query: Who played the voice of Violet Parr in The Incredibles?

title: Violet Parr

text: Screenwriter and director Brad Bird conceived Violet as "a teenage girl who just wants to be invisible".[2] In early drafts of the screenplay, Violet is depicted as an infant as opposed to a teenager, since parents Bob and Helen Parr were originally intended to be introduced as retired superheroes who have just begun to attempt to live normal lives much earlier during the film.[3][4] Violet is voiced by American author and actress Sarah Vowell, who related that she was offered the role unexpectedly.[5] While beginning to cast the film's main characters, Bird had been listening to the National Public Radio program This American Life, to which Vowell is a frequent contributor.[2][6][7] During one of Vowell's regular appearances on the show,[2] Bird heard her contribute an anecdote about a cannon she had helped her father, a gunsmith, build.[8][5] Bird wanted to cast Vowell based on her description of the event,[5] deciding that she was "perfect" for the part and immediately calling her to offer her the role.[2] Vowell had already earned a reputation for declining several voice acting jobs prior to The Incredibles, to the point at which her agent warned Bird, "She's a serious writer and she wouldn't do this, so don't waste your time!"[6] However, Vowell states that she simply avoided pursuing animated roles in general because she was content being a writer and found few animated projects particularly interesting prior to The Incredibles.[9]

title: Violet Parr

text: Violet has garnered positive reviews from film critics. The Washington Post's Jennifer Frey described Violet as "instantly familiar as the teenage girl who pines for the cute boy, fights with her little brother and is so uncertain of herself".[72] In addition to praising Pixar's decision to cast the lesser-known Vowell as Violet, Joshua Tyler of CinemaBlend dubbed Violet his "favorite character" in The Incredibles, praising her many "goose-bump worthy moments as she starts to accept who she is."[58] Commending the multidimensionality of the film's characters in general, Hollywood.com's Julia Emmanuele observed that, through Violet, audiences "understand how awkward and insecure being a teenager can be, even without the addition of superpowers."[71] Vulture.com's Abraham Riesman described Vowell's voice acting as "terrific".[130] In addition to praising Vowell's performance, Carla Meyer of the San Francisco Chronicle wrote that the character ultimately "emerges as the most sympathetic member of the family".[60] In a retrospective review, Jonathon Dornbush of IGN cited "Violet’s sense of isolation and misunderstanding" among the main reasons why The Incredibles remains "a deeply relatable, enduring film" and "one of Pixar's best".[131] Slate film critic David Edelstein acknowledged the difficulty of animating Violet's hair while calling her ability to create force fields as "to die for".[7]

title: Violet Parr

text: In Kinect Rush: A Disney Pixar Adventure (2012), players explore six worlds based on various Pixar films, pairing them with Violet in some of the Incredibles-themed levels to navigate around hazards and obstacles.[120][121] Violet is available as an add-on figurine for Disney Infinity (2013), sharing her abilities from the film (her force fields are identified as "plasma shields" in the game). When utilized, the character becomes a player character, and can be used in Toy Box mode, The Incredibles play set and her own adventure Violet's Stealth Mission, in which the player uses Violet to retrieve as many collectibles as possible while remaining undetected by spotlights within a limited timeframe.[122] Violet appears as a player character alongside her family in Lego The Incredibles (2018),[123] whose force fields can be used to intercept laser security systems.[124][125] In early levels, Violet unites with Elastigirl and Dash to rescue Mr. Incredible from Syndrome;[80] the titular family most often works together in order to overcome obstacles, such as Violet levitating over poisonous substances to assist Dash.[126] In 2004, a children's book based on The Incredibles was published entitled The Incredibles: Violet's Incredible Diary, written by children's author Richard Dungworth.[127][128] Described as "Violet's side of the story", the book follows the film albeit written from Violet's perspective in the form of a diary.[129]

title: List of The Incredibles characters

text: John Jackson "Jack-Jack" Parr (voiced by Eli Fucile and Maeve Andrews in the first film, Fucile and Nicholas Bird in the second film) is the Parrs' infant son, the youngest of the Parr children. Initially believed to be the only family member without any powers, he manifests a multitude of superhuman abilities at the end of the first film, most of which are types of shapeshifting. More powers are seen in the short film "Jack-Jack Attack" on the "Incredibles" DVD, making his powers the most versatile of the family, and according to a collectible poster included with some Incredibles toys, still more powers are undisclosed.

title: List of The Incredibles characters

text: Rick returns in "Incredibles 2". He informs the Parr family that his department's Super Relocation program is being shut down, forcing supers across the world to permanently adhere to their secret identities. He then goes on to tell the family that they are on their own now and that he cannot help them any longer, because he is going into forced retirement. After Violet's classmate and crush Tony, who had recently agreed to go out on a date with Violet, witnesses Violet in her super-suit without her mask during the battle with the Underminer, Bob asks him to erase that memory in order to protect Violet's secret identity. However, Dicker erases Tony's "entire" memory of Violet, for which she is heartbroken.

title: List of The Incredibles characters

text: Anthony "Tony" Rydinger (voiced by Michael Bird) is a junior high school teenager, attending the same school as Violet Parr. Violet harbors a secret crush on him. In the end of "The Incredibles", with boosted confidence, Violet manages to attract Tony's attention and he asks her out on a date, which she accepts.

title: List of The Incredibles characters

text: Kari McKeen (voiced by Bret Parker) is a friend of the Parrs, whom Violet calls upon to babysit Jack-Jack while the rest of the family are flying to save Mr. Incredible (in "The Incredibles"). She has taken numerous babysitting classes and feels more than adequately prepared to care for Jack-Jack in any capacity, and assures Helen Parr to that effect. She has one scene in the film, and she is heard later on Mrs. Parr's voice mail, complaining that some "very weird things" are happening; she does apparently learn all of Jack-Jack's powers as she has a defense for all of them after one day. Her eventful night with the baby (see above) is documented in the "Jack-Jack Attack" short included on the DVD release, ending with Rick Dicker erasing her memory of the incident.

title: Violet Parr

text: Violet Parr is a fictional character who appears in Pixar's animated superhero film The Incredibles (2004) and its sequel Incredibles 2 (2018). The eldest child of Bob and Helen Parr (Mr. Incredible and Elastigirl), Violet is born with the superhuman ability to render herself invisible, as well as generate force fields. Voiced by Sarah Vowell, Violet is a shy junior high school student who longs to fit in among her peers, a task she believes is hindered by her superpowers. Throughout the course of the films, Violet gradually matures and becomes more confident in herself as both a young woman and superhero.

title: Violet Parr

text: New computer technology was developed to animate Violet's long black hair, which animators identified as the most difficult component of The Incredibles since such a large quantity of hair had never been featured in a computer-animated film before. The character's hair serves as an important aspect of Violet's character development, which demonstrates her steady increase in self-confidence as she gradually ceases to hide her face behind it.

title: Violet Parr

text: The animators animated a rough test sequence to some of Vowell's dialogue from the radio segment about her father's cannon, in which Violet is depicted being startled by a gun that repeatedly fires in her hands.[5] Despite experiencing some hesitation due having never voiced an animated character before,[2] Vowell accepted the role after receiving an e-mail from the film's producer, agreeing to participate in The Incredibles because she believes that Pixar is consistently "the best at what they do", comparing the offer to "if Nelson Mandela showed up asking for your help to fight racism".[5] Additionally, she had also been a long-time fan of Bird's work as a filmmaker.[9] Vowell ultimately decided to accept the role based on a sole image she had been sent of the character: a drawing of Violet surrounded by her schoolmates, all of whom appear to be happy and outgoing apart from Violet herself, who is instead hunched over and hiding behind her long hair. Vowell concluded, "I can be that kid. I was that kid. I love that archetype of the morose, shy, smart-alecky teenage girl."[5]

title: Incredibles 2

text: Later, Tony, after getting reconnected to Violet, accompanies her to a movie with the family. Outside the theater, the Parrs spot a high-speed pursuit between police and gunmen. Violet leaves Tony at the theater and promises to return in time for the film, before the Parrs give chase in a refurbished Incredibile.

title: Violet Parr

text: Pajiba ranked Violet Pixar's ninth best female character.[141] IndieWire ranked Vowell's work as Violet Pixar's 19th greatest performance, writing that her "quirky tones perfectly captures the kind of girl who wishes she could (and in this case actually can) fade into the background," continuing, "the way she eventually finds her own voice is one of the most moving aspects of the film."[10] Similarly, The Playlist also ranked Vowell's performance 19th.[142] The Cinemaholic ranked The Incredibles the third best film featuring invisible characters, with author Clarisse Tenreiro writing that Violet "possesses perhaps the coolest power of" the film's characters.[143] In 2017, Violet served as inspiration behind the BBC article "Can a 'superpower force field' protect us from hackers?", in which technology writer Matthew Wall likened cybersecurity firm Bromium anti-malware software to the character's abilities several times.[144]

title: Helen Parr (The Incredibles)

text: In "The Incredibles" (2004), Helen is seen as Elastigirl in the time before superheroes are banned. She married Bob Parr (Mr. Incredible) and starts a family: Violet, Dash, and Jack-Jack. She gives up her vigilante job to become a housewife while her husband worked. When Bob starts to act sneakily, Helen suspects an affair and confronts him. Later, when she discovered her husband is in trouble, she pilots a jet to rescue him, accompanied by Violet and Dash.

title: Violet Parr

text: Violet has made several appearances in other media, with Vowell returning to voice the character in various spin-offs and merchandise,[110] including toys and cell phones.[12][11] Violet also appears in several video games inspired by The Incredibles. In the original 2004 video game based on the film, Violet appears mostly in stealth missions,[111] using her invisibility to maneuver past guards and enemies unnoticed.[112] The character's invisibility is limited by her Incredi-Meter,[113] which can become greatly depleted by the use of her powers.[112][114] In later levels, players can combine the powers of Violet and Dash to create the Incredi-Ball, in which Violet surrounds both herself and Dash using a force field, and Dash runs within it to propel it forward.[112] The Incred-Ball has been identified as virtually indestructible.[113] On some platforms, Violet is able to use force fields to levitate other objects.[115] In a negative review, Alex Navarro of GameSpot described Violet's levels as arguably "the worst the game has to offer" due to time limits that restrict her invisibility, making it "difficult to gauge when a guard will or won't notice you."[111] Similarly, Eurogamer's Patrick Garratt wrote that younger children will find playing as Violet increasingly difficult to due to the character's tendency to "run out of Incredible Power juice" quickly, limiting her ability to "sneak her way to the end of the level,"[114] while Duke Ferris of Game Revolution found the character's stealth levels to be "particularly weak".[116] The Incredibles: When Danger Calls (2004) features 10 minigames that revolve around Violet and the rest of her family,[117] particularly using Violet's powers to avoid difficult situations.[118] The characters are first played as their secret identifies before players unlock levels in which they can then be played as their superhuman alter egos.[117] There are two minigames that revolve around Violet and her abilities. In the first, "Violet's Diary Drama", she projects force fields to intercept Dash and prevent him from stealing her belongings, while "Violet Surrounded" features the character using a force field to protect herself from oncoming projectiles and deflect them back at Syndrome's henchmen.[119]

title: Markus Maria Profitlich

text:
Furthermore, Profitlich is the producer of the programme "Weibsbilder", as well as "Deutschland ist schön" (Germany is nice).
The name "Profitlich" is not a stage name, but is probably derived from "a person who acts profitably" (source: Udolph, Jürgen: "Professor Udolphs Buch der Namen", Munich, 2005, P. 78-81). Profitlich also voiced Bob Parr / Mr. Incredible in the German dub of the Pixar films The Incredibles and Incredibles 2.

