Effect of Laser Surface Treatment on Some Mechanical Properties of Low Carbon Steel
Asaad
K. Hamza
author
Enaam
O.Hasuon
author
Khansaa
D. Salman
author
text
article
2012
eng
This research aims to study the effect of localized laser surface treatment onmechanical behavior of low carbon steel. Laser Cw Nd : YAG was used in thetreatment hardening of the specimens for different laser energy (2.7,3.3,4.37100J ),with time interval for the beam (10-2 sec) and the laser intensity(4500,5500,7100Watt/mm2) . Different mechanical tests were achieved Static and Dynamic on thespecimens which were surface treated .Static tests included ( Tensile test,Microhardness test) ,While the dynamic test included (Impact test ).The results show that the mechanical properties for low carbon steel H[.hxstrength by(0.9,10,25.5%) , ultimate tensile strength by(6.4,16.24,24.59%),while theincrement fracture stress by (12,17.28,34.87%),also increment in microhardness by(3.4, 5 , 23% )and toughness by (4.3,10.86,20.8 %). Some of mechanical propertiesfor low carbon steel reduce with increasing in laser energy which show in Youngmodulus (26.06,40.89,50.8%), Rigidity modulus by (25,40.5,48.99 %) , Poisson s,ratio (1.29,2.34,3.69%) .
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
271
283
https://etj.uotechnology.edu.iq/article_57264_3fb1b0f98e98f9bdfdb52ee35965dc9f.pdf
dx.doi.org/10.30684/etj.2012.57264
Study What Can be Achieved by the Lack of Flexural Strain Energy of Change for The Efficient Recovery of Novolak of The Elasticity As a Result of Fiber-Reinforcement
Rola
Abdul Khader Abbas
author
text
article
2012
eng
This study deals, with the problem of the widening expanse of time to downloadis not limited to a certain mechanical property of clear-cut, but intertwined andbranched out and became one of its aspects scientific insomnia ... Because the totalvalue of creep does not give us a firm base to judge the causes, but under certaincircumstances can be separated total distortions for sample into two recoverabledeformation and irrecoverable deformation. Therefore, the sum that in order tofacilitate the perception of mechanical we need to know the creep resiliencemodulus and may even add images to unforeseen come to know through the flexuralstrain energy , which helps to understand this mechanism in order to avoid thedangers arising from the phenomenon of creep.Generally has this study measured the ability of novolak material side by side withthe composites prepared reinforcing the novolak material, by glass fiber once andasbestos fibers once and hybrid fibers (30% fiber glass +30% fiber asbestos) again onthe absorption of elastic energy which disappear after the removal three – pointflexural stress and is know by creep resilience modulus, note that the ratio weightedmount reinforced (60%) and that the samples of various kinds attended with twodifferent ratio from the material hardened (Hexamethylene - teraamine) (HMTA), apercentage (10%) weight once and (14%) and weight again .* The practical results showed that a small fraction absorbed elastic mechanicalenergy after the first period of time from loading to be non-refundable after thedemise of the forces of bending acting on them, and this shows the extent ofaccumulation of elastic strain energy stored in novolak material over time and raisethe value of creep resilience modulus and the consequent decrease of the potential torestore the original situation after removing the stress and thus discouraged the returnof this energy absorbed .As a reference this study also to the high elastic strain energy and creep resiliencemodulus For an article novolak when compared composites as a result of the lack offiber foregoing in. This is a clear proof on the efficiency of reinforcement mechanismto be strengthened to raise the efficiency of novolak to return the energy bendingabsorbed, and study also showed that the increase the proportion of material hardened(HMTA) to (14%) lead to the devaluation of resilience modulus which confirms thesharply decreasing the accumulation of elastic strain energy to novolak material and composites, and indicative of, the positive impact of increasing the proportion ofmaterial hardened can cancel at least in part the negative impact of thisaccumulation of elastic strain energy stored in this article prepared to restoreelasticity.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
284
301
https://etj.uotechnology.edu.iq/article_57265_e2250a6f1471d0280ccae95d5afcfb40.pdf
dx.doi.org/10.30684/etj.2012.57265
Front-Wall Illumination of Spray-Deposited PbS-Si HJ Detector
Kadhim
A. Hubeatir
author
text
article
2012
eng
(n-p) PbS-Si HJ detector has been fabricated by pyrolytic spraying of PbSheterolayer onto p-type silicon wafer. PbS-side of illumination in the wavelengthrange (450-1150 nm) revealed that the quantum efficiency plateau fairly conformsto that of Si homojunction. Significant specific detectivity of about 8.5 x 1011 cmHz1/2 W-1 has been obtained at 850 nm wavelength. Signal to noise ratio revealedan optimum operation voltage at 2.5 V.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
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v.
