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Effect of pier shape and pier alignment on the equilibrium scour depth at single piers

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International Journal of Sediment Research 2016年第3期31卷 244-250页

作者： Cristina Fael Rui Lana António Cardoso Faculdade de engenharia Universidade da Beira InteriorEdificio Ⅱ das EngenhariasCalcada Fonte da Lameiro instituto superior de engenharia/universidade do algarve instituto superior Tecnico Universidade de Lisboa

The equilibrium scour depth at uniform single bridge piers depends on a large number of variables,including the pier horizontal cross-section shape and its alignment angle towards the flow *** influence of these variables has been studied by only a few researchers,mostly,on the basis of tests that were far from approaching *** experimental study aims at revisiting the influence of piers’ shape and alignment on local scouring for length-width ratios smaller than or equal to 4,by increasing the experimental *** five long-duration laboratory tests were run under steady,clear-water flow,close to the threshold for initiation of sediment *** pier shapes were considered:circular,rectangular square-nosed,rectangular round-nosed,oblong,and zero-spacing(packed) pile-groups;the tested skew-angles were 0°,30°,45°,60°,and 90°.It was concluded that i) the shape factor can be taken as 1.0,for rectangular round-nosed and oblong cross-section piers,and as 1.2,for rectangular squarenosed and packed pile-group cross-section piers,ii) the shape factor does not vary significantly with the duration of tests,this way confirming the robustness of the shape factors reported to date,iii) the effect of shape is present at skewed piers although the associated coefficients remain in the narrow range of1.0-1.2,and iv) for length-width ratios smaller than 4,the shape factor is of the same order of magnitude as the skew angle factor and should not be neglected.

关键词： Scour Pier shape Pier alignment

Proposal of a fireproof design code for dwellings against the action of wildland fires

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Resilient Cities and Structures 2023年第3期2卷 104-119页

作者： M.R.T.Arruda A.R.A.Bicelli P.Cantor E.B.Assis F.Branco CERIS Instituto Superior TécnicoUniversidade de LisboaPortugal Escola de engenharia de São Carlos Universidade de São PauloBrazil instituto superior Técnico Universidade de LisboaPortugal

This study proposes a concept for the development of a fireproof design code for the verification of dwellings susceptible to wildfire *** are currently structural codes for the design of buildings when subjected to indoor fires,outside fires that grow on the facade of buildings,and even fires in an accident situation due to ignitions with hydrocarbons or transportation *** of these security verification specifications are described in EC1:*** current regulation in Portugal uses safety criteria and risk categories that are for indoor fires,therefore is very conservative and may not present an economic fireproof design against the action of *** aim of this work is a straight verification based on natural temperature characteristic curves that simulate wildfire heat flow by convection,radiation,and the deposits of firebrands.

关键词： Structural safety verification Wildfires in dwellings Nominal fires vs natural fires Fireproof construction guidelines

Experimental and numerical characterization of 3D‑printed scaffolds under monotonic compression with the aid of micro‑CT volume reconstruction

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Bio-design and Manufacturing 2021年第2期4卷 222-242页

作者： R.Baptista M.F.C.Pereira A.Maurício D.Rechena V.Infante M.Guedes CDP2T Departamento de Engenharia MecanicaEscola Superior de Tecnologia de SetúbalInstituto Politécnico de Setúbal2910‑761 SetúbalPortugal CERENA DECivilInstituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IDMEC Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IPFN Instituto Superior TécnicoUniversidade de Lisboa1049‑001 LisbonPortugal CeFEMA Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal

Even when damaged by injury or disease bone tissue has the remarkable ability to *** this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improving tissue *** are support structures,designed to be implanted in the damaged site,supporting mechanical loads and protecting the regenerating bone *** this paper,3D-printed PLA scaffolds with three different porosity values and two different geometries were experimentally and numerically ***-CT analysis showed that fused filament fabrication can be used to produce scaffolds with the desired porosity and 100%of interconnected *** monotonical compression,scaffolds apparent compressive modulus increased from 89 to 918 MPa,while yield stress increased from 2.9 to 27.5 MPa as porosity decreased from 70 to 30%.Open porosity decreased up to 8%on aligned scaffolds and 14%on staggered scaffolds,after compression,while scaffold’s surface-to-volume ratio highest reduction(7.48 to 4.55 mm−1)was obtained with aligned low porosity ***-CT volume reconstruction allowed for scaffold simplified numerical models to be built and *** agreement was found when predicting scaffold’s apparent compressive ***,it can be concluded that 3D printing is a viable scaffold manufacturing technique for trabecular bone replacement.

