List of guitar tunings

This list of guitar tunings supplements the article guitar tunings. In particular, this list contains more examples of open and regular tunings, which are discussed in the article on guitar tunings. In addition, this list also notes dropped tunings.
Standard Tuning.
E-A-D-g-b-e
Throughout, this list references standard tuning, i.e. for comparison.
Open.
Major.
Major open-tunings give a major chord with the open strings.
Open B.
Used by Nickelback on "Should've Listened", Devin Townsend in recent years, and Big Wreck on "Albatross".
Open C.
This open C tuning is used by William Ackerman for his "Townsend Shuffle" and by John Fahey for his tribute to Mississippi John Hurt. This tuning is also commonly used by John Butler on his 12-string guitar. This tuning is used on most work by Devin Townsend in his solo work as well as his work with Strapping Young Lad. When playing on a 7-string guitar, he would have a low G as the lowest string to complete the fifth. David Wilcox also recorded his most famous songs, "Eye of the Hurricane" and "Rusty Old American Dream", both from "How Did You Find Me Here", in this tuning, as well as "New World", "Show the Way", "Hold It Up to the Light", and his cover of "It's the Same Old Song" from "Big Horizon", and "Mango" from "East Asheville Hardware".
The English guitar used a repetitive open-C tuning that approximated a major-thirds tuning.
This open-C tuning gives the initial harmonic series when a C-string is struck.
The C-C-G-C-E-G tuning uses the harmonic sequence (overtones) of the note C. When an open-note C-string is struck, its harmonic sequence begins with the notes (C,C,G,C,E,G,B♭,C).
This overtone-series tuning was modified by Mick Ralphs, who used a high C rather than the high G for "Can't Get Enough" on "Bad Company". Ralphs said, "It needs the open C to have that ring," and "it never really sounds right in standard tuning".
Open D.
Open-D tuning is used by Joni Mitchell for her "Big Yellow Taxi", Nick Drake for "Place To Be", Alt-J for "Interlude 2", Boys Like Girls for "Thunder", David Wilcox for "Wildberry Pie", "Mighty Ocean", "Kindness", and "Never Enough", and by Soko for "No More Home, No More Love".
Open-D tuning has been called "Vestapol" tuning.
Richie Havens used Open D tuning to be able to play chords using only his thumb and one or two fingers. Wilco have several songs in Open D.
Kevin Cronin used Open D in "Time for me to fly", the 1978 REO Speedwagon hit song, with four top-string variations for G and A.
This alternative Open D tuning (and its downtuned variations) is frequently used by Mark Tremonti guitarist for the bands Creed, Alter Bridge, and Tremonti. It was also used by Keith Richards on "Jumpin' Jack Flash" and the Stone Roses in "Love Spreads".
Same as Open-D but tuned a half-step down. Used by Alice In Chains on the songs "Over Now", "Nothin' Song", and "Shame in You", and by Guns N' Roses on the song "Jumpin' Jack Flash".
Open F.
C-F-C-F-A-C is the more common of the two.
Used by
F-F-C-F-A-C is also used by Dave Mason on "Only You Know and I Know"
F-A-C-G-C-E is also sometimes used, most notably by Covet`s guitarist Yvette Young.
Open G.
Open G was used in rock by Jimmy Page of Led Zeppelin in the songs "Dancing Days", "That's The Way" and "Black Country Woman", Keith Richards of The Rolling Stones as well as in Mississippi blues by Son House, Charley Patton, and Robert Johnson, some songs by Alter Bridge (including down-tuned and minor variations on "In Loving Memory", "Watch Over You", "Wonderful Life", "Words Darker Than Their Wings", "Cradle to the Grave", and "Dying Light"), and in "Fearless" by Pink Floyd. David Wilcox used this tuning on "The Nightshift Watchman".
Listing the initial six harmonics of the G note, this open-G tuning was used by Joni Mitchell for "Electricity", "For the Roses", and "Hunter (The Good Samaritan)". It was also used by Mick Ralphs for "Hey Hey" on Bad Company's debut album.
and on the Meowtain song "Alleyway" Stone Gossard also used this tuning in the song "Daughter" by Pearl Jam.
Minor: Cross-note.
The following open-tunings use a minor third, and give a "minor chord" with open strings. To avoid the relatively cumbersome designation "open D minor", "open C minor", such tunings are sometimes called "cross-note tunings". The term also expresses the fact that, compared to Major chord open tunings, by fretting the lowered string at the first fret, it is possible to produce a major chord very easily.
Cross-note or open E-minor was used by Bukka White and Skip James.
Cross-note tunings include (low to high):
Modal.
In modal tunings, the strings are tuned to form a chord which is not definitively minor or major. These tunings may facilitate very easy chords and unique sounds when the open strings are used as drones. Often these tunings form a suspended chord on the open strings. A well known user of modal tunings is Sonic Youth.
Extended chord.
In extended chord tunings, the open strings form a seventh, ninth, or eleventh chord.
Regular tunings.
Major seconds.
A compact tuning that fits within one octave and covers the chromatic scale between open strings and the first fret.
Minor thirds.
In the minor-thirds tuning, every interval between successive strings is a minor third. In the minor-thirds tuning beginning with C, the open strings contain the notes (C, D, F) of the diminished C chord.
Major thirds.
"Major-thirds tuning" is a regular tuning in which the musical intervals between successive strings are each major thirds. Unlike all-fourths and all-fifths tuning, major-thirds tuning repeats its octave after three strings, which again simplifies the learning of chords and improvisation.
Neighboring the standard tuning is the major-thirds tuning that has the open strings
A lower major-thirds tuning has the open strings
which "contains two octaves of a C augmented chord".
All fourths.
This tuning is like that of the lowest four strings in standard tuning. Jazz musician Stanley Jordan plays guitar in all-fourths tuning; he has stated that all-fourths tuning "simplifies the fingerboard, making it logical".
Augmented fourths.
Between the all-fifths and all-fourths tunings are "augmented-fourth" tunings, which are also called ""diminished-fifths" or "tritone"" tunings.
All fifths: "Mandoguitar".
All-fifths tuning is a tuning in intervals of perfect fifths like that of a mandolin, cello or violin; other names include "perfect fifths" and "fifths". It has a wide range, thus it requires an appropriate range of string gauges. A high "b"' string has been recently developed by Octave4Plus gauged at .006 which is pretty thin, but under really low tension to prevent breakage.
New standard tuning.
All-fifths tuning has been approximated by the New Standard Tuning (NST) of King Crimson's Robert Fripp. It has a wider range than standard tuning, and its perfect-fifth intervals facilitate quartal and quintal harmony.
Ostrich tuning.
"Ostrich tuning" is a tuning where all strings are tuned to the same note over two or three octaves, creating an intense, chorused drone and interesting fingering potential.
Used by Soundgarden (E-E-e-e-e'-e') on the song "Mind Riot", and by Lou Reed in the Velvet Underground.
Dropped.
"Drop tunings" lower the sixth string, dropping the lowest E string of the standard tuning. Some drop tunings also lower the fifth string (the A-note in standard-tuning). A "drop one" tuning lowers the pitch by one full step.
Some lower tunings may call for a baritone guitar to more easily maintain high string tension and a rich tone. Others can be achieved using a capo and/or a partial capo.
Shifted.
These tunings are derived by systematic increases or decreases to standard tuning.
Lowered (Standard).
Derived from standard EADGBE, all the strings are tuned lower by the same interval, thus providing the same chord positions transposed to a lower key. Lower tunings are popular among rock and heavy metal bands. The reason for tuning down below standard pitch is usually either to accommodate a singer's vocal range or to get a deeper/heavier sound.
Raised.
From standard EADGBE, all the strings are tuned up by the same interval. String tension will be higher. Typically requires thinner gauge strings, particularly the first string which could be as thin as six thousandths of an inch (about the thickness of a single human hair). A capo is typically preferred over these tunings, as they do not increase neck strain, etc. The advantage of these tunings is that they allow an extended upper note range versus a capo used with standard tuning which limits the number of notes that can be played; in some cases, instruo B or E (such as saxophones, which were frequently encountered in early rock and roll music) are more easily played when the accompanying guitar plays chords in the higher tuning. If standard gauge strings are used, the result is often a "brighter" or "tighter" sound; this was a common practice for some bluegrass bands in the 1950s, notably Flatt & Scruggs.
Double-dropped.
Similar to the dropped tunings, except that both the 1st and 6th strings are dropped one full step.
Miscellaneous.
Dad-Gad.
DADGAD was developed by Davey Graham in the early 1960s when he was travelling in Morocco, to more easily play along with Oud music. Among the first to use this tuning were the folk-blues guitarists of the '60s like Bert Jansch, John Renbourn, Martin Carthy, and John Martyn. It was many years later in the 1970s that it became established for accompanists of traditional music, predominantly Scottish and Irish. Due to this popularity it is sometimes referred to as "Celtic" tuning, although this is misleading given its origin and its primary early use in a quite different field of music. Often vocalized as "Dad-Gad", DADGAD it is now common in Celtic music. In rock music, has been used in Led Zeppelin's "Kashmir". Pierre Bensusan is another noted exponent of this tuning. The post-metal group Russian Circles also employ this tuning, and also plays it tuned a half-step down: D-A-d-g-a-d'. Three down-tuned variations are used by the band Sevendust: A Drop C variation, or C-G-c-f-g-c'. (used on the song "Unraveling". Also uses a variation where the lowest string is dropped to G, used on some songs from Kill the Flaw and the song "Life Deceives You"), a Drop B variation, or B'-F-B-e-f-b, and a Drop A# variation, or A'-F-A-d-f-a. Neighboring tunings D-A-d-e-a-e' and C-G-c-d-g-a have been used by Martin Carthy. Also D-A-d-a-a-d', was used by Dave Wakeling on the English Beat's 1983 "Save It For Later".
Dad-Dad.
Nicknamed - "Papa-Papa". DADDAD is common in folk music (Irish, Scottish), and for the execution of a rhythm guitar in "heavy" (alternative music) on 6th on the third string at the same time. To reach the tuning from DADGAD, Open D or Open D Minor, the G string is dropped to D so that the 3rd and 4th strings are tuned to the same pitch. DADDAD tuning is sometimes used on Dobro guitars for rock and blues. Notable users of this tuning include Billy McLaughlin and John Butler.
Cello/Standard guitar.
Essentially a cello tuning with the deeper four strings in fifths and the two highest strings in standard guitar tuning. Used on numerous Pavement songs (including Cut Your Hair and by Foo Fighters on the song "Weenie Beenie"
"Karnivool" tuning.
Hybrid tuning between drop B-tuning and E-standard. Used by the band Karnivool for many of their songs.
Mi-composé.
Mi-composé is a tuning commonly used for rhythm guitar in African popular music forms such as soukous and makossa. It is similar to the standard guitar tuning, except that the d string is raised an entire octave. This is accomplished by replacing the d string with an e' string and tuning it to d'.
"Iris" Tuning.
Tuning used by Johnny Rzeznik of the Goo Goo Dolls on the song "Iris".
E-A-C#-F#-A-C# ("Sleeping Ute").
Tuning used by Grizzly Bear guitarist Daniel Rossen in "Sleeping Ute", the opening song of their album "Shields". Creates an F#m7/E chord when strummed open.
José González tuning.
D-A-D-G-B-E
This is a tuning favored by the Swedish singer-songwriter José González. He uses this on such songs as "Crosses", "Heartbeats" and "Cycling Trivialities" (capo on second fret). It is similar to the standard guitar tuning, but the low E string is dropped to D and the G string is dropped a half step to F/G. Also used by artists such as M. Ward, Stephen Malkmus, and Day Wave.
Dadd9 tuning
D-A-D-F#-A-E. This tuning is used by Tonic in their song Soldier's Daughter with a capo on the 4th fret.
Mr.Tom tuning.
D-F#-A-E-F#-A
This tuning was made by songwriter/composer Mr.Tom (Rawding) during the creation of an original indie folk instrumental "When You Stand By Me" . The tuning is based on the Open D tuning.
Liberty tuning.
E-A-D-g-c'-e' Promoted by Harvey Reid for use in combination with a partial capo, as a system which is easier for children to learn.
Microtonal tuning.
The open strings of a guitar can be tuned to microtonal intervals, however microtonal scales cannot easily be played on a conventional guitar because the frets only allow for a chromatic scale of twelve equally spaced pitches, each a semitone apart. (Certain microtonal scales, particularly quarter tones, can be played on a standard guitar solely by adjusting tunings, but the distance between notes on the scale makes it somewhat impractical.) It is possible to play microtonal scales on a fretless guitar, to convert a fretted guitar into a fretless, or to make a custom neck with a specific microtonal fret spacing.
Guitars can also be refretted to a microtonal scale. On many refretted microtonal guitars, the frets are split, so that the tuning of each string is independent from the others. To enable an adjustable microtonal tuning, there exist guitars with frets that can be moved across the fingerboard.
Extended techniques such as the 3rd bridge technique, slide guitar and prepared guitar techniques can be used to produce microtonality without severe modification to the instrument.
Guitar tunings inspired by other Instruments.
In his on-line guide to alternative tunings for six-string guitars, William Sethares mentions several that are inspired by instruments other than guitars, for example, balalaika (E-A-D-E-E-A), cittern C-G-C-G-C-G, and Dobro G-B-D-G-B-D.
Extended range and other guitar tunings.
Five-string.
Five-string guitars are common in Brazil, where they are known as guitarra baiana and are typically tuned in 5ths. Schecter Guitar Research produced a production model five-string guitar called the Celloblaster in 1998. A five-string tuning may be necessary in a pinch when a string breaks on a standard six-string (usually the high E) and no replacement is immediately available.
Some basic five-string tunings include:
Seven-string.
Similar to five-string bass guitar tuning, seven-string tuning allows for the extra string a fourth lower than the original sixth string. This allows for the note range of B standard tuning without transposing E standard guitar chords down two and a half steps down. Baritone 7-string guitars are available which features a longer scale-length allowing it to be tuned to a lower range.
Lower.
The open C tuning for 7-string guitar was Devin Townsend's preferred tuning for the extreme metal band Strapping Young Lad (GCGCGCE, used on their last two albums. Also used on Ziltoid the Omniscient, "Planet of the Apes" from Deconstruction, and "Failure" from Transcendence).
Dropped.
These tunings have the lowest string (or other strings tuned one full step lower allowing for chord structures similar to six-string drop tunings.
Eight-string.
A continuation of the 7-string, adding another string a perfect fourth lower than the low B of the seven-string guitar. The eight string guitars additional low F string is just a whole step up from a bass guitars low E string.
Nine-string.
A continuation of the eight-string guitar, adding a string lower or higher.
Ten-string.
A continuation of the nine string, adding another lower string to the standard or high A tuning.
Steel guitar.
On pedal steel guitar, the most common tunings on double-neck istruments are the extended-chord C6 tuning and E9 tuning, sometimes known as the "Texas" and "Nashville" tunings respectively. On a double-neck instrument, the neck nearest the player will normally be some form of C6, and the furthest neck E9.
Necks with 12 or more strings can be used with "universal" tunings which combine the features of C6 and E9. On a 12-string pedal steel guitar, all 12 strings are tuned and played individually, not as six double courses as on the 12-string guitar.
On a lap steel guitar there may be up to four necks, each tuned differently. The C6 tuning was a common tuning for a six-string lap steel in the 1920s and 1930s. Tunings with a sixth interval are popular in Western swing and jazz, while tunings containing sevenths are often chosen for blues and rock music.
Renaissance lute.
This tuning may also be used with a capo at the third fret to match the common lute pitch: G-c-f-a-d'-g'. This tuning also matches standard vihuela tuning and is often employed in classical guitar transcriptions of music written for those instruments, such as, for instance, "La Canción Del Emperador" and "Diferencias Sobre Guardame Las Vacas" by Renaissance composer Luis de Narváez.


