omniomni/omni-engineering huggingface dataset:
Bevel. A bevelled edge (UK) or beveled edge (US) is an edge of a structure that is not perpendicular to the faces of the piece. The words bevel and chamfer overlap in usage; in general usage, they are often interchanged, while in technical usage, they may be differentiated as shown in the image on the right. A bevel is typically used to soften the edge of a piece for the sake of safety, wear resistance, aesthetics; or to facilitate mating with another piece.

Applications

Cutting tools
Most cutting tools have a bevelled edge which is apparent when one examines the grind.

Bevel angles can be duplicated using a sliding T bevel.

Graphic design

Typographic bevels are shading and artificial shadows that emulate the appearance of a 3-dimensional letter. The bevel is a relatively common effect in graphic editors such as Photoshop. As such, it is in widespread use in mainstream logos and other design elements.

Glass and mirrors
Bevelled edges are a common aesthetic nicety added to window panes and mirrors.

Geology
Geologists refer to any slope of land into a stratum of different elevation as a bevel.

Sports
In waterskiing, a bevel is the transition area between the side of the ski and the bottom of the ski. Beginners tend to prefer sharp bevels, which allow the ski to glide on the water surface.

In Disc Golf, the 'beveled edge' was patented in 1983 by Dave Dunipace who founded Innova Champion Discs. This element transformed the Frisbee into the further-flying golf discs the sport uses today.

Cards
With a deck of cards, the top portion can be slid back so that the back of the deck is at an angle, a technique used in card tricks.

Semiconductor wafers
In the semiconductor industry, wafers have two typical edge types: a slanted beveled shape or a rounded bullet shape. The edges on the beveled types are called the bevel region, and they are typically ground at a 22-degree angle. While it is not possible to create a complete and functional die with the bevel material of a wafer, the area is still routinely processed throughout the manufacturing cycle to remove unwanted masks, residues, and films from the edge of a wafer that could potentially become a source of defects between manufacturing steps.

Welding
Beveling and chamfering (along with other profiles) are applied to thicker pieces of metal prior to welding, see Welding joint#V-joints. The bevel provides a smooth clean edge to the plate or pipe and allows a weld of the correct shape (to prevent center-line cracking) to join the separate pieces of metal.

Simple bevels can be used with a backup strip (thin removable sheet behind the plate joint) with chamfers (and a small land) being used on open root welds. Particularly thick plate will have a J-shaped chamfer or U-shaped groove to reduce the amount of welding filler metal used.

Cruciform joint preparation can involve a double bevel to permit full penetration of each weld to the other, removing a possible void space in the center.

References

External links

Choosing and Using Squares – This Old House

Angle
Woodworking
Tadelakt. Tadelakt () is a waterproof plaster surface used in Moroccan architecture to make baths, sinks, water vessels, interior and exterior walls, ceilings, roofs, and floors. It is made from lime plaster, which is rammed, polished, and treated with soap to make it waterproof and water-repellent. Tadelakt is labour-intensive to install, but durable. Since it is applied as a paste, tadelakt has a soft, undulating character, it can form curves, and it is seamless. Pigment can be added to give it any colour, but deep red is traditional. It may have a shiny or matte finish.

Etymology and history
The term tadelakt, meaning "to rub in", is an Amazighified expression from the Arabic word  , meaning "to rub or massage."

Tadelakt is thought to have evolved from qadad, a similar plaster used in Yemen for millennia that is treated with calcium hydroxide and oils and fats instead of soaps.

Constituents and chemistry
The basic constituents of tadelakt plaster are:
 lime plaster (not Portland cement)
 in some cases, marble or limestone sand (but not other aggregates)
 natural soap (often "black" or olive oil soap) to speed carbonation of the surface and impart water-resistance.  

The soap chemically reacts with the lime plaster, forming lime (calcium) soaps. Calcium soaps are insoluble in water, and fairly hard. They are familiar, in areas with calcium-rich ("hard") water, as deposits in bathtubs, sinks, and showers; when soap is mixed with the water's dissolved calcium carbonate/lime, calcium soaps form.

