Relevant bibliographies by topics / Forças dissipativas

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Forças dissipativas'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Forças dissipativas"

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Santiago, A. J., and H. Rodrigues. "Efeitos de amortecimento sobre um oscilador X³." Revista Brasileira de Ensino de Física 27, no. 2 (2005): 245–49. http://dx.doi.org/10.1590/s1806-11172005000200010.

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Discutimos um método bastante simples de se introduzir o estudo do oscilador x³ amortecido, tanto teórica como experimentalmente, em cursos elementares de Física. Dados experimentais do deslocamento de um oscilador x³ em função do tempo, obtidos em medidas de ultrasom, são bem reproduzidos quando forças dissipativas são levadas em conta através de um único parâmetro.
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De Jesus, A. D. C. "Análise Algébrica de Transferências Orbitais Sujeitas a Desvios Superpostos em "Pitch" e "Yaw"." Sitientibus Série Ciências Físicas 1 (December 20, 2005): 39. http://dx.doi.org/10.13102/sscf.v1i0.5252.

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Os efeitos de desvios em direção do vetor empuxo em manobras de transferência orbital de um veículo espacial podem gerar desalinhamentos definitivos, afastando-o da sua trajetória final nominal. Manobras de correção são implementadas, mas estes desvios tendem a aumentar durante o tempo de vida do veículo pelo desgaste do sistema propulsor. As manobras de correção, neste período, não conseguem alcançar seus objetivos e o veículo é perdido, devido as forças dissipativas e os desvios do sistema propulsor. O entendimento de como estes desvios interferem na órbita final é de grande importância para o controle de uma missão sujeita a desvios em "pitch" e "yaw". Neste trabalho, mostramos a relação algébrica e existente entre os desvios nestes ângulos e seus efeitos em elementos keplerianos importantes que definem a órbita final do veículo. Esta análise permite o estabelecimento teórico e exato entre os valores médios destas grandezas numa relação de causa e efeito não-linear, que prevê os casos de superposição dos efeitos na direção de queima nos propulsores. Os efeitos das forças dissipativas foram considerados desprezíveis em relação aos efeitos destes desvios durante a manobra de transferência orbital.
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Souza, Carlos Eduardo Rodrigues, Maria Teresa Climaco dos Santos Thomaz, and Dácio M. Souza. "Conservação da velocidade do CM de duas partículas sob a ação de forças de atrito em movimento unidimensional (D = 1)." Caderno Brasileiro de Ensino de Física 36, no. 2 (2019): 543–66. http://dx.doi.org/10.5007/2175-7941.2019v36n2p543.

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A força de atrito está presente no cotidiano dos alunos e a compreensão de sua ação sobre os corpos aproxima a Ciência de sua experiência. A lei de conservação do momento linear total, envolvendo sistemas de partículas sob a ação de forças dissipativas externas, não é geralmente discutida nos livros-texto de Mecânica Newtoniana utilizados nos ensinos médio e superior, nas instituições de ensino brasileiras. Discutimos neste trabalho o movimento mais simples que duas partículas podem ter: o movimento unidimensional em sentidos opostos, sob a ação de forças de atrito cinético externas. Mostramos que a conservação do momento linear do conjunto formado por essas partículas, sob a ação de duas forças de atrito cinético, ocorre apenas em partes do movimento unidimensional e quando elas se deslocam em sentidos opostos. Aproveitando o grande envolvimento dos alunos com aplicativos em celulares, apresentamos uma montagem experimental que verifica a conservação da velocidade do centro de massa (CM) desses dois corpos. O aparato experimental é simples e de baixo custo, podendo ser facilmente reproduzido em sala de aula como estratégia para estimular os estudantes a trabalharem com ferramentas matemáticas e métodos experimentais, de forma a discutirem situações físicas que incluem as forças de atritos presentes no seu dia a dia.
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Dodu, Roger P. "De la reciprocite des forces dissipatives." Mechanics Research Communications 12, no. 4 (1985): 227–32. http://dx.doi.org/10.1016/0093-6413(85)90062-x.

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Giner, V., M. Sancho, and G. Martínez. "Electromagnetic forces on dissipative dielectric media." American Journal of Physics 63, no. 8 (1995): 749–53. http://dx.doi.org/10.1119/1.18079.

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Brown, George E., Matthew Overby, Zahra Forootaninia, and Rahul Narain. "Accurate dissipative forces in optimization integrators." ACM Transactions on Graphics 37, no. 6 (2019): 1–14. http://dx.doi.org/10.1145/3272127.3275011.

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Baumgarten, Karsten, and Brian P. Tighe. "Viscous forces and bulk viscoelasticity near jamming." Soft Matter 13, no. 45 (2017): 8368–78. http://dx.doi.org/10.1039/c7sm01619k.

