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Agricultural Engineerin, 2015, Issue 4 (156)
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156 # 3679
Assessment of the change in the rolling resistance of a wheel in varied field conditions

The paper presents the research results concerning the rolling resistance of a wheel on agricultural surfaces. Research on traction was carried out in field conditions with the use of a mobile stand; a wheel with 9.5-24 tyre was investigated; values of the rolling resistance and the pulling force were analysed with reference to the wheel slip. A type of surface (soil, sod), its compaction and the vertical load of a wheel were assumed as factors. Based on the obtained results, it was proved that the rolling resistance was by approx. 30% higher on soil than on sod. Differences resulting from the variety of surfaces were higher than the differences caused by various values of their compaction (did not exceed 25%). No significant impact of compaction changes on the rolling resistance and pulling force values were proved but a considerable increase of the rolling resistance value along with the decrease of its compaction were determined. Moreover, it was proved that the increase of the vertical load of a wheel resulted in the increase of the rolling resistance and the pulling force on both grounds but these changes were higher on soil than on sod.

156 # 3680
Analysis of the power flux in the tractor wheel-farming ground system

The paper presents results of the research on the power transmission from the tractor wheel onto the grounds with different properties. The research was carried out in field conditions with the use of a stand aggregated with a farm tractor. Firstly, an initial evaluation of tractive properties was carried out by determination of the traction force and efficiency. In the fundamental part of the research values of the useful power (drawbar power), power lost to the rolling resistance and the power lost to the wheel slip were determined. A vertical load of a wheel, except for the ground type, was an additional factor. Based on the obtained results, it was proved that a wheel used on soil had higher values of the traction force but lower tractive efficiency in comparison to the values obtained on sod. Analysis of the power transmission proved that these differences result from higher power losses related to the rolling resistance of a wheel used on soil. Moreover, it was proved that the increase of the vertical wheel load favours the improvement of traction properties (increase in the tractive efficiency and the drawbar power shares) only in case of a wheel exploited on sod.

156 # 3681
Evaluation of changes in traction properties of a drive wheel on the sod utilized by various means

The paper presents research results, the objective of which was to assess the traction properties of a wheel equipped with a drive tyre on sod with a varied species composition of plants and various usage level. Based on the measurements carried out with the use of a unique stand for traction research, the slip, traction force and efficiency were determined. It was proved that the species composition of sod and usage level resulted in varied values of the analysed parameters. Higher values of the traction force were obtained on sod I at the usage level of 50 and 100%. Maximum values of the traction efficiency on both sods, regardless the usage level, occurred at the wheel slip lower than 20%. In order to describe the condition of facilities, where traction research was carried out, moisture, compaction and maximum shearing stresses were measured.

156 # 3682
Methodological notes concerning determination of the scientific and technical progress rate and its efficiency

Based on the previous micro and macro-economic scale research studies concerning agri-economic rates, not only positive aspects of the suggested and tested methods of assessment of the mechanization level were taken into consideration, but also repeatable methodological weaknesses which ultimately affect the final research results. Thus, this paper suggests methodological changes concerning determination of indicators which decide on the level of the management intensity and in particular of the scientific and technical progress and its effectiveness for individual farms. Numerical data obtained from Małopolskie and Świętokrzyskie Voivodeship were used in the paper.

156 # 3683
Root biomass distribution in a energy willow plantation

The objective of the paper was to determine the distribution of energy willow roots biomass, which is significant for developing a structure of a machine for reclamation of fields after their cultivation. The scope of work covered the research studies carried out on 30 rootstocks of energy willow, which come from a plantation set up in 2003 in the Department of Production Engineering and Power Energy of the University of Agriculture in Krakow. A vertical scope of thick roots with a diameter above 30 mm was at the average 42.3 cm and the horizontal one was – 51.6 cm. Total fresh mass of rootstock (roots + butt log) was 18.61 kg at the average, and the mass of thick roots was – 7.75 kg.

156 # 3684
Cost optimization of blend preparation with the use of the FlexSim environment

This work presents a new approach to solving the problem of optimization of selection of the blend components quantity. The problem of blending refers to provision of the required amounts of nutrients, at minimal cost of purchasing the products needed for production of a compound feed. The problem of diet is essential for humans, animals and agricultural production. In the presented case the linear programming method in the Flexsim environment was applied. Firstly a simulation model was built that shows the technology of preparing the mixture, while maintaining the minimum required amounts of nutrients. Secondly, the optimizer tool was used to determine the structure of the nutrients, so that the cost of purchase was the cheapest. The results are presented in a numerical and graphical form.

