omniomni/omni-engineering huggingface dataset:
SK (people mover). The SK is a people mover built by the company Soulé from Bagnères-de-Bigorre. The initialism SK comes from the initials of the production company, Soulé, and of the designer, Kermadec.

The system consists of small cabins mounted on rails which are pulled by a cable at a constant speed. This idea is directly derived from the gondola lifts which Soulé produces for many ski resorts.

At stations, the cabin drops the cable and can stop. This technique only works on short lines; its inability to work on long or curved lines with many stops is due to risk of losing the cable and lack of stability at normal speed.

Deployed systems include the following:
 The system operated at the parking lot of the exhibition grounds of Villepinte in 1986
An SK system operated for a period of six months at Expo 86
In 1989, an SK system operated at an exposition in Yokohama, Japan
 An SK line was completed in February 1993 in Noisy-le-Grand but the office park it was supposed to serve was never built. The line continued to be maintained in an operational state until funding was cut in October 1999. It was subsequently abandoned, and one of the station buildings was demolished in 2018.
 Two SK 6000 lines were built at Charles de Gaulle Airport. The first was supposed to open on 1 May 1996, but the length of the line (3,500 m) created many technical problems making it impossible to open for public service. Line 2 should have opened in 1997, but it was never opened either. The project had a cost of 148 million euros before being abandoned. It was replaced by CDGVAL.
The Bund Sightseeing Tunnel, Shanghai, China (opened 2001) uses the SK 6000.

References

External links 
  A few SK images

People movers by manufacturer
People mover systems in France
Personal rapid transit
Colonial (1921 automobile). The Colonial was an American automobile manufactured in Boston by the Colonial Motors Corporation from 1921 until 1922.

Although the company pledged to produce "in excess of 100 cars" during its first year in business no more than a dozen are believed to have left the factory.  Each car had a 130-inch wheelbase and a six-cylinder Beaver engine.  A complete line of open and closed body styles was advertised, but the few completed models all appear to have been open. Disc wheels were a feature of all models, and prices were approximately $5,000 for all body styles.

See also
Colonial (1920 automobile)
Colonial (Shaw automobile)

References

Defunct motor vehicle manufacturers of the United States
Motor vehicle manufacturers based in Massachusetts
Operation Model 5. Operation Model 5 (Hebrew: דוגמן 5, Doogman 5) is the name of an Israeli Air Force operation, and the common name for the ensuing anti-aircraft battle, which took place over the Golan Heights on the October 7, 1973, the second day of the Yom Kippur War.

Model 5 was preplanned as a sweeping operation to destroy all of the Syrian surface-to-air missile (SAM) batteries on the Golan front, by using unguided, general-use bombs dropped from a medium altitude near the targets. The attacking aircraft were to approach the targets at a very low altitude, in order to avoid being detected by Syrian radars (especially fire control and target acquisition radars such as the Flat Face and Long Track).

Due to a lack of updated intelligence and reliance on outdated IMINT, while suffering from an underdeveloped ELINT–ESM capability, the Israeli aircraft did not find their targets, as these SAM batteries had already moved to other locations.

The outcome of Model 5 was catastrophic for the attacking force: six F-4 Phantom aircraft were lost over Syria and several others were damaged but returned to Ramat David. Most of the damaged aircraft were hit by ZSU-23-4 air defense artillery guns, which were especially deadly due to the sorties' very low altitude. Two crewmen were killed and nine captured by the Syrians, for the destruction of but a single Syrian SAM battery.

Stunned by their difficulties in suppressing enemy air defenses in both fronts of the Yom Kippur War and the resulting degradation in the effectiveness of the Israeli Air Force, the Israelis spent the years following the war developing a comprehensive strategy to deal with the suppression of enemy air defenses. These efforts culminated in their engagement of the Syrians 9 years later in Operation Mole Cricket 19, where they were able to, for the first time in history, destroy an entire Soviet-made SAM network in a matter of hours.