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Izvekov, Sergei, and Betsy M. Rice. "On the importance of shear dissipative forces in coarse-grained dynamics of molecular liquids." Physical Chemistry Chemical Physics 17, no. 16 (2015): 10795–804. http://dx.doi.org/10.1039/c4cp06116k.

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In this work we demonstrate from first principles that the shear frictions describing dissipative forces in the direction normal to the vector connecting the coarse-grained (CG) particles in dissipative particle dynamics (DPD) could be dominant for certain real molecular liquids at high-resolution coarse-graining.
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Gupta, Anurag, and Xanthippi Markenscoff. "Configurational forces as dissipative mechanisms: a revisit." Comptes Rendus Mécanique 336, no. 1-2 (2008): 126–31. http://dx.doi.org/10.1016/j.crme.2007.11.004.

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Calabrese, Allegra, Djamal Gacemi, Mathieu Jeannin, et al. "Coulomb forces in THz electromechanical meta-atoms." Nanophotonics 8, no. 12 (2019): 2269–77. http://dx.doi.org/10.1515/nanoph-2019-0314.

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AbstractThanks to their large sensitivity to electromagnetic fields, microelectromechanical systems are becoming attractive for applications in the THz band (0.1–10 THz). However, up to date all THz electromechanical systems couple electromagnetic fields to mechanical motion only through photothermal dissipative forces: such mechanism allows for sensitive detection but prevents applications that require coherent transfer of information. In this work, we present a THz electromechanical meta-atom where the coupling between an electromagnetic mode and the displacement of a metallic micro-beam is substantially controlled by a conservative Coulomb force due to charge oscillations in the nanometric-size capacitive part of the meta-atom. We present experiments, performed at room temperature, which allow distinguishing and precisely quantifying the contributions of conservative and dissipative forces in the operation of our electromechanical resonator. Our analysis shows that the Coulomb force becomes the dominant contribution of the total driving force for high-order mechanical modes. Such system paves the way for the realization of coherent THz to optical transducers and allows the realization of fundamental optomechanical systems in the THz frequency range.
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Dissertations / Theses on the topic "Forças dissipativas"

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Madeira, Gustavo Oliveira. "Estudo da evolução orbital de partículas em ressonância de corrotação e Lindblad e sob influência de satélites coorbitais : aplicação aos arcos planetários /." Guaratinguetá, 2019. http://hdl.handle.net/11449/180953.

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Orientador: Silvia Maria Giuliatti Winter<br>Resumo: Orbitando Saturno encontram-se Anthe, Methone e Aegaeon, três pequenos satélites coorbitais a arcos planetários e em ressonância de corrotação excêntrica com o satélite Mimas, do tipo 10:11 para o arco de Anthe, 14:15 para o arco de Methone e do tipo 7:6 para o arco do anel G (arco coorbital ao satélite Aegaeon). Neste trabalho é estudada a dinâmica de partículas micrométricas em ressonância de corrotação excêntrica, sob o efeito de forças perturbadoras (força de radiação solar e arrasto do plasma) e da influência gravitacional de pequenos satélites. A ressonância de corrotação excêntrica m + 1:m é responsável por criar m sítios nos quais as partículas permanecem azimutalmente confinadas. Quando incluídos satélites hipotéticos nos sítios, as partículas rapidamente colidem como estes, de modo que os sítios ficam vazios em algumas centenas de anos. Ainda foi constatado que existe uma correlação entre o tempo de vida das partículas com o tamanho físico do satélite, sendo verificado um aumento do tempo de vida dos sítios com o raio do satélite, para satélites com raios da ordem de metros, passando a decrescer para satélites com raios da ordem de quilômetros. Tal resultado se deve ao fato dos satélites pequenos tenderem a apenas perturbar a órbita das partículas, as quais realizam maiores excursões em relação ao centro do sítio, enquanto satélites maiores confinam as partículas azimutalmente, de modo que estas permanecem em ressonância de corrotação com Mimas e com o satélite. Efe... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Anthe, Methone and Aegaeon are three tiny saturnian moons. They are coorbital to planetary arcs and are trapped in corotation eccentric resonances with Mimas: 10:11 Anthe’s arc, 14:15 Methone’s arc and 7:6 G ring arc (Aegaeon’s arc). In this work we studied the dynamics of the particles trapped in the corotation eccentric resonances under the effects of dissipative forces (solar radiation force and plasma drag) and coorbitals moonlets. The m + 1:m corotation eccentric resonance creates m sites where the particles will be azimuthally confined for more than 100 thousand years. When satellites are located in the sites, the particles quickly collide with them and these sites are cleaned in a few hundred years. We verified an increase in the lifetime of the sites with the satellites’ radii, for moons with radius of the order of meters, and a decrease in the lifetime with an increase of the satellites’ radii, for kilometer-sized satellites. Satellites with radii of the order of meters only disturb the particles’ orbits, so the particles perform large excursions in relation to the site’s center. Satellites with kilometric radii azimuthally confine the particles, wich remain in resonance with Mimas and with the coorbital satellite. The solar radiation force and plasma drag effects on the semimajor axis remove particles from the azimuthal confinement and the effects on the eccentricity favor collisions with the satellites. The sites of the 7:6, 14:15 and 10:11 corotation resonance, if... (Complete abstract click electronic access below)<br>Mestre
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Santos, Lucas Ruiz dos. "Efeitos dissipativos em mecânica celeste modelados por corpos pseudo-rígidos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/45/45132/tde-23082016-155031/.

