https://journalofbabylon.com/index.php/JUBES/issue/feed Journal of University of Babylon for Engineering Sciences 2019-02-20T16:45:49+00:00 Info. info@journalofbabylon.com Open Journal Systems <p style="text-align: justify;"><span style="font-size: 12pt;"><strong><span style="color: #2969b0; font-family: Georgia, serif;">J</span></strong><span style="font-family: Georgia,serif;">ournal of&nbsp;<strong><span style="color: #2969b0;">U</span></strong>niversity of&nbsp;<strong><span style="color: #2969b0;">B</span></strong>abylon for&nbsp;<strong><span style="color: #2969b0;">E</span></strong>ngineering&nbsp;<strong><span style="color: #2969b0;">S</span></strong>ciences&nbsp;<strong>(<span style="color: #2969b0;">JUBES</span>)</strong> is a peer-reviewed open access journal, monthly publishing high-quality research and review papers covering all aspects of recent advances in engineering dealing with:&nbsp;&nbsp; </span></span></p> <ul> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Electrical Engineering</span></li> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Mechanical Engineering</span></li> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Material Engineering</span></li> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Civil Engineering</span></li> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Chemical Engineering</span></li> <li class="show"><span style="font-family: Georgia, serif; font-size: 12pt;">Architectural Engineering</span></li> </ul> <p><span style="font-family: Georgia, serif; font-size: 12pt;">&nbsp;ISSN:&nbsp;<strong>‎<a href="https://extranet.issn.org/resource/issn/2616-9916#" target="_blank" rel="noopener">2616-9916</a></strong></span></p> https://journalofbabylon.com/index.php/JUBES/article/view/1967 Design Blocks in Simulink to Detection Singularity in the Workspace of Gough-Stewart Robot Manipulator 2019-02-20T16:45:49+00:00 Hassan Mohammed Alwan 20071@uotechenology.edu.iq Riyadh Ahmed Sarhan me.21328@uotechnology.edu.iq <p style="text-align: justify;">This work deals with Gough-Stewart robot manipulator, which has six degrees of freedom, six actuators, fixed base, and moving platforms. Here, the Jacobian matrix derived to detect the singular point in the workspace for manipulator at determinant of Jacobian matrix equal to zero, then derived the equation of motion from the dynamic analysis by Lagrange method to verify the singular points with Jacobian where the forces increase rapidly at this point. Finally, design blocks in Simulink include the Jacobian matrix and the equations of motion to detection the singularities at any time for current input parameters (X, Y, Z, α, β, γ), where the determinant of the Jacobian equal to zero at maximum forces.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1968 Temperature – Potential Evapotranspiration Relationship in Iraq Using Thornthwaite Method 2019-02-20T16:45:49+00:00 Hussein Ilaibi Zamil Al-Sudani dr.hussein_alsudani@yahoo.com <p style="text-align: justify;">One of the most important outcomes in the water balance equation for any natural area or water body is Evapotranspiration and it is also a crucial component of the hydrologic cycle. The relationship of temperature - evapotranspiration was obtained using the Thornthwaite method in Iraq by dividing the area into (7) sectors according to geographic latitude. Each sector has multi meteorological stations where (32) stations were used with different periods of records. A mathematical relationship was obtained between mean temperature and corrected potential evapotranspiration (PEc) with (97.45) to (99.84) coefficient of determination. Mean temperature has a symmetrical decreasing pattern from south-east towards north-west of Iraq affected by Mediterranean Sea climate conditions, while correcting potential evapotranspiration (PEc) has the opposite direction of increasing values due to a direct relationship with temperature.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1969 The Effect of the Constants and Variables of the Architecture of the Holy Shrines in the Adjacent Urban Fabric 2019-02-20T16:45:49+00:00 Mahmood Rezooky Hamid Mjanjun875@gmail.com Almamoori Hamza ALmamori-almamori@yahoo.com <p style="text-align: justify;">Among the constants of holy attba building is the connection of its architecture with the values of the Islamic religion and the number of visits and the number of visitors to it. Time has passed and visitors are in a state of increasing, so their founders have taken the decision of change and development previously, which was compatible with the increase in numbers and maintaining the constants of the sacred architecture. The adjacent fabric changes according to the change in its holly architecture, and the adjacent fabric forms one unit with its attba, maintaining its shape for centuries. In the 1930s, its fabric was affected by the decision to demolish the walls of cities in general, including the holy cities, to open roads to facilitate the traffic movements of cars and the arrival of visitors with high speed as planned at the time. The Research problem despite&nbsp; the development of master plans for the Holy City cities because of the increase in the number of visitors, but did not solve the problem required. The aim of the research is to identify the visitor, the activities of the visitors, the spaces occupied by the activities, the religious and ideological activities, as well as the cultural and social activities, an important criterion in the holy attba building and its adjacent fabric, which has been affected by the increase of visitors and which is no longer sufficient for the activities generally been done throughout the year.