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Articles 1 - 30 of 146
Full-Text Articles in Engineering
Microfluidics Fabrication And Testing For A Novel Biomems Cell Counting Device, Marly N. Dows
Microfluidics Fabrication And Testing For A Novel Biomems Cell Counting Device, Marly N. Dows
Honors Theses
No abstract provided.
Techniques For Low Power Analog, Digital And Mixed Signal Cmos Integrated Circuit Design, Chuang Zhang
Techniques For Low Power Analog, Digital And Mixed Signal Cmos Integrated Circuit Design, Chuang Zhang
LSU Doctoral Dissertations
With the continuously expanding of market for portable devices such as wireless communication devices, portable computers, consumer electronics and implantable medical devices, low power is becoming increasingly important in integrated circuits. The low power design can increase operation time and/or utilize a smaller size and lighter-weight battery. In this dissertation, several low power complementary metal-oxide-semiconductor (CMOS) integrated circuit design techniques are investigated. A metal-oxide-semiconductor field effect transistor (MOSFET) can be operated at a lower voltage by forward-biasing the source-substrate junction. This approach has been investigated in detail and used to designing an ultra-low power CMOS operational amplifier for operation at …
Interference Suppression And Parameter Estimation In Wireless Communication Systems Over Time-Varing Multipath Fading Channels, Jianqiang He
Interference Suppression And Parameter Estimation In Wireless Communication Systems Over Time-Varing Multipath Fading Channels, Jianqiang He
LSU Doctoral Dissertations
This dissertation focuses on providing solutions to two of the most important problems in wireless communication systems design, namely, 1) the interference suppression, and 2) the channel parameter estimation in wireless communication systems over time-varying multipath fading channels. We first study the interference suppression problem in various communication systems under a unified multirate transmultiplexer model. A state-space approach that achieves the optimal realizable equalization (suppression of inter-symbol interference) is proposed, where the Kalman filter is applied to obtain the minimum mean squared error estimate of the transmitted symbols. The properties of the optimal realizable equalizer are analyzed. Its relations with …
On The Stability Of Rotor Bearing Systems Based On Hopf Bifurcation Theory, Jianke Wang
On The Stability Of Rotor Bearing Systems Based On Hopf Bifurcation Theory, Jianke Wang
LSU Doctoral Dissertations
This research is aimed to establish instability criteria for a rotor-bearing system which consists of a rotor supported by two fluid-film journal bearings. The static and dynamic characteristics of rotor-bearing systems with consideration of turbulent effects are evaluated by applying the Hopf bifurcation theory (HBT) to the equations of motion. A method is developed for predicting the stability envelope of rotor-bearing systems using HBT. Results are compared with published literature obtained using a trial-and-error method. A method based on HBT is presented for predicting the occurrence of a hysteresis phenomenon, which is observed in experimental results dealing with the instability …
Laterally Movable Gate Field Effect Transistor (Lmgfet) For Microsensor And Microactuator Applications, In-Hyouk Song
Laterally Movable Gate Field Effect Transistor (Lmgfet) For Microsensor And Microactuator Applications, In-Hyouk Song
LSU Doctoral Dissertations
Laterally Movable Gate Field Effect Transistor (LMGFET) invented at LSU as a microactuator is the subject of study in this research. The gate moving in lateral direction in a LMGFET changes channel width but keeps the channel length and the gap between the metal gate and the gate oxide constant. LMGFET offers linear change in drain current with gate motion and a large displacement range. This research is the first demonstration of LMGFET. In this dissertation, a post-IC LIGA-like process for LMGFET microstructure fabrication has been developed that is compatible with monolithic integration with CMOS circuitry. A two-mask post-IC process …
Electrodeposition Of Auco Alloys And Multilayers, Maoshi Guan
Electrodeposition Of Auco Alloys And Multilayers, Maoshi Guan
LSU Master's Theses
Electrodeposited AuCo and Au/Co multilayers are of interest as potential materials for MEMS components. AuCo alloys have been fabricated by the electrodeposition technique, but from cyanide-containing electrolyte. In this study, we explored the electrodeposition of AuCo and Au/Co multilayer thin films, and nanowires, from a non-cyanide electrolyte. Two variables were considered: the concentration of citric acid and pH. The changes in composition were described by the differences in the partial current densities. The effect of pH and citric acid concentration on the deposit composition and current efficiency was investigated. Results showed that a lower citric acid concentration was favored for …
Flame Synthesis Of Carbon-Nanostructures, Saritha Perla
Flame Synthesis Of Carbon-Nanostructures, Saritha Perla
LSU Master's Theses
