Digital Commons Network^™

Trajectory Analysis For An Industrial Robotic System., Kamel Soliman

Mansoura Engineering Journal

The present paper introduces a general scope about the growing role of industrial robot system in modern industries. A dynamic model for a two links robot is introduced mechanics. The dynamic behavior of such robotics system is oscilacting on the system. A computer program based on Runge-Kutta-R-K) fourth order method with variable step, is designed to study the dynamic behavior of such robotic system. A suggested technique for choosing the most suitable control input (controlling torque) for such nonlinear system is introduced. The steps of the suggested technigue are classified as follows:- For each link different stable trajectory are assumed …

Mathematical Modelling Of Transient Processes In The Capacitive Take-Off Power Network., Ibrahim Mansy, A. Aly, Saad Eskander

Mansoura Engineering Journal

This paper presents a mathematical modelling of the transient processes in a capacitive take-off power network. This model is based on the calculation of magnetic flux of a single-phase, two-winding transformer. This model is represented by non-linear equations. The short circuit occurs along the steel core, and the leakage flux coupling the separated coils closes out the side of core. The mathematical model is developed to investigate the conditions of transient process analysis in a capacitive take-off power network. The reduction of overvoltage during short circuit period is also studied in this paper. Also, this paper suggests the solution manner …

Investigation Of Heat Transfer And Fluidization Dynamics Around Horizontal Bundle Tube In Fluidized Bed., Mohamed Sheta

Mansoura Engineering Journal

Experiments were performed on a fluidized bed model with a cross section of 80*85mm and a height of 1.2m. Sand particles were used as a bed material. Measurements of specific air consumption, pressure drop, mean wall temperature, bed temperature distributions and particle sizes have been carried out. Some primary experiments were carried out at ambient temperature to study fluidization characteristics of sand particles. The measurements were taken at near room temperature and ambient pressure using three sand particle sizes dp < /sub> = 2.32, 1.60 1.10mm). Experimental results for heat transfer coefficient and aerodynamic characteristics between immersed bundles of horizontal smooth tubes …

Adaptive Enhacement Of Ambulatory Electrocardiograms., Fatma El-Zahraa Abou-Chadi

Mansoura Engineering Journal

Quality improvement of ambulatory electrocardiographic (ECG) signals is an important subject and crucial in computer aided diagnosis and monitoring. However, the poor quality of the signals necessitates signal enhancements. Hence, in this paper, three adaptive filter structures are presented to eliminate the diverse forms of noise. The performance of each technique 18 thoroughly investigated by simulated signals as well as signals obtained from human subjects. A two stage filter consisting of an adaptive noise cancellar and adaptive recurrent filter has been found to reduce efficiently the various types of noise while the characteristics of the relevant ECG signal is little …

Optimum Shunt Capacitor For Power Factor Compensation In The Presence Of Harmonics., Mohamed El-Saied, Gabr Abd El-Sallam, Abd El-Rahman Amin

Mansoura Engineering Journal

Power consumers require both reliable service and a acceptable voltage profile. The presence of nonlinear loads in power system generate harmonics which affect, in particular, the shape and magnitude of the supplied voltage, Classical design of capacitors for power factor compensation has been based on the undamental frequency analysis. However, the presence of harmonics and distortion, the compensated power factor is the short circuit generally worse. Additionally, according to capacity at the load bus, the calculated capacitor value could result in harmonic resonant conditions. A direct search technique known as Fibonacci Method (II) has been employed to determine the optimum …

The Behaviour Of Geotextiles Under Arid Weather Conditions Kuwait As A Case Of Study., Mohamed Ali, H. El-Mudhaf

Mansoura Engineering Journal

This paper investigates the behaviour of geotextiles at exposure, storage and burial in soil in a hot dry climate. Kuwait was chosen as it experiences a wide range of annual temperature throughout the year, with air temperature rising to 55°C in summer and dropping to 0°C in winter. It also has an extremely high UV radiation level with long hours of uninterrupted sunshine on most of the days of the years. Two geotextiles presently used for separation and reinforcement applications, were fully exposed, stored out of sunlight and buried in soil at the depth of 0.5 m and 1.5 m. …

