3,052 research outputs found

    Symplectic Symmetry of the Neutrino Mass and the See-Saw Mechanism

    Get PDF
    We investigate the algebraic structure of the most general neutrino mass Hamiltonian and place the see-saw mechanism in an algebraic framework. We show that this Hamiltonian can be written in terms of the generators of an Sp(4) algebra. The Pauli-Gursey transformation is an SU(2) rotation which is embedded in this Sp(4) group. This SU(2) also generates the see-saw mechanism.Comment: 11 pages, REVTE

    The Student Benefits of a STEMM Scholarship Program

    Get PDF
    According to a recent report by the Center on Education and the Workforce, eight million new jobs will be available in STEMM-related fields by 2018 (https://ohiohighered.org/cof). The distinguished Choose Ohio First Scholarship has been granted to a select group of technology majors at Franklin University since 2012, many of whom have gone on to gain employment in technology-related fields, while remaining in the state of Ohio. Qualitative and quantitative research methods were used to measure the Choose Ohio First Scholars\u27 academic persistence, graduation, and employment compared to the other students, who were declared Computer Science and Management Information Sciences majors, at Franklin University. Initial statistical analysis indicated that there was a positive correlation between the Choose Ohio First Scholars\u27 academic persistence, graduation, and employment. Choose Ohio First Scholars were more likely to graduate from Franklin University than the general student body enrolled in Computer Science and Management Information Sciences majors. Students who receive additional academic support and financial support from their institution might be more likely to graduate and gain employment in their fields of study than students who do not receive additional support.https://fuse.franklin.edu/ss2016/1033/thumbnail.jp

    Neutrino Physics and Nuclear Axial Two-Body Interactions

    Full text link
    We consider the counter-term describing isoscalar axial two-body currents in the nucleon-nucleon interaction, L1A, in the effective field theory approach. We determine this quantity using the solar neutrino data. We investigate the variation of L1A when different sets of data are used.Comment: 8 pages with 4 figures. To be published in the Proceedings of the Conference "Blueprints For The Nucleus: From First Principles to Collective Motion" held at Feza Gursey Institute, Istanbul, Turkey; May 17 -22, 200

    Pictures of Synthetic Biology: A reflective discussion of the representation of Synthetic Biology (SB) in the German-language media and by SB experts

    Get PDF
    This article is concerned with the representation of Synthetic Biology in the media and by biotechnology experts. An analysis was made of German-language media articles published between 2004 and 2008, and interviews with biotechnology-experts at the Synthetic Biology conference SB 3.0 in Zurich 2007. The results have been reflected in terms of the definition of Synthetic Biology, applications of Synthetic Biology and the perspectives of opportunities and risks. In the media, Synthetic Biology is represented as a new scientific field of biology with an engineering-like thinking, while the scientists interviewed mostly define Synthetic Biology as contrary to nature and the natural system. Media articles present Synthetic Biology broadly with positive potential and inform the publics less about the potential risks than about the benefits of Synthetic Biology. In contrast, the experts interviewed reflect more on the risks than the opportunities of Synthetic Biology. Both used metaphors to describe Synthetic Biology and its aspects

    (3+2) Neutrino Scheme From A Singular Double See-Saw Mechanism

    Full text link
    We obtain a 3+2 neutrino spectrum within a left-right symmetric framework by invoking a singular double see-saw mechanism. Higgs doublets are employed to break SUR(2)SU_{R}(2) and three additional fermions, singlets under the left-right symmetric gauge group, are included. The introduction of a singularity into the singlet fermion Majorana mass matrix results in a light neutrino sector of three neutrinos containing predominantly ναL\nu_{\alpha L}, α=e,μ,τ\alpha=e,\mu,\tau, separated from two neutrinos containing a small ναL\nu_{\alpha L} component. The resulting active-sterile mixing in the 5×55\times 5 mixing matrix is specified once the mass eigenvalues and the 3×33\times3 submatrix corresponding to the MNS mixing matrix are known.Comment: 5 pages, matches published versio

    Fe1-xNix alloy nanoparticles encapsulated inside carbon nanotubes: Controlled synthesis, structure and magnetic properties

