2024-03-29T18:10:49Z
https://etj.uotechnology.edu.iq/?_action=export&rf=summon&issue=2331
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Effect of cooling rate of steel ( 25 Cr Mo4 ) on its hardness and microstructure
Jassim
Khadir
In this work , structural low – alloyed steel (25 Cr Mo4 ) was melted in mediumfrequency coreless induction furnace of (60) kgs . capacity , lined with highalumina lining powder .Samples of disc shaped (Ø25- Ø30) mm and about (10) mm thick ,for spectro –analyzing and cylindrical parts (Ø10×100) mm, were poured to manufacturedilatometric specimens by machining to the required standard dimensions of (Ø5.5×50) mm. Testing of (12) specimens by electronic dilatometer type ( 402) ,using different cooling rates , enable getting results of hardness andmicrostructures Tests showed that ferritic structure with slow cooling i.e.( 0.1 ,0.2 and 0.5) ˚C /min .was obtained –(hipoeutectoid). While pearlite started with(1.0) ˚C /min .Cooling rate , and full pearlitic appeared by (10.0) ˚c /min .Bainitic structure , started with ( 20.0) ˚C /min .cooling rate together with pearlite ,reaching full bainitic by cooling with (100) ˚C /min.By oil guenching (i.e about 120 ˚C / sec .) and by water guenching ( i.e about 400˚C/ sec.) [ 8] martensitic structure was achieved. Those transformations in thestructure was accomplished with increasment of Vickers hardness values from (175) HV with ( 0.1˚C /min ) cooling rate to ( 579 ) HV with water guenching . Thoseresults enable the choosing of suitable cooling rate ( cooling medium) to obtain therequired hardness and microstructure of this steel
2009
08
01
348
363
https://etj.uotechnology.edu.iq/article_38417_a61bf362f245064961b1ec7d53b618c2.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Reliability Measurement for Rotary Kiln Cement Kubaysa Factory
Sawsan
Abd-Ali
Saleh
Fendi
Satar
Abdul-Mutalq
"Reliability" is one of engineering indicators for describing theperformance of an item or system by probability functions. Reliability is defined asthe probability that an item or system is capable of performing, its intendedfunction in a specified time under given working conditions. Modern industry haveproperty of contrast and fastness of products development, so that the high coststhat occur because of failure machines due to failure, Therefore analysis reliabilityis an important factor from point of view of the factory managers and the costumer.This research focuses on studying and evaluating the reliability of one ofproduction system factory as a basis to study the reliability of systems and theways of calculate it, which consist of:A) Failure Data collection .B) Failure representation, simulation and drawing graphically the histogram andprobability plot in order to calculate Time To Repair TTR and TimeBetween Failure TBF.C) Calculate the β-value of weibull distribution for the plant.D) Analyzing the charts to determine the age stage from parts and to calculatethe optimistic prediction maintenance time.E) Analyzing the effect of failure mode in order to calculate the Risk no.estimation.Data analysis has been done with support a computer aided program. Itsclear from the analysis of the data of the plant for Kiln and some components ofdepartment, are in the third (last stage) of their cycle life, which is the wear-outand aging stage . This is due to the β-value of weibull distribution. Which was β=3.87 so that we focus more on the analysis's of their data as a case-study for thefactory.
2009
08
01
364
380
https://etj.uotechnology.edu.iq/article_38428_bcf9c396b6d5da6b2840371e0f211bca.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Night Illumination Design on Building aid the Architectural Creativity
Zainab
Raouf
Rana
Mahdi
Recent trends in night illumination designs for building have experienced specialroles in the architectural compositions. These roles were the prime factors in enhancingthe characters of a building at night and concentrating on the building’s special detailsand functions thru the definition of its internal and external spaces. The process ismainly teased on two levels; The mental and the practical. Which will ensure thecontinuity of spaces and the sustainability of its parts within the natural surrounding.Sometime, equal in effect to day light, conditions, if not more effective in showing themain creative features of the artifact.The crux of the problem in the study is represented in the un-ability to define orexplain the full extent of the role of the night illumination design on buildings, withinthe frame of the two levels of the process; i.e.: Mental and practical. Hence, the aim ofthe research can be identified in the attempt to put down clear dimensions in theprocess for achieving complete architectural creativity in night illumination designs ofbuildings.The research indicated to the effectiveness of night illumination designs onbuildings in achieving the dominance of its features on the building, then it becomepossible to draw some conclusions for the study.
