Spectra in the O-H stretching region of mono- and oligo-saccharides at low temperatures

1968 ◽  
Vol 21 (5) ◽  
pp. 1257 ◽  
Author(s):  
AJ Michell
Keyword(s):  
Fine Structure ◽  
Low Temperature ◽  
Low Temperatures ◽  
Room Temperature ◽  
Coupled Vibrations ◽  
Temperature Spectra

Spectra in the O-H stretching region of some mono- and oligosaccharides have been obtained at low temperatures. Bands in the low-temperature spectra were found to be sharper and better resolved, and some bands were revealed which were not apparent at room temperature. Spectra have also been obtained in both the O-H and O-D stretching regions of partly deuterated samples of two glycosides and an oligosaccharide. From these it has been shown that the fine structure in the O-H stretching region of the spectra of these compounds arises from coupled vibrations rather than from separate vibrations of individual groups. This coupling is probably the underlying reason for the large widths of bands in this region of the spectrum of carbohydrates.

scholarly journals The behaviour of visual purple at low temperature

1941 ◽  
Vol 179 (977) ◽  
pp. 151-159 ◽  
Keyword(s):  
Aqueous Solution ◽  
Low Temperature ◽  
Low Temperatures ◽  
Room Temperature ◽  
Absorption Curve ◽  
Quantum Yields

Visual purple is soluble and stable in a mixture of glycerol and water (3:1). At room temperature the spectrum of such a solution is identical with that of the aqueous solution. At — 73° C the peak of the absorption curve is higher and narrower than at room temperature, and it is shifted towards longer waves. The product of photodecomposition at — 73° C has a spectrum in ­ dependent of pH and is at low temperatures thermostable and photostable, but at room temperature it decomposes therm ally to indicator yellow. The primary product appears to be identical with transient orange. The quantum yields of the photoreaction at low and at room temperature are of the same order.

Fine structure of the bands in the low-temperature spectra of sodium uranyl acetate

1982 ◽  
Vol 37 (5) ◽  
pp. 1277-1281 ◽  
Author(s):  
V. N. Boikov ◽  
A. N. Krasovskii ◽  
D. S. Umreiko
Keyword(s):  
Fine Structure ◽  
Low Temperature ◽  
Uranyl Acetate ◽  
Temperature Spectra

Compressive Plasticity of Zr-Based Bulk Metallic Glass at Low Temperature

2012 ◽  
Vol 443-444 ◽  
pp. 583-586
Author(s):  
Ya Juan Sun ◽  
Ri Ga Wu ◽  
Hong Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Low Temperatures ◽  
Room Temperature ◽  
Shear Bands ◽  
Strain Curve ◽  
Testing Temperature ◽  
Stress Strain Curve

The mechanical properties of a new Zr-based bulk metallic glass at low temperatures were investigated. The results indicate that the fracture strength increases significantly (4.9%) and the global plasticity increases somewhat when testing temperature is lowered to 123K. The stress-strain curve of the sample deformed exhibits more serrations and smaller stress drop due to formation of more shear bands at low temperature than at room temperature.

scholarly journals THE INFLUENCE OF TEMPERATURE ON THE ACTION OF STRYCHNIN IN FROGS

1913 ◽  
Vol 18 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Thomas Stotesbury Githens
Keyword(s):  
Low Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Room Temperature ◽  
Drug Action ◽  
The State ◽  
Great Caution ◽  
Influence Of Temperature ◽  
Influence Of Temperature On

