A hybrid multilevel converter for medium and high voltage applications

This paper investigates the suitability of the hybrid multilevel converter for medium and high voltage application. The converter operation, modulation, and capacitor voltage balancing method are described in detail. The ability of the hybrid multilevel converter to operate with different modulation indices and load power factors is investigated. It has been established that the hybrid multilevel converter is capable of operating independent of load power factor. Operation with variable modulation index increases voltage stresses on the converter switches and does not alter the fundamental voltage magnitude as in all known voltage source converter topologies. The viability of the hybrid multilevel converter for medium and high voltage applications is confirmed by simulations

Thrombolysis in very elderly people: controlled comparison of SITS international stroke thrombolysis registry and virtual international stroke trials archive

<p>Objective To assess effect of age on response to alteplase in acute ischaemic stroke.</p> <p>Design Adjusted controlled comparison of outcomes between non-randomised patients who did or did not undergo thrombolysis. Analysis used Cochran-Mantel-Haenszel test and proportional odds logistic regression analysis.</p> <p>Setting Collaboration between International Stroke Thrombolysis Registry (SITS-ISTR) and Virtual International Stroke Trials Archive (VISTA).</p> <p>Participants 23 334 patients from SITS-ISTR (December 2002 to November 2009) who underwent thrombolysis and 6166 from VISTA neuroprotection trials (1998-2007) who did not undergo thrombolysis (as controls). Of the 29 500 patients (3472 aged >80 (“elderly,” mean 84.6), data on 272 patients were missing for baseline National Institutes of Health stroke severity score, leaving 29 228 patients for analysis adjusted for age and baseline severity.</p> <p>Main outcome measures Functional outcomes at 90 days measured by score on modified Rankin scale.</p> <p>Results Median severity at baseline was the same for patients who underwent thrombolysis and controls (median baseline stroke scale score: 12 for each group, P=0.14; n=29 228). The distribution of scores on the modified Rankin scale was better among all thrombolysis patients than controls (odds ratio 1.6, 95% confidence interval 1.5 to 1.7; Cochran-Mantel-Haenszel P<0.001). The association occurred independently among patients aged ≤80 (1.6, 1.5 to 1.7; P<0.001; n=25 789) and in those aged >80 (1.4, 1.3 to 1.6; P0.001; n=3439). Odds ratios were consistent across all 10 year age ranges above 30, and benefit was significant from age 41 to 90; dichotomised outcomes (score on modified Rankin scale 0-1 v 2-6; 0-2 v 3-6; and 6 (death) v rest) were consistent with the results of the ordinal analysis.</p> <p>Conclusions Outcome in patients with acute ischaemic stroke is significantly better in those who undergo thrombolysis compared with those who do not. Increasing age is associated with poorer outcome but the association between thrombolysis treatment and improved outcome is maintained in very elderly people. Age alone should not be a barrier to treatment.</p&gt

Some Applications of the Gold Activation by Environmental Neutrons

金沢大学自然計測応用研究センター自然計測研究部門金沢大学環日本海域環境研究センターThe activation of gold by environmental neutrons was used to study the effect of concrete buildings at our laboratory (LLRL) on the neutron flux, and to estimate the thermal neutron flux in and around the building of Kinki University Training Reactor (UTR-Kinki). The results showed that three ceilings of thickness (34 g/cm2 each) decrease the fast neutrons to 26 %. However, the same reinforced concrete decreases the slow flux to only 62 %. On the other hand, the thermal neutron flux at 283m from the reactor center was two times higher than the environmental background. These results can give attention to the effect of concrete walls as a shielding around the reactors, especially those that have been hold near to the living environments

Variation of environmental neutron flux with the depth of water and soil

金沢大学環日本海域環境研究センター金沢大学自然計測応用研究センター自然計測研究部門As a part of interest in the study of the neutron flux in biological environments, variations of slow neutrons with depth of water and soil were measured through the radioactivity induced in gold by 197Au(n,γ)198Au interaction. The measurements made for 0-100 cm in fresh water and 20-400 cm in sea water showed that the thermal neutron flux showed peak at around 10 cm depth and then gradually decreased with depth in water. The depth profiles in seawater were almost the same profile as freshwater. In the case of soil made for 0-60 cm, thermal neutron flux showed a peak at 5 cm then through a shoulder-like decrease during 10~30 cm range and decreased with depth gradually rapidly to 60 cm

Constraining R-parity violating couplings using dimuon data at Tevatron Run-II

The dimuon plus dijet signal is analyzed in the top squark pair production at Tevatron Run-II experiment and the total event rate is compared with the existing dimuon data. This comparison rules out top squark mass upto 188(104) GeV for the branching fraction 100%(50%) of top squark decay into the muon plus quark via lepton number violating coupling. Interpretation of this limit in the framework of R-parity violating(RPV) SUSY model puts limit on relevant RPV coupling for a given top squark mass and other supersymmetric model parameters. If \MST \lsim 180 GeV we found that the RPV couplings are roughly restricted to be within $\sim 10^{-4}$ which is at the same ballpark value obtained from the neutrino data. The limits are very stringent for a scenario where top squarks appear to be the next lightest supersymmetric particles.Comment: 7 pages, 3 figures,added minor clarifications,version to appear in Phys. Lett.