12
no.
2012
2010
2015
https://etj.uotechnology.edu.iq/article_57242_216f76f7394f59475e85c4801a2eeb79.pdf
dx.doi.org/10.30684/etj.2012.57242
Development of the Electrical Conductivity of PEM Fuel Cell
Nirvana
A. A bud
author
Raid
K. Salim
author
text
article
2012
eng
This research is aimed to develop the electrical conductivity of PEM fuel cellthrough the using of a series of graphite plates. The effect of width, thickness of platesin addition to the current and gas flow rate (hydrogen and oxygen) were studied.Results showed that electrical conductivity can be reached to the optimum value(850Scm), when cell thickness, current and gas flow rate are 0.3cm, 8.13A and 0.6Lmin respectively.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2016
2026
https://etj.uotechnology.edu.iq/article_57243_7088516dbf71327383b47132c927ca49.pdf
dx.doi.org/10.30684/etj.2012.57243
Automatic Features Recognition for Symmetrical Shapes
Amjad
Barzan Abdulghafour
author
Mithal
Ahmed Al-Bassam
author
text
article
2012
eng
The future of computer-aided design (CAD) and computer-aided manufacturing(CAM) depends on the ability of their two processes to communicate with eachother and with intermediate manufacturing database. Therefore, the development ofa successful approach to the integration of CAD and CAM will require solution toseveral fundamental problems in planning and geometric reasoning. The firstproblem is the interface between CAD and CAM, that automatic featurerecognition is an indispensable technique to solve this problem. We address thisproblem by developing an algorithm, which is considered an effective approach toextraction and of hybrid manufacturing features of symmetrical parts. Thedeveloped algorithm is based on the syntactic pattern primitive concept supportedby production rule technique. This approach is considered a powerful tool appliedto feature recognition field for symmetrical parts.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2027
2043
https://etj.uotechnology.edu.iq/article_57244_ee4325fa8f75bcda83a4be7b0bbf71ba.pdf
dx.doi.org/10.30684/etj.2012.57244
The Exprimental Parameters Effect on The Performance of Cromer Wheel System in Airconditioning Unit
Ahmed
J .Khaleel
author
Ahmed
Q .Ahmed
author
Fawziea
M.Hussien
author
Ahmed
A.M.Saleh
author
text
article
2012
eng
The main aim of the present study is to design and test the dehumidify systemfor air-conditioning unit and testing rig to find out the performance of usingpolymer technique to control the inside conditions, that are represented by relativehumidity and temperature in testing room by using desiccant wheel (Cromer cycle),and testing the effect of some parameters which can improve the performance ofthis system. An air-conditioner unit of 2tons capacity was installed in this systemand used one type of desiccant material (silica gel) was used in this work. Twothicknesses of desiccant material and two widths (channels depth) were studied3.5mm with channel depth 5cm and 2.5 mm with channel depth 20 cm and wheelsdiameter of 90cm.Four rotational speeds for desiccant wheel were studied (36, 45,60, and 90) rph and the regeneration temperature was used to control the inletregeneration air temperature using a number of electrical heaters. The series of testshowed that, the best COP, efficiency and relative humidity control within theconditioned space was for the silica gel at thickness 2.5mm and channel depth20cm. The maximum adsorption and desorption rate was 0.5427g/kg and1.322g/kg respectively at 36 rph and (36.5 oC) regeneration temperature and thebest COP of A/C was about (5.12) at 36 rph and (42 oC) regeneration temperature.Experimentally the best sensible and total efficiency that can be achieved was(18.1%) and (17.98%) at 45 rph and (30.6 oC) regeneration temperature and(17.88%), (17.76%) at 36rph and (30.91oC) regeneration temperature. The bestlatent efficiency was (6.2 %) at 45 rph and (43.26 oC) regeneration temperature
