omniomni/omni-engineering huggingface dataset:
N,N'-Methylenebisacrylamide. {{DISPLAYTITLE:N,N'-Methylenebisacrylamide}}

N,N′-Methylenebisacrylamide (MBAm or MBAA, colloquially "bis") is the organic compound with the formula CH2[NHC(O)CH=CH2]2. A colorless solid, this compound is a crosslinking agent in polyacrylamides, e.g., as used for SDS-PAGE.

Synthesis 
Acrylamide reacts with an aqueous solution of formaldehyde in the presence of copper(I) chloride as a polymerization inhibitor and sulfuric acid as catalyst to form N,N′-methylenebisacrylamide with yields of 60 to 80%.

The reaction proceeds via N-hydroxymethylacrylamide, which can be detected in alkaline solution and decomposes in acid to give N,N′-methylenebisacrylamide. Using acrylamide and paraformaldehyde in 1,2-dichloroethane gives a clear solution upon heating, from which MBA crystallizes.

In aqueous media, acrylonitrile also reacts with formaldehyde to give crude N,N′-methylenebisacrylamide, which can be purified by recrystallization with acetone/water.

Reactions and uses 
Under basic conditions, MBA reacts further with formaldehyde at the amide nitrogen to give N-hydroxymethyl,N,N′-methylenebisacrylamide. Nucleophiles such as alcohols, amines, or thiols add across the activated vinyl groups, giving mixtures of mono- and disubstituted products.

As a bifunctional electron-poor dienophile, MBA reacts with electron-rich dienes, such as cyclopentadiene, in Diels–Alder reactions, giving the corresponding norbornene adducts.

As a symmetric, unconjugated divinyl monomer, MBA can be used with suitable initiators in cyclopolymerizations to create linear, soluble polymers whose backbones are built from five- and seven-membered rings. With acrylic and vinylic monomers such as acrylonitrile, acrylamide, and substituted acrylamides, MBA can undergo radical copolymerization to form highly crosslinked gels, using peroxides, UV light, or redox initiators.

The properties of such gels are determined by the crosslink density, and targeted gel formation using MBA crosslinking gives useful technical properties used in various applications, such as in adhesives, paints, and superabsorbents. In biochemistry, MBA is used for chromatography gels and polyacrylamide gel electrophoresis.

See also
 DATD

References

Acrylamides
Monomers
Space vector modulation. Space vector modulation (SVM) is an algorithm for the control of pulse-width modulation (PWM), invented by Gerhard Pfaff, Alois Weschta, and Albert Wick in 1982. It is used for the creation of alternating current (AC) waveforms; most commonly to drive 3 phase AC powered motors at varying speeds from DC using multiple class-D amplifiers. There are variations of SVM that result in different quality and computational requirements. One active area of development is in the reduction of total harmonic distortion (THD) created by the rapid switching inherent to these algorithms.

Principle

A three-phase inverter as shown to the right converts a DC supply, via a series of switches, to three output legs which could be connected to a three-phase motor.

The switches must be controlled so that at no time are both switches in the same leg turned on or else the DC supply would be shorted. This requirement may be met by the complementary operation of the switches within a leg. i.e. if A+ is on then A− is off and vice versa. This leads to eight possible switching vectors for the inverter, V0 through V7 with six active switching vectors and two zero vectors.

Note that looking down the columns for the active switching vectors V1-6, the output voltages vary as a pulsed sinusoid, with each leg offset by 120 degrees of phase angle.

To implement space vector modulation, a reference signal Vref is sampled with a frequency fs (Ts = 1/fs). The reference signal may be generated from three separate phase references using the  transform. The reference vector is then synthesized using a combination of the two adjacent active switching vectors and one or both of the zero vectors. Various strategies of selecting the order of the vectors and which zero vector(s) to use exist. Strategy selection will affect the harmonic content and the .

More complicated SVM strategies for the unbalanced operation of four-leg three-phase inverters do exist. In these strategies the switching vectors define a 3D shape (a hexagonal prism in  coordinates or a dodecahedron in abc coordinates) rather than a 2D hexagon. General SVM techniques are also available for converters with any number of legs and levels.

