1.
Plastic film
–
Plastic film is a thin continuous polymeric material. Thicker plastic material is called a “sheet”. These thin plastic membranes are used to separate areas or volumes, to items, to act as barriers. Plastic films are used in a variety of applications. These include, packaging, plastic bags, labels, building construction, landscaping, electrical fabrication, photographic film, film stock for movies, video tape, almost all plastics can be formed into a thin film. Polypropylene – Polypropylene can be made a cast film, biaxially oriented film, polyester – BoPET is a biaxially oriented polyester film Nylon Polyvinyl chloride – film can be with or without a Plasticizer A variety of bioplastics and biodegradable plastics are available. Cast – Plastics extrusion can cast film which is cooled or quenched then wound up on a roll, extruded film can be stretched, thinned, or oriented in one or two directions. Blown or tubular process forces air into a ring to expand the film. Flat tenter lines stretch the extruded film before annealing, calender rolls can be used to form film from hot polymers Solution deposition is another film forming process. Often additional coating or printing operations are also used, Films can be modified by physical vapor deposition to make metallised films. Films can be subjected to treatment or Plasma processing, films can have release agents applied as needed. Plastic Films, Technology and Packaging Applications, CRC Press 1992 Yam, K. L. Encyclopedia of Packaging Technology, John Wiley & Sons,2009, ISBN 978-0-470-08704-6
2.
Wire recording
–
Wire recording or magnetic wire recording was the first early magnetic recording technology, an analog type of audio storage in which a magnetic recording is made on thin steel wire. The first crude magnetic recorder was invented in 1898 by Valdemar Poulsen, the principles and electronics involved are nearly identical. The first wire recorder was invented in 1898 by Danish-American engineer Valdemar Poulsen, Wire recorders for dictation and telephone recording were made almost continuously by various companies through the 1920s and 1930s, but use of this new technology was extremely limited. Dictaphone and Ediphone recorders, which still employed wax cylinders as the medium, were the devices normally used for these applications during this period. The brief heyday of wire recording lasted from approximately 1946 to 1954, the two organizations licensed dozens of manufacturers in the U. S. Japan, and Europe. Examples are Wilcox-Gay, Pierce, Webcor, and Air King, the popularity even encouraged Sears to provide a model, and some authors to prepare specialized manuals. The earliest magnetic tape recorders, not commercially available in the U. S. until 1948, were too expensive, complicated, for any given level of audio quality, the nearly hair-thin wire had the advantage that it was a much more compact storage medium than tape. The Minifon wire recorder was designed for use and its accessories included a microphone disguised as a wristwatch. There were also wire recorders made to data in satellites. Poulsens original telegraphone and other very early recorders placed the two poles of the head on opposite sides of the wire. The wire is thus magnetised transversely to the direction of travel, the development was to place the two poles on the same side of the wire so that the wire was magnetised along its length or longitudinally. Additionally, the poles were shaped into a V so that the head wrapped around the wire to some extent and this increased the magnetising effect and also increased the sensitivity of the head on replay because it collected more of the magnetic flux from the wire. This system was not entirely immune to twisting but the effects were far less marked, the longitudinal method survives into magnetic tape recording to this day. Compared to tape recorders, wire recording devices have a high media speed, standard postwar wire recorders use a nominal speed of 24 inches per second, making a typical one-hour spool of wire 7,200 feet long. Smaller 30- and 15-minute lengths of wire were employed by the majority of recorders made after 1945, some heavy-duty recorders use the larger Armour spools, which can contain enough wire to record continuously for several hours. Because the wire is pulled past the head by the take-up spool, to facilitate handling as the user threaded the wire across the recording head and affixed it to the take-up spool, some manufacturers attached a strip of plastic to each end of the wire. This was designed to press-fit snugly into either spool, on some machines, moving wire guides perform this function, like the mechanism that distributes line across a fishing reel. After recording or playback, the wire has to be rewound before any further use can be made of the machine, unlike with reel-to-reel tape recorders, the take-up reel on most wire recorders is not removable
3.
