The Experts below are selected from a list of 703512 Experts worldwide ranked by ideXlab platform
L. De Cesare - One of the best experts on this subject based on the ideXlab platform.
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Two-time Green’s functions and spectral Density Method in nonextensive quantum statistical mechanics
Physical Review E, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
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Two-time Green's functions and spectral Density Method in nonextensive quantum statistical mechanics.
Physical review. E Statistical nonlinear and soft matter physics, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
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Spectral Density Method in quantum nonextensive thermostatistics and magnetic systems with long-range interactions
The European Physical Journal B, 2006Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:Motived by the necessity of explicit and reliable calculations, as a valid contribution to clarify the effectiveness and, possibly, the limits of the Tsallis thermostatistics, we formulate the Two-Time Green Functions Method in nonextensive quantum statistical mechanics within the optimal Lagrange multiplier framework, focusing on the basic ingredients of the related Spectral Density Method. Besides, to show how the SDM works we have performed, to the lowest order of approximation, explicit calculations of the low-temperature properties for a quantum $d$-dimensional spin-1/2 Heisenberg ferromagnet with long-range interactions decaying as $1/r^{p}$ ($r$ is the distance between spins in the lattice)
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two time green s functions and the spectral Density Method in nonextensive classical statistical mechanics
Physical Review Letters, 2001Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:: The two-time retarded and advanced Green's function technique is formulated in nonextensive classical statistical mechanics within the optimal Lagrange multiplier framework. The main spectral properties are presented and a spectral decomposition for the spectral Density is obtained. Finally, the nonextensive version of the spectral Density Method is given and its effectiveness is tested by exploring the equilibrium properties of a classical ferromagnetic spin chain.
Kambiz Ramya - One of the best experts on this subject based on the ideXlab platform.
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freeze thaw resistance and transport properties of high volume fly ash roller compacted concrete designed by maximum Density Method
Cement & Concrete Composites, 2013Co-Authors: Ali Mardaniaghabaglou, Ozge Andiccaki, Kambiz RamyaAbstract:Abstract The aim of this study is to evaluate the effect of high-volume fly ash on some durability characteristics of roller compacted concrete (RCC). In addition to a control mixture without fly ash, two different series of mixtures were prepared by partial replacement of either cement or aggregate with fly ash. The mixtures were designed by a maximum Density Method. A total of 28 mixtures having four different water/binder ratios (0.30, 0.35, 0.40 and 0.45 by mass) were prepared to determine the optimum water/binder ratio. Among these, seven mixtures containing the optimum water content were selected for further experimental study. It was observed that in the mixtures where cement was substituted with fly ash, increasing the fly ash content adversely affected the durability performance up to 90 days. However, fly ash substitution for a part of the aggregate improved the durability characteristics of the mixture as the amount of fly ash increased.
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mechanical properties of high volume fly ash roller compacted concrete designed by maximum Density Method
Construction and Building Materials, 2013Co-Authors: Ali Mardaniaghabaglou, Kambiz RamyaAbstract:Abstract In order to study the effect of high volume fly ash on mechanical properties of roller compacted concrete, in addition to control mixture containing no fly ash, in two different series of mixtures cement or aggregate was partially replaced with fly ash. The maximum aggregate size was 25 mm in all of the mixtures which were designed using maximum Density Method. The cement content of the control mixture was 250 kg/m 3 . In one series of the mixtures 20, 40 and 60 wt% of cement was replaced with fly ash. In another series, a part of aggregate (equal to 20, 40 and 60 wt% of cement) was replaced with fly ash. Totally 28 mixtures having four different water/binder ratios (0.30, 0.35, 0.4 and 0.45) were prepared. Among these, seven mixtures containing optimum water content were selected for further research. It was observed that in the mixtures where cement was substituted with fly ash, increasing the fly ash content caused reduction in compressive, splitting tensile and flexural strength values at all of the ages up to even 180 days. On the other hand, when aggregate was replaced with fly ash, increasing the fly ash content increased the strength values of the mixture at all ages compared to these of the control specimen.
A Cavallo - One of the best experts on this subject based on the ideXlab platform.
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Two-time Green’s functions and spectral Density Method in nonextensive quantum statistical mechanics
Physical Review E, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
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Two-time Green's functions and spectral Density Method in nonextensive quantum statistical mechanics.
Physical review. E Statistical nonlinear and soft matter physics, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
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Spectral Density Method in quantum nonextensive thermostatistics and magnetic systems with long-range interactions
The European Physical Journal B, 2006Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:Motived by the necessity of explicit and reliable calculations, as a valid contribution to clarify the effectiveness and, possibly, the limits of the Tsallis thermostatistics, we formulate the Two-Time Green Functions Method in nonextensive quantum statistical mechanics within the optimal Lagrange multiplier framework, focusing on the basic ingredients of the related Spectral Density Method. Besides, to show how the SDM works we have performed, to the lowest order of approximation, explicit calculations of the low-temperature properties for a quantum $d$-dimensional spin-1/2 Heisenberg ferromagnet with long-range interactions decaying as $1/r^{p}$ ($r$ is the distance between spins in the lattice)
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two time green s functions and the spectral Density Method in nonextensive classical statistical mechanics
Physical Review Letters, 2001Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:: The two-time retarded and advanced Green's function technique is formulated in nonextensive classical statistical mechanics within the optimal Lagrange multiplier framework. The main spectral properties are presented and a spectral decomposition for the spectral Density is obtained. Finally, the nonextensive version of the spectral Density Method is given and its effectiveness is tested by exploring the equilibrium properties of a classical ferromagnetic spin chain.
