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
Mobile:
Email: joengbag@uobaghdad.edu.iq

Table of content: 2015 volume:21 issue:10

Article
Strength Enhancement of Prestressed Concrete Dapped-End Girders
تعزيز مقاومة الروافد الخرسانية المسبقة الجهد ذات النهايات المستدقة

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Abstract

This paper presents the application of nonlinear finite element models in the analysis of dapped-ends pre-stressed reinforced concrete girders under static loading by using ANSYS software. The girder dimensions are (4.90 m span, 0.40 m depth, 0.20 m width, 0.20 m nib depth, and 0.10 m nib length) and the parameters considered in this research are the pre-stress effect, and strand profile (straight and draped). The numerical results are compared with the experimental results of the same girders. The comparisons are carried out in terms of initial prestress effect, load- deflection curve, and failure load. Good agreement was obtained between the analytical and experimental results. Even that, the numerical model was stiffer than the experimental, but; there were a good agreements in both trends and values. The difference varies in the range (5-12)% for the deflection. Results have shown that the pre-stress force has increased the static ultimate load capacity by (35%) in case of straight strand and by (97%) in case of draped strand


Article
The Effect of Recycled Heating and Cooling and The Effect of The Speciment Size on The Compressive Strength of Concrete Exposed To High Temperature
تاثير تعاقب دورات التسخين والتبريد وتأثير حجم النماذج على مقاومة إنضغاط الخرسانة المعرضة لدرجات حرارة عالية

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Abstract

In the present work effect of recycled heating and cooling on the values of concrete compressive strength due to high temperature of 4000C was studied. The tests show that the percent of reduction in compressive strength of the samples which exposed to a temperature of 4000C for one cycle was 32.5%, while the reduction was 52.7% for the samples which were exposed to recycled heating and cooling of ten times . Moreover a study of the effect of specimen sizes on the percentages of compressive strength reduction due to high temperatures (250, 500, 7500C) with the variation of cub's size (100, 150, 200 mm) was studied. The tests show that the rate of reduction in compressive strength increases with increasing the exposed temperatures, but, the rate of reduction was decreased as the specimen size was increased.

Keywords


Article
Study of Energy Gains by Orientation of Solar Collectors in Baghdad City
دراسة أرباح الطاقة من توجيه المجمعات الشمسية في مدينة بغداد

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Abstract

Firstly, in this study, a brief updated description and applications of different solar collectors used in renewable energy systems for supplying electric and thermal energy was presented. Secondly, an attempt was made to utilize tilting orientation of solar collector for maximizing collector energy with time in respect to horizontal orientation. For energy calculation, global solar radiation was used since they are directly related. For that purpose, field measurements of half-hourly radiation on two flat panels of tilting and horizontal orientations were carried out throughout 8-month period under local climate of Baghdad. Then, energy gain and radiation level averages were calculated based on the field radiation data using Excel programming. The tilting orientation was found to be more effective for the winter months with significant energy gains of larger than 40% and maximum gain of 58%. On the contrary, the radiation levels on collector were lower during winter months. Finally, for clear sky condition, the average solar radiations for tilting and horizontal orientations of collector were of 910 W/m2 and 713 W/m2 respectively.


Article
Studying the Utility of Using Reed and Sawdust as Waste Materials to Produce Cementitious Building Units
دراسة إمكانية الاستفادة من استخدام القصب ونشارة الخشب كمخلفات لانتاج وحدات بنائية

