scholarly journals The mean condensate heat resistance of dropwise condensation with flowing, inert gases

1995 ◽  
Vol 30 (6) ◽  
pp. 435-445 ◽  
Author(s):  
C. W. M. van der Geld ◽  
H. J. H. Brouwers
Keyword(s):  
Heat Resistance ◽  
Inert Gases ◽  
Dropwise Condensation ◽  
The Mean

Effect of Aerogel Incorporation in PCM-Containing Thermal Liner of Firefighting Garment

2018 ◽  
Vol 36 (3) ◽  
pp. 151-164 ◽  
Author(s):  
Abu Shaid ◽  
Lijing Wang ◽  
Stanley M. Fergusson ◽  
Rajiv Padhye
Keyword(s):  
Thermal Properties ◽  
Thermal Resistance ◽  
Heat Resistance ◽  
Phase Change ◽  
Phase Change Material ◽  
Protective Clothing ◽  
Ignition Time ◽  
Current Case ◽  
The Mean ◽  
Change Material

Phase change material (PCM) in firefighting garment enhances protection and comfort. Wearing a protective clothing containing PCM, while fighting the fire, is a direct risk to the wearer as most PCMs used are flammable. This article reports a solution by using aerogel. Thermal liner fabric was treated with PCM and/or aerogel and then their thermal properties were analyzed. It has been found that the mean ignition time of PCM-containing thermal liner is around 3.3 s in current case while this value significantly increased to 5.5 s when the combination of aerogel and PCM was used. Moreover, the weight of the liner fabric with aerogel decreased in comparison to PCM-containing liner. Aerogel also slowed down the spreading of flame in PCM-containing fabric. Aerogel–coated liner showed superior heat resistance and the combination of aerogel with PCM increased the thermal resistance of PCM-containing liner.

Effect of Inverse I 

1998 ◽  
Vol 88 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Elizabeth Zavala ◽  
Miguel Ferrer ◽  
Guido Polese ◽  
Joan Ramon Masclans ◽  
Merce Planas ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Gases ◽  
Conventional Mechanical Ventilation ◽  
Inert Gases ◽  
Lung Mechanics ◽  
The Mean ◽  
The Right ◽  
Volume Controlled ◽  
Pressure Controlled

Background It is not known whether inverse I:E ratio ventilation (IRV) offers any real benefit over conventional mechanical ventilation with positive end-expiratory pressure (CMV-PEEP) at similar levels of end-expiratory pressure. Methods The effects of volume-controlled and pressure-controlled IRV (VC-IRV and PC-IRV, respectively) on VA/Q inequality were compared with those of CMV-PEEP at a similar level of end-expiratory pressure and with CMV without PEEP (CMV) in eight patients in the early stages of acute respiratory distress syndrome (ARDS). Respiratory blood gases, inert gases, lung mechanics, and hemodynamics were measured 30 min after the onset of each ventilatory mode. Results Recruitment of nonventilated, poorly ventilated (or both) but well-perfused alveoli increased the partial pressure of oxygen (PaO2) during CMV-PEEP (+13 mmHg) and IRV-VC (+10 mmHg; P < 0.05) compared with CMV. In contrast, PC-IRV did not affect PaO2 but caused a decrease in PaCO2 (-7 mmHg; P < 0.05). The latter was due to a concomitant decrease in dead space (P < 0.01) and shift to the right of VA/Q distributions. During PC-IRV, the increase in the mean of blood flow distribution (mean Q; P < 0.01) without a change in the dispersion (log SD Q) did not result in an increase in PaO2, probably because it reflected redistribution of blood flow within well-ventilated areas. Conclusions Short-term PC-IRV improved carbon dioxide clearance, but the lung became less efficient as an oxygen exchanger. Furthermore, based on mean airway and plateau pressures, the risk of barotrauma was not reduced with this type of ventilation.

scholarly journals Morphological Study of Heat-Sensitive and Heat-Resistant Spores of Clostridium sporogenes, Using Transmission Electron Microscopy