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O presente trabalho dedica-se a uma modelagem da interação entre corpos celestes, em regime Newtoniano, levando-se em consideração as influências que suas deformações e viscosidades internas exercem sobre seus movimentos orbitais e suas velocidades angulares. A abordagem adotada é uma variação do conhecido problema do corpo pseudo-rígido, a qual simplifica drasticamente a determinação dos equilíbrios relativos e torna a questão da dinâmica matematicamente acessível. Com este tratamento, podemos relacionar ou comparar os resultados com aqueles estabelecidos na literatura, dentre eles: formato de equilíbrio de um fluido isolado em rotação, deformação de maré causada pela interação gravitacional e o torque de maré induzido no mesmo. Pela simplicidade do modelo pode-se ainda fazer uma análise qualitativa da dinâmica do sistema e obter estimativas sobre a velocidade com que se aproxima dos equilíbrios.<br>The present work is devoted to model the interaction among celestial bodies, in a Newtonian regime, but considering the role played by the internal deformation and viscosity on the orbital motion and angular velocities of the components of the system. The work is mainly developed with an alternative approach to the pseudo-rigid body model, which simplifies the determination of the relative equilibria and allows precise conclusions about the dynamics. So, we are able to compare the results of this theory with those established in the literature, namely: the equilibrium shape of an isolated fluid in rotation, the tidal elongation induced by gravitational interaction and the tidal torque. Due to its simplicity, we can further perform a qualitative analysis of the dynamics of the system and estimate the velocity of attraction of the equilibrium states.
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Judge, Elizabeth Eileen. "Direct measurement of dissipative forces in superconducting BSCCO." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035957.

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Baesens, Viviane. "Systèmes dynamiques dissipatifs forcés périodiquement: orbites homoclines, bifurcations globales et chaos." Doctoral thesis, Universite Libre de Bruxelles, 1987. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213445.

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Trément, Sébastien. "Simulations gros grains de systèmes complexes et forces d’interactions : du microscopique au mésoscopique." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112227.

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Un fondu de polymères est un liquide complexe constitué de chaînes macromoléculaires. Ces chaînes présentent la particularité d'offrir une distribution de temps caractéristiques extrêmement importante. L'ensemble de ces différentes échelles représente donc un défi pour la simulation numérique de polymères longs et sont bien au-delà des capacités des ordinateurs actuels. Un thème actuel de recherche porte donc sur le développement de modèles mésoscopiques (modèle gros grains). La construction d'un tel modèle consiste à éliminer les degrés de liberté rapide en regroupant un certain nombre d'atomes en un monomère. Ce monomère est représenté par une sphère molle évoluant dans un bain thermique créé par les degrés de liberté rapides éliminés au cours du processus de nivellement. La dynamique des particules créées est donc stochastique. La dynamique particulaire dissipative qui intègre ces idées est une combinaison de dynamique moléculaire, de Lattice Gas Automata ainsi que de dynamique Brownienne. Le champ de force DPD est constitué d'une interaction molle et d'un thermostat (force dissipative et bruit) et les paramètres de ce champ de force sont généralement calibrés sur des données expérimentales (compressibilité et diffusion). Cette approche est difficilement applicable aux mélanges de polymères. Pour surmonter cette difficulté, l'intégralité du champ de force DPD est construit à partir d'une dynamique moléculaire pour des corps purs ainsi que pour des mélanges. Nous montrons également que pour calculer correctement la force dissipative, la dynamique moléculaire doit être altérée en contraignant la position des monomères. Les coefficients de transport sont calculés par DPD et comparés à ceux obtenus par dynamique moléculaire. Ce travail s'achève par une étude de la transferabilité du champ de force du monomère vers toute une chaîne de polymères<br>A molten polymer is a complex liquid consisting of macromolecular chains. These chains have many different time scales. All these scales present a real challenge to numerical simulations and exceed the computational capabilities of today's computers. A current topic of research therefore focuses on the development of mesoscopic models. The main idea behind coarse-graining is to eliminate fast degrees of freedom grouping atoms or molecules into clusters (or monomers). This monomer is represented by a soft sphere operating in a thermal bath generated by the fast degrees of freedom eliminated during the coarse-graining. Particle dynamics is therfore stochastic. Dissipative particle dyna-mics, which includes these ideas, is a combination of molecular dynamics, Lattice Gas Automata and Brownian dynamics. DPD force field consist of a soft interaction and a thermostat (dissipative and random force) and parameters of DPD interaction are generally optimized to match some macroscopic properties like compressibility or self-diffusion coefficient. This approach is difficult to apply to polymer melt. To overcome this problem, we apply an operational procedure available in the literature to the cons-truction of conservative and dissipative forces of DPD force field for pure substances and mixtures. We also show that in order to calculate the dissipative forces, the underlying molecular dynamics must be altered by constraining the position of the mo-nomers. Transport coefficients are calculated by DPD and compared with those obtained by molecular dynamics. This work concludes with a study of the transferability of the force field of the monomer to a chain of polymers
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Zhong, Jun. "Geometrical Investigation on Escape Dynamics in the Presence of Dissipative and Gyroscopic Forces." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/97363.