title: Violet Parr

text: Violet appears in the film's sequel Incredibles 2 (2018),[95] in which she receives more screen time.[96] The film follows Violet as she struggles with being a teenager and a superhero simultaneously,[97] resuming shortly after Violet and Tony have agreed to go on their first date.[98] Tony witnesses Violet and her family battling The Underminer,[99] discovering that Violet is a superhero when she unknowingly removes her mask in his presence, prompting him to run away.[100] Violet protects her family from The Underminer by creating her most powerful force field to-date.[101] Despite limiting the destruction of the villain, superheroes remain illegal, and the Parrs remain prohibited to use their powers, which frustrates Violet.[102] Government agent Rick Dicker erases Tony's memories of the event and inadvertently wipes Tony's memory of Violet altogether,[103] forcing Violet to come to terms with the consequences.[96] Violet's storyline revolves around her struggling with teenage angst,[51] boys, dating and adolescence,[104] while mother Helen, who has been recruited by a pair of entrepreneurs in order to repair superheroes' public image in the hopes of legalizing them again,[52] leaves Violet and her siblings in Bob's charge,[52][105] who becomes challenged with parenting Violet, attempting to make her feel better as she explores her teenage romance.[102][106] Although initially resentful towards Bob for the fact that Dicker erased Tony's memories of her to the point of which she "renounces" her superhero heritage,[107][55] Violet eventually offers assistance upon realizing how much effort her father is putting into raising his children.[108] At the end of the film, Violet simply re-introduces herself to Tony. Just as the characters are about to begin their first date, Violet postpones their date so that she can help her family fight criminals instead, promising to rejoin him afterward.[109]

title: Sarah Vowell

text: In 2004, Vowell provided the voice of Violet Parr, a shy teenager, in the Pixar animated film "The Incredibles", and returned to her role for the film's sequel, "Incredibles 2", in 2018. Additionally, Vowell has also lent her voice to the character for various related video games and "Disney on Ice" presentations in the years following the film's release. The makers of "The Incredibles" discovered Vowell from episode 81 – "Guns" "This American Life", where she and her father fire a homemade cannon. Pixar made a test animation for Violet using audio from that sequence, which was included on the DVD of "The Incredibles". She also wrote and was featured in a documentary included on the same DVD entitled "Vowellett - An Essay by Sarah Vowell", where she reflects on the differences between being superhero Violet and being an author of history books on the subject of assassinated presidents, and what it means to her nephew Owen. Vowell also played Fernanda, Theacher "Aunt" Deborah and Mary Kelly in "The School Future".

title: List of The Incredibles characters

text: Robert Parr (a.k.a. Mr. Incredible) (voiced by Craig T. Nelson in the films, Richard McGonagle in "", and Jeff Bergman in "Lego The Incredibles") possesses superhuman strength, stamina, and durability. He is married to Helen Parr, the superheroine known as Elastigirl, and they have three children together: Violet, Dash, and Jack-Jack.

title: Alessia Amendola

text: In Amendola's film dubbing roles, she voiced Mikaela Banes in the "Transformers" film franchise, Violet Parr in "The Incredibles" and "Incredibles 2" and Gretchen Ross in "Donnie Darko".

title: Violet Parr

text: Vowell's performance and character have proven to be particularly popular among young women and teenager girls, from whom she continues to receive positive feedback.[77] Cosmic Book News crowned Violet "the teen-queen of sarcasm",[23] while Michelle Lima of Oh My Disney wrote that the character boasts "some seriously amazing sarcasm skills."[139] Ana Luisa Suarez of Hollywood.com considers Violet's sarcasm to be among "15 Reasons Why 'The Incredibles' Is The Best Superhero Movie".[140] Rolling Stone ranked Violet the 20th "Best Pixar Movie Character", ahead of Mr. Incredible (24th), with author Alissa Wilkinson calling her "super-smart ... which makes the moment when she finally transforms into a confident superheroine ... that much more delightful."[32] Hypable ranked Violet the third best Incredibles 2 superhero, with author Aaron Locke writing, "It would be great to see Violet take on an investigation of her own."[84]

title: Incredibles 2

text: Craig T. Nelson as Bob Parr / Mr. Incredible, who possesses super strength and limited invulnerability.[4] Holly Hunter as Helen Parr / Elastigirl, who has the ability to stretch her body into many shapes and forms.[5] Sarah Vowell as Violet Parr, the family's daughter and first child, who can become invisible and project force fields for limited lengths of time.[4] Huckleberry Milner as Dashiell "Dash" Parr, the family's troublemaker first son, who has superhuman speed. He was previously voiced by Spencer Fox in the first film.[4] Eli Fucile as Jack-Jack Parr, the infant son of Bob and Helen who has a large assortment of powers. Nick Bird provides the vocal effects of Jack-Jack's monster form. Samuel L. Jackson as Lucius Best / Frozone, Bob's best friend, who has the ability to form ice from humidity.[6] Bob Odenkirk as Winston Deavor, a superhero fan who leads a telecommunications company with his sister Evelyn, and wants to bring back superheroes by revamping the public's perception of them.[7][8][9] Catherine Keener as Evelyn Deavor, Winston's younger sister, the mastermind behind the "Screenslaver", and a technological genius who has never encountered a problem she could not solve.[7][8][9] Bill Wise as a pizza delivery man hypnotized to pose as the "Screenslaver", a villain who hijacks screens and uses them to hypnotize people.[10][11] Brad Bird as Edna "E" Mode, a fashion designer for superheroes and a close friend of the Parrs.[4] Jonathan Banks as Rick Dicker, a government agent responsible for helping the Parrs stay undercover and unremarkable. When his department is shut down, the Parrs are left to their own devices. He was previously voiced by Bud Luckey in the first film; Luckey died in 2018, and the film is dedicated to his memory.[8][9] Michael Bird as Tony Rydinger, Violet's love interest.[11] Sophia Bush as Karen / Voyd, an aspiring superhero with the power to create portals.[8][9] Phil LaMarr as Krushauer and He-Lectrix, aspiring superheroes with the power to telekinetically crush objects and control electricity, respectively.[12] Paul Eiding as Gus Burns / Reflux, an elderly aspiring superhero who can vomit hot lava.[12] Isabella Rossellini as The Ambassador, a foreign official committed to the support and legalization of superheroes.[8][13] John Ratzenberger as The Underminer, a mole-like supervillain who seeks to bring war and destruction to the world.[12] Barry Bostwick as Mayor Jere Burns as Detective No. 1 Adam Rodriguez as Detective No. 2 Kimberly Adair Clark as Honey Best, Frozone's wife.[11] Usher as Lucius Best's valet[14]

title: List of The Incredibles characters

text: The Underminer (voiced by John Ratzenberger) is a mole-like supervillain who appears at the end of "The Incredibles" riding on a gigantic drill-tipped tank, where he announces his "war on peace and happiness", leading into the last shot of the Parr family putting their masks on for battle.

title: Francis Ng

text: He provided the voice for Mr. Incredible/Bob Parr in the Cantonese version of Disney and Pixar's "The Incredibles".

title: Violet Parr

text: Violet debuted in The Incredibles (2004) as the first-born child and only daughter of Bob and Helen Parr,[91] a pair of retired superheroes known to the world as Mr. Incredible and Elastigirl. The character has two younger brothers: Dash and Jack-Jack. A junior high school student with the superhuman abilities to turn invisible and create force fields, Violet is shy and insecure, and would much rather be a "normal" teenager,[77] finding it difficult to fit in among her peers. Helen resumes superhero work in search of Bob, and Violet stows away with Dash onto the jet that their mother is piloting towards Syndrome's private island.[92][93] When the jet is attacked by Syndrome's missiles,[94] Violet fails to create a force field large enough to protect its passengers at her mother's insistence;[72] the plane is downed and the family becomes stranded on Syndrome's island. Helen leaves Violet and Dash hidden in a cave, encouraging Violet to use her powers whenever necessary.[40] Violet and Dash are eventually pursued by Syndrome's henchmen, forcing her to use her powers to defend herself and her brother for the first time; she begins to realize her full potential while striving to master her abilities, which she had been largely suppressing prior.[68] Violet is instrumental in helping her family escape Syndrome's lair, using a force field to interfere with the electromagnetic fields that are imprisoning them,[41] before returning to Metroville where she teams up with her family to defeat Syndrome's robot. Once Jack-Jack is rescued from Syndrome, Violet uses a force field to protect her family from the debris falling from Syndrome's destroyed jet. At Dash's sports meet, Violet finally musters the courage to ask Tony out on a date.[23]

title: The Incredibles (video game)

text: Fifteen years later, superheroes across America have been long-since sued and outlawed for causing too much public destruction and are forced by the US government (chiefly the CIA) to disguise themselves as civilians and live normal lives in hiding. Mr. Incredible has married Elastigirl, who has become Helen Parr, and they have three children together: Violet (who possesses force-field and invisibility powers), Dash (a 190+ mph speedster), and Jack-Jack (who does not appear to have obtained any superhuman abilities).

title: List of The Incredibles characters

text: Violet Parr (voiced by Sarah Vowell) is a 14-year-old junior high school teenager stuck at the crossroads between girl and woman. Violet desperately wants to be like everyone else, to blend in with normal people, and not to stand out. Her superpowers allow her to turn instantly invisible, and to generate spherical force fields to protect herself and also to levitate extremely heavy objects; the interiors of the force fields have an anti-gravitational effect, allowing Violet to levitate inside, but she can be stunned temporarily if the field is struck by a sufficiently large force.

