introduction: a study model is a precise three dimensional replica of patient’s dentition and plays an important role in treatment planning. many digital multi-media applications have become available to the clinician and his or her staff to facilitate standard procedures in practice and management. the aim of this study is to evaluate reliability and validity of dental measurement made on digi...

parotid stafne bone defect is a very rare and infrequent variant, which is located on the buccal or lingual surface of the mandibular ascending ramus. in this paper, a case of parotid stafne defect, which was incidentally discovered during dental radiographic examination, is reported. this bone defect was observed as a lucent oval-shaped defect on the lingual aspect of the right mandibular ramu...

introdouction: the aim of this study was to compare information regarding pharyngeal airway sizes in adolescent subjects with different malocclusion classes obtained from lateral cephalograms and 3–dimensional (3d) cone-beam computed tomography (cbct) scans. materials and methods: in this prospective cross-sectional study, cbct scans and lateral cephalograms of 35 subjects, taken within one wee...

post-harvest management of potatoes is a major challenge in iran. approximately 30% of the harvest is lostafter a few months of storage. the chemical methods for long term storage are not adequate to controldeterioration and also produce undesirable side effects. to address this issue, a study on radiationpreservation of potatoes was carried out. agria potato bulbs were irradiated using beta be...

air pollutants from iron and steel making operations have historically been an environmental concern. the factory located at ahwaz, iran, has two production lines namely, 630 and 650, which produce iron parallel edge. the objective of the study is to determine indoor respiratory particulate matter (rpm) and feo concentrations and their comparison with niosh standards. this is a cross–sectiona...

introduction: having knowledge about the anatomy of root canal system is essential for success of endodontic treatment. the present study used cone-beam computed tomography (cbct), to evaluate the prevalence of third root in mandibular first molars in a selected iranian population. methods and materials: a total of 386 cbct images from subjects referred to oral and maxillofacial radiology depar...

In this paper, linear stability analysis of non-prismatic beam resting on uniform Winkler-Pasternak elastic foundation is carried out based on Eringen's non-local elasticity theory. In the context of small displacement, the governing differential equation and the related boundary conditions are obtained via the energy principle. It is also assumed that the width of rectangle cross-section varie...

Background: The presence of a wedge filter in the beam trajectory can modify the beam quality and cause some changes in the dosimetry parameters which are usually difficult to be measured directly and accurately. Material and Methods: In this study the MCNP-4C Monte Carlo code was used to simulate the 9 MV photon beam generated by a linear accelerator. Upon getting a good agreement bet...

In this article, transverse vibration of a cantilever nano- beam with functionally graded materials and carrying a concentrated mass at the free end is studied. Material properties of FG beam are supposed to vary through thickness direction of the constituents according to power-law distribution (P-FGM). The small scale effect is taken into consideration based on nonlocal elasticity theory of E...

In this paper, a unified beam theory is developed and applied to study the buckling response of two types of functionally graded sandwich beams. In the first type (Type A), the sandwich beam has a hardcore whereas in the second type (Type B), the sandwich beam has a softcore. In both the type of beams, face sheets are made up of functionally graded material. The material properties of face shee...