A spark gap consists of an arrangement of two conducting electrodes separated by a gap filled with a gas such as air, designed to allow an electric spark to pass between the conductors. When the potential difference between the conductors exceeds the breakdown voltage of the gas within the gap, a spark forms, ionizing the gas and drastically reducing its electrical resistance. An electric current flows until the path of ionized gas is broken or the current reduces below a minimum value called the "holding current"; this happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and breaking the filament of ionized gas. The action of ionizing the gas is violent and disruptive leading to sound and heat. Spark gaps were used in early electrical equipment, such as spark gap radio transmitters, electrostatic machines, X-ray machines, their most widespread use today is in spark plugs to ignite the fuel in internal combustion engines, but they are used in lightning arresters and other devices to protect electrical equipment from high-voltage transients.
The light emitted by a spark does not come from the current of electrons itself, but from the material medium fluorescing in response to collisions from the electrons. When electrons collide with molecules of air in the gap, they excite their orbital electrons to higher energy levels; when these excited electrons fall back to their original energy levels, they emit energy as light. It is impossible for a visible spark to form in a vacuum. Without intervening matter capable of electromagnetic transitions, the spark will be invisible. Spark gaps are essential to the functioning of a number of electronic devices. A spark plug uses a spark gap to initiate combustion; the heat of the ionization trail, but more UV radiation and hot free electrons ignite a fuel-air mixture inside an internal combustion engine, or a burner in a furnace, oven, or stove. The more UV radiation is produced and spread into the combustion chamber, the further the combustion process proceeds; the Space Shuttle Main Engine hydrogen oxygen propellant mixture was ignited with a spark igniter.
Spark gaps are used to prevent voltage surges from damaging equipment. Spark gaps are used in high-voltage switches, large power transformers, in power plants and electrical substations; such switches are constructed with a large, remote-operated switching blade with a hinge as one contact and two leaf springs holding the other end as second contact. If the blade is opened, a spark may keep the connection between spring conducting; the spark ionizes the air, which becomes conductive and allows an arc to form, which sustains ionization and hence conduction. A Jacob's ladder on top of the switch will cause the arc to rise and extinguish. One might find small Jacob's ladders mounted on top of ceramic insulators of high-voltage pylons; these are sometimes called horn gaps. If a spark should manage to jump over the insulator and give rise to an arc, it will be extinguished. Smaller spark gaps are used to protect sensitive electrical or electronic equipment from high-voltage surges. In sophisticated versions of these devices, a small spark gap breaks down during an abnormal voltage surge, safely shunting the surge to ground and thereby protecting the equipment.
These devices are used for telephone lines as they enter a building. Less sophisticated spark gaps are made using modified ceramic capacitors. A voltage surge causes a spark that jumps from lead wire to lead wire across the gap left by the sawing process; these low-cost devices are used to prevent damaging arcs between the elements of the electron gun within a cathode ray tube. Small spark gaps are common in telephone switchboards, as the long phone cables are susceptible to induced surges from lightning strikes. Larger spark gaps are used to protect power lines. Spark gaps are sometimes implemented on Printed Circuit Boards in electronics products using two spaced exposed PCB traces; this is an zero cost method of adding crude over-voltage protection to electronics products. Transils and trisils are the solid-state alternatives to spark gaps for lower-power applications. Neon bulbs are used for this purpose. A triggered spark gap in an air-gap flash is used to produce photographic light flashes in the sub-microsecond domain.
