In physics, the reduced mass is the "effective" inertial mass appearing in the two-body problem of Newtonian mechanics. It is a quantity. Note, that the mass determining the gravitational force is not reduced. In the computation one mass can be replaced with the reduced mass, if this is compensated by replacing the other mass with the sum of both masses; the reduced mass is denoted by μ, although the standard gravitational parameter is denoted by μ. It has the dimensions of mass, SI unit kg. Given two bodies, one with mass m1 and the other with mass m2, the equivalent one-body problem, with the position of one body with respect to the other as the unknown, is that of a single body of mass μ = 1 1 m 1 + 1 m 2 = m 1 m 2 m 1 + m 2, where the force on this mass is given by the force between the two bodies; the reduced mass is always less than or equal to the mass of each body: μ ≤ m 1, μ ≤ m 2 and has the reciprocal additive property: 1 μ = 1 m 1 + 1 m 2 which by re-arrangement is equivalent to half of the harmonic mean.

In the special case that m 1 = m 2: μ = m 1 2 = m 2 2 If m 1 ≫ m 2 μ ≈ m 2. The equation can be derived. Using Newton's second law, the force exerted by a body on another body is: F 12 = m 1 a 1 The force exerted by particle 1 on particle 2 is: F 21 = m 2 a 2 According to Newton's third law, the force that particle 2 exerts on particle 1 is equal and opposite to the force that particle 1 exerts on particle 2: F 12 = − F 21 Therefore: m 1 a 1 = − m 2 a 2 ⇒ a 2 = − m 1 m 2 a 1 The relative acceleration arel between the two bodies is given by: a r e l:= a 1 − a 2 = a 1 = m 2 + m 1 m 1 m 2 m 1 a 1 = F 12 μ Note that, the relative acceleration a r e l is equal to the acceleration of the separation x r e l between the two particles. A r e l = a 1 − a 2 = d 2 x 1 d t 2 − d 2 x 2 d t 2 = d 2 d t 2 = d 2 x r e l d t 2 {\d

Hamdi Ali Abdul Wahab Al Banbi was an Egyptian businessman and politician who served as oil minister from 1991 to 1999. Banbi studied petroleum engineering at Texas A&M University and graduated in 1963. Banbi was an engineer by training, he served as the chairman of the Egyptian General Petroleum Corporation until 1991. He was appointed oil minister on 20 May 1991 to the cabinet headed by prime minister Atef Sedki. Banbi replaced Abdel Hadi Qandil as oil minister. Shortly after his appointment, Banbi modified oil pricing of Egypt and reshuffled officials at the ministry. Banbi was a member of the National Democratic Party and he won a seat in Shebin El Kom, provincial capital of the Monufia governorate, in the mid-term Shura Council elections held in June 1998, he served as oil minister in the first cabinet of prime minister Kamal Ganzouri. Banbi was in office until 5 October 1999. Sameh Fahmi succeeded him as oil minister. After leaving office, Banbi became the coordinator of the energy committee for the national economics and production authority in Egypt.

He was the president of the Arab society for mining and petroleum and the Egypt's gas society. In addition he was a board member of the Egypt's engineering society. Banbi founded TAQA Arabia in 2006, serves as the chairman of the firm. Banbi was a member of the Petroleum Engineering Academy of Distinguished Graduates at Texas A&M University

The Canadian Forces Leadership and Recruit School is located at the Saint-Jean Garrison in Saint-Jean-sur-Richelieu, Quebec. The two main courses offered at CFLRS are the Basic Military Qualification for Regular Force Non Commissioned Members, the Basic Military Officer Qualification for Regular Force Officers; the basic training courses can be physically and psychologically demanding, recruits undergo tremendous physical and mental stress during the training. Furthermore, the School is responsible for the Distance Learning portion of the Canadian Forces Primary Leadership Qualification. Unlike the BMOQ and BMQ courses which are aimed at recruits and officer cadets, the PLQ is for more senior military members; the School is responsible for the Canadian Armed Forces Junior Officer Development program which exposes Junior Officers from the Regular and Reserve Forces to a general and standardized body of foundational knowledge through seven Distance Learning modules. The school's motto is: "Apprendre a servir" - French for "learn to serve".

