Fire protection durability of intumescent coatings after accelerated aging

The most common method of achieve the required fire resistance is by the use of passive fire protection systems, being intumescent coatings the fire protection material frequently used. These are usually considered thin film coatings as they are applied with a dry film thickness (DFT) between 0.3-3 [mm]. The required DFT is obtained by experimental fire resistance tests performed to assess the contribution of this reactive fire protection material to the steel member fire resistance. This tests are done after dry coating and a short time period of atmospheric conditioning, at constant temperature and humidity. As the coatings formulation is mainly made from polymeric basis compounds, it is expected that the environmental factors, such temperature, humidity and UV radiation (UVA and UVB) significantly affect the intumescent coating fire protection performance and its durability. This work presents a research study about the effects of aging on the fire protection performance of intumescent coatings. A commercial water based coating is submitted to an accelerated aging cycle, using a QUV Accelerated Weathering Tester. This tests aim to simulate 10 years of the coating natural aging. The coating durability is tested comparing the fire protection of small steel samples submitted to a radiant heat flux exposure from a cone calorimeter. In total, 28 tests were performed on intumescent coating protected steel specimens, of which 14 specimens were tested before the hydrothermal aging test and other 14 after accelerated aging. The experimental tests results of the steel temperature evolution shows that increasing the intumescent dry coating film thickness, the fire resistance time increases. After the accelerated aging cycles, the coating lose their ability to expand, resulting in an increase of the steel temperature of approximately 200 [ºC], compared to the samples without aging.

Female entrepreneurship in belarus

Nowadays entrepreneurship is one of the main key objects in internal policy of each country. More and more women start doing their own business and thus become integral participants of entrepreneurial activities. However, despite of the abundance of various scientific publications, female entrepreneurship is poorly understood phenomenon, which is needed to be carefully scrutinized. The general purpose of this work is to describe and analyse such phenomenon as female entrepreneurship generally in the world and separately and mainly in Belarus. Indeed, it intends to determine the factors that drive women's entrepreneurship in Belarus. The findings are supported by literature, gathered from different scientific researches and actual statistical data. The data used in the empirical part was collected from World Bank Enterprise Surveys and comprises the responses of representatives of 360 companies selected randomly from the population of the Belarus companies. With the help of descriptive statistics and the application of logistic regression simple models to determine which economic, social, fiscal and legal environmental factors impact on female entrepreneurial activity was possible to understand the female involvement in business activities and society of the country.