omniomni/omni-engineering huggingface dataset:
Explosive ROF. An explosive ROF was a UK government-owned Royal Ordnance Factory (ROF), which specialised in manufacturing explosives during and after World War II. In World War I, the name used in the UK for government-owned explosives factories was National Explosives Factory; the cordite factory at Gretna was known as HM Factory, Gretna.

These Second World War factories were built for the Ministry of Supply with the Ministry of Works, in all cases except ROF Irvine, acting as agent. Explosive ROFs specialised in producing either high-explosives, such as TNT (trinitrotoluene) or RDX; or propellants, such as cordite, but there were minor exceptions to this demarcation. The products from these explosive ROFs were shipped to filling factories for filling into munitions.

Pyrotechnics, such as fuses and screening smokes, tended to be made at the Filling Factories and filled directly into munitions.

Comparable WW II factories not part of the ROF organisation

ICI and Ministry of Supply agency factories
A number of UK World War II explosives factories were built and owned by ICI. These privately-owned explosives factories were not considered part of the ROF organisation and they were not called ROFs. ICI also managed numerous munitions factories constructed with Ministry of Supply funding; these were known as agency factories. ICI Nobel's Ardeer site and its World War II agency factories produced, for example, 35% of the combined ROF and Agency Factories output of Cordite and 15% of the combined output of TNT.

Royal Naval Factories
In both World War I and II the Royal Navy had its own government-owned factories producing propellants and explosives, for naval guns. These were the Royal Navy Cordite Factory, Holton Heath (RNCF), Dorset (World War I & World War II), and the Royal Navy Propellant Factory, Caerwent (RNPF), Monmouthshire (World War II only), respectively. They both were closed as explosive manufacturing sites after World War II. Naval propellants were then manufactured at ROF Bishopton and filled at ROF Chorley, and later ROF Glascoed.

National Explosives Factories (WW I)
HM Factory, Gretna
NEF Pembrey
Barnbow National Filling Factory No 1, later ROF Barnbow

To be expanded

Royal Navy Factories (WW I and WW II)
Royal Navy Cordite Factory, Holton Heath (RNCF)
Royal Naval Gun Factory, Westhoughton.  Formerly Messrs Musgrave and Sons.
Royal Navy Propellant Factory, Caerwent (RNPF)

UK high-explosive ROFs (WW II)
ROF Bridgwater
ROF Drigg
ROF Irvine
ROF Pembrey

Propellant ROFs (WW II)
ROF Bishopton
ROF Ranskill
ROF Sellafield
ROF Wrexham

Notes

References
 Cocroft, Wayne D., (2000). Dangerous Energy: The archaeology of gunpowder and military explosives manufacture. Swindon: English Heritage. .
 Kohan, C.M., (1952). History of the Second World War: United Kingdom Civil Series: Works and Buildings. London: Her Majesty's Stationery Office and Longmans, Green and Co.
 Reader, W.J. (1975). Imperial Chemical Industries: A History. Volume II: The First Quarter-Century 1926-1952. London: Oxford University Press. .
Umklapp scattering. In crystalline materials, Umklapp scattering (also U-process or Umklapp process) is a scattering process that results in a wave vector (usually written k) which falls outside the first Brillouin zone. If a material is periodic, it has a Brillouin zone, and any point outside the first Brillouin zone can also be expressed as a point inside the zone. So, the wave vector is then mathematically transformed to a point inside the first Brillouin zone. This transformation allows for scattering processes which would otherwise violate the conservation of momentum: two wave vectors pointing to the right can combine to create a wave vector that points to the left. This non-conservation is why crystal momentum is not a true momentum.

Examples include electron-lattice potential scattering or an anharmonic phonon-phonon (or electron-phonon) scattering process, reflecting an electronic state or creating a phonon with a momentum k-vector outside the first Brillouin zone. Umklapp scattering is one process limiting the thermal conductivity in crystalline materials, the others being phonon scattering on crystal defects and at the surface of the sample.

The left panel of Figure 1 schematically shows the possible scattering processes of two incoming phonons with wave-vectors (k-vectors) k1 and k2 (red) creating one outgoing phonon with a wave vector k3 (blue). As long as the sum of k1 and k2 stay inside the first Brillouin zone (grey squares), k3 is the sum of the former two, thus conserving phonon momentum. This process is called normal scattering (N-process).

