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Bronze and Brass Ornamental Work
The use of bronze dates from remote antiquity. This important metal is an alloy composed of copper and tin, in proportion which vary slightly, but may be normally considered as nine parts of copper to one of tin. Other ingredients which are occasionally found are more or less accidental. The result is a metal of a rich golden brown colour, capable of being worked by casting — a process little applicable to its component parts, but peculiarly successful with bronze, the density and hardness of the metal allowing it to take any impression of a mould, however delicate. It is thus possible to create ornamental work of various kinds. The process of casting is known as cire perdue, and is the most primitive and most commonly employed through the centuries, having been described by the monk Theophilus, and also by Benvenuto Cellini. Briefly, it is as follows: a core, roughly representing the size and form of the object to be produced, is made of pounded brick, plaster or other similar substance and thoroughly dried. Upon this the artist overlays his wax, which he models to the degree required in his finished work. Passing from the core through the wax and projecting beyond are metal rods. The modelling being completed, called lost-wax casting, the outer covering which will form the mould has to be applied; this is a liquid formed of clay and plaster sufficiently thin to find its way into every detail of the wax model. Further coatings of liquid are applied, so that there is, when dry, a solid outer coating and a solid inner core held together by the metal rods, with the work of art modelled in wax between. Heat is applied and the wax melts and runs out, and the molten metal is poured in and occupies every detail which the wax had filled. When cool, the outer casing is carefully broken away, the core raked out as far as possible, the projecting rods are removed and the object modelled in wax appears in bronze. If further finish is required, it is obtained by tooling.
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  • 28 Nov 2022
Topic Review
Cryptography
Cryptography, or cryptology (from Ancient Greek: "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, converting readable information (plaintext) to unintelligible nonsense text (ciphertext), which can only be read by reversing the process (decryption). The sender of an encrypted (coded) message shares the decryption (decoding) technique only with intended recipients to preclude access from adversaries. The cryptography literature often uses the names "Alice" (or "A") for the sender, "Bob" (or "B") for the intended recipient, and "Eve" (or "E") for the eavesdropping adversary. Since the development of rotor cipher machines in World War I and the advent of computers in World War II, cryptography methods have become increasingly complex and their applications more varied. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in actual practice by any adversary. While it is theoretically possible to break into a well-designed system, it is infeasible in actual practice to do so. Such schemes, if well designed, are therefore termed "computationally secure"; theoretical advances (e.g., improvements in integer factorization algorithms) and faster computing technology require these designs to be continually reevaluated, and if necessary, adapted. Information-theoretically secure schemes that cannot be broken even with unlimited computing power, such as the one-time pad, are much more difficult to use in practice than the best theoretically breakable, but computationally secure, schemes. The growth of cryptographic technology has raised a number of legal issues in the Information Age. Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export. In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation. Cryptography also plays a major role in digital rights management and copyright infringement disputes in regard to digital media.
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  • 28 Nov 2022
Biography
Benjamin Hick
Benjamin Hick (1 August 1790 – 9 September 1842) was a successful English civil and mechanical engineer, art collector and patron;[1] his improvements to the steam engine and invention of scientific tools were held in high esteem by the engineering profession,[2] some of Hick's improvements became public property without claiming the patent rights he was entitled to.[3] He was born at Hudder
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  • 28 Nov 2022
Topic Review
Three Corpses
The sanshi 三尸 "Three Corpses" or sanchong 三蟲 "Three Worms" are a Daoist physiological belief that demonic creatures live inside the human body, and they seek to hasten the death of their host. These three supernatural parasites allegedly enter the person at birth, and reside in the three dantian "energy centers", respectively located within the head, chest, and abdomen. After their human host dies, they are freed from the body and become malevolent ghosts. The pernicious Three Corpses/Worms work to harm their host's health and fate by initiating sicknesses, inviting other disease-causing agents into the body, and reporting their host's transgressions to the gods. The Three Corpses are supposed to keep records of their host's misdeeds, ascend to tian "heaven" bimonthly on the night of Chinese sexagenary gengshen 庚申 "57th of the 60-day cycle" while the host is sleeping, and file reports to the Siming 司命 "Director of Destinies" who deducts a certain number of days from the person's life for each misdeed. One way of avoiding this bureaucratic snitching is to stay awake for the entire gengshen day and night, thus preventing the Three Corpses from leaving one's body (a belief later assimilated into the Japanese Kōshin 庚申 tradition). For a Daoist adept to achieve the longevity of a xian "transcendent; immortal", it was necessary to expel the Three Corpses from the body. Since these evil spirits feed upon decaying matter produced by grains being digested in the intestines, the practice of bigu "abstinence from grains and cereals" is the first step towards expelling them. Bigu alone will not eliminate the Three Corpses, but weakens them to the point where they can be killed with waidan alchemical drugs such as cinnabar, and ultimately eliminated through neidan meditation techniques.
