A dynamic free energy hysteresis model in magnetostrictive actuators is presented. It is the free energy hysteresis model coupled to an ordinary different equation in an unusual way. According to its special structure...A dynamic free energy hysteresis model in magnetostrictive actuators is presented. It is the free energy hysteresis model coupled to an ordinary different equation in an unusual way. According to its special structure, numerical implementation method of the dynamic model is provided. The resistor parameter in the dynamic model changes according to different frequency ranges. This makes numerical implementation results reasonable in the discussed operating frequency range. The validity of the dynamic free energy model is illustrated by comparison with experimental data.展开更多
Dynamical behaviors and stability properties of a flat space Friedmann-Robertson-Walker universe filled with pressureless dark matter and viscous dark energy are studied in the context of standard classical and loop q...Dynamical behaviors and stability properties of a flat space Friedmann-Robertson-Walker universe filled with pressureless dark matter and viscous dark energy are studied in the context of standard classical and loop quantum cosmology. Assuming that the dark energy has a constant bulk viscosity, it is found that the bulk viscosity effects influence only the quintessence model case leading to the existence of a viscous late time attractor solution of de- Sitter type, whereas the quantum geometry effects influence the phantom model case where the big rip singularity is removed. Moreover, our results of the Hubble parameter as a function of the redshift are in good agreement with the more recent data.展开更多
We propose a computational model to study the growth and spread of bacterial biofilms on interfaces,as well as the action of antibiotics on them.Bacterial membranes are represented by boundaries immersed in a fluid ...We propose a computational model to study the growth and spread of bacterial biofilms on interfaces,as well as the action of antibiotics on them.Bacterial membranes are represented by boundaries immersed in a fluid matrix and subject to interaction forces.Growth,division and death of bacterial cells follow dynamic energy budget rules,in response to variations in environmental concentrations of nutrients,toxicants and substances released by the cells.In this way,we create,destroy and enlarge boundaries,either spherical or rod-like.Appropriate forces represent details of the interaction between cells,and the interaction with the environment.We can investigate geometrical arrangements and the formation of porous structures.Numerical simulations illustrate the evolution of top views and diametral slices of small biofilm seeds,as well as the action of antibiotics.We show that cocktails of antibiotics targeting active and dormant cells can entirely eradicate a biofilm.展开更多
文摘A dynamic free energy hysteresis model in magnetostrictive actuators is presented. It is the free energy hysteresis model coupled to an ordinary different equation in an unusual way. According to its special structure, numerical implementation method of the dynamic model is provided. The resistor parameter in the dynamic model changes according to different frequency ranges. This makes numerical implementation results reasonable in the discussed operating frequency range. The validity of the dynamic free energy model is illustrated by comparison with experimental data.
基金Supported by the Algerian Ministry of Education and ResearchDGRSDT
文摘Dynamical behaviors and stability properties of a flat space Friedmann-Robertson-Walker universe filled with pressureless dark matter and viscous dark energy are studied in the context of standard classical and loop quantum cosmology. Assuming that the dark energy has a constant bulk viscosity, it is found that the bulk viscosity effects influence only the quintessence model case leading to the existence of a viscous late time attractor solution of de- Sitter type, whereas the quantum geometry effects influence the phantom model case where the big rip singularity is removed. Moreover, our results of the Hubble parameter as a function of the redshift are in good agreement with the more recent data.
基金This research has been partially supported by the FEDER/Ministerio de Ciencia,Innovaci´on y Universidades-Agencia Estatal de Investigacin grants MTM2017-84446-C2-1-R and PID2020-112796RB-C21(AC,RG),by fellowship PRE2018-083807(RG)by the Ministerio de Ciencia,Innovaci´on y Universidades”Salvador de Madariaga”grant PRX18/00112(AC)A.C.thanks R.E.Caflisch for hospitality during a sabbatical stay at the Courant Institute,NYU,and C.S.Peskin for nice discussions and useful suggestions.
文摘We propose a computational model to study the growth and spread of bacterial biofilms on interfaces,as well as the action of antibiotics on them.Bacterial membranes are represented by boundaries immersed in a fluid matrix and subject to interaction forces.Growth,division and death of bacterial cells follow dynamic energy budget rules,in response to variations in environmental concentrations of nutrients,toxicants and substances released by the cells.In this way,we create,destroy and enlarge boundaries,either spherical or rod-like.Appropriate forces represent details of the interaction between cells,and the interaction with the environment.We can investigate geometrical arrangements and the formation of porous structures.Numerical simulations illustrate the evolution of top views and diametral slices of small biofilm seeds,as well as the action of antibiotics.We show that cocktails of antibiotics targeting active and dormant cells can entirely eradicate a biofilm.
