A theoretical description is given for the ploughing of a work-hardening inclined surface by a hemispherical slider. As the indenture is moving horizontally, the grooving force and the depth of penetration are expressed for conditions that correspond to the climbing and descending asperities. Assuming a constant vertical load on the slider, the friction coefficient due to ploughing, FP, is shown to be affected by surface inclination moreover, the limiting value of FP when the vertical load on slider is made infinitely small is shown to be independent upon the asperity angle and the shape of the slider. The treatment has some use in predicting the extent of surface damage in contact profilometry, especially for soft materials in particula

In present paper, the derivation of stiffness matrix for a general two dimensional curved element in the global coordinates system is presented. The derivation depends on the assumption that any curved in-plane element can be approximated by a specified curve in polar coordinates. The polar curve assumed in this polar depends on some variables that enable it to represent any two dimensional curved element. The derivation process accompanied by complex integrals which are evaluated by using (Gaussian Quadrature) method of numerical integration. One numerical example is presented to verify the accuracy and efficiency of the derived stiffness matrix. Very good agreement is obtained between the results of the derived stiffness matrix and the

In this paper, several sliding friction formulations used in spur gear dynamics are examined and compared in terms of the predictions of interfacial friction forces and off-line-of-action. Computing friction formulations include Coulomb models with time-varying friction coefficients and empirical expressions based on elasto - hydrodynamic and/or boundary lubrication regime principles. Predicted results compare well with friction force measurements and appeared completely conformed with specific objectives of this paper are established as follows: (1) propose an improved MDOF spur gear pair model with time-varying coefficient of' friction, µ(t), given realistic mesh stiffness profiles.(2) comparatively evaluate alternate sliding friction

Free vibration solution will be developed for laminated simply supported closed cylindrical shells. This solution is obtained using General Third Shell Theory (G.T.T.). Also the critical in-plane fatigue load is studied and the required equilibrium equations are developed, the effects of tension or compression in-plane load on the natural frequencies are discussed also. The natural frequencies and in-plane fatigue load results are very close to those obtained by other researchers.

In order to design structures on soft soils, it is necessary to predict the behavior of the soft soil
under imposed structure load. The high excessive settlements of the soft soil can cause many
problems for the structures built on the soil like cracking and breakup of pavements, railway,
highway embankments, etc...
In this work, the finite element method is utilized as a tool for carrying out different
analyses of embankments on soft ground with different conditions. The computer program CRISP
(CRItical State Program) is developed to suit the problem requirements. CRISP uses the finite
element technique and allows predictions to be made of soil deformations using the critical state
theory.
Eight-node isoparame

This paper is aiming to develop a numerical procedure using the finite element method for the
analysis of soil consolidation by taking into consideration the loading and unloading cycles with
particular emphases on the pore pressure built up. The study is concerned with trapezoidal cyclic
loading. The shear stresses that are developed in the subsoil due to cyclic loading cause shear strains
and change in the mean normal stresses due to distortion of soil element. Biot’s consolidation theory
that adopted in this study may be able to take these changes into consideration. The results indicated
that the excess pore water pressure increases with load cycles and finally, a steady state conditions are
reached. This may b

Kerberos system is a powerful and widely implemented authentication system. Despite this fact it has several problems such as the vulnerability to dictionary attacks which is solved with the use of public key cryptography. Also an important security feature that is not found in Kerberos is perfect forward secrecy. In this work the lack of this feature is investigated in Kerberos in its original version. Also a public key based modification to Kerberos is presented and it is shown that it lacks the prefect forward secrecy too. Then some extensions are proposed to achieve this feature. The extensions are based on public key concepts (Diffie-Hellman) with the condition of keeping the password based authentication; this requires little modif

Oil refineries are major contributors to local environmental problems .The main pollutants are oil , dissolved components , spent acids , suspended solids, sludge . Technically it is possible to remove all these pollutants by Physical , chemical and biological means .Oil is initially removed in the (API) separators , by skimming, while the heavy particles by scrapping . Further removal of discrete particles is done by gravity settlement in the primary settlement tank .The remaining suspended matter is removed by chemicals , that are added in the flocculation tank , while further flocs are removed in the air flotation tank . The biological treatment follows to remove the biological pollutants , usually followed by secondary settlement to

The work in this research presents an experimental and a theoretical study to obtain the effect of using a low permeability geosynthetic material on the longitudinal and lateral coefficients of dispersion. This would have its effect on the contaminants migration through an isotropic, homogenous and saturated soil. The first stage of this research involves the study of the geosynthetic material and in calculating the longitudinal and lateral coefficients of dispersion for an Iraqi sandy soil by using an experimental set-up to simulate the processes. To investigate the effect of using a geosynethtic material on the dispersion coefficients, the test was conducted for each velocity that was used in the experimental work and as follows: wi

