scholarly journals The Further Effects of Irradiation on the Oestrous Cycle of the Ferret

1936 ◽  
Vol 13 (4) ◽  
pp. 383-386
Author(s):  
F. H. A. MARSHALL ◽  
F. P. BOWDEN
Keyword(s):  
Ultra Violet ◽  
Oestrous Cycle ◽  
The Other ◽  
Violet Light ◽  
Long Wave ◽  
Infra Red ◽  
Long Time ◽  
To Come ◽  
Incandescent Lamps ◽  
Effects Of Irradiation On

The investigation of the effect of radiation on the oestrous cycle of the female ferret has been continued. (1) The earlier experiments with the ultra-violet light have been repeated and confirmed. Irradiation with light of λ 3650Å. caused the ferrets to come on heat early and to remain on heat for an abnormally long time after irradiation had ceased. (2) Heat rays of long wave-lengths caused no acceleration. This is in accordance with earlier experiments which showed that heat rays and infra-red (λ 7500Å.) had little effect. (3) Two pairs of ferrets were subjected to the same total quantity of radiation from incandescent lamps, but in one case it was concentrated into 2 hours, and in the other spread over 16 hours. There was little difference in the behaviour of the two pairs and both showed an acceleration of oestrus.

scholarly journals Infra-red spectroscopy and its application to microbiology

1959 ◽  
Vol 57 (3) ◽  
pp. 326-345 ◽  
Author(s):  
K. P. Norris
Keyword(s):  
Ultra Violet ◽  
The Other ◽  
Violet Light ◽  
Initial Cost ◽  
Infra Red ◽  
Two Factors ◽  
High Initial Cost ◽  
Micro Organisms ◽  
Red Radiation ◽  
Absorption Measurements

Colorimeters and non-recording spectrophotometers for visible and ultra-violet light have been used for many years and are to be found in most microbiological laboratories. With the need for greater speed of operation, recording instruments are now coming into more general use. During the last two decades recording infra-red spectrophotometers have been developed and these have enabled the absorption measurements on micro-organisms to be extended into the infra-red region of the spectrum. Two factors have tended to retard the use of infra-red spectrophotometry. One is the high initial cost of the equipment and the other is the large absorption of infra-red radiation by water. Despite these difficulties, a considerable amount of work has now been done and it seems profitable to review the varied applications to which infra-red spectroscopy has already been put and to indicate the results which have been obtained by its use.

scholarly journals Diet and Tuberculosis

1927 ◽  
Vol 26 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Harry Schütze ◽  
S. S. Zilva
Keyword(s):  
Vitamin C ◽  
Guinea Pigs ◽  
Ultra Violet ◽  
The Other ◽  
Cod Liver Oil ◽  
Large Excess ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Fat Soluble Vitamins ◽  
Intraperitoneal Inoculation

Guinea-pigs living on a diet restricted in quantity but not deficient in vitamin C survived inoculation with T.B. but half as long as others which had received a similar diet in abundance.Sodium chaulmoograte did not inhibit the development of the omental tumour that appears in rats after intraperitoneal inoculation with tubercle bacilli.On the other hand, there was some evidence for assuming that a large excess of fat-soluble vitamins in the diet, as supplied by cod-liver oil, inhibits the formation in rats of these tuberculous tumours, but such evidence was by no means conclusive.Similar inhibition of omental infection was obtained on exposing rats to ultra-violet light.Ultra-violet irradiation or the inclusion of large amounts of cod-liver oil in the diet of the rats produced a slight but constant leucocytosis.No evidence was obtained that lack of fat soluble vitamins in their diet renders tubercle infected rats susceptible to tuberculin shock.

Aging of Stretched Rubber

1928 ◽  
Vol 1 (1) ◽  
pp. 106-112
Author(s):  
Arthur Kelly ◽  
Bert S. Taylor ◽  
Webster N. Jones
Keyword(s):  
Direct Relationship ◽  
Strain Curve ◽  
Ultra Violet ◽  
The Other ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Test Strips ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Early Stages

Abstract Sunlight aging under tension of many compounds including the following has been investigated: tire tread shoe upper, tube stocks, golf ball thread, jar rubber, solid tire, bathing cap stock, channel rubber. With some of these stocks the sunlight aging as been compared with unstretched samples by Geer oven, Bierer bomb, and ultra-violet light methods. The stretching of the test strips accelerates deterioration in sunlight, ultra-violet light, and Geer oven. Stretched samples have not yet been tested in the Bierer bomb. The rate of deterioration was not proportional to the degree of stretch in any of the stocks in the early stages of exposure. In sunlight there is a critical elongation for each stock at which the deterioration progresses more rapidly than at any other in the early stages of aging. No direct relationship was found between the results of sunlight aging and the other methods employed. Stretched strips aged in ultra-violet light were found to give softer stress-strain curves than the unaged samples, whereas sunlight aging under the same conditions stiffens the stress-strain curve.