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2044
2057
https://etj.uotechnology.edu.iq/article_57247_8a176c6b0a2932dd1205cfea8ce5af5a.pdf
dx.doi.org/10.30684/etj.2012.57247
Proposal for Designing of New BIOS Program
Hussein
Abdulameer Abdulkadhim
author
Yousra
Ahmed Fadhil
author
Noor
Abdulateef Hassan
author
text
article
2012
eng
In this paper, a proposal for designing and implementation of general BIOS program have been done. This program consider as a modified version derived from previous versions with configure and adding a new activities differs from the others BIOS programs such as learning students, help and adjusting components using mouse only (never using the keyboard) in all windows of the implemented program. Also, the program has a flexibility to add any necessary function or activity.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2058
2066
https://etj.uotechnology.edu.iq/article_57249_65f1f3d06592c02d434a08b45ed01e4f.pdf
dx.doi.org/10.30684/etj.2012.57249
Proposal for Complex AES Security using key Generator and Text Permutation
Shatha
Habeeb
author
text
article
2012
eng
Advanced Encryption Standard (AES) is a symmetric-key encryption each ofthese ciphers has a 128-bit block size, with key sizes of 128, 192 and 256 bits. The AES cipher is specified as a number of repetitions of transformation rounds that convert the input plaintext into the final output of ciphertext. Each round consists of several processing steps, including one that depends on the encryption key[1,2]. This research proposes a technique intended to make the Advanced EncryptionStandard (AES) more safe and secure. Through the generation of random key, and permutation key sites in each round, instead of the process of expanding key locations in addition to the proposed permutation the plaintext before entering the encryption and inverse permutation for resulting ciphertext.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2067
2075
https://etj.uotechnology.edu.iq/article_57252_09c966a0ce25f77230f852c1956fae84.pdf
dx.doi.org/10.30684/etj.2012.57252
Mechanical, Electrical and Thermal Properties of Polypropylene and Polycarbonate Blend Filled with Carbon Black
Fadhil
Abbas Hummdai
author
text
article
2012
eng
In this work a composite materials were prepared containing matrix of polymer blend (polypropylene 80% + polycarbonate 20%) reinforced by (carbon black) with different of weight fraction %. The specimen sheet, were obtained by hotcompression from extruded material, using single extruder operated at a temperature between (190-200)Co. The extrusion processes give homogeneous mixer through a regular selection of machine screw revolution per minute and temperature used in extrusion process. The weight fraction of the carbon blacks ranged from 0.0 up to 20 wt % with the polypropylene and polycarbonate blend. All samples related to, mechanical, thermal and electrical tests were prepared by single –extruder. By discharging a high voltage through the composite it was found that the resistivity of the composite decreased from (1.00E+09)-(1.00E+028). Carbon black–polypropylene and polycarbonate composites show significant differences from the neat blends measured in the frequency range. The study of physical test show that the thermal conductivity decreases with the increase of weight fractionfrom (0.157-0.23).
