The light-water reactor is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator – furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reactors are the most common type of nuclear reactor, light-water reactors are the most common type of thermal-neutron reactor. There are three varieties of light-water reactors: the pressurized water reactor, the boiling water reactor, the supercritical water reactor. After the discoveries of fission, moderation and of the theoretical possibility of a nuclear chain reaction, early experimental results showed that natural uranium could only undergo a sustained chain reaction using graphite or heavy water as a moderator. While the world's first reactors were reaching criticality, uranium enrichment began to develop from theoretical concept to practical applications in order to meet the goal of the Manhattan Project, to build a nuclear explosive. In May 1944, the first grams of enriched uranium produced reached criticality in the low power reactor at Los Alamos, used to estimate the critical mass of U235 to produce the atomic bomb.
LOPO cannot be considered as the first light-water reactor because its fuel was not a solid uranium compound cladded with corrosion-resistant material, but was composed of uranyl sulfate salt dissolved in water. It is however the first aqueous homogeneous reactor and the first reactor using enriched uranium as fuel and ordinary water as a moderator. By the end of the war, following an idea of Alvin Weinberg, natural uranium fuel elements were arranged in a lattice in ordinary water at the top of the X10 reactor to evaluate the neutron multiplication factor; the purpose of this experiment was to determine the feasibility of a nuclear reactor using light water as a moderator and coolant, cladded solid uranium as fuel. The results showed that, with a enriched uranium, criticality could be reached; this experiment was the first practical step toward the light-water reactor. After World War II and with the availability of enriched uranium, new reactor concepts became feasible. In 1946, Eugene Wigner and Alvin Weinberg proposed and developed the concept of a reactor using enriched uranium as a fuel, light water as a moderator and coolant.
This concept was proposed for a reactor whose purpose was to test the behavior of materials under neutron flux. This reactor, the Material Testing Reactor, was built in Idaho at INL and reached criticality on March 31, 1952. For the design of this reactor, experiments were necessary, so a mock-up of the MTR was built at ORNL, to assess the hydraulic performances of the primary circuit and to test its neutronic characteristics; this MTR mock-up called the Low Intensity Test Reactor, reached criticality on February 4, 1950 and was the world's first light-water reactor. After the end of World War II the United States Navy started a program under the direction of Captain Hyman Rickover, with the goal of nuclear propulsion for ships, it developed the first pressurized water reactors in the early 1950s, led to the successful deployment of the first nuclear submarine, the USS Nautilus. The Soviet Union independently developed a version of the PWR in the late 1950s, under the name of VVER. While functionally similar to the American effort, it has certain design distinctions from Western PWRs.
Researcher Samuel Untermyer II led the effort to develop the BWR at the US National Reactor Testing Station in a series of tests called the BORAX experiments. PIUS, standing for Process Inherent Ultimate Safety, was a Swedish design designed by ASEA-ATOM, it is a concept for a light-water reactor system. Along with the SECURE reactor, it relied on passive measures, not requiring operator actions or external energy supplies, to provide safe operation. No units were built. In 2020 Energy Impact Center announced publication of an open-sourced engineering design of a 100 MW PWR reactor called OPEN-100; the family of nuclear reactors known as light-water reactors and moderated using ordinary water, tend to be simpler and cheaper to build than other types of nuclear reactors. LWRs can be subdivided into three categories – pressurized water reactors, boiling water reactors, supercritical water reactors; the SCWR remains hypothetical as of 2009. The leaders in national experience with PWRs, offering reactors for export, are the United States, the Russian Federation, the Republic of France, Japan.
The leaders in national experience with BWRs, offering reactors for export, are the United States and Japan, with the alliance of General E
Endiandra muelleri is a rainforest tree of eastern Australia. Its habitat is in warm temperate rainforests on poorer soils. Distributed from the Allyn River in the Barrington Tops region in the south to Kroombit Tops to the north in central Queensland. Common names include Mueller's green-leaved rose walnut; the tree is not a walnut. It is named after Ferdinand von Mueller. There are two types of Endiandra muelleri, this plant Endiandra muelleri muelleri and the endangered Endiandra muelleri bracteata. For the differences in the sub-species, see Endiandra muelleri bracteata. Endiandra muelleri subsp. Muelleri is a tree reaching 30 metres tall with a trunk diameter of 75 cm; the base of the tree may be flanged. The brown bark is irregular, with craters and loose plates of bark. Leaf bearing twigs are green. New shoots fawn coloured hairs. Leaves are 3 to 5 cm wide. Green and smooth on both surfaces, paler beneath. Leaves broad lanceolate to elliptic in shape with a leaf stem from 3 to 6 mm long. One to four hairy tufts or bumps are seen on the underside of the leaf, next to the joining of leaf veins and mid-vein on Endiandra muelleri subsp.
