omniomni/omni-engineering huggingface dataset:
FROSTBURG. FROSTBURG was a Connection Machine 5 (CM-5) massively parallel supercomputer used by the US National Security Agency (NSA) to perform mathematical calculations. The CM-5 was built by the Thinking Machines Corporation, based in Cambridge, Massachusetts, at a cost of US$25 million. The system was installed at NSA in 1991, and operated until 1997. It was the first massively parallel processing computer bought by NSA, originally containing 256 processing nodes. The system was upgraded in 1993 with another 256 nodes, for a total of 512 nodes. The system had a total of 500 billion 32-bit words (≈ 2 terabytes) of storage, 2.5 billion words (≈ 10 gigabytes) of memory, and could perform at a theoretical maximum 65.5 gigaFLOPS. The operating system CMost was based on Unix, but optimized for parallel processing.

FROSTBURG is now on display at the National Cryptologic Museum.

See also 
 HARVEST
 Cryptanalytic computer

References

External links 
 Another photograph of FROSTBURG by Declan McCullagh

Cryptanalytic devices
Supercomputers
Salicylaldehyde. Salicylic aldehyde (2-hydroxybenzaldehyde) is an organic compound with the formula . Along with 3-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, it is one of the three isomers of hydroxybenzaldehyde. This colorless oily liquid has a bitter almond odor at higher concentration. Salicylaldehyde is a precursor to coumarin and a variety of chelating agents.

Production 
Salicylaldehyde is produced by condensation of phenol with formaldehyde to give hydroxybenzyl alcohol, which is oxidized to the aldehyde.
Salicylaldehydes in general are prepared by ortho-selective formylation reactions from the corresponding phenol, for instance by the Duff reaction, Reimer–Tiemann reaction, or by treatment with paraformaldehyde in the presence of magnesium chloride and a base.

Natural occurrences 
Salicylaldehyde is a characteristic aroma component of buckwheat. Salicylaldehyde also occurs in the larval defensive secretions of several leaf beetle species that belong the subtribe Chrysomelina. An example for a leaf beetle species that produces salicylaldehyde is the red poplar leaf beetle Chrysomela populi.

Reactions and applications 
Salicylaldehyde is mainly used commercially as a precursor to coumarin.  The conversion entails condensation with acetic anhydride ("Perkin synthesis").

Oxidation with hydrogen peroxide gives catechol (1,2-dihydroxybenzene) (Dakin reaction). 
Etherification with chloroacetic acid followed by cyclisation gives the heterocycle benzofuran (coumarone).  The first step in this reaction to the substituted benzofuran is called the Rap–Stoermer condensation after E. Rap (1895) and R. Stoermer (1900).
Salicylaldehyde is converted to chelating ligands by condensation with amines. With ethylenediamine, it condenses to give the ligand salen. Hydroxylamine gives salicylaldoxime. 
Condensation with diethyl malonate gives 3-carbethoxycoumarin (a derivative of coumarin) by an aldol condensation.
Elbs persulfate oxidation gives gentisaldehyde (2,5-dihydroxybenzaldehyde).

Internal hydrogen bonding 
Due to the ortho positioning of the hydroxy- and aldehyde groups, an internal hydrogen bond is formed between the groups. The hydroxy group serves here as the hydrogen bond donor, and the aldehyde as hydrogen bond acceptor. This internal hydrogen is not found in the other hydroxybenzaldehyde isomers. 
When the aldehyde is reacted with an amine to form an imine, the internal hydrogen bond is even stronger. In addition, tautomerisation further increases the stability of the compound. The internal hydrogen bond also ensures that the aldehyde (or corresponding imine) is held into the same plane, making the whole molecule essentially flat.

