Experimental values for P wall, x and P repl, E for five parallel-plate, ion chambers-A new analysis of previously published data

1992 ◽  
Vol 19 (2) ◽  
pp. 367-367 ◽  
Author(s):  
Franca T. Kuchnir ◽  
Chester S. Reft
Keyword(s):  
Parallel Plate ◽  
Published Data ◽  
Ion Chambers ◽  
Experimental Values

scholarly journals Amplitude of Sunspot-Dependent Radiocarbon Variations: Data from Corals and Wine

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 111-115
Author(s):  
Mordeckai Magaritz ◽  
Israel Carmi ◽  
Ziv Sirkes
Keyword(s):  
Theoretical Analysis ◽  
Theoretical Calculation ◽  
Production Rate ◽  
Sunspot Cycle ◽  
Published Data ◽  
Earth Surface ◽  
The Earth ◽  
Surface System ◽  
Experimental Values

It has been suggested that the sunspot cycle modulates the production rate of radionuclides in the atmosphere and that these modulations can be traced in various parts of the earth surface system. On the basis of a theoretical analysis, Damon, Sternberg, and Radnell (1983) have concluded that the effects of the 11-yr cycle of sunspots should be observable in 14C data provided the measurements are done at a 2 permil (sd) level. This conclusion is based on calculations using models discussed by Lingenfelter and Ramaty (1970) and by O'Brien (1979) and on the 14C inventory modified from Damon, Lerman, and Long (1978). In this note we compare the amplitude estimate of Damon, Sternberg, and Radnell (1983), who calculated a representative peak-to-peak variation of 1.7‰ in 14C for the sunspot cycle between 1848 and 1856, with experimental values derived from recently published data. We find the experimental value to be larger by a significant factor from the theoretical calculation.

Elastic Deformation and Molecular Weight in Polyisobutylene

1946 ◽  
Vol 19 (4) ◽  
pp. 1047-1050
Author(s):  
John Rehner
Keyword(s):  
Molecular Weight ◽  
Parallel Plate ◽  
Compressive Load ◽  
Published Data ◽  
Fractional Powers ◽  
Rapid Procedure ◽  
Molecular Weights ◽  
High Elasticity ◽  
Polymer Dissolution ◽  
Straight Lines

Abstract Although various properties of high polymers are known to depend on molecular weight, there appear to be no published data which show explicitly how the molecular weight of a rubber-like substance influences the modulus of high elasticity, even though a psychological perception of some such relationship has long existed. Also, the various expressions that have been derived by statistical methods contain molecular weight as a factor ranging from an inverse first power up to inverse higher fractional powers. Some time ago a need arose in this laboratory for estimating the average molecular weights of samples of polyisobutylene by a rapid procedure. Because of the slowness of polymer dissolution, methods based on measurements of the polymer in the dissolved state had to be ruled out and an investigation was, therefore, made of the rate of compression of a variety of samples in a Williams parallel-plate plastometer. It was found possible to render negligible the viscous component of deformation by using a sufficiently high compressive load and by limiting readings to an interval of about one minute. When the observed deformation values were plotted against the logarithm of time, straight lines were obtained. The slopes of the lines could be correlated, at least approximately, linearly with the reciprocal average molecular weights of the samples.

The Viscosity of Methane

1967 ◽  
Vol 7 (01) ◽  
pp. 75-79 ◽  
Author(s):  
Mario H. Gonzalez ◽  
Richard F. Bukacek ◽  
Anthony L. Lee
Keyword(s):  
Physical Properties ◽  
Capillary Tube ◽  
Test Fluid ◽  
Spectrometric Analysis ◽  
Accurate Information ◽  
Published Data ◽  
Viscosity Data ◽  
Experimental Conditions ◽  
Temperature And Pressure ◽  
Experimental Values