    Get PDF
    In the present work, different synthesis procedures have been demonstrated to fill carbon nanotubes (CNTs) with Fe1-xNix alloy nanoparticles (x = 0.33, 0.5). CNTs act as templates for the encapsulation of magnetic nanoparticles, and provide a protective shield against oxidation as well as prevent nanoparticles agglomeration. By variation of the reaction parameters, the purity of the samples, degree of filling, the composition and size of filling nanoparticles have been tailored and therefore the magnetic properties. The samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Bright-field (BF) TEM tomography, X-ray powder diffraction, superconducting quantum interference device (SQUID) and thermogravimetric analysis (TGA). The Fe1-x Nix-filled CNTs show a huge enhancement in the coercive fields compared to the corresponding bulk materials, which make them excellent candidates for several applications such as magnetic storage devices

    Four-Step Domino Reaction Enables Fully Controlled Non-Statistical Synthesis of Hexaarylbenzene with Six Different Aryl Groups*

    Get PDF
    Hexaarylbenzene (HAB) derivatives are versatile aromatic systems playing a significant role as chromophores, liquid crystalline materials, molecular receptors, molecular-scale devices, organic light-emitting diodes and candidates for organic electronics. Statistical synthesis of simple symmetrical HABs is known via cyclotrimerization or Diels–Alder reactions. By contrast, the synthesis of more complex, asymmetrical systems, and without involvement of statistical steps, remains an unsolved problem. Here we present a generally applicable synthetic strategy to access asymmetrical HAB via an atom-economical and high-yielding metal-free four-step domino reaction using nitrostyrenes and α,α-dicyanoolefins as easily available starting materials. Resulting domino product—functionalized triarylbenzene (TAB)—can be used as a key starting compound to furnish asymmetrically substituted hexaarylbenzenes in high overall yield and without involvement of statistical steps. This straightforward domino process represents a distinct approach to create diverse and still unexplored HAB scaffolds, containing six different aromatic rings around central benzene core. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH Gmb

    Influence of electron correlations on ground-state properties of III-V semiconductors

    Full text link
    Lattice constants and bulk moduli of eleven cubic III-V semiconductors are calculated using an ab initio scheme. Correlation contributions of the valence electrons, in particular, are determined using increments for localized bonds and for pairs and triples of such bonds; individual increments, in turn, are evaluated using the coupled cluster approach with single and double excitations. Core-valence correlation is taken into account by means of a core polarization potential. Combining the results at the correlated level with corresponding Hartree-Fock data, we obtain lattice constants which agree with experiment within an average error of -0.2%; bulk moduli are accurate to +4%. We discuss in detail the influence of the various correlation contributions on lattice constants and bulk moduli.Comment: 4 pages, Latex, no figures, Phys. Rev. B, accepte

    Trap-Integrated Superconducting Nanowire Single-Photon Detectors with Improved RF Tolerance for Trapped-Ion Qubit State Readout

    Full text link
    State readout of trapped-ion qubits with trap-integrated detectors can address important challenges for scalable quantum computing, but the strong rf electric fields used for trapping can impact detector performance. Here, we report on NbTiN superconducting nanowire single-photon detectors (SNSPDs) employing grounded aluminum mirrors as electrical shielding that are integrated into linear surface-electrode rf ion traps. The shielded SNSPDs can be successfully operated at applied rf trapping potentials of up to 54 Vpeak\mathrm{54\,V_{peak}} at 70 MHz\mathrm{70\,MHz} and temperatures of up to 6 K\mathrm{6\,K}, with a maximum system detection efficiency of 68 %\mathrm{68\,\%}. This performance should be sufficient to enable parallel high-fidelity state readout of a wide range of trapped ion species in typical cryogenic apparatus.Comment: 6 pages, 4 figures. The following article has been submitted to Applied Physics Letter

    Systematic investigations of annealing and functionalization of carbon nanotube yarns

    Get PDF
    Carbon nanotube yarns (CNY) are a novel carbonaceous material and have received a great deal of interest since the beginning of the 21st century. CNY are of particular interest due to their useful heat conducting, electrical conducting, and mechanical properties. The electrical conductivity of carbon nanotube yarns can also be influenced by functionalization and annealing. A systematical study of this post synthetic treatment will assist in understanding what factors influences the conductivity of these materials. In this investigation, it is shown that the electrical conductivity can be increased by a factor of 2 and 5.5 through functionalization with acids and high temperature annealing respectively. The scale of the enhancement is dependent on the reducing of intertube space in case of functionalization. For annealing, not only is the highly graphitic structure of the carbon nanotubes (CNT) important, but it is also shown to influence the residual amorphous carbon in the structure. The promising results of this study can help to utilize CNY as a replacement for common materials in the field of electrical wiring
    • …
    corecore