190 research outputs found

    Investigation into the use of zero angle ultrasonic probe array for defect detection and location

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    The steel industry like any other manufacturing process is under constant pressure to deliver higher quality defect free material at lower cost to customers. This push for zero defects has led to improved manufacturing processes and the need for more reliable, faster defect testing methods. Ultrasound fundamentally provides a mechanical stress, produced by tensile, compressive, shearing or flexural forces, which are of such low intensity that no material damage occurs. The remit of the project was to investigate and develop the latent potential within the Present automated ultrasonic immersion system using an array of normal angle probes, used for billet inspection. The work presented in this thesis describes the research undertaken to develop a system using, 10mm diameter, standard zero angled 5MHz ultrasonic transducers. The transducers were used at linear separation distances of between 22.5mm and 45mm set in a typical 8-probe array orientation. The developed technique is potentially transferable to other ultrasonic multi-probe array applications and demonstrates that time of flight diffraction can be realised using normal probes, and termed Normal Probe Diffraction, (NPD). The technique located defects, using the intersection of ellipses, with an error of <0.5% of the signal transit distance and, with the application of a correlation filter, improved the Signal to Noise Ratio (SNR) from—20dB to 17.0dB

    McDowell on Skepticism, Disjunctivism, and Transcendental Arguments

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    McDowell’s disjunctive account of perceptual knowledge contains a novel addition to his interesting response to skepticism by placing within it a transcendental argument. It is not clear that such addition strengthens it. McDowell’s disjunctivism seems to involve both epistemological and experience- theoretical commitments. It is a two-sided structure, from which it could be raised questions about the assumed relation between the two sides. The purpose of this paper is to make some progress with evaluating McDowell’s contribution to the discussion on perceptual knowledge and illuminate more general aspects of the debate about disjunctivism.La concepción disyuntiva del conocimiento perceptual de McDowell contiene una novedosa adición a su interesante respuesta al escepticismo introduciendo un argumento trascendental. No está claro que esta adición fortalezca su respuesta. El disyuntivismo de McDowell parece envolver compromisos tanto epistemológicos como teórico-empíricos. Se trata de una estructura de dos lados de la que surgen preguntas acerca de la supuesta relación entre ambos lados. El propósito de este trabajo es realizar algunos progresos en la evaluación de la contribución de McDowell a la discusión sobre el conocimiento perceptual y aclarar aspectos más generales del debate en torno al disyuntivismo

    The Laser MicroJet® (LMJ) - A multi-solution technology for high quality micro-machining

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    The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1], The main issues by using these lasers are heat damages, contamination and low ablation rates, This report examines on the application of the Laser MicroJet® (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials

    What the disjunctivist is right about

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    There is a traditional conception of sensory experience on which the experiences one has looking at, say, a cat could be had by someone merely hallucinating a cat. Disjunctivists take issue with this conception on the grounds that it does not enable us to understand how perceptual knowledge is possible. In particular, they think, it does not explain how it can be that experiences gained in perception enable us to be in ‘cognitive contact’ with objects and facts. I develop this chal- lenge to the traditional conception and then show that it is possible to accommo- date an adequate account of cognitive contact in keeping with the traditional conception. One upshot of the discussion is that experiences do not bear the explanatory burden placed upon them by disjunctivists

    Field methods for above and belowground biomass estimation in plantation forests

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    A practical and cost-effective destructive sampling method for estimating above and belowground biomass of Corymbia citriodora subspecies variegata grown in plantations is described. The methodology includes details on selecting sample trees, weighing tree components in the field, excavating root systems and obtaining fresh weights and laboratory analyses of components to determine oven dry weights. The development of these sampling procedures is a basic step towards successful, consistent collection of biomass data in 18-20 years old plantation forests. This methodology was developed for eucalypt hardwood timber plantations in Queensland, Australia. However, these procedures can be applied to plantations elsewhere as well as to trees in native forest environments with minor modifications. The methodology developed for field sampling of the tree components and the derivation of allometric relationships for predicting individual tree biomass (above and belowground) highlighted the following:•Accurate quantification of above and belowground biomass of eucalypts.•Description of measured variables for developing allometric relationships.•Integration of field and laboratory measurements to streamline data collection

    A clinical and economic evaluation of Control of Hyperglycaemia in Paediatric intensive care (CHiP): a randomised controlled trial.

