Determination of the field and the forces on a current filament moving above a conducting plate

1985 ◽  
Vol 68 (4) ◽  
pp. 293-298 ◽  
Author(s):  
S. M. Panas ◽  
E. E. Kriezis
1883 ◽  
Vol 35 (224-226) ◽  
pp. 44-48

Our attention has been directed for some time to a new determination of the atomic weight of manganese. This communication gives a succinct account of the results of the preliminary stages of such an inquiry, and although the further progress of the investigation may reveal some errors, still we feel convinced the final numbers can in no way differ materially from the present values, and therefore further delay in publication is unnecessary. The atomic weight of manganese has been determined by many chemists, but the resulting values vary considerably according to the special method selected. The results of the different investigators may be divided into two classes—those giving approximately 55 as the number, and those making it about 54. To the former class belong Turner, Berzelius, and Dumas, all of whom use the same method, viz., the determination of the silver chloride yielded by a weighed amount of chloride of manganese. Turner also made determinations from the analysis of the carbonate, and from the conversion of the monoxide into sulphate. Von Hauer used the same method as that employed by him in the determination of the atomic weight of cadmium, viz., the reduction of manganous sulphate to sulphide by ignition in a current of sulphuretted hydrogen. It is probable that this method is not very trustworthy, as, according to Schneider, the sulphide may be contaminated by oxysulphide. Schneider and Rawack belong to the second class of observers, the former employing the oxalate, and from its analysis calculating the atomic weight by deducting the weight of water and carbon dioxide obtained. Rawack, whose experiments were conducted in Schneider’s laboratory, weighed the water obtained by reducing manganoso-manganic oxide to manganous oxide.


Paleobiology ◽  
1981 ◽  
Vol 7 (3) ◽  
pp. 305-307 ◽  
Author(s):  
John C. Briggs

A current question being debated with considerable intensity is whether or not certain geographic areas act as centers of evolutionary radiation and supply species to other areas that are less active or less effective in an evolutionary sense. Darwin (1859) was the first to write about centers of origin which he called “single centers of creation.” He argued that each species was first produced within a single region and that it subsequently migrated from that area as far as its powers of migration and subsistence under past and present conditions permitted. Adams (1902), in discussing the influence of the southeastern United States as a center of distribution for the flora and fauna of North America, provided a series of criteria for the determination of “centers of dispersal.” His first, and evidently most important criterion was the location of “the greatest differentiation of a type.”


2021 ◽  
Vol 87 (9) ◽  
pp. 44-49
Author(s):  
D. A. Kuzmin

Discontinuities in the products that occur during manufacture, mounting or upon operation can be missed during non-destructive testing which do not provide their complete detectability at a current level of the technology. Therefore, it is necessary to take into account that certain structural elements may have discontinuities of significant dimensions. We present the results of using the methods of probability theory in studying the residual imperfections that remains in the structure after non-destructive control and repair of the previously identified defects. We used the results of operational control of units carried out by ultrasonic and radiographic methods. We present a method for determining a multifactorial coefficient that takes into account the detectability of defects, the number of control procedures and the errors in the instrumentation and methodological support, as well as a generalized equation for the probability distribution of detecting discontinuities. The developed approach provides assessing of the level of damage to the studied objects, their classification proceeding from the quantitative data and determination of the values of postulated discontinuities for deterministic calculations. The results obtained can be used to improve the methods of monitoring NPP facilities.


2020 ◽  
Vol 25 (3) ◽  
pp. 7-12
Author(s):  
Rud V.V. ◽  

This paper considers the problems of the integration of independent manipulator control systems. Areas of control of the manipulator are: recognition of objects and obstacles, identification of objects to be grasped, determination of reliable positions by the grasping device, planning of movement of the manipulator to certain positions with avoidance of obstacles, and recognition of slipping or determination of reliable grasping. This issue is a current problem primarily in industry, general-purpose robots, and experimental robots. This paper considers current publications that address these issues. Existing algorithms and approaches have been found in the management of both parts of the robot manipulator and solutions that combine several areas, or the integration of several existing approaches. There is a brief review of current literature and publications on the above algorithms and approaches. The advantages and disadvantages of the considered methods and approaches are determined. There are solutions that cover either some areas or only one of them, which does not meet the requirements of the problem. Using existing approaches, integration points of existing implementations are identified to get the best results. In the process, a system was developed that analyzes the environment, finds obstacles, objects for interaction, poses for grasping, plans the movement of the manipulator to a specific position, and ensures reliable grasping of the object. The next step was to test the system, test the performance, and adjust the parameters for the best results. The resulting system was developed by the research team of RT-Lions, Technik University, Reutlingen. The hardware research robot includes an Intel Realsense camera, a Sawyer Arm manipulator from Rethink Robotics, and an internally grabbing device.


