Atmospheres absolute

Example. A gas oil having a density of 0.84 grams per milliliter (37°AP1) is stored at 60°C (140°F) under a gas blanket of carbon dioxide (CO2) at a pressure of 1 atmosphere absolute. To estimate the amount of carbon dioxide dissolved in the gas oil at equilibrium, take the following steps ... 

Step 4. A straight line between the point on the reference line 2 and the point on the pressure line for 1 atmosphere absolute will cross the line for gas dissolved at 1,500 parts per million by weight. 

The atmospheric reduced crude is the feedstock for the vacuum distillation unit. To prevent thermal decomposition (cracking) of the higher boiling point hydrocarbons in the crude oil, the pressure in the vacuum distillation fractionation column is reduced to about one-twentieth of an atmosphere absolute (one atmosphere pressure is 14.7 psia or 760 mm Fig). This effectively reduces the boiling points of the hydrocarbons several hundred degrees Fahrenheit. The components boiling below about 1050°F (565°C) are vaporized and removed as vacuum gas... 

FIGUREl.il NO concentration (top) and 02 concentration (bottom) as a function of 02 pressure. As can be seen, NO and 02 concentrations increase significantly when a rat is exposed to pressurized 02 atmospheres (2.8 atmospheres absolute, ATA). (Reprinted with permission from the American Physiological Society [127].)... 

Hyperbaric pressure may intensify odors or render odoriferous some odorless gases such as methane. Professional divers, experimentally exposed to hyperbaric pressures, detected odors of krypton and methane when sniffing these during the decompression phase of a dive. The threshold for krypton was 2 ATA (atmosphere absolute), and 100% positive responses occurred at 6 ATA. For methane, the threshold was 3 ATA (100% 13 ATA). The thresholds of individuals differed by as much as a factor of three (Laffort and Gortan, 1987). 

The torr is included in the table only to facilitate the transition from this familiar unit to the statutory units N m, mbar and bar. In future the pressure units tor, mm water column, mm mercury column (mm Hg), % vacuum, technical atmosphere (at), physicalatmosphene (atm), atmosphere absolute (ata), pressure above atmospheric and pressure below atmospheric may no longer be used. Reference is made to DIN 1314 in this context. 2) The unit Newton divided by square meters (N m ) is also designated as Pascal (Pa) 1 N m = 1 Pa. Newton divided by square meters or Pascal is the SI unit for the pressure of fluids. 3) 1 torr = 4/3 mbar fl torr = 1 mbar. ... 

Cryogenic Liquid A cryogenic liquid is a refrigerated liquefied gas having a boiling point colder than -130 °F at one atmosphere, absolute. A material that meets this definition is subject to the same requirements tor compressed gases widrout regard to whether it meets the standard definition of a compressed gas. 

EXAMPLE 6-9 Calculate the viscosity of the gas mixture given below at 200°F and a pressure of one atmosphere absolute. 

List the standard conditions used in your state. List the standard conditions used in this book. Convert a pressure of 10 atmospheres (absolute) to psia. 

B29. Bloor, K., Bratten, N. T., Jacobson, I., McCaffrey, J. F., and McDowall, D. G., Low flow perfusion with total heart-lung bypass at 2 atmospheres absolute pressure. In Clinical Application of Hyperbaric Oxygen (I. Boerema, W. H. Brummelkamp, and N. G. Meijne, eds.), pp. 194-196. Elsevier, Amsterdam, 1964. 

Smith, G., and Lawson, D. D., The protective effect of inhalation of oxygen at two atmospheres absolute pressure in acute coronary arterial occlusion. Surg. Gynecol. Obstet. 144, 320-322 (1962). 

Figure 23.1 is a psychrometric chart for the air-water system. It shows the relationship between the temperature (abscissa) and absolute humidity (ordinale, in g water per kg dry air) of humid air from 0°C to 130°C at one atmosphere absolute pressure. Line as representing percent humidity and adiabatic saturation are drawn according to the thermodynamic definitions of these terms. Equations for the adiabatic saturation and wet-bulb temperature lines on the chart are as follows (Geankoplis 1983) ... 

Nominal burning rates, sec /inch pressure, atmospheres, absolute 0.13 0.40 1.0 19.0 36... 

Water vapor in the atmosphere. Absolute humidity is the amount of water vapor in a given quantity of air it is not a function of temperature. Relative humidity is a ratio of actual atmospheric moisture to the maximum amount of moisture that could be carried at a given temperature, assuming constant atmospheric pressure. 

High pressure Breathing 100 percent oxygen at pressures greater than 3 ATA (atmospheres absolute) may result in acute toxicity, producing convulsions. 

Third, the distinction between gauge pressure and absolute pressure is not always made, or made clearly. A reading of zero pressure on a gauge means 760 Torr (corrected for standard conditions), or one atmosphere absolute pressure. 

Water/Dew Point is expressed in ppm (volume/volume) and degrees F at one atmosphere absolute, 14.696 psia (101.325 kPa, abs 760 mm Hg). The Moisture Conversion Table can be used to convert the moisture content (water content) in any gas from ppm (v/v) to mg/L or vice versa. 

At temperatures below 100 °C the relative humidity is a convenient measure to use. At higher temperatures the use of RH can, however, be rather confusing. The relative humidity at different partial pressures of water at temperatures ranging from 120 to 220 °C is given in Fig. 6.14. At atmospheric absolute pressure, the partial pressure of water in kPa roughly equals the water content in mole or volume percent. It can be seen that the relative humidity at a particular partial pressure of water decreases dramatically with increasing temperature. For example, at 120 and 220 °C the pure steam atmosphere ( FhjO =101 kPa) corresponds to a relative humidity of 51 % and 4.4 %, respectively. 

Pressure P. Pressure is measured in pounds per square inch at the entrance valve to the gas chromatograph [psi = pounds per square inch = Ib/in. psia = pounds per square inch absolute = ata (atmosphere absolute) psig = pounds per square inch gauged, 1 psi = 0.069 bar]. 

All patients received 90 minute HBO sessions at 2.0 or 2.5 ata (atmospheres absolute) for 19 to 36 sessions (mean of 28 6). Five of the patients were diabetic. One eye was pseudophakic. Twenty-six patients were followed prospectively in Devon. Patients were examined pre-, mid-, and post-HBO which were at approximately one month intervals, and thereafter at 3 months after conclusion of therapy. 

W.H. Brummelkamp, Considerations on hyperbaric oxygen therapy at three atmospheres absolute... 

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