omniomni/omni-engineering huggingface dataset:
Macphersonite. Macphersonite, Pb4(SO4)(CO3)2 (OH)2, is a carbonate mineral that is trimorphous with leadhillite and susannite. Macphersonite is generally white, colorless, or a pale amber in color and has a white streak. It crystallizes in the orthorhombic system with a space group of Pcab.  It is fairly soft mineral that has a high specific gravity.

Macphersonite is named after Harry Gordon Macpherson, a keeper of minerals at the Royal Scottish Museum.  It was discovered and accepted in 1984.

Structure 
The structure of macphersonite is represented as a sequence of three layers stacked along the [001]. The first layer is a sulfate tetrahedra, the second is of lead and hydroxide, and the third is a layer composed of lead and carbonate. Stacking of the three layers can be detailed as ...BABCCBABCC... similar to leadhillite.  Two C layers of lead carbonate in the BAB stacking provide a weak connection that leads to the perfect {001} cleavage.

Physical properties 
The Leadhills macphersonite is a very pale amber to colorless in color, while the Argentolle mine macphersonite is colorless to white.  It has a luster of adamantine on fresh surfaces and elsewhere it is resinous. Macphersonite is soft with a 2.5-3 on the Mohs hardness, has an uneven fracture with a high density of 6.5g/cm3.

Macphersonite has a very strong yellow fluorescence under both long and short wave, ultraviolet is displayed by the Leadhills specimens, the Argentolle material does not fluoresce.

Occurrence 
Macphersonite is found in the Leadhills region of southwest Scotland and in the Saint-Prix, Saône-et-Loire region of France. It is the rarest of the three polymorphs. It occurs in lead deposits associated with cerussite, susannite, caledonite, scotlandite, leadhillite, galena and pyromorphite.

References

Carbonate minerals
Orthorhombic minerals
Minerals in space group 61
Eric Klopfer. Eric Klopfer (born October 8, 1970) is a professor and director of the Scheller Teacher Education Program and the education arcade at MIT. Klopfer's research explores how educational technology, games, and computer simulations can be tools for teaching complex systems and developing cognitive and computational thinking skills.  Klopfer and his research group developed StarLogo and App Inventor for Android and other visual programming language platforms that build on the work of Seymour Papert and constructionism in education. He is also the principal investigator in the research and development of award-winning games designed for building understanding in science and math, connecting game play with scientific practice, problem-solving, and real-world issues.

In 2014, Klopfer produced a series of four online courses on the edX learning platform, delivering videos, tools, and assignments for participants to create, implement, and evaluate projects in educational technology. Klopfer is co-founder and past president of the non-profit Learning Games Network, co-author of Adventures in Modeling and The More We Know, and the author of Augmented Learning.

He is a triathlete, the husband of Rachel Klopfer, and the father of two children.

References

External links
 Eric Klopfer's profile page

Cornell University alumni
University of Wisconsin–Madison alumni
MIT School of Architecture and Planning faculty
Living people
1970 births
Santa Fe Institute people
EvoSuite. EvoSuite is a tool that automatically generates unit tests for Java software. EvoSuite uses an evolutionary algorithm to generate JUnit tests. EvoSuite can be run from the command line, and it also has plugins to integrate it in Maven, IntelliJ and Eclipse. EvoSuite has been used on more than a hundred open-source software and several industrial systems, finding thousands of potential bugs.

History
EvoSuite was originally created in 2010 as output of a research project by Dr. Gordon Fraser and Dr. Andrea Arcuri. EvoSuite is currently released under LGPL license, and its source code is hosted on GitHub. In academia, EvoSuite is often referred as one of the main reference tools for search-based software testing.

