This paper studies flows on the labour market in Poland in 1995‒2008. We show that the main driving force behind the unemployment rate is the behaviour of outflow to employment. In addition, this flow is found to be procyclical, while the separation rate is acyclical.

The Stirling engine type alpha is composed of two cylinders (expansion space E and compression space C), regenerator that forms the space between the cylinders and the buffer space (under the pistons). Before the start-up and as a result of long-term operation, the average pressure in the working space (above the pistons) and in the buffer space is the same. However, in the initial phase of operation, the average pressure in the working space is different then the average pressure in the buffer space depending on the crankshaft starting position (starting angle). This, in turn, causes a large variation in the starting torque. An additional unfavorable factor caused by a large variation in the course of the indicated torque is the rotational speed variation and the formation of torsional vibrations in the drive system. After some time, depending on the quality of the engine piston sealing, the average pressure in the working and buffer space will equalize. The occurrence of the above-described phenomenon affects the selection of the starting electric motor, which can be significantly reduced, when the crankshaft starting position is optimized (the starting torque is several times greater than the average torque occurring in the generator operation mode). This paper presents the analysis of the impact of the crankshaft starting position on the course of the indicated torque and the resulting start-up energy. Starting the engine at an unfavorable position of the crankshaft may, in extreme cases, increase the starting torque even three times.

The constant increase in the population of cities affects the development of housing. Investors, in their activities related to the profit from the sale of flats, focus on the completion of residential buildings, which must be timely and in accordance with the budget assumptions. Therefore, there is a problem concerning the correct planning of the costs and duration of an investment. The aim of the conducted research was to determine the shape and course of the cost curves for construction projects related to the construction of residential buildings. Based on the analysis of the authors’ own studies carried out in a homogeneous research group of 11 residence buildings, an original attempt was made to determine the area of the curve, which indicates the area of correct planning of cumulative costs and the forecasting of their deviations in the financial outlays of construction projects. By knowing the planned cost and duration of a construction project, and by using the proposed 6th degree polynomial, it is possible to determine the planned monthly work and expenditure amounts, and thus correctly plan the investment costs over time. It was proven that the planned work and expenditure advancement of the housing construction sector is greater in the first stage of its implementation when compared to the actual state. The determined 6th degree polynomials describe the regularity that shows that for half of the planned duration of works, the planned work and expenditure advancement is approx. 46%, while the actual advancement is approx. 35%.