Hydrogen and its isotopes

Tritium and its decay product, helium, change the structural properties of stainless steels and make them more susceptible to cracking. Tritium embrittlement is an enhanced form of hydrogen embrittlement because of the presence of He from tritium decay which nucleates as nanometer-sized bubbles on dislocations, grain boundaries, and other microstructural defects. Steels with decay helium bubble microstructures are hardened and less able to deform plastically and become more susceptible to embrittlement by hydrogen and its isotopes (1-7). 

The only other particles that appear to tunnel atomic distances with chemical energies are hydrogen and its isotopes, deuterium and tritium. Because these particles... 

SIMS—The presence of hydrogen and its isotopes can be determined and some chemical information can be derived from the kinds of ionic fragments sputtered from the surface. 

For hydrogen and its isotopes (H2, HD, D2,...) in interaction with rare gas atoms or other hydrogen molecules, very accurate ab initio calculations exist that were shown to be in agreement with the known measurements of binary spectra the calculated dipole functions are as good as, or possibly better than, the best empirical models and will be discussed in the next Section. 

Fusion is what powers the Sun and stars. One type of fusion reaction involves the combination of two "heavy" isotopes of hydrogen. Isotopes of an element have the same number of protons, but a different number of neutrons. For example, hydrogen and its isotopes—deuterium and tritium—all have one proton in their nuclei. Remember that the number of protons plus the number of neutrons make up the mass of an atom. Because they have different numbers of neutrons, hydrogen, deuterium, and tritium have different masses. Deuterium has one proton and one neutron. It has a mass of 2 atomic mass units (amu). Deuterium can also be written as hydrogen-2. The number following the element s name is the isotope s mass. Tritium has one proton and two neutrons. So, tritium has a mass of 3 amu. Tritium can be written as hydrogen-3. 

The great advantage of neutron diffraction is that small nuclei like hydrogen are readily observed. By comparison with carbon and larger elements, hydrogen is a very weak X-ray diffractor and is typically not observable in electron-density maps of proteins. But hydrogen and its isotope deuterium (2H or D) diffract neutrons very efficiently in comparison with larger elements. 

Cercy, C., Tistchenko, S., Botter, F. The analytical separation of hydrogen and its isotopes by gas-solid elution chromatography on a capillary column. Bull. Soc. Chim. France 1962, 2315. 

In this article, we mainly discuss the properties and behavior of hydrogen and its isotopes, and present the various apphcations of hydrogen. Excellent reviews on hydrogen are given in reference books of inorganic chemistry. ... 

The simplest molecular solids are those of hydrogen and its isotopes, which are discussed in a recent monograph [659] and in various review articles [626, 633, 635, 638, 652, 653]. The spectra are related to the zero-point motion of the lattice, rotation, and translation. The phonon spectra observed in these quantum solids have been of special interest. 

Relatively few other compounds transfer growing polymer chains with coordination catalysts, but molecular hydrogen and its isotopes are effective. The transfer mechanism is... 

The density variation of the relaxation time has been most extensively studied in hydrogen and its isotopes " as data exist from just below the critical temperature of 33 K for H2 up to 400 K and from 30 to 80 K for D2. A small complication exists for hydrogen and its isotopes at low temperature due to the quantum nature of these systems, but this only affects the dynamics at low density and may be readily taken care of by the use of quantum pair functions in the gas, or classical equivalent well depths. ... 

Lu, T., Goldfield, E.M., and Gray, S.K. (2003). Quantum states of molecular hydrogen and its isotopes in single-waUed carbon nanotubes. J. Phys. Chem. B, 107, 12989-95. 

A.A. Khan et al.. Air Cleaning Engineering Research Section, Waste Management Division, BARC, Bombay. Removal of hydrogen and its isotopes from air-gas stream. Proceedings of CATSYMPO 80 - The fifth National Catalysis Symposium, held at RRL, Hyderabad, p90... 

Tosh et al. proposed the use of Pd/Ag-based membrane reactors for the recovery of hydrogen and its isotopes from tritiated water in a closed loop process that includes both the forward and reverse water-gas shift reactions [24]. The aim of this process was to avoid any production of tritiated wastes and any consumption of CO. In the system, the retentate stream, rich in CO2, was recycled to the reactor. The water-gas shift stops when all the water reacts and aU the hydrogen is recovered at the permeate side. Then, hydrogen is added, and the CO2 in the stream is completely converted to CO by the reverse water-gas shift reaction, thanks to the continuous removal of the produced water in a condenser. Figure 9.13 shows the proposed process. 

High chromium in martensitic steels have strengths comparable to austenitic steels up to 500°C and present a greater resistance to the effect of radiation damage. For this reason, it is important to obtain parameters such as the solubility and permeability of hydrogen and its isotopes. 

Nuclear Spin Contribution. The nuclear spin partition function is the product of the nuclear spin multiplicity 2ij -H 1) for all the atoms in the molecule, where /V is the nuclear spin of the yth atom. Since, apart from processes involving molecular hydrogen and its isotopes (and the transmutation of the elements), nuclear spins are conserved, this contribution is conventionally omitted from the total entropy leaving the practical or virtual entropy (these adjectives are frequently omitted also). 

In this presentation we will report on the total reactive cross section measurements of the reaction of F with molecular hydrogen and its isotopic variants, on some charge transfer processes and on the angular.and energy variation of the FD products from the reaction F (D2 D)FD. Som preliminary cross section measurements for some reactions of F with CH. will also be mentioned. 

A.S. Friedman and J. Hilsenrath, The Thermodynamic and Transport Properties of Liquid Hydrogen and Its Isotopes, Part I, National Bureau of Standards Report 3163 (March 15, 1954). 

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