关键词： Scaffold Pore design Mechanical behavior Micro-CT analysis Finite element method

development and validation of SuperdeM for non-spherical particulate systems using a superquadric particle method

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Particuology 2022年第2期20卷 74-90页

作者： Xi Gao Jia Yu Ricardo J.F.Portal Jean-François Dietiker Mehrdad Shahnam William A.Rogers National Energy Technology Laboratory MorgantownWV 26506USA Leidos Research Support Team MorgantownWV 26506USA Centro de Investigação em Modelação e Otimização de Sistemas Multifuncionais Instituto Superior de Engenharia de LisboaPolytechnic Institute of Lisbon1959-007 LisboaPortugal instituto de engenharia Mecânica–instituto superior Técnico Universidade de Lisboa1049-001 LisboaPortugal

This article presents the development and validation of the Superquadric Discrete Element Method(SuperdeM)for non-spherical particle simulation using a superquadric particle method in open-source CFD suite MFiX.A superquadric particle-particle contact algorithm with accelerating and stabilizing strategy was developed.A superquadric particle-arbitrary wall contact algorithm was developed,which enables the simulation in complex *** solver was validated by comparing with experimental data generated in this study or available in the *** include cylinder contacting with a wall,static packing of M&M chocolate candies in a cylindrical container,static packing of cylinders in a cylindrical container,dynamic angle of repose of cylinders in a rotating drum,and discharging of chocolate candies from a ***,MPI parallelization of the solver was implemented and the parallel performance of the solver using MPI was assessed through large-scale simulations of 1 million,10 million,and 100 million particles on up to 6800 cores,which demonstrates that the SuperdeM solver has great potential for industrial-scale systems simulation.

关键词： deM Particle Non-spherical Superquadric Parallelization MFiX

The CASTOR-K Code,Recent developments and Applications

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Plasma Science and Technology 2015年第2期17卷 89-96页

作者： F.NABAIS D.BORBA R.COELHO A.FIGUEIREdo J.FERREIRA N.LOUREIRO P.RODRIGUES Associao EURATOM/IST Instituto de Plasmas e Fuso Nuclear-Instituto Superior TcnicoUniversidade de Lisboa

The CASTOR-K code is a hybrid magnetohydrodynamic （MHD）-drift kinetic code developed for the study of MHD modes in the presence of energetic ion populations. It allows a fast assessment of the linear stability of the modes, as well as an accurate calculation of damping due to thermal species （Landau damping）. These capabilities make the code an invaluable tool for parametric studies and data analysis. In recent years, CASTOR-K has been mostly used to analyze JET data, including the identification of mechanisms involved in the expulsion of energetic ions from the plasma. However, in order to prepare the code to be used for a wider range of tokamaks including ITER, the code is being subject to a series of important improvements. These improvements aim not only to introduce new physics in the code but also to make it capable of exchanging data with other codes through its integration in modelling infrastructures. In this paper a description of the CASTOR-K code is presented, as well as a summary of the most important results obtained with this code and a description of the new improvements being implemented.

关键词： controlled fusion tokamaks plasma instabilities magnetohydrodynamics(MHD) Alfven waves energetic particles

A European digital accelerometric database:statistical analysis of engineering parameters of small to moderate magnitude events

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Earthquake Engineering and Engineering Vibration 2014年第4期13卷 583-597页

作者： Carlos S.Oliveira Gerard Gassol Xavier Goula Teresa Susagna instituto superior Técnico Universidade de Lisboa Institut Cartogràfic i Geològic de Catalunya

During the NERIES Project, an accelerometric database containing European digital information was developed. Besides event and station metadata, ground motion parameters, computed in a homogeneous manner, were assembled： PGA, PGV, AI, TD, CAV, H1 and PSV（f,5%）（19,961 components, 2629 events, 547 stations）. Merging small and moderate magnitude events produced a unique database capable of providing important information such as：（i） Correlations between several ground motion parameters follow analogous trends as in previous worldwide datasets, with slight corrections. （ii） Although PGA attenuations with distance show great uncertainties, four recent GMPEs recommended for Europe fit quite well the central 50% data interval for the distance range 10 〈 R 〈 200 kin; outside these distances, they do not fit. （iii） Soil amplification ratios indicate that weak motion （low magnitudes and larger distances） shows larger amplification than strong motion （short distances and large magnitudes） as represented in UBC97 for the USA, but not in EC8 for Europe. （iv） Average spectral shapes are smaller than in the EC8. （v） Differences in amplification factors for PGA, PGV and HI for EC8 soil classes B and C, and differences in spectral shapes for these soil classes, indicate that EC8, Type 2 S-coefficient should be frequency dependent, as in UBC97.

