scholarly journals Physico-chemical determinations at high pressures by optical methods

1912 ◽  
Vol 87 (594) ◽  
pp. 152-153
Keyword(s):  
High Pressures ◽  
Rotatory Power ◽  
Optical Measurements ◽  
Optical Methods ◽  
Refractive Index Dispersion ◽  
Double Refraction ◽  
Axial Angle ◽  
Physico Chemical ◽  
Polarised Light ◽  
Pressure Bomb

Apparatus for Optical Measurements at High Pressures . The apparatus consists of three chief units:— (1) Plant for the production and measurement of pressures up to 4000 kgrm./cm. 2 . (2) A “pressure-bomb” to hold the substances under investigation. (3) An optical bench for observations in polarised light, and for measurements of the change of refractive index, dispersion, rotatory power, absorption, double-refraction and optical-axial-angle, by pressure.

scholarly journals IV. Physico-chemical determinations at high pressures by optical methods

1913 ◽  
Vol 212 (484-496) ◽  
pp. 117-148 ◽  
Keyword(s):  
High Pressures ◽  
Optical Observations ◽  
Optical Methods ◽  
Small Glass ◽  
Physico Chemical ◽  
Glass Tubes ◽  
Pressure Bomb ◽  
The Subject ◽  
Transition Points

In the course of his well-known investigations concerning the compressibility of gases and liquids, Amagat made some series of measurements taking observations through two small glass windows fitted to his high-pressure bomb (“méthode des regards”),* and he also twice made an attempt to use a similar arrangement for the determination of melting and crystallization at high pressures. His first paper on these subjects deals with the melting and with the formation of two different kinds of crystals of carbon tetrachloride. The highest pressure employed was 1,160 atmospheres. The second paper, in which a somewhat different arrangement of the glass windows was used, deals with the crystallization of ice at temperatures below zero under the influence of high pressures.^ In a summarizing paper Amagat§states that he occasionally was able to reach pressures of about 1,600 atmospheres before the glass windows were broken, but observations were not actually made at higher pressures than 1,000 atmospheres. In this paper a sketch of the apparatus is also given. Amagat states that he met with severe difficulties during these investigations, and he has not pursued the subject further. Later melting-points and transition-points of some “liquo-crystalline” substances have been measured in Jena glass tubes up to 300 atmospheres by Hullett, and other optical observations at pressures above that of the atmosphere have been made by Rothmund (maximum 500 atmospheres), Röntgen and Zehnder, Sierstema, Liveing and Dewar, Hutton and Petavel,§§ and Duffield, but in these investigations the pressures have, as a rule, not exceeded 100 atmospheres.

scholarly journals VIII. On the Optical Properties of Muriate of Soda, Fluate of Lime, and the Diamond, as exhibited in their action upon Polarised Light

1818 ◽  
Vol 8 (1) ◽  
pp. 157-164 ◽  
Author(s):  
David Brewster
Keyword(s):  
Optical Properties ◽  
Double Refraction ◽  
Polarised Light

It has long ago been remarked by the Abbé Hauy, that the property of Double Refraction is not possessed by any of those crystals the form of whose integrant molecule is distinguished by its symmetry, such as the Cube and the Regular Tetraedron. This class of minerals comprehends Fluate of Lime, Muriate of Soda, Spinelle Ruby, Muriate of Ammonia, Alum and the Diamond; and though M. Hauy had examined only a very small number of doubly refracting crystals, yet, with the exception of the Diamond, which I have found in many cases to possess the property of Double Refraction, his remark was confirmed by the experiments of Malus, Biot and myself, who considered all the crystals of this class as exercising no more action upon polarised light than a mass of water.

scholarly journals Physico-chemical studies of complex organic molecules. III.―Surface properties of concentrates of vitamin A

1934 ◽  
Vol 116 (796) ◽  
pp. 27-37
Keyword(s):  
Vitamin A ◽  
Surface Properties ◽  
High Pressures ◽  
Surface Film ◽  
General Behaviour ◽  
Air Interface ◽  
Physico Chemical ◽  
Chemical Studies ◽  
Long Chain Alcohol ◽  
Complex Organic

