Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 217501 - 217530 of 5211129

Full-Text Articles in Entire DC Network

Optimal Machining Parameters For Achieving The Desired Surface Roughness In Turning Of Steel, Lb Abhang, M Hameedullah Apr 2025

Optimal Machining Parameters For Achieving The Desired Surface Roughness In Turning Of Steel, Lb Abhang, M Hameedullah

The Journal of Engineering Research

Due to the widespread use of highly automated machine tools in the metal cutting industry, manufacturing requires highly reliable models and methods for the prediction of output performance in the machining process. The prediction of optimal manufacturing conditions for good surface finish and dimensional accuracy plays a very important role in process planning. In the steel turning process the tool geometry and cutting conditions determine the time and cost of production which ultimately affect the quality of the final product. In the present work, experimental investigations have been conducted to determine the effect of the tool geometry (effective tool nose …

Go to article

Oxydehydrogenation Of Propane Over Vanadium Oxide Supported On Kieselguhr Or Mcm-41, By Jibril, A Atta, Sa Al-Dress, Mc Al-Kinany, Ha Al-Megren Apr 2025

Oxydehydrogenation Of Propane Over Vanadium Oxide Supported On Kieselguhr Or Mcm-41, By Jibril, A Atta, Sa Al-Dress, Mc Al-Kinany, Ha Al-Megren

The Journal of Engineering Research

Supported vanadium oxide (5 wt%) on either Kieselguhr or mesoporous MCM-41 was prepared using impregnation method and tested as a catalyst in propane oxidative dehydrogenation (POD). The catalyst samples were characterized using X-ray elemental analysis, Brunauer-Emmett-Teller (BET) physisorption, and Z-ray Photoelectron Spectroscopy (XPS). After impregnation, the catalyst surface area decreased compared with that of the support. More drastic decrease was observed in the case of MCM-41 (77%) than the Kieselguhr supported sample (48%). There are also different degrees of vanadium oxide-support interaction as reflected by the XPS result. Si-O binding energy of 531.5 eV was observed on MCM-41-supported sample compared …

Go to article

Dynamic Analysis And Vibration Of Beam Inside Annulus For Ultra Short-Radius Water Jet Drilling, T Pervez, Sa Al-Hiddabi, A Al-Yahmadi, Ac Seibi Apr 2025

Dynamic Analysis And Vibration Of Beam Inside Annulus For Ultra Short-Radius Water Jet Drilling, T Pervez, Sa Al-Hiddabi, A Al-Yahmadi, Ac Seibi

The Journal of Engineering Research

Conventional water-jet nozzle systems have been developed and partially used in the oil and gas industry to drill horizontal sidetracks. However, this technique still presents a few shortcomings associated with tube buckling and water jet sagging. Due to these problems, the drilled hole deviates from the desired path and does not reach the target reservoir. The issue becomes more complex due to the continuously moving boundaries representing the borehole profile, which is, in turn, governed by the nozzle dynamics. A mathematical model representing the dynamics of water jet drilling confined in a borehole along with drilling mud is developed to …

Go to article

Cfd Analysis Of Water Solitary Wave Reflection, K. Smida, H. Lamloumi, K. Maalel, Z. Hafsia Apr 2025

Cfd Analysis Of Water Solitary Wave Reflection, K. Smida, H. Lamloumi, K. Maalel, Z. Hafsia

The Journal of Engineering Research

A new numerical wave generation method is used to investigate the head-on collision of two solitary waves. The reflection at vertical wall of a solitary wave is also presented. The originality of this model, based on the Navier-Stokes equations, is the specification of an internal inlet velocity, defined as a source line within the computational domain for the generation of these non linear waves. This model was successfully implemented in the PHOENICS (Parabolic Hyperbolic Or Elliptic Numerical Integration Code Series) code. The collision of two counter-propagating solitary waves is similar to the interaction of a soliton with a vertical wall. …

Go to article

Complexity Analysis Of Industrial Organizations Based On A Perspective Of Systems Engineering Analysts, I. H. Garbie, A. A. Shikdar Apr 2025

Complexity Analysis Of Industrial Organizations Based On A Perspective Of Systems Engineering Analysts, I. H. Garbie, A. A. Shikdar

