omniomni/omni-engineering huggingface dataset:
Carbothermic reaction. Carbothermic reactions involve the reduction of substances, often metal oxides (O2-), using carbon (C) as the reducing agent. The reduction is usually conducted in the electric arc furnace or reverberatory furnace, depending on the metal ore. These chemical reactions are usually conducted at temperatures of several hundred degrees Celsius. Such processes are applied for production of the elemental forms of many elements. The ability of metals to participate in carbothermic reactions can be predicted from Ellingham diagrams.

Carbothermal reactions produce carbon monoxide (CO) and sometimes carbon dioxide (CO2).  The facility of these conversions is attributable to the entropy of reaction: two solids, the metal oxide (and flux) and carbon, are converted to a new solid (metal) and a gas (CO), the latter having high entropy.

Applications 

A prominent example is that of  iron ore smelting. Many reactions are involved, but the simplified equation is usually shown as:

 2  + 3 C → 4 Fe + 3 

On a more modest scale, about 1 million tons of elemental phosphorus is produced annually by carbothermic reactions.  Calcium phosphate (phosphate rock) is heated to 1,200–1,500 °C with sand, which is mostly , and coke (impure carbon) to produce . The chemical equation for this process when starting with fluoroapatite, a common phosphate mineral, is:

 4   +  18   +  30 C →  3   +  30 CO  +  18   +  2 

Of historic interest is the Leblanc process.  A key step in this process is the reduction of sodium sulfate with coal:
 Na2SO4 + 2 C → Na2S + 2 CO2

The Na2S is then treated with calcium carbonate to give sodium carbonate, a commodity chemical.

Recently, development of the 'MagSonic' carbothermic magnesium process has restarted interest in its chemistry:

   +   ↔     +  

The reaction is readily reversible from its product vapors, and requires rapid cooling to prevent back-reaction.

Silicon 
Metallurgical grade silicon may also be obtained by carbothermic reaction. The overall reaction is following:

   +   ↔     +  
The actual reaction given is more complex than it seems and includes several steps.

Variations 
Sometimes carbothermic reactions are coupled to other conversions.  One example is the chloride process for separating titanium from ilmenite, the main ore of titanium. In this process, a mixture of carbon and the crushed ore is heated at 1000 °C under flowing chlorine gas, giving titanium tetrachloride:

 2   +  7   +  6 C → 2  + 2  + 6 CO

For some metals, carbothermic reactions do not afford the metal, but instead give the metal carbide.  This behavior is observed for titanium, hence the use of the chloride process.  Carbides also form upon high temperature treatment of  with carbon.  For this reason, aluminium is employed as the reducing agent.

References 

Chemical reactions
Calciothermic reaction. Calciothermic reactions are metallothermic reduction reactions (more generally, thermic chemical reactions) which use calcium metal as the reducing agent at high temperature.

Calcium is one of the most potent reducing agents available, usually drawn as the strongest oxidic reductant in Ellingham diagrams, though the lanthanides best it in this respect in oxide processes. On the other hand, this trend does not continue to other compounds that are non-oxides, and for instance lanthanum is produced by the calciothermic reduction of the chloride, calcium being a more potent reducing agent than lanthanum involving chlorides.

Calciothermic processes are used in the extraction of metals such as uranium, zirconium, and thorium from oxide ores.

An interesting way of performing calciothermic reductions is by in-situ generated metallic calcium, dissolved in molten calcium chloride, as shown in the FFC Cambridge Process.

See also 

 Aluminothermic reaction
 Silicothermic reaction

References 

Inorganic reactions
Metallurgy
Ballistic parachute. A ballistic parachute, ballistic reserve parachute, or emergency ballistic reserve parachute, is a parachute ejected from its casing by a small explosion, much like that used in an ejection seat. The advantage of the ballistic parachute over a conventional parachute is that it ejects the parachute canopy (oftentimes via a small rocket), causing it to open rapidly, thus making it ideal for attaching to light aircraft, hang gliders and microlights, where an emergency may occur in close proximity to the ground. In such a situation, a conventional parachute would not open quickly enough.