With increasing phonon momentum and thus larger wave vectors k1 and k2, their sum might point outside the first Brillouin zone (k'3). As shown in the right panel of Figure 1, k-vectors outside the first Brillouin zone are physically equivalent to vectors inside it and can be mathematically transformed into each other by the addition of a reciprocal lattice vector G.  These processes are called Umklapp scattering and change the total phonon momentum.

Umklapp scattering is the dominant process for electrical resistivity at low temperatures for low defect crystals (as opposed to phonon-electron scattering, which dominates at high temperatures, and high-defect lattices which lead to scattering at any temperature.) 

Umklapp scattering is the dominant process for thermal resistivity at high temperatures for low defect crystals. The thermal conductivity for an insulating crystal where the U-processes are dominant has 1/T dependence.

History 
The name derives from the German word umklappen (to turn over). Rudolf Peierls, in his autobiography Bird of Passage states he was the originator of this phrase and coined it during his 1929 crystal lattice studies under the tutelage of Wolfgang Pauli. Peierls wrote, "…I used the German term Umklapp (flip-over) and this rather ugly word has remained in use…".

The term Umklapp appears in the 1920 paper of Wilhelm Lenz's seed paper of the Ising model.

See also
 Sampling theorem

References

Scattering
Finger joint. A finger joint, also known as a comb joint, is a woodworking joint made by cutting a set of complementary, interlocking profiles in two pieces of wood, which are then glued. The cross-section of the joint resembles the interlocking of fingers between two hands, hence the name "finger joint".  The sides of each profile increases the surface area for gluing, resulting in a strong bond, stronger than a butt joint but not very visually appealing. Finger joints are regularly confused with box joints, which are used for corners of boxes or box-like constructions.

Creation
Finger joints are generally created by using identical profiles for both pieces.  They are made complementary by rotation or translation of the tool with respect to the workpiece.  Typically a finger router bit is used, but spindle moulders can also be used.  Manual cutting of finger joints is time-consuming and error prone hence rarely done except in craft pieces.

Applications
A tapered or scarfed finger joint is the most common joint used to form long pieces of lumber from solid boards; the result is finger-jointed lumber.

The finger joint can also be valuable when creating baseboards, moulding or trim, and can be used in such things as floor boards, and door construction.

See also 
 Dovetail joint
 Miter joint
 Box joint
 Lap joint

References
https://www.nrcan.gc.ca/forests

Joinery

de:Holzverbindung#Zinkung_und_Gratung
PC Answers. PC Answers was a computer magazine published in the United Kingdom by Future plc.

It was notable for its focus on the technical side of computing.  It ran several series of articles on overclocking, a "Danger! Don't Try This At Home!" section which reviewed hardware projects such as the Stone Soupercomputer and Tomohiro Kawada's dual Celeron PC. Its "Extreme Customisation" series reviewed alternate shells for Microsoft Windows such as Litestep and desktop enhancements such as Stardock's WindowBlinds.

PC Answers was reported to cease publication in September 2010. The title's last issue appeared in October 2010.

References

External links
 Official UK site

Future plc
1994 establishments in the United Kingdom
2010 disestablishments in the United Kingdom
Defunct computer magazines published in the United Kingdom
Magazines established in 1994
Magazines disestablished in 2010
Longitudinal engine. In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, from front to back. 
See also: transverse engine

Use
This type of motor is usually used for rear-wheel drive cars, except for some Audi, SAAB, the Oldsmobile Toronado, and the 1967 Cadillac Eldorado equipped with longitudinal engines in front wheel drive. In front-wheel drive cars a transverse engine is usually used. Trucks often have longitudinal engines with rear-wheel drive. 

For motorcycles, the use of a particular type depends on the drive: in the case of a chain or belt drive a transverse engine is usually used, and with shaft drives a longitudinal engine. Longitudinal engines in motorcycles do have one disadvantage: the "tipping point" of the crankshaft tilts along the entire motorcycle to a greater or lesser degree when accelerating. This is partly resolved by having other components, such as the generator and the gearbox, rotate in the opposite direction to the crankshaft.

