omniomni/omni-engineering huggingface dataset:
German submarine U-420. German submarine U-420 was a Type VIIC U-boat built for the Kriegsmarine for service during World War II. She was laid down in the Danziger Werft as yard number 121, launched on 18 August 1942 and commissioned on 16 December the same year under Oberleutnant zur See Peter Högqvist. She then joined the 8th U-boat Flotilla for training before transferring to the 11th flotilla for operations.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-420 had a displacement of  when at the surface and  while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of  for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of  for use while submerged. She had two shafts and two  propellers. The boat was capable of operating at depths of up to .

The submarine had a maximum surface speed of  and a maximum submerged speed of . When submerged, the boat could operate for  at ; when surfaced, she could travel  at . U-420 was fitted with five  torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one  SK C/35 naval gun, 220 rounds, and two twin  C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

Service history

First patrol
U-420s first patrol involved her leaving Kiel on 12 June 1943 and arriving at Lorient in occupied France on 16 June 1943, having hugged the Norwegian coast and sailed around the north of Scotland. She then crossed the Atlantic, but was attacked on 3 July by a Canadian B-24 Liberator. The boat was hit by a Fido homing torpedo which killed two men and wounded a third. The boat sustained enough damage to force the patrol to be cut short.

Second patrol and loss
Following a short transit voyage from Lorient to Brest, U-420 set off on her second patrol on 9 October 1943. After 20 October, she was never heard from again and her fate remains an unsolved mystery.

Previously recorded fate
A postwar assessment stated that U-420 was sunk on October 26, 1943 in the North Atlantic at position  by depth charges from a Canadian B-24 Liberator of RCAF Squadron 10/A. This attack was actually against , inflicting no damage.

References

Bibliography

External links

Missing U-boats of World War II
1942 ships
Ships built in Danzig
U-boats commissioned in 1942
U-boats sunk in 1943
German Type VIIC submarines
World War II submarines of Germany
U-boats sunk by unknown causes
Maritime incidents in October 1943
Carver High School (Houston, Texas). George Washington Carver High School for Applied Technology, Engineering and the Arts is a public secondary school in Houston, Texas, United States. The school is located in the historically African American community of Acres Homes and serves grades 9 through 12. It is named for African-American scientist and educator George Washington Carver. Carver is a magnet school and is a part of the Aldine Independent School District.

Programs offered
Carver Magnet High School provides students with core subject classes and specialized areas of interest in performing arts, engineering, and the arts. Carver doesn't offer extracurricular sports, so students are bused to their home high schools to play on athletic teams.

Magnet School of Applied Engineering
Architecture
Electronics Engineering
Interior Design
Manufacturing Engineering
Robotics - Mechatronics Engineering

Magnet School of Performing & Visual Arts
Visual Arts
Vocal Music
Dance
Instrumental Music
Theater

Academic performance
For the 2018-2019 school year, the school received a B grade from the Texas Education Agency, with an overall score of 84 out of 100. The school received a B grade in two domains, Student Achievement (score of 85) and School Progress (score of 87), and a C grade in Closing the Gaps (score of 76). The school  received two of the seven possible distinction designations for Academic Achievement in Science and Academic Achievement in English Language Arts/Reading.

Demographics
In the 2018-2019 school year, Carver High School had 776 students. 56.4% were African American, 0.3% were Asian, 40.2% were Hispanic, 0.3% were American Indian, 1.5% were White, and 1.3% were two or more races. 76.4% of students were Economically Disadvantaged, 6.4% were English Language Learners, and 6.3% received Special Education services.

Feeder pattern
Carver has no actual feeder patterns, since it is a magnet school. Eighth grade students from middle schools from all over the Aldine school district apply for admissions into Carver the Spring semester prior to their freshmen year and attend Carver upon acceptance for high school.

Students in the 8th grade who are presently enrolled at both Drew and Grantham Academy are automatically accepted into Carver unless they choose to leave the Aldine Magnet Program and attend their home high school.

Texas Historical Site
On Saturday, May 24, 2007, the Texas Historical Commission dedicated a historical marker at Carver High School.

