scholarly journals II. On an electrodynamic balance

1881 ◽  
Vol 32 (212-215) ◽  
pp. 39-40
Keyword(s):  
Internal Friction ◽  
Copper Wire ◽  
Thin Sheet ◽  
The Other ◽  
Electric Currents ◽  
Fixed Position ◽  
Chemical Balance ◽  
Electrodynamic Balance ◽  
A Current ◽  
Satisfactory Manner

In order to avoid the disturbances produced by the variations of direction and intensity of terrestrial magnetism in measuring the intensity of galvanic currents by their electromagnetic effects, I have tried to construct an electrodynamic balance. I have suspended at the ends of the lever of a smaller chemical balance, instead of the scales, two coils of copper wire, their height being equal to the diameter of the cylinder around which the wire is coiled up. Their axis is vertical, and they are suspended in such a manner that they cannot turn around this axis. Two larger spirals of the same height, but of greater radius, are placed into a fixed position, borne by a horizontal metallic rod, the middle of which is fixed on the column bearing the balance. The connexions of the wires are arranged in such a way that one of the movable coils is attracted by the fixed coil, the other is repelled. Both the fixed coils are placed a little higher than the movable coils. The attracted coil rises, the other sinks down as soon as a current passes through the circuit. There are two difficulties to be overcome in the construction of such a balance. At first, the current must be introduced into the movable spirals without diminishing their mobility, and without introducing places of contact of too small a pressure, which would make the resistance variable. I have succeeded to do this in a very satisfactory manner by using a kind of very thin sheet-brass, used for playthings of children, called in German “Rauschgold” (tinsel), because it looks like gold, and makes a crackling noise when it is moved, btrips of this, about 30 centims. long and 6 or 7 millims. broad, are very flexible, and show no signs of internal friction, their resistance to electric currents is very moderate, and they are not easily heated even by strong currents, because they have a relatively large surface in con­tact with air. I have connected each of the movable spirals with the other wires conducting the current by two such strips hanging loosely down from four pieces of brass fixed at the upper parts of the case of the balance. I may be allowed to remark, that strips of the same kind, and of greater length, are very useful to demonstrate the action of a magnet on a movable cnrrent. If you suspend the strip so that it hangs down in a curve, it is attracted, repelled, even raised against gravity, or coiled up around the magnet with great rapidity, in a very striking way.

scholarly journals Electro-physiological researches.—Fourth memoir

1851 ◽  
Vol 5 ◽  
pp. 629-629
Keyword(s):  
Electric Current ◽  
Direct Current ◽  
The Other ◽  
Electric Currents ◽  
Physiological Action ◽  
Other Hand ◽  
A Current ◽  
Contrary Direction ◽  
Mixed Nerve

In the prosecution of his inquiries on the physiological action of electric currents, the author found it necessary to employ an apparatus, which was expressly made for him by M. Bréguet, adapted to the delicate appreciation of the intensity of the force of the mus­cular contractions excited by those currents; of which apparatus he gives a minute description, illustrated by a drawing. He was thus enabled to institute an exact comparison between the contrac­tions caused by the direct, and those by the reverse currents, both at the commencement and at the termination of their action. The following are the general conclusions he deduces from the experi­ments thus conducted. 1. The passage of the electric current through a mixed nerve pro­duces a variation in the excitability of the nerve, differing essen­tially in degree, according to the direction of the current through the nerve. This excitability is weakened and ultimately destroyed; and this takes place more or less rapidly according as the direct current , that is, a current circulating through the nerve from the centre to the periphery, is more or less intense. On the other hand, by the passage of the same current in the contrary direction, that is, from the periphery to the centre, or the inverse current , the ex­citability is preserved and increased.

