omniomni/omni-engineering huggingface dataset:
Capacitor-spring analogy. There are several formal analogies that can be made between electricity, which is invisible to the eye, and more familiar physical behaviors, such as the flowing of water or the motion of mechanical devices. 

In the case of capacitance, one analogy to a capacitor in mechanical rectilineal terms is a spring where the compliance of the spring is analogous to the capacitance.  Thus in electrical engineering, a capacitor may be defined as an ideal electrical component which satisfies the equation 

where  = voltage measured at the terminals of the capacitor,  = the capacitance of the capacitor,  = current flowing between the terminals of the capacitor, and  = time.

The equation quoted above has the same form as that describing an ideal massless spring:
, where:

 is the force applied between the two ends of the spring,
 is the stiffness, or spring constant (inverse of compliance) defined as force/displacement, and
 is the speed (or velocity) of one end of the spring, the other end being fixed.

Note that in the electrical case, current (I) is defined as the rate of change of charge (Q) with respect to time:

While in the mechanical case, velocity (v) is defined as the rate of change of displacement (x) with respect to time:

Thus, in this analogy:

 Charge is represented by linear displacement, 
 current is represented by linear velocity, 
 voltage by force. 
 time by time

Also, these analogous relationships apply:

 energy.  Energy stored in a spring is , while energy stored in a capacitor is .
 Electric power.  Here there is an analogy between the mechanical concept of power as the scalar product of velocity and displacement, and the electrical concept that in an AC circuit with sinusoidal excitation, power is the product  where  is the phase angle between  and , measured in RMS terms.
 Electrical resistance (R) is analogous to mechanical viscous drag coefficient (force being proportional to velocity is analogous to Ohm's law - voltage being proportional to current).
 Mass (m) is analogous to inductance (L), since  while . Thus an ideal inductor with inductance L is analogous to a rigid body with mass m.

This analogy of the capacitor forms part of the more comprehensive impedance analogy of mechanical to electrical systems.

See also 
 Hydraulic analogy
 Elastance

References 

H.F. Olson, Dynamical Analogies, Van Nostrand, 2 ed, 1958

Classical mechanics
Electrical analogies
Accumulator (energy). An accumulator is an energy storage device: a device which accepts energy, stores energy, and releases energy as needed. Some accumulators accept energy at a low rate (low power) over a long time interval and deliver the energy at a high rate (high power) over a short time interval. Some accumulators accept energy at a high rate over a short time interval and deliver the energy at a low rate over a longer time interval. Some accumulators typically accept and release energy at comparable rates. Various devices can store thermal energy, mechanical energy, and electrical energy. Energy is usually accepted and delivered in the same form. Some devices store a different form of energy than what they receive and deliver performing energy conversion on the way in and on the way out.

Examples of accumulators include steam accumulators, mainsprings, flywheel energy storage, hydraulic accumulators, rechargeable batteries, capacitors, inductors, compensated pulsed alternators (compulsators), and pumped-storage hydroelectric plants.

In general usage in an electrical context, the word accumulator normally refers to a lead–acid battery.

The London Tower Bridge is operated via an accumulator. The original raising mechanism was powered by pressurised water stored in several hydraulic accumulators. In 1974, the original operating mechanism was largely replaced by a new electro-hydraulic drive system.

See also 
 Rechargeable battery
 Electric vehicle battery
 Battery storage power station

References

Bibliography 

Energy storage

cs:Akumulátor
nl:Accumulator#Accumulatie van energie
ru:Аккумулятор
SCIM. SCIM may refer to:

 Sample Collection for Investigation of Mars, a Mars sample return mission concept
 Service capability interaction manager, a service orchestration component within the IP Multimedia Subsystem architecture
 Smart Common Input Method, an input method for POSIX-style operating systems
 System for Cloud Identity Management: see System for Cross-domain Identity Management
 System for Cross-domain Identity Management, a standard for managing user identities across Internet services
 Spinal cord independence measure, a functional score describing function deficits of patients with a Spinal cord injury
Madelvic Motor Carriage Company. The Madelvic Motor Carriage Company of Granton, Scotland was an early car manufacturing company.

