About Journal

Engineering and Technology Journal is a global, scientific and Open Access journal. Publishing under the license of Creative Commons Attribution 4.0 International (CC-BY), this journal is published monthly by the University of Technology (UOT), Iraq, since 1977 (printed version) and since 2005 (online version). ETJ publishes original articles and review papers in the fields of engineering and science. The journal is using a double-blind peer-reviewing system to assure the quality of the publication. The iThenticate service is used to prevent plagiarism and to ensure...
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Journal Information

Publisher: University of Technology-Iraq

Email:  [email protected]

Editor-in-chief: Prof. Dr. Qusay F. Alsalhy

Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 34 (2016)
Volume 31 (2013)
Volume 28 (2010)
Hot Spot Analysis of Photovoltaic Module under Partial Shading Conditions by Using IR-Imaging Technology

Ali. H. Numan; Hashim A. Hussein; Zahraa S. Dawood

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1338-1344
DOI: 10.30684/etj.v39i9.841

The probable appearance of localized overheating (hot spot) represents one of the main matters for the reliability and safety of c-Si cells. It entails both a risk for the photovoltaic module's lifetime and a decrease in its operational efficiency. Partial shading is the most common cause of a hot spot in a PV system. The main aim of this work is to analyze the hotspot phenomena by I-V curve as well as IR thermography and investigate the impact of partial shading on the hottest cell experimentally to find its effect on the output power. The results show that at normal operating conditions (G=865W/m2 and Ta=39.7°C) the output power is 89.05W; the temperature difference between the hottest and cooled cell was about 6°C. Moreover, the short circuit current and consequently, the maximum output power reduced if only one cell fully or partially shaded. However, when the hottest cell is shaded by 25%, 50%, 75%, and 100% of the shaded area, the power losses were 37.17 %, 50.05%, 48.61%, and 52.86% respectively. Wheals, the hottest cell temperature was 80.6, 99.1, 101.4, and 62.4°C for 25, 50, 75, and 100% of the shading area, the major temperature difference observed at 75% of the shading area.

The Influence of Ultrasonic Impact Peening on the Mechanical Properties of Similar Friction Stir Welded Joints of AA 7075-T73

Abdul Ameer H. Jebur; Samir A. Amin; Ibtihal A. Mahmood

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1345-1351
DOI: 10.30684/etj.v39i9.1725

The purpose of this study is to study the ultrasonic peening influence upon the mechanical properties of the welded joints of 3 mm AA 7075-T73. Friction stir welding (FSW) was carried out by using milling machine and cylindrical tool with tapered pin. The used welding parameters were 710 rpm , 35 mm min for rotational and travel speed , respectively .Tensile tests results showed that the welding efficiency was about 60% for welded samples , and this value increased by using one and two lines ultrasonic peening treatment to 74% , and 71% , respectively , this improvement is due to generating compressive stresses along the surface of welded joints. The microhardness of the welded samples showed that there were fluctuations across the welded centerline and minimum hardness occur in the heat affected zone (HAZ).

Optimum Parameter Selection for Milling Different Laminate Composites Made by Hand Layup with CNC Milling Machine

Ghadak M. Alkhafaji; Fathi A. Alshamma; Enas A. Khalid

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1352-1361
DOI: 10.30684/etj.v39i9.1737

Recently, composite materials were widely used in different applications due to their lightweight, and good thermal and mechanical properties. In this study, an attempt to manufacture laminate composites by hand layup was performed. Also, optimal parameters for the best surface roughness were investigated. Therefore, three parameters had been examined; spindle speed, feed rate, and depth of cut. The L9 Taguchi orthogonal array, signal to noise (S/N) ratio, and analysis of variance (ANOVA) were selected to determine the optimum parameters. To create composites, the compression method was employed. Four different types of composites were manufactured with 2.8 mm thickness, to determine the effect of the parameters on the surface roughness and for specified parameters using the CNC milling machine. The weight fraction ratio of fibers was 39%, the polymer was 34%, and 27% for Aluminum. The results showed that the optimum parameters for surface roughness in milling machine of composites for Polyester resin for aluminum–fiberglass composite are; spindle speed=5000 r.p.m, feed rate=1600 mm/min, depth of cut=1.6 mm and Ra=1.853 μm, and for epoxy resin; aluminum–carbon fiber composite is spindle speed=4000 r.p.m, feed rate=800 mm/min, depth of cut=1.2 mm and Ra=2.43 μm.

