AlKhwarizmi Engineering Journal,
Vol.8, No. 3 (2012)
No. 
Author Name 
Title 
Abstract 
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1 
Hussain J. Alalkawi
Dhafir S. AlFattal
Abduljabar H. Ali

Types of the Fiber GlassMat on Fatigue Characteristic of Composite Materials at Constant Fiber Volume Fraction: Experimental Determination.

The aim of this work is to study the influence of the type of fiber glass –mat on fatigue behavior of composite material which is manufactured from polyester and Eglass (woven roving, chopped strand mat (CSM)) as a laminate with a constant fiber volume fraction (VF) of 33%. The results showed that the laminates reinforced with Eglass (woven roving) [0/90, ±45.0/90] and [0/90, CSM, 0/90] have lower fatigue strength than the laminates reinforced with Eglass [0/90]_{3},[CSM]_{3} and [CSM, 0/90, CSM] although they had different tensile strength; the best laminate was [0/90]_{3} .

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2 
Yousif Khalaf Yousif 
Experimental & Theoretical Analysis of Composite (Polyester & SiliconCarbide) Cantilever Beam.

A cantilever beam is made from composite material which is consist of (matrix: polyester) and (particles: SiliconCarbide) with different volume fraction of particles. A force is applied at the free end of beam with different values. The experimental maximum deflection of beam which occurs at the point of the applied load is recorded. The deflection and slope of beam are analyzed by using FEM modeling. MATLAB paltform is built to assemble the equations, vector and matrix of FEM and solving the unknown variables (deflection and slope) at each node. Also ANSYS platform is used to modeling beam in finite element and solve the problem. The numerical methods are used to compare the results with the theoretical and experimental data. A good agreement is observed between the above methods. The Increase in volume fraction of particles results in increasing the modulus of elasticity and decreasing the deflection of beam. An equation is suggested for modulus of elasticity as functions of volume fraction.

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3 
Hassan Ayad Fadhil
Ali Hussein Ali AlAhmed

Empirical Equations for Analysis of TwoWay Reinforced Concrete Slabs.

There are many different methods for analysis of twoway reinforced concrete slabs. The most efficient methods depend on using certain factors given in different codes of reinforced concrete design. The other ways of analysis of twoway slabs are the direct design method and the equivalent frame method. But these methods usually need a long time for analysis of the slabs.
In this paper, a new simple method has been developed to analyze the twoway slabs by using simple empirical formulae, and the results of final analysis of some examples have been compared with other different methods given in different codes of practice.

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4 
Rana Dhia'a AbduAljabar 
Design a Security Network System against Internet Worms.

Active worms have posed a major security threat to the Internet, and many research efforts have focused on them. This paper is interested in internet worm that spreads via TCP, which accounts for the majority of internet traffic. It presents an approach that use a hybrid solution between two detection algorithms: behavior base detection and signature base detection to have the features of each of them. The aim of this study is to have a good solution of detecting worm and stealthy worm with the feature of the speed. This proposal was designed in distributed collaborative scheme based on the smallworld network model to effectively improve the system performance.

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5 
Ahmed A. Hashim 
Sub–Nyquist Frequency Efficient Audio Compression.

This paper presents the application of a framework of fast and efficient compressive sampling based on the concept of random sampling of sparse Audio signal. It provides four important features. (i) It is universal with a variety of sparse signals. (ii) The number of measurements required for exact reconstruction is nearly optimal and much less then the sampling frequency and below the Nyquist frequency. (iii) It has very low complexity and fast computation. (iv) It is developed on the provable mathematical model from which we are able to quantify tradeoffs among streaming capability, computation/memory requirement and quality of reconstruction of the audio signal. Compressed sensing CS is an attractive compression scheme due to its universality and lack of complexity on the sensor side. 
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6 
Reem J. Channo 
Studying the Probability of Using Groundwater in Baghdad City for Human, Animal, and Irrigation Use.

Groundwater is an important source of fresh water especially in countries having a decrease in or no surface water; therefore itis essential to assess the quality of groundwater and find the possibility of its use in different purposes (domestic; agricultural; animal; and other purposes). In this paper samples from 66 wells lying in different places in Baghdad city were used to determine 13 water parameters, to find the quality of groundwater and evaluate the possibility of using it for human, animal and irrigation by calculating WQI, SAR, RSC and Na% and TDS indicators. WQI results showed that the groundwater in all wells are not qualified for human use, while SAR and RSC indicated that most samples are suitable for irrigation use, and TDS showed that 74% of samples are suitable for animal use especially for sheep and meatlivestock animals.

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7 
Zainab Yaquob Atiya 
Estimation of Volumetric Mass Transfer Coefficient in Bioreactor.

This study is concentrated to investigate the effects of aeration and stirring speed on the volumetric mass transfer coefficient (KLa). A dynamic technique was used in estimating KLa values in order to achieve the aim of this study.
This study was done in 10L bioreactor by using two medias:
1. Dionized water
2. Xanthan solution (1 g /L)
Moreover, the research covered a comparison between the obtained values of KLa.
The Xanthan solution was used because of its higher viscosity in comparison with water. It behaves similarly to the cultivation medium when organisms are cultivated in a bioreactor. Growth of organisms in the reactor leads to a change in the viscosity of the medium which affects the mass transfer.

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8 
Jasim M. Mahdi 
Natural Convection Heat Transfer in an Inclined OpenEnded Square Cavity with Partially Active Side Wall.

This paper reports a numerical study of flow behaviors and natural convection heat transfer characteristics in an inclined openended square cavity filled with air. The cavity is formed by adiabatic top and bottom walls and partially heated vertical wall facing the opening. Governing equations in vorticitystream function form are discretized via finitedifference method and are solved numerically by iterative successive under relaxation (SUR) technique. A computer program to solve mathematical model has been developed and written as a code for MATLAB software. Results in the form of streamlines, isotherms, and average Nusselt number, are obtained for a wide range of Rayleigh numbers 10^{3}10^{6} with Prandtl number 0.71 (air) , inclination angles measured from the horizontal direction 0º60º , dimensionless lengths of the active part 0.41 ,and different locations of the thermally active part at the vertical wall. The Results show that heat transfer rate is high when the length of the active part is increased or the active part is located at middle of vertical wall. Further, the heat transfer rate is poor as inclination angle is increased.

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9 
Sahama E. Salih
Mervit M. AlJnabi

Study of Mechanical Properties of (AlCuMg) Alloy Matrix Composite 
The present research had dealt with preparing bars with the length of about (13 cm) and adiametar of (1.5 cm) of composite materials with metal matrix represented by (AlCuMg) alloy cast enforced by (ZrO2) particles with chosen weight percentages (1.5, 2.5 ,3.5, 5.5 %). The base cast and the composite materials were prepared by casting method by uses vortex Technique inorder to fix up (ZrO2) particles in homogeneous way on the base cast. In addition to that, two main groups of composite materials were prepared depending on the particles size of (ZrO2) , respectively. 
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