omniomni/omni-engineering huggingface dataset:
Sishen–Saldanha railway line. The Sishen–Saldanha railway line, also known as the Ore Export Line (OREX), is an  heavy-haul railway line in South Africa. It connects iron ore mines near Sishen in the Northern Cape with the port at Saldanha Bay in the Western Cape. It is used primarily to transport iron ore (60 million tonnes per year) and does not carry passenger traffic.

The Sishen–Saldanha line was built by Iscor, the then iron and steel parastatal, opening in 1976.

In 1977 the line was transferred to Transnet Freight Rail, then known as South African Railways & Harbours, and was electrified. A voltage of 50 kV AC was chosen instead of the usual 25 kV to haul heavier loads and allow greater distance between transformers.

A single-track line with 10 crossing loops to allow trains travelling in opposite directions to pass was constructed. The number of crossing loops has increased to 19 to increase line capacity.

From an altitude of  at Sishen, the line climbs for  before descending to cross the Orange River about  downstream of Groblershoop. For the next , the line rises and falls before descending towards the Atlantic coast. The railway crosses the Olifants River on a  viaduct between Vredendal and Lutzville and reaches the coast about  north of Saldanha. From there the line follows a coastal route.

Initial train lengths consisted of three class 9E electric locomotives, hauling 210 type CR ore wagons with a payload of 80 tonnes. Upgraded wagons now carry 100 tonnes. Train lengths were increased in 2007 to 342 wagons, employing Radio Distributed Power (RDP) technology. These trains (initially with 10 locomotives, a mix of electric and diesel-electric) and 342 wagons have a total mass of 41,400 tonnes and are  long, the longest production trains in the world. The same 342-wagon trains are now powered by just five 15Es, crewed by one driver and one assistant.

The train length was increased in October 2019 to 375 wagons.

See also 
 South African Class 9E, Series 1
 South African Class 9E, Series 2
 South African Class 15E
 South African Class 34-000
 South African Class 34-400
 South African Class 34-500
 South African Class 34-900
 South African Class 43-000

References 

Railway lines in South Africa
Iron ore railways
Mining railways
Mining in South Africa
3 ft 6 in gauge railways in South Africa
Articles containing video clips
Packet aggregation. In a packet-based communications network, packet aggregation is the process of joining multiple packets together into a single transmission unit, in order to reduce the overhead associated with each transmission.

Packet aggregation is useful in situations where each transmission unit may have significant overhead (preambles, headers, cyclic redundancy check, etc.) or where the expected packet size is small compared to the maximum amount of information that can be transmitted.

In a communication system based on a layered OSI model, packet aggregation may be responsible for joining multiple MSDUs into a single MPDU that can be delivered to the physical layer as a single unit for transmission.

The ITU-T G.hn standard, which provides a way to create a high-speed (up to 1 Gigabit/s) Local area network using existing home wiring (power lines, phone lines and coaxial cables), is an example of a protocol that employs packet aggregation to increase efficiency.

See also 
 Packet segmentation
 Frame aggregation

References

Packets (information technology)
Packet segmentation. In data communications networks, packet segmentation is the process of dividing a data packet into smaller units for transmission over the network. Packet segmentation happens at layer four of the OSI model; the transport layer. Segmentation may be required when:
 The data packet is larger than the maximum transmission unit supported by the network
 The network is unreliable and it is desirable to divide the information into smaller segments to maximize the probability that each one of them can be delivered correctly to the destination

Protocols that perform packet segmentation at the source usually include a mechanism at the destination to reverse the process and reassemble the original packet from individual segments. This process may include automatic repeat-request (ARQ) mechanisms to detect missing segments and to request the source to re-transmit specific segments.

In a communication system based on a layered OSI model, packet segmentation may be responsible for splitting one MPDU into multiple physical layer service data units so that reliable transmission (and potential re-transmission via ARQ) of each one can be performed individually.

The ITU-T G.hn standard, which provides a way to create a high-speed (up to 1 gigabit/s) local area network using existing home wiring (power lines, phone lines and coaxial cables), is an example of a protocol that employs packet segmentation to increase reliability over noisy media.