Effect of Wavy Fins on Thermal Performance of Double Pass Solar Air Heater

Jalal M. Jalil; Rasha F. Nothim; Mustafa M. Hameed

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1362-1368
DOI: 10.30684/etj.v39i9.1775

In this paper, experimental study on double pass solar air heater with wavy fins absorber has been investigated. The fins attached to the upper and lower surfaces of the absorber. Two wavy fins arrangement (3 and 7 fins) have been investigated with plan absorber by changing solar radiation intensity (500, 600, 700 and 800 W/m2), air mass flow rate form 0.008575 kg/s to 0.0214375 kg/s. The results of wavy finned absorbers are compared with plane and the improving in thermal efficiency reached 80% and 84% in 3 and 7 wavy fins absorbers respectively.

Experimental Investigation of Dimensional Accuracy in Non-traditional Sheet Metal Spinning Process for Producing Rectangular Spun Part

ِِAmmar M. Saleh; Aseel H. Abd; Aqeel S. Bedan

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1369-1375
DOI: 10.30684/etj.v39i9.1974

The non-conventional spinning process was adopted for producing polygons, but one of the process limitations is the error between design and the final product especially with no-mandrel. Dimensional accuracy was adopted for this purpose which gives an indicator of the ability of the formed part to matches the design and checking validated of the adopted methodology for producing rectangular cross-section spun parts, by comparing the coordinating points of real part with the points of the design model. The point of a real part was measured by using a sphere probe fixed on the three-axis milling machine and capturing the data of machine axis movements for the center location of the probe, also, the measurements oppositely took place, by offsetting the points of design along the normal vector for comparison with the real part points. Three parameters were invested for study the effects on the dimensional accuracy, these parameters are spindle speed (48, 68, and 135 RPM), feed ratio (0.16, 0.22, and 0.32 mm/rev), and the ball diameter of the forming tool (16, 22 and 25 mm). The results show that tool ball diameter mainly affecting dimensional accuracy with a higher value of average error reach (6.47mm) when 16mm diameter of tool ball was used, on the other hand, the minimum average error was 1.705mm at low spindle speed.

An Experimental Investigation of The Dynamic Effects in Upper Drum Boiler Under Steam Mass Flow Rate Variation

Russul Mohammed; Hashim Hussein; Ali H. Numan

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1376-1383
DOI: 10.30684/etj.v39i9.1998

The dynamic effects in the “upper“ drum of the boiler (mechanical’s effects) are very complex problems and critical due to the pressure disturbance in the upper drum of the boiler. This work deals with an experimental investigation of the dynamic behavior of the boiler drum level system is reported from plant data (Al-Quds power plant) in Baghdad / Iraq under a particular condition of operating, and the mathematical equations of the boiler model variables explained and defined. The dynamic effects are investigated with increasing steam mass flow rate (10% and 20%) at the outlet of the boiler. The results showed that the rapid rise in the rate of steam mass flow causes the dynamic effects to increase (shrink and swell) by 15%, rates of evaporation and thus causes an increase in the volume of water inside the upper drum boiler that causes overheating in the tubes.

Enhanced Mechanical and Fatigue Properties In AA5052 Via TiO_2 Nanoparticles Addition Sintering Temperature (ST)

Zahraa J. Kadhim; Hussain J.M. Alalkawi; Ahmed H. Reja

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1384-1391
DOI: 10.30684/etj.v39i9.2020

The goal of the present work is to study the effect of different sintering temperatures (900, 1000 and 1100 ) on fatigue and mechanical characteristics of the metal matrix AA5052 reinforced with 5% of TiO2 nanoparticles. The stir casting process is used for manufacturing of AA5052/TiO2 nanocomposite. The mechanical characteristics of nano composites have been obtained at ambient temperature. The results of mechanical properties showed that the best enhancement in hardness (HB), ultimate tensile strength (UTS) and yield strength (YS) is occurred in nanocomposite with 1000  sintering temperature (ST). However, the fatigue test results showed that the samples manufactured under 1000  (ST) have longer fatigue life compared to other materials with different sintering temperatures. The endurance fatigue strength is improved by 7.2% compared to metal matrix. The experimental results showed that the microstructure image of 1000  (ST) composite has uniformly distributed of TiO2 in AA5052 matrix.