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2076
2086
https://etj.uotechnology.edu.iq/article_57257_5ad6b9d6cf4a0a16190ac684c9162b65.pdf
dx.doi.org/10.30684/etj.2012.57257
Effect of Mixing Time and Temperature on the Rheology ofWater/Oil Emulsion
Laith
S.Sabri
author
text
article
2012
eng
A study of temperature effect with a significant impact on rheology fluid, mixing time, and also volume fractions was carried out. In this study, the w/o emulsions were prepared into three volume ratios (30-70%, 40-60% and 50-50% w/o) and at mixing time (5, 15 and30 minutes) by using one type of crude oil (Kirkuk). The w/o emulsions were stabilized, then characteristics were measured. The effective viscosity of water-in-oil emulsions depends mainly on the volume fraction, mixing time and temperature, along with several minoreffects, such as shear rate, shear stress stream and viscosity of oil.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2087
2101
https://etj.uotechnology.edu.iq/article_57258_4981444df4b0a94e8e1118746babec30.pdf
dx.doi.org/10.30684/etj.2012.57258
A Study of the Spectral Properties of Rhodamine (6G&B) DyesMixture Dissolved in Chloroform
Slafa
I. Ibrahim
author
text
article
2012
eng
The spectral properties (absorption and fluorescence) of laser dyes (R6G& R B)mixture have been studied; this type of laser dye belongs to the Xanthenes family,and has been dissolved in chloroform to prepare (1*10-5, 2*10-5, 5*10-5, 7*10-5, 1*10-4M) at room temperature.The achieved results pointed out to an increase in the absorption and fluorescenceintensities with the increased concentration which are found in agreement with Beer –Lambert law. These results have been also showed an expansion in the spectral rangeof absorption and fluorescence with a noticed shift in the direction of longerwavelength.The quantum efficiency of the dissolved Rhodamine mixture in chloroform hasbeen calculated by using the same above concentration (96%, 91%, 80%, 71%, and66%) respectively. The radiative life time ( 0.21 , 0.41,0.89,1.19 and 1.48 ) ns andfluorescent life time (0.20 , 0.37,0.71,0.84, and 0.97 ) ns respectively .It has been determined that the resulting overlap between the absorption spectrum andfluorescence spectrum for(R 6G&RB) mixture is more than that shown for the everydye alone solution, therefore stock shift will be more.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2102
2115
https://etj.uotechnology.edu.iq/article_57259_8df7ef6fc56cea2d5aba4c1b362a23fa.pdf
dx.doi.org/10.30684/etj.2012.57259
A molecular Study of Azoospermia & Sever Oligospermia in a sample of infertile Males Al-Anbar Governorate
Samir
M.Khalaf
author
Adel
F.Shehab
author
Akeel
H.A.Al-Asse
author
text
article
2012
eng
Infertility is one of the major public health problems in the Arab world, as it affects about 15% of couples seeking children. in 50% of these cases, the male partner is responsible for infertility . Y microdeletions in the azoospermia factor (AZF) region are known to be associated with spermatogenetic failure. In the current study, the aim was to determine the molecular background of male infertility using tag sequence tagged site (STS) associated with Azoospermia cases . We evaluated the incidence of Y chromosome microdeletions in (100) Iraqi infertile male patients with primary idiopathic male infertility and 50 fertile males (controls) by polymerase chain reaction using 11 STSs in the azoospermia factor (AZF) region. Of the 100 infertile men, Y-chromosome Microdeletion in the AZFa , AZFb and AZFc regions were detected in (64%)cases. The pathological significance of these deletions is not clear yet or most probably belongs to environmental pollution by depleted uranium used by collision forces in Al-Anbar governorate .