The Bakerian Lecture, The spectra and structures of free methyl and free methylene

1961 ◽  
Vol 262 (1310) ◽  
pp. 291-317 ◽  
Keyword(s):  
Free Radicals ◽  
Electronic Spectra ◽  
Molecular Spectroscopy ◽  
Diatomic Molecules ◽  
Ultra Violet ◽  
Electric Discharges ◽  
Angular Momenta ◽  
Infra Red ◽  
Long Time ◽  
Resonance Transitions

The spectra of many diatomic free radicals like those of CH, OH, NH, C 2 , CN have been known and identified as such almost since the beginning of molecular spectroscopy. They occur readily in emission in a variety of flames (including the ordinary Bunsen burner) and in electric discharges. It was through the study of these spectra that our knowledge of the structure of diatomic molecules was developed and in particular that the different coupling conditions between the electron spin and the other angular momenta were recognized. Most of the resonance transitions of the diatomic free radicals lie in the visible or near ultra-violet region where a detailed high-resolution study is easily possible. It is for this reason also that these spectra play a most prominent part in the spectra of astrophysical sources: comets, low-temperature stars and the interstellar medium. The spectra of free polyatomic radicals have become recognized and analyzed only in the last ten or fifteen years. The reason for this delay is the much greater complexity of the spectra of polyatomic as compared to the spectra of diatomic molecules combined with the greater difficulty of exciting these spectra in emission. Ordinary polyatomic molecules can easily be studied in infra-red absorption or by means of the Raman effect. The infra-red and Raman spectra are simpler than the electronic spectra and their interpretation has been established for a long time; but up to now no infra-red (or Raman) spectrum of a free polyatomic radical has been obtained. One is entirely dependent on electronic spectra for the study of the structure of polyatomic free radicals, and these electronic spectra exhibit many complexities.

scholarly journals The occurrence of ozone in the upper atmosphere

1914 ◽  
Vol 90 (617) ◽  
pp. 204-219 ◽  
Keyword(s):  
Ultra Violet ◽  
Upper Atmosphere ◽  
Blue Colour ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Long Time ◽  
Physical And Chemical ◽  
Atmospheric Phenomena

The question of the occurrence of ozone in the atmosphere has been for a long time a subject of much speculation, on account of the important bearing it has, both from physical and chemical considerations, in dealing with many atmospheric phenomena. Many workers have shown the marked absorption effects that small quantities of ozone have on ultra-violet light.* The view has also been put forward that this gas plays an important part in contributing to the blue colour of the sky.

scholarly journals Application of the Wilson chamber to the study of spark discharge

1935 ◽  
Vol 148 (864) ◽  
pp. 446-453 ◽  
Keyword(s):  
Ultra Violet ◽  
Spark Discharge ◽  
Cloud Chamber ◽  
The Other ◽  
Present Stage ◽  
Expansion Chamber ◽  
Ultra Violet Light ◽  
Violet Light ◽  
Negative Point ◽  
Kerr Cell

The usual methods of investigating the problems related to the phenomenon of spark discharge may be classified into two kinds. The first is to measure the potential and current or their variations with respect to time, which may be called "electrical." By this means we know only the signals transmitted from the spark. The second method is optical, to which belong the photographic and spectrographic investigations as well as the method using a Kerr cell. These methods give us information on the spark itself, but they are confined to the problems accompanied with the emission of light. For observing a process of discharge that does not accompany any luminous phenomenon, the use of Professor Wilson's cloud chamber seems to be the only method suitable for the for the purpose at our present stage of knowledge. As a matter a fact, already in 1899 Wilson, using an expansion chamber of the earlier type, had investigated the formation of ion clouds by the positive and negative point discharges. Since then no communication seems to have been published on the formation of ion clouds by an electrical break-down process until recently, when the present authors and Snoddy and Bradley published independently the reports of their experiments of this subject. Several years ago one of the present authors, under the direction of Professor T. Terada, engaged, in a study concerning the form and structure of long electric sparks. He then succeeded, using a quartz-fluorite ions, in taking a photograph of the brush discharges immediately preceding the main spark. This preceding discharge is rich in ultra-violet light, and more complicated and extended in its form than the succeeding main spark, appearing as appendages to the luminous spark track. This result led him to look for the other form of discharge which cannot be photographed even with the quartz-fluorite lens. Then, on the suggestion of Professor T. Terada, he tried to take a Wilson photograph of ions produced by a spark, but did not succeed in obtaining a satisfactory one. Later on, in the course of conversation with Professor Wilson at Cambridge he was given a great deal of advice on this problem and decided to take up this subject again.

