omniomni/omni-engineering huggingface dataset:
Pentane interference. Pentane interference or syn-pentane interaction is the steric hindrance that the two terminal methyl groups experience in one of the chemical conformations of n-pentane. The possible conformations are combinations of anti conformations and gauche conformations and are anti-anti, anti-gauche+, gauche+ - gauche+ and gauche+ - gauche− of which the last one is especially energetically unfavorable. In macromolecules such as polyethylene pentane interference occurs between every fifth carbon atom. The 1,3-diaxial interactions of cyclohexane derivatives is a special case of this type of interaction, although there are additional gauche interactions shared between substituents and the ring in that case. A clear example of the syn-pentane interaction is apparent in the diaxial versus diequatorial heats of formation of cis 1,3-dialkyl cyclohexanes. Relative to the diequatorial conformer, the diaxial conformer is 2-3 kcal/mol higher in energy than the value that would be expected based on gauche interactions alone.  Pentane interference helps explain molecular geometries in many chemical compounds, product ratios, and purported transition states. One specific type of syn-pentane interaction is known as 1,3 allylic strain or (A1,3 strain).

For instance in certain aldol adducts with 2,6-disubstituted aryl groups the molecular geometry has the vicinal hydrogen atoms in an antiperiplanar configuration both in a crystal lattice (X-ray diffraction) and in solution proton (NMR coupling constants)  normally reserved for the most bulky groups i.d. both arenes:

The other contributing factor explaining this conformation is reduction in allylic strain by minimizing the dihedral angle between the arene double bond and the methine proton.

Syn-pentane interactions are responsible for the backbone-conformation dependence of protein side chain rotamer frequencies and their mean dihedral angles, which is evident from statistical analysis of protein side-chain rotamers in the Backbone-dependent rotamer library.

References

Stereochemistry
Magnesium perchlorate. Magnesium perchlorate is a powerful oxidizing agent, with the formula Mg(ClO4)2. The salt is also a superior drying agent for gas analysis.

Magnesium perchlorate decomposes at 250 °C. The heat of formation is -568.90 kJ/mol.

The enthalpy of solution is quite high, so reactions are done in large amounts of water to dilute it.

It is sold under the trade name anhydrone. Manufacture of this product on a semi-industrial scale was first performed by G. Frederick Smith in his garage in Urbana Illinois, but later at a permanent facility in Columbus, OH called G. Frederick Smith Chemical Co. He sold the magnesium perchlorate to A. H. Thomas Co., now Thomas Scientific, under the trade name Dehydrite.

Uses
It is used as desiccant to dry gas or air samples, but is no longer advised, for use as a general desiccant, due to hazards inherent in perchlorates. It is dried by heating at 220 °C under vacuum.

Magnesium perchlorate and other perchlorates have been found on Mars. Being a drying agent, magnesium perchlorate retains water from the atmosphere and may release it when conditions are favorable and temperature is above 273 K. Briny solutions that contain salts such as magnesium perchlorate have a lower melting point than that of pure water. Therefore the abundance of magnesium and other perchlorate salts on Mars could support the theory that liquid aqueous solutions might exist on or below the surface, where temperature and pressure conditions would ordinarily cause the water to freeze.

Production
Magnesium perchlorate is produced by the reaction of magnesium hydroxide and perchloric acid.

References

Perchlorates
Magnesium compounds
Sprinter. Sprinter can refer to:

In sport 
 A participant in sprint (running)
 Sprinter (cycling), a type of racing cyclist
 Sprint train, a group of road bicycle racers who at the end of a race work together to set a high pace to help their sprinter
 A sprint car racing vehicle

Motor vehicles 
 Mercedes-Benz Sprinter (or 'Dodge Sprinter', 'Freightliner Sprinter'), a cargo van
 Toyota Sprinter, a compact car

Trains

Units
 Sprinter (British Rail), a family of diesel multiple units built for British Rail in the 1980s
 NS SGMm (Stadsgewestelijk Materieel), a Dutch electric multiple unit in service since 1975, commonly referred to as "Sprinter old generation"
 NS Sprinter Lighttrain, a Dutch electric multiple unit in service since 2009
 Sprinter New Generation, a Dutch train manufactured by Construcciones y Auxiliar de Ferrocarriles
 V/Line Sprinter, a diesel multiple unit operated by V/Line in Australia

Rail services
 Sprinter (rail service), a hybrid rail service in San Diego County, California
 Sprinter (Nederlandse Spoorwegen), rail service type in the Netherlands
 ICE Sprinter, a variant of the Intercity Express rail service type operated in Germany

Other 
 Sprinter (computer), a Russian microcomputer
 Sprinter (album), by Torres (Mackenzie Scott), 2015 
 "Sprinter" (song), a 2023 song by British rappers Dave and Central Cee
 Sprinter (film), a 2018 sports drama directed by Storm Saulter
 Sprinter (manga), written and illustrated by Yū Koyama

See also 
 Sprint (disambiguation)
Ingenio. Ingenio may refer to:

Portuguese
 Engenho, a word meaning "ingenious" or "mill".

