Numerical simulations on the self-motion of droplets in hydrophobic microchannels driven by wettability gradient surfaces

Author(s):  
Jian Qu ◽  
Xuegui Yang ◽  
Zhiyuan Wang
2002 ◽  
Vol 11 (6) ◽  
pp. 349-355
Author(s):  
Ognyan I. Kolev

Purpose: To further investigate the direction of (I) nystagmus and (II) self-motion perception induced by two stimuli: (a) caloric vestibular stimulations and (b) a sudden halt during vertical axis rotation. Subjects and methods: Twelve normal humans received caloric stimulation at 44°C, 30°C, and 20°C while in a supine position with the head inclined 30° upwards. In a second test they were rotated around the vertical axis with the head randomly placed in two positions: tilted 30° forward or tilted 60° backward, at a constant velocity of 90°/sec for 2 minutes and then suddenly stopped. After both tests they were asked to describe their sensations of self-motion. Eye movements were recorded with an infrared video-technique. Results: Caloric stimulation evoked only horizontal nystagmus in all subjects and induced a non-uniform complex perception of angular in frontal and transverse planes (the former dominated) and linear movements along the antero-posterior axis (sinking dominated) of the subject's coordinates. The self-motion was felt with the whole body or with a part of the body. Generally the perception evoked by cold (30°C) and warm (44°C) calorics was similar, although there were some differences. The stronger stimulus (20°C) evoked not only quantitative but also qualitative differences in perception. The abrupt halt of rotation induced self-motion perception and nystagmus only in the plane of rotation. The self-motion was felt with the whole body. Conclusion: There was no difference in the nystagmus evoked by caloric stimulation and a sudden halt of vertical axis rotation (in head positions to stimulate the horizontal canals); however, the two stimuli evoked different perceptions of self-motion. Calorics provoked the sensation of self-rotation in the frontal plane and linear motion, which did not correspond to the direction of nystagmus, as well as arcing and a reset phenomenon during angular and linear self-motion, caloric-induced self-motion can be felt predominantly or only with a part of the body, depending on the self-motion intensity. The findings indicate that, unlike the self-motion induced by sudden halt of vertical axis rotation, several mechanisms take part in generating caloric-induced self-motion.


2019 ◽  
Vol 23 (6) ◽  
pp. 1169-1190
Author(s):  
Hemeng Zhang ◽  
Kyuro Sasaki ◽  
Xiaoming Zhang ◽  
Yuichi Sugai ◽  
Yongjun Wang

Author(s):  
Simone Gori ◽  
Enrico Giora ◽  
D. Alan Stubbs

This chapter discusses the Breathing Light Illusion. The Breathing Light Illusion is a size and brightness illusion elicited by the self-motion of the observer. The stimulus consists of a circular white spot that is presented on a black background, characterized by blurred boundaries. The blurred spot, which in static view seems to glow and exhibits a self-luminance appearance, is perceived as wider, brighter, and more diffuse when it is approached but smaller, darker, and sharper when one recedes from it. A possible explanation of the phenomenon is related to the superimposition of the afterimage on the physical stimulus during dynamical viewing.


1998 ◽  
Vol 184 ◽  
pp. 485-486
Author(s):  
H. Fukuda ◽  
A. Habe ◽  
K. Wada

Nuclear activities in galaxies, such as nuclear starbursts or AGNs, are supposed to be induced by gas fueling into nuclear regions of galaxies. Non-axisymmetric gravitational potential caused by a stellar bar is a convincing mechanism for triggering gas fueling (Phinney 1994). However, numerical simulations have shown that the bar can not force the gas to accrete toward the galactic center beyond the inner Lindblad resonance (ILR). As a mechanism to overcome the ILR barrier, the double barred structure (Friedli & Martinet 1993), or the self-gravity of gas (Wada & Habe 1992, 1995; Elmegreen 1994) are proposed.


PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e48293 ◽  
Author(s):  
Christophe Lopez ◽  
Caroline J. Falconer ◽  
Fred W. Mast

2019 ◽  
Author(s):  
Aubrieann Schettler ◽  
Ian Holstead ◽  
John Turri ◽  
Michael Barnett-Cowan

AbstractWe assessed how self-motion affects the visual representation of the self. We constructed a novel virtual reality experiment that systematically varied an avatar’s motion and also biological sex. Participants were presented with pairs of avatars that visually represented the participant (“self avatar”), or another person (“opposite avatar”). Avatar motion either corresponded with the participant’s motion, or was decoupled from the participant’s motion. The results show that participants identified with i) “self avatars” over “opposite avatars”, ii) avatars moving congruently with self-motion over incongruent motion, and importantly iii) identification with the “opposite avatar” over the “self avatar” when the opposite avatar’s motion was congruent with self-motion. Our results suggest that both self-motion and biological sex are relevant to the body schema and body image and that congruent bottom-up visual feedback of self-motion is particularly important for the sense of self and capable of overriding top-down self-identification factors such as biological sex.


2016 ◽  
Vol 7 (1) ◽  
pp. 1-30
Author(s):  
E I Ani

Kwame Nkrumah invokes the doctrine of emergentism in the hope of reconciling theism - a tenacious part of the African worldview - with materialism. However, in this article I seek to show that this reconciliation is not only ultimately unsuccessful, but is actually impossible. Towards this end, I identify weaknesses in what I call the six argumentative pillars of Nkrumah’s theory of emergentism (which he calls “philosophical materialism”), namely, his arguments regarding the origin of the cosmic material, the primary reality of matter, idealism, categorial convertibility, dialectic change, and the self-motion of matter. The article should provide not only alternative perspectives to Nkrumah’s metaphysics, but also highlight some broader metaphysical implications for both strong and weak emergentism. Key WordsPhilosophical materialism, consciencism, emergentism, cosmic material, categorial conversion, dialectical change, self motion of matter


Author(s):  
Yu-Xin Wang ◽  
Yu-Tong Li ◽  
Zheng Huang ◽  
Shuang-Xia Pian

In this paper, the configuration bifurcation characteristics at the vicinities of singular points going with different input parameters are investigated. Then, with the aid of the assembly configurations at the theoretical singular points, the reasons to cause the singularities are analyzed. We find that the dimensional-utmost singularities, line vectors correlation singularities and Jacobian matrix correlation singularities can occur individually or jointly while choosing different number of input parameters. The number and the combination form of the input parameters have great influences on the complexity of the singularities and the curvature radiuses of the configuration curves. Selecting a group of adjacent input parameters, the simple configuration bifurcation and the large singularity-free input parameters zones can be obtained. And adopting multi-input parameters, the self-motion regions and the singularity avoidance errors can be reduced. These new discoveries are valuable and of significance for the trajectory design, the singularity avoidance, and the self-motion control for the parallel manipulator, as well as the parallel tools.


2008 ◽  
Vol 38 (12) ◽  
pp. 2662-2684 ◽  
Author(s):  
Hitoshi Tamura ◽  
Takuji Waseda ◽  
Yasumasa Miyazawa ◽  
Kosei Komatsu

Abstract Numerical simulations were performed to investigate current-induced modulation of the spectral and statistical properties of ocean waves advected by idealized and realistic current fields. In particular, the role of nonlinear energy transfer among waves in wave–current interactions is examined. In this type of numerical simulation, it is critical to treat the nonlinear transfer function (Snl) properly, because a rigorous Snl algorithm incurs a huge computational cost. However, the applicability of the widely used discrete interaction approximation (DIA) method is strictly limited for complex wave fields. Therefore, the simplified RIAM (SRIAM) method is implemented in an operational third-generation wave model. The method approximates an infinite resonant quadruplet with 20 optimized resonance configurations. The performance of the model is assessed by applying it to fetch-limited wave growth and wave propagation against a shear current. Numerical simulations using the idealized current field revealed that the Snl retained spectral form by redistributing the refracted wave energy; this suggests that energy concentration due to ray focusing is dispersed via the self-stabilization effect of nonlinear transfer. A hindcast simulation using wind and current reanalysis data indicated that the difference in the average monthly wave height was substantial and that instantaneous wave–current interactions were highly sensitive to small current structures. Spectral shape was also modulated, and the spatial distributions of the directional bandwidth with or without current data were completely different. Moreover, the self-stabilization effect of the Snl was also confirmed in a realistic situation. These results indicate that a realistic representation of the current field is crucial for high-resolution wave forecasting.


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