Nasal Mucosal Temperature after Exposure to Cold, Dry Air and Hot, Humid Air

2003 ◽  
Vol 123 (7) ◽  
pp. 851-856 ◽  
Author(s):  
Kristina Liener ◽  
Richard Leiacker ◽  
Jörg Lidemann ◽  
Gerhard Rettinger ◽  
Tilman Keck
Keyword(s):  
Dry Air ◽  
Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 952 ◽  
Author(s):  
Wangi Sari ◽  
Simon Leigh ◽  
James Covington

In this paper we report on the development tungsten oxide based chemiresistive sensors for the monitoring of oxygen at low temperatures (T ≤ 400 °C) in dry and humid air. The sensors were deposited onto alumina substrate by a combination of spin coating and a photolithographic process to define the sensing area. Our results show that the sensors comply with a linear relationship over a 0 to 20% concentration range, with a high response towards oxygen. The highest response was observed at 350 °C (ΔR/Ra = 7.8) in humid and in dry air (ΔR/Ra = 18). This result is a significant improvement over our previous experiments and we believe to take the concept of a metal-oxide based oxygen sensor a step closer.


CORROSION ◽  
1966 ◽  
Vol 22 (10) ◽  
pp. 291-293 ◽  
Author(s):  
VERNON A. NIEBERLEIN

Abstract Vapor-deposition is being used increasingly for fabricating complex shapes from tungsten. In contrast to conventional tungsten whose oxidation kinetics have been well explored, vapor-deposited material has never been investigated systematically with regard to oxidation. Oxidation rates were run at 600–1000 C (1112–1832 F) in air using a recording balance. Activation energies were calculated and oxidation rates were compared to those of sheet tungsten prepared using powder metallurgy techniques. Humid air and dry air were compared as corroding media.


1987 ◽  
Vol 62 (2) ◽  
pp. 526-532 ◽  
Author(s):  
E. M. Baile ◽  
R. W. Dahlby ◽  
B. R. Wiggs ◽  
G. H. Parsons ◽  
P. D. Pare

Tracheobronchial blood flow increases with cold air hyperventilation in the dog. The present study was designed to determine whether the cooling or the drying of the airway mucosa was the principal stimulus for this response. Six anesthetized dogs (group 1) were subjected to four periods of eucapnic hyperventilation for 30 min with warm humid air [100% relative humidity (rh)], cold dry air (-12 degrees C, 0% rh), warm humid air, and warm dry air (43 degrees C, 0% rh). Five minutes before the end of each period of hyperventilation, tracheal and central airway blood flow was determined using four differently labeled 15-micron diam radioactive microspheres. We studied another three dogs (group 2) in which 15- and 50-micron microspheres were injected simultaneously to determine whether there were any arteriovenous communications in the bronchovasculature greater than 15 micron diam. After the last measurements had been made, all dogs were killed, and the lungs, including the trachea, were excised and blood flow to the trachea, left lung bronchi, and parenchyma was calculated. Warm dry air hyperventilation produced a consistently greater increase in tracheobronchial blood flow (P less than 0.01) than cold dry air hyperventilation, despite the fact that there was a smaller fall (6 degrees C) in tracheal tissue temperature during warm dry air hyperventilation than during cold dry air hyperventilation (11 degrees C), suggesting that drying may be a more important stimulus than cold for increasing airway blood flow. In group 2, the 15-micron microspheres accurately reflected the distribution of airway blood flow but did not always give reliable measurements of parenchymal blood flow.


1987 ◽  
Vol 62 (2) ◽  
pp. 520-525 ◽  
Author(s):  
E. M. Baile ◽  
S. Osborne ◽  
P. D. Pare

Tracheobronchial blood flow increases two to five times in response to cold and warm dry air hyperventilation in anesthetized tracheostomized dogs. In this series of experiments we have attempted to attenuate this increase by blockade of the autonomic nervous system. Four groups of anesthetized, tracheostomized, open-chest dogs were studied. Group 1 (n = 5) were hyperventilated for 30 min with 1) warm humid [approximately 26 degrees C, 100% relative humidity, (rh)] air followed by bilateral vagotomy, 2) warm humid air, 3) cold (-22 degrees C, 0% rh) dry air, and 4) warm humid air. Groups 2, 3, and 4 (n = 3/group) were hyperventilated for 30 min with 1) warm humid (approximately 41 degrees C, 100% rh) air, 2) warm dry (approximately 41 degrees C) air, 3) warm humid air, and 4) warm dry air. Group 2 were controls. Group 3 were given phentolamine, 0.6 mg/kg intravenously, as an alpha-blockade, and group 4 were given propranolol, 1 mg/kg, as a beta-blockade after warm dry air hyperventilation (period 2). Five minutes before the end of each 30-min period of hyperventilation, measurements of vascular pressures, cardiac output, arterial blood gases, and inspired, body, and tracheal temperatures were measured, and differently labeled radioactive microspheres were injected into the left atrium to make separate measurements of airway blood flow. After the last measurements had been made animals were killed and their lungs were excised. Blood flow to the airways and lung parenchyma was calculated.(ABSTRACT TRUNCATED AT 250 WORDS)


