omniomni/omni-engineering huggingface dataset:
Independent electron approximation. In condensed matter physics, the independent electron approximation is a simplification used in complex systems, consisting of many electrons, that approximates the electron–electron interaction in crystals as null. It is a requirement for both the free electron model and the nearly-free electron model, where it is used alongside Bloch's theorem. In quantum mechanics, this approximation is often used to simplify a quantum many-body problem into single-particle approximations.

While this simplification holds for many systems, electron–electron interactions may be very important for certain properties in materials. For example, the theory covering much of superconductivity is BCS theory, in which the attraction of pairs of electrons to each other, termed "Cooper pairs", is the mechanism behind superconductivity. One major effect of electron–electron interactions is that electrons distribute around the ions so that they screen the ions in the lattice from other electrons.

Quantum treatment 
For an example of the Independent electron approximation's usefulness in quantum mechanics, consider an N-atom crystal with one free electron per atom (each with atomic number Z). Neglecting spin, the Hamiltonian of the system takes the form:
 
where  is the reduced Planck constant, e is the elementary charge, me is the electron rest mass, and  is the gradient operator for electron i. The capitalized  is the Ith lattice location (the equilibrium position of the Ith nuclei) and the lowercase  is the ith electron position.

The first term in parentheses is called the kinetic energy operator while the last two are simply the Coulomb interaction terms for electron–nucleus and electron–electron interactions, respectively. If the electron–electron term were negligible, the Hamiltonian could be decomposed into a set of N decoupled Hamiltonians (one for each electron), which greatly simplifies analysis. The electron–electron interaction term, however, prevents this decomposition by ensuring that the Hamiltonian for each electron will include terms for the position of every other electron in the system. If the electron–electron interaction term is sufficiently small, however, the Coulomb interactions terms can be approximated by an effective potential term, which neglects electron–electron interactions. This is known as the independent electron approximation. Bloch's theorem relies on this approximation by setting the effective potential term to a periodic potential of the form  that satisfies , where  is any reciprocal lattice vector (see Bloch's theorem). This approximation can be formalized using methods from the Hartree–Fock approximation or density functional theory.

See also 

 Strongly correlated material

References 

 Omar, M. Ali (1994). Elementary Solid State Physics, 4th ed. Addison Wesley. .

Electron
Hydrological code. A hydrological code or hydrologic unit code is a sequence of numbers or letters (a geocode) that identify a hydrological unit or feature, such as a river, river reach, lake, or area like a drainage basin (also called watershed in North America) or catchment.

One system, developed by Arthur Newell Strahler, known as the Strahler stream order, ranks streams based on a hierarchy of tributaries. Each segment of a stream or river within a river network is treated as a node in a tree, with the next segment downstream as its parent. When two first-order streams come together, they form a second-order stream. When two second-order streams come together, they form a third-order stream, and so on.

Another example is the system of assigning IDs to watersheds devised by , known as the Pfafstetter Coding System or the Pfafstetter System. Drainage areas are delineated in a hierarchical fashion, with "level 1" watersheds at continental scales, subdivided into smaller level 2 watersheds, which are divided into level 3 watersheds, and so on. Each watershed is assigned a unique number, called a Pfafsetter Code, based on its location within the overall drainage system.

Europe
A comprehensive coding system is in use in Europe. This system codes from the ocean to the so-called primary catchment. The system determines a set of oceans or endorheic systems identified by a letter. These systems are subdivided into a maximum of 9 seas. The seas are numbered 1 to 9. Seas lying far from the ocean, for example the Black Sea receive a higher number. The seas are delimited using the so-called definitions made by the International Hydrographic Organization in 1953. The coasts of these seas are defined clockwise from north west to south east from the strait where the sea connects to the ocean or the other seas.