History 

The company was founded by William Peck, Edinburgh's City Astronomer, to develop the emerging technology of electricity. Madelvic produced an 'electric brougham' at their factory in Granton, north Edinburgh, between 1898 and 1900. The vehicle was driven by a three-wheeled front axle unit, comprising motor, batteries and a small central wheel, set behind the axle, which propelled the car. This unit was mounted to the front of a chassis, creating a five-wheeled vehicle, but could also be attached to a horse-drawn carriage. Peck offered public transport using the car, between Granton and Leith as publicity. A more conventional front wheel drive electric vehicle was also briefly produced. However, electric cars were not to be the future, and Madelvic went bankrupt, being taken over by the Kingsburgh Motor Company in 1900.

The original factory building still stands in Granton, and is currently being renovated for residential and office use. It is the oldest surviving car factory in Britain. After Madelvic ceased production, cars were built here by Kingsburgh, and then by the Stirlings Motor Carriages Ltd, who also built buses on the site, exporting some to Australia. In 1925 the buildings were bought by United Wire, and used by them until 2001.

In 2001, the buildings were purchased by the development company Waterfront Edinburgh Limited, a joint venture between City of Edinburgh Council and Scottish Enterprise. Buredi, a joint venture between The Burrell Company and the City of Edinburgh Council, had hoped to redevelop the factory to create a range of residential apartments, townhouses and commercial office space. The renovation was designed by Malcolm Fraser Architects. The building is on the Buildings at Risk Register for Scotland. In July 2024, the Lar Housing Trust submitted plans for the conversion of the production block into 28 townhouses.

Gallery

See also 
 List of car manufacturers of the United Kingdom

References

History of Electric Vehicles
Edinburgh Architecture
British Motor Manufacturers
Granton History Group

External links 

 Edinburgh, Granton, 87 Granton Park Avenue, Madelvic Car Factory, Administration Block on the Canmore database
 Edinburgh, Granton, 87 Granton Park Avenue, Madelvic Car Factory, Production Block on the Canmore database
 Madelvic Motor Factory at the National Transport Trust website

Category B listed buildings in Edinburgh
Defunct motor vehicle manufacturers of Scotland
Electric vehicles introduced in the 19th century
Manufacturing companies based in Edinburgh
Car manufacturers of the United Kingdom
Veteran vehicles
Buildings at Risk Register for Scotland
1898 establishments in Scotland
1900 disestablishments in Scotland
British companies disestablished in 1900
British companies established in 1898
Granton, Edinburgh
National Transport Trust Red Wheel sites
GCC Summit. The GCC Summit was an annual conference for developers of the GNU Compiler Collection and related free software technologies.  The conference was a 3-day event and was held from 2003–2010 in Ottawa, Ontario, Canada with the exception of the 2009 summit, which was held in Montreal, Quebec, Canada. It has been replaced by the GNU Tools Cauldron.

GCC Summit dates
 2003: May 25–27 (proceedings)
 2004: June 2–4 (proceedings)
 2005: June 22–24 (proceedings)
 2006: June 28–30 (proceedings)
 2007: July 18–20 (proceedings)
 2008: June 17–19 (proceedings)
 2009: June 8–10 (proceedings)
 2010: October 25–27 (proceedings, individual papers and slides)

GNU Tools Cauldron
The GCC Summit has been replaced by the GNU Tools Cauldron, a conference held by GNU mainly focused on GNU Compiler Collection (GCC), but also GNU Debugger, GNU Binutils, and others.

See also 

 Summit (meeting)
 Compiler

References

Free-software conferences
Linux conferences
Recurring events established in 2003

External links
GCC Summit 2024
Libre Software Meeting. The Libre Software Meeting (LSM) is an annual free software event originally held in France. The French name of this event is Rencontres mondiales du logiciel libre (RMLL).