Ever since their discovery carbon nanostructures (nanotubes and nanofibers) have attracted a lot of interest, due to their striking physical, chemical, mechanical and electrical properties, and paves the path to a wide range of applications. Large quantities of these structures are necessary to make their applications viable. The challenge is to produce them in bulk and in an economical way. Current methods like Arc discharge have the disadvantages of short tube lengths, CVD generated nanomaterials are often riddled with defects and although laser ablation method produces pure and high yield of nanotubes, is a costly technique with expensive lasers and …
Simulations And Experimental Analysis Of High-Aspect-Ratio Diffusive Micro-Mixers, Amit Maha
Simulations And Experimental Analysis Of High-Aspect-Ratio Diffusive Micro-Mixers, Amit Maha
LSU Master's Theses
Passive (diffusional) mixing has been used in designing high-aspect-ratio micro-mixers for the purpose of performing the Liagase Detection Reaction (LDR). A simple model was used to design such mixers optimized for pressure drop or time required to deliver a prescribed volume of mixture. The types of mixers considered are simple, cheap, and durable and can perform over a broad range of volumetric flow rates at reasonably modest pressure drops. The fluids typically have a very low diffusion coefficient of=1.2x10^10m^2/s, and thus diffusional mixing can only be effective in high-aspect-ratio micro-channels. A realizable aspect ratio of 6 has been considered initially …
Electrodeposition Of Magnetic Nanowires And Nanotubes, Despina Mehedintu Davis
Electrodeposition Of Magnetic Nanowires And Nanotubes, Despina Mehedintu Davis
LSU Master's Theses
The current perpendicular to the plane giant magneto-resistance (CPP)-(GMR) effect makes multilayered nanowires of huge interest as magnetic sensor materials. GMR showing multilayer nanostructures are composed of alternating ferromagnetic and nonmagnetic nanometric layers. The giant magnetoresistance (GMR) property is described as a change in electrical resistance when an external magnetic field is introduced. Electrodeposition is the most efficient method for fabricating magnetic nanowires. In addition to the cost-effectiveness, electrodeposition is one of the few methods that can overcome the geometrical restrictions of inserting metals into very deep nanometric recesses, making it the favored method for nanowire and nanotube fabrication. In …
Traffic Engineering And Path Protection In Mpls Virtual Private Networks, Pooja S. Aniker
Traffic Engineering And Path Protection In Mpls Virtual Private Networks, Pooja S. Aniker
LSU Master's Theses
Traffic Engineering (TE) attempts to establish paths for the flow of data in a network so as to optimize the resource utilization and maximize the network performance. One of the main goals of Traffic Engineering is to bring about efficient and reliable network operations. Constraint based routing is the key to Multiprotocol label switching TE. Constraint based routing helps to manage traffic paths within a MPLS network and allows for traffic to flow along certain desired paths. MPLS also supports explicit routing thus providing TE capabilities. MPLS TE enables resiliency and reliability to be built into networks, thus increasing the …
Long Term Pressure Behavior In Turbidite Reservoirs, Feng Wang
Long Term Pressure Behavior In Turbidite Reservoirs, Feng Wang
LSU Doctoral Dissertations
In this study, we investigated several possible mechanisms that would give rise to the anomalous pressure behavior (early concave-up on Horner plot or upward drift on the derivative curve of the log-log plot and asymmetry between the pressure drawdown and buildup behavior) sometimes encountered in the turbidite reservoirs in GOM primarily using numerical simulation and 2-level experimental designs. We ascertained the most influential parameters to the pressure behavior and identified that multilayer commingled system and the leaky compartment model are the most probable mechanisms to cause the anomalous behavior due to layer or zone property contrast to a certain degree. …
Modeling Destination Choice And Measuring The Transferability Of Hurricane Evacuation Patterns, Naveen Kumar Modali
Modeling Destination Choice And Measuring The Transferability Of Hurricane Evacuation Patterns, Naveen Kumar Modali
LSU Master's Theses
In this study a gravity model was used to model destination choice during a hurricane evacuation. Hurricane Floyd data was used to calibrate and apply the gravity model. Two different models were generated for different destination types; home of friends/relative and hotels and motels are the two different destination types for which the models were generated. The performance of the gravity model was tested by comparing the observed and estimated OD matrices using the chi-squared test. The results have indicated that gravity model developed in this study can successfully reproduce the observed trip destinations during a hurricane evacuation The Floyd …
Two Dimensional Sediment Transport Model Using Parallel Computers, Vikas Singh
Two Dimensional Sediment Transport Model Using Parallel Computers, Vikas Singh
LSU Master's Theses
