Freshwater ecosystemFreshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands. They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and vegetation. There are three basic types of freshwater ecosystems: Lentic (slow moving water, including pools, ponds, and lakes), lotic (faster moving water, for example streams and rivers) and wetlands (areas where the soil is saturated or inundated for at least part of the time).
Montane ecosystemsMontane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial factor in shaping plant community, biodiversity, metabolic processes and ecosystem dynamics for montane ecosystems. Dense montane forests are common at moderate elevations, due to moderate temperatures and high rainfall.
HydraulicsHydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids.
Geography of EuropeEurope is traditionally defined as one of seven continents. Physiographically, it is the northwestern peninsula of the larger landmass known as Eurasia (or the larger Afro-Eurasia); Asia occupies the centre and east of this continuous landmass. Europe's eastern frontier is usually delineated by the Ural Mountains in Russia, which is the largest country by land area in the continent. The southeast boundary with Asia is not universally defined, but the modern definition is generally the Ural River or, less commonly, the Emba River.
Fossil fuel power stationsA fossil fuel power station is a thermal power station which burns a fossil fuel, such as coal or natural gas, to produce electricity. Fossil fuel power stations have machinery to convert the heat energy of combustion into mechanical energy, which then operates an electrical generator. The prime mover may be a steam turbine, a gas turbine or, in small plants, a reciprocating gas engine. All plants use the energy extracted from the expansion of a hot gas, either steam or combustion gases.
Topics in marine biologyMarine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy. A large proportion of all life on Earth lives in the ocean. The exact size of this large proportion is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world covering approximately 71% of the Earth's surface.
MeteorologyMeteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not begin until the 18th century. The 19th century saw modest progress in the field after weather observation networks were formed across broad regions. Prior attempts at prediction of weather depended on historical data.
AlloysAn alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity, and luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties.
DesertificationDesertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become arid. It is the spread of arid areas caused by a variety of factors, such as climate change and overexploitation of soil as a result of human activity. Throughout geological history, the development of deserts has occurred naturally. In recent times, the potential influences of human activity, improper land management, deforestation and climate change on desertification is the subject of many scientific investigations.
ArboricultureArboriculture (ˈɑrbərᵻˌkʌltʃər,_ɑrˈbɔr-) is the cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants. The science of arboriculture studies how these plants grow and respond to cultural practices and to their environment. The practice of arboriculture includes cultural techniques such as selection, planting, training, fertilization, pest and pathogen control, pruning, shaping, and removal. A person who practices or studies arboriculture can be termed an arborist or an arboriculturist.