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This dissertation presents innovative unified approaches to understand and predict the motion between potential wells. The theoretical-computational framework, based on the tube dynamics, will reveal how the dissipative and gyroscopic forces change the phase space structure that governs the escape (or transition) from potential wells. In higher degree of freedom systems, the motion between potential wells is complicated due to the existence of multiple escape routes usually through an index-1 saddle. Thus, this dissertation firstly studies the local behavior around the index-1 saddle to establish the criteria of escape taking into account the dissipative and gyroscopic forces. In the analysis, an idealized ball rolling on a surface is selected as an example to show the linearized dynamics due to its special interests that the gyroscopic force can be easily introduced by rotating the surface. Based on the linearized dynamics, we find that the boundary of the initial conditions of a given energy for the trajectories that transit from one side of a saddle to the other is a cylinder and ellipsoid in the conservative and dissipative systems, respectively. Compared to the linear systems, it is much more challenging or sometimes impossible to get analytical solutions in the nonlinear systems. Based on the analysis of linearized dynamics, the second goal of this study is developing a bisection method to compute the transition boundary in the nonlinear system using the dynamic snap-through buckling of a buckled beam as an example. Based on the Euler-Bernoulli beam theory, a two degree of freedom Hamiltonian system can be generated via a two mode-shape truncation. The transition boundary on the Poincar'e section at the well can be obtained by the bisection method. The numerical results prove the efficiency of the bisection method and show that the amount of trajectories that escape from the potential well will be smaller if the damping of the system is increasing. Finally, we present an alternative idea to compute the transition boundary of the nonlinear system from the perspective of the invariant manifold. For the conservative systems, the transition boundary of a given energy is the invariant manifold of a periodic orbit. The process of obtaining such invariant manifold compromises two parts, including the computation of the periodic orbit by solving a proper boundary-value problem (BVP) and the globalization of the manifold. For the dissipative systems, however, the transition boundary of a given energy becomes the invariant manifold of an index-1 saddle. We present a BVP approach using the small initial sphere in the stable subspace of the linearized system at one end and the energy at the other end as the boundary conditions. By using these algorithms, we obtain the nonlinear transition tube and transition ellipsoid for the conservative and dissipative systems, respectively, which are topologically the same as the linearized dynamics.<br>Doctor of Philosophy<br>Transition or escape events are very common in daily life, such as the snap-through of plant leaves and the flipping over of umbrellas on a windy day, the capsize of ships and boats on a rough sea. Some other engineering problems related to escape, such as the collapse of arch bridges subjected to seismic load and moving trucks, and the escape and recapture of the spacecraft, are also widely known. At first glance, these problems seem to be irrelated. However, from the perspective of mechanics, they have the same physical principle which essentially can be considered as the escape from the potential wells. A more specific exemplary representative is a rolling ball on a multi-well surface where the potential energy is from gravity. The purpose of this dissertation is to develop a theoretical-computational framework to understand how a transition event can occur if a certain energy is applied to the system. For a multi-well system, the potential wells are usually connected by saddle points so that the motion between the wells generally occurs around the saddle. Thus, knowing the local behavior around the saddle plays a vital role in understanding the global motion of the nonlinear system. The first topic aims to study the linearized dynamics around the saddle. In this study, an idealized ball rolling on both stationary and rotating surfaces will be used to reveal the dynamics. The effect of the gyroscopic force induced by the rotation of the surface and the energy dissipation will be considered. In the second work, the escape dynamics will be extended to the nonlinear system applied to the snap-through of a buckled beam. Due to the nonlinear behavior existing in the system, it is hard to get the analytical solutions so that numerical algorithms are needed. In this study, a bisection method is developed to search the transition boundary. By using such method, the transition boundary on a specific Poincar'e section is obtained for both the conservative and dissipative systems. Finally, we revisit the escape dynamics in the snap-through buckling from the perspective of the invariant manifold. The treatment for the conservative and dissipative systems is different. In the conservative system, we compute the invariant manifold of a periodic orbit, while in the dissipative system we compute the invariant manifold of a saddle point. The computational process for the conservative system consists of the computation of the periodic orbit and the globalization of the corresponding manifold. In the dissipative system, the invariant manifold can be found by solving a proper boundary-value problem. Based on these algorithms, the nonlinear transition tube and transition ellipsoid in the phase space can be obtained for the conservative and dissipative systems, respectively, which are qualitatively the same as the linearized dynamics.
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Graille, Benjamin. "Modélisation de mélanges gazeux réactifs ionisés dissipatifs." Phd thesis, Ecole Polytechnique X, 2004. http://tel.archives-ouvertes.fr/tel-00007444.