See also
 αβγ transform
 Inverter (electrical)
 pulse-width modulation

References

Electrical engineering
Control theory
Lohner E. The Lohner E was a reconnaissance flying boat built in Austria-Hungary during World War I. The "E" stood for Igo Etrich, one of the Lohner engineers. It was a conventional design for its day with biplane wings that featured slight sweepback, and an engine mounted pusher-fashion in the interplane gap. Its crew of two was seated in an open cockpit.

Around 40 examples were built before production shifted to the more powerful L.

Operators

Specifications

See also

Notes

Bibliography

 Angelucci, Enzo. The Rand McNally Encyclopedia of Military Aircraft, 1914-1980. San Diego, California: The Military Press, 1983. .
 Taylor, Michael J. H. Jane's Encyclopedia of Aviation. London: Studio Editions, 1989. .
 Tucker, Spencer. The Encyclopedia of World War I. Santa Barbara: ABC-Clio, 2005. . 

1910s Austro-Hungarian military reconnaissance aircraft
E
Flying boats
Biplanes
Single-engined pusher aircraft
Aircraft first flown in 1913

sr:Лонер TL
Chinese ship Shichang. Shichang is a training ship in the People's Republic of China's People's Liberation Army Navy (PLAN). The ship is formally designated as a "defence mobilization vessel" and may be used for helicopter or navigation training, as a container ship, or as a hospital ship. It is the PLAN's first aviation training ship. The NATO reporting name for the type is Daishi-class AXT.

Design
The original plan was to convert Shichang from the civilian roll-on/roll-off ship Huayuankou; a new ship was built instead.

Shichang has a bridge structure forward with the flight deck occupying most of the remaining area behind it; the funnel is toward the stern on the starboard side. The flight deck has two landing spots and may be reconfigured; options include a modular hangar and control space behind the forward structure, or 300 standard 20-foot containers.

See also
RFA Argus (A135), a Royal Navy auxiliary with a similar configuration

References

Sources

Auxiliary ships of the People's Liberation Army Navy
Training ships of the People's Liberation Army Navy
1997 ships
Auxiliary training ship classes
Robot Wrecks. Robot Wrecks is a 1941 Our Gang short comedy film directed by Edward Cahn. It was the 200th Our Gang short to be released.

Plot
Slicker sells the Our Gang kids some "invisible rays," with which they hope to power their homemade mechanical robot. Miracle of miracles, the robot not only begins to move, but actually performs several of the gang's household chores. In truth, the robot is being manipulated by Slicker's cohort Boxcar, but the kids do not learn this until their rampaging mechanical man nearly lays waste to the entire neighborhood.

Cast

The Gang
 Mickey Gubitosi as Mickey
 Darla Hood as Darla
 George McFarland as Spanky
 Billy Laughlin as Froggy
 Billie Thomas as Buckwheat

Additional cast
 Vincent Graeff as Boxcar
 Freddie Walburn as Slicker
 Margaret Bert as Froggy's Mother
 Billy Bletcher as Froggy's father / Voice of Froggy's Mother
 Emmet Vogan as Robot owner
 Giovanna Gubitosi as Onlooker at robot demonstration

See also
 Our Gang filmography

References

External links

1941 films
1941 comedy films
American black-and-white films
Films directed by Edward L. Cahn
Metro-Goldwyn-Mayer short films
Our Gang films
1941 short films
American robot films
1940s American films
1940s English-language films
English-language comedy short films
System area code. In air traffic control, the system area code (SAC) is part of a unique identifier assigned to each system which uses the ASTERIX format. The Eurocontrol SuRveillance Data Exchange Task Force (RDE-TF) maintains these identifiers internationally and assigns them to regions such as countries, though sometimes more than one code is assigned within the same country, for example to distinguish between civilian and military uses. 

Within each country, it is the responsibility of the relevant air navigation service provider to allocate a system identification code (SIC); up to 256 of them for each SAC.

In the Asterix protocol the SAC/SIC identifies the actual sensor from where the radar information is sent. 
The information being e.g. plot and track.

