ISSN: 2521-9154

Volume 20, Issue 1

Volume 20, Issue 1, Winter 2017, Page 1-310

Experimental Investigation of a Temperature Change inside Pneumatic Cylinder Chambers

J. M. Hassan; D. Ghanim; N. B. Hamandy


The investigation of the existence of a temperature change with pressure inside the pneumatic cylinder chambers during the charging and discharging strokes in the pneumatic cylinder is experimentally demonstrated. Three different variables (pressure, piston displacement and temperature) were measured in this work while operating with a servo pneumatic system and a discussion of the relationship between these variables was presented. The cylinder used has a piston diameter of (0.05m), piston rod diameter (0.02m) and a stroke length of (0.2m). The results show a temperature rise of 23 K above atmospheric temperature at chamber (1) while air compressing and a temperature drop of 17 K below atmospheric temperature at chamber (2) while air expansion and measures other temperature changes also.

Fluidics Thrust Vectoring Using Co-Flow Method

Ali Abdul Almuhsen Al-Asady; Ahmed Mujahid Abdullah


Computational and experimental investigations of thrust vectoring using co flow method had been carried in the present work. The experimental investigation included design and construction of rig with rectangular duct with aspect ratio (4.4) in order to investigate the effect of various geometric variables on thrust vectoring angle. Set of experiments tests carried out over the mass flow ratio ((ms) ̇⁄(mp) ̇ ) range 0 ≤ (ms) ̇⁄(mp) ̇ ≤ 0.23, gap height h/H= (0.0294, 0.0588, 0.088 and 0.1176) and coanda surface diameter Φ/H= (1.176, 2.353 and 3.529).
Load measurements were obtained using four load cells. The computational investigation involved a 3D numerical solution by FLUENT 6.3.26 Software for some of experimental cases. The results show that the increase in secondary jet blowing rate lead to increase the jet vectoring angle, there are three zone can be observed, dead zone appears at low mass flow ratios, then followed by control region in which continuous thrust vector control can be achieved followed by a saturation region. The coanda surface diameter determines the length of the dead zone, which a small coanda surface used for coanda effect resulted in a prolonged dead zone range and the secondary gap height to the primary gap height had inverse relation with jet vectoring angle. The investigation shows that both the experimental and computational results obtained follow a similar trend line.

Effect of Different Tool Geometries in Friction Stir Welding of AA 2024-T3 using Design of Experiments

Moneer H. Al-Saadi; Sabah Khammass Hussein; Mursal Luaibi Saad


In this work, Aluminum alloy (AA2024-T3) was welded by friction stir (FSW) method using different pin profile design types; straight cylinder, threaded cylinder, tapered cylinder hexagonal, square, and threaded taper. For each type, a flat and concave shoulder was used, as well as, the welding process was single and double. The results of mechanical tests are analyzed using design of experiments method (DOE). The best and weaken mechanical properties (tensile strength, bending force and hardness) are observed when the welding is achieved by hexagonal and straight cylinder pin profile respectively. A concave shoulder gave higher mechanical properties as compared with flat shoulder. The change in welding process type presented a sensible effect. Nugget zone hardness is higher than that of base metal for all specimens. The optimum hardness result is recorded by hexagonal pin with concave shoulder profile.

Parametric Optimization of Pulsed Nd:YAG Laser Lap Welding of Stainless Steel ASTM A240/ 316L with Carbon Steel ASTM A570/Gr30

Thaier A. Tawfiq


This work describes seam welding process using dissimilar ferrous metals by pulsed Nd:YAG. The main objective of this work is to achieve the best welding conditions. This imposes careful selection for the welding parameters and inevitably the well design of experiment (DOE). Sheets of ASTM A240/316L stainless steel to ASTM A570/Gr30 carbon steel all of 0.5 mm in thickness were lap welded. Different pulse energies or the related peak power, pulse duration, pulse repetition rate, and welding speeds were used. Moreover, different welding speeds were controlled by the employed manipulator. The laser beam spot diameter and the standoff distance were fixed. Experimental results are supported by the computational 2D and 3D models. In this article response surface methodology (RSM) was applied to design the experiment and obtain the best parameters through a set of mathematical models that define the weld characteristics. The results show that the best joint in term of joint strength is obtained at 31.9 J pulse energy (related to 5.5 kW peak power and 5.8 ms pulse duration), power density of 1.43×106 W/cm2, 1.5 Hz pulse repetition rate, and 0.5 mm/s welding speed.

The Effect of Improvement Surrounding Soil on Driven Pile Friction Capacity

Mohammed M. Salman; Abdulaziz Abdul Rassol Aziz


There is very close relation between the pile capacity and surrounding soil conditions . In cohesionless soil the pile effected on surround soil by compact loose ,cohesionless deposits through a combination of pile volume displacement and driving vibrations .the pile foundation usually designed to exceed the weak soil to the firm deposit .in this study we shall try to improve the weak soil surround the pile and observe the effect of improvement on pile capacity for driven pile.
The improvement suggested in this study is compacting for surrounding soil . for this purpose we prepare testing program by selection two types of sand soil one as the origin soil and the other as improving soil (soil will be compacted and replace surround pile model) . pile model prepared for this purpose is consist of reinforcement steel bar covered with cement mortar , 50 kN automatic electromechanical compression machine was used for testing load- settlement test on pile model. The Testing procedure includes changing the diameter of soil compacted around pile model and execute the load settlement test and compare the results.

