ISSN: 1999-8716

Volume 7, Issue 1

Volume 7, Issue 1, Winter 2014, Page 1-134


NUMERICAL STUDY ON EFFECT OF A SUSPENDED BOULDER IN SOIL MATRIX ON A DOMESTIC FOUNDATION

Waad Abdulsattar Zakaria

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 1-15

Here in this study it is assumed that an undetected large size boulder, has a sharp edge and projecting upwards making a “point force or a point reaction,” and exists directly under domestic footing. The beam on elastic foundation (Hetenyi-solution, 1946) will change to different spring constants reflecting soil and boulder strength properties, and in this way the problem is analyzed numerically in FE method using STAAD-Pro/2004 program. The usual stresses and strains existing in concrete footing will eventually change, the case which this study may show. In other words, the study is concerned in the stress distribution in soil with the presence of boulder and in modeling it into the FE method as spring forces, and how these induced forces will change the stresses and strains in the footing concrete by comparing it with the case of non-boulder existence. The integrity of footing is noticed to see how much domestic footing is close to jeopardy. It is concluded that there is high increase in stress over the designed one if there exists a boulder rock underneath footing. In extreme cases these percent stress increase will eventually exceed 100%.

STRUCTURAL PERFORMANCE EVALUATION OF THE DIYALA CITY PROJECTS USING THE METHOD OF MULTIPLE CRITERIA COMPLEX PROPORTIONAL ASSESSMENT OF ALTERNATIVES WITH GREY RELATIONS (COPRAS-G)

Hafeth I. Naji

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 1-24

The construction sector the main driver of the national economy on the other hand is facing this sector stumbled in his performance and the advantage of the merger of several problems at the same time due to the complex nature and uncertain environment of the project and the multiplicity of factors that lead to the occurrence of a time delay in implementation and high cost of the project, and to address this challenges requires the project management methods in this area and the potential of a smart and distinctive in making the right decisions. The method of multiple criteria complex proportional assessment of alternatives with Grey relations (COPRAS-G) is one of those methods. This research focuses on providing (COPRAS-G) technique helps to make the best decisions when setting up the project, which encountered problems are complex and multi-criteria (MCDM). And apply this technique on a variety of areas as it allows the comprehensive study and non-biased criteria and alternatives. This research aims to highlight the importance of structural performance, and how it can be employed technical grounds (COPRAS-G) in assessing the structural performance of the Diyala City projects, through the identification of the criteria used to select the best project in terms of structural performance, and also to identify a list of projects the main province in order to choose the project optimization of this area. For the purpose of achieving the objective of research, has been collecting its own data from the literature that dealt with a multiple criteria complex proportional assessment of alternatives with Grey relations and, structural performance, and finally personal interviews of qualified designers and implementers of these projects. The results of data analysis for the sample showed that standards of cost, time, and quality is the most important criteria for bilateral comparisons between projects, and that the standard cost is more important than the rest of the criteria in the projects. Finally, and by calculating the relative importance of the projects and priorities of the alternatives and the utility degree have, we find that plant project streams Baquba has received the largest share of the benefit and importance compared with other projects.
In the end, was a set of conclusions and recommendations of the various aspects of the topic from, accelerate the application of techniques of decision-making multi-criteria in the evaluation of projects in addition to expediting the application of the proposed systems for Structural Performance by researchers to help corporate managers that the decision-making efficient, which will lead to a process control and more effective control on the construction project.

CPU SCHEDULING VISUALIZATION

Taqwa Flayyih Hasan

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 16-29

Scheduling is a key concept in computer multitasking and multiprocessing operating system design, and in real-time operating system design. CPU scheduling is the basis of multiprogramming operating systems by switching the CPU among process; the operating system can make the computer more productive, scheduling algorithms are widely used in communications networks and in operating systems to allocate resources to competing tasks. In this paper, visual interfaces for CPU scheduling algorithms were designed by using Visual Basic6 language. They may use to learn users about this algorithms and how they work.