270 Anahita

Anahita (minor planet designation: 270 Anahita) is a stony S-type Main belt asteroid. It was discovered by C. H. F. Peters on October 8, 1887, in Clinton, New York, and was named after the Avestan divinity Aredvi Sura Anahita.
In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 0.92 AU. The resulting data yielded an effective diameter of .


Infrared gas analyzer

An infrared gas analyzer measures trace gases by determining the absorption of an emitted infrared light source through a certain air sample. Trace gases found in the Earth's atmosphere become excited under specific wavelengths found in the infrared range. The concept behind the technology can be understood as testing how much of the light is absorbed by the air. Different molecules in the air absorb different frequencies of light. Air with much of a certain gas will absorb more of a certain frequency, allowing the sensor to report a high concentration of the corresponding molecule.
Infrared gas analyzers usually have two chambers, one is a reference chamber while the other chamber is a measurement chamber. Infrared light is emitted from some type of source on one end of the chamber, passes through a series of chambers that contains given quantities of the various gases in question.
Principles of Operation.
The design from 1975 (pictured above) is a Nondispersive infrared sensor. It is the first improved analyzer that is able to detect more than one component of a sample gas at one time. Earlier analyzers were held back by the fact that a particular gas also has lower absorption bands in the infra red
The invention of 1975 has as many detectors as the number of gases to be measured. Each detector has two chambers which both have an optically aligned infrared source and detector, and are both filled with one of the gases in the sample of air to be analyzed. Lying in the optical path are two cells with transparent ends. One contains a reference gas and one will contain the gas to be analyzed. Between the infrared source and the cells is a modulator which interrupts the beams of energy.
The output from each detector is combined with the output from any other detector which is measuring a signal opposite to the principal signal of each detector. The amount of signal from other detectors is the amount that will offset the proportion of the total signal that corresponds to the interference. This interference is from gases with a principal lower absorption band that is the same as the principal band of the gas being measured.
For instance, if the analyzer is to measure carbon monoxide and dioxide, the chambers must contain a certain amount of these gases. The infrared light is emitted and passes through the sample gas, a reference gas with a known mixture of the gases in question and then through the "detector" chambers containing the pure forms of the gases in question. When a "detector" chamber absorbs some of the infrared radiation, it heats up and expands. This causes a rise in pressure within the sealed vessel that can be detected either with a pressure transducer or with a similar device. The combination of output voltages from the detector chambers from the sample gas can then be compared to the output voltages from the reference chamber.
The latest Infrared Gas Analyzers.
Like earlier infrared gas analyzers, modern analyzers also use nondispersive infrared technology to detect a certain gas by detecting the absorption of infrared wavelengths that is characteristic of that gas. Infrared energy is emitted from a heated filament. By optically filtering the energy, the radiation spectrum is limited to the absorption band of the gas being measured. A detector measures the energy after the infrared energy has passed through the gas to be measured. This is compared to the energy at reference condition of no absorption.
Many analyzers are wall-mounted devices intended for long-term, unattended gas monitoring. There are now analysers that measure a range of gases and are highly portable to be suitable for a wider range of geoscience applications. Fast response high-precision analyzers are widely used to measure gas emissions and ecosystem fluxes using eddy covariance method when used together with fast-response sonic anemometer.
In some analyzers, the reliability of measurements is enhanced by calibrating the analyzer at the reference condition and a known span concentration. If the air would interfere with measurements, the chamber that houses the energy source is filled with a gas that has no detectable concentration of the gas being measured. Depending on the gas being measured, fresh air, chemically stripped air or nitrogen may be used.


Partes minutae primae


695 Bella

695 Bella is a minor planet orbiting the Sun.
Although this asteroid has dynamic properties that make it a candidate for the Maria family, the spectral properties of the object indicate it is most likely an interloper. Instead, it may have been spalled off from 6 Hebe or its parent body. 695 Bella and 6 Hebe orbit on opposite sides of the 3:1 Kirkwood gap, and the two have similar orbital elements.


