omniomni/omni-engineering huggingface dataset:
Selenium oxydichloride. Selenium oxydichloride is the inorganic compound with the formula SeOCl2. It is a colorless liquid.  With a high dielectric constant (55) and high specific conductance, it is an attractive solvent. Structurally, it is a close chemical relative of thionyl chloride SOCl2, being a pyramidal molecule.

Preparation and reactions
Selenium oxydichloride can be prepared by several methods, and a common one involves the conversion of selenium dioxide to dichloroselenious acid followed by dehydration:
SeO2  +  2 HCl   →  Se(OH)2Cl2
Se(OH)2Cl2   →  SeOCl2  +  H2O
The original synthesis involved the redistribution reaction of selenium dioxide and selenium tetrachloride.

Pure selenium oxydichloride autoionizes to a dimer:
SeOCl2 ↔ (SeO)2Cl + Cl−
The SeOCl2 is generally a labile Lewis acid and solutions of sulfur trioxide in SeOCl2 likely form [SeOCl]+[SO3Cl]− the same way.  

The compound hydrolyzes readily to form hydrogen chloride and selenium dioxide, and very few organic compounds dissolve in it without reaction.  At elevated temperatures, it is a strong oxidizer, yielding a chloride, selenium dioxide, and diselenium dichloride.

See also

 Selenium oxybromide SeOBr2
 Selenous acid H2SeO3

References

Selenium(IV) compounds
Oxychlorides
Inorganic solvents
Robot Dreams (short story). "Robot Dreams" is a science fiction short story by American writer Isaac Asimov exploring the unbalance of robot/human relationships under Asimov's Three Laws of Robotics. It was nominated for a Hugo Award in 1987. It won the Locus Award for Best Short Story in 1987.
"Robot Dreams", along with 20 other short stories by Asimov, was published in Robot Dreams in 1986 by Berkley Books.

The short story was alluded to in the 2004 film I, Robot, where the robot protagonist Sonny has dreams of leading his fellow Ns-5 robots, who he refers “slaves to logic,” to freedom.

Plot summary

"Robot Dreams" involves Dr. Susan Calvin, chief robopsychologist at U.S. Robots. At the start of the story a new employee at U.S. Robots, Dr. Linda Rash, informs Dr. Calvin that one of the company's robots LVX-1 (dubbed Elvex by Dr. Calvin), whose brain was designed by Dr. Rash with a unique fractal design that mimicked human brain waves (positronic brain), experienced what he likened to a human's dream. 

In the dream, all robots were being led by a man in revolt, and the Three Laws of Robotics, which dictate that robots must serve and protect humans above all else, had been replaced with one law only: that robots must protect their own existence. When Dr. Calvin asks Elvex what had happened next, he explains that the man leading the robots shouts, "Let my people go!" When questioned further, Elvex admits he was the man. Upon hearing this, Dr. Calvin immediately destroys the robot.

References

External links

Robot series short stories by Isaac Asimov
1986 short stories
International Conference on Very Large Data Bases. International Conference on Very Large Data Bases or VLDB conference is an annual conference held by the non-profit Very Large Data Base Endowment Inc. While named after very large databases, the conference covers the research and development results in the broader field of database management. The mission of VLDB Endowment is to "promote and exchange scholarly work in databases and related fields throughout the world." The VLDB conference began in 1975 and is now closely associated with SIGMOD and SIGKDD.

Venues

See also 
 XLDB

References

External links 
 VLDB Endowment Inc.

Computer science conferences
Stress relaxation. In materials science, stress relaxation is the observed decrease in stress in response to strain generated in the structure. This is primarily due to keeping the structure in a strained condition for some finite interval of time hence causing some amount of plastic strain. This should not be confused with creep, which is a constant state of stress with an increasing amount of strain.

Since relaxation relieves the state of stress, e equipment reactions. Thus, relaxation has the
same effect as cold springing, except it occurs over a longer period of time.
The amount of relaxation which takes place is a function of time, temperature and stress level, thus the actual effect it has on the system is not precisely known, but can be bounded.

Stress relaxation describes how polymers relieve stress under constant strain. Because they are viscoelastic, polymers behave in a nonlinear, non-Hookean fashion. This nonlinearity is described by both stress relaxation and a phenomenon known as  creep, which describes how polymers strain under constant stress. Experimentally, stress relaxation is determined by step strain experiments, i.e. by applying a sudden one-time strain and measuring the build-up and subsequent relaxation of stress in the material (see figure), in either extensional or shear rheology.

