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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 …

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 …

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 …

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 …

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 …

A Novel Method For Characterization Of Peripheral Nerve Fiber Size Distributions By Group Delay Measurements And Simulated Annealing Optimization, Robert B. Szlavik, Galen E. Turner, Iii

Biomedical Engineering

The ability to determine the characteristics of peripheral nerve fiber size distributions would provide additional information to clinicians for the diagnosis of specific pathologies of the peripheral nervous system. Investigation of these conditions, using electro-diagnostic techniques, is advantageous in the sense that such techniques tend to be minimally invasive yet provide valuable diagnostic information. One of the principal electro-diagnostic tools available to the clinician is the nerve conduction velocity test. While the peripheral nerve conduction velocity test can provide useful information to the clinician regarding the viability of the nerve under study, it is a single parameter test that yields …

Engineered Micro-Environments And Vibrational Culture Systems For Vocal Fold Tissue Engineering, Jaishankar Kutty

All Dissertations

Voice is produced by the conversion of aerodynamic energy from exhalation to acoustical energy for voice production by the vocal folds (membranous connective tissue) located in the larynx. The quality of voice depends on the biomechanical properties of the multi-layered vocal fold tissue which derive from its extracellular matrix (ECM) organization and composition. The wound healing response to vocal fold injuries is characterized by scarring and subsequent dysphonia due to alterations in the biomechanical properties of the tissue.
The work presented here is motivated by the importance of voice in maintaining quality of life and the inability of current treatment …

Inferring Mechanical Resonances In Micro - And Nanocantilevers Using The Harmonic Detection Of Resonance (Hdr) Method To Develop A Novel Sensing Platform, Gayatri Keskar

All Dissertations

During the past two decades, advances in microelectromechanical systems (MEMS) have spurred efforts worldwide to develop sensing platforms based on smart microcantilevers. A microcantilever beam is one of the simplest MEMS structures which forms the basis for portable, fast and highly sensitive schemes that are capable of measuring small deflections in static or dynamic response due to changes in external parameters such as mass, pressure, charge, etc.
In this dissertation, I mainly focus on MEMS sensors with transducers in the form of microcantilevers. Variations in the microcantilever's response such as resonant frequency, amplitude, phase and quality factor when exposed to …

The Spaceflight Environment And The Skeletal System, Eric Bandstra

All Dissertations

The spaceflight environment presents many challenges to the human body. Bone loss in astronauts is a well known consequence of reduced loading in the weightless environment of low-earth orbit. Recent studies have also indicated that spaceflight relevant types of radiation (at relatively high doses) have deleterious effects on trabecular bone. Both of these represent potential skeletal challenges during long-duration spaceflight. The objective of these studies is to examine the response of bone to models of the spaceflight environment.
Astronauts will likely absorb doses of protons and heavy ions during lengthy missions outside the Earth's magnetosphere. Following exposure to a range …

Chitosan Derivatives For Tissue Engineering, Yongzhi Qiu

All Dissertations

Chitosan, a naturally occurring polysaccharide, and its derivatives have been widely explored for biomedical applications due to their biocompatibility and biodegradability. In our studies, we developed a series of chitosan derivatives through chemical modifications. These chitosan derivatives not only possess better processibility in scaffolds fabrication, but also show excellent potentials in tissue engineering applications, including blood vessel and bone tissue engineering.
The excellent antithrombogenic property is crucial for vascular engineering applications, especially in engineering small-diameter blood vessels. In our studies, chitosan was chemically modified by phthalization and the phthalized chitosan exhibited great antithrombogenic property. Through a wet- phase-inversion process, tubular …

Cues For Cellular Assembly Of Vascular Elastin Networks, Chandrasekhar Kothapalli

All Dissertations

Elastin, a structural protein distributed in the extracellular matrix of vascular tissues is critical to the maintenance of vascular mechanics, besides regulation of cell-signaling pathways involved in injury response and morphogenesis. Thus, congenital absence or disease-mediated degradation of vascular elastin and its malformation within native vessels due to innately poor elastin synthesis by adult vascular cells compromise vascular homeostasis. Current elastin regenerative strategies using tissue engineering principles are limited by the progressive destabilization of tropoelastin mRNA expression in adult vascular cells and the unavailability of scaffolds that can provide cellular cues necessary to up-regulate elastin synthesis and regenerate faithful mimics …

Etsu Gearup: The Design And Development Of An Alternative Energy Greenhouse., Garth Ross Ghearing

Electronic Theses and Dissertations

East Tennessee State has partnered with David Crockett High School through the Federal Gaining Early Awareness and Readiness for Undergraduate Programs. This year's project is an alternative energy greenhouse, which incorporates solar panels and a wind turbine. The focus is on familiarizing students with control systems including programmable logic controllers and power management. There is also an emphasis on the importance of green engineering.