Rem Study of Current Effect on the Structure of Clean Si(111) Surface

1990 ◽  
Vol 48 (1) ◽  
pp. 306-307
Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi
Keyword(s):  
The Other ◽  
Current Direction ◽  
Clean Surface ◽  
Current Effect ◽  
Atomic Steps ◽  
Step Bunching ◽  
Terrace Width ◽  
Step Down ◽  
A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

STUDI OF FRUIT LEATHER PROCESSING OF MANGGO

2013 ◽  
Vol 3 (2) ◽  
pp. 124-132
Author(s):  
Yessy Rosalina ◽  
Laili Susanti ◽  
Tatik Sulasmi
Keyword(s):  
Thin Sheet ◽  
Physical Appearance ◽  
The Other ◽  
Drying Temperature ◽  
Fruit Flesh ◽  
Leather Processing ◽  
High Yielding Varieties ◽  
Processing Techniques

Mango varieties Bengkulu is one of high yielding varieties from Bengkulu Province. The plants grow well and produce fruits almost year-around in all regions in the province of Bengkulu. Mango varieties Bengkulu have very large fruit, thick fruit flesh and slightly sour flavors. It makes Mango varieties Bengkulu is very suitable to be consumed in the form of a processed. Fruit leather is one form of processed fruit. Fruit leather is a thin sheet of fruit in dried form. The results showed that the best processing techniques of fruit leather for mango varieties Bengkulu is the process with addition of sugar by 20% and drying temperature at 60 ?C. The treatment produce fruit leather with the best physical appearance and flavor compared with the other treatments.

scholarly journals XXIII.—On the Disruptive Discharge of Electricity: An Experimental Thesis for the Degree of Doctor of Science, Department A

1878 ◽  
Vol 28 (2) ◽  
pp. 633-671 ◽  
Author(s):  
Alexander Macfarlane
Keyword(s):  
Copper Wire ◽  
Late Summer ◽  
The Other ◽  
Straight Line ◽  
Summer Session ◽  
The Difference ◽  
A Chain ◽  
The One ◽  
Metallic Parts ◽  
The University

The experiments to which I shall refer were carried out in the physical laboratory of the University during the late summer session. I was ably assisted in conducting the experiments by three students of the laboratory,—Messrs H. A. Salvesen, G. M. Connor, and D. E. Stewart. The method which was used of measuring the difference of potential required to produce a disruptive discharge of electricity under given conditions, is that described in a paper communicated to the Royal Society of Edinburgh in 1876 in the names of Mr J. A. Paton, M. A., and myself, and was suggested to me by Professor Tait as a means of attacking the experimental problems mentioned below.The above sketch which I took of the apparatus in situ may facilitate tha description of the method. The receiver of an air-pump, having a rod capable of being moved air-tight up and down through the neck, was attached to one of the conductors of a Holtz machine in such a manner that the conductor of the machine and the rod formed one conducting system. Projecting from the bottom of the receiver was a short metallic rod, forming one conductor with the metallic parts of the air-pump, and by means of a chain with the uninsulated conductor of the Holtz machine. Brass balls and discs of various sizes were made to order, capable of being screwed on to the ends of the rods. On the table, and at a distance of about six feet from the receiver, was a stand supporting two insulated brass balls, the one fixed, the other having one degree of freedom, viz., of moving in a straight line in the plane of the table. The fixed insulated ball A was made one conductor with the insulated conductor of the Holtz and the rod of the receiver, by means of a copper wire insulated with gutta percha, having one end stuck firmly into a hole in the collar of the receiver, and having the other fitted in between the glass stem and the hollow in the ball, by which it fitted on to the stem tightly. A thin wire similarly fitted in between the ball B and its insulating stem connected the ball with the insulated half ring of a divided ring reflecting electrometer.

Ground vibrations near dynamite blasts*

1939 ◽  
Vol 29 (3) ◽  
pp. 487-496
Author(s):  
L. Don Leet
Keyword(s):  
Internal Friction ◽  
Initial Energy ◽  
The Other ◽  
Ground Vibrations ◽  
Two Factors ◽  
Natural Decay

Summary In general, then, the concentrated energy at the source is actually divided among the principal wave types, which are there added together. Within very short distances, however, these wave types begin to separate because of their different velocities. There are thus two factors working to reduce the maximum shaking to which the ground is subjected. One is the natural decay of each wave with distance, as internal friction exhausts its original energy. The other, which is usually the dominating effect at short distances, is this stringing out of the wave types, each carrying its portion of the initial energy, until there is no longer any concentration where two or more types join forces to produce additive amplitudes.

