ISSN: 1999-8716

Volume 4, Issue 2

Volume 4, Issue 2, Autumn 2011, Page 1-165


ESTIMATION OF (Nγ) FOR STRIP AND CIRCULAR FOOTINGS USING THE METHOD OF CHARACTERISTICS

Lamyaa Najah Snodi

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 1-11

ABSTRACT:- By using the method of characteristics (commonly referred to as the slip line method), the values of the bearing capacity factor Nγ were computed for rigid surface strip and circular footings with smooth and rough bases. The analyses of bearing capacity for vertically loaded footings using the method of characteristics have been implemented in the publicly available computer program ABC, then Nγ –values were calculated theoretically. The supporting soil is modeled as a frictional Mohr – Coulomb material. For both footings, the value of the bearing capacity factor Nγ was found to increases significantly with an increase in the angle of internal friction. When friction angle of soil  ≤25, the computed values of Nγ for circular footing were found to smaller than those for strip footing and for larger values of , the magnitude of Nγ for circular footing were greater than those for strip footing for both smooth and rough base of footings. On the other hand, the magnitude of Nγ for rough footings was seen be higher than for a footings with smooth base. The obtained results were compared with those available in the literature, and reasonable agreements were observed.
Keywords: Bearing capacity, method of characteristics, circular footings, strip footing.

Study of Efficiency Performance of the precast Building Practical Research on Civil Eng. Dept. building - University of Tikrit

Maysoon Mohee

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 1-22

The precast building is A type of building which consist of many units mode were made in the factories previously and to accumulate in the site. The item (previously made) refer to precast building which consist of made units separate in the factories then to accumulate these units with other units.
The objective of research to deals with the Iraqi experiment in the precast which including carry out number of precast building and to create factories for this purpose in Baghdad and other governorates.
The problem of research is to decrease knolwdgement about precast building which represent support building system for normal modes of buliding.
The assumption of research there is effecting between design precast and quickly complete according to flexibility of design and external shape.
The application of research is study efficiency performance Iraqi experiment in civil engineering building in college of engineering in tikrit university. The building evaluate according to structural properties, dimension and characteristics of spaces by distribution forms and collection the data of random sample. The forms are distribute in to workers who carry out the building and the users of the building.

PREDICTION OF PHYSICAL & THERMODYNAMICAL PROPERTIES FOR BINARY SYSTEMS USING EQUATION OF STATE

Karima M. Putrus

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 12-28

ABSTRACT:- A single equation of state (EOS) such as Soave – Redlich Kwong EOS can accurately describe both the liquid and vapour phase, therefore it is used for binary systems to predict some physical and thermodynamical properties. Two methods, which are Soave- Redlich Kwong and Generalized Compressibility Factor Correlation are compared and adopted for the cubic equation of state to calculate molar volume, density, viscosity, thermal conductivity, specific heat and compressibility factor.
In this paper a computer program is developed requiring critical properties to perform these calculations. The results are compared with some available literature data, and we find that the computer programs are shown to be adequately reliable for this purpose, with deviation in some properties equal to (3.6%) as other predictive programs and procedures. Also from this comparison we notice that the Generalized Compressibility Factor Correlation method is better and more general than the Soave- Redlich Kwong.
Keywords: equation of state; prediction of physical & thermodynamic properties; binary mixtures.

Using of Matlab/Simulink ProgramIn Study of Speed Control Methods of D.C Motors

Tahssen Ali Uassen

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 23-36

This research aims to use (Matlab/Simulink) program in study of speed control methods of D.C motors within controlled by (field resistance, armature voltage, and armature resistance) to find their characteristics theoreticallu, then compre with practical. Finally two questioners were organized, the first for intended students, while the second for the experts in order to evaluate and to find the range of this research has achieved its aims.

