29 research outputs found

    Scaling of a Fast Fourier Transform and a pseudo-spectral fluid solver up to 196608 cores

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    In this paper we present scaling results of a FFT library, FFTK, and a pseudospectral code, Tarang, on grid resolutions up to 819238192^3 grid using 65536 cores of Blue Gene/P and 196608 cores of Cray XC40 supercomputers. We observe that communication dominates computation, more so on the Cray XC40. The computation time scales as Tcomp∼p−1T_\mathrm{comp} \sim p^{-1}, and the communication time as Tcomm∼n−γ2T_\mathrm{comm} \sim n^{-\gamma_2} with γ2\gamma_2 ranging from 0.7 to 0.9 for Blue Gene/P, and from 0.43 to 0.73 for Cray XC40. FFTK, and the fluid and convection solvers of Tarang exhibit weak as well as strong scaling nearly up to 196608 cores of Cray XC40. We perform a comparative study of the performance on the Blue Gene/P and Cray XC40 clusters

    First Results from the AMoRE-Pilot neutrinoless double beta decay experiment

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    The Advanced Molybdenum-based Rare process Experiment (AMoRE) aims to search for neutrinoless double beta decay (0νββ\nu\beta\beta) of 100^{100}Mo with ∼\sim100 kg of 100^{100}Mo-enriched molybdenum embedded in cryogenic detectors with a dual heat and light readout. At the current, pilot stage of the AMoRE project we employ six calcium molybdate crystals with a total mass of 1.9 kg, produced from 48^{48}Ca-depleted calcium and 100^{100}Mo-enriched molybdenum (48depl^{48\textrm{depl}}Ca100^{100}MoO4_4). The simultaneous detection of heat(phonon) and scintillation (photon) signals is realized with high resolution metallic magnetic calorimeter sensors that operate at milli-Kelvin temperatures. This stage of the project is carried out in the Yangyang underground laboratory at a depth of 700 m. We report first results from the AMoRE-Pilot 0νββ0\nu\beta\beta search with a 111 kg⋅\cdotd live exposure of 48depl^{48\textrm{depl}}Ca100^{100}MoO4_4 crystals. No evidence for 0νββ0\nu\beta\beta decay of 100^{100}Mo is found, and a upper limit is set for the half-life of 0νββ\nu\beta\beta of 100^{100}Mo of T1/20ν>9.5×1022T^{0\nu}_{1/2} > 9.5\times10^{22} y at 90% C.L.. This limit corresponds to an effective Majorana neutrino mass limit in the range ⟨mββ⟩≤(1.2−2.1)\langle m_{\beta\beta}\rangle\le(1.2-2.1) eV

    Surgical management of Diabetic foot ulcers: A Tanzanian university teaching hospital experience

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    \ud \ud Diabetic foot ulcers (DFUs) pose a therapeutic challenge to surgeons, especially in developing countries where health care resources are limited and the vast majority of patients present to health facilities late with advanced foot ulcers. A prospective descriptive study was done at Bugando Medical Centre from February 2008 to January 2010 to describe our experience in the surgical management of DFUs in our local environment and compare with what is known in the literature. Of the total 4238 diabetic patients seen at BMC during the period under study, 136 (3.2%) patients had DFUs. Males outnumbered females by the ratio of 1.2:1. Their mean age was 54.32 years (ranged 21-72years). Thirty-eight (27.9%) patients were newly diagnosed diabetic patients. The majority of patients (95.5%) had type 2 diabetes mellitus. The mean duration of diabetes was 8.2 years while the duration of DFUs was 18.34 weeks. Fourteen (10.3%) patients had previous history of foot ulcers and six (4.4%) patients had previous amputations. The forefoot was commonly affected in 60.3% of cases. Neuropathic ulcers were the most common type of DFUs in 57.4% of cases. Wagner's stage 4 and 5 ulcers were the most prevalent at 29.4% and 23.5% respectively. The majority of patients (72.1%) were treated surgically. Lower limb amputation was the most common surgical procedure performed in 56.7% of cases. The complication rate was (33.5%) and surgical site infection was the most common complication (18.8%). Bacterial profile revealed polymicrobial pattern and Staphylococcus aureus was the most frequent microorganism isolated. All the microorganisms isolated showed high resistance to commonly used antibiotics except for Meropenem and imipenem, which were 100% sensitive each respectively. The mean hospital stay was 36.24 ± 12.62 days (ranged 18-128 days). Mortality rate was 13.2%. Diabetic foot ulceration constitutes a major source of morbidity and mortality among patients with diabetes mellitus at Bugando Medical Centre and is the leading cause of non-traumatic lower limb amputation. A multidisciplinary team approach targeting at good glycaemic control, education on foot care and appropriate footware, control of infection and early surgical intervention is required in order to reduce the morbidity and mortality associated with DFUs. Due to polymicrobial infection and antibiotic resistance, surgical intervention must be concerned

    Lead-borate glass system doped with Sm3+ ions for the X-ray shielding applications

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    The impact of varying Sm2O3 content on radiation shielding properties of 15PbF2: (65-x) B2O3: 20K2O:xSm2O3 (where 0 ≤ x ≤ 1.5 mol %) glass samples, was investigated by studying their physical, radio-luminescence and X-ray-shielding characteristics. The density of glasses increased with an increase in Sm2O3 contents. Evaluating the X-ray shielding parameters like mass and linear attenuation coefficients, half- and tenth- value layer, lead equivalent thickness and mean free path, it was found that the linear and mass attenuation coefficients decrease with a rise in Sm3+ concentration in the 70–120-kVp-energy range. The half- and tenth-value layers of the developed glasses increase with increasing energy and vary randomly with changing Sm2O3 contents. Comparing the determined HVL data with that of the concrete, red brick, commercial window, and X-ray window at 120 keV, it is found that the developed glass performs better shielding. The obtained results revealed that this glass has excellent potential and could be used as a radiation-shielding material in various applications
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