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Talk:Hydrogen fuel

Transport
The statement, "Hydrogen can also be transported (like electricity) to locations where it is needed." is rather confusing since transportation is one of hydrogen's drawbacks. Nothing, other than information, can be transported like electricity. If a comparison is to be made then it should be done with natural gas, also a substance difficult (read expensive) to transport. Local infrastructure could be built out to deliver hydrogen much like natural gas, but cost eventually limits distance delivery. I have therefore changed this statement to read, "Hydrogen can also be transported (like natural gas) to locations where it is needed.

I also have issue with the statement "Hydrogen is high in energy..." but don't have time for a fix right now. The article is definitely a proponent of United States National Renewable Energy Laboratory's POV and needs work.

Truth is commercial quantities of hydrogen can be economically produced anywhere natural gas is available. The technology is now available to produce commerical quantities of hydrogen at every filling station that has natural gas with a minimal investment in equipment that would cost consumers less than $3.00 for an equivalent quantity of a gallon of gasoline. So there really is no need to transport hydrogen. — Preceding unsigned comment added by 192.135.178.250 (talk) 17:12, 18 April 2012 (UTC)

Energy
I came here looking for the data about energy released from hydrogen combustion (to compare with some others) and couldnt find it. In the oxyhydrogen flame page they state the Kj per mole, but that article is centered on a precise topic. I was expecting at least, the amount of energy released per mole and thus per Kg of hydrogen, ideally with the complete calculation, which is pretty straitforward, as you need the balanced stochiometric reaction equation, and then you calculate the net energy from the bond energies, adding the destroyed bonds and substracting the newly formed ones. If I dont do the edit, please consider adding this data. — Preceding unsigned comment added by 191.115.177.147 (talk) 02:55, 14 June 2016 (UTC)

 * I came here looking for the same. The article seems rather muddled with a lot of it written more journalistically than technically.Lkingscott (talk) 18:45, 10 January 2023 (UTC)

in need of rewrite
this stuff doesn't sound like wikipedia...

i'll get to rewriting this stuff soon

PeregrineAY 05:25, 2005 Apr 4 (UTC)

 * Please do rewrite it. The author of this article wrote a few energy-related articles, all of which had serious POV issues. Your help is welcome. Rhobite 06:00, Apr 4, 2005 (UTC)

 * Since it seems this page is near to a rewrite, I won't edit it, but I do have some suggestions for whoever might. Hydrogen as a fuel has many advantages and disadvantages over other possible fuels.
 * Hydrogen does burn clean in a car, but hydrogen is curruently produced using hydrocarbons or other dirty methods that produce CO2 and other gasses. It will not reduce and may actually increase pollution for a while until hydrocarbons become too expensive, or pollution becomes a serious concern. [That is not correct. Hydrogen cars will reduce our carbon footprint in the automobile industry if we use natural gas to generate hydrogen fuel in place of refining crude and burning gasoline]. The main reason touted by politicions is to reduce polution, and people should be aware that hydrogen will not immediately do this. [Wrong as explained above.]
 * Hydrogen is more inefficent than gasoline. It would be possible to reverse the combusion of gasoline using electrical and chemical reactions (we could basically make our own custom hydrocarbons out of water and free CO2), and these would have more power for a smaller storage tank mass (liquid hydrogen has low mass itself but requires vast storage tank mass). This would be a clean cycle (get back what you put in), same as hydrogen, if more complex. Currently the most efficient formula for portable energy seems to be Boron . Burn solid boron and gaseous oxygen, and produce glass-like boria, which can be stored separated back to boron and oxygen at a power plant. Almost any reactive element (beryllium, zinc, carbon) can work for this. However, hydrogen is very abundant and directly splits with just electricity.
 * Hydrogen leaks around 1.7% per day from any container small enough to put in a car. This is bad in that the hydrogen may (I have not heard conclusive proof either way) escape the Earth's atmosphere in the same way helium does, without reacting. This is bad in that the hydrogen could be permanently lost (?) [very subjective and speculative]
 * Now, before I sound too much against hydrogen: We will run out of "free" fossil fuels (fuels that give us more energy than we use in getting them) that will fit in a car, possibly within our lifetimes. Our only choice is to switch to a renewable portable energy source for cars. Electrical batteries would work, but take dangerous chemicals and require replacement. Hydrogen is the best cantidate thus far that has seen practical applications.
 * When we do run out of fossil fuels, if we are using the last drops in our cars, we will suddenly have to replace all our cars. If, however, we've replaced our cars with hydrogen cars (or some other type using a renewable reaction), and are cracking the last breath of methane to make hydrogen, we already have nuclear and solar power plants to provide the electricity to break water (via electrolysis) to hydrogen, and thus we have no car crisis.
 * Thus it is, that hydrogen is a good possible step away from our reliance on fossil fuels. We won't stop using them, but we will be able to. Splarka 01:39, 7 Apr 2005 (UTC)

 * On methane - "However, this reaction causes a side production of carbon dioxide and carbon monoxide, which are greenhouse gases and contribute to global warming.[1]" Well, so is methane. This is just a sniping point that doesn't wash.  — Preceding unsigned comment added by 173.72.164.2 (talk) 18:17, 19 December 2017 (UTC)

This article should be a redirect to Hydrogen economy
The hydrogen economy article is much more detailed, organized, and balanced. If there isn't consensus for deletion/merge/redirect then a synopsis from that article should be put here, currently this article is woefully disorganized. zen master   T  02:28, 7 Apr 2005 (UTC)

Agreed. This article is not improving and still bears a strong sense of advertising. The information here is already available in fuel cell, hydrogen economy and hydrogen car in greater detail and without the POV. Amadeust 03:44, 7 Apr 2005 (UTC)

 * Agreed. Anything not taken up by those articles can be put in a small paragraph of Hydrogen (after links to fuel cell, hydrogen economy, and hydrogen car), possibly something like Other uses as a fuel (space shuttle, welding, lighter-than-air craft, historic uses) Splarka 05:08, 7 Apr 2005 (UTC)

 * I created the redirect. zen master   T  05:45, 7 Apr 2005 (UTC)

Hydrogen fuel and the concept of a hydrogen economy are not the smae thing. ChildofMidnight (talk) 04:59, 6 March 2009 (UTC)

— unsigned comment added by Ernest R(new comment 12 02 09)I notice that nearly this entire group of articles seems to be heavily biased toward hydrogen's roll in the Green Energies movement. I would be much happier if it were presented just like any other Engineering topic. A good example would be the Oxyhydrogen flame article which is linked here. More candidly, I'm getting a little tired of the 'issues' obscuring the simple science in so many different fields here on Wikipedia. I feel that articles about Hydrogen as a 'green' energy should be separate from the main thread, as the side issue that they represent. The main thread should NOT be written by anyone but a thermodynamic engineer. I want to check or learn simple facts about the practical applications of a technology. I'm barely interested in the whatever politics or social movements or applications may have attached themselves to a given technology, (justly or otherwise). Could we please try to keep sociology and hard science separate, with a sideline for where they inevitably overlap? End of soapbox. —Preceding unsigned comment added by —Preceding unsigned comment added by 216.163.128.130 (talk) 00:32, 3 December 2009 (UTC)

To do
Re add any useful content from the article's history. ChildofMidnight (talk) 05:00, 6 March 2009 (UTC)

Stub?
Why is this article so small? I hear about hydrogen all the time. I'd expect a full page article, not this little stub.--Metallurgist (talk) 20:45, 29 March 2009 (UTC)

 * I agree it needs to be expanded. Hopefully someone will work on it. The article on hydrogen economy is much longer, but I don't think it's the same subject and so shouldn't be merged at this time. ChildofMidnight (talk) 01:55, 29 June 2009 (UTC)

 * This article worries me too - there's more info at Hydrogen and at Hydrogen economy, which the reader isn't going to be directed to very clearly. Also the lead isn't a proper lead, and no references for most of the article. PamD (talk) 22:58, 14 March 2010 (UTC)

I agree. The article is very short and should be added onto. — Preceding unsigned comment added by 96.227.250.8 (talk) 22:47, 20 October 2012 (UTC)

Internal combustion vs fuel cell
This article seems to miss very important aspects of "Hydrogen energy". Focusing on classical combustion and stating that smaller devices can be powered by fuel cells completely omits the existence of renewable hydrogen community powering systems, whereby the excess energy produced by renewable energy sources is stored as hydrogen and released back to the grid upon need thanks to massive fuel cell systems. —Preceding unsigned comment added by Gregory Dziedzic (talk • contribs) 13:54, 28 May 2010 (UTC)

 * Hydrogen can also be burnt in Stirling engines. Either direct drive of the wheels or by conversion to electricity.

 * Boil off of liquid hydrogen is a major problem. It may be impractical to solve for cars but trains and aircraft can overcome it by refueling every day.

 * The Reaction Engines Scimitar is an example of an aircraft engine that burns hydrogen.

 * Sea going ships cannot refuel every day but they can carry high power refrigeration equipment. Andrew Swallow (talk) 13:19, 24 May 2012 (UTC)

Hydrogen in the atmosphere
As an atmospheric chemist, I object to the sentence "Since hydrogen gas is so light, it rises in the atmosphere and is therefore rarely found in its pure form, H2.[1] ". The background atmosphere generally contains about 550 ppb H2. Loss through gravitational separation is NOT a significant loss process for H2; the main loss processes are uptake by the soils and oxidation by atmospheric oxidants. See for example this review article for an overview of the processes that are important: http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0889.2009.00416.x/abstract.

