8,148 research outputs found

    Mapping Hong Kong’s Atlas

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    Rooted in the broader project of representing Hong Kong through the visual and literary arts, the Hong Kong Atlas book series seeks to build a set of heritage-based networks through a literary series consisting primarily of paperback and digital editions, including bilingual poetry collections. The individual voices of the authors and translators combine to reorient the complexities of memory in relation to Hong Kong’s constantly shifting pasts

    Risk Assessment for Developmental Toxicity: Airborne Occupational Exposure to Ethanol and Iodine

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    Dean Mattison explains hazard identification, hazard characterization and exposure characterization as furnishing a foundation for Risk assessment generally. He then illustrates their application in assessing the fetal Risk posed by two common substances. Ultimately, he argues that only after Risks have been so examined can women of child bearing age (or anyone) decide what if any measures are appropriate to avoid them

    The effects of a 12-week leisure centre-based, group exercise intervention for people moderately affected with multiple sclerosis: a randomized controlled pilot study

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    <b>Objective:</b> To establish the effects of a 12-week, community-based group exercise intervention for people moderately affected with multiple sclerosis. <b>Design:</b> Randomised controlled pilot trial. <b>Setting:</b> Two community leisure centres. <b>Participants:</b> Thirty-two participants with multiple sclerosis randomised into intervention or control groups. <b>Intervention:</b> The intervention group received 12 weeks of twice weekly, 60-minute group exercise sessions, including mobility, balance and resistance exercises. The control group received usual care. <b>Main outcome measures:</b> An assessor blinded to group allocation assessed participants at baseline, after eight weeks and after 12 weeks. The primary outcome measure was 25-foot (7.6 m) walk time, secondary outcomes assessed walking endurance, balance, physical function, leg strength, body mass index, activity levels, fatigue, anxiety and depression, quality of life and goal attainment. <b>Results:</b> The intervention made no statistically significant difference to the results of participants’ 25-foot walk time. However the intervention led to many improvements. In the intervention group levels of physical activity improved statistically between baseline and week 8 (P < 0.001) and baseline and week 12 (P = 0.005). Balance confidence results showed a significant difference between baseline and week 12 (P = 0.013). Good effect sizes were found for dynamic balance (d = 0.80), leg strength (d = 1.33), activity levels (d = 1.05) and perceived balance (d = 0.94). <b>Conclusion:</b> The results of the study suggest that community-based group exercise classes are a feasible option for people moderately affected with multiple sclerosis, and offer benefits such as improved physical activity levels, balance and leg strength

    Techno-economic analysis of chemical looping combustion with humid air turbine power cycle

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    Power generation from fossil fuel-fired power plant is the largest single source of CO₂ emission. CO₂ emission contributes to climate change. On the other hand, renewable energy is hindered by complex constraints in dealing with large scale application and high price. Power generation from fossil fuels with CO₂ capture is therefore necessary to meet the increasing energy demand, and reduce the emission of CO₂. This paper presents a process simulation and economic analysis of the chemical looping combustion (CLC) integrated with humid air turbine (HAT) cycle for natural gas-fired power plant with CO₂ capture. The study shows that the CLC–HAT including CO₂ capture has a thermal efficiency of 57% at oxidizing temperature of 1200 °C and reducer inlet temperature of 530 °C. The economic evaluation shows that the 50 MWth plant with a projected lifetime of 30 years will have a payback period of 7 years and 6 years for conventional HAT and CLC–HAT cycles respectively. The analysis indicates that CLC–HAT process has a high potential to be commercialised

    A Novel Approach for Effective Dose Measurements in Dual-Energy

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    <p><bold>Purpose:</bold></p><p>Our goal was to test a novel concept approximating organ dose measurements using the single mean energy of the two sources in dual-energy (DE) CT environment. Therefore, the purpose of this study was two-fold: (1) To obtain experimental validation of dose equivalency between MOSFET and ion chamber (as gold standard) under a dual-energy environment; (2) To estimate the effective dose (ED) using MOSFET detectors and an anthropomorphic phantom in DE CT scans.</p><p><bold>Materials and Methods:</bold></p><p>A commercial dual source CT (DSCT) scanner was employed for the study. The scanner was operated at 80kV/140kV (Sn added) using an abdomen/pelvis scanning protocol. A five-phase approach was used. Specific goals for each phase are as follows: (1) Characterize the mean energy from the combined clinical 80kV/Sn140kV beams; (2) Estimate the f-factor for tissues from the mean energy; (3) Calibrate the MOSFET detectors using the mean energy; (4) Validate MOSFET calibration with a CTDI phantom; (5) Measure organ doses for a typical abdomen/pelvis scan using a male anthropomorphic phantom and derive ED using ICRP 103 tissue weighting factors. For validation of dose equivalency, a MOSFET detector and ion chamber measured the dose at the center cavity of a CTDI body phantom. A student t-test was used to determine if the difference between the two was statistically significant.</p><p><bold>Results:</bold></p><p>The mean energy was calculated to be 67 kVp based on the corresponding spectra for the clinical DE beams. Using the Mean Energy Method, the tissue dose in the center cavity of the CT body phantom was 2.08 ± (2.70%) cGy with an ion chamber and 2.20 ± (4.82%) cGy with MOSFET respectively with a percent difference of 5.91% between the two measurements. The results (p = 0.15) showed no statistically significant difference. ED for DE abdomen/pelvis scan was calculated as 5.01 ± (2.34%) mSv by the MOSFET method and 5.56 mSv by the DLP method respectively.</p><p><bold>Conclusion:</bold></p><p>There has been no physical method to measure organ doses in DE CT scans. We have developed and validated a novel approach, the Mean Energy Method - for organ dose estimation in DE CT scans. ED from the anthropomorphic phantom compared well (within 11%) between the MOSFET method and DLP method.</p>Thesi