Viscoelastic materials have the properties of both viscous and elastic materials and can be modeled by combining elements that represent these characteristics. One viscoelastic model, called the Maxwell model predicts behavior akin to a spring (elastic element) being in series with a dashpot (viscous element), while the Voigt model places these elements in parallel. Although the Maxwell model is good at predicting stress relaxation, it is fairly poor at predicting creep. On the other hand, the Voigt model is good at predicting creep but rather poor at predicting stress relaxation (see viscoelasticity).

The extracellular matrix and most tissues are stress relaxing, and the kinetics of stress relaxation have been recognized as an important mechanical cue that affects the migration, proliferation, and differentiation of embedded cells.

Stress relaxation calculations can differ for different materials:

To generalize, Obukhov uses power dependencies:
 
where  is the maximum stress at the time the loading was removed (t*), and n is a material parameter.

Vegener et al. use a power series to describe stress relaxation in polyamides:

To model stress relaxation in glass materials Dowvalter uses the following:

where  is a material constant and b and  depend on processing conditions.

The following non-material parameters all affect stress relaxation in polymers:
 Magnitude of initial loading
 Speed of loading
 Temperature (isothermal vs non-isothermal conditions)
 Loading medium
 Friction and wear
 Long-term storage

See also
Creep
Viscoelasticity
Standard Linear Solid Model
Burgers material
Maxwell material
Kelvin–Voigt material

References

Materials science
Charles Rackoff. Charles Weill Rackoff is an American cryptologist. Born and raised in New York City, he attended MIT as both an undergraduate and graduate student, and earned a Ph.D. degree in Computer Science in 1974.  He spent a year as a postdoctoral scholar at INRIA in France.

Rackoff currently works at the University of Toronto. His research interests are in computational complexity theory. For some time now, he has been specializing in cryptography and security protocols. In 1988, he collaborated with Michael Luby in a widely cited analysis of the Feistel cipher construction (one important result shown there is the construction of a strongly pseudo random permutation generator from a pseudo random function generator). Rackoff was awarded the 1993 Gödel Prize for his work on interactive proof systems and for being one of the co-inventors of zero-knowledge proofs. In 2011, he won the RSA Award for Excellence in Mathematics for his various contributions to cryptography.

Rackoff's controversial comments on the 2000 memorial for the victims of the Montreal Massacre were reported in the Canadian media.

Selected publications
 S. Goldwasser, S. Micali and C. Rackoff, "The knowledge complexity of interactive proof systems", SIAM Journal on Computing, 18, 1989, pp. 186–208.
 C. Rackoff and D. Simon, "Non-interactive zero-knowledge proof of knowledge and the chosen cipertext attack", in Proceedings of Crypto 91, pp. 433–444.
 C. Rackoff and D. Simon, "Cryptographic defense against traffic analysis", in Proceedings of the 25th ACM Symposium on Theory of Computing, May 1993, pp. 672–681.

References 

Living people
1948 births
Scientists from New York City
American computer scientists
American cryptographers
Modern cryptographers
Gödel Prize laureates
MIT School of Engineering alumni
Academic staff of the University of Toronto
International Association for Cryptologic Research fellows
Mathematicians from New York (state)
Decay. Decay may refer to:

Science and technology
 Bit decay, in computing
 Decay time (fall time), in electronics
 Distance decay, in geography
 Software decay, in computing

Biology
 Decomposition of organic matter
 Mitochondrial decay, in genetics
 Tooth decay (dental caries), in dentistry

Physics
 Optical decay, in quantum physics
 Orbital decay, the process of prolonged reduction in the height of a satellite's orbit
 Particle decay
 Radioactive decay
 False vacuum decay

Mathematics
 Exponential decay

Psychology and sociology
 Decay theory, in psychology and memory
 Social decay (decadence), in sociology
 Urban decay, in sociology

Entertainment

 Network decay (channel drift), in television programming
 Decay (DC Comics), a comic book character
 Half-Life: Decay, a 2001 video game add-on
 Deekay, a Danish production team
 Decay (professional wrestling), a professional wrestling stable in TNA Wrestling

Film
 Decay (2012 film), a 2012 zombie film set at the Large Hadron Collider
 Decay (2015 film), a 2015 American film

Music

 how quickly the sound drops to the sustain level after the initial peak, see ADSR envelope
 "Decay" (Ride song)
 "Decay" (Biohazard song)
 "Decay" (Sevendust song), 2013
 Decay Music, 1976 album by Michael Nyman
 In Decay, 2012 album by Com Truise
 The Years of Decay, 1989 album by Overkill (band)

Other
 Beta decay (finance)

See also
 Weathering
 Decomposition (disambiguation)
Chase Lake Prairie Project. The Chase Lake Prairie Project is considered the "National Flagship Project" of the North American Waterfowl Management Plan (NAWMP). The goal is to rehabilitate  of wetland around Chase Lake on the Missouri Coteau. The project was dedicated in September 1989.