Spanish "sugar mill"
Ingenio, Las Palmas  municipality in the eastern part of the island of Gran Canaria
Valle de los Ingenios, also named Valley de los Ingenios or Valley of the Sugar Mills
Ingenio La Trinidad, Tucumán settlement in northern Argentina
Ingenio River
Ingenio District

Latin "ingenuity"
Ingenio et Arti (from Latin: For Spirit and Art) Danish medal awarded to prominent Danish and foreign scientists and artists.
Ingenio (satellite)
Caterpillar 740 Ejector. The Caterpillar 740 Ejector Articulated Truck is Caterpillar's second generation of articulated haulers (dump truck) to have a system that pushes material out the back of the body.  It is the largest articulated haul truck offered by Caterpillar; larger trucks use a rigid frame system.  The ejector uses a 4-cylinder hydraulic ram and blade to dump the material out, a similar system to Cat's wheel tractor-scrapers.  The 740 Ejector is sold as separate model from the usual 740.

Total power is 436 hp (325 kW), total operating weight is 162,280 lb (73,610 kg), with the load being 42 short tons (38 tonnes), 37.3 yd3 (28.5 m3) at a 1:1 heap. Top forward speed is 34 mph (55 km/h).

History 
Caterpillar introduced an ejector version of its D400E in 2001.  In 2002/2003, the DX00 series of trucks were replaced with the 7XX range.  Currently Caterpillar supplies 725, 730, 730 Ejector, 735, 740 and 740 Ejector versions.  The 7XX truck series uses the same cab design across all types. These are all manufactured in the UK.

Advantages and disadvantages 
Advantages
 Lower risk of tipping over on slopes when dumping.
 Ability to spread the material out over a distance.
 Dumping does not increase the risk of contacting overhead obstacles (power lines, bridges, etc.).
 Virtually eliminate any material remaining in the body after dumping.
 Dumping and returning can be done without slowing down.

Disadvantages
 Reduction in types of materials suited for hauling, large rocks can wedge between sidewall and ejector causing damage.
 Winter operations may cause wet material to freeze on sidewall jamming ejector.
 More complicated operation, additional parts to maintain.
 Body can be damaged from contact while loading, preventing ejection.

External links 
Caterpillar 740 Ejector - Official Caterpillar website
 Ejector system (image from manufacturer website)
Magazine Article in Earthmovers Magazine about Maveric Contractors Caterpillar 740 Ejectors

740 Ejector
Yuan Ze University. Yuan Ze University (YZU; ) is a private university located in Taoyuan City, Taiwan. Established in 1989, YZU campus is in Zhongli District, Taoyuan; Taipei; and Bade District, Taoyuan.

Yuan Ze has five colleges, Engineering (accredited by IEET), Informatics, Management (accredited by AACSB and AAPBS), Humanities and Social Sciences, and Electrical and Communication Engineering (accredited by IEET). With over 8,000 students with a 2:1 ratio between undergraduate and graduate students on campus, YZU offers several international programs such as the English Program of Bachelor of Business Administration, Master’s Program in Industrial Engineering and Management. Additionally, the Master’s Programs in Communication Engineering are all taught in English.

Presidents 

 Wang Kuo-Ming (王國明): August 1989 – July 1999
 Chan Shih-Hung (詹世弘): August 1999 – July 2005
 Perng Tsong-Pyng (彭宗平): August 2005 – July 2012
 Chang Jin-Fu (張進福): August 2012 – July 2015
 Hsu Tze-Chi (徐澤志): August 2015 – January 2016
 Wu Jyh-Yang (吳志揚): February 2016 – January 2022
 Liao Ching-Jong (廖慶榮): February 2022 – present

Recognitions and awards 
Yuan Ze ranked 1501+ in Times Higher Education World University Rankings 2023. In 2023, the university ranked 401–500 in the Times Higher Education Young University Ranking.

