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A Portable Phonatory Feedback Device For Patients With Speech Disorders, Richie Sajan 2010 Louisiana State University and Agricultural and Mechanical College

A Portable Phonatory Feedback Device For Patients With Speech Disorders, Richie Sajan

LSU Master's Theses

Vocal intensity-related speech disorders such as dysarthria and vocal nodules can limit quality of life and reduce the patient’s ability to interact with family, socialize, or pursue employment. Behavioral speech therapies exist to address these issues but have limited effectiveness because they are expensive and clinic-based. The ability to monitor vocal intensity outside of the clinical setting will greatly aid in the treatment of these speech disorders, enabling patients to make quicker progress by reinforcing techniques learned in the clinic. The Voice Volume Monitor (VVM) is a portable and cost-effective therapeutic aid designed for this purpose, providing real-time feedback ...


Optimum Design Of Cable-Stayed Bridges, Mahmoud M. Hassan 2010 Western University

Optimum Design Of Cable-Stayed Bridges, Mahmoud M. Hassan

Digitized Theses

Owing to their excellent structural characteristics, aesthetic appearance, low maintenance cost, and efficient use of structural materials, cable-stayed bridges have gained much popularity in recent decades. Stay cables of a cable stayed bridge are post-tensioned to counteract the effect of the bridge dead load. The solution for an optimum distribution of post-tensioning cable forces is considered one of the most important and difficult tasks in the design of cable-stayed bridges. A novel approach that utilizes the finite element method, B-spline curves, and real coded genetic algorithm to determine the global optimum post-tensioning cable forces is developed. The effect of geometric ...


Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng 2010 North Carolina State University

Sodium Hydroxide Pretreatment And Enzymatic Hydrolysis Of Coastal Bermuda Grass, Ziyu Wang, Deepak R. Keshwani, Arthur P. Redding, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Coastal Bermuda grass was pretreated with NaOH at concentrations from 0.5% to 3% (w/v) for a residence time from 15 to 90 min at 121 °C. The pretreatments were evaluated based on total lignin removal and production of total reducing sugars, glucose and xylose from enzymatic hydrolysis of the pretreated biomass. Up to 86% lignin removal was observed. The optimal NaOH pretreatment conditions at 121 °C for total reducing sugars production as well as glucose and xylose yields are 15 min and 0.75% NaOH. Under these optimal pretreatment conditions, total reducing sugars yield was about 71% of ...


Ultrasound-Assisted Osmotic Dehydration Of Strawberries: Effect Of Pretreatment Time And Ultrasonic Frequency, Juan Garcia-Noguera, Francisca I. P. Oliveira, Maria Izabel Gallão, Curtis L. Weller, Sueli Rodrigues, Fabiano A. N. Fernandes 2010 University of Nebraska-Lincoln

Ultrasound-Assisted Osmotic Dehydration Of Strawberries: Effect Of Pretreatment Time And Ultrasonic Frequency, Juan Garcia-Noguera, Francisca I. P. Oliveira, Maria Izabel Gallão, Curtis L. Weller, Sueli Rodrigues, Fabiano A. N. Fernandes

Biological Systems Engineering: Papers and Publications

Pretreatment of fruits prior to drying has shown success in reducing drying time and costs. In this work, ultrasound-assisted osmotic dehydration has been implemented as a method to increase water diffusivity and reduce drying time in strawberries. Strawberry halves were immersed in distilled water and in two different concentrations of sucrose solutions while pretreatment time and ultrasonic frequency levels were varied to determine their effect on drying time, water loss, and soluble solids gain. A microscopic analysis was carried out to evaluate the formation of microchannels and other changes to the fruit tissue structure. Greater sucrose concentration used in ultrasound- ...


Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang 2010 University of Nebraska–Lincoln

Cytocompatible Cross-Linking Of Electrospun Zein Fibers For The Development Of Water-Stable Tissue Engineering Scaffolds, Quiran Jiang, Narendra Reddy, Yiqi Yang

Biological Systems Engineering: Papers and Publications

This paper reports a new method of cross-linking electrospun zein fibers using citric acid as a non-toxic cross-linker to enhance the water stability and cytocompatibility of zein fibers for tissue engineering and other medical applications. The electrospun structure has many advantages over other types of structures and protein-based biomaterials possess unique properties preferred for tissue engineering and other medical applications. However, ultrafine fiber matrices developed from proteins have poor mechanical properties and morphological stability in the aqueous environments required for medical applications. Efforts have been made to improve the water stability of electrospun protein scaffolds using cross-linking and other approaches ...


Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng 2010 University of Nebraska-Lincoln

Microwave-Based Alkali Pretreatment Of Switchgrass And Coastal Bermudagrass For Bioethanol Production, Deepak R. Keshwani, Jay J. Cheng

Biological Systems Engineering: Papers and Publications

Switchgrass and coastal bermudagrass are promising lignocellulosic feedstocks for bioethanol production. However, pretreatment of lignocelluloses is required to improve production of fermentable sugars from enzymatic hydrolysis. Microwave- based alkali pretreatment of switchgrass and coastal bermudagrass was investigated in this study. Pretreatments were carried out by immersing the biomass in dilute alkali reagents and exposing the slurry to microwave radiation at 250 W for residence times ranging from 5 to 20 min. Simons’ stain method was used to quantify changes in biomass porosity as a result of the pretreatment. Pretreatments were evaluated based on yields of total reducing sugars, glucose, and ...


Using A Vision Sensor System For Performance Testing Of Satellite-Based Tractor Auto-Guidance, Dwight Easterly, Viacheslav I. Adamchuk, Michael F. Kocher, Roger M. Hoy 2010 University of Nebraska-Lincoln

Using A Vision Sensor System For Performance Testing Of Satellite-Based Tractor Auto-Guidance, Dwight Easterly, Viacheslav I. Adamchuk, Michael F. Kocher, Roger M. Hoy

Biological Systems Engineering: Papers and Publications

A vision sensing system for the measurement of auto-guidance pass-to-pass and long-term errors was implemented to test the steering performance of tractors equipped with auto-guidance systems. The developed test system consisted of an optical machine vision sensor rigidly mounted on the rear of the tested tractor. The center of the drawbar hitch pin point was used as the reference from which to measure the deviation of the tractor’s actual travel path from its desired path. The system was built and calibrated to a measurement accuracy of better than 2 mm. To evaluate the sensor, two auto-guidance systems equipped with ...


Net Radiation Dynamics: Performance Of 20 Daily Net Radiation Models As Related To Model Structure And Intricacy In Two Climates, Suat Irmak, Denis Mutiibwa, José O. Payero 2010 University of Nebraska-Lincoln

Net Radiation Dynamics: Performance Of 20 Daily Net Radiation Models As Related To Model Structure And Intricacy In Two Climates, Suat Irmak, Denis Mutiibwa, José O. Payero

Biological Systems Engineering: Papers and Publications

We compared daily net radiation (Rn) estimates from 19 methods with the ASCE‐EWRI Rn estimates in two climates: Clay Center, Nebraska (sub‐humid) and Davis, California (semi‐arid) for the calendar year. The performances of all 20 methods, including the ASCE‐EWRI Rn method, were then evaluated against Rn data measured over a non‐stressed maize canopy during two growing seasons in 2005 and 2006 at Clay Center. Methods differ in terms of inputs, structure, and equation intricacy. Most methods differ in estimating the cloudiness factor, emissivity (α), and calculating net longwave radiation (Rnl ...


Carbon Nanotube Interconnect Modeling For Very Large Scale Integrated Circuits, Yao Xu 2010 Louisiana State University and Agricultural and Mechanical College

Carbon Nanotube Interconnect Modeling For Very Large Scale Integrated Circuits, Yao Xu

LSU Doctoral Dissertations

In this research, we have studied and analyzed the physical and electrical properties of carbon nanotubes. Based on the reported models for current transport behavior in non-ballistic CNT-FETs, we have built a dynamic model for non-ballistic CNT-FETs. We have also extended the surface potential model of a non-ballistic CNT-FET to a ballistic CNT-FET and developed a current transport model for ballistic CNT-FETs. We have studied the current transport in metallic carbon nanotubes. By considering the electron-electron interactions, we have modified two-dimensional fluid model for electron transport to build a semi-classical one-dimensional fluid model to describe the electron transport in carbon ...


Modeling Pm Rotary-Linear Motors With Twin-Stator Using 3d Femm, Oleksandr Dobzhanskyi 2010 Louisiana State University and Agricultural and Mechanical College

Modeling Pm Rotary-Linear Motors With Twin-Stator Using 3d Femm, Oleksandr Dobzhanskyi

LSU Master's Theses

A rapid growth of automatization nowadays requires electric machines to be adjusted to any technological process. Therefore, a need in machines with two degrees of mechanical freedom (TDMF), which can operate rotationally and linearly, is relatively large. This thesis is directed on the design and study of performance of PM (permanent magnet) rotary-linear synchronous motors with twin-armature as a new type of electric machines which can perform linear, rotational and helical movements. Three stator versions are considered, namely: stator with rotary and linear armatures, two rotary armatures, and two linear armatures. The rotors have PMs skewed with respect to the ...