Electricity Generation from Hydro, Wind, Solar and the Environment

Olumide A. Towoju; Oluwatoyin A. Oladele

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1392-1398
DOI: 10.30684/etj.v39i9.2145

Human actions such as electricity generation are contributory causes of climate change. In a quest to reduce the emission of greenhouse gases associated with electricity generation from fossil fuels, the world is turning to renewables. Renewable sources, however, also do have an impact on the environment. Likewise, renewable electricity generation is also dependent on the climate. Hydro, Wind, and Solar are the popular renewable energy sources for the generation of electricity. This work reviews the impact of these renewables in electricity generation on the environment. It also considers the effect of climate change on its use. The construction of renewable electricity generating plants leads to habitat disruptions and can also cause fatalities. Climate change weighs an enormous impact on the performance of renewable electricity generating plants. The recent blackout experienced in Texas as a result of the cold weather is a good example. The end of extreme weather conditions is not yet, and the need to start preparing to prevent a blackout re-occurrence. A possible solution for sustainable renewable electricity generation in extreme weather conditions lies in synthetic fuel availability.

A Practical Study of The Thermal Performance of a Vacuum Tube For Solar Collector Using a Double -Sided Electronic Curtain With Nano-Fluid

Nagham A. Majeed; Khalid F. Sultan; Hosham S. Anead

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1399-1408
DOI: 10.30684/etj.v39i9.2029

In this research, a practical study and appraisal of the thermal performance for the solar collector with vacuum tube has conducted Two types of nanomaterials (aluminum and aluminum oxide) have added to distilled water with nanoparticles diameters of 30 nm and 50 nm respectively. The nanomaterials were used in three several concentrations and three several flow rates which used as a working fluid in evacuated tube solar collector (ETSC) in order to increase the efficiency and beneficial thermal gain. An electronic double-sided reflective and absorbent electronic curtain were added to enhance the performance and control the temperature of the nanoscale. A clear improvement in efficiency was observed when using the reflective curtain that helped to speed up the Nano fluid heating and controlling the required temperature.

The Influence of Convection Heat Transfers for Vertical Mini-Tubes Using Solvent Carbon Dioxide and Porous Media at Supercritical Pressure

Bilal J. Kkihlefa; Ameer A. Jaddoa; Ahmed H. Reja

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1409-1419
DOI: 10.30684/etj.v39i9.2068

Porous media and solvent CO2 at supercritical pressure were investigated experimentally to study the effect of convection heat transfer in vertical mini-tubes. Mini-tubes diameter (5 and 8 mm) with medium porosity of 0.5 are proposed in experimental investigation. Experimental conditions consisted of bulk fluid, wall temperatures ranged from 33 to 55 oC, and 8 to 10 MPa of pressure. Reynolds number, Mass flow rate, and heat flux were 1750 to 21000, 0.5 to 4.5 Kg/h, and 3.25×104 to 1.1×105 W/m2 respectively. Some chemical additives like Ethanol, Chloroform, Acetone, Dimethyl sulfoxide, and Methanol were considered. A special focus was dedicated to studying the influence of heat flux, inlet temperature, and mass flow rate at measured values of wall and fluid bulk temperatures, and coefficients of local heat transfer for mini-tubes and porous media. A higher effect was noticed on the convection heat transfer by buoyancy and properties of the thermophysical variable of solvent CO2 in mini-tube at vertical position. However, when these results were compared with the controls (empty tube) shoewn dramatically different results. Heat transfer coefficient was bigger about 4 times when using the porous media tube compared with the empty type in the case of using a 5% of acetone solvent.

Distinguish the Textures of Grasped Objects by Robotic Hand Using Artificial Neural-Network

Hassan D. Salman; Mohsin N. Hamzah; Sadeq H. Bakhy

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1420-1429
DOI: 10.30684/etj.v39i9.2072

The object identification properties with tactile sensing are valuable in  interaction with the environment for both humans and robots, and it is the core of sensing used for exploration and determining properties of objects that are inaccessible from visual perception. Object identification often involves with rigid mechanical grippers, tactile information and intelligent algorithms. This paper proposes a methodology for feature extraction techniques and discriminates objects for different softness using adaptive robotic grippers, which are equipped with force and angle sensors in each four fingers of an underactuated robot hand. Arduino microcontroller and the Matlab program are integrated to acquire sensor data and to control the gripping action. The neural-network method used as an intelligent classifier to distinguish between different object softness by using feature vector acquired from the force sensor measurements and actuator positions in time series response during the grasping process using only a single closure grasping. The proposed method efficiency was validated using experimental paradigms that involving three sets of model objects and everyday life objects with various shapes, stiffness, and sizes.

