Perception of the Harvester Operator’s Working Environment in Windthrow Stands

The aim of the study was to determine the mental workload of a harvester operator when working in late thinning and in windthrown stands of the same type and age, using eye movement patterns as an indicator. Eyeball movement variability was analysed using the eye tracking method. The mean duration of eyesight fixations in windthrown stands was shorter than in the control undamaged stands by about 20% (444 ms and 534 ms, respectively). The mean time of eyesight movements (saccades) in the windthrown stands was shorter than in the control undamaged stands by approx. 15%. The largest differences between the duration of saccades in the windthrown and control stands were observed between the cutting of trees and cutting logs off their root plates: the saccades were longer by about 20% when working in the control stands (49 ms) as compared to the windthrown stands (43 ms). Large differences in the duration of saccades between the windthrown area (42 ms) and the control area (47 ms) were also found when travelling between successive operation sites. In both types of stands, the shortest saccades were observed during processing: 39 ms. Summary durations of saccades observed during the processing of successive trees occurred in sequences showing repeated periods of variable eyeball activity, where longer saccades were followed by shorter ones. Documented more variability of eyesight activities of the harvester operator performing the operations of processing and moving is new standard of eye balls activities for the more taxing work conditions presented by windthrown stands.

High Resistance of SO2 and H2O over Monolithic Mn-Fe-Ce-Al-O Catalyst for Low Temperature NH3-SCR

Monolithic Mn-Fe-Ce-Al-O catalyst with honeycomb cordierite ceramic as a carrier was reported for the first time for low temperature deNOx application. In the reaction of selective catalytic reduction (SCR) of NO with NH3, a NO conversion of above 80% at 100 °C was obtained. Notably, the catalyst also showed excellent resistance against SO2 and H2O. About 60% NO conversion was maintained after successive operation in the mixed stream of SO2 and H2O for 168 h. The Brunner−Emmet−Teller (BET) measurement, SEM, EDS, thermogravimetric analysis (TG), FT-IR, and XPS results of the used catalysts indicated that certain amounts of ammonium sulfate was formed on the surface of the catalyst. XPS results revealed that partial of Fe2+ was oxidized to Fe3+ during the reaction process, and Fe2+ species have strong redox ability, which can explain the decrease in activity after reaction. In addition, SO2 and H2O induced a transformation of Ce from Ce4+ to Ce3+ on the surface of the catalyst, which increased the amount of chemisorbed oxygen. Owing to these factors, the addition of Ce and Fe species contributes to excellent resistance of the catalyst to SO2 and H2O.

Preparation of 4-arylquinazolines with o-(N-alkyl,N-p-tosyl)aminobenzonitriles, aryllithiums, and NIS

Tansformation by successive operation without transition metals.

Possibilities of Reclamation Microwave-Hardened Molding Sands with Water Glass

The paper presents results of a research on identifying opportunities for effective reclamation of waste molding sand with water-glass, hardened by microwave heating. The molding sand applied in the tests was prepared with use of selected type 145 of sodium water-glass. The sand was sequentially processed by microwave hardening, cooling, thermal loading to 800°C, cooling to ambient temperature, crushing and mechanical reclamation. These stages create a closed processing loop. After each cycle, changes of tensile strength and bending strength were determined. Results of the study show that it is possible to activate surface of high-silica grains of waste foundry sand hardened with microwaves, provided that applied are appropriate processing parameters in successive operation cycles.