Gypseous Soil Improvement by Silicone Oil

Ali Nasir Ibrahim; Tom Schanz


Gypseous soils are usually stiff when they are dry especially because of the cementation of soil particles by gypsum, but great loss in strength and sudden increase in compressibility occur when these soils are fully or partially saturated. The dissolution of the cementing gypsum causes high softening of soil. The problem becomes more complicated when water flows through the gypseous soil causing leaching and movement of gypsum. This study examines the improvement of gypseous soil properties using the Silicone oil to minimize the effect of moisture on these soils. This study was conducted on artificial gypseous soil (mixture of 30% Silber sand & 70 % Pure Gypsum) treated with silicone oil in different percentages. The reason for use the silicone oil as an additive to study the gypseous soil properties is due to the leakages of oil products from oil refinery in north of Iraq build on gypseous soil, this oil products infiltrate to the foundation soil of the refinery building facilities.
The results showed that the Silicone oil is a good material to modify the basic properties of the gypseous soil of collapsibility and shear strength, which are the main problems of this soil and retained the soil by an appropriate amount of the cohesion suitable for carrying the loads from the structure.

Combined Effects of Sawdust and Building Rubbles as Aggregate on the Concrete

Dalia Shakir Atwan


Most of building rubbles or wastes contain some damaged materials such as cement, brick, steel, ceramic, plastic and other substances. Among these materials, ceramic and brick when using both of them as a partial replacement by the weight of conventional coarse aggregate in mixture concrete with presence of variety ratios ( 10% to 30%) for sawdust as replacement of fine aggregate, the resulting concrete properties will affected. So, this paper was based on the study some properties of concrete that produced of 50% replacement for those rubbles plus to presence 10%, 20% and 30% sawdust for both of them. The results revealed that present of sawdust with each of type of those rubbles provides database which are potential to be used in the production of lighter and economical new concrete material. Furthermore, the higher ratios of sawdust (more than 10 %) lead to obvious affected on the strength as well as other properties. While, those negative effects will perceptible improved when added 10% sawdust in ceramic aggregate concrete compared to brick aggregate concrete.

Study on the Catalytic Activity of Cerium/Cadmuim Mixed Oxide Catalysts for the Photo catalytic Degradation of Orange G Dye

Atheel Alwash


The Mono and binary-mixed oxide catalysts were prepared by precipitation and co-precipitation method and investigated for the photocatalytic decolorization of orange G dye which was used as a pollutant model in this study. The structure of the synthesized catalysts were characterized by the X-ray diffraction (XRD), bonding by fourier transfer infrared (FTIR), morphology by scanning electron microscope (SEM) and reflection using UV-VIS diffuse reflectance spectra. The XRD results revealed that the mono oxide catalysts confirm well the cubic phase of cadmium and cerium oxide and that their mixed oxide catalyst i.e. 50Ce/25Cd show the same characteristic peaks of pure cerium oxide with slight shift to higher wave lengths for two crystalline peaks at 33.15° and 56.15° respectively. The FTIR spectra of 50Ce/25Cd mixed oxide catalyst improved the combination between both pure cadmium and cerium oxide catalyst. The diffuse reflectance showed a blue shift towards lower wave length and that the energy gap was increased with an increase in cerium content. Different reaction variables such as, effect of metal content, pH values, amount of hydrogen peroxide and effect of catalyst amount were studied to estimate their effect on the decolorization efficiency of orange G dye. The maximum catalytic activity achieved was 91% at a solution pH of 2.1, catalyst dosage of 1.5 g/L, 0.15 mL of H2O2 /100 mL of reaction volume and initial dye concentration of 10 mg/L after 60 min of reaction time.

Characteristics and Properties of Epoxy/Polysulfide Blend Matrix Reinforced by Short Carbon and Glass Fibers

Ibtihal A. Mahmood; Mustafa Ziyara Shamukh


In this research, binary blends have been prepared from epoxy resin (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5 and 10%), and then compression, impact, and hardness tests were evaluated. The experimental results showed that the addition of polysulfide rubber in the epoxy resin decreased the compressive strength, Young's modulus, and hardness, while increased the impact resistance. It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that, it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. Short fibers (Carbon & Glass) with different volume percentage (2.5%, 5%, 7.5%, and 10%), were used to reinforce the best blend matrix obtained separately and randomly, and then the same mechanical tests conducted on these composites. The experimental results showed that the addition of fibers increased the compressive strength, Young's modulus, impact resistance and hardness. It was also observed that the composites materials reinforced with carbon fibers have significantly higher mechanical properties values than the composites materials reinforced with glass fibers.

