Journal of Engineering

1

SOME FACTORS AFFECTING THE ULTRASONIC PULSE VELOSITY TEST RESULTS OF HIGH STRENGTH CONCRETE

Nada Mahdi Fawzi, A. A. Ali

Pages: 1-5 Arabic

Abstract

The high strength concrete is characterized by its high strength, low porosity and good performance under aggressive environmental conditions. The paper presents some factors affecting the Ultrasonic Pulse Velocity test results for high strength concrete such as water/ cement ratio, type of aggregate, frequency level of transducers, dimension of the specimens and path length. An experimental equation has been derived for the prediction of compressive strength of high strength concrete from pulse velocity, which can be used for the estimation of strength. It provides more reliable prediction and can be used in precast concrete factories manufacturing precast concrete girders for bridges

Keywords

dimension of specimens frequency level of transducers high strength concrete path length type of aggregate Ultrasonic pulse velocity test Water/Cement Ratio

2

DEVELOPING OF CONCRETE TILES

: Shakier A. Al-Mashhadani, Tariq S. Al-Attar, Alaa M. Al-Khateeb

Pages: 7-21 Arabic

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Abstract

investigates the reasons for repetitive failures during concrete tiles testing. Samples including cubes, cylinders, prisms, and full-scale concrete tiles were prepared using both a popular concrete mix and a newly designed mix. The newly designed mix was formulated to meet the required flexural strength specifications. Tests showed that the newly proposed tiles were more resistant to breaking loads by 21% compared to the previous samples. The success was attributed to careful aggregate grading and concrete curing. However, potential failures due to mass production or poor quality control were noted

Keywords

aggregate grading breaking load concrete curing concrete mix design Concrete tiles flexural strength

3

A STUDY EFFECT OF SOME VARIABLES IN TIG SPOT WELDING FOR (ALUMINUM – MAGNESIUM) ALLOY

Muna K. Abbass, Haitham Y. Abdul-Majid

Pages: 23-34 Arabic

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This paper investigates the effect of various variables in spot tungsten inert gas (TIG) welding for an aluminum-magnesium alloy (type 5052-O). The study examines the influence of welding current, welding time, and arc length on the shear strength and hardness of the welds. The optimal conditions were found to be a welding current of 90 Amps, welding time of 7 seconds, and an arc length of 1.6 mm for a 1 mm thickness specimen. The maximum shear force achieved was 2.4 kN, and the highest hardness value was 53.5 Hv at the center of the weld spot. Metallurgical changes in the weld zone and heat-affected zone were also studied under these conditions

Keywords

aluminum-magnesium alloy arc length Hardness heat affected zone IG spot welding metallurgical changes Shear Strength welding current welding time

4

A FULLY AUTOMATIC GENETIC APPROACH FOR GRAYSCALE IMAGE COLORIZATION

ara\\\'a Ali Attea, Sana\\\'a Khudayer Jaddwa Al-Janaby

Pages: 237-245 Arabic

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Abstract

This paper presents a fully automatic genetic approach for grayscale image colorization. The proposed technique uses a genetic algorithm to efficiently search for the best match for each pixel in the target image using a reference colored source image. The genetic algorithm evolves a population of randomly selected individuals, representing possible color settings for the target image. A new crossover operator, Spread out Uniform Crossover (SUX), is introduced to improve the recombination scheme by spreading vital genes rather than exchanging genes between mating parents. The results demonstrate good and plausible colorizations, resembling natural colors of the objects in the target scene

Keywords

Genetic algorithm global palette Grayscale image colorization natural colors RGB colors Spread out Uniform Crossover (SUX)

5

EVALUATION OF THERMAL SRESSES IN CONTINOUOS CONCRETE BRIDGES

Ramzi B. Abdul-Ahad, hahala’a A. Al-WakeelAl-Janaby

Pages: 259-275 English

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Abstract

This paper compares three methods for analyzing continuous concrete bridges: Priestly, Abdul-Ahad, and finite elements. The study uses three standard temperature distributions (New Zealand, AASHTO, and British) to analyze concrete bridges in Baghdad. The analysis includes two continuous precast prestressed concrete bridges. The results indicate that stresses and curvature values are very sensitive to the assumed temperature distribution. The proposed analytical models can predict thermal movement and stresses due to any temperature distribution shape

Keywords

continuous concrete bridges dead and live loads Finite elements precast prestressed concrete bridges Temperature distribution Thermal Stresses