2009
08
01
381
393
https://etj.uotechnology.edu.iq/article_38447_23216741fa852d1abb81643186613867.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Performance and design changes accompanying the replacing of an old cooling fluid(R12) with one which is safe on the Ozone layer ( R134a) in the cooling system of a small water cooler
Mohammed
Jabal
Due to the spreading of cooling equipments that works with old coolingfluids(Freon) in the community,and because of the bad effects of these (Freon)incase of their spreading on the Ozone layer and the thermal enclosurephenomenon.It was necessary to provide theoretical and practical studies andresearches on data bases dealing with the field of possibility to replace this kind ofcooling fluids with those that is safe on the Ozone layer and thermal enclosurephenomenon with the least possible costs.this research included a practical study toappreciate the performance of a small water cooler(0.5 liter/hour)which submittedto a number of parameters of design changes that were possible with the least ofcosts , this were included by replacing the old cooling fluid that has bad effect onthe Ozone layer(R12)with one that is safe on the Ozone layer(R134a).In addition toassist the work by conducting several practical procedures on each change on thewater cooling circulation in order to reach the most precise results. Thetemperature of the water that is supplied to the consumer was considered as well astemperature of the compressor as a criterion to appreciate the water coolerperformance with recording all other changes that are possible to compare with inthe results schedule.
2009
08
01
394
407
https://etj.uotechnology.edu.iq/article_38517_0f7a36da52ab0d73c33865e578b4b931.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Effect of Zirconia Addition on Some Physical and Mechanical Properties of Porcelain
Mohammed
Al-Taie
Fadhel
Jiyad
Hussein
Jaber
This research includes the study of the effect of zirconia (ZrO2) additionin a different weight percentages (5,10,15,20)% to porcelain samples formedfrom (Duekhla Kaolin, Ardima Sand, Feldspar Potash and CalciumCarbonate). We studied effect of zirconia addition on some physical propertiesas (Linear shrinkage, bulk density, apparent porosity and water absorption)and mechanical properties as (Vickers hardness and indirect tensile strength).The results shown that the zirconia addition in a percentage not increase(10%) have been enhanced the physical and mechanical properties ofporcelain samples especially in indirect tensile strength.
2009
08
01
408
416
https://etj.uotechnology.edu.iq/article_38549_d64a261b65ef43fc68b53b111d574ade.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Determination of Yield Loci for (Al-2%Cu) sheets
Abbas
Ahmed
This study concerns on the plastic behaviour of (Al-2%Cu) sheets undersimple tension, plane strain tension and balanced biaxial tension. Experimentalyield loci were extracted based on the constant strain energy theory, comparisonswith the proposed two yield criterion after R. Hill , showed that the experimentalyield loci does not follow very well the old yield criterion, but it can be fitted betterwith the new yield criterion. The determined value of ''M'' in the new yieldcriterion were ( m = 1.85 ).
2009
08
01
417
422
https://etj.uotechnology.edu.iq/article_38569_970165b6c948e6777f4f58a78a2d77f0.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
A Block Compression Method for Fingerprint Image Storing
Salwa
A. Al-alagha
Storage of fingerprint image databases needs allocation of huge secondarystorage devices. To reduce the increasing demand on storage space, efficient datacompression techniques are badly needed. In addition to that, the exchange offingerprint images between governmental agencies could be done fast. Thecompression algorithm must also preserve the original information in the originalimage. Image compression is the application of Data compression on digitalimages. In effect, the objective is to reduce redundancy of the image data in orderto be able to store or transmit data in an efficient form. It involves reducing thesize of image data files, while retaining necessary information. The reduced file iscalled the compressed file and is used to reconstruct the image, resulting in thedecompressed image. The original image file, before any compression isperformed, is called the uncompressed image file. This paper is concerned withcompression method of fingerprint image without losing the important features ofthese images (lossless method), by using (2 × 2), (3 × 3) Block CompressionMethod. This proposed method done by compressing the fingerprint (FP) image,and decompressing the image for the twice previous methods. And then comparethe result which come from experimental results for (size of image, quality ofimage, thickness of curve), and find the relationship between them.
2009
08
01
2165
2179
https://etj.uotechnology.edu.iq/article_38213_4204c67baa41f57fbb8ee8f0b569a986.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Partition Method for Solving Boundary Value Problem Using B-Spline Functions
Bushra
E. Kashem
This paper is concerned with the approximated solution of linear two-pointsboundary value problem (LTPBVP) using Partition method with the aid of B-Splinefunctions as basis functions. The result of this method is compared with the exactsolution. Two numerical examples are given for conciliated the results of this method.