References

External links 
 SAC List (worldwide)
Air traffic control
AR 5. AR5, AR 5, or AR-5 can refer to:

ArmaLite AR-5, a .22 caliber bolt-action aircrew survival rifle
Arkansas Highway 5, a designation for three state highways in Arkansas
Arkansas's 5th congressional district, an obsolete district
IPCC Fifth Assessment Report, a 2014 synthesis report produced by the Intergovernmental Panel on Climate Change
, a US Navy repair ship
FEKO. Feko is a computational electromagnetics software product developed by Altair Engineering.  The name is derived from the German acronym "Feldberechnung für Körper mit beliebiger Oberfläche", which can be translated as "field calculations involving bodies of arbitrary shape". It is a general purpose 3D electromagnetic (EM) simulator.

Feko originated in 1991 from research activities of Dr. Ulrich Jakobus at the University of Stuttgart, Germany. Cooperation between Dr. Jakobus and EM Software & Systems (EMSS) resulted in the commercialisation of FEKO in 1997. In June 2014, Altair Engineering acquired 100% of EMSS-S.A. and its international distributor offices in the United States, Germany and China, leading to the addition of FEKO to the Altair Hyperworks suite of engineering simulation software.

The software is based on the Method of Moments (MoM) integral formulation of Maxwell's equations 

 and pioneered the commercial implementation of various hybrid methods such as:

 Finite Element Method (FEM) / MoM where a FEM region is bounded with an integral equation based boundary condition to ensure full coupling between the FEM and MoM solution areas of the problem.
 MoM / Physical Optics (PO) where computationally expensive MoM current elements are used to excite computationally inexpensive PO elements, inducing currents on the PO elements.  Special features in the FEKO implementation of the MoM/PO hybrid include the analysis of dielectric or magnetically coated metallic surfaces.

 MoM / Geometrical Optics (GO) where rays are launched from radiating MoM elements.

 MoM / Uniform Theory of Diffraction (UTD) where computationally expensive MoM current elements are used to excite canonical UTD shapes (plates, cylinders) with ray-based principles of which the computational cost is independent of wavelength.

A Finite Difference Time Domain (FDTD) solver was added in May 2014 with the release of FEKO Suite 7.0.

References

External links

Numerical software
Software that uses Qt
Electromagnetic simulation software
EUPHIX. The objective of the European Union Public Health Information and Knowledge system (EUPHIX project) is to develop a sustainable system to integrate and present public health information and knowledge for policy makers, academics and public health specialists at a European, national and regional level. Its objectives are to deliver a technical web system, publishing protocols and an expert network, all facilitating the production and regular updates of data presentations and text for the [www.EUPHIX.org] website. It is publicly accessible and has ‘deep links’ to the Public Health-EU portal. It serves as an information & knowledge exchange platform, but also as an example of how public health information can be presented in a dynamic and interactive fashion.

Completed topics are addressed with comprehensive texts & data which have been written and reviewed by public health experts. Technically the system is equipped to present text with interactive links to sources, maps, graphs, tables, detail pages, definitions and other relevant web-pages. The editing process is described in publishing protocols. A growing number of experts are active as authors and reviewers. Reports on broader topics have been developed in collaboration with other EU funded health projects.

The project proved that within a limited amount of time, a totally new communication system for public health knowledge can be established. At this point the number of users is growing. The system shows the feasibility of a system that can be continuously updated and expanded to fulfill urgent policy needs.

External links
 
 
 Health-EU Portal) the official public health portal of the European Union

Health in Europe
Wings India. Wings India (formerly the Indian Civil Aviation Airshow) is a biennial air show held in Hyderabad, Telangana, India at the Begumpet Airport. The first show, India Aviation 2008, was held from 15 to 18 October 2008. It is organised by the Union civil aviation ministry. Begumpet is preparing to receive the world's largest passenger aircraft after the place was closed for regular commercial operations and is now used only for private, defence and VVIP aircraft ever since the new Rajiv Gandhi International Airport at Shamshabad, Hyderabad became operational. Hyderabad will be a permanent venue for this Airshow.

The show includes both air displays and static exhibitions of various Civil and Military aircraft, along with displays from vendors, suppliers and production organisations. The aircraft, which were on static or flying display, include Boeing 777, Airbus A340, Canadian Regional Jet of Bombardier Citation, business jets manufactured by various global leaders, Bell Helicopters, DragonFly, Cessna, Indian-made Pushpak and Indian firm Hindavia's Russian-made regional aircraft Ilyushin Il-114. This is apart from the world's largest passenger aircraft, the Airbus A380, which made its maiden and historic landing at Hyderabad's Begumpet Airport on 16 October 2008.

