Properties of Ebonite. XXIX. The Absorption Spectrum of Ebonite

1949 ◽  
Vol 22 (1) ◽  
pp. 231-232
Author(s):  
E. H. Dock ◽  
B. D. Porritt ◽  
W. H. Willott
Keyword(s):  
Absorption Spectrum ◽  
Present Note ◽  
Wave Length ◽  
Thin Sheet ◽  
Practical Interest ◽  
Inert Gas ◽  
Long Wave ◽  
Absorption Of Light ◽  
Molten Sulfur ◽  
Deposited Film

Abstract The absorption spectrum of ebonite has some practical interest, because the absorption of light causes the surface to deteriorate. A knowledge of the absorption spectrum should help in discovering which are the harmful rays. Published information hitherto appears to be limited to radiation of long wave length, i.e., thermal or infrared. The present note describes experiments on rubber-sulfur (65:35 or 68:32) compositions vulcanized for about 5 hours at 155° C. Owing to the great opacity of ebonite, it is necessary to work with very thin specimens. Various methods of obtaining these suggest themselves: (1) grinding down a small thin sheet; (2) cutting thin shavings; (3) vulcanizing as of a thin film between glass or quartz plates; (4) vulcanizing a film of rubber, deposited on glass or quartz, by immersion in molten sulfur; (5) vulcanizing a deposited film of a rubber-sulfur mix by heating in an inert gas. Methods (1), (2) and (5) have so far been found the most satisfactory. In method (2) it is advantageous to soften the material by swelling, e.g., in nitrobenzene; the swelling liquid can then be removed by extraction with a volatile solvent. Methods (1) and (2) have the advantage of enabling specimens to be obtained from larger pieces that can be analyzed or submitted to other tests.

scholarly journals On the absorption of light by crystals

1938 ◽  
Vol 167 (930) ◽  
pp. 384-391 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Wave Length ◽  
Short Wave ◽  
Point Of View ◽  
Theoretical Point ◽  
Lattice Vibrations ◽  
Short Wave Length ◽  
Continuous Absorption ◽  
Absorption Of Light ◽  
Positive Hole

The purpose of this paper is to discuss the absorption of light by non-metallic solids, and in particular the mechanism by which the energy of the light absorbed is converted into heat. If one considers from the theoretical point of view the absorption spectrum of an insulation crystal, one finds that it consists of a series of sharp lines leading up to a series limit, to the short wave-length side of which true continuous absorption sets in (Peierls 1932; Mott 1938). In practice the lattice vibrations will broaden the lines to a greater of less extent. When a quantum of radiation is absorbed in the region of true continuous absorption, a free electron in the conduction band and a "positive hole" are formed with enough energy to move away from one another and to take part in a photocurrent within the crystal. When, however, a quantum is absorbed in one of the absorption lines , the positive hole and electron formed do not have enough energy to separate, but move in one another's field in a quantized state. An electron in a crystal moving in the field of a positive hole has been termed by Frenkel (1936) an "exciton".

Wave Forces on a Stationary Platform of Elliptical Shape

1973 ◽  
Vol 17 (02) ◽  
pp. 61-71
Author(s):  
H. S. Chen ◽  
C. C. Mei
Keyword(s):  
Diffraction Problem ◽  
Wave Length ◽  
Practical Interest ◽  
Vertical Cylinder ◽  
Present Theory ◽  
Wave Forces ◽  
Mathieu Functions ◽  
Body Type ◽  
Elliptical Cross ◽  
Long Wave

Exciting forces and moments due to plane incident waves on a stationary platform are studied in this paper. The platform is a vertical cylinder with a finite draft and elliptical cross section. The mathematical solution to the diffraction problem is obtained on the basis of the linearized long wave approximation. Numerical results via Mathieu functions are presented for a shiplike body with beam-to-length ratio Various draft-to-depth ratios and angles of incidence are considered. Results have been checked with the limiting case of a circular cylinder for the long-wave length range. Aside from its own practical interest, the present theory provides a basis for comparison with other approximate theories of slender-body type and serves as a prelude to the corresponding calculations for arbitrary wavelengths.