Subsequently every watershed along this coast is assigned a number using the Pfafstetter Coding System. This implies that the four largest watersheds are selected and receive numbers 2,4,6, or 8. The watersheds in between the large systems receive numbers 3, 5, and 7. Numbers 1 and 9 are used for the small watersheds on the edges of the strait. The smaller systems can subsequently be numbered recursively or kept together for grouping purpose.
Landmasses (Continent and Islands) are also numbered in a logical manner, along a clock-wise oriented sea. For Europe containing many inner seas this feature helps to read the relative location of a hydrological object in the sea.

United States

See also
 Hydrologic Unit Modeling for the United States
 Water Resource Region

References

External links
 
 
 

Hydrology
Limnology
Water and the environment
Geocodes
European Steel Technology Platform. The European Steel Technology Platform (ESTEP) is a European Seventh Framework Programme initiative to improve the competitive situation of the European Union in the field of steel technology. The main objective of the programme is to produce a Strategic Research Agenda (SRA).

The programme is a joint initiative (Public-Private Partnership) of the European Commission, representing the European Communities, and the industry. The ESTEP was launched in March 2004 by European Research Commissioner Philippe Busquin and Guy Dollé, Chief Executive Officer of Arcelor and President of EUROFER.

See also
 European Technology Platform
 Joint Technology Initiative

References
 Research Fund for Coal and Steel (EU)
 Technology platform offers new dynamism for European steel

External links
 European Steel Technology Platform (EUROFER)
 European Steel Technology Platform (EU)

Science and technology in Europe
European Union and science and technology
European Technology Platform for the Electricity Networks of the Future. The European Technology Platform (ETP) for the Electricity Networks of the Future (SmartGrids) is a European Commission initiative that aims at boosting the competitive situation of the European Union in the field of electricity networks, especially smart power grids. The ETP represents all European stakeholders. The establishment of an ETP in this field was for the first time suggested by the industrial stakeholders and the research community at the first International Conference on the Integration of Renewable Energy Sources and Distributed Energy Resources, which was held in December 2004.

The SmartGrids Platform was started by the European Commission Directorate General for Research of the European Commission in 2005.

See also 

 Net metering
 Unified Smart Grid or USG (United States proposed system)
 V2G

References

Sources
 International Conference on the Integration of Renewable Energy Sources and Distributed Energy Resources
 Strategic Research Agenda

External links
 SmartGrids official website
 CORDIS official ETPs website

Science and technology in Europe
European Union and science and technology
European Technology Platform for Wind Energy. The European Technology Platform for Wind Energy (TPWind) is a European Seventh Framework Programme initiative to improve the competitive situation of the European Union in the field of wind energy.

The programme is a joint initiative (Public-Private Partnership) of the European Commission, representing the European Union, and the industry. The main objective of the programme is to produce a Strategic Research Agenda (SRA).

See also
 European Technology Platform
 Joint Technology Initiative

References
 Vision document

External links
 European Technology Platform for Wind Energy

Science and technology in Europe
European Union and science and technology 
Tech
European Technology Platform on Smart Systems Integration. The European Technology Platform on Smart Systems Integration (EPoSS) is a European Seventh Framework Programme initiative to improve the competitive situation of the European Union in the field of Smart Systems Technologies and integrated Micro and Nanosystems.

The programme is a joint initiative (Public-Private Partnership) of the European Commission, representing the European Communities, and the industry.

EPoSS, the European Technology Platform on Smart Systems Integration, is an industry-driven policy initiative, defining R&D and innovation needs as well as policy requirements related to Smart Systems Integration and integrated Micro- and Nanosystems.

EPoSS is an international non-profit association according to German law. The EPoSS Association was founded on 18 September 2013. Its structure consists of Board, General Assembly, Executive Committee, Working Groups and Office.

EPoSS aims to:

 provide a common European approach on Innovative Smart Systems Integration from research to production, outlining the key issues for a strategic European innovation process,
 define priorities for common research and innovation in the future,
 formulate commonly agreed road maps for action (updating, assembling and completing existing material and approaches) and provide a strategic R&D agenda, and
 mobilise public and private human, infrastructural and financial resources.

