background: excellence and quality models are comprehensive methods for improving the quality of healthcare. the aim of this study was to design excellence and quality model for training centers of primary health care using delphi method. methods: in this study, delphi method was used. first, comprehensive information were collected using literature review. in extracted references, 39 models we...

The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...

petrography, modal analysis of sandstones and major elements geochemistry of shales of early cambrian zagun formation in sarbandan section, central alborz, are used to identify their provenance (including parent rocks, tectonic setting and paleo-weathering). petrography of the sandstones and plotting their point counting data on qt44, f47, l9 and qm44, f45 ,lt11 diagrams imply that they are ark...

Fertility reduction due to sub-fertile males is a major concern in breeder flocks. Phenotypic traits of broiler breeder males and their relationships with fertility can be used as reliable indicators for identification and removal of sub-fertile males from the breeder flocks. This study was conducted to investigate semen traits (semen volume, sperm motility, sperm viability and sperm count) and...