Sweating in cattle. III. Mechanism of water transportation through the skin

1959 ◽  
Vol 52 (1) ◽  
pp. 62-65 ◽  
Author(s):  
G. C. Taneja
Keyword(s):  
Water Vapour ◽  
Vapour Pressure ◽  
Pressure Difference ◽  
Water Vapour Pressure ◽  
Atmospheric Conditions ◽  
Water Transportation ◽  
Saturated Water ◽  
The Difference ◽  
Cutaneous Evaporation ◽  
Vapour Pressure Difference

Two calves (Zebu × Australian Illawara Shorthorn and Shorthorn) of about 7–8 months of age were exposed to controlled atmospheric conditions. Cutaneous evaporation from the belly area of these calves was measured by the capsule method. Records of the temperature of the skin under test and that of the air passed over the skin was also maintained.The amount of water passing through the cattle skin was proportional to the difference between the saturated water-vapour pressure at skin temperature and the water-vapour pressure in the air. Tests were made for the water-vapour pressure difference varying from 9 to 25 mm. Hg.

Sweating in sheep

1960 ◽  
Vol 11 (4) ◽  
pp. 557 ◽  
Author(s):  
AH Brook ◽  
BF Short
Keyword(s):  
Weight Gain ◽  
Water Vapour ◽  
Vapour Pressure ◽  
Water Movement ◽  
Maximum Amount ◽  
Sweat Glands ◽  
Water Vapour Pressure ◽  
Average Weight ◽  
The Difference ◽  
Average Weight Gain

Water loss from the sweat glands of shorn sheep was estimated as the difference between the average weight gain of desiccating capsules placed on 10 normal sheep and on 4 control sheep congenitally lacking sweat glands. At an air tempera ture of 20°C (68°F) and a water vapour pressure of 12.5 mm Hg the rate of svveating was 10.2 g/m2/hr, and at 40°C (104°F) and a water vapour pressure of 28.1 mm Hg the rate of sweating was 32.1 g/m2/hr. The maximum amount of heat a sheep could lose by sweating at the rate of 32 g/m2/hr under these conditions is c. 20 kcal/hr. It is emphasized that the rate of sweating observed in shorn sheep must not be applied unreservedly to sheep with a fleece, because the dynamics of water movement in the fleece are unknown.

scholarly journals The transpiration and respiration as mechanisms of water loss in cold storage of figs

Food Research ◽  
2021 ◽  
Vol 5 (6) ◽  
pp. 109-118
Author(s):  
D. Lentzou ◽  
G. Xanthopoulos ◽  
C. Templalexis ◽  
A. Kaltsa
Keyword(s):  
Relative Humidity ◽  
Water Vapour ◽  
Cold Storage ◽  
Water Loss ◽  
Vapour Pressure ◽  
Vapour Pressure Deficit ◽  
Agricultural Products ◽  
Water Vapour Pressure ◽  
The Difference ◽  
Water Vapour Pressure Deficit

Transpiration and respiration are two mechanisms of water loss in fresh agricultural products, resulting in visual and texture degradation. Neglecting respiration as a mechanism of water loss may lead to erroneous results at saturation where water vapour pressure deficit is zero and thus water loss is expected to be zero, however, the existence of a finite water loss is noted. In this context, an analysis of the associated with transpiration and respiration water loss in figs (Ficus carica L.) was carried out at 0oC, 10oC and 20oC and 45.64%, 80.22% and 98.65% relative humidity as well as the air conditions of walk-in cold storage rooms. The estimated transpiration rate ranged between 0.11-1.416 mg cm-2 h -1 for a water vapour pressure deficit of 0.0-0.98 kPa. The water vapour pressure deficit estimation was based on the difference between cold air temperature and figs’ surface temperature. The respiration rate was calculated at 0oC, 10oC and 20oC as 0.47±0.08, 0.94±0.11 and 2.69±0.17 mLCO2100g-1 h -1 . Quantification of the water loss showed that at 20oC and saturation, the water loss due to respiration accounts for 3.9% of the respective water loss due to water vapour pressure deficit while on average, the water loss due to respiration accounts for 1.5%, 2.1% and 2.6% of the water loss due to water vapour pressure deficit at 0oC, 10oC and 20oC.

(Ton)silly seasons? Do atmospheric conditions actually affect post-tonsillectomy secondary haemorrhage rates?

2015 ◽  
Vol 129 (7) ◽  
pp. 702-705 ◽  
Author(s):  
B Cadd ◽  
M Rogers ◽  
H Patel ◽  
G Crossland
Keyword(s):  
Water Vapour ◽  
Vapour Pressure ◽  
Water Vapour Pressure ◽  
Atmospheric Conditions ◽  
Common Procedure ◽  
Bleeding Rate ◽  
Local Climate ◽  
Life Threatening ◽  
Secondary Haemorrhage ◽  
Haemorrhage Rate

AbstractBackground:Tonsillectomy is a common procedure, with potentially life-threatening complications. Previous investigations into post-tonsillectomy secondary haemorrhage rates suggest an influence of climactic and atmospheric conditions on haemorrhage rate, particularly temperature and water vapour pressure. With a single emergency department and a large variance in atmospheric conditions, Darwin, Australia, is ideal for investigating the effects of local climate on rates of post-operative haemorrhage.Methods:A five-year retrospective review was conducted of all tonsillectomy procedures performed between 2008 and 2013. Effects of atmospheric variables were examined using Pearson's correlation coefficient and analysis of variance.Results:A total of 941 patients underwent tonsillectomy in the study period. The bleeding rate was 7.7 per cent. No variation was found between wet and dry season tonsillectomies (p= 0.4). Temperature (p= 0.74), water vapour pressure (p= 0.94) and humidity (p= 0.66) had no effect on bleeding.Conclusion:The findings revealed no correlation between humidity, season, water vapour pressure and haemorrhage rates. Further research should use multi-site data to investigate the effect of air conditioning, humidification and climactic conditions between different regions in Australia.