Ventricular fibrillation during uniform myocardial anoxia due to asphyxia

1960 ◽  
Vol 198 (5) ◽  
pp. 955-958 ◽  
Author(s):  
Jay D. Coffman ◽  
D. E. Gregg
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Potassium Level ◽  
Serum Potassium Level ◽  
Current Theory ◽  
The Other ◽  
Right Atrial ◽  
Serum Electrolytes ◽  
Anesthetized Dogs ◽  
A Current

Thirty-three anesthetized dogs of varying weights were subjected to complete asphyxia by tracheal occlusion to produce uniform anoxia of the heart. Eleven showed electrocardiographic evidence of ventricular fibrillation while the other twenty-two demonstrated cardiac arrest. The development of ventricular fibrillation correlated with the heavier body and heart weights and with a lower average right atrial serum potassium level as compared to the dogs not fibrillating. Other serum electrolytes, pH, body temperature and sex showed no correlation with the arrhythmia. The importance of the fact that large dogs have a greater susceptibility to develop ventricular fibrillation during uniform anoxia of the heart is discussed in relation to experimental research on dogs and to a current theory of the cause of ventricular fibrillation.

Statistics on Jupiter's Current Sheet with Juno Data: Geometry, Magnetic Fields and Energetic Particles

2021 ◽  
Author(s):  
Zhi-Yang Liu ◽  
Qiu-Gang Zong ◽  
Michel Blanc
Keyword(s):  
Magnetic Fields ◽  
Current Sheet ◽  
Power Law ◽  
Heavy Ions ◽  
Particle Interaction ◽  
The Other ◽  
Gaussian Functions ◽  
Fixed Energy ◽  
Thin Current Sheet ◽  
A Current

<p>Jupiter's magnetosphere contains a current sheet of huge size near its equator. The current sheet not only mediates the global mass and energy cycles of Jupiter's magnetosphere, but also provides an occurring place for many localized dynamic processes, such as reconnection and wave-particle interaction. To correctly evaluate its role in these processes, a statistical description of the current sheet is required. To this end, here we conduct statistics on Jupiter's current sheet, with four-year Juno data recorded in the 20-100 Jupiter radii, post-midnight magnetosphere. The results suggest a thin current sheet whose thickness is comparable with the gyro-radius of dominant ions. Magnetic fields in the current sheet decrease in power-law with increasing radial distances. At fixed energy, the flux of electrons and protons increases with decreasing radial distances. On the other hand, at fixed radial distances, the flux decreases in power-law with increasing energy. The flux also varies with the distances to the current sheet center. The corresponding relationship can be well described by Gaussian functions peaking at the current sheet center. In addition, the statistics show the flux of oxygen- and sulfur-group ions is comparable with the flux of protons at the same energy and radial distances, indicating the non-negligible effects of heavy ions on current sheet dynamics. From these results, a statistical model of Jupiter's current sheet is constructed, which provides us with a start point of understanding the dynamics of the whole Jupiter's magnetosphere.</p>

scholarly journals II. On the solvent power of liquid cyanogen

1872 ◽  
Vol 20 (130-138) ◽  
pp. 67-70 ◽  
Keyword(s):  
Copper Wire ◽  
The Other ◽  
Boiling Water ◽  
Small Fragment ◽  
Gutta Percha ◽  
Solvent Power

In the following experiments a number of stout tubes of refractory glass of the annexed shape were employed. Each tube was closed at one end, and had a flanged mouth at the other. The limb A was 11/2 inch long, the limb B 2 inches, and C 7 inches. In making the experiments, each tube was first filled, to an extent of 51/2 inches of its length, with highly dried crystals of mercuric cyanide; a small fragment of asbestus* was then pushed tightly against the end of the cyanide by means of a thin rod of gutta percha, and the bend of the tube cleaned by means of a slender brush. A number of taper plugs of gutta percha were previously made by softening, the end of a rod of that substance in boiling water and then chilling it ; and loops of thin copper wire were also prepared for the purpose of securing the plugs.

scholarly journals On the magnetic power of soft iron

1837 ◽  
Vol 3 ◽  
pp. 187-188
Keyword(s):  
Electric Current ◽  
Copper Wire ◽  
Complete Removal ◽  
The Other ◽  
Present Communication ◽  
Hard Steel ◽  
Electric Current Passing ◽  
Good Contact ◽  
The One ◽  
Single Helix

