Dynamics of the Marginal Late Wisconsin Miami Sublobe, Cincinnati, Ohio

Author Institution: Department of Geology, University of CincinnatiPhysical characteristics and stratigraphic relationships of glacigenic diamictons in southwestern Ohio have permitted interpretation of local activity and thermal regime of the ice margin beginning at about 19,700 yr BP. At the Sharonville site near Cincinnati, pre-late Wisconsin sediments are overlain by four late Wisconsin lithofacies (three diamictons, one sand and gravel). At the base of the sequence, pre-late Wisconsin sediments are incorporated as blocks and lenses in the overlying diamictons, indicating erosion and entrainment, probably by freezing onto the glacier base. Facies 1 contains sand-filled shear planes and smudges of underlying sediments; the diamicton is interpreted to be a deformation till, which indicates a change in basal thermal regime to overall melting. Facies 2 contains blocks of clay, silt, and sorted sand and gravel, and is interpreted to be a subglacial meltout till, which represents deposition from melting, but stagnant, ice. Facies 3 is massive, with variable clast fabrics, and is interpreted to be a sediment flow deposit, reflecting continued marginal melting and recession. The uppermost facies is comprised of poorly sorted sand and gravel, and is interpreted to represent fluvial deposition. Portions of this sequence are stacked at the southern end of the site, and indicate ice-marginal deformation associated with a reactivation of ice with a freezing basal regime in the study area. This sequence indicates at least two periods of active late Wisconsin ice at Sharonville, and a number of fluctuations in basal thermal regime

Vulnerabilities in first-generation RFID-enabled credit cards

Credit cards ; Radio frequency identification systems

Statistical variable selection: an alternative prioritization strategy during the nontarget analysis of LC-HR-MS data

Liquid chromatography coupled to high resolution mass spectrometry (LC-HR-MS) has been one of the main analytical tools for the analysis of small polar organic pollutants in the environment. LC-HR-MS typically produces a large amount of data for a single chromatogram. The analyst is therefore required to perform prioritization prior to nontarget structural elucidation. In the present study, we have combined the F-ratio statistical variable selection and the apex detection algorithms in order to perform prioritization in data sets produced via LC-HR-MS. The approach was validated through the use of semisynthetic data, which was a combination of real environmental data and the artificially added signal of 31 alkanes in that sample. We evaluated the performance of this method as a function of four false detection probabilities, namely: 0.01, 0.02, 0.05, and 0.1%. We generated 100 different semisynthetic data sets for each F-ratio and evaluated that data set using this method. This design of experiment created a population of 30 000 true positives and 32 000 true negatives for each F-ratio, which was considered sufficiently large enough in order to fully validate this method for analysis of LC-HR-MS data. The effect of both the F-ratio and signal-to-noise ratio (S/N) on the performance of the suggested approach were evaluated through normalized statistical tests. We also compared this method to the pixel-by-pixel as well as peak list approaches. More than 92% of features present in the final feature list via the F-ratio method were also present in the conventional peak list generated by MZmine. However, this method was the only approach successful in the classification of samples, and thus prioritization, when compared to the other evaluated approaches. The application potential and limitations of the suggested method are discussed.acceptedVersio

Chemical Stabilization of Perovskite Solar Cells with Functional Fulleropyrrolidines.

While perovskite solar cells have invigorated the photovoltaic research community due to their excellent power conversion efficiencies (PCEs), these devices notably suffer from poor stability. To address this crucial issue, a solution-processable organic chemical inhibition layer (OCIL) was integrated into perovskite solar cells, resulting in improved device stability and a maximum PCE of 16.3%. Photoenhanced self-doping of the fulleropyrrolidine mixture in the interlayers afforded devices that were advantageously insensitive to OCIL thickness, ranging from 4 to 190 nm. X-ray photoelectron spectroscopy (XPS) indicated that the fulleropyrrolidine mixture improved device stability by stabilizing the metal electrode and trapping ionic defects (i.e., I-) that originate from the perovskite active layer. Moreover, degraded devices were rejuvenated by repeatedly peeling away and replacing the OCIL/Ag electrode, and this repeel and replace process resulted in further improvement to device stability with minimal variation of device efficiency

Quantum non-demolition measurements of single donor spins in semiconductors

We propose a technique for measuring the state of a single donor electron spin using a field-effect transistor induced two-dimensional electron gas and electrically detected magnetic resonance techniques. The scheme is facilitated by hyperfine coupling to the donor nucleus. We analyze the potential sensitivity and outline experimental requirements. Our measurement provides a single-shot, projective, and quantum non-demolition measurement of an electron-encoded qubit state.Comment: 8+ pages. 4 figures. Published versio