omniomni/omni-engineering huggingface dataset:
Conrotatory and disrotatory. In organic chemistry, an electrocyclic reaction can either be classified as conrotatory or disrotatory based on the rotation at each end of the molecule. In conrotatory mode, both atomic orbitals of the end groups turn in the same direction (such as both atomic orbitals rotating clockwise or counter-clockwise).  In disrotatory mode, the atomic orbitals of the end groups turn in opposite directions (one atomic orbital turns clockwise and the other counter-clockwise). The cis/trans geometry of the final product is directly decided by the difference between conrotation and disrotation.

Determining whether a particular reaction is conrotatory or disrotatory can be accomplished by examining the molecular orbitals of each molecule and through a set of rules. Only two pieces of information are required to determine conrotation or disrotation using the set of rules: how many electrons are in the pi-system and whether the reaction is induced by heat or by light. This set of rules can also be derived from an analysis of the molecular orbitals for predicting the stereochemistry of electrocyclic reactions.

Example of a photochemical reaction
Analysis of a photochemical electrocyclic reaction involves the HOMO, the LUMO, and correlations diagrams.

An electron is promoted into the LUMO changing the frontier molecular orbital involved in the reaction.

Example of a thermal reaction
Suppose that trans-cis-trans-2,4,6-octatriene is converted to  under thermal conditions.  Since the substrate octatriene is a "4n + 2" molecule, the Woodward–Hoffmann rules predict that the reaction happens in a disrotatory mechanism.

Since thermal electrocyclic reactions occur in the HOMO, it is first necessary to draw the appropriate molecular orbitals. Next, the new carbon-carbon bond is formed by taking two of the p-orbitals and rotating them 90 degrees (see diagram). Since the new bond requires constructive overlap, the orbitals must be rotated in a certain way. Performing a disrotation will cause the two black lobes to overlap, forming a new bond. Therefore, the reaction with octatriene happens through a disrotatory mechanism.

In contrast, if a conrotation had been performed then one white lobe would overlap with one black lobe.  This would have caused destructive interference and no new carbon-carbon bond would have been formed.

In addition, the cis/trans geometry of the product can also be determined. When the p-orbitals were rotated inwards it also caused the two methyl groups to rotate upwards. Since both methyls are pointing "up", then the product is .

References
 Carey, Francis A.; Sundberg, Richard J.; (1984). Advanced Organic Chemistry Part A Structure and Mechanisms (2nd ed.). New York N.Y.: Plenum Press. .
 March Jerry; (1985). Advanced Organic Chemistry reactions, mechanisms and structure (3rd ed.). New York: John Wiley & Sons, inc. 

Physical organic chemistry
Martin Lo. Martin Wen-Yu Lo is an American mathematician who currently works as a spacecraft trajectory expert at the NASA-owned Jet Propulsion Laboratory. Martin Lo is well known for discovering the Interplanetary Superhighway, also known as the Interplanetary Transport Network. The superhighway is created by combined gravitational forces of several planets that connects planets by a network of “tunnels” and is the most efficient way to navigate the solar system. This continues to be his main area of research.

Biography 
Lo received his Bachelor of Science in mathematics in 1975 from the California Institute of Technology and his PhD in mathematics in 1980 from Cornell University under the supervision of Richard S. Hamilton and George Roger Livesay.

He has been a research scientist in the Navigation and Mission Design Section at the JPL since 1986.

In 2000, Lo, Kathleen Howell, and other scientists from the JPL developed the LTool program to calculate paths near Lagrange points (ITN paths). Compared with previous methods, LTool is capable of predicting orbits up to 50 times faster. They used this tool to calculate the trajectory for the Genesis mission (2001, NASA) trajectory, which took days rather than 8 weeks. The trajectory makes use of gravitational tugs of objects in the way of the spacecraft, ensuring minimal fuel use on the return journey. They called this trajectory the Interplanetary Superhighway. He also designed the trajectory for SpaceDev's SmallTug. LTool was nominated for the Discover Innovation Award. He is the leader of the Lagrange Group, which is an interdisciplinary and international group of researchers and STEM experts from universities, NASA centers, and industry. Their focus is on developing nonlinear astrodynamics techniques with applications to space missions and dynamical astronomy.

