omniomni/omni-engineering huggingface dataset:
Disjoining pressure. In surface chemistry, disjoining pressure (symbol ) according to an IUPAC definition arises from an attractive interaction between two surfaces. For two flat and parallel surfaces, the value of the disjoining pressure (i.e., the force per unit area) can be calculated as the derivative of the Gibbs energy of interaction per unit area in respect to distance (in the direction normal to that of the interacting surfaces). There is also a related concept of disjoining force, which can be viewed as disjoining pressure times the surface area of the interacting surfaces.

The concept of disjoining pressure was introduced by Derjaguin (1936) as the difference between the pressure in a region of a phase adjacent to a surface confining it, and the pressure in the bulk of this phase.

Description 
Disjoining pressure can be expressed as:

where (in SI units):
  - disjoining pressure (N/m2)
  - the surface area of the interacting surfaces (m2)
  - total Gibbs energy of the interaction of the two surfaces (J)
  - distance (m)
 indices  and  signify that the temperature, volume, and the surface area remain constant in the derivative.

Using the concept of the disjoining pressure, the pressure in a film can be viewed as:

where:
  - pressure in a film (Pa)
  - pressure in the bulk of the same phase as that of the film (Pa)

Disjoining pressure is interpreted as a sum of several interactions: dispersion forces, electrostatic forces between charged surfaces, interactions due to layers of neutral molecules adsorbed on the two surfaces, and the structural effects of the solvent.

Classic theory predicts that the disjoining pressure of a thin liquid film on a flat surface as follows,

where:
  - Hamaker constant (J)
  - liquid film thickness (m)

For a solid-liquid-vapor system where the solid surface is structured, the disjoining pressure is affected by the solid surface profile, , and the meniscus shape,  

where:
  - solid-liquid potential (J/m6)
The meniscus shape can be by minimization of total system free energy as follows 

where:
  - total system free energy including surface excess energy and free energy due to solid-liquid interactions (J/m2)
  - meniscus shape (m)
  - slope of meniscus shape (1)

In the theory of liquid drops and films, the disjoining pressure can be shown to be related to the equilibrium liquid-solid contact angle  through the relation

where  is the liquid-vapor surface tension and  is the precursor film thickness.

See also 
Capillary condensation
Capillary pressure
Hamaker constant
Thin-film equation

References

Surface science
The Ancient Art of War in the Skies. The Ancient Art of War in the Skies is a video game developed by Evryware in 1992 for MS-DOS as a sequel to The Ancient Art of War and The Ancient Art of War at Sea. In 1993 conversions were published for Amiga and Atari ST.

Gameplay
The Ancient Art of War in the Skies is a game of air combat simulation in which the player controls the aircraft of either the British or German army in World War I against opponents such as Lord Kitchener, Ferdinand Foch, Kaiser Wilhelm II, fictional enemy Helmut von Spike, or even Sun Tzu.

The game acts in two dimensions. In the first one the player spends most of its time on the overhead map. They can plan the strategy and set the goals and routes for aircraft. In the second one, when the aircraft reaches its destination, the game switches to an arcade section. There are also two: a side-scrolling dog fights where the goal is to destroy the enemy aircraft shooting at them and overhead bombings where the player has to release bombs at the marked targets. Arcade sequences can be skipped and dealt by computer's calculations based on different variables.

Reception
The game was reviewed in 1993 in Dragon #190 by Hartley, Patricia, and Kirk Lesser in "The Role of Computers" column. The reviewers gave the game 3 out of 5 stars. Computer Gaming World called it "a cute combination of strategy and action gaming" that would not likely appeal to fans of flight simulators or wargames. A 1993 survey in the magazine of wargames gave the game three-plus stars out of five.

ST Format's Rob Mead wrote: "At last, a war simulation which you don't need a degree in Advanced Physics to play. Ancient Arts is an original and addictive approach to a genre which is all to often bogged down in tedious manouvering and unnecessary attention to detail".

