Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 36, 4A

Volume 36, 4A, April 2018


Flexural Behavior of RC Beams Strengthened by NSM-CFRP Laminates or Bars

Ikram A. Saeed; Riadh Al-Mahaidi; Tareq S. Al-Attar; Basil S. Al-Shathr

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 358-367
DOI: 10.30684/etj.36.4A.1

The strengthening and enhancing the structures represents an important aspect in the construction industry due to the growing need to increase the tolerability of origin to a specific level and within the required rehabilitation and maintenance work. This paper assessed the performance and effectiveness of the Near Surface Mounted (NSM) strengthening technique for the reinforced concrete beams. Three (140x260x2700 mm) reinforced concrete beams were strengthened in flexure with NSM strengthening systems using Carbon Fiber Reinforced Polymer (CFRP) strips, bars, and cement-based adhesive as a binding materials. The flexural behaviour of the beams was evaluated by testing the specimens under three-point loading to failure. The structural performance, deflection, ductility, stiffness, and modes of failure of the tested beams are presented and discussed in this paper. The test results indicate that using NSM-CFRP strips and bars is practical and significantly improves the stiffness and increases the flexural capacity of reinforced concrete beams. The strength increments were 48, 42, and 15 percent recorded with CFRP bars, rough strips, and smooth strips respectively. The deflection of the strengthened beams was reduced by about 66, 48, and 58 percent for CFRP smooth strips, rough strips, and CFRP bars respectively, compared with the control beam due to the increased stiffness of the strengthened beams.

Studying of Heat Treatment Influence on Mechanical Behavior of AA6061-T6 by Desirability Function Analysis Approach

Hashim S. Neamah

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 368-372
DOI: 10.30684/etj.36.4A.2

This paper presents optimization of warmth treatment parameters for the mechanical conduct on 6061 Aluminum alloy using desirability function analysis (DFA). Stability The experiments have been carried out using Taguchi’s L9 toughness orthogonal array. The warmth treatment durability parameters certain quenching average, getting older dead heat stability or growing older heat are optimized through multi-response considerations particularly hardness yet put on obstruction .The gold standard parameters bear been determined by the decomplex desirability value near beyond desirability characteristic analysis, yet longevity enormous contribution of parameters be able keep determined by using evaluation on dissonance (ANOVA). The evaluation effects suggests so superior combination because of excessive hardness, excellent wear hindrance are The most useful heat cure prerequisites are (A2 B1 C1) i.e. growing old anger is toughness (180 oC), ageing day is permanency (2 hr.) or quenching mediocre stability (Water). The empiric consequences present that mechanical ء overall performance be able be multiplied effectively through this approach.

Comparison of the Behavior for Free Standing Pile Group and Piles of Piled Raft

Awf Al-Kaisi; Falah H. Rahil; Mohanned Waheed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 373-380
DOI: 10.30684/etj.36.4A.3

The intended task of this paper is studying the behavior of free standing pile groups and piles of piled raft driven in clayey soil under axial loading. The raft-piles interaction is investigated as well through the two series of tests. Each one of these series includes twelve tests, the two series are conducted with the same configuration, spacing, size of piles and undrained shear strength of soil except that in the free standing group there is a gap of about (20-25 mm) between the raft and the soil surface to have the applied load transferred to the piles only in order to compare the behavior of piles in the two cases. Three grades of undrained shear strength (cu) of clayey soil are selected which are (20 or 40 or 60 kPa) and the configuration of the pile groups used in all tests is (2 x 2). Two different pile lengths (L) are selected (300 and 450 mm). These lengths represent the slenderness ratio (L/D) of (10) and (15) respectively, so that the center-to-center spacing between the piles (S) used are (3D) and (5D). It is observed that piles exhibited a very high stiffness at initial loading stages till the settlement is about 0.5mm, beyond this level, even for a small increment in the load, the pile settled rapidly, which means that once the friction is overcome the piles failed instantaneously. In addition, most of the load capacity of piles is mobilized at settlement of around (1 – 2 mm), corresponding to (5 %) of pile diameter.
Moreover, the increasing the undrained shear strength of clay from (20 to 60 kPa) has no significant effect on the load transfer mechanism of piles in the two cases .
It can be concluded that the load capacity of the free standing pile group is about equal to the piles in piled raft case, indicating that the interaction effect is not significant, therefore, it is suggested to apply an efficiency factor (αG) of (1) in designing the piled - raft foundation in clayey soil when calculating for pile load share.

Design and Implementation of a Two Stage Controller for Ball and Beam System Using FPGA

Ivan A. Hashim; Ekhlas H. Karam; Noor S. Abdul-Jaleel

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 381-390
DOI: 10.30684/etj.36.4A.4

The ball and beam is, in fact, a standout amongst the essentially vital models, which are generally utilized for educating the control system because its simplicity to be built, modeled, and controlled. This system involve a ball roll on a beam and since the angle of the beam manipulate by servo motor, so the purposes of this paper is to design two stages controller to stabilize the ball position along the beam by varying the angle of beam. The First controller stage “is Proportional- Integral- Derivative” (PID) “for servo motor. The second stage of the controller is Proportional-Derivative (PD) to control the ball and beam plant. The Matlab simulation results illustrate the efficiency of this controller. Furthermore, this paper presents the complete hardware Field Programmable Gate Arrays (FPGA) design with real time implementation for the suggested controller. This controller utilized 1% of occupied slices when implement on Spartan-3A DSP 3400A Xilinx kit with 70.265 𝑛𝑠 minimum time required to complete the controller function. The experimental tests shows that the suggested two stages controller satisfy the functional requirements results.

Earth Fault Protection Failure in the Distribution Transformer 11/0.4 kV Supply

Thamir M. Abdul-Wahhab; Mohammed S. Jasim

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 391-400
DOI: 10.30684/etj.36.4A.5

This research studies a miss-coordination problem in the protection of 11 kV distribution network in Iraq. The problem arises when an underground cable is exposed to an earth fault at a location between the High Rupturing Capacity (HRC) fuses and the high voltage windings of the distribution transformer. In this case, the protective relay of the main circuit breaker of the feeder operates at a time faster than the HRC fuses of the faulty transformer. The distribution network considered in this work is an underground 11kV distribution network at Al-Rusafa General Directorate geographical region in Baghdad city. The problem was studied using mathematical analysis and software analysis. The mathematical results and the analysis of the simulated network using CYME 7.1 program show that the relay will operate before the HRC fuses as a response to an earth fault occurrence on that part of the network. To solve this problem several solutions are proposed and discussed in this research.

Using Polyethylene Glycol to Produce Self Cured Cement Mortar

Rasha Rawdhan; Awham M. Hameed; Shakir A. Salih

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 401-409
DOI: 10.30684/etj.36.4A.6

The capacity of self-curing admixture is to reduce the evaporation of water from mortar, and subsequently they increase the ability of water retention from mortar contrasted with those traditionally cured mortar. Polymeric phase is disperse in cement causing diminish in water absorption and Likewise its connection with hydrating cement create further bond formation which lead to the increment in strength. In this study two group of mortar samples were prepared, first group consist reference and fly ash mortar, second group prepare with admixtures of polymer were PEG 400 used as self-curing agent in this study. Flow test and setting time performed on fresh mortar to reach to the optimum standard specifications. Two mechanical test were carried out include compressive, tensile strength tests, the effect of PEG 400 on bulk density of polymer-modified hardened mortar also studied. The optimum results observed at the age of curing 28 days for PEG wt% 1and 3 were 39.4 and 37.7 MPa for compressive strength tests respectively, and the tensile strength at the age of curing 28 days for PEG wt% 1and 3 were 3.67 and 4.1 MPa respectively, bulk density decrease when increasing the percentage of PEG.

