Imaging the formation of high-energy dispersion anomalies in the actinide UCoGa5_5

We use angle-resolved photoemission spectroscopy (ARPES) to image the emergence of substaintial dispersion anomalies in the electronic renormalization of the actinide compound UCoGa$_5$ which was presumed to belong to a conventional Fermi liquid family. Kinks or abrupt breaks in the slope of the quasiparticle dispersion are detected both at low ($\sim$130 meV) and high ($\sim$1 eV) binding energies below the Fermi energy, ruling out any significant contribution of phonons. We perform numerical calculations to demonstrate that the anomalies are adequately described by coupling between itinerant fermions and spin fluctuations arising from the particle-hole continuum of the spin-orbit split $5f$ states of uranium. These anomalies are resemble the `waterfall' phenomenon of the high-temperature copper-oxide superconductors, suggesting that spin fluctuations are a generic route toward multiform electronic phases in correlated materials as different as high-temperature superconductors and actinides.Comment: 10 pages including supplementary material, Accepted for publication in PR

Polymeric routes to silicon carbide and silicon oxycarbide CMC

An overview of two approaches to the formation of ceramic composite matrices from polymeric precursors is presented. Copolymerization of alkyl- and alkenylsilanes (RSiH3) represents a new precursor system for the production of Beta-SiC on pyrolysis, with copolymer composition controlling polymer structure, char yield, and ceramic stoichiometry and morphology. Polysilsesquioxanes which are synthesized readily and can be handled in air serve as precursors to Si-C-O ceramics. Copolymers of phenyl and methyl silsesquioxanes display rheological properties favorable for composite fabrication; these can be tailored by control of pH, water/methoxy ratio and copolymer composition. Composites obtained from these utilize a carbon coated, eight harness satin weave Nicalon cloth reinforcement. The material exhibits nonlinear stress-strain behavior in tension

Preservation of Energy-Time Entanglement in a Slow Light Medium

We demonstrate the preservation of entanglement of an energy-time entangled biphoton through a slow light medium. Using the D1 and D2 fine structure resonances of Rubidium, we delay one photon of the 1.5 THz biphoton by ∼1.3 correlation lengths and measure the fourth order correlation fringes. After the group delay the fringe visibility is reduced from 97.0±4.4% to 80.0±4.8%, but is still sufficient to violate a Bell inequality. We show that temporal broadening is the primary mechanism for reducing the fringe visibility and that smaller bandwidths lead to greatly reduced broadening

Fan Assessment Numeration System (FANS) Design and Calibration Specifications

A device for in-situ fan airflow measurement, called the Fan Assessment Numeration System (FANS) device, previously developed and constructed at the USDA-ARS Southern Poultry Research Laboratory, was refined at University of Kentucky as part of a project for quantifying building emissions from poultry and livestock operations. The FANS incorporates an array of five propeller anemometers to perform a real-time traverse of the air flow entering fans of up to 137 cm (54 in) diameter. Details of the updated design, including hardware, software, and calibration methodology are presented. An error analysis of the flow rate, and calibration results from ten units recently manufactured, is provided. Sufficient details of fabrication and calibration are presented so that interested readers can replicate a FANS for their use. Full design details are provided at www.bae.uky.edu/IFAFS/FANS

Kohn-Sham accuracy from orbital-free density functional theory via Δ\Delta-machine learning

We present a $\Delta$-machine learning model for obtaining Kohn-Sham accuracy from orbital-free density functional theory (DFT) calculations. In particular, we employ a machine learned force field (MLFF) scheme based on the kernel method to capture the difference between Kohn-Sham and orbital-free DFT energies/forces. We implement this model in the context of on-the-fly molecular dynamics simulations, and study its accuracy, performance, and sensitivity to parameters for representative systems. We find that the formalism not only improves the accuracy of Thomas-Fermi-von Weizs{\"a}cker (TFW) orbital-free energies and forces by more than two orders of magnitude, but is also more accurate than MLFFs based solely on Kohn-Sham DFT, while being more efficient and less sensitive to model parameters. We apply the framework to study the structure of molten Al$_{0.88}$Si$_{0.12}$, the results suggesting no aggregation of Si atoms, in agreement with a previous Kohn-Sham study performed at an order of magnitude smaller length and time scales.Comment: 10 pages, 7 figures, 2 table

A petrological and geochronological study of the Koralpe-Saualpe-Pohorje (KSP) Complex (Eastern Alps)