The Journal of Engineering Research

Complexity in industrial organizations became more difficult and complex to be solved and it needs more attention from academicians and technicians. For these reasons, complexity in industrial organizations represents a new challenge in the next decades. Until now, analysis of industrial organizations complexity is still remaining a research topic of immense international interest and they require reduction in their complexity. In this paper, analysis of complexity in industrial organizations is shown based on the perspective of systems engineering analyst. In this perspective, analysis of complexity was divided into different levels and these levels were defined as complexity levels. A framework …

Go to article

Prediction Of Hourly Solar Radiation On Horizontal And Inclined Surfaces For Muscat/Oman, N.Z. Al-Rawahi, Y.H. Zurigat, N.A. Al-Azri Apr 2025

Prediction Of Hourly Solar Radiation On Horizontal And Inclined Surfaces For Muscat/Oman, N.Z. Al-Rawahi, Y.H. Zurigat, N.A. Al-Azri

The Journal of Engineering Research

In this paper, hourly terrestrial radiation: direct beam, diffuse and global solar radiation are modelled and calculated based on daily measured data for a horizontal surface. In addition, the same parameters were modelled for inclined surfaces. Most of the parameters modelled in this work represent a part of the input data required by building thermal simulation and solar energy systems software. Important trends of the solar radiation on tilted surfaces as a function of time and direction are being presented and discussed. The comparison of some of the results with measured data from other sources shows good agreement. The effect …

Go to article

Load-Displacement Curves Of Spot Welded, Bonded, And Weld-Bonded Joints For Dissimilar Materials And Thickness, E.A. Al-Bahkali Apr 2025

Load-Displacement Curves Of Spot Welded, Bonded, And Weld-Bonded Joints For Dissimilar Materials And Thickness, E.A. Al-Bahkali

The Journal of Engineering Research

Three-dimensional finite element models of spot welded, bonded and weld-bonded joints are developed using ABAQUS software. Each model consists of two strips with dissimilar materials and thickness and is subjected to an axial loading. The bonded and weld-bonded joints have specific adhesive thickness. A detailed experimental plan to define many properties and quantities such as, the elastic - plastic properties, modulus of elasticity, fracture limit, and properties of the nugget and heat affected zones are carried out. Experiments include standard testing of the base metal, the adhesive, the nugget and heat affected zone. They also include employing the indentation techniques, …

Go to article

Flow Asymmetry In Symmetric Multiple Impinging Jets: A Large Eddy Simulation Approach, N. Kharoua, L. Khezzar Apr 2025

Flow Asymmetry In Symmetric Multiple Impinging Jets: A Large Eddy Simulation Approach, N. Kharoua, L. Khezzar

The Journal of Engineering Research

A numerical study on in-line arrays of multiple turbulent round impinging jets on a flat heated plate was conducted. The Large Eddy Simulation turbulence model was used to capture details of the instantaneous and mean flow fields. The Reynolds number, based on the jets diameter, was equal to 20,000. In addition to flow features known from single jets, the interaction between the neighboring jets was successfully elucidated. Symmetry boundary conditions were imposed to reduce the computational domain to only a quarter. In accordance with previous numerical and experimental works, the asymmetry in the velocity field near to the impingement plate …

Go to article

Transition Of Gas-Liquid Stratified Flow In Oil Transport Pipes, D. Lakehal, M. Labois, D. Caviezel, B. Belhouachi Apr 2025

Transition Of Gas-Liquid Stratified Flow In Oil Transport Pipes, D. Lakehal, M. Labois, D. Caviezel, B. Belhouachi

The Journal of Engineering Research

Large-Scale Simulation results of the transition of a gas-liquid stratified flow to slug flow regime in circular 3D oil transport pipes under turbulent flow conditions expressed. Free surface flow in the pipe is treated using the Level Set method. Turbulence is approached via the LES and VLES methodologies extended to interfacial two-phase flows. It is shown that only with the Level Set method the flow transition can be accurately predicted, better than with the two-fluid phase-average model. The transition from stratified to slug flow is found to be subsequent to the merging of the secondary wave modes created by the …

Go to article

Physics Of Breakup In Liquid Column And Sheet, M. Ali, M. Q. Islam, M. Khadem Apr 2025