Notable alumni
 Loretta Devine — Actress

References

External links
Carver High School
Carver High School at schooldigger
Carver High School at greatschools

Public high schools in Houston
Aldine Independent School District high schools
Magnet schools in Houston
Hubbing. Hubbing is a metalworking process that is used to make dies. It is a cold-working process, which means that it occurs well below the melting temperature of the metal being worked.

Process

In hubbing, a male hub (master) is created with a profile that will form an impression on the female piece. The male hub is generally hardened and the female die block softened by annealing to help form the impression. As the metal flows the face of the die block is deformed, and, generally, must be machined flat. The die block is often a cylinder that is reinforced with a surrounding steel ring during the hubbing process. Hubbing is usually less expensive than die sinking, i.e., machining the female die, and multiple dies can be made from the male hub.

In the case of mild steel, a typical hubbing press exerts a pressure of approximately 1500 short tons-force per square inch (21 GPa) to transfer the image from a master hub into the master die.

See also

Coining (metalworking)
Die making

References

DeGarmo, E. Paul, J T. Black, and Ronald A. Kohser. Materials and Processes in Manufacturing. Upper Saddle River, New Jersey: Prentice Hall, 1997. 

Metal forming
Charge control. Charge control is a technology that lets an electric utility control, in real time, the charging of a gridable (plug-in) vehicle, such as a plug-in hybrid (PHEV) or a battery electric vehicle (BEV). Through charge control, the utility is able to postpone charging of the vehicle during time of peak demand. Additionally, this technology may enable the owner and the power company to track the vehicle's usage and performance, while on the road and while charging.

Charge control advantages 
 During times of peak demand, the electric utility prefers to reduce the demand, rather than turning on additional (dirtier and more expensive) power plants. In places that subscribe to smart power grid services, the electric utility shuts off appliances such as air conditioners until the peak demand is over. Similarly, charge control allows the electric utility to postpone charging until the peak demand is over. Charge control is not as far reaching as V2G (a technology that allows the power company to buy energy back from a plug-in car) but is very effective because it is less expensive to implement than V2G.
 The hardware used in charge control also monitors the vehicle (when driving or when plugged-in). As a side benefit, that information is available, through the web, to both the electric utility and the owner, for the purpose of tracking and optimizing the performance of the vehicle.
 Eventually, the electric utility may offer better pricing to owners of charge control equipped vehicles.

Comparison to V2G 
In both V2G and charge control, the electric utility can control the power flow between a plug-in vehicle and the power grid. However, in charge control power only flows from the grid to the vehicle, while in V2G power can flow in both directions.

Peak load leveling 
Disabling charging in charge control vehicles helps balance the loading on the power grid by "valley filling" (charging at night when demand is low) and "peak shaving" (not charging when demand is high). It can enable utilities new ways to provide regulation services (keeping voltage and frequency stable).

See also 
 Vehicle-to-grid
 Distributed generation

References 
 AC Propulsion eBox specifications

Electric vehicle technologies
Green vehicles
Data Link Solutions. Data Link Solutions (DLS) is a joint venture entity that was created in 1996 between GEC-Marconi Hazeltine (now known as BAE Systems) and Rockwell Collins for the purpose of developing, manufacturing and supporting the Joint Tactical Information Distribution System (JTIDS).

DLS is headquartered in Cedar Rapids, Iowa, and also has facilities in Wayne, New Jersey.

Products
The company has the extensive contract experience in JTIDS Class 2 / 2H / 2M, the MIDS Fighter Data Link (FDL) and the MIDS Low Volume Terminal (LVT-1), with over $275 million in contracts to date and production deliveries started for MIDS LVT and FDL terminals.

In June 2006 Data Link Solutions (DLS) and Viasat entered into an agreement to cooperatively produce and sell Multifunctional Information Distribution System (MIDS) terminals for the Joint Tactical Radio System (JTRS). DLS is leading the development effort on MIDS JTRS under an $82 million product improvement program contract.

