scholarly journals The spark-spectra of indium and gallium in the extreme ultra-violet region

1925 ◽  
Vol 107 (741) ◽  
pp. 138-156 ◽  
Keyword(s):  
Wave Length ◽  
Ultra Violet ◽  
Spectral Lines ◽  
The Other ◽  
Pressure Tubing ◽  
Quartz Spectrograph ◽  
One Stop ◽  
The One ◽  
Gas Tight ◽  
Concave Grating

The spark-spectrum of indium in the ultra-violet has been especially studied by Saunders, that of gallium by Saunders and Klein. By the use of a one-metre concave grating, mounted in a brass tube which could be exhausted, Saunders was able to extend the indium spark-spectrum as far below into the ultra-violet as λ = 1699 A. U. The line of shortest wave-length as yet noted in the gallium spark-spectrum—namely, λ = 2176 A. U.—was measured by Klein with a large quartz spectrograph whose mounting was of the Littrow type. With the object in view of making a complete and comprehensive examination of the spark-spectral lines of the above elements, that should extend right through the extreme ultra-violet and the quartz regions, the following investigations were undertaken. A.— Experiments in the Quartz Region . 1. Description of Apparatus .—For studying the spectra in the quartz region a spark chamber, diagrammatically shown in the figure, was employed. The spark chamber proper was a pyrex bulb about 7 inches in diameter. The terminals were of gallium and aluminium in the one experiment, and indium and aluminium in the other. Gallium has a very low melting point (30·2° C.). It was therefore placed in a tiny quartz cup, which, supported by a long aluminium rod, formed the lower terminal for the discharge. A piece of tungsten wire led from the aluminium support through the stem of the cup to the gallium. The upper electrode was of aluminium filed down to a point. Pieces of pressure tubing, 2 inches in length, lined with soft wax, fitted over the terminal supports and the tube elongations from the spark chamber. These formed gas-tight moveable joints, and served for the purpose of adjusting the spaek gap. The gap ranged from 2 to 3 mm. in width. The quartz window, through which the light passed into the spectrograph, was fastened to the spark chamber with sealing wax. One stop-cock led to the exhaust pumps, the other to the system of drying tubes. The spark was produced by a primary current of 110 volts ranging from 4 to 6 amperes. A Hilger Quartz-Prism Spectrograph, Type A, was used. All photographs were taken on Schumann plates.

scholarly journals Isotope shift in the resonance line of magnesium

1936 ◽  
Vol 154 (883) ◽  
pp. 679-683 ◽  
Keyword(s):  
Emission Line ◽  
Hyperfine Structure ◽  
Atomic Beam ◽  
Resonance Line ◽  
Isotope Shift ◽  
Wave Length ◽  
Spectral Lines ◽  
The Other ◽  
Absorption Lines ◽  
Doppler Width

By making use of an atomic beam instead of an ordinary gas or vapour, it is possible to observe structures of spectral lines very much smaller than the normal Doppler width. The structure of resonance lines can thus be observed as fine absorption lines on the background of the emission line possessing the full Doppler width. This method was used by the present authors for the detection and measurement of the hyperfine structure of the resonance lines of potassium and sodium. The following paper gives an account of the investigation of the structure of the singlet resonance line (2852 A) of magnesium by the same method. The line was found to possess two components at a separation of 0.033 cm -1 , the component of longer wave-length being very much stronger than the other.

