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Hydroelastic Analysis of a Rectangular Plate Subjected to Slamming Loads

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Journal of Marine Science and Application 2017年第4期16卷 405-416页

作者： Shan Wang C.Guedes Soares Centre for Marine technology and Ocean Engineering(CENtEC) Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal

A hydroelastic analysis of a rectangular plate subjected to slamming loads is presented. An analytical model based on Wagner theory is used for calculations of transient slamming load on the ship plate. A thin isotropic plate theory is considered for determining the vibration of a rectangular plate excited by an external slamming force. the forced vibration of the plate is calculated by the modal expansion method. Analytical results of the transient response of a rectangular plate induced by slamming loads are compared with numerical calculations from finite element method. the theoretical slamming pressure based on Wagner model is applied on the finite element model of a plate. Good agreement is obtained between the analytical and numerical results for the structural deflection of a rectangular plate due to slamming pressure. the effects of plate dimension and wave profile on the structural vibration are discussed as well. the results show that a low impact velocity and a small wetted radial length of wave yield negligible effects of hydroelasticity.

关键词： slamming load hydroelastic analysis vibration of plates modal expansion method finite element method

Optimization of an innovative approach involving mechanical activation and acid digestion for the extraction of lithium from lepidolite

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 11-19页

作者： Nathalia Vieceli Carlos A.Nogueira Manuel F.C.Pereira Fernando O.Durao Carlos Guimaraes Fernanda Margarido Center for Innovation Technology and Po icy Research-IN+Instituto Superior T6cnicoUniversity of Lisbon1049-001 LisboaPortugal LNEG-Laborat6rio Nacional de Energia e Geologia I.P.Campus do Lumiar1649-038 LisboaPortugal CERENA-Centro de Recursos Naturais e Ambiente DECivilInstituto Superior T6cnicoUniversity of Lisbon1049-001 LisboaPortugal

the recovery of lithium from hard rock minerals has received increased attention given the high demand for this element. there- fore, this study optimized an innovative process, which does not require a high-temperature calcination step, for lithium extraction from le- pidolite. Mechanical activation and acid digestion were suggested as crucial process parameters, and experimental design and re- sponse-surface methodology were applied to model and optimize the proposed lithium extraction process. the promoting effect of amorphi- zation and the formation of lithium sulfate hydrate on lithium extraction yield were assessed. Several factor combinations led to extraction yields that exceeded 90%, indicating that the proposed process is an effective approach for lithium recovery.

关键词： lepidolite lithium mechanical activation acid digestion optimization extraction

Review of Ship Slamming Loads and Responses

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Journal of Marine Science and Application 2017年第4期16卷 427-445页

作者： Shan Wang C.Guedes Soares Centre for Marine technology and Ocean Engineering(CENtEC) Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal

the paper presents an overview of studies of slamming on ship structures. this work focuses on the hull slamming, which is one of the most important types of slamming problems to be considered in the ship design process and the assessment of the ship safety. there are three main research aspects related to the hull slamming phenomenon, a) where and how often a slamming event occurs, b) slamming load prediction and c) structural response due to slamming loads. the approaches used in each aspect are reviewed and commented, together with the presentation of some typical results. the methodology, which combines the seakeeping analysis and slamming load prediction, is discussed for the global analysis of the hull slamming of a ship in waves. Some physical phenomena during the slamming event are discussed also. Recommendations for the future research and developments are made.

关键词： review slamming probability ship slamming hydroelasticity

trefftz Spectral Analysis of Biphasic Media

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Trefftz Spectral Analysis of Biphasic Media

A Reference Model for the Analysis and Comparison of MDE Approaches for Web-Application Development

the Sixth World Congress on Computational Mechanics in Conjunction with the Second Asian-Pacific Congress on Computational Mechanics

作者： Joo A.teixeira de Freitas Ionut D.Moldovan Milan toma Departamento de Engenharia Civil e Arquitectura instituto superior técnico Universidade técnica de Lisboa av. rovisco pais 1049-001 Lisboa Portugal

the hybrid-trefftz finite element formulation is used to model the response of two-phase media in the frequency domain. the applications selected illustrate the relative advantage of trefftz elements over conventional elements in the modeling of wave propagation in unbounded saturated porous media and of the transient response of incompressible soft tissues.

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Journal of Software Engineering and Applications 2010年第5期3卷 419-425页

作者： Jo&atilde o de Sousa Saraiva Alberto Rodrigues da Silva INESC-ID/instituto superior técnico Lisboa Portugal INESC-ID/instituto superior técnico Lisboa Portugal

the emerging Model-Driven Engineering (MDE) paradigm advocates the use of models as first-class citizens in the software development process, while artifacts such as documentation and source-code can be quickly produced from those models by using automated transformations. Even though many MDE-oriented approaches, languages and tools have been developed in the recent past, there is no standard that concretely defines a specific sequence of steps to obtain a functional software system from a model. thus, the existing approaches present numerous differences among themselves, because each one handles the problems inherent to software development in its own way. this paper presents and discusses a reference model for the comparative study of current MDE approaches in the scope of web-application development. this reference model focuses on relevant aspects such as modeling language scope (domain, business-logic, user-interface), usage of patterns, separation of concerns, model transformations, tool support, and deployment details like web-platform independence and traditional programming required. the ultimate goal of this paper is to determine the aspects that will be of greater importance in future web-oriented MDE languages.