Biomechanical Evaluation Of Modified Track Shoes, Marlon Alberetos Greensword 2010 Louisiana State University and Agricultural and Mechanical College

Biomechanical Evaluation Of Modified Track Shoes, Marlon Alberetos Greensword

LSU Master's Theses

Track and field runners, especially sprinters and mid-distance runners, face many problems due to walking in spike shoes. Due to the fact that track and field spike shoes are designed specifically for running, the runner’s feet remain in an uncomfortable, flexed position when walking between workouts and races. Problems caused by the dangerous foot-positioning include, but are not limited to, the following: back pain, shin splints, bone spurs, blisters, and overall decreased level of running performance. Over time, runners wearing improper footwear for walking may face chronic injuries such as plantar fasciitis, shin splints, Achilles tendinitis, chondromalacia, and iliotibial ...


Adaptive Quantization In Wireless Sensor Networks With Encryption, Niharika Konakalla 2010 Louisiana State University and Agricultural and Mechanical College

Adaptive Quantization In Wireless Sensor Networks With Encryption, Niharika Konakalla

LSU Master's Theses

We consider the estimation of a deterministic unknown parameter in an encrypted wireless sensor networks. Adaptive quantization is used on the sensor's observation and the outputs of the sensors are then encrypted using a probabilistic cipher. In a conventional fixed quantization scheme, estimation error grows exponentially with the difference between the threshold and the unknown parameter to be estimated. Hence, to avoid this, we used and adaptive quantization scheme where each sensor adaptively adjusts its quantization threshold. We find the Cramer-Rao Lower Bound for the Ally Fusion Center (AFC) and then find the optimal estimate of the unknown parameter ...


Integrating Lattice Space-Time Codes Of Highest Rank And Multiplexing Over Rayleigh Fading Channels, Vamshi Krishna Samudrala 2010 Louisiana State University and Agricultural and Mechanical College

Integrating Lattice Space-Time Codes Of Highest Rank And Multiplexing Over Rayleigh Fading Channels, Vamshi Krishna Samudrala

LSU Master's Theses

In this thesis, we consider the problem of finding an optimal combination of multiplexing and space-time coding over a MIMO array when a transmitter has a prior knowledge about correlation. Some existing work in this area used multiplexing and space-time coding methods as a technique to achieve capacity over a MIMO wireless channel. In this work, we consider a 2x2 lattice space-time code of highest rank and multiplex it over a MIMO system to improve the bit error rate performance. The main focus of this thesis is to address the problem of switching between spatial multiplexing and space-time coding to ...


Electron-Electron Scattering In A Double Quantum Dot: Effective Mass Approach, S. Yu. Kruchinin, A. V. Federov, A. V. Baranov, Tatiana Perova, Kevin Berwick 2010 Saint Petersburgh State University of Information Technologies, Mechanics and Optics

Electron-Electron Scattering In A Double Quantum Dot: Effective Mass Approach, S. Yu. Kruchinin, A. V. Federov, A. V. Baranov, Tatiana Perova, Kevin Berwick

Articles

We present a theoretical description of the first-order scattering of interacting electrons and holes in a double quantum dot. Assuming infinitely high walls, strong confinement, and a two-band approximation, we derive general expressions for the two-particle matrix elements of the screened Coulomb potential. We also determine the selection rules for different scattering channels and consider special cases where the corresponding matrix elements can be represented by simple analytical expressions. Numerical calculations of the matrix elements and an analysis of their dependence on the geometrical and material parameters of the double quantum dot have also been performed.


The Size Ellect On The Infrared Spectra Of Condensed Media Under Conditions Of Id, 2d And 3d Dielectric Confinement, Igor I. Shaganov, Tatiana S. Perova, Vasily A. Melnikov, Kevin Berwick 2010 Vavilov State Optical Institute, St. Petersburg

The Size Ellect On The Infrared Spectra Of Condensed Media Under Conditions Of Id, 2d And 3d Dielectric Confinement, Igor I. Shaganov, Tatiana S. Perova, Vasily A. Melnikov, Kevin Berwick

Articles

A general expression for the dielectric loss spectrum of an absorbing composite medium was obtained from a Maxwell-Garnett general equation. This expression was simplified for the cases of one, two and three dimensional dielectric confinement in both ordered and disordered thin layers, rods (wires) and spheres of absorbing medium which are considered as mesoparticles or mesoscopic molecules. This theoretical approach was verified experimentally using high purity organic liquids with strong absorption bands in the infrared range. Three organic liquids, namely benzene, chloroform and carbon disulphide, were measured in various dielectric confinement configurations using Fourier Transform Infrared (FTIR) spectroscopy with a ...