2 C17H35COO−Na+ + Ca2+   →  (C17H35COO)2Ca  + 2 Na+

Techniques

Traditional application includes polishing with a river stone and treatment with oleic acid, in the form of olive oil soap, to lend it its final appearance and water resistance.

In Morocco, the traditional application technique:
 plaster powder is mixed with water for 12 to 15 hours prior to the addition of pigment.
 the plaster is applied in one thick coat with a wooden float, and smoothed with the same. 
 before the plaster sets, a flat, smooth, hard stone is used to compress the plaster, then a plastic trowel used for the final polish.
 it is mechanically polished using stones or abrasives harder than the plaster, providing a smooth, sometimes shiny, finish.
 lastly, an olive-oil soap solution is used to seal the plaster

Long-term maintenance of tadelakt requires regularly re-sealing the surface with a soap solution; in the case of qadad roofs, this was traditionally done every few years.

Uses

Tadelakt is the traditional coating of the hammams and bathrooms of palaces and riad residences in Morocco. The restoration of riads in Morocco has led to a resurgence in its use.

In modern times, it has been used outside.

See also

References

External links
 

Culture of Morocco
Moroccan handicrafts
Architecture in Morocco
Moorish architecture
Islamic architectural elements
Building materials
Interior design
Wallcoverings
Plastering
Arab inventions
Moisture protection
Deductive database. A deductive database is a database system that can make deductions (i.e. conclude additional facts) based on rules and facts stored in its database. Datalog is the language typically used to specify facts, rules and queries in deductive databases. Deductive databases have grown out of the desire to combine logic programming with relational databases to construct systems that support a powerful formalism and are still fast and able to deal with very large datasets. Deductive databases are more expressive than relational databases but less expressive than logic programming systems such as Prolog. In recent years, deductive databases have found new application in data integration, information extraction, networking, program analysis, security, and cloud computing.

Deductive databases reuse many concepts from logic programming; rules and facts specified in Datalog look very similar to those written in Prolog, but there are some important differences: 
 Order sensitivity and procedurality: In Prolog, program execution depends on the order of rules in the program and on the order of parts of rules; these properties are used by programmers to build efficient programs. In database languages (like SQL or Datalog), however, program execution is independent of the order of rules and facts.
 Special predicates: In Prolog, programmers can directly influence the procedural evaluation of the program with special predicates such as the cut. This has no correspondence in deductive databases.
 Function symbols: Logic programming languages allow function symbols to build up complex symbols. This is not allowed in deductive databases.
 Tuple-oriented processing: Deductive databases use set-oriented processing, while logic programming languages concentrate on one tuple at a time.

References

Further reading 
 Author: Herve Gallaire, Jack Minker, Jean-Marie Nicolas: Logic and Databases: A Deductive Approach. Publisher: ACM. doi:10.1145/356924.356929
 Author: Stefano Ceri, Georg Gottlob, Letizia Tanca: Logic Programming and Databases. Publisher: Springer-Verlag. 
 Author: Ramez Elmasri and Shamkant Navathe: Fundamentals of Database Systems (3rd edition). Publisher: Addison-Wesley Longman. 

Database management systems
IBM TouchMobile. The IBM TouchMobile is a robust and practical hand-held computer announced by IBM in 1993.  This device has a bar code scanner with on-screen signature and data capture.  Certain models are capable of wireless communication.

The hand-held computer used a version of embedded DOS.  The processor was an 80C88 processor.  The system design also used 1.5 MB of PSRAM (Pseudostatic DRAM) and two custom chips.

References
 

TouchMobile
Electronic organizer. An electronic organizer (or electric organizer) is a small calculator-sized computer, often with an built-in diary application and other functions such as an address book and calendar, replacing paper-based personal organizers. Typically, it has a small alphanumeric keypad and an LCD screen of one, two, or three lines.

They were very popular especially with businessmen during the 1990s, but because of the advent of personal digital assistants and palmtop PCs in the 1990s, as well as smartphones in the 2010s, all of which have a larger set of features, electronic organizers are mostly seen today for research purposes. One of the leading research topics being the study of how electronics can help people with mental disabilities use this type of equipment to aid their daily life.  Electronic organizers have more recently been used to support people with Alzheimer's disease to have a visual representation of a schedule.