Reviews
 Amiga Games - June 1993
 Computer Gaming World - September 1993
 PC Games (Germany) - January 1993
 PC Player (Germany) - March 1993
 ST Format - September 1993

References

External links
 
 
 

1992 video games
Amiga games
Atari ST games
Cultural depictions of Herbert Kitchener, 1st Earl Kitchener
Cultural depictions of Manfred von Richthofen
Cultural depictions of Wilhelm II
DOS games
Evryware games
MicroProse games
Single-player video games
Video games based on real people
Video games developed in the United States
Video games scored by Jeff Briggs
Hot Shot!. Hot Shot! is the robotics competition event in the 2009-2010 FIRST Tech Challenge. Two teams compete to score points by depositing whiffle balls into designated areas.

Game Overview

Field Description
Hot Shot! is played by four robots on a 12 foot by 12 foot field. Robots are paired together to form red and blue alliances of two teams each. Each alliance starts on a different side of the field, in spots designated by red and blue taped off squares.
There are 3 goal areas, the low goal, the high goal, and the off field goal. The low goal and the high goal are centered on the field. The high goal has a pivot bar that allows it to be spun by a robot contacting the spin bar.  The off field goal is four feet from the field.
There are ball dispensers made out of PVC pipe, full of balls, at each corner of the field. There is a wooden deflector beneath each of the dispensers, angled toward the center of the field that makes the balls roll in different directions. The balls are released from the chutes by a pivoting trigger.

Round Timing
Each round lasts two and a half minutes. The first 30 seconds are composed of an autonomous period, where the robots are controlled completely by a program on the NXT. The next 2 minutes are a "Teleop," or remote controlled period where the robots are controlled remotely through the Bluetooth on the NXT. The last 30 seconds of the teleop period are known as the end game.

Scoring
The off field goal can only be scored in during the end game.
The following points are awarded for normal white balls in each of the corresponding goals:

Yellow curve balls double the score in the goal that they are scored in. They can be released by the team captain during the end game.

References

External links
 Hot Shot Game Information 
 FIRST FTC 2009 Game Manual
 FIRST FTC 2009 One Page Game Overview

2009 in robotics
Altoona Works BP4. The Altoona Works BP4 is a  B-B battery-electric locomotive rebuilt by the Altoona Works of the Norfolk Southern Railway. It was created in 2007 by replacing the diesel prime mover of an EMD GP38 (Norfolk Southern #2911, formerly Conrail #7732) with 1,080 12-volt lead-acid batteries and associated control equipment. The converted locomotive was redesignated Norfolk Southern #999.

Design

Despite appearing somewhat similar to a conventional diesel electric locomotive, the BP4 has no diesel engine; battery charging is provided by plugging in an external power source. Battery life is extended by the use of regenerative braking, which returns about 35% of braking power to the batteries. The BP4 is designed to operate 3 shifts on a single battery charge. This conversion significantly alters the external appearance of the locomotive, with the cab (which is actually brand new) being moved forward on the frame to make room for a large louvered battery box, which takes the place of the locomotive's long hood. The fuel tank is similarly replaced with another battery box.

History
BP4 development was undertaken by Norfolk Southern, along with Brookville Equipment, Penn State University, the United States Department of Energy, and the Federal Railroad Administration. $1.3 million in federal funding subsidized the program. The locomotive was initially converted in 2007; after initial battery issues, a better battery management system was installed in 2009.  A further rebuild was undertaken in 2014, changing the batteries from lead-acid to lead-carbon.

Despite the continued tweaking, NS 999 was unable to fulfill the railroad's requirements and the project was dropped.  Norfolk Southern put the 999 up for auction, along with several other locomotives, in November 2019. 999 was purchased by Rail Propulsions Systems, where it was upgraded for eventual use in the Los Angeles Basin region.

References

B-B locomotives
Electric locomotives of the United States
Battery electric vehicles
EPA Tier 2-compliant locomotives of the United States
Norfolk Southern Railway locomotives
Rebuilt locomotives
Standard gauge locomotives of the United States
Unique locomotives
Shunting locomotives
EgyptAir Flight 864. EgyptAir Flight 864 was a flight from Rome Fiumicino Airport to Tokyo International Airport, via Cairo, Bombay, and Bangkok. On 25 December 1976, the Boeing 707 crashed into an industrial complex in Bangkok. All 52 people on board were killed, plus 19 on the ground in the crash.

Aircraft 
The aircraft was a Boeing 707-366C with the serial number 20763 and serial 871, that had its maiden flight on 25 August 1973. The aircraft was registered as SU-AXA and was delivered to EgyptAir, and entered service on 20 September the same year. The aircraft was powered by Pratt & Whitney JT3D-7 turbofan engines.

