Probe electrode study of cathodically polarized PtIr-YSZ interfaces

Journal of Solid State Electrochemistry - Local cathodic polarizations of yttria-stabilized zirconia were carried out with a PtIr probe as the working electrode in a controlled atmosphere high...     

On the Relation between the Scalar Moment Problem and the Matrix Moment Problem on *-Semigroups

There is a countable cancellative commutative *-semigroup S withzero (in fact, a *-subsemigroup of G × N₀ for some abelian group G carrying the inverse involution) such that the answer to the question “if f is a function on S , with values in M_d(C) (the square matrices of order d) and such that $\sum^{n}_{j,k=1} \lbrak f(s^*_k s_j)\xi_j, \xi_k \rbrak \ge 0$ for all n in N, s₁, . . . , s_n in S , and $\xi_1$, . . . , $\xi_n$ in C^d, does it follow that $f(s) = \int_{S^*}\sigma (s) d\mu(\sigma) (s \memb S)$ for some measure $\mu$ (with values in M_d(C)₊ , the positive semidenite matrices) on the space S of hermitian multiplicative functions on S?” is “yes” if d = 1 but “no” if d = 2 (hence also for d > 2).     

Composition of particles emitted at largep T and medium angles inpp,dd, andαα collisions at the CERN intersecting storage rings

The relative yields of kaons and protons compared with the yield of pions at highp _T and polar angles θ away from 90° (in the range from 10° to 45°) are presented forpp, dd, and αα interactions at a centre-of-mass energy \(\sqrt {s_{NN} } = 31\) GeV per nucleon-nucleon collision. The measured particle ratios depend on the atomic mass numberA of the beam particles and on θ. TheA dependence of the ratios becomes stronger for largerp _T and is more pronounced at smaller polar angles.     

High-p T αα andαp interactions

Properties of secondaries associated with a high-p _T charged trigger particle (3<p _T <5 GeV/c) were studied for αp and αα interactions at c.m. energies \(\sqrt s = 88\) GeV and 125 GeV, respectively. Thep _T distributions of secondaries in the away-jet and trigger-jet regions were compared with those for high-p _{T pp} interactions. No statistically significant differences were seen, except at lowp _T . Momentum and angular distributions of spectator and leading protons were studied as a function of charge and rapidity of the trigger hadron. The observed correlations between trigger charge and number of spectator protons provide evidence of valence quark contributions to the trigger jet.     

Simulation of the electronic and vibrational structure of hydrogenated amorphous silicon using cluster models

A set of simple models of hydrogenated amorphous silicon (a-Si:H) consisting of hypothetical silane molecules with diamond or similar lattices was studied by the semiempirical AM1 method. Densities of states and infrared spectra were calculated for the silane molecules and similar molecules with dangling bonds disorder, and with boron or phosphorus substitution to simulate doping. Some examples are presented, and a comparison is made with experimental properties of a-Si:H. It is proposed to use these models in a study of the Staebler–Wronski photodegradation of a-Si:H and other aspects of amorphous silicon technology. © John Wiley & Sons, Inc.     

Speciation analysis — why and how?

Summary The different aspects of speciation analysis are reviewed. Species-specific instrumental techniques as well as various speciation schemes are considered for the determination of species of metals and metalloids, including organometallic compounds. The application of the methods are discussed in some detail for the analysis of natural waters, air, soil, sediment and biological samples. The relationship between metal species and bioavailability is also briefly dealt with.     

Trace metal analysis by anodic-stripping voltammetry Effect of surface-active substances

The presence of cationic, anionic, and neutral surfactants and humic substances is shown to affect the peak heights of copper, lead and cadmium in synthetic sea-water analysed by differential pulse anodic-stripping voltammetry. At surfactant concentrations below 0.1 mg/l. the effect is insignificant, but at higher concentrations the peak heights usually decrease, although for copper an increase in the peak height was also observed. The peak heights do not depend to any great extent on the pH of the solution, except in alkaline solution and in the presence of humic substances. Adsorption and complex formation may account for the observed dependences.     

Optical constants of HNO3/H2O and H2SO4/HNO3/H2O at low temperatures in the infrared region

The complex index of refraction of liquid HNO3/H2O and H2SO4/HNO3/H2O has been obtained at different temperatures and acid concentrations. FT-IR specular reflectance spectra were obtained for 30, 54, and 64 wt % aqueous HNO3 and for four different H2SO4/HNO3/H2O mixtures in the temperature region from 293 to 183 K. The complex index of refraction was obtained from the reflectance spectra with the Kramers-Kronig transformation. The optical constants of the binary and ternary mixtures vary with the acid concentration and the temperature. The results demonstrate that vibrational bands originating from the sulfate species are more sensitive to changes in temperature than the bands originating from vibrations in the nitrate species; only minor changes in the nitrate vibrational bands are observed as the temperature decreases below 248 K.