4.11.2009

Prime farmland - Wikipedia, the free encyclopedia - Sent Using Google Toolbar

Prime farmland - Wikipedia, the free encyclopedia

Prime farmland

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Prime farmland in 1997

Prime farmland, as a designation assigned by U.S. Department of Agriculture, is land that has the best combination of physical and chemical characteristics for producing food, feed, forage, fiber, and oilseed crops and is also available for these uses. It has the soil quality, growing season, and moisture supply needed to produce economically sustained high yields of crops when treated and managed according to acceptable farming methods, including water management. In general, prime farmlands have an adequate and dependable water supply from precipitation or irrigation, a favorable temperature and growing season, acceptable acidity or alkalinity, acceptable salt and sodium content, and few or no rocks. They are permeable to water and air. Prime farmlands are not excessively erodible or saturated with water for a long period of time, and they either do not flood frequently or are protected from flooding. [1]

Prime farmland tends to be well suited to "growing" houses. Thus prime farmland is also prime developable land and prone to conversion when in proximity to urban growth areas. USDA prime farmland designation helps growth management and resource conservation efforts in urban growth areas to use zoning and conservation easements to preserve prime farmland resources, maintain local economic diversity, and establish green belts. Nonprofit organizations like American Farmland Trust specialize in helping communities use these techniques.

Other designations used by USDA to complement Prime Farmland are Farmland of statewide importance, Farmland of local importance, and Unique farmland.

Unique farmland is land other than prime farmland that is used for the production of specific high value food and fiber crops. It has the special combination of soil quality, location, growing season, and moisture supply needed to produce economically sustained high quality and/or high yields of a specific crop when treated and managed according to acceptable farming methods. Examples of crops are tree nuts, olives, cranberries, citruses and other fruits, and vegetables. [2]

Farmland of statwide importance, or of local importance, is land other than prime farmland or unique farmland but that is also highly productive. Criteria for defining and delineating these lands are determined by the appropriate state or local agencies in cooperation with USDA. The significant difference is that although the criteria are not appropriate outside the state or local area, that these lands approach the productivity of lands in their area which meet criteria for prime farmland and unique farmland.[3]

[edit] See also

[edit] References

  1. ^ Soil Survey Staff (1993). "Soil Survey Manual". Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://soils.usda.gov/technical/manual/print_version/complete.html. Retrieved on 2006-08-30. 
  2. ^ Soil Survey Staff (1993). "Soil Survey Manual". Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://soils.usda.gov/technical/manual/print_version/complete.html. Retrieved on 2006-08-30. 
  3. ^ "National Soil Survey Handbook, title 430-VI". U.S. Department of Agriculture, Natural Resources Conservation Service. 2005. http://soils.usda.gov/technical/handbook/. Retrieved on 2006-08-30. 
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Puerta de Hierro - Wikipedia, the free encyclopedia - Sent Using Google Toolbar

Puerta de Hierro - Wikipedia, the free encyclopedia

Puerta de Hierro

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Puerta de Hierro tunel to Andares

Puerta de Hierro ("The Iron Door" in English) is one of Guadalajara's wealthiest districts. It includes the tallest building in Guadalajara, Aura Altitude, and also the prestigious Puerta de Hierro Medical Center. More than 10 buildings are presently being built. Andares mall is on Puerta de Hierro, and its an exclusive concept of the most expensive brands in the world. In Andares 7 apartment buildings will be constructed and a hotel. Residential buildings include the Torre de Hierro, Aura Altitude (tallest building in Guadalajara) and Torre Titatnium. The complex also includes Ferrari and Maserati car dealership.

Puerta de Hierro has been under construction since the 20th century.

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Ammar Siamwalla - Wikipedia, the free encyclopedia

Ammar Siamwalla

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Ammar Siamwalla

Ammar Siamwalla (Thai: อัมมาร สยามวาลา) is one of Thailand's most prominent economists. His ancestors were Indians who immigrated and founded a local stationary business, D.H.A. Siamwalla.

