scholarly journals Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m)

2021 ◽  
Vol 12 ◽  
Author(s):  
Ivan Lopez ◽  
Reinaldo Aravena ◽  
Daniel Soza ◽  
Alicia Morales ◽  
Silvia Riquelme ◽  
...  
Keyword(s):  
High Altitude ◽  
Pressure Swing Adsorption ◽  
Large Scale ◽  
High Mobility ◽  
Oxygen Enrichment ◽  
Oxygen Availability ◽  
Liquid Oxygen ◽  
High Altitudes ◽  
Pressure Swing ◽  
Very High

The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.

Oxygen enrichment by pressure swing adsorption

1988 ◽  
Vol 27 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Anthony S. T. Chiang ◽  
Mau Yeuh Hwong ◽  
Ting Yueh Lee ◽  
Tsao Wen Cheng
Keyword(s):  
Pressure Swing Adsorption ◽  
Oxygen Enrichment ◽  
Pressure Swing

Laying Eggs at High Altitude

Physiology ◽  
1988 ◽  
Vol 3 (2) ◽  
pp. 69-71 ◽  
Author(s):  
CC Monge ◽  
F Leon-Velarde ◽  
G Gomez de la Torre
Keyword(s):  
High Altitude ◽  
Water Loss ◽  
Oxygen Supply ◽  
The Other ◽  
High Altitudes ◽  
High Mountains ◽  
The One ◽  
Very High

The hypoxic and dry environment of the high mountains seems to select eggshells with porosities appropriate for the altitudinal level. At moderate altitudes, the conservation of water takes precedence over the oxygen-supply gradient. At very high altitudes there is a compromise between reducing water loss on the one hand and the defense of the oxygen supply to the embryo on the other.

Large-scale optimization strategies for pressure swing adsorption cycle synthesis

AIChE Journal ◽  
2012 ◽  
Vol 58 (12) ◽  
pp. 3777-3791 ◽  
Author(s):  
Alexander W. Dowling ◽  
Sree R. R. Vetukuri ◽  
Lorenz T. Biegler
Keyword(s):  
Pressure Swing Adsorption ◽  
Large Scale ◽  
Large Scale Optimization ◽  
Pressure Swing ◽  
Scale Optimization ◽  
Adsorption Cycle

High Altitude Observations at Sea

1951 ◽  
Vol 4 (02) ◽  
pp. 165-166
Author(s):  
A. N. Black
Keyword(s):  
High Altitude ◽  
Maximum Error ◽  
Sufficient Accuracy ◽  
Rate Of Change ◽  
Zenith Distance ◽  
The Sun ◽  
High Altitudes ◽  
Short Period ◽  
Very High

It is difficult to get satisfactory noon observations when the zenith distance is very small, because the Sun is rapidly changing in azimuth, the sextant must be swung through a wide arc of the horizon, and the Sun only dwells at the highest altitude for a very short period. To avoid these difficulties it is suggested that, instead of trying to measure the altitude of the Sun, one should measure its distance from a point on the horizon in a known azimuth. To make this measurement the Sun is brought down to the required point on the horizon, tilting the sextant as necessary; we shall distinguish this type of observation from the normal one, made with the sextant vertical, by calling the angle so obtained thehorizon distance. At normal altitudes this method, however sound in theory, breaks down because one cannot measure the azimuth with sufficient accuracy. However, at very high altitudes the rate of change of horizon distance with change of azimuth of the point from which the distance is measured becomes so small that it is not necessary to know the azimuth with such precision. In fact, at a zenith distance of 1°, the largest we shall consider here, the greatest error caused by an error of 1° in the azimuth is l″, and for smaller zenith distances the maximum error is proportionately less.

scholarly journals A strategy for oxygen conditioning at high altitude: comparison with air conditioning

2015 ◽  
Vol 119 (6) ◽  
pp. 719-723 ◽  
Author(s):  
John B. West
Keyword(s):  
Cognitive Impairment ◽  
High Altitude ◽  
Oxygen Concentration ◽  
Working Conditions ◽  
Air Conditioning ◽  
Large Scale ◽  
Oxygen Enrichment ◽  
Physical Working Capacity ◽  
Working Capacity ◽  
Large Numbers

Large numbers of people live or work at high altitude, and many visit to trek or ski. The inevitable hypoxia impairs physical working capacity, and at higher altitudes there is also cognitive impairment. Twenty years ago oxygen enrichment of room air was introduced to reduce the hypoxia, and this is now used in dormitories, hotels, mines, and telescopes. However, recent advances in technology now allow large amounts of oxygen to be obtained from air or cryogenic oxygen sources. As a result it is now feasible to oxygenate large buildings and even institutions such as hospitals. An analogy can be drawn between air conditioning that has improved the living and working conditions of millions of people who live in hot climates and oxygen conditioning that can do the same at high altitude. Oxygen conditioning is similar to air conditioning except that instead of cooling the air, the oxygen concentration is raised, thus reducing the equivalent altitude. Oxygen conditioning on a large scale could transform living and working conditions at high altitude, where it could be valuable in homes, hospitals, schools, dormitories, company headquarters, banks, and legislative settings.

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