omniomni/omni-engineering huggingface dataset:
Octaazacubane. Octaazacubane is a hypothetical explosive allotrope of nitrogen with formula N8, whose molecules have eight atoms arranged into a cube. (By comparison, nitrogen usually occurs as the diatomic molecule N2.) It can be regarded as a cubane-type cluster, where all eight corners are nitrogen atoms bonded along the edges.  It is predicted to be a metastable molecule, in which despite the thermodynamic instability caused by bond strain, and the high energy of the N–N single bonds, the molecule remains kinetically stable for reasons of orbital symmetry.

Explosive and fuel
Octaazacubane is predicted to have an energy density (assuming decomposition into N2) of 22.9 MJ/kg, which is over 5 times the standard value of TNT. It has therefore been proposed (along with other exotic nitrogen allotropes) as an explosive, and as a component of high performance rocket fuel. Its velocity of detonation is predicted to be 15,000 m/s, much (48.5%) more than octanitrocubane, the fastest known nonnuclear explosive.

A prediction for cubic gauche nitrogen energy density is 33 MJ/kg, exceeding octaazacubane by 44%, though a more recent one is of 10.22 MJ/kg, making it less than half of octaazacubane.

See also
 Tetranitrogen (Nitrogen allotrope with formula N4)
 Hexazine (Nitrogen allotrope with formula N6)
 Pentazole
 1,1′-Azobis-1,2,3-triazole
 1-Diazidocarbamoyl-5-azidotetrazole

References

External links

Explosive chemicals
Hypothetical chemical compounds
Allotropes of nitrogen
SIP trunking. SIP trunking is a voice over Internet Protocol (VoIP) technology and streaming media service based on the Session Initiation Protocol (SIP) by which Internet telephony service providers (ITSPs) deliver telephone services and unified communications to customers equipped with SIP-based private branch exchange (IP-PBX) and unified communications facilities. Most unified communications applications provide voice, video, and other streaming media applications such as desktop sharing, web conferencing, and shared whiteboard.

Domains 
The architecture of SIP trunking provides a partitioning of the unified communications network into two different domains of expertise:
 Private domain: refers to a part of the network connected to a PBX or unified communications server.
 Public domain: refers to the part of the network which allows access into the public switched telephone network (PSTN) or public land mobile network (PLMN).

The interconnection between the two domains must occur through a SIP trunk. The interconnection between the two domains, created by transport via the Internet Protocol (IP), involves setting specific rules and regulations as well as the ability to handle some services and protocols that fall under the name of SIP trunking.

The ITSP is responsible to the applicable regulatory authority regarding all the following law obligations of the public domain:
 Tracking traffic;
 Identification of users;
 Implementation of the lawful interception mechanisms.

The private domain instead, by nature, is not subject to particular constraints of law, and may be either the responsibility of the ITSP, the end user (enterprise), or of a third party who provides the voice services to the company.

Architecture 
Each domain has elements that perform the characteristic features requested of that domain, in particular the result (as part of any front-end network to the customer) is logically divided into two levels:
 The control of access (Class 5 softswitch);
 Network-border elements that separate the Public Domain from the Private Domain, implementing all the appropriate ITSP phone security policies.

The private domain consists of three levels:

 corporate-border elements that separate the public domain from the private domain, implementing the appropriate company security policies
 central corporate switching node
 IP PBXs

See also 
 Trunking
 Session border controller (SBC)

References 

Telecommunication services
VoIP protocols
Burnelli CB-16. The Burnelli CB-16, also known as the Uppercu-Burnelli CB-300, was a passenger aircraft designed by the American company Burnelli in 1928. It was the first twin-engined aircraft to have retractable landing gear.  Only one was built.

Design and development

The CB-16 was built for and financed by Paul W. Chapman, chairman of Sky Lines Inc. in 1928, following the success of the Burnelli RB-2.