Tape recorder
–
In its present-day form, it records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Tape-recording devices include reel-to-reel tape deck and the cassette deck, the use of magnetic tape for sound recording originated around 1930. Magnetizable tape revolutionized both the radio broadcast and music recording industries and it gave artists and producers the power to record and re-record audio with minimal loss in quality as well as edit and rearrange recordings with ease. The alternative recording technologies of the era, transcription discs and wire recorders, since some early refinements improved the fidelity of the reproduced sound, magnetic tape has been the highest quality analog sound recording medium available. As of the first decade of the 21st century, analog magnetic tape has been replaced by digital recording technologies for consumer purposes. Some individuals and organizations developed innovative uses for magnetic wire recorders while others investigated variations of the technology, one particularly important variation was the application of an oxide powder to a long strip of paper. This German invention was the start of a string of innovations that have led to present day magnetic tape recordings. The earliest known audio tape recorder was a non-magnetic, non-electric version invented by Alexander Graham Bells Volta Laboratory and patented in 1886. It employed a 3⁄16-inch-wide strip of wax-covered paper that was coated by dipping it in a solution of beeswax and paraffin and then had one side scraped clean, the machine was of sturdy wood and metal construction, and hand-powered by means of a knob fastened to the flywheel. The tape was taken up on the other reel. The sharp recording stylus, actuated by a vibrating mica diaphragm, in playback mode, a dull, loosely mounted stylus, attached to a rubber diaphragm, carried the reproduced sounds through an ear tube to its listener. Both recording and playback heads, mounted alternately on the two posts, could be adjusted vertically so that several recordings could be cut on the same 3⁄16-inch-wide strip. While the machine was never developed commercially, it was an ancestor to the modern magnetic tape recorder which it resembled somewhat in design. The tapes and machine created by Bells associates, examined at one of the Smithsonian Institutions museums, became brittle, the machines playback head was also missing. Otherwise, with some reconditioning, they could be placed into working condition, during the recording process, the tape moved through a pair of electrodes which immediately imprinted the modulated sound signals as visible black stripes into the paper tapes surface. On 13 August 1931, Duston filed USPTO Patent Application #556,743 for Method Of And Apparatus For Electrically Recording And Reproducing Sound And Other Vibrations, and which was renewed in 1934. Magnetic recording was conceived as early as 1877 by the American engineer Oberlin Smith, Analog magnetic wire recording, and its successor, magnetic tape recording, involve the use of a magnetizable medium which moves with a constant speed past a recording head. An electrical signal, which is analogous to the sound that is to be recorded, is fed to the recording head, inducing a pattern of magnetization similar to the signal
4.
Video tape recorder
–
A video tape recorder is a tape recorder designed to record video material on magnetic tape. The first practical tape recorder, using transverse tape head scanning, was developed by Ampex Corporation in 1956. The early VTRs were reel to reel devices which recorded on reels of 2 inch wide magnetic tape. They were used in studios, serving as a replacement for motion picture film stock. Beginning in 1963, videotape machines made instant replay during televised sporting events possible, improved formats, in which the tape was contained inside a videocassette, were introduced around 1969, the machines which play them are called videocassette recorders. The first efforts at recording, using recorders similar to audio recorders with fixed heads, were unsuccessful. The problem was that a signal has a much wider bandwidth than an audio signal. One of the first efforts was the Vision Electronic Recording Apparatus and this machine used a thin steel tape on a 21-inch reel traveling at over 200 inches per second. Despite 10 years of research and improvements, it was never used due to the immense length of tape required for each minute of recorded video. Many other fixed-head recording systems were tried but all required impractically high tape speed and it became clear that practical video recording technology depended on finding some way of recording the wide-bandwidth video signal without the high tape speed required by linear-scan machines. The Ampex VRX-1000 became the worlds first commercially successful videotape recorder in 1956 and it used the 2 Quadruplex format, using two-inch tape. Because of its US$50,000 price, the Ampex VRX-1000 could be afforded only by the television networks and the largest individual stations. In 1963, Philips introduced its EL34001 helical scan recorder and Sony marketed the 2 PV-100, its first reel-to-reel VTR intended for business, medical, airline and educational use. The Telcan, produced by the Nottingham Electronic Valve Company and demonstrated on June 24,1963, was the first home video recorder and it could be bought as a unit or in kit form for £60. However, there were drawbacks, it was expensive, not easy to put together. The Sony model CV-2000, first marketed in 1965, was its first VTR intended for use and was based on half-inch tape. Ampex and RCA followed in 1965 with its own reel-to-reel monochrome VTRs priced under US $1,000 for the consumer market. Prerecorded movies for home replay became available in 1967, the EIAJ format was a standard half-inch format used by various manufacturers
5.
