Nicaraguan units of measurement

A number of units of measurement were used in Nicaragua to measure measurements in mass, area, volume, etc. In Nicaragua, the metric system was adopted in 1910, and has been compulsory since 1912, by a joint convention between Costa Rica, Guatemala, Honduras, Nicaragua and El Salvador.
Pre-metric units.
Before the metric system, a number of modified Spanish (i.e. Spanish Castilian), English and local units were used.
Mass.
Several units were used to measure mass in the above five countries. Some of these units are given below:
1 caja = 16 kg
1 fanega = 92 kg
1 carga = 161 kg
Area.
Several units were used to measure area in these countries. One manzana was equal to 10,000 square varas or 6987.4 m2. (A vara was an obsolete Spanish unit of length equal to 0.8359 m.) One caballeria was equal to 64 manzanas.
Volume.
Several units were used to measure volume in these countries. One botella was equal to 0.63 to 0.67 litres. One cajuela was equal to 16.6 litres. However the capacity of one cuartillo is very variable.


Angela Dale

Angela Dale (born 1945) is a British social scientist and statistician whose research has involved the secondary analysis of government survey data, and the study of women in the workforce. Formerly Deputy Director of the Social Statistics Research Unit of City, University of London, and Professor of Quantitative Research and Director of the Cathie Marsh Centre for Census and Survey Research at the University of Manchester, she is now a professor emerita at Manchester.
Selected publications.
Dale is an author of the books;
She is an editor of
She has also published highly cited journal papers on women in the workforce including
Recognition.
Dale is a Fellow of the Academy of Social Sciences. She was named to the Order of the British Empire in the 2006 New Year Honours "for services to social science". In 2006, Dale won the West Medal of the Royal Statistical Society, given "for outstanding contributions to the development or communication of official statistics".


Indian Police Service Limited Competitive Examination

To face the shortage of Indian Police Service officers in India as a result the high attrition in the Indian Police Service, the Ministry of Home Affairs proposed the formation of Indian Police Service Limited Competitive Examination to be conducted by UPSC. IPS Limited Competitive Examination was held for the first time in 2012. This is in addition to the Civil Services Examination conducted by UPSC itself, for recruitment to the various civil services including Indian Police Service.The Central Administrative Tribunal(CAT) has struck down the examination following the challenge by some state cadre police officers. Consequent to the CAT verdict, UPSC has withheld the declaration of final results of 2012 examination. Now the Ministry of Home Affairs is trying to sort out the legal matters as soon as possible.
Eligibility Conditions.
(a)The candidate must hold a degree of any of Universities incorporated by an Act of the Central or State Legislature in India or other educational institutions established by an Act of Parliament or declared to be deemed as a University Under Section-3 of the University Grants Commission Act, 1956, or possess an equivalent qualification.
(b) A candidate must not have attained the age of 32 years for General Category, 35 years for Other Backward Classes category candidates and 37 years for candidates belonging to a Scheduled Caste or Scheduled Tribe.
Part B - Main Examination - Optional
Paper-I
One of the Indian Languages to be selected by the candidate from the 22 languages included in the VIIIth Schedule to the Constitution (Qualifying Paper) am during the job
300 Marks
Paper-II
English (Qualifying Paper)
300 Marks
Paper-III
Essay [in the medium you choose]
Papers
Papers VI, VII, VIII & IX X
Any two subjects (each having 2 papers) to be selected from the prescribed optional subjects (300 marks for each paper)
1200 Mark
Scheme of Examination.
The Examination will comprise two components viz. Written Examination and Interview for Personality Test.
Note 3: The objective from papers will be qualifying in nature.
Brief Syllabus.
Paper I:- General Studies covering Current affairs, History of India, Geography of India and the world, Indian polity and Governance, Economic and social development, Environmental issues, General Science
get paper II :- Aptitude test comprising Comprehension, Interpersonal skills, Logical reasoning and analytical ability, Decision making and problem-solving, General mental ability, Basic numeracy, and English Language Comprehension skills
Paper III :- English Language paper. This paper would be of Matriculation standard and qualifying in nature only. Its marks will not be counted for the preparation of merit ranking.
Paper IV :- Essay paper. It will comprise two essays, one on the security aspect and the other on the various developmental aspects of the society.
Paper V:- General Studies paper covering various aspects like Elementary Principles of Public Law, State Policy, Fundamental Rights, Human Rights, Disaster Management, National Security, etc.
Part B
PAPERS OF DESCRIPTIVE TYPE
Paper III : English (200 marks / 3 hours duration):- This will be a qualifying test only
of Matriculation or equivalent standard.
The aim of the paper is to test the candidate’s ability to read and understand serious
discursive prose, and to express his ideas clearly and correctly, in English.
The pattern of questions would be broad as follows (indicative only) :—
UPSC Prelims Syllabus
Syllabus for GS Paper (Prelims Paper I)
Current events of national and international importance.
History of India and Indian National Movement.
Indian and World Geography-Physical, Social, Economic Geography of India and the World.
Indian Polity and Governance – Constitution, Political System, Panchayati Raj, Public Policy, Rights Issues, etc.
Economic and Social Development – Sustainable Development, Poverty, Inclusion, Demographics, Social Sector initiatives, etc.
General issues on Environmental Ecology, Biodiversity and Climate Change – that do not require subject specialisation.
General Science
Syllabus for CSAT Paper (Prelims Paper-II)
Comprehension
Interpersonal skills including communication skills
Logical reasoning and analytical ability
Decision-making and problem solving
General mental ability
Basic numeracy (numbers and their relations, orders of magnitude, etc.) (Class X level), Data interpretation (charts, graphs, tables, data sufficiency etc. – Class X level)
Note I : Answer all questions in this paper will have to be attempted in English only.
Paper IV: Essay ( 200 Marks/ 3 hours duration)
Candidates will be required to write two Essays. One topic will pertain to Indian Society/
politics/ Economy/Development, Growth, and related aspects. The other topic will pertain
to security and related matters. Candidates will be expected to keep close to the
subject of the essay to arrange their ideas in an orderly fashion and to write concisely.
Credit will be given for effective and exact expression.
Paper V: General Studies (200 Marks/ 3 hours duration)
The questions will be such as to test a candidate’s awareness of a variety of subjects
and are likely to test the candidate’s basic understanding of all relevant issues, and
the ability to analyze and take a view on conflicting socio-economic goals, objectives and
demands. The candidates must give relevant, meaningful and succinct answers.
Note: This paper can be answered by the Candidates either in English or in Hindi.
Attempting answers in any other language or use of ‘mixed’ language (i.e. partly in English and partly in Hindi) is not permissible.
Syllabus:
a) A brief idea about the History and Geography of India.
b) Constitution of India and Indian Polity: This part will include questions on the Constitution of India, as well as all constitutional, legal, administrative and other issues emerging from the politico-administrative system prevalent in the country.
c) Current National Issues and Topics of Social Relevance -
This part is intended to test the Candidate’s awareness of current national issues and topics of social relevance in present-day India, such as the following :


Eskaton

Eskaton is a defunct vanity record label created by Coil, exclusively for albums put out by the group and their friends. Its brother labels are Threshold House and Chalice.
The record label is often associated with the symbol of the "Chaos Cross" and the "Twisted Chaos Cross", symbols which have appeared on several Eskaton releases, such as "Gold Is The Metal with the Broadest Shoulders".
Chaos Cross.
The symbol of the chaos cross was used almost exclusively in the times of Coil's side projects. It is a dominant symbol which can be found on a number of releases and merchandise.


4942 Munroe

4942 Munroe, provisional designation , is an asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 24 February 1987, by Belgian astronomer Henri Debehogne at ESO's La Silla Observatory in northern Chile, and later named after American cartoonist and former NASA roboticist Randall Munroe.
Orbit and classification.
"Munroe" orbits the Sun in the inner main-belt at a distance of 1.9–2.5 AU once every 3 years and 3 months (1,193 days). Its orbit has an eccentricity of 0.14 and an inclination of 4° with respect to the ecliptic.
It was first identified as at the Leiden Southern Station (Johannesburg-Hartbeespoort) in 1955, extending the body's observation arc by 32 years prior to its official discovery observation.
Physical characteristics.
In the SMASS taxonomy, "Munroe" is characterized as an X-type asteroid. It has an absolute magnitude of 13.5.
Diameter and albedo.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, "Munroe" measures 3.453 kilometers in diameter and its surface has an exceptionally high albedo of 0.936. On his private blog, Randall Munroe (after whom the asteroid is named) calculates that the asteroid is between 6 and 10 kilometers in diameter, comparable in size to the Chicxulub asteroid.
Lightcurves.
As of 2017, "Munroe"s rotation period, poles and shape remain unknown.
Naming.
In 2013, it was named after Randall Munroe (born 1984), a former NASA roboticist and the author of the webcomic "xkcd". The name was chosen by "xkcd" readers Lewis Hulbert and Jordan Zhu. The official naming citation was published on 22 July 2013 ().


Troubleman Unlimited Records

Troubleman Unlimited Records was a record label specializing in indie rock and similar genres. Founded in 1993, the label was based in Bayonne, New Jersey and owned by Mike Simonetti.
History.
The label started as an offshoot of a fanzine called "Wanna Communicate?", releasing 7" singles. The label grew significantly in the 2000s, releasing full-length albums by many groups who are regularly reviewed in media outlets like "Spin" and Pitchfork. The label focused on noise rock, including releases from Black Dice, Wolf Eyes and Hair Police. Troubleman Unlimited was named "Best Label" by "New York Magazine" in 2005.
In the 21st century, Simonetti started a dance label, Italians Do It Better, with Johnny Jewel of Glass Candy.
Band roster.
The following artists have made at least one release through Troubleman Unlimited or Italians Do It Better.


