Digital Commons Network^™

Hydrodynamic Focused Passive Separation Under Continuous Flow In A Microfluidic Chip, Jad Kanbar

Master's Theses

A continuous flow, passive separation device was designed using an equivalent circuit to create variable flow rates for hydrodynamic focusing to drain channels and collection outlets. By varying the diameter of the sample inlet connection into the reservoir, the particle position was influenced significantly, which enabled desired separations. Additionally it was noted that the relative, horizontal position of the inlet also had a significant influence on particle position within the device. A dimensionless number, the Characteristic Sample Inlet, was developed to relate geometric properties of the inlet reservoir to downstream particle distribution. It was found that a 2:1 ratio between …

Floating Wetland Systems For Nutrient Removal In Stormwater Ponds, Ni-Bin Chang, Martin Wanielista, Manoj Chopra

BMP Trains Research and Publications

Wet detention ponds are frequently used in stormwater management systems as part of a treatment train for attenuation of flow and removal of pollutants. Wet detention ponds designed and operated according to commonly used standards and specifications remove nutrients but the removal of nitrogen has remained low, about 30-40% concentration reduction on a yearly basis. A Floating Treatment Wetland (FTW) composed of selected plants suspended in a wet detention pond was proposed in this research to improve the removal of nutrients before discharge from a pond.

Investigation Of A New Material For Heart Valve Tissue Engineering, Claire Brougham, Gerard Cooney, Thomas Flanagan, Stefan Jockenhoevel, Fergal O'Brien

Conference Papers

No abstract provided.

Maximal Force Characteristics Of The Ca2+-Powered Actuator Of Vorticella Convallaria, Sangjin Ryu, Matthew J. Lang, Paul Matsudaira

Department of Mechanical and Materials Engineering: Faculty Publications

The millisecond stalk contraction of the sessile ciliate Vorticella convallaria is powered by energy from Ca²⁺ binding to generate contractile forces of ~10 nN. Its contractile organelle, the spasmoneme, generates higher contractile force under increased stall resistances. By applying viscous drag force to contracting V. convallaria in a microfluidic channel, we observed that the mechanical force and work of the spasmoneme depended on the stalk length, i.e., the maximum tension (150–350 nN) and work linearly depended on the stalk length (~2.5 nN and ~30 fJ per 1 mm of the stalk). This stalk-length dependency suggests that motor units of …

Low Power Data Acquisition For Microimplant Biometric Monitoring Of Tremors, Tania Khanna '01

Doctoral Dissertations

In recent years, trends in the medical industry have created a growing demand for implantable medical devices. In particular, the need to provide doctors a means to continuously monitor biometrics over long time scales with increased precision is paramount to efficient healthcare. To make medical implants more attractive, there is a need to reduce their size and power consumption. Small medical implants would allow for less invasive procedures, greater comfort for patients, and increased patient compliance. Reductions in power consumption translate to longer battery life. The two primary limitations to the size of small medical implants are the batteries that …

Creep Evaluation Of (Orthotic) Cast Materials During Simulated Clubfoot Correction, T. L. Cohen, H. Altiok, Sergey Tarima, P. A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot that relies on weekly manipulations and cast applications. However, the material behavior of the cast in the Ponseti technique has not been investigated. The current study sought to characterize the ability of two standard casting materials to maintain the Ponseti corrected foot position by evaluating creep response. A dynamic cast testing device (DCTD) was built to simulate a typical pediatric clubfoot. Semi-rigid fiberglass and rigid fiberglass casting materials were applied to the device, and the rotational creep was measured at various constant torques. The movement …

Responding To Dangerous Accidents Among The Elderly: A Fall Detection Device With Zigbee-Based Positioning, Michael R. Putnam

Master's Theses

The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting …

Chronically Inadequate Sleep Results In Abnormal Bone Formation And Abnormal Bone Marrow In Rats, Carol A. Everson, Anne E. Folley, Jeffrey M. Toth

