scholarly journals Analysis of the scheme of grinding of paraboloid rotation surface by the "knife" method

2018 ◽  
pp. 666-671
Author(s):  
V.A. Zverev ◽  
Yu.S. Nikolaeva ◽  
I.N. Timoshchuk
Keyword(s):  
Rotation Surface

Propagation and Reflection of Plane Waves in a Rotating Magneto-Elastic Fibre-Reinforced Semi Space with Surface Stress

2020 ◽  
Vol 22 (4) ◽  
pp. 939-958
Author(s):  
Indrajit Roy ◽  
D. P. Acharya ◽  
Sourav Acharya
Keyword(s):  
Surface Stress ◽  
Incident Angle ◽  
Plane Waves ◽  
Three Dimensional ◽  
Elastic Fibre ◽  
Amplitude Ratios ◽  
Governing Equations ◽  
Rotation Surface ◽  
Wave Velocities ◽  
Magnetic Field Rotation

AbstractThe present paper investigates the propagation of quasi longitudinal (qLD) and quasi transverse (qTD) waves in a magneto elastic fibre-reinforced rotating semi-infinite medium. Reflections of waves from the flat boundary with surface stress have been studied in details. The governing equations have been used to obtain the polynomial characteristic equation from which qLD and qTD wave velocities are found. It is observed that both the wave velocities depend upon the incident angle. After imposing the appropriate boundary conditions including surface stress the resultant amplitude ratios for the total displacements have been obtained. Numerically simulated results have been depicted graphically by displaying two and three dimensional graphs to highlight the influence of magnetic field, rotation, surface stress and fibre-reinforcing nature of the material medium on the propagation and reflection of plane waves.

scholarly journals Characterization of rocky exoplanets from their infrared phase curve

2010 ◽  
Vol 6 (S276) ◽  
pp. 485-486
Author(s):  
Anne-Sophie Maurin ◽  
Franck Selsis ◽  
Franck Hersant ◽  
Marco Delbò
Keyword(s):  
Thermal Emission ◽  
Infrared Emission ◽  
Phase Curve ◽  
Low Mass Stars ◽  
Rotation Surface ◽  
Key Population ◽  
Short Period ◽  
Low Mass ◽  
Observation Geometry

AbstractDuring the last few years, observations have yielded an abundant population of short-period planets under 15 Earth masses. Among those, hot terrestrial exoplanets represent a key population to study the survival of dense atmospheres close to their parent star. Thermal emission from exoplanets orbiting low-mass stars will be observable with the next generation of infrared telescopes, in particular the JWST. In order to constrain planetary and atmospheric properties, we have developed models to simulate the variation of the infrared emission along the path of the orbit (IR phase curve) for both airless planets and planets with dense atmospheres. Here, we focus on airless planets and present preliminary results on the influence of orbital elements, planet rotation, surface properties and observation geometry. Then, using simulated noisy phase curves, we test the retrieval of planets' properties and identify the degeneracies.

Electrohydrodynamic Kelvin-Helmholtz Instability of Two Rotating Dielectric Fluids

1998 ◽  
Vol 53 (1-2) ◽  
pp. 17-26
Author(s):  
Mohamed Fahmy El-Sayed
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Rotation Frequency ◽  
Short Wave ◽  
Surface Charges ◽  
Rotation Surface ◽  
Dielectric Fluids ◽  
Fluid Velocities ◽  
Conditions Of Stability

Abstract A linear stability analysis of a novel electrohydrodynamic Kelvin-Helmholtz system consisting of the superposition of two uniformly rotating dielectric media is presented. The characteristic equation for such an arrangement is derived, which in turn yields a stability criterion for velocity differences of disturbances at a given rotation frequency. The conditions of stability for long and short wave perturbations are obtained, and their dependence on rotation, surface tension and applied electric field is discussed. Limiting cases for vanishing fluid velocities, rotation frequency, and applied electric field are also discussed. Under suitable limits, results of previous works are recovered. A detailed analysis for tangential and normal applied electric fields, in the presence and absence of surface charges, is carried out.

Surface Analysis of Radial Lip Seals With Deterministic Micro Cavities on the Shaft

2007 ◽  
Author(s):  
Lyndon Scott Stephens ◽  
Katherine Warren
Keyword(s):  
Functional Groups ◽  
Surface Analysis ◽  
Surface Parameter ◽  
Rotation Surface ◽  
Surface Parameters ◽  
Lip Seal ◽  
Pumping Effect ◽  
Lip Seals ◽  
Areal Surface ◽  
Reverse Pumping

Many approaches have been used to control the reverse pumping effect in radial lip seals. One of those is the use of oriented triangular micro-asperities on the shaft of the seal. This extended abstract presents areal surface parameter measurements from a lip seal with triangular micro-cavities oriented towards the direction of rotation. Surface parameters in the roughness, hybrid and functional groups are presented. The measurements are then discussed and placed in the context of radial lip seal performance.

scholarly journals The Relationship between the Structure and Properties of Amino Acid Ionic Liquids