Management and development of water bodies is vital for meeting domestic, agricultural, energy and industrial needs. To that end, dams, artificial channels, lakes and other water structures have been constructed. Management and development of these structures encounter problems of land erosion, reservoir silting, and degradation and aggradation of channel beds, which need to be addressed. Fundamental to these problems are sediment transport, erosion and deposition. Numerical modeling of sediment transport is the best tool to simulate sediment transport in a water body. This study develops a vertically integrated two-dimensional numerical sediment transport model. Sediment transport is simulated in two parts …
Spatial And Temporal Estimation Of Pumping And Recharge In Groundwater System Analysis, Sherly Hartono
Spatial And Temporal Estimation Of Pumping And Recharge In Groundwater System Analysis, Sherly Hartono
LSU Doctoral Dissertations
In many parts of the U.S., groundwater is used as the primary or secondary source of water for the public supply, agricultural, and industrial sectors. In southwestern Louisiana, a majority of the water demand is supplied by the Chicot aquifer. Numerical flow models are useful for managing and optimizing groundwater systems. However, many important model parameters are difficult to quantify, exhibit a certain degree of uncertainty, and may vary both spatially and temporally. Two of the most important and sensitive parameters for a regional groundwater model of the Chicot aquifer are pumping rates and recharge. The use of GIS-based methods …
Power And Memory Optimization Techniques In Embedded Systems Design, Atef Khalil Allam
Power And Memory Optimization Techniques In Embedded Systems Design, Atef Khalil Allam
LSU Doctoral Dissertations
Embedded systems incur tight constraints on power consumption and memory (which impacts size) in addition to other constraints such as weight and cost. This dissertation addresses two key factors in embedded system design, namely minimization of power consumption and memory requirement. The first part of this dissertation considers the problem of optimizing power consumption (peak power as well as average power) in high-level synthesis (HLS). The second part deals with memory usage optimization mainly targeting a restricted class of computations expressed as loops accessing large data arrays that arises in scientific computing such as the coupled cluster and configuration interaction …
Photocatalysis In A Novel Semiconducting Optical Fiber Monolithic Reactor For Wastewater Treatment, Hongfei Lin
Photocatalysis In A Novel Semiconducting Optical Fiber Monolithic Reactor For Wastewater Treatment, Hongfei Lin
LSU Doctoral Dissertations
The development of photocatalytic reactors is essential for the successful exploitation of heterogeneous photocatalysis on semiconductor particles, which has been shown to be an effective means of removing organic pollutants from wastewater streams. In this dissertation, a novel photocatalytic optical fiber monolith reactor (OFMR), which employed a ceramic multi-channel monolith as a support for TiO2 and quartz fibers inserted inside the monolithic channels as both a light-transmitting conductor and a support for TiO2, was developed for wastewater treatment by investigating the photocatalytic degradation of o-dichlorobenzene (DCB) and phenanthrene (PHE). This configuration provides a high surface area for catalyst coating per …
Speciation, Equilibria And Kinetics For Rainfall-Runoff Metals In Adsorptive-Filtration Unit Operations And Processes, Tianpeng Guo
Speciation, Equilibria And Kinetics For Rainfall-Runoff Metals In Adsorptive-Filtration Unit Operations And Processes, Tianpeng Guo
LSU Doctoral Dissertations
Populations transferred by rainfall runoff can have many adverse effects livings and people. Treatment of rainfall-runoff continues to pose unique challenges due to the unsteady nature of processes including mobilization, partitioning and transport of heavy metals as well as other constituent loads. BMPs that incorporate heavy metal removal are generating more attention as the nature of stormwater is better understood. This dissertation focused on metal partitioning and speciation in rainfall-runoff through the in-situ Partial Exfiltration Reactor (PER) and exposed to various redox circumstances, and metal removal by sorptive engineered manganese oxides coated media. Adsorption capacity of three manganese oxides coated …
Hierarchical Indexing For Region Based Image Retrieval, Eka Aulia
Hierarchical Indexing For Region Based Image Retrieval, Eka Aulia
LSU Master's Theses
Region-based image retrieval system has been an active research area. In this study we developed an improved region-based image retrieval system. The system applies image segmentation to divide an image into discrete regions, which if the segmentation is ideal, correspond to objects. The focus of this research is to improve the capture of regions so as to enhance indexing and retrieval performance and also to provide a better similarity distance computation. During image segmentation, we developed a modified k-means clustering algorithm for image retrieval where hierarchical clustering algorithm is used to generate the initial number of clusters and the cluster …
