scholarly journals A method to perform float-and-sink test for separation of coal samples of various densities and determination of ‘Probable Error’ and ‘Imperfection’

IOP SciNotes ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 024403
Author(s):  
Sushobhan Pradhan ◽  
Satyabrata Mohanta
Keyword(s):  
Probable Error

MEASUREMENT OF γ-RAY DIFFRACTION ANGLES TO ± 0.02 SECOND OF ARC WITH A DOUBLE FLAT CRYSTAL SPECTROMETER

1962 ◽  
Vol 40 (2) ◽  
pp. 237-256 ◽  
Author(s):  
J. W. Knowles
Keyword(s):  
Optical Method ◽  
Probable Error ◽  
Precision Measurements ◽  
Crystal Spectrometer ◽  
Optical Geometry ◽  
Relative Angle ◽  
Precision Determination ◽  
Γ Ray

An optical method is described for the precision determination of the relative angle between the diffraction planes of two crystals of a double flat crystal spectrometer. An angular precision, probable error ± 0.02 second of arc, is achieved. Measurement of relative angles are made by reference to a standard ruled scale. Absolute angles are determined by combining these measurements with measurements of the optical geometry. The factors which influence the precision measurements are discussed in detail. It is concluded that γ-ray energies between 0.5 and 2 Mev can be compared with a precision of a few parts in 105.

scholarly journals Determination of constituents receipt Kakhovka Reservoir water balance

2017 ◽  
pp. 209-214
Author(s):  
O.S. Koryagina
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Water Balance ◽  
Practical Importance ◽  
Surface Flow ◽  
Probable Error ◽  
Scientific Interest ◽  
Reservoir Water ◽  
Surface Water Flow

The study of the reservoirs is of great scientific interest and is of practical importance for the solution of problems of rational use and protection of water resources. The paper describes the latest reservoir in the cascade of Dnipro Kakhovka Reservoir and its component of water balance. The methods of determining the components of the water balance that were once offered the Kakhovka  hydrometeorological observatory are submitted. Great attention is drawn to the surface flow of water into the reservoir from unexplored rivers, which is determined by the method of analogy. The probable error of this method, in turn, is equal to for monthly values 30-50% and annual – 10-20%. So, there is provided somewhat different a method for determining the surface flow using the curve of security component amount of annual precipitation, maps of the norm runoff and tables SNiP 2.01.14.83. The proposed method simplifies and accelerates the process of calculating the amounts of surface water flow in unexplored rivers to Kakhovka reservoir.

SMITHSONIAN SOLAR CONSTANT VALUES

1925 ◽  
Vol 6 (7) ◽  
pp. 96-96
Author(s):  
H. H. Kimball
Keyword(s):  
Probable Error ◽  
Monochromatic Radiation ◽  
Critical Study ◽  
Solar Constant ◽  
Outer Limit ◽  
The Past ◽  
Order Of Magnitude ◽  
Probable Effect ◽  
The Mean

A critical study of the values published during the past 20 years leads to profound respect for the skill, energy, and devotion to science evidenced in connection with their determination. The mean of these values is generally accepted as correct within the limits of the accuracy of the observations. This paper has to do principally with the two following sources of error, and their probable effect upon the day-to-day variations in the solar constant values:(1) Pyrheliometer readings. Numerous comparisons between different instruments indicate a probable error in the readings of one, provided both are equally good, of about ±0.30 per cent. For Montezuma, Chili, Dr. Abbot computes the error to be ±0.20 per cent, and since a solar constant value depends upon the readings of two instruments, the error would be onlyThis enters directly into the determination of the solar constant values.(2) The difficulties of extrapolating pyrheliometer readings to the outer limit of the atmosphere, which is accomplished through determinations of atmospheric transmissibility for monochromatic radiation, (a), by the bolometer, or (b) by the pyranometer. An examination of individual determinations made at Montezuma and Harqua Hala on days having not less than 6 determinations at the two stations, gives probable errors of from ±0.2,3 per cent to ±0.74 per cent, and the day-to-day variability seems to be a function of the number of determinations upon which the daily values are based. Since the probable error, or the probable variability, in the day-to-day values of the solar constant derived from determinations at these two stations is less than ±0.5 per cent, it is seen that solar variability, if it exists, is of the same order of magnitude as the probable error of the determinations. Therefore, this fact must be taken into account in attempting to correlate solar constant values with weather and other phenomena.

