Atmosphere composition. Covers

The data in Fig. 7.1 cover the period during which reliable analytical techniques have been in use. In order to extend the record further into the past, resort is made to measurements obtained using cruder techniques (by modern-day standards) in the latter part of the f 9th century and the first half of the 20th century. These early data are shown in Fig. 7.2, together with the most complete recent dataset, which is from Mauna Loa. A more reliable way of extending the record backwards has been through the extraction and analysis of bubbles of air trapped in ice cores collected from the polar ice-caps. The principle of this method is that the trapped air bubbles record the atmospheric composition at the time the ice formed. By dating the various layers in the cores from which the air bubbles have... 

The characteristics of the changes in several species discussed in this chapter are shown in Fig. 19-3. This figure depicts the changing composition of the atmosphere on three time scales. Figures 19-3a-c show the simultaneous variation of CO2, CH4, temperature, and SO from the Vostok ice core (see also Fig. 1-2). These records also clearly demonstrate that the Earth functions as a coupled system. Temperature, CO2 and CH4 are positively correlated with one another, but each is negatively correlated with (for reasons that are not yet known). This time period covers 160000 years including the... 

The special position of the Earth among the terrestrial planets is also shown by the availability of free water. On Venus and Mars, it has not until now been possible to detect any free water there is, however, geological and atmospheric evidence that both planets were either partially or completely covered with water during their formation phase. This can be deduced from certain characteristics of their surfaces and from the composition of their atmospheres. The ratio of deuterium to hydrogen (D/H) is particularly important here both Mars and Venus have a higher D/H ratio than that of the Earth. For Mars, the enrichment factor is around 5, and in the case of Venus, 100 (deBergh, 1993). 

The hugely complicated chemistry of the catalytic converter is described in some depth in the Open University s excellent book Physical Chemistry Principles of Chemical Change, Topic study 2 . Its part 1 is entitled the three-way catalytic converter , Open University, Milton Keynes, 1996. It covers the composition of the catalytic surface and the role of each dopant, the actual chemical reactions occurring, and details of the current legal situation regarding atmospheric pollution. 

In the field of metallic powder applications, a method of plasma spray coating suitable for biomedical materials has been developed using titanium and calcium phosphate composite powder. By means of the mechanical shock process, the appropriate composite powder was prepared, and plasma sprayed on Ti substrate under a low-pressure argon atmosphere. A porous Ti coating layer was obtained in which the surface and the inside of the pores were covered thinly with hydroxyapatite. This surface coating is expected to show excellent bone ingrowth and fixation with bone (21). 

Many of these questions are not purely academic. For example, it is well known that ice bubbles trapped in ice sheets such as the one covering Greenland and Antarctica can be used to reconstruct the composition of earth s atmosphere over the past 750,000 years... 

Meteorio iron.—-Large masses of metallio iron have been discovered from time to time, in different parts of the globe, embedded in the soil and also lying upon the surface others of a similar kind have been known to fell from the atmosphere, and ore hence termed meteorites. These masses are generally covered over with a kind of hlack enamel, which protects tho metal from the action of tho atmosphere. The iron forms usually a sort of network round a crystallized metallic mineral of a complicated composition. These meteoric masses are sometimes so large, and the metal which they contain so pure, as to furnish the inhabitants of the ncighborhoed with ample material for knives and spearheads. When examined chemically, there seems... 

The composition of our atmosphere is complex and varies with altitude. It also varies with time following both short- and long-term variations, from the daily cycles, to processes which cover many years. We are concerned here... 

In more exposed environments, copper roofs and pipes quickly become covered in verdigris. Verdigris is green in colour (Figure 10.26) and is composed of copper salts formed on copper. The composition of verdigris varies depending on the atmospheric conditions, but includes mixed copper(n) carbonate and copper(n) hydroxide (CuC03.Cu(0H)2). 

Jupiter and Uranus are outer planets composed mainly of gases. Jupiter s atmosphere contains reddish-brown clouds of ammonia. Uranus has an atmosphere made up mainly of hydrogen and helium with clouds of water vapor. This combination looks greenish to an outside observer. In addition, Mars has an atmosphere that is 95% carbon dioxide, and Venus has a permanent cloud cover of sulfur dioxide that appears pale yellow to an observer. Mercury has no permanent atmosphere. Saturn has 1 km thick dust and ice rings that orbit the planet. The eight planets in our solar system are diverse, each having different chemical compositions within and surrounding the planets. Out Earth is by far the friendliest planet for human existence. 

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