Machinability Parameters In Finish Face Milling Of Low Alloy Cr-Ni Steel With Thr K30 Carbide Tool Part Ii: Surface Finish, Machined Surface. Texture, Minor Cutting Edge And Nature Of Chips., Fayez Abo-Gharbia

Mansoura Engineering Journal

The second contribution presents the results of finish face milling in which the performance of THR K30 reported in terms of surface roughness and machined surface alterations when a low alloy steel in its hardened conditions was milled. The assessment of surface finish and the mechanisms involved in particular front and back cutting were defined. Details are given corresponding to the geometry of tool, elastic deformation and feed marks transferred to surface during front curling. Also, in back cutting, the surface refining by burnishing process on the trailing end culling edge was comprehensively explained. The effect of minor flank wear …

An Investigation For Improving The Quality Of Thermo-Plastic Extrusion Products By Using New Statistical Method., Farouk Rashed

Mansoura Engineering Journal

The traditional quality control procedures are adopted to reduce the variation in the process during the manufacturing stage. Modern quality control techniques are utilized as quality engineering in the design stage. In this paper a statistical quality control technique based on Taguchi method has been developed. The objective is to determine the optimum combination of the process characteristics that reduce performance variation while keeping the process average close to its target value. As well, various aspects of off line quality control procedures are discussed in this paper. Off-line quality control refers to quality and cost control activities at the product …

A Contribution To The Study Of Flow Field And Heat Transfer On A Rearward - Facing Step., Awad El-Hadik

Mansoura Engineering Journal

The flow and convective heat transfer characteristics over a backward-facing step were investigated numerically and experimentally. Two different step-heights were studied for different Reynolds numbers. The point of reattachment of the flow behind the step proved to be the point of maximum heat transfer coefficient. The size of the separated region as well as the Nus sell number depended greatly on the Reynolds number. Downstream of reattachment, the heat transfer coefficient declined rapidly and followed gradually the contour of the turbulent hound ary layer. The results of the investigation were compared to others from the literature with sat-isfaction.

Morphology Of Discontinuous Precipitates In Nitrogenized 316 L Steel., Fawzy El-Sabbahy

Mansoura Engineering Journal

316 L steel specimens, wt %, (18 Cr - 8 Ni - 2 Mo) containing nitrogen in the range of 0.02 - 0.6 wt% in powder form, were solution treated at 1100°C for 30 min. followed by water quenching. Solution treated materials were subjected to aging at temperatures of 700 and 800°C for several intervals of time. X-ray diffraction and Scanning electron microscopy were used to study the morphology of the precipitates at different aging conditions. The hardness of these materials was determined. The morphology and size of the precipitates produced during aging were observed to depend on the aging …

High Frequency Transformer Modeling Based On Time Domain Solution., Youssef Abed, Fathi Youssef, Brahim Metwally, Ahmed Saber

Mansoura Engineering Journal

A new model for the high frequency transformer simulation is presented in this paper. The power transformer, is vital and expensive pieces of the power system, should be studied and investigated for all possible operational stresses. To this extend, a wide range of frequency covering all possible transient conditions is to be investigated. In this work a new model, which enables the calculation of transformer transient voltage response is presented. The model is based on measurements in high frequency domain using low voltage high frequency generator. The introduced new model is simple to be programmed using available programs like, “MATLAB …

Stability Of Frequency Control Of Power Generating Systems Based On The Sliding Mode Technique., F. Areed, Mohamed Salem

Mansoura Engineering Journal

In the present paper, a new algorithm for solving the control problem in electrical power systems, is introduced. This new algorithm is based on the sliding mode property existing in variable structure system (VSS). The resulting control law is discontinuous by its nature. However, it does not require accurate informations about the system parameters or its manner of variation. The only requirements are the maximum and minimum limits of variation for each parameter, An adaptive controller is designed for an electrical power system, on the basis of that new algorithm The main function of the controller is the frequency control …

