Behavior of an electrorheological chain under squeeze flow

2016 ◽  
Vol 28 (4) ◽  
pp. 531-546 ◽  
Author(s):  
Michiro Akaiwa
Keyword(s):  
Electric Field ◽  
The Other ◽  
Potential Difference ◽  
Electrorheological Fluids ◽  
Compressive Deformation ◽  
Experimental Result ◽  
Squeeze Flow ◽  
Chain Formation ◽  
Constant Potential

Analysis of the load versus separation concerning electrorheological fluids between electrodes with application of a constant potential difference in squeeze mode was performed. From the result of the simulation, it was found that there are three forms as follows: an approaching state in which an upper electrode approaches its adjacent particle, compressive deformation of the particles, and buckling deformation and rupture of chain formation while the electrode approaches the outermost particle. From a comparison of the simulation result with the experimental result, the experimental result and simulation result are similar in form to each other. The array of the chain between the electrodes, just after the electric field is applied, although the load is not applied on the electrode, is composed of a group of strung-close particles and the electrodes that are out of contact with respect to the neighboring particles; after the load is applied, the spacing between the electrode and the particle becomes narrow, and the chain collapses due to buckling without each touching the other.

Studying on Auxiliary Gradient Rings for the Collecting Area of Electrospinning

2011 ◽  
Vol 201-203 ◽  
pp. 726-729 ◽  
Author(s):  
Da Li Liu ◽  
Xiao Yu Zhao ◽  
Hai Guang Zhang ◽  
Yuan Yuan Liu ◽  
Qing Xi Hu
Keyword(s):  
Electric Field ◽  
Maximum Intensity ◽  
The Other ◽  
Experimental Result ◽  
Mechanism Analysis ◽  
Bone Scaffold ◽  
Other Hand ◽  
Key Factor ◽  
Electric Filed

When electrospinning has been used as a special technology of regenerative bone scaffold, for raising the efficiency of electrospinning and decreasing collecting area, the mechanism of bending instability was analyzed and concluded that the force of electric field is a key factor. Auxiliary gradient rings have been added to electric field, which changed the environment of electric filed. Then, it was verified that additive gradient rings could reduce the collecting area. On the other hand, Maxwell was used to analyze the strength and structure of electric field. The maximum intensity of electric field existed in the position of nozzle. The farther apart from nozzle, the rapidly intensity decreased. When auxiliary gradient rings had been added, the intensity of instability stage showed increased trend. Mechanism analysis and experimental result were confirmed by the simulation effectively.

scholarly journals Effect of CO Molecule Orientation on the Reduction of Cu-Based Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 279
Author(s):  
Sergey Y. Sarvadii ◽  
Andrey K. Gatin ◽  
Vasiliy A. Kharitonov ◽  
Nadezhda V. Dokhlikova ◽  
Sergey A. Ozerin ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Adsorption Process ◽  
Co Adsorption ◽  
Reduction Rate ◽  
Sample Surface ◽  
Potential Difference ◽  
Precipitation Method ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

The adsorption of CO on the surface of Cu-based nanoparticles was studied in the presence of an external electric field by means of scanning tunneling microscopy (STM) and spectroscopy (STS). Nanoparticles were synthesized on the surface of a graphite support by the impregnation–precipitation method. The chemical composition of the surface of the nanoparticles was determined as a mixture of Cu2O, Cu4O3 and CuO oxides. CO was adsorbed from the gas phase onto the surface of the nanoparticles. During the adsorption process, the potential differences ΔV = +1 or −1 V were applied to the vacuum gap between the sample and the grounded tip. Thus, the system of the STM tip and sample surface formed an asymmetric capacitor, inside which an inhomogeneous electric field existed. The CO adsorption process is accompanied by the partial reduction of nanoparticles. Due to the orientation of the CO molecule in the electric field, the reduction was weak in the case of a positive potential difference, while in the case of a negative potential difference, the reduction rate increased significantly. The ability to control the adsorption process of CO by means of an external electric field was demonstrated. The size of the nanoparticle was shown to be the key factor affecting the adsorption process, and particularly, the strength of the local electric field close to the nanoparticle surface.

scholarly journals Electric potential differences across auroral generator interfaces

2013 ◽  
Vol 31 (2) ◽  
pp. 251-261 ◽  
Author(s):  
J. De Keyser ◽  
M. Echim
Keyword(s):  
Electric Field ◽  
High Altitude ◽  
Electric Fields ◽  
Electric Potential ◽  
Equilibrium Configuration ◽  
Potential Difference ◽  
Field Profile ◽  
Electric Potential Difference ◽  
Electric Field Profile

