scholarly journals The Temperature And Humidity Relations Of The Cockroach

1938 ◽  
Vol 15 (4) ◽  
pp. 555-563 ◽  
Author(s):  
D. L. GUNN ◽  
C. A. COSWAY
Keyword(s):  
Temperature Gradient ◽  
Temperature Reaction ◽  
Air Humidity ◽  
Moist Air ◽  
Uniform Temperature ◽  
Preferred Temperature ◽  
Dry Air ◽  
Blatta Orientalis ◽  
Temperature And Humidity ◽  
Humidity Reaction

1. In a diffusion gradient of humidity at uniform temperature, some cockroaches (Blatta orientalis, L.) show a tendency to spend more time in the drier region. Other individuals appear to be indifferent to the stimulus of air humidity. 2. On desiccation, there is a tendency for cockroaches to become hygro-positive. 3. In a temperature gradient, those individuals which react to humidity have a slightly but significantly higher preferred temperature in somewhat moist air than they have in dry air. 4. It seems, then, that the observed preferred temperature represents a kind of balance between a pure temperature reaction and a humidity reaction. The change in humidity reaction resulting from desiccation is qualitatively satisfactory to explain the fall in preferred temperature which occurs at the same time.

scholarly journals Influence of Air Humidity on Transonic Flows with Weak Shock Waves

2019 ◽  
Vol 29 (6) ◽  
pp. 1551-1557 ◽  
Author(s):  
Sławomir Dykas ◽  
Mirosław Majkut ◽  
Krystian Smołka
Keyword(s):  
Shock Waves ◽  
Transonic Flow ◽  
Weak Shock ◽  
Air Humidity ◽  
Moist Air ◽  
Cfd Simulations ◽  
Transonic Flows ◽  
Dry Air ◽  
Compressor Rotor ◽  
Modelling Approach

Abstract The paper presents CFD results for the transonic flow of dry and moist air through a diffuser and a compressor rotor. In both test geometries, i.e. the Sajben transonic diffuser and the NASA Rotor 37, the air humidity impact on the structure of flows with weak shock waves was examined. The CFD simulations were performed by means of an in-house CFD code, which was the RANS-based modelling approach to compressible flow solutions. It is shown that at high values of relative humidity, above 70%, the modelling of the transonic flow field with weak shock waves by means of the dry air model may produce wrong results.

scholarly journals The Temperature and Humidity Relations of the Cockroach

1942 ◽  
Vol 19 (2) ◽  
pp. 124-132
Author(s):  
D. L. GUNN ◽  
C. A. COSWAY
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Air Humidity ◽  
Moist Air ◽  
Original Weight ◽  
Temperature And Humidity

1. The carpet type of Barcroft respiration apparatus previously used by Gunn for cockroaches gives results comparable with those now obtained with a new basket type. 2. Desiccated cockroaches use oxygen at the same rate per animal as undesiccated specimens. If, however, the rates are calculated with reference to the weight of the animal at the time of the experiment, since the desiccated animals tested had lost about 25% of their original weight, their rates of oxygen consumption appeared to have gone up. 3. Both normal and desiccated animals used oxygen slightly faster in moist air than in dry. Part of this increase must be attributed to a higher body temperature in moist air at 25° C. than in drier air at 25° C. Part of it may be due to greater activity in moist air than in dry, slight though the activity was in both cases. 4. There is no reason to believe that, at a given body temperature, air humidity influences basal metabolic rate.

scholarly journals The Temperature and Humidity Relations of the cockroach

1936 ◽  
Vol 13 (1) ◽  
pp. 28-34
Author(s):  
DONALD L. GUNN ◽  
F. B. NOTLEY
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Moist Air ◽  
Dry Air ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Ecological Importance

1. The thermal death-points of three species of cockroaches in dry and in moist air have been determined for 1-day and 1-hour exposures. 2. Moist air is more favourable than dry in the longer exposures, because in dry air death occurs from desiccation when the temperature itself is not fatal. 3. Dry air is more favourable than moist in the shorter exposures, owing to the fact that the evaporation of water lowers the body temperature. 4. Bearing in mind the thermotactic behaviour of these animals, these observations would seem to have little ecological importance.

