omniomni/omni-engineering huggingface dataset:
Virginius E. Clark. Virginius Evans Clark (February 27, 1886 – January 30, 1948) was an officer in the United States Army, a military aviation pioneer, and a World War I engineer. Clark designed the 1922 Clark Y airfoil used by many early aircraft.

Biography

He was born on February 27, 1886, to Harry Scott Clark in Uniontown, Pennsylvania. Clark graduated the United States Naval Academy in 1907. He participated in the 1908-1909 round-the-world battleship voyage with the Great White Fleet. Later he was part of the Coast Artillery until 1912. In 1913 Clark joined the Aeronautical Division, U.S. Signal Corps. In 1914, Clark attended Massachusetts Institute of Technology for an aviation engineering course.

In 1917, Clark became a NACA member, and a member on the Joint Army and Navy Board on Rigid Airships. In 1917 Clark became the Commanding officer of McCook Field founding the current Aeronautical Systems Center. While at McCook, Clark and Verville designed the VCP-1, and Engineering Division TP-1 aircraft. Clark was sent to Europe in June 1917 representing the Army on the"Bolling Mission", an aeronautical commission on aviation for the acquisition of airplanes to fight World War I. In 1922 Clark was also the Vice President of the Society of Automotive Engineers. In 1920 he became the chief engineer of the Dayton-Wright Company. In 1923, he became the vice president of Consolidated.  Clark later worked for the Duramold division of Fairchild Aircraft in 1938. Clark designed the Fairchild 100, Fairchild 150, and the 46 Duramold (later the Fairchild 46-A). He became a consultant at Hughes Aircraft Company. Clark's Duramold process would later be used on the Spruce Goose.

He died in Santa Monica on January 30, 1948.

References

1886 births
1948 deaths
United States Navy engineering officers
American aerospace engineers
Aerodynamicists
American aviators
World Air Power Journal. World Air Power Journal was a quarterly aviation magazine concentrating on modern military aviation in the period 1989 to 2000. The contents included news, military air operations, new aircraft briefings, air forces analysis and photo features and in-depth articles about particular aircraft types - usually presented in great detail, and with lavish illustration, including a gatefold centrefold with airbrushed artwork and cutaway drawings. The editors' philosophy was to include an article on a "focus aircraft" that would effectively serve as a monographic book on that subject - often running over more than 50 of the magazine’s 160 pages.

The title was published by Aerospace Publishing/Midsummer Books, a small publishing and packaging house based in West London, owned and managed by Stan Morse. The company was previously best known for publishing military, aviation and wildlife partwork magazines including The Illustrated Encyclopedia of Aircraft, War Machine, Warplane, Take Off, Airplane and World Aircraft Information Files.

World Airpower Journal lasted 43 issues before its publisher folded the title in December 2000, with the final issue being published in December 2000. A number of books were also published bearing the World Air Power Journal imprint. The US distributors of World Air Power Journal, AIRtime publishing, subsequently launched a replacement title for this publication and its companion historic aviation publication Wings of Fame called International Air Power Review.

David Donald was the managing editor, aviation for the whole period of World Air Power Journal, working under him (at different times, and on the two quarterlies) were Bob Munro, Jon Lake, Robert Hewson, Jim Winchester, Daniel March, John Heathcote and Tim Senior. Robert F. Dorr served as the magazine's Washington correspondent, while regular contributors included Bob Archer, Brad Elward, Peter Foster, Rene Francillon, Bill Gunston, Tony Holmes, Paul A Jackson, Randy Jolly, Francis K Mason, Peter Mersky, Lindsay T Peacock, Alfred Price and Tim Ripley. After World Air Power Journal folded Donald, March and Heathcote moved over to edit the new title for AIRtime.

References

External links
 List of World Airpower Journal issues with article index

Aviation magazines
Transport magazines published in the United Kingdom
Quarterly magazines published in the United Kingdom
Defunct magazines published in the United Kingdom
Magazines established in 1989
Magazines disestablished in 2000
Pitts Sky Car. The Pitts Sky Car was an unsuccessful aircraft designed for vertical take off, by inventor John W. Pitts of Detroit, Michigan.

Pitts filed a United States patent in 1924 for a propeller, "which will cause an immediate vertical lift of any aerial car to which the propeller is attached". This consisted of a "mushroom-shaped" rotor of 60 blades, each hinged at the root. An engine would rotate and reciprocate the propeller, causing the blades to close on the downstroke and open on the upstroke, which it was hoped would induce lift. The patent was granted in October 1926.