Numerical Analysis of Linear Elevator Structure Using Finite Element Method

Saba A. Othman; Jamal A.-K. Mohammed; Farag M. Mohammed

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1430-1436
DOI: 10.30684/etj.v39i9.2083

In this work, the structure of the linear elevator prototype had been investigated numerically using finite element method. The linear motor structure parameters analyzed using Maxwell ANSYS. The time-stepping method depending on Maxwell equations be applied for analyzing and optimizing the magnetic and force characteristics. While the elevator structure parameters were analyzed using ANSYS workbench based on the principle of virtual work. The frame considered as clamped- clamped beam, and the base of the car considered as thin plate with small deflection. The analysis done with maximum applied load of 360 N at 1.5 safety factor. The results show the distribution of the magnetic lines, the flux density values plus the leakage flux inside the slots. The maximum Von-Mises stress and the deformations of the frame and plate at maximum load are acceptable and present save design. In which the maximum deflection of the thin plate not exceed (thickness/5) at maximum design load.  

Experimental Study of Air Ejector Performance to Cool Agricultural Products

Hassan S. Jawad; Qusay J. Abdul Ghafoor

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1437-1444
DOI: 10.30684/etj.v39i9.2105

In this research, an ejector was designed and manufactured from brass metal as part of a cooling system to cool agricultural products, work of ejector is based on the Venturi principle. The primary fluid is air and steam of product is the secondary fluid, used the primary pressure (1, 8, 1) bar for the purpose of conducting the experiment. The ejector was manufactured from a number of interconnected parts to give the final shape. The performance of the ejector was analyzed theoretically, through operating of system evaporation of water take place in vessel  leads to cooling product at change operation condition and the examination, it was reached:
a- The cooling efficiency of the product increases by increasing the primary pressure.
b- The cooling efficiency of the product increases by decreasing the mass of the product.
c- The loss weight of the product increases by increasing the primary pressure.

Preparing Nanofluids (Al2O3) for Enhancement Performance of Photovoltaic

Mohammed Saadoon; Ibtisam A. Hasan; Mohammed J. Mohammed

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1445-1453
DOI: 10.30684/etj.v39i9.2110

Photovoltaic (PV) panels produce electrical energy comparable to the cumulative amount of PV radiation generated on surface of sun. The solar modules influence on temperature of PV panel and for work with its standard specifications in Iraqi environment can be used nanofluid for cooling PV and improve performance. The developed thermal model for proposed cooling method has shown on the way to be an efficient design tool that can help engineers to reduce the time and cost of experimental testing. The improvement in temperature reduction using direct flow technique at rear sides of PV panel achieved electrical and thermal performance enhancement. The enhancement of overall efficiency at 1 g of nanofluid  is  showed  15%  but in 1.5g  nanofluid is  18%. As well as the enhancement of thermal efficiency at 1 g and1.5g of nanofluid are showed 19% and 27% respectively. So in Electrical efficiency at 1 g of nanofluid is showed 11% and in 1.5g  nanofluid is  14%.The experimental results have shown that the utilization of nanofluid (Al2O3) as a result of its high thermal conductivity and tiny particle size. The coefficient of heat transfer and Nusselt number increasing with the increase of concentration of nanofluid, It can be concluded that has great impact, especially in Iraq condition where the temperature is normally high and can improve their performance and efficiency by adding nanofluid for cooling system.

Reducing Vibrations Generated in a Gas Turbine Model MS9001E Used in South Baghdad Power Plant Station by Improving the Design of Bearings with Damper

Alaa J. Abdulah; Muhannad Z. Khalifa; Abdul Jabbar O. Hanfesh

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1454-1462
DOI: 10.30684/etj.v39i9.2134

Gas turbines are engines an energy plant makes use of for generating the rotary motion to show power generators. The gas turbine is largely a combustion engine for changing natural gas or different liquid fuels to rotational mechanical energy. Often, the gas turbine generates excessive noise or vibrations. In this work, the problem of vibrations occurrence in the gas turbine model MS9001E used in the south Baghdad power station is solved. This is done by making a groove in the bearing pad to increase the oil flow, replacing the bearing type with a tilt-pad bearing type with damper. The finite element method was used in the analysis process by ANSYS program. The results showed a decrease in the values of vibration amplitude, total deformation, stress, and strain.