The analysis of molybdates and tungstates

1966 ◽  
Vol 35 (275) ◽  
pp. 995-1002 ◽  
Author(s):  
A. J. Easton ◽  
A. A. Moss
Keyword(s):  
Optical Density ◽  
Wave Length ◽  
Ultra Violet ◽  
The Other ◽  
The Common ◽  
Significant Interference ◽  
And Tungsten

SummaryThe estimation of molybdenum and tungsten when present together has proved difficult, as is indicated by the large number of methods put forward for their determination. Many of the methods given are for one or other of these elements only, a note often being added that the presence of the other invalidates the method. The estimation of molybdate and tungstate in the mineral powellite has been briefly described by one of the authors (A. A. M.): molybdate and tungstate were precipitated as oxinates (Mo,W)O2(C9H6ON)2 and the molybdate (MoO4″) determined by measurement of the optical density at 230 mµ of a solution containing molybdate and tungstate. The amount of tungstate present was then estimated by difference. The property of the molybdate ion, MoO4″, to absorb strongly in the ultra-violet has been further investigated and it has been found that, if a wave-length of 240 mµ is chosen and the proper precautions taken, the MoO4″ ion can be estimated without significant interference by the WO4″ ion. Methods are given for the analysis of the common molybdate and tungstate minerals, together with results obtained during the course of this investigation.

Notes on Spectrophotometry

1927 ◽  
Vol 23 (8) ◽  
pp. 959-969 ◽  
Author(s):  
R. W. Ditchburn
Keyword(s):  
Continuous Spectrum ◽  
Wave Length ◽  
Ultra Violet ◽  
Comparison Method ◽  
Short Wave ◽  
The Other ◽  
Constant Intensity ◽  
Large Dispersion ◽  
Short Wave Length ◽  
Different Parts

The source of light used as a background is an important factor in determining the convenience and accuracy of ultra-violet absorption work, etc. If a source of light of constant intensity is available, a direct comparison method can be used and it is only necessary to calibrate the plates. If the source of light is not constant in intensity, it is necessary to divide the light into two beams and use one to check the variations of intensity while the other goes through the absorbing substance or (during calibration) the reducing sector or wedge. This latter method requires much more complicated apparatus and if the variations in the source are at all large it becomes inaccurate. In addition to being constant in intensity a good background for ultra-violet absorption spectra should possess the following qualities:(1) Most of the energy should be emitted in the form of a continuous spectrum.(2) It is desirable to be able to use one photograph of the whole region to be investigated. For this purpose it is necessary that the variations of intensity in different parts of the spectrum should be small enough for it to be possible to arrange the exposure so that all parts of the spectrum are within the correct exposure range, i.e. it must not be necessary to over-expose any part in order to get a strong enough intensity at another wave-length.The hydrogen continuous spectrum possesses both these qualities and is an excellent background for the region on the short wave-length side of 3200 A.U. It may be used for longer wavelengths, but the hydrogen secondary lines are apt to prove trouble-some unless a fairly large dispersion is used.

II. On the spectrum of the oxyhydrogen flame

1888 ◽  
Vol 43 (258-265) ◽  
pp. 347-348
Keyword(s):  
Visible Region ◽  
Ultra Violet ◽  
The Other ◽  
The One ◽  
Oxyhydrogen Flame

In a former communication the authors described simultaneously with Dr. Huggins the strongest portion of the spectrum of water, subsequently they described a second less strong but more refrangible section of the same spectrum. M. Deslandres has noticed a third still more refrangible section. The authors now find that the spectrum extends, with diminishing intensity, into the visible region on the one hand, and far into the ultra-violet on the other.

scholarly journals Selling Spectacular Urban Life: Urban Space and Lifestyle in the Promotion Media of Apartment in Yogyakarta

2021 ◽  
Vol 8 (1) ◽  
pp. 36-48
Author(s):  
Ratna Noviani ◽  
Elok Santi Jesica
Keyword(s):  
Urban Space ◽  
Urban Life ◽  
The Other ◽  
Extended Time ◽  
Time Compression ◽  
Living Space ◽  
One Stop ◽  
The One ◽  
Urban Arts ◽  
The City