Vibrating-sample magnetometer

A vibrating-sample magnetometer (VSM) (also referred to as a Foner magnetometer) is a scientific instrument that measures magnetic properties based on Faraday’s Law of Induction. Simon Foner at MIT Lincoln Laboratory invented VSM in 1955 and reported it in 1959. Also it was mentioned by G.W. Van Oosterhout and by P.J Flanders in 1956. A sample is first placed in a constant magnetic field and if the sample is magnetic it will align its magnetization with the external field. The magnetic dipole moment of the sample creates a magnetic field that changes as a function of time as the sample is moved up and down. This is typically done through the use of a piezoelectric material. The alternating magnetic field induces an electric field in the pickup coils of the VSM. The current is proportional to the magnetization of the sample - the greater the induced current, the greater the magnetization. As a result, typically a hysteresis curve will be recorded and from there we can deduce the magnetic properties of the sample being measured.
The idea of vibrating sample came from D. O. Smith's vibrating-coil magnetometer.
Typical VSM overview:.
Conditions for VSM to be effective:.
Importance of pick-up coils:.
These allow the VSM to maximize the induced signal, reduce the noise, give a wide saddle point, minimize the volume in between the sample and electromagnet to achieve a more uniform magnetic field at the sample space. The configuration of the coils can vary depending on the type of material being studied.
Relation to Physics:.
The VSM relies on Faraday's law of induction, with the detection of the emf given by formula_1, where "N" is the number of wire turns, "A" is the area, and formula_2 the angle between the normal of the coil and the B field. However, "N" and "A" are often unnecessary if the VSM is properly calibrated. By varying the strength of the electromagnet through computer software, the external field is sweeped from high to low and back to high. Typically this is automated through a computer process and a cycle of data is printed out. The electromagnet is typically attached to a rotating base so as to allow the measurements be taken as a function of angle. The external field is applied parallel to the sample length and the aforementioned cycle prints out a hysteresis loop. Then using known magnetization of the calibration material and wire volume the high field voltage signal can be converted into emu units - useful for analysis.
Advantages and Disadvantages:.
The precision and accuracy of VSM's are quite high even among other magnetometers and can be on the order of ~ formula_3 emu. VSM's further allow for a sample to be tested at varying angles with respect to it's magnetization letting researches minimize the effects of external influences. However, VSM's are not well suited for determining the magnetization loop due to the demagnetizing effects incurred by the sample. VSM's further suffer from temperature dependence and cannot be used on fragile samples that cannot undergo acceleration (from the vibration).


Type 98 Chi-Ho medium tank

The experimental Type 98 "Chi-Ho" was a prototype Japanese medium tank. It was developed on orders from the Imperial Japanese Army. "Chi Ho" indicates that it is designated as the 5th (I, Ro, Ha, Ni, Ho) medium (Chi) tank. A total of four prototypes were completed. Two were built in 1940 and two were built in 1941. It did not enter production.
History and development.
In the late 1930s, the Imperial Japanese Army was in search for a successor to the Type 89 Medium Tank. The experimental Type 97 Chi-Ni medium tank was considered as meeting the requirement of a "light and low-cost tank which can be deployed in large numbers"; while the Chi-Ha (later the Type 97 Chi-Ha) was thought as the more effective fighting vehicle for the needs of the military. With the outbreak of the Sino-Japanese war on 7 July 1937, the peacetime budgetary limitations were removed and the more capable and expensive Mitsubishi Chi-Ha model was accepted as the new Type 97 medium tank by the army.
However, the army chief staff did not give up on the idea of a lower-cost and lighter weight medium tank and thus this vehicle was developed. A total of four prototypes were built.
Design.
Armament.
Heavy emphasis was placed on a gun with a high penetration and the high velocity 47mm tank cannon was selected. Both the Chi-Ni and the Chi-Ha were equipped with a Type 97 57 mm main gun. The cannon was a short-barreled weapon with a relatively low muzzle velocity, but sufficient as the tank was intended primarily for infantry support.
The shortcomings of the Type 97 Chi-Ha, with its low-velocity 57 mm gun, became clear during the 1939 Battles of Khalkhin Gol against the Soviet Union. The 45 mm gun of the Soviet BT-5 and BT-7 tanks out-ranged the Japanese tank gun, resulting in heavy Japanese losses. This convinced the army of the need for a more powerful gun. The following change order looked closely at the next medium tank shortly before this vehicle was completed. In the change order sent to the tank research committee, Showa 14 were design conditions "for the next tank`s turret, even if taking the 57mm cannon into account, further research will be made into firepower. The caliber, if by no choice, will be no smaller than 47mm. The likelihood of being pressed into tank battles in future wars is something that should be considered." This tank's experimental 47mm tank cannon was derived from the research results of the "Experimental type 97 47mm cannon" and the "experimental 47mm cannon". From June 1940, a completed cannon of the experimental 47mm cannon begun various testing and in September, the experimental 47mm tank cannon was mounted on a Type 98 Chi-Ho turret. The turret was then mounted on a Type 97 Chi-Ha's hull and underwent testing. The Type 1 47 mm tank gun was designed specifically to counter the Soviet tanks.
The intention behind the machine gun being mounted in the forward left side of the turret is not clearly known, but it may be akin to a coaxial machine gun. A coaxial machine gun is placed alongside the main armament on the same axle. With that setup, when using the main cannon, the machine can could help predict where the main cannon's fire would land or suppress the enemy while loading the main armament. The machine gun mounted in the Type 98 turret was not a belt-fed type, but rather the Type 97 tank-mounted heavy machine gun, which used 20-round magazines. This presented a limitation in sustaining continuous firing attacks.
Mobility and testing.
The engine mounted in the tank was a Mitsubishi 120 HP diesel engine. Also, it was the first Japanese made tank to use a hydraulic system in the steering system.
Up until then, some advances over the Chi-Ha variants can be seen, but some aspects in the tank hull were still lagging behind. A sled was attached to the rear part of the hull. This is commonly seen on World War I and inter-war tanks. It was thought that by extending the length of the hull, it gained the benefit of crossing trenches, but in that, there was a problem. As a tank mounts a sled, it becomes tail heavy (center of weight shifts backwards) and that presented uncertainty when crossing wide trenches. By becoming tail heavy, the rear portion of the suspension would undertake a greater load and thus wear out faster. Furthermore, the somewhat increase in weight would reduce mobility. With the applied limitations on the tank's weight, it is not believed that the armor protection level could have been improved. Without a cupola, the ability to observe outside would have been worse than the Chi-Ha.
Mitsubishi and Jidosha Kogyo completed the first two prototypes in 1940 and the Kokura and Sagami Arsenals produced two more by the following year. After field tests, the tank was not selected for production. The Imperial Japanese Army realized that further research was needed and a better design made to counter the 1940s generation of Allied armor, such as the M4 Sherman. A new tank design based on an improved Type 97 design was conceived. The first of this new series was the Type 1 Chi-He medium tank. Work on that design began in 1941. However, production of the Type 1 Chi-He did not begin until 1943, due to the higher priority of steel allocated to the Imperial Navy for warship construction.


Amphetamine Reptile Records

Amphetamine Reptile Records (or AmRep Industries) is a record label which was founded in 1986 by Tom Hazelmyer in Washington state. The label specializes in noise rock and also released "Strap It On", the debut album by alternative metal band Helmet which sold more than 40,000 records. According to Hazelmyer, the success of the album was vital to keeping AmRep going throughout the 1990s, as it "helped support the other things that sold less." The label was the subject of the 2014 documentary "The Color of Noise".
History.
Hazelmyer originally started the label to release records by his band, Halo of Flies. Eventually the label's roster expanded to include releases by Helmet, the Melvins, the Cows, Helios Creed, Chokebore, Servotron and others. Hazelmyer later moved the label to Minneapolis. Today the label is used by the Melvins, H•O•F and other legacy AmRep acts on to release limited edition vinyl. These releases are generally noted for their Linocut artwork, hand carved by Hazelmyer, their limited availability and their highly sought after nature as collector's items.
Much of the AmRep back catalog is now out of print, although many of the releases are available in digital download format and streaming.
On May 13, 2020 Tom Hazelmyer participated in an in-depth interview about the label on Conan Neutron's Protonic Reversal.


689 Zita

689 Zita is a minor planet orbiting the Sun. It was named after Zita of Bourbon-Parma, the last empress of Austria-Hungary.


Greater undecimal neutral second


6077 Messner


Septimal meantone temperament

In music, septimal meantone temperament, also called "standard septimal meantone" or simply "septimal meantone", refers to the tempering of 7-limit musical intervals by a meantone temperament tuning in the range from fifths flattened by the amount of fifths for 12 equal temperament to those as flat as 19 equal temperament, with 31 equal temperament being a more or less optimal tuning for both the 5- and 7-limits. Meantone temperament represents a frequency ratio of approximately 5 by means of four fifths, so that the major third, for instance C-E, is obtained from two tones in succession. Septimal meantone represents the frequency ratio of 56 (7*23) by ten fifths, so that the interval 7:4 is reached by five successive tones. Hence C-A, not C-B, represents a 7:4 interval in septimal meantone.
The meantone tuning with pure 5:4 intervals (quarter-comma meantone) has a fifth of size 696.58 cents . Similarly, the tuning with pure 7:4 intervals has a fifth of size 696.88 cents . 31 equal temperament has a fifth of size 696.77 cents , which does excellently for both of them, having the harmonic seventh only 1.1 cent lower, and the major third 1.2 cent higher than pure (while the fifth is 5.2 cent lower than pure). However, the difference is so small that it is mainly academic.
Theoretical properties.
Septimal meantone tempers out not only the syntonic comma of 81:80, but also the septimal semicomma of 126:125, and the septimal kleisma of 225:224. Because the septimal semicomma is tempered out, a chord with intervals 6:5-6:5-6:5-7:6, spanning the octave, is a part of the septimal meantone tuning system. This chord might be called the "septimal semicomma diminished seventh". Similarly, because the septimal kleisma is tempered out, a chord with intervals of size 5:4-5:4-9:7 spans the octave; this might be called the "septimal kleisma augmented triad", and is likewise a characteristic feature of septimal meantone.
Chords of septimal meantone.
Septimal meantone of course has major and minor triads, and also diminished triads, which come in both an otonal, 5:6:7 form, as for instance C-E-F, and an inverted utonal form, as for instance C-D-F. As previously remarked, it has a septimal diminished seventh chord, which in various inversions can be C-E-G-B, C-E-G-A, C-E-F-A or C-D-F-A. It also has a septimal augmented triad, which in various inversions can be C-E-G, C-E-A or C-F-A. It has both a dominant seventh chord, C-E-G-B, and an otonal tetrad, C-E-G-A; the latter is familiar in common practice harmony under the name German sixth. It likewise has utonal tetrads, C-E-G-B, which in
the arrangement B-E-G-C becomes Wagner's Tristan chord. It has also the subminor triad, C-D-G, which is otonal, and the supermajor triad, C-F-G, which is utonal. These can be extended to subminor tetrads, C-D-G-A and supermajor tetrads C-F-G-B.
11-limit meantone.
Septimal meantone can be extended to the 11-limit, but not uniquely. It is possible to take the interval of 11 by means of 18 fifths up and 7 octaves down, so that an 11:4 is made up of nine tones (e.g. C-E). The 11 is pure using this method if the fifth is of size 697.30 cents, very close to the fifth of 74 equal temperament. On the other hand, 13 meantone fourths up and two octaves down (e.g. C-G) will also work, and the 11 is pure using this method for a fifth of size 696.05 cents, close to the 696 cents of 50 equal temperament. The two methods are conflated for 31 equal temperament, where E and G are enharmonic.


