Globally, the focus is on maximizing the energy yield and efficiency of PV systems as an essential renewable energy source. Different methods have been proposed to achieve this goal. Where the sun’s location in the sky is changed during the day, a tracking mechanism has been proposed as a promising technology to harness the maximum amount of solar radiation by PV system as compared to the fixed panels. In this study, the design and implementation of a polar single-axis tracking system is presented to improve the energy efficiency of PV system through angular variation during the day using the proposed tracking system. This is achieved by interconnecting some devices that include GPS sensors and satellite dish actuators
... Show MoreA compact microstrip six-port reflectometer (SPR) with extended bandwidth is proposed in this paper. The design is based on using 16-dB multi-section coupled line directional couplers and a multi-section 3-dB Wilkinson power divider operating from 1 to 6 GHz. The proposed SPR employs only two calibration standards: a matched load and an open load. As compared to other dielectric substrates, fabricating the proposed SPR involves using a low-cost (FR4) substrate. A novel algorithm is also proposed to estimate the complex reflection coefficient over the frequency ranges at which the standard performance of the circuit components is not fully satisfied. The new algorithm is based on the circles’ intersection points, which
... Show MoreShell-and-double concentric tube heat exchanger is one of the new designs that enhance the heat transfer process. Entransy dissipation is a recent development that incorporates thermodynamics in the design and optimization of heat exchangers. In this paper the concept of entransy dissipation is related to the shell-and-double concentric tube heat exchanger for the first time, where the experiments were conducted using hot oil with temperature of 80, 100 and 120°C, flow rate of cold water was 0.667, 1, and 1.334 kg/m3 respectively and the temperature of inlet cold water was 20°C. The entransy dissipation rate due to heat transfer and to fluid friction or pressure drop was studied.
The influence and hazard of fire flame are one of the most important parameters that affecting the durability and strength of structural members. This research studied the influence of fire flame on the behavior of reinforced concrete beams affected by repeated load. Nine self- compacted reinforced concrete beams were castellated, all have the same geometric layout (0.15x0.15x1.00) m, reinforcement details and compressive strength (50 Mpa).
To estimate the effect of fire flame disaster, four temperatures were adopted (200, 300, 400 and 500) oC and two method of cooling were used (graduated and sudden). In the first cooling method, graduated, the tested beams were leaved to cool in air while in the seco
... Show MoreReverse osmosis technique was used for the treatment of industrial waste water. Ions like calcium, magnesium, sodium, sulfate, and nitrate were found in the waste water of the General Company of Vegetable Oil with high concentrations which must be treated for reuse. Feed water containing the above mentioned ions was fed to the RO unit at feed flow rates (0.4 and 0.8 lit/min) and different operating pressure (2-4bar) .It is concluded that increasing operating pressure and feed flow rate improved the separation by a decrease in the concentration of ions in the product. High rejection was obtained for all ions present in feed water, ranging from (63.8-97.6%). Rejection of TDS was 87% when the concentration of TDS was reduced from 1192 to 15
... Show MoreA numerical technique is developed to predict both the transient and steady axisymmetric two-dimensional natural convection heat transfer for water as the working fluid in a vertical annulus enclosure of a fixed radius ratio (2) aspect ratio (1) and Rayleigh number ranging within (103 ≤Rad≤106) for a fixed Prandtl number (Pr=7). Finite difference analogs of the Navier – Stokes and thermal energy equations are solved in the stream function – vorticity frame work. The results obtained are
presented graphically in the form of streamline, vorticity and isotherm contour plots. A correlation has been set up to give the average Nusselt number variation with Rad and for which the results are found to be in good agreement with previo
