scholarly journals Three-Dimensional Convective Planforms for Inclined Darcy-Bénard Convection

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 83
Author(s):  
D. Andrew S. Rees ◽  
Antonio Barletta
Keyword(s):  
Rayleigh Number ◽  
Parameter Space ◽  
Three Dimensional ◽  
The Other ◽  
Spanwise Direction ◽  
Onset Of Convection ◽  
Other Hand ◽  
Benard Convection ◽  
Convection Patterns ◽  
Darcy Rayleigh Number

We investigate the onset of convection in an inclined Darcy-Bénard layer. When such a layer is unbounded in the spanwise direction it is generally known that longitudinal rolls comprise the most unstable planform. On the other hand, when a layer has a sufficiently small spanwise width, then transverse rolls form the most unstable planform. However, the layer remains stable to transverse roll disturbances when the inclination is above roughly 31 degrees from the horizontal. This paper considers the transition between these two extreme cases where the spanwise width takes moderate values and where rectangular cells are considered. It is found that the most unstable planform is quite strongly sensitive to the magnitude of the spanwise width and that there are large regions of parameter space within which three-dimensional convection patterns have the smallest critical Darcy-Rayleigh number.

A Liberating Experience. On Becoming a Work of Art

2020 ◽  
Vol 7 (2) ◽  
pp. 411-430
Author(s):  
Maja Tabea Jerrentrup
Keyword(s):  
Three Dimensional ◽  
The Body ◽  
The Other ◽  
Work Of Art ◽  
Other Hand ◽  
Film Clips ◽  
Long Time ◽  
The One ◽  
Body Painting ◽  
Dimensional Surface

Abstract The art of bodypainting that is fairly unknown to a wider public turns the body into a canvas - it is a frequently used phrase in the field of bodypainting that illustrates the challenge it faces: it uses a three-dimensional surface and has to cope with its irregularities, but also with the model’s abilities and characteristics. This paper looks at individuals who are turned into art by bodypainting. Although body painting can be very challenging for them - they have to expose their bodies and to stand still for a long time while getting transformed - models report that they enjoy both the process and the result, even if they are not confident about their own bodies. Among the reasons there are physical aspects like the sensual enjoyment, but also the feeling of being part of something artistic. This is enhanced and preserved through double staging - becoming a threedimentional work of art and then being staged for photography or film clips. This process gives the model the chance to experience their own body in a detached way. On the one hand, bodypainting closely relates to the body and on the other hand, it can help to over-come the body.

Assessment of Some Integrated Cooling Mechanisms for an Active IPEM

2004 ◽  
Author(s):  
Y. Pang ◽  
E. Scott ◽  
J. D. van Wyk ◽  
Z. Liang
Keyword(s):  
Power Electronics ◽  
Thermal Management ◽  
Three Dimensional ◽  
The Other ◽  
Other Hand ◽  
3D Packaging ◽  
3D Package

With the growing demands on the performance, cost, and advances in packaging and interconnection technology, three-dimensional (3D) packaging provides higher density packaging. On the other hand, thermal management of the 3D package becomes a very important issue. This paper assesses the various possibilities of integrated thermal management for integrated power electronics modules (IPEMs).

Three-dimensional instability of axisymmetric buoyant convection in cylinders heated from below

1996 ◽  
Vol 326 ◽  
pp. 399-415 ◽  
Author(s):  
M. Wanschura ◽  
H. C. Kuhlmann ◽  
H. J. Rath
Keyword(s):  
Rayleigh Number ◽  
Linear Stability ◽  
Critical Rayleigh Number ◽  
Three Dimensional ◽  
Base Flow ◽  
Onset Of Convection ◽  
Buoyant Convection ◽  
Thermal Boundary Conditions ◽  
Aspect Ratios ◽  
Prandtl Numbers

The stability of steady axisymmetric convection in cylinders heated from below and insulated laterally is investigated numerically using a mixed finite-difference/Chebyshev collocation method to solve the base flow and the linear stability equations. Linear stability boundaries are given for radius to height ratios γ from 0.9 to 1.56 and for Prandtl numbers Pr = 0.02 and Pr = 1. Depending on γ and Pr, the azimuthal wavenumber of the critical mode may be m = 1, 2, 3, or 4. The dependence of the critical Rayleigh number on the aspect ratio and the instability mechanisms are explained by analysing the energy transfer to the critical modes for selected cases. In addition to these results the onset of buoyant convection in liquid bridges with stress-free conditions on the cylindrical surface is considered. For insulating thermal boundary conditions, the onset of convection is never axisymmetric and the critical azimuthal wavenumber increases monotonically with γ. The critical Rayleigh number is less then 1708 for most aspect ratios.

