70 resultados para Structural Constraints of Kind (Min, Max)
Resumo:
This paper reports the progress made at JET-ILW on integrating the requirements of the reference ITER baseline scenario with normalized confinement factor of 1, at a normalized pressure of 1.8 together with partially detached divertor whilst maintaining these conditions over many energy confinement times. The 2.5 MA high triangularity ELMy H-modes are studied with two different divertor configurations with D-gas injection and nitrogen seeding. The power load reduction with N seeding is reported. The relationship between an increase in energy confinement and pedestal pressure with triangularity is investigated. The operational space of both plasma configurations is studied together with the ELM energy losses and stability of the pedestal of unseeded and seeded plasmas. The achievement of stationary plasma conditions over many energy confinement times is also reported.
Resumo:
The structure of the (2 X 1)CO-Pd(110) surface phase has been determined by LEED intensity analysis. The CO molecule is found to be adsorbed in an atop site, tilted by 11-degrees +/- 4-degrees with respect to the surface normal, with a C-O bond length of 1.16 +/- 0.04 angstrom. Interestingly, the C-O vibrational frequency for this system (2003 cm-1) is virtually identical to the frequency observed for the (2 X 1)CO-Ni(110) surface phase (1998 cm-1) which a previous LEED study has shown involves bridge bound CO molecules. The result indicates that care must be taken in assigning site symmetries on the basis of C-O stretching frequencies alone.
Resumo:
Molecularly adsorbed CO on Pd{110} has been shown (R. Raval et al., Chem. Phys. Lett. 167 (1990) 391, ref. [1]) to induce a substantial reconstruction of the surface in the coverage range 0.3 <theta less-than-or-equal-to 0.75. Throughout this coverage range, the adsorbate-covered reconstructed surface exhibits a (4 x 2) LEED pattern. However, the exact nature of the reconstruction remains uncertain. We have conducted a LEED I(E) "fingerprinting" analysis of the CO/Pd{110}-(4 x 2) structure in order to establish the type of reconstruction induced in the metal surface. This study shows that the LEED I(E) profiles of the integral order and appropriate half-order beams of the CO/Pd{110}-(4 x 2) pattern closely resemble the I(E) profiles theoretically calculated for a Pd{110}-(1 x 2) missing-row structure. Additionally, there is a strong resemblance to the experimental LEED I(E) profiles for the Cs/Pd{110}-(1 x 2) structure which has also been shown to exhibit the missing-row structure. On the basis of this evidence we conclude that the CO/Pd{110}-(4 x 2) LEED pattern arises from a missing-row reconstruction of the Pd{110} surface which gives rise to a strong underlying (1 x 2) pattern plus a poorly ordered CO overlayer which produces weak, diffuse fourth-order spots in the LEED pattern.
Resumo:
In this paper the temperature and pressure induced paramagnetic switching of cobalt (II) complex in binary mixture of phosphonium based ionic liquid [P6,6,6,14]SCN and [Co(NCS)2], is reported. This arises from a structural change in the coordination of the cobalt (II) center from tetrahedral [Co(NCS)4]2- to octahedral [Co(NCS)6]4- when mobile thiocyanate ions are added. These properties are reflected in the abrupt change of conductivity behavior of the magnetic ionic liquid. Therefore, as demonstrated herein the reversible switching in coordination of cobalt from tetrahedral to octahedral can be easily monitored at ambient as well as elevated pressure by tracking the dc-conductivity changes.