Gravitational settling of gases rarely plays an important role in the atmosphere, since the atmosphere is too well-mixed for that. "Heavy" CFC gases do not remain at the Earth's surface either. Atmospheric escape only takes place in the highest atmospheric layers. (Anneke Batenburg) — Preceding unsigned comment added by 193.167.228.180 (talk) 12:07, 10 July 2015 (UTC)

new sections
hydrogen chemistry and production needs to be separated pls. Mion (talk) 08:14, 22 November 2013 (UTC)

Added Sources
Added sources from LSU databases:, , ,

WTR.Monkey (talk) 22:05, 20 February 2015 (UTC)

Energy released
The article definitely needs energy released per mole of hydrogen, both by combustion or when it's allowed to react galvanically. Hydrogen fuel isn't just combustion but it seems this article fails to address that. — Preceding unsigned comment added by Purgatoryoflife (talk • contribs) 02:00, 5 December 2016 (UTC)

 * Ditto! I came here looking for this.Lkingscott (talk) 18:52, 10 January 2023 (UTC)

Hydrogen fuel
Does hydrogen fuel cause pollution and if then which Ayushnikhara (talk) 16:57, 30 May 2019 (UTC)
 * Presumably ICE vehicles would have to meet Euro 7 NOx limits - https://theicct.org/sites/default/files/eu-commission-euro-7-and-VI-may2021.pdf - if anyone has more info please add Chidgk1 (talk) 18:31, 14 June 2021 (UTC)
 * This is a very wide ranging question.
 * If you are talking about its production, then it depends how it is produced. E.g. steam cracking of methane produces CO2 pollution. Electrolysis of water is probably pollution free, but chemicals may be needed in the water for the electrolysis and also depending on the source of the electricity. Plasma cracking of methane is potentially clean and the carbon produced has potential commercial uses. However methane from fossil sources could cause pollution due to aquifer contamination, drilling chemicals, well chemical leaks into the sea, etc...
 * If you are talking about its use, then it depends how it is used as a fuel. I.e. burning in an internal combustion engine has the possibility of generating NOX emissions.
 * In a fuel cell no direct emissions will be produced, but chemicals may be needed in the cell, etc.
 * If it is simply burnt directly for heating, it is unlikely to produce any identifiable pollution.
 * Hydrogen is also a potentially good option to replace coal for iron ore smelting. Iron ore will have impurities which may cause pollution during the smelting process.
 * Etc...
 * Lkingscott (talk) 19:07, 10 January 2023 (UTC)

Bio diesel
What is bio diesel 2409:4042:E8D:209A:0:0:234B:D212 (talk) 14:54, 2 January 2022 (UTC)

 * Bio Diesel has nothing to do with Hydrogen fuel. Why ask about it here? There are plenty of articles about it if you use your favourite search engine. FYI Bio Diesel is just a type of hydrocarbon Diesel made from biological sources rather than fossil sources.Lkingscott (talk) 18:56, 10 January 2023 (UTC)

title: Talk:Hydrogen fuel


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Clarence R. Huebner

Lieutenant General Clarence Ralph Huebner (November 24, 1888 – September 23, 1972) was a highly decorated senior officer of the United States Army who saw distinguished active service during both World War I and World War II. Perhaps his most notable role was as the Commanding General (CG) of the 1st Infantry Division (nicknamed "The Big Red One") during the Normandy landings of World War II. From January 1945, through the end of World War II, Huebner commanded V Corps (United States).

World War I
A farm boy from Bushton, Kansas, who spent almost seven years serving from private to sergeant in the 18th Infantry Regiment, Huebner received a regular commission in November 1916.

During World War I Huebner served on the Western Front and was sent to France with his regiment, the 28th Infantry, which later became part of the 1st Infantry Division ("The Big Red One"), shortly after the American entry into World War I. The division was the first of the American Expeditionary Force (AEF) to be sent overseas during the war. The following year he participated in the first American regimental assault at Cantigny, through Soissons, Saint-Mihiel, and the Meuse-Argonne. For his service in this war, he received two Distinguished Service Crosses, an Army Distinguished Service Medal, and a Silver Star. He commanded the 2nd Battalion, 28th Infantry at Cantigny after his commanding officer was killed, and later commanded the regiment, one of the youngest regimental commanders in the AEF.

Remaining in the army after the war, Huebner attended the United States Army Command and General Staff School at Fort Leavenworth in 1924 and served on its faculty from 1929 to 1933.

Division command
In 1943, Huebner relieved the popular commander of the 1st Infantry Division, General Terry Allen, in a move engineered by General Omar N. Bradley. While the 1st Infantry Division had enjoyed considerable combat success under Allen's leadership, Bradley was highly critical of both Allen and assistant division commander Theodore Roosevelt Jr.'s wartime leadership style, which favored fighting ability over drill and discipline: "While the Allies were parading decorously through Tunis," Bradley wrote, "Allen's brawling 1st Infantry Division was celebrating the Tunisian victory in a manner all its own. In towns from Tunisia all the way to Arzew, the division had left a trail of looted wine shops and outraged mayors. But it was in Oran...that the division really ran amuck. The trouble began when SOS (Services of Supply) troops, long stationed in Oran, closed their clubs and installations to our combat troops from the front. Irritated by this exclusion, the 1st Division swarmed into town to 'liberate' it a second time." Despite this, Bradley admitted that "none excelled the unpredictable Terry Allen in the leadership of troops."

Upon assuming command, Huebner immediately ordered a series of close-order drills, parades, and weapons instruction for the 1st Infantry Division, including its veterans, who had just finished a bloody series of engagements with German forces in Sicily. This did not endear him to the enlisted men of the division, who made no attempt to hide their preference for Allen. As one of the men of the Big Red One said in disgust, "Hell's bells! We've been killing Germans for months and now they are teaching us to shoot a rifle? It doesn't make any sense."

Supported by Bradley and Eisenhower, Huebner persisted, and the morale of the division gradually recovered. Huebner, aided by Brigadier General Willard G. Wyman, his assistant division commander, led the division in the assault on Omaha Beach on D-Day, followed by a successful infantry attack at Saint-Lô. The division would later repel a German counteroffensive at Mortain, and pursue the German Army across France, culminating in the Battles of Aachen and the Huertgen Forest.

V Corps command
In January 1945 Huebner took command of the V Corps, which he directed from the Rhine to the Elbe, where his troops made first contact with the Red Army. He commanded V Corps until November 11, 1945.

Postwar service
After World War II, Huebner served as Assistant Army Chief of Staff (G-3) at the Pentagon from late 1945 until 1946 when he became Chief of Staff for the United States European Command (EUCOM). He was promoted to lieutenant general on March 28, 1947 and also served as Deputy Commander in Chief of EUCOM from 1947 to 1950. He was the last Military Governor (acting) of the American Zone in Germany from May 15, 1949 to September 1, 1949.

Huebner retired from the army on November 30, 1950.

Later years

On September 1, 1951, Huebner became director of New York State's Civil Defense Commission, a post he held until January 1961. A strong advocate of the building of fallout shelters, Huebner believed the United States population would eventually be forced to live full-time in underground shelters and "would see the sunshine only by taking a calculated risk".

Huebner married Florence Barrett in 1921. Following her death in 1966, Huebner married Anna Imelda Mathews in 1968. She died in 1974. All three are buried together in Arlington National Cemetery.

In popular culture
Huebner was portrayed by Charles Macaulay in the 1980 film The Big Red One, in the opening sequence set in World War I and, in the reconstructed extended version, in 1944 just prior to the Battle of Huertgen Forest.

Decorations
Huebner received the following honors and awards during his military career:

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Clarence R. Huebner


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Eritrea national football team

The Eritrea national football team represents Eritrea in men's international football and it is controlled by the Eritrean National Football Federation (ENFF). It is nicknamed the Red Sea Boys. It has never qualified for the finals of the FIFA World Cup or the Africa Cup of Nations. Asmara side Red Sea FC are the main supplier for the national team and the team represents both FIFA and Confederation of African Football (CAF). Out of 211 national teams in the FIFA men's team world rankings, they are the only one that is unranked.

History
An Eritrean team participated in a friendly tournament in Sudan in 1992, the year before Eritrea achieved independence. Eritrea participated in the 1994 CECAFA Cup, organised by the Council for East and Central Africa Football Association, even though the ENFF was not founded until 1996. The first full international was in the 1999 CECAFA Cup, the year after the ENFF joined the CAF and FIFA. They participated in the qualifying rounds of the 2000 African Cup of Nations and the 2002 World Cup, and subsequent editions until 2008. They have also appeared intermittently in the CECAFA Cup.

In the 2000 Africa Cup of Nations qualifiers, Eritrea managed a scoreless home draw versus Cameroon and a 1–0 home win over Mozambique. They finished second in their three team group, and advanced to a playoff round where they faced Senegal and Zimbabwe, but ultimately lost all four matches in that final stage.

In the first round of the qualifiers for the 2002 World Cup, they were drawn against Nigeria, and were defeated 4–0 in the away leg, after a goalless draw at home. The coach was Yilmaz Yuceturk.

In the first round of the 2006 World Cup qualifiers, Sudan was Eritrea's first round opponent. Eritrea lost the first leg 3–0, before another goalless draw in Asmara. The coach was Eritrean Tekie Abraha.

In group 6 of the qualifiers for the 2008 Africa Cup of Nations, under the guidance of Romanian Dorian Marin, Eritrea finished second behind Angola, failing to qualify for the final tournament. They beat Kenya twice and drew at home to Angola.

In the first round of the 2014 World Cup qualifiers, Eritrea faced Rwanda. The first leg in Asmara ended in a 1–1 draw (and saw Eritrea's first ever goal in a World Cup qualification match), but Rwanda took the second leg by a score of 3–1.

In the first round of the 2018 World Cup qualifiers, Eritrea faced Botswana. The first leg in Asmara saw Botswana win 2–0, and the second leg in Francistown saw Botswana win 3–1, with Botswana winning 5–1 on aggregate.

In the first round of the 2022 World Cup qualifiers, Eritrea faced Namibia. The first leg in Asmara saw Namibia win 2–1, and the second leg saw Namibia win 2–0; Namibia won 4–1 on aggregate.

Eritrea withdrew from the 2023 Africa Cup of Nations qualifiers and the 2026 World Cup qualifiers.

Withdrawals from major tournament qualifying
On 30 March 2014, Eritrea withdrew from the preliminary round of the 2015 Africa Cup of Nations qualifiers, likely due to a rising number of the Eritrean national team players defecting from Eritrea during away matches. They were intended to play against South Sudan, who were awarded a walkover.

On 2 March 2022, Eritrea withdrew from the preliminary round of the 2023 Africa Cup of Nations qualifiers due to the lack of a stadium that meets the requirements set by CAF to host its international matches. They were intended to play against Botswana.

In November 2023, Eritrea, who were drawn into Group E alongside Morocco, Zambia, Tanzania, Congo and Niger, pulled out of the 2026 World Cup qualifiers, citing the reason as being the refusal of Zemede Tekle, who is the Eritrean Commissioner for Sports and Culture, to participate in the playoffs.

Defections
Recent years have seen a high number of refugees leaving Eritrea, and some athletes travelling to competitions abroad have taken the opportunity to abscond. In December 2012, 17 Eritrean footballers and the team's doctor vanished after the CECAFA championship tournament in Uganda and all applied for asylum in the country. Four players of Red Sea FC defected after a CAF Champions League 2006 match in Nairobi, Kenya, and up to 12 members of the national side after the 2007 CECAFA Cup in Tanzania. Another 6 players sought asylum in Angola in March 2007 after a group 6 qualifying game for the 2008 Africa Cup of Nations. Three more players from the national team sought asylum in Sudan.

Eritrea withdrew from the 2008 CECAFA Cup, and from the common qualifying tournament shared by the 2010 World Cup and the 2010 Africa Cup of Nations. Given the number of players seeking asylum, the Eritrean government began requiring athletes to pay a 100,000 nakfa surety before traveling abroad.

