Physiological responses to exercise at 47 and 66 ATA

1984 ◽  
Vol 57 (4) ◽  
pp. 1055-1068 ◽  
Author(s):  
J. V. Salzano ◽  
E. M. Camporesi ◽  
B. W. Stolp ◽  
R. E. Moon
Keyword(s):  
High Pressures ◽  
Physiological Condition ◽  
Physiological Responses ◽  
Gas Mixture ◽  
Arterial Lactate ◽  
Gas Density ◽  
Physiological Dead Space ◽  
Surface Measurements ◽  
Alveolar Hypoventilation ◽  
Maximum Work

Five male volunteers served as subjects for exercise studies during three dives to pressures of 47 and 66 ATA while breathing gases containing 0.5 ATA PO2 and varying amounts of N2 and He. The inspired gas density ranged from 1.1 g/l (BTPS) at the surface to 17.1 g/l at the highest pressure. Dyspnea at rest and during exercise was evident in all divers and was predominantly inspiratory in nature. Despite the dyspnea, divers were able to perform work requiring an O2 consumption larger than 2 l/min STPD at each depth. Compared with surface measurements, moderate work at depth was associated with alveolar hypoventilation, arterial hypercapnia, very large physiological dead space, and higher levels of arterial lactate and signs of simultaneous respiratory and metabolic acidosis. The increase of ventilation that accompanies the onset of acidemia at the surface was not present at depth. Acidemia at depth was more severe, and its onset occurred at lesser work rates than at 1 ATA. No large differences could be ascertained when a variety of responses obtained with inspired gas having a density of 7.9 g/l at 47 ATA were compared with those obtained with an inspired gas density of 17.1 g/l at 66 ATA. It appears that the major impact of the environment on the physiological responses to work was almost fully manifested at a pressure of 47 ATA with a He-O2 gas mixture. It is cautioned that maximum work tolerance may be an insufficient assessment of the physiological condition of a diver exposed to these high pressures.

Choice of adsorbate pressure in a gas mixture for specific surface measurements

1981 ◽  
Vol 20 (3) ◽  
pp. 204-206
Author(s):  
I. V. Uvarova ◽  
D. S. Arensburger ◽  
G. A. Bokan' ◽  
Z. A. Vasilevskaya ◽  
P. A. Vityaz'
Keyword(s):  
Specific Surface ◽  
Gas Mixture ◽  
Surface Measurements

INFLUENCE OF FOREIGN GASES AT HIGH PRESSURES ON THE SELECTIVE REFLECTION FROM MERCURY VAPOR

1957 ◽  
Vol 35 (1) ◽  
pp. 114-121 ◽  
Author(s):  
H. L. Welsh ◽  
J. A. Galt
Keyword(s):  
Classical Theory ◽  
High Pressures ◽  
Mercury Vapor ◽  
Selective Reflection ◽  
Frequency Shifts ◽  
Absorbing Medium ◽  
Gas Density ◽  
Reflection Data ◽  
Collision Broadening

The influence of the foreign gases hydrogen, helium, nitrogen, and argon on the selective reflection from mercury vapor at 2537 Å was studied at pressures up to 1500 atm. The results were interpreted on the basis of the classical theory of reflection from an absorbing medium. The damping constant was found to vary linearly with foreign gas density as predicted by collision broadening theory. Frequency shifts and collision diameters determined from selective reflection data agree fairly well with values measured in absorption by other workers.

scholarly journals Psycho-physiological responses of drivers to road section types and elapsed driving time on a freeway

2015 ◽  
Vol 42 (11) ◽  
pp. 881-888 ◽  
Author(s):  
Ju-Young Kim ◽  
Jin-Tae Kim ◽  
Wonchul Kim
Keyword(s):  
Physiological Condition ◽  
Physiological Responses ◽  
Eeg Signals ◽  
Road Section ◽  
Driving Time ◽  
Electroencephalogram Eeg

This paper addresses drivers’ psycho-physiological condition under the influence of various freeway section types and elapsed driving times. The authors analyzed the electroencephalogram (EEG) signals (α, β, and θ) of 51 drivers on a freeway in Korea. The findings show that the driver’s workload increases in tunnels and on left-curved sections, and that his or her concentration and response ability decrease after 60 min of elapsed driving time. The β/α ratios of EEG signals were found to be most effective in detecting differences in psycho-physiological responses. The results can help to promote safety on freeways by encouraging drivers to take rests every hour.

