Search results for "Dynamic model"

Changing the General Factor of Personality and the c-fos Gene Expression with Methylphenidate and Self-Regulation Therapy

2012

[EN] A deepening in the biological nature of the general factor of personality (GFP) is suggested: the activation level of the stress system is here represented by the gene expression of c-fos. The results of a single case experimental design are reported. A model of four coupled differential equations that explains the human personality dynamics as a consequence of a single stimulant drug intake has been fitted to psychological and biological experimental data. The stimulant-drug conditioning and its adaptation to the considered mathematical model is also studied for both kinds of measures. The dynamics of the cfos expression presents a similar pattern to the dynamics of the psychological …

Simplified dynamic pressure method for kLa measurement in aerated bioreactors

2010

Abstract A simplified version of the dynamic pressure method for measuring mass-transfer coefficients in gas–liquid systems is proposed. With this method oxygen concentration in the liquid phase is monitored after a sudden change of total pressure is applied to the system. With respect to the original technique introduced by Linek [14] the simplified version here proposed greatly simplifies the data treatment, yet resulting in good accuracy for most practical purposes. In practice, with the help of a simple mathematical model, it is found that the dynamic oxygen concentration response, when plotted as residual driving force versus time in a semi-log diagram, should be expected to finally se…

Interface thermodynamic model for low pressure evaporation

1979

Optimal Paths on Urban Networks Using Travelling Times Prevision

2012

We deal with an algorithm that, once origin and destination are fixed, individuates the route that permits to reach the destination in the shortest time, respecting an assigned maximal travel time, and with risks measure below a given threshold. A fluid dynamic model for road networks, according to initial car densities on roads and traffic coefficients at junctions, forecasts the future traffic evolution, giving dynamical weights to a constrained 𝐾 shortest path algorithm. Simulations are performed on a case study to test the efficiency of the proposed procedure.

An approximate calculation method for parallel and diffuse solar irradiances on inclined surfaces in the presence of obstructing mountains or buildin…

1983

This paper presents an approximate theoretical method to calculate solar irradiances received by inclined surfaces in mountain valleys or city streets. Results can be used in mesoscale and urban dynamic modelling.

Exploring the applicability of dissipative fluid dynamics to small systems by comparison to the Boltzmann equation

2018

[Background] Experimental data from heavy-ion experiments at RHIC-BNL and LHC-CERN are quantitatively described using relativistic fluid dynamics. Even p+A and p+p collisions show signs of collective behavior describable in the same manner. Nevertheless, small system sizes and large gradients strain the limits of applicability of fluid-dynamical methods. [Purpose] The range of applicability of fluid dynamics for the description of the collective behavior, and in particular of the elliptic flow, of small systems needs to be explored. [Method] Results of relativistic fluid-dynamical simulations are compared with solutions of the Boltzmann equation in a longitudinally boost-invariant picture. …

Systematic studies of correlations between different order flow harmonics in Pb-Pb collisions at √sNN = 2.76 TeV

2018

The correlations between event-by-event fluctuations of anisotropic flow harmonic amplitudes have been measured in Pb-Pb collisions at √ s NN = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The results are reported in terms of multiparticle correlation observables dubbed symmetric cumulants. These observables are robust against biases originating from nonflow effects. The centrality dependence of correlations between the higher order harmonics (the quadrangular v 4 and pentagonal v 5 flow) and the lower order harmonics (the elliptic v 2 and triangular v 3 flow) is presented. The transverse momentum dependences of correlations between v 3 and v 2 and between v 4 and v 2 are …

Prevention of marine pollution from oil spill: The activities of MAPRES project

2008

Beyond the Vegard's law: solid mixing excess volume and thermodynamic potentials prediction, from end-members

2020

Abstract A method has been developed, herein presented, to model binary solid solutions' volume, enthalpy and Gibbs energy using the energy state functions, E ( V , S ) , of the end-members only. The E ( V , S ) s are expanded around an unknown mixing volume, V Mix , and the fundamental equilibrium equation − ( ∂ E / ∂ V ) S = P is used to determine V Mix . V Mix allows us to model enthalpy, straightforwardly. The same argument holds using Helmholtz energy, F ( V , T ) , in place of E ( V , S ) , and the equilibrium equation becomes − ( ∂ F / ∂ V ) T = P . One can readily determine the Gibbs free energy, too. The method presented remarkably simplifies computing of solid mixings' thermodynam…

Covariant description of kinetic freeze out through a finite space-like layer

2005

The problem of Freeze Out (FO) in relativistic heavy ion reactions is addressed. We develop and analyze an idealized one-dimensional model of FO in a finite layer, based on the covariant FO probability. The resulting post FO phase-space distributions are discussed for different FO probabilities and layer thicknesses.