ESTIMATION OF REDUCING SUGARS IN STARCH HYDROLYZATES BY PAPER CHROMATOGRAPHY

1950 ◽  
Vol 28b (9) ◽  
pp. 527-534 ◽  
Author(s):  
Ping Shu
Keyword(s):  
Quantitative Determination ◽  
Paper Chromatography ◽  
Chromatographic Separation ◽  
Reducing Sugars ◽  
Reducing Power ◽  
Probable Error

A method for quantitative determination of glucose, maltose, and reducing dextrins in starch hydrolyzates is described. The components are separated by paper chromatography and determined colorimetrically by measurement of their reducing power with alkaline copper and arseno-molybdate reagents. The probable error of the determinations with the use of this method is about 2%. A compact apparatus was designed, suitable for handling a large number of samples in the chromatographic separation. It is particularly useful for compounds with low Rf values.

scholarly journals II. On the construction of some mercury standards of resistance, with a determination of the temperature coefficient of resistance of mercury

1905 ◽  
Vol 204 (372-386) ◽  
pp. 57-120 ◽  
Keyword(s):  
Electrical Measurement ◽  
National Physical Laboratory ◽  
Probable Error ◽  
Electrical Measurements ◽  
Temperature Coefficient Of Resistance ◽  
Cross Sectional ◽  
Object A ◽  
Physical Laboratory ◽  
Long Time

According to the Order in Council of August 23, 1894, by which certain fundamental electrical units were made legal— “The ohm which has the value 10 9 in terms of the centimetre, and the second of time, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice, 14.4521 grammes in mass, of a constant cross-sectional area, and of a length 106.3 centims.,” is one of the units of electrical measurement on which “denomination of standards required for use in trade” is to be based. The establishment of the National Physical Laboratory rendered it possible to realize this unit in England. With this object, a number of selected tubes of “Verre dur” were obtained from M. Baudin, with the kind assistance of the officials of the Bureau International, while others of Jena 16'" glass were procured from Messrs. Schott and Co., Jena. The work, however, has necessarily occupied a long time. With the increasing accuracy of electrical measurements it appeared desirable to determine the constants of the tubes so that the probable error should not exceed 1 part in 100,000. Preliminary observations of various kinds were essential to secure success, while the work of organising the various departments of the Laboratory also tended to delay matters; hence it was not until the autumn of 1902 that the real start was made.

scholarly journals Further investigations with a Wilson Chamber. III.—The accuracy of the angle determination

1932 ◽  
Vol 136 (829) ◽  
pp. 338-348 ◽  
Keyword(s):  
Energy Levels ◽  
Probable Error ◽  
Average Error ◽  
Mass Ratio ◽  
Angle Measurements ◽  
Mass Ratios ◽  
Calculated Mass ◽  
The Difference ◽  
Error Of Measurement

I.—The question of the precision of the determination of the angles of forked tracks is of considerable importance, in particular owing to the possibility of determining nuclear energy levels from Wilson photographs. In an earlier paper some experiments were described in which an artificial track consisting of a bent glass fibre was photographed in different positions. The average error of determination of the angle was found to be 10 minutes of arc. This error was attributed to the lack of perfect adjustment of the camera. That the error of measuring actual tracks could be nearly as small as this was shown by measurements of three collisions in which the difference between the calculated and expected mass ratios was consistent with a probable error of about 10 minutes of arc for the angle measurements. Only such forks were used for these calculations of the mass ratio, for which the three arms appeared unusually straight and for which the test for coplanarity was accurately satisfied. Subsequently two collisions with hydrogen nuclei were described in which the error of the angles was held to be as low as 6 minutes of arc. It was pointed out at the time that many tracks did not, in fact, satisfy these conditions, but sufficient data were not then available for a statistical analysis of the distribution of calculated mass ratios, from which a reliable estimation of the probable error of measurement of an average fork could be made. Since then a great many more photographs have been taken with a larger chamber and an improved camera and such a statistical test is now possible. To test the camera itself five photographs were taken of two black lines ruled on a card. The angles calculated from the photographs were:—

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