Tape drive
–
A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic tape data storage is used for offline, archival data storage. Tape media generally has a unit cost and a long archival stability. A tape drive provides sequential access storage, unlike a hard disk drive, a disk drive can move to any position on the disk in a few milliseconds, but a tape drive must physically wind tape between reels to read any one particular piece of data. As a result, tape drives have very slow average seek times to data, however, tape drives can stream data very quickly off a tape when the required position has been reached. For example, as of 2010 Linear Tape-Open supported continuous data transfer rates of up to 140 MB/s, magnetic tape drives were first used for data storage on mainframe computers in the 1950s, with capacities less than one megabyte. As technology advanced, capacities increased to 10 terabytes or higher of uncompressed data per cartridge as of 2014, in early computer systems, magnetic tape might be the main storage medium, although the drives were expensive, the tapes were inexpensive. The true storage capacity is known as the native capacity or the raw capacity. IBM and Sony have also used higher compression ratios in their marketing materials, the compression ratio actually achievable depends on the data being compressed. Some data has little redundancy, large files, for example, already use compression technology. A sparse database, on the hand, may allow compression ratios better than 10,1. Tape drives can be connected to a computer with SCSI, Fibre Channel, SATA, USB, FireWire, FICON, or other interfaces. Tape drives are used with autoloaders and tape libraries which automatically load, unload, in the early days of home computing, floppy and hard disk drives were very expensive. Many computers had an interface to store data via a tape recorder. Simple dedicated tape drives, such as the professional DECtape and the home ZX Microdrive, however, the drop in disk drive prices made such alternatives obsolete. In this situation, the modern fast-running tape drive is unable to stop the tape instantly, instead, the drive must decelerate and stop the tape, rewind it a short distance, restart it, position back to the point at which streaming stopped and then resume the operation. If the condition repeats, the resulting back-and-forth tape motion resembles that of shining shoes with a cloth, shoe-shining decreases the attainable data transfer rate, drive and tape life, and tape capacity. In early tape drives, non-continuous data transfer was normal and unavoidable, computer processing power and amounts of available memory were usually insufficient to provide a constant stream, so tape drives were typically designed for so called start-stop operation
6.