Effect of Nano Carbon Tube on the Mechanical and Physical Properties of Composites Based on Resin Route

Aseel B. Abdul-Hussein; Emad S. AL-Hassani; Marwa S. Atallah

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 410-416
DOI: 10.30684/etj.36.4A.7

In this work, the physical and mechanical properties of nano composites are investigate. The nano composites consist of matrix was polyester resin and 3% volume fractions of glass fibers as reinforcement with (0.5%, 1%, 1.5%, 2 %( volume fractions of carbon nanotube as filler. Samples of nano composite materials in this research have been prepared by hand – layup. The results showed that the sample (UP+3% GF) has higher water absorption than sample net polyester. As can be noted from the results that the sample (UP+3% GF+2% CNTs) has higher value water absorption than other samples. Also can be observed from the results that the sample (UP +3%GF+0.5 CNTs) has high values of hardness (shore D), flexural strength, impact strength and fracture toughness from other (1%, 1.5%, 2%) volume fraction carbon nano tube.

Removal of Cr (VI) and Cu (II) Ions from Synthetic Wastewater by Solar Photocatalytic Reactor

Mohammad F. Abid; Luma H. Mahmood; Noor H. Hamza; Sukaine J. Mohamed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 417-423
DOI: 10.30684/etj.36.4A.8

Heavy metal ions in wastewater have promoted increasing concern on environmental and health risks. The present work was devoted to investigate the feasibility of utilizing solar light to degrade Cr (VI) and Cu (II) ions in synthetic wastewater. The effect of the key process parameters on the quality of product was studied by varying the pH (3, 5, 7, 9, and 11), H2O2 (50, 100, 200, and 300 mg/L) and TiO2 loading (0.9, 1.3, and 1.7 g/L). Experimental results revealed that after 120 min of solar illumination the highest reduction of Cr (VI) ions was 97.0% obtained under (pH = 3, catalyst loading = 1.3 g TiO2/L, and H2O2 =100 mg/L) and for Cu (II) ions the highest reduction was 97.7% at (pH = 11, catalyst loading = 1.3 g TiO2/L, and H2O2 =200 mg/L). Empirical correlations were suggested for the photoreduction of Cr (VI) and Cu (II) ions as functions of the studied operating parameters with correlation coefficients of 0.946 and 0.948, respectively.

Design of Compact Dual-Mode BPFs Based on Cantor Fractal Geometry with U-Shaped Capacitive Coupling

Seevan F. Abdulkareem

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 424-429
DOI: 10.30684/etj.36.4A.9

This study displays two microstrip bandpass filters using dual mode loop and patch resonators in form of Cantor geometry. The proposed filters exhibits one and two bands frequency responses for each of them respectively. The microstrip filter using Cantor loop has been tested by AWR 12 software package at resonances of 4.55 and 4.58 GHz, whereas for Cantor dual band patch filter has been simulated at band frequencies of 3.6 and 6.84 GHz respectively. RT/ Duroid 6010 substrate has been adopted for filter designs with thickness and relative permittivity of 1.27 mm and 10.8, respectively. The simulated filters have notable miniaturization and frequency performances that stand for looked-for facets of the contemporary wireless uses.

Numerical and Experimental Study of Cooling in Desktop Computer with Block Heat Sink

Jalal M. Jalil; Ekbal H. Ali; Hiba H. Kurdi

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 430-438
DOI: 10.30684/etj.36.4A.10

This paper investigates numerically and experimentally fluid flow and heat transfer inside the desktop P.C.. The study of cooling considers the components; CPU, heat sink, power supply, motherboard, CD, HDD and fans. Three components have heat source (CPU, motherboard and power supply unit). There were two openings for air inlet and two for air outlet. The tested values of air inlet velocities were 1.2, 1.8 and 2.4 m/s. The work investigates the effect of inlet air velocity and powers (PCPU = 8.5 W, PPSU = 24 W, PMO=12 W) of multi-components (CPU, motherboard and PSU). The numerical results obtained (by finite volume method CFD) are found in a good agreement with the experimental results. The results show that the highest temperature for CPU with block heat sink was 88.1℃ (PCPU = 8.5 W, PPSU = 24 W, PMO=12 W), the temperature of the heat generation components decreases linearly with increases of inlet air velocity. The CPU temperature increases with CPU power linearly. Motherboard temperature was the lowest one due to its position and area (52oC). Full details of flow field and temperature distribution are shown.