Sounds Are Active

Sounds Are Active is an independent record label based in Long Beach, CA. It was founded in 1999 by Chris Schlarb. The label has focused on releasing music in the genres of free jazz, avanthop, ambient and other experimental music.
A strong visual aesthetic has helped to define the label image. Sounds Are Active has worked with such visual artists as Tim McMullen, Jonathan Dueck, Paul Goode, Jason Munn, Grady McFerrin, Laura Park, Jeff Madrid, Aaron Tanner and Joel Speasmaker.
In 2005 Sounds Are Active introduced an option to subscribe to all of their releases (digital and physical) for a year. In November 2006 they released their first film, the rockumentary 40 Bands/80 Minutes!.


782 Montefiore

782 Montefiore is a minor planet orbiting the Sun that was discovered by Austrian astronomer Johann Palisa on 18 March 1914 and named for Clarice Sebag-Montefiore, wife of Alfons von Rothschild of Vienna.
10µ radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 15 km.


Wine gallon

A wine gallon is a unit of capacity that was used routinely in England as far back as the 14th century, and by statute under Queen Anne since 1707. Britain abandoned the wine gallon in 1826 when it adopted imperial units for measurement. The 1707 wine gallon is the basis of the United States' gallon, as well as other measures.
The Imperial gallon was defined with yet another set of temperature and pressure values ( and )
To convert a wine gallon to an Imperial gallon, multiply by 0.833111. To convert an Imperial gallon to a wine gallon, multiply by 1.200320.
Some research concludes that the wine gallon was originally meant to hold 8 troy pounds of wine. The 1707 British statute defines the wine gallon as – e.g. a cylinder in diameter and high, c. 3.785 litre – and was used to measure the volume of wine and other commercial liquids such as cooking oils and honey. A 14th-century barrel of wine contained , which equals one-eighth of the tun of 252 gallons.


Tonne of coal equivalent


2354 Lavrov


Phonometer

A phonometer is an instrument invented by Thomas Edison for testing the force of the human voice in speaking. It consists chiefly of a mouthpiece and diaphragm. Behind the diaphragm is placed a delicate mechanism which operates a 15-inch flywheel by means of which a hole can be bored in an ordinary pine board.


UNIcert

The UNIcert is an international system of certification and accreditation for various languages learnt in a university context. The main goal of UNIcert is to support language education for universities and to provide an accepted certificate that proves language knowledge outside universities.
The system was set up in 1992 by the German "Association of Language Centres, Language Teaching Institutes and Institutes of Foreign Languages" ("Arbeitskreis der Sprachenzentren, Sprachlehrinstitute und Fremdspracheninstitute", AKS). This association acts as a forum for the exchange of information, experience and ideas between institutes and people involved in language work at universities and training institutes, and those taking part in research into language teaching and learning. More than 100 language centres in Germany, Austria and Switzerland are members of the association. The AKS is also one of the founding members of CERCLES, the European Confederation of Language Centres in Higher Education, "a confederation of independent associations from 21 countries of Europe".
Levels.
The levels correspond to levels of the Common European Framework of Reference for Languages
Education.
UNIcert language courses must be taught in small interactive groups. The courses teach written and oral language. A certificate is received subject to satisfactory attendance, and oral and written exam results. For higher UNIcert levels an internship in a foreign country or study in a foreign country is required.
Certificate.
The certificate is issued in the language of the country where the certification is received, in English and in the language studied. It includes a detailed description of the language knowledge and grades of the applicant.
Accreditation.
Institutions offering UNIcert are accredited on a regular basis. This accreditation confirms that the institutions are able to offer a modern language education at university level. Without accreditation they are not allowed to offer UNIcert courses.


Carpet plot

A carpet plot is any of a few different specific types of plot. The more common plot referred to as a carpet plot is one that illustrates the interaction between two or more independent variables and one or more dependent variables in a two-dimensional plot. Besides the ability to incorporate more variables, another feature that distinguishes a carpet plot from an equivalent contour plot or 3D surface plot is that a carpet plot can be used to more accurately interpolate data points. A conventional carpet plot can capture the interaction of up to three independent variables and three dependent variables and still be easily read and interpolated.
Carpet plots have common applications within areas such as material science for showing elastic modulus in laminates, and within aeronautics.
Another plot sometimes referred to as a carpet plot is the temporal raster plot.
Variants.
Three-variable carpet plot (cheater plot).
A carpet plot with two independent variables and one dependent variable is often called a cheater plot for the use of a phantom "cheater" axis instead of the horizontal axis. As a result of this missing axis, the values can be shifted horizontally such that the intersections line up vertically. This allows easy interpolation by having fixed horizontal intervals correspond to fixed intervals in both independent variables. The horizontal shift must sometimes be adjusted in order to eliminate or mitigate overlapping. Depending on the data being depicted, eliminating overlapping is not always possible. The common solution is to split the plot into two carpets.
Four-variable carpet plot (true carpet plot).
Instead of using the horizontal axis to adjust the plot perspective and align carpet intersections vertically, the horizontal axis can be used to show the effects on an additional dependent variable. In this case the perspective is fixed, and any overlapping cannot be adjusted. Because a true carpet plot represents two independent variables and two dependent variables simultaneously, there is no corresponding way to show the information on a conventional contour plot or 3D surface plot.
Carpet plot with isolines.
To add an additional dependent variable, isolines that are a function of the two independent variables can be added within the carpet to create a contour plot in the carpet domain. Contours can be added to cheater plots as well as to true carpet plots.
Lattice plot.
The effects of an additional independent variable can be visualized by multiple carpets on the same plot corresponding to different values of the third independent variable. If the intersections are connected, a lattice appears. For an intermediate value, a whole carpet can be interpolated using the lattice lines. This technique may result in too much overlapping of carpets in a true carpet plot but is always possible for a cheater plot because the separation of the additional carpets can be adjusted on the phantom horizontal axis.


APSET

Andhra Pradesh State Eligibility Test or APSET is an eligibility test for applying for assistant professor position in Universities in Andhra Pradesh, India. The test is conducted based on subjects and only those who have post graduation in that particular field are eligible.
The 2012 eligibility test is conducted by Andhra University when it last conducted in 1999.


Scholarship Examination

The Scholarship Examination (also known as the Grade 5 exam) is a highly competitive Sri Lankan examination conducted by the Department of Examinations of the Ministry of Education. It is optional for students to undertake it during the final year of primary school (Grade 5 (usually ages 9–10)). Based on the results of the exam, students could transfer to prominent national schools. The exams are held in two mediums: Sinhala, and tamil
History.
The examinations were introduced by the late Hon. Dr. C.W.W. Kannangara, who took the initiative in establishing free education when he was the Minister of Education. Under this initiative the government established Madhya Maha Vidyalayas (MMV - Central Colleges) that were scattered around the island. The Scholarship Examination was a means for gifted students from villages to move to better schools with government scholarships.
School rankings.
Girls Schools.
1. Visakha Vidyalaya, Colombo 04 (marks 188)
Controversies.
In recent years the exam has become extremely competitive, therefore many claim that it puts unnecessary pressure on students at an early age. It has been considered as a "parent's" exam rather than student's. It is necessary to carry out a study on the long term success of the scholars.
This exam is now being used as a tool for Political leaders in Sri Lanka to neglect the development of rural schools (source needed).


Marble Machine


The Tides of Manaunaun

The Tides of Manaunaun is a short piano piece in B minor by American composer Henry Cowell (1897–1965). It premiered publicly in 1917, serving as a prelude to a theatrical production, "The Building of Banba". "The Tides of Manaunaun" is the best known of Cowell's many tone cluster pieces.
Background.
"The Building of Banba", for which "The Tides of Manaunaun" was composed, was based on Irish mythological poems by the theosophist John Osborne Varian. "The Building of Banba" has been described by some scholars as a "pageant" or "play", and by Cowell himself (more than fifty years later) as an "opera". The production was staged in the summer of 1917 at a convention of the theosophical community of Halcyon in coastal San Luis Obispo County, California; Varian was a leader of the group, to which he had introduced the 20-year-old Cowell. Cowell would later claim that "The Tides of Manaunaun" had been composed in 1912, or even earlier. In 1944 Cowell arranged this song for orchestra and band – presumably to be played on radio – but the score was lost and no records have been found to confirm the radio broadcast. This song is dedicated to "B.W.W.", Blanche Wetherill Walton (1871–1963), Cowell's foremost patron and adherent over the years as well as a patron to Charles Seeger and Ruth Crawford Seeger. Cowell dedicated five other works to her between 1924 and 1961: "Ensemble, How Come?", "Euphoria", "Merry Christmas for Blanche", and "Birthday Melody for Blanche".
The work is the most famous and widely played of Cowell's tone cluster pieces, which he performed during tours of North America and Europe from the early 1920s through the mid-1930s. A performance of Cowell's so inspired Béla Bartók that the great Hungarian composer sought Cowell's permission to use tone clusters in his own work. Bartók would feature them in his Piano Sonata (1926) and suite "Out of Doors" (1926), his first significant works after three years of little composition.
Other early pieces of Cowell's featuring tone clusters include the atonal, dissonant "Dynamic Motion" (1916) and its five "encores"—"What's This?" (1917), "Amiable Conversation" (1917), "Advertisement" (1917), "Antinomy" (1917, rev. 1959; frequently misspelled "Antimony"), and "Time Table" (1917). In "The Tides of Manaunaun" the clusters resound majestically and then slowly subside, conveying not dissonance but transcendent mystery. As Cowell describes on the final, narrative track of the Folkways album on which his last piano recordings appear,
In Irish mythology, Manaunaun was the god of motion and of the waves of the sea. And according to the mythology, at the time when the universe was being built, Manaunaun swayed all of the materials out of which the universe was being built with fine particles which were distributed everywhere through cosmos. And he kept these moving in rhythmical tides so that they should remain fresh when the time came for their use in the building of the universe.
During the first two decades of his compositional career, Cowell continued often to reference Irish mythology in the titles of his piano pieces. "The Harp of Life" (1924), Cowell said, "is another in the suite based on the early Irish mythological opera," as, he explained, were "The Voice of Lir" (1920) and "The Trumpet of Angus Óg" (1918–24). Additional mythic traditions are referenced by "The Hero Sun" (1922), "The Banshee" (1925), and "The Leprechaun" (1928). Cowell also wrote songs of a similarly mythological character, including "Angus Óg (The Spirit of Youth)" (1917) and "Manaunaun's Birthday" (1924).
Recordings.
"The Tides of Manaunaun" was first recorded around 1925 by Margaret Nikoloric for piano roll. Edwin Hughes played it for President Franklin D. Roosevelt at the White House, and Percy Grainger performed it frequently. (In 1940, Grainger would come to Cowell's aid by hiring him as an assistant when Cowell was paroled after serving four years in prison on a "morals" charge.) Under the name "Deep Tides", Leopold Stokowski orchestrated "The Tides of Manaunaun" as the first of four "Tales of Our Countryside" (also known as "Four Irish Tales"), which he recorded in 1941. Cowell himself would record the original version at least twice—for Pleyel piano roll in the 1920s and for Folkways in the 1960s. It has been most recently recorded by Steffen Schleiermacher (1993, rel. 1994), Sorrel Hays (1997, rel. 1999), and Stefan Litwin (1999).


