Engineering Commons^™

Enhanced Na+/H+ Exchange During Ischemia And Reperfusion Impairs Mitochondrial Bioenergetics And Myocardial Function, Mohammed Aldakkak, David F. Stowe, James S. Heisner, Marisha Spence, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Inhibition of Na+/H+ exchange (NHE) during ischemia reduces cardiac injury due to reduced reverse mode Na+/Ca2+ exchange. We hypothesized that activating NHE-1 at buffer pH 8 during ischemia increases mitochondrial oxidation, Ca2+ overload, and reactive O2 species (ROS) levels and worsens functional recovery in isolated hearts and that NHE inhibition reverses these effects. Guinea pig hearts were perfused with buffer at pH 7.4 (control) or pH 8 +/- NHE inhibitor eniporide for 10 minutes before and for 10 minutes after 35- minute ischemia and then for 110 minutes with pH 7.4 buffer alone. Mitochondrial NADH and FAD, [Ca2+], and superoxide …

The Power Flow Angle Of Acoustic Waves In Thin Piezoelectric Plates, Iren E. Kuznetsova, Boris D. Zaitsev, Andrei A. Teplykh, Shrinivas Joshi, Anastasia S. Kuznetsova

Electrical and Computer Engineering Faculty Research and Publications

The curves of slowness and power flow angle (PFA) of quasi-antisymmetric (A0) and quasi-symmetric (S0) Lamb waves as well as quasi-shear-horizontal (SH0) acoustic waves in thin plates of lithium niobate and potassium niobate of X-,Y-, and Z-cuts for various propagation directions and the influence of electrical shorting of one plate surface on these curves and PFA have been theoretically investigated. It has been found that the group velocity of such waves does not coincide with the phase velocity for the most directions of propagation. It has been also shown that S0 and SH0 wave are characterized by record high values …

Analysis And Design Of Multiphase Multi-Interleave Dc-Dc Converter With Input-Output Bypass Capacitor, Furqan Mubashir Saleemi

Master's Theses

The power requirements for the microprocessor have been increasing as per Moore's Law. According to International Technology Roadmap (ITRS), the Voltage Regulator Module (VRM) for the microprocessor will be 200 W(with 1V, 200A output) in 2010. With the VRMs topology of synchronous buck, serious technical challenges such as small duty cycle, high switching frequencies, and higher current demands, contribute to decreased power density and increased cost. This thesis proposes a Multiphase Multi-Interleave Buck topology to solve the technical challenges of powering future microprocessors. The critical design parameter values are selected using the theoretical design equations and calculations. The design is …

Low-Flow Perfusion Of Guinea Pig Isolated Hearts With 26°C Air-Saturated Lifor Solution For 20 Hours Preserves Function And Metabolism, David F. Stowe, Amadou K.S. Camara, James S. Heisner, Mohammed Aldakkak, David R. Harder

Biomedical Engineering Faculty Research and Publications

Background

Donor human hearts cannot be preserved for >5 hours between explantation and recipient implantation. A better approach is needed to preserve transplantable hearts for longer periods, ideally at ambient conditions for transport. We tested whether Lifor solution could satisfactorily preserve guinea pig isolated hearts perfused at low flow with no added oxygen at room temperature for 20 hours.

Methods

Hearts were isolated from 18 guinea pigs and perfused initially with oxygenated Krebs–Ringer (KR) solution at 37°C. Hearts were then perfused with recirculated Lifor or cardioplegia (CP) solution (K⁺ 15 mmol/liter) equilibrated with room air at 20% of control …

Service Supply Chain Management : A Hierarchical Decision Modeling Approach, Roger Angel Solano-Cayama

Dissertations

A Service Supply Chain (SSC) may be described as a network of service provider facilities (in-house or outsourced), each of which is able to process one or more service tasks on an as needed basis. Two key characteristics of a SSC are (i) the business service is decomposable into several sequential tasks that can be processed by different service providers, and (ii) the primary capacity resource is skilled labor. SSCs are increasingly being developed by companies that experience a high variability of demand for their services (e.g., loan processing, analytical consulting services, emergency repair crews, claims processing, etc.). Typically, the …

Investigation Into The Acupuncture And Meridian System, Jingong Pan

Dissertations

The Meridian system conceived by the ancient Chinese has been described and referenced for more than a thousand years. The Meridians meaning paths are the main trunks that run longitudinally within the body. The Meridian system consists of about 400 acupuncture nodes and 20 Meridian channels connecting most of these points. It deals with the routing and distribution of certain signals that may affect physiological functions. It integrates meridians, tissues and organs into a complex system.