Improved Approach to Iris Normalization for iris Recognition System

Abdulamir Abdullah karim; Sarah jasim Mohammed

Engineering and Technology Journal, 2015, Volume 33, Issue 2, Pages 213-221

As a part of a growing information society, security and the authentication of individuals become nowadays more than ever an asset of great significance in almost every field.Iris recognition system provides identification and verification automatically of an individual based on characteristics and unique features in iris structure. Accurate iris recognition system based on iris segmentation method and how localized the inner and outer iris boundariesthat can be damaged by irrelevant parts such as eyelashes and eyelid, to achieve this aim, the proposed method applied canny edge detection then circle hough transformation on an eye image passed through preprocessing operations. The proposed iris normalization is done by using the important information that resulted from circle hough transformation such as center and radius of iris and center and radius of pupil to convert iris region in original image from the Cartesian coordinates (x,y) to the normalized polar coordinates (r,θ).The proposed approach tested conducted on the iris data set (CASIA v4.0- interval), and tested on (CASIA v1.0- interval) iris image database and the results indicated that proposed approach has 99.8% accuracy rate with (CASIA v4.0- interval),and has 100% accuracy rate with (CASIA v1.0- interval) .

Use of IT Photographic and GIS in the Analysis of Complex Intersection of University of Baghdad

O.Z. Jasim; N.M. Alhayani

Engineering and Technology Journal, 2017, Volume 35, Issue 0, Pages 64-74

When planning to do a port or a new road or when determine the turning traffic movements for any road,
we must know the traffic movement on the road to determine the distribution and direction of the turning
traffic, and we must know pedestrian traffic, parking and land uses adjacent because this will help to
forecasting the magnitude of the changes in the movement of turning traffic in the future, which helps to
determine the priorities of sustainable development required. The increasing population and the preparation
of private vehicles of the most important factors that have helped to increase traffic congestion and transport
problems and the growing proportion of traffic, causing accidents and pollution as well as large losses of
the national economy. Pushing to put these problems to be addressed to search for the best possible means
to be diagnosed and treated as soon as what can be achieved through the use of modern technology as a
way analytical. It is no doubt that a GIS is one of the most important of these methods adopted in the world
in support of the decision and personalized sites imbalance through adoption in identifying problems of
traffic intersections and traffic streams through them and their sizes especially in the intersections of the
main streets in large cities and neighboring land uses task scope regional service, such as universities and
ministries. It also we can take advantage of modern technology through the use of Photographic technique
and application of computer programs in the survey and analysis of turning traffic for these nodes to ease
the pressure on those whom in charge of research to get the data for the streams of traffic and employ this
technique along the style of GIS in the analysis and treatment, and this would save a lot of time, cost and
effort with more accurate data. In addition, that is what this research will try to focus it through analytical
situ study for the problem of the mother Baghdad university intersection in the city of Baghdad, with the
two methods of modern technology.

Human Thermal Comfort Evaluation in Open Spaces of Two Multi-Story Residential Complexes Having Different Design Settings, Duhok-Iraq

Turki Hasan Ali

Engineering and Technology Journal, 2016, Volume 34, Issue 8, Pages 1700-1715

To achieve a sustainable residential area, open spaces must promote comfort and invite people to stay outdoors and prolonging their stays, which will contribute to a more lively residential areas offering greater interaction between its inhabitants. Thermal comfort is an essential factor that should be considered in any urban design process, urban design characteristics of any project have a strong influence on human thermal comfort at outdoor spaces, like its spatial organization and landscape elements, the paper aims to assess the impact of spatial organization differentiation on thermal comfort of inhabitants in two different residential multi-story complexes in Duhok city. Thermal comfort for an urban context in hot and semi-dry climate zone based on the physiologically equivalent temperature (PET) index have been adopted and simulated by ENVI-met program, two simulations were conducted for each complex through climatic data of the hottest day in summer and coldest day in winter of 2013. The results reveal that the two complexes have not provided a comfortable space during the two seasons in general, but it showed that the second complex has a better performance in this respect for the two seasons, in spite of the poor landscaping it has, the paper concludes the importance of the urban design characteristics represented by the spatial organization on thermal comfort of the inhabitants at open spaces at such kind of projects and climate, and the necessity of adopting more compact and close spaces.

