IBM Selectric typewriter
The IBM Selectric typewriter was a highly successful model line of electric typewriters introduced by IBM on 31 July 1961. The Selectric replaced the traditional typewriters moving carriage with a roller that stayed in position while the typeball. The Selectric mechanism was notable for using internal mechanical binary coding and their descendants eventually captured 75 percent of the United States market for electric typewriters used in business. IBM replaced the Selectric line with the IBM Wheelwriter in 1984, the Selectric typewriter was introduced on 23 July 1961. Its industrial design is credited to influential American designer Eliot Noyes, Noyes had worked on a number of design projects for IBM, prior to his work on the Selectric, he had been commissioned in 1956 by Thomas J. Watson, Jr. The Selectric remained unchanged until 1971 when the Selectric II was introduced, the original design was thereafter referred to as the Selectric I. These machines used the same 88-character typing elements, separate typeballs were available for each pitch.
The Selectric II had a lever that allowed characters to be shifted up to a space to the left. This option was only on dual pitch models. Stylistically, the Selectric II was squarer at the corners, whereas the Selectric I was rounder, in 1973 the Correcting Selectric II was announced. It added an internal correction feature to the Selectric II, intended to eliminate the need for typists to use cover-up tape, white-out correction fluid, the carriage on this machine held both the main typing ribbon cartridge and two small spools for a correction ribbon. A new ribbon type, the Correctable Film ribbon, was introduced at the same time and this produced typing quality equal to the carbon film ribbon, but with a pigment designed to be easily removable from paper. There were two types of correction tapes, The transparent and slightly adhesive Lift-Off tape, or the white Cover-Up tape, the correction tape was changed independently from the typing ribbon. The typist would press the key and re-type the erroneous character, either lifting it off of the page or covering it with white-out powder.
Any number of mistakes could be corrected this way, but the process was entirely manual, in 1964 IBM introduced the Magnetic Tape Selectric Typewriter and in 1969, a Magnetic Card Selectric Typewriter. These were sometimes referred to as the MT/ST and MC/ST, the MC/ST was available in a communicating version that could emulate an IBM2741 terminal or run its native Correspondence Code. These featured electronically interfaced typing mechanisms and keyboards and a storage device for recording, editing. These machines were among the first to word processing capability in any form
Great Britain, known as Britain, is a large island in the north Atlantic Ocean off the northwest coast of continental Europe. With an area of 209,331 km2, Great Britain is the largest European island, in 2011 the island had a population of about 61 million people, making it the worlds third-most populous island after Java in Indonesia and Honshu in Japan. The island of Ireland is situated to the west of it, the island is dominated by a maritime climate with quite narrow temperature differences between seasons. Politically, the island is part of the United Kingdom of Great Britain and Northern Ireland, most of England and Wales are on the island. The term Great Britain often extends to surrounding islands that form part of England and Wales. A single Kingdom of Great Britain resulted from the union of the Kingdom of England, the archipelago has been referred to by a single name for over 2000 years, the term British Isles derives from terms used by classical geographers to describe this island group.
By 50 BC Greek geographers were using equivalents of Prettanikē as a name for the British Isles. However, with the Roman conquest of Britain the Latin term Britannia was used for the island of Great Britain, the oldest mention of terms related to Great Britain was by Aristotle, or possibly by Pseudo-Aristotle, in his text On the Universe, Vol. III. To quote his works, There are two large islands in it, called the British Isles and Ierne. The name Britain descends from the Latin name for Britain, Britannia or Brittānia, Old French Bretaigne and Middle English Bretayne, Breteyne. The French form replaced the Old English Breoton, Bryten, Britannia was used by the Romans from the 1st century BC for the British Isles taken together. It is derived from the writings of the Pytheas around 320 BC. Marcian of Heraclea, in his Periplus maris exteri, described the group as αἱ Πρεττανικαὶ νῆσοι. The peoples of these islands of Prettanike were called the Πρεττανοί, Priteni is the source of the Welsh language term Prydain, which has the same source as the Goidelic term Cruithne used to refer to the early Brythonic-speaking inhabitants of Ireland.