In 1982, Comco Ikarus developed the FRS rocket-launched parachute system for its ultralight and hanglider aircraft. In 1999, Cirrus Aircraft (then known as Cirrus Design) provided the first ballistic parachutes as standard equipment on their line of type-certified aircraft, the Cirrus SR20; and in 2016, the company delivered the Cirrus Vision SF50, the first jet aircraft with a ballistic parachute. The Curti Zefhir is the first helicopter fitted with a ballistic parachute, successfully tested in 2018.

See also
 Ballistic Recovery Systems – manufacturer of ballistic parachutes for use in light aircraft
 Scott D. Anderson – test pilot who flight tested the first certified ballistic parachute

Notes and references

Parachuting
Safety equipment
Bromellite. Bromellite, whose name derives from the Swedish chemist Magnus von Bromell (1670–1731), is a white oxide mineral. The mineral form of beryllium oxide, it is found in complex pegmatitic manganese-iron deposits, but is more frequently made synthetically. This is a rare mineral to encounter in its natural state, but it has been made synthetically for over 40 years.

Uses of bromellite
Bromellite, as a beryllium-containing mineral, has some uses. Industrially, natural specimens have the potential to be an ore of beryllium. It is one of the reagents that can be used in the manufacture of artificial emeralds. As an additive, bromellite confers high mechanical strength and very high thermal conductivity. In nuclear reactors, it is used as a moderator for fast neutrons. Ceramics containing bromellite are used in electronics, as well as crucibles for the melting of uranium and thorium. Bromellite, both natural and synthetic, is also used as a gemstone or as a collector's mineral. As a gemstone bromellite is extremely rare. To date there has been found only one crystal that is large enough to be cut. In 2000 Dunil Palitha Gunasekara of Ratnapura, Sri Lanka purchased a rough colorless 17.77-ct crystal from Ratnapura. He cut it into 15 pieces, of which 3 pieces with 2.80, 1.92 and 0.68 ct were sent to the GIA laboratory for further testing, since he thought them to be johachidolite at first. These gemstones are the first reported examples of faceted gem-quality bromellite.

References

R.V. Gaines et al., Dana's New Mineralogy, 8th edition, John Wiley & Sons, NY, 1997, p 211.
SFM and Sam Muhlmeister, Gems & Gemology, Volume 38, No 3, Fall 2002, pp 250–251.
WebMineral Listing
MinDat Listing
Dictionary of Mining, Mineral, and Related Terms
Gemmologist Murray Burford

Beryllium minerals
Oxide minerals
Hexagonal minerals
Minerals in space group 186
Image-based modeling and rendering. In computer graphics and computer vision, image-based modeling and rendering (IBMR) methods rely on a set of two-dimensional images of a scene to generate a three-dimensional model and then render some novel views of this scene.

The traditional approach of computer graphics has been used to create a geometric model in 3D and try to reproject it onto a two-dimensional image.  Computer vision, conversely, is mostly focused on detecting, grouping, and extracting features (edges, faces, etc.) present in a given picture and then trying to interpret them as three-dimensional clues.  Image-based modeling and rendering allows the use of multiple two-dimensional images in order to generate directly novel two-dimensional images, skipping the manual modeling stage.

Light modeling 
Instead of considering only the physical model of a solid, IBMR methods usually focus more on light modeling.  The fundamental concept behind IBMR is the plenoptic illumination function which is a parametrisation of the light field. The plenoptic function describes the light rays contained in a given volume. It can be represented with seven dimensions: a ray is defined by its position , its orientation , its wavelength  and its time : .  IBMR methods try to approximate the plenoptic function to render a novel set of two-dimensional images from another.  Given the high dimensionality of this function, practical methods place constraints on the parameters in order to reduce this number (typically to 2 to 4).

