All articles starting with H
20,046 articles
High-pressure chemistry
High-pressure chemistry is an interdisciplinary science using high-pressure experiments and theories to study interactions, reactions, and transformations among atoms or molecules, chiefly with diamond anvil cells.
High-pressure die casting
High-pressure die casting (HPDC) is a casting process that forces molten metal under pressure into a steel die, filling in a fraction of a second.
High-pressure differential scanning calorimetry
High-pressure differential scanning calorimetry (HP DSC) measures sample heat flow under elevated gas pressure, revealing how pressure shifts phase transitions and reaction rates in polymer, petrochemical, and food labs.
High-pressure electride
A high-pressure electride is a material that under extreme compression traps valence electrons in lattice voids, where they act as anions; compressed sodium becomes a transparent insulator above 200 GPa.
High-pressure fuel pump
A high-pressure fuel pump raises fuel from tank pressure to injection pressure in direct-injection engines, feeding the common rail; diesel systems reach up to 2,700 bar.
High-pressure grinding rolls
High-pressure grinding rolls (HPGR) are comminution machines that crush rocks and ores between two counter-rotating rollers, cutting grinding energy use by 20–40% in mining and cement.
High-pressure NMR
High-pressure NMR is nuclear magnetic resonance spectroscopy performed on samples inside a diamond anvil cell at pressures up to 202 GPa, notably probing hydrogen in metal hydrides studied as high-temperature superconductors.
High-pressure sodium lamp
The high-pressure sodium lamp (HPS lamp) is a high-intensity discharge lamp producing warm orange-white light, developed by General Electric and widely used for street lighting.
High-pressure torsion
High-pressure torsion is a severe plastic deformation technique that twists a metal disk under several gigapascals of pressure, refining its grains to raise strength and hardness.
High-pressure water scrubbing
High-pressure water scrubbing is a biogas upgrading technology that removes carbon dioxide by dissolving it in pressurized water, historically the most widely used upgrading method worldwide.
High-pressure X-ray diffraction
High-pressure X-ray diffraction is the measurement of X-ray diffraction patterns from crystalline samples under elevated pressure, usually in a diamond anvil cell, to determine structure, equation of state, and phase transitions.
High-Protein Low-Carbohydrate Diet
High-protein low-carbohydrate diet (Atkins, South Beach): eating pattern high in protein, under 45% energy from carbohydrate, used for weight loss and type 2 diabetes; modest short-term benefit, little long-term advantage over balanced diets.
High-purity germanium detector
A high-purity germanium (HPGe) detector is a semiconductor radiation detector, cooled with liquid nitrogen, that measures gamma-ray and X-ray energies with very high resolution; it succeeded the Ge(Li) detector.
High-redshift galaxy
A high-redshift galaxy is one whose light was emitted when the universe was young and stretched by expansion, studied mainly with Hubble and the James Webb Space Telescope.
High-redshift protocluster
A high-redshift protocluster is a concentration of galaxies and dark matter at an early cosmic epoch that is the progenitor of a present-day galaxy cluster, before the members collapse into one bound structure.
High-redshift quasar
A high-redshift quasar is a quasar, an active nucleus powered by a supermassive black hole, seen at redshift z above 6, within the Universe's first billion years.
High-resolution anoscopy
High-resolution anoscopy (HRA) is a colposcopic examination of the anal canal that detects precancerous lesions, the preferred method for anal cancer screening in high-risk groups.
High-resolution audio
High-resolution audio (Hi-Res Audio) is a class of digital audio formats whose sampling rates and bit depths exceed the compact disc's, typically 96 kHz/24-bit PCM or DSD, with industry definitions adopted in 2014.
High-resolution electron energy loss spectroscopy
High-resolution electron energy loss spectroscopy (HR-EELS), also known as vibrational electron energy loss spectroscopy, is an electron microscopy technique that detects vibrational excitations, phonons, and light elements such as hydrogen.
High-resolution manometry
High-resolution manometry (HRM) is a diagnostic technique measuring pressure along the gut with up to 36 sensors about 1 cm apart, chiefly for esophageal motility disorders.
High-resolution mass spectrometry
High-resolution mass spectrometry (HRMS) is mass spectrometry using analyzers such as FT-ICR, Orbitrap, and time-of-flight that resolve closely spaced ion peaks and assign elemental compositions from accurate mass.
High-resolution melt analysis
High-resolution melt analysis (HRM, also HRMA) is a closed-tube real-time PCR method that detects DNA variants, genotypes SNPs, and estimates methylation without sequencing or labeled probes.
High-resolution melting analysis
High-resolution melting analysis (HRM), also called high-resolution melting curve analysis, is a closed-tube molecular biology method that detects DNA variants, genotypes, and methylation differences by monitoring PCR amplicon melting.
High-resolution microendoscopy
High-resolution microendoscopy (HRME) is a fluorescence imaging technique that passes a miniature fiber-bundle probe through a standard endoscope to image epithelial tissue at cellular resolution in real time.
High-resolution peripheral quantitative computed tomography
High-resolution peripheral quantitative computed tomography (HR-pQCT) is a low-dose X-ray method for imaging the distal radius and tibia in vivo to quantify bone microstructure and volumetric density.
High-Resolution Rapid Refresh
The High-Resolution Rapid Refresh (HRRR) is a NOAA numerical weather prediction model that runs hourly at 3-km resolution across the United States, operational since 2014.
High-resolution resonant inelastic X-ray scattering
High-resolution resonant inelastic X-ray scattering (high-resolution RIXS) is an X-ray spectroscopy technique that measures the energy and momentum of excitations such as magnons and phonons with tens-of-millielectronvolt resolution.
High-resolution transmission electron microscopy
High-resolution transmission electron microscopy (HRTEM) is a technique that forms phase-contrast images of atomic lattices in thin specimens, used to study defects, interfaces, and nanoparticles in materials science.
High-resolution X-ray diffraction of epitaxial layers
High-resolution X-ray diffraction (HRXRD) is a branch of X-ray diffraction that uses highly monochromatic beams to measure composition, thickness, strain, relaxation, and defect broadening in single-crystalline epitaxial layers, an essential semiconductor characterization tool.
High-Rise (film)
High-Rise (2015) is Ben Wheatley's film adaptation of J.G. Ballard's 1975 novel, scripted by Amy Jump, starring Tom Hiddleston, Jeremy Irons, Sienna Miller, Luke Evans, and Elisabeth Moss; developed for 40 years by producer Jeremy Thomas, premiered at TIFF 2015, released in the UK 18 March 2016.