Supramolecular chemistry of helical foldamers at the solid-liquid interface: self-assembled monolayers and anion recognition

The synthesis of a redox-active helical foldamer and its immobilization onto a gold electrode are described. These large molecular architectures are grafted in a reproducible manner and provide foldamer-based self-assembled monolayers displaying recognition properties

Low temperature transition to a superconducting phase in boron-doped silicon films grown on (001)-oriented silicon wafers

We report on a detailed analysis of the superconducting properties of boron-doped silicon films grown along the 001 direction by Gas Immersion Laser Doping. The doping concentration cB has been varied up to approx. 10 at.% by increasing the number of laser shots to 500. No superconductivity could be observed down to 40mK for doping level below 2.5 at.%. The critical temperature Tc then increased steeply to reach 0.6K for cB = 8 at%. No hysteresis was found for the transitions in magnetic field, which is characteristic of a type II superconductor. The corresponding upper critical field Hc2(0) was on the order of 1000 G, much smaller than the value previously reported by Bustarret et al. in Nature (London) 444, 465 (2006).Comment: 4 pages including 4 figures, submitted to PRB-Rapid Communicatio

Evidence of electrochemical transduction of cation recognition by TEMPO derivatives

This work reports the first example of electrochemical cation binding transduction via nitroxyl groups. It shows the possibility to transduce a complexation without a pi-conjugated bridge between the redox and the host moieties. As expected, we confirm that the host/redox probe distance is a key point for transduction

Big data in economics: evolution or revolution?

The Big Data Era creates a lot of exciting opportunities for new developments in economics and econometrics. At the same time, however, the analysis of large datasets poses difficult methodological problems that should be addressed appropriately and are the subject of the present chapter

Grids of Stellar Models and Frequencies with CLES + LOSC

We present a grid of stellar models, obtained with the CLES evolution code, following the specification of ESTA-Task1, and the corresponfing seismic properties, computed with the LOSC code. We provide a complete description of the corresponding files that will be available on the ESTA web-pages.Comment: 8 pages, accepted for publication in Astrophys. Space Sci. (CoRoT/ESTA Volume

Status of Superconducting RF Linac Development for APT

This paper describes the development progress of high current superconducting RF linacs in Los Alamos, performed to support a design of the linac for the APT (Accelerator Production of Tritium) Project. The APT linac design includes a CW superconducting RF high energy section, spanning an energy range of 211 to 1030 MeV, and operating at a frequency of 700 MHz with two constant beta sections (beta of 0.64 and 0.82). In the last two years, we have progressed towards build a cryomodule with beta of 0.64. We completed the designs of the 5 cell superconducting cavities and the 210 kW power couplers. We are scheduled to begin assembly of the cryomodule in September 2000. In this paper, we present an overview of the status of our development efforts and a report on the results of the cavity and coupler test program.Comment: LINAC2000 THD1

Comparing Cosmic Microwave Background Datasets

To extract reliable cosmic parameters from cosmic microwave background datasets, it is essential to show that the data are not contaminated by residual non-cosmological signals. We describe general statistical approaches to this problem, with an emphasis on the case in which there are two datasets that can be checked for consistency. A first visual step is the Wiener filter mapping from one set of data onto the pixel basis of another. For more quantitative analyses we develop and apply both Bayesian and frequentist techniques. We define the ``contamination parameter'' and advocate the calculation of its probability distribution as a means of examining the consistency of two datasets. The closely related ``probability enhancement factor'' is shown to be a useful statistic for comparison; it is significantly better than a number of chi-squared quantities we consider. Our methods can be used: internally (between different subsets of a dataset) or externally (between different experiments); for observing regions that completely overlap, partially overlap or overlap not at all; and for observing strategies that differ greatly. We apply the methods to check the consistency (internal and external) of the MSAM92, MSAM94 and Saskatoon Ring datasets. From comparing the two MSAM datasets, we find that the most probable level of contamination is 12%, with no contamination only 1.05 times less probable, and 100% contamination strongly ruled out at over 2 X 10^5 times less probable. From comparing the 1992 MSAM flight with the Saskatoon data we find the most probable level of contamination to be 50%, with no contamination only 1.6 times less probable and 100% contamination 13 times less probable. [Truncated]Comment: LaTeX, 16 pages which include 16 figures, submitted to Phys. Rev.

The deuterium-to-oxygen ratio in the interstellar medium

Because the ionization balances for HI, OI, and DI are locked together by charge exchange, D/O is an important tracer for the value of the D/H ratio and for potential spatial variations in the ratio. As the DI and OI column densities are of similar orders of magnitude for a given sight line, comparisons of the two values will generally be less subject to systematic errors than comparisons of DI and HI, which differ by about five orders of magnitude. Moreover, D/O is additionally sensitive to astration, because as stars destroy deuterium, they should produce oxygen. We report here the results of a survey of D/O in the interstellar medium performed with FUSE. We also compare these results with those for D/N. Together with a few results from previous missions, the sample totals 24 lines of sight. The distances range from a few pc to ~2000 pc and log N(DI) from ~13 to ~16 (cm-2). The D/O ratio is constant in the local interstellar medium out to distances of ~150 pc and N(DI) ~ 1x10^15 cm-2, i.e. within the Local Bubble. In this region of the interstellar space, we find D/O = (3.84+/-0.16)x10^-2 (1 sigma in the mean). The homogeneity of the local D/O measurements shows that the spatial variations in the local D/H and O/H must be extremely small, if any. A comparison of the Local Bubble mean value with the few D/O measurements available for low metallicity quasar sight lines shows that the D/O ratio decreases with cosmic evolution, as expected. Beyond the Local Bubble we detected significant spatial variations in the value of D/O. This likely implies a variation in D/H, as O/H is known to not vary significantly over the distances covered in this study. Our dataset suggests a present-epoch deuterium abundance below 1x10^-5, i.e. lower than the value usually assumed, around 1.5x10^-5.Comment: 17 pages, 9 figures, 4 tables, accepted for publication in the Astrophysical Journa