2008 ◽  
Vol 71 (5) ◽  
pp. 953-958 ◽  
Author(s):  
JAE-HYUNG MAH ◽  
DONG-HYUN KANG ◽  
JUMING TANG
Keyword(s):  
Heat Resistance ◽  
Structural Components ◽  
Structural Determinants ◽  
Clostridium Sporogenes ◽  
The Core ◽  
Heat Resistant ◽  
Transmission Electron ◽  
Thickness Standard ◽  
The Mean ◽  
Coat Layer

To investigate the primary structural determinants affecting heat resistance of Clostridium sporogenes spores, electron micrographs of heat-sensitive (D121°C = 0.56 min) and heat-resistant (D121°C = 0.93 min) spores of C. sporogenes were taken with a transmission electron microscope. The mean thickness (± standard deviation [SD]) of coat layers and cortex regions of heat-sensitive spores were 82.9 ± 14.5 and 86.0 ± 22.7 nm, while those of heat-resistant spores were 106.9 ± 45.7 and 111.7 ± 32.1 nm, respectively. The thickness of coat (P = 0.031) and cortex (P = 0.006) showed statistically significant differences, suggesting that heat-resistant spores have a thicker coat and cortex than do heat-sensitive spores. The mean sizes (± SD) of cores were 467.0 ± 88.7 nm for heat-sensitive spores and 460.2 ± 98.5 nm for heat-resistant spores, respectively, which showed no statistically significant differences. The ratios (± SD) of the core size to the sporoplast size were 0.84 ± 0.05 for heat-sensitive spores and 0.80 ± 0.07 for heat-resistant spores, respectively, showing statistically significant differences (P = 0.030), which indicated that the ratio is negatively related to heat resistance. Accordingly, the structural components of heat-sensitive spores were severely damaged by heat treatment, whereas those of heat-resistant spores were unlysed under the same conditions. Based on the structural analyses of spores, it was elucidated that the thickness of coat layer and cortex region are significantly correlated with heat resistance of C. sporogenes spores, and that cortex region plays a major role in protecting the spore from heat damage.

scholarly journals The thermal diffusion of radon gas mixtures

1942 ◽  
Vol 181 (984) ◽  
pp. 93-100 ◽  
Keyword(s):  
Force Field ◽  
Thermal Diffusion ◽  
Special Theory ◽  
Mean Value ◽  
Repulsive Force ◽  
Inert Gases ◽  
Inert Gas ◽  
Cold Side ◽  
The Mean ◽  
Gas Molecules

In continuation of earlier experiments (Harrison 1937) in which the thermal diffusion in radon-hydrogen and radon-helium mixtures was measured, the thermal diffusion of mixtures of radon-neon and radon-argon has now been studied. The mean value obtained for the ratio of the proportion by volume of radon on the cold side at 0° C to that on the hot side at 100° C, after thermal diffusion, was 1·074 for radon-neon mixtures, and 1·008 for radon-argon mixtures. In order to calculate the repulsive force field, F 12 , between these two pairs of molecules, the present results were combined with measurements of ordinary diffiisirm of radon into neon and radon into argon (Hirst & Harrison 1939), and viscosity determinations at various temperatures of neon and argon (Trautz & Binkele 1930). The special theory, due to Chapman (1929), of thermal diffusion of a rare constituent in a binary mixture was used to derive Flt. The values obtained for the repulsive force field between the dissimilar molecules at collision were: F 12 (radon-neon) = 1·9 x 10 -51 d -6·1 = ( d / d 0 ) -6·1 , d 0 = 4·8 x 10 -9 , F 12 (radon-argon) = 2·1 x 10 -43 d -5·1 = ( d 0 )-5·1 , d 0 = 4·3 x 10 -9 , d being the distance between the point centres of repulsive force and d 0 the value of d at which F 12 is 1 dyne. A comparison of the values obtained for the repulsive force index for radon-neon and radon-argon molecules with those obtained by Atkins, Bastick & Ibbs (1939) for binary mixtures of the first five inert gases shows that radon is the4 softest ’ of the inert gas molecules. Radon-argon molecules are the closest approach to the Maxwellian case yet studied experimentally.

scholarly journals Структура призондового слоя в газоразрядной плазме при произвольной ориентации плоского зонда относительно электрического поля в плазме

