Search

Paper and paper products play an important role in every area of human activity. Its importance is determined by its use for recording, storage and dissemination of information, as a material for wrapping and packaging, as well as for constructive application. This determines the unlimited possibilities and application of paper materials. The aim of the present work is to study the interdependencies between the components of the paper - fibrous materials from which the papers are obtained, the technological mode of their processing and ecological chemical auxiliaries in view of the possibilities of obtaining papers with multifunctional properties and special barrier properties such as water resistance, biocidality, durability, mechanical strength. The paper is characterized by a heterogeneous capillary-porous structure formed by drainage under certain conditions of a highly dilute aqueous dispersion, representing a reversible thixotropic-coagulation system. The elements of this system are both different in nature and suitably treated fibres, as well as different fillers and various chemical auxiliaries. The chemical auxiliaries added to the plant fibres form, above all, the necessary properties of the paper sheet, support the production process and enable the saving of fibrous material. When processing paper and cardboard by physicochemical methods, composite materials having a new supramolecular structure are obtained. The processes of coating, impregnation, etc. also belong to the physicochemical processes for processing papers and cardboards. The preservation of the reinforcing role of cellulose fibrils and fibres at all stages of the transition to paper and its processing is possible only due to the targeted change in the physical (relaxation) state of the polymers. The transition of the amorphous regions of the cellulose to a highly elastic state and the preservation of its crystal structure ensures the intermolecular interaction between the cellulose and the other polymer components. After selection of suitable fibrous materials and subsequent treatment, selected chemical auxiliaries are added to the paper suspension to obtain special properties of the papers. There is a mutual connection between the different functional properties of the obtained papers. Different methods can be used to achieve certain properties of the paper. [ABSTRACT FROM AUTHOR]

The purpose of the present study is to analyse the current state of the Bulgarian capital market within the framework of the strategic priorities for deepening of its integrational links to the European capital markets. The paper presents results from correlation analysis of indicators of integration of the Bulgarian capital market to the Eurozone. The results point to medium degree of integration of the Bulgarian capital market. Irrespective of the high degree of harmonization of the regulatory framework and market practices on the Bulgarian capital market still exist various barriers at micro and institutional levels. [ABSTRACT FROM AUTHOR]

Epidemiological studies are performed in some towns and large industrial regions of the country, in order to establish the changes in the health state of the population, due to atmospheric pollutants. The attention is directed to regions with national industrial branches, most intensively polluting the atmospheric air (metallurgy, chemistry, petroleum-chemistry, cellulose-paper industry) and such, where the air pollution is related first of all to transport across the border-line. The unfavourable effect of the atmospheric pollution on the exposed population is proved. It is however, the reason for increased morbidity according to a number of nozologics and on first place--of respiratory and allergic diseases. Parallel to that are interpreted the results of the performed inquiries and paraclinical studies, revealing the presence of prior to the disease changes in the population of the examined regions.

In one of the studied towns with a large plant for cellulose and paper and another for fodder yeasts the ambient air was polluted by specific contaminants--hydrogen sulfide and mercaptans considerably higher in town R than in town B after data of the Principle Hydrological and Meteorological Administration. A higher incidence was established both in the general morbidity and the nosological units, probably etiologically determined by the defined pollutants in town R. Both the allergic reactivity and the clinico-laboratory indices, which characterise the functional state of the exposed pollution, were raised. The results give grounds to believe, that the ambient air pollution in town R is a risk factor for the health of the population.