Numerical and Experimental Investigations of Heat Transfer Enhancement in a Duct Heater with Different Areas of Vortex Generators

Afrah Turki Awad; Kutaeba J. M. Al-Khishali; Dania F. Abbas Aljuboori; Kadhim K.Resan; Ayad M.Takhakh; Hayder Abbas Sallal; Ahmed M. Hameed; Kadhim K. Resan; Khalid M. Eweed; Mujtaba A. Fliayyh; Sadeq H. Bakhy; Mohsin N. Hamzah; Saad Najeeb Shehab; Noor H. Fallooh Al-anbari; Mohammed H. Ali Al-Hayani; Shaymaa M. Mahdi; Saleem Mohammed Obeyed; Israa Shaker Ali; Ali Ehsan; Munqith S. Dawood; Eman Ghadhban Khalil; Halah Hadi Saleh; Zaynab Ibrahim Qasim; Alaa Saadi Abbas; Zahra Ibrahim Qasim; Asmaa Abdul Jabbar Jamel; Hussam K. Risan; Ali Abbar Khleif; Majeed Nemat; Hasan Nemah Khniefer; Audai Hussein Al-Abbas; Ihsan Y. Hussain; Marwah Abdulkareem Jasim; Issam Mohammed Ali; Hind D. R. Albayati; Issam Mohammed Ali; Munther Abdullah Mussa; Mustafa Mahdi Mustafa; Ekhlas Mohammed Fayyedh; Moayed R. Hasan; Ali Falah Mohammed; Ahmed Khalaf Hamoudi; Mohanad J. Mohammed-Ridha; Ali Shihab Ahmed; Nagham Nafea Raoof


Numerical and experimental investigations were carried out on the effect of the vortex generators on the flow field and heat transfer from duct heaters. The flow Reynolds number ranging from 32000


heat transfer
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انتقال الحرارة.

Investigate the Microstructure and the Mechanical Properties of Ni-Ti-Cu Shape Memory Alloys

Dania F. Abbas Aljuboori; Kadhim K.Resan; Ayad M.Takhakh


In this study a Nickel-Titanium-Cupper shape memory alloys was manufactured by powder metallurgy (PM) technique, powder mixture of 50% Ti , 47% Ni and 3% Cu was prepared by mixing for two hours and compacted in a press machine using various compacting pressure (600, 700 and 800) MPa , sample was then sintered for 5 hrs in an electrical tube vacuum furnace using sintering temperature of (850˚C, 900˚C and 950˚C) .phase analysis of samples was conducted by X-ray diffraction test, the effect of different sintering temperature and compacting pressure on the porosity, microhardness ,compression strength and the shape memory effect (SME) was studied, the result showed decrease in the porosity and increasing in the shape recovery ,compression strength and microhardness with increasing compacting pressure and at lower sintering temperature and hence the best results was at 800MPa compacting pressure and 850˚C sintering temperature.

The Effect Of The Hybrid Additions on the Bending and Tensile Behavior for the Hybrid Composite Material Reinforced by Short Fibers and the Zeolite Particles by Multifarious Grain Size

Hayder Abbas Sallal


Consider polymers and polymer matrix composite are the basis of the most prevalent material in all industrial and medical fields because of its properties qualify to occupy an advanced position among other engineering materials because of its good properties.
Therefore, This work focuses on the preparation of base polymer matrix composite materials and study non-saturated polyester as matrix has been strengthened by zeolite particles different grain sizes (25 - 65 - 75) µm and different volume fractions (1,5 - 3 - 4,5 - 6 - 7,5 - 10) % was strengthened by Carbon short fibers and constant volume fraction (8%),the tests tensile and bending according to ASTM specifications, respectively. Through the results it was observed that the maximum tensile strength improved through hybrid reinforcement when reached the maximum value when the grain size (25 µm ) and at volume fraction (7.5%), reaching ( 94 N/mm2 )compared with the rest of sizes and at the same volume fraction reaching (78 N/mm2 for 65 µm , 69 N/mm2 for 75 µm), As for the bending test has been getting maximum Flexural resistance at grain size (25 µm) at volume fraction ( 6%) reached to(111 N/mm2) ,if compared with the rest of sizes at the same volume fraction reaching (100 N/mm2 for 65 µm,79 N/mm2 for 75 µm) while was obtained on the maximum bending modulus at grain size (25 µm) and at volume fraction (10%) reach to (8099 N/mm2) if compared with the rest of sizes at the same volume fraction reaching (7466 N/mm2 for 65 µm, 6666 N/mm2 for 75 µm ). Through the results we note that for the particle size and fiber effect in improving the mechanical behavior of the composite material prepared.

Study the Effect of Reverse Rotation Friction Stir Processing on the Dissimilar Aluminum Alloys

Ahmed M. Hameed; Kadhim K. Resan; Khalid M. Eweed


Friction stir welding (FSW), a solid-state welding process, it’s involve a welding by friction between two metals or alloys, and also using for the joining of dissimilar materials due to the lower processing temperature over conventional fusion welding, it's include only one pass of welding. Friction Stir Processing (FSP) is a recent outgrowth of the Friction Stir Welding (FSW) process and relies on solid-state deformation to modify the structure of the workpiece, it's involve two pass or more of welding and applied either on the base metal(BM) or to join the two alloys/metals. In this paper the new method used, namely reverse rotation friction stir processing (RFSP), this research aims to study the effect of (RFSP) technique on the mechanical properties of welded alloys. (FSW) includes a single pass of the welding line but the second method (RFSP) involves two pass of welding (forth and back) but the 1st pass with a rotation speed in clockwise and the 2nd pass in counter-clockwise. The alloys used of dissimilar AA 2024 and AA6061 aluminum alloys of (3mm) thickness, the parameters used in this research include different rotational speed (1600, 1800, 2000 and 2200) RPM and one feed speed (25) mm/min. In the tensile test the results of reverse rotation friction stir processing (RFSP) was higher than friction stir welding (FSW) for all rotation speeds of welding except (1800 RPM). In the microhardness measurement the values of hardness for all samples at the nugget zone is higher than the basemetal of 6061-T6 and lower than the basemetal of 2024-T3. The efficiency of ultimate tensile strength reaches to about (72 %) for (RFSP) as compare with value of (FSW) and it’s about (44%) at rotation speed (1600 RPM).The only exception of welding was when the rotational speed of (1800 RPM), where the (FSW) is better than (RFSP), efficiency was approximately (77%) for the (FSW) compared with the results of (71%) (RFSP).