IBMR methods and algorithms
View morphing generates a transition between images
Panoramic imaging renders panoramas using image mosaics of individual still images
Lumigraph relies on a dense sampling of a scene
Space carving generates a 3D model based on a photo-consistency check

See also 
 View synthesis
 3D reconstruction
 Structure from motion

References

External links
 Quan, Long. Image-based modeling. Springer Science & Business Media, 2010. 
 
 
 
 

Computer graphics
Applications of computer vision
3D imaging
Trapp mixture. The Trapp mixture is a specific mixture of organic solvents that allows chemical reactions to take place at very low temperatures.  It is made up of THF:diethyl ether:pentane in a 4:4:1 ratio which remains liquid down to −110 °C and the same solvents in a 4:1:1 ratio remain a liquid down to −120 °C. This solvent system retains a low viscosity until just before freezing and it allows a lower temperature reaction than pure THF, which melts at −108.4 °C.  An illustrative application of Trapp solvent is the preparation of vinyllithium by lithium halogen exchange from vinyl bromide and tert-butyllithium.  The low temperatures suppress the reaction of the strongly basic organolithium reagent with the THF.

References 

Solvents
HP Brio. The HP Brio was a line of business-oriented desktop personal computers made by Hewlett-Packard aimed at small businesses.

The 7000 series was targeted at mainstream business computing, and started with a street price of $2449, inclusive of a 15-inch monitor. The 8000 was designed for "power-hungry" business users. Both series were announced in September 1998.

In June 1999, HP announced Brio models BA and BAx that included Microsoft Office 2000 Small Business. They were launched at street prices of $999 and $1,499 respectively.

Announced in October 1999 at an estimated street price of $499, the BA200 was aimed at small businesses that purchase white box PCs—non-branded PCs assembled by resellers or consumer PCs from manufacturers such as eMachines at retail. The PCs came ready for Windows 2000, and were certified for Novell network operating systems, for easy integration into a networked environment. They also shipped with HP Brio Internet Center and HP Brio Center, which together provided comprehensive Internet and e-commerce capabilities and online support.

Alongside HP's announcement of a new HP Brio Business PC line with the HP Brio Internet Center, HP also announced an agreement with AT&T; WorldNet Service to provide small- and medium-business customers with fast, easy access to the Internet. The alliance with AT&T was meant to provide small and medium businesses with an end-to-end solution—from initial connection to creating a Web site and online store.

In 1998, HP partnered with Symantec to incorporate pcANYWHERE32, a remote-control software package, on all HP Brio PCs for small and medium companies without an information technology (IT) staff.

Geared for small business users, the value lines of Brio PCs offered on-screen and online tech support. The latter came via a customized Yahoo! web site that featured news, business tips, stock reports, and product-specific service and support content from HP.

In May 2000, the HP Brio BA200 placed sixth on PC World's May list of Top 10 Budget PCs.

In January 2002, Netscape Communications announced that it had licensed its Netcenter Web portal to Hewlett-Packard for the Brio line of business computers.

Models
The following is a list of all HP Brio models ever launched. "x" in the following names is a variable for models 71-85.

HP Brio 71xx
HP Brio 80xx
HP Brio 81xx
HP Brio 82xx
HP Brio 83xx
HP Brio 84xx
HP Brio 85xx
HP Brio BA200
HP Brio BA210
HP Brio BA400
HP Brio BA410
HP Brio BA600
HP Brio BAx
HP Brio BA
HP Brio BA300

References

Brio
Specman. Specman is an EDA tool that provides advanced automated functional verification of hardware designs. It provides an environment for working with, compiling, and debugging testbench environments written in the e Hardware Verification Language.  Specman also offers automated testbench generation to boost productivity in the context of block, chip, and system verification.

The Specman tool itself does not include an HDL simulator (for design languages such as VHDL or Verilog.)  To simulate an e-testbench with a design written in VHDL/Verilog, Specman must be run in conjunction with a separate HDL simulation tool. Specman is a feature of Cadence's new Xcelium simulator, where tighter product integration offers both faster runtime performance and debugs capabilities not available with other HDL simulators. In principle, Specman can co-simulate with any HDL simulator supporting standard PLI or VHPI interface, such as Synopsys's VCS, or Mentor's Questa.

