Particle Transport in Quasistatic Stokes Flow

1999 ◽  
Author(s):  
Russell Keanini
Keyword(s):  
Traveling Waves ◽  
Stokes Flow ◽  
Particle Transport ◽  
Small Amplitude ◽  
Large Scale ◽  
Second Order ◽  
Particle Agglomeration ◽  
Long Time ◽  
Short Time ◽  
Streaming Flow

Abstract Particle transport associated with quasistatic second-order streaming flow in wavy-walled channels is theoretically investigated. Small amplitude tangential oscillations of both walls drive steady second-order streaming, while superposed, large-amplitude oscillations of one wall produce the time-dependent, quasisteady flows of interest. Short-time transport is characterized by collective particle motion in the direction of large-scale boundary displacement and by filamentary motion in the opposite direction, both consistent with transport in traveling waves [E. Moses and V. Steinburg, Phys. Rev. Lett. 60, 2030 (1988)]. Long time or asymptotic transport is characterized by particle agglomeration toward, or repulsion from, moving elliptic points. Under certain conditions, collective, periodic motion on the periphery of central cells also occurs. These characteristics correspond respectively to attraction or repulsion to or from period-1 elliptic points and attraction toward limit cycles on the Poincare map.

Structure and particle transport in second-order Stokes flow

2000 ◽  
Vol 61 (6) ◽  
pp. 6606-6620 ◽  
Author(s):  
Russell G. Keanini
Keyword(s):  
Stokes Flow ◽  
Particle Transport ◽  
Second Order

Statistical mechanism of passenger mobility behaviors for different transportations

2020 ◽  
Vol 31 (06) ◽  
pp. 2050082
Author(s):  
Shaoyong Han ◽  
Qiang Guo ◽  
Kai Yu ◽  
Rende Li ◽  
Bing He ◽  
...  
Keyword(s):  
Large Scale ◽  
Human Mobility ◽  
Probability Model ◽  
Travel Agency ◽  
Time Interval ◽  
Different Types ◽  
Long Time ◽  
Statistical Mechanism ◽  
Short Time ◽  
Interval Distribution

Passengers’ boarding time interval is of great significance for analysis of collective mobility behaviors. In this paper, we empirically investigate the boarding time interval of mobility behaviors based on three large-scale reservation records of passengers traveling by three different types of transportation from a travel agency platform, namely airplane, intercity bus and car rental. The statistical results show that similar properties exist in the passengers’ mobility behaviors, for example, there are similar burstiness [Formula: see text] and memory [Formula: see text] for different time interval distribution, which indicates that the passengers’ mobility behaviors are periodical. Furthermore, we present a probability model to regenerate the empirical results by assuming that the passengers’ next boarding time interval will generate between a short time of 1–7 days with probability [Formula: see text] and a random long time with probability [Formula: see text]. The simulation results show that the presented model can reproduce the burstiness and memory effect of the boarding time interval when [Formula: see text] for three empirical datasets, which suggests the periodical behaviors with the probability [Formula: see text]. This work helps in deeply understanding the regularity of human mobility behaviors.

scholarly journals RELATIVISTIC VISCOELASTIC FLUID MECHANICS

2013 ◽  
Vol 21 ◽  
pp. 189-190
Author(s):  
MASAFUMI FUKUMA ◽  
YUHO SAKATANI
Keyword(s):  
Fluid Mechanics ◽  
Viscoelastic Fluid ◽  
Stokes Equations ◽  
Second Order ◽  
Time Limit ◽  
Navier Stokes ◽  
Viscoelastic System ◽  
Navier Stokes Equations ◽  
Long Time ◽  
Short Time

We explain the relativistic theory of viscoelasticity which we have recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. This theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We then present conformal higher-order viscoelastic fluid mechanics with strain allowed to take arbitrarily large values. We particularly show that a conformal second-order fluid with all possible parameters in the constitutive equations can be obtained without breaking the hypothesis of local thermodynamic equilibrium, if the conformal fluid is defined as the long time limit of a conformal second-order viscoelastic system.

A spherical squirming swimmer in unsteady Stokes flow

2013 ◽  
Vol 723 ◽  
pp. 163-189 ◽  
Author(s):  
Kenta Ishimoto
Keyword(s):  
Stokes Flow ◽  
Small Amplitude ◽  
Wave Pattern ◽  
Swimming Velocity ◽  
Inertial Effects ◽  
Long Period ◽  
Long Time ◽  
Unsteady Stokes Flow ◽  
Micro Organisms ◽  
Time Periodic

AbstractThe motion of a spherical squirmer in unsteady Stokes flow is investigated for a deeper understanding of unsteady inertial effects on swimming micro-organisms and differences of swimming strokes between a wave pattern and a flapping motion. An asymptotic analysis with respect to the small amplitude and the small inertia is performed, and the average swimming velocity after a long period of time under an assumption of a time-periodic stroke is obtained. This analysis shows that the scallop theorem still holds in a long-time asymptotic sense for tangential deformation, but that the time variation of the shape generates a net velocity even for a reciprocal swimmer. It is also found that the inertial effects on the swimming velocity are significant for a flapping swimmer, as contrasted with little influence on that of a swimmer with a wave pattern. The inertial effect is also illustrated with a simple squirmer, so that a reciprocal motion can be almost an optimal stroke under a constraint on energy consumption.

scholarly journals Fuzzy Control for a Kite-Based Tethered Flying Robot

2015 ◽  
Vol 19 (3) ◽  
pp. 349-358 ◽  
Author(s):  
Yasutake Takahashi ◽  
◽  
Tohru Ishii ◽  
Chiaki Todoroki ◽  
Yoichiro Maeda ◽  
...  
Keyword(s):  
Large Scale ◽  
Control Unit ◽  
Flight Time ◽  
Information Gathering ◽  
Ground Control ◽  
Preparation Time ◽  
Long Time ◽  
Winding Machine ◽  
Short Time ◽  
Flying Robot

Observation providing information from above is important in in large-scale or dangerous rescue activity. This has been done from balloons or airplanes. Balloon observation requires a gas such as helium and takes a relatively long time to prepare, and while airplane observation can be prepared in a relatively short time and is highly mobile, flight time depends on the amount of fuel a plane can carry. We have proposed and developed a kite-based tethered flying robot that complements balloon and airplane observation while providing a short preparation time and long flight time [1]. The objective of our research is autonomous flight information gathering consisting of a kite, a flight unit, a tether and a ground control unit with a line-winding machine. We propose fuzzy controllers for our robot that are inspired by kite flying.

