Augmented Human Inspired Phase Variable Using a Canonical Dynamical System

Accurately parameterizing human gait is highly important in the continued development of assistive robotics, including but not limited to lower limb prostheses and exoskeletons. Previous studies introduce the idea of time-invariant real-time gait parameterization via human-inspired phase variables. The phase represents the location or percent of the gait cycle the user has progressed through. This thesis proposes an alternative approach for determining the gait phase leveraging previous methods and a canonical dynamical system. Human subject experiments demonstrate the ability to accurately produce a phase variable corresponding to the human gait progression for various walking configurations. Configurations include changes in incline and speed. Results show an augmented real-time approach capable of adapting to different walking conditions

ENHANCING THE EFFICIENCY OF ELECTROKINETIC REMEDIATION THROUGH THE USE OF COMPLEXING AGENTS

Electrokinetic remediation was accessed as a viable remediation technology for heavy metal contamination modeled after contamination present in Butte, MT caused by over a century of hard rock mining. The remediation technology was assessed at a laboratory scale using copper sulfate (CuSO4) as a model compound of mine tailing contamination, and an artificial soil to control for variables outside the scope of work. This thesis designed a laboratory scale experiment that produced consistent results and could be easily repeated. The system design also included a method for managing the waste material produced during experiments. Following the experimental design, this thesis evaluated the effect of several complexing agents on the transport rates of copper ions (Cu2+) in an electrokinetic system. Chloride (Cl-), bromide (Br-), ammonia (NH3), and ethylenediaminetetraacetic acid (EDTA) were used to complex copper ions, originally hydrated with water molecules. A total of 17 experiments were conducted during this thesis. Transport rates were calculated using real-time direct current measurements and inductively coupled plasma (ICP) analysis data. Previous studies suggested that the transport of the complexed ions was directly proportional to their complex radii. However, in this thesis, the size to transport rate relationship was not observed, and depletion/enrichment rates varied within experiments. Depletion and enrichment were defined as the percent change of copper mass in the electrode compartment from initial to final conditions. The largest enrichment rates were observed in the CuSO4 experiments at 0.082 mg s-1 while the largest depletion rates were observed in the EDTA experiments at 0.093 mg s-1. Changes in pH caused by the electrolysis of the electrodes is a likely underlying factor behind the mixed results, as these pH changes play a large role in altering the solubility of the metals in solution

Dual load-path fastener

A fastener system is provided for securing a component to supporting structure. The fastener system comprises a pair of cooperating fastener modules. The first module includes a first stationary member attached to the supporting structure and a first bolt member threadedly engaged with the first stationary member. The second module includes a second stationary member also attached to the supporting structure and a second bolt member threadedly engaged with the second stationary member. The second bolt member also extends freely through a longitudinal bore in the first bolt member. Head members on the first and second head members are mutually engaged for their unitary rotation and the first head member engages the component. When the head members are rotated in one direction, they are advanced toward the supporting structure thereby drawing the component toward the supporting structure. Rotation in the opposite direction is effective to cause the head members to retract from the supporting structure and thereby separate the component from the supporting structure. With this construction, upon fracture either of the first fastener means at a location away from the first head member or of the second fastener means at a location away from the second head member, upon rotation of the first head member in the one direction, the first head member nevertheless continues to advance toward the supporting structure

The epidemiology of work-related fatalities in Australia

Background: There is no on-going information on the number, rate or circumstances of work-related fatal injury in Australia. This thesis reports on a study aimed to identify and describe all work-related fatalities that occurred in Australia during the four-year period 1989 to 1992, in order to make a significant contribution to the effectiveness of activity designed to prevent work-related traumatic death. Methods: A broad definition of work was used, with particular focus on workers and bystanders. The study also included the injury-related deaths of volunteers, students, persons performing home duties and persons fatally injured on farms but not due to obvious farm work. The data were obtained primarily from coronial files. Files were found for 99.7% of the deaths of interest. Detailed results are presented on the work-related deaths of workers, bystanders and persons fatally injured while engaged in home duties. The results for workers are also compared with those from an earlier study of work-related fatalities in Australia, which covered the years 1982 to 1984 inclusive. Other aspects of work-related deaths are considered in detail, including the effect of employment arrangements; their coverage by occupational health and safety and compensation agencies; their handling by the coronial system; the role of External Cause codes in identifying and monitoring work-related injury deaths; and the reliability and validity of the definitions used to classify work-related injury deaths. Results: There were 2,413 persons fatally injured while working or commuting during the study period (1,787 working; 626 commuting), with a rate of death for working persons of 5.5 per 100,000 persons per year. This compared to the rate of 6.7 for working deaths during 1982 to 1984, with just under half of the decline probably due to changes in the industry distribution of the workforce. Another 802 persons were fatally injured as a result of someone else’s work activity, and 296 persons aged 15 years and over were fatally injured while undertaking active tasks in an unpaid and informal capacity in their own home or in someone else’s home. Thirty-four percent of working deaths were not covered by either occupational health and safety (OHS) or compensation agencies. A consideration of External Cause codes for the period 1979 to 1997 inclusive suggested there was a yearly decrease in the rate of workplace deaths of 2.6% per year, with less than half of this change due to industry changes in the workforce. Deaths occurring in a small number of particular circumstances were found to pose classification problems. Conclusion: Fatal work-related trauma remains an important problem for the Australian community. By understanding how and why these deaths occur, appropriate steps can be taken to prevent similar incidents recurring. It is expected that the results reported here, and other information that has arisen from the study, will make an important contribution to developing this understanding and preventing the occurrence of work- related traumatic death in Australia