title: Dash Parr

text: The filmmakers cast rising eleven-year-old Spencer Fox who made his feature film debut in "The Incredibles" to voice the diminutive and mischievous son of Bob and Helen Parr. Brad Bird wanted to give Dash a realistic out-of-breath voice in certain scenes such as the jungle scene so he made Fox run four laps around the Pixar studio until he got tired. Due to Fox's voice maturing he was replaced by 10-year-old newcomer Huckleberry Milner in the sequel.

title: Spencer Fox

text: He provided the voice of Dash Parr in "The Incredibles", and again in the Disney on Ice show "Disney Presents Pixar's The Incredibles in a Magic Kingdom Adventure". He also provided the voices of Jim and Tim Possible for the fourth season of "Kim Possible", and he was the voice of Mudbud in the first "Air Buddies" movie.

title: Helen Parr (The Incredibles)

text: Helen Parr (née Truax) is a fictional superhero, created by Brad Bird for the Pixar franchise "The Incredibles". The character is voiced by Holly Hunter in the films and in the "Disney Infinity" video game franchise, while Elizabeth Daily and Ally Johnson voiced her in "The Incredibles" video game and "Lego The Incredibles". Helen has an elasticity-based superpower that allows her body to stretch and contort in a variety of ways. Helen Parr is also known by her superhero name Elastigirl.

title: Violet Parr

text: Vowell stars in a documentary about her work in the film, Vowellet: An Essay by Sarah Vowell,[14] which is included as a bonus feature on The Incredibles' 2004 DVD release.[12] In the "video essay",[15] Vowell discusses the various differences between voicing a superhero and becoming an action figure while she was writing about presidential assassinations,[14][16] contrasting the two distinct careers. The animators also animated Violet to some of Vowell's dialogue from the documentary.[17] Bird, who voices costume designer Edna Mode, was the only other actor Vowell recorded with while working on both films. The director would sometimes temporarily provide the voices of other characters for Vowell to act opposite of, such as Elastigirl in lieu of actress Holly Hunter. For Incredibles 2, Vowell had not been allowed to read to entire script while recording her dialogue, having only been allowed to preview small excerpts in which Violet is speaking or having conversations with other characters. Until watching the film for the first time, Vowell had been under the impression that Incredibles 2 would mostly be about Violet's anger at her father until experiencing the film's other storylines and characters.[8] Despite 14 years separating the releases of the first and second films, Vowell did not find resuming the role to be difficult, identifying Violet as a character to whom she feels "closely tied", having played her for approximately one-third of her life. Syfy Wire's Heather Mason observed that Vowell shares her dry sense of humor with Violet. To-date, the Incredibles films remain Vowell's only animated film roles.[11]


query: Who designed the Vienna State Opera House?

title: Vienna State Opera

text: The opera house was the first major building on the Vienna Ringstrasse commissioned by the Viennese "city expansion fund". Work commenced on the house in 1861 and was completed in 1869, following plans drawn up by architects August Sicard von Sicardsburg and Eduard van der Nüll. It was built in the Neo-Renaissance style by the renowned Czech architect and contractor Josef Hlávka.

title: William Blankenship

text: In Europe, Blankenship sang roles at the opera houses in Vienna (Vienna Volksoper & Vienna State Opera), Stuttgart, Hamburg, Braunschweig (1957–60), Bern (1960), Mannheim, Brunswick, Munich (from 1965), Berne, (1956 European debut), Bregenz (1972 as Phoebus in "The Fairy-Queen" by Henry Purcell). In the United States, he sang with the Santa Fe Opera, San Antonio, San Diego (1968), Dallas Opera, and Houston Grand Opera. He has sung in international festivals in Moscow, Salzburg, Vienna, Munich, and Rio de Janeiro. He performed concerts with major orchestras on radio and television.

title: Electronic libretto

text: Opera houses such as the Valencia Opera House, the National Noh Theatre in Tokyo, the Vienna State Opera in Vienna, the Liceu in Barcelona, the Royal Opera House in London and the Teatro degli Arcimboldi and La Scala (both in Milan) have added the electronic titles, the latter providing English and Italian translations in addition to the original language of the opera.

title: John Pritchard (conductor)

text: Beyond Glyndebourne, Pritchard appeared with the Royal Philharmonic Orchestra, at Edinburgh in 1952 (deputising for Ernest Ansermet, who was ill). He made his début at the Royal Opera House in 1951 and at the Vienna State Opera in 1952. He appeared regularly with the Vienna Symphony (1953–55).

title: Lviv

text:
In 1842 the Skarbek Theatre was opened making it the third largest theatre in Central Europe. In 1903 the Lviv National Opera house, which at that time was called the City-Theatre, was opened emulating the Vienna State Opera house. The house initially offered a changing repertoire such as classical dramas in German and Polish language, opera, operetta, comedy and theatre.
The opera house is named after the Ukrainian opera diva Salomea Krushelnytska who worked here.

title: Waagner-Biro

text: In 1906, the company provided the Vienna State Opera with stage equipment. Forty years later, the company rebuilt the opera house's roof. Other roof projects include Vienna's Stephansdom in 1948, the Munich Olympic facilities in 1969, the Prater Stadium in Vienna in 1985, and the Reichstag dome in Berlin, for which the company won a European Steel Design award in 1999. Waagner-Biro won another award in 2003 for the British Museum's Queen Elizabeth II Great Court.

title: Ingo Metzmacher

text: Ingo Metzmacher is regularly conducting at leading opera houses, including Royal Opera House Covent Garden, Zurich Opera House, La Scala, Teatro Real, Vienna State Opera, Berlin State Opera, Paris Opera and Geneva Opera.

title: Richard Hudson (stage designer)

text: Hudson has designed sets and costumes for the Royal Shakespeare Company, the Royal National Theatre, the Young Vic and The Gate, London. In opera he has worked at the Royal Opera House, English National Opera, La Scala, Milan, Metropolitan Opera, New York City, Opéra National de Paris, Lyric Opera of Chicago, Vienna State Opera, Glyndebourne Festival Opera and in Zürich, Munich, Amsterdam, Venice, Florence, Turin, Bregenz, Houston and Washington, D.C.

title: Pier Luigi Pizzi

text: Pizzi has worked in major houses including La Scala, the Burgtheater in Vienna, the Vienna State Opera, the Paris Opéra, the Royal Opera House at Covent Garden, the Bavarian State Opera in Munich, and the Arena di Verona, as well as the opera houses in Florence, Naples, Palermo, Parma, and the Teatro la Fenice in Venice. He has created numerous productions for the Rossini Opera Festival in Pesaro, where he has had a working relationship for several decades.

title: August Everding

text: His productions were seen in all the major international houses: Vienna State Opera, Salzburg Festival. the Royal Opera House, Covent Garden, London, La Scala, Milan, the Lyric Opera of Chicago, the Metropolitan Opera New York City, San Francisco Opera, Victoria State Opera, and Opera Australia.

title: Vienna State Opera

text: Due to the appalling conditions at Theater an der Wien, the opera company leadership tried to raise significant quantities of money to speed up reconstruction of the original opera house. Many private donations were made, as well as donations of building material from the Soviets, who were very interested in the rebuilding of the opera. The mayor of Vienna had receptacles placed in many sites around Vienna for people to donate coins only. In this way, everyone in Vienna could say they had participated in the reconstruction and feel pride in considering themselves part owners.

title: Stefania Bonfadelli

text: She began studying pianoforte at eight years of age and singing at fourteen in Verona, and later continued these studies in Paris and Vienna. Her operatic debut was with "I puritani" in 1997 at the Vienna State Opera. She also performs in concerts, notably at the Hamburg State Opera, the Bayerische Staatsoper, Oper Frankfurt, the Opéra de Marseille, the Teatro De La Maestranza in Seville, the Concertgebouw and Netherlands Opera in Amsterdam, the Vienna State Opera, the Michigan Opera Theatre in Detroit, the Royal Opera House, Covent Garden, London, the Scala in Milan, the Teatro Regio, Turin, the Teatro di San Carlo in Naples, and the Teatro Verdi in Trieste.

title: Marco Arturo Marelli

text: Marco Arturo Marelli (born 21 August 1949) is a Swiss set designer and stage director who has worked at European opera houses for opera and ballet. He designed sets for ballets by John Neumeier, and for premieres of the operas "Thomas Chatterton" by Matthias Pintscher at the Semperoper in Dresden (1998) and "Medea" by Aribert Reimann at the Vienna State Opera (2010).

title: Franca Squarciapino

text: Franca Squarciapino (born 1940) is an Italian costume designer who won the Academy Award for Best Costume Design in 1990 for "Cyrano de Bergerac". She has spent much of her career designing costumes for major theatres and opera houses, including the Burgtheater in Vienna, Royal Opera at Covent Garden, the Metropolitan Opera, the Vienna State Opera, and Zurich Opera among others.

title: Vienna Mozart Orchestra

text: A number of musicians from famous Viennese orchestras and ensembles collaborate with the Vienna Mozart Orchestra as soloists and conductors, among them members of the Vienna Philharmonic and the Vienna Symphony orchestras. In addition, singers from world-famous opera houses, principally from the Vienna State Opera and the Vienna Volksoper, perform with the Vienna Mozart Orchestra.

title: Michael Levine (set designer)

text: Michael Levine (born 6 November 1961) is a Canadian set designer. He is best known for his work in opera, including the scenic design for the Canadian Opera Company's 2006 production of Wagner's Ring Cycle, directed by Atom Egoyan. Levine has also designed productions for Theatre Passe Muraille, Lyric Opera of Chicago, Vienna State Opera, English National Opera, Teatro alla Scala, Dutch National Opera, Royal Shakespeare Company, the Royal Opera House, and the National Theatre.

title: Jürgen Flimm

text: With the 1978 production of Luigi Nono’s "Al gran sole carico d’amore" in Frankfurt, Flimm for the first time emerged as an opera director. Three years later, the production of Jacques Offenbach's "Les contes d'Hoffmann" followed at the Hamburg State Opera, and in 1990 "Così fan tutte" was performed in Amsterdam. For the latter production, Flimm co-operated for the first time with the Austrian conductor Nikolaus Harnoncourt, who became his most important artistic partner. During the last years, Flimm has produced works by Beethoven, Haydn, Mozart, Schubert, Verdi, Gounod, Stravinsky, Franz Schreker and others at La Scala in Milan, the Metropolitan Opera, the Royal Opera House, Covent Garden, the Lyric Opera of Chicago, the Berlin State Opera, the Zurich Opera, the Vienna State Opera, and the Hamburg State Opera. In summer 2000, he staged a new version of Wagner's "Ring" for the Bayreuth Festival, and in June 2002, he was responsible for the scenic realisation of the world premiere of "Der Riese vom Steinfeld" by Friedrich Cerha at the Vienna State Opera.