关键词： Model-Driven Engineering Web Engineering Software Development

Spin Number Coherent States and the Problem of two Coupled Oscillators

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Communications in theoretical Physics 2015年第7期64卷 34-38页

作者： D.Ojeda-Guillén R.D.Mota V.D.Granados Escuela superior de Fisica y Matemáticas Instituto Politécnico Nacional Ed. 9 Unidad Profesional Adolfo López Mateos Escuela superior de Ingenieria Mecánica y Eléctrica Unidad Culhuacán Instituto Politécnico Nacional

From the definition of the standard Perelomov coherent states we introduce the Perelomov number coherent states for any su(2) Lie algebra. With the displacement operator we apply a similarity transformation to the su(2)generators and construct a new set of operators which also close the su(2) Lie algebra, being the Perelomov number coherent states the new basis for its unitary irreducible representation. We apply our results to obtain the energy spectrum, the eigenstates and the partition function of two coupled oscillators. We show that the eigenstates of two coupled oscillators are the SU(2) Perelomov number coherent states of the two-dimensional harmonic oscillator with an appropriate choice of the coherent state parameters.

关键词： coherent states Lie algebras coupled oscillators

NDRank: optimised parallel search for weather analogues

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Big Earth Data 2023年第2期7卷 276-297页

作者： David Martins Miguel Ferreira João Nuno Silva instituto superior técnico Universidade de LisboaLisboaPortugal Caravela Energy Partners DarienConnecticutUSA Distributed Parallel and Secure Systems GroupINESC-ID LisboaLisboaPortugal

Global meteorology data are now widely used in various areas, but one of its applications, weather analogues, still require exhaustive searches on the whole historical data. We present two optimisations for the state-of-the-art weather analogue search algorithms: a parallelization and a heuristic search. the heuristic search (NDRank) limits of the final number of results and does initial searches on a lower resolution dataset to find candidates that, in the second phase, are locally validated. these optimisations were deployed in the Cloud and evaluated with ERA5 data from ECMWF. the proposed parallelization attained speedups close to optimal, and NDRank attains speedups higher than 4. NDRank can be applied to any parallel search, adding similar speedups. A substantial number of executions returned a set of analogues similar to the existing exhaustive search and most of the remaining results presented a numerical value difference lower than 0.1%. the results demonstrate that it is now possible to search for weather analogues in a faster way (even compared with parallel searches) with results with little to no error. Furthermore, NDRank can be applied to existing exhaustive searches, providing faster results with small reduction of the precision of the results.

关键词： Multidimensional arrays weather analogues search parallel computing algorithm optimisation

Microstructure and properties of laser direct deposited CuNi17Al3Fe1.5Cr alloy

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International Journal of Minerals,Metallurgy and Materials 2011年第3期18卷 325-329页

作者： Yong-zhong Zhang Can Huang Rui Vilar Center for Composites General Research Institute for Non-ferrous Metals Beijing 100088 China Department of Materials Engineering and Institute of Materials and Surfaces Science and Engineering Instituto Superior Técnico 1049-001 Lisbon Portugal

thin walls of a copper-base alloy with the nominal composition CuNi17Al3Fe1.5Cr were successfully prepared by laser direct deposition additive manufacturing. the microstructure, as revealed by optical and scanning electron microscopy, indicated that the deposited material was fully dense and with a dendritic microstructure. the dendrites are parallel to the build-up direction, which is also the heat con-duction direction during deposition. X-ray diffraction analysis results show that the deposited material is composed of a single phase and a copper-based solid solution. Some precipitate particles of metal silicides were observed in the interdendritic region by scanning electron mi-croscopy. the ultimate tensile strength along the laser scanning direction reaches 735 MPa. the hardness is about Hv0.1 300.

关键词： copper alloys laser deposition microstructure mechanical properties

Liver disorders in COVID-19,nutritional approaches and the use of phytochemicals

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World Journal of Gastroenterology 2021年第34期27卷 5630-5665页

作者： Nancy Vargas-Mendoza Jazmín García-Machorro Marcelo Angeles-Valencia Marlet Martínez-Archundia Eduardo Osiris Madrigal-Santillán Ángel Morales-González Liliana Anguiano-Robledo JoséA Morales-González Laboratorio de Medicina de Conservacion Instituto Politécnico NacionalMéxico 11340Mexico Laboratorio de Diseño y Desarrollo de Nuevos Fármacos e Innovación Biotécnológica Instituto Politécnico NacionalMéxico 11340Mexico superior de Medicina Instituto Politécnico NacionalMéxico 11340Mexico Escuela superior de Cómputo Instituto Politécnico NacionalMéxico 07738Mexico Laboratorio de Farmacología Molecular Instituto Politécnico NacionalMéxico 11340Mexico Laboratorio Medicina de Conservación Escuela Superior de MedicinaInstituto Politécnico NacionalMéxico 11340Mexico

Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2),has affected millions of people *** was declared a pandemic by the World Health Organization in March *** hyperinflammatory response to the entry of SARS-CoV-2 into the host through angiotensin-converting enzyme 2 is the result of a“cytokine storm”and the high oxidative stress responsible for the associated *** only respiratory symptoms are reported,but gastrointestinal symptoms(diarrhea,vomiting,and nausea)and liver abnormalities(high levels of aspartate aminotransferase,alanine aminotransferase transaminases,and bilirubin)are observed in at least 30%of *** food intake and a delay in medical services may lead to malnutrition,which increases mortality and poor *** review provides some strategies to identify malnutrition and establishes nutritional approaches for the management of COVID-19 and liver injury,taking energy and nutrient requirements and their impact on the immune response into *** roles of certain phytochemicals in the prevention of the disease or as promising target drugs in the treatment of this disease are also considered.

关键词： COVID-19 Infection Liver Nutrition therapy Phytochemicals