Water vapour pressure above saturated salt solutions at low temperatures

1999 ◽  
Vol 155 (2) ◽  
pp. 297-309 ◽  
Author(s):  
V Morillon ◽  
F Debeaufort ◽  
J Jose ◽  
J.F Tharrault ◽  
M Capelle ◽  
...  
Keyword(s):  
Water Vapour ◽  
Vapour Pressure ◽  
Low Temperatures ◽  
Water Vapour Pressure ◽  
Salt Solutions

The Study of Evaporation from Small Surfaces by the Direct Measurement of Water Vapour Pressure Gradients

1970 ◽  
Vol 53 (3) ◽  
pp. 753-762
Author(s):  
JOHN MACHIN
Keyword(s):  
Water Vapour ◽  
Direct Measurement ◽  
Vapour Pressure ◽  
Point Method ◽  
Dew Point ◽  
Water Vapour Pressure ◽  
Pressure Gradients ◽  
Pressure Measurements ◽  
Wind Speeds ◽  
Experimental Values

1. The construction, maintenance and calibration of a sensitive instrument capable of making numerous vapour-pressure measurements within humidity gradients by the dew-point method is described. 2. Coefficients of diffusion of water vapour in air, calculated from observed vapour-pressure gradients and measured rates of evaporation agree with theoretical and other experimental values in still air. 3. Apparent coefficients in wind speeds between 10 and 100 cm/s were significantly lower than those in still air. 4. This finding, together with the performance of the dew-point probe, is discussed in relation to its possible use in the study of evaporation from animals and plants.

scholarly journals Properties of hydrated TiO2 and SiO2 nanoclusters: dependence on size, temperature and water vapour pressure

Nanoscale ◽  
2018 ◽  
Vol 10 (45) ◽  
pp. 21518-21532 ◽  
Author(s):  
Andi Cuko ◽  
Antoni Macià Escatllar ◽  
Monica Calatayud ◽  
Stefan T. Bromley
Keyword(s):  
Water Vapour ◽  
Systematic Study ◽  
Vapour Pressure ◽  
Water Vapour Pressure ◽  
Nano Silica

The stabilities and properties of globally optimised (TiO2)M(H2O)N and (SiO2)M(H2O)N clusters with M = 4–16 and a range of N/M ratios are studied with respect temperature and water vapour pressure. Our systematic study provides a comparative reference for understanding hydration of nano-silica and nano-titania.

Study of the reaction CaSO4.½H2O (β-hemihydrate) = CaSO4 (β-soluble anhydrite)+½H2O in the temperature range 20–100° C

1965 ◽  
Vol 34 (268) ◽  
pp. 327-345 ◽  
Author(s):  
J. D. C. McConnell
Keyword(s):  
Water Vapour ◽  
Vapour Pressure ◽  
Physical Adsorption ◽  
Linear Increase ◽  
Water Vapour Pressure ◽  
Hydration Reaction ◽  
Temperature Range ◽  
Dehydration Reactions ◽  
Adsorption Of Water ◽  
Hydration And Dehydration

SummaryA thermogravimetric vacuum microbalance has been used to study the reaction between β-soluble anhydrite and water vapour in the temperature range 20–100° C. Equilibrium water-vapour pressures for the hydration reaction in this temperature range were determined directly and have been compared with available data obtained by Kelly, Southard, and Anderson (1941) in the temperature range 80–120° C. The kinetics of the hydration and dehydration reactions have also been studied in a series of isothermal experiments with varying water-vapour pressure. These experiments indicate that in a vapour-pressure range close to the equilibrium value very low rates for both hydration and dehydration are observed. Outside this range of vapour pressures both hydration and dehydration rates increase suddenly and show an approximately linear increase with imposed water-vapour pressure.At low temperatures (25° C) the dehydration reaction has an associated activation energy of approximately 10 kcal mole−1. In the same temperature range additional, physical adsorption of water vapour by the specimen was noted.

Techniques and Applications for Imaging Biological Samples in a Low Vacuum Environmental Scanning Electron Microscope

2001 ◽  
Vol 7 (S2) ◽  
pp. 782-783
Author(s):  
C. J. Gilpin.
Keyword(s):  
Water Vapour ◽  
Biological Samples ◽  
Vapour Pressure ◽  
Water Vapour Pressure ◽  
Environmental Scanning ◽  
Sample Collection ◽  
Electron Microscopes ◽  
A Site ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Of all the commercially available scanning electron microscopes which operate at “low vacuum” the ESEM is the most suitable for examining biological samples. in order to maintain samples with liquid water present the specimen chamber must be capable of operating at a pressure of at least 4.6 Torr (611 pascals) of water vapour pressure (the vapour pressure of water at 0°C). Use of lower pressures or a chamber gas other than water vapour will result in evaporation of water from the sample at a rate dependant on the partial pressure difference between the sample and its surrounding environment. Tables of relative humidity as a function of water vapour pressure and temperature are readily available to calculate desired settings for the microscope.One of the difficulties associated with examining fresh biological material is the need to have the microscope and sample available in the same location at the same time.If sample collection occurs at a site remote from the microscope inevitable necrotic changes will occur before examination can be carried out.

Sign in / Sign up

Export Citation Format

Share Document