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Synthesis of Mesoporous Material from Chrysotile-Derived Silica

Materials Sciences and Applications 2013年第8期4卷 68-72页

作者： Anderson Joel Schwanke christian wittee lopes Sibele Berenice Castella Pergher PPGCEM Universidade Federal do Rio Grande do NorteNatalBrazil Chemistry Institute Universidade Federal do Rio Grande do NorteNatalBrazil

Mesoporous MCM-41-type molecular sieves were synthesized using calcined and leached chrysotile and cetyltrimethylammonium bromide as the silica source and structure directing agent, respectively. Powder X-ray diffraction (XRD), N2 isothermal adsorption-desorption, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were used to characterize the samples. The calcined and leached chrysotile can be employed as an inexpensive silica source for the formation of low-order MCM-41 mesoporous materials.

关键词： MCM-41 Chrysotile Silica Source

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Simulation of Gamma-Ray and Neutron Spectrometers for Microsatellite Missions

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Journal of Geoscience and Environment Protection 2018年第8期6卷 105-132页

作者： Masayuki Naito Nobuyuki Hasebe Junya Ishii José A.Matias-lopes Valery V.Dmitrenko christian Wohler Kyeong Ja Kim School of Advanced Science and Engineering Waseda UniversityTokyoJapan Research Institute for Science and Engineering Waseda UniversityTokyoJapan Department of Physics University of CoimbraCoimbraPortugal National Research Nuclear University MEPhI MoscowRussia Image Analysis Group Dortmund University of TechnologyDortmundGermany Korea Institute of Gescience and Mineral Resources DaejeonSouth Korea

Microsatellites have recently opened windows of frequent and low cost missions for planetary exploration. The performance of gamma-ray and neutron spectrometers on future microsatellite missions is simulated to assess the possibility of observation of hydrogen and major elements, given their concentration on the observation target. The measured elemental abundance will provide important geological constraints, and some of them may serve as space resources. Four different types of target bodies with various hydrogen concentrations in the range of 0 - 20,000 ppm are assumed as target compositions;Earth’s core, C-type, S-type and Martian meteorites. Gamma-ray and neutron emission rates show unique footprints that are related to the different elemental compositions. The starting point is the solid angle subtended between observation target and spectrometers that allow estimating the gamma-ray and neutron count rates emitted by the celestial bodies. In this work, three types of gamma-ray detectors;high-purity germanium (HPGe), CeBr3 and LaBr3(Ce), a neutron spectrometer combining a lithium glass scintillator with a boron loaded plastic scintillator and a dual mode spectrometer Cs2LiYCl6(Ce) (CLYC) are simulated, focusing on their observation backgrounds as a model case for microsatellite based measurements. The background count level of both gamma-ray (except for the LaBr3 detector) and neutron count rates was negligible under these particular conditions. The gamma-ray detectors were compared by the figure of merit, which was determined by their efficiency and energy resolution. It was found that each detector has unique advantages. The HPGe detector has the highest figure of merit due to its excellent energy resolution, whereas the CLYC detector is low in weight and power consumption due to its dual sensitivity to gamma-ray and neutron. The CeBr3 detector is an intermediate choice. The neutron count rates are calculated separately in three energy ranges, i.e. , thermal

关键词： Gamma-Ray Spectrometer Neutron Spectrometer Microsatellite.High Purity Germanium CeBr3 LaBr3(Ce) CLYC

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Predictors of surgical complications in boys with hypospadias:data from an international registry

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World Journal of Pediatric Surgery 2023年第4期6卷 217-223页

作者： Kathryn Scougall Jillian Bryce Federico Baronio Rachel L Boal Jose Roberto Castera Sebastián Castro Tim Cheetham Eduardo Correa Costa Feyza Darendeliler Justin H Davies Mirjam Dirlewanger Gabriella Gazdagh Evgenia Globa Gil Guerra-Junior Tulay Guran Gloria Herrmann Paul-Martin Holterhus Ahsen KaragözlüAkgül Renata Markosyan Kenneth McElreavey Marcio lopes Miranda Anna Nordenstrom Stuart O’Toole Sukran Poyrazoglu Gianni Russo Valerie Schwitzgebel Marianna Stancampiano Michael Steigert S Faisal Ahmed Angela K Lucas-Herald University of Glasgow GlasgowUK IRCCS Azienda Ospedaliero-Universitaria di Bologna Policlinico S Orsola BolognaItaly Great North Children's Hospital Newcastle Upon TyneUK Hospital de Ninos Ricardo Gutiérrez Buenos AiresArgentina Hospital de Clinicas de Porto Alegre Porto AlegreBrazil Istanbul University IstanbulTurkey Southampton Children's Hospital SouthamptonUK University Hospital of Geneva GenevaSwitzerland Ukrainian Research Center of Endocrine Surgery Endocrine Organs and Tissue Transplantation KyivUkraine State University of Campinas CampinasBrazil Marmara University IstanbulTurkey University Medical Centre UlmGermany University Hospital of Schleswig-Holstein Campus Kiel/christian-Albrechts-University of Kiel KielGermany Marmara University Faculty of Medicine IstanbulTurkey Yerevan State Medical University Endocrinology Clinic YerevanArmenia Institut Pasteur ParisFrance Karolinska University Hospital StockholmSweden Royal Hospital for Children GlasgowUK IRCCS Ospedale San Raffaele MilanoItaly Graubunden Cantonal Hospital ChurSwitzerland

Background Complications are frequently reported after hypospadias repair and there is a need to understand the factors that influence their *** Data from boys with hypospadias born between 2000 and 2020 were obtained from the International Disorders of Sex Development(l-DSD)*** regressions,fisher's exact tests and spearman's correlation tests were performed on the data to assess associations between clinical factors and complication *** Of the 551 eligible boys,data were available on 160(29%).Within the cohort,the median(range)External Masculinization Score(EMS)was 6(2,9).All presented with one or more additional genital malformation and 61(38%)presented with additional extragenital *** of androgen action,androgen synthesis and gonadal development were diagnosed in 28(18%),22(14%)and 9(6%)boys,*** remaining 101(62%)patients were diagnosedas having non-specific 46,XY Disorders of Sex ***(50%)boys had evidence of abnormal biochemistry,and gene variants were identified in 42(26%).Median age at first hypospadias surgery was 2 years(0,9),and median length of follow-up was 5 years(0,17).Postsurgical complications were noted in 102(64%)*** were no significant associations with postsurgical *** Boys with proximal hypospadias in the I-DSD Registry have high rates of additional comorbidities and a high risk of postoperative *** clinical factors were significantly associated with complication *** complication rates with no observable cause suggest the involvement of other factors which need investigation.

关键词： complications surgical involvement

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