Dust Figures Research Articles

Dust Figures as a Way for Mapping Surface Charge Distribution — A Review

Dust figures can be used to visualize surface charge distribution quickly and effectively. In this article, the development history and the measurement method of dust figure techniques are reviewed. The physical process and mechanism of charge recurrence is explained in the cases where different types of dust figures are used. Furthermore, recent research progress on dust figures is summarized and analyzed. Finally, future prospects for implementation of dust figure techniques to measure surface charge distribution are discussed.

Visualization of Residual Charges by Atmospheric-Pressure Plasma Jet Irradiation using Dust Figures

Visualization of Residual Charges by Atmospheric-Pressure Plasma Jet Irradiation using Dust Figures

Synchronized Generation of Positive Creeping Streamer Discharges in Atmosphere

This report deals with the experimental results of synchronized generation of creeping streamers. Two parallel spherical electrodes are placed on a insulator plate. A shading plate or a optical filter is located at the middle point of the electrodes. Lightning impulse voltage is applied to the electrodes. Applied voltage, current to the ground and surface dust figures on the insulator are recorded. This observation is repeated up to a hundred times and synchronization probabilities of two streamers started from several electrode are obtained. Without the shading plate or the optical filter between electrodes, two streamers are mostly synchronized. However, the shading plate is located, the probability decreases remarkably. The probability rapid increases again when the insulator is irradiated by ultraviolet light. In the case of the optical filters are used, the probabilities can be observed as a function of wavelength of discharge light. The probabilities are almost 100% with high-pass filter of 115 nm cutoff. This high probability is maintained until cutoff wavelength reaches 250 nm. After that, the probability sharply declines. The synchronization is induced by ultraviolet light from first streamers. Because the ultraviolet light irradiates the insulator and photoelectrons are generated as initial electrons, second streamers start from another electrode. Required energy for the synchronization is above 5eV that corresponding to wavelength of 250 nm. Not only UV region, but also the light of VUV region is effective for the synchronization.

ガス絶縁開閉装置の沿面針部分放電等価回路モデル

It is well known that the phase distribution of partial discharge in GIS depends on the source of discharge. However, the equivalent circuit model has not been considered sufficiently. On the other hand, the authors have proposed an extended Whitehead circuit model, and have explained the difference of the phase distribution of discharge. In this paper the case of needle on spacer is treated in a model GIS (300kV), and the difference of phase distribution is measured. Next the dust figures are obtained, and charged regions on the spacer are discussed. Finally, it is stated that the EMTP simulation by the extended Whitehead circuit model agrees with the result of experiments fairly well.

超音波による水中粒子のクラスタ形成 実験的考察

It is a well-known fact that a little fine dust in a glass tube containing a vibrating column of air disposes itself in recurring patterns. These striped dust patterns are called as “Kundt's Dust Figures” in honor of his discovery. The purpose of the present study is to apply the Kundt's method to solid-liquid mixtures for making concentrated solid clusters in a tube. Ultrasonic wave was used as a source of vibration. Two types of polystyrene particles and fine titanium oxide particles (powder) were used for the experiments.As the results of the experiments, the neutraly buoyant polystyrene particles formed regular stripes of concentrated clusters in salt water. With increasing the particle concentration, the stripes of the clusters disappeared and a massive cluster was gradually formed at the upper part of the tube. The particles slightly heavier than liquid also made a massive cluster in the middle of the tube. The fine titanium oxide particles did not show clear cluster patterns, however, after draining the mixture, the particles remaining on the inside wall of the tube indicated the formation of weak stripes.

From dust figures to the kinetic theory of gases: August kundt and the changing nature of experimental physics in the 1860s and 1870s

Summary This essay seeks to illuminate the changing nature of experimental physics in the 1860s and 1870s by analysing the creation of dust tubes and dust figures by the German experimentalist August Kundt, and by showing how Kundt and his associate Emil Warburg used the ‘Kundt tube’ to test the new kinetic theory of gases. In so doing, the essay seeks to show how Kundt came to revise the vision of experimental physics that he had learned from his teacher Heinrich Gustav Magnus, a vision in which the experimentalist's goal was to establish ‘the facts’. Kundt, by contrast, came to envision experimental physics as being in the service of theory: to confirm or disconfirm theory, or to provide theorists with new phenomena to theorize about. Kundt's vision, it is argued, is emblematic of the changing nature of experimental physics and reflective of the rise of the new subdisciplines of theoretical and experimental physics.