The CB-16 was a twin-engined high-wing monoplane, constructed of metal.  The slightly tapered wing was braced from the lower fuselage by pairs of parallel struts.  The fuselage was 36 ft (11 m) long and 12 ft (3.7 m wide) wide externally, with an airfoil cross section.  As with the earlier RB-1 and RB-2, the twin engines were embedded within the leading edge of the fuselage though, unlike them, the rest of this surface was largely filled with radiators. To reduce yaw after an engine failure, the 500 hp (370 kW) water cooled Curtiss Conqueror inline engines were mounted with slight toe out.  The internal dimensions of the cabin, which could seat 12-20 passengers, were 18 ft (5.49 m) by 11 ft 4 in (3.45 m) long, with a height of 5 ft 6 in (1.71 m). This provided both seating and lounge space.  At the rear of the cabin there was a small kitchen and toilets.  The pilots sat in open cockpits placed at the wing leading edge.

Earlier Burnelli lifting body designs had fuselages which were rectangular in plan, with the empennage directly attached, but the CB-16's fuselage tapered and the tail unit was mounted beyond the lifting body's trailing edge on a pair of thin panels extending from its sides. The alteration was motivated by the difficulties of pitch and yaw control encountered with the earlier arrangement.  The panels swept upwards into a pair of fins and balanced rudders carrying a high set tailplane with three balanced elevators, the rudders working between them. The single wheels of the still novel retracting undercarriage were mounted on V-struts hinged at the lower, outer fuselage, retracting inwards.

The completed aircraft was shipped to Newark, New Jersey. In January 1929 Leigh Wade piloted the aircraft on a 40-minute test flight. Further tests were then conducted at Curtiss Field at Long Island and Bolling Field in Washington. In 1929, during a test, the CB-16 stalled and crashed at takeoff, though the two pilots survived.

Specifications

Notes

References

.
AAHS journal, Volume 42. American Aviation Historical Society. 1997.

"Cutaway Drawing of Burnelli transport in flight" Popular Mechanics, December 1930

CB-16
1920s United States airliners
Lifting bodies
High-wing aircraft
Aircraft first flown in 1929
Twin piston-engined tractor aircraft
Bartlett L. Thane. Bartlett Lee "Bart" Thane (August 26, 1877 – November 7, 1927) was an American mining engineer who pioneered hydroelectric power in Juneau, Alaska. The world's first thin arch dam, Salmon Creek Dam, was constructed by Thane.

Early years
Thane was born in Oakland, California, USA, in August 1877.  His parents were Joseph E. Thane and Laura E. Thane.  His father was a well-known orchardist from Niles, California.  His maternal grandfather was Judge Harmon J. Tilden. Thane's sister was named Laura. He attended the University of California, Berkeley, where he graduated with a degree in mining engineering in 1899.  While attending the university, he played college football and was the quarterback of the 1898 California Golden Bears football team that defeated Stanford in the "Big Game" for the first time by a score of 22 to 0.  He was also a member of Skull and Keys and Kappa Alpha Order at Cal.

Career

Thane first came to Alaska in 1897.  He was hired by Herman T. Tripp to work at the Sumdum Chief Mine south of Juneau.  He was the first superintendent of the Eagle River Mining Company (1903-1910), before becoming Managing Director of the Alaska-Gastineau Mining Company. By 1911, he had controlling interest in six Juneau area gold mines. In 1912, he took control of the Perseverance Mine and developed it into the world's largest. With the assistance of his former college football friends, Thane constructed Salmon Creek Dam, the world's first thin arch dam, in 1914.

In 1915, Thane and other mining and business executives established Juneau's first golf course, in the Mendenhall Valley. Between 1918 and 1919, Thane quit the Alaska-Gastineau Mining Company, moved to San Francisco, and then returned to the Alaska-Gastineau Mining Company. In 1921, after the Alaska-Gastineau Mine shut down, Thane attempted to develop his facilities for a new pulp mill, but a deal with Japanese investors failed in 1923.

Personal life
In June 1902, Thane married Juliet Fay Blaine (born March 27, 1879) at Berkeley, California.  They lived in what was to become the Wickersham State Historic Site on Chicken Ridge in Juneau during the period of 1914-1916, along with their daughter, also named Juliet Fay Thane (born August 2, 1906 in Juneau).  Thane's sister Laura married James R. Whipple who became a business associate of Thane's.