title: Traian Grozăvescu

text: Traian Grozăvescu (21 November 1895 – 14 February 1927) was an Austro-Hungarian-born Romanian operatic tenor. Born in Lugoj, he served in the Austro-Hungarian Army in World War I. In 1922, following a disagreement with the Cluj Opera, he left for Vienna and sang at the Vienna State Opera, as well as at the Hungarian State Opera House and the Berlin State Opera, achieving great success.

title: Paul Pyant

text: Pyant's extensive opera credits include lighting designs for the premiere of "The Minotaur" (1990). From 1974 to 1987 he worked with Glyndebourne Opera, where he later designed lighting for Sir Peter Hall's productions of "Le Nozze di Figaro", "Falstaff" and "New Year", as well as Stephen Lawless's production of "Death in Venice", among others. Since 1985, he has designed productions for the English National Opera (ENO). Early designs for ENO included "Lady Macbeth of Mtsensk" in 1987, Handel's "Xerxes" and "Carmen" in 1988, "Lear", "Falstaff" and "Street Scene" the next year. Later, he designed for them "Orfeo ed Euridice" (2001) and others. His designs have also been seen at the Metropolitan Opera in New York, at the Vienna Staatsoper, the Vienna Volksoper, the Royal Opera House in London, La Scala, Milan; Opera de Monte Carlo, the Kirov Opera in St. Petersburg and elsewhere. He has designed ten productions for the Houston Grand Opera, including "Rigoletto" and most recently Handel’s "Xerxes" in 2010.

title: Jacques Urlus

text: During the first decade of the 20th century, Urlus made a series of debuts in different European cities. They included: Berlin (the Berlin State Opera); Prague; Vienna (the Vienna State Opera); Munich (the Bavarian State Opera); Stuttgart; Dresden (the Dresden Opera); Frankfurt; and, lastly, London (the Royal Opera House, Covent Garden, where he sang in 1910 and 1914).

title: Speranza Scappucci

text: Outside of the USA, Scappucci made her UK debut as an opera conductor with Scottish Opera in October 2013. At the Vienna State Opera, Scappucci was the fourth-ever female conductor, and the first female Italian conductor, to conduct a production at the Vienna State Opera, for her house debut as conductor in November 2016. In February 2017, she was the first female conductor to direct the orchestra in the annual Vienna Opera Ball, as an emergency substitute for an indisposed Semyon Bychkov.

title: Music of Vienna

text: Major music venues in Vienna include the State Opera House, the People's Opera House, the Burgtheater, and the Theater an der Wien, the former three of which are owned by the federal government .

title: Robin Wagner (designer)

text:
Wagner's other theatrical work ranges from off-Broadway and regional theatre productions to ballet and opera, including sets for the Metropolitan Opera, the Vienna State Opera, the Hamburg State Opera, the Royal Swedish Opera, the Royal Opera House at Covent Garden, and the New York City Ballet.
Wagner has won the Drama Desk Award for Outstanding Set Design six times out of eleven nominations and the Tony Award for Best Scenic Design three times out of ten nominations.

title: Milena Canonero

text: Canonero has also designed the costumes for several stagings directed by Otto Schenk, such as "Il trittico" (Puccini, Vienna State Opera 1979), "As You Like It" (Shakespeare, Salzburg Festival 1980), "Die Fledermaus" (Strauss, Vienna State Opera 1980), "Andrea Chénier" (Giordano, Vienna State Opera 1981), and "Arabella" (Strauss, Metropolitan Opera 1983). For director Luc Bondy she created the costumes for new productions of Puccini's "Tosca" (Metropolitan Opera, 2009), and of Euripides' "Helena" (Burgtheater, Vienna, 2010).

title: Gladys Kuchta

text: Gladys Kuchta (16 June 1915 - 7 October 1998) was an American operatic soprano who sang leading roles in opera houses worldwide including the Vienna State Opera, Royal Opera House, Bayreuth Festival, San Francisco Opera, and the Teatro Colón.

title: Vienna State Opera

text: The Vienna State Opera (German: Wiener Staatsoper) is an Austrian opera house and opera company based in Vienna, Austria. It was originally called the Vienna Court Opera (Wiener Hofoper). In 1920, with the replacement of the Habsburg Monarchy by the First Austrian Republic, it was renamed the Vienna State Opera. The members of the Vienna Philharmonic are recruited from its orchestra.

title: Michèle Crider

text: In spring 2004, Crider celebrated an important role debut as Imogene in Bellini's "Il pirata" at the Vlaamse Opera. Other highlights of the season were her Carnegie Hall debut in March 2004 in "Un ballo in maschera", her return to the Vienna State Opera House as Aida, and gala concerts in the Stadttheater Bremerhaven and Wiesbaden. In 2004/2005, Crider sang her signature role of Aida at the Staatsoper Berlin, followed by house debuts at La Monnaie in Brussels, the Los Angeles Opera, the Semperoper Dresden, and at the Savonlinna Festival. Further highlights of the season were performances as Tosca at the Vienna State Opera and Amelia in "Un ballo in maschera" and Tosca at the Zurich Opera House.

title: Cristina Gallardo-Domâs

text: Gallardo-Domâs' many Puccini performances include: "Turandot" and "Madama Butterfly" at the Metropolitan Opera, Vienna State Opera, and Royal Opera House; "La bohème" at the Metropolitan Opera, La Scala, and Paris Opéra; "Manon Lescaut" at the Zurich Opera and Los Angeles Opera; "Simon Boccanegra (by Verdi)" at Vienna State Opera, Bavarian State Opera, and the Palau de les Arts Reina Sofia in Valencia; and "Suor Angelica" at Amsterdam's Concertgebouw and Teatro Colón.

title: Saimir Pirgu

text: At the age of 22 he was discovered by Claudio Abbado who chose him to play the role of Ferrando in Mozart's "Così fan tutte". He collaborates with the most prestigious theaters and musical institutions in the world as: Teatro alla Scala in Milan, Opéra National de Paris, Royal Opera House, Metropolitan Opera, Vienna State Opera, Gran Teatre del Liceu, Moscow Bolshoi Theatre, Berlin State Opera and Deutsche Oper, Salzburg Festival, Vienna Musikverein, Bayerische Rundfunks in Munich, and Amsterdam Concertgebouw.

title: Ludwig Hofmann (bass)

text: Ludwig Hofmann (14 January 1895 in Frankfurt am Main – 28 December 1963 in Frankfurt am Main) was a German opera singer (bass), who from the late 1920s obtained worldwide recognition above all as an exponent of Wagnerian roles. He worked principally in the opera houses in Berlin and Vienna and in the Vienna State Opera, and from 1928 to 1942 was frequently involved in the Bayreuth Festivals.

title: Vienna State Opera

text: 2009 marked the 140th anniversary of the Vienna Opera House. To celebrate this milestone an idea designed to reach out and embrace a new audience was conceived. A giant 50 sqm screen was placed on the side of the opera house facing Kärntnerstraße. In four months live broadcasts of over 60 famous operas were transmitted in this way, including performances of Madama Butterfly, The Magic Flute and Don Giovanni. This successful venture brought a new wave of operatic excitement to the many tourists and locals who experienced this cultural event. During daytime the screen displays a replica of the Opera House's façade, as it obstructs a considerable part of the building, along with information about upcoming performances.


query: What is the strength of a hydrogen bond?

title: Hydrogen bond

text: Hydrogen bonds can be intermolecular (occurring between separate molecules) or intramolecular (occurring among parts of the same molecule).[4] Depending on the nature of the donor and acceptor atoms which constitute the bond, their geometry, and environment, the energy of a hydrogen bond can vary between 1 and 40 kcal/mol.[5] This makes them somewhat stronger than a van der Waals interaction, and weaker than fully covalent or ionic bonds. This type of bond can occur in inorganic molecules such as water and in organic molecules like DNA and proteins.

title: Solvation

text: Hydrogen bonding among solvent and solute molecules depends on the ability of each to accept H-bonds, donate H-bonds, or both. Solvents that can donate H-bonds are referred to as protic, while solvents that do not contain a polarized bond to a hydrogen atom and cannot donate a hydrogen bond are called aprotic. H-bond donor ability is classified on a scale (α). Protic solvents can solvate solutes that can accept hydrogen bonds. Similarly, solvents that can accept a hydrogen bond can solvate H-bond-donating solutes. The hydrogen bond acceptor ability of a solvent is classified on a scale (β). Solvents such as water can both donate and accept hydrogen bonds, making them excellent at solvating solutes that can donate or accept (or both) H-bonds.

title: Hydrogen bond

text: A hydrogen atom attached to a relatively electronegative atom is the hydrogen bond donor.[9] C-H bonds only participate in hydrogen bonding when the carbon atom is bound to electronegative substituents, as is the case in chloroform, CHCl3.[10] In a hydrogen bond, the electronegative atom not covalently attached to the hydrogen is named proton acceptor, whereas the one covalently bound to the hydrogen is named the proton donor. In the donor molecule, the H center is protic. The donor is a Lewis base. Hydrogen bonds are represented as H···Y system, where the dots represent the hydrogen bond. Liquids that display hydrogen bonding (such as water) are called associated liquids.

title: Hydrogen bond

text: Theoretically, the bond strength of the hydrogen bonds can be assessed using NCI index, non-covalent interactions index, which allows a visualization of these non-covalent interactions, as its name indicases, using the electron density of the system.

title: Adenosine deaminase

text: The substrate, adenosine, is stabilized and bound to the active site by nine hydrogen bonds. The carboxyl group of Glu217, roughly coplanar with the substrate purine ring, is in position to form a hydrogen bond with N1 of the substrate. The carboxyl group of Asp296, also coplanar with the substrate purine ring, forms hydrogen bond with N7 of the substrate. The NH group of Gly184 is in position to form a hydrogen bond with N3 of the substrate. Asp296 forms bonds both with the Zn ion as well as with 6-OH of the substrate. His238 also hydrogen bonds to substrate 6-OH. The 3'-OH of the substrate ribose forms a hydrogen bond with Asp19, while the 5'-OH forms a hydrogen bond with His17. Two further hydrogen bonds are formed to water molecules, at the opening of the active site, by the 2'-OH and 3'-OH of the substrate.

title: Halogen bond

text: To test the notion of polarizability involvement in the strength of halogen bonding, bromopentafluorbenzene was used as a Lewis base. Consequently, verification of halogen bond complex formation wasn’t obtained. This finding provides more support for the dependence of halogen bonding on atomic polarizability. Utilizing similar donor-acceptor frameworks, the authors demonstrated that halogen bonding strength in the liquid crystalline state is comparable to the hydrogen-bonded mesogens.