Short-Time Tests for Long-Time Endurance

1923 ◽  
Vol 128 (4) ◽  
pp. 264-264
Author(s):  
J. W. Harsch
Keyword(s):  
Long Time ◽  
Short Time

TO THE QUESTION OF RESPONSIBILITY FOR TORTURE IN THE RUSSIAN FEDERATION

2020 ◽  
Vol 10 (2) ◽  
pp. 103-106
Author(s):  
ASTEMIR ZHURTOV ◽  
Keyword(s):  
Human Rights ◽  
Russian Federation ◽  
Large Scale ◽  
Human Life ◽  
International Standards ◽  
World Community ◽  
The World ◽  
Long Time ◽  
Protection Of Human Rights ◽  
The Russian Federation

Cruel and inhumane acts that harm human life and health, as well as humiliate the dignity, are prohibited in most countries of the world, and Russia is no exception in this issue. The article presents an analysis of the institution of responsibility for torture in the Russian Federation. The author comes to the conclusion that the current criminal law of Russia superficially and fragmentally regulates liability for torture, in connection with which the author formulated the proposals to define such act as an independent crime. In the frame of modern globalization, the world community pays special attention to the protection of human rights, in connection with which large-scale international standards have been created a long time ago. The Universal Declaration of Human Rights and other international acts enshrine prohibitions of cruel and inhumane acts that harm human life and health, as well as degrade the dignity.Considering the historical experience of the past, these standards focus on the prohibition of any kind of torture, regardless of the purpose of their implementation.

Effect of Vial shaking on Loading Time of Epirubicin into Drug-Eluting Bead

2015 ◽  
Vol 5 (3) ◽  
Author(s):  
Kenji Ikeda ◽  
Yusuke Kawamura ◽  
Masahiro Kobayashi ◽  
Taito Fukushima ◽  
Yushi Sorin ◽  
...  
Keyword(s):  
Antitumor Agent ◽  
Loading Rates ◽  
Vortex Mixer ◽  
Long Time ◽  
Group A ◽  
Drug Eluting ◽  
Large Hepatocellular Carcinoma ◽  
Group B ◽  
Time Required ◽  
Short Time

Background: Although DC Bead has been useful in treatment of multiple and large hepatocellular carcinoma, loading time of doxorubicin into the DC Bead takes a long time of 30-120 minutes. Epirubicin is also used as an antitumor agent together with DC Bead, but its loading efficiency was not sufficiently elucidated. Methods: To shorten loading time of epirubicin into DC Bead (100-300µm, 300-500µm, 500-700µm), we examined the following three methods after mixing the drug: (a) let stand in room temperature, (b) agitated for 30 seconds with Vortex mixer, and (c) sonicated for 30 seconds with ultrasonic cleaner. After loading of epirubicin by each method, supernatant concentration for epirubicin was assayed at 5, 10, 30, 60, and 120 minutes. Results: Epirubicin loading rates for small bead (100-300µm) at 5 minutes were 82.9 % in group a, 93.8% in group b, and 79.9 % in group c. Similarly, medium bead (300-500µm), 40.1% in group a, 65.7% in group b and 45.5% in group c, respectively. In large-sized bead (500-700µm), loaded rates of epirubicin were 38.8% in group a, 59.0% in group b and 48.0% in group c. Agitation of mixture of epirubicin and DC Bead with Vortex mixer significantly shortened the loading time, but sonication did not affect the time required. Microscopic examination did not lead to any morphological change of microspheres in all the methods. Conclusions: Short time of agitation with Vortex mixer reduced the necessary time for loading of epirubicin in every standard of DC Bead.

Robust Test Method of TSOP PEMs for Space Application

2019 ◽  
Author(s):  
Yasunobu Iwai ◽  
Koichi Shinozaki ◽  
Daiki Tanaka
Keyword(s):  
Evaluation Method ◽  
Low Cost ◽  
Reliability Evaluation ◽  
Test Method ◽  
Thermal Shock Test ◽  
Space Application ◽  
Space Applications ◽  
Limit Test ◽  
Long Time ◽  
Short Time

Abstract Compared with space parts, consumer parts are highly functional, low cost, compact and lightweight. Therefore, their increased usage in space applications is expected. Prior testing and evaluation on space applicability are necessary because consumer parts do not have quality guarantees for space application [1]. However, in the conventional reliability evaluation method, the test takes a long time, and the problem is that the robustness of the target sample can’t be evaluated in a short time. In this report, we apply to the latest TSOP PEM (Thin Small Outline Package Plastic Encapsulated Microcircuit) an evaluation method that combines preconditioning and HALT (Highly Accelerated Limit Test), which is a test method that causes failures in a short time under very severe environmental conditions. We show that this method can evaluate the robustness of TSOP PEMs including solder connections in a short time. In addition, the validity of this evaluation method for TSOP PEM is shown by comparing with the evaluation results of thermal shock test and life test, which are conventional reliability evaluation methods.

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

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