Summary 

The Libre Software Meeting takes place each year since 2000, in July. Launched by the French free software users group Association Bordelaise des utilisateurs de logiciels libres (ABUL). More than 1000 people, coming from more than 50 countries, participate each year.

The LSM is a mix of two complementary meetings:
 a developers meeting, free software coders coming to discuss about their projects during the event
 a free software promotion event dedicated to a large audience

Organisation 

The LSM is organized by a team of volunteers, combining local and national free software associations.

Villages 

The village of the associations welcome the visitors with a set of stands presenting local or national associations.

Hosting cities

Logo 

The LSM logo was drawn with Sketch by André Pascual, Linuxgraphic.org co-creator, for the LSM 2001. The choice of the mascot and her name come from the homophony with Armelle (a French feminine first name) and RMLL, as pronounced in English.

See also 
 List of free-software events
 LibrePlanet

External links

Homepage of Libre Software Meeting

Free-software conferences
Linux conferences
Recurring events established in 2000
Index of chemical engineering articles. This is an alphabetical list of articles pertaining specifically to chemical engineering.

A

Absorption -- 
Adsorption -- 
Analytical chemistry --

B

Bioaccumulate  -- 
Biochemical engineering --  
Biochemistry  -- 
Biochemistry topics list --
Bioinformatics  -- 
Biology -- 
Bioprocess Engineering --
Biomolecular engineering --
Bioinformatics --
Biomedical engineering --
Bioseparation --
Biotechnology -- 
Bioreactor --  
Biotite  --

C

Catalysis --
Catalytic cracking --
Catalytic reforming --
Catalytic reaction engineering --
Ceramics -- 
Certified Chartered Chemical Engineers --
Chartered Chemical Engineers --
Chemical engineering --
Chemical kinetics -- 
Chemical reaction --
Chemical synthesis --
Chemical vapor deposition (CVD) --
Chemical solution deposition --
Chemistry --
Chromatographic separation --
Circulating fluidized bed --
Combustion --
Computational fluid dynamics (CFD) --
Conservation of energy -- 
Conservation of mass -- 
Conservation of momentum -- 
Crystallization processes --

D
Deal-Grove model --
Dehumidification --
Dehydrogenation --
Depressurization --
Desorption --
Desulfonation --
Desulfurization --
Diffusion --
Distillation --
Drag coefficient --
Drying --

E

Electrochemical engineering --
Electrodialysis --
Electrokinetic phenomena --
Electrodeposition --
Electrolysis --
Electrolytic reduction --
Electroplating --
Electrostatic precipitation --
Electrowinning --
Emulsion --
Energy --
Engineering -- 
Engineering economics --
Enzymatic reaction --

F

Filtration --
Fluid dynamics --
Flow battery --
Fuel cell --
Fuel technology --

G
Gasification --

H

Heat transfer -- 
History of chemical engineering --
Hydrometallurgy --

I

Immobilization --
Inorganic chemistry --
Ion exchange --

J

K
Kinetics (physics) --

L

Laboratory --
Leaching --

M

Mass balance -- 
Mass transfer -- 
Materials science --
Medicinal chemistry --
Microelectronics --
Microfluidics --
Microreaction technology --
Mineral processing --
Mixing --
Momentum transfer --

N

Nanoengineering --
Nanotechnology --

O

Organic chemistry --

P

Periodic table -- 
Pharmacology --
Physical chemistry -- 
Plastic --  
Polymer -- 
Process control -- 
Process design -- 
Process modeling --
Process safety --

Q

Qualitative inorganic analysis -- 
Quantitative analysis --
Quantum chemistry --  
Quartz --

R

Rate equation -- 
Reverse osmosis --

S

Science --
Separation processes --
Solid-state chemistry -- 
Solvent extraction --
Supercritical fluids --

