An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials. Groundwater can be extracted using a water well; the study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, a bed of low permeability along an aquifer, aquiclude, a solid, impermeable area underlying or overlying an aquifer. If the impermeable area overlies the aquifer, pressure could cause it to become a confined aquifer. Aquifers occur from near surface to deeper than 30,000 feet; those closer to the surface are not only more to be used for water supply and irrigation, but are more to be topped up by the local rainfall. Many desert areas have limestone hills or mountains within them or close to them that can be exploited as groundwater resources. Part of the Atlas Mountains in North Africa, the Lebanon and Anti-Lebanon ranges between Syria and Lebanon, the Jebel Akhdar in Oman, parts of the Sierra Nevada and neighboring ranges in the United States' Southwest, have shallow aquifers that are exploited for their water.
Overexploitation can lead to the exceeding of the practical sustained yield. Along the coastlines of certain countries, such as Libya and Israel, increased water usage associated with population growth has caused a lowering of the water table and the subsequent contamination of the groundwater with saltwater from the sea. A beach provides a model to help visualize an aquifer. If a hole is dug into the sand wet or saturated sand will be located at a shallow depth; this hole is a crude well, the wet sand represents an aquifer, the level to which the water rises in this hole represents the water table. In 2013 large freshwater aquifers were discovered under continental shelves off Australia, North America and South Africa, they contain an estimated half a million cubic kilometers of "low salinity" water that could be economically processed into potable water. The reserves formed when ocean levels were lower and rainwater made its way into the ground in land areas that were not submerged until the ice age ended 20,000 years ago.
The volume is estimated to be 100 times the amount of water extracted from other aquifers since 1900. The system shows two aquifers with one aquitard between them, surrounded by the bedrock aquiclude, in contact with a gaining stream; the water table and unsaturated zone are illustrated. An aquitard is a zone within the Earth that restricts the flow of groundwater from one aquifer to another. An aquitard can sometimes, if impermeable, be called an aquiclude or aquifuge. Aquitards are composed of layers of either clay or non-porous rock with low hydraulic conductivity. Groundwater can be found at nearly every point in the Earth's shallow subsurface to some degree, although aquifers do not contain fresh water; the Earth's crust can be divided into two regions: the saturated zone or phreatic zone, where all available spaces are filled with water, the unsaturated zone, where there are still pockets of air that contain some water, but can be filled with more water. Saturated means; the definition of the water table is the surface where the pressure head is equal to atmospheric pressure.
Unsaturated conditions occur above the water table where the pressure head is negative and the water that incompletely fills the pores of the aquifer material is under suction. The water content in the unsaturated zone is held in place by surface adhesive forces and it rises above the water table by capillary action to saturate a small zone above the phreatic surface at less than atmospheric pressure; this is not the same as saturation on a water-content basis. Water content in a capillary fringe decreases with increasing distance from the phreatic surface; the capillary head depends on soil pore size. In sandy soils with larger pores, the head will be less than in clay soils with small pores; the normal capillary rise in a clayey soil can range between 0.3 and 10 m. The capillary rise of water in a small-diameter tube involves the same physical process; the water table is the level to which water will rise in a large-diameter pipe that goes down into the aquifer and is open to the atmosphere.