Effect of Pin Shape and Rotational Speed on the Mechanical Behaviour and Microstructures of Friction Stir Spot Welding of Aa6061 Aluminum Alloy

Mujtaba A. Fliayyh; Sadeq H. Bakhy; Mohsin N. Hamzah


Friction stir spot welding (FSSW) is a modern solid-state joining process able to weld similar and dissimilar overlap joints in different classes of materials and is widely being considered for automotive industry. In this work, the mechanical behavior ) i.e. tensile shear tests, Microhardness(, and microstructure of friction stir spot welded joints were studied for AA6061-T6 aluminum alloy sheets with thickness of 1.6 mm. Series of FSSW experiments were conducted using vertical CNC milling machine type "C-tek". FSSW is carried out at different pin profiles (cylindrical, taper, and triangular) and tool rotational typically speeds, i.e. 800, 1000, 1200 and 1400 rpm. Based on the welding experiments conducted in this study, the results show that sheets welded by triangular pin tool have highest tensile shear load, of 3.2 kN, followed by welds with cylindrical pin, while welds made using taper pin has the tensile shear load 2.1 kN at optimum speed of 1200 rpm. Also the pin shape and rotational speed had an obvious effect on microstructural parameters i.e. hook height and bond width.

Evaluation Performance of Iterative Algorithms for 3D Image Reconstruction in Cone Beam Geometry

Noor H. Fallooh Al-anbari; Mohammed H. Ali Al-Hayani


Algebraic reconstruction technique (ART) is iterative reconstruction algorithm using for reconstructing the two dimension (2D) and three dimension (3D) images. In this research different algorithms of ART were used to reconstruction : (simple ART, Simultaneous ART, and Multiplicative ART) for reconstruction 3D image using multi slice scanner in cone beam geometry. To perform the time reconstruction of ART algorithms, use the Maximum-Likelihood Expectation Maximization (ML-EM) algorithm to fast ART algorithm. Multi slice Computed Tomography CT scanner newly discovered and used widely in the medical field for diagnosis and radiographic to its benefit from the speed of scanner and quality of image reconstruction comparing with single slice scanner. In simulation result the Multiplicative ART (MART) algorithm with suitable relaxation parameter

Experimental Study of Free-Convection from Rectangular Fins Array on a Heated Horizontal Plate with Notch Effects

Saad Najeeb Shehab


In this work , experimental investigation has been done for free-convection heat transfer from rectangular fins array on a heated horizontal base plate to surrounding air in the steady-state flow condition with rectangular notch portion effects. Five cases of fins arrays have been employed . One case without notch and other cases with rectangular notches for different percentages of aspect ratio area removal from fin . The horizontal base plate has been heated with various electrical supplied power values. Different number of fins and spacing have been used . The effect of notches from fins on average convection heat transfer coefficient and average Nusselt number at constant aspect ratio of fin height to fin length and varying heat inputs to the heating element have been discussed . The experimental results show that the performance of notched fins array in term of average convection heat transfer coefficient is 28% to 45% higher than unnotched fins array. The present experimental results have been compared with previously works . The results show a good a greement.

Investigation and Enhancement Using Different Types of Pipelines for the Servo Hydraulic System with PID Controller Tuned Using Fuzzy Logic

Shaymaa M. Mahdi


This paper aims to investigate the effect of using different types of pipelines with the servo hydraulic system enhanced with PID controllers tuned by fuzzy logic. The mathematical models of several types of pipelines with different specifications (i.e. area variations in the pipe, disturbance source, etc.) are developed. The effect of the modified pipelines on the position control system at spool displacement is tested,since the servo hydraulic systems are difficult to control due to nonlinearity and complexity of their mathematical models. A PID controller tuned using fuzzy logic technique is used to improve the servo hydraulic system response.The results show that the mathematical models of the pipelines have a significant effect on the performance of the position control system at spool displacement according to the used pipeline type.Furthermore, a more desirable time response specifications and less steady state error are achieved after using the proposed controller.

Treatment of Reused Oil by Thermal Conversion Process

Saleem Mohammed Obeyed; Israa Shaker Ali; Ali Ehsan


This work deals with treatment ofused lubricant oils whichare accumulate from automotive engine, bythermal conversion process. The used lubricant oil for two samples is fractionated by the atmospheric distillation device into fractions, (waste oil liquids and residue). Which are carried out at atmospheric pressure and temperature up to 350 ºC.
The conversion which was obtained from these fractions was (92 and95) % respectively for these two samples.
The fractionated waste oil liquids products fromatmospheric distillationdeviceare fractionated alsoto light fractions (gasoline, kerosene, gas oil) and residue for these two samples at atmospheric pressure according to their boiling point.These fractions for these two samples are also distillated inatmospheric distillation device, in order to calculatesome important physical and chemical properties (Mean average boiling point, specific gravity, flash point, aniline point, smoke point, molecular weight) of these fractions, to comparison with standardphysical and chemical properties, alsostudying the possibilities of industrial uses for these fractions.
The yield of gas oil for the first samplein waste lubricant oilisabout 50%, more than gasoline 15% and kerosene 30%from 100 ml of treatment waste lubricant oil, and more identical curve from gasoline and kerosene curve.
Also for the second sample, the yield of gas oil is the largest quantity 43%fromtheyield of gasoline 15% and yield of kerosene 35% from 200 ml of treatment waste lubricant oil, and more identical curve with kerosene from gasoline curve.

