Percent relative saturation

Note that the percent saturation is always less than the percent relative saturation. 

The air concentration, Cg, the seawater concentration, Ci, and the Henry s constant H (2) can be used to calculate the percent relative saturation S of a compound in the ocean with the equation... 

Table VIII. Percent Relative Saturation of Trace Gases in Seavs ater...

Note Percent relative saturation was calculated as [(Q///Cg) undersaturation. The symbols are as in Table VII. 

Percent absolute saturation is always less than relative saturation except at saturated conditions (or at zero percent saturation) when percent absolute saturation = percent relative saturation. 

Helium contains 12% by volume of ethyl acetate. Calculate (a) the percent relative saturation and (b) the percent absolute saturation of the mixture at a temperature of 30°C and a pressure of 98 kPa. 

Relative saluration. Relatiiie saturation, also called r ladmJitmudiiyi expressed as a percentage is defined as lOOp // , where is the vapor pressure at the dry-bulb temperature of the mixture. For any vapor, the graphical representation of conditions of constant relative saturation can easily be constructed on a vapor-pressure-temperature chart, as in Fig. lAa, by dividing the ordinates of the vapor-pressure curve into appropriate intervals. Thus the curve for 50 percent relative saturation shows a vapor partial pressure equal to one-half the equilibrium vapor pressure at any temperature. A reference-substance plot, such as Fig, 7.2, could also be used for this. 

The percent saturation should be distinguished from the percent relative saturation, which is defined as the partial pressure of the condensable component present divided by the partial pressure present at the saturation condition. Thus,... 

Percent saturation is the ratio of the partial pressure of a condensable vapor ia a gas to the vapor pressure of the Hquid at the same temperature, expressed as a percentage. For water vapor ia air this is called percent relative humidity. 

Model is relatively insensitive to BODyu load variations. A doubling of loads (from each point source) results in deviations of 5-9 percent DO saturation from the standard profile. 

The moistnre content or hnmidity of air has an important effect on the properties of the gaseons mixtnre. Steam in air at any relative hnmidity less than 100 percent mnst exist in a superheated condition. The satnration temperatnre corresponding to the actual partial pressure of the steam in air is called the dew point. This term arose from the fact that when air at less than 100 percent relative hnmidity is cooled to the temperatnre at which it becomes satnrated, the air has reached the minimnm temperatnre to which it can be cooled withont precipitation of the moistnre (dew). Dew point can also be defined as that temperatnre at which the weight of steam associated with a certain weight of dry air is adeqnate to saturate that weight of air. 

Percent relative humidity is the best known ami perhaps the most widely used method for expressing the water vapor content of air. Percent relative humidity is defined as the ratio of the prevailing water vapor pressure c . to the water vapor pressure if the air were saturated, t, multiplied by 100 ... 

The solubility of magnesium sulfite hexahydrate in water with the addition of magnesium sulfate was accurately predicted by the LCM for 0-6 molal (29). The relative saturation of the magnesium sulfite hexhydrate was predicted within 10 percent error at 40 and 50 C, and within 20 percent error at 60 C. 

Soil CEC is composed of two types of constituents (1) weak Lewis acid metals, commonly referred to as bases (e.g., Ca2+, Mg2+, K+, and Na+) and (2) relatively strong Lewis acid metals, H+, and heavy metals, depending on the nature of the sample, for example, geologic waste or natural soil (Al3+, H+, Fe2+, Fe3+, and Mn2+). The term percent base saturation is commonly used to describe the percent of the sum of exchangeable bases relative to the CEC near pH 7 or at pH 7 (CEC ). The equation for percent base saturation is given as... 

Figure 11,5, Relationships between relative saturated hydraulic conductivity and percent dispersion index of two Kentucky soils (dispersion index = percent of total clay remaining waterborne after 1 hr of settling in an Imhoff cone) (from Marsi and Evangelou, 1991c, with...

The dispersion phenomenon in the two humid soils (Pembroke and Uniontown) was evaluated through the use of an Imhoff cone test and a permeameter. The Imhoff cone is commonly used by engineers to determine settleable solids (see Chapter 9). The results of clay dispersion obtained by the Imhoff cone test are expressed as a dispersion index (percent of total clays in the soil sample dispersed), which is correlated with relative saturated hydraulic conductivity. This is shown in Figure 11.5. It demonstrates that each of the soils, depending on its clay content (Pembroke 59% Uniontown 20%), exhibits unique saturated hydraulic conductivity behavior with respect to the dispersion index. Also, in each of the soils, various mechanisms (different line slopes) appear to control saturated hydraulic conductivity. 