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1970 Stabilization of Soils Using Chemical Admixtures: A Review 2019-02-20T16:45:48+00:00 Mohammed N J Alzaidy mohammednawaf@uomosul.edu.iq <p style="text-align: justify;">Searching for the best soil stabilizer to overcome problems occur by the soft soils are still<br> being the main concern, not only to achieve the required soil engineering properties but also by<br> considering the cost and the effect to the environment. This review paper presents the results of experimental researches on soil stabilization by using the most chemical admixtures, which involved cement, lime and fly ash, and their effectiveness in the engineering properties of soil. Based on the literature review, the results show that addition of these chemical additives lead to significant improvement in workability, strength, durability and mechanical behaviour. On the other hand, it lead to a reduction in shrinkage, plasticity, compressibility and swell characteristics of soil. Also, the curing duration had significantly improved the strength properties of the stabilized soil with chemical additives. Using of each chemical additive and its suitability for a specific soil is highlighted in the research.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1971 Theoretical Framework for Design Recruitment Strategies In The Process Of Self-Healing Of Individuals 2019-02-20T16:45:48+00:00 Ghada Mohammed Younis Ghada_my65@yahoo.com <p style="text-align: justify;">The concept of self-healing based on characteristics of environment design of surrounding the individual ,Healing by design, one of the most important concepts corresponding to the healing environment or healing in the context of healthcare buildings, where the awareness of this concept reach on the characteristics of internal environment in general to make it more&nbsp; healthy, stimulating and vital, the concept of self-healing is result of analyzing the mutual and vital relationship between human and physical and natural environment in an attempt to understand the relationship and the extent of its repercussions on the physiological and psychological level of the individual. The process of healing&nbsp; cannot be understood by isolation from the factors that work dynamically in the life of individual ,and&nbsp; function of the building is not limited to housing and containment of activities and to meet functions of life, but the most important role is to improve the performance of vital act of&nbsp; life and make it healthy and support self-healing. Hence, the problem of research in the awareness of importance of architecture in taking the task of stimulating self-healing for the individual, and identify characteristics of design approach based on the design processes resulting from the dynamic relationship of the individual's living with the environment. The object of the study is to build a theoretical framework of design recruitment strategies in the process of self-healing of individuals Both for therapeutic environment and general internal environment, and to derive the possible values ​​of the design characteristics that achieve those strategies stemming from the mechanism of involving the individual in a conscious and clear process of support, balance and moral nutrition in relation to the environment. The basic and secondary vocabulary and possible values ​​of the conceptual framework for the strategies of design recruitment in the healing process were three basic strategies: strategy of environment potential supporting of individual, strategy of balancing the life components of the individual and experiment of space transition, and finally the nutrition strategy at the vital and poetic level of individuals. The conclusions were based on objective understanding of the quality of design that supports the process of healing, which is completely different from the concept of design in dealing with static and formal assets. The design here is characterized by the dynamic nature of healthy lifestyle design based on stimulating the process of healing at organic, sensory and moral levels for individuals.