title: Polymer

text: The intermolecular forces in polymers can be affected by dipoles in the monomer units. Polymers containing amide or carbonyl groups can form hydrogen bonds between adjacent chains; the partially positively charged hydrogen atoms in N-H groups of one chain are strongly attracted to the partially negatively charged oxygen atoms in C=O groups on another. These strong hydrogen bonds, for example, result in the high tensile strength and melting point of polymers containing urethane or urea linkages. Polyesters have dipole-dipole bonding between the oxygen atoms in C=O groups and the hydrogen atoms in H-C groups. Dipole bonding is not as strong as hydrogen bonding, so a polyester's melting point and strength are lower than Kevlar's (Twaron), but polyesters have greater flexibility.

title: Dimethylol ethylene urea

text:
Wrinkles form in cotton fabrics due to the free hydroxyl groups. Cotton is a form of cellulose chains linked to form firm three-dimensional structures that offer both tensile strength and flexibility due to their carbon-carbon and carbon-oxygen bond based backbone. Since cellulose is composed of glucose units, cyclic carbohydrate molecules, cellulose has free hydroxyl groups (-OH) projecting from each monomeric subunit. These hydroxyl groups tend form hydrogen-bonds to neighboring hydroxyl groups. When the fabric is stressed either by heat or pressure, the original hydrogen bonds in the cotton fabric break and reform with nearby atoms at random. This re-forming of the hydrogen bonds, known as cross linking, is the reason for wrinkles, or creases, in the fabric. DMEU works to prevent these wrinkles by covalently bonding to two free hydroxyl groups in the fabric through a dehydration reaction that is not as easily broken as the hydrogen bond before treatment.
As seen in the figure, this formation of a C-O bond through a dehydration reaction (loss of water) allows the fabric to be bleached and heated to reasonable temperatures without fear of breaking the C-O bonds formed.

title: Hydrogen bond

text: The hydrogen bond can be compared with the closely related dihydrogen bond, which is also an intermolecular bonding interaction involving hydrogen atoms. These structures have been known for some time, and well characterized by crystallography;[38] however, an understanding of their relationship to the conventional hydrogen bond, ionic bond, and covalent bond remains unclear. Generally, the hydrogen bond is characterized by a proton acceptor that is a lone pair of electrons in nonmetallic atoms (most notably in the nitrogen, and chalcogen groups). In some cases, these proton acceptors may be pi-bonds or metal complexes. In the dihydrogen bond, however, a metal hydride serves as a proton acceptor, thus forming a hydrogen-hydrogen interaction. Neutron diffraction has shown that the molecular geometry of these complexes is similar to hydrogen bonds, in that the bond length is very adaptable to the metal complex/hydrogen donor system.[38]

title: List of phenyltropanes

text: In contrast to this trend, it is understood that an increasingly negative Δ"V" is correlated with an increase of strength in hydrogen bonding, which is the opposing trend for the above; this indicates that the 2"β"-substituents (at least for the heterocyclic class) are dominated by electrostatic factors for binding in-the-stead of the presumptive hydrogen bonding model for this substituent of the cocaine-like binding ligand.

title: Symmetric hydrogen bond

text: A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a 3-center 4-electron bond. This type of bond is much stronger than "normal" hydrogen bonds, in fact, its strength is comparable to a covalent bond. It is seen in ice at high pressure (Ice X), and also in the solid phase of many anhydrous acids such as hydrofluoric acid and formic acid at high pressure. It is also seen in the bifluoride ion [F−H−F]. Much has been done to explain the symmetric hydrogen bond quantum-mechanically, as it seems to violate the duet rule for the first shell: The proton is effectively surrounded by four electrons. Because of this problem, some consider it to be an ionic bond.

title: Water

text: The hydrogen bonds are also the reason why the melting and boiling points of water are much higher than those of other analogous compounds like hydrogen sulfide (). They also explain its exceptionally high specific heat capacity (about 4.2 J/g/K), heat of fusion (about 333 J/g), heat of vaporization (), and thermal conductivity (between 0.561 and 0.679 W/m/K). These properties make water more effective at moderating Earth's climate, by storing heat and transporting it between the oceans and the atmosphere. The hydrogen bonds of water are of moderate strength, around 23 kJ/mol (compared to a covalent O-H bond at 492 kJ/mol). Of this, it is estimated that 90% of the hydrogen bond is attributable to electrostatics, while the remaining 10% reflects partial covalent character.

title: Molecular solid

text: A hydrogen bond is a specific dipole where a hydrogen atom has a partial positive charge (δ+) to due a neighboring electronegative atom or functional group. Hydrogen bonds are amongst the strong intermolecular interactions know other than ion-dipole interactions. For intermolecular hydrogen bonds the δ+ hydrogen interacts with a δ- on an adjacent molecule. Examples of molecular solids that hydrogen bond are water, amino acids, and acetic acid. For acetic acid, the hydrogen (δ+) on the alcohol moiety of the carboxylic acid hydrogen bonds with other the carbonyl moiety (δ-) of the carboxylic on the adjacent molecule. This hydrogen bond leads a string of acetic acid molecules hydrogen bonding to minimize free energy. These strings of acetic acid molecules then stack together to build solids.

title: Halogen bond

text: A parallel relationship can easily be drawn between halogen bonding and hydrogen bonding (HB). In both types of bonding, an electron donor/electron acceptor relationship exists. The difference between the two is what species can act as the electron donor/electron acceptor. In hydrogen bonding, a hydrogen atom acts as the electron acceptor and forms a non-covalent interaction by accepting electron density from an electron rich site (electron donor). In halogen bonding, a halogen atom is the electron acceptor. Simultaneously, the normal covalent bond between H or X and D weakens, so the electron density on H or X appears to be reduced. Electron density transfers results in a penetration of the van der Waals volumes.

title: Dispersive adhesion

text: Sometimes grouped into the chemical mechanism of adhesion, hydrogen bonding can increase adhesive strength by the dispersive mechanism. Hydrogen bonding occurs between molecules with a hydrogen atom attached to a small, electronegative atom such as fluorine, oxygen or nitrogen. This bond is naturally polar, with the hydrogen atom gaining a slight positive charge and the other atom becoming slightly negative. Two molecules, or even two functional groups on one large molecule, may then be attracted to each other via Keesom forces.

title: Hypothetical types of biochemistry

text: There is debate about the effectiveness of methane and other hydrocarbons as a solvent for life compared to water or ammonia. Water is a stronger solvent than the hydrocarbons, enabling easier transport of substances in a cell. However, water is also more chemically reactive, and can break down large organic molecules through hydrolysis. A life-form whose solvent was a hydrocarbon would not face the threat of its biomolecules being destroyed in this way. Also, the water molecule's tendency to form strong hydrogen bonds can interfere with internal hydrogen bonding in complex organic molecules. Life with a hydrocarbon solvent could make more use of hydrogen bonds within its biomolecules. Moreover, the strength of hydrogen bonds within biomolecules would be appropriate to a low-temperature biochemistry.

title: Hydrogen bond

text: Hydrogen bonds can vary in strength from weak (1–2 kJ mol−1) to strong (161.5 kJ mol−1 in the ion HF− 2).[11][12] Typical enthalpies in vapor include:

title: Transition metal hydride

text: Although these properties are interrelated, they are not interdependent. A metal hydride can be a thermodynamically a weak acid and a weak H donor; it could also be strong in one category but not the other or strong in both. The H strength of a hydride also known as its hydride donor ability or hydricity corresponds to the hydride's Lewis base strength. Not all hydrides are powerful Lewis bases. The base strength of hydrides vary as much as the pKa of protons. This hydricity can be measured by heterolytic cleaving hydrogen between a metal complex and base with a known pK then measuring the resulting equilibrium. This presupposes that the hydride doesn't heterolytically or homolytically react with itself to reform hydrogen. A complex would homolytically react with itself if the homolytic M-H bond is worth less than half of the homolytic H-H bond. Even if the homolytic bond strength above that threshold the complex is still susceptible to radical reaction pathways.

title: Active site

text: Hydrogen bond: A hydrogen bond is a specific type of dipole-dipole interaction between a partially positive hydrogen atom and a partially negative electron donor that contain a pair of electrons such as oxygen, sulfur and nitrogen. The strength of hydrogen bond depends on the chemical nature and geometric arrangement of each group.

title: Diborane

text: Diborane adopts a D structure containing four terminal and two bridging hydrogen atoms. The model determined by molecular orbital theory indicates that the bonds between boron and the terminal hydrogen atoms are conventional 2-center, 2-electron covalent bonds. The bonding between the boron atoms and the bridging hydrogen atoms is, however, different from that in molecules such as hydrocarbons. Having used two electrons in bonding to the terminal hydrogen atoms, each boron has one valence electron remaining for additional bonding. The bridging hydrogen atoms provide one electron each. Thus the BH ring is held together by four electrons, an example of 3-center 2-electron bonding. This type of bond is sometimes called a 'banana bond'. The lengths of the B-H bonds and the B-H bonds are 1.33 and 1.19 Å respectively, and this difference in the lengths of these bonds reflects the difference in their strengths, the B-H bonds being relatively weaker. The weakness of the B-H vs B-H bonds is indicated by their vibrational signatures in the infrared spectrum, being ~2100 and 2500 cm, respectively. The structure is isoelectronic with CH, which would arise from the diprotonation of the planar molecule ethene. Diborane is one of many compounds with such unusual bonding.

title: Supramolecular assembly

text: Hydrogen bond play an essential role in the assembly of secondary and tertiary structures of large biomolecules. DNA double helix is formed by hydrogen bonding between nucleobases: adenine and thymine forms two hydrogen bonds, while guanine and cytosine forms three hydrogen bonds (Figure "Hydrogen bonds in (a) DNA duplex formation"). Another prominent example of hydrogen bond-assisted assembly in nature is the formation of protein secondary structures. Both the α-helix and β-sheet are formed through hydrogen bonding between the amide hydrogen and the amide carbonyl oxygen (Figure "Hydrogen bonds in (b) protein β-sheet structure").