Enhancement Of Single-Lap Joint Strength Under Tension Using Piezoelectric Actuation, Ryan Michael Meyer 2010 Louisiana State University and Agricultural and Mechanical College

Enhancement Of Single-Lap Joint Strength Under Tension Using Piezoelectric Actuation, Ryan Michael Meyer

LSU Master's Theses

Composite adhesively bonded joint structures have seen increased use over conventional riveted due to their ease of manufacturing and quality strength-to-weight ratios. However, adhesively bonded joints lack the rigidity and failure strength of riveted assemblies, due to high stress concentrations which develop in the adhesive layer, which makes them prone to undesirable deformation and failure. Piezoelectric materials feature the ability to produce mechanical strain when subjected to an applied voltage and vice-versa. Therefore, it is proposed to use piezoelectric actuators to transmit counterbalancing forces to increase the rigidity and strength of composite joints. Existing studies have been limited in that ...


Supercritical Pyrolysis Of N-Decane, Sean Bagley 2010 Louisiana State University and Agricultural and Mechanical College

Supercritical Pyrolysis Of N-Decane, Sean Bagley

LSU Doctoral Dissertations

Fuels used in future generations of high-speed jet aircraft will be required to take on increasing heat loads in their role as the primary coolant for the absorption of waste heat from the engine. As a consequence, the hydrocarbon fuels will be exposed to elevated temperatures and pressures prior to their use as fuels, conditions which are beyond the critical point of the fuel and which lead to the formation of carbonaceous solid deposits in the pre-combustion environment.

Deposition of solids causes reduced engine performance and eventual failure, so understanding the mechanisms by which thermally stressed hydrocarbons become solids is ...


Design And Fabrication Of Micronozzles For Drug Delivery Applications, Yuxuan Zhou 2010 Louisiana State University and Agricultural and Mechanical College

Design And Fabrication Of Micronozzles For Drug Delivery Applications, Yuxuan Zhou

LSU Master's Theses

Inhaled drug is an important drug delivery route. It is widely used in medications for respiratory disorders. However, it has some significant limitations, for examples, concentration of drug, output, and particles size, are not accurately controlled in most of the available drug delivery systems today. Various new devices and technologies continue to be developed and introduced. Vibrating orifice is one of them. The critical issue of vibrating orifice technology is the fabrication of micro-nozzles. Traditional technique to fabricate these nozzles is to use dry etching method, which tends to be expensive and inconvenient for mass production. Other two optional fabrication ...


Computational Examination Of Compaction Wave-Boundary Interaction In Granular Explosive, Anirban Mandal 2010 Louisiana State University and Agricultural and Mechanical College

Computational Examination Of Compaction Wave-Boundary Interaction In Granular Explosive, Anirban Mandal

LSU Master's Theses

Interactions between initially planar, piston supported compaction waves in heterogeneous energetic solids and macro-scale rigid boundaries were computationally examined for a wide range of piston impact speeds (20 ≤ Up ≤ 500 m/s) and initial solid volume fractions of the material (0.73 ≤ ϕ0 ≤ 0.90). The response of the material was described by a continuum theory that accounts for both elastic and inelastic compaction in a thermodynamically consistent manner. Initial conditions were imposed by interpolating the spatial structure of one-dimensional steady compaction waves onto two-dimensional domains considered in this study. For a planar wedge boundary, the peak solid ...


Elastohydrodynamic Analysis Of Spur Gears Using Load-Sharing Concept: Running-In And Steady-State, Saleh Akbarzadeh 2010 Louisiana State University and Agricultural and Mechanical College

Elastohydrodynamic Analysis Of Spur Gears Using Load-Sharing Concept: Running-In And Steady-State, Saleh Akbarzadeh

LSU Doctoral Dissertations

Gears are widely used in industry and hence their performance is of vital importance. Under the typical operating conditions of gears, the lubricant layer formed between the teeth of the pinion and the gear cannot completely separate the surfaces and contact of asperities of the pinion and gear occurs. This case is usually referred to as mixed lubrication problem. In this research the load-sharing concept has been employed to predict the performance of the pinion-gear system. The load-sharing concept is an efficient method to solve the mixed lubrication problem and is capable to predict the thickness of the lubricant film ...


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