T

Thermodynamics --
Timeline of chemical element discovery --
Transport phenomena

U

Ultrafiltration --
Unit operation --

V
Volatility --

W

Water and waste water treatment --
Waste minimization --

X

Y

Z

Zeolite --  
Zinc --  
Zinnwaldite  -- 
Zircon --  
Zirconium --  
Zone melting --

Chemical engineering
Fid. A fid is a conical tool traditionally made of wood or bone. It is used to work with rope and canvas in marlinespike seamanship. A fid differs from a marlinspike in material and purposes. A marlinspike is used in working with wire rope, natural and synthetic lines, may be used to open shackles, and is made of metal. A fid is used to hold open knots and holes in canvas, and to separate the "lays" (or strands) of synthetic or natural rope for splicing.  A variation of the fid, the gripfid, is used for ply-split braiding. The gripfid has a jamming cleat to pull a cord back through the cord split by the fid's point.

Modern fids are typically made of aluminum, steel, or plastic.  In addition to holding rope open to assist the creation of a rope splice, modern push fids have markings for precise measurements in a variety of sizes of rope.  The length of these fids is typically 21 or 22 times the diameter of rope to be spliced.  A  diameter rope would have any accompanying fid  in length with hash-marks denoting the long and short fid measurements. A short fid is  a fid length and a long fid is  the overall fid length.

Modern major rope manufacturers such as Yale Cordage, New England Ropes, and Samson Rope Technologies each have full sets of published splicing directions available on their websites.  Typically, all splice directions measurements use fid-length as the unit of measurement.
  
Below is a chart that shows exact measurements of full fid lengths, short fid lengths, and long fid lengths, using 21 times the diameter of the rope.

See also 

 Eye splice
 Marlinspike
 Rope splicing
 Top

References

External links

Animated splice & image of fid in use
Instructable for creating a fid for use with paracord

Ropework
Tools
Uranium carbide. Uranium carbide, a carbide of uranium, is a hard refractory ceramic material. It comes in several stoichiometries (x differs in ), such as uranium methanide (UC, CAS number 12070-09-6), uranium sesquicarbide (U2C3, CAS number 12076-62-9),
and uranium acetylide (UC2, CAS number 12071-33-9).

Like uranium dioxide and some other uranium compounds, uranium carbide can be used as a nuclear fuel for nuclear reactors, usually in the form of pellets or tablets. Uranium carbide fuel was used in late designs of nuclear thermal rockets.

Uranium carbide pellets are used as fuel kernels for the US version of pebble bed reactors; the German version uses uranium dioxide instead.

As nuclear fuel, uranium carbide can be used either on its own, or mixed with plutonium carbide (PuC and Pu2C3). The mixture is also labeled as uranium-plutonium carbide ( (U,Pu)C ).

Uranium carbide is also a popular target material for particle accelerators.

Ammonia synthesis from nitrogen and hydrogen is sometimes accomplished in the presence of uranium carbide acting as a catalyst.

See also
 Uranium boride
 Thorium carbide

References

Carbides
Uranium compounds
Nuclear materials
Rock salt crystal structure
Otto Lehmann (physicist). Otto Lehmann (13 January 1855 in Konstanz, Germany – 17 June 1922 in Karlsruhe) was a German physicist and "father" of liquid crystal.

Life
Otto was the son of Franz Xavier Lehmann, a mathematics teacher in the Baden-Wurtemberg school system, with a strong interest in microscopes. Otto learned to experiment and keep records of this findings. Between 1872 and 1877, Lehmann studied natural sciences at the University of Strassburg and obtained the Ph.D. under crystallographer Paul Groth. 
Otto used polarizers in a microscope so that he might watch for birefringence appearing in the process of crystallization.

Initially becoming a school teacher for physics, mathematics and chemistry in Mülhausen (Alsace-Lorraine), he started university teaching at the RWTH Aachen University in 1883. In 1889, he succeeded Heinrich Hertz as head of the Institute of Physics in Karlsruhe.

