5,390 research outputs found

    A mechanistic study of the EC′ mechanism – the split wave in cyclic voltammetry and square wave voltammetry

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    In this paper, a detailed investigation of electrochemical reactions coupled with homogenous chemical steps using cyclic voltammetry (CV) and square wave voltammetry (SWV) was carried out to study the electrocatalytic (EC’) mechanism. In CV, parameters including scan rate, electrode material and redox reactant were investigated while in SWV, parameters including substrate concentrations and frequencies were altered to demonstrate EC’ mechanism. Mechanistic studies focused on the EC’ mechanism using L-cysteine with ferrocenecarboxylic acid and 1,1 ′-ferrocenedicarboxylic acid respectively. Voltammetric responses were recorded and under conditions of high chemical rate constant and low substrate concentration, a split wave was observed in both CV and SWV studies

    Brief Note: Limnetic Larval Fish in the Nearshore Zone of the South Shore of the Central Basin of Lake Erie

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    Author Institution: Center for Lake Erie Area Research, The Ohio State University ; Department of Biology, John Carroll Universit

    Helminth Parasites of the Brown-Headed Cowbird, Molothrus Ater Ater, from Ohio

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    Author Institution: Department of Zoology, The Ohio State UniversityA total of 166 Brown-headed Cowbirds was examined for the occurrence of helminth parasites. Of these, 116 were collected on the campus of The Ohio State University, Franklin County, Ohio, from January 1964 through February 1965. The remainder of the birds were collected on South Bass Island, Ottawa County, Ohio, from July 1969 through July 1970. Twenty species of helminth parasites are recorded from these birds. Sixteen of these helminth species are new host records: the trematodes Conspicuum icteridorum, Lutztrema sp., Prosthogonimus macrorchis, Tanaisia zarudnyi, and Zonorchis alveyi; the cestode Orthoskrjabinia rostellata; the nematodes Capillaria caudinflata, C. ovopunctatum, C. tridens, Chandlerella quiscali, Diplotriaena bargusinica, Microtetrameres sp., Splendidofilaria algonquinensis, Syngamus trachea, and Tetrameres americana; and the acanthocephalan Plagiorhynchus formosus

    The development and characteristics of a hand-held high power diode laser-based industrial tile grout removal and single-stage sealing system

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    As the field of laser materials processing becomes ever more diverse, the high power diode laser (HPDL) is now being regarded by many as the most applicable tool. The commercialisation of an industrial epoxy grout removal and single-stage ceramic tile grout sealing process is examined through the development of a hand-held HPDL device in this work. Further, an appraisal of the potential hazards associated with the use of the HPDL in an industrial environment and the solutions implemented to ensure that the system complies with the relevant safety standards are given. The paper describes the characteristics and feasibility of the industrial epoxy grout removal process. A minimum power density of approximately 3 kW/cm2 was found to exist, whilst the minimum interaction time, below which there was no removal of epoxy tile grout, was found to be approximately 0.5 s. The maximum theoretical removal rate that may be achievable was calculated as being 65.98 mm2/s for a circular 2 mm diameter beam with a power density of 3 kW/cm2 and a traverse speed of 42 mm/s. In addition, the characteristics of the single-stage ceramic tile grout sealing are outlined. The single-stage ceramic tile grout sealing process yielded crack and porosity free seals which were produced in normal atmospheric conditions. Tiles were successfully sealed with power densities as low as 550 W/cm2 and at rates of up to 420 mm/min. In terms of mechanical, physical and chemical characteristics, the single-stage ceramic tile grout was found to be far superior to the conventional epoxy tile grout and, in many instances, matched and occasionally surpassed that of the ceramic tiles themselves

