omniomni/omni-engineering huggingface dataset:
Arrábida Bridge. The Arrábida Bridge is an arch bridge of reinforced concrete which carries six lanes of traffic over the Douro River, between Porto and Vila Nova de Gaia, in the Norte region of Portugal.

History

In March 1952, a preliminary project for a roadway bridge was adjudicated to Professor Edgar António Mesquita Cardoso, by the JAE. It was approved in 1955.

The construction of the bridge proceeded in May 1957. By decree 42/234, dated 22 April 1959, the Ministério das Obras Públicas (Public Works Ministry) promoted, through their respective City Councils, the construction of modest dwellings for the accommodation of families who needed to be demolished, as a result of the construction of access to the bridge. By 22 June 1963, the bridge was concluded and inaugurated. At the time of its completion, the bridge's main span of  was the largest of any concrete-arch bridge in the world.

In the 1990s, the elevators on the bridge were deactivated.

A process to classify the bridge began on 16 February 2011. An announcement was issued on 18 September 2012 (13409/2012) on the project to classify the bridge as a Monumento Nacional (National Monument), establishing its respective Special protection Zone.

On 24 June 2016, a tourist experience that allowed pedestrians to walk across the archway, an idea of Pedro Pardinhas, who invested 50,000 euros and safety equipment and transformation of a small annex as the reception hall for "Porto Bridge Climb".

Architecture

The bridge is isolated over the Douro river, supported over the northern margin along the Arrábida escarpment and along the southern margin at ravine in the area of Candal. It is implanted downstream from the D. Luís Bridge, and is the closest to the mouth of the Douro  River, establishing a connection between the IC1 (in Vila Nova de Gaia) and Porto beltway (VCI).

The structure is an iron, archway bridge, constructed of reinforced concrete, asphalt deck. The deck is supported by a dual archway, united by corner narrow elements in concrete crosses. There are 76 pillars, with the largest four located near the main supports, near the massive rectangular columns, with smaller pillars regularly spaced along the exterior surfaces. These larger columns have elevators that link the deck level to the marginal roadway along the Douro. The elevator volumes, facing the interior of the bridge, include addorsed sculptures. The deck includes six lines of traffic for vehicular traffic (part of the European route E01 system) and two narrower lines for pedestrian passage.

The total length of the deck is  with a width of  The arch has a rise of , and the maximum clearance above river level is  above the Douro. The cost of construction was 126 million escudos.

References

Notes

Sources

External links 

 Arrábida Bridge on bridge-info.org

Bridges completed in 1963
Bridges in Porto
Bridges in Vila Nova de Gaia
Bridges over the Douro River
Deck arch bridges
Concrete bridges
National monuments in Porto District
Listed bridges in Portugal
SPH. SPH may refer to:

 School of Public Health (Imperial College London)
 Rutgers School of Public Health
 Sekolah Pelita Harapan, schools in Jakarta, Indonesia
 Shanghai Pharmaceuticals
 Shepherds Well railway station, Kent, England (National Rail station code SPH)
 Singapore Press Holdings
 SPH Media
 SPH MediaWorks
 Small penis humiliation
 Smoothed particle hydrodynamics
 Sphingomyelin
 Self-propelled howitzer, a type of self-propelled artillery
Mars Microspacecraft Missions. Mars Microspacecraft Missions are proposed cheap launch missions costing less than $50 million that can be carried out by the Italian Space Agency to Mars to research Mars, ranging from the use of one spacecraft to multiple constellations of mini spacecraft.

Under a study contract, the Italian Space Agency (ASI) developed the mechanical system concept for a Mars Microspacecraft to launch in a twin configuration on an Ariane V ASAP (Auxiliary Payload). As a member a multi-disciplined team, ASI developed the mechanical configuration and preliminary structure design for the spacecraft in two configurations, a probe carrier and an orbiter. The term microspacecraft was used in a Jet Propulsion Laboratory publication in 1981.

References

	

Hypothetical spacecraft
Comp Air Jet. The Comp Air Jet is an American eight-seat, low-wing, pressurized, tricycle undercarriage, turbofan-powered civil utility aircraft marketed by Comp Air for amateur construction.

The company website does not list it as being in production in 2022.

