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Articles 1351 - 1380 of 3470
Full-Text Articles in Engineering
Signal Processing Topics In Multicarrier Modulation : Frequency Offset Correction For Ofdm And Multiuser Interference Cancellation For Mc-Cdma, Pingping Zong
Theses
Orthogonal frequency division multiplexing (OFDM) is discussed as a special form of multi-carrier modulation (MCM). One major problem of the OFDM system is the sensitivity to an unknown frequency offset at the receiver. To improve the performance of the OFDM system, correction of the frequency offset is required before decision making. An adaptive method of frequency offset correction is presented. The adaptation algorithm used here is based on the LMS and the estimation is proven unbiased. A multiuser communications system having similar signal structure to the OFDM system, termed as multi-carrier code division multiple access (MC-CDMA), is discussed. The MC-CDMA …
Recovery Of Intracellular Materials By Electroporation, Wendy Elaine Reid
Recovery Of Intracellular Materials By Electroporation, Wendy Elaine Reid
Theses
Electroporation is commonly used to transfer genetic materials such as DNA into the cell by exposing the cell to a high electric field that momentarily permeabilizes the cell membrane. This premise was utilized to use electroporation as a means of releasing intracellular proteins. A procedure has been developed for the release of intracellular proteins through the use of electroporation. This procedure is a breakthrough. In general, industrial scale techniques to recover proteins from microorganisms are inefficient (Clarkson, 1993). A benefit of this electroporation-based mechanism would be the reduction of steps in the downstream processing required to purify the desired product. …
A Decision Support System For The Equipment Selection Of Robotic Manufacturing Cells, Lars Johan Resare
A Decision Support System For The Equipment Selection Of Robotic Manufacturing Cells, Lars Johan Resare
Theses
Considering the principles of concurrent engineering, a Decision Support System (DSS) is developed to aid in the equipment selection of robotic manufacturing cells. The objective is to synchronously and simultaneously select proper equipment for the cell to provide efficient performance, subject to operational and budgetary constraints.
The DSS consists of several modules, including a data base that houses the specifications of equipment available in the market place, a first cut selection module, and an optimization engine. In its development, the optimization scheme utilizes analytical models and algorithms that capture different sources of variability in production, such as tolerances, clearances and …
Microstrip Zero-Sum Antenna; Cad And Experimental Study, Tuan H. Lam
Microstrip Zero-Sum Antenna; Cad And Experimental Study, Tuan H. Lam
Theses
A microstrip antenna array consisting of two elements combined with a stripline hybrid (rat-race) ring coupler is used to implement a zero-sum antenna. Numerical optimization of individual antenna elements in terms of feed location and patch size was achieved using IE3D (Zeland Software Inc., Fremont, CA), a fullwave 3-D planar electromagnetic simulation software. Further, design of a hybrid (rat-race) ring coupler in a stripline environment was carried out, yielding the sum and difference functions as 0.5 dB and 40 dB, respectively. A combination of a two-element antenna array and a hybrid (rat-race) ring coupler as a zero sum antenna has …
Mixed Metal Removal And Recovery By Hollow Fiber Membrane-Based Extractive Adsorber, Ramprakash Chilukuri
Mixed Metal Removal And Recovery By Hollow Fiber Membrane-Based Extractive Adsorber, Ramprakash Chilukuri
Theses
The feasibility and efficiency of simultaneous removal of multiple cations as well as anionic heavy metals from wastewater into a mixed extractant kept stagnant on the shell side of a 2-fiber-set hollow fiber membrane extractor operated as a fixed bed adsorber was explored. The novel extracting solvent was a mixture of an acidic or chelating extracting agent for one or more cations and a basic extracting agent, e.g., trioctylamine (TOA) for extracting anions; both were dissolved in the same diluent kerosene for simultaneous and synergistic extraction of cations and anions. In the stripping part of the fixed bed operation, alkaline …
Electrophysiologic Studies Of Hypothalamic Adenosine-5'-Triphosphate-Sensitive Potassium Channels, Dinora Hernandez
Electrophysiologic Studies Of Hypothalamic Adenosine-5'-Triphosphate-Sensitive Potassium Channels, Dinora Hernandez
Theses