Muelleri. Greenish pink flowers form on panicles from the leaf axils in the months of November to January. With Endiandra muelleri subsp. Muelleri, the perianth lobes are hairy on the outside; the fruit is 15 to 25 mm in length. Maturing from March to April; the fruit is eaten by a variety of birds, including the rose-crowned fruit dove, regent bowerbird, superb fruit-dove, wompoo fruit-dove. It is advisable to remove the flesh from the seed before sowing. Germination occurs after around two months
Enrico di Borgogna is an opera eroica or "heroic" opera in two acts by Gaetano Donizetti. Bartolomeo Merelli, wrote the Italian libretto based on Der Graf von Burgund by August von Kotzebue. Enrico di Borgogna was the third opera the first to be performed, it premiered on 14 November 1818 at the Teatro San Luca in Venice. In spite of difficulties at the premiere, the critic of Nuovo osservatore veneziano noted of Donizetti that "one cannot but recognize a regular handling and expressive quality in his style. For these, the public wanted to salute Signor Donizetti on stage at the end of the opera". For the first time in 192 years, the opera was presented at the Vadstena Academy in Sweden in July/August 2012; the king has murdered by his own brother. The king's bodyguards and Brunone, manage to escape with Enrico, the first-born son of the king and the rightful heir to the throne. During Pietro's escape, his wife is killed. Brunone stays in the castle. Time: The Middle Ages Place: Burgundy Nicola, the young shepherd, his friends find the old man Pietro weeping before by his wife's grave, as he has done many times.
They try to cheer him up, after that, carry on with their work, leaving Pietro alone. Enrico, now a young man, is on his way home from fishing, he is thinking about the girl of his dreams, whom he has seen several times in the mountains. Brunone arrives at Pietro's cabin and tells him that the king is dead and that his weak son Guido has taken his place, he explains. When Enrico arrives and learns the truth, they give him his father's sword and he decides to accept his fate. In the castle the new king Guido and his jester Gilberto are planning Guido's marriage with Elisa, but she has just lost her father and is still mourning; the jester Gilberto speaking to Guido says that merit are overrated. Guido asks the jester to tell him. Gilberto flatters him, but Guido is not satisfied until he learns that some of the people are complaining. Elisa enters in the company of Guido's bodyguards who invites her to rejoice in the happiness of marriage. Elisha is unhappy, she hope to see Enrico again. When she is left alone with her lady in waiting, she confesses to her of her love.
Guido forces Elizabeth to change her mourning clothes into the wedding attire and appeals to her to give in to his great love for her. She replies that he can force her into marriage but her heart will never change; the wedding procession has gathered in the square. Enrico and Pietro are unaware of the wedding. Elisa faints. Pietro and Brunone furiously try to stop Enrico's jealousy from revealing himself as her true love. A heavy storm occurs, Guido is forced to postpone the wedding. Brunone and Pietro reveal to the insurgents. Enrico has slipped into the castle to see Elisa for the last time. Enrico meets jester Gilberto. Gilberto promises to show Enrico to Elisa's room. Elisa enters. Guido is threatening her with death; the threat is ineffective. Guido leaves the room. Gilberto shows Enrico to Elisa's room with the warning that women are in the world to create disorder. Enrico and Elisa meet. At first, he rejects her declaration; when he learns about her promise to her father, he understands the two reunite.
