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2003

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Full-Text Articles in Engineering

Влияние На Окружающую Среду Технологии Непрерывного Литья, Marian Mazur, Marek Bogacki, Robert Oleniacz, Agnieszka Łopata Dec 2003

Влияние На Окружающую Среду Технологии Непрерывного Литья, Marian Mazur, Marek Bogacki, Robert Oleniacz, Agnieszka Łopata

Robert Oleniacz

This article presents a complex analysis of the impact of the technology of continuous casting of steel (CCS) on the rate of the air pollutant emissions from one of the Polish steel and iron plants. The emission sources occurring in the production process have been identified and their rate has been determined. The implementation of CCS has brought about significant changes in the production cycle of the steel plant and it also has caused an increase of the production effectiveness of steel products. The calculated environment effects have shown a considerable emission decrease of all pollutants in the scale of ...


A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar Dec 2003

A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar

Dissertations

Existing adaptive traffic control strategies lack an effective evaluation procedure to check the performance of the control plan after implementation. In the absence of an effective evaluation procedure, errors introduced in the system such as inaccurate estimates of arrival flows, are carried forward in time and reduce the efficiency of the traffic flow algorithms as they assess prevalent traffic conditions. It is evident that the feed-forward nature of these systems cannot accurately update the estimated quantities, especially during oversaturated conditions.

This research is an attempt to develop a conceptual framework for the application of feedback control within the basic operation ...


A Micromachined Thermo-Optical Light Modulator Based On Semiconductor-To-Metal Phase Transition, Lijun Jiang Dec 2003

A Micromachined Thermo-Optical Light Modulator Based On Semiconductor-To-Metal Phase Transition, Lijun Jiang

Dissertations

In this research, a micromachined thermo-optical light modulator was realized based on the semiconductor-to-metal phase transition of vanadium dioxide (VO2) thin film. VO2 undergoes a reversible phase transition at approximately 68 0C, which is accompanied with drastic changes in its electrical and optical properties. The sharp electrical resistivity change can be as great as five orders. Optically, VO2 film will switch from a transparent semiconductor phase to a reflective metal phase upon the phase transition. The light modulator in this research exploits this phase transition related optical switching by using surface micromachined low-thermal-mass pixels to achieve good ...


Migration Of An Intruder Particle In A Boundary Driven Shear Flow, Jian Liu Dec 2003

Migration Of An Intruder Particle In A Boundary Driven Shear Flow, Jian Liu

Dissertations

This study reports on three-dimensional, discrete element simulations of a single large spherical intruder in a Couette shear flow composed of uniform sized particles. The simulation results are useful in providing a numerical reproduction of the experiments for size segregation and mixing. This in turn has a major importance in many industries which are concerned with handling of particles and powders, such as pharmaceutical manufacturing, agriculture, chemical and mineral processing.

Discrete element simulations are carried out using the "soft sphere" model of Walton, et. al., which provides a method for obtaining the information at a macroscopic level from multi-body collisions ...


The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu Dec 2003

The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu

Dissertations

CSO discharges have long been recognized as a significant source of water pollution. While many sources of water pollution have been controlled over the past 20 years, CSOs continue to be a main environmental concern in several areas, especially in old cities. In the past, most CSO research focused on the CSO control processes, including floatables and suspended solids removal. Few studies have been conducted in the area of the impacts of CSO discharge on the receiving water quality. To achieve this purpose, a powerful water-modeling tool, WASP 6.1, is utilized in this study. The Lower Hudson River is ...


Effect Of Fullerene Containing Lubricants On Wear Resistance Of Machine Components In Boundary Lubrication, Andriy Titov Dec 2003

Effect Of Fullerene Containing Lubricants On Wear Resistance Of Machine Components In Boundary Lubrication, Andriy Titov

Dissertations

Fullerenes, a new form of carbon nanomaterials, possess unique physical and mechanical properties that make their use as additives to liquid lubricants potentially beneficial. The goal of this study was to investigate the effect of fullerene containing lubricants on wear resistance of steel-bronze couples operating under boundary lubrication conditions. A mathematical model of deformed asperity contact was built to calculate real contact area and real contact pressure. Computer controlled wear friction testing methodology and equipment were designed, developed and implemented for obtaining reliable and objective experimental data. In addition, optical and scanning electron microscopy and standard surface texture analysis were ...