In August 2007 Data Link Solutions received a $28 million order for Multifunctional Information Distribution System-Low Volume Terminals (MIDS-LVT) from the Space and Naval Warfare Systems Command (SPAWAR) in San Diego. The terminals will be installed in the U.S. Navy F/A-18 and EA-6B, U.S. Air Force F-16, B-1, B-2 and B-52 as well as other battle elements.

On January 7, 2024, DLS was sanctioned by the Chinese government due to U.S. arms sales to Taiwan.

External links
Data Link Solutions LLC homepage

References

Military radio systems
Avionics companies
American entities subject to Chinese sanctions
Defense companies of the United States
Manufacturing companies based in Iowa
Electronics companies established in 1996
Telecommunications companies established in 1996
1996 establishments in Iowa
Joint ventures
PWS-21. The PWS-21 was a Polish passenger aircraft for 4 passengers, built in PWS factory in 1930, that remained a prototype.

Development
The aircraft was developed for a contest for a successor of Junkers F-13 in LOT Polish Airlines. The first design of 1929, named PWS-21, developed by Stanisław Cywiński and Jarosław Naleszkiewicz, was a braced high-wing plane, but it was not realized because LOT demanded bigger passenger cab.

The next design, named PWS-21bis, was a cantilever high-wing plane, similar to Fokker F.VIIa/1m design. The only prototype (markings SP-AEC) first flew in the spring, probably April 1930 in Biała Podlaska. Its counterpart was Lublin R-XI.

The plane appeared not successful. It was too heavy, what resulted in poor speed, ceiling and range, and long take off. In 1931 it was evaluated in LOT airlines, but after a test flight it was returned to the factory. However, at that time there was its development, PWS-24 built, sharing the same lightweight wing, which was ordered by LOT.

Description (PWS-21bis)

High-wing cantilever monoplane of mixed construction, with closed cab and single engine. A fuselage made of a steel frame, covered with canvas. Straight one-piece wooden wing, with elliptical endings, plywood covered, two-spar. Crew of two (pilot and mechanic), in a cabin before the wing, with twin controls. The cabin had a vertical front windshield and doors on both sides. Next and slightly below in a fuselage, under the wing, there was a cabin for 4 passengers, with a door on the left. The cabin had a toilet. The fifth passenger could be taken instead of the mechanic. 9 cylinder radial engine Skoda Wright Whirlwind J-5 (240 hp take-off power, 220 hp nominal power) in the fuselage front, fitted with a Townend ring. Two-blade metal propeller of a fixed pitch. Conventional landing gear, with a rear skid; struts with shock absorbers joined the main gear with wings. Fuel tanks 250 L in central wing section.

Specifications (PWS-21bis)

See also

References

Further reading
Andrzej Glass: "Polskie konstrukcje lotnicze 1893-1939" (Polish aviation constructions 1893-1939), WKiŁ, Warsaw 1977 (Polish language, no ISBN)

External links

Photos and drawings at Ugolok Neba site 

1930s Polish airliners
PWS aircraft
Single-engined tractor aircraft
High-wing aircraft
Aircraft first flown in 1930
Aircraft with fixed conventional landing gear
Bauer Automatic. The Bauer Automatic is an American-made copy of the Baby Browning.  Made of stainless steel, they are chambered in .25 ACP with a six-round capacity detachable box magazine. The Bauer was manufactured in Fraser, Michigan from 1972–1984. The pistol was marketed as the Fraser-25 from 1984 to 1986.

Features
The Bauer .25 Automatic was made of precision machined 416 stainless steel investment castings and fitted by hand.  The pistol features a two-position thumb safety. One position locks the slide while the other position locks the slide in the disassembly position, allowing the user to rotate the barrel clockwise 45 degrees and remove the entire slide (rather than counterclockwise-as is the case with the FN Baby Browning pistol, to avoid copyright infringement claims from FN).

Factory options included "white pearl" (plastic) or wood grips, and a variety of holsters. An engraved version was manufactured for the US Bicentennial in 1976.

Many parts interchange with the FN Baby Browning, including grips, magazines, and various internal parts.