Most larger, "premium" vehicles use the longitudinal engine orientation in combination with rear wheel drive, because powerful engines such as the inline-6 and 90° big-bore V8 are usually too long to fit in a FF transverse engine bay. By contrast most mainstream modern vehicles use front wheel drive along with a transverse engine arrangement since they are usually equipped with inline-4 or V6 engines. While both layouts can be adapted for all-wheel drive, the longitudinal engine orientation has a more balanced weight distribution leading to superior handling characteristics, but is less efficient in terms of packaging and interior space.

Cars with longitudinal engines usually have a smaller minimum turning circle than those with transverse engines.  This is because there is more space to the sides of the engine, allowing deeper wheel arches so the front wheels are able to turn through a greater angle.

In the late 1960s, GM divisions Oldsmobile and Cadillac had front-wheel drive models Toronado and Eldorado respectively, with a longitudinal V8 engine and an integrated automatic transmission and differential unit powering the front wheels.  Honda and Toyota also offered front-wheel drive cars with longitudinal engines, namely Honda Vigor, Acura/Honda Legend/RL, and Toyota Tercel.

Common types
This is a list of typical examples of types of engines which can be placed in motor vehicles:
 In-line or straight engine – where two, three, four, five, six, and even eight cylinders are placed in a single plane.
 V engine – where two, four, six, eight, ten, twelve, or even sixteen cylinders are placed in two separate planes, looking like a "V" when viewed from the end of the crankshaft.
 Flat or boxer engine – where two, four, six or more cylinders are arranged in two diametrically horizontally opposed planes.
 W engine – where two (narrow angle) vee engines are siamesed together (within 180°), where at eight, twelve or sixteen cylinders are arranged in four separate planes.

References

Engine technology
Automotive technologies
PTF. Palomar Transient Factory, an astronomical survey program 
 Pedotransfer function, a concept used in soil science
 Phase transfer function, used for the optics of an imaging system

Computing
 Program temporary fix (PTF file format), an IBM locution to designate bug fixes
 PlayStation Portable, a file extension for the PlayStation Portable systems
 Pro Tools 7 up to Pro Tools 9 session (project) file

Other
 Pat Tillman Foundation, a scholarship and leadership nonprofit serving U.S. military veterans and military spouses
 Peter Tatchell Foundation, a British human rights organization
 Police Task Force, former name of the Police Tactical Unit of the Singapore Police Force 
 Präzisionsteilefertigung Steffen Pfüller, a producer of high-tech precision parts and assemblies
 PTF boat a type of Patrol Craft used in Vietnam
Derek Burney Jr.. Derek Burney is the former president of Corel Corporation.

In 1988, at the age of 26, Burney entered the Computer Science program at Carleton University, spending co-op terms at Nortel and Atomic Energy of Canada Limited (AECL). He began his career with Corel as a developer and, with the help of his mentor Michael Cowpland, rose quickly through the ranks, eventually heading the engineering department and becoming President and Chief executive officer following Cowpland's resignation in 2000.

After taking the company private with Vector Capital, Burney held the position of Chairman until he resigned to join Microsoft in 2004.

Burney is currently corporate vice president of Customer Technical Engagement in Microsoft's Worldwide Commercial Business.

Burney's father, Derek Burney Sr., is a noted Canadian businessperson and diplomat.

References

External links
 Carleton University alumni profile from 2001

Canadian businesspeople
Carleton University alumni
Year of birth missing (living people)
Living people
Corel
Nortel people
British Rail Class 118. The British Rail Class 118 diesel multiple units were built by the Birmingham Railway Carriage and Wagon Company (BRCW) and introduced from 1960. It was a licence-built version of the British Rail Class 116.

History
BR Derby was inundated with orders for the Class 116, so the work was put out to tender. All Class 118s were built in Birmingham by Birmingham Railway Carriage and Wagon Company.

Originally allocated to the Western Region, the 118 was extensively used in Devon and Cornwall. They were stabled at Laira depot. The 118s survived in service in the region until 1994 when they were replaced by Class 156s.

In its final days, vehicles were allocated to Tyseley depot in Birmingham, and were all withdrawn by the end of 1994. Like most first generation DMUs they were originally BR Green, then plain blue, and finally blue and grey, with a few receiving Network SouthEast livery. One set was painted in all over yellow with advertisements for British Telecom.

