omniomni/omni-engineering huggingface dataset:
F11. F11 or F-11 may refer to:

Military
 F 11 Nyköping, a Swedish Air Force wing
 F-11 Tiger, a 1954 U.S. Navy jet fighter originally designated F11F
 F11C Goshawk, a 1932 U.S. Navy biplane fighter
 Hughes XF-11, a 1946 U.S. Army Air Forces reconnaissance aircraft prototype

Science and academia
 Trichlorofluoromethane, a refrigerant used before 1995
 Factor XI, a clotting agent found in blood

Sports
 F11 (classification), a classification in para-athletics

Technology
 , a function key on a computer keyboard (enters and exits fullscreen mode in many web browsers)
 Fujifilm FinePix F11, a digital camera model

Transportation
 Chery F11, a 2008 Chinese Chery Automobile model
 Fairchild F-11 Husky, a 1946 Canadian bush plane
 Falconar F11 Sporty, a Canadian amateur-built aircraft design
 Fokker F.11, a 1928 flying boat

Other uses
 Finger Eleven, a Canadian alternative rock band
 Forest Eleven, a group of rainforest countries

See also
 11F (disambiguation)
British Rail Class 376. The British Rail Class 376 Electrostar is a class of electric multiple unit passenger train that was manufactured by Bombardier Transportation at its Derby Litchurch Lane Works. It is part of the Electrostar family, which are the most common EMUs introduced since the privatisation of British Rail. The units were ordered by Connex South Eastern and introduced in 2004/2005 by South Eastern Trains to replace Class 465 and Class 466, which were transferred to Outer Suburban services to Kent to replace the Class 423 slam-door trains.

Design

It is a derivative of the Class 375 Electrostar specially designed for use on the high-volume metro routes running from Central London, and through Southeast London to Kent. The changes are mostly focused on increasing the trains’ capacity and decreasing station dwell times. The Class 376's doors are wider to allow more passengers to board at once, and are metro-style sliding pocket doors which are faster and more reliable than the Class 375's plug doors, although they do not close flush with the bodyside and hence are less aerodynamic and do not provide as much thermal insulation. The units have 2 sets of double doors per side in each carriage. Also, these trains do not have air conditioning, with hopper style windows available for ventilation. In order to provide more standing room, the trains also have fewer seats, more handrails, and no on-board toilets (South Eastern promised to provide additional facilities in their stations to compensate) and, as a consequence, these trains are limited to in-service journey times of 1 hour.

Class 376 units have five coaches, and unlike the Class 375, they have full-width cabs instead of gangways at the ends of the train; as a result, it is not possible to walk between two coupled Class 376 units. The cab front is also smooth and ‘step free’ to reduce the dangerous problem of train surfing in Southeast London.

Despite being numbered in the 300s, currently all Class 376 units can only operate on the DC third rail network. However, like most newer trains in the United Kingdom using third rail power, one carriage in each unit has a recess in its roof where a pantograph can be fitted, so as to allow for future conversion to overhead AC traction power and/or make the unit dual voltage.

Maintenance

All Class 376 trains are allocated to Slade Green Depot, but due to the high volume of work there, these trains are sent to Ramsgate EMUD for routine maintenance.

Fleet details

Accidents and incidents
A train formed by units 376 002 and 376 035 was one of eleven trains that stalled and became stranded in the Lewisham area on 2 March 2018. Passengers self-evacuated the train after conditions on board became intolerable due to lack of heating, toilets and communication. 

On 10 July 2018, 376 030 partially derailed at Grove Park depot.

See also 
 Bombardier Electrostar
 British Rail Class 378

References

External links

376
Bombardier Transportation multiple units
Train-related introductions in 2004
750 V DC multiple units
Oleoresin. Oleoresins are semi-solid extracts composed of resin and essential or fatty oil, obtained by evaporation of the solvents used for their production. The oleoresin of conifers is known as crude turpentine or gum turpentine, which consists of oil of turpentine and rosin.

Properties 
In contrast to essential oils obtained by steam distillation, oleoresins abound in heavier, less volatile and lipophilic compounds, such as resins, waxes, fats and fatty oils. Gummo-oleoresins (oleo-gum resins, gum resins) occur mostly as crude balsams and contain also water-soluble gums. Processing of oleoresins is conducted on a large scale, especially in China (400,000 tons per year in the 1990s), but the technology is too labor-intensive to be viable in countries with high labor costs, such as the US.

