scholarly journals Soot and Fullerenes Formation in the Premixed Benzene-Oxygen Mixture in Electric Field at Low Pressure

2011 ◽  
Vol 14 (1) ◽  
pp. 13
Author(s):  
Z.A. Mansurov ◽  
N.G. Prikhodko ◽  
B.T. Lesbayev ◽  
M. Auyelkhankyzy
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Negative Polarity ◽  
Oxygen Mixture ◽  
Positive Polarity ◽  
Direct Electric Current ◽  
Yield Parameters ◽  
Intensity Range ◽  
Maximum Decrease ◽  
Electrode Systems

<p>Influence of the direct electric current of different polarity on flame forms, soot yield, parameters of soot samples micro crystals (Lа, Lc and d<sub>002</sub>) and soot particles sizes in intensity range from 0.5 to 20 kV at electrode systems «needle-plane» at combustion of benzene-oxygen mixture at the ratio С/О = 1.0 with addition of 10% volume of argon at pressure 40 Torr was investigated. It was found that at positive polarity action of electric field rises to such a degree that at U ≥ 10 kV it leads to flame extinction. It is shown that maximum decrease in soot yield is observed at negative polarity. It was found that intensity range of electric field in which soot yield was 10% more soot yield without applying electric field. It was shown that parameters of soot micro crystals on average remain constant irrespective of intensity and polarity. Fullerenes С<sub>60</sub>, С<sub>70</sub> and PAH were identified in the extracts of soot samples by the method of IRspectroscopy.</p>

Study on Effect of Pulse Electric Field on Solidification Process of Fe-C-S Alloy Melt

2011 ◽  
Vol 284-286 ◽  
pp. 1137-1142
Author(s):  
Zhi You Liao ◽  
Hai Chuan Wang ◽  
Peng Hong ◽  
Xin Li ◽  
Shi Jun Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Pulse Electric Field ◽  
Boundary Segregation ◽  
Solidification Process ◽  
Negative Polarity ◽  
Solidification Microstructure ◽  
Grain Boundary Segregation ◽  
Positive Polarity ◽  
Pulse Electric ◽  
Migration Law

It can reduce the grain boundary segregation effectively, and improve the solidification microstructure, as well as cause the migration and redistribution of elements by adding the pulse electric field during the solidification process of the Fe-C-S alloy melt. Where, the element S migrates from the positive polarity to the negative polarity, while the migration law of the element C is reverse to that of the element S. The principal ingredient of the inclusion in solidification microstructure after treatment is FeS and a small amount of MnS, while FeS is distributed at the edge and in the centre area of the whole sample spherically.

scholarly journals Influence of direct electric field on PMCG-alginate-based microcapsule

2021 ◽  
Author(s):  
Peter Kasak ◽  
Jana Sasová ◽  
Ruqaia Shoheeduzzaman ◽  
Mirza T. Baig ◽  
Aldana Ali H. A. Alyafei ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Current ◽  
Calcium Ion ◽  
Cellulose Sulfate ◽  
Direct Electric Current ◽  
Electrokinetic Effect ◽  
Swelling Degree ◽  
Hydrated Ions ◽  
Electrokinetic Phenomenon ◽  
Acidic Conditions

AbstractIn this study, the influence of direct electric current on a microcapsule was investigated. The microcapsule consisted of a core from a calcium ion and sodium alginate (SA) complex and the microcapsule membrane was formed by the polyionic complexation of poly(methylene-co-guanidine) (PMCG) and cellulose sulfate (CS). Microcapsules showed swelling and decreasing mechanical properties under the applied electric current, and the microcapsule membrane showed anisotropic swelling on the electrode side. The effect is attributed to an electrokinetic phenomenon, predominant formation of hydroxyl ions, and the diffusion of hydrated ions. The swelling degree of the microcapsule and microcapsule membrane at different pH and the applied electric current under alkali and acidic conditions was investigated. The swelling degree was influenced by the dissociation of the membrane, which was observed after applying the electric field, which was caused by the electrokinetic effect and the neutralization of the polycation (under alkali conditions) or polyanionic (under acidic conditions) segment during membrane formation.

Growth of 4H-SiC in Current-Controlled Liquid Phase Epitaxy

2013 ◽  
Vol 740-742 ◽  
pp. 3-6 ◽  
Author(s):  
Takeshi Mitani ◽  
Masayuki Okamura ◽  
Tetsuo Takahashi ◽  
Naoyoshi Komatsu ◽  
Tomohisa Kato ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Temperature Gradient ◽  
Electric Current ◽  
Joule Heating ◽  
Liquid Phase Epitaxy ◽  
Negative Polarity ◽  
Growth Speed ◽  
Positive Polarity ◽  
Current Leads ◽  
Dc Current

4H-SiC crystallization from Si-C solution in electric current-controlled liquid phase epitaxy was investigated. The dependence of growth speed on a DC current shows that dissolution/growth is controlled by the electric current without altering temperature gradient in the furnace. Application of an electric current leads to reduction of growth speed with negative polarity and enhancement of growth speed with positive polarity. The variation of the growth speed with a DC current density has been explained by the combination of the effects of electromigration of C solute and Joule heating.