Accident 
Flight 864 was a regularly scheduled international passenger flight from Rome to Tokyo with stopovers in Cairo, Bombay and Bangkok. With 9 crew members and 43 passengers on board, flight 864 approached Bangkok. At 20:30 GMT (03:30 local time), the crew contacted the approach controller and reported about the distance of  from the airport’s radio beacon. At this time, conditions were reported as calm, with cloudiness from 2/8 to 4/8 at the lower border of , air temperature of  at a dew point of , visibility of , and an airfield pressure of 1007 mB. Having received the radar vector to the "BK" non-directional beacon (NDB), the crew began their approach to runway 21L. The crew reported their observations. The controller cleared the flight to land, and the crew acknowledged the transmission. Then at about 03:45, the aircraft crashed into a weaving mill building in an industrial area of the city, located  northeast of the end of runway 21L. The aircraft exploded on impact, and all 52 people on board were killed. The weaving mill was also destroyed, with 19 people killed on the ground. The total number of victims was 71 people. At that time, the crash was the deadliest aviation disaster to occur in Thailand (it is now the sixth).

Cause 
Pilot error was determined to be the cause of the crash. EgyptAir claimed that the Bangkok control tower had provided inadequate weather information to the crew of Flight 864. The crew had also reduced the aircraft's vertical speed and did not monitor its height properly.

References 

Airliner accidents and incidents involving controlled flight into terrain
Accidents and incidents involving the Boeing 707
Aviation accidents and incidents in Thailand
Aviation accidents and incidents in 1976
864
1976 in Thailand
December 1976 events in Asia
History of Bangkok
Airliner accidents and incidents caused by pilot error
Railpower RP20BD. The RP20BD is a diesel-electric switcher locomotive built by Railpower Technologies.  It is a "genset" locomotive, having three engine-generator sets.

The engines are computer controlled, with the computer stopping and starting engines on a rotating basis, as required to produce the horsepower needed at any given moment.

RP20BDs are rebuilt from older locomotives such as the General Electric Dash 7 series and EMD General Purpose series.

References

B-B locomotives
Diesel–electric locomotives of the United States
Railpower locomotives
EPA Tier 2-compliant locomotives of the United States
Rebuilt locomotives
Standard gauge locomotives of the United States
Railway locomotives introduced in 2008
Shunting locomotives
James Madison Porter III. James Madison Porter III (1864–1928) was an American civil engineer notable for his role in designing two unique bridges across the Delaware River and for his development of the civil engineering program at Lafayette College. His grandfather, James Madison Porter, was one of the college's founders. Porter III served on the civil engineering faculty at Lafayette from 1890 to 1917 and was an early advocate for materials testing.

In addition to his academic achievements, Porter designed the Northampton Street Bridge between Easton, Pennsylvania, and Phillipsburg, New Jersey, which is now one of few eyebar cantilever bridges remaining in the U.S. and notable for its high level of ornamentation. Porter also served as consulting engineer to John A. Roebling and Sons on the Riegelsville Bridge further downstream, a wire-rope suspension bridge. Both bridges have national significance for their unique designs and have been documented by the Historic American Engineering Record. Drawings and calculations for these bridges are among Porter's papers collected at the Northampton County Historical and Genealogical Society, the Delaware River Joint Toll Bridge Commission archives, and in Special Collections at Lafayette College's Skillman Library.

References

External links

1864 births
1928 deaths
American engineers
American bridge engineers
Lafayette College alumni
Porter family
Margin-infused relaxed algorithm. Margin-infused relaxed algorithm (MIRA) is a machine learning algorithm, an online algorithm for multiclass classification problems. It is designed to learn a set of parameters (vector or matrix) by processing all the given training examples one-by-one and updating the parameters according to each training example, so that the current training example is classified correctly with a margin against incorrect classifications at least as large as their loss. The change of the parameters is kept as small as possible.

A two-class version called binary MIRA simplifies the algorithm by not requiring the solution of a quadratic programming problem (see below). When used in a one-vs-all configuration, binary MIRA can be extended to a multiclass learner that approximates full MIRA, but may be faster to train.

