280 research outputs found

    Fabrication and Results of the First MgB2 Round Coil Superferric Magnet at LASA

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    The LASA Laboratory (INFN, Milan) is working in the High Luminosity LHC program to develop, in collaboration with CERN, six different types of High Order corrector magnets. In this framework, in parallel with a conventional design of superferric magnets with LTS conductor, the LASA is focusing on the research of new superconducting materials which may have applications in particle accelerator magnets. To this purpose, LASA is developing a new type of superferric magnet suitable to arbitrary multipole order, called Round Coil Superferric Magnets (RCSM). The iron yoke shaped with an arbitrary number of poles is able to create the desired harmonic component using only one single round coil with a large bending radius suitable for very strain-sensitive superconductors. The electromagnetic design of a sextupole configuration of the magnet and the production of the first superconducting MgB2 round coil prototype have been already presented. In this paper, we expose the optimization of the iron yoke and polar expansions assembly of the first magnet semi-module prototype. The results of the whole powering test are described in detail and the analysis of the magnetic performances are compared with those of classical superferric correctors

    Efeitos da poluição do ar nas doenças cardiovasculares: estruturas de defasagem

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    OBJETIVO: Investigar a estrutura de defasagem entre exposição à poluição do ar e internações hospitalares por doenças cardiovasculares em idosos, separada por gênero. MÉTODOS: Os dados de saúde de pessoas com mais de 64 anos de idade foram estratificados por gênero, na cidade de São Paulo, entre 1996 e 2001. Os níveis diários de poluentes do ar (CO, PM10, O3, NO2, SO2) e os dados de temperatura mínima e umidade relativa do ar foram também foram analisados. Foram utilizados modelos restritos de distribuição polinomial em modelos aditivos generalizados de regressão de Poisson para estimar os efeitos dos poluentes no dia da exposição e até 20 dias após, controlando-se para sazonalidades de longa e curta durações, feriados e fatores meteorológicos. RESULTADOS: Variações interquartis de PM10 (26,21 mig/m³) e SO2 (10,73 mig/m³) foram associados com aumentos de 3,17% (IC 95%: 2,09-4,25) nas admissões por insuficiência cardíaca congestiva e de 0,89% (IC 95%: 0,18-1,61) para admissões por todas as doenças cardiovasculares no dia da exposição, respectivamente. Os efeitos foram predominantemente agudos e maiores para o gênero feminino. Além disso, foi observado efeito colheita. CONCLUSÕES: Os achados mostraram que as doenças cardiovasculares em São Paulo são fortemente afetadas pela poluição do ar.OBJECTIVE: To assess the lag structure between air pollution exposure and elderly cardiovascular diseases hospital admissions, by gender. METHODS: Health data of people aged 64 years or older was stratified by gender in São Paulo city, Southeastern Brazil, from 1996 to 2001. Daily levels of air pollutants (CO, PM10, O3, NO2, and SO2) , minimum temperature, and relative humidity were also analyzed. It were fitted generalized additive Poisson regressions and used constrained distributed lag models adjusted for long time trend, weekdays, weather and holidays to assess the lagged effects of air pollutants on hospital admissions up to 20 days after exposure. RESULTS: Interquartile range increases in PM10 (26.21 mug/m³) and SO2 (10.73 mug/m³) were associated with 3.17% (95% CI: 2.09-4.25) increase in congestive heart failure and 0.89% (95% CI: 0.18-1.61) increase in total cardiovascular diseases at lag 0, respectively. Effects were higher among female group for most of the analyzed outcomes. Effects of air pollutants for different outcomes and gender groups were predominately acute and some "harvesting" were found. CONLUSIONS: The results show that cardiovascular diseases in São Paulo are strongly affected by air pollution

    Giant and tunable anisotropy of nanoscale friction in graphene

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISThe nanoscale friction between an atomic force microscopy tip and graphene is investigated using friction force microscopy (FFM). During the tip movement, friction forces are observed to increase and then saturate in a highly anisotropic manner. As a result, the friction forces in graphene are highly dependent on the scanning direction: under some conditions, the energy dissipated along the armchair direction can be 80% higher than along the zigzag direction. In comparison, for highly-oriented pyrolitic graphite (HOPG), the friction anisotropy between armchair and zigzag directions is only 15%. This giant friction anisotropy in graphene results from anisotropies in the amplitudes of flexural deformations of the graphene sheet driven by the tip movement, not present in HOPG. The effect can be seen as a novel manifestation of the classical phenomenon of Euler buckling at the nanoscale, which provides the non-linear ingredients that amplify friction anisotropy. Simulations based on a novel version of the 2D Tomlinson model (modified to include the effects of flexural deformations), as well as fully atomistic molecular dynamics simulations and first-principles density-functional theory (DFT) calculations, are able to reproduce and explain the experimental observations.The nanoscale friction between an atomic force microscopy tip and graphene is investigated using friction force microscopy (FFM). During the tip movement, friction forces are observed to increase and then saturate in a highly anisotropic manner. As a result, the friction forces in graphene are highly dependent on the scanning direction: under some conditions, the energy dissipated along the armchair direction can be 80% higher than along the zigzag direction. In comparison, for highly-oriented pyrolitic graphite (HOPG), the friction anisotropy between armchair and zigzag directions is only 15%. This giant friction anisotropy in graphene results from anisotropies in the amplitudes of flexural deformations of the graphene sheet driven by the tip movement, not present in HOPG. The effect can be seen as a novel manifestation of the classical phenomenon of Euler buckling at the nanoscale, which provides the non-linear ingredients that amplify friction anisotropy. Simulations based on a novel version of the 2D Tomlinson model (modified to include the effects of flexural deformations), as well as fully atomistic molecular dynamics simulations and first-principles density-functional theory (DFT) calculations, are able to reproduce and explain the experimental observations.619CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPERJ - FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIROFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAISSem informaçãoSem informação2013/08293-7, 2014/15521-9Sem informaçãoAll authors aknowledge the financial support from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ). R.P. acknowledges Fundação de Amparo a Pesquisa do Estado de São Paulo (Fapesp) for financial support through Grant #2014/15521-9. D.S.G. thanks the Center for Computational Engineering and Sciences at Unicamp for financial support through the FAPESP/CEPID Grant # 2013/08293-7. Computer simulations carried out during this research were supported by resources supplied by the Center for Scientific Computing (NCC/GridUNESP) of the São Paulo State University (UNESP). L.G.C. acknowledges FAPEMIG and the grant PRONAMETRO (52600.056330/2012). B.F acknowledges FAPEMIG and the grant PRONAMETRO (52600.030929/2014)

