Analysis of the Costs and Revenues of Agricultural Products in the Selected Countries of Central Europe

The paper compares and evaluates the development of the total production costs incurred for the production of selected agricultural crops and generated revenues in four Central European countries. Consequently, it also assesses the profit or loss statement. The comparison is made between countries and over time. The paper also assesses the proportion of overhead costs to total costs incurred for own crop production. We also track the profitability of incurred costs for agricultural products in these countries in order to provide information not only to scientists, but also representatives of agricultural industry. The partial objective of the paper is also to assess costs and revenues separately for livestock and crop production. In assessing agricultural companies are still used traditionally calculation methods. Currently, traditional cost calculation methods are not considered sufficiently accurate. The paper points out to the possibilities of modern cost management and their benefits to the traditional agricultural sector

Removal of Sulfur Compounds from Mineral Insulating Oils by Extractive Refining with N

Copper sulfide deposits in the insulation systems of power transformers decrease the dielectric properties of the insulation and therefore constitute a significant risk for the operation of power transformers. Disulfides, oxidized sulfur compounds, thiols, and elemental sulfur, which could be present in insulating oil, have been recognized as the sources of reactive sulfur responsible for copper sulfide formation. Selective liquid liquid extraction using N-methyl-2-pyrrolidone solvent was investigated for the purification of mineral insulating oils through the removal of compounds and precursors responsible for copper sulfide formation. The efficiency of the extraction process was evaluated using corrosive sulfur test IEC 62535, SEM/EDX measurements of paper before and after the IEC 62535 test, and measurements of the dibenzyl disulfide concentration in the oil using GC-ECD method. The oxidation stability of refined oils was evaluated using the IEC 61125 method. Precursors of copper sulfide deposits were completely removed from different mineral oils as a result of purification by extraction with N-methyl-2-pyrrolidone and 1.0 wt % water as a cosolvent