Of particular interest in this study were the electrical phenomena involving currents from the ATP sensitive K channel in isolated hypothalamic ventromedial nucleus (VMN) neurons. These neurons may play an important role in the glucose-sensing system of the body. Rat VMN neurons were isolated. For neuronal isolation, the proteolytic enzyme pronase was used. However, pronase was too harsh. The use of papain, another proteolytic enzyme, led to better neuronal morphology. The perforated patch clamp technique was used to gain access to the cell's interior. For membrane pore formation, nystatin was used; but seal formation was difficult. Amphotericin was used instead, …
Characteristics Of Recycled Plastics And Applications For Highway Appurtenances, Keith Macbain
Characteristics Of Recycled Plastics And Applications For Highway Appurtenances, Keith Macbain
Theses
Recycling is gaining widespread support in many communities as an environmentally acceptable solution to the management of solid waste. The success of these recycling programs depends largely on the development of high-value end use for the recycled products. This research involves an experimental and analytical study on the development of high-value, high-volume end uses for recycled plastic shapes. The experimental part includes material tests to determine mechanical properties of various recycled plastics. A constitutive model is proposed and verified that can be used in characterization of recycled plastics. Bending tests of recycled plastic beams were performed to assess strength, stiffness …
Mechanical Design Of An Experimental Parallel Robot, Philip Song
Mechanical Design Of An Experimental Parallel Robot, Philip Song
Theses
OSCAR, or Operational Space Controlled Adjustable Robot, is a parallel-actuated manipulator, also known as Stewart Platform or platform manipulator. The apparatus consists of two platforms (base and top) and six prismatic actuators in between. The main advantage of a platform manipulator is the fact that it can out-perform serial manipulators in both load capacity and precision. However, there are disadvantages and weaknesses such as limited mobility. A platform manipulator has reduced workspace compared to serial manipulators. The problem of limited workspace is solved by enabling OSCAR to change its prismatic leg positioning about the base platform.
During the course of …
Determination Of Effects Of Stress On Polymeric Ankle-Foot Due To Weight Change: Experimental Stress Analysis, Lin Yu Wang
Determination Of Effects Of Stress On Polymeric Ankle-Foot Due To Weight Change: Experimental Stress Analysis, Lin Yu Wang
Theses
Ankle-Foot Orthoses (AFOs) are devices that assist patients who sustained an abnormal motion at the ankle joint of the foot due to traumatic injury and stroke, etc. The objective of this project is to determine the stress patterns in AFOs under different loading conditions such as weights and genders. Thus, the location of failure can be predicted, and a redesign process can be developed. Furthermore, those experimental results will be used to verify the results obtained from the previous Finite Element Analysis (FEA) [11,10]. Results from the experiment showed a significant stress change due to load change. This stress …
Pervaporation-Assisted Esterification Of Salicylic Acid, Chaiya Chandavasu
Pervaporation-Assisted Esterification Of Salicylic Acid, Chaiya Chandavasu
Theses
The coupling of a pervaporation membrane unit with a reactor has been investigated as a means of improving the overall process efficiency. As model system, the esterification of salicylic acid with methanol in the presence of a homogeneous catalyst was studied in a unit consisting of a batch reactor externally coupled with a pervaporation module containing a composite poly(vinyl alcohol) membrane. The reaction was carried out at temperatures between 336 and 345 K. The catalyst was sulfuric acid at concentrations varying from 0.5 to 2.0 molar. Various initial molar ratios (ΘB) of methanol and salicylic acid, ranging from …
Development Of Aqueous Scrubber To Oxidize And Absorb Nitric Oxide, Wanna Lolertpiphop
Development Of Aqueous Scrubber To Oxidize And Absorb Nitric Oxide, Wanna Lolertpiphop
Theses
The use of sodium chlorite (NaClO2) and alkaline aqueous cumene hydroperoxide (CHP) as oxidizing agents to promote the absorption of nitric oxide from flue gases was investigated in a semicontinuous bubbling scrubber. The efficiency of the scrubbing solutions to remove nitric oxide was evaluated as a function of operating conditions such as pH, concentration of the oxidants, residence time, temperature, flue gas compositions.
