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Capacitorless Solid-state Power Filter for Single-phase DC-AC Converters

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CES Transactions on Electrical Machines and Systems 2024年第3期8卷 367-377页

作者： Haitham Kanakri Euzeli C.dos santos Purdue University Electrical and Computer Engineering DepartmentIndianapolisIN46202 USA

Converters rely on passive filtering as a crucial element due to the high-frequency operational characteristics of power *** filtering methods involve a dual inductor-capacitor(LC)cell or an inductor-capacitor-inductor(LCL)***,capacitors are susceptible to wear-out mechanisms and failure ***,the necessity for monitoring and regular replacement adds to an elevated cost of ownership for such *** utilization of an active output power filter can be used to diminish the dimensions of the LC filter and the electrolytic dc-link capacitor,even though the inclusion of capacitors remains an indispensable part of the *** paper introduces capacitorless solid-state power filter(SSPF)for single-phase dc-ac *** proposed configuration is capable of generating a sinusoidal ac voltage without relying on *** proposed filter,composed of a planar transformer and an H-bridge converter operating at high frequency,injects voltage harmonics to attain a sinusoidal output *** design parameters of the planar transformer are incorporated,and the impact of magnetizing and leakage inductances on the operation of the SSPF is *** analysis,supported by simulation and experimental results,are provided for a design example for a single-phase *** total harmonic distortion observed in the output voltage is well below the IEEE 519 *** system operation is experimentally tested under both steady-state and dynamic conditions.A comparison with existing technology is presented,demonstrating that the proposed topology reduces the passive components used for filtering.

关键词： Solid-state power filter(SSPF) Capacitorless topology Active output power filter(AOF) Planar transformer Electrolytic capacitor Lifetime Wear-out mechanisms

Pharmacological therapy used in the elimination of Helicobacter pylori infection:A review

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World Journal of Gastroenterology 2015年第1期21卷 139-154页

作者： Ariolana A dos santos Adriana A Carvalho Department of Pharmacy Federal University of SergipeCampus Lagarto49400-00 LagartoSergipeBrazil

The optimal therapy for Helicobacter pylori(***) infection should combine a high cure rate and a short treatment duration with a favorable side-effect profile and should maintain a low *** strategies have been proposed to increase the *** eradication rate,including the extension of the treatment duration to 14 d,the use of a four-drug regimen(quadruple,sequential,and concomitant treatments),and the use of novel antibiotics,such as ***,triple therapy remains the most widely accepted firstline treatment regimen in Brazil and the United Statesand throughout *** this therapy is limited by resistance to clarithromycin,other therapeutic regimens have been investigated *** review describes the current literature involving studies directly comparing these different therapies and their efficacies.

关键词： Clarithromycin resistant Helicobacter pylori Pepti

Saturated anisotropic hydraulic conductivity of a compacted lateritic soil

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 986-991页

作者： Roberto Aguiar dos santos Edmundo Rogerio Esquivel Varzea Grande Institute of Engineering Federal University of Mato Grosso Cuiaba Mato Grosso Brazil Sao Carlos School of Engineering University of Sao Paulo Sao Carlos Sao Paulo Brazil

This study focuses on the saturated anisotropic hydraulic conductivity of a compacted lateritic clayey sandy soil. The effects of the molding water content and the confining stress on the anisotropic hydraulic conductivity are investigated. The hydraulic conductivity is measured with a flexible-wall permeameter. Samples are dynamically compacted into the three compaction states of a standard Proctor compaction curve： the dry branch, optimum water content and wet branch. Depending on the molding water content and confining stress, the hydraulic conductivity may increase or decrease. In addition, the results indicate that, when the samples are compacted to the optimum water content, lower hydraulic conductivity is obtained, except at a confining stress equal to 50 kPa. The increase of the confining stress decreases the hydraulic conductivity for each of the evaluated compaction states. In the wet branch, horizontal hy- draulic conductivity is about 8 times higher than the vertical value. The anisotropic hydraulic conduc- tivities of the dry and wet branches decrease when the confining stress increases, and the opposite is observed in the optimum water content state.