The high school's students have been involved in the design and development of every aspect of the system. The development of the system is ongoing and will be further integrated into classes in the fall semester. …

Aging Of Sand – A Continuing Enigma?, James K. Mitchell

International Conference on Case Histories in Geotechnical Engineering

Sand aging, a process during which the engineering properties of clean sands such as stiffness, penetration resistance and liquefaction resistance may exhibit considerable improvement over periods of only weeks to months after deposition and/or densification by different ground improvement processes, has been shown over the past 30 years to be of considerable practical importance. Numerous examples from a range of projects are presented. Chemical, physical-mechanical, and microbiological processes are examined relative to their adequacy for explaining the observed behavior. Although chemical precipitation-cementation reactions had initially been considered a primary cause, the evidence clearly favors a secondary compression-like process during which …

Microbiological Improvement Of The Physical Properties Of Soil, Edward Kavazanjian Jr., Ismail Karatas

International Conference on Case Histories in Geotechnical Engineering

The application of microbiological processes for improvement of the physical properties of soils offers the promise of sustainable, cost effective, non-disruptive ground improvement for a variety of geotechnical problems. Potentially beneficial applications of microbiological processes include increasing the stiffness of soil to reduce settlement and lateral deformations, increasing shear strength to enhance foundation bearing capacity and slope stability and to facilitate excavation and tunneling, reducing the susceptibility of granular soil to earthquake-induced liquefaction, reducing swell (expansion) potential of fine grained soil, and reducing permeability for groundwater control. Microbiological processes that can potentially be employed for these applications include mineral precipitation, …

Destructive Water-Borne Pressure Waves, Gregory L. Hempen

International Conference on Case Histories in Geotechnical Engineering

Many energetic sources (blasting, pile-driving, seismic exploration, …) near or within a water body may produce destructive, water-borne pressure waves. Pressure waves of sufficient amplitude can impact water-side structures and aquatic fauna. Such energetic sources produce pressure waves and cavitation that can cause concrete to spall, deform metal sheets that are near to the source, kill aquatic organisms, and/or damage hearing of marine mammals at large distances. Any program (energetic systems) that causes pressure waves within the water layer may be conducted in a manner that reduces the pressure waves’ severity. The methodology to reduce pressure waves does not need …

Practical Lessons From Failure Of A Reinforced Soil Retaining Wall On A Major Highway, P. Jagannatha Rao

International Conference on Case Histories in Geotechnical Engineering

A “Reinforced Soil Retaining Wall” (RSR) wall of 10.5m height collapsed about 5 years after construction. HDPE geogrids were used as reinforcement. The facia panels suffered outward movements during construction and the deformations continued to increase. A 16m long stretch of the RSR wall failed and the failure wedge cut through four layers of reinforcement. The paper analyses the role of different factors in causing the failure. Tension tests were carried out on the geogrids exhumed from the failed zone. A significant loss in the strength of these grids was found which may be attributed to the high ambient temperatures …

Lessons Learned From Closing Three Major Landfills – The Devil Really Is In The Details, R. Jeffrey Dunn

International Conference on Case Histories in Geotechnical Engineering

During the past 30 years the author has been involved in a number of landfill closure projects. No two were ever the same, and all were interesting. Three closure projects stand out for the level of effort involved, the rigor of regulatory review, and the issues that occurred during construction, a number of which could have been headed off during design. One site was a major hazardous waste disposal facility and Superfund site; the second, the Fresno Sanitary Landfill, was the oldest sanitary landfill for municipal solid waste in the United States, having opened in 1937 and is also a …

Review Of Lunar Regolith Properties For Design Of Low Power Lunar Excavators, Leslie S. Gertsch, Jamal Rostami, Robert Gustafson

International Conference on Case Histories in Geotechnical Engineering

Lunar regolith is the product of the intermittent comminution of rocks over extremely long durations, and as such is very different from familiar terrestrial soils. A limited amount of information on lunar regolith was collected by the Apollo space program for a few locations. Additional data is required to design effective excavators to prepare outpost sites and to mine the feedstock for production of the material required for a self-sustaining crewed base on the moon. On-site manufacturing would reduce significantly the mass of material that must be launched from Earth. This paper discusses what is known and what is yet …

Deterioration Of Bored Cast In Situ Piles Due To Aggressive Water, V. T. Ganpule, S. Y. Mhaiskar

International Conference on Case Histories in Geotechnical Engineering

Most of the data available from the cement industry and the literature exhibits performance of concrete cubes cured in normal water. Even the literature related to the durability of concrete deals mostly with concrete cured in normal water (closer to potable water in characteristics). However, the bored-cast-in-situ piles are cured in the ground water. The development of strength of concrete of bored cast-in-situ piles depends upon the quality of ground water. The effect of sulphates and chloride is well established and most of the codes stipulate permissible limits of pH, sulphates and chlorides contents in the ground water. In the …

Using New Signal Processing Techniques In Analyzing Masjed Soleyman Embankment Dam's Explosion Records, M. Davoodi, M. K. Jafari, M. Amel Sakhi