See also
 Fujitsu Ltd. v. Netgear Inc.
 Packet aggregation
 Segmentation and reassembly

References

Packets (information technology)
IronScheme. IronScheme is an implementation of the Scheme programming language targeting the Microsoft .NET Framework. IronScheme is a complete rewrite of IronLisp, incorporating lessons learnt while developing IronLisp.

IronScheme was planning to build upon the Microsoft Dynamic Language Runtime, but decided to abandon this idea because the DLR branch the project used became out of sync with the trunk, and also because the DLR, according to the developers, could not support the majority of the Scheme's requirements. IronScheme eventually made a limited use of its own version of the Microsoft's DLR, but it had to patch it to be able to implement some required Scheme features like tail call elimination.

See also

 Scheme (programming language)

References

External links
 IronScheme on GitHub

.NET programming languages
Beta software
Scheme (programming language) implementations
Nano Today. Nano Today is dedicated to publishing the most influential and innovative work across nanoscience and technology. The journal considers any article that informs readers of the latest research and advances in the field, research breakthroughs, and topical issues which express views on developments in related fields. Through its unique mixture of peer-reviewed articles, the latest research news, and information on key developments, Nano Today provides comprehensive coverage of this exciting and dynamic field. Established in 2006, it is published six times a year by Elsevier.

References

Elsevier academic journals
Chemistry journals
Nanotechnology journals
Schleicher ASK 16. The ASK 16 was designed by Rudolf Kaiser for production by Alexander Schleicher GmbH & Co of Furth, Germany. The aircraft is of welded tube, wood and fabric construction and has a low-set high-aspect-ratio wing.

Seating is side-by-side for two persons under a fully transparent side-hinged canopy. The standard powerplant is a  Limbach L1700 driving a Hoffman variable-pitch propeller.

The ASK 16 has a retractable tail-wheel undercarriage with the main units mounted under the wings and retracting inwards. It is fitted with dual controls to permit use in the primary training role.

Production and operation

The prototype first flew on 2 February 1971 and a total of 44 aircraft were built for operation by clubs and private owners.  Most of the completed aircraft remained in active service in 2005, including examples flying in Germany, Ireland, Italy, Switzerland, and the United Kingdom.

Specifications

References

1970s German civil aircraft
Schleicher aircraft
Motor gliders
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1971
Single-engined piston aircraft
SC-497-class submarine chaser. 

The SC-497-class submarine chasers were a class of 438 submarine chasers built primarily for the United States Navy from 1941–1944.  The SC-497s were based on the experimental submarine chaser, USS SC-453. Submarine chasers of this variety were collectively nicknamed "the splinter fleet" due to their wooden hulls.

History
The SC-497s were off-shore patrol and anti-submarine warfare vessels. Seventy of the SC-497s were converted into patrol control crafts (SCC), 18 were converted into coastal minesweepers (AMC), and 8 were converted into patrol gunboats, motor (PGM).

Sixteen SC-497s were lost and another one was lost after her conversion into a .

Despite the large number of SC-497s, none are credited with destroying an enemy ship. (USS SC-669 is sometimes incorrectly credited with sinking the Japanese submarine RO-107 on 29 May 1943, but RO-107 was still active on 6 July 1943.)  

During World War II, 142 SC-497-class submarine chasers were lent to allies of the United States as part of the Lend-Lease program. Seventy-eight were sent to the Soviet Union, 50 to France, 8 to Brazil, 3 to Norway, and 3 to Mexico. The three Norwegian examples served with distinction on the Shetland bus service, running agents, refugees and weapons past the German blockade between occupied Norway and Britain.

Survivors
 (ex-USS SC-718) is preserved at the Royal Norwegian Navy Museum. Some remains of  (ex-USS SC-683) and  (ex-USS SC-1061) can be seen near the coast of Sweden.

