The determination of tolerances has a huge impact on the price and quality of products. The objective of tolerance analysis is to provide the widest possible tolerance range of parts, without disturbing the functionality of the assembly. Tolerance analysis should be performed during the design process because then there is still the possibility for change. For the purpose of carrying out the analysis, three methods will be used: Worst Case method, Root Sum Square method and Monte Carlo Simulation. Methods are explained through simple examples and applied on the one-way clutch.

Due to the factors that affect the results of work on a daily basis, higher education institutions, through their quality assurance systems, or their planning, must assess risks. In doing so, they must take into account all issues of the internal and external context as well as the needs and expectations of all stakeholders in higher education. The paper explains in an appropriate way the concept of risk as well as all the elements that determine it and their classification in the field of higher education. Subsequently, a possible approach to risk management is discussed, with an emphasis on clarifying the principles and the risk management process itself. Finally, the basics of practical application in risk identification, analysis, evaluation and treatment are outlined.

In the paper, a process capability and process performance analyses for continuous and attribute data are conducted by using an industry example. The inner diameter of the bearing rings is analysed by applying the normal capability analysis for the continuous data and by applying the binomial capability analysis for the attribute data. In order to quantify the process performance and process capability for continuous and attribute data, the sigma level or the process sigma is calculated. This represents an alternative method to calculating process capability indices and process performance indices.

One of the ways to improve the performance of centrifugal pumps, proposed and experimentally validated by our research, is the method of creating so-called coherent structures, vortices and turbulence in the peripheral area of the centrifugal stage by adding a vortex rim to the back side of centrifugal rotor. A new construction of the pump, so called centrifugal vortex pump (CV), combines the good sides of these two types of pumps: high head of the vortex pump and high efficiency of the centrifugal pump. In addition, centrifugal pumps deliver higher flow rates with lower pressures, vortex pumps deliver higher pressures but with lower flow rates. For centrifugal vortex pumps, the vortex blades are located at the rear of the centrifugal rotor. The outer diameter of the vortex rim (VR) is smaller than the outer diameter of the centrifugal rotor (CR). The vortex rim induces vorticity to a portion of the flow that has passed through the centrifugal rotor. This vortexed flow is then reunited with the rest of the flow that has not been pulled down by vortex rotor. The vortex energy of that additional stream transfers some of its kinetic energy to the main stream. This added kinetic energy is converted to a pressure that accumulates the pressure exerted by the centrifugal rotor, and thus the vortex rim improves the overall pump performance. An intense process of gas dispersion occurs in the vortex region, which increases the stability of the pump when pumping a mixture of liquids and gases. The process of energy conversion in a centrifugal vortex pump, i.e., flow visualisation of mixing streams from a centrifugal rotor and a vortex rotor, and the quantization and superpositions have been shown in this paper.

The article clarifies the importance of maintenance in the exploitation of a particular medical device from the aspect of maintaining its availability, reliability and overall functionality. Particularly emphasized is the role of the preventive method or procedures that have a preventive character before the problems arise in the work. Through an analysis of the most common malfunctions and causes that occur during the exploitation, a basis for objective defining and proposing principles has been created – preventive maintenance with special emphasis on preventive maintenance according to an established condition. The article also shows a numerical way of calculating the periodicity of conducting preventive examinations on a particular device.