Thirteen-color narrow-band photometry of one thousand bright stars

Thirteen-color narrow-band photometry of one thousand bright star

A survey of thermodynamic properties of the compounds of the elements CHNOPS Eighth progress report, 1 Apr. - 30 Jun. 1966

Thermodynamic properties of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur compound

Cl electrosorption on Ag(100): Lateral interactions and electrosorption valency from comparison of Monte Carlo simulations with chronocoulometry experiments

We present Monte Carlo Simulations using an equilibrium lattice-gas model for the electrosorption of Cl on Ag(100) single-crystal surfaces. Fitting the simulated isotherms to chronocoulometry experiments, we extract parameters such as the electrosorption valency gamma and the next-nearest-neighbor lateral interaction energy phi_nnn. Both coverage-dependent and coverage independent gamma were previously studied assuming a constant phi_nnn [I. Abou Hamad, Th. Wandlowski, G. Brown, P.A. Rikvold, J. Electroanal. Chem. 554-555 (2003) 211]. Here, a self-consistent, entirely electrostatic picture of the lateral interactions with a coverage-dependent phi_nnn is developed, and a relationship between phi_nnn and gamma is investigated for Cl on Ag(100).Comment: Accepted for publication in Electrochimica Acta, 10 pages, 7 figures, 2 tables and an appendi

Cervical cytology reported as negative and risk of adenocarcinoma of the cervix: no strong evidence of benefit.

The relationship between negative cervical cytology reports and risk of adenocarcinoma of the cervix was evaluated in a case-control study of 113 cases and 452 controls. All cases and controls had received at least two negative cytology reports. There was no significant difference between the cases and controls in the number of negative cytology reports or in history of cervical abnormality; while a test for trend in the time since last negative cytology report was significant (P < 0.001), the estimated benefit was very modest. Although the estimates of relative protection were higher in women aged less than 35 years than in women aged 35-69 years, this difference was not statistically significant. These results suggest that cervical screening as practised in the 1970s and 1980s was much less effective in preventing adenocarcinoma than squamous carcinoma of the cervix

Determination of the basic timescale in kinetic Monte Carlo simulations by comparison with cyclic-voltammetry experiments

While kinetic Monte Carlo simulations can provide long-time simulations of the dynamics of physical and chemical systems, it is not yet possible in general to identify the inverse Monte Carlo attempt frequency with a physical timescale. Here we demonstrate such an identification by comparing simulations with experimental data. Using a dynamic lattice-gas model for the electrosorption of Br on Ag(100), we measure the scan-rate dependence of the separation between positive-and negative-going peaks in cyclic-voltammetry (CV) and compare simulated and experimental peak separations. By adjusting the Monte Carlo attempt frequency, good agreement between simulated and experimental peak separations is achieved. It is also found that the uniqueness of such a determination is dependent on the relative values of the adsorption/desorption and diffusion free-energy barriers.Comment: Accepted for publication in Surface Science Letters,8 pages, 4 figure

Nematic-Isotropic Transition with Quenched Disorder

Nematic elastomers do not show the discontinuous, first-order, phase transition that the Landau-De Gennes mean field theory predicts for a quadrupolar ordering in 3D. We attribute this behavior to the presence of network crosslinks, which act as sources of quenched orientational disorder. We show that the addition of weak random anisotropy results in a singular renormalization of the Landau-De Gennes expression, adding an energy term proportional to the inverse quartic power of order parameter Q. This reduces the first-order discontinuity in Q. For sufficiently high disorder strength the jump disappears altogether and the phase transition becomes continuous, in some ways resembling the supercritical transitions in external field.Comment: 12 pages, 4 figures, to be published on PR

Simple proof of equivalence between adiabatic quantum computation and the circuit model

We prove the equivalence between adiabatic quantum computation and quantum computation in the circuit model. An explicit adiabatic computation procedure is given that generates a ground state from which the answer can be extracted. The amount of time needed is evaluated by computing the gap. We show that the procedure is computationally efficient.Comment: 5 pages, 2 figures. v2: improved gap estimates and added some more detail

Deconstruct and preserve (DaP): a method for the preservation of digital evidence on solid state drives (SSD)

Imaging SSDs is problematic due to TRIM commands and garbage collectors that make the SSD behave inconsistently over time. It is this inconsistency that can cause a difference between images taken of the SSD. These differences result in unmatched hash number gener-ation and would normally be attributed to contamination or spoliation of digital evidence. DaP is a proposed method that ensures all images taken of the SSD are consistent and removes the volatility normally as-sociated with these devices. DaP is not focused with the recoverability of deleted data, however DaP does stabilise the device to prevent uninten-tional contamination due to garbage collection. Experiments show that the DaP method works on a range of devices and consistently produces the hash-identical images. The conclusions are to consider DaP as a new Standard Operating Procedure (SOP) when imaging SSDs

First-order Raman spectra of double perovskites AB′1/2B'{1/2}B''{1/2}O3

First principles computations of Raman intensities were performed for perovskite-family compound CaAl$_{1/2}$Nb$_{1/2}$O$_3$ (CAN). This compound features 1:1 (NaCl-type) ordering of Al and Nb superimposed onto the $b^-b^-c+$ octahedral tilting. Raman tensor for CAN was computed using the package for first-principles computations ABINIT (URL \underline {http://www.abinit.org}). Computations performed for both untilted cubic ($Fm\bar{3}m$) and tilted monoclinic ($P2_1/n$) CAN structures showed that the strongest Raman lines are associated with the ordering of Al and Nb. The computed spectrum agreed qualitatively with the experimental data measured on powder (CAN is available in polycrystalline form only). The effect of cation disorder on the Raman intensities was considered using phenomenological theory of light scattering in the vicinity of a phase transition. We suggest that, for certain modes, the corresponding Raman intensities depend primarily on the average long range order while, for other modes, the intensities are determined by fluctuations of the order parameter.Comment: 4 figures, submitte

Energy Harvesting for the Internet-of-Things: Measurements and Probability Models

The success of future Internet-of-Things (IoT) based application deployments depends on the ability of wireless sensor platforms to sustain uninterrupted operation based on environmental energy harvesting. In this paper, we deploy a multitransducer platform for photovoltaic and piezoelectric energy harvesting and collect raw data about the harvested power in commonly-encountered outdoor and indoor scenarios. We couple the generated power profiles with probability mixture models and make our data and processing code freely available to the research community for wireless sensors and IoT-oriented applications. Our aim is to provide data-driven probability models that characterize the energy production process, which will substantially facilitate the coupling of energy harvesting statistics with energy consumption models for processing and transceiver designs within upcoming IoT deployments