340 Eduarda

Eduarda (minor planet designation: 340 Eduarda) is a main belt asteroid that was discovered by German astronomer Max Wolf on 25 September 1892 in Heidelberg. It was named after German banker and amateur astronomer Heinrich Eduard von Lade.
Photometric observations of this asteroid at the Oakley Observatory in Terre Haute, Indiana, during 2006 gave a light curve with a period of 8.04 ± 0.02 hours and a brightness variation of 0.25 ± 0.03 in magnitude.


Location testing for Gaussian scale mixture distributions

In statistics, the topic of location testing for Gaussian scale mixture distributions arises in some particular types of situations where the more standard Student's t-test is inapplicable. Specifically, these cases allow tests of location to be made where the assumption that sample observations arise from populations having a normal distribution can be replaced by the assumption that they arise from a Gaussian scale mixture distribution. The class of Gaussian scale mixture distributions contains all symmetric stable distributions, Laplace distributions, logistic distributions, and exponential power distributions, etc.
Introduce
the counterpart of Student's t-distribution for Gaussian scale mixtures. This means that if we test the null hypothesis that the center of a Gaussian scale mixture distribution is 0, say, then "t""n""G"("x") ("x" ≥ 0) is the infimum of all monotone nondecreasing functions "u"("x") ≥ 1/2, "x" ≥ 0 such that if the critical values of the test are "u"−1(1 − "α"), then the significance level is at most "α" ≥ 1/2 for all Gaussian scale mixture distributions ["t""G""n"(x) = 1 − "t""G""n"(−"x"),for "x" < 0]. An explicit formula for "t""G""n"("x"), is given in the papers in the references in terms of Student’s t-distributions, "t""k", "k" = 1, 2, …, "n". Introduce
the Gaussian scale mixture counterpart of the standard normal cumulative distribution function, Φ(x).
Theorem. Φ"G"("x") = 1/2 for 0 ≤ "x" < 1, Φ"G"(1) = 3/4, Φ"G"("x") = "C"("x"/(2 − "x"2)1/2) for quantiles between 1/2 and 0.875, where "C"("x") is the standard Cauchy cumulative distribution function. This is the convex part of the curve Φ"G"("x"), "x" ≥ 0 which is followed by a linear section Φ"G"("x") = "x"/(2) + 1/2 for 1.3136… < "x" < 1.4282... Thus the 90% quantile is exactly 4/5. Most importantly,
Note that Φ() = 0.958…, thus the classical 95% confidence interval for the unknown expected value of Gaussian distributions covers the center of symmetry with at least 95% probability for Gaussian scale mixture distributions. On the other hand, the 90% quantile of ΦG("x") is 4/5 = 1.385… > Φ−1(0.9) = 1.282… The following critical values are important in applications: 0.95 = Φ(1.645) = ΦG(1.651), and 0.9 = Φ(1.282) = ΦG(1.386).
For the extension of the Theorem to all symmetric unimodal distributions one can start with a classical result of Aleksandr Khinchin: namely that all symmetric unimodal distributions are scale mixtures of symmetric uniform
distributions.
Open problem.
The counterpart of the Theorem above for the class of all symmetric distributions, or equivalently, for the class of scale mixtures of coin flipping random variables, leads to the following problem:


B tuning

B Tuning or B Standard Tuning is the standard tuning for a seven string guitar, where the strings are tuned B-E-A-D-G-B-E. B tuning can also be achieved on a six-string guitar, when the strings are tuned B-E-A-D-F♯-B, known then as Baritone Tuning. This tuning is popular among several different types of metal bands.
The following is a list of musical groups who use this tuning on six-string or seven-string guitars:


Calipers

A caliper (British spelling also calliper, or in plurale tantum sense a pair of calipers) is a device used to measure the dimensions of an object.
Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display. Some calipers can be as simple as a compass with inward or outward-facing points, but no scale. The tips of the caliper are adjusted to fit across the points to be measured and the dimension read by measuring between the tips with another measuring tool, such as a ruler.
It is used in many fields such as mechanical engineering, metalworking, forestry, woodworking, science and medicine.
Plural vs. singular.
A single tool might be referred to as a "caliper" or as "calipers", like a pair of scissors or glasses (a "plural only" or "plurale tantum" form). In colloquial usage, the phrase "pair of verniers" or just "vernier" might refer to a vernier caliper. Colloquially these phrases can also refer to dial calipers, although they involve no vernier scale.
In machine-shop usage, the term "caliper" is often used in contradistinction to "micrometer", even though outside micrometers are technically a form of the caliper. In this usage, "caliper" implies only the form factor of the vernier or dial caliper (or its digital counterpart).
History.
The earliest caliper has been found in the Greek Giglio wreck near the Italian coast. The ship's find dates to the 6th century BC. The wooden piece already featured a fixed and a movable jaw. Although rare finds, calipers remained in use by the Greeks and Romans.
A bronze caliper, dating from 9 AD, was used for minute measurements during the Chinese Xin dynasty. The caliper had an inscription stating that it was "made on the "gui-you" day, the first day of the first month of the first year of "Shijianguo" ." The calipers included a "slot and pin" and "graduated in inches and tenths of an inch."
The modern vernier caliper was invented by Pierre Vernier, as an improvement of the nonius of Pedro Nunes.
Types.
Inside caliper.
The inside calipers are used to measure the internal size of an object.
Outside caliper.
Outside calipers are used to measure the external size of an object.
The same observations and technique apply to this type of caliper, as for the above inside caliper. With some understanding of their limitations and usage, these instruments can provide a high degree of accuracy and repeatability. They are especially useful when measuring over very large distances; consider if the calipers are used to measure a large diameter pipe. A vernier caliper does not have the depth capacity to straddle this large diameter while at the same time reach the outermost points of the pipe's diameter. They are made from high carbon steel.
Divider caliper.
In the metalworking field, a divider caliper, popularly called a compass, is used in the process of marking out locations. The points are sharpened so that they act as scribers; one leg can then be placed in the dimple created by a center or prick punch and the other leg pivoted so that it scribes a line on the workpiece's surface, thus forming an arc or circle.
A divider caliper is also used to measure a distance between two points on a map. The two caliper's ends are brought to the two points whose distance is being measured. The caliper's opening is then either measured on a separate ruler and then converted to the actual distance, or it is measured directly on a scale drawn on the map. On a nautical chart the distance is often measured on the latitude scale appearing on the sides of the map: one minute of arc of along any great circle, as for example, any longitude meridian, is approximately one nautical mile or 1852 meters.
Dividers are also used in the medical profession. An ECG (also EKG) caliper transfers distance on an electrocardiogram; in conjunction with the appropriate scale, the heart rate can be determined. A pocket caliper version was invented by cardiologist Robert A. Mackin.
Oddleg caliper.
Oddleg calipers, Hermaphrodite calipers, or Oddleg Jennys, as pictured on the left, are generally used to scribe a line at a set distance from the edge of a workpiece. The bent leg is used to run along the workpiece edge while the scriber makes its mark at a predetermined distance, this ensures a line parallel to the edge.
In the diagram at left, the uppermost caliper has a slight shoulder in the bent leg allowing it to sit on the edge more securely, the lower caliper lacks this feature but has a renewable scriber that can be adjusted for wear, as well as being replaced when excessively worn.
Vernier caliper.
The vernier, dial, and digital calipers give a direct reading of the distance measured with high accuracy and precision. They are functionally identical, with different ways of reading the result. These calipers comprise a calibrated scale with a fixed jaw, and another jaw, with a pointer, that slides along the scale. The distance between the jaws is then read in different ways for the three types.
The simplest method is to read the position of the pointer directly on the scale. When the pointer is between two markings, the user can mentally interpolate to improve the precision of the reading. This would be a simply calibrated caliper, but the addition of a vernier scale allows more accurate interpolation and is the universal practice; this is the vernier caliper.
Vernier, dial, and digital calipers can measure internal dimensions (using the uppermost jaws in the picture at right), external dimensions using the pictured lower jaws, and in many cases depth by the use of a probe that is attached to the movable head and slides along the center of the body. This probe is slender and can get into deep grooves that may prove difficult for other measuring tools.
The vernier scales may include metric measurements on the lower part of the scale and inch measurements on the upper, or vice versa, in countries that use inches. Vernier calipers commonly used in industry provide a precision to 0.01 mm (10 micrometres), or one thousandth of an inch. They are available in sizes that can measure up to 1828 mm (72 in).
Dial caliper.
Instead of using a vernier mechanism, which requires some practice to use, the dial caliper reads the final fraction of a millimeter or inch on a simple dial.
In this instrument, a small, precise rack and pinion drives a pointer on a circular dial, allowing direct reading without the need to read a vernier scale. Typically, the pointer rotates once every inch, tenth of an inch, or 1 millimeter. This measurement must be added to the coarse whole inches or centimeters read from the slide. The dial is usually arranged to be rotatable beneath the pointer, allowing for "differential" measurements (the measuring of the difference in size between two objects, or the setting of the dial using a master object and subsequently being able to read directly the plus-or-minus variance in the size of subsequent objects relative to the master object).
The slide of a dial caliper can usually be locked at a setting using a small lever or screw; this allows simple go/no-go checks of part sizes.
Digital caliper.
A popular refinement replaces the analog dial with an electronic digital display that displays the reading as a numeric value. Rather than a rack and pinion, these calipers use a linear encoder. Some digital calipers can be switched between centimeters or millimeters, and inches. All provide for zeroing the display at any point along with the slide, allowing the same sort of differential measurements as with the dial caliper. Digital calipers may contain a "reading hold" feature, allowing the reading of dimensions after use in awkward locations where the display cannot be seen.
Ordinary 6-in/150-mm digital calipers are made of stainless steel, have a rated accuracy of 0.001 in (0.02mm) and a resolution of 0.0005 in (0.01 mm).
The same technology is used to make longer 8-in and 12-in calipers; the accuracy for longer measurements declines to 0.001 in (0.03 mm) for 100–200 mm and 0.0015 in (0.04 mm) for 200–300 mm.
Increasingly, digital calipers offer a serial data output to allow them to be interfaced with a dedicated recorder or a personal computer. The digital interface significantly decreases the time to make and record a series of measurements, and it also improves the reliability of the records. A suitable device to convert the serial data output to common computer interfaces such as RS-232, Universal Serial Bus, or wireless can be built or purchased. With such a converter, measurements can be directly entered into a spreadsheet, a statistical process control program, or similar software.
The serial digital output varies among manufacturers. Common options are
Like dial calipers, the slide of a digital caliper can usually be locked using a lever or thumb-screw.
Some digital calipers contain a capacitive linear encoder. A pattern of bars is etched directly on the printed circuit board in the slider. Under the scale of the caliper another printed circuit board also contains an etched pattern of lines. The combination of these printed circuit boards forms two variable capacitors. The two capacitances are out of phase. As the slider moves the capacitance changes in a linear fashion and in a repeating pattern. The circuitry built into the slider counts the bars as the slider moves and does a linear interpolation based on the magnitudes of the capacitors to find the precise position of the slider. Other digital calipers contain an inductive linear encoder, which allows robust performance in the presence of contamination such as coolants. Magnetic linear encoders are used in yet other digital calipers.
Micrometer caliper.
A caliper using a calibrated screw for measurement, rather than a slide, is called an "external micrometer caliper gauge", a "micrometer caliper" or, more often, simply a "micrometer". (Sometimes the term "caliper", referring to any other type in this article, is held in contradistinction to "micrometer".)
Comparison.
Each of the above types of calipers has its relative merits and faults.
Vernier calipers are rugged and have long-lasting accuracy, are coolant proof, are not affected by magnetic fields, and are largely shockproof. They may have both centimeter and inch scales. However, vernier calipers require good eyesight or a magnifying glass to read and can be difficult to read from a distance or from awkward angles. It is relatively easy to misread the last digit. In production environments, reading vernier calipers all day long is error-prone and is annoying to the workers. however digital vernier calipers have greater precision than mechanical vernier calipers because the least count of digital vernier calipers is 0.01 mm
Dial calipers are comparatively easy to read, especially when seeking the exact center by rocking and observing the needle movement. They can be set to 0 at any point for comparisons. They are usually fairly susceptible to shock damage. They are also very prone to getting dirt in the gears, which can cause accuracy problems.
Digital calipers switch easily between the centimeter and inch systems. They can be set to 0 easily at any point with a full count in either direction and can take measurements even if the display is completely hidden, either by using a "hold" key, or by zeroing the display and closing the jaws, showing the correct measurement, but negative. They can be mechanically and electronically fragile. Most also require batteries and do not resist coolant well. They are also only moderately shockproof and can be vulnerable to dirt.
Calipers may read to a resolution of 0.01 mm or 0.0005 in, but accuracy may not be better than about ±0.02 mm or 0.001 in for 150 mm (6 in) calipers, and worse for longer ones.
Use.
A caliper must be properly applied against the part in order to take the desired measurement. For example, when measuring the thickness of a plate a vernier caliper must be held at right angles to the piece. Some practice may be needed to measure round or irregular objects correctly.
Accuracy of measurement when using a caliper is highly dependent on the skill of the operator. Regardless of type, a caliper's jaws must be forced into contact with the part being measured. As both part and caliper are always to some extent elastic, the amount of force used affects the indication. A consistent, firm touch is correct. Too much force results in an under indication as part and tool distort; too little force gives insufficient contact and an over indication. This is a greater problem with a caliper incorporating a wheel, which lends mechanical advantage. This is especially the case with digital calipers, calipers out of adjustment, or calipers with a poor quality beam.
Simple calipers are uncalibrated; the measurement taken must be compared against a scale. Whether the scale is part of the caliper or not, all-analog calipers—verniers and dials—require good eyesight in order to achieve the highest precision. Digital calipers have an advantage in this area.
Calibrated calipers may be mishandled, leading to loss of zero. When a calipers' jaws are fully closed, it should, of course, indicate zero. If it does not, it must be recalibrated or repaired. A vernier caliper does not easily lose its calibration but a sharp impact or accidental damage to the measuring surface in the caliper jaw can be significant enough to displace zero. Digital calipers have zero set buttons, for quick recalibration.
Vernier, dial, and digital calipers can be used with accessories that extend their usefulness. Examples are a base that extends its usefulness as a depth gauge and a jaw attachment that allows measuring the center distance between holes. Since the 1970s a clever modification of the moveable jaw on the backside of any caliper allows for step or depth measurements in addition to external caliper measurements, in a similar fashion to a universal micrometer (e.g., Starrett Mul-T-Anvil or Mitutoyo Uni-Mike).
Zero error.
The method to use a vernier scale or caliper with zero error is to use the formula "actual reading = main scale + vernier scale − (zero error)". Zero error may arise due to knocks that affect the calibration at 0.00  mm when the jaws are perfectly closed or just touching each other. Positive zero error refers to the fact that when the jaws of the vernier caliper are just closed, the reading is a positive reading away from the actual reading of 0.00  mm. If the reading is 0.10 mm, the zero error is referred to as +0.10 mm. Negative zero error refers to the fact that when the jaws of the vernier caliper are just closed, the reading is a negative reading away from the actual reading of 0.00  mm. If the reading is −0.08  mm, the zero error is referred to as −0.08  mm.