The flow of the algorithm looks as follows:

   Input: Training examples 
   Output: Set of parameters 

    ← 0,  ← 0
   for  ← 1 to 
     for  ← 1 to 
        ← update  according to 
        ← 
     end for
   end for
   return 

The update step is then formalized as a quadratic programming problem: Find , so that , i.e. the score of the current correct training  must be greater than the score of any other possible  by at least the loss (number of errors) of that  in comparison to .

References

External links
adMIRAble – MIRA implementation in C++
Miralium – MIRA implementation in Java
MIRA implementation for Mahout in Hadoop

Classification algorithms
Pará-class destroyer. Pará-class destroyer may refer to:
 Pará-class destroyer (1908), a class of ten destroyers built for the Brazilian Navy between 1908 and 1910
 Pará-class destroyer (1959) or Fletcher-class destroyer, a class of destroyers built by the United States during World War II
 Pará-class destroyer (1989)  four  transferred from the United States to Brazil
Intrépida-class fast attack craft. The Intrépida class is a class of fast attack craft that was built by Lürssen for the Argentine Navy in the early 1970s. The ships are based on Lürssen's TNC 45 design.

Operational history 
As of 2021 Intrépida was reported active and participated in a sea exercise with the destroyer Sarandi, the corvettes Espora, Spiro, Robinson and Gómez Roca and with aircraft from Argentine naval aviation.

Both vessels were reported active on exercises in 2022.

Ships in the class 
 ARA Intrépida (P-85)
 ARA Indómita (P-86)

See also 
 Albatros-class fast attack craft (Type 143)
 Gepard-class fast attack craft (Type 143A)
 Tiger-class fast attack craft (Type 148)
 Sa'ar 4-class missile boat (Reshef)

References

Notes

Bibliography
 Guia de los buques de la Armada Argentina 2005-2006. Ignacio Amendolara Bourdette, , Editor n/a. (Spanish/English text)

Further reading

External links
 Argentine Navy official site, specifications and brief history  (in Spanish)

 
Ships built in Bremen (state)
Missile boat classes
Railpower RP14BD. The RP14BD is a diesel-electric switcher locomotive built by Railpower Technologies.  It is a "genset" locomotive, having two engine-generator sets.

The engines are computer controlled, with the computer stopping and starting engines on a rotating basis, as required to produce the horsepower needed at any given moment.

RP14BDs are rebuilt from older locomotives. They can be built with or without an operating cab.

See also 
 Genset locomotive

References

Further reading

External links 

 RJ Corman Railpower Genset & Hybrid Switchers

B-B locomotives
Diesel–electric locomotives of the United States
Railpower locomotives
EPA Tier 2-compliant locomotives of the United States
Rebuilt locomotives
Standard gauge locomotives of the United States
Locomotives with cabless variants
Shunting locomotives
Hamaker. Hamaker may refer to:

Hendrik Arent Hamaker, Dutch orientalist
Hugo Christiaan Hamaker, Dutch scientist responsible for Hamaker theory
Hamaker constant, definition for a Van der Waals (VdW) body-body interaction
Hamaker Force Interactions, sum of the attractive or repulsive forces between molecules
John D. Hamaker, pioneer of soil remineralization
Hamaker theory, explains the van der Waals forces between objects larger than molecules

See also

Atlee Hammaker, former Major League Baseball left-handed pitcher 
Haymaker (disambiguation)
John Haymaker, founder of Franklin Township, Portage County, Ohio
John Wanamaker, United States merchant
Zoë Wanamaker, American-British actress
Wanamaker's, department store
Nikolai Eberhardt. Nikolai Eberhardt was a German émigré physicist and author of From the Big Bang to the Human Predicament (1998).

Biography 
Born 1930 in Estonia, Eberhardt has German, Swedish and Russian ancestry. He studied philosophy in Graz, Austria and physics in Munich, gaining a physics diploma in 1957, and a Doctor of Science degree (Dr. rer. nat.) in 1962 from the Institute of Technology in Munich. He served as Professor of Electrical Engineering at Lehigh University (Emeritus from 1995). Intermittently he also served as adjunct professor in the Science, Technology and Society program. Besides numerous publications, he has multiple patents to his credit in the areas of color-television tubes, microwave devices, robotics and instrumentation. He was Digest Editor of the 1976 IEEE International Microwave Symposium.