On the infinite cluster of Bernoulli bond percolation in Scherk's graph

2001 ◽  
Vol 38 (04) ◽  
pp. 828-840
Author(s):  
Dayue Chen
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Bond Percolation ◽  
Infinite Cluster ◽  
Dimensional Lattice ◽  
Supercritical Region ◽  
Other Hand

Scherk's graph is a subgraph of the three-dimensional lattice. It was shown by Markvorsen, McGuinness and Thomassen (1992) that Scherk's graph is transient. Consider the Bernoulli bond percolation in Scherk's graph. We prove that the infinite cluster is transient for p > ½ and is recurrent for p < ½. This implies the well-known result of Grimmett, Kesten and Zhang (1993) on the transience of the infinite cluster of the Bernoulli bond percolation in the three-dimensional lattice for p > ½. On the other hand, Scherk's graph exhibits a new dichotomy in the supercritical region.

Three-dimensional absolute and convective instabilities at the onset of convection in a porous medium with inclined temperature gradient and vertical throughflow

2009 ◽  
Vol 641 ◽  
pp. 475-487 ◽  
Author(s):  
LEONID BREVDO
Keyword(s):  
Porous Medium ◽  
Rayleigh Number ◽  
Temperature Gradient ◽  
Three Dimensional ◽  
Onset Of Convection ◽  
Convective Instabilities ◽  
Homogeneous Porous Medium ◽  
Vertical Throughflow ◽  
Speed Of Propagation ◽  
Inclined Temperature Gradient

By using the mathematical formalism of absolute and convective instabilities, we study in this work the nature of unstable three-dimensional localized disturbances at the onset of convection in a flow in a saturated homogeneous porous medium with inclined temperature gradient and vertical throughflow. It is shown that for marginally supercritical values of the vertical Rayleigh numberRvthe destabilization has the character of absolute instability in all the cases in which the horizontal Rayleigh numberRhis zero or the Péclet numberQvis zero. In all the cases in whichRhandQvare both different from zero, at the onset of convection the instability is convective. In the latter cases, the growing emerging disturbance has locally the structure of a non-oscillatory longitudinal roll, and its group velocity points in the direction opposite the direction of the applied horizontal temperature gradient, i.e. parallel to the axis of the roll. The speed of propagation of the unstable wavepacket increases withQvand generally increases withRh.

Development of Haptic-Enabled Virtual Reality Applications for Engineering, Medicine and Art

2015 ◽  
Author(s):  
Hugo I. Medellín-Castillo ◽  
Germánico González-Badillo ◽  
Eder Govea ◽  
Raquel Espinosa-Castañeda ◽  
Enrique Gallegos
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
Force Feedback ◽  
Research Work ◽  
Three Dimensional ◽  
Haptic Device ◽  
The Other ◽  
Virtual Objects ◽  
Other Hand ◽  
And Training

The technological growth in the last years have conducted to the development of virtual reality (VR) systems able to immerse the user into a three-dimensional (3D) virtual environment where the user can interact in real time with virtual objects. This interaction is mainly based on visualizing the virtual environment and objects. However, with the recent beginning of haptic systems, the interaction with the virtual world has been extended to also feel, touch and manipulate virtual objects. Virtual reality has been successfully used in the development of applications in different scientific areas ranging from basic sciences, social science, education and entertainment. On the other hand, the use of haptics has increased in the last decade in domains from sciences and engineering to art and entertainment. Despite many developments, there is still relatively little knowledge about the confluence of software, enabling hardware, visual and haptic representations, to enable the conditions that best provide for an immersive sensory environment to convey information about a particular subject domain. In this paper, the state of the art of the research work regarding virtual reality and haptic technologies carried out by the authors in the last years is presented. The aim is to evidence the potential use of these technologies to develop usable systems for analysis and simulation in different areas of knowledge. The development of three different systems in the areas of engineering, medicine and art is presented. In the area of engineering, a system for the planning, evaluation and training of assembly and manufacturing tasks has been developed. The system, named as HAMS (Haptic Assembly and Manufacturing System), is able to simulate assembly tasks of complex components with force feedback provided by the haptic device. On the other hand, in the area of medicine, a surgical simulator for planning and training orthognathic surgeries has been developed. The system, named as VOSS (Virtual Osteotomy Simulator System), allows the realization of virtual osteotomies with force feedback. Finally, in the area of art, an interactive cinema system for blind people has been developed. The system is able to play a 3D virtual movie for the blind user to listen to and touch by means of the haptic device. The development of these applications and the results obtained from these developments are presented and discussed in this paper.