Lo appeared in Werner Herzog's film The Wild Blue Yonder in 2005.

Awards and recognition
Martin was awarded the NOGLSTP LGBTQ Scientist of the Year in 2012.

Nominated for a Discover Innovation Award by Discover magazine for work on the Interplanetary Superhighway.

References

External links 
 
 

Living people
20th-century American mathematicians
21st-century American mathematicians
American LGBTQ scientists
California Institute of Technology alumni
Cornell University alumni
Year of birth missing (living people)
G-class landing craft. The G class, or "G-boat" also known as the Marine Alutech Watercat M8 landing craft (, ) is a type of vessel in use by the Finnish Navy and the Swedish Navy. The G-boat was originally designed for the Swedish Navy which ordered about 100 of them. It is primarily used for amphibious landings by, and transportation of, marines. It has a very low draught (approximately 20 cm) at high speeds which makes it ideal for amphibious assault even in shallow waters. It has a cargo capacity of 8 men or one metric ton.

Operators
 Finnish Navy: G 98–99, G 101-G 135
 Swedish Navy 1-100
 Ukrainian Navy: 20 units to be delivered in 2024

See also
Uisko class landing craft
Jurmo class landing craft
Jehu-class landing craft

References

External links 

 Finnish Defence Forces Website of The Finnish Defence Forces
 Marine Alutech Website of Marine Alutech
 

Landing craft
Military boats
Bulk material handling. Bulk material handling is an engineering field that is centered on the design of equipment used for the handling of dry materials. Bulk materials are those dry materials which are powdery, granular or lumpy in nature, and are stored in heaps. Examples of bulk materials are minerals, ores, coal, cereals, woodchips, sand, gravel, clay, cement, ash, salt, chemicals, grain, sugar, flour and stone in loose bulk form. It can also relate to the handling of mixed wastes. Bulk material handling is an essential part of all industries that process bulk ingredients, including: food, beverage, confectionery, pet food, animal feed, tobacco, chemical, agricultural, polymer, plastic, rubber, ceramic, electronics, metals, minerals, paint, paper, textiles and more.

Major characteristics of bulk materials, so far as their handling is concerned, are: lump size, bulk weight (density), moisture content, flowability (particle mobility), angle of repose, abrasiveness and corrosivity, among others.

Bulk material handling systems are typically composed of stationary machinery such as conveyor belts, screw conveyors, tubular drag conveyors, moving floors, toploaders, stackers, reclaimers, bucket elevators, truck dumpers, railcar dumpers or wagon tipplers, shiploaders, hoppers and diverters and various mobile equipment such as loaders, mobile hopper loaders / unloaders, various shuttles, combined with storage facilities such as stockyards, storage silos or stockpiles. Advanced bulk material handling systems feature integrated bulk storage (silos), conveying (mechanical or pneumatic), and discharge.

The purpose of a bulk material handling facility may be to transport material from one of several locations (i.e. a source) to an ultimate destination or to process material such as ore in concentrating and smelting or handling materials for manufacturing such as logs, wood chips and sawdust at sawmills and paper mills. Other industries using bulk materials handling include flour mills and coal-fired utility boilers.

Providing storage and inventory control and possibly material blending is usually part of a bulk material handling system.

In ports handling large quantities of bulk materials continuous ship unloaders are replacing gantry cranes.

Other materials handling classifications (non-bulk)
Non-bulk materials handling classifications include palletization and containerization.