Initially, modeling of the acupuncture system is investigated. The physical effect of injecting an acupuncture needle at a node is suggested by an equivalent …

Modeling Edge Effects Of Mesa Diodes For Silicon Photovoltaics, Jesse S. Appel

Dissertations

A mesa diode has been modeled and its performance under dark and illuminated conditions has been simulated using a commercial finite element software package. These simulations have led to a determination of the self-consistent solution to the continuity equations for electrons and holes using the steady-state drift-diffusion model for carrier dynamics coupled with electric potential determined from Poisson's equation. The purpose of these simulations has been to determine the influence of edge conditions on the overall performance of mesa diodes under dark and illuminated conditions.

Mesa diode arrays are fabricated on crystalline silicon solar cells. They are an array of …

Probing Spin, Charge And Lattice Coupling In Manganites, Zhiqiang Chen

Dissertations

Complex oxides such as the manganites exhibit an intimate coupling of the electron spin, charge and lattice degrees of freedom. The characteristic feature of these materials is the existence of a ground state topology with many closely lying minima. The system can be switched from one minimum to another by the application of external parameters such as strain, temperature, magnetic fields, or electrical fields. These materials thus exhibit large responses to these external parameters and can be used as novel sensors in data storage and other applications. Understanding the couplings will have an impact on the fundamental science of highly …

Novel Polypropylene Based Microporous Membranes Via Spherulitic Deformation, Kuan-Yin Lin

Dissertations

A novel method for creating a microporous polypropylene membrane via spherulitic deformation is described. The microporous structure was generated by the combination of intra-spherulitic and inter-spherulitic deformations. Polypropylene was selected due to its unique cross-hatched lamellar morphology facilitating inter-spherulitic deformation. A precursor film with a spherulitic structure was made under low-stress melt processing condition. A tangential lamellae-rich spherulite was created and identified with a positive birefringence sign. A sequential annealing process improved the crystalline structure, and in particular the thickness of the tangential lamellae. The annealing process proved to be critical for initiating the inter-spherulitic deformation. The post-extrusion process conditions …

Ionic Liquids As Additives For Biodegradable Polyactic Acid, Ku-Il Park

Dissertations

In this study, two ionic liquids (IL) with different anions (decanoate, tetrafluoroborate) but with the same phosphonium based cation were evaluated as potential plasticizers and lubricants for polylactic acid (PLA) and also for their effects on its hydrolytic and thermal degradation. Both ILs at 5wt% were well dispersible and partly miscible with PLA as evidenced by scanning electron microscopy/energy dispersive x-ray scattering, SEMIEDX, and glass transition temperature, T_g, characterization, as well as from solubility parameters calculations.

The effects of the IL containing a decanoate anion were more pronounced on lubrication and degradation as evidenced by reduced melt viscosities …

Multi-Functional, Self-Sensing And Automated Real-Time Non-Contact Liquid Dispensing System, Qiong Shen

Dissertations

Liquid dispensing in the order of pico-liter has become more and more important in biology, electronics and micro-electronic-mechanical-system (MEMS) during the past two decades due to the rapid progress of researches on the deoxyribonucleic acid (DNA) microarray, compact and low-cost direct write technology (DWT), organic semiconductors and nano-particles.

The existing approaches, commercialized or experimental, to liquid dispensing in minute amounts have one common shortcoming: open loop control, i.e., they have no direct control on the quality of dispensed liquid. In contrast, the SmartPin has intrinsic self-sensing capability to not only control the process of liquid dispensing, but also the results …

Degradation Of Polylactic Acid In The Presence Of Microsize And Nanosize Fillers, Quyuan Zhou

Dissertations

Polylactide (PLA)-cationic (montmorillonite, MMT) and anionic (hydrotalcite, HT) clay micro- or nanocomposites based on semicrystalline and amorphous polymers and unmodified and organomodified as well as calcined or non-calcined clays at 5wt% concentration are produced by melt mixing. Depending on the clay type, presence of organomodifiers and calcination, micro- or nanocomposites are produced, as confirmed by XRD and SEM analysis.

