omniomni/omni-engineering huggingface dataset:
Hard engineering. Hard engineering involves the construction of hydraulic structures to protect coasts from erosion. Such structures include seawalls, gabions, breakwaters, groynes and tetrapods.

Effects
Hard engineering can cause unintended environmental consequences, such as new erosion and altered sedimentation patterns, that are detrimental to the immediate human and natural environment or along down-coast locations and habitats.

Seawalls and bulkheads may have multiple negative effects on nearshore ecosystems due to the way they reflect wave energy instead of dissipating it. Energy from reflected waves can cause a scouring effect on substrate below the structure, resulting in loss or displacement of sediment. Over time, this effect may lead to a decrease in the size of intertidal and nearshore habitats. This effect is also known as coastal squeeze. In addition, bulkheads and seawalls offer no filtering for surface runoff, this means that anthropogenic pollutants and chemicals in armored areas may enter coastal waters relatively quickly.

Hard engineering, also called shoreline armoring, comes with other ecological effects on top of habitat loss and increased surface runoff. Structures that are built between land and sea are usually made of material not native to shoreline ecosystems. For instance, most sea walls and interlocking coastal defense structures are made of concrete, which may lend itself as habitat for invasive species rather than native ones. These structures also impede shoreline access, blocking some or all species from accessing refuge on dry land. In these armored areas, nutrient exchange between tidal and riparian ecosystems is threatened or cut off entirely. These issues arise from hard engineered sea shores, and lead many to believe that living shoreline techniques are far more beneficial ecologically and in terms of long-term erosion control.

Examples 
Examples of hard engineering include:
 Groynes – Low walls constructed at right angles to retain sediments that might otherwise be removed due to longshore drift. These structures absorb or reduce the energy of the waves and cause materials to be deposited on the updrift side of the groyne facing the longshore drift.
 Seawalls – Seawalls are constructed to protect coastlines against wave attack by absorbing wave energy. Most seawalls are made out of concrete or stone and are built parallel to the coast. They have been constructed in thousands of locations throughout the world.
 Rip-rap/rock armour – Boulders piled up against the coast that absorb the energy of the waves
 Gabions – wire cages filled with rocks to absorb wave energy

References 

Water and the environment
ABS Steels. ABS Steels are types of structural steel which are standardized by the American Bureau of Shipping for use in shipbuilding. 

ABS steels include many grades in ordinary-strength and two levels of higher-strength specifications.

All of these steels have been engineered to be optimal long-lived shipbuilding steels.  ABS does permit the use of other steels in shipbuilding, but discourages it, and requires more detailed engineering analysis.

Basic properties
All ABS steels are standard carbon steels.  As with other grades of steel, they have a specific gravity of 7.8.-

Material Properties

Ordinary-Strength
Ordinary-strength ABS shipbuilding steel comes in a number of grades, A, B, D, E, DS, and CS.  On certified steels, the plates are marked with the grade and a preceding "AB/", e.g. AB/A etc.

Yield point for all ordinary-strength ABS steels is specified as 34,000 psi (235 MPa), except for ABS A in thicknesses of greater than 1 inch (25 mm) which has yield strength of 32,000 psi (225 MPa), and cold flange rolled sections, which have yield strength of 30,000 psi (205 MPa).

Ultimate tensile strength of ordinary strength alloys is 58,000 - 71,000 psi (400-490 MPa), except for ABS A shapes and bars with 58,000 - 80,000 psi (400-550 MPa), and cold flanged sections with 55,000 - 65,000 psi (380-450 MPa).

The various grades have slightly differing alloy chemical ingredients, and differing fracture toughness.

Higher-Strength
Higher-strength ABS shipbuilding steel comes in six grades of two strengths, AH32, DH32, EH32, AH36, DH36, and EH36.

The 32 grades have yield strength of 45,500 psi (315 MPa), and ultimate tensile strength of 64,000 - 85,000 psi (440-590 MPa).

The 36 grades have yield strength of 51,000 psi (355 MPa), and ultimate tensile strength of 71,000 - 90,000 psi (490-620 MPa).

Per Steel Vessel Rules Part 2 Chapter 1 Section 3 Table 2 (pg 36).

