THE VARIATION OF THE VISCOSITY OF GASES WITH TEMPERATURE OVER A LARGE TEMPERATURE RANGE

1935 ◽  
Vol 13b (3) ◽  
pp. 140-148 ◽  
Author(s):  
A. B. Van Cleave ◽  
O. Maass
Keyword(s):  
Carbon Dioxide ◽  
High Temperatures ◽  
Methyl Ether ◽  
Sulphur Dioxide ◽  
Low Temperatures ◽  
Room Temperature ◽  
Empirical Equation ◽  
Large Temperature ◽  
Temperature Range ◽  
Inversion Temperature

The coefficients of viscosity of ammonia, propylene, ethylene and methyl ether, over the temperature range 23 to −80 °C., have been measured. A comparison is made between the present data and those of other authors for temperatures above 0 °C. It is estimated that the authors' results are correct to 0.2% and have a relative accuracy of 0.1%. It is claimed that they are the most accurate data for the viscosity of gases at low temperatures to date.The validity of a number of viscosity–temperature relations has been tested with the present data and those previously published (18, 20). In general, it is found that the equations of Sutherland and Jones hold at high temperatures but fail at low temperatures for substances such as carbon dioxide, sulphur dioxide, ammonia, methyl ether and propylene, which have viscosity–temperature curves that are convex to the temperature axis below room temperature. An empirical equation is suggested which adequately represents the variation of viscosity with temperature for these five gases over the temperature range 23 to −80 °C. However, this relation fails at high temperatures for all gases, and even at low temperatures for substances such as hydrogen, air and ethylene.It is pointed out that the viscosity–temperature curves for carbon dioxide, sulphur dioxide, ammonia, methyl ether and propylene each show a definite inversion or inflexion point. Below this inversion temperature the viscosity curves are convex to the temperature axis; above it they are concave to the temperature axis. In general, it seems that this inversion temperature bears a direct relation to the polarity of the molecule and to the critical temperature.

scholarly journals The diffusion of hydrogen through copper

1936 ◽  
Vol 153 (880) ◽  
pp. 504-512 ◽  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Large Temperature ◽  
Temperature Range ◽  
Copper Solution ◽  
Diffusion Of Hydrogen

At temperatures higher than about 400°C, several observers have determined the rates of diffusion of hydrogen through copper, and only recently has a paper by Smithells and Ransley appeared, giving measurements on diffusion as low as 225°C. Sieverts, Deming and Hendricks, and Lombard have shown that the copper tubes and plates used in the experiments at high temperatures tend to crystallize and become fissured, so that the measurements are of little value. The adsorption of hydrogen by copper has been thoroughly studied over a large temperature range. Ward has shown that, at low temperatures, the immediate initial adsorption is followed by a slow solution of the hydrogen in the copper. Solution increases very rapidly with temperature, and above 160°C is so large and so rapid that the initial adsorption cannot be accurately determined.

Emergence and origin of broader light emission from two-dimensional layered (C12H25NH3)2MnCl4 at low-temperatures

2021 ◽  
Author(s):  
Madhu Bochalya ◽  
Anand Nivedan ◽  
Sandeep Kumar ◽  
Arvind Singh ◽  
Sunil Kumar
Keyword(s):  
Emission Spectrum ◽  
Hybrid System ◽  
Low Temperatures ◽  
Room Temperature ◽  
Light Emission ◽  
Large Temperature ◽  
Two Dimensional ◽  
Temperature Range ◽  
Organic Hybrid

We report broadband light emission (~350-800 nm) properties of two-dimensional layered (C12H25NH3)2MnCl4 inorganic-organic hybrid system in a large temperature range of ~5-400 K. At room temperature, the emission spectrum weighs...

