188 research outputs found

    <Contributed Talk 15>An Energy Harvester for Broadband Vibrations

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    [Date] November 28 (Mon) - December 2 (Fri), 2011: [Place] Kyoto University Clock Tower Centennial Hall, Kyoto, JAPA

    Nonuniform buckled beam energy harvesting: experimental validation, modeling, and dynamic analysis

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    Vibrational energy harvesting is a subject that has received much attention as a possible replacement for remote battery-operated sensor networks. We describe a vibrational energy harvester with an asymmetric buckled beam which is constructed out of commercially available components, and has demonstrated a significantly increased bandwidth compared to a device exhibiting linear resonance. This particular beam could not be mathematically modeled by existing analytic techniques, so a method is developed to produce a reduced order analytic model based on a finite element representation of the system. Moreover, we present an argument for why common single-mode Galerkin projection models are incapable of accurately reproducing snap-through behavior at higher than infinitesimal buckling levels. The model developed here demonstrates good agreement with the behavior exhibited by the experimental system around the parameter region of high power output, as evidenced by similar phase portraits and frequency response plots. Further, an argument is presented for why current trends towards testing non-linear systems with constant acceleration frequency sweeps are misleading, and an alternative comparison platform is suggested. The model is analyzed from a dynamical systems perspective, and it is shown that the transitions between high and low power output can be associated with a period doubling cascade or a boundary crisis where a chaotic attractor stabilizes through an intermittency transition. Chaotic behavior is observed to be closely related to the high power output region, but it is possible to have appreciable power output with a periodic response. Potential future work involves analyzing alternate beam configurations in search of an optimal solution to the high power output bandwidth problem

    Series Hybrid Vehicles and Optimized Hydrogen Engine Design

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    Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an available engine at the Sandia Combustion Research Facility demonstrated NO{sub x} emissions of 10 to 20 ppm at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid vehicle simulation studies indicate that exhaust NO{sub x} concentrations must be less than 180 ppm to meet the 0.2 g/mile California Air Resources Board ULEV or Federal Tier II emissions regulations. We have designed and fabricated a first generation optimized hydrogen engine head for use on an existing single cylinder Onan engine. This head currently features 14.8:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses

    A retrospective cohort study of the influence of lifestyle factors on survival of patients undergoing surgery for colorectal cancer.

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    Aim: Several modifiable and non-modifiable health related behaviours are associated with the incidence of Colorectal Cancer (CRC), but there is little research on their association with survival. The project aimed to investigate possible relationships between modifiable behavioural factors and outcomes on a study cohort of CRC patients undergoing potentially curative surgery. Method: A retrospective cohort study was carried out of patients diagnosed with non-metastatic CRC undergoing elective curative surgery (January 2011 - December 2012), residing in the NHS Greater Glasgow &amp; Clyde (NHSGGC) area, UK. Data were obtained from the Scottish Cancer Registry, National Scottish Death Records. Pre-operative assessment of smoking, alcohol consumption, nurse-measured body mass index (BMI) and exercise levels were recorded and patients were followed until death or censorship. Survival analysis was carried out and proportional hazards assumptions were assessed graphically using plots and were then formally tested using the PHTEST procedure in STATA. Results: Of the initial 527 patients, 181 (34%) satisfied the inclusion criteria. The total duration of follow up was 480 person-years. At the pre-operative assessment, 75% were overweight or obese, 10.6% were current smokers, 13.1% recorded excess alcohol consumption and 8.5% had physical difficulty climbing stairs. Age, BMI, histopathological stage and physical capacity all independently affected survival (P&lt;0.05). Overweight patients (HR 2.81) and those who had difficulty climbing stairs (HR 3.31) had a significantly poorer survival. Conclusion: The study found evidence that pre-operative exercise capacity and BMI are important independent prognostic factors of survival in patients undergoing curative surgery for CRC

    Development and pilot evaluation of a personalized decision support intervention for low risk prostate cancer patients.

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    ObjectivesDevelopment and pilot evaluation of a personalized decision support intervention to help men with early-stage prostate cancer choose among active surveillance, surgery, and radiation.MethodsWe developed a decision aid featuring long-term survival and side effects data, based on focus group input and stakeholder endorsement. We trained premedical students to administer the intervention to newly diagnosed men with low-risk prostate cancer seen at the University of California, San Francisco. Before the intervention, and after the consultation with a urologist, we administered the Decision Quality Instrument for Prostate Cancer (DQI-PC). We hypothesized increases in two knowledge items from the DQI-PC: How many men diagnosed with early-stage prostate cancer will eventually die of prostate cancer? How much would waiting 3&nbsp;months to make a treatment decision affect chances of survival? Correct answers were: "Most will die of something else" and "A little or not at all."ResultsThe development phase involved 6 patients, 1 family member, 2 physicians, and 5 other health care providers. In our pilot test, 57 men consented, and 44 received the decision support intervention and completed knowledge surveys at both timepoints. Regarding the two knowledge items of interest, before the intervention, 35/56 (63%) answered both correctly, compared to 36/44 (82%) after the medical consultation (P&nbsp;=&nbsp;.04 by chi-square test).ConclusionsThe intervention was associated with increased patient knowledge. Data from this pilot have guided the development of a larger scale randomized clinical trial to improve decision quality in men with prostate cancer being treated in community settings

    Eddy sensors for small diameter stainless steel tubes.