Forms 
ABS steel is produced in a variety of different forms, including:
 Plates
 Bars
 Pipes
 Structural Shapes

References

Shipbuilding
Steels
Structural steel
Ilinga. Ilinga was an Australian car manufacturer founded in Melbourne by Tony Farrell and his partner, Daryl Davies, in business from 1974 to 1975. The company's only model, the AF-2, saw only two examples produced, despite having fifteen customers order one. Presented at the 1975 Melbourne Motor Show, the AF-2 was a potential luxury sports car, built to compete with the likes of Porsche and Aston Martin. The 1973 oil crisis and high price tag chased many potential customers away, as well as Australia's lack of automotive history. It was powered by a Leyland P76 engine modified to 220 horsepower. This engine was sourced from Rover. Plans for a four-door model in 1974 were scrapped before the factory was abandoned with broken Borg-Warner gearboxes littering the floor, as the transmission manufacturer refused to provide further assistance.  US $328,000 was spent before the company finally folded after just a year in business. The two AF-2 models constructed featured a digital clock, a delay switch which extinguished the lights and locked the doors if the driver didn't do so, a self-seeking cassette player with radio, electric windows, and a fully integrated air conditioning unit. One AF-2 resides in Museum Victoria, in Melbourne. The other was reportedly used as a daily driver by a fast food restaurant owner and re-painted green (the original color of both units was a very light powder blue). It awaits restoration.

The word "ilinga" is an Australian Aboriginal term for 'over the horizon'.

See also

 List of automobile manufacturers
 List of car brands

References

External links

Car manufacturers of Australia
Regenerative capacitor memory. Regenerative capacitor memory is a type of computer memory that uses the electrical property of capacitance to store the bits of data. Because the stored charge slowly leaks away, these memories must be periodically regenerated (i.e. read and rewritten, also called refreshed) to prevent data loss.

Other types of computer memory exist that use the electrical property of capacitance to store the data, but do not require regeneration. Traditionally these have either been somewhat impractical (e.g., the Selectron tube) or are considered to be suitable only as read-only memory (e.g., EPROM, EEPROM/Flash memory) since writing data takes significantly longer than reading.

History 
The first regenerative capacitor memory built was the rotating capacitor drum memory of the Atanasoff–Berry Computer (1942). Each of its two drums stored thirty 50-bit binary numbers (1500 bits each), rotated at 60 rpm and was regenerated every rotation (1 Hz refresh rate).

The first random access regenerative capacitor memory was the Williams tube (1947). As fitted to the first practical programmable digital computer, a single Williams tube held a total of 2560 bits, arranged in two 'pages'. One page was an array of thirty two 40-bit binary numbers, the capacity of a basic Williams-Kilburn Tube. The refresh rate required varied depending on the type of CRT used.

The modern DRAM (1966) is a regenerative capacitor memory.

Notes

References

Further reading 
 

Computer memory
Capacitance
2024 aluminium alloy. 2024 aluminium alloy is an aluminium alloy, with copper as the primary alloying element. It is used in applications requiring a high strength-to-weight ratio, as well as good fatigue resistance. It is weldable only through friction welding, and has average machinability. Due to poor corrosion resistance, it is often clad with aluminium or Al-1Zn for protection, although this may reduce the fatigue strength.  In older systems of terminology, 2XXX series alloys were known as duralumin, and this alloy was named 24ST.

2024 is commonly extruded, and also available in alclad sheet and plate forms. It is not commonly forged (the related 2014 aluminium alloy is, though).

Basic properties 
Aluminium alloy 2024 has a density of 2.78 g/cm3 (0.1  lb/in3), electrical conductivity of 30% IACS, Young's modulus of 73 GPa (10.6 Msi) across all tempers, and begins to melt at .

Chemical composition 
The alloy composition of 2024 is:
 Aluminium (90.7–94.7%)
 Silicon no minimum, maximum 0.5% by weight
 Iron no minimum, maximum 0.5%
 Copper minimum 3.8%, maximum 4.9%
 Manganese minimum 0.3%, maximum 0.9%
 Magnesium minimum 1.2%, maximum 1.8%
 Chromium no minimum, maximum 0.1%
 Zinc no minimum, maximum 0.25%
 Titanium no minimum, maximum 0.15%
 Other elements no more than 0.05% each, 0.15% total

Mechanical properties 
The mechanical properties of 2024 depend greatly on the temper of the material.

