Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 38, 3A

Volume 38, 3A, March 2020, Page 288-477


Influence of Recycled Fine Aggregates on Strength Properties of Reactive Powder Mortar

Doaa H. Nayyef; Shatha S. Hasan

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 288-294
DOI: 10.30684/etj.2021.168197

Although many researchers have done many studies on recycled aggregate concrete, information is very little about the influence of utilizing recycled aggregate in the production of reactive powder concrete. Experimental work was executed to investigate the influence of utilizing recycled concrete as fine aggregate in reactive powder concrete. Five different mixes were prepared, the first mix, or control mix, was prepared with natural sand, four additional mixes were prepared with different percentage of substitution of fine aggregates(20%,40%,60%, and 80%). The investigation was carried out using compressive strength test, direct tensile strength test and flexural strength test, and two methods of curing were used standard curing at 20 °C and steam curing at 90°C. the results indicated that the strength decreases with increased the percentage of recycled fine aggregate, and the best percentage was 40% replacement where the percentages of decrease at this percentage at 28-day steam curing were 2.46, 6.66, and 2.14 for compressive strength, flexural strength, and direct tensile strength respectively.

Investigation of the Effect of Nano Powder Mixed Dielectric on EDM Process

Rasha R. Elias

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 295-307
DOI: 10.30684/etj.2021.168198

In this paper, Artificial Neural Network was adopted to predict the effect of current, the concentration of aluminum oxide (Al2O3) and graphite Nanopowders in dielectric fluid for the machining of Carbon steel 304 using Electrical Discharge Machining (EDM). The process variables were utilized to find their effect on Material Removal Rate (MRR), Surface Roughness (SR), and Tool Wear Rate (TWR). It was revealed from the experimental work that the addition of aluminum oxide and graphite Nanopowders into dielectric fluid maximizing MRR, minimized the SR and TWR at various variables. Minitab software was used in the design of experiments. Analysis of the process outputs of EDM indicates that graphite powder concentration greatly influencing SR also the discharge current whereas the current and Nanopowders concentration has more percentage of influence on the TWR and MRR.

Improved Wear Rate Resistance, Compression Strength and Hardness of Polymethylmethacrylate Resin with Orange Peel Powder for Artificial Denture Base

Reem A. Mohammed

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 308-318
DOI: 10.30684/etj.2021.168199

The material utilized for manufacturing artificial dentures should have high-grade mechanical properties in order to resist heavy forces inside the mouth. This study includes investigation of some of the mechanical properties (wear rate resistance, compression strength, and hardness) of the specimens prepared by (hand lay-up) method. The wear behavior experiments were performed on (a pin-on-disk tester) under various factors 5%, 8%, 11%, 14%, 17% weight fraction of orange peel, (10, 15, 20 N) load applied and (5, 10, 15 minutes) sliding time, and analysis these experimentally by using the Taguchi’s experimental design (L9) (MINITAB 16). Tests explicated that the specimens (polymethylmethacrylate - 17% orange peel) composites have the best wear rate resistance, compression strength and hardness shore D (0.040×10-5 cm3/N.mm, 142 MPa, 86 shore D) respectively than other specimens (polymethylmethacrylate - 5%, 8%, 11%, 14% wt. orange peel) and these specimens better than the specimens standard polymethylmethacrylate, which could be attributed to the homogeneous dispersion of orange peel particles in the polymethylmethacrylate resin matrix. The results (signal to noise ratio) showed the factors (17% weight fraction) orange peels, (20 N) load applied, and (5 min) sliding time gives the best wear rate resistance. The results of the analysis of variance showed the sliding time (C) is the essential factor effect on the wear rate resistance followed by (A) weight fraction of orange peels and (B) load applied were less affected on wear behavior rate.

Improving the Stability and Critical Speed of Rotor Bearing System By Using External Damping Source

Tariq M. Hammza; Nassear R. Hmoad; Ehab N. Abas

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 319-324
DOI: 10.30684/etj.2021.168200

Improving the essential factors of rotor bearing system are the aim of this study. In addition to the presence of two ball bearings to support the rotor, two additional fluid film journal bearings have been used as an external damping sources. The ANSYS Mechanical APDL 18.0 was used to model rotor bearing system with existence of two additional fluid film journal bearings. Matlab software has been used to achieve the analytical solution. The results clearly showed that the maximum response displacement strongly decreasing and the critical speed has been enhance by using an external damping source as well as the stability of rotor bearing system has been improved due to increasing damping of rotor system where the response displacement decreasing by 99% and critical speed increasing by 0.6% when using an external damping sources. The position of damping source has an important effect on the maximum response displacement and the more decreasing value of response displacement has been achieved when the damping source become as close as possible to the disk position.