关键词： Hydraulic conductivity Anisotropic behavior Lateritic soil Tropical soil Compacted soil

Influence of a non-rotating shoulder on heat generation,microstructure and mechanical properties of dissimilar AA2024/AA7050 FSW joints

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Journal of Materials Science & Technology 2018年第1期34卷 119-127页

作者： Alessandro Barbini Jan Carstensen Jorge F.dos santos Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics Solid-State Joining Processes (WMP)

Friction stir welding （FSW） and stationary shoulder friction stir welding （SSFSW） were carried out for the butt joining of dissimilar AA2024-T3 and AA7050-T7651 aluminium alloys with thicknesses of 2 mm. A comparison between the two processes was performed by varying the welding speed while keeping the rotational speed constant, Through the analysis of the force and torque produced during welding and a simple analytical model, it was possible to show that in SSFSW there is more effective coupling with the tool and the heat produced is more efficiently distributed. This process decreases both the welding area and the diffusion at the interface of the two alloys compared with FSW. The minimum microhardness occurred at the advancing side （AS） at the interface between the thermo-mechanically affected zone （TMAZ） and the stir zone （SZ） in both processes, although the decrease was more gradual in SSFSW. This interface is also where all specimens failed for both welding technologies. An increase in tensile strength was measured in SSFSW compared with standard FSW. Furthermore, it was possible to establish the mechanical performance of the material in the fracture zone using digital image correlation.

关键词： Stationary shoulder friction stir welding Friction stir welding Dissimilar welded joints Process analysis Microstructure analysis Mechanical behaviour

Microencapsulated oregano and cinnamon essential oils as a natural alternative to reduce Listeria monocytogenes in Italian salami

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Food Bioscience 2022年第6期50卷 1766-1773页

作者： Franciele Maria Gottardo Bárbara Biduski Lára Franco dos santos Jucilene Sena dos santos Laura Beatriz Rodrigues Luciana Ruschel dos santos Graduate Program in Food Science and Technology University of Passo FundoBR 28599052-900Passo FundoRSBrazil Food Quality and Sensory Science Department Teagasc Food Research CentreAshtownDublinD15 KN3KIreland Graduate Program in Bioexperimentation University of Passo FundoBR 28599052-900Passo FundoRSBrazil College of Agronomy and Veterinary Science University of Passo FundoBR 28599052-900Passo FundoRSBrazil

Meat products are classified as perishable foods and have favourable conditions for the multiplication of microorganisms such as Listeria monocytogenes,an important pathogen associated with ready-to-eat *** compounds are used for food preservation combined with encapsulation techniques to improve *** study evaluated the anti-Listeria potential of isolated and combined microencapsulated oregano(OEO)and cinnamon(CEO)essential oils in Italian *** combination ratios of OEO and CEO were tested and 50:50 ratio(OEO:CEO)was encapsulated using sodium *** microcapsules were evaluated for encapsulation efficiency(EE),morphology and action against *** in a meat *** microcapsules and 50/50 combined EO were incorporated into the Italian salami to evaluate the physicochemical,microbiological and sensory *** combinations of EO showed *** inhibition zone and CIM with 1:16 *** microencapsulated EO had 98.36%encapsulation *** 2%microcapsule had a significant reduction of *** from the *** though the panellists mentioned the sandy attribute in the CATA,the salami with EO microcapsules texture did not differ from the *** the essential oils had high encapsulation efficiency,the smell and flavour of cinnamon and oregano interfered negatively with the sensory ***,the encapsulation of the combined essential oils(50/50)significantly reduced *** in Italian salami.

关键词： Natural antimicrobial Sodium alginate Ready-to-eat Encapsulation

Building capabilities in natural resource-dependent economies:An innovation systems analysis of the TVET program in Guyana

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International Journal of Innovation Studies 2019年第1期3卷 1-11页

作者： Chantal dos santos Friedrich-Alexander University Erlangen-Nuremberg 91054 ErlangenGermany

This paper examines Guyana's technical and vocational education and training(TVET)system in relation to diversifying the country's economy away from natural resource *** innovation systems approach is used to examine the effectiveness of TVET as a means of building capabilities in Guyana's key industries,gold and sugar,providing a snapshot of the state of the system in early,*** interviewees across several areas of expertise were consulted in Georgetown,*** analysis of primary and secondary research finds TVET's effectiveness to be limited by a lack of labor market information and funding,energy costs,a“brain drain”,and insufficient information communication technology skills and *** remedies include increasing the frequency of labor market surveys,attracting the Guyanese diaspora back to share knowledge,reducing the cost of energy by taking advantage of domestic renewable energy potential,and setting up a Sovereign Wealth Fund.