Boundary Value Problem
linear two
points boundary value problem
Spline function
2009
08
01
2180
2188
https://etj.uotechnology.edu.iq/article_38221_e9d2e4ea0f683f9cfe167566169500e4.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Secure and Energy Efficient Key Management Protocol for Ad hoc Sensor Network
Dhafer
R. Zaghar
Bassim
Abdulbaki Juma
Yaarob
M. Nafel
Recent advances in wireless communications and electronics have helped to develop sensor nodes which are low-cost, low-power, multifunctional, small in size and communicate in short distances. These tiny sensor nodes, which consist of sensing, data processing, and communicating components, leverage the idea of sensor networks. Ad hoc sensor network is a multihop network made of hundreds of sensor nodes. This Paper presents a proposed secure and energy efficient decentralized key management protocol. The proposed protocol combines three schemes; key establishment, key update and new node addition scheme. The energy consumption of the proposed key management is analyzed and compared with those of the formal protocols. The analysis shows an advantage in term of energy consumption over the previous work.
Recent advances in wireless communications and electronics have helped to develop sensor nodes which are low
cost
low
power
multifunctional
small in size and communicate in short distances
These tiny sensor nodes
which consist of sensing
data processing
and communicating components
leverage the idea of sensor networks
Ad hoc sensor network is a multihop network made of hundreds of sensor nodes
This Paper presents a proposed secure and energy efficient decentralized key management protocol
The proposed protocol combines three schemes
key establishment
key update and new node addition scheme
The energy consumption of the proposed key management is analyzed and compared with those of the formal protocols
The analysis shows an advantage in term of energy consumption over the previous work
2009
08
01
2189
2204
https://etj.uotechnology.edu.iq/article_38230_65d2f047d57b1ff2c2f3c1133ddad5f2.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Studying Curve Interpolator for CNC System
Abbas
M. Jabber Al-Fnzi
Laith
A. Mohammed
Maan
Aabid Tawfiq
This thesis focuses on developing algorithm to calculate best length line segments in (u) and (w) directions. By of tool paths for free form surfaces based on the required accuracy of the manufactured part, which is represented by mathematical curves and surfaces. Bezier method was used to apply the proposed algorithms. The proposed algorithms consist of two parts; the first part is to calculate the better length line segment in (u) direction between cutter contact points (CC), the second part is to calculate the better line segment in (w) direction depending on the type of surface, cutter radius, tolerance and height scallop being given. The algorithms are applied in production field such as design of extrusion dies using three types of curve interpolation such as approximation cubic Bezier, interpolator Bezier and compound-CRHS profile die. In this paper, the manufactured parts are machined using a 3-axis CNC milling machine. The machining operations are simulated using SURFCAM software depending on the different interpolation techniques mentioned. An evaluation test is applied to the three interpolation methods based on Finite Element Method (FEM) using ANSYS 9.0 software to expect the strain and force required to extrude billet through the dies which are designed using the three mentioned interpolation methods. The G-code programs have been implemented on 5-axis CNC machine (Okuma VH-40-HS dynamic machine), the sample material is (cibatool) and the machining process is achieved without a lubricant at the Protoshop Oy in Helsinki/Finland.
Curve Interpolator
CNC System
Bezier technique
CAD
Gcode
2009
08
01
2205
2222
https://etj.uotechnology.edu.iq/article_38234_a21a0dee60c86c0c6b605fdc285e4744.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Electrical And Thermal Properties Of Epoxy Resin Filled With Carbon Black
Adnan
A. Abdul Razak
Najat
j. Salah
Waffa
Abdul Kazem
Thermal and electrical conductivity of an insulating polymer can be achieved bydispersing conducting particles (e.g., metal, carbon black) in the polymer. The resulting materialsare referred to as conducting polymer composites. Electrical and thermal properties of epoxycarbonblack composites were studied in this work. The weight fraction of the carbon blacksranged from 0.0 up to 20 wt % with the epoxy resin. By discharging a high voltage through thecomposite it was found that the resistivity of the composite decreased. Epoxy-carbon blackcomposites show significant differences from the neat epoxy resin measured in the frequencyrange. Conductivity percolation threshold was found when carbon blacks is added in the range of1 and 2 wt%. It was found that the epoxy/ carbon black composites have better thermal propertiesthan the neat epoxy.
