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

An overview of the IEA greenhouse gas R&D programme regional geologic storage capacity studies

AbstractMapping of CO2 geological storage resources provides an important element in the planning of widespread CO2 capture and storage (CCS) deployment. Recent high-level studies by the IEA Greenhouse Gas R&D Programme (IEAGHG) have estimated realistic global capacity available in depleted oil and depleted gas fields to be 130 and 65 Gt, respectively, based on mass balance considerations from hydrocarbon reserve information. However, comparable estimates for deep saline formation (DSF) storage require an analytical approach that considers the fraction of pore space in storage formations that could be occupied by injected CO2. Many regional mapping initiatives have shown that potential DSF storage capacities are typically at least an order of magnitude higher than in depleted fields.Computationally similar methodologies to estimate DSF storage resources have been developed by the U.S. Department of Energy (DOE) and the Carbon Sequestration Leadership Forum (CSLF); in both, a storage coefficient, E (or efficiency factor), is used to derive resource estimates. The E coefficient takes account of various geological and technical factors that could restrict the amount of pore space available for storage but does not take into account economic, regulatory, and source-sink matching considerations.IEAGHG and DOE commissioned a study in 2008 by the Energy & Environmental Research Center (EERC), to improve the accuracy of storage coefficients for DSF. As there was insufficient real-world CO2 injection data to derive a representative range for E, geological input parameters were derived from global hydrocarbon reservoir data as a proxy for DSF. Modeling allowed derivation of probabilistic ranges of storage coefficients at both site-specific and formation levels for clastic, carbonate, and dolomite lithologies. The overall mean value of E for all lithologies was calculated as 2.6% at the formation level. A key assumption made in the study was that DSF will predominantly act as “open” systems, whereby pressure and displaced formation fluids can be safely dissipated through the wider storage formation and adjacent strata

A hybrid camphor-camphene wax material for studies on self-propelled motion.

A new material that combines self-propelled motion with wax-like mechanical properties and can be formed into non-trivial shapes is presented

Prediction of two-phase thermosyphon throughput by self developed cae program

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Computer Aided Engineering (CAE) program for prediction of two-phase closed thermosyphon throughput is developed. Thermosyphon working fluids under consideration are modern refrigerants (R404A, R407C, R134A etc.). Program is cross-platform - written in Java language. Solution process of temperatures and heat flux is done by iterative scheme. It is also a tool facilitating experimental process - automating documentation of measurements and providing fast validation. Throughput and mean temperatures computed are compared with experimental data. Empirical coefficients are matched expressing influence of different filling volumes (ratios) on heat transfer. Various modes of heat transfer are included for cooling and heating of condenser/evaporator section.cf201

Fluorescence spectroscopy for characterization and differentiation of beers

Total luminescence and synchronous scanning fluorescence spectroscopic techniques were applied for characterization of the intrinsic fluorescence of eight different beers. Spectra were measured using different geometries to reveal the presence of similar fluorescent components. The total luminescence and synchronous fluorescence spectra exhibit a relatively intense short-wavelength emission ascribed to aromatic amino acids and less intense emission in the long-wavelength region, which may originate from B vitamins. Classification of beers based on their synchronous fluorescence spectra was performed using non-parametrical k nearest neighbours method and linear discriminant analysis. Very good discrimination was obtained in both methods with a low classification error. The results demonstrate the potential of fluorescence techniques to characterize and differentiate beers

AC Stark-shift in CPT-based Cs miniature atomic clocks

We report on studies on the light-shift in caesium miniature atomic clocks based on coherent population trapping (CPT) using a micro-fabricated buffer-gas cell (MEMS cell). The CPT signal is observed on the Cs D1-line by coupling the two hyperfine ground-state Zeeman sublevels involved in the clock transition to a common excited state, using two coherent electromagnetic fields. These light fields are created with a distributed feedback laser and an electro-optical modulator. We study the light-shift phenomena at different cell temperatures and laser wavelengths around 894.6nm. By adjusting the cell temperature, conditions are identified where a miniature CPT atomic clock can be operated with simultaneously low temperature coefficient and suppressed light-shift. The impact of the light-shift on the clock frequency stability is evaluated. These results are relevant for improving the long-term frequency stability of CPT-based Cs vapour-cell clock

Unique Aggregation of Sterigmatocystin in Water Yields Strong and Specific Circular Dichroism Response Allowing Highly Sensitive and Selective Monitoring of Bio-Relevant Interactions

We demonstrated the hitherto unknown property of the mycotoxin sterigmatocystin (STC) to provide homogeneous solutions in aqueous medium by forming a unique aggregate type (not formed by analogous aflatoxins), characterized by exceptionally strong circular dichroism (CD) bands in the 300-400 nm range. Results showed that these CD bands do not originate from intrinsic STC chirality but are a specific property of a peculiar aggregation process similar to psi-DNA CD response. Transmission electron microscopy (TEM) experiments revealed a fine fiber network resembling a supramolecular gel structure with helical fibers. Thermodynamic studies of aggregates by differential scanning calorimetry (DSC) revealed high reversibility of the dominant aggregation process. We demonstrated that the novel STC psi-CD band at 345 nm could be applied at biorelevant conditions (100 nanomolar concentration) and even in marine-salt content conditions for specific and quantitative monitoring of STC. Also, we showed that STC strongly non-covalently interacts with ds-DNA with likely toxic effects, thus contrary to the previous belief requiring prior enzyme epoxidation

Quadratic dependence on temperature of Cs 0-0 hyperfine resonance frequency in single Ne buffer gas microfabricated vapour cell

Presented is the observation of a quadratic temperature dependence of the Cs 0-0 ground state hyperfine resonance frequency in a single Neon (Ne) buffer gas vapour microcell. The inversion temperature, expected to be theoretically independent of the buffer gas pressure, is measured to be about 80-C for two different samples. A proposal to develop chip scale atomic clocks with improved long-term frequency stability, simpler configuration (a single buffer gas instead of a buffer gas mixture) and then relaxed constraints on pressure accuracy during the cell filling procedure is presented

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