title: Hydrogen bond

text: Most generally, the hydrogen bond can be viewed as a metric-dependent electrostatic scalar field between two or more intermolecular bonds. This is slightly different from the intramolecular bound states of, for example, covalent or ionic bonds; however, hydrogen bonding is generally still a bound state phenomenon, since the interaction energy has a net negative sum. The initial theory of hydrogen bonding proposed by Linus Pauling suggested that the hydrogen bonds had a partial covalent nature. This interpretation remained controversial until NMR techniques demonstrated information transfer between hydrogen-bonded nuclei, a feat that would only be possible if the hydrogen bond contained some covalent character.[21]

title: Bond valence method

text: Structures containing covalent bonds can be treated using the ionic model providing they satisfy the topological conditions given above, but a special situation applies to hydrocarbons which allows the bond valence model to be reduced to the traditional bond model of organic chemistry. If an atom has a valence, V, that is equal to its coordination number, N, its bonding strength according to Eq. 3 is exactly 1.0 vu (valence units), a condition that greatly simplifies the model. This condition is obeyed by carbon, hydrogen and silicon. Since these atoms all have bonding strengths of 1.0 vu the bonds between them are all predicted to have integral valences with carbon forming four single bonds and hydrogen one. Under these conditions, the bonds are all single bonds (or multiples of single bonds). Compounds can be constructed by linking carbon and hydrogen atoms with bonds that are all exactly equivalent. Under certain conditions, nitrogen can form three bonds and oxygen two, but since nitrogen and oxygen typically also form hydrogen bonds, the resulting N-H and O-H bonds have valences less than 1.0 vu, leading through the application of Eq. 1, to the C-C and C-H bonds having valences that differ from 1.0 vu. Nevertheless, the simple bonding rules of organic chemistry are still good approximations, though the rules of the bond valence model are better.

title: Orbital hybridisation

text: forming a total of three sp orbitals with one remaining p orbital. In ethylene (ethene) the two carbon atoms form a σ bond by overlapping one sp orbital from each carbon atom. The π bond between the carbon atoms perpendicular to the molecular plane is formed by 2p–2p overlap. Each carbon atom forms covalent C–H bonds with two hydrogens by s–sp overlap, all with 120° bond angles. The hydrogen–carbon bonds are all of equal strength and length, in agreement with experimental data.

title: Non-covalent interactions

text: A hydrogen bond (H-bond), is a specific type of interaction that involves dipole-dipole attraction between a partially positive hydrogen atom and a highly electronegative, partially negative oxygen, nitrogen, sulfur, or fluorine atom (not covalently bound to said hydrogen atom). It is not a covalent bond, but instead is classified as a strong non-covalent interaction. It is responsible for why water is a liquid at room temperature and not a gas (given water's low molecular weight). Most commonly, the strength of hydrogen bonds lies between 0 - 4 kcal/mol, but can sometimes be as strong as 40 kcal/mol In solvents such as chloroform or carbontetrachloride one observes e.g. for the interaction between amides additive values of about 5 kJ/mol. According to L. Pauling the strength of a hydrogen bond is essentially determined by the electrostatic charges. Measurements of thousands complexes in chloroform or carbontetrachloride have led to additive free energy increments for all kind of donor-acceptor combinations.

title: Migratory insertion

text: Factors affecting the rate of olefin insertions include the formation of the cyclic, planar, four-center transition state involving incipient formation of a bond between the metal and an olefin carbon. From this transition state, it can be seen that a partial positive charge forms on the β-carbon with a partial negative charge formed on the carbon initially bonded to the metal. This polarization explains the subsequently observed formation of the bond between the negatively charged carbon/hydrogen and the positively charged β-carbon as well as the simultaneous formation of the metal-α-carbon bond. This transition state also highlights the two factors that most strongly contribute to the rate of olefin insertion reactions: (i) orbital overlap of the alkyl group initially attached to the metal and (ii) the strength of the metal-alkyl bond. With greater orbital overlap between the partially positive β-carbon and the partially negative hydrogen/alkyl group carbon, the formation of the new C-C bond is facilitated. With increasing strength of the metal-alkyl bond, the breaking of the bond between the metal and the hydrogen/alkyl carbon bond to form the two new bonds with the α-carbon and β-carbon (respectively) is slower, thus decreasing the rate of the insertion reaction.

title: Carbon–fluorine bond

text: The high electronegativity of fluorine (4.0 for F vs. 2.5 for carbon) gives the carbon–fluorine bond a significant polarity/dipole moment. The electron density is concentrated around the fluorine, leaving the carbon relatively electron poor. This introduces ionic character to the bond through partial charges (C—F). The partial charges on the fluorine and carbon are attractive, contributing to the unusual bond strength of the carbon–fluorine bond. The bond is labeled as "the strongest in organic chemistry," because fluorine forms the strongest single bond to carbon. Carbon–fluorine bonds can have a bond dissociation energy (BDE) of up to 544 kJ/mol. The BDE (strength of the bond) is higher than other carbon–halogen and carbon–hydrogen bonds. For example, the molecule represented by CHX has a BDE of 115 kcal/mol for carbon–fluorine while values of 104.9, 83.7, 72.1, and 57.6 kcal/mol represent carbon–X bonds to hydrogen, chlorine, bromine, and iodine, respectively.

title: Hydrogen-bond catalysis

text: In general, acidity of donor sites correlates well with the strength of the donor. For example, it is a common strategy to add electron-withdrawing aryl substituents on a thiourea catalyst, which can increase its acidity and thus the strength of its hydrogen bonding. However, it is still unclear how donor strength correlates with desired reactivity. Importantly, more acidic catalysts are not necessarily more effective. For instance, ureas are less acidic than thioureas by roughly 6 pKa units, but it is not generally true that ureas are significantly worse are catalyzing reactions.

title: Hydrogen bond

text: A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a three-center four-electron bond. This type of bond is much stronger than a "normal" hydrogen bond. The effective bond order is 0.5, so its strength is comparable to a covalent bond. It is seen in ice at high pressure, and also in the solid phase of many anhydrous acids such as hydrofluoric acid and formic acid at high pressure. It is also seen in the bifluoride ion [F−H−F]−.

title: Hydrogen spillover

text: Hydrogen spillover increases with adsorption temperature and metal dispersion. A correlation has been reported between available surface area and the capacity for hydrogen storage. For PdnP-containing MOFs, in the presence of saturated metal particles, the capacity for hydrogen spillover only relied on the sorbent’s surface area and pore size. On catalysts such as platinum or nickel, atomic hydrogen can be generated at a high frequency. Through surface diffusion, multi-functional transport of hydrogen atoms can enhance a reaction and even regenerate a catalyst. However, problems present in the strength of the hydrogen-support bond; too strong of an interaction would hinder its extraction via reverse spillover and nullify its function as a fuel cell. Conversely, too weak a bond and the hydrogens are easily lost to the environment.

title: Hydrogen bond

text: Because water may form hydrogen bonds with solute proton donors and acceptors, it may competitively inhibit the formation of solute intermolecular or intramolecular hydrogen bonds. Consequently, hydrogen bonds between or within solute molecules dissolved in water are almost always unfavorable relative to hydrogen bonds between water and the donors and acceptors for hydrogen bonds on those solutes.[28] Hydrogen bonds between water molecules have an average lifetime of 10−11 seconds, or 10 picoseconds.[29]


query: Are ceiling fans good for saving energy?

title: Ceiling fan

text: Meanwhile, electric ceiling fans became very popular in other countries, particularly those with hot climates, such as India and the Middle East, where a lack of infrastructure and/or financial resources made energy-hungry and complex freon-based air conditioning equipment impractical. In 1973, Texas entrepreneur H. W. (Hub) Markwardt began importing highly efficient ceiling fans to the United States that were manufactured in India by Crompton Greaves, Ltd. Crompton Greaves had been manufacturing ceiling fans since 1937 through a joint venture formed by Greaves Cotton of India and Crompton Parkinson of England, and had perfected the world's most energy efficient ceiling fans thanks to its patented 20 pole induction motor with a highly efficient heat-dissipating cast aluminum rotor. These Indian manufactured ceiling fans caught on slowly at first, but Markwardt's Encon Industries branded ceiling fans (which stood for ENergy CONservation) eventually found great success during the energy crisis of the late 1970s and early 1980s, since they consumed far less energy (under 70 watts of electricity) than the antiquated shaded pole motors used in most other American made fans. The fans became very effective energy saving appliances for residential and commercial use by supplementing expensive air conditioning with a cooling wind-chill effect. Fans used for comfort create a wind chill by increasing the heat transfer coefficient, but do not lower temperatures directly.

title: HVAC

text: Demand controlled kitchen ventilation (DCKV) is a building controls approach of slowing down kitchen exhaust fans and subsequent supply air in response to the actual cooking loads in a commercial kitchen. Traditional commercial kitchen ventilation systems operate at 100% fan speed independent of the volume of cooking activity and DCKV technology changes that to provide significant fan energy and conditioned air savings. By deploying smart sensing technology, both the exhaust and supply fans can be controlled to capitalize on the Law of Affinity for motor energy savings, reduce makeup air heating and cooling energy, increasing safety and reducing ambient kitchen noise levels.

title: Energy Efficiency Services Limited

text: Under the National Energy Efficient Fan Programme, EESL provides BEE 5 Star rated ceiling fans which are 30% more energy efficient than conventional fans. Fans will be sold for Rs. 1,150 per fan. EESL has distributed 6.2 lakh energy efficient fans under this scheme which will save 2.4 lakh kWh and Rs 8.2 lakh per day to the consumers. The price difference is Rs. 500 which is the primary reason for its low penetration, along with the lack of awareness. With the usage of these energy efficient fans it is estimated that consumer’s electricity bills will reduce by about Rs. 700-730 per year, and recover the extra cost in less than 2 years.

title: INNOVAL

text: The hot climate at Le Port led the team in charge of the INNOVAL project to prepare a cooling strategy for different seasons. During the winter, natural ventilation is sufficient to cool offices and during the mid-season between the winter and the summer, natural ventilation is completed with ceiling fans. However, during the summer, natural ventilation coupled with ceiling fans are not sufficient, consequently, air conditioning has to be used. In buildings in Reunion Island, a significant percentage of the energy consumed is due to air conditioning, therefore, the air conditioning system selected here is an efficient one with a Variable Refrigerant Flow ensuring reliability and energy savings. Moreover, a software tool automatically regulates the power of cooling in relation to office use. Finally, while in Reunion Island, people are used to cooling below 24 °C, the air conditioning of the building cannot cool below 26 °C which is adequate with ceiling fans and natural ventilation. Indeed, with the assistance of ceiling fans, the felt temperature is reduced by 5 °C allowing a final felt temperature of 21 to 22 °C. In order to optimize the refrigerated unit power, the temperature adjustment consists of applying a difference of 5 °C between the outside and the inside. For example, if the outside temperature is 34 °C, the temperature adjustment will be 29 °C. All these choices in operation have led to a decrease from 100 kW to 30 kW in the power required by the refrigerated unit.

title: Ventilation (architecture)

text: With the advent of practical steam power, fans could finally be used for ventilation. Reid installed four steam powered fans in the ceiling of St George's Hospital in Liverpool, so that the pressure produced by the fans would force the incoming air upward and through vents in the ceiling. Reid's pioneering work provides the basis for ventilation systems to this day. He was remembered as "Dr. Reid the ventilator" in the twenty-first century in discussions of energy efficiency, by Lord Wade of Chorlton.

