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Scaif
Scaif is a polishing wheel infused with a mixture of olive oil and diamond dust used in the diamond cutting industry. It was invented in 1456 by Lodewyk van Bercken. With the scaif, it became possible to polish all the facets of the diamond symmetrically at angles that reflected the light best. This invention revolutionized the diamond cutting industry and correspondingly, much increased the popularity of diamonds. The scaif consists of a hard disk, parallel to the floor. The disk looks like and is rotated in the same way as a potter's wheel. On the top surface a film of olive oil and diamond dust is placed. Surrounding the disk is a circular frame to catch the oil that is spun off as the disk is rotated. Hovering just above the surface of the disk is a mechanical arm to hold the diamond. It can be finely adjusted, to move the diamond into the exact position needed for polishing the facets. As the facets are polished more diamond dust is produced, replenishing the supply. Exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polishing Wheel
Polishing is the process of creating a smooth and shiny surface by rubbing it or by applying a chemical treatment, leaving a clean surface with a significant specular reflection (still limited by the index of refraction of the material according to the Fresnel equations). In some materials (such as metals, glasses, black or transparent stones), polishing is also able to reduce diffuse reflection to minimal values. When an unpolished surface is magnified thousands of times, it usually looks like a succession of mountains and valleys. By repeated abrasion, those "mountains" are worn down until they are flat or just small "hills." The process of polishing with abrasives starts with a coarse grain size and gradually proceeds to the finer ones to efficiently flatten the surface imperfections and to obtain optimal results. Mechanical properties The strength of polished products can be higher than their unpolished counterparts owing to the removal of stress concentrations present in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Cutting
Diamond cutting is the practice of shaping a diamond from a rough stone into a faceted gem. Cutting diamonds requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty. The first guild of diamond cutters and polishers (Diamantaire) was formed in 1375 in Nuremberg, Germany, and led to the development of various types of "cut". This has two meanings in relation to diamonds. The first is the shape: square, oval, and so on. The second relates to the specific quality of cut within the shape, and the quality and price will vary greatly based on the cut quality. Since diamonds are one of the hardest materials, special diamond-coated surfaces are used to grind the diamond down. The first major development in diamond cutting came with the "Point Cut" during the later half of the 14th century: the Point Cut follows the natural shape of an octahedral rough diamond crystal, eliminating some waste in the cutting process. Diamond cutting, as well as overa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lodewyk Van Bercken
Lodewyk van Bercken (also known in French as ''Louis de Berquem'') was a mid- to late-15th century Flemish jeweller and diamond cutter, renowned in the industry for inventing the scaif. The device revolutionized the diamond cutting industry and contributed to increased popularity of diamonds. Van Bercken was born in Bruges. He is credited with inventing the scaif, a polishing wheel infused with a mixture of olive oil and diamond dust. With the scaif, it became possible to polish all the facets of the diamond symmetrically at angles that best reflected the light. Charles the Bold Charles the Bold, Duke of Burgundy became the patron of van Bercken and in the 1470s commissioned him to cut a 137 carat (27.4 g) stone that later became known as the Florentine Diamond. Van Bercken experimented with three diamonds belonging to Charles the Bold. One stone was the Beau Sancy, another became the property of Pope Sixtus V, and the third was given by Charles to Louis XI. Later Charles the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potter's Wheel
In pottery, a potter's wheel is a machine used in the shaping (known as throwing) of clay into round ceramic ware. The wheel may also be used during the process of trimming excess clay from leather-hard dried ware that is stiff but malleable, and for applying incised decoration or rings of colour. Use of the potter's wheel became widespread throughout the Old World but was unknown in the Pre-Columbian New World, where pottery was handmade by methods that included coiling and beating. A potter's wheel may occasionally be referred to as a "potter's lathe". However, that term is better used for another kind of machine that is used for a different shaping process, turning, similar to that used for shaping of metal and wooden articles. The pottery wheel is an important component to create arts and craft products. The techniques of jiggering and jolleying can be seen as extensions of the potter's wheel: in jiggering, a shaped tool is slowly brought down onto the plastic clay body t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Arm