scholarly journals Implementation of Oxymetry Sensors for Cardiovascular Load Monitoring When Physical Exercise

2020 ◽  
Vol 8 (1) ◽  
pp. 178-199
Author(s):  
Dhodit Rengga Tisna ◽  
M. Udin Harun Al Rasyid ◽  
Sritrusta Sukaridhoto
Keyword(s):  
Heart Rate ◽  
Physical Exercise ◽  
Web Application ◽  
Physiological Condition ◽  
Physiological Responses ◽  
Measurement Data ◽  
Training Load ◽  
Physiological Data ◽  
Web Based ◽  
Load Monitoring

The performance condition of an athlete must always be maintained, one way to maintain that performance is by training. Each individual has different abilities and physiological responses in receiving the portion of the exercise. Physical exercise that exceeds the body's ability can worsen the condition of the athlete itself which can result in excessive fatigue (overtraining) or can even result in injury. Therefore a system is needed to monitor the condition of the physiological response when given the intensity of the training load so that the portion of the training provided provides positive benefits for the athlete. This system was developed using an oxymetry sensor, microcontroller and wifi module ESP8266.  This system is used to collect heart rate and oxygen saturation data, then with the existing formula the heart rate value is converted to a CVL (Cardiovascular Load) value to determine the level of fatigue in athletes when given the intensity of the training load. By using a web-based application, measurement data is displayed in realtime to make it easier to see the results of monitoring. From the experimental results the system can monitor changes in the physiological condition of the athlete when given the intensity of the training load. Finally, the developed system can collect athlete's physiological data, and can store the data in a database and display it in a web application.

Ir Fluorescence of XE2 Molecules in Beam-Excited Xe Gas and AR-XE Gas Mixture at High Pressures

2001 ◽  
pp. 85-90
Author(s):  
A. F. Borghesani ◽  
G. Bressi ◽  
G. Carugno ◽  
E. Conti ◽  
D. Iannuzzi
Keyword(s):  
High Pressures ◽  
Gas Mixture

Human respiration at rest in rapid compression and at high pressures and gas densities

1983 ◽  
Vol 54 (1) ◽  
pp. 290-303 ◽  
Author(s):  
R. Gelfand ◽  
C. J. Lambertsen ◽  
R. Strauss ◽  
J. M. Clark ◽  
C. D. Puglia
Keyword(s):  
Flow Resistance ◽  
Gas Flow ◽  
High Pressures ◽  
Ambient Pressure ◽  
Elimination Rate ◽  
Progressive Increase ◽  
Respiratory Drive ◽  
Gas Density ◽  
Human Respiration ◽  
End Tidal

Ventilation (V), end-tidal PCO2 (PACO2), and CO2 elimination rate were measured in men at rest breathing CO2-free gas over the pressure range 1–50 ATA and the gas density range 0.4–25 g/l, during slow and rapid compressions, at stable elevated ambient pressures and during slow decompressions in several phases of Predictive Studies III-1971 and Predictive Studies IV-1975. Inspired O2 was at or near natural O2 levels during compressions and at stable high pressures; it was 0.5 ATA during decompressions. Rapid compressions to high pressures did not impair respiratory homeostasis. Progressive increase in pulmonary gas flow resistance due to elevation of ambient pressure and inspired gas density to the He-O2 equivalent of 5,000 feet of seawater was not observed to progressively decrease resting V, or to progressively increase resting PACO2. Rather, a complex pattern of change in PACO2 was seen. As both ambient pressure and pulmonary gas flow resistance were progressively raised, PACO2 at first increased, went through a maximum, and then declined towards values near the 1 ATA level. It is suggested that this pattern of PACO2 change results from interaction on ventilation of 1) increase in pulmonary resistance due to elevation of gas density with 2) increase in respiratory drive postulated as due to generalized CNS excitation associated with exposure to high hydrostatic pressure. There may be a similar interaction between increased gas flow resistance and increase in respiratory drive related to nitrogen partial pressure and the narcosis resulting therefrom.

