omniomni/omni-engineering huggingface dataset:
Caltech Cosmic Cube. The Caltech Cosmic Cube was a parallel computer, developed by Charles Seitz and Geoffrey C Fox from 1981 onward. It was the first working hypercube built.

It was an early attempt to capitalise on VLSI to speed up scientific calculations at a reasonable cost. Using commodity hardware and an architecture suited to the specific task (QCD), Fox and Seitz demonstrated that this was indeed possible.

In 1984 a group at Intel including Justin Rattner and Cleve Moler developed the Intel iPSC inspired by the Cosmic Cube.
In 1987 several people in the group formed a company called Parasoft to commercialize the message passing interface developed for the Cosmic Cube.

Characteristics
 64 Intel 8086/87 processors
 128kB of memory per processor
 6-dimensional hypercube network, i. e. each processor can directly exchange data with six other processors.

References

 The Torus Routing Chip
 Parallel Computer Archival Documents
 John Apostolakis, Clive Baillie, Robert W. Clayton, Hong Ding, Jon Flower, Geoffrey C. Fox, Thomas D. Gottschalk, Bradford H. Hager, Herbert B. Keller, Adam K. Kolawa, Steve W. Otto, Toshiro Tanimoto, Eric F. van de Velde, J. Barhen, J. R. Einstein, and C. C. Jorgensen. 1989. "Supercomputer applications of the hypercube"—In Supercomputing systems: architectures, design, and performance, Svetlana P. Kartashev and Steven I. Kartashev (Eds.). Van Nostrand Reinhold Co., New York, NY, USA:1989 Pages 480–577.

External links
 The C Programmer's Abbreviated Guide to Multicomputer Programming

Parallel computing
Shelving buffer. A shelving buffer is a technique used in computer processors to increase the efficiency of superscalar processors.  It allows for multiple instructions to be dispatched at once regardless of the data dependencies between those instructions. This allows for out-of-order execution to occur which increases the throughput of the microprocessor.

Background
A superscalar processor allows the execution of a number of instructions simultaneously in the core of the processor itself, although this behavior is not to be confused with a multi-processor system. Most modern processors are superscalar. In a superscalar processor multiple instructions are dispatched from the same thread. Multi-core processors contain multiple processors all executing separate threads.

Problems with data dependencies
Executing instructions in parallel (i.e. simultaneously) raises problems with data dependencies, meaning that some instructions may be dependent on the results of others, and hence care must be taken to execute in the correct order.

Take for example these sequence of instructions:

r1 = r2 + r3
r7 = r1 + r4

The update to r7 introduces a (Read After Write) data dependency. The first line of instructions must complete before the second begins execution, as r7 requires the correct value of r1 (register 1) to be known prior to execution. This type of instruction cannot be executed concurrently or simultaneously, the order-of-operations is implicitly serial.

How it works
With a superscalar processor, the instruction window of the processor fills up with a number of instructions (known as the issue rate). Depending on the scheme that the superscalar processor uses to dispatch these instruction from the window to the execution core of the CPU, there may be problems if there is a dependency not unlike the one shown above.

Consider an instruction window 3 instructions wide, containing i1, i2, i3 (instructions 1,2 & 3). Suppose that i2 is dependent on an instruction that has not yet finished executing, and it cannot be executed yet.

Without the use of a shelving buffer, the superscalar processor will execute i1, wait until i2 can be executed and then execute i2 and i3 simultaneously.

However, with the use of a shelving buffer, the instruction window will be emptied into shelving buffers regardless of contents. The processor will then search for an appropriate number of instructions in the shelving buffers that can be executed in parallel (i.e. with no dependencies).

Hence the processor has a greater chance of running the maximum number of instructions simultaneously, and maximising throughput.

References

Parallel computing
LysKOM. LysKOM is a KOM-based conferencing system developed by the Lysator Academic Computer Society at Linköping University and Linköping Institute of Technology. It can be seen as a cross between news and e-mail, but with the presence and speed of IRC or IM-networks. The most common client is the LysKOM Emacs Lisp Client, but among others a WWW-based client also exists. The server and most clients are released under the terms of the GNU General Public License, and thus free software. The LysKOM protocol uses port 4894.

