omniomni/omni-engineering huggingface dataset:
VFW-Fokker. VFW-Fokker GmbH was a joint venture of Fokker and Vereinigte Flugtechnische Werke (VFW) started in 1969 that, from then on, controlled the ERNO initiative.

The Entwicklungsring Nord (Northern development circle) — abbreviated ERNO — was a 1961 joint venture of Bremen-based Weserflug and Focke-Wulf with Hamburger Flugzeugbau to develop parts for rockets and get involved in space activities.

VFW-Fokker 614

In 1961 work began on a small, jet-powered transport aircraft initially styled Erno-61-4. After Weserflug and Focke Wulf formally merged into Vereinigte Flugtechnische Werke (VFW) in 1964, the machine was redesignated VFW 614. The draft design was amended to a STOL 40-44 passenger jet with overwing engines, for easier operation from unprepared runways. German government subsidies enabled development to start in earnest in 1966. The first prototype started in August 1968, but then VFW and Fokker of the Netherlands formed a joint transnational holding company.

The prototype flew on July 14, 1971, but crashed next February. Two more prototypes flew in 1972. German, FAA, and French DGA certifications completed in 1974, 1975, and 1976 respectively. The collaborative production arrangements involved Messerschmitt-Bölkow-Blohm (MBB) in Germany, Fokker VFW in the Netherlands and SABCA and Fairey in Belgium. The first sale was to Cimber Air, which started commercial flights in November 1975.

The VFW-Fokker alliance affected the VFW 614 negatively, as Fokker needed to sell its competing F27 and F28. National subsidies were diverted to the Airbus program, and the end came for the VFW-614. On August 19, 1977, the nineteenth (including prototypes) and last machine was completed.

Few VFW 614 aircraft remained in use. Only the Koln/Bonn Flugbereitschaft der Luftwaffe continued flying VFW 614 until they finally ceased in 1998. Only DLR in Braunschweig (region) and EADS Airbus at Bremen now retain the machines for research duties.

Other developments

VFW-Fokker teamed with Republic Aviation to develop the D-24 Alliance Variable sweep wing VTOL aircraft as part of the AVS ("Advanced Vertical Strike").

The European Space Agency ESA in June 1974 named a consortium headed by ERNO-VFW Fokker (Zentralgesellschaft VFW-Fokker GmbH) to build pressurized modules for Spacelab. British Aerospace, under contract to ERNO-VFW Fokker, built five -long, unpressurized, U-shaped pallet segments.

West Germany provided 53.3% of Spacelab's cost and fulfilled 52.6% of all Spacelab work contracts. ERNO VFW Fokker, in competition with MBB, submitted the winning design, and became the prime contractor for Spacelab. MBB in 1981 took over VFW Fokker. The ERNO plant in Bremen continued as the headquarters for Spacelab design, production management, component testing, and assembly. Today, it is a part of EADS Astrium Space Transportation.

References

External links

VFW-Fokker Vfw 614 Regional jet

Defunct aircraft manufacturers of Germany
Former joint ventures
Fokker
Exp. Exp or EXP may stand for:

 Exponential function, in mathematics
 Expiry date of organic compounds like food or medicines
 Experience points, in role-playing games
 EXPTIME, a complexity class in computing
 Ford EXP, a car manufactured in the 1980s
 Exp (band), an Italian group in the 1990s
 "EXP" (song), a song by The Jimi Hendrix Experience from the album Axis: Bold as Love
 EXP (calculator key), to enter numbers in scientific or engineering notation
 EXP, at Northeastern University

See also
 Exponential map (disambiguation)
Macintosh II family. The Macintosh II is a family of personal computers that was designed, manufactured and sold by Apple Computer, Inc. from 1987 to 1993. The Macintosh II was the initial model, representing the high-end of the Macintosh line for the time.  Over the course of the next six years, seven more models were produced, culminating with the short-lived Macintosh IIvi and Macintosh IIvx models. Apple retired the Macintosh II name when it moved to Motorola 68040 processors; the Centris and Quadra names were used instead.