Detection of Tumor Mass Based on Laser Scanning Imaging

Munqith S. Dawood; Eman Ghadhban Khalil; Halah Hadi Saleh


Optical methods are widely used for medical diagnostic and therapeutic purposes. The use of laser source as non-ionized radiation in the imaging is considered safe, and has advantages more than the other radiological methods The laser application in imaging is based upon the detection and measuring the laser light parameters after passing through the turbid media of the tissue layers and the tumor mass to differentiate them precisely according to their different optical properties.
In this experimental study, the tumor masses were implanted in the legs of ex-vivo mice. Then each leg was non-invasively scanned by NIR 785nm diode laser. The penetrated laser light power through the leg was measured. The results were tabulated and treated by using the Matlab program version R2013a ( to create 2D image for the scanned tissue. The resulted images were clear. They showed precisely the imbedded tumor, its dimensions, and its location inside the tissue.

Effect of Filler Content on Properties of Asphaltic Mixtures for Marshall and Superpave Gyratory Compactor

Zaynab Ibrahim Qasim; Alaa Saadi Abbas; Zahra Ibrahim Qasim


In Iraq some pavements of the newly constructed highway appear precocious distresses with unfavorable implications especially on the safety and the frugality. Cracking and permanent deformation are main types of these failures. The filler is doubtful to be a master contributor to these failures where its content has a significance effect on the mixture stiffness, and thereby affect the HMA pavement performance. The main objective of this research is to appreciate the influence of different contents of filler on the volumetric properties of asphaltic mixtures thus performance of asphalt mixtures through Comparative Evaluation between conventional Marshall Method and Super pave system. The implementation of a detailed experimental work is carried out to achieve the study objectives through the preparation of asphalt concrete samples using aggregate from Al-Nebaie quarry, (40-50) asphalt cement from Dourah refinery and limestone dust filler with four different contents of (0%, 4%, 8%, and 12%) by weight of the total aggregate. The volumetric properties for each mix design method are evaluated using Marshall Test and the Super pave Gyratory Compacter. The influence of filler contents on the rendering of these mixtures was evaluated.

Effect of Two Sheet Piles In Double Soil Layers on Seepage Properties Under Hydraulic Structure Using SEEP/W Program

Asmaa Abdul Jabbar Jamel


This paper is intended to study the effect of using upstream and downstream sheet pile in double soil layer on the seepage, uplift pressure exit gradient at toe of hydraulic structure using computer program SEEP/W software.
Depended on the software program tests were carried out with three different value of each following parameter: upstream sheet pile depth, downstream sheet pile depth, permeability for first and second soil layer, depth of first and second soil layer, with using constant upstream head and distance between the two sheet pile. For each test the quantity of seepage, exit gradient and uplift pressure at toe of hydraulics structure were determined. Based on the results of these runs an empirical equations developed to determine the quantity of seepage, uplift pressure and exit gradient at toe of hydraulic structure by using SPSS software. Also, Verify the SEEP/W results and the suggested equations with artificial neural network (ANN). The verification show difference less than 5% , 2% and 6% for exit gradient, discharge and uplift pressure respectively at toe of hydraulic structure.

Cracking Control due to Early Thermal Movement of Watertight Continuous RC Members

Hussam K. Risan


Action of applied external loads, early thermal by hydration of cement in reinforced concrete (RC) structures, creep and shrinkage and seasonal effects due to environmental conditions are the main causes of inducing cracks in RC members. Most Design Codes of RC structures have underestimated the distribution steel requirements based on stating nominal or minimum requirements for early thermal and moisture movement especially in watertight continuous constructions. Three dimensional finite element analysis for a verification problem was carried out on a continuous reinforced concrete members with different bar diameter subjected to different applied temperatures values which represent the early-age and seasonal effects. The results of this analysis were compared with the available BS Code equations for crack control for early thermal movements. The comparison between the Code equation and finite element analysis was met in a good agreement. The resulted data was used to study parametrically the crack characteristics in terms of crack width and spacing of RC members in term of the effects of three different construction exposures (Class A, B and C), three values of temperatures with three different bar size diameter (10mm, 12, 16) for each one. The present work was indicated as the bar diameter increases, the required steel ratio increases proportionality to match the assumed crack width. So, to get the minimum steel ratio this is the target. It must use smallest bar diameter. But unfortunately this is limited by minimum practical bar spacing. The overall of present study was indicated that the continuous construction required high steel area especially for class A exposure.