The initiative is of immediate importance in view of defining research and technology priorities for the EU Framework Programme for Research and Innovation, for raising more critical mass as well as resources and for coordinating different initiatives (national, regional, EUREKA, European public funding and industry).

EPoSS is a strategic partner of the European Platform for Sport Innovation.

See also
 European Technology Platform
 Joint Technology Initiative

References

 Interrelation between ICT ETPs
 EPoSS (speech)
Akhras, G., "Smart Materials and Smart Systems for the Future", Canadian Military Journal, 08/2000

Internet-of-Things in 2020 – A roadmap for the future, 2008 

Electronic Components and Systems, Strategic Research Agenda 2018 (ECS-SRA)

European Union and science and technology
Information technology organizations based in Europe
Science and technology in Europe
Ghassan Afiouni. Ghassan Afiouni () is a scientist who was born in Tripoli, a town in Lebanon located on the coast of the Mediterranean Sea. Afiouni developed a type of compressed wood that cannot be burned. The invention has been patented in the United States of America and he holds three other related patents  pertaining to the field of fire safety, for which he was awarded Pennsylvania's Gold Award.

Career
A teacher who used to work at Ibn Khuldoon National School, Mr Afioni now lives with his family in his native country Lebanon(Tripoly) and works as an entrepreneurial inventor. Afiouni's achievements during his teaching career included the creation of the school's first ever middle school science fair that is still being sustained. Afiouni enjoyed an incredible rapport with his students in middle school. After he moved to teach IB physics in the Secondary School, he developed a teaching mechanism that involves a projector that allows all class lectures to be recorded. This technique might be employed in some Bahrain universities, as he has given seminars that explain the mechanism of the technique. His latest project was KAG, a car that he developed and created from nothing but shaped piping which gave the car its unique look. The car uses some technologies replacing the rear-view mirror with a camera, automatic open and close doors, and liquid electronic display (LED) lighting all over the body and engine, which is open to view. His past research involves the development of conductive polymers coated on non-conductive substrates for use in multi-spectral screening material.  He also worked on the use of zero-valent metal and ultrasonic energy for an in-situ ground water remediation of chlorinated hydrocarbons.  He received the Kathleen McIntyre Award for his outstanding achievements.

References

1972 births
Living people
Lebanese scientists
115 series. The  is a DC electric multiple unit (EMU) train type developed by Japanese National Railways (JNR) and now operated by West Japan Railway Company (JR-West), and the Shinano Railway.

Operations

JR East
JR East operated their last 115 series train on 11 March 2022. 115 series trains were previously used on the Shōnan-Shinjuku Line, Takasaki Line, Utsunomiya Line, Chuo Main Line(East Line), Shinonoi Line, Oito Line, Agatsuma Line, Ryomo Line, Joetsu Line, Shinetsu Main Line, Yahiko Line, and the Echigo Line.

JR-West
Currently used on the Hakubi Line, Maizuru Line, Sagano Line, Sanin Main Line and the Sanyō Main Line

JR Central
Formerly used on the Minobu Line, Gotemba Line and the Tōkaidō Main Line. Sets owned by JR East currently operate on the JR Central Iida Line and Chūō Main Line (West Line).

Shinano Railway
Currently used on the Shinano Railway Line. Start of retirement in July 2020 with the debut of the new SR1 series on 4 July 2020.

Variants

115-0 series
This is a cold-weather and mountainous line version of the earlier 113 series. The first examples were introduced from 1963 on the Takasaki Line out of .

115-300 series
Air-conditioned version introduced from 1973.

115-1000 series
Introduced from 1978 with increased seat pitch and improved cold-weather performance.

115-2000 series
Hiroshima, Shimonoseki and Shizuoka area version introduced in 1978. Specifications based on 115-1000 series.

115-3000 series
Two-door version introduced from November 1982 to replace 153 series EMUs on "Rapid" services in the Shimonoseki area.

115-3500 series
Former 117 series MoHa 117 and MoHa 116 two-door cars converted from May 1992 for use in the Okayama and Hiroshima areas.