STUDY TO DETERMINE THE LONGEST VALIDITY PERIOD FOR ORTHODONTIC WIRES IN A DIFFERENT ENVIRONMENTS

Mohammed Abdulateef Ahmed

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 25-38

The research summary to knowing longest period of validity for orthodontic wires in four corrosive media ,the first medium approximately similar to human mouth such as corrosive medium (Artificial Saliva), human body temperature, hydrogen power (pH), and aeration ,and compared with orthodontic wires these serve in same corrosive medium but at room temperature and the identical aeration as a second corrosive medium, and compared to orthodontic wires present or attending in sodium chloride solution instead of artificial saliva at room temperature and the like aeration as a third corrosive medium. The final comparison test with orthodontic wires present in sodium chloride solution at human body temperature and the like aeration too.
The study done by using device or system was native designed and manufactured according to modified American standard specification (ASTM G31), the orthodontic wires were from type austenitic stainless steel (301).
After four mentioned corrosion experiments for serial six months period ,and usage Corrosion Penetration Rate law (CPR) and by traditional mathematical methods addition to the microstructures of samples before and after corrosion experiments ,conclude that ;the longest validity period for orthodontic wires at environment approximately similar to human mouth ,then wires worked in artificial saliva at room temperature, followed by the wires served in sodium chloride solution at room temperature, finally; orthodontic wires were worked in sodium chloride solution at human body temperature had shortest validity period.

HOLE DRILLING IN POLYMETHYL METHACRYLATE (PMMA) USING CO2 LASER

Rana M. Taha

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 30-39

Laser sources are used in a large variety of applications for material processing. It is mainly used for welding, cutting, drilling, laser annealing, etc. This study narrows the scope down to one of the process, namely, laser drilling.
The hole depth, width and penetration velocity of evaporation depend on different parameters such as power, material, exposure time, distance between drilling tool and the material, the drilling tool, etc. In this paper; the laser beam was used as drilling tool. 16W CO2 laser (10.6µm) and transparent Perspex (PMMA) which is the abbreviation of polymethyl methacrylate work piece with 8mm thickness were used. The distance between laser beam and the material was 5cm. Different powers for CO2 laser were used for different exposure time. Hole depth, time required for boiling, heat flow per unit area and penetration velocity of evaporation were calculated. Measured and calculated results were approximately the same. Many figures which representing the relations between laser power, time to reach boiling, hole width, hole depth and exposure time were obtained by using Matlab 2008 software program.

ACCURACY IN THE PRODUCTION PLANNING OF THE CEMENT QUANTITY IN THE STATE COMPANY FOR CEMENT –TEST STUDY FOR THE FORECASTING METHODS BY USING ERRORS CRITERIA

Zainab Allawi Ibrahim

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 39-59

Planning the cement industry is important process because the cement is the major material in all building & industrial projects, many studies are prepared for improvement & advancement this industry
In this research, researcher study the cement production planning by test three forecasting quantitative methods; this test done by using the win QSB Software & Excel programming to predict the future quantity of cement to period 2015 & analyzing the forecasting results to measures the method accuracy by using errors criteria (MSE, MAPE, MAD) to choose forecasting method that give min. errors to depends on in planning of the cement production quantity. The results show that the best method to forecast the cement production quantity as follow; moving average for Fallujah & alkiam factory, in the weight moving average for kabesa factory, exponential for Kirkuk factory.

EVALUATION OF NEW HYPOTHETICAL CONCEPT (LHSIR) FOR DIE PROFILE DESIGN FOR HYDROSTATIC EXTRUSION OF Al/Mg COMPOUND

Muhsin J. Jweeg; Moneer H. Tolephih Al-Saady; Abdullah Dhayea Assi

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 40-60

This paper presents, for the first time, a new developed concept for design of Die pass profile used in hydrostatic-extrusion of Al/Mg compound. The new design criteria proposes a "Linearity" of the Homogeneous Successive Strain Increment Ratios (LHSIR) of the deformed material, instead of the "Constancy" concept (CHSIR) found in literature, as the tool base to generate the profile. The developed profiles were evaluated numerically to assess their relative pressure ratios as the main parameter for performance checking adopting the well-known Upper Bound Approach (UBA). A further developed aspect for the velocity field proposition is successfully made to carry out the necessary tedious computations. 12 different samples of commercial tool steel were CNC-manufactured, heat treated and tested to Al/Mg compound, from lead alloy, for sake of comparison and validity assessment. The major conclusion comes out of this work claims that a small variance in the classical constancy criteria of the Die design is very sensitive to change the expected levels of the relative pressure ratios of the extrusion process.