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1095
Author(s):  
Liang Hao ◽  
Tuanjie Li ◽  
Zhongliang Xie ◽  
Qingjuan Duan ◽  
Guoyuan Zhang

Indefinite chill (IC) roll and high speed steel (HSS) materials have been widely employed to manufacture work rolls as latter and former stands in hot rolling mills. The oxidation of work rolls is of importance for the surface quality of the rolled workpieces. The isothermal oxidation of the IC and HSS materials was conducted at 650 °C and 700 °C in both dry air and humid air. The isothermal oxidation curves indicate that HSS shows faster kinetics than the IC materials in dry air, whereas the opposite occurred in humid air. The oxide scales of the IC materials after the oxidation in both dry air and humid air are made up of two oxide phases. Two oxide phases were found when the HSS oxidized in the dry air and three oxide phases were found when oxidized in the humid air.


Author(s):  
Elie Acayanka ◽  
Samuel Laminsi ◽  
Peter Teke Ndifon ◽  
Sop Tamo Berthelot ◽  
Jean-Louis Brisset

AbstractDithizone is an extracting agent largely used for metallurgical processes and has been found in waste waters. Its degradation is studied by exposing basic solutions to a gliding arc discharge burning in various gases (i.e., humid and dry air, humid air and tert-butanol) to underline the role of the formed °OH radicals and H


1863 ◽  
Vol 12 ◽  
pp. 326-327

The object of this paper is to prove to meteorologists that they may apply, without misgiving, the results which the author has already announced, regarding the relation of aqueous vapour to radiant heat. The author describes new experiments made with dry and humid air, first, with an experimental tube stopped by plates of rock-salt; secondly, with an open experimental tube; and thirdly, with an arrangement in which both the plates and the tube were abandoned, dry air being caused to displace moist, and moist air dry, in the open aitmosphere.


2020 ◽  
Author(s):  
Alejandro Malagón-Romero ◽  
Alejandro Luque

<p>Long spark discharges of about one meter and natural lightning show a polarity asymmetry.  While positive discharges propagate continuously, negative discharges propagate in a stepped manner. This stepped propagation is mediated by the so-called space stem, an isolated region in the streamer corona of depleted electron density and enhanced electric field. Kostinskiy et al. 2018 [1] reported the stepping of positive leaders under high humidity conditions and Malagón-Romero et al. 2019 [2] showed that positive leader steps, if they exist, would be shorter and thus harder to observe in experiments. </p><p>In this work we present the results of our simulations for the evolution of a space stem precursor [2] under dry and humid air conditions. These results show that the presence of water molecules enhances the electric field and the heating rate of the space stem, reaching 2000 K considerably faster than in dry air. This could make feasible the stepping of positive leader discharges under high humidity conditions as observed by Kostinskiy et al. 2018 [1].</p><p> </p><p>[1] Kostinskiy, A. Y., Syssoev, V. S., Bogatov, N. A., Mareev, E. A., Andreev, M. G., Bulatov, M. U., & Rakov, V. A. (2018). Abrupt elongation (stepping) of negative and positive leaders culminating in an intense corona streamer burst: Observations in long sparks and implications for lightning. Journal of Geophysical Research: Atmospheres, 123, 5360–5375. </p><p>[2] Malagón-Romero, A., & Luque, A. (2019). Spontaneous emergence of space stems ahead of negative leaders in lightning and long sparks. Geophysical Research Letters, 46, 4029–4038. https://doi.org/10.1029/ 2019GL082063</p>


1988 ◽  
Vol 65 (5) ◽  
pp. 1990-1994 ◽  
Author(s):  
D. J. Godden ◽  
E. M. Baile ◽  
M. Okazawa ◽  
P. D. Pare

Tracheobronchial blood flow in dogs increases with cold or dry air hyperventilation, possibly as a result of airway drying leading to increased osmolarity of airway surface fluid. This study was designed to examine whether administration of aerosols of various tonicity to alter airway surface fluid osmolarity would induce similar blood flow changes. Tracheobronchial blood flow was measured by the radioactive microsphere technique in six anesthetized dogs ventilated with warm humid air (100% relative humidity) for 15 min (period 1), air containing ultrasonically nebulized saline aerosol (1,711 mosmol/kg) for 3 min (period 2) and 12 min (period 3), and the same aerosol at a higher nebulizer output for a further 3 min (period 4). Between periods 3 and 4, the dogs were ventilated with warm humid air for 30 min to reestablish base-line conditions. In another five dogs, measurements were made after 30 min of ventilation with 1) warm humid air, 2) isotonic saline aerosol, 3) warm humid air, 4) distilled water aerosol (3 dogs), and hypertonic saline aerosol (2 dogs). After the last measurement was made, each dog was killed, the trachea and major bronchi were excised, and blood flow was calculated. No change in blood flow was found during any period of aerosol inhalation. The osmolar load imposed on the airways was estimated and was similar to that occurring during cold or dry air hyperventilation. These data suggest that increasing osmolarity of airway surface fluid does not explain the blood flow changes seen during hyperventilation of cold or dry air.


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