omniomni/omni-engineering huggingface dataset:
Alexander Stepanov. Alexander Alexandrovich Stepanov (; born November 16, 1950, Moscow) is a Russian-American computer programmer, best known as an advocate of generic programming and as the primary designer and implementer of the C++ Standard Template Library, which he started to develop around 1992 while employed at HP Labs. He had earlier been working for Bell Labs close to Andrew Koenig and tried to convince Bjarne Stroustrup to introduce something like Ada generics in C++. He is credited with the notion of concept. 

He is the author (with Paul McJones) of Elements of Programming, a book that grew out of a "Foundations of Programming" course that Stepanov taught at Adobe Systems (while employed there).  He is also the author (with Daniel E. Rose) of From Mathematics to Generic Programming.

He retired in January 2016 from A9.com.

Standard Template Library and generic programming
Alexander Stepanov is an advocate of generic programming. Although David Musser had already developed and advocated some aspects of generic programming by 1971, it was limited to a rather specialized area of software development (computer algebra).

Stepanov recognized the full potential for generic programming and persuaded his then-colleagues at General Electric Research and Development (including, primarily, David Musser and Deepak Kapur) that generic programming should be pursued as a comprehensive basis for software development. At the time there was no real support in any programming language for generic programming.

The first major language to provide such support was Ada, with its generic units feature. By 1987 Stepanov and Musser had developed and published an Ada library for list processing that embodied the results of much of their research on generic programming. However, Ada had not achieved much acceptance outside the defense industry and C++ seemed more likely to become widely used and provide good support for generic programming even though the language was relatively immature. Another reason for turning to C++, which Stepanov recognized early on, was that the C/C++ model of computation (which allows very flexible access to storage via pointers) is crucial to achieving generality without losing efficiency.
It eventually led to the development of the Standard Template Library of C++.

See also
 Object-oriented programming criticism

References

Further reading

External links

 Collected Papers of Alexander A. Stepanov
 An interview of Stepanov, from STLport, 1997 
 Another interview, from Dr. Dobbs, March 1995
 Range Partition Adapters A STL-based multi-threaded library, inspired from an article of Alexander Stepanov.
 An interview, by Andrew Binstock, with Alexander Stepanov and Paul McJones on Elements of Programming.
 A9 Video lectures by Alexander Stepanov.

C++ people
1950 births
Living people
Scientists from Moscow
Russian computer programmers
Cut and fill. In earthmoving, cut and fill is the process of constructing a railway, road or canal whereby the amount of material from cuts roughly matches the amount of fill needed to make nearby embankments to minimize the amount of construction labor.

Overview

Cut sections of roadway or rail are areas where the roadway has a lower elevation than the surrounding terrain. Fill sections are elevated sections of a roadway or trackbed. Cut and fill takes material from cut excavations and uses this to make fill sections. It costs resources to excavate material, relocate it, and to compact and otherwise prepare the filled sections. The technique aims to minimise the effort of relocating excavated material while also taking into account other constraints such as maintaining a specified grade over the route.

Other considerations

In addition to minimising construction cost, other factors influence the placement of cut or filled sections.

For example, air pollutants can concentrate in the valleys created by the cut section. Conversely, noise pollution is mitigated by cut sections since an effective blockage of line-of-sight sound propagation is created by the depressed roadway design.

The environmental effects of fill sections are typically favorable with respect to air pollution dispersal, but in respect to sound propagation, exposure of nearby residents is generally increased, since sound walls and other forms of sound path blockage are less effective in this geometry.

The reasons for creating fills include the reduction of grade along a route or the elevation of the route above water, swampy ground, or areas where snow drifts frequently collect. Fills can also be used to cover tree stumps, rocks, or unstable soil, in which case material with a higher bearing capacity is placed on top of the obstacle in order to carry the weight of the roadway or railway and reduce differential settlement.

History
The practice of cut-and-fill was widely utilized to construct tracks along rolling terrain across the British Isles. It was later applied in the construction of new dwellings for returning veterans in Ireland at the end of World War II. This application was developed by Irish railway engineer Lachlan J. Boland, who saw the benefits of introducing railway practices to residential construction.