scholarly journals Study the Effect of solvent on the Optical Properties Performance of active polymeric laser media

2007 ◽  
Vol 4 (3) ◽  
pp. 387-392
Author(s):  
Baghdad Science Journal
Keyword(s):  
Absorption Spectrum ◽  
Pure Water ◽  
Wave Length ◽  
Blue Shift ◽  
Short Wave ◽  
Fluorescence Yield ◽  
Effect Of Solvent ◽  
Long Wave ◽  
Short Wave Length ◽  
Laser Media

The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.72) at the same thickness & concentration of the sample.

The absorption spectrum of liquid bromine

1937 ◽  
Vol 162 (910) ◽  
pp. 414-419 ◽  
Author(s):  
D. Porret ◽  
Frederick George Donnan
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Ground State ◽  
Wave Length ◽  
Electronic States ◽  
Excited Electronic States ◽  
Long Wave ◽  
Liquid Bromine ◽  
Continuous Absorption ◽  
The Continuum

The continuous absorption spectra of gaseous bromine (Peskow 1917; Ribaud 1919; Gray and Style 1929; Acton, Aikin and Bayliss 1936) and of dissolved bromine (Bovis 1929; Gillam and Morton 1929) have been studied many times. They present a wide continuum (from about 30, 000 to 17, 000 cm. -1 .) with a maximum at 24, 000 cm. -1 . For the gas the continuum is preceded by two band systems on the long wave-length side. These systems converge at 19, 585 and 15, 896 cm. -1 . respectively. Acton, Aikin and Bayliss (1936) have shown that the continuum is not simple, and Mulliken (1936) and Darbyshire (1937) have pointed out that there are three overlapping continua corresponding to transitions from the ground state to three different excited electronic states. There are 3 II 0 + ← 1 Σ g , 3 II 1 ← 1 Σ g and 1 II ← 1 Σ g . The absorption spectrum of liquid bromine has been studied by Bovis (1929) form 18, 525 to 31, 750c cm. -1 . and by Camichel (1893) for two frequencies only (16, 978 and 18, 691 cm. -1 ).

scholarly journals On the absorption spectrum of sulphur trioxide and the heat of dissociation of oxygen

1932 ◽  
Vol 137 (832) ◽  
pp. 366-372 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Wave Length ◽  
Continuous Light ◽  
Mass Action ◽  
Appreciable Change ◽  
Long Wave ◽  
Continuous Absorption ◽  
Quartz Spectrograph ◽  
Sulphur Trioxide ◽  
Heat Of Dissociation

Much work has been done by different workers on the heat of dissociation of oxygen and in the present work I have tried to determine this value from the continuous absorption spectrum of SO 3 -vapour. Experiment .-The absorption spectrum of the sulphur trioxide vapour was obtained with a hydrogen discharge tube as the source of continuous light. The photograph was taken on a Leiss quartz spectrograph. The SO 3 -vapour was prepared by distilling pure fuming sulphuric acid, the gas thus obtained being collected in a glass absorption tube, fitted with quartz ends. The ab­sorption was found to be continuous, beginning from the long wave-length ca . λ 3300, with no trace of bands which could be assigned to SO 3 , just as in the case of saturated halides. Different lengths of the tube as well as different pressures were tried with no appreciable change in the position of the long wave-length limit. As the SO 3 -vapour is normally partly dissociated into SO 2 and O 2 , generally some bands of the SO 3 gas appear. These can be easily eliminated by comparison with the absorption spectrum of SO 2 . But it is possible to eliminate the SO 2 bands from the plate by putting an excess of oxygen in the absorption chamber, and then filling it up with SO 3 -vapour. According to the law of mass action the partial pressure of SO 2 is very con­siderably reduced by the addition of O 2 , hence the bands due to SO 2 are expected to become weakened: this was found to be the case.