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Nous élaborons des modèles macroscopiques d'EDP pour les mélanges gazeux réactifs ionisés et nous effectuons diverses études mathématiques puis quelques simulations numériques. On détermine les équations macroscopiques ainsi que des expressions des flux de<br />transport à partir d'un modèle de type Boltzmann par un développement de Enskog. Nous étudions alors les propriétés de symétrie apportées par l'entropie de ces équations couplées avec celles de Maxwell pour obtenir un théorème d'existence locale en temps d'une solution bornée et régulière pour le problème de Cauchy. Nous étudions ensuite un modèle de plasma ambipolaire en considérant la masse de l'électron comme un paramètre. Nous démontrons que la solution globale dépend continument de la masse de l'électron lorsque celle-ci s'annule. Nous calculons enfin des flammes ionisées planes et étirées d'un mélange hydrogène-air et obtenons des structures de flammes typiques avec un faible impact de l'ionisation.
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Bastardie, Eric. "Codage de contours et interprétation d'images par des arcs de cercle : application à la mise au point d'un système d'analyse automatique d'images de structures spatiales chimiques." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10584.

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Ibergay, Cyrille. "Simulation mésoscopique de polyélectrolytes aux interfaces." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00724510.

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Une brosse de polyélectrolytes est constituée par des chaînes de polymères chargées greffées sur une surface. Le but de cette thèse est d'étudier par simulation mésoscopique (dynamique des particules dissipatives, DPD) les facteurs qui influencent les propriétés rhéologiques du système. Les interactions électrostatiques ont été incorporées dans la version initiale de la méthode DPD selon deux techniques (Ewald et PPPM). Les dépendances de la hauteur de brosse en fonction de la fraction de charge, de la densité de greffage et de la concentration en sels, calculées par la méthode DPD, suivent le régime de brosse osmotique non linéaire. L'interaction entre deux brosses en interaction a également été modélisée dans l'ensemble Grand Canonique. Les simulations ont démontré que l'interpénétration entre les deux brosses en interaction diminuent avec la fraction de charge. L'étude de ce système sous cisaillement a permis de démontrer que les forces de friction de brosses polyélectrolytes étaient inférieures à celles de brosses neutres à partir d'une certaine distance de séparation entre les deux surfaces greffées.
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Seitz, Peter C. [Verfasser]. "The physical role of lipopolymers in the modulation of interfacial forces and dissipative pattern formation in biomembrane models / put forward by Peter C. Seitz." 2010. http://d-nb.info/999719580/34.

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Books on the topic "Forças dissipativas"

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Milonni, Peter W. An Introduction to Quantum Optics and Quantum Fluctuations. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780199215614.001.0001.

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This book is an introduction to quantum optics for students who have studied electromagnetism and quantum mechanics at an advanced undergraduate or graduate level. It provides detailed expositions of theory with emphasis on general physical principles. Foundational topics in classical and quantum electrodynamics, including the semiclassical theory of atom-field interactions, the quantization of the electromagnetic field in dispersive and dissipative media, uncertainty relations, and spontaneous emission, are addressed in the first half of the book. The second half begins with a chapter on the Jaynes-Cummings model, dressed states, and some distinctly quantum-mechanical features of atom-field interactions, and includes discussion of entanglement, the no-cloning theorem, von Neumann’s proof concerning hidden variable theories, Bell’s theorem, and tests of Bell inequalities. The last two chapters focus on quantum fluctuations and fluctuation-dissipation relations, beginning with Brownian motion, the Fokker-Planck equation, and classical and quantum Langevin equations. Detailed calculations are presented for the laser linewidth, spontaneous emission noise, photon statistics of linear amplifiers and attenuators, and other phenomena. Van der Waals interactions, Casimir forces, the Lifshitz theory of molecular forces between macroscopic media, and the many-body theory of such forces based on dyadic Green functions are analyzed from the perspective of Langevin noise, vacuum field fluctuations, and zero-point energy. There are numerous historical sidelights throughout the book, and approximately seventy exercises.
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Book chapters on the topic "Forças dissipativas"

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Vulfson, Iosif. "Nonlinear Dissipative Forces." In Foundations of Engineering Mechanics. Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-12634-0_6.