Features
Unlike prior Macintosh models, which are "all-in-one" designs, the Macintosh II models are "modular" systems which do not include built-in monitors and are expandable. Beginning with the Macintosh II and culminating in the Macintosh IIfx, the Macintosh II family was Apple's high-end line from 1987 until the introduction of the Motorola 68040-based Macintosh Quadra computers in 1991.

Expansion was provided by way of NuBus, which become the standard expansion bus for the entire Macintosh line for almost a decade. The Macintosh II was the first to officially support color displays, and the first (apart from the Macintosh XL) to support a screen resolution larger than 512x384.

The Macintosh II is also the first to use a Motorola 68000 series processor other than the Motorola 68000. Except for the original Macintosh II which launched the line with a Motorola 68020 clocked at 16 MHz, they exclusively used the Motorola 68030 microprocessor, even after the Motorola 68040 was introduced. Apple would eventually adopt the '040 with the introduction of the Quadra 700 and 900, positioning these models as high-end workstation-class machines for graphics and scientific computing, while positioning the Macintosh II family as a mainstream desktop computer.

Legacy
During the Macintosh II series' lifespan, they rose to become among the most powerful personal computers available. While the Macintosh II series itself was replaced by the Macintosh Centris and Quadra, the Macintosh LC and Performa families continued to use the II's 68030 technology long after the 68040 was introduced and the PowerBook continued to use the '030 into the Power Macintosh era.

Models

Macintosh II series memory map

Timeline

See also
 List of Mac models grouped by CPU type

References

 Mac II Series Index, Low End Mac

 
Discontinued Apple Inc. products
Products and services discontinued in 1993
Computer-related introductions in 1987
Basic copper carbonate. Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It can be classified as a coordination polymer or a salt.  It consists of copper(II) bonded to carbonate  and hydroxide with formula . It is a green solid that occurs in nature as the mineral malachite. It has been used since antiquity as a pigment, and it is still used as such in artist paints, sometimes called verditer, green bice, or mountain green.

Sometimes basic copper carbonate refers to ()2()2, a blue crystalline solid also known as the mineral azurite. It too has been used as pigment, sometimes under the name mountain blue or blue verditer.

Both malachite and azurite can be found in the verdigris patina that is found on weathered brass, bronze, and copper. The composition of the patina can vary, in a maritime environment depending on the environment a basic chloride may be present, in an urban environment basic sulfates may be present.

This compound is often improperly called (even in chemistry articles) copper carbonate,  cupric carbonate, and similar names.  The true (neutral)  copper(II) carbonate CuCO3 is not known to occur naturally.  It is decomposed by water or moisture from the air.  It was synthesized only in 1973 by high temperature and very high pressures.

Preparation

 
Basic copper carbonate is prepared by combining aqueous solutions of copper(II) sulfate and sodium carbonate. Basic copper carbonate precipitates from the solution, with release of carbon dioxide :

Basic copper carbonate can also be prepared by treating aqueous solutions of copper(II) sulfate with sodium bicarbonate.

Copper(II) sulfate may also be substituted with Copper(II) chloride.

Reactions 
Basic copper carbonate is decomposed by acids, such as solutions of hydrochloric acid , into the copper(II) salt and carbon dioxide.

In 1794 the French chemist Joseph Louis Proust (1754–1826) thermally decomposed copper carbonate to CO2 and CuO, cupric oxide.

The basic copper carbonates, malachite and azurite, both decompose forming H2O, CO2, and CuO, cupric oxide.

Uses
Basic copper carbonate is used to remove thiols and hydrogen sulfide from some gas streams, a process called "sweetening". Like many other copper compounds, it also has been used as an algaecide, wood preservative and similar applications.  It is a precursor to various catalysts and copper soaps.

Both malachite and azurite, as well as synthetic basic copper carbonate have been used as pigments. One example of the use of both azurite and its artificial form blue verditer is the portrait of the family of Balthasar Gerbier by Peter Paul Rubens. The green skirt of Deborah Kip is painted in azurite, smalt, blue verditer (artificial form of azurite), yellow ochre, lead-tin-yellow and yellow lake. The green color is achieved by mixing blue and yellow pigments.