Dynamic Viscosity of Compressed Water to 10 Kilobar and Steam to 1500°C

1969 ◽  
Vol 11 (2) ◽  
pp. 189-205 ◽  
Author(s):  
E. A. Bruges ◽  
M. R. Gibson
Keyword(s):  
Gaseous Phase ◽  
Dynamic Viscosity ◽  
Low Temperatures ◽  
Pressure Range ◽  
Low Pressure ◽  
Temperature Range ◽  
Inversion Temperature ◽  
Pressure Steam ◽  
Correlating Equations ◽  
First Time

Equations specifying the dynamic viscosity of compressed water and steam are presented. In the temperature range 0-100cC the location of the inversion locus (mu) is defined for the first time with some precision. The low pressure steam results are re-correlated and a higher inversion temperature is indicated than that previously accepted. From 100 to 600°C values of viscosity are derived up to 3·5 kilobar and between 600 and 1500°C up to 1 kilobar. All the original observations in the gaseous phase have been corrected to a consistent set of densities and deviation plots for all the new correlations are given. Although the equations give values within the tolerances of the International Skeleton Table it is clear that the range and tolerances of the latter could with some advantage be revised to give twice the existing temperature range and over 10 times the existing pressure range at low temperatures. A list of the observations used and their deviations from the correlating equations is available as a separate publication.

Notizen: Various Donors in n-ZnSb and the Influence of Sample Treatment

1975 ◽  
Vol 30 (3) ◽  
pp. 381-382 ◽  
Author(s):  
A. Abou- Zeid ◽  
G. Schneider
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Surface Effects ◽  
Sample Treatment ◽  
Temperature Range ◽  
Donor Doping ◽  
P Type

Various donor doping of ZnSb is investigated. Te-doping yields the most stable n-type crystals at room temperature; the samples show p-type behaviour at low temperatures. The influence of surface effects is demonstrated. It was possible to prepare n-type ZnSb for the whole temperature range.

THE REACTION OF HYDROGEN AND DEUTERIUM ATOMS WITH PROPANE

1939 ◽  
Vol 17b (12) ◽  
pp. 371-384 ◽  
Author(s):  
E. W. R. Steacie ◽  
N. A. D. Parlee
Keyword(s):  
Activation Energy ◽  
High Temperatures ◽  
Low Temperatures ◽  
Hydrogen Atoms ◽  
Temperature Range ◽  
Secondary Reactions

The reaction of hydrogen atoms with propane has been investigated over the temperature range 30° to 250 °C. by the Wood-Bonhoeffer method. The products are solely methane at low temperatures, and methane, ethane, and ethylene at higher temperatures.It is concluded that the results can be explained only by the assumption that the reaction[Formula: see text]is of importance. The bearing of this on the Rice-Herzfeld mechanisms is discussed. The activation energy of the reaction is 10 ± 2 Kcal.The main steps in the postulated mechanism are:Primary Reaction[Formula: see text]Secondary Reactions at Low Temperatures[Formula: see text]Additional Secondary Reactions at High Temperatures[Formula: see text]The reaction of deuterium atoms with propane was also investigated. It was found that the methane and ethane produced were highly deuterized, while the propane was not appreciably exchanged.

scholarly journals The principal magnetic susceptibilities of some paramagnetic crystals at low temperatures

1933 ◽  
Vol 140 (842) ◽  
pp. 695-713 ◽  
Keyword(s):  
Ammonium Sulphate ◽  
Low Temperatures ◽  
Room Temperature ◽  
Manganese Carbonate ◽  
Small Range ◽  
Restricted Range ◽  
Nickel Sulphate ◽  
Temperature Range ◽  
Naturally Occurring ◽  
Ferrous Carbonate

Our knowledge of the temperature variation of the principal susceptibilities of paramagnetic crystals is as yet fragmentary. The principal susceptibilities of a number of paramagnetic crystals have been determined by Finke and by Rabi at room temperature but the first measurements on orientated crystals over any range of temperature were those of Foëx. He has published the principal susceptibilities of siderose (a mineral which is mainly ferrous carbonate but which contains appreciable quantities of the carbonates of manganese and other metals) over the range 87° to 400°K. and some measurements but not actual principal susceptibilities for manganese sulphate, MnSO 4 .4H 2 O. The writer measured the principal susceptibilities of cobalt ammonium sulphate and nickel sulphate, NiSO 4 . 7H 2 O over the temperature range 14°-290°K. and the writer and de Haas have published measurements on manganese ammonium sulphate crystals over the restricted range 14°-20° K. In addition Dupouy has repeated Foëx’s observations on siderose and has measured the principal susceptibilities of dialogite (a naturally occurring manganese carbonate) and oligist (Fe 2 O 3 ), all over a small range of temperature above 0° C. Quite recently Bartlett has employed Rabi’s method to determine the principal susceptibilities of the following compounds, CoSO 4 . 7H 2 O, CoSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O, CoSO 4 . K 2 SO 4 . 6H 2 O, CuSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O CuSO 4 . K 2 SO 4 . 6H 2 O, NiSO 4 . (NH 4 ) 2 SO 4 . 6H 2 O over the temperature range —45° to +55°C. In the writer’s opinion, however, Bartlett’s procedure is liable to several objections.