References

External links
 Owner's Manual

.25 ACP semi-automatic pistols
Semi-automatic pistols of the United States
Newton's metal. Newton's metal is a fusible alloy with a low melting point. Its composition by weight is 8 parts bismuth, 5 parts lead and 3 parts tin; its melting point is 97 °C.

Newton's metal is comparable to Cerrobend, but avoids its toxic cadmium content. This has encouraged its use for medical applications for easily shaped shielding during radiotherapy.

References 

Fusible alloys
Potassium octachlorodimolybdate. Potassium octachlorodimolybdate (systematically named potassium bis(tetrachloromolybdate)(Mo–Mo)(4−)) is an inorganic compound with the chemical formula . It is known as a red-coloured, microcrystalline solid. The anion is of historic interest as one of the earliest illustrations of a quadruple bonding. The salt is usually obtained as the pink-coloured dihydrate.

The compound is prepared in two steps from molybdenum hexacarbonyl:

The reaction of the acetate with HCl was first described as providing trimolybdenum compounds, but subsequent crystallographic analysis confirmed that the salt contains the  anion, with D4h symmetry, in which the two Mo atoms are linked by a quadruple bond. Each Mo atom is bounded with four  ligands by a single bond. Each  group is a regular square pyramid, with an Mo atom at the apex, and four Cl atoms at the vertices of the square base of the pyramid. The Mo–Mo distance is 214 pm.

References

Potassium compounds
Molybdenum compounds
Chloro complexes
Chemical compounds containing metal–metal bonds
Nozaki–Hiyama–Kishi reaction. The Nozaki–Hiyama–Kishi reaction is a nickel/chromium coupling reaction forming an alcohol from the reaction of an aldehyde with an allyl or vinyl halide. In their original 1977 publication, Tamejiro Hiyama and Hitoshi Nozaki reported on a chromium(II) salt solution prepared by reduction of chromic chloride by lithium aluminium hydride to which was added benzaldehyde and allyl chloride:

Compared to Grignard reactions, this reaction is very selective towards aldehydes with large tolerance towards a range of functional groups such as ketones, esters, amides and nitriles. Enals give exclusively 1,2-addition. Solvents of choice are DMF and DMSO, one solvent requirement is solubility of the chromium salts. Nozaki–Hiyama–Kishi reaction is a useful method for preparing medium-size rings.

In 1983 the scope was extended by the same authors to include vinyl halides or triflates and aryl halides. It was observed that the success of the reaction depended on the source of chromium(II) chloride and in 1986 it was found that this is due to nickel impurities. Since then nickel(II) chloride is used as a co-catalyst.

In the same year Yoshito Kishi et al. independently discovered the beneficial effects of nickel in his quest for palytoxin:

Palladium acetate was also found to be an effective cocatalyst.

Reaction mechanism
Nickel is the actual catalyst when small amounts of a nickel salt are added to the reaction. Nickel(II) chloride is first reduced to nickel(0) with 2 equivalents of chromium(II) chloride (as sacrificial catalyst) leaving chromium(III) chloride. The next step is oxidative addition of nickel into the carbon to halide bond forming an alkenylnickel R–Ni(II)–X intermediate followed by a transmetallation step exchanging NiX with a Cr(III) group to an alkenylchromium R–Cr(III)–X intermediate and regenerating Ni(II). This species reacts with the carbonyl group in a nucleophilic addition.

The amount of nickel used should be low as a direct alkene coupling to a diene is a side reaction.

Related reactions are the Grignard reaction (magnesium), the Barbier reaction (zinc) and addition reactions involving organolithium reagents.

