scholarly journals The distribution of electric force in the crookes dark space

1911 ◽  
Vol 84 (573) ◽  
pp. 526-535 ◽  
Keyword(s):  
Positive Charge ◽  
Electric Force ◽  
Arithmetical Progression ◽  
Negative Glow ◽  
Geometrical Progression ◽  
Dark Space ◽  
The Subject ◽  
Metallic Wires

The electric force in the Crookes dark space and the negative glow has been the subject of a considerable number of investigations. The first determination was made by Schuster, whose results indicate the presence of a positive charge of electricity, whose density decreases in geometrical progression as the distance from the cathode increases in arithmetical progression. Graham found a curious drop in potential near the cathode, but Wehnalt, repeating these experiments, was unable to find this drop of potential, and ascribes it to the fact that the exploring points were not in the direct line of the current. Skinner§ came to the conclusion that all the fall of potential occurs at the surface of the cathode. Recently, Westphal|| has made a careful series of observations with cathodes of different metals in several gases, using a single exploring point, in which he finds a definite fall of potential— e. g . about 80 volts for Al in H 2 —at the surface of the cathode, the electric force a few millimetres away appearing from his curves nearly uniform. Now all these measurements were made by introducing exploring sounds, i. e . metallic wires or points, into the discharge, the observers trusting to these taking up the potential of the gas by which they were surrounded. The danger of such assumption has been pointed out by Sir J. J. Thomson, and for measurements made inside the dark space it seems entirely unwarranted.

XIV.—The Distribution of Electric Force in High Voltage Discharges

1927 ◽  
Vol 46 ◽  
pp. 136-148 ◽  
Author(s):  
A. E. M. Geddes
Keyword(s):  
Recent Work ◽  
High Voltage ◽  
Linear Relation ◽  
Low Voltage ◽  
Comprehensive Treatment ◽  
Electric Force ◽  
Cathode Fall ◽  
Negative Glow ◽  
Discharge Tubes ◽  
Dark Space

Within comparatively recent times a large amount of work has been done on the cathode fall of potential. As a result it is now regarded by many investigators that no sudden fall of potential occurs close to the cathode, at least in the case of low voltage discharges. A comprehensive treatment of recent work on this subject is to be found in a paper by Stücklen. Further, F. W. Aston, in his investigations on the cathode fall, came to the conclusion that practically the whole fall occurred in the dark space between the cathode and the negative glow, and that if there were any force in the negative glow it was negligible compared with that in the dark space. The potentials used by Aston across his discharge tubes were comparatively small, however, never exceeding 1000 volts. With voltages of this order he showed further that the electric force in the dark space was very nearly in linear relation with the distance from the negative glow.

scholarly journals Surface Complexation Models of Pertechnetate on Biochar/Montmorillonite Composite—Batch and Dynamic Sorption Study

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3108 ◽  
Author(s):  
Martin Daňo ◽  
Eva Viglašová ◽  
Michal Galamboš ◽  
Karel Štamberg ◽  
Jan Kujan
Keyword(s):  
Positive Charge ◽  
Surface Groups ◽  
X Ray ◽  
Montmorillonite K10 ◽  
Dynamic Sorption ◽  
The Subject ◽  
Influence Of Ph ◽  
Sorption Study ◽  
Chemical Equilibrium Model ◽  
Negative Form

The study summarizes the results of monitoring the properties of two types of sorbents, BC1 (biochar sample 1) and BC2a (biochar sample 2), prepared by pyrolysis of bamboo biomass (BC1) and as its composite with montmorillonite K10 (BC2a). The main goal was to study their applicability to the Tc (VII) separation from liquid wastes, using NH4ReO4 as a carrier. The research was focused on determining the sorbents surface properties (by XRF (X-ray fluorescence) method and potentiometric titration in order to determine the properties of surface groups—Chemical Equilibrium Model (CEM) and Ion Exchange Model (IExM) models were applied here). As well as monitoring Tc (VII) (+Re(VII)) sorption, especially to determine equilibrium isotherm, the influence of pH and kinetics. The subject of research was also the dynamics of sorption, including its mathematical–physical modeling. Both sorbents have good properties against Tc (VII), however BC2a, due to the presence of montmorillonite, is more advantageous in this respect. It has a higher sorption capacity and faster kinetic investigation. An important finding is that the optimal pH is 2–3, which is related not only to the protonation of surface groups (they have a positive charge), but also to the negative form of the existence of Tc (VII) and Re (VII): TcO4− and ReO4−.

scholarly journals On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies. In a letter to Francis Baily, Esq. F. R. S. &c. By Benjamin Gompertz, Esq. F. R. S

1833 ◽  
Vol 2 ◽  
pp. 252-253 ◽  
Keyword(s):  
Causes Of Death ◽  
Value Of Life ◽  
Arithmetical Progression ◽  
Short Intervals ◽  
Law Of Nature ◽  
General Law ◽  
Geometrical Progression ◽  
History Of ◽  
The Law ◽  
Life Annuities

