Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to light, which is visible to the human eye and is responsible for the sense of sight. Visible light is defined as having wavelengths in the range of 400–700 nanometres, or 4.00 × 10−7 to 7.00 × 10−7 m. This wavelength means a range of roughly 430–750 terahertz. The main source of light on Earth is the Sun, sunlight provides the energy that green plants use to create sugars mostly in the form of starches, which release energy into the living things that digest them. This process of photosynthesis provides virtually all the used by living things. Historically, another important source of light for humans has been fire, with the development of electric lights and power systems, electric lighting has effectively replaced firelight. Some species of animals generate their own light, a process called bioluminescence, for example, fireflies use light to locate mates, and vampire squids use it to hide themselves from prey.
Visible light, as all types of electromagnetic radiation, is experimentally found to always move at this speed in a vacuum. In physics, the term sometimes refers to electromagnetic radiation of any wavelength. In this sense, gamma rays, X-rays and radio waves are light, like all types of light, visible light is emitted and absorbed in tiny packets called photons and exhibits properties of both waves and particles. This property is referred to as the wave–particle duality, the study of light, known as optics, is an important research area in modern physics. Generally, EM radiation, or EMR, is classified by wavelength into radio, infrared, the behavior of EMR depends on its wavelength. Higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths, when EMR interacts with single atoms and molecules, its behavior depends on the amount of energy per quantum it carries. There exist animals that are sensitive to various types of infrared, infrared sensing in snakes depends on a kind of natural thermal imaging, in which tiny packets of cellular water are raised in temperature by the infrared radiation. EMR in this range causes molecular vibration and heating effects, which is how these animals detect it, above the range of visible light, ultraviolet light becomes invisible to humans, mostly because it is absorbed by the cornea below 360 nanometers and the internal lens below 400.
Furthermore, the rods and cones located in the retina of the eye cannot detect the very short ultraviolet wavelengths and are in fact damaged by ultraviolet. Many animals with eyes that do not require lenses are able to detect ultraviolet, by quantum photon-absorption mechanisms, various sources define visible light as narrowly as 420 to 680 to as broadly as 380 to 800 nm
History of paper
Paper is a wood like material primarily used for writing, first invented in ancient China. Although contemporary precursors such as papyrus and amate existed in the Mediterranean world and pre-Columbian Americas, the first papermaking process was documented in China during the Eastern Han period, traditionally attributed to the court official Cai Lun. During the 8th century Chinese papermaking spread to the Islamic world, by the 11th century papermaking was brought to medieval Europe, where it was refined with the earliest known paper mills utilizing waterwheels. Later Western improvements to the process came in the 19th century with the invention of wood-based papers. The word paper is etymologically derived from papyrus, Ancient Greek for the Cyperus papyrus plant, papyrus however are plants pressed and dried, while paper is made from fibers whose properties have been changed by maceration or disintegration. In the pre-Columbian Americas, a type of bark paper known as amate was used as a folded writing material for codices.
The earliest sample of amate was found at Huitzilapa near the Magdalena Municipality, Mexico, by the 16th century the Spanish introduced papermaking to the Americas. However, the earliest piece of found, at Fangmatan in Gansu province inscribed with a map. During the Shang and Zhou dynasties of ancient China, documents were written on bone or bamboo, making them very heavy, awkward. The light material of silk was used as a recording medium. The Han dynasty Chinese court official Cai Lun is widely regarded as the inventor of the method of papermaking from rags. It therefore would appear that Cai Luns contribution was to improve this skill systematically and scientifically, the record in the Twenty-Four Histories says In ancient times writings and inscriptions were generally made on tablets of bamboo or on pieces of silk called chih. But silk being costly and bamboos heavy they were not convenient to use, Tshai Lun initiated the idea of making paper from the bark of trees, remnants of hemp, rags of cloth and fishing nets.