The latter were called Picts or Caledonians by the Romans, the Greco-Egyptian scientist Ptolemy referred to the larger island as great Britain and to Ireland as little Britain in his work Almagest. The name Albion appears to have out of use sometime after the Roman conquest of Britain. After the Anglo-Saxon period, Britain was used as a term only. It was used again in 1604, when King James VI and I styled himself King of Great Brittaine, Great Britain refers geographically to the island of Great Britain, politically to England and Wales in combination
Mechanical-scanning methods were used in the earliest television systems in the 1920s and 1930s. One of the first experimental wireless television transmissions was by John Logie Baird on November 25,1925, by 1928 many radio stations were broadcasting experimental television programs using mechanical systems. However the technology never produced images of sufficient quality to become popular with the public, a mechanical television receiver is called a televisor in some countries. The invention of the television was the work of people in the 19th century. Facsimile transmission systems for still photographs pioneered methods of mechanical scanning of images in early 19th century, alexander Bain introduced the facsimile machine in 1843 to 1846. Frederick Bakewell demonstrated a working version in 1851. The first practical system, working on telegraph lines, was developed. Willoughby Smith discovered the photoconductivity of the element selenium in 1873, as a 23-year-old German university student, Paul Julius Gottlieb Nipkow proposed and patented the Nipkow disk in 1884.
This was a disk with a spiral pattern of holes in it. Although he never built a model of the system, Nipkows spinning-disk image rasterizer was the key mechanism used in most mechanical scan systems. Constantin Perskyi had coined the word television in a paper read to the International Electricity Congress at the International World Fair in Paris on August 25,1900, perskyis paper reviewed the existing electromechanical technologies, mentioning the work of Nipkow and others. However, it was not until 1907 that developments in amplification tube technology, by Lee de Forest and Arthur Korn among others, the first demonstration of the instantaneous transmission of images was by Georges Rignoux and A. Fournier in Paris in 1909. A matrix of 64 selenium cells, individually wired to a mechanical commutator, in the receiver, a type of Kerr cell modulated the light and a series of variously angled mirrors attached to the edge of a rotating disc scanned the modulated beam onto the display screen. The 8x8 pixel resolution in this demonstration was just sufficient to clearly transmit individual letters of the alphabet.
An updated image was transmitted several times each second, moving images were not possible because, in the scanner, the sensitivity was not enough and the selenium cell was very laggy. By the 1920s when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems, on March 25,1925, Baird gave the first public demonstration of televised silhouette images in motion, at Selfridges Department Store in London. Since human faces had inadequate contrast to show up on his system, he televised a ventriloquists dummy named Stooky Bill talking and moving. By January 26,1926, he demonstrated the transmission of image of a face in motion by radio and this is widely regarded as first television demonstration
Piezoelectricity /piˌeɪzoʊˌilɛkˈtrɪsɪti/ is the electric charge that accumulates in certain solid materials in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure and it is derived from the Greek piezō or piezein, which means to squeeze or press, and ēlektron, which means amber, an ancient source of electric charge. Piezoelectricity was discovered in 1880 by French physicists Jacques and Pierre Curie, the piezoelectric effect is understood as the linear electromechanical interaction between the mechanical and the electrical state in crystalline materials with no inversion symmetry. The piezoelectric effect is a process in that materials exhibiting the direct piezoelectric effect exhibit the reverse piezoelectric effect. For example, lead zirconate titanate crystals will generate measurable piezoelectricity when their structure is deformed by about 0. 1% of the original dimension. Conversely, those same crystals will change about 0. 1% of their static dimension when an electric field is applied to the material.
The inverse piezoelectric effect is used in the production of sound waves. The pyroelectric effect, by which a material generates a potential in response to a temperature change, was studied by Carl Linnaeus. Drawing on this knowledge, both René Just Haüy and Antoine César Becquerel posited a relationship between stress and electric charge, experiments by both proved inconclusive. The first demonstration of the piezoelectric effect was in 1880 by the brothers Pierre Curie. Quartz and Rochelle salt exhibited the most piezoelectricity, the Curies, did not predict the converse piezoelectric effect. The converse effect was mathematically deduced from fundamental principles by Gabriel Lippmann in 1881. For the next few decades, piezoelectricity remained something of a laboratory curiosity, more work was done to explore and define the crystal structures that exhibited piezoelectricity. The first practical application for piezoelectric devices was sonar, first developed during World War I, in France in 1917, Paul Langevin and his coworkers developed an ultrasonic submarine detector.
The detector consisted of a transducer, made of quartz crystals carefully glued between two steel plates, and a hydrophone to detect the returned echo. The use of piezoelectricity in sonar, and the success of that project, over the next few decades, new piezoelectric materials and new applications for those materials were explored and developed. Piezoelectric devices found homes in many fields, ceramic phonograph cartridges simplified player design, were cheap and accurate, and made record players cheaper to maintain and easier to build. The development of the ultrasonic transducer allowed for easy measurement of viscosity and elasticity in fluids and solids, ultrasonic time-domain reflectometers could find flaws inside cast metal and stone objects, improving structural safety
In electricity generation, a generator is a device that converts mechanical energy to electrical energy for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, the first electromagnetic generator, the Faraday disk, was built in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids, the reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities. Many motors can be driven to generate electricity and frequently make acceptable manual generators. Electromagnetic generators fall into one of two categories and alternators. The magnetic field of the dynamo or alternator can be provided by either wire windings called field coils or permanent magnets, a generator using permanent magnets is sometimes called a magneto. Armature, The power-producing component of an electrical machine, in a generator, alternator, or dynamo the armature windings generate the electric current, which provides power to an external circuit.
