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Synthesis Of Carbon Nanotubes
Techniques have been developed to produce carbon nanotubes (CNTs) in sizable quantities, including arc discharge, laser ablation, high-pressure carbon monoxide disproportionation, and chemical vapor deposition (CVD). Most of these processes take place in a vacuum or with process gases. CVD growth of CNTs can occur in a vacuum or at atmospheric pressure. Large quantities of nanotubes can be synthesized by these methods; advances in catalysis and continuous growth are making CNTs more commercially viable. Types Arc discharge Nanotubes were observed in 1991 in the carbon soot of graphite electrodes during an arc discharge, by using a current of 100 amps, that was intended to produce fullerenes. However the first macroscopic production of carbon nanotubes was made in 1992 by two researchers at NEC's Fundamental Research Laboratory. The method used was the same as in 1991. During this process, the carbon contained in the negative electrode sublimates because of the high-discharge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores. Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Etching
Plasma etching is a form of plasma processing used to fabricate integrated circuits. It involves a high-speed stream of glow discharge (plasma) of an appropriate gas mixture being shot (in pulses) at a sample. The plasma source, known as etch species, can be either charged (ions) or neutral (atoms and radicals). During the process, the plasma generates volatile etch products at room temperature from the chemical reactions between the elements of the material etched and the reactive species generated by the plasma. Eventually the atoms of the shot element embed themselves at or just below the surface of the target, thus modifying the physical properties of the target. Mechanisms Plasma generation A plasma is a high energetic condition in which a lot of processes can occur. These processes happen because of electrons and atoms. To form the plasma electrons have to be accelerated to gain energy. Highly energetic electrons transfer the energy to atoms by collisions. Three different pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annealing (materials Science)
In metallurgy and materials science, annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for an appropriate amount of time and then cooling. In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to a change in ductility and hardness. As the material cools it recrystallizes. For many alloys, including carbon steel, the crystal grain size and phase composition, which ultimately determine the material properties, are dependent on the heating rate and cooling rate. Hot working or cold working after the annealing process alters the metal structure, so further heat treatments may be used to achieve the properties required. With knowledge of the composition and phase diagram, heat treatment can be used to adj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cincinnati
The University of Cincinnati (UC or Cincinnati) is a public research university in Cincinnati, Ohio. Founded in 1819 as Cincinnati College, it is the oldest institution of higher education in Cincinnati and has an annual enrollment of over 44,000 students, making it the second largest university in Ohio. It is part of the University System of Ohio. The university has four major campuses, with Cincinnati's main uptown campus and medical campus in the Heights and Corryville neighborhoods, and branch campuses in Batavia and Blue Ash, Ohio. The university has 14 constituent colleges, with programs in architecture, business, education, engineering, humanities, the sciences, law, music, and medicine. The medical college includes a leading teaching hospital and several biomedical research laboratories, with developments made including a live polio vaccine and diphenhydramine. UC was also the first university to implement a co-operative education (co-op) model. The university is accre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PICT0111
The Picts were a group of peoples who lived in what is now northern and eastern Scotland (north of the Firth of Forth) during Late Antiquity and the Early Middle Ages. Where they lived and what their culture was like can be inferred from early medieval texts and Pictish stones. Their Latin name, , appears in written records from the 3rd to the 10th century. Early medieval sources report the existence of a distinct Pictish language, which today is believed to have been an Insular Celtic language, closely related to the Brittonic spoken by the Britons who lived to the south. Picts are assumed to have been the descendants of the Caledonii and other Iron Age tribes that were mentioned by Roman historians or on the world map of Ptolemy. The Pictish kingdom, often called Pictland in modern sources, achieved a large degree of political unity in the late 7th and early 8th centuries through the expanding kingdom of Fortriu, the Iron Age Verturiones. By the year 900, the resulting Pict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Research Council Of Canada
The National Research Council Canada (NRC; french: Conseil national de recherches Canada) is the primary national agency of the Government of Canada dedicated to science and technology research & development. It is the largest federal research & development organization in Canada. The Minister of Innovation, Science, and Economic Development (currently, François-Philippe Champagne) is responsible for the NRC. Mandate NRC is an agency of the Government of Canada, and its mandate is set out in the '' National Research Council Act''. Under the Act, the NRC is responsible for: * Undertaking, assisting or promoting scientific and industrial research in fields of importance to Canada; * Providing vital scientific and technological services to the research and industrial communities; * Investigating standards and methods of measurement; * Working on the standardization and certification of scientific and technical apparatus, instruments and materials used or usable by Canadian in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Université De Sherbrooke
The University of Sherbrooke ( French: Université de Sherbrooke) (UdS) is a large public French-language university in Quebec, Canada with campuses located in Sherbrooke and Longueuil, a suburb of Montreal approximately west of Sherbrooke. It is one of two universities in the Estrie region of Quebec (the other one being Bishop's University), and the only French-language university for the region. As of 2022, the Université de Sherbrooke is home to 31,000 students, and an additional 3,000 older learners (age 50+) in continuing education in its "University of the Third Age". Of its 7,400 employees, about 4,000 are teaching staff. The university has over 100,000 graduates and offers 46 undergraduate, 48 master's and 27 doctoral programs. It holds a total of 61 research chairs, among which are the pharmacology, microelectronics, statistical learning, and environment research chairs. Campus The Université de Sherbrooke has five campuses: * The Main Sherbrooke Campus * The Sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Plasma
Induction plasma, also called inductively coupled plasma, is a type of high temperature plasma generated by electromagnetic induction, usually coupled with argon gas. The magnetic field induces an electric current within the gas which creates the plasma. The plasma can reach temperatures up to 10,000 Kelvin. Inductive plasma technology is used in fields such as powder spheroidisation and nano-material synthesis. The technology is applied via an Induction plasma torch, which consists of three basic elements: the induction coil, a confinement chamber, and a torch head, or gas distributor. The main benefit of this technology is the elimination of electrodes, which can deteriorate and introduce contamination. History The 1960s were the incipient period of thermal plasma technology, spurred by the needs of aerospace programs. Among the various methods of thermal plasma generation, induction plasma (or inductively coupled plasma) takes up an important role. Early attempts to maintain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrocene
Ferrocene is an organometallic compound with the formula . The molecule is a complex consisting of two cyclopentadienyl rings bound to a central iron atom. It is an orange solid with a camphor-like odor, that sublimes above room temperature, and is soluble in most organic solvents. It is remarkable for its stability: it is unaffected by air, water, strong bases, and can be heated to 400 °C without decomposition. In oxidizing conditions it can reversibly react with strong acids to form the ferrocenium cation . The rapid growth of organometallic chemistry is often attributed to the excitement arising from the discovery of ferrocene and its many analogues, such as metallocenes. History Discovery Ferrocene was discovered by accident thrice. The first known synthesis may have been made in the late 1940s by unknown researchers at Union Carbide, who tried to pass hot cyclopentadiene vapor through an iron pipe. The vapor reacted with the pipe wall, creating a "yellow sludg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