Software 
A number of software products are available for calculating cut and fill. A simple approach involves defining different earthworks features in a computer program and then adjusting elevations manually to calculate the optimal cut and fill. More sophisticated software is able to automatically balance cut and fill while also considering the materials. Software that can do this falls under the broad category of earthworks estimation software.

See also 

 Cut-and-cover
 Fill dirt
 Regrading
 Trench

References

Environmental engineering
Rail infrastructure
Road cuttings
Building engineering
Comp Air 7. The Comp Air 7 is an American piston or turboprop-powered light civil utility aircraft manufactured in kit form by Comp Air. It is configured as a conventional high-wing monoplane with tailwheel undercarriage.

The company website does not list it as being in production in 2022.

Operational history
By the fall of 2007 70 Comp Air 7s and 25 Comp Air 7SLs had been completed and were flying.

Variants
Comp Air 7
Piston-powered aircraft typically equipped with a Lycoming IO-540 piston engine of 290 hp
Comp Air 7SLX
Turbine powered aircraft equipped typically with a Walter M601 turboprop of 660 shp

Specifications (typical Comp Air 7SLX)

References

External links

Official website archives on Archive.org

7
Homebuilt aircraft
1990s United States civil utility aircraft
High-wing aircraft
Single-engined tractor aircraft
Single-engined turboprop aircraft
Rotary compression pump. A rotary compression pump works in cycles. Over each cycle a volume is created in contact with the chamber where pressure is to be lowered. By random motion, molecules from the vacuum chamber pass into the volume created by the pump. This volume is then cut off from the chamber and compressed in contact with a one way valve. If the volume is compressed enough some of the molecules will pass through the valve.

Performance
The maximum efficiency of a rotary compression pump is the ratio between the volume in contact with the vacuum and the smallest contracted volume in contact with the valve. If the ratio is 1:1000 and the pump is exhausting to atmospheric pressure, the highest achievable vacuum is 1/1000 of atmospheric pressure. This corresponds to 0.76 Torr or 101.3 Pa. This limitation makes rotary compression pumps very hard to construct if lower pressures than about 1 Torr is to be achieved. The simplicity of the process makes the rotary compression pump cheap and it is widely used as a low vacuum pump, or a backing pump to a diffusion pump or turbomolecular pump.

See also
 Rotary vane pump

References

Pumps
Coleco Gemini. The Coleco Gemini is an Atari 2600 clone manufactured by Coleco Industries, Inc. in 1983.

Technical specifications
 Processor: 8-bit 6507
 CPU speed: 1.19 MHz
 RAM: 128 bytes
 Resolution: 160x200, 128 colors

History
In 1982, Coleco released Expansion Module #1 for its ColecoVision video game system. With a custom-made clone of the Atari 2600 TIA chip and off-the-shelf components, the module enabled the ColecoVision to be compatible with Atari 2600 software. Later that year, Atari, Inc. sued Coleco for patent infringement, and the companies wound up settling out of court, with Coleco becoming a licensee of Atari's patents.

Gemini vs. 2600

The main difference between the Coleco Gemini and the Atari 2600 is the controller design. The Coleco Gemini controllers (dubbed the 'Dual Command') featured an 8-way joystick and a 270-degree paddle on the same controller (the joystick was at the top of the controller, and the paddle was at the bottom of the controller). To play paddle games on the 2600, a Y-connector could be used to connect a joystick and paddles to the controller jack at the same time, rather than physically swapping controllers.

The Gemini was more compact than the large faux-woodgrain or gloss black-trimmed consoles sold by Atari at the time. The Gemini also had a different game included with the system. Atari was including its 1982 version of Pac-Man along with Combat (1977). The Gemini initially came bundled with Coleco's 1982 port of Donkey Kong, but at some point also included Carnival, Mouse Trap and Front Line. Sears also offered a version of the Gemini with both Donkey Kong and Mouse Trap included as separate cartridges.

