1,493 research outputs found

    A Model for the Stray Light Contamination of the UVCS Instrument on SOHO

    Full text link
    We present a detailed model of stray-light suppression in the spectrometer channels of the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. The control of diffracted and scattered stray light from the bright solar disk is one of the most important tasks of a coronagraph. We compute the fractions of light that diffract past the UVCS external occulter and non-specularly pass into the spectrometer slit. The diffracted component of the stray light depends on the finite aperture of the primary mirror and on its figure. The amount of non-specular scattering depends mainly on the micro-roughness of the mirror. For reasonable choices of these quantities, the modeled stray-light fraction agrees well with measurements of stray light made both in the laboratory and during the UVCS mission. The models were constructed for the bright H I Lyman alpha emission line, but they are applicable to other spectral lines as well.Comment: 19 pages, 5 figures, Solar Physics, in pres

    Detection and Quantification of Grapevine Bunch Rot Using Functional Data Analysis and Canonical Variate Analysis Biplots of Infrared Spectral Data

    Get PDF
    Grapevine bunch rot assessment has economic significance to wineries. Industrial working conditionsrequire rapid assessment methods to meet the time constraints typically associated with grape intakeat large wineries. Naturally rot-affected and healthy white wine grape bunches were collected overfive vintages (2013 to 2016, 2020). Spectral data of 382 grape must samples were acquired using threedifferent, but same-type attenuated total reflection mid-infrared (ATR-MIR) ALPHA spectrometers. Thepractical industrial problem of wavenumber shifts collected with different spectrometers was overcome byapplying functional data analysis (FDA). FDA improved the data quality and boosted data mining effortsin the sample set. Canonical variate analysis (CVA) biplots were employed to visualise the detection andquantification of rot. When adding 90 % alpha-bags to CVA biplots minimal overlap between rot-affected(Yes) and healthy (No) samples was observed. Several bands were observed in the region 1734 cm-1 to 1722cm-1 which correlated with the separation between rot-affected and healthy grape musts. These bandsconnect to the C=O stretching of the functional groups of carboxylic acids. In addition, wavenumber 1041cm-1, presenting the functional group of ethanol, contributed to the separation between categories (severity% range). ATR-MIR could provide a sustainable alternative for rapid and automated rot assessment.However, qualitative severity quantification of rot was limited to only discriminating between healthy andsevere rot (> 40 %). This study is novel in applying FDA to correct wavenumber shifts in ATR-MIR spectraldata. Furthermore, visualisation of the viticultural data set using CVA biplots is a novel application of thistechnique

    The Generalized Dirichlet to Neumann map for the KdV equation on the half-line

    Full text link
    For the two versions of the KdV equation on the positive half-line an initial-boundary value problem is well posed if one prescribes an initial condition plus either one boundary condition if qtq_{t} and qxxxq_{xxx} have the same sign (KdVI) or two boundary conditions if qtq_{t} and qxxxq_{xxx} have opposite sign (KdVII). Constructing the generalized Dirichlet to Neumann map for the above problems means characterizing the unknown boundary values in terms of the given initial and boundary conditions. For example, if {q(x,0),q(0,t)}\{q(x,0),q(0,t) \} and {q(x,0),q(0,t),qx(0,t)}\{q(x,0),q(0,t),q_{x}(0,t) \} are given for the KdVI and KdVII equations, respectively, then one must construct the unknown boundary values {qx(0,t),qxx(0,t)}\{q_{x}(0,t),q_{xx}(0,t) \} and {qxx(0,t)}\{q_{xx}(0,t) \}, respectively. We show that this can be achieved without solving for q(x,t)q(x,t) by analysing a certain ``global relation'' which couples the given initial and boundary conditions with the unknown boundary values, as well as with the function Φ(t)(t,k)\Phi^{(t)}(t,k), where Φ(t)\Phi^{(t)} satisifies the tt-part of the associated Lax pair evaluated at x=0x=0. Indeed, by employing a Gelfand--Levitan--Marchenko triangular representation for Φ(t)\Phi^{(t)}, the global relation can be solved \emph{explicitly} for the unknown boundary values in terms of the given initial and boundary conditions and the function Φ(t)\Phi^{(t)}. This yields the unknown boundary values in terms of a nonlinear Volterra integral equation.Comment: 21 pages, 3 figure

