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262 results on '"Hutchins, Stephen"'

2. The effects of rocker sole profiles on gait : implications for claudicants

Author

Hutchins, Stephen William

Subjects
616.131
Abstract

Introduction Intermittent claudication (1C) is a vascular condition which limits the distance subjects can walk before experiencing pain in the lower limb calf muscles due to limitation of vascular supply. Orthotic intervention evidenced in the literature has previously included the use of rocker profiles or raised heels to increase the pain-free walking distance, but variable results have been demonstrated. This study aims to design a rocker profile with the specific objectives of increasing the pain free walking distance demonstrated by claudicants and reducing their calf pain once claudicating. Method Twelve volunteer healthy subjects, age range 25 to 54 years (mean: 32.7 +/- 11.3), initially undertook separate walking trials in gait laboratory conditions with shoes adapted with three different rocker sole profiles; the one-curve toe-only profile, the two-curve profile and the three-curve profile, plus a shoe adapted with a moderate (12mm) heel raise. Measurements and comparisons of gait kinetics and kinematics (Qualysis, Sweden), and the electromyographical (EMG) activity (Noraxon, USA) of the medial and lateral gastrocnemius muscles, plus that of soleus and tibialis anterior, were undertaken. The most effective condition compared to a baseline un-adapted shoe was then tested during walking trials with claudicants (n=8, mean age 66 +/- 9 years) to ascertain its efficacy in reducing the pain-free walking distance to claudication and the severity of the pain once claudicating. Results All changes from the baseline shoe were set at a level of significance of p<0.05 The three-curve rocker profile placed the ankle joint into a relatively plantarflexed position compared to baseline at loading response (/?=0.00), mid stance (p=0.00) and terminal stance (/?=0.00), and significantly reduced total sagittal plane ankle range of motion compared to baseline (/7=0.00). The moderate heel raise also induced ankle plantarflexion at loading response (p=0.00) but increased ankle range of motion during second rotational phase of gait (/?=0.00) compared to baseline. The one-curve rocker profile induced a sagittal plane dorsiflexion shift at the ankle during mid stance (/?=0.00). The three-curve rocker profile was the most effective test condition in reducing both the externally-applied ankle dorsiflexion moment (/?=0.00) and ankle power generation (p=0.00) during stance phase of gait compared to baseline. Changes to muscle EMG values by all the test conditions were not statistically significant. Claudicant walking trials when wearing the three curve rocker profile demonstrated a statistically significant increase in pain-free walking distance to claudication (/?=0.00) and a reduction in claudication pain once claudicating (/?=0.00). Conclusion This study demonstrates that a specifically-designed rocker profile can significantly alter gait kinetics and kinematics and produce a statistically different increase in the pain-free walking distance of claudicants whilst also significantly reducing their pain levels once claudicating.

Published
2007

10. Combined laboratory/field study on the use of nitrate for in situ bioremediation of a fuel-contaminated aquifer

Author

Hutchins, Stephen R. and Miller, Dennis E.

Subjects
Bioremediation -- Research, Alkylbenzene -- Research, Air bases -- Environmental aspects, Environmental issues, Science and technology
Abstract

The use of nitrate in the bioremediation of fuel-contaminated groundwater was shown to offer only moderate improvement in contaminant reduction. Core material removed from the nitrate treated and control areas showed varying degrees of alkylbenzene removal governed by the denitrifying and iron-reducing characteristics of the soil column above the aquifer. The reductions in the aquifer's contaminants were shown to be a function of anaerobic bioremediation rather than a direct effect of nitrification.

Published
1998

11. Reduced permeability in groundwater remediation systems: role of mobilized colloids and injected chemicals

Author

Wiesner, Mark R., Grant, Mae C., and Hutchins, Stephen R.

Subjects
Eglin Air Force Base, Florida -- Waste management, Groundwater flow -- Environmental aspects, Bioremediation -- Research, Aquifers -- Environmental aspects, Water pollution -- Environmental aspects, Environmental issues, Science and technology
Abstract

The re-deposition of colloids mobilized in the aquifer and gas binding due to hydrogen peroxide decomposition, rather than to iron precipitation, likely caused the reduced permeability of the aquifer near delivery systems. This was found following an investigation of the effects of iron oxidation state and concentration, the presence of colloidal materials and the impact of nutrient solutions and hydrogen peroxide in the feedwater on the permeability of the aquifer material in the bioremediation experience at Eglin Air Force Base in Florida. Bioremediation at the site was stopped because of the failure of delivery systems owing to iron precipitation.

Published
1996

12. Surface application system for in situ ground-water bioremediation: site characterization and modeling

Author

Sweed, Howard G., Bedient, Philip B., and Hutchins, Stephen R.

Subjects
Bioremediation -- Methods -- Research, Water, Underground -- Research -- Methods, Water -- Purification, Earth sciences, Research, Methods
Abstract

Introduction Accidental leaks and spills of petroleum products resulting from deteriorating storage tanks, faulty piping, and poor fuel management practices have resulted in widespread contamination of ground water. According to [...]

Published
1996

13. Inhibition of alkylbenzene biodegradation under denitrifying conditions by using the acetylene block technique

Author

Hutchins, Stephen R.

Subjects
Biodegradation -- Measurement, Denitrification -- Research, Microbiological assay -- Methods, Biological sciences
Abstract

The principle of the acetylene block technique, which is used to assess denitrifying activity, involves the prevention of nitrous oxide oxidation, thereby allowing the accumulation of the intermediate to facilitate the quantitation of rates and activity. An investigation was conducted to verify whether the inclusion of acetylene can prevent the biodegradation of certain alkylbenzenes under denitrifying conditions. The results confirmed the inhibitory effect of acetylene, even in acclimated samples of subsurface aquifer material. Therefore, the results demonstrate a potential for underestimation of biodegradation rates using the acetylene block technique.

Published
1992

26. The influence of thermoplastic thoraco lumbo sacral orthoses on standing balance in subjects with idiopathic scoliosis

Author

Khanal, Minoo, primary, Arazpour, Mokhtar, additional, Bahramizadeh, Mahmood, additional, Samadian, Mohammad, additional, Hutchins, Stephen W, additional, Kashani, Reza Vahab, additional, Mardani, Mohammad A, additional, Tari, Hossein Vahid, additional, Aboutorabi, Atefeh, additional, Curran, Sarah, additional, and Sadeghi, Heidar, additional

Published
2016
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50. Single Pass Optical Profile Monitoring

Author

Jung, R, Ferioli, Gianfranco, and Hutchins, Stephen

Subjects
Physics::Accelerator Physics, Accelerators and Storage Rings
Abstract

Beam profiles are acquired in transfer lines to monitor extracted beams and compute their emittance. Measurements performed on the first revolutions of a ring will evaluate the matching of a chain of accelerators. Depending on the particle type and energy, these measurements are in general performed with screens, making either use of Luminescence or Optical Transition Radiation [OTR], and the generated beam images are acquired with sensors of various types. Sometimes the beam position is also measured this way. The principle, advantages and disadvantages of both families of screens will be discussed in relation with the detectors used. Test results with beam and a possible evaluation method for luminescent screens will be presented. Finally other optical methods used will be mentioned for completeness.

Published
2003

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