Construction projects contain many problems that can occur during the execution. Each problem results from many causes. Fault tree analysis (FTA) technique is a graphical model for analyzing causes of a problem (or undesired event) using logic gates to describe combinations of individual faults that can create an undesired event. Each level of the tree lists the lower level events that are necessary to cause the event shown in the level above it. The assessment process of a problem with FTA technique can be divided into two types: qualitative and quantitative assessment. As a case study to apply FTA technique in construction field, the researcher studied a building in Baghdad that had punching shear problem to analyze the causes lead to
... Show MoreMany researches assigned the importents of enhance the architectural education movement. It is obvious that these studies have elaborated in their interest in architectural curriculum and teaching methodm in addition to the important of qualifying the staff to cover these changes. Most of these studies couldn't define a specific solutions to improve teachers method to lead the digital education According to this the research problem was defined as: "There is no comprehensive study clear the real attitude of the architectural teachers in Iraqi schools of architecture from the digital teaching…within the vocabulary of (digital knowledge– desire for more information about digital knowledge - the attitude of digitalizing architectural cu
... Show MoreThe present study aims to evaluate the biosorption of reactive orange dye by using garden grass. Experiments were carried out in a batch reactor to obtain equilibrium and thermodynamic data. Experimental parameters affecting the biosorption process such as pH, shaking time, initial dye concentrations, and temperature were thoroughly examined. The optimum pH for removal was found to be 4. Fourier transform infrared spectroscopy analysis indicated that the electronegative groups on the surface of garden grass were the major groups responsible for the biosorption process. Four sorption isotherm models were employed to analyze the experimental data of which Temkin and Pyzhey model was found to be most suitable one. The maxim
... Show MoreSpace Time Trellis Code (STTC) is a technique that can be used to improve the performance of
the Orthogonal Frequency Division Multiplexing (OFDM) system over wireless channels by
providing both coding gain and diversity gain. STTC is combined from two codes, Trellis Code
Modulation (TCM) as an inner code and Space Time Block Code (STBC) as an outer code. TCM
which combines the choice of a modulation scheme with that of a convolutional code provides the
coding gain, and the other code provides the diversity gain. Simulation is done over flat fading and
frequency selective Rayleigh fading channel for Eight Phase Shift Keying (8-PSK) TCM. It found
that the best results are obtained for the case of two tra
A Genetic Algorithm optimization model is used in this study to find the optimum flow values of the Tigris river branches near Ammara city, which their water is to be used for central marshes restoration after mixing in Maissan River. These tributaries are Al-Areed, AlBittera and Al-Majar Al-Kabeer Rivers. The aim of this model is to enhance the water quality in Maissan River, hence provide acceptable water quality for marsh restoration. The model is applied for different water quality change scenarios ,i.e. , 10%,20% increase in EC,TDS and BOD. The model output are the optimum flow values for the three rivers while, the input data are monthly flows(1994-2011),monthly water requirements and water quality parameters (EC, TDS, BOD, DO and
... Show MoreA winglet is devices attached at the wing tips, used to improve aircraft wing efficiency by reduction influence wing tips vortices and induct drag, increasing lift force at the wing tips and effective aspect ratio without adding greatly to the structural stress and weight in the wing structure. This paper is presented three-dimensional numerical analysis to proposed modification swept back wing by adding Raked winglets devices at the main wing tips belong the two seat trainer aircraft type Aermacchi Siai S211 by using Fluent ANSYS 13 software. CFD numerical analysis process was performed at the same flight boundary conditions indifferent wing angle of attacks with constant air flow velocity V∞ =50 (m/sec), ambient pressure Po=101325 (P
... Show MoreThis research of using Feldspar in the production self compacting concrete (SCC) ( 5,10,15 )% as partial replacement by weight of cement .In this research some of fresh properties of SCC ( slump flow used V-funnel test and filling ability used ( U- box test ) for concrete mixes and also some of the harden properties of SCC ( compressive and flexural tests ). The research results showed that negative effect of Feldspar on the fresh properties of self compacting concrete but the positive effect of Feldspar on the harden properties of self compacting concrete .