The show was unveiled by Union Minister for Civil Aviation Mr. Praful Patel. Top honchos of the aviation industry from India and abroad were a part of the event, including Air India CMD Raghu Menon, Kingfisher Airlines chief Vijay Mallya, former US FAA Administrator Marion C Blakey, AAI chief K Ramalingam, EADS CEO Yves Guillame, GoAir MD Jehangir Wadia, Air Arabia CEO Adel Ali and top-brass of various airport operators, engine, avionics and aircraft manufacturers like Boeing, Airbus, Bombardier and Bell Helicopters.

While the show is meant only for business visitors who are invited, other business visitors (above 18 years) can also visit the show by purchasing an entry ticket. The last day of the 2008 show was open to public. The show was a sort of partnership between FICCI and AAI to jointly organise it for the overall sustainable development of the civil aviation in the country.

References 

Air shows
Civil aviation in India
Organisations based in Hyderabad, India
Recurring events established in 2008
Biennial events
2008 establishments in Andhra Pradesh
Czilim-class hovercraft. The Czilim-class ACV (Project 20910) is a small patrol hovercraft operated by the Border Service of the FSB of Russia.

Configuration 
The Czilim class is the first new class of military hovercraft developed for the Russian military since the fall of the Soviet Union. It is based on an Almaz CMDB design and was ordered from Yaroslavl Shipyard in the late 1990s. It is roughly the same size as the British SR.N6 hovercraft.

The Czilim class was designed for border patrol duties on the Amur River on the border with China, and is expected to be used entirely by Russian border guards. It is intended as a smaller replacement for the Soviet . The first craft was laid down on 24 February 1998 and entered service on 18 September 2000. Three further craft were ordered at Yaroslavl in the late 1990s and early 2000s, though none are currently believed to be completed.

The Czilim class is capable of carrying six border guards and their equipment.

See also
 List of ships of the Soviet Navy
 List of ships of Russia by project number

References

External links 
 
 
 
 
 
 

Ships of the Border Guard Service of Russia
Military hovercraft
Caudron J Marine. The Caudron J Marine was an amphibious, two-seat, biplane equipped with floats and wheels, similar to the earlier Caudron J floatplane.

The Caudron J was essentially a seaplane version of the two-seat Caudron G and single-seat Caudron F. The F, G, and J all followed a similar layout with 2½ bay biplane wings, a tail-unit, with a single fin and rudder, supported on struts attached to the wings at the first inter-plane struts and a central fuselage nacelle housing the cockpit and mounting the tractor engine. Two main floats were strut-supported under the wings and a small tail-float was attached to the tail-unit. Power was supplied by a  Anzani 10-cylinder radial engine.

The three production Caudron J Marine were used by the French Navy (la Marine Française) for reconnaissance and artillery observation. On 8 May 1914, René Caudron flew the second example from a wooden platform erected over a gun turret, on the French Navy cruiser Foudre. The first example was powered by a  Gnome 9 Delta rotary engine, with the remaining two powered by  Gnome 7 Lambda rotary engines.

Variants
Caudron JThe initial 1913 version of the Caudron floatplane with  span and  Anzani 10-cyl radial. Winner of the Deauville contest in August 1913.
Caudron J Marine 1914 production version of the Type J, with 3 examples purchased by the Marine Française

Operators

French Navy

Specifications (variant specified)

References

Further reading

External links
Les hydravions des frères CAUDRON

1910s French military reconnaissance aircraft
Caudron aircraft
Single-engined tractor aircraft
Biplanes
Aircraft first flown in 1914
Rotary-engined aircraft
Level luffing crane. A level-luffing crane is a crane mechanism where the hook remains at the same level while luffing: moving the jib up and down, so as to move the hook inwards and outwards relative to the base.

Usually the description is only applied to those with a luffing jib that have some additional mechanism applied to keep the hook level when luffing.

Level-luffing is most important when careful movement of a load near ground level is required, such as in construction or shipbuilding. This partially explains the popularity of fixed horizontal jibs in these fields.