Design and development
In 2002 the co-owners of Aerocomp, which is now known as Comp Air, Steve Young and Ron Lueck announced the Comp Air Jet project. The jet is constructed from a "proprietary carbon-fiber hybrid sandwich" and powered by a Ukrainian Ivchenko AI-25 engine. Alternative engines planned for included the Pratt & Whitney JT12-8 or CJ610 or projected future Williams International or Agilis engines.

On July 10, 2004 the Comp Air Jet flew for the first time from Merritt Island Airport. Though the gear was not retracted during the flight, the aircraft still reached speeds of . The jet landed after 37 minutes with the landing taking about 2000 feet.

On January 11, 2005 Aerocomp flew the prototype back to the Merritt Island Airport for further development work after more than 30 hours of flight testing at Space Coast Regional Airport, Titusville, Florida.

Operational history
As of April 2011 the prototype remained the sole example registered with the Federal Aviation Administration.

Specifications (Comp Air Jet)

See also

References

External links
Official website archives on Archive.org

Jet
Homebuilt aircraft
2000s United States civil utility aircraft
Very light jets
Single-engined jet aircraft
Low-wing aircraft
Aircraft first flown in 2004
Logical shift. In computer science, a logical shift is a bitwise operation that shifts all the bits of its operand. The two base variants are the logical left shift and the logical right shift. This is further modulated by the number of bit positions a given value shall be shifted, such as shift left by 1 or shift right by n. Unlike an arithmetic shift, a logical shift does not preserve a number's sign bit or distinguish a number's exponent from its significand (mantissa); every bit in the operand is simply moved a given number of bit positions, and the vacant bit-positions are filled, usually with zeros, and possibly ones (contrast with a circular shift).

A logical shift is often used when its operand is being treated as a sequence of bits instead of as a number.

Logical shifts can be useful as efficient ways to perform multiplication or division of unsigned integers by powers of two. Shifting left by n bits on a signed or unsigned binary number has the effect of multiplying it by 2n. Shifting right by n bits on an unsigned binary number has the effect of dividing it by 2n (rounding towards 0).

Logical right shift differs from arithmetic right shift. Thus, many languages have different operators for them. For example, in Java and JavaScript, the logical right shift operator is , but the arithmetic right shift operator is . (Java has only one left shift operator (), because left shift via logic and arithmetic have the same effect.)

The programming languages C, C++, and Go, however, have only one right shift operator, . Most C and C++ implementations, and Go, choose which right shift to perform depending on the type of integer being shifted: signed integers are shifted using the arithmetic shift, and unsigned integers are shifted using the logical shift. In particular, C++ uses its logical shift operators as part of the syntax of its input and output functions, called "cin" and "cout" respectively.

All currently relevant C standards (ISO/IEC 9899:1999 to 2011) leave a definition gap for cases where the number of shifts is equal to or bigger than the number of bits in the operands in a way that the result is undefined. This helps allow C compilers to emit efficient code for various platforms by allowing direct use of the native shift instructions which have differing behavior. For example, shift-left-word in PowerPC chooses the more-intuitive behavior where shifting by the bit width or above gives zero, whereas SHL in x86 chooses to mask the shift amount to the lower bits to reduce the maximum execution time of the instructions, and as such a shift by the bit width doesn't change the value.

Some languages, such as the .NET Framework and LLVM, also leave shifting by the bit width and above unspecified (.NET) or undefined (LLVM).  Others choose to specify the behavior of their most common target platforms, such as C# which specifies the x86 behavior.

Example
If the bit sequence 0001 0111 (decimal 23) is logically shifted by one bit position, then:

Note: MSB = Most Significant Bit, 
LSB = Least Significant Bit

References

Binary arithmetic
Operators (programming)

zh:位操作#逻辑移位
Pummerer rearrangement. The Pummerer rearrangement is an organic reaction whereby an alkyl sulfoxide rearranges to an α-acyloxy–thioether (monothioacetal-ester) in the presence of acetic anhydride.

The stoichiometry of the reaction is:
RS(O)CHR'2  +  Ac2O   →   RSC(OAc)R'2  +  AcOH

Synthetic implementation
Aside from acetic anhydride, trifluoroacetic anhydride and trifluoromethanesulfonic anhydride have been employed as activators. Common nucleophiles besides acetates are arenes, alkenes, amides, and phenols.

The usage of α-acyl sulfoxides and Lewis acids, such as TiCl4 and SnCl4, allow the reaction to proceed at lower temperatures (0 °C).

