Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Jadriyah, Baghdad
Iraq
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Email: joengbag@uobaghdad.edu.iq

Table of content: 2013 volume:19 issue:11

Article
Strengthening and Closing Cracks for Existing Reinforced Concrete Girders Using Externally Post-Tensioned Tendons
تقوية و غلق الشقوق في الروافد الخرسانية المسلحة المتواجدة بأستعمال الاجهاد المسبق الخارجي

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Abstract

This research is devoted to study the strengthening technique for the existing reinforced concrete beams using external post-tensioning. An analytical methodology is proposed to predict the value of the effective prestress force for the external tendons required to close cracks in existing beams. The external prestressing force required to close cracks in existing members is only a part from the total strengthening force. A computer program created by Oukaili (1997) and developed by Alhawwassi (2008) to evaluate curvature and deflection for reinforced concrete beams or internally prestressed concrete beams is modified to evaluate the deflection and the stress of the external tendons for the externally strengthened beams using Matlab 7.0. The analytical investigation is implemented on three ideal reinforced concrete beam models, each model is considered to be strengthened using three types of external tendon profile (straight, draped and double draped), where each type of tendon profile is analyzed separately. No comparisons were made with analytical or experimental investigations, because no publications for this kind of studies were found.


Article
Effect of Velocity on Dissolved Oxygen Cathodic Polarization using a Rotating Cylinder Electrode
تأثير السرعة على الأستقطاب الكاثودي للأوكسجين بأستخدام القطب الدوار

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Abstract

The aim of the present work to study the effect of changing velocity (Reynold's number) on oxygen cathodic polarization using brass rotating cylinder electrode in 0.1, 0.3 and 0.5N NaCl solutions (PH = 7) at temperatures 40, 50 and 600C. Cathodic polarization experiments were conducted as a function of electrode rotational speed and concentration.


Article
An Investigation to the Abrasive Wear in Pipes Used for Oil Industry
دراسة التأكل بألحك على ألانابيب ألمستخدمه في المنشات النفطيه

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Abstract

The work reported in this study focusing on the abrasive wear behavior for three types of pipes used in oil industries (Carbone steel, Alloy steel and Stainless steel) using a wear apparatus for dry and wet tests, manufactured according to ASTM G65. Silica sand with hardness (1000-1100) HV was used as abrasive material. The abrasive wear of these pipes has been measured experimentally by measuring the wear rate for each case under different sliding speeds, applied loads, and sand conditions (dry or wet). All tests have been conducted using sand of particle size (200-425) µm, ambient temperature of 34.5 °C and humidity 22% (Lab conditions). The results show that the material loss due to abrasive wear increased monotonically with the applied load at constant sliding speed and constant grit size due to increasing depth of penetration in both dry and wet sand which agrees with Archard´s equation. Sliding speed show insignificant effect on the wear loss of metals at constant load and constant grit size in both dry and wet sand. Wet sand results show higher wear losses than dry sand (20-70) % due to micro abrasion – corrosion wear and high slurry concentration.


Article
Adsorption of Chromium (Vi) from Aqueous Solutions using Low Cost Adsorbent: Equilibrium and Regeneration Studies
أمتزاز الكروم الخماسي من المحاليل المائية بأستخدام مواد مازة واطئة الكلفة : دراسات التوازن وإعادة التنشيط

Authors: Ihsan Habib Dakhil
Pages: 1395-1406
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Abstract