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Jancart, Sylvie, and Anne Lemaitre. "Dissipative Forces and External Resonances." In Dynamics of Natural and Artificial Celestial Bodies. Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-017-1327-6_9.

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Corral, Eduardo, Filipe Marques, María Jesús Gómez García, Paulo Flores, and Juan Carlos García-Prada. "Passive Walking Biped Model with Dissipative Contact and Friction Forces." In EuCoMeS 2018. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-98020-1_5.

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Minty, Michiko G., and Frank Zimmermann. "Cooling." In Particle Acceleration and Detection. Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-662-08581-3_11.

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AbstractMany applications of particle accelerators require beam cooling, which refers to a reduction of the beam phase space volume or an increase in the beam density via dissipative forces. In electron and positron storage rings cooling naturally occurs due to synchrotron radiation, and special synchrotron-radiation damping rings for the production of low-emittance beams are an integral part of electron-positron linear colliders. For other types of particles different cooling techniques are available. Electron cooling and stochastic cooling of hadron beams are used to accumulate beams of rare particles (such as antiprotons), to combat emittance growth (e.g., due to scattering on an internal target), or to produce beams of high quality for certain experiments. Laser cooling is employed to cool ion beams down to extremely small temperatures. Here the laser is used to induce transitions between the ion electronic states and the cooling exploits the Dopper frequency shift. Electron beams of unprecedentedly small emittance may be obtained by a different type of laser cooling, where the laser beam acts like a wiggler magnet. Finally, designs of a future muon collider rely on the principle of ionization cooling. Reference [1] gives a brief review of the principal ideas and the history of beam cooling in storage rings; a theoretical dicussion and a few practical examples can be found in [2].
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Milonni, Peter W. "Dipole Interactions and Fluctuation-Induced Forces." In An Introduction to Quantum Optics and Quantum Fluctuations. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780199215614.003.0007.

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Concepts considered in earlier chapters, especially vacuum field fluctuations and zero-point energy, are applied to van der Waals, Casimir, and dipole-dipole resonance interactions, and to field quantization in dissipative dielectric media. Detailed but physically motivated calculations are presented regarding the Lifshitz theory, Casimir and Casimir-Polder forces, and the many-body theory of van der Waals and Casimir interactions based on dyadic Green functions. Expressions for quantized fields in dispersive and dissipative media are derived straightforwardly from Langevin noise theory, and it is shown how this approach is related to the more complicated Fano diagonalization method. Zero-point field energy in dissipative media and its role in Casimir and other effects is discussed in relation to other physical interpretations. Other topics discussed are (Forster) fluorescence resonance energy transfer and the modification of spontaneous emission rates by reflectors and host dielectric media.
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"Dissipative Forces Derived from Many-Body Problems." In Classical and Quantum Dissipative Systems. WORLD SCIENTIFIC, 2017. http://dx.doi.org/10.1142/9789813207929_0008.

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"Dissipative Forces Derived from Many-Body Problems." In Classical and Quantum Dissipative Systems. PUBLISHED BY IMPERIAL COLLEGE PRESS AND DISTRIBUTED BY WORLD SCIENTIFIC PUBLISHING CO., 2006. http://dx.doi.org/10.1142/9781860949180_0008.

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Nassar, Paula Rodrigues, Jonathas Barreto, and Alexandre Schiavetti. "PROJEÇÕES PARA OS EFEITOS DO AUMENTO DO NÍVEL DO MAR NO SUCESSO REPRODUTIVO DE TARTARUGAS MARINHAS NO BRASIL." In Pesquisa e Aplicação em Ciências Biológicas. Bookerfield Editora, 2021. http://dx.doi.org/10.53268/bkf21060509.

