omniomni/omni-engineering huggingface dataset:
Biological screw joint. The biological screw joint is a naturally occurring form of the screw joint, a mechanical device that combines rotational movement with single-axis translation. Alexander Riedel of the State Museum of Natural History Karlsruhe and Thomas van de Kamp of the Karlsruhe Institute of Technology discovered it in specimens of Trigonopterus oblongus, a weevil found in Papua.

Discovery
Anatomical examination was made for specimens of the weevil species Trigonopterus oblongus, provided by the Karlsruhe State Museum of Natural History, using a microtomograph at the Institute of Synchrotron Radiation (ANKA) of Karlsruhe Institute of Technology. The analysis revealed that the weevils had a nut-and-screw system for the hip-leg joint.

Mechanism

The mechanism has been described as "rotational movement combined with a single-axis translation".

The arthropod hip–leg joint consists of two parts – the coxa (or the hip) and the trochanter (or the head of the arthropod leg femur). The coxa, in the case of weevils, resembles a nut, and it has a thread running along its inner surface with an angular span of 345°. The trochanter resembles the screw. It is rod-shaped with a large external spiral flange, having an angular span of 410°, in excess of a full circle, which functions as a thread. When the leg muscles of a beetle are stretched, the screw turns. Though the screw-thread provide for very large angular rotation, the front legs of weevils are capable of rotating by 90°, while their hind legs can rotate by 130°.

The weevils are just  long and can fold their legs below their body. The joint is just  in size. Before this was discovered, all known hip-leg joints have been based on either the ball and socket joint system for hip-leg connections, as in humans, as hinges or as saddle joints. The discovery is the first ever instance of a musculoskeletal nut-and-screw system in the animal kingdom.

Evolution
The screw-and-nut system has been found to be present in all 15 weevils examined by the scientists and appears to be a hitherto unknown anatomical feature of weevils. It has been estimated that weevils evolved this system about 100 million years ago. It is surmised that the development of this feature provided additional flexibility which permitted weevils to improve their climbing abilities, keep steady when at rest, and have stronger leverage for piercing by the snout.

See also
Issus, one of many planthoppers that have a "biological gear" mechanism in the nymph stage

References

Cryptorhynchinae
Insect anatomy
Terreplein. In fortification architecture, a terreplein or terre-plein is the top, platform, or horizontal surface of a rampart, on which cannon are placed, protected by a parapet. In Martello towers, the roof or terreplein was sometimes surmounted with one or two cannon mounted on a gun platform with a central pivot, that enabled the guns to traverse up to 360 degrees.

In civil engineering works, a terreplein is an embankment of earth with a broad level top, which is sometimes excavated to form a continuation of an elevated canal across a valley.

Notes and references 

Fortification (architectural elements)
Lioré et Olivier 300. The Lioré et Olivier 300 (abbreviated to LeO 300) was a 1930s French prototype night bomber. Only one was built when the programme was abandoned.

Design and development
The LeO 300 was designed to meet a French requirement for a BN.5 category night bomber. It was a high-wing cantilever monoplane with a crew of five. The prototype first flew in September 1933, powered by four  Renault 12Jb engines mounted in tandem pairs on the wings. The LeO 300 was superseded by the LeO 301 with more powerful engines but with the withdrawal of the requirement it was abandoned in final assembly and work on the programme was stopped.

Variants
LeO 300
Prototype four-engine night bomber, one built.
Leo 301
Improved variant with more powerful engines, not completed.

Specifications

Notes

Bibliography
 Hartmann, Gérard. Les Avions Lioré et Olivier. Boulogne-Billancourt, France: ETAI. 2002.  (in French)
 

1930s French bomber aircraft
300
High-wing aircraft
Four-engined push-pull aircraft
Aircraft first flown in 1933
Ligand efficiency. Ligand efficiency is a measurement of the binding energy per atom of a ligand to its binding partner, such as a receptor or enzyme.

Ligand efficiency is used in drug discovery research programs to assist in narrowing focus to lead compounds with optimal combinations of physicochemical properties and pharmacological properties.