    In-Situ Li-Ion Pouch Cell Diagnostics Utilising Plasmonic Based Optical Fibre Sensors

    Get PDF
    As the drive to improve the cost, performance characteristics and safety of lithium-ion batteries increases with adoption, one area where significant value could be added is that of battery diagnostics. This paper documents an investigation into the use of plasmonic-based optical fibre sensors, inserted internally into 1.4 Ah lithium-ion pouch cells, as a real time and in-situ diagnostic technique. The successful implementation of the fibres inside pouch cells is detailed and promising correlation with battery state is reported, while having negligible impact on cell performance in terms of capacity and columbic efficiency. The testing carried out includes standard cycling and galvanostatic intermittent titration technique (GITT) tests, and the use of a reference electrode to correlate with the anode and cathode readings separately. Further observations are made around the sensor and analyte interaction mechanisms, robustness of sensors and suggested further developments. These finding show that a plasmonic-based optical fibre sensor may have potential as an opto-electrochemical diagnostic technique for lithium-ion batteries, offering an unprecedented view into internal cell phenomena

    An inverted-sandwich diuranium μ-η5:η5-cyclo-P5 complex supported by U-P5 δ-bonding

    Get PDF
    Reaction of [U(TrenTIPS)] [1, TrenTIPS=N(CH2CH2NSiiPr3)3] with 0.25 equivalents of P4 reproducibly affords the unprecedented actinide inverted sandwich cyclo-P5 complex [{U(TrenTIPS)}2(μ-η5:η5-cyclo-P5)] (2). All prior examples of cyclo-P5 are stabilized by d-block metals, so 2 shows that cyclo-P5 does not require d-block ions to be prepared. Although cyclo-P5 is isolobal to cyclopentadienyl, which usually bonds to metals via σ- and π-interactions with minimal δ-bonding, theoretical calculations suggest the principal bonding in the U(P5)U unit is polarized δ-bonding. Surprisingly, the characterization data are overall consistent with charge transfer from uranium to the cyclo-P5 unit to give a cyclo-P5 charge state that approximates to a dianionic formulation. This is ascribed to the larger size and superior acceptor character of cyclo-P5 compared to cyclopentadienyl, the strongly reducing nature of uranium(III), and the availability of uranium δ-symmetry 5f orbitals

