A two-stage pneumatic repeating pellet injector for refueling magnetically confined plasmas in long-pulse fusion experiments

An experiment to demonstrate the feasibility of a repetitive pneumatic pellet injector at 1 Hz in the velocity range of 2 to 3 knVs was carried out in a collaboration between Oak Ridge National Laboratory and ENEA Frascati, in the context of a cooperative agreement between the US Department of Energy and EURATOM-ENEA Association. The third round of this experiment was completed in May 1995. Both the operation and performance of the equipment were improved, and the original objectives of the collaboration have been met. The facility was also briefly operated with neon pellets to explore the potential for producing fast ``killer`` pellets for disruption amelioration applications. Speeds of 1.7 km/s were achieved using a piston mass of 43 g. Higher speeds should be achievable with a system specifically designed for neon or other higher Z gases. Finally, tests were performed with thin boron carbide coatings (2 {mu}m) on the Ergal pistons. The test results were encouraging because piston friction was reduced was the piston wear

Modeling hydrologic data by means of re-parametrization of Beta-Singh-Maddala distribution

In this paper we propose a new parametrization of the four-parameters Beta-Singh-Maddala distribution suitable for the context of hydrologic studies. With this aim, we reparameterize the Beta-Singh-Maddala distribution to make its parameters directly interpretable in terms of measures much more relevant for their practical use than the classical shape, location and scale parameters of the parametric families generally used for modeling hydrologic events. Moreover, in order to evaluate how climatic or physic characteristics could affect these measures, we will express them as functions of a set of covariates that could have an effect separately and/or simultaneously

Copula-based properties of the bivariate Dagum distribution

The Dagum distribution plays an important role both in statistical theory and in economics as a model for income distribution. The main goal of this paper was to develop a bivariate extension of the Dagum distribution and study its distributional properties. Also we will study its dependence properties using copula function. Also we derive the cumulative distribution function and probability density function of the maximum and minimum of the bivariate Dagum order statistics. We estimate the parameters of the distribution and demonstrate it on a real data example. © 2018, SBMAC - Sociedade Brasileira de Matemática Aplicada e Computacional

Some developments on the log-Dagum distribution

Skewness, Kurtosis, ML estimates, Fisher information matrix, Value-at-Risk, 60E05 (Primary), 62F12 (Secondary),