The KSP Complex in the Eastern Alps stretches from SE Austria to NW Slovenia and is a lithologically heterogenous (U)HP nappe with abundant eclogite lenses embedded in gneissic and metasedimentary rocks. An increase of metamorphic peak pressure-temperature (PT) conditions from NW to SE with UHP conditions for Pohorje was previously proposed based on thermodynamic modelling. The formation history of the KSP Complex is still debated. Here, we investigate in detail the PT conditions during the formation of the complex along a NW-SE transect following the direction of subduction with a new combined approach for this area of Raman spectroscopy of quartz inclusions in garnet, Zr-in-rutile thermometry and U/Pb dating on garnets. This is the first study within the KSP complex where quartz inclusions in garnet elastic barometry was conducted to determine the entrapment pressures, which correspond to the minimum pressure conditions present during the entrapment of quartz inside garnet. Approximately 5000 quartz inclusions inside the inner part of the garnets were investigated. The garnet rims contain almost no inclusions. The eclogites yield pressures of max. 1.9 GPa across the KSP complex, indicating no pressure increase from the NW to SE (Fig. 1). The metasediments and gneisses show overall lower pressures with ca. 1.4 GPa. Temperatures based on Zr-in-rutile thermometry was conducted on 194 rutile grains in different microstructural positions. The results do not indicate a temperature increase from NW to SE, with ca. 640 (±30)°C across the whole KSP Complex (Fig. 1), based on very similar Zr contents of ca. 270 ppm. The new approach of insitu U/Pb dating on garnets allows the age determination of the different growth zones in garnet and makes it an ideal tool to decipher metamorphic processes. The metasediments provide the following ages (Fig. 1) for the Koralpe 101.3 ± 6.6 Ma (throughout garnet); Saualpe 224.6 ± 31 Ma (core) and 115.5 ± 17.7 Ma (rim); Pohorje 104.2 ± 7.1 Ma to 105.5 ± 17.2 (throughout garnet). Garnet in eclogite from Koralpe is 112.8 ± 9.9 Ma. In general, the garnets in eclogite from the KSP complex are very poor in U. The obtained ages are interpreted to be metamorphic peak ages with a Cretaceous event at c. 100 Ma and a Triassic/Permian event reported in garnet cores from metasediments from Saualpe which is in line with existing literature. Combined with results of previous studies of eclogite ages, we suggest, that the eclogites are former (probably Permian) gabbro intrusions that experienced HP conditions during the Eoalpine orogeny. Whereas garnet ages of metasediments from Saualpe provide evidence for a polymetamorphic history

Selection of chromosomal DNA libraries using a multiplex CRISPR system.

The directed evolution of biomolecules to improve or change their activity is central to many engineering and synthetic biology efforts. However, selecting improved variants from gene libraries in living cells requires plasmid expression systems that suffer from variable copy number effects, or the use of complex marker-dependent chromosomal integration strategies. We developed quantitative gene assembly and DNA library insertion into the Saccharomyces cerevisiae genome by optimizing an efficient single-step and marker-free genome editing system using CRISPR-Cas9. With this Multiplex CRISPR (CRISPRm) system, we selected an improved cellobiose utilization pathway in diploid yeast in a single round of mutagenesis and selection, which increased cellobiose fermentation rates by over 10-fold. Mutations recovered in the best cellodextrin transporters reveal synergy between substrate binding and transporter dynamics, and demonstrate the power of CRISPRm to accelerate selection experiments and discoveries of the molecular determinants that enhance biomolecule function

A Gemini/GMOS Study of Intermediate Luminosity Early-Type Virgo Cluster Galaxies. I. Globular Cluster and Stellar Kinematics

We present a kinematic analysis of the globular cluster systems and diffuse stellar light of four intermediate luminosity (sub-$L^{\ast}$) early-type galaxies in the Virgo cluster based on Gemini/GMOS data. Our galaxy sample is fainter ($-23.8<M_K<-22.7$) than most previous studies, nearly doubling the number of galaxies in this magnitude range that now have GC kinematics. The data for the diffuse light extends to $4R_e$, and the data for the globular clusters reaches 8--$12R_e$. We find that the kinematics in these outer regions are all different despite the fact that these four galaxies have similar photometric properties, and are uniformly classified as "fast rotators" from their stellar kinematics within $1R_e$. The globular cluster systems exhibit a wide range of kinematic morphology. The rotation axis and amplitude can change between the inner and outer regions, including a case of counter-rotation. This difference shows the importance of wide-field kinematic studies, and shows that stellar and GC kinematics can change significantly as one moves beyond the inner regions of galaxies. Moreover, the kinematics of the globular cluster systems can differ from that of the stars, suggesting that the formation of the two populations are also distinct.Comment: 24 pages, 21 figures, 9 table, ApJ in pres