2024-O 
2024-O temper aluminium has no heat treating. It has an ultimate tensile strength of , and a maximum yield strength of no more than .  The material has elongation (stretch before ultimate failure) of 10–25%, this is the allowable range per applicable AMS specifications.

2024-T3 
T3 temper 2024 sheet has an ultimate tensile strength of  and yield strength of at least .  It has an elongation of 10–15%.

2024-T4 
Solution treated at foundry and naturally aged.

2024-T5 
Cooled from hot-working and artificially aged (at elevated temperature)

2024-T351 
T351 temper 2024 plate has an ultimate tensile strength of  and yield strength of .  It has elongation of 20%.

Uses 
Due to its high strength and fatigue resistance, 2024 is widely used in aircraft, especially wing and fuselage structures under tension. Additionally, since the material is susceptible to thermal shock, 2024 is used in the qualification of liquid penetrant tests outside of normal temperature ranges.

References

Further reading
 "Properties of Wrought Aluminium and Aluminium Alloys: 2024, Alclad 2024", Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, Vol 2, ASM Handbook, ASM International, 1990, pp. 70–71.

Aluminium alloy table 

2024
Aluminium–copper alloys
Interactive activation and competition networks. Interactive activation and competition (IAC) networks are artificial neural networks used to model memory and intuitive generalizations. They are made up of nodes or artificial neurons which are arrayed and activated in ways that emulate the behaviors of human memory.

The IAC model is used by the parallel distributed processing (PDP) Group and is associated with James L. McClelland and David E. Rumelhart; it is described in detail in their book Explorations in Parallel Distributed Processing: A Handbook of Models, Programs, and Exercises. This model does not contradict any currently known biological data or theories, and its performance is close enough to human performance as to warrant further investigation.

References

External links
A tribute to interactive activation
Video overview of IAC networks and a description of how to build them using free software.

Artificial neural networks
Lineman. Lineman or linesman may refer to:

In personal roles:
Lineworker, one who installs and maintains electrical power, telephone, or telegraph lines
Lineman (gridiron football), a position in American football
Head linesman, the American football official in charge of the chain crew 
Assistant referee (association football) or linesman
Linesmen, officials in ice hockey
Line umpire, an official in tennis

In other uses:
Western Union splice or Lineman splice, a type of electrical wiring splice
"The Lineman", a song composed by Sam Spence for Associated Production Music
 La Linea (TV series) or Lineman, an Italian animated short series
Linesman/Mediator Air Defence RADAR system
 Lineman (film), a 2024 Kannada-language comedy drama film

See also
"Wichita Lineman", a song written by Jimmy Webb in 1968, first recorded by Glen Campbell and widely covered since
Picryl chloride. Picryl chloride is an organic compound with the formula ClC6H2(NO2)3.  It is a bright yellow solid that is highly explosive, as is typical for polynitro aromatics such as picric acid. Its detonation velocity is 7,200 m/s.

Reactions
The reactivity of picryl chloride is strongly influenced by the presence of three electron-withdrawing nitro groups.  Consequently picryl chloride is an electrophile as illustrated by its reactivity toward sulfite to give the sulfonate:
ClC6H2(NO2)3  +  Na2SO3  →   NaO3SC6H2(NO2)3  +  NaCl

Picryl chloride is also a strong electron acceptor. It forms a 1:1 charge-transfer complex with hexamethylbenzene.

References

Explosive chemicals
Nitrobenzene derivatives
Beauchamp Tower. Beauchamp Tower (13 January 1845  – 31 December 1904) was an English inventor and railway engineer who is chiefly known for his discovery of full-film or hydrodynamic lubrication.

Early life
Beauchamp Tower was born the son of Robert Beauchamp Tower, rector of Moreton, Essex and educated at Uppingham School, Rutland. He decided at the age of 16 that he wanted to become an engineer and received early training at the Armstrong Works at Elswick, where he stayed for a few months as a draughtsman after completing his four-year apprenticeship.