NUMERICAL STUDY OF STEADY NATURAL CONVECTION FLOW IN A PRISMATIC ENCLOSURE WITH STRIP HEATER ON BOTTOM WALL USING FLEXPDE

Sana Jaafar Yaseen

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 61-80

Laminar natural convection in two-dimensional Prismatic enclosure is studied and analysis numerically. For the enclosure top inclined walls are considered at low temperature, two vertical walls are adiabatic and strip heater at constant high temperature mounted on the bottom enclosure, while the reminder bottom wall kept at low known temperature. The partial differential equations for two dimensional conservation of mass, momentum and energy are solved using finite element software package (FLEXPDE.5). For Rayleigh number varying from 103 to 105 and for constant Prandtal number Pr=0.7 the change in temperature and flow fields (stream functions) were investigated for different heater locations and for different number of heaters. The effect of the number and locations of the strip heaters on local and mean Nusslet number were examined. Results were presented by streamlines, isotherms and Nusselt number and it indicates that the Nusselt number is significantly affected by increasing both Ra and number of heaters. A comparison of the streamlines, isotherms curves and average Nusselt at the same boundary conditions was made with that obtained by Tanmay et al.(7), and showed a good agreement.

SECONDARY ARC EXTINCTION IN EXTRA HIGH VOLTAGE SYSTEMS USING GROUNDING SWITCHES

Qais M. Alias; Wafaa F. Tobia

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 81-93

Long Extra High Voltage (EHV) transmission systems tend to bring a pronounced state of secondary arcing. Therefore, an essential pre-requisite for single-phase-switching application, is the possibility and speed of secondary arc final extinction during suitably short dead-time. During the past several decades, many techniques had been proposed and implemented in order to ensure fast secondary arc extinction. Among these was the use of High Speed Grounding Switches (HSGS’s). In such technique, the faulted phase is grounded via special switches; one at each end of the EHV line after the fault is cleared by both line ends circuit breakers. The primary advantage of grounding the faulted phase is the reduction of the fault point recovery voltage to a very low value. This, coupled with the circulation of opposite loop currents in the fault path, reduces the secondary arc current and lead to a fast secondary arc extinction. A sample 500kV, 300km transmission system equipped with High Speed Grounding Switches is modeled as a test system. The modified Fourier transform is used to calculate the system response through, fault, fault clearance, HSGS’s operation, and line restoration. The non-linearity of the secondary arcing state is also accounted for. The paper concludes with a presentation of some computational results related to the above mentioned EHV system showing that HSGS’s greatly improves the single-phase-switching performance.

EFFECT OF ADING NANOCARBON BLACK ON THE MECHANICAL PROPERTIES OF EPOXY

Amer Hameed Majeed; Mohammed S. Hamza; Hayder Raheem Kareem

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 94-108

The study covers the effect of nanocarbon black particles (N220) on some important mechanical properties of epoxy reinforced with it [carbon black nanoparticles]. The nanocomposites were prepared with (1 to 10 wt. %) of carbon black nanoparticles using ultrasonic wave bath machine dispersion method. The results had shown that the tensile strength , tensile modulus of elasticity, flexural strength and impact strength are improved by (24.02%,7.93%,17.3% and 6% ) respectively at 2wt % .The compressive strength and hardness are improved by (44.4%, 12%) at 4wt%.

THE EFFECT OF COOLING RATE ON MECHANICAL PROPERTIES OF CARBON STEEL (St 35)

Jenan Mohammed Nagie

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 109-118

This paper is aimed to study the effect of cooling rate on mechanical properties of Steel 35. Specimens prepared to apply tensile, torsion, impact and hardness tests.
Many prepared specimens heat treated at (850ºC) for one hour and subsequently were cooled by three different media [Water-Air-furnace] to show the effect of Medias cooling rate on mechanical properties. Microstructures of all specimens examined before and after heat treatment by an optical microscopy.
To figure the phases obtained after heat treatment and its effect on the mechanical properties Experimental results have shown that the microstructure of steel can be changed and significantly improved by varying line cooling rate thus, improving one property will effect on the others because of the relationship between all properties.
In water media tensile, torsion and hardness improved while impact results reduced. Air media contributed in improving most of the mechanical properties because of grain size homogeneity. At furnace media ductility and impact improved.

COMPARING DESIGN QUALITY FOR SCHOOL BUILDINGS IN IRAQ

Wadhah Amer Hatem

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 7, Issue 1, Pages 119-134

Design quality has many definitions according to the field being considered. In the construction industry, the term design quality can be defined as the ideal design that satisfies all the project parties in terms of cost, time, and material specification and so on. Design quality measurement is considered from the point of view of complex tasks in the construction industry because of the differences in the stakeholders’ opinions regarding each item in the design such as whether is it safe, comfortable, attractive in style. etc. This paper compares the design quality of two types of school buildings in Iraq and uses the design quality indicator toolkit DQI which was developed by Gann et al. [1]. The results show that the design quality for the closed school building was superior to that of the U-shape building in many aspects.