A Simple Instrument for the Direct Determination of Dielectric Constants of Liquids over a Wide Range of Values.

1963 ◽  
Vol 35 (13) ◽  
pp. 2161-2164 ◽  
Author(s):  
P. P. Maloney ◽  
R. N. Smith
Keyword(s):  
Direct Determination ◽  
Dielectric Constants ◽  
Wide Range ◽  
Simple Instrument ◽  
Range Of Values

scholarly journals Field and Laboratory-based Approach for the Determination of Friction Angle of Geological Discontinuities of Malaysian Granites

2011 ◽  
Vol 28 (2) ◽  
pp. 151 ◽  
Author(s):  
R. A Ghani ◽  
T. L Goh ◽  
A. M Hariri ◽  
Y. N Baizura
Keyword(s):  
Friction Angle ◽  
Roughness Coefficient ◽  
Average Value ◽  
Peak Friction Angle ◽  
Maximum Value ◽  
Wide Range ◽  
Discontinuity Surfaces ◽  
Geological Discontinuities ◽  
Range Of Values

The basic friction angle, Φb for artificially sawn discontinuity planes for fresh granite, as determined by tilt testing, has an average value of 30º. For the natural rough discontinuity surfaces, a wide range of values have been determined for the peak friction angle, Φpeak ranging from 47º to a maximum value of 80º, depending on the joint roughness coefficient (JRC). The average values of the friction angles for the different degrees of roughness were as follows: JRC 2–4 = 58°; JRC 6–8 = 60°; JRC 8–10 = 47°; JRC 12–14 = 60°; JRC 14–16 = 71° ; JRC 18–20 = 80°.

scholarly journals A new method for effective dose calculation based on the ambient dose height distribution

2017 ◽  
Vol 3 (2) ◽  
pp. 147-149
Author(s):  
Mario Liebmann ◽  
Niroojiny Sangarapillai ◽  
Björn Poppe ◽  
Heiner von Boetticher
Keyword(s):  
Effective Dose ◽  
Direct Determination ◽  
Dose Calculation ◽  
Gender Effects ◽  
Height Distribution ◽  
Wide Range ◽  
Personal Dosimetry ◽  
And Gender ◽  
Ambient Dose

AbstractThe realistic determination of effective dose of the staff in diagnostic radiology has been a challenge both for personal dosimetry and ambient dose measurement. A model for dosimetry of occupational exposure is presented that allows direct determination of effective dose from measured or even manufacturer given ambient dose distribution in front of the personnel. This model considers a wide range of radiation energies, different radiation protection situations, and gender effects.

Experimental determination of thermal conductivity of composite materials in a wide range of values at room temperature

2019 ◽  
Author(s):  
A.N. Chistov ◽  
M.Yu. Kladov ◽  
I.B. Pronin ◽  
A.S. Smirnov
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Room Temperature ◽  
Measurement Procedure ◽  
Thermal Mode ◽  
Wide Range ◽  
Measurement Results ◽  
Transfer Problems ◽  
Range Of Values

In developing new composite materials and solving heat transfer problems, the thermal conductivity is an important characteristic that must be reliably determined. This often requires samples of the smallest dimensions, which is relevant for the production of pilot batches of material, as well as if they are taken directly from the product, when the amount of material is very limited. Most common methods for determining thermal conductivity require samples of relatively large sizes. To measure thermal conductivity on small-sized samples, an upgraded benchtop instrument is introduced. The instrument uses the relative method of longitudinal heat flux, which consists in a comparative measurement of a sample located between the heater and the standard in a stationary thermal mode. This paper presents the instrument design details, the requirements for the samples, explains the calibration features and the measurement procedure. The measurement results in a number of composite materials, as well as in materials with well-studied properties are analyzed. Findings show that the error of determining the thermal conductivity on a modernized instrument does not exceed several percent.

scholarly journals On the direct determination of the electrostatic moments of molecules

1929 ◽  
Vol 124 (795) ◽  
pp. 689-698 ◽  
Keyword(s):  
Dielectric Constant ◽  
Direct Determination ◽  
Negative Temperature ◽  
Dielectric Constants ◽  
Temperature Coefficients ◽  
Different Temperatures

According to Faraday's ideas, the specific inductive capacity of a substance is due to the polarisation of the molecules as wholes. This is the basis of the old Clausius-Mosotti theory of dielectrics, on which it is shown first that the polarisation P is proportional to the polarising field, i. e. , P = k E, k being the dielectric constant, and second that δ being the density of the dielectric, k - 2/ k + 2 ·1/δ = constant. Now it is known that some substances have large negative temperature coefficients for their dielectric constants which cannot thus be accounted for. To provide for this Debye proposed the theory that the molecules were permanently polarised and that they were systematically orientated in the field. This leads to the equation k - 2/ k + 2 = a T -1 + b T -2 , to represent the change of specific inductive capacity with temperature. This theory has been developed by Gans and others, and a number of measurements have been made by Smyth and others, who have found the molecular moments of many substances by measuring the dielectric constants at different temperatures.