He submitted the process to the emperor in the first year of Yuan-Hsing, from this time, paper has been in use everywhere and is universally called the paper of Marquis Tshai. The manufacture may have originated from the practice of pounding and stirring rags in water, after which the fibres were collected on a mat. The bark of Paper Mulberry was particularly valued and high quality paper was developed in the late Han period, in the Eastern Jin period, paper began to be made on a fine bamboo screen-mould, treated with insecticidal dye for permanence. After printing became popular in the Song dynasty the demand grew more, Paper was often used as a levy, with one prefecture sending some 1.5 million sheets of paper to the capital as tribute up to the year 1101. The first use of paper has been excavated in China dating to the reign of Emperor Wu of Han from the 2nd century BC and it was used for safety, such as the padding of poisonous medicine as mentioned in the official history of the period
A digital watermark is a kind of marker covertly embedded in a noise-tolerant signal such as an audio, video or image data. It is typically used to identify ownership of the copyright of such signal, watermarking is the process of hiding digital information in a carrier signal, the hidden information should, but does not need to, contain a relation to the carrier signal. Digital watermarks may be used to verify the authenticity or integrity of the signal or to show the identity of its owners. It is prominently used for tracing copyright infringements and for banknote authentication, like traditional physical watermarks, digital watermarks are often only perceptible under certain conditions, i. e. after using some algorithm. If a digital watermark distorts the signal in a way that it becomes easily perceivable. Traditional watermarks may be applied to media, whereas in digital watermarking. A signal may carry several different watermarks at the same time, unlike metadata that is added to the carrier signal, a digital watermark does not change the size of the carrier signal.
The needed properties of a digital watermark depend on the use case in which it is applied, for marking media files with copyright information, a digital watermark has to be rather robust against modifications that can be applied to the carrier signal. Instead, if integrity has to be ensured, a fragile watermark would be applied, both steganography and digital watermarking employ steganographic techniques to embed data covertly in noisy signals. But whereas steganography aims for imperceptibility to human senses, digital watermarking tries to control the robustness as top priority, since a digital copy of data is the same as the original, digital watermarking is a passive protection tool. It just marks data, but does not degrade it or control access to the data, one application of digital watermarking is source tracking. A watermark is embedded into a signal at each point of distribution. If a copy of the work is later, the watermark may be retrieved from the copy. This technique reportedly has been used to detect the source of illegally copied movies, the term Digital Watermark was coined by Andrew Tirkel and Charles Osborne in December 1992.
The first successful embedding and extraction of a spread spectrum watermark was demonstrated in 1993 by Andrew Tirkel, Charles Osborne. Watermarks are identification marks produced during the making process. The first watermarks appeared in Italy during the 13th century, and they were used as a means to identify the papermaker or the trade guild that manufactured the paper. The marks often were created by a wire sewn onto the paper mold, watermarks continue to be used today as manufacturers marks and to prevent forgery
Postage stamp paper
Postage stamp paper is the foundation or substrate of the postage stamp to which the ink for the stamps design is applied to one side and the adhesive is applied to the other. Stamp catalogs like Scotts Standard Postage Stamp Catalog often document the paper the stamp is printed on to describe a stamps classification, the same stamp design can appear on several kinds of paper. Certain paper types may require the services of an expert as the only way of knowing the true identity of the stamps paper. All paper is endowed with certain characteristics by its maker, depending on the purpose of the paper, the craftsman will choose specific materials and apply certain manufacturing processes to achieve the design objectives. Characteristics such as composition, color, watermark, surface finish, hardness, from a philatelic interest, it is the second phase, the forming of the paper that yields the most interesting characteristics. In the first phase of papermaking the characteristics such as its composition, Paper has as its chief component, a mat of cellulose fibers.
Cellulose is the structure of plant cells and can be separated from the plant for use in paper. Cellulose has several characteristics that make it desirable for paper, the foremost being its strength when formed into a mat or web, when cellulose fibers come in contact with each other in water, a bond is formed. When water is removed from the fibers, the bond between the fibers strengthens. Pulp, the collection of fibers, may be bleached. Since most paper is printed or written upon, fillers are added to the pulp to fill the pores of the paper and sizing is added to make the fibers water resistant. Unsized paper is blotting paper, making it unsuitable for printing and sizing are added to the pulp to absorb the ink quickly, unlike pure cellulose. Fillers can be made from animal products, starches from rice or wheat, resins or gums, or minerals such as calcium carbonate. Mineral fillers are the most common as they are effective as a filler. When all of these ingredients are assembled, they are suspended in water, the paper is formed in the second stage of papermaking.