Mathematically, ligand efficiency (LE) can be defined as the ratio of Gibbs free energy (ΔG) to the number of non-hydrogen atoms of the compound:

LE = -(ΔG)/N

where ΔG = −RTlnKi and N is the number of non-hydrogen atoms. It can be transformed to the equation:

LE = 1.4(−log IC50)/N

Other metrics 

Some suggest that better metrics for ligand efficiency are 
percentage/potency efficiency index (PEI), binding efficiency index (BEI) and surface-binding efficiency index (SEI) because they are easier to calculate and take into account the differences between elements in different rows of the periodic table. It is important to note that PEI is a relative measure for comparing compounds tested in the same conditions (e.g. a single-point assay) and are not comparable at different inhibitor concentrations. Also for BEI and SEI, similar measurements must be used (e.g. always using pKi).

PEI = (% inhibition at a given compound concentration as fraction: 0 – 1.0) / (molecular weight, kDa)
BEI = (pKi, pKd, or pIC50) / (molecular weight, kDa)
SEI = (pKi, pKd, or pIC50) / (PSA/100 Å)

where pKi, pKd and pIC50 is defined as −log(Ki), −log(Kd), or −log(IC
50), respectively. Ki and IC50 in mol/L.

The authors suggest plotting compounds SEI and BEI on a plane and optimizing compounds towards the diagonal and so optimizing both SEI and BEI which incorporate potency, molecular weight and PSA.

There are other metrics which can be useful during hit to lead optimization: group efficiency (GE), lipophilic efficiency/lipophilic ligand efficiency (LipE/LLE), ligand lipophilicity index (LLEAT) ligand efficiency dependent lipophilicity (LELP), fit quality scaled ligand efficiency (LEscale), size independent ligand efficiency (SILE).

Group efficiency (GE) is a metric used to estimate the binding efficiency of groups added to a ligand. Unlike ligand efficiency which evaluates the efficiency of the entire molecule, group efficiency measures the relative change  of the Gibbs free energy (ΔΔG), caused by addition or modification of groups, normalized by the change in the number heavy atoms in those groups (ΔN), using the equation:

GE = -(ΔΔG)/ΔN

See also 
 Drug design
 Drug discovery hit to lead

References 

Drug discovery
Medicinal chemistry
List of terrestrial fibre optic cable projects in Africa. This is a list of terrestrial fibre optic cable projects in Africa. While submarine communications cables are used to connect countries and continents to the Internet, terrestrial fibre optic cables are used to extend this connectivity to landlocked countries or to urban centers within a country that has submarine cable access. In most of the world, a large number of such cables exist, often amounting to robust Internet backbones. The lack of such high-speed cables poses a great problem for most African countries. The construction of both submarine cables and their terrestrial extensions is thus considered an important step to economic growth and development to many African countries.

Countries

Algeria

Angola

Benin

Botswana

Burkina Faso

Burundi

Cameroon

Chad

Cote d'Ivoire

Democratic Republic of Congo

Djibouti

Egypt

eSwatini

Ethiopia

Gambia

Ghana

Guinea

Kenya

Liberia

Madagascar

Malawi

Mali

Mauritania

Morocco

Mozambique

Namibia

Niger

Nigeria

Rwanda

Senegal

Somalia

South Africa

South Sudan

Sudan

Tanzania

Togo

Uganda

Zambia

Zimbabwe

Notes 
This list was initially developed as part of AfTerFibre, a project to map terrestrial fibre optic cable projects in Africa. The project was sponsored by Google Africa and, on completion, will be hosted by the UbuntuNet Alliance. All information gathered by the project will be publicly available under an open license.

See also 
 List of international submarine communications cables
 Central African Backbone
 Kenya Data Networks
 Telecommunications in Namibia
 Internet in Ethiopia
 People's Republic of China – Ghana relations

References

External links 
 AfTerFibre Google Group
 AfTerFibre Map
 Greg's Cable Map
 African Undersea Cables

 
Optical telecommunications cables
Thomson MO6. The Thomson MO6 was a Motorola 6809E-based computer introduced in France in 1986. It was intended as the successor to the Thomson MO5 and featured 128 KB of RAM, a  text display, and a new built-in Microsoft BASIC interpreter (BASIC 128). It retained compatibility with its predecessor, while incorporating the same technology as the TO8. 

