Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Air and the Atmosphere

Because of the weight of the column of gases above any point on the earth s surface, the atmosphere exerts pressure at every point on the earth s surface. This pressure, which is variously known as atmospheric, barometric, or air pressure, varies according to the altitude above sea level and the weather conditions (see Textbox 70). [Pg.406]

The gravitation of the earth attracts the gaseous components of the air, which exert a force, known as atmospheric pressure, on the surface of the pianet. The pressure on any particuiar piace on the earth s surface depends on the amount of air above the piace. it foiiows that the atmospheric pressure decreases at high aititudes, increases at iow aititudes and beiow sea ievei, and is aiso affected by changes in weather. Measuring the atmospheric pressure is usuaiiy done with physicai instruments known as barometers (see Fig. 83). [Pg.407]

Nitrogen. Nitrogen, a colorless, odorless, and tasteless gaseous element, is the main component of the atmosphere, which makes up about 78% of its volume since it is also an important constituent of living organisms. [Pg.408]

a gas that makes up just xmder 1% by volume of the atmosphere, is an inert element and a noble gas, that does not combine with other elements. [Pg.410]

Carbon Dioxide. Carbon dioxide, also a colorless and odorless gas, makes up about 0.03% of dry air. Carbon dioxide is introduced into the atmosphere by several natural processes it is released from volcanoes, from burning organic matter, and from living animals as a byproduct of the respiration process. It is for this latter reason that carbon dioxide plays a vital role in the carbon cycle (see Fig. 62), which makes possible one of the more important scientific tools in archaeology, radiocarbon dating (see Textbox 52). [Pg.410]


The planet shapes life, but life also shapes the planet (Nisbet, 2002). The maintenance of surface temperature is managed by the air hence, as fife controls the composition of the air and the atmospheric greenhouse, then life sets the surface temperature (Lovelock and Margulis, 1974 Lovelock, 1979, 1988). [Pg.3903]

In the history of mankind and the exploration of air and the atmosphere, the concept of climate has been subject to change, but also various descriptions have existed at the same time. It is beyond the scope of this book to address them here). Here, one can conclude that different definitions of climate are also in use. A priori, this is a contradiction, as there is only one climate system on earth. Obviously, this results from a pragmatic approach to the cognition and description of the climatic system by... [Pg.329]

In the hand lay-up technique the fibers are placed in a mold and the resin is later applied by rollers. One option is to cure using a vacuum bag. This removes the excess air and the atmospheric pressure exerts pressure to compact the part. The simplicity, low cost of tooling and flexibihty of design are the main advantages of this procedure. On the other hand, the long production time, intensive labor, and low automation potential are some of the disadvantages. [Pg.462]

The gas is prepared by fractionation of liquid air because the atmosphere contains 0.94% argon. The atmosphere of Mars contains 1.6% of 40Ar and 5 p.p.m. of 36Ar. [Pg.43]

Air Monitoring. The atmosphere in work areas is monitored for worker safety. Volatile amines and related compounds can be detected at low concentrations in the air by a number of methods. Suitable methods include chemical, chromatographic, and spectroscopic techniques. For example, the NIOSH Manual of Analytical Methods has methods based on gas chromatography which are suitable for common aromatic and aHphatic amines as well as ethanolamines (67). Aromatic amines which diazotize readily can also be detected photometrically using a treated paper which changes color (68). Other methods based on infrared spectroscopy (69) and mass spectroscopy (70) have also been reported. [Pg.264]

Example 8 Compressible Flow with Friction Losses Calculate the discharge rate of air to the atmosphere from a reservoir at 10 Pa gauge and 20 G through 10 m of straight 2-in Schedule 40 steel pipe (inside diameter = 0.0525 m), and 3 standard radius, flanged 90 elhows. Assume 0.5 velocity heads lost for the elhows. [Pg.651]

