Digital Commons Network^™

Impaired Resistance Artery Reactivity Following Arteriogenesis, Michael (Mike) Machado

Biomedical Engineering

No abstract provided.

Testing, Modelling And Validation Of Numerical Model Capable Of Predicting Stress Fields Throughout Polyurethane Foam, Conor Briody, Barry Duignan, Stephen Jerrams

Conference Papers

Wheelchair seating systems are specialised for a number of reasons as users can have impaired mobility, which increases the possibility of pressure build up. These areas of high pressure frequently occur in the trunk region under the bony prominences known as the Ischial Tuberosities (IT), pressure ulcers may occur consequently. Polyurethane foam has been in use for some time in wheelchair seating systems as it exhibits good pressure relieving capabilities in most cases. However, little quantitative research has gone into foamed polymers, in comparison with conventional elastomeric materials. This lack of knowledge can ultimately lead to more time being spent …

Bs News September/October

Building Services Engineering

No abstract provided.

Robust Cns Regeneration After Complete Spinal Cord Transection Using Aligned Poly-L-Lactic Acid Microfibers, Andres Hurtado, Jared M. Cregg, Han B. Wang, Dane F. Wendell, Martin Oudega, Ryan J. Gilbert, John W. Mcdonald

Chemical and Biochemical Engineering Faculty Research & Creative Works

Following spinal cord injury, axons fail to regenerate without exogenous intervention. In this study we report that aligned microfiber-based grafts foster robust regeneration of vascularized CNS tissue. Film, random, and aligned microfiber-based conduits were grafted into a 3 mm thoracic rat spinal cord gap created by complete transection. Over the course of 4 weeks, microtopography presented by aligned or random poly- l-lactic acid microfibers facilitated infiltration of host tissue, and the initial 3 mm gap was closed by endogenous cell populations. This bulk tissue response was composed of regenerating axons accompanied by morphologically aligned astrocytes. Aligned fibers promoted long distance …

Computational Simulations Demonstrate Altered Wall Shear Stress In Aortic Coarctation Patients Previously Treated By Resection With End-To-End Anastomosis, John F. Ladisa, Ronak Jashwant Dholakia, Alberto Figueroa, Irene E. Vignon-Clementel, Frandics P. Chan, Margaret M. Samyn, Joseph Richard Cava, Charles A. Taylor, Jeffrey A. Feinstein

Biomedical Engineering Faculty Research and Publications

Background.  Atherosclerotic plaque in the descending thoracic aorta (dAo) is related to altered wall shear stress (WSS) for normal patients. Resection with end-to-end anastomosis (RWEA) is the gold standard for coarctation of the aorta (CoA) repair, but may lead to altered WSS indices that contribute to morbidity.

Methods.  Computational fluid dynamics (CFD) models were created from imaging and blood pressure data for control subjects and age- and gender-matched CoA patients treated by RWEA (four males, two females, 15 ± 8 years). CFD analysis incorporated downstream vascular resistance and compliance to generate blood flow velocity, time-averaged WSS (TAWSS), and oscillatory shear …

Spatial And Temporal Variation Of Rod Photoreceptor Reflectance In The Human Retina, Robert F. Cooper, Adam M. Dubis, Ashavini M. Pavaskar, Jungtae Rha, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Using adaptive optics imaging tools to image the living retina, numerous investigators have reported temporal fluctuation in the reflectivity of individual cone photoreceptors. In addition, there is cone-to-cone (spatial) variation in reflectivity. As it has only recently become possible to image the complete rod photoreceptor mosaic in the living human retina, we sought to characterize the reflectivity of individual rods and compare their behavior to that of foveal/parafoveal cones. Across two subjects, we were able to successfully track the reflectance behavior of 1,690 rods and 1,980 cones over 12 hours. Rod and cone photoreceptors showed similar regional and temporal variability …

The Impact Of Dynamic And Passive Standing On Bone Mineral Density And Appositional Growth In Immobilized Children, Megan Diane Damcott

Dissertations

The first discovery of the potential role that mechanical loading has on determining the strength of bone occurred in 1892. However, for almost a century after this discovery, the specific mechanisms influenced by mechanical loading remained locked in a mysterious 'black box'. Then in the 1960s, the 'black box' was opened and continued work has now unlocked the basic mechanisms involved in mechanical loading and whole-bone strength. This increased knowledge has spurred clinicians and researchers to investigate the impact of weight-bearing interventions on individuals with an increased risk of osteoporosis. The most common weight-bearing clinical intervention used in non-ambulant populations …

Influence Of Rear Wheel Tire Type On Wheelchair Propulsion Biomechanics, Mathew Yarossi

Theses

The objective of this study was to determine how rear wheel tire type affects wheelchair propulsion mechanics. Four persons with paraplegia and four persons with tetraplegia propelled their own wheelchairs on a roller system at self-selected speed using five different pairs of tires. Upper limb and trunk kinematics, perceived exertion, stroke pattern and the temporal characteristics of propulsion were measured. When using pneumatic (air filled) tires, with lower rolling resistance, participants had lower push frequency (p < .05), higher self selected speed (p < .05), less perceived exertion, less shoulder internal rotation, and a longer push stroke than when using solid, high rolling resistance tires. As rolling resistance increased, participants experienced negative changes in propulsion characteristic that contradicted current clinical practice guidelines for upper limb preservation following spinal cord injury. In addition, kinematics with solid, high rolling resistance tires were similar to those described during uphill or over carpet propulsion. In order to avoid unnecessary strain on the upper limbs and unwanted changes in propulsion biomechanics, wheelchair users, clinicians, and researchers should consider the use of lower rolling resistance, pneumatic rear tires.