With handmade paper, the furnish is stored in a vat, the mould determines the dimensions of the finished sheet and its weight, which ultimately establishes the paper’s thickness. The mould is usually a mesh that acts as a strainer such that the furnish is separated out of the water. The water drains off, leaving layers upon layers of fibers or a web of paper on the mould, the texture of the paper is determined by the nature of the mould
Fabriano is a town and comune of Ancona province in the Italian region of the Marche, at 325 metres above sea level. It lies in the Esino valley 44 kilometres upstream and southwest of Jesi and its location on the main highway and rail line from Umbria to the Adriatic make it a mid-sized regional center in the Apennines. Fabriano is the headquarters of the giant appliance maker Indesit, with Bologna, is the only Italian creative city. The town is in the category Folk Arts, Fabriano appears to have been founded in the early Middle Ages by the inhabitants of a small Roman town 5 kilometres south at Attiggio, of which some slight remains and inscriptions are extant. Fabrianos wealth and commitment to the arts in the late medieval period have left it with many monuments. Fabriano Cathedral, dedicated to San Venanzio, from the Baroque restoration are the stucco decoration of the interior and the canvasses by Gregorio Preti, Salvator Rosa, Giovanni Francesco Guerrieri, Giuseppe Puglia and Orazio Gentileschi.
To the original Cathedral belong the polygonal apse, the cloister, important are the frescoes with Stories of the True Cross by the Folignate painter Giovanni di Corraduccio. Nicholas Santa Maria del Piangato St Benedict Oratory of the Gonfalone Palazzo del Podestà built in stone from Vallemontagnana. It has a bridge structure, a memory of the stream which once flowed under it. The central arcade has frescoes from the 13th-14th centuries portraying warriors, sturinalto Fountain, designed by Jacopo di Grondolo, who was inspired by the Fontana Maggiore in Perugia. It was the residence of the Chiavelli family, lords of the city until 1435, in the courtyard is a lapidarium with fragments of buildings of the ancient Roman cities of Attidium and Sentinum. Pinacoteca Civica Bruno Malajoli displayed in the former Hospital - The hospital was first built in 1456, the art collection of the Pinacoteca were moved here in 1994. Loggiato of St. Saint John dal Bastone 12th-century Silvestrine monk, jessica Rizzo, an actress and businesswoman.
Fabriano official website Museo della Carta Fabriano Storica - history, culture, curiosity Bill Thayers site Made in Fabriano Academy
A window screen is designed to cover the opening of a window. It is usually a mesh made of wire, fiberglass, or other synthetic fiber. It serves to keep leaves, insects, most houses in Australia, the United States and Canada and other parts of the world have screens on the window to prevent entry of flying insects such as mosquitoes and wasps. Wove wire for window screens were referenced in the American Farmer in 1823, advertisement for wire window screens appeared in Boyds Blue Book in 1836. Two wire window screens were exhibited at Quincy Hall in Boston in 1839, in 1861 Gilberr and Company was manufacturing wire mesh sieves for food processing. An employee realized that the wire cloth could be painted gray and sold as window screens, by 1874, E. T. Barnum Company of Detroit, Michigan advertised screens that were sold by the square foot. By the 1950s, parasitic diseases were largely eradicated in the United States in part due to the use of window screens. Today most houses in Australia, the United States and Canada have screens on all operable windows, the excess screen is trimmed close to the spline with a sharp utility knife.