Physics Of Breakup In Liquid Column And Sheet, M. Ali, M. Q. Islam, M. Khadem

The Journal of Engineering Research

The details on breakup processes of liquid column and sheet are numerically investigated to provide the physics of the capillary instabilities and formation of liquid drops. Two cases are used: A numerical analysis on the capillary instabilities and breakup processes of a cylindrical liquid column and a moving liquid sheet in a moving gaseous medium to analyze the dynamics and breakup of the liquid sheet. The problem, composed of the Navier-Stokes systems associated with surface tension forces, is solved by the Volume of Fluid (VOF) technique with a Continuum Surface Force (CSF) to artificially smooth the discontinuity present at the …

Go to article

Adaptive Compensator Of Single State Elastoplastic Friction Model, A. A. Abouelsoud, J. Abdo, R. Zaier Apr 2025

Adaptive Compensator Of Single State Elastoplastic Friction Model, A. A. Abouelsoud, J. Abdo, R. Zaier

The Journal of Engineering Research

A nonlinear friction is an unavoidable phenomenon frequently experienced in mechanical system between two contact surfaces. An adaptive compensator is designed to achieve tracking of a desired velocity trajectory in the presence of friction force described by a single state elastoplastic friction model. The adaptive compensator includes an adaptive observer and a computed force controller. The closed loop system is shown to be stable using Lyapunov second method. Simulation results show the effectiveness of the proposed compensator.

Go to article

Different Zoom Approaches For Improving Spectral Resolution With Applications In Radar Signal Processing, A. Hossen, U. Heute Apr 2025

Different Zoom Approaches For Improving Spectral Resolution With Applications In Radar Signal Processing, A. Hossen, U. Heute

The Journal of Engineering Research

Different approaches for a high-resolution analysis of narrow-band spectra are reviewed and compared. Partial-band algorithms are proved to be zoom-FFT's. In this contribution, three new modifications of the (Subband-FFT) SB-FFT are presented. In the first modification the chirp z-transform substitutes the small FFT which calculates the band of interest. In the second modification, the idea of zero-padding the input signal is applied to the SB-FFT with pruning at both input and output. Lastly zooming a small band of frequencies using a method of transforming by parts is applied for a narrow-band signal using the adaptive SB-FFT. A newly introduced version …

Go to article

Boron Steel: An Alternative For Costlier Nickel And Molybdenum Alloyed Steel For Transmission Gears, A. Verma, K. Gopinath, B. Sarkar Apr 2025

Boron Steel: An Alternative For Costlier Nickel And Molybdenum Alloyed Steel For Transmission Gears, A. Verma, K. Gopinath, B. Sarkar

The Journal of Engineering Research

Case Carburized (CC) low carbon steels containing Ni, Cr and Mo alloying elements are widely used for transmission gears in automobile, as it possesses desired mechanical properties. In order to cut cost and save scarce materials like Ni and Mo for strategic applications, steel alloyed with Boron has been developed, which gives properties comparable to Ni-Cr-Mo alloyed steel. In the process of steel development, care was taken to ensure precipitation of boron which results in precipitation hardening. The characterization of the developed boron steel had exhibited properties comparable to Ni-Cr-Mo alloyed steel and superior to conventional boron steel.

Go to article

Effective Flange Width For Composite Steel Beams, T. Salama, H.H. Nassif Apr 2025

Effective Flange Width For Composite Steel Beams, T. Salama, H.H. Nassif

The Journal of Engineering Research

The effective flange width is a concept proposed by various codes to simplify the computation of stress distribution across the width of composite beams. Questions have been raised as to the validity of the effective slab width provisions, since they have a direct effect on the computed ultimate moment as well as serviceability limit states such as deflection, fatigue, and overloading. The objective of this paper is to present results from an experimental and analytical investigation to determine the effective slab width in steel composite beams. The Finite Element Method (FEM) was employed for the analysis of composite steel-concrete beams …

Go to article

Exploring Possible Seasonal Trends In Mortality Rate In Relation To Age, Gender And Environmental Conditions In Kuwait: A Preliminary Analysis, N. Al-Rifaia, A. Elmi, A.R. Khan Apr 2025