    Reducing natural vegetation loss in Amazonia critically depends on the formal recognition of indigenous lands

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    The Brazilian Amazon contains the world's largest tract of tropical forest, about 22 % of which is within demarcated indigenous territories. Formal governmental recognition of these traditional territories is often a critical deterrent to deforestation, but the relative conservation performance of Indigenous Lands (ILs) under different legal categories and geographic contexts remains poorly understood. We used 30-m resolution Landsat satellite imagery to quantitatively assess the land cover status and annual rates of natural vegetation loss between 1985 and 2020 for 381 indigenous territories amounting to ~115 million hectares. Using a comprehensive set of environmental and socio-economic covariates and a mixed-modelling approach, we found that all stages of formal IL recognition consistently inhibit natural vegetation loss throughout the Brazilian Amazon compared to adjacent unprotected areas. Formal physical demarcation and distance from roads were the main proximate drivers of avoided natural vegetation loss inside ILs. Forest loss associated with road access is substantially curbed by ILs, showing the importance of frontier expansion when assessing indigenous reserve performance in counteracting natural vegetation loss. Because loss of natural forest and savannah areas associated with agribusiness frontiers and infrastructure projects are likely to intensify, the importance of ecosystem services provided by ILs is expected to increase across the Brazilian Amazon. Cultural profile and human density exerted no impacts on IL effectiveness in precluding natural vegetation loss. Given widespread encroachment of timber extraction and agribusiness, formal recognition of indigenous territories is a critical factor in decelerating primary habitat conversion across the Amazon

    A Work Proposal for a Collaborative Study of Magnet Technology for a Future Muon Collider

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    In this paper we elaborate on the nature and challenges for the magnet systems of a muon collider as presently considered within the scope of the International Muon Collider Collaboration (IMCC). We outline the structure of the work proposed over the coming period of five years to study and demonstrate relevant magnet technology. The proposal, which is part of the overall work planned to establish feasibility of a muon collider, is in direct response to the recent recommendations received from the Laboratories Directors Group (LDG). The plan is to profit from joint activities, within the scope of the IMCC and beyond, implemented through direct and EU-funded contributions.Comment: contribution to Snowmass 202

    A Muon Collider Facility for Physics Discovery

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    Muon colliders provide a unique route to deliver high energy collisions thatenable discovery searches and precision measurements to extend ourunderstanding of the fundamental laws of physics. The muon collider design aimsto deliver physics reach at the highest energies with costs, power consumptionand on a time scale that may prove favorable relative to other proposedfacilities. In this context, a new international collaboration has formed tofurther extend the design concepts and performance studies of such a machine.This effort is focused on delivering the elements of a \sim10 TeV center ofmass (CM) energy design to explore the physics energy frontier. The path tosuch a machine may pass through lower energy options. Currently a 3 TeV CMstage is considered. Other energy stages could also be explored, e.g. ans-channel Higgs Factory operating at 125 GeV CM. We describe the status of theR&D and design effort towards such a machine and lay out a plan to bring theseconcepts to maturity as a tool for the high energy physics community.<br

    Risk of hospitalization for heart failure in patients with type 2 diabetes newly treated with DPP-4 inhibitors or other oral glucose-lowering medications: A retrospective registry study on 127,555 patients from the Nationwide OsMed Health-DB Database

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    Aims Oral glucose-lowering medications are associated with excess risk of heart failure (HF). Given the absence of comparative data among drug classes, we performed a retrospective study in 32 Health Services of 16 Italian regions accounting for a population of 18 million individuals, to assess the association between HF risk and use of sulphonylureas, DPP-4i, and glitazones. Methods and results We extracted data on patients with type 2 diabetes who initiated treatment with DPP-4i, thiazolidinediones, or sulphonylureas alone or in combination with metformin during an accrual time of 2 years. The endpoint was hospitalization for HF (HHF) occurring after the first 6 months of therapy, and the observation was extended for up to 4 years. A total of 127 555 patients were included, of whom 14.3% were on DPP-4i, 72.5% on sulphonylurea, 13.2% on thiazolidinediones, with average 70.7% being on metformin as combination therapy. Patients in the three groups differed significantly for baseline characteristics: age, sex, Charlson index, concurrent medications, and previous cardiovascular events. During an average 2.6-year follow-up, after adjusting for measured confounders, use of DPP-4i was associated with a reduced risk of HHF compared with sulphonylureas [hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.62-0.97; P = 0.026]. After propensity matching, the analysis was restricted to 39 465 patients, and the use of DPP-4i was still associated with a lower risk of HHF (HR 0.70; 95% CI 0.52-0.94; P = 0.018). Conclusion In a very large observational study, the use of DPP-4i was associated with a reduced risk of HHF when compared with sulphonylureas
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