See also
 
 
 List of patrol vessels of the United States Navy

References
Slingsby Capstan. The Slingsby T.49 Capstan is a British two-seat glider of the 1960s built by Slingsby Sailplanes as a replacement for their earlier Type 42 Eagle.

Design and development
The Capstan is a high-winged monoplane of wooden construction, the last two-seat wooden glider built by Slingsby, intended for both training and general club flying.  Side-by-side seats for the two pilots are accommodated in an enclosed cockpit with a one-piece perspex canopy.  The prototype T.49A first flew in 1961, and it entered production as the T.49B in 1963. Thirty-four Capstans were built, one of which was fitted with an auxiliary engine with the designation T.49C Powered Capstan.

Specifications

See also
List of gliders

Notes

References
"Two New Sailplanes". Flight International, 31 May 1962.pp. 867–869.
Taylor, J.W.R (ed.) Jane's All The World's Aircraft 1969–70. London:Sampson Low, 1969.
Slingsby Sailplanes Capstan T49 Handbook, 1963

External links

Photos of Slingsby Capstan
Slingsby Capstan Pictures

1960s British sailplanes
Glider aircraft
Capstan
Aircraft first flown in 1961
High-wing aircraft
Chūshi Powerline Crossing. The Chūshi Powerline Crossing is a part of the , a 220 kV powerline in Japan. It has two circuits running over the Inland Sea from Takehara. It was built in 1962 and consists of two towers, each 226 metres tall, one situated in Takehara, Honshū at , the other on the island of Ōkunoshima at . These towers are the tallest electricity pylons in Japan and carry six conductors arranged in three levels. The span between the two towers has a length of 2,357 metres and has a minimum clearance of 42 metres. The conductors have a cross section of 170 mm2, a diameter 35.2 mm and are designed for a maximum current of 645 A.

See also 
 Osaki Channel Crossing

External links 
 https://web.archive.org/web/20090224150653/http://www015.upp.so-net.ne.jp/overhead-TML/historicalline.htm

Towers in Japan
Electric power infrastructure in Japan
Pipe-laying ship. A pipelaying ship is a maritime vessel used in the construction of subsea infrastructure. It serves to connect oil production platforms with refineries on shore. To accomplish this goal a typical pipelaying vessel carries a heavy lift crane, used to install pumps and valves, and equipment to lay pipe between subsea structures.

Lay methods consist of J-lay and S-lay and can be reel-lay or welded length by length. Pipelaying ships make use of dynamic positioning systems or anchor spreads to maintain the correct position and speed while laying pipe.

Recent advances have been made, with pipe being laid in water depths of more than .

The term "pipelaying vessel" or "pipelayer" refers to all vessels capable of laying pipe on the ocean floor. It can also refer to "dual activity" ships. These vessels are capable of laying pipe on the ocean floor in addition to their primary job. Examples of dual activity pipelayers include barges, modified bulk carriers, modified drillships, and semi-immersible laying vessels, among others.

A number of national oil companies own and operate pipe laying barges for offshore oil projects. HYSY 202 was the first pipelaying barge to be built in China.

See also

Notes

References 
A.C. Palmer, R.A. King (2008) Subsea Pipeline Engineering, PennWell Books.

 
Ship types
Almaty University of Power Engineering and Telecommunications. Almaty University of Power Engineering and Telecommunications (AUPET) (Kazakh: Алматы Энергетика және байланыс университеті) is a technical engineering university in Almaty, Kazakhstan. It is located at 126 Baitursynov Street in Almaty and has around 4,000 students. It is one of the best-known universities in the field of power engineering and telecommunications in the Central Asian region. Students from all over central Asia study there. They live in three campuses with Wi-Fi internet access, video cassette record, online library and recreation facilities.

AUPET is building a third educational case with a new modern athletic field. Undergraduate students can receive a second bachelor's degree in economics from the Moscow Power Engineering Institute simultaneously with studying at AUPET.