MEASUREMENT OF THE VISCOSITY OF GASES OVER A LARGE TEMPERATURE RANGE

1932 ◽  
Vol 6 (4) ◽  
pp. 428-443 ◽  
Author(s):  
B. P. Sutherland ◽  
O. Maass
Keyword(s):  
Carbon Dioxide ◽  
Kinetic Theory ◽  
Experimental Error ◽  
Point Of View ◽  
Large Temperature ◽  
Theoretical Point ◽  
Accurate Data ◽  
Temperature Range ◽  
Damped Oscillations ◽  
Disk Method

The work described is an investigation of the viscosity of air, hydrogen and carbon dioxide. The principle of damped oscillations was employed and an apparatus was built embodying many new features which make possible an accuracy greater than has hitherto been obtained. It was the attempt at the elimination of experimental error in the oscillating disk method which was the main feature of the investigation. At room temperatures where values in the literature are reliable excellent agreement with the best data has been obtained, but at lower temperatures where there is much divergence in published values the present results are of importance as giving more reliable and accurate data than hitherto available. For hydrogen and air the temperature range +20° to −200 °C. was covered. In the case of carbon dioxide the range was limited by its properties to +20 to −95 °C. As the temperature coefficient of the viscosity of gases is of particular interest from a theoretical point of view, as far as the kinetic theory is concerned, the data obtained may be considered important. Incidentally, Maxwell's law concerning the effect of pressure on viscosity was confirmed at the lowest temperature range hitherto investigated.

Applications: Light My Fire

1982 ◽  
Vol 75 (1) ◽  
pp. 53-55
Author(s):  
George Knill ◽  
George Fawceti
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Low Temperatures ◽  
Chemical Process ◽  
Room Temperature ◽  
Very High

Everyone knows that wood bums at a very high temperature. This burning is a chemical process that combines oxygen and carbon. The process occurs at very low temperatures as well as at very high ones. At high temperatures the process is spectacular-fire. At low temperatures (room temperature) you won’t even notice it, although it is still going on. Wood is always burning.

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.

Survival of the first-stage larvae and infective larvae of Bunostomum trigonocephalum Rudolphi, 1808

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 551-558 ◽  
Author(s):  
Bandana Narain
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Room Temperature ◽  
Tap Water ◽  
Scientific Research ◽  
Research Committee ◽  
Free Living ◽  
Larval Stages ◽  
Infective Larvae ◽  
Laboratory Facilities

The free-living larval stages of Bunostomum trigonocephalum are better adapted to low temperatures than high temperatures. Most survived at 10°C.In tap water, 1st-stage larvae survived for 11 days at 0°C, 17 days at 5°C, 20 days at 10°C, 15 days at 15°C, 18 days at 20°C, 15 days at 25°C, 9 days at 30°C, 7 days at 34°C, 4 days at 35°C, 16 h at 40°C, 40 min at 45°C and 20 min at 50°C.In tap water infective larvae survived for 40 days at 0°C, 70 days at 5°C, 100 days at 10 and 15°C. 65 days at 20°C, 48 days at 25°C, 38 days at 30°C, 14 days at 34°C, 6 days at 35°C, 5 days at 40°C, 3 h at 45°C and 105 min at 50°C.In tap water at room temperature infective larvae survived for 26 days in January, 20 days in February, 21 days in March, 13 days in April, 10 days in May, 6 days in June, 9 days in July and August, 11 days in September, 12 days in October, 14 days in November and 17 days in December.I thank Professor M. B. Lal for his interest and for providing laboratory facilities in the Department of Zoology, University of Lucknow; Dr Premvati for guidance; and the Scientific Research Committee, U.P., India, for financial help.

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