The armature can be on either the rotor or the stator, depending on the design, before the connection between magnetism and electricity was discovered, electrostatic generators were invented. They operated on electrostatic principles, by using moving electrically charged belts, the charge was generated using either of two mechanisms, electrostatic induction or the triboelectric effect. Such generators generated very high voltage and low current and their only practical applications were to power early X-ray tubes, and in some atomic particle accelerators. The operating principle of electromagnetic generators was discovered in the years of 1831–1832 by Michael Faraday, the principle called Faradays law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux. He built the first electromagnetic generator, called the Faraday disk and it produced a small DC voltage. This design was inefficient, due to self-cancelling counterflows of current in regions of the disk that were not under the influence of the magnetic field.
While current was induced directly underneath the magnet, the current would circulate backwards in regions that were outside the influence of the magnetic field and this counterflow limited the power output to the pickup wires, and induced waste heating of the copper disc. Later homopolar generators would solve this problem by using an array of magnets arranged around the perimeter to maintain a steady field effect in one current-flow direction. Another disadvantage was that the voltage was very low, due to the single current path through the magnetic flux. Experimenters found that using multiple turns of wire in a coil could produce higher, since the output voltage is proportional to the number of turns, generators could be easily designed to produce any desired voltage by varying the number of turns. Wire windings became a feature of all subsequent generator designs
Hydroelectricity is electricity produced from hydropower. In 2015 hydropower generated 16. 6% of the total electricity and 70% of all renewable electricity. Hydropower is produced in 150 countries, with the Asia-Pacific region generating 33 percent of global hydropower in 2013, China is the largest hydroelectricity producer, with 920 TWh of production in 2013, representing 16.9 percent of domestic electricity use. The cost of hydroelectricity is relatively low, making it a source of renewable electricity. The hydro station consumes no water, unlike coal or gas plants, the average cost of electricity from a hydro station larger than 10 megawatts is 3 to 5 U. S. cents per kilowatt-hour. With a dam and reservoir it is a source of electricity since the amount produced by the station can be changed up or down very quickly to adapt to changing energy demands. Once a hydroelectric complex is constructed, the project produces no direct waste, Hydropower has been used since ancient times to grind flour and perform other tasks.
In the mid-1770s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique which described vertical-, by the late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand for the Industrial Revolution would drive development as well, in 1878 the worlds first hydroelectric power scheme was developed at Cragside in Northumberland, England by William George Armstrong. It was used to power an arc lamp in his art gallery. The old Schoelkopf Power Station No.1 near Niagara Falls in the U. S. side began to produce electricity in 1881. The first Edison hydroelectric power station, the Vulcan Street Plant, began operating September 30,1882, in Appleton, Wisconsin, by 1886 there were 45 hydroelectric power stations in the U. S. and Canada. By 1889 there were 200 in the U. S. alone, at the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas.
Grenoble, France held the International Exhibition of Hydropower and Tourism with over one million visitors, by 1920 as 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land, as the power stations became larger, their associated dams developed additional purposes to include flood control and navigation. Federal funding became necessary for development and federally owned corporations, such as the Tennessee Valley Authority. Hydroelectric power stations continued to become larger throughout the 20th century, Hydropower was referred to as white coal for its power and plenty. Hoover Dams initial 1,345 MW power station was the worlds largest hydroelectric station in 1936
In electronics, a crossbar switch is a collection of switches arranged in a matrix configuration. Originally, a crossbar switch consisted literally of crossing metal bars that provided the input and output paths, implementations achieved the same switching topology in solid state semiconductor chips. The cross-point switch is one of the principal switch architectures, together with a switch, memory switch. A crossbar switch is an assembly of individual switches between a set of inputs and a set of outputs, the switches are arranged in a matrix. If the crossbar switch has M inputs and N outputs, a crossbar has a matrix with M × N cross-points or places where the connections cross, at each crosspoint is a switch, when closed, it connects one of the inputs to one of the outputs. A given crossbar is a layer, non-blocking switch. Non-blocking means that other concurrent connections do not prevent connecting other inputs to other outputs, collections of crossbars can be used to implement multiple layer and blocking switches. A crossbar switching system is called a coordinate switching system.
