Antineutrino Physics at MINOS

We present two new measurements of antineutrino properties based on a data sample corresponding to 3.2×10^(20) protons-on-target, exploiting MINOS' unique ability to distinguish positive and negative muons and thus separate charged current neutrino and antineutrino interactions event-by-event. The first measurement takes advantage of the 6% antineutrino component of the NuMI neutrino beam to measure antineutrino oscillations between the near and far detectors. We observe 42 events at the far detector with an expectation of 58.3±7.6(stat.)±3.6(syst.) assuming CPT-conserving oscillations, excluding (5.0<Δm(overbar)^2<81)×10^(−3)eV^2 at 90% confidence at maximal mixing. We also present a search for neutrino-antineutrino transitions ν_μ → ν(overbar)_μ, which would result in an excess of antineutrino events in the Far Detector relative to the rate expected from the intrinsic antineutrino component in the neutrino beam. We observe no excess and set a limit of 0.026 on the transition probability at 90% confidence

Search for Lorentz Invariance and CPT Violation with the MINOS Far Detector

We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of 20–510 over the current best limits found by using the MINOS near detector

Improved Measurement of Muon Antineutrino Disappearance in MINOS

We report an improved measurement of ν̅_μ disappearance over a distance of 735 km using the MINOS detectors and the Fermilab Main Injector neutrino beam in a ν̅_μ-enhanced configuration. From a total exposure of 2.95×10^20 protons on target, of which 42% have not been previously analyzed, we make the most precise measurement of Δm̅^2=[2.62_(-0.28)^(+0.31)(stat)±0.09(syst)]×10^(-3)  eV^2 and constrain the ν_μ mixing angle sin^(2)(2θ̅)>0.75 (90% C.L.). These values are in agreement with Δm^2 and sin^(2)(2θ) measured for νμ, removing the tension reported in [ P. Adamson et al. Phys. Rev. Lett. 107 021801 (2011)]

Polyhedral units and network connectivity in calcium aluminosilicate glasses from high-energy x-ray diffraction

Structure factors for Cax/2AlxSi1-xO2 glasses (x=0,0.25,0.5,0.67) extended to a wave vector of magnitude Q= 40 1/A have been obtained by high-energy x-ray diffraction. For the first time, it is possible to resolve the contributions of Si-O, Al-O and Ca-O coordination polyhedra to the experimental atomic pair distribution functions (PDF). It has been found that both Si and Al are four-fold coordinated and so participate in a continuous tetrahedral network at low values of x. The number of network breaking defects in the form of non-bridging oxygens (NBO's) increases slowly with x until x=0.5 (NBO's ~ 10% at x=0.5). By x=0.67 the network breaking defects become significant as evidenced by the significant drop in the average coordination number of Si. By contrast, Al-O tetrahedra remain free of NBO's and fully integrated in the Al/Si-O network for all values of x. Calcium maintains a rather uniform coordination sphere of approximately 5 oxygen atoms for all values of x. The results suggest that not only Si/Al-O tetrahedra but Ca-O polyhedra, too, play a role in determining the glassy structure

Nanostructure of cellulose microfibrils in spruce wood

The structure of cellulose microfibrils in wood is not known in detail, despite the abundance of cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the microfibrils of spruce wood cellulose was investigated using a range of spectroscopic methods coupled to small-angle neutron and wide-angle X-ray scattering. The scattering data were consistent with 24-chain microfibrils and favored a “rectangular” model with both hydrophobic and hydrophilic surfaces exposed. Disorder in chain packing and hydrogen bonding was shown to increase outwards from the microfibril center. The extent of disorder blurred the distinction between the I alpha and I beta allomorphs. Chains at the surface were distinct in conformation, with high levels of conformational disorder at C-6, less intramolecular hydrogen bonding and more outward-directed hydrogen bonding. Axial disorder could be explained in terms of twisting of the microfibrils, with implications for their biosynthesis

Tribological properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere

This work is concerned with the study of the tribologic properties of room temperature fluorinated graphite heat-treated under fluorine atmosphere. The fluorinated compounds all present good intrinsic friction properties (friction coefficient in the range 0.05–0.09). The tribologic performances are optimized if the materials present remaining graphitic domains (influenced by the presence of intercalated fluorinated species) whereas the perfluorinated compounds, where the fluorocarbon layers are corrugated (armchair configuration of the saturated carbon rings) present higher friction coefficients. Raman analyses reveal that the friction process induces severe changes in the materials structure especially the partial re-building of graphitic domains in the case of perfluorinated compounds which explains the improvement of μ during the friction tests for these last materials

Sick leave certification: a unique perspective on frequency and duration of episodes - a complete record of sickness certification in a defined population of employees in Malta

BACKGROUND: In Malta, sickness certificates are needed from the first day of illness, and are issued by family physicians (FPs) either employed by the government primary health care system, self-employed in private practice, or employed by an employer for this purpose alone. The latter system, when applied by the employer, is compulsory. In order to contribute to the debate on the role of the FP in this context, electronic data collected by a group of company-employed FPs was used to study the phenomenon of sickness certification. This database is a complete record of the selected employees' sick leave certification during the study period. METHODS: Data collected by company-employed FPs from a defined population was used: all employees of selected Maltese companies served by a group of FPs. The database included episode-based data from home visits over three years (01/01/1997 – 31/12/1999), by 9 company-appointed FPs regarding 421 employees of five companies. RESULTS: 3015 episodes of sickness absenteeism, with an average duration of 2.9 days, were documented. Employees who did intensive manual work had relatively higher rates. Furthermore, a relatively higher incidence of work injury, sprains and strains, anxiety and depression and low back pain as found in manual workers, and in male workers. This trend was shown to be statistically significant. CONCLUSIONS: The frequency of sick-leave certification in Malta is comparable to that in other European countries, but the average duration of certificates is much less than reported in other studies that generally did not include data on short-term illness and certification. This has important implications on future research in the field. A number of common disorders were found to be significantly more prevalent causes of sickness certification in manual workers, amongst them anxiety and depression