A normal formation was three vehicles- a Driving Motor Brake Second (DMBS) which had two BUT engines (Later fitted with Leyland), a driving compartment (cab), 65 second class seats, guards accommodation and luggage/parcels space, a Trailer Composite Lavatory (TCL) which had no engines or driving compartment, but had 22 first class seats, 48 second class seats and a lavatory, and a Driving Motor Second (DMS), which like the DMBS had two engines and a driver's cab, and contained 89 second class seats. Having the 'blue square' multiple working system allowed them to run in formations containing up to 12 cars with most of BR's other DMUs.

Two vehicles were converted to sandite use.

Orders

Preservation

Only one Class 118 vehicle, DMS Number 51321, has been preserved and is at the Battlefield Line. This vehicle has been paired with class 116 DMBS 51131, also based on the railway.

References

Motive Power Recognition: 3 DMUs. Colin J. Marsden
British Railway Pictorial: First Generation DMUs.  Kevin Robertson
British Rail Fleet Survey 8: Diesel Multiple Units- The First Generation.  Brian Haresnape
A Pictorial Record of British Railways Diesel Multiple Units.  Brian Golding

External links

 Battlefield Line website

118
BRCW multiple units
Train-related introductions in 1960
Thouless energy. The Thouless energy is a characteristic energy scale of diffusive disordered conductors. It was first introduced by the Scottish-American physicist David J. Thouless when studying Anderson localization,
as a measure of the sensitivity of energy levels to a change in the boundary conditions of the system. Though being a classical quantity, it has been shown to play an important role in the quantum-mechanical treatment of disordered systems.

It is defined by 
, 
where D is the diffusion constant and L the size of the system, and thereby inversely proportional to the diffusion time 
 
through the system.

References

Mesoscopic physics
Condensed matter physics
Temporal logic of actions. Temporal logic of actions (TLA) is a logic developed by Leslie Lamport, which combines temporal logic with a logic of actions.
It is used to describe behaviours of concurrent and distributed systems. It is the logic underlying the specification language TLA+.

Details 
Statements in the temporal logic of actions are of the form , where A is an action and t contains a subset of the variables appearing in A. An action is an expression containing primed and non-primed variables, such as . The meaning of the non-primed variables is the variable's value in this state. The meaning of primed variables is the variable's value in the next state.
The above expression means the value of x today, plus the value of x tomorrow times the value of y today, equals the value of y tomorrow.

The meaning of  is that either A is valid now, or the variables appearing in t do not change. This allows for stuttering steps, in which none of the program variables change their values.

Specification Languages
There are multiple specification languages that implement Temporal Logic of Actions. Each language has unique features and use cases:

TLA+
TLA+ is the default and most widely used specification language for TLA. It is a mathematical language designed to describe the behavior of concurrent and distributed systems. The specification is written in functional style.
----------------------------- MODULE HourClock -----------------------------
EXTENDS Naturals

VARIABLES hour

Init == hour = 1

Next == hour' = IF hour = 12 THEN 1 ELSE hour + 1

Spec == Init /\ [][Next]_hour
=============================================================================

PlusCal
PlusCal is a high-level algorithm language that translates to TLA+. It allows users to write algorithms in a familiar pseudocode-like syntax, which are then automatically converted into TLA+ specifications. This makes PlusCal ideal for those who prefer to think in terms of algorithms rather than state machines.

----------------------------- MODULE HourClock ----------------------
EXTENDS Naturals

(*--algorithm HourClock {
    variable hour = 1;
    {
        while (TRUE) {
            hour := (hour % 12) + 1;
        }
    }
} --*)

Quint
Quint is another specification language that translates to TLA+. Quint combines the robust theoretical basis of the Temporal Logic of Actions (TLA) with state-of-the-art type checking and development tooling. Unlike PlusCal, the Quint operators and keywords have one-to-one translation to TLA+.