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Abstract

In this research, the possibility of using waste wooden materials (reed and sawdust) was studied to produce sustainable and thermal insulation lightweight building units , which has economic and environmental advantages. This study is intended to produce light weight building units with low thermal conductivity, so it can be used as partitions to improve the thermal insulation in buildings. Waste wooden materials were used as a partial replacement of natural sand, in different percentages (10, 20, 30, and 40) % . The mix proportions were (1:2.5) (cement: fine aggregate) with w/c of 0.4. The values of 28 days oven dry density ranged between (2060-1693) kg/m3.The thermal conductivity decreased from (0.745 to 0.222) W/m. K .The percentages of decrease in 28 days compressive strength were (30.8, 36.8, 50 and 56.4) % .The flexural strength increased at low replacement of reed and sawdust content, and then it decreases with the increase of reed and sawdust content. At the end of the work, building units were produced from selected mix (natural sand with 30 % reed and sawdust) (MS30) .Two types of brick units were produced; the first type without coating reed or sawdust and the second type was coated with bituminous emulsion. The coating with bituminous emulsion increased the compressive by about (20.3) % and the water absorption was reduced by about (30.4) %. Efflorescence was almost negligible for both types of bricks.


Article
Numerical Simulation of Natural Convection Heat Transfer from Interrupted Rectangular Fins
نمذجة رقمية لانتقال الحرارة بالحمل الحر من خلال زعانف غير متصلة مستطيلة المقطع

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Abstract

Numerical simulations have been investigated to study the external free convective heat transfer from a vertically rectangular interrupted fin arrays. The continuity, Naver-Stockes and energy equations have been solved for steady-state, incompressible, two dimensional, laminar with Boussiuesq approximation by Fluent 15 software. The performance of interrupted fins was evaluated to gain the optimum ratio of interrupted length to fin length (


Article
Modeling and Optimization the Influence of CO2-MAG Welding Parameters on the Weld Joint Shape Factors
نمذجة وامثلية تأثير متغيرات لحام القوس المعدني بغاز CO2 على عوامل شكل وصلة اللحام

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Abstract

This paper represents an experimentalattempt to predict the influence of CO2-MAG welding variables on the shape factors of the weld joint geometry. Theinput variables were welding arc voltage, wire feeding speed and gas flow rate to investigate their effects on the shape factorsof the weld joint geometry in terms of weld joint dimensions (bead width, reinforcement height, and penetration). Design of experiment with response surface methodology technique was employed to buildmathematical models for shape factors in terms of the input welding variables. Thepredicted models were found quadratic type and statistically checked by ANOVA analysis for adequacy purpose. Also, numerical and graphical optimizations were carried out to determine the optimum values for all responses and input variables. The optimum values of the voltage, wire feeding speed, gas flow rate, WPSF, and WRFF are (20 Volt), (153 cm/min), (10 L/min), (5.222), and (3.970), respectively. And, a good agreement was found between the experimental and predicted results. The weld joint efficiency was found (73%) at the optimum conditions.


Article
Wear Rate and Hardness of Boride Low Carbon Steel
معدل البلى والصلادة للفولاذ الواطئ الكاربون المبورن

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Abstract

There are no single materials which can withstand all the extreme operating conditions in modern technology. Protection of the metals from hostile environments has therefore become a technical and economic necessity. In this work, for enhancing their wear-resistance, boride layers were deposited on the surface of low carbon steel by a pack cementation method at 850 °C for (2, 4, and 6) h using vacuum furnace. The boronizing process was achieved using different concentration of boron source (20, 25, and 30) % wt. into coating mixture to optimize the best conditions which ensure the higher properties with lower time. The coating was characteristic by X ray diffraction (XRD), and it is confirmed the presence of (Fe2B) and (FeB) in the coating. The wear rate, hardness and thickness of the boride layers were measured, and it was observed that they effected by concentration of boron and time holding of boronizing process. Experimental results show that the higher properties of coating layer were obtained with 30% wt. of boron concentration and 4 h time holding.