    Coherence, incoherence and scaling along the c axis of YBa_2Cu_3O_{6+x}

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    The optical properties of single crystals of YBa_2Cu_3O_{6+x} have been examined along the c axis above and below the critical temperature (T_c) for a wide range of oxygen dopings. The temperature dependence of the optically-determined value of the dc conductivity (\sigma_{dc}) in the normal state suggests a crossover from incoherent (hopping-type) transport at lower oxygen dopings (x \lesssim 0.9) to more coherent anisotropic three-dimensional behavior in the overdoped (x \approx 0.99) material at temperatures close to T_c. The assumption that superconductivity occurs along the c axis through the Josephson effect yields a scaling relation between the strength of the superconducting condensate (\rho_{s,c}, a measure of the number of superconducting carriers), the critical temperature, and the normal-state c-axis value for \sigma_{dc} just above T_c; \rho_{s,c} \propto \sigma_{dc} T_c. This scaling relation is observed along the c axis for all oxygen dopings, as well as several other cuprate materials. However, the agreement with the Josephson coupling model does not necessarily imply incoherent transport, suggesting that these materials may indeed be tending towards coherent behavior at the higher oxygen dopings.Comment: Six pages with four figures and one tabl

    Protocol of a natural experiment to evaluate a supermarket intervention to improve food purchasing and dietary behaviours of women (WRAPPED study) in England: a prospective matched controlled cluster design

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    Introduction: Poor diet is a leading risk factor for non-communicable diseases and costs the National Health Service £5.8 billion annually. Product placement strategies used extensively in food outlets, like supermarkets, can influence customers’ preferences. Policy-makers, including the UK Government, are considering legislation to ensure placement strategies promote healthier food purchasing and dietary habits. High-quality scientific evidence is needed to inform future policy action. This study will assess whether healthier placement strategies in supermarkets improve household purchasing patterns and the diets of more than one household member. Methods and analyses: This natural experiment, with a prospective matched controlled cluster design, is set in discount supermarkets across England. The primary objective is to investigate whether enhanced placement of fresh fruit and vegetables improves household-level purchasing of these products after 6 months. Secondary objectives will examine: (1) differences in intervention effects on purchasing by level of educational attainment, (2) intervention effects on the dietary quality of women and their young children, (3) intervention effects on store-level sales of fruit and vegetables and (4) cost-effectiveness of the intervention from individual, retailer and societal perspectives. Up to 810 intervention and 810 control participants will be recruited from 18 intervention and 18 matched control stores. Eligible participants will be women aged 18–45 years, who hold a loyalty card and shop in a study store. Each control store will be matched to an intervention store on: (1) sales profile, (2) neighbourhood deprivation and (3) customer profile. A detailed process evaluation will assess intervention implementation, mechanisms of impact and, social and environmental contexts. Ethics and dissemination: Ethical approval was obtained from the University of Southampton, Faculty of Medicine Ethics Committee (ID 20986.A5). Primary, secondary and process evaluation results will be submitted for publication in peer-reviewed scientific journals and shared with policy-makers. Trial registration number: NCT03573973; Pre-results

    Influence of Anaesthesia on Mobilisation Following Hip Fracture Surgery : An Observational Study: 麻醉技術對髖部骨折病人術後活動能力的影響:一項觀察性研究

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    Background Anaesthetic technique can influence mortality and morbidity following hip fracture surgery. However, its influence on postoperative mobilisation is not clear. In this study, we evaluated the influence of anaesthetic technique on postoperative mobilisation. Methods In this prospective observational study, we included all consecutive patients who underwent surgery for hip fracture between 1 January 2012 and 31 December 2013 at our institution. Any patients who died prior to mobilisation or who could not be followed up after surgery were excluded. Data was collected on demographics, clinical characteristics, anaesthesia technique and surgical factors, and date and time of admission, operation, first mobilisation and discharge. Results Of the 1040 patients included in the analysis, 264 received general anaesthesia only (Group GA), 322 received general anaesthesia with regional anaesthesia (Group GARA), and 454 received central neuraxial blockade anaesthesia with or without sedation (Group CNB). There was no significant difference in age (p = 0.56), sex (p = 0.23), number of comorbidities (p = 0.06), residential status (p = 0.18), time to surgery (p = 0.10) and length of hospital stay (p = 0.30) between the three groups. There was a statistically significant difference in ASA grade (p = 0.01), implant type used (p = 0.04), grade of operating surgeon (p = 0.02) and grade of anaesthetist during surgery (p = 0.004) among the three groups. Patients in Group GARA had a median time-to-first mobilisation of 23.8 hours after surgery, compared to 24.1 hours in Group GA and 24.3 hours in Group CNB. This difference was not statistically significant after controlling for confounding factors (p = 0.45). Conclusion Our results show that anaesthetic technique does not influence time-to-first mobilisation after hip fracture surgery
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