Guido rushes into the room. At the same time Brunone and Nicola entered the castle; the truth about Enrico's birth is revealed to Elisa. Guido orders the confused guards to arrest the four but the guards put down their weapons and Enrico wins. Guido is terrified. People storms in and want to take revenge on Guido, but Enrico admonishes his people with a message of peace. A Hundred Years of Italian Opera contains Enrico's Act I: Recitative and Cavatina, Elisa! Elisa! Oh! Me infelice Care aurette che spiegate, sung by Della Jones. Opera Rara ORCH103. Alessandro de Marchi conducted the Academia Montis Regalis with the Coro Donizetti Opera with soloists Anna Bonitatibus, Sonia Ganassi, Levy Segkapane, Francesco Castoro, Luca Tittoto. Notes Cited sources Ashbrook and Sarah Hibberd, in Holden, The New Penguin Opera Guide, New York: Penguin Putnam. ISBN 0-14-029312-4. Pp. 224 – 247. Osborne, The Bel Canto Operas of Rossini and Bellini, Oregon: Amadeus Press. ISBN 0-931340-71-3 Weinstock, Herbert and the World of Opera in Italy and Vienna in the First Half of the Nineteenth Century, New York: Pantheon Books.
LCCN 63-13703Other sources Allitt, John Stewart, Donizetti: in the light of Romanticism and the teaching of Johann Simon Mayr, Shaftesbury: Element Books, Ltd. Ashbrook, William, "Donizetti, Gaetano" in Stanley Sadie, The New Grove Dictionary of Opera, Vol. One. London: MacMillan Publishers, Inc. ISBN 0-333-73432-7 ISBN 1-56159-228-5 Loewenberg, Alfred (1
The Porsche 550 was a racing sports car produced by Porsche from 1953 to 1956. In that time only 90 Porsche 550s were produced, but it established dominance in the 1.1- and 1.5- liter classes. The Porsche 550 is a mid-engine car with an air-cooled four-cylinder engine, following the precedent of the 1948 Porsche 356/1 prototype designed by Ferry Porsche; the mid-engine racing design was further developed with Porsche's 718 model. The Porsche 550 has a solid racing history; the 550 Spyder would finish top 3 in its class. Each Spyder was customized to be raced; the Type 550/550 A is powered by an all aluminium 1,498 cc aspirated air-cooled 4 cylinder boxer engine known as the "Fuhrmann Engine". Its valvetrain uses double overhead camshafts on each cylinder bank, driven by vertical shafts, actuating 2 valves per cylinder; the engine is equipped with twin 2-barrel Solex PJJ Carburetors and dual ignition with two separate ignition manifolds and two ignition coils as well as two double fall gasifiers.
In its first version produced 110 PS at 6200 rpm and a maximum torque of 121 N⋅m at 5000 rpm. The engine of the 550 is mounted in front of the rear axle making it mid-engined; this gives it a more balanced weight distribution, allows for neutral handling. On the other hand, the low mass moment of inertia about the vehicle's vertical axis can lead to a sudden, difficult to control rotation of the car. Ferdinand Porsche had pioneered this design layout with the Auto Union Grand Prix car of the 1930s; the first 550 had a synchronized 4-speed gearbox. Starting in 1956, a five-speed gearbox was used, but its first gear only had to start and had to be placed over a barrier and not synchronized. Excessive slip to the drive wheels in corners was prevented by a limited slip differential. Inspired by the Porsche 356, created by Ferry Porsche, as well as spyder prototypes built and raced by Walter Glöckler starting in 1951, the factory decided to build a car designed for use in auto racing; the Porsche 550 Spyder was introduced at the 1953 Paris Auto Show.
The 550 was low to the ground, in order to be efficient for racing. In fact, former German Formula One racer Hans Herrmann drove it under closed railroad crossing gates during the 1954 Mille Miglia; the first three hand built. The first raced as a roadster at the Nurburgring Eifel Race in May 1953 winning its first race; that year the 550 took class wins in the 24 Hours of Le Mans and the Carrera Panamericana. From 1953 to 1957, the Porsche works team evolved and raced the 550 with outstanding success and was recognized wherever it appeared; the silver Werke cars were painted with spears of different colors on the rear fenders to aid recognition from the pits. Hans Herrmann’s famous ‘red-tail’ car No 41 went from victory to victory. For such a limited number of 90 prototype and customer builds, the 550 Spyder was always in a winning position finishing in the top three results in its class. During its tenure with the works team it was challenged only twice among the smaller cars at the 24 Hours of Le Mans, with a 1.5 liter O.