Common spline sizes range from 3.6 mm to 4.8 mm, the spline is often manufactured with parallel ridges running along the length of the spline to provide a better grip and compliance when it is pressed into the channel. A spline roller — a special tool that consists of a wheel on a handle — is used to press the spline into the frame. The wheel edge is concave, to help it hold the spline, some spline rollers are double-ended and have both convex and concave rollers, the convex roller can be used to seat the spline deeper into the channel without risk of cutting the screen. Driving the spline into the channel tends to tension the screen on the frame, window screens primarily maintain the view and airflow of windows while protecting against insects from flying or crawling inside the house. They are not generally intended for preventing young kids from falling out of windows, stopping home intruders and this effect has been used to collect water from fog. Screen painting is a folk art consisting of paintings on window screens and it is possible to print images directly onto fiberglass screen cloth using specially designed inkjet printers.
The most common used for the mesh of window screens are aluminum. Aluminum is generally available in aluminum or in an applied black or charcoal color. Fiberglass is available in light gray as well as charcoal colors, fiberglass is less expensive, and has the advantage of not denting when hit or pushed, but it is somewhat more opaque than aluminum. For this reason, dark aluminum allows a view of windows from the exterior
Music is an art form and cultural activity whose medium is sound organized in time. The common elements of music are pitch, dynamics, different styles or types of music may emphasize, de-emphasize or omit some of these elements. The word derives from Greek μουσική, Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as the harmony of the spheres and it is music to my ears point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, for example, There is no noise, the creation, performance and even the definition of music vary according to culture and social context. There are many types of music, including music, traditional music, art music, music written for religious ceremonies. For example, it can be hard to draw the line between some early 1980s hard rock and heavy metal, within the arts, music may be classified as a performing art, a fine art or as an auditory art.
People may make music as a hobby, like a teen playing cello in a youth orchestra, the word derives from Greek μουσική. According to the Online Etymological Dictionary, the music is derived from mid-13c. Musike, from Old French musique and directly from Latin musica the art of music and this is derived from the. Greek mousike of the Muses, from fem. of mousikos pertaining to the Muses, from Mousa Muse. In classical Greece, any art in which the Muses presided, Music is composed and performed for many purposes, ranging from aesthetic pleasure, religious or ceremonial purposes, or as an entertainment product for the marketplace. With the advent of recording, records of popular songs. Some music lovers create mix tapes of their songs, which serve as a self-portrait. An environment consisting solely of what is most ardently loved, amateur musicians can compose or perform music for their own pleasure, and derive their income elsewhere. Professional musicians sometimes work as freelancers or session musicians, seeking contracts and engagements in a variety of settings, There are often many links between amateur and professional musicians.
Beginning amateur musicians take lessons with professional musicians, in community settings, advanced amateur musicians perform with professional musicians in a variety of ensembles such as community concert bands and community orchestras. However, there are many cases where a live performance in front of an audience is recorded and distributed. Live concert recordings are popular in classical music and in popular music forms such as rock, where illegally taped live concerts are prized by music lovers
In photography and computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample, that is, it carries only intensity information. Images of this sort, known as black-and-white, are composed exclusively of shades of gray, grayscale images are distinct from one-bit bi-tonal black-and-white images, which in the context of computer imaging are images with only two colors and white. Grayscale images have many shades of gray in between, but they can be synthesized from a full color image, see the section about converting to grayscale. The intensity of a pixel is expressed within a range between a minimum and a maximum, inclusive. This range is represented in a way as a range from 0 and 1. This notation is used in papers, but this does not define what black or white is in terms of colorimetry. Another convention is to employ percentages, so the scale is from 0% to 100%. This is used for an intuitive approach, but if only integer values are used, the range encompasses a total of only 101 intensities.
Also, the notation is used in printing to denote how much ink is employed in halftoning. In computing, although the grayscale can be computed through rational numbers, image pixels are stored in binary, the precision provided by this format is barely sufficient to avoid visible banding artifacts, but very convenient for programming because a single pixel occupies a single byte. Technical uses often require more levels, to full use of the sensor accuracy. Sixteen bits per sample is a convenient choice for such uses, the TIFF and the PNG image file formats support 16-bit grayscale natively, although browsers and many imaging programs tend to ignore the low order 8 bits of each pixel. No matter what pixel depth is used, the binary representations assume that 0 is black, a common strategy is to use the principles of photometry or, more broadly, colorimetry to match the luminance of the grayscale image to the luminance of the original color image. This ensures that both images will have the absolute luminance, as can be measured in its SI units of candelas per square meter, in any given area of the image.
Then, linear luminance is calculated as a sum of the three linear-intensity values. To encode grayscale intensity in linear RGB, each of the three primaries can be set to equal the calculated linear luminance Y, linear luminance typically needs to be gamma compressed to get back to a conventional non-linear representation. In practice, because the three components are equal, it is only necessary to store these values once in sRGB-compatible image formats that support a single-channel representation. The ITU-R BT.709 standard used for HDTV developed by the ATSC uses different color coefficients, although these are numerically the same coefficients used in sRGB above, the effect is different because here they are being applied directly to gamma-compressed values
Allan H. Stevenson
Allan Henry Stevenson was an American bibliographer specializing in the study of handmade paper and watermarks who single-handedly created a new field, the bibliographical analysis of paper. Stevenson proved that the book in fact had been printed nearly twenty years later, Stevenson was born on June 20,1903, in Merlin, Canada. His family moved to Texas where he attended the Rice Institute in Houston, graduating in 1924, after teaching at Rice, he moved to the University of Chicago where he ultimately obtained his doctorate degree in 1949. He taught English at both schools and he died in Chicago on March 31,1970. The screen would usually have attached a design made of copper or brass wire which would leave an impression or watermark in the sheet of paper. He observed that, as the screens were used repeatedly to make paper, a stock of paper manufactured by hand thus would contain two closely similar watermarks which define the stock for bibliographic purposes, or as Stevenson said, watermarks like wrens go in pairs.
He would use these observations to date the manufacture of paper used in early printed books. The Morgan Library and many believed the Missale Speciale pre-dated the Gutenberg Bible and was the first European book printed using movable type. The Morgan had purchased the book from the rare book dealer Hans P. Kraus, paying him $58,000 in cash and trading four extremely rare books. Hearing of the Morgans acquisition, Stevenson began an analysis of its watermarks, in 1960, as Stevenson learned that two German bibliographers were reaching the same conclusion, he announced his discovery. In 1962, he published two articles on the Missale Speciale and in 1966 he published his full length study on it, in his Problem of the Missale Speciale, Stevenson analyzed the four known copies of the missal, along with a fifth shorter version. Stevenson identified several states of these watermarks in the book, reflecting the aging of the watermark as stress was applied to the screen in making the paper. He identified the same watermarks in other books which included their dates of printing or were otherwise firmly datable, in fact, some of those books contained both the identical cross on mounts and identical bulls head watermarks.
Through this information, Stevenson precisely dated the printing of the Missale Speciale to the fall of 1473, bibliographers now accept this proof that the missal was printed in 1473 as conclusive. In fact, As a rule a lot of paper seems to have been obtained. Where there is a run of paper with a specific watermark, in contrast, the presence of a single or few sheets with a particular watermark might reflect an older paper used, and not be indicative of the actual printing date of a book. Block books are undated short religious books in both the text and illustrations were printed from a single woodcut block. Written notations of purchase and rubrication dates, led some scholars to believe that the books had been printed later, in the mid-1960s, Stevenson began an extensive study of block books
Images may be two-dimensional, such as a photograph or screen display, or three-dimensional, such as a statue or hologram. They may be captured by optical devices – such as cameras, lenses, microscopes, etc. and natural objects and phenomena, such as the human eye or water. The word image is used in the broader sense of any two-dimensional figure such as a map, a graph. A volatile image is one that only for a short period of time. This may be a reflection of an object by a mirror, a fixed image, called a hard copy, is one that has been recorded on a material object, such as paper or textile by photography or any other digital process. A mental image exists in a mind, as something one remembers or imagines. The subject of an image need not be real, it may be a concept, such as a graph, function. For example, Sigmund Freud claimed to have dreamed purely in aural-images of dialogs, a still image is a single static image, as distinguished from a kinetic image. This phrase is used in photography, visual media and the industry to emphasize that one is not talking about movies. A film still is a taken on the set of a movie or television program during production.