    A Tale of Two Professions: The Third-Party Liability of Accountants and Attorneys for Negligent Misrepresentation

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    To whom does a professional owe a duty of care when providing professional services?1 The traditional answer, grounded in principles of contractual privity, is that professionals are liable for negligence to their clients, and perhaps to third-party beneficiaries of the client-professional relationship, but that their noncontractual obligations generally extend no further than a duty not to commit fraud.2 In the past two decades, however, courts have become increasingly willing to hold a wide range of professionals liable for their negligence to parties outside the chain of privity. 3 The accompanying growth of third-party4 lawsuits alleging professional negligence and in particular alleging negligent misrepresentation by accountants or attorneys, raises serious questions for professionals concerning their legal and ethical obligations to nonclients

    Atomic hydrogen maser measurements with wall surfaces of carbon tetrafluoride

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    The principal objectives of the Smithsonian Astrophysical Observatory cold maser research programs are given. This work is aimed principally at understanding more about the interaction of hydrogen atoms with wall coatings of fluorinated ethylene propylene (Dupont Teflon FEP-120 co-polymer) and of carbon tetrafluoride (CE4). The principal measured quantity in these experiments is the wall shift of the maser's output frequency. The wall shift per atomic collision was calculated from the measured wall frequency shift. This assumes that the wall surface area is smooth on a molecular scale

    The clinical- and cost-effectiveness of functional electrical stimulation and ankle-foot orthoses for foot drop in Multiple Sclerosis: a multicentre randomized trial

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    Objective: To compare the clinical- and cost-effectiveness of ankle-foot orthoses (AFOs) and functional electrical stimulation (FES) over 12 months in people with Multiple Sclerosis with foot drop. Design: Multicentre, powered, non-blinded, randomized trial. Setting: Seven Multiple Sclerosis outpatient centres across Scotland. Subjects: Eighty-five treatment-naïve people with Multiple Sclerosis with persistent (>three months) foot drop. Interventions: Participants randomized to receive a custom-made, AFO (n = 43) or FES device (n = 42). Outcome measures: Assessed at 0, 3, 6 and 12 months; 5-minute self-selected walk test (primary), Timed 25 Foot Walk, oxygen cost of walking, Multiple Sclerosis Impact Scale-29, Multiple Sclerosis Walking Scale-12, Modified Fatigue Impact Scale, Euroqol five-dimension five-level questionnaire, Activities-specific Balance and Confidence Scale, Psychological Impact of Assistive Devices Score, and equipment and National Health Service staff time costs of interventions. Results: Groups were similar for age (AFO, 51.4 (11.2); FES, 50.4(10.4) years) and baseline walking speed (AFO, 0.62 (0.21); FES 0.73 (0.27) m/s). In all, 38% dropped out by 12 months (AFO, n = 21; FES, n = 11). Both groups walked faster at 12 months with device (P < 0.001; AFO, 0.73 (0.24); FES, 0.79 (0.24) m/s) but no difference between groups. Significantly higher Psychological Impact of Assistive Devices Scores were found for FES for Competence (P = 0.016; AFO, 0.85(1.05); FES, 1.53(1.05)), Adaptability (P = 0.001; AFO, 0.38(0.97); FES 1.53 (0.98)) and Self-Esteem (P = 0.006; AFO, 0.45 (0.67); FES 1 (0.68)). Effects were comparable for other measures. FES may offer value for money alternative to usual care. Conclusion: AFOs and FES have comparable effects on walking performance and patient-reported outcomes; however, high drop-outs introduces uncertainty

    New Clock Comparison Searches for Lorentz and CPT Violation

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    We present two new measurements constraining Lorentz and CPT violation using the Xe-129 / He-3 Zeeman maser and atomic hydrogen masers. Experimental investigations of Lorentz and CPT symmetry provide important tests of the framework of the standard model of particle physics and theories of gravity. The two-species Xe-129 / He-3 Zeeman maser bounds violations of CPT and Lorentz symmetry of the neutron at the 10^-31 GeV level. Measurements with atomic hydrogen masers provide a clean limit of CPT and Lorentz symmetry violation of the proton at the 10^-27 GeV level.Comment: 11 pages, 5 figures. To appear in the Proceedings of the 3rd International Symposium on Symmetries in Subatomic Physic
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