Metody statystyczne w ocenie zmian zawartości bromków w solankach uzdrowiska Goczałkowice-Zdrój

Trends in the groundwater quality can be assessed with statistical methods such as the linear model, the fixed effect model and the robust statistic. The paper shows the assessment of trend on the example of bromides in the region of Goczałkowice- Zdrój health resort. Analyses were based on the data from the years 1977– 2014 from two boreholes: GN-1, GN-2. Results indicate a decrease trend of bromides concentration

NUMERICAL MODEL FOR DENDRITE GROWTH - AN APPLICATION OF THE RANK CONTROLLED DIFFERENTIAL QUADRATURE METHOD

Rank Controlled Differential Quadrature (RCDQ) is an innovative method for numerical approximation of problems described by Partial Differential Equations (PDEs). In this paper the authors apply the RCDQ for the numerical simulation of a simplified model for dendrite growth during Al-Ti alloy crystallization. The authors put most concern on building an accurate numerical model for this phenomenon. In the simplified model the symmetry and flux on boundary condition appears. Additionally, dendrite tip growth into adjacent liquid change the computation domain size, what indicates a need for node coordinate recalculation during each new time step. The authors analyze the results of numerical modelling of alloying element concentration and dendrite growth rate. The modelling results shows that the RCDQ method can be used for modelling problems with moving grid and that the method approximation proposed by the authors is proper

EXTENDED FREE SURFACE FLOW MODEL BASED ON THE LATTICE BOLTZMANN APPROACH

The aim of this work was to extend numerical model of mould filling phenomena previously presented in [3]. Authors described some techniques for modeling single phase and free surface flows. Method, called "piston model", for modeling influence of liquid flow on gas behavior inside the mould and also, effect of local gas pressure on movement of metal free surface, was shown. In last part of this work, results from presented model were compared with data from the commercial simulation environment FLOW-3D

STATISTICAL ANALYSIS OF SiC ADDITION ON HETEROGENEOUS NUCLEATION OF α-Mg PRIMARY PHASE IN THE AZ91/SiC COMPOSITE

The aim of this research was to compare influence of different SiC mass fraction and different SiC particle size on the nucleation process of magnesium primary phase in AZ91/SiC composite. This paper presents experimental results using SiC particles as a reinforcement for AZ91 alloy and their influence on both the grain size of α-Mg primary phase and dimensional homogeneity of grains of this phase. This study provides a good basis for optimizing the process of preparing the AZ91/SiC composite

MODEL OF DENDRITE GROWTH IN METALLIC ALLOYS

The aim of this study was to develop a model of dendrite growth. The model should emphasis on solute depletion around dendrite tip and its influence on dendrite growth rate. Prepared model can be used to predict dendrite growth rate in metallic alloy. It was assumed that dendrite while growing occupy a spherical envelope with radius R that consists of solid dendrite and interdendritic melt enclosed by dendrite arms. Set of differential equations that built the model can be solved with numerical methods. The solution allows determination of dendrite growth rate and alloy component distribution in the liquid adjected to the dendrite and inside the solid dendrite