Essential oils and safety of their use

Currently, many herbal substances are used in everyday life products and in many industry such as food, cosmetics and others. Essential oils are mixtures of volatile organic compounds separated from plants or parts of them. They are characterized by an intense fragrance, but they have a diverse composition. Depending on the source, there are one or several dominant components. History acquisition of essential oils dates back to ancient times. Due to the unique fragrance qualities, the oils accompany humanity all the time. More perfect methods of analysis of the composition of essential oils used in cosmetics, food (spices) and aromatherapy, prompts us to consider the safety of their use. In addition to health-promoting substances, oils can also contain many organic compounds with an allergic or even toxic effect. Getting to know the essential oils composition and thorough acquaintance of consumers with possible risks of using essential oils is currently a priority for the producers of essential oils.

Risk assessment of threats in Czestochowa county based on the FEMA methodology

The article presents a description of the methodology of the Federal Emergency Management Agency, which allows for a detailed assessment of each threat separately, in a numerical manner. The FEMA methodology uses four criteria: history of the event, vulnerability, probability and maximum threat. The aim and method of research was determined and the risk analysis of threats in Częstochowa County was estimated on the basis of FEMA methodology. The conducted research allowed to draw attention to the advantages and disadvantages of the FEMA methodology.

PC-GMAW effect on the welding thermal cycle and weld metal geometry for high strength steels

Welding of medium carbon alloy steels used in the manufacture of special-purpose machinery imposes to solve two mutually exclusive problems – to increase the depth of penetration of the base metal and to reduce the width of the thermal impact zone of the welded joints. To successfully solve this problem, it is necessary to use arc welding processes with a concentrated heat source. One of these processes is pulsed current gas metal arc welding (PC-GMAW). The present researches have allowed estab-lishing, that with PC-GMAW change of welding current is a difficult character, namely: on high-frequency impulse signal (60 kHz), impulses of the current of low frequency (from 90–150 Hz) are imposed. The change in the values of the mean welding current at PC-GMAW is achieved by increasing the pause current and the frequency of high-amplitude current pulses. It is shown that the PCGMAW allows reducing the amount of metal splashing, to increase the depth of penetration (almost 2 times) in comparison with stationary welding. At the same time, the cooling rate of HAZ metal in the temper-ature range 600–500°C decreases almost 1.5 times, which allowed to reduce the width of HAZ by 40%.

New method of occupational risk assessment – Risk Analysis

The article presents a new method of risk assessment Risk Analysis. The first part of the article is an introduction that informs about the essence of risk assessment and addresses the lack of a parameter describing the impact of human behaviour on occupational risk in existing methods of risk assessment. The statistical information presented confirms the significant impact of human behaviour on the occurrence of an accident at work. The second chapter is devoted exclusively to the subject of risk assessment. The third chapter contains the main part of the article, i.e. the presentation of the author's own risk assessment method, which consists of an individually developed formula and parameters. The article presents the Risk Analysis method, as well as its features, which distinguish it from other methods. The method is characterized by accuracy, functionality, and an innovative approach to the subject of professional risk assessment.

Simulation of the influence of brake disc geometry of its cooling efficiency

The article discusses the problem of brake disc cooling and its impact on safety. Three variants of brake disc cooling were made, which were then used in the thermal load analysis with the use of FEM.