Thionyl chloride can be used in place of acetic anhydride to trigger the elimination for forming the electrophilic intermediate and supplying chloride as the nucleophile to give an α-chloro-thioether:

Other anhydrides and acyl halides can give similar products. Inorganic acids can also give this reaction. This product can be converted to aldehyde or ketone by hydrolysis.

Mechanism
The mechanism of the Pummerer rearrangement begins with the acylation of the sulfoxide (resonance structures 1 and 2) by acetic anhydride to give 3, with acetate as byproduct.  The acetate then acts as a catalyst to induce an elimination reaction to produce the cationic-thial structure 4, with acetic acid as byproduct. Finally, acetate attacks the thial to give the final product 5.

The activated thial electrophile can be trapped by various intramolecular and intermolecular nucleophiles to form carbon–carbon bonds and carbon–heteroatom bonds.

The intermediate is so electrophilic that even neutral nucleophiles can be used, including aromatic rings with electron donating groups such as 1,3-benzodioxole:

It is possible to perform the rearrangement using selenium in the place of sulfur.

Pummerer fragmentation 
When a substituent on the α position can form a stable carbocation, this group rather than the α-hydrogen atom will eliminate in the intermediate step. This variation is called a Pummerer fragmentation.  This reaction type is demonstrated below with a set of sulfoxides and trifluoroacetic anhydride (TFAA):

The organic group "R2" shown in the diagram above on the bottom right is the methyl violet carbocation, whose pKR+ of 9.4 is not sufficient to out-compete loss of H+ and therefore a classical Pummerer rearrangement occurs. The reaction on the left is a fragmentation because the leaving group with pKR+ = 23.7 is particularly stable.

History
The reaction was discovered by , who reported it in 1909.

See also
 Organosulfur chemistry
 Polonovski reaction ― similar reaction involving an amine oxide
 Boekelheide reaction ― similar reaction involving a pyridine oxide

References

Rearrangement reactions
Name reactions
Dutch metal. Dutch metal is a form of brass. The alloy typically consists of 85–88% copper and the remainder being zinc. It is also known by other names such as "composition gold leaf",  "Dutch gold", "Schlagmetal" and "Schlag leaf".

It is very malleable and ductile and so can be beaten into very thin sheets. These sheets are sold for use as metal leaf or imitation gold leaf. The addition of arsenic produces an alloy with similar properties but coloured white.

See also
 , on the origins of English phrases using "Dutch" with negative connotations
Metal leaf
Gold leaf

References

Copper alloys
Cleon Lacefield. T. Cleon Lacefield is Lockheed Martin vice president and Orion program manager.

With his Lockheed Martin team in Denver and Houston, he won the CEV / Orion development contract from NASA in September 2006.

Career
He was NASA Space Shuttle flight director in the 1980s and Lockheed Martin Skunk Works X-33 program manager in the 1990s.

References 

Living people
Year of birth missing (living people)
Toleware. The term tôle, derived from the French tôle peinte, "painted sheet metal", is synonymous in English usage with japanning on tin, such as the tôle shades for bouillotte lamps and other candle shades, and trays and lidded canisters, in which stenciling and gilding often features, almost always on a black ground. Pontypool and Usk in South Wales made a reputation for tôle imitating Japanese lacquer starting in the early 19th century.

In American collectibles and antiques, toleware refers to kitchen-related objects created from metal, typically tin or thin steel, and are often in decorative styles such as Arts and Crafts and Pennsylvania Dutch.  Decorative painting on these items is common but not necessary.  This style of decorative art spread from Europe to the United States in the 18th century, and was popular in US kitchens in the 18th and 19th centuries.

In the field of handicrafts, tole painting on metal objects is a popular amateur pastime.

Toleware was featured on a United States Postal Service 1979 15-cent stamp, and in 2002 as part of the American Design Make-up stamp series with a value of 5 cents.

References

Kitchenware
Antiques
Daimler-Benz DB 600. The Daimler-Benz DB 600 was a German aircraft engine designed and  built before World War II as part of a new generation of German engine technology. It was a liquid-cooled inverted V12 engine, and powered the Messerschmitt Bf 110 and Heinkel He 111 among others.