Oleoresins are prepared from spices, such as basil, capsicum (paprika), cardamom, celery seed, cinnamon bark, clove bud, fenugreek, fir balsam, ginger, jambu, labdanum, mace, marjoram, nutmeg, parsley, pepper (black/white), pimenta (allspice), rosemary, sage, savory (summer/winter), thyme, turmeric, vanilla, and West Indian bay leaves. The solvents used are nonaqueous and may be polar (alcohols) or nonpolar (hydrocarbons, carbon dioxide).

Oleoresins are similar to perfumery concretes, obtained especially from flowers, and to perfumery resinoids, which are prepared also from animal secretions.

Use 

Most oleoresins are used as flavors and perfumes, some are used medicinally (e. g., oleoresin of Cannabis). Oleoresin capsicum is commonly used as a basis for pepper sprays. There are also uses known in the manufacture of soaps of cosmetics, as well as coloring agents for foods.  A well-known pipe thread sealant, Rectorseal #5, is stated to have an "oleoresinous base".

References 

 
Flavors
Resins
Dimethyl sulfite. Dimethyl sulfite is a sulfite ester with the chemical formula (CH3O)2SO.

Dimethyl sulfite is used as an additive in some polymers to prevent oxidation.  It is also a potentially useful high energy battery electrolyte solvent.

Structure and conformation
The dimethyl sulfite molecule can adopt several conformations. The most stable is the GG conformer. Each C–O bond is gauche to the S=O bond, depicted below.

Preparation
Dimethyl sulfite is prepared from a 1:2 ratio of thionyl chloride and methanol. The reaction can be catalyzed by tertiary amine bases and likely proceeds via the chlorosulfinate (MeOS(O)Cl), this intermediate will exist only fleetingly in the presence of methanol and as such its decomposition to methyl chloride and sulfur dioxide (via the slower SNi mechanism) is not observed to any great extent.

See also
 Methyl methanesulfonate, chemical isomer
 Diethyl sulfite, a similar sulfite ester
 Dimethyl sulfoxide
 Dimethyl sulfate, a sulfate ester

References

External links
 WebBook page for C2H6SO3

Organosulfites
Methyl esters
SEAgel. SEAgel (Safe Emulsion Agar gel) is one of a class of high-tech foam materials known as aerogels. It is an excellent thermal insulator and among the least dense solids known. SEAgel was invented by Robert Morrison at the Lawrence Livermore National Laboratory in 1992. SEAgel is made of agar, a carbohydrate material that comes from kelp and red algae, and has a density of 200 mg/cm3.
SEAgel can be made lighter than air using hydrogen, causing it to float or hang in the air.  It insulates against temperature, noise, and electric current. SEAgel is also completely biodegradable, as it is made entirely of biological material and can even be eaten.

Initially, SEAgel starts out as a gelatin-like mixture of agar and water. After it is freeze-dried to remove the water, it is left as a honeycomb of dried agar filled with air, with cell sizes two to three micrometers (2-3 μm) in diameter.

SEAgel can have many different uses. Laboratory scientists use SEAgel as targets for x-ray laser experiments because it can be doped with other materials, such as selenium. In order to eliminate the volatile hydrodynamics that occur when a solid-density target explodes before it reaches the density required for lasing, scientists are trying to develop an x-ray laser target with a density that is less than the critical density of laser light (4×1021 electrons/cm3 for 0.53-μm light). SEAgel can help them achieve a more uniform plasma, which will ultimately improve the quality of the x-ray laser beam.

SEAgel could also be used as food packaging or the encapsulating material of timed-release medical pills, as it is safe to digest. SEAgel could also replace balsa wood, to insulate supertankers, and to provide sound damping in high-speed trains.

SEAgel was covered under U.S. patents 5,382,285 ("Biofoam") and 5,360,828 ("Biofoam II").

References

External links 
 Physics News Update — (Story #4), August 19, 1992 by Phillip F. Schewe and Ben Stein
 MadSci Network — Re: What exactly are SEAgels?

Aerogels
Brand name materials
Cessna 441 Conquest II. The Cessna 441 Conquest II is the first turboprop powered aircraft designed by Cessna and was meant to fill the gap between their jets and piston-engined aircraft. It was developed in November 1974, with the first aircraft delivered in September 1977. It is a pressurized, 8–9 passenger turbine development of the Cessna 404 Titan. The ICAO designator as used in flight plans is C441.

