We report on a BeppoSAX Concentrator Spectrometer observation of the super-soft source (SSS) CAL87. The X-ray emission in SSS is believed to arise from nuclear burning of accreted material on the surface of a white dwarf (WD). An absorbed blackbody spectral model gives a χν of 1.18 and a temperature of 42±13 11 eV. However, the derived luminosity and radius are greater than the Eddington limit ...

We report Hand K ′-band speckle interferometric observations of the HAeBe star V376 Cas. Our observations show that the object is partially resolved. The visibility curves suggest three separate components: a large scattering envelope visible only in the H band, a component approximately 100 mas in radius, and a component with a Gaussian HWHM of approximately 8±3 mas, corresponding to approxima...

Let P ⊂ R be a set of n points, each with an associated radius rp > 0. The transmission graph G for P has vertex set P and a directed edge from p to q if and only if q lies in the ball with radius rp around p. Let t > 1. A t-spanner H for G is a sparse subgraph such that for any two vertices p and q connected by a path of length l in G, there is a path of length at most t · l from p to q in H. ...

The flux penetration near a semicircular indentation at the edge of a thin superconducting strip placed in a transverse magnetic field is investigated. The flux front distortion due to the indentation is calculated numerically by solving the Maxwell equations with a highly nonlinear E j law. We find that the excess penetration can be significantly 50% larger than the indentation radius r0, in c...

This paper represents algorithm for recognition of the coins of different denomination. The proposed system first uses a canny edge detection to generate an edge map, then uses CHT (Circular Hough transform) to recognize the coins and further find the radii of them. Based on the radius of the coin, the coins of different denomination are classified. The experimental result shows that the Hough ...

Diamond coated cutting tools provide several advantages over traditional cutting tools, specifically in the machining of advanced materials such as composites. One of the main disadvantages of diamond coated cutting tools is the residual stresses induced from the diamond deposition, which lead to tool failure. Moreover, the cutting edge geometry can be critical to the deposition residual stress...

We give upper bounds for the spectral radius of a graph with e edges provided that there is no complete graph with e edges. Our bounds are sharp for (i) the complete graphs with one, two, or three edges removed; (ii) the complete graph with one added vertex and edge. Let G be a undirected graph with e edges and without loops. Then G is represented by its adjacency O-l symmetric matrix A with ze...

We consider a random geometric graph constructed by the homogeneous Boolean model with spherical grains in R, d ≥ 2; that is, a node of the graph corresponds to a germ of the Boolean model and there is an edge between two nodes when their grains intersect with each other. We show that, when the radius distribution of grains is long-tailed, so is the degree distribution of the graph. Our result ...