scholarly journals The effect of hydrogen on the physical properties of natural gas and the metrological characteristics of its metering systems

2020 ◽  
pp. 45-50
Author(s):  
A. A. Stetsenko ◽  
S. D. Nedzelsky ◽  
V. A. Naumenko
Keyword(s):  
Natural Gas ◽  
Physical Properties ◽  
High Pressures ◽  
Compressibility Factor ◽  
Metrological Characteristics ◽  
Physical Parameters ◽  
Gas Mixture ◽  
The Impact ◽  
Accuracy And Repeatability

Given the promise of the concept of using a mixture of hydrogen and natural gas as an energy source, studies were conducted in the following areas: determination of the effect of hydrogen impurities on the physical properties of natural gas; study of the effect of adding hydrogen to natural gas on the metrological characteristics of its consumption metering systems. To solve these problems, the following was carried out: determination of the dependence of the physical parameters of natural gas on the percentage of hydrogen in its composition: determination of the permissible fraction (permissible concentration) of hydrogen in natural gas in modern gas transmission and gas consuming systems. study of the effect of hydrogen additions on the metrological characteristics of measuring instruments and gas commercial metering systems. To conduct objective research and modeling, natural gas samples having different component composition were prepared. An analysis of the physical properties of these gases was carried out — their physical parameters were calculated: adiabatic index and sound velocity, density, compressibility factor, higher calorific value and Wobbe number. Based on these samples, modeling was performed — the physical parameters of the gases were calculated by adding hydrogen at different concentrations (from 2 to 23 %). Based on the research results, the following conclusions are made: When hydrogen is added to natural gas in an amount of from 2 to 10 %, the physical parameters of the resulting mixture change slightly (within acceptable limits), therefore, the addition of hydrogen to natural gas in an amount of up to 10 % allows the use of existing gas transmission and gas-consuming systems without any reconstructions, improvements, changes in algorithms for calculating the physical parameters of the gas mixture and calculating (volume) volumetric flow for commercial accounting. The impact on gas meters of consumers will be within the acceptable ranges of accuracy and repeatability and, therefore, will not require the cost of updating the meters. The addition of up to 25 % hydrogen by volume does not require a radical new technology of burners and gas transmission systems. Safety will not be compromised by adding 25 % hydrogen by volume to the natural gas network. Changes in the physical properties in the gas mixture have a number of disadvantages, but, in the aggregate, they do not pose any additional safety risk. The addition of hydrogen in a volume of more than 25 %, as well as the use of the mixture at high pressures, requires additional research and the development of new algorithms.

scholarly journals Schlieren Images of Negative Streamer and Leader Formations in CO2 and a CF3I-CO2 Electronegative Gas Mixture

2020 ◽  
Vol 10 (22) ◽  
pp. 8006
Author(s):  
Phillip Widger ◽  
Meirion Hills ◽  
Daniel Mitchard
Keyword(s):  
High Voltage ◽  
Energy System ◽  
Gas Mixtures ◽  
Electron Collision ◽  
Electrical Network ◽  
Lightning Strike ◽  
Gas Mixture ◽  
Electrical Networks ◽  
Gas Density ◽  
Sustainable Energy System

In electrical networks, SF6 gas is currently used to insulate high-voltage equipment, however, due to its high environmental impact, new alternatives such as CO2 and electronegative gas mixtures such as CF3I-CO2 are being trialled to replace SF6 and create a sustainable energy system. A high-voltage lightning impulse (1.2 μs/50 μs) was used to approximate the disturbance in a high-voltage electrical network caused by a lightning strike and helped to identify the likely streamer and leader formations in different gases insulating a piece of gas insulated switchgear. In this paper, the theoretical and practical aspects of electrical streamer and leader formations in pure CO2 and an electronegative gas mixture of CF3I-CO2 are examined using schlieren videography in small length rod-plane gas gaps between 20 and 50 mm in length. Schlieren allows the examination of gas density in streamer formations and for the differences in weakly attaching gases, such as CO2, and electronegative gas mixtures, such as CF3I-CO2, to be studied. The gas pressure is varied in order to examine the differences in streamer and leader formation as the gas density is varied and hence the probability of electron collision is varied.

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