156 # 3685
Economic aspects of Rosa multiflora Thunb. biomass production

The objective of the paper was to determine the elements of economic assessment of multiflora rose cultivation as an energy plant. A one - factor field experiment carried out in Mydlniki near Krakow in the years 2009-2013 was the object of the research. The impact of two doses of irradiation with laser beams of seedlings on the economic efficiency of multiflora rose cultivation was investigated. As a result of the research, it was stated that extensive cultivation of multiflora rose is economically profitable. The cost of seedlings (57.5%) constituted the highest share in costs of setting a plantation. A gross margin with a direct payment for one year long plantation was similar to the analogous value calculated for energy willow. Cultivation of multiflora rose may be an alternative for cultivation of energy willow especially on poor sandy soils.

156 # 3686
Methodological aspects of determination of resultant force acting on the cultivator spring tines

This paper presents aprocedure for determination of the tilt angle of the resultant force and the point of its application on the cultivatorspring tine. These parameters include the temporary value of horizontal and vertical force, moment of force and cutting depth. Numerical methods were applied to determine the point of application of the resultant force as an intersection point of the resultant force direction and the circuit described on the cultivator point curvature. Calculation algorithms include changes in the position and geometry of the cutting system caused by a dynamical load of a tool. Tests were carried out in field conditions in the sandy clay of 11.2% density moisture. Two depths of cutting with four tines, which differ with flexibility coefficients, were applied. It was stated that the setting parameters of the resultant, calculated with the use of the presented method, have low-value standard deviations. It was also found out that the tine flexibility and cutting depth positively influence the tilt angle of the resultant and the tine flexibility affects only the distance of the point of the resultant force application on a tool from the bottom of a furrow.

156 # 3687
Modernization of the wastewater control system in the food industry

In order to reducethe influence of wastewater from enterprises on the environment extreme relevance is gained by improvement of the monitoring system at each stage of technological process. A new tool - calculation of the polluting substances concentration is suggested to be entered into the monitoring system on the basis of determination of material balance of the technological process of production that will allow prediction of qualitative and quantitative composition of sewage for the selected period. The system can be used in any enterprise, but the example with all calculations is given for the Mykolaiv Branch of \\\"SUN InBev Ukraine\\\" which became the object of research. The scope of the study covered the process of wastewater formation of the enterprise. Realization of tasks demanded the use of general scientific methods: analysis, synthesis, systematization and generalization in the course of studying of the corresponding literature on the research subject; modeling, formalization, comparison - at drawing up the calculation scheme of concentration of the polluting substances in sewage; supervision - during studying the technological scheme of production; and also methods of mathematical data processing in MS Excel.

156 # 3688
The impact of wheel spacing on allowable force applied to the axis of the agricultural vehicle

The objective of the study was to develop computational methods for determination of the impact of the twin-wheels (their positioning along the axis) and soil conditions, specified by the stress concentration factor, on the limit values of the forces loading the axis of the agriculture vehicle, thus reducing the risk of excessive soil compaction. The formula of Boussinesqu (1885) supplemented by Frȍhlich (1934) with the stress concentration factors was used. The values of the limit force were determined by adopting assumptions that wheels loaded soil surface in points and stress caused in soil should not exceed its agro-technical bearing capacity defined by the value of the limiting stress. The developed method allows setting the limit value of twin-wheelbase, at which the effect of adjoining force onto stress in soil semi-space fades away. This means that through a relatively small change of a wheelbase, it is possible to achieve more convenient conditions of load transfer on soil, in the context of the risk reduction of excessive soil compaction. The proposed method enables to construct diagrams for calculation of allowable axis load on the base of the known value of stress within the soil profile which determine its agro-technical capacity.

156 # 3689
Analysis of changes in the area and number of farms in Wielkopolskie and Malopolskie voivodeship

The objective of the paper is to analyse the changes of the agricultural land area and the number of farms in Małopolska and Wielkopolska region as two separate agricultural regions. The research period starts with the Poland's accession to EU and ends in 2013. The land use structure, number and size of agricultural farms were taken into consideration. Additionally, the paper includes analysis of changes in the agricultural land prices. It was stated that agriculture in Małopolska undergoes positive transformations, is still developing and various EU subsidies are one of its development factors. Positive changes were observed mainly in the decrease of the number of individual farms and the increase of the average area of farms. Within the analysed ten years, the agricultural land area decreased by over 186 thousand ha, that is by 25%. Agriculture in Wielkopolska region gained a lot due to the EU accession. However, in this region the changes had different nature. The land utilization remained at the same level as in 2004 and positive changes were observed mainly in the decrease of the number of small farms for the benefit of the biggest ones. The paper constitutes the first part of the developed cycle of publications concerning transformations of the technical agricultural infrastructure of Poland after its accession to the EU.