关键词： NERIES project parametric accelerometric database European region PGA EC8 soil amplification

Comparison of Electron Acceleration Ability of SiO_2 and ZnS fromZnS∶Er Transient Electroluminescence

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Journal of Rare Earths 2006年第3期24卷 298-301页

作者：张福俊徐征刘玲孟立建 Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing 100044 China Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing 100044 ChinaDepartmento de Fisica Instituto Superior de Engenharia do Porto 4200-072 Porto Protugal departmento de Fisica instituto superior de engenharia do Porto 4200-072 Porto Protugal

The acceleration ability of electrons in SiO2 and ZnS was compared through the variation of emission intensity based on ZnS ： Er electroluminescence during the reverse of polarity of sinusoidal voltage. In order to avoid the influence of work function of electrode, cathodal and anodal materials were ITO （indium tin oxide）. The ratio of maximum emission intensity under positive and negative half period is 2.18. This result demonstrates that the electron acceleration ability of SiO2 is 2.18 times stronger than that of ZnS.

关键词： electron acceleration rare earths

Modified Joint Distribution of Wave Heights and Periods

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China Ocean Engineering 2016年第3期30卷 359-374页

作者： H.D.Zhang C.Guedes Soares Centre for Marine Technology and Ocean Engineering (CENTEC) Instituto Superior Técnico Universidade de Lisboa

The modified versions of the linear theoretical model of Longuet-Higgins （1983） are derived in this work and also compared with the laboratory experiments carried out in MAR1NTEK. The main feature of modifications is to replace the mean frequency in the formulation with the peak frequency of the wave spectrum. These two alternative forms of joint distributions are checked in three typical random sea states characterized by the initial wave steepness. In order to further explore the properties ＆these models, the associated marginal distributions of wave heights and wave periods are also researched with the observed statistics and some encouraging results are obtained.

关键词： Longuet-Higgins joint distribution mixed sea state nonlinear wave series wave height wave period

The neuroprotective effect of traditional Chinese medicinal plants--A critical review

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Acta Pharmaceutica Sinica B 2023年第8期13卷 3208-3237页

作者： Joao Moreira Mariana Machado Monica Dias-Teixeira Ricardo Ferraz Cristina delerue-Matos Clara Grosso REQUIMTE/LAQV Instituto Superior de Engenharia do PortoInstituto Politecnico do PortoPorto 4249-015Portugal Ciencias Químicas e das Biomoleculas/CISA Escola Superior de SaudedInstituto Politecnico do PortoPorto 4200-072Portugal NICiTeS-Nucleo de Investigacao em Ciencias e Tecnologias da Saude Escola Superior de Saude Ribeiro SanchesLisboa 1950-396Portugal REQUIMTE/LAQV Departamento de Química e Bioquímica Faculdade de CienciasUniversidade do PortoPorto 4169-007Portugal

Neurodegenerative and neuropsychiatric diseases are increasingly affecting individuals’quality of life,thus increasing their cost to social and health *** diseases have overlapping mechanisms,such as oxidative stress,protein aggregation,neuroinflammation,neurotransmission impairment,mitochondrial dysfunction,and ***,there is no cure for neurodegenerative diseases,and the available therapies have adverse effects and low *** neuropsychiatric disorders,such as depression,the current therapies are not adequate to one-third of the patients,the so-called treatmentresistant ***,searching for new treatments is *** plants appear as a strong alternative and complement towards new treatment protocols,as they have been used for health purposes for thousands of ***,the main goal of this review is to revisit the neuroprotective potential of some of the most predominant medicinal plants(and one fungus)used in traditional Chinese medicine(TCM),focusing on their proven mechanisms of action and their chemical compositions,to give clues on how they can be useful against neurodegeneration progression.

关键词： Neurodegeneration Alzheimer's disease Parkinson's disease depression Medicinal plants Oxidative stress Toxicology Clinicaltrials