Soil movement resulting due unsupported excavation nearby axially loaded piles imposes significant structural troubles on geotechnical engineers especially for piles that are not designed to account for loss of lateral confinement. In this study the field excavation works of 7.0 m deep open tunnel was continuously followed up by the authors. The work is related to the project of developing the Army canal in the east of Baghdad city in Iraq. A number of selected points around the field excavation are installed on the ground surface at different horizontal distance. The elevation and coordinates of points are recorded during 23 days with excavation progress period. The field excavation process was numerically simulated by using the finite
... Show MoreA theoretical investigation study was carried out to determine the requirements of establishing a steam power plant by incinerating municipal solid wastes generated from the city of Baghdad. Survey data the generated quantities of municipal solid wastes from both Al-Karth and Al-Rusafa sectors of the city were utilized to predict the theoretical possible energy production that can be obtained from the incineration of this waste under controlled parameters. Results reviled that the high heating value of Baghdad’s municipal solid wastes is of about (12.789 MJ/kg) and the possible electrical energy production in the steam power plants in Al-Karth and Al-Rusafa are (119.287 MW, 203.917 MW) respectively using a steam turbin
... Show MoreThis study aims to find the effect of water-cement ratio on the compressive strength of concrete by using ultrasonic pulse velocity test (UPVT). Over 230 standard cube specimens were used in this study, with dimensions of 150mm, and concrete cubes were cured in water at 20 °C. Also, the specimens used in the study were made of concrete with varied water-cement ratio contents from 0.48 to 0.59. The specimens were taken from Diyarbakir-Turkey concrete centers and tested at the structure and material science lab, civil engineering, faculty of engineering from Dicle University. The UPV measurement and compressive strength tests were carried out at the concrete age of 28 days. Their UPV and compressive strength ranged
... Show MoreThis paper attempted to study the effect of cutting parameters (spindle speed and feed rate) on delamination phenomena during the drilling glass-polyester composites. Drilling process was done by CNC machine with 10 mm diameter of high-speed steel (HSS) drill bit. Taguchi technique with L16 orthogonal layout was used to analyze the effective parameters on delamination factor. The optimal experiment was no. 13 with spindle speed 1273 rpm and feed 0.05 mm/rev with minimum delamination factor 1.28. &
... Show MoreOptimal design of three links and four links serial manipulator involves striking a balance between an
appropriate link length, radius, link exact end effecter deflection and the amount of stress induced in each
link. Optimization has been applied for getting a minimum robot weight through making the robot arm
section tapered while keeping the first link as cylindrical tube as it represent the robot base only. The
synthesis optimization problem involves setting up guess values for links length and radius subjected to
constraints of deflection, stress and geometric constraints of total robot length. The optimization process
focuses on minimization of robot weight as an objective function, the guess values has taken from
Adsorption capacity of a waste biomass, date stones, for phenolic compounds such as phenol (Ph) and p-nitro phenol (PNPh) was investigated. The characteristics of such waste biomass were determined and found to have a surface area and iodine number of 495.71 m²/g and 475.88 mg/g, respectively. The effects of temperature, initial sorbate concentration, and contact time on the adsorption process were studied. Experimental equilibrium data for adsorption of Ph and PNPh on date stones were analyzed by the Langmuir, Freundlich and Sips isotherm models. The results show that the best fit was achieved with the Sips isotherm equation with maximum adsorption capacities of 147.09 and 179.62 mg/g for Ph and PNPh, respectively. The kinetic data wer
... Show MoreThe present paper is an experimental study to improve the productivity of the conventional solar still. This done by modifying conventional still in a way that the distilled basin is larger than distillation basin, thus providing an increase in the condensation surface and speeding up the condensation process. Moreover, increase in the dimensions of the distilled base helps coupling reflective panels to the distilled base to reflect incident solar radiation to the distillation basin. For this purpose , two solar stills were made, one conventional designand another made according to the proposed design. The two solar stills were tested during the period from February to July 2009 under varying weather conditions of Basra, Iraq (latitude o
... Show MoreHousing planning is one of the most important subjects in the housing sector studies. It
is wide and has many branches . .
Housing planning according to the cost and social benefit is the solution to prevent the
escalating rise in Housing shortage .
This fact is combined with which is estimated at more than three million housing unit .
And big a reduction in housing construction rate , which lead to increase the housing problem
in the country. This matter needs a clear policy from the authorities to accelerate the planning
process and to adopt that strategy to solve the housing problem in Iraq.
This strategy should adopt the principal of constructing low – cost housing complexes
through the
Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multi-carrier technique.The core operation in the OFDM systems is the FFT/IFFT unit that requires a large amount of hardware resources and processing delay. The developments in implementation techniques likes Field Programmable Gate Array (FPGA) technologies have made OFDM a feasible option. The goal of this paper is to design and implement an OFDM transmitter based on Altera FPGA using Quartus software. The proposed transmitter is carried out to simplify the Fourier transform calculation by using decoder instead of multipliers. After programming ALTERA DE2 FPGA kit with implemented project, several practical tests have been done starting from monitoring all the results of
... Show MoreIn most of the construction projects, there are many events or risks may occur during the execution
of project. These risks (e.g. the excess of project cost or the expected time, increasing the prices of
material and labor, accidents, changes, engineering errors or omissions, bad quality, delay in
reaching the facilities to the site, etc.) may effect negatively on the project and the parties.
