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Biography
Herman Bank
Herman Bank (October 26, 1916 - November 2, 2012[1]) was an American mechanical engineer who worked for the Jet Propulsion Laboratory (JPL) from 1947 to 1984. He was one of the “Rocket Boys,” who were first-generation scientists and engineers of the Space Age.[2] While working at JPL, Bank worked as a mechanical engineer on the Bumper Project, supervised the structural design for Explorer 1,
  • 440
  • 09 Dec 2022
Topic Review
Herring–Nabarro Creep
Nabarro–Herring creep is a mode of deformation of crystalline materials (and amorphous materials) that occurs at low stresses and held at elevated temperatures in fine-grained materials. In Nabarro–Herring creep (NH creep), atoms diffuse through the crystals, and the creep rate varies inversely with the square of the grain size so fine-grained materials creep faster than coarser-grained ones. NH creep is solely controlled by diffusional mass transport. This type of creep results from the diffusion of vacancies from regions of high chemical potential at grain boundaries subjected to normal tensile stresses to regions of lower chemical potential where the average tensile stresses across the grain boundaries are zero. Self-diffusion within the grains of a polycrystalline solid can cause the solid to yield to an applied shearing stress, the yielding being caused by a diffusional flow of matter within each crystal grain away from boundaries where there is a normal pressure and toward those where there is a normal tension. Atoms migrating in the opposite direction account for the creep strain ([math]\displaystyle{ \epsilon_{NH} }[/math]). The creep strain rate is derived in the next section. NH creep is more important in ceramics than metals as dislocation motion is more difficult to effect in ceramics.
  • 1.4K
  • 08 Nov 2022
Topic Review
Heterogeneous Catalysts for Carbon Dioxide Methanation
CO2 methanation offers a promising route for converting CO2 into valuable chemicals and energy fuels at the same time as hydrogen is stored in methane, so the development of suitable catalysts is crucial. Among the noble metal-based catalysts (Ru, Rh, and Pd), Ru-based catalysts show the best catalytic performance. In the non-noble metal catalysts, Ni-based catalysts are the best among Ni-, Co-, and Fe-based catalysts. The factors predominantly affecting catalytic performance are the dispersion of the active metal; the synergy of the active metal with support; and the addition of dopants. 
  • 244
  • 19 Jan 2024
Topic Review
Heterogeneous Catalysts Used in Hydrothermal Gasification
Supercritical water gasification has emerged as a promising technology to sustainably convert waste residues into clean gaseous fuels rich in combustible gases such as hydrogen and methane. The composition and yield of gases from hydrothermal gasification depend on process conditions such as temperature, pressure, reaction time, feedstock concentration, and reactor geometry. However, catalysts also play a vital role in enhancing the gasification reactions and selectively altering the composition of gas products. Catalysts can also enhance hydrothermal reforming and cracking of biomass to achieve desired gas yields at moderate temperatures, thereby reducing the energy input of the hydrothermal gasification process. 
  • 679
  • 04 Jul 2023
Topic Review
Heterogeneous Networks
Communication technologies have drastically increased the number of wireless networks. Heterogeneous networks have now become an indispensable fact while designing the new networks and the way the data packet moves from device to device opens new challenges for transmitting the packet speedily, with maximum throughput and by consuming only confined energy. 
  • 1.9K
  • 23 Sep 2022
Topic Review
Hexapod Robots
The static stability of hexapods motivates their design for tasks in which stable locomotion is required, such as navigation across complex environments. This task is of high interest due to the possibility of replacing human beings in exploration, surveillance and rescue missions. For this application, the control system must adapt the actuation of the limbs according to their surroundings to ensure that the hexapod does not tumble during locomotion.
  • 1.0K
  • 25 Aug 2021
Topic Review
Hexavalent Chromium Removal by Electrochemical Processes
Hexavalent chromium (Cr(VI)) is a toxic, mutagenic, teratogenic, and carcinogenic species. Its origin is in industrial activities. Therefore, its effective control is realized on a source basis. Although chemical methods proved effective in removing Cr(VI) from wastewaters, more economic solutions with a minimum sludge production have been sought. Among them, the use of electrochemical processes has emerged as a viable solution to the problem. Much research was conducted in this area.
  • 516
  • 15 Mar 2023
Topic Review
HH Ferry Route
The HH Ferry route (About the name: Helsingør–Helsingborg; Helsingør is Danish for Elsinore) is a very old shipping route which connects Helsingør on Zealand, Denmark and Helsingborg, Scania, Sweden across the northern, and narrowest part of the Øresund. Due to the short distance, which is less than 3 nautical miles, is it one of the world's busiest international car ferry routes, with around 70 daily departures from each harbour. The oldest-known written mention of the route dates to the German traveller Adam of Bremen in the 11th century, but it has likely been in use much longer. Before 1658, the route was a domestic Danish route. For several centuries, the route has been run regularly by various Danish shipping lines. Its significance grew during the 1950s, but since the inauguration of the Øresund Bridge in 2000, at the southern end of the Øresund, it has lost some significance but remains as one of the world's most important ferry routes, particularly as a cheaper alternative to the bridge tolls. Since 1952, passports have not been required for Scandinavian and Finnish citizens.
  • 461
  • 21 Nov 2022
Topic Review
Hierarchical Understanding in Robotic Manipulation
In the quest for intelligent robots, it is essential to enable them to understand tasks beyond mere manipulation. Achieving this requires a robust parsing mode that can be used to understand human cognition and semantics.
  • 287
  • 31 Jan 2024
Topic Review
High Dynamic Range (Display and Formats)
High Dynamic Range (HDR) is a video and image technology that improves the way light is represented. It overcomes the limits of the standard format that is named Standard Dynamic Range (SDR). HDR offers the possibility to represent substantially brighter highlights, darker shadows, more details in both sides and more colorful colors than what was previously possible. HDR do not increase display's capabilities, rather it allows to make better use of displays that have high brightness, contrast and colors capabilities. Not all HDR displays have the same capabilities and HDR contents will thus look different depending the display used. HDR emerged first for videos in 2014. HDR10, HDR10+, Dolby Vision and HLG are common HDR formats. Some still pictures formats do also support HDR.
  • 5.6K
  • 01 Nov 2022
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