thermal conductivity
electrical conductivity
carbon black
Epoxy
2009
08
01
2223
2232
https://etj.uotechnology.edu.iq/article_38277_9a8650bc0b2f800bb2ee986b54fe308f.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Environmental Effect on Fatigue and Lifetime of Silica Optical Fibers
Khalid
Sadiq Rida
Tairq
AbdualWahab
Fiber optics as a transmission lines using for transmitting the signals and datainformation at minimum losses. It is using with modem communication which has thehigh immunity to' electromagnetic interference for transmitting the information, lightweight, low cost, no corrosion , safety because the electric nature which eliminates thespark hazard , wide band width (more channel can be transmitted), low signalattenuation than other propagation systems . It is using the light as a carrier formodulation signals information (l013 – 1014 ) HZ comparing to radio frequencies of(l06 – 109) Hz. Light sources as light emitting diodes (LED) & light Amplification bystimulated emission of radiation (LASER),each one using with proper type of fiberwhich are multi mode (step index), Graded index , single mode. Signal strength losscan occur for several reasons, such as: Attenuation, Rayleigh scattering, fresnelreflection , cracks , connector loss, splice loss…....For the strength and fatigue of fused silica optical fiber on the environmentalparameters temperature, humidity and PH (chemical acid, neutral or alkaline). It isshown that the stress corrosion parameter (n) is not a constant but depends on thenature of the environment. Further, different kinetic forms for the stress corrosionkinetic lead to different interpretations of experimental results? Since life timepredictions are very sensitive to the value of (n) and the kinetic form it is important toknow which form is correct. It is shown that the empirical power law form that isalmost exclusively used by the fiber optics industry provides a good fit to fatigue datafor high strength fiber, but an exponential form provides a more self- consistentdescription of fatigue in different environments . From our research the followingresults are:1. Life time of the optical fiber (silica) obviously affected by the environmentalclimate. The fatigue at the fibers affected by the presence of the chemical materials;(according to that types and concentration) affected directly to the concentration ofthe fiber starting from the external surfaces to the clad and then to the core whichhappening the cracks and these cracks increases continuously by the affect of thatmaterials. That obviously by equation research (part 2).2. the effects of stress or high weight on fiber may be happen the bending or a smallbend inside the fiber then dispersion of the light signal will be take place, then thereflection way cannot becomes write, or cracks can be happens.3. The effects of continuously humidity on strength of the fiber (according to the bellyband),relative fatigue be occurs, and that affected to the construction of fiber.(Table No.1).4. Effected of PH (concentration of hydrogen) on the strength and fatigue of the fiberfollows to the faster fused silica. As we know the limit of PH generally start from(1-14) as a number (acid, passivity or neutral) the No.7 at the middle neutralconcentration of Hydrogen ions will be basic, under to (7) will be acid. Theequations and Fig. 1 noted that.5. The effected of temperature on the strength and construction of the fiber lead tofatigue or fused silica (Eq.9) or increasing of the hardening, then lost the flexibilityand then may be broken or cracks appears on it which lost the specification.
2009
08
01
2233
2248
https://etj.uotechnology.edu.iq/article_38294_582cff5e3cf30a8680e573cae91982e1.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Multidimensional Graphics Implementation Using DirectX API Class Library
Jumana
Basheer Muhammed
Anaam
s. Nasser
Several techniques or capabilities are provided by DirectX, each of whichcan add effects on the designed graphics by using special functions in theapplication or program that written to design that graphics. Some of thesecapabilities are that, Lighting, Rotation, Texturing, Fog, Environment Mappingand Stencil Buffer capabilities.In this research, implementation of two capabilities are produced, the firstimplementation is of the Texturing capability and show several states of texturingby using variables values of tu and tv texture coordinates.The second implementation is of the Environment Mapping capability whichshows how a shiny teapot is rotated and only one face of the skybox is reflected byit.DirectX can be written in many programming languages, such as C, C++,Visual C++, and Visual Basic.When using the DirectX capabilities in many applications, not all cardssupport all that capabilities at the implementation time, some of these likeLighting, Rotation and Texturing capabilities can be implemented with 64-MegaByte VGA cards, but others like Fog, Environment Mapping and Stencil Buffercapabilities are implemented with 128-Mega Byte and over.