    Electron Spin Resonance Above Tc In Layered Manganites

    Get PDF
    We have performed electron spin resonance (ESR) and dc magnetization measurements on single crystals of La2(1-x)Sr1+2xMn2O7 up to 800 K with special emphasis on the x = 0.4 composition. The ESR linewidth shows behavior similar to that observed in the three-dimensional perovskites and above ∼500 K can be described by a universal expression ΔHpp(T)=[C/Tχ(T)]ΔHpp (∞). The linewidth and the resonance field become anisotropic below ∼500 K. The anisotropy in the resonance field is proportional to the magnetization M, and we concluded that it is intrinsic to the system. We show that demagnetization effects can explain only part of the anisotropy. The remainder arises from short-range uniaxial terms in the Hamiltonian that are associated with the crystal field and Dzialozhinsky-Moriya interactions. The anisotropy in the linewidth is attributed to the easy-plane ferromagnetic ordering, which also arises from the short-range anisotropy.631717441311744136Ruddlesden, S.N., Popper, P., (1958) Acta Crystallogr., 11, p. 54Moritomo, Y., Asamitsu, A., Kuwahara, H., Tokura, Y., (1996) Nature (London), 380, p. 141Causa, M.T., Tovar, M., Caneiro, A., Prado, F., Ibanez, G., Ramos, C.A., Butera, A., Oseroff, S.B., (1998) Phys. Rev. B, 58, p. 3233Causa, M.T., Alejandro, G., Tovar, M., Pagliuso, P.G., Rettori, C., Oseroff, S.B., Subramanian, M.A., (1999) J. Appl. Phys., 85, p. 5408Huber, D.L., Alejandro, G., Caneiro, A., Causa, M.T., Prado, F., Tovar, M., Oseroff, S.B., (1999) Phys. Rev. B, 60, p. 12155Oseroff, S.B., Moreno, N.O., Pagliuso, P.G., Rettori, C., Huber, D.L., Gardner, J.S., Sarrao, J.L., Alascio, B.R., (2000) J. Appl. Phys., 87, p. 5810Seehra, M.S., Ibrahim, M.M., Babu, V.S., Srinivasan, G., (1996) J. Phys.: Condens. Matter, 8, p. 11283Dominguez, M., Lofland, S.E., Bhagat, S.M., Raychaudhuri, A.K., Ju, H.L., Venkates, T., Greene, R.L., (1996) Solid State Commun., 97, p. 193Lofland, S.E., Kim, P., Dahiroc, P., Bhagat, S.M., Tyagi, S.D., Karabashev, S.G., Shultyatev, D.A., Mukovskii, Y., (1997) Phys. Lett. A, 233, p. 476Kimura, T., Tomioka, Y., Kuwahara, H., Asamitsu, A., Tamura, M., Tokura, Y., (1996) Science, 274, p. 1698Perring, T.G., Aeppli, G., Moritomo, Y., Tokura, Y., (1997) Phys. Rev. Lett., 78, p. 3197Zhou, J.-S., Goodenough, J.B., Mitchell, J.F., (1998) Phys. Rev. B, 58, p. 579Zhou, J.-S., Goodenough, J.B., (1998) Phys. Rev. Lett., 80, p. 2665Kelley, T.M., Argyriou, D.N., Robinson, R.A., Nakotte, H., Mitchell, J.F., Osbron, R., Jorgensen, J.D., (1998) Physica B, 241-243, p. 439Heffner, R.H., MacLaughlin, D.E., Nieuwenhuys, G.J., Kimura, T., Luke, G.M., Tokura, Y., Uemura, Y.J., (1998) Phys. Rev. Lett., 81, p. 1706Potter, C.D., Swiatek, M., Bader, S.D., Argyriou, D.N., Mitchell, J.F., Miller, D.J., Hinks, D.G., Jorgensen, J.D., (1998) Phys. Rev. B, 57, p. 72Chauvet, O., Goglio, G., Molinie, P., Corraze, B., Brohan, L., (1998) Phys. Rev. Lett., 81, p. 1102Hirota, K., Moritomo, Y., Fujioka, H., Kubota, M., Yoshizawa, H., Endoh, Y., (1998) J. Phys. Soc. Jpn., 67, p. 3380Li, J.Q., Matsui, Y., Kimura, T., Tokura, Y., (1998) Phys. Rev. B, 57, pp. R3205Kimura, T., Kumai, R., Tokura, Y., Li, J.Q., Matsui, Y., (1998) Phys. Rev. B, 58, p. 11081Hayashi, T., Miura, N., Tokunaga, M., Kimura, T., Tokura, Y., (1998) J. Phys.: Condens. Matter, 10, p. 11525Suryanarayanan, R., Dhalenne, G., Revcolevschi, A., Prellier, W., Renard, J.P., Dupas, C., Caliebe, W., Chatterji, T., (2000) Solid State Commun., 113, p. 267Kubota, M., Fujioka, H., Ohoyama, K., Hirota, K., Moritomo, Y., Yoshizawa, H., Endoh, Y., (1999) J. Phys. Chem. Solids, 60, p. 116Bhagat, S.M., Lofland, S.E., Mitchell, J.F., (1999) Phys. Lett. A, 259, p. 326Kittel, C., (1997) Introduction to Solid State Physics, , Wiley, New YorkOkochi, M., (1970) J. Phys. Soc. Jpn., 28, p. 897Victoria, C., Barker, R.C., Yelon, A., (1967) Phys. Rev. Lett., 19, p. 792Nagata, K., (1976) J. Phys. Soc. Jpn., 40, p. 1209Nagata, K., Yamamoto, I., Takano, H., Yokozawa, Y., (1977) J. Phys. Soc. Jpn., 43, p. 857. , and references thereinHuber, D.L., Seehra, M.S., (1976) Phys. Status Solidi B, 74, p. 145Stanger, J.-L., Andre, J.-J., Turek, P., Hosokoshi, Y., Tamura, M., Kinoshita, M., Rey, P., Veciana, J., (1997) Phys. Rev. B, 55, p. 8398Van Vleck, J.H., (1950) Phys. Rev., 78, p. 266Kittel, C., (1948) Phys. Rev., 73, p. 15