[edit] Education

Ammar attended St. Paul's School, Darjeeling in India, he went on to receive a B.Sc. in Economics from the London School of Economics and a Ph.D. in Economics from Harvard University. His teachers at Harvard were Alexander Gerschenkron, Wassily Leontief and Edward Chamberlin among others.

[edit] Career

He began his career as an assistant professor and research staff economist at Department of Economics, Yale University before moving to Faculty of Economics Thammasat University as a Rockefeller Scholar at the advice of Dr. Puey who was then dean of faculty. Like Dr. Puey and other scholars, Ammar left Thammasat after the October 6, 1976 student massacre in Thammasat University.

He was a visiting professor at the Food Research Institute, Stanford University as well as a Research Fellow with the International Food Policy Research Institute Washington, D.C.

He has been active at the Thailand Development Research Institute (TDRI) as a program director for agriculture and rural development, and as President of TDRI in 1990-1995.

Ammar is an expert in Thai Rice, Thai Agricultural Economics, and Development Economics. As one of the first Thai trained in neoclassical economics, he has contributed considerably in the development of modern economic discipline in Thailand.

Currently, he holds a post as a distinguished scholar of TDRI. He is still active in the economic debates and periodically gives commentaries to the public. He is known to be a harsh critic of former P.M.Thaksin's populist policies such as 30 Baht universal heathcare program.

[edit] External links


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Euler characteristic - Wikipedia, the free encyclopedia - Sent Using Google Toolbar

Euler characteristic - Wikipedia, the free encyclopedia

Euler characteristic

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In mathematics, and more specifically in algebraic topology and polyhedral combinatorics, the Euler characteristic (or Euler-Poincaré characteristic) is a topological invariant, a number that describes a topological space's shape or structure regardless of the way it is bent. It is commonly denoted by χ (Greek letter chi).

The Euler characteristic was originally defined for polyhedra and used to prove various theorems about them, including the classification of the Platonic solids. Leonhard Euler, for whom the concept is named, was responsible for much of this early work. In modern mathematics, the Euler characteristic arises from homology and connects to many other invariants.

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Lisa Ysaye Tarleau - Wikipedia, the free encyclopedia

Lisa Ysaye Tarleau

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 This article is an orphan, as few or no other articles link to it. Please introduce links to this page from other articles related to it. (February 2009)

Lisa Ysale Tarleau (1885-October 9, 1952), also known as Lisa Ysaye, was an early 20th century female writer whose only work was The Inn of Disenchantment. This book is a collection of short stories utilizing the same two characters - "The Lady in Blue" and "The Gentleman in Gray" - who appear in most of them. The stories are structured as a series of romantic discussions.

Disenchantment was published in 1917 by the Houghton Mifflin Company (Boston, New York), and Riverside Press (Cambridge). Tarleau's stories were also reprinted in major magazines of the day including The Nation (Volume 105, Issue 2725, September 20, 1917) and The Atlantic Monthly (in 1919). In 1925, her short story "Loutre" received a prize from Harper's Magazine. Several were also included in The Fireside Book of Romance (circa 1948), edited by C. Edward Wagenknecht, a Professor Emeritus who taught English at Boston University from 1947 to 1968. Virginia Woolf's story "The Mark on the Wall" was also included in the anthology. She also wrote a number of scripts for radio and film and worked as a translator for the US military during World War II.

She had four sons and one daughter.

[edit] References


United States  This article about an American short story writer is a stub. You can help Wikipedia by expanding it.
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4.10.2009

Cecilio Apostol - Wikipedia, the free encyclopedia - Sent Using Google Toolbar

Cecilio Apostol - Wikipedia, the free encyclopedia

Cecilio Apostol

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Cecilio Apostol
Born December 22, 1877(1877-12-22)
Santa Cruz, Manila, Philippines
Died September 8, 1938 (aged 60)
Caloocan, Rizal, Philippines
Nationality Filipino
Occupation poet

Cecilio Apostol (November 22, 1877—September 8, 1938) was a Filipino poet. His poems were once used to teach the Spanish language under the Republic Act No. 1881.[1]