Biomedical Engineering Faculty Research and Publications

Insufficient sleep over long durations of the lifespan is believed to adversely affect proper development and healthful aging, although how this might become manifested is unknown. In the present study, rats were repeatedly sleep-restricted during 72 days to permit maladaptations to evolve, thereby permitting study. Densitometric and histomorphometric analyses were performed on harvested bone. In sleep-restricted rats, bone lined by osteoid was reduced 45-fold and osteoid thickness was decreased, compared with controls. This corresponded to a decrease in osteoblast number and activity. The percentage of bone lined by osteoclasts did not differ from that of controls. Plasma concentrations of an …

Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Multivariate prediction algorithms such as FRAX® and QFracture Scores provide an opportunity for new prognostic biomarkers to be developed and incorporated, potentially leading to better fracture prediction. As more research is conducted into these novel biomarkers, a number of factors need to be considered for their successful development for inclusion in these algorithms. In this review, we describe two well-known multivariate prediction algorithms for osteoporosis fracture risk applicable to the UK population, FRAX and QFracture Scores, and comment on the current prognostic tools available for fracture risk; dual X-ray assessment, quantitative ultrasonography, and genomic/biochemical markers. We also highlight the factors …

Graphene-Coated Substrates For Biochemical And Optoelectronic Applications, Amrita Banerjee

Dissertations

Graphene - monolayer or a few layers of graphite -- has proven to possess remarkable properties: large thermal conductivity, mechanical robustness, two-dimensional ultra large electronic mobility, chemical inertness and biochemical compatibility. Realization of some applications has been impeded by lack of a large area deposition method. By using a novel methodology to deposit graphene on solid and perforated substrates, various optoelectronic and biochemical elements have been demonstrated in this thesis: (1) graphene based transistors were fabricated and their characteristics were assessed. The mobility for such transistors exceeded 5000 cm2/V·s, much larger than their silicon based counterparts. Such attribute opens up …

High Aspect Ratio Electrodes For High Yield Electroporation Of Cells, Anil B. Shrirao

Dissertations

Electroporation is a widely used process in cell biology studies. It uses an electric field to create pores on the cell membrane in order to either insert exogenous molecules inside the cells or disrupt the cell membrane to kill the cells. Current micro-fluidic electroporation devices use the planar electrodes situated at the bottom of a microchannel. These planar electrodes i) require a high voltage and ii) generate a nonuniform electric field which result in low yield of the electroporation. The standard silicon microfabrication technologies are not suitable to fabricate non-planar electrodes required to increase the yield of electroporation.

In this …

Hemorrhage Detection And Analysis In Traumatic Pelvic Injuries, Pavani Davuluri

Theses and Dissertations

Traumatic pelvic injuries associated with high-energy pelvic fractures are life-threatening injuries. Extensive bleeding is relatively common with pelvic fractures. However, bleeding is especially prevalent with high-energy fractures. Hemorrhage remains the major cause of death that occur within the first 24 hours after a traumatic pelvic injury. Emergent-life saving treatment is required for high-energy pelvic fractures associated with hemorrhage. A thorough understanding of potential sources of bleeding within a short period is essential for diagnosis and treatment planning. Computed Tomography (CT) images have been widely in use in identifying the potential sources of bleeding. A pelvic CT scan contains a large …

Challenges Of Permitting Ballast Water Discharges From Commercial Vessels In U.S. Waters, Paul Rodriguez

Theses

On February 5, 2009, the US Environmental Protection Agency (US EPA) issued the Vessel General Permit (VGP), under the Clean Water Act (CWA), for discharges incidental to the normal operation of vessels, including ballast water discharges. This set forth permit requirements for most commercial vessel discharges within 3 nautical miles of U.S. shore. Since it will expire in December 2013, the US EPA recently issued a draft 2013 VGP. One of the significant changes is the proposal of numerical ballast water discharge standards requiring most commercial vessels to install ballast water treatment systems onboard.