History
The electronic diary or organizer was first patented by Indian businessman Satyanarayan Pitroda in 1975.

Casio digital diary
Casio digital diaries were produced by Casio in the early and mid 1990s, but have since been entirely superseded by mobile phones and PDAs.

Other electronic organizers 
While Casio was a major role player in the field of electronic organizers there were many different ideas, patent requests, and manufacturers of electronic organizers. Rolodex, widely known for their index card holders in the 1980s, Sharp Electronics, mostly known for their printers and audio visual equipment, and lastly Royal electronics were all large contributors to the electronic organizer in its heyday.

Features
 Telephone directory
 Schedule keeper: Keep track of appointments.
 Memo function: Store text data such as price lists, airplane schedules, and more.
 To do list: Keep track of daily tasks, checking off items as you complete them.
 World time: Find out the current time in virtually any location on the globe.
 Secret memory area: The secret memory area keeps personal data private. Once a password is registered, data is locked away until the password is used to access the secret area.
 Alarm
 Metric conversion function: Conversion between metric units and another measurement unit.
 Currency conversion function
 Game: Some machines included a game such as Poker or Blackjack.

See also
 Pocket electronic dictionary
 Personal digital assistant (PDA)
 Smartphone
 Pocket computer

References

External links

Mobile computers
STS Mir. STS Mir () is a three-masted, full-rigged training ship, based in St. Petersburg, Russia. It was built in 1987 at the Lenin Shipyard in Gdańsk, Poland. 

Mir is the second largest of six sister ships designed by Polish naval architect Zygmunt Choreń and weighs 2,385 tonnes.  It is 109.2 m long, with a beam of 13.9 m and a draught of 6.3 m.  The main mast is 52 m high and along with the other masts supports a total sail area of 2,771 m2.

Its sister ships are Dar Młodzieży, Druzhba, Pallada, Khersones, and Nadezhda.  Mir is 8 m shorter than the second longest current sailing ship, the STS Sedov (117.5 m). Its shipowner is the Admiral Makarov State Maritime Academy (AMSMA) in Saint Petersburg.

Background
This ship was originally constructed as a cadet training ship, designed for carrying between 70 and 144 cadets. The total transport capacity is 199 people.

Achievements
Mir has taken part in races, including the annual The Tall Ships' Races organised by Sail Training International. In the Grand Regatta Columbus 1992, celebrating the discovery of America by Christopher Columbus in 1492, Mir came out as the winner.

STS Mir at Trafalgar 2005  

During the afternoon of the 28 June 2005 Elizabeth II, as Lord High Admiral of the United Kingdom, embarked on board HMS Endurance and, escorted by THV Patricia, set sail to review a fleet of over 167 ships from over 30 nations.

See also
List of large sailing vessels

External links

Official website of STS MIR

Mir
Ships of the Soviet Union
Poland–Soviet Union relations
Full-rigged ships
Ships built in Gdańsk
ENM. ENM may refer to:

 École nationale de la météorologie, a renowned French graduate engineering school specializing in meteorology
 Emmonak Airport (FAA LID: ENM), a state-owned public-use airport located in Emmonak, Alaska
 Escuela Naval Militar, a coeducational Naval Academy that educates officers for commissioning 
 French National School for the Judiciary (École nationale de la magistrature), a French post-graduate school
 Middle English (ISO 639-2 & -3: enm), a form of the English language spoken after the Norman conquest until the late 15th century
 Species distribution modelling (also environmental niche modelling), the use of computer algorithms to predict the distribution of a species across geographic space and time
 United National Movement (Georgia) (Ertiani Natsionaluri Modzraoba), a political party in Georgia
 Ethical non-monogamy, also known as consensual non-monogamy, a style of intimate or sexual relationship
John Hunter (scientist). John Hunter (born November 14, 1955) is an American projectile researcher, who developed the 1994 "supergun" Super High Altitude Research Project (SHARP) at the Lawrence Livermore National Laboratory. The ultimate aim of his research is to shoot payloads into space, at less than one tenth of the cost of unmanned rockets. John Hunter was the director of Quicklaunch until 2012 and currently runs a startup called Green Launch that is developing a light-gas gun concept