 2018   Ranked Times Higher Education Asia University top 200
 2017   Ranked QS Asia University top 210
 2016   Ranked 132, the BRICS and Emerging Economics University, Times Higher Education
 2015   Ranked QS Asia University top 250
 2014  Continuous winning for Teaching Excellence Project for 10 years
 2014   Ranked Times Higher Education Asia University top 100
 2013   Ranked 71st by the Asia University Ranking 2013, Times Higher Education
 2010   3 areas “Electrical Engineering”, “Computer  Science”, “Chemical Engineering” ranked in the top 200 in the world
 2010   One of the 11 Universities in Taiwan ranked in the top 300 in the world in the area of Computing & Technology Engineering
 2008   Teaching Excellence grant from MOE
 2008   Fuel Cell Research Center selected as a Center of Excellence by MOE
 2005   Top-University grant from MOE (Recognized as one of the top 12 universities in Taiwan)
 2004   Teaching Excellence grant from MOE

See also
 List of universities in Taiwan

References

External links 

1989 establishments in Taiwan
Educational institutions established in 1989
Universities and colleges in Taoyuan City
Zhongli District

Universities and colleges in Taiwan
Comprehensive universities in Taiwan
Xihoumen Bridge. The Xihoumen Bridge () is a suspension bridge on the Zhoushan Archipelago, the largest offshore island group in China.

Linking Jintang and Cezi islands, the bridge, together with the 27-kilometer cable-stayed Jintang Bridge linking Jintang and Zhenhai in the neighboring city of Ningbo, is part of the second and last phase of a bridging project started in 1999 to connect the Zhoushan Archipelago to the mainland via five bridges. The bridge forms part of the Yongzhou Expressway.

Built by the province of Zhejiang at a cost of 2.48 billion yuan (approximately US$363 million), construction began in 2005 and the main span was completed in December 2007. The bridge was opened to traffic on a test basis on 25 December 2009, at 11:58 p.m., local time alongside the Jintang Bridge, before it is officially open for traffic. The opening date was delayed due to a ship collision on 16 November 2009 that slightly damaged the side of Jintang Bridge.

The 5.3-kilometre suspension bridge connection has a 2.6-kilometre main bridge with a central span of 1,650 metres. The approaches total 2.7 kilometres. When built, it was the second-longest suspension bridge ranked by the length of the centre span after the Akashi Kaikyō Bridge in Japan.

See also
 List of bridges in China
 List of longest suspension bridge spans

Notes

External links

 Xihoumen bridge images and location at Google Earth

 diagrams and artist's depiction
 Official announcement in People's Daily

Suspension bridges in China
Bridges completed in 2007
Bridges in Zhoushan
Cross-sea bridges in China
Gmelinite. Gmelinite-Na is one of the rarer zeolites but the most common member of the gmelinite series, gmelinite-Ca, gmelinite-K and gmelinite-Na.  It is closely related to the very similar mineral chabazite. Gmelinite was named as a single species in 1825 after Christian Gottlob Gmelin (1792–1860) professor of chemistry and mineralogist from Tübingen, Germany, and in 1997 it was raised to the status of a series.Gmelinite-Na has been synthesised from Na-bearing aluminosilicate gels.  The naturally occurring mineral forms striking crystals, shallow, six sided double pyramids, which can be colorless, white, pale yellow, greenish, orange, pink, and red. They have been compared to an angular flying saucer.

Structure 

The aluminosilicate framework is composed of tetrahedra linked to form parallel double six-membered rings stacked in two different positions (A and B) in the repeating arrangement AABBAABB.  The framework has no Al-Si order.  Within the structure there are cavities with a cross-section of up to 4 Å, and also wide channels parallel to the c axis with a diameter of 6.4 Å. Space group: P63/mmc.  Unit cell parameters: a=13.72 Å, c=9.95 Å, Z=4.

Environment 

Generally occurs in Si-poor volcanic rocks, marine basalts and breccias, associated with other sodium zeolites such as analcime, , natrolite, , and chabazite-Na, .  It also occurs in Na-rich pegmatites in alkaline rocks, and as an alteration product in some nepheline syenite intrusions.  No sedimentary gmelinite has been found.  It is generally assumed that it forms at low temperatures, less than 100 °C. It is widespread as a hydrothermal alteration product of ussingite, , associated with gobbinsite, , gonnardite, , and chabazite-K.

Notable localities 
 
Gmelinite-Na occurs extremely rarely at the Francon Quarry, Montreal, Canada, in sills of the igneous volcanic rock phonolite which are rich in dawsonite, . It occurs both as pure gmelinite-Na and interlayered with chabazite in water-quenched basalts in Western Tasmania.

