The purpose of this paper is to present the possibility of replacing physical unit cost in transportation or distribution problems by an aggregate coefficient, getting qualitative and subjective considerations involved. The model for constructing aggregate cost is a two stage multiple attribute decision-making problems. In the first stage supply points, demand points and routes of transportatio...

This paper employs a multivariate dynamic conditional correlation GARCH model, which is developed by Engle (2001, 2002), to detect the timing and nature of changes in the comovement between Iranian output and prices for the periods after Iran–Iraq war , known as imposed war . The results showed that there is a weak correlation between output and prices after imposed war and  varies periodically...

introduction: the aim of this study was to compare the chemical compounds of white proroot mineral trioxide aggregate (wmta) hydrated at different ph environments. methods and materials: mixed samples of wmta were kept in acidic (ph=5.4), neutral (ph=7.4) and alkaline (ph=9.4) environments for 48 h. then, x-ray diffraction (xrd) analysis was performed for both hydrated and powder forms of wmta....

introduction: the aim of the present study was to evaluate the biocompatibility of two modified formulations of portland cement (pc) mixed with either titanium oxide or both titanium oxide and calcium chloride. methods and materials: polyethylene tubes were filled with modified pcs or angelus mta as the control; the tubes were then implanted in 28 wistar rats subcutaneously. one tube was left e...

objectives: maintaining pulp vitality is a main goal in restorative dentistry. introduction of pulp capping agents paved the way to eliminate the shortcomings of these materials and obtain successful restorations. on the other hand, nanotechnology is an emerging field of science with increasing use in dental materials. this study sought to assess the effect of addition of nano-tio2, nano-sio2 a...

background and aims. substituting chlorhexidine (chx) for water has been shown to enhance antimicrobial activity of mineral trioxide aggregate (mta). the purpose of this study was to compare the compressive strength of mta mixed with distilled water, 0.12% and 0.2% chlorhexidine. materials and methods. mta was mixed according to manufacturer’s instructions in group i (n = 20). in groups ii & ii...

objective: in a cavity prepared through endodontic surgery, application of a material to provide apical seal and prevent bacterial and tissue exudates is of great importance. the purpose of this study was to compare the sealing ability of biocalex with white mta, gray mta, and amalgam as root-end fillings. materials and methods: sixty-six single-rooted extracted human teeth were cleaned, shaped...

The problems of agriculture and poverty cannot be addressed without reducing the number of workers and their families dependent on land, thereby raising productivity. There are substantial rural-urban and male-female differences in rates of labor force participation, employment, and unemployment, as well as informality of employment that exist within and across South Asian countries. Also, most...