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Rockcliffe Mansion is located in Hannibal and was built in 1898 by John J. Cruikshank, Jr. a descendant of Scottish immigrants, whose fortune was founded on lumber. He erected the residence on Bird Street, it came to be acknowledged as the most imposing and costly residential structure in that part of the state of Missouri. "By reason of its location on a high, rocky eminence, overlooking the entire city, it termed'Rock Cliff', is one of the many attractions of the city invariably viewed by strangers and tourists visiting Hannibal." It is located in the Maple Avenue Historic District. Rockcliffe is a massive 13,500-square-foot Colonial Revival/Georgian Style residence, "with large columns and porches circling the building," built of double-brick wall construction, designed by the St. Louis firm of Barnett, Haynes & Barnett, the firm which planned "the Governor's Mansion in Jefferson City, the St. Louis Cathedral, other fine buildings.""The staid exterior featuring a monumental double-height portico with Corinthian columns gives no hint of the richness within - an interior embellished with exotic woods, South African pink marble, Tiffany glass.

The owner's business connection in lumber and construction helped control building costs, which are reported to have been $125,000. A St. Louis newspaper cited it as the finest residence in the state soon after moved into the house in 1900; when the family moved out in 1924 after Cruikshank's death, no one else moved in. Arranged around the central hall are grand public rooms meant for entertaining. To one side is the Reception Room, with gilded wallpaper, quarter-sawn oak paneling, Tiffany fixtures, furnished with a lemonwood sideboard and olivewood reception table commissioned in Florence; the pink and green Music Room is anchored at each end by a grand piano. Friend and writer Mark Twain addressed 300 guests and Hannibal citizens from the double staircase the second floor during his visit in 1902; the Moorish Room provides the de rigueur eclecticism embraced by the period." The house has 10 fireplaces. Cruikshank prided himself on the structural and decorative use of wood on the property, employed mahogany and walnut throughout the house.

Greek Revival and Art Nouveau decorative motifs recur in various rooms. "Most of the rooms had individual thermostatic heat control from a central coal burning steam heating plant. The building had electric lighting, but auxiliary gas lights were installed. Rock walls were constructed as part of the landscaping of the property." "Rockcliffe was purchased by private individuals in 1967. During the house's four-decade vacancy it had settled less than half of an inch. After the restoration, a Cruikshank daughter returned some of the original furnishings and lace, to the property which she had stored for decades. Rockcliffe is in the National Register of Historic Places and is open to the public for tours and special events." Rockcliffe still boasts its original furniture, wall coverings, lighting fixtures, bathroom fixtures, books and personal artifacts of the Cruikshank family. Ongoing restoration is aimed at maintaining the mansion in its original turn-of-the-century state; the mansion is open for guided tours daily.

Bed and Breakfast accommodations are available. Rockcliffe Mansion

The Oktyabrskiy Big Concert Hall is a theatre located in Saint Petersburg, Russia. It hosts variety actors, rock musicians, dance and ballet collectives. Located in the Greek Square, it opened October 1967, inaugurated 50 years after the October Revolution; the director of the hall, since 1988, has been Emma Lavrinovich. According to the administration, about one million spectators visit the hall each year; the venue was built on the grounds of the former Greek church, Греческая церковь на Греческой площади. This was reflected in Joseph Brodsky poem, «Остановка в пустыне»; the construction took place between 1967, by a group headed by Aleksandr Zhuk. The project involved architects Valentin Kamensky and Jean Verzhbitsky, the engineers Galkin and Maksimov; the building silhouette is geometrical, the facade is decorated with a huge stained-glass window. Over the front entrance, there is a bronze frieze by sculptor Mikhail Anikushin. By the steps into the building stands the sculpture, «Октябрь», by sculptor Alexander Matveev.

In 2007, the concert hall underwent necessary repairs. The works covered all systems of the building, taking place from July until October 2009. 1.^ "Grand", "Large", "Big" and "Great" are all accepted translations of «Большой». However, "big" is most used within the media in reference to the concert hall. Media related to Oktyabrskiy Big Concert Hall at Wikimedia Commons

For the current active air force, see Eleventh Air Force Alaskan Air Command is an inactive United States Air Force Major Command established in 1942 under the United States Army Air Forces. Its mission was to organize and administer the air defense system of Alaska, exercise direct control of all active measures, coordinate all passive means of air defense. In addition, the command supported Strategic Air Command elements operating through and around Alaska, it was redesignated Eleventh Air Force on 9 August 1990 and, status changed from a major command of the United States Air Force to a subordinate organization of Pacific Air Forces. Established on 18 December 1945 the end of World War II, assuming jurisdiction of former Eleventh Air Force, assets in the Alaska Territory. Headquartered at Davis Army Airfield on Adak, the initial mission of AAC was the consolidation of wartime Army Air Forces in Alaska and training of those forces remaining after demobilization, its headquarters was moved back to Anchorage, was re-established at Elmendorf Field on 1 October 1946.