    Elastic Tensor of Sr2_2RuO4_4

    Full text link
    The six independent elastic constants of Sr2_2RuO4_4 were determined using resonant ultrasound spectroscopy on a high-quality single-crystal specimen. The constants are in excellent agreement with those obtained from pulse-echo experiments performed on a sample cut from the same ingot. A calculation of the Debye temperature using the measured constants agrees well with values obtained from both specific heat and M\"{o}ssbauer measurements.Comment: 4 pages, 2 figures, 2 tables, submitted to PR

    Phase Formation and Evolution in Mg(OH)(2)-Zeolite Cements

    Get PDF
    The mineralogy and structure of cements in the system Mg(OH)2–NaAlO2–SiO2–H2O are investigated, with a view toward potential application in the immobilization of Mg(OH)2-rich Magnox sludges resulting from historic United Kingdom nuclear operations. The reaction process leading to the formation of these aluminosilicate binders is strongly exothermic, initially forming zeolite NaA (LTA structure), which is metastable in low SiO2/Al2O3 binders, slowly evolving into the more stable sodalite and faujasite framework types. Notable chemical reaction of Mg(OH)2 was only identified in the formulation with SiO2/Al2O3 = 1.3 (the lowest molar ratio among those tested) after extended curing times. In this case, some of the Mg(OH)2 reacted to form an Mg–Al–OH layered double hydroxide. These results demonstrate that encapsulation of Magnox sludge waste streams could be carried out in these alternative binders but that the binders would encapsulate rather than chemically incorporate the Mg(OH)2 into the wasteform unless low SiO2/Al2O3 ratios are used