Unfilled polymers and their composites are subjected to isothermal degradation in air at 180°C and 200°C. Degradation rate constants are calculated from novel equations incorporating IV. Results show that the thermal degradation rate constants of the amorphous PLA and its composites …

Synthesis And Characterization Of Atmospheric Pressure Chemically Vapor Deposited Aluminum, Sipeng Gu

Dissertations

This study investigates the use of atmospheric pressure chemical vapor deposition (APCVD) to produce high quality aluminum coatings for corrosion protection of steel. The coatings were produced through thermal decomposition of tri-isobutyl-aluminum (TIBAL) over the 275 to 300°C temperature range. Under optimal deposition conditions, growth rates as high as 1.2 um/min were achieved. X-ray photoelectron spectroscopy, auger electron spectroscopy, glow discharge optical emission spectroscopy and nuclear reaction analysis revealed that the coatings consisted essentially of pure aluminum (~99 at.%) with oxygen and carbon present as minor constituents. The coatings were characterized in terms of their morphological, structural, electrical, and mechanical …

Biomechanical Testing Of Upright Range Of Motion Versus Overhead Supine Range Of Motion, Linda Uko

Theses

Rehabilitation of an elbow, following injury, is not a well-studied subject. Clinically, there is not a general consensus on which recovery method is optimal for healing an unstable elbow. When dealing with medial collateral ligament deficiency, many authors have proposed several forearm positions that will yield proper healing of the unstable elbow. Some researchers believe that active mobilization of the elbow with the arm in a vertical position is a safe protocol for rehabilitation with the forearm oriented in a supine pronated position. It was also mentioned that the compressive forces due to the active mobilization of the arm will …

A Two Dimensional Model Of Magnetic Field Assisted Assembly, Gaurev Devrani

Theses

A simplified model to simulate the magnetic field distribution for applications in magnetic field assisted assembly of semiconductor device structures, using commercial software (Vizimag), has been implemented. Solenoids have been utilized to serve as electromagnets that are responsible for the assembly process. Magnetic shielding techniques have been deployed to isolate the influence of one solenoid over another. These solenoids are used to move the devices that need to be placed in recesses within the substrate. The bottom of the devices and the recesses are coated with magnetic materials to facilitate the movement and placement of devices within the recesses in …

Precipitation Of Ultrafine Particles Using Liquid Antisolvent With Concentric Ultrasonic Nozzle And Subcritical Co2, Satya Chaitanya Kunchala

Theses

Nanotechnology has become more relevant in the pharmaceutical industry. Almost 40% of the drugs developed by pharmaceutical industries are poorly soluble in water which limits the bioavailability of these drugs in body fluids. Hence, it is necessary to reduce the particle size, which increases the interfacial surface area. This work focuses on micronization of class ii drug Griseofulvin which is poorly water soluble. Two processes namely, liquid antisolvent precipitation using ultrasonic nozzle and other process using subcritical CO₂ have been used to produce ultrafine particles of this drug.

In liquid antisolvent precipitation, a combination of ultrasound, polymer and surfactant …

Classification Of Hand Held Shapes And Locations In Continuous Signing, Swetha Karri

Theses

Sign language for the deaf and hearing impaired replaces speech with manually produced signs. Each sign has been categorized as being combinations of handshape, movement, orientation, location, and facial expressions. Of the five sign parameters, this thesis focuses on classification of two of the main parameters, the hand shapes and locations, in continuous signing.

Since the nature of hand shapes is transient and not static, neural networks was used as a classifier for hand shapes. And since locations in sign language are defined by linguistic variables rather than by hard core position values, fuzzy logic was used as a classifier …

Experimental Investigation Of The Effect Of Sonication On The Precipitation Of Grieseofluvin By Impinging Jets, Ankit H. Patel

Theses

Almost 80% of drugs on the market are manufactured as solid dosage forms, such as tablets. Drug bioavailability increases as the particle size decreases and the surface area per unit volume of drug increases. Therefore, there is a keen interest by the pharmaceutical industry to develop techniques that can be used to manufacture particles of active pharmaceutical ingredients (API) in the nano/micro particle range. Impinging jets is one of the most promising techniques to do so.