Inventions 

Beauchamp Tower held several patents regarding an apparatus for maintaining a constant plane in a floating vessel. The apparatus is based on the gyroscopic principle.
One of the possible applications of this patent was steadying guns on shipboard. In 1977, he was named by Duncan Dowson as one of the 23 "Men of Tribology".

Influence 
Tower's work on lubrication influenced many other engineers, including Osborne Reynolds, who acknowledged Tower in his 1886 paper on lubrication and the viscosity of olive oil. Lord Kelvin credited Tower with the idea of a chain and pulleys as part of his Tide-predicting machine.

References

1845 births
English railway mechanical engineers
English inventors
1904 deaths
People from Epping Forest District
Tribologists
Dead water. Dead water  is the nautical term for a phenomenon which can occur when there is strong vertical density stratification due to salinity or temperature or both. It is common where a layer of fresh or brackish water rests on top of denser salt water, without the two layers mixing. The phenomenon is frequently, but not exclusively, observed in fjords where glacier runoff flows into salt water without much mixing. The phenomenon is a result of energy producing internal waves that have an effect on the vessel. The effect can also be found at density boundaries between sub surface layers.

In the better known surface phenomenon a ship traveling in a fresh water layer with a depth approximately equal to the vessel's draft will expend energy creating and maintaining internal waves between the layers. The vessel may be hard to maneuver or can even slow down almost to a standstill and "stick". An increase in speed by a few knots can overcome the effect. Experiments have shown the effect can be even more pronounced in the case of submersibles encountering such stratification at depth.

The phenomenon, long considered sailor's yarns, was first described for science by Fridtjof Nansen, the Norwegian Arctic explorer. Nansen wrote the following from his ship Fram in August 1893 in the Nordenskiöld Archipelago near the Taymyr Peninsula:

Nansen's experience led him to request physicist and meteorologist Vilhelm Bjerknes to study it scientifically. Bjerknes had his student, Vagn Walfrid Ekman, investigate. Ekman, who later described the effect now bearing his name as the Ekman spiral, demonstrated the effect of internal waves as being the cause of dead water.

A modern study by the Université de Poitiers entities CNRS' Institut Pprime and the Laboratoire de Mathématiques et Applications revealed that the effect is due to internal waves moving the vessel back and forth. Two types occur. The first as observed by Nansen causes a constant abnormally slow progress. The second, Ekman type, causes speed oscillations. The Ekman type may be temporary and become Nansen type as the vessel escapes the particular regime causing the oscillating speed. An interesting historical possibility is that the effect caused Cleopatra's ships difficulties and loss at the Battle of Actium in 31 BC in which legend attributes the loss to remora (suckerfish) attaching to the hulls.

See also 

Ekman spiral
Ice drift
Iceberg
Internal wave
Nansen's Fram expedition
Nordenskiöld Archipelago
Polar ice cap
Polar ice packs
Polynya
Sea ice
Shelf ice
Vagn Walfrid Ekman – Swedish oceanographer

References

External links 
 Short movie demonstrating the phenomenon with a model
 Description of Dead Water
  Explanation of dead water
 New Scientist article
'dead water'  Encyclopædia Britannica Online. 3 December 2009

Nautical terminology
Physical oceanography
Waves
Jean Calvignac. Jean Calvignac is an IBM Fellow and was responsible for the architecture of PowerNP, an IBM network processor. He holds more than 220 patents.

Career 

In 1998, at the IBM Laboratory in the Research Triangle Park, Calvignac and his team initiated the IBM network processor activities. He had previously been responsible for system design of the ATM switching products, which he initiated with his team in 1992 at the IBM Laboratory in La Gaude, France. Before that, he had held different management and technical leader positions for architecture and development of communication controller products at the La Gaude Laboratory. Calvignac joined IBM in 1971 as a development engineer in telephone switching products. He received an engineering degree in 1969 from the Grenoble Institute of Technology, France.

Calvignac has been awarded more than 220 patents, mostly in the field of communication and networking. He has contributed to standards and a few scientific papers.

He was named an IBM Fellow in 1997, IBM's highest technical honor. Calvignac is a Fellow of the IET (in Europe) and a Senior Member of the IEEE.