scholarly journals A critical experimental investigation of the "force" method of determining the dielectric capacity of conducting liquids at low frequencies: Univalent electrolytes in aqueous solution

1936 ◽  
Vol 157 (891) ◽  
pp. 359-372 ◽  
Keyword(s):  
Dielectric Constant ◽  
Accurate Determination ◽  
Direct Determination ◽  
Alternating Current ◽  
Liquid Dielectric ◽  
Dielectric Constants ◽  
Polar Molecules ◽  
Low Frequencies ◽  
Force Method

The theories of Debye, Onsager, and Falkenhagen, stressing the connexion between the dielectric constant and the other properties of solutions of electrolytes, have focussed a considerable amount of attention on the problem of the accurate determination of the dielectric properties of conducting solutions. The results, however, of work published by various investigators during the past few years show wide discrepancies and, in fact, it can hardly be said that even the sign of the effect of electrolytes upon the dielectric constant of water has yet been established with any degree of certainty. That the results have been so unsatisfactory is not altogether surprising in view of the inherent difficulties of the problem; the system itself is a complicated one, consisting of simple water dipoles, the polymers dihydrol and trihydrol, and the solute molecules or ions dispersed throughout the liquid; furthermore, the experimental technique is frequently complicated by the requirement that the dielectric constants shall be determined at frequencies low enough to permit of computation of the maximum possible polarization of the system, including the rotational polarization of all polar molecules which may be present. Methods involving the direct determination of the capacity of a condenser containing the liquid, whether by capacity-bridge or by resonance, are rendered difficult or inaccurate through the poor capacity sensitivity of such systems in presence of an appreciable ohmic conductivity between the condenser plates. This difficulty is minimized by the use of very high frequencies, and a considerable amount of work has been carried out under these conditions by Wien, Röver, Falkenhagen, and others in connexion with the theory of strong electrolytes. The need has arisen, however, for the values of the dielectric constants of solutions of large polar molecules such as long-chained amino acids, polypeptides, and soluble proteins. Such substances have considerably enhanced periods of relaxation, and proportionately low frequencies of alternating current must be employed to avoid loss of the orientation polarization of the system. In the case of pure egg-albumin solution, dispersion of hertzian waves occurs at all frequencies above about 10 5 sec. -1 . In view of this difficulty it seemed desirable that a thorough investigation should be made into the question as to whether precision results might be obtained from some general method which uses comparatively low frequencies of alternating current. The “force” method theoretically developed by Fürth, in 1924, seemed the most promising. Various modifications of this method have been used by many workers, unfortunately, however, with by no means concordant results, so far as conducting solutions are concerned. It consists broadly in the determination of the force exerted upon an ellipsoid, mounted to rotate about one of its minor axes, in a liquid dielectric across which an alternating field is applied in a direction at right angles to the axis of rotation of the ellipsoid. For such a system Fürth has shown that the torque on the ellipsoid may be expressed by εE 2 sin2θA, where ε represents the dielectric constant of the liquid, E the potential gradient, θ the angle between the major axis of the ellipsoid and the direction of the field, and A a constant involving the dimensions of the ellipsoid. This form of Fürth’s equation applies only so long as the resistance of the liquid dielectric is high relative to that of the ellipsoid itself.

Free Molecule Flow Through a Vacuum Seal

1970 ◽  
Vol 92 (3) ◽  
pp. 405-410
Author(s):  
H. S. Yu ◽  
E. M. Sparrow
Keyword(s):  
Mass Flow ◽  
Numerical Solutions ◽  
Rarefied Gas ◽  
Coupled System ◽  
Mass Fluxes ◽  
Wide Range ◽  
Flow Through ◽  
Molecule Flow ◽  
Range Of Values

An analysis is made of the rate of the mass flow through a vacuum seal separating two rarefied gas environments. The determination of the mass throughflow characteristics involves the formulation and solution of a coupled system of six integral equations. The formulation is performed using the methods of kinetic theory. Numerical solutions are carried out for a wide range of values of the seal geometrical parameter. Mass flow results evaluated from these solutions are presented graphically. In addition, representative distributions of the mass fluxes at the participating surfaces are given.