In a Draft Registration Card completed in September 1918, Thane listed his permanent address as the Fairmont Hotel in San Francisco.  He identified himself as a mining engineer with an office at San Francisco's Crocker Building.  Also, in a 1923 passport application submitted of a trip to Japan, Korea, China and Australia, Thane listed San Francisco as his permanent residence.  Thane died in New York City in 1927. Thane, Alaska, and Thane Road, on the Gastineau Channel, were named in his honor.

References

1877 births
1927 deaths
People from Oakland, California
California Golden Bears football players
American mining engineers
Engineers from California
Schneider ES-60. 

The Schneider ES-60 Boomerang is a single-seat glider that was designed and manufactured in Australia in the 1960s. It is constructed of wood and fabric.  It was designed and manufactured by Edmund Schneider Pty of Adelaide, South Australia. It has a fixed main wheel and a tail skid. The Boomerang has an all-moving, swept tailplane that resembles a boomerang and hence the name given to the ES-60.  A version with a conventional straight stabiliser and moving elevator was also manufactured, called the ES-60B Super Arrow.

In the 1950s Edmund Schneider Pty Ltd manufactured a number of Schleicher Ka 6 gliders, under licence from Alexander Schleicher of Germany.  However, the Ka 6 with its low wing loading proved to be unsuited as a competition glider in Australia's strong summer thermal conditions. The Gliding Federation of Australia asked Edmund Schneider to design and manufacture a competition sailplane better suited to Australian conditions. The result was the ES-60 Boomerang.

Specifications

See also

Notes

References
Sailplane Directory. Schneider. Online. October 7, 2007.
 
 ES-60 Boomerang in Sailplane Directory

1960s Australian sailplanes
Glider aircraft
Edmund Schneider aircraft
Operational context. An operational context (OLC) for an operation is the external environment that influences its operation. For a mobile application, the OLC is defined by the combined hardware/firmware/software configurations of several appliances or devices, as well as the bearer of the mobiles of these units and other work position environment this person as the key stakeholder makes use of in timely, spatial and modal coincidence.

This concept differs from the operating context and does not address the operating system of computers.

Example 

The classic example is defined by the electronic leash configuration, where one mobile appliance is wirelessly tethered to another such appliance. The function of this electronic leash is to set an aural alarm with any of these two in case of unintentional leaving one of these two behind.

Implementing the example 

Several suppliers offer the electronic leash solution. A new aspect has been launched with Bluetooth low energy for better economised battery life cycle. Special trimming serves for two years operation from a button cell.

References

See also
 Context
 Operating context, the external environment that influences an operation;
 Unilateration

Wireless networking
LOFT. The Large Observatory for X-ray Timing (LOFT) is a proposed ESA space mission originally slated to launch around 2022, and now proposed to launch around 2025. The mission will be devoted to the study of neutron stars, black holes and other compact objects by means of their very rapid X-ray variability. LOFT is supported by a large international collaboration, led by researchers spread over most of the European countries, including Italy, Switzerland, Germany, Denmark, United Kingdom, Greece, Ireland, the Netherlands, Poland, Czech Republic, Spain, and with contributions from Brazil, Canada, Israel, United States and Turkey.  SRON Netherlands Institute for Space Research acts as principal investigator.

The mission was submitted to the ESA Cosmic Vision M3 call for proposals, and was selected, together with other three missions, for an initial Assessment Phase.

On February 19, 2014, the PLATO mission was selected in favour of the other candidates in the programme, including LOFT. In spite of this, LOFT has been submitted to the Cosmic Vision M4
call for proposals for a planned launch date of 2025, if selected.

Mission architecture 
The Large Observatory for X-ray Timing mission comprises two instruments.

 Large Area Detector (LAD), a 10 m2 collimated X-ray detector
 Wide Field Monitor (WFM), a coded-mask wide field X-ray monitor

The Large Area Detector (LAD) achieves an effective area of ~10 m2 (more than an order of magnitude larger than current spaceborne X-ray detectors, e.g. RXTE) in the 2-50 keV range, yet still fitting a conventional platform and small/medium-class launcher, thanks to the monolithic design of its large area Silicon Drift Detectors (SDD).