AN EFFICIENT REARRANGEMENT OF DATA FOR GRAY IMAGE COMPRESSION BASED ON WAVELET TRANSFORM

Hussain F. Mahdi

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 29-38

ABSTRACT :- In this paper a new method is a proposed for gray image compression based on re-ordering the data of image before applying a wavelet transform. The advantage of converting the color image into luminance-chrominance color space is that the luminance and chrominance components are very much decorrelated between each other. Moreover, the chrominance signals contain much redundant information and can easily be subsampled without sacrificing any visual quality for the reconstructed image
In this paper a rearrangement of the gray image data is done by dividing it into three components (similar the RGB components of the color image) and convert color space from RGB to YCbCr (Y: luminance, Cb chrominance/blue, and Cr is chrominance/red) then apply wavelet transform. This method can return information more than wavelet method therefore very good result and high PSNR are obtained when it is compared with wavelet transform.
Keywords: Discrete wavelet transform (DWT), Gray image, YCbCr.

Effect of the Parameters of Electric Discharge machining On the Recast Layer Thickness.

Mustafa Ahmed Rijab

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 37-46

Results have indicated that recast layer thickness increases with pulse duration increase ,As for dielectric pressure ,it was found that as it increases up to 150 MPa Carbide removal rate increases , While recast layer thickness decrease ,as a result. However, further increase of dielectric pressure to 250 MPa causes recast layer thickness increase.
Results regarding electrode tip radius showed that as radius increases carbide removal is increased. As for tip angle for carbide GT30 results have indicated that increasing the angle causes an increase of recast layer thickness.

PROCESS SIMULATION STUDY OF ETHYL ACETATE REACTIVE DISTILLATION COLUMN BY HYSYS® 3.2 SIMULATOR

Ahmed D. Wiheeb

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 39-56

ABSTRACT:- In this paper, reactive distillation column for the production of ethyl acetate from ethanol and acetic acid has been simulated by the simulator tool of HYSYS. This reactive distillation is a promising operation whereby reaction and separation take place within a single distillation column.
The thermodynamic properties are calculated with the Wilson, NTRL and UNIQUAC Property Package models which are available in HYSYS simulator program.
The effects of water content in feed, bottom temperature and reflux ratio on top temperature and conversion of ethanol are studied when using three thermodynamic models and three feed statuses (upper, intermediate and spilt).
The results showed that the best conditions are: bottom temperature (83-86)0C, reflux ratio (2-5) without water content in feed at spilt condition using Wilson as the best model. The study gives evidence about a successful simulation with HYSYS because the results are close with the experimental data of (Calvar et al)[18].
Keywords: HYSYS Simulator, Reactive Distillation, Esterification processes, Ethyl Acetate production.

Metaphor Semantic in Architecture

Haider Jasim Essa

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 47-64

Architecture is the text that displays to receiver and architect, equally. The former (Receiver) try to translate that it while the latter (Architect) try to put the text in explainable form, in accordance to numbers of indicators that have semantic charecters.So architect have to put an indicators signs inside the architectural act. The important factor for study the architectural phenomena is that; how the architectural phenomena participate; itself or with its context, in the symbolic system of community that read and produces of its symbolic system. Architecture is made by human that rediscover through all time and place, and their studied variably depended on the reader, on what semantic have from indicators can interpreted by community even these architecture delivered at or prior to community who read it. The study of semantic and its pictures in architectural act give a database for understanding the architecture and which indicator should use for architecture maker. The research has shown four terms from semantic:

- Symbol
- Sign.
- Index.
- Icon.
Using of these semantic forms depends on architect vision, design environment, function of design and what’s position in urban context and society.