Eritrea returned to the 2009 CECAFA Cup in Nairobi. A young squad was assembled with just 12 days' training. In Group B, they gained a surprise draw with Zimbabwe, lost narrowly to Rwanda, and beat Somalia 3–1. They were easily beaten 4–0 in the quarter-finals by Tanzania. Twelve squad members failed to report for the return flight, and sought the assistance of the Refugee Consortium of Kenya. They were believed to be in hiding in Eastleigh, an eastern suburb of Nairobi home to many immigrants. Nicholas Musonye, the secretary-general of CECAFA, feared that the government might react by refusing to let the team travel abroad in future. The twelve players were later granted interim asylum by the United Nations High Commissioner for Refugees in Kenya. Eleven of these players have since travelled to Adelaide in Australia with two of them, Samuel Ghebrehiwet and Ambes Sium, signing for Gold Coast United in the A-League in August 2011.

In the first round of the qualifiers for the 2018 World Cup, ten players from the Eritrean football team refused to return home after playing a World Cup qualifying match in Botswana and were granted asylum there.

In September 2019, four members of the national Under-20 team sought asylum in Uganda after the team qualified for the semi-finals of a competition. A few months later in December, a further seven players selected for the international team refused to return home and sought asylum in Uganda after a tournament. In October 2021, five footballers from the country's under-20 women's team also disappeared when on international duty in Uganda.

Results and fixtures
The following is a list of match results in the last 12 months, as well as any future matches that have been scheduled.

Coaching history

 * 🇪🇷 Tekie Abraha (1991–1996)
 * 🇪🇬 Mushir Osman (1998–1999)
 * 🇪🇷 Tekie Abraha (1999–2000)
 * 🇹🇷 Yılmaz Yücetürk (2000–2002)
 * 🇪🇷 Negash Teklit (2002, caretaker)
 * 🇲🇪 Vojo Gardašević (2002)
 * 🇪🇷 Tekie Abraha (2003)
 * 🇪🇷 Mrad Abdul Tesfay (2004)
 * 🇷🇴 Dorian Marin (2006–2007)
 * 🇳🇱 René Feller (2007–2008)
 * 🇪🇷 Negash Teklit (2009–2012)
 * 🇪🇷 Omar Ahmed Hussein (2013–2015)
 * 🇪🇷 Alemseged Efrem (2015–present)

Latest squad
The following players were selected for the 2022 FIFA World Cup qualifiers against Namibia on 10 September 2019.

Caps and goals correct as of 10 September 2019, after the match against Namibia.

Player records

 * Players in bold are still active with Eritrea.

All-time record

 * Key

 * Pld = Matches played
 * W = Matches won
 * D = Matches drawn
 * L = Matches lost

 * GF = Goals for
 * GA = Goals against
 * GD = Goal differential
 * Countries are listed in alphabetical order

As of 25 January 2020

title: Eritrea national football team


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Opéra comique

Opéra comique (plural: opéras comiques) is a genre of French opera that contains spoken dialogue and arias. It emerged from the popular opéras comiques en vaudevilles of the Fair Theatres of St Germain and St Laurent (and to a lesser extent the Comédie-Italienne), which combined existing popular tunes with spoken sections. Associated with the Paris theatre of the same name, opéra comique is not necessarily comical or shallow in nature; Carmen, perhaps the most famous opéra comique, is a tragedy.

Use of the term
The term opéra comique is complex in meaning and cannot simply be translated as "comic opera". The genre originated in the early 18th century with humorous and satirical plays performed at the theatres of the Paris fairs which contained songs (vaudevilles), with new words set to already existing music. The phrase opéra comique en vaudevilles or similar was often applied to these early-stage works. In the middle of the 18th century, composers began to write original music to replace the vaudevilles, under the influence of the lighter types of Italian opera (especially Giovanni Battista Pergolesi's La serva padrona). This form of opéra comique was often known as comédie mêlée d'ariettes, but the range of subject matter it covered expanded beyond the merely comic. By the 19th century, opéra comique often meant little more than works with spoken dialogue performed at the Opéra-Comique theatre, as opposed to works with recitative delivery which appeared at the Paris Opéra. Thus, probably the most famous of all opéras comiques, Georges Bizet's Carmen, is on a tragic subject. As Elizabeth Bartlet and Richard Langham Smith note in their Grove article on the subject, composers and librettists frequently rejected the use of the umbrella term opéra comique in favor of more precise labels.

Beginnings
Opéra comique began in the early eighteenth century in the theatres of the two annual Paris fairs, the Foire Saint Germain and the Foire Saint Laurent. Here plays began to include musical numbers called vaudevilles, which were existing popular tunes refitted with new words. The plays were humorous and often contained satirical attacks on the official theatres such as the Comédie-Française. In 1715 the two fair theatres were brought under the aegis of an institution called the Théâtre de l'Opéra-Comique. In spite of fierce opposition from rival theatres the venture flourished and leading playwrights of the time, including Alain-René Lesage and Alexis Piron, contributed works in the new form.

Late 18th century
The Querelle des Bouffons (1752–54), a quarrel between advocates of French and Italian music, was a major turning-point for opéra comique. Members of the pro-Italian faction, such as the philosopher and musician Jean-Jacques Rousseau, attacked serious French opera, represented by the tragédies en musique of Jean-Philippe Rameau, in favor of what they saw as the simplicity and "naturalness" of Italian comic opera (opera buffa), exemplified by Pergolesi's La serva padrona, which had recently been performed in Paris by a traveling Italian troupe. In 1752, Rousseau produced a short opera influenced by Pergolesi, Le Devin du village, in an attempt to introduce his ideas of musical simplicity and naturalness to France. Its success attracted the attention of the Foire theatres. The next year, the head of the Saint Laurent theatre, Jean Monnet, commissioned the composer Antoine Dauvergne to produce a French opera in the style of La serva padrona. The result was Les troqueurs, which Monnet passed off as the work of an Italian composer living in Vienna who was fluent in French, thus fooling the partisans of Italian music into giving it a warm welcome. Dauvergne's opera, with a simple plot, everyday characters, and Italianate melodies, had a huge influence on subsequent opéra comique, setting a fashion for composing new music, rather than recycling old tunes. Where it differed from later opéras comiques, however, was that it contained no spoken dialogue. In this, Dauvergne was following the example of Pergolesi's La serva padrona.

The short, catchy melodies which replaced the vaudevilles were known as ariettes and many opéras comiques in the late 18th century were styled comédies mêlées d'ariettes. Their librettists were often playwrights, skilled at keeping up with the latest trends in the theatre. Louis Anseaume, Michel-Jean Sedaine and Charles Simon Favart were among the most famous of these dramatists. Notable composers of opéras comiques in the 1750s and 1760s include Egidio Duni, Pierre-Alexandre Monsigny and François-André Danican Philidor. Duni, an Italian working at the francophile court of Parma, composed Le peintre amoureux de son modèle in 1757 with a libretto by Anseaume. Its success encouraged the composer to move to Paris permanently and he wrote 20 or so more works for the French stage. Monsigny collaborated with Sedaine in works which mixed comedy with a serious social and political element. Le roi et le fermier (1762) contains Enlightenment themes such as the virtues of the common people and the need for liberty and equality. Their biggest success, Le déserteur (1769), concerns the story of a soldier who has been condemned to death for deserting the army. Philidor's most famous opéra comique was Tom Jones (1765), based on Henry Fielding's 1749 novel of the same name. It is notable for its realistic characters and its many ensembles.

The most important and popular composer of opéra comique in the late 18th century was André Grétry. Grétry successfully blended Italian tunefulness with a careful setting of the French language. He was a versatile composer who expanded the range of opéra comique to cover a wide variety of subjects from the Oriental fairy tale Zémire et Azor (1772) to the musical satire of Le jugement de Midas (1778) and the domestic farce of L'amant jaloux (also 1778). His most famous work was the historical "rescue opera", Richard Coeur-de-lion (1784), which achieved international popularity, reaching London in 1786 and Boston in 1797.

Between 1724 and 1762 the Opéra-Comique theatre was located at the Foire Saint Germain. In 1762 the company was merged with the Comédie-Italienne and moved to the Hôtel de Bourgogne. In 1783 a new, larger home was created for it at the Théâtre Italien (later renamed the Salle Favart).

Revolution and the 19th century
The French Revolution brought many changes to musical life in Paris. In 1793, the name of the Comédie-Italienne was changed to the Opéra-Comique, but it no longer had a monopoly on performing operas with spoken dialogue and faced serious rivalry from the Théâtre Feydeau, which also produced works in the opéra comique style. Opéra comique generally became more dramatic and less comic and began to show the influence of musical Romanticism. The chief composers at the Opéra-Comique during the Revolutionary era were Étienne Méhul, Nicolas Dalayrac, Rodolphe Kreutzer and Henri-Montan Berton. Those at the Feydeau included Luigi Cherubini, Pierre Gaveaux, Jean-François Le Sueur and François Devienne. The works of Méhul (for example Stratonice, 1792; Ariodant, 1799), Cherubini (Lodoïska, 1791; Médée, 1797; Les Deux journées, 1800) and Le Sueur (La caverne, 1793) in particular show the influence of serious French opera, especially Gluck, and a willingness to take on previously taboo subjects (e.g. incest in Méhul's Mélidore et Phrosine, 1794; infanticide in Cherubini's famous Médée). Orchestration and harmony are more complex than in the music of the previous generation; attempts are made to reduce the amount of spoken dialogue, and unity is provided by techniques such as the "reminiscence motif" (recurring musical themes representing a character or idea).

In 1801 the Opéra-Comique and the Feydeau merged for financial reasons. The changing political climate – more stable under the rule of Napoleon – was reflected in musical fashion as comedy began to creep back into opéra-comique. The lighter new offerings of Boieldieu (such as Le calife de Bagdad, 1800) and Isouard (Cendrillon, 1810) were a great success. Parisian audiences of the time also loved Italian opera, visiting the Théâtre Italien to see opera buffa and works in the newly fashionable bel canto style, especially those by Rossini, whose fame was sweeping across Europe. Rossini's influence began to pervade French opéra comique. Its presence is felt in Boieldieu's greatest success, La dame blanche (1825) as well as later works by Auber (Fra Diavolo, 1830; Le domino noir, 1837), Ferdinand Hérold (Zampa, 1831), and Adolphe Adam (Le postillon de Lonjumeau, 1836).

title: Opéra comique


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Verney Lovett Cameron

Verney Lovett Cameron (1 July 1844 – 24 March 1894) was an English traveller in Central Africa and the first European to cross (1875) equatorial Africa from sea to sea.

Biography
He was born at Radipole, near Weymouth, Dorset, son of Rev Jonathan Lovett Cameron and Frances Sapte. He entered the Royal Navy in 1857, served in the Abyssinian campaign of 1868, and was employed for a considerable time in the suppression of the East African slave trade.

The experience thus obtained led to his being selected to command an expedition sent by the Royal Geographical Society in 1873, to assist Dr Livingstone. He was also instructed to make independent explorations, guided by Livingstone's advice. Soon after the departure of the expedition from Zanzibar, a caravan of about 80 led by Chuma and Susi were met bearing the dead body of the reverend doctor. Cameron's two European companions, Dr William Edward Dillon, surgeon in the Royal Navy, and Lieutenant Cecil Murphy of the Royal Artillery, turned back to join the task of returning Livingstone's body to the coast. Cameron continued his march and reached Ujiji, on Lake Tanganyika, in February 1874, where he found and sent to England Livingstone's papers.