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3252 ◽  
Author(s):  
Paula Ossowicz ◽  
Joanna Klebeko ◽  
Barbara Roman ◽  
Ewa Janus ◽  
Zbigniew Rozwadowski
Keyword(s):  
Amino Acids ◽  
Ionic Liquids ◽  
Amino Acid ◽  
Surface Activity ◽  
Spectroscopic Properties ◽  
Specific Rotation ◽  
Structure And Properties ◽  
Rotation Surface ◽  
Cation Type ◽  
The Relationship

Ionic liquids based on different l-amino acids (glycine, l-valine, l-leucine, l-isoleucine, l-histidine, l-methionine, l-tyrosine, l-tryptophan, l-arginine, and l-threonine) and different cations (tetrabutylammonium (TBA), tributylmethylammonium (tBMA), didecyldimethylammonium (DDA), (2-hydroxyethyl)trimethylammonium (choline) (Chol), alkyl(C12-C14) dimethylbenzylammonium (benzalkonium) (BA), dodecyltrimethylammonium (DDTMA), hexadecyltrimethylammonium (HDTMA), octadecyltrimethylammonium (ODTMA) and 1-ethyl-3-methylimidazolium (EMIM)) have been synthesized and characterized by NMR and FTIR. Viscosity, specific rotation, surface activity, thermal stability (TG), and phase transformations (DSC) have been determined and compared with available data. Furthermore, benzalkonium, didecyldimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, and octadecyltrimethylammonium amino acid ionic liquids have been shown to exhibit surface activity. The dissolution of cellulose in amino acid ionic liquids (AAILs) composed of various cations was also investigated. Cellulose was only dissolved in EMIM salts of amino acids. In particular, the influence of the cation type on selected physicochemical and spectroscopic properties were discussed. The article is a mini review on amino acid ionic liquids.

scholarly journals Nonlinear rotating viscoelastic jets during forcespinning process

2018 ◽  
Vol 474 (2220) ◽  
pp. 20180346 ◽  
Author(s):  
Daniel N. Riahi
Keyword(s):  
Surface Tension ◽  
Strain Rate ◽  
Tensile Force ◽  
Arc Length ◽  
Rotation Surface ◽  
Speed Increase ◽  
Nonlinear Viscoelastic ◽  
Steady Solutions ◽  
Effects Of Rotation ◽  
Viscoelastic Jets

In the usual forcespinning (FS) process, a fluid jet is forced through an orifice of a rotating spinneret leading to the formation of a jet with curved centreline. In this paper, we investigate the properties of nonlinear viscoelastic jets during the FS process. We apply scaling and perturbation techniques to determine the modelling system for the viscoelastic jets, subjected to the Giesekus constitutive equations for the stress tensor. We calculate numerically the expressions for the nonlinear steady solutions for the jet quantities such as radius, speed, stretching rate, strain rate, tensile force and trajectory. We determine these quantities for different values of the parameters such as those representing the effects due to rotation, surface tension, viscosity, jet drag and viscoelasticity. We find, in particular, that the fibre jet radius decreases and the tensile force increases with the jet arc length as well as with increasing the effects of rotation and viscoelasticity. Both viscosity and surface tension indicate stabilizing effect on the viscoelastic jet. In addition, strain rate, stretching rate and the jet speed increase with the arc length, viscoelasticity and rotation rate.

Titan's Rotation: Surface Feature Observed

Icarus ◽  
1993 ◽  
Vol 103 (2) ◽  
pp. 329-332 ◽  
Author(s):  
Mark T. Lemmon ◽  
Erich Karkoschka ◽  
Martin Tomasko
Keyword(s):  
Surface Feature ◽  
Rotation Surface

A Fast Approach to Obtain High-Precision Measurement of the Minimum Circumscribed Cylinder Using Computer Drawing

2014 ◽  
Vol 625 ◽  
pp. 3-8
Author(s):  
Wei Fang Chen ◽  
Jui Te Chang
Keyword(s):  
Quality Assessment ◽  
High Precision ◽  
Measurement Data ◽  
Outer Edge ◽  
Assessment Model ◽  
High Precision Measurement ◽  
Rotation Surface ◽  
Cylindrical Shaft ◽  
Edge Quality ◽  
Drawing Method

Roundness and spindle error motion measurements are two fundamental issues in the geometrical measuring techniques. Most of the fixture with rotating cylindrical shaft, cylinder defined by the minimum circumscribed axis, can be obtained the minimum circumscribed rotation surface high-precision axis. Generally, a more accurate measurement points, can result in a more accurate cylindrical shaft, but the longer the time of the calculation time. In this paper, the drawing method can handle a large number of measurement data to avoid lengthy and complicated calculations, and can quickly obtain the minimum circumscribed cylindrical axis precise location, deviation and cylindrical radius and tolerance. This article is the use of the minimum circumscribed cylinder theoretical approach with computer drawing ways. Comparison is relatively quick and easy. The actual display of the results, which can be easily, obtained the position, skew and deviation of the spindle. This paper will be established a cylindrical outer edge quality assessment model and provided a basis for the cylindrical outer edge quality assessment. This paper for seeking the axis of cylindrical shank is based on minimum circumscribed cylindrical theory with computer drawing method and instances for verification. The computer drawing method can be determined spindle eccentric angle and the distance of deviation, to provide a reliable model for the evaluation of rotary spindle, the mode established by the paper at the same time applicable to any other rotating spindle error evaluation.

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