Soil Management Technologies and Mycotoxin Contamination of Wheat and Barley Grain

Fusarium head blight caused by a complex of Fusarium species is widespread across the world and ranks among the most serious diseases in cereals. Long-term field experiments were set up to evaluate the effects of preceding crop and soil management methods on Fusarium mycotoxin (DON, deoxynivalenol) contamination of winter wheat and spring barley grain. Winter wheat and spring barley were cultivated at two locations in the Czech Republic (A: Ivanovice na Hané during 2002–2014, and B: Žabčice during 2007–2014) with preceding crops (A) alfalfa, maize, and pea; and (B) alfalfa (only for wheat), sugar beet (only for barley), and maize. Different soil management methods also were used: (A) 22 cm tillage, 15 cm tillage, 10 cm chisel, and direct drilling; and (B) 22 cm tillage, 10 cm chisel, and direct drilling. Mycotoxin content in harvested grain was analysed using ELISA. At both locations in the experiments with both wheat and barley, year had a significant effect on mycotoxin content in grain. Preceding crop was another significant factor in wheat experiments at both locations, with DON content in grain higher with maize as the preceding crop than in the cases of other preceding crops. Soil management method had a significant effect only on mycotoxin content in wheat grain grown at Žabčice, and the highest DON content was determined in the chisel variant, in which case a large amount of harvest residue remained on the soil surface or was only partially incorporated

Influence of steel structure on machinability by abrasive water jet

Although the abrasive waterjet (AWJ) has been widely used for steel cutting for decades and there are hundreds of research papers or even books dealing with this technology, relatively little is known about the relation between the steel microstructure and the AWJ cutting efficiency. The steel microstructure can be significantly affected by heat treatment. Three different steel grades, carbon steel C45, micro-alloyed steel 37MnSi5 and low-alloy steel 30CrV9, were subjected to four different types of heat treatment: normalization annealing, soft annealing, quenching and quenching followed by tempering. Then, they were cut by an abrasive water jet, while identical cutting parameters were applied. The relations between the mechanical characteristics of heat-treated steels and the surface roughness parameters Ra, Rz and RSm were studied. A comparison of changes in the surface roughness parameters and Young modulus variation led to the conclusion that the modulus was not significantly responsible for the surface roughness. The changes of RSm did not prove any correlation to either the mechanical characteristics or the visible microstructure dimensions. The homogeneity of the steel microstructure appeared to be the most important factor for the cutting quality; the higher the difference in the hardness of the structural components in the inhomogeneous microstructure was, the higher were the roughness values. A more complex measurement and critical evaluation of the declination angle measurement compared to the surface roughness measurement are planned in future research.Web of Science1319art. no. 442

Hydrogen Embrittlement of Welded Joint Made of Supermartensitic Stainless Steel in Environment Containing Sulfane

The work is focused on evaluation of resistance of the welded joint made of supermartensitic 13Cr6Ni2.5Mo stainless steel to sulfide stress cracking. Testing method A and solution B in accordance with NACE TM 0177 were used. All the testing samples were ruptured in a very short time interval but welded joint samples were fractured primarily in the weld metal or in heat affected zone and not in the basic material. Material analysis of samples were made with use of a ZEISS NEOPHOT 32 light microscope and a JEOL 6490LV scanning electron microscope

Academy of Sciences of the Czech Republic

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