Cameron spent some time determining the true form of the southern part of the lake, and solved the question of its outlet by the discovery of the Lukuga River. From Tanganyika he struck westward to Nyangwe, the Arab town on the Lualaba previously visited by Livingstone. This river Cameron rightly believed to be the main stream of the Congo, and he endeavoured to procure canoes to follow it down. In this he was unsuccessful, owing to his refusal to countenance slavery, and he, therefore, turned southwest. After tracing the Congo-Zambezi watershed for hundreds of miles he reached Bihe and finally arrived at the coast on 28 November 1875, being the first European to cross equatorial Africa from sea to sea. He was awarded the Royal Geographical Society's Founder's Medal in 1876.

His travels, which were published in 1877 under the title Across Africa, contain valuable suggestions for the opening up of the continent, including the utilization of the great lakes as a Cape to Cairo Road connection. In recognition of his work, he was promoted to the rank of Commander. The remainder of Cameron's life was chiefly devoted to projects for the commercial development of Africa, and to editing and writing. His last work was the editing of the personal adventure narrative of the Master Mariner James Choyce, who had sailed as a teenager in 1797 aboard a whaler to the Pacific Ocean. Choyce's narrative covering 26 years of seafaring life is one of the earliest works of an Englishman's experiences in South America.

Cameron in 1878–1879 visited the Euphrates valley in connection with a proposed railway to the Persian Gulf, and accompanied Sir Richard Burton in his West African journey of 1882. At the Gold Coast Cameron surveyed the Tarkwa region, and he was joint author with Burton of To the Gold Coast for Gold (1883). In the 1880s he published several books for boys emulating his sister-in-law Mrs. Lovett Cameron who wrote romantic fiction.

He was killed, near Leighton Buzzard, by a fall from horseback when returning from hunting in 1894. He had married Amy, the daughter of William Morris of Jamaica.

A second edition of Across Africa, with new matter and corrected maps, appeared in 1885. A summary of Cameron's great journey, from his own pen, appears in Dr Robert Brown's The Story of Africa, vol. II, pp. 266–279 (London, 1893).

Across Africa was republished in 2005.

Works

 * The Cruise of the "Black Prince" Privateer (1886)
 * In Savage Africa (1887)
 * To The Gold Coast for Gold: A Personal Narrative. Vol. I, II
 * Among The Turks(1890)

title: Verney Lovett Cameron


text:
Comanche Wars

The Comanche Wars were a series of armed conflicts fought between Comanche peoples and Spanish, Mexican, and American militaries and civilians in the United States and Mexico from as early as 1706 until at least the mid-1870s. The Comanche were the Native American inhabitants of a large area known as Comancheria, which stretched across much of the southern Great Plains from Colorado and Kansas in the north through Oklahoma, Texas, and eastern New Mexico and into the Mexican state of Chihuahua in the south. For more than 150 years, the Comanche were the dominant native tribe in the region, known as “the Lords of the Southern Plains”, though they also shared parts of Comancheria with the Wichita, Kiowa, and Kiowa Apache and, after 1840, the southern Cheyenne and Arapaho.

The value of the Comanche traditional homeland was recognized by European-American colonists seeking to settle the American frontier and quickly brought the two sides into conflict. The Comanche Wars began in 1706 with raids by Comanche warriors on the Spanish colonies of New Spain and continued until the last bands of Comanche surrendered to the United States Army in 1875, although a few Comanche continued to fight in later conflicts such as the Buffalo Hunters' War in 1876 and 1877. The Comanche were noted as fierce combatants who practiced an emphatic resistance to European-American influence and encroachment upon their lands.

Comanche power peaked in the 1840s when they conducted large-scale raids hundreds of miles into Mexico proper, while also warring against the Anglo-Americans and Tejanos who had settled in independent Texas. Their power declined as epidemics of cholera and smallpox caused thousands of Comanche deaths and as continuous pressure from the expanding population of the United States forced them to cede most of their tribal lands.

Iron Jacket
Iron Jacket was a Comanche chief and medicine man. The name “Iron Jacket” came from his tendency to wear a coat of mail into battle. Iron Jacket took part in the Antelope Hills Expedition of 1858, where he was ultimately killed at the Battle of Little Robe Creek. His son, Peta Nocona, became a chief himself.

Peta Nocona
Peta Nocona was the father of the last Comanche Chief Quanah Parker, as well as a Comanche Chief who played a crucial part in the Indian Wars. Peta Nocona led the full attack on Fort Parker where Cynthia Ann Parker was taken captive and later became his wife. Peta Nocona's place and date of death is still in dispute.

Quanah Parker

Quanah Parker was the last Comanche Chief and part of the Quahadi sect of the Comanche, who were highly respected by the other tribes. Quanah was never an official chief since the United States government appointed him to the position. Before he was a Comanche chief, Quanah Parker witnessed the peace negotiations of 1867 but refused to sign the accords.

Buffalo Hump
Buffalo Hump was a Comanche War Chief who led the Great Raid of 1840 after Texan officials killed Comanche delegates during the events that unfolded during the Council House Fight.

Mirabeau B. Lamar
Mirabeau Lamar was the second President of the Republic of Texas from 1838 to 1841, preceded by Sam Houston. Mirabeau Lamar had a harsher policy towards Native Americans in Texas and signed two bills which escalated tensions in the region. The first bill was signed on December 21, 1838, which formed an 840-man regiment to protect the Northern and Western Frontiers of Texas. An additional bill was passed on December 29, 1838, which added an additional 8 companies of mounted volunteers to serve 6 month deployments.

Santa Anna (Comanche war chief)
Santa Anna was a Comanche war chief who advocated for armed resistance against the Texas settlers, and became influential after the Council House Fight of 1840 in San Antonio. Santa Anna joined forces with Buffalo Hump and most likely took part in the Battle of Plum Creek and the Great Raid of 1840. Santa Anna was the first of his tribe to travel to Washington, D.C., and agreed to sign a treaty in May 1846, despite the continued hostilities. Santa Anna died from a cholera outbreak in 1849.

Fort Parker massacre (May 1836)
The Fort Parker massacre was a raid conducted by a coalition of tribes including the Comanches, Kiowas, Caddos and Wichitas. They attacked the fort killing five of the inhabitants and capturing Cynthia Ann Parker a nine-year old who later married the Comanche chief Peta Nocona, John Richard Parker the brother of Cynthia Ann Parker, Rachel Plummer a seventeen-year-old wife along with her son James Pratt Plummer, and lastly Elizabeth Duty Kellog who was later reunited with her sister Martha in 1836.

Council House Fight (March 1840)
The Council House Fight was a Peace delegation turned conflict between the Comanche delegates and the Texas officials on March 19, 1840. The conflict started over negotiations regarding Texan and Mexican captives that the Comanches were holding in order to gain back sections of Comancheria that Texas had claimed. The Council house fight ended with twelve of the Comanche Leaders killed inside the Council house as well as 23 others shot in San Antonio.

Battle of Plum Creek (August 1840)
The Battle of Plum Creek was a conflict in Lockhart, Texas that took place on August 12, 1840. It was an attack led by Chief Buffalo Hump who led a large force of 1,000 Comanche warriors against 200 Texas Rangers in response to the Council House Fight. The Battle Began as a raid where the Comanche party stole livestock and firearms which gradually turned into a gun fight. The results of the battle are still being debated since the Rangers reported 80 Comanches were killed but only 12 bodies were found The Comanches claimed to have killed 11 Texas Rangers.

Antelope Hills expedition (January–May 1858)
The Antelope Hills expedition was a campaign led by the federal 2nd Cavalry against the Comanche and Kiowa tribes in Comancheria. It started in January 1858 and ended in May of the same year. The cause for the expedition was due to Comanche raids into Texan territories. Peta Nocona and Iron Jacket led Comanche troops against the combined 220 forces of the 2nd cavalry, Tonkawa, Nadaco and Shawnee. Their expedition's purpose was to move the 2nd Cavalry from Oklahoma to Texas in order to better handle the raiding Comanches. For this reason the United States gained the aid of the Comanches' enemy tribes Tonkawa, Nadaco and Shawnee. The resulting battle concluded with 50 killed on the United States side and 76 killed and 16 captured on the Comanche side. The Antelope Hills Expedition further expanded into the Battle of Little Robe Creek.

Battle of Little Robe Creek
The 1858 Battle of Little Robe Creek (Also known as the Battle of Antelope Hills) was a battle fought between the Comanches' allies of the Kiowa and the Apache against the Texas Rangers with their allies the Tonkawa, Caddo, Anadarko, Waco, Shawnee, Delaware, and Tahaucano. The Battle was the first in which the Texas Rangers successfully advanced into Comancheria. The United States rallied a force of 100 Texas Rangers and 113 allies where the Comanches rallied a force between the range of 200-600. The "battle" itself was actually three decisive engagements between the Comanches and the Texas Rangers; the first began in the morning of May 12 when the Rangers, led by General Ford launched a surprise attack on a Comanche camp. The Comanches were caught completely off guard and a massacre occurred. The second battle began when the Texas Rangers attempted to do the same to another nearby Comanche encampment. As they encroached on the camp, the Rangers were spotted by Comanche scouts. Though able to mount a concerted defense this time, the Comanche still suffered heavy casualties. It was not until the third and final battle of Little Robe creek that Comanche warriors were able to take an offensive stance against the Texas Rangers who then withdrew back into Texas proper. However, the campaign was costly for the Comanche forces: with 76 killed and over 60 warriors captured by the Texas Rangers, who by comparison lost only two killed and five wounded.

Battle of Pease River (December 1860)
The Battle of Pease River took place on December 18, 1860, in Foard County, Texas. This battle has become highly debated due to unreliable sources and exaggerated facts surrounding the event, but the event started in November 1860, most likely when a band of Comanche warriors, "struck farms, ranches, and outlying settlements in Parker, Young, Jack, and Palo Pinto counties west of Fort Worth." In these Comanche raids property was stolen and at least six people were killed. The citizens responded by pursuing the Comanches to a village on the Pease River, but because there were too many Comanches, the citizens had to wait for a larger force to arrive. Three units arrived, led by Lawrence Sullivan "Sul" Ross, Captain J.J. Cureton, and First Sergeant John W. Spangler. On December 19, 1860, Sul Ross led the attack on the Comanche village and according to Ross's report, "killed twelve of the Comanches and captured three: a woman who turned out to be Cynthia Ann Parker, her daughter Topsannah (Prairie Flower), and a young boy whom Ross brought to Waco and named Pease Ross...The whole incident lasted twenty minutes-thirty at the most."

