Processing differences between Serbian prepositions and nouns were investigated in two lexical decision experiments. The outcome of the experiments indicate that processing of nouns presented in their citation form is affected primarily by the amount of information (bits) derived from noun's probability. Processing of prepositions appeared to be more complex because, in addition to probability of preposition, processing latency is also affected by number of syntactic functions/meanings carried by a given preposition and number of congruent noun cases. None of these factors per se is correlated with processing latencies. However, when combined into a single unit (expressed in bits) significant proportion of processing latency variability has been accounted for. It was shown that prepositions are processed faster than nouns of equivalent frequency and equivalent length. We conclude this on the basis of the observed differences in slope from linear regression, but also on the basis of differences in averaged RTs for the two word types.

In this paper, we present an ontology-based approach for the improvement of searching in an information portal. The approach is based on incremental refinement of user's queries, according to the ambiguity of a query's interpretation. The so-called Librarian Agent plays the role of the human librarian in the traditional library - it uses information, about the domain vocabulary, the capacity of the knowledge repository and the behaviour of previous users in order to help users find the resources they are interested in. Moreover, the agent analyses the users' requests off-line and compares the users' interests with the capacity of the information repository, in order to find which new topics should be introduced or which topics users are no more interested in. We partially im plemented the approach in the Web Portal of our Institute and some initial evaluation results are shown.

Air coolers consume much more energy compared to other heat exchangers due to the large fan power required. This is an additional reason to establish reliable methods for the rational design and thermohydraulic analysis of these devices. The optimal values of the outlet temperature and air flow rate are of particular importance. The paper presents a methodology for the thermohydraulic calculation of air cooler performances, which is incorporated in the "Air Cooler" software module. The module covers two options: cooling and/or condensation of process fluids by ambient air. The calculated results can be given in various ways ie. in the tabular and graphical form.

The determination of the optimal process conditions for the operation of air coolers demands a detailed analysis of their thermohydraulic behaviour on the one hand, and the estimation of the operating costs, on the other. One of the main parameters of the thermohydraulic behaviour of this type of equipment, is the outlet air temperature. The influence of the outlet air temperature on the performance of air coolers (heat transfer coefficient overall heat transfer coefficient, required surface area for heat transfer air-side pressure drop, fan power consumption and sound pressure level) was investigated in this study. All the computations, using AirCooler software [1], were applied to cooling of the process fluid and the condensation of a multicomponent vapour mixture on two industrial devices of known geometries.