He was born in Santa Cruz, Manila and studied at the Ateneo de Manila where he finished his Bachelor of Arts, before studying law at the University of Santo Tomas. During the early years of American occupation he worked as a journalist for the revolutionary newspapers Independence, The Brotherhood, The Union, Renaissance and Democracy. His pseudonym on his work at the La Independencia, under Antonio Luna, was Catulo.[2] He later joined the Nacionalista Party which wanted the independence of the Philippines from the United States.[3] He was a member of the Philippine Academy from 1924 until his death. Apostol wrote in English and Spanish, and composed poems that demonstrated his mastery of Spanish. He composed the poem Al Heroes Nacional (To the National Hero) which is dedicated to Jose Rizal.[4] In the book of poems, Pentélicas, he described landscapes evoking a vivid images. He died in Caloocan, Rizal.

[edit] References

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Electron–positron annihilation - Wikipedia, the free encyclopedia - Sent Using Google Toolbar

Electron–positron annihilation - Wikipedia, the free encyclopedia

Electron–positron annihilation

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Naturally occurring electron-positron annihilation as a result of beta plus decay
Feynman Diagram of Electron-Positron Annihilation

Electron-positron annihilation occurs when an electron and a positron (the electron's anti-particle) collide. The result of the collision is the conversion of the electron and positron and the creation of gamma ray photons or, less often, other particles. The process must satisfy a number of conservation laws, including:

As with any two charged objects, electrons and positrons may also interact with each other without annihilating, in general by elastic scattering.

Contents

[hide]

[edit] Low energy case

There are only a very limited set of possibilities for the final state. The most likely is the creation of two or more gamma ray photons. Conservation of energy and linear momentum forbid the creation of only one photon. In the most common case, two photons are created, each with energy equal to the rest energy of the electron or positron (511 keV)[1] . A convenient frame of reference is that in which the system has no net linear momentum before the annihilation; thus, after collision, the gamma rays are emitted in opposite directions. It is also common for three to be created, since in some angular momentum states, this is necessary to conserve C parity.[2] It is also possible to create any larger number of photons, but the probability becomes lower with each additional photon because these more complex processes have lower quantum mechanical amplitudes.

Since neutrinos also have a smaller mass than electrons, it is also possible — but exceedingly unlikely — for the annihilation to produce one or more neutrino/antineutrino pairs. The same would be true for any other particles, which are as light, as long as they share at least one fundamental interaction with electrons and no conservation laws forbid it. However, no other such particles are known.

[edit] High energy case

If the electron and/or positron have appreciable kinetic energies, other heavier particles can also be produced (e.g. D mesons), since there is enough kinetic energy in the relative velocities to provide the rest energies of those particles. It is still possible to produce photons and other light particles, but they will emerge with higher energies. However, if a photon - photon reaction occurs under the presence of ultraviolet light, an antimatter particle may be emitted; this process is known as the Kerr phenomenon, and was discovered in 2007 by Andrew Kerr while working at the NRU reactor in Chalk River, Ontario.[citation needed]

At energies near and beyond the mass of the carriers of the weak force, the W and Z bosons, the strength of the weak force becomes comparable with electromagnetism.[2] This means that it becomes much easier to produce particles such as neutrinos that interact only weakly.

The heaviest particle pairs yet produced by electron-positron annihilation in particle accelerators are W+/W− pairs. The heaviest single particle is the Z boson. The driving motivation for constructing the International Linear Collider is to produce Higgs bosons in this way.

[edit] Practical uses

This process is the physical phenomenon relied on as the basis of PET imaging. Also used as a method of measuring the Fermi surface and Band structure in metals.

[edit] Reverse reaction

The reverse reaction is a form of matter creation governed by two-photon physics.

[edit] References

  1. ^ William B. Atwood, Peter F. Michelson and Steven Ritz (2008). "Una Ventana Abierta a los Confines del Universo". Investigación y Ciencia 377: 24–31(Spanish). 
  2. ^ a b David Griffiths, "Introduction to Elementary Particles", ISBN 0471603864

[edit] See also

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