Elemental Speciation Measurements with Electrospray Mass Spectrometry: An Assessment

1994 ◽  
Vol 48 (11) ◽  
pp. 1347-1359 ◽  
Author(s):  
George R. Agnes ◽  
Ian I. Stewart ◽  
Gary Horlick
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Molecular Form ◽  
Direct Determination ◽  
Organometallic Compounds ◽  
Ionic Species ◽  
Elemental Speciation ◽  
Wide Range ◽  
Inorganic Complexes

Electrospray mass spectrometry (ES-MS) is shown to be suited for the direct determination of ionic species in solution. Examples used in this investigation of ES-MS for elemental speciation determinations included several inorganic ionic species of chlorine, iodine, sulfur, and iron. These species were differentiated on the basis of differences in the molecular form and/or the oxidation state of the analyte ion. The inorganic complexes of silver-cyanide and iron-fluoride were also measured in this assessment. Finally it is shown that ES-MS is applicable to the determination of organometallic compounds. While ES-MS is not an ideal speciation technique, there is considerable evidence to indicate that ES-MS can become an invaluable tool with which species distributions in a wide range of sample types may be probed.

Improved Methods for the Prediction of Chatter in Turning, Part 2: Determination of Cutting Process Parameters

1990 ◽  
Vol 112 (1) ◽  
pp. 21-27 ◽  
Author(s):  
I. E. Minis ◽  
E. B. Magrab ◽  
I. O. Pandelidis
Keyword(s):  
Cutting Force ◽  
Metal Cutting ◽  
Transfer Functions ◽  
Direct Determination ◽  
Base Plate ◽  
Cutting Process ◽  
Input Output ◽  
Wide Range ◽  
Improved Methods

The dynamics of the metal cutting process are identified by a new and simple experimental method that permits the direct determination of the cutting transfer functions from input-output measurements. A specially designed stiff force dynamometer rigidly mounted to the machine tool’s turret is used for the measurement of the cutting force. An external force is applied to the base plate of the dynamometer in such a way that the meaurements of both the tool’s displacement and the corresponding cutting force are uncoupled from the influence of the machine tool structure’s dynamics. The cutting transfer functions are obtained in the vicinity of the structure’s first resonance, under a wide range of cutting conditions.

scholarly journals Determination of the Degree of Homogeneity for n Ge Crystals by Measurements of Magnetoresistance in Classically Weak Magnetic Fields

2015 ◽  
Vol 16 (3) ◽  
pp. 469-474
Author(s):  
G. P. Gaidar ◽  
P. I. Baranskii
Keyword(s):  
Spatial Distribution ◽  
Magnetic Fields ◽  
Crystallographic Orientation ◽  
Qualitative Assessment ◽  
Weak Magnetic Fields ◽  
Wide Range ◽  
The Relationship ◽  
Range Of Values ◽  
Degree Of Heterogeneity

In a wide range of values of the resistivity 0.0212 £ r £ 35 Ohm×cm for n‑Ge crystals with known crystallographic orientation the ratio , which was predicted by the theory, was experimentally confirmed. The experimentally measured deviations from the relationship , which are associated with the heterogeneity of the crystals, it is proposed to use for qualitative assessment of the degree of heterogeneity in the spatial distribution of dopants in the samples.

Extraction concentrating of the acid-soluble forms of rare earth elements from oils of the Volga-Ural oil and gas province using rotating coiled columns

2021 ◽  
Vol 87 (12) ◽  
pp. 5-10
Author(s):  
E. Yu. Savonina ◽  
O. N. Katasonova ◽  
T. A. Maryutina
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Oil And Gas ◽  
Direct Determination ◽  
Soluble Form ◽  
Rotating Coiled Columns ◽  
Wide Range

Trace elements in oils are the natural markers of the oil origin of and the mechanism of oil genesis. Direct determination of rare earth elements (REE) in crude oils is rather difficult due to their low concentrations (10–6 wt. %). Information about the forms of trace elements in oils is of particular interest. The goal of the study is determination of the content of acid-soluble forms of REE in oils from various fields of the Volga-Ural oil and gas province. Six samples of oils of heavy and medium density and viscosity were analyzed. Extraction of acid-soluble forms of REE was carried out using rotating coiled columns in 0.5 M aqueous solution of nitric acid. Toluene was used to dilute the oils up to the necessary values of the density and viscosity providing the possibility of extraction in the system aqueous acid solution – oil. The content of REE was determined by inductively coupled plasma mass spectrometry on an Agilent 7900 spectrometer. Their content in an acid-soluble form in oil samples under study ranged within 172 – 2173 ng/kg. Such a wide range of values is attributed to the difference in the geology and age of deposit formation. The highest content of acid-soluble forms of REE (2173 ng/kg) was observed in the oil sample from the Novo-Elkhovsky field, whereas the lowest value (172 ng/kg) was measured in the oil sample of the Pioneer field. It is shown that the content of acid-soluble forms of REE depends on tectonic zoning, productive horizons and layers, as well as on the physical and chemical properties of oils. The distribution of acid-soluble forms of light and heavy REE was evaluated. Most of the REE (75 – 99%) determined in the analyzed oil samples are light REE. It is noted that systematization of the data on the properties of oils, geological and geochemical characteristics of the deposits will provide reliable forecasting of the various forms of REE present in oils.

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