References

External links

 vidgame.net (archived version of page)
 Video review and tour of the console

1980s toys
Atari 2600 hardware clones
Gemini
Manufacturing Message Specification. Manufacturing Message Specification (MMS) is an international standard (ISO 9506) dealing with messaging systems for transferring real time process data and supervisory control information between networked devices or computer applications. The standard is developed and maintained by the ISO Technical Committee 184 (TC184). MMS defines the following

 A set of standard objects which must exist in every device, on which operations like read, write, event signaling etc. can be executed. Virtual manufacturing device (VMD) is the main object and all other objects like variables, domains, journals, files etc. comes under VMD.
 A set of standard messages exchanged between a client and a server stations for the purpose of monitoring or controlling these objects.
 A set of encoding rules for mapping these messages to bits and bytes when transmitted.

MMS original communication stack 
MMS was standardized in 1990 under two separate standards as
 ISO/IEC 9506-1 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 1: Service Definition
 ISO/IEC 9506-2 (2003): Industrial Automation systems - Manufacturing Message Specification - Part 2: Protocol Specification
This version of MMS used seven layers of OSI network protocols as its communication stack:

MMS stack over TCP/IP 
Because the Open Systems Interconnection protocols are challenging to implement, the original MMS stack never became popular. In 1999, Boeing created a new version of MMS using Internet protocols instead of the bottom four layers of the original stack plus RFC 1006 ("ISO Transport over TCP") in the transport layer. The top three layers use the same OSI protocols as before.

In terms of the seven-layer OSI model, the new MMS stack looks like this:

With the new stack, MMS has become a globally accepted standard.

External links
 MMS Protocol Details
 MMS Overview
 MMS V1 Abstract Syntax
 MMS Protocol Description
 MMS. Presentation by Prof. Dr. H. Kirrmann, ABB Research Center, Baden, Switzerland

ISO standards
Permissible stress design. Permissible stress design is a design philosophy used by mechanical engineers and civil engineers.

The civil designer ensures that the stresses developed in a structure due to service loads do not exceed the elastic limit. This limit is usually determined by ensuring that stresses remain within the limits through the use of factors of safety.

In structural engineering, the permissible stress design approach has generally been replaced internationally by limit state design (also known as ultimate stress design, or in USA, Load and Resistance Factor Design, LRFD) as far as structural engineering is considered, except for some isolated cases.

In USA structural engineering construction, allowable stress design (ASD) has not yet been completely superseded by limit state design except in the case of Suspension bridges, which changed from allowable stress design to limit state design in the 1960s. Wood, steel, and other materials are still frequently designed using allowable stress design, although LRFD is probably more commonly taught in the USA university system.

In mechanical engineering design such as design of pressure equipment, the method uses the actual loads predicted to be experienced in practice to calculate stress and deflection. Such loads may include pressure thrusts and the weight of materials. The predicted stresses and deflections are compared with allowable values that have a "factor" against various failure mechanisms such as leakage, yield, ultimate load prior to plastic failure, buckling, brittle fracture, fatigue, and vibration/harmonic effects. However, the predicted stresses almost always assumes the material is linear elastic. The "factor" is sometimes called a factor of safety, although this is technically incorrect because the factor includes allowance for matters such as local stresses and manufacturing imperfections that are not specifically calculated; exceeding the allowable values is not considered to be good practice (i.e. is not "safe").

The permissible stress method is also known in some national standards as the working stress method because the predicted stresses are the unfactored stresses expected during operation of the equipment (e.g. AS1210, AS3990).

This mechanical engineering approach differs from an ultimate design approach which factors up the predicted loads for comparison with an ultimate failure limit. One method factors up the predicted load, the other method factors down the failure stress.

See also
 Allowable Strength Design
 Building code

References

Civil engineering
Mechanical engineering
Structural engineering
Classical Heisenberg model. In statistical physics, the classical Heisenberg model, developed by Werner Heisenberg, is the  case of the n-vector model, one of the models used  to model ferromagnetism and other phenomena.

Definition
The classical Heisenberg model can be formulated as follows: take a d-dimensional lattice, and place a set of spins of unit length,

,

on each lattice node.

The model is defined through the following Hamiltonian:
 
where
 

is a coupling between spins.

Properties
 The general mathematical formalism used to describe and solve the Heisenberg model and certain generalizations is developed in the article on the Potts model.
 In the continuum limit the Heisenberg model (2) gives the following equation of motion
 
This equation is called the continuous classical Heisenberg ferromagnet equation or, more shortly, the Heisenberg model and is integrable in the sense of soliton theory. It admits several integrable and nonintegrable generalizations like the Landau-Lifshitz equation, the Ishimori equation, and so on.