References

External links 
 Lehigh University Faculty Profile
 A review of the latest book
 2009 IPPY Awards
 Partial Patent List
 AES E-Library: A Quasi-Linear Frequency Divider

20th-century German physicists
German science writers
20th-century German philosophers
German male non-fiction writers
Year of birth missing (living people)
Lehigh University faculty
Simple Firmware Interface. Simple Firmware Interface (SFI) is developed by Intel Corporation as a lightweight method for firmware to export static tables to the operating system. It is supported by Intel's hand-held Moorestown platform.

SFI tables are data structures in memory, and all SFI tables share a common table header format.  The operating system finds the system table by searching 16 byte boundaries between physical address  and .  SFI has CPU, APIC, Memory Map, Idle, Frequency, M-Timer, M-RTC, OEMx, Wake Vector, I²C Device, and a SPI Device table.

SFI provides access to a standard ACPI XSDT (Extended System Description Table). XSDT is used by SFI to prevent namespace collision between SPI and ACPI. It can access standard ACPI tables such as PCI Memory Configuration Table (MCFG).

SFI support was merged into Linux kernel 2.6.32-rc1; the core SFI patch is about 1,000 lines of code. Linux is the first operating system with an SFI implementation. Linux kernel 5.6 marked SFI as obsolete.

SFI support was removed in Linux kernel 5.12.

References

External links 
 
 

Firmware
Intel
NRE 3GS21C. The NRE 3GS21C is a low-emissions diesel genset locomotive built by National Railway Equipment (NRE). It is powered by three Cummins QSK19C I6 engines with each one developing  and creating a total power output of . Instead of a single prime mover, the NRE genset locomotive has three engines that each can be turned off or on as power is needed reducing overall diesel emissions and improving fuel efficiency. At least 27 3GS21C genset locomotives have been produced to date at NRE's Mount Vernon shops in Southern Illinois. The main difference between this and the NRE 3GS21B is that these units are on C-C (six wheel) trucks and the others are on B-B (four wheel) trucks.

Original buyers

Flexibility 
Because the engines are modular, flexibility is obtained:

 If one engine fails, the others can continue at reduced power.
 If a lower axle load is needed, one engine can be left off.
 When reduced power is needed, one or more of the engines can be turned off, saving fuel and wear and tear.
 The QSK19C engine is common to the four variants of the NRE 3GS21C locomotive.
 The QSK19C engine is widely used for non-railway applications, and spare parts are readily available.

See also
 NRE 3GS21B

References

C-C locomotives
NRE locomotives
Railway locomotives introduced in 2008
Diesel–electric locomotives of the United States
EPA Tier 2-compliant locomotives of the United States
Rebuilt locomotives
Standard gauge locomotives of the United States
RoboTuna. The RoboTuna is a robotic fish project involving a series of robotic fish designed and built by a team of scientists at the Massachusetts Institute of Technology (MIT) in the US.

The Project 

The project started in 1993. Their aim was to investigate the possibility of constructing a robotic submarine that could reproduce the way tunas swim and see if they could find a superior system of propulsion for the Autonomous Underwater Vehicles (AUVs). Their experiment was a success as they discovered that their fish was both more maneuverable and used less energy than other robotic submarines. The Science Museum in London, UK has one on display in their geophysics and oceanography section .

Improvements 
While the early results were successful the RoboTuna was not able to replicate the bursts of acceleration that real tuna were able to manage. Researchers improved the design using a genetic algorithm, in which the best systems will "get to have virtual offspring" according to researcher David Barrett. Early incarnations worked poorly but as the system evolved the RoboTuna's abilities improved. Visualization techniques showed that the system had evolved so that the RoboTuna was taking advantage of vortices that it created.  A swish of its tail one way creating a vortex, which was then used by a swish the other way - propelling it off the vortex it had created. This technique not only helps to with normal swimming but explains the impressive standing start speeds of real tuna.

The Researchers 
The team involved in the  project included: Michael Triantafyllou, David Barrett who built  the first RoboTuna (Charlie I) in 1995 for his PhD thesis, and David Beal and Michael Sachinis, who introduced several modifications including a cable-pulley system to produce RoboTuna II.

See also
Tunabot

References 

Electromechanical engineering
Robotic animals
Robots of the United States
1995 robots
Massachusetts Institute of Technology
Underwater robots
Tuna