omniomni/omni-engineering huggingface dataset:
Concrete step barrier. A concrete step barrier is a safety barrier used on the central reservation of motorways and dual carriageways as an alternative to the standard steel crash barrier.

United Kingdom

With effect from January 2005 and based primarily on safety grounds, the UK National Highways policy is that all new motorway schemes are to use high-containment concrete barriers in the central reserve. All existing motorways will introduce concrete barriers into the central reserve as part of ongoing upgrades and through replacement when these systems have reached the end of their useful life. This change of policy applies only to barriers in the central reserve of high-speed roads and not to verge-side barriers. Other routes will continue to use steel barriers. Government policy ensures that all future crash barriers in the UK will be made of concrete unless there are overriding circumstances.

Ireland
The usage of the concrete step barrier has become widespread in Ireland. As of 2017,  of motorways use this barrier. Some motorways such as parts of the M8 and M6 have had the crash barrier since their original construction. Other motorways had it installed as part of their upgrade (M50).

Hong Kong 
Steel guard rails (since 2000s as thrie-beam barrier) and concrete profile barrier are the barrier systems used in expressways in the territory. The designs of their beam barrier are based in American and Australian designs and concrete based in European standards.

Degradation processes

Various types of aggregate may undergo chemical reactions in concrete, leading to damaging expansive phenomena. The most common are those containing reactive silica, that can react with the alkalis in concrete. Amorphous silica is one of the most reactive mineral components in some aggregates containing e.g., opal, chalcedony, flint. Following the alkali-silica reaction (ASR), an expansive gel can form, that creates extensive cracks and damage on structural members.

See also 
 Jersey barrier
 Constant-slope barrier
 F-shape barrier
 Road-traffic safety
 Traffic barrier

References 

Concrete
Road safety
Protective barriers
Dynamic Analysis and Replanning Tool. The Dynamic Analysis and Replanning Tool, commonly abbreviated to DART, is an artificial intelligence program used by the U.S. military to optimize and schedule the transportation of supplies or personnel and solve other logistical problems.

DART uses intelligent agents to aid decision support systems located at the U.S. Transportation and European Commands. It integrates a set of intelligent data processing agents and database management systems to give planners the ability to rapidly evaluate plans for logistical feasibility. By automating evaluation of these processes DART decreases the cost and time required to implement decisions.

DART achieved logistical solutions that surprised many military planners. Introduced in 1991, DART had by 1995 offset the monetary equivalent of all funds DARPA had channeled into AI research for the previous 30 years combined.

Development and introduction
DARPA funded the MITRE Corporation and Carnegie Mellon University to analyze the feasibility of several intelligent planning systems. In November 1989, a demonstration named The Proud Eagle Exercise indicated many inadequacies and bottlenecks within military support systems. In July, DART was previewed to the military by BBN Systems and Technologies and the ISX Corporation (now part of Lockheed Martin Advanced Technology Laboratories) in conjunction with the United States Air Force Rome Laboratory.  It was proposed in November 1990, with the military immediately demanding that a prototype be developed for testing. A rapid development cycle allowed for a prototype to be developed in eight weeks, which was introduced in 1991 to the USTRANSCOM at the beginning of Operation Desert Storm during the Gulf War.

Impact
Directly following its launch, DART solved several logistical nightmares, saving the military millions of dollars. Military planners were aware of the tremendous obstacles facing moving military assets from bases in Europe to prepared bases in Saudi Arabia, in preparation for Desert Storm. DART quickly proved its value by improving upon existing plans of the U.S. military. What surprised many observers was DART's ability to adapt plans rapidly in a crisis environment.

DART's success led to the development of other military planning agents such as:
RDA - Resource Description and Access system
DRPI - Knowledge-Based Planning and Scheduling Initiative, a successor of DART

See also
 Military logistics
 JADE (planning system)

References

Military logistics of the United States
Automated planning and scheduling
Common Lisp (programming language) software
Mitre Corporation
The Complete Book of Outer Space. The Complete Book of Outer Space is a 1953 collection of essays about space exploration edited by Jeffrey Logan. It first appeared as a magazine, published by Maco Magazine Corp. The first book publication was by Gnome Press in 1953 in an edition of 3,000 copies.