Graphic abilities were expanded compared to the MO5, by the use of the Thomson EF9369 graphics chip. The 16 colour palette could be defined from a total of 4096 colours and extra video modes were available:

  colours with 3 transparency levels
  colours
 colours (allows shifting between two screen pages)
 colours and one transparency level
 colours
 colours (2 colours per  pixels restraint)
 colours

In Italy it was sold by Olivetti with minor aesthetic changes, and named Olivetti Prodest PC128. Twenty-one games were released for the MO6. The machine was available until January 1989.

References

External links
DCMOTO: PC emulator for Thomson MO5, MO5E, MO5NR, MO6, T9000, TO7, TO7/70, TO8, TO8D, TO9, TO9+ and Olivetti Prodest PC128. Comprehensive software and documentation are also available.

Personal computers
6809-based home computers
Thomson computers
Computer-related introductions in 1986
Uniformity tape. Uniformity tape is a microstructured thin-film mechanism for mixing and diffusing the light generated by light-emitting diodes (LEDs) in edge-lit digital displays, including computer monitors, televisions and signage.

Purpose 

Compared to other sources of illumination, such as fluorescent and incandescent bulbs, LEDs are energy efficient and increasingly inexpensive. As hard-point light sources, however, LEDs have several significant limitations in edge-lit digital displays.  First, the light generated by LEDs must be spread evenly to all parts of the display by a light guide (typically a plate of poly(methyl methacrylate)), which transports light by total internal reflection. Extraction patterns on the surface of the light-guide help to distribute the light evenly. However, even with a light guide, dark zones can be noticeable along the injection edge closest to the LEDs. The more widely spaced the LEDs are, the more pronounced the dark zones, but closely packed LEDs are less energy-efficient and can create thermal management issues. Dark zones can be camouflaged by a border or bezel, but this limits design options and the space available for displaying information.

Uniformity tape is designed to be applied directly to the injection edge of a light guide for the purpose of defusing the light generated by LEDs. The microstructure consists of 12-50 μm linear aspheric prisms aligned perpendicular to the plane of the guide. Since the microstructure is small compared to the spacing of the LEDs, no registration of the tape with the LEDs is required.

Research conducted by 3M indicates that the tape enables a 50 percent reduction in LED count with little effect on overall system efficiency. Injection losses can be as low as 1-2 percent with a properly designed light guide. Additionally, when applied to the input edge of the light guide, the optically clear adhesive will wet out and conform to the surface roughness of the light guide edge, meaning that the PMMA plate does not require the level of polishing required in a conventional light guide.

See also 
 Backlight
 Poly(methyl methacrylate)
 Total internal reflection

References 

Optical materials
Light-emitting diodes
Embedded C. Embedded C is a set of language extensions for the C programming language by the C Standards Committee to address commonality issues that exist between C extensions for different embedded systems.  

Embedded C programming typically requires nonstandard extensions to the C language in order to support enhanced microprocessor features such as fixed-point arithmetic, multiple distinct memory banks, and basic I/O operations. The C Standards Committee produced a Technical Report, most recently revised in 2008 and reviewed in 2013, providing a common standard for all implementations to adhere to. It includes a number of features not available in normal C, such as fixed-point arithmetic, named address spaces and basic I/O hardware addressing. Embedded C uses most of the syntax and semantics of standard C, e.g., main() function, variable definition, datatype declaration, conditional statements (if, switch case), loops (while, for), functions, arrays and strings, structures and union, bit operations, macros, etc.

References

C (programming language)
C programming language family
Embedded systems
Kestrel KL-1. The Kestrel KL-1 is an American single-engined four-seat utility aircraft designed and built in the 1990s by the Kestrel Aircraft Company of Norman, Oklahoma.

Design and development
The KL-1 is a composite fuselage cantilever high-wing cabin monoplane designed to meet the requirements of the utility and normal categories of Part 23 of the Federal Aviation Regulations. It had a fixed tricycle landing gear and a conventional four-seat cabin layout. The prototype designated KL-1A and registered N960KA first flew on 19 November 1995 and was powered by a  Lycoming O-320-D2G piston engine driving a two-bladed fixed pitch propeller. 

A number of improved variants of the KL-1 were planned including an armed observation or forward air control version with underwing weapon pylons. 

While the prototype was test flying to gain certification the programme was abandoned.

