A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power. Power for the supercharger can be provided mechanically by means of a belt, shaft, or chain connected to the engine's crankshaft. Common usage restricts the term supercharger to mechanically driven units. In 1848 or 1849, G. Jones of Birmingham, England brought out a Roots-style compressor. In 1860, brothers Philander and Francis Marion Roots, founders of Roots Blower Company of Connersville, patented the design for an air mover for use in blast furnaces and other industrial applications; the world's first functional tested engine supercharger was made by Dugald Clerk, who used it for the first two-stroke engine in 1878. Gottlieb Daimler received a German patent for supercharging an internal combustion engine in 1885. Louis Renault patented a centrifugal supercharger in France in 1902.

An early supercharged race car was built by Lee Chadwick of Pottstown, Pennsylvania in 1908 which reached a speed of 100 mph. The world's first series-produced cars with superchargers were Mercedes 6/25/40 hp and Mercedes 10/40/65 hp. Both models had Roots superchargers, they were distinguished as "Kompressor" models, the origin of the Mercedes-Benz badging that continues today. On March 24, 1878 Heinrich Krigar of Germany obtained patent #4121, patenting the first screw-type compressor; that same year on August 16 he obtained patent #7116 after modifying and improving his original designs. His designs show a two-lobe rotor assembly with each rotor having the same shape as the other. Although the design resembled the Roots style compressor, the "screws" were shown with 180 degrees of twist along their length; the technology of the time was not sufficient to produce such a unit, Heinrich made no further progress with the screw compressor. Nearly half a century in 1935, Alf Lysholm, working for Ljungströms Ångturbin AB, patented a design with five female and four male rotors.

He patented the method for machining the compressor rotors. There are two main types of superchargers defined according to the method of gas transfer: positive displacement and dynamic compressors. Positive displacement blowers and compressors deliver an constant level of pressure increase at all engine speeds. Dynamic compressors do not deliver pressure at low speeds. Positive-displacement pumps deliver a nearly fixed volume of air per revolution at all speeds. Major types of positive-displacement pumps include: Roots Lysholm twin-screw Sliding vane Scroll-type supercharger known as the G-Lader Positive-displacement pumps are further divided into internal and external compression types. Roots superchargers, including high helix roots superchargers, produce compression externally. External compression refers to pumps that transfer air at ambient pressure. If an engine equipped with a supercharger that compresses externally is running under boost conditions, the pressure inside the supercharger remains at ambient pressure.

Roots superchargers tend to be mechanically efficient at moving air at low-pressure differentials, whereas at high-pressure ratios, internal compression superchargers tend to be more mechanically efficient. All the other types have some degree of internal compression. Internal compression refers to the compression of air within the supercharger itself, which at or close to boost level, can be delivered smoothly to the engine with little or no backflow. Internal compression devices use a fixed internal compression ratio; when the boost pressure is equal to the compression pressure of the supercharger, the backflow is zero. If the boost pressure exceeds that compression pressure, backflow can still occur as in a roots blower; the internal compression ratio of this type of supercharger can be matched to the expected boost pressure in order to optimize mechanical efficiency. Positive-displacement superchargers are rated by their capacity per revolution. In the case of the Roots blower, the GMC rating pattern is typical.

The GMC types are rated according to how many two-stroke cylinders, the size of those cylinders, it is designed to scavenge. GMC has made 2–71, 3–71, 4–71, the famed 6–71 blowers. For example, a 6–71 blower is designed to scavenge six cylinders of 71 cubic inches each and would be used on a two-stroke diesel of 426 cubic inches, designated a 6–71. However, because 6–71 is the engine's designation, the actual displacement is less than the simple multiplication would suggest. A 6–71 pumps 339 cubic inches per revolution. Aftermarket derivatives continue the trend with 8–71 to current 16–71 blowers used in different motorsports. From this, one can see that a 6–71 is twice the size of a 3–71. GMC made 53 cu in series in 2–, 3–, 4–, 6–, 8–53 sizes, as well as a "V71" series for use on engines using a V configuration. Dynamic compressors rely on accelerating the air to high speed and exchan

2011 Sydney to Hobart Yacht Race

The 2011 Sydney to Hobart Yacht Race, sponsored by Rolex, was the 67th annual running of the "blue water classic" Sydney to Hobart Yacht Race. As in past editions of the race, it was hosted by the Cruising Yacht Club of Australia based in Sydney, New South Wales; as with previous Sydney to Hobart Yacht Races, the 2011 edition began on Sydney Harbour, at 1pm on Boxing Day, before heading south for 630 nautical miles through the Tasman Sea, past Bass Strait, into Storm Bay and up the River Derwent, to cross the finish line in Hobart, Tasmania. Line honours were claimed by Investec Loyal in a time of two days, six hours, 14 minutes and 18 seconds after taking the lead from race favourite and defending champion Wild Oats XI after striking light winds just outside Storm Bay, losing a 20 nautical miles lead; the two boats engaged in a tacking duel up the Derwent River with Investec Loyal stretching its lead to cross the line just three minutes and twelve second ahead of Wild Oats XI. A protest was lodged against Investec Loyal by the race committee after a crew member from Loyal enquired via radio to a helicopter from media network ABC concerning the sails that were set on Wild Oats, but was dismissed by the international jury which ratified Loyal's race position.

News South Wales RP63 yacht Loki was declared the race winner on 30 December with a corrected time of three days 22 minutes 34.32 seconds

Lew Allen Award

Lew Allen Award is a medal of the Jet Propulsion Laboratory. Until 1990 it was called the Director’s Research Achievement Award; this award recognises significant accomplishments or leadership early in an individual's professional career at the Jet Propulsion Laboratory. The list of recent award winners and their citations are: 1998 Michael E. Ressler Eric J. Rignot Simon H. Yueh 1999 James Bock Son van Nghiem Adrian Stoica 2000 Richard Dekany Andrea Donnellan Sabrina M. Grannan 2001 Ayanna Howard Ian Joughin Victoria S. Meadows Juergen Mueller 2002 Serge Dubovitsky Andrew Edie Johnson Dmitry Strekalov 2003 Jennifer Dooley Christophe Dumas Eui—Hyeok Yang 2004 Andrey Matsko Alina Moussessian Charles Norton Michael Seiffert 2005 Daniel Stern Linda del Castillo Lorene Samoska 2006 Amanda Hendrix Harish Manohara Adrian Ponce 2007 Jason Rhodes Paul Johnson 2008 Pekka Kangaslahti Ioannis Mikellides Hui Su Kiri Wagstaff 2009 Charles Matt Bradford Cory Hill Jeffrey Norris Josh Willis 2010 Shannon Brown Julie Castillo-Rogez Amy Mainzer Nathan Strange 2011 Ken Cooper Kevin Hand Richard Hofer Eric Larour 2012 Marina Brozović Ian Clark Baris Erkmen Christian Frankenberg 2013 Abigail Allwood Carmen Boening Michael Mischna David Thompson 2014 Rodney Anderson Michelle Gierach Robert Hodyss 2014 Aaron Parness 2015 Darmindra Arumugam Sabah Bux Damon Landau Jason Williams 2016 Mathieu Choukroun Andrew Klesh Boon Lim David Wiese 2017 Piyush Agram Nacer Chahat Arezou Khoshakhlagh Sylvain Piqueux List of space technology awards List of awards named after people