Abstract. Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

scholarly journals Calculating the Energy Spectrum of Complex Low-Dimensional Heterostructures in the Electric Field

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Svetlana N. Khonina ◽  
Sergey G. Volotovsky ◽  
Sergey I. Kharitonov ◽  
Nikolay L. Kazanskiy
Keyword(s):  
Steady State ◽  
Electric Field ◽  
Ground State ◽  
State Energy ◽  
Airy Functions ◽  
Piecewise Constant ◽  
Matrix Rank ◽  
The Matrix ◽  
Constant Potential ◽  
Low Dimensional

An algorithm for solving the steady-state Schrödinger equation for a complex piecewise-constant potential in the presence of theE-field is developed and implemented. The algorithm is based on the consecutive matching of solutions given by the Airy functions at the band boundaries with the matrix rank increasing by no more than two orders, which enables the characteristic solution to be obtained in the convenient form for search of the roots. The algorithm developed allows valid solutions to be obtained for the electric field magnitudes larger than the ground-state energy level, that is, when the perturbation method is not suitable.

scholarly journals Atmospheric electric field in the Atlantic marine boundary layer: first results from the SAIL project

2020 ◽  
Author(s):  
Susana Barbosa ◽  
Mauricio Camilo ◽  
Carlos Almeida ◽  
José Almeida ◽  
Guilherme Amaral ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Electric Field ◽  
Marine Boundary Layer ◽  
Weather Conditions ◽  
Cape Verde ◽  
The Other ◽  
Atmospheric Electric Field ◽  
Fair Weather ◽  
Near Surface ◽  
First Results

<p><span>The study of the electrical properties of the atmospheric marine boundary layer is important as the effect of natural radioactivity in driving near surface ionisation is significantly reduced over the ocean, and the concentration of aerosols is also typically lower than over continental areas, allowing a clearer examination of space-atmosphere interactions. Furthermore, cloud cover over the ocean is dominated by low-level clouds and most of the atmospheric charge lies near the earth surface, at low altitude cloud tops. </span></p><p><span>The relevance of electric field observations in the marine boundary layer is enhanced by the the fact that the electrical conductivity of the ocean air is clearly linked to global atmospheric pollution and aerosol content. The increase in aerosol pollution since the original observations made in the early 20th century by the survey ship Carnegie is a pressing and timely motivation for modern measurements of the atmospheric electric field in the marine boundary layer. Project SAIL (Space-Atmosphere-Ocean Interactions in the marine boundary Layer) addresses this challenge by means of an unique monitoring campaign on board the ship-rigged sailing ship NRP Sagres during its 2020 circumnavigation expedition. </span></p><p><span>The Portuguese Navy ship NRP Sagres departed from Lisbon on January 5th in a journey around the globe that will take 371 days. Two identical field mill sensors (CS110, Campbell Scientific) are installed </span><span>o</span><span>n the mizzen mast, one at a height of 22 m, and the other at a height of 5 meters. </span><span>A visibility sensor (SWS050, Biral) was also set-up on the same mast in order to have measurements of the extinction coefficient of the atmosphere and assess fair-weather conditions.</span><span> Further observations include gamma radiation measured with a NaI(Tl) scintillator from 475 keV to 3 MeV, cosmic radiation up to 17 MeV, and atmospheric ionisation from a cluster ion counter (Airel). The</span><span> 1 Hz measurements of the atmospheric electric field</span><span> and from all the other sensors</span><span> are </span><span>linked to the same rigorous temporal reference frame and precise positioning through kinematic GNSS observations. </span></p><p><span>Here the first results of the SAIL project will be presented, focusing on fair-weather electric field over the Atlantic. The observations obtained in the first three sections of the circumnavigation journey, including Lisbon (Portugal) - Tenerife (Spain), from 5 to 10 January, Tenerife - Praia (Cape Verde) from 13 to 19 January, and across the Atlantic from Cape Verde to Rio de Janeiro (Brasil), from January 22nd to February 14th, will be presented and discussed.</span></p>

PHYSICAL INTERPRETATION OF BLACK HOLE EVAPORATION AS A VACUUM INSTABILITY

1992 ◽  
Vol 01 (01) ◽  
pp. 169-191 ◽  
Author(s):  
R. PARENTANI ◽  
R. BROUT
Keyword(s):  
Black Hole ◽  
Electric Field ◽  
Physical Interpretation ◽  
Particle Production ◽  
Pair Creation ◽  
The Other ◽  
Static Electric Field ◽  
Black Hole Evaporation ◽  
Tunneling Mechanism ◽  
Vacuum Instability

Using tunneling concepts which account for particle production in the cases of an accelerated detector and a static electric Field in Minkowski space, the more elusive case of black hole evaporation is analyzed in terms of a detailed tunneling mechanism. For the case of the incipient black hole (collapsing star) Hawking’s “heuristic” picture in terms of pair creation, wherein one member crosses the horizon to fall into the singularity as the other is emitted to infinity, is established. The inception of tunneling is due to the motion of the star’s surface, but its completion concerns traversal of the horizon, thereby reconciling varying schools of thought concerning this problem.