A Comparitive Study of CNC Milling Cutting Path Strategies

Ali Abbar Khleif; Majeed Nemat; Hasan Nemah Khniefer


This paper investigates the effect of cutter path used in the milling process on the produced surface roughness using two different tools. The cutting paths which are named as; one directional, zigzag , Morph, overlap spiral and spiral are considered as cutter path strategies. The cutter path strategies greatly influenc the surface finish of the work pieces. The objective of this study is to investigate the best cutting characteristics and effects of cutting path for aluminuim using end mill and ball mill tools. MASTER CAM software has been used in design and producing NC CODE. The results indicate that the raw tool path strategy and flat end mill tool gives minimum roughness value with (0.15µm), while the spiral tool path strategy and ball end mill tool gives minimum roughness value with (0.76µm).

Computational Fluid Dynamics (CFD) Modeling Study of Thermal Performance for Multipurpose Solar Heating System

Audai Hussein Al-Abbas


The 3-D numerical simulations of the thermal collectors in solar heating systems were conducted to simulate the conventional solar heating system, multipurpose solar water heater (MPSWH), and multipurpose solar air heater (MPSAH). The commercial computational fluid dynamics (CFD), AVL Fire ver. 2009.2 was used to solve and investigate the temperature distributions in the absorber plate and riser tube of both solar water and air heater during summer and winter seasons. The RNG k - turbulence model was employed for this CFD study. The present paper was to provide a good understanding of thermal performance for the solar collector at different operating conditions. The experimental setup and physical data of Venkatesh, R. and Christraj, W. [15] were employed as geometric parameters and initial boundary conditions to model and to validate the predicted numerical values. Comparing to the values of temperatures for the conventional SWH and SAH, the predicted results of the MPSWH and the MPSAH showed a good improvement on the thermal performance. These enhancements on the temperature may have been due to the new design adopted in the multipurpose solar heating systems by using riser tubes and headers to the original design of the thermal systems. Additionally, the thermal performance of solar collectors increases with increasing the mass flow rates and thermal conductivity of absorber plate. For validation aspect, the predicted results of all cases examined showed a good agreement against the measured results in terms of temperature distribution levels and thermal efficiencies.

Thermal Performance Enhancement of Phase Change Materials (PCMs) by Using Metal Foams

Ihsan Y. Hussain; Marwah Abdulkareem Jasim


An investigation of thermal conductivity enhancement, melting and solidification processes of Phase Change Materials (PCMs) by using metal foams has been carried out. Two models have been used in the experiments, model I for measuring the effective thermal conductivity of metal foam embedded in paraffin wax, and model II used as a small scale thermal energy storage device with and without metal foam for investigating melting and solidification processes of the PCM under different cooling conditions (natural and forced convection). The theoretical investigation involves analytical solution of two models, the semi-infinite medium for calculating the thermal conductivity, and the thermal energy storage system TESS has been analyzed including several assumptions for determining the convective heat transfer coefficient and the factors that controlling forced convection and solidification of the PCM. The experimental results show that the thermal conductivity of wax with 10 PPI metal foam increased by (37-39) times that of pure wax. Effects of pore density (10 and 40 PPI), metal foam, and mass flow rate on solidification process have been studied and the effects of pore density and metal foam on the melting process have also been investigated. The present experimental results have been compared with the available previous studies and gave a good agreement.

Hydrogen Production by Hybrid photovoltaic Thermal System

Karima E. Amori; Sameer M. Salman; Zahraa Hashim Kareem


Hydrogen fuel is a good alternative to fossil fuels. It can be produced using a clean energy without contaminated emissions. This work is concerned with experimental study on hydrogen production via solar energy. Hybrid photovoltaic thermal system (PV/T) is used to convert solar radiation to electrical and thermal energy. The electrical energy is used to analyze water into hydrogen and oxygen by using alkaline water electrolyzer with stainless steel electrodes. The absorbed thermal energy is used to heat circulating water inside the copper serpentine pipe fixed on the back surface of the PV panel. A perforated pipe connected on the upper edge of PV panel is used to spray a thin layer of water on the PV panel surface for auxiliary cooling and improve the generated electrical power. The hydrogen production system is tested at different temperature of electrolysis water (40, 45, 50, 55, 60)˚C. The experimental results show that the PV module electrical efficiency is improved by (14.31)%. while the power generated was enhanced by (3.94 to 15.40)%. The maximum hydrogen production rate is 153.3 ml/min, the efficiency of the system is 20.88% and the total amount of hydrogen produced in one day is 220.752 liter.

Influence of Covering Materials and Shading on the Greenhouse Cooling in Iraq

Issam Mohammed Ali; Hind D. R. Albayati


Cooling greenhouses is essential to provide a suitable environment for plant growth in arid regions. However, using conventional cooling methods are facing many challenges. Filtering out near infra-red radiation (NIR) at the greenhouse cover can significantly reduce the heating load and can solve the overheating problem of the greenhouse air temperature. Four cases of shadings were examined for their ability to improve the indoor condition of a greenhouse cooled by indirect direct evaporative cooler: (shade 1) a single layer of polyethylene film, (shade 2) a double layer of polyethylene film, (shade 3) a double layer of polyethylene film with a green mesh layer (shade 4) a double layer of polyethylene film with a Utrecht Corrugated Cardboard with 3cm holes distributed for incident sun light. An experimental study is conducted to determine the performance parameters of indirect direct evaporative cooling of greenhouse in Baghdad (33.3 oN, 44.4oE) for the four types of shadings. It was found that the percentage reduction in light intensities for shade 1, shade 2 and shade 3 are 15%, 25% and 40% respectively. It percentage reduction solar intensity due to shades is increases at the beginning and ending of sunny period, while it was minimum at noon. The percentage reduction in temperature due to indirect direct evaporative cooling for the shade1, shade 2 and shade 3 and shade 4 are 32.4, 36.3, 42.4, and 47 respectively. The percentage increasing in relative humidity due to indirect direct evaporative cooling for the shade1, shade 2 and shade 3 and shade 4 are 562.5, 729, 871, and 788 respectively. The percentage increasing in temperature due heating load of greenhouse for the shade1, shade 2 and shade 3 and shade 4 are 41.4, 33.2, 20.5, and 11 respectively. The percentage decrease in relative humidity due heating load of greenhouse for the shade1, shade 2 and shade 3 and shade 4 are 43.4, 31, 11.8, and 7 respectively.

