03.08.2009

Aerosols are tiny particles suspended in the air. Some occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray. Human activities, such as the burning of fossil fuels and the alteration of natural surface cover, also generate aerosols. Averaged over the globe, aerosols made by human activities currently account for about 10 percent of the total amount of aerosols in our atmosphere. Aerosols tend to cause cooling of the Earth’s surface immediately below them. Because most aerosols reflect sunlight back into space, they have a “direct” cooling effect by reducing the amount of solar radiation that reaches the surface. The magnitude of this cooling effect depends on the size and composition of the aerosol particles, as well as the reflective properties of the underlying surface. It is thought that aerosol cooling may partially offset expected global warming that is attributed to increases in the amount of carbon dioxide from human activity. Aerosols are also believed to have an “indirect” effect on climate by changing properties of clouds. Indeed, if there were no aerosols in the atmosphere, there would be no clouds. It is very difficult to form clouds without small aerosol particles acting as “seeds” to start the formation of cloud droplets. As aerosol concentration increases within a cloud, the water in the cloud gets spread over many more particles, each of which is correspondingly smaller. Smaller particles fall more slowly in the atmosphere and decrease the amount of rainfall. In this way, changing aerosols in the atmosphere can change the frequency of cloud occurrence, cloud thickness, and rainfall amounts

The gas obtained when coal is heated in an airtight place. It consists mainly of hydrogen and methane. Coke oven gas is burned to produce heat in industrial plants and in homes. It was formerly used for illumination. Coke oven gas is made by heating coal in a by-product coke oven that heats to about 2000 °F (1100 °C). As the coal heats, coke oven gas and other by-products are given off. The gas leaves the oven through pipes and is stored in large tanks called gas holders

Process of bituminizing; namely to convert into bitumen

When coal stocks rise too much in the US, due to reduced exports and lower local electricity generation, coal storage space diminishes, putting pressure on coal prices, which in turn lowers the ceiling for coal-to-gas substitution. In order to stabilize this ceiling to natural gas prices, coal producers will likely have to increase the amount of coal shut-ins. The alternative to additional coal shut-ins to rebalance the coal market would be further coal stock building by utilities

The conversion of organic materials, such as plant or animal waste, into usable products or energy sources by biological processes or agents, such as certain microorganisms

The Baltic Dry Index is a daily average of prices to ship raw materials. It represents the cost paid by an end customer to have a shipping company transport raw materials across seas on the Baltic Exchange, the global marketplace for brokering shipping contracts. The Baltic Exchange is similar to the New York Merc in that it is a medium for buyers and sellers of contracts and forward agreements (futures) for delivery of dry bulk cargo. The Baltic is owned and operated by the member buyers and sellers. The exchange maintains prices on several routes for different cargoes and then publishes its own index, the BDI, as a summary of the entire dry bulk shipping market. This index can be used as an overall economic indicator as it shows where end prices are heading for items that use the raw materials that are shipped in dry bulk. The BDI is one of the purest leading indicators of economic activity.

The ratio of the luminous or radiant flux absorbed by a body to the flux falling on it. Absorptance is generally represented by the Greek letter ? (alpha). By definition, in the case of a blackbody ? = 1.