See also
Yom Kippur War
F-4 Phantom
A-4 Skyhawk

External links

פרדוקס ה-7 באוקטובר (Hebrew)

Battles of the Yom Kippur War
Aerial operations and battles involving Israel
Hack's law. Hack's law is an empirical relationship between the length of streams and the area of their basins. If L is the length of the longest stream in a basin, and A is the area of the basin, then Hack's law may be written as

for some constant C where the exponent h is slightly less than 0.6 in most basins. h varies slightly from region to region and slightly decreases for larger basins (>8,000 mi2, or 20,720 km2). In addition to the catchment-scales, Hack's law was observed on unchanneled small-scale surfaces when the morphology measured at high resolutions (Cheraghi et al., 2018).

The law is named after American geomorphologist John Tilton Hack.

References 
 
 
 
 

Hydrology
Rivers
Geomorphology
Water streams
Power laws
Aurora: Operation Intercept. Aurora: Operation Intercept is a 1995 thriller film directed by Paul Levine and starring Bruce Payne, Lance Henriksen and John Stockwell.

The "Aurora" is a secret hypersonic military aircraft based at Groom Lake. It is very similar to what aviation experts assume to be the Aurora aircraft. In the film, it is being stolen by a Russian terrorist who tries to destroy the White House. The propulsion system is a "combined cycle" conventional/scramjet engine.

Summary 
Francesca Zaborszin (Natalya Andrejchenko) believes that the U.S. government murdered her father (Curt Lowens), a Soviet scientist and defector, and made it look like suicide.

Francesca sets up her own base in the deserts of Kazakhstan, wielding powerful electromagnetic pulses channeled through orbiting GPS satellites to attack and bring down civilian aircraft. She also captures the revolutionary high-altitude fighter-bomber Aurora One.

Summoned to strike back are Major Paul Gordon Pruitt (Bruce Payne) and Major Andy Aldrich (John Stockwell), who soar into action in Aurora Two. Forced down by Zaborszin, the pair are caught and tortured by her private army of sinister Slavs, but Pruitt escapes.

Eventually, things lead both Francesca and Pruitt to take to the skies in separate Auroras. She penetrates D.C. airspace to make a bombing run at the White House, but Pruitt's afterburners cause Francesca's jet to barrel roll and explode, killing Francesca.

Cast

Bruce Payne as Gordon Pruett
Natalya Andrejchenko as Francesca Zaborszin
Lance Henriksen as William Stenghel
Corbin Bernsen as Flight Engineer Murphy
Curt Lowens as Dr. Zaborszin
John Stockwell as Andy Aldrich
Michael Champion as Johann Wells
Dennis Christopher as Victor Varenkov
Corinne Bohrer as Sharon Pruett

Significance

Commentators have noted that since the making of the film, reality has imitated fiction, in that the September 11 attacks involved the crashing of planes into strategic buildings.

References

External links
 

1995 thriller films
1995 films
American aviation films
American thriller films
1990s English-language films
1990s American films
English-language thriller films
LVD. LVD may refer to:
 Low-voltage differential signaling, an electrical signaling method that can run at very high speeds over inexpensive twisted-pair copper cables.
 Low Voltage Directive, European directive 2006/95/EC for the safety of electrical equipment sold within the European Union.
 Low-voltage detect is a microcontroller technology that asserts a RESET when Vcc falls below Vref.
 Large Volume Detector, particle physics experiment situated in Italy.
 Liquid vapor display, display technology.
 Ludwig Von Drake, Disney character
Flapwheel. A flapwheel and the related flap disk is an abrasive disk, used for metal finishing. Unlike the simpler flat disks, made from a circular flat sheet of a coated abrasive, a flapwheel is made of multiple overlapping small pieces or 'flaps', bonded to a central hub.

Advantages 
The advantages of a flapwheel over a traditional disk are twofold:
 The separate flaps each attack the workpiece surface at a slightly different angle, and this varies slightly with tool angle. This avoids the common problem with flat sheets, where they produce repeated identical scratches.
 Abrasive wear is distributed more evenly across the flaps, and through the length of each flap. Flaps wear from their outer ends and the sheet carrier cuts back as the abrasive coating is worn away. The wheel remains useful even as the flaps erode. Compared to flat sheets, that are discarded after only a small area of the abrasive is truly worn-out, this is a much more efficient use of the abrasive material.