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  • 28 Nov 2022
Biography
Thomas J. Biersteker
Thomas J. Biersteker (born May 2, 1950) is an American political scientist and a notable constructivism scholar. He became the first Curt Gasteyger Professor of International Security at the Graduate Institute of International and Development Studies (IHEID) in Geneva, Switzerland in 2007, where he is also a member of the Centre on Conflict, Development and Peacebuilding.[1] He is an active memb
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Topic Review
Ubasoku
Upāsaka (masculine) or Upāsikā (feminine) are from the Sanskrit and Pāli words for "attendant". This is the title of followers of Buddhism (or, historically, of Gautama Buddha) who are not monks, nuns, or novice monastics in a Buddhist order, and who undertake certain vows. In modern times they have a connotation of dedicated piety that is best suggested by terms such as "lay devotee" or "devout lay follower".
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  • 28 Nov 2022
Topic Review
Sacred Grove
A sacred grove or sacred woods are any grove of trees that are of special religious importance to a particular culture. Sacred groves feature in various cultures throughout the world. They were important features of the mythological landscape and cult practice of Celtic, Baltic, Germanic, ancient Greek, Near Eastern, Roman, and Slavic polytheism, and continue to occur in locations such as India, Japan, and West Africa. Examples of sacred groves include the Greco-Roman temenos, various Germanic words for sacred groves, and the Celtic nemeton, which was largely but not exclusively associated with Druidic practice. During the Northern Crusades, there was a common practice of building churches on the sites of sacred groves. The Lakota and various other North American tribes consider particular forests or other natural landmarks to be sacred. Singular trees which a community deems to hold religious significance are known as sacred trees.
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  • 28 Nov 2022
Biography
Stefan Molyneux
Stefan Basil Molyneux (born September 24, 1966) is a Canadian podcaster and YouTuber. Molyneux, a self-published author, usually speaks on topics including anarcho-capitalism, politics, relationships, race and intelligence, multiculturalism, libertarianism, anti-feminism,[1] and familial relationships. A supporter of Donald Trump's presidential campaign, he has been described as alt-right by P
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  • 28 Nov 2022
Topic Review
Topology of Uniform Convergence
In mathematics, a linear map is a mapping V → W between two modules (including vector spaces) that preserves the operations of addition and scalar multiplication. By studying the linear maps between two modules one can gain insight into their structures. If the modules have additional structure, like topologies or bornologies, then one can study the subspace of linear maps that preserve this structure.
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  • 28 Nov 2022
Topic Review
Nucleic Acid
Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a compound ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid). Nucleic acids are the most important of all biomolecules. They are found in abundance in all living things, where they function to create and encode and then store information in the nucleus of every living cell of every life-form organism on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus—to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded information is contained and conveyed via the nucleic acid sequence, which provides the 'ladder-step' ordering of nucleotides within the molecules of RNA and DNA. Strings of nucleotides are bonded to form helical backbones—typically, one for RNA, two for DNA—and assembled into chains of base-pairs selected from the five primary, or canonical, nucleobases, which are: adenine, cytosine, guanine, thymine, and uracil; note, thymine occurs only in DNA and uracil only in RNA. Using amino acids and the process known as protein synthesis, the specific sequencing in DNA of these nucleobase-pairs enables storing and transmitting coded instructions as genes. In RNA, base-pair sequencing provides for manufacturing new proteins that determine the frames and parts and most chemical processes of all life forms.
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  • 28 Nov 2022
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