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Cultured Pearls
Cultured pearls are formed within a cultured pearl sac with human intervention in the interior of productive living molluscs in a variety of conditions depending upon the mollusc and the goals. Just as the same as natural pearls, cultured pearls can be cultivated in seawater or freshwater bodies. Nowadays, over 95% of the pearls available on the market would be cultured pearls. Development of a pearl A pearl is formed when the mantle tissue is injured by a parasite, an attack of a fish, or another event that damages the external fragile rim of the shell of a mollusk shell bivalve or gastropod. In response, the mantle tissue of the mollusk secretes nacre into the pearl sac, a cyst that forms during the healing process. Chemically speaking, this is calcium carbonate and a fibrous protein called conchiolin. As the nacre builds up in layers of minute aragonite tablets, it fills the growing pearl sac and eventually forms a pearl. Pearl#Natural pearls, Natural pearls are initiated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akoya Pearl
Akoya may refer to: ;People: * Akoya Sogi Japanese voice actress ;Other: * Akoya condominiums, is a 47-story, high-rise residential condominium located in Miami Beach * Akoya (gastropod), ''Akoya'' (gastropod), a genus of sea snails * Akoya akoya (''Calliostoma akoya''), a species of sea snail * Akoya pearl oyster (''Pinctada fucata''), a species of pearl oyster * LISA Akoya, a single engine light aircraft {{disambiguation Japanese feminine given names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palau
Palau,, officially the Republic of Palau and historically ''Belau'', ''Palaos'' or ''Pelew'', is an island country and microstate in the western Pacific. The nation has approximately 340 islands and connects the western chain of the Caroline Islands with parts of the Federated States of Micronesia. It has a total area of . The most populous island is Koror, home to the country's most populous city of the same name. The capital Ngerulmud is located on the nearby island of Babeldaob, in Melekeok State. Palau shares maritime boundaries with international waters to the north, the Federated States of Micronesia to the east, Indonesia to the south, and the Philippines to the northwest. The country was originally settled approximately 3,000 years ago by migrants from Maritime Southeast Asia. Palau was first drawn on a European map by the Czech missionary Paul Klein based on a description given by a group of Palauans shipwrecked on the Philippine coast on Samar. Palau islands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio-frequency Identification
Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder, a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to track inventory goods. Passive tags are powered by energy from the RFID reader's interrogating radio waves. Active tags are powered by a battery and thus can be read at a greater range from the RFID reader, up to hundreds of meters. Unlike a barcode, the tag does not need to be within the line of sight of the reader, so it may be embedded in the tracked object. RFID is one method of automatic identification and data capture (AIDC). RFID tags are used in many industries. For example, an RFID tag attached to an automobile during production can be used to track ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinctada Margaritifera
''Pinctada margaritifera'', commonly known as the black-lip pearl oyster, is a species of pearl oyster, a saltwater mollusk, a marine bivalve mollusk in the family Pteriidae. This species is common in the Indo-Pacific within tropical coral reefs. The ability of ''P. margaritifera'' to produce pearls means that the species is a valuable resource to humans. The oysters are harvested wild from coral reefs and are also commonly grown in aquaculture, both primarily taking place in the Indo-Pacific region. Description The common name of this species refers to the black coloring along the margins of the interior of the shell. Externally the shell is dark grayish brown or green, though white spots are common across the shell. Adults usually reach between in height. A distinctive feature of the species is that the hinge has no teeth. (The genera ''Pinctada'' and '' Pteria'' are often confused. In ''Pinctada'', the hinge is long and straight, the long end of the shell forms a right an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinctada Maxima
''Pinctada maxima'' is a species of pearl oyster, a marine bivalve mollusk in the family Pteriidae, the pearl oysters. There are two different color varieties: the Silver-lipped oyster and the Gold-lipped oyster. These bivalves are the largest pearl oysters in the world. They have a very strong inner shell layer composed of nacre, also known as "mother of pearl" and are important to the cultured pearl industry as they are cultivated to produce South Sea pearls. The South Sea pearl or Philippine pearl was declared by Philippine President Fidel Ramos as the national gem in 1996 through Proclamation No. 905. The oyster and pearl are depicted on the reverse side of the Philippine New Generation Currency Series 1,000-peso bill. Description ''Pinctada maxima'' oysters grow very large, up to in diameter. The two color varieties have different coloration in the outer edge of the interior. This mother of pearl or nacre is responsible for the color of the pearls that the oyster can p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which are only l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Saville-Kent
William Saville-Kent (10 July 1845 – 11 October 1908) was an English marine biologist and author. Early life Born in the town of Sidmouth in Devon, South West England on 10 July 1845, William Saville-Kent was the son of Samuel Saville Kent (7 July 1800 – 5 February 1872) and Mary Ann Windus (b. 1808 – May 1852), who was Samuel's first wife. William was the youngest of ten children from his father's first marriage. Samuel was employed as a "Factory Commissioner" for the Home Office, and inspected factories to ensure that they were properly implementing the worker safety measures regulated in the Factory Acts of 1833. As the acts sought to alleviate the harm done to children that were caused by unregulated working conditions in the factories, Samuel's “duties required him to inspect factories that employed women and children.” Despite having “ambitions for promotion,” Samuel “suffered from the effects of local gossip and disapproval,” as a consequence of him be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perles De Tahiti (1)
Perles may refer to * Perles, Aisne, a commune in the Aisne department in Picardie in northern France * Perles-et-Castelet, a commune in the Ariège department in southwestern France *Perles, the French name for Pieterlen, Switzerland * Alfred Perlès (1897–1990), Austrian-British writer *George Perles (1934–2020), American football coach *Joseph Perles (1835–1894), Hungarian rabbi *Micha Perles, Israeli mathematician **Perles configuration In geometry, the Perles configuration is a system of nine points and nine lines in the Euclidean plane for which every combinatorially equivalent realization has at least one irrational number as one of its coordinates. It can be constructed from ... * Tessalon Perles See also * Perle (other) * Perls {{Disambiguation, geo, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz ( to ) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . Spellings of ''X-ray(s)'' in English include the variants ''x-ray(s)'', ''xray(s)'', and ''X ray(s)''. The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalt Chloride
Cobalt chloride (cobalt paper) may refer to: * Cobalt(II) chloride (CoCl2) * Cobalt(III) chloride Cobalt(III) chloride or cobaltic chloride is an unstable and elusive compound of cobalt and chlorine with formula . In this compound, the cobalt atoms have a formal charge of +3.Arthur W. Chester, El-Ahmadi Heiba, Ralph M. Dessau, and William J. ... (CoCl3) {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
