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Longman Dictionary of Contemporary English
a nuclear/hydrogen bomb
▪ The North Koreans were developing a nuclear bomb.
hydrogen bomb
hydrogen peroxide
▪ These micro-refrigerators are commercially available, and avoid the explosion hazard of liquid hydrogen and the expense of liquid helium.
▪ We then start to accumulate liquid hydrogen in an empty fuel tank.
▪ Driving these cells were the contents of two liquid oxygen tanks and two liquid hydrogen tanks.
▪ Since most of the mass of Uranus air is hydrogen, most of the output from the refrigeration system is liquid hydrogen.
▪ Thus, this mission is so demanding that we are forced to use liquid hydrogen as the propellant.
▪ What had started out as a quest for metallic hydrogen now became a serious hunt for fusion.
▪ This incredibly dense, hot soup of protons and electrons is called fluid metallic hydrogen.
▪ Figure 9.9 shows the measured phase-diagram of molecular hydrogen.
▪ The equation of state of molecular hydrogen at high pressures and temperatures is particularly important and yet it is poorly known.
▪ These bacteria use molecular hydrogen as well as other electron donors, for the dissimilatory reduction of sulphate to sulphide.
▪ The extreme ultraviolet power was only a few watts, but it was adequate to detect molecular hydrogen.
▪ These studies confidently predict that at any plausible temperatures in Jupiter no solid molecular hydrogen surface is encountered.
▪ By supplying addition molecules of chlorine it is possible to replace all the hydrogen atoms.
▪ The optimum proportions of hydrogen and oxygen are thus two hydrogen atoms per oxygen atom, exactly the same as in water.
▪ This is about the energy that would be released if a hydrogen atom could be totally converted into energy.
▪ A methyl group is a carbon with three hydrogen atoms attached.
▪ One of the hydrogen atoms in ammonia is replaced by a benzene ring.
▪ Instantly, one of the hydrogen atoms on the ethanol molecule is ripped off.
▪ It consists of a chain of carbon atoms, with one hydrogen atom attached to each carbon.
▪ The microcosm becomes the macrocosm: the key to the whole universe may well be hidden in one hydrogen atom.
▪ The large scale release of fusion energy has so far occurred only in stars and in the hydrogen bomb.
▪ On 12 July 1953, when the Soviet Union exploded its first hydrogen bomb, equilibrium was restored.
▪ Might it not be the equivalent of a small hydrogen bomb?
▪ The main source of helium-3 is in fact hydrogen bomb recycling!
▪ The heat released in this reaction, which is like a controlled hydrogen bomb explosion, is what makes the star shine.
▪ The largest accessible source of helium-3 on Earth is from the decay of tritium in hydrogen bombs.
▪ In spite of the situation we find ourselves in, maybe hydrogen bombs aren't the biggest cause for concern.
▪ The Soviet Union tested its own hydrogen bomb within a year, and the nuclear arms race escalated further.
▪ Glutamic acid 170 forms the final main-chain hydrogen bond in the molecule.
▪ Glu115 also forms hydrogen bonds to His118 and to Asp84, and Glu238 hydrogen-bonds to Glu204.
▪ This allows hydrogen bonds to reform.
▪ Protein residues in contact are also shown, with hydrogen bonds as dotted lines.
▪ Distortions due to the formation of hydrogen bonds are usually smaller than those due to co-ordination to metal ions.
▪ There are no main-chain hydrogen bonds to the metal ligand side chains.
▪ For clarity, the three hydrogen bonds mentioned in the text are not illustrated.
▪ The transient nature of the binding may be because this sequence is recognized on account of its structure without additional hydrogen bonding contacts.
▪ These unusual chemical shifts for imino and amino protons are indicative of novel hydrogen bonding.
▪ It is now believed that the peculiar properties of water are due to what is known as hydrogen bonding.
▪ The energy of this hydrogen bonding is comparable to that of the torsion-angle strain.
▪ After ingestion of sucrose, breath hydrogen was measured at 20 minute intervals for 160 minutes.
▪ If during this period breath hydrogen increased by 100% or more the test was considered abnormal.
▪ If after four hours no such a rise in breath hydrogen occurred, the transit time was recorded as 240 minutes.
▪ The mean breath hydrogen curves after acarbose, miglitol, and placebo are shown in Figure 1.
▪ Subsequent detailed analyses of the motions of the atomic hydrogen gas in the plane supported this proposal.
▪ The very same process, operating on water instead of carbon dioxide, makes oxygen and hydrogen gas.
▪ Anhydrous caustic soda, hydrogen gas and phosgene, all well established product areas, are being developed to produce maximum returns.
▪ The cells will drive electric motors and use on-board hydrogen gas as fuel.
▪ The hydrogen gas would be collected within the galls and piped to a central storage system.
▪ Fresh hydrogen gas is charged to the inlet of the reactor to balance consumption.
▪ The whole system is rich in hydrogen gas.
▪ The gas phase is recycled to the reactor inlet to provide a large excess of hydrogen gas in the catalytic reaction zone.