Other usages
As EvoSuite is released as open-source (and so freely available to download and modify), it has been used as a reference tool for search-based software testing in a number of independent studies, like:
 Comparison with other tools like Pex, CATG, jPET and SPF
 Extension to system level testing for XML inputs
 Extension to study many-objective genetic algorithms

See also
 Test data generation
 Search-based software engineering
 Test automation
 List of unit testing frameworks
 Unit testing

Bibliography

References

External links

EvoSuite publications page

Java platform software
Rakovanite. Rakovanite, (NH4)3Na3(V10O28) · 12H2O; formerly given as Na3(H3V10O28).15H2O; later, the ammonium ion was shown to be present and essential, is a member of the pascoite family. It is a transparent, brittle mineral occurring in the monoclinic crystal system. It is orange in color and has an orange-yellow colored streak. Rakovanite is soft with a Mohs hardness of 1 and a calculated density of 2.407g cm−3. It does not fluoresce in long- or short-wave ultraviolet radiation. Rakovanite crystals are up to one mm in maximum dimension and vary in habit from blocky to prismatic on [001], commonly exhibiting steps and striations parallel to [001].  Its name honors John Rakovan, former professor, Department of Geology and Environmental Earth Science, Miami University, State Mineralogist and Senior Museum Curator, New Mexico Bureau of Geology and Mineral Resources.

Occurrence 
Rakovanite was found on specimens from the Sunday mine and the West Sunday mine, Slick Rock district, San Miguel County, Colorado, US.

It occurs as crystalline crusts on sandstone fractures in the mine walls of the Sunday and West Sunday mines. The best crystals were found perched on an amorphous dehydrated vanadium phase along with crystals tightly adhered to a corvusite-montroseite matrix.

It forms from the oxidation of montroseite-corvusite assemblages. It is associated calcite, corvusite, hewettite, hughesite, montroseite, munirite, paramontroseite, pascoite, rossite, sherwoodite, and other unidentified vanadium phases as well as at least two other potentially new decavanadate species. It forms aqueous solutions of relatively low pH when water reacts with pyrite in the deposit under ambient temperatures and generally oxidizing near-surface environments.

Atomic arrangement
Rakovanite crystal unit consists of the decavanadate polyanion similar to that found in other decavanadate-bearing mineral. The decavanadate polyanion is formed of ten distorted, edge-sharing octahedra.

Chemical composition

The empirical formula with calculated H2O and (NH4)2O contents is [(NH4)2.94K0.06]Σ3.00(Na2.97Al0.01 Ca0.01)Σ2.99[V10O28]12H2O (–0.01 H for charge balance) and the ideal formula is (NH3)3Na3 [V10O28]12H2O.

See also

 Classification of minerals
 List of minerals
 Rakovanite on Mindat

References

Oxide minerals
Monoclinic minerals
Minerals in space group 14
Grayite. Grayite, ThPO4·(H2O), is a thorium phosphate mineral of the Rabdophane group first discovered in 1957 by S.H.U. Bowie in Rhodesia. It is of moderate hardness occurring occasionally in aggregates of hexagonal crystals occasionally but more commonly in microgranular/cryptocrystalline masses. Due to its thorium content, grayite displays some radioactivity although it is only moderate and the mineral displays powder XRD peaks without any metamict-like effects. The color of grayite is most commonly observed as a light to dark reddish brown but has also been observed as lighter yellows with grayish tints. It has a low to moderate hardness with a Mohs hardness of 3–4 and has a specific gravity of 3.7–4.3. It has been found in both intrusive igneous and sedimentary environments.

Occurrence 
Formations including grayite were originally documented in Rhodesia (now Zimbabwe) in 1957 and subsequently around the globe. Some of these locales include the states of Wyoming and Colorado as well as Madagascar. Grayite has often been found in pegmatitic environments amongst other thorium minerals, particularly monazite (). Recent work has shown widespread occurrences in Wisconsin pegmatitic environments. Other notable finds of pegmatitic grayite occur in Bulgaria. Grayite has also been found in sedimentary environments with an observation of high concentrations in cracks raising the possibility of the mineral as a precipitate from fluid mobilized ions. Formation of grayite and other rhabdophane minerals in this context has been documented in literature.

As member of rhabdophane group
Grayite is isostructural with members of the Rhabdophane group such as brockite and rhabdrophane. While previous work has identified grayite as a pseudohexagonal orthorhombic member of the rhabdophane group along with ningyoite, more contemporary work seems to maintain a hexagonal crystal structure. These hydrated phosphate minerals often include radioactive elements such as thorium, uranium, and cerium. Powder XRD analysis produces peaks matching those of rhabdophane.