References

External links

National Pollutant Inventory – copper and compounds fact sheet
Azurite at ColourLex
Blue verditer at ColourLex
  

Carbonates
Copper(II) compounds
Pyrotechnic colorants
Hydroxides
Miksa Déri. Miksa Déri (27 October 1854 in Bács, Austrian Empire – 3 March 1938) was a Hungarian electrical engineer, inventor, power plant builder. He contributed with his partners Károly Zipernowsky and Ottó Bláthy, in the development of the closed iron core transformer and the ZBD model. His other important invention was the constant voltage AC electrical generator in the Ganz Works in 1883. The missing link of a full Voltage sensitive - voltage intensive (VSVI) system was the reliable AC Constant Voltage generator. Therefore, the invention of the constant voltage generator at the Ganz Works had  crucial role in the beginnings of the industrial scale AC power generating, because only these type of generators can produce a stated output voltage, regardless of the value of the actual load.

ZBD was an abbreviation of the three men's names: Zipernowsky, Bláthy and Déri.

Déri is also noted for inventing the single phase type of repulsion motor

Education 
 There is a secondary school named after Miksa Déri in Mátészalka Hungary.
 There is a secondary school named after Miksa Déri in Szeged Hungary that offers courses preparing students for the engineering fields.

References

External links
 Hungarian Patent Office's Miksa Déri (1854 - 1938)
  Biography of Miksa Déri

1854 births
1938 deaths
Hungarian inventors
Hungarian electrical engineers
Engineers from Austria-Hungary
Inventors from Austria-Hungary
Károly Zipernowsky. Károly Zipernowsky (born as Carl Zipernowsky, 4 April 1853 in Vienna – 29 November 1942 in Budapest) was an Austrian-born Hungarian electrical engineer. He invented the transformer with his colleagues (Miksa Déri and Ottó Bláthy) at the famous Hungarian manufacturing company Ganz Works and he contributed significantly with his works also to other AC technologies.

Biography

Zipernowsky, with Ottó Bláthy and Miksa Déri, all of Ganz and Company, were researching ways of increasing efficiency of electrical power transmission. They experimented with power supplies and current transformation, which led to the invention of the ZBD alternating current transformer in 1885. The ZBD system is based on a closed-iron ring core with an arbitrary diameter and a coil around the core, which conducts AC current. Their system converted higher voltage suitable for energy transmission to lower "service"-level voltage (step-down transformer). Nikola Tesla then proposed the use of step-up transformers, which would output higher voltage than they received. This principle is widely used for power transmission over long distances all over the world.

References

External links 
 Technical University of Budapest.  "Károly Zipernowsky". Budapest, 1996.
  His life

¨

1853 births
1942 deaths
Hungarian inventors
Hungarian electrical engineers
Hungarian expatriates in Austria
Engineers from Austria-Hungary
Inventors from Austria-Hungary
Engineers from Vienna
Interstellar ark. An interstellar ark is a conceptual starship designed for interstellar travel. Interstellar arks may be the most economically feasible method of traveling such distances. The ark has also been proposed as a potential habitat to preserve civilization and knowledge in the event of a global catastrophe.

Such a ship would have to be large, requiring a large power plant. The Project Orion concept of propulsion by nuclear pulses has been proposed. The largest spacecraft design analyzed in Project Orion had a  diameter and weighed approximately 8 million tons. It could be large enough to host a city of 100,000 or more people.

Thrust concepts 
Another concern is selection of power sources and mechanisms which would remain viable for the long time spans involved in interstellar travel through the desert of space. The longest-lived space probes are the Voyager program probes, which use radioisotope thermoelectric generators having a useful lifespan of a mere 50 years.

One propulsion method for a crewed spacecraft could be a fusion microexplosion nuclear pulse propulsion system (like that proposed in Project Daedalus) that may allow it to obtain an interstellar cruising velocity of up to 10% of the speed of light. However, if the ship is capable of transits requiring hundreds of thousands of years, chemical and gravitational slingshot propulsion may be sufficient.

