Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 23, Issue 2

Volume 23, Issue 2, Winter and Spring 2015, Page 1-197

The Effect of Mold Rotational Speed on Mechanical Properties of Functionally Graded Polymeric Matrix Composites

Ahmed Akram Abdullah; Awad Hallosh Khidhir

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 1-12
DOI: 10.33899/rengj.2015.101070

In this research, a functionally graded polymeric matrix composites (FGPMCs) were produced using centrifugal casting method. These composites were fabricated from unsaturated polyester resin as a matrix and reinforced with silicon carbide particles (SiCp) of (106µm) and (6%)bulk volume fraction, using different mold rotational speeds(400,500,600 R.P.M) at room temperature (22Cº).Additional (3) samples of pure polyester were manufactured at the same conditions for comparison purpose .The aim of the present research was to study the effect of mold rotational speed on local values of volume fraction,hardness and Young modulus at specific points along the graded samples. Hardness was measured at these points then graded samples were cut to eight portions .Densityand volume fraction were evaluated,then standard homogenoussamples of constant but different volume fraction were manufactured. Results shows that local values of volume fraction, hardness and Young Modulus decreased in nearby positions of the center of rotation and increased in positions far away from the center of rotation with increasing mold rotational speed.

Practical Analysis for Studying the Effect of Both Depth and Soil types on the Stresses Generated on the draw-bar During Plowing Process

Shamil M. Hassan

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 13-19
DOI: 10.33899/rengj.2015.101071

A study was conducted for the purpose of determining the stresses generated on the draw-bar as a result of different types of soil and depth produced during plowing process in two different soils.
Laboratory analysis was conducted for studying the soil analysis in the department of Civil Engineering University of Mosul.
Analysis revealed that there were two different types of soil (clay and mixed). At the same time mechanical properties and basic measurements of draw-bar was carried out. At the same time stress analysis of draw-bar was done using finiteelements program (Ansys releases 14.0 types), to determine the properties during application in different stress analysis parameters where used (x, y, z) and Von
Mises in addition to principal stresses and percentage deviation of the direction of the three axes (x, y, z).
During practical phrase, installation of strain gauges on draw-bar was done , for two types of soil at different depth level factors using three level (40, 45, 50) cm.
The present results revealed that there was a difference in the stress values generated in relation to depth and types of soil.

Laboratory Study of Flow Characteristics Over Piano Key Weir

Bushra M. Ali; Hana A. Hayawi

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 20-30
DOI: 10.33899/rengj.2015.101072

The main objective of this investigation is to obtain performance efficiency and the coefficient of discharge for Piano Key weir with downstream overhang. One hundred thirty five experimentswere conducted on models of Piano key weirs. Three slope of the inlet key (Si = 0.7, 0.6, 0.46), three different ratios for the inlet key width to the out let key width (Wi/Wo= 1, 1.61, 1.81) and three heights (p = 30, 25, 20) cm for each weir were used. The results showed that the slope of the inlet key (0.7) gavea lowervaluesof performance efficiency and a highest values of coefficient of discharge than (0.6, 0.46) keyswhile ratios of inlet key width to the out let key width (Wi/Wo = 1.81) gave a highest values of coefficient ofdischarge. An empirical relationship was found for estimate the coefficient of discharge and performance efficiency in relation to thenon dimensionless variable

Evaluating performance of Hydrus-1D model in simulating evaporation from soil surface for different wetting intervals

Muzahim M. Abid; Eftikhar A. Alani; Entesar M. Ghazal

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 31-43
DOI: 10.33899/rengj.2015.101073

In this study, Hydrus-1D model was used to simulate the evaporation from the soil surface for different wetting intervals for northern region(sandy loam and clay loam) using input for climatic data , and data of class Apan evaporation.The results showed that data of pan evaporation class A can be relied on in simulating and calculation of evaporation from the soil surface, where the standards of statistics (IOA, R2) calculated on the basis of evaporation pan class A data are better for the wetting intervals (2,4, 8, 16 ) days compared with the values of those standards based on full climate data and both types of soil. The study also showed that the wetting intervals and their impact on evaporation from the soil surface and evaporation stages reasonably agree with the results of field experiments that have been made in this area.