Thomas Edwin Nevin

Thomas Edwin Nevin (4 October 1906 in Bristol, Somerset – 16 July 1986 in Dublin) was an Irish physicist and academic who had a distinguished career in the field of molecular spectroscopy. He was Professor of Experimental Physics and Dean of the Faculty of Science in University College Dublin (UCD) from 1963 to 1979.
Education and career.
Born in 1906 in Bristol, England, the oldest of seven children of an Irish father and English mother, the family soon settled in Ireland where he spent his youth. From 1919 to 1924 he attended the CBS Sexton Street secondary school in Limerick City. The school had no science program, but Nevin was interested in physics and managed to learn the subject pretty thoroughly on his own. In 1924 he got a scholarship to University College Dublin (UCD). While there he excelled in mathematics and physics, winning first-class honours every year, and earning an honours B.Sc. in Experimental Physics and Mathematics in 1927. He got his M.Sc. under JJ Nolan in 1928 for a treatise on "The Effect of Water Vapour on the Diffusion Coefficients and Mobilities of Ions in the Air". That year he was also awarded an 1851 Research Fellowship (a legacy of The Great Exhibition of 1851), and this enabled him to study spectroscopy at Imperial College, London (1929–1931). In 1931 he returned to UCD to continue his research and was appointed assistant in the department of experimental physics.
In 1940, he was awarded a D.Sc. degree at National University of Ireland (NUI) for previously published work, and in 1942, he was awarded an honorary doctorate at Queen's University Belfast. Throughout the 1930s and 1940s he continued his research in molecular spectroscopy, often working with research groups in fundamental particle and cosmic ray physics. He was a capable administrator at UCD, serving on the university's finance and buildings committees, as well as the academic council and governing body, and he initiated many improvements to the physics department. When J. J. Nolan died in 1952, Nevin succeeded him as Professor of Experimental Physics, a position he held until his retirement in 1979.
Nevin was a strong advocate for expansion of the UCD campus, which for half a century was based at Earlsfort Terrace in the city. As a key member of UCD's academic council and a member of its buildings committee (1957–76), he was instrumental in moving the science faculty to the new Belfield campus in the southern suburbs in 1964.
He was a key figure in the formation of the Irish branch of Institute of Physics in Ireland.
At the Dublin Institute for Advanced Studies (DIAS) he was a member of the governing boards of the school of theoretical physics (1943-1961) and the school of cosmic physics (1948-1956).
On 16 March 1942 he was elected a member of the Royal Irish Academy (RIA) and served on its council from 1944 to 1968.
Personal life.
Thomas E. Nevin was born in Bristol, Somerset on 4 October 1906. He was the eldest of seven children born to Thomas Nevin of Cashel, County Tipperary, and Alice Nevin (née Higginson) of Herefordshire. Áine Ní Chnáimhín (1908–2001) who wrote a biography of Pádraic Ó Conaire was Nevin's sister; historian and trade unionist Donal Nevin was his brother.
In January 1936 he married Monica T. M. Morrissey, a UCD graduate in Celtic studies who went on to serve on the Council of the Royal Society of Antiquaries of Ireland and did research on antiquarian matters for "Irish History Online". The Nevins had four children, all girls.
Thomas E. Nevin Medal.
Each year at UCD, the Thomas E. Nevin Medal and Prize is given to the graduate who obtains First Class Honours and first place in the BSc Honours Degree Examination in Physics.


California Subject Examinations for Teachers

The California Subject Examinations for Teachers, also abbreviated as CSET, is a group of subject matter tests used in California and other states to assess mastery of subject matter content by prospective K-12 teachers. Appropriate subtests of the CSET must be passed before a candidate begins a state-approved teacher preparation program, and satisfies the No Child Left Behind (P.L. 107-110) "highly qualified teacher" requirement.
The tests are administered by National Evaluation Systems, a division of Pearson Education, Inc. Most include both multiple choice and constructed response sections.
The CSET Multiple Subjects Exam is taken by candidates for the multiple subject (elementary education) and Education Specialist (special education) teaching credential. It consists of three subtests. Subtest I covers reading, language, literature, and history; Subtest II covers math and science; Subtest III covers visual and performing arts, physical education, and human development. Subtests may be taken separately or all at once; candidates pay for each subtest separately.
CSET Single Subject Exams are used to assess mastery of specific matter by candidates for the single-subject (secondary) teaching credential. The examination is taken by subject area, such as English or mathematics, and individual tests vary from two to four subtests.


