Realization of an Inductance Scale Traceable to the Quantum Hall Effect Using an Automated Synchronous Sampling System

In this paper, the realization of an inductance scale from 1~$\mu$H to 10~H for frequencies ranging between 50~Hz to 20~kHz is presented. The scale is realized directly from a series of resistance standards using a fully automated synchronous sampling system. A careful systematic characterization of the system shows that the lowest uncertainties, around 12~$\mu$H/H, are obtained for inductances in the range from 10~mH to 100~mH at frequencies in the kHz range. This new measurement system which was successfully evaluated during an international comparison, provides a primary realization of the henry, directly traceable to the quantum Hall effect. An additional key feature of this system is its versatility. In addition to resistance-inductance (R-L) comparison, any kind of impedances can be compared: R-R, R-C, L-L or C-C, giving this sampling system a great potential of use in many laboratories around the world

Epitaxial growth of Cu on Cu(001): experiments and simulations

A quantitative comparison between experimental and Monte Carlo simulation results for the epitaxial growth of Cu/Cu(001) in the submonolayer regime is presented. The simulations take into account a complete set of hopping processes whose activation energies are derived from semi-empirical calculations using the embedded-atom method. The island separation is measured as a function of the incoming flux and the temperature. A good quantitative agreement between the experiment and simulation is found for the island separation, the activation energies for the dominant processes, and the exponents that characterize the growth. The simulation results are then analyzed at lower coverages, which are not accessible experimentally, providing good agreement with theoretical predictions as well.Comment: Latex document. 7 pages. 3 embedded figures in separate PS files. One bbl fil

Microwave Spectroscopy

Contains reports on four research projects

Study of Earthquake Recurrence Intervals on the Wasatch Fault, Utah: Little Cottonwood Canyon Site

Detailed geologic mapping, topographic profiling, and trenching are being conducted at selected sites along the Wasatch fault zone to measure the cumulative fault displacements in Quaternary strata of various ages and to obtain data regarding the amount of displacement per surface faulting event and the number and recurrence of faulting events that produced the cumulative displacement. These data are used to estimate the frequency of occurrence and magnitude of earthquakes associated with surface faulting along individual segments of the Wasatch fault zone. Investigations have been completed at three sites, the Kaysville, Hobble Creek, and Little Cottonwood Canyon sites. The results of the investigations at the Kaysville and Hobble Creek sites are discussion in our previous reports, which are listed in Appendix A. Detailed geologic investigations were conducted at the Little Cottonwood Canyon site during June, July, and October, 1979. This report presents our findings, interpretations, and preliminary conclusions based on our field investigations at the Little Cottonwood Canyon site

Morita Equivalence, Picard Groupoids and Noncommutative Field Theories

In this article we review recent developments on Morita equivalence of star products and their Picard groups. We point out the relations between noncommutative field theories and deformed vector bundles which give the Morita equivalence bimodules.Comment: Latex2e, 10 pages. Conference Proceeding for the Sendai Meeting 2002. Some typos fixe

French vocabulary in Encore Tricolore: do pupils have a chance?

British learners acquire very little vocabulary in their foreign languages,compared to pupils elsewhere in Europe, particularly learners of English as aforeign language. Could the materials used for teaching help explain thisdifference? An analysis of the vocabulary loading of a textbook for French as aforeign language commonly used in Britain, Encore Tricolore (Mascie-Taylor andHonnor, 2001, Cheltenham, UK, Nelson Thornes), was carried out with thisquestion in mind. An analysis of the vocabulary suggests that it is not introducedand practised in a way that is conducive to building a sufficiently large vocabularyto reach level B1 of the Common European Framework of Reference forLanguages (CEFR)

The Dark Side of ROTSE-III Prompt GRB Observations

We present several cases of optical observations during gamma-ray bursts (GRBs) which resulted in prompt limits but no detection of optical emission. These limits constrain the prompt optical flux densities and the optical brightness relative to the gamma-ray emission. The derived constraints fall within the range of properties observed in GRBs with prompt optical detections, though at the faint end of optical/gamma flux ratios. The presently accessible prompt optical limits do not require a different set of intrinsic or environmental GRB properties, relative to the events with prompt optical detections.Comment: ApJ accepted. 20 pages in draft manuscript form, which includes 6 pages of tables and 2 figure

The Neron-Severi group of a proper seminormal complex variety

We prove a Lefschetz (1,1)-Theorem for proper seminormal varieties over the complex numbers. The proof is a non-trivial geometric argument applied to the isogeny class of the Lefschetz 1-motive associated to the mixed Hodge structure on H^2.Comment: 16 pages; Mathematische Zeitschrift (2008