background and aims. the single-cone technique has gained some popularity in some european countries. the aim of the present study was to compare the push-out bond strength of gutta-percha to root canal dentin with the single-cone and cold lateral compaction canal obturation techniques. materials and methods. the root canals of 58 human mandibular premolars were prepared using modified crown-do...

in this study, the vibration behavior of functional graded (fg) circular and annular nanoplate embedded in a visco-pasternak foundation and coupled with temperature change is studied. the effect of in-plane pre-load and temperature change are investigated on the vibration frequencies of fg circular and annular nanoplate. to obtain the vibration frequencies of the fg circular and annular nanopla...

world population has already exceeded 6.5 billion, out of which about 850 million (13 percent) are undernourished. with the current growth rate, the world community faces even a greater challenge of hunger and food security as the estimated the population will catch 9 billion by the year 2050 with doubled needs for food. at the same time, preservation of biodiversity, stopping deforestation and...

This article analyses the push and pull factors that bring visitors to the Iranian national parks. The study used a structured questionnaire to collect data on these factors and the socio-demographic profile of the visitors. Survey conducted in Boujagh National Park, an area of 3177 hectares located in the north of the Iran, produced 400 questionnaires. The factor analysis identified four push ...