Tornado detector and alarm

Automatic device which attaches to an active television set sounds an audible alarm when a tornado is within 29 km (18miles) of device

SSME single-crystal turbine blade dynamics

A study was performrd to determine the dynamic characteristics of the Space Shuttle Main Engine high pressure fuel turbopump (HPFTP) blades made of single crystal (SC) material. The first and second stage drive turbine blades of HPFTP were examined. The nonrotating natural frequencies were determined experimentally and analytically. The experimental results of the SC second stage blade were used to verify the analytical procedures. The study examined the SC first stage blade natural frequencies with respect to crystal orientation at typical operating conditions. The SC blade dynamic response was predicted to be less than the directionally solidified base. Crystal axis orientation optimization indicated that the third mode interference will exist in any SC orientation

Study of the modulatory effects of the solar wind on galactic cosmic rays

Mathematical model using Monte Carlo method for modulation of galactic protons by solar win

Evidence for massive neutrinos from CMB and lensing observations

We discuss whether massive neutrinos (either active or sterile) can reconcile some of the tensions within cosmological data that have been brought into focus by the recently released {\it Planck} data. We point out that a discrepancy is present when comparing the primary CMB and lensing measurements both from the CMB and galaxy lensing data using CFHTLenS, similar to that which arises when comparing CMB measurements and SZ cluster counts. A consistent picture emerges and including a prior for the cluster constraints and BAOs we find that: for an active neutrino model with 3 degenerate neutrinos, $\sum m_{\nu}= (0.320 \pm 0.081)\,{\rm eV}$, whereas for a sterile neutrino, in addition to 3 neutrinos with a standard hierarchy and $\sum m_{\nu}= 0.06\,{\rm eV}$, $m_{\nu, \, \rm sterile}^{\rm eff}= (0.450 \pm 0.124)\,{\rm eV}$ and $\Delta N_{\rm eff} = 0.45 \pm 0.23$. In both cases there is a significant detection of modification to the neutrino sector from the standard model and in the case of the sterile neutrino it is possible to reconcile the BAO and local $H_0$ measurements. However, a caveat to our result is some internal tension between the CMB and lensing/cluster observations, and the masses are in excess of those estimated from the shape of the matter power spectrum from galaxy surveys.Comment: 5 pages, 3 figures, clarifications added, comparison with WMAP-9 plus high-l added, version accepted in Physical Review Letter

Environmental effects on silicon solar cells

Test results indicate that solder coating cells produces protective or deleterious effect, depending on the environment. Major problem for solder coated cells is in control of solder thickness and uniformity. Problem area for non-solder coated cells is not identified

Constraints on Supersymmetric Models of Hybrid Inflation

We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density fluctuations measured by CMB experiments. While this finding applies to any cosmological scenario involving strings, we consider in particular models of supersymmetric hybrid inflation, which predict n_s >= 0.98, in tension with the CMB data when strings are not included. Using MCMC analysis we constrain the parameter space allowed for F- and D-term inflation. For the F-term model, using minimal supergravity corrections, we find that \log\kappa= -2.34\pm 0.38 and M= (0.518\pm 0.059) * 10^16 GeV. The inclusion of non-minimal supergravity corrections can modify these values somewhat. In the corresponding analysis for D-term inflation, we find \log\kappa= -4.24\pm 0.19 and m_FI= (0.245\pm 0.031) * 10^16 GeV. Under the assumption that these models are correct, these results represent precision measurements of important parameters of a Grand Unified Theory. We consider the possible uncertainties in our measurements and additional constraints on the scenario from the stochastic background of gravitational waves produced by the strings. The best-fitting model predicts a B-mode polarization signal \approx 0.3 \mu K rms peaking at l \approx 1000. This is of comparable amplitude to the expected signal due to gravitational lensing of the adiabatic E-mode signal on these scales.Comment: 21 pages, 16 figure

Warm Inflation with a General Form of the Dissipative Coefficient

We propose and investigate a general form of the dissipative coefficient $\Gamma=C_{\phi}T^{m}/\phi^{m-1}$ in warm inflation. We focus on discussing the strong dissipative processes $r=\Gamma/3H\gg1$ in the thermal state of approximate equilibrium. To this toy model, we give the slow-roll conditions, the amplitude and the index of the power spectrum under the general form of dissipative coefficient. Furthermore, the monomial potential and the hybrid-like potential are analyzed specifically. We conclude that the $m=0,3$ cases are worthy further investigation especially.Comment: 24 pages, no figures, to be published on JCA

What can we say about seed fields for galactic dynamos?

We demonstrate that a quasi-uniform cosmological seed field is a much less suitable seed for a galactic dynamo than has often been believed. The age of the Universe is insufficient for a conventional galactic dynamo to generate a contemporary galactic magnetic field starting from such a seed, accepting conventional estimates for physical quantities. We discuss modifications to the scenario for the evolution of galactic magnetic fields implied by this result. We also consider briefly the implications of a dynamo number that is significantly larger than that given by conventional estimates