COMPUTER PROGRAM TO PREDICT PERFORMANCE OF FAST RUNNING HORIZONTAL AXIS WIND TURBINE TO REACHING THE OPTIMUM DESIGN

Nazar Muneam Mahmood

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 57-71

ABSTRACT:- A computer program in visual basic was designed to predict the performance of fast running horizontal axis wind turbine for electricity generation by using blade element theory and momentum theory. NACA 4415 was chosen for the aerofoil section of blade. the design parameters ( design tip speed ratio , rotor radius and blade number ) represented in scroll bars was designed in visual basic, and by changing these parameters , solidity, chord line and twist angle curves along the blade, in addition to the rotor performance curve (relation of power coefficient with tip speed ratio), will be draw instantly.
The numerical integration (trapezoidal method) was used to compute the area under rotor performance curve, the program will record the value of this area, and by change parameter design and by knowing the maximum value of area, we will know the optimal design for turbine rotor.
The three and four rotor blades and the values of design tip speed ratio between (5 - 9) give the best performance of rotor. The effect change of rotor radius on performance rotor was found very small, and there is no noticed effect to rated wind speed on rotor performance when changing parameter design in computer program.
Keywords: wind rotor, wind turbine, fast running HAWT, optimum design, performance prediction method, NACA 4415.

A PROPOSED ESTIMATOR FOR A DIRECT TORQUE CONTROL OF INDUCTION MOTOR BY USING RADIAL BASIS FUNCTION NEURAL NETWORK TECHNIQUE

Mohammed Khalaf Masood

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 72-85

The purpose of this paper is to use Radial Basis Function Neural Network (RBFNN) as an estimator for stator flux and electromagnetic torque in Direct Torque Control (DTC) systems used as a driver of a 3-phase induction motor, in order to reduce the ripples in the output torque. This paper includes design, construction and training for three different modes of operation of RBFNN, in which the spread constant has a different value for each estimated parameter during the network training. Then, the network, which has independent outputs, gives the best results choused as an estimator in the proposed DTC system. Matlab/neural network toolbox used for training the proposed estimator at different load torques.
The Simulation results are obtained using program of Matlab/Simulink. The coincidence of the values of the output data obtained from the proposed estimator and that from the conventional one proves the proposed system accuracy.

CATALYTIC REFORMING OF HEAVY NAPHTHA,ANALYSIS AND SIMULATION

Zaidoon M. Shakoor

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 86-104

In this paper, one-dimensional steady-state mathematical model of a semi regenerative naphtha catalytic reforming process had been made. This model incorporated a detailed kinetic model involving 24 components, 1 to 11 carbon atoms for paraffins (n and iso) and 6 to 11 carbon atom for naphthenes and aromatics with 71 reactions. The effect of pressure drop was considered through Ergun equation. The model explains the composition, temperature and pressure distributions along the four reforming reactors.
The simulation results of the proposed model were compared with the experimental results obtained from literature to validate the model.
The results showed good agreement between the reformate composition of proposed model with the experimental reformate composition.
Finally, the mathematical model was used to study the effect of reactor feed temperature, total pressure and hydrogen to hydrocarbon feed ratio on the reformate compositions.

STUDY THE SYMMETRIC- PLASTIC DEFORMATION MECHANISM OF CIRCULAR SHEETS IN CYLINDRICAL DIE

Sameer Dawood Ali

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 105-117

In this study a numerical procedure was proposed for the design of deep drawing process using finite element method (F.E.M) through program code (ANSYS 11) simplified 2-D ax symmetric model of conical cup are been developed. This research thoroughly investigates the axsymmetric deformation mechanism to evaluating the formability of sheet metals and to study the effect of some parameters which influence the drawing process such as: Die geometries, friction coefficient, It reveals how plastic regions in a work piece appear and spread and how they vary with punch diameter and also shows the distributions of strains , internal forces and proposes approximate model for engineers than analyses the deformation of such work pieces and evaluate the formability of metal materials. The prediction of the plastic wrinkling of a sheet during forming operation in the experimental study is a good agreement with the present numerical analyses are carried out for work pieces of thicknesses 1.5 mm and 2 mm with diameters 120 mm and 150 mm respectively, The diameters of cylindrical punches are 45 mm and 65 mm respectively, using Ansys 11 program which was recently developed and has good prospects for engineering applications.