References 

Flavors
Hydroxybenzaldehydes
2-Hydroxyphenyl compounds
Coil. Coil or COIL may refer to:

Geometry
 Helix, a space curve that winds around a line
 Spiral, a curve that winds around a central point

Science and technology
 Coil (chemistry), a tube used to cool and condense steam from a distillation
 Coil spring, used to store energy, absorb shock, or maintain a force between two surfaces
 Inductor or coil, a passive two-terminal electrical component
 Electromagnetic coil, formed when a conductor is wound around a core or form to create an inductor or electromagnet
 Induction coil, a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current supply
 Ignition coil, used in internal combustion engines to create a pulse of high voltage for a spark plug
 Intrauterine device or coil, a contraceptive device
 Chemical oxygen iodine laser, a near–infrared chemical laser
 Coil, a binary digit or bit in some communication protocols such as Modbus
 COIL, the gene that encodes the protein coilin
 Coiled tubing, a long metal pipe which is supplied spooled on a large reel

Music
 Coil (band), an English experimental band
 Coil (album), a 1997 album by Toad the Wet Sprocket
 "Coil", a song by Opeth from Watershed

Fictional entities
 The Coil, a fictional organization in the G.I. Joe universe
 Magnemite or Coil, a Pokémon character
 Coil, a crime lord from the web serial Worm

People with the surname
Alison Coil, American astrophysicist
 Liam Mac Cóil, Irish novelist

Other uses
 Coil (hieroglyph), an Egyptian hieratic hieroglyph
 Coiled basketry, using grasses, rushes and pine needles
 Coiling (pottery), a method of creating pottery
 Coil (video game), a video game by Edmund McMillen and Florian Himsl
 Turmoil or burden, as in mortal coil
 Coiling, a method for storing rope or cable

See also
 Helix (disambiguation)
 Loop (disambiguation)
 Spiral (disambiguation)
Pedalo. A pedalo (British English), pedal boat (U.S. English), or paddle boat (U.S., Canadian, and Australian English) is a human-powered watercraft propelled by the action of pedals turning a paddle wheel.

Description
A pedalo is a human-powered watercraft propelled by the turning of a paddle wheel. The wheel is turned by people operating the pedals of the craft. The paddle wheel of a pedalo is a smaller version of that used by a paddle steamer.

Use
Pedalos, being particularly suited to calm waters, are often hired out for use on ponds and small lakes in urban parks, as well as in beaches when the weather allows.

Designs
The earliest record of a pedalo is perhaps Leonardo da Vinci's diagram of a craft driven by two pedals.

Typically, a two-seat pedalo has two sets of pedals side-by-side, designed to be used together. Some models, however, have three pedals on each side, to allow a person boating alone to pedal from a centrally seated position.

References

External links
 

Boat types
Human-powered watercraft
Water sports
Water sports equipment
Hot runner. A hot runner system is an assembly of heated components used in plastic injection molds that inject molten plastic into the cavities of the mold. (The cavities are the part of the mold shaped like the parts to be produced.)

By contrast, a cold runner is simply a channel formed between the two halves of the mold, for the purpose of carrying plastic from the injection molding machine nozzle to the cavities. Each time the mold opens to eject the newly formed plastic parts, the material in the runner is ejected as well, resulting in waste. A hot runner system usually includes a heated manifold and a number of heated nozzles. The main task of the manifold is to distribute the plastic entering the mold to the various nozzles which then meter it precisely to the injection points in the cavities.

Hot runner advantages 
 Shorter cycle time: No runner controlling the cooling time
 Easier to start: Without runners to remove, and auto cycle occurs faster and more frequently
 Fewer sink marks and under-filled parts: Unlike when plastic flows through a cold runner and loses heat to mold plates
 Design flexibility: Can locate the gate at many points on the part
 Balanced melt flow: Separate melt channels are in externally heated manifolds that are insulated from mold plates surrounding them.
Hot runner systems were first developed and came into sporadic use in the early 60s with generally negative results. They gained popularity in the 80s and 90s as technological advancements allowed improved  reliability and the escalation of plastic materials prices made hot runner systems more desirable and cost effective. Hot runners are fairly complicated systems, they have to maintain the plastic material within them heated uniformly, while the rest of the injection mold is being cooled in order to solidify the product quickly. For this reason they are usually assembled from components pre manufactured by specialized companies. 

A hot runner controller is a temperature controller used to control the temperature in the hot runner. This helps  create the most consistent part(s).

Hot runners usually make the mold more expensive to manufacture and run, but generate savings by reducing non-productive plastic and allowing shorter cycle time. (do not have to wait until the conventional runners freeze).

