The paper presents an estimation of liquefaction susceptibility of some soils from the coast of the Marmara Sea, which was heavily

striken by the Kocaeli earthquake in 1999. Firstly, the results of field investigations are summarized. Then, the results of laboratory investigations of physical and mechanical properties of the soils collated from the sites investigated are presented. The mechanical properties relate to the compaction/liquefaction model of saturated soils. This model is briefly outlined, then respective experimental procedures dealing with its calibration described, and values of material parameters listed. Liquefaction potential of investigated soils is analysed using standard procedures, based on the grain size distribution curves and SPTs. Finally, the simulation of pore-pressure generation and onset of liquefaction of Turkish soils is carried out, using the compaction/liquefaction model. Discussion of some standard empirical procedures of estimation of liquefaction potential of saturated soils, conducted from the analytical point of view, is also presented.

This paper presents numerical simulationsof the behavior of a sandy layer subjected to a cyclic horizontal acceleration in shaking table tests, with a particular attention focused on the settlements of a dry sand layer, and on the liquefaction of saturated sand. A compaction/liquefaction model (C/L) is applied to these simulations. The infl uence of specifi c parameters of the model on the compaction and liquefaction of a sandy layer is shown and discussed. The results of simulations are compared with selected experimental data.

The author of the dissertation described two unpublished so far hand written musical Oktoihs (Znamenny chant) of the Old Believers from his private collection. Based on those manuscripts the author indicates the important codicological and paleographical features of musical writing of the Theodosian and Pomorian Old Believers. Furthermore, the author presents the structure of the Oktoih book used by the Old Believers and makes overview of the polish literature concerning the discussed issues. The aim of the dissertation is to encourage other collectors of ancient manuscripts to share their collections and elaborations with researchers.

The paper includes the TG-DTG thermogravimetric air-testing of a cellulose mixture modified with the additives of expanded vermiculite or expanded perlite. A thermal degradation test was carried out at 1000°C with a simultaneous qualitative analysis of the emitted gases. During the thermal degradation process, the thermal effects were also measured. The research results indicate that expanded vermiculite or expanded perlite do not emit toxic gases during thermal degradation. The cellulose mixture modification, with the additives of expanded vermiculite or perlite, does not result in the creation of new gaseous compounds in the process of thermal degradation. A s investigated below, the mixtures tested in this article find application in gating systems for supplying liquid metal in no-bake moulds. Such cellulose-based material solutions shall allow the foundry industry to introduce less gas vaporising technologies within the entire casting production process.

This paper presents the findings of a study of gas emissivity and the volumetric gas flow rate from a patented modified cellulose mix used

in production of disposable sand casting moulds. The modified cellulose mix with such additives as expanded perlite, expanded

vermiculite and microspheres was used as the study material. The results for gas emissivity and the gas flow rate for the modified cellulose

mix were compared with the gas emissivity of the commercial material used in gating systems in disposable sand casting moulds. The

results have shown that the modified cellulose mix is characterized by a lower gas emissivity by as much as 50% and lower gas flow rate

per unit mass during the process of thermal degradation at the temperature of 900°C, compared to the commercial mix. It was also noted

that the amount of microspheres considerably affected the amount of gas produced.

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.