Journal of Engineering and Sustainable Development (JEASD)

Wireless communication systems play an important role in our life and society. In this paper, the different types of wireless communication systems Single Input-Single Output (SISO), Single Input-Multiple Output (SIMO), Multiple Input-Single Output (MISO), and Multiple Input- Multiple Output (MIMO) were described and compared from capacity and Bit Error Rate (BER) point of view. It was found that the capacity of MIMO communication system is better than other systems. An additional improvement was obtained by using Space Time Coding (STC). Space Time Block Code (STBC) improve the BER of MIMO by (78,6%), and Space Time Trellis Code (STTC) improve the (BER) at the receiver side by (91.37%). Also the use of Artificial Neural Networks (ANN) improve the STTC MIMO communication system by 54.16%. All measurement are done at SNR = 8dB. Using MATLAB version 2013a.

The land scape is subjected to higher temperature during the last three decades became of "Globule warming", which became high evaporation of surface water, in addition to the increase in salt content , because of the unaffected irrigation way, of planets and the increase in the capillarity action which contribute with this process. This may led to the dissolution of salts inside soil and its appearance on the ground surface, with different depths. The NaCl salt is one of the most common salts presence in widely areas in Iraq, which has high dissolution rate in water. The problem of such soils appear when subjected to miniaturization from any source, resulting high dissolution rate of the salts in side soil skeleton, which lead to the weakening of soil, cavities may appear inside soil layer, and so it may led to failure of structures constructed on it.This study includes the feasibility of improving the collapsibility of natural saline soil with 10% salt percent, brought from, Jurf Al-Milih region in Diyala Governorate, by mixing it with randomly distributed nail reinforcement, with three different lengths "Ln", related to width of footing "B" , (Ln/B=11%, 14.2% and 21.4%). By carrying settlement test for single model footing with time, for treated and untreated model using this technique at both dry and wetting conditions, using locally manufactured Laboratory model. This technique reduce the collapsibility of such soil, 27%.The study includes also the effect of mixing....

This paper present a simple method for reducing the linear higher order systems. The coefficient of the reduction model is obtained by using the modified dominant pole technique, while the coefficients of the numerator are obtained by reduced order model. Linear Quadratic Regulator (LQR) is used to design a controller for the higher order system depended on the linear reducing equations. LQR without and with integral effect method are used and compared for controlling the higher order systems. The LQR controller are designed and simulated using MATLAB/Simulink. Simulation results show that both the controllers are capable of controlling the systems successfully. The LQR with integral gives the better performance, compared to when the system without it. the LQR controller scheme with smith predictor connection is suggested in order to maintain the stability of the higher order plant in addition to improve the performance of the controlled system. The simulation results for this scheme are tested with two higher order time delay systems to illustrate the efficient performance for the proposed control scheme.

Ultraviolet photodetectivity in ZnO thin films deposited by sol-gel technique based metal-semiconductor-metal (MSM) photodetectors is investigated. Effect of optical power level of UV radiation and bias voltages on the photoresponse behavior is studied. A two different photodetector configuration comprising, ZnO thin film embedded with microisland metals like Al and Ni were designed and tested. Photoresponsivity was found to be better for the Ni microslands embedded ZnO film as compared to those using Al microisland embedded ZnO thin films. The devices exhibited maximum photoresposivity at 150μW above this value the devices attend to saturate. Ni/ZnO embedded Ni microislands sample exhibits highest quantum efficiency of 214% whereas Al/ZnO embedded Al microislands sample structure presents highest sensitivity of 94%. Devices based on Ni microislands embedded films exhibited gain compared to Al microislands embedded films. Enhancement in the quantum efficiency of Ni/ZnO embedded Ni microisland is attributed to the devices have higher responsivity due to the difference in work function and oxygen affinity values of Ni with the ZnO thin film layer. The study also revealed that the all devices showed a maximum photo-response at flat band voltages of MSMs.

The aim of this work is to study the behavior of reinforced concrete hollow beams under torsion load. The experimental work includes investigation of eight reinforced concrete rectangular beams of dimension (length 2000 x height 240 x width170 mm) with the same reinforcing ratios, tested under pure torsion. Two beam sections are provided: solid and hollow section with varied shape and percentage (circular 18%, rectangular 18% & 27% of total cross section area of beam). Variables considered in the test program include; effect of hollow shape & area and concrete type (normal and high strength). Test results were discussed based on torque - twist behavior, beam elongations, behavior and influence of hollow core on cracking torque, ultimate torque and failure modes. Test results indicate that the ultimate torque for hollow sections is about 89% for Circular ( hollow ratio 18%) and 83% and 60% for rectangular, of hollow ratio 18% & 27% respectively of solid beam. The high strength concrete type in solid beam gave an increase in the cracking and ultimate torque by about 100% and 66% respectively and an increase in the ultimate torque was observed by about (63%, 60%, 62%) for circular (18% ratio), rectangular (18% ratio) and rectangular (27% ratio) respectively.

