scholarly journals Optical characterization of ethane droplets in the vicinity of critical pressure

2020 ◽  
Vol 75 ◽  
pp. 59 ◽  
Author(s):  
Chanisa Kanjanasakul ◽  
Frédéric Grisch ◽  
Sawitree Saengkaew ◽  
Gérard Gréhan
Keyword(s):  
High Pressure ◽  
Refractive Index ◽  
Critical Point ◽  
Critical Pressure ◽  
Fuel Injection ◽  
Index Of Refraction ◽  
Fuel Droplets ◽  
Thermodynamic Conditions ◽  
Rainbow Refractometry

The characterization of the properties of fuel droplets around the critical pressure is an experimental challenge. The aim of this study is to measure the size and the refractive index of droplets in high pressure conditions, close to the ones of the critical point. For this purpose, an experimental facility of injection of quasi-monodispersed droplets at high pressure has been developed. Rainbow refractometry has been used to probe droplets in the pressure range 1–50 bar. For water and ethanol droplets, evolutions of their index of refraction with pressure were obtained. For measurements with a liquid fluid near its critical point, ethane was selected because its critical point is 48.7 bar and 32.2 °C. Refractive index measurements on ethane droplets were carried out in the range of pressure and temperature 40–46 bar and 18–25 °C respectively. These unique results show that the rainbow refractometry diagnosis offers undeniable potentials for studying fuel injection under transcritical thermodynamic conditions.

TEM characterization of proton-exchanged LiNbO3 optical waveguides

1986 ◽  
Vol 44 ◽  
pp. 480-481
Author(s):  
W. E. Lee
Keyword(s):  
Refractive Index ◽  
Benzoic Acid ◽  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Index Of Refraction ◽  
Optical Measurements ◽  
Lithium Ions ◽  
Wide Channel ◽  
Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

Characterization of Photo-Cvd Silicon Oxide

1987 ◽  
Vol 101 ◽  
Author(s):  
R. Padmanabhan ◽  
B. J. Miller ◽  
N. C. Saha
Keyword(s):  
Refractive Index ◽  
Auger Electron ◽  
Silicon Oxide ◽  
Index Of Refraction ◽  
Film Stress ◽  
Process Conditions ◽  
Film Composition ◽  
Vapor Deposition Technique ◽  
Photochemical Vapor Deposition

ABSTRACTA photochemical vapor deposition technique was used to deposit silicon oxide films. A range of film properties was produced through changes in the process conditions. Refractive index, indicative of film composition, varied from 1.5 to 2.0, corresponding to oxygen rich and silicon rich conditions, respectively. Etch rate in buffered HF was a strong function of the refractive index, with higher index of refraction yielding lower rates. Film stress was tensile and the magnitude of the stress was again related to the index of refraction. Other properties that were evaluated included pinhole density and adhesion to Si. All the properties were directly relatable to the basic film composition.X-ray photo electron and Auger electron spectroscopy were used to characterize the composition of these films. The Si 2p photoelectron and the Si KLL Auger electron spectra were broad for higher refractive index films and upon deconvolution indicated the presence of different silicon containing species, the natures of which depended upon the actual index of refraction. For stoichiometric films, the predominant constituent was SiO2 and for non-stoichiometric films, varying amounts of Si2O, SiO, Si2O3 and SiO2 were all present.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Polyvinylidene Fluoride ◽  
Wide Band ◽  
High Refractive Index ◽  
Wide Band Gap ◽  
Optical Film

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals 3D characterization of individual grains of coexisting high-pressure H2O ice phases by time-domain Brillouin scattering

2021 ◽  
Vol 130 (5) ◽  
pp. 053104
Author(s):  
Sathyan Sandeep ◽  
Théo Thréard ◽  
Elton De Lima Savi ◽  
Nikolay Chigarev ◽  
Alain Bulou ◽  
...  
Keyword(s):  
High Pressure ◽  
Time Domain ◽  
Brillouin Scattering ◽  
Individual Grains
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