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1972 Vibration Analysis of Uniform and Tapered Composite Beams with Embedded Shape Memory Alloy 2019-02-20T16:45:48+00:00 Qasim Abbas Atiyah 20044@uotechnology.edu.iq Ammar Saleem Hameed 20086@uotechnology.edu.iq Baqer Jabbar Assi baqer92jabbar@gmail.com <p style="text-align: justify;">In this study, laminated composite materials were hybridized with E-glass fiber and Nitinol (Nickel-Titanium) wires. Hand lay-up technique was used to prepare the samples, epoxy resin type (Sikadur 52 N) was used as matrix reinforced by one fiber from E-glass fiber woven roving with embedded nitinol wires with a diameter 0.5 mm for samples and number of wires such as 0, 1, 3, 5 and 9 to find the effect of the number of wires on the natural frequency. The samples were fixed as a cantilever beam. The effects of increasing the number of nitinol wires, the diameter of nitinol wires, the length of the cantilever beam and the thickness of beam on the natural frequencies of the beam were studied. Also, the effects of the tapered in width side and thickness side on the natural frequencies of cantilever beam were studied. The results showed that the increasing in the number of nitinol wires and the diameter of nitinol wires lead to decrease the natural frequency in martensite phase and increase the natural frequency in austenite phase. Also, the increasing in thickness of beam and width ratio of the beam lead to increase the natural frequency. As well as, the increasing in the thickness ratio leads to increase the first natural frequency and decrease the second and third ones. In addition, the increasing in the length of the beam decreases the natural frequency.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1973 The Effecting of Physical Properties of Inorganic Fillers on Swelling Rate of Rubber Compound: A review Study 2019-02-20T16:45:47+00:00 Salih Abbas Habeeb salihabbas61@yahoo.com Zoalfokkar Kareem Alobad mat.zoalfokkaralobad@uobabylon.edu.iq Muayad Abdulhasan Albozahid mat.zoalfokkaralobad@uobabylon.edu.iq <p style="text-align: justify;">The purpose of preparing the review manuscript is to highlight the importance of the physical specifications of the most important of inorganic fillers such as "carbon black" and "silica" that have good physical specifications as surface area, particle size distribution and surface chemistry. Moreover, study the effect of these specifications on the resistance of vulcanized rubber compound for swelling, which is one of the disadvantages to determine the expansion of its uses in industrial applications through the review of many types of research in this area. The results proved that there is a strong relationship between the curing characteristics of the rubber compound such as the time of curing, the scorch time in addition to the "curing rate index' (CRI) and mechanical properties especially the tensile strength and "density of cross-links" for reducing the swelling rate to the minimum. By increasing the "density of cross-links" and improve the specifications of vulcanization and mechanical specifications.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1974 The Effect of SiC Addition on AlNi Compact Mechanical Properties Produced Via Powder Metallurgy 2019-02-20T16:45:47+00:00 Ali Hubi Haleem alialihhhobi@gmail.com Nawar Fahem Kadhem alialihhhobi@gmail.com <p style="text-align: justify;">This research directed to produce Al-Ni alloys by powder metallurgy technique since of its marketable and industrial significant. Nickel and aluminum powders were determined their particle size then the powders mixed and blended with percent (Al - 20% Ni). Silicon carbide particles (SiC) powder supplemented to master alloy powder by percent (4-6- and 8 wt. %) separately then these powders mixed to obtain homogeneous distribution, then the powders compacted in cold pressure at 700 MPa. The sintering procedure was performed at (530°C) for 8 hrs. At vacuum atmosphere (10<sup>-4 </sup>torr). After cooling these samples grinded and polished to estimate microstructure, density, porosity, LOM, SEM, EDS, X-ray diffraction ,hardness and wear tests at dissimilar circumstances. Results showed that the hardness increased by (52%) and wear rate decreased by (55%) at 8 wt % silicon carbide addition, and it was the best results.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1975 Effect of Heat and Mechanical Treatments on Mechanical Properties of Al-Zn-Mg-Cu Alloys 2019-02-20T16:45:47+00:00 Fouad El Dahiye Yahya.netawy@gmail.com Mahmoud AlAssaad Yahya.netawy@gmail.com Mohamad Yehea Alnefawy Yahya.netawy@gmail.com <p style="text-align: justify;">In this research the effect of various heat treatments on tensile properties and hardness of Aluminum-Zinc-Magnesium-Copper alloy (7075 Aluminum alloy) was studied, with and without mechanical treatment by extrusion process. The 7075 alloy samples were submitted to two type of heat treatments, T6 heat treatment by artificial ageing samples in 120 ºC for 24 h and retrogression and re-ageing (RRA). Where in RRA treatment the first ageing done in 120 ºC for 24 h, then the retrogression done in 180 ºC for 30 min and re-ageing in 120 ºC for 24 h. We got the best results by apply the RRA treatment with extrusion process, where tensile strength was reached to 380 Mpa without extrusion machining process, while reached to 530 Mpa with extrusion process</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1976 Energy and Exergy Performance Calculation of Solar Photovoltaic/ Thermal Hybrid System under the Baghdad Environment 2019-02-20T16:45:46+00:00 Dheya Ghanim Mutasher dr.dheya@gmail.com Mohammed Fowzi Mohammed Mohammed2007msc@yahoo.com Zaid Salman Obaid zaid.sal87@gmail.com <p style="text-align: justify;">A combined system with photovoltaic panel modules, which extracts heat from water or air and produces thermal and electrical energy which is called a solar photovoltaic or solar thermal photovoltaic thermal (PV/T) system. A way to enhance the electrical efficiency of the PV module is by diminishing the temperature at which the module is working, i.e. by extracting thermal energy. The design of the solar Photovoltaic/Thermal provides certain advantages. When the temperature is increased 1°C, the photoelectric efficiency decrease by 0.5%. This work is principally aimed to clarify the effectiveness by means of the exergy generated in a PV/T hybrid water module, a photovoltaic thermal module, generating thermal and electrical energy. Were determined the energy, exergy and the efficiency of the power conversion for a certain amount of days in function of the solar intensity, the temperature of the module and environmental temperature. During the hours 9:00 am to 3:00 pm, the efficiencies of exergy and power conversion varies according to the following values, between 2.16 - 12.27% for the exergy efficiency and between 5.2 - 11.2% for the power conversion efficiency as well as, the energy efficiency varies between 6.89 – 14.9%. The temperature of the photovoltaic module has a great impact on the electrical, thermal and exergy efficiencies. Moreover, these efficiencies can be enhanced by removing energy in form of heat from the surface of the photovoltaic module.</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1977 Study the Effect of Diameter and Depth of Parabolic Dish Collector on the Concentration Ratio and Temperature Amount of Solar Tower Receiver 2019-02-20T16:45:46+00:00 Sattar Aljabair drsattar2017@gmail.com Laith Jaafer Habeeb laithhabeeb1974@gmail.com Ameer mohammed ali ameeralmayahi@yahoo.com <p style="text-align: justify;">This work introduces three models of parabolic dish collectors with different dimension to study the effect of change diameter and depth of the dish on the position of focus point and concentration ratio and the temperature of outlet hot water or steam by using different receivers. The present work deals with a new system consists of dish and receiver to produce hot water and steam from solar energy. The parabolic dish solar collector fabricated from iron with different dimension the first model with diameter (82 cm) and depth (6 cm), this gives focus length (70cm) and Concentration ratio (25.6). The second model with a diameter (100cm) and depth (3 cm), this give focus length (208cm) and concentration ratio (15). The third model with a diameter&nbsp; (150cm) and depth (12cm), This give focus length (100cm) and concentration ratio (399) and the front side covered by nickel sheet metal to focus the solar radiation upon the receiver for all models&nbsp; . Three different shapes of receiver tanks used with the third model ; namely case one which used rectangular receiver tank (100×50×5) cm<sup>3</sup> filled with 25 liter of water. Case two used helical copper coil (12.5 mm× 3 m) inside aluminum cylindrical vessel (0.2 m ×0.6 m). Case three used radiator heat exchanger receiver tank (37×47×4) cm<sup>3</sup> filled with 3 liter of water. Use low cost and available materials to manufacture the experimental part. The dish, used as part of the solar reflector, covered by several strips of nickel sheet metal. When the parabolic dish collector was operational, the temperature of water was 60 <sup>o</sup>C in rectangular receiver tank, 75 <sup>0</sup>C within the copper coil and 125 <sup>o</sup>C in radiator device receiver. For rectangular receiver tank, hot water obtained within time (2 h), for copper coil receiver tank, hot water obtained within time (30 min) and for radiator heat exchanger receiver, steam obtained within time (20 min).</p> 2019-01-28T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1981 The Robust Stream Cipher for Securing Data in the Smartphones 2019-02-20T16:45:46+00:00 Abdullah S. Abid orjent_2007@yahoo.com Mohammed J. Zaiter mjzaiter@eetc.mtu.edu.iq Tayseer S. Atia tayseer_salman@yahoo.com <p style="text-align: justify;">With the development of network and communication systems in large areas in the world, this leads to increase security problems in transmission of data such as data leakage, modification, unauthorized access, and attacks. There are many types of techniques that are used to prevent these problems and protect data. One of these techniques is a stream cipher which considered the strongest and fastest method used in encryption and decryption process. In this study presented a new design for the stream cipher to protect mobile data. The strength of stream cipher depends on it is' key. There are several methods to generate key. We used three types of generator. Then, it used the combiner to convert them into a nonlinear Boolean function in order to make the generator key more secure. To implement a new generator key by using these three kinds, we used four LFSRs and one of NLFSRs or FCSRs to produce five variables Boolean function. These variables will be as an input to the combiner function. Finally, we tested the generator and submitted it to the randomness tests that is publicly available in the National Institute of Standards and Technology (NIST).