A New Technology To Combat Oil Spills On Water Surface Using A Ribbed-Grooved Disc Skimmer., Nabil El-Minshawy

Mansoura Engineering Journal

In offshore oil spills a thin oil layer has to be skimmed off from the sea surface. A mechanism for cleanup of oil spill from water surface was developed using a ribbed grooved rotating disc. The effect of various compound surface configurations of the two opposite walls of the considered ribbed-grooved disc on the oil recovery performance was investigated for various disc rotational speed. Tests have been carried out for recovering fresh oil spill as well as weathered oil spill. Generally this clean up operation has to be carried out in sea water with different conditions, so the oil recovery …

Effect Of Operating Conditions On The Mixed Convection In A Channel With Discrete Heat Sources And Partially Filled With Porous Media., M. El-Kady

Mansoura Engineering Journal

An experimental study of laminar mixed convection in a partially filled porous channel with two discrete heat sources on the bottom wall was performed The main object is to show the effect of Reynolds number, the heat flux, and Grashof number on the heat transfer characteristics. A channel of 120x120mm cross section and length of 200mm is fitted in a low turbulence wind channel. The passages above the heat sources are filled with patous layers and the channel is non-porous the heat sources are elsewhere. The air flow velocity was varied up to 3 m/s which gives a variation of …

Critical Heat Flux In Convective Boiling In Nuclear Reactors., Mohamed Mahgoub

Mansoura Engineering Journal

To asses the safety margin of a light water reactor during the postulated loss of coolant accident (LOCA) it is important to predict the peak clad temperature. To perform such a task thermohydraulic codes to have been developed. Among the inputs to the computer codes, heat transfer equations which are used to determine the heat transfer coefficient in various heat transfer modes, Prediction of the critical heat flux (CHF) - as a limiting condition-is therefore of vital importance. The purpose of this paper is to recommend -based on the current state of knowledge - a set of correlationswhich are used …

Optimum Radius Of Cylinderical Envelope Of Solar Energy Receiver., Mahmoud Awad

Mansoura Engineering Journal

This paper presents an analytical procedure for estimation of the optimum radius of the cylindrical envelope of solar energy receiver. The cylindrical solar absorber and the envelope of the solar receiver are located horizontally and their axes are coincided. The study is based on the fact of the variation of the convective heat loss from the solar receiver to the surrounding air by varying the envelope radius for a given absorber radius and given boundary conditions. For the case of an unevacuated air layer in the cylindrical space in between the solar absorber and the envelope it is found that …

The Influence Of Interspersed A Six-Phase Stator Winding On The Mmf Harmonic Analysis., Abd El-Rahman Amin

Mansoura Engineering Journal

The influence of interspersed a six-phase winding by one slot on the space MMF harmonic analysis has been investigated , by means of Goerg's vector diagram. Two types of six-phase windings with ẟ either equal to 30or 60 electrical degrees are considered. These two tupes of windings are likely to be existed in practice. The scope of investigation covers the double-layer winding, two-pole, q=3 slots, either for interspersed arrangement or conventional arrangement. The principles of interspersed the six-phase windings are described and compared with the conventional arrangement in terms of harmonic analysis. From which, it is shown that, controlling the …

Data Processors For Power System Control., Mofreh Mohamed, Faiez Areed, Kamel Soliman

Mansoura Engineering Journal

In modern control centers, Data Processor (DP) has been installed to process the unreliable and erroneous telemetered data. The main focus of the present paper is concerned with developing more efficient algorithm of Parallel Data Processing (PDP), to generate satisfactory results with minimum amount of computation expense and implementation costs Both algorithms of the conventional Central Data Processor (CDP) and the proposed POP are programed. The effectiveness of PDP is verified by number of tests on different models of power systems under extreme conditions. A set of results for PDP and for CDP are obtained The results show that more …