Experimental Investigation of Forced Convection Heat Transfer in Open Cell Copper Fins

Issam Mohammed Ali; Munther Abdullah Mussa; Mustafa Mahdi Mustafa


Recently, major part of convection heat transfer researches focus on increasing fins efficiency by increasing thermal performance for the same fin volume. Metal foam is a promising way to achieve this aim. Performance analysis has been carried out to investigate the heat transfer characteristics of copper fin foam samples. The samples have been compared with the solid metal fin heat transfer. A forced convection heat transfer had been applied to a four specimens. An electrical heater heats up the fins, which are subjected to a stream of the ambient air driven by a blower fan as heat dissipated. The heat flux had been fixed along the tests with three different air velocity used; the forced heat convection had been simulated. The pores density of copper fin foam is varied in the range of 10, 20 & 40 pores per inches (PPI). Thermal performance of copper fin foam has been evaluated in terms of average Nusselt number and thermal resistance of heat sinks. The increasing in the heat transfer rate and average Nusselt number when used metal foam has been found in the range of 36-133 % compare to solid copper. Furthermore, it has been proven that this increment reaches the maximum value for a given PPI even when raise the air velocity.

The Combined Effect of Rib with Single Large Eddy Break Up Devices on Flow and Heat Transfer Characteristic of Turbulent Flow in Rectangular Duct

Ekhlas Mohammed Fayyedh; Moayed R. Hasan; Ali Falah Mohammed


An experimental investigation has been performed to study the effect of combined artificially roughened (ribs) with and without single Large Eddy Break-Up Devices, on flow and heat transfer characteristic of fully developed turbulent flow in rectangular duct. The aspect ratio of rectangular duct is 10, hydraulic diameter 72.72 mm, relative roughness pitch (P/e) 10 and relative roughness height (e/Dh) 0.05. The rib was in the form of circular shape with diameter of (4mm) which was mounted on heated wall of duct at spanwise direction. The experiments have been conducted by varying airflow rate in terms of Reynolds number ranging from 3.2x104 to 6.2x104 and constant heat flux of 600W/m2. The heat transfer and friction factor of the flow for rib and combined method were compared with those of a smooth duct under similar experimental conditions. It has been found that the combined method (rib with single Large Eddy Break-Up Devices) has significant effect on the friction factor and heat transfer with decreasing in friction factor with percent(1.2) and increasing Nusselt number with (4.1). Correlations for Nusselt number and friction factor in terms of (Reynolds number and Large Eddy Break-Up Devices) parameters are found which reasonably correlate the experimental data.

Optimum Setting of PID Controller using Particle Swarm Optimization for a Position Control System

Ahmed Khalaf Hamoudi


The goal of this paper is to present a study of tuning the Proportional–Integral-Derivative (PID) controller for control the position of a DC motor by using the Particle Swarm Optimization (PSO) technique as well as the Ziegler & Nichols (ZN) technique. The conventional Ziegler & Nichols (ZN) method for tuning the PID controller gives a big overshoot and large settling time, so for this reason a modern control approach such as particle swarm optimization (PSO) is used to overcome this disadvantage. In this work, a third order system is considered to be the model of a DC motor. Four types of performance indices are used when using the particle swarm optimization technique. These indices are ISE, IAE, ITAE and ITSE. Also study the effect of each one of these performance indices by obtaining the percentage overshoot and settling time when a unit step input is applied to a DC motor. A comparison is made between the two methods for tuning the parameters of PID controller for control the position of a DC motor is considered. The first one is tuning the controller by using the Particle Swarm Optimization technique where the second is tuning by using the Ziegler & Nichols method. The proposed PID parameters adjustment by the Particle Swarm Optimization technique showed better results than the Ziegler & Nichols’ method. The obtained simulation results showed good validity of the proposed method. MATLAB programming and Simulink were adopted in this work.