This paper, which professes to be a continuation of former researches on the same subject printed in the Transactions of the Royal Society, is divided into two chapters. In the first the author considers the nature of the law of those numbers in tables of mortality, which express the amount of persons living at the end of ages in regular arithmetical progression. He remarks that for short intervals the law approaches nearly to a decreasing geometrical progression, and that this must be the case whatever be the strict expression for the law of mortality, provided the intervals do not exceed certain limits. But he further remarks, that this property will be found to belong to very extensive portions of tables of mortality, and instances Deparcieux’s tables, where from the age of 25 to that of 45, the numbers living at the end of each year decrease very nearly in geometrical progression. Considering however the whole extent of such a table, it will be found that the ratio of this geometrical progression is not the same in all parts of the table. But before he enters on this consideration, the author draws some consequences from the hypothesis of a geometrical progression being the strict law of nature after a certain age. One of these is the equality of value of all life annuities commencing after that age. Another is, that the want of instances in history of persons living to very enormous ages (waving those of the patriarchs,) is no proof that such may not be the law of nature, as he shows by calculation, that out of 3,000,000 persons of 92, not more than one should on this supposition reach 192. This leads him to some general considerations on the causes of death, after which he resumes the consideration of the general law of the tables.

J. J. Thomson and the Structure of Light

1967 ◽  
Vol 3 (4) ◽  
pp. 362-387 ◽  
Author(s):  
Russell McCormmach
Keyword(s):  
Electromagnetic Field ◽  
Quantum Theory ◽  
Experimental Work ◽  
Electric Force ◽  
The Subject

SynopsisThis essay concerns an aspect of the speculative contributions of J. J. Thomson to a field of physics somewhat removed from that upon which his popular fame and scientific eminence were alike founded. He published a number of statements in the period 1903–1910 advocating a discontinuous structure of the electromagnetic field. His unorthodox conception of the field was based upon the presumed discreteness of Faraday's physical lines of electric force. While his ideas led to significant experimental work, they were not brought together in the form of a completed theory. It was at this same time that the quantum theory was independently evolving notions of a structure of the field, and Thomson's efforts at developing a theory of light were diverted into a protracted criticism of the hypothesis of quanta. In 1924–1936 he returned to the subject of the structure of light, but these latter speculations no longer had much relevance to contemporary physical thought.

Some investigations of gas discharges by means of an exploring electrode

1927 ◽  
Vol 23 (5) ◽  
pp. 531-541 ◽  
Author(s):  
K. G. Emeléus
Keyword(s):  
Glow Discharge ◽  
Electric Field ◽  
Electron Current ◽  
Negative Glow ◽  
Gas Discharges ◽  
Slow Group ◽  
Dark Space ◽  
Current Densities ◽  
Fast Group

The glow discharge between cold aluminium electrodes in air, oxygen, nitrogen and hydrogen has been analyzed by Langmuir's method, for pressures between 0·1 and 0·4 mm. Hg, current densities of from 0·02 to 0·2 mA./sq.cm., and applied potentials between 300 and 700 volts. An annular exploring electrode has been used. It has been found that whilst practically the whole fall of potential is localized across the cathode dark space at the lower pressures, a fall of as much as 40 volts can exist across the remainder of the discharge at the higher pressures. Reversal of the electric field has been found in the negative glow, and in certain cases in the Faraday dark space, when conditions are favourable for passage of an electron current by diffusion against the field. In several instances the negative glow was at a higher potential than the anode. Two groups of electrons occur in the negative glow, together with a single fast group at the anode boundary of the cathode dark space, and a single slow group in the Faraday dark space.

scholarly journals Experiments on the length of the cathode dark space with varying current densities and pressures in different gases

1907 ◽  
Vol 79 (528) ◽  
pp. 80-95 ◽  
Keyword(s):  
Measurable Quantity ◽  
Negative Glow ◽  
Plane Parallel ◽  
Irregular Form ◽  
Dark Space ◽  
Current Densities ◽  
The Right ◽  
Different Gases ◽  
Aluminium Disc ◽  
A Current

During some experiments with various types of vacuum tubes the author was led by the behaviour of one in particular to believe that conditions were possible under which the length of the cathode dark space might be an accurately measurable quantity. This tube is shown in fig. 1. The aluminium disc cathode K is movable and exactly fits the tube containing the anode A. If it is placed to the right in the bulb and a current from a coil passed, tire dark space assumes a highly indefinite and irregular form, such as is indicated. If, however, K is slid to the left, right into the tube containing A, the boundary of the negative glow becomes a very definite plane parallel to the cathode, its distance from the cathode being the same for all positions of the latter so long as it is inside the tube and the current from the coil kept constant.