The adsorption of Cr (VI) from aqueous solution by spent tea leaves (STL) was studied at different initial Cr (VI) concentrations, adsorbent dose, pH and contact time under batch isotherm experiments The adsorption experiments were carried out at 30°C and the effects of the four parameters on chromium uptake to establish a mathematical model description percentage removal of Cr (VI). The analysis results showed that the experimental data were adequately fitted to second order polynomial model with correlation coefficients for this model was (R2 = 0.9891). The optimum operating parameters of initial Cr (VI) concentrations, adsorbent dose, pH and contact time were 50 mg/l, 0.7625 g, 3 and 100 min, respectively. At these conditions, the maximum percentage removal of Cr (VI) was 92.88%. The amounts of Cr (VI) adsorbed onto STL were highly affected by the solution pH value. Equilibrium data was modeled with Langmuir and Freundlich models isotherms. Langmuir model is found very well represent the equilibrium data with correlation factor is close to unity than the Freundlich model. The maximum monolayer adsorption capacity was found to be 47.98 mg/g at optimum conditions. The saturated adsorbent was regenerated by base treatment and found to be reuse efficiently after fourth cycle at optimum conditions as well as for safe disposal of base that contains high concentration of Cr (VI) is precipitated as barium chromate.


Article
Image Compression Using 3-D Two-Level Techniques
ضغط الصورة باستخدام تقنيات ثنائية المستوى لثلاثي الابعاد

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Abstract

In this paper three techniques for image compression are implemented. The proposed techniques consist of three dimension (3-D) two level discrete wavelet transform (DWT), 3-D two level discrete multi-wavelet transform (DMWT) and 3-D two level hybrid (wavelet-multi-wavelet transform) technique. Daubechies and Haar are used in discrete wavelet transform and Critically Sampled preprocessing is used in discrete multi-wavelet transform. The aim is to maintain to increase the compression ratio (CR) with respect to increase the level of the transformation in case of 3-D transformation, so, the compression ratio is measured for each level. To get a good compression, the image data properties, were measured, such as, image entropy (He), percent root-mean-square difference (PRD %), energy retained (Er) and Peak Signal to Noise Ratio (PSNR). Based on testing results, a comparison between the three techniques is presented. CR in the three techniques is the same and has the largest value in the 2nd level of 3-D. The hybrid technique has the highest PSNR values in the 1st and 2nd level of 3-D and has the lowest values of (PRD %). so, the 3-D 2-level hybrid is the best technique for image compression.


Article
Construction of a General-Purpose Infrastructure for Rfid – Based Applications
تشييد البنية التحتية للتطبيقات العامة لنظام التعريف باستخذام الموجات الراديوية

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Abstract

The aim of advancements in technologies is to increase scientific development and get the overall human satisfaction and comfortability. One of the active research area in recent years that addresses the above mentioned issues, is the integration of radio frequency identification (RFID) technology into network-based systems. Even though, RFID is considered as a promising technology, it has some bleeding points. This paper identifies seven intertwined deficiencies, namely: remote setting, scalability, power saving, remote and concurrent tracking, reusability, automation, and continuity in work. This paper proposes the construction of a general purpose infrastructure for RFID-based applications (IRFID) to tackle these deficiencies. Finally, the proposed IRFID is compared against eight existing systems. As a result, IRFID can be considered as a prototype for the futuristic with flexibility and generality in a wide-range of automation and development areas.


Article
Salinity Variation of Euphrates River between Ashshinnafiyah and Assamawa Cities
التغاير الملحي في مياه نهر الفرات بين مدينتي الشنافية و السماوة

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Abstract

AshShinnafiyah and AsSamawa cities suffer from significant increase in salinity of Euphrates River water compared with their counterpart's north AshShinnafiyah city which is reflected adversely on the quality of water within the study area. The study aims to find possible solutions to avoid the deterioration of Euphrates River northern AshShinnafiyah city until AsSamawa city that were presented by total dissolved solid TDS. Twelve main hydrological and fifteen salinity measurement stations were selected to cover 117 km of the river reach within the study area during July-2011. Additional twenty three hydrological and salinity stations were adopted during March-2012, winter season to the river within the study area. After conducting the field and laboratory measurements, mathematical model using HEC-RAS v.4.1 software were implemented, using the available geometric and recorded and measured hydrological data. Eleven scenarios were adopted, by canceled one or more of the drains that cause the deterioration in the river, to find the best scenario using various discharges of Al Ya’uo Regulator (Upstream of study area), where the criteria are the water level at AsSamawa city (downstream boundary) is not less than 6 m.a.m.s.l. and the maximum acceptable salinity for agricultural purposes is 1500 mg/l according to Specification of Iraq No. 417 for maintenance of river pollution, 1967. It was concluded from both models that the problem of salinity in the study area cannot be avoided without diverting one or more of the drains that outfall in the river. The minimum instream flow MIF was found for each scenario. Euphrates River without Eastern Al-Jarah, Al-Khassf, AnNagara, and Al-Haffar Drains, and outfalls Between AshShinnafiyah and Garrb Villages, Scenario 9, is the best one, where it gave the minimum required discharge from Al-Ya’uo Regulator of 82m3/s and 165m3/s during summer and winter seasons respectively.


