696 research outputs found

    Design of a microwave radiometer for monitoring high voltage insulator contamination level

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    Microwave radiometry is a novel method for monitoring contamination levels on high voltage insulators. The microwave radiometer described measures energy emitted from the contamination layer and could provide a safe, reliable, contactless monitoring method that is effective under dry conditions. The design of the system has focused on optimizing accuracy, stability and sensitivity using a relatively low cost architecture. Experimental results demonstrate that the output from the radiometer is able to clearly distinguish between samples with different contamination levels under dry conditions. This contamination monitoring method could potentially provide advance warning of the future failure of wet insulators in climates where insulators can experience dry conditions for extended periods

    Mapping the sensitivity of split ring resonators using a localized analyte

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    Split ring resonator (SRR) based metamaterials have frequently been demonstrated for use as optical sensors of organic materials. This is made possible by matching the wavelength of the SRR plasmonic resonance with a molecular resonance of a specific analyte, which is usually placed on top of the metal structure. However, systematic studies of SRRs that identify the regions that exhibit a high electric field strength are commonly performed using simulations. In this paper we demonstrate that areas of high electric field strength, termed “hot-spots,” can be found by localizing a small quantity of organic analyte at various positions on or near the structure. Furthermore, the sensitivity of the SRR to the localized analyte can be quantified to determine, experimentally, suitable regions for optical sensing

    Unbalanced chemical equations conversion to Mark-up format and representation to vision impaired students

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    This paper describes a method to represent unbalanced chemical equations to vision impaired students which allows them to navigate through classified data, such as species, elements, quantity numbers at the left and right hand sides of equations, reactants, and products. Then they can find appropriate coefficients and balance chemical equations without involving to mathematical aspects of balancing and remembering a lot of information. The goal of this research was the development of an application which assists vision impaired students enrolled in chemistry course to be able to read chemistry literature containing formulae, chemistry representations of elements, and other aspects of chemistry that has been difficult in the past to present in a way for vision impaired people to understand. Developed application by this research is an open source command line Bash Script application under Linux which accepts an unbalanced chemical equation as an input, processes, classifies information, and represents it as Mark-up format or Alternative Audio Descriptive using Text to Speech

    A density of ramified primes

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    Let KK be a cyclic totally real number field of odd degree over Q\mathbb{Q} with odd class number, such that every totally positive unit is the square of a unit, and such that 22 is inert in K/QK/\mathbb{Q}. We define a family of number fields {K(p)}p\{K(p)\}_p, depending on KK and indexed by the rational primes pp that split completely in K/QK/\mathbb{Q}, such that pp is always ramified in K(p)K(p) of degree 22. Conditional on a standard conjecture on short character sums, the density of such rational primes pp that exhibit one of two possible ramified factorizations in K(p)/QK(p)/\mathbb{Q} is strictly between 00 and 11 and is given explicitly as a formula in terms of [K:Q][K:\mathbb{Q}]. Our results are unconditional in the cubic case. Our proof relies on a detailed study of the joint distribution of spins of prime ideals

    An observational study of patient characteristics associated with the mode of admission to acute stroke services in North East, England

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    Objective Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services. Study design and setting A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases. Results Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis. Conclusion Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations
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