Variants
KL-1A
Baseline four-seat production variant with a  Lycoming O-320-D2G piston engine, one built.
KL-1B
Proposed de-luxe four-seat variant with a  Lycoming IO-360-ES piston engine, not built.
KL-1C
Proposed high-performance variant with a  Continental TSIO-360C piston engine, 2 built.
KL-1D
Proposed six-seat utility and cargo variant with a  Continental TSIO-550-B engine,  and an optional floatplane conversion, not built.
KL-1R
Proposed retractable landing gear variant of the KL-1B with a  Lycoming IO-360-ES piston engine, not built.
K250A
Proposed military armed observation or forward area control variant of the KL-1C with additional observation windows and underwing weapons pods, not built.

Specifications (KL-1A)

See also

References

Notes

Bibliography

 

1990s United States civil utility aircraft
High-wing aircraft
Single-engined tractor aircraft
Aircraft first flown in 1995
Sripada Yellampalli Project. Sripada Yellampalli Project is an irrigation project located at Yellampalli Village of Ramagundam rural Mandal, between Peddapalli district - Mancherial District of Telangana State, India. The project is fourth largest on the Godavari River in Telangana State. It is named after late legislator, D. Sripada Rao.

Project info
Sripada Yellampalli irrigation project foundation was laid by Former Chief Minister of Andhra Pradesh, Y. S. Rajasekhara Reddy on 28 July 2004.

The project is designed to utilize about 63 tmc of water at a cost of Rs. 900 crores in the first phase. In the second phase, about 49.5 tmc would be lifted to the upland regions of Karimnagar, Adilabad, Nizamabad, Warangal and Medak districts with 6 TMC water allotted for the NTPC Ramagundam project. After the flood gates are installed, the project could would store about 20 Tmcft of water.

The project operational requirement is 163 MW power and 469 million KWh of electrical energy annually to pump the water. The project would supply water for NTPC power project reservoir in Ramagundam Mandal in Karimnagar old district (Peddapalli district).
It commenced its operations in 2005 near Mamnoor and Yellampalli villages at Ramagundam and mainly supplies drinking water to Ramagundam, Godavarikhani cities and Hyderabad Capital city.

See also
 Sriram Sagar Project
 Medigadda Barrage
 Annaram Barrage
 Sundilla Barrage
 Lower Manair Dam
 Mid Manair Dam
 Kaddam Project
 Upper Manair Dam
 SRSP Flood Flow Canal
 Nizam Sagar
 Pranahita Chevella
 Alisagar lift irrigation scheme
 Maulana Abul Kalam Hyderabad Sujala Saravanthi scheme
 Sri Komaram Bheem Project
 Devadula lift irrigation scheme
 Icchampally Project

References

Dams on the Godavari River
Dams in Telangana
Irrigation in Telangana
Adilabad district
Karimnagar district
Godavari basin
Montana Coyote. 

The Montana Coyote is an American single-engined two-seat STOL aircraft designed for home building by Montana Coyote Inc. of Helena, Montana.

Design and development
The Coyote is a high-wing strut-braced monoplane first flown in early 1991 and sold as kit for home building without an engine. With a steel tube fuselage and wooden wings it is designed to take an engine between 100 and 200 hp (74 to 149 kW) as long as it weighs less than 350 lb (159 kg). It has a fixed tailwheel type landing gear with a cabin for a pilot and passenger side-by-side, it is designed to land and take-off within 350 ft (107 m).

Specifications

References

Notes

Bibliography

 

1990s United States civil utility aircraft
Homebuilt aircraft
Bureau of Engineer Surveyors. The Bureau of Engineering Surveyors is the professional sector of the Society of Operations Engineers (SOE) for Engineer Surveyors, but also allied professionals in building services and engineering safety. It was founded in 1965 and merged with other societies to form the SOE in 2000. Its members check machinery and fixed plant for safety, and for meeting legal requirements.

References
Bureau of Engineering Surveyors webpage

Professional associations based in the United Kingdom
Safety engineering organizations
Organizations established in 1965
1965 establishments in the United Kingdom
Goodyear Meteor Junior. The Goodyear Meteor Junior was a 1954 concept for a fully reusable spacecraft and launch system designed by Darrell C. Romick and two of his colleagues employed by Goodyear Aerospace, a subsidiary of the American Goodyear Tire and Rubber Company. Darrell Romick originally estimated that the craft would cost about the same as an intercontinental B-52 bomber.

