XB-70 flight test data comparisons with simulation predictions of inlet unstart and buzz

XB-70 flight test data comparison with simulated predictions of inlet unstart and buz

Deposition and characterization of ZnS/Si heterojunctions produced by vacuum evaporation

Isotype heterojunctions of ZnS (lattice constant 5.41 A) were grown on silicon (lattice constant 5.43 A) p-n junctions to form a minority-carrier mirror. The deposition process was vacuum evaporation from a ZnS powder source onto a heated (450 C) substrate. Both planar (100) and textured (111) surfaces were used. A reduction of the minority-carrier recombination at the surface was seen from increased short-wavelength quantum response and increased illuminated open-circuit voltage. The minority-carrier diffusion length was not degraded by the process

Efficient analysis in planet transit surveys

With the growing number of projects dedicated to the search for extrasolar planets via transits, there is a need to develop fast, automatic, robust methods with a statistical background in order to efficiently do the analysis. We propose a modified analysis of variance (AoV) test particularly suitable for the detection of planetary transits in stellar light curves. We show how savings of labor by a factor of over 10 could be achieved by the careful organization of computations. Basing on solid analytical statistical formulation, we discuss performance of our and other methods for different signal-to-noise and number of observations.Comment: 7 pages, to be published in MNRAS, downloadable software from http://www.camk.edu.pl/~alex/#softwar

Oxalic Acid Production by Sclerotinia homoeocarpa: the Causal Agent of Dollar Spot

Oxalic acid production by Sclerotinia homoeocarpaFungi in the genus Sclerotinia include some of the most devastating pathogens known. Dollar spot, caused by S. homoeocarpa, is the most prevalent and sprayed for disease of golf course turf. The production of oxalic acid and pectolytic cell wall-degrading enzymes by species within this genus is well documented. A series of laboratory-based assays were used to determine whether S. homoeocarpa produces oxalic acid. Potato dextrose agar (PDA) adjusted to pH 4 and pH 6, with and without bromophenol blue (Bb), was used to assess the growth of and acid production by S. homoeocarpa between 5-35 C. When added to PDA, Bb only slightly hindered the growth of S. homoeocarpa. Acid production by S. homoeocarpa on PDA + Bb occurred between 15-30 C at both pHs, but was first observed on media adjusted to pH 6. Maximum acid production occurred between 20-30 C. Acid production by S. homoeocarpa was also observed when grown in potato dextrose broth (PDB) at 25 C. High Performance Liquid Chromatography analysis of spent culture broth collected from S. homoeocarpa inoculated PDB revealed the presence of oxalic acid.Department of Plant Pathology, The Ohio State Universit

Anisotropic scaling of remotely sensed drainage basins: the differential anisotropy scaling technique

International audienceWe investigate the statistical properties of dendritic drainage areas from diverse geological environments (Deception Canyon, Utah and the Loess Plateau, China) using narrow band visible ASTER satellite images. We show that from 240 m to 7680 m, the isotropic (angle integrated) energy spectra E(k) of all the fields closely follow a power law form: E(k)?k?? where k is a wave number and ? a scale invariant exponent. In spite of this good isotropic scaling, images with very similar ?'s and similar isotropic multifractal exponents have distinct textures; we suggest that the differences are primarily due to anisotropy, which is nevertheless scaling. We develop the new "Differential Anisotropy Scaling" technique to characterize this scale-by-scale (differential) anisotropy and we test it on simulated anisotropic scaling fields. The method gives useful characterizations of the scale by scale anisotropy irrespective of whether or not the analyzed field is scaling. When the anisotropy is not too strong, the parameters can be interpreted as scale invariant anisotropy exponents. Viewed as a method of estimating these exponents, it has the advantage of relying on two linear regressions rather than on complex higher dimensional nonlinear ones. When applied to dendritic drainage basins we find that they have distinct anisotropies characterized by differential anisotropy stretching and rotation parameters as well as by a distinct absolute anisotropy at the reference scale of 960 m. Our new method allows us to statistically distinguish, not only between two geologically different drainage basins (the China Loess Plateau and Utah Deception Canyon), but also between different regions of the same China drainage system