Investigation of The Thermodynamic, Kinetic and Equilibrium Parameters of Batch Biosorption of Pb(II), Cu(II), And Ni(II) From Aqueous Phase using Low Cost Biosorbent

Mohanad J. Mohammed-Ridha; Ali Shihab Ahmed; Nagham Nafea Raoof


In this study, low cost biosorbent ̶ inactive biomass (IB) granules (dp=0.433mm) taken from drying beds of Al-Rustomia Wastewater Treatment Plant, Baghdad-Iraq were used for investigating the optimum conditions of Pb(II), Cu(II), and Ni(II) biosorption from aqueous solutions. Various physico-chemical parameters such as initial metal ion concentration (50 to 200 mg/l), equilibrium time (0-180 min), pH (2-9), agitation speed (50-200 rpm), particles size (0.433 mm), and adsorbent dosage (0.05-1 g/100 ml) were studied. Six mathematical models describing the biosorption equilibrium and isotherm constants were tested to find the maximum uptake capacities: Langmuir, Freundlich, Redlich–Peterson, Sips, Khan, and Toth models. The best fit to the Pb(II) and Ni(II) biosorption results was obtained by Langmuir model with maximum uptake capacities of 52.76 and 36.97 mg/g for these two ions respectively. While for Cu(II) the corresponding value was 38.07 mg/g obtained with Khan model. The kinetic study demonstrated that the optimum agitation speed was 400 rpm, at which the best removal efficiency and/or minimum surface mass transfer resistance (MSMTR) was achieved. A pseudo-second-order rate kinetic model gave the best fit to the experimental data (R 2 = 0.99), resulting in mass transfer coefficient values of 42.84×〖10〗^(-5), 1.57×〖10〗^(-5) , and 2.85×〖10〗^(-5) m/s for Pb(II), Cu(II), and Ni(II) respectively. The thermodynamic study showed that the biosorption process was spontaneous and exothermic in nature.

The Durability of materials and its effect on Architectural Monumentality

Maryam Safaa Hussein


From centuries , the human struggle against the forces that effected on its shelter and try to conserve it , to obtain stable structure that protect him from the external forces and meets him desire to conserve this structure as cultural inheritance from the past .
The development in architect possibilities push him to search about building not just as a distinctive design among the public pattern of building , and meet it desire of eternity and crossing the time barrier towards the durability .
As the visual part that we can realized physically need for materials having the advantages of the durability, the research supposed "The relation of the monumentality of architecture in its physical part with the main three substrates of the durability of building materials that presented in : climate , time and human " the research focus on this substrates and its effect to arrive to monument buildings .
The research try to define the vocabularies of durability and monumentality and abstracting three substrates that forming its assumption and the research indicates mainly to the importance of the architect knowledge of the durability of materials after choosing and using in building and know every substrate from the main three supposed substrates that effected on it during the life service that supposed to be work in it, and define nanotechnology in building materials and its effect on durability.
Finally the research take a research samples that tested in the research assumption for the three substrates that effected on the durability of material and its mirror on the monumentality arriving to the final results and recommendation.

The Objective Attitude in Architectural Academic Local Research

Suha Hassan Al-Dahwi; Nawfal Joseph Rzqoo; Khalid Abd Al-Wahab


Theory in general have been seen from two point of view, in one side, we find that Theory have drawn from the philosophical roots which have its consideration that consistence with people persuasion and researcher's agreement, and from the other side theory is responsible about giving an interpretations and explanations about something in nature or in the cultural social world in a way that it's statements may permit to be tested and analyzed by the action of the research. And because of the interdisciplinary wide range of subjects that may the theory of Architecture builds from , and in order to understand the scientific nature of the Academic Architectural local theorization, thereby we have to explain what do we mean by ( Theory) as a general Concept ,and in Architecture specifically ,in addition we have to explain the wide range of subjects that may the theory of Architecture builds from ,which makes its scientific testing method difficult because of the big parts of its subjects that belong to the human science where concepts like (Subjectivity),(Values),(Ideology) play a Big role in. and so the needs to provide a descriptive framework for the characteristics of the scientific theory in general was risen ,which may be very helpful to distinguish the instructions that achieve the scientific theory in its real meaning within the Academic Architectural local theorizing specifically. From here the research problem where determined by: " we do not have a framework that capable of describe the Academic Architectural local theorization whether it is achieve the criteria of formulating the scientific theorization or not. So the research seeks to:" state the nature of the scientific instructions to formulate the Architectural Theory , and the problem of it in general, and the way that we can classify the theory by, and disclose the theoretical framework which we can use to test the Architectural theorizing (postgraduate students dissertation - M.s.c. & Ph.D.- ) .the research determined the forward mechanism to achieve it's Goal which consist of: defining the meaning of theory in general ,and the position of the Architectural theory in the Theorizing World to reach the characteristics of the general descriptive framework of theory to depend on in testing the Academic Architectural local theorization whether it is achieve its criteria or not. The research conclude that descriptive framework, and explain the interdisciplinary wide range of subjects that may the theory of Architecture builds from, and the way that the theory of Architecture were classified between (Normative &Positivist Theory) and the characteristics of each trend. The Research Findings were summarized that the Normative Theory ( the Argumentational theories especially) which work in (what Ought to be ) Level ,suffered from the difficulty of connecting them with the living world or with the fact the they cannot be tested, and the research also find that these theories by its Hypotheses do not have it's logical connections ( we mean by logic :the relation between Premises & Conclusions),it's Premises institutes on Metaphysical world beyond the real living world ) which work in (what Ought to be ) Level and the differences of their philosophical Structures due to the difference of their basic philosophical assumptions ( Existential , Epistemological ,Methodological ,and approach to the human nature) that adopted by the researchers. The research recommended the necessity of distinguish between the theorizing criteria for subject research that belong to the two level of hypotheses (what ought to be -level, & and the level of -what it is exist already) where it is not valid to conclude one from the other because they have different testing criteria.