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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

Hybrid Triboelectric-Electromagnetic Nanogenerators for Mechanical Energy Harvesting:A Review

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Nano-Micro letters 2021年第12期13卷 163-220页

作者： Joao V.Vidal Vladislav slabov andrei l.Kholkin Marco P.soares dos santos Department of Physics and CICECO-Aveiro Institute of Materials University of Aveiro3810-193 AveiroPortugal Department of Physics and I3N University of Aveiro3810-193 AveiroPortugal laboratory of Functional low-Dimensional structures National University of Science and Technology MISISMoscowRussia Department of Mechanical Engineering Centre for Mechanical Technology and Automation(TEMA)University of Aveiro3810-193 AveiroPortugal

Motion-driven electromagnetictriboelectric energy generators(E-TENGs) hold a Hybrid triboelectric-electromagnetic generators C A Bgreat potential to provide higher voltages,higher currents and wider operating bandwidths than Cantilever generators1 μm both electromagnetic and triboelectric generators Rotating generatorssliding generators standing alone. Therefore,they are promising solutions to autonomously supply a broad range of Flexible blade generators Magnetoelectric highly sophisticated devices. This paper provides generators a thorough review focused on major recent breaklinear generators Multidimensional generators throughs in the area of electromagnetic-triboelectric vibrational energy harvesting. A detailed Pendulum generators analysis was conducted on various architectures including rotational,pendulum,linear,sliding,cantilever,flexible blade,multidimensional and 1 cm magnetoelectric,and the following hybrid technologies. They enable highly e cient ways to harvest electric energy from many forms of vibrational,rotational,biomechanical,wave,wind and thermal sources,among others. Open-circuit voltages up to 75 V,short-circuit currents up to 60 mA and instantaneous power up to 144 mW were already achieved by these nanogenerators. Their transduction mechanisms,including proposed models to make intelligible the involved physical phenomena,are also overviewed here. A comprehensive analysis was performed to compare their respective construction designs,external excitations and electric outputs. The results highlight the potential of hybrid E-TENGs to convert unused mechanical motion into electric energy for both large-and small-scale ***,this paper proposes future research directions toward optimization of energy conversion e ciency,power management,durability and stability,packaging,energy storage,operation input,research of transduction mechanisms,quantitative standardization,system integration,miniaturization and multi-energy hybrid cells.

关键词： E-TENG Hybrid triboelectric-electromagnetic Nanogenerators Energy harvesting

Influence of lDH conversion coatings on the adhesion and corrosion protection of friction spot-joined AA2024-T3/CF-PPs

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Journal of Materials science & Technology 2021年第8期67卷 197-210页

作者： A.C.Bouali N.M.andre M.R.silva Campos M.serdechnova J.F.dos santos s.T.Amancio-Filho M.l.Zheludkevich Institute of Materials Research Helmholtz-Zentrum G eesthacht.Magnesium Innovation CentreCorrosion and Surface TechnologyMax-Planck-Straβe 121502 CeesthachtGermany Institute of Materials Research Helmholtz-Zentrum GeesthachtMaterials MechanicsSolid State Joining ProcessesMax-Planck-Straβe 121502 CeesthachtGermany Graz University of Technology-TU Graz Institute of Materials Sciencejoining and FormingBMK Endowed Professorship for AviationKopemikusgasse 24/18010 GrazAustria Faculty of Engineering University of KielKaiserstrasse 224143 KielGermany

layered double hydroxide(lDH)conversion coatings loaded with corrosion inhibitors were suggested for the surface treatment of the aluminum alloy 2024-T3,prior to friction spot joining with carbon-fiber reinforced polyphenylene sulfide(AA2024-T3/CF-PPs).Vanadate was used as a model corrosion *** shear testing method revealed an increase of approx.20%of the joint’s adhesion performance when treated with lDH and before exposure to salt *** evaluation of the joints after exposure to salt spray demonstrated a significant difference in the corrosion behavior of the joints when the AA2024-T3 is treated with lDH loaded with nitrate and vanadate *** lDH intercalated with nitrate revealed a clear improvement in the mechanical and corrosion resistance performance of the joints,even after 6 weeks of salt ***,the lDH intercalated with vanadate failed in providing protection against corrosion as well as preserving the mechanical properties of the *** effect of the galvanic corrosion was further investigated by zero resistance ammeter(ZRA)measurements as well as localized scanning vibrating electrode technique(sVET).