Development
Most newer DB engine designs used in WW2 were based on this engine. The RLM made a set of specifications listing the technologies which the new class of German aero-engines required. Among these items was fuel injection systems rather than carburettors. Knowing that this would take some years to implement, the RLM permitted that the manufacturers could first design and produce the basic engine, and later develop it to include the injection system. The DB 600 formed this function (having in turn been developed from the Daimler-Benz F4A and F4B V12s), therefore when the injection system was ready it meant that the DB 600 was replaced by the otherwise similar DB 601, which in addition to direct fuel injection, also added the variable speed supercharger. Later DB series engines grew in bore, stroke, and horsepower, including the DB 603 and DB 605, but were generally similar to the pattern created with the DB 600.

Variants

DB 600 A/B 1,000 PS (986 hp, 735 kW) at 2,400 rpm at sea level with 5-minute Kurzleistung (short term output)
DB 600Aa
DB 600 C/D 850 PS (838 hp, 625 kW) at 2,250 rpm at sea level with 1-minute Erhöhte Kurzleistung
 910 PS (898 hp, 669 kW) at 2,400 rpm at  with 5-minute Kurzleistung
DB 600 Ga/Ha 1,050 PS (1,036 hp, 772 kW) at 2,400 rpm at sea level with 1-minute Erhöhte Kurzleistung
 1,050 PS (1,036 hp, 772 kW) at 2,400 rpm at  with 5-minute Kurzleistung

Note:
DB 600 A/C/Ga with a reduction gearing of 1.55
DB 600 B/D/Ha with a reduction gearing of 1.88

Source:
 Luftfahrt-Lehrbücherei, Band 21, Die Deutschen Flugmotoren: DB 600, Berlin, 1940

Applications

 Arado Ar 197 V1. 1937 prototype - naval variant of Arado Ar 68.
 Dornier Do 17 S-0 Three pre-production aircraft.
 Focke-Wulf Fw 57
 Focke-Wulf Fw 187 V6.
 Heinkel He 60C One test aircraft.
 Heinkel He 111 V5: DB 600A, B-1, B-2: DB 600C, G-4: DB 600G,  G-5: DB 600C, J-1: DB 600C
 Heinkel He 112 V7, V8.
 Heinkel He 114 Three He 114 B-2 exported to Romania.
 Junkers Ju 90 V1.
 Henschel Hs 128 V1. Twin engine, pressurised cockpit, high-altitude research aircraft.
 Messerschmitt Bf 109 V10 through V14. Prototypes.
 Messerschmitt Bf 110 V1, V2, V3. Prototypes.
 Messerschmitt Bf 162 V1, V2.

Specifications (DB 600C/D)

See also

References

Bibliography

 Green, William. The Augsburg Eagle: A Documentary History - Messerschmitt Bf 109. London: Macdonald and Jane's Publishing Group. 1980. 
 Smith, J R and Kay, Anthony L. German Aircraft of the Second World War. London: Putman & Company. 1972 
 Neil Gregor Daimler-Benz in the Third Reich. Yale University Press, 1998

External links

 Aviation History.com, DB 600 series page

Daimler-Benz aircraft engines
1930s aircraft piston engines
Inverted V12 aircraft engines
Heat capacities of the elements (data page). 

Specific heat capacity

Notes 
 All values refer to 25 °C and to the thermodynamically stable standard state at that temperature unless noted.
 Values from CRC refer to "100 kPa (1 bar or 0.987 standard atmospheres)". Lange indirectly defines the values to be standard atmosphere of "1 atm (101325 Pa)", although citing the same NBS and JANAF sources among others. It is assumed this inexactly refers to "ambient pressure".

References

CRC
As quoted in an online version of:
 David R. Lide (ed), CRC Handbook of Chemistry and Physics, 84th Edition. CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Heat Capacity of the Elements at 25 °C

WEL
As quoted at http://www.webelements.com/ from these sources:
 R.H. Schumm, D.D. Wagman, S. Bailey, W.H. Evans, and V.B. Parker in National Bureau of Standards (USA) Technical Notes 270–1 to 270–8, 1973.
 J.D. Cox, DD., Wagman, and V.A. Medvedev, CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, USA, 1989.

LNG
As quoted from various sources in:
 J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), McGraw-Hill, 1999; Section 6, Thermodynamic Properties; Table 6.3, Enthalpies and Gibbs Energies of Formation, Entropies, and Heat Capacities of the Elements and Inorganic Compounds

See also 

Thermodynamic properties
Chemical element data pages
Gary Drescher. Gary L. Drescher is a scientist in the field of artificial intelligence (AI), and author of multiple books on AI, including Made-Up Minds: A Constructivist Approach to Artificial Intelligence.