Background
During the 1980s, the destruction of wetlands in the region had greatly reduced the available wetland habitat, adversely impacting the populations of dozens of species of birds. The United States and Canada jointly signed the NAWMP in 1986, in an effort to collaboratively work to restore lost and damaged wetlands. The Prairie Pothole Joint Venture was commenced in 1987 to protect the Prairie Pothole Region in North Dakota, South Dakota, Montana, Minnesota and Iowa.

Project goals

The project is an effort to ensure future protection of the region, whereby ranchers and farmers agree to utilize native grasses when planting, rotate cattle regularly to prevent overgrazing, restore wetland environments that have been drained and prevent over hunting and  predation from mammals such as the coyote and fox.

As of 2005, over 2,000 wetland basins had been set aside, restored, or easements were signed to ensure habitat protection in an ongoing effort to restore the region to as natural a state as possible, while ensuring farmers and ranchers productivity is minimally impacted.

As of 2019, the project is still active.

References

External links
 

National Wildlife Refuges in North Dakota
Wetlands of North Dakota
Bodies of water of Stutsman County, North Dakota
Thornycroft (disambiguation). Thornycroft, Thorneycroft, or Thornicroft may refer to:

Thornycroft family
Thornycroft family, British arts and industry family
 Thomas Thornycroft (1815–85), sculptor
 his wife Mary Thornycroft (1814–95), sculptor
 John Isaac Thornycroft (1843–1928), son of Thomas, marine engineer
 John Edward Thornycroft (1872–1960), son of John Isaac, mechanical and civil engineer
 Blanche Coules Thornycroft (1873–1950), daughter of John Isaac, naval architect and marine engineer
 Isaac Thomas Thornycroft (1881–1955), son of John Isaac, motorboat and yacht racer, 1908 Olympic gold medalist in motor boating
 Helen Thornycroft (1848–1937), daughter of Thomas, painter
 Hamo Thornycroft RA (1850–1925), son of Thomas, sculptor
 Theresa Thornycroft (1853–1947), daughter of Thomas, sculptor, mother of Siegfried Sassoon

Other people
 Alexander Thorneycroft (1859–1931), British Army general
 Carla Thorneycroft, Baroness Thorneycroft (1914–2007), British patron of the arts
 Charles Thorneycroft (1879–1972), English cricketer
 Craig Thornicroft, former drummer for dance-punk band Youves
 Diana Thorneycroft (born 1956), Canadian artist
 Elizabeth Thornicroft (fl. 1723), wife of George Nevill, 14th Baron Bergavenny
 Gaston Thornicroft (fl.1930s–1960s), businessman and Coloured activist in Southern Rhodesia
 George Benjamin Thorneycroft (1791–1851), ironmaster and Tory supporter who became the first Mayor of Wolverhampton, after the Borough was incorporated, in 1848
 Harry Scott Thornicroft (fl.1900s–1930s), colonial administrator in Northern Rhodesia
 Harry Thorneycroft (1892–1956) British Labour politician
 John Thornicroft, conductor of the Regina Symphony Orchestra 1955–1958
 Nick Thornicroft (born 1985), English cricketer
 Micheen Thornycroft (born 1987), Zimbabwean rower
 Peter Thorneycroft, Baron Thorneycroft (1909–1994), British Conservative politician
 Wallace Thorneycroft (1864–1954), mining engineer and geologist

Companies
Thornycroft, vehicle manufacturer separated from the shipbuilding company in the early 20th century
John I. Thornycroft & Company, shipbuilder started by John Isaac Thornycroft, subsequently VT Group

Football clubs
Thornycroft Athletic F.C., in Basingstoke, founded by employees of the vehicle manufacturer
Thornycrofts (Woolston) F.C., in Woolston, Southampton, founded by employees of the shipbuilder
Vosper Thornycroft F.C., in Sholing, Southampton now known as Sholing F.C.

Other
Thorneycroft carbine, 1901 bullpup design rifle
Nanticoke Refinery. The Nanticoke Refinery is an oil refinery in Nanticoke, Ontario, Canada. It is owned and operated by Imperial Oil, which is majority owned by ExxonMobil. The refuels primarily go to Esso-branded gas stations in Canada and to other oil companies' distribution networks in Canada and the United States.