First Battle of Adobe Walls (November 1864)
The First Battle of Adobe Walls was a battle fought against the United States Army and the Comanche Allies of Kiowa, and the Plains Apaches. The battle began when Kit Carson attacked a Kiowa town In response the Kiowa and Comanches launched a counterattack of over 1,000 men. The battle was long and drawn out almost to the point of the United States army running out of ammunition.

Red River War (June- September 1874)
In 1874 what came to be known as the Red River War (or Buffalo War) began. With the total population of the Comanche tribe reduced to only around 3,000 in total, divisions began to appear within the tribe. About two-thirds of the remaining Comanche now resided on the reservation, often labeled the “tamed Comanche” or “broken Comanche”. About 1,000 Comanche however continuing to roam the plains. Most of these Comanche would be considered civilians with only about 300 being actual warriors. The unsettled Comanche joined forces with warriors from likeminded factions of Kiowa, Kiowa Apache, and Southern Cheyenne and gathered together in the North Texas panhandle near the four major forks of Red River. The federal government responded by sending forty-six companies of soldiers, the largest force ever deployed against Native Americans by the U.S., under the command of General Mackenzie. The majority of the Red River War was conducted in guerrilla warfare and search-and-destroy tactics. The conflict ended with the Battle of Palo Duro Canyon, when General Mackenzie was able to conduct a surprise attack on the Comanche settlement. This led to the destruction of most of the Comanche’s resources and the seizure of 1,424 horses.

title: Comanche Wars


text:
User talk:Invisio

Welcome to the Wikipedia
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Feel free to contact me personally with any questions you might have. The Village pump is also a good place to go for quick answers to general questions. You can sign your name by typing 4 tildes, like this: ~.

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[[User:Sam Spade|Sam Spade Wants you to vote!]] 17:55, 6 Dec 2004 (UTC)

title: User talk:Invisio


text:
PNS Tariq (D-181)

PNS Tariq (DDG-181) was the lead ship of the Tariq-class destroyers in the Surface Command of the Pakistan Navy that served in the military service from 1993 until 2023. Prior to being commissioned in the Pakistan Navy, she served in the Royal Navy, as general purpose frigate HMS Ambuscade (F172).

Designed and constructed by Yarrow Shipbuilders, Ltd. at Glasgow, Scotland, in 1975, she underwent an extensive modernization and mid-life upgrade program by the KSEW Ltd. at the Naval Base Karachi in 1998–2002.

Tariq was decommissioned on 6 August 2023, alongside plans to return her to the United Kingdom for conversion to a museum ship.

Acquisition, construction, and modernization
Before commissioning in the Pakistan Navy, she served in the Royal Navy as HMS Ambuscade (F172), saw active military operations during the United Kingdom's Falklands War with Argentina in 1980s. She was lead ship based on the Type 21/Amazon design and was constructed by the Yarrow Shipbuilders, Ltd. in Glasgow in Scotland in 1973–75.

After the successful negotiations took place between Pakistan and the United Kingdom to procure the entire fleet of Type 21/Amazon frigates, she was decommissioned by the Royal Navy and a contingent of Pakistan Navy's personnel under Commander Muhammad Anwar arrived to receive training of her operations. She was commissioned in the services of Pakistan Navy on 28 July 1993 at the Port of Plymouth in England, reporting to its Naval Base Karachi on 18 November 1993.

She was named after Tariq ibn Ziyad, the commander who led the Umayyad conquest of Visigothic Hispania in 711–718 A.D. She was sponsored by the Benazir Bhutto, who as a chief guest and then-Prime Minister serving at that time.

The Royal Navy did not transfer either the Exocet and Seacat missiles, which were removed prior to arriving at Karachi but the Westland Lynx helicopters remained with the ship. The modernization of the ship was performed by KSEW Ltd which later installed the Phalanx system in place of the Seacat missiles as well as the Mk. 36 SRBOC launchers and 20 mm and 30 mm guns were fitted.

Deployment
Her wartime performance included in deployments in patrolling off the Gulf of Aden, Gulf of Oman, Persian Gulf, Arabian Sea as well as deploying in the Mediterranean Sea when she was part of the multinational military exercise with the U.S. Navy in 2005.

After the Indian Ocean tsunami in 2004, Tariq was deployed on a search-and-rescue mission to the Maldives, where she rescued 377 tourists.

Decommmissioning and disposal
On 6 August 2023, after 30 years service, Tariq was decommissioned in the presence of the Minister of Foreign Affairs, Bilawal Bhutto Zardari, son of the ship's original sponsor, Benazir Bhutto.

The Pakistan Navy has responded positively to proposals to return the Falklands veteran to the UK to become a museum ship near her birthplace on the River Clyde, at Glasgow or Greenock.

title: PNS Tariq (D-181)


text:
FM- and TV-mast Kosztowy

The FM and TV mast Katowice / Kosztowy (RTCN Katowice / Kosztowy) is a 358,7 metre tall guyed mast for FM and TV situated at Mysłowice - near Kosztowy, Poland. It replaced the TVP Katowice Mast which was dismantled in the 1970s.

The TVP Katowice Mast which it replaced was a 225-metre-high guyed steel framework mast with a triangular cross-section near Katowice, Poland. It was not the transmission site for the medium-wave frequency 1080 kHz. This frequency is transmitted by the transmitter Koszęcin.

The FM and TV mast Katowice / Kosztowy is since the collapse of the Warsaw radio mast the tallest structure in Poland. It was inaugurated on June 23, 1976. Originally its height was 269 metres. In 1987 it was converted to its actual value.

title: FM- and TV-mast Kosztowy


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Line 13 (Beijing Subway)

Line 13 of the Beijing Subway is a metro line that serves the northern suburbs of Beijing. On a map, Line 13's route is shaped like an inverted U that arcs north of the city and connects residential suburbs in Haidian, Changping, and Chaoyang Districts with the 2nd Ring Road and Line 2 at Xizhimen and Dongzhimen. With the exception of and a tunnel between Xi'erqi and Longze, all of Line 13's tracks and stations are located on the surface or elevated above ground. The line is 40.85 km and 16 of its 17 stations are on the surface. Line 13's color is yellow. During rush hour, the section between Xizhimen and Wudaokou Stations was reported in 2013 to be the second most congested section in the Beijing subway network, operating at 130% capacity.

Fare
There is a starting fare of RMB(¥) 3.00 that increases according to the distance, a fare scheme introduced in December 2014.

Regular subway users can use a Yikatong card, which offers even cheaper journeys, as well as mobile phone apps, which deploy payments via a QR code.

Hours of operation
The first trains depart from and  at 5:35am. The last trains to go the full-distance and reach the other terminus depart from Xizhimen and Dongzhimen at 10:42pm. In addition, Line 13 offers later night trains from either terminus that travel half of the full route. The last train to leave Xizhimen, departs at 11:45pm and ends its journey at Huilongguan at 12:09am. The last train to leave Dongzhimen, departs at 11:45pm and ends its journey at Huoying at 12:09am. For the official timetable, see. The frequency of trains on Line 13 varies from 3.5 minutes per train during the morning rush hour (6:20am – 9:40am) to 5 minutes per train during the evening rush hour (4:40pm – 8:40pm) to 10-11.5 minutes per train after 10:50pm. For a full listing of train frequency, see.

Route
Line 13's route is shaped like a horseshoe over northern Beijing. From in Xicheng District, Line 13 heads north, running alongside the Beijing-Baotou Railway into Haidian. After three stops in the bustling university district --, (transfer to Line 10), and —Line 13 leaves the 5th Ring Road and enters the suburbs of northern Haidian. At, Line 13 meets the Changping Line, and turns east, following the southern edge of Changping District for three stops (, , and ), before turning to the southeast. It enters Chaoyang District at (transfer to Line 5) and curls southwest after  onto the Beijing-Chengde Expressway. At, Line 13 intersects with Line 15. After entering the 3rd Ring Road at, the line runs straight south, along the remnants of the eastern earthen wall to Liufang. Then, Line 13 goes underground to in Dongcheng District where transfers are available to Line 2 and the Capital Airport Express.

History
Line 13 was opened in two sections: The western section between Xizhimen and Huoying was opened on September 28, 2002; the eastern section from Huoying to Dongzhimen was opened on January 28, 2003. Despite being numbered 13, the line was only the third subway line to enter into operation as lines 3 to 12 were still under planning at line 13's opening. It was the first Beijing Subway line to adopt Yikatong, the electronic farecard, at the end of 2003.

Future Development
On November 22, 2018, the Beijing Municipal Commission of Planning and Natural Resources began the 30-day public consultation of a plan to split Line 13 into two lines, temporarily named Line 13A and Line 13B. According to the plan, the existing Line 13 will be split between Xi'erqi station and Huilongguan station, to form two L-shaped lines intersecting in the north of the city. Passengers can use a cross-platform interchange between Line 13A and Line 13B at a new station in the west of the Jingzang Expressway.

Line 13A

Line 13A has a total length of 31.3 km with 18 stations, including 19.54 km of new line and 13 new stations. The line will be built to support expanded 8-car Type B trains.

Line 13B
Line 13B has a total length of 32.2 km with 15 stations, including 9.0 km of new line and 6 new stations. The line will continue to use 6-car Type B trains.

title: Line 13 (Beijing Subway)


text:
User:Nesnad

Hello. こんにちは。

 * I enjoy wikipedia and the concept.

 Some troll or sloth defaced my page. Please use my talk page for any comments regarding your love of pop bands or other silly things. Don't write on my face.

title: User:Nesnad


text:
Universities and Colleges Christian Fellowship

Universities and Colleges Christian Fellowship (UCCF; also UCCF: The Christian Unions) is a UK-based charity that was founded in 1928 as the Inter-Varsity Fellowship of Evangelical Unions. The UCCF endorses a conservative evangelical form of Christian theology.

UCCF's dual aims are:
 * 1) To advance the evangelical Christian faith amongst students, graduates and former members of universities; and
 * 2) To promote biblical scholarship and research.

To achieve its aims, UCCF undertakes three main areas of activity:
 * 1) Encouraging and supporting leaders of affiliated Christian Unions (CUs) throughout the UK to engage in evangelism and help Christian students grow in their faith.
 * 2) Publishing and distributing a wide range of Christian resources through its Inter-Varsity Press (IVP) subsidiary, based in Nottingham (not to be confused with the US-based InterVarsity Press).
 * 3) Supporting biblical research, mostly at postgraduate level.

The Christian Unions provide opportunities for fellowship, bible study and evangelism, with nearly 40,000 students attending outreach events each year.

History
The Universities and Colleges Christian Fellowship was formally established in 1928 as the Inter Varsity Fellowship, having emerged informally as a body influenced by the Cambridge Inter-Collegiate Christian Union earlier in the 1920s. CICCU had split from the broader Student Christian Movement (SCM) in 1910, following tensions between the two throughout the first decade of the 1900s. With a stronger conservative and evangelical presence than other Christian Unions, CICCU disagreed with SCM's move towards interdenominationalism and modernism (including the endorsement of newly emerging methods of Biblical criticism) and wanted a greater emphasis to be put on evangelism. An attempted reconciliation between the two groups in 1919 was ultimately unsuccessful, owing to CICCU's insistence on the centrality of the atonement for Christian faith, which SCM would not agree to. Evangelical students in the Oxford Inter-Collegiate Christian Union subsequently seceded from the SCM and, following a two-year reaffiliation, permanently left the SCM in 1927.