See also 

 Gerald Bull
 Non-rocket spacelaunch

References

External links 
New technology testing may achieve the goals of HARP "space" gun
Video Interview of John Hunter - Gas Station In Space  moonandback 2011
Audio Interview of John Hunter on The space show
Interview of John Hunter on medium.com

21st-century American engineers
1955 births
Living people
Roborior. Roborior is a robot manufactured by the robotics company Tmsuk and marketed by Sanyo. It is used both for lighting and guarding homes. Roborior is roughly the size of a watermelon and can produce different hues of color ranging from blue, purple, and orange. The Roborior is also equipped with a digital video camera that can stream live video directly to the owner's cell phone if it detects an intruder. The Roborior can be controlled remotely with a hand set, much like a Remote control vehicle, as well. It was introduced in Japan in late 2005 and was priced at 280,000 Japanese yen. The name is a portmanteau of robot and interior.

References

External links
 Description of the Roborior 

Domestic robots
Robots of Japan
2005 robots
2,2,4-Trimethylpentane. 2,2,4-Trimethylpentane, also known as isooctane or iso-octane, is an organic compound with the formula (CH3)3CCH2CH(CH3)2. It is one of several isomers of octane (C8H18). This particular isomer is the standard 100 point on the octane rating scale (the zero point is n-heptane). It is an important component of gasoline, frequently used in relatively large proportions (around 10%) to increase the knock resistance of fuel.

Strictly speaking, if the standard meaning of ‘iso’ is followed, the name isooctane should be reserved for the isomer 2-methylheptane. However, 2,2,4-trimethylpentane is by far the most important isomer of octane and historically it has been assigned this name.

Production
Isooctane is produced on a massive scale in the petroleum industry by alkylation of isobutene with isobutane. This process is conducted in alkylation units in the presence of acid catalysts.

It can also be produced from isobutylene by dimerization using an Amberlyst catalyst to produce a mixture of iso-octenes.  Hydrogenation of this mixture produces  2,2,4-trimethylpentane.

History
Engine knocking is an unwanted process that can occur during high compression ratios in internal combustion engines. In 1926 Graham Edgar added different amounts of n-heptane and 2,2,4-trimethylpentane to gasoline, and discovered that the knocking stopped when 2,2,4-trimethylpentane was added. This work was the origin of the octane rating scale. Test motors using 2,2,4-trimethylpentane gave a certain performance that was standardized as 100 octane.  The same test motors, run in the same fashion, using heptane, gave a performance which was standardized as 0 octane.  All other compounds and blends of compounds then were graded against these two standards and assigned octane numbers.

Safety
In common with all hydrocarbons, 2,2,4-trimethylpentane is flammable.

See also
 Oil refinery
 Antiknock agents

References

External links

International Chemical Safety Card 0496

Alkanes
Antiknock agents
F84. F84 or F-84 may refer to;

 F-84 Thunderjet, an early American straight-wing jet fighter
 F-84F Thunderstreak, a swept-wing development of the Thunderjet
 XF-84H Thunderscreech, a turboprop variant of the Thunderstreak
 HMS Exmouth, a Blackwood class frigate
 the ICD-11 medical code for Pervasive developmental disorders
F80. F80 may refer to:

Vehicles 
Aircraft
 Farman F.80, a French biplane
 Lockheed F-80 Shooting Star, an American jet fighter
 UL-Jih F80 Fascination, a Czech ultralight

Automobiles
 BMW F80, a German high performance sedan
 Toyota Kijang (F80), a Japanese multi purpose vehicle
 Ferrari F80, limited production sports car built by Italian automotive manufacturer Ferrari

Ships
 , a Blackwood-class frigate of the Royal Navy
  a Type 23 frigate of the Royal Navy
 , an R-class destroyer of the Royal Navy
 , a destroyer tender of the Royal Navy

Other uses 
 Nikon F80, a SLR camera also known as the Nikon N80
Gas heater. A gas heater is a space heater used to heat a room or outdoor area by burning natural gas, liquefied petroleum gas, propane, or butane.

Indoor household gas heaters can be broadly categorized in one of two ways: flued or non-flued, or vented and unvented.

