Baryonic acoustic oscillations simulations for the Large Synoptic Survey Telescope (LSST)

The baryonic acoustic oscillations are features in the spatial distribution of the galaxies which, if observed at different epochs, probe the nature of the dark energy. In order to be able to measure the parameters of the dark energy equation of state to high precision, a huge sample of galaxies has to be used. The Large Synoptic Survey Telescope will survey the optical sky with 6 filters from 300nm and 1100nm, such that a catalog of galaxies with photometric redshifts will be available for dark energy studies. In this article, we will give a rough estimate of the impact of the photometric redshift uncertainties on the computation of the dark energy parameter through the reconstruction of the BAO scale from a simulated photometric catalog.Comment: 4 pages, 2 figures, 10th Rencontres de Blois proceedin

Research on electric heating of metals for thermal treatment Final report

Electric heat treatment process for aluminum and titanium aluminum vanadium alloy

The Sloan Lens ACS Survey. VIII. The relation between environment and internal structure of early-type galaxies

We study the relation between the internal structure of early-type galaxies and their environment using 70 strong gravitational lenses from the Sloan ACS Lens Survey. The Sloan database is used to determine two measures of overdensity of galaxies around each lens: the projected number density of galaxies inside the tenth nearest neighbor (\Sigma_{10}) and within a cone of radius one h^{-1} Mpc (D_1). Our main results are: 1) The average overdensity is somewhat larger than unity, consistent with lenses preferring overdense environments as expected for massive early-type galaxies (12/70 lenses are in known groups/clusters). 2) The distribution of overdensities is indistinguishable from that of "twin" non-lens galaxies selected from SDSS to have the same redshift and stellar velocity dispersion \sigma_*. Thus, within our errors, lens galaxies are an unbiased population, and the SLACS results can be generalized to the overall population of early-type galaxies. 3) Typical contributions from external mass distribution are no more than a few per cent, reaching 10-20% (~0.05-0.10 external convergence) only in the most extreme overdensities. 4) No significant correlation between overdensity and slope of the mass density profile of the lens is found. 5) Satellite galaxies (those with a more luminous companion) have marginally steeper mass density profiles than central galaxies (those without). This result suggests that tidal stripping may affect the mass structure of early-type galaxies down to kpc scales probed by strong lensing, when they fall into larger structures [ABRIDGED].Comment: ApJ, in press; minor changes with respect to v

CO2 storage risk minimization through systematic identification and assessment of faults: a Williston Basin case study

AbstractThe Williston Basin is considered a tectonically stable area with only a few major inactive faults. Over the last 50 years, extensive hydrocarbon exploration in the basin has demonstrated that smaller faults do exist and closer evaluation is necessary to determine the nature of this faulting. An area near the town of Dickinson, North Dakota, has been identified as a potential location for CO2 storage/enhanced oil recovery. A thorough geologic assessment of the area has identified structural anomalies that may indicate the presence of faulting, which, in turn, may affect precise CO2 storage site selection

On designing observers for time-delay systems with nonlinear disturbances

This is the post print version of the article. The official published version can be obtained from the link below - Copyright 2002 Taylor & Francis LtdIn this paper, the observer design problem is studied for a class of time-delay nonlinear systems. The system under consideration is subject to delayed state and non-linear disturbances. The time-delay is allowed to be time-varying, and the non-linearities are assumed to satisfy global Lipschitz conditions. The problem addressed is the design of state observers such that, for the admissible time-delay as well as non-linear disturbances, the dynamics of the observation error is globally exponentially stable. An effective algebraic matrix inequality approach is developed to solve the non-linear observer design problem. Specifically, some conditions for the existence of the desired observers are derived, and an explicit expression of desired observers is given in terms of some free parameters. A simulation example is included to illustrate the practical applicability of the proposed theory.The work of Z. Wang was supported in part by the University of Kaiserslautern of Germany and the Alexander von Humboldt Foundation of Germany

Design and Implementation of a Scalable, Automated, Semi-Permanent Seismic Array for Detecting CO2 Extent during Geologic CO2 Injection

A proof-of-concept demonstration using a scalable, automated, semipermanent, seismic array (SASSA) is being conducted to test a novel seismic method for detecting and tracking an injected CO2plume as it traverses discreet points within a reservoir in southeastern Montana at Bell Creek oil field which is undergoing commercial CO2enhanced oil recovery (EOR). This document serves to describe the technical design of the project infrastructure, the operational approach, corresponding data collection, and data-processing activities

Thermal switch of oscillation frequency in belousov- zhabotinsky liquid marbles

© 2019 The Authors. External control of oscillation dynamics in the Belousov- Zhabotinsky (BZ) reaction is important for many applications including encoding computing schemes. When considering the BZ reaction, there are limited studies dealing with thermal cycling, particularly cooling, for external control. Recently, liquid marbles (LMs) have been demonstrated as a means of confining the BZ reaction in a system containing a solid-liquid interface. BZ LMs were prepared by rolling 50 ml droplets in polyethylene (PE) powder. Oscillations of electrical potential differences within the marble were recorded by inserting a pair of electrodes through the LM powder coating into the BZ solution core. Electrical potential differences of up to 100mV were observed with an average period of oscillation ca 44 s. BZ LMs were subsequently frozen to 218C to observe changes in the frequency of electrical potential oscillations. The frequency of oscillations reduced upon freezing to 11mHz cf. 23 mHz at ambient temperature. The oscillation frequency of the frozen BZ LM returned to 23 mHz upon warming to ambient temperature. Several cycles of frequency fluctuations were able to be achieved

Hydrogen atom in a spherical well: linear approximation

We discuss the boundary effects on a quantum system by examining the problem of a hydrogen atom in a spherical well. By using an approximation method which is linear in energy we calculate the boundary corrections to the ground-state energy and wave function. We obtain the asymptotic dependence of the ground-state energy on the radius of the well.Comment: Revised version to appear in European Journal of Physic

Low cost production of computer-generated holograms: from design to optical evaluation

In this work we review some optical characterization methods useful for the low cost production of two phase level computer generated holograms (CGH). As an example, binary CGH are designed with an iterative Fourier transform algorithm (IFTA) and fabricated on a silicon master micromachining with a single step of selective dry etch of silicon dioxide (SiO2) layer. The CGH characterization is performed in three steps; a first one involves the application of spectroscopic ellipsometry measurements to accurately measure the thickness of the SiO2 layer. These results permit the evaluation of the relative complex reflectance between the two levels of the developed hologram as a function of the wavelength. In a second step, interference microscopy is applied to directly visualize the phase shift in the SiO2/Si binary phase profile. Finally, the performance and diffraction efficiency of the fabricated CGH is compared for various lasers with different wavelengths. These experimental measurements in these two last steps confirm with very good accuracy the results derived from the spectroscopic ellipsometry analysis. In conjunction, the combination of these well established optical techniques provides a precise optical characterization of binary diffractive optical elements produced with simple and low cost technique, useful for mass production