</p> 2019-01-31T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1991 Experimental Study of Forced Convection Heat Transfer Porous Media inside a Rectangular Duct at Entrance Region 2019-02-12T03:18:28+00:00 Moayed R. Hasan alinajeh999@gmail.com Suhad A. Rasheed Sah_Jumaily66@yahoo.com Ali Najeh Mahdi alinajeh999@gmail.com <p class="MsoNormal" style="margin-bottom: 8.0pt; text-align: justify; text-indent: 1.0cm; line-height: normal; direction: ltr; unicode-bidi: embed;"><span style="font-size: 10.0pt; font-family: 'Times New Roman',serif; mso-ascii-theme-font: major-bidi; mso-hansi-theme-font: major-bidi; mso-bidi-theme-font: major-bidi; mso-bidi-language: AR-IQ;">This work presents experimental investigation of flow and heat transfer characteristics for entry length of turbulent flow in a rectangular duct fitted with porous media and air as the working fluid. Rectangular duct (300<span dir="RTL" lang="AR-IQ">×</span>30 mm) with a hydraulic diameter (54.54 mm) was subjected to constant heat flux from lower surface (</span><span style="font-size: 10.0pt; font-family: 'Times New Roman',serif; mso-ascii-theme-font: major-bidi; mso-hansi-theme-font: major-bidi; mso-bidi-theme-font: major-bidi; color: black;">1.5 ×10<sup>2</sup> –1.8 ×10<sup>2 </sup>w/m<sup>2</sup></span><span style="font-size: 10.0pt; font-family: 'Times New Roman',serif; mso-ascii-theme-font: major-bidi; mso-hansi-theme-font: major-bidi; mso-bidi-theme-font: major-bidi; mso-bidi-language: AR-IQ;">) and Reynolds number ranged (</span><span style="font-size: 10.0pt; font-family: 'Times New Roman',serif; mso-ascii-theme-font: major-bidi; mso-hansi-theme-font: major-bidi; mso-bidi-theme-font: major-bidi; color: black; mso-themecolor: text1;">3.3x10<sup>4</sup> up to 4.8x10<sup>4</sup></span><span style="font-size: 10.0pt; font-family: 'Times New Roman',serif; mso-ascii-theme-font: major-bidi; mso-hansi-theme-font: major-bidi; mso-bidi-theme-font: major-bidi; mso-bidi-language: AR-IQ;">). Copper mesh inserts (as porous media) with screen diameter (54.5 mm) for vary distance between two adjacent screens of (10 mm), (15 mm) and (20 mm) in the porosity range of (0.98 - 0.99) are considered for experimentation. The effect of porous height ratio (full and partial) are also considered. It is observed that the enhancement of heat transfer by using mesh inserts when compared to a plain surface is more by a factor of (2.2) times where the skin fraction coefficient is about (5) times. An Empirical correlation for Nusselt number and friction factor are developed for the mesh inserts from the obtained results.</span></p> 2019-02-11T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1992 Effect of Heat Treatment on Properties of Titanium Biomedical Alloy 2019-02-12T03:26:49+00:00 Jassim M. Salman Al-Murshdy jmsmaterials@yahoo.com Bassim Jaber Ghayyib bassimjaber888@gmail.com <p style="text-align: justify;">The aim of this work to study the effects of heat treatments on the alloy (Ti6Al4V) which produced by powder metallurgy methods and consists of a mixture of the following powders (titanium 90%, aluminum 6%&nbsp; and vanadium 4%).The heat treatments (sintering process) take place in different time of stay. The alloy (Ti6Al4V) used as biomaterials in the medical field due to their&nbsp; excellent properties such as : high corrosion resistance, high wear resistance, high breaking strength, higher ductility, non-toxic and non-magnetic, suitable elasticity coefficient, where&nbsp; used as&nbsp; an alternative to replacing damaged hard tissues such&nbsp; as&nbsp; orthopaedic, osteosynthesis, full hip joint, knee joint and dental implants. The elements were weighed by a highly sensitive electronic balance, the powder was mixed for five hours, Then press with a pressure (700 MPa) to transition to green cylindrical samples with a diameter of 13 mm. The sintering process was carried out at 1100 °C. The porosity of the samples decreases at high temperatures and time of stay to a certain extent and then increase porosity at very high temperatures due to the growth of particle and the expansion of gases. The density of the samples after the sintering process increases with increasing the temperature because increase the mass diffusion of particles and reduces porosities that increase contact points between particles. The sintering processes lead to increase the hardness, where the hardness was tested in the Vickers hardness method. The wear increased by increasing (load, time and sliding distance), and increase the hardness leads to a low volume loss (the amount of metal lost a few) as the relationship between them is inverse. To study the corrosion behavior of the samples that have been sintering processes under different time of stay and to perform this test (tafel Extrapolation test) in 0.9 NaCl solution, where the sample is subjected to high temperature and a long period of stay and therefore This lead to increases the diffusion and increases the contact points between the particles and increase the forces of bonds between the particles and this leads to increased corrosion current and therefore the oxidation process to be a high degree and this leads to the higher rate of corrosion.