Measurement of Three Transport Coefficients and the Thermodynamic Factor in Block Copolymer Electrolytes with Different Morphologies.

The design and engineering of composite materials is one strategy to satisfy the materials needs of systems with multiple orthogonal property requirements. In the case of rechargeable batteries with lithium metal anodes, the system requires a separator with fast lithium ion transport and good mechanical strength. In this work, we focus on the system polystyrene-block-poly(ethylene oxide) (SEO) with bis(trifluoromethane)sulfonimide lithium salt (LiTFSI). Ion transport occurs in the salt-containing poly(ethylene oxide)-rich domains. Mechanical rigidity arises due to the glassy nature of polystyrene (PS). If we assume that the salt does not interact with the PS-rich domains, we can describe ion transport in the electrolyte by three transport parameters (ionic conductivity, κ, salt diffusion coefficient, D, and cation transference number, t+0) and a thermodynamic factor, Tf. By systematically varying the volume fraction of the conducting phase, ϕc between 0.29 and 1.0, and chain length, N between 80 and 8000, we elucidate the role of morphology on ion transport. We find that κ is the strongest function of morphology, varying by three full orders of magnitude, while D is a weaker function of morphology. To calculate t+0 and Tf, we measure the current fraction, ρ+, and the open circuit potential, U, of concentration cells. We find that ρ+ and U follow universal trends as a function of salt concentration, regardless of chain length, morphology, or ϕc, allowing us to calculate t+0 for any SEO/LiTFSI or PEO/LiTFSI mixture when κ and D are known. The framework developed in this paper enables predicting the performance of any block copolymer electrolyte in a rechargeable battery

Passado, presente e futuro da governação educativa na Região Autónoma da Madeira

La consagración, en la Constitución Portuguesa, de las Comunidades Autónomas y su desarrollo en términos competenciales vino a señalar, en el campo de la administración educativa, una ruptura ideológica, tal vez cultural, con la tradición centralista del Estado. Por otra parte, se puede decir que esta realidad ha traído a la dimensión organizativa del Estado, en su conjunto, analizada por un prisma de gobierno de la Educación, también la voluntad y intención de una redistribución del poder entre el centro y la periferia, teniendo como objetivo final salvaguardar el respeto por la diversidad y la proximidad de las políticas educativas que aluden a las realidades locales y a la idiosincrasia de las comunidades escolares. La Comunidad Autónoma de Madeira ha venido, desde los albores de la regionalización en la educación/enseñanza, a ‘debujar’, paso a paso, la construcción gradual de un modelo regional, inicialmente de sustitución y después de creación, cuya evolución, después de su consagración, ahora hay que esperar a ver la intención a darle por los responsables políticos y en qué sentido podemos esperar de ella en el futuro

Unwind: Interactive Fish Straightening

The ScanAllFish project is a large-scale effort to scan all the world's 33,100 known species of fishes. It has already generated thousands of volumetric CT scans of fish species which are available on open access platforms such as the Open Science Framework. To achieve a scanning rate required for a project of this magnitude, many specimens are grouped together into a single tube and scanned all at once. The resulting data contain many fish which are often bent and twisted to fit into the scanner. Our system, Unwind, is a novel interactive visualization and processing tool which extracts, unbends, and untwists volumetric images of fish with minimal user interaction. Our approach enables scientists to interactively unwarp these volumes to remove the undesired torque and bending using a piecewise-linear skeleton extracted by averaging isosurfaces of a harmonic function connecting the head and tail of each fish. The result is a volumetric dataset of a individual, straight fish in a canonical pose defined by the marine biologist expert user. We have developed Unwind in collaboration with a team of marine biologists: Our system has been deployed in their labs, and is presently being used for dataset construction, biomechanical analysis, and the generation of figures for scientific publication

Diagnosing the accretion flow in ultraluminous X-ray sources using soft X-ray atomic features