Effect of Laser Shock Peening on Fatigue Stress Concentration of Polyester Reinforced by Al-Micro Powder Composites

Ahmed N. Al- Khazraji; Ammar A. Mutasher

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 325-334
DOI: 10.30684/etj.2021.168201

Laser shock peening is a widely common process for materials treatment and typically used for fatigue strength enhancement especially for metals. In this paper, its effect on polymeric composite materials studied experimentally. Unsaturated polyester was used as a matrix in order to composites preparation and Aluminum powder as fillers. A Hand lay-up technique has been used for composites making. Composites with three volume fractions of Aluminum powder were prepared (2.5%, 5%, and 7.5%). Fatigue specimens as a standard and with (1mm) semi-circular notch are prepared for testing. The fatigue test was performed at room temperature and stress ratio (R=-1). Laser shock peening with two levels of energy have been applied (1Joule, and 2Joule). The results showed an increase in the endurance strength of the notch for 7.5% volume fraction especially at 1J laser energy by about 26.7056% compared with the un-treatment notched state, which in turn reduced the fatigue stress concentration by about 21.0508% compared with standard fatigue stress concentration. On the other hand, the presence of notch effect on endurance strength was increased after laser treatment of composites with 2.5% volume fraction and the reduced was by about 39.698% at 2J laser energy.

Production of Self-Cleaning SiO2/CNT Nanoparticles Substituted Cement Mortar

Layth Al-Gebory; Aseel B. Al‐Zubaidi; Ahmed A. Al‐Tabbakh

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 335-342
DOI: 10.30684/etj.2021.168202

Manufacturing of building materials with unique properties is one of the most important key-parameters in the development of construction engineering and building materials. The development in the nanomaterials and nanotechnology can be utilized in this field. In this paper, production of eco-friendly, low water absorption and self-cleaning cement mortar reinforced with carbon nanotubes and nano-silica with different weight percentages (0.5%, 1.5%, and 2%) is performed. Results showed prominent improvement of hardness, compression strength and a decrease of water absorption and bending resistance in the reinforced cement mortars. The results show the possibility to control the mechanical properties of the cement mortars with minimal reinforcing agents provides the possibility to design these building materials for versatile applications

Development of Path Planning Algorithm Using Probabilistic Roadmap Based on Ant Colony Optimization

Mohammed I. Abdulakareem; Firas A. Raheem

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 343-351
DOI: 10.30684/etj.v38i3A.389

In this paper, a unique combination among probabilistic roadmap, ant colony optimization, and third order B-spline curve has been proposed to solve path-planning problem in complex and very complex environments. This proposed method can be divided into three stages. First stage is to construct a random map depending on the environment complexity using probabilistic roadmap algorithm. This could be done by sampling N nodes randomly in complex and very complex static environments, then connecting these nodes together according to some criteria or conditions. The constructed roadmap contains huge number of possible random paths that may connect the start and the goal points together. Second stage includes finding path within the pre-constructed roadmap. Ant colony optimization is selected to find or to search the best path between start and goal points. Finally, the third stage uses B-spline curve to smooth and reduce total length of the found path in the previous stage where path’s length has been reduced by 1% in first environment and by 15% in second environment. The results of the proposed approach ensure feasible path between start and goal points in complex and very complex environment. In addition, the path is guaranteed to be shortest, smooth, continues and safe.

Air Temperature Modelling Depended on Remote Sensing Techniques

Zainab T. Mohammed; Riyad H. Al-Anbari; Oday Z. Jasim

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 352-360
DOI: 10.30684/etj.v38i3A.398

Air temperature (T air) near the land surface is a fundamental descriptor of physical environmental conditions and one of the most widely used climatic variables in global change studies. In this study, the researcher trying to suggest a model for estimating air temperature in summer season for any region through integrating of Iraqi Agrometeorological network
daily (T air) with the moderate resolution imaging spectroradiometer (MODIS) land surface temperature (LST), Duration Day Length (DDL) and Digital Elevation Model (DEM). In this model, using satellite images for the study area and data of air temperature for four weather stations located in Babylon governorate from 1- June to 30- September on year 2017 for modeling and accuracy assessment air temperature estimation. The standard error of this model is 1.72887° C, and the correlation equal to 0.69698.