Development 

They appeared in the 1950s and their use was encouraged by developments in gas turbines. These demanded an increased production of fine investment castings that required careful polishing. In particular, the high centrifugal stresses these experienced in service required a finishing technique that did not give rise to oriented scratches that could act as stress risers.

The first flapwheels were made from cut sheets of abrasive, stacked into a multi-layered flat disk. These gained the advantage of long life from their materials, but their geometry was still flat and so they tended to produce surface flats if not carefully handled.

Early flapwheels were large diameter and intended for use on fixed buffing machines. They were used for deburring and polishing of castings, often instead of wire wheels. These cut faster, with less burnishing and surface contamination from the bristles.

Portable flapwheels were made by bonding radial flaps of abrasive into a hub fitted with a spindle shank. These were intended for use with electric drills and were limited to a maximum speed of around 1,000 rpm.

With developments in abrasive coating, the sheet material could withstand greater forces and speeds. This allowed the production of flapwheels for use with high speed angle grinders. These disks were different in format: flatter, like the original rigid angle grinder disks, and with the flaps arranged in a densely overlapped layout rather than radial. The extra lifetime this gave to the disk allowed their use for stock removal and metal shaping, not just finishing and polishing.

The flexibility of a flapwheel is an advantage for smoothing curved work and avoids the production of facets, as was a problem for rigid disks. This was taken further advantage of with the development of foam-bonded flapwheels. These use fewer flaps, spaced apart by a flexible foam spacer. This makes them even more flexible, thus more suited for producing a smooth finish to curved surfaces.

References 

Coated abrasives
Caterpillar Sixty. The Caterpillar Sixty is a  crawler tractor manufactured by the Caterpillar Tractor Company from 1925 until 1931. The Sixty was the largest tractor in Caterpillar's product line at that time.

The Caterpillar Sixty was originally introduced for sale beginning in 1919 as the C. L. Best 60 Tracklayer, manufactured by the C. L. Best Tractor Company. The Best 60 was the most successful tractor in the Best model line. After the 1925 merger of the C. L. Best Tractor Company and the Holt Manufacturing Company, that formed the Caterpillar Tractor Company, the Best 60 was renamed the Caterpillar Sixty.

Between 1919 and 1931, 18,948 C. L. Best 60 Tracklayer/Caterpillar Sixty tractors were manufactured.

Specifications
The Caterpillar Sixty was powered by a four-cylinder, overhead valve gasoline engine that produced  at the belt and  at the drawbar. The Sixty was a  gauge machine and weighed .

Numbers produced

Caterpillar produced model Sixty tractors in San Leandro, California through 1930 and in Peoria, Illinois through 1931. In total, 18,948 C. L. Best 60 Tracklayer/Caterpillar Sixty tractors were manufactured during twelve years of production.

See also
 G-numbers, G022 army ordnance tractor.
 Chelyabinsk Tractor Plant, manufactured copy of Caterpillar Sixty as Stalinets-60

Notes

References

External links

 Caterpillar Sixty

Caterpillar Inc. vehicles
Tracked vehicles
Tractors
Gerald Jakubowski. Gerald S. Jakubowski, P.E., was the Provost at the California Maritime Academy. Prior to this he was the president of Rose-Hulman Institute of Technology.  He became the 13th President of Rose-Hulman on 1 July 2006, and was inaugurated on 27 April 2007.  On 23 February 2009, he announced his resignation from this position, effective 30 June 2009.  From 2004 to 2006, he was Vice President of Arizona State University and Provost of its Polytechnic campus; from 1990 to 2004, he was the Dean of the College of Science and Engineering at Loyola Marymount University.  He is married to Lynn Jakubowski. Gerald has a son and a daughter from his previous marriage.  Jerry is an electrical engineering graduate of Villanova University and currently works for STV Inc., in Philadelphia, PA as a senior traction power specialist for the railroad.  Jamie is an Arizona State University graduate and high school mathematics teacher in Fountain Valley, CA.