Studies On Improved Integrated Membrane-Based Chromatographic Process For Bioseparation, Yanke Xu Dec 2003

Studies On Improved Integrated Membrane-Based Chromatographic Process For Bioseparation, Yanke Xu

Dissertations

To improve protein separation and purification directly from a fermentation broth, a novel membrane filtration-cum-chromatography device configuration having a relatively impermeable coated zone near the hollow fiber module outlet has been developed. The integrated membrane filtration-cum-chromatography unit packed with chromatographic beads on the shell side of the hollow fiber unit enjoys the advantages of both membrane filtration and chromatography; it allows one to load the chromatographic media directly from the fermentation broth or lysate and separate the adsorbed proteins through the subsequent elution step in a cyclic process.

Interfacial polymerization was carried out to coat the bottom section of the ...


Ip-Based Virtual Private Networks And Proportional Quality Of Service Differentiation, Jingdi Zeng Dec 2003

Ip-Based Virtual Private Networks And Proportional Quality Of Service Differentiation, Jingdi Zeng

Dissertations

IP-based virtual private networks (VPNs) have the potential of delivering cost-effective, secure, and private network-like services. Having surveyed current enabling techniques, an overall picture of IP VPN implementations is presented.

In order to provision the equivalent quality of service (QoS) of legacy connection-oriented layer 2 VPNs (e.g., Frame Relay and ATM), IP VPNs have to overcome the intrinsically best effort characteristics of the Internet. Subsequently, a hierarchical QoS guarantee framework for IP VPNs is proposed, stitching together development progresses from recent research and engineering work.

To differentiate IP VPN QoS, the proportional QoS differentiation model, whose QoS specification granularity ...


Vibration-Induced Densification Of Granule Materials, Ninghua Zhang Dec 2003

Vibration-Induced Densification Of Granule Materials, Ninghua Zhang

Dissertations

Physical experiments as well as discrete element simulations of vibration are carried out. The use of different amplitudes and frequencies are applied in the experiments to facilitate the observation of densification trends with mono-disperse acrylic spheres and multi-disperse polyethylene pellets. For mono-disperse acrylic spheres, four densification trends are found at different vibration conditions, and attaining the "maximum density" is closely related to the combination of vibration frequency and amplitude, in agreement with experiments in the literature. For multi-disperse polyethylene pellets, there is a substantial increase in solids fraction due to the effects of particle shape and surface friction. Computer simulations ...


Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li Dec 2003

Intercity Travel Demand : A Utility-Consistent Simultaneous Trip Generation And Mode Choice Model, Guilin Li

Dissertations

An intercity travel decision includes a complex set of subdecisions, such as when to travel, where to travel, which mode to choose, and others. The main focus of this dissertation is to examine trip frequency and mode choice of intercity non-business travel.

The objective of this study is to understand intercity travel behavior using disaggregate models. The proposed conceptual framework for intercity travel behavior leads to a nested logit/continuous choice model that is rigorously linked to the utility maximization theory. Compared to a traditional intercity travel demand model, the proposed model is utility consistent in that trip generation and ...


Fabrication And Characterization Of Microcrystalline Silicon Solar Cells, Liwei Li Dec 2003

Fabrication And Characterization Of Microcrystalline Silicon Solar Cells, Liwei Li

Dissertations

In this study, single junction p-i-n μc-Si:H solar cells were prepared using plasma of silane diluted by hydrogen in a low-cost, single chamber, non-load-locked RF-PECVD system. Direct structural characterization of μc-Si:H solar cells, rather than stand-alone films, was conducted using Raman Spectroscopy, XRD, and AFM. Strong correlations among device deposition, i-layer structural properties, and device performance have been established. With such correlations, critical issues in fabricating low-cost, large-scale, high performance μc-Si:H solar cells were identified.

The critical importance of seeding processes in determining the microstructure of μc-Si:H i-layers and performance of μc-Si:H solar ...


