Hot wire anemometer measurements in the unheated air flow tests of the SRB nozzle-to-case joint

Hot-Wire Anemometer measurements made in the Solid Rocket Booster (SRB) nozzle-to-case joint are discussed. The study was undertaken to glean additional information on the circumferential flow induced in the SRB nozzle joint and the effect of this flow on the insulation bonding flaws. The tests were conducted on a full-scale, 2-D representation of a 65-in long segment of the SRB nozzle joint, with unheated air as the working fluid. Both the flight Mach number and Reynolds number were matched simultaneously and different pressure gradients imposed along the joint face were investigated. Hot-wire anemometers were used to obtain velocity data for different joint gaps and debond configurations. The procedure adopted for hot-wire calibration and use is outlined and the results from the tests summarized

Levy statistical fluctuations from a Random Amplifying Medium

We report the studies of emission from a novel random amplifying medium that we term a ``Levy Laser'' due to the non-Gaussian statistical nature of its emission over the ensemble of random realizations. It is observed that the amplification is dominated by certain improbable events that are ``larger than rare'', which give the intensity statistics a Levy like ``fat tail''. This, to the best of our knowledge, provides the first experimental realization of Levy flight in optics in a random amplifying medium.Comment: 22 pages, 14 figures (postscript format

Radiative capture of polarized neutrons by polarized protons

A model-independent irreducible tensor approach to p(n,gamma)d is presented and an explicit form for the spin-structure of the matrix for the reaction is obtained in terms of the Pauli spin-matrices for the neutron and the proton. Expressing the multipole amplitudes in terms of the triplet --> triplet and singlet --> triplet transitions, we point out how the initial singlet and triplet contributions to the differential cross section can be determined empirically.Comment: Revised version; typeset using RevTeX4; 6 pages, no figure

Climate change as a communication challenge (CCCC). In: Winter School on Impact of Climate Change on Indian Marine Fisheries held at CMFRI, Cochin 18.1.2008 to 7.2.2008

Climate change (CC) science has come a long way in understanding the fundamentals of global warming. There is no doubt anymore in the mainstream scientific community that the Earth is warming, and increasing evidence shows that humans have a significant part in it. (IPCC 2007; Hansen et al, 2007; Dutt and Gaioli, 2007). We do knowthat certain gases, such as carbon dioxide and methane, play a crucial role in determining the Earth’s climate by preventing heat from escaping the atmosphere. Researchers have also been able to document that the increased concentration of such gases in the atmosphere results from human activities such as the burning of fossil fuels, deforestation and land degradation, cattle ranching, and rice farming. The fingerprint of humans causing, at least in part, the global warming we now experience, has been documented in a growing number of studies

Phase ambiguity of the threshold amplitude in pp -> pp\pi^0

Measurements of spin observables in pp -> {\vec p}{\vec p}\pi^0 are suggested to remove the phase ambiguity of the threshold amplitude. The suggested measurements complement the IUCF data on {\vec p}{\vec p} -> pp\pi^0 to completely determine all the twelve partial wave amplitudes, taken into consideration by Mayer et.al. [15] and Deepak, Haidenbauer and Hanhart [20].Comment: 4 pages, 1 table

X-ray topographs of diamond

This article does not have an abstract

Fluctuations of light intensity in coron Æ formed by diffraction

The fluctuations of light intensity in the diffraction corona produced by a large number of randomly distributed particles are investigated both theoretically and experimentally. The theoretical considerations show that the view put forward by de Haas is inadequate and that really the fluctuations arise owing to the interference of the waves diffracted by all the particles, which gives rise to a large number of sharp images of the source in monochromatic light. In white light, these spots must spread out, and produce radial streaks. These deductions from theory are all borne out by experiment

Introducing a twist in carbon nanotubes

A simple model based on rotational distortion of carbon atoms between adjacent layers running perpendicular to the tube axis, without altering the hexagonal motifs is proposed for constructing coiled carbon nanotubes