2019 ◽  
Vol 89 (10) ◽  
pp. 1545
Author(s):  
O. Мурильо ◽  
А.С. Мустафаев ◽  
В.С. Сухомлинов
Keyword(s):  
Electric Field ◽  
Electron Energy ◽  
Exchange Process ◽  
Mean Free Path ◽  
Ionization Rate ◽  
Inert Gases ◽  
Mutual Orientation ◽  
Mean Velocity ◽  
Charge Exchange Process ◽  
The Mean

AbstractWe investigate the structure of the wall sheath of a gas discharge near a flat surface at a negative potential for high mean electron energy. It is shown that in the conditions where the mean energy of ions in the plasma is much lower than the mean electron energy, the parameters of the wall sheath weakly depend on the mutual orientation of the normal to the surface and the electric field in the plasma for an arbitrary ratio of the Debye radius to the ion mean free path relative to the resonant charge exchange process. It is found that for inert gases (He, Ar) for ratio E / P of the electric field to pressure exceeding 10 V/(cm Torr) in the plasma, the disregard of ionization in the perturbed wall sheath can lead to substantial errors in the calculation of its parameters. It is shown that the ionization leads to an increase in the electric field in the wall sheath and, as a consequence, to an increase in the mean velocity of ions at the boundary between the quasi-neutral presheath and the part of the perturbed wall sheath in which quasi-neutrality is substantially violated. The parameters of the wall sheath where quasi-neutrality is significantly violated depend on the ionization rate much less strongly than the corresponding parameters of the quasi-neutral presheath. We have determined the relation for concentration of charged particles in the unperturbed plasma from the ion saturation current considering the actual ion energy distribution function in the plasma as well as ionization in the presheath and the part of the perturbed wall sheath in which quasi-neutrality is violated significantly.

Variations in heat resistance of ecotypes of Eucalyptus camaldulensis Dehn. and their significance

1971 ◽  
Vol 19 (3) ◽  
pp. 261 ◽  
Author(s):  
R Karschon ◽  
L Pinchas
Keyword(s):  
Heat Resistance ◽  
Eucalyptus Camaldulensis ◽  
Seed Source ◽  
Maximum Temperature ◽  
Natural Habitats ◽  
Leaf Surfaces ◽  
The Mean ◽  
Wax Deposits ◽  
Resistance Value ◽  
Seed Provenance

Depending upon the seed provenance, the heat resistance value of leaves of E. carnaldulensis varies from 47.4 to 50.0°C. It is not related to the mean maximum temperature of the hottest month at the seed source. The relation of heat resistance to wax deposits, colour, and temperatures of leaf surfaces is examined. The implications of the findings in the phylogeny and ecotypic divergence of the species and its cultivation outside its natural habitats in Australia are discussed.

Heat Resistance of Clostridium botulinum Type B Spores Grown from Isolates from Commercially Canned Mushrooms1

1978 ◽  
Vol 41 (5) ◽  
pp. 351-353 ◽  
Author(s):  
THERON E. ODLAUG ◽  
IRVING J. PFLUG ◽  
DONALD A. KAUTTER
Keyword(s):  
Heat Resistance ◽  
Phosphate Buffer ◽  
Clostridium Botulinum ◽  
Type B ◽  
Botulinum Type ◽  
C Value ◽  
The Mean ◽  
D Values

The heat resistance of ten Clostridium botulinum type B spore crops was determined in mushroom puree and 0.067M Sorenson phosphate buffer (pH 7). The spore crops were grown from Clostridium botulinum isolates obtained from commercially canned mushrooms. The D-values for all of the C. botulinum spore crops were overall slightly higher in the buffer than in mushroom puree. The mean D(110.0 C)-value for the ten spore crops in buffer was 1.17 min and for the spores in mushroom puree the mean D(110.0 C)-value was 0.78 min. The mean D(115.6 C)-value in buffer for the ten spore crops was 0.24 min compared to a mean D(115.6 C)-value of 0.19 min for spores in mushroom puree. The C. botulinum type B spores tested in this study had a heat resistance that was less than the classical heat resistance for C. botulinum spores.

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