In collaboration with W. P. Kindree, Pitts constructed a  prototype with a  Curtiss OX-5 engine. A newsreel of 1928 shows the Sky Car attempting to fly; however rather than take off, it merely jumps up and down.

In popular culture 
Today, footage of the ill-fated Sky Car is often compiled with footage of the Gerhardt Cycleplane, various ornithopters, cyclogyros and other contraptions, and often cited as examples of early failed flight attempts, though in reality these took place 25 years after the first successful flights by the Wright Brothers. Famous movies in which the Sky Car can be briefly seen include Those Magnificent Men in Their Flying Machines and Airplane!.

References

External links
 Film of the Sky Car in action

1920s United States experimental aircraft
Unflown aircraft
Single-engined piston aircraft
Spectral acceleration. Spectral acceleration (SA) is a unit measured in g (the acceleration due to Earth's gravity, equivalent to g-force) that describes the maximum acceleration in an earthquake on an object – specifically a damped, harmonic oscillator moving in one physical dimension. This can be measured at (or specified for) different oscillation frequencies and with different degrees of damping, although 5% damping is commonly applied. The SA at different frequencies may be plotted to form a response spectrum.

Spectral acceleration, with a value related to the natural frequency of vibration of the building, is used in earthquake engineering and gives a closer approximation to the motion of a building or other structure in an earthquake than the peak ground acceleration value, although there is normally a correlation between [short period] SA and PGA.

Some seismic hazard maps are also produced using spectral acceleration.

See also
Seismic scale

External links
Spectral Acceleration Hazard Map of California – for 1 sec period 
2005 National Building Code of Canada – Spectral Acceleration Hazard Maps for various periods
Revision of Time-Independent Probabilistic Seismic Hazard Maps for Alaska
What is a ground shaking hazard map? – Includes explanations of SA and PGA

References

Seismology
Earthquake engineering
Makespan. In operations research, the makespan of a project is the length of time that elapses from the start of work to the end. This type of multi-mode resource constrained project scheduling problem (MRCPSP) seeks to create the shortest logical project schedule, by efficiently using project resources, adding the lowest number of additional resources as possible to achieve the minimum makespan. The term commonly appears in the context of scheduling.

Example 
There is a complex project that is composed of several sub-tasks. We would like to assign tasks to workers, such that the project finishes in the shortest possible time. As an example, suppose the "project" is to feed the goats. There are three goats to feed, one child can only feed one goat at a time, and there are two children that can feed them: Shmuel feeds each goat in 10 minutes and Shifra feeds each goat in 12 minutes. Several schedules are possible:
 If we let Shmuel feed all goats, then the makespan is 30 (3×10 for Shmuel, 0 for Shifra);
 If we let Shifra feed one goat and Shmuel two goats, then the makespan is 20 (2×10 for Shmuel, 12 for Shifra working beside and in parallel to Shmuel);
 If we let Shifra feed two goats and Shmuel one goat, then the makespan is 24 (2×12 for Shifra, 10 for Samuel working beside and in parallel to Shifra);
 If we let Shifra feed all goats, then the makespan is 36 (3×12 for Shifra, 0 for Shmuel).
So in this case, the second schedule attains the shortest makespan, which is 20.

Types of makespan minimization problems 
 Johnson's Rule – there are n jobs and 2 different stations. Consider using this rule to sequence jobs that must go through both work centers.
 Job shop scheduling – there are n jobs and m identical stations. Each job should be executed on a single station. This is usually regarded as an online problem.
 Open-shop scheduling – there are n jobs and m different stations. Each job should spend some time at each station, in a free order.
 Flow shop scheduling – there are n jobs and m different stations. Each job should spend some time at each station, in a pre-determined order.
Fair makespan minimization - When assigning tasks to agents, it is required both to minimize the makespan, and to avoid envy. If the fastest worker is given a job, he has to be compensated for his extra effort. Mu'alem presents a general framework for optimization problems with envy-freeness guarantee using monetary payments.

References

Scheduling (computing)
Duramold. Duramold is a composite material process developed by Virginius E. Clark. Birch or poplar plies are impregnated with phenolic resin  and laminated together in a mold under heat (280 °F, 138 °C) and pressure for use as a lightweight structural material. Similar to plywood, Duramold and other lightweight composite materials like the similar Haskelite were considered critical during periods of material shortage in World War II, replacing scarce materials such as aluminum alloys and steel.