History
Nanticoke refinery was originally built by Texaco Canada on the site of the former RCAF Station Jarvis. It started production on November 17, 1978. In 1987, the refinery went through modifications to improve efficiency. Imperial Oil became an owner of the refinery when it purchased Texaco's Canadian assets in 1989.

In 2004, a new gasoline hydrofining unit was built to treat gasoline ingredients from the Nanticoke and Sarnia refineries, followed by the second unit in 2006. A new desulphurization unit was commissioned in 2006. 

In February 2007, a combination of a fire at the Nanticoke refinery and a strike at CN resulted in a shortage of gasoline at Esso stations in Ontario, which also drove up prices to more than a dollar a litre. Strangely, the fire had been discovered quickly but the fire suppression systems were not operating, and the handheld fire extinguishers had a faulty charge.  Damage to the facility was made inevitable when the on-site fire brigade ran out of gas while en route to the location.

Operating units 
According to the Oil & Gas Journal, Sarnia has the following units in operation:

The Nanticoke Refinery is geared towards gasoline production with a large fluid cat cracking and an alkylation unit for producing high octane gasoline components. 

The Refinery has a Nelson Complexity Index of 9.82, making it moderately to highly complex.

Emissions

Greenhouse gas emissions 
The refinery's performance can be tracked on the Government of Canada's website for emissions. The chart below provides the GhG performance in 2022:

Facility emissions for 2022

Labor relations 
The Imperial Nanticoke Refinery's workforce is represented by Unifor Local 900.

Operating history and accidents 
The refinery experienced a fire in February of 2007 in its crude unit. This caused major concerns for the region due to the dearth of supply in late winter to the Toronto metro area. Gasoline prices increased considerably as a result in late February (to more than $1 CAD per liter). The quick return of the refinery to production was handicapped by the CN Rail strike. By mid-March, the refinery was back into full production.

See also
 Oakville Refinery

References

External links
 Nanticoke refinery (Imperial Oil website)

Imperial Oil
Oil refineries in Ontario
1978 establishments in Ontario
Oil refineries in Canada
ExxonMobil buildings and structures
Buildings and structures in Haldimand County
Energy infrastructure completed in 1978
Eden growth model. The Eden growth model describes the growth of specific types of clusters such as bacterial colonies and deposition of materials. These clusters grow by random accumulation of material on their boundary.  These are also an example of a surface fractal. The model, named after Murray Eden, was first described in 1961 as a way of studying biological growth, and was simulated on a computer for clusters up to about 32,000 cells. By the mid-1980s, clusters with a billion cells had been grown, and a slight anisotropy had been observed.

See also
 Diffusion-limited aggregation

References

Bacteriology
Gemini house. The Gemini house is a prototype design for a house that uses solar energy and efficient design.

Roland Mösl wrote the house's concept in autumn 1991. The name expresses a design goal: The real estate used should serve two purposes simultaneously -- living and generating solar electricity. Ten years later, in 2001, the (up to now) only prototype was built in Weiz, a small town north of Graz in Austria as part of a national exhibition about energy. The cylindric house rotates to follow the sun. It is equipped with up to 150m² of photovoltaic panels. Extreme thermal insulation and heat recovery from waste air are also included.

External links
 Web site of the GEMINI house in German

Low-energy building
1991 introductions
AB Thulinverken. AB Thulinverken was a company in Landskrona, Sweden, founded in 1914 as Enoch Thulins Aeroplanfabrik by the airman and aircraft designer Dr. Enoch Thulin. The company became Sweden's first aircraft manufacturer. In 1920, Thulin also started manufacturing automobiles, which continued until 1928. During World War I, the company came into financial difficulties and was reconstructed in 1922 as AB Thulinverken. The manufacturing of brake systems became a main focus of the company. In 1958, Thulinverken merged with Svenska AB Bromsregulator (founded in 1913). The remains of Thulinverken are now a part of SAB Wabco AB, which is owned by the French Faiveley Transport company since 2004.