See also

Bulk cargo
Bulk carrier
Caking
Double dump valve
 Materials handling
Rotary car dumper
Self-discharger

References
Rocketplane XP. The Rocketplane XP was a suborbital spaceplane design that was under development c. 2005 by Rocketplane Kistler.  The vehicle was to be powered by two jet engines and a rocket engine, intended to enable it to reach suborbital space. The XP would have operated from existing spaceports in a manner consistent with established commercial aviation practices. Commercial flights were projected to begin in 2009. Rocketplane Global declared bankruptcy in mid-June 2010. Their assets were auctioned off in 2011.

Design and development

As envisioned, the Rocketplane XP would carry a pilot and five passengers on a flight profile from a runway using jet engines like a conventional aircraft.  It would then climb to about 12 km (40,000 feet).  At this point, a reusable rocket engine would power the XP on a suborbital trajectory reaching altitudes of over  after burnout. The XP was to then reenter Earth's atmosphere and land at the same spaceport under conventional jet power.  The relatively low speeds involved meant that heat shielding was not a major concern.  The XP was expected to operate from the Clinton-Sherman Industrial Airpark near Burns Flat, Oklahoma.

On January 24, 2006 Rocketplane Limited announced a Space Act agreement with NASA Johnson Space Center for the loan of a Rocketdyne RS-88 rocket engine for three years, for use in flight tests of the XP vehicle.

See also
 EADS Astrium Space Tourism Project
 Lynx (spacecraft)
 Dream Chaser
 SpaceShipTwo
 Blue Origin New Shepard

References
Notes

Bibliography

 Belfiore, Michael. "It's a Rocket! It's a Plane! It's...Rocket Plane!"  Popular Science, January 8, 2006.
 "Model XP Specifications."  Rocketplane XP, February 21, 2011.

External links
Rocketplane official website
astronautix.com
Video animation - Rocketplane XP concept

Mixed-power aircraft
Rocket-powered aircraft
Spaceplanes
Abandoned civil aircraft projects of the United States
XP
Low-wing aircraft
Softbox. A softbox is a type of photographic lighting modifier, one of a number of photographic soft light devices. All the various soft light types create even and diffused light by transmitting light through some scattering material, or by reflecting light off a second surface to diffuse the light. The best known form of reflective source is the umbrella light, where the light from the bulb is "bounced" off the inside of a metalized umbrella to create an indirect "soft" light.

A softbox is an enclosure around a bulb comprising reflective side and back walls and a diffusing material at the front of the light.  

The sides and back of the box are lined with a bright surface – an aluminized fabric surface or an aluminum foil, to act as an efficient reflector. In some commercially available models the diffuser is removable to allow the light to be used alone as a floodlight or with an umbrella reflector. 

A softbox can be used with either flash or continuous light sources such as fluorescent lamps or "hot lights" such as quartz halogen bulbs or tungsten bulbs. If softbox lights are used with "hot" light sources, the photographer must be sure the softbox is heat rated for the wattage of the light to which it is attached in order to avoid fire hazard.

Types of softbox

See also
 Beauty dish
 Light tent
 Reflector (photography)
 Speed ring
 Striplight

References

Photography equipment
Photographic lighting
AGARD. The Advisory Group for Aerospace Research and Development (AGARD) was an agency of NATO that existed from 1952 to 1996.

AGARD was founded as an Agency of the NATO Military Committee. It was set up in May 1952 with headquarters in Neuilly sur Seine, France.

In a mission statement in the 1982 History it published, the purpose involved "bringing together the leading personalities of the NATO nations in the fields of science and technology relating to aerospace".
The Advisory Group was organized by panels:
Aerospace medical, avionics, electromagnetic wave propagation, flight mechanics, fluid dynamics, guidance and control, propulsion and energetics, structures and materials, and technical information.
In 1958 Theodore von Kármán hired Moe Berg to accompany him to the AGARD conference in Paris. "AGARD's aim was to encourage European countries to develop weapons technology on their own instead of relying on the U.S. defense industry to do it for them."

