A new type of perfobond shear connector is suggested, and tested through design and construction of six steel-concrete composite beams separated on three groups formed from standard steel section (W4X13), with total length of 1300mm. The concrete slab connected to steel section by using three types of mechanical shear connectors namely; stud connector and regular circular hole perfobond connectors in addition to newly suggested type of triangular hole perfobond connector. The beams are experimentally tested using two point load beam test to inspect the effects of connector’s type on beam behaviour at yielding and ultimate stages in terms of deflection at mid-span and slip at ends of tested beams. A three dimensional nonlinear finite element model is developed using ANSYS software to simulate beam test up to failure. The results show that, composite beams constructed with newly suggested triangular perfobond connectors developed a strength percentage higher than those with stud connectors, and regular circular perfobond connector. The finite element model validated by comparing with experiments, predicting differences in ultimate resistances of (0.9% to 5.7%) for perfobond connectors and (11.9% to 19.2%) for stud connectors. Keywords: ANSYS, Connector, Composite, Finite Element, Perfobond, Stud

Wireless ad-hoc networks with different topologies proved to be a feasible solution for low-cost deployment of computer networks. It provides quick and easy networking in circumstances that require temporary network services or when cabling is difficult to be installed. In this paper, an analytical model of a wireless ad-hoc network is presented, in addition, a new model for wireless ad-hoc network with a sub-layer MAC is designed using Simevents tools. It is also taken into account the effect of the contention process and losses on the sub-layer MAC, then OPNET software is used to validate this model. Finally, the results of a practical single-hop wireless ad-hoc network using six computers are compared with the results of the proposed models. It is obvious that there is an excellent agreement between the throughput performances of the different models. Key words: Wireless, Ad-Hoc, MAC, Simevents.

In this paper the hydraulic characteristics of branching flow in open channel has been studied, a main channel was used with a branching channel connected with three angles (30°, 60°, 90°) with four bed slopes (0.001,0.0015,0.002,0.0025)and at each slope five values of discharge were pass in the mainchannel(13, 14, 15, 16 and 17.25) l/s. For each discharge five depths of water were allowed in the branching channel in each experiment. The results of the experiments indicated that the discharge ratio increases with increases bed slope of the branching channel. It was also found that the highest discharge ratio is obtained in the angle 60° then the angle 90° and then angle 30°. The results also showed that the relationship between thedischarge ratio and Froude number is linear and direct proportional to the Froude number in the upstream main channel and in the branching channel, and inversely with the Froude number in the downstream main channel. The relationship between discharge ratio and the ratio of water depth in the branching channel to water depth in the downstream main channel is linear and inverse. An empirical equation to calculate the discharge ratio was observed, with a coefficient of determination (R2) equal (0.953). Key Word: Branching channel, Branching channel slope, open channel, Branching flow and Branching angle.

The aim of this paper is to analysis and optimizes the efficiency of the Enhanced Data rates for GSM Evolution (EDGE) Quality of Service (QoS) profilewhich is used for Packet Data Protocol (PDP) context in data transfer over GSM/EDGE networks.Two software tools were used in the practical part: the first one is a Subscriber Management Unit client (SMU/9820) from HUAWEI Technologies Co., Ltd. that is a real time system for mobile network management in HUAWEI Home Location Register (HLR); the second is a DUMETER 5.02, which monitors the network traffic and displays a real time charts. The practical part has been achieved in Asia cell telecommunications Company in three different cities; Mosul, Duhok and Erbil: each one in three levels; the first level is the analysis of available QoS in the network, based on the default profile which depended by the network. However, 24 testing have been recorded; this testing has been repeated for three cities. In second level a hundreds of tests and optimization implemented on tens of QoS and PDP parameters in order to reach better data rate. Final level includes the implementation of the proposed profileswhich resulted from second level. Finally, the proposal profiles improved the performance of the QoS which reflected the gains of 34% in average data rate in the three cities. Keywords: HLR, GSM, QOS, ED