The lack of unambiguous detections of atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) has proven a hindrance in diagnosing the nature of the accretion flow. The possible association of spectral residuals at soft energies with atomic features seen in absorption and/or emission and potentially broadened by velocity dispersion could therefore hold the key to understanding much about these enigmatic sources. Here we show for the first time that such residuals are seen in several sources and appear extremely similar in shape, implying a common origin. Via simple arguments we assert that emission from extreme colliding winds, absorption in a shell of material associated with the ULX nebula and thermal plasma emission associated with star formation are all highly unlikely to provide an origin. Whilst CCD spectra lack the energy resolution necessary to directly determine the nature of the features (i.e. formed of a complex of narrow lines or intrinsically broad lines), studying the evolution of the residuals with underlying spectral shape allows for an important, indirect test for their origin. The ULX NGC 1313 X-1 provides the best opportunity to perform such a test due to the dynamic range in spectral hardness provided by archival observations. We show through highly simplified spectral modelling that the strength of the features (in either absorption or emission) appears to anticorrelate with spectral hardness, which would rule out an origin via reflection of a primary continuum and instead supports a picture of atomic transitions in a wind or nearby material associated with such an outflow

Surface tension of the isotropic-nematic interface

We present the first calculations of the pressure tensor profile in the vicinity of the planar interface between isotropic liquid and nematic liquid crystal, using Onsager's density functional theory and computer simulation. When the liquid crystal director is aligned parallel to the interface, the situation of lowest free energy, there is a large tension on the nematic side of the interface and a small compressive region on the isotropic side. By contrast, for perpendicular alignment, the tension is on the isotropic side. There is excellent agreement between theory and simulation both in the forms of the pressure tensor profiles, and the values of the surface tension.Comment: Minor changes; to appear in Phys. Rev.

A Review of Kentucky’s Extended-Weight Hauling Programs

Kentucky established its Extended Weight Coal or Coal By-products Haul Road System (EWCHRS) to increase the state’s competitiveness within the coal industry and reduce financial burdens on coal haulers. A new extended-weight haul system for unrefined petroleum products will come online in 2022. To facilitate enforcement of weight limits throughout Kentucky, this report surveys literature on how overweight vehicles affect roads and bridges, describes statutes and regulations governing weight limits in the state, discusses policies and strategies used throughout the US to handle overweight vehicles, and makes recommendations for improving extended-weight policies in Kentucky. It is apparent that pavements and bridges repeatedly exposed to overweight vehicles have shorter life-cycles, but methods for quantifying deterioration rates are lacking. In both Kentucky and throughout the US, agency personnel find that not enough revenues are collected from permitting fees to offset damage caused by overweight trucks. The enforcement landscape is made complex by exemptions that apply to specific industries and commodities. Without adequate staffing and weigh station operations, robust enforcement of weight limits is very challenging. Some of the recommendations for Kentucky to improve its extended-weight policies include studying the feasibility of a statewide long-haul network that accommodates all commodities, modifying the EWCHRS fee structure to generate enough funds to repair damage inflicted by overweight vehicles, strengthen enforcement of weight limits on the EWCHRS, mandate installation of GPS systems on vehicles that travel the EWCHRS to streamline mileage reporting and improve driver awareness of prohibited routes, and eliminate inconsistencies, ambiguities, and redundancies in regulatory and statutory language

Differential antibacterial activities of fusiform and oval morphotypes of phaeodactylum tricornutum (bacillariophyceae)

The diatom, Phaeodactylum tricornutum is a common inhabitant of inshore waters and can exist in different morphotypes that are thought to be adapted for survival in different habitats. Despite this diatom being widely used for physiological and genetic studies of microalgae, little is known about biochemical or physiological differences between the cell morphotypes. The present study was aimed at comparing differences in the antibacterial properties of the fusiform and oval morphotypes, the dominant cell types found in laboratory cultures of most strains of P. tricornutum. In cultures differing in proportions of fusiform and oval cells, there is a significant and positive correlation between the proportion of cells in the fusiform morphotype and the antibacterial activity of cell extracts. Extracts prepared from cultures enriched for fusiform cells (~76%) show greater antibacterial activity against the Gram-positive bacterium, Staphylococcus aureus, than those prepared from pure (100%) oval cultures. Thus fusiform cells contain greater antibacterial activity per cell compared to the ovals. Gas–liquid chromatographic analyses of the extracts reveal that those from enriched fusiform populations contain significantly greater levels of the free fatty acids, eicosapentaenoic acid (EPA), hexadecatrienoic acid (HTA) and palmitoleic acid (PA) than the pure oval cell cultures. These free fatty acids from P. tricornutum have been previously shown by us to have potent antibacterial activity against S. aureus. Free fatty acids, released from damaged microalgal cells, defend the microalgal population against grazing predators but, here, we suggest that these free fatty acids could also act against pathogenic bacteria in the vicinity of the algae. As cell extracts from the fusiform cells contain greater quantities of these fatty acids, fusiform cells may have greater potential than the ovals for this type of protection

