The present work reports the analysis of the intramolecular OH stretching band obtained by InfraRed spectroscopy measurements. In order to characterize the effect of trehalose on the hydration properties of lysozyme the so-called two-state model is adopted for the analysis of the intramolecular OH stretching band. This latter assumes that, provided that the trehalose OH stretching contribution is subtracted, water molecules can be partitioned into two different states of inter-molecular bonding: molecules with two OH groups both hydrogen-bonded within a tetrahedral network, and molecules with one or two dangling OH groups. What emerges from this study is that trehalose significantly influences the hydrogen bond network of water and its temperature behaviour. Such a result confirms that the trehalose induced strengthening of the hydrogen-bond network leads to a stabilization of the lysozyme structure. Moreover, the analysis of the spectra temperature dependence shows a trehalose-induced higher thermal restraint of the lysozyme-trehalose-water system in respect to the lysozyme-water mixture.
{"title":"Intramolecular OH stretching analysis of hydrated lysozyme in presence of trehalose by IR spectroscopy","authors":"M. T. Caccamo, S. Magazù","doi":"10.1478/AAPP.97S1A2","DOIUrl":"https://doi.org/10.1478/AAPP.97S1A2","url":null,"abstract":"The present work reports the analysis of the intramolecular OH stretching band obtained by InfraRed spectroscopy measurements. In order to characterize the effect of trehalose on the hydration properties of lysozyme the so-called two-state model is adopted for the analysis of the intramolecular OH stretching band. This latter assumes that, provided that the trehalose OH stretching contribution is subtracted, water molecules can be partitioned into two different states of inter-molecular bonding: molecules with two OH groups both hydrogen-bonded within a tetrahedral network, and molecules with one or two dangling OH groups. What emerges from this study is that trehalose significantly influences the hydrogen bond network of water and its temperature behaviour. Such a result confirms that the trehalose induced strengthening of the hydrogen-bond network leads to a stabilization of the lysozyme structure. Moreover, the analysis of the spectra temperature dependence shows a trehalose-induced higher thermal restraint of the lysozyme-trehalose-water system in respect to the lysozyme-water mixture.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44937169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present a synthesis of recent results on thermal heat conductivity in nano-composites and nano-structures. The model is a mixt of the Effective Medium Approximation (EMA) and Extended Irreversible Thermodynamics (EXIT). The latter is particularly well adapted to the description of small scaled systems and will be used to derive the expression of the thermal conductivity of nanoparticles. The model is applied to spherical, cylindrical (nanowires) and porous nanoparticles, respectively, being embedded in host media, like polymeric matrices and semi-conductors. Good agreement is observed with other models, experimental data and Monte-Carlo simulations.
{"title":"Effective thermal conductivity of nanostructures: a review","authors":"G. Lebon, H. Machrafi","doi":"10.1478/AAPP.97S1A14","DOIUrl":"https://doi.org/10.1478/AAPP.97S1A14","url":null,"abstract":"We present a synthesis of recent results on thermal heat conductivity in nano-composites and nano-structures. The model is a mixt of the Effective Medium Approximation (EMA) and Extended Irreversible Thermodynamics (EXIT). The latter is particularly well adapted to the description of small scaled systems and will be used to derive the expression of the thermal conductivity of nanoparticles. The model is applied to spherical, cylindrical (nanowires) and porous nanoparticles, respectively, being embedded in host media, like polymeric matrices and semi-conductors. Good agreement is observed with other models, experimental data and Monte-Carlo simulations.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41707843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper deals with viscoelastic solids subject to aging and fatigue effects. First a scheme is set up on the basis of physical insights, provided by the analysis of a rheological model, by letting the elastic moduli and the viscosity coefficients be functions of time. Hence the functional providing the stress in terms of the strain is established. The procedure has the advantage of showing how the dependence on the present value and that on the history of the strain are influenced by the rheological parameters. The three-dimensional version is then considered and the thermodynamic restrictions are determined. Next a second approach is set up by letting the stress be given by a constitutive equation involving a fractional derivative. The coefficient characterizing the kernel is assumed to obey an evolution equation that incorporates the fatigue effects. Compatibility with thermodynamics is shown to hold with an appropriate internal structural power.
