scholarly journals Зміни електрогіпокампограми та поведінкових реакцій щурів при посиленні протягом тривалого стресу ГАМК-ергічних механізмів мозку

2012 ◽  
Vol 3 (1) ◽  
pp. 62-69
Author(s):  
O. Z. Мelnikova ◽  
V. P. Lyashenko
Keyword(s):  
Spectral Composition ◽  
Behavioral Reactions ◽  
Two Phase ◽  
Phase Dynamics ◽  
Brain Gaba ◽  
Prolonged Stress

The changes of waves’ power and spectral composition of electrohippocampogram (EHpG) were analyzed in rats which brain GABA-ergic mechanisms increased by gidazepam and pyracetam during prolonged stress comparatively to the indices of EHpG under isolated affective influence. The nature of two-phase dynamics of the changes could indicate an adaptogenic action of drugs. It’s shown that modulation of central processes during prolonged stress and amplification of brain GABA-ergic mechanisms are accompanied by the changes of the animals’ behavioral reactions. 

scholarly journals On the transition between turbulence regimes in particle-laden channel flows

2018 ◽  
Vol 845 ◽  
pp. 499-519 ◽  
Author(s):  
Jesse Capecelatro ◽  
Olivier Desjardins ◽  
Rodney O. Fox
Keyword(s):  
Reynolds Number ◽  
Fluid Phase ◽  
Stokes Number ◽  
Channel Flows ◽  
High Mass ◽  
Inertial Particles ◽  
Mass Loading ◽  
Two Phase ◽  
Phase Dynamics ◽  
Wide Range

Turbulent wall-bounded flows exhibit a wide range of regimes with significant interaction between scales. The fluid dynamics associated with single-phase channel flows is predominantly characterized by the Reynolds number. Meanwhile, vastly different behaviour exists in particle-laden channel flows, even at a fixed Reynolds number. Vertical turbulent channel flows seeded with a low concentration of inertial particles are known to exhibit segregation in the particle distribution without significant modification to the underlying turbulent kinetic energy (TKE). At moderate (but still low) concentrations, enhancement or attenuation of fluid-phase TKE results from increased dissipation and wakes past individual particles. Recent studies have shown that denser suspensions significantly alter the two-phase dynamics, where the majority of TKE is generated by interphase coupling (i.e.  drag) between the carrier gas and clusters of particles that fall near the channel wall. In the present study, a series of simulations of vertical particle-laden channel flows with increasing mass loading is conducted to analyse the transition from the dilute limit where classical mean-shear production is primarily responsible for generating fluid-phase TKE to high-mass-loading suspensions dominated by drag production. Eulerian–Lagrangian simulations are performed for a wide range of particle loadings at two values of the Stokes number, and the corresponding two-phase energy balances are reported to identify the mechanisms responsible for the observed transition.

scholarly journals Modeling and controlling the two-phase dynamics of the p53 network: a Boolean network approach

2014 ◽  
Vol 16 (12) ◽  
pp. 125010 ◽  
Author(s):  
Guo-Qiang Lin ◽  
Bin Ao ◽  
Jia-Wei Chen ◽  
Wen-Xu Wang ◽  
Zeng-Ru Di
Keyword(s):  
Boolean Network ◽  
Network Approach ◽  
Two Phase ◽  
Phase Dynamics ◽  
P53 Network

scholarly journals Complex network analysis of phase dynamics underlying oil-water two-phase flows

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhong-Ke Gao ◽  
Shan-Shan Zhang ◽  
Qing Cai ◽  
Yu-Xuan Yang ◽  
Ning-De Jin
Keyword(s):  
Network Analysis ◽  
Complex Network ◽  
Two Phase Flows ◽  
Two Phase ◽  
Phase Dynamics ◽  
Complex Network Analysis ◽  
Oil Water

scholarly journals Simulation of the absorption of gaseous SO2 by fog droplets using a refined interpolation-sectional droplet model

2020 ◽  
pp. 19-32
Author(s):  
Vladimir Viktorovich Pekunov
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Sulfur Dioxide ◽  
Road Transport ◽  
Two Phase ◽  
Phase Dynamics ◽  
Lagrangian Modeling ◽  
Gaseous Sulfur ◽  
Kinetics Of ◽  
Droplet Phase