▪ Proton concentrations for each sample were then calculated from the hydrogen ion activity and the combined sodium and potassium concentrations.
▪ Treatment is aimed at decreasing hydrogen ion loss.
▪ The principal body electrolytes are sodium, potassium and hydrogen ions.
▪ Diuretics should be stopped, if possible, to decrease renal hydrogen ion loss.
▪ Bennett and Williams suggest that the cells of opening or closing traps acidify their own walls by releasing hydrogen ions.
▪ This is a symbol expressing hydrogen ion concentration in a solution; it is a measure of relative acidity or alkalinity.
▪ The timing of active hydrogen ion secretion, however, remains unknown.
▪ Hypocapnia causes fewer hydrogen ions to be available for secretion in the renal tubular cell.
▪ A biochemist colleague has kindly provided me with a bottle of hydrogen peroxide, and enough hydroquinone for 50 bombardier beetles.
▪ Ultraviolet light, hydrogen peroxide and ozone assure crystal-clear, clean water.
▪ Abrasions are sprayed with hydrogen peroxide.
▪ I poured the hydrogen peroxide into the hydroquinone, and absolutely nothing happened.
▪ But hydrogen peroxide and hydroquinone don't react violently together unless a catalyst is added.
▪ The variability of patterns resulting from the use of different volumes of hydrogen peroxide also argued against further use of this technique.
▪ This method is used for the reactions of metals and acids and the decomposition of hydrogen peroxide.
▪ Finally, we should comment on the relative abundance of ozone and hydrogen peroxide at Cape Grim.
▪ The first primitive forms of life consumed various materials, including hydrogen sulfide, and released oxygen.
▪ If hydrogen sulfide or some other poisonous gas is detected, Donahue dons an airtight breathing device and a hard hat.
▪ Vent water is enriched in reduced chemical compounds, especially hydrogen sulfide.
▪ Sulphur bacteria may be present below the anoxic zone, reducing sulphate ions and liberating hydrogen sulphide.
▪ So the sewage goes septic, giving off hydrogen sulphide which corrodes the pipes and makes a nasty smell.
▪ These included methane, ammonia, probably hydrogen cyanide, hydrogen sulphide and carbon monoxide.
▪ Instead of splitting hydrogen sulphide, they developed the ability to split water by first trapping solar energy in green pigments.
▪ The outlet can contain nitrite or hydrogen sulphide.
▪ Gas compositions are normalised to exclude hydrogen sulphide because of poor analytical reproducibility for this gas.
▪ Apparently they were thriving on hydrogen sulphide from the rotting beams of the ship.
▪ Later in the spoilage process other components, such as the sulphurous notes from hydrogen sulphide, may add to the smell.
▪ Like Green's compound, this iridium compound contains two hydrogen atoms that can be eliminated by light.
▪ Scientists assume that those planets' high-pressure cores contain metal hydrogen.
▪ Carbohydrates in pure form contain only carbon, hydrogen, and oxygen.
▪ The outlet can contain nitrite or hydrogen sulphide.
▪ In general coals contain carbon, hydrogen, oxygen, nitrogen and sulphur with various other trace elements.
▪ Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, and phosphorus.
▪ Glu115 also forms hydrogen bonds to His118 and to Asp84, and Glu238 hydrogen-bonds to Glu204.
▪ In any plausible way of forming Jupiter the hydrogen and helium are initially well mixed at a molecular level.
▪ Charged residues are only occasionally found in the interior, where they form hydrogen bonds to oppositely charged residues or main-chain atoms.
▪ These polymers can form intermolecular hydrogen bonds which greatly enhance crystallite stability.
▪ However, at present, the economics of using solar-produced electricity to produce hydrogen from water by electrolysis are poor.
▪ These bacteria use molecular hydrogen as well as other electron donors, for the dissimilatory reduction of sulphate to sulphide.
▪ The cells will drive electric motors and use on-board hydrogen gas as fuel.
▪ For comparison with the alkaline phosphatase technique, we used 100 µl of hydrogen peroxide.
▪ Thus, this mission is so demanding that we are forced to use liquid hydrogen as the propellant.
▪ A biochemist colleague has kindly provided me with a bottle of hydrogen peroxide, and enough hydroquinone for 50 bombardier beetles.
▪ Expressed as the proportion of carbon to hydrogen, fuelwood is roughly 91 percent carbon.
▪ For all they know, metal hydrogen may always be unstable and quickly vaporize.
▪ In this case the presence of oxygen and hydrogen mixed in the optimum proportions, could well have compounded the effect.
▪ The large scale release of fusion energy has so far occurred only in stars and in the hydrogen bomb.
▪ The transient nature of the binding may be because this sequence is recognized on account of its structure without additional hydrogen bonding contacts.
▪ The vaporized gasoline is processed into hydrogen, water and carbon dioxide.
▪ Ultraviolet light, hydrogen peroxide and ozone assure crystal-clear, clean water.
The Collaborative International Dictionary