From 1919, under the influence of Norman Grubb, conservative evangelical students from UK universities began meeting at an annual conference in London. The first meeting produced a declaration critical of the Student Christian Movement, in particular criticizing its basis of faith for not mentioning the divinity of Christ and omitting any mention of sin, forgiveness, and salvation. In 1922, at the fourth annual meeting, it was decided to formally make the conference an annual event, as well as to appoint an executive committee and draft a constitution. The constitution of the Inter-Varsity Conference, which was accepted in 1923, included the group's doctrinal basis. The 1923 doctrinal basis included the "divine inspiration and infallibility of Scripture", the "universal sinfulness and guilt of human nature", and the "redemption from guilt, penalty and power of sin only through the sacrificial death... of Jesus Christ". Anyone who wanted to hold an official position in the running of the conferences had to sign the basis of faith, a requirement was created for prospective speakers to hold views in accordance with the basis, and the conference was prohibited from undertaking joint activities with groups that did not doctrinally align with the conference.

By 1928, the Inter-Varsity Conference became a permanent fellowship of evangelical Christian Unions and rival organisation to the SCM. After becoming the secretary of the Inter-Varsity Conference in 1924, King's College alumnus Douglas Johnson was chosen as the first and founding General Secretary of the Inter-Varsity Fellowship of Evangelical Unions by delegates of the 1928 conference. He remained in this role until 1964.

In 1947 the Inter-Varsity Fellowship became a founding member of the International Fellowship of Evangelical Students (IFES). The movement developed out of links that had been established between the IVF and the Norwegian network of Christian Unions, the Norges Kristelige Studentlag. From 1934, regular international conferences took place between evangelicals connected to universities in Europe, North America, South Africa, and Australia; in 1947 the IFES was formally established. In 1997, UCCF-affiliated Christian Unions at universities on the island of Ireland formed an independent movement called IFES Ireland (later renamed Christian Unions Ireland).

Owing to the increasing number of IVF-affiliated Christian Unions in non-university colleges, the Inter-Varsity Fellowship changed its name to the Universities and Colleges Christian Fellowship in 1974.

Until 2007 UCCF continued to act as the umbrella organization for Christian Unions in institutions within both the higher education and further education sectors. In that year, UCCF, in co-operation with Scripture Union, launched Festive, an independent initiative focused on supporting Christian Union groups in further education and sixth form colleges.

Key staff

 * Douglas Johnson, Secretary, 1928–64
 * Oliver R. Barclay, General Secretary, 1964–80
 * Robin Wells, General Secretary, 1980–92
 * Richard Cunningham, Director, 2004–

Research
UCCF supports biblical research through Tyndale House, Cambridge, which opened in 1945 and became independent in 2015.

From the late 1980s and into this century, support for those involved in Christian ethics was provided through the Whitefield Institute, Oxford, founded by E. David Cook. In 2006, this was reconstituted to become the Kirby Laing Institute for Christian Ethics, now the Kirby Laing Centre for Public Theology.

Theology
UCCF endorses a conservative evangelical form of Christian theology. Its doctrinal basis reflects typical elements of conservative evangelicalism, such as Biblical infallibility, the universal sinfulness of all humans, and penal substitution. Individual Christian Unions must subscribe to UCCF's doctrinal basis in order to be affiliated with them, and anyone who occupies a leadership position (including student executive committee members) or speaks at a Christian Union event must also sign to affirm their agreement.

The explicitly conservative evangelicalism of UCCF's doctrinal basis has led some to criticise the exclusivity of UCCF's theology. Biblical infallibility, the view that the Bible is completely true and sufficient for Christian belief and practice, is rejected by many Christian denominations. For example, the Catholic Church teaches that the Bible should be read in light of authoritative church tradition, while Anglicans and Methodists ascribe authority to tradition, reason and experience, and Pentecostals read the Bible in light of a community inspired by the Holy Spirit. The doctrine of penal substitution is likewise rejected by many non-evangelical Christians. In some cases, UCCF's evangelical theology has led to Christian Unions having difficult relationships with chaplaincies and/or student unions. It is also a substantial and persistent difference between UCCF and SCM (which is committed to ecumenism, including co-operation with CUs).

Demographics and organisation
According to a 2013 research paper, there are approximately 200 UCCF-affiliated Christian Unions in the UK, with a total membership of around 10,000. UCCF members thus accounted for just over 1% of the total Christian student population in the UK (800,000). In the same survey, 10% of Christian students (over 82,000) reported engaging with Christian Union activities during term time.

UCCF employs about 80 staff, and has a further 80 or so volunteer "Relay Workers" on a one-year training programme. Many of these staff and volunteers are graduates who were involved in the CU as undergraduates. They support the student Christian Unions with training, advice and materials. According to a 2006 Ekklesia report, the majority (>65%) of UCCF's funding comes through donations by individuals. A further 10% of its funding is from donations by churches, while the rest is made up of contributions made by individual Christian Unions groups and support from charitable trusts.


text: User talk:194.213.41.11

title: User talk:194.213.41.11


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CPLEX

IBM ILOG CPLEX Optimization Studio (often informally referred to simply as CPLEX) is an optimization software package.

History
The CPLEX Optimizer was named for the simplex method implemented in the C programming language, although today it also supports other types of mathematical optimization and offers interfaces other than C. It was originally developed by Robert E. Bixby and sold commercially from 1988 by CPLEX Optimization Inc. This was acquired by ILOG in 1997 and ILOG was subsequently acquired by IBM in January 2009. CPLEX continues to be actively developed by IBM.

Features
The IBM ILOG CPLEX Optimizer solves integer programming problems, very large linear programming problems using either primal or dual variants of the simplex method or the barrier interior point method, convex and non-convex quadratic programming problems, and convex quadratically constrained problems (solved via second-order cone programming, or SOCP).

The CPLEX Optimizer has a modeling layer called Concert that provides interfaces to the C++, C#, and Java languages. There is a Python language interface based on the C interface. Finally, a stand-alone Interactive Optimizer executable is provided for debugging and other purposes.

The CPLEX Optimizer is accessible through independent modeling systems such as AIMMS, AMPL, GAMS, OptimJ and TOMLAB. In addition to that AMPL provides an interface to the CPLEX CP Optimizer.

The full IBM ILOG CPLEX Optimization Studio consists of the CPLEX Optimizer for mathematical programming, the CP Optimizer for constraint programming, the Optimization Programming Language (OPL), and a tightly integrated IDE.

Release history
Prior to IBM acquiring ILOG, the CPLEX team published a release history of CPLEX.

title: CPLEX


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Perihelion Software

Perihelion Software Limited was a United Kingdom company founded in 1986 by Dr. Tim King along with a number of colleagues who had all worked together at MetaComCo on AmigaOS and written compilers for both the Amiga and the Atari ST.

Perihelion Software produced an operating system for the INMOS Transputer called HeliOS. This was a system that looked like Unix but which could pass messages to processes running on either the same processor or another one. This was used in the Atari Transputer Workstation, among other places.

Later HeliOS was ported to other processors including the ARM architecture.

Perihelion Software also produced an in-memory database system called Polyhedra. The group responsible for this product was set up as a subsidiary, Perihelion Technology Limited (PTL), which did a management buyout in 1994. PTL later changed its name to Polyhedra plc in 1995, and in 2001 was acquired by a Swedish company called ENEA.

title: Perihelion Software


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Geosiris

Geosiris is a genus in the flowering plant family Iridaceae, first described in 1894. It was thought for many years to contain only one species, Geosiris aphylla, endemic to Madagascar. But then in 2010, a second species was described, Geosiris albiflora, from Mayotte Island in the Indian Ocean northwest of Madagascar. In 2017, a third species was found in Queensland, Australia, Geosiris australiensis.

Geosiris aphylla is sometimes called the "earth-iris." It is a small myco-heterotroph lacking chlorophyll and obtaining its nutrients from fungi in the soil. The genus name is derived from the Greek words geos, meaning "earth", and iris, referring to the Iris family of plants.

Its rhizomes are slender and scaly, and stems are simple or branched. The leaves are alternate, but having no use, are reduced and scale-like. The flowers are light purple.

In 1939, F. P. Jonker assigned Geosiris to its own family Geosiridaceae in Orchidales, and this was adopted in the Cronquist system, with a note that the family was closely related to Iridaceae or Burmanniaceae. The Angiosperm Phylogeny Group has since subsumed the family into Iridaceae; it is currently placed in the monotypic subfamily Geosiridoideae.

title: Geosiris


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Liebeslieder, Op. 114 (Strauss)

Liebeslieder  op. 114 is a waltz by Johann Strauss II written in 1852 (not to be confused with Brahms's similarly titled Liebeslieder Walzer and Neue Liebeslieder). At the time it was conceived, the waltz was titled 'Liebesgedichte' or "Love Poems" and during its first performance, it was even announced as 'Liebesständchen' or "Love Serenade". The first performance was at the famed Vienna Volksgarten on 18 June 1852 under the composer's direction.

'Liebeslieder' stands among the master works of the Strauss Jr., who had, since 1849 an enduringly difficult time convincing the Viennese that his works deserve the attention it sought. The fierce and uncompromising Viennese critic Eduard Hanslick was even captivated by this waltz by writing in the journal "Wiener Zeitung" the following extract "Those bad-tempered old-fashioned people, whose narrow-mindedness goes far as to call today's dance music contemptible should be serenaded with ashaming generosity by the 'Liebeslieder' of the young Johann Strauss."

In essence, the waltz is a love serenade of sorts in 3/4 time. The waltz starts quietly with pizzicato on the strings section of the orchestra before a full-bodied 'forte' signals the beginning of the waltz sections. The first theme is that of a yearning feeling, before accelerating into a strong melody. The mood of the rest of the piece alternates between lushly romantic moods as well as light-heartedness, with the flute gently serenading the waltz sections 4 and 5. The piece ends dramatically, with a sense of anticipation, on a timpani drumroll and brass flourish.

The waltz also features many arrangements with a string orchestra as well as a quintet of strings. Curiously, many of these arrangements are labelled as 'Music of the Old Vienna' when played with such an arrangement, as it could be possible that Strauss' melodies in this waltz invoke the feeling of the romance of the Old Vienna.

Trivia

 * "The Liebeslieder Singers" is the name of the Chorus in Stephen Sondheim and Hugh Wheeler's musical A Little Night Music.

title: Liebeslieder, Op. 114 (Strauss)


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Mark Rolston

Mark Rolston (born December 7, 1956) is an American character actor, known for his supporting roles in such films as Aliens, Lethal Weapon 2, Prancer, The Shawshank Redemption, Rush Hour, The Departed, and the Saw film series, as well as Gordie Liman in The Shield (2003).