References

External links 
 

French computer scientists
French electrical engineers
20th-century French inventors
Living people
Year of birth missing (living people)
IBM Fellows
IBM people
Fellows of the Institution of Engineering and Technology
Senior members of the IEEE
Grenoble Institute of Technology alumni
20th-century French engineers
21st-century French engineers
SAPM mine. The SAPM (Scatterable Anti-Personnel Fragmentation Mine) is a Chinese scatterable anti-personnel fragmentation mine. It is typically deployed from either 122 mm rockets or truck based mine layers. Once the mine hits the ground, two tripwires are deployed to a maximum distance of 10 meters from the mine. Tension on these wires triggers the mine.

Specifications
 Height: 97 mm
 Diameter: 52 mm
 Weight: 0.58 kg
 Explosive content: 0.052 kg of phlegmatized RDX
 Operating pressure: 0.1 to 0.4 kg pull

References
 Jane's Mines and Mine Clearance 2005-2006

Anti-personnel mines
404 Long Range Patrol and Training Squadron. 404 Long Range Patrol and Training Squadron is a long range patrol and training squadron in the Royal Canadian Air Force. The squadron was originally No. 404 Squadron of the Royal Canadian Air Force (RCAF) and later the Canadian Forces Air Command.

History

The squadron was formed at Thorney Island in Sussex, England on 15 April 1941 under Royal Air Force operational control. Tasked with coastal patrol and attack, the squadron flew the Bristol Blenheim Mk.IV & later the Beaufighter.  From May 1944 to September 1944 they were based at RAF Davidstow Moor in Cornwall, England.

As part of the RAF Dallachy strike wing of four Beaufighter-equipped squadrons, they took part in an attack on German ships on the Norwegian coast on 9 February 1945. The ships included a destroyer and "flak" ships as well as merchantmen. The ships were located in a fjord and German fighter aircraft scrambled in defence. As a result of the heavy losses to the Dallachy Wing the attack was subsequently called "Black Friday". The squadron disbanded on 25 May 1945.

The squadron was reformed on April 30, 1951, at RCAF Station Greenwood as 404 Maritime Reconnaissance Squadron. On 17 July 1956, 404 Squadron was redesignated as a Maritime Patrol squadron, and when the CP-140 Aurora came into service the title was changed again to 404 Maritime Patrol and Training Squadron. The current title is 404 Long Range Patrol and Training (LRP&T) Squadron.

Currently, 404 Sqn serves as the Operational Training Unit (OTU) for Aircrew and Maintenance personnel who work on the CP140 Aurora.

Aircraft operated
 Bristol Blenheim
 Bristol Beaufighter
 De Havilland Mosquito
 Avro Lancaster
 Beech Expeditor
 Lockheed Neptune
 Canadair Argus
 Lockheed CP-140 Aurora and CP-140A Arcturus (trainer for CP-140)

Notable personnel
Allan Bundy
Ken Gatward

External links

 
DND – History of 404 Squadron

Canadian Forces aircraft squadrons
Military units and formations established in 1941
Royal Canadian Air Force squadrons
RCAF training units
Disk Manager. Disk Manager is a discontinued software (that was a popular 1980s and 1990s) and documentation package for MS-DOS and PC DOS computers, useful for self-installing personal computer hard disks. It was written by Ontrack, a company that is now part of KLDiscovery.

Installation covered different aspects:

 explaining personal computer hardware concepts
 documenting switches of many of the existing disks
 putting into place custom device drivers which circumvented BIOS limitations, notably those related to maximum disk or partition size and logical block addressing
 providing testing and informational utilities

Drivers could be either DOS-type, or replacement master boot record code.

Diskettes with Disk Manager were provided by some disk manufacturers (e.g. IBM), in custom OEM versions, supporting all of their models.

Not long after launching in 1985, Ontrack also started providing computer disk data recovery services as Ontrack Data Recovery.

Version history
Version 5.0 for Windows was released on 2004-06-23. It includes DOS versions of Ontrack Disk Manager and Ontrack Data Recovery.

Competing products
Other products that, like Disk Manager from OnTrack Computer Systems, perform hard drive geometry translation to circumvent BIOS limitations:

 SpeedStor from Storage Dimensions
 EZ-Drive from Micro House (also distributed by Western Digital)

References

External links
 Ontrack Data Recovery

Utilities for Windows
Utility software