Design and Implementation of a Fuzzy Logic Controller for Inverted Pendulum System Based on Evolutionary Optimization Algorithms

Ahmed F. Ghaliba; Ahmed A. Oglah

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 361-374
DOI: 10.30684/etj.v38i3A.400

The inverted pendulum is a standard classical problem in the branch of
control and systems. If a cart is bushed by force then its position and angle
of the pendulum will be changed. Several controllers may employed,
keeping the pendulum arm upright by controlling at the cart location. In
this search paper, the fuzzy-like PID (FPID) controller has been used to
control the inverted pendulum, and the parameters of the controller are
tuned with several evolutionary optimization algorithms like a genetic
algorithm (GA), ant colony optimization (ACO), and social spider
optimization (SSO.) The result of tuned FPID with evolutionary
optimization is compared with conventional PID, and it shows that FPID
with SSO has been given the best result.

Study of the Corrosion Behavior of Zinc-Aluminum Alloy Matrix Composite Reinforced with Nanosilica Produced by Stir Casting

Fatima A. Adnana; Niveen J. Abdul Kader; Mohammed S. Hamza

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 375-382
DOI: 10.30684/etj.v38i3A.435

In this investigation, Zn-Al alloy metal-matrix nano composites that
reinforced via various weight percentages (2%, 4%, 6%, and 8%) of
nanosilica (SiO2) particles were fabricated applying the technique of stir
casting. Behaviors of the corrosion of the unreinforced alloy and
reinforced composites were measured utilizing a potentiostat test in a (3.5
wt.% NaCl) salt solution. The optical microscopy was employed to
investigate the surface microstructure of the composite. Microstructure
analysis manifested that the uniform distributions of the reinforcing
particles in the composites are alike, consisting of a dendritic structure of
the zinc alloy matrix with an excellent reinforcing particles steady
dispersion. The improved results of the corrosion resistance for the metal
matrix composites showed an excellent resistance to corrosion than the
matrix in the (3.5 wt.% NaCl) solution. Raising the weight percentage of
the reinforcement particulates of nansilica (SiO2) reduced the composites
rate of corrosion

Analysis of Thermal and Insulation Performance of Double Glazed Window Doped With Paraffin Wax

Jalal M. Jalil; Salih M. Salih

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 383-393

In this paper, a numerical investigation has been performed to study the effect of varying the thermal properties of the paraffin wax on the performance of a double glazed window doped with it during the summer climate of Baghdad (33.3 °N, 44.4 °E). Using FORTRAN (f 90) constructed computer program, finite difference combined with the enthalpy method was utilized to deal with the conduction with phase change problems within the wax. Results obtained show that increasing the density, latent heat, and thickness of the paraffin wax PCM) would increase the temperature-time lag and reduce the temperature decrement factor of the double glazed window, and as a result, improve comparatively the performance of the unit. In contrast, changing the specific heat capacity of the paraffin wax is not a productive (inefficient) technique to develop the performance of the unit. Besides, the recommended thickness of the window (thickness of the PCM) under the ambient condition of Baghdad should be 20 mm or higher.

Influence of Cutting Speed on Residual Stresses by Machining of AISI 316L

Safa M. Lafta; Maan A. Tawfiq

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 394-401
DOI: 10.30684/etj.v38i3A.459

RS have an important role in the performance of components and machined structures. The objective of this paper is to study the influence of cutting speed on RS in workpieces that are formed in orthogonal cutting. AISI 316L stainless steel since it has been used in many important industries such as chemical, petrochemical industries, power generation, electrical engineering, and food and beverage industry. Four cutting speeds are selected: (44, 56, 71 and 88) m/min. The alloy was machined by turning at constant depth of cut and various feed rate from (0.065 to 0.228) mm/rev. Residual stresses are examined by X-ray diffraction. The best results of RS obtained are (-3735.28, -1784.95, -330.142, -218.747, -890.758, -2999.632, -2990.401) MPa. Increasing the cutting speed from (44-56) m/min. reduces the compressive residual stress by (21.4 %), while from (71-88) m/min the RS is reduced by (19.3 %). Finally, the RS at cutting speeds are changed from compression to tension