Contents
 Preface, by Kenneth MacLeish
 "A Preview of the Future: Introduction", by Jeffrey Logan
 "Development of the Space Ship", by Willy Ley
 "Station in Space", by Wernher von Braun
 "Space Medicine", by Heinz Haber
 "Space Suits", by Donald H. Menzel
 "The High Altitude Program", by Robert P. Haviland
 "History of the Rocket Engine", by James H. Wyld
 "Legal Aspects of Space Travel", by Oscar Schachter
 "Exploitation of the Moon", by Hugo Gernsback
 "Life Beyond the Earth", by Willy Ley
 "Interstellar Flight", by Leslie R. Shepard
 "The Spaceship in Science Fiction", by Jeffrey Logan
 "Plea for a Coordinated Space Program", by Wernher von Braun
 "The Flying Saucer Myth", by Jeffrey Logan
 "The Panel of Experts"
 "Chart of the Moon Voyage"
 "Chart of the Voyage to Mars"
 "Timetables and Weights"
 "A Space Travel Dictionary"

Reception
Groff Conklin of Galaxy Science Fiction said in 1954 that The Complete Book of Outer Space was "a fascinating collection" of pictures and text "of varying value ... but generally an exciting one".

References

Sources

1953 books
Spaceflight books
Gnome Press books
The Robot and the Man. The Robot and the Man is a 1953 anthology of science fiction short stories regarding robots edited by Martin Greenberg.  The stories originally appeared in the magazines Astounding SF and Galaxy Science Fiction.

Contents
 Foreword, by Martin Greenberg
 "The Mechanical Answer", by John D. MacDonald
 "Self Portrait", by Bernard Wolfe
 "Deadlock", by Lewis Padgett
 "Robinc", by Anthony Boucher using his H. H. Holmes pseudonym
 "Burning Bright", by Robert Moore Williams using his John S. Browning pseudonym
 "Final Command", by A. E. van Vogt
 "Though Dreamers Die", by Lester del Rey
 "Rust", by Joseph E. Kelleam
 "Robots Return", by Robert Moore Williams
 "Into Thy Hands", by Lester del Rey

Reception
P. Schuyler Miller reported that "the theme hangs together very well," with some "whittling" by the editor to make the stories seem more consistent. He noted that many of the better stories regarding robots had already been anthologized elsewhere.

References

1953 anthologies
Science fiction anthologies
Gnome Press books
Robots in literature
Mocmex. Mocmex is a trojan, which was found in a digital photo frame in February 2008. It was the first serious computer virus on a digital photo frame. The virus was traced back to a group in China.

Overview 
Mocmex collects passwords for online games. The virus is able to recognize and block antivirus protection from more than a hundred security companies and the Windows built-in firewall. Mocmex downloads files from remote locations and hides randomly named files on infected computers. Therefore, the virus is difficult to remove. Furthermore, it spreads to other portable storage devices that were plugged into an infected computer. Industry experts describe the writers of the Trojan Horse as professionals and describe Mocmex as a "nuclear bomb of malware".

Protection 
Though Mocmex can be described as a serious virus, protection is not hard. First of all, updated antivirus programs will recognize Mocmex' signature and quarantine it. Another precaution is to check a digital photo frame for malware on a Macintosh or Linux machine before plugging it into a computer with Windows, or disable autorun on Windows.

Effects 
A large part of digital photo frames were manufactured in China, particularly in Shenzhen. The negative publicity followed by media reports of the Chinese virus is expected to have negative effects on Chinese manufacturers. Mocmex happened just a few months after quality problems with toys manufactured in China raised the attention of Western countries leading to a low quality image for Chinese products.

References 

Digital photography
Display technology
Trojan horses
Hacking in the 2000s
Maxus (rocket). Maxus is a sounding rocket that are used in the MAXUS microgravity rocket programme, a joint venture between Swedish Space Corporation and EADS Astrium Space Transportation used by ESA. It is launched from Esrange Space Center in Sweden and provides access to microgravity for up to 14 minutes.

