5 research outputs found
Water productivity indices of the soybean grown on silty clay soil under sprinkler irrigation
The objective of this research was to compare the effects of different irrigation treatments on soybean [Glycine max (L.) Merr.] productivity and water use efficiency on experimental fields of the Maize Research Institute of Zemun Polje(Serbia), in 2007 and 2008. Four irrigation levels were investigated: full irrigation (I100), 65% and 40% of I100 (I65 and I40) and a rain-fed (I0) system. The crop water use efficiency (CWUE, also known as crop water productivity āCWP), irrigation water use efficiency (IWUE) and evapotranspiration water use efficiency (ETWUE) were used to assess the water productivity of each studied treatment. The efficiency of the same treatment differed between the years as it depended on seasonal water availability, weather conditions and their impact on seed yields. Maximum and minimum yields were obtained in the I65 and I0 treatments, averaging 3.41 t haā1 and 2.26 t haā1, respectively. Water use efficiency values were influenced by the irrigation levels. In general, CWUE values increased with the increased level of irrigation. In both growing seasons, IWUE and ETWUE decreased with increasing the seasonal water consumption and irrigation depth. On average, treatments I40 and I65 resulted in similar or higher CWUE and ETWUE than I100, in both growing seasons. I65 resulted in the highest IWUE, averaged over the two seasons, while I100 had the lowest IWUE. I65 could be proper for the soybean irrigated in Vojvodina when there is no water shortage and I45 could be used as a good basis for reduced sprinkler irrigation strategy development under water shortage
Analiza okvira sa polukrutim vezama pri dejstvu zemljotresa
U ovom radu prikazano je ponaÅ”anje ÄeliÄnih okvira sa fleksibilnim vezama pri
dejstvu zemljotresa. Pored nelinearnog ponaÅ”anja Ävornih veza i geometrijske
nelinearnosti strukture, razmatra se i pojava teÄenja materijala. Polukrute Ävorne veze
predstavljene su pomoÄu nelinearnih rotacionih opruga na krajevima grednih
elemenata, i vezane su paralelno sa viskoznim priguÅ”ivaÄima. Za simulaciju plastiÄnog
teÄenja materijala primenjena je Metoda plastiÄnih zglobova. PlastiÄni zglobovi, koji se
mogu formirati na krajevima grednih elemenata i u bazi stubova predstavljeni su takoÄe
pomoÄu rotacionih opruga promenljive krutosti, koje su sa oprugama polukrutih Ävornih
veza vezane redno. Pored konvencionalne analize dinamiÄkog odgovora, primenjena je i
analiza energetskog odgovora sistema i uspostavljena korelacija izmeÄu odgovarajuÄih
parametara i rezultata ove dve analize. NumeriÄka analiza sprovedena je na primeru
sedmospratnog okvira izloženog dejstvu razliÄitih intenziteta zemljotresa El-Centro