The effect of selected commercially available mouth-rinses vs. curcumin photosensitizers in an artificial mouth model mimicking their use before meals on early colonizers single species biofilm

Abstract. – OBJECTIVE: The aim of the study was to determine the bacterial-adherence to the experimental pellicle pretreated with commer- cially available oral-rinse/photosensitizer (mim- icking use of oral-rinse/photosensitizer beforemeals). MATERIALS AND METHODS: An artificial mouth (NAM) system was used for the devel- opment of single-species biofilm (Actinomyces viscosus, Sreptococcus mitis and Streptococ- cus sanguinis respectively). Two commercially available oral-rinses containing active ingredi- ents [Essential oils (EO) and Chlorhexidine glu-conate (CHX) were used. Curcumin photosensi-tizer (PS) was used as a photosensitizer against the microbes. For the adherence study, the ex-perimental pellicle on the beads (in the capillary tubes of the NAM system) was pretreated with the oral-rinse and photosensitizer before the in-oculation of bacteria; this would resemble the use of rinse/photosensitizer before meal. The bacterial population of the biofilm was determined using serial dilution assay and expressed as colony forming unit per ml. Deionized distilled water was used in place of oral-rinse/ photosensitizer and served as a negative-control. For the qualitative study, bacterial population viewing was carried out using Scanning Electron Microscope (SEM). RESULTS: It was observed that on treatment with the oral-rinses the bacterial population of S.mitis, S.sanguinis and A.viscosus (adherence) was significantly reduced where the reduction was less for EO-based oral-rinse compared with that of CHX and curcumin PS in the following se- quence EO<CHX<PS (p<0.05). CONCLUSIONS: From the results, it appears that curcumin photosensitizer and oral-rinses contain CHX to be preferably used before-meal and EO after-meal

Measurement of the beam-helicity asymmetry in photoproduction of π0η pairs on carbon, aluminum, and lead

The beam-helicity asymmetry was measured, for the first time, in photoproduction of π0η pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for π0η pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the D33 partial wave with the ηΔ(1232) intermediate state

Feijão guandu cru na alimentação de frangos caipiras criados em sistema semi-intensivo

O objetivo deste trabalho foi avaliar os efeitos da substituição do farelo de soja pelo feijão guandu cru na alimentação de frangos caipiras criados em sistema semi-intensivo. Foram utilizados 525 frangos de corte da linhagem Caipira Pesadão, com idade inicial de 35 dias, distribuídos em cinco tratamentos com cinco repetições de 21 aves cada um. Os tratamentos consistiram na substituição de 0, 5, 10, 15 e 20% do farelo de soja pelo feijão guandu cru moído. Foram avaliados o ganho de peso, o consumo de ração, a conversão alimentar, o rendimento de carcaça e de cortes, o peso do pâncreas e a qualidade da carne. A substituição do farelo de soja pelo feijão guandu em até 15,45%, nas dietas de frangos caipiras de corte, com idade de 57 a 71 dias, não altera o ganho de peso. O aumento dos níveis de feijão guandu na ração não afeta o rendimento de carcaça, o peso do pâncreas e os parâmetros de qualidade da carne

Helicity of the W Boson in Lepton+Jets ttbar Events

We examine properties of ttbar candidates events in lepton+jets final states to establish the helicities of the W bosons in t->W+b decays. Our analysis is based on a direct calculation of a probability that each event corresponds to a ttbar final state, as a function of the helicity of the W boson. We use the 125 events/pb sample of data collected by the DO experiment during Run I of the Fermilab Tevatron collider at sqrt{s}=1.8 TeV, and obtain a longitudinal helicity fraction of F_0=0.56+/-0.31, which is consistent with the prediction of F_0=0.70 from the standard model

Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

BackgroundHuman immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.MethodsWe performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.ResultsAll countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries-apart from Ecuador-across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups-the median age group among decedents ranged from 30 to 45years of age at the municipality level in Brazil, Colombia, and Mexico in 2017.ConclusionsOur subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.Peer reviewe