This article examines the problem of numerical simulation of interaction between the gaseous sulfur dioxide emitted by road transport and fog in the conditions of high humidity. For this purpose, the author applies a multi-factor two-phase mathematical model, which takes into account the dynamics of turbulent main phase, dynamics and kinetics of the multi-sectional droplet phase, presence of thermal inconsistencies formed as a result of direct and diffused solar radiation in various ranges, diffusion of sulfur dioxide, and its absorption by the fog droplets. The article carries out a numerical calculation of the corresponding task within the modeling system of environmental processes AirEcology-P, which allows generating the optimal calculation code for a particular mathematical model. The proposed complex mathematical model that descries interaction between the emitted sulfur dioxide gas and the fog droplets is new; it specifies the calculation of the kinetics of droplet phase based on consideration of the additional factor of droplet fusion characteristic to fog. The submodel of the droplet phase was tested in the numerical simulation (the results were compared with the data of direct Lagrangian modeling of the composite of 1,000 droplets), indicating decent accuracy results. The article obtains the results of numerical simulation of interaction between the emitted SO2 and the droplets. The author demonstrates the self-cleaning ability of the atmosphere, the degree of which correlates with the initial concentration of the smallest droplets and the height from the surface.

scholarly journals Probabilistic Traffic Flow Breakdown in Stochastic Car-Following Models

2003 ◽  
Vol 1852 (1) ◽  
pp. 152-158 ◽  
Author(s):  
Dominic Jost ◽  
Kai Nagel
Keyword(s):  
Small Scale ◽  
Two Phase ◽  
Traffic Models ◽  
Phase Dynamics ◽  
Stochastic Version ◽  
Car Following ◽  
Car Following Model ◽  
Phase Models ◽  
Two Phases ◽  
Probabilistic Nature

Whether traffic displays multiple phases (e.g., laminar, jammed, synchronized) has been much discussed. Computational evidence is presented that a stochastic car-following model can be moved from two phases (laminar and jammed) to one phase by changing one of its parameters. Models with two phases show three states. Two of them are homogeneous and correspond to the two phases. The third state consists of a mix of the two phases (phase coexistence). Although the gas–liquid analogy to traffic models has been widely discussed, no traffic-related model ever displayed a completely understood stochastic version of that transition. A stochastic model is important to the understanding of the potentially probabilistic nature of the transition. If indeed two-phase models describe certain aspects correctly, predictions for breakdown probabilities can be made. Alternatively, if one-phase models describe these aspects better, there is no breakdown. Interestingly, such one-phase models can still allow for jam formation on a small scale, which may give the impression of two-phase dynamics.

A Simplified Gas-Liquid Flow Model for Kick Mitigation and Control During Drilling Operations

2015 ◽  
Author(s):  
Ulf Jakob F. Aarsnes ◽  
Adrian Ambrus ◽  
Ali Karimi Vajargah ◽  
Ole Morten Aamo ◽  
Eric van Oort
Keyword(s):  
Real Time ◽  
Time Estimation ◽  
Pressure Profile ◽  
Recursive Least Squares ◽  
Model Parameters ◽  
Two Phase ◽  
Hyperbolic Pde ◽  
Phase Dynamics ◽  
First Order ◽  
And Control

Real-time estimation of annular pressure profile and formation pressure is crucial for the execution and planning of a well control operation, especially when drilling formations with narrow pore and fracture pressure margins. A simple transient multi-phase simulator, capable of accurately representing gas and liquid dynamics while minimizing complexity and computational requirements, is highly desirable for real-time kick mitigation and control applications. Such a simulator is presented here in the form of a coupled ODE-PDE model composed of a first order ODE and a first order hyperbolic PDE. This model is shown to retain the dominating two-phase dynamics encountered during gas kick incidents. As a particular application, we demonstrate the use of the model in design of switched control algorithms for kick handling in a Managed Pressure Drilling setting. A Recursive Least Squares algorithm is employed for estimation of unknown model parameters.

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