3365 Recogne


Integrated Train Testing Centre

The Integrated Train Testing Centre (ITTC) is a future railway testing facility in Tuas, Singapore. Constructed at the former site of the Raffles Country Club, the ITTC will allow testing of new rolling stocks and rail systems for the Singapore MRT system. The ITTC will be modelled on other similar railway testing centres in Germany, South Korea and Japan and will incorporate several green features in its design and operations.
First announced on 24 April 2019, construction of the facility began with a groundbreaking ceremony on 17 March 2021. The testing facility is expected to be completed in phases from 2022 to 2024. When fully operational, the ITTC will be the first such facility in Southeast Asia, featuring workshops, an operations control centre, an administration building and three types of tracks for safety tests.
History.
The ITTC was first announced by then transport minister Khaw Boon Wan on 24 April 2019. Hailing it as a "worthwhile investment" expected to cost a few hundred million dollars, Khaw explained that the ITTC will allow "robust" testing of new railway systems without the need to close off MRT lines. In addition, such a facility will allow deeper expertise in railway operations and maintenance.
Contract 190 for the design and construction of the ITTC was awarded to GS Engineering and Construction Corp (GS Engineering) on 17 April 2020 at a contract sum of S$639.5 million (US$ million). On 17 March 2021, construction of the ITTC began with a groundbreaking ceremony. The testing centre is to be constructed in two phases. The first phase, which includes the high-speed track, is targeted to be completed by the end of 2022 to allow testing of the new Circle line Stage 6 trains in 2023. The ITTC is expected to be fully completed by the end of 2024 with the completion of the two other test tracks and other facilities.
Description.
The ITTC will be constructed in Tuas, on the former site of the Raffles Country Club that was originally acquired for the now-cancelled Kuala Lumpur–Singapore high-speed rail. When completed by 2024, the ITTC will allow integrated systems testing for different trains and rail systems simultaneously, avoiding the need to utilise existing operational lines for testing. The testing facility, designed by the Korea Railroad Research Institute, will include an operations control centre, testing equipment and a rolling stock workshop. The ITTC will have of track that will be interoperable across various types of signalling systems and powered by both third-rail and overhead catenary. The tracks will include:
Intended to achieve the Building and Construction Authority’s Green Mark Platinum certification, the ITTC is planned to be energy efficient with the use of LED lights, solar panels and a centralised cooling system. The various facilities within the ITTC will be connected via sheltered linkways and will feature bicycle parking to encourage walking and cycling within the compound.


943 Begonia

943 Begonia is a large, carbonaceous background asteroid, approximately in diameter, from the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 20 October 1920 and given the provisional designations and . The dark C-type asteroid (Ch) has a rotation period of 15.7 hours. It was named after the genus of popular houseplants, "Begonia".
Orbit and classification.
"Begonia" is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the outer asteroid belt at a distance of 2.5–3.8 AU once every 5 years and 6 months (2,010 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.21 and an inclination of 12° with respect to the ecliptic. The body's observation arc begins at Heidelberg Observatory on 21 October 1920, the night after its official discovery observation.
Naming.
This minor planet was named after the genus of tropical herbs, "Begonia". These flowering plants belongs to the Begoniaceae family and are popular houseplants, widely cultivated as ornamentals. The was mentioned in "The Names of the Minor Planets" by Paul Herget in 1955 (). Only a minority of minor planets are named .
Reinmuth's flowers.
Due to his many discoveries, Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between and . This list also contained a , that were all named after plants, in particular flowering plants "(also see list of minor planets named after animals and plants)".
Physical characteristics.
In the SDSS-based taxonomy, "Begonia" is a common carbonaceous C-type asteroid, while in the Tholen classification, it is a stony S-type, somewhat similar to the dark and rare T-type asteroids. Alternatively, in the Small Solar System Objects Spectroscopic Survey (S3OS2), it is classified as an X-type in the survey's Tholen-like taxonomy, and as a hydrated carbonaceous Ch-subtype in the SMASS-like taxonomic variant (Bus–Binzel) of the survey.
Rotation period.
In March 2005, a rotational lightcurve of "Begonia" was obtained from photometric observations by French amateur astronomers Laurent Bernasconi, Raymond Poncy and Silvano Casulli. Lightcurve analysis gave a well-defined rotation period of hours (0.6525 days) with a brightness variation of magnitude (). An identical period of hours with an amplitude of magnitude was measured by their colleague René Roy in May 2011 (). In February 2016, Jean-Paul Godard and Frédéric Bergero also determined a period of hours and an amplitude of magnitude ().
Diameter and albedo.
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), "Begonia" measures , and kilometers in diameter, and its surface has an albedo of , and , respectively. The "Collaborative Asteroid Lightcurve Link" adopts the results from IRAS, that is, an albedo of 0.0456 and a diameter of 69.21 km based on an absolute magnitude of 9.77.
Further published mean-diameters and albedos by he WISE team include , , and with corresponding albedos of , , and . An asteroid occultation on 25 March 2005, gave a best-fit ellipse dimension of 69.0 × 69.0 kilometers. These timed observations are taken when the asteroid passes in front of a distant star. However the quality of the measurement is poorly rated.


4845 Tsubetsu


Venezuelan units of measurement

A number of units of measurement were used in Venezuela to measure quantities like length, mass, etc. Metric system was optional in Venezuela since 1857, and has been compulsory since 1914.
System before metric system.
Older system was Spain (Castilian) System.
Length.
Several units were used. Following of Granada:
1 vara = 0.8 m
1 meile = 6280 vara.
Some other units are:
1 legua = 6280 vara
1 pie = vara
1 cuarta = vara
1 pulgada = vara.
According to an older source, one vara was equal to 0.835 m (32.874 in).
Mass.
Several units were used. Following of Granada:
1 libra = 0.5 kg
1 bag = 62.5 kg.
Some other units are:
1 tonelada = 2000 libra
1 carga = 250 libra
1 Saco = 125 libra
1 Quintal = 100 libra
1 arroba = 25 libra
1 onza = libra.
According to another older source, one quintal was equal to 46.012 kg (101.438 1 lb).
Capacity.
One arroba was equal to 16.137 l.


Transportation Technology Center, Inc.

Transportation Technology Center (TTC), is a railroad equipment testing and training facility located northeast of Pueblo, Colorado.
It originated as the High Speed Ground Test Center (HSGTC) for the Department of Transportation (DOT) in 1971 as a site to test several hovertrain concepts. When those projects were completed in the 1970s, the site was handed to the Federal Railroad Administration (FRA).
The TTC is managed under a "care, custody, and control" contract with Transportation Technology Center, Inc. (TTCI), a subsidiary of the Association of American Railroads (AAR) and serves member railroads.
History.
Two United States Department of Commerce initiatives are credited with the genesis of the HSGTC: the Northeast Corridor Transportation Project (1964) and the High Speed Ground Transportation Act of 1965, which created the Office of High Speed Ground Transportation (OHSGT). OHSGT was absorbed by the FRA, part of the DOT, following that agency's creation in 1967. At the time, OHSGT, whose charter was to research and develop high speed rail transit, was investigating the use of magnetic or air cushion levitation of rail vehicles, but there were no suitable test sites. A proposed test site was investigated at the former Lowry Air Force Base near Denver, Colorado, but abandoned as the terrain was too rough; further site evaluation led the Secretary of Transportation to select the site for HSGTC near Pueblo in December 1969.
The Rail Dynamics Laboratory, the first building at the site, was designed by Wyle Laboratories in 1970 and construction began in July 1972, by Houston Construction/Wilkins Construction.
The (Rail) Transit Test Track (TTT) was dedicated on October 12, 1972, during a ceremony that also included the unveiling of the State-of-the-Art Car (SOAC); the principal speaker was United States Secretary of Transportation John A. Volpe. Initially, just of the TTT were built in Fiscal Year 1971; the remaining were completed in September 1972 and checked on September 8 using locomotive DOTX 001 and two NYCTA R42 subway cars. In addition to SOAC testing, early tests conducted at HSGTC included the evaluation of the US Standard Light Rail Vehicle.
In March 2021, the FRA awarded a contract to ENSCO Inc, who are responsible for operations and maintenance of TTC. In addition, ENSCO will expand the use of TTC to support more general ground transportation research.
Facility.
The Transportation Technology Center occupies a site northeast of Pueblo, Colorado and just north of the US Army's Pueblo Chemical Depot. The site has laboratories and approximately of railroad track used to test locomotives, vehicles, track components, and signaling devices. The tracks are designed to replicate conditions seen on service environments, varying from precisely engineered high-speed tracks to track intentionally designed with irregularities.
In addition to the test tracks, there are several buildings at the site.