Crossbar switches are used in information processing applications such as telephony and circuit switching. The matrix layout of a switch is used in some semiconductor memory devices. Here the bars are thin metal wires, and the switches are fusible links. The fuses are blown or opened using high voltage and read using low voltage, such devices are called programmable read-only memory. At the 2008 NSTI Nanotechnology Conference a paper was presented which discussed a nanoscale crossbar implementation of an adding circuit used as an alternative to logic gates for computation, matrix arrays are fundamental to modern flat-panel displays. Thin-film-transistor LCDs have a transistor at each crosspoint, so they could be considered to include a switch as part of their structure. In a typical installation, all the sources are located on an equipment rack. Where central control of the matrix is practical, a typical rack-mount matrix switch offers front-panel buttons to allow connection of inputs to outputs.
An example of such a usage might be a sports bar, ordinarily, a sports bar would install a separate desk top box for each display for which independent control is desired. Such switches are used in home theater applications
A valve actuator is the mechanism for opening and closing a valve. Manually operated valves require someone in attendance to adjust them using a direct or geared mechanism attached to the valve stem, power-operated actuators, using gas pressure, hydraulic pressure or electricity, allow a valve to be adjusted remotely, or allow rapid operation of large valves. Power-operated valve actuators may be the elements of an automatic control loop which automatically regulates some flow. Actuators may be only to open and close the valve, or may allow intermediate positioning, used for the automation of industrial valves, actuators can be found in all kinds of process plants. They are used in water treatment plants, power plants, refineries and nuclear processes, food factories. Valve actuators play a part in automating process control. The valves to be automated vary both in design and dimension, the diameters of the valves range from one-tenth of a inch to several feet. There are four types of actuators, pneumatic, hydraulic. A manual actuator employs levers, gears, or wheels to move the valve stem, manual actuators are powered by hand.
Manual actuators are inexpensive, typically self-contained and easy to operate, some large valves are impossible to operate manually and some valves may be located in remote, toxic or hostile environments that prevent manual operations. As a safety feature, certain types of situations may require quicker operation than manual actuators can provide to close the valve, air pressure is the power source for pneumatic valve actuators. They are used on linear or quarter-turn valves, air pressure acts on a piston or bellows diaphragm creating linear force on a valve stem. Alternatively, a quarter-turn vane-type actuator produces torque to provide motion to operate a quarter-turn valve. A pneumatic actuator may be arranged to be spring-closed or spring-opened, a double acting actuator use air applied to different inlets to move the valve in the opening or closing direction. A central compressed air system can provide the clean, dry, in some types, for example, regulators for compressed gas, the supply pressure is provided from the process gas stream and waste gas either vented to air or dumped into lower-pressure process piping.
Hydraulic actuators convert fluid pressure into motion, similar to pneumatic actuators, they are used on linear or quarter-turn valves. Fluid pressure acting on a piston provides linear thrust for gate or globe valves, a quarter-turn actuator produces torque to provide rotary motion to operate a quarter-turn valve. Most types of hydraulic actuators can be supplied with fail-safe features to close or open a valve under emergency circumstances, hydraulic pressure can be supplied by a self-contained hydraulic pressure pump
Michigan Technological University
Michigan Technological University is a public research university located in Houghton, United States. Its main campus sits on 925 acres on a bluff overlooking Portage Lake, Michigan Tech was founded in 1885 as the first post-secondary institution in the Upper Peninsula of Michigan, and was created to train mining engineers to operate the local copper mines. Science, technology and business have been added to the engineering disciplines. US News and World Report ranked Michigan Techs undergraduate program 116th in the based on peer assessment, student selectivity, financial resources. Michigan Tech was rated among the Best in the Midwest by The Princeton Review, Michigan Techs athletic teams are nicknamed the Huskies and compete primarily in the NCAA Division II Great Lakes Intercollegiate Athletic Conference. The mens hockey team competes in Division I as a member of the Western Collegiate Hockey Association, the womens basketball team were national runners-up in 2011. Michigan Tech was founded in 1885 as the Michigan Mining School, after much agitation by Jay Abel Hubbell, the state legislature established the school to train mining engineers.
Hubbell donated land for the schools first buildings, the school started with four faculty members and twenty-three students. It was housed in the Houghton Fire Hall from 1886 through 1889, a few years after the schools creation, enrollment grew to such a point that its name no longer reflected its purpose. The name was changed to the Michigan College of Mines in 1897. By 1931 enrollment had reached nearly 600, during the next few years, due to the Great Depression, money was scarce, causing department heads and even the president of the university, William Hotchkiss, to take pay cuts. Dillman was president from 1935 to 1956, during this time, the school underwent many notable changes, including the construction of the Memorial Union Building and purchase of an ice rink and golf course. Around 1948, enrollment passed 2000 students total, in 1956, J. Robert Van Pelt became the new president of the university. He restarted many PhD programs and created a focus on research and this included the schools first analog computation class in 1956–1957.