关键词： Innovation systems Guyana CARICOM Natural resources TVET

Proposals of SPT-CPT and DPL-CPT correlations for sandy soils in Brazil

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1152-1158页

作者： Mirella Dalvi dos santos Kátia Vanessa Bicalho Universidade Federal do Espírito Santo VitóriaBrazil

Field tests in geotechnical engineering are fundamental for identification of the underground *** standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).

关键词： Standard penetration test(SPT) Cone penetration test(CPT) Dynamic probing light(DPL) Correlations Sands Statistical evaluations

Molecular approaches for spinal cord injury treatment

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Neural Regeneration Research 2023年第1期18卷 23-30页

作者： Fernanda Martins de Almeida Suelen Adriani Marques Anne Caroline Rodrigues dos santos Caio Andrade Prins Fellipe Soares dos santos Cardoso Luiza dos santos Heringer Henrique Rocha Mendonça Ana Maria Blanco Martinez Laboratório de Neurodegeneração e Reparo Programa de Pós-Graduação em Medicina:Anatomia PatológicaDepartamento de PatologiaFaculdade de MedicinaHospital Universitário Clementino Fraga FilhoCentro de Ciências da SaúdeUniversidade Federal do Rio de JaneiroRio de JaneiroBrazil Instituto de Ciências Biomédicas Centro de Ciências da SaúdeUniversidade Federal do Rio de JaneiroRio de JaneiroBrazil Instituto de Biologia Departamento de NeurobiologiaLaboratório de Regeneração Neural e FunçãoUFFRio de JaneiroBrazil Laboratório Integrado de Morfologia Instituto de Biodiversidade e Sustentabilidade NUPEMPrograma de Pós-graduação Multicêntrico em Ciências Fisiológicas-SBFisCentro Multidisciplinar UFRJ-MacaéUniversidade Federal do Rio de JaneiroMacaéBrazil

Injuries to the spinal cord result in permanent disabilities that limit daily life *** main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic *** decades of research,there is still no efficient treatment for spinal cord *** strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord *** these,molecular compounds are currently being used for neurological recovery,with promising *** molecules target the axon collapsed growth cone,the inhibitory microenvironment,the survival of neurons and glial cells,and the re-establishment of lost *** this review we focused on molecules that are being used,either in preclinical or clinical studies,to treat spinal cord injuries,such as drugs,growth and neurotrophic factors,enzymes,and *** mechanisms of action of these molecules are discussed,considering traumatic spinal cord injury in rodents and humans.

关键词： axonal regeneration drugs enzymes growth factors molecular therapy neurotrophic factors purines spinal cord injury

A Numerical Comparison Between Quasi-Monte Carlo and Sparse Grid Stochastic Collocation Methods

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Communications in Computational Physics 2012年第9期12卷 1051-1069页

作者： Juarez dos santos Azevedo Saulo Pomponet Oliveira CETEC-UFRB Centro44380-000Cruz das Almas-BABrazil.2 DMAT-UFPRCentro Politecnico81531-980Curitiba-PRBrazil

Quasi-Monte Carlo methods and stochastic collocation methods based on sparse grids have become popular with solving stochastic partial differential *** methods use deterministic points for multi-dimensional integration or interpolation without suffering from the curse of *** is not evident which method is best,specially on random models of physical *** numerically study the error of quasi-Monte Carlo and sparse gridmethods in the context of groundwater flow in heterogeneous *** particular,we consider the dependence of the variance error on the stochastic dimension and the number of samples/collocation points for steady flow problems in which the hydraulic conductivity is a lognormal *** suitability of each technique is identified in terms of computational cost and error tolerance.

关键词： Karhunen-Loève expansion Monte Carlo quasi-Monte Carlo sparse grid