In order to establish the influence of temperature upon the effect of varying doses of strychnin injected into frogs, the animals must be kept under observation for several days and at various definite degrees of temperature. Statements that the animal was kept "cold," "at room temperature," or "warm" are insufficient. With a certain dose tetanus may result constantly at 30° C. yet never appear at 21° C., and either of these temperatures might be described as warm, when compared to a room temperature of 15° C. Furthermore an animal may apparently fail to respond in the cold to an injection of certain doses of strychnin and yet be found in tetanic convulsions the next day. That an animal may have late, long lasting, or strong tetanus while kept at such a low temperature as 5° C. after an injection of a dose of strychnin smaller than 0.01 of a milligram per frog emphasizes the fact that great caution must be exercised in formulating laws as to the influence of temperature on drug action. The main results of this investigation may be summarized as follows: Doses of strychnin amounting to 0.0006 of a milligram per gram of frog will cause tetanus at all temperatures between 5° C. and 30° C., although at low temperatures the tetanus may appear late. A dose of 0.0003 of a milligram per gram of frog will frequently produce tetanus at 5° C. as well as at 30° or 27° C., but may nevertheless fail to produce any reaction at such an intermediary temperature as 21° C. Smaller doses, 0.0002 of a milligram per gram, will cause tetanus in the cold but not at high temperatures. It may be stated in general that in frogs kept at low temperatures the tetanic state sets in later, continues longer, and each tetanic attack is of longer duration, while in the interval between the attacks the state of tonus is higher and the animals are more irritable than when they are kept at higher temperatures.

INVESTIGATIONS OF PERMEABILITY, DIAPAUSE, AND HATCHING IN THE EGGS OF THE MOSQUITO AEDES HEXODONTUS DYAR

1958 ◽  
Vol 36 (4) ◽  
pp. 541-554 ◽  
Author(s):  
W. E. Beckel
Keyword(s):  
Low Temperature ◽  
Sodium Hypochlorite ◽  
Water Loss ◽  
Low Temperatures ◽  
Room Temperature ◽  
Early Embryo ◽  
Adult Mosquito ◽  
Egg Cell ◽  
Distilled Water ◽  
Exposure To Cold

Methods for collection in the laboratory of many thousands of eggs from field-collected, blood-fed females are described. Also a way of separating fertile from infertile eggs is outlined. When the eggs are laid they are white but begin to darken within one-half hour. The darkening did not occur when the egg cell or early embryo was killed.Two changes in permeability in the prediapause stage of the eggs of Aedcs hexodontus were observed. The first took place as the chorion changed from white to black. The egg lost and gained water easily when first laid but resisted water loss and uptake as the chorion darkened. However, a complete waterproofing did not result. With the formation of the transparent cuticle a further change in permeability occurred. The egg lost hardly any water even when exposed to extreme desiccation and what little water was lost was regained very slowly. However, the cuticle, with the chorion removed in sodium hypochlorite, was quite permeable. The impermeability of the chorion and cuticle combination must result from the bonding between the two and this bonding must be disrupted by the dechorionation.To study the obligate diapause that occurs in the late embryogeny of the mosquito egg the effect of making water available to the embryo, of light, and of low temperature was studied. Diapause was not broken when water was available to the embryo, nor did alternate periods of light and dark at room temperature or at lower temperatures disrupt the diapause. To test the influence of cold the temperature of 1° and −3 °C. were used to simulate the temperatures in the field. The low temperatures were found to terminate the diapause but the numbers of eggs hatching did not steadily increase with an increase in the time of exposure to cold. No clue has as yet been discovered to explain these results. A hatching infusion of decaying adult mosquito bodies in distilled water was found to give more hatching than did distilled water alone. The mechanism of the hatching stimulus is not known.

Primary Defects in n-Type Irradiated Germanium: A First-Principles Investigation

2007 ◽  
Vol 131-133 ◽  
pp. 253-258 ◽  
Author(s):  
A. Carvalho ◽  
R. Jones ◽  
C. Janke ◽  
Sven Öberg ◽  
Patrick R. Briddon
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Electron Irradiation ◽  
First Principles ◽  
Low Temperatures ◽  
Damage Evolution ◽  
Room Temperature ◽  
Temperature Electron ◽  
Conductivity Loss

The properties of point defects introduced by low temperature electron irradiation of germanium are investigated by first-principles modeling. Close Frenkel pairs, including the metastable fourfold coordinated defect, are modelled and their stability is discussed. It is found that damage evolution upon annealing below room temperature can be consistently explained with the formation of correlated interstitial-vacancy pairs if the charge-dependent properties of the vacancy and self-interstitial are taken into account. We propose that Frenkel pairs can trap up to two electrons and are responsible for conductivity loss in n-type Ge at low temperatures.

