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Full-Text Articles in Engineering

Automated Distribution And Management Of Software And Hardware Configurations For Heterogeneous Wireless Devices, Grainne Foley Jan 2003

Automated Distribution And Management Of Software And Hardware Configurations For Heterogeneous Wireless Devices, Grainne Foley

Theses

The continuing evolution of wireless networks and services has increased the complexity and diversity of wireless networks and devices, placing significant emphasis on the need for flexible device configuration management. Widely varying wireless technologies currently operate independently worldwide, making global wireless network access for the mobile user confusing and unwieldy. New technologies, network access methodologies and improved services further obscure the evolving environment. The focus of effort for this thesis is the development of a system to automate the distribution and management of software and hardware configurations that enable different levels of wireless device reconfiguration. The scope of investigation will …


Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis Jan 2003

Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis

Theses

Photovoltaics are devices that convert sunlight directly to electricity. It is well established that the conversion efficiency of mono and poly-crystalline silicon-based photovoltaic modules is inversely related to their temperature. Substantial improvements in operational performance can thus be achieved if the thermal energy accumulating in the material can be effectively dissipated.

Accurate modelling of modules would allow possible methods of thermal dissipation to be evaluated, and as a crucial component of the model, the thermal properties of the constituent materials of PV modules needed to be known. Special consideration needed to be given to the interfaces between dissimilar materials and …


Experiments With A Galton Board, Christopher Oshman May 2002

Experiments With A Galton Board, Christopher Oshman

Theses

Galton boards have been used for over a half-century as a tool to illustrate the formation of Gaussian shaped distributions as well as the Central Limit Theorem. Here, the Galton board was used to study the spontaneous percolation of a particle through an ordered array of rigid scatterers. The apparatus that was designed and fabricated provided a means to release 1/8" diameter spheres one at a time in a controlled and precise manner at any location on the board. The three experimental variables used in these experiments were the particle material, the release height, and the board tilt. angle. The …


Assessment Of The Recycled Concrete Aggregates Structural Suitability For Road Construction, Abdulla Yousef Ali Al-Ali Jun 2001

Assessment Of The Recycled Concrete Aggregates Structural Suitability For Road Construction, Abdulla Yousef Ali Al-Ali

Theses

In most aspects of modem life, there is a consensus among practitioners and decision makers of the importance of preserving the environment, and to find alternatives to the scarce natural materials. This can be accomplished by better utilization of the natural materials and/or recycling or reclaiming their waste, specially, if they are of finite resources. The recycled material could be an attractive alternative (both environmentally and economically) if its characteristics are proven to be close to those of the natural material.

Utilizing recycled mineral aggregates in the construction field in general and in highway pavement in specific is somehow governed …


Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu Jan 2001

Development And Application Of A Computer Simulation Tool For Ecological Risk Assessments, Haiyi Lu

Theses

In an effort to improve tools in ecological risk assessment (ERA), an ERA software tool was developed and applied. Based on a preliminary evaluation of existing ecorisk models, the relative deficiencies were identified and included the need for a user-friendly interface, an interactive database management system (DBMS), and a comprehensive evaluation of exposure pathways. In this research, Visual Basic (VB) 6.0 and Microsoft SQL server were selected for developing the Windows-based interface and local DBMS, respectively. For the exposure estimate, Yuma and Aberdeen Proving Grounds were identified as baseline ecosystems. Terrestrial and aquatic plant and animal receptor selection was based …


Nanofiltration-Based Diafiltration Process For Solvent Exchange In Pharmaceutical Manufacturing, Jignesh P. Sheth Aug 2000

Nanofiltration-Based Diafiltration Process For Solvent Exchange In Pharmaceutical Manufacturing, Jignesh P. Sheth

Theses

Commercially available solvent stable polymeric nanofiltration membranes were used to study the nanofiltration and diafiltration operations in the context of the pharmaceutical industry. Experimental results are presented for a two-step operation involving the preconcentration of a feed solution via nanofiltration followed by the replacement of the first stage solvent with a second solvent via diafiltration in two stages. Membranes MPF-50 and MPF-60, having molecular weight cut-offs of 700 and 400 respectively, were used in the present study. A solution of erythromycin (MW 734) in ethyl acetate was preconcentrated via nanofiltration followed by replacement of ethyl acetate with methanol via batch …


Investigation Of The Relevance Of Heart Rate Variability Changes After Heart Transplantation, Sheeba Arnold Jan 2000

Investigation Of The Relevance Of Heart Rate Variability Changes After Heart Transplantation, Sheeba Arnold

Theses

Heart transplantation has become an established treatment for end-stage heart disease. However, the shortage of donor organs is a major problem and long-term results are limited by allograft rejection. Heart rate variability (HRV) has emerged as a popular noninvasive research tool in cardiology. Analysis of HRV is regarded as a valid technique to assess the sympathovagal balance of the heart. The primary goal of this study was to investigate the relevance of heart rate variability changes after heart transplantation. It was found that spectral analysis of HRV is useful in detecting rejection episodes. Heart transplantation leaves the donor heart denervated. …


The Relationship Between Thermoregulatory And Haemodynamic Responses Of The Skin To Relaxation And Stress, Paul O. Nketia May 1997

The Relationship Between Thermoregulatory And Haemodynamic Responses Of The Skin To Relaxation And Stress, Paul O. Nketia

Theses

The present study investigated the effects of stress and relaxation on (1) EEG coherence and (2) peripheral blood flow.