Salisbury Plain

Salisbury Plain is a chalk plateau in the south western part of central southern England covering . It is part of a system of chalk downlands throughout eastern and southern England formed by the rocks of the Chalk Group and largely lies within the county of Wiltshire, but stretches into Berkshire, Hampshire and a small part of Somerset.
The plain is famous for its rich archaeology, including Stonehenge, one of England's best known landmarks. Large areas are given over to military training and thus the sparsely populated plain is the biggest remaining area of calcareous grassland in northwest Europe. Additionally the plain has arable land, and a few small areas of beech trees and coniferous woodland. Its highest point is Easton Hill.
Physical geography.
The boundaries of Salisbury Plain have never been truly defined, and there is some difference of opinion as to its exact area. The river valleys surrounding it, and other downs and plains beyond them loosely define its boundaries. To the north the scarp of the downs overlooks the Vale of Pewsey, and to the northwest the Bristol Avon. The River Wylye runs along the southwest, and the Bourne runs to the east. The Hampshire Avon runs through the eastern half of the plain, and to the south the plain peters out as the river valleys close together before meeting at Salisbury. From here the Avon continues south to the English Channel at Christchurch. The Hampshire Downs and the Berkshire Downs are chalk downland to the east and north of Salisbury Plain, and the Dorset Downs and Cranborne Chase are to the southwest. In the west and north west the geology is mainly the clays and limestones of the Blackmore Vale, Avon Vale and Vale of Wardour. The Mendip Hills rise to the west of Salisbury Plain, and the Cotswolds to the north west.
Amesbury is considered the largest settlement on the plain, though there are a number of small villages, such as Tilshead, Chitterne and Shrewton in the middle of the plain, as well as various hamlets and army camps. The A303 road runs through the southern area of the plain, while the A345 and the A360 cut across the centre.
History.
Salisbury Plain is famous for its history and archaeology. In the Neolithic period, Stone Age people began to settle on the plain, most likely centred around the causewayed enclosure of Robin Hood's Ball. Large long barrows such as White Barrow and other earthworks were built across the plain. By 2500 BC areas around Durrington Walls and Stonehenge had become a focus for building, and the southern part of the plain continued to be settled into the Bronze Age.
Around 600 BC, Iron Age hillforts came to be constructed around the boundaries of the plain, including Scratchbury Camp and Battlesbury Camp to the southwest, Bratton Camp to the northwest, Casterley Camp to the north, Yarnbury and Vespasian's Camp to the south, and Sidbury Hill to the east.
Roman roads are visible features, probably serving a settlement near Old Sarum. Villas are sparse, however, and Anglo-Saxon place names suggest that the plain was mostly a grain-producing imperial estate.
In the 6th century, Anglo-Saxon incomers built planned settlements in the valleys surrounded by strip lynchets, with the downland left as sheep pasture. To the south is the city of Salisbury, whose 13th and 14th century cathedral is famous for having the tallest spire in the country, and the building was, for many centuries, the tallest building in Britain. The cathedral is evidence of the prosperity the wool and cloth trade brought to the area. In the mid-19th century the wool and cloth industry began to decline, leading to a decline in the population and change in land use from sheep farming to agriculture and military use. Wiltshire became one of the poorest counties in England during this period of decline.
There are a number of chalk carvings on the plain, of which the most famous is the Westbury White Horse. The Kennet and Avon Canal was constructed to the north of the plain, through the Vale of Pewsey.
In September 1896, George Kemp and Guglielmo Marconi experimented with wireless telegraphy on Salisbury Plain, and achieved good results over a distance of .
Military use.
The military training area covers roughly half of the plain. The army first conducted exercises on the plain in 1898. From that time, the Ministry of Defence bought up large areas of land until the Second World War. The MoD now own of land, making it the largest military training area in the United Kingdom. Much of this land is let to farmers or grazed under licence, while around (12,000 ha) are used for live firing, where public access is greatly restricted or permanently closed. The land and facilities are managed by the MoD's Defence Infrastructure Organisation.
The largest camps and barracks are at Larkhill, Bulford, Tidworth, Trenchard Lines (Upavon) and Waterloo Lines (Warminster). Copehill Down is an urban warfare training site. Several installations have been built and since removed, including a railway line and aerodrome that were constructed next to Stonehenge. A grass aerodrome at Netheravon was used by the RAF until 1963, then by the Army Air Corps until 2012, and now as a tri-service installation.
The Royal School of Artillery has been based at Larkhill since 1915, and live firing is conducted on the plain for approximately 340 days of each year. Military personnel from the UK and around the world spend some 600,000-man days on the plain every year.
In 1943, the village of Imber and the hamlet of Hinton Parva were evacuated to allow training for Operation Overlord to be conducted. Whilst the inhabitants of Hinton Parva were allowed to return at the end of hostilities, Imber village has remained closed, except for an annual church service and some bank holidays. Roads in the Imber area are also closed, as they lie within the Imber Range live firing area; it is possible to walk all of the perimeter of the range on public footpaths.
The training area is close to other military facilities including the Defence Science and Technology Laboratory at Porton Down (much of whose work is secret), Boscombe Down airfield and Middle Wallop Army Air Corps Base in Hampshire, where pilots train on the Westland Apache.
20,000 hectares are designated Sites of Special Scientific Interest and Special Areas of Conservation, and the entire SP is a Special Protection Area for birds.
BFBS Radio broadcasts from studios on Marlborough Road, Bulford, on DAB, FM and satellite channels.
Ecology.
Because of the large training areas inaccessible to the public, the plain is a wildlife haven, and home to two national nature reserves, but there is concern that the low level of grazing on the plain could allow scrub to encroach on the grassland. The plain supports the largest known expanse of unimproved chalk downland in north west Europe, and represents 41% of Britain's remaining area of this wildlife habitat. The plain supports 13 species of nationally rare and scarce plants, 67 species of rare and scarce invertebrates and forms a site of international importance for birds. In addition to chalk downland, the plain supports scrub and woodland habitats, temporary and permanent pools and the River Bourne.
Vegetation.
A diversity of soil types, slope, aspect and past and present land-use has given rise to various grassland communities. Historical evidence suggests that large areas of grassland are of great antiquity, and areas which were cultivated at the beginning of the 20th century have experienced nearly 100 years of chalk grassland re-colonisation. Parts of East Salisbury Plain and the periphery of Central and West comprise areas of grassland currently managed for grazing pasture and hay-cutting, whilst the middle of Centre and West are ungrazed. A large proportion of Salisbury Plain supports upright brome ("Bromus erectus") species-rich grassland, within which a continuous floristic variation is seen. A widespread type on the plain is characterised by an abundance of red fescue ("Festuca rubra"), crested hair-grass ("Koeleria macrantha"), salad burnet ("Sanguisorba minor"), lady's bedstraw ("Galium verum"), rough hawkbit ("Leontodon hispidus"), common rock-rose ("Helianthemum nummularium") and dropwort ("Filipendula vulgaris"). The high constancy of this last species is a distinctive feature of the upright brome grasslands on Salisbury Plain and is otherwise only known from one other site in Hampshire. Where upright brome is less dominating, plants such as small scabiosa ("Scabiosa columbaria"), clustered bellflower ("Campanula glomerata"), dyer's greenweed ("Genista tinctoria"), kidney vetch ("Anthyllis vulneraria"), sainfoin ("Onobrychis viciifolia") and horseshoe vetch ("Hippocrepis comosa") are characteristic associates.
The rare and notable plants which occur here include burnt-tip orchid ("Neotinea ustulata"), slender bedstraw ("Galium pumilum"), field fleawort ("Senecio integrifolius") and the nationally scarce British endemic early gentian ("Gentianella anglica"). Particularly associated with long established turf on thin rendzina soils, and rabbit-grazed areas of the eastern and central ranges, are low-growing perennials including squinancy-wort ("Asperula cynanchica"), chalk milkwort ("Polygala calcarea"), dwarf thistle ("Cirsium acaule"), wild thyme ("Thymus praecox"), the nationally scarce bastard toadflax ("Thesium humifusum") and purple milk-vetch ("Astragalus danicus") in its most southerly British station.
Devil's-bit scabious ("Succisa pratensis"), saw-wort ("Serratula tinctoria") and betony ("Stachys officinalis") are all abundant and exemplify the oceanic character of the chalk grassland on the plain, a feature which is confined to South West England. Similarly restricted is a community in which dwarf sedge "Carex humilis" forms a conspicuous component. This type of grassland has its stronghold in Wiltshire and occurs on the less disturbed areas of the central ranges. Herb diversity is generally lower in the tall, upright brome-dominated swards, but wild parsnip ("Pastinaca sativa"), hogweed ("Heracleum sphondylium") and greater knapweed ("Centaurea scabiosa") are characteristic. Parasitic on the latter species is knapweed broomrape ("Orobanche elatior"), occurring in greater quantity on the plain than anywhere else in Britain. False-oat grass ("Arrhenatherum elatius") grassland is also widespread, but is particularly a feature of the western ranges, often indicating areas of past cultivation.
On anthills, and in the more disturbed turf that is especially a feature of the impact area, mouse-ear hawkweed ("Hieracium pilosella") is abundant together with sheep's fescue ("Festuca ovina") and wild thyme. Annuals are also characteristic of this habitat, including common whitlowgrass ("Erophila verna"), rue-leaved saxifrage ("Saxifraga tridactylites",) hairy rock-cress ("Arabis hirsuta") and the nationally scarce dwarf mouse-ear ("Cerastium pumilum") and fine-leaved sandwort ("Minuartia hybrida"). A very local community characterised by a lichen-rich turf ("Cladonia" species) and the broom moss ("Dicranum scoparium") is found in some stabilised missile-impaction craters on the central ranges. This vegetation type is found elsewhere only on Porton Down SSSI and on the Brecklands.
Small areas of chalk-heath vegetation occur on superficial clay-with-flints deposits. Here chalk-loving plants such as salad burnet ("Sanguisorba minor") and dropwort co-exist with plants typical of acid soils, including gorse ("Ulex europaeus"), heather ("Calluna vulgaris") and the uncommon annual knawel ("Scleranthus annuus"). Two Red Data Book (RDB) plants occur on the plain. The largest population in Britain of tuberous thistle ("Cirsium tuberosum") occurs on the western ranges and is notable for the low incidence of hybridisation with dwarf thistle, a contributory cause of its decline in other localities. Meadow clary ("Salvia pratensis") persists as a small colony in tall upright brome grassland.
Salisbury Plain supports a diverse bryophyte flora with seven nationally scarce species which have seen a general decline in other chalk grassland sites, including "Barbula acuta", "Phascum curvicolle", "Pleurochaete squarrosa", "Thuidium abietinum" and "Weissia sterilis".
Although there is some scrub development on the plain, it is remarkable that large expanses of the chalk grassland remain open with very little invasion of woody species. Of particular interest are the large stands of juniper ("Juniperus communis") on Bulford Downs and Beacon Hill. Both pyramidal and prostrate forms are present and this site, along with Porton Down SSSI to the south, supports the best remaining examples of the lowland type of juniper associated with chalk and mixed scrub in England.
Insects.
The botanically and structurally diverse grasslands support a large range of rare and uncommon chalk downland invertebrates. Where abundance has been assessed strong populations of national and local importance are present, and the large area of habitat available to them is important in ensuring their survival.
Butterflies.
The plain is an important stronghold for declining downland butterflies. A high concentration of colonies of three nationally scarce species, the Adonis blue ("Polyommatus bellargus"), Duke of Burgundy ("Hamearis lucina"), and the largest population of marsh fritillary ("Euphydryas aurinia") on the chalk, occur. A colony of brown hairstreak ("Thecla betulae") is present on East Salisbury Plain at one of its two Wiltshire localities. Strong populations of other downland species such as chalkhill blue ("Polyommatus coridon") and dark green fritillary ("Argynnis aglaja") are found, and of note here is the occurrence of grayling ("Hipparchia semele"), a butterfly rarely found away from the coast.
Moths.
An outstanding assemblage of two rare (RDB), 36 nationally scarce and two regionally notable moths are present, most of which are either chalk grassland specialists or are partly dependent on chalk grassland. The RDB species scarce forester ("Adscita globulariae") is present, and amongst many species of nationally scarce moths are the cistus forester ("Adscita geryon"), six-belted clearwing ("Bembecia scopigera"), oblique striped ("Phibalapteryx virgata"), pimpernel pug ("Eupithecia pimpinellata"), shaded pug ("Eupithecia subumbrata") and narrow-bordered bee hawk moth ("Hemaris tityus"). Larvae of these moths feed on the chalk grassland plants which are widespread on the plain. Other nationally scarce moths such as orange-tailed clearwing ("Synanthedon anthraciniformis") depend on the associated scrub habitats.
Bees.
The bee fauna is particularly rich in species which depend on chalk grassland. One of only two British populations of the endangered (RDB) mining bee "Melitta dimidiata" is present on the plain, and two other RDB species which occur are "Andrena hattorfiana" and its nest parasite the cuckoo bee "Nomada armata". This is a rare inland site for the nationally scarce brown-banded carder bee ("Bombus humilis"), and the only lowland English site for the broken-belted bumblebee ("Bombus soroeensis").
Flies.
The Diptera (flies) include four RDB species which depend on chalk grassland, the picture-wing flies "Chaetorellia loricata", "Urophora solstitialis" and "Terellia vectensis" and the hover fly "Volucella inflata".
Crustaceans.
Recent observations have shown that Salisbury Plain is an important site for the RDB crustacean, the fairy shrimp "Chirocephalus diaphanus" which is dependent on temporary pools, a rare and declining habitat. On the plain this habitat requirement is met by numerous pools created by repeated tank movements along the earth tracks which cross the chalk grassland.
Others.
Other nationally scarce invertebrates occur within the Orthoptera (grasshoppers and crickets), Heteroptera (bugs) and Coleoptera (beetles), the latter group including a RDB soldier beetle, "Cantharis fusca".
Birds.
The area as a whole is of national and international importance for breeding and wintering birds. It supports seven species listed on Annex 1 of the EC Directive on the Conservation of Wild Birds, populations of six species of Red Data bird and several species of candidate Red Data bird. Amongst the breeding birds three species are particularly noteworthy. Up to 20 pairs of stone curlew representing 12% of the British population breed on the plain. The area accounts for approximately 20% of breeding records for quail in Britain each year, and numbers of breeding Hobby are thought to exceed 1% of the British population on a regular basis. Other important breeding species include buzzard, barn owl, long-eared owl, nightingale, stonechat, whinchat, wheatear, corn bunting and, on occasion, Montagu's harrier.
The overall breeding assemblage is exceptionally diverse for a British dry grassland site. In winter the plain is an important area for foraging flocks of thrushes, finches and buntings. These, together with abundant small mammals are prey for wintering hen harrier, merlin and short-eared owl. Hen harriers occur in nationally significant numbers each winter, and the plain is an important winter roost for this species in southern England.
In 2003 the great bustard was reintroduced into Britain on Salisbury Plain.
Snakes and amphibians.
Other species of interest on Salisbury Plain include the great crested newt ("Triturus cristatus"). This newt occurs in dew ponds across the plain and in pools along the Bourne River, together with smooth newt ("Triturus vulgaris"), common frog ("Rana temporia") and common toad ("Bufo bufo"). Barred grass snake ("Natrix helvetica") are also often seen near pools, and common lizard ("Lacerta vivipara"), slowworm ("Anguis fragilis") and adder ("Vipera berus") are present.