Cathodic Protection of Steel Reinforcement in Concrete

Engineering and Technology Journal, 2008, Volume 26, Issue 3, Pages 131-142

The present research has be investigated the relation between the induced
level of polarization and the area of the embedded steel, area of the anode, the
concrete resistance and the level of applied external voltage. During exposure
period, the specimens were polarized using three different levels of external
voltages (750, 1000, 1500) mV. Various electrochemical and electrical
measurements were made, these include half cell potential, degree of polarization,
flowing current and the actually applied voltage as compared with the external one.
The results indicate differential moisture content in each specimen has
produced different potentials along the steel bars. Greater polarization has always
been associated with the submerged portion of the specimen where the concrete
resistance is at its minimum. whereas the degree of polarization is directly
proportional to the level of external voltage. The results also illustrate that, for a
given level of externally applied voltage, the degree of polarization is dependent on
the area of protected steel and the area of the anode. Thus the polarization increases with the decrease in the protected steel area and the increase of the area
of the anode.

The Effects of Different Environmental Conditions on the Characteristics of Fiber Reinforced Plates

Ghydaa K. Yass; Safaa H. Abdul Rahman

Engineering and Technology Journal, 2010, Volume 28, Issue 11, Pages 2259-2275

The failure of polymer matrix composite upon exposure to the environment
conditions has been assessed in the present study. Glass fabrics and unsaturated
polyester resin were selected to fabricate 8-layer laminates cross ply [(0/90)8]
arranged in symmetric and antisymmetric stacking sequence. Environmental
conditioning using Sea and Tap water with humidity exposure and Ultraviolet
radiation was conducted to investigate the vibrations characteristics of symmetric
and antisymmetric composite samples. After exposure time to the conditions
above for 500, 1000 and 2000 hr, laminates were subjected to three point bending
testing, in order to study their flexural properties (stiffness and strength) before
and after these exposures. Then a finite element analysis using the package
program ANSYS (version 10) was used for the analysis of free vibration
characteristics. The object was to obtain the natural frequency for each case of
environmental conditions at different exposure times. The results showed that
natural frequencies of cantilever laminate plates decreased with the increased
exposure time for the different environmental conditions.

Cathodic Protection of Steel Reinforcement in Concrete

Engineering and Technology Journal, 2008, Volume 26, Issue 3, Pages 131-142

The present research has be investigated the relation between the induced
level of polarization and the area of the embedded steel, area of the anode, the
concrete resistance and the level of applied external voltage. During exposure
period, the specimens were polarized using three different levels of external
voltages (750, 1000, 1500) mV. Various electrochemical and electrical
measurements were made, these include half cell potential, degree of polarization,
flowing current and the actually applied voltage as compared with the external one.
The results indicate differential moisture content in each specimen has
produced different potentials along the steel bars. Greater polarization has always
been associated with the submerged portion of the specimen where the concrete
resistance is at its minimum. whereas the degree of polarization is directly
proportional to the level of external voltage. The results also illustrate that, for a
given level of externally applied voltage, the degree of polarization is dependent on
the area of protected steel and the area of the anode. Thus the polarization increases with the decrease in the protected steel area and the increase of the area
of the anode.

The Effects of Different Environmental Conditions on the Characteristics of Fiber Reinforced Plates

Ghydaa K. Yass; Safaa H. Abdul Rahman

Engineering and Technology Journal, 2010, Volume 28, Issue 11, Pages 2259-2275

The failure of polymer matrix composite upon exposure to the environment
conditions has been assessed in the present study. Glass fabrics and unsaturated
polyester resin were selected to fabricate 8-layer laminates cross ply [(0/90)8]
arranged in symmetric and antisymmetric stacking sequence. Environmental
conditioning using Sea and Tap water with humidity exposure and Ultraviolet
radiation was conducted to investigate the vibrations characteristics of symmetric
and antisymmetric composite samples. After exposure time to the conditions
above for 500, 1000 and 2000 hr, laminates were subjected to three point bending
testing, in order to study their flexural properties (stiffness and strength) before
and after these exposures. Then a finite element analysis using the package
program ANSYS (version 10) was used for the analysis of free vibration
characteristics. The object was to obtain the natural frequency for each case of
environmental conditions at different exposure times. The results showed that
natural frequencies of cantilever laminate plates decreased with the increased
exposure time for the different environmental conditions.