Associated minerals include other zeolites, especially chabazite, quartz, aragonite and calcite.

Distribution 
Type Locality: Monte Nero, San Pietro, Montecchio Maggiore, Vicenza Province, Veneto, Italy.  Also found in Australia, Canada, Czech Republic, Germany, Hungary, Japan, Russia, UK and US.

References

External links 
Structure type GME
Mineral galleries
Mindat

Sodium minerals
Calcium minerals
Aluminium minerals
Zeolites
Hexagonal minerals
Minerals in space group 194
Minerals described in 1825
Ravine. A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. Ravines may also be called a cleuch, dell, ghout (Nevis), gill or ghyll, glen, gorge, kloof (South Africa), and chine (Isle of Wight)

A ravine is generally a fluvial slope landform of relatively steep (cross-sectional) sides, on the order of twenty to seventy percent in gradient. Ravines may or may not have active streams flowing along the downslope channel which originally formed them; moreover, often they are characterized by intermittent streams, since their geographic scale may not be sufficiently large to support a perennial stream.

Definition
According to Merriam-Webster, a ravine is "a small, narrow, steep-sided valley that is larger than a gully and smaller than a canyon and that is usually worn by running water". Some societies and languages do not differentiate between a gully and ravine; in others, there is a distinction, particularly when concerning environmental management.

Formation
Gullies are often found in hilly or mountainous regions, where water runoff is guided downhill by steep slopes and over time erodes the landscape. A ravine is the final step in gully erosion, formed when a stream has eroded so severely it forms a deep cut in the earth. A gully can be classified as a ravine after it reaches a large depth, typically in excess of .

Environmental impact

Ravine erosion contributes heavily to land loss globally and particularly threatens agricultural lands. Additionally, soil loss contributes to pollution, flooding, and sedimentation of waterways. The formation of ravine lands can be sped up by deforestation and overgrazing. In Indian badlands, soil erosion is estimated to exceed a rate of  annually.

Examples

Hawaii
The shield volcanoes of Hawaii have significant impact on the distribution of ravines across the islands, specifically Mauna Loa and Mauna Kea, the former of which is one the most active shield volcanoes on Earth. Both of these volcanoes show V-shaped ravines on their flanks, solely where they have been mantled by Pahala ash. Being the older of the two, Mauna Kea displays more pronounced dissection of these ravines. Rainfall and infiltration capacity are critical to valley initiation on the Hawaiian volcanoes. Once these valleys are initiated, their streams incise to form V-shaped ravines. Eventually, they become sufficiently deep ravine systems and expose groundwater activity. The deepest of these incisions are U-shaped, theatre-headed valleys.

Notable ravines

 Babi Yar, Ukraine
 Bam Bam Amphitheaters, Gabon
 Barranco de Badajoz, Spain
 Barranco del Infierno, Spain
 Gravina Ravine, Italy
 Moola Chotok, Pakistan
 Ravenna Park, United States
 Rauðfeldsgjá, Iceland
 Stuðlagil, Iceland
 Taishaku Valley, Japan
 Toronto ravine system, Canada

References

Citations

Bibliography

External links

Erosion landforms
Fluvial landforms
Slope landforms
 
Oronyms
Project Genoa. Project Genoa was a software project commissioned by the United States' DARPA which was designed to analyze large amounts of data and metadata to help human analysts counter terrorism.

Program synopsis
Genoa's primary function was intelligence analysis in order to assist human analysts.

The program was designed to support both top-down and bottom-up approaches; a policy maker could hypothesize a possible attack and use Genoa to look for supporting evidence of such a plot, or it would compile pieces of intelligence into a diagram and suggest possible outcomes. Human analysts would then be able to modify the diagram to test various cases.

Companies such as Integral Visuals, Saffron Technology, and Syntek Technologies were involved in Genoa's development. It cost a total of $42 million to complete the program.

History
Genoa was conceived in late 1995 by retired Rear Admiral John Poindexter, a chief player in the Iran-Contra Affair. At the time, Poindexter was working at Syntek, a company often contracted to do work for the Department of Defense. He proposed a computer system that would help humans crunch large amounts of data in order to more effectively predict potential national security threats. Poindexter brought his ideas to former colleagues working with the United States National Security Council.

That year, a team of researchers was assembled for the project and began studying various historical events to which Genoa could be applied. The Tokyo subway sarin attack in March was the primary focus. Instead of analyzing the attack itself, the researchers looked into the history of Aum Shinrikyo, the group that perpetrated the attack, to find evidence that could have suggested their intentions.

