Thermoacoustic Modeling of a Graphene-Based Actuator

2014 ◽  
Author(s):  
Jonghoon Bin ◽  
William S. Oates ◽  
Kunihiko Taira
Keyword(s):  
Three Dimensional ◽  
Three Dimensions ◽  
Model Parameters ◽  
Three Dimensional Model ◽  
Mcmc Algorithms ◽  
Flux Boundary Conditions ◽  
Model Parameter Uncertainty ◽  
The One ◽  
Different Characteristics ◽  
Surface Temperature Variation

A model for two-dimensional graphene-based thermoacoutic membranes is investigated analytically and validated numerically in this study. In one-dimension, the temperature and the pressure variables are analytically determined by decoupling the two variables in the governing equations due to the large disparity between length scales. We further extend the one-dimensional findings to three dimensions. The three-dimensional pressure fluctuation produced by the surface temperature variation is determined with the aid of the acoustic piston model. Through the one and three-dimensional model analysis, the dependence of acoustic pressure as a function of frequency is studied and the acoustic response with respect to the frequency shows different characteristics when assuming Dirichlet (temperature) or Neumann (heat flux) boundary conditions. The general thermoacoustic model is then applied to a graphene-on-paper sound device. Probabilistic Bayesian method coupled with Monte Carlo Markov Chain (MCMC) algorithms is used to optimize model parameters and to analyze model parameter uncertainty. Excellent correlations of thermoacoustic behavior is predicted by the model which provides insight into heat transport mechanisms associated with generating sound from thermally cycling graphene at high frequencies.

A Three Dimensional Model of Zebrafish Swimming

2016 ◽  
Author(s):  
Violet Mwaffo ◽  
Sachit Butail ◽  
Maurizio Porfiri
Keyword(s):  
Ethical Issues ◽  
Three Dimensional ◽  
Coupled System ◽  
Ease Of Use ◽  
Three Dimensions ◽  
Alternative Methods ◽  
Model Parameters ◽  
Three Dimensional Model ◽  
Modeling Framework ◽  
Speed Modulation

Zebrafish is becoming an important animal model in pre-clinical studies for its genetic similarity to humans and ease of use in the laboratory. In recent years, animal experimentation has faced several ethical issues, calling for alternative methods that capitalize on dynamical systems theory. Here, we propose a computational modeling framework to simulate zebrafish swimming in three dimensions (3D) in the form of a coupled system of stochastic differential equations. The model is capable of reproducing the burst-and-coast swimming style of zebrafish, speed modulation, and avoidance of tank boundaries. Model parameters are calibrated on an experimental dataset of zebrafish swimming in 3D and validated by comparing established behavioral measures obtained from both synthetic and experimental data. We show that the model is capable of accurately predicting fish locomotion in terms of the swimming speed and number of entries in different sections of the tank. The proposed model lays the foundations for in-silico experiments of zebrafish neurobehavioral research.

scholarly journals Three-dimensional model of track growth: Comparison with other models

2003 ◽  
Vol 18 (2) ◽  
pp. 24-30 ◽  
Author(s):  
Dragoslav Nikezic ◽  
Peter Yu ◽  
Dragana Kostic
Keyword(s):  
Surface Area ◽  
Growth Models ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Nuclear Track Detectors ◽  
The One ◽  
Special Case ◽  
Track Etch

Here, we present a three-dimensional model of track growth in nuclear track detectors. The equation for the track wall in three dimensions and the equation of the contour line of the track opening have been derived for all types of tracks (i. e., tracks with sharp tips and tracks with rounded tips). The expression for the surface area of the track opening has also been found. The equations become the well-known expressions for minor and major axes for the special case of constant track etch rates. Computations of track parameters based on our model have been compared with the track growth models given by Somogyi and Szalay and the one given by Fews and Henshaw. Good agreements have been found among these three independent models.

scholarly journals Rethinking student-teacher relationships in higher education: a multidimensional approach

2021 ◽  
Author(s):  
Roland Tormey
Keyword(s):  
Higher Education ◽  
Classroom Management ◽  
Student Teacher ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Theoretical Development ◽  
Multidimensional Model ◽  
Three Dimensional Model ◽  
Teacher Relationships ◽  
Student Teacher Relationships

AbstractStudent-teacher relationships play an important role in both teacher and student experiences in higher education and have been found to be linked to learning, classroom management, and to student absenteeism. Although historically conceptualised in terms of immediacy or distance and measured with reference to behaviours, the growing recognition of the role of emotions and of power—as well as the development of a range of multidimensional models of social relationships—all suggest it is time to re-evaluate how student-teacher relationships are understood. This paper develops a theoretical model of student-teacher affective relationships in higher education based on three dimensions: affection/warmth, attachment/safety, and assertion/power. The three-dimensional model was tested using the Classroom Affective Relationships Inventory (CARI) with data from 851 students. The data supported the use of this multidimensional model for student-teacher relationships with both two- and three-dimensional models of relationships being identified as appropriate. The theoretical development of a multidimensional model and the empirical development of an instrument with which to explore these dimensions has important implications for higher education teachers, administrators and researchers.