115-6000 series
JR-West 2-car sets converted in 1999 by building new cabs at one end of former MoHa (non-driving motor) cars.

Livery variations

Special liveries
In January 2017, Niigata-based set N3 was repainted into the original "Niigata Livery" of red and yellow formerly carried by JNR 70 series EMU trains.

In April 2017, Shinano Railway three-car set S7 was repainted into the original Nagano livery of cream and green as part of the Shinshu area promotional campaign to be held from July to September 2017.

In September 2017, Niigata-based set N37 was repainted in the first "Niigata area" livery.

Withdrawal
Withdrawals first begun in 1985 following the introduction of 211 series. The 115 series were gradually phased out on some services. The first units were scrapped in 1987.

Preserved examples

Former JR East end car KuMoHa 115 1061 is scheduled to be displayed at the Niigata City Niitsu Railway Museum in Niitsu, Niigata between July and September 2017. Car KuHa 115 1106 is preserved at an onsen in Chikuma, Nagano.

References

External links

 JR East 115 series 

Electric multiple units of Japan
Train-related introductions in 1963
East Japan Railway Company
West Japan Railway Company
Shinano Railway Line
1500 V DC multiple units of Japan
Supermarine Sea Eagle. The Supermarine Sea Eagle was a British, passenger–carrying, amphibious flying boat. It was designed and built by the Supermarine Aviation Works for its subsidiary, the British Marine Air Navigation Co Ltd, to be used on their cross-channel route between Southampton, the Channel Islands and France.

Service
Three civilian aircraft were constructed, G-EBFK, G-EBGR and G-EBGS and the regular service between Southampton and Guernsey began on 25 September 1923 (the planned service to France was never implemented). This was Britain's first scheduled passenger air service by flying boat. However, G-EBFK crashed on 21 May 1924; in January 1927, G-EBGS was lost when it was rammed by a ship in the harbor of St Peter Port, Guernsey. The third aircraft continued on the route until 1928 when it was replaced by a Short S.8 Calcutta.

The wooden hull of the surviving Sea Eagle, G-EBGR, was retained by Vickers until 1949, when they presented it to the British Overseas Airways Corporation; BOAC burnt it in 1954 because of a lack of storage space.

Variants
The Supermarine Sheldrake used the hull of the Sea Eagle and the wings of the Seagull with a tractor engine installation. A single example was built.

The Supermarine Scarab was a military flying-boat, based on the Sea Eagle and Sheldrake but with a pusher engine, specially designed for the Spanish Navy. Twelve were eventually built and delivery to the Spanish Naval Air Service for use in the bomber/reconnaissance role during the Rif War. It was fitted with a .303 in (7.7 mm) Lewis gun and a bomb load of 1,000 lb 454 kg.

Operators

Spanish Navy
Spanish seaplane carrier Dédalo

 British Marine Air Navigation Co Ltd
 Imperial Airways

Specifications

See also
 List of flying boats and floatplanes

References

Bibliography
Andrews C.F. and Morgan, E.B. Supermarine Aircraft since 1914. London:Putnam, 1987. .
Jackson, A.J. British Civil Aircraft 1919–1972:Volume III. London:Putnam, 1988. .
London, Peter. British Flying Boats. Sutton Publishers Ltd. 2003. 
"The Supermarine 'Sea Eagle'", Flight, vol. XV, issue 26, pp. 351–352, 28 June 1923.

External links

 Imperial Airways
 The Scarab
 Service

1920s British airliners
Flying boats
Single-engined pusher aircraft
Sea Eagle
Biplanes
Aircraft first flown in 1923
Privilege Management Infrastructure. In cryptography Privilege Management is the process of managing user authorisations based on the ITU-T Recommendation X.509. The 2001 edition of X.509  specifies most (but not all) of the components of a Privilege Management Infrastructure (PMI), based on X.509 attribute certificates (ACs). Later editions of X.509 (2005 and 2009) have added further components to the PMI, including a delegation service (in 2005 ) and interdomain authorisation (in the 2009 edition ).