Reducing Roof Solar Heat Gain by Using Double-Skin Ventilated Roofs

Mohannad R. Ghanim; Sabah T. Ahmed

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 402-411
DOI: /10.30684/etj.v38i3A.462

Double skin ventilated roof is one of the important passive cooling techniques to reduce solar heat gain through roofs. In this research, an experimental study was performed to investigate the thermal behaviour of a double skin roof model. The model was made of two parallel galvanized steel plates. Galvanized steel has been used in the roof construction of industrial buildings and storehouses in Iraq. The effect of inclination angle (ϴ) from the horizontal and the spacing (S) between the plates was investigated at different radiation intensities. It is found that using a double skin roof arrangement with a sufficient air gap (S) can reduce the heat gain significantly. The higher the inclination angle (ϴ) the higher the ventilation rate, the lower the heat gain through the roof. In this study, increasing the air gap from 2 cm to 4 cm reduced the heat gain significantly but when the gap was further increased to 6 cm, the reduction in the heat flux was insignificant. A dimensionless correlation was also reduced between Nusselt number ( ) and the single parameter ( ⁄ ) where L is the channel length. This correlation can be handily utilized for designing of engineering applications dealing with high temperature difference natural convection heat transfer.

Kinematics Analysis of 5 DOF Robotic Arm

Tahseen F. Abaas; Ali A. Khleif; Mohanad Q. Abbood

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 412-422
DOI: 10.30684/etj.v38i3A.475

This paper presents the forward, inverse, and velocity kinematics analysis of a 5 DOF robotic arm. The Denavit-Hartenberg (DH) parameters are used to determination of the forward kinematics while an algebraic solution is used in the inverse kinematics solution to determine the position and orientation of the end effector. Jacobian matrix is used to calculate the velocity kinematics of the robotic arm. The movement of the robotic arm is accomplished using the microcontroller (Arduino Mega2560), which controlling on five servomotors of the robotic arm joints and one servo of the gripper. The position and orientation of the end effector are calculated using MATLAB software depending on the DH parameters. The results indicated the shoulder joint is more effect on the velocity of the robotic arm from the other joints, and the maximum error in the position of the end-effector occurred with the z-axis and minimum error with the y-axis.

Comparative Study of Different Organic Molecules as an Anti-Corrosion for Mild Steel in Kerosene

Eva A. Yaqo; Rana A. Anaee; Majid H. Abdulmajeed

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 423-430
DOI: 10.30684/etj.v38i3A.507

The investigation on the efficiency of three organic derivatives was done as inhibitors for carbon steel using electrochemical methods at four temperatures (303, 313, 323, and 333 K) and 100 ppm. The results showed that these prepared compounds gave good efficiencies at experimental conditions by adsorption process and they act as mixed-type inhibitor, the data of corrosion were measured and debated. Using SEM, the inhibited surface of specimens was characterized. In addition, for display the interaction between these compounds and the metallic surface, the Fourier transform infrared spectra was used. In addition, the activity of antibacterial of the inhibitors against some types of bacteria was tested.

Multiwall Carbon Nanotube / Polyvinyl Alcohol Nanofibers Film, Electrical Conductivity Improvement

Akram R. Jabur

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 431-439
DOI: 10.30684/etj.v38i3A.530

Conductive polymer films were prepared of polyvinyl alcohol (PVA) with (0, 2, 4, 6, 8, and 10) wt. % multiwalled carbon nanotubes (MWCNTs) by electrospinning technique. The morphologies of the synthesized films were tested by scanning electron microscopy (SEM). Average fiber diameters gauged statically was (115nm) for (PVA/10 wt. % MWCNT film) while (170nm) for pure PVA electro spun film. Electrical conductivity (EC) of Polymeric nanofiber films improve by increasing MWCNT addition concentration from (3.69 × 10-7 S/ cm) for the pure (PVA) film to (1.24 ×10-2 S/cm) for the film with 10 wt. % MWCNT. The maximum stress of PVA film were increased by adding MWCNTs concentration, the modulus of elasticity was enhanced from 12.87 MPa for pure PVA to 49.89 MPa for PVA/8wt% MWCNT.