One dimension
In the case of a long-range interaction, , the thermodynamic limit is well defined if  ; the magnetization remains zero if ; but the magnetization is positive, at a low enough temperature, if   (infrared bounds).
As in any 'nearest-neighbor' n-vector model with free boundary conditions, if the external field is zero, there exists a simple exact solution.

Two dimensions
 In the case of a long-range interaction, , the thermodynamic limit is well defined if ; the magnetization remains zero if ; but the magnetization is positive at a low enough temperature if   (infrared bounds).
 Polyakov has conjectured that, as opposed to the classical XY model, there is no dipole phase for any ; namely, at non-zero temperatures the correlations cluster exponentially fast.

Three and higher dimensions
Independently of the range of the interaction, at a low enough temperature the magnetization is positive.

Conjecturally, in each of the low temperature  extremal states the truncated correlations decay algebraically.

See also
 Heisenberg model (quantum)
 Ising model
 Classical XY model
 Magnetism
 Ferromagnetism
 Landau–Lifshitz equation
 Ishimori equation

References

External links
 Absence of Ferromagnetism or Antiferromagnetism in One- or Two-Dimensional Isotropic Heisenberg Models 
  The Heisenberg Model - a Bibliography
  Monte-Carlo simulation of the Heisenberg, XY and Ising models with 3D graphics (requires WebGL compatible browser)

Magnetic ordering
Spin models
Lattice models
Werner Heisenberg
Latten. Historically, the term "latten" referred loosely to the copper alloys such as brass
or bronze
that appeared in the Middle Ages and through to the late-18th and early-19th centuries. Such alloys were used for monumental brasses, in decorative effects on borders, rivets or other details of metalwork (particularly armour), in livery and pilgrim badges or funerary effigies. Latten commonly contained varying amounts of copper, tin, zinc and lead, giving it characteristics of both brass and bronze. Metalworkers commonly formed latten in thin sheets and used it to make church utensils. Brass of this period is made through the calamine brass process, from copper and zinc ore. (Later brass was made with zinc metal from Champion's smelting process and is not generally referred to as "latten".) This calamine brass was generally manufactured as hammered sheet or "battery brass" (hammered by a "battery" of water-powered trip hammers), and cast brass was rare.

"Latten" also refers to a type of tin plating on iron (or possibly some other base metal), which is known as white latten; and black latten refers to laten-brass, which is brass milled into thin plates or sheets.

The term "latten" has also been used, rarely, to refer to lead alloys.

In general, metal in thin sheets is characterised as "latten", e.g. gold latten, and lattens (plural) refers to metal sheets between 1/64" and 1/32" in thickness.

Footnotes

References 
 Random House Webster's Unabridged Dictionary (1998, 2nd edition)
 The Oxford English Dictionary (1989, 2nd edition)
 Webster's Third New International Dictionary (1986) 

Copper alloys
Brass
Knorringite. Knorringite is a mineral species belonging to the garnet group, and forms a series with the species pyrope. It was discovered in 1968 in the Kao kimberlite pipe in the Butha-Buthe District of Lesotho and is named after Oleg Von Knorring, a professor of mineralogy at the University of Leeds in England. 

Synthetic knorringite has the pure endmember formula Mg3Cr2(SiO4)3. As knorringite is a member of the knorringite–pyrope series, natural samples contain variable aluminium in the chromium site.  Knorringite is a greenish blue color with a Mohs scale of mineral hardness of six to seven.  

It occurs as a rare component within ultramafic nodules in kimberlites in association with olivine, enstatite, chrome diopside, chromian pyrope, chromian spinel, ilmenite, perovskite, zircon, diamond, omphacite, rutile, carbonates and micas. It has been reported
from the Red Ledge mine in Nevada County, California in addition to the type location in Lesotho.

Knorringite is a tracer mineral in the search for diamonds in kimberlite pipes.

References

Magnesium minerals
Chromium minerals
Garnet group
Cubic minerals
Minerals in space group 230
William Jolitz. William Frederick Jolitz (February 22, 1957 – March 2, 2022), commonly known as Bill Jolitz, was an American software engineer best known for developing the 386BSD operating system from 1989 to 1994 along with his wife Lynne Jolitz.

Before 386BSD, Bill Jolitz designed the Symmetric 375 with an NSC 16032 (NS32000) CPU running 4.2BSD. His own Symmetric Computer Systems sold them from 1987 until 1988.

Jolitz received his BA in Computer Science from UC Berkeley.

He and his wife resided in Los Gatos, California.

On March 2, 2022, Jolitz died from sarcoma. His death was announced on April 8, 2022, on The Unix Heritage Society (TUHS) mailing list.

References

External links
  - personal website
  article

1957 births
2022 deaths
BSD people
Free software programmers
People from Muskegon, Michigan
University of California, Berkeley alumni
Kernel programmers
Nernst effect. In physics and chemistry, the Nernst effect (also termed the first Nernst–Ettingshausen effect, after Walther Nernst and Albert von Ettingshausen) is a thermoelectric (or thermomagnetic) phenomenon observed when a sample allowing electrical conduction is subjected to a magnetic field and a temperature gradient normal (perpendicular) to each other. An electric field will be induced normal to both.

This effect is quantified by the Nernst coefficient , which is defined to be

where  is the y-component of the electric field that results from the magnetic field's z-component  and the x-component of the temperature gradient .

The reverse process is known as the Ettingshausen effect and also as the second Nernst–Ettingshausen effect.

Physical picture 

Mobile energy carriers (for example conduction-band electrons in a semiconductor) will move along temperature gradients due to statistics and the relationship
between temperature and kinetic energy. If there is a magnetic field transversal to the temperature gradient and the carriers are electrically charged, they experience a force perpendicular to their direction of motion (also the direction of the temperature gradient) and to the magnetic field. Thus, a perpendicular electric field is induced.

Sample types 

The semiconductors exhibit the Nernst effect, as first observed  by T. V. Krylova and Mochan in the Soviet Union in 1955. In metals however, it is almost non-existent.

Superconductors 
Nernst effect appears in the vortex phase of type-II superconductors due to vortex motion. High-temperature superconductors exhibit the Nernst effect both in the superconducting and in the pseudogap phase. Heavy fermion superconductors can show a strong Nernst signal which is likely not due to the vortices.

See also 
 Spin Nernst effect
 Seebeck effect
 Peltier effect
 Hall effect
 Righi–Leduc effect

References 

Walther Nernst
Electrodynamics
Thermoelectricity
Alecto (SPG). The Alecto, initially known as the Harry Hopkins Mk 1 CS, was a self propelled gun developed by the British during World War II.

Development 

In 1942 a project for a 3.75 inch (95 mm) howitzer was started. Two guns were made, and one of these was chosen for test mounting on a Light Tank Mk VIII "Harry Hopkins" chassis. Like the Harry Hopkins, the Alecto had skid steering, which operated by bowing the tracks through lateral movements of the central road wheels. The gun was mounted in an open-topped structure. The first trials were not started until late in 1944. The trials uncovered various problems but by the time these were solved the war in Europe was over. With little perceived potential for use in the war against Japan, the project was ended.

A small number of Alecto Is were completed, some served briefly with the British Army in Germany, arriving in the immediate post-war period  and they equipped the heavy companies of at least the Kings Dragoon Guards operating in the Middle East just after the end of the war

Variants
Mk I
3.75 inch (95 mm), 20 cal howitzer
Mk II
QF 6 pdr gun. Also known as "Alecto Recce"
Mk III
QF 25 pounder gun-howitzer. Prototype partially completed
Mk IV
QF 32-pounder, not built
Alecto Dozer
Some vehicles completed in 1945 with hydraulically operated bulldozer blades

See also
 Light Tank Mk VII Tetrarch
 SP 17pdr, A30 (Avenger)
 SP 17pdr, Valentine (Archer)

Notes

References

 Wheels & Tracks Magazine No. 15

External links

HenkOfHolland 
British Self-propelled guns
Picture of a trialled Alecto by the Swiss Army in 1948 (found by www.wheelsandtracks.com)

Self-propelled artillery of the United Kingdom
Vickers
World War II armoured fighting vehicles of the United Kingdom
Abandoned military projects of the United Kingdom