Capillary Electrophoresis and its Basic Principles in Historical Retrospect. Part 2. Electrophoresis of Ions: the Period from its Discovery in 1800 till Faraday’s Lines of Electric Force in the 1840s.

This review is the first in a series that deals exclusively with electrophoresis of ions. Since in modern terminology "electrophoresis is the movement of dispersed particles relative to a fluid under the influence of a spatially uniform electric field”, electrophoresis is not limited to colloidal particles, it includes ions as well. The history of electrophoresis of ions therefore begins in 1800 at the same time as that of electrolysis, because the two phenomena are so inextricably linked “that one cannot happen without the other” (Faraday, 1834). Between 1800 and 1805 about half a dozen different theories of electrolytic decomposition and the movement of the particles - for which we coin the term electrophoretic current - were formulated, all contributing to the discourse, but lacking consistency and none fully convincing. They are discussed nonetheless because most of them fell into oblivion, even though they are interesting for historical reasons. However, from 1805/1806 the predominant theory, formulated by Theodor von Grotthuß and independently by Humphry Davy assumed that polarized molecules of water or dissolved ions form chains between the two electrodes. Only the terminal atoms of these chains were in direct contact with the electrodes and were liberated by galvanic action, but are immediately replaced by neighboring atoms of the same type. This decomposition and recombination of the molecules driven by electric forces which follow the “action at a distance” principle like in Coulomb´s law takes place over the entire chains; they represent the electrophoretic current. However, in 1833 Michael Faraday refuted all previous theories. Two of his groundbreaking findings were of particular importance for the electrophoresis of ions: one was that electricity consists of elementary units of charge. The ions thus carry one or a multiple of these units. The other was the revolutionary theory of the electric lines of force in early 1840s, and of what was later called the electric field. With these findings Faraday fundamentally changed the previously prevailing view of the electrophoresis of ions.

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The bursting of soap-bubbles in a uniform electric field

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100009609 ◽

1925 ◽

Vol 22 (5) ◽

pp. 728-730 ◽

Cited By ~ 85

Author(s):

C. T. R. Wilson ◽

G. I. Taylor

Keyword(s):

Electric Field ◽

Water Drop ◽

The Other ◽

Uniform Electric Field ◽

Geometrical Shape ◽

Soap Bubble ◽

Charged Drop ◽

Mathematical Discussion ◽

Mathematical Expressions ◽

The Stability

The stability of a charged raindrop has been discussed mathematically by Lord Rayleigh. The case of an uncharged drop in a uniform electric field is perhaps of more meteorological importance but a mathematical discussion of the conditions for stability turns out to be very much more difficult in this case, owing to the fact that the drop ceases to be spherical before it bursts. Moreover it does not seem possible to express its geometrical shape by means of any simple mathematical expressions. On the other hand, by using a soap bubble instead of a water drop it was found possible to carry out experiments under well-defined conditions in this case, whereas experiments with Rayleigh's charged drop would be difficult.

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Particle-Particle Interactions on the Surface of a Drop Subjected to a Uniform Electric Field

Volume 10: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A, B, and C ◽

10.1115/imece2008-67796 ◽

2008 ◽

Author(s):

S. Nudurupati ◽

M. Janjua ◽

P. Singh ◽

N. Aubry

Keyword(s):