156 # 3690
Agricultural information as an example of intangible resources in the selected group of agricultural producers

The paper makes an attempt to characterize intangible resources and determine effectiveness of their management in farms grouped in the producers' group. The paper covered 15 plant farms associated in the agricultural producers' group. The research was carried out in the form of a guided survey. Source data from the production year 2013/2014 were analysed. Agricultural information, which as a resource, influences the value of the enterprise and determines the possibility of obtaining competitive advantage, is an example of intangible resources. Agricultural information is a source of knowledge on inter alia market situation, production sources or technical progress. It is also a source of knowledge for a farmer. The investigated farmers expanded their knowledge and skills taking part in various types of trainings, both those carried out by a group and other entities. As much as 80% of the respondents participated in the training on "Crop protection compliant with the integrated production principles". The second was the training on the use of crop protection substances with the use of a sprayer with 33% of respondents taking part therein. The fact that more than half of the surveyed farmers participated in more than one training and one took part in three different trainings should be emphasised. All trainings aimed mainly at raising the farmers' knowledge to realize the most important tasks of the group - production of high quality products with the proper use of intangible resources.

156 # 3691
Comparison of pollutant emission indicators during virginia mallow pellets and wood pellets combustion – a case study

Ecological aspects and environmental threats indicate that wood pallets should be used mainly in low-power furnaces for heating households. Because burners and fuel feeding systems were adjusted to wood pellets, pellets from other types of biomass, including the waste biomass in systems which enable a controlled process, should be considered. Taking into consideration the possibility of use of Virginia mallow pellets for supply of low-power furnaces as alternative fuel to wood pellets, the objective of the research was to determine and compare indicators of emission of CO, NOX, SO2, 16 WWA including B(a)P, TOC and dust during combustion of these two biofuels. Emission indicators were referred to the mass of combusted biofuel and the amount of the obtained energy. Installation used in the research was a typical installation used for heating of one-family houses and designed for combustion of pellets. CO and dust emission indicators for Virginia mallow pellets were considerably higher in comparison to the indicators for wood pellets. Emission indicators of the remaining pollutions (SO2, NOX, TOC, dust, WWA, B(a)P) were similar to both tested biofuels.

156 # 3692
The application of the SWOT and AHP methods for the assessment of region`s strategic position in the aspect of wind energy

The paper suggests a method for diagnosis of a region's strategic position with the use of two decision tools: SWOT analysis (strong, weak points, opportunities and threats) and a multiple criteria method AHP. The integration of the methods constitutes a complex approach, which may be useful at the assessment and forecast of the development strategies of regions for particular types of renewable energy sources. The AHP method enabled structuring of the decisive problem and quantification of the significance of SWOT factors, both quantity and quality ones, being at the same time a very comfortable mathematical apparatus. The paper presents a theoretical aspect of methodology, and in the practical perspective, an approach to establishing a strategic position of Małopolskie Voivodeship in the aspect of using wind energy was suggested. There is a development trend in the voivodeship based on the defensive strategy, namely on the unfavourable arrangement of factors - more weak points than the strong ones and more threats than opportunities.

156 # 3693
Options of use of waste biomass from herbal production for energy purposes

The objective of the research was to determine and compare the value of the heat of combustion of waste biomass in the form of above-ground parts of the selected species of herbs. The research included leaved stalks of milk thistle, non-leaved stalks of thyme and garden sage and inflorescence axes of lavender and fennel. The heat of combustion of waste biomass was determined with the use of a calorimeter according to the applicable standard PN-EN ISO 9831:2005. Based on the obtained results it was stated, inter alia, that, from among the investigated species the lowest average value of the heat of combustion of 13.28 MJ∙kg-1 was in case of biomass obtained from milk thistle. The heat of combustion of biomass of the remaining species was similar and it was at the average of 20.47 MJ∙kg-1. Weight of ash after combustion was the highest in case of milk thistle and it was 0.23 g whereas in case of the remaining species it did not exceed 0.03 g.

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