Protocol implementations exist for Python, Perl and Pike. Based on these frameworks, a number of programs for bridging LysKOM with other systems have been written. Notable among these is the Python software for importing and exporting e-mail. Used as a whole, it enables the LysKOM system to act as a primitive list manager. By configuring the exporter to not reexport imported e-mail it is also possible to use LysKOM more like a multi-user e-mail client for posting to mailing lists.

References

External links 
The LysKOM system
The LysKOM Emacs Lisp Client
Note: This page is about the old distribution system. If you want to get a modern client which is being kept up to date with the changes in the servers, use the Daily Build link on the page, referring http://magnus.gustavsson.se/lyskom/beta/src/
LysKOM Protocol A
The Python LysKOM Protocol implementation

Application layer protocols
Linköping University
V20. V20 or V-20 may refer to:

Aircraft 
 Fokker V.20, a Dutch experimental aircraft
 LFG V 20, a German seaplane
 Pilatus UV-20A Chiricahua, an American utility transport aircraft

Automobiles 
 Lexus ES (V20), a Japanese executive car
 Toyota Camry (V20), a Japanese sedan

Electronics 
 Canon V-20, a MSX microcomputer
 NEC V20, a microprocessor
 LG V20, a smartphone

Other uses 
 ATC code V20 Surgical dressings, a subgroup of the Anatomical Therapeutic Chemical Classification System
 V20 engine, an engine with twenty cylinders
 V20, health supervision of infant or child, in the ICD-9 V codes
 Vulnerably Twenty, a bloc of the Climate Vulnerable Forum
Aerial lift pylon. An aerial lift pylon is a pylon construction bearing the cables of an aerial lift such as an aerial tramway or gondola lift. Large pylons of aerial tramways usually consist of a steel framework construction, smaller pylons of gondola lifts are made of tubular steel. Early aerial tramways often had pylons of reinforced concrete and ropeway conveyors had timber pylons, if they were cheaper than steel pylons.

Pylons are not designed as a stopping-off point for passengers or goods, but some are designed to allow maintenance staff access to the cars. Some pylons have built-in ladders or stairs for maintenance access, and some taller examples have an elevator. The best-known and now seventh-tallest pylon is the Torre Jaume I in Barcelona. The tallest gondola lift support tower is the 214,8 m (704,7 ft) Cat Hai – Phu Long cable car which opened in june 2020. The tallest aerial tramway support tower in the world is Tower 2 of Ha Long Queen Cable Car built in 2016 which is 189 m (620 ft) tall.

Tallest pylons

Gallery

See also
 Architectural structure
 List of nonbuilding structure types
 Tower
 Structural engineering

References

External links

 http://en.structurae.de/structures/ftype/index.cfm?ID=4103
  Collection of aerial tramway support pillars on Skyscraperpage.com

Aerial lifts
Pylons
Mosha Pasumansky. Mosha Pasumansky is one of the inventors of the MultiDimensional eXpressions (MDX) language, a query language for online analytical processing (OLAP) databases.  Pasumansky is also one of the architects of the Microsoft Analysis Services, and an OLAP expert.

Mosha Pasumansky is well known in the OLAP community for his Microsoft OLAP information website which contains a collection of technical articles and other resources related to Microsoft OLAP and Analysis Services. He also has a blog dedicated to MDX and Analysis Services. He spoke at Microsoft conferences such as TechEd and PASS, and he published the book Fast Track to MDX.

In December 2009, Pasumansky shifted his focus to Bing, the Microsoft Search Engine. He is no longer maintaining his active stewardship of the BI Community.

From May 2011 to July 2021, Pasumansky worked at Google on the Dremel and BigQuery systems.

Since July 2021, Pasumansky assumed the role of CTO at Firebolt Analytics, an Israel-founded startup aiming to revolutionize the world of data analytics

External links
 Mosha Pasumansky's weblog (archived from http://sqlblog.com/blogs/mosha/default.aspx)

References

Microsoft employees
Living people
Year of birth missing (living people)
Starseed launcher. Starseed is a proposed method of launching interstellar nanoprobes at one-third light speed.

The launcher uses a 1,000 km-long small-diameter hollow wire, with electrodes lining the hollow wire, an electrostatic accelerator tube, similar to K. Eric Drexler's ideas.  The launcher is designed to accelerate its probes to 1/3 the speed of light, about 100,000 kilometers per second, at something on the order of 100 million gravities of acceleration.

Keeping the launch tube straight enough to avoid the probe hitting the tube walls is a major challenge. The launcher would have to be set up in deep space, well away from any planets, to avoid gravitational tide effects bending the tube too much.

