This paper deals with the possibilities of minimizing the emissions of heterogeneous substances/pollutants (SO 2 , NO x and NC x ) per volume unit of processed timber, based on measurements of the design and operating performance of a mobile off-road system working in the forest environment. The forest production system is taken to mean the production system into which the material and resource flow and/or even the workforce flow enter. During the production process the material, power and/or workforce flow is transformed into the final product (processed timber, soil preparation, afforestation, etc.). Operating and/or design capacity is the control variable optimizing the operating mode of the forest production system. The quantities of emitted pollutants related to the work unit done by the production system represent the criterional function specifying the optimization of parameters of the mobile offroad system working in the forest sector. The conditions for the operating mode (performance) of the mobile off-road system working in the forest environment under which the minimum emitted pollutants related to the unit of done work are reached have been determined. The theoretical conclusions have been verified experimentally.Keywords: forest technology; SO 2 , NO x , NC x ; optimizing; minimization 126 J. FOR. SCI., 54, 2008 (3): [125][126][127][128][129][130] that NO x emissions could be effectively reduced by proper injection timing. The authors' focus was however the engine design.None of the above-mentioned authors has been engaged with a possibility of affecting the amount of emissions through the regime of work or by using the technique of rational performance and by specifying the work regime at which emissions are the lowest. Only Berg and Lindholm (2005) studied a possibility of fuel-related (CO 2 , SO x ) or engine-related (hydrocarbons, NO x ) emissions decreased by the use of renewable fuels and through the improvement of the engine design and better adjustment of engines designed for operations in the forest.Nevertheless, should the machine (system) be already made, emissions can be optimized by its suitable rational performance. The most important measures compensating the environment contamination by extraneous substances are preventive measures that can be applied on a larger part of the area of endangered forest ecosystems. According to Janeček (1992), the measures consist in the selection of appropriate and environment-friendly technologies including the choice of suitable machinery, and in using acceptable methods for the employment of machines with the rational performance. Possibilities to determine the rational performance of machines are further discussed in this paper.The objective of this paper was to present some results from the analysis and from the determination of mathematic conditions required for reaching minimum specific emissions from logging and transport operations in the forest in relation to extracted mass unit.
MAteRiAlS And MethodSThe outline of deduction of the...
