Determination of prestressing levels for cable trusses as a function of their stability
The stability of prestressed cable trusses subjected to static and dynamic loads is analysed in the paper. The stiffness of the elastic cable truss system was varied by changing the prestressing force. Modelling results for different levels of tension show that, in terms of satisfying dynamic resistance conditions, a much greater tensile force is required for cable grids with diagonal members, compared to those with vertical rods. The conclusions derived constitute recommendations for the use of calculation methods, as well as for the determination of prestressing forces under which stability criteria are fulfilled.
Static and dynamic analysis of a spatial catenary
Prikazana je staticka i dinamicka analiza ravninskih i prostornih visecih kabela. U praksi postoje konstrukcijski elementi mehanicko ponasanje kojih se može opisati idealiziranim matematickim modelom ovjesenoga elasticnog kabela. Primjer za to su vlacno optereceni kabeli visecih i ovjesenih mostova. Razumijevanje njihova ponasanja bitno je za analizu stabilnosti ovjesenih konstrukcija. U radu je primijenjen sustav nelinearnih jednadžbi za određivanje inicijalnog oblika kabela.
Carbon Dioxide Elimination from Circle Systems
Ten various circle systems were studied in model experiments. All the experiments were performed using a Waters cannister containing 675–685 g of Durasorbr̀. 300 ml of carbon dioxide were supplied to the system per min. The efficacy of these systems was expressed as the time taken to demonstrate a concentration of 0.6% carbon dioxide in the gas mixture supplied to the patient connection during each respiratory cycle. The carbon dioxide elimination was studied at a gas flow of 2, 4 and 6 1 per min. All the systems showed an effective carbon dioxide elimination for 6 h or more at a flow of 2 1. An increasing efficacy was found with increasing flow, but to a varying extent.