A spark radiates energy throughout the electromagnetic spectrum. Nowadays, this is regarded as illegal radio frequency interference and is suppressed, but in the early days of radio communications, this was the means by which radio signals were transmitted, in the unmodulated spark-gap transmitter. Many radio spark gaps include cooling devices, such as the rotary gap and heat sinks, since the spark gap becomes quite hot under continuous use at high power. A calibrated spherical spark gap will break down at a repeatable voltage, when corrected for air pressure and temperature. A gap between two spheres can provide a voltage measurement without any electronics or voltage dividers, to an accuracy of about 3%. A spark gap can be used to measure high voltage AC, DC, or pulses, but for short pulses, an ultraviolet light source or radioactive source may be put on one of the terminals to provide a source of
General Jang Jong-nam is a former defence minister of North Korea. He is believed to be in his 50s. Jang is believed to have played a role in the 2010 bombardment of Yeonpyeong, which killed four people. Jang was made colonel general on the occasion of Kim Il-sung's 99th birthday in April 2011, he delivered a speech on the first anniversary of Kim Jong-il's death in December 2012 pledging loyalty to Kim Jong-un and threatening to "ravine into their death pitfall when the hour of decisive battle comes". He was identified as general and commander of the forward-deployed 1st Army Corps of the Korean People's Army on that occasion. Jang was unexpectedly appointed minister of the People's Armed Forces in early May 2013, he is the third defence minister appointed by Kim Jong-un since taking control of North Korea in December 2011. He was replaced in June 2014
Rooster Blues is an American independent record label founded in 1980. The label is dedicated to blues music from the Mississippi Delta. Rooster Blues was co-founded by Jim O'Neal in Chicago, released 14 albums by South Side blues musicians. In 1986, O'Neal moved the label to Clarksdale and began focusing on the area's Delta blues performers. Lonnie Pitchford and Lonnie Shields helped in the construction of the new recording studio facilities. Over the next 12 years, Rooster Blues released albums by Booba Barnes, Carey Bell, Eddy Clearwater, Willie Cobbs, Larry Davis, John Littlejohn, Lonnie Pitchford, Lonnie Shields, Magic Slim, Super Chikan, James Thomas, Valerie Wellington. In 1998 the label suspended operations, in 1999 it was sold to Bottled MaJic Music. However, in 2000, Rooster Blues resumed operations and celebrated its 20th anniversary by releasing Willie King's Freedom Creek, as well as reissuing some classic recordings such as Grand Slam by Magic Slim. List of record labels
Carol Bonomo Albright is an American author and educator in the field of Italian-American studies. She has published many books and articles on the subject, taught classes at the University of Rhode Island and the Harvard University Extension School, she was editor-in-chief of Italian Americana, a peer-reviewed cultural/historical journal, for over 25 years. She was born in Greenwich Village, New York, attended St. Joseph Academy, her parents were immigrants from the Calabria region of Southern Italy. She earned an M. A. degree from Brown University, has received grants from the Danforth Foundation of Higher Education and the National Science Foundation for Medical Education. Albright's essays and other writings have appeared in many journals, such as PMLA, The Providence Journal, MELUS, the Journal of American Ethnic Studies. In 2004 she co-edited an annotated edition of two novels by Joseph Rocchietti, one of which and Oonalaska, is the earliest known novel by an Italian-American, she published a memoir in 2009.
Albright was editor-in-chief of Italian Americana from 1989 to 2015, served two terms as vice president of the American Italian Historical Association. Author: My Greenwich Village and the Italian American Community With Ned Balbo and Edvige Giunta, Padri: tre memoir italo americani Italian Immigrants Go West: The Impact of Locale on Ethnicity Italian American Autobiographies Editor: American Woman, Italian Style: Italian Americana's Best Writings on Women Wild Dreams: The Best of Italian Americana Republican Ideals in the Selected Literary Works of Italian-American Joseph Rocchietti, 1835/1845
Carlyle Township is one of fifteen townships in Clinton County, Illinois, USA. As of the 2010 census, its population was 3,932 and it contained 1,767 housing units. According to the 2010 census, the township has a total area of 20.67 square miles, of which 17.83 square miles is land and 2.84 square miles is water. Carlyle The township contains these cemeteries: Carlyle City Cemetery, Club Lake Grave Yard, Golder Grave Yard, Luebbers Grave Yard, McAllister Grave Yard, Poor Farm Cemetery and St. Mary's Catholic Cemetery. US Route 50 Illinois Route 127 Kaskaskia River Carlyle Lake Horseshoe Lake Clinton County Fairgrounds Eldon Hazlet State Recreation Area Royal Lake Resort Carlyle Community Unit School District 1 Illinois' 19th congressional district State House District 107 State Senate District 54 "Carlyle Township, Clinton County, Illinois". Geographic Names Information System. United States Geological Survey. Retrieved 2010-01-10. United States Census Bureau 2007 TIGER/Line Shapefiles United States National Atlas City-Data.com Illinois State Archives
Hainan Boying Football Club are a China League Two club. They are an association football club from Hainan; the Hainan Sport School Stadium is their home venue. Hainan Boying Football Club is a semi-professional association football club in PR China, they are among the most successful amateur football clubs in the country. In 2015, they reached the final rounds of the East Region amateur championship, they won their local league championship that year and the Chinese amateur division. Since 2016, they have been members of the China League Two; the club is located in the city of Haikou. That year, they changed their name from Hainan Seamen FC into Hainan Boying Seamen FC. In January 2017, Hainan Boying Seamen F. C. changed their name to Hainan Boying F. C.. In Season 2018 it changed its name to Hainan Haikou and ranked 16th, its best result but could not make it enter the elimination squad of the South District. 2015 Hainan Seamen F. C. 海南海汉 2016 Hainan Boying Seamen F. C. 海南博盈海汉 2017–2018 Hainan Boying F.