6

WATER PRESSURE EQUALIZATION IN PIPE NETWORK CASE STUDY: AL-KARADA AREAS IN BAGHDAD

Rafa Hashim Al-Suhaily, Awatif Soaded Abdul-Hameed, Hameed Mirza Mita´b

Pages: 277-293 English

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Abstract

This paper addresses the challenge of balancing increasing potable water demand with the available quantity in the Al-Karada areas of Baghdad. The study focuses on managing the pipe network in an optimal hydraulic operation state to minimize the variance in pressure between the available and minimum required pressure head. The hydraulic model simulates the optimized project with constraints such as a minimum design head of 20 meters and available commercial pipe diameters ranging from 1600 mm to 250 mm. The objective function is to minimize the cost for the suggested hydraulic solution. Pressure uniformity coefficient (UC), standard deviation, and coefficient of variance (Cv) are used to demonstrate that the pressure head at the nodes of the network is uniformly distributed. The optimal design of the case study (R9 water supply network) has an actual cost of 561,169,310 ID with uniformity indices of UC=99.565, standard deviation=3.6508, and Cv=0.1543, while the existing design has a cost of 856,617,170 ID with uniformity indices of UC=97.909, standard deviation=3.5977, and Cv=0.7906. This results in a 34.5% cost benefit for the optimal design

Keywords

Al-Karada water supply Optimal Design Pipe Network pressure equalization pressure uniformity distribution water pressure Water Supply

7

THE SELECTION OF OPTIMUM ROAD PATH USING GEOGRAPHIC INFORMATION SYSTEM (GIS )

Bashar S. Al-Joboory, Maitham M. Al-Bakry, Oday Y. Al-Hamadany

Pages: 295-303 English

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Abstract

This research utilizes a modern scientific procedure employing Geographic Information System (GIS) to select the optimum road path between two cities. The study leverages the programming facilities offered by ArcView GIS software, including its extensions for spatial analysis and 3D analysis, to solve the problem. The solution is presented as a geographic map graduated in colors, indicating the best to worst portions of land for the suggested road path. The proposed procedure was validated using conventional mathematical solutions, yielding consistent results

Keywords

3D analyst ArcView GIS geographic map GIS Model builder Spatial analysis spatial model Tin

8

DEVELOPMENT OF STATISTICAL MODEL FOR THE PREDICTION OF PERMANENT DEFORMATION IN PAVING MATERIALS

Hamed M. Alani, Namir G. Ahmed, F. Jassim

Pages: 305-316 English

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Abstract

This paper addresses the issue of permanent deformations (rutting) in asphalt pavements, which significantly impact pavement performance and service life. The study analyzes the main factors contributing to rutting and develops a statistical model to predict permanent deformation in paving materials. Data collection involved preparing 360 asphalt concrete specimens using different gradations, asphalt cement contents, filler types, and air voids, and testing them under various temperatures and stress levels. The developed model predicts rut depth based on factors such as asphalt cement content, mineral filler type, air voids, and environmental temperature

Keywords

air voids asphalt cement content asphalt pavements diametric creep environmental temperature Marshall method mineral filler type Permanent deformation rutting statistical model Superpave system

9

STATIC ANALYSIS OF THIN-WALLED CURVED BEAM ELEMENT INCLUDING WARPING EFFECTS

Adnan Falih Ali Abdul Muttalib, A. Almusawi, Ann Nafi Aussi

Pages: 317-336 English

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Abstract

This paper presents a new mathematical model for a three-dimensional thin-walled curved beam element of closed section, incorporating warping effects. The model uses a finite element procedure and includes seven degrees of freedom per node to account for warping restraint effects1. The developed warping function considers the interaction between normal warping stresses and accompanying warping shear stresses, as well as the coupled action between torsion and bending. The model also includes axial, primary, and secondary shear deformations due to warping restraint1. The validity of the element is investigated by comparing the developed program analysis results with available analytical solutions

Keywords

axial and flexural deformations finite element procedure seven degree-of-freedom per node shear deformations stiffness matrix Strain energy Thin-walled curved beam element warping effects

10

OPTIMIZATION OF THE OPERATION OF A COMPLEX WATER RESOURCES SYSTEM PART-I: ANALYSIS OF THE CONVERGENCE CRITERION IN A SOLUTION BY THE DISCRETE DIFFERENTIAL DYNAMIC PROGRAMMING

Abdulhadi Ahmed Al-Delewy, Numa Hamad Imara

Pages: 337-343 English

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This paper investigates the optimization of a complex water resources system using Discrete Differential Dynamic Programming (DDDP). The study focuses on analyzing the convergence criterion in the iterative solution procedure. The objective function is formulated as the maximum real monetary return. The research tested seven new styles for a unique convergence criterion, comparing them with traditional criteria. The results showed that the new convergence criterion (style 7) was the most effective among the tested criteria, considering both monetary return and the number of iterations performed

Keywords

Convergence criterion Discrete Differential Dynamic Programming (DDDP) iterative solution procedure monetary return Optimization Model water resources system