Due to the deterioration of water quality within the last few years because of the increase of water consumption and the waste water production and disposal into the river The water quality in both surface and ground water resources was negatively affected .The concept of water quality index is used as a tool for water quality classification in Tigris River within Baghdad City .Twenty two parameters of pollution were selected to measure the water quality indices of Tigris river within Baghdad city .Those parameters were measured during (2000-2004)as average monthly values ,three water treatment plants were selected out of the eight water
treatment plants that exist along the river.Al Kharkh water treatment plant to reflect the water

Porcelanite rocks were selected to be the dual media with sand in this study to improve the performance of the filtration process in water treatment plants. The work required installing a pilot filtration unit in the location of the filters in one of the water treatment plants, so the experimental work was performed on the same influent water of the filters in the plant (the effluent from the sedimentation tank. The pilot filtration consists of three plastic column filters, working parallel and simultaneously. The first contains 70 cm sand (the same type used in the filters of the plant), the second and third were dual filters (porcelanite with sand) of different depths and sizes using different filtration rates (5, 10, and 15 m/hr). The

Traditional methods of dealing with finding the relationship between the inputs data of simulation models and the outputs data fail or takes a long time to find this relationship. Artificial neural networks (ANNs) have the ability to learn complex relationships between inputs and outputs. Their use can greatly enhance simulation models and allow for more accurate representations of real life scenarios.This paper is concerned with the application of the mechanism of integrating simulation models with artificial neural network (ANN) model. This mechanism was tested by integrating simulation models of re-tubing heat exchangers line (RTHEL) with ANN model to schedule entering exchangers to inside retubing workshop. The result of applying thi

Many useful softwares in projects management are available now. Ms Project and Primavera are some
examples of these softwares. Those programs need to be fed by information by the user. The users
usually collect this information from the project and design documents. This collection process needs
considerable time and efforts, and usually accompanied of some errors in data transfer process.
In order to reduce the required time and efforts and to eliminate individual errors in data transfer
process, an Integrated System is needed. This Integrated System can extract the graphical information
from an AutoCAD drawing and transfer it to a digital form suitable for processing in the project
management softwares such as Exce

The effect of considering the third dimension in mass concrete members on its cracking behavior is investigated in this study. The investigation includes thermal and structural analyses of mass concrete structures. From thermal analysis, the actual temperature distribution throughout the mass concrete body was obtained due to the generation of heat as a result of cement hydration in addition to the ambient circumstances. This was performed via solving the differential equations of heat conduction and convection using the finite element method. The finite element method was also implemented in the structural analysis adopting the concept of initial strain problem. Drying shrinkage volume changes were calculated using the procedure suggest

Specific surface has a very important role in geotacnic especially with that home dell with gypseous soils or other types of salty soils. Because its calculation need for high accuracy, a procedure is presented to calculate a correction factor for Specific surface determination.
In a previous work, grain size distribution curves of many soil samples are collected. A value for the specific surface of each soil is determined summing the surface area of subintervals in the distribution curve.
In this work, the values of specific surface are obtained from these gradation curves and compared to those calculated using the values of the equivalent diameter for each soil. Fitting has been made and gets the best equation representing these

The aim of reducing drag is to increase the flow efficiency by using the same pipes and pumps. As a result the amount of crude oil transported will increase without using new pipes and pumps.
In the present work, the effectiveness of two surfactants (Sodium dodecyl benzene sulfonate (SDBS) and Sodium lauryl sulfate (SLS)) are studied by using a closed loop system. This system consists of three pipes made from commercial steel, each one with different diameter (0.75, 1 and 1.5 inch). The length of each individual test section of the pipe is two meters. The experimental work is achieved under three different temperatures (30º, 40º and 50°C). The concentrations of both surfactants used are ranging between 50 to 300 weight ppm. Laborat

Fluorophosphate neodymium laser glass has been prepared by discontinuous melting technique.
Special melting and casting conditions were followed to prevent devitrification of glass samples.
Furnace melting followed by slow cooling resulted formation of non vitreous glass. Problems of
high viscosity melt and incomplete solubility and immiscibility of glass components were
encountered by adjusting composition of glass components. X-ray diffraction analysis of the
prepared glass samples proved the formation of amorphous phase. The prepared Nd – fluoride glass
has low refractive index which is an important parameter for high power laser application. Optical
properties of Nd – fluoride glass samples were investigated.

