Wednesday, November 30, 2011

Volcano Lava



Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid attemperatures from 700 °C to 1,200 °C (1,300 °F to 2,200 °F). Up to 100,000 times as viscous as water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties.

A lava flow is a moving outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term lava flow is commonly shortened to lava. Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word "lava" comes from Italian, and is probably derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma (molten rock below the Earth's surface) was apparently in a short account written byFrancesco Serao on the eruption of Vesuvius between May 14 and June 4, 1737. Serao described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of the volcano following heavy rain.


Lava Composition and Behavior.

In general, the composition of a lava determines its behavior more than the temperature of its eruption.
Composition

Igneous rocks, which form lava flows when erupted, can be classified into three chemical types; felsic, intermediate, and mafic (four if one includes the super-heated ultramafic). These classes are primarily chemical; however, the chemistry of lava also tends to correlate with the magma temperature, its viscosity and its mode of eruption.
Felsic lava

Felsic (or silicic) lavas such as rhyolite and dacite typically form lava spines, lava domes or "coulees" (which are thick, short lavas) and are associated with pyroclastic (fragmental) deposits. Most Silicic lava flows are extremely viscous, and typically fragment as they extrude, producing blocky autobreccias. The high viscosity and strength are the result of their chemistry, which is high in silica, aluminium, potassium, sodium, and calcium, forming a polymerized liquid rich in feldspar and quartz, which thus has a higher viscosity than other magma types. Felsic magmas can erupt at temperatures as low as 650 to 750 °C. Unusually hot (>950 °C) rhyolite lavas, however, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States.




Intermediate lava

Intermediate or andesitic lavas are lower in aluminium and silica, and usually somewhat richer in magnesium and iron. Intermediate lavas form andesite domes and block lavas, and may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, and also commonly hotter (in the range of 750 to 950 °C), they tend to be less viscous. Greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, and also occasionally amphibole or pyroxene phenocrysts.
Mafic lava

Mafic or basaltic lavas are typified by their high ferromagnesian content, and generally erupt at temperatures in excess of 950 °C. Basaltic magma is high in iron and magnesium, and has relatively lower aluminium and silica, which taken together reduces the degree of polymerization within the melt. Owing to the higher temperatures, viscosities can be relatively low, although still thousands of times more viscous than water. The low degree of polymerization and high temperature favors chemical diffusion, so it is common to see large, well-formed phenocrysts within mafic lavas. Basalt lavas tend to produce low-profile shield volcanoes or "flood basalt fields", because the fluidal lava flows for long distances from the vent. The thickness of a basalt lava, particularly on a low slope, may be much greater than the thickness of the moving lava flow at any one time, because basalt lavas may "inflate" by supply of lava beneath a solidified crust. Most basalt lavas are of ʻAʻā orpāhoehoe types, rather than block lavas. Underwater they can form "pillow lavas", which are rather similar to entrail-type pahoehoe lavas on land.
Ultramafic lava

Ultramafic lavas such as komatiite and highly magnesian magmas which form boninite take the composition and temperatures of eruptions to the extreme. Komatiites contain over 18% magnesium oxide, and are thought to have erupted at temperatures of 1600 °C. At this temperature there is no polymerization of the mineral compounds, creating a highly mobile liquid with viscosity as low as that of water. Most if not all ultramafic lavas are no younger than the Proterozoic, with a few ultramafic magmas known from the Phanerozoic. No modern komatiite lavas are known, as the Earth's mantle has cooled too much to produce highly magnesian magmas.


Lava Behavior.

The viscosity of lava is important because it determines how the lava will behave. Lavas with high viscosity are rhyolite, dacite, andesite and trachyte, with cooled basaltic lava also quite viscous; those with low viscosities are freshly erupted basalt, carbonatite and occasionally andesite.

Highly viscous lava shows the following behaviors:
tends to flow slowly, clog, and form semi-solid blocks which resist flow
tends to entrap gas, which form vesicles (bubbles) within the rock as they rise to the surface
correlates with explosive or phreatic eruptions and is associated with tuff and pyroclastic flows

Highly viscous lavas do not usually flow as liquid, and usually form explosive fragmental ash or tephra deposits. However, a degassed viscous lava or one which erupts somewhat hotter than usual may form a lava flow.

Lava with low viscosity shows the following behaviors:
tends to flow easily, forming puddles, channels, and rivers of molten rock
tends to easily release bubbling gases as they are formed
eruptions are rarely pyroclastic and are usually quiescent
volcanoes tend to form broad shields rather than steep cones

Lavas also may contain many other components, sometimes including solid crystals of various minerals, fragments of exotic rocks known as xenoliths and fragments of previously solidified lava.




Reference: H. Pinkerton, N. Bagdassarov. "ScienceDirect – Journal of Volcanology and Geothermal Research : Transient phenomena in vesicular lava flows based on laboratory experiments with analogue materials". www.sciencedirect.com

Names of Famous Volcanoes

The volatile features of Planet Earth are the most important topic of study because it has led to some of the most famous volcanoes. The names of famous volcanoes cover diverse areas of the entire earth. The study of volcanoes is an exciting career opportunity for young individuals. It is very closely related to geology. Geologists can predict new volcanic activity, by analyzing the series of events that led to previous eruptions.

