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D-Shape
D-Shape is a large 3-dimensional printer that uses binder-jetting, a layer by layer printing process, to bind sand with an inorganic seawater and magnesium-based binder in order to create stone-like objects. Invented by Enrico Dini, founder of Monolite UK Ltd, the first model of the D-Shape printer used epoxy resin, commonly used as an adhesive in the construction of skis, cars, and airplanes, as the binder. Dini patented this model in 2006. After experiencing problems with the epoxy, Dini changed the binder to the current magnesium-based one and patented his printer again in September 2008. In the future, Dini aims to use the printer to create full-scale buildings. Technical description The current version of the D-Shape 3-D printer sits in a 6m by 6m aluminum frame. The frame consists of a square base that moves upwards along four vertical beams during the printing process via stepper motors, which are used to repeatedly move a specified length and then hold in place, on each bea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder Bed And Inkjet Head 3D Printing
Binder jet 3D printing, known variously as "Powder bed and inkjet" and "drop-on-powder" printing, is a rapid prototyping and additive manufacturing technology for making objects described by digital data such as a CAD file. Binder jetting is one of the seven categories of additive manufacturing processes according to ASTM and ISO. History This technology was first developed at the Massachusetts Institute of Technology and patented in 1993. In 1996, the ExOne Company was granted an exclusive field-of-use patent for the technology, while Z Corporation, which was later acquired by 3D Systems, obtained a non-exclusive patent for use of the technology for metal casting purposes. The term "Three-Dimensional Printing" was trademarked by the research group at MIT, along with the abbreviation 3DP. As a result, the term "3D printing" originally referred uniquely to the binder jet printing process prior to gaining wider acceptance as a term referring to all additive manufacturing process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxy
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called ''epoxy''. The IUPAC name for an epoxide group is an oxirane. Epoxy resins may be reacted ( cross-linked) either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols and thiols (usually called mercaptans). These co-reactants are often referred to as hardeners or curatives, and the cross-linking reaction is commonly referred to as curing. Reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, composites, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stepper Motor
A stepper motor, also known as step motor or stepping motor, is a brushless DC electric motor that divides a full rotation into a number of equal steps. The motor's position can be commanded to move and hold at one of these steps without any position sensor for feedback (an open-loop controller), as long as the motor is correctly sized to the application in respect to torque and speed. Switched reluctance motors are very large stepping motors with a reduced pole count, and generally are closed-loop commutated. Mechanism Brushed DC motors rotate continuously when DC voltage is applied to their terminals. The stepper motor is known for its property of converting a train of input pulses (typically square waves) into a precisely defined increment in the shaft’s rotational position. Each pulse rotates the shaft through a fixed angle. Stepper motors effectively have multiple "toothed" electromagnets arranged as a stator around a central rotor, a gear-shaped piece of iron. The e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer-aided Design
Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing. Designs made through CAD software are helpful in protecting products and inventions when used in patent applications. CAD output is often in the form of electronic files for print, machining, or other manufacturing operations. The terms computer-aided drafting (CAD) and computer aided design and drafting (CADD) are also used. Its use in designing electronic systems is known as '' electronic design automation'' (''EDA''). In mechanical design it is known as ''mechanical design automation'' (''MDA''), which includes the process of creating a technical drawing with the use of computer software. CAD software for mechanical design uses either vector-based graphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Chloride
Magnesium chloride is the family of inorganic compounds with the formula , where x can range from 0 to 12. These salts are colorless or white solids that are highly soluble in water. These compounds and their solutions, both of which occur in nature, have a variety of practical uses. Anhydrous magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form most readily available. Production Magnesium chloride can be extracted from brine or sea water. In North America, it is produced primarily from Great Salt Lake brine. In the Jordan Valley, it is obtained from the Dead Sea. The mineral bischofite () is extracted (by solution mining) out of ancient seabeds, for example, the Zechstein seabed in northwest Europe. Some deposits result from high content of magnesium chloride in the primordial ocean. Some magnesium chloride is made from evaporation of seawater. In the Dow process, magnesium chloride is re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorel Cement
