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.

Loading...
Contact info

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

Table of content: 2013 volume:19 issue:3

Article
The Structural systems and expressional function for Airport Terminals' buildings
النظــــم المنشئيــــــة والوظيفـــة التعبيريــــة في أبنية محطات المطارات

Loading...
Loading...
Abstract

The research deals with the structures of the contemporary travelers' buildings in particular, and which is a functional complex installations where flexibility, technical and stereotypes play an important role as well as the human values These facilities must represent physiological and psychological comfort for travelers. TThose are facilities where architectural form plays a distinguished role in reversing the specialty and identity of the building. Hence the importance of the subject has been in forced, as a result for the need to study these facilities and to determine the impact and affects by the surrounding environment, to the extent of the urban, environmental, urban, social, and psychological levels. The importance of the research highlights the i role, played by airports terminal buildings in recent times, and the necessity to study its expressional and, aesthetic levels and methods of application, examining its integration with construction level , where these integrations play a major role in giving expressive symbolism and iconography to these construction. The local libraries , in particular ,lack architecture studies which is related to the subject, mentioned above to settle the problem of research, represented by the shortage of studies about the role, played by structural systems in achieving the symbolic expressive function for airport buildings and terminals. Research hypothesis has been stated as following: structural systems are the tools of expressive and symbolic language for buildings of the airport stations, in integration with functional and operational system and the complex motion of these buildings. The main research objective has been determined to clarify the role of the construction system in highlighting the expressive function of these buildings as an identity for the place and special interface characteristic of a civilized country in question which reflects its local privacy by being the first point of intercourse with travelers and tourists' arrivals and departures of the country.


Article
Behavior of Partially Saturated Cohesive Soil under Strip Footing
تصرف الترب المتماسكة و المشبعة جزئيا بالماء أسفل الأساس الشريطي

Loading...
Loading...
Abstract

In this paper, a shallow foundation (strip footing), 1 m in width is assumed to be constructed on fully saturated and partially saturated Iraqi soils, and analyzed by finite element method. A procedure is proposed to define the H – modulus function from the soil water characteristic curve which is measured by the filter paper method. Fitting methods are applied through the program (SoilVision). Then, the soil water characteristic curve is converted to relation correlating the void ratio and matric suction. The slope of the latter relation can be used to define the H – modulus function. The finite element programs SIGMA/W and SEEP/W are then used in the analysis. Eight nodded isoparametric quadrilateral elements are used for modeling both the soil skeleton and pore water pressure. A parametric study was carried out and different parameters were changed to study their effects on the behavior of partially saturated soil. These parameters include the degree of saturation of the soil (S) and depth of water table. The study reveals that when the soil becomes partially saturated by dropping water table at different depths with different degrees of saturation, the bearing capacity of shallow foundation increases about (4 – 7) times higher than the bearing capacity of the same soil under saturated conditions. This result is attributed to matric suction value (i.e negative pore water pressure). The behavior of soil in partially saturated condition is like that of fully saturated condition but with smaller values of displacement. It is found that the settlement is reduced when the water table drops to a depth of 2 m (i.e. twice the foundation width) by about (92 %).


Article
Genetic Algorithm Optimization Model for Central Marches Restoration Flows with Different Water Quality Scenarios
نموذج الجينات الوراثية لايجاد الاطلاقات المطلوبة للجريان لانعاش الاهوار المركزية باستخدام عدة صيغ لنوعية المياه