11

PHYSICAL ADSORPTION OF REFORMING CATALYST BYNITROGEN

Abdul Halim A.K. Mohammed, Hussain K. Hussain, Tariq M. Naife

Pages: 345-359 English

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Abstract

This paper investigates the physical adsorption of nitrogen gas on seven commercial platinum reforming catalysts and four prepared platinum catalysts supported on alumina. The study was conducted using the Accelerated Surface Area and Porosimetry (ASAP 2400 device) at 77 K. The results indicate that the surface area generally decreases with increasing platinum percentage. High platinum-loaded catalysts (0.45% and 0.55%) showed a lower percentage increase in surface area compared to low platinum-loaded catalysts. At very high platinum loading (0.6% Pt), a reduction in surface area was observed. The precipitation of Re and Ir metals with 0.35% and 0.6% platinum increased the surface area, while the precipitation of 0.57% Sn with 0.375% Pt/alumina decreased the surface area

Keywords

77 K Accelerated Surface Area and Porosimetry (ASAP 2400 device) BET method nitrogen adsorption Physisorption platinum reforming catalysts surface area

12

EFFECT OF STARVATION ON THERMOELASTOHYDRODYNAMIC LUBRICATION OF ROLLING / SLIDING CONTACT

Basim A. Abbas, Somer M. Nacy

Pages: 361-372 English

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Abstract

This paper presents a complete numerical solution of thermal compressible elastohydrodynamic lubrication of rolling/sliding contact to determine the effect of inlet boundary condition on the film shape, film pressure, and film temperature in an elastohydrodynamic line contact problem. The direct iterative technique is used to solve the simultaneous system of Reynolds, elasticity, and energy equations for different locations of inlet oil fed. The effects of various load, speed, and slip conditions are investigated. The results indicate that starvation increases oil film temperature and decreases oil film thickness, with temperature effects being significant and not negligible

Keywords

elasticity equation energy equation film pressure film shape film temperature Hydrodynamic Lubrication inlet boundary condition iterative technique load porous journal bearing Reynolds equation slip conditions Speed thermal compressible elastohydrodynamic lubrication

13

CONSTRUCTION RISK MANAGEMENT

William Malsam

Pages: 1-5 English

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This article provides an introduction to construction risk management, which involves evaluating and implementing procedures to reduce the impact of risks in construction projects. It covers the basics of what a construction project manager is responsible for, types of risks in construction projects, and how to deliver a successful project. The article emphasizes the importance of creating a detailed construction risk management plan to identify, monitor, and mitigate risks as they arise

Keywords

Construction risk management financial risks legal risks Project Management Project risks risk assessment risk identification risk mitigation safety hazards

14

PREDICTION OF AERODYNAMIC COEFFICIENTS OF MISSILE USING PANEL METHOD

Kamil I. AL-Doulaimi, Hussain Y. M., Wisam Mohsin Jabur

Pages: 389-404 English

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Abstract

The low order panel method with Neumann boundary condition has been used to predict the normal force curve slope, the pitching moment curve slope, the center of pressure location, and the aerodynamic load distribution for a missile in compressible, steady flow. The wing-body-canard interference problem has been solved using two schemes (iterative method and internal singularity method), both based on the panel method. The normal force curve slope, the pitching moment curve slope, and the center of pressure location for a given missile have been predicted using the present numerical method and the DATCOM technique

Keywords

Missile aerodynamic panel method potential flow simulation prediction of aerodynamic coefficients wing-body aerodynamic

15

HARDNESS REMOVAL FROM DRINKING WATER

Nawar O. A. Nasser, Ahmed A. M. Ali

Pages: 405-413 English

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Abstract

This study investigates the use of lime (calcium hydroxide) to remove hardness from drinking water. Three trials were conducted in December 2003 at three water treatment plants in Baghdad: Nissan, Al-Karama, and Al-Wathba. Various doses of lime were added to the water, and the hardness, electrical conductivity, and pH were measured. The results showed a nonlinear relationship between lime dose and hardness removal. The optimal lime dose was found to be 200 ppm for Nissan, resulting in 36% hardness removal, while 300 ppm was optimal for Al-Karama and Al-Wathba, resulting in 34% hardness removal. The low percentage removal indicates the presence of non-carbonate hardness, which cannot be removed by lime alone