Samuel Rowbotham

Samuel Birley Rowbotham (; 1816 – 23 December 1884, in London) was an English inventor and writer who wrote "Zetetic Astronomy: Earth Not a Globe" under the pseudonym Parallax. His work was originally published as a 16-page pamphlet (1849), and later expanded into a book (1865).
Rowbotham's method, which he called zetetic astronomy, models the Earth as a flat disc centered at the North Pole and bounded along its perimeter by a wall of ice, with the Sun, Moon, planets, and stars moving only several thousand miles above the surface of Earth.
Life.
Rowbotham started out as an organiser of an Owenite commune in The Fens, where he formulated his theories about the Earth. After measuring a lack of curvature on the long straight drainage ditches of the Bedford Levels in his first Bedford Level experiment, he was convinced of the flatness of the Earth and began to lecture on the topic. He took a little time to learn his trade, running away from a lecture in Blackburn when he couldn't explain why the hulls of ships disappeared before their masts when sailing out to sea. However, as he persisted in filling halls by charging sixpence a lecture, his quick-wittedness and debating skills were honed so much that he could "counter every argument with ingenuity, wit and consummate skill".
When finally pinned down to a challenge in Plymouth in 1864 by allegations that he wouldn't agree to a test, Parallax appeared on Plymouth Hoe at the appointed time, witnessed by Richard A. Proctor, a writer on astronomy, and proceeded to the beach where a telescope had been set up. His opponents had claimed that only the lantern of the Eddystone Lighthouse, some 14 miles out to sea, would be visible. In fact, only half the lantern was visible, yet Rowbotham claimed his opponents were wrong and that it proved the Earth was indeed flat so that many Plymouth folk left the Hoe agreeing that "some of the most important conclusions of modern astronomy had been seriously invalidated".
In 1861, Rowbotham married for a second time (to the 16-year-old daughter of his laundress) and settled in London, producing 14 children, of whom four survived. He was also alleged to be using the name "Dr. Samuel Birley", living in a beautiful 12-roomed house, selling the secrets for prolonging human life and curing every disease imaginable. Augustus De Morgan refers to him as S. Goulden. He patented a number of inventions, including a "life-preserving cylindrical railway carriage".
His book "Zetetic Astronomy: The Earth not a Globe" appeared in 1864. His lectures continued and concerned citizens addressed letters to the Astronomer Royal seeking rebuttals for his claims. A correspondent to the Leeds Times observed that "One thing he did demonstrate was that scientific dabblers unused to platform advocacy are unable to cope with a man, a charlatan if you will (but clever and thoroughly up in his theory), thoroughly alive to the weakness of his opponents".
Influence.
One of Rowbotham's followers, John Hampden, a Christian polemicist, gained notoriety by engaging in raucous public debates with leading scientists of the day. A bet involving the prominent naturalist Alfred Russel Wallace in the famous Bedford Level experiment led to several lawsuits for fraud and libel and Hampden's imprisonment.
In the United States, Rowbotham's ideas were taken up by the Christian Catholic Apostolic Church and promoted widely on their radio station. His work in the United States was continued by William Carpenter. Carpenter, a printer originally from Greenwich, England, a supporter of Rowbotham and published "Theoretical Astronomy Examined and Exposed — Proving the Earth not a Globe" in eight parts from 1864 under the name "Common Sense". He later emigrated to Baltimore where he published "A hundred proofs the Earth is not a Globe" in 1885.
Legacy.
After Rowbotham's death, Lady Elizabeth Blount continued the "Universal Zetetic Society" which Rowbotham had founded. They published a magazine entitled "The Earth Not a Globe Review" and remained active well into the early part of the 20th century. After World War I, the movement underwent a slow decline, but it was revived in 1956 as The Flat Earth Society.


779 Nina

779 Nina ("prov. designation": "or" ) is a large background asteroid, approximately in diameter, located in the central region of the asteroid belt. It was discovered on 25 January 1914, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. The metallic X-type asteroid with an intermediate albedo has a rotation period of 11.2 hours. It was named after the discoverer's sister, Nina Neujmina (1877–1956).
Orbit and classification.
"Nina" 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 central main-belt at a distance of 2.1–3.3 AU once every 4 years and 4 months (1,588 days; semi-major axis of 2.66 AU). Its orbit has an eccentricity of 0.23 and an inclination of 15° with respect to the ecliptic. The body's was first observed as and at Heidelberg Observatory on 16 December 1908 and 14 October 1912, respectively. The observation arc begins at Vienna Observatory on 31 July 1916, more than two years after to its official discovery observation at Simeiz Observatory on Crimea.
Naming.
This minor planet was after Nina Nikolaevna Neujmina (1877–1956), mathematician and sister of Russian discoverer Grigory Neujmin.
Physical characteristics.
In the Bus–Binzel SMASS classification, "Nina" is an X-type asteroid. It is also an X-type in both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2). Belskaya classifies "Nina" as a metallic M-type asteroid, which is the equivalent spectral type in the Tholen taxonomy for X-types with an intermediate albedo "(see below)".
Rotation period.
In June 1981, a rotational lightcurve of "Nina" was obtained from photometric observations by Alan Harris at the Table Mountain and Lowell observatories. Lightcurve analysis gave a rotation period of hours with a brightness variation of magnitude (). It was confirmed by Brian Warner at his Palmer Divide Observatory in Colorado in January 2009, who determined a period of hours with an amplitude of magnitude (). In September 2012, French amateur astronomer Gérald Rousseau obtained a period of hours with an amplitude of magnitude ().
Diameter and albedo.
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, "Nina" measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The "Collaborative Asteroid Lightcurve Link" adopts Petr Pravec's revised WISE-albedo of 0.1694 and takes a diameter of 77.46 kilometers based on an absolute magnitude of 8.1. The WISE team also published an alternative mean-diameter of () with an albedo of (). On 10 November 2005, an asteroid occultation of "Nina" gave a best-fit ellipse dimension of (), with a quality rating of 2. These timed observations are taken when the asteroid passes in front of a distant star.