Sound recording and reproduction
–
Sound recording and reproduction is an electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording, prior to the development of analog recording, there were mechanical systems for reproducing instrumental music, such as wind-up music boxes and later, in the late 19th century, player pianos. Analog sound reproduction is the process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Digital recording and reproduction converts the sound signal picked up by the microphone to a digital form by the process of digitization. This lets the audio data be stored and transmitted by a variety of media. Whereas successive copies of an analog recording tend to degrade in quality, as noise is added. A digital audio signal must be reconverted to analog form during playback before it is amplified and connected to a loudspeaker to produce sound, long before sound was first recorded on cylinders or records, music was recorded—first by written music notation, then also by mechanical devices. Fowler, this. cylinder with raised pins on the surface remained the device to produce and reproduce music mechanically until the second half of the nineteenth century. The Banu Musa brothers also invented an automatic flute player, which appears to have been the first programmable machine, according to Fowler, the automata were a robot band that performed. more than fifty facial and body actions during each musical selection. In the 14th century, Flanders introduced a mechanical bell-ringer controlled by a rotating cylinder, similar designs appeared in barrel organs, musical clocks, barrel pianos, and musical boxes. A music box is a musical instrument that produces sounds by the use of a set of pins placed on a revolving cylinder or disc so as to pluck the tuned teeth of a steel comb. They were developed from musical snuff boxes of the 18th century, some of the more complex boxes also have a tiny drum and/or bells, in addition to the metal comb. The fairground organ, developed in 1892, used a system of accordion-folded punched cardboard books, the player piano, first demonstrated in 1876, used a punched paper scroll that could store an long piece of music. The most sophisticated of the rolls were hand-played, meaning that the roll represented the actual performance of an individual. This technology to record a live performance onto a piano roll was not developed until 1904, piano rolls were in continuous mass production from 1896 to 2008. A1908 U. S. Supreme Court copyright case noted that, in 1902 alone, the use of piano rolls began to decline in the 1920s although one type is still being made today. The first device that could record actual sounds as they passed through the air was the phonautograph, the earliest known recordings of the human voice are phonautograph recordings, called phonautograms, made in 1857. They consist of sheets of paper with sound-wave-modulated white lines created by a stylus that cut through a coating of soot as the paper was passed under it
7.
Broadcasting
–
Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, all forms of communication were one-to-one, with the message intended for a single recipient. Over the air broadcasting is usually associated with radio and television, the receiving parties may include the general public or a relatively small subset, the point is that anyone with the appropriate receiving technology and equipment can receive the signal. The field of broadcasting includes both government-managed services such as radio, community radio and public television, and private commercial radio. The U. S. Code of Federal Regulations, title 47, part 97 defines broadcasting as transmissions intended for reception by the general public, private or two-way telecommunications transmissions do not qualify under this definition. For example, amateur and citizens band radio operators are not allowed to broadcast, as defined, transmitting and broadcasting are not the same. Transmissions using a wire or cable, like television, are also considered broadcasts. In the 2000s, transmissions of television and radio programs via streaming digital technology have increasingly been referred to as broadcasting as well, the earliest broadcasting consisted of sending telegraph signals over the airwaves, using Morse code, a system developed in the 1830s by Samuel F. B. Morse, physicist Joseph Henry and Alfred Vail and they developed an electrical telegraph system which sent pulses of electric current along wires which controlled an electromagnet that was located at the receiving end of the telegraph system. A code was needed to transmit natural language using only these pulses, Morse therefore developed the forerunner to modern International Morse code. Audio broadcasting began experimentally in the first decade of the 20th century, by the early 1920s radio broadcasting became a household medium, at first on the AM band and later on FM. Television broadcasting started experimentally in the 1920s and became widespread after World War II, satellite broadcasting was initiated in the 1960s and moved into general industry usage in the 1970s, with DBS emerging in the 1980s. Originally all broadcasting was composed of signals using analog transmission techniques but in the 2000s. In general usage, broadcasting most frequently refers to the transmission of information, Analog audio vs. HD Radio Analog television vs.9 zettabytes. This is the equivalent of 55 newspapers per person per day in 1986. Historically, there have been several methods used for broadcasting electronic media audio and/or video to the public, Telephone broadcasting. Telephone broadcasting also grew to include telephone services for news and entertainment programming which were introduced in the 1890s. These telephone-based subscription services were the first examples of electrical/electronic broadcasting, Radio broadcasting, audio signals sent through the air as radio waves from a transmitter, picked up by an antenna and sent to a receiver
8.