    Magnetic Structure Of Cerhin5 As A Function Of Pressure And Temperature

    Get PDF
    We report magnetic neutron-diffraction and electrical resistivity studies on single crystals of the heavy-fermion antiferromagnet CeRhIn5 at pressures up to 2.3 GPa. These experiments show that the staggered moment of Ce and the incommensurate magnetic structure change weakly with applied pressure up to 1.63 GPa, where resistivity, specific heat and nuclear quadrupole resonance measurements confirm the presence of bulk superconductivity. This work places important constraints on an interpretation of the relationship between antiferromagnetism and unconventional superconductivity in CeRhIn 5.692244031244036Heffner, R.H., Norman, M.R., (1996) Comments Condens. Matter Phys., 17, p. 361Stewart, G.R., (2001) Rev. Mod. Phys., 73, p. 797Mathur, N.D., Grosche, F.M., Julian, S.R., Walker, I.R., Freye, D.M., Haselwimmer, R.K.W., Lonzarich, G.G., (1998) Nature (London), 394, p. 39Sato, N.K., Aso, N., Miyake, K., Shiina, R., Thalmeier, P., Varelogiannis, G., Geibel, C., Komatsubara, T., (2001) Nature (London), 410, p. 340Fisk, Z., Ott, H.R., Smith, J.L., (1986) Proceedings of the Sixth Annual Conference, , Los Alamos, NM, USA, (unpublished)Fisk, Z., Hess, D.W., Pethick, C.J., Pines, D., Smith, J.L., Thompson, J.D., Willis, J.O., (1988) Science, 239, p. 4835Miyake, K., Schmitt-Rink, S., Varma, C.M., (1986) Phys. Rev. B, 34, p. 6554Monthoux, P., Balatsky, A.V., Pines, D., (1991) Phys. Rev. Lett., 67, p. 3448Coleman, P., Pepin, C., (2002) Physica B, 312-313, p. 383Walker, I.R., Grosche, F.M., Freye, D.M., Lonzarich, G.G., (1997) Physica C, 282-287, p. 303Morin, P., Vettier, C., Flouquet, J., Konczykowski, M., Lassailly, Y., Mignot, J.M., Welp, U., (1988) J. Low Temp. Phys., 70, p. 377Jaccard, D., Wilhelm, H., Alami-Yadri, K., Vargoz, E., (1999) Physica B, 259-261, p. 1Jaccard, D., Behnia, K., Sierro, J., (1992) Phys. Lett. A, 163, p. 475Thompson, J.D., Parks, R.D., Borges, H., (1986) J. Magn. Magn. Mater., 54-57, p. 377Grosche, F.M., Julian, S.R., Mathur, N.D., Lonzarich, G.G., (1996) Physica B, 223-224, p. 50Movshovich, R., Graf, T., Mandrus, D., Thompson, J.D., Smith, J.L., Fisk, Z., (1996) Phys. Rev. B, 53, p. 8241Petrovic, C., Moshopoulou, E.G., Hundley, M.F., Sarrao, J.L., Fisk, Z., Thompson, J.D., (2000) Phys. Rev. Lett., 84, p. 4986Petrovic, C., Movshovich, R., Jaime, M., Pagliuso, P.G., Hundley, M.F., Sarrao, J.L., Fisk, Z., Thompson, J.D., (2001) Europhys. Lett., 53, p. 354Petrovic, C., Pagliuso, P.G., Hundley, M.F., Movshovich, R., Sarrao, J.L., Thompson, J.D., Fisk, Z., Monthoux, P., (2001) J. Phys.: Condens. Matter, 13, pp. L337Zheng, G.-Q., Tanabe, K., Mito, T., Kawasaki, S., Kitaoka, Y., Aoki, D., Haga, Y., Onuki, Y., (2001) Phys. Rev. Lett., 86, p. 4664Movshovich, R., Jaime, M., Thompson, J.D., Petrovic, C., Fisk, Z., Pagliuso, P.G., Sarrao, J.L., (2001) Phys. Rev. Lett., 86, p. 5152Fisher, R.A., Bouquet, F., Phillips, N.E., Hundley, M.F., Pagliuso, P.G., Sarrao, J.L., Fisk, Z., Thompson, J.D., (2002) Phys. Rev. B, 65, p. 224509Kawasaki, S., Mito, T., Kawasaki, Y., Zheng, G.-Q., Kitaoka, Y., Aoki, D., Haga, Y., Onuki, Y., cond-mat/0303123 (unpublished)Mito, T., Kawasaki, S., Zheng, G.-Q., Kawasaki, Y., Ishida, K., Kitaoka, Y., Aoki, D., Onuki, Y., (2001) Phys. Rev. B, 63, p. 220507Mito, T., Kawasaki, S., Zheng, G.