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    BACKGROUND: Early research in adults admitted to intensive care suggested that tight control of blood glucose during acute illness can be associated with reductions in mortality, length of hospital stay and complications such as infection and renal failure. Prior to our study, it was unclear whether or not children could also benefit from tight control of blood glucose during critical illness. OBJECTIVES: This study aimed to determine if controlling blood glucose using insulin in paediatric intensive care units (PICUs) reduces mortality and morbidity and is cost-effective, whether or not admission follows cardiac surgery. DESIGN: Randomised open two-arm parallel group superiority design with central randomisation with minimisation. Analysis was on an intention-to-treat basis. Following random allocation, care givers and outcome assessors were no longer blind to allocation. SETTING: The setting was 13 English PICUs. PARTICIPANTS: Patients who met the following criteria were eligible for inclusion: ≥ 36 weeks corrected gestational age; ≤ 16 years; in the PICU following injury, following major surgery or with critical illness; anticipated treatment > 12 hours; arterial line; mechanical ventilation; and vasoactive drugs. Exclusion criteria were as follows: diabetes mellitus; inborn error of metabolism; treatment withdrawal considered; in the PICU > 5 consecutive days; and already in CHiP (Control of Hyperglycaemia in Paediatric intensive care). INTERVENTION: The intervention was tight glycaemic control (TGC): insulin by intravenous infusion titrated to maintain blood glucose between 4.0 and 7.0 mmol/l. CONVENTIONAL MANAGEMENT (CM): This consisted of insulin by intravenous infusion only if blood glucose exceeded 12.0 mmol/l on two samples at least 30 minutes apart; insulin was stopped when blood glucose fell below 10.0 mmol/l. MAIN OUTCOME MEASURES: The primary outcome was the number of days alive and free from mechanical ventilation within 30 days of trial entry (VFD-30). The secondary outcomes comprised clinical and economic outcomes at 30 days and 12 months and lifetime cost-effectiveness, which included costs per quality-adjusted life-year. RESULTS: CHiP recruited from May 2008 to September 2011. In total, 19,924 children were screened and 1369 eligible patients were randomised (TGC, 694; CM, 675), 60% of whom were in the cardiac surgery stratum. The randomised groups were comparable at trial entry. More children in the TGC than in the CM arm received insulin (66% vs. 16%). The mean VFD-30 was 23 [mean difference 0.36; 95% confidence interval (CI) -0.42 to 1.14]. The effect did not differ among prespecified subgroups. Hypoglycaemia occurred significantly more often in the TGC than in the CM arm (moderate, 12.5% vs. 3.1%; severe, 7.3% vs. 1.5%). Mean 30-day costs were similar between arms, but mean 12-month costs were lower in the TGC than in CM arm (incremental costs -£3620, 95% CI -£7743 to £502). For the non-cardiac surgery stratum, mean costs were lower in the TGC than in the CM arm (incremental cost -£9865, 95% CI -£18,558 to -£1172), but, in the cardiac surgery stratum, the costs were similar between the arms (incremental cost £133, 95% CI -£3568 to £3833). Lifetime incremental net benefits were positive overall (£3346, 95% CI -£11,203 to £17,894), but close to zero for the cardiac surgery stratum (-£919, 95% CI -£16,661 to £14,823). For the non-cardiac surgery stratum, the incremental net benefits were high (£11,322, 95% CI -£15,791 to £38,615). The probability that TGC is cost-effective is relatively high for the non-cardiac surgery stratum, but, for the cardiac surgery subgroup, the probability that TGC is cost-effective is around 0.5. Sensitivity analyses showed that the results were robust to a range of alternative assumptions. CONCLUSIONS: CHiP found no differences in the clinical or cost-effectiveness of TGC compared with CM overall, or for prespecified subgroups. A higher proportion of the TGC arm had hypoglycaemia. This study did not provide any evidence to suggest that PICUs should stop providing CM for children admitted to PICUs following cardiac surgery. For the subgroup not admitted for cardiac surgery, TGC reduced average costs at 12 months and is likely to be cost-effective. Further research is required to refine the TGC protocol to minimise the risk of hypoglycaemic episodes and assess the long-term health benefits of TGC. TRIAL REGISTRATION: Current Controlled Trials ISRCTN61735247. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 26. See the NIHR Journals Library website for further project information

    Dissection of quantitative blackleg resistance reveals novel variants of resistance gene Rlm9 in elite Brassica napus

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    Blackleg is one of the major fungal diseases in oilseed rape/canola worldwide. Most commercial cultivars carry R gene-mediated qualitative resistances that confer a high level of race-specific protection against Leptosphaeria maculans, the causal fungus of blackleg disease. However, monogenic resistances of this kind can potentially be rapidly overcome by mutations in the pathogen’s avirulence genes. To counteract pathogen adaptation in this evolutionary arms race, there is a tremendous demand for quantitative background resistance to enhance durability and efficacy of blackleg resistance in oilseed rape. In this study, we characterized genomic regions contributing to quantitative L. maculans resistance by genome-wide association studies in a multiparental mapping population derived from six parental elite varieties exhibiting quantitative resistance, which were all crossed to one common susceptible parental elite variety. Resistance was screened using a fungal isolate with no corresponding avirulence (AvrLm) to major R genes present in the parents of the mapping population. Genome-wide association studies revealed eight significantly associated quantitative trait loci (QTL) on chromosomes A07 and A09, with small effects explaining 3–6% of the phenotypic variance. Unexpectedly, the qualitative blackleg resistance gene Rlm9 was found to be located within a resistance-associated haploblock on chromosome A07. Furthermore, long-range sequence data spanning this haploblock revealed high levels of singlenucleotide and structural variants within the Rlm9 coding sequence among the parents of the mapping population. The results suggest that novel variants of Rlm9 could play a previously unknown role in expression of quantitative disease resistance in oilseed rape

    Building Babies - Chapter 16

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    In contrast to birds, male mammals rarely help to raise the offspring. Of all mammals, only among rodents, carnivores, and primates, males are sometimes intensively engaged in providing infant care (Kleiman and Malcolm 1981). Male caretaking of infants has long been recognized in nonhuman primates (Itani 1959). Given that infant care behavior can have a positive effect on the infant’s development, growth, well-being, or survival, why are male mammals not more frequently involved in “building babies”? We begin the chapter defining a few relevant terms and introducing the theory and hypotheses that have historically addressed the evolution of paternal care. We then review empirical findings on male care among primate taxa, before focusing, in the final section, on our own work on paternal care in South American owl monkeys (Aotus spp.). We conclude the chapter with some suggestions for future studies.Deutsche Forschungsgemeinschaft (HU 1746/2-1) Wenner-Gren Foundation, the L.S.B. Leakey Foundation, the National Geographic Society, the National Science Foundation (BCS-0621020), the University of Pennsylvania Research Foundation, the Zoological Society of San Dieg
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