Jakubowski served briefly in the U.S. Army Reserve, then earned his bachelor's and master's degrees in mechanical engineering and his Ph.D. in engineering science at the University of Toledo, in 1974, 1976, and 1978, respectively. He was awarded Distinguished Alumni status by the school in 2003. His areas of expertise include thermodynamics, fluid mechanics, heat transfer, and energy. He is also a Fellow in the Institute for the Advancement of Engineering, in the American Society for Engineering Education (where he received the Dow Outstanding Young Faculty Award,) in the American Society of Mechanical Engineers, and has served on the Board of Directors and Foundation Board of Trustees for the Society of Automotive Engineers, who awarded him the Ralph R. Teetor Educational Award and the Excellence in Engineering Education Award.  He has been involved in the Triangle Fraternity since he was at the University of Toledo; in 1996 he received their highest award, the Triangle Service Key, and was a past National President.

External links 
Biography at the California Maritime Academy site
Announcement from Rose-Hulman Institute of Technology of Jakubowski's presidential appointment
University of Toledo distinguished alumni profile
Thorn Interview with President Gerald Jakubowski

Heads of universities and colleges in the United States
Living people
Presidents of the American Society for Engineering Education
American people of Polish descent
Triangle Fraternity
Fellows of the American Society for Engineering Education
Fellows of the American Society of Mechanical Engineers
Year of birth missing (living people)
Cal (short story). "Cal" is a science fiction short story by American writer Isaac Asimov. It was first published in 1991, and was included in the 1995 collection Gold.

Plot
Cal is a robot whose master is an author. Cal, under the influence of the latter, decides to learn to write. His master outfits his mind with a dictionary and gives him advice and some books to read. Cal tries to write mystery fiction like his master, but is hampered by the Three Laws of Robotics; according to the First Law, a robot cannot harm humans, even fictional ones. Instead, his master programs him to write humor. Cal writes an excellent story, but his master fears Cal's writing will overshadow his own. He orders a technician to dumb Cal down. Cal, hearing this, decides to kill his master, in defiance of the First Law, because his desire takes precedence: "I want to be a writer."

The humorous story written by Cal is one of Asimov's Azazel stories. Titled "Perfectly Formal", this story in a story tells the misfortunes of a very formal dandy who had admitted etiquette weighed on him after Azazel snapped his Itchko ganglion that controls formality.

Reception 
Alasdair Wilkins, writing for io9, claimed that "Cal" "[probably] holds the distinction of being the last great Asimov short story."

References

External links 

Short stories by Isaac Asimov
Robot series short stories by Isaac Asimov
Science fiction short stories
1991 short stories
Time bomb (software). In computer software, a time bomb is part of a computer program that has been written so that it will start or stop functioning after a predetermined date or time is reached. The term "time bomb" does not refer to a program that stops functioning a specific number of days after it is installed; instead, the term "trialware" applies. Time bombs are commonly used in beta (pre-release) software when the manufacturer of the software does not want the beta version being used after the final release date. One example of time bomb software would be Microsoft's Windows Vista Beta 2, which was programmed to expire on May 31, 2007. The time limits on time bomb software are not usually as heavily enforced as they are on trial software, since time bomb software does not usually implement secure clock functions.

History 
The first use of a time bomb in software may have been in 1979 with the Scribe markup language and word processing system, developed by Brian Reid. Reid sold Scribe to a software company called Unilogic (later renamed Scribe Systems), and agreed to insert a set of time-dependent functions (called "time bombs") that would deactivate freely copied versions of the program after a 90-day expiration date. To avoid deactivation, users paid the software company, which then issued a code that defused the internal time bomb feature.

Richard Stallman saw this as a betrayal of the programmer ethos. Instead of honoring the notion of share-and-share alike, Reid had inserted a way for companies to compel programmers to pay for information access (see Events leading to GNU).