XXXIX.—The Absorption of Light by Inorganic Salts. No. IV.: Aqueous Solutions of Cobalt and Nickel Salts in the Ultraviolet

1912 ◽  
Vol 31 ◽  
pp. 547-558 ◽  
Author(s):  
R. A. Houstoun ◽  
John S. Anderson
Keyword(s):  
Ultra Violet ◽  
Practical Method ◽  
Inorganic Salts ◽  
Metal Electrodes ◽  
Violet Light ◽  
Limited Success ◽  
Absorption Of Light ◽  
Infra Red ◽  
Enormous Amount ◽  
Cobalt And Nickel

In Kayser's Spectroscopie, vol. iii. pp. 45–49, an account is given of all the different methods that have hitherto been employed for photometry in the ultra-violet part of the spectrum. Photography, phosphorescent plates, selenium cells, and the ionising effect of ultra-violet light have all been used, but with limited success, and Professor Kayser considers that the only really practical method is that which has been recently introduced by Pfluger. Pfliiger has discovered that there is relatively an enormous amount of energy in the ultra-violet spectrum of the electric spark produced by the discharge of a condenser between metal electrodes. He therefore uses the electric spark as a source, and takes the deflections with a thermopile and galvanometer, just as in the infra-red. He finds the deflections to be wonderfully steady, considering the inconstant nature of the spark.

Conclusion

2017 ◽  
Author(s):  
Peter Banki
Keyword(s):  
Mutual Recognition ◽  
The Other ◽  
Foreseeable Future ◽  
Natural Time ◽  
Long Time ◽  
To Come

It is no doubt significant that on the sole occasion (to my knowledge) when Derrida provides a positive characterization of what forgiveness is or might be, it is by means of the interpretation of a joke: “Two Jews, long-time enemies, meet at the synagogue, on the Day of Atonement [le jour du Grand Pardon]. One says to the other [as a gesture, therefore, of forgiveness—J. D.]: ‘I wish for you what you wish for me.’ The other immediately retorts: ‘Already you’re starting again?’” In the mutual recognition between the two enemies that forgiveness is impossible, Derrida suggests a certain compassion, even perhaps forgiveness, passes between them. Under the sign of a perhaps, the imagined laughter between the two Jews is “the regime of a possible whose possibilization must prevail over the impossible.” On this basis I interpret Derrida’s forgiveness as a messianic promise, a forgiveness to come, whose temporality must be distinguished from Jean Améry’s “natural time-sense,” i.e., the foreseeable future of reconciliation and normalization founded on amnesia.

New Experiments on Colour Vision in Bees

1939 ◽  
Vol 16 (1) ◽  
pp. 1-8
Author(s):  
MATHILDE HERTZ
Keyword(s):  
Visible Light ◽  
Visible Spectrum ◽  
Ultra Violet ◽  
White Paper ◽  
The Other ◽  
Green Paper ◽  
Violet Light ◽  
Orange Yellow ◽  
Two Peaks ◽  
Do So

Under the condition of full, normal daylight illumination a surface which reflects a fair proportion of ultra-violet, as well as the visible spectrum, is neutral or white in the vision of the bee. If the percentage of reflexion of 3600 A. is less than one-third, or about one-quarter, of the percentage of reflexion in the visible light, a degree of coloration is obtained which is sufficient to be noticed by the bees in training experiments. When both are placed under ultra-violet absorbing filters, white paper in the vision of the bee most closely resembles a blue-green paper that possesses the highest amount of reflexion at 4900 A. Bees which have been trained to visit a blue-green surface covered by a filter glass do not do so any longer, if, by removing the filter, ultra-violet light is added to the reflexion. The paper that possesses now two peaks of maximum reflexion, one at 4900 and the other at 3600 A., appears a light grey to the bee. On the other hand, when bees have been trained to visit an ultra-violet surface--white paper under a filter that absorbs the visible light completely--do not do so any longer if by lifting the filter the whole range of visible light is added to the reflexion of ultra-violet. The white paper at once becomes unattractive to the bee. There remains no doubt, that among the four qualities of colour discriminated by the bee (see Fig. 1) the first and the third on one side and the second and fourth on the other are complementary colours for this insect and presumably for many others. In the European flowers visited by bees three principal colours are now finally known: (1) that colour which is perceived if the main bulk of light reflected by the petals lies between 6500 and 4900 A. (orange-yellow for bee and man), (2) that which is perceived if the reflexion extends from 4900 to 4000 or 3500 A. (blue-violet for bee and man), and (3) that which is perceived if the reflexion extends from 6500 A., or nearer to the red end of the visible spectrum, to 4000 A. (blue-green for the bee, but white, pink, light purple, bluish or yellowish for man). Ultra-violet seems never to occur in European flowers in such a way as to make petals which are brilliantly white for man to appear equally white for the bee.

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