Transform Techniques And Non-Stationarity With An Emphasis On Network Applications, Phat Piron
Transform Techniques And Non-Stationarity With An Emphasis On Network Applications, Phat Piron
LSU Master's Theses
The recent years brought a phenomenal development of Internet. It is, therefore, important to find some ways to improve the performances. The first step in this direction is the characterization and modeling of the network traffic. It has been tested that the network traffic behaves like a self-similar process, while packets interarrivals time possess the long-range dependence property. In particular, we model them by using fractional Brownian motion and fractional Gaussian noise, respectively. Note that, the former is just the cumulative sum of the latter. By using these concepts, the traffic characterization reduces to the estimation of one value: the …
Effect Of Multiuser Interference On Subscriber Location In Cdma Networks, Rohit Sharma
Effect Of Multiuser Interference On Subscriber Location In Cdma Networks, Rohit Sharma
LSU Master's Theses
The last few years have witnessed an ever growing interest in the field of mobile location systems for cellular systems. The motivation is the series of regulations passed by Federal Communications Commission, requiring that wireless service providers support a mobile telephone callback feature and cell site location mechanism. A further application of the location technology is in the rapidly emerging field of intelligent transportation systems, which are intended to enhance highway safety, location based billing etc. Many of the existing location technologies use GPS and its derivatives which require a specialized subscriber equipment. This is not feasible for popular use, …
Experimental And Numerical Study Of Feeding Channel In Proton Exchange Membrane Fuel Cell, Abul Bashar Mahmud Hasan
Experimental And Numerical Study Of Feeding Channel In Proton Exchange Membrane Fuel Cell, Abul Bashar Mahmud Hasan
LSU Master's Theses
The performance of a Proton Exchange Membrane Fuel Cell (PEMFC) using different feeding configurations has been studied, with a focus on the water flooding due to electrochemical reaction. Feeding channel or Bipolar plate in Proton Exchange Fuel Cell is a dominating part. As feeding channel keeps direct contact with the gas diffusion layer, it helps efficiently supplying fuel and air into the gas diffusion layer for efficient production of electricity. Experimental data have been taken at hydrogen flow rates of 20,40,60,80,100 sccm for various bipolar plate arrangements. Three bipolar plates, namely serpentine, straight channel and interdigitated designs, were arranged in …
Augmented Watermarking, Kiranmayi Penumarthi
Augmented Watermarking, Kiranmayi Penumarthi
LSU Master's Theses
This thesis provides an augmented watermarking technique wherein noise is based on the watermark added to the watermarked image so that only the end user who has the key for embedding the watermark can both remove the noise and watermark to get a final clear image. The recovery for different values of noise is observed. This system may be implemented as a basic digital rights management system by defining a regime of partial rights using overlaid watermarks, together with respectively added layers of noise, in which the rights of the users define the precision with which the signals may be …
Scalable Schemes Against Distributed Denial Of Service Attacks, Kishori Nanduri
Scalable Schemes Against Distributed Denial Of Service Attacks, Kishori Nanduri
LSU Master's Theses
Defense against Distributed Denial of Service (DDoS) attacks is one of the primary concerns on the Internet today. DDoS attacks are difficult to prevent because of the open, interconnected nature of the Internet and its underlying protocols, which can be used in several ways to deny service. Attackers hide their identity by using third parties such as private chat channels on IRC (Internet Relay Chat). They also insert false return IP address, spoofing, in a packet which makes it difficult for the victim to determine the packet's origin. We propose three novel and realistic traceback mechanisms which offer many advantages …
Synthesis And Characterization Of Cobalt-Platinum Thin Films, Priya David
Synthesis And Characterization Of Cobalt-Platinum Thin Films, Priya David
LSU Master's Theses
Co-based alloy thin films have attracted a lot of interest, due to their excellent magnetic properties, that is essential in the field of magnetic recording media. Alloying Co with metals like Pt changes some of its intrinsic magnetic properties such as increasing the magnetocrystalline anisotropy constants of the alloy. Co-Pt thin films and multilayers are more suitable for ultra high-density magnetic recording media because they have high-magnetic anisotropy, chemical stability, excellent coercivity and resistance to corrosion. In the present study, Co-Pt alloy and Pt/Co multilayered films were deposited on Si substrate using dual electron beam co-evaporation. The Co-Pt alloy thin …
Experimental Sloshing Studies In Sway And Heave Base Excited Square Tanks, Wei Peng