-Q., Kawasaki, Y., Ishida, K., Kitaoka, Y., Aoki, D., Onuki, Y., (2002) Physica B, 312-313, p. 16Izawa, K., Yamaguchi, H., Matsuda, Y., Shishido, H., Settai, R., Onuki, Y., (2001) Phys. Rev. Lett., 87, p. 057002Pagliuso, P.G., Petrovic, C., Movshovich, R., Hall, D., Hundley, M.F., Sarrao, J.L., Thompson, J.D., Fisk, Z., (2001) Phys. Rev. B, 64, p. 100503Zapf, V.S., Freeman, E.J., Bauer, E.D., Petricka, J., Sirvent, C., Frederick, N.A., Dickey, R.P., Maple, M.B., (2002) Phys. Rev. B, 65, p. 014506Moshopoulou, E.G., Fisk, Z., Sarrao, J.L., Thompson, J.D., (2001) J. Solid State Chem., 158, p. 25Curro, N.J., Hammel, P.C., Pagliuso, P.G., Sarrao, J.L., Thompson, J.D., Fisk, Z., (2000) Phys. Rev. B, 62, pp. R6100Bao, W., Pagliuso, P.G., Sarrao, J.L., Thompson, J.D., Fisk, Z., Lynn, J.W., Erwin, R.W., (2000) Phys. Rev. B, 62, p. 14621(2003) Phys. Rev. B, 67, pp. 099903EMito, T., Kawasaki, S., Kawasaki, Y., Zheng, G.-Q., Kitaoka, Y., Aoki, D., Haga, Y., Onuki, Y., (2003) Phys. Rev. Lett., 90, p. 077004Bao, W., Trevino, S.F., Lynn, J.W., Pagliuso, P.G., Sarrao, J.L., Thompson, J.D., Fisk, Z., (2002) Appl. Phys. A Mater. Sci. Process. A, 74, p. 557Majumdar, S., Balakrishnan, G., Lees, M.R., Paul, D.McK., McIntyre, G.J., (2002) Phys. Rev. B, 66, p. 212502Kawasaki, S., (2002) Phys. Rev. B, 65, p. 020504Shishido, H., Settai, R., Araki, S., Ueda, T., Inada, Y., Kobayashi, T.C., Muramatsu, T., Onuki, Y., (2002) Phys. Rev. B, 66, p. 214510Kumar, R.S., Kohlmonn, H., Light, B.E., Cornelius, A.L., Raghavan, V., Darling, T.W., Sarrao, J.L., cond-mat/0209005 (unpublished)Moshopoulou, E.G., Fisk, Z., Sarrao, J.L., Thompson, J.D., (2001) J. Solid State Chem., 25, p. 158Pagliuso, P.G., Petrovic, C., Movshovich, R., Hall, D., Hundley, M.F., Sarrao, J.L., Thompson, J.D., Fisk, Z., (2001) Phys. Rev. B, 64, p. 100503Thompson, J.D., (1984) Rev. Sci. Instrum., 55, p. 231Bao, W., Aeppli, G., Lynn, J.W., Pagliuso, P.G., Sarrao, J.L., Hundley, M.F., Thompson, J.D., Fisk, Z., (2002) Phys. Rev. B, 65, p. 100505Cooper, M.J., (1968) Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr., A6, p. 624Cooper, M.J., Nathans, R., (1968) Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr., A6, p. 619Mignot, J.-M., Bourdarot, F., Llobet, A., Abanov, Ar., private communicationBlume, M., Freeman, A.J., Watson, R.E., (1962) J. Chem. Phys., 37, p. 1245Christianson, A.D., Lawrence, J.M., Pagliuso, R.G., Moreno, N.O., Sarrao, J.L., Thompson, J.D., Riseborough, P.S., Lacerda, A.H., (2002) Phys. Rev. B, 66, p. 193102Curro, N.J., Sarrao, J.L., Thompson, J.D., Pagliuso, P.G., Kos, S., Abanov, Ar., Pines, D., (2003) Phys. Rev. Lett., 90, p. 227202Knebel, G., Braithwaite, D., Canfield, P.C., Lapertot, G., Flouquet, J., (2002) High Press. Res., 22, p. 16

    Isolation of elusive HAsAsH in a crystalline diuranium(IV) complex

    Get PDF
    The HAsAsH molecule has hitherto only been proposed tentatively as a short-lived species generated in electrochemical or microwave-plasma experiments. After two centuries of inconclusive or disproven claims of HAsAsH formation in the condensed phase, we report the isolation and structural authentication of HAsAsH in the diuranium(IV) complex [{U(TrenTIPS)}2(μ-η2:η2-As2H2)] (3, TrenTIPS=N(CH2CH2NSiPri3)3; Pri=CH(CH3)2). Complex 3 was prepared by deprotonation and oxidative homocoupling of an arsenide precursor. Characterization and computational data are consistent with back-bonding-type interactions from uranium to the HAsAsH π*-orbital. This experimentally confirms the theoretically predicted excellent π-acceptor character of HAsAsH, and is tantamount to full reduction to the diarsane-1,2-diide form
    • …
    corecore