Tapered Contact Flocculation; Process And Application., Ahmed Ashry

Mansoura Engineering Journal

Tapered Contact Focculation (TCF) is a modification of fixed bed contact flocculation. The process employs a bed of graded spherical plastic media to obtain a tapered velocity gradient. A general equation for calculating the velocity gradient in any fixed bed medium with spherical grains was developed using the Ergun equation for determining the head Joss across the medium. In the TCF process, theoretically, increasing the flocculation rate and temperature increase the G-value, while increasing the media diameter and porosity reduce the G-value. TCF can be applied to different water treatment plant systems which use flocculation. TCF media can be manufactured …

Predicting The Transient Stability Of Ceps Using Aes Method., Ibrahim Mansy

Mansoura Engineering Journal

Analysis of the stability of power systems following a transient disturbance involves the study of a large set of nonlinear differential equations. A new approach to the quantitative study of the transient stability of complex electric power systems (CEPS) is presented, using approximate evaluation of stability method (AES). The analytical steps for this method are detailed in this study. Also a constraint, which depends on the relative speed of angle variations, in applying this method for predicting the stability of CEPS is explained. The present work aimed to study the effect of many factors on the transient stability of a …

Study Of Heat Pipe Performance With Water/ Water-Based Nanofluid., Mohamed Saafan, Elsayed Elshafei, Osama Ali Ebraheem

Mansoura Engineering Journal

Thermal performance of a flat heat pipe cooling system is experimentally investigated. Pure water and Al2O3-water based nanofluids are used as working fluids. An experimental setup is designed and constructed to study its performance under different operating conditions. The effect of working fluid, filling ratio, volume fraction of nano-particle in the base fluid, and heat input rate on the average heat transfer coefficient and in turn the average Nusselt number are investigated. Total thermal resistance of the heat pipe for pure water and Al2O3-water based nanofluid are also predicted. Correlation is obtained to predict the influence of Prandtl number, filling …

Augmentation Of Solar Still Performance Using Flash Evaporation., A. El-Zahaby, A. Kabeel, A. Bakry, S. El-Agouz, O. Hawam

Mansoura Engineering Journal

A new design of a stepped solar desalination system with flashing chamber is experimentally investigated. The main objective of the investigation was to study the performance of step—wise water basin coupled with a spray water system by augmenting desalination productivity through using two air heaters. The effect of using the spray system for seawater is investigated experimentally at different velocities of the water sprays holder and Flow rates on the performance of the solar still in a previous article by the authors [ll. in the present article the effect of the inlet raw water temperature (at motor speed of 250 …

Investigating Acculturation, Health-Promoting Lifestyle, And Health Status Among Nigerian Immigrants In The United States, Frank Uche Akpati

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States has a significant number of immigrants from Africa. More come from Nigeria than other African countries. Even though acculturation influences health behavior in other cultures, this relationship is understudied in the Nigerian immigrant community in the United States which can influence their health care. This study examined the relationship between acculturation, health-promoting lifestyle, and health status of Nigerian immigrants. Key constructs from Berry’s acculturation model guided the study. Acculturation was conceptualized as occurring through varying levels of ethnic society immersion (ESI) and dominant society immersion (DSI). The study also examined the influence of education on acculturation using …

Numerical Studies Of Regularized Navier-Stokes Equations And An Application Of A Run-To-Run Control Model For Membrane Filtration At A Large Urban Water Treatment Facility, Jeffrey Belding

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation consists of two parts. The first part consists of research on accurate and efficient turbulent fluid flow modeling via a family of regularizations of the Navier-Stokes equation which are known as Time Relaxation models. In the second part, we look into the modeling application for the filtration/backwash process at the River Mountains Water Treatment Facility in Henderson, NV.

