309 research outputs found

    Electromagnetic Radiation Hardness of Diamond Detectors

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    The behavior of artificially grown CVD diamond films under intense electromagnetic radiation has been studied. The properties of irradiated diamond samples have been investigated using the method of thermally stimulated current and by studying their charge collection properties. Diamonds have been found to remain unaffected after doses of 6.8 MGy of 10 keV photons and 10 MGy of MeV-range photons. This observation makes diamond an attractive detector material for a calorimeter in the very forward region of the proposed TESLA detector.Comment: 19 pages, 9 figure

    TL and OSL response of turquoise for dosimetric application

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    Turquoise is one of the amongst first gem stones used in jewelry and possessing cultural value since 2000 BC (at least). This work attempts characterize this stone scientifically using both thermally (TL) and optically stimulated luminescence (OSL) techniques. The experimental investigation included 1) the study of the natural TL and OSL signals, 2) the reproducibility of TL sensitivity over repeated irradiation and TL readout cycles, 3) dependence of sensitivity on annealing temperatures and 4) the TL and OSL dose response curves. The potential use of the TL and OSL techniques in determination of provenance, accidental dosimetry and probably to authenticity and dating purposes are then discussed.Publisher's Versio

    Monitoring of drinking water distribution system by SCADA in Antalya City, Turkey

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    Antalya water and wastewater administration has recently completed SCADA (Supervisory Control And Data Acquisition) system. The system enabled the on-line continuous monitoring of many water quantity and quality parameters such as flow rate, pressure, temperature, pH, turbidity, electrical conductivity, and free residual chlorine. Additionally, water levels in the distribution reservoirs, water pumps, energy consumption and the closing valves are monitored and controlled by the SCADA system. Beside the on-line continuous monitoring, field sampling and lab analyses of other water quality parameters such as total organic carbon, THM, bromide, iron, nitrogen and phosphorous groups, and coliform bacteria were conducted. The results of field sampling agreed with the on-line monitoring values. The SCADA system proved to be very useful for reducing water losses, improving water quality, reducing energy consumption and improving the reliability of the system

    Optimizing tuning masses for helicopter rotor blade vibration reduction including computed airloads and comparison with test data

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    The development and validation of an optimization procedure to systematically place tuning masses along a rotor blade span to minimize vibratory loads are described. The masses and their corresponding locations are the design variables that are manipulated to reduce the harmonics of hub shear for a four-bladed rotor system without adding a large mass penalty. The procedure incorporates a comprehensive helicopter analysis to calculate the airloads. Predicting changes in airloads due to changes in design variables is an important feature of this research. The procedure was applied to a one-sixth, Mach-scaled rotor blade model to place three masses and then again to place six masses. In both cases the added mass was able to achieve significant reductions in the hub shear. In addition, the procedure was applied to place a single mass of fixed value on a blade model to reduce the hub shear for three flight conditions. The analytical results were compared to experimental data from a wind tunnel test performed in the Langley Transonic Dynamics Tunnel. The correlation of the mass location was good and the trend of the mass location with respect to flight speed was predicted fairly well. However, it was noted that the analysis was not entirely successful at predicting the absolute magnitudes of the fixed system loads

    Thermoluminescence Properties of Novel Self-Agglomerating CaSO 4

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    In this work, we report the thermoluminescence (TL) properties of self-agglomerating CaSO4:Eu samples obtained by an environmentally friendly coprecipitation technique. No binding material is needed to form solid CaSO4:Eu samples. Samples exposed to beta particle irradiation exhibit a TL maximum at 473.15 K when a 5 K/s heating rate is used, they are two times more sensitive than the TLD-100 commercial dosimeter, and their lower detection limit was determined to be less than 0.69 mGy. The computerized glow curve deconvolution carried out fitting the residual glow curves from McKeever method revealed that the whole glow curve is composed of four individual TL peaks with intermediate-order kinetics. The main peak order kinetics is b = 1.48. This result agrees with that computed using Chen’s formula

    Prevalence of inflammatory bowel disease among coeliac disease patients in a Hungarian coeliac centre