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As mudanças climáticas já estão ocorrendo globalmente e a forma com que gestores e cidadãos irão responder a essas mudanças dependerá da rapidez das ações em contê-las e principalmente o conhecimento sobre o assunto. As tartarugas marinhas podem ser consideradas espécies sentinelas, como um indicador da saúde dos oceanos e do meio ambiente. Um dos impactos das mudanças climáticas sob as populações de tartarugas marinhas é a perda de praia de desova frente à elevação do nível do mar. Para isso, este estudo projetou possíveis perdas de área de desovas de três espécies de tartarugas marinhas (Caretta caretta, Eretmochelys imbricata e Dermochelys coriacea) em quatro áreas reprodutivas do litoral brasileiro. Foram coletadas variáveis ambientais das praias e dos ninhos. Ninhos na zona de vegetação e com altas taxas de eclosão podem indicar um sucesso reprodutivo dessas espécies em áreas mais distantes da maré, caso seja necessário a redistribuição espacial dos ninhos. Notouse que praia de perfil dissipativo seria o tipo de perfil mais prejudicado pela elevação do nível do mar, e no presente estudo, apenas E. imbricata apresentou desovas regulares na praia com essa morfodinâmica. Praias de perfil intermediário, nas quais foram observadas ninhos das três espécies, estariam sujeitas a impactos diferentes em cada projeção, dependentes principalmente da largura e da declividade da praia.
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Conference papers on the topic "Forças dissipativas"

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Zheng, Yi, and Arvind Narayanaswamy. "A First-Principles Method of Determining Van Der Waals Forces in a Dissipative Media." In ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75165.

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Lifshitz theory of van der Waals (vdW) force and energy is strictly valid when the location at which the stress tensor is calculated is in vacuum. Generalization of Lifshitz theory to the case when the stress tensor is to be calculated in a dissipative material, as opposed to vacuum, is a surprisingly difficult undertaking because there is no expression for the electromagnetic stress tensor in dissipative materials. Here, we derive the expression for vdW force in planar dissipative media by calculating the Maxwell stress tensor in a fictious layer of vacuum, that is eventually made to vanish, introduced in the structure, without employing the complicated quantum field theoretic method proposed by Dzyaloshinskii, Lifshitz, and Pitaevskii. Even though this work has proven to be a corroboration of Dzyaloshinskii et al., it has thrown new light on our understanding of vdW forces and suggests that it should be possible to achieve the similar result for objects with arbitrary shapes.
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Goun, A. A., and O. K. Sliva. "Time Optimal Transfer Function of a Mechanism in the Presence of Dissipative Forces." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61907.

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A variety of optimization problems in theoretical mechanics are related to the problem of finding the quickest operating mechanism among all possible mechanisms. Let us consider a mechanical system with one degree of freedom consisting of leading and lagging links with masses M1 and M2 respectively. Source of mechanical energy is attached to the leading link and its potential energy is known as a function of the position of the leading link. Positions of the leading - x and lagging links - y are related through the position function. Now the optimization problem can be formulated in the following way: find the position function such that the lagging link is transferred from initial to the final position in the shortest time. The analytic solution for this problem for the case when dissipative forces can be neglected was found using variational calculus method. In the case when dissipative forces can be described as viscous friction the problem can be solved using iterative methods. The differential equation that describes the stationary point of these iterations was obtained. The dependence of the optimal position function on the magnitude of friction is analyzed. In the case when dissipative forces are of the dry friction type the approach based on the variational calculus fails. We were able to find the optimal position function problem using Maximum Principle. New qualitative features of the solution arising due to dry friction are discussed. Approaches developed in this paper can be generalized for a variety of mechanisms where the operating time is critical.
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Cheriyan, Sony, Paulo Flores, and Hamid M. Lankarani. "Computational and Experimental Analysis of Mechanical Systems With Revolute Clearance Joints." In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-12595.

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The main objective of this work is to present a computational and experimental study on the contact forces developed in revolute clearance joints. For this purpose, a well-known slider-crank mechanism with a revolute clearance joint between the connecting rod and slider is utilized. The intra-joint contact forces that generated at this clearance joints are computed by considered several different elastic and dissipative approaches, namely those based on the Hertz contact theory and the ESDU tribology-based for cylindrical contacts, along with a hysteresis-type dissipative damping. The normal contact force is augmented with the dry Coulomb’s friction force. An experimental apparatus is use to obtained some experimental data in order to verify and validate the computational models. From the outcomes reported in this paper, it is concluded that the selection of the appropriate contact force model with proper dissipative damping plays a significant role in the dynamic response of mechanical systems involving contact events at low or moderate impact velocities.
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Spaggiari, Andrea, Igor Spinella, and Eugenio Dragoni. "Design Equations for Binary Shape Memory Actuators Under Arbitrary External Forces." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-4999.

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The paper presents the design equations for an on-off shape memory alloy actuator under an arbitrary system of external constant forces. A binary SMA actuator is considered where a cursor is moved against both conservative and dissipative force which may be different during the push or pull phase. Three cases are analyzed and differentiated in the way the bias force is applied to the primary SMA spring, using a constant force, a traditional spring, or a second SMA spring. Closed-form dimensionless design equations are developed, which form the basis of a step-by-step procedure for an optimal design of the whole actuator.
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Donaire, Alejandro, Romeo Ortega, and Jose Guadalupe Romero. "Simultaneous interconnection and damping assignment passivity-based control of mechanical systems using dissipative forces." In 2016 American Control Conference (ACC). IEEE, 2016. http://dx.doi.org/10.1109/acc.2016.7526711.