Technical characteristics
Overall length: 15.5 m
Overall mass: 12 400 kg
Payload mass: approx. 800 kg
Max. velocity: 3500 m/s
Max. acceleration: 15 g
Propellant mass: 10 042 kg
Motor burn time: 63 s
Microgravity: up to 14 minutes
Apogee: > 700 km
Thrust(max. in vacuum): 500 kN

Missions

See also
Texus
Maser
Rexus/Bexus
Esrange

References

Sounding rockets of Sweden
Ray McIntire. Otis Ray McIntire (24August 19182February 1996) was an American inventor and engineer.  After graduating from the University of Kansas with a BSc degree in engineering in 1940, he went to work as a research engineer for The Dow Chemical Company. During World War II, when rubber was in short supply, McIntire's work focused on developing a rubber-like substance that could be used as a flexible insulator.  In an experiment, in which he combined styrene with isobutylene, he created a unique material that was solid yet flexible due to the tiny bubbles formed by isobutylene within the styrene.

McIntire had invented foam polystyrene, more commonly known by its brand name, Styrofoam, that was 30 times lighter and more flexible than solid polystyrene. It was also inexpensive and moisture resistant.

McIntire remained at The Dow Chemical Company for his entire career. He was promoted to research director, and later worked in the company’s consumer and venture capital divisions. He retired in 1981 as Dow’s director of technology and acquisition. 

McIntire died in 1996 from interstitial fibrosis. In March 2008, McIntire was inducted to the National Inventors Hall of Fame.

References

1918 births
1996 deaths
Dow Chemical Company employees
People from Johnson County, Kansas
20th-century American inventors
University of Kansas alumni
Kevin J. Sullivan (computer scientist). Kevin J. Sullivan is an American associate professor of computer science at the University of Virginia in Charlottesville, Virginia, United States. He also holds the title of Virginia Engineering Foundation (VEF)  Endowed Faculty Fellow in computer science at the University of Virginia. He is best known for his work with ultra-large-scale (ULS) systems.

He received a bachelor's degree from Tufts University in 1987, and received MS and PhD degrees in Computer Science and Engineering from the University of Washington in 1994. He has been at the University of Virginia since 1994.

His best known work is on Mediator-based Design Style with David Notkin, on the Galileo: Fault Tree Analysis Tool with Joanne Bechta Dugan. He has also contributed to the design of the Eos (programming language) along with Hridesh Rajan, and is one of many co-authors of the report Ultra-Large-Scale (ULS) Systems: The Software Challenge of the Future 

His most cited papers as shown in Scopus are: 
"Software reflexion models: Bridging the gap between source and high-level models ",by  Murphy, Gail C., Notkin, David, Sullivan, Kevin, Proceedings of the ACM SIGSOFT Symposium on the Foundations of Software Engineering 1995, pp. 18–27., cited 105 times
"Software reflexion models: Bridging the gap between design and implementation " by Murphy, G.C., Notkin, D., Sullivan, K.J. IEEE Transactions on Software Engineering.. 27 (4), 2001, pp. 364–380, cited 99 times.	
"Modular software design with crosscutting interfaces " by Griswold, W.G., Shonle, M., Sullivan, K., Song, Y., Tewari, N., Cai, Y., Rajan, H IEEE Software''  23 (1), pp. 51–60, 2006, cited 66 times.

References

External links 
 Kevin J. Sullivan's Home Page

Living people
Tufts University alumni
Tufts University School of Engineering alumni
University of Washington College of Engineering alumni
University of Virginia faculty
Year of birth missing (living people)
Isaac Wheeler Geer. Isaac Wheeler Geer (February 1, 1873 – June 20, 1953) was an executive with the Pennsylvania Railroad known for his involvement in labor disputes.

Education and early career 
Geer was born in Plainfield, Connecticut, to David and Eunice Witter Geer. After graduating from Phillips Academy, Andover, Isaac attended Yale, earning several awards in science and mathematics. He served as editor of the Yale Scientific Magazine. After graduating, Geer worked as an engineer on several major rail lines through the Midwest. By 1906, he had become superintendent of the Logansport division of the Pennsylvania Railroad and was based in St. Louis. In 1920, Isaac was promoted to general manager.

Labor dispute (1921) 
In 1921 Geer became embroiled in a dispute with labor unions. The unions claimed that Geer had authorized railroad executives to "defame" labor unions in order to force them to reveal information on the unions and on wage cuts. The unions produced a letter purportedly by Geer; but Geer denied having written it. During hearings of the United States Railway Labor Board, union lawyers failed to prove the authenticity of the letter.

Personal life 
On October 23, 1901, Geer married Margaret Worth Thornton, sister of Sir Henry Worth Thornton, cousin of Judge William Wheeler Thornton, and niece of Dr. William Patton Thornton.

