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Electricity Market
In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had undergone enormous changes for reasons ranging from the technological advances on supply and demand sides to politics and ideology. A restructuring of electric power industry at the turn of the 21st century involved replacing the vertically integrated and tightly regulated "traditional" electricity market with multiple competitive markets for electricity generation, transmission, distribution, and retailing. The traditional and competitive market approaches loosely correspond to two visions of industry: the deregulation was transforming electricity from a public service (like sewerage) into a tradable good (like crude oil). As of 2020s, the traditional markets are still common in some regions, including large parts of the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Niugini
Air Niugini Limited is the national airline of Papua New Guinea, based in Air Niugini House on the property of Jacksons International Airport, Port Moresby. It operates a domestic network from Port Moresby to 12 major airports while its subsidiary company, Link PNG, operates routes to minor airports. It also operates international services in Asia, Oceania, and Australia on a weekly basis. Its main base is Jacksons International Airport, which is located in 7 Mile, Port Moresby, Papua New Guinea.Flight International 27 March 2007 ''Niugini'' is the Tok Pisin word for ''New Guinea''. History The airline was established in November 1973 as the national airline of Papua New Guinea with the government holding 60% of the shares, Ansett (16%), Qantas (12%) and Trans Australia Airlines (TAA) (12%). It started as an exclusively domestic carrier; however it expanded to offer international services shortly thereafter. In founding the airline, the government aimed to encourage region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxidase
Peroxidases or peroxide reductases ( EC numberbr>1.11.1.x are a large group of enzymes which play a role in various biological processes. They are named after the fact that they commonly break up peroxides. Functionality Peroxidases typically catalyze a reaction of the form: :ROOR' + \overset + 2H+ -> ce + R'OH Optimal substrates For many of these enzymes the optimal substrate is hydrogen peroxide, but others are more active with organic hydroperoxides such as lipid peroxides. Peroxidases can contain a heme cofactor in their active sites, or alternately redox-active cysteine or selenocysteine residues. The nature of the electron donor is very dependent on the structure of the enzyme. * For example, horseradish peroxidase can use a variety of organic compounds as electron donors and acceptors. Horseradish peroxidase has an accessible active site, and many compounds can reach the site of the reaction. * On the other hand, for an enzyme such as cytochrome c peroxidase, the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chi Rho
The Chi Rho (☧, English pronunciation ; also known as ''chrismon'') is one of the earliest forms of Christogram, formed by superimposing the first two (capital) letters— chi and rho (ΧΡ)—of the Greek word ( Christos) in such a way that the vertical stroke of the rho intersects the center of the chi. The Chi-Rho symbol was used by the Roman Emperor Constantine I (r. 306–337 AD) as part of a military standard (vexillum). Constantine's standard was known as the Labarum. Early symbols similar to the Chi Rho were the Staurogram () and the IX monogram (). In pre-Christian times, the Chi-Rho symbol was also used to mark a particularly valuable or relevant passage in the margin of a page, abbreviating ''chrēston'' (good). Some coins of Ptolemy III Euergetes (r. 246–222 BC) were marked with a Chi-Rho. Although formed of Greek characters, the device (or its separate parts) is frequently found serving as an abbreviation in Latin text, with endings added appropriate t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PX Index
The PX Index (until March 2006 the PX 50) is a capitalization-weighted index of major stocks that trade on the Prague Stock Exchange. Selected as the starting exchange day (a benchmark date) for the Index PX 50 was 5 April 1994 and its opening value was fixed at 1,000 points. At this time the index included 50 companies traded on the Prague Stock Exchange, accordingly named PX 50. In 2014 Prague Stock Exchange introduced total return index PX-TR, that share same base as PX Index, but unlike PX index take into account dividends. History PX-50 After an initial boom encouraged by voucher privatization (the top was in February 1994 retroactively calculated on 1245 points) the index started to decline fast, and ended the year 1994 with 557 points. In 1995 the decline continued (influenced by the Mexican crisis, that discouraged foreign investors from emerging markets) and the index reached its first bottom on 29 June with 387 points. Then the index increased slowly and ended the ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-Xylene