Electric Field ◽

Immiscible Liquid ◽

The Other ◽

Uniform Electric Field ◽

Particle Interactions ◽

Drop Surface ◽

Dielectrophoretic Force ◽

Dipole Interactions ◽

Electric Field Direction ◽

Local Direction

We recently proposed a technique in which an externally applied uniform electric field was used to alter the distribution of particles on the surface of a drop immersed in another immiscible liquid. Particles move along the drop surface to form a ring near the drop equator or collect at the poles depending on their dielectric constant relative to that of the two liquid involved. This motion is due to the dielectrophoretic force that acts upon particles because the electric field on the surface of the drop is non-uniform, despite the fact that the applied electric field is uniform. This technique could be useful to concentrate particles at a drop surface within well-defined regions (poles and equator), and separate two types of particles at the surface of a drop. In this paper we show that in addition to the dielectrophoretic force the particles also interact with each other via the dipole-dipole interactions to form chains or move away from each other depending the local direction of the electric field. The regions in which the local electric field is normal to the drop surface, i.e., the poles, the particles move away from each other. On the other hand, near the equator, where the local direction of electric field is tangential to the drops surface, they form chains that are aligned parallel to the electric field direction.

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Humphry Davy, nitrous oxide, the Pneumatic Institution, and the Royal Institution

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00206.2014 ◽

2014 ◽

Vol 307 (9) ◽

pp. L661-L667 ◽

Cited By ~ 6

Author(s):

John B. West

Keyword(s):

Nitrous Oxide ◽

William Wordsworth ◽

Royal Society ◽

Samuel Taylor Coleridge ◽

Royal Institution ◽

History Of ◽

Humphry Davy ◽

Respiratory Gases ◽

Joseph Black ◽

Michael Faraday

Humphry Davy (1778–1829) has an interesting place in the history of respiratory gases because the Pneumatic Institution in which he did much of his early work signaled the end of an era of discovery. The previous 40 years had seen essentially all of the important respiratory gases described, and the Institution was formed to exploit their possible value in medical treatment. Davy himself is well known for producing nitrous oxide and demonstrating that its inhalation could cause euphoria and heightened imagination. His thinking influenced the poets Samuel Taylor Coleridge and William Wordsworth, and perhaps we can claim that our discipline colored the poetry of the Romantic Movement. Davy was also the first person to measure the residual volume of the lung. The Pneumatic Institution was the brainchild of Thomas Beddoes, who had trained in Edinburgh under Joseph Black, who discovered carbon dioxide. Later Davy moved to the Royal Institution in London formed, in part, to diffuse the knowledge of scientific discoveries to the general public. Davy was a brilliant lecturer and developed an enthusiastic following. In addition he exploited the newly described electric battery to discover several new elements. He also invented the safety lamp in response to a series of devastating explosions in coal mines. Ultimately Davy became president of the Royal Society, a remarkable honor for somebody with such humble origins. Another of his important contributions was to introduce Michael Faraday (1791–1867) to science. Faraday became one of the most illustrious British scientists of all time.

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The interpretation of the results of Bucherer's experiments on e/m

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1925.0040 ◽

1925 ◽

Vol 107 (743) ◽

pp. 544-560 ◽

Cited By ~ 4

Keyword(s):

Magnetic Field ◽

Electric Field ◽

Parallel Plate ◽

High Speed ◽

Uniform Magnetic Field ◽

Mechanical Force ◽

High Potential ◽

The Other ◽

Uniform Electric Field ◽

Left Handed

Introduction .—In the ‘Physikalische Zeitschrift,’ 9 Jahrgang, No. 22 pp. 755-760, and again, in greater detail, in the 'Annalen der Physik,’ 1909 vol. 28, pp. 513-536, Prof. A. H. Bueherer gives an account of an experiment performed by him with the object of ascertaining which of the various mass formulæ attributed to the electron by theoretical physicists agrees best with experiment. The method is briefly as follows: a source of high speed electrons (a stick of radium fluoride) is fixed on the axis of a circular parallel plate con denser, one of whose plates is connected to earth, and the other to a source o: high potential so as to produce a sensibly uniform electric field in the region between. Perpendicular to the electric field is applied a uniform magnetic field whose effect is to diminish, or increase, the mechanical force on the electron according as the direction of its velocity forms a left-handed or a right-handed system with those of the two fields. Since the distance between the plates is very small compared with their radius, it follows that the velocity of projection of an electron cannot have at arbitrary value if it is to escape from the condenser. Given the direction of projection of an electron, its velocity must lie between two definite limits which depend upon the relative intensities of the two fields, and also upon the distant between the plates of the condenser.