Faculties
AUPET has four full-time faculties:
 Power engineering
 Electrical engineering
 Telecommunications
 Information Technologies

References

External links
Official website 

Education in Almaty
Universities in Kazakhstan
Sethi-Skiba point. Sethi-Skiba points, also known as DNSS points, arise in optimal control problems that exhibit multiple optimal solutions. A Sethi-Skiba point is an indifference point in an optimal control problem such that starting from such a point, the problem has more than one different optimal solutions. A good discussion of such points can be found in Grass et al.

Definition 
Of particular interest here are discounted infinite horizon optimal control problems that are autonomous. These problems can be formulated as

 

s.t.

 

where  is the discount rate,  and  are the state and control variables, respectively, at time , functions  and  are assumed to be continuously differentiable with respect to their arguments and they do not depend explicitly on time , and  is the set of feasible controls and it also is explicitly independent of time . Furthermore, it is assumed that the integral converges for any admissible solution . In such a problem with one-dimensional state variable , the initial state  is called a Sethi-Skiba point if the system starting from it exhibits multiple optimal solutions or equilibria. Thus, at least in the neighborhood of , the system moves to one equilibrium for  and to another for . In this sense,  is an indifference point from which the system could move to either of the two equilibria.

For two-dimensional optimal control problems, Grass et al. and Zeiler et al. present examples that exhibit DNSS curves.

Some references on the applications of Sethi-Skiba points are Caulkins et al., Zeiler et al., and Carboni and Russu

History 
Suresh P. Sethi identified such indifference points for the first time in 1977. Further, Skiba, Sethi, and Deckert and Nishimura explored these indifference points in economic models. The term DNSS (Deckert, Nishimura, Sethi, Skiba) points, introduced by Grass et al., recognizes (alphabetically) the contributions of these authors. These indifference points have been also referred to as Skiba points or DNS points in earlier literature.

Example 
A simple problem exhibiting this behavior is given by   and . It is shown in Grass et al. that  is a Sethi-Skiba point for this problem because the optimal path  can be either  or . Note that for , the optimal path is  and for , the optimal path is .

Extensions 
For further details and extensions, the reader is referred to Grass et al.

References

Optimal control
Mathematical economics
George Kemp. George Kemp may refer to:
 George Kemp (baseball), American baseball player
 George Stephen Kemp, electrical engineer and assistant to Guglielmo Marconi
 George Meikle Kemp (1795–1844), Scottish carpenter/joiner, draughtsman, and self-taught architect
 George Kemp, 1st Baron Rochdale (1866–1945), British aristocrat
 George Hubert Kemp (1897–1918), World War I British flying ace

See also
George Kempe
John Killefer. John Killefer (May 24, 1833 – July 1926) was a businessman and inventor. He apprenticed for two years as a blacksmith beginning in 1850, then moved to southern California and bought an orange grove. He soon noticed the phenomenon referred to as hardpan (the creation of a water resistant soil layer). Sometime in 1892 he designed and created the chisel plough for land tilling to prevent or defeat hardpanning. He founded Killefer Manufacturing Company in 1893 in San Bernardino, California. He relocated his company to Palmetto Street, Los Angeles, California in 1895 to lower overhead costs for the production of his plow. His son took over the company before it was sold to Deere & Company in 1937.

References

1833 births
1926 deaths
American businesspeople
1990 in spaceflight. The following is an outline of 1990 in spaceflight.

Launch of Hubble Space Telescope

Launches

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Deep-space rendezvous

EVAs

See also

Footnotes

 
Spaceflight by year
Scott C. Donnelly. Scott C. Donnelly (born 1961) is the CEO of Textron.  Before joining Textron, Donnelly was the CEO for General Electric Aviation, a producer of jet engines for commercial and military aircraft.  Donnelly also served as the Senior Vice President of General Electric Global Research, one of the world's largest industrial research organizations and held various management positions since joining General Electric in 1989.

Donnelly joined GE in 1989 as manager of Electronics Design Engineering for GE's Ocean Systems Division in Syracuse, New York. He went on to serve in a variety of leadership roles for the company, including engineering management positions with then-GE division of Martin Marietta in both Australia and the United States. In 1995, he moved to GE's Industrial Control Systems business, where he held various management positions. Donnelly was named a vice president of GE in 1997, responsible for Global Technology Operations at GE Healthcare.