Defense Language Proficiency Tests

The Defense Language Proficiency Test (DLPT) is a battery of foreign language tests produced by the Defense Language Institute and used by the United States Department of Defense (DoD). They are intended to assess the general language proficiency of native English speakers in a specific foreign language, in the skills of reading and listening. An Oral Proficiency Interview (OPI) is sometimes administered to Defense Language Institute students to establish the graduate's proficiency in speaking following training there, but it is not part of the DLPT.
Description.
The tests are meant to measure how well a person can function in real-life situations in a foreign language according to well-defined linguistic tasks and assessment criteria. Originally paper tests, they are increasingly delivered by computer.
The tests are used to assess the skill level of DoD linguists. Linguists are tested once a year in the skills of reading and listening. Test scores determine the amount of Foreign Language Proficiency Pay (FLPP) that a military linguist receives, and also whether they are qualified for certain positions that require language aptitude. DLPT scores may also figure into the readiness rating of a military linguist unit.
Scoring for the current (2007) series of tests, called DLPT5, is, like that for their predecessors, based on the guidelines of the Interagency Language Roundtable (ILR), with the test results stated as levels 0+ through 3 or up to 4 for some languages.
Military language analysts are required to maintain a L2/R2 proficiency. Exams are administered annually, normally immediately after language upkeep classes, and can be taken as often as every 6 months without a language refresher course. In order to receive extra pay, they must exceed the minimum score for that language in one or more categories without falling below the minimum in either. For example:
Each service maintains independent FLPP rates, which vary based on the difficulty of the language, the number of speakers of that language in the service, and the needs of the service. FLPP is awarded in addition to base pay, other pay, and is subject to taxation, except within a war zone.
DLI students, regardless of their course grades, may not graduate without achieving an L2/R2 on the DLPT. They must also pass a series of tests called "FLO (Final Learning Objective) Tests", as well as achieve a minimum of 1+ on the OPI. Although there is a minimum standard for DLI graduation, military language analysts are not required to maintain "speaking" proficiency unless required in the performance of duties.
Because of the subjective wording of the distractors (i.e., the "wrong" answers), the fact that many individuals take versions of the test numerous times and acquire a feel for its peculiarities while others lack that advantage, and the fact that it was not nearly challenging enough, the status of the DLPT IV as a proficiency test was controversial. These are among the reasons why the DLPT5 was instated, with an emphasis on incorporating "authentic materials". The intention of the DLPT5 was to provide a more accurate idea of how proficient the test taker was; whether it accurately assesses proficiency is as much (or even more so) a source of controversy as with the previous version. Because the net effect on military linguists was an average drop of about half a point of proficiency across all skills and all languages, many believe that the new version was intended to be a cost saving measure by reducing FLPP.
While the format of previous DLPTs was consistent across languages, there are two distinct formats of the DLPT5—multiple choice (in Russian, Chinese, MSA, and others) and constructed response (in some of the so-called "Less Commonly Taught Languages" like Hindi and Albanian).
DLPT5 was initially slated to be a computer-based test, but during that version's infancy, it was proctored much like the previous exams, using scantron sheets, taped media, and test booklets. DLPT5 was taken in conjunction with DLPT IV during the trial stage of that version, and has since usurped it as the standard test. Although some versions, such as those given to linguists in the field, abroad, or in other extraordinary situations, are still paper tests, the CONUS facilities which house linguists use the computer proctored exams.
DLPT is used to measure both government and military proficiency in the United States, whereas the ACTFL proficiency test is used in academic circles. Below is an equivalency chart:


IRIS (biosensor)

Interferometric reflectance imaging sensor (IRIS), formerly known as the spectral reflectance imaging biosensor (SRIB), is a system that can be used as a biosensing platform capable of high-throughput multiplexing of protein–protein, protein–DNA, and DNA–DNA interactions without the use of any fluorescent labels. The sensing surface is prepared by robotic spotting of biological probes that are immobilized on functionalized Si/SiO2 substrates. IRIS is capable of quantifying biomolecular mass accumulated on the surface.
Measurement.
To perform a measurement, the sample is illuminated with multiple different wavelengths from either a tunable laser or different color LEDs; typically speaking, a relatively narrow bandwidth optical source. The reflection intensity is imaged using a CCD or CMOS camera. By using interferometric techniques, nanometer changes can be detected.
Applications.
Applications for IRIS include microarray format immunoassays, single nucleotide polymorphism (SNP) detection, pathogen detection and bio-defense monitoring, kinetic analysis of biomolecular interactions, and general biomolecular interaction studies for research applications.


Mavis B. Carroll

Mavis Bowler Carroll (October 12, 1917 – March 7, 2009) was an American statistician who pioneered the industrial use of statistics in her work at General Foods.
Carroll finished high school at age 16 and attended the New Jersey College for Women on a scholarship. She played on the school basketball team, and earned a bachelor's degree in mathematics there in 1938. She worked as a code breaker during World War II and at the Squibb Institute for Medical Research in New Brunswick, New Jersey in the early 1950s.
Later, she worked at the General Foods Research Center, where she became Section Head in 1958 and, by the 1960s, the head of their division of mathematical and statistical services. Her work at General Foods included the design and analysis of taste tests, with each variation of a food product typically being tested by a panel of 50 tasters (evenly split by gender) who rated the foods on a scale of +3 to −3. In order to keep the total number of tasters manageable, a careful design of experiments was needed to control the number of different food variations to be tested.
Carroll was secretary of the American Society for Testing and Materials for 1960 to 1962.
In 1971, Carroll was elected as a Fellow of the American Statistical Association.
Carroll died of pneumonia on March 7, 2009, in Wilmington, North Carolina.


Graduated cylinder

A graduated cylinder, also known as measuring cylinder or mixing cylinder is a common piece of laboratory equipment used to measure the volume of a liquid. It has a narrow cylindrical shape. Each marked line on the graduated cylinder represents the amount of liquid that has been measured.
Materials and structure.
Large graduated cylinders are usually made of polypropylene for its excellent chemical resistance or polymethylpentene for its transparency, making them lighter and less fragile than glass. Polypropylene (PP) is easy to repeatedly autoclave; however, autoclaving in excess of about (depending on the chemical formulation: typical commercial grade polypropylene melts in excess of ), can warp or damage polypropylene graduated cylinders, affecting accuracy.
A traditional graduated cylinder is usually narrow and tall so as to increase the accuracy and precision of volume measurement. It has a plastic or glass base (stand, foot, support) and a "spout" for easy pouring of the measured liquid. An additional version is wide and low.
Mixing cylinders have ground glass joints instead of a spout, so they can be closed with a stopper or connect directly with other elements of a manifold. With this kind of cylinder, the metered liquid does not pour directly, but is often removed using a Cannula. A graduated cylinder is meant to be read with the surface of the liquid at eye level, where the center of the meniscus shows the measurement line. Typical capacities of graduated cylinders are from 10 mL to 1000 mL.
Common uses.
Graduated cylinders are often used to measure the volume of a liquid. Graduated cylinders are generally more accurate and precise than laboratory flasks and beakers, but they should not be used to perform volumetric analysis; volumetric glassware, such as a volumetric flask or volumetric pipette, should be used, as it is even more accurate and precise. Graduated cylinders are sometimes used to measure the volume of a solid indirectly by measuring the displacement of a liquid.
Scales and accuracy.
For accuracy the volume on graduated cylinders is depicted on scales with 3 significant digits: 100mL cylinders have 1ml grading divisions while 10mL cylinders have 0.1 mL grading divisions.
Two classes of accuracy exist for graduated cylinders. Class A has double the accuracy of class B.
Cylinders can have single or double scales. Single scales allow to read the volume from top to bottom (filling volume) while double scale cylinders allow reading for filling and pouring (reverse scale).
Graduated cylinders are calibrated either “to contain” (indicated liquid volume inside the cylinder) and marked as "TC" or “to deliver” (indicated liquid volume poured out, accounting for liquid traces left in the cylinder) and marked “TD”. Formerly the tolerances for “to deliver” and “to contain” cylinders are distinct; however now these are the same. Also, the international symbols “IN” and “EX” are more likely to be used instead of “TC” and “TD” respectively.
Measurement.
To read the volume accurately, the observation must be at an eye level and read at the bottom of a meniscus of the liquid level.
The main reason as to why the reading of the volume is done via meniscus is due to the nature of the liquid in a closed surrounded space. By nature, liquid in the cylinder would be attracted to the wall around it through molecular forces. This forces the liquid surface to develop either a convex or concave shape, depending on the type of the liquid in the cylinder. Reading the liquid at the bottom part of a concave or the top part of the convex liquid is equivalent to reading the liquid at its meniscus. From the picture, the level of the liquid will be read at the bottom of the meniscus, which is the concave. The most accurate of the reading that could be done here is reduced down to 1 mL due to the given means of measurement on the cylinder. From this, the derived error would be one tenth of the least figure. For instance, if the reading is done and the value calculated is set to be 36.5 mL. The error, give or take 0.1 mL, must be included too. Therefore, the more precise value equates to 36.5 formula_1 0.1; 36.4 or 36.6 mL. Therefore, there are 3 significant figures can be read from the given graduated cylinder picture. Another example, if the reading is done and the value calculated is set to be 40.0 mL. The precise value would be 40.0 formula_1 0.1; 40.1 or 39.9 mL.