Blood Gas Analysis

2011 ◽  
Author(s):  
Patrick Magee ◽  
Mark Tooley
Keyword(s):  
Electrical Potential ◽  
Physical Principle ◽  
Gas Analysis ◽  
The Other ◽  
Potential Difference ◽  
Ion Concentration ◽  
Blood Gas ◽  
Glass Membrane ◽  
Current Flows ◽  
Ph Electrode

A blood gas machine has electrodes to measure pH, pCO2 and pO2 and often measures Hb and some biochemistry as well [King et al. 2000]. Derived values from such a device include O2 saturation, O2 content, bicarbonate, base excess and total CO2. This is the Clarke electrode described in the previous section on gas analysers and is suitable for both respiratory and blood O2 analysis. A pH unit has been defined in Chapter 1 as. In words, this can be described as ‘the negative logarithm, to base ten, of the hydrogen ion concentration’. The physical principle on which the pH electrode is based depends on the fact that when a membrane separates two solutions of different [H+], a potential difference exists across the membrane. In a pH electrode, such a membrane is usually made of glass and the development of a potential difference between the two solutions is thought to be due to the migration of H+ into the glass matrix. If one solution consists of a standard [H+], the pH of the other solution can be estimated by measurement of the potential difference between them. The glass membrane used is selectively permeable to H+. No current flows in this device, which does not wear out, in contrast to the Clark electrode, in which current does flow and that does need periodic replacement. The pH measurement system is shown diagrammatically in Figure 17.1. It consists of two half cells. In one half it has an Ag/AgCl electrode and in the other a Hg/HgCl2 (calomel) electrode. Each electrode maintains a fixed electrical potential. The Ag/AgCl electrode is surrounded by a buffer solution of known pH, surrounded by the pH sensitive glass. Outside the glass membrane is the test solution, usually blood, whose pH is to be measured. It is the potential difference across the glass, between these two solutions, which is variable. The blood or other solution is separated from the calomel electrode by a porous plug and a potassium chloride salt bridge to minimise KCl diffusion. The potential difference across the system is about 60 mV per unit of pH change at 37◦C.

scholarly journals Luminous vapour from the mercury arc and the progressive changes in its spectrum

1925 ◽  
Vol 108 (746) ◽  
pp. 262-279 ◽  
Keyword(s):  
Glow Discharge ◽  
Electric Field ◽  
Arc Discharge ◽  
The Other ◽  
Line Spectrum ◽  
Mercury Vapour ◽  
Band Spectrum ◽  
Other Hand ◽  
Continuous Band

It was observed originally by Stark that a stream of mercury vapour allowed to distil away from the arc or glow discharge in vacuo remains luminous. It may be said to carry the luminosity away with it, and in the case of the arc discharge there is no difficulty in detecting the luminosity for 50 cm. or so from the source. Stark found that when a glow discharge was used, which developed the continuous band spectrum, this spectrum could be detected in the distilled vapour, along with the line spectrum. When the glow was passed through an electric field, the line spectrum was found to be quenched, leaving the band spectrum unaffected. The arc discharge, on the other hand, gave only the line spectrum in his experiments.

Polyzwitterionic aqueous solutions – a new class of electrorheological fluids

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
George S. Georgiev ◽  
Anna A. Tzoneva ◽  
Velin A. Spassov
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Aqueous Solutions ◽  
Structural Organization ◽  
Cluster Formation ◽  
Electrorheological Fluids ◽  
Core Shell ◽  
New Class ◽  
Polyelectrolyte Solutions ◽  
Direction Opposite

AbstractIt has been established that the electroviscosity effect of polyzwitterionic (PZI) aqueous solutions is more considerable than and acts in a direction opposite to that of aqueous polyelectrolyte solutions. Temperature and electric field strength influence the electroviscosity of PZI aqueous solutions in parallel, though the reasons for these effects are quite different. The unusual electroviscosity behaviour of PZI solutions is explained by a ‘core-shell’ model for the structural organization of PZI macromolecules, suggesting that cluster formation is due to intensive dipoledipole interactions between monomer units of the same or of different macromolecules.

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