In this work, a submerged impinging jet system coupled with an ultrasonic probe (sonicator) was used to precipitate Griseofulvin, a common, poorly water-soluble antifungal …

Photoplethysmorgraph-Derived Respiration, Priyanka Pankaj Shah

Theses

Stress & Motivated Behavioral Institute (SMBI) has developed a research program to provide an objective evaluation of the physiological and neurocognitive impact of human electromuscular muscular interference (HEMI) devices in humans. The initial step is to understand their physiological impact, which is characterized by vital signs. Volunteers are recruited from HEMI training programs with the provision that data collection can not interfere with training. Thus, an ambulatory system was assembled. There are two main issues in the current ambulatory system, one of which is the reliability of the respiration signal obtained using a strain gauge respiration band, mainly due to …

Design And Fabrication Of A Microneedle For The Implantation Of Floating Microstimulators, Faysal Ahmed

Theses

Neural prosthetics are used to stimulate any remaining functional nervous tissue in order to restore function in visual, auditory, or other physiological components associated with the nervous system. Microelectrodes have been used in stimulating and detecting electrical activity in neurons. When stimulating or recording neural tissue activity using microelectrodes, there are usually many problems and difficulties in obtaining the correct functionality and results. There is great difficulty in placing these microelectrodes in a specific location in the central nervous system due to various problems with the methodology used. Many different techniques such as the traditional interconnected microelectrodes have been an …

Dem Simulated Radial And Axial Pressure In A Cylindrical Granular Column, Meng Cui

Theses

The study of packed beds of granular spheres and their applications are of great interest to industries, and one of the most important subjects that has been studied is cylindrical beds. In 1895, H. A. Janssen discovered that in a vertical cylinder the pressure measured at the bottom does not depend upon the height of the filling in contrast to Newtonian fluids that possess linear hydrostatic pressure equilibrium. One of assumptions of his theory stated that the horizontal pressure is proportional to the vertical. In this thesis, this physical hypothesis is investigated using Discrete Element Simulations of inelastic with a …

Approach To Model On The Fourth Generation Port Competitiveness : An Application For Pda, Yiwen Cao

World Maritime University Dissertations

No abstract provided.

Research On The Feasibility And Necessity Of Finance Logistics Outsourcing In China, Junwei Chen

World Maritime University Dissertations

No abstract provided.

Research On Logistic Management In Deltai Medical Company, Yan Hu

World Maritime University Dissertations

No abstract provided.

Research On Information Integration Of Zhoushan Port And Its External Environment, Peiyao Lu

World Maritime University Dissertations

No abstract provided.

The Research On Container Operations At Container Freight Station And Rfid Implementation, Kasarla Naga Chandra Mohan

World Maritime University Dissertations

No abstract provided.

The Development Research On Chinese Railway Logistics, Yuanyuan Zhang

World Maritime University Dissertations

No abstract provided.

The Development Research On Zhoushan Shipbuilding And Ship Repair Industry, Jing Zhou

World Maritime University Dissertations

No abstract provided.

Electrochemical Reductive Behaviors Of 3,4,5,6-Tetrachloro-2-Trichloromethylpyridine At Ag Electrode, Chun-An Ma, Yi-Jiao Hu, Ying-Hua Xu

Journal of Electrochemistry

The electrochemical reductive behavior of 3,4,5,6-tetrachloro-2-trichloropyridine(heptachloropyridine) on silver electrode in the mixture of acetonitrile and water solutions containing TBAP was investigated by cyclic voltammetry.The influences of scan rate,concentration and temperature on the electrochemical behavior were discussed.It was shown that the reduction of heptachloropyridine on the silver electrode was a diffusion-controlled irreversible process.The diffusion coefficient of heptachloropyridine in the acetonitrile solution was 3.0×10^-5 cm²/s.The mechanism of the dechloration of 3,4,5,6-tetrachloro-2-trichloropyridine was also discussed.

Interoperability Measurement, Thomas C. Ford

Theses and Dissertations

This research presents an inaugural general method of measuring the collaborative and confrontational interoperability of a heterogeneous set of systems in the context of an operational process. The method is holistic, fundamental, flexible, and mathematical in nature and accommodates all types of systems and interoperations. The method relates the interoperability measurement to measures of operational effectiveness for confrontational operational processes. Extant leveling methods of describing interoperability are shown to be a special case of the more general method given in this research and the general interoperability measurement method is demonstrated through the presentation of coalition interoperability, suppression of enemy air …