The aim of this research is to assess the mechanical strength and durability performance of the concrete incorporating various contents of the ordinary Portland cement and w/c. Besides, it has been undertaken to study the effect of curing methods on compressive strength of the concrete as well as the physical properties, which are investigated in terms of density, absorption and volume of permeable voids as an (porosity). Many researchers consider these physical properties as an indicating signs on the permeability of the concrete, or in other words, they were as an indirect method to measure the permeability and to evaluate it. Five mixes are prepared and tested at the age of 28 days. The concrete specimens are cured in two different methods, in the first method specimens are moist cured while in the second method the specimens are air cured at 20 ˚C and 80% relative humidity to examine the effect of curing regimes. An experimental procedure for testing the physical properties of concrete is carried out according to ASTM (C 642-97). The results of the study showed that the increase of cement content and the reduction in the w/c leads to more durable concrete because of loss of absorption and porosity characteristics, in addition to that, higher density and compressive strength. Test results also showed that the water curing method have significant effect for improving the strength and durability performance of the concrete. Keywords: Concrete, Mix Proportion, Curing Conditions, Durability Performance, Physical Properties.

The objective of this study is to estimate the influence of web openings in reinforced concrete deep beams by using nonlinear finite element analysis. Concrete represented by isoperimetric eight nodes, serendipity plane stress, elements. The reinforcement treated as embedded elements and considered as elastic perfectly plastic. New constitutive models to simulate concrete material suggested by means of a nonlinear regression analysis of many experimental data by using SPSS 16 – statistical program. Strain hardening approach was employed to model the compressive behavior of high strength concrete. In tension two models were used to model high strength concrete in the pre – peak and post peak states. A smeared fixed crack approach of cracked concrete in tension is assumed. Three variables included concrete strength, shear span – to – depth ratio and the width and depth of openings. The results indicated that the ultimate strength is remarkably decreased in deep beams with openings rather than deep beams. Experimental results for reinforced high strength concrete deep beam with openings compared with the finite element results and showed good agreement. Keywords: Deep beam, Finite element, High strength concrete, Nonlinear analysis, Openings, New constitutive models.

In this paper, second order structures satisfying single-multiplier digital sine-cosine generators are derived analytically, resulting in four different realizations. Some important characteristics of these generator structures, like total harmonic distortion percentage (THD%), frequency error ( and frequency resolution are defined and examined as performance measures. The four generator realizations are simulated using Matlab7.0 program. The simulation results show that better performance (THD% and are very low or negligible) can be obtained for these realizations by using 32 bits to represent the single-multiplier coefficient and other the outputs of arithmetic operations. The rounding-off method is applied as a quantization process after multiplication process. A comparison is made between one of the best-derived structures and other two recent structures implemented in previous researches. The comparison results indicate that better performance measures can be achieved from the proposed realization for the single-multiplier digital sine-cosine generator.

This paper presents the design of Delta-Sigma ΣΔ based fractional N PLL frequency synthesizer for GSM mobile systems. The loop filter is one of main element in fractional-N ΣΔ synthesizer because it shapes the noise spectrum of quantization error and reduce the spurious level in the pass band of PLL. The effect of loop filter order is studied and it is shown that by increasing the order of the loop filter, the phase noise performance will be improved, although this requires careful design consideration, as the PLL is prone instability. It's shown that the 3rd order loop filter and 3rd order ΣΔ modulator gives the best performance with reducing phase noise (13dBc/Hz ) and spurious noise (44dBc) of the output signal. - Keyword: PLL, Frequency Synthesizer, ΣΔ Modulator, Fractional-N, GSM mobile systems.

The conventional methods - used for - measuring brake, friction, and indicated power are based on brake - off dynamometers which use hydraulic or electrical dynamometers . The mentioned above methods use the measured torque to calculate the related power. The present method and instrument are characterized by measuring the amount of pressure opposed by a compressor joined to the engine and a reservoir for a compressed air, thus; the engine speed decelerates with the increasing pressure . For a specified pressure and engine speed, power could be calculated. In addition, friction power in the engine could be estimated by measuring the consumed current and effective voltage on an electrical driving motor when the diesel engine at run – off situation; no fuel supply. The whole present dynamometer had been designed and performed by the researcher as explained.

In this paper the energy dissipation was studied using stepped spillway, in addition to that the elimination of air pockets which take place at steps was also studied by using obstructions along the edge of steps. These obstructions were made from iron with square cross-section. Several experiments were conducted on stepped spillway with and without obstructions. The results of the experiments showed that these obstructions were very successful in eliminating air pockets. Their present in general had a positive effect on energy dissipation along the stepped spillway. The results also indicated that the use of these obstructions should be started from second step until the middle step of the spillway. Keywords: stepped spillway, obstructions, energy dissipater, open channels, discharges.