Use Of Fluorescent Micropsheres To Measure Coronary Flow Reserve In Rat Animal Model, Riddhi Harsh Shah

Theses

Heart attacks result from reduced or blocked blood flow through major coronary arteries, resulting in permanent damage to heart muscle. Coronary blood flow (CBF) is thus important to measure in experimental animal models of heart disease. A standard method to measure CBF uses tracer microspheres (Ø = 15 µm) injected into the left ventricle that flow through coronary arteries but cannot pass through capillaries and so become trapped in heart muscle. Previously, radioactive or colored microspheres have quantified the number of tracers trapped in the muscle. Fluorescent microspheres offer a more recent and more sensitive measurement mode. However, fluorescent microspheres …

Novel Routes For Synthesis Of Pd Nanoparticles And Faceted Zno Supports For Heterogeneous Catalysts, Patrick David Burton

Chemical and Biological Engineering ETDs

Alcohol steam reforming is a promising source of hydrogen as fuel, and could be improved by the use of an optimal catalyst. The methanol steam reforming reaction, CH3OH+H2O --> 3H2+CO2 frequently conducted by means of a Cu/ZnO catalyst. Unfortunately, this catalyst deactivates quickly and is pyrophoric. Pd catalysts are much more stable, but reactions using these catalyst follow the decomposition pathway, CH3OH --> 2H2+CO. PdZn alloys can achieve the desired selectivity, and have been noted to form under reaction conditions from Pd/ZnO heterogeneous catalysts. In the present work, careful synthesis techniques of specific support and nanoparticle surfaces have been developed …

A Framework For Usage Management, Pramod Jamkhedkar

Electrical and Computer Engineering ETDs

This thesis proposes a formal framework for usage management in distributed systems. The principles of system design are applied in order to standardize certain features of the framework, such as the operational semantics, and leave free of standards areas that necessitate choice and innovation. The framework enables use of multiple policy languages, and dynamic interpretation of usage policies in different computing environments. In addition, the framework provides formal semantics to reason about interoperability of policies with respect to computing environments. The use of this framework in different usage management scenarios is demonstrated including multi-level security, cloud computing and digital rights …

Rehabilitation And Exercise Machine, Judith M. Burnfield, Yu Shu, Adam P. Taylor, Thad W. Buster, Carl Nelson

Department of Mechanical and Materials Engineering: Faculty Publications

An improved rehabilitation and exercise machine is provided which allows a person with physical limitations, disabilities or chronic conditions to use the machine in order to rehabilitate their muscles, improve joint flexibility, and enhance cardiovascular fitness.

Applying Numerical Sediment Transport Models To Examine River Restoration Sustainablilty At The Rio Grande Nature Center, New Mexico, Kyle Shour

Civil Engineering ETDs

Much of the Middle Rio Grande has severely degraded since 1930 when flood control institution began (Scurlock 1998). Since that time, additional anthropogenic stressors have continued to cause the river to incise and narrow and have harmed the ecological health of the system. As a result, many different entities have developed restoration projects along the Middle Rio Grande. These projects are often localized, small scale features that promote native vegetation establishment and improve habitat for endangered species without removing flood protection measures. One such feature is the Rio Grande Nature Center (RGNC) Habitat Restoration project. The project consists of removing …

Application Of Hec-Hms 3.4 In Estimating Streamflow Of The Rio Grande Under Impacts Of Climate Change, Chi Bui

Civil Engineering ETDs

The Rio Grande originates from the San Juan Mountains of southern Colorado, and flows year-round south through the entire length of New Mexico. It has an approximate drainage area of 1.9 million acres in New Mexico (USGS 1996), and provides habitat for diverse wildlife along the river, including the silvery minnow, an endangered indicator species. The hydrology of the river is characterized by low flow during the winter months, a snow-induced peak in spring/early summer, and smaller peaks in July and August due to the effect of the monsoon season. In the five recent decades, the Rio Grande has experienced …

Using Vibration-Based Monitoring To Detect Mass Changes In Satellites, Breck Vernon

Civil Engineering ETDs

Vibration-based structural health monitoring could be a useful form of determining the health and safety of space structures. A particular concern is the possibility of a foreign object that attaches itself to a satellite in orbit for adverse reasons. A frequency response analysis was used to determine the changes in mass and moment of inertia of the space structure based on a change in the natural frequencies of the structure or components of the structure. Feasibility studies were first conducted on a 7 in x 19 in aluminum plate with various boundary conditions, which was impacted with a mallet and …