References

See also
Cartridge heater
Plastic Injection Molding

Plastics industry
Injection molding
List of game engine recreations. Game engine recreation is a type of video game engine remastering process wherein a new game engine is written from scratch as a clone of the original with the full ability to read the original game's data files. The new engine reads the old engine's files and, in theory, loads and understands its assets in a way that is indistinguishable from the original. The result of a proper engine clone is often the ability to play a game on modern systems that the old game could no longer run on. It also opens the possibility of community collaboration, as many engine remake projects tend to be open source.

In most cases a clone is made in part by studying and reverse engineering the original executable, but occasionally, as was the case with some of the engines in ScummVM, the original developers have helped the projects by supplying the original source code—those are so-called source ports.

See also

 List of commercial video games with later released source code
 Source port
 Video game remake
 Emulator

References

External links
 Open Source Game Clones, specialized in open source variants of commercial games

 
Game engines for Linux
Open-source video games
Entropy of activation. In chemical kinetics, the entropy of activation of a reaction is one of the two parameters (along with the enthalpy of activation) that are typically obtained from the temperature dependence of a reaction rate constant, when these data are analyzed using the Eyring equation of the transition state theory. The standard entropy of activation is symbolized  and equals the change in entropy when the reactants change from their initial state to the activated complex or transition state ( = change,  = entropy,  = activation).

Importance 
Entropy of activation determines the preexponential factor  of the Arrhenius equation for temperature dependence of reaction rates. The relationship depends on the molecularity of the reaction: 
 for reactions in solution and unimolecular gas reactions
 , 
 while for bimolecular gas reactions
 .

In these equations  is the base of natural logarithms,  is the Planck constant,  is the Boltzmann constant and  the absolute temperature.  is the ideal gas constant. The factor is needed because of the pressure dependence of the reaction rate.  = .

The value of  provides clues about the molecularity of the rate determining step in a reaction, i.e. the number of molecules that enter this step.  Positive values suggest that entropy increases upon achieving the transition state, which often indicates a dissociative mechanism in which the activated complex is loosely bound and about to dissociate. Negative values for  indicate that entropy decreases on forming the transition state, which often indicates an associative mechanism in which two reaction partners form a single activated complex.

Derivation 
It is possible to obtain entropy of activation using Eyring equation. This equation is of the form

where:
  = reaction rate constant
  = absolute temperature
  = enthalpy of activation
  = gas constant
  = transmission coefficient
  = Boltzmann constant = R/NA, NA = Avogadro constant
  = Planck constant
  = entropy of activation

This equation can be turned into the formThe plot of  versus  gives a straight line with slope  from which the enthalpy of activation can be derived and with intercept  from which the entropy of activation is derived.

References 

Chemical kinetics
S1850M. The S1850M is a long-range radar with a digital antenna array for wide area search in elevation. The S1850M is manufactured by Thales and BAE Systems Integrated System Technologies (formerly AMS UK). It is a modified version of the Thales Nederland SMART-L radar. The S1850M is advertised as being capable of fully automatic detection, track initiation, and tracking of up to 1,000 targets at a range of . It is also claimed to be highly capable of detecting stealth targets, and able to detect and track outer atmosphere objects at short range, enabling it to form part of a Theatre Ballistic Missile Defence system.

The contract for initial production of the S1850M was signed in 2001: two for the UK, one for France, and one for Italy, with a common prototype based in Toulon. In 2005, a follow-on contract was signed for five more for the UK, one more for France, and one more for Italy.

A further developed version of the Smart-L is being installed on ships by the Royal Netherlands Navy, which is an updated version of the current SMART-L radar called the SMART-L-EWC (Early Warning Capability) Radar. It has a greater search radius: a tracking range of 2000 km for ballistic missiles and 480 km for air targets. SMART-L EWC is a programmable AESA radar that is characterized by full flexibility. Additional capabilities can be introduced during its lifetime according to customer needs. This makes the radar future-proof in case of evolving requirements.

Applications
 UK Royal Navy: Type 45 destroyer and 
 France: 
 Italy: Orizzonte-class destroyer

In all its current applications, the S1850M is the long-range radar (LRR) component of the Principal Anti-Air Missile System. On the Type 45 destroyers, it is paired with the SAMPSON multifunction radar; on the Horizon ships, it is paired with the EMPAR multifunction radar.

On 11 February 2009, Thales indicated that the S1850M radar will be fitted on the Royal Navy's Queen Elizabeth-class aircraft carrier.