Finite-amplitude cellular convection in a fluidsaturated porous layer

1980 ◽  
Vol 373 (1753) ◽  
pp. 199-222 ◽  
Keyword(s):  
Rayleigh Number ◽  
Temperature Gradient ◽  
Heat Transport ◽  
Critical Rayleigh Number ◽  
Three Dimensional ◽  
Finite Amplitude ◽  
Onset Of Convection ◽  
Optimum Heat ◽  
Square Cells

The local nonlinear stability of thermal convection in fluid-saturated porous media, subjected to an adverse temperature gradient, is investigated. The critical Rayleigh number at the onset of convection and the corresponding heat transfer are determined. An approximate analytical method is presented to determine the form and amplitude of convection. To facilitate the determination of the physically preferred cell pattern, a detailed study of both two- and three-dimensional motions is made and a very good agreement with available experimental data is found. The finite-amplitude effects on the horizontal wavenumber, and the effect of the Prandtl number on the motion are discussed in detail. We find that, when the Rayleigh number is just greater than the critical value, two dimensional motion is more likely than three-dimensional motion, and the heat transport is shown to have two regions for n =1. In particular, it is shown that optimum heat transport occurs for a mixed horizontal plan form formed by the linear combination of general rectangular and square cells. Since an infinite number of steady-state finite-amplitude solutions exist for Rayleigh numbers greater than the critical number A c * , a relative stability criterion is discussed th at selects the realized solution as that having the maximum mean-square temperature gradient.

scholarly journals The Third Dimention in a Landscape

Secreta Artis ◽  
2021 ◽  
pp. 74-82
Author(s):  
Daria Vladimirovna Fomicheva
Keyword(s):  
Land Surface ◽  
Dimensional Space ◽  
Three Dimensional ◽  
The Other ◽  
Landscape Painting ◽  
The Third ◽  
Soviet Art ◽  
Other Hand ◽  
Third Dimension ◽  
Three Dimensional Space

The present study examines the principles of conveying the third dimension in landscape painting. The author analyzes the recommendations provided in J. Littlejohns’ manual entitled “The Composition of a Landscape” [London, 1931]. J. Littlejohns describes four methods of showing depth in a landscape painting, each illustrated with pictorial composition schemes: 1) portrayal of long roads, which allows one to unveil the plasticity of the land surface; 2) creation of a “route” for the viewer by means of a well-thought-out arrangement of natural landforms; 3) introduction of vertically and horizontally flowing streams of water on different picture planes; 4) depiction of cloud shadows on a distinctly hilly landscape. The author of the article compares the schemes contained in the manual of J. Littlejohns with the works of G. G. Nissky, which enables readers to comprehend and reflect on the compositions of the masterpieces created by a prominent figure in Soviet art; on the other hand, Nissky’s landscape paintings open for a deeper understanding of the meaning and effectiveness of the methods proposed by J. Littlejohns. The outlined composition techniques are certainly relevant for contemporary artists (painters, graphic artists, animators, designers, etc.) as they make it possible to achieve the plastic expressiveness of a three-dimensional space in a twodimensional image.

scholarly journals Recycling Pictures as Attract Point to Youngster in Campus Program Promotion

2018 ◽  
pp. 78-85
Author(s):  
Kartika Kusuma Wardani ◽  
Hertina Susandari ◽  
Anggra Ayu Rucitra ◽  
Arya Weny Anggraita
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Educational Institutions ◽  
Visual Effect ◽  
Moving Image ◽  
Other Hand ◽  
Complex Process ◽  
Photo Documentation ◽  
Short Time

Educational institutions need promotion tools to attract their segmentation. Promotion medium is used to increase awareness so that the youngster know about information and are interested to register themselves. A medium that has ability to show campus program in short time both attract them is using video. Video is a combination of moving image, sound, visual effect and has complex process to reach best visualization. On the other hand, sometimes the institution only has collection of documentation in photography format. The problem is how to use photo documentation to become short attractive video that shows whole institution programs. Final execution to recycle collection of pictures is using parallax style. This creation of style changes the photos to be more lifelike, which move with three dimensional cinematic effect.

Valenciennes and Banqueting Hall: Theatre Research in Three and Four Dimensions

1981 ◽  
Vol 22 (2) ◽  
pp. 161-170
Author(s):  
Robert K. Sarlós
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Four Dimensions ◽  
Personal Involvement ◽  
Other Hand ◽  
Hand Performance ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
And Performance

In a recent essay I argued for broader acceptance of two methods for understanding “past styles of performance”—the building of three dimensional models and the staging of four dimensional performance reconstructions. These alternatives to the traditional narrative essay make greater use of theatrical imagination, and aim at raising new kinds of questions rather than answering the old kind. However, lack of appropriate apparatus has prevented widespread use of these forms. Since performances are by nature “short-lived phenomena” and can be recorded but fragmentarily, unique methods are required for their study. Theoretical reconstructions cannot approximate the physical and psychological ambience of a respectable performance essay. On the other hand, performance reconstructions do not allow for scholarly caveat during presentation, or for lacunae where knowledge is lacking. Therefore I see the promise of a rich harvest in two-way stimulation between theoretical and performance essays. A pair of reports, based on personal involvement in the types of projects I advocate, follows.

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