Experimental Sloshing Studies In Sway And Heave Base Excited Square Tanks, Wei Peng
LSU Master's Theses
In this thesis, free-surface water waves are experimentally investigated with a focus on sloshing in tanks. The sloshing problem is selected for its relatively simple geometry, yet it captures the features of nonlinearities including wave breaking. Free-surface motions are monitored in a square tank with base dimensions of 1 x 1 m2. Sloshing motions have been studied both off- and at resonance in shallow to deep water to investigate nonlinear free surface effects. The tank has been prescribed to move in sway and / or heave excitation. Interesting hysteresis behavior at the surface is captured at and near resonance. Faraday …
Multiphase Mechanisms And Fluid Dynamics In Gas Injection Enhanced Oil Recovery Processes, Madhav M. Kulkarni
Multiphase Mechanisms And Fluid Dynamics In Gas Injection Enhanced Oil Recovery Processes, Madhav M. Kulkarni
LSU Doctoral Dissertations
Currently, the Water-Alternating-Gas (WAG) process is the most widely practiced horizontal mode gas injection process in the industry. Although this process is conceptually sound, it has resulted in low (5 – 10%) oil field recoveries. Conversely, the gravity stable mode of gas injection has carved its niche as one of the most effective methods of gas injection EOR in the dipping reservoirs and pinnacle reefs. The Gas Assisted Gravity Drainage (GAGD) process is therefore being developed at LSU to extend these highly successful gravity stable applications to horizontal type reservoirs. The dissertation attempts to address six key questions: (i) do …
Supercritical Fluid Extraction Of Rice Bran With Adsorption On Rice Hull Ash, Paresh Manilal Patel
Supercritical Fluid Extraction Of Rice Bran With Adsorption On Rice Hull Ash, Paresh Manilal Patel
LSU Doctoral Dissertations
Rice bran oil was extracted using environmentally-friendly supercritical carbon dioxide at varying conditions. Experimental treatments included pressure (27.6, 41.4 and 55.2 MPa), temperature (40 and 60 oC) and flow rates (25, 45 and 65 g/min) of supercritical carbon dioxide. Extracts collected at different time intervals during 4-hour extraction runs in a 3-L extractor were analyzed for oil yield and antioxidants. Normal-phase HPLC was used for analyzing the extract for important antioxidant compounds of oryzanol, tocopherols, tocotrienols. Silica rich rice hull ash adsorbent was also incorporated in combined extraction-adsorption experiments under similar supercritical fluid conditions. Supercritical extraction yields of rice bran …
Modeling And Experimentation Of Drying Of Adipose Derived Adult Stem Cells, Surbhi Mittal
Modeling And Experimentation Of Drying Of Adipose Derived Adult Stem Cells, Surbhi Mittal
LSU Master's Theses
Development of protocols for storing desiccated cells at ambient temperatures offers tremendous economic and practical advantages over traditional storage procedures such as cryopreservation and freeze-drying. An integrated frame work of experimentation and modeling is adopted in the present work to develop procedures for storage of adult stem cells at ambient temperature. As a first step, we have measured the post-rehydration membrane integrity of two passages, Passage-0 (P0) and Passage-1 (P1), of human adipose-derived stem cells (hASCs). hASCs were dried using a convective stage at three different drying rates (slow, moderate and rapid) in D-PBS with trehalose (50 mM) and glycerol …
Advanced Grid Stiffened Composite Structures, Dinesh Maricherla
Advanced Grid Stiffened Composite Structures, Dinesh Maricherla
LSU Master's Theses
In this study Advanced Grid Stiffened (AGS) composite structures are developed and analyzed for their mechanical properties. It is widely known that these structures possess light weight, high strength, and inherent impact resistance. Because of the advantages mentioned above, the AGS composite structures find many applications in aerospace, ship building and construction industries. The purpose of this study is to manufacture AGS composite structures and analyze AGS composite structures as reinforcement members. A FEA model is also developed and validated with the test results. Parametric analysis is also conducted to investigate the effects of different design parameters on these structures. …
Pah And Pcb Distribution In Sediment Fractions And Sorptive Phases, Trudy J. Estes
Pah And Pcb Distribution In Sediment Fractions And Sorptive Phases, Trudy J. Estes
LSU Doctoral Dissertations
Contaminant distribution is integral to environmental evaluations of contaminated sediment on every level. The technical and economic feasibility of treatment or beneficial use is a function of the accessibility or separability of the contaminants within the sediment. The magnitude of release to the environment during dredging and disposal is dependent upon the partitioning behavior of the contaminants. Yet, little attention has been paid to contaminant distribution in the fine sediment fractions. Further, conventional distribution coefficients provide little information regarding the relative contaminant loading of each of the sorptive phases. Bioavailability of contaminants in oil and grease, soot and organic carbon, …