Sorel cement (also known as magnesia cement or magnesium oxychloride) is a non-hydraulic cement first produced by the French chemist Stanislas Sorel in 1867.Sorel Stanislas (1867).Sur un nouveau ciment magnésien. ''Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences'', volume 65, pages 102–104. In fact, in 1855, before working with magnesium compounds, Stanislas Sorel first developed a two-component cement by mixing zinc oxide powder with a solution of zinc chloride.Sorel Stanislas (1856). Procédé pour la formation d'un ciment très-solide par l'action d'un chlorure sur l'oxyde de zinc. Bulletin de la Société d'Encouragement pour l'Industrie Nationale, 55, 51–53. In a few minutes he obtained a dense material harder than limestone. Only a decade later, Sorel replaced zinc with magnesium in his formula and also obtained a cement with similar favorable properties. This new type of cement was stronger and more elastic than Portland cement, and therefore e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcrystalline
A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination. There is little agreement on the range of crystal sizes that should be regarded as microcrystalline, but the extreme range of values suggested is 1 to 200 microns. See also * Macrocrystalline * Nanocrystalline silicon * Microcrystalline cellulose * Microcrystalline wax * Protocrystalline * Rock microstructure Rock microstructure includes the texture and small-scale structures of a rock. The words ''texture'' and ''microstructure'' are interchangeable, with the latter preferred in modern geological literature. However, ''texture'' is still acceptable ... References Mineralogy concepts Petrology concepts {{Petrology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland Cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th century by Joseph Aspdin, and is usually made from limestone. It is a fine powder, produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding 2 to 3 percent of gypsum. Several types of portland cement are available. The most common, called ordinary portland cement (OPC), is grey, but white Portland cement is also available. Its name is derived from its resemblance to Portland stone which was quarried on the Isle of Portland in Dorset, England. It was named by Joseph Aspdin who obtained a patent for it in 1824. His son William Aspdin is regarded as the inventor of "modern" portland cement due to his developments in the 1840s. The low cost and widespread availability of the limestone, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City Economic Development Corporation
New York City Economic Development Corporation (NYCEDC) is a nonprofit corporation whose stated mission is to "leverage the city’s assets to create beneficial jobs that drive growth. This ensures equitable and sustainable development across all five boroughs." History NYCEDC was formed in 1991 as the result of a merger of two major not-for-profit and a handful of minor corporations which performed economic development services for the City. One of the major merger partners was the Public Development Corporation (PDC), formed in 1966 to rescue the City from its then-deteriorating economy by selling City property and leasing industrial space. PDC was responsible for construction of the Nassau Street Mall, the Brooklyn Army Terminal, Jamaica Center, and the South Street Seaport, among other activities. The second major merger partner was the Financial Services Corporation (FSC) formed in 1980 to administer government financing programs that promote business expansion in New Y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiolaria
The Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The elaborate mineral skeleton is usually made of silica. They are found as zooplankton throughout the global ocean. As zooplankton, radiolarians are primarily heterotrophic, but many have photosynthetic endosymbionts and are, therefore, considered mixotrophs. The skeletal remains of some types of radiolarians make up a large part of the cover of the ocean floor as siliceous ooze. Due to their rapid change as species and intricate skeletons, radiolarians represent an important diagnostic fossil found from the Cambrian onwards. Description Radiolarians have many needle-like pseudopods supported by bundles of microtubules, which aid in the radiolarian's buoyancy. The cell nucleus and most other organelles are in the endoplasm, while the ectopla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trullo
A trullo (plural, trulli) is a traditional Apulian dry stone hut with a conical roof. Their style of construction is specific to the Itria Valley, in the Murge area of the Italian region of Apulia. Trulli were generally constructed as temporary field shelters and storehouses or as permanent dwellings by small proprietors or agricultural labourers. In the town of Alberobello, in the province of Bari, whole districts contain dense concentrations of trulli. The golden age of trulli was the nineteenth century, especially its final decades, which were marked by the development of wine growing. From the to the The Italian term ''trullo'' (from the Greek word , cupola) refers to a house whose internal space is covered by a dry stone corbelled or keystone vault. is an Italianized form of the dialectal term, , used in a specific area of the Salentine peninsula (i.e. Lizzaio, Maruggio, and Avetrana, in other words, outside the Murgia dei Trulli proper), where it is the name of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Space Agency
, owners = , headquarters = Paris, Île-de-France, France , coordinates = , spaceport = Guiana Space Centre , seal = File:ESA emblem seal.png , seal_size = 130px , image = Views in the Main Control Room (12052189474).jpg , size = , caption = , acronym = , established = , employees = 2,200 , administrator = Director General Josef Aschbacher , budget = €7.2 billion (2022) , language = English and French (working languages) , website = , logo = European Space Agency logo.svg , logo_caption = Logo , image_caption = European Space Operations Centre (ESOC) Main Control Room The European Space Agency (ESA; french: Agence spatiale européenne , it, Agenzia Spaziale Europea, es, Agencia Espacial Europea ASE; german: Europäische Weltraumorganisation) is an intergovernmental organisation of 22 member states dedicated to the exploration of space. Established in 1975 and headquartere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