The material has some advantages over metal in strength, construction technique, and weight. A cylinder made of Duramold is 80% stronger than a cylinder made of aluminum. Over 17 varieties of Duramold were developed, using various combinations of types of wood in thin plies. The Duramold process has also been used to make radomes for aircraft, as well as missile bodies.

Virginius Clark developed Duramold for Fairchild Aircraft, working with George Meyercord of the Haskelite Corporation. Fairchild patented the process, designing and constructing the F-46 as the first aircraft made using the Duramold process, and forming the Duramold Corporation. Several aircraft used Duramold in parts of their structure, the largest manufactured with the process being the Hughes H-4 Hercules designed by Howard Hughes and Glenn Odekirk, which was built almost completely with Duramold including very large sections. For this use, Hughes Aircraft bought the rights to the use of Duramold on aircraft exceeding 20,000 lb; Fairchild and Meyercord otherwise retained the rights, but the material was found to be poorly adapted to heavy aircraft.

The Duramold and Haskelite process was first developed in 1937, followed by Gene Vidal's Weldwood and later the Timm Aircraft Company's Aeromold process, which differs in that it is baked at a low 100 °F (38°C) at cutting and forming, and 180 °F (82°C) for fusing together sections after the resins are added. In the United Kingdom, the De Havilland Aircraft Company (founded by Geoffrey de Havilland, a cousin of Olivia de Havilland, the actress who dated Howard Hughes in 1938) used similar composite construction for aircraft, including the DH.88 Comet, DH.91 Albatross, the Mosquito, and Vampire.

See also 
 Tego film
 Aerolite (adhesive)
 Stitch and glue

References

Aircraft components
Aerospace materials
Plywood
List of tunnels in Brazil. This is a list of tunnels in Brazil.

Pernambuco 
  Plínio Pacheco (Cascavel) 370 m 2007

Rio de Janeiro 
 Rua Alice 220 m 1887
 Alaor Prata 182 m 1892
 Engenheiro Coelho Cintra 250 m 1906
 João Ricardo  0293 m 1921
 Engenheiro Marques Porto 0250 m 1949
 Sá Freire Alvim  0326 m 1960
 Major Rubens Vaz  0220 m 1963
 Santa Bárbara  1357 m 1963
 Rebouças  2800 m
 Acústico  0550 m 1971
 Zuzu Angel 1590 m 1971
 São Conrado 0260 m 1971
 Joá   426 m 1971
 Martim de Sá 0304 m 1977
 Noel Rosa 0720 m
 Eng. Raimundo de Paula Soares 2187 m 1997
 Eng. Enaldo Cravo Peixoto 0153 m 1997
 Geólogo Enzo Totis  0165 m 1997
 Mergulhão Praça XV 0100 m 1997
 Grota Funda TransOeste  2012

Brazil
 
Tunnels
Tunnels
4,4'-Methylenedianiline. 4,4′-Methylenedianiline (MDA) is an organic compound with the formula .  It is a colorless solid, although commercial samples can appear yellow or brown. It is produced on an industrial scale, mainly as a precursor to polyurethanes.

Synthesis and applications 
In the industrial production, MDA is produced by reaction of formaldehyde and aniline in the presence of hydrochloric acid.

MDA is a common monomer in the synthesis of polymer materials. These include polyamides, polyimides and polyimines. MDA is also used extensively as a precursor to methylene diphenyl diisocyanate (MDI). Here, MDA is treated with phosgene to produce MDI.  MDI, in turn, is a precursor to many polyurethane foams. Lower quantities are used as hardeners in epoxy resins and adhesives, as well as in the production of high-performance polymers.  Additionally, hydrogenation of MDA can be performed to produce 4,4,diaminodicyclohexylmethane, which is also used in polymer chemistry.

MDA can also be applied as a bidentate (bridging) ligand in the formation of metal-coordination complexes.

Safety
MDA is considered a potential occupational carcinogen by the US National Institute for Occupational Safety and Health. The Occupational Safety and Health Administration has set a permissible exposure limit at 0.01 ppm over an eight-hour time-weighted average, and a short-term exposure limit at 0.1 ppm.