scholarly journals Corona at Large Coated Electrodes

2018 ◽  
Author(s):  
Mats Larsson ◽  
Olof Hjortstam ◽  
Håkan Faleke ◽  
Liliana Arevalo ◽  
Dong Wu ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Negative Polarity ◽  
Electrode Geometry ◽  
Positive Polarity ◽  
Electrical Fields ◽  
Insulating Material ◽  
Air Gaps ◽  
High Electric Fields ◽  
Coated Electrodes

<p>In geometries relevant form HVDC applications where large electrodes and large air gaps are utilized, the observed corona can be quite different from geometries studied in the literature where needles or wires are used as high voltage electrodes. Corona discharges at large electrodes often initiates when the electric field on the electrode surface appears lower than the critical electric field strength, 2.4 kV/mm. Surface contamination of the electrode has been pointed out as the reason for such discharge events. Our experimental results indicate that one possible way to prevent such corona is to coat the electrode with an insulating material, such as epoxy or oxide layers. It seems that the layer separates any corona inducing particle from the electrode, which in turn hinders the corona to form. However, as the layer breaks down and gets punctured, the corona preventing propertied disappears and corona forms easily. We conclude that as long as the layer doesn’t get punctured, coating electrodes with insulating material is preventing corona to initiate at electrical fields below the critical electric field, as given by the electrode geometry. In contrast to positive polarity, for negative polarity the epoxy coating could withstand high electric fields without breaking down.</p>

scholarly journals The Study of EHD Flow:Velocity and electrical power

2018 ◽  
Vol 156 ◽  
pp. 02016
Author(s):  
Sumariyah ◽  
Kusminarto ◽  
Arief Hermanto ◽  
Pekik Nuswantoro
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
High Voltage ◽  
Electrical Power ◽  
Negative Polarity ◽  
Ring Electrode ◽  
Positive Polarity ◽  
Concentric Ring ◽  
Single Ring ◽  
Gas Medium

Electrohydrodynamics (EHD) flow is the yield of the corona discharge. Corona discharge characterized by electrical phenomena that occur together in a gas medium under the influence of an electric field. In corona discharge, the electric field is not homogeneous due to the geometry of the electrode configuration. In this study, a pin-multi concentric ring electrode (P-MRE) and pin-single ring electrode (P-SRE) has been used as electrodes configuration. The objective of this research is to get the velocity of EHD flow and determining the electrical power of the EHD flow. EHD flow generated by a DC high voltage (up to 5 kV). The pin electrode was connected to a positive polarity and electrode ring/multi-concentric rings to negative polarity. Based on our result, we make a comparison of two types of corona configurations. The results were obtained that, EHD flow velocities with the P-MRE was greater than the P-SRE for the same distance and voltage. We found that u-P characteristics of EHD flow with the P-MRE and P-SRE follow relationship as u ∞ P1/3.

scholarly journals Generation of super-short avalanche electron beams in SF6

2014 ◽  
Vol 32 (2) ◽  
pp. 331-341 ◽  
Author(s):  
Cheng Zhang ◽  
Victor F. Tarasenko ◽  
Tao Shao ◽  
Dmitry V. Beloplotov ◽  
Mikhail I. Lomaev ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electric Field ◽  
Wave Front ◽  
Electron Beams ◽  
Negative Polarity ◽  
Ionization Wave ◽  
Curvature Radius ◽  
Positive Polarity ◽  
Inhomogeneous Electric Field ◽  
Diffuse Discharge

AbstractIn this work, the generation of a super-short avalanche electron beam (SAEB) in SF6 in an inhomogeneous electric field is studied on two generators with pulse rise times of 0.5 and 2 ns, respectively. The SAEB parameters in SF6 are compared with those obtained in other gases (air, nitrogen, argon, and krypton). It is shown that the SAEB amplitude in SF6 at pressures ranging from 0.05 to 0.2 MPa is commensurable with that in krypton and is much lower than that in air and nitrogen. It is also found that in SF6, SF6 mixture with 2.5% of nitrogen, and other gases, a diffuse discharge is ignited not only at negative polarity but also at positive polarity of the electrode with small curvature radius. Furthermore, the velocity of the ionization wave front in SF6 in an inhomogeneous electric field is studied. Experimental results show that the velocity of the ionization wave front in SF6 is lower than that in air and nitrogen as well as such velocity decreases when the pressure increases from 0.05 to 0.3 MPa in all gases.

Human Event-Related Potentials to Higher-Order Acoustic Spatial Changes

2002 ◽  
Vol 16 (2) ◽  
pp. 114-118 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Heikki Hämäläinen
Keyword(s):  
Working Memory ◽  
Mismatch Negativity ◽  
Spatial Information ◽  
Free Field ◽  
Event Related Potentials ◽  
Negative Polarity ◽  
Positive Polarity ◽  
Spatial Changes ◽  
Related Potentials ◽  
Human Event

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.

STUDYING THE PROCESS OF WATER EVAPORATION WITH OF CASTOR OIL IN ELECTRIC FIELD OF MULTI-ELECTRODE SYSTEMS

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
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...  
Keyword(s):  
Electric Field ◽  
Castor Oil ◽  
Water Evaporation ◽  
Electrode Systems

The Isotope Effect of a Direct Electric Current through Liquid and Solid Metals

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe
Keyword(s):  
Liquid Metal ◽  
Electric Current ◽  
Isotope Effect ◽  
Direct Current ◽  
Capillary Tube ◽  
Isotope Separation ◽  
Direct Electric Current ◽  
Separation Effect ◽  
A Current

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.

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