than that for<br />Walidlet thresholding, finally, a comparative study is presented to show the<br />differences between a mentioned algorithms.University of Technology-IraqEngineering and Technology Journal1681-690025520070525Measurement of Thermooptic Coefficient in Lead Sulfide Using Laser Single-Beam Scanning Technique68368918133210.30684/etj.25.5.8ENBan A.M.BaderOday A.HamadiK. YousifAfnanJournal Article20051130In this work, the single beam scanning technique was employed to express<br />the nonlinear interaction between laser radiation and semiconductor material<br />(lead sulfide) as well as to determine the thermooptic coefficient of the<br />material (lead sulfide). Direct measurement, low cost and reliability are the<br />main features of this technique. The value of the thermooptic coefficient was<br />determined to be -5.8x10-5K-1 for PbS thin film. Due to authors review, this is<br />the first attempt in Iraq to measure such parameter in semiconductor thin<br />films.University of Technology-IraqEngineering and Technology Journal1681-690025520070525Study of Electrical Properties of p-PbSe/p-Si Heterojunction69069518133310.30684/etj.25.5.9ENUday MuhsinNayefJournal Article20060425Electrical properties of p-PbSe/p-Si heterojunction detector have been<br />investigated. The electrical properties under dark condition show a rectifying<br />behaviour with low rectification factor, and exhibits soft breakdown reverse<br />current.<br />C-V characteristics suggest that the fabricated diode was abrupt type, built<br />in potential determined by extrapolation from 1/C2-V curve to the point (V=0)<br />and it was equal to (0.49V).<br />Results of I-V characteristics under illumination conditions with reverse<br />bias voltage exhibit linear behavior with no saturation limit.University of Technology-IraqEngineering and Technology Journal1681-690025520070525Photonic Devices Based on Porous Silicon Layers69670118133410.30684/etj.25.5.10ENUday MuhsinNayefJournal Article20061114The optoelectronic properties of (Al/c-Si) and sandwich structure type<br />(Al/PS/c-Si/Al) were reported. The nanostructure porous silicon is obtained by<br />photochemical etching without applying electric field. The photosensitivity of<br />(Al/PS/c-Si/Al) structure is determined by porous layer photoconduction.<br />Maximum spectral sensitivity of the porous layer is changed from (575-<br />610)nm depending on preparation condition.