Slavko Šarić

Application of numerical methods to thin-layer chromatographic investigation of the main components of chamomile (Chamomilla recutita (L.) Rauschert) essential oil

Abstract The efficiency of eleven TLC systems for separating the main components of chamomile essential oil has been tested. The information theory and the methods of numerical taxonomy have been applied for this purpose. The design of the most effective series of chromatographic systems is discussed in terms of discriminating power and mean information content. The series of systems with the highest discriminating power is shown to produce the best overall separations for a large specified population of components of chamomile essential oil. It leads to the identification of an unknown component using a minimum number of systems. It has been established that the most favourable mobile phases for TLC of chamomile essential oil are chloroform–toluene (75:25) and chloroform–toluene–ethyl acetate (65:30:5) mixtures.

USE OF INFORMATION THEORY AND NUMERICAL TAXONOMY METHODS FOR EVALUATING THE QUALITY OF THIN-LAYER CHROMATOGRAPHIC SEPARATIONS OF FLAVONOIDS AND PHENOLIC ACIDS OF RHAMNI CATHARTICI FRUCTUS

A rational selection of a restricted set from fifteen available chromatographic systems for the separation of flavonoids and phenolic acids identified in the methanolic extract of Rhamni cathartici fructus is discussed. Series of mathematical techniques for the evaluation of solvents and solvent combinations in thin-layer chromatography of flavonoids and phenolic acids have been investigated. The chromatographic systems are classified according to their mutual resemblance by numerical taxonomy techniques. The selection criterion in the groups, obtained by numerical taxonomy classification, is the information content or discriminating power. The numerical taxonomic and information theoretical selection procedures are compared and their respective advantages and disadvantages discussed.

AUTOMATION IN DEVELOPING TECHNICAL DOCUMENTATION OF TELECOMMUNICATION NETWORKS

During the last decade of the 20th century, intensive developmentof telecommunication infrastructure set high requirementsregarding technical documentation that started to haveproblems in following the changes in the network. In the lastseveral years HT made a great shift regarding automation andpresentation of technical documentation, that is introductionof GIS (Geographic Information System), as precondition forthe introduction of DIS (Documentation Information System),thus realising the necessary preconditions to use the gatheredand organised spatial and atllibute data, for higher quality ofanalysis, processing and repair of interference in the telecommunicationnetwork The aim of this paper is to inform aboutthe segments and computer programs used for the developmentof technical documentation.

Intelligent Network in the Republic of Croatia

The introduction of intelligence into the telecommunicationnetwork of Croatia is becoming one of the key elements ofthe future development of the network. The paper describes there-organisation of the telecommunication network in Croatia,the process of creating and managing the intelligent services,the initial situation and the feasible plan of introducing the INconcepts. The paper is concluded with a list of IN services thatare being introduced in the initial phase of the Croatian telecommunicationnetwork.

Djelovanje elektromagnetskih polja na sudionike u poštansko-telekomunikacijskom prometu

The paper deals with the effects of electromagnetic fields upon participants in postal traffic (employees and users). The authors first provide a general review of the effects of electromagnetic fields upon people, and then a special reference is drawn to the examination of properties of non-ionizing electromagnetic fields (of particular intensity with postal radio relay facilities), possible harmful effects of subject fields upon people, and individual aspects of protection and their efficiency.