BEARING CAPACITY BASED ON SPT-COMPUTER INTERPOLATION

Khattab Saleem AbdulRazzaq

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 118-129

Any structural design must be accompanied with sound analysis referring to the foundation design. The columns carrying the total load of the building may be in very high stress. The actual stress that exists in columns may reach in actual cases to half f'c or more. On the other hand, the maximum carrying stress of soil is very much small compared with that for reinforced concrete, the situation that necessitate the enlargement of column end to have "a footing". While the compressive strength of concrete is easy to measure, the bearing stress of soil is not. Methods of evaluating the soil bearing capacity are numerous and consist of field and laboratory. The SPT is one of these field methods. Scientists tried to relate the SPT-N value with the soil strength properties resulting in large number of tables, charts, and graphs. This research considers the most famous methods to evaluate the bearing capacity from the SPT. A BASIC computer program is written to aid in using these formulas. In going to this step all tables, curves, and graphs must be converted to numerical equations. This is done by using the usual FD technique of interpolation. The authors feel that this program must be used with caution since it is not a replacement of sound hand calculations associated with engineering judgment and experience. This is because the very SPT is used only as a guide and never as a replacement of laboratory testing program except for sands since it is very difficult to get undisturbed samples.

AN APPRAISAL OF THE TRANSIENT RESPONSE OF A D.C. SHUMT MOTOR USING MATLAB/SIMULINK UNDER NO LOADING AND FULL LOADING CONDITIONS

Alia Jasim Mohammed

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 130-140

Electric machines are used to generate electrical power in power plants and provide mechanical work in industries.
This paper describes the MATLAB/SIMULINK realization of the performance of a D.C. shunt motor and introduces model power components to use computer simulation as a tool for conducting transient by using Simulink and SimPower System. These simulation models were employed to calculate the speed (N), torque (T), armature current (Ia), input and output power (Pin and Pout), losses (Plosses) and efficiency (η) for the motor at no load and load conditions. The results obtained using MATLAB were compared with the practical results, the ratio of error is about (1-2) % was found. The SIMULINK was written in MATLAB languages version (6.5).

DESIGN OF A SOFTWARE SYSTEM FOR FINITE STATE MACHINE (FSM)

Hussein Abdulameer Abdulkadhim

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 141-149

There are several ways used to represent the circuits and system operations for design and analyses. Finite state machine (FSM) is one of the ways that used for representing the operations of many circuits and systems in electronic engineering, computer engineering ,..etc by graph. Finite state machine is very simple machine in design. It consists of sets of input symbols, output symbols and states that required to design it. Also, in fact, the function of input symbols and output symbols with the present state to give the next state must be found. In this paper, a software simulator is implemented by using Visual Basic programming language to simulate the Finite State machine (design and operation). This simulation represents general examples. However, the software may be used to learn the student concepts of FSM and its operations.

MATHEMATICAL MODEL FOR THE STUDY EFFECTS OF METEOROLOGICAL CONDITIONS ON DISPERSION OF POLLUTANTS IN AIR

Anaam A. Sabri

DIYALA JOURNAL OF ENGINEERING SCIENCES, Volume 4, Issue 2, Pages 150-165

The purpose of the present work was to investigate air quality that contained pollutant gases (SO2 , NO2 , CO) released from the thermal power plant as case study. Gaussian Plume Model and the computer program (visual basic 6) is used to calculate concentrations dispersion of gas pollutants at different meteorological conditions (wind speed, ambient temperature); maximum concentration values, downwind distance and required effective stack height estimation.
A typical theoretical investigation of a case study concerning existing air pollution problems at an industrial area (4Km) downwind distance by using the computer program. The results showed that the concentration of SO2 (890 µg/m3) released from stack may is higher than the EPA standard. Also the optimum point of the ground level concentration of pollutants decreases with increasing effective stack height.