This paper demonstrates that if a linear dependence of arc dissipated power on power supplied is introduced at an initial stage of analysis, then, with some simplifying assumptions, the classical Mayr model is obtained. Similarly, if this dependence is taken into account in a model with residual conductance, the modified Mayr model is obtained. The study takes into consideration the local phenomenon of sudden voltage drop accompanying linear current decrease occurring in the circuit breaker. To account for this phenomenon, the Dirac delta function and its approximation by a Gaussian function, representing power or enthalpy disturbances, are introduced to the power balance equation. It is demonstrated that both variants yield the same effect, leading to identical differential equations. Macromodels of the circuit-breaker arc are created and connected with the power source circuit with lin- early decreasing current. The results obtained were found to be consistent with experimental data available in the literature. The models presented are based on a fairly uncomplicated 1st order differential equation and offer a straightforward physical interpretation of the phenomena in question.

In order to improve the toughness of traditional epoxy resin, dibutyl phthalate (DBP) was introduced into the epoxy resin. The static mechanical performance of plasticized and unplasticized epoxy resin was evaluated. The test results showed that the DBP modified epoxy resin can obtain a higher toughness than conventional epoxy resin, but the elastic modulus and the tensile strength were slightly reduced. The low cycle fatigue test results indicated that the stress ratio and the stress level were two critical factors of fatigue life, which was increased with the growth of stress ratio. It was also found that the fatigue life of plasticized specimen was much less than that of the unplasticized specimen because of the plastic deformation. A logarithmic linear relationship was then established to predict the fatigue life for plasticized epoxy resin. The strain energy density was also applied to demonstrate the accumulation of energy loss. In addition, the fatigue toughness can be obtained by the hysteresis loop area method.

The results of chemical and biological analyses of lake water samples, taken in the Bunger Hills during January—March 1987 by the participants of the 32-nd Soviet Antarctic Expedition from the new seasonal station „Oasis-2" (66°16'S and 110°45'E) are presented. It was discovered that the sea contributed considerably to the formation of intraoasis isolated reservoirs. The water of the epishelf lake — Transkripcii Bay — consists of two layers: upper freshwater (0,3—l,0‰) and lower salt water (19‰); the bottom water contains H2S. The phosphate concentration varied from 3—8 mg 1-1 in freshwater lakes to 37 mg 1-1 in Rybij Chvost Bay (Pass Cove), where the high concentration of chlorophyll „a" (up to 10 mg 1-1) was found.

At the current stage of information technology development there is no need, as yet, to modify Polish norms referring to the maritime transport of cargo. Information technology can be applied without limitation. Therefore, the maritime code modeled on RHV normalizations can remain without alteration and maintain the consistence of solutions in both international and domestic law.

In the paper, I analyze four types of ontic subordination, which constitute key elements of Ingardenian ontology: heteronomy, derivativeness, non-self‑reliance and dependency. This analysis leads to the conclusion that the concepts constructed by Ingarden are either logically incorrect, or are not sufficiently explained, or refer not to ontic but to semantic relations.

The long-ranging Early to Middle Triassic coniform conodont form-genus Cornudina Hirschmann occurs

abundantly in the Anisian of NW Turkey, Northern Tethys. Although suggested to represent the P1 element

of an apparatus of the Order Ozarkodinida Dzik, questions concerning the apparatus of Cornudina remain.

A description of the probable phylogenetic trends in the P1 elements of Cornudina is attempted and the role

of the form-genera Ketinella Gedik and Kamuellerella Gedik, as the alternative ramiform skeletal elements in

the Cornudina multi-element apparatus, is investigated. The newly described, Gedikella quadrata gen. nov.,

sp. nov., is an S element, Kamuellerella rectangularis sp. nov., is either an S3 or an S4 element, and Ketinella

goermueshi sp. nov., is an M element.