Development

The original design from 1972 for this aircraft was known as the Model 435 and was to be powered by Continental GTSIO-520X engines with three-bladed propellers. By 1975, the designed evolved into the turboprop-powered Model 441. It was certified by the FAA on August 19, 1977.  The high aspect ratio wings use bonded construction techniques.
Cessna renamed the Model 441 the Conquest II in 1983.
1984 models starting with constructor number 195 used lighter-weight, four-bladed McCauley propellers.  
A 441 with Pratt & Whitney Canada PT6A-112 turboprops was flown in 1986, but did not enter production. Cessna built 362 of the aircraft between 1977 and 1986.
A smaller aircraft was marketed as the Cessna 425 Conquest I, itself a turbine development of the Cessna 421.

In September 2007, Cessna limited the Conquest II to 22,500 hours of air time through a Supplemental Inspection Document. This makes it effectively mandatory for US air carriers but only advisory for private operators.

Performance 
The Cessna 441 cruises at  true airspeed while burning  of fuel per hour at flight level 290. The aircraft's maximum range is  at  TAS and /h at FL350.

With six to nine seats, its  basic operating weight (BOW) allows a  payload at full fuel, but MTOW can be increased by  with aftermarket modifications.

Upgrades 
Most 441s currently in service have been upgraded to TPE331-10 engines and four-bladed propellers (if not originally equipped). The -10 engine increases climb performance, service ceiling, and TBO, while four-blade propellers increase climb rate, cruise speed, and ground clearance, while reducing cabin noise.

Operators 

The Conquest II is operated by corporate owners, air charter operators and previously by the Royal Flying Doctor Service in Australia. Examples of the type have been exported to many countries including Austria, Australia, Canada, Ecuador, Finland, Germany, Iceland, Mexico, Norway, Peru, South Africa, Sweden and the United Kingdom. 

By May 2019, 290 aircraft remained in service, at a $.75-.9M value down from $1-1.9M in 2011.

Specifications (Conquest II)

See also

References

External links

 Airliners.net - Photographs
 Airliners.net - Cessna Conquest

441
1970s United States civil utility aircraft
Low-wing aircraft
Aircraft first flown in 1975
Twin-turboprop tractor aircraft
Aircraft with retractable tricycle landing gear
Rate of heat flow. The rate of heat flow is the amount of heat that is transferred per unit of time in some material, usually measured in watts (joules per second). Heat is the flow of thermal energy driven by thermal non-equilibrium, so the term 'heat flow' is a redundancy (i.e. a pleonasm). Heat must not be confused with stored thermal energy, and moving a hot object from one place to another must not be called heat transfer. However, it is common to say ‘heat flow’ to mean ‘heat content’.

The equation of heat flow is given by Fourier's law of heat conduction.

Rate of heat flow = - (heat transfer coefficient) * (area of the body) * (variation of the temperature) / (length of the material)

The formula for the rate of heat flow is:

where

  is the net heat (energy) transfer,
  is the time taken,
  is the difference in temperature between the cold and hot sides,
  is the thickness of the material conducting heat (distance between hot and cold sides),
  is the thermal conductivity of the material conducting heat, and
  is the surface area of the surface emitting heat.

If a piece of material whose cross-sectional area is  and thickness is  with a temperature difference  between its faces is observed, heat flows between the two faces in a direction perpendicular to the faces. The time rate of heat flow, , for small  and small , is proportional to . In the limit of infinitesimal thickness , with temperature difference , this becomes , where  is the time rate of heat flow through the area ,  is the temperature gradient across the material, and , the proportionality constant, is the thermal conductivity of the material. People often use , , or the Greek letter  to represent this constant. The minus sign is there because the rate of heat flow is always negative—heat flows from the side at higher temperature to the one at lower temperature, not the other way around.

See also

Heat transfer coefficient
Heat transfer
Thermal conduction
Thermal conductivity
 Heat flux
 Watt
 Flux

References

Thermodynamic properties
Heat flow
Srinivasan Keshav. Srinivasan Keshav  is a computer scientist who is currently the Robert Sansom Professor of Computer Science at the University of Cambridge.