In the first two chapters, we introduce the Time Relaxation models and their associated differential filter equations. In addition, we develop the regularization method which employs the Nth van Cittert deconvolution operator, which gives rise to the family of models. …

Racial/Ethnic Disparities In Mental Health Diagnosis Of Maltreated Youth, Shadie Burke

UNLV Theses, Dissertations, Professional Papers, and Capstones

Racial/ethnic marginalized youth are more likely to receive a misdiagnosis of a mental health disorder than their White peers. Misdiagnosis contributes to existing disparities for racial/ethnic marginalized groups by leading to longer durations of untreated and worsening mental health symptoms. For maltreated youth, receiving a misdiagnosis can lead to a failure to connect with appropriate mental health services, medication regimens, therapeutic foster homes, and academic and developmental resources. To date, very few empirical studies have identified disparities in mental health diagnosis among racial/ethnic marginalized maltreated youth. The present study examined two key research questions: (1) what racial/ethnic disparities in diagnoses …

From Language Comprehension Towards General Ai, Binay Dahal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Language comprehension or more formally, natural language understanding is one of the major undertakings in Artificial Intelligence. In this work, we explore a few of the problems in language understanding using fixed deep learning models. Specifically, first, we look into question generation. Asking questions relates to the cognitive ability of language comprehension and context understanding. For that reason, making progress in question generation is significant. We introduce a novel task called “question generation with masked target answer” and propose various models and present the baseline result for the task. Next, we extend on the question generation task and develop a …

Factors Associated With Medication Decision Making In African American Families Of Children With Adhd: A Mixed Methods Study, Amy Glasofer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral pediatric disorder in the United States. Pharmacotherapy is a recommended component of treatment for ADHD. While medication treatment of ADHD is not optimized overall, minority groups experience medication treatment disparities. The persistently lower rates of medication treatment in minority groups may have culturally specific origins which cannot be generalized across minorities. The purpose of this dissertation was to assess and extend knowledge regarding medication decision making (MDM) in African American caregivers of children with ADHD. To assess the state of the science on ADHD disparities, a review of 41 descriptive studies exploring …

Determination Of The Presence Of Sars-Cov-2 In Environmental Surface And Air Samples From Public Areas In Las Vegas, Kristina Mihajlovski

UNLV Theses, Dissertations, Professional Papers, and Capstones

Contaminated surfaces and airborne spread are found to be among the main ways of coronavirus disease 2019 (COVID-19) transmission. Studies conducted in the hospital setting have shown that SARS-CoV-2 is found on frequently touched surfaces, personal protective equipment, and in air samples of patient isolation rooms. However, few environmental sampling studies have been done in public areas. Taking in consideration that COVID-19 cases may be symptomatic, presymptomatic, and asymptomatic, environmental monitoring may be essential for prompt detection of the virus. The objective of this study was to determine whether SARS-CoV-2 can be detected on environmental surfaces and from air samples …

Computational Sodium Heat Pipe Simulation In Three Dimensions For Transient Nuclear Reactor Analysis With Variable Surface Heat Flux, Valerie Jean Lawdensky

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heat pipes are used to transfer heat through phase change in a liquid/vapor contained in a metal tube. They are passive devices that require no pumps to circulate the fluid and can transfer heat far more efficiently than a solid copper rod of the same diameter. They are commonly used in laptop computers where copper heat pipes filled with water take heat away from the CPU and transfer the heat to air through a heat exchanger. Heat pipes were also used in the Kilopower nuclear reactor where higher temperatures required sodium as the working fluid with stainless steel tubes. Computer …

Exploring Treatment Targets To Mitigate Fear Of Falling Activity Avoidance Behavior In Parkinson's Disease And Older Adults, John Vincent Rider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fear of falling (FOF) is a significant concern among individuals with Parkinson’s disease (PD) and older adults in general. This FOF can lead to avoidance behavior resulting in activity restriction. Some level of fear of falling avoidance behavior (FFAB) may be protective (adaptive) and decrease the likelihood of falls, especially among individuals with physical limitations and high fall risk. However, excessive (maladaptive) avoidance behavior may lead to downstream consequences such as further physical and psychological decline and an increased likelihood of falls, especially when there is a disparity between the FFAB and physiological fall risk. While poor physical functioning, disease …