SYNTHESIS AND APPLICATION OF CROWN ETHERS

Mono- and bis-benzo-15-crown-5-ether derivatives have been synthesized and determined their potentiometric K+ selectivity factors. Of bis-crown ether urethanes highly selective Iigands were found some of which was used as active ingredient in potassium selective membrane electrode. Sugar based crown ethers, aza-crowns and cryptands were also prepared and applied as chiral catalyst in enantioselective reactions

SAP FLOW RESPONSE OF CHERRY TREES TO WEATHER CONDITION

Sap flow response of cherry trees to weather condition. Themain goal of our study is to measure water-demand of cherry trees budded ontodifferent rootstocks by sapflow equipment and to study the sap flow response to themeteorological factors. The investigations are carried out in Soroksár in Hungary at‘Rita’ sweet cherry orchard. The pattern of sapflow was analyzed in relation ofsolar radiation, vapour pressure deficit and air temperature. Between solar radiationand sap flow was found a parabolic relation, daily pattern of sapflow is in closerelation (cubic) also to vapour pressure deficit. No significant relationship existedbetween sapflow and air temperature. The sapflow performance of sweet cherrytrees on different rootstocks showed typical daily characters