A mechanical arm is a machine that mimics the action of a human arm. Mechanical arms are composed of multiple beams connected by hinges powered by actuators. One end of the arm is attached to a firm base while the other has a tool. They can be controlled by humans either directly or over a distance. A computer-controlled mechanical arm is called a robotic arm. However, a robotic arm is just one of many types of different mechanical arms. Mechanical arms can be as simple as tweezers or as complex as prosthetic arms. In other words, if a mechanism can grab an object, hold an object, and transfer an object just like a human arm, it can be classified as a mechanical arm. Recent advancements have been brought about to lead future improvements in the medical field with prosthetics and with the mechanical arm in general. When mechanical engineers build complex mechanical arms, the goal is for the arm to perform a task that ordinary human arms can not complete. History Robotic Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Jay Epstein
Edward Jay Epstein (born 1935) is an American investigative journalist and a former political science professor at Harvard University, the University of California, Los Angeles, and the Massachusetts Institute of Technology. Early life and education Epstein was born in New York City in 1935. He earned a Bachelor of Arts and Master of Arts in government from Cornell University. One of his professors at Cornell was Vladimir Nabokov, for whom Epstein worked part-time advising the writer on which recently released films he should see. In 1973, he received his PhD in government from Harvard University. He completed his master's thesis on the search for political truth which later became a top-selling book. Career Epstein taught courses at these universities for three years. While a graduate student at Cornell University in 1966, he published the book ''Inquest'', an influential critique of the Warren Commission probe into the John F. Kennedy assassination. After teaching at Harvard, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Cutting
Diamond cutting is the practice of shaping a diamond from a rough stone into a faceted gem. Cutting diamonds requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty. The first guild of diamond cutters and polishers (Diamantaire) was formed in 1375 in Nuremberg, Germany, and led to the development of various types of "cut". This has two meanings in relation to diamonds. The first is the shape: square, oval, and so on. The second relates to the specific quality of cut within the shape, and the quality and price will vary greatly based on the cut quality. Since diamonds are one of the hardest materials, special diamond-coated surfaces are used to grind the diamond down. The first major development in diamond cutting came with the "Point Cut" during the later half of the 14th century: the Point Cut follows the natural shape of an octahedral rough diamond crystal, eliminating some waste in the cutting process. Diamond cutting, as well as overa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutting Tools
In the context of machining, a cutting tool or cutter is typically a hardened metal tool that is used to cut, shape, and remove material from a workpiece by means of machining tools as well as abrasive tools by way of shear deformation. The majority of these tools are designed exclusively for metals. There are several different types of single edge cutting tools that are made from a variety of hardened metal alloys that are ground to a specific shape in order to perform a specific part of the turning process resulting in a finished machined part. Single edge cutting tools are used mainly in the turning operations performed by a lathe in which they vary in size as well as alloy composition depending on the size and the type of material being turned. These cutting tools are held stationary by what is known as a tool post which is what manipulates the tools to cut the material into the desired shape. Single edge cutting tools are also the means of cutting material performed by metal sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgian Inventions
Belgian may refer to: * Something of, or related to, Belgium * Belgians, people from Belgium or of Belgian descent * Languages of Belgium, languages spoken in Belgium, such as Dutch, French, and German *Ancient Belgian language, an extinct language formerly spoken in Gallia Belgica *Belgian Dutch or Flemish, a variant of Dutch *Belgian French, a variant of French *Belgian horse (other), various breeds of horse *Belgian waffle, in culinary contexts *SS Belgian, SS ''Belgian'', a cargo ship in service with F Leyland & Co Ltd from 1919 to 1934 *''The Belgian'', a 1917 American silent film See also * *Belgica (other) *Belgic (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