His book describes a theory of how a computer program might be implemented to learn and use new concepts that have not been programmed into it. It introduces the Schema Mechanism, a general learning and concept-building mechanism inspired by Jean Piaget's account of human cognitive development.

The Schema Mechanism is intended to replicate key aspects of cognitive development during infancy. It takes Piaget's theory of human development as a source of inspiration for an artificial learning mechanism, and it extends and tests Piaget's theory by seeing whether a specific mechanism that works according to Piagetian themes exhibits Piagetian abilities.

In 2001 and 2002, Drescher was a visiting fellow at the Center for Cognitive Studies at Tufts University, which is directed by the American philosopher Daniel Dennett. Following his work at Tufts, he wrote the 2006 book Good and Real: Demystifying Paradoxes from Physics to Ethics, in which he defends rigorously mechanistic materialism. In this book, he discusses quantum mechanics, defending the Everett or Multiple Worlds Interpretation, against the dominant Copenhagen Interpretation. Among other things, he argues that the Everett Interpretation of quantum mechanics, allows for a completely determinist outlook, and it undermines the views of those (like Roger Penrose) who hold that quantum mechanics can give us some special insights into the nature of consciousness. In this book, Drescher also provides treatments of the Prisoner's Dilemma and Newcomb's Problem to build a defense of the golden rule and Kant's categorical imperative which does not require that we posit anything beyond the physical world as understood by the natural sciences.

References

External links
Made-up Minds: A Constructivist Approach to Artificial Intelligence at MIT Press
Good and Real: Demystifying Paradoxes from Physics to Ethics at MIT Press
Tom Clark's Review of Gary Drescher's Good and Real: Demystifying Paradoxes from Physics to Ethics
 "Demystifying Quantum Mechanics: A Simple Universe with Quantum Uncertainty"

Drescher, Gary
Drescher, Gary
Drescher, Gary
Drescher, Gary
Drescher, Gary
Drescher, Gary
SARA (computer). SARA (SAABs räkneautomat, SAAB's calculating machine) was developed by SAAB when the capacity of BESK was insufficient for their needs. The project was started the fall of 1955 and became operational in 1956. SARA was built using the drawings of BESK that SAAB had bought for a symbolic sum and with the help of people who had worked with BESK, but didn't stay when Matematikmaskinnämnden decided that there would be no second generation. SARA wasn't used much, but it became the start of DataSAAB and the development of CK37 and D2.

References

IAS architecture computers
Science and technology in Sweden
Andradite. Andradite is a mineral species of the garnet group. It is a nesosilicate, with formula Ca3Fe2Si3O12.

Andradite includes three varieties:
 Colophonite: a historical variety found in the Scandinavian islands, brownish or reddish in color, often opaque or translucent.
 Demantoid: Vivid green in color, one of the most valuable and rare stones in the gemological world.
 Melanite: Black in color due to limited substitution of titanium for iron. Also known as "titanian andradite". Forms a solid solution with morimotoite and schorlomite depending on titanium and iron content.
 Topazolite: Yellow-green in color and sometimes of high enough quality to be cut into a faceted gemstone, it is rarer than demantoid.

It was first described in 1868 for an occurrence in Drammen, Buskerud, Norway. Andradite was named after the Brazilian statesman, naturalist, professor and poet José Bonifácio de Andrada e Silva (1763–1838).

Occurrence
It occurs in skarns developed in contact metamorphosed impure limestones or calcic igneous rocks; in chlorite schists and serpentinites and in alkalic igneous rocks (typically titaniferous). Associated minerals include vesuvianite, chlorite, epidote, spinel, calcite, dolomite and magnetite. It is found in Iran, Italy, the Ural Mountains of Russia, Arizona and California and in Dnipropetrovsk Oblast in Ukraine.

Like the other garnets, andradite crystallizes in the cubic space group Iad, with unit-cell parameter of 12.051 Å at 100 K.

The spin structure of andradite contains two mutually canted equivalent antiferromagnetic sublattices below the Néel temperature (TN=11 K).

See also

 Almandine
 Geology
 Grossular
 Mineral
 Mineral collecting
 Pyrope
 Spessartine
 Tsavorite
 Uvarovite

References

External links

Calcium minerals
Iron(III) minerals
Garnet gemstones
Minerals in space group 230
Titanium minerals
Minerals described in 1868