Donnelly joined Textron in July 2008 as executive vice president and chief operating officer (COO) as part of a multi-year succession plan. On December 1, 2009, Lewis B. Campbell retired as CEO of Textron. He was succeeded as CEO by Donnelly. Donnelly was named chairman of the board on September 1, 2010.

Donnelly serves on several Engineering advisory committees including that of Cornell and Stanford Universities.

References

Living people
1961 births
American chief executives of manufacturing companies
Textron
American chief operating officers
Place of birth missing (living people)
20th-century American businesspeople
21st-century American businesspeople
Martin Marietta people
Hooghly River Bridge Commissioners. The Hooghly River Bridge Commissioners (HRBC) office is a statutory organization under the Department of Transport (West Bengal), established in 1969 for the construction of Vidyasagar Setu. 

In 1961, the Kolkata Metropolitan Planning Organization was set up through a resolution of the Development and Planning Department to develop a comprehensive development plan for the Metropolis, then called Calcutta. It was the first of its kind in India.

HRBC became the main body employed by the state government for complex civil engineering projects in urban locales in Kolkata. It is the principal body charged with the maintenance of the four flyovers across the city that serve as major traffic arteries.

An abandoned 14-floor skyscraper belonging to the HRBC in the Mandirtala neighborhood of Howrah was turned into the state secretariat of the Government of West Bengal and named as Nabanna. It continued to house the majority of state government departments and offices of the Chief Minister of West Bengal as of August, 2019.

Projects

 Vidyasagar Setu: the second bridge across the Hooghly river, which was inaugurated in 1992. It remains the longest cable-stayed bridge in India.

 Calcutta Infrastructure Development Projects: projects of the Government of West Bengal. Using international development loans, this project improved traffic speed by easing congestion at important critical junctions across Kolkata.

 Flyovers: At least four flyovers,  including the flyovers at major city roads like AJC Bose Road, Gariahat, and Park Street.

 Shyambazaar Crossing: improved major at-grade traffic junctions, most notably renewal of the historic Shyambazar 5-point crossing.

 Concretization of Tram tracks: upgraded Kolkata's tram tracks through the concretization of pavement.

References

State agencies of West Bengal
ANUSAT. The Anna University Satellite, or ANUSAT was an Indian student research microsatellite designed, developed and integrated at Aerospace Engineering, Madras Institute of Technology (MIT), Chromepet, Anna University. Students and faculty members of Madras Institute of Technology and College of Engineering, Guindy were involved in the design of ANUSAT. The project director of the ANUSAT was Dr. P. Dhanraj, CASR, Madras Institute of Technology, Chromepet. It carries an amateur radio and technology demonstration experiments. It was successfully Integrated at the clean room facility at MIT, Chrompet, Chennai and launched aboard a PSLV-CA designated PSLV-C12, along with RISAT-2, from the Second Launch Pad at the Satish Dhawan Space Centre. The launch was carried out at 01:15 GMT (06:45 IST) on 20 April 2009.

The satellite's development was sponsored by the Indian Space Research Organisation, who were also responsible for launch services.

ANUSAT was a cube with  long sides, and a mass of . It carried an amateur radio store and forward communications system, and also conducted technological research. This satellite was spin stabilized and spin axis is pointed normal towards the Sun. The satellite was integrated and tested at MICSAT, the MIT Chromepet clean room.

As on January 9, 2012, ANUSAT completed 15287 orbits around the Earth thereby exceeding its intended mission life of two years.

References

http://mitindia.edu/en/phd-research/electronics
http://mitindia.edu/en/103-mitindia/departments/aerospace/aero-staff/438-prof-r-dhanaraj

External links
AIAA IEEE Research article
ANUSAT Webpage

Student satellites
Students in India
Spacecraft launched in 2009
Spacecraft which reentered in 2012
Satellites of India
Amateur radio satellites
2009 in India