If the temperature structure, instead of being that of Fig. 17-6, differs primarily in the lower layers, it resembles Fig. 17-7, where a temperature inversion (an increase rather than a decrease of temperature with height) exists. In the forced ascent of the air parcel up the slope, dry adiabatic cooling produces parcel temperatures that are everywhere cooler than the environment acceration is downward, resisting displacement and the atmosphere is stable. [Pg.254]

For any pollutant, air quality criteria may refer to different types of effects. For example. Tables 22-1 through 22-6 list effects on humans, animals, vegetation, materials, and the atmosphere caused by various exposures to sulfur dioxide, particulate matter, nitrogen dioxide, carbon monoxide, ozone, and lead. These data are from fhe Air Quality Criteria for these pollutants published by the U.S. Environmental Protection Agency. [Pg.367]

A man was asked to clean a 45-m tank that had contained toluene. It was 20 ft (6 m) tall and 10 ft (3 m) diameter. It had not been gas-freed, and the atmosphere had apparently not been tested. He entered the tank through the 16-in.-diameter top opening, using a rope for descent. Self-contained breathing apparatus was available on the job, but he did not wear it. He was overcome by tbe vapor and lack of air and collapsed on the floor of the tank. [Pg.242]

The majority of larger industrial burners, including furnace and boiler applications, are of the forced-draft type. These employ a combustion air fan to provide all the air needed for complete combustion. The burners are usually sealed into the combustion chamber so that there is no access to secondary air from the atmosphere as with natural-draft burners. Forced-draft burners may be of the premix type, where air and gas are mixed prior to the burner, or, more commonly, of the nozzle mix type, where the mixing takes place within the burner. [Pg.263]

Lees and Whitehead" have shown that differences in boiler design lead to differences in furnace atmospheres, which are subsequently reflected in differences in scale morphology and corrosion performance. Hence they report that there is no unique scale morphology which is characteristic of furnace wall corrosion. They also warn that the scale that is examined during an investigation may not be an exact reflection of the scale on the tube surfaces during operation due to the possible hydrolysis of the scale on cooling (when hot flue gas is replaced by moist air) and the redistribution of phases in the scale due to the loss of the incident heat flux. [Pg.988]

The carbon dioxide generated by the personnel in the artificial atmosphere of submarines and spacecraft must be removed from the air and the oxygen recovered. Submarine design teams have investigated the use of potassium superoxide, K02, as an air purifier because this compound reacts with carbon dioxide and releases oxygen (Fig. 4.16) ... [Pg.275]

Radiation-induced cross-linking of chlorinated and chlorosulfonated high-density PE has been reported by Korolev et al. [262]. It has been observed that the extent of cross-linking is strongly dependent on the chlorine content in the sample, chlorosulfonated PE is cross-linked more readily than the chlorinated sample in air and inert atmosphere. [Pg.876]


See other pages where Air and the Atmosphere is mentioned: [Pg.431]    [Pg.406]    [Pg.407]    [Pg.409]    [Pg.80]    [Pg.315]    [Pg.80]    [Pg.48]    [Pg.110]    [Pg.44]    [Pg.431]    [Pg.406]    [Pg.407]    [Pg.409]    [Pg.80]    [Pg.315]    [Pg.80]    [Pg.48]    [Pg.110]    [Pg.44]    [Pg.922]    [Pg.405]    [Pg.135]    [Pg.135]    [Pg.99]    [Pg.341]    [Pg.426]    [Pg.1092]    [Pg.2183]    [Pg.268]    [Pg.68]    [Pg.254]    [Pg.321]    [Pg.218]    [Pg.844]    [Pg.657]    [Pg.946]    [Pg.123]    [Pg.285]    [Pg.263]    [Pg.602]    [Pg.78]    [Pg.165]    [Pg.286]    [Pg.872]   


SEARCH



Atmospheric air

Atmospherical Air

Pollution of the Atmosphere and Air Quality

The air

© 2024 chempedia.info