Das UV/VIS-Absorptionsspektrum des 9.9′-Dianthryl-disulfids / The UV /VIS Absorption Spectrum of 9,9′-Dianthryl disulphide

1979 ◽  
Vol 34 (5) ◽  
pp. 664-666 ◽  
Author(s):  
M. Zander ◽  
R. B. Zellerhoff
Keyword(s):  
Absorption Spectrum ◽  
Wave Length ◽  
Vibrational Structure ◽  
Electronic Transitions ◽  
The Third ◽  
Long Wave

Abstract9,9′-Dianthryl disulphide is the first example studied for a diaryl disulphide whose uv/vis absorption spectrum exhibits a distinct vibrational structure whereas the formerly investigated spectra of diphenyl disulphide and the isomeric dinaphthyl disulphides are characterized by the complete lack of vibrational structure. Different interpretations have been given in the literature for this particular property of the diphenyl disulphide and dinaphthyl disulphide spectra. The long wave-length region of the dianthryl disulphide spectrum is interpreted with the assumption of three electronic transitions. Two of them are localized in the anthracene or dithio anthracene chromophore, respectively, whereas the third transition is assumed to be non-localized including the whole system with the S-S bridge acting as a conjugative (butadienoid) link. This assignment is consistent with a pπ-model without pπ/dπ-participation in agreement with results of photoelectron spectral investigations on disulphides reported in the literature.

scholarly journals The vibrational analysis of the absorption spectrum of lead sulphide

1935 ◽  
Vol 148 (863) ◽  
pp. 157-170 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Absorption Band ◽  
Vapour Pressure ◽  
Wave Length ◽  
Vibrational Analysis ◽  
Maximum Temperature ◽  
General Description ◽  
Lead Sulphide ◽  
Long Wave ◽  
Band Spectra

Band spectra due to the oxides of many elements are well known, but as yet little is known about the spectra of the sulphides of the same elements. Especially is this true of the sulphides of the metals, for up to the present only one, germanium sulphide, has been reported, A search for the absorption band spectra of the sulphides of the related elements, tin and lead, resulted in the discovery of two very extensive spectra, the first lying in the region λ 2600-λ 4500 and the second in the region λ 3100- λ 8000. A general description of these spectra has already been published. Both consist of overlapping progressions of bands degraded to the red. Raising the temperature of the absorbing vapour causes bands at the long wave-length ends of the spectra to be developed, the extent of the bands depending only on the maximum temperature used (for the same vapour-pressure). Lead sulphide bands in the region of greatest dispersion show apparently simple rotational structure. By analogy with PbO it would appear that the electronic transition is 1 ∑ ⟵ 1 ∑.

scholarly journals The spectrum of thallium fluoride

1937 ◽  
Vol 160 (901) ◽  
pp. 242-253 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Kinetic Energy ◽  
The Other ◽  
Molecular Spectra ◽  
Absorption Tube ◽  
Saturated Vapour ◽  
Long Wave ◽  
Original Investigation ◽  
Wave Edge

This study of the thallium fluoride spectrum was undertaken as part of a detailed investigation into the molecular spectra of the series of heavy diatomic fluorides HgF, TlF, PbF and BiF. Whereas the spectra of PbF (Rochester 1936) and BiF (Howell 1936), of which analyses have already been published, contain no very unusual features the TlF spectrum is particularly rich in them, so that it has seemed desirable to extend the original investigation in order to include the other halides of thallium. The absorption spectrum of the fluoride has already been examined by Boizova and Butkow (1936), their findings being summarized below: 1— A continuum at 2200 A appears when the absorption tube is at a temperature of 155° C. Its long-wave edge moves towards the red with increase of temperature, being at 2700 for the unsaturated vapour and at 3400 for the saturated vapour when the temperature is 280° C. They attributed this continuum to the dissociation of Tl 2 F 2 . Tl 2 F 2 → 2TlF + kinetic energy.

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