History 
Specman was originally developed at Verisity, an Israel-based company, which was acquired by Cadence on April 7, 2005.

It is now part of Cadence's functional verification suite.

References

Hardware verification languages
Steam tank. The Steam tank (tracked) was an early U.S. tank design of 1918 imitating the design of the British Mark IV tank but powered by steam.

The type was designed by an officer from the U.S. Army's Corps Of Engineers. The project was started by General John A. Johnson with the help of the Endicott and Johnson Shoe Company and financed by the Boston bankers Phelan and Ratchesky, costing $60,000 (US$  in ). Expertise was called in from Stanley Motor Carriage Company in Watertown, Massachusetts, that produced steam cars. The engines and boilers of two Unit Railway Cars were built in. Earlier fighting vehicles projects had employed steam power because petrol engines were not yet powerful enough; the Steam tank however used it for the main reason that it was meant to be a specialized flame tank to attack pillboxes and the original design had this weapon driven by steam. When the main device to build up sufficient pressure became a  auxiliary gasoline engine, the two main 2-cylinder steam engines with a combined power of  remained, each engine driving one track to give a maximum speed of . The transmission allowed two speeds forward and two in reverse. The steam engines used kerosene for fuel.

The flamethrower, located in the front cabin, had a range of ; additionally there were four .30 cal. (7.62 mm) machine guns; two in a sponson at each side. The length of the vehicle was , the width  and the height . The tracks were  wide. Each track frame carried mud clearing spikes, sometimes mistaken for battering rams. The tank had a weight of about . There was to have been a crew of eight, on the assumption there were a commander, a driver, an operator of the flame thrower, a mechanic and four machine gunners.

Only one was completed in Boston and demonstrated in April 1918, in several parades also, on one occasion breaking down in front of the public. The prototype was in June shipped to France to be tested — with much publicity to bolster allied morale — and was named America. The flame thrower nozzle was moved to a rotating turret on the roof of the cabin.

There was a contemporary steam-powered armored vehicle - the Steam Wheel Tank - which was not tracked but an armored three-wheeled vehicle, hence the designation "(Tracked)" or "(Track-laying)". The design combined serious cooling problems with a dangerous vulnerability due to its two steam boilers and large fuel reservoirs needed to heat the two main engines, and feed both the auxiliary engine and the flame thrower.

Bibliography 
Notes

References 

World War I tanks
Tanks of the United States
Abandoned military projects of the United States
Tank
Trial and research tanks of the United States
History of the tank
Swain equation. The Swain equation relates the kinetic isotope effect for the protium/tritium combination with that of the protium/deuterium combination according to:

where kH,D,T are the reaction rate constants for the protonated, deuterated and tritiated reactants respectively.

External links 
 Applied Swain equation

References 
 Use of Hydrogen Isotope Effects to Identify the Attacking Nucleophile in the Enolization of Ketones Catalyzed by Acetic Acid C. Gardner Swain, Edward C. Stivers, Joseph F. Reuwer, Jr. Lawrence J. Schaad; J. Am. Chem. Soc.; 1958; 80(21); 5885-5893. 

Chemical kinetics
Equations
Flannelgraph. Flannelgraph (also called flannel board or flannelgram) is a storytelling system that uses a board covered with flannel fabric, usually resting on an easel. It is very similar to Fuzzy Felt, although its primary use is as a storytelling medium, rather than as a toy.

Description of use

The flannel board is usually painted to depict a background scene appropriate to the story being told.   Paper cutouts of characters and objects in the story are then placed on the board, and moved around, as the story unfolds.  These cutouts are backed, either with flannel, or with some other substance that adheres lightly to the flannel background, such as coarse sandpaper.

Plain, undecorated flannel boards can also be used as a visual aid during presentations, allowing the speaker to display and remove charts and graphs as needed.