The proposed starseed probes would be extremely small (roughly one microgram) nanomachines and nanocomputers. The required launch energy per probe would be low due to the low mass, and many nanoprobes would be launched in sequence and rendezvous in flight.

References 
Reference to Starseed concept in paper from 2010 International Planetary Probe Workshop

Hypothetical spacecraft
Interstellar travel
Nickel(III) oxide. Nickel (III) oxide is the inorganic compound with the formula Ni2O3. It is not well characterized, and is sometimes referred to as black nickel oxide. Traces of Ni2O3 on nickel surfaces have been mentioned.

Nickel (III) oxide has been studied theoretically since the early 1930s, supporting its unstable nature at standard temperatures. A nanostructured pure phase of the material was synthesized and stabilized for the first time in 2015 from the reaction of nickel(II) nitrate with sodium hypochlorite and characterized using powder X-ray diffraction and electron microscopy.

References

Inorganic compounds
Catalysts
Electrochemistry
Transition metal oxides
Nickel compounds
Non-stoichiometric compounds
Sesquioxides
CeNTech. The Center for Nanotechnology is one of the first centers for nanotechnology. It was founded in 2001 and is located in Münster, North Rhine-Westphalia, Germany. It offers many possibilities for research, education, start-ups and companies in nanotechnology. Hence it works together with the University of Münster (WWU), the Max Planck Institute for Molecular Biomedicine and many more research institutions.

External links
 CeNTech Homepage

2001 establishments in Germany
Nanotechnology institutions
Research institutes established in 2001
Research institutes in North Rhine-Westphalia
University of Münster
Marine canvas. Marine canvas refers to a varied array of fabrics used in the fabrication and production of awnings, covers, tarps, sunshades, signs and banners for the advertising, boating, trucking, tenting, structural and medical industries. The term "marine canvas" is also used more narrowly to refer specially to boat cover products.  

When referring to materials "marine canvas" is a catch–all phrase that covers hundreds of materials, for instance: acrylics, PVC coated polyester, silicone treated substrates and many coated meshes suitable for outdoor use. Most ¨marine canvas¨ materials offer good UV resistance, and, to some extent, water resistance or waterproofness.  Two of the most popular fabrics used today are solution dyed acrylic canvas such as Sunbrella and PVC coated woven polyester such as Stamoid. Such synthetic fabrics can last for many years before deteriorating due to UV radiation. Marine canvas is typically used to protect materials susceptible to UV damage like varnished wood, non-UV resistant plastics, and outdoor stored sails. Other boat specific uses include hatch covers for interior sun protection and winch covers for protection from deterioration and fouling due to seawater, rain, and dirt exposure. 

Products often referred to as "marine canvas" and made from "marine canvas" include biminis, dodgers, and similar enclosures that protect some part or section of a boat from the weather and/or to create a more comfortable environment for the boat user(s). These types of products can also include additional features such as transparent windows, lights, or storage. In some instances, these covers are also created purely, or in part, for aesthetic purposes.

The design of these covers requires the fabricator to create a custom pattern for the frame or object being covered. This can be done via careful measurement, but more commonly the finial material or a disposable templating material (typically paper or plastic sheet) is laid directly over the frame or object and then marked. Marks for cuts, seams, fasteners and chafe protection are applied to the pattern, which is then either used directly or transferred to the finial material from the templating material.

The thread used to stitch modern marine type canvas is typically made from Polyester or PTFE with sizes ranging from #69, #92, #138. Polyester thread is widely available and relatively low cost compared to PTFE, but PTFE thread has become increasingly popular due to its far greater resistance to ultraviolet radiation a chemical decomposition in a marine environment. This increased durability also adds lifespan as thus cost effectiveness to the finial product helping to offset the initially higher cost. Nylon and natural fiber thread is rarely used as neither have UV resistance comparable to Polyester or PTFE.

See also
 Sail

References

Sailboat components
Maritime culture
Lotus M90. The Lotus M90 (sometimes referred to as the Lotus X100) is a concept car that was developed by Lotus using many Toyota parts. Rumors were circulated that it was the initial design for the MKI MR2, but, though sharing an engine, it bears very little resemblance to the mid-engine roadster. The project was the last one overseen by Lotus founder Colin Chapman before his death in 1982.