S. C. A. Finishing ahead but disqualified in the 1954 race and a 1.1 liter Lotus Eleven trailing the 1.5 liter winning 550 by one lap in the 1957 race. The 1956 version, the 550A with a lighter and more rigid spaceframe chassis, gave Porsche its first overall win in a major sports car racing event, the 1956 Targa Florio. During this era Porsche was the first car manufacturer to get race sponsorship, through Fletcher Aviation, who Porsche was working with to design a light aircraft engine and Telefunken and Castrol; the 550 was raced by privateers, who kept the type in competition after the works team had moved on to the 718 in 1957. The 550 was both a road and track car and it was common for privateers to drive it to the race track, race it drive it home; each Spyder was assigned a number for the race and had gumballs positioned on doors and rear, to be seen from any angle. On some 550s owned by privateers, a crude hand written number scrawled in house paint served the purpose. Cars with high numbers assigned such as 351, raced in the 1000 mile Mille Miglia, where the number represented the start time of 3.51am.
On most occasions, numbers on each Spyder would change for each race entered, which today helps identify each 550 by chassis number and driver in period black and white photos. Its successor from 1957 onwards, the Porsche 718 known as the RSK was more successful; the Spyder variations continued through the early 1960s, the RS 60 and RS 61. The Porsche Boxster S 550 Spyder is a modern mid-engined sports car that pays tribute to the 550. One of the first 90 Porsche 550s built was James Dean's, numbered 130, which crashed at the CA Rte. 46/41 Cholame Junction on September 30, 1955, resulting in Dean's death. As Dean was finishing up Giant’s filming in September, 1955, he traded in his 356 Porsche Super Speedster at Competition Motors, for a new 1955 Porsche 550 Spyder on September 21st, entered the upcoming Salinas Road Race event scheduled for October 1 and 2. According to Lee Raskin, Porsche historian and author of James Dean At Speed, Dean asked custom car painter and pin striper Dean Jeffries to paint "Little Bastard"
Rhett Matthew Bomar is a former American football quarterback. He was drafted by the New York Giants in the fifth round of the 2009 NFL Draft, he played college football at the University of Sam Houston State. He was a member of the Minnesota Vikings and Oakland Raiders; as a boy, Bomar lived in Groesbeck, Texas where his father Jerry coached and was the ball boy for their State Championship team in 1991. Coached by his father at Grand Prairie High School, now the athletic director and head coach of the high school football team in Beeville Texas. Bomar was a starter for three years, he was ranked as the nation's No. 1 high school quarterback of 2004 by the recruiting services Rivals.com and Scout.com and was compared to former NFL great John Elway. He rushed for 547 yards as a senior. Bomar committed to Oklahoma in February 2004, he played in the 2004 U. S. Army All-American Bowl. Bomar was an athletic director and the head coach of the football team at the Freer Early College High School, in Freer, Texas until March 2017.
He holds the position of offensive coordinator at Alief Taylor High School in Houston, Texas. In the spring of 2017 it was announced that Bomar would follow former Alief Taylor defensive coordinator Cedric Hardeman to Conroe to become Hardeman’s offensive coordinator with the Tigers. Bomar became the starter by the 2nd game 2005 season, his season started while he adjusted to college football, but his game improved throughout the season. He was named the Most Valuable Player of the Holiday Bowl. On August 2, 2006, Bomar was dismissed from the team by OU head coach Bob Stoops, it was reported that he was paid for work at Big Red Sports and Imports, a car dealership owned by a major University of Oklahoma donor, but that he did not complete the work, a violation of NCAA rules. Senior Paul Thompson began the year as starting quarterback, backed up by true freshman Sam Bradford and junior college transfer Joey Halzle. Bomar entered spring practice as the starting quarterback for the 2007 Bearkats, with two years of collegiate eligibility remaining.
He played nine games the first year for the Bearkats before injuring his knee on November 3, 2007 against Nicholls State. “Rhett brings a lot of athleticism to the quarterback position that we haven’t had,” SHSU coach Todd Whitten told the Huntsville Item. “He's going to get a chance to get a lot of reps this spring. We feel like our offense has the chance to make a lot of big plays next year.”Bomar started all 10 games in 2008 for Sam Houston State as the Bearkats went 4–6 on the season. He completed his college career as Sam Houston's all-time leader in passing with 5,564 yards in 19 games and career leader in total offense with 6,159 yards, he was a two-time All-Southland Conference selection and ended the 2008 season ranked No. 2 in NCAA Division I Football Championship Subdivision total offense and No. 4 in passing offense. Bomar passed for more than 300 yards in nine games during his Bearkat career, he threw for passes of more than 50 yards 10 times, including his longest of 80 yards. He is one of only 11 players in NCAA FCS history to throw for more than 300 yards and rush for more than 100 yards in a single game.