Career
Rolston played PFC M. Drake in Aliens (1986), Hans in Lethal Weapon 2 (1989), Herb in Prancer (1989), Stef in RoboCop 2 (1990), Bogs Diamond in The Shawshank Redemption (1994), J. Scar in Eraser (1996), Chief Dennis Wilson in Daylight (1996), Wayne Bryce in Hard Rain (1998), and Special Agent Warren Russ in Rush Hour (1998).

Rolston acted in Martin Scorsese's Academy Award winning 2006 film The Departed and the television horror film Backwoods. Many of Rolston's screen roles are villains due to his well-known icy stare. He also co-starred in 2008's Saw V and 2009's Saw VI. In 1994, he portrayed convicted killer "Karl Mueller" in the Babylon 5 episode "The Quality of Mercy", as well as "Richard Odin", leader of a vegetarian cult in an episode of The X-Files titled "Red Museum". In 2004, Rolston would guest star in two episodes of the critically acclaimed 24. He appeared in a minor role in The CW series Supernatural during the fourth season as the demon Alastair. He also appeared as Sheriff Hall in the Criminal Minds episode, "Blood Hungry".

Rolston has also voiced several Marvel and DC characters, voicing Firefly in The New Batman Adventures and Justice League (he was originally considered to voice the supervillain in Batman: The Animated Series in 1992, although the character was deemed unsuitable for the series and ultimately dropped). He voiced Lex Luthor in the animated series Young Justice, Deathstroke in Batman: Arkham Origins and Batman: Arkham Knight, as well as Norman Osborn in the Spider-Man Insomniac Games.

Personal life
Rolston was born in Baltimore, Maryland, the son of Evelyn Beverly (née Sturm) and Thomas George Rolston, who was a computer programmer.

title: Mark Rolston


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Katharina Dalton

Katharina Dalton  (11 November 1916 – 17 September 2004) was a British physician and pioneer in the research of premenstrual stress syndrome (PMS), coining the term, treating many women and testifying as an expert witness in influential court cases.

Background
Katharina Dorothea Kuipers was born in London on 11 November 1916 to parents Anna Knoester and Johannes Kuipers. Johannes Kuipers, a merchant and freemason, died when Dalton was young. Despite her family's financial troubles, Dalton attended the Royal Masonic School for Girls in London. As she grew, she wanted to be a doctor and, after winning a scholarship to the London Foot Hospital, first trained to be a chiropodist.

Dalton married her first husband, Wilfred Thompson, in 1939, but he died in World War II, not long after their son was born. Dalton then decided to change medical speciality, and obtained a medical degree at the Royal Free Hospital. Before graduating, she married Thomas Dalton, with whom she had three more children. Following the death of her husband Thomas in 1992, Katharina retired shortly after in 2000. She lived the rest of her days in Hereford and Poole, England and ultimately died on 17 September 2004.

Accomplishments
Dr. Dalton became involved in the study of PMS in 1948, when, as a pregnant 32-year-old medical student, she realized her monthly migraine headaches had disappeared. Consulting with endocrinologist Dr. Raymond Greene, she concluded that the headaches could be attributed to a deficiency in the hormone progesterone, which drops before menstruation but soars during pregnancy. After further clinical study, Dalton and Greene published the theory in British medical journals in 1953 — first using the term "premenstrual syndrome" or PMS.

Dalton treated numerous women after setting up her own practice and concluded that PMS was a cyclical hormonal illness occurring in the 14 days following ovulation, with the most severe symptoms evident during the final four days before menstruation. In direct conflict with the views of many of her male colleagues, Dalton said the symptoms were more physical than psychological and included migraine headaches, asthma, epilepsy, skin lesions, irritability, fatigue, and depression.

In addition to her patients, she studied teenage schoolgirls, the mothers of abused children and women confined to prison for serious crimes, including murder. For example, she testified as an expert witness at the Old Bailey in the trial of Nicola Owen, who had burnt her parents' house down. Her research showed that during times of severe PMS, students' academic performance dipped and women were more likely to abuse their children or commit crimes. From historic anecdotes, she even concluded that Queen Victoria suffered from PMS, as indicated by reports of her monthly screaming and throwing objects at her husband, Prince Albert. She is largely credited with developing the use of menstrual charts for the diagnosis of the disorder, and argued that the timing of PMS in women was associated with higher rates of suicide attempts, alcohol abuse and violent crimes.

PMS, Dalton argued, was brought on primarily by deficiencies of progesterone and could be alleviated with hormone therapy. She also believed that the hormone could be used to ease postnatal depression. But today most experts disagree with those findings and instead rely on selective serotonin reuptake inhibitors (SSRI) and other medications for the treatment of PMS.

In her later works, Dalton helped demonstrate that depression and other disorders could be aggravated by PMS, particularly around the last few days of the menstrual cycle or the first days of menstruation. Dalton eventually became the first female president of the general practice section within the Royal Society of Medicine.

Another observation made by Dalton was that some symptoms of PMS, such as hypertension, edema, and albumin in the urine, were predictors of toxaemia during pregnancy. Patients were administered an initial dose of progesterone during early symptoms and given continuous treatment if symptoms were still present. Using progesterone in trials in maternity hospitals, the incidence rate of toxemia dropped from 9 percent to 1 percent.

Dalton refused use of progestins (synthetic progestogens) in treatment as she believed they were the cause of side effects. She preferred bio-identical, or natural progesterone. In addition, Dalton only supported the use of natural progesterone as she claims that only natural progesterone fit progesterone receptors. Most of her treatments used generous doses of progesterone as she believed that there was no unsafe dose, with 400 milligrams via suppository being the minimum dose. Other positive effects of progesterone include increased hair growth and treatment of brain trauma.

After her work on PMS, she turned to postpartum depression (PPD). The large drop in hormone levels after giving birth can cause new mothers to feel symptoms of tiredness, irritability, and depression, similar to PMS. According to Dalton, these symptoms are considered mild, whereas more severe symptoms can include anxiety as well as changes in personality. In addition, she states that approximately three in one thousand new mothers may experience more severe symptoms of PPD referred to as postpartum psychosis. Symptoms of this psychosis may include hallucinations, thoughts of suicide, and even thoughts of killing their newborn child. Dalton suggested using progesterone therapy to prevent this from happening, usually starting after the end of labour. Her proposed therapy was intended to help slow the speed at which the progesterone hormone naturally drops.

Katharina Dalton published many books including: The Menstrual Cycle (1969); Premenstrual Syndrome and Progesterone Therapy (1977); Once a Month: The Original Premenstrual Syndrome Handbook (1978), which became a best seller, and Depression after Childbirth: How to Recognize, Treat, and Prevent Postnatal Depression.

Personal life
After the death of her first husband, Dalton married Tom Dalton, who died in 1992. She had four children, Michael, Thomas, Wendy, and Maureen. Dalton also had five grandchildren, including the British MEP Daniel Dalton. On 17 September 2004, Dalton died in Poole at the age of 87.

title: Katharina Dalton


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Supertrace

In the theory of superalgebras, if A is a commutative superalgebra, V is a free right A-supermodule and T is an endomorphism from V to itself, then the supertrace of T, str(T) is defined by the following trace diagram:

 * [[Image:Trace.png]]

More concretely, if we write out T in block matrix form after the decomposition into even and odd subspaces as follows,

 * $$T=\begin{pmatrix}T_{00}&T_{01}\\T_{10}&T_{11}\end{pmatrix}$$

then the supertrace

 * str(T) = the ordinary trace of T00 − the ordinary trace of T11.

Let us show that the supertrace does not depend on a basis. Suppose e1, ..., ep are the even basis vectors and ep+1, ..., ep+q are the odd basis vectors. Then, the components of T, which are elements of A, are defined as

 * $$T(\mathbf{e}_j)=\mathbf{e}_i T^i_j.\,$$

The grading of Tij is the sum of the gradings of T, ei, ej mod 2.

A change of basis to e1', ..., ep', e(p+1)', ..., e(p+q)' is given by the supermatrix

 * $$\mathbf{e}_{i'}=\mathbf{e}_i A^i_{i'}$$

and the inverse supermatrix

 * $$\mathbf{e}_i=\mathbf{e}_{i'} (A^{-1})^{i'}_i,\,$$

where of course, AA−1 = A−1A = 1 (the identity).

We can now check explicitly that the supertrace is basis independent. In the case where T is even, we have

 * $$\operatorname{str}(A^{-1} T A)=(-1)^{|i'|} (A^{-1})^{i'}_j T^j_k A^k_{i'}=(-1)^{|i'|}(-1)^{(|i'|+|j|)(|i'|+|j|)}T^j_k A^k_{i'} (A^{-1})^{i'}_j=(-1)^{|j|} T^j_j

=\operatorname{str}(T).$$

In the case where T is odd, we have
 * $$\operatorname{str}(A^{-1} T A)=(-1)^{|i'|} (A^{-1})^{i'}_j T^j_k A^k_{i'}=(-1)^{|i'|}(-1)^{(1+|j|+|k|)(|i'|+|j|)}T^j_k (A^{-1})^{i'}_j A^k_{i'} =(-1)^{|j|} T^j_j

=\operatorname{str}(T).$$

The ordinary trace is not basis independent, so the appropriate trace to use in the Z2-graded setting is the supertrace.

The supertrace satisfies the property
 * $$\operatorname{str}(T_1 T_2) = (-1)^{|T_1||T_2|} \operatorname{str}(T_2 T_1)$$

for all T1, T2 in End(V). In particular, the supertrace of a supercommutator is zero.

In fact, one can define a supertrace more generally for any associative superalgebra E over a commutative superalgebra A as a linear map tr: E -> A which vanishes on supercommutators. Such a supertrace is not uniquely defined; it can always at least be modified by multiplication by an element of A.

Physics applications
In supersymmetric quantum field theories, in which the action integral is invariant under a set of symmetry transformations (known as supersymmetry transformations) whose algebras are superalgebras, the supertrace has a variety of applications. In such a context, the supertrace of the mass matrix for the theory can be written as a sum over spins of the traces of the mass matrices for particles of different spin:

 * $$\operatorname{str}[M^2]=\sum_s(-1)^{2s} (2s+1)\operatorname{tr}[m_s^2].$$

In anomaly-free theories where only renormalizable terms appear in the superpotential, the above supertrace can be shown to vanish, even when supersymmetry is spontaneously broken.

