In this paper the general solution of nonlinear satellite pseudorange equation system has been given. This solution was obtained by the application of the new positional transformation determining relations between the points in three-dimension space. It has been proved that computation of the position does not require knowledge of the light speed, occuring in pseudorange measurements, or determination of approximate coordinates. The general solution allows one to obtain all possible solutions including complex conjugate positions. This work has also stated that there exists some space regions in which it is not possible to determine the positions in the domain of real numbers. This is especially important in navigation of objects moving in the space.

Waste plastics make up approximately 20% of the volume of landifill material and almost 10% of the weight. These products contain substantial energy recovery value, and also represent a potentia!iy valuable source of feedstock raw material for additional plastics production. Controlled pyrolysis offers a method of converting raw, mixed waste plastics back into feedstock grade liquids by the application of heat in the absence of oxygen. However, chlorine from the thermal degradation of polyvinyl chloride (PVC) can contaminate the reclamed liquids making them more difficult and expensive for processing, and also produce a corrosive atmosphere which makes processing more expresive. This paper reports on a study of the impact of PVC on the thermal degradation rates other plastics including polypropylene (PP), polystyrene (PS), low-density polyethylene (LDPE), high-density polyethylene (HDPE) and polyethylene terephthalate (PET) in a thermogravimetric analyzer (TGA). Commodity plastics were mixed at various ratios with PVC and analyzed by means of their degradation rates to determine the kinetic rate constants which were compared to the rates obtained for the pure plastics. The values of the kinetic parameters for the pure compounds were all very close to, or within the ranges obtained from the literature. The results indicated that the decomposition behavior of the mixtures differed from those of the pure polymers. These deviations were greatest for mixtures of PVC with polyethylene terephthalate where it was determined that the dehydrochlorination step of PVC catalyzes the decomposition of PET. Pyrolysis of mixtures of PVC and polysteryne at temperatures between 200° C and 350° C result in incomplete dehydrochlorination. This results in more chlorinated compounds being released at higher temperatures.

From the territory of Central Europe that lies north of the Sudetes and the Carpathians, occupied during the Roman Period by the Przeworsk and the Wielbark cultures, we currently have a record of only a very small number of Roman Imperial denarii issued before AD 64. The interpretation of these finds is hindered by the small size of this database and the lack of archaeological context. There are three possibilities; one of them is that these coins, or at least some of them, entered the region as a complement of a ‘Republican’ wave of infl ux, which contained a signifi cant amount of Roman Republican denarii. The second possibility is that the Early Imperial denarii passed into the Central European Barbaricum during the second century as a small admixture to a great wave of denarii struck after AD 64. The third option is that we ought to view the influx of the Early Imperial coins as an independent and a minor occurrence not related directly either to the ‘Republican’ or the ‘second-century’ wave. The view held by the author of this article is that the influx of the bulk of pre-AD 64 Imperial denarii is best explained by the first hypothesis.

Sixty seven zooplankton taxa were recorded in a total of 5 WP-2 net vertical hauls carried out in a year round cycle in Admiralty Bay. Copepoda were the most common and abundant group and Oithona similis was the dominant species throughout the area. Polychaeta, Ostracoda and Chaetognatha were also rather common and abundant. Euphausiacea, Amphi-poda and Salpae occured mainly in the central part and the outlet area of the bay. No differences in zooplankton assemblages diversity in the four investigated areas of Admiralty Bay were en­countered. However, distinct differences in species richness between the zooplankton of Ezcurra Inlet and the main basin of the bay were observed. The composition of zooplankton was rather stable throughout the year, but seasonal occurrences of larvae of Polychaeta, Crustacea, Echino-dermata and Ascidiacea were noted. A Ust of the 174 zooplankton taxa ever found in Admiralty Bay is presented by combining the present results with the existing scientific data.