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Poland, as for Europe, is a country with an average forest cover of approximately 30%. In these forests, more than 37M m3 of wood, mostly coniferous (over 80%), is harvested per year. In 2012, 4.2M m3 of sawn timber was produced (sawn timber without factory lumber). At the same time, in Poland there are over 8000 sawmills, whereas only about 700 of them saw over 90% of the harvested timber. So much fragmentation is a major cause of low sawmills innovation, particularly of those small ones. However, in recent years, a trend of development in this sector is noticeable, and it is through rationalisation of material and energy economy. One of the methods to increase the technical and economic effectiveness of enterprises involved in woodworking is to build in the combined heat and power system (CHP) plant with the ORC system into the existing infrastructure, which will be matched to the needs of the company. This article presents an analysis of the profitability of the investment based on the example of a medium-sized company sawing approximately 50,000 m3 of timber per year, and the economic analysis was performed for prices and costs valid in Poland. The analysis made for the 1650 kW(el) organic Rankine cycle (ORC) system, has resulted in a profitability index PI = 1.3, on the assumptions that the ORC system operates for 6000 h y(-1), will be purchased at the price of 4500 € kW(el)(-1) and at the price of electricity sales of 130 € MWh(-1).

Skull base tumors form a highly heterogeneous group. As there are several structures in this anatomical site, a large number of different primary malignancies might develop, as well as a variety of secondary (metastatic) tumors. In this article, the most common malignancies are presented, along with a short histopathologic description. For some entities, an immunohistochemical profile is also given that should be helpful in proper diagnosis. As many pathologic diagnoses nowadays also include genetic studies, the most common genetic abnormalities in skull base tumors are presented.

The influence of vapor superheating on the level of heat regeneration in a subcritical ORC coupled with gas power plantThe authors presented problems related to utilization of exhaust gases of the gas turbine unit for production of electricity in an Organic Rankine Cycle (ORC) power plant. The study shows that the thermal coupling of ORC cycle with a gas turbine unit improves the efficiency of the system. The undertaken analysis concerned four the so called "dry" organic fluids: benzene, cyclohexane, decane and toluene. The paper also presents the way how to improve thermal efficiency of Clausius-Rankine cycle in ORC power plant. This method depends on applying heat regeneration in ORC cycle, which involves pre-heating the organic fluid via vapour leaving the ORC turbine. As calculations showed this solution allows to considerably raise the thermal efficiency of Clausius-Rankine cycle.