Loading...
Loading...
Abstract

A Genetic Algorithm optimization model is used in this study to find the optimum flow values of the Tigris river branches near Ammara city, which their water is to be used for central marshes restoration after mixing in Maissan River. These tributaries are Al-Areed, Al-Bittera and Al-Majar Al-Kabeer Rivers. The aim of this model is to enhance the water quality in Maissan River, hence provide acceptable water quality for marsh restoration. The model is applied for different water quality change scenarios ,i.e. , 10%,20% increase in EC,TDS and BOD. The model output are the optimum flow values for the three rivers while, the input data are monthly flows(1994-2011),monthly water requirements and water quality parameters (EC, TDS, BOD, DO and pH).The objective function adopted in the optimization model is in a form the sum of difference in each of the 5 water quality parameters, resulting from the mixing equation of the waters of the rivers, from the accepted limits of these parameters , weighted by a penalty factor assigned for each water quality parameter according to its importance. The adopted acceptable limits are 1500,1000, 6,4 and 7, while the penalty factors are 1,0.8,0.8,0.8,and 0.2 for EC,TDS,BOD,DO,and pH respectively. The constraints adopted on the decision variables which the monthly flows of the three rivers are those that provide the monthly demands downstream each river, and not exceed a maximum monthly flow limits. The maximum flow limits adopted are for three flow cases, wet, average and dry years. For each flow case three scenarios for the monthly water quality parameters were adopted , the average values(scenario 1),the 10% increase in EC,TDS, and BOD (Scenario 2),and the 20% increase in these three water quality parameters (Scenario 3). Hence nine cases are adopted and for each an optimum monthly flows are found for each river. The genetic optimization model adopt a variable number of population of 100 to 1000 in a step of 100,0.8 and 0.2 cross over and mutation rates, and three iterations to reach the stable optimum solutions. The results indicates that the flow analysis shows a significant decrease in the flow values of the three rives after year 2000,hence, the flow values for the period of (1994-1999), are excluded and the only used values are those for (2000-2011). The estimated monthly demands exhibits low variation. The observed optimum monthly flow values decrease in general as the case flow changed from wet to normal and dry cases. The change in Scenarios from S1 to S2 and S3 , do not necessarily increase all the required optimum monthly flow values. The obtained minimum objective functions do not exhibits a certain trend with the change in the flow cases and/or the change in the scenarios.


Article
Design and Implementation of a Generalized N-Digit Binary-To-Decimal Converter on an FPGA Seven-Segment Display Using Verilog Hdl
تصميم وتنفيذ محول من التمثيل الرقمي الثنائي الى التمثيل الرقمي العشري المكون من سلسلة رقمية طولها (N) على شاشة العرض ذات السبع قطع لحيز البوابات المرتبة بهيئة صفوف القابلة للبرمجة (FPGA) باستخدام لغة وصف الأجهزة فيرلوغ (verilog)

Loading...
Loading...
Abstract

It is often needed to have circuits that can display the decimal representation of a binary number and specifically in this paper on a 7-segment display. In this paper a circuit that can display the decimal equivalent of an n-bit binary number is designed and it’s behavior is described using Verilog Hardware Descriptive Language (HDL). This HDL program is then used to configure an FPGA to implement the designed circuit.


Article
Numerical Study Of Heat Transfer In Cooling Passages Of Turbine Blade

Authors: Ahmed F. Khudheyer --- Hussein T. Dhaiban
Pages: 342-356
Loading...
Loading...
Abstract

As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary for safe operation. Cooling methods investigated in this computational study included cooling flow losses. Film-cooling is one typically used cooling method whereby coolant is supplied through holes passage, in present study the holes placed along the camber line of the blade. The subject of this paper is to evaluate the heat transfer that occur on the holes of blade through different blowing coolant rates. The cases of this study were performed in a low speed wind tunnel with two tip gap at small and large (0.03 and 0.09cm) and multiple coolant flow rates through the film-cooling holes. The blowing ratios was studied whereby coolant was injected from holes placed along the tip of a large scale blade model with Reynolds number (2.1 x 105) of the engine was matched. Results showed that baseline Nusselt numbers on the holes were reduced along the holes passage, and heat transfer coefficient is high values at iterance region. Overall, the cooling by holes appears to be a feasible method for prolonging blade life.


Article
Simulation of Longitudinal Stability Of Helicopter In Forward Flight
محاكاة الاستقرارية الطولية للهليكوبتر في الطيران الامامي

Loading...
Loading...
Abstract

The present work describes the development of code for trim and longitudinal stability analysis of a helicopter in forward flight. In general, particular use of these codes can be made for parametric investigation of the effects of the external and internal systems integrated to UH-60 helicopters. A forward flight longitudinal dynamic stability code is also developed in the work to solve the longitudinal part of the whole coupled matrix of equations of motion of a helicopter in forward flight. The coupling is eliminated by linearization. The trim analysis results are used as inputs to the dynamic stability code. The forward flight stability code is applied to UH-60 helicopter.