The following are three names of famous volcanoes:
Mount Vesuvius, Italy

Mount Vesuvius is considered one of the most dangerous volcanoes. The eruption of 79 AD destroyed the cities of Pompeii and Herculaneum. The subsequent eruptions have been less severe. It poses many threats to the large population in its vicinity. This makes it a volcano to watch out for.



mount vesuvius

Mount Tambora, Indonesia


Mt Tambora’s eruption of 1815 left nearly 71,000 people dead. It measured 7 on the Volcanic Explosivity Index. This was the largest eruption in the history of the volcano. It had a profound impact on the environment, and created a volcanic winter. The following year was termed as the ‘year without a summer’. This has made it the world’s most famous volcano. The snowstorms in New England and Eastern Canada can be attributed to this volcano. This led to crop failure and loss of human lives. The eruptions in 1812, 1813, and 1814, too, led to climatic changes, which resulted in an explosion.



Mount Tambora

Krakatau, Indonesia
Among the 130 active volcanoes in Indonesia, Krakatau is the most famous because of its explosive eruptions. In terms of size, it is not one of the largest volcanoes. It showcased its might in an 1883 explosion, which resulted in the disintegration of the northern portion of the island. This later caused many tsunamis. Nearly 36,000 individuals lost their lives due to the massive walls of water. Several towns and villages that lay along the coastline were wiped out. Some islands, too, were destroyed. The temperatures, too, dropped around the world.


Krakatau
There are other names of famous volcanoes worthy of mention:
  • Crater Lake, Oregon: 
    Its last eruption was 6600 years ago. It had the force equivalent to an atomic bomb.
  • Mt. St. Helens, Washington:
    The earthquake in 1980 resulted in the largest landslide in the history of America.
  • Mt. Rainier, Washington: 
    The lava flowed for nearly 70 miles.
  • Mauna Loa, Hawaii:
    It is the largest volcano above sea level. It measures 60 miles at the base.

Source: "Names of Famous Volcanoes, World Famous Volcanoes, List of Famous Volcanoes."Best Worldwide Top 10 Travel Destinations, Cheap Beach Vacations East Coast, Popular Top Ten Best Travel Destinations, Travel Information. Web. 30 Nov. 2011. <http://www.travelfront.com/names-of-famous-volcanoes/>.

Volcano




A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused byconvergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism.

Intraplate volcanism has also been postulated to be caused by mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs from the core-mantle boundary, 3,000 km deep in the Earth.



Volcano Environments.


There are more than 500 active volcanoes (those that have erupted at least once within recorded history) in the world--50 of which are in the United States (Hawaii, Alaska, Washington, Oregon, and California)--although many more are hidden under the seas. Most active volcanoes are strung like beads along, or near, the margins of the continents, and more than half en circle the Pacific Ocean as a "Ring of Fire."

Many volcanoes are in and around the Mediterranean Sea. Mount Etna in Sicily is the largest and hiqhest of these mountains. Italy's Vesuvius is the only active volcano on the European mainland. Near the island of Vulcano, the volcano Stromboli has been in a state of nearly continuous, mild eruption since early Roman times. At night, sailors in the Mediterranean can see the glow from the fiery molten material that is hurled into the air. Very appropriately, Stromboli has been called "the lighthouse of the Mediterranean.

Some volcanoes crown island areas lying near the continents, and others form chains of islands in the deep ocean basins. Volcanoes tend to cluster along narrow mountainous belts where folding and fracturing of the rocks provide channelways to the surface for the escape of magma. Significantly, major earthquakes also occur along these belts, indicating that volcanism and seismic activity are often closely related, responding to the same dynamic Earth forces.

In a typical "island-arc" environment, volcanoes lie along the crest of an arcuate, crustal ridge bounded on its convex side by a deep oceanic trench. The granite or granitelike layer of the continental crust extends beneath the ridge to the vicinity of the trench. Basaltic magmas, generated in the mantle beneath the ridge, rise along fractures through the granitic layer. These magmas commonly will be modified or changed in composition during passage through the granitic layer and erupt on the surface to form volcanoes built largely of nonbasaltic rocks.






 Photograph of Mount Sinaburg, Sumatra
 Diagram showing an island-arc environment



In a typical "oceanic" environment, volcanoes are alined along the crest of a broad ridge that marks an active fracture system in the oceanic crust. Basaltic magmas, generated in the upper mantle beneath the ridge, rise along fractures through the basaltic layer. Because the granitic crustal layer is absent, the magmas are not appreciably modified or changed in composition and they erupt on the surface to form basaltic volcanoes.

In the typical "continental" environment, volcanoes are located unstable, mountainous belts that have thick roots of granite or granitelike rock. Magmas, generated near the base of the mountain root, rise slowly or intermittently along fractures in the crust. During passage through the granitic layer, magmas are commonly modified or changed in composition and erupt on the surface to form volcanoes constructed of nonbasaltic rocks.


Source: ^ "Volcano Environments". U.S. Geological Survey.


Tuesday, November 29, 2011

Printmaking


Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints with an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable of producing multiples of the same piece, which is called a 'print'. Each piece produced is not a copy but considered an original since it is not a reproduction of another work of art and is technically (more correctly) known as an 'impression'. Printmaking (other than monotyping) is not chosen only for its ability to produce multiple copies, but rather for the unique qualities that each of the printmaking processes lends itself to.
Prints are created by transferring ink from a matrix or through a prepared screen to a sheet of paper or other material. Common types of matrices include: metal plates, usually copper or zinc, or polymer plates for engraving or etching; stone, aluminum, or polymer for lithography; blocks of wood for woodcuts and wood engravings; and linoleum for linocuts. Screens made of silk or synthetic fabrics are used for the screen printing process. Other types of matrix substrates and related processes are discussed below.
Multiple impressions printed from the same matrix form an edition. Since the late 19th century, artists have generally signed individual impressions from an edition and often number the impressions to form a limited edition. Prints may also be printed in book form, such as illustrated books or artist's books.


Techniques.


Overview

Printmaking techniques are generally divided into the following basic categories:
  • Relief, where ink is applied to the original surface of the matrix. Relief techniques include: woodcut or woodblock as the Asian forms are usually known, wood engraving, linocut and metalcut;
  • Intaglio, where ink is applied beneath the original surface of the matrix. Intaglio techniques include: engraving, etching, mezzotint, aquatint, where the matrix retains its original surface, but is specially prepared and/or inked to allow for the transfer of the image. Planographic techniques include: lithography, monotyping, and digital techniques.
  • Stencil, where ink or paint is pressed through a prepared screen, including: screenprinting and pochoir
Other types of printmaking techniques outside these groups include collagraphy, viscosity printing, and foil imaging. Collagraphy is a printmaking technique in which textured material is adhered to the printing matrix. This texture is transferred to the paper during the printing process. Contemporary printmaking may include digital printing, photographic mediums, or a combination of digital, photographic, and traditional processes.
Many of these techniques can also be combined, especially within the same family. For example Rembrandt's prints are usually referred to as "etchings" for convenience, but very often include work in engraving and drypoint as well, and sometimes have no etching at all.


Woodcut


Woodcut, a type of relief print, is the earliest printmaking technique, and the only one traditionally used in the Far East. It was probably first developed as a means of printing patterns on cloth, and by the 5th century was used in China for printing text and images on paper. Woodcuts of images on paper developed around 1400 in Europe, and slightly later in Japan. These are the two areas where woodcut has been most extensively used purely as a process for making images without text.
The artist draws a design on a plank of wood, or on paper which is transferred to the wood. Traditionally the artist then handed the work to a specialist cutter, who then uses sharp tools to carve away the parts of the block that will not receive ink. The surface of the block is then inked with the use of a brayer, and then a sheet of paper, perhaps slightly damp, is placed over the block. The block is then rubbed with abaren or spoon, or is run through a printing press. If in color, separate blocks can be used for each color,or a technique called reduction printing can be used.
Reduction printing is a name used to describe the process of using one block to print several layers of color on one print. This usually involves cutting a small amount of the block away, and then printing the block many times over on different sheets before washing the block, cutting more away and printing the next color on top. This allows the previous color to show through. This process can be repeated many times over. The advantages of this process is that only one block is needed, and that different components of an intricate design will line up perfectly. The disadvantage is that once the artist moves on to the next layer, no more prints can be made.
Another variation of woodcut printmaking is the cukil technique, made famous by the Taring Padi underground community in Java, Indonesia. Taring Padi Posters usually resemble intricately printed cartoon posters embedded with political messages. Images—usually resembling a visually complex scenario—are carved unto a wooden surface called cukilan, then smothered with printer's ink before pressing it unto media such as paper or canvas.

Engraving

Gravers come in a variety of shapes and sizes that yield different line types. The burin produces a unique and recognizable quality of line that is characterized by its steady, deliberate appearance and clean edges. Other tools such as mezzotint rockers, roulets and burnishers are used for texturing effects.
The process was developed in Germany in the 1430s from the engraving used by goldsmiths to decorate metalwork. Engravers use a hardened steel tool called a burin to cut the design into the surface of a metal plate, traditionally made of copper. Engraving using a burin is generally a difficult skill to learn.
To make a print, the engraved plate is inked all over, then the ink is wiped off the surface, leaving only ink in the engraved lines. The plate is then put through a high-pressure printing press together with a sheet of paper (often moistened to soften it). The paper picks up the ink from the engraved lines, making a print. The process can be repeated many times; typically several hundred impressions (copies) could be printed before the printing plate shows much sign of wear, except when drypoint, which gives much shallower lines, is used.
In the 20th century, true engraving was revived as a serious art form by artists including Stanley William Hayter.

Etching

Etching is part of the intaglio family (along with engraving, drypoint, mezzotint, and aquatint.) The process is believed to have been invented by Daniel Hopfer (circa 1470-1536) of Augsburg, Germany, who decorated armour in this way, and applied the method to printmaking. Etching soon came to challenge engraving as the most popular printmaking medium. Its great advantage was that, unlike engraving which requires special skill in metalworking, etching is relatively easy to learn for an artist trained in drawing.
Artists using this technique include Albrecht Dürer, Rembrandt, Francisco Goya, Whistler, Otto Dix,James Ensor, Edward Hopper, Käthe Kollwitz, Pablo Picasso, Cy Twombly, Lucas van Leyden,Carlos Alvarado Lang.
Etching prints are generally linear and often contain fine detail and contours. Lines can vary from smooth to sketchy. An etching is opposite of a woodcut in that the raised portions of an etching remain blank while the crevices hold ink. In pure etching, a metal (usually copper, zinc or steel) plate is covered with a waxy or acrylic ground. The artist then draws through the ground with a pointed etching needle. The exposed metal lines are then etched by dipping the plate in a bath of etchant (e.g. nitric acid or ferric chloride). The etchant "bites" into the exposed metal, leaving behind lines in the plate. The remaining ground is then cleaned off the plate, and the printing process is then just the same as for engraving.


Mezzotint

An intaglio variant of engraving in which the image is formed from subtle gradations of light and shade. Mezzotint—from the Italian mezzo ("half") and tinta ("tone")--is a "dark manner" form of printmaking, which requires artists to work from dark to light. To create a mezzotint, the surface of a copper printing plate is roughened evenly all over with the aid of a tool known as a rocker; the image is then formed by smoothing the surface with a tool known as a burnisher. When inked, the roughened areas of the plate will hold more ink and print more darkly, while smoother areas of the plate hold less or no ink, and will print more lightly or not at all. It is, however, possible to create the image by only roughening the plate selectively, so working from light to dark.
Mezzotint is known for the luxurious quality of its tones: first, because an evenly, finely roughened surface holds a lot of ink, allowing deep solid colors to be printed; secondly because the process of smoothing the texture with burin, burnisher and scraper allows fine gradations in tone to be developed.
The mezzotint printmaking method was invented by Ludwig von Siegen (1609–1680). The process was used widely in England from the mid-eighteenth century, to reproduce oil paintings and portraits.


Aquatint

A technique used in Intaglio etchings. Like etching, aquatint technique involves the application of acid to make marks in a metal plate. Where the etching technique uses a needle to make lines that retain ink, aquatint relies on powdered rosin which is acid resistant in the ground to create a tonal effect. The rosin is applied in a light dusting by a fan booth, the rosin is then cooked until set on the plate. At this time the rosin can be burnished or scratched out to affect its tonal qualities. The tonal variation is controlled by the level of acid exposure over large areas, and thus the image is shaped by large sections at a time.
Goya used aquatint for most of his prints.



Drypoint

A variant of engraving, done with a sharp point, rather than a v-shaped burin. While engraved lines are very smooth and hard-edged, drypoint scratching leaves a rough burr at the edges of each line. This burr gives drypoint prints a characteristically soft, and sometimes blurry, line quality. Because the pressure of printing quickly destroys the burr, drypoint is useful only for very small editions; as few as ten or twenty impressions. To counter this, and allow for longer print runs, electro-plating (here called steelfacing) has been used since the nineteenth century to harden the surface of a plate.
The technique appears to have been invented by the Housebook Master, a south German fifteenth century artist, all of whose prints are in drypoint only. Among the most famous artists of the old master print: Albrecht Dürer produced 3 drypoints before abandoning the technique; Rembrandt used it frequently, but usually in conjunction with etching and engraving.


Lithography

Lithography is a technique invented in 1798 by Alois Senefelder and based on the chemical repulsion of oil and water. A porous surface, normally limestone, is used; the image is drawn on the limestone with a greasy medium. Acid is applied, transferring the grease to the limestone, leaving the image 'burned' into the surface. Gum arabic, a water soluble substance, is then applied, sealing the surface of the stone not covered with the drawing medium. The stone is wetted, with water staying only on the surface not covered in grease-based residue of the drawing; the stone is then 'rolled up', meaning oil ink is applied with a roller covering the entire surface; since water repels the oil in the ink, the ink adheres only to the greasy parts, perfectly inking the image. A sheet of dry paper is placed on the surface, and the image is transferred to the paper by the pressure of the printing press. Lithography is known for its ability to capture fine gradations in shading and very small detail.
A variant is photo-lithography, in which the image is captured by photographic processes on metal plates; printing is carried out in the same way.


Screenprinting

Screenprinting (occasionally known as "silkscreen", or "serigraphy") creates prints by using a fabric stencil technique; ink is simply pushed through the stencil against the surface of the paper, most often with the aid of a squeegee. Generally, the technique uses a natural or synthetic 'mesh' fabric stretched tightly across a rectangular 'frame,' much like a stretched canvas. The fabric can be silk, nylon monofilament, multifilament polyester, or even stainless steel. While commercial screenprinting often requires high-tech, mechanical apparatuses and calibrated materials, printmakers value it for the "Do It Yourself" approach, and the low technical requirements, high quality results. The essential tools required are a squeegee, a mesh fabric, a frame, and a stencil. Unlike many other printmaking processes, a printing press is not required, as screenprinting is essentially stencil printing.
Screenprinting may be adapted to printing on a variety of materials, from paper, cloth, and canvas to rubber, glass, and metal. Artists have used the technique to print on bottles, on slabs of granite, directly onto walls, and to reproduce images on textiles which would distort under pressure from printing presses.


Monotype

Monotyping is a type of printmaking made by drawing or painting on a smooth, non-absorbent surface. The surface, or matrix, was historically a copper etching plate, but in contemporary work it can vary from zinc or glass to acrylic glass. The image is then transferred onto a sheet of paper by pressing the two together, usually using a printing-press. Monotypes can also be created by inking an entire surface and then, using brushes or rags, removing ink to create a subtractive image, e.g. creating lights from a field of opaque color. The inks used may be oil based or water based. With oil based inks, the paper may be dry, in which case the image has more contrast, or the paper may be damp, in which case the image has a 10 percent greater range of tones.
Unlike monoprinting, monotyping produces a unique print, or monotype, because most of the ink is removed during the initial pressing. Although subsequent reprintings are sometimes possible, they differ greatly from the first print and are generally considered inferior. A second print from the original plate is called a "ghost print" or "cognate". Stencils, watercolor, solvents, brushes, and other tools are often used to embellish a monotype print. Monotypes are often spontaneously executed and with no preliminary sketch.
Monotypes are the most painterly method among the printmaking techniques, a unique print that is essentially a printed painting. The principal characteristic of this medium is found in its spontaneity and its combination of printmaking, painting, and drawing media.


Monoprint

Monoprinting is a form of printmaking that uses a matrix such as a woodblock, litho stone, or copper plate, but produces impressions that are unique. Multiple unique impressions printed from a single matrix are sometimes known as a variable edition. There are many techniques used in monoprinting, including collagraph, collage, hand-painted additions, and a form of tracing by which thick ink is laid down on a table, paper is placed on the ink, and the back of the paper is drawn on, transferring the ink to the paper. Monoprints can also be made by altering the type, color, and viscosity of the ink used to create different prints. Traditional printmaking techniques, such as lithography, woodcut, and intaglio, can be used to make monoprints.


Digital prints

Digital prints refers to images printed using a digital printer instead of a traditional printing press. These images can be printed to a variety of substrates including paper, cloth, or plastic canvas. Accurate color reproduction and the type of ink used (see below) are key to distinguishing high quality from low quality digital prints. Metallics (silvers, golds) are particularly difficult to reproduce accurately because they reflect light back to digital scanners. High quality digital prints typically are reproduced with very high-resolution data files with very high-precision printers. The substrate used has an effect on the final colors and cannot be ignored when selecting a color palette.


Pigment-based vs. dye-based inks

Unlike pigment, dyes dissolve when mixed into a liquid. Dyes are organic (not mineral). Although most are synthetic, derived from petroleum, they can be made from vegetable or animal sources. Dyes are well suited for textiles where the liquid dye penetrates and chemically bonds to the fiber. Because of the deep penetration, more layers of material must lose their color before the fading is apparent. Dyes, however, are not suitable for the relatively thin layers of ink laid out on the surface of a print.
Pigment is a finely ground, particulate substance which, when mixed or ground into a liquid to make ink or paint, does not dissolve, but remains dispersed or suspended in the liquid. Pigments are categorized as either inorganic (mineral) or organic (synthetic).
A pigment, such as red iron oxide (rust) is simply an oxidized form of iron. One could leave iron, lead, or gold in the sun for a million years and they would never change color or change into another substance. In contrast, man-made synthetic and vegetable water-soluble dyes can fade rapidly, often within one to six months.


"Giclée" prints

The term Giclée, derived from the French and meaning "to spurt", is sometimes used in the commercial fine art print community to describe the ink-jet printing processes listed above. It was originally associated with Iris printing process. Today fine art prints produced on ink-jet machines using the CcMmYK color model are generally called "Giclée".


Foil imaging

In art, foil imaging is a printmaking technique made using the Iowa Foil Printer, developed by Virginia A. Myers from the commercial foil stamping process. This uses gold leaf and acrylic foil in the printmaking process.




Sources:
"Printmaking." Wikipedia, the Free Encyclopedia. Web. 14 Dec. 2011. <http://en.wikipedia.org/wiki/Printmaking>.

Newcastle University

Newcastle University is a major research-intensive university located in Newcastle upon Tyne in the north-east of England. It was established as a School of Medicine and Surgery in 1834 and became the University of Newcastle upon Tyne by an Act of Parliament in August 1963. Newcastle University is a member of the Russell Group, an association of research-intensive UK universities. The University has one of the largest EU research portfolios in the UK. The post-nominal letters of graduates commonly have N'cle attached to indicate the institution.


History.



The University has its origins in the School of Medicine and Surgery which was established in Newcastle upon Tyne in October 1834, providing basic lectures and practical demonstrations to around 26 students. In June 1851, following a dispute amongst the teaching staff, the School was split into two rival institutions: the majority forming the Newcastle College of Medicine, with the others establishing themselves as the Newcastle upon Tyne College of Medicine and Practical Science. By 1852, the majority college was formally linked to theUniversity of Durham, its first 'Licence in Medicine' (Lic.Med) being awarded in 1856, and its teaching certificates were recognised by theUniversity of London for graduation in medicine. The two colleges amalgamated in 1857 and renamed the University of Durham College of Medicine in 1870.
Attempts to realise a place for the teaching of sciences in the city were finally met with the foundation of the College of Physical Science in 1871. The college offered instruction in mathematics, physics, chemistry and geology to meet the growing needs of the mining industry, becoming the Durham College of Physical Science in 1883 and then renamed after William George Armstrong as Armstrong College in 1904. Both these separate and independent institutions later became part of the University of Durham, whose 1908 Act formally recognised that the University consisted of two Divisions, Durham and Newcastle, on two different sites. By 1908, the Newcastle Division was teaching a full range of subjects in the Faculties of Medicine, Arts, and Science, which also included agriculture and engineering.
Throughout the early 20th century, the medical and science colleges vastly outpaced the growth of their Durham counterparts and a Royal Commission in 1934 recommended the merger of the two colleges to form King's College, Durham. Growth of the Newcastle Division of the federal Durham University led to tensions within the structure and on 1 August 1963 an Act of Parliament separated the two, creating the University of Newcastle upon Tyne.

Campus.


The university occupies a campus site close to Haymarket in central Newcastle upon Tyne. It is located to the northwest of the city centre between the open spaces of Leazes Park and the Town Moor.
The Armstrong building is the oldest building on the campus and is the site of the original Armstrong College. The building was constructed in three stages; the north east wing was completed first at a cost of £18,000 and opened by HRH Princess Louise on 5 November 1888. The south-east wing, which includes the Jubilee Tower, and south-west wings were opened in 1894. The Jubilee Tower was built with surplus funds raised from an Exhibition to mark Queen Victoria's Jubilee in 1887. The north-west front, forming the main entrance, was completed in 1906 and features two stone figures to represent science and the arts. Much of the later construction work was financed by Sir Isaac Lowthian Bell, the metallurgist and former Lord Mayor of Newcastle, after whom the main tower is named. In 1906 it was opened by King Edward VII.
The building contains the King's Hall, which serves as the university's chief hall for ceremonial purposes where Congregation ceremonies are held. It can contain 500 seats. King Edward VII gave permission to call the Great Hall, King's Hall. Graduation photographs are often taken in the University Quadrangle, next to the Armstrong building. In 1949 the Quadrangle was turned into a formal garden in memory of members of Newcastle University who gave their lives in the two World Wars.
The Bruce Building is a former brewery, constructed between 1896 and 1900 on the site of the Hotspur Hotel, as the new premises of Newcastle Breweries Limited.
The Devonshire Building, opened in 2004, incorporates in an energy efficient design photovoltaic cells which help to power the motorised shades which control the temperature of the building and geothermal heating coils. Its architects won awards in the Hadrian awards and the RICS Building of the Year Award 2004. The university won a Green Gown award for its construction.
Plans for additions and improvements to the campus were made public in March 2008 and completed in 2010 at a cost of £200 million. They include a redevelopment of the south-east (Haymarket) façade with a five-storey King's Gate building and sculpture as well as new student accommodation. Two additional buildings for the school of medicine were also built.
In addition to the city centre campus there are buildings such as the Dove Marine Laboratory located on Cullercoats Bay. The University also has two branches in Asia; in Malaysia and Singapore.
Newcastle University Library has received the Charter Mark five times in a row. It consists of three main facilities. The Robinson Library is the main University library. It is named after Philip Robinson, a bookseller in the city following a bequest in the will of his widow Marjorie in 1989. A major refurbishment was completed in 2009. The Walton Library specialises in services for Biomedical Sciences in the Medical School. It is named after Lord Walton of Detchant, former Dean of the Faculty of Medicine and Professor of Neurology. The library has a relationship with the Northern region of the NHS allowing their staff to use the library for research and study. The Law Library specialises in resources relating to law. Some schools within the University, such as the School of Modern Languages, also have their own smaller libraries with smaller highly-specialised collections.


Sources:
"Newcastle University." Wikipedia, the Free Encyclopedia. Web. 14 Dec. 2011. <http://en.wikipedia.org/wiki/Newcastle_University>.

Newcastle University, Newcastle upon Tyne, United Kingdom, NE1 7RU. Web. 14 Dec. 2011. <http://www.ncl.ac.uk/>.


Democratic Party in the US


The Democratic Party is one of two major contemporary political parties in the United States, along with the Republican Party. The party'ssocially liberal and progressive platform is largely considered center-left in the U.S. political spectrum. The party has the lengthiest record of continuous operation in the United States, and is one of the oldest political parties in the world. Barack Obama is the 15th Democrat to hold the office of President of the United States.
As of the 112th Congress following the 2010 elections, the Democratic Party currently holds a minority of seats in the House of Representatives, but holds a majority of seats in the Senate. It currently holds a minority of state governorships, as well as a minority ofstate legislatures.

History.


The Democratic Party evolved from Anti-Federalist factions that opposed the fiscal policies of Alexander Hamilton in the early 1790s.Thomas Jefferson and James Madison organized these factions into the Democratic-Republican Party. The party favored states' rights and strict adherence to the Constitution; it opposed a national bank and wealthy, moneyed interests. The Democratic-Republican Party ascended to power in the election of 1800.
The Democrats split over the choice of a successor to President James Buchanan along Northern and Southern lines, while the Republican Party gained ascendancy in the election of 1860. As the American Civil War broke out, Northern Democrats were divided into War Democrats and Peace Democrats. The Confederate States of America, seeing parties as evils, did not have any. Most War Democrats rallied to Republican PresidentAbraham Lincoln and the Republicans' National Union Party in 1864, which put Andrew Johnson on the ticket as a Democrat from the South. Johnson replaced Lincoln in 1865 but stayed independent of both parties . The Democrats benefited from white Southerners' resentment of Reconstruction after the war and consequent hostility to the Republican Party. After Redeemers ended Reconstruction in the 1870s, and the extremely violent disenfranchisement of African Americans took place in the 1890s, the South, voting Democratic, became known as the "Solid South." Though Republicans won all but two presidential elections, the Democrats remained competitive. The party was dominated by pro-business Bourbon Democrats led by Samuel J. Tilden and Grover Cleveland, who represented mercantile, banking, and railroad interests; opposed imperialism and overseas expansion; fought for the gold standard; opposed bimetallism; and crusaded against corruption, high taxes, and tariffs. Cleveland was elected to non-consecutive presidential terms in 1884 and 1892.
After the War of 1812, the party's chief rival, the Federalist Party disbanded. Democratic-Republicans split over the choice of a successor to President James Monroe, and the party faction that supported many of the old Jeffersonian principles, led by Andrew Jackson and Martin Van Buren, became the Democratic Party. Along with the Whig Party, the Democratic Party was the chief party in the United States until the Civil War. The Whigs were a commercial party, and usually less popular, if better financed. The Whigs divided over the slavery issue after the Mexican–American War and faded away. In the 1850s, under the stress of the Fugitive Slave Law and the Kansas–Nebraska Act, anti-slavery Democrats left the party. Joining with former members of existing or dwindling parties, the Republican Party emerged.
Agrarian Democrats demanding Free Silver overthrew the Bourbon Democrats in 1896 and nominated William Jennings Bryan for the presidency (a nomination repeated by Democrats in 1900 and 1908). Bryan waged a vigorous campaign attacking Eastern moneyed interests, but he lost to Republican William McKinley. The Democrats took control of the House in 1910 and elected Woodrow Wilson as president in 1912 and 1916. Wilson effectively led Congress to put to rest the issues of tariffs, money, and antitrust that had dominated politics for 40 years with new progressive laws. The Great Depression in 1929 that occurred under Republican President Herbert Hoover and the Republican Congress set the stage for a more liberal government; the Democrats controlled the House of Representatives nearly uninterrupted from 1931 until 1995 and won most presidential elections until 1968. Franklin D. Roosevelt, elected to the presidency in 1932, came forth with government programs called the New Deal. New Deal liberalism meant the promotion of social welfare, labor unions, civil rights, and regulation of business. The opponents, who stressed long-term growth, support for business, and low taxes, started calling themselves "conservatives."
Issues facing parties and the United States after World War II included the Cold War and the Civil Rights Movement. Republicans attracted conservatives and white Southerners from the Democratic coalition with their resistance to New Deal and Great Society liberalism and the Republicans' use of the Southern strategy. African Americans, who traditionally supported the Republican Party, began supporting Democrats following the ascent of the Franklin Roosevelt administration, the New Deal, and the Civil Rights movement. The Democratic Party's main base of support shifted to the Northeast, marking a dramatic reversal of history. Bill Clinton was elected to the presidency in 1992, governing as a New Democrat. The Democratic Party lost control of Congress in the election of 1994 to the Republican Party. Re-elected in 1996, Clinton was the first Democratic President since Franklin Roosevelt to be elected to two terms. Following twelve years of Republican rule, the Democratic Party regained majority control of both the House and the Senate in the 2006 elections. Some of the party's key issues in the early 21st century in their last national platform have included the methods of how to combat terrorism, homeland security, expanding access to health care, labor rights, environmentalism, and the preservation of liberal government programs. In the 2010 elections, the Democratic Party lost control of the House, but kept a small majority in the Senate (reduced from the 111th Congress). It also lost its majority in state legislatures and state governorships.
The Democratic Party traces its origins to the inspiration of Democratic-Republican Party, founded by Thomas Jefferson, James Madison, and other influential opponents of the Federalists in 1792. That party also inspired the Whigs and modern Republicans. Organizationally, the modern Democratic Party truly arose in the 1830s, with the election of Andrew Jackson. Since the division of the Republican Party in the election of 1912, it has gradually positioned itself to the left of the Republican Party on economic and social issues. Until the period following the passage of the Civil Rights Act of 1964, the Democratic Party was primarily a coalition of two parties divided by region. Southern Democrats were typically given high conservative ratings by the American Conservative Union while northern Democrats were typically given very low ratings. Southern Democrats were a core bloc of the bipartisanconservative coalition which lasted through the Reagan-era. The economically activist philosophy of Franklin D. Roosevelt, which has strongly influenced American liberalism, has shaped much of the party's economic agenda since 1932, and served to tie the two regional factions of the party together until the late 1960s. In fact, Roosevelt's New Deal coalition usually controlled the national government until the 1970s.
As of 2010, Gallup polling found that 31% of Americans identified as Democrats, 29% as Republicans, and 38% as independents. A Pew Research Center survey of registered voters released August 2010 stated that 47% identified as Democrats or leaned towards the party, in comparison to 43% of Republicans.


Sources:

Democrats.org. Web. 14 Dec. 2011. <http://www.democrats.org/>.

"Democratic Party (United States)." Wikipedia, the Free Encyclopedia. Web. 14 Dec. 2011. <http://en.wikipedia.org/wiki/Democratic_Party_(United_States)>.

Republican Party in the US


The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the GOP (Grand Old Party). The party's platform generally reflects American conservatism in the U.S. political spectrum and is considered center-right, in contrast to the center-left Democratic Party.
In the 112th Congress, elected in 2010, the Republican Party holds a majority of seats in the House of Representatives, and a minority of seats in the Senate. The party holds the majority of governorships, as well as the majority of state legislatures, and control of one chamber in five states.

History.
Founded in Northern States in 1854 by anti-slavery activists, modernizers, ex-Whigs and ex-Free Soilers, the Republican Party quickly became the principal opposition to the dominant Democratic Party and the briefly popular Know Nothing Party. The main cause was opposition to the Kansas–Nebraska Act, which repealed the Missouri Compromise by which slavery was kept out of Kansas. The Republicans saw the expansion of slavery as a great evil. The first public meeting where the name "Republican" was suggested for a new anti-slavery party was held on March 20, 1854 in a schoolhouse in Ripon, Wisconsin. The first official party convention was held on July 6, 1854 in Jackson, Michigan. By 1858, the Republicans dominated nearly all Northern states. The Republican Party first came to power in 1860 with the election of Lincoln to the Presidency and Republicans in control of Congress and the northern states. It oversaw the saving of the union, the destruction of slavery, and the provision of equal rights to all men in the American Civil War and Reconstruction, 1861-1877. The Republicans' initial base was in the Northeast and the upper Midwest. With the realignment of parties and voters in the Third Party System, the strong run of John C. Fremont in the 1856 Presidential election demonstrated it dominated most northern states. Early Republican ideology was reflected in the 1856 slogan "free labor, free land, free men."  "Free labor" referred to the Republican opposition to slave labor and belief in independent artisans and businessmen. "Free land" referred to Republican opposition to plantation system whereby the rich could buy up all the good farm land and work it with slaves, leaving the yeoman independent farmers the leftovers. The Party had the goal of containing the expansion of slavery, which would cause the collapse of the Slave Power and the expansion of freedom. Lincoln, representing the fast-growing western states, won the Republican nomination in 1860 and subsequently won the presidency. The party took on the mission of saving the Union and destroying slavery during the American Civil War and over Reconstruction. In the election of 1864, it united with pro-war Democrats to nominate Lincoln on the National Union Party ticket.
The party's success created factionalism within the party in the 1870s. Those who felt that Reconstruction had been accomplished and was continued mostly to promote the large-scale corruption tolerated by President Ulysses S. Grant ran Horace Greeley for the presidency. The Stalwarts defended Grant and the spoils system; the Half-Breeds pushed for reform of the civil service. The GOP supported business generally, hard money (i.e., the gold standard), high tariffs to promote economic growth, high wages and high profits, generous pensions for Union veterans, and (after 1893) the annexation of Hawaii. The Republicans supported the pietistic Protestants who demanded Prohibition. As the Northern post-bellum economy boomed with heavy and light industry, railroads, mines, fast-growing cities and prosperous agriculture, the Republicans took credit and promoted policies to sustain the fast growth. Nevertheless, by 1890 the Republicans had agreed to the Sherman Antitrust Act and the Interstate Commerce Commission in response to complaints from owners of small businesses and farmers. The high McKinley Tariff of 1890 hurt the party and the Democrats swept to a landslide in the off-year elections, even defeating McKinley himself.

After the two terms of Democrat Grover Cleveland, the election of William McKinley in 1896 is widely seen as a resurgence of Republican dominance and is sometimes cited as a realigning election. McKinley promised that high tariffs would end the severe hardship caused by the Panic of 1893, and that the GOP would guarantee a sort of pluralism in which all groups would benefit. The Republicans were cemented as the party of business, though mitigated by the succession of Theodore Roosevelt who embraced trust busting. He later ran on a third party ticket of the Progressive Party and challenged his previous successorWilliam Howard Taft. The party controlled the presidency throughout the 1920s, running on a platform of opposition to the League of Nations, high tariffs, and promotion of business interests. Warren G. Harding,Calvin Coolidge and Herbert Hoover were resoundingly elected in 1920, 1924, and 1928 respectively. TheTeapot Dome scandal threatened to hurt the party but Harding died and Coolidge blamed everything on him, as the opposition splintered in 1924. The pro-business policies of the decade seemed to produce an unprecedented prosperity until the Wall Street Crash of 1929 heralded the Great Depression.
The New Deal coalition of Democrat Franklin D. Roosevelt controlled American politics for most of the next three decades, excepting the two-term presidency of Republican Dwight D. Eisenhower. African Americansmoved into the Democratic Party during Roosevelt's time. After Roosevelt took office in 1933, New Deal legislation sailed through Congress at lightning speed. In the 1934 midterm elections, 10 Republican senators went down to defeat, leaving them with only 25 against 71 Democrats. The House of Representatives was split in a similar ratio. Republicans in Congress heavily criticized the "Second New Deal" and likened it to class warfare and socialism. The volume of legislation, and the inability of the Republicans to block it, soon elevated the level of opposition to Roosevelt. Conservative Democrats, mostly from the South, joined with Republicans led by Senator Robert Taft to create the conservative coalition, which dominated domestic issues in Congress until 1964. The Republicans recaptured Congress in 1946 after gaining 13 seats in the Senate and 55 seats in the House.
The second half of the 20th century saw election or succession of Republican presidents Dwight D. Eisenhower, Richard Nixon, Gerald Ford, Ronald Reagan, George H. W. Bush and George W. Bush. The Republican Party, led by House Republican Minority Whip Newt Gingrich campaigning on the Contract with America, was elected to majorities to both houses of Congress in the Republican Revolution of 1994. The Senate majority lasted until 2001, when the Senate became split evenly but was regained in the 2002 elections. Both Republican majorities in the House and Senate were held until the Democrats regained control in the mid-term elections of 2006. In the 21st century, the Republican Party has been defined by social conservatism, a preemptive war foreign policy intended to defeat terrorism and promote global democracy, a more powerful executive branch, supply-side economics, support for gun ownership, and deregulation.
In the Presidential election of 2008, the party's nominees were Senator John McCain, of Arizona, for President and Alaska Governor Sarah Palin for Vice President. They were defeated by Senator Barack Obama of Illinois and Senator Joe Biden of Delaware. In 2009, RepublicansChris Christie and Bob McDonnell were elected to the governorships of New Jersey and Virginia.
2010 was a year of political success for the GOP, starting with the stunning upset win of Scott Brown in the the Massachusetts special Senate election for the seat held for many decades by the Kennedy brothers. November 2010 saw a GOP, retaking control of the House, increasing their number of seats in the Senate, and gaining a majority of governorships. In state legislatures Republicans gained 680 seats, the biggest gain by either party since 1966, which surpassed Democratic gains in the election of 1974. Republicans now hold approximately 3,890 of the total state legislative seats in the U.S., about 53 percent. That is the most seats in the GOP column since 1928. The Republicans will now control at least 54 of the 99 state legislative chambers, the highest number since 1952.




Sources:


"Republican Party (United States)." Wikipedia, the Free Encyclopedia. Web. 14 Dec. 2011. <http://en.wikipedia.org/wiki/Republican_Party_(United_States)>.
RNC: Republican National Committee | RNC: Republican National Committee | GOP. Web. 14 Dec. 2011. <http://www.gop.com/index.php>.