Making of wing models by tangent-milling

Wings whose surfaces arc developable have been milled on a jig-borer at the National Aeronautical Laboratory, Bangalore, employing tangential milling. In this process, the Wing cross-section is approximated by a polygon which can be smoothened by hand-finish. The polygonal approximation itself is such that each side of the polygon is a tangent to the aerofoil. The aerofoil is defined by a finite set of points got from experiments or otherwise. These points are joined smoothly by using Spline approximation to achieve continuity of first and second13; derivatives. The splines and the settings of the jig-borer (for tangential milling) were obtained on the NAL SIRIUS Computer. Each setting of the jig-borer consists of the cutter-height and two turnings of the turnables one about the axis perpendicular to the turntable and the other about a fixed horizontal axis, so that the plane of milling becomes horizontal. The two angles of rotation and the cutter height depend upon the Wing geometry besides some of the machine parameters

Muonless Events in ICAL at INO

The primary physics signal events in the ICAL at INO are the ${\nu}_{\mu}$ charged current (CC) interactions with a well defined muon track. Apart from these events, ICAL can also detect other types of neutrino interactions, i.e. the electron neutrino charged current interactions and the neutral current events. It is possible to have a dataset containing mostly ${\nu}_e$CC events, by imposing appropriate selection cuts on the events. The ${\nu}_{\mu}$ CC and the neutral current events form the background to these events. This study uses the Monte Carlo generated neutrino events, to design the necessary selection cuts to obtain a ${\nu}_e$ CC rich dataset. An optimized set of constraints are developed which balance the need for improving the purity of the sample and having a large enough event sample. Depending on the constraints used, one can obtain a neutrino data sample, with the purity of ${\nu}_e$ events varying between 55% to 70%.Comment: 21 pages, 6 figure

Testing LSND at long-baseline neutrino experiments

Recently it was suggested that two very different mass-squared differences play a role in atmospheric neutrino oscillations. The larger of these also accounts for the LSND result and the smaller of these also drives the solar neutrino oscillations. We consider the predictions of this scheme for long-baseline experiments. We find that high statistics experiments, such as MINOS, can observe a clean signal for this scheme, which is clearly distinguishable from the usual scheme of atmospheric neutrino oscillations driven by a single mass-squared difference.Comment: 13 pages, 3 figure

Non-Zero θ13\theta_{13} and δCP\delta_{CP} in a Neutrino Mass Model with A4A_4 Symmetry

In this paper, we consider a neutrino mass model based on $A_4$ symmetry. The spontaneous symmetry breaking in this model is chosen to obtain tribimaximal mixing in the neutrino sector. We introduce $Z_2 \times Z_2$ invariant perturbations in this model which can give rise to acceptable values of $\theta_{13}$ and $\delta_{CP}$. Perturbation in the charged lepton sector alone can lead to viable values of $\theta_{13}$, but cannot generate $\delta_{CP}$. Perturbation in the neutrino sector alone can lead to acceptable $\theta_{13}$ and maximal CP violation. By adjusting the magnitudes of perturbations in both sectors, it is possible to obtain any value of $\delta_{CP}$.Comment: 16 pages, 3 figure

The need for an early anti-neutrino run of NOvA

The moderately large value of \ty, measured recently by reactor experiments, is very welcome news for the future neutrino experiments. In particular, the \nova experiment, with 3 years each of $\nu$ and \anu runs, will be able to determine the mass hierarchy if one of the following two favourable combinations is true: normal hierarchy with -180^\circ \leq \dcp \leq 0 or inverted hierarchy with 0\leq \dcp \leq 180^\circ. In this report, we study the hierarchy reach of the first 3 years of \nova data. Since \sin^2 2 \tz is measured to be non-maximal, \tz can be either in the lower or higher octant. Pure $\nu$ data is affected by \ty-hierarchy and octant-hierarchy degeneracies, which limit the hierarchy sensitivity of such data. A combination of $\nu$ and \anu data is not subject to these degeneracies and hence has much better hierarchy discrimination capability. We find that, with a 3 year $\nu$ run, hierarchy determination is possible for only two of the four octant-hierarchy combinations. Equal 1.5 year runs in $\nu$ and \anu modes give good hierarchy sensitivity for all the four combinations

Re-examining sin(2beta) and Delta m(d) from evolution of B(d) mesons with decoherence

In the time evolution of neutral meson systems, a perfect quantum coherence is usually assumed. The important quantities of the B(d) system, such as sin (2beta) and Delta m(d), are determined under this assumption. However, the meson system interacts with its environment. This interaction can lead to decoherence in the mesons even before they decay. In our formalism this decoherence is modelled by a single parameter lambda. It is desirable to re-examine the procedures of determination of sin(2beta) and Delta m(d) in meson systems with decoherence. We find that the present values of these two quantities are modulated by lambda. Re-analysis of B(d) data from B-factories and LHCb can lead to a clean determination of lambda, sin(2beta) and Delta m(d).Comment: Version accepted for publication in Physics Letters

Smart Meter Privacy: A Utility-Privacy Framework

End-user privacy in smart meter measurements is a well-known challenge in the smart grid. The solutions offered thus far have been tied to specific technologies such as batteries or assumptions on data usage. Existing solutions have also not quantified the loss of benefit (utility) that results from any such privacy-preserving approach. Using tools from information theory, a new framework is presented that abstracts both the privacy and the utility requirements of smart meter data. This leads to a novel privacy-utility tradeoff problem with minimal assumptions that is tractable. Specifically for a stationary Gaussian Markov model of the electricity load, it is shown that the optimal utility-and-privacy preserving solution requires filtering out frequency components that are low in power, and this approach appears to encompass most of the proposed privacy approaches.Comment: Accepted for publication and presentation at the IEEE SmartGridComm. 201