589 Croatia

Croatia (minor planet designation: 589 Croatia), provisional designation , is a dark asteroid and parent body of the Croatia family, located in the outer regions of the asteroid belt, approximately 88 kilometers in diameter. It was discovered in 1906, by astronomer August Kopff at Heidelberg Observatory, and later named for the independent country of Croatia, then part of Austria-Hungary.
Discovery.
The asteroid was discovered on 3 March 1906, by German astronomer August Kopff at the Heidelberg-Königstuhl State Observatory in southwest Germany, with the use of the photographic method. In the moment of the discovery, the asteroid was 12.5mv and was in the constellation of Virgo. The discovery was published in the "Astronomische Nachrichten" magazine, in the article wrote by Professor Wolf. Later, some astronomers (Johann Palisa, Karl Lohnert and some others) were making measurements for the purpose of determining the orbital elements. From these measurements P. V. Neugebauer from Berlin and M.S. Mello and Simas from Trafaria (Lisbon) had independently determined the first orbital elements. Observations had continued, and among observers there were A. Kopff, E. Bianchi, A. Abetti, G. Zappa, P. Chafardet, E. Millosevich, J. Palisa, and some others. Observations were made from Berlin, Copenhagen, Rome, Arcetra and some other Italian cities.
Orbit and classification.
"Croatia" is the parent body of the Croatia family (), a small asteroid family of less than 100 known members. It orbits the Sun in the outer main belt at a distance of 3.0–3.3 AU once every 5 years and 7 months (2,032 days; semi-major axis of 3.14 AU). Its orbit has an eccentricity of 0.04 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins at Heidelberg, sixteen days after its official discovery observation.
Physical characteristics.
In the Tholen classification, "Croatia" is ambiguous, closest to a carbonaceous C-type and somewhat similar to that of an X-type asteroid, while the Wide-field Infrared Survey Explorer (WISE) characterized it as a primitive P-type asteroid. Nesvorný determined the overall spectral type for the Croatia family to be that of an X-type.
Rotation period.
In July 2013, the so-far best-rated rotational lightcurve of "Croatia" was obtained by astronomers Romain Montaigut, Arnaud Leroy, Raoul Behrend, René Roy, Donn Starkey, Maurice Audejean, Roberto Crippa and Federico Manzini. Lightcurve analysis gave a longer-than average rotation period of 24.821 hours with a brightness variation of 0.25 magnitude (). The result supersedes photometric observations by Brian Warner and by astronomers at the Palomar Transient Factory, which measured a shorter period of 11.7 and 16.385 hours with an amplitude of 0.16 and 0.32, respectively ().
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 WISE telescope, "Croatia" measures between 84.44 and 96.491 kilometers in diameter and its surface has an albedo between 0.041 and 0.06.
The "Collaborative Asteroid Lightcurve Link" derives an albedo of 0.0577 and a diameter of 87.66 kilometers based on an absolute magnitude of 9.0. The radius of (probably) 28.452 km (and, consequently, the superficial area of 2543.2 km2, and equatorial circumference of 89.385 km) were determined by use of Argelander's Method.
Naming.
This minor planet was named for the country of Croatia, then part of Austria-Hungary, after the suggestion made by astronomer Max Wolf. It also honors the foundation of the Astronomical Observatory of the Croatian Natural Sciences Society (Zagreb Observatory) in Zagreb.


Isogenous series

Isogenous is a term occasionally used in spectroscopy that denotes when two or more spectroscopic series of transition from a common state. The word was first used in this context in T.J. Stone & R.F. Barrow "Laser excited fluorescence spectra of gaseous formula_1", Canadian Journal of Physics. Vol. 53, p. 1976, October 1975. In this case, an excited state of gaseous formula_1 was pumped by an Argon ion laser; the excited state then relaxed to two closely separated low lying states giving two series of emission lines with a common origin.


Hugh Wilson (RAF officer)

Hugh Joseph Wilson known as (28 May 1908 5 September 1990), nicknamed "Willie", was a senior Royal Air Force officer. He served as the RAF's main chief test pilot for captured enemy aircraft in World War II and in November 1945 was the first man to exceed , flying a Gloster Meteor jet fighter.
Biography.
Born in 1908, Wilson was the only son of Alfred Wilson and Jessie (née Wood Young). He was educated at Hastings' University School, Merchant Taylors' School in Northwood and City of London School. After leaving school he began an apprenticeship with a cotton manufacturer.
RAF career.
On 13 September 1929, Wilson joined the RAF within the General Duties Branch on a short service commission. He trained at the No. 5 Flight Training School and was later posted to No. 111 Squadron. Exactly five years after joining the RAF in 1934 he was placed on the Reserve of Air Force Officers. Whilst on this reserve list he passed a conversion course on flying boats and also passed as a flying instructor.
In the mid-1930s he worked as a test pilot for Blackburn Aircraft and was, in 1938, the first to fly the Blackburn Roc. He later worked at the Royal Aircraft Establishment at Farnborough as a civil test pilot.
World War II.
Recalled to active service with the RAF in 1939, Wilson was the Commanding Officer of the Aerodynamic Flight of the RAE at RAF Farnborough.
Between 1941 and the end of the war Wilson was the RAF's main test pilot on all captured enemy aircraft. Flying these aircraft from RAF Farnborough (they had been repainted with RAF roundels), Wilson would evaluate their handling and performance (see Armin Faber incident).
After a short period working in America as a test pilot, Wilson joined No. 616 Squadron in 1944 to train pilots on Britain's first jet fighter, the Gloster Meteor. He subsequently became Officer Commanding of the Empire Test Pilots' School at RAF Cranfield.
World air speed record.
On 7 November 1945, flying the Gloster Meteor "Britannia" (EE454) over a course at Herne Bay in Kent, Wilson averaged a new world air speed record for a jet fighter of .
Later career.
After leaving the RAF with the rank of Group Captain, Wilson worked as an engine salesman for Blackburn Aircraft and Rolls-Royce.
Personal life.
Wilson was married twice, first to Isobel Moira Sergeant in 1947 (they had one son) and then in 1959 to Patricia Frances Shanley Warren and had two more sons. He died on the 5th September 1990 and was buried in a family grave in Highgate Cemetery.


Adobe Wallaby

Adobe Wallaby is an application that turns FLA files into HTML5. On March 8, 2011, Adobe Systems released the first version of an experimental Flash (FLA files) to HTML5 converter, code named "Wallaby". It has been quickly superseded by various other Adobe tools.
Support.
Adobe Wallaby supports almost half of all the functions in Adobe Flash, such as, Gradients, Buttons, and Scenes. However, there are also some functions that it does not support, for example, ActionScript 1-3, and 3D transforms.


List of quarter tone pieces

A selection of compositions using quarter tones:


Principal meridians of Alaska

The five principal meridians of Alaska are the Copper River meridian (established 1905), Fairbanks meridian (adopted 1910), Kateel River meridian (adopted 1956), Seward meridian (adopted 1911) and Umiat meridian (adopted 1956).


List of sundial mottos

Many sundials bear a motto to reflect the sentiments of its maker or owner.
References.
Notes
Footnotes