Activities
There were annual meetings, frequently in Paris, but also in Delft, Turin, Cambridge, Washington DC.
The Advisory Group administered a consultant and exchange program including lecture series and technical panels.

The AGARD publishing program included a multilingual aeronautical dictionary, about ninety titles per year, with a normal run of 1200. An Agardograph is a work prepared by, or on behalf of, AGARD's panels. For example, an agardograph on the AGARD-B wind tunnel model was prepared.

Later examples of AGARD studies include such topics as non-lethal weapons, theatre ballistic missile defence, protection of large aircraft in peace support operations, and limiting collateral damage caused by air-delivered weapons. AGARD was also one of the first NATO organizations to cooperate with Russia in a mutual exchange of information dealing with flight safety.

AGARD merged with the NATO Defence Research Group (DRG) in 1996 to become the NATO Research and Technology Organisation (RTO).

See also
Aeronautics

Notes

Further reading

 Theodore von Kármán with Lee Edson (1967) The Wind and Beyond: Theodore von Kármán Pioneer in Aviation and Pathfinder in Space: Little, Brown and Company
 The AGARD History 1952-1987 (1999), Advisory Group for Aerospace Research & Development,

External links
 Science and Technology Organization (STO)

Aeronautics organizations
Aerospace engineering organizations
Military technology
NATO agencies
Scientific organizations based in France
Zheng Guo. Zheng Guo (fl. third century BCE) was a Chinese hydraulic engineer who lived towards the end of the Warring States period. He is best known for designing the Zhengguo Canal, which was named after him.

Life
Zheng Guo was from the Han state. In the third century BCE, near the end of the Warring States period, the Qin state in western China was making aggressive advances towards the other six major states in the east. The Han state, which shared borders with the Qin state, heard that the Qin state liked to carry out large-scale construction works and projects, so they sent Zheng Guo to persuade the Qin state to build a canal connecting the Jing and Luo rivers to irrigate the Guanzhong plain and boost agricultural productivity. The plan was actually meant to distract the Qin state and keep it busy, so as to prevent it from attacking the other states.

During the construction phase, the Qin state discovered Zheng Guo's ulterior motive in asking them to build the canal, and wanted to execute him. However, Zheng Guo said, "I started as a spy working for the Han state, but once the canal is built, it is beneficial to the Qin state. Although I can prolong the Han state's existence by doing this, at the same time I am also helping the Qin state make a great achievement worthy of history." The Qin state agreed and ordered him to finish building the canal. Once completed, the canal and its irrigation works largely boosted agricultural productivity in the Qin state.

In manga Kingdom, he was referred as "The man who solved the Qin problem of flooding".

References

Further reading
 Sima, Qian (c. 94 BCE). Records of the Grand Historian (Shi Ji).
 Ban, Gu, Ban, Zhao, and Ban, Biao (c. 111 CE). Book of Han (Han Shu).

3rd-century BC Chinese people
Chinese canal engineers
Chinese hydrologists
Engineers from Henan
People of Han (Warring States)
Hydraulic engineers
Irrigation engineers
Qin (state)
Year of birth unknown
Year of death unknown
Deified Chinese men
Yellow River management
Nanosocialism. Nanosocialism refers generally to a set of economic theories of social organization advocating state or collective ownership and administration of the research, development and use of nanotechnology.

Politics 

Nanosocialism is a stance that favors participatory politics to guide state intervention in the effort to manage the transition to a society revolutionized by molecular nanotechnology.

"Nanosocialism" is a term coined by David M. Berube, the associate director of Nanoscience and Technology Studies at the USC NanoCenter, who argues that nanotechnological projections need to be tempered by technorealism about the implications of nanotechnology in a technocapitalist society, but that its applications also offer enormous opportunities for economic abundance and social progress.