When free magnetism is developed by induction, and is not retained in that state by what has been termed the coercive force of hard steel, it has generally been considered that all the phenomena due to the existence of free magnetism cease on the removal of the inducing cause. The object of the present communication is to show that such is not the fact. From a variety of experiments described by the author, it appears that soft iron continued to exhibit strongly the attraction due to the developement of magnetism long after the means by which the magnetism had been originally excited had ceased to act. In these experiments, bars of soft iron, in the form of a horseshoe, had a single helix of copper wire wound round them, so that on the ends of the wire being brought into contact with the poles of a voltaic battery, the iron became an electromagnet. With one of these horse-shoes, while the connexion between the ends of the helix and the poles of the battery existed, the soft iron, having a keeper applied to its poles, supported 125 pounds it supported 56 pounds after that connexion had been broken, and continued to retain the power of supporting the same weight after an interval of several days, care having been taken not to disturb, during the time, the contact between the horse-shoe and its keeper. On this contact, however, being broken, nearly the whole attractive power appeared to be immediately lost. The author describes several instances of the same kind, particularly one in which the contact between the ends of the horse-shoe of soft iron and its keeper having been undisturbed during fifteen weeks, the attractive power continued undiminished. Although the interposition of a substance, such as mica or paper, between the ends of the horse-shoe and its keeper necessarily diminished the force of attraction, it did not appear to diminish the power of retaining that force. In a case where the electromagnet of soft iron and its keeper were equal semi-circles, the author found, what may appear singular, that the arrangement of the magnetism during the time that the electric current traversed the helix, appeared not to be the same as after the cessation of that current; in the one case similar, and in the other dissimilar, poles being opposed to each other at the opposite extremities of the two semi-circles. Whether the magnetism was originally developed in the soft iron by means of an electric current passing round it, or by passing over its surface the poles of an electromagnet, or those of a common magnet of hard steel, it appeared to possess the same power of retaining a large portion of the magnetism thus developed. The retention of the magnetism does not appear to depend upon the relative positions of the ends of the horse-shoe and the keeper remaining undisturbed, but on their contact remaining unbroken: for one keeper was substituted for another without diminution of this power; care being taken that the second should be in good contact with both ends of the horse-shoe before the complete removal of the first.

scholarly journals X-ray examination of certain copper-zinc alloys at elevated temperatures

1934 ◽  
Vol 145 (854) ◽  
pp. 258-267 ◽  
Keyword(s):  
Elevated Temperatures ◽  
Close Contact ◽  
Thin Sheet ◽  
Thin Foil ◽  
The Other ◽  
Copper Sheet ◽  
Zinc Alloys ◽  
Β Phase ◽  
Copper Zinc ◽  
Thermo Couple

This investigation is a continuation of the word on copper-zinc alloys reported in previous papers. Our previous measurements were made on quenched alloys, and it was assumed that the conditions prevailing at any temperature at the moment of quenching were retained in the quenched samples. In the present word an attempt is made to investigate the validity of this assumption by examining the alloys at the actual temperatures of annealing. Attention is directed mainly to the β-phase in tire pure region and in the mixed regions on either side of the pure phase. It was hoped that such measurements might also throw more light on the nature of the β-transformation. Apparatus and Method of Experiment . The precision camera was the same in principle as that previously used and described, with modifications in deign for high temperature word. It was made entirely of invar except that three silica rods connected the portion of the drum carrying the film to that carrying the sample. By this device the one part was well insulated thermally from the other. In order to take photographs in vacuo , the camera was fitted into a brass box with a removable lid and water-cooled sides; inside the box, the heater, consisting of "Kanthal" resistance wire embedded in alundum cement, was mounted. To hold the sample, which was in the form of fine filings on thin foil, against the camera frame, a thin sheet of copper foil was used. This was anchored with insulating porcelain beads and wire springs to the camera frame carrying the film. To minimize the heat passing from the sample to the camera frame, a thin sheet of mica of definite thickness was used around the slot over which the sample was placed. The sample was heated by bringing the heater, shaped to the contour of the camera frame, into close contact with a similarly shaped copper sheet about 1⋅5 mm. thick, into which the "hot" junction of one thermo-couple was silver-soldered; this in turn pressed against the foil on which the sample was mounted. Leads for the thermo-couple pyrometers—one to measure the approximate temperature of the sample photographed and the other to measure the camera temperature near tire film—passed through insulated plugs in one side of the box. On the opposite side, leads to the heater were similarly inserted. An outlet for exhausting the box completed the construction.

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