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Paper Dart
A paper plane (also known as a paper airplane or paper dart in American English, or paper aeroplane in British English) is a toy aircraft, usually a glider, made out of a single folded sheet of paper or paperboard. It typically takes the form of a simple nose-heavy triangle thrown like a dart. The art of paper plane folding dates back to the 19th century, with roots in various cultures around the world, where they have been used for entertainment, education, and even as tools for understanding aerodynamics. The mechanics of paper planes are grounded in the fundamental principles of flight, including lift, thrust, drag, and gravity. By manipulating these forces through different folding techniques and designs, enthusiasts can create planes that exhibit a wide range of flight characteristics, such as distance, stability, agility, and time aloft. Competitions and events dedicated to paper plane flying highlight the skill and creativity involved in crafting the perfect design, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josephine De Karman
Josephine (Pipö) de Karman was the sister and life-partner of Theodore von Kármán. She is remembered as the benefactor of a foundation for art students. Born in Budapest, Josephine was the younger sister of four brothers: Elemer, Feri, Tódor, and Miklos.Theodore von Kármán with Lee Edson (1967) ''The Wind and Beyond'', Little, Brown and Company She and her mother joined Theodore when he became director of the aerodynamics laboratory in Aachen, Germany. In 1925, they moved to their new home at Maastrichterlaan 11, in nearby Vaals, the Netherlands. Our home in Vaals was similar to my father’s home in Buda. It had a huge high-ceilinged salon, a library, and numerous guest rooms. It was big, comfortable and altogether amiable. We eventually hired a Hungarian cook who became our most prized possession. My mother and my sister easily took over the organization of my social life, leaving me free for intellectual pursuits. … On weekends we threw open our home to students, assi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glide Ratio
In aerodynamics, the lift-to-drag ratio (or L/D ratio) is the lift generated by an aerodynamic body such as an aerofoil or aircraft, divided by the aerodynamic drag caused by moving through air. It describes the aerodynamic efficiency under given flight conditions. The L/D ratio for any given body will vary according to these flight conditions. For an aerofoil wing or powered aircraft, the L/D is specified when in straight and level flight. For a glider it determines the glide ratio, of distance travelled against loss of height. The term is calculated for any particular airspeed by measuring the lift generated, then dividing by the drag at that speed. These vary with speed, so the results are typically plotted on a 2-dimensional graph. In almost all cases the graph forms a U-shape, due to the two main components of drag. The L/D may be calculated using computational fluid dynamics or computer simulation. It is measured empirically by testing in a wind tunnel or in free flight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheet Metal
Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil (metal), foil or Metal leaf, leaf, and pieces thicker than 6 mm (0.25 in) are considered plate, such as plate steel, a class of structural steel. Sheet metal is available in flat pieces or coiled strips. The coils are formed by running a continuous sheet of metal through a roll slitting, roll slitter. In most of the world, sheet metal thickness is consistently specified in millimeters. In the U.S., the thickness of sheet metal is commonly specified by a traditional, non-linear measure known as its Sheet metal gauge, gauge. The larger the gauge number, the thinner the metal. Commonly used steel sheet metal ranges from 30 gauge (0.40 mm) to about 7 gauge (4.55 mm). Gauge differs between ferrous (Iron, iron-based) metals and nonferrous metals such as aluminum or copper. Copper thickness, for example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Printer
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a Electric charge, negatively charged cylinder called a "drum" to define a differentially charged image. The drum then selectively collects electrically charged powdered ink (toner (printing), toner), and transfers the image to paper, which is then heated to permanently fuse the text, imagery, or both to the paper. As with digital photocopiers, laser computer printer, printers employ a Xerography, xerographic printing process. Laser printing differs from traditional xerography as implemented in analog photocopiers in that in the latter, the image is formed by reflecting light off an existing document onto the exposed drum. The laser printer was invented at Xerox PARC (company), PARC in the 1970s. Laser printers were introduced for the office and then home markets in subsequent years by IBM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photocopier