Utilization of waste material in asphalt pavement would be beneficial in order to find an alternative solution to increase service life of asphalt pavement and reduce environmental pollution as well. One of these waste materials is plastic water Bottles(Polyethylene Terephthalate) (PET) which are being produced in large amount. In this research Polyethylene Terephthalate (PET) was used to investigate the possibility of using waste plastic bottles made of Polyethylene Terephthalate (PET) was used as polymer additives in Bituminous Mixture to overcome the pavement problems . Added five different proportions of (PET) in ( 2%, 4%, 6%, 8% and 10%) by weight of optimum bitumen to prepare the specimens . The tests include the determination of bulk density, stability and flow. Marshall Mix design requires the determination of the percentages of air voids and air voids of mineral aggregate. The results indicated the optimum modifier content was found to be )8 %( for Waste plastic water Bottles(PET) modified asphalt mixture . It is found to give the maximum stability, VFA ,stiffness and minimum flow, Air Voids (AV), compared to the non-modified mixtures and gave better resistance against permanent deformations and better engineering properties

Ten of reactive powder concrete (RPC) T- beams, 1300 mm length, 100 mm web width and 160 height, with different type of section (hollow and Solid) tested under pure torsion to study the significant effect of concrete core and steel fiber percentage on crack and ultimate torsional capacity. An increase of 191% and 64% for solid section and 174% and 59% in for hollow section respectively was achieved when increasing steel fibers percentage to concrete mix from zero to 2%, as longitudinal and transverse reinforcement ratios were kept constant (ρl=0.01, ρs=0.02). The result indicate that the concrete core has no significant effect on the ultimate torsional strength and beam elongation.

Reactive powder concrete has superior mechanical and structural properties but the major drawback of this new construction martial is its high cost. This research presents experimental study to investigate flexural behavior of hybrid tee beams and study the ability of using normal strength concrete together with RPC in the same section to exploit the advantages of these two materials in optimal way. The experimental results showed that using RPC in the web and normal strength concrete in the flange effectively enhanced performance of hybrid T-section beams when compared with normal strength concrete T-beam, however, the increases in the first crack load, ultimate flexural load and ultimate deflection were 86.67%, 60% and 29.19% respectively, while, the increases for the case of using RPC in the flange and normal strength concrete in the web were 20%, 34.28% and 14.97 respectively when compared with normal strength concrete T-beam

Shot peening is one of the common cold working processes that used to improve the fatigue life of the metals. But, studying the effect of this process on the variation in properties of composite material is still insufficient. This work was investigated the effect of shot peening with three different times of 2 min, 4 min and 6 min experimentally on fiber glass (E type) with polyester with constant volume fraction of 33 %. The results showed that the best improvement obtained in the endurance limit was at 6 min shot peening time with a percentage of 25 % more than that of without shot peening. While the improvement in mechanical properties (ultimate stress) was obtained by 5 % at shot peening time of 6 min. The verification of experimental results was done using ANSYS.14 workbench with a percentage of error not exceed 4.68 % in behavior between the experimental and numerical where the maximum error does not exceed 5%.

This investigation presents an experimental study of strength and behavior of Modified Reactive Powder Concrete (MRPC) corner subjected to bending moment tended to open the angle. Twelve specimens are tested to study the corner strength, cracks types, cracking moment, cracks patterns, corner deflection, ductility and corner efficiency. Ten MRPC knee joints were mixture of steel fiber, superplasticized, silica fume-cement blended with very low water/cement ratio (w/c) characterized by very fine sand (maximum size 600µm), where the presence of natural crushed aggregate of maximum size (4.75mm) was used to replace a part of the fine sand. The rest two corners of Normal Strength Concrete (NSC) which are the mixture of (1:1.5:3) (cement : sand 4.75mm : gravel 10mm). The specimens are designed to represent an actual prototype of a portal frame corner. The compressive strength of concrete in the test varies from (23.5) to (88.9) MPa, and steel tension ratio in legs is constant, ρ = 0.008, for ten specimens where the two MRPC corners are plain concrete. The specimens are designed to represent an actual prototype of a portal frame corner. The nominal dimensions of the tested corners are (1078 mm) in overall length, (600 mm) in height, the cross section of the corner is rectangular (212×150mm). All corners are supported to be hinged in one leg by two clamps and rolled in other leg, also all corners are loaded by steel frame where,......