References

External links
BAE article
Thales SMART-L-EWC
Royal Netherlands Navy signs agreement to upgrade 4 existing SMART-L radars with Early Warning Capability 

Naval radars
Military radars of the United Kingdom
Military radars of France
Royal Navy Radar
Phased array radar
Military equipment introduced in the 2000s
MODTRAN. MODTRAN (MODerate resolution atmospheric TRANsmission) is a computer program designed to model atmospheric propagation of electromagnetic radiation for the 100-50,000 cm−1 (0.2 to 100 μm) spectral range.  This covers the spectrum from middle ultraviolet to visible light to far infrared. 

The most recently released version of the code, MODTRAN6, provides a spectral resolution of 0.2 cm−1 using its 0.1 cm−1 band model algorithm.

Some aspects of MODTRAN are patented by Spectral Sciences, Inc. and the US Air Force, who have shared development responsibility for the code and related radiation transfer science collaboratively since 1987.  The acronym MODTRAN was registered as a trademark of the US Government, represented by the US Air Force, in 2008.

All MODTRAN code development and maintenance is currently performed by Spectral Sciences while the Air Force handles code validation and verification.  MODTRAN6 may be obtained from Spectral Sciences, Inc.

MODTRAN is written entirely in FORTRAN.  MODTRAN6 adds support for JSON formatted input files, along with a graphical user interface that enables users to load existing cases, interactively enter or modify inputs, save their JSON formatted input files, run MODTRAN6, and graphically view the newly generated spectral output data.  Third parties, including Ontar, have also developed graphical user interfaces for MODTRAN in order to facilitate user interaction and ease of use.

See also
 HITRAN - a compilation of spectroscopic parameters 
 List of atmospheric radiative transfer codes
 SMARTS - Simple Model of the Atmospheric Radiative Transfer of Sunshine

External links
 MODTRAN web site 
 USAF patent 5884226
 USAF patent 7433806
 Google scholar papers on MODTRAN
 Main Page Air Force Site

Electromagnetic radiation
Fortran libraries
Atmospheric radiative transfer codes
Ultrasone. Ultrasone AG is a German company specializing in headphones for high end studio, DJ, and consumer uses. Ultrasone's headquarters are located in Tutzing, Germany.

Overview
Ultrasone AG was founded as German GmbH in December 1990 by Florian M. König with the stated objective to manufacture advanced headphones with an emphasis on the professional audio sector. A feature of many Ultrasone headphones is a proprietary surround-sound simulacrum technology called S-Logic. The process uses decentralized transducer positioning to spread sound over the outer ear in an attempt to mimic sound heard over speakers. Traditional headphones shoot the sound directly into the ear.

Since 1999, Ultrasone AG has been producing headphones that they claim reduce the risk of hearing damage, through the use of more efficient transducers and earcups shielded to reduce electromagnetic radiation, designated as LE/ULE (Low/Ultralow Emission). Ultrasone claims that magnetic fields so close to the head could contribute to "listener fatigue" and might be "a potential health hazard". According to Ultrasone, their headphones reduce magnetic emissions by up to 98 percent compared to other headphones.

See also
 Electrical sensitivity

References

External links
 ULTRASONE website
 
 ULTRASONE shop

Headphones manufacturers
Manufacturing companies established in 1990
German brands
Audio equipment manufacturers of Germany
1990 establishments in Germany
Flame polishing. Flame polishing, also known as fire polishing, is a method of polishing a material, usually glass or thermoplastics, by exposing it to a flame or heat. When the surface of the material briefly melts, surface tension smooths the surface. Operator skill is critical with this method. When done properly, flame plastic polishing produces the clearest finish, especially when polishing acrylic. This method is most applicable to flat external surfaces. Flame polishing is frequently used in acrylic plastic fabrication because of its high speed compared to abrasive methods. In this application, an oxyhydrogen torch is typically used, one reason being that the flame chemistry is unlikely to contaminate the plastic.

Flame polishing is essential to creation of the glass pipettes used for the patch clamp technique of voltage clamping.

Equipment 
Various machines and torches/gas burners are used in the flame polishing process. Depending on the heating requirements for an intended application, different kinds of gases are used including but not limited to: natural gas, propane and oxygen, oxygen and hydrogen. A specially designed machine called the hydro flame is commonly used in flame polishing. The hydro flame is a gas-powered generator that uses distilled water and electricity to create oxygen and hydrogen for its flame. The size, shape, and chemistry of the flames used in fire polishing can vary widely based on the type and shape of the material being polished.

