A reciprocating engine often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types; the main types are: the internal combustion engine, used extensively in motor vehicles. Internal combustion engines are further classified in two ways: either a spark-ignition engine, where the spark plug initiates the combustion. There may be one or more pistons; each piston is inside a cylinder, into which a gas is introduced, either under pressure, or heated inside the cylinder either by ignition of a fuel air mixture or by contact with a hot heat exchanger in the cylinder. The hot gases expand; this position is known as the Bottom Dead Center, or where the piston forms the largest volume in the cylinder. The piston is returned to the cylinder top by a flywheel, the power from other pistons connected to the same shaft or by the same process acting on the other side of the piston.
This is. In most types the expanded or "exhausted" gases are removed from the cylinder by this stroke; the exception is the Stirling engine, which heats and cools the same sealed quantity of gas. The stroke is the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting. In most types, the linear movement of the piston is converted to a rotating movement via a connecting rod and a crankshaft or by a swashplate or other suitable mechanism. A flywheel is used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle; the more cylinders a reciprocating engine has the more vibration-free it can operate. The power of a reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between the sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine.
This seal is provided by one or more piston rings. These are rings made of a hard metal, are sprung into a circular groove in the piston head; the rings fit in the groove and press against the cylinder wall to form a seal, more when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders measured in cubic centimetres or litres or. For example, for internal combustion engines and two-cylinder designs are common in smaller vehicles such as motorcycles, while automobiles have between four and eight, locomotives, ships may have a dozen cylinders or more. Cylinder capacities may range from 10 cm³ or less in model engines up to thousands of liters in ships' engines; the compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, the volume when the piston is at the top of its stroke.
The bore/stroke ratio is the ratio of the diameter of the piston, or "bore", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square", if it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line, in a V configuration, horizontally opposite each other, or radially around the crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic; some designs have set the cylinders in motion around the shaft, such as the Rotary engine. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle; these are worked by eccentrics or cranks driven by the shaft of the engine. Early designs used the D slide valve but this has been superseded by Piston valve or Poppet valve designs.
In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder. Internal combustion engines operate through a sequence of strokes that admit and remove gases to and from the cylinder; these operations are repeated cyclically and an engine is said to be 2-stroke, 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam; this is fed through one or more larger bore cylinders successively, to extract power from the steam at lower pressures. These engines are called Compound engines. Aside from loo
Michael Mahoney, better known as Wreck Donovan or The Wreck, was a nineteenth-century American sneak thief, river pirate and underworld figure in New York City. He was a well-known criminal for hire on the New York waterfront during the post-American Civil War era and became a member of Patsy Conroy Gang. Mahoney participated in a number of violent robberies during the early-1870s, including his time leading a group of Fourth Ward railroad thieves, although he escaped punishment due to his political connections to Tammany Hall; these activities, would lead to his eventual imprisonment by New York District Attorneys Benjamin K. Phelps and Horace Russell in 1873. Michael Mahoney was born in the old Fourth Ward in Manhattan, he began his criminal career while still a young child and became a skilled thief within a few years. He visited the underworld den known as "Slaughter-house Point", so named because of the alleged murders which occurred within the establishment, located at the corner of James Slip and Water Street.
It was there that he learned his trade from such notorious criminal figures such as Johnny Dobbs, Jack Lowry, John McClosky, Soldier Brown and others. By early adulthood, Mahoney had risen from a low-level "dock rat" to a criminal whose name had "become known to every detective in the country", his portrait was added to the "Rogue's Gallery" at Central Office of the New York Police Department. In the years following the American Civil War, Mahoney established himself as a much feared criminal figure on the New York waterfront and recruited by Patsy Conroy to join his gang of river pirates. During this period, Mahoney worked with Thomas Cummings, Denis Brady, Joe Dollard, Martin Broderick, Sam Lake, John "Johnny the Greek" Keefe and Abe Coakley among others, he and Broderick staged the successful escape of Coakley from the state penitentiary in 1869. From the city-side of the East River, the two men signaled a guard-boat carrying Coakley by waving handkerchiefs; the keeper, stopped to pick him up.
When the boat docked, however and Broderick drew their revolvers and held the guard at gunpoint while Coakley jumped ashore and escaped. Shortly afterwards and Broderick were involved in the robbery of a messenger boy of Stevens Bank in Hoboken, New Jersey; the bank messenger was robbed by the two men while travelling to the Stevens floating battery. After knocking him "senseless" with a sandbag, they jumped into a boat in waiting and rowed back to New York, their escape was short-lived as they were apprehended by Hoboken Police Chief Charles A. Donovan. A subsequent investigation found that Mahoney and Broderick had rented rooms across from the bank and watched the messenger for weeks waiting for the perfect opportunity to make their move. Due to the messengers injuries, he was unable to identify his assailants and Mahoney and Donovan were discharged. A year he was convicted with Denis Brady and Thomas Cummings for nearly beating to death local merchant Albert Bornowsky. Mahoney's political influence with Tammany Hall resulted in a mere six-month prison sentence.
By early 1873, Mahoney was the leader of a gang of railroad thieves in the Fourth Ward. On April 5, Mahoney assaulted Peter R. Corson while boarding a Third Avenue street car with his small son. Mahoney, with two other gang members, blocked the front platform and grabbed him by the neck and stole a pocketbook which had $45; the gang leader was arrested and brought before the Court of General Sessions that month. Assistant District Attorney Horace Russell prosecuted the case and said, in his opening statement, that Mahoney was "one of a class of villains who should be taught that the railroads of the City were intended for the conveyance of honest citizens, not for the operations of gangs of thieves". Russell and his team vowed to "spare no pains" in bringing these men to justice. Mahoney was found guilty by Recorder John K. Hackett and sentenced to 20 years imprisonment at the New York State Prison. Prior to his conviction, John Keefe and Abe Coakley used "every underhanded effort" to save Donovan from incarceration but were prevented in their efforts by District Attorney Benjamin K. Phelps.
The Committee on Budgetary Control is a committee of the European Parliament. With 30 permanent members, it can be seen as the European Union's internal "political watchdog", seeking to identify undesirable developments within EU institutions and other bodies and to elaborate constructive suggestions for improvement. The committee's current chair, elected on 7 July 2014, is Ingeborg Grässle; the Committee on Budgetary Control is responsible for the control of the implementation of the Union's budget, meaning that the taxpayers' money is spent efficiently and according to EU law. In close cooperation with the Court of Auditors, it audits the accounts of EU Institutions and suggests improvements in order to ensure sound financial management, it considers fraud and irregularities in the budget implementation, suggests measures aimed at preventing and prosecuting such cases. In this context, it liaises with the Union's Anti-Fraud Office OLAF to strengthen the fight against fraud and corruption; the discharge procedure is the main tool at hand of the parliamentarians in the committee.
During this procedure it scrutinises the implementation of the EU Budget by all actors involved, i.e. inter alia the Commission, other institutions and Agencies on the basis of the yearly annual report of the European Court of Auditors. For this purpose, the Committee organizes hearings to which it invites members of the examined bodies; the parliamentarians transmit detailed questions about the activities and the performance of the respective proceeding working year. This process starts in October of the following year and is voted in the Committee in March and in the Plenary in April of the next following year; as of 7 July 2014: European Court of Auditors Santer Commission Official Homepage