Keywords

Hardness lime Water treatment plant

16

DESIGN & IMPLEMENTATION OF FRACTIONAL – N FREQUENCY SYNTHESIZER

Ali M. N. Hassan

Pages: 415-427 English

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Abstract

This research involves the design and implementation of a fractional – N frequency synthesizer with the following specifications: Frequency range (2350–2750 MHz), Step size (1 kHz), Switching time (8.9 µs), Phase noise @10 kHz (-115 dBc), and Spurious (-69 dBc). The third-order Fractional – N technique was chosen to satisfy the design requirements. The Σ∆modulator is placed on a digital phase-locked loop (PLL) to control the fractional value of the frequency division ratio, thereby eliminating spurious and allowing good phase noise performance. The development in I.C. technology provides simplicity in the design of fractional – N frequency synthesizers because it implements the phase frequency detector (PFD), prescalar, Σ∆modulator, and reference divider in a single chip. Therefore, the system consists of a single chip containing a low phase noise PFD, charge pump, prescalar, Σ∆modulator, and reference divider, voltage-controlled oscillator, loop filter, and reference oscillator. The application of this synthesizer in frequency hopping systems, wireless transceivers, GSM, and radar is highlighted due to its high switching speed, low phase noise, and low spurious level

Keywords

Fractional-N frequency synthesizer frequency hopping systems GSM phase-locked loop (PLL) Radar wireless transceivers Σ∆modulator

17

STIFFNESS AND DAMPING PROPERTIES OF EMBEDDED MACHINE FOUNDATIONS

Thamir K. Al-Azawi, Raad K. Al-Azawi, Zuhair K. Al-Jaberi

Pages: 429-444 English

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Abstract

This study conducts a dynamic analysis of machine foundations under vertical excitations, considering the effects of embedment and foundation geometry. The stiffness and damping of soil are treated as frequency-dependent properties. A computer program (CPESP) coded in FORTRAN was used to evaluate the stiffness and damping coefficients based on excitation frequency and embedment depth. Results indicate that increasing embedment depth leads to higher resonant frequency and lower vibration amplitude

Keywords

Damping dynamic analysis embedment finite element analysis machine foundation resonant frequency stiffness vibration amplitude

18

NFLUENCE OF VARIABILITY IN FLEXIBLE PAVEMENT PARAMETERS ON BACKCALCULATED MODULI

Namir G. Ahmed

Pages: 445-457 English

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Abstract

This study investigates the influence of variability in flexible pavement parameters on backcalculated moduli. The research uses the Falling Weight Deflectometer (FWD) to determine the stiffness profile of existing pavements. Theoretical deflection basins were generated using the Mich-pave program, and the Mich-back program was used to backcalculate the moduli from these basins. A Monte Carlo simulation process assessed the influence of variability in thickness, Poisson's ratio, FWD load, and deflection. Results indicate that the backcalculation of layer moduli is greatly influenced by the variability of the combined pavement, with uncertainties in thickness being the major contributor to variations in backcalculated moduli

Keywords

backcalculation analysis Flexible pavement parameters Mich-back Mich-pave Monte Carlo simulation Sensitivity analysis

19

POSSIBILITY STUDY OF KEROSENE FRACTION PRODUCED FROM YEMEN CRUDE OIL AS JET FUEL WITH HIGH QUALITY SPECIFICATION

Amed Nasser Bin Harharah, Salmin Saed Elshaamal

Pages: 37-49 English

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Abstract

This study investigates the potential of using kerosene fraction produced from Yemen crude oil as jet fuel meeting high-quality specifications. Laboratory investigations and comparisons between laboratory and commercial samples of Yemeni kerosene distillates were conducted. The physico-chemical properties of the kerosene distillates were determined, confirming their suitability as aviation turbine fuel. The carbon content distribution includes 15% normal paraffin, 50% branched paraffin, 2% mono-cycloalkanes, 16% bicycloalkanes, 16% branched mono-cycloaromat with branches prevailing, and 1% bicycloaromat. The samples are not hygroscopic for a long period, and the smoke point is within higher limits, while the freezing point is within lower limits. These properties indicate that Yemeni kerosene can be prepared for a range of jet aircraft, allowing for high flying height and velocity without the need for chemical additives, although a portion of paraffin isomers may be required

Keywords

: Kerosene fraction aviation turbine fuel Density freezing point hygroscopicity jet fuel paraffins physico-chemical properties smoke point Yemen crude oil

20

AEROTRIANGULATION BY COPLANARITY

Fanar Mansour

Pages: 247-258 English

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Abstract

This research addresses the classic photogrammetric problem of aerotriangulation, which involves determining the position and orientation of one camera relative to another to recover distances to objects in a scene. The study introduces a simple iterative scheme for recovering relative orientation and applying the intersection problem using the condition of coplanarity, rather than the more commonly used collinearity condition. The data required includes pairs of corresponding rays from the two projection centers to points in the scene, with at least five pairs of rays needed. The results demonstrate significant variances in angular orientation elements, and the programs were implemented using Matlab software version 5.3

Keywords

Analytical Aerotriangulation Analytical Photogrammetry Coplanarity Condition photogrammetry

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