{"title":"Two approaches to aging and fatigue models in viscoelastic solids","authors":"M. Fabrizio, C. Giorgi, A. Morro","doi":"10.1478/AAPP.97S1A7","DOIUrl":"https://doi.org/10.1478/AAPP.97S1A7","url":null,"abstract":"The paper deals with viscoelastic solids subject to aging and fatigue effects. First a scheme is set up on the basis of physical insights, provided by the analysis of a rheological model, by letting the elastic moduli and the viscosity coefficients be functions of time. Hence the functional providing the stress in terms of the strain is established. The procedure has the advantage of showing how the dependence on the present value and that on the history of the strain are influenced by the rheological parameters. The three-dimensional version is then considered and the thermodynamic restrictions are determined. Next a second approach is set up by letting the stress be given by a constitutive equation involving a fractional derivative. The coefficient characterizing the kernel is assumed to obey an evolution equation that incorporates the fatigue effects. Compatibility with thermodynamics is shown to hold with an appropriate internal structural power.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48201323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Generally understood ferroic media have been investigated by many authors. The majority of them have dealt with the electromagnetic nature of the domain structure of crystalline or amorphous solids. However, there exist also materials that have an internal ordered structure from the mechanical (elastic) point of view. They are called ferroelastics. The presentation proposes a thermomechanical model of irreversible and nonequilibrium processes that can run in continuous multiferroic media in which simultaneous interactions of various physical fields occur both in low and room temperatures. Attempts concerning a proposition of the constitutive theory resulting from linear and nonlinear forms of the free energy density are also presented.
{"title":"Thermomechanics of multiferroics","authors":"B. Maruszewski","doi":"10.1478/AAPP.97S1A15","DOIUrl":"https://doi.org/10.1478/AAPP.97S1A15","url":null,"abstract":"Generally understood ferroic media have been investigated by many authors. The majority of them have dealt with the electromagnetic nature of the domain structure of crystalline or amorphous solids. However, there exist also materials that have an internal ordered structure from the mechanical (elastic) point of view. They are called ferroelastics. The presentation proposes a thermomechanical model of irreversible and nonequilibrium processes that can run in continuous multiferroic media in which simultaneous interactions of various physical fields occur both in low and room temperatures. Attempts concerning a proposition of the constitutive theory resulting from linear and nonlinear forms of the free energy density are also presented.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42074069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper we go ahead in our studies on refrigeration of nanosystems by superfluid helium, as an appealing subject for future applications to computers or astronautical precision nanodevices. We first recall the effective thermal conductivity in laminar counterflow superfluid helium through arrays of mutually parallel cylinders and we discuss the conditions for the appearance of quantum turbulence around the heat-producing cylinders. We then consider the cooling of an array of heat-producing cylindrical nanosystems by means of superfluid-helium counterflow. We discuss the upper bound on heat removal set by avoidance of quantum turbulence and avoidance of phase transition to normal He I, for arrays of cylinders placed between two infinite insulating plates and with heat flowing in the two dimensions parallel to such plates.
{"title":"Refrigeration bound of heat-producing cylinders by superfluid helium","authors":"D. Jou, M. Sciacca, A. Sellitto, L. Galantucci","doi":"10.1478/AAPP.97S1A12","DOIUrl":"https://doi.org/10.1478/AAPP.97S1A12","url":null,"abstract":"In this paper we go ahead in our studies on refrigeration of nanosystems by superfluid helium, as an appealing subject for future applications to computers or astronautical precision nanodevices. We first recall the effective thermal conductivity in laminar counterflow superfluid helium through arrays of mutually parallel cylinders and we discuss the conditions for the appearance of quantum turbulence around the heat-producing cylinders. We then consider the cooling of an array of heat-producing cylindrical nanosystems by means of superfluid-helium counterflow. We discuss the upper bound on heat removal set by avoidance of quantum turbulence and avoidance of phase transition to normal He I, for arrays of cylinders placed between two infinite insulating plates and with heat flowing in the two dimensions parallel to such plates.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44526519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Preface to the AAPP supplementary issue collecting the proceedings of the international conference on "Thermal theories of continua: Survey and developments" (19-22 April 2016; Messina, Italy).