Under acid conditions, sodium chlorite can stoichiometrically react and absorb 99.5% NO and 80% SO2 in the same scrubber with 0,672 M NaClO2 in buffered solution at pH 6, and 0.3 M NaOH. …
Computational Determination Of Laminar Flow Loss Coefficients In 90° Channel Bend, Leonard Paul Parkin
Computational Determination Of Laminar Flow Loss Coefficients In 90° Channel Bend, Leonard Paul Parkin
Theses
Loss coefficients for laminar two dimensional incompressible channel (or duct) flow in a 90° bend are investigated using FEM software, FIDAP. This problem consists of a two dimensional duct with a 90° bend of constant radius flowing with water, at 70°F and atmositeno conditions. The bend radius to duct width ratios examined were 1.5 and 1.0. Both bend radius to duct width ratios were analyzed for Reynolds Number ranging from 50 to 1800. The pressure and velocity distributions were found and used to determine the pressure due to the bend. The results show the pressure loss effect due to the …
Biodegradation Of Naphthalene Using Pseudomonas Putida (Atcc 17484) In Batch And Chemostat Reactors, Jay Boyd Best
Biodegradation Of Naphthalene Using Pseudomonas Putida (Atcc 17484) In Batch And Chemostat Reactors, Jay Boyd Best
Theses
Kinetic experiments were conducted using Pseudomonas putida (ATCC 17484) to determine the rate of growth when naphthalene was provided as a sole carbon source in suspended biomass systems. Batch and chemostat reactors were used under three sets of conditions: non-aerated, aerated at 29.5° C, and aerated at 25.5° C. A number of concentrations were tested under each set of conditions. Data regression was used to determine parameters for Monod (non-inhibitory), Andrews (inhibitory), and zero-order kinetics. Although the Andrews fit of the data provided a slightly lower sum-of-squares error (SSE), the amount of data scatter and the weak inhibition made the …
Modeling Of Deformed Swept Volumes With Sde And Its Applications To Nc Simulation And Verification, Feng Lu
Modeling Of Deformed Swept Volumes With Sde And Its Applications To Nc Simulation And Verification, Feng Lu
Theses
Representation of swept volumes has important applications in NC simulation and verification as well as robot-motion planning. Most research on .the representation of swept volumes has been limited to rigid objects. In this study, a sweep deferential equation (SDE) approach is presented for the representation of deformed swept volumes generated by flexible objects.
The deformed swept volume analysis is integrated with machining physics to account for tool deformation/deflection for the NC simulation. End milling is modeled and analyzed and the tool deformations are calculated and integrated with the SDE program. A program is developed in C++ for the generation of …
Multi-Lifecycle Assessment Of Cathode Ray Tubes, Devendra Jayant Badwe
Multi-Lifecycle Assessment Of Cathode Ray Tubes, Devendra Jayant Badwe
Theses
Over the past few years environmental issues and concerns have become more and more important, as they become a common part of most people's personal experience. In these regards, the electronics industry is facing substantial problems in terms of end-of-life management of its products, televisions and monitors in particular. The building blocks of this industry are usually viewed as relatively "clean". However, manufacturing by-products of the electronics industry and the disposition of electronics are becoming increasingly important technical, financial, and environmental issues.
Within the context of the above issues, environmentally responsible disposal of Cathode Ray Tubes (CRT's), which is still …
Soot Capture In An Electrocatalytic Reactor, Thana Slanvetpan
Soot Capture In An Electrocatalytic Reactor, Thana Slanvetpan
Theses
A major problem with many soot emission control devices is the fact that they quickly become loaded with soot which must be removed by a regeneration process. A soot capture reactor using a large flow channel was studied in order to eliminate channel plugging and avoid regeneration. Electrostatic precipitation was used in order to enhance particle diffusion to the catalyst wall of the reactor tube. The system effectiveness for soot capture was measured with filter paper sampling of the incoming versus the outgoing flow through the reactor. Soot filter loadings were analyzed by laser optical transmission. From the soot filter …
Synthesis And Characterization Of Phosphosilicate Glass Films By Lpcvd For Sensor Application, Hui Wu
Synthesis And Characterization Of Phosphosilicate Glass Films By Lpcvd For Sensor Application, Hui Wu
Theses
This study was dedicated to the synthesis of the thin film materials required to fabricate the waveguide and the reference arm barrier for integrated optical sensor. Phosphosilicate glass (PSG) thin films were synthesized on silicon and quartz wafers by LPCVD using Ditertiarybutylsilane(DTBS), Trimethylphosphite(TMP) and oxygen as precursors. The films were processed at different temperatures between 600°C and 700°C at a constant pressure, and at different flow rate of TMP.