Specific proposals and research projects 
The Enzmann starship proposed in 1964 is a large fusion-powered spacecraft that could function as an interstellar ark, supporting a crew of 200 with extra space for expansion, on multi-year journeys at subluminal speeds to nearby star systems.

In 1955 Project Orion considered nuclear propulsion for spacecraft, suitable for deep space voyages.

In 1973–1978 Project Daedalus was conducted by the British Interplanetary Society to study uncrewed interstellar spacecraft.

See also
Generation ship

References

External links
News article
Lifeboat Foundation

Science fiction themes
Space colonization
Ark
Interstellar travel
Fictional spacecraft by type
EBM. EBM or Ebm may stand for:

 El Borma Airport, in Tunisia
 Ecosystem-based management

Science and technology
 Electron-beam machining
 Electron-beam melting
 Electronic ballot marker
 Espresso Book Machine, a print-on-demand machine
 Evidence-based medicine, an approach to medical research and practice
 Energy-based model, a machine learning model

Companies and organizations
 Elektra Birseck Münchenstein, a Swiss energy company
 English Biscuit Manufacturers, a Pakistani biscuit manufacturer
 Swedish Economic Crime Authority (Swedish: )
 Écoles Belges au Maroc, Belgian international schools in Morocco

Music
 Electronic body music, an electronic music genre
 E-flat minor (Em)
 EBM (album), a 2022 album by British indie rock band Editors
Water integrator. The Water Integrator ( Gidravlicheskiy integrator) was an early analog computer built in the Soviet Union in 1936 by Vladimir Sergeevich Lukyanov. It functioned by careful manipulation of water through a room full of interconnected pipes and pumps. The water level in various chambers (with precision to fractions of a millimeter) represented stored numbers, and the rate of flow between them represented mathematical operations. This machine was capable of solving inhomogeneous differential equations.

The first versions of Lukyanov's integrators were rather experimental, made of tin and glass tubes, and each integrator could be used to solve only one problem. In the 1930s it was the only computer in the Soviet Union for solving partial differential equations.

In 1941, Lukyanov created a hydraulic integrator of modular design, which made it possible to assemble a machine for solving various problems. Two-dimensional and three-dimensional hydraulic integrators were designed.

In 1949–1955, an integrator in the form of standard unified units was developed at the NIISCHETMASH Institute. In 1955, the Ryazan plant of calculating and analytical machines began the serial production of integrators with the factory brand name “IGL” (russian: Интегратор Гидравлический Лукьянова - integrator of the Lukyanov hydraulic system). Integrators were widely distributed, delivered to Czechoslovakia, Poland, Bulgaria and China. 

A water integrator was used in the design of the Karakum Canal in the 1940s, and the construction of the Baikal–Amur Mainline in the 1970s. Water analog computers were used in the Soviet Union until the 1980s for large-scale modelling. They were used in geology, mine construction, metallurgy, rocket production and other fields.

Currently, two hydraulic integrators are kept in the Polytechnic Museum in Moscow.

See also
 History of computing hardware
 MONIAC Computer
 Fluidics

References

Further reading 
 

 Collection of Water Integrator Patents

 Technical Reports involving use/design of Water Integrators USACE, etc.

External links
 MIT water computer
 Translated article from Russian Magazin "Science and Life" about water integrators in the Soviet Union
 Translation of an archived article from O. V. Solovyov on the former webpage of the Polytechnic Museum in Moscow
 Hydraulic Analog Computer Technical Reports. A "collection of technical reports from the USACE (US Army Corps of Engineers) that was written by the Civil and Sanitary Engineering Department at MIT as part of a contract to create a Hydraulic Computer for solving diffusion-type Partial Differential Equations" from 1953

One-of-a-kind computers
Early computers
Analog computers
Soviet inventions
EFT. An eft is a newt in the terrestrial juvenile phase.