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    The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor

    Quality of life for men with metastatic castrate-resistant prostate cancer participating in an aerobic and resistance exercise pilot intervention

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    Background: Following a prostate cancer diagnosis, disease and treatment-related symptoms may result in diminished quality of life (QoL). Whether exercise improves QoL in men with metastatic castrate-resistant prostate cancer (mCRPC) is not fully understood. Methods: We conducted a 3-arm pilot randomized controlled trial to assess the feasibility, acceptability, safety, and efficacy of a 12-week remotely monitored exercise program among men with mCRPC. Here we report qualitative changes in QoL, consistent with the guidelines for pilot trials. Men were randomized to control, aerobic exercise, or resistance exercise. Exercise prescriptions were based on baseline cardiorespiratory and strength assessments. QoL outcomes were evaluated using self-reported questionnaires (e.g., QLQ-C30, PROMIS Fatigue, Pittsburgh Sleep Quality Index (PSQI), EPIC-26) collected at baseline and 12 weeks. Results: A total of 25 men were randomized (10 control, 8 aerobic, 7 resistance). Men were predominately white (76 %) with a median age of 71 years (range: 51 – 84) and 10.5 years (range: 0.9 – 26.3) post prostate cancer diagnosis. The men reported poor sleep quality and high levels of fatigue at enrollment. Other baseline QoL metrics were relatively high. Compared to the controls at 12 weeks, the resistance arm reported some improvements in social function and urinary irritative/obstruction symptoms while the aerobic arm reported some improvements in social function and urinary incontinence, yet worsening nausea/vomiting. Compared to the resistance arm, the aerobic arm reported worse urinary irritative/obstruction symptoms and self-rated QoL, yet some improvements in emotional function, insomnia, and diarrhea. Conclusions: The 3-month exercise intervention pilot appeared to have modest effects on QoL among mCRPC survivors on ADT. Given the feasibility, acceptability, and safety demonstrated in prior analyses, evaluation of the effect of the intervention on QoL in a larger sample and for extended duration may still be warranted

    Intense exercise for survival among men with metastatic castrate-resistant prostate cancer (INTERVAL-GAP4): A multicentre, randomized, controlled phase III study protocol

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    Introduction: Preliminary evidence supports the beneficial role of physical activity on prostate cancer outcomes. This phase III randomised controlled trial (RCT) is designed to determine if supervised high-intensity aerobic and resistance exercise increases overall survival (OS) in patients with metastatic castrate-resistant prostate cancer (mCRPC). Methods and analysis: Participants (n=866) must have histologically documented metastatic prostate cancer with evidence of progressive disease on androgen deprivation therapy (defined as mCRPC). Patients can be treatmentnaive for mCRPC or on first-line androgen receptor-targeted therapy for mCRPC (ie, abiraterone or enzalutamide) without evidence of progression at enrolment, and with no prior chemotherapy for mCRPC. Patients will receive psychosocial support and will be randomly assigned (1:1) to either supervised exercise (high-intensity aerobic and resistance training) or self-directed exercise (provision of guidelines), stratified by treatment status and site. Exercise prescriptions will be tailored to each participant’s fitness and morbidities. The primary endpoint is OS. Secondary endpoints include time to disease progression, occurrence of a skeletal-related event or progression of pain, and degree of pain, opiate use, physical and emotional quality of life, and changes in metabolic biomarkers. An assessment of whether immune function, inflammation, dysregulation of insulin and energy metabolism, and androgen biomarkers are associated with OS will be performed, and whether they mediate the primary association between exercise and OS will also be investigated. This study will also establish a biobank for future biomarker discovery or validation. Ethics and dissemination: Validation of exercise as medicine and its mechanisms of action will create evidence to change clinical practice. Accordingly, outcomes of this RCT will be published in international, peer-reviewed journals, and presented at national and international conferences. Ethics approval was first obtained at Edith Cowan University (ID: 13236 NEWTON), with a further 10 investigator sites since receiving ethics approval, prior to activation. Trial registration number: NCT02730338
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