''p''-Xylene ( ''para''-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The ''p-'' stands for ''para-'', indicating that the two methyl groups in ''p''-xylene occupy the diametrically opposite substituent positions 1 and 4. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, ''o''-xylene and ''m''-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable. The odor threshold of ''p''-xylene is 0.62 parts per million (ppm). Production The production of ''p''-xylene is industrially significant, with annual demand estimated at 37 million tons in 2014, and still on the increase. ''p''-Xylene is produced by catalytic reforming of petroleum naphtha as part of the BTX aromatics (benzene, toluene and the xylene isomers) extracted from the catalytic reformate. The ''p''-xylene is then separated out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a sample of an original image; more samples typically provide more accurate representations of the original. The intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as red, green, and blue, or cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''sensel'' is sometimes used), while in yet other contexts (like MRI) it may refer to a set of component intensities for a spatial position. Etymology The w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phaeophyceae
Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, ''Macrocystis'', a kelp of the order Laminariales, may reach in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is ''Sargassum'', which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food. Between 1,500 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PX Clade
PX or px may refer to: In business * PX Index, index of the Prague Stock Exchange * Air Niugini (IATA airline code PX) * Part exchange, a type of contract * Post exchange An exchange is a type of retail store found on United States military installations worldwide. Originally akin to trading posts, they now resemble contemporary department stores or strip malls. Exact terminology varies by armed service; some examp ..., a store operated by the Army and Air Force Exchange Service on US Army posts * Praxair (stock symbol PX) * Power exchange, the entity that operates an electricity market through which electricity is traded * Phone Number Medicine * Medical prescription, (only if misprinted as the symbol "℞" can be mistaken for "Px") * Medical procedure, a Prognosis or Physical Exam * Patient experience Chemistry * p-Xylene (Paraxylene), an aromatic hydrocarbon, based on benzene with two methyl substituents, of which PX is the industrial symbol. * Peroxidase * Pyroxenes, common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stramenopiles
Stramenopile is a clade of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost (in which case relatedness to stramenopile ancestors is evident from other shared cytological features or from genetic similarity). Stramenopiles represent one of the three major clades in the SAR supergroup, along with Alveolata and Rhizaria. Members of the clade are referred to as 'stramenopiles'. Stramenopiles are eukaryotes; since they are neither fungi, animals, nor plants, they are classified as protists. Most stramenopiles are single-celled, but some are multicellular algae including some brown algae. The group includes a variety of algal protists, heterotrophic flagellates, opalines and closely related proteromonad flagellates (all endobionts in other organisms); the actinophryid heliozoa, and oomycetes. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroxenes
The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe II) or magnesium (Mg) and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium (Cr), aluminium (Al), magnesium (Mg), cobalt (Co), manganese (Mn), scandium (Sc), titanium (Ti), vanadium (V) or even iron (Fe II) or (Fe III). Although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes. They share a common structure consisting of single chains of silica tetrahedra. Pyroxenes that crystallize in the monoclinic system are known as clinopyroxenes and those that crystallize in the orthorhombic system are known as orthopyroxenes. The name ''pyroxene'' is derived from the Ancient Greek words for 'fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praxair
Praxair, Inc. was an American worldwide industrial gases company. Founded in 1907, Praxair was the largest industrial gases company in North and South America, and the third-largest worldwide by revenue. In 2018 it merged with Linde AG to form Linde plc. The Praxair name was discontinued on September 1, 2020 in the US. History The company was founded by Carl von Linde as Linde Air Products Company in 1907. During the First World War, however, it was confiscated and in 1917, it joined with 4 other chemical companies under the name '' Union Carbide and Carbon Corporation'', while maintaining a separate identity. Its degree of independence waxed and waned over the years, and in 1992, it was spun off as a subsidiary, ''Union Carbide Industrial Gases Inc.'', and renamed to ''Praxair'' when it became a formally independent company three years later. The name is derived from a combination of the Greek word "praxis", or practical application, and "air", the company's primary raw mater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