Hydrogen \Hy"dro*gen\, n. [Hydro-, 1 + -gen: cf. F. hydrog[`e]ne. So called because water is generated by its combustion. See Hydra.] (Chem.) A gaseous element, colorless, tasteless, and odorless, the lightest known substance, being fourteen and a half times lighter than air (hence its use in filling balloons), and over eleven thousand times lighter than water. It is very abundant, being an ingredient of water and of many other substances, especially those of animal or vegetable origin. It may by produced in many ways, but is chiefly obtained by the action of acids (as sulphuric) on metals, as zinc, iron, etc. It is very inflammable, and is an ingredient of coal gas and water gas. It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad. Symbol H. Atomic weight 1.

Note: Although a gas, hydrogen is chemically similar to the metals in its nature, having the properties of a weak base. It is, in all acids, the base which is replaced by metals and basic radicals to form salts. Like all other gases, it is condensed by great cold and pressure to a liquid which freezes and solidifies by its own evaporation. It is absorbed in large quantities by certain metals (esp. palladium), forming alloy-like compounds; hence, in view of quasi-metallic nature, it is sometimes called hydrogenium. It is the typical reducing agent, as opposed to oxidizers, as oxygen, chlorine, etc.

Bicarbureted hydrogen, an old name for ethylene.

Carbureted hydrogen gas. See under Carbureted.

Hydrogen dioxide, a thick, colorless liquid, H2O2, resembling water, but having a bitter, sour taste, produced by the action of acids on barium peroxide. It decomposes into water and oxygen, and is manufactured in large quantities for an oxidizing and bleaching agent. Called also oxygenated water.

Hydrogen oxide, a chemical name for water, H?O.

Hydrogen sulphide, a colorless inflammable gas, H2S, having the characteristic odor of bad eggs, and found in many mineral springs. It is produced by the action of acids on metallic sulphides, and is an important chemical reagent. Called also sulphureted hydrogen.

Douglas Harper's Etymology Dictionary

1791, from French hydrogène, coined 1787 by G. de Morveau, Lavoisier, Berthollet, and Fourcroy from Greek hydr-, stem of hydor "water" (see water (n.1)) + French -gène "producing" (see -gen). So called because it forms water when exposed to oxygen. Nativized in Russian as vodorod; in German, it is wasserstoff, "water-stuff." An earlier name for it in English was Cavendish's inflammable air (1767). Hydrogen bomb first recorded 1947; shortened form H-bomb is from 1950.


n. 1 The lightest chemical element (''symbol'' H) with an atomic number of 1 and atomic weight of 1.00794. 2 Molecular hydrogen (H2), a colourless, odourless and flammable gas at room temperature. 3 An atom of the element. 4 A sample of the element.


n. a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe [syn: H, atomic number 1]

Hydrogen (software)

Hydrogen is an open source drum machine created by Alessandro Cominu, an Italian programmer who goes by the pseudonym Comix. Its main goal is to provide professional yet simple and intuitive pattern-based drum programming.