On the numerical study of thermohydrodynamics and biochemistry of inland water bodies

2021 ◽  
Author(s):  
Daria Gladskikh ◽  
Evgeny Mortikov ◽  
Victor Stepanenko
Keyword(s):  
Mixed Layer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Water Bodies ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Lake Model ◽  
Upper Mixed Layer ◽  
The One

<p>The study of thermodynamic and biochemical processes of inland water objects using one- and three-dimensional RANS numerical models was carried out both for idealized water bodies and using measurements data. The need to take into account seiche oscillations to correctly reproduce the deepening of the upper mixed layer in one-dimensional (vertical) models is demonstrated. We considered the one-dimensional LAKE model [1] and the three-dimensional model [2, 3, 4] developed at the Research Computing Center of Moscow State University on the basis of a hydrodynamic code combining DNS/LES/RANS approaches for calculating geophysical turbulent flows. The three-dimensional model was supplemented by the equations for calculating biochemical substances by analogy with the one-dimensional biochemistry equations used in the LAKE model. The effect of mixing processes on the distribution of concentration of greenhouse gases, in particular, methane and oxygen, was studied.</p><p>The work was supported by grants of the RF President’s Grant for Young Scientists (MK-1867.2020.5, MD-1850.2020.5) and by the RFBR (19-05-00249, 20-05-00776). </p><p>1. Stepanenko V., Mammarella I., Ojala A., Miettinen H., Lykosov V., Timo V. LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes // Geoscientific Model Development. 2016. V. 9(5). P. 1977–2006.<br>2. Mortikov E.V., Glazunov A.V., Lykosov V.N. Numerical study of plane Couette flow: turbulence statistics and the structure of pressure-strain correlations // Russian Journal of Numerical Analysis and Mathematical Modelling. 2019. 34(2). P. 119-132.<br>3. Mortikov, E.V. Numerical simulation of the motion of an ice keel in stratified flow // Izv. Atmos. Ocean. Phys. 2016. V. 52. P. 108-115.<br>4. Gladskikh D.S., Stepanenko V.M., Mortikov E.V. On the influence of the horizontal dimensions of inland waters on the thickness of the upper mixed layer // Water Resourses. 2021.V. 45, 9 pages. (in press) </p>

A Fast Three-Dimensional Model for Strip Rolling

2016 ◽  
Vol 716 ◽  
pp. 566-578 ◽  
Author(s):  
Christian Overhagen ◽  
Paul Josef Mauk
Keyword(s):  
Finite Element ◽  
Stress Gradient ◽  
Three Dimensional ◽  
Significant Loss ◽  
Three Dimensions ◽  
Beam Model ◽  
Stress Distributions ◽  
Three Dimensional Model ◽  
Strip Rolling ◽  
Lateral Direction

Rolling Models have come a long way from the first empirical relations about forward slip and bite conditions to their current state, which allows local quantities to be calculated in two and three dimensions. In this paper, state-of-the-art of analytical modelling of the rolling process is shown with a fully three-dimensional rolling model for hot and cold strip rolling with stress distributions in the longitudinal, vertical and lateral directions. For this purpose, von Karman’s strip approach is extended to account for the stress gradient in lateral direction, as was already shown in different papers. The stress gradient in the vertical (through-thickness) direction is introduced by a modern implementation of Orowan’s inhomogeneous deformation theory. The local stress distributions are compared to results from Finite-Element Calculations obtained with modern FEM codes. It will be shown, under which circumstances expensive FEM calculations can be replaced by simpler models like the one proposed here, which are more time and cost-effective without a significant loss in result precision. The rolling model is extended with a Finite Element Beam Model for work and backup roll deformation, as well as local work roll flattening and thermal crown for hot rolling. The Effects of those features on stress distribution and exit strip profile are shown for hot and cold rolling.

scholarly journals A Three-Dimensional Polar Ice-Sheet Model

1977 ◽  
Vol 18 (80) ◽  
pp. 373-389 ◽  
Author(s):  
D. Jenssen
Keyword(s):  
Three Dimensional ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Phase Changes ◽  
Three Dimensions ◽  
Dimensional Model ◽  
Polar Ice ◽  
Three Dimensional Model ◽  
Temperature Dependent ◽  
Mass Depletion

AbstractA three-dimensional model of the temperature and velocity distribution within any arbitrary-shaped ice mass is described. There is a mutual interaction in the model between the flow of the ice and its thermodynamics, since the flow law used in the model is temperature-dependent.Ice growth in three dimensions is governed by mass accumulation through precipitation, by mass depletion through loss of ice over the ocean, and by continuity requirements. Phase changes at the base of the ice are accounted for. The model has been applied in art exploratory manner to the Greenland ice sheet. Changes in the ice shape and temperature are presented and discussed. The basic shortcoming of the model as here presented appears primarily due to the coarse finite-difference mesh used, and to an unsophisticated approach to modelling the boundary ice.

scholarly journals Hydraulic modeling of combined sewers overflow integrating the results of the SWMM and CFX models.