scholarly journals The Temperature and Humidity Relations of the Cockroach

1935 ◽  
Vol 12 (2) ◽  
pp. 185-190 ◽  
Author(s):  
D. L. GUNN
Keyword(s):  
Periplaneta Americana ◽  
Unit Surface Area ◽  
Ecological Significance ◽  
Preferred Temperature ◽  
Previous Conclusion ◽  
Blatella Germanica ◽  
Dry Air ◽  
Blatta Orientalis ◽  
Upper Limit ◽  
Unit Surface

1. The rates of desiccation of three species of cockroaches (Periplaneta americana, Blatta orientalis and Blatella germanica) in dry air at various temperatures have been compared (Fig. 1). There are clear specific differences. 2. The rates of respiration of the three species are proportional to the weight to the power of 0 75-0 8. 3. In all three species, at 30° C. in dry air the animal loses about 6 mg. of water by evaporation for every 1 mg. of oxygen consumed. The smallest species (Blatella germanica), with the thinnest cuticle, loses least rapidly per unit surface area. These facts are consistent with the previous conclusion that the water passes through both the spiracles and the cuticle. 4. The upper limit of preferred temperature of Periplaneta americana and Blatella germanica is 33° C, while for Blatta orientalis it is 29° C. The lower limit is not so sharply defined and further work is required before it can be regarded as significant. 5. Certain suggestions are made concerning the ecological significance of the observations described.

Effects of Temperature and Humidity of Inhaled Air on the Concentration of Ethanol in a Man's Exhaled Breath

1982 ◽  
Vol 63 (5) ◽  
pp. 441-445 ◽  
Author(s):  
A. W. Jones
Keyword(s):  
Ethanol Concentration ◽  
Ethanol Metabolism ◽  
Gas Liquid Chromatography ◽  
Exhaled Breath ◽  
Upper Respiratory Tract ◽  
Moist Air ◽  
Dry Air ◽  
Temperature And Humidity ◽  
Upper Respiratory ◽  
Effects Of Temperature

1. Ten healthy men each drank a moderate dose of ethanol in experiments to test if the temperature and moisture content of inhaled air could alter the concentration of ethanol in exhaled breath. 2. They breathed air at various temperatures and relative humidities (RH) for about 1 min before the concentration of ethanol and the temperature of end-expired breath were determined. Control breaths were analysed after the same men breathed ordinary room air (23°C, 55% RH). All tests were made during the postabsorptive phase of ethanol metabolism and the breath samples were analysed by gas-liquid chromatography. 3. When the men breathed cold dry air (5°C, 0% RH), the expired ethanol concentration decreased by 9·6 ± 0·69% (mean ± se) and breath temperature dropped by 1·40 ± 0·08°C. Cold moist air (5°C, 100% RH) decreased breath ethanol concentration by 6·4 ± 1·02% and breath temperature dropped by 1·1 ± 0·07°C. With hot dry air (80°C, 0% RH) as the breathing medium the concentration of ethanol was lowered by 4·3 ± 1·27% but expired breath temperatures were unchanged from the control tests. On breathing hot moist air (50°C, 100% RH), breath ethanol concentrations decreased by 10·3 ± 0·59%, even though breath temperatures rose by 1·8 ± 0·14°C above that of the controls. 4. Ethanol dissolves in the watery mucous membrane of the upper respiratory tract and can equilibrate with inhaled and exhaled air. It seems likely that during exchanges of heat and water vapour between respired air and the mucus, which largely depends on the temperature and humidity of inhaled air, the equilibrium of ethanol at the breath/mucus interface becomes disrupted. This leads to changes in the concentration of ethanol in expired air.

scholarly journals Post-Plasma Catalysis for Trichloroethylene Abatement with Ce-Doped Birnessite Downstream DC Corona Discharge Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 946
Author(s):  
Grêce Abdallah ◽  
Jean-Marc Giraudon ◽  
Rim Bitar ◽  
Nathalie De Geyter ◽  
Rino Morent ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Active Oxygen Species ◽  
Surface Acidity ◽  
Good Stability ◽  
Ozone Decomposition ◽  
Moist Air ◽  
Plasma Catalysis ◽  
Dry Air ◽  
Water Tolerance ◽  
By Products