</p> 2019-02-11T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1993 Experimental Investigation of Using PET Wastes as Tension Bars in Reinforced Concrete Beams 2019-02-12T03:37:20+00:00 Abass Oda Dawood abbasoda03@uomisan.edu.iq Hamsa Mahir Adnan hamsamahir95@gmail.com <p style="text-align: justify;">This research is aimed to study the possibility of recycled the PET wastes by forming the PET wastes as plastic semi-bars and used it as tension bars in simply supported reinforced concrete beams . Twelve beams specimens with dimension of (150*200*1400) mm are casted and tested to monitoring the effecting of these wastes as tension bars on the strengths and serviceability of reinforced concrete beams. The mechanical properties (compressive, splitting tensile and flexural strength) are evaluated in which specimens tested in age of 28 days. The tests results showed that all presented plastic semi-bars are failed except one case in which the deformed steel bar are used with additional layer of PET bottle cut into two parts which showed an increment in ultimate failure load and deflection of&nbsp; 3.03 % and 213.83 % respectively, larger than the reference beam specimens. Negatively effect of PET semi-bar on ultimate load of beams is due to bonding failure between PET bars and surrounding concrete, which made the PET bars as voids or weak region within beam cross section.</p> 2019-02-11T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1995 A Comprehensive Review on Various Estimation Techniques for Multi Input Multi Output Channel 2019-02-12T03:52:59+00:00 Awwab Qasim Jumaah Althahab eng.awwab.qasim@uobabylon.edu.iq Sameer Abdul Kadhim Alrufaiaat samirabdcathem@yahoo.com <p style="text-align: justify;">The problem of wireless channel estimation has been evolving due to some undesirable effects of channel physical properties on transmitted signals. At the receiver end, distortions, delays, attenuations, interferences, and phase shifts are the most issues encounter together with the received signals. In order to overcome channel effects and provide almost a perfect quality of data transmission, channel parameter estimation is needed. In Multiple Input-Multiple Output systems (MIMO), channel estimation is a more complicated step as compared with the Single Input-Single Output systems, SISO, because of the fact that the number of sub-channels that needs estimate is much greater than SISO systems. The fundamental objective of this research paper is to go over the famous and efficient algorithms that have been innovated to solve the problem of MIMO channel estimation in wireless communication systems. In this paper, these techniques have been classified into three groups: non-blind, semi-blind and blind estimation. For each group, a brief illustration is presented for familiar estimation algorithms. Finally, we compare between these techniques based on computational complexity, latency and estimation accuracy.</p> 2019-02-11T00:00:00+00:00 ##submission.copyrightStatement## https://journalofbabylon.com/index.php/JUBES/article/view/1996 Identity and Exchangeable of Figure and Background Visually 2019-02-12T04:06:00+00:00 Basim Hasan Hashim Al-Majidi 90004@uotechnology.edu.iq Ahmed Hashim El-Eqapy 90047@uotechnology.edu.iq <p style="text-align: justify;">Studies has focused generally on studying generally and specific researches concepts in architecture, one of these concepts was the identity and the ways that support constructing and specifying the identity concept with in various frames , but it ignore important side which represented by experimenting two points which they are the figure and background visually and the exchangeable connection and the effect of each one of them on the other in forming the general frames to identity in sight of architectural knowledge frame around all identity and its relationships with figure and background visually.</p> <p style="text-align: justify;">&nbsp;This paper aims to define the general visions to study the identity concept in general and the effect of figure and background visually and the exchangeable effect between them in constructing the basis of this new identity by specifying the knowledge proposition about the general subject then build a theoretical frame for these concepts and apply it on specific architectural case study representing a practical example of the identity concept in architecture and analyzing the results of about there are approximate in nature and level of results of figure and background visually and its relationship exchangeable with identity.</p> 2019-02-11T00:00:00+00:00 ##submission.copyrightStatement##