He was selected as a finalist for the Walter Payton Award given to the top player in the Football Championship Subdivision. In the 2009 NFL Draft, Bomar was drafted by the New York Giants as the 15th pick of the 5th round. Bomar on June 24, 2009 signed a four-year contract, including a $185,183 signing bonus, he was waived on September 5, 2009, re-signed to the practice squad on September 6. Bomar was promoted to the active roster on December 31, 2009. On September 4, 2010, Bomar was waived by the Giants. Following an injury to Giants quarterback Jim Sorgi, Bomar was expected to take over the role as backup quarterback, but on September 3, 2010, the Giants acquired Sage Rosenfels from the Minnesota Vikings to step in at the position, making Bomar expendable. On the following day, September 5, the Giants re-signed Bomar to the team's practice squad. Bomar was signed by the Minnesota Vikings off of the Giants' practice squad on December 21, 2010, made him the team's third-string quarterback for the final two games of the season.
The Grand National Cross Country Series is an American motorcycle racing series. The off-road race series was founded by Dave Coombs in 1975 and is sanctioned by the American Motorcyclist Association; the competition is similar to motocross but, instead of using an enclosed race track, it features extended cross-country, off-road courses of 8 to 12 miles in length and competitions lasting up to 3 hours. GNCC races are physically demanding, leading as many as 2,200 riders through tracks ranging from woods, to hills, rocks, motocross track sections and more; the series has classes for ATV and eMTB vehicles. GNCC Racing is open to both professional and amateur racers in a variety of skill level and age classes; the current presenting sponsor is Specialized Bicycle Components. The series began in 1975 when Dave Coombs was contacted by a preacher from a church in a small West Virginia town; the preacher wanted to help the economy of his struggling town by hosting a motorcycle race. Dave Coombs saw major potential in the land and thought that a grand prix style race through the town and surrounding country side would be special enough to bring visitors to the town.
Coombs named this race The Blackwater 100. The name "Blackwater" originated from nearby Blackwater Falls and the Blackwater River, while 100 for the number of miles in the race; the land was rugged, which would make the race itself one would be difficult for riders and their machines. The race became popular when Dave invited a group of magazine editors from California, who went back and wrote about their experiences with the rugged race. Blackwater would become known as "America's Toughest Race". Dave promoted the first AMA National Hare Scramble, held at High Point Raceway in 1979. With the popularity of this event and the Blackwater, the Wiseco 100 Miler Series was born; the series would evolve into the GNCC series beginning with the 1984 season. The GNCC series began experiencing more growth when three-wheelers were added in 1983, four-wheelers replaced them a few years later; the famous Blackwater 100 was shut down after the 1993 event, but by this point the GNCC series had earned the reputation as being the Premier Offroad Racing Series in America.
Throughout the 90s the series would still grow more. With domination on the bike side by riders such as Scott Summers, Scott Plessinger and Rodney Smith, while Barry Hawk dominated the ATV side, the series gained more mainstream coverage in various media; the series patriarch, Dave Coombs, died in 1998 but Big Dave's family stepped up to continue the success of the series. His son-in-law, Jeff Russell, the 1991 AMA National Enduro Champion, is today's GNCC Trail Boss. GNCC Racing has evolved from small, regional races to professional-grade events that attract professional and amateur riders from across the world. Growth in the professional ranks prompted the changes from one single "Pro" class to multiple professional rank classes beginning in 2007. Professional ATV classes consist of the premier "XC1 Pro ATV" class and the "XC2 Pro-Am ATV" class to serve as a stepping stone for riders moving out of the amateur classes. Professional motorcycle classes consist of the "XC1 Open Pro" class for any size motorcycle, the "XC2 250 Pro" class for 250cc motorcycles and the "XC2 125 Pro-Am" class reserved for 125cc 2-stroke motorcycles.
Over the years the series has been contested by thousands of different riders across the world. Each year an Overall Champion is crowned for ATVs. Official website List of GNCC Events from 1984 – 2012 GNCC on Facebook