At present little is known of the surface properties of vitamin A or of carotene. Such knowledge can be useful in determining the shape, size, and chemical structure of these molecules. It is also possible that a knowledge of the surface behaviour of the molecules may help to throw light on the mechanism by which they are carried and are effective in the animal body. The first part of this paper describes the properties of a surface film of a concentrate of vitamin A at a water/air interface. This concentrate spread readily on clean water to form an insoluble film of the liquid expanded type; the film remained liquid under high pressures and the general behaviour resembled that of a long chain alcohol. The surface film was oxidized by air with a diminution in the surface area. Carotene did not spread on water.

scholarly journals Briquettes Production from Olive Mill Waste under Optimal Temperature and Pressure Conditions: Physico-Chemical and Mechanical Characterizations

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1214 ◽  
Author(s):  
Saaida Khlifi ◽  
Marzouk Lajili ◽  
Saoussen Belghith ◽  
Salah Mezlini ◽  
Fouzi Tabet ◽  
...  
Keyword(s):  
High Pressures ◽  
Corn Starch ◽  
Applied Pressure ◽  
Heating Value ◽  
Industrial Plants ◽  
High Heating Value ◽  
Physico Chemical ◽  
Olive Mill Solid Waste ◽  
Temperature And Pressure ◽  
Olive Mill

This paper aims at investigating the production of high quality briquettes from olive mill solid waste (OMSW) mixed with corn starch as a binder for energy production. For this purpose, different mass percentages of OMSW and binder were considered; 100%-0%, 90%-10%, 85%-15%, and 70%-30%, respectively. The briquetting process of the raw mixtures was carried out based on high pressures. Physico-chemical and mechanical characterizations were performed in order to select the best conditions for the briquettes production. It was observed that during the densification process, the optimal applied pressure increases notably the unit density, the bulk density, and the compressive strength. Mechanical characterization shows that the prepared sample with 15% of corn starch shows the best mechanical properties. Moreover, the corn starch binder affects quietly the high heating value (HHV) which increases from 16.36 MJ/Kg for the 100%-0% sample to 16.92 MJ/Kg for the 85%-15% sample. In addition, the kinetic study shows that the binder agent does not affect negatively the thermal degradation of the briquettes. Finally, the briquettes characterization shows that the studied samples with particles size less than 100 μm and blended with 15% of corn starch binder are promising biofuels either for household or industrial plants use.

Räumliches und zeitliches Auflösungsvermögen kohärenter und inkohärenter Lichtquellen / Spatial and Temporal Resolution of Coherent and Incoherent Light Sources

1977 ◽  
Vol 32 (9) ◽  
pp. 1007-1014
Author(s):  
E. Häusler ◽  
D. Warken
Keyword(s):  
Spatial Resolution ◽  
Temporal Resolution ◽  
Acoustic Pressure ◽  
Optical Measurements ◽  
Optical Methods ◽  
Physical Parameters ◽  
Light Sources ◽  
Moving Targets ◽  
Incoherent Light ◽  
Thermal Light

AbstractSpatial and Temporal Resolution of Coherent and Incoherent Light Sources The spatial resolution of optical methods using lasers is much higher than those using thermal light sources. The temporal resolution of optical methods with lasers for the measurement of the time dependence of physical parameters (velocity of moving targets, elasto-optical measurements of mechanical quantities, e. g. stress, acoustic pressure) is limited by their strong noise, exceeding the noise of thermal light sources by orders of magnitudes. It is shown that in applications with little requirements on the spatial resolution and temporal coherence the SNR will be greater if thermal light sources are used.

THE SPACE-GROUP OF POTASSIUM DITHIONATE

1931 ◽  
Vol 4 (6) ◽  
pp. 565-569 ◽  
Author(s):  
W. H. Barnes ◽  
G. V. Helwig
Keyword(s):  
Polarized Light ◽  
Rotatory Power ◽  
Quarter Wave Plate ◽  
Double Refraction ◽  
Space Group ◽  
X Ray ◽  
Single Cross ◽  
Quarter Wave ◽  
Crystal Class ◽  
Axis Rotation

An X-ray investigation of the space-group of potassium dithionate is described.Approximate measurements of refractive indices and specific rotatory power were in harmony with those obtained by Groth. From Laue photographs and the fact of optical activity, the crystal class is trigonal trapezohedral, in agreement with crystallographic data.The crystals showed the single cross and circular concentric rings characteristic of uniaxial crystals when plates perpendicular to the c axis were examined under crossed Niçois in convergent polarized light. The sign of the double refraction as determined with a quarter-wave plate was positive.The primitive translations of the unit cell, determined from the a axis and c axis rotation photographs were: a0, 9.77 Å; c0, 6.28 Å, and a:c = 1:0.644. The number of molecular units per cell was found to be three. It is deduced that the lattice must be hexagonal (Γh.) From the fact that no abnormal spacings of {0001} were observed, the space-group of potassium dithionate is shown to be either [Formula: see text] or [Formula: see text].