Relationship with monazite
In the identification of new hydrated phosphate minerals related to rhabdophane XRD peak information is usually recorded through different sample preparation methods. Besides standard powder XRD, samples are often heated to ~850 °C so that the structure changes. The peak information is analyzed again and upon doing this hydrated thorium phosphate minerals will show a monazite-like structure indicating a possible alteration relationship.

See also

 Classification of minerals
 List of minerals

References

External links

Thorium minerals
Phosphate minerals
Radioactive minerals
Hexagonal minerals
Minerals in space group 180 or 181
Natural materials
Georgy Mihailovich Kondratiev. Georgy Mihailovich Kondratiev (, 17 June 1887 – 11 August 1958) was a Russian physicist, specialist in thermal measurements.

Biography

Graduated from Saint Petersburg State University in 1912 and from Saint Petersburg State Polytechnic University in 1923. In 1917-1918 attended High Course of Pedagogic.

From 1924 to 1943 was a head of a laboratory and a head of a department in the Research Institute of Meteorology in Leningrad. In 1932 became chairman of Thermal Insulation Committee and a member of The Central board of Scientific and Technical Society of Energetic Industry Workers.

From the year 1935 took significant part in scientific life of many institutes, like Leningrad Region State Institute for Thermal Machine Engineering, Institute of Refractory Materials, etc. In 1936 became professor of Leningrad Institute for Cooling Industry.

In 1940 Georgy Kondratiev received Doctor degree.

In Leningrad Institute for Precise Mechanics and Optics Georgy Kondratiev occupied several positions: head of the Heat-control Department (1938-1942); head of the Physics Department (1949-1950); head of the Thermal Physics Department (1948); and head of the Thermal and Measurement Devices Department (1956-1958). From 1948-1952 was elected Dean of Department of Engineering and Physics department.

Georgy Condratiev founded scientific school of heat and mass exchange in instrumentation area. Also, Georgy Condratiev developed a few devices.

in 1949 he was awarded USSR State Prize for design of devices that were able to measure material heat properties in a short time. In 1957 he was awarded degree of Honoured master of sciences and engineering.

He also was awarded Order of Lenin, Order of the Red Star, Medal "For the Defence of Stalingrad" and by Medal "For Valiant Labour in the Great Patriotic War 1941–1945".

References

External links
 Photo
 Photo
 The Best scientists of ITMO
 Georgy Mihailovich Kondratiev at ITMO Virtual Museum

1887 births
1958 deaths
Optical physicists
Russian university and college faculty deans
Scientists from Saint Petersburg
Academic staff of ITMO University
Dual fluid reactor. The Dual Fluid Reactor is a reactor concept of the Canadian company Dual Fluid Energy Inc. It combines techniques from molten salt reactors (MSR) and liquid metal cooled reactors. It is intended to reach the criteria for reactors of the Generation IV International Forum.

Design 
The fuel can be a molten solution of actinide chloride salts, or it can be pure liquid actinide metal. Cooling is provided by molten lead in a separate loop. It is a fast breeder reactor, and can use both uranium and thorium to breed fissile material, as well as recycle processed high-level waste and plutonium. 

The reactor is inherently safe, because decay heat can be removed passively. This takes advantage of the high thermal conductivity of the molten metal.

U-238 of a spent nuclear fuel element of a light water reactor can be dissolved in Chlorine-salt, including long-living transuranic isotopes. Breeding and fission could power a 300MW electrical Dual Fluid Reactor for about 25 years. The initial fuel would be completely converted into fission products with radiotoxicity reduced from a hundreds of thousands of years to a few hundred years. This essentially eliminates the need for problematic long term storage.

History  
A conceptual predecessor of the Dual Fluid Reactor was the UK 1970s lead-cooled fast spectrum molten salt reactor (MSFR), which dissolved the fissile fuel in a molten salt, with experimental work undertaken over 1968-73, before it lost funding.

The Dual Fluid Reactor was initially developed by a German research institute, the Institute for Solid-State Nuclear Physics in Berlin. In February 2021, the six inventors, along with the existing team, formed Canadian company Dual Fluid Energy Inc. to commercialize the design. In June 2021, the company secured over $6 million in Canadian seed funding.