Density changes and dust figures produced by the propagation of impulse creepage discharge in transformer oil

Density changes and dust figures produced by the propagation of impulse creepage discharge in transformer oil

油中インパルス沿面放電の進展に伴う密度変化と粉像

油中インパルス沿面放電の進展に伴う密度変化と粉像

Analytical method for evaluating surface charge distribution on a dielectric from capacitive probe measurement-application to a cone-type spacer in +or-500 kV DC-GIS

The measurement of surface charging on a spacer in a +or-500-kV HVDC gas-insulated switchgear (GIS) is performed by a capacitive probe set inside the gas tank. The various factors that cause measurement errors are examined using a simple model. An analytical method to correct the measurement errors and transform the probe output into the charge distribution on the surface of the spacer is developed. The method is an extension of a numerical method for 3-D surface charge calculation. It is shown that the charge distributions from the probe measurement agree fairly well with dust figures. >

Fixing of Dust Figures in a Kundt's Tube

Experiments on the fraction of Kundt's figures noticed by R. B. Hastings and Yung-Yao-Shih were made and influence of several fixing agents investigated.

The Effect of the Room Shape on the Sound Field in Rooms (Studies on the Measurement of Absorption Coefficient by the Reverberation Chamber Method I)

In order to carry out accurate measurements of absorption coefficient by Sabine formula, the assumption of diffuse distribution of sound energy in the reverberation chamber must be fulfilled. Thus, this work was started from the basic researches of the sound field in the two and three dimensional model rooms. The standing wave pattern of each normal mode was investigated using the dust figures and other methods. At low frequencies, normal mode of vibration existed even when the room shape was made adequately irregular, and for each normal mode, spatial variation of sound pressure did not depend on room shape. However, as the room shape becomes irregular, the nodal lines of successive normal modes distribute at random in space. Also, in the properly irregular room, the variation of decay rate for each normal mode was much smaller than that of a rectangular room.

Spontaneous Electrification of Dust Figures in a Kundt's Tube

It is the purpose of this paper to present evidence that in a Kundt's tube under suitable conditions spontaneous electrification of dust particles takes place. Appreciable time is needed for the particles to acquire a measurable charge, the sign of which depends on the material of the tube as well as that of the dust.

Vitamin C content of laboratory animals, as shown by histochemical methods

Depositions of silver were revealed at the sites of appearance of ascorbic acid in the organs and tissues of white rats, guinea pigs and cats by the histochemical method of Giroud and Leblond. It was established that the distribution of ascorbic acid and its concentration in the organs was subjected to variations depending on introduction of different drugs. The multitude of forms of deposited ascorbic acid was demonstrated in different cells. It was found in the form of dust, granules, lumps, spheres and complicated figures. An attempt was made to find some association between these forms and various types of metabolism. It was established that the distribution of ascorbic acid and its concentration in the organs was subjected to variations depending on introduction of different drugs.

On the Mist-like Dust Figures

On the Mist-like Dust Figures

Dust figures formed by an electric spark

The dust figures produced by the sound waves generated by electric sparks passing between a pair of spark gaps in series show interference. Measurements of the patterns made when the distance between the gaps ranged from 15 cm. to 3 cm. show that the wave-length of the sound is constant. When a single spark gap was placed between walls, the sparks produced modified patterns. These are explained by the method of images. The patterns may be regarded as sound maps, and should prove useful in illustrating acoustical phenomena such as the directive properties of cones for high-frequency sound.

Dust Figures in a Kundt's Tube

An experimental investigation of Kundt's tube phenomena has been performed with the primary purpose of investigating the actual motions and appearances of the striations under different conditions. No attempt was made to formulate rigorous theories explaining the figures. Very clear photographs of the particles in a striation were made by causing the striation to move out to the end of the tube and remain stationary long enough to be photographed. Photographs were also taken through the eyepiece of a microscope. From these it was evident that the particles in a striation did not, in general, touch each other. Striations on either side of a long metal rod on the bottom of the tube usually showed different spacings and occurred in different numbers on either side. This could not be caused by overtones since it is unlikely that more overtones could exist on one side than on the other. An electrostatic charge in motion near the tube prevented the figures from forming. A stationary charge in no way prevented their formation. Figures destroyed by the motion of a charge would slowly build up again when the charge was brought to rest, even with the charge present.