Therefore, these risks must be identified and assessed accurately to avoid or reduce the negative
effects for these risks. The concept of risk is used to assess and evaluate uncertainties associated
with an event or a process. A construction process includes many uncertainties, therefore, the
construction project’s parties are
Total quality management considers one of the modern scientific entrances which practiced by productivity service organizations alike to provide appropriate quality required outputs according to the needs and desires of customers manage , enable the organization seeking to continue and grow in light of the increasing competition from the satisfy and provide the appropriate total quality management requirements whenever led to face risks that they may have in a manner in which they can be addressed and find ways to avoid them in the future when repeated. &n
... Show MoreThis paper deals with the using of Geographic Information Systems to build up analytical model to choose the best locations of new schools within the study area. This has been done by using satellite image of Baghdad city. Then multi themes digital maps were prepared to the study area. These can be used to update their data by using Geographic Information Systems software. Then, an analytical had been prepared to create the best probable locations, for new primary schools, depending on criteria, scientific technical specifications. Finally, we prepared layouts with geographical geometrical specifications for these proposed locations.
Buildings such as malls, offices, airports and hospitals nowadays have become very complicated which increases the need for a solution that helps people to find their locations in these buildings. GPS or cell signals are commonly used for positioning in an outdoor environment and are not accurate in indoor environment. Smartphones are becoming a common presence in our daily life, also the existing infrastructure, the Wi-Fi access points, which is commonly available in most buildings, has motivated this work to build hybrid mechanism that combines the APs fingerprint together with smartphone barometer sensor readings, to accurately determine the user position inside building floor relative to well-known lan
... Show MorePorous asphalt paving is a modern design method that differs from the usual asphalt pavements' traditional designs. The difference is that the design structure of porous pavements allows the free passage of fluids through their layers, which controls or reduces the amount of runoff or water accumulated in the area by allowing the flow of rain and surface runoff. The cross-structure of this type of paving works as a suitable method for managing rainwater and representing groundwater recharge. The overall benefits of porous asphalt pavements include environmental services and safety features, including controlling the build-up of contaminated metals on the road surface, rainwater management, resistance to slipping ac
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Asphalt Hot Mix (HMA) is mainly applied in highway construction in Iraq because of its economic advantage and easy maintenance. Various factors impact the performance of HMA in the field. It is one of the significant impacts on aggregate gradation. The Universal Specification for Roads and Bridges in Iraq (SCRB) limits the different types of asphalt layers and allows for designed tolerance aggregate gradation. It is quite hard for contractors in the present asphalt industries to achieve the required job mix because of sieves' control problems. This study focuses on the effects on the required specification performance of aggregate deviations by using original and modified asphalt binder with AC(40-50) and
... Show MoreA study on the treatment and reuse of oily wastewater generated from the process of fuel oil treatment of gas turbine power plant was performed. The feasibility of using hollow fiber ultrafiltration (UF) membrane and reverse osmosis (RO) membrane type polyamide thin-film composite in a pilot plant was investigated. Three different variables: pressure (0.5, 1, 1.5 and 2 bars), oil content (10, 20, 30 and 40 ppm), and temperature (15, 20, 30 and 40 ᵒC) were employed in the UF process while TDS was kept constant at 150 ppm. Four different variables: pressure (5, 6, 7 and 8 bar), oil content (2.5, 5, 7.5 and 10 ppm), total dissolved solids (TDS) (100, 200,300 and 400 ppm), and temperature (15, 20, 30 and 40 ᵒC) were mani
... Show MoreNo-fines Concrete is a lightweight porous concrete produced by omitting sand from the traditional concrete mix. It helps replenish the groundwater aquifer by directly allowing precipitation to seep into the earth thanks to its wide pores. This work studied the influence of partially replacing cement with silica fume (SF) with percentages of 5, 8, and 10% on some properties of no-fine concrete made using recycled coarse aggregate. The natural coarse aggregate (NA) was replaced with 10%, 20%, and 30% by crushed reactive powder concrete waste volume as recycled aggregate (RA). The optimum percentage was 10% RA with 10% SF, which indicated a substantial improvement in the no-fine concrete's strength, dry density, and water a
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