Radio
–
When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form, Radio systems need a transmitter to modulate some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation. Radio systems also need an antenna to convert electric currents into radio waves, an antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected, the electromagnetic wave is intercepted by a tuned receiving antenna. Radio frequencies occupy the range from a 3 kHz to 300 GHz, a radio communication system sends signals by radio. The term radio is derived from the Latin word radius, meaning spoke of a wheel, beam of light, however, this invention would not be widely adopted. The switch to radio in place of wireless took place slowly and unevenly in the English-speaking world, the United States Navy would also play a role. Although its translation of the 1906 Berlin Convention used the terms wireless telegraph and wireless telegram, the term started to become preferred by the general public in the 1920s with the introduction of broadcasting. Radio systems used for communication have the following elements, with more than 100 years of development, each process is implemented by a wide range of methods, specialised for different communications purposes. Each system contains a transmitter, This consists of a source of electrical energy, the transmitter contains a system to modulate some property of the energy produced to impress a signal on it. This modulation might be as simple as turning the energy on and off, or altering more subtle such as amplitude, frequency, phase. Amplitude modulation of a carrier wave works by varying the strength of the signal in proportion to the information being sent. For example, changes in the strength can be used to reflect the sounds to be reproduced by a speaker. It was the used for the first audio radio transmissions. Frequency modulation varies the frequency of the carrier, the instantaneous frequency of the carrier is directly proportional to the instantaneous value of the input signal. FM has the capture effect whereby a receiver only receives the strongest signal, Digital data can be sent by shifting the carriers frequency among a set of discrete values, a technique known as frequency-shift keying. FM is commonly used at Very high frequency radio frequencies for high-fidelity broadcasts of music, analog TV sound is also broadcast using FM. Angle modulation alters the phase of the carrier wave to transmit a signal
9.
Phonograph record
–
The groove usually starts near the periphery and ends near the center of the disc. The phonograph disc record was the medium used for music reproduction until late in the 20th century. It had co-existed with the cylinder from the late 1880s. Records retained the largest market share even when new formats such as compact cassette were mass-marketed, by the late 1980s, digital media, in the form of the compact disc, had gained a larger market share, and the vinyl record left the mainstream in 1991. The phonograph record has made a resurgence in the early 21st century –9.2 million records were sold in the U. S. in 2014. Likewise, in the UK sales have increased five-fold from 2009 to 2014, as of 2017,48 record pressing facilities remain worldwide,18 in the United States and 30 in other countries. The increased popularity of vinyl has led to the investment in new, only two producers of lacquers remains, Apollo Masters in California, USA, and MDC in Japan. Vinyl records may be scratched or warped if stored incorrectly but if they are not exposed to heat or broken. The large cover are valued by collectors and artists for the space given for visual expression, in the 2000s, these tracings were first scanned by audio engineers and digitally converted into audible sound. Phonautograms of singing and speech made by Scott in 1860 were played back as sound for the first time in 2008, along with a tuning fork tone and unintelligible snippets recorded as early as 1857, these are the earliest known recordings of sound. In 1877, Thomas Edison invented the phonograph, unlike the phonautograph, it was capable of both recording and reproducing sound. Despite the similarity of name, there is no evidence that Edisons phonograph was based on Scotts phonautograph. Edison first tried recording sound on a paper tape, with the idea of creating a telephone repeater analogous to the telegraph repeater he had been working on. The tinfoil was wrapped around a metal cylinder and a sound-vibrated stylus indented the tinfoil while the cylinder was rotated. The recording could be played back immediately, Edison also invented variations of the phonograph that used tape and disc formats. A decade later, Edison developed a greatly improved phonograph that used a wax cylinder instead of a foil sheet. This proved to be both a better-sounding and far more useful and durable device, the wax phonograph cylinder created the recorded sound market at the end of the 1880s and dominated it through the early years of the 20th century. Berliners earliest discs, first marketed in 1889, but only in Europe, were 12.5 cm in diameter, both the records and the machine were adequate only for use as a toy or curiosity, due to the limited sound quality