It is suspected carcinogen. It is included in the "substances of very high concern" list of the European Chemicals Agency (ECHA).  The compound was blamed in a mass poisoning in the vicinity of Epping, Essex, United Kingdom during 1965 during which 84 individuals were poisoned through accidental contamination of flour used to make bread.

Related compounds
 4,4'-Thiodianiline
 4,4'-Oxydianiline
 Dapsone

References

External links 
 
 
 
 

4-Aminophenyl compounds
IARC Group 2B carcinogens
Mass poisoning
Lero (software engineering). Lero, the Science Foundation Ireland Research Centre for Software, Ireland, is a world-leading Science Foundation Ireland (SFI) research centre. It was established in 2005 as an SFI Centre for Science Engineering and Technology (CSET), being one of nine (originally ten) such centres established by the Irish Government in various areas of science and engineering.

Overview 
Hosted at University of Limerick, Lero, the Science Foundation Ireland Research Centre for Software, is home to around 250 active researchers across eight Irish universities and three Institutes of Technology. Its research spans a wide range of application domains from driverless cars to artificial intelligence, cybersecurity, fintech, govtech, smart communities, agtech and healthtech.

Lero brings together researchers from University of Limerick, Dublin City University, Trinity College Dublin, University College Dublin, Maynooth University, National University of Ireland Galway, University College Cork, Munster Technological University, Dundalk Institute of Technology, Waterford Institute of Technology and Limerick Institute of Technology. 

As the world’s second largest software exporter, Ireland is recognised internationally as a leading location for companies in the software sector and Lero is a key pillar of that. Fifteen out of the top 20 global technology firms have strategic operations in Ireland. Lero actively engages with industry and currently has in the region of 50 industry partners.

Leadership 
Lero's first Centre Director was Professor Kevin T Ryan and its Scientific Director was Professor Klaus Pohl. Professor Mike Hinchey was appointed Director of Lero in mid-2010. Professor Bashar Nuseibeh served as Lero's first Chief Scientist from 2009 to 2013 and was succeeded by Professor Brian Fitzgerald. In 2016, Professor Fitzgerald was appointed Director of Lero and was succeeded by Professor Lionel Briand in 2024. Professor Nuseibeh returned to the role of Chief Scientist from 2017 to 2023.

Joe Gibbs was appointed General Manager in 2018 replacing Brendan O’Malley. Mr Gibbs previously held the role of Business Development Manager at the centre.

References

Educational institutions established in 2005
University of Limerick
Research institutes in the Republic of Ireland
Software engineering organizations
2005 establishments in Ireland
Revitalizant. Revitalizant ( — life, can be literally translated to “bringing back to life”) is a semi-permanent treatment for metals found in automobile engines, transmissions, fuel pumps, and other friction surfaces in industrial and other machines.  The treatment is added to the engine oil, operating fluids, or fuel.  The treatment forms a protective cermet or ceramic-metal coating on the friction metal parts of the mechanisms directly during the process of their operation. The  Revitalizant  solves the problem of non-wear operation of cars and mechanisms.

History

The Revitalizant was developed in 1998 in Kharkiv (Ukraine) by XADO. The composition and the method of its preparation are patented. The notion was included in the textbook on tribology.

Description 
Visually it is a gel or a plastic substance. It consists of a lubricant and a mixture of oxides and metal oxide hydrates: Al2O3 and/or SiO2 and/or MgO and/or CaO and/or Fe2O3 etc., with dispersion from 100 to 10,000 nanometers.

Properties 
Under certain conditions (pressure and temperature) typical for the contact of the parts during  friction, the substances contained in the revitalizant act as a catalyst for creating the metal carbide of coupling materials.

      
      where Me stands for metal; C - carbon.

Particles of the substance have the form similar to the spherical and  during the process of friction they are acting as surface hardening and  at the same time as rolling substances, reducing the friction coefficient.

Process 
The process of the protective coating formation, called revitalization, is based on physical-chemical interaction between surfaces of the parts on the spots of virtual contact covered with revitalizant in a boundary or mixed lubrication mode. As a result a gradient cermet coating is formed, containing positive compressive stresses all over its depth and concentration of carbon, increasing at the surface  (up to the formation of diamond-like structures). Distinctive feature of the process is a hardening of the coating with its simultaneous growth

Application 
Used in the manufacture of lubricants, greases and additives.