The effect of TMP flow rate and deposition temperature on deposition parameters and the properties of PSG films were investigated. The films deposited were uniform, amorphous, low stress and the composition …
Using Heart Variability To Measure The Effects Of Manual Medicine On Autonomic Activity, Michael Zullow
Using Heart Variability To Measure The Effects Of Manual Medicine On Autonomic Activity, Michael Zullow
Theses
A pilot study was performed to test the theory that manual medicine techniques known as the CV4 (compression of fourth cerebral ventricle) maneuver and a sacral hold/iliac bridge hold combination increase parasympathetic activity. Manual medicine techniques are widely practiced by Doctors of Osteopathy and Chiropractors to treat physical and mental health problems. Those who have received manual therapy have reported to experience less pain, better mobility, and a greater feeling of relaxation. To help us learn about the effects of manual therapy, autonomic activity was measured scientifically rather than subjectively in this study by monitoring respiration rate and heart rate, …
Analysis And Modeling Of Ultrasound Enhanced Soil Washing Process, Kamalavathany Rajaratnam
Analysis And Modeling Of Ultrasound Enhanced Soil Washing Process, Kamalavathany Rajaratnam
Theses
In this research, statistical analysis of data from ultrasound enhanced soil washing process was performed. The process was optimized using a statistical model. The model had four factors namely power, solvent:soil, surfactant, and dwell time as process variables. The percentage of removal efficiency was considered as the dependent variable. The results from two full and one partial factorial designs were analysed. Interactions up to third order were considered in the analysis, but the results from full factorial design showed that those of order higher than second had insignificant contributions to the removal of contaminants. Since the higher order interactions of …
Analysis And Comparison Of Resistive, Ferroelectric And Pyroelectric Uncooled Bolometers For Electronic Imaging Systems, Mo-Huang Li
Theses
The performance parameters (responsivity (Rv). detectivity (D*), total noise and response time) of resistive, pyroelectric and ferroelectric bolometer detectors are dependent on a large number of key variables including chopping frequercy, the input impedance and voltage noise of the readout circuitry, the structure dependent parameters (particularly thermal conductance and thermal capacitance), and material properties such as dielectric constant, pyroelectric coefficient, loss tangent and thin film thickness. The interrelationship between the key variables and their influence on performance is often complex and not easily discerned for the three major types of thermal detectors: resistive, pyroelectric and ferroelectric bolometers.
In …
Analysis Of 320x240 Uncooled Microbolometer Focal Plane Array And Design Of Thermoelectric Cooler Controller, Takayoshi Fukaya
Analysis Of 320x240 Uncooled Microbolometer Focal Plane Array And Design Of Thermoelectric Cooler Controller, Takayoshi Fukaya
Theses
Uncooled microbolometer focal plane array is one of the promising method used in uncooled infrared imaging projects. The array's advantages over the conventional cooled imagers are its ability to operate without cryogenic cooler or dewar and its low cost. For the past several years, the ULTRA (Uncooled, Low cost, Technology Reinvestment Alliance) Consortium has been developing uncooled microbolometer imaging system.
This thesis investigates the technology behind the ULTRA camera system. The theoretical as well as the operation of the uncooled microbolometer focal plane array and the processing hardware and software is analyzed and explained.
Thermoelectric cooler controller for the microbolometer …
Growth Of Grass Shrimp, Palaemonetes Pugio, In A Contaminated And An Uncontaminated Site, Suruchi Bhan
Growth Of Grass Shrimp, Palaemonetes Pugio, In A Contaminated And An Uncontaminated Site, Suruchi Bhan
Theses
Previous experiments have found that grass shrimp, Palaemonetes pugio, from a contaminated site, Piles Creek (PC). in Linden. New Jersey, are larger than those from a relatively pristine reference site, Sheepshead Creek, located in Tuckerton (T), New Jersey.
This study investigated the possibility that PC conditions provide more food for the shrimp, possibly by being a eutrophic environment. thus allowing for greater growth. or that salinity, toxicants, or other factors at. PC stimulate growth. The current experiment indicated that PC conditions do not foster greater growth for the shrimp than T conditions and that PC shrimp are not inherently …
Equivalent Circuit Analysis Of A Seventh Order Bandpass Loudspeaker System, Michael Gunnar Johnson
Equivalent Circuit Analysis Of A Seventh Order Bandpass Loudspeaker System, Michael Gunnar Johnson
Theses
A seventh order bandpass loudspeaker system was designed using an equivalent circuit analysis. The electrical, mechanical and acoustic systems were each modeled as separate subcircuits derived by using a Voltage-Force-Pressure or impedance analogy; the interactions between the subcircuits were modeled using coupled controlled-sources. The equivalent circuit was analyzed using SPICE (Simulation Program with Integrated Circuit Emphasis). A technique for modeling port and cavity resonances inside the enclosure using distributed element approximations for the resonant components was developed and verified by measurement.