History 
The first gas heater made use of the same principles as the Bunsen burner. Beginning in 1881, the burner's flame was used to heat a structure made of asbestos, a design patented by Alice H.Parker, a England engineer.

Function 
The gas heater is able to warm up a whole room by first allowing the flame to heat the air locally, then it disperses throughout the air by convection. Today the same principle applies with outdoor patio heaters or "mushroom heaters" which act as giant Bunsen burners.

Modern gas heaters have been further developed to include units that utilize radiant heat technology, rather than the principles of the Bunsen burner. This form of technology does not spread via convection, but rather, is absorbed by people and objects in its path. This form of heating is useful for outdoor heating, where it is more economical than using a standard air heating system.

Flued heaters

Flued heaters are permanently installed wherever they are placed. The flue, if properly installed with the correct overall height, size, and orientation should extract all of the heater emissions. A correctly operating flued gas heater is typically safe for use.

Non-flued heaters

Non-flued heaters – also known as unvented heaters, vent-free heaters, or flueless fires, may be either permanently installed or portable, and sometimes incorporate a catalytic converter. Non-flued heaters can be risky if appropriate safety procedures are not followed. There must be adequate ventilation, they must be kept clean, and they should always be switched off before sleeping. If operating correctly, the main emissions of a non-flued gas heater are water vapour, carbon dioxide, and nitrogen dioxide.

Operation
Home gas heating controls cycle using a mechanical or electronic thermostat.  Gas flow is actuated with a valve. Ignition is by an electric filament or pilot light. Flames heat a radiator in the air duct but outside the flue, convection or a fan may distribute the heat.

See also 
 Gasoline heater
 Kerosene heater
 Fireplace

References

External links

Burners
Heaters
Heater

ja:ガスストーブ
Slipstream (disambiguation). A slipstream is a pocket of reduced pressure following behind an object moving through a fluid medium.

Slipstream may also refer to:

People
 Zammis Clark, referred to as Slipstream

Computing
 Slipstream (computer science), the technique of running a shortened program concurrently and ahead of the execution of the full program
 Slipstream (computing), a slang term for merging patches or updates into the original installation sources of a program
 Slipstream 5000, a 1995 racing game for PC

Fiction
 Slipstream fiction, a literary genre that pushes the boundary between traditional fiction and either science fiction and/or fantasy
 Slipstream (radio drama), a BBC Radio 7 science fiction series
 Slipstream (science fiction), fictional methods of faster-than-light travel

Characters
 Slipstream (comics), a Marvel Comics superhero character
 Slipstream (Transformers), several robot characters in the Transformers franchise including Transformers: Animated
 Slip Stream (G.I. Joe), a pilot character in the G.I. Joe franchise

Film
 Slipstream (unfinished film), an unfinished Steven Spielberg movie
 Slipstream (1973 film), a Canadian drama directed by David Acomba
 Slipstream (video), a 1980 concert by Jethro Tull
 Slipstream (1989 film), a post-apocalyptic adventure directed by Steven Lisberger
 Slipstream (2005 film), a time travel thriller directed by David van Eyssen
 Slipstream (2007 film), a drama written and directed by Anthony Hopkins

Music
 Slipstream (band), a UK indie band

Albums
 Slipstream (Bonnie Raitt album), 2012
 Slipstream (Sherbet album) or the title song (see below), 1974
 Slipstream (Sutherland Brothers and Quiver album) or the title song, 1976

Songs
 "Slipstream" (song), by Sherbet, 1974
 "Slipstream", by Killing Joke from Extremities, Dirt and Various Repressed Emotions, 1990
 "Slipstream", by Jethro Tull from Aqualung, 1971
 "Slipstream", by Mike Oldfield from Light + Shade, 2005
 "Slipstream", by Threshold from Dead Reckoning, 2007

Others
 Slipstream (arcade game), a 1995 racing game by Capcom
 Slipstream (magazine), a literary press and magazine founded in 1980
 Slipstream (sculpture), a sculpture created by Richard Wilson
 Drafting (aerodynamics), also called slipstreaming
 Team Slipstream, a UCI professional cycling team