On the circulations caused by the vibration of air in a tube

There seems a need for accurate measurements of the velocity of sound in gases, both at ordinary temperatures with chemically allied series of gases and vapours, and at high temperatures in connection with the quantum theory. The method which suggests itself at once is to utilise in some way the stationary vibrations of a gas enclosed in a tube. One procedure is to use dust to indicate the modes of vibration, in the familiar way first demonstrated by Kundt. Two other methods which do not require the use of dust are now being tested by the writer, and will be described in due course. The successful application of any tube method demands, however, a rather more precise knowledge than has hitherto been available of the behaviour of a real gas when set into vibration in a tube of finite cross section. The present paper deals with certain features of this behaviour which do not appear to have received attention before. These are a general circulation of the air from antinode to node along the walls, returning up the centre of the tube, and a vortex motion which takes place round any obstacle, provided that the amplitude of the vibration exceeds a certain limiting intensity. The effect of this vortex motion is that the forces between two bodies placed in the vibrating gas are fundamentally different from those worked out by Koenig on the tacit assumption of vortex-free motion. It was observation of the behaviour of dust particles that first led to the experiments that revealed the general circulation and the vortex motion round obstacles. It is simpler, however, to discuss the nature of these air movements first and to defer the discussion of their bearing upon the formation of the dust figures described by Kundt, which are of a more varied nature than is always realised, to a second paper. Another series of investigations is devoted to the explanation of the dust movements in terms of these new observations.

New Phenonema in a Sounding Dust Tube

WITH the view of making accurate measurements of the velocity of sound, and hence of the ratio of the two principal specific heats of gases, we have been studying the formation of dust figures in a sounding tube. Instead of using a stroked rod to produce the vibrations of known frequency, as Kundt did in the form of experiment known by his name, we employ a telephone diaphragm (actually a loud-speaker unit) excited by a current of approximately pure sine-wave form, which is produced by a suitable valve circuit. The frequency of the vibration is then varied until one of the resonant frequencies of the tube is reached, when the dust phenomena are produced with great distinctness and can be studied at leisure.

LXI.Studies in the formation of Kundt's tube dust figures—Parts I. and II

LXI.<i>Studies in the formation of Kundt's tube dust figures—Parts I. and II</i>

Lichtenberg figures

In 1777, one hundred and fifty-one years ago, Dr. George Christoph Lichtenberg, Professor of Physics in the University of Göttingen, observed that under certain conditions an electric discharge produced curious and strangely beautiful figures. Lichtenberg's apparatus and circuit arrangement were very simple and can readily be reproduced. Place a pane of glass on a metal plate connected through a spark-gap to the outside coating of a Leyden jar. Connect the tinfoil on the inside of the jar to a metallic electrode, touching the upper surface of the glass plate. When the Leyden jar is discharged, figures are produced on the glass surface around the point of contact of the electrode. These figures may be made visible by sifting some light powder, (such as lycopodium), over the glass surface. By using flower of sulphur and finely powdered red lead, or other colored powders, the different shapes of the negative and positive figures may be shown in an impressive manner. With the discovery of photography almost a century after Lichtenberg's day, a much more convenient method was obtained for visualizing the phenomena. In 1888, J. Brown and E. T. Trouvelet found that figures similar to those obtained by Lichtenberg could be obtained photographically by replacing the glass or rubber plate with a photographic plate; the emulsion side being placed in contact with the electrode. On developing the exposed plate, very beautiful figures were obtained. As the photographic plate makes a permanent record greatly superior to the dust figures, the latter are seldom used, and the photographic records are generally referred to as Lichtenberg figures although photographic Lichtenberg figures would be more specific. (To give a general view of the phenomena discussed, a number of typical positive and negative Lichtenberg figures for various forms of impressed electric surges or impulses were shown on the screen. The true Lichtenberg figures were differentiated from figures produced by brush discharges and glide sparks.)