Exploring Possible Seasonal Trends In Mortality Rate In Relation To Age, Gender And Environmental Conditions In Kuwait: A Preliminary Analysis, N. Al-Rifaia, A. Elmi, A.R. Khan

The Journal of Engineering Research

Inherently, Kuwait a high frequency of dusty events through out the year due to its arid climate. Particulate air pollution has been linked to increased mortality due to various illnesses. For the purpose of improving health services, it is important to develop/establish an empirical basis for the possible link between mortality and air quality. In this paper, we examined mortality rates in Kuwait in relation to age, sex and dust episodes during a five-year period. Each year was divided into four seasons to detect any potential episodes in the death rate for a particular season. The results showed that the …

Go to article

Influence Of Residual Stress On Fatigue Design Of Aisi 304 Stainless Steel, L. Singh, R.A. Khan, M.L. Aggarwal Apr 2025

Influence Of Residual Stress On Fatigue Design Of Aisi 304 Stainless Steel, L. Singh, R.A. Khan, M.L. Aggarwal

The Journal of Engineering Research

Austenitic stainless steel cannot be hardened by any form of heat treatment, in fact, quenching from 10000C merely softens them. They are usually cold worked to increase the hardness. Shot peening is a cold working process that changes micro-structure as well as residual stress in the surface layer. In the present work, the compressive residual stress and fatigue strength of AISI 304 austenitic stainless steel have been evaluated at various shot peening conditions. The improvement in various mechanical properties such as hardness, damping factors and fatigue strength was noticed. Compressive residual stress induced by shot peening varies with cyclic loading …

Go to article

Neuro-Fuzzy Sensor Fault Diagnosis Of An Induction Motor, M. L. Benloucif Apr 2025

Neuro-Fuzzy Sensor Fault Diagnosis Of An Induction Motor, M. L. Benloucif

The Journal of Engineering Research

In this paper, a neuro-fuzzy fault diagnosis scheme is presented and its ability to detect and isolate sensor faults in an induction motor is assessed. This fault detection and isolation (FDI) approach relies on a combination of neural modelling and fuzzy logic techniques which can deal effectively with nonlinear dynamics and uncertainties. It is based on a two step neural network procedure: a first neural network is used for residual generation and a second fuzzy neural network performs residual evaluation. Simulation results are given to demonstrate the efficiency of this FDI approach.

Go to article

Class-E Amplifier Design Improvements For Gsm Frequencies, Z. Nadir, F. Touati Apr 2025

Class-E Amplifier Design Improvements For Gsm Frequencies, Z. Nadir, F. Touati

The Journal of Engineering Research

Efficient power amplifiers are essential in portable battery-operated systems such as mobile phones. Also, the power amplifier (PA) is the most power-consuming building block in the transmitter of a portable system. This paper investigates how the efficiency of the power amplifier (which is beneficial for multiple applications in communcation sector) can be improved by increasing the efficiency of switching mode class E power amplifiers for frequencies of 900 MHz and 1800 MHz. The paper tackles modeling, design improvements and verification through simulation for higher efficiencies. This is the continuation of previous work by the authors. These nonlinear power amplifiers can …

Go to article

A Simplified Procedure For Reliability Estimation Of Underground Concrete Barriers Against Normal Missile Impact, N. A. Siddiqui Apr 2025

A Simplified Procedure For Reliability Estimation Of Underground Concrete Barriers Against Normal Missile Impact, N. A. Siddiqui

The Journal of Engineering Research

Underground concrete barriers are frequently used to protect strategic structures like Nuclear power plants (NPP), deep under the soil against any possible high velocity missile impact. For a given range and type of missile (or projectile) it is of paramount importance to examine the reliability of underground concrete barriers under expected uncertainties involved in the missile, concrete, and soil parameters. In this paper, a simple procedure for the reliability assessment of underground concrete barriers against normal missile impact has been presented using the First Order Reliability Method (FORM). The presented procedure is illustrated by applying it to a concrete barrier …

Go to article

A New Universal Second-Order Filter Using Configurable Analog Building Blocks (Cabs) For Filed-Programmable Analogue Arrays, M. T. Abuelma'atti, O. O. Fares Apr 2025