The objective of this thesis is …

Extendsim-Based Research On Transport Process Optimization Of Emergency Cold-Chain Logistics, Ran Zhang

World Maritime University Dissertations

No abstract provided.

Freight Forecasting Of Dry Bulk Market Based On The Bp Neural Network, Qianran Huang

World Maritime University Dissertations

No abstract provided.

Multichannel Diffuse Optical Raman Tomography For Bone Characterization In Vivo: A Phantom Study, Jennifer-Lynn H. Demers, Scott C. Davis, Brian W. Pogue, Michael D. Morris

Dartmouth Scholarship

Raman spectroscopy is used to gather information on the mineral and organic components of bone tissue to analyze their composition. By measuring the Raman signal of bone through spatially offset Raman spectroscopy the health of the bone can be determined. We’ve customized a system with 8 collection channels that consist of individual fibers, which are coupled to separate spectrometers and cooled CCDs. This parallel detection system was used to scan gelatin phantoms with Teflon inclusions of two sizes. Raman signals were decoupled from the autofluorescence background using channel specific polynomial fitting. Images with high contrast to background ratios of Raman …

Population And Coherence Dynamics In Light Harvesting Complex Ii (Lh2), Shu-Hao Yeh, Jing Zhu, Sabre Kais

Birck and NCN Publications

The electronic excitation population and coherence dynamics in the chromophores of the photosynthetic light harvesting complex 2 (LH2) B850 ring from purple bacteria (Rhodopseudomonas acidophila) have been studied theoretically at both physiological and cryogenic temperatures. Similar to the well-studied Fenna-Matthews-Olson (FMO) protein, oscillations of the excitation population and coherence in the site basis are observed in LH2 by using a scaled hierarchical equation of motion approach. However, this oscillation time (300 fs) is much shorter compared to the FMO protein (650 fs) at cryogenic temperature. Both environment and high temperature are found to enhance the propagation speed of the exciton …

In Vitro Cytotoxicity And Skin Irritation Testing Of Antimicrobial Conjugated Electrolytes : Interactions With Mammalian Cells, Kristin N. Wilde

Chemical and Biological Engineering ETDs

An estimated 19,000 deaths and $3-4 billion in health care costs per year in the U.S. are attributed to methicillin-resistant Staphylococcus aureus (MRSA) infections. Certain cationic phenylene ethynylene (CPE)-based polymers (PPEs) and oligomers (OPEs) have been demonstrated to exhibit dark and light-activated antimicrobial activity. Envisioned applications of these CPEs include the fabrication of antimicrobial surfaces to reduce or prevent the spread of potentially untreatable strains of bacteria. Until recently, it was unknown if the polymers or oligomers would exhibit similar biocidal activity toward mammalian cells. This work examines the toxicity of CPEs to mammalian cells at three levels: cytoxicity testing …

Methods Of Cellular Integration And Techniques For Improving Encapsulated Cell Viability For The Purpose Of Developing Living Materials And Cell Based Bio-Sensing Materials, Travis J. Savage

Chemical and Biological Engineering ETDs

Living materials offer the potential for detection-reporter systems based on living cells that are genetically tailored to sense target analytes with high levels of specificity and accuracy. A biotic or living material would allow the development of simple, hand held devices that could be utilized for many applications including industrial process monitoring, environmental remediation, military and defense applications and drug delivery. Many living materials have been developed and characterized but they still lack heightened and prolonged encapsulated cell viability necessary to make the material a candidate for widespread use. One particular material offers several advantages to increase yeast cell viability …

The Effects Of Acetate Concentrations On Competition Between Microbial Populations In Enhanced Biological Phosphorus Removal From Wastewater, Yunjie Tu