DirectX
DirectX Capabilities
Texturing Capability
Environment Mapping
2009
08
01
2249
2258
https://etj.uotechnology.edu.iq/article_38299_fef6f68bebdba1e47e4df6e63aef2e05.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Taguchi Approach to Optimize Pack Aluminization Parameters in Carbon Steel Using MINITAB13
Abbas
Khammas Hussein
Pack aluminization has been rapidly developed and widely used in many fieldsdue to its superior properties of coating. Surface is the only part of the componentwhich has to coexist with external environment. Majority of engineering failuresoriginate from the surfaces and components degrade in service leading to failures suchas fatigue, wear, corrosion and oxidation. The present study deals with the surfacemodification of steel base through diffusion of aluminium by aluminium packcementation for improving wear and corrosion resistance. The material chosen forstudy is medium carbon steel. Effect of varying weight percentage (wt.%) of halideactivator (NH4Cl) at different diffusion temperatures and times on the microstructureand microhardness of aluminized specimens was studied. Taguchi robust designtechnique using MINITAB13 was used to rank several factors that may affect themicrohardness and microstructure in order to formulate the optimum conditions. TheTaguchi orthogonal array L9 (33) was used for experimental design with three level ofconsideration for each factor. The respone (Microhardness) was analyzed based on theTaguchi’s signal-to-noise ratio. The use of 4%wt. of (NH4Cl) at 5hr and diffusiontemperature of 700oC seems to be the optimum condition, where the surface hardnesscould be increased to 1000Hv when aluminized. X-Ray diffraction studies have beenconfirmed the presence of aluminides in the surface layer, which could be instrumentalin the significant increase in the surface hardness.
Pack Cementation
diffusion
Taguchi method
Taguchi orthogonal array
2009
08
01
2259
2272
https://etj.uotechnology.edu.iq/article_38306_b9f7b5ecb85913acd6974e673e821232.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
A Comparison Between The Wear Rate Behavior Of Polyester Reinforced By Glass And Kevlar Fibers
Jamal
Jalal Dawood
In this research the wear rate of the polyester reinforced by chopped glassfibers and chopped Kevlar fibers with length (1-2.5 mm) and weight fraction (4, 8, 12,16 WT %) has been investigated. A Pin -on- Disc wear testing machine of variablespeed has been used. Flat against flat sliding surfaces under variable workingparameters conditions have been tested.The results of flat sliding surfaces show that the wear rate of the specimensdepends heavily on the working condition. It increases with the increase of the loadand sliding speed, and the wear rate decreases with the increase of the weight fraction.The results also show that the wear rate for polyester reinforced by Kevlarfiber was less than the polyester reinforced by glass fiber. The optimum value of wearrate was (2.75*10-6 mm3/mm) happened at weight fraction (16 WT %) when reinforcedby Kevlar fibers.
2009
08
01
2273
2285
https://etj.uotechnology.edu.iq/article_38312_32bd5efe6d079149cf65f3cbb062839b.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Physical Properties of MOS Porous Silicon Detector Fabricated under RTO Method
Alwan
M. Alwan
Wafaa
K. Khalaf
Narges
Z. Abdulzahra
In this research we studying the sensitivity of a porous silicon photo detector, wefound it improved through rapid thermal oxidation processes. Under our optimumpreparation conditions, photocurrent can reach about 3408 μA (under power density 100mW/cm2 tungsten lamp illumination) and dark current is about 300μA(at reverse bias of 5V).
Photo detector
porous silicon
rapid thermal oxidation
2009
08
01
2286
2291
https://etj.uotechnology.edu.iq/article_38320_076f079c2bef9274fc349fa1d897d70b.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Comparison Study between the Use of Plastic and Concrete Pipes for Redesign and Reconstruction of Sanitary Sewer Network in Baghdad City (Hay Al Karadda –Sections 903-905)
Shaimaa
Taleb Kadhum
Over the recent years, the emphasis on sewerage has increasinglyswitched from provision of new services to maintenance of existing service atacceptable levels. As a consequence the need is now to rehabilitate existingsystems rather than construct new ones.The common methods of rehabilitation consist lining of the sewer pipesand that was out of the question since it decreases the diameters of the alreadyunder size sewer lines.So that, hence, it was concluded that the best method for rehabilitating theexisting system was by total replacement of the undersize sewer lines. This shouldbe done using sewer pipes with better quality material, such as PVC, GRP or firstclass concrete pipes.Modern water and wastewater pipe is either organic or inorganic incomposition. Today's organic pipe is made of petroleum-derived plastic, whichcontains preservatives, antioxidants, and stabilizers to slow down the gradual lossin strength that occurs with organic materials[1].So that redesigned the existing sewer system in AL-Karadda districtwithin the city of Baghdad by computer with the use of QBasic language. Thedesign consist concrete pipes in once and plastic pipes in other to find the best.Based on the results, it was concluded that the plastic pipes neededgradient (Smin) less than concrete pipes (0.004 m/m for plastic, 0.005m/m forconcrete), the max. soil cover for plastic pipes was equal to (3.59 m) while forconcrete pipes it was equal to (4.25m).In addition the network redesigned on themin. commercial concrete pipe diameter equal to (200mm) while for plastic pipesequal to (250mm) and that will increasing the capacity of the network.