A New Universal Second-Order Filter Using Configurable Analog Building Blocks (Cabs) For Filed-Programmable Analogue Arrays, M. T. Abuelma'atti, O. O. Fares

The Journal of Engineering Research

In this paper, the design of a universal second-order filter using configurable analog blocks (CABs) for field programmable analog arrays is presented. The configurable blocks are capable of performing integration, differentiation, amplification, log, anti-log, add and negate functions. To maintain high frequency operation, the programmability and configurability of the blocks are achieved by digitally modifying the block's biasing conditions. Using at most four CABs, this article shows that it is possible to design a versatile second-order filter realizing all the standard five filter functions; lowpass, highpass, bandpass, notch and allpass. SPICE simulation results using practical bipolar junction transistor (BJT) parameters …

Go to article

A General Model For Describing The Performance Of Brushless Doubly-Fed Induction Machines, S. M. Allam, A. M. Azmy, M. A. El-Khazendar Apr 2025

A General Model For Describing The Performance Of Brushless Doubly-Fed Induction Machines, S. M. Allam, A. M. Azmy, M. A. El-Khazendar

The Journal of Engineering Research

This paper presents a generalized model, by which the dynamic and steady-state behaviour of the Brushless Doubly-Fed Induction Machine (BDFIM) can be precisely predicted. The investigated doubly-fed machine has two sets of three-phase stator windings with different pole numbers. The rotor is a squirrel-cage type with a simple modification in order to support the two air-gap rotating fields that are produced by the stator windings and have different pole numbers. The machine model is derived in the qdo-axis variables. The qdoaxes are attached to rotor and hence, it rotates at the rotor speed (

Go to article

Impacts Of Wind Power Variability On Generation Costs - An Overview, M. H. Albadi, E. F. El-Saadany Apr 2025

Impacts Of Wind Power Variability On Generation Costs - An Overview, M. H. Albadi, E. F. El-Saadany

The Journal of Engineering Research

Although wind power is sustainable, environmental friendly and relatively inexpensive source of electricity, the effects of its intermittent nature on power systems need to be carefully investigated. This paper presents an up-to-date overview of the impacts of wind power variability on overall generation cost. Recent case studies from different utilities around the globe demonstrated that wind integration costs are much lower than anticipated by earlier studies.

Go to article

Performance Comparison Of Adaptive Estimation Techniques For Power System Small-Signal Stability Assessment, E. A. Feilat Apr 2025

Performance Comparison Of Adaptive Estimation Techniques For Power System Small-Signal Stability Assessment, E. A. Feilat

The Journal of Engineering Research

No abstract provided.

Go to article

Mutual Coupling Reduction Between Axial-Mode Helical Antennas Using Single-Negative (Sng) Magnetic Metamaterials, M. M. Bait-Suwailam, O.M. Ramahi Apr 2025

Mutual Coupling Reduction Between Axial-Mode Helical Antennas Using Single-Negative (Sng) Magnetic Metamaterials, M. M. Bait-Suwailam, O.M. Ramahi

The Journal of Engineering Research

This paper investigates the mutual coupling effects between axial-mode helical antenna arrays. Single-negative (SNG) magnetic metamaterials are developed and used in this work in order to reduce mutual coupling between axial-mode helical antennas used in multiple-input multiple-output systems. The inclusions considered here are composed of broadside coupled split-ring resonators. The magnetic permeability of those SNG inclusions have complex effective magnetic permeability response over a frequency band with high negative real part above the resonance and positive real part below the resonance. The SNG resonators are inserted between closely-spaced axial-mode helical antenna elements. Effective responses of the constitutive parameters of the …

Go to article

Mimo Channel Gain Mechanisms Relative To Siso Channel, A. A. Abouda, N.G. Tarhuni Apr 2025

Mimo Channel Gain Mechanisms Relative To Siso Channel, A. A. Abouda, N.G. Tarhuni

The Journal of Engineering Research

In contrast to the rest of wireless communication technologies, multiple-input multiple-output (MIMO) technology enjoys different gain mechanisms that make it very attractive for reliable high data rate wireless communications. This paper presents a study on these gain mechanisms with particular emphasis on the case of high average received signal to noise ratio (SNR) where the MIMO system deployment is most promising. We write the MIMO channel capacity in terms of gains relative to a single- input single-output (SISO) wireless channel. Doing so, spatial multiplexing gain and power gain of MIMO wireless channels become more insightful. Based on this analysis a …