EEG coherence of two meditators in two different but adjacent rooms was measured during eyes opened, eyes closed, single meditation and group meditation. The skin temperatures of the subjects together with their room temperatures were also recorded. EEG coherence plots (Cospar) showed a spread out of the alpha band to the beta, theta and occasionally to the delta wave bands during group meditation. The area above the 0.98 coherence threshold in the alpha band was greater during group meditation than during …


Modeling Arsenic Transformation In Clay Soils, Chao-Yi Chung Jan 1994

Modeling Arsenic Transformation In Clay Soils, Chao-Yi Chung

Theses

This project is designed to estimate the possible transformation forms of arsenic in clay soil. A computer model was established to simulate arsenic transformations. The amount of arsenic species adsorbed, dissolved, and the predominant soluble species are calculated by the model, which is mainly based on the Freundlich adsorption isotherm, solubility data collected by Keaton and Kardos, and pH-Eh diagram established by Ferguson and Garvis. The computer language used is Turbo PASCAL version 5.5.

The clay soil environment is considered to be in standard state: 25°C 1 atm. Environmental factors of the soil system which are accounted for by the …


Polarimetric Fiber Optic Weigh-In-Motion Sensor, Jieping Wang Jan 1994

Polarimetric Fiber Optic Weigh-In-Motion Sensor, Jieping Wang

Theses

During the past decade, the demand for new methods of measuring the weight of moving vehicles has grown substantially. In the 1980's, several techniques for weighing vehicles in motion were developed. However, they often suffer from high installation and maintenance costs as well as low accuracy. This thesis describes a new technique based on polarization preserving optical fibers. A fibercore HB600 Bow-Tie fiber with an initial beat length of 1.16 mm was employed in the present study. Sensor response is discussed in terms of the effects of force amplitudes and velocities on the calibration parameter Tf. Tf …


Coordinate Measuring Machines : A Modern Inspection Tool In Manufacturing, Matthias Richard Mantel May 1993

Coordinate Measuring Machines : A Modern Inspection Tool In Manufacturing, Matthias Richard Mantel

Theses

Coordinate Measuring Machines (CMM) are flexible and universal dimensional measuring devices with the capability for full integration into a CIM information network. Developed as highly precise measuring machines for specially designed measuring rooms, today's CMMs are more and more used in shop floor applications which is a hostile environment for a precise measuring tool. CMMs are offered in a variety of configurations and levels of automation. For the CMM buyer it is therefore essential to have an overview of the different types of CMMs and their subsystems before making a purchasing decision.

To obtain reliable measuring results that are used …


Management Of Construction Jobsite Productivity : A Self Assessment Approach, Nicos Poliviou Nicolaou May 1989

Management Of Construction Jobsite Productivity : A Self Assessment Approach, Nicos Poliviou Nicolaou

Theses

A critical component of construction project management is the improvement of jobsite productivity. This paper proposes a procedure for use by project managers to assess jobsite productivity performance. The methodology provides a framework which when applied will identify specific aspects of the jobsite where potential productivity improvement is possible. A major feature is its systematic approach which will direct the project manager to the specific resources which when better managed will lead to lower construction costs.


Scanning Electron Microscopy And X-Ray Energy Dispersive Spectroscopic Analysis Of Selected Sorbent Materials, Elhamy Amin Sedhom May 1989

Scanning Electron Microscopy And X-Ray Energy Dispersive Spectroscopic Analysis Of Selected Sorbent Materials, Elhamy Amin Sedhom

Theses

A previous study(1) showed that a combination of acidic and basic sorbents in a layered system is required to reduce to safe levels the contaminants present in the leachates emanating from industrial landfills. The sorbents used were fly ash, vermiculite, kaolinite, illite, zeolite, apautagite, bentonite, activated carbon and bauxite.

The purpose of this investigation is to study the physical properties, elemental composition and the distribution of the aforementioned solid sorbents. Properties of interest are particle size, shape and distribution and also the chemical composition and the distribution of the elements within the sample particles.