The Geers had two children: Helen Thornton Geer, professor of library science and Margaret Worth Geer.

Isaac Wheeler Geer died at his home in Chicago on June 20, 1953.

Notes 

General and operations managers
1873 births
1953 deaths
20th-century American railroad executives
Pennsylvania Railroad people
Phillips Academy alumni
Yale University alumni
Timeline of British military aviation. The following timeline of British military aviation covers the military aviation activities of the British Armed Forces from its origins in the 19th century to the present day:

1863 - Henry Coxwell demonstrates tethered balloon ascents to British Army personnel at Aldershot
1878 - Balloon experiments are conducted at the Royal Arsenal, Woolwich
1880 - a balloon section takes part in the Army's manoeuvres at Aldershot
1882
a balloon section takes part again in the Aldershot manoeuvres
The Balloon Equipment Store at Woolwich is moved to the School of Military Engineering at Chatham
1882 to 1884 - A balloon factory, depot and training school are established at Chatham
1884 - Three balloons, two officers and 15 other ranks take part in the Bechuanaland Expedition
1885 Balloons are used during the Sudan expedition
1890 The Balloon Section is established as an official unit of the Royal Engineers
c. 1894 The balloon factory is moved to south Farnborough
1899 to 1902 Balloons are used in the South African War
Balloons used to direct the fire of the British Artillery at Magersfontein
Balloons used to direct the fire of the British Artillery at the Battle of Lombard's Kop
1905 The balloon factory is moved to a better site
1906 Samuel Franklin Cody is appointed the balloon school's Chief Instructor in Kiting
1907 The British Army airship, Nulli Secundus, is completed
1908 The first British heavier-than-air military flight takes place when the British Army Aeroplane No. 1 flies
1909 The War Office halts all work on aircraft at Farnborough on cost grounds
1911 The S. E. 1 and the B.E. 1 are built at Farnborough under the pretext of repairing existing aircraft
1 April The Balloon Section of the Royal Engineers becomes the Air Battalion
1912
13 May - The Royal Flying Corps is established from the Air Battalion
1914
1 July - The Royal Naval Air Service, having previously broken away from the Royal Flying Corps, is officially recognized
13 August - The first RFC aircraft arrive in France
27 August - The first RNAS aircraft arrive in Ostend
1918
1 April - The Royal Air Force is established by merging the Royal Flying Corps and the Royal Naval Air Service
1924
1 April - The Royal Air Force establishes its Fleet Air Arm, consisting of RAF units normally embarked on aircraft carriers and fighting ships
1937
14 May - The Fleet Air Arm is placed under Admiralty control
1940
November - The Battle of Taranto, the Fleet Air Arm launched the first all-aircraft naval attack in history
1941
21 December - The British Army regains an aviation element as the Glider Pilot Regiment is formed.
1942
24 February - The Glider Pilot Regiment is formally inaugurated as part of the Army Air Corps
1999
5 October - Joint Helicopter Command is formed
2000
1 April - Joint Force Harrier is formed
2024
May - Joint Aviation Command is formed from the Joint Helicopter Command with the addition of unmanned aerial systems from 32 Regiment, Royal Artillery

See also
Timeline of the Royal Air Force
History of air traffic control in the United Kingdom

Aviation timelines
Military aviation
British military aviation
Technology history of the United Kingdom
Nickel(II) chromate. Nickel(II) chromate (NiCrO4) is an acid-soluble compound, red-brown in color, with high tolerances for heat.  It and the ions that compose it have been linked to tumor formation and gene mutation, particularly to wildlife.

Synthesis

Nickel(II) chromate can be formed in the lab by heating a mixture of chromium(III) oxide and nickel oxide at between 700 °C and 800 °C under oxygen at 1000 atm pressure. It can be produced at 535 °C and 7.3 bar oxygen, but the reaction takes days to complete. If the pressure is too low or temperature too high but above 660 °C, then the nickel chromium spinel NiCr2O4 forms instead.

Karin Brandt also claimed to make nickel chromate using a hydrothermal technique.

Precipitates of Ni2+ ions with chromate produce a brown substance that contains water.