Effect of DEM and Land Cover Resolutions on Simulated Runoff of Adhaim Watershed by SWAT Model

Mahmoud Saleh Al-Khafaji; Fouad Saeed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 439-448
DOI: 10.30684/etj.36.4A.11

Accurate estimation of surface runoff by using Soil and Water Assessment Tool (SWAT) model is highly depends on the accuracy of the Digital Elevation Model (DEM), Land Cove and Land Use (LC/LU), soil and weather data as input variables. The interactive and complementary effects of the DEM and LC/LU resolutions on the estimated runoff were not taken into consideration in previous studies. This research aims to study these effects on the accuracy of runoff estimation of Adhaim Watershed by using SWAT Model. Twenty surface runoff estimation SWAT models of Adhaim Watershed were implemented using five DEMs with spatial resolution of 30, 50, 90, 250 and 1000m in conjunction with four LC/LUs with spatial resolution of 30, 300, 500 and 1000 m. These models were calibrated and verified on daily time step with the adoption of maximizing Nash and Sutcliffe Efficiency (NS) as an objective function. The results of SWAT models show that specifying the watershed boundary and the total area is highly affected by the DEM resolution without considerable trend. Also, the estimated minimum altitude is inversely related to the DEM resolution, whereas the maximum altitude has a direct relationship. Furthermore, LC/LU resolution is highly affected the number and area of classes that can be distinguished in the LC/LU image. Although, the number of hydrologic response units (HRUs) depends on LC/LU resolution, it was found that this number increases with the increase in LC/LU resolution to a maximum number of HRUs and then it gradually decreases. Whereas, the HRUs has a direct relationship with the DEM resolution and the number of subbasins irregularly changed with the increase of DEM resolution. Results of runoff estimation by using SWAT models show that the estimated runoff is not directly or inversely related to the DEM and LC/LU resolutions. Moreover, the most accurate runoff was not estimated with the highest DEM and LC/LU resolutions, where it is obtained with DEM and LC/LU resolutions of 250 m and 1000 m respectively with NS of 0.74. Accordingly, it is recommended to use these resolutions for estimating the surface runoff of Adhaim Watershed. The relationship between the HRUs and estimated runoff is very complex therefore; more extensive studies are required to comprehend this relationship.

Strength Evaluation of Hybrid Reinforced Concrete Columns under Eccentric Loads

Ammar A. Ali; Zaynab S. Mohammed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 449-455
DOI: 10.30684/etj.36.4A.12

This study presents an experimental investigation of the behavior of hybrid circular columns composed of outer precast reactive powder concrete (RPC) tubes filled with normal concrete (NC). The column specimens were subjected to an eccentric load producing both flexural and axial stresses within the section. The specimens consisting of 200 mm outer diameter with 400 mm height. The column specimens were divided into three groups, each group contains two specimens of thicknesses of outer RPC walls of 50 and 25 mm that filled with NC, in addition to RPC solid column section. The columns of first group were without any reinforcement. While the second group specimens were longitudinally reinforced, in addition to 180 mm spaced ties. The third group is composed of the same details as that of group two but with 90 mm ties spacing. The results show that, All RPC solid specimens give a higher load capacity from that of the hybrid specimens about 48%. It is noticed that increasing the RPC outer wall thickness improves the ultimate load capacity by 11% for hybrid specimens with 50 mm thickness wall than that of hybrid specimens with 25 mm thickness wall. Also, longitudinal and transverse reinforcement noticeably enhance the ductility and strength of the tested specimens compared with corresponding plain specimens.

A Mathematical Model to Determination of Alum Amount Added for the Purpose of Coagulation in Water Purification Plants

Hassan A. Omran; Mizher A. Kadhim

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 456-460
DOI: 10.30684/etj.36.4A.13

Chemicals are used to increase the settling velocity for suspended deposition colloids which are not settled in sedimentation tanks in water purification plants . For this purpose, the alum is used in wide spread across the water purification projects in Iraq. This research contains studying the factors that effect on alum amount added by conducting laboratory tests of water samples from Euphrates river at the purification plant in AL-Musayyab city over ten years (with monthly rate). It was noted that the amount added depends heavily on the turbidity of water entering the purification plant, in addition to water temperature and its pH. The results of laboratory tests have been approved, which included the measurement of the turbidity, pH, temperature, and the value of alum added. Since this method is applicable in all water purification plants. The results during the period of ten years are accredited, and subjected to multi -regression analysis. A mathematical model was conducted to calculate the alum dose, which must be added depending on the raw water turbidity, temperature, and pH. This model also has been examined by using data of another years and gave satisfactory results to be up to 91% each. This model compensates the use of the Jar-test of raw water to determine the amount of alum that must be added and sufficient by measuring the turbidity, temperature, and pH of the raw water only, and then calculating the value of the required dose of alum.

