Jozef Harangozó

Minimum Ignition Temperature of Wood Dust Layers

Abstract Fire characteristic (properties) are used to determine the fire risk and explosion hazard of materials. They are defined as numerical values which describe behavior in the process of burning. They can be determinate by standardized test methods. In this paper is described the most important fire technical characteristic of dust layer (minimum ignition temperature) and the results of standard laboratory method determination for wood dusts, aswell.

Software Design to Calculate of Vibration for a More Effective Assessment of the Safety of the Working Environment

Abstract A lot of software that is developed simultaneously with the development of new measuring devices are very difficult to control. The results obtained from the software for measuring the vibration must be adjusted for the respective weighting factors which is very complicated and time consuming. This paper deals with design of software to calculate human exposure to vibration in the working and living environment. Presented software developed at the Institute of Integrated Safety, which counts with all the weighting factors. It allows quick results without after treatment weighting factors. Presented software includes all known methods for calculating the vibration acceleration. It’s based on knowledge of the protection of man and his health against the negative effects of vibration. The measured data are evaluated according to the current legislation of the European Union. Simple layout software doesn’t have a good first impression, but it’s control is very swift and practical. Every reader needs to read about it below.

Development of the Hexagonal Structure in the Processes of Improving Vibration Insulating Properties of Products

This paper deals with noise and mechanical vibration reduction by optimization and proper application of the hexagonal cell structure formed on the surface of oscillating bodies. This structure can be applied in a broad spectrum of products like home appliances, industrial machines and devices, drives etc. It stems from the knowledge of the area of human health protection against the negative effects of noise and vibrations as well as psychological comfort, performance and optimization of psychoacoustic perceptions. The authors present the design of a suitable parametric model which makes it possible to change the basic structure parameters and by means of numerical simulations approach the achievement of optimal structure parameters.

Study of Effect of Flame Retardants on Initiation Process of Lignocellulose Materials at Heat Flux Acting

The present paper deals with the study of effects of heat flux on flammability of lignocellulose materials at application of flame retardants, which may restrict or retard the burning of mentioned materials. Significance of the impact of heat flux is important from the viewpoint of fire protection. The heat flux is namely one of the most critical factors causing ignition, the subsequent flame propagation, and last but not least it also affects the burning rate. The aim of this paper is to present the results achieved from experimental measurements of heat flux acting on the selected lignocellulose materials with and without application of flame retardants.

The Effect of External Conditions on Ignition Temperature of Thermoplastic Polyurethane Elastomers

The paper reports a study of the impact of moisture and age of pellets, as well as an external condition, on the thermal degradation of the thermoplastic polyurethane elastomers. Because thermoplastic polyurethane elastomers are hydroscopic polymer, moisture will have a significant impact on thermal degradation. For determination of the effect of moisture and age were used the thermo gravimetric analysis, differential scanning calorimeter and ISO STN 871: Plastics. Determination of ignition temperature using a hot-air furnace.

Assessment of Functionality of Aged Cables at Loading by Heat Flux

Polymers belong to most spread organic flammable materials. They are decisive material – insulator also in cable production. Regarding the safety of buildings it is necessary to know their fire-technical characteristics, which predict their behaviour in case of fire. The article deals with testing cables protected and non-protected with intumescent coating, exposed to heat flux, in dependence on distance. A special equipment was developed for testing the inflammability, allowing objectivisation of critical conditions leading to ignition of tested materials.

Determination of Ignition Temperature of Organic Dust Layers

Fire characteristics of wood dusts serve for qualitative comparison of combustibility and explosibility, for suggesting precautionary measures, for predicting consequences of fires and explosions. Setting of given characteristics by calculation is not possible yet. Therefore the most reliable results are set by experiment. The article deals with the testing of the minimum ignition temperature depending on the different types of dust layer and different heights of surface.

Influence of Retardants to Burning Lignocellulosic Materials

Influence of Retardants to Burning Lignocellulosic Materials The paper deals with monitoring retardant changes of lignocellulosic materials. Combustion of lignocellulosic materials and fire-technical characteristics are described. In assessing the retarding effect of salt NH4H2PO4, fire-technical characteristics as limiting oxygen index (LOI) were measured, and by using thermoanalytical TG and DSC methods. High-temperature process of cellulose degradation at various flame concentrations was studied.