International Conference on Case Histories in Geotechnical Engineering

Blasting test studies have one drawback with regard to earthquake studies; they are concerned with vibrations of much smaller amplitude than those normally encountered in earthquakes. Consequently, blasting studies can be used to calibrate dam behavior in a linear elastic range. Accuracy of numerical models should be improved by full scale tests and in situ earthquake records. In this research, first of all a short review of different classical and modern signal processing methods is presented. As it is known, classical signal processing methods, such as FFT and PSD, have many limitations in non- stationary random vibration analysis. Blasting records …

Mechanically Reinforced Earth For Steep Surcharge Slopes In Proximity Of Adjacent Structures To Improve Compressible Soils, Hiren J. Shah, Hugh S. Lacy, Matthew B. Van Rensler

International Conference on Case Histories in Geotechnical Engineering

For a large scale expansion of an existing wastewater treatment plant in Virginia, constructing shallow foundations after surcharging to pre-consolidate the compressible soils at the site was found to be the most attractive foundation option. A detailed geotechnical investigation was performed to characterize the site stratigraphy and soil properties. Many of the tall and steep surcharge embankments were in close proximity of existing operating structures and utilities. Such tall and steep surcharge slopes were designed and constructed of mechanically stabilized earth (MSE). Due to the complex slope geometries, subsurface conditions and nearby critical utilities and existing structures, each MSE slope …

The Indispensable Role Of Case Histories In Landfill Engineering, Edward Kavazanjian Jr.

International Conference on Case Histories in Geotechnical Engineering

Documented case histories are perhaps even more essential to the practice of landfill engineering than to other aspects of geotechnical practice. Case histories are particularly important to landfill engineering because of difficulties in sampling and testing representative materials and the non-homogeneous nature of many landfills. Case histories play an essential role in the evaluation of static and dynamic properties of waste, in identifying potential performance problems and failure mechanisms, and in demonstrating that laboratory interface shear testing can be relied upon to predict field behavior of liner and cover systems. Case histories have proven to be essential in establishing appropriate …

Crumb Rubber As A Sorption Medium For Ethylbenzene In Aqueous Solution, Carmen Grayson

All Theses

Scrap tires have always been an environmental concern. In 2005, more than 299 million scrap tires were generated in the U.S., 259 million of which were utilized in the end-use scrap tire markets such as: tire-derived fuel generation, civil engineering applications, and ground rubber applications. The different applications and usages in the scrap tire market have helped utilize up to 87% of annually generated scrap tires in the U.S. Sixteen percent of the scrap tires were utilized in civil engineering applications in 2005 because of their beneficial properties for vibration and sound control, lightweight fill, drainage and collection for underground …

Image-Guided Raman Spectroscopic Recovery Of Canine Cortical Bone Contrast In Situ, Subhadra Srinivasan, Matthew Schulmerich, Jacqueline H. Cole, Kathryn Dooley, Jaclynn M. Kreider, Brian W. Pogue

Dartmouth Scholarship

Raman scattering provides valuable biochemical and molecular markers for studying bone tissue composition with use in predicting fracture risk in osteoporosis. Raman tomography can image through a few centimeters of tissue but is limited by low spatial resolution. X-ray computed tomography (CT) imaging can provide high-resolution image-guidance of the Raman spectroscopic characterization, which enhances the quantitative recovery of the Raman signals, and this technique provides additional information to standard imaging methods. This hypothesis was tested in data measured from Teflon tissue phantoms and from a canine limb. Image-guided Raman spectroscopy (IG-RS) of the canine limb using CT images of the …

Self-Encoded Spread Spectrum Synchronization And Cooperative Diversity, Kun Hua

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

This dissertation research concerns a novel self-encoded spread spectrum. It provides a feasible practical implementation for random spreading codes. The traditional transmit and receive PN code generators are not needed. Instead, the spreading codes are extracted from the user's information bits itself. Comparing to conventional CDMA, SESS completely abandons the use of pseudo-random spreading codes. The code variability doesn't depend on the spreading length like pseudo-random codes.

But because the self-encoded spreading sequence is random and time varying, data recovery requires that the despreading sequence be identical with the spreading sequence at the start of the transmission. Synchronization is one …

In-Plane Photonic Transduction Of Silicon-On-Insulator Microcantilevers, Ryan Anderson, Seunghyun Kim, Gregory P. Nordin, Jong Wook Noh, Jaime Cardenas

Faculty Publications

We demonstrate an in-plane photonic transduction method for microcantilevers, which have been widely investigated for sensor applications. In our approach the microcantilever is etched to form a single mode rib waveguide. Light propagates down the microcantilever and crosses a small gap at the free end of the microcantilever, some of which is captured by an asymmetrical multimode waveguide that terminates in a Y-branch. The Y-branch outputs are used to form a differential signal that is monotonically dependent on microcantilever deflection. The measured differential signal matches simulation when microcantilever rotation is properly accounted for. The measured differential signal sensitivity is 1.4 …