关键词： Friction spot joining layered double hydroxide Galvanic couple Corrosion protection Adhesion

Numerical study on the Effect of submerged Depth on the Horizontal Plate Wave Energy Converter

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China Ocean Engineering 2014年第5期28卷 687-700页

作者： Flávio Medeiros sEIBT Eduardo Costa COUTO Elizaldo Domingues dos santos liércio andré IsOlDI luiz Alberto Oliveira ROCHA Paulo Roberto de Freitas TEIXEIRA Graduate Program of Ocean Engineering Universidade Federal do Rio Grande96203-900 Rio Grande RS Brazil Mechanical Engineering Department Universidade Federal do Rio Grande do Sul90050-170 Porto Alegre RS Brazil

The growing search for clean and renewable energy sources has given rise to the studies of exploring sea wave energy. This paper is concerned with the numerical evaluation of the main operational principle of a submerged plate employed for the conversion of wave energy into electrical one. The numerical model used to solve the conservation equations of mass, momentum and transport of volume fraction is based on the finite volume method （FVM）. In order to tackle with the flow of mixture of air-water and its interaction with the device, the multiphase model volume of fluid （VOF） is employed. The purpose of this study is the evaluation of a numerical model for improvement of the knowledge about the submerged plate wave energy converter, as well as the investigation of the effect of the distance from the plate to the bottom of the sea （HP） on the performance of the converter. The simulations for several distances of the plate from the seabed show that the optimal efficiency is 64%, which is obtained for HP=0.53 m （88% of the depth）. This efficiency is 17% larger than that found in the worst case （HP=0.46 m, 77% of the depth）.

关键词： numerical simulation submerged plate wave energy conversion efficiency

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

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

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

In silico and in Vitro Analysis of Pyrazolone Derivatives against Zika Virus and Identification of Potential Ns5 Methyltransferase Inhibitors by Molecular Docking

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Journal of Biosciences and Medicines 2024年第7期12卷 214-229页

作者： luciene soares silva Tiago soares Barbosa Maria leonisa sanchez-Nuñez Aldenise Mont serrat Rosa da silva Vitor Won-Held Rabelo leonardo dos santos Corrêa Amorim leonardo Alves Miceli Percilene Fazolin Vegi Alice Bernardino Helena Carla Castro Izabel Christina Nunes de Palmer Paixão science and Biotechnology Graduate Program Department of Cellular and Molecular Biology Institute of Biology Fluminense Federal University Niteri Brazil science and Biotechnology Graduate Program Department of Cellular and Molecular Biology Institute of Biology Fluminense Federal University Niterói Brazil laboratory of Antibiotics Biochemistry Teaching and Molecular Modeling Institute of Biology Fluminense Federal University Niterói Brazil laboratory of Organic Chemistry at the Institute of Chemistry Institute of Biology Fluminense Federal University Niterói Brazil

Zika virus (ZIKV), a mosquito-borne flavivirus, has been associated with benign infections for decades. However, it has become a public health concern due to its association with severe fetal and neurological complications. Although many efforts have been made to control ZIKV infection, approved vaccines or antiviral drugs are still lacking. Consequently, the development of new effective anti-ZIKV agents is urgently needed. In this context, we investigated the antiviral potential of pyrazolone derivatives against ZIKV replication using in silico and in vitro methods. The four pyrazolone derivatives evaluated (1a, 1b, 1c, and 1d) inhibited over 50% of ZIKV replication with low cytotoxicity. Among them, compound 1b exhibited the most potent activity (EC50 = 4.3 μM) and the highest selectivity (sI = 342). Mechanism of action studies indicated that these compounds act at early stages of virus replication, and compound 1b can also directly inactivate ZIKV particles. Molecular docking studies suggested that these compounds can bind to and block the activity of ZIKV Ns5 methyltransferase. Finally, pharmacokinetic and toxicological predictions have reinforced the safety and drug-like profiles of these derivatives. In conclusion, the pyrazolone scaffold proved to be valuable for anti-ZIKV drug development, and the derivatives studied deserve further investigation.

关键词： Zika Pyrazolone Ns5 Methyltransferase Antivirals