Concept

The concept was introduced in 1954, before the dawn of human spaceflight, to be displayed at the annual conference of the American Rocket Society. The design called for a winged spacecraft piloted by a crew of three. The craft was to contain three stages, of which only the uppermost, containing the crew, would ultimately be propelled to orbit around Earth. Each of these three stages was to contain landing gear and a crew of its own, allowing the stages to be piloted to a landing to be reused in a future launch. For reentry and landing, the nose of each stage had a mechanism that would allow the nose to close into a point.

The craft would have been  long, and would weigh 500 tons. The craft itself would have been impractically massive for the time period; however, the design ignited public interest in that it was an early concept for a reusable vehicle to transport crew and cargo to space and back, and was the subject of an article in the December 1957 issue of Popular Science magazine.

The original concept envisioned the craft launching from the White Sands Missile Range. At a downrange distance of  and an altitude of , the first stage would separate from the craft. At  downrange, the second stage would separate at an altitude of . After launch was completed, the third stage/crew compartment would orbit the Earth at an altitude of  at a velocity of , where it would stay for approximately two months before returning to Earth.

References

1954 in spaceflight
Cancelled spacecraft
Goodyear Tire and Rubber Company
Spaceplanes
Reusable launch systems
Dart Cambridge. The Dart Cambridge was a single-seat competition sailplane built in the United Kingdom in the 1930s. A development of the Grunau Baby, only two were built, flying with gliding clubs.

Design and development
The Cambridge first appeared as the Zander and Weyl Cambridge, making its first flight a few months before Zander and Weyl Ltd. changed its name to Dart Aircraft Ltd. Like the Slingsby Kite 1, the Cambridge was an updated version of the successful and influential Grunau Baby. It retained the Baby wing with its thick, high lift airfoil, though slightly increased in span, introduced a smoother monocoque fuselage, a tailplane of greater span and a new rudder.

The wings of the Cambridge had a constant chord to about half span, outboard of which the leading edge was slightly swept and the trailing edge elliptically tapered. The ailerons were hinged on the outboard sections at a slight angle to the main spar, allowing them to be of almost constant chord.  No flaps or airbrakes were fitted.  The wings were mounted on a raised part of the fuselage just behind the cockpit, with single lift struts from the lower fuselage to the main spar at about one quarter span.  The revised tailplane had swept leading edges and the elevators had forward-swept trailing edges, as on the Baby, but their extended span made it more pointed in plan.  The fin was very narrow, with the rudder and elevator hinges at the same fuselage position.  The rudder was almost semi-circular.

The smooth plywood monocoque fuselage became more slender aft of the pylon carrying the wing.  The cockpit was open.  A combination of a single, short, fuselage-mounted skid and integral tail bumper served as an undercarriage.

The Cambridge first flew on 1 December 1935.  A second aircraft, known as the Cambridge 2, was a little lighter and had larger ailerons.

Operational history
The first Cambridge was owned by the Duke of Grafton, who was one of the founding members of the Cambridge University Gliding Club (CUGC).  It was flown as a club aircraft and was entered by them into the 1939 National Soaring Contests, though without making much impression.  It was registered by the club after World War II in the brief period from 1949 when UK gliders appeared on the CAA register.  It was de-registered by CUGC in 1953, by which time gliders no longer required CAA registration.  Its later history is uncertain; it was at RAF Dishforth for a while and may have been burnt before 1973.

The Cambridge 2 was operated by the London Gliding Club who flew it into 6th place in the 1937 National Competitions, though it gained no prizes.

Specifications (Cambridge I)

References

External links
Gōttingen 535 airfoil

1930s British sailplanes
Aircraft first flown in 1935
Rutilated quartz. Rutilated quartz is a variety of quartz which contains acicular (needle-like) inclusions of rutile. It is used for gemstones. These inclusions mostly look golden, but they also can appear silver, copper red or black. 

The inclusions may be distributed randomly or in bundles, which sometimes are arranged star-like, and they can be sparse or dense enough to make the quartz body nearly opaque. 

While otherwise inclusions often reduce the value of a crystal, rutilated quartz is valued for the quality of these inclusions.

See also
 Phantom quartz

References

Minerals
Dielectrics
Quartz varieties
Piezoelectric materials
Trigonal minerals
Luminescent minerals
Quartz gemstones