scholarly journals Electrification of water by splashing and spraying

1914 ◽  
Vol 90 (621) ◽  
pp. 531-543 ◽  
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Pure Water ◽  
Distilled Water ◽  
Dilute Solutions ◽  
Precise Data ◽  
The Subject ◽  
Vertical Jet ◽  
Made In ◽  
Complete Account

The experiments of Lenard and Sir J. J. Thomson on the electrification produced by the splashing of pure water and other liquids are well known. It was found that distilled water when splashed at a metal obstacle took up a positive charge, giving a negative charge to the air. Very dilute solutions of different substances gave very remarkable results, the sign and magnitude of the charge on the liquid depending on the dissolved substance and the degree of concentration of the solution. In all cases the electrification ultimately approached zero as the strength of the solution increased, so that for solutions of quite moderate strength the effect was inappreciable. Simpson has shown that if drops of distilled water are allowed to fall into a vertical jet of air of sufficient velocity, the drops are broken up and acquire a positive charge. Investigations of the electrification produced in the air when splashing takes place have been made by Kähler, Aselmann and Simpson. Similar investigations have been made in connection with bubbling and spraying of liquids by Townsend, Sir J. J. Thomson, Kosters, Eve and M. Bloch. A complete account of the subject will be found in a memoir by J. J. Rey. The work described in this paper was undertaken with a view to obtaining some precise data from which it might be possible to establish a connection between the charge produced on the liquid and the extent to which it had been broken up.

scholarly journals ELEMENTS OF WAVE THEORY

2010 ◽  
Vol 1 (1) ◽  
pp. 2 ◽  
Author(s):  
R. L. Wiegel ◽  
J. W. Johnson
Keyword(s):  
Surface Profile ◽  
Wave Theory ◽  
Stable Form ◽  
Periodic Waves ◽  
Arithmetical Progression ◽  
Geometrical Progression ◽  
Irrotational Motion ◽  
Opposite Manner ◽  
Surface Curve ◽  
Horizontal Bottom

The first known mathematical solution for finite height, periodic waves of stable form was developed by Gerstner (1802). From equations that were developed, Gerstner (1802) arrived at the conclusion that the surface curve was trochoidal in form. Froude (1862) and Rankine (1863) developed the theory but in the opposite manner, i.e., they started with the assumption of a trochoidal form and then developed their equations from this curve. The theory was developed for waves in water of infinite depth with the orbits of the water particles being circular, decreasing in geometrical progression as the distance below the water surface increased in arithmetical progression. Recent experiments (Wiegel, 1950) have shown that the surface profile, represented by the trochoidal equations (as well as the first few terms of Stokes' theory), closely approximates the actual profiles for waves traveling over a horizontal bottom. However the theory necessitates molecular rotation of the particles, while the manner in which waves are formed by conservative forces necessitates irrotational motion.

scholarly journals I. On stratified discharges.—IV. Stratified and unstratified forms of the jar-discharge

1878 ◽  
Vol 26 (179-184) ◽  
pp. 90-93 ◽  
Keyword(s):  
Proper Motion ◽  
The Other ◽  
Regular Array ◽  
Negative Glow ◽  
Negative Part ◽  
Vacuum Tube ◽  
Face To Face ◽  
Other Hand ◽  
Dark Space ◽  
Positively Charged

It is well known that if a Leyden jar be discharged through a vacuum-tube, the discharge generally takes the form of an unbroken column of light, extending from the point of the positive terminal to the hilt of the negative, i. e. to the extreme negative end of the tube, and that it shows no trace of either negative glow or intervening dark space. On the other hand I have found, by experiments with a large Leyden battery, that if a tube have one terminal connected with the negatively charged coating of the battery and the other held beyond striking-distance from the positively charged coating, the discharge in the tube will show a separation of the positive from the negative part by a dark intervening space. Under suitable circumstances of exhaustion it will also show striae, in the same manner as when the discharge is effected directly with a Holtz machine, having the conductors either closed or open beyond striking-distance (see Roy. Soc. Proceedings, vol. xxiii. p. 460). Again, I have found, with the same battery, that if the tube be connected otherwise as before, and held at a distance less than at first, but a little greater than striking-distance, a stratified discharge much more brilliant and more like that produced by a coil will be exhibited. It should be remarked that the latter form of discharge appears to the unassisted eye, in the cases which I have examined, as an unbroken column of light, but with a negative glow and dark space. A revolving mirror, however, re­solves the column into a regular array of striae, having a rapid proper motion towards the positive terminal. The transition from the first to the second of these forms, and from the second to the jar-discharge proper when the tube was brought within striking-distance, was, if not absolutely abrupt, at all events so rapid that this form of experiment gave no prospect of following one form into the other. "With a view to examining the transition as closely as possible a Holtz machine was employed, and the jars having been taken off, a pair of mica plates partially covered with tinfoil was used in their stead. By sliding one plate over the other, so that more or less of the covered parts were brought face to face, a jar was formed the size of which could be varied at pleasure. An air-spark of adjustable length was also introduced into the circuit between the machine and the tube.

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