The Wide Field Monitor (WFM) is a coded mask X-ray monitor with a large field of view (observing about 50% of the sky available to the LAD at any time), and is also based on the Silicon Drift Detector technology. Its operating energy range is the same of the LAD, i.e. 2-50 keV.

Objectives 
The main scientific objectives of LOFT are:
 the determination of the neutron star structure and its equation of state
 the study of the physics in strong gravitational fields, e.g. in the accretion disks around black holes
 the direct measurements of black hole mass and spin

Besides these topics, LOFT will in general study the X-ray spectra and variability for a wide range of astrophysical sources, e.g. magnetars, active galactic nuclei, cataclysmic variables, X-ray transients and gamma-ray bursts.

The unique capabilities of LOFT, make this instruments certainly able to provide new breakthroughs in a wide range of Astrophysical research areas.

See also
 EChO
 MarcoPolo-R
 STE-QUEST
List of proposed space observatories

References

External links 
Four candidates selected for the next medium-class mission in ESA's Cosmic Vision
 
LOFT Supporters Newsletter 

European Space Agency satellites
Cancelled spacecraft
Space telescopes
X-ray telescopes
Cosmic Vision
Caproni Trento F-5. The Caproni Trento F.5 was a small Italian two-seat trainer designed by Stelio Frati and built by Aeroplani Caproni Trento.  The F.5 was not ordered into production and only a prototype was built.

Design and development
By the 1950s the Caproni company had collapsed and could not survive the postwar economic problems. One of the few group members to continue working was Aeroplane Caproni Trento, based at Gardola in Trento. Originally involved with aircraft maintenance and support, the company decided to design and build a small jet trainer in 1951. The F.5 aircraft was designed by Stelio Frati based on his earlier glider work. It was a low-wing all-wood monoplane with retractable tricycle landing gear. The engine was a small Turbomeca Palas turbojet located in the fuselage. It had two inlet ducts, one either side of the fuselage and the exhaust was below the rear fuselage. It had an enclosed cabin with tandem seating for an instructor and student and was fitted with a jettisonable canopy.

The F.5 made its maiden flight on 20 May 1952. It was the first jet aircraft developed in postwar Italy. Although evaluated by the Italian Air Force it gained little interest and was not ordered into production.

Operators

Italian Air Force one aircraft for evaluation test

Aircraft on display
The prototype, registered I-FACT, and only F.5 is on display at the Museo dell'Aeronautica Gianni Caproni in Trento.

Specifications

References

Notes

Bibliography

  

Caproni aircraft
1950s Italian military trainer aircraft
Low-wing aircraft
Single-engined jet aircraft
Aircraft first flown in 1952
Professional Engineers of Bangladesh. The Board of Professional Engineers of Bangladesh (BPERB) was established on 11 January 2001 by an amendment to the constitution of the Institution of Engineers, Bangladesh and exists as an autonomous body with its own Board of Executives independent of IEB. The organization consists of various engineers and other professions.

Registration into the National Database of Licensed Engineers (Bangladesh) require sponsorship from three Fellows of IEB.

BPERB maintains established standards that need to be individually achieved by prospective engineers before being registered as a licensed engineer in Bangladesh. It adds the post-nominal title of PEng. It requires corporate membership, 7 years of full-time post graduate work experience and satisfaction of training objectives and testings as set by rule. The license also requires Continuing Professional Development (CPD) to maintain a license.

External links
 BPERB official website

Science and technology in Bangladesh
3-pronged parts retriever. A 3-pronged parts retriever, also known as a Pearl-Catcher, is a tool used by computer technicians.

Design
It consists of a length of tube of around 4 mm to 6 mm in diameter, often made of coiled steel springs, with a push-button on one end. Three metal wires protrude from the other end, each sprung to bend outwards, away from the tube's axis, but with their tips bent inwards to form teeth. The push-button drives the wires down the tube, where their natural springiness causes them to spread further outwards, opening the teeth. When the button is released, an internal spring withdraws the wires which, constrained by the tube, are forced together, closing the teeth.

By pressing the end of it, the user allows the teeth to open up and by releasing their hold, the teeth will grab whatever object is below the grabber.

They mainly come in sizes ranging from about 4 to 9 inches. The outer shell is usually plastic, although higher end retrievers can have metal casing and reinforced inner material.

