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Microcrystalline Wax
Microcrystalline waxes are a type of wax produced by de-oiling petrolatum, as part of the petroleum refining process. In contrast to the more familiar paraffin wax which contains mostly unbranched alkanes, microcrystalline wax contains a higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons. It is characterized by the fineness of its crystals in contrast to the larger crystal of paraffin wax. It consists of high molecular weight saturated aliphatic hydrocarbons. It is generally darker, more viscous, denser, tackier and more elastic than paraffin waxes, and has a higher molecular weight and melting point. The elastic and adhesive characteristics of microcrystalline waxes are related to the non-straight chain components which they contain. Typical microcrystalline wax crystal structure is small and thin, making them more flexible than paraffin wax. It is commonly used in cosmetic formulations. Microcrystalline waxes when produced by wax refiners are ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrolatum
Petroleum jelly, petrolatum, white petrolatum, soft paraffin, or multi-hydrocarbon, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25), originally promoted as a topical ointment for its healing properties. The Vaseline brand is a well known American brand of petroleum jelly since 1870. After petroleum jelly became a medicine-chest staple, consumers began to use it for cosmetic purposes and for many ailments including toenail fungus, genital rashes (non- STD), nosebleeds, diaper rash, and common colds. Its folkloric medicinal value as a "cure-all" has since been limited by better scientific understanding of appropriate and inappropriate uses. It is recognized by the U.S. Food and Drug Administration (FDA) as an approved over-the-counter (OTC) skin protectant and remains widely used in cosmetic skin care, where it is often loosely referred to as mineral oil. History Marco Polo in 1273 described the oil exportation of Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystal, crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of Three-dimensional space (mathematics), three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive Translation (geometry), translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of the crystal are described by the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waxes
Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in nonpolar organic solvents such as hexane, benzene and chloroform. Natural waxes of different types are produced by plants and animals and occur in petroleum. Chemistry Waxes are organic compounds that characteristically consist of long aliphatic alkyl chains, although aromatic compounds may also be present. Natural waxes may contain unsaturated bonds and include various functional groups such as fatty acids, primary and secondary alcohols, ketones, aldehydes and fatty acid esters. Synthetic waxes often consist of homologous series of long-chain aliphatic hydrocarbons (alkanes or paraffins) that lack functional groups. Plant and animal waxes Waxes are synthesized by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmetics Chemicals
Cosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect the body or skin. Cosmetics designed to enhance or alter one's appearance (makeup) can be used to conceal blemishes, enhance one's natural features (such as the eyebrows and eyelashes), add color to a person's face, or change the appearance of the face entirely to resemble a different person, creature or object. Cosmetics can also be designed to add fragrance to the body. Definition and etymology The word ''cosmetics'' derives from the Greek (), meaning "technique of dress and ornament", from (), "skilled in ordering or arranging" and that from (), meaning "order" and "ornament". Cosmetics are constituted from a mixture of chemical compounds derived from either natural sources, or synthetically created ones. Legal definition Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westminster Abbey
Westminster Abbey, formally titled the Collegiate Church of Saint Peter at Westminster, is an historic, mainly Gothic church in the City of Westminster, London, England, just to the west of the Palace of Westminster. It is one of the United Kingdom's most notable religious buildings and since Edward the Confessor, a burial site for English and, later, British monarchs. Since the coronation of William the Conqueror in 1066, all coronations of English and British monarchs have occurred in Westminster Abbey. Sixteen royal weddings have occurred at the abbey since 1100. According to a tradition first reported by Sulcard in about 1080, a church was founded at the site (then known as Thorney Island) in the seventh century, at the time of Mellitus, Bishop of London. Construction of the present church began in 1245 on the orders of Henry III. The church was originally part of a Catholic Benedictine abbey, which was dissolved in 1539. It then served as the cathedral of the Dioce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmati
The Cosmati were a Roman family, seven members of which, for four generations, were skilful architects, sculptors and workers in decorative geometric mosaic, mostly for church floors. Their name is commemorated in the genre of Cosmatesque work, often just called "Cosmati", a technique of ''opus sectile'' ("cut work") formed of elaborate inlays of small triangles and rectangles of colored stones and glass mosaics set into stone matrices or encrusted upon stone surfaces. Bands, panels and shaped reserves of intricate mosaic alternate with contrasting bands, guilloches and simple geometric shapes of plain white marble. Pavements and revetments were executed in Cosmatesque technique, columns were inlaid with fillets and bands, and immovable church furnishings like cathedras and '' ambones'' were similarly treated. In addition, members of the Cosmati engaged in commerce in ancient sculptures, some unearthed in the course of excavating for marbles for reuse. More than one ancient Roma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Hockey Stick
An ice hockey stick is a piece of equipment used in ice hockey to shoot, pass, and carry the puck across the ice. Ice hockey sticks are approximately 150–200 cm long, composed of a long, slender shaft with a flat extension at one end called the blade. National Hockey League (NHL) sticks are up to 63 inches (160 cm) long. The blade is the part of the stick used to contact the puck, and is typically 25 to 40 cm long. Stick dimensions can vary widely, as they are usually built to suit a particular player's size and preference. The blade is positioned at roughly a 135° angle from the axis of the shaft, giving the stick a partly 'L-shaped' appearance. The shaft of the stick is fairly rigid, but is slightly elastic to improve shot performance. The blade is slightly curved to aid control of the puck, especially in shooting. The direction of the curve depends on the side of the body the player wields the stick on. The goaltender has a slightly modified stick. The lower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction Tape
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowboarding
Snowboarding is a recreational and competitive activity that involves descending a snow-covered surface while standing on a snowboard that is almost always attached to a rider's feet. It features in the Winter Olympic Games and Winter Paralympic Games. Snowboarding was developed in the United States, inspired by skateboarding, sledding, surfing, and skiing. It became popular around the globe, and was introduced as a Winter Olympic Sport at Nagano in 1998 and featured in the Winter Paralympics at Sochi in 2014. , its popularity (as measured by equipment sales) in the United States peaked in 2007 and has been in a decline since. History The first snowboards were developed in 1965 when Sherman Poppen, an engineer in Muskegon, Michigan, invented a toy for his daughters by fastening two skis together and attaching a rope to one end so he would have some control as they stood on the board and glided downhill. Dubbed the "snurfer" (combining snow and surfer) by his wife Nancy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Hockey
Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an ice skating rink with lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two opposing teams use ice hockey sticks to control, advance and shoot a closed, vulcanized, rubber disc called a " puck" into the other team's goal. Each goal is worth one point. The team which scores the most goals is declared the winner. In a formal game, each team has six skaters on the ice at a time, barring any penalties, one of whom is the goaltender. Ice hockey is a full contact sport. Ice hockey is one of the sports featured in the Winter Olympics while its premiere international amateur competition, the IIHF World Championships, are governed by the International Ice Hockey Federation (IIHF) for both men's and women's competitions. Ice hockey is also played as a professional sport. In North America as well as many European countries, the sport is known simply ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Printing Ink
Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, reed pen, or quill. Thicker inks, in paste form, are used extensively in letterpress and lithographic printing. Ink can be a complex medium, composed of solvents, pigments, dyes, resins, lubricants, solubilizers, surfactants, particulate matter, fluorescents, and other materials. The components of inks serve many purposes; the ink's carrier, colorants, and other additives affect the flow and thickness of the ink and its dry appearance. In 2011, worldwide consumption of printing inks generated revenues of more than 20 billion US dollars. While demand by traditional print media (including newspapers) is shrinking; more and more printing inks are consumed for packaging. History Many ancient cultures around the world have independently discovered and formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The British Museum
The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It documents the story of human culture from its beginnings to the present.Among the national museums in London, sculpture and decorative and applied art are in the Victoria and Albert Museum; the British Museum houses earlier art, non-Western art, prints and drawings. The National Gallery holds the national collection of Western European art to about 1900, while art of the 20th century on is at Tate Modern. Tate Britain holds British Art from 1500 onwards. Books, manuscripts and many works on paper are in the British Library. There are significant overlaps between the coverage of the various collections. The British Museum was the first public national museum to cover all fields of knowledge. The museum was established in 1753, largely based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