One patent has been obtained, and another is pending on the liquid metal fuel variant.

The reactor design won the public vote for the Galileo Knowledge Prize in the German GreenTec Awards of 2013, although the award committee presiding over the awards changed the rules to exclude nuclear designs before announcing the winner. Dual Fluid participants successfully sued to remedy this.

In 2023 the company signed a deal signed with the Rwanda Atomic Energy Board (RAEB) to build a demonstrator reactor. The reactor is expected to be complete by 2026 and complete testing by 2028.

References

Further reading 
 A new concept for a nuclear reactor. Triumf lectures, Hussein 2014
 Analysis and Evaluation of the Dual Fluid Reactor Concept, TU Munich
 Determination of the liquid eutectic metal fuel dual fluid reactor (DFRm) design – steady state calculations, 2019-04-04

External links 
Dual Fluid Reactor website
Dual Fluid Reactor at Institute for Solid-State Nuclear Physics
Dual Fluid Reactor - IFK - All-in-one PDF summary of the concept

Liquid metal fast reactors
Nuclear power reactor types
Av8er Explorer. The Av8er Explorer is a British paramotor that was designed by Paul Taylor and produced by Av8er Limited of Woodford Halse, Northamptonshire for powered paragliding. Now out of production, when it was available the aircraft was supplied complete and ready-to-fly.

Design and development
The Explorer was designed to comply with the US FAR 103 Ultralight Vehicles rules as well as European regulations. It features a paraglider-style wing, single-place accommodation and a single engine in pusher configuration. The aircraft is built with special attention to balancing and vibration isolation. The cage assembly includes small wheels to ease ground movement of the motor unit.

As is the case with all paramotors, take-off and landing is accomplished by foot. Inflight steering is accomplished via handles that actuate the canopy brakes, creating roll and yaw.

Variants
Explorer XPE
Model with a  Hirth F33 engine in pusher configuration with a 2.2:1 ratio reduction drive and a  diameter two-bladed wooden propeller. The fuel tank capacity is .

Specifications (Explorer XPE)

References

Explorer
2000s British ultralight aircraft
Single-engined pusher aircraft
Paramotors
Av8er Observer Light. The Av8er Observer Light (or Lite) is a British paramotor that was designed by Paul Taylor and produced by Av8er Limited of Woodford Halse, Northamptonshire for powered paragliding. Now out of production, when it was available the aircraft was supplied complete and ready-to-fly.

Design and development
The Observer Light was designed to comply with the US FAR 103 Ultralight Vehicles rules as well as European regulations. It features a paraglider-style wing, single-place accommodation and a single engine in pusher configuration. The aircraft is built with special attention to balancing and vibration isolation. The cage assembly includes small wheels to ease ground movement of the motor unit.

As is the case with all paramotors, take-off and landing is accomplished by foot. Inflight steering is accomplished via handles that actuate the canopy brakes, creating roll and yaw.

Variants
Observer Light AV1
Model with a highly tuned  Radne Raket 120 Aero ES engine in pusher configuration with a 4:1 ratio reduction drive and a  diameter two-bladed wooden propeller. The fuel tank capacity is .
Observer Carbon Lite
Model with a two-piece carbon propeller.

Specifications (Observer Light AV1)

References

Observer Light
2000s British ultralight aircraft
Single-engined pusher aircraft
Paramotors
Av8er Orbiter. The Av8er Orbiter is a British paramotor that was designed by Paul Taylor and produced by Av8er Limited of Woodford Halse, Northamptonshire for powered paragliding. Now out of production, when it was available the aircraft was supplied complete and ready-to-fly.

Design and development
The Orbiter was designed to comply with the US FAR 103 Ultralight Vehicles rules as well as European regulations. It features a paraglider-style wing, single-place accommodation and a single engine in pusher configuration. The aircraft is built with special attention to balancing and vibration isolation. The cage assembly includes small wheels to ease ground movement of the motor unit.

As is the case with all paramotors, take-off and landing is accomplished by foot. Inflight steering is accomplished via handles that actuate the canopy brakes, creating roll and yaw.