In 1981, Oliver Winterbottom was brought back to Lotus, after a stint developing the Tasmin for TVR, to design a new car to complement the Excel and the Esprit and bring some profitability to the lineup. The new car was to resurrect the Elan name which had not been used since 1975 and, like the Excel, make use of the company's close relationship with Toyota to use already well-engineered suspension and engine components. Initial designs were a coupé that didn't get much of an enthusiastic response from the board of the company. The project stalled when company founder Colin Chapman died in 1982, as Lotus found itself in financial trouble. David Wickens of British Car Auctions ended up taking a controlling interest in the company, and the project was started up again, but renamed to the X100 (the Elan later being known as the M100). After redesigning the car to be a convertible the go ahead was given in 1984 to make a single prototype. It was built to a high level of finish, but by that time most of the company's engineers were concentrating on the new front-wheel-drive Elan, and the prototype was warehoused at the company's factory. In 1998 it was auctioned off along with several other rare Lotus cars, and sold to a private collector, and shipped to the United States.

The M90 makes use of a front-mounted 1.6L  4-cylinder Toyota engine, as well as a Toyota-built 5-speed transmission and final drive. The suspension uses the same setup as is found in the Lotus Excel. The instrument cluster is from an Opel Monza and the radiator is from an Austin Allegro. The rear lights are borrowed from the Aston Martin Lagonda and the indicators are from the Ford Fiesta. The body is made of fibreglass and the roof is lowered in two pieces. The top is removed separately and fits in the boot, to create a 'targa' style roof, and the rear portion folds down like a typical convertible.

This car is featured in a book released in June 2017 by Oliver Winterbottom titled A Life in Car Design, in which the author provides insight into the design and construction of the M90 along with photographs and related documentation.

References 

Lotus Elan M90

M90
Concept cars
SS-50 bus. The SS-50 bus was an early computer bus designed as a part of the SWTPC 6800 Computer System that used the Motorola 6800 CPU. The SS-50 motherboard would have around seven 50-pin connectors for CPU and memory boards plus eight 30-pin connectors for I/O boards. The I/O section was sometimes called the SS-30 bus.

Southwest Technical Products Corporation introduced this bus in November 1975 and soon other companies were selling add-in boards. Some of the early boards were  floppy disk systems from Midwest Scientific Instruments, Smoke Signal Broadcasting, and Percom Data; an EPROM programmer from the Micro Works; video display boards from Gimix; memory boards from Seals. By 1978 there were a dozen SS-50 board suppliers and several compatible SS-50 computers.

In 1979 SWTPC modified the SS-50 bus to support the new Motorola MC6809 processor. These changes were compatible with most existing boards and this upgrade gave the SS-50 Bus a long life. SS-50 based computers were made until the late 1980s.

The SS-50C bus, the S/09 version of the SS-50 bus, extended the address by four address lines to 20 address lines to allow up to a megabyte of memory in a system.

Boards for the SS-50 bus were typically 9 inches wide and 5.5 inches high. The board had Molex 0.156 inch connectors while the motherboard had the pins. This arrangement made for low cost printed circuit boards that did not need gold plated edge connectors. The tin plated Molex connectors were only rated for a few insertions and were sometimes a problem in hobbyist systems where the boards were being swapped often. Later systems would often come with gold plated Molex connectors.

The SS-30 I/O Bus had the address decoding on the motherboard. Each slot was allocated 4 address (the later MC6809 version upped this to 16 address.) This made for very simple I/O boards, the Motorola peripheral chips connected directly to this bus. Cards designed using the SS-30 bus often had their external connectors mounted such that they were accessible outside the computer chassis when installed in SWTPC motherboards.

SS-50 and SS-30 gallery
Click the images to enlarge.

References

Computer buses
SS-50
Heathrow Airside Road Tunnel. The Heathrow Airside Road Tunnel (ART) is a tunnel at Heathrow Airport. It connects the airside roads around Terminals 1, 2 and 3 to those around Terminal 5. The tunnel was opened to traffic in March 2005 and is used only by vehicles with security clearance to drive airside.

The ART is  long, consisting of  of twin-cell cut and cover box at each end, linked by a pair of  long bored tunnels. The ART was designed and built between 1999 and 2004 by a team of engineers from the BAA (the tunnel's owner), Amec, Laing O'Rourke, Morgan Est-Vinci and Mott MacDonald.