Civil Engineering ETDs

Enhanced biological phosphorus removal (EBPR) is a popular modification of the activated sludge process, and has been studied and applied for decades. It was hypothesized that the bacteria responsible for EBPR, polyphosphate accumulating organisms (PAOs), have an advantage over their competitors, the glycogen accumulating organisms (GAOs). Because research EBPR systems have been primarily sequencing batch reactors (SBRs), which include rapid feed addition and relatively high substrate concentrations, while full scale systems often include complete mix reactors, which yield generally lower substrate concentrations due to instantaneous dilution of influent, evaluating this hypothesis has both fundamental and applied implications. The primary objectives …

Direct Writing Of Au Nanoneedles Array On Glass By Confined Laser Spinning, Yingling Yang, Dong Lin, Gary J. Cheng

Birck and NCN Publications

Generation of gold nanoneedles on glass by confined laser spinning was explored by using a nanosecond pulsed laser. When the coated Au thin film was irradiated under the confinement of glass, gold nanoneedles were formed by spreading the molten liquid of gold under high pressure. The mechanism of the confined laser spinning process is studied. The maximum velocity and instability of molten liquid during confined laser spinning were estimated. The diameter of nanoneedles can be controlled by changing the thickness of coated gold thin film. Large scale of gold nanoneedles can be formed by this direct writing method and collected …

Multipartite Quantum Entanglement Evolution In Photosynthetic Complexes, Jing Zhu, Sabre Kais, Alan Aspuru-Guzik, Sam Rodriques, Ben Brock, Peter J. Love

Birck and NCN Publications

We investigate the evolution of entanglement in the Fenna-Matthew-Olson (FMO) complex based on simulations using the scaled hierarchical equations of motion approach. We examine the role of entanglement in the FMO complex by direct computation of the convex roof. We use monogamy to give a lower bound for entanglement and obtain an upper bound from the evaluation of the convex roof. Examination of bipartite measures for all possible bipartitions provides a complete picture of the multipartite entanglement. Our results support the hypothesis that entanglement is maximum primary along the two distinct electronic energy transfer pathways. In addition, we note that …

Modeling, Control And Characterization Of Aircraft Electric Power Systems, Hadi Ebrahimi

Electrical Engineering Theses

A study model of advanced aircraft electric power system (AAEPS) corresponding to B767 Aircraft is developed in the PSIM9 software environment. The performance characteristics of the system under consideration for large sharing of non-linear loads are studied. A comprehensive mathematical model describing system dynamics is derived where the GSSA technique is applied for reduced-order system approximation. The transient and steady-state performance of the hybrid PEM-FC/battery APU integrated to the aircraft electric network is analyzed while different loading scenarios are taken into account. In addition, dynamic bifurcation analysis is employed to characterize the systems stability performance under multi-parameters condition. Also, the …

Adding Autonomic Healing Capabilities To Polyethylene Oxide, Dorina M. Chipara, Maritza Flores, Alma Perez, Nancy Puente, Karen Lozano, Mircea Chipara

Mechanical Engineering Faculty Publications

The addition of autonomic healing (frequently defined as self-healing) capabilities to a water-soluble polymer (polyethylene oxide, PEO) is for the first time reported. The self-healing system consists of urea-formaldehyde microcapsules filled with dicyclopentadiene and first-generation Grubbs catalyst, dispersed within polyethylene oxide. Raman spectroscopy, optical microscopy, electron microscopy, and thermogravimetric analysis were used to characterize this autonomic healing system. Self-healing capabilities were confirmed by mechanical testing (load–displacement, engineering stress–engineering strain, and true stress–true strain dependences) recorded at very slow elongation rates (0.01 mm/s). The testing fate was chosen to allow for the complete consumption of the monomer before fracture (the polymerization …

Mineralization Potential Of Electrospun Pdo-Hydroxyapatite-Fibrinogen Blended Scaffolds, Isaac A. Rodriguez, Parthasarathy A. Madurantakam, Jennifer M. Mccool, Scott A. Sell, Hu Yang, Peter C. Moon, Gary L. Bowlin

