502 research outputs found

    Interstitial compounds as fuel cell catalysts - Their preparative techniques and electrochemical testing

    Get PDF
    Preparation and electrochemical testing methods for fuel cell catalysts using interstitial compound

    Development of an improved oxygen electrode for use in alkaline H2-O2 fuel cells Quarterly report, Oct. 1 - Dec. 31, 1966

    Get PDF
    Interstitial compounds of transition elements prepared for improving oxygen electrode in alkaline hydrox fuel cel

    Development of an improved oxygen electrode for use in alkaline H2-O2 fuel cells Quarterly report, Apr. 1 - Jun. 30, 1967

    Get PDF
    Preparation of institial compounds of transition metals for hydrogen oxygen fuel cell cathode

    Electronic Structure of Te and As Covered Si(211)

    Get PDF
    Electronic and atomic structures of the clean, and As and Te covered Si(211) surface are studied using pseudopotential density functional method. The clean surface is found to have (2 X 1) and rebonded (1 X 1) reconstructions as stable surface structures, but no \pi-bonded chain reconstruction. Binding energies of As and Te adatoms at a number of symmetry sites on the ideal and (2 X 1) reconstructed surfaces have been calculated because of their importance in the epitaxial growth of CdTe and other materials on the Si(211) surface. The special symmetry sites on these surfaces having the highest binding energies for isolated As and Te adatoms are identified. But more significantly, several sites are found to be nearly degenerate in binding energy values. This has important consequences for epitaxial growth processes. Optimal structures calculated for 0.5 ML of As and Te coverage reveal that the As adatoms dimerize on the surface while the Te adatoms do not. However, both As and Te covered surfaces are found to be metallic in nature.Comment: 17 pages, 9 figures, accepted for publication in Phys. Rev.

    Ultrafast Optical-Pump Terahertz-Probe Spectroscopy of the Carrier Relaxation and Recombination Dynamics in Epitaxial Graphene

    Full text link
    The ultrafast relaxation and recombination dynamics of photogenerated electrons and holes in epitaxial graphene are studied using optical-pump Terahertz-probe spectroscopy. The conductivity in graphene at Terahertz frequencies depends on the carrier concentration as well as the carrier distribution in energy. Time-resolved studies of the conductivity can therefore be used to probe the dynamics associated with carrier intraband relaxation and interband recombination. We report the electron-hole recombination times in epitaxial graphene for the first time. Our results show that carrier cooling occurs on sub-picosecond time scales and that interband recombination times are carrier density dependent.Comment: 4 pages, 5 figure

    Rumor Surveillance and Avian Influenza H5N1

    Get PDF
    We describe the enhanced rumor surveillance during the avian influenza H5N1 outbreak in 2004. The World Health Organization’s Western Pacific Regional Office identified 40 rumors; 9 were verified to be true. Rumor surveillance informed immediate public health action and prevented unnecessary and costly responses

    Metropolitan quantum key distribution with silicon photonics

    Full text link
    Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks

    Development and regulation of exosome-based therapy products

    Get PDF
    Recently, various innovative therapies involving the ex vivo manipulation and subsequent reintroduction of exosome-based therapeutics into humans have been developed and validated, although no exosome-based therapeutics have yet to be brought into the clinic. Exosomes are nanosized vesicles secreted by many cells that utilize them for cell-to-cell communications to facilitate transport of proteins and genetic material. Comprised of cellular membranes with multiple adhesive proteins on their surface, exosomes offer distinct advantages that exceptionally position them as highly effective drug carriers. Additionally, exosomes can exert unique biological activity reflective of their origin that may be used for therapy of various diseases. In fact, exosomes have benefits of both synthetic nanocarriers and cell-mediated drug delivery systems, and avoid their limitations. This concise review highlights the recent developments in exosome-based drug delivery systems and the main regulatory considerations for using this type of therapeutic in clinic. WIREs Nanomed Nanobiotechnol 2016, 8:744–757. doi: 10.1002/wnan.1395. For further resources related to this article, please visit the WIREs website

    Effects of impurity scattering on electron-phonon resonances in semiconductor superlattice high-field transport

    Full text link
    A non-equilibrium Green's function method is applied to model high-field quantum transport and electron-phonon resonances in semiconductor superlattices. The field-dependent density of states for elastic (impurity) scattering is found non-perturbatively in an approach which can be applied to both high and low electric fields. I-V curves, and specifically electron-phonon resonances, are calculated by treating the inelastic (LO phonon) scattering perturbatively. Calculations show how strong impurity scattering suppresses the electron-phonon resonance peaks in I-V curves, and their detailed sensitivity to the size, strength and concentration of impurities.Comment: 7 figures, 1 tabl

    Rural Revitalization in New Mexico

    Get PDF
    The Rural Education Bureau of the New Mexico Public Education Department has established a program to address the special needs of schools and communities in the extensive rural areas of the state. High poverty rates, depopulation and a general lack of viable economic opportunity have marked rural New Mexico for decades. The program underway aims at establishing holistic community socioeconomic revitalization at the grass roots level with the schools playing a leading role. Initiatives include community conversations with key leaders to determine necessary steps to take in encouraging economic growth and attracting businesses, the institution of entrepreneurship within the community, the transformation of the school into a community resource and the encouragement of place-based education within schools. In the second year of this program there are 13 school districts actively involved in the enhancement of their schools and community. The program adopted many of the principles for rural revitalization seen in the remote communities of South Australia
    • …
    corecore