References

Carbon-carbon bond forming reactions
Name reactions
Heavy melting steel. Heavy melting steel (HMS) or heavy melting scrap is a designation for recyclable steel and wrought iron. It is broken up into two major categories: HMS 1 and HMS 2, where HMS 1 does not contain galvanized and blackened steel, whereas HMS 2 does. The Institute of Scrap Recycling Industries breaks up the categories further:
 ISRI 200 (HMS 1): Wrought iron or steel scrap  and larger in thickness. All pieces must be smaller than 
 ISRI 201 (HMS 1): Same as ISRI 200 except pieces must be smaller than .
 ISRI 202 (HMS 1): Same as ISRI 200 except pieces must be smaller than .
 ISRI 203 (HMS 2): Wrought iron or steel scrap, black and galvanized,  and larger in thickness.
 ISRI 204 (HMS 2): Same as ISRI 203 except pieces must be smaller than .
 ISRI 205 (HMS 2): Same as ISRI 204 except it may contain automotive scrap except for thin gauge material.
 ISRI 206 (HMS 2): Same as ISRI 205 except pieces must be smaller than .

HMS 1 and 2 are widely traded, particularly in the western hemisphere.

Both HMS 1 and 2 comprise obsolete scrap only - iron and steel recovered from items demolished or dismantled at the end of their life.

HMS 1 is the term for heavier scrap which has a density of at least 0.7 tons per cubic meter, whereas HMS 2 would be lighter steel scrap

Because both grades guarantee a minimum piece thickness – at least  for HMS 1, and  for HMS 2 – consignments have a high density. Both also have defined maximum dimensions (usually ), and should be prepared to facilitate handling and charging to a furnace.

This density, sizing and preparation makes for efficient furnace operation by minimising the time to charge enough scrap for a full melt. In contrast, thin mixed scrap greatly increases charging time, cutting furnace productivity.

Variations on maximum piece size are covered by ISRI (North America’s Institute of Scrap Recycling Industries) codes. HMS is usually traded as a blend of 1 and 2, either a premium blend (80:20) or lower grade mixes (70:30) and (60:40). Other major heavy scrap grades include Japan’s H2 and A3 from the CIS.

References

Steels
Gatard Statoplan Poussin. The Gatard Statoplan AG 02 Poussin (French: "Chick") was a light, single-seat sports airplane developed in France in the late 1950s and marketed for homebuilding. In layout, it was a low-wing cantilever monoplane of short-coupled design with fixed tailwheel undercarriage. Construction was a plywood-covered wooden structure throughout, and the cockpit was enclosed by a large perspex bubble canopy. The variable-incidence horizontal stabiliser was fitted with small endplates to provide extra directional stability but there were no separate elevators.

An unusual feature of the design was the aircraft's method of climbing. In most aircraft designs, climb is achieved (without change in engine power) by pitching the aircraft so that the angle of attack of the wings increases, thereby increasing lift. The Poussin, however, was designed to climb by lowering specially-designed flaps and trimming the tailplane to balance out any change in pitch, therefore allowing the aircraft to achieve its maximum rate of climb while keeping the fuselage within 4° of level. The extra drag created by the lowered flaps was balanced by drag saved by keeping the fuselage level.

Specifications (Second prototype)

References

 
 
 
 

1950s French sport aircraft
Homebuilt aircraft
Gatard aircraft
Single-engined tractor aircraft
Low-wing aircraft
Aircraft first flown in 1957
Fokker F.XIV. The Fokker F.XIV was a cargo plane built in the Netherlands in the late 1920s by Fokker. It was a high-wing cantilever monoplane of conventional trimotor layout. The sole example was tested by KLM but never put into service.

Development and design

In early 1929, Fokker designed and built a prototype of a single-engine cargo aircraft, probably to meet a requirement from KLM. The F.XIV was a high-wing monoplane powered by a  Gnome-Rhône Jupiter VI radial engine and had a fixed tailwheel undercarriage. Two pilots sat in an enclosed cockpit forward of the wing's leading edge, while the aircraft's cabin could carry  in a  long cabin.  

There was little interest from airlines in a cargo aircraft, and in 1931 Fokker rebuilt the F.XIV as a three-engined passenger airliner, the F.XIV-3m. The Jupiter was replaced by three  Lorraine Algol radial engines, while the cabin had seats for eight passengers. Although tested by KLM, it was not purchased or operated by them, and ended its days as an exhibit in a pleasure garden.

Specifications (F.XIV-3m)

See also

References

1920s Dutch cargo aircraft
F.XIV
Aircraft first flown in 1929