Oblivious Data Hiding : A Practical Approach, Husrev T. Sencar Dec 2003

Oblivious Data Hiding : A Practical Approach, Husrev T. Sencar

Dissertations

This dissertation presents an in-depth study of oblivious data hiding with the emphasis on quantization based schemes. Three main issues are specifically addressed:

1. Theoretical and practical aspects of embedder-detector design.

2. Performance evaluation, and analysis of performance vs. complexity tradeoffs.

3. Some application specific implementations.

A communications framework based on channel adaptive encoding and channel independent decoding is proposed and interpreted in terms of oblivious data hiding problem. The duality between the suggested encoding-decoding scheme and practical embedding-detection schemes are examined. With this perspective, a formal treatment of the "processing" employed in quantization based hiding methods is presented. In ...


Reactive Modification Of Polyesters And Their Blends, Chen Wan Dec 2003

Reactive Modification Of Polyesters And Their Blends, Chen Wan

Dissertations

As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be ...


Transmission Of Light And Audible Sound In A Synthetic Fog Medium, Bhavin Babaria Dec 2003

Transmission Of Light And Audible Sound In A Synthetic Fog Medium, Bhavin Babaria

Theses

The primary goal of the thesis was to study the propagation of visible light and auditory sound through a synthetic fog medium compared to an ambient air environment. It is known that the fog substantially decreases the visibility however; this has not been studied quantitatively. Further information regarding other energies such as sound is also needed to understand how the energy reacts in the fog medium. The extent of visual and auditory degradation in humans needs to be investigated. Researchers have studied light transmitted through water, air; however, no one has studied how light or sound is transmitted through a ...


Pulsed Laser Ablation Deposition And Optical Characterization Of Hexagonal-Wurtzite Silicon, Berzelius Ybanez Cada Dec 2003

Pulsed Laser Ablation Deposition And Optical Characterization Of Hexagonal-Wurtzite Silicon, Berzelius Ybanez Cada

Theses

Hexagonal-wurtzite silicon phase silicon is an unusual polymorph of silicon with potentially useful electro-optical properties. Previous studies using a simple deposition system demonstrated that laser ablation of the standard cubic-diamond silicon produces droplets containing hexagonal-wurtzite crystallites. In order to study the process parameters and to deposit larger hexagonal crystals, a new pulsed laser ablation system with variable parameters was assembled and tested. Deposition expenments were performed in high vacuum with different laser pulse power. Raman spectroscopy showed that the new system successfully produces hexagonal-wurtzite silicon. The droplet size distributions, measured with an optical microscope, were found to depend on the ...


Characterization Of Aluminum Powder Ignition, Salil Mohan Dec 2003

Characterization Of Aluminum Powder Ignition, Salil Mohan

Theses

Heating rate effect and particle size effect on ignition temperature of Al powder were studied to collect data for development of a possible Al powder ignition model. Aluminum ignition is associated with a highly accelerated burn rate and high combustion enthalpy. A new ignition model, which can adequately interpret these conditions, is needed to develop better propulsion fuels, explosives and incendiaries that use Al as an additive. This experimental program was focused on preparing framework for characterization of ignition kinetics of Al powder by determining the ignition temperature for different, systematically varied, heating rates and particle size. The experimental setup ...


Modeling And Analysis Of Hospital Facility Layout Problem, Amol Shrikrishna Padgaonkar Dec 2003

Modeling And Analysis Of Hospital Facility Layout Problem, Amol Shrikrishna Padgaonkar

Theses

The optimal solution to any facility layout problem is an important aspect and a major concem as it involves significant material handling and transportation cost. The objective is to arrange the departments within the predefined facility boundaries in the way that the interaction between the functions is efficient and the overall movement cost is minimized. While facility layout problems have traditionally focused on manufacturing facilities, there has been little work on analyzing layouts for hospitals. The thesis focuses on hospital facility layout problems (HLP) to (i) minimize the movements of patients and (ii) minimize the movements of accompanying resources such ...


Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo Dec 2003

Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo

Theses

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user's joints for suppressing tremor.

This thesis is based on the concept of "smart structures" which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable ...


Configurable Computer Systems Can Support Dataflow Computing, Anish Arvind Sathe Dec 2003

Configurable Computer Systems Can Support Dataflow Computing, Anish Arvind Sathe

Theses

This work presents a practical implementation of a uni-processor system design. This design, named D2-CPU, satisfies the pure data-driven paradigm, which is a radical alternative to the conventional von Neumann paradigm and exploits the instruction-level parallelism to its full extent. The D2-CPU uses the natural flow of the program, dataflow, by minimizing redundant instructions like fetch, store, and write back. This leads to a design with the better performance, lower power consumption and efficient use of the on-chip resources. This extraordinary performance is the result of a simple, pipelined and superscalar architecture with a very wide ...


Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah Dec 2003

Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah

Theses

SECTION I: Kinetics of HO2 Abstraction of H Atoms From Hydrocarbons

Structures, internal rotational barriers and ideal gas thermochemical properties, ΔH°f98 for representative series of transition states for abstraction of H atoms from primary, secondary and tertiary hydrocarbons by the HO2 radical, TC-HOOH (1), TCC-HOOH (2), TC2C-HOOH (3), TC3C-HOOH (4), TC2CC-HOOH (5), TC2CC-HOOHC (6) and TC3CCC-HOOH (7) are analyzed in this study. Molecular structures and vibrational frequencies are determined at the B3LYP/6-3111G(d,p) density functional level. The S°298 and Cp(T) values (300 ...


Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar Dec 2003

Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar

Theses

Deadlock occurrence is a critical problem for any computer network. Various solutions have been proposed over last two decades to solve problem of deadlocks in networks using different routing schemes, like up/down routing algorithm used in Myrinet switches. However, most of existing approaches for deadlock-free routing either try to eliminate any possibility of deadlock occurrence, which can result in putting extra restrictions on the routing in the networks or put no restrictions on routing, which leads to other approach namely deadlock recovery. In this thesis emphasis is on developing hybrid approach for routing in wormhole networks, wherein some prohibition ...


Chemical Vapor Deposition Of Polymeric Films, Chi Yu Dec 2003

Chemical Vapor Deposition Of Polymeric Films, Chi Yu

Theses

Poly-peri-naphthalene (PPN) is a one-dimensional (1 -D) graphite polymer with unique planar ladder-like conjugated molecular structure. PPN was predicted to be a good intrinsic conductor and have high thermal stability and high environmental stability.

In this project, chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD) of carbon films with PPN structure using PTCDA as precursor were carried out under different conditions. There is only limited information in literature on the synthesis of PPN films by PECVD process, which may allow deposition at a higher rate with lower substrate temperature. In this work the influence of deposition parameters ...


Spatially Varying Threshold Models For The Automated Segmentation Of Radiodense Tissue In Digitized Mammograms, Richard Edson Eckert Iii Dec 2003

Spatially Varying Threshold Models For The Automated Segmentation Of Radiodense Tissue In Digitized Mammograms, Richard Edson Eckert Iii

Theses and Dissertations

The percentage of radiodense (bright) tissue in a mammogram has been correlated to an increased risk of breast cancer. This thesis presents an automated method to quantify the amount of radiodense tissue found in a digitized mammogram. The algorithm employs a radial basis function neural network in order to segment the breast tissue region from the remainder of the X-ray. A spatially varying Neyman-Pearson threshold is used to calculate the percentage of radiodense tissue and compensate for the effects of tissue compression that occurs during a mammography procedure. Results demonstrating the efficacy of the technique are demonstrated by exercising the ...


Evaluation Of The Flail Space Model Utilizing Event Data Recorder Technology, Douglas John Gabauer Dec 2003

Evaluation Of The Flail Space Model Utilizing Event Data Recorder Technology, Douglas John Gabauer

Theses and Dissertations

Developed in the early 1980's, the flail space model has become the standard method for estimating occupant risk in full-scale crash tests involving roadside safety features. The widespread availability of airbags and increased seat belt usage rates in today's vehicle fleet, however, raise serious questions regarding the validity of the model. Recent implementation of Event Data Recorder (EDR) technology in a number of late model vehicles presents a different perspective on the assessment of the validity of occupant risk based on the flail space model. EDRs are capable of electronically recording data such as vehicle speed, brake status ...


Multi-Sensor Data Fusion Using Geometric Transformations For The Nondestructive Evaluation Of Gas Transmission Pipelines, Philip James Kulick Dec 2003

Multi-Sensor Data Fusion Using Geometric Transformations For The Nondestructive Evaluation Of Gas Transmission Pipelines, Philip James Kulick

Theses and Dissertations

Nondestructive evaluation (NDE) plays a vital component in the operation and maintenance of large infrastructure such as gas transmission pipelines, nuclear power plants, aircraft, bridges and highways, etc. As this infrastructure continues to age it is essential that the inspection techniques reliably and accurately predict the integrity of these systems. No single NDE method is capable of inspecting all types of anomalies and extracting all required information – a combination of methods must be used and the resulting data fused. Moreover, newer systems that are developed are often made of composite materials that include metals and dielectrics. One interrogation modality cannot ...


