No abstract

Conventional papers are not suitable for printed electronics because they have a rougher surface than the plastic film commonly used for electronics printing. The paper surfaces were modified by coating and calendering processes to reduce surface roughness and electrical resistance of inkjet-printed UHF RFID antennas. The composition of coatings, the main component which included aluminum oxide pigment, had an influence on the surface roughness, the surface pore content and the electrical resistance of the inkjet-printed UHF RFID antennas on coated papers. Papers coated with a mixture containing 25% polyvinyl alcohol binder in combination with the cationic polymer PDADMAC without glyoxal crosslinker had the lowest surface roughnesses and the lowest electrical resistances of the inkjet-printed antennas. As the coating basis weight increased, the electrical resistance of the antennas increased. Reduction of the electrical resistance of the antennas was achieved after calendering coated paper. The design of the antennas had a significant effect on their electrical resistance, which increased with the length of the antenna.

No abstract

Papers for the thermal transfer printing of UHF RFID antennas were prepared by coating and calendering. Real and imaginary components of the impedance of the UHF RFID antennas depended on their design, coating composition and conditions of paper calendering. Passive UHF RFID tags were constructed from antennas and chips whose real and imaginary components of impedance in the 860–960 MHz frequency band were at approximately the same level. The communication quality of passive UHF RFID tags was evaluated by measuring the reading range using the designed UHF RFID reading unit. The reading range of experimental UHF RFID tags with printed antennas on paper and commercial UHF RFID tags with chemically etched antennas on a PET film were identical in the 860 MHz frequency.

Betón je charakteristický rôznorodosťou svojho zloženia -heterogenitou. Predpokladá sa, že heterogénna povaha betónu, v ktorej prevládajú veľké zrná kameniva, riadi proces šírenia trhlín v betóne. V prípade obyčajného betónu pôsobia veľké zrná kameniva ako významné koncentrátory napätia, ktoré usmerňujú priebeh silového toku a ovplyvňujú tak mechanické vlastnosti betónu. Cieľom výskumu bolo analyzovať vplyv početnosti veľkých zŕn kameniva (inklúzií) pri ich asymetrickom usporiadaní na sérií skúšobných vzoriek o troch rôznych veľkostiach. Pozornosť bola venovaná úrovni dosiahnutého medzného napätia skúšobných vzoriek, ktoré boli namáhané osovým tlakom.