This article discusses how urban life is represented through the Barsa City, Uttara the Icon, and The Palace apartment advertisements and promotional videos. Applying Guy Debord's idea of spectacle to examine how urban life is transformed into visualization and commodification, also George Ritzer’s idea of re-enchantment of the disenchanted world and the new means of consumption. This article is aimed to analyze the position of apartments in the urban space of Yogyakarta that is discursively constructed through apartment promotional media. The conclusion of this research shows that apartments are functionalized to create the spectacle of the city. Urban space and life are aestheticized and spectacularized, in which apartments are displayed as part of dramatic and extravagant urban arts. Presented as one-stop-serving buildings, the apartments also promote the fusion of living space, urban style experience, and consumption which lead to the difficulty in distinguishing spatial boundaries. The advertisements and promotional videos of the apartment in Yogyakarta also promote temporal paradox. On the one hand, it promotes time compression and speed, meanwhile, on the other hand it promotes prolonged and extended time to foster consumption in the urban space.

scholarly journals INFLUENCE OF LIGHT ON THE GROWTH AND MALIGNANCY OF A TRANSPLANTABLE NEOPLASM OF THE RABBIT

1927 ◽  
Vol 45 (3) ◽  
pp. 483-496 ◽  
Author(s):  
Louise Pearce ◽  
C. M. Van Allen
Keyword(s):  
Experimental Evidence ◽  
Malignant Disease ◽  
External Factor ◽  
Continuous Light ◽  
Ultra Violet ◽  
The Other ◽  
Constant Light ◽  
Constant Darkness ◽  
Light Conditions ◽  
The One

An experiment is reported in which an environment of constant and continuous light excluding the shorter ultra-violet rays, and one of constant darkness, have influenced the course and character of a malignant disease of rabbits induced by a transplantable neoplasm. Under the influence of constant light the level of malignancy was observed to be low; under the influence of constant darkness the level of malignancy was somewhat lower than in the control animals living under ordinary indoor light conditions, but the level was not as low as among the animals constantly illuminated. These observations furnish experimental evidence in support of the idea that there is a correlation between the external factor of light on the one hand and the manifestations of an experimental malignant disease on the other.

The Transformation of Thiols Compounded in Raw Rubber

1951 ◽  
Vol 24 (4) ◽  
pp. 914-915
Author(s):  
Jeanle Bras ◽  
Michel Montu
Keyword(s):  
Absorption Spectra ◽  
Analytical Method ◽  
Ultra Violet ◽  
Transformation Products ◽  
Ultraviolet Absorption ◽  
The Other ◽  
Inert Gas ◽  
Rubber Industry ◽  
Acetone Extraction ◽  
The One

Abstract During the last few years the rubber industry has made use of certain thiols, under the technical name of peptizing agents, which have the property of accelerating the plasticization of raw rubber during mastication. It is now known that this process of plasticization involves oxidation of the rubber, and that it does not take place in an atmosphere of an inert gas. Accordingly the present authors were induced, on the one hand, to follow the transformation of thiols during their participation in the mastication of rubber and, on the other hand, to observe their influence on the tendency of rubber to oxidize. In the first of these objectives, the analytical method utilized was ultra- violet absorption spectrography. To avoid pertubations in the spectra caused by the resins present in rubber, crepe rubber purified by acetone extraction was used in the experiments. The rubber was masticated at 100° C, and the thiol was added soon after the beginning of this mastication in the proportion of 5 per cent of the rubber. Samples were withdrawn at successive intervals of time, and the transformation products of the thiol, which were isolated by acetone extraction, were identified by their ultraviolet absorption spectra. In these experiments, chloroform solutions containing 0.5 gram per liter were employed.

scholarly journals Is Information a Sufficient Basis for Cognition? Part 2: Physical Foundations

2011 ◽  
Vol 9 (2) ◽  
pp. 367-376
Author(s):  
José María Díaz Nafría ◽  
Mario Pérez-Montoro
Keyword(s):  
A Priori ◽  
Wave Length ◽  
The Other ◽  
A Priori Knowledge ◽  
The One ◽  
Wave Phenomena ◽  
In Virtue Of ◽  
Physical Boundary ◽  
Homogeneous Environment