Abstract Experimental viscosity data for methane are presented for temperatures from 100 to 340F and pressures from 200 to 8,000 psia. A summary is given of the available date for methane, and a comparison is presented for that data common to the experimental range reported in this paper. Correlation of the data is presented, and predicted values are given for temperatures up to 460F and pressures up to 10,000 psia. Introduction The increasing ranges of temperature and pressure at which fluids are produced, transferred and processed in the petroleum and chemical industries stress the need for accurate information on physical properties, both for engineering calculation and for improving the methods used to estimate physical properties. A survey of the literature reveals that disagreements between published data on the viscosity of methane are common and that most investigations have been conducted over restricted temperature and pressure ranges. This situation made it desirable to undertake an investigation with a scope common to most of the literature data available. APPARATUS AND MATERIALS The apparatus used in this investigation was the capillary tube viscometer described by Dolan, with modifications introduced in the general design and operation of the instrument. It has an effective pressure range from 14.7 to 10,000 psia and a temperature range from room temperature to 400F. The design of the viscometer is based on the establishment of a manometric head between two vessels containing the test fluid and a volume of mercury. The reservoirs are connected by a capillary tube through which the test fluid flows and a tube through which mercury flows. A pressure gradient is established by elevating one of the vessels above the other, the resulting flow of mercury displacing the test fluid through the capillary. The schematic diagram of the system (Fig. 1) shows the arrangement of the equipment auxiliary to the viscometer. The density cells assembly (E, Fig. 1) was not used in this investigation since reliable data are available on methane. The assembly consists of a bank of eight 316 stainless steel pycnometers. Experimental values of the density of a natural gas and i-butane samples have been obtained for pressures up to 8,000 psia and temperatures up to 340F. The methane used was obtained from the Southern California Gas Co. Mass spectrometric analysis showed a composition of 99.8 percent CH4, 0.1 percent C2H6 and 0.1 percent C3H8. EXPERIMENTAL VALUES AND ACCURACY OF DATA Determinations were carried out at several temperatures. With the temperature in the cabinet controlled at a given level, a series of runs were made at various pressures. To establish pressures lower than that obtained from the methane cylinder, it was necessary to vent the gas slowly to the atmosphere until the desired pressure was reached. The consistency of the test run time for a particular condition can be used as a criterion for the accuracy of the data. A further check is obtained by comparison of the viscosity values obtained using different driving heads. To establish the instrument's reproducibility, a large number of runs were made at three completely different conditions of temperature and pressure. Data obtained were analyzed statistically to determine the most reliable value for the variance of the experimental data. It was found that the variances of the data taken at different experimental conditions were not statistically equivalent, but they were small. The largest variance was found at 8,000 psia and 100F, where the standard deviation was 0.385 micropoise. Therefore, 99.9 percent of the data can be expected to fall within 1.15 micropoises of the population mean, except fm the intervention of systematic errors in operation. JPT P. 75ˆ

scholarly journals EP-1446: Can parallel plate ion chambers be used for PDD measurements in FFF beams?

2017 ◽  
Vol 123 ◽  
pp. S771-S772
Author(s):  
S. Vargas Castrillón ◽  
F. Cutanda
Keyword(s):  
Parallel Plate ◽  
Ion Chambers

DETERMINATION OF EFFECTIVE DISTRIBUTION COEFFICIENT OF IMPURITIES DURING ZONE REFINING OF TELLURIUM

2008 ◽  
Vol 22 (16) ◽  
pp. 2583-2588 ◽  
Author(s):  
D. S. PRASAD ◽  
N. R. MUNIRATHNAM ◽  
J. V. RAO ◽  
T. L. PRAKASH
Keyword(s):  
Distribution Coefficient ◽  
Solute Concentration ◽  
Published Data ◽  
Zone Refining ◽  
Translation Rate ◽  
Refining Efficiency ◽  
Experimental Values ◽  
Effective Distribution Coefficient ◽  
Effective Distribution

Knowledge of distribution coefficient values is essential in estimating the refining efficiency, and plays an important role during the purification process, typically zone refining. The effective distribution coefficient "K eff " of impurities Se , Fe , Cr and Pb in tellurium was determined in the present study and found to be 0.48, 0.05, 0.25 and 0.19, respectively. The results are validated by comparing with the available published data, and we observed a difference of less than one order, which was reasonably comparable. The influence of "K eff " on zone refining efficiency was examined and it was noticed that the effective distribution coefficient increases with respect to the translation rate, which is minimum at an optimum lower translation rate (= 30 mm/h ). The relative solute concentration C/C0 is determined experimentally, which shows the best fit of experimental values with Pfann's equation. The impurity profile along the length of the zone refined ingot is also discussed.

Response of Parallel‐Plate Ion Chambers to Radiation Pulses

1964 ◽  
Vol 35 (8) ◽  
pp. 2341-2348
Author(s):  
Peter M. Livingston
Keyword(s):  
Parallel Plate ◽  
Ion Chambers
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