Comparison
plastic pipe
concrete pipe
redesign
sanitary sewer network
2009
08
01
2292
2304
https://etj.uotechnology.edu.iq/article_38333_6ee8c3fe69d9973b60e2e2f2fd36e49d.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Analysis and design of PID Control System for Active Magnetic Bearings
Adil
H. Ahmed
Thamir
M. Abdul Wahab
Active magnetic bearings (AMB) are unstable by their nature and are used in veryhigh-speed applications, therefore the design and implementation of a suitable control systemfor such devices requires extensive investigation. In this paper the AMB control problem istreated and design method of proportional plus derivative plus integral (PID) control system isproposed using the two degrees of freedom method. The designed PID control system issimulated and tested using MATLAB/Simulink, and some practical effects are investigated
Active Magnetic Bearings AMBs
feed back control
simulation model
2009
08
01
2305
2320
https://etj.uotechnology.edu.iq/article_38382_583369a02ee2f643acd95cc15b622f44.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Boundary Element Analysis of Capped Pile Groups
Kais
T. Shlash
Mohammed
Y. Fattah
Madhat
S. Al-Soud
The boundary element method (BEM) has become one of the most powerfulnumerical techniques which has already established itself within the scientificcommunity. The most striking feature of this technique is that, in principle, only theboundaries of the region being investigated have to be discretized, which thereforeleads to many fewer discrete elements than any scheme requiring internal subdivisionof the whole body. This means that the number of unknowns is reduced dramatically,especially for 3D problems, as the unknowns occurred only on the boundary of theproblem.This paper is devoted to make use of the boundary element method (BEM) as apractical problem solving tool to analyze a soil - structure interaction problem. Theprogram (MRBEM) is adopted in this study for the analysis process. It is a generalpurpose boundary element method program for solving elasticity and potentialproblems with multiple regions. This program is written by FORTRN-90 language anddeveloped during this study to solve a three dimensional problem represented by agroup of piles. The results were compared with those findings in some experimentaland theoretical researches and good agreements were obtained.It was found that when using the BEM in the analysis, the stresses anddisplacements need only to be calculated where the details of interest occur on theboundary or are localized to a particular part of the domain, and hence an entiredomain solution is not required. Moreover, boundary conditions at infinity can bemodeled exactly without the need to extend the region a long distance away or to applyartificial boundary conditions as a result to the arbitrary truncation of the outer region.
Boundary element
pile group
pile cap
2009
08
01
2321
2334
https://etj.uotechnology.edu.iq/article_38395_ff593bf17ae81558f92d1ca2b0140387.pdf
Engineering and Technology Journal
ETJ
1681-6900
1681-6900
2009
27
11
Growth Kinetics of Chemically Deposited CdO Thin Films
Selma
Mohammed H. Al-Jawad
Hadia
Kadhim J.Alogili
In this work CdO films were prepared by using chemical bath depositiontechnique where the cadmium nitrate salt was used as a source of cadmium ions.The effect of different bath parameters has been considered in this work, namely,cadmium ion concentration, deposition time, temperature of solution and pH value,on the rate of deposition and terminal thickness. Annealing process in air attemperature 573K° and time of 15min. are carried out for the conversion ofcadmium hydroxide film to oxide film. X-Ray diffraction technique has confirmedthe formation of cadmium oxide (CdO).
CdO
thin film
Chemical bath deposition
Growth Kinetics
2009
08
01
2335
2344
https://etj.uotechnology.edu.iq/article_38402_bed0bc81bed21c54aec0c9d0a1dda08e.pdf