Toplis cable luffing 

An early form of level-luffing gear was the "Toplis" design, invented by a Stothert & Pitt engineer in 1914. 
The crane jibs luffs as for a conventional crane, with the end of the jib rising and falling. The crane's hook is kept level by automatically paying out enough extra cable to compensate for this. This is also a purely mechanical linkage, arranged by the reeving of the hoist cables to the jib over a number of pulleys at the crane's apex above the cab, so that luffing the jib upwards allows more free cable and lowers the hook to compensate.

Horse-head jibs 

The usual mechanism for level-luffing in modern cranes is to add an additional "horse head" section to the top of the jib. By careful design of the geometry, this keeps level merely by the linked action of the pivots.

Powered level-luffing 
As cranes and their control systems became more sophisticated, it became possible to control the level of luffing directly, by winching the hoist cable in and out as needed. The first of these systems used mechanical clutches between luffing and hoist drums, giving simplicity and a "near level" result.

Later systems have used modern electronic controls and quickly reversible motors with good slow-speed control to the hoist winch motors, so as to give a positioning accuracy of inches. Some early systems used controllable hydraulic gearboxes to achieve the same result, but these added complexity and cost and so were only popular where high accuracy was needed, such as for shipbuilding.

Luffing cabs 
Luffing mechanisms have also been applied to the driver's cab being mounted on its own jib, following the movement of the crane's main jib. These are used for tasks such as ship unloading, where the view from the driver's cab is greatly improved by cantilevering it forwards and over the ship.

Meccano models 
Cranes have long been a popular subject for Meccano models, and luffing cranes are no exception.

References 

Cranes by type
Joe Grand. Joe Grand is an American electrical engineer, inventor and hardware hacker known in the hacker community as Kingpin. He achieved mainstream popularity after his appearance on Prototype This!, a Discovery Channel television show. He specializes in reverse engineering and finding security flaws in hardware devices. Grand has testified before the U.S. Senate Committee on Governmental Affairs regarding government and homeland computer security under his internet handle, Kingpin.

Early life and education 

Grand became involved in electronics at the age of seven and later joined the Boston-based hacker group L0pht Heavy Industries. He gained a Bachelor of Science in Computer Engineering from Boston University. He has published two books and co-authored a number of books relating to hardware hacks and network security.

He received an honorary Doctorate of Science in Technology from the University of Advancing Technology, Arizona.

Television 

In 2007 and 2008, Grand and his three co-presenters (Mike North, Terry Sandin, and "Zoz" Brooks) filmed 13 episodes of Prototype This! which were aired later in 2008 and in early 2009. The show received positive reviews and ratings and Grand continues to host additional features and content on his site.

Business ventures 

After his television appearance, Grand launched Grand Idea Studio, a San Francisco-based research and development firm. In 2009, Grand was a member of a team that demonstrated vulnerabilities in San Francisco's e-parking meters. He is also the sole proprietor of Kingpin Empire, an apparel project that gives back to the community through charitable donations.

Other activities include exhibiting hardware as art in a San Francisco gallery art exhibition titled When Electronics Become Art and designing the electronic badges for DEFCON 2006, 2007, 2008, 2009, and 2010. Grand also served as judge of the Electronic Frontier Foundation's DEFCON badge hack contest, and as an instructor at DEFCON Kids.

Grand remains an active member of the electronics engineering and security communities and is a regular guest speaker at international events, including the Black Hat USA conferences.

References

External links 

Grand Idea Studio website
Prototype This! official site
ZombieTech Interview
Joe Grand Interview on The Amp Hour

1975 births
21st-century American inventors
American electrical engineers
L0pht
Living people
INS Shishumar (S44). INS Shishumar (S44) is the lead vessel of the  of diesel-electric submarines of the Indian Navy. She was commissioned on 22 September 1986 under Commander P M Bhate.

Mid Life Upgrade

Indian Navy awarded $151mn contract for mid-life upgrade and certification of INS Shishumar, the refit will be carried out by Mazagon Dock, Mumbai with technical cooperation from ThyssenKrupp Marine Systems.

The refit is planned to be completed by 2021 with a similar upgrade for another vessel of  to follow.

References

Shishumar-class submarines
Attack submarines
Ships built in Kiel
1984 ships
Submarines of India