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Topic Review
Hydrogen-Based Hybrid Microgrid System
Hydrogen is acknowledged as a potential and appealing energy carrier for decarbonizing the sectors that contribute to global warming, such as power generation, industries, and transportation. Many people are interested in employing low-carbon sources of energy to produce hydrogen by using water electrolysis. Additionally, the intermittency of renewable energy supplies, such as wind and solar, makes electricity generation less predictable, potentially leading to power network incompatibilities. Hence, hydrogen generation and storage can offer a solution by enhancing system flexibility. Hydrogen saved as compressed gas could be turned back into energy or utilized as a feedstock for manufacturing, building heating, and automobile fuel.
  • 1.1K
  • 10 Nov 2022
Topic Review
Arms Export Control Act
The Arms Export Control Act of 1976 (Title II of Pub.L. 94–329, 90 Stat. 729, enacted June 30, 1976, codified at 22 U.S.C. ch. 39) gives the President of the United States the authority to control the import and export of defense articles and defense services. The H.R. 13680 legislation was passed by the 94th Congressional session and enacted into law by the 38th President of the United States Gerald R. Ford on June 30, 1976. The Act of Congress requires international governments receiving weapons from the United States to use the armaments for legitimate self-defense. Consideration is given as to whether the exports "would contribute to an arms race, aid in the development of weapons of mass destruction, support international terrorism, increase the possibility of outbreak or escalation of conflict, or prejudice the development of bilateral or multilateral arms control or nonproliferation agreements or other arrangements." The Act also places certain restrictions on American arms traders and manufacturers, prohibiting them from the sale of certain sensitive technologies to certain parties and requiring thorough documentation of such trades to trusted parties. When the President is aware of the possibility of violations of the AECA, the law requires a report to Congress on the potential violations. U.S. Immigration and Customs Enforcement (ICE) conducts an industry outreach program called the Project Shield America to prevent foreign adversaries, terrorists, and criminal networks from obtaining U.S. munitions and strategic technology.
  • 706
  • 09 Nov 2022
Topic Review
Miztec (Schooner Barge)
The Miztec was built as a 3-masted schooner in 1890. She was later converted to a schooner barge and served as a consort for lumber hookers on the Great Lakes. She escaped destruction in a severe 1919 storm that sank her longtime companion, the SS Myron, only to sink on the traditional day of bad luck, Friday the 13th, 1921, with the loss of all hands. She came to rest on Lake Superior's bottom off Whitefish Point near the Myron. The Miztec’s wreck was illegally salvaged in the 1980s. Artifacts from the Miztec became the property of the State of Michigan after they were seized in a 1992 Michigan Department of Natural Resources and Environment (DNRE) raid on the Great Lakes Shipwreck Museum. The State allows the museum to hold a triple sheave block and hook and a double sheave block and hook from the Miztec as a loan. Her wreck is now protected by the Whitefish Point Underwater Preserve as part of an underwater museum.
  • 405
  • 09 Nov 2022
Topic Review
Cinéma Pur
Cinéma Pur (French for "Pure Cinema") was an avant-garde film movement begun by filmmakers, like René Clair, who "wanted to return the medium to its elemental origins" of "vision and movement."
  • 2.6K
  • 09 Nov 2022
Topic Review
List of Human Spaceflight Programs
This is a list of human spaceflight programs, including successful programs, programs that were canceled, and programs planned for the future. The criteria for what constitutes human spaceflight vary. The FAI defines spaceflight as any flight over 100 kilometers (62 mi). In the U.S. professional, military, and commercial astronauts who travel above an altitude of 80 kilometers (50 mi) are awarded astronaut wings. This article follows the FAI definition of spaceflight. Until the 21st century, human spaceflight programs were sponsored exclusively by governments, through either the military or civilian space agencies. With the launch of the privately funded SpaceShipOne in 2004, a new category of human spaceflight programs – commercial human spaceflight – arrived.