In this second part of our inquiry into the relation between information and cognition, we delve into the physical limits of the manifestation of an arbitrary object first with independence of any observer, then considering the nature of perception. The analysis of the manifestations of an object in a homogeneous environment by means of wave phenomena shows that the information carried by such manifestations offers a constitutive fuzziness and ambiguity of the observed object. On the one hand, the details that can be specified concerning the object are strictly limited by the wave length; on the other hand, the volumetric details of the object (i.e. its bowls) are outlawed to the observer, not in virtue of the object opacity, but to the very dimension or complexity of the wave phenomenon in the space surrounding the object. The analysis of perception, considering this physical boundary and the specificity of the animal sensitivity, shows the combined role of other concurrent or previous percept and some a priori knowledge in the perception and awareness of reality.

scholarly journals On the fluorescence of iodine vapour excited by ultra-violet light

1914 ◽  
Vol 91 (623) ◽  
pp. 23-29 ◽  
Keyword(s):  
Fluorescence Spectrum ◽  
Wave Length ◽  
Ultra Violet ◽  
Quartz Tube ◽  
Glass Tubing ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Fused Quartz ◽  
Quartz Spectrograph ◽  
Narrow Bands

In a recent communication by the writer a new fluorescence spectrum of iodine vapour was described which could be stimulated by the light from the mercury arc. This fluorescence spectrum consisted of a set of narrow bands extending from λ 4600 down to λ 2100. While of this spectrum was clearly defined, the most intensely marked portion of it was made up of a set of seven equally spaced bands between λ 3315 and λ 3175. in obtaining the spectrum a highly exhausted tube of fused quartz containing a few iodine crystals was inserted axially in an ordinary glass Cooper-Hewitt mercury are lamp, with a lateral anode and provided with a short extension at the positive end, to which the quartz tube was sealed with mastic wax. The quartz iodine vapour tube was provided with a window of clear fused quartz, towards which the collimator of quartz spectrograph was directed in taking the photographs. When the Copper-Hewitt tube was in action the are played directly upon the inserted quartz tube and so subjected the vapour contained in it to intense illumination. In the paper describing this fluorescence spectrum of iodine vapour it was pointed out that it was impossible to obtain the spectrum when the inserted tube containing the iodine vapour was made of combustion glass tubing. It was also pointed out that this glass tubing was found to be transparent to the light from the mercury are down to λ 2893∙7, and on account of this fact the conclusion was drawn that the light which stimulated the iodine vapour to the flurescence referred to must have had a shorter wave-length than λ 2893∙7.

scholarly journals QUANTITATIVE STUDIES ON THE PHOTOLETHAL EFFECTS OF QUARTZ ULTRA-VIOLET RADIATION UPON PARAMECIUM

1935 ◽  
Vol 18 (4) ◽  
pp. 557-571 ◽  
Author(s):  
A. C. Giese ◽  
P. A. Leighton
Keyword(s):  
Wave Length ◽  
Ultra Violet ◽  
The Other ◽  
Ultra Violet Radiation ◽  
Quantitative Studies ◽  
Controlled Conditions ◽  
Order Of Magnitude ◽  
Intense Light ◽  
Violet Radiation

Paramecia grown under controlled conditions were irradiated at known intensities of light of wave-lengths 2537, 2654, 2804, 3025, and 3130 A. The approximate absorption of the light by the Parmecia was found to be greatest and of the same order of magnitude at the three shortest wave-lengths, considerably less at 3025, and least at 3130 A. Paramecia did not die when irradiated with high dosages of intense light of wave-length 3130 A. At the other wave-lengths 50 per cent vesiculation occurred when between 1012 and 1013 quanta had been absorbed by a Paramecium. This would indicate that a very large number of molecules in a Paramecium are affected before vesiculation occurs.

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