Use
The tool is mainly used to retrieve screws, although is also helpful in retrieving jammed bits in the motherboard.
                                                                 
Other uses include paper removal, device handling, and item maneuvering.

References

Lifting equipment
New Ditch. New Ditch is a linear earthwork of possible Iron Age or Medieval construction. It partially crosses the Polden Hills in woodlands approximately  south-west from the village of Butleigh in Somerset, England.

Its construction is similar to Ponter's Ball Dyke 3 miles to the northeast, with the dyke on the south east of the embankment, but of less massive construction. Both were probably part of a more extensive defence scheme. It is nearly half a mile in length and was probably of greater extent originally, but as it stands, New Ditch cannot be termed a cross-ridge dyke although it does seem to be a boundary work.

It is debatable whether this site is ancient because it is located close to a medieval woodland and a deer park.

References

Archaeological sites in Somerset
Iron Age sites in Somerset
Linear earthworks
HG Matthews Brickworks. HG Matthews Brickworks was founded in 1923 by Henry George Matthews and has since been run by his family. It is now managed by his Grandson Jim Matthews. The Matthews brick can be seen in many of the houses in South Buckinghamshire. Almost all new build homes in the Chiltern (district) Council area are built of bricks from this small Brickyard. The firm specialises in traditional brickmaking.

In 2010 Matthews started building a Wood Burning Kiln the aim of which has been to reduce the company's reliance on oil as fuel.

HG Matthews is the largest employer in the village of Bellingdon.

References

Manufacturing companies established in 1923
Companies based in Buckinghamshire
Brick manufacturers
1923 establishments in England
Brickworks in the United Kingdom
Building materials companies of the United Kingdom
White River Bridge. The White River Bridge was built in 1929 in Mount Rainier National Park as part of the Yakima Park Road project. The new road was planned to open up access to the northeastern portion of the park. The bridge, spanning the White River, was built by contractor John D. Tobin of Portland, Oregon, who had previously built the Narada Falls Bridge and the Christine Falls Bridges, both listed on the National Register of Historic Places. Plans for the bridge were drawn by the National Park Service Branch of Plans and Designs in the National Park Service Rustic style, with construction supervision by NPS landscape architect Ernest A. Davidson. The three-centred arch spans , with a stone-faced concrete structure.

The bridge was placed on the National Register of Historic Places on March 13, 1991. It is part of the Mount Rainier National Historic Landmark District, which encompasses the entire park and which recognizes the park's inventory of Park Service-designed rustic architecture.

See also
List of bridges documented by the Historic American Engineering Record in Washington (state)

References

External links

Bridges completed in 1929
Road bridges on the National Register of Historic Places in Washington (state)
Bridges in Pierce County, Washington
Civilian Conservation Corps in Washington (state)
Buildings and structures in Mount Rainier National Park
National Park Service rustic in Washington (state)
Historic American Engineering Record in Washington (state)
National Register of Historic Places in Mount Rainier National Park
Arch bridges in the United States
Concrete bridges in the United States
1929 establishments in Washington (state)
Strategemata. Strategemata, or Stratagems, is a Latin work by the Roman author Frontinus (c. 40 – 103 AD). It is a collection of examples of military stratagems from Greek and Roman history, ostensibly for the use of generals.  Frontinus is assumed to have written Strategemata towards the end of the first century AD, possibly in connection with a lost work on military theory.

Frontinus is best known as a writer on water engineering, but he had a distinguished military career. In Stratagems he draws partly on his own experience as a general in Germany under Domitian.  However, most of the (more than five hundred) examples which he gives are less recent, for example he mentions the Siege of Uxellodunum in 51 BC. Similarities to versions in other Roman authors like Valerius Maximus and Livy suggest that he drew mainly on literary sources.

The work consists of four books, of which three are undoubtedly by Frontinus. The authenticity of the fourth book has been challenged.

Editions

References

External sources 
 Strategemata 
 Frontinus: The man and the works (LacusCurtius website): this source provides the Latin text and the English translation from the 1925 Loeb edition.

Military books in Latin
Military strategy books
1st-century books in Latin