The contribution to the effective potential arising at one loop (sometimes referred to as the Coleman–Weinberg potential ) can also be written in terms of a supertrace. If $$M$$ is the mass matrix for a given theory, the one-loop potential can be written as

 * $$V_{eff}^{1-loop}=\dfrac{1}{64\pi^2}\operatorname{str}\bigg[M^4\ln\Big(\dfrac{M^2}{\Lambda^2}\Big)\bigg] =

\dfrac{1}{64\pi^2}\operatorname{tr}\bigg[m_{B}^4\ln\Big(\dfrac{m_{B}^2}{\Lambda^2}\Big)- m_{F}^4\ln\Big(\dfrac{m_{F}^2}{\Lambda^2}\Big)\bigg]$$

where $$m_B$$ and $$m_F$$ are the respective tree-level mass matrices for the separate bosonic and fermionic degrees of freedom in the theory and $$\Lambda$$ is a cutoff scale.

title: Supertrace


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Igor Gamow

Rustem Igor Gamow (November 4, 1935, in Georgetown, D.C. – April 15, 2021) was a microbiology professor at the University of Colorado and inventor. His best known inventions included the Gamow bag and the Shallow Underwater Breathing Apparatus. He was fired from CU in 2004 following sexual harassment and assault charges.

Early life and education
Rustem Igor Gamow was the son of Soviet émigré physicists George Gamow and Lyubov Vokhmintseva "Rho" Gamow. Finishing high school at age 17, he joined the National Ballet Company. He worked breaking horses, delivering packages by motorcycle, and teaching karate before enrolling at the University of Colorado in 1958, where his father taught. Igor Gamow received a B.A. and M.S. in biology, and a Ph.D. in biophysics, all at University of Colorado.

Research
Gamow worked on Phycomyces blakesleeanus during postdoctoral research under Max Delbrück at Caltech. At CU-Boulder, he did Phycomyces research for over twenty years, mainly on the avoidance and anemotropic responses, helical growth, and cell-wall mechanical properties. He also studied the infrared-detectors of the Boa constrictor.

An avid outdoorsman, Gamow developed a number of inventions for safety in outdoor activities. His first important one, patented in 1990, was the Gamow bag enabling mountain climbers to avoid altitude sickness by raising the surrounding pressure. Sir Edmund Hillary, the first expedition leader to summit Mount Everest, wrote him in congratulation. Another was the Shallow Underwater Breathing Apparatus ("SUBA"), a pressurized snorkel system permitting swimmers to breathe easily as deep as ten feet under water.

Igor Gamow also worked in bionics, on an orthopedic knee brace that stores energy within a spring from the hamstring and redirects it to the quadriceps.

Patents

 * — Hyperbaric chamber
 * — Hyperbaric chamber
 * — Underwater breathing apparatus
 * — Hyperbaric chamber closure means
 * — Shoe and foot prosthesis with a coupled spring system
 * — Hyperbaric chamber and exercise environment
 * — Hypobaric sleeping chamber
 * — In-line skate walking guard
 * — Shoe and foot prosthesis with bending beam spring structures
 * — Underwater breathing apparatus with pressurized snorkel
 * — Shoe and foot prosthesis with bending beam spring structures

Termination at CU
In 2002, a former assistant of Gamow's filed a lawsuit against the university alleging sexual harassment and sexual assault of seven women. After the lawsuit was filed, the university began to take steps to terminate Gamow. In 2004 the CU Board of Regents unanimously upheld the recommendation to dismiss Gamow for "moral turpitude". Gamow filed a lawsuit against CU in an attempt to be reinstated.

In May 2006, CU lost a lawsuit that had been filed by Gamow's former assistant and was ordered to pay her $285,000 plus attorney's fees.

In September 2011, Gamow released an open letter addressing some misconceptions about events leading to his termination from the University of Colorado.

title: Igor Gamow


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User:Wyatts/Draft article B

Failure Rate

From Wikipedia, the free encyclopedia.

Failure rate describes how frequently something fails. Failure rate, often denoted by the symbol $$ \lambda $$, is important in the fields of reliability theory and product warranties. The failure rate depends on the failure distribution, which describes the probability of failure prior to a specified time. Another way of expressing the failure rate is the mean time between failure (MTBF), which is the "average" time between failures. The failure rate is not always constant, so the hazard function is used to describe the instantaneous failure rate at any point in time. The bathtub curve, a particular form of the hazard function, is a typical representation of the failure rate of a system during its product life cycle.

Failure rate definitions
Failure rate can be defined as,

 * The total number of failures within an item population, divided by the total time expended by that population, during a particular measurement interval under stated conditions. (MacDiarmid, et al.)

Failure rate can also be defined mathematically as the probability that a failure per unit time occurs in a specified interval, which is often written in terms of the reliability function, $$R(t) \!$$, as,

 * $$\frac{R(t_1)-R(t_2)}{(t_2-t_1)R(t_1)} \!$$,

or,

 * $$\frac{R(t)-R(t+\triangle t)}{\triangle t \cdot R(t)} \!$$

where,

 * $$t_1 \!$$ and $$t_2 \!$$ are the beginning and ending of a specified interval of time, and

 * $$R(t)\!$$ is the reliability function, i.e. probability of no failure before time $$t \!$$.

Failure distributions
Failure rate depends on its failure distribution, $$F(t) \!$$, which is a cumulative distribution function that mathematically describes the probability of failure prior to time $$t \!$$,

 * $$P(\mathbf{t}\le t)=F(t), t\ge 0 \!$$.

The failure distribution function is the integral of the failure density function, $$f(x) \!$$,

 * $$F(t)=\int_{0}^{t} f(x)\, dx \!$$.

There are many failure distributions (see List of important probability distributions). A common failure distribution is the exponential failure distribution,

 * $$F(t)=\int_{0}^{t} \lambda e^{-\lambda x}\, dx = 1 - e^{-\lambda t} \!$$,

which is based on the exponential density function.

In this case, the parameter $$\! \lambda$$ in the exponential distribution is the failure rate.

Mean-time-between-failure (MTBF)
Main article Mean time between failure

A common use of the failure rate is to determine the mean-time-between-failure (MTBF), which may be thought of as the "average" time between failures. The MTBF is simply the recipricol of the failure rate,

 * $$MTBF=\frac{1}{\lambda} \!$$.

The MTBF is often denoted by the symbol, $$\! \theta$$, or,

 * $$MTBF=\theta \!$$.

Since failure rate and MTBF are simply recipricols, both notations are found in the literature depending on which notation is most convenient for the application.

The MTBF can be defined in terms of the expected value of the failure density function,

 * $$MTBF=E(t)=\int_{0}^{\infty} xf(x)\, dx \!$$

A common misconception about the MTBF is that it specifies the time (on average) when half of the items will fail. This is only true for certain symetrical distributions. In many cases, such as the non-symetrical exponential distribution, this is not true. For example, for an exponential failure distribution, the probability that an item will fail by the MTBF is approximately 0.63.

MTTF, mean-time-to-failure is sometimes used instead of MTBF in cases where a system is replaced after a failure, whereas MTBF denotes time between failures where the system is repaired.

There are many variations of MTBF, such as mean-time-between-system-abort (MTBSA) or mean-time-between-critical-failure (MTBCF). Such nomenclature is used when it is desirable to differentiate among types of failures. For example, in an automobile, the failure of the FM radio does not prevent the primary operation of vehicle, so that it may be desirable to differentiate the failure rates of critical versus non-critical failures.

Hazard function
One drawback of the MTBF is that it assumes that the failure rate is constant for all intervals. However, the failure rate of a system may vary with time, such that a single number does not accurately describe the failure rate during all intervals of time. For example, as an automobile grows older, the failure rate in its 5th year of service may be greater than its failure rate during its 1st year of service, so that it is not desirable to use the same failure rate to describe both of these intervals of time.

By calculating the failure rate for smaller and smaller intervals of time, $$\triangle t \! $$, the interval becomes infinitestimally small. This results in the hazard function, which is the instantaneous failure rate at any point in time,

 * $$h(t)=\lim_{\triangle t \to 0} \frac{R(t)-R(t+\triangle t)}{\triangle t \cdot R(t)}$$, or,

 * $$h(t)=\frac{f(t)}{R(t)} \!$$.

If the hazard function is constant, then the failure rate is the same for any equal period of time. This implies that failures occur with equal frequency during any equal period of time. The exponential failure distribution has a constant hazard rate.

For other distributions, such as the log-normal distribution, the hazard function is not constant, which means that the failure rate varies with time.

Bathtub curve
Main article Bathtub curve

The bathtub curve describes a particular form of the hazard function that comprises three parts:

 * The first part is a decreasing failure rate, known as early failures or infant mortality.
 * The second part is a constant failure rate, known as random failures.
 * The third part is an increasing failure rate, known as wearout failures.

The bathtub curve is often employed to represent the failure rate of a product during its lifecycle, namely, the product experiences early "infant mortality" failures when first introduced, then exhibits random failures with constant failure rate during its "useful life", and finally experiences "wear out" failures as the product exceeds its design lifetime.

The bathtub curve is often modeled by a piecewise set of three hazard functions,

 * $$h(t) = \begin{cases} c_0-c_1t+\lambda, & 0\le t \le c_0/c_1 \\ \lambda, & c_0/c_1 < t \le t_0 \\c_2(t-t_0)+\lambda, & t_0 < t \end{cases} \!$$

While the bathtub curve is useful, not every product or system follows a bathtub curve hazard function. ASQC paper

Failure rate data
Failure rate data can be obtained in several ways. The most common means are:
 * Historical data about the device or system under consideration.
 * Many organizations maintain internal databases of failure information on the devices or systems that they produce, which can be used to calculate failure rates for those devices or systems. For new devices or systems, the historical data for similar devices or systems can serve as a useful estimate.

 * Government and commercial failure rate data.
 * Handbooks of failure rate data for various components are available from government and commercial sources. MIL-HDBK-217, Reliability Prediction of Electronic Equipment, is a military standard that provides failure rate data for many military electronic components. Several failure rate data sources are available commercially that focus on commercial components, including some non-electronic components.

 * Testing.
 * The most accurate source of data is to test samples of the actual devices or systems in order to generate failure data. This is often prohibitively expensive or impractical, so that the previous data sources are often used instead.

Units
Failure rates can be expressed using any measure of time, but hours is the most common unit in practice. Other units, such as miles, revolutions, etc., can also be used in place of "time" units.

Failure rates are often expressed in engineering notation as failures per million, or $$10^{-6} \!$$, especially for individual components, since their failure rates are often very low.

Additivity
Under certain engineering assumptions, the failure rate for a complex system is simply the sum of the individual failure rates of its components, as long as the units are consistent, e.g. failures per million hours. This permits testing of individual components or subsystems, whose failure rates are then added to obtain the total system failure rate.

Example
A certain component is tested to estimate its failure rate. 10 components are tested until they either fail or reach 1000 hours, at which time the test is terminated for that component. The results are as follows:

Estimated failure rate is,

$$\frac{6 \mbox{ failures}}{7502 \mbox{ hrs}} = 0.0007998 \mbox{ failures/hr} = 799.8\mbox{ x }10^{-6} \mbox{ failures/hr} $$,

or 799.8 failures for every million hours of operation.

title: User:Wyatts/Draft article B


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Category:Oceanographers

Oceanographers direct or influence interdisciplinary oceanography research.

title: Category:Oceanographers