Hydrogen was originally developed for Linux, but later ported to Mac OS X. Support for Microsoft Windows seemed to have been abandoned, since the last build dated to 2006 for 4 years. However, a Windows port exists since the 0.9.6 version, and it is now in beta stage. The graphical user interface for the application uses Qt library, and all code is released under the GNU General Public License.

Hydrogen (disambiguation)

Hydrogen is a chemical element.

Hydrogen may also refer to:

  • Hydrogen atom
  • Hydrogen ion
  • Hydrogen (software), drum machine software
  • Hydrogen vehicle
  • Isotopes of hydrogen
    • Hydrogen-2 (deuterium)
    • Hydrogen-3 (tritium)
    • Hydrogen-4
    • Hydrogen-5

Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of , hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Non- remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol H), has one proton and no neutrons.

The universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions because most acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics.

Hydrogen gas was first artificially produced in the early 16th century by the reaction of acids on metals. In 1766–81, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, and that it produces water when burned, the property for which it was later named: in Greek, hydrogen means "water-former".

Industrial production is mainly from steam reforming natural gas, and less often from more energy-intensive methods such as the electrolysis of water. Most hydrogen is used near the site of its production site, the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market. Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks.

Hydrogen (horse)

Hydrogen was a champion Australian thoroughbred racehorse.

By the imported stallion Delville Wood (who also sired Melbourne Cup winner Evening Peal) he was foaled in 1948 and was trained throughout his career by Ted Hush.

Hydrogen failed by a neck of being the first horse to win three Cox Plates when beaten in 1951 as a three-year-old. He won the subsequent two editions of the race in 1952 and 1953.

An outstanding three-year-old he developed into one of Australia’s finest weight-for-age performers and the highest stakes earner at the time eclipsing the record previously held by Phar Lap.

A winner over six furlongs (1,200m) to two miles (3,200m) he won many major races including the 1951 VATC Caulfield Guineas, 1951 VRC Victoria Derby, 1951 STC Rosehill Guineas, 1951 AJC Craven Plate, the 1952 and 1953 MVRC W.S. Cox Plate, 1953 VRC LKS Mackinnon Stakes and the 1953 QTC Brisbane Cup.

He was retired to stud in 1954.

Usage examples of "hydrogen".

After passing through the catalytic reactors, the rare hydrogen allotrope was siphoned off, while the waste gases spilled back out from the hot stacks.

Railgun launchers shot barrels of pure hydrogen ice up to a drifting ekti reactor that would catalyze the hydrogen into ekti, the valuable allotrope used as stardrive fuel.

Through catalysts and convoluted magnetic fields, the reactors converted ultrapure hydrogen into an exotic allotrope of hydrogen.

Ekti was the only known allotrope of hydrogen, though other elements had varying molecular forms.

The scoops and reactors had operated continuously for dozens of centuries, producing the hydrogen allotrope, though in recent years, it was only a token amount.

Its industrial systems were outdated and inefficient by now, but processing of the hydrogen allotrope continued.

Anyway, copious quantities of hydrogen gas were pouring from the shaft maw, coming from the rent where the unfortunate brown man had fallen into a ballonet and suffocated.

Vents on the upper surface of the ship were opening, releasing hot air from the ballonets that hung in the center of the hydrogen cells.

Margo trimmed their attitude by adjusting the amount of ordinary air contained in ballonets inside the hydrogen bag.

She felt light, as if the hydrogen in the ballonets had filled her as well.

Their own supply of breathing hydrogen, while not yet critically low, is causing them and the distant Benj more and more concern.

Treat this with excess of bisulphate of sodium, then saturate with sulphuretted hydrogen until metals are thrown down as sulphides.

This was out of respect for the human nose, for from the Diaboli, slightly so as they breathed, much more so when they spoke, there came the gentle and continuous drift of hydrogen sulfide.

Removed by oxidation of all the the hydrogen organs of of proteids, excretion, carbohydrates, but in the and fats.

May 6, 1937, in Lakehurst, New Jersey, when its hydrogen fuel burst explosively into flame, killing thirty-six people.