A case in favor of the N∗(1700)(3/2−)N^*(1700)(3/2^-)

Using an interaction extracted from the local hidden gauge Lagrangians, which brings together vector and pseudoscalar mesons, and the coupled channels $\rho N$ (s-wave), $\pi N$ (d-wave), $\pi \Delta$ (s-wave) and $\pi \Delta$ (d-wave), we look in the region of $\sqrt s =1400-1850$ MeV and we find two resonances dynamically generated by the interaction of these channels, which are naturally associated to the $N^*(1520) (3/2^-)$ and $N^*(1700) (3/2^-)$. The $N^*(1700) (3/2^-)$ appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the $\pi N$ (d-wave) data. Both the real and imaginary parts of the $\pi N$ amplitude vanish in our approach in the vicinity of this resonance, similarly to what happens in experimental determinations, what makes this signal very weak in this channel. This feature could explain why this resonance does not show up in some experimental analyses, but the situation is analogous to that of the $f_0(980)$ resonance, the second scalar meson after the $\sigma (f_0(500))$ in the $\pi \pi$(d-wave) amplitude. The unitary coupled channel approach followed here, in connection with the experimental data, leads automatically to a pole in the 1700 MeV region and makes this second $3/2^-$ resonance unavoidable

Predicted electric field near small superconducting ellipsoids

We predict the existence of large electric fields near the surface of superconducting bodies of ellipsoidal shape of dimensions comparable to the penetration depth. The electric field is quadrupolar in nature with significant corrections from higher order multipoles. Prolate (oblate) superconducting ellipsoids are predicted to exhibit fields consistent with negative (positive) quadrupole moments, reflecting the fundamental charge asymmetry of matter.Comment: To be published in Phys.Rev.Let

Flash Point and Chemical Composition of Aviation Kerosene (Jet A)

The relationship between chemical composition, flash point, and ignition energy was examined for eight samples of aviation kerosene (Jet A) with flash points between 29°C (84°F) and 74°C (165°F). We report the results of liquid characterization by two different laboratories. We use the results of headspace gas chromatography carried out by Woodrow and Seiber to characterize the vapor composition at liquid mass loading fractions of 3 and 400 kg/m^3. The composition data were analyzed to obtain analytical representations of vapor pressure and average molar mass as a function of temperature for each flash point fuel. The relationship between composition and flash point is examined by using two prediction methods. The first method is based on the notion of a critical value of fuel-air mass ratio at the flammability limit. The second method is based on Le Chatelier's rule for flammability limits. Both methods show a reasonable correlation between measured and predicted flash point. The relationship between flash point and ignition temperature threshold at a fixed spark ignition energy was examined for four fuels. A linear correlation was obtained for an ignition energy of 0.3 J. The effect of fuel weathering was examined by determining the flashpoints of seven fuel samples obtained from flight tests. The flash point increased about 8°C for fuel that had been exposed to 5 take-off, cruise, and landing cycles

A Study of the Biology of \u3ci\u3eRhopalosiphum Padi\u3c/i\u3e (Homoptera: Aphididae) in Winter Wheat in Northwestern Indiana

Periodic collections of the bird cherry-oat aphid, Rhopalosiphum padi, during two years revealed small populations on winter wheat in Lafayette, Indiana. The greatest numbers were found on volunteer wheat plants before planting. In the autumn, aphids were detected on one-shoot plants by mid-October and also early March. The populations remained small until mid-June. We conclude that the aphid feeding did not significantly affect the plants, but helped spread barley yellow dwarf virus

Self-tuning of cosmological constant and exit from inflation

I review the recent 5D self-tuning solutions of the cosmological constant problem, and try to unify two cosmological constant problems within the framework of the self-tuning solutions. One problem, the large cosmological constant needed for inflation, is interpreted by starting with the parameters allowing only the dS vacuum, and the vanishing cosmological constant at a true vacuum is realized by changing parameters by exit from inflation at the brane such that the self-tuning solution is allowed.Comment: Latex file of 8 pages, including 2 figures. Talk presented at COSPA-03, Taipei, Taiwan, Nov. 13-15, 200

Processing and Microstructure of WC-CO Cermets by Laser Engineering Net Shaping

Submicron-sized tungsten carbide-cobalt (WC-Co) powder and nanostructured WC-Co powder were applied to make thick wall samples by the Laser Engineered Net Shaping (LENS®) process. It was found that decomposition and decarburization of WC was limited during laser deposition because of the features of the LENS® process: high cooling rate, short heating time, and low oxygen concentration. The effects of working distance, as well as laser power, powder feed rate, and traverse speed on microstructure were studied in this paper. Thermal behavior leading to the observed microstructures that result from the variations in the processing parameters was investigated in detailMechanical Engineerin