  • 2.1K
  • 09 Nov 2022
Topic Review
Astronomical Interferometer
An astronomical interferometer is an array of separate telescopes, mirror segments, or radio telescope antennas that work together as a single telescope to provide higher resolution images of astronomical objects such as stars, nebulas and galaxies by means of interferometry. The advantage of this technique is that it can theoretically produce images with the angular resolution of a huge telescope with an aperture equal to the separation between the component telescopes. The main drawback is that it does not collect as much light as the complete instrument's mirror. Thus it is mainly useful for fine resolution of more luminous astronomical objects, such as close binary stars. Another drawback is that the maximum angular size of a detectable emission source is limited by the minimum gap between detectors in the collector array. Interferometry is most widely used in radio astronomy, in which signals from separate radio telescopes are combined. A mathematical signal processing technique called aperture synthesis is used to combine the separate signals to create high-resolution images. In Very Long Baseline Interferometry (VLBI) radio telescopes separated by thousands of kilometers are combined to form a radio interferometer with a resolution which would be given by a hypothetical single dish with an aperture thousands of kilometers in diameter. At the shorter wavelengths used in infrared astronomy and optical astronomy it is more difficult to combine the light from separate telescopes, because the light must be kept coherent within a fraction of a wavelength over long optical paths, requiring very precise optics. Practical infrared and optical astronomical interferometers have only recently been developed, and are at the cutting edge of astronomical research. At optical wavelengths, aperture synthesis allows the atmospheric seeing resolution limit to be overcome, allowing the angular resolution to reach the diffraction limit of the optics. Astronomical interferometers can produce higher resolution astronomical images than any other type of telescope. At radio wavelengths, image resolutions of a few micro-arcseconds have been obtained, and image resolutions of a fractional milliarcsecond have been achieved at visible and infrared wavelengths. One simple layout of an astronomical interferometer is a parabolic arrangement of mirror pieces, giving a partially complete reflecting telescope but with a "sparse" or "dilute" aperture. In fact the parabolic arrangement of the mirrors is not important, as long as the optical path lengths from the astronomical object to the beam combiner (focus) are the same as would be given by the complete mirror case. Instead, most existing arrays use a planar geometry, and Labeyrie's hypertelescope will use a spherical geometry.
  • 780
  • 09 Nov 2022
Topic Review
Compaq Presario 2200
The Compaq Presario 2200 is a small form factor desktop PC produced by Compaq from 1997 to 1998. It was produced as a slim, small form factor machine mainly intended for budget-minded consumers. When launched, it had 16 MB of EDO DRAM that was expandable up to 80 MB and a Cyrix MediaGXi microprocessor, clocking at 180 MHz. It did not include an Ethernet port; however, the modem can be swapped out for a compatible 8-bit ISA Ethernet card to allow the computer to be connected to the Internet or a LAN network. There are no USB ports on the computer, even though the small metal flap might suggest that Compaq considered installing USB ports during the time the computer was developed. This computer model is not to be confused with the newer Compaq Presario 2200 laptop computer.
  • 2.5K
  • 09 Nov 2022
Topic Review
La Noumbi
La Noumbi is a floating production storage and offloading (FPSO) unit operated by Perenco. The vessel, converted from the former Finnish Aframax crude oil tanker Tempera by Keppel Corporation, will replace an older FPSO unit in the Yombo field off the Republic of Congo in 2018. Built at Sumitomo Heavy Industries in Japan in 2002, Tempera was the first ship to utilize the double acting tanker (DAT) concept in which the vessel is designed to travel ahead in open water and astern in severe ice conditions. Tempera and her sister ship Mastera, built in 2003, were used mainly to transport crude oil, year-round, from the Russia n oil terminal in Primorsk to Neste Oil refineries in Porvoo and Naantali. In 2015, Neste sold Tempera to the oil and gas company Perenco for conversion to an FPSO.
  • 274
  • 09 Nov 2022
Topic Review
Pepper-Box
The pepper-box revolver or simply pepperbox (also "pepper-pot", from its resemblance to the household pepper shakers) is a multiple-barrel firearm, mostly in the form of a handgun, that has three or more gun barrels in a coaxially revolving mechanism. Each barrel holds a single shot, and the shooter can manually rotate the whole barrel assembly to sequentially index each barrel into alignment with the lock/hammer, similar to operating a revolver cylinder. Pepperbox guns have existed for all action and ammunition systems: matchlock, wheellock, flintlock, snaplock, caplock, pinfire, rimfire and centerfire. While they are usually sidearms, a few long guns were also made. For example, Samuel Colt owned a three-barrel pepperbox matchlock musket from British India, and an eight-barrel pepperbox shotgun was designed in 1967 but never went into production.
  • 847
  • 09 Nov 2022
Topic Review
Variobahn
The Variobahn, formerly known as the Variotram, is a German-designed model of articulated low-floor tram and light rail vehicle. Since its introduction in 1993, the Variobahn has been manufactured variously by ABB, Adtranz, Bombardier Transportation, and since 2001 by Stadler Rail. As of 2009, 254 trams have been ordered, with an additional 110 on option. A unit costs about €2.5 million. Operators include the Graz Holding, the Bergen Light Rail, the Chemnitz Tramway, Verkehrsverbund Rhein-Ruhr, the Helsinki Tramway, the Rhine Neckar Area Tramway and London Tramlink.
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  • 09 Nov 2022
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