Pipelined Parallel Implementation of CryptosystemsBased on Advanced Encryption Standard

Israa G. Mohammed; Shifaa A. Dawood

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 44-55
DOI: 10.33899/rengj.2015.101074

A hardware architecture implementation of Advanced Encryption Standard (AES) is globally adopted to encrypt data for variant communications systems, taking into account that AES is reliable, secured and immunized against attacks. A single crypto system is suggested to encrypt and/or decrypt different types of data .These types of data are assumed to be as a text data .The image is considered as a case study for the type of data that is to be encrypted in real time. Then the proposed architectures are used to encrypt the video within the time ≤ 33 m sec . Two architectures are proposed . The first one is a hybrid of both stream and block ciphering. This architecture is used to increase the encryption security by reducing the correlation among image pixels. The resulting encryption time for an image of (32x64)pixels is equal to 16.76 µ sec. The second architecture is proposed for CTR mode of AES algorithm. The same time achieved in the first architecture is also achieved in this implementation. However ,the half of the hardware resources in comparison with the first architecture is achieved in implementing the second, but if it is used for either encryption or decryption , not for both simultaneity. The real time implementation is achieved due to using parallel computation that is based on pipelining technique. The architecture are synthesized on Spartan-6 LX(XC6SLX16) using ISE 14.2 .

Effect of Some Operating Parameters on the Performance of Ballasted Flocculation Technique for Water Treatment

Ahmed Yasoob; Suhair Kharrufa; Suaad Abbawi

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 56-72
DOI: 10.33899/rengj.2015.101075

The study aimed to apply the concept of Ballasted Flocculation (BF) at modified jar test for different turbidities for Tigris rivers raw water in order to find out the optimum values for each of :the additives chemicals, the ballasted agent doses and the operating conditions which are each of the detention time and velocity gradient
A study of366 samples for six levels of initial synthetic turbidity of the Tigris River showed that it is possible to ad optBF technique successfully, and it reduces the time of the treatment phase and increase the stability of the quality of water treatment, but doesnotreducetheconcentrationsofthe chemicals which are used. The study showsthattheuseofalumconcentrationof30-40mg/Lwithpolymerconcentrationof0.2-0.4mg/L and BAconcentrationof0.5-2.5g/L forthe range of diametersbetween75-212 μmachievea residualturbidity ~1 NTU for supernatant water

Considering the Spatial Adjacency and Syntactic Properties Affecting the Functional Performance of the Socially Sustainable Schools in Iraq

Tara A. Abbo Al-Yase; Dr. Ali H. Al-Jameel

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 73-90
DOI: 10.33899/rengj.2015.101076

The socially sustainable school is an emergent conceptappearedwithin the context of many significant changes in the world schools’ designs.Also, the functional performance is considered as a principal constituent for the socially sustainable schools. On the other hand, Iraqi schools are suffering, generally, from being of low functional performance; a problem resulted, as this research believes, from certain forms of considering the spatial adjacency and syntactic properties which are the mostinfluencing factors for the schools’ functional performance. This research tackles the problem that there are no clear conceptions about the extent and how those properties are consideredin the design practices of the Iraqi elementary schools. It adopts the objective of defining these conceptions using a method which includes defining the related influencing spatial adjacency and syntactic properties firstly, then measuringto what extent and how the defined properties are considered in the designs of Iraqi schools in comparision withthe world design practice framed by the general theory of the socially sustainable schools. After discussing the results, the final conclusions which define theweaknesses and defecitsof the local schools’ design practices regarding the consideration of the properties of interest are presented

Estimation of Model Parameters, for Torsional Vibration Analysis ofa Turbo-Generator Unit with Reference to Mosul Gas-Turbine Station

