Cultivators are machines used among others to open and smooth out the surface of the ploughland and to mix mineral fertilizers with soil. The article presents a design of a cultivator mounted on an agricultural tractor with a power of up to 20 kW. The main design assumption mainly focuses on keeping the weight of the device low, while ensuring the required durability. Moreover, the design makes it possible to attach it to the three-point linkage in a category 1 tractor. The drafted design was subjected to the MES analysis, according to which, the maximum travel of the cultivator frame does not exceed 1.3 mm, and the stress typically reaches the level of 40 MPa and does not exceed the stress permissible for the E295 steel. An analysis of the costs of manufacturing the cultivator was also performed and on its basis, it was found that the price should not exceed PLN 1,800.

VLSI package designs continue to utilize relatively large dies in smaller packages. Elevated thermal stresses are likely to occur in such configurations during fabrication, testing, and operation of these packages. This paper presents a parametric study of thermal stresses in plastic packages that are induced during the die attach and encapsulation fabrication steps. Finite element models (FEMs) of plastic VLSI packages were used to vary package design parameters (die thickness, die bond materials and thickness, lead frame thickness, and package thickness and width/length) over typical ranges. Areas of complexity were considered in more detail using locat finite element analysis. The loss of adhesion between the mold and the die and/or lead frame in the package was simulated using gap finite elements in order to consider the extreme cases of no slip or no adhesion at these material interfaces. Changes in die thickness, die bond thickness, and package thickness caused significant changes in package thermal stresses; whereas changes in lead frame thickness, package width/length and die bond elastic modulus corresponded to minor changes in package stresses. The loss of adhesion at the mold material interface resulted in significantly altered thermal stress fields, e.g., the stresses were concentrated near the corners of the chip and lead frame where cracking has been observed in DIP plastic molding materials.

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The aim of the study was to determine and analyse the costs of harvesting and storage of maize straw for biogas production. The investigations showed that it was the most economical to harvest maize straw with a self-loading wagon equipped with a cutting system and to store it in a field prism. The cost of this technology amounts to €12.5 per Mg d.m. The cost of maize straw harvest with a field chopper and storage in a flexible silo was the highest, amounts to €126.9 per Mg d.m. The research findings can be used for estimating the profitability of harvesting maize straw for energy production and other industrial purposes.

Abstract. The objective of the article was to develop a method of evaluating diagnostic information basing on the existing systems of agricultural tractors diagnostic used in authorized service centers, which will improve of the quality of the evaluation process. Initially, available tractor diagnostic systems were identified in order to gather information about individual diagnostic signals. Following that, the information was verified by empirical evidence concerning a given failure. Thus, the work presents an original evaluation method of the information obtained from the agricultural tractor diagnostic. Obtaining diagnostic information generates certain costs, hence, it is necessary to rationalize and make the processes efficient. Further part of the thesis contains a description and logical verification of the developed method using empirical database. Finally, we presented the method's application for evaluating diagnostic information obtained from the tractor computer diagnostic, in order to examine its effectiveness and for a final verification.The described method of validating diagnostic information creates new cognitive and pragmatic possibilities.