Responses of 20 lake-watersheds in the Adirondack region of New York to historical and potential future acidic deposition

AbstractCritical loads (CLs) and dynamic critical loads (DCLs) are important tools to guide the protection of ecosystems from air pollution. In order to quantify decreases in acidic deposition necessary to protect sensitive aquatic species, we calculated CLs and DCLs of sulfate (SO42−)+nitrate (NO3−) for 20 lake-watersheds from the Adirondack region of New York using the dynamic model, PnET-BGC. We evaluated lake water chemistry and fish and total zooplankton species richness in response to historical acidic deposition and under future deposition scenarios. The model performed well in simulating measured chemistry of Adirondack lakes. Current deposition of SO42−+NO3−, calcium (Ca2+) weathering rate and lake acid neutralizing capacity (ANC) in 1850 were related to the extent of historical acidification (1850–2008). Changes in lake Al3+ concentrations since the onset of acidic deposition were also related to Ca2+ weathering rate and ANC in 1850. Lake ANC and fish and total zooplankton species richness were projected to increase under hypothetical decreases in future deposition. However, model projections suggest that lake ecosystems will not achieve complete chemical and biological recovery in the future

Experimental Investigation of Premixed Turbulent Combustion in High Reynolds Number Regimes using PLIF

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140710/1/6.2014-0314.pd

Conjugative Transposons and Their Cargo Genes Vary across Natural Populations of Rickettsia buchneri Infecting the Tick Ixodes scapularis

Rickettsia buchneri (formerly Rickettsia endosymbiont of Ixodes scapularis, or REIS) is an obligate intracellular endoparasite of the black-legged tick, the primary vector of Lyme disease in North America. It is noteworthy among the rickettsiae for its relatively large genome (1.8 Mb) and extraordinary proliferation of mobile genetic elements (MGEs), which comprise nearly 35% of its genome. Previous analysis of the R. buchneri genome identified several integrative conjugative elements named Rickettsiales amplified genomic elements (RAGEs); the composition of these RAGEs suggests that continued genomic invasions by MGEs facilitated the proliferation of rickettsial genes related to an intracellular lifestyle. In this study, we compare the genomic diversity at RAGE loci among sequenced rickettsiae that infect three related Ixodes spp., including two strains of R. buchneri and Rickettsia endosymbiont of Ixodes pacificus strain Humboldt, as well as a closely related species R. tamurae infecting Amblyomma testudinarium ticks. We further develop a novel multiplex droplet digital PCR assay and use it to quantify copy number ratios of chromosomal R. buchneri RAGE-A and RAGE-B to the single-copy gene gltA within natural populations of I. scapularis. Our results reveal substantial diversity among R. buchneri at these loci, both within individual ticks as well as in the I. scapularis population at large, demonstrating that genomic rearrangement of MGEs is an active process in these intracellular bacteria

Automatic Safety Brake for a Snowboard

Runaway snowboards pose a very hazardous threat to skiers, snowboarders, and all other patrons of ski resorts. The goal of this project was to design, prototype, and test an automatic safety snowboard brake which activates and deactivates automatically, and remains functional when the board is not in use. The project team researched existing patents and designs for both ski and snowboard brakes, analytically designed a spring loaded piston -- cylinder brake mechanism and a four bar driving mechanism, performed finite element stress analysis on the critical components, selected the material, created a rapid prototype, and tested the functionality of the brake under a variety of realistic conditions. These methods yielded a successful, fully functional automatic snowboard safety brake