Dr.F. Q. Yahya; Dr.Z. Y. Mohammad; Dr.S. M. Ali

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 91-116
DOI: 10.33899/rengj.2015.101077

In the design stage or analysis of any dynamical system a detailed or comprehensive model is essentially required. In this work, different parts and components that are contained in the model of a turbo-generator unit (T.G) for torsional vibration analysis are considered and the governing equations of which are presented and developed to estimate their respective parameters. These parts and components are mainly compressor seventeen stages and blades, turbine two stages and blades, reduction gear system with the safety shaft, the rotor of the generator, the exciter and the fluid film bearings on which the whole system is supported. The data upon which the system model is built are referred to Mosul gas turbine station units.The estimated parameters are those related to rotational inertia, damping and stiffness effects of the different components in the system.A detailed model of the system should be useful for the purpose of torsional vibrational during rotation with normal steady loading or under severe loading conditions utilizing a block diagram via Matlab. The system eigen values natural frequencies (critical speeds) and mode shapes are determined.

Numerical study of natural convection heat transfer from a heater placed in an enclosure with adjacent inclined sidewall

Ramiz I. Al-Abushi

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 117-132
DOI: 10.33899/rengj.2015.101078

In this investigation , natural convection heat transfer from a heater placed on the bottom of a square enclosure with adjacent inclined wall was carried out . The inclined wall has a constant lowtemperature , while the heater element has a constant high temperature ,and the remaining walls are insulated . The working fluid used is air with Prandtl number (Pr=0.72) . The governing equations of the problem are solved numerically by using finite differencemethod . The numerical solution is presented for various Rayligh numbers,Ra(103-105) , with different dimensionless parameters as length of heater (Yh¬) (0.1,0.3,0.5), different locations of the heater (Xh) (0.25,0.5) and inclination angle of inclined cold wall  (10o, 20o, 30o). The results are presented by isotherms and streamlines to show the behavior of the flow and temperature distribution .While the numerical results of heat transfer are presented by average Nusselt number and local Nusselt numbers at right , left and top sides of heater.The results show the effect of dimensionless parameters on heat transfer and Nusselt number.It is observed that the Nusselt number increased by increasing Raylig number , heater length , inclination angle of cold wall and where the heater is near the cold wall (Xh=0.5).

Optimum design of a heat pipe

Mohammad S. Aldabbagh

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 133-146
DOI: 10.33899/rengj.2015.101079

This research deals with the optimum design of the heat pipe components using Matlab program, version 7, at the determined operating conditions. The heat pipe is used to transfer maximum available thermal energy to heat the feed water entering steam boiler .
The affecting parameters on heat pipe performance were detailed as well as the transport limitations and the thermal resistances of the heat pipe parts. Satisfactory results were obtained for the heat pipe dimensions, components and design influentials. Also, the parameters affecting the heat transfer rate and the working fluid mass-flow rate were discussed. From the important results, the heat pipe heat transfer capability is directly proportional with each of the heat pipe bore, the wick c/s area and the heat pipe effective length, and inversely with each of the capillary radius and the working fluid viscosity.

Study of the Ultrasonic Behavior in (α + β`) Brass Alloy

Mohammed Shaalan Abed Fathi

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 147-152
DOI: 10.33899/rengj.2015.101080

Copper is one of the few metals with significant commercial uses. Although frequently used as a pure metal or with small amounts of metal additives, copper can form 82 binary alloys. Two of the most common are brass (copper-zinc) and bronze (copper-tin). This research work tries to study the ultrasonic behaviour in one of the important brass alloys represented by (α + β`) brass alloy.
Specimens of (α + β`) brass were machined to cylindrical shape with different thicknesses in order to study the effect of the sound scanning distance on the acoustic attenuation of the ultrasonic waves.
The results indicate that it is plausible to inspect (α + β`) brass using both 2MHz and 4MHz frequencies, and that the acoustic attenuation of ultrasonic waves has increased when 4MHz probe was used. In addition, the results illustrate that the acoustic attenuation increases as the sound path distance increases.