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Removal of Particles From the Surface of a Droplet

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2008-55247 ◽

2008 ◽

Author(s):

N. Aubry ◽

P. Singh ◽

S. Nudurupati ◽

M. Janjua

Keyword(s):

Dielectric Constant ◽

Electric Field ◽

Strong Electric Field ◽

Dielectric Constants ◽

The Other ◽

Uniform Electric Field ◽

Drop Deformation ◽

Ambient Fluid ◽

Dielectrophoretic Force ◽

Different Types

We present a technique to concentrate particles on the surface of a drop, separate different types of particles, and remove them from the drop by subjecting the drop to a uniform electric field. The particles are moved under the action of the dielectrophoretic force which arises due to the non-uniformity of the electric field on the surface of the drop. Experiments show that depending on the dielectric constants of the fluids and the particles, particles aggregate either near the poles or near the equator of the drop. When particles aggregate near the poles and the dielectric constant of the drop is greater than that of the ambient fluid, the drop deformation is larger than that of a clean drop. In this case, under a sufficiently strong electric field the drop develops conical ends and particles concentrated at the poles eject out by a tip streaming mechanism, thus leaving the drop free of particles. On the other hand, when particles aggregate near the equator, it is shown that the drop can be broken into three major droplets, with the middle droplet carrying all particles and the two larger sized droplets on the sides being free of particles. The method also allows us to separate particles for which the sign of the Clausius-Mossotti factor is different, making particles of one type aggregate at the poles and of the second type aggregate at the equator. The former are removed from the drop by increasing the electric field strength, leaving only the latter inside the drop.

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Theodor W. Adorno

10.3366/edinburgh/9781474423632.003.0024 ◽

2018 ◽

Author(s):

Colby Dickinson

Keyword(s):

The Other ◽

History Of Thought ◽

History Of ◽

The One

In his somewhat controversial book Remnants of Auschwitz, Agamben makes brief reference to Theodor Adorno’s apparently contradictory remarks on perceptions of death post-Auschwitz, positions that Adorno had taken concerning Nazi genocidal actions that had seemed also to reflect something horribly errant in the history of thought itself. There was within such murderous acts, he had claimed, a particular degradation of death itself, a perpetration of our humanity bound in some way to affect our perception of reason itself. The contradictions regarding Auschwitz that Agamben senses to be latent within Adorno’s remarks involve the intuition ‘on the one hand, of having realized the unconditional triumph of death against life; on the other, of having degraded and debased death. Neither of these charges – perhaps like every charge, which is always a genuinely legal gesture – succeed in exhausting Auschwitz’s offense, in defining its case in point’ (RA 81). And this is the stance that Agamben wishes to hammer home quite emphatically vis-à-vis Adorno’s limitations, ones that, I would only add, seem to linger within Agamben’s own formulations in ways that he has still not come to reckon with entirely: ‘This oscillation’, he affirms, ‘betrays reason’s incapacity to identify the specific crime of Auschwitz with certainty’ (RA 81).

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The World after the End of the World

Oxford Literary Review ◽

10.3366/olr.2017.0225 ◽

2017 ◽

Vol 39 (2) ◽

pp. 265-276 ◽

Cited By ~ 1

Author(s):

Kas Saghafi

Keyword(s):

The Other ◽

The World ◽

History Of ◽

The Absolute ◽

End Of The World

In several late texts, Derrida meditated on Paul Celan's poem ‘Grosse, Glühende Wölbung’, in which the departure of the world is announced. Delving into the ‘origin’ and ‘history’ of the ‘conception’ of the world, this paper suggests that, for Derrida, the end of the world is determined by and from death—the death of the other. The death of the other marks, each and every time, the absolute end of the world.

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