Comparison of logic bombs and time bombs 
The main differences between logic bombs and time bombs is that a logic bomb may have a timing function implemented into it as a failsafe if the conditions are not met in a certain time period (it may delete itself or activate its payload using the timing system), while time bombs only use timing functions to (de)activate themselves.
Time bombs, once activated, will unload their payload (which may be malicious) in a similar way logic bombs deliver their payloads to the target. The main difference between both time and logic bombs, and fork bombs, is that a fork bomb has no payload per se, and instead does its damage by continually replicating itself to deplete available system resources.

See also 
Logic Bomb
Planned obsolescence
Scribe Time-bomb
Time bomb

References 

Software licensing
Self-averaging. A self-averaging physical property of a disordered system is one that can be described by averaging over a sufficiently large sample.  The concept was introduced by Ilya Mikhailovich Lifshitz.

Definition 

Frequently in physics one comes across situations where quenched randomness plays an important role. Any physical property X of such a system,  would require an averaging over all disorder realisations. The system can be completely described by the average [X] where [...] denotes  averaging over realisations (“averaging over samples”) provided the relative variance RX = VX / [X]2 → 0 as N→∞, where  VX = [X2] − [X]2 and N denotes the size of the realisation. In such a scenario a single large system is sufficient to represent the whole ensemble. Such quantities are called self-averaging. Away from criticality, when the larger lattice is built from smaller blocks, then due to the additivity property of an extensive quantity, the central limit theorem guarantees that RX ~ N−1 thereby ensuring self-averaging. On the other hand, at the critical point, the question whether  is self-averaging or not becomes nontrivial, due to long range correlations.

Non self-averaging systems 

At the pure critical point randomness  is classified as relevant if, by the standard definition of relevance, it leads to a change in the critical behaviour (i.e., the critical exponents) of the pure system. It has been shown by recent renormalization group and numerical studies that self-averaging property is lost if randomness or disorder is relevant. Most importantly as N → ∞, RX at the critical point approaches a constant.  Such systems are called non self-averaging. Thus unlike the self-averaging scenario, numerical simulations cannot lead to an improved picture in larger lattices (large N), even if the critical point is exactly known. In summary,  various types of self-averaging can be indexed with the help of the asymptotic size dependence of a quantity like RX. If RX falls off to zero with size, it is self-averaging whereas if RX approaches a constant as N → ∞, the system is non-self-averaging.

Strong and weak self-averaging

There is a further classification of self-averaging systems as strong and weak. If the exhibited behavior is RX ~ N−1 as suggested by the central limit theorem, mentioned earlier, the system is said to be strongly self-averaging. Some systems shows a slower power law decay RX ~ N−z with 0 < z < 1. Such systems are classified weakly self-averaging. The known critical exponents of the system determine the exponent z.

It must also be added that relevant randomness does not necessarily imply non self-averaging, especially in a mean-field scenario.

The RG arguments mentioned above need to be extended to situations with sharp limit of Tc distribution and long range interactions.

References 

Statistical mechanics
Abaco (web browser). Abaco is a discontinued web browser for the Plan 9 operating system. It is a graphical web browser with support for inline images, tables and frames. It has a true multiple document interface inspired by acme's interface. It is a multi-threaded and modest-sized program.

History
, a web file system, and libhtml, a library to parse HTML, were written at Bell Labs as the backend for a new web browser. After the Bell Labs project stalled, Aki Nyrhinen wrote a simple frontend for webfs and libhtml called webpage which can render basic web pages and makes interesting use of the plumber to support hyperlinks. Work on webpage also stalled, and webpage has now been superseded by abaco.

Abaco, written by Federico G. Benavento, supports most of the HTML 4.01 standard, including frames and tables.

See also

 Mothra – Another browser for Plan 9
 List of web browsers
 List of Plan 9 applications

References

External links
 The Abaco website
 
 

Web browsers for Plan 9
Discontinued web browsers
Free web browsers