In order to pitch their ideas, the researchers set up a mock crisis command center in DARPA's main building, full of monitors staffed by actors. An audience would watch as a fictitious scenario would unfold before them, guided along by an animated video segment. Poindexter called the presentation "A Day in the Life of an Analyst." Another mock center was set up near the DARPA building with the help of a Hollywood set designer to serve the same purpose. Prominent viewers of the exhibition included Richard A. Clarke, John Michael McConnell, and James R. Clapper.

Genoa was commissioned in 1996 for development overseen by DARPA and completed in the 2002 fiscal year, becoming a component of the Total Information Awareness program. It was concluded that while Genoa helped officials better understand complex situations, it operated at a slow speed. The research initiated by the project was continued in its immediate follow-on program, Genoa II. One of the goals of this successor was to increase the speed of analyses.
 
The program was actively utilized by the Defense Intelligence Agency.

References

External links
 https://web.archive.org/web/20081125153748/http://www.darpa.mil/darpatech99/Presentations/isopdf/isotia.pdf

DARPA
Mass surveillance
Military computers
SX-Window. SX-Window is a graphic user interface (GUI) operating system for the Sharp X68000 series of computers, which were popular in Japan. It was first released in 1989 and had its last update in 1993. It runs on top of the Human68k disk operating system, similarly to how Windows 3.1 runs on top of MS-DOS.

History
SX-Window was introduced for X68000 in 1989, and came preinstalled on the X68000 EXPERT model. It was developed by Hudson. The final release was 3.1 in 1993. In 2000, Sharp released the system software for the X68000 free-of-charge, including SX-Window.

Technical details
The look and feel of the GUI is like that of the NeXTSTEP operating system, and its API is similar to the Macintosh Toolbox. It uses non-preemptive multitasking with the event-driven paradigm. It has a garbage collection system without MMU of MPU, but it was difficult to program because all pointers derived from handles become invalid once any API is called. The X68000 was very powerful for game software, but this GUI could be slow, as no hardware acceleration card was supported. Only a few applications and games were developed for this system.

References

Windowing systems
Glomar Challenger. The Glomar Challenger was a deep-sea research and scientific drilling vessel designed for oceanography and marine geology studies. It was used in the Deep Sea Drilling Project for obtaining sediment cores from the ocean floor. 

The drillship was designed, owned, and operated by Global Marine Incorporated (now Transocean) specifically for a long term contract with the American National Science Foundation and University of California Scripps Institution of Oceanography. It was built by Levingston Shipbuilding Company in Orange, Texas and launched on March 23, 1968.

Glomar is a truncation of Global Marine, while the name Glomar Challenger is a tribute to the 19th century oceanographic survey vessel .

Purpose  
The Glomar Challenger was built to help Harry Hess test the theory of seafloor spreading, which predicts that the age of rock samples increases with distance from the mid-ocean ridge.

Accomplishments 
Starting from August 1968, the ship was embarked on a 15-year-long scientific expedition, the Deep Sea Drilling Project, criss-crossing the Mid-Atlantic Ridge between South America and Africa and drilling core samples at specific locations. When the age of the samples was determined by paleontologic and isotopic dating studies, this provided conclusive evidence for the seafloor spreading hypothesis, and, consequently, for plate tectonics.

During 1970, when doing research in the Mediterranean Sea while supervised by Kenneth Hsu, geologists aboard the vessel brought up drill cores containing gypsum, anhydrite, rock salt, and various other evaporite minerals that often form from drying of brine or seawater. These were the first solid evidence for the ancient desiccation of the Mediterranean Sea, the Messinian salinity crisis.

Fate and legacy 
In November 1983, after 15 years in operation, the Glomar Challenger'''s active duty ended, and she was later scrapped. Her successor, JOIDES Resolution, was launched in 1985. 

See also
 Glomar Explorer''
 Integrated Ocean Drilling Program
 Glomar Challenger Basin
 Scientific drilling
 Offshore drilling
 Continental drift
 List of research vessels by country

References
Notes

Bibliography
  (About the campaign that discovered the salt residues under the Mediterranean.)

External links 

 Glomar Challenger: Drillship of the Deep Sea Drilling Project
  Ships of the World: Glomar Challenger 
 USGS CMG Platform (Glomar Challenger) Data and Metadata

Research vessels of the United States
1968 ships
Ships built in Orange, Texas