An evaluation of heart rate variability in female youth soccer players following soccer heading: A pilot study

Most head impacts in soccer occur from purposeful heading; however, the link between heading and neurological impairment is unknown. Previous work suggests concussion may result in an uncoupling between the autonomic nervous system and cardiovascular system. Accordingly, heart rate variability (HRV) may be a sensitive measure to provide meaningful information regarding repetitive heading in soccer. The purpose of this pilot study assesses the feasibility of measuring HRV to evaluate autonomic function following soccer heading. Sixteen youth female participants underwent heart rate monitoring during a heading and footing condition. Participants completed a five minute resting supine trial at the start and end of each testing session. Standard 450 g soccer balls were projected at 6 m/s towards participants. Participants performed five headers, for the header condition, and five footers for the footer condition. The HRV for resting supine trials, pre-and post-header and footer conditions were assessed for both time and frequency domains. HRV effect sizes were small when comparing conditions, except absolute low frequency (d = 0.61) and standard deviation of the normal-normal (NN) intervals (d = 0.63). Participant retention and adherence were high, without adverse events. Findings suggest HRV is a feasible measure for evaluating the effects of heading on autonomic function

On the Nature of the X-ray Emission from the Ultraluminous X-ray Source, M33 X-8: New Constraints from NuSTAR and XMM-Newton

We present nearly simultaneous NuSTAR and XMM-Newton observations of the nearby (832 kpc) ultraluminous X-ray source (ULX) M33 X-8. M33 X-8 has a 0.3-10 keV luminosity of LX ~ 1.4 x 10^39 erg/s, near the boundary of the "ultraluminous" classification, making it an important source for understanding the link between typical Galactic X-ray binaries and ULXs. Past studies have shown that the 0.3-10 keV spectrum of X-8 can be characterized using an advection-dominated accretion disk model. We find that when fitting to our NuSTAR and XMM-Newton observations, an additional high-energy (>10 keV) Comptonization component is required, which allows us to rule out single advection-dominated disk and classical sub-Eddington models. With our new constraints, we analyze XMM-Newton data taken over the last 17 years to show that small (~30%) variations in the 0.3-10 keV flux of M33 X-8 result in spectral changes similar to those observed for other ULXs. The two most likely phenomenological scenarios suggested by the data are degenerate in terms of constraining the nature of the accreting compact object (i.e., black hole versus neutron star). We further present a search for pulsations using our suite of data; however, no clear pulsations are detected. Future observations designed to observe M33 X-8 at different flux levels across the full 0.3-30 keV range would significantly improve our constraints on the nature of this important source.Comment: Accepted for publication in ApJ (15 pages, 4 tables, 6 figures

Normalized Affymetrix expression data are biased by G-quadruplex formation

Probes with runs of four or more guanines (G-stacks) in their sequences can exhibit a level of hybridization that is unrelated to the expression levels of the mRNA that they are intended to measure. This is most likely caused by the formation of G-quadruplexes, where inter-probe guanines form Hoogsteen hydrogen bonds, which probes with G-stacks are capable of forming. We demonstrate that for a specific microarray data set using the Human HG-U133A Affymetrix GeneChip and RMA normalization there is significant bias in the expression levels, the fold change and the correlations between expression levels. These effects grow more pronounced as the number of G-stack probes in a probe set increases. Approximately 14 of the probe sets are directly affected. The analysis was repeated for a number of other normalization pipelines and two, FARMS and PLIER, minimized the bias to some extent. We estimate that ∼15 of the data sets deposited in the GEO database are susceptible to the effect. The inclusion of G-stack probes in the affected data sets can bias key parameters used in the selection and clustering of genes. The elimination of these probes from any analysis in such affected data sets outweighs the increase of noise in the signal. © 2011 The Author(s)