In popular culture

In the role-playing game Transhuman Space, nanosocialism is described as a descendant of "infosocialism", in which intellectual property is nationalized and freely distributed by the state. It is adopted by some developing nations to counter the hold corporations from wealthier nations have on copyrights and patents. This fictional version of nanosocialism was coined by David L. Pulver, the game's creator, who was unaware that the term had already been used by Berube.

See also
 Post-scarcity economy

References

Socialism
Political neologisms
Technology neologisms
Technology in society
Nanotechnology
Political science terminology
Technological utopianism
IIC. IIC may refer to 
 Itahari International College, IT and Business college in Morang, Nepal.
 Apple IIc, a personal computer introduced by Apple Computer in April 1984
 Institute of Informatics and Communication, University of Delhi South Campus
 I²C, Inter-Integrated Circuit, a serial computer bus
 Impact insulation class, a method of determining how effective a floor structure is to footfall noise
 Independent Inquiry Committee, a UN committee commissioned with investigating alleged corruption and fraud in the Oil-for-Food Programme
 India International Centre, New Delhi, India
 Industrial Internet Consortium, founded in 2014 to further development, adoption and widespread use of interconnected machines, intelligent analytics and people at work.
 Instituto de Ingeniería del Conocimiento The Knowledge Engineering Institute (CII) is a Spanish research, development and innovation center located on the campus of Universidad Autonoma de Madrid (UAM)
 International Institute for Conservation, the global membership organisation for conservation professionals
 International Review of Intellectual Property and Competition Law, a publication in intellectual property law
 Israeli Intelligence Community
 Istituto Italiano di Cultura, an Italian Cultural Institute of the Italian Ministry of Foreign Affairs

See also
 2C (disambiguation), including a list of topics named II-C, etc.
Solid-state nuclear track detector. A solid-state nuclear track detector or SSNTD (also known as an etched track detector or a dielectric track detector, DTD) is a sample of a solid material (photographic emulsion, crystal, glass or plastic) exposed to nuclear radiation (neutrons or charged particles, occasionally also gamma rays), etched in a corrosive chemical, and examined microscopically. When the nuclear particles pass through the material they leave trails of molecular damage, and these damaged regions are etched faster than the bulk material, generating holes called tracks.

The size and shape of these tracks yield information about the mass, charge, energy and direction of motion of the particles. The main advantages over other radiation detectors are the detailed information available on individual particles, the persistence of the tracks allowing measurements to be made over long periods of time, and the simple, cheap and robust construction of the detector. For these reasons, SSNTDs are commonly used to study cosmic rays, long-lived radioactive elements, radon concentration in houses, and the age of geological samples.

The basis of SSNTDs is that charged particles damage the detector within nanometers along the track in such a way that the track can be etched many times faster than the undamaged material. Etching, typically for several hours, enlarges the damage to conical pits of micrometer dimensions, that can be observed with a microscope. For a given type of particle, the length of the track gives the energy of the particle. The charge can be determined from the etch rate of the track compared to that of the bulk. If the particles enter the surface at normal incidence, the pits are circular; otherwise the ellipticity and orientation of the elliptical pit mouth indicate the direction of incidence.

A material commonly used in SSNTDs is polyallyl diglycol carbonate (also known as CR-39). It is a clear, colorless, rigid plastic with the chemical formula C12H18O7. Etching to expose radiation damage is typically performed using solutions of caustic alkalis such as sodium hydroxide, often at elevated temperatures for several hours.

See also
nuclear track detectors that are not solid state
cloud chamber
bubble chamber
solid-state (semiconductor) nuclear detectors that do not record tracks
surface-barrier detector
silicon drift detector
lithium-drifted silicon detector - Si(Li)
intrinsic detector

External links
 Gregory Choppin, Jan-Olov Liljenzin, Jan Rydberg Radiochemistry and Nuclear Chemistry, Chapter 8, "Detection and Measurement Techniques"

Nuclear physics
Particle detectors