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Satoh, Akira. "Comparison Between Theoretical Values and Simulation Results of Transport Coefficients for the Dissipative Particle Dynamics Method." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56065.

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In the present study, we have derived an expression for transport coefficients such as viscosity, from the equation of motion of dissipative particles. In the concrete, we have shown the Fokker-Planck equation in phase space, and macroscopic conservation equations such as the equation of continuity and the equation of momentum conservation. The basic equations of the single-particle and pair distribution functions have been derived using the Fokker-Planck equation. The solutions of these distribution functions have approximately been solved by the perturbation method under the assumption of molecular chaos. The expression of the viscosity due to dissipative forces has been obtained using the approximate solutions of the distribution functions. Also, we have conducted non-equilibrium dynamics simulations to investigate the influence of the parameters, which have appeared in defining the equation of motion in the dissipative particle dynamics method.
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Czerwinska, Justyna, and Nikolaus A. Adams. "Numerical Modeling of Micro-Channel Flows by a DPD Method." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45127.

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This paper proposes new computational technique to model micro-flows. The presented below method is based on the meso-scale description of fluid. Dissipative Particle Dynamics (DPD) method is derived from Molecular Dynamics by means of coarse graining procedure. The dissipative particle is defined as a Voronoi cell with variable mass and size; evolves similarly to the Molecular Dynamics particles, except that inter-particle forces have additionally fluctuating, dissipative and stochastic component. This representation leads to the set of equations describing DPD approach. In this paper the outline of the DPD method for application to micro-fluidics flow is presented. DPD method in the form of Soft Fluid Particle model, was mainly applied in material science simulation. This paper presents new approach to model micro-flow by Voronoi Particle DPD method. As a particular example the gas flow in micro-channel flow is computed.
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Bauchau, Olivier A. "A Self-Stabilized Algorithm for Enforcing Constraints in Multibody Systems." In ASME 2003 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/detc2003/vib-48332.

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A new algorithm is developed for the enforcement of constraints within the framework of nonlinear, flexible multibody system modeled with the finite element approach. The proposed algorithm exactly satisfies the constraints at the displacement and velocity levels, and furthermore, it achieves nonlinear unconditional stability by imposing the vanishing of the work done by the constraint forces when combined with specific discretizations of the inertial and elastic forces. Identical convergence rates are observed for the displacements, velocities, and Lagrange multipliers. The proposed algorithm is closely related to the stabilized index-2 or GGL method, although no additional multipliers are introduced in the present approach. These desirable characteristics are obtained without resorting to numerically dissipative algorithms. If high frequencies are present in the system, i.e. the system +is physically stiff, dissipative schemes become necessary; the proposed algorithm is extended to deal with this situation.
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Joulaian, Meysam, Sorush Khajepor, Ahmadreza Pishevar, and Yaser Afshar. "Dissipative Particle Dynamics Simulation of Nano Taylor Cone." In ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels collocated with 3rd Joint US-European Fluids Engineering Summer Meeting. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-31089.

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Dissipative particle dynamics (DPD) is an emerging method for simulating problems at mesoscopic time and length scales. In this paper, we present a new algorithm to describe the hydrodynamics of a perfect conductive fluid in the presence of an electric field. The model is based on solving the electrostatic equations in each DPD time step for determining the charge distribution at the fluid interface and, therefore, corresponding electrical forces exerted by the electric field to the particles near the interface. The method is applied to a perfect conductive pendant drop which is immersed in a perfect dielectric and hydrodynamically inactive ambient. We have shown that when the applied voltage is sufficiently high, the drop shape is changed to a cone with an apex angle which is near to the Taylor analytical estimation of 98.6°. Our results reveal that the presented algorithm gives new capabilities to the conventional DPD method for simulating nanoscale problems in the presence of an electric field.
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Dear, Tony, Scott David Kelly, Matthew Travers, and Howie Choset. "Dissipation-Induced Self-Recovery in Systems on Principal Bundles." In ASME 2014 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/dscc2014-6212.

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The “self-recovery” phenomenon is a seemingly curious property of certain underactuated dissipative systems in which dissipative forces always push the system to a pre-determined equilibrium state dependent on the initial conditions. The systems for which this has been studied are Abelian, with all system velocity interactions due entirely to inertial effects. In this paper we also consider Abelian systems, but in the context of principal bundles, and introduce drag in addition to inertial interactions, allowing us to show that the same conservation that induces self-recovery now depends on the trajectories of the system inputs in addition to initial conditions. We conclude by demonstrating an example illustrating the conditions derived from our proof, along with an observation that the present analysis is insufficient for self-recovery in non-Abelian systems.
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