FizzBee
FizzBee is an alternative to TLA+ with higher level specification language using Python like syntax designed to bring formal methods for mainstream software engineers working on distributed systems. While based on Temporal Logic of Actions, it does not translate to or use TLA+ under the hood unlike PlusCal or Quint. 

action Init:
  hour = 1

atomic action Tick:
  # The body of the actions is Starlark (a Python dialect)
  hour = (hour % 12) + 1

See also
 Temporal logic
 PlusCal
 TLA+

References

External links
 
 
 
 
 

Temporal logic
Concurrency (computer science)
10 Gigabit Ethernet Alliance. The 10 Gigabit Ethernet Alliance (10GEA) was an independent (not directly related to Institute of Electrical and Electronics Engineers (IEEE), although working in collaboration with it) organization which aimed to further 10 Gigabit Ethernet development and market acceptance. Founded in February 2000 by a consortium of companies, the organization provided IEEE with technology demonstrations (including, for instance, a May 7, 2002 demonstration in Las Vegas, in which a 200 plus kilometres 10 Gb Ethernet network was deployed, using 10GBASE-LR, 10GBASE-ER, 10GBASE-SR and 10GBASE-LW ports, as well as presenting communication over the IEEE 802.3ae XAUI interface) and specifications. Its efforts bore fruit with the IEEE Standards Association (IEEE-SA) Standards Board's approval in June 2002 of the IEEE 802.3 standard (formulated by the IEEE P802.3ae 10 Gbit/s Ethernet Task Force).

The 10GEA was founded by 3Com, Cisco Systems, Extreme Networks, Intel Corporation, Nortel Networks, Sun Microsystems, and World Wide Packets. Other companies at various times supporting the consortium included: Agilent Technologies Inc., Blaze Network Products, Cable Design Technologies, Corning Inc., Enterasys Networks, Force10 Networks Inc., Foundry Networks Inc., Hitachi Cable Ltd, Infineon Technologies, Ixia, JDS Uniphase, Marvell Technology Group Ltd., Mindspeed, Molex Inc., OFS (part of Lucent), ONI Systems/CIENA, Optillion, PMC-Sierra, Primarion, Quake Technologies (acquired by Applied Micro Circuits Corporation), Spirent Communications, and Velio Communications (later acquired by LSI Corporation).

See also
 Ethernet Alliance

References

External links 
 
 IEEE P802.3ae 10Gb/s Ethernet Task Force
 Collection of archived 10GEA whitepapers

Ethernet
Stagnation temperature. In thermodynamics and fluid mechanics, stagnation temperature is the temperature at a stagnation point in a fluid flow. At a stagnation point, the speed of the fluid is zero and all of the kinetic energy has been converted to internal energy and is added to the local static enthalpy. In both compressible and incompressible fluid flow, the stagnation temperature equals the total temperature at all points on the streamline leading to the stagnation point. See gas dynamics.

Derivation

Adiabatic
Stagnation temperature can be derived from the first law of thermodynamics.  Applying the steady flow energy equation and ignoring the work, heat and gravitational potential energy terms, we have:

where:

 mass-specific stagnation (or total) enthalpy at a stagnation point
 mass-specific static enthalpy at the point of interest along the stagnation streamline
 velocity at the point of interest along the stagnation streamline

Substituting for enthalpy by assuming a constant specific heat capacity at constant pressure () we have:

or

where:

 specific heat capacity at constant pressure
 stagnation (or total) temperature at a stagnation point
 temperature (or static temperature) at the point of interest along the stagnation streamline
 velocity at the point of interest along the stagnation streamline
 Mach number at the point of interest along the stagnation streamline
 Ratio of Specific Heats (), ~1.4 for air at ~300 K

Flow with heat addition

q = Heat per unit mass added into the system

Strictly speaking, enthalpy is a function of both temperature and density. However, invoking the common assumption of a calorically perfect gas, enthalpy can
be converted directly into temperature as given above, which enables one to define a stagnation temperature in terms of the more fundamental property,
stagnation enthalpy.

Stagnation properties (e.g., stagnation temperature, stagnation pressure) are useful in jet engine performance calculations.  In engine operations, stagnation temperature is often called total air temperature.  A bimetallic thermocouple is frequently used to measure stagnation temperature, but allowances for thermal radiation must be made.

Solar thermal collectors
Performance testing of solar thermal collectors utilizes the term stagnation temperature to indicate the maximum achievable collector temperature with a stagnant fluid (no motion), an ambient temperature of 30C, and incident solar radiation of 1000W/m2. The aforementioned figures are 'worst case scenario values' that allow collector designers to plan for potential overheat scenarios in the event of collector system malfunctions.

See also
Stagnation point
Stagnation pressure
Total air temperature

References

Fluid dynamics