Trichloroethylene (TCE) removal was investigated in a post-plasma catalysis (PPC) configuration in nearly dry air (RH = 0.7%) and moist air (RH = 15%), using, for non-thermal plasma (NTP), a 10-pin-to-plate negative DC corona discharge and, for PPC, Ce0.01Mn as a catalyst, calcined at 400 °C (Ce0.01Mn-400) or treated with nitric acid (Ce0.01Mn-AT). One of the key points was to take advantage of the ozone emitted from NTP as a potential source of active oxygen species for further oxidation, at a very low temperature (100 °C), of untreated TCE and of potential gaseous hazardous by-products from the NTP. The plasma-assisted Ce0.01Mn-AT catalyst presented the best CO2 yield in dry air, with minimization of the formation of gaseous chlorinated by-products. This result was attributed to the high level of oxygen vacancies with a higher amount of Mn3+, improved specific surface area and strong surface acidity. These features also allow the promotion of ozone decomposition efficiency. Both catalysts exhibited good stability towards chlorine. Ce0.01Mn-AT tested in moist air (RH = 15%) showed good stability as a function of time, indicating good water tolerance also.

Transport properties of real moist air, dry air, steam, and water

2021 ◽  
pp. 1-9
Author(s):  
Sebastian Herrmann ◽  
Hans-Joachim Kretzschmar ◽  
Vikrant C. Aute ◽  
Donald P. Gatley ◽  
Eckhard Vogel
Keyword(s):  
Transport Properties ◽  
Moist Air ◽  
Dry Air

scholarly journals A Study of Moist Air Condensation Characteristics in a Transonic Flow System

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4052
Author(s):  
Jie Wang ◽  
Hongfang Gu
Keyword(s):  
Mach Number ◽  
Relative Humidity ◽  
Transonic Flow ◽  
Flow System ◽  
Plane Surface ◽  
Droplet Growth ◽  
Moist Air ◽  
Dry Air ◽  
Hydraulic Equipment ◽  
Non Equilibrium

When water vapor in moist air reaches supersaturation in a transonic flow system, non-equilibrium condensation forms a large number of droplets which may adversely affect the operation of some thermal-hydraulic equipment. For a better understanding of this non-equilibrium condensing phenomenon, a numerical model is applied to analyze moist air condensation in a transonic flow system by using the theory of nucleation and droplet growth. The Benson model is adopted to correct the liquid-plane surface tension equation for realistic results. The results show that the distributions of pressure, temperature and Mach number in moist air are significantly different from those in dry air. The dry air model exaggerates the Mach number by 19% and reduces both the pressure and the temperature by 34% at the nozzle exit as compared with the moist air model. At a Laval nozzle, for example, the nucleation rate, droplet number and condensation rate increase significantly with increasing relative humidity. The results also reveal the fact that the number of condensate droplets increases rapidly when moist air reaches 60% relative humidity. These findings provide a fundamental approach to account for the effect of condensate droplet formation on moist gas in a transonic flow system.

scholarly journals DRIVEN DROPLETS BY THERMOCAPILLARY EFFECT: QUADRATIC DEPENDENCE OF THE SURFACE TENSION ON THE TEMPERATURE

Anales AFA ◽  
2020 ◽  
Vol 31 (3) ◽  
pp. 107-111
Author(s):  
J.R. Mac Intyre ◽  
◽  
J.M. Gomba ◽  
C. A. Perazzo ◽  
◽  
...  
Keyword(s):  
Surface Tension ◽  
Temperature Gradient ◽  
Present Article ◽  
Solid Surface ◽  
Linear Dependence ◽  
Complex Dynamics ◽  
Uniform Temperature ◽  
Thermocapillary Effect ◽  
Partial Wetting ◽  
Wetting Fluids

We study the migration of droplets on a solid surface which is under a uniform temperature gradient. The present article focus on partial wetting fluids which surface tension depends on the squared temperature. These type of liquids, called self-rewetting, show a complex dynamics and here we will compare with those liquids of linear dependence in the temperature. Unlike to the latter ones, the droplet width increases with the time.

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