In literature, imagery is a picture which appeals to the senses. It can both be figurative and literal, a moving image is typically a movie or video, including digital video. It could be an animated display such as a zoetrope, library of Congress – Format Descriptions for Still Images Image Processing – Online Open Research Group Legal Issues Regarding Images Image Copyright Case
The field applies various principles in process engineering and unit operations to the manufacture of paper, chemicals and related materials. Today, the field of paper and chemical engineering is applied to the manufacture of a variety of products. The resulting products of engineering including paper, cardboard. In addition to being a subset of chemical engineering, the field of engineering is closely linked to forest management, product recycling. In the process of mechanical pulping and refining are the two methods used to create the pulp. Grinding is the method of pressing logs and chips against a stone to produce fibers. Refiner pulping is treating wood chips with chemicals or heat and crushing the objects between two disks, one or both of which are rotating, there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo-mechanical pulping, chemi-mechanical pulping, and chemithermomechanical pulping. Further descriptions of each process are contained in this link, Mechanical pulping, the paper created is generally weak since it retains the lignin.
The process of pulping is used to chemically disband the lignin found in the cell walls of the material undergoing the process. After the cellulose fibers are separated from the lignin, a pulp is created which can be treated to create durable paper, chemical pulping can be characterized by two main methods, sulfate pulping and sulfite pulping, and these two methods have different benefits. Sulfate pulping can be performed on a range of tree varieties. Conversely, sulfite pulping results in a volume of pulp which is easier to bleach. However, sulfate pulping is more widely used since the product is more durable, the pulp is processed through an apparatus which renders the pulp as a mesh of fibers. This fiber network is pressed to remove all water contents, the material to be recycled first undergoes mechanical or chemical pulping to render it in pulp form. The resulting pulp is processed in the same way normal pulp is processed, original fiber is sometimes added to enhance the quality. Today, the field of paper and bioprocess engineering is a diverse one, covering areas from biotechnology and nanotechnology to electricity generation
Blotting paper, sometimes called bibulous paper, is a highly absorbent type of paper or other material. It is used to absorb an excess of liquid substances from the surface of writing paper or objects, blotting paper referred to as bibulous paper is mainly used in microscopy to remove excess liquids from the slide before viewing. Blotting paper has sold as a cosmetic to aid in the removal of skin oils. Blotting paper is made from different materials of varying thickness, softness and it is often made of cotton and manufactured on special paper machines. It is reported that a Berkshire paper mill failed to add sizing to a batch of paper that was being produced. Subsequently someone tried to write on a piece of this discarded scrap paper and found that it rapidly absorbed any ink applied, making it unusable for writing. A form of blotter paper commonly known as paper is produced for its absorbent qualities, allowing much better absorption of water. Blotting paper is used in chemical analyses as stationary phase in thin-layer chromatography, blotting paper is used in pool/spa maintenance to measure pH balance.
Small squares of blotting paper attached to disposable plastic strips are impregnated with pH sensitive compounds usually extracted from lichens and these strips are used similarly to litmus strips, however filter paper is usually used for litmus strips, generally to allow for the property of diffusion. Drugs active in microgram range, most notably LSD, are distributed on blotting paper. A liquid solution of the drug is applied to the blotting paper, vanity blotter is blotter art that hasnt been exposed to LSD and is usually sold as a collectible, although inevitably much of this art ends up in illegal distribution. The artwork is printed onto paper and sometimes perforated into tiny squares or tabs which can be torn or cut apart. Most blotter art designs have grid lines as part of the design to aid in perforation or to be left as a cutting grid. Plain white LSD blotter without artwork is commonly referred to as WoW and is not perforated but rather gridded with a pen. Blotting is frequently necessary when using dip pens and occasionally when using fountain pens and this was first done by sprinkling pounce over the wet ink.
Blotting papers are commonly used in cosmetics to absorb excess sebum oil from the face. They are popularly marketed and have sold by numerous cosmetic brands worldwide such as Mac and Bobbi Brown, as well as UK high street store. Prices for blotting papers can range from as low as $3.00 per packet to as high as $30 or more