Scanning Electron Microscopy (SEM) and …


Variations Of Alkalinity, Ph, Oxidation Reduction Potential, And Conductivity In Single And Multi-Stage Sludge Digestion Systems, Nasser M. Kamazani May 1989

Variations Of Alkalinity, Ph, Oxidation Reduction Potential, And Conductivity In Single And Multi-Stage Sludge Digestion Systems, Nasser M. Kamazani

Theses

Anaerobic digestion is used at many municipal and industrial wastewater treatment plants. Recent increase in the cost of energy and search for an alternative source of energy for the future have prompted renewed interest in anaerobic digestion for energy recovery by production of methane from waste materials, including wastewater sludges and agricultural and municipal solid wastes. Accordingly, a large literature exist on the subject, most of it dealing with more physical aspects of different process design. Little or not enough attention has been paid to its highly complex biochemical characteristics.

The purpose of this study is a preliminary investigation regarding …


C/Ku Band Satellite Television Reception System, Costas A. Economides May 1988

C/Ku Band Satellite Television Reception System, Costas A. Economides

Theses

The purpose of this thesis is to examine and investigate the design of a satellite reception system able to receive most C and Ku band North American geostationary satellites' TV transmissions. The performance criterion used for the system design is based on a required demodulated video signal-to-noise ratio maintained for a specified percentage of time in conjunction with overall cost considerations.

Furthermore, a computer program written in FORTRAN 77 is developed, which among other functions lists the notified, operational, geostationary satellites in sight with their corresponding look angles, from any given location on the earth.


Graphical Interpretation Of U.S. Tidal Data, Vaheh Shahbazian May 1987

Graphical Interpretation Of U.S. Tidal Data, Vaheh Shahbazian

Theses

Numerous Shore line operations relating to industry and conservation would benefit from convenient access to continuous tidal predictions. Easy Graphical access to continuous long term predictions of tidal heights at a location of interest will simplify operations that are sensetive to tidal predictions. A specific example, is the implementation of a protective measurements against flooding and destruction of shoreline facilities particularly at times of high tides.

This thesis consists of three things. First, rendering NOAA's data in a form accessable to a PC user. Second, it provides a Basic program for prediction of tides. Third , PC user programming Resourses …


Technology Transfer Between Developed And Developing Countries, Tenny Oghogho Ogbomo May 1986

Technology Transfer Between Developed And Developing Countries, Tenny Oghogho Ogbomo

Theses

The problems arising from technology transfer, in general, are not new. The problems of the East-West technology transfer, for example, are based on the risk that such transfers will enhance the military capability, or at least the military potential, of the trading partner. In the case of United States trade with the Soviet Union, it can be said that any accretion in the Soviet military capacity weighs against the United States in an overall world-wide balance of power. The restrictions and/or prohibition of such transfer of technology are problems themselves.

The North-South technology transfer, in other words, the technology transfer …


The Effects Of Heavy Metals On The Chick Embryo Development, Yasmin Alibhai May 1984

The Effects Of Heavy Metals On The Chick Embryo Development, Yasmin Alibhai

Theses

The following is a research report on the effects of heavy metals on the avian embryo. A total of eight metals were used in the study. The metalE included were : cobalt, copper, indium, iron, manganese, molybdenum, arsenic and cadmium. A total of 800 eggs were used for the study. Salts of each of the metal were dissolved in physiological saline and injected into the air sacs of white Leghorn chick eggs. Dose levels varied with the metal to be tested. Control eggs were injected with an equivalent volume of saline (0.1 ml per egg). The eggs were injected on …


Separation Of Glucose - Fructose - Water Systems Via Thermal Parametric Pumping, Zikri Mostafa Ahmed May 1973

Separation Of Glucose - Fructose - Water Systems Via Thermal Parametric Pumping, Zikri Mostafa Ahmed

Theses

Series of experiments were carried out to determine the effect of different factors on adsorption from aqueous solutions of sugar using fuller's earth ( LW 16-30 Mesh ) as an adsorbent. The equilibrium data were fitted to the Langmuir's equation., and an explanation for the deviation of some of these data has been given.

Systems of glucose-fructose and water mixtures were subjected to semi-continuous and continuous parametric pumping operations using activated carbon (400 Filterasorb) as an adsorbent. The results obtained confirm the equilibrium theory of the parametric pump and essentially fulfill the requirements established by Chen and Hill (6) to …


Reliability Considerations For Communication Satellites, Frank Polizzi May 1968

Reliability Considerations For Communication Satellites, Frank Polizzi

Theses

A detailed program covering all phases of reliability for a communication satellite was presented. In long mission programs such as this one, reliability is the prime consideration in assuring a successful accomplishment of the stringent goals set forth. Reliability principles and methods were incorporated in delineating each major task in the program. These principles and methods not only aided the reliability personnel in performing their duties better, but also assisted the design group, manufacturing personnel, and the testing and evaluation group in performing their jobs efficiently by being aware and knowledgeable of reliability engineering.

Various reliability disciplines were imposed, as …