Aquifers are saturated regions of the subsurface that produce an economically feasible quantity of water to a well or spring. An aquitard is a zone within the Earth that restricts the flow of groundwater from one aquifer to another. A impermeable aquitard is called an aquiclude or aquifuge. Aquitards comprise layers of either clay or non-porous rock with low hydraulic conductivity. In mountainous areas, the main aquifers are unconsolidated alluvium, composed of horizontal layers of materials deposited by water processes, which in cross-section appear to be layers of alternating coarse and fine materials. Coarse materials, because of the high energy needed to move them, tend to be found nearer the source, whereas the fine-grained material will make it farther from the source (to the flatter parts of the basin
Dupont is a borough in the Greater Pittston area of Luzerne County, United States. The population was 2,711 as of the 2010 census; the community was incorporated as a borough in 1917. The community was renamed Dupont after Dupont Explosives, a company which made explosives for mining; these explosives were used throughout Northeastern Pennsylvania in the 20th centuries. Dupont Explosives closed after the advancement of technology in gathering coal. Dupont is located at 41°19′18″N 75°44′47″W. According to the United States Census Bureau, the borough has a total area of 1.5 square miles, all of it land. As of the census of 2000, there were 2,719 people, 1,228 households, 789 families living in the borough; the population density was 1,790.9 people per square mile. There were 1,354 housing units at an average density of 891.8 per square mile. The racial makeup of the borough was 99.23% White, 0.44% African American, 0.07% Asian, 0.26% from two or more races. Hispanic or Latino of any race were 0.11% of the population.
There were 1,228 households, out of which 18.9% had children under the age of 18 living with them, 46.7% were married couples living together, 13.4% had a female householder with no husband present, 35.7% were non-families. 32.6% of all households were made up of individuals, 17.8% had someone living alone, 65 years of age or older. The average household size was 2.21 and the average family size was 2.79. In the borough the population was spread out, with 15.9% under the age of 18, 6.3% from 18 to 24, 26.9% from 25 to 44, 24.5% from 45 to 64, 26.4% who were 65 years of age or older. The median age was 46 years. For every 100 females there were 88.8 males. For every 100 females age 18 and over, there were 84.3 males. The median income for a household in the borough was $32,317, the median income for a family was $39,250. Males had a median income of $28,431 versus $26,250 for females; the per capita income for the borough was $17,042. About 4.0% of families and 6.2% of the population were below the poverty line, including 10.3% of those under age 18 and 7.8% of those age 65 or over.
Theatre of Black Women was Britain's first black women's theatre company. It was founded by Bernardine Evaristo, Patricia Hilaire and Paulette Randall upon leaving the Rose Bruford College of Speech and Drama, where they had trained as actors and theatre-makers on the Community Theatre Arts course from 1979 to 1982; the course was a progressive, innovative drama course aimed at producing individuals who would be equipped to create their own theatre and be a force for change in society. The company, based in London, was forced to disband in 1988. Theatre of Black Women's aim was to produce plays by and about black British women at a time when parts for black women were non-existent in theatre, their first three short one-woman plays were staged at the Royal Court Theatre as part of their Young Writers Season in 1982. These were Evaristo's Tiger, Teeth Clenched Not To Bite, Hilaire's Hey Brown Girl and Randall's Chameleon; the pieces were taken to the 1982 international women's theatre festival at the Melkveg in Amsterdam, Holland.
Other plays included Silhouette by Hilaire. The company toured the UK with some appearances in Europe. Women who worked with the company include Joan Ann Maynard, who directed Chiaroscuro, Gail Ann Dorsey, who composed the music for Chiaroscuro. In addition to producing theatre, the company ran drama workshops for young black women nationally and in Europe. Theatre of Black Women was well received. In Spare Rib magazine 138, Maxine stated that during Silhouette, "on a Spartan stage the two women resurrect from silence and invisibility some of the history and experiences unique to the lives of Black women... An evocative language of poetry is used by the characters to explore the many subjects, which in different ways permeate both their lives". Listed in the 145th edition of Spare Rib in August 1984, Pyeyucca received positive reviews, as'it explores black woman and self-image and examines the ways the black woman has been portrayed through the media and how these stereotypes have their mark on black women today.
We ask the question to what extent we have absorbed white society’s and the black male’s definition of ourselves and how do we fight against the life-long conditioning that has us so narrowly defined.’ As a result, Pyeyucca has been described as "the rebel black spirit. She haunts Laura without rest: at home, through conformity at school, through the corridors of the ‘special school’ where Laura is sent when her divided psyche can no longer cope, and she liberates her. To what? We can not imagine; the point of Pyeyucca lies not in pragmatic details but in the wanting – the trapped black desire for liberation."