Instruments by Harry Partch

The American composer Harry Partch (1901-1974) composed using scales of unequal intervals in just intonation, derived from the natural Harmonic series; these scales allowed for more tones of smaller intervals than in the standard Western tuning, which uses twelve equal intervals. One of Partch's scales has 43 tones to the octave. To play this music, he built many unique instruments, with names such as the Chromelodeon, the Quadrangularis Reversum, and the Zymo-Xyl.
Partch called himself "a philosophic music-man seduced into carpentry". The path towards Partch's use of many unique instruments was a gradual one. Partch began in the 1920s using traditional instruments, and wrote a string quartet in just intonation (now lost). He had his first specialized instrument built for him in 1930—the Adapted Viola, a viola with a cello's neck fitted on it.
He re-tuned the reeds of several reed organs and labeled the keys with a color code. The first was called the "Ptolemy", in tribute to the ancient music theorist Claudius Ptolemaeus, whose musical scales included ratios of the 11-limit, as Partch's did. The others were called "Chromelodeons", a portmanteau of "chrome" (meaning "color") and "melodeon".
Most of Partch's works used the instruments he created exclusively. Some works made use of unaltered standard instruments such as oboe, clarinet, or cello, and "Revelation in the Courtyard Park" (1960) used an unaltered small wind band.
In 1991, Dean Drummond became the custodian of the original Harry Partch instrument collection until his death in 2013. In 1999 the instruments began a residency at Montclair State University in Montclair, New Jersey which lasted until November 2014 when they moved to University of Washington in Seattle. They are currently under the care of Charles Corey.
Those who have duplicated partial sets of Partch instruments include John Schneider, whose West Coast ensemble includes replicas of the Kithara, Surrogate Kithara, Cloud-Chamber Bowls, Adapted Guitars, Adapted Viola, Diamond Marimba, Bass Marimba, Chromelodeon, and two Harmonic Canons.
Adapted Guitars.
Partch built two steel-string guitars: the six-string Adapted Guitar I, and the ten-string Adapted Guitar II (played with a slide). Partch first started experimenting with such instruments in 1934, and the Adapted Guitar I first appeared in "Barstow" in 1941. In 1945, he began using amplification for both instruments.
Adapted Viola.
The Adapted Viola is the earliest extant instrument created by Partch. It is made from a cello fingerboard neck attached to the body of a viola. It also includes a changeable bridge which allows triple stops, i.e. full triads, to be sustained. Partch hammered brads into the fingerboard to aid with finding fingerings. The Adapted Viola was constructed in New Orleans with the assistance of an Edward Benton, a local violin maker. Partch originally called it the Monophone, but by 1933 it had become known as the Adapted Viola.
Partch tuned the Adapted Viola an octave below the violin and the brads inserted into the instrument fingerboard are placed at ratios commonly used in Partch's works. In playing the instrument, Partch called for a "one-finger technique," which is "much closer to the spirit of Indian vina playing than it is to the pipe organ." Specifically, he desired that notes should be approached by gliding from tone to tone:
As Partch's first instrument, the Adapted Viola is used heavily in many of his early mature compositions. In works such as "Seventeen Lyrics by Li Po" and "Two Psalms" the music is scored only for Adapted Viola and intoning voice.
Bamboo Marimbas.
Nicknamed "Boo" and "Boo II", the Bamboo Marimbas are marimbas made of bamboo, using the concept of a tongued resonator to produce the tones.
The Boo I was first built in 1955. Some of the bamboo was replaced with larger-diameter pieces in 1963. It has a total of 64 bamboo resonators, organized into six ranks. The back ends of the tubes are sealed.
Boo II was built in 1971. It also has 64 tubes, but the tubes are open at both ends. The tongues cut into the bamboo are approximately 1/6 of the length of the tube in order to produce a harmonic at 6/5 of the fundamental.
Bass Marimba and Marimba Eroica.
The Bass Marimba and Marimba Eroica have more traditional linear layouts and are very low in pitch.
The Bass Marimba was first built in 1950. It has eleven bars made of Sitka spruce. The lowest bar corresponds to a piano C2. It can be played with mallets or by slapping with the pads of the fingers.
The Marimba Eroica was built in 1954. It comprises four bars of Sitka spruce on top of large resonator boxes. The lowest bar sounds at 22 Hz, approximately the F below the lowest note of a piano.
Chromelodeons.
The Chromelodeons are pump organs modified by Partch to conform to his tonality system. Chromelodeon I was adapted in 1945 from a 73-key pump organ. Chromelodeon II was adapted in 1959 from an 88-key pump organ. Both keyboards have colored and numbered labels representing ratios of the tuning system.
Cloud-Chamber Bowls.
The Cloud-Chamber Bowls are a set of , 16-inch diameter Pyrex bowls cut from carboys, suspended in a frame. The carboys were originally sourced from the Berkeley Radiation Laboratory, where they were used in the construction of cloud chambers. It was first built in 1950.
Diamond Marimba.
The Diamond Marimba is a marimba with keys arranged in a physical manifestation of the 11-limit tonality diamond. Partch first built it in 1946.
Eucal Blossom.
The Eucal Blossom is a bamboo marimba with 33 resonators in three rows of eleven, supported by a branch of eucalyptus. It was first built in 1964.
Gourd Tree and Cone Gongs.
Twelve temple bells bolted to gourd resonators on a bar of eucalyptus, and two Douglas Aircraft bomber nosecones. First built in 1964.
Harmonic Canons.
The Harmonic Canons (from the same root as "qanún") are 44-stringed sonometer instruments with complex systems of movable bridges that were mostly positioned by Partch on harmonic nodal positions to get a just intoned harmonic relation between the left and right string part. They are tuned differently depending on the piece, and are played with fingers or picks, or in some cases, unique mallets.
Harmonic Canon I (1945), II (1953), III (1965).
Kitharas.
Named after their inspiration, the Greek kithara, the Kitharas are upright 72-stringed instruments, tuned by sliding pyrex rods underneath the strings, and played with fingers or a variety of plectra.
The Kithara I was first built in 1938, and restored in 1972. The Surrogate Kithara was built in 1953, and the Kithara II in 1954.
Mazda Marimba.
The Mazda Marimba is made of Mazda light bulbs and named after the Zoroastrian god Ahura Mazda.
Quadrangularis Reversum.
Partch built the Quadrangularis Reversum in 1965, about twenty years after the Diamond Marimba. The central section's 36 African padauk blocks are an upside-down, mirrored version of the Diamond Marimba—hence "Reversum". This reverse possibility was shown to Partch by Erv Wilson who helped with its construction. To the left and right are sets of ten alto-register blocks. Bamboo resonators are under the blocks. Partch's initial plan, abandoned due to cost, was to use square bamboo ("C. quadrangularis") for the resonators—hence the first part of the instrument's name. The curved uprights are eucalyptus, and the bar across the top is intended to evoke a torii. The instrument is quite large at across the top and tall.
Spoils of War.
The Spoils of War is a collection of several instruments, including more Cloud Chamber Bowls, artillery shell casings, metal "whang-guns", a Pernambuco wood block, and a gourd. First built in 1950.
Zymo-Xyl.
The Zymo-Xyl is an oak-block xylophone augmented with tuned liquor and wine bottles, Ford hubcaps, and an aluminum ketchup bottle. The name is from the Greek "zymo-" for "fermentation", and "xylo-" or "xyl-" for "wood". First built in 1963.