In the final years of his presidency, the changed from a college to a university. The change from the Michigan College of Mining and Technology was necessary for two reasons, according to Van Pelt, the college had expanded too greatly and the current name was no longer an accurate title. Also, including mining in the name of the college was misleading, the name Michigan Technological University was chosen in order to retain the nickname Michigan Tech that had already been in use since 1927. Although engineering still accounts for some 59 percent of all enrollment as of fall 2010, along with its new name, the school gained new constitutional status in 1964
A computer program is a collection of instructions that performs a specific task when executed by a computer. A computer requires programs to function, and typically executes the programs instructions in a processing unit. A computer program is written by a computer programmer in a programming language. From the program in its form of source code, a compiler can derive machine code—a form consisting of instructions that the computer can directly execute. Alternatively, a program may be executed with the aid of an interpreter. A part of a program that performs a well-defined task is known as an algorithm. A collection of programs and related data are referred to as software. Computer programs may be categorized along functional lines, such as software or system software. The earliest programmable machines preceded the invention of the digital computer, in 1801, Joseph-Marie Jacquard devised a loom that would weave a pattern by following a series of perforated cards. Patterns could be weaved and repeated by arranging the cards, in 1837, Charles Babbage was inspired by Jacquards loom to attempt to build the Analytical Engine.
The names of the components of the device were borrowed from the textile industry. In the textile industry, yarn was brought from the store to be milled, the device would have had a store—memory to hold 1,000 numbers of 40 decimal digits each. Numbers from the store would have transferred to the mill. It was programmed using two sets of perforated cards—one to direct the operation and the other for the input variables, after more than 17,000 pounds of the British governments money, the thousands of cogged wheels and gears never fully worked together. During a nine-month period in 1842–43, Ada Lovelace translated the memoir of Italian mathematician Luigi Menabrea, the memoir covered the Analytical Engine. The translation contained Note G which completely detailed a method for calculating Bernoulli numbers using the Analytical Engine and this note is recognized by some historians as the worlds first written computer program. In 1936, Alan Turing introduced the Universal Turing machine—a theoretical device that can model every computation that can be performed on a Turing complete computing machine and it is a finite-state machine that has an infinitely long read/write tape.
The machine can move the back and forth, changing its contents as it performs an algorithm
Telegraphy is the long-distance transmission of textual or symbolic messages without the physical exchange of an object bearing the message. Thus semaphore is a method of telegraphy, whereas pigeon post is not, telegraphy requires that the method used for encoding the message be known to both sender and receiver. Such methods are designed according to the limits of the medium used. The use of signals, reflected light signals. In the 19th century, the harnessing of electricity led to the invention of electrical telegraphy, the advent of radio in the early 20th century brought about radiotelegraphy and other forms of wireless telegraphy. The word telegraph was first coined by the French inventor of the Semaphore line, Claude Chappe, a telegraph is a device for transmitting and receiving messages over long distances, i. e. for telegraphy. The word telegraph alone now generally refers to an electrical telegraph, Wireless telegraphy is known as CW, for continuous wave, as opposed to the earlier radio technique of using a spark gap.
Contrary to the definition used by Chappe, Morse argued that the term telegraph can strictly be applied only to systems that transmit. This is to be distinguished from semaphore, which transmits messages. Smoke signals, for instance, are to be considered semaphore, according to Morse, telegraph dates only from 1832 when Pavel Schilling invented one of the earliest electrical telegraphs. A telegraph message sent by a telegraph operator or telegrapher using Morse code was known as a telegram. A cablegram was a sent by a submarine telegraph cable. Later, a Telex was a sent by a Telex network. A wire picture or wire photo was a picture that was sent from a remote location by a facsimile telegraph. A diplomatic telegram, known as a cable, is the term given to a confidential communication between a diplomatic mission and the foreign ministry of its parent country. These continue to be called telegrams or cables regardless of the used for transmission. Commercial electrical telegraphs were introduced from 1837, the first telegraphs came in the form of optical telegraph, including the use of smoke signals, beacons, or reflected light, which have existed since ancient times.
Early proposals for a telegraph system were made to the Royal Society by Robert Hooke in 1684 and were first implemented on an experimental level by Sir Richard Lovell Edgeworth in 1767