Effect of Halogen Ions on The Corrosion of Brass In Na2SO4 Solution

Rana A. Majed; Saad M. Elia; Zahra; a Fadhel

Engineering and Technology Journal, 2010, Volume 28, Issue 7, Pages 1386-1395

This research involves study effect of halogen ions presence in 0.2M sodium
sulphate on the corrosion of brass at room temperature (30oC). Three concentration of
halogen ions (Fˉ, Clˉ, Brˉ, and Iˉ) were used 0.1, 0.2, and 0.3 M. The different in
corrosion parameters before and after added the halogen ions interpreted and
discussed which involves corrosion potentials (Ecorr), corrosion current densities
(icorr), and Tafel slops (bc & ba) in addition to discuss the polarization curves.
Polarization resistances (Rp) and the change in free energy (ΔG) were
calculated and interpreted, in addition to calculate the rate of corrosion (Rmpy).
The results of this work indicates that the presence of halogen ions in
experimental solution increases the rate of corrosion, and the effect of halogen ions
follows the sequence to increase the corrosion Iˉ > Clˉ > Fˉ > Brˉ.

Use of IT Photographic and GIS in the Analysis of Complex Intersection of University of Baghdad

O.Z. Jasim; N.M. Alhayani

Engineering and Technology Journal, 2017, Volume 35, Issue 0, Pages 64-74

When planning to do a port or a new road or when determine the turning traffic movements for any road,
we must know the traffic movement on the road to determine the distribution and direction of the turning
traffic, and we must know pedestrian traffic, parking and land uses adjacent because this will help to
forecasting the magnitude of the changes in the movement of turning traffic in the future, which helps to
determine the priorities of sustainable development required. The increasing population and the preparation
of private vehicles of the most important factors that have helped to increase traffic congestion and transport
problems and the growing proportion of traffic, causing accidents and pollution as well as large losses of
the national economy. Pushing to put these problems to be addressed to search for the best possible means
to be diagnosed and treated as soon as what can be achieved through the use of modern technology as a
way analytical. It is no doubt that a GIS is one of the most important of these methods adopted in the world
in support of the decision and personalized sites imbalance through adoption in identifying problems of
traffic intersections and traffic streams through them and their sizes especially in the intersections of the
main streets in large cities and neighboring land uses task scope regional service, such as universities and
ministries. It also we can take advantage of modern technology through the use of Photographic technique
and application of computer programs in the survey and analysis of turning traffic for these nodes to ease
the pressure on those whom in charge of research to get the data for the streams of traffic and employ this
technique along the style of GIS in the analysis and treatment, and this would save a lot of time, cost and
effort with more accurate data. In addition, that is what this research will try to focus it through analytical
situ study for the problem of the mother Baghdad university intersection in the city of Baghdad, with the
two methods of modern technology.

Measurement of Frequency Deviation By Using Arduino Uno

Widad Jasim Hamody; Nadheerah Haseeb Tawfeeq

Engineering and Technology Journal, 2015, Volume 33, Issue 4, Pages 947-959

This studyaims at constructing and implementinga new technique for calculating and correcting the frequency deviation in power systems. Several techniques were used to measure frequency deviation. One of them was Arduino Uno card which uses microcontroller ATmega328. This microcontroller board is an easy to use,accurate, economic and flexible solution for measurement problems.
The main objective of the work was to measure frequency deviation by microcontroller and displays it on (PC) monitor or small liquid crystal display (LCD) or both. Also, to correct the error if occurred by moving stepper motor with accurate steps which control the fuel gate in the generator, by reading the frequency at periodical time such as per 0.3 second and check the changes, if the frequency is more than required value. The controller and its suggested program (code) in C language will move the stepper motor clockwise (CW) until frequency reaches the required frequency (F0),i.e.50.00 HZ, if the reading gets lower than (F0), and the stepper motor will move counter clockwise (CCW) to get the required frequency. The system is applied practically by implementing the suggested design. This search achieved established control frequency of 99% along any variations in loads with high frequency reaches an accuracy 0.01HZ with low cost components.

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