{"title":"Introducing Thermocon 2016","authors":"D. Jou, L. Restuccia, P. Ván","doi":"10.1478/AAPP.97S1E1","DOIUrl":"https://doi.org/10.1478/AAPP.97S1E1","url":null,"abstract":"Preface to the AAPP supplementary issue collecting the proceedings of the international conference on \"Thermal theories of continua: Survey and developments\" (19-22 April 2016; Messina, Italy).","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44646157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the environment there exists a continuous interaction between electromagnetic radiation and matter. So, atoms continuously interact with the photons of the environmental electromagnetic fields. This electromagnetic interaction is a consequence of thermal non-equilibrium. It introduces an element of randomness into atomic and molecular motion, which leads to the decrease of the path probability required for the microscopic reversibility of evolution. Recently, an energy footprint has been theoretically proven in the atomic electron-photon interaction, as well as the well known spectroscopic phase shift effect and the results on the irreversibility of the electromagnetic interaction with atoms and molecules, experimentally obtained by R. O. Doyle in 1968. Here, we want to show that such a quantum footprint is nothing more than the generation of time .
{"title":"Time: a footprint of irreversibility","authors":"U. Lucia, Giulia Grisolia","doi":"10.1478/AAPP.971SC1","DOIUrl":"https://doi.org/10.1478/AAPP.971SC1","url":null,"abstract":"In the environment there exists a continuous interaction between electromagnetic radiation and matter. So, atoms continuously interact with the photons of the environmental electromagnetic fields. This electromagnetic interaction is a consequence of thermal non-equilibrium. It introduces an element of randomness into atomic and molecular motion, which leads to the decrease of the path probability required for the microscopic reversibility of evolution. Recently, an energy footprint has been theoretically proven in the atomic electron-photon interaction, as well as the well known spectroscopic phase shift effect and the results on the irreversibility of the electromagnetic interaction with atoms and molecules, experimentally obtained by R. O. Doyle in 1968. Here, we want to show that such a quantum footprint is nothing more than the generation of time .","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45808728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Let K be a field, E the exterior algebra of a n --dimensional K -vector space V . We study projective and injective resolutions over E . More precisely, given a category M of finitely generated Z-graded left and right E -modules, we give upper bounds for the graded Betti numbers and the graded Bass numbers of classes of modules in M .
{"title":"Minimal resolutions of graded modules over an exterior algebra","authors":"Luca Amata, M. Crupi","doi":"10.1478/AAPP.971A5","DOIUrl":"https://doi.org/10.1478/AAPP.971A5","url":null,"abstract":"Let K be a field, E the exterior algebra of a n --dimensional K -vector space V . We study projective and injective resolutions over E . More precisely, given a category M of finitely generated Z-graded left and right E -modules, we give upper bounds for the graded Betti numbers and the graded Bass numbers of classes of modules in M .","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45802669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The constitutive properties of fiber suspensions are investigated with the methods of thermodynamics. Fiber orientation, orientation change velocity and gradient of orientation are considered as relevant variables for the constitutive functions, and the Second Law of Thermodynamics in the form of the dissipation inequality is exploited by a method introduced by I-S. Liu [Arch. Rat. Mech. Analysis 46 , 131 (1972)]. The restrictions on the constitutive functions show, that the fiber suspension is a micropolar continuum with non-vanishing couple stresses. In addition it is shown that the classical relation of entropy flux being heat flux over temperature holds only in the special case that the free energy density does not depend on the orientation change velocity, otherwise there exists an extra entropy flux.