Simultaneous Heat And Mass Transfer To A Liquid Through Two Separated Interfaces, Ku-Il Park Dec 2003

Simultaneous Heat And Mass Transfer To A Liquid Through Two Separated Interfaces, Ku-Il Park

Theses

The oxygenator is the main element of a heart-lung machine, which takes over the work of the lungs (adding oxygen to and removing carbon dioxide from the blood) during an operation. Oxygenators function by passing oxygen through a hollow fiber (straw-like fiber), where blood gases are exchanged via tiny pores in the fiber walls. In this study, a fiber-in-fiber technology was used to design a temperature controlled blood oxygenator membrane module. A Celgard® X-10 hollow fiber was put through the lumen of a polypropylene hollow fiber having a solid wall. Both fibers are made of polypropylene and are waterproof due ...


Combustion Of Aerosolized Spherical Aluminum Powders And Flakes In Air, Binu Zacharia Eapen Dec 2003

Combustion Of Aerosolized Spherical Aluminum Powders And Flakes In Air, Binu Zacharia Eapen

Theses

Combustion rates and completeness of aerosolized spherical aluminum powders and flakes are compared using constant volume explosion experiments. The comparison of particles and flake sizes was made based on their specific surface areas determined using the Brunauer-Emmett-Teller (BET) method and respective "BET diameters". It is observed that the rates of pressure rise and rates of flame propagation were higher for aluminum powders with BET diameters of about 2 to 5 μm compared to aluminum flakes for which the BET diameters were under 1 μm In agreement with the flame propagation rates, the overall completeness of combustion was also higher for ...


Development Of Fmri Compatible Lower Body Negative Pressure System, Pratap Singh Kunwar Dec 2003

Development Of Fmri Compatible Lower Body Negative Pressure System, Pratap Singh Kunwar

Theses

The lower body negative pressure (LBNP) system provides a controlled, measured orthostatic stress to the cardiovascular system, which can be used with a magnetic resonance imaging (MRI) machine to study cardiovascular and cerebrovascular responses to graded LBNP. In the past, even though functional MRI (fMRI) was considered as one of the best modalities with which to measure small metabolic changes in the brain, it has not been used with an LBNP system to measure cerebrovascular changes. This was due to the lack of an fMRI compatible LBNP system.

In this project, an tMRI compatible LBNP system was first constructed without ...


Hdl Implementation Of A Controller Area Network Node, Anthony Richard Marino Dec 2003

Hdl Implementation Of A Controller Area Network Node, Anthony Richard Marino

Theses and Dissertations

With increasing technology inside automobiles, especially law enforcement vehicles, there is a growing need for centralized wiring and device interconnection methods. Each new technology, such as GPS navigation units and in-vehicle video systems, includes a corresponding wiring harness that needs installation. The summation of all these hardwired technologies leads to large volumes of wire that negatively affect safety, power demands, and future design opportunities. A new trend among automotive manufacturers is to design and implement innovative networks that allow for shared communications between technologies.

This thesis presents the design, development, and implementation of an in-vehicle network that will centralize connections ...


A Labview Program To Obtain The Initiating Component Of A Vergence Eye Movement In An Open-Loop Experiment, Anuj P. Daftari Dec 2003

A Labview Program To Obtain The Initiating Component Of A Vergence Eye Movement In An Open-Loop Experiment, Anuj P. Daftari

Theses

The vergence oculomotor system is used in viewing objects moving in depth, such as when a baseball player tracks a ball moving towards him. It is composed of two components according to the Dual Mode Theory; a fast preprogrammed initiating component and a slow feedback-controlled sustaining component. The initiating component is described with open-loop control and the sustaining component is described as a closed-loop feedback control system. Previously, several languages have been utilized to develop programs to study and isolate the open-loop portion of vergence eye movements. Presenting a subject with a stimulus, which initiates an open-loop response has been ...