23,057 research outputs found

    Ammonia oxidation is not required for growth of Group 1.1c soil Thaumarchaeota

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    © FEMS 2015. FUNDING EBW is funded by Centre for Genome Enabled Biology and Medicine, University of Aberdeen.Peer reviewedPublisher PD

    Keck Studies of M31's Stellar Halo

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    We present Keck 10-meter/LRIS spectra of candidate red giants in the halo of M31, located at a projected radius of R=19kpc on the minor axis. These spectroscopic targets have been selected using a combination of UBRI-based and morphological screening to eliminate background galaxies. Radial velocity measurements are used to separate M31 halo giants from foreground Milky Way dwarf stars, M31 disk stars, and residual background galaxies. The metallicity of each M31 halo giant is measured using standard photometric and spectroscopic techniques, the latter based on the strength of the CaII triplet. The various [Fe/H] estimates are in rough agreement with one another. The data reveal a large spread (>2dex) in [Fe/H] in M31's halo; there is no strong radial [Fe/H] gradient. LRIS and HIRES spectra are also presented for red giants in five dwarf spheroidal satellites of M31: AndI, AndIII, AndV, AndVI, and AndVII. There appears to be a significant metallicity spread in AndVI and possibly in AndI. The new radial velocity data on these outer dwarfs are used to constrain the total mass of M31: the best estimate is under 10^(12)Msun, somewhat less than the best estimate for the Milky Way.Comment: 12 pages, 7 figures, Proceedings of SPIE Conference: Discoveries and Research Prospects with 8-10 Meter Class Telescopes (Munich March 2000

    A universal platform for magnetostriction measurements in thin films

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    We present a universal nanomechanical sensing platform for the investigation of magnetostriction in thin films. It is based on a doubly-clamped silicon nitride nanobeam resonator covered with a thin magnetostrictive film. Changing the magnetization direction within the film plane by an applied magnetic field generates a magnetostrictive stress and thus changes the resonance frequency of the nanobeam. A measurement of the resulting resonance frequency shift, e.g. by optical interferometry, allows to quantitatively determine the magnetostriction constants of the thin film. We use this method to determine the magnetostriction constants of a 10nm thick polycrystalline cobalt film, showing very good agreement with literature values. The presented technique can be useful in particular for the precise measurement of magnetostriction in a variety of (conducting and insulating) thin films, which can be deposited by e.g. electron beam deposition, thermal evaporation or sputtering

    Spin transport and spin dephasing in zinc oxide

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    The wide bandgap semiconductor ZnO is interesting for spintronic applications because of its small spin-orbit coupling implying a large spin coherence length. Utilizing vertical spin valve devices with ferromagnetic electrodes (TiN/Co/ZnO/Ni/Au), we study the spin-polarized transport across ZnO in all-electrical experiments. The measured magnetoresistance agrees well with the prediction of a two spin channel model with spin-dependent interface resistance. Fitting the data yields spin diffusion lengths of 10.8nm (2K), 10.7nm (10K), and 6.2nm (200K) in ZnO, corresponding to spin lifetimes of 2.6ns (2K), 2.0ns (10K), and 31ps (200K).Comment: 7 pages, 5 figures; supplemental material adde

    Pendampingan Pengelolaan Sampah Berbasis Komunitas Posyandu Kartinikelurahan Ngaliyan - Kota Semarang

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    The objectives of this empowerment to the strengthening of environmental awareness according to the principles of conservation to provide guidance to residents of RT 13 / RW 06 Sub Ngaliyan through knowledge transfer include matters related to the management and processing of kitchen waste, increase the participation of community members, and strengthening to the community as a pioneer of environmental care. Activity methods consistent measures of community assistance through: socialization, practice, and mentoring as well as to monitor the success of the activities. Kitchen waste separation has been carried out by members of the community according to type, namely: assortment of vegetables, plastic, leftover food and other waste disposed in the trash that has been owned by each member. Participatory members in environmental management in accordance prinsi-conservation principles were shared by all (100%) members, this condition is relatively easy to do because of the community living in housing that is built. The practice of processing kitchen waste into compost is done by three teams consisting of 5-7 family. Results compost is used to fertilize ornamental plants and to fertilize plants roadside South Karonsih. Indicators of success are known activities of enthusiastic participants in the discussion that demonstrate mastery of the material. In addition it is nevertheless manage and process waste even without assistance

    L\'{e}vy-based growth models

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    In the present paper, we give a condensed review, for the nonspecialist reader, of a new modelling framework for spatio-temporal processes, based on L\'{e}vy theory. We show the potential of the approach in stochastic geometry and spatial statistics by studying L\'{e}vy-based growth modelling of planar objects. The growth models considered are spatio-temporal stochastic processes on the circle. As a by product, flexible new models for space--time covariance functions on the circle are provided. An application of the L\'{e}vy-based growth models to tumour growth is discussed.Comment: Published in at http://dx.doi.org/10.3150/07-BEJ6130 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

    Bloch oscillations of Bose-Einstein condensates: Quantum counterpart of dynamical instability

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    We study the Bloch dynamics of a quasi one-dimensional Bose-Einstein condensate of cold atoms in a tilted optical lattice modeled by a Hamiltonian of Bose-Hubbard type: The corresponding mean-field system described by a discrete nonlinear Schr\"odinger equation can show a dynamical (or modulation) instability due to chaotic dynamics and equipartition over the quasimomentum modes. It is shown, that these phenomena are related to a depletion of the Floquet-Bogoliubov states and a decoherence of the condensate in the many-particle description. Three different types of dynamics are distinguished: (i) decaying oscillations in the region of dynamical instability, and (ii) persisting Bloch oscillations or (iii) periodic decay and revivals in the region of stability.Comment: 12 pages, 14 figure

    Grafting melons onto potential cucumis spp. rootstocks

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    Cucumís melo is an economically importar]t crop. Its culture is hampered by differen t types of soil stresses. Grafting melons onto different resistant cucurbits belonging to the genera, Cucurbíta, Lagenaría, Luffa, etc. have been successfully used to avoid these problems. However, me Ion quality has been nega.tively modified as a consequence of grafting. In general, variation in fruit shape, seed cavity and sugar content have been observed. The use of rootstocks more genetically c\oser to the melon scions could be useful to obtain fru i ts with better quality from melon grafted plantsPostprint (published version

    Results on the nucleon spin structure

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    SMC performed an investigation of the spin structure of the nucleon by measuring deep inelastic scattering of polarised muons off polarised protons and deuterons. A summary of the results for spin structure functions and sum rules is given.Comment: 8 pages, LaTeX, Talk given at the Workshop on "Symmetry and Spin - PRAHA98", Prag, September 1998. Proceedings to be published by Czech. Journ. Phy
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