The bored tunnels have internal diameter of  and were driven by a  diameter Herrenknecht earth pressure balance tunnel boring machine. The excavations were lined with a bolted concrete lining  thick: these are unusually strong tunnel segments, required because the ART is so close to the surface and, at one point, passes  over the top of the Heathrow Express tunnel to Terminal 4.

Each bore contains an unusual road layout, consisting of a single carriageway  wide; just wide enough to allow an airport bus (Cobus 2700) to drive past another bus stopped at the side of the road. The two tunnels are linked by escape cross-passages at intervals of .

Portals
West portal: 
East portal:

Sources
 Challenging ART for Heathrow, World Tunnelling August 2003, pp. 225–229
 Darby, A., The Airside Road Tunnel, Heathrow Airport, England, Proceedings of the Rapid Excavation & Tunneling Conference, New Orleans, June 2003, pp. 638–647
 Morgan Est project page on T5

External links
 Mott MacDonald page on the Heathrow Airside Road Tunnel
 Engineering the space below Terminal 5, Ingenia magazine, March 2008 

Airside Road Tunnel Heathrow Airside Road Tunnel
Tunnels completed in 2004
Road tunnels in England
Transport in the London Borough of Hillingdon
Airside Road Tunnel
Tunnels in London
2004 establishments in England
Frederick Palmer. Frederick Palmer may refer to:
Frederick Palmer (engineer) (1860–1934), British civil engineer
Frederick Palmer (journalist) (1873–1958), American writer and war correspondent
Frederick William Palmer (1891–1955), World War I Victoria Cross recipient
Frederick Christian Palmer (1866–1941), photographer
Frederick F. Palmer (1925–1992), U.S. Navy admiral
Frederick John Palmer, English photographer
F. W. J. Palmer (1864–1947), English civil engineer, structural engineer and surveyor
Demjanov rearrangement. The Demjanov rearrangement is the chemical reaction of primary amines with nitrous acid to give rearranged alcohols. It involves substitution by a hydroxyl group with a possible ring expansion. It is named after the Russian chemist Nikolai Jakovlevich Demjanov (Dem'anov, Demianov), who first reported it in 1903.

Reaction mechanism
The reaction process begins with diazotization of the amine by nitrous acid. The diazonium group is a good leaving group, forming nitrogen gas when displaced from the organic structure. This displacement can occur via a rearrangement (path A), in which one of the sigma bonds adjacent to the diazo group migrates. This migration results in an expansion of the ring. The resulting carbocation is then attacked by a molecule of water. Alternately, the diazo group can be displaced directly by a molecule of water in an SN2 reaction (path B). Both routes lead to formation of an alcohol.

Uses
The Demjanov rearrangement is a method to produce a 1-carbon ring enlargement in four, five or six membered rings. The resulting five, six, and seven-membered rings can then be used in further synthetic reactions.

It has been shown that the Demjanov reaction is susceptible to regioselectivity. One example of this is a study conducted by D. Fattori looking at the regioselectivity of the Demjanov rearrangement in one-carbon enlargements of naked sugars. It showed that when an exo methylamine underwent Demjanov nitrous acid deamination, ring enlargement was not produced.

However, when the endo methylamine underwent the same conditions, a mixture of rearranged alcohols were produced.

Problems
This rearrangement also leads to a substituted, but not expanded, byproduct. Thus it can be difficult to isolate the two products and acquire the desired yield. Also, stereoisomers are produced depending on the direction of addition of the water molecule and other molecules may be produced depending on rearrangements.

Variations

Tiffeneau-Demjanov rearrangement
The Tiffeneau-Demjanov rearrangement (after Marc Tiffeneau and Nikolai Demjanov) is a variation of the Demjanov rearrangement, which involves both a ring expansion and the production of a ketone by using sodium nitrite and hydrogen cation. Using the Tiffeneau-Demjanov reaction is often advantageous as, while there are rearrangements possible in the products, the reactant always undergoes ring enlargement. As in the Demjanov rearrangement, products illustrate regioselectivity in the reaction. Migratory aptitudes of functional groups dictate rearrangement products.

Use of diazomethane
Diazomethane also produces ring enlargement, and its reaction is mechanistically similar to the Tiffeneau-Demjanov rearrangement.

References
  
  
   (Review)
  
 
 
 
 
 
 
 
 

Rearrangement reactions
Name reactions