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2116
2124
https://etj.uotechnology.edu.iq/article_57260_81d2e60d4f8c6a8eb82b6b6a56527940.pdf
dx.doi.org/10.30684/etj.2012.57260
Proposed Combined PTS with Clipping and Filtering Technique for PAPR Reduction in OFDM System
Ghanim
Abd AL Kareem
author
text
article
2012
eng
One of the major drawbacks of OFDM is high Peak-to-Average Power Ratio(PAPR) which can result in poor power efficiency and serious distortion in the transmitter amplifier. In this paper, the advantages of two different approaches to PAPR reduction are exploited in order to reduce the PAPR more significantly. The first approach is based on clipping and filtering which provides a high PAPR reduction at the cost of signal distortion. The second approach (Partial Transmit Sequence PTS or Selected Mapping SLM methods) results in no distortion. Theperformance of the three proposed combined methods(Clipping And Filtering with PTS scheme, SLM with Clipping And Filtering scheme, and PTS with Clipping And Filtering scheme)are evaluated on the PAPR distribution function and on the Bit Error Rate as a function of Signal to Noise Ratio in Additive White Gaussian Noise Channel. The simulation results show that the proposed PTS with Clipping And Filtering scheme provides more PAPR reduction without degradation in the BER performance as compared to the other two proposed scheme (Clipping And Filteringwith PTS scheme and SLM with Clipping And Filtering scheme). The simulation results of PAPR reduction and BER performances are simulated using MATLAB R2009a computer simulation software.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2125
2137
https://etj.uotechnology.edu.iq/article_57261_018a3b7a0e4272d34002f105aa19948e.pdf
dx.doi.org/10.30684/etj.2012.57261
Optoelectronic Properties of CdSe/Si Heterojunction
Waseem
Najeeb Ibrahim
author
text
article
2012
eng
In this paper n-CdSe/p-Si heteroj unction photodetector was fabricated bythermal-evaporation technique of CdSe thin film grown onto single crystalline Sisubstrate . The energy gap of CdSe film was estimated from transmittance spectraand found to be (1.89 eV) . The temperature dependence of Seebeck coefficientwas studied . The conductivity of CdSe thin film is n-type and the value ofactivation energy is (0.59 eV). Heterojunction properties included dark andilluminated current-voltage (I-V) and capacitance-voltage (C-V) characteristics.From I-V plot, junction ideality factor for heterojunction was calculated to be1.43, and providing information about the current transport mechanism. The linearvariation of the experimental curve C-2 vs. V is indicative of the presence ofabrupt heterojunction and it used to determine the experimental value of built-injunctionpotential Vbi . From illuminated I-V plot at different intensity levels(90,180,240) mW/cm2 , the linearity behavior of CdSe/Si heterojunction wasinvestigated .
Engineering and Technology Journal
University of Technology-Iraq
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v.
12
no.
2012
2138
2149
https://etj.uotechnology.edu.iq/article_57262_29d3cab8016c716ad192dbf2dfa51130.pdf
dx.doi.org/10.30684/etj.2012.57262
Early Detection of Disease-Viral Hepatitis Type-C Using Elman Artificial Neural Network
Ghaidaa
Kaain Salih
author
text
article
2012
eng
The problem of founding important information in complex medical images which are needed in diagnosing of diseases with the complex data considered as one of the predication problem these days, so it is necessary to find aided means for diagnosing process. Artificial neural network (ANN) is one of them. This paper deals with the designing and implementation a classification ANN module for Lever Hepatitis(class-C)or type-C which doesn’t have any vaccine these days. The different in diagnosing between hepatitis and other liver diseases is often difficult on purely clinical grounds in addition the damage to the liver causes changes in the pattern of the serum enzymes andin recent years this has led to develop disease testing and its vaccine. Elman neural networks (NN) have been applied for automated detection of various medical diseases. Like its application on blood sample tests extracted from on line microscope (like it usedin this research).That feature selection is an important issue by removing features that do not encode important data information from the images used.This helps physicians to extract features which aided them in diagnosing process. Kernal principle component analysis (PCA) is used to represent blood images as eigen-features of training images in addition to extract mathematical module for classification of it. Finally a neural network (NN) is trained to perform the typical images and classify them (diagnosing process). The produced NN system produces used a matlab package in order to design and diagnose the proposed module. The object of this system used in our work is to diagnosing lever Hepatitis type-C in samples of blood images wherever difficulties in practical experiments by finding an optimal feature from specialists whom work in laboratories.
Engineering and Technology Journal
University of Technology-Iraq
1681-6900
30
v.
12
no.
2012
2150
2164
https://etj.uotechnology.edu.iq/article_57263_0bc7eb6c3c1ed05d1858aa5042b4edf2.pdf
dx.doi.org/10.30684/etj.2012.57263