Journal of Engineering and Sustainable Development (JEASD)

This work is an attempt to study the behavior of a laminated composite sheet when subjected to specific damage cases and harmonic load. The numerical investigation is developed using finite element method with 8-nodes shell element to determine the free vibration and harmonic response by using the ANSYS package. The investigation covers three cases of damage laminate composite sheet with center impact loading.
The work procedure was to model a healthy structure and apply different damage cases in reference to the health structure in order to compute the shift in the stresses distribution in different layers. Damage occurs in several layers of the composite sheet in multiple locations throughout its volume, and through several layers of the sheet.

Composite construction can be defined as the usage of different materials in an optimum geometric configuration with the aim that only the desirable property of each material will be utilized by virtue of its designated position.
This study is concerned with the behavior of continuous composite beams of reinforced concrete and steel shapes taking into consideration the non-linear behavior of the components of the composite section, i.e. (concrete, steel shapes, reinforcing bar, and shear connectors). A theoretical model has been presented to cover the full range of non-linear behavior of such beams allowing for differential movement at the interface i.e., slip and separation.
The compatibility and equilibrium equations have been derived and arrived at four differential equations in terms of four independent displacements. Finite difference method has been used to solve these equations. Comparing with the available experimental data, the application of the current model gives close prediction

Ground bounce technique is a self-screening or support Electronic Counter Measure (ECM) technique that consists of aiming the ECM antenna in a direction other than the tracking system’s direction in order to deceive the tracking system.
Ground reflection property can be used to deceive angularly a tracking system, either airborne or ground based. To achieve a deception to the tracking system, it is necessary to present to it a greater level of signal coming from the ground (after reflection) than from the aircraft direction.
This paper introduces the analysis of ground reflection of EM waves, parameters optimization of ground bounce technique, and a proposed dual mode of operation for an airborne ECM system.

Predicting of refrigerant mass flow rate in capillary tube is widely used in numerical simulation and designing of refrigeration and air conditioning systems, so the present study tries to compare the existing analytical and mathematical methods for predicting mass flow rate of refrigerant through capillary tube with experimental data published in previous studies. Assuming adiabatic, homogenous flow rate of refrigerant and neglecting the delay of vaporization region (metastable region) inside the capillary tube. The refrigerant R-22 is used in present study because of the wide range of experimental data and mathematical modeling methods that available.

The effect of time dependent compression of consolidation settlement is modeled by using the finite element formulation of the coupled field equations for deformation and excess pore water pressure generated by an increment of loading applied to a saturated soil is studied. This formulation is extended based on Biot's theory to include the partially saturated soil; the formulation has been developed by noting that air and water pressure in partially saturated soils are approximately equal at high degrees of saturation. This led to a relatively simple formulation which can have a range of practical applications.
The result shows that there is an influence of partial soil saturation on strip footings behaviour. Both partially saturated and conventional saturated finite element analyses are performed with the Modified Cam Clay Model presented in this study.

In this paper a new technique is proposed to improve the performance of OFDM. This technique uses the slantlet transform (SLT) instead of fast Fourier transform (FFT) to reduce the level of interference. This also will remove the need for guard interval (GI) in the case of the FFT-OFDM and therefore improves the bandwidth efficiency of the OFDM. The effect of PCC has been studied in both the traditional and proposed OFDM systems on frequency selective fading channel, flat fading channel and additive white gaussian noise (AWGN) channel.
Results obtained indicate that the performance of proposed SLT based PCC-OFDM is better than FFT based PCC-OFDM in flat fading channels (bit error rate reduces from 0.4343 to 0.0046 at SNR equals 10 dB). For frequency selective fading channel the results show that the performance of the proposed SLT based PCC-OFDM is better than the FFT based PCC-OFDM at low SNR values, while the performance is approximately similar in both systems at moderate and higher SNR values

The ball-on-plate balancing systems present a challenging design problem. In this study, the ball on plate balancing system has been analyzed. The main objective is to find a controller capable of controlling the ball position, and to tracking a certain preset complicated paths with precision and accuracy.
Two techniques are implemented in the design of this controller, full state feedback and output feedback. One of the modest methods is the Direct Eigenstructure Assignment, which is used for the first time in this study using MATLAB.
It has been shown that both regulation and tracking can be implemented in the Direct
Eigenstructure Assignment algorithm with ease. The results show that the overall method is
very quick and simple to use.

The aim of this paper is to investigate the effect of impulsive noise on the performance of the WPDM (Wavelet Packet Division Multiplexing) system. The employed model of impulsive noise consists of Bernoulli distributed impulsive arrivals and Gaussian distributed amplitudes of the impulses. The effect of changing impulsivity of noise and different relative power of impulsive noise are investigated and are compared with Additive White Gaussian Noise (AWGN) case. Also, the performance of a WPDM is compared with single carrier system.
The results show that wavelet transform is sensitive to impulsive noise and increase number of subcarriers effect badly on the performance system. Two regions are founded comparing with single carrier system, the first region in which the performance of single carries system is better than WPDM system when SNR smaller than 15 dB. The second region in which the performance of WPDM system is better than single carrier when SNR higher than 15 dB.