Maximum spacing estimation

In statistics, maximum spacing estimation (MSE or MSP), or maximum product of spacing estimation (MPS), is a method for estimating the parameters of a univariate statistical model. The method requires maximization of the geometric mean of "spacings" in the data, which are the differences between the values of the cumulative distribution function at neighbouring data points.
The concept underlying the method is based on the probability integral transform, in that a set of independent random samples derived from any random variable should on average be uniformly distributed with respect to the cumulative distribution function of the random variable. The MPS method chooses the parameter values that make the observed data as uniform as possible, according to a specific quantitative measure of uniformity.
One of the most common methods for estimating the parameters of a distribution from data, the method of maximum likelihood (MLE), can break down in various cases, such as involving certain mixtures of continuous distributions. In these cases the method of maximum spacing estimation may be successful.
Apart from its use in pure mathematics and statistics, the trial applications of the method have been reported using data from fields such as hydrology, econometrics, magnetic resonance imaging, and others.
History and usage.
The MSE method was derived independently by Russel Cheng and Nik Amin at the University of Wales Institute of Science and Technology, and Bo Ranneby at the Swedish University of Agricultural Sciences. The authors explained that due to the probability integral transform at the true parameter, the “spacing” between each observation should be uniformly distributed. This would imply that the difference between the values of the cumulative distribution function at consecutive observations should be equal. This is the case that maximizes the geometric mean of such spacings, so solving for the parameters that maximize the geometric mean would achieve the “best” fit as defined this way. justified the method by demonstrating that it is an estimator of the Kullback–Leibler divergence, similar to maximum likelihood estimation, but with more robust properties for some classes of problems.
There are certain distributions, especially those with three or more parameters, whose likelihoods may become infinite along certain paths in the parameter space. Using maximum likelihood to estimate these parameters often breaks down, with one parameter tending to the specific value that causes the likelihood to be infinite, rendering the other parameters inconsistent. The method of maximum spacings, however, being dependent on the difference between points on the cumulative distribution function and not individual likelihood points, does not have this issue, and will return valid results over a much wider array of distributions.
The distributions that tend to have likelihood issues are often those used to model physical phenomena. seek to analyze flood alleviation methods, which requires accurate models of river flood effects. The distributions that better model these effects are all three-parameter models, which suffer from the infinite likelihood issue described above, leading to Hall's investigation of the maximum spacing procedure. , when comparing the method to maximum likelihood, use various data sets ranging from a set on the oldest ages at death in Sweden between 1905 and 1958 to a set containing annual maximum wind speeds.
Definition.
Given an iid random sample {"x"1, ..., "x""n"} of size "n" from a univariate distribution with continuous cumulative distribution function "F"("x";"θ"0), where "θ"0 ∈ Θ is an unknown parameter to be estimated, let {"x"(1), ..., "x"("n")} be the corresponding ordered sample, that is the result of sorting of all observations from smallest to largest. For convenience also denote "x"(0) = −∞ and "x"("n"+1) = +∞.
Define the "spacings" as the “gaps” between the values of the distribution function at adjacent ordered points:
Then the maximum spacing estimator of "θ"0 is defined as a value that maximizes the logarithm of the geometric mean of sample spacings:
By the inequality of arithmetic and geometric means, function "S""n"("θ") is bounded from above by −ln("n"+1), and thus the maximum has to exist at least in the supremum sense.
Note that some authors define the function "S""n"("θ") somewhat differently. In particular, multiplies each "D""i" by a factor of ("n"+1), whereas omit the factor in front of the sum and add the “−” sign in order to turn the maximization into minimization. As these are constants with respect to "θ", the modifications do not alter the location of the maximum of the function "S""n".
Examples.
This section presents two examples of calculating the maximum spacing estimator.
Example 1.
Suppose two values "x"(1) = 2, "x"(2) = 4 were sampled from the exponential distribution "F"("x";"λ") = 1 − e−"xλ", "x" ≥ 0 with unknown parameter "λ" > 0. In order to construct the MSE we have to first find the spacings:
The process continues by finding the "λ" that maximizes the geometric mean of the “difference” column. Using the convention that ignores taking the ("n"+1)st root, this turns into the maximization of the following product: (1 − e−2"λ") · (e−2"λ" − e−4"λ") · (e−4"λ"). Letting "μ" = e−2"λ", the problem becomes finding the maximum of "μ"5−2"μ"4+"μ"3. Differentiating, the "μ" has to satisfy 5"μ"4−8"μ"3+3"μ"2 = 0. This equation has roots 0, 0.6, and 1. As "μ" is actually e−2"λ", it has to be greater than zero but less than one. Therefore, the only acceptable solution is
which corresponds to an exponential distribution with a mean of ≈ 3.915. For comparison, the maximum likelihood estimate of λ is the inverse of the sample mean, 3, so "λ"MLE = ⅓ ≈ 0.333.
Example 2.
Suppose {"x"(1), ..., "x"("n")} is the ordered sample from a uniform distribution "U"("a","b") with unknown endpoints "a" and "b". The cumulative distribution function is "F"("x";"a","b") = ("x"−"a")/("b"−"a") when "x"∈["a","b"]. Therefore, individual spacings are given by
Calculating the geometric mean and then taking the logarithm, statistic "S""n" will be equal to
Here only three terms depend on the parameters "a" and "b". Differentiating with respect to those parameters and solving the resulting linear system, the maximum spacing estimates will be
These are known to be the uniformly minimum variance unbiased (UMVU) estimators for the continuous uniform distribution. In comparison, the maximum likelihood estimates for this problem formula_7 and formula_8 are biased and have higher mean-squared error.
Properties.
Consistency and efficiency.
The maximum spacing estimator is a consistent estimator in that it converges in probability to the true value of the parameter, "θ"0, as the sample size increases to infinity. The consistency of maximum spacing estimation holds under much more general conditions than for maximum likelihood estimators. In particular, in cases where the underlying distribution is J-shaped, maximum likelihood will fail where MSE succeeds. An example of a J-shaped density is the Weibull distribution, specifically a shifted Weibull, with a shape parameter less than 1. The density will tend to infinity as "x" approaches the location parameter rendering estimates of the other parameters inconsistent.
Maximum spacing estimators are also at least as asymptotically efficient as maximum likelihood estimators, where the latter exist. However, MSEs may exist in cases where MLEs do not.
Sensitivity.
Maximum spacing estimators are sensitive to closely spaced observations, and especially ties. Given
we get
When the ties are due to multiple observations, the repeated spacings (those that would otherwise be zero) should be replaced by the corresponding likelihood. That is, one should substitute formula_11 for formula_12, as
since formula_14.
When ties are due to rounding error, suggest another method to remove the effects.
Given "r" tied observations from "x""i" to "x""i"+"r"−1, let "δ" represent the round-off error. All of the true values should then fall in the range formula_15. The corresponding points on the distribution should now fall between formula_16 and formula_17. Cheng and Stephens suggest assuming that the rounded values are uniformly spaced in this interval, by defining
The MSE method is also sensitive to secondary clustering. One example of this phenomenon is when a set of observations is thought to come from a single normal distribution, but in fact comes from a mixture normals with different means. A second example is when the data is thought to come from an exponential distribution, but actually comes from a gamma distribution. In the latter case, smaller spacings may occur in the lower tail. A high value of "M"("θ") would indicate this secondary clustering effect, and suggesting a closer look at the data is required.
Moran test.
The statistic "Sn"("θ") is also a form of Moran or Moran-Darling statistic, "M"("θ"), which can be used to test goodness of fit.
It has been shown that the statistic, when defined as
is asymptotically normal, and that a chi-squared approximation exists for small samples. In the case where we know the true parameter formula_20, show that the statistic formula_21 has a normal distribution with
where "γ" is the Euler–Mascheroni constant which is approximately 0.57722.
The distribution can also be approximated by that of formula_23, where
in which
and where formula_26 follows a chi-squared distribution with formula_27 degrees of freedom. Therefore, to test the hypothesis formula_28 that a random sample of formula_27 values comes from the distribution formula_30, the statistic formula_31 can be calculated. Then formula_28 should be rejected with significance formula_33 if the value is greater than the critical value of the appropriate chi-squared distribution.
Where "θ"0 is being estimated by formula_34, showed that formula_35 has the same asymptotic mean and variance as in the known case. However, the test statistic to be used requires the addition of a bias correction term and is:
where formula_37 is the number of parameters in the estimate.
Generalized maximum spacing.
Alternate measures and spacings.
 generalized the MSE method to approximate other measures besides the Kullback–Leibler measure. further expanded the method to investigate properties of estimators using higher order spacings, where an "m"-order spacing would be defined as formula_38.
Multivariate distributions.
 discuss extended maximum spacing methods to the multivariate case. As there is no natural order for formula_39, they discuss two alternative approaches: a geometric approach based on Dirichlet cells and a probabilistic approach based on a “nearest neighbor ball” metric.


725 Amanda

725 Amanda ("prov. designation:" "or" ) is a dark background asteroid, approximately in diameter, that is located in the central regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 21 October 1911. The carbonaceous C-type asteroid (CSU/C0) has a short rotation period of 3.7 hours. It was named after Amanda Schorr, wife of German astronomer Richard Schorr (1867–1951).
Orbit and classification.
"Amanda" 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 central asteroid belt at a distance of 2.0–3.1 AU once every 4 years and 2 months (1,507 days; semi-major axis of 2.57 AU). Its orbit has an eccentricity of 0.22 and an inclination of 4° with respect to the ecliptic. The body's observation arc begins at Vienna Observatory on 29 September 1915, almost four years after its official discovery observation.
Naming.
This minor planet was named after Amanda Schorr, wife of Richard Schorr (1867–1951), a German astronomer at Bergedorf Observatory, after whom asteroid 1235 Schorria and lunar crater "Schorr" were named. The asteroid's name was proposed by Palisa in 1913, on the occasion of the 24th meeting of the "Astronomische Gesellschaft" in Hamburg, Germany (). The was also mentioned in "The Names of the Minor Planets" by Paul Herget in 1955 ().
Physical characteristics.
In the Tholen classification, "Amanda"s spectral type is closest to that of a carbonaceous C-type asteroid, yet also somewhat similar to a stony S-type with an "unusual" spectrum (CSU). In the taxonomy by Barucci (1987), the asteroid is a dark C-type (C0).
Rotation period and poles.
A rotational lightcurve of "Amanda" was obtained from photometric observations by European astronomers at the La Silla Observatory before 1995. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of magnitude ().
In October 2010, French amateur astronomer Maurice Audejean determined a concurring period of () hours with an amplitude of () magnitude (), while in August 2018, a further observation by the TESS-team reported a period of () hours and an amplitude of () magnitude ().
In 2016, a modeled lightcurve gave a sidereal period of hours using data from the Uppsala Asteroid Photometric Catalogue, the Palomar Transient Factory survey, and individual observers, as well as sparse-in-time photometry from the NOFS, the Catalina Sky Survey, and the La Palma surveys . The study also determined two spin axes of (145.0°, −63.0°) and (320.0°, −70.0°) in ecliptic coordinates (λ, β).
Diameter and albedo.
According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), "Amanda" measures (), () and () in diameter and its surface has an albedo of (), () and (), respectively.
The "Collaborative Asteroid Lightcurve Link" derives an albedo of 0.0824 and calculates a diameter of 21.56 kilometers based on an absolute magnitude of 11.66. Alternative mean-diameters published by the WISE team include (), (), () and () with a corresponding albedo of (), (), () and ().


847 Agnia

847 Agnia is a minor planet orbiting the Sun. It is approximately 28 kilometers in diameter.
The spectrum of this object indicates that it is an S-type asteroid with both low and high calcium forms of pyroxene on the surface, along with less than 20% olivine. The high-calcium form of pyroxene forms 40% or more of the total pyroxene present, indicating a history of igneous rock deposits. This suggests that the asteroid underwent differentiation by melting, creating a surface of basalt rock.
847 Agnia is the namesake of the Agnia family of asteroids that share similar orbital elements and physical properties. The members of this family, including 847 Agnia, most likely formed from the breakup of a basalt object, which in turn was spawned from a larger parent body that had previously undergone igneous differentiation. Other members of this family include 1020 Arcadia, 1228 Scabiosa, 2401 Aehlita, and 3395 Jitka
Photometric observations of this asteroid collected during 2004–2005 show a rotation period of 14.827 ± 0.001 hours with a brightness variation of 0.45 ± 0.03 magnitude.


Contact microphone

A contact microphone, also known as a piezo microphone, is a form of microphone that senses audio vibrations through contact with solid objects. Unlike normal air microphones, contact microphones are almost completely insensitive to air vibrations but transduce only structure-borne sound. Often used as acoustic leakage probes, they also enjoy wide usage by noise music artists experimenting with sound. Contact microphones can be used to amplify sound from acoustic musical instruments, to sense drum hits, for triggering electronic samples, and to record sound in challenging environments, such as underwater under high pressure.
Contact microphones based on piezo materials are passive and high-impedance, which can make them sound 'tinny' without a matching preamp.
The most commonly available contact microphone element is made of a thin piezoelectric ceramic round glued to a thin brass or alloy metal disc. This center disc is positively charged while the brass disc is negatively charged. If the silver disc is cracked or scorched, the piezo will no longer function at full sensitivity.