Go to article

Design Of A Realistic Test Simulator For A Built-In Self Test Environment, A. Ahmad, Muscat, Sultanate Of Oman, D. Al-Abri, Muscat, Sultanate Of Oman Apr 2025

Design Of A Realistic Test Simulator For A Built-In Self Test Environment, A. Ahmad, Muscat, Sultanate Of Oman, D. Al-Abri, Muscat, Sultanate Of Oman

The Journal of Engineering Research

This paper presents a realistic test approach suitable to Design For Testability (DFT) and Built- In Self Test (BIST) environments. The approach is culminated in the form of a test simulator which is capable of providing a required goal of test for the System Under Test (SUT). The simulator uses the approach of fault diagnostics with fault grading procedure to provide the tests. The tool is developed on a common PC platform and hence no special software is required. Thereby, it is a low cost tool and hence economical. The tool is very much suitable for determining realistic test sequences …

Go to article

A Multi-Resolution Texture Image Retrieval Using Fast Fourier Transform, A. Abdesselam Apr 2025

A Multi-Resolution Texture Image Retrieval Using Fast Fourier Transform, A. Abdesselam

The Journal of Engineering Research

Texture is an important visual property that characterizes a wide range of natural and artificial images which makes it a useful feature for retrieving images. Several approaches have been proposed to describe the texture contents of an image. In early research works, such as edge histograms-based techniques and co-occurrence-based approaches, texture descriptors were mainly extracted from the spatial domain. Later on, dual spaces (transform of spatial domain) such as frequency space or spaces resulting from Gabor or wavelet transforms were explored for texture characterization. Recent physiological studies showed that human visual system can be modeled as a set of independent …

Go to article

Analysis Of Buffer Arrangements In Low And High Dimensional Networks, N. Alzeidi Apr 2025

Analysis Of Buffer Arrangements In Low And High Dimensional Networks, N. Alzeidi

The Journal of Engineering Research

Virtual channels have been introduced to enhance the performance of wormhole-switched networks. They are formed by arranging the buffer space dedicated to a given physical channel into multiple parallel buffers that share the physical bandwidth on a demand driven time-multiplexed manner. The question to be answered is: given a fixed amount of finite buffer what is the optimal way to arrange it into virtual channels. There have been few studies attempting to address this issue, however, these studies have so far resorted to simulation experiments and focused on deterministic routing algorithms. In this paper we use analytical performance models to …

Go to article

Zigbee-Based Telemetry System, L. Khriji, F. Touati, N. Hamza Apr 2025

Zigbee-Based Telemetry System, L. Khriji, F. Touati, N. Hamza

The Journal of Engineering Research

Nowadays, there is a significant improvement in technology regarding healthcare. Real-time monitoring systems improve the quality of life of patients as well as the performance of hospitals and healthcare centers. In this paper, we present an implementation of a designed framework of a telemetry system using ZigBee technology for automatic and real-time monitoring of Biomedical signals. These signals are collected and processed using 2-tiered subsystems. The first subsystem is the mobile device which is carried on the body and runs a number of biosensors. The second subsystem performs further processing by a local base station using the raw data which …

Go to article

Estimating Optimum Compaction Level For Dense-Graded Hot-Mix Asphalt Mixtures, Khalid Al Shamsi, Louay N. Mohammad Apr 2025

Estimating Optimum Compaction Level For Dense-Graded Hot-Mix Asphalt Mixtures, Khalid Al Shamsi, Louay N. Mohammad

The Journal of Engineering Research

A critical step in the design of asphalt mixtures is laboratory compaction. Laboratory compaction should reflect field compaction and should produce mixtures that are economical and possess high structural stability. During the compaction process, asphalt mixtures are subjected to certain amount of compaction energy in order to achieve the required density. The Superpave volumetric mix design is based on compacting HMA mixtures to a specified compaction level described by the number of gyrations from the Superpave gyratory compactor (SGC). This level is termed Ndes and represents the required energy (based on the traffic level expected) to densify the mixture to …

Go to article

First Prev Next Last