{"title":"Thermodynamic restrictions on constitutive functions for fiber suspensions","authors":"C. Papenfuss","doi":"10.1478/AAPP.971A4","DOIUrl":"https://doi.org/10.1478/AAPP.971A4","url":null,"abstract":"The constitutive properties of fiber suspensions are investigated with the methods of thermodynamics. Fiber orientation, orientation change velocity and gradient of orientation are considered as relevant variables for the constitutive functions, and the Second Law of Thermodynamics in the form of the dissipation inequality is exploited by a method introduced by I-S. Liu [Arch. Rat. Mech. Analysis 46 , 131 (1972)]. The restrictions on the constitutive functions show, that the fiber suspension is a micropolar continuum with non-vanishing couple stresses. In addition it is shown that the classical relation of entropy flux being heat flux over temperature holds only in the special case that the free energy density does not depend on the orientation change velocity, otherwise there exists an extra entropy flux.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47774442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Polimeno, R. Saija, C. Boschi, O. Maragò, M. Iatì
Optical tweezers are a crucial tool for the manipulation and characterisation, without mechanical contact, of micro- and nanoparticles, ranging from biological components, such as biomolecules, viruses, bacteria, and cells, to nanotubes, nanowires, layered materials, plasmonic nanoparticles, and their composites. Despite the many interdisciplinary applications, only recently it has been possible to develop an accurate theoretical modelling for the mesoscale size range. This goes beyond the strong approximations typically used for the calculation of optical forces on particles much smaller (dipole approximation) or much larger (ray optics) than the wavelength of the trapping light. Among the different methods used to calculate optical forces on model particles, the ones based on the transition matrix (T-matrix) are currently among the most accurate and efficient, particularly when applied to non-spherical particles, both isolated and interacting, or in composite structures. Here, we first give an overview of the theoretical background on optical forces, optomechanics, and T-matrix methods. Then, we focus on calculations of optical trapping on model polystyrene nanowires with the aim to investigate their scaling with nanowire length at the mesoscale. We compare the force constant dependence with approximations at small or large length with respect to the trapping wavelength and with calculations on spheres, pointing out the role of shape.
{"title":"Optical forces in the T-matrix formalism","authors":"P. Polimeno, R. Saija, C. Boschi, O. Maragò, M. Iatì","doi":"10.1478/AAPP.971A2","DOIUrl":"https://doi.org/10.1478/AAPP.971A2","url":null,"abstract":"Optical tweezers are a crucial tool for the manipulation and characterisation, without mechanical contact, of micro- and nanoparticles, ranging from biological components, such as biomolecules, viruses, bacteria, and cells, to nanotubes, nanowires, layered materials, plasmonic nanoparticles, and their composites. Despite the many interdisciplinary applications, only recently it has been possible to develop an accurate theoretical modelling for the mesoscale size range. This goes beyond the strong approximations typically used for the calculation of optical forces on particles much smaller (dipole approximation) or much larger (ray optics) than the wavelength of the trapping light. Among the different methods used to calculate optical forces on model particles, the ones based on the transition matrix (T-matrix) are currently among the most accurate and efficient, particularly when applied to non-spherical particles, both isolated and interacting, or in composite structures. Here, we first give an overview of the theoretical background on optical forces, optomechanics, and T-matrix methods. Then, we focus on calculations of optical trapping on model polystyrene nanowires with the aim to investigate their scaling with nanowire length at the mesoscale. We compare the force constant dependence with approximations at small or large length with respect to the trapping wavelength and with calculations on spheres, pointing out the role of shape.","PeriodicalId":43431,"journal":{"name":"Atti Accademia Peloritana dei Pericolanti-Classe di Scienze Fisiche Matematiche e Naturali","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2019-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41668904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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