See also 
 Fire hardening, also known as "fire polishing", a primitive process for hardening wood

References 

Glass production
Plastics industry
Boiled wool. Boiled wool is a type of fabric primarily used in creating berets, scarves, vests, cardigans, coats, and jackets. To create this fabric, knit wool or wool-blend fabrics are agitated with hot water in a process called fulling. This process shrinks the fabric and results in a dense felted fabric that resists fraying and further shrinkage.

Origins
Boiled wool is a type of felted wool, and is similar to non-woven wool felt. These processes date at least as far back as the Middle Ages. The word felt itself comes from West Germanic feltaz. Boiled/felted wool is characteristic of the traditional textiles of South America and Tyrolean Austria. It is produced industrially around the world.

Process
Boiled wool fabric is created commercially by first knitting wool yarns to create a fabric of uniform thickness. The yarns and fabric may either be dyed or left natural, and the fabric may include designs or embellishments. After knitting, the fabric is fulled by boiling and agitating in hot water and an alkaline solution like soap. The agitation causes the scaly surface of wool fibers to stick together, producing a felted fabric. The result is a tighter and denser material that is up to 50% smaller in all directions than the pre-felted fabric. Boiled wool is warm, durable, and resistant to water and wind.

The general process of felting can be used to process non-woven fibers into pieces of felt used in industry, medical applications, and for crafts and costumes. This can be performed using a variety of fibers, including wool blends, rayon, polyester, and acrylic.

See also
Fulling
Loden cape

References 

Knitted fabrics
Woven fabrics
Waulked textiles
Niterói-class frigate. The Niterói class is a series of frigates of the Brazilian Navy built by Vosper Thornycroft of the United Kingdom and Arsenal de Marinha do Rio de Janeiro based on the Type 21 frigates.

History 
These frigates were designated the Mk 10 by Vosper Thornycroft and are the largest of a series of ships built by that shipyard for both foreign buyers and the Royal Navy. All of them were extensively modernized between 1996 and 2005 under the 'ModFrag' program. The projected completion was 2001, but due to lack of funds and sea trials to verify the new software, the entire program had been slipped to 2005.

A total of six ships were built. Two of the anti-submarines (ASW) and both of the general purpose (GP) version were built in England. The remaining two ASW ships were built at the Arsenal da Marinha in Rio de Janeiro with assistance from VT. The ASW ships had an Ikara missile launcher in Y position aft of the flight deck. This was removed as part of the modernisation programme. The GP ships had a second  gun in "Y" position. A seventh ship was built as the navy's main training unit. The ship is identical to the other ships of the class, but is not fitted with weapons or sensors.

From 2025, the class will be gradualy replaced in "first-rank" roles by the newest  frigates, the survivors will be revitalized and transferred to patrol duties in the fleet.

Ships of the class

Gallery

References

Bibliography 
Marinha do Brasil (Brazilian Navy)
Conway's All the World's Fighting Ships 1947–1995
Cicalesi, J.C. e Del Gaizo, Cesar: La Marina brasiliana oggi, RiD magazine, Chiavari, June 2006, pag. 50–55
Saunders, Stephen. Jane's Fighting Ships 2002–2003. Coulsdon, UK: Jane's Information Group, 2002. .

 
Frigate classes
Frigates of the Brazilian Navy
Ships built in Brazil
Tools for Thought. Tools for Thought: The History and Future of Mind-Expanding Technology is a work of "retrospective futurism" in which Smart Mobs author Howard Rheingold looked at the history of computing and then attempted to predict what the networked world might look like in the mid-1990s. The book covers the groundbreaking work of thinkers like Alan Turing, John von Neumann, and J.C.R. Licklider, as well as Xerox PARC, Apple Computer, and Microsoft (when Microsoft was "aiming for the hundred-million-dollar category").  Rheingold wrote that the impetus behind Tools for Thought was to understand where "mind-amplifying technology" was going by understanding where it came from.

External links
MIT Press printed a revised edition of "Tools for Thought" in April 2000.
Rheingold.com has the original 1985 text available online.

History of computing