THE EFFECT OF ELECTRICAL STIMULATION AT LOW TEMPERATURES ON THE LARVAE OF PHOCANEMA DECIPIENS

1961 ◽  
Vol 39 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Clare Bradley
Keyword(s):  
Electrical Stimulation ◽  
Low Temperature ◽  
Low Temperatures ◽  
Room Temperature ◽  
Morphological Changes ◽  
Neuromuscular System ◽  
Anodal Stimulation ◽  
Rhythmical Activity ◽  
Cathodal Stimulation

Observations were made on the effect of low temperatures (down to 0° C) on the response of Phocanema to external polarizing stimuli. The response to anodal stimulation (contraction) was not affected by a fall in temperature. The response to a cathodal stimulus varied with the temperature, and whereas at room temperature the response was a relaxation, at low temperatures it was either a contraction or it was blocked altogether. Storage of the worm at low temperature for several hours had a similar effect. In some cases spontaneous rhythmical activity ceased as the temperature fell; this effect was shown to be independent of the effect of low temperature on the response to cathodal stimulation. No associated morphological changes in the neuromuscular system were observed.

scholarly journals Fine Structure in the Low Temperature Spectra of Catalase Complexes.

1963 ◽  
Vol 17 supl. ◽  
pp. 257-262 ◽  
Author(s):  
Britton Chance ◽  
Gregory R. Schonbaum
Keyword(s):  
Fine Structure ◽  
Low Temperature ◽  
Temperature Spectra

Heat Conductivity of Rubber at Low Temperatures

1940 ◽  
Vol 13 (4) ◽  
pp. 830-830
Author(s):  
Adolf Schallamach
Keyword(s):  
Low Temperature ◽  
Physical Properties ◽  
Temperature Region ◽  
Heat Conductivity ◽  
Low Temperatures ◽  
Room Temperature ◽  
Tire Rubber ◽  
Order Of Magnitude ◽  
Temperature Work

Abstract While examining the possibilities of applying rubber in low temperature work, we were hampered by the lack of available data on its physical properties at low temperatures. We were aware of the difficulties to be expected in making accurate measurements in that temperature region, and this applied especially to the heat conductivity, in which we were particularly interested. To obtain at least an estimate of the order of magnitude, we carried out some measurements of the heat conductivity of commercial rubber (North British tire rubber) at room temperature and at the temperature of liquid air.

Low-Temperature Growth of Thin Films of A12O3 with Trimethylaluminum and Hydrogen Peroxide

1991 ◽  
Vol 222 ◽  
Author(s):  
J. F. Fan ◽  
K. Sugioka ◽  
K. Toyoda
Keyword(s):  
Thin Films ◽  
Hydrogen Peroxide ◽  
Low Temperature ◽  
Chemical Reaction ◽  
Low Temperatures ◽  
Arbitrary Shape ◽  
Room Temperature ◽  
Surface Chemical ◽  
Surface Chemical Reaction ◽  
Temperature Growth

ABSTRACTThin films of A12O3 were prepared by sequential surface chemical reaction of trimethylaluminum and hydrogen peroxide at low temperatures. It has been found that hydrogen peroxide reacts very easily with trimethylaluminum, resulting in growth of A12O3 at the temperature as low as the room temperature. Another favorable feature of the technique is that the growth of excellent A12O3 occurs identically wherever the reactants reach, making it possible to completely coat the surface of the sample with arbitrary shape.

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