Atmospheric air can be viewed as a mixture of dry air and water vapor, and the atmospheric pressure is the sum of the pressure of dry air and the pressure of water vapor, which is called the vapor pressure P . Air can hold a certain amount of moisture only, and the ratio of the actual amount of moisture in the air at a given temperature to the maximum amount air can hold at that temperature is called the relative humidity (f>. The relative humidity ranges from 0 for dry air to 100 percent for saturated air (air that cannot hold any more moisture). The partial pressure of water vapor in saturated air is called the saturation pressure Table 14 9 lists the saturation pressure at various teraperaturest... 

A glass of milk left on lop of a counter in the kitchen at 5°C. 88 kPa, and 50 percent relative humidity is lightly sealed by a sheet of 0.009-mm-thick aluminum foil whose permeance is 2.9 X 10" - kg/s m Pa. llte inner diameter of the glass is 12 cm. Assuming the air in (he glass to be saturated at all limes, determine how much ilie level of the milk in the glass will recede in 12 h. Answer 0.00011 mm... 

A gas leaves a solvent recovery system saturated with benzene at 50°C and 750 mm Hg. The gas analyzes, on a benzene-free basis, 15% CO, 4% O2, and the remainder nitrogen. This mixture is compressed to 3 atm and is subsequently cooled to 20°C. Calculate the percent benzene condensed in the process. What is the relative saturation of the final gas ... 

From Sonntag equation (12-4),p, = 19,948 Pa difference from Antoine is less than 0.5 percent. Relative humidity = 100 x 3915/19,948= 19.6 percent. From a psychrometric chart, e.g.. Fig. 12-1, a humidity of 0.025 kg/kg at T = 60°C lies very close to the adiabatic saturation line for 35°C. Hence a good first estimate for Tas and T b will be 35°C. Refining the estimate of Twb by using the psychrometer equation and iterating gives... 

Often this quantity is multiplied by 100 to give the percent relative humidity. Suppose the percent relative humidity is 80.0% at91.4°F (33.0°C) in a house with volume 245 m. Then an air conditioner is mrned on. Due to the condensation of water vapor on the cold coils of the air conditioner, water vapor is also removed from the air as it cools. After the air temperature has reached 77.0°F (25.0°C), the percent relative humidity is measured to be 15.0%. (a) What mass of water has been removed from the air in the house Reminder Take into account the difference in saturated water vapor pressure at the two temperamres.) (b) What volume would this liquid water occupy at 25°C (Density of hquid water at 25.0°C = 0.997 g/cmL)... 

Eighty percent relative humidity was achieved in each case by providing a saturated ammonium chloride solution in each of the test chambers. 

The Kelvin equation can be combined with the relative humidity, RH, if water is involved as the fluid relative humidity indicates how moist the air is. The amount of water vapor in the air at any given time is usually less than that required to saturate the air. The relative humidity is the percentage of saturation humidity, generally calculated in relation to the saturated vapor density. Relative humidity may be defined as the ratio of the water vapor density (mass per unit volume) to the saturation water vapor density, usually expressed in percent. Relative humidity is also approximately equal (exactly equal when water is assumed as an ideal gas) to the ratio of the actual water vapor pressure to the saturation water vapor pressure, RH = PJP°. The P° values corresponding to each temperature are given in tables which can be found in handbooks. If RH is measured in an experiment, then Pv can be calculated by using the saturation water vapor pressure tables and can be inserted into the Kelvin equation. 

TEMPERATURE, DEWPOINT - The temperature at which the condensation of water vapor in a space begins for a given state of humidity and pressure as the temperature of the vapor is reduced. The temperature corresponding to saturation (100 percent relative humidity) for a given absolute humidity at constant pressure. 

A quantitative description of the mass of water per unit mass of dry solid is provided by plotting it against a quantity called percent relative humidity. To understand this quantity, consider air in equilibrium with liquid water. The partial pressure of water vapor in the air, in equilibrium with liquid water at any temperature, is the vapor pressure of water, The saturation humidity is... 

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