Power of a test

The power of a binary hypothesis test is denoted by "(1−β)" and is the probability of a "true positive". It is the probability that the test correctly rejects the null hypothesis (formula_1) when a specific alternative hypothesis (formula_2) is true. It is the probability of avoiding a "false negative", otherwise known as a type II error. The statistical power ranges from 0 to 1, and as statistical power increases, the size of "β" - the probability of making a type II error by wrongly failing to reject the null hypothesis - decreases.
Notation.
This article uses the following notation
Description.
For a type II error probability of , the corresponding statistical power is 1 − . For example, if experiment E has a statistical power of 0.7, and experiment F has a statistical power of 0.95, then there is a stronger probability that experiment E had a type II error than experiment F. This reduces experiment E's sensitivity to detect significant effects. However, experiment E is consequently more reliable than experiment F due to its lower probability of a type I error. It can be equivalently thought of as the probability of accepting the alternative hypothesis (formula_2) when it is true — that is, the ability of a test to detect a specific effect, if that specific effect actually exists. Thus,
If formula_2 is not an equality but rather simply the negation of formula_1 (so for example with formula_7 for some unobserved population parameter formula_8 we have simply formula_9) then power cannot be calculated unless probabilities are known for all possible values of the parameter that violate the null hypothesis. Thus one generally refers to a test's power "against a specific alternative hypothesis".
As the power increases, there is a decreasing probability of a type II error, also called the "false negative rate" () since the power is equal to 1 − . A similar concept is the type I error probability, also referred to as the "false positive rate" or the level of a test under the null hypothesis.
In the context of binary classification, the power of a test is called its "statistical sensitivity", its "true positive rate", or its "probability of detection".
Power analysis.
A related concept is "power analysis". Power analysis can be used to calculate the minimum sample size required so that one can be reasonably likely to detect an effect of a given size. For example: "How many times do I need to toss a coin to conclude it is rigged by a certain amount?" Power analysis can also be used to calculate the minimum effect size that is likely to be detected in a study using a given sample size. In addition, the concept of power is used to make comparisons between different statistical testing procedures: for example, between a parametric test and a nonparametric test of the same hypothesis.
Background.
Statistical tests use data from samples to assess, or make inferences about, a statistical population. In the concrete setting of a two-sample comparison, the goal is to assess whether the mean values of some attribute obtained for individuals in two sub-populations differ. For example, to test the null hypothesis that the mean scores of men and women on a test do not differ, samples of men and women are drawn, the test is administered to them, and the mean score of one group is compared to that of the other group using a statistical test such as the two-sample "z"-test. The power of the test is the probability that the test will find a statistically significant difference between men and women, as a function of the size of the true difference between those two populations.
Factors influencing power.
Statistical power may depend on a number of factors. Some factors may be particular to a specific testing situation, but at a minimum, power nearly always depends on the following three factors:
A significance criterion is a statement of how unlikely a positive result must be, if the null hypothesis of no effect is true, for the null hypothesis to be rejected. The most commonly used criteria are probabilities of 0.05 (5%, 1 in 20), 0.01 (1%, 1 in 100), and 0.001 (0.1%, 1 in 1000). If the criterion is 0.05, the probability of the data implying an effect at least as large as the observed effect when the null hypothesis is true must be less than 0.05, for the null hypothesis of no effect to be rejected. One easy way to increase the power of a test is to carry out a less conservative test by using a larger significance criterion, for example 0.10 instead of 0.05 . This increases the chance of rejecting the null hypothesis (obtaining a statistically significant result) when the null hypothesis is false; that is, it reduces the risk of a type II error (false negative regarding whether an effect exists). But it also increases the risk of obtaining a statistically significant result (rejecting the null hypothesis) when the null hypothesis is not false; that is, it increases the risk of a type I error (false positive).
The magnitude of the effect of interest in the population can be quantified in terms of an effect size, where there is greater power to detect larger effects. An effect size can be a direct value of the quantity of interest, or it can be a standardized measure that also accounts for the variability in the population. For example, in an analysis comparing outcomes in a treated and control population, the difference of outcome means formula_10 would be a direct estimate of the effect size, whereas formula_11 would be an estimated standardized effect size, where formula_12 is the common standard deviation of the outcomes in the treated and control groups. If constructed appropriately, a standardized effect size, along with the sample size, will completely determine the power. An unstandardized (direct) effect size is rarely sufficient to determine the power, as it does not contain information about the variability in the measurements.
The sample size determines the amount of sampling error inherent in a test result. Other things being equal, effects are harder to detect in smaller samples. Increasing sample size is often the easiest way to boost the statistical power of a test. How increased sample size translates to higher power is a measure of the efficiency of the test — for example, the sample size required for a given power.
The precision with which the data are measured also influences statistical power. Consequently, power can often be improved by reducing the measurement error in the data. A related concept is to improve the "reliability" of the measure being assessed (as in psychometric reliability).
The design of an experiment or observational study often influences the power. For example, in a two-sample testing situation with a given total sample size , it is optimal to have equal numbers of observations from the two populations being compared (as long as the variances in the two populations are the same). In regression analysis and analysis of variance, there are extensive theories and practical strategies for improving the power based on optimally setting the values of the independent variables in the model.
Interpretation.
Although there are no formal standards for power (sometimes referred to as ), most researchers assess the power of their tests using  = 0.80 as a standard for adequacy. This convention implies a four-to-one trade off between -risk and -risk. ( is the probability of a type II error, and α is the probability of a type I error; 0.2 and 0.05 are conventional values for and ). However, there will be times when this 4-to-1 weighting is inappropriate. In medicine, for example, tests are often designed in such a way that no false negatives (type II errors) will be produced. But this inevitably raises the risk of obtaining a false positive (a type I error). The rationale is that it is better to tell a healthy patient "we may have found something—let's test further," than to tell a diseased patient "all is well."
Power analysis is appropriate when the concern is with the correct rejection of a false null hypothesis. In many contexts, the issue is less about determining if there is or is not a difference but rather with getting a more refined estimate of the population effect size. For example, if we were expecting a population correlation between intelligence and job performance of around 0.50, a sample size of 20 will give us approximately 80% power ( = 0.05, two-tail) to reject the null hypothesis of zero correlation. However, in doing this study we are probably more interested in knowing whether the correlation is 0.30 or 0.60 or 0.50 . In this context we would need a much larger sample size in order to reduce the confidence interval of our estimate to a range that is acceptable for our purposes. Techniques similar to those employed in a traditional power analysis can be used to determine the sample size required for the width of a confidence interval to be less than a given value.
Many statistical analyses involve the estimation of several unknown quantities. In simple cases, all but one of these quantities are nuisance parameters. In this setting, the only relevant power pertains to the single quantity that will undergo formal statistical inference. In some settings, particularly if the goals are more "exploratory", there may be a number of quantities of interest in the analysis. For example, in a multiple regression analysis we may include several covariates of potential interest. In situations such as this where several hypotheses are under consideration, it is common that the powers associated with the different hypotheses differ. For instance, in multiple regression analysis, the power for detecting an effect of a given size is related to the variance of the covariate. Since different covariates will have different variances, their powers will differ as well.
Any statistical analysis involving multiple hypotheses is subject to inflation of the type I error rate if appropriate measures are not taken. Such measures typically involve applying a higher threshold of stringency to reject a hypothesis in order to compensate for the multiple comparisons being made ("e.g." as in the Bonferroni method). In this situation, the power analysis should reflect the multiple testing approach to be used. Thus, for example, a given study may be well powered to detect a certain effect size when only one test is to be made, but the same effect size may have much lower power if several tests are to be performed.
It is also important to consider the statistical power of a hypothesis test when interpreting its results. A test's power is the probability of correctly rejecting the null hypothesis when it is false; a test's power is influenced by the choice of significance level for the test, the size of the effect being measured, and the amount of data available. A hypothesis test may fail to reject the null, for example, if a true difference exists between two populations being compared by a t-test but the effect is small and the sample size is too small to distinguish the effect from random chance. Many clinical trials, for instance, have low statistical power to detect differences in adverse effects of treatments, since such effects may be rare and the number of affected patients small.
"A priori" vs. "post hoc" analysis.
Power analysis can either be done before ("a priori" or prospective power analysis) or after ("post hoc" or retrospective power analysis) data are collected. "A priori" power analysis is conducted prior to the research study, and is typically used in estimating sufficient sample sizes to achieve adequate power. "Post-hoc" analysis of "observed power" is conducted after a study has been completed, and uses the obtained sample size and effect size to determine what the power was in the study, assuming the effect size in the sample is equal to the effect size in the population. Whereas the utility of prospective power analysis in experimental design is universally accepted, post hoc power analysis is fundamentally flawed. Falling for the temptation to use the statistical analysis of the collected data to estimate the power will result in uninformative and misleading values. In particular, it has been shown that "post-hoc" "observed power" is a one-to-one function of the "p"-value attained. This has been extended to show that all "post-hoc" power analyses suffer from what is called the "power approach paradox" (PAP), in which a study with a null result is thought to show "more" evidence that the null hypothesis is actually true when the "p"-value is smaller, since the apparent power to detect an actual effect would be higher. In fact, a smaller "p"-value is properly understood to make the null hypothesis "relatively" less likely to be true.
Application.
Funding agencies, ethics boards and research review panels frequently request that a researcher perform a power analysis, for example to determine the minimum number of animal test subjects needed for an experiment to be informative. In frequentist statistics, an underpowered study is unlikely to allow one to choose between hypotheses at the desired significance level. In Bayesian statistics, hypothesis testing of the type used in classical power analysis is not done. In the Bayesian framework, one updates his or her prior beliefs using the data obtained in a given study. In principle, a study that would be deemed underpowered from the perspective of hypothesis testing could still be used in such an updating process. However, power remains a useful measure of how much a given experiment size can be expected to refine one's beliefs. A study with low power is unlikely to lead to a large change in beliefs.
Example.
The following is an example that shows how to compute power for a randomized experiment: Suppose the goal of an experiment is to study the effect of a treatment on some quantity, and compare research subjects by measuring the quantity before and after the treatment, analyzing the data using a paired t-test. Let formula_13 and formula_14 denote the pre-treatment and post-treatment measures on subject formula_15, respectively. The possible effect of the treatment should be visible in the differences formula_16 which are assumed to be independently distributed, all with the same expected mean value and variance.
The effect of the treatment can be analyzed using a one-sided t-test. The null hypothesis of no effect will be that the mean difference will be zero, i.e. formula_17 In this case, the alternative hypothesis states a positive effect, corresponding to formula_18 The test statistic is:
where
 is the sample size and formula_21 is the standard error. The test statistic under the null hypothesis follows a Student t-distribution with the additional assumption that the data is identically distributed formula_22. Furthermore, assume that the null hypothesis will be rejected at the significance level of formula_23 Since is large, one can approximate the t-distribution by a normal distribution and calculate the critical value using the quantile function formula_24, the inverse of the cumulative distribution function of the normal distribution. It turns out that the null hypothesis will be rejected if
Now suppose that the alternative hypothesis is true and formula_26. Then, the power is
For large , formula_28 approximately follows a standard normal distribution when the alternative hypothesis is true, the approximate power can be calculated as
According to this formula, the power increases with the values of the parameter formula_30 For a specific value of formula_31 a higher power may be obtained by increasing the sample size .
It is not possible to guarantee a sufficient large power for all values of formula_32 as formula_31 may be very close to 0. The minimum (infimum) value of the power is equal to the confidence level of the test, formula_34 in this example 0.05 . However, it is of no importance to distinguish between formula_35 and small positive values. If it is desirable to have enough power, say at least 0.90, to detect values of formula_36 the required sample size can be calculated approximately:
from which it follows that
Hence, using the quantile function
where formula_40 is a standard normal quantile; refer to the Probit article for an explanation of the relationship between formula_41 and z-values.
Extension.
Bayesian power.
In the frequentist setting, parameters are assumed to have a specific value which is unlikely to be true. This issue can be addressed by assuming the parameter has a distribution. The resulting power is sometimes referred to as Bayesian power which is commonly used in clinical trial design.
Predictive probability of success.
Both frequentist power and Bayesian power use statistical significance as the success criterion. However, statistical significance is often not enough to define success. To address this issue, the power concept can be extended to the concept of predictive probability of success (PPOS). The success criterion for PPOS is not restricted to statistical significance and is commonly used in clinical trial designs.
Software for power and sample size calculations.
Numerous free and/or open source programs are available for performing power and sample size calculations. These include


740 Cantabia

740 Cantabia is a minor planet orbiting the Sun.
Cantabia is a contraction of Cantabrigia, Latin for Cambridge, named in honor of Cambridge, Massachusetts.


857 Glasenappia

857 Glasenappia is a minor planet orbiting the Sun. It was named after Russian astronomer Sergey Glazenap, who was often referred to as "S. de Glasenapp" in pre-Revolution publications.