A complete microcomputer based experimental loudspeaker testing system was designed incorporating a sweep frequency oscillator, a gain-controlled audio power …
Heat Transfer Enhancement From A Heat Pipe Immersed Horizontally In Water, Under Natural Convection Conditions, With The Aid Of Gas Injection, Evangelos J. Minakas
Heat Transfer Enhancement From A Heat Pipe Immersed Horizontally In Water, Under Natural Convection Conditions, With The Aid Of Gas Injection, Evangelos J. Minakas
Theses
An experimental study has been performed to estimate the degree of heat transfer enhancement from a horizontal heat pipe, immersed in water with the aid of air injection. This thesis investigates the effects of different shroud shapes, shroud distances from the heat pipe, air injection rates, air injection configurations and air injection distances on the augmentation of heat transfer. Water was the experimental fluid and its temperature ranged from 17-60 °C, the surface temperature of the heat pipes varied from 18-75 °C.
It was discovered that the shape of the shrouds is a contributing factor on the heat transfer enhancement. …
Analysis Of Surface Texture Parameters And Cutting Forces In Milling Operations, Preetesh U. Munshi
Analysis Of Surface Texture Parameters And Cutting Forces In Milling Operations, Preetesh U. Munshi
Theses
It has been known and understood that milling is quite a complicated process being a multi-point cutting tool operation. Each Surface texture is complex and requires different functions of forces to get the optimized Surface Texture. The challenge faced here is to devise any form of relation between the Surface Texture and the Milling Operating parameters (Spindle Speed, Feed rate, Depth of Cut), Cutting forces and the Milling Operating parameters and also between the Surface Texture and the Cutting Forces.
This Research study was conducted to determine the effect of the Operating Parameters on Surface Texture and Cutting forces and …
The Relationship Between Thermoregulatory And Haemodynamic Responses Of The Skin To Relaxation And Stress, Paul O. Nketia
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 …
Renin-Angiotensin System And Its Relationship To Arterial Pressure Regulation, Sami D. Saume
Renin-Angiotensin System And Its Relationship To Arterial Pressure Regulation, Sami D. Saume
Theses
The renal system is known to participate in the natural regulation of blood pressure. A renal system model that simulates interaction responses of renal output to arterial blood pressure was developed. The major components of this model are glomerular filtration rate, tubular sodium reabsorption, the renin-angiotensin system, Aldosterone secretion, and antidiuretic hormone secretion. The model's differential equations were coded using Vissim 1.2 student version. It was found that, the renal output increased as glomerular filtration rate, Aldosterone concentration, and blood pressure increased. Conversely, increasing antidiuretic hormone concentration lead to decreased renal output.
Additionally, Angiotensin II and Aldosterone concentrations increased as …
Parameters' Analysis Of 3d Random Stacking Palletization, Najeeb Syed
Parameters' Analysis Of 3d Random Stacking Palletization, Najeeb Syed
Theses
Palletization is a very important element of production, distribution and warehousing activities. The 3D random stacking palletization method is based on volume utilization instead of surface area optimization. Random stacking provides interlocking among the boxes and hence it improves the stability of the pallet load. Volumetric Pallet Utilization is normally the prime concern of any palletization process, with Work in Process and Palletization time being also important. This research uses data generated from a previous heuristic to establish mathematical relationships between the three mentioned performance indices and also three additional indirect variables, namely: Total Number of Sub Volumes, Partitioned Remaining …
Computer Simulation Of Cerebrovascular Circulation : Assessment Of Intracranial Hemodynamics During Induction Of Anesthesia, Steven D. Wolk
Computer Simulation Of Cerebrovascular Circulation : Assessment Of Intracranial Hemodynamics During Induction Of Anesthesia, Steven D. Wolk
Theses
The purpose of this project was to develop a computer model of cerebrovascular hemodynamics interacting with a pharmacokinetic drug model to examine the effects of various stimuli during anesthesia on cerebral blood flow and intracranial pressure.
The mathematical model of intracranial hemodynamics is a seven compartment constant volume system. A series of resistances relate blood and cerebrospinal fluid fluxes to pressure gradients between compartments. Arterial, venous, and tissue compliance are also included. Autoregulation is modeled by transmural pressure dependent arterial-arteriolar resistance. The effect of a drug (thiopental) on cerebrovascular circulation was simulated by a variable arteriolar-capillary resistance. Thiopental concentration, in …
The Study Of Permeability In Concrete, Jie Yuan
The Study Of Permeability In Concrete, Jie Yuan
Theses
In this study, samples of regular, high performance, expansive and the polymer concrete and mortar were prepared for test of permeability and mechanical property. In the permeability measurement, water and an aqueous chemical solution were employed as the permeant.
The test results of the samples, ranging from 5.7 x 10-9 cm/sec to 1.0 x cm/sec for the permeability and 3800 psi to 10600 psi for compression strength, indicated that the polymer coated concrete has the lowest permeability among the concretes and high performance concrete has the highest compression strength . The finding leads to the possibility that a high strength …