This study is conducted to design a hydraulic dynamometer to assay a high power engines by employing the tapered land thrust bearing for absorbing engine power. The project is an attempt to design a dynamometer device, which could be used in the libratory of industries.
The design work involves a theoretical approach based on finite element analysis for
the main parts of this hydraulic dynamometer which are the spline hollow shaft, the
tapered–land thrust bearing and selection oil cooling system.
The results show that the shaft length = 0.6 m and diameter ratio (Do/Di) =1.5 for outer diameter Do= 0.1524 m with 18–spline teeth which represents the hollow splined shaft. While for the thrust bearing the diameter ratio (do/di) =1.28 for inner diameter di = 0.1778 m and bearing thickness = 4 mm with numbers of bearing pairs = 40 and using oil type VG 22 as lubricant fluid with dynamic viscosity = 13 cp at 50 ْC

Code Division Multiple Access (CDMA) suffers from multi-user interference (MUI), and intersymbol interference (ISI) under frequency selective multi-path fading channels. Orthogonal Frequency Division Multiple access (OFDM) is MUI free but achieves lower diversity than CDMA system employing the same error control coding. Merging the advantage of OFDM and CDMA to minimize MUI and enable maximum available diversity for every user, multi carrier code division multiple access (MC-CDMA) is used.
In this paper the performance of group orthogonal multi-carrier code division multiple access (GO-MC-CDMA) system using multi-user detection is evaluated by simulation over two-paths frequency selective Rayleigh fading channel. Simulation results show that successive interference cancellation is better than parallel interference cancellation for higher signal-to noise ratio (SNR)

A Numerical study of two-dimensional, turbulent, incompressible fluid flow through manifold pipe that divides flow to five consecutive laterals is carried out. Each lateral is oriented at ninety degree to manifold axis. The study is based on the solution of the elliptic partial differential equations representing the conservation of mass, momentum, turbulence energy and its dissipation rate in finite volume form. The turbulent viscosity and diffusion coefficients are calculated using the (k-ε) model. Different parameters are considered to illustrate their influences on the flow distribution along manifold. These parameters include the area ratio (the ratio of the sum of areas of all laterals to manifold area) (A.R), curvature radius at the junction points between manifold and laterals (R), and space between each two consecutive laterals. The results show that the area ratio has a significant effect on flow distribution along manifold pipe and as a result of these effects the discharge through laterals near from uniform as the area ratio becomes less than unity (A.R<1), while when area ratio becomes larger than unity (A.R>1) the discharge distribution through laterals is far from uniform (flow rate through the last lateral will be greater than the flow through the first lateral), especially for short manifold (L/D≤10) and sharp-edged laterals.

Concrete works are suffered from many problems like the selection of materials used, mixing, placing, compacting, and curing of concrete. These stages of manufacturing concrete affect the quality of produced concrete. Also, there are many difficulties in converting the proportioning of concrete mixes by weight to the proportioning by volume. Moreover, the tables used to estimate the quantities of materials needed to produce one cubic meter of concrete must be studied carefully to reduce the errors in estimation. This research aims to introduce the solution for the problems mentioned above and provide the engineer with a guide for the calculations of construction materials.

In this study, the importance of the quality management system for companies has been studied, where the quality guarantees the emulative position of the company with other companies in the same field. The study describes the mechanism for the company accreditation according to (ISO 9000-2000), which regards as the specifications concerned with the quality management system (QMS). So, when the company owns the (ISO 9000-2000), it proves it has its own good management system for all activities. Also, the researcher describes the strategies for the application of the quality management system in Iraq and the required recommendation for the company's commitment with the quality concepts in all activities and its role in economical development.

The place is considered one of the principles of the architectural act and the background to be formed on. That the place in architecture has multiple images like architecture itself, as each architectural movement has its own understanding of place, its imagination, and its performance in the architectural act. Architecture is dealing with place concept in two formulas: First Formula: Architecture is a representative and expressionist of the place. Any differentiation is in the expressional representation form rather than canceling the expression. The variance, hence, is in the practice rather than the concept, and the Second Formula: is the architecture represented and situated in the place, so it is the space of the performance of the architectural act. This paper is an attempt to develop formulas for the place expression in architecture and the possibilities that could be found. It reveals that the concept of place in architecture could be in three dimensions. First Dimension: All of that could be related to the geometry of the place, which could be referred to as Geometrical place, and Mathematical place. Second dimension: All of that could be related to the physical status of the place with respect to the form of place, which could be referred to as the Place limit, and Framework of the place. While Third Dimension: All of that could be related to the semantics of the place with respect to meaning and expression values, which could be referred to as Expressionism of the place, and Intent of place.