Hypolydian mode

The Hypolydian mode, literally meaning "below Lydian", is the common name for the sixth of the eight church modes of medieval music theory. The name is taken from Ptolemy of Alexandria's term for one of his seven "tonoi", or transposition keys. This mode is the plagal counterpart of the authentic fifth mode.
In medieval theory the Hypolydian mode was described either as (1) the diatonic octave species from C to the C an octave higher, divided at the final F (C–D–E–F + F–G–A–B–C) or (2) a mode with F as final and an ambitus from the C below the final to the D above it. The third above the final, A—corresponding to the reciting tone or "tenor" of the sixth psalm tone—was regarded as having an important melodic function in this mode. The sequence of intervals was therefore divided by the final into a lower tetrachord of tone-tone-semitone, and an upper pentachord of tone-tone-tone-semitone. However, from as early as the time of Hucbald the Hypolydian mode—even more than the corresponding authentic mode, the Lydian—was characterized by the predominance of B instead of B as the fourth degree above the final. The melodic centering on F and A, as well as the use of B instead of B, is illustrated in the accompanying example from the Requiem Mass introit, "Requiem aeternam".
Finer distinctions among the scale degree are sometimes made, with the D below the final called the "mediant", the lowest note, C, the "participant" (a tone functioning as an auxiliary to the mediant), the G, B, and B the "conceded modulations" (subsidiary degrees), and the lowest C, the final, F, and (rarely) the D the "absolute initials".


4426 Roerich


235 Carolina

Carolina (minor planet designation: 235 Carolina) is a sizeable Main belt asteroid. It is an S-type asteroid.
It was discovered by Johann Palisa on 28 November 1883 in Vienna.
The asteroid was named after Caroline Island, now part of Kiribati.


Secondary Level English Proficiency test

The Secondary Level English Proficiency Test® was a test created by ETS and administered by American middle and high schools to applicants whose first language is not English.
The SLEP® test was discontinued June 30, 2012 and replaced by the TOEFL® Junior™ test. However, a limited number of private schools continue to use the SLEP test. In addition, a large number of schools that formerly used SLEP began using the iTEP SLATE exam by Boston Educational Services after June 2012.


Shure SM58

The Shure SM58 is a professional cardioid dynamic microphone, commonly used in live vocal applications. Produced since 1966 by Shure Incorporated, it has built a strong reputation among musicians for its durability and sound, and half a century later it is still considered the industry standard for live vocal performance microphones. The SM58 and its sibling, the SM57, are the best-selling microphones in the world. The SM stands for Studio Microphone.
Like all directional microphones, the SM58 is subject to proximity effect, a low frequency boost when used close to the source. The cardioid response reduces pickup from the side and rear, helping to avoid feedback onstage. There are wired (with and without on/off switch) and wireless versions. The wired version provides balanced audio through a male XLR connector. The SM58 uses an internal shock mount to reduce handling noise.
A distinctive feature of the SM58 is its pneumatic suspension system for the microphone capsule. The capsule, a readily replaceable component, is surrounded by a soft rubber balloon, rather than springs or solid rubber. This gives notably good isolation from handling noise; one reason for its being a popular microphone for stage vocalists. Microphones with this feature are intended primarily for hand-held use, rather than on a stand or for instrument miking.
The SM58 is unswitched, while the otherwise identical SM58S has a sliding on-off switch on the body. Other suffixes refer to any accessories supplied with the microphone: when a cable is provided, the model is actually SM58-CN, while the SM58-LC has no provided cable; the SM58-X2u kit consists of the SM58-LC and an inline X2u XLR-to-USB signal adaptor (capable of providing phantom power for condenser microphones, and offering an in-built headphone jack for monitoring).
Specifications.
Type: Dynamic (moving coil)
Counterfeiting.
The SM58 and SM57 have been extensively counterfeited. Most of these counterfeit microphones are at least functional, but have poorer performance and do not have the pneumatic suspension. There are many other subtle details which can reveal most of these fakes.


Rydberg ionization spectroscopy

Rydberg ionization spectroscopy is a spectroscopy technique in which multiple photons are absorbed by an atom causing the removal of an electron to form an ion.
Resonance ionization spectroscopy.
The ionization threshold energy of atoms and small molecules are typically larger than the photon energies that are most easily available experimentally. However, it can be possible to span this ionization threshold energy if the photon energy is resonant with an intermediate electronically excited state. While it is often possible to observe the lower Rydberg levels in conventional spectroscopy of atoms and small molecules, Rydberg states are even more important in laser ionization experiments. Laser spectroscopic experiments often involve ionization through a photon energy resonance at an intermediate level, with an unbound final electron state and an ionic core. On resonance for phototransitions permitted by selection rules, the intensity of the laser in combination with the excited state lifetime makes ionization an expected outcome. This RIS approach and variations permit sensitive detection of specific species.
Low Rydberg levels and resonance enhanced multiphoton ionization.
High photon intensity experiments can involve multiphoton processes with the absorption of integer multiples of the photon energy. In experiments that involve a multiphoton resonance, the intermediate is often a Rydberg state, and the final state is often an ion. The initial state of the system, photon energy, angular momentum and other selection rules can help in determining the nature of the intermediate state. This approach is exploited in resonance enhanced multiphoton ionization spectroscopy (REMPI). An advantage of this spectroscopic technique is that the ions can be detected with almost complete efficiency and even resolved for their mass. It is also possible to gain additional information by performing experiments to look at the energy of the liberated photoelectron in these experiments. (Compton and Johnson pioneered the development of REMPI)
Near-threshold Rydberg levels.
The same approach that produces an ionization event can be used to access the dense manifold of near-threshold Rydberg states with laser experiments. These experiments often involve a laser operating at one wavelength to access the intermediate Rydberg state and a second wavelength laser to access the near-threshold Rydberg state region. Because of the photoabsorption selection rules, these Rydberg electrons are expected to be in highly elliptical angular momentum states. It is the Rydberg electrons excited to nearly circular angular momentum states that are expected to have the longest lifetimes. The conversion between a highly elliptical and a nearly circular near-threshold Rydberg state might happen in several ways, including encountering small stray electric fields.
Zero electron kinetic energy spectroscopy.
Zero electron kinetic energy (ZEKE) spectroscopy was developed with the idea of collecting only the resonance ionization photoelectrons that have extremely low kinetic energy. The technique involves waiting for a period of time after a resonance ionization experiment and then pulsing an electric field to collect the lowest energy photoelectrons in a detector. Typically, ZEKE experiments utilize two different tunable lasers. One laser photon energy is tuned to be resonant with the energy of an intermediate state. (This may be resonant with an excited state at a multiphoton transition.) Another photon energy is tuned to be close to the ionization threshold energy. The technique worked extremely well and demonstrated energy resolution that was significantly better than the laser bandwidth. It turns out that it was not the photoelectrons that were detected in ZEKE. The delay between the laser and the electric field pulse selected the longest lived and most circular Rydberg states closest to the energy of the ion core. The population distribution of surviving long-lived near threshold Rydberg states is close to the laser energy bandwidth. The electric field pulse stark shifts the near-threshold Rydberg states and vibrational autoionization occurs. ZEKE has provided a significant advance in the study of the vibrational spectroscopy of molecular ions. Schlag, Peatman and Müller-Dethlefs originated ZEKE spectroscopy.
Mass analyzed threshold ionization.
Mass analyzed threshold ionization (MATI) was developed with idea of collecting the mass of the ions in a ZEKE experiment.
MATI offered a mass resolution advantage to ZEKE. Because MATI also exploits vibrational autoionization of near-threshold Rydberg states, it also can offer a comparable resolution with the laser bandwidth. This information can be indispensable in understanding a variety of systems.
Photo-induced Rydberg ionization.
Photo-induced Rydberg ionization (PIRI) was developed following REMPI experiments on electronic autoionization of low-lying Rydberg states of carbon dioxide. In REMPI photoelectron experiments, it was determined that a two-photon ionic core photoabsorption process (followed by prompt electronic autoionization) could dominate the direct single photon absorption in the ionization of some Rydberg states of carbon dioxide. These sorts of two excited electron systems had already been under study in the atomic physics, but there the experiments involved high order Rydberg states. PIRI works because electronic autoionization can dominate direct photoionization (photoionization). The circularized near-threshold Rydberg state is more likely to undergo a core photoabsorption than to absorb a photon and directly ionize the Rydberg state. PIRI extends the near-threshold spectroscopic techniques to allow access to the electronic states (including dissociative molecular states and other hard to study systems) as well as the vibrational states of molecular ions.


663 Gerlinde

663 Gerlinde is a minor planet orbiting the Sun.


Proton-enhanced nuclear induction spectroscopy

Proton-enhanced nuclear induction spectroscopy (PENIS), also called cross-polarisation (CP), is a nuclear magnetic resonance technique invented by Michael Gibby and Alexander Pines (who named it specifically for the inappropriate acronym) while they were graduate students in the lab of Professor John S. Waugh at the Massachusetts Institute of Technology. Due to the suggestive nature of its acronym, the latter name is used more often. This technique is an integral part of most solid-state NMR experiments involving spin-1/2 nuclei.
PENIS was one of the first of Pines' experiments transferring spin orientation from one atomic nucleus to another, which has been one of the running themes throughout his career as a leading pioneer in the applications of NMR to the study of non-liquid samples. The PENIS technique was patented in 1972.
Technique.
In this technique the natural polarization of an abundant spin (1H, the "proton" which begins the name of the technique) is exploited to increase the polarization of a rare spin (such as 13C) by irradiating the sample with radio waves at the frequency which corresponds to the difference between the rotation frequencies of the two different spins.
Besides its utility for boosting signals from dilute spins, transferring spin-polarization can also be used by surface-scientists to selectively enhance the spin-polarization of molecules on a sample's surface over the spins in the bulk by transferring spin-polarization from a gas to the surface.


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