Neuro-Fuzzy Based ECG Signal Classification with A Gaussian Derivative Filter

H. N. Yahya; S. N. M. Al-Faydi; Dr. J. M. Abdul-Jabbar

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 153-166
DOI: 10.33899/rengj.2015.101081

In this paper, a neuro-fuzzy classification method is used for identifications of ECG signals. A feature extraction method with a QRS like filter (first order Gaussian derivative filter) is used. Five standard parameters (energy, mean value, standard deviation, maximum and minimum) are extracted from these diseasefeatures and then used as inputs for the neuro-fuzzy classification system. The ECG signals are importedfrom the standard MIT-BIH database. Five types of ECG signalsare used for classification; they are normal sinus rhythm (NSR), left bundle branch block (LBBB), right bundle branch block (RBBB), premature ventricular contraction (PVC) and pacemaker (PM). The proposed system combines the neural network adaptive capabilities and fuzzy inference system with the suitable filter design to give a promising classification accuracy of 99%.

RAM-Based Neural Network Parallel Implementation on a Reconfigurable Platform and Its Application for Handwritten Digits Recognition

Shefa A. Dawwd; Ali Al-Saegh

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 167-178
DOI: 10.33899/rengj.2015.101082

Artificial neural networks (ANNs) are widely used in different areas of nowadays applications. Many challenges are imposed on the practical implementation of ANNs. Some of them are: the number of samples required to train the network; the number of adders, multipliers, nonlinear transfer functions, storage elements; and the speed of calculations in either training phase or recall phase. In this paper, the RAM-based neural network is investigated. No weights, adders, multipliers, transfer functions are required to implement it neither in hardware nor in software, but at a cost of large RAM utilization. In addition, a small number of samples are required for training. However, in hardware implementation, a large size of memory is required to train it.The network is implemented on the FPGA platform. The Stratix IV GX FPGA development board, which is provided on large on board RAM, is used. A considerable speedup of 237is achievedin either training or recalling phases. A comparable error rate of 7.6 is achieved when MNIST (Mixed National Institute of Standards and Technology) database are used to train the network on handwritten digit recognition.

Mechanical Properties of Wood Shavings-Cement Lightweight Composites

Emdad K. ZEYNAL; Dr. Moayad M.Kasim

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 179-186
DOI: 10.33899/rengj.2015.101083

The use of wood shavings, as a recycled waste product from the wood furniture industries is an interesting technique to produce lightweight cement composites. This study aims at examining the mechanical properties of wood shavings-cement lightweight composites. First, the wood shavings were pre-treated with water or superplasticizer or Cement Based Bitumen Emulsion (CBBE). Then, the compressive strength and tensile strength of the wood-cement matrix were experimentally evaluated. Finally, it is shown that the addition of wood shavings to cement paste gives a composite with satisfactory mechanical strengths with respect to its weight and higher toughness in addition to environmental and economic benefits.

Experimental study of lightweight concrete used for the production of canoe

Dr.Eethar Thanon Dawood

Al-Rafidain Engineering Journal (AREJ), 2015, Volume 23, Issue 2, Pages 187-197
DOI: 10.33899/rengj.2015.101085

This study was conducted to investigate the properties of lightweight concrete produced by the inclusions of polystyrene beads and perlite that can be used for production of Canoe.Different percentages of polystyrene (20, 35, 50 and 65%) were used.Besides, the 50% of polystyrene beds with different percentages of perlite (10, 20, 30, 40, 50 and 60%) as partial replacement of sandwere used. The fresh density, compressive strength, flexural strength and absorption capacity of the mixes were tested. The results show that the uses of 50% of polystyrene with 50% of perlite as partial replacementof sand exhibit suitable ranges of density, compressive and flexural strengths of lightweight concrete used for canoe production. Thus, the Canoe produced from these inclusions of polystyrene and perlite show a clear success in terms of floating.