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California Current
The California Current is a Pacific Ocean current that moves southward along the western coast of North America, beginning off southern British Columbia and ending off southern Baja California Sur. It is considered an Eastern boundary current due to the influence of the North American coastline on its course. It is also one of five major coastal currents affiliated with strong upwelling zones, the others being the Humboldt Current, the Canary Current, the Benguela Current, and the Somali Current. The California Current is part of the North Pacific Gyre, a large swirling current that occupies the northern basin of the Pacific.
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  • 08 Nov 2022
Topic Review
Paedotherium
Paedotherium is an extinct, potentially paraphyletic genus of Notoungulate, belonging to the family Hegetotheriidae, composed of small-sized, rodent or lagomorph-like South American ungulates. Four species are unambiguously recognized, from the Late Miocene to the Pleistocene of Argentina , and from the late Miocene of Bolivia and Chile .
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Topic Review
List of Aviation, Aerospace and Aeronautical Abbreviations
This is a list of aviation, aerospace, aeronautical and avionics abbreviations.
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Topic Review
Life Cycle Assessment of State-of-the-Art Steel Production Routes
Using the life cycle assessment (LCA) methodology, the impacts of the primary steel production via the blast furnace route and the scrap-based secondary steel production via the electric arc furance (EAF) route are assessed. Methodological as well as technical differences are analysed and their impacts on the results.
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  • 08 Nov 2022
Topic Review
Photocathode Materials
Photoelectrochemical water splitting is a promising approach to sustainable hydrogen production with no carbon emissions. Hydrogen being a future fuel to coming human generations is of utmost importance. The photocathodes in a photoelectrochemical (PEC) water-splitting cell are essential for the direct evolution of hydrogen. Among the known photocathodes, Cu-based p-type semiconducting materials are the most promising photo-absorber materials owing to their low-cost, low toxicity, natural abundance, suitable band-gaps, and favorable band edges for reduction. 
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  • 08 Nov 2022
Topic Review
Tollmann's Hypothetical Bolide
Alexander Tollmann's bolide, proposed by Kristan-Tollmann and Tollmann in 1994, is a hypothesis presented by Austrian geologist Alexander Tollmann, suggesting that one or several bolides (asteroids or comets) struck the Earth at 7640 BCE (±200), with a much smaller one at 3150 BCE (±200). If true, this hypothesis explains early Holocene extinctions and possibly legends of the Universal Deluge. The claimed evidence for the event includes stratigraphic studies of tektites, dendrochronology, and ice cores (from Camp Century, Greenland) containing hydrochloric acid and sulfuric acid (indicating an energetic ocean strike) as well as nitric acids (caused by extreme heating of air). Christopher Knight and Robert Lomas in their book, Uriel's Machine, argue that the 7640 BCE evidence is consistent with the dates of formation of a number of extant salt flats and lakes in dry areas of North America and Asia. They argue that these lakes are the result remains of multiple-kilometer-high waves that penetrated deeply into continents as the result of oceanic strikes that they proposed occurred.
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Topic Review
Core-Mantle Differentiation
Core-mantle differentiation is the set of processes that took place during the accretion stage of Earth's evolution (or more generally, of rocky planets) that results in the separation of iron-rich materials that eventually would conform a metal core, surrounded by a rocky mantle. According to the Safronov's model, protoplanets formed as the result of collisions of smaller bodies (planetesimals), which previously condensed from solid debris present in the original nebula. Planetesimals contained iron and silicates either already differentiated or mixed together. Either way, after impacting the Proto-Earth their materials very likely became homogenized. At this stage, the Proto-Earth was probably the size of Mars. Next followed the separation and stratification of the Proto-Earth's constituents, chiefly driven by their density contrasts. Factors such as pressure, temperature, and impact bodies in the primordial magma ocean have been involved in the differentiation process. The differentiation process is driven by the higher density of iron compared to silicate rocks, but the lower melting point of the former constitutes an important factor. In fact, once iron has melted, differentiation can take place whether silicate rocks are completely melted or not. On the premises of these plausible scenarios, several models have been proposed to account for the core-mantle differentiation following the stage of nebular formation of the solar system. They can be summarized into three mechanisms: 1) Percolation of iron alloy through silicate crystals; 2) Separation of metal from rock in a primordial magma ocean; 3) Migration of iron diapirs or dikes through the mantle.
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Topic Review
Cappadocia (Roman Province)
Template:Infobox Former Subdivision Cappadocia was a province of the Roman Empire in Anatolia (modern central-eastern Turkey), with its capital at Caesarea. It was established in 17 AD by the Emperor Tiberius (ruled 14-37 AD), following the death of Cappadocia's last king, Archelaus. Cappadocia was an imperial province, meaning that its governor (legatus Augusti) was directly appointed by the emperor. During the latter 1st century, the province also incorporated the regions of Pontus and Armenia Minor.
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Topic Review
Temperate Climate
In geography, the temperate or tepid climates of Earth occur in the middle latitudes, which span between the tropics and the polar regions of Earth. In most climate classifications, temperate climates refer to the climate zone between 35 and 50 north and south latitudes (between the subarctic and subtropical climates). These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small. They typically feature four distinct seasons, Summer the warmest, Autumn the transitioning season to Winter, the colder season, and Spring the transitioning season from winter back into summer. In the northern hemisphere, the year starts with winter, transitions in the first half year through spring into summer, which is in mid-year, then at the second half year through autumn into winter at year-end. In the southern hemisphere, the seasons are swapped, with summer between years and winter in mid-year. The temperate zones (latitudes from 23.5° to the polar circles at about 66.5°, north and south) are where the widest seasonal changes occur, with most climates found in it having some influence from both the tropics and the poles. The subtropics (latitudes from about 23.5° to 35°, north and south) have temperate climates that have the least seasonal change and the warmest in winter, while at the other end, Boreal climates located from 55 to 65 north latitude have the most seasonal changes and long and severe winters. In temperate climates, not only do latitudinal positions influence temperature changes, but sea currents, prevailing wind direction, continentality (how large a landmass is), and altitude also shape temperate climates. The Köppen climate classification defines a climate as "temperate" when the mean temperature is above −3 °C (26.6 °F) but below 18 °C (64.4 °F) in the coldest month. However, other climate classifications set the minimum at 0 °C (32.0 °F).
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  • 08 Nov 2022
Topic Review
Zagros Fold and Thrust Belt
The Zagros fold and thrust belt (Zagros FTB) is an approximately 1,800-kilometre (1,100 mi) long zone of deformed crustal rocks, formed in the foreland of the collision between the Arabian Plate and the Eurasian Plate. It is host to one of the world's largest petroleum provinces, containing about 49% of the established hydrocarbon reserves in fold and thrust belts and about 7% of all reserves globally.
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