Steady stateIn systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties p of the system, the partial derivative with respect to time is zero and remains so: In discrete time, it means that the first difference of each property is zero and remains so: The concept of a steady state has relevance in many fields, in particular thermodynamics, economics, and engineering.
Side effectIn medicine, a side effect is an effect, whether therapeutic or adverse, that is unintended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug. Occasionally, drugs are prescribed or procedures are performed for their side effects; in that case, said side effect ceases to be a side effect and is now an intended effect.
PipelineA pipeline is a system of pipes for long-distance transportation of a liquid or gas, typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries around the world. The United States had 65%, Russia had 8%, and Canada had 3%, thus 76% of all pipeline were in these three countries. Pipeline and Gas Journal'''s worldwide survey figures indicate that of pipelines are planned and under construction.
FoulingFouling is the accumulation of unwanted material on solid surfaces. The fouling materials can consist of either living organisms (biofouling) or a non-living substance (inorganic or organic). Fouling is usually distinguished from other surface-growth phenomena in that it occurs on a surface of a component, system, or plant performing a defined and useful function and that the fouling process impedes or interferes with this function.
Lake KivuLake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, the western branch of the East African Rift. Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika. In the past, Lake Kivu drained toward the north, contributing to the White Nile. About 13,000 to 9,000 years ago, volcanic activity blocked Lake Kivu's outlet to the watershed of the Nile.
Climate of MarsThe climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be directly observed in detail from the Earth with help from a telescope. Although Mars is smaller than the Earth, 11% of Earth's mass, and 50% farther from the Sun than the Earth, its climate has important similarities, such as the presence of polar ice caps, seasonal changes and observable weather patterns. It has attracted sustained study from planetologists and climatologists.
SteelmakingSteelmaking is the process of producing steel from iron ore and/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon (the most important impurity) are removed from the sourced iron, and alloying elements such as manganese, nickel, chromium, carbon and vanadium are added to produce different grades of steel. Steelmaking has existed for millennia, but it was not commercialized on a massive scale until the mid-19th century. An ancient process of steelmaking was the crucible process.
Lake Albert (Africa)Lake Albert, originally known as Lake Mwitanzige and temporarily Lake Mobutu Sese Seko, is a lake located in Uganda and the Democratic Republic of the Congo. It is Africa's seventh-largest lake, as well as the second biggest of Uganda's Great Lakes. Lake Albert is located on the border between Uganda and the Democratic Republic of the Congo. It is the northernmost of the chain of lakes in the Albertine Rift, the western branch of the East African Rift. It is about long and wide, with a maximum depth of , and a surface elevation of above sea level.