Article
Computational Analysis of Turbulent Natural Convection in Water Filled Tall Enclosure
تحليل حسابي للحمل الحر المضطرب في حيز طويل مملوء بالماء

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Abstract

In this study, the turbulent buoyancy driven fluid flow and heat transfer in a differentially heated rectangular enclosure filled with water is quantified numerically. The two dimensional governing differential equations are discretized using the finite volume method. SIMPLE algorithm is employed to obtain stabilized solution for high Rayleigh numbers by a computational code written in FORTRAN language. A parametric study is undertaken and the effect of Rayleigh numbers (1010 to 1014), the aspect ratio (30, 40 and 50), and the tilt angle (10o to 170o) on fluid flow and heat transfer are investigated. The results of the adopted model in the present work is compared with previously published results and a qualitative agreement and a good validation is obtained. Results show that the fluid circulation and temperature fields are strongly affected by the enclosure tilt angle and Rayleigh Number.


Article
Analytical Solution of Transient Heat Conduction through a Hollow Cylindrical Thermal Insulation Material of a Temperature Dependant Thermal Conductivity
حل تحليلي لتوصيل الحرارة المتغير مع الزمن خلال مادة أسطوانية مجوفة عازلة للحرارة ذات توصيل حراري متغير مع درجة الحرارة

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Abstract

The one-dimensional, cylindrical coordinate, non-linear partial differential equation of transient heat conduction through a hollow cylindrical thermal insulation material of a thermal conductivity temperature dependent property proposed by an available empirical function is solved analytically using Kirchhoff’s transformation. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner radius with a step change in temperature. Four thermal insulation materials were selected. An identical analytical solution was achieved when comparing the results of temperature distribution with available analytical solution for the same four case studies that assume a constant thermal conductivity. It is found that the characteristics of the thermal insulation material and the pressure value between its particles have a major effect on the rate of heat transfer and temperature profile.


Article
Serviceability behavior of High Strength Concrete I-beams reinforced with Carbon Fiber Reinforced Polymer bars
سلوك حد الخدمة للعتبات الخرسانية عالية المقاومة ذات المقطع I والمسلحة بقضبان البوليمرات المسلحة بالألياف الكربونية

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Abstract

Fiber Reinforced Polymer (FRP) bars are anisotropic in nature and have high tensile strength in the fiber direction. The use of High-Strength Concrete (HSC) allows for better use of the high-strength properties of FRP bars. The mechanical properties of FRP bars can yield to large crack widths and deflections. As a result, the design of concrete elements reinforced with FRP materials is often governed by the Serviceability Limit States (SLS). This study investigates the short-term serviceability behavior of FRP RC I-beams. Eight RC I-beams reinforced with carbon-FRP (CFRP) and four steel RC I-beams, for comparison purposes, were tested under two-point loading. Deformations on the concrete and crack widths and spacing are measured and analyzed. A discussion on the main aspects of the SLS of FRP RC is introduced. The service load that fulfills the serviceability requirements, at a cross-section level, ranges between 0.27 and 0.38 times the ultimate load for sections dimensioned to fail in concrete crushing. The determinant criterion is the deflection limitation.

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