As well as the reorganization of the command and control echelon in Alaska, the 343d Fighter Group at Shemya AAF was inactivated, replaced by the 57th Fighter Group in keeping with the Air Forces policy of retaining low-numbered units on active duty following the war. The 57th FG was equipped with 3 squadrons of very-long range P-51H Mustangs designed for escort missions of B-29 Superfortresses during the war from the Mariana Islands to Japan and back. Two of its squadrons the 64th and 66th were located at Shemya; the 449th Fighter Squadron was activated at Davis AFB on 1 September 1947. It was equipped with P-61 Black Widows and assigned directly to Headquarters, AAC; the only other flying unit was the 54th Troop Carrier Squadron at Elmendorf Field. Despite the wartime military campaign carried out in the Aleutian Islands, the archipelago was viewed as having little military value, other than refueling transport aircraft on the Great Circle Route from Japan, it was believed. Shortly after the Japanese Capitulation, most airfields in the Aleutians were placed in a standby status.

Headquarters, Alaskan Air Command was moved to Elmendorf Field on 1 October 1946. The Aleutian Sector was inactivated on 1 July 1947. Following the National Security Act of 1947, the United States Air Force assumed control of the original Army Fort Richardson and Elmendorf Field, gaining full ownership of its facilities in 1951; the Alaskan Command, established 1 January 1947, headquartered at Elmendorf, was a unified command under the Joint Chiefs of Staff, based on lessons learned during the war when a lack of coordinated effort hampered operations to drive the Japanese from the western Aleutian Islands of Attu and Kiska. Elmendorf became an Air Force base 28 March. With tight Air Force budgets in the late 1940s, Amchatka AFB was placed in caretaker status in February 1949 and the 449th Fighter Squadron was moved from Davis AFB to Ladd AFB. Cape and Thornborough AFB were inactivated in January 1950. With the exception of Shemya AFB, the Air Force had no active bases in the Aleutian Islands.

Following the Armistice in Korea, Shimeya was declared surplus and inactivated on 1 July 1954. See also: Kee Bird, Boeing RC-135 Strategic Air Command established a significant presence in Alaska in the late 1940s as a result of its strategic reconnaissance mission; the first efforts were in photo-reconnaissance and mapping, with long-range B-29 Superfortress reconnaissance aircraft based at Ladd AFB. With growing tensions in US-Soviet relations, SAC explored the possibility of attacking Soviet targets via great circle routes over the North Pole as part of "Project Nanook". Ladd AFB, due to the geography of its location, was unsuitable for SAC's postwar B-36 Peacemaker bomber as well as the new jet B-47 Stratojet. Ladd, being sited next to the Chena River, could not have its runway expanded to meet the requirements for these new aircraft. SAC chose to expand Ladd's former World War II Air Transport Command satellite field, known as "Mile 26" due to its distance from Fairbanks; the airfield's jurisdiction had been transferred from ATC to Eleventh Air Force on 1 November 1945, but had remained a satellite of Ladd Field, was in a standby status.

Mile 26 known as Eielson AFB had its runway lengthened to 14,500 feet and a major construction project was undertaken to expand and build new support facilities at the base in the late 1940s. The new runway at Eielson was the longest runway in North America at the time, its planned usage was to support SAC deployments of its intercontinental bombers closer to the Soviet Union for possible attacks over the Arctic. The first use of Eielson was by the SAC 97th Bombardment Group, deployed from Smoky Hill AFB, Kansas in November 1947; the group departed in March 1948, with the 5010th Air Base Wing being activated by AAC as a permanent host unit for Eielson, supporting deployed SAC units from the CONUS. Other SAC units followed and Eielson hosted B-29, B-36, B-47 and B-50 wings, which were placed on alert there and ready to strike on a moment's notice; these deployments lasted until 1963. Eielson hosted deployed KC-97s, KC-135s tanker aircraft. SAC activated its provisional 4157th Combat Support Group at Eielson in July 1956 to support additional B-47 Wing deployments to Alaska in addition to 4158th Strategic Wing to support RC-135 electronic intelligence operations from Elmendorf on 1 July 1960.

The 4158th SW provided host station support functions for SAC wing and support ele