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    BACKGROUND: Celiac disease, Crohn disease and ulcerative colitis are inflammatory disorders of the gastrointestinal tract with some common genetic, immunological and environmental factors involved in their pathogenesis. Several research shown that patients with celiac disease have increased risk of developing inflammatory bowel disease when compared with that of the general population. The aim of this study is to determine the prevalence of inflammatory bowel disease in our celiac patient cohort over a 15-year-long study period. METHODS: To diagnose celiac disease, serological tests were used, and duodenal biopsy samples were taken to determine the degree of mucosal injury. To set up the diagnosis of inflammatory bowel disease, clinical parameters, imaging techniques, colonoscopy histology were applied. DEXA for measuring bone mineral density was performed on every patient. RESULTS: In our material, 8/245 (3,2 %) coeliac disease patients presented inflammatory bowel disease (four males, mean age 37, range 22-67), 6/8 Crohn's disease, and 2/8 ulcerative colitis. In 7/8 patients the diagnosis of coeliac disease was made first and inflammatory bowel disease was identified during follow-up. The average time period during the set-up of the two diagnosis was 10,7 years. Coeliac disease serology was positive in all cases. The distribution of histology results according to Marsh classification: 1/8 M1, 2/8 M2, 3/8 M3a, 2/8 M3b. The distribution according to the Montreal classification: 4/6 Crohn's disease patients are B1, 2/6 Crohn's disease patients are B2, 2/2 ulcerative colitis patients are S2. Normal bone mineral density was detected in 2/8 case, osteopenia in 4/8 and osteoporosis in 2/8 patients. CONCLUSIONS: Within our cohort of patients with coeliac disease, inflammatory bowel disease was significantly more common (3,2 %) than in the general population

    The clinical utility of pain classification in non-specific arm pain

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    Mechanisms-based pain classification has received considerable attention recently for its potential use in clinical decision making. A number of algorithms for pain classification have been proposed. Non-specific arm pain (NSAP) is a poorly defined condition, which could benefit from classification according to pain mechanisms to improve treatment selection. This study used three published classification algorithms (hereafter called NeuPSIG, Smart, Schafer) to investigate the frequency of different pain classifications in NSAP and the clinical utility of these systems in assessing NSAP. Forty people with NSAP underwent a clinical examination and quantitative sensory testing. Findings were used to classify participants according to three classification algorithms. Frequency of pain classification including number unclassified was analysed using descriptive statistics. Inter-rater agreement was analysed using kappa coefficients. NSAP was primarily classified as ‘unlikely neuropathic pain’ using NeuPSIG criteria, ‘peripheral neuropathic pain’ using the Smart classification and ‘peripheral nerve sensitisation’ using the Schafer algorithm. Two of the three algorithms allowed classification of all but one participant; up to 45% of participants (n = 18) were categorised as mixed by the Smart classification. Inter-rater agreement was good for the Schafer algorithm (к = 0.78) and moderate for the Smart classification (к = 0.40). A kappa value was unattainable for the NeuPSIG algorithm but agreement was high. Pain classification was achievable with high inter-rater agreement for two of the three algorithms assessed. The Smart classification may be useful but requires further direction regarding the use of clinical criteria included. The impact of adding a pain classification to clinical assessment on patient outcomes needs to be evaluated

    Muscle damage response in female collegiate athletes following repeated sprint activity

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    Exercise induced muscle damage (EIMD) is a well-investigated area, however there is a paucity of data surrounding the damage response in females. The aim of this study was to examine the damage responses from a sport-specific bout of repeated sprints in female athletes. Eleven well-trained females (mean ± SD; age 22 ± 3 y, height 166.6 ± 5.7 cm, mass 62.7 ± 4.5 kg) in the luteal phase of the menstrual cycle completed a repeated sprint protocol designed to induce EIMD (15 × 30 m sprints). Creatine kinase (CK), countermovement jump height (CMJ), knee extensor maximum voluntary contraction force (MVIC), muscle soreness (DOMS), 30 m sprint time and limb girth were recorded pre, post, 24 h, 48 h and 72 h post exercise. CK was elevated at 24, 48 and 72 h (p < 0.05), peaking at 24 h (+418%) and returning towards baseline at 72 h. CMJ height was reduced immediately post, 24 and 48 h (p < 0.05). Sprint performance was also negatively affected immediately post, 24 h, 48 h and 72 h post exercise. Muscle soreness peaked at 48 h (p<0.01) and remained significantly elevated at 72 h post exercise (p<0.01). Limb girth and MVIC did not alter over time. The current study provides new information on the EIMD response in trained females following a sport specific bout of repeated sprints. Importantly, this damage response has the potential to negatively affect performance for several days post-exercise
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