Article
Effect of Hydrated Lime on the Properties of Roller Compacted Concrete

Loading...
Loading...
Abstract

Roller compacted concrete (RCC) is a concrete of no slump, no reinforcement, no finishing, and compacted using vibratory roller. When compared with conventional concrete, it contains less water content when compared to traditional concrete. The RCC technique achieves significant time and cost savings during the construction of concrete. This study demonstrates the preparation of RCC slab of (38 ×38× 10) cm samples by using roller compactor which is manufactured in local markets. The Hydrated lime additive is used to study the mechanical and physical properties of that RCC slab samples. This investigation is divided into two main stages: The First stage consists of hammer compaction method with two gradation of aggregate, dense and gap graded aggregate, using five percentages of cement content (10, 12, 14, 16, and 18) as a percentage of the total aggregate content. This stage is carried out for selecting the maximum dry density, optimum moisture content, and optimum cement content which is utilized in RCC slab samples construction, a total of 49 cylinder samples sized (10 cm diameter and 11.6 cm high) are prepared. The Second stage is classified into two sub stages; the first one consists of constructing RCC slab samples using roller compaction, 12% cement as a percentage of total aggregate weight has been used according to the data obtained from first stage, this group presents reference mixes without additives. While the second sub stage presents RCC mix with hydrated lime additive and with the same gradation of mixes compact by hammer compaction method, hydrated lime was implemented as (5, 10, 12, and 15) percentage as a partial replacement of cement content. Both of physical and mechanical properties of RCC are studied using cores, sawed cubes, and sawed beams obtained from RCC slab samples. The properties studied were porosity, absorption, and compressive strength, splitting tensile strength and flexural strength by using third point loading method. The results show that hydrated lime improved the overall properties of RCC as compared to reference mix. Mixes with 5% lime give the optimum values for most of strength properties. Dense graded mixes with hydrated lime show superior properties as compared to gap graded mixes.


Article
Behaviour of Fire Exposed Reinforced Concrete Rigid Beams with Restrained Ends
سلوك الاعتلب الخرسانية الجاسئة والمقيدة النهايات تحت تأثير لهب النار المباشر

Loading...
Loading...
Abstract

This paper is devoted to investigate the effect of burning by fire flame on the behavior and load carrying capacity of rectangular reinforced concrete rigid beams. Reduced scale beam models (which are believed to resemble as much as possible field conditions) were suggested. Five end restrained beam specimens were cast and tested. The specimens were subjected to fire flame temperatures ranging from (25-750) ºC at age of 60 days, two temperature levels of 400ºC and 750ºC were chosen with exposure duration of 1.5 hour. The cast rectangular reinforced concrete beam (2250×375×375 mm) (length× width× height respectively) were subjected to fire. Results indicate remarkable reduction in the ultrasonic pulse velocity and rebound number of the rigid beams after cooled in water were (2-5 %) more than rigid beam specimens cooled in air. Load-deflection curves indicate deleterious response to the fire exposure. Also, it was noticed that the maximum crack width increases with increasing fire temperature.


Article
Theoretical and Experimental Investigation of Fluidic Oscillator

Loading...
Loading...
Abstract

A symmetric feedback fluidic oscillator design is proposed. Theoretical and experimental studies have been conducted to evaluate the relation between the fluidic feedback oscillator frequency and temperature of the air which is the working substance. Two methods of calculations were used, lumped and distributed parameter system. Then the results obtained experimentally. It was found that the results of the lumped parameter system are closer to experimental results than the distributed parameter system and also give the nonlinearity by (0.915%) between the lumped and experimental results show linear relationship between air temperature and oscillator frequency with a coefficient of determination (0.9977) And also found that the oscillator readings have a margin of error very small amount (0.0011 Hz / Co) as well as a percentage (hysteresis) of about (1.663%) when measuring the temperature and to overcome the hysteresis we suggest the use of fins to get rid of (residual heat), the rig sensitivity was (3.66*10-3 s/Co) finally, the rig resolution was (0.002 s).


Article
Visual pollution and statistical determination in some of Karrada district main streets /Baghdad

Loading...
Loading...
Abstract

This study objective is to identify the visual pollution in Karrada district main streets as an example of main streets in Baghdad, the public opinion about each pollutants, solutions to reduce and eliminate the pollution were suggested as well. In order to accomplish this objective different methods were used, 16 pollutants were selected, pictures of each pollutants were taken and a questioner were distributed randomly for 270 people to evaluate the public opinion with statistical methods. Garbage, their disposal and storage areas took the first two places as the highest offensive pollutants. The people showed that they find long lines of vehicles, debris and generators appearance ranked third, fourth and fifth respectively .This research showed that more than 70 percent of people are against the militarization of society and they consider any existence of heavy military machinery or personal is highly offensive issue. Other pollutants such as street sellers, beggars, and crossed wires considered as moderately offensive. Car parking in inappropriate places, badly trimmed trees, large billboards in the streets and the buildings criteria considered slightly offensive. The shops billboards and cellular phone and internet towers were considered the least offensive pollutants. Major solutions is to enhance the municipality management in both planning and operation methods relayed to pollution removal, running awareness campaigns to educate the people about the visual pollution effects and how to reduce it and reduce the military appearances in the city .

Table of content: volume: issue: