omniomni/omni-engineering huggingface dataset:
List of HDL simulators. HDL simulators are software packages that simulate expressions written in one of the hardware description languages, such as VHDL, Verilog, SystemVerilog.

This page is intended to list current and historical HDL simulators, accelerators, emulators, etc.

Proprietary simulators 

Some commercial proprietary simulators (such as ModelSim) are available in student, or evaluation/demo editions. These editions generally have many features disabled, arbitrary limits on simulation design size, but are sometimes offered free of charge.

Free and open-source simulators

Verilog simulators

VHDL simulators

Key

See also
 Verilog
 SystemVerilog
 VHDL
 SystemC
 Waveform viewer

References

Hardware description languages
Electronic design automation software
Electronic circuit verification
HDL simulators
Superadditive developer. Photographic developer solutions may contain more than one developing agents, such as Metol and hydroquinone, or Phenidone and hydroquinone. This is because they work together to a synergistic effect, called superadditive development.

Definition

Superadditive development commonly means that the mathematical superadditive inequality holds for the rate of development. That is, the rate of development of the two (or more) agents together is greater than the sum of the rate of each agent used alone.

There are cases that density superadditivity holds without rate superadditivity. Note that the term superadditive development is usually not used to mean density superadditivity: the image density obtained from the combined agents is greater than the sum of the density from each agent used alone.

Mechanism
There were several historical theories about the mechanism of superadditive development, until G. I. P. Levenson elucidated the regeneration mechanism. It is useful to review modern treatment of the development mechanism described as an electrode process.

Of the two developing agents that are superadditive, the following is usually the case:

 Agent 1 has lower reduction potential but much higher adsorption to the silver halide crystals.
 Agent 2 has higher reduction potential but much poorer adsorption to the silver halide crystals.

Agent 1 is the developer that reduces the silver halide crystals. Oxidation product of Agent 1 is reduced back to the original form by Agent 2. In other words, the ultimate source of the electrons used to develop image comes from Agent 2. For this reason, in modern convention, Agent 1 is usually called electron transferring agent or ETA. Agent 2 is usually called the main developing agent.

As obvious from the above mechanism, developing agent with very stable semiquinone radical form (the first oxidized form of the ETA) tends to make more superadditive combination. Also obvious from the above mechanism is that Agent 1 has to have an intermediate reduction potential in the developer solution between the Fermi energy level of silver (the developing image silver) 
and the reduction potential of Agent 2 in the developer solution.

Examples of Agent 1 include: Phenidone, Dimezone S, Metol, p-aminophenol, glycin, Eikonogen. These agents have nitrogen atoms that give strong affinity to silver halide (argentophilic) as well as hydrophobic end, effectively acting as a surfactant between the developer solution and silver halide crystals.

Examples of Agent 2 include: hydroquinone and ascorbic acid. These agents have stronger reduction potentials than those of Agent 1 group, but they have very poor adsorption on silver halide crystals, due to lack of argentophilic end.

However, there are many developer combinations that exhibit superadditive development.

Hydroquinone developers

References

Science of photography
Photographic processes
4+1 architectural view model. 4+1 is a view model used for "describing the architecture of software-intensive systems, based on the use of multiple, concurrent views". The views are used to describe the system from the viewpoint of different stakeholders, such as end-users, developers, system engineers, and project managers. The four views of the model are logical, development, process, and physical view. In addition, selected use cases or scenarios are used to illustrate the architecture serving as the 'plus one' view. Hence, the model contains 4+1 views:

 Logical view: The logical view is concerned with the functionality that the system provides to end-users. UML diagrams are used to represent the logical view, and include class diagrams, and state diagrams.
 Process view: The process view deals with the dynamic aspects of the system, explains the system processes and how they communicate, and focuses on the run time behavior of the system. The process view addresses concurrency, distribution, integrator, performance, and scalability, etc. UML diagrams to represent process view include the sequence diagram, communication diagram, activity diagram.
 Development view: The development view (aka the implementation view) illustrates a system from a programmer's perspective and is concerned with software management. UML Diagrams used to represent the development view include the Package diagram and the Component diagram.
 Physical view: The physical view (aka the deployment view) depicts the system from a system engineer's point of view. It is concerned with the topology of software components on the physical layer as well as the physical connections between these components. UML diagrams used to represent the physical view include the deployment diagram.
 Scenarios: The description of an architecture is illustrated using a small set of use cases, or scenarios, which become a fifth view. The scenarios describe sequences of interactions between objects and between processes. They are used to identify architectural elements and to illustrate and validate the architecture design. They also serve as a starting point for tests of an architecture prototype. This view is also known as the use case view.

The 4+1 view model is generic and is not restricted to any notation, tool or design method. Quoting Kruchten,

See also 
 View model
C4 model
ISO/IEC 42010

References 

Software architecture
Yellow Cross (chemical warfare). Yellow Cross (Gelbkreuz) is a World War I chemical warfare agent usually based on mustard gas (sulfur mustard, HS, Yperite, Lost).

The original Gelbkreuz was a composition of 80–90% of sulfur mustard and 10–20% of tetrachloromethane or chlorobenzene as a solvent which lowered its viscosity and acted as an antifreeze, or, alternatively, 80% sulfur mustard, 10% bis(chloromethyl) ether, and 10% tetrachloromethane. A later formulation, Gelbkreuz 1, was a mixture of 40% ethyldichloroarsine, 40% ethyldibromoarsine, and 20% of bis(chloromethyl) ether. In some cases nitrobenzene was used to mask the material's characteristic odour. French "ypérite no.20" was a similar mixture of 80% sulfur mustard and 20% tetrachloromethane.

Yellow Cross is also a generic World War I German marking for artillery shells with chemical payload affecting the skin.

See also 
 Green Cross (chemical warfare)
 Blue Cross (chemical warfare)
 White Cross (chemical warfare)

References

Blister agents
World War I chemical weapons
White Cross (chemical warfare). White Cross (Weiẞkreuz) is a World War I chemical warfare agent consisting of one or more lachrymatory agents: bromoacetone (BA), bromobenzyl cyanide (Camite), bromomethyl ethyl ketone (homomartonite, Bn-stoff), chloroacetone (Tonite, A-stoff), ethyl bromoacetate, and/or xylyl bromide.

During World War I, White Cross was also a generic code name used by the German Army for artillery shells with an irritant chemical payload affecting the eyes and mucous membranes.

See also 
 Blue Cross (chemical warfare)
 Green Cross (chemical warfare)
 Yellow Cross (chemical warfare)

References 

Lachrymatory agents
World War I chemical weapons
William Holding Echols. William Holding Echols VI (December 2, 1859 – September 25, 1934), generally called "Reddy" Echols, was a professor of mathematics at the University of Virginia.  The Echols Scholars Program is named in his honor.
William Echols was the son of the fifth of the same name who was a Major in Confederate States of America. 

Echols attended the university as an undergraduate and received his Bachelor of Science and a civil engineering degree from the university in 1882. Following his graduation, he became an engineering professor, and later director, of the Missouri School of Mines (now Missouri University of Science and Technology). He returned to UVA as adjunct professor of mathematics in 1891, teaching mechanical engineering and serving as the building and grounds supervisor.

On October 27, 1895, a fire started in the Rotunda Annex on the UVA grounds.  Echols, in a dramatic attempt to save the Rotunda, attempted to use dynamite to destroy the roofed portico that connected the Annex and the Rotunda and keep the fire from spreading to the historic building.  Unfortunately, despite his attempt to hurl 50 pounds of dynamite to the portico from atop the Rotunda dome, the portico held, the fire spread more rapidly than before, and the Rotunda was gutted by the blaze.

In later years, Echols authored a text on elementary calculus. He remained active in University life and was a member of Eli Banana. He died of a heart attack in his home on the East Lawn in 1934 and is buried in the university cemetery.

Selected publications
On a general formula for the expansion of functions in series. Bull. Amer. Math. Soc. 2 (1893) 135–144. 
Wronski's expansion. Bull. Amer. Math. Soc. 2 (1893) 178–184.

References

1859 births
1934 deaths
Burials at the University of Virginia Cemetery
Missouri University of Science and Technology faculty
University of Virginia faculty
University of Virginia School of Engineering and Applied Science alumni
Per Håkan Sundell. Per Håkan Sundell (born 1968, Sweden) is a programmer and computer scientist with roots in the scene and early computer enthusiasts of the eighties, when he was known as PHS of CCS (Computerbrains Cracking Service).

Biography 
Håkan currently holds a Ph.D. in computing science (2004) from Chalmers University of Technology and works as associate professor in software engineering at the School of Business and Informatics, University College of Borås, Sweden.

Creations 
Time Zero (1985) - together with Ale Rivinoja
CCS-Mon (1986)
PlaySID (1990) - together with Ron Birk
CCS64 (1995)
NOBLE (2002) - together with Philippas Tsigas

References 

 Prize for best research article News article with interview at Chalmers University of Technology.
 Chalmersteknologi i nya Java News article with interview at Chalmers University of Technology.
 Den främsta C64-emulatorn är svensk - M3 News article with interview in the magazine called M3.
 Mobiler och handdatorer ger gamla datorspel ett andra liv News article with interview in the scientific news paper Ny Teknik.

External links
CCS64 The homepage of the CCS64 Emulator.
Dr. Håkan Sundell Research homepage.

1968 births
Chalmers University of Technology alumni
Commodore people
Living people
Swedish computer scientists
Swedish computer programmers
University of Gothenburg alumni
Volta River Authority. The Volta River Authority (VRA) is the main generator and supplier of electricity in Ghana. They are also responsible for the maintenance of the hydro power supply plant.

Establishment 
The VRA was established by the Volta River Development Act, Act 46 of the Republic of Ghana on 26 April 1961.

The main purpose of the VRA is to generate and supply electricity for Ghana's needs. It is also responsible for managing the environmental impact of the creation of the Volta Lake on the towns and people bordering the lake. The VRA maintains a national energy supply grid and although it started with hydroelectric power, it is now branching into other types of energy such as thermal energy. The company represents Ghana in the West African Power Pool.

Power generation 
Akosombo Hydroelectric Project
Kpong Dam
Takoradi Power Station
 Navrongo Solar Power Plant
 Tema Power Station
 Kpone Power Station

Other projects 
Schools
Health services
Environmental and Resettlement activities

Subsidiary companies 
Volta Hotel
Volta Lake Transport Company (VLTC)
 Kpong Farms
 Northern Electricity Distribution Company (NEDCo)
 VRA Property Holding Company (VRA PROPCo)
 VRA Health Services Limited
 VRA Schools

See also 

Electricity sector in Ghana
Ministry of Energy (Ghana)
Osagyefo Barge

References

External links 
Official website

 
Government-owned companies of Ghana
Electric power companies of Ghana
1961 establishments in Ghana
Energy companies established in 1961
Cobalt(II) naphthenate. Cobalt(II) naphthenate is a mixture of cobalt(II) derivatives of naphthenic acids.  These coordination complexes are widely used as oil drying agents for the autoxidative crosslinking of drying oils. Metal naphthenates are not well defined in conventional chemical sense that they are mixtures. They are widely employed catalysts because they are soluble in the nonpolar substrates, such as the alkyd resins or linseed oil. The fact that naphthenates are mixtures helps to confer high solubility. A second virtue of these species is their low cost. A well-defined compound that exhibits many of the properties of cobalt naphthenate is the cobalt(II) complex of 2-ethylhexanoic acid.  Often in technical literature, naphthenates are described as salts, but they are probably also non-ionic coordination complexes with structures similar to basic zinc acetate.

The catalytic properties of cobalt(II) naphthenates are similar to those of related compounds containing manganese and iron.  Such species are sometimes classified as active driers.  Active driers are catalysts that feature redox-active metal centers.  Such centers promote redox reactions with hydroperoxide-containing intermediates.

Toxicity and safety
Cobalt Naphthenate is a moderately toxic substance which can cause a range of acute and chronic conditions, and it is also a carcinogen. It is most commonly used diluted in mineral spirit or mineral oil. Safety equipment must be used to avoid eye and skin contact. The pure compound has a high vapor density of 3.9 (air = 1), and a low vapor pressure of 1 mm Hg at 25 °C (77 °F).

References

Salts of carboxylic acids
Cobalt(II) compounds
Cortland Street Drawbridge. The Cortland Street Drawbridge (originally known as the Clybourn Place drawbridge) over the Chicago River is the original Chicago-style fixed-trunnion bascule bridge, designed by John Ericson and Edward Wilmann. When it opened in 1902, on Chicago's north side, it was the first such bridge built in the United States. The bridge was a major advance in American movable bridge engineering, and was the prototype for over 50 additional bridges in Chicago alone. The bridge was designated as an ASCE Civil Engineering Landmark in 1981, and a Chicago Landmark in 1991.

Design
This is the bridge type for which Chicago engineers are most well-known. The trunnion bascule has two bridge leaves with pivots on the opposing riverbanks and are raised on large trunnion bearings by large counterweights which offset the weight of the leaves. They take their names from the French word bascule, meaning seesaw, and the counterweights. Unlike most of the subsequent bascule bridges of Chicago, the gear rack that moves this bridge is visible above the roadway, on the curved arcs at each end of the superstructure.

History
The bridge was built under the supervision of Mayor Carter Harrison, Jr., and Frederick W. Blocki, the Commissioner of Public Works.

This is the second bridge built on this site, which replaced a swing bridge with a mid-river pier supporting the swing span. The current bridge eliminated the need for the mid-river pier, allowing more room in the shipping channel.

While the machinery of the current bridge is intact, the bridge is no longer operable and the leaves are clamped together.

The bridge was traversed by streetcars of Line 73-Armitage Avenue, in addition to other traffic until February 25, 1951. The following day the bridge was temporarily closed for repairs and the Chicago Transit Authority (CTA) substituted buses for streetcars east of the bridge, subsequently abandoning the remainder of the Armitage Avenue streetcar line in June. Electric trolley buses also crossed the bridge, starting on February 1, 1953, when CTA replaced the motor buses on route 73. Trolley buses operated until October 15, 1966, when the agency converted the route to diesel buses.

The Cortland Street Bridge is currently used for two-way vehicle traffic, pedestrian, and bicycle traffic.

See also
List of bridges documented by the Historic American Engineering Record in Illinois

References

External links

Bridges in Chicago
Bridges completed in 1902
Bascule bridges in Illinois
Historic American Engineering Record in Illinois
Historic Civil Engineering Landmarks
Chicago Landmarks
Road bridges in Illinois
Steel bridges in the United States
FLUKA. FLUKA (FLUktuierende KAskade) is a fully integrated Monte Carlo simulation package for the interaction and transport of particles and nuclei in matter.
FLUKA has many applications in particle physics, high energy experimental physics and engineering, shielding, detector and telescope design, cosmic ray studies, dosimetry, medical physics, radiobiology. A recent line of development concerns hadron therapy.

It is the standard tool used in radiation protection studies in the CERN particle accelerator laboratory.
FLUKA software code is used by Epcard, which is a software program for simulating radiation exposure on airline flights.

Comparison with other codes 

MCNPX is slower than FLUKA.

Geant4 is slower than FLUKA.

References

Further reading

External links 
 Official site of FLUKA collaboration
 FLUKA on the CERN bulletin
 Physics software used to fight cancer

Fortran software
Physics software
Monte Carlo molecular modelling software
Science software for Linux
Linux-only proprietary software
CERN software
Monte Carlo particle physics software
Proprietary commercial software for Linux
Autofeather. Autofeather is a feature of the engines on some turboprop and piston engine aircraft. When the power being produced by the engine drops to the point where it is not contributing to thrust, the propeller will go into a feathered mode to reduce drag.

The auto feather system also allows pilots to reduce the drag of the propellers during an engine failure, therefore, allowing the plane to glide for a longer period of time.

An automatic feathering system was first introduced on the Martin 4-0-4 aircraft, a piston engine airplane. The system was designed to automatically feather an engine that failed during takeoff or initial climb.
It is not used during cruise.

References

Aircraft engines
Commodity cell. A commodity cell is a type of battery made in large volumes for use by original equipment manufacturers. For example, commodity cells are used in laptops and cell phones, as the energy storage element in its batteries.

Production
The auto industry battery consortium, USABC, set about to invent automotive batteries made from specialty cells for cars.

Tesla Motors uses commodity cells to make their automotive batteries. 

Practically all commodity cells today are made in Asia – mainly Japan, South Korea, and China. There is no significant production anywhere in the US.  A modern lithium ion cell plant – such as those in Japan – is a highly automated affair with very low labor content.

See also 
 List of battery types

References
 http://www.finance.senate.gov/imo/media/doc/050107testme.pdf

External links
 Tesla Motors
 http://www.finance.senate.gov/imo/media/doc/050107testme.pdf

Battery applications
Protechnik. Protechnik was a front company established on 24 June 1987 by the South African Defence Force to perform quality assurance testing of chemical protective materials and equipment within a covert operation known as Project Coast. 

Founded by Dr. Jan Lourens, a bio-engineering consultant at Roodeplaat Research Laboratories,  as Systems Research and Development (SRD), with funding provided by the Medical arm of the SADF. Protechnik's shareholders would include Medchem Consolidated Investments (MCI), WPW Investments (a firm belonging to Wouter Basson) the Luxembourg-based Charburn Enterprises. According to testimony provided in the Wouter Basson trial, Protechnik was involved in reverse engineering Chemical Agent Monitors.

The company is now a subsidiary of Armscor.

Other SADF front organisations
 Badger Arms
 Biocon (South Africa)
 Civil Cooperation Bureau
 Delta G Scientific Company
 Electronic Magnetic Logistical Component
 Executive Outcomes
 Geo International Trading
 Infladel
 Jeugkrag
 Lema (company)
 Military Technical Services
 Roodeplaat Research Laboratories
 Veterans for Victory

References

Defence companies of South Africa
Chemical companies of South Africa
Chemical warfare
South African companies established in 1987
South Africa and weapons of mass destruction
Carriage Works, Bristol. The Carriage Works () are in Stokes Croft, Bristol, England.

History

The Carriage Works was built in 1862 by Edward William Godwin from Pennant stone with Bath stone dressings. It replaced an earlier Coach & Harness Manufactory, owned by T&J. Perry's, established in 1804. The new building has round arched arcades above double width segmental arches. The ground-floor arches were originally open for access by John Perry and Sons' carriages. In 1844 Thomas and John Perry paid £3 per year to rent the site. By the beginning of the 20th century Perry's had modernised from horse carriages to include the manufacture of cars at the site. From 1913 until 1960s the building was used to process rubber by the Anderson's Bristol Rubber Co. Ltd. In the 1960 it was home to Regional Pools Promotions a membership scheme which gave prizes and raised money for charity, and later moved next door to Westmoreland House.

The building has been designated by English Heritage as a grade II* listed building. The building, which is an example of the Bristol Byzantine style, is on the English Heritage Buildings at Risk Register and described as being in very bad condition.

In September 2011 the Carriageworks Action Group was launched to develop community ideas for the future of the building, the neighbouring Westmoreland House and the land behind.  The Action Group is made up of local residents, organisations and businesses, supported by Bristol City Council, and proposes to write a 'community vision' for the site.

In June 2013 a housing association, Knightstone Housing, was named as the preferred developer. In 2015 a planning application was made to Bristol City Council by Fifth Capital to develop the site for a mixed use scheme including 112 homes and designed by Assael Architecture. This was approved in October 2015 despite concerns about the lack of affordable housing included in the scheme.

Demolition of the bulk of The Carriage Works, and the adjacent Westmoreland House began on 21 November 2018. The facade of the building has been retained.

See also
 Grade II* listed buildings in Bristol
 Westmoreland House

References

External links

Carriageworks Action Group

Grade II* listed buildings in Bristol
Industrial buildings completed in 1862
Structures on the Heritage at Risk register
Byzantine Revival architecture in the United Kingdom
1862 establishments in England
Grade II* listed industrial buildings
Buildings and structures demolished in 2018
Demolished buildings and structures in Bristol