Command Vs. Self-Regulation In Construction Safety : A Case Study Of Chase, Amelia Scharrer

Civil Engineering ETDs

According to the Bureau of Labor Statistics in 2009 there were 816 fatal injuries in the United States in the construction industry. Reducing injuries and fatalities on construction sites is good for workers, contractors, and owners. The Occupational Health and Safety Administration (OSHA) was created to ensure safe and healthful working conditions for all working men and women. In order to achieve this goal OSHA has been setting and enforcing standards with a command-and-control' system, outreach, education and assistance. However, incidents still occur on construction sites. The gaps within the 'command-and-control' system have lead researchers and industry to look at …

Acoustic Bandgap Sensors For Hot-Spot Damage Monitoring, Ryan Schnalzer

Civil Engineering ETDs

This research presents a novel, mechanically tunable sensor that utilizes the acoustic response of a polymer based acoustic bandgap (ABG) material to identify and quantify damage in material substrates. Acoustic bandgap (ABG) sensors are the mechanical analogues of semi-conductors by which a periodic array of differing acoustic impedances causes an acoustic bandgap. This is comparable to the periodic array of electronic potentials that cause an electronic bandgap in semi-conductors. An ABG sensor is composed of a host matrix material with a periodic array of inclusions/scatterers made of a material with dissimilar acoustic impedance. ABG sensors offer advantages to structural health …

A Real-Time, Reconfigurable System For Energy, Error-Resilient, And Scalable Lossless Ecg Coding, Paul Essenmacher

Electrical and Computer Engineering ETDs

Electrocardiogram (ECG) monitoring systems have evolved to the point where they are now portable and can monitor the patient 24/7 and transmit alerts and ECG data to parents and doctors as soon as a heart irregularity is detected. With the advances in these systems, there is a need for the incorporation of ECG coding systems to reduce the bandwidth used when data is transmitted and to incorporate methods to provide data recovery in the event of a transmission error. However, while ECG encoding systems for hospital or home care settings has been thoroughly researched, the application of ECG encoding systems …

Left Ventricular Assist Devices: Engineering Design Considerations, Marwan A. Simaan, Eduardo Divo, George Faragallah, Yu Wang

Publications

Patients with end-stage congestive heart failure awaiting heart transplantation often wait long periods of time (300 days or more on the average) before a suitable donor heart becomes available. The medical community has placed increased emphasis on the use of Left Ventricular Assist Devices or LVADs that can substitute for, or enhance, the function of the natural heart while the patient is waiting for the heart transplant (Poirier, 1997; Frazier & Myers, 1999). Essentially, a rotary LVAD is a pump that operates continuously directing blood from the left ventricle into the aorta by avoiding the aortic valve. Generally speaking, the …

Runx2 Protein Expression Utilizes The Runx2 P1 Promoter To Establish Osteoprogenitor Cell Number For Normal Bone Formation, Julie C. Liu, Christopher J. Lengner, Tripti Gaur, Yang Lou, Sadiq Hussain, Marci D. Jones, Brent Borodic, Jennifer L. Colby, Heather A. Steinman, Andre J. Van Wijnen, Janet L. Stein, Stephen N. Jones, Gary S. Stein, Jane B. Lian

School of Chemical Engineering Faculty Publications

The Runt-related transcription factor, Runx2, is essential for osteogenesis and is controlled by both distal (P1) and proximal (P2) promoters. To understand Runx2 function requires determination of the spatiotemporal activity of P1 and P2 to Runx2 protein production. We generated a mouse model in which the P1-derived transcript was replaced with a lacZ reporter allele, resulting in loss of P1-derived protein while simultaneously allowing discrimination between the activities of the two promoters. Loss of P1-driven expression causes developmental defects with cleidocranial dysplasia-like syndromes that persist in the postnatal skeleton. P1 activity is robust in preosteogenic mesenchyme and at the onset …

Sustainable Development, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of Sustainable Development issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Water - Activities, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

The document contains activities for students in higher education. These activities are focused on water issues related to sustainability. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. Each activity includes a profile that indicates whether the activity involves direct or indirect information sources, whether the experience is doing or observing and whether it involves individual or group reflection. The profile also includes notes for faculty, an estimate of the time investment, a graphic of the developmental aims with respect to the six areas of …

Population, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of population issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Systems Thinking - Assessment, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

The document contains an assessment activity for an individual or team project in higher education. These assessments are focused on systems thinking issues related to sustainability. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. Each assessment consists of a scenario in which the student is an actor who must address some design dilemma. The assessment also includes an estimate of the time investment, a detailed list of learning objectives with respect to the six areas of development within the Fink Taxonomy, and a suggested …

Systems Thinking - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the systems thinking is based on.

Population - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the population is based on.

Materials, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of materials issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Water, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of water issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Energy, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of energy issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Water - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the water is based on.