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
D. Pulgarín ◽  
J. Plaza ◽  
J. Ruge ◽  
J. Rojas
Keyword(s):  
Three Dimensional ◽  
Hydraulic Modeling ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Ansys Cfx ◽  
Combined Sewer ◽  
The One ◽  
Swmm Model

This study proposes a methodology for the calibration of combined sewer overflow (CSO), incorporating the results of the three-dimensional ANSYS CFX model in the SWMM one-dimensional model. The procedure consists of constructing calibration curves in ANSYS CFX that relate the input flow to the CSO with the overflow, to then incorporate them into the SWMM model. The results obtained show that the behavior of the flow over the crest of the overflow weir varies in space and time. Therefore, the flow of entry to the CSO and the flow of excesses maintain a non-linear relationship, contrary to the results obtained in the one-dimensional model. However, the uncertainty associated with the idealization of flow methodologies in one dimension is reduced under the SWMM model with kinematic wave conditions and simulating CSO from curves obtained in ANSYS CFX. The result obtained facilitates the calibration of combined sewer networks for permanent or non-permanent flow conditions, by means of the construction of curves in a three-dimensional model, especially when the information collected in situ is limited.

Tamizdat as a Literary Practice and Political Institution

2021 ◽  
Author(s):  
Yasha Klots
Keyword(s):  
Three Dimensional ◽  
Political Institution ◽  
Literary Canon ◽  
Dimensional Model ◽  
Binary Opposition ◽  
Three Dimensional Model ◽  
Literary Practice ◽  
Soviet Culture ◽  
Russian Literary ◽  
The One

The article seeks to define tamizdat as a literary practice and political institution of the late Soviet era. Comprising manuscripts rejected, censored, or never submitted for publication at home but smuggled through various channels out of the country and printed elsewhere, with or without their authors’ knowledge or consent, tamizdat contributed to the formation of the twentieth-century Russian literary canon. Tamizdat thus mediated the relationships of authors in Russia with the Soviet literary establishment on the one hand and with the underground on the other, while the very prospect of having their works published abroad, let alone the consequences of such a transgression, affected these authors’ choices and ideological positions in regard to both fields. The article argues, along these lines, that tamizdat was as emblematic of the literary scene after Stalin as its more familiar and better researched domestic counterparts, samizdat and gosizdat, whereby the traditional notion of late Soviet culture as a binary opposition between the official and underground fields is reinvented, instead, as a transnationally dynamic three-dimensional model.

scholarly journals Re-Evaluating the Classical Falling Body Problem

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 553 ◽  
Author(s):  
Essam R. El-Zahar ◽  
Abdelhalim Ebaid ◽  
Abdulrahman F. Aljohani ◽  
José Tenreiro Machado ◽  
Dumitru Baleanu
Keyword(s):  
Differential Equations ◽  
Body Problem ◽  
Inertial Frame ◽  
Analytic Solution ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Rotating Frame ◽  
Dimensional Model ◽  
Three Dimensional Model

This paper re-analyzes the falling body problem in three dimensions, taking into account the effect of the Earth’s rotation (ER). Accordingly, the analytic solution of the three-dimensional model is obtained. Since the ER is quite slow, the three coupled differential equations of motion are usually approximated by neglecting all high order terms. Furthermore, the theoretical aspects describing the nature of the falling point in the rotating frame and the original inertial frame are proved. The theoretical and numerical results are illustrated and discussed.

On the Recovery of 3D Spatial Statistics of Particles from 1D Measurements: Implications for Airborne Instruments

2014 ◽  
Vol 31 (10) ◽  
pp. 2078-2087 ◽  
Author(s):  
Michael L. Larsen ◽  
Clarissa A. Briner ◽  
Philip Boehner
Keyword(s):  
Point Processes ◽  
Pair Correlation ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Dimensional System ◽  
Cloud Droplets ◽  
Sampling Variability ◽  
One Dimensional ◽  
Natural Sampling ◽  
The One

Abstract The spatial positions of individual aerosol particles, cloud droplets, or raindrops can be modeled as a point processes in three dimensions. Characterization of three-dimensional point processes often involves the calculation or estimation of the radial distribution function (RDF) and/or the pair-correlation function (PCF) for the system. Sampling these three-dimensional systems is often impractical, however, and, consequently, these three-dimensional systems are directly measured by probing the system along a one-dimensional transect through the volume (e.g., an aircraft-mounted cloud probe measuring a thin horizontal “skewer” through a cloud). The measured RDF and PCF of these one-dimensional transects are related to (but not, in general, equal to) the RDF/PCF of the intrinsic three-dimensional systems from which the sample was taken. Previous work examined the formal mathematical relationship between the statistics of the intrinsic three-dimensional system and the one-dimensional transect; this study extends the previous work within the context of realistic sampling variability. Natural sampling variability is found to constrain substantially the usefulness of applying previous theoretical relationships. Implications for future sampling strategies are discussed.

Sign in / Sign up

Export Citation Format

Share Document