Article
Predicting Crop Coefficient Values of Cucumber (Cucumis sativus) inside Greenhouse
داخل البيوت الخضراء (Cucumissativus)أستنباط معامل الخيار

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Abstract

The objective of the study was to predict crop coefficient (Kc) values for cucumber inside the greenhouse during the growing season 2014, using watermarks gypsum blocks and atmometer apparatus during the growing stages and to compare the predicted values of the crop coefficient with different methods and approaches. The study was conducted in the greenhouses field within Al-Mahawil Township, 70 km south of Baghdad, Iraq. The watermarks soil water sensors and atmometer apparatus were used to measure crop evapotranspiration and reference evapotranspiration on daily basis, respectively. The comparison and the statistical analysis between the calculated Kc in this study and values obtained from greenhouse gave a good agreement. The root mean square difference (RMSD) and relative error (RE) gave an average value of: 0.065 mm/day and 9%, respectively. While, the comparison between the predicted Kc values and approaches developed by FAO (modified) and Ministry of Water Resources of Iraq gave less agreement. The values of RMSD and RE gave an average value of: 0.188 mm/day, 27%, and 0.17 mm/day and 26.8%, respectively. The method used by FAO and Ministry of Water Resources of Iraq was conducted on basis of using modified empirical equation suggested by FAO-56.


Article
Quality Assurance for Iraqi Bottled Water Specifications
ضمان نوعية مواصفات المياه العراقية المعبأة بالقناني

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Abstract

In this research the specifications of Iraqi drinking bottled water brands are investigated throughout the comparison between local brands, Saudi Arabia and the World Health Organization (WHO) for bottled water standard specifications. These specifications were also compared to that of Iraqi Tap Water standards. To reveal variations in the specifications for Iraqi bottled water, and above mentioned standards some quality control tools are conducted for more than 33% of different bottled water brands (of different origins such as spring, purified,..etc) in Iraq by investigating the selected quality parameters registered on their marketing labels. Results employing Minitab software (ver. 16) to generate X bar, and Pareto chart. It was found from X bar charts that the quality parameters of some drinking bottled water brands are not within Iraqi standards set by the “Central Agency for Standardization and Quality Control” such as pH values, Fe, Na, and Mg concentrations. While the comparison of previously mentioned standard specifications through radar chart many important issues are detected such as the absence of lower limits the whole bottled water quality parameters such as for Na and Mg also the radar chart shows that Iraqi bottled and tap water specifications are almost equal in their quality values. Also the same chart pictured the limited range of Iraqi specifications compared to that of Saudi Arabia, and WHO and the need to introduce other water specifications such as K, Na, etc. This confirms the need to improve Iraqi bottled water specifications since it was introduced on 2000. These results also highlighted the weakness of quality assurance activities since only 33 % of the investigated companies registered the whole water quality specifications as shown in Pareto chart. Other companies do not register any quality characteristics. Also certain companies should be stopped due to non-conforming specifications, yet these companies are still producing and selling their products in the local market. Quality assurance requires continually monitor the reliability (accuracy and precision processes) of Iraqi drinking bottled water companies to match the Iraqi Specification Standards, and those companies should continually approve “How good (accurate and precise) is their product( water quality) produced?”.


Article
Development of Spatial Data Infrastructure based on Free Data Integration
تطوير البنى التحتية للمعلومات المكانية بتكامل البيانات المجانية

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Abstract

In recent years, the performance of Spatial Data Infrastructures for governments and companies is a task that has gained ample attention. Different categories of geospatial data such as digital maps, coordinates, web maps, aerial and satellite images, etc., are required to realize the geospatial data components of Spatial Data Infrastructures. In general, there are two distinct types of geospatial data sources exist over the Internet: formal and informal data sources. Despite the growth of informal geospatial data sources, the integration between different free sources is not being achieved effectively. The adoption of this task can be considered the main advantage of this research. This article addresses the research question of how the integration of free geospatial data can be beneficial within domains such as Spatial Data Infrastructures. This was carried out by suggesting a common methodology that uses road networks information such as lengths, centeroids, start and end points, number of nodes and directions to integrate free and open source geospatial datasets. The methodology has been proposed for a particular case study: the use of geospatial data from OpenStreetMap and Google Earth datasets as examples of free data sources. The results revealed possible matching between the roads of OpenStreetMap and Google Earth datasets to serve the development of Spatial Data Infrastructures.

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