Optical Investigation of Profile Losses in a Linear Turbine Cascade

2010 ◽  
Author(s):  
Olga Alhaj ◽  
Joerg R. Seume
Keyword(s):  
Measurement Techniques ◽  
Turbine Blades ◽  
Estimation Method ◽  
Optical Measurements ◽  
Optical Methods ◽  
Flow Visualisation ◽  
Optical Investigation ◽  
Flow Conditions ◽  
Optical Techniques ◽  
Dimensional Flow

Two or three dimensional flow visualisation is an active research field because of its non-intrusiveness. However, its application is often restricted to ideal laboratory conditions. Only few of the multi-dimensional flow visualization techniques have been developed into quantitative measurement techniques which are applicable to turbo machinery flow conditions. This paper demonstrates the application of completely optical measurements for the estimation of the loss coefficient of turbine blades in a linear cascade wind tunnel, which represents flow conditions close to the real but geometrically simplified and therefore more accessible. Two optical means were combined for this purpose. To determine the velocity field of the wake, two-component Particle Image Velocimetry (PIV) was employed. Tomographical Background Oriented Schlieren method (BOS), using 8 cameras placed in 180° around the cascade, was used for measuring a 3-D density field in the wake. For purposes of comparison, the traditional loss estimation method with 5-hole pressure probes accompanied the optical methods. Inlet parameters were measured with a Prandtl probe and a temperature sensor. The optical techniques are, once they are installed as in the present work, much faster than any other conventional method, e.g. pneumatic probes. Moreover, optical techniques can be used for investigation of transient flows.

Influence of active admixtures onto tellurite glass refractive index

2010 ◽  
Vol 58 (4) ◽  
pp. 519-522 ◽  
Author(s):  
M. Reben ◽  
J. Wasylak ◽  
J. Jaglarz
Keyword(s):  
Refractive Index ◽  
Rare Earth ◽  
Spectral Dependence ◽  
Tellurite Glass ◽  
Thermal Characteristic ◽  
Rare Earth Ions ◽  
Optical Measurements ◽  
Glass Crystallization ◽  
Physico Chemical ◽  
Thermal Stability Of

Influence of active admixtures onto tellurite glass refractive index The goal of this work was to investigate the influence of rare earth ions such as Tm3+, Yb3+ on physico-chemical properies of tellurite glass from the TeO2-WO3-PbO-PbF2-Na2O system. The thermal characteristic of tellurite glass Tm3+, Yb3+ doped have been presented. The effect of the glass crystallization on thermal stability of the glass and crystallizing phases formed upon heat treatment were investigated by DTA/DSC/, XRD methods. The spectral dependence of ellipsometric angles of the tellurite glass samples, have been studied. The influence of ions of rare earth elements, i.e. Tm3+ and Yb3+, onto changes of refractive index of glass P1 (without RE admixture) were examined. The optical measurements were conducted on Woollam M2000 spectroscopic ellipsometer, in spectral range of 190-1700 nm.

scholarly journals XIII. On a New Species of Double Refraction, accompanying a remarkable Structure in the Mineral called Analcime

1826 ◽  
Vol 10 (1) ◽  
pp. 187-194
Author(s):  
David Brewster
Keyword(s):  
New Species ◽  
Great Difficulty ◽  
Double Refraction ◽  
Primitive Form ◽  
Polarised Light ◽  
A New Species

The Mineral called Analcime or Cubizite has been ranked by Haüy among those crystals which have the Cube for their primitive form; an opinion which has been adopted by all succeeding mineralogists. No distinct cleavage-planes, however, so far as I can learn, have been observed in it. Crystallographers presumed that such planes must exist, and, allowing conjecture to supply the place of observation, they considered Analcime as differing in no respect from other crystals of the same series. This opinion was first rendered doubtful by the observation, that at thicknesses of of an inch, it displayed a considerable action upon polarised light; but though, from the tessular form of the mineral, this fact indicated something singular in its organization, yet, owing to the great difficulty of obtaining proper specimens, I have been baffled in repeated attempts to investigate its structure.

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