Based on the biological human models in defending human body against viruses, a new approach in designing the anti-virus system is introduced. This approach is called SDS( Self- Defence System). The principle of the SDS is that each executable program is responsible of defending itself against viral-attacks. In this system, each executable program is injected with basic anti-virus component which is called Self-Defence Routine. This routine, together with dedicated anti-virus loading program are used to construct the SDS which protects the computer system from virus invasion

Piezoelectric transducers have become increasingly popular in vibration control applications. They are used as sensors and as actuators in structural vibration control systems. They provide excellent actuation and sensing capabilities. In this paper, the term smart beam refers to a beam with a finite number of collocated piezoelectric actuator / sensor pairs. The proposed thin smart beam governing equation was derived by the same procedure that the Bernoulli-Euler equation derived but with some additional mathematical terms to be valid for describing the smart beam. The engineering control techniques were used to obtain the solution of the proposed differential equation for the simply supported beam where with some auxiliary equations an

In this work, numerical method approach has been used to simulate the solidification parameters
of an eutectic aluminum-silicon alloy in chilled metallic mould with copper. The approach is based on
the solution of heat flow equations of the casting and mould. In addition, the latent heat is treated as a
boundary condition between the liquid and solid phase. The results showed that different behaviors of
solidification parameters are obtained along the casting. Furthermore, the simulation approach of
solidification parameters in conjunction with the microstructure indicated that it is possible, to a large
degree, giving a knowledge about the microstructural features for any alloy system.

Consuming of by-product or waste materials in highway engineering is significant in the construction of new roads and/or in renovations of the existing ones. Pulverised Fuel ash (PFA), which is a by-product material of burning coal in power stations, is one of these materials that might be incorporated instead of mineral filler in hot asphalt mixtures.

Two types of surface course mixtures have been prepared one with conventional mineral filler i.e. ordinary Portland cement (OPC) while the second was with PFA. Several testings have been conducted to indicate the mechanical properties which were Marshall Stability and Indirect Tensile Strength tests. On the other hand, moisture damage and ageing have been evaluated

Quality control charts are limited to controlling one characteristic of a production process, and it needs a large amount of data to determine control limits to control the process. Another limitation of the traditional control chart is that it doesn’t deal with the vague data environment. The fuzzy control charts work with the uncertainty that exists in the data. Also, the fuzzy control charts investigate the random variations found between the samples. In modern industries, productivity is often of different designs and a small volume that depends on the market need for demand (short-run production) implemented in the same type of machines to the production units. In such cases, it is difficult to determine the contr

In data transmission a change in single bit in the received data may lead to miss understanding or a disaster. Each bit in the sent information has high priority especially with information such as the address of the receiver. The importance of error detection with each single change is a key issue in data transmission field.
The ordinary single parity detection method can detect odd number of errors efficiently, but fails with even number of errors. Other detection methods such as two-dimensional and checksum showed better results and failed to cope with the increasing number of errors.
Two novel methods were suggested to detect the binary bit change errors when transmitting data in a noisy media.Those methods were: 2D-Checksum me

 This study presents a reliable and effective idealization scheme for the free vibration analysis

of buried cylindrical storage tanks. The three dimensional problem is transformed into a two

dimensional one by using a semi analytical finite element procedure. Conical shell of

revolution element is used. to represent the cylindrical wall, top plate, and bottom plate of the

tank by an appropriate method. The Combined effect of structure-soil-fluid interaction is of

primary

 Fixed bed sorption processes such as adsorption and ion exchange do not operate at

steady state. The design equations are differential that usually require numerical methods

to solve. Thomas gives a general analytical solution for these equations. It is based on

second-order reaction kinetics and the assumption of Langmuir isotherm. Computer

program for the solution of Thomas model was designed using MATLAB 7.0. Four sets

of experimental data are tested to show the capab

 Removal of direct blue dye by electrocoagulation method has been investigated using aluminum

electrode in a bench-scale electrochemical system. Current density, NaCl concentration,

electrocoagulation time, and dye concentration has been studied as effecting parameters in color

removal efficiency. Increasing of current density will increase the color removal efficiency and

energy consumption as well. While increasing NaCl concentration increase the color removal

efficienc

 This study deals with thermal cyclic loading phenomena of plates which were fabricated from

composite materials (woven roving fiber glass + polyester) were exposed to (75 C°) temperature

gradient thermal shock for ten times in different stage of conditioning times due to the effect of thermal

fatigue using the method of Levy solution and compared these results with both results from

experimental published work and (ANSYS Ver. 9) program. A composite laminate plate with fiber

 This research studied forgeability of preheated billet of 25%GRPOM plastic through

closed die forging technique using spur gear design. The type of deformation was

discussed as well. This process had done after heating the billet and die assembly at

100oC to achieve complete gear shape taking into consideration testing the product to

insure no inside or outside defects with improvement in the mechanical properties.

 Film condensation of steam on a vertical tube is investigated numerically and experimentally,

in the present work. A mathematical model was set based on the basic conservation laws of mass

and energy, Nusselts analysis of film condensation, and empirical equations available in the

literature. Then, a simulation program in FORTRAN language was developed which simulates the

film condensation of steam on a vertical tube. A complete steam tables subprogram

 Experimental and numerical investigation has been under taken to study turbulent flow of air through duct using restriction in different shapes and positions for Reynolds numbers ranges of (8.2x104 → 5.6x104).The numerical approach used in this work is the finite volume method for solution of elliptic partial differential equation for the modeling of turbulent (k-) model as well as wall function concept near the wall which was used to take the turbulent effects into consideration have been employed.The experimental te