Production of defect free castings requires good understanding of casting characteristics like mold filling ability and volume deficit characteristic. Pin test piece with cylindrical cores proposed by Engler and Ellerbrok was used to study the mold filling ability. Volume deficit characteristics experiments were conducted using the method designed by Engler. Alloy composition, Mold coat and Pouring temperature were considered as process parameters for the present study and experimental plan has been taken up through design of experiments. The alloy composition is most significant in influencing the mold filling ability, where as pouring temperature is for volume deficit. The Correlation Co-efficient value obtained is -0.98901 indicating strong a negative relation between mold filling ability and volume deficit characteristics. Negative values indicate a relationship between mold filling ability and volume deficit such that as values for mold filling ability increase, for volume deficit decrease.
The perceptual text is the one described by means of sense organs and having specific cohesion tools which include among others lexis belonging to the perception modus, so called introductory predicates indicating specific perception acts, synesthetic expressions, the observer as well as spatial and locative syntactems. Text architectonics is determined by the change of the speaker’s position (observer, perceiver), his transition within the text time and space.
Permanent grasslands – according to the Water Framework Directive – are typical water related ecosystems so they largely affect water quality, its cycling and balance and therefore deserve protection. They are an element of landscape structure (ecosystem function or service) commonly considered a factor stabilising environmental changes.
Most threats posed to waters in Poland originate from present cropland structure with its definite predominance of arable lands over grasslands. Agriculture should therefore focus on the improvement of land use structure in order to minimise environmental hazards and to guarantee at the same time optimum economic effects. This could be achieved by turning arable lands into grasslands (where justified e.g. on light soils) or at least by maintaining present grassland area (condition in negotiations with the EU) and management that would consider environmental protection.
Increasing the contribution of grasslands to cropland structure or at least maintaining their pre-sent status quo would help to achieve compromise between the goals of farmers and environmental protection. Purposeful utilisation of ecosystem services, particularly those of grasslands, allows to maintain more intensive farming without environmental hazard. Limited should be only such activi-ties whose intensity exceeds regenerative or buffering environmental capacity e.g. on grounds par-ticularly subjected to water pollution or those included into Natura 2000 network.
The problem of effective gas extraction from Polish shale rocks is an interesting research subject for scientists. A properly selected proppant, which protects cracks from closing during the fracturing process, inestimably contributes to an increase of extraction. Grains of proppant are transported along with a fracturing medium to reach the deepest regions of the crack. The proper support of the crack provides an easy flow of gas, therefore it is important in terms of extraction efficiency. This paper shows the interactions of a proppant grain with the crack surface in shale rock. FEM analysis was conducted to observe the stress region, which is generated as a result of pressing the grain into the crack surface. A model of a sphere which was pressed into the rock model with constant velocity was applied. The received results of stress depend on material properties and a range of proppant grain pressing.