The objective of this study was to determine the variables that predicted serve efficacy in elite men's volleyball, in sets with different quality of opposition. 3292 serve actions were analysed, of which 2254 were carried out in high quality of opposition sets and 1038 actions were in low quality of opposition sets, corresponding to a total of 24 matches played during the Men's European Volley...

Abstract We detail the design of a variable energy, x-ray fluorescence source using low activity (1.8×10 6 dpm) 99 Tc β that irradiates thin foils. By rotating among foils Ti, Zn, Nb, Ag, and Au, device produces x rays between 4 70 keV at rate near 1 Hz. When is placed in storage position, external radiation non-detectable. The shielding rotation mechanism permits use vacuum liquid nitrogen tem...

Nano-crystalline particles of CeO2 have been synthesized by a low temperature chemical precipitation method. The precursor materials used in this research were Ce(NO3)3.6H2O, NaOH and diethylene glycol as surfactant. X-ray powder diffraction results showed that face centered cubic CeO2 nanoparticles with crystalline size in nanometer scale were formed. Scanning electron microscopy measurement s...

We present the detection of a radio-emitting jet from the black-hole candidate and X-ray binary source Cygnus X-1. Evidence of a bright core with a slightly extended structure was found on milliarcsecond resolution observations with the VLBA at 15.4 GHz. Later observations with the VLBA (and including the phased up VLA) at 8.4 GHz show an extended jet-like feature extending to ∼ 15 mas from a c...

In this paper we propose three different VNS variants to solve the Max-Mean Dispersion Problem. This problem consists of selecting a set of elements in such a way that the average distance between them is maximized. To tackle this problem, we propose a Basic Variable Neighborhood Search (BVNS), a Variable Neighborhood Descent (VND) and a Generalized Variable Neighborhood Search (GVNS) that hybr...

We show with a short Chandra HRC-S exposure that the powerful X-ray source coincident with the nucleus of M33 is unresolved at the highest spatial resolution available to date (0. ′′ 4). The source flux is variable, doubling during the 5 ks exposure. The combination of properties exhibited by M33 X-8 establishes the source as the nearest example of the ultra-luminous X-ray sources that have bee...

This research program centers around a two-spectrometer x-ray diffuse-scattering system based on a Rigaku 12-kW rotating-anode x-ray generator. The apparatus is designed in such a way that one may easily tailor the instrumental resolution function to optimize studies of structure and fluctuations in a vast range of physical systems. Angular resolution of 1.8 seconds of arc and sample temperatur...