Ali Mardaniaghabaglou - One of the best experts on this subject based on the ideXlab platform.
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freeze thaw resistance and transport properties of high volume fly ash roller compacted concrete designed by maximum Density Method
Cement & Concrete Composites, 2013Co-Authors: Ali Mardaniaghabaglou, Ozge Andiccaki, Kambiz RamyaAbstract:Abstract The aim of this study is to evaluate the effect of high-volume fly ash on some durability characteristics of roller compacted concrete (RCC). In addition to a control mixture without fly ash, two different series of mixtures were prepared by partial replacement of either cement or aggregate with fly ash. The mixtures were designed by a maximum Density Method. A total of 28 mixtures having four different water/binder ratios (0.30, 0.35, 0.40 and 0.45 by mass) were prepared to determine the optimum water/binder ratio. Among these, seven mixtures containing the optimum water content were selected for further experimental study. It was observed that in the mixtures where cement was substituted with fly ash, increasing the fly ash content adversely affected the durability performance up to 90 days. However, fly ash substitution for a part of the aggregate improved the durability characteristics of the mixture as the amount of fly ash increased.
-
mechanical properties of high volume fly ash roller compacted concrete designed by maximum Density Method
Construction and Building Materials, 2013Co-Authors: Ali Mardaniaghabaglou, Kambiz RamyaAbstract:Abstract In order to study the effect of high volume fly ash on mechanical properties of roller compacted concrete, in addition to control mixture containing no fly ash, in two different series of mixtures cement or aggregate was partially replaced with fly ash. The maximum aggregate size was 25 mm in all of the mixtures which were designed using maximum Density Method. The cement content of the control mixture was 250 kg/m 3 . In one series of the mixtures 20, 40 and 60 wt% of cement was replaced with fly ash. In another series, a part of aggregate (equal to 20, 40 and 60 wt% of cement) was replaced with fly ash. Totally 28 mixtures having four different water/binder ratios (0.30, 0.35, 0.4 and 0.45) were prepared. Among these, seven mixtures containing optimum water content were selected for further research. It was observed that in the mixtures where cement was substituted with fly ash, increasing the fly ash content caused reduction in compressive, splitting tensile and flexural strength values at all of the ages up to even 180 days. On the other hand, when aggregate was replaced with fly ash, increasing the fly ash content increased the strength values of the mixture at all ages compared to these of the control specimen.
Francesca Cosenza - One of the best experts on this subject based on the ideXlab platform.
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Two-time Green’s functions and spectral Density Method in nonextensive quantum statistical mechanics
Physical Review E, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
-
Two-time Green's functions and spectral Density Method in nonextensive quantum statistical mechanics.
Physical review. E Statistical nonlinear and soft matter physics, 2008Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:We extend the formalism of the thermodynamic two-time Green's functions to nonextensive quantum statistical mechanics. Working in the optimal Lagrangian multiplier representation, the q -spectral properties and the Methods for a direct calculation of the two-time q Green's functions and the related q -spectral Density ( q measures the nonextensivity degree) for two generic operators are presented in strict analogy with the extensive (q=1) counterpart. Some emphasis is devoted to the nonextensive version of the less known spectral Density Method whose effectiveness in exploring equilibrium and transport properties of a wide variety of systems has been well established in conventional classical and quantum many-body physics. To check how both the equations of motion and the spectral Density Methods work to study the q -induced nonextensivity effects in nontrivial many-body problems, we focus on the equilibrium properties of a second-quantized model for a high-Density Bose gas with strong attraction between particles for which exact results exist in extensive conditions. Remarkably, the contributions to several thermodynamic quantities of the q -induced nonextensivity close to the extensive regime are explicitly calculated in the low-temperature regime by overcoming the calculation of the q grand-partition function.
-
Spectral Density Method in quantum nonextensive thermostatistics and magnetic systems with long-range interactions
The European Physical Journal B, 2006Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:Motived by the necessity of explicit and reliable calculations, as a valid contribution to clarify the effectiveness and, possibly, the limits of the Tsallis thermostatistics, we formulate the Two-Time Green Functions Method in nonextensive quantum statistical mechanics within the optimal Lagrange multiplier framework, focusing on the basic ingredients of the related Spectral Density Method. Besides, to show how the SDM works we have performed, to the lowest order of approximation, explicit calculations of the low-temperature properties for a quantum $d$-dimensional spin-1/2 Heisenberg ferromagnet with long-range interactions decaying as $1/r^{p}$ ($r$ is the distance between spins in the lattice)
-
two time green s functions and the spectral Density Method in nonextensive classical statistical mechanics
Physical Review Letters, 2001Co-Authors: A Cavallo, Francesca Cosenza, L. De CesareAbstract:: The two-time retarded and advanced Green's function technique is formulated in nonextensive classical statistical mechanics within the optimal Lagrange multiplier framework. The main spectral properties are presented and a spectral decomposition for the spectral Density is obtained. Finally, the nonextensive version of the spectral Density Method is given and its effectiveness is tested by exploring the equilibrium properties of a classical ferromagnetic spin chain.