2014 ◽  
Vol 32 (No. 3) ◽  
pp. 213-217 ◽  
Author(s):  
H. Bovšková ◽  
K. Míková ◽  
Z. Panovská

We compare visual evaluation of yolk colour estimated by the usual method applying La Roche scale with spectrophotometric determination of &beta;-carotene by AOAC method, and by new rapid analyser iCheck<sup>TM</sup> Egg photometer (BioAnalyt). The eggs under consideration were purchased on a current Czech market. The eggs originated from various countries and various types of breeding including some specialities. The yolk colour varied between the values of 4&ndash;13 of La Roche scale. The carotenoid content expressed as &beta;-carotene measured by AOAC method varied between 11&ndash;87 mg/kg. The carotenoid content expressed as &beta;-carotene measured with the analyser iCheck<sup>TM</sup> Egg photometer was lower and varied between 7.5&ndash;68.5 mg/kg. The correlation between the colour hue measured visually and the carotenoid content was not proved. Slovak eggs from cages which contained 28.3 mg carotenoids in 1 kg of yolk had the darkest yolks (value 13), Czech bio eggs which contained 20.2 mg carotenoids in 1 kg of yolk had the palest yolks (value 6). The highest content of carotenoids was found in eggs from home hen breeding (72.5 mg carotenoids in 1 kg of yolk) whose colour hue had the value of 10.


Chemosensors ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 14 ◽  
Author(s):  
Isabel Acevedo-Restrepo ◽  
Lucas Blandón-Naranjo ◽  
Jorge Hoyos-Arbeláez ◽  
Flavio Della Pelle ◽  
Mario Vázquez

The possibility of using an electrochemical biosensor, using screen-printed electrodes modified with a carbonaceous material and a commercial kit for the determination of glucose, to monitor an ethanolic fermentation was analyzed. The determination is based on the electrochemical oxidation reaction of NADH that occurs at a potential where the components of the kit do not generate a current signal, even in the presence of the fermentation medium. The electrochemical system was used to analyze the variation of glucose concentration during a laboratory-scale fermentation. The results were contrasted with the variation of standard characterization parameters such as pH, total soluble solids (TSS), the viability of the yeast, and concentration of ethanol produced. Of these values, the total soluble solids should be related to the concentration of glucose obtained by the electrochemical sensor, however, this last measure is more specific for sugar since the TSS refers to all soluble solids. The obtained results allow us to verify the usefulness of the electrochemical method for real-time monitoring of a fermentation.


A Current can be measured absolutely in the electro-magnetic system of units either by means of the action of the current on a magnet, or of the current on a current. The former method has the disadvantage that at least two independent measurements are necessary. For example, in using an electro-magnetic balance, the strength of the magnet acted on by the electric circuit has to be determined, as well as the force exerted on the magnet by the circuit. In galvanometers, either of the sine or tangent type, the magnetic field produced by the electric circuit is compared with the earth’s horizontal field, the strength of which is determined independently. Further, as the strength of artificial magnets cannot be regarded as truly constant, and the earth’s field is subject to diurnal and secular variations, this class of measurement is not ideal. In the electrodynamic class of measurement the mutual action between two or more coils carrying current takes the form of a torque, as in electrodynamometers, or a direct force, as in current weighers. In electrodynamometers the torque may be measured with a bifilar suspension, the torsion of a wire or spring, or by means of a gravity balance. Current weigher measurements are almost always made by direct comparison with gravity, which is believed to be constant, and is known to a higher degree of accuracy than the strengths of any magnet or magnetic field that has yet been measured.


Sign in / Sign up

Export Citation Format

Share Document