The article describes the method of controlling the recovered grade based on measuring the intensity of volume ultrasonic oscillations and Lamb waves covering a fixed distance through the test medium and on a metal plate contacting the test medium at various time points of deliberate motion of ground materials.

The authors suggest a method of determining density of ground ore particles in the pulp periodically after isolating the pulp flow in the vertical part of the measuring vessel based on measuring attenuation change values in Lamb waves covering a fixed distance on a plate contacting the medium under study and high frequency volume ultrasonic oscillations that have come through it within a certain time period.

There are given dependencies of amplitudes of measuring channels based on volume ultrasonic oscillations and surface Lamb waves, size distribution according to solid phase pulp particles for various types of ores under study, a set of curves for determining the recovered grade with regard to various types of ores under study.

Medical information systems could benefit from electronic health records management using openEHR. On the other hand, such a standard adds an additional software layer to the system, which might impact performance. In this article, we present an in-depth comparison of open-source openEHR servers and propose tools for testing them. Load tests for selected opensource servers were prepared using Apache JMeter. Statistics of elapsed time of requests and throughput of each solution were calculated. Results show that open-source openEHR servers significantly differ in performance and stability and prove that load testing should be a crucial part of a development process.