Biography
After undergraduate studies at the Indian Institute of Technology, Delhi in 1986, he received his PhD in 1991 from the University of California, Berkeley, with a thesis entitled Congestion Control in Computer Networks. His advisor was Domenico Ferrari. He then joined the research staff at Bell Labs, where he also had visiting faculty positions at IIT Delhi and Columbia University. In 1996 he became an associate professor at Cornell University; he then left academia in 1999 to co-found Ensim Corporation. In 2003, he joined the faculty at the University of Waterloo, where he held a Canada Research Chair in Tetherless Computing from 2004 to 2014 and a Cisco Systems Chair in Smart Grid from 2012 to 2017.

He is the inventor, along with his students at the University of Waterloo, of KioskNet, a system for providing internet access in impoverished countries. He has been co-director of the Information Systems and Science for Energy (ISS4E) Laboratory at the University of Waterloo since 2010. At the University of Cambridge, Professor Keshav continues to work on research and teach in areas related to sustainable energy.

Academic works and affiliations
Keshav is the author of a textbook on computer networks, An Engineering Approach to Computer Networking. In 2012, he wrote Mathematical Foundations of Computer Networking.

Keshav was the Editor of Computer Communication Review from 2008 to 2013  and the Chair of ACM SIGCOMM from 2013 to 2017.

Honors and awards
David Sakrison Memorial Prize, UC Berkeley (1992)
Sloan Fellowship (1997-1999)
ACM Fellow (2012)
 "For contributions to computer communication networks and systems."
IEEE Fellow (2019)
IIT Delhi Distinguished Alumni Award (2019)
Fellow, Royal Society of Canada, 2019

References

External links
S. Keshav's home page
How to Read a Paper, three-pass method for reading research papers.

American computer scientists
Canadian computer scientists
Computer systems researchers
1965 births
Living people
University of California, Berkeley alumni
Cornell University faculty
Academic staff of the University of Waterloo
Canadian writers of Asian descent
Canadian technology writers
Canada Research Chairs
Fellows of Fitzwilliam College, Cambridge
IIT Delhi alumni
Indian emigrants to Canada
Meta-Chloroperoxybenzoic acid. meta-Chloroperoxybenzoic acid (mCPBA or mCPBA) is a peroxycarboxylic acid. It is a white solid often used widely as an oxidant in organic synthesis. mCPBA is often preferred to other peroxy acids because of its relative ease of handling.  mCPBA is a strong oxidizing agent that may cause fire upon contact with flammable material.

Preparation and purification
mCPBA can be prepared by reacting m-chlorobenzoyl chloride with a basic solution of hydrogen peroxide, followed by acidification.

It is sold commercially as a shelf-stable mixture that is less than 72% mCPBA, with the balance made up of m-chlorobenzoic acid (10%) and water. The peroxyacid can be purified by washing the commercial material with a  sodium hydroxide and potassium phosphate solution buffered at pH = 7.5. Peroxyacids are generally slightly less acidic than their carboxylic acid counterparts, so the acid impurity can be extracted if the pH is carefully controlled. The purified material is reasonably stable against decomposition if stored at low temperatures in a plastic container.

In reactions where the exact amount of mCPBA must be controlled, a sample can be titrated to determine the exact amount of active oxidant.

Reactions
The main areas of use are the conversion of ketones to esters (Baeyer-Villiger oxidation), epoxidation of alkenes (Prilezhaev reaction), conversion of silyl enol ethers to silyl α-hydroxy ketones (Rubottom oxidation), oxidation of sulfides to sulfoxides and sulfones, and oxidation of amines to produce amine oxides. The following scheme shows the epoxidation of cyclohexene with mCPBA.

The epoxidation mechanism is concerted: the cis or trans geometry of the alkene starting material is retained in the epoxide ring of the product.  The transition state of the Prilezhaev reaction is given below:

The geometry of the transition state, with the peracid bisecting the C-C double bond, allows the two primary frontier orbital interactions to occur: πC=C (HOMO) to σ*O-O (LUMO) and nO (HOMO, regarded as a filled p orbital on a sp2 hybridized oxygen) to π*C=C (LUMO), corresponding, in arrow-pushing terms, to formation of one C-O bond and cleavage of the O-O bond and formation of the other C-O bond and cleavage of the C=C π bond.

References

3-Chlorophenyl compounds
Organic peroxy acids
Reagents for organic chemistry
Hausmannite. Hausmannite is a complex oxide, or a mixed oxide, of manganese containing both di- and tri-valent manganese. Its chemical formula can be represented as , or more simply noted as , or , as commonly done for magnetite (), the corresponding iron oxide. It belongs to the spinel group and forms tetragonal crystals. Hausmannite is a brown to black metallic mineral with Mohs hardness of 5.5 and a specific gravity of 4.8.