title: ENERPOS

text: Finally, large ceiling fans are installed in every room, even those using air conditioning. Ceiling fans ensure that even in the absence of the necessary breezes, the airflow needed to feel comfortable in the room is provided for the users. This solution significantly reduces the amount of energy consumed. The overall consumption of the ceiling fans and the split system (the latter used to cool the technical rooms) is only 3.7kWh/m².yr compared to a classic air conditioning system in a standard building consuming 80kWh/m².yr.

title: Ceiling fan

text: Commercial or industrial ceiling fans are usually used in offices, factories or industries. Commercial ceiling fans are designed to be more cost effective and more energy efficient than other cooling alternatives. The industrial or commercial ceiling fans usually use three blades and operate with a high-speed motor. Some can be found with more than 3 blades though. These energy efficient ceiling fans usually push massive amounts of air compared to other ceiling fan types. In the 1980s, it was common to find metal-bladed industrial ceiling fans in American households, while industrial fans in household applications are still commonplace today in Middle-Eastern households. A hugger or low profile ceiling fan is usually installed on a low ceiling. They can also be used in rooms with vaulted ceilings when installed on the joist. In cold climates, a ceiling fan may disperse heat to warm up the room as well by dispersing downwards the warm air that rises to the ceiling surface. Though the ceiling fan cannot lower room temperatures, when used in tandem with a room air-conditioner it may be able to disperse the cool air all around the room. Outdoor ceiling fans are ceiling fans designed for outdoor purposes, they are usually water resistant and made of materials that do not get affected by outside temperatures, weather or humidity. Some outdoor ceiling fans are designed to be rained directly on, those are known as "wet" rated ceiling fans. Outdoor ceiling fans that are not designed to be rained directly on are known as "damp" rated. "Mini" ceiling fans are mostly found in less developed places, such as the Philippines and Indonesia, and are made almost entirely out of plastic except for the inside of the motor, etc. These fans, hence the name "mini" ceiling fan are relatively small in size, usually ranging from 16 inches to 36 inches, however some still span to sizes as large as 42 inches in diameter. Additionally, unlike traditional ceiling fans, these fans usually use synchronous motors.

title: Ceiling fan

text: Another concern with installing a ceiling fan relates to the height of the blades relative to the floor. Building codes throughout the United States prohibit residential ceiling fans from being mounted with the blades closer than seven feet from the floor; this sometimes proves, however, to not be high enough. If a ceiling fan is turned on and a person fully extends his or her arms into the air, as sometimes happens during normal tasks such as stretching or changing bedsheets, it is possible for the blades to strike their hands, potentially causing injury. Also, if one is carrying a long and awkward object, one end may inadvertently enter the path of rotation of a ceiling fan's blades, which can cause damage to the fan. Building codes throughout the United States also prohibit industrial ceiling fans from being mounted with the blades closer than 10 feet from the floor for these reasons.

title: Fan (machine)

text: In 1998, Walter K. Boyd invented the HVLS ceiling fan. A lifelong inventor, Boyd was charged with developing a system to cool dairy cattle. Dairy cattle, when overheated, decrease milk production. Using the laws of physics and airflow, Boyd developed a slow moving fan that incorporated 10 aluminum blades and was 8-feet diameter. Unlike traditional ceiling fans that move quickly, this large fan moved slowly. Due to its diameter size, the fan moved a large column of air down and out 360 degrees and continuously mixed fresh air with the stale air inside the barn. They are used in many industrial and agricultural settings, because of their energy efficiency. It also cooled the inside of the barn without causing the dairy cattle undue stress or kicking up dust.

title: Ceiling fan

text: Spinner fans employ a direct-drive motor and do not have a stationary decorative cover (motor housing). This accounts for most industrial-style fans (though such fans sometimes have more moderate-quality motors), and inexpensive residential fans used in most asian countries. Spinner-motor fans, sometimes incorrectly referred to as "spinners", employ a direct-drive (spinner) motor and do have a stationary decorative cover (motor housing). "Spinner-motor" fans account for nearly all fans manufactured from the late 1980s to the present. Skeletal motors, which are a high-quality subset of direct-drive motors, can be found on some higher-quality fans. Examples of skeletal motors include Hunter's "AirMax" motor, Casablanca's "XTR200" motor, and the motors made by Lasko for use in their ceiling fans, and as of 2002 Hunter Original have oil-bath skeletal motor. Skeletal motors differ from regular direct-drive motors in that: They have an open ("skeletal") design, which allows for far better ventilation and therefore a longer lifespan. This is in comparison to a regular direct-drive motor's design, in which the motor's inner workings are completely enclosed within a tight metal shell which may or may not have openings for ventilation; even when openings are present, they are almost always small to the point of being inadequate. They are typically larger than regular direct-drive motors and, as a result, are more powerful and less prone to burning out. Friction-drive ceiling fans. This short-lived type of ceiling fan was attempted by companies such as Emerson and NuTone in the late 1970s with little success. Its advantage was its tremendously low power consumption, but the fans were unreliable and very noisy, in addition to being grievously underpowered. Friction-drive ceiling fans employ a low-torque motor that is mounted transversely in relation to the flywheel. A rubber wheel mounted on the end of the motor's shaft drove a hub (via contact friction, hence the name) which, in turn, drove the flywheel. It was a system based on the fact that a low-torque motor spinning quickly can drive a large, heavy device at a slow speed without great energy consumption (see Gear ratio). Gear-drive ceiling fans. These were similar to (and even less common than) the friction drive models; however, instead of a rubber wheel on the motor shaft using friction to turn the flywheel, a gear on the end of the motor shaft meshed with gear teeth formed into the flywheel, thus rotating it. The company "Panama" made gear driven ceiling fans and sold them through "Family Handyman" magazine in the 1980s. Internal belt-drive ceiling fans. These were also similar in design to gear-drive and friction-drive fans; however, instead of a rubber friction wheel or toothed gear, a small rubber belt linked the motor to the flywheel. The most notable internal belt-drive ceiling fan was a model sold by Toastmaster.

title: Variable air volume

text: Another advantage is energy savings and reduced wear. VAV fan control, especially with modern electronic variable-speed drives, reduces the energy consumed by fans, which can be a substantial part of the total cooling energy requirements of a building. Modulating control of the compressor also reduces wear and delivers further energy savings.

title: Casablanca Fan Company

text: Finally, the DC motor is a Brushless DC Motor that uses less energy than a conventional ceiling fan motor.

title: Building insulation

text: Germany established its requirements of building energy efficiency in 1977, and the first energy code-the Energy Saving Ordinance (EnEV) which based on the building performance was introduced in 2002. And the 2009 version of the Energy Saving Ordinance increased the minimum R-values of the thermal insulation of the building shell and introduced requirements for air-tightness tests. The Energy Saving Ordinance (EnEV) 2013 clarified the requirement of thermal insulation of the ceiling. And it mentioned that if the ceiling was not fulfilled, thermal insulation will be needed in accessible ceilings over upper floor’s heated rooms. [U-Value must be under 0.24 Watts/(m²•K)]

title: Energy conservation measure

text: Energy conservation measures are often combined into larger guaranteed Energy Savings Performance Contracts to maximize energy savings while minimizing disruption to building occupants by coordinating renovations. Some ECMs cost less to implement yet return a higher energy savings. Traditionally, lighting projects were a good example of “low hanging fruit” that could be used to drive implementation of more substantial upgrades to HVAC systems in large facilities. Smaller buildings might combine window replacement with modern insulation using advanced building foams to improve energy performance. Energy dashboard projects are a new kind of ECM which relies on the behavioral change of building occupants to save energy. When implemented as part of a program, case studies (such as that for the DC Schools) report energy savings up 30%. Under the right circumstances, open energy dashboards can even be implemented for free to improve upon these savings even more.

title: Fan coil unit

text: Fan coil units are an excellent delivery mechanism for hydronic chiller boiler systems in large residential and light commercial applications. In these applications the fan coil units are mounted in bathroom ceilings and can be used to provide unlimited comfort zones - with the ability to turn off unused areas of the structure to save energy.

title: Room air distribution

text: Mixing systems generally supply air such that the supply air mixes with the room air so that the mixed air is at the room design temperature and humidity. In cooling mode, the cool supply air, typically around 55 °F (13 °C) (saturated) at design conditions, exits an outlet at high velocity. The high velocity supply air stream causes turbulence causing the room air to mix with the supply air. Because the entire room is near-fully mixed, temperature variations are small while the contaminant concentration is fairly uniform throughout the entire room. Diffusers are normally used as the air outlets to create the high velocity supply air stream. Most often, the air outlets and inlets are placed in the ceiling. Supply diffusers in the ceiling are fed by fan coil units in the ceiling void or by air handling units in a remote plant room. The fan coil or handling unit take in return air from the ceiling void and mix this with fresh air and cool, or heat it, as required to achieve the room design conditions. This arrangement is known as 'conventional room air distribution'.Displacement ventilation systems supply air directly to the occupied zone. The air is supplied at low velocities to cause minimal induction and mixing. This system is used for ventilation and cooling of large high spaces, such as auditoria and atria, where energy may be saved if only the occupied zone is treated rather than trying to control the conditions in the entire space.

title: Ceiling fan

text: For heating, ceiling fans should usually be set to turn the opposite direction (usually clockwise; the blades should spin with the downward turned side leading) and on a low speed (or the lowest speed the fan is able to circulate the air down to the floor). Air naturally stratifies—that is, warmer air rises to the ceiling while cooler air sinks. Unfortunately, this means it is colder on or near the floor where human beings spend most of their time. A ceiling fan, with its direction of rotation set so that air is drawn upward, pulls up the colder air below, forcing the warmer air nearer the ceiling to move down to take its place, without blowing a stream of air directly at the occupants of the room. This action works to even out the temperature in the room, making it cooler nearer the ceiling, but warmer nearer the floor. Thus the thermostat in the area can be set a few degrees lower to save energy, while maintaining the same level of comfort. It is important to run the fan at a low speed (or a lowest speed the fan is able to circulate the air down to the floor) to minimize the wind chill effect described above. However if the ceiling is high enough, or the lowest speed downdraft would not create wind chill effect, it can be left on downdraft year around.

title: Ceiling fan

text: A ceiling fan is a mechanical fan mounted on the ceiling of a room or space, usually electrically powered, suspended from the ceiling of a room, that uses hub-mounted rotating blades to circulate air. Ceiling fans typically rotate more slowly than other types of circulating fans, such as electric desk fans. They cool people effectively by introducing slow movement into the otherwise still, hot air of a room. Fans never actually cool air, unlike air-conditioning equipment, they in fact heat the air due to the waste heat from the motor and friction, but use significantly less power (cooling air is thermodynamically expensive). Conversely, a ceiling fan can also be used to reduce the stratification of warm air in a room by forcing it down to affect both occupants' sensations and thermostat readings, thereby improving climate control energy efficiency.