References 

Lubricants
Oil additives
Scheibe SF 36. The Scheibe SF 36 is a German two-seat self-launched powered sailplane designed and built by Scheibe Aircraft.

Design
The SF 36 is an all composite sailplane with an engine mounted at the front. It is a low-wing monoplane with airbrakes fitted to the upper surface, it can be fitted with either a fixed or retractable landing gear. The SF 36 has a cruciform tail with a fixed horizontal stabilizer and an enclosed cabin which has two seats side by side.

The SF 36 is available in two variants, the SF 36A powered by either a Limbach or Sauer piston engine, and the Rotax-powered SF 36R.

Variants 
SF 36 A
Powered by either a Limbach L2000 EA, Sauer S 2100-1-HS1 or Sauer S 2100-1-SS1 engine.
SF 36 R
Rotax 912-powered variant.

Specifications (SF 36A)

References

1980s German civil utility aircraft
Motor gliders
Scheibe
Low-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1980
Single-engined piston aircraft
Aircraft with fixed conventional landing gear
Re-mix. re-mix is an open-source library (LGPL) to bring the mixin technology to C# and Visual Basic.NET.

History 
.NET does not offer multiple inheritance. Nevertheless, in some use cases multiple inheritance support would be helpful for .NET applications. In languages such as Ruby these use cases were solved with mixins.

The company rubicon created a mixin library for the Microsoft .NET Framework  to add multiple inheritance to their own applications.

The mixin library became part of the open source framework re-motion. In March 2011, re-mix has been published on CodePlex as spin-off project of re-motion. It was later re-incorporated into re-motion after CodePlex was discontinued in 2017.

References 

Free software programmed in C Sharp
Green bridge (filtration system). Green bridges are an ecotechnological in-situ bio remediation system. Their different physical and biological filters work in combination to remove suspended and dissolved impurities of water. Green bridge filters help in reducing the suspended solids by filtration process, reducing Chemical Oxygen Demand (COD)/Biochemical Oxygen Demand (BOD) by aerobic degradation. Green Bridges also help in the restoration of ecological food chain.

Development 
Natural streams, rivers and lakes have their own in-built purification system which consists of natural slopes, stones for biological growth and complex food web help in the purification process. This food web is nothing but utilization of one's waste by another as its own food. Nature has her own living machinery of detritivorous microbes and other living species to consume wastes. These principles have been harnessed in the treatment of polluted streams.

Green bridges are developed using fibrous material with stones. All the floatable and suspended solids are trapped in this biological bridge and the turbidity of flowing water is reduced. Green plants on the bridges increase the DO level in water, which in turn facilitates the growth of aerobic organisms, which degrade organic pollutants. Sandeep Joshi, director, SERI (Shrishti Eco-Research Institute) has developed this technology and has received a patent for it.

Benefits 
 Capital expenditure is comparable with the annual operational cost of conventional bioremediation systems.
 Can be developed and operated in combination with conventional systems to improve the performance of the latter.
 Reduce the ecotoxicity of the man-made substances released into the water bodies and facilitate the eco-assimilation of those pollutants into the ecological cycles thus reducing the quantum of hazardous residues to zero which otherwise require costly secured landfill and incineration techniques.

Expected results
 Solids control : 40–80% reduction
 Pollution control : COD/BOD reduction – 40–90%
 Fecal coliforms control : 50–100% reduction
 Ecotoxicity : Nil
 Dissolved oxygen : Increased by 150% – 1200%
 Aquatic species :
 Increase in plants/plankton – 200%
 Increase in micro-invertebrates – 200%

Other than the changes in the water quality mentioned above a multifold change in population of avifauna, terrestrial plants along the riverbanks has been noticed. There is an overall odour and mosquito reduction and improvement of river aesthetics. Increase in health status of aquatic life in lentic-lotic system by reduction in ecotoxicity of pollutants.

References

External links 
 
 
 http://moef.nic.in/downloads/public-information/press-note-launch-of-bio-remediation-project-ludhiana.pdf
 
 Badal gives go ahead to NEER project for Budha Nullha  LivePunjab
 - Express India
 
 Green bridge tech helps restore nullah - Times Of India
 
 India Together: Cost-effective technology stalled by Pune government - 31 May 2010
 

Aquatic ecology
Environmental engineering
Pollution control technologies
Sewerage
Water treatment
Sanitation
Sewerage infrastructure