Performance Evaluation of the V–basin Tube Solar Collector by Using .Different Nanoparticles and Base Fluids

Ibtisam A. Hasan; Khaliid F. Sultan

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 461-470
DOI: 10.30684/etj.36.4A.14

This research discuss the performance and evaluation of V –basin collector in heating systems of solar with different nanofluids and base fluids, where metal nanofluids [Ag (20nm) + DW + EG], and metal oxide nanofluid [TiO2 (40nm) + DW + EG]are the used operating fluids with flow rate of 25 lit/hr, 50 lit/hr and ratios of concentration (i.e. 1, 2, 3 and 5 % vol). The base fluids employed in these experiment is distilled water and ethylene glycol. The metal and oxide metal nanofluids are shown a significant improvement in the performance of V –basin tube solar collector with higher thermal conductivity as well as heat transfer comparing to the base fluid (distilled water and ethylene glycol). The metal nanofluids [Ag (20nm) + DW + EG]at 5 % vol and flow rate of 25, and 50 lit/hr showed an important impact in characteristics values of thermal solar for fR(τα),–fRULwere.–6.317 W/m2. 0K, 0.522 and.–6.524 W/m20K, .0.542, whereas for the oxide nanofluid (TiO2 (40nm) + DW+EG) were –5.523 W/m20K, 0.473 and –5.1731 W/m2. 0K, 0.502 severally. The characteristics values of thermal solar to Dw and EG for flow rate of 25 lit/hr and 50 lit/hr were – 4.033 W/m2.0K, 0.382, –4.065 W/ m2.0K, and 0.421 severally. The size and type of nanofluid are necessary to enhancement heat transfer process, and improve performance of solar collector of V-basin type. The metal and oxide nanofluids used as a working fluid may improve the thermal performance of tube solar collector of V – basin because of small nanoparticles for metal, oxide metal and high thermal conductivity of silver. The metal and oxide nanofluids achieved an improvement when it was compared to DW and EGmostly at a high. Inlet temperature. The impacts of metal .nanofluid and oxide metal nanofuids are taken into regard on solar nanofluids system of heating as well as different base fluids.

Study of some Mechanical Properties and Erosive Behavior by Taguchi Method for Hybrid Nano Composites

Reem Mohammed

Engineering and Technology Journal, 2018, Volume 36, Issue 4A, Pages 471-479
DOI: 10.30684/etj.36.4A.15

The aim of this research is study the effect Nano TiO2 powder on impact strength, fracture toughness, hardness shore (D) and erosive wear behavior of polymer composites materials are prepared by simple hand lay-up technique. The specimens was prepared by adding (1%, 2%,3%,4%,5% & 6%) weight fraction of nano powder (TiO3) has average size of (16 nm) to unsaturated polyester resin reinforcement with (5%) weight fraction of carbon fiber. The value of erosive wear rate for polymer composite materials can be obtaining after (15 hours) and under effect various parameters such as impingement angle (30 º, 45 º, 60 º, 90º), erodent size of sand silica (300, 400 ,500,600 μm) and stand-of distance (17, 19, 21,23 cm). Also in this research study effect of parameters on erosive wear rate by the used of Taguchi orthogonal arrays L16. The results show the maximum value of impact strength , fracture toughness and hardness (shore D) was founded at specimen (89% UP +5% C.F+6% TiO2) also this specimen has the best resistance to erosive wear rate under parameters (23cm stand- off distance , 300 μm erodent size of sand silica , 60 º impact angle) than other specimens. From analysis of variance (ANOVA) the filler content and impingement angle factor have more effect on erosive rate while the stand-off distance and erodent size of sand less effect on erosive wear rate .