Diffraction Rings Pattern and Nonlinear Optical Properties of Hybrid ZnO-NPs / Epoxy Resin

Zahraa M. AL-Asady; Ali H. AL-Hamdani

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 440-445
DOI: 10.30684/etj.v38i3A.549

In this research, the diffraction ring patterns scan and single-beam Z-scan techniques were used to measure the nonlinear refractive index (n2) and nonlinear absorption coefficient (β). Nano-composite sample, which consists of zinc oxide nanoparticles (ZnO-NPs), and epoxy resin polymer. The sample was prepared by the casting method. A second harmonic generation Nd: YAG laser, which operates at 532 nm and intensity 3183 W/cm2 was used for the two techniques. Z-scan results showed that values for nonlinear refractive index n2 and nonlinear absorption coefficient β were obtained of 6.59*10-9 cm2/W and 1.75*10-3 cm/W respectively. While results for the D-scan technique showed that the number of rings increases with the increasing of laser power.

Discontinuous Control and Stability Analysis of Step-Down DC-DC Voltage Converters

Bashar F. Midhat

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 446-456
DOI: 10.30684/etj.v38i3A.567

Step down DC-DC converters are power electronic circuits, which mainly used to convert voltage from a level to a lower level. In this paper, a discontinuous controller is proposed as a control method in order to control Step-Down DC-DC converters. A Lyapunov stability criterion is used to mathematically prove the ability of the proposed controller to give the desired voltage. Simulationsl1 are performedl1 in MATLABl1 software. The simulationl1 resultsl1 are presentedl1 for changesl1 in referencel1 voltagel1 and inputl1 voltagel1 as well as stepl1 loadl1 variations. The resultsl1 showl1 the goodl1 performancel1 of the proposedl1 discontinuousl1 controller.

Characteristics of Exhaust Emissions for a Diesel Engine Fuelled by Corn Oil Biodiesel and Blended with Diesel Fuel

Abdulrahman S. Mahmood; Haqi I. Qatta; Saadi M.D. Al-Nuzal; Talib K. Abed

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 457-464
DOI: 10.30684/etj.v38i3A.446

Environmentally friend biodiesel fuel from corn oil was tested in single-cylinder 4-stroke diesel engine operated. Three blends of fuels were prepared from corn oil and diesel fuel viz. 7, 15, and 20 % (designated as B7, B15, and B20, respectively). Tests were conducted on this engine using these blends at a constant speed (1500 rpm) and varying loads (0 % to 100 %). The emissions of carbon monoxide, carbon dioxide, unburned hydrocarbons, nitrogen oxides (NOX) and smoke opacity were measured. In all engine loads, results showed that the emission of CO, HC, and smoke emissions were reduced, while that of NOX and CO2 were increased. Biodiesel blend (B20) showed the highest decrease of the CO and HC and smoke emissions by 22.13 %, 18.5 %, and 25.8 % respectively. While that of NOX and CO2 emissions were increased by 22.3 % and 22%, respectively. It can be recommended as a sound environment friend and renewable for use in diesel engines and can be used without any significant modifications in the engine design

Cyclic Settlement of Footings of Different Shapes Resting on Clayey Soil

Aseel N. Najim; Mohammed Y. Fattah; Makki K. Al-Recaby

Engineering and Technology Journal, 2020, Volume 38, Issue 3A, Pages 465-477
DOI: 10.30684/etj.v38i3A.483

An experimental investigation is carried out to investigate the impact of the footing shape, when rested on clayey soil under cyclic loading condition. The model footings used in this study are circular, square and the area of footings is fixed. Cyclic load test is carried out on the cohesive soil with three undrained shear strengths (20 kPa, 40 kPa and 70 kPa). Two depths of foundation embedment (at surface and 5 cm) to know the effect of the depths of the foundations on the change of settlement and total vertical stress and two rates of loading (3 mm/sec and 6 mm/sec) are used. It has been observed that the bearing capacity varies in increasing order as Solid, Circular and Square. It is found that the cyclic settlement in the square foundation is less than the circular foundation. The results reveal that the shape of the footing has a significant effect on its bearing capacity and the settlement characteristics. The vertical stress reaches a constant value which is greater below circular footing and it is about (70.9 - 92.7) % greater than below square footing.