The type locality is Oehrenstock (Öhrenstock), Ilmenau, Thuringian Forest, Thuringia, Germany, where it was first described in 1813. Locations include Batesville, Arkansas, US; Ilfeld, Germany; Langban, Sweden; and the Ural Mountains, Russia. High quality samples have been found in South Africa and Namibia where it is associated with other manganese oxides, pyrolusite and psilomelane and the iron-manganese mineral bixbyite. Wilhelm Haidinger (1827) named it in honour of Johann Friedrich Ludwig Hausmann (1782–1859), Professor of Mineralogy, University of Göttingen, Germany.

Image gallery

References

Manganese(II,III) minerals
Spinel group
Tetragonal minerals
Minerals in space group 141
Briquetage. Briquetage or very coarse pottery (VCP) is a coarse ceramic material used to make evaporation vessels and supporting pillars used in extracting salt from brine or seawater. Thick-walled saltpans were filled with saltwater and heated from below until the water had boiled away and salt was left behind. Often, the bulk of the water would be allowed to evaporate in salterns before the concentrated brine was transferred to a smaller briquetage vessel for final reduction. Once only salt was left, the briquetage vessels would have to be broken to remove the valuable commodity for trade.

Broken briquetage material is found at multiple sites from the later Bronze Age in Europe into the medieval period and archaeologists have been able to identify different forms and fabrics of the pottery, allowing trade networks to be identified. Saltworking sites contain large quantities of the orange/red material and in Essex the mounds of briquetage are known as Red Hills. A recent discovery at the Poiana Slatinei archaeological site next to a salt spring in Lunca, Neamt County, Romania, indicates that Neolithic people of the Precucuteni Culture were boiling the salt-laden spring water through the process of briquetage to extract the salt as far back as 6050 BC, making it perhaps the oldest saltworks in history.

References

Archaeological artefact types
Ceramic materials
AKG. AKG may refer to:

alpha-Ketoglutaric acid, also known as 2-Ketoglutaric acid, 2-Oxopentanedioic acid, 2-Oxoglutamate, 2-Oxoglutaric acid & Oxoglutaric acid
Asian Kung-Fu Generation, a Japanese rock band
Alternatív Közgazdasági Gimnázium, a high school in Budapest, Hungary
A. K. Gopalan (1904–1977), Indian communist leader
A. K. G. (film), a 2007 Indian Malayalam documentary film
The ICAO Code for No. 84 Squadron RAF, United Kingdom
AKG (company), an acoustics engineering and manufacturing company
Buffalo AKG Art Museum, an art museum in Buffalo, New York
Trisil. Trisil is a trade name for a thyristor surge protection device, an electronic component designed to protect electronic circuits against overvoltage.  Unlike a transient voltage suppression diodes, such as Transil, a Trisil acts as a crowbar device, switching ON when the voltage on it exceeds its breakover voltage.

Overview 
A Trisil is bidirectional, behaving the same way in both directions. It is principally a voltage-controlled triac without gate.  The behavior of a Trisil is similar to a SIDAC, but unlike SIDAC, Trisil devices are commonly used to protect circuits from overvoltage. They act faster and can handle more current.  In 1982, the only manufacturer was Thomson SA; a successor company, ST Microelectronics continues to make the devices.

This type of crowbar protector is widely used for protecting telecom equipment from lightning-induced transients and induced currents from power lines.  Other manufacturers of this type of device include Bourns (TISP) and Littelfuse (SIDACtor).  Rather than using the natural breakdown voltage of the device, an extra region is fabricated within the device to form a Zener diode.  This allows a much tighter control of the breakdown voltage.

It is also possible to make gated versions of this type of protector.  In this case, the gate is connected to the telecom circuit power supply (via a diode or transistor) so that the device will crowbar if the transient exceeds the power supply voltage.  The main advantage of this configuration is that the protection voltage tracks the power supply, thus eliminating the problem of selecting a particular breakdown voltage for the protection circuit.

See also 
 Transil
 Zener diode

References

External links 
 Overvoltage protection
 Trisil/Transil Comparison, ST Application Note (PDF)

Solid state switches
Voltage stability