Variants
Orbiter Lite
Model with a  Radne Raket 120 Aero ES engine in pusher configuration with a 4:1 ratio reduction drive and a  diameter two-bladed wooden propeller. The fuel tank capacity is .
Orbiter XP
Base model circa 2005.
Orbiter XPE
Model with electronic starting.
Orbiter XPR Light
Model with Radne Raket 120 engine.

Specifications (Orbiter Lite)

References

Observer Light
2000s British ultralight aircraft
Single-engined pusher aircraft
Paramotors
Av8er. Av8er Limited () was a British aircraft manufacturer based in Woodford Halse, Northamptonshire and founded by Paul Taylor. The company specialized in the design and manufacture of paramotors in the form of ready-to-fly aircraft for the US FAR 103 Ultralight Vehicles and European rules.

The company was founded in 1996. The company continues as an information technology firm, supplying data centre services, related equipment and aerial photography services using UAVs, computer servers, media platforms, instructional videos and off-road vehicle engines and parts.

In the aircraft production years Av8er manufactured a range of paramotors noted for their lightness and attention to detail, in particular balancing and vibration isolating features. The models included the Explorer, Orbiter, Observer and Titan.

Aircraft

References

External links

Company paramotoring website archives, 2001–11 on the Internet Archive
Company paramotoring website archives on the Internet Archive
	 

1996 establishments in England
Companies based in Northamptonshire
Defunct aircraft manufacturers of England
Paramotors
Ultralight aircraft
Spike (software development). A spike is a product development method originating from extreme programming that uses the simplest possible program to explore potential solutions. It is used to determine how much work will be required to solve or work around a software issue. Typically, a "spike test" involves gathering additional information or testing for easily reproduced edge cases.  The term is used in agile software development approaches like Scrum or Extreme Programming.

Uses 

A spike in a sprint can be used in a number of ways:
 As a way to familiarize the team with new hardware or software
 To analyze a problem thoroughly and assist in properly dividing work among separate team members.
 Spike tests can also be used to mitigate future risk, and may uncover additional issues that have escaped notice.

A distinction can be made between technical spikes and functional spikes. The technical spike is used more often for evaluating the impact new technology has on the current implementation. A functional spike is used to determine the interaction with a new feature or implementation.

To track such work items, in a ticketing system, a new user story can be set up for each spike, for organization purposes.

Following a spike, the results (a new design, a refined workflow, etc.) are shared and discussed with the team.

References 

Agile software development
Software development process
Norman J. Rees. Norman John Rees, ( – February 29, 1976) was an Italian-American oil engineer who was an agent for
Soviet intelligence, then became a double agent for the FBI. Rees committed suicide when a newspaper revealed his spying activities.

Early life and career
Rees was born Nuncio Ruisi in Sicily . He worked as an engineer for the M.W. Kellogg Company and then the Socony Mobil Oil Company where he specialized in metallurgy, piping and pressurized tanks for oil.

Patents 
In 1956, Rees received credit for the co-patent of the gas lift.

Spying
According to Rees, he became a "communist sympathizer" during World War II and began supplying oil industry trade secrets to the USSR in 1942. In 1950, he gave the Soviets a newly developed design for a catalytic cracking converter for which he earned a Soviet medal. In addition, he said he supplied Soviet agents with designs for a petroleum plant, natural gas processes and pressurized holding tanks. A newspaper report said he earned $30,000 over the years for providing information. After the FBI approached him about his activities, Rees worked as a double agent for the FBI from 1971 to 1975.

Exposure and death
In 1976, during a three-month-long investigation, the Dallas Times Herald newspaper twice flew Rees to Dallas for interviews. After the investigative journalist Kenneth P. Johnson told Rees that the newspaper planned to print a story that would expose his activity as a double agent, Rees asked Johnson not to run the story or else Rees would commit suicide. Ten hours after the story was published, Rees died from a self-inflicted gunshot wound. In the aftermath, newspapers debated whether the threat of suicide should supersede the right of the journalist to publish the story.

References

1900s births
1976 suicides
1976 deaths
Year of birth uncertain
Espionage in the United States
American spies for the Soviet Union
Federal Bureau of Investigation informants
20th-century American engineers
Suicides by firearm in Texas