Associations with Christianity

In the United States, flannelgraph has been (and continues to be) a popular medium for telling Bible stories to young Sunday School students in Christian (and particularly Evangelical) churches.  Indeed, in the United States it is used as a storytelling method almost exclusively in elementary-level Christian education.   This may be attributed, in part, to the fact that flannelgraph is relatively inexpensive, yet provides a more vivid alternative to storytelling without visual illustration.  Most people use pre-published pictures and lessons, such as from Betty Lukens or Child Evangelism Fellowship, and some add on their own materials for introduction or application, as in the "Illustrating Application" (Florence Hunnicutt) videos on YouTube.

See also
 Child Evangelism Fellowship
 Fuzzy felt
 Bible story

Notes

Books

Visual arts media
Storytelling
Christian performing arts
Early childhood education materials
Okmetic. Okmetic is a Chinese-owned company in Finland that supplies tailored, high value-added silicon wafers to be used in the manufacture of sensors as well as discrete semiconductors and analog circuits. Okmetic has a global customer base and sales network based in Finland, the United States, Japan, China and Hong Kong. In addition, the company has sales agents in China, Korea, Malaysia, Singapore, Taiwan and the United States. The company's headquarters is located in Finland, where the majority of the company's silicon wafers are manufactured.  The company also has contract manufacturing in Japan and China.

Okmetic was listed on Nasdaq Helsinki Ltd under the trading code OKM1V before it was acquired in 2016 by China's National Silicon Industry Group (NSIG).

References

Electronics companies of Finland
Silicon wafer producers
Technology companies of Finland
Electronics companies established in 1985
Technology companies established in 1985
1985 establishments in Finland
Vantaa
Companies formerly listed on Nasdaq Helsinki
Ethyl acetoacetate. The organic compound ethyl acetoacetate (EAA) is the ethyl ester of acetoacetic acid. It is a colorless liquid. It is widely used as a chemical intermediate in the production of a wide variety of compounds.

Preparation
At large scale, ethyl acetoacetate is industrially produced by treatment of diketene with ethanol.

The small scale preparation of ethyl acetoacetate is a classic laboratory procedure. It involves Claisen condensation of ethyl acetate. Two moles of ethyl acetate condense to form one mole each of ethyl acetoacetate and ethanol.

Reactions
Ethyl acetoacetate is subject to keto-enol tautomerism. In the neat liquid at 33 °C, the enol consists of 15% of the total.  

The enol is moderately acidic.  Thus ethyl acetoacetate behaves similarly to acetylacetone:

The resulting carbanion undergoes nucleophilic substitution. Ethyl acetoacetate is often used in the acetoacetic ester synthesis, comparable to diethyl malonate in the malonic ester synthesis or the Knoevenagel condensation. After its alkylation and saponification, thermal decarboxylation is also possible.  

The dianion of ethyl acetoacetate is also a useful building block, except that the electrophile adds to the terminal carbon.  The strategy can be depicted in the following simplified form:
 (Bu = butyl)

Reduction of ethyl acetoacetate gives ethyl 3-hydroxybutyrate.

Ethyl acetoacetate transesterifies to give benzyl acetoacetate via a mechanism involving acetylketene. Ethyl (and other) acetoacetates nitrosate readily with equimolar sodium nitrite in acetic acid, to afford the corresponding oximinoacetoacetate esters. A dissolving-zinc reduction of these in acetic acid in the presence of ketoesters or beta-diketones constitute the Knorr pyrrole synthesis, useful for the preparation of porphyrins.

Another similarity to acetylacetone, ethyl acetoacetate forms chelate complexes, such as  and the Fe(III) derivative.

See also
Two ketals of ethyl acetoacetate are used in commercial fragrances.
 Fructone (), the ethylene glycol ketal
 Fraistone (), the propylene glycol ketal

Safety and environmental considerations
Ethyl acetoacetate has low toxicity to animals.  It is highly biodegradable.

References

External links
International Chemical Safety Card 1024
Inchem properties database

Ethyl esters
Ester solvents
Flavors
Acetoacetate esters
Sweet-smelling chemicals