EFT, EfT, or eft also may refer to:

Places 
 École Française de Téhéran, an international school in Iran
 Monroe Municipal Airport (FAA:EFT), Wisconsin, United States

Science and technology 
 Ecosystem Functional Type, in ecology
 Effective field theory, in physics
 Electrical fast transient, in electrical engineering
 Embedded figures test, in cognitive psychology 
 Emotionally focused therapy, in psychotherapy
 Ewing family of tumors, in medicine
 Exploration Flight Test-1, a 2014 NASA test flight

Other uses 
 Electronic funds transfer, in banking
 Emotional Freedom Techniques, in alternative medicine
 Escape from Tarkov, a 2017 FPS video game
 Evangelical Fellowship of Thailand, in Christianity

See also

EFTS (disambiguation)
Write-ahead logging. In computer science, write-ahead logging (WAL) is a family of techniques for providing atomicity and durability (two of the ACID properties) in database systems.

A write ahead log is an append-only auxiliary disk-resident structure used for crash and transaction recovery. The changes are first recorded in the log, which must be written to stable storage, before the changes are written to the database.

The main functionality of a write-ahead log can be summarized as:

 Allow the page cache to buffer updates to disk-resident pages while ensuring durability semantics in the larger context of a database system.
 Persist all operations on disk until the cached copies of pages affected by these operations are synchronized on disk. Every operation that modifies the database state has to be logged on disk before the contents on the associated pages can be modified
 Allow lost in-memory changes to be reconstructed from the operation log in case of a crash.

In a system using WAL, all modifications are written to a log before they are applied. Usually both redo and undo information is stored in the log.

The purpose of this can be illustrated by an example. Imagine a program that is in the middle of performing some operation when the machine it is running on loses power. Upon restart, that program might need to know whether the operation it was performing succeeded, succeeded partially, or failed. If a write-ahead log is used, the program can check this log and compare what it was supposed to be doing when it unexpectedly lost power to what was actually done. On the basis of this comparison, the program could decide to undo what it had started, complete what it had started, or keep things as they are.

After a certain amount of operations, the program should perform a checkpoint, writing all the changes specified in the WAL to the database and clearing the log.

WAL allows updates of a database to be done in-place. Another way to implement atomic updates is with shadow paging, which is not in-place. The main advantage of doing updates in-place is that it reduces the need to modify indexes and block lists.

ARIES is a popular algorithm in the WAL family.

Modern file systems typically use a variant of WAL for at least file system metadata; this is called journaling.

References

Database algorithms
Message delivery agent. A message delivery agent (MDA), or mail delivery agent, is a computer software component that is responsible for the delivery of e-mail messages to a local recipient's mailbox. It is also called a local delivery agent (LDA).

Within the Internet mail architecture, local message delivery is achieved through a process of handling messages from the message transfer agent, and storing mail into the recipient's environment (typically a mailbox).

Implementation

Many mail handling software products bundle multiple message delivery agents with the message transfer agent component, providing for site customization of the specifics of mail delivery to a user.

Unix 

On Unix-like systems, procmail and maildrop are the most popular MDAs.  The Local Mail Transfer Protocol (LMTP) is a protocol that is frequently implemented by network-aware MDAs.

Invocation 

The mail delivery agent is generally not started from the command line, but is usually invoked by mail delivery subsystems, such as a mail transport agent, or a mail retrieval agent.

Unix-like 
 Cyrus IMAP - A mail server suite that includes a mail delivery agent
 dovecot - A mail server suite that includes a mail delivery agent
 fetchmail - Primarily a Mail retrieval agent (MRA)
 getmail - simpler, more secure, modern fetchmail alternative
 fdm — modern replacement for both fetchmail and procmail from the author of tmux
 maildrop or courier-maildrop - traditional procmail replacement, part of Courier Mail Server, but can also be used with other mail servers
 procmail - old, but still used
 bin/mail, the MDA part of Sendmail - Sendmail is one of the oldest email packages
 Sieve mail filtering language - a standardised mail filtering language; also, a modern replacement for procmail from the GNU Mailutils package

See also
 Message transfer agent (MTA)
 Mail retrieval agent (MRA)
 Message submission agent (MSA)
 Message user agent (MUA) a.k.a. email client
 E-mail agent (infrastructure) (MxA)

References