Chemical and Biochemical Engineering Faculty Research & Creative Works

The current bone autograft procedure for cleft palate repair presents several disadvantages such as limited availability, additional invasive surgery, and donor site morbidity. The present preliminary study evaluates the mineralization potential of electrospun polydioxanone:nano-hydroxyapatite: fibrinogen (PDO: nHA: Fg) blended scaffolds in different simulated body fluids (SBF). Scaffolds were fabricated by blending PDO: nHA: Fg in the following percent by weight ratios: 100: 0: 0, 50: 25: 25, 50: 50: 0, 50: 0: 50, 0: 0: 100, and 0: 50: 50. Samples were immersed in (conventional (c), revised (r), ionic (i), and modified (m)) SBF for 5 and 14 days to …

Where Did All Those Launches Come From? Or What Can We Do Now That We Have Launches?, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Where did all those Launches come from? Or What can we do now that we have launches?" from August 11, 2012.

Schmidtea Mediterranea Planaris As A Novel Animal Model For Investigating The Dynamics Of Nervous System Development In Fetal Alcohol Spectrum Disorder, Jesse Lowe

Theses and Dissertations

Fetal Alcohol Spectrum Disorder (FASD) is a prevalent developmental disease that is caused by excess in utero exposure to ethanol. The importance of timing and dosage of ethanol has been elucidated by previous investigations conducted with humans, rodents, and other model organisms, but challenges associated with determining functional deficiencies have necessitated the introduction of a novel animal model for investigating the dynamics of FASD. In this thesis, we propose that the freshwater flatworm planarian species, Schmidtea mediterranea, has the capability to fulfill this need. Planaria have the ability to completely regenerate fragments into intact, functional animals, and in these studies, …

Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive Manufacturing (AM) has shown considerable promise for the future but also proposes some challenges. Many AM barriers tend to be non-technical and instead are human-centric issues such as lack of education of practitioners in AM capabilities, cultural differences, vested interests, and potentially lack of imagination. It is highly desirable for all research and educational institutions to help address these issues. This paper summarizes the additive manufacturing research and education program at the Missouri University of Science and Technology (Missouri S&T) and its interactions with various constituents, including K-12 students, undergraduate and graduate students, distance students, and industry.

A Digital X-Ray Tomosynthesis Coupled Near Infrared Spectral Tomography System For Dual-Modality Breast Imaging, Venkataramanan Krishnaswamy, Kelly E. Michaelsen, Brian W. Pogue, Steven P. Poplack, Ian Shaw, Ken Defrietas, Ken Brooks, Keith D. Paulsen

Dartmouth Scholarship

A Near Infrared Spectral Tomography (NIRST) system has been developed and integrated into a commercial Digital Breast Tomosynthesis (DBT) scanner to allow structural and functional imaging of breast in vivo. The NIRST instrument uses an 8-wavelength continuous wave (CW) laser-based scanning source assembly and a 75-element silicon photodiode solid-state detector panel to produce dense spectral and spatial projection data from which spectrally constrained 3D tomographic images of tissue chromophores are produced. Integration of the optical imaging system into the DBT scanner allows direct co-registration of the optical and DBT images, while also facilitating the synergistic use of x-ray contrast as …

Integrated Fiber Electrospinning: Creating Spatially Complex Electrospun Scaffolds With Minimal Delamination, Casey Grey

Theses and Dissertations

Tissue engineering scaffolds come in many shapes and sizes, however, due to difficulty manufacturing the microstructure architecture required in tissue engineering, most scaffolds are architecturally non-dynamic in nature. Because the microstructural architecture of all biological tissues is inherently complicated, non-dynamic tissue engineering scaffolds tend to be a poor platform for tissue regeneration. The current method for manufacturing dynamic tissue engineering scaffolds involves electrospinning successive layers of different fibers, an approach that exhibits no fiber transition between layers and subsequent delamination problems. In this study we aim to address the design challenges of tissue engineering scaffolds through our novel integrated fiber …