Mn–Co spinel protective–conductive coating on AL453 ferritic stainless steel for IT-SOFC interconnect applications

This paper presents research on the synthesis and properties of the Mn_1.5Co_1.5O₄ (MC) spinel powder, as well as its application for the preparation of a MC thick film on the AL453 steel to be used for metallic interconnect material in IT-SOFCs. In order to prepare the MC micropowder with excellent homogeneity of the chemical and phase compositions, EDTA gel processes were utilized. In order to improve the contact electrical resistance between an AL453 steel interconnect and the La_0.8Sr_0.2FeO₃ (LSF) cathode and protect the cathode from Cr poisoning, the surface of the AL453 steel was coated with a protective manganese cobaltite spinel matrix using screen printing in combination with an appropriate heat treatment. The oxidation of the AL453/MC composite layer carried out in the air–H₂O gas mixture at 1,073 K for 55 h showed that the spinel coating may serve as an effective barrier against outward Cr diffusion from the AL453 steel and, therefore, significantly inhibit the formation of volatile Cr vapors from the chromia scale. The contact ASR study of the interconnect–cathode interface in the AL453/MC/LSCM/LSF/LSCM/MC/AL453 system carried out in the range of 723?1,073 K in air showed a very large drop in ASR compared to the resistance of the AL453/LSCM/LSF/LSCM/AL453 system without the spinel coating.     

Search for disoriented chiral condensate in 158<Emphasis Type="Italic">A</Emphasis> GeV Pb+Pb collisions in WA98 experiment

The current status of the search for localized domains of disoriented chiral condensates (DCC) in Pb+Pb collisions at 158A GeV/c are presented. A new method based on the discrete wavelet transformation (DWT) technique along with an analysis of correlation between charged and neutral particles has been used for the search of localized DCC domains. We show that both the methods indicate the presence of non-statistical fluctuations in data.     

Azimuthal anisotropy of photon and charged parti cle emissionin 208Pb + 208Pb collisions at 158 $\ cdot A$ GeV/ c

The azimuthal distributions of photons and charged particles with respect to the event plane are investigated as a function of centrality in ²⁰⁸Pb + ²⁰⁸Pb collisions at 158 GeV/c in the WA98 experiment at the CERN SPS. The anisotropy of the azimuthal distributions is characterized using a Fourier analysis. For both the photon and charged particle distributions the first two Fourier coefficients are observed to decrease with increasing centrality. The observed anisotropies of the photon distributions compare well with the expectations from the charged particle measurements for all centralities.Received: 22 May 2004, Revised: 14 April 2005, Published online: 4 May 2005PACS: 25.75.Dw     

Dilepton and trilepton production by antineutrinos and neutrinos in neon

A sample of over 25,000 fully measured neutrino and antineutrino charged current interactions in BEBC includes 192 dilepton candidates. The prompt signal after subtraction of background is 41 ±7µ⁺ e ^-, 35±7µ⁺µ^- events from \(\bar v\) interactions, and 32±7µ^-µ⁺ events from ν interactions. There are 2 trileptons, µ^-µ^- e ⁺ and µ^-µ^-µ⁺. Results are compared with other experimental data and with the standard model. Limits to prompt like sign µ⁺ e ⁺, µ⁺µ⁺ and µ^-µ^- signals are given and compared with other experiments and with theoretical calculations.     

A laser extraction/combustion technique for in situ delta(13)C analysis of organic and inorganic materials

A CO(2) laser extraction system is described for in situ delta(13)C analysis of organic and inorganic materials. Carbonaceous compounds volatilized by the laser are quantitatively converted to CO(2) gas by a combustion furnace mounted after the sample chamber. Gases produced by the laser and combustion processes are swept by helium carrier gas and separated by a packed gas chromatography column prior to their introduction to an isotope ratio monitoring mass spectrometer. A sample of lentil bean was analyzed at a spatial resolution of 200 μm and yielded delta(13)C values with precision of +/- 0.3 per thousand. The accuracy of delta(13)C measurements was better than +/- 0.5 per thousand from NBS 22 (mineral oil), USGS 24 (graphite), and IAEA CO-1 (calcium carbonate). Copyright 1999 John Wiley & Sons, Ltd.     

MHD modeling of conductors at ultrahigh current density

In conjunction with ongoing high-current experiments on Sandia National Laboratories' Z accelerator (Albuquerque, NM) we have revisited a problem first described in detail by Heinz Knoepfel (1970). Unlike the 1-Tesla MITL's of pulsed power accelerators used to produce intense particle beams, Z's disk, transmission line (downstream of the current addition) is in a 100-1200-Tesla regime; so its conductors cannot be modeled simply as static infinite conductivity boundaries. Using the MHD code MACH2 we have been investigating the conductor hydrodynamics, characterizing the joule heating, magnetic field diffusion, and material deformation, pressure, and velocity over a range of current densities, current rise-times, and conductor materials. The three purposes of this work are 1) to quantify power flow losses owing to ultrahigh magnetic fields, 2) to model the response of VISAR diagnostic samples in various configurations on Z, and 3) to incorporate the most appropriate equation of state and conductivity models into our magnetohydrodynamics (MHD) computations. Certain features are strongly dependent on the details of the conductivity model     

Coherent production ofρ − mesons in charged current antineutrino-neon interactions in BEBC

Coherent production ofρ ^? mesons in charged current antineutrino interactions on neon nuclei is studied in the BEBC bubble chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25)·10^?40 cm² per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model.     

Evidence for higher twist effects in fast π− production by antineutrinos in neon

Evidence for a significant higher twist contribution to highz π^? production in antineutrino scattering is presented. In events withW>3 GeV andQ ²>1 GeV² in our data, it accounts for (51 ±8)% of all π^? withz above 0.5. It is consistent with thez?Q ² correlations of Berger's higher twist prediction. The data are inconclusive concerning the predictedy?z correlation andp _T dependence. Thez ?Q ² correlation is not adequately described by the Lund Monte-Carlo.