Privilege management infrastructures (PMIs) are to authorisation what public key infrastructures (PKIs) are to authentication. PMIs use attribute certificates (ACs) to hold user privileges, in the form of attributes, instead of public key certificates (PKCs) to hold public keys. PMIs have Sources of Authority (SoAs) and Attribute Authorities (AAs) that issue ACs to users, instead of certification authorities (CAs) that issue PKCs to users. Usually PMIs rely on an underlying PKI, since ACs have to be digitally signed by the issuing AA, and the PKI is used to validate the AA's signature.

An X.509 AC is a generalisation of the well known X.509 public key certificate (PKC), in which the public key of the PKC has been replaced by any set of attributes of the certificate holder (or subject). Therefore, one could in theory use X.509 ACs to hold a user's public key as well as any other attribute of the user. (In a similar vein, X.509 PKCs can also be used to hold privilege attributes of the subject, by adding them to the subject directory attributes extension of an X.509 PKC). However, the life cycle of public keys and user privileges are usually very different, and therefore it isn't usually a good idea to combine both of them in the same certificate. Similarly, the  authority that assigns a privilege to someone is usually different from the authority that certifies someone's public key. Therefore, it isn't usually a good idea to combine the functions of the SoA/AA and the CA in the same trusted authority. PMIs allow privileges and authorisations to be managed separately from keys and authentication.

The first open source implementation of an X.509 PMI was built with funding under the EC PERMIS project, and the software is available from here. A description of the implementation can be found in.

X.509 ACs and PMIs are used today in Grids (see Grid computing), to assign privileges to users, and to carry the privileges around the Grid. In the most popular Grid privilege management system today, called VOMS, user privileges, in the shape of VO memberships and roles, are placed inside an X.509 AC by the VOMS server, signed by the VOMS server, and then embedded in the user's X.509 proxy certificate for carrying around the Grid.

Because of the rise in popularity of XML SOAP based services, SAML attribute assertions are now more popular than X.509 ACs for transporting user attributes. However, they both have similar functionality, which is to strongly bind a set of privilege attributes to a user.

References 

Cryptography
Communications protocols
European Technology Platform Nanomedicine. The European Technology Platform on Nanomedicine (ETP Nanomedicine) is a European Technology Platform initiative to improve the competitive situation of the European Union in the field of nanomedicine, the application of nanotechnology to medicine.

Overview
An important initiative, led by industry, has been set up together with the European Commission. A group of 53 European stakeholders, composed of industrial and academic experts, has established a European Technology Platform on nanomedicine. The first task of this high level group was to write a vision document for this highly future-oriented area of nanotechnology-based healthcare in which experts describe an extrapolation of needs and possibilities until 2020. Beginning of 2006 this Platform has been opened to a wider participation (December 2006: 150 member organisations) and has delivered a so-called Strategic Research Agenda showing a well elaborated common European way of working together for the healthcare of the future trying to match the high expectations that nanomedicine has raised so far.

Policy Objectives
 Establish a clear strategic vision in the area resulting in a Strategic Research Agenda.
 Decrease fragmentation in nano-medical research.
 Mobilise additional public and private investment.
 Identify priority areas.
 Boost innovation in nanobiotechnologies for medical use.

Topics
Three key priorities have been confirmed by the stakeholders:
 Nanotechnology-based diagnostics including imaging.
 Targeted drug delivery and release.
 Regenerative medicine.

Dissemination of knowledge, regulatory and IPR issues, standardisation, ethical, safety, environmental and toxicity concerns as well as public perception in general and the input from other stakeholders like insurance companies or patient organisations play an important role.

See also
 European Technology Platform
 Joint Technology Initiative

References
 Vision document
 Strategic Research Agenda
 CERTH European Technology Platform Nanomedicine
 Hyperion European Technology Platform Nanomedicine

External links
 European Technology Platform on Nanomedicine

European Union and science and technology
Information technology organizations based in Europe
Science and technology in Europe