Close‐coupled and coupled‐states calculation of shear viscosity SBE cross sections for the H2–He system

1982 ◽  
Vol 76 (10) ◽  
pp. 5112-5127 ◽  
Author(s):  
W.‐K. Liu ◽  
F. R. McCourt ◽  
D. E. Fitz ◽  
D. J. Kouri
Keyword(s):  
Cross Sections ◽  
Shear Viscosity

Modelling of Shear Viscosity Behavior and Extrusion through Dies for Rubber Compounds

1987 ◽  
Vol 60 (2) ◽  
pp. 337-360 ◽  
Author(s):  
James L. White ◽  
Yeh Wang ◽  
Avraam I. Isayev ◽  
Nobuyuki Nakajima ◽  
Frederick C. Weissert ◽  
...  
Keyword(s):  
Cross Sections ◽  
Shear Viscosity ◽  
Flow Analysis ◽  
Elongational Flow ◽  
Extrudate Swell ◽  
Pressure Losses ◽  
Analysis And Design ◽  
Rubber Compounds ◽  
Viscosity Behavior ◽  
Active Research

Abstract This paper marks a first effort to develop a fundamental basis for die flow analysis and design for rubber compounds. We have accomplished a modelling of the shear viscosity function and its application to one- and two-dimensional shearing in die cross sections. There are major limitations in what we have done, much of which is apparent even in the early work of Mooney. In particular, we have not considered (i) slip phenomena on die walls, (ii) die entrance and exit pressure losses associated with converging and diverging dies, nor (iii) extrudate swell. We have an active research in our laboratories investigating these problems. In the future, we are seeking to generalize the procedures described in this paper to more complex die designs. Inclusion of entrance and exit effects and rigorous analysis of coathanger dies requires the handling of elongational flow contributions, a still unsolved problem.

Production and relaxation cross sections for the shear viscosity SBE. II. IOSA results for the N2–He system

1981 ◽  
Vol 75 (3) ◽  
pp. 1496-1508 ◽  
Author(s):  
W.‐K. Liu ◽  
F. R. McCourt ◽  
D. E. Fitz ◽  
D. J. Kouri
Keyword(s):  
Cross Sections ◽  
Shear Viscosity

Senftleben-Beenakker Effects, Nonresonant Absorption and Collision Integrals for Gases Consisting of Symmetrie Top Molecules

1974 ◽  
Vol 29 (2) ◽  
pp. 299-305
Author(s):  
H. Moraal
Keyword(s):  
Distribution Function ◽  
Cross Section ◽  
Cross Sections ◽  
Shear Viscosity ◽  
Tensor Polarization ◽  
Collision Integrals ◽  
Model Calculations ◽  
Dipole Moment Operator ◽  
Moment Operator ◽  
Function Density

The kinetic theories of the electric and magnetic Senftleben-Beenakker effects and of nonresonant absorption in polar symmetric top gases are reviewed, using an expansion of the distribution function-density matrix which includes the dipole moment operator μe . General expressions are given for the elastic parts of all collision integrals coupling two purely angular momentum dependent tensors. This is done for a variety of nonspherical potentials, including the dipole-dipole (DD), dipole-quadrupole (DQ) and quadrupole-quadrupole (QQ) interactions. Model calculations for the m ethyl halogenides are performed for these potentials for a number of collision integrals, namely the nonresonant cross section and three collision cross sections which are of importance for the shear viscosity Senftleben-Beenakker effects. These calculations indicate that DD, DQ and QQ interactions may all be important, that at least half of the nonresonant cross section is elastic and that the average cross section extracted by means of Levi’s theory from electric field shear viscosity Senftleben-Beenakker measurements is approximately equal to the reorientation cross section for the tensor polarization [μe](2).

scholarly journals Shear viscosity of hadrons withK-matrix cross sections

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
Anton Wiranata ◽  
Volker Koch ◽  
Madappa Prakash ◽  
Xin Nian Wang
Keyword(s):  
Cross Sections ◽  
Shear Viscosity

scholarly journals Shear viscosity to electrical conductivity ratio in the quasiparticle models

2020 ◽  
Vol 229 (22-23) ◽  
pp. 3487-3496
Author(s):  
Valeriya Mykhaylova
Keyword(s):  
Electrical Conductivity ◽  
Cross Sections ◽  
Shear Viscosity ◽  
Relaxation Times ◽  
Conductivity Ratio ◽  
Transport Parameters ◽  
Strange Quarks ◽  
Effective Masses ◽  
Relaxation Time Approximation ◽  
Quasiparticle Model

AbstractWe examine the temperature dependence of the shear viscosity η to electrical conductivity σ ratio, as well as the specific shear viscosity and the scaled electrical conductivity in QCD with light and strange quarks. Our calculations are performed in kinetic theory under the relaxation time approximation combined with the quasiparticle model. We compute all transport parameters using the isotropic and transport cross sections and compare our results to a class of quasiparticle models for the QGP with Nf = 2 + 1. The results depending on different schemes are examined. The ratio (η∕s)∕(σ∕T) quantifies the relation between the relaxation times of gluons and quarks and specifies their comparative role in the evolution of the QGP. We find an excellent agreement with the (η∕s)∕(σ∕T) ratio deduced from the dynamical quasiparticle model in which the quasiparticles are characterized not only by their effective masses but also by finite widths.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

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