Technology and the built world

H-class battleship proposals

The H-class battleship proposals, including the H-39 design, were plans for six large German Kriegsmarine battleships under Plan Z, halted after World War II began in 1939.

H-Coal process

The H-Coal process is a direct coal liquefaction process developed by Hydrocarbon Research, Inc., demonstrated at a 600 ton-per-day pilot plant in Catlettsburg, Kentucky, from 1980 to 1982.

H-I

The H-I (H-Iロケット) was a Japanese expendable launch vehicle developed by NASDA and flown nine times between 1986 and 1992, bridging the N series and the H-II.

The H-II was a two-stage Japanese expendable launch vehicle developed by NASDA as Japan's first fully domestic rocket, flying seven times from 1994 to 1999 with five successes before retirement in favor of the H-IIA.

H-II Transfer Vehicle

The H-II Transfer Vehicle (HTV), nicknamed Kounotori, was a Japanese uncrewed cargo spacecraft flown by JAXA to resupply the ISS nine times between 2009 and 2020.

H-IIA

The H-IIA, also written H2A, is a Japanese expendable liquid-fuel launch vehicle, Japan's mainstay rocket for satellites and probes, flown by JAXA from 2001 to 2025.

H-IIB

The H-IIB was a Japanese heavy-lift rocket developed by JAXA and Mitsubishi Heavy Industries, flying nine successful HTV cargo missions to the ISS from 2009 to 2020.

H-infinity control

H-infinity control, or H∞ control, is a branch of control theory that designs feedback controllers minimizing worst-case disturbance gain, formulated by George Zames in 1981.

Sep 29, 2026

H-infinity filtering

H-infinity filtering is a robust state-estimation method that reconstructs a dynamic system's states from noisy measurements while minimizing worst-case error from disturbances, without requiring any statistical model of the noise.

H. B. Robinson nuclear power plant

The H. B. Robinson nuclear power plant is a Duke Energy nuclear station near Hartsville, South Carolina, operating since 1971 with one Westinghouse pressurized water reactor.

Oct 10, 2026

H. J. Round

H. J. Round (Henry Joseph Round) was a British radio engineer at Marconi who in 1907 first reported electroluminescence, the effect behind the LED, and held 117 patents.

H. Jerry Qi

H. Jerry Qi (Hang Qi) is a Woodruff Professor of mechanical engineering at Georgia Tech, known for 4D printing, shape-memory polymers, and 3D printing of soft active materials.

H. Kent Bowen

H. Kent Bowen, born Harvey Kent Bowen, was an American ceramics scientist elected to the National Academy of Engineering in 1986 who taught at MIT and Harvard Business School.

H. L. Hunley

The H. L. Hunley was a hand-powered Confederate submarine of the Civil War, built in 1863 and the first submarine to sink an enemy warship, USS Housatonic, in 1864.

H. L. Hunt

H. L. Hunt (Haroldson Lafayette Hunt) was an American oil tycoon who bought the East Texas field's discovery leases in 1930, becoming the country's richest man.

H. Polat Gülkan

H. Polat Gülkan, full name Hakkı Polat Gülkan, is a Turkish earthquake engineer, professor at Başkent University elected to the US National Academy of Engineering in 2023.

H. T. Kung

H. T. Kung (孔祥重), full name Hsiang-Tsung Kung, is a computer scientist, the William H. Gates Professor at Harvard, known for systolic arrays and concurrency control.

H. Van Swygenhoven

Helena Van Swygenhoven, born 1955, is a Belgian materials scientist who studies how nanocrystalline metals deform, leading a research group at the Paul Scherrer Institute in Switzerland.

Sep 20, 2026

H. Vincent Poor

H. Vincent Poor, born Harold Vincent Poor, is an American electrical engineer and Princeton professor known for work in signal processing, information theory, and wireless networks.

H.‐S. Philip Wong

H.-S. Philip Wong is a Stanford electrical engineering professor who works on nanoscale semiconductor devices, solid-state memory, and carbon nanotube electronics, after 16 years at IBM.

H.263

H.263 is an ITU-T video coding standard titled Video coding for low bit rate communication, completed in 1995 as a successor to H.261 for videoconferencing and mobile video.

H.264/MPEG-4 AVC

H.264/MPEG-4 AVC, or MPEG-4 Part 10, is a video compression standard developed jointly by ITU-T and ISO/IEC, first completed in May 2003 and widely used in digital television.

H.323

H.323 is an ITU-T standard, first approved in 1996, for real-time audio, video, and data over packet-based networks; it was the main IP telephony and videoconferencing protocol before SIP.

Oct 22, 2026

H.E.S.S. II

H.E.S.S. II, also called CT5, is the fifth and largest telescope of the H.E.S.S. array in Namibia, a 28-meter Cherenkov telescope that began observing gamma rays in 2012.

H.J. Gruy

H.J. Gruy, known as Hank Gruy, was an American petroleum engineer who founded H.J. Gruy and Associates and joined the National Academy of Engineering in 1989.

H13 tool steel

H13 tool steel is a chromium hot-work tool steel, alloyed with chromium, molybdenum, and vanadium, and the most widely used grade for aluminum, magnesium, and zinc die-casting dies.

H2 Mobility

H2 Mobility is a German company founded in 2015 by six industrial firms including Air Liquide, Daimler, and Shell to build a nationwide hydrogen refuelling network.

Oct 26, 2026

H2O.ai

H2O.ai: Mountain View AI company founded 2012 by SriSatish Ambati; maker of H2O-3 open-source AutoML, Driverless AI, and h2oGPT; raised $251M, valued $1.7B in 2021.

H2S (radar)

H2S was a British airborne ground-mapping radar of the Second World War, developed by a team led by Bernard Lovell, that let RAF bombers navigate and bomb above cloud.