Exceptional superionic conductivity in disordered sodium decahydro-closo-decaborate.

Na2 B10 H10 exhibits exceptional superionic conductivity above ca. 360 K (e.g.

Sodium superionic conduction in Na2B12H12.

Impedance measurements indicate that Na2B12H12 exhibits dramatic Na(+) conductivity (on the order of 0.1 S cm(-1)) above its order-disorder phase-transition at ≈529 K, rivaling that of current, solid-state, ceramic-based, Na-battery electrolytes. Superionicity may be aided by the large size, quasispherical shape, and high rotational mobility of the B12H12(2-) anions.

Hydrogen dynamics in Ce2Fe17H5: inelastic and quasielastic neutron scattering studies.

The vibrational spectrum of hydrogen and the parameters of H jump motion in the rhombohedral Th(2)Zn(17)-type compound Ce(2)Fe(17)H(5) have been studied by means of inelastic and quasielastic neutron scattering. It is found that hydrogen atoms occupying interstitial Ce(2)Fe(2) sites participate in the fast localized jump motion over the hexagons formed by these tetrahedral sites. The H jump rate τ(-1) of this localized motion is found to change from 3.

Low-temperature tunneling and rotational dynamics of the ammonium cations in (NH4)2B12H12.

Low-temperature neutron scattering spectra of diammonium dodecahydro-closo-dodecaborate [(NH(4))(2)B(12)H(12)] reveal two NH(4)(+) rotational tunneling peaks (e.g., 18.

Reorientational dynamics of the dodecahydro-closo-dodecaborate anion in Cs2B12H12.

Rapid reorientational motions of the B(12)H(12)(2-) icosahedral anion, a key intermediate in borohydride dehydrogenation, are revealed by quasielastic neutron scattering (QENS) measurements of Cs(2)B(12)H(12) between 430 and 530 K. At 430 K, over the range of momentum transfers collected, the elastic incoherent structure factor (EISF) is consistent with a model for reorientational jumps about a single molecular axis. At temperatures of 480 K and higher, however, the EISF suggests the emergence of multiaxis reorientation by dynamically similar, independent jumps about two axes, on average, preserving crystallographic order.

A neutron scattering study of hydrogen dynamics in coarse-grained and nanostructured ZrCr₂H₃.

The vibrational spectra of hydrogen and parameters of H diffusion in the coarse-grained C15-type system ZrCr(2)H(3) and in nanostructured ZrCr(2)H(3) have been studied by means of inelastic and quasielastic neutron scattering. It is found that the diffusive motion of hydrogen in coarse-grained ZrCr(2)H(3) can be described in terms of at least two jump processes: a fast localized H motion with the jump rate τ(l)( - 1) over the hexagons formed by interstitial Zr(2)Cr(2) sites and a slower process with the rate τ(d)( - 1) associated with H jumps leading to long-range diffusion. While τ(d)( - 1)(T) in the range 250-380 K follows the Arrhenius law with the activation energy of 142 ± 4 meV, the temperature dependence of τ(l)( - 1) deviates from Arrhenius behavior.

Sodium magnesium amidoborane: the first mixed-metal amidoborane.

The first example of a mixed-metal amidoborane Na(2)Mg(NH(2)BH(3))(4) has been successfully synthesized. It forms an ordered arrangement in cation coordinations, i.e.

Enterprise-wide effort brings patient perspective into mix.

The National Patient Safety Foundation presented its 2009 Socius Award to the Medical College of Georgia (MCG Health). The award was given in recognition of the positive manner in which MCG Health collaborates with patients and families. The success achieved by MCG Health detailed in this article can motivate other hospital leaders, and the examples of collaboration can serve as templates for developing similar programs.

Size effects on the hydrogen storage properties of nanoscaffolded Li3BN2H8.

The use of Li3BN2H8 complex hydride as a practical hydrogen storage material is limited by its high desorption temperature and poor reversibility. While certain catalysts have been shown to decrease the dehydrogenation temperature, no significant improvement in reversibility has been reported thus far. In this study, we demonstrated that tuning the particle size to the nanometer scale by infiltration into nanoporous carbon scaffolds leads to dramatic improvements in the reversibility of Li3BN2H8.

Quasi-free methyl rotation in zeolitic imidazolate framework-8.

Using neutron inelastic scattering and diffraction, we have studied the quantum methyl rotation in zeolitic imidazolate framework-8 (ZIF-8: Zn(MeIM)(2), MeIM = 2-methylimidazolate). The rotational potential for the CH(3) groups in ZIF-8 is shown to be primarily 3-fold in character. The ground-state tunneling transitions at 1.

Structure of the novel ternary hydrides Li4Tt2D (Tt=Si and Ge).

The crystal structures of newly discovered Li4Ge2D and Li4Si2D ternary phases were solved by direct methods using neutron powder diffraction data. Both structures can be described using a Cmmm orthorhombic cell with all hydrogen atoms occupying Li6-octahedral interstices. The overall crystal structure and the geometry of these interstices are compared with those of other related phases, and the stabilization of this novel class of ternary hydrides is discussed.

Spin fluctuations in a magnetically frustrated metal LiV(2)O(4).

Inelastic neutron scattering is used to characterize spin fluctuations in the d-electron heavy fermion spinel LiV(2)O(4). The spin-relaxation rate, gamma(Q), for Q = 0.6 A(-1) is 1.

Materials Research With Neutrons at NIST.

The NIST Materials Science and Engineering Laboratory works with industry, standards bodies, universities, and other government laboratories to improve the nation's measurements and standards infrastructure for materials. An increasingly important component of this effort is carried out at the NIST Center for Neutron Research (NCNR), at present the most productive center of its kind in the United States. This article gives a brief historical account of the growth and activities of the Center with examples of its work in major materials research areas and describes the key role the Center can expect to play in future developments.

The NIST Cold Neutron Research Facility.

The Cold Neutron Research Facility (CNRF) at the National Institute of Standards and Technology (NIST) Research Reactor (NBSR) is now coming on line, with the first seven experimental stations operational, and more stations scheduled to be installed during 1992. The present article provides an introduction to the facility, and to other articles in the current issue that give more details on some of the research opportunities that the facility will bring to NIST.

Plain abdominal radiography in the detection of acute medical and surgical disease in children: a retrospective analysis.

A retrospective review was performed to determine the utility of plain abdominal radiographs in evaluating children presenting to the emergency department. Clinical features, radiographic interpretation, and final diagnoses of 431 patients seen over one year were recorded. One hundred three (24%) patients had major diseases (ventriculoperitoneal shunt malfunction, foreign body ingestion, appendicitis, intussusception, bowel obstruction, necrotizing enterocolitis, toxic megacolon, blunt abdominal trauma, pyloric stenosis, and Hirschsprung's disease), while the remaining 328 (76%) had minor diseases.