Effect of chemical treatments on physico-chemical properties of fibres from banana fruit and bunch stems

Fibres have been extracted from fruit and bunch stems of banana plant by water retting and evaluated in terms of their performance characteristics. Banana bunch stem fibres have been found to be superior in terms of fineness, initial modulus and breaking strength, whereas elongation ratio shows an inverse trend. Thus, they have been further treated by bleaching and alkalization. Among the treated fibres, the bleached fibres show the highest initial modulus, breaking tenacity, and the lowest elongation. Alkalization results in increased breaking elongation and decreased initial modulus, whiteness and water absorption. The bunch stem fibres present higher water absorptive capacity and lower whiteness compared to that of fruit stem fibres. The characteristics of these unconventional fibres have been found to be comparable to natural fibres traditionally used in textiles. The ranges for properties of the studied banana fruit and bunch stem fibres in general can be given as: linear density 12.71-20.38 tex, initial moduli 168 -326 cN/tex, breaking tenacity 9.89-13.3 cN/tex, breaking elongation 4.42-16.4%, and moisture content 11.6-15.8%

Modulating the catalytic activity of enzyme-like nanoparticles through their surface functionalization

The inclusion of transition metal catalysts into nanoparticle scaffolds permits the creation of catalytic nanosystems (nanozymes) able to imitate the behaviour of natural enzymes. Here we report the fabrication of a family of nanozymes comprised of bioorthogonal ruthenium catalysts inserted in the protective monolayer of gold nanoparticles. By introducing simple modifications to the functional groups at the surface of the nanozymes, we have demonstrated control over the kinetic mechanism of our system. Cationic nanozymes with hydrophobic surface functionalities tend to replicate the classical Michaelis Menten model, while those with polar groups display substrate inhibition behaviour, a key mechanism present in 20% of natural enzymes. The structural parameters described herein can be used for creating artificial nanosystems that mimic the complexity observed in cell machinery. © 2018 The Royal Society of Chemistry

Indications of Neutrino Oscillation in a 250 km Long-baseline Experiment

The K2K experiment observes indications of neutrino oscillation: a reduction of $\nu_\mu$ flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of $80.1^{+6.2}_{-5.4}$. Twenty-nine one ring $\mu$-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.Comment: 5 pages, 3 figures embedded, LaTeX with RevTeX style, accepted for publication in PRL on December 13, 200

Measurement of single pi0 production in neutral current neutrino interactions with water by a 1.3 GeV wide band muon neutrino beam

Neutral current single pi0 production induced by neutrinos with a mean energy of 1.3 GeV is measured at a 1000 ton water Cherenkov detector as a near detector of the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064 +- 0.001 (stat.) +- 0.007 (sys.). The momentum distribution of produced pi0s is measured and is found to be in good agreement with an expectation from the present knowledge of the neutrino cross sections.Comment: 6 pages, 4 figures, Submitted to Phys. Lett.

Study of Non-Standard Neutrino Interactions with Atmospheric Neutrino Data in Super-Kamiokande I and II

In this paper we study non-standard neutrino interactions as an example of physics beyond the standard model using atmospheric neutrino data collected during the Super-Kamiokande I(1996-2001) and II(2003-2005) periods. We focus on flavor-changing-neutral-currents (FCNC), which allow neutrino flavor transitions via neutral current interactions, and effects which violate lepton non-universality (NU) and give rise to different neutral-current interaction-amplitudes for different neutrino flavors. We obtain a limit on the FCNC coupling parameter, varepsilon_{mu tau}, |varepsilon_{mu tau}|<1.1 x 10^{-2} at 90%C.L. and various constraints on other FCNC parameters as a function of the NU coupling, varepsilon_{e e}. We find no evidence of non-standard neutrino interactions in the Super-Kamiokande atmospheric data.Comment: 12 Pages, 14 figures. To be submitted to Phys. Rev.

Calibration of Super-Kamiokande Using an Electron Linac

In order to calibrate the Super-Kamiokande experiment for solar neutrino measurements, a linear accelerator (LINAC) for electrons was installed at the detector. LINAC data were taken at various positions in the detector volume, tracking the detector response in the variables relevant to solar neutrino analysis. In particular, the absolute energy scale is now known with less than 1 percent uncertainty.Comment: 24 pages, 16 figures, Submitted to NIM

Evidence for the Appearance of Atmospheric Tau Neutrinos in Super-Kamiokande

Super-Kamiokande atmospheric neutrino data were fit with an unbinned maximum likelihood method to search for the appearance of tau leptons resulting from the interactions of oscillation-generated tau neutrinos in the detector. Relative to the expectation of unity, the tau normalization is found to be 1.42 \pm 0.35 \ (stat) {\}^{+0.14}_{-0.12}\ (syst) excluding the no-tau-appearance hypothesis, for which the normalization would be zero, at the 3.8$\sigma$ level. We estimate that 180.1 \pm 44.3\ (stat) {\}^{+17.8}_{-15.2}\ (syst) tau leptons were produced in the 22.5 kton fiducial volume of the detector by tau neutrinos during the 2806 day running period. In future analyses, this large sample of selected tau events will allow the study of charged current tau neutrino interaction physics with oscillation produced tau neutrinos.Comment: 7 pages, 4 figures. This is the version as published in Physical Review Letters including the supplemental figure. A typographical error in the description of figure 3 is also correcte

Search for Differences in Oscillation Parameters for Atmospheric Neutrinos and Antineutrinos at Super-Kamiokande

We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande -I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best fit antineutrino mixing is found to be at (dm2bar, sin2 2 thetabar) = (2.0x10^-3 eV^2, 1.0) and is consistent with the overall Super-K measurement.Comment: 6 pages, 4 figures. Figure update