Properties

The structure of nickel chromate is the same as for chromium vanadate, CrVO4. Crystals have an orthorhombic structure with unit cell sizes a = 5.482 Å, b = 8.237 Å, c = 6.147 Å. The cell volume is 277.6 Å3 with four formula per unit cell.

Nickel chromate is dark in colour, unlike most other chromates which are yellow. The infrared spectrum of nickel chromate show two sets of absorption bands. The first includes lines at 925, 825, and 800 cm−1 due to Cr-O stretching, and the second has lines at 430, 395, 365 (very weak) due to Cr-O rock and bend and 310 cm−1 produced from Ni-O stretching.

Reaction

When heated at lower oxygen pressure around 600 °C, nickel chromate decomposes to the nickel chromite spinel, nickel oxide and oxygen.

4 NiCrO4 → 2 NiCr2O4 + 2 NiO + 3 O2 (gas)

Related
Nickel chromates can also crystallize with ligands. For instance, with 1,10-phenanthroline it can form triclinic olive-colored crystals of [Ni(1,10-phenanthroline)CrO4•3H2O]•H2O, orange crystals of Ni(1,10-phenanthroline)3Cr2O7•3H2O, and yellow powdered Ni(1,10-phenanthroline)3Cr2O7•8H2O.

References

Nickel compounds
Chromates
Oxidizing agents
Multistage testing. Multistage testing is an algorithm-based approach to administering tests. It is very similar to computer-adaptive testing in that items are interactively selected for each examinee by the algorithm, but rather than selecting individual items, groups of items are selected, building the test in stages. These groups are called testlets or panels.

While multistage tests could theoretically be administered by a human, the extensive computations required (often using item response theory) mean that multistage tests are administered by computer.

The number of stages or testlets can vary. If the testlets are relatively small, such as five items, ten or more could easily be used in a test. Some multistage tests are designed with the minimum of two stages (one stage would be a conventional fixed-form test).

In response to the increasing use of multistage testing, the scholarly journal Applied Measurement in Education published a special edition on the topic in 2006.

References

Further reading 
 

Psychological testing
Carbohydrazide. Carbohydrazide is the chemical compound with the formula OC(N2H3)2.  It appears as a white solid that is soluble in water, but not in many organic solvents, such as ethanol, ether or benzene. It decomposes upon melting.  A number of carbazides are known where one or more N-H groups are replaced by other substituents.  They occur widely in the drugs, herbicides, plant growth regulators, and dyestuffs.

Production
Industrially the compound is produced by treatment of urea with hydrazine:
OC(NH2)2  +  2 N2H4   →   OC(N2H3)2 +  2 NH3  
It can also be prepared by reactions of other C1-precursors with hydrazine, such as carbonate esters. 
It can be prepared from phosgene, but this route cogenerates the hydrazinium salt [N2H5]Cl and results in some diformylation.  Carbazic acid is also a suitable precursor:
N2NH3CO2H  +  N2H4   →   OC(N2H3)2 + H2O

Structure
The molecule is nonplanar. All nitrogen centers are at least somewhat pyramidal, indicative of weaker C-N pi-bonding.  The C-N and C-O distances are about 1.36 and 1.25 Å, respectively.

Industrial uses
 Oxygen scrubber: carbohydrazide is used to remove oxygen in boiler systems. Oxygen scrubbers prevent corrosion.
 Precursor to polymers:  carbohydrazide can be used as a curing agent for epoxide-type resins.
 Photography: carbohydrazide is used in the silver halide diffusion process as one of the toners. Carbohydrazide is used to stabilize color developers that produce images of the azo-methine and azine classes.
 Jet fuel: carbohydrazine can be used as a component in jet fuels, as a large amount of heat is being produced when the material is burned.
 Carbohydrazide has been used to develop ammunition propellants, stabilize soaps, and is used as a reagent in organic synthesis.
 Salts of carbohydrazide, such as nitrate, dinitrate and perchlorate, can be used as secondary explosives. Complex salts of carbohydrazide, like bis(carbohydrazide)diperchloratocopper(II) and tris(carbohydrazide)nickel(II) perchlorate, can be used as primary explosives in laser detonators.

Hazards
Heating carbohydrazide may result in an explosion. Carbohydrazide is harmful if swallowed, irritating to eyes, respiratory system, and skin. Carbohydrazide is toxic to aquatic organisms.

References 

Cleaning product components
Hydrazides