A photocopier (also called copier or copy machine, and formerly Xerox machine, the generic trademark) is a machine that makes copies of documents and other visual images onto paper or plastic film quickly and cheaply. Most modern photocopiers use a technology called '' xerography'', a dry process that uses electrostatic charges on a light-sensitive photoreceptor to first attract and then transfer toner particles (a powder) onto paper in the form of an image. The toner is then fused onto the paper using heat, pressure, or a combination of both. Copiers can also use other technologies, such as inkjet, but xerography is standard for office copying. Commercial xerographic office photocopying gradually replaced copies made by verifax, photostat, carbon paper, mimeograph machines, and other duplicating machines. Photocopying is widely used in the business, education, and government sectors. While there have been predictions that photocopiers will eventually become obsol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Origami
) is the Japanese art of paper folding. In modern usage, the word "origami" is often used as an inclusive term for all folding practices, regardless of their culture of origin. The goal is to transform a flat square sheet of paper into a finished sculpture through folding and sculpting techniques. Modern origami practitioners generally discourage the use of cuts, glue, or markings on the paper. Origami folders often use the Japanese word ' to refer to designs which use cuts. In the detailed Japanese classification, origami is divided into stylized ceremonial origami (儀礼折り紙, ''girei origami'') and recreational origami (遊戯折り紙, ''yūgi origami''), and only recreational origami is generally recognized as origami. In Japan, ceremonial origami is generally called "origata" ( :ja:折形) to distinguish it from recreational origami. The term "origata" is one of the old terms for origami. The small number of basic origami folds can be combined in a variety of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balsa
''Ochroma pyramidale'', commonly known as balsa, is a large, fast-growing tree native to the Americas. It is the sole member of the genus ''Ochroma'', and is classified in the subfamily Bombacoideae of the mallow family Malvaceae. The tree is famous for its wide usage in woodworking, due to its softness and its high strength compared to its low density. The name ''balsa'' is the Spanish word for "raft" and the Portuguese word for ferry. A deciduous angiosperm, ''Ochroma pyramidale'' can grow up to 30 m tall, and is classified as a hardwood despite the wood itself being very soft; it is the softest commercial hardwood and is widely used because of its light weight. Balsa trees grow extremely fast, often up to 27 metres in 10–15 years, and do not usually live beyond 30 to 40 years. In terms of volume (as opposed to height) they may be the fastest growing tree known; Streets mentions one individual which grew tall and diameter at breast height during a period of fifteen mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bostik
Bostik is a manufacturer and distributor of adhesives and sealants for the construction, industrial and consumer markets. With annual sales of €2.7 billion in 2024, the company employs over 7,000 people and has a presence in more than 45 countries. Bostik is part of the French-based Arkema group. History In 1889, the Boston Blacking Company, a producer of leather colourings and dyes, was founded in Chelsea, Massachusetts. The company became the chemical branch of United Shoe Machinery Corporation (USMC) – an American leader in the shoemaking industry – and grew in several countries through mergers, acquisitions and organic growth. By the late 1920s, the Boston Blacking Company was established in 12 countries across three continents and employed over 1,000 chemists and technicians. A number of products had been launched under the Bostik brand as early as the 1940s and the company took on Bostik as a company name in the 1960s. In 1980, Bostik was taken over by the Conne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirigami
is a variation of origami, the Japanese art of folding paper. In , the paper is cut as well as being folded, resulting in a three-dimensional design that stands away from the page. typically does not use glue. Overview In the United States, the term was coined by Florence Temko from Japanese , , and , , in the title of her 1962 book, '', the Creative Art of Paper cutting''. The book achieved enough success that the word was accepted as the Western name for the art of paper cutting. Typically, starts with a folded base, which is then unfolded; cuts are then opened and flattened to make the finished design. Simple are usually symmetrical, such as snowflakes, pentagrams, or orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ... blossoms. A difference between and the ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propulsion
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived from two Latin words: ''wikt:pro, pro'', meaning'' before'' or ''forward''; and ''wikt:pellere, pellere'', meaning ''to drive''. A propulsion system consists of a source of mechanical power, and a ''propulsor'' (means of converting this power into propulsive force). Plucking a guitar string to induce a vibration, vibratory translation is technically a form of propulsion of the guitar string; this is not commonly depicted in this vocabulary, even though human muscles are considered to propel the fingertips. The motion of an object moving through a gravitational field is affected by the field, and within some frames of reference physicists speak of the gravitational field generating a force upon the object, but for general relativity, deep the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