Lehmann received a letter from Friedrich Reinitzer asking for confirmation of some unusual observations. As Dunmur and Sluckin(2011) say
It was Lehmann's jealously guarded and increasingly prestigious microscope, not yet available off the shelf, which had attracted Reinitzer's attention. With Reinitzer's peculiar double-melting liquid, a problem in search of a scientist had met a scientist in search of a problem.
The article "On Flowing Crystals" that Lehmann wrote for Zeitschrift für Physikalische Chemie addresses directly the question of phase of matter involved, and leaves in its wake the science of liquid crystals.

Lehmann was an unsuccessful nominee for a Nobel Prize from 1913 to 1922.

Work
Selbstanfertigung physikalischer Apparate. Leipzig 1885.
Molekularphysik (i.e. Molecular physics). 2 Bde, Leipzig 1888/89.
Die Kristallanalyse (i.e. The Analysis of Crystals). Leipzig 1891.
Elektricität und Licht (i.e. Electricity and Light). Braunschweig 1895.
Flüssige Krystalle (i.e. Liquid Crystals). Leipzig 1904.
Die scheinbar lebenden Krystalle. Eßlingen 1907.
Die wichtigsten Begriffe und Gesetze der Physik. Berlin 1907.
Flüssige Kristalle und ihr scheinbares Leben. Forschungsergebnisse dargestellt in einem Kinofilm. Voss, Leipzig 1921.

References
 David Dunmur & Tim Sluckin (2011), Soap, Science, and Flat-screen TVs: a history of liquid crystals, pp 20–7, Oxford University Press  .
 Michel Mitov (2014), Liquid-Crystal Science from 1888 to 1922: Building a Revolution, in ChemPhysChem, vol. 15, pp 1245–1250.

1855 births
1922 deaths
19th-century German physicists
People from Konstanz
People from the Grand Duchy of Baden
University of Strasbourg alumni
Academic staff of the Karlsruhe Institute of Technology
Academic staff of RWTH Aachen University
20th-century German physicists
System integration testing. System integration testing (SIT) involves the overall testing of a complete system of many subsystem components or elements.  The system under test may be composed of electromechanical or computer hardware, or software, or hardware with embedded software, or hardware/software with human-in-the-loop testing. SIT is typically performed on a larger integrated system of components and subassemblies that have previously undergone subsystem testing.

SIT consists, initially, of the "process of assembling the constituent parts of a system in a logical, cost-effective way, comprehensively checking system execution (all nominal and exceptional paths), and including a full functional check-out."  Following integration, system test is a process of "verifying that the system meets its requirements, and validating that the system performs in accordance with the customer or user expectations."

In technology product development, the beginning of system integration testing is often the first time that an entire system has been assembled such that it can be tested as a whole.  In order to make system testing most productive, the many constituent assemblies and subsystems will have typically gone through a subsystem test and successfully verified that each subsystem meets its requirements at the subsystem interface level. 

In the context of software systems and software engineering, system integration testing is a testing process that exercises a software system's coexistence with others. With multiple integrated systems, assuming that each have already passed system testing, SIT proceeds to test their required interactions. 
Following this, the deliverables are passed on to acceptance testing.

Software system integration testing 
For software SIT is part of the software testing life cycle for collaborative projects. Usually, a round of SIT precedes the user acceptance test (UAT) round. Software providers usually run a pre-SIT round of tests before consumers run their SIT test cases.

For example, if an integrator (company) is providing an enhancement to a customer's existing solution, then they integrate the new application layer and the new database layer with the customer's existing application and database layers.
After the integration is complete, users use both the new part (extended part) and old part (pre-existing part) of the integrated application to update data. A process should exist to exchange data imports and exports between the two data layers. This data exchange process should keep both systems up-to-date. The purpose of system integration testing is to ensure all parts of these systems successfully co-exist and exchange data where necessary.

There may be more parties in the integration, for example the primary customer (consumer) can have their own customers; there may be also multiple providers.

See also
 Integration testing
 User acceptance testing (UAT)
 Systems integration

References

Systems engineering
Software testing
testing