All articles A–Z
519,064 articles
Hot water extraction
Hot water extraction, also called autohydrolysis or liquid hot water pretreatment (LHW), uses heated pressurized water alone to dissolve hemicelluloses from lignocellulosic biomass, needing no added chemicals or neutralization.
Hot water pretreatment
Hot water pretreatment, also called liquid hot water (LHW) pretreatment, cooks lignocellulosic biomass in pressurized water at 160–240 °C to dissolve hemicellulose and make cellulose accessible for bioethanol production.
Hot Wheels
Hot Wheels is an American brand of die-cast toy cars and track sets produced by Mattel and first sold in 1968, known for speed, stunts, and orange plastic track.
Hot Wind
Hot Wind (热风) is the first collection of zawen, short critical essays, by the Chinese writer Lu Xun, published by Beixin Book Company in Beijing in 1925.
Hot yoga
Hot yoga: yoga practiced in rooms of 95–104°F (35–40°C), including Bikram's 26-posture, 90-minute sequence created by Bikram Choudhury; covers physiology, calorie burn, safety, and pregnancy guidance.
Hot Young Bloods (피끓는 청춘)
Hot Young Bloods (피끓는 청춘, Pikkeulneun Chungchoon) is a 2014 South Korean comedy-romance directed by Lee Yeon-woo, set in 1980s Hongseong, starring Park Bo-young and Lee Jong-suk; 1,676,040 admissions.
Hot-carrier cooling
Hot-carrier cooling is the process by which photoexcited electrons and holes lose excess energy to a semiconductor lattice by emitting phonons, typically within picoseconds; slow cooling in metal halide perovskites motivates hot-carrier solar cells.
Hot-carrier cooling bottleneck in halide perovskites
The hot-carrier cooling bottleneck in halide perovskites is the unusually slow cooling of photoexcited carriers, extending to tens of picoseconds versus femtoseconds in conventional semiconductors, attributed mainly to a hot-phonon bottleneck.
Hot-carrier extraction in perovskites
Hot-carrier extraction in perovskites collects photoexcited carriers before they lose excess energy as heat, a route toward solar cells exceeding the Shockley–Queisser limit, with extraction efficiencies up to about 80%.
Hot-carrier multiplication in graphene
Hot-carrier multiplication in graphene is an ultrafast many-particle process in which a single absorbed high-energy photon creates multiple charge carriers via Auger scattering, enabled by graphene's gapless, linear band structure.
Hot-carrier solar cell
A hot-carrier solar cell is a proposed photovoltaic device that extracts photoexcited carriers before they cool, proposed by Ross and Nozik in 1982 with a theoretical efficiency of 66%.
Hot-dip galvanization
Hot-dip galvanization, also called hot-dip galvanizing, is the most common method of protecting steel from corrosion, immersing it in a molten zinc bath at around 450 °C.
Hot-injection synthesis
Hot-injection synthesis, or hot injection, is a nanocrystal preparation method in which precursors are rapidly injected into a hot ligand-containing solvent, giving monodisperse quantum dots.
Hot-injection synthesis of CsPbX3 perovskite nanocrystals
Hot-injection synthesis of CsPbX3 perovskite nanocrystals is a colloidal method, first reported in 2015 by Protesescu and co-workers, that makes color-tunable cesium lead halide nanocrystals used in displays.
Hot-melt adhesive
Hot-melt adhesive, also known as hot glue or hotmelt, is a solvent-free thermoplastic adhesive applied molten at 120–180 °C that bonds as it cools, widely used in packaging and bookbinding.
Hot-phonon bottleneck in lead-halide perovskites
The hot-phonon bottleneck in lead-halide perovskites is a slowdown of hot-carrier cooling caused by reabsorbed hot optical phonons, discussed since 2015 as a route to hot-carrier solar cells.
Hot-spot ignition
Hot-spot ignition is the inertial confinement fusion scheme in which alpha-particle self-heating triggers a self-sustaining burn, first demonstrated at the National Ignition Facility in December 2022.
Hot-wire anemometry
Hot-wire anemometry is a technique for measuring fluid velocity in which an electrically heated fine wire is cooled by the flow, most often in the constant temperature mode.
Hot-wire method (thermal conductivity)
The hot-wire method is a transient technique for measuring thermal conductivity, in which a thin electrically heated wire embedded in the material acts as a line heat source.
Hot, dust-obscured galaxy
A hot, dust-obscured galaxy (Hot DOG) is a rare hyperluminous infrared galaxy discovered by the WISE satellite and powered by a heavily obscured, extremely luminous active galactic nucleus.
Hotai Motor
Hotai Motor Co., Ltd. (和泰汽車) is a Taiwanese automotive distributor representing Toyota, Lexus, Hino, and Yokohama Tire, founded in 1947 and Taiwan's leading vendor for more than 20 consecutive years.
HOTAIR
HOTAIR (HOX transcript antisense intergenic RNA) is a long non-coding RNA from the HOXC cluster that recruits PRC2 and LSD1 to repress HOXD genes in trans; its mouse knockout phenotype and PRC2 role are contested.
Hotaka-dake
Hotaka-dake (穂高岳), also Oku-Hotaka-dake, is a 3,190 m massif in Japan's Northern Alps on the Nagano–Gifu border, the country's third-highest peak, reached via Karasawa Cirque or the Daikiretto ridge from Yarigatake.
Hotan (خوتەن)
Hotan (خوتەن, historically Khotan, Chinese Yutian) is an oasis city in southwest Xinjiang, China, on the southern Silk Road at the edge of the Taklamakan Desert, famed for jade, silk, and its ancient Iranian-speaking Buddhist kingdom.
Hotarubi no Mori e (蛍火の杜へ)
Hotarubi no Mori e (蛍火の杜へ, Into the Forest of Fireflies' Light) is a 2011 44-minute Japanese anime film by Takahiro Omori and Brain's Base, adapting Yuki Midorikawa's 2002 LaLa DX manga about Hotaru and the untouchable Gin, made by the Natsume's Book of Friends staff.
HOTAS
HOTAS (Hands On Throttle And Stick) is a cockpit control concept that places vital switches on the throttle and control stick so pilots never let go, first used operationally in the early 1960s.
Hotchkiss M1909 Benét–Mercié machine gun
The Hotchkiss M1909 Benét–Mercié, also called the Hotchkiss Portative, was a French light machine gun designed by Laurence Benét and Henri Mercié and adopted in 1909 by France, Britain, and the United States.
Hotchkiss School
The Hotchkiss School is an independent boarding school in Lakeville, Connecticut, founded in 1891 by Maria Hotchkiss to prepare boys for Yale; coeducational since 1974, with 599 students, an 827-acre campus, and $13.9 million in financial aid.
Hote Hote Pyaar Ho Gaya
Hote Hote Pyaar Ho Gaya (होते होते प्यार हो गया), also spelled Hote Hote Pyar Hogaya, is a 1999 Hindi romantic drama directed by Firoz Irani, starring Kajol, Atul Agnihotri, Jackie Shroff, and Ayesha Jhulka; a box-office disaster with a one-star Times of India review.
Hotei Arcus
Hotei Arcus, an IAU-approved arcus feature on Titan at 28S 79W, 600 km across, named for the Japanese Buddhist god of happiness; a debated Cassini candidate cryovolcanic flow site.