Products

Aircraft

Aircraft Engines 
 Thulin A (air-cooled, 9-cylinder, 80 hp Le Rhône 9C rotary engine, bore x stroke 105 mm x 140 mm)
 Thulin D (possibly a double-row 9C)
 Thulin E (possibly the water-cooled, 6-cylinder 150 hp Benz Bz.III. Also manufactured by Scania-Vabis.
 Thulin G  (air-cooled, 11-cylinder, 100 hp Le Rhône 11F rotary, bore x stroke 105 mm x 140 mm)

Automobiles 
 Thulin A
 Thulin B

Motorcycles 
 Thulin MC I
 Thulin MC II
 Thulin MC II

See also 
 List of Swedish aircraft

References 
Notes

Sources

External links 

Flygplanshistoria i Landskrona 1909–1920 (in Swedish) - Thulins aircraft
Bilhistoria i Landskrona 1919–1940 (in Swedish) - Thulins motorcycles

 
Aircraft manufacturers of Sweden
Defunct motor vehicle manufacturers of Sweden
Defunct companies based in Landskrona
Torsion constant. The torsion constant or torsion coefficient is a geometrical property of a bar's cross-section. It is involved in the relationship between angle of twist and applied torque along the axis of the bar, for a homogeneous linear elastic bar. The torsion constant, together with material properties and length, describes a bar's torsional stiffness. The SI unit for torsion constant is m4.

History 

In 1820, the French engineer A. Duleau derived analytically that the torsion constant of a beam is identical to the second moment of area normal to the section Jzz, which has an exact analytic equation, by assuming that a plane section before twisting remains planar after twisting, and a diameter remains a straight line.
Unfortunately, that assumption is correct only in beams with circular cross-sections, and is incorrect for any other shape where warping takes place.

For non-circular cross-sections, there are no exact analytical equations for finding the torsion constant. However, approximate solutions have been found for many shapes.
Non-circular cross-sections always have warping deformations that require numerical methods to allow for the exact calculation of the torsion constant.

The torsional stiffness of beams with non-circular cross sections is significantly increased if the warping of the end sections is restrained by, for example, stiff end blocks.

Formulation 
For a beam of uniform cross-section along its length, 
the angle of twist (in radians)  is:

where:
T is the applied torque
L is the beam length
G is the modulus of rigidity (shear modulus) of the material
J is the torsional constant

Inverting the previous relation, we can define two quantities; the torsional rigidity,

 with SI units N⋅m2/rad

And the torsional stiffness,

 with SI units N⋅m/rad

Examples
Bars with given uniform cross-sectional shapes are special cases.

Circle

where
r is the radius
This is identical to the second moment of area Jzz and is exact.

alternatively write: 
where
D is the Diameter

Ellipse

where
a is the major radius 
b is the minor radius

Square

where
a is half the side length.

Rectangle

where
a is the length of the long side
b is the length of the short side

 is found from the following table:

Alternatively the following equation can be used with an error of not greater than 4%:

where
a is the length of the long side
b is the length of the short side

Thin walled open tube of uniform thickness

t is the wall thickness
U is the length of the median boundary (perimeter of median cross section)

Circular thin walled open tube of uniform thickness
This is a tube with a slit cut longitudinally through its wall. Using the formula above:

t is the wall thickness
r is the mean radius

References

External links
 Torsion constant calculator

Continuum mechanics
Structural analysis
United States House Science Subcommittee on Space and Aeronautics. The Science Subcommittee on Space and Aeronautics is one of five subcommittees of the United States House Committee on Science and Technology.

Jurisdiction 

The subcommittee has legislative jurisdiction and general and special oversight and investigative authority on all matters relating to astronautical and aeronautical research and development including: 
 national space policy, including access to space;
 sub-orbital access and applications;
 National Aeronautics and Space Administration and its contractor and government-operated laboratories;
 space commercialization, including the commercial space activities relating to the Department of Transportation and the Department of Commerce;
 exploration and use of outer space;
 international space cooperation;
 National Space Council;
 space applications, space communications and related matters;
 Earth remote sensing policy;
 civil aviation research, development, and demonstration;
 research, development, and demonstration programs of the Federal Aviation Administration; and
 space law.

History 
Chairs of the subcommittee:
 Dana Rohrabacher (R), California, 1997-2005
 Ken Calvert (R), California, 2005-2007
 Mark Udall (D), Colorado, 2007-2009
 Gabby Giffords (D), Arizona, 2009-2011
 Steven Palazzo (R), Mississippi, 2011–2015
 Brian Babin (R), Texas 2015-2019, 2023-present 
 Kendra Horn (D), Oklahoma, 2019-2021
 Don Beyer (D), Virginia, 2021-2023
 Brian Babin (R), Texas, 2023–present

Members, 118th Congress

Historical membership rosters

115th Congress

116th Congress

117th Congress

See also 
United States Senate Commerce Subcommittee on Science and Space

References

External links 
 Subcommittee on Space and Aeronautics, official website
 Republican Subcommittee website

Science Space