Stream flow characterization over longwall coal mines in Pennsylvania, Ohio, and West Virginia

Six streams were studied in Ohio, Pennsylvania, and West Virginia to evaluate subsidence impacts from active and abandoned longwall coal mines on stream discharge. Mined longwall panels included in this study ranged in age from five months to fifteen years old and in depth from 100 to 600 feet (30.5 to 182.9 m) beneath the studied streams.;Significant stream flow losses and gains were detected in each stream studied. Comparing longwall panel locations to stream flow measurements, geophysical surveys, and geomorphology surveys, it was concluded that longwall mine subsidence caused some of the detected stream flow losses and gains. Data collected suggests that longwall mine subsidence can impact stream flow and that the impact can be different for different baseflow conditions. The impact on a stream can vary across a longwall panel and the significance of an impact is related to many factors.;The greatest stream flow changes are across the upstream and downstream edges of the longwall subsidence basins, corresponding to zones of tension. Tension zones form fractures within the surface-rock fracture zone (soil zone). Naturally occurring fractures located within the tension zone may also dilate during longwall subsidence and enhance its hydraulic conductivity. Effects to stream discharge from mine subsidence depends on the baseflow conditions. In most cases, normalized stream discharges increase across the fractured tension zones during high baseflow conditions, and declined during low baseflow condition. These characteristics are caused by the increased permeability and storage capacity of dilated fractures within the tension zones.;All streams in the study had a normalized discharge decline across subsided longwall panels. This characteristic is caused by in increase in fractures throughout the panel increasing underflow rates and bank storage potential.;Sediment thickness and particle size distribution fluctuated at measuring stations spaced across the mined longwall panel. Erosion over the upstream tension zone thinned the sediment as the stream entered the subsidence basin. The coarsest and thickest sediment is over the upstream quarter-panel reach where the largest and greatest amount of sediment is deposited from the upstream erosion. A downstream fining trend is detected. This characteristic is caused by the slope of the subsidence basin and its impact on stream power causing it to decrease from the upstream quarter-panel to the downstream quarter-panel

Structural Characterization of Zn(II)-, Co(II)-, and Mn(II)-loaded Forms of the argE-encoded \u3cem\u3eN\u3c/em\u3e-acetyl-L-ornithine Deacetylase from \u3cem\u3eEscherichia coli\u3c/em\u3e

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye–Waller factors for these contributions and a slight reduction in the goodness-of-fit value (f′). Furthermore, the data best fit a model that included a M–M vector at 3.3 and 3.4 Å for Zn(II) and Co(II), respectively, suggesting the formation of a dinuclear site. Multiple scattering contributions from the outer-shell atoms of a histidine-imidazole rings are observed at ~ 3 and 4 Å for Zn(II)- and Co(II)-loaded ArgE suggesting at least one histidine ligand at each metal binding site. Likewise, EXAFS data for Mn(II)-loaded ArgE are dominated by a peak at 2.19 Å that was best fit assuming six light atom (N,O) scatterers. Due to poor signal to noise ratios for the Mn EXAFS spectra, no Mn–Mn vector could be modeled. Peak intensities for [M(II)_(ArgE)] vs. [M(II)M(II)(ArgE)] suggest the Zn(II), Co(II), and Mn(II) bind to ArgE in a cooperative manner. Since no structural data has been reported for any ArgE enzyme, the EXAFS data reported herein represent the first structural glimpse for ArgE enzymes. These data also provide a structural foundation for the future design of small molecules that function as inhibitors of ArgE and may potentially function as a new class of antibiotics

Prepsolv (TM): The optimum alternative to 1,1,1-trichloroethane and methyl ethyl ketone for hand-wipe cleaning of aerospace materials

Engineers at Hercules Aerospace, a rocket motor manufacturer in Utah, have worked closely with chemists at Glidco Organics to study the feasibility of using terpenes for zero-residue wipe cleaning. The result of this work is a technological breakthrough, in which the barrier to ultra-low non-volatile residue formation has been broken. After 2 years of development and testing, SCM Glidco Organics has announced the availability of Glidsafe(registered trademark) Prepsolv(TM): a state-of-the-art ultra-low residue terpene wipe cleaning agent that does not require rinsing. Prepsolv(TM) can successfully be used in simple hand-wipe cleaning processes without fear of leaving surface residues. Industry testing has confirmed that Prepsolv(TM) is not only highly effective, but can even be less expensive to use than traditional cleaning solvents like methyl chloroform. This paper addresses the features and benefits of Prepsolv(TM), and presents performance and material compatibility data that characterizes this unique cleaning agent. Since its commercialization, Hercules Aerospace has chosen Prepsolv(TM) as the optimum cleaning agent to replace ozone-depleting solvents in their weapons factory in Magna, UT. Likewise, Boeing has approved Prepsolv(TM) for cleaning components in the manufacture of commercial aircraft at their facilities in Seattle, WA and Wichita, KS. Additional approvals are forthcoming for this uniquely safe and effective solvent

IBM Watson Supporting Space Radiation

The NASA Human Research Program (HRP) Space Radiation (SR) Program Element has been working with IBM Watson Explorer (WEX) to create a tool that allows researchers to search the NASA SR-funded research corpus to help streamline research and maximize efficiency. The entire corpus of publications from research funded by the NASA SR Program Element has been ingested into WEX to allow for examination of: synergies across funded research areas, gaps in research, and collaboration opportunities. This information will be valuable to both scientists and managers as it will allow analysis related to specific scientific questions, inform key decisions and support cross validation of study results. NASA will also evaluate the potential to make WEX publicly available in order to facilitate proposal generation and to enhance collaborations within and across disciplines

ICML Exploration & Exploitation challenge: Keep it simple!

International audienceRecommendation has become a key feature in the economy of a lot of companies (online shopping, search engines...). There is a lot of work going on regarding recommender systems and there is still a lot to do to improve them. Indeed nowadays in many companies most of the job is done by hand. Moreover even when a supposedly smart recommender system is designed, it is hard to evaluate it without using real audience which obviously involves economic issues. The ICML Exploration & Exploitation challenge is an attempt to make people propose efficient recommendation techniques and particularly focuses on limited computational resources. The challenge also proposes a framework to address the problem of evaluating a recommendation algorithm with real data. We took part in this challenge and achieved the best performances; this paper aims at reporting on this achievement; we also discuss the evaluation process and propose a better one for future challenges of the same kind

Single-Biomolecule Resolution Imaging with an Optical Microscope

A Fluorescence Apertureless Near-field Scanning Optical Microscope (FANSOM) has been developed with FWHM optical resolution below 10 nm when imaging at ~600 nm wavelengths [1]. The apparatus combines an epi fluorescence optical microscope and an atomic force microscope (AFM) to obtain single-molecule sensitivity and optical resolution limited by the sharpness of the AFM probe. The AFM probe is used to stimulate or reduce the detected fluorescence emission rate depending on the AFM tip material and the polarization of the excitation light. The probe-sample interaction is described by near-field dipole-dipole physics, resulting in a stimulated emission rate that varies by r^6. When tapping the probe over the substrate being imaged, the near-field component is sharply modulated at that tapping frequency, thereby enabling separation from the far-field background during post-processing. Images of fluorescent single-molecules taken in a physiological environment will be presented