title: Ceiling fan

text: The Hunter 'Original' (manufactured by the Hunter Fan Co., formerly a division of Robbins & Myers, Inc.) is an example of a cast-iron ceiling fan. It has enjoyed the longest production run of any fan in history, dating from 1906 to the present (it is still being manufactured). The 52" Original employed a shaded-pole motor from its inception until 1984, at which point it was changed to a permanent split-capacitor motor. The 36"/38" Original always employed a shaded pole motor, until it was discontinued somewhere in 1985, in which it was replaced with 42" Original with permanent split-capacitor motor. Though the fan's physical appearance remained unchanged, the motor was further downgraded in 2002 when production was shipped to Taiwan; the motor, though still oil-lubricated, was switched to a "skeletal" design, as discussed below. Then in 2015, when the model was revised, the motor, while still skeletal, got pre-2002 elements back, such as 4" main shaft. Post-2015 Original also has wood blades with PVC overlay for outdoor use, and therefore is damp rated. 20 pole Induction "Pancake" motor ceiling fans. These fans with highly efficient cast aluminum housings, were invented in 1957 by Crompton-Greaves, Ltd of India and were first imported into the United States in 1973 by Encon Industries. This Crompton-Greaves motor was developed through a joint venture with Crompton-Parkinson of England and took 20 years to perfect. It is considered the most energy efficient motor ever manufactured for ceiling fans (apart from the DC motor) since it consumes less energy than a household incandescent light bulb.

title: Fan (machine)

text: Window and central air conditioning in the 1960s caused many companies to discontinue production of fans. But in the mid 1970s, with an increasing awareness of the cost of electricity and the amount of energy used to heat and cool homes, turn-of-the-century styled ceiling fans became immensely popular again as both decorative and energy efficient units.

title: Dedicated outdoor air system

text: Besides the advantages presented above, parallel radiant cooling panels offer other advantages as well, such as compact design, vertical shaft space area savings, and quick accommodation of dynamic controls. Energy savings in DOAS/radiant ceiling cooling panel system can by linked to: cooling coil load reduction, chiller energy reduction, pumping energy consumption and fan energy consumption reduction. In general, due to the total energy recovery and small supply air quantity of DOAS, the chiller energy consumption can be reduced significantly compared to the conventional VAV system. In a study of a pilot DOAS/radiant ceiling cooling panel system, hourly energy simulation predicts that the annual electrical energy consumption of the pilot DOAS/radiant panel cooling system is 42% less than that of the conventional VAV system with economizer control.

title: Fan (machine)

text: After much testing, Boyd discovered HVLS fan technology to be energy efficient as it costs less to run one HVLS fan than it did to run 50 small high-speed fans. Due to the skyrocketing costs of energy, HVLS commercial ceiling fans are used today to supplement HVAC systems in industrial and commercial settings, including warehouses, manufacturing facilities and malls, as HVLS fans help lower heating and cooling costs.

title: Big Ass Fans

text: Big Ass Fans entered the commercial business market in 2008, debuting a line of fans ranging from to in diameter. The following year, it began manufacturing fans in sizes suitable for residential settings. In late 2011, Big Ass Fans acquired a manufacturer of energy efficient residential fans. Haiku models incorporate direct current, permanent magnetics and aerodynamic airfoils making them 80% more efficient than conventional ceiling fans. They held the top 10 spots on Energy Star's Most Efficient 2014 list. In 2014, the company added smart technology SenseME to the Haiku ceiling fan. Haiku with SenseME integrates with the Nest Learning Thermostat through a smartphone app.

title: Energy Efficiency Services Limited

text: Most households in India are cooled by fans, and less than 10% of households have air conditioning. The average rating of the fans installed and sold in the market is between 75-80W, whereas energy efficient fans provide the same level of comfort at about 45-50W. Considering that almost 30 million fans are sold every year, the potential to reduce demand is significant. Replacing the country's 35 crore inefficient ceiling fans in with BEE 5-Star-rated ceiling fans could save 47 billion KWh and reduce load by over 12,250 MW.

title: Ceiling fan

text: Many styles of ceiling fans have been developed over the years in response to several different factors such as growing energy-consumption consciousness and changes in decorating styles. The advent and evolution of electronic technology has also played a major role in ceiling fan development. Following is a list of major ceiling fan styles and their defining characteristics:

title: Ceiling fan

text: Belt-driven ceiling fans. As stated earlier in this article, the first ceiling fans used a water-powered system of belts to turn the blades of fan units (which consisted of nothing more than blades mounted on a flywheel). For period-themed decor, a few companies (notably Fanimation and Woolen Mill) have created reproduction belt-drive fan systems. The reproduction systems feature an electric motor as the driving force, in place of the water-powered motor. DC ceiling fans. These fans use a brushless DC motor that offer much better efficiency than traditional fans driven with AC motors. They usually are quieter than AC motor fans due to the fact they are commutated electronically and use permanent magnet rotors. Among many advantages these fans offer some are higher efficiency, lower noise level, less rotor heat, integration of remote control and other convenience technologies etc. The only drawbacks are the high cost and the presence of complex electronics which may be more likely to fail, making them not ideal for commercial installs containing a large number of fans. However, with the advent of new technologies and better quality control techniques, the latter is becoming less of a concern.[5] Hugger ceiling fans (also known as "flush mount" or "low profile" ceiling fans) have no downrod or canopy like a traditional mount fan, and the motor housing is mounted directly to the mount. Hugger style fans generally have spinner motors, and use a special mounting bracket that holds the motor assembly and the motor housing. They are typically used in rooms with low ceilings. A disadvantage to this design it that since the blades are mounted so close to the ceiling, the air movement is greatly reduced. Bladeless ceiling fans. This type was introduced in 2012 by Exhale fans and uses a bladeless turbine to push air outwards from the fan, which is also the case of regular ceiling fans on updraft mode. These feature a brushless DC motor instead of a normal direct drive motor. High-volume low-speed fans (HVLS fans) are large-diameter ceiling fans intended for large spaces such as warehouses and gymnasiums. These fans generally spin at a low speed and they use airfoil-style blades for optimized air movement. One of the most popular manufactures of HVLS fans is Big Ass Fans. Synchronous motor mini ceiling fans- these are relatively small in size and are made almost completely out of plastic. Punkah style ceiling fans. These fans are based on the earliest form of a fan, that was developed in India which was originally cut from an Indian palmyra leaf. A punkah fan moves slowly in a pendular manner with a rather large blade and is nowadays electrically powered using a belt-driven system. In comparison to a rotating fan it creates a gentle breeze rather than an airflow.

title: Dedicated outdoor air system

text: Many studies have been conducted to demonstrate the energy and cost performance of DOAS in terms of simulations. Khattar and Brandemuehl simulated the parallel system and a conventional single system for a large retail store in Dallas, St. Louis, Washington DC, and New Orleans. The study demonstrated annual energy savings of 14% to 27% and 15% to 23% smaller equipment capacity for the parallel cooling system. Jeong et al. compared the energy and cost performance of a DOAS with parallel ceiling radiant panels to a conventional VAV system with air-side economizer for a nearly office space in an educational building in Pennsylvania. A 42% reduction of the annual energy usage for the DOAS system with substantial savings in both fan and chiller energy use was reported in this study. Emmerich and McDowell evaluated the potential energy savings of DOAS in U.S. commercial buildings. The building model was developed to be consistent with typical new construction and meet the ASHRAE Standard 90.1 (ASHRAE 90.1) requirements. The simulation results indicated that the full DOAS resulted in the annual HVAC energy cost savings ranging from 21% to 38%.

title: Ceiling fan

text: Stack-motor ceiling fans. In the late 1970s, due to rising energy costs prompted by the energy crisis, Emerson invented a new style of electric motor designed specifically for ceiling fans, the "stack" motor. Along with Encon's cast aluminum 20 pole motor, this powerful, energy-efficient motor aided in the comeback of ceiling fans in America, since it was far less expensive to operate than air conditioning. With this design (which consists of a basic stator and rotor), the fan's blades mount to a central hub, known as a flywheel. The flywheel can be made of either metal or reinforced rubber, and can be mounted either flush with the fan's motor housing (concealed) or prominently below the fan's motor housing (known as a "dropped flywheel"). Many manufacturers used and/or developed their own stack motors, including (but not limited to) Casablanca, Emerson, FASCO, Hunter, and NuTone. Some manufacturers trademarked their personal incarnation of this motor: for example, Emerson came out with the "K55" and "K63" motors, Fanimation with the "FDK-2100", and Casablanca with the "XLP-2000". One of the earliest stack-motor fans was the Emerson "Heat-Fan", aka the "Universal Series", a utilitarian fan with a dropped metal flywheel and blades made of either fiberglass or plastic depending on the model. This fan was produced from 1976 through 1983 and, while targeted at commercial settings, also found great success in residential settings. Casablanca Fan Co. also made stack-motor fans with concealed flywheels rather than dropped flywheels. While this motor is not nearly as widely used as in the 1970s and 1980s, it can still be found in certain high-end Emerson, and Fanimation fans. One disadvantage of this type of fan is that the flywheel, if it is made from rubber, will dry out and crack over time and eventually break; this is usually not dangerous, but it renders the fan inoperable until the flywheel is replaced.

title: Thermal destratification

text: Axial destratification fans are self-contained units that are installed in an array at the ceiling with the goal of blowing conditioned air in the ceiling down to the floor, where people live and work. Because axial fans are designed to blow air straight down at the floor, they can be used in ceiling and roof structures over 100 ft. tall. Because axial destratification fans can achieve destratification with low CFMs, it is imperative that the air leaving the nozzle achieve an air speed at the floor of between 0.2 and 0.5 m/s. The result of this level of air movement is the integration of conditioned air from the ceiling with air at the floor level. Failing to impact the floor will result in destratification of medial layers of air but not achieve destratification at the floor. Since the area around the thermostat will not be destratified in this instance, it is hypothesized that there will be little or no cost savings, as the thermostat will continue to overheat or overcool the room.

title: Ceiling fan

text: Due to this renewed commercial success using ceiling fans effectively as an energy conservation application, many American manufacturers also started to produce, or significantly increase production of, ceiling fans. In addition to the imported Encon ceiling fans, the Casablanca Fan Company was founded in 1974. Other American manufacturers of the time included the Hunter Fan Co. (which was then a division of Robbins & Myers, Inc), FASCO (F. A. Smith Co.), and Emerson Electric; which was often branded as Sears-Roebuck.