to evaluate the influence of core thickness and fabrication stages on the marginal accuracy of ips e.max press crowns.twenty ips e.max press crowns, 1.5mm thick, were fabricated on metal dies. the crowns had two different core thicknesses, 0.8mm for group a and 1mm for group b, ten for each group. marginal gap was measured after each stage of core fabrication, veneering and glaze firing. the sp...

We consider the problem of finding target vectors for which the nonzero duality gap exists in the problem of convex optimization. An infinitesimal approach to the duality gap analysis of convex problems is proposed. The approach is based on finding the order of smallness and the proportionality coefficient of perturbation function of the original optimization problem. We show that in case of du...

background and aims. in order to fabricate prostheses with high accuracy and durability, soldering techniques have been introduced to clinical dentistry. however, these prostheses always fail at their solder joints. the purpose of this study was to evaluate the effect of gap distance on the tensile strength of base metal solder joints. materials and methods. based on ada/iso 9693 specifications...

in the present work, the structural and electronic properties, and conductivity of (5,5) and (6,6) single walled carbon nanotubes in the ground state have done by using the hartree-fock and density functional theory dft-b3lyp/6-31g* level. delocalization of charge density between the bonding or lone pair and antibonding orbitals calculated by nbo (natural bond orbital) analysis. these methods a...

intergenerational gap refers to the disturbance and crisis in the cultural sequence of generations, which leads to conflict in terms of values and norms between parents and children. until recently, this phenomenon has not been considered a serious issue in iranian society and the continuation of similar thought patterns through the generations has prevented the emergence of distance and variou...

background following the implementation of family physician plan in rural areas, the quantity of provided services has been increased, but what leads on the next topic is the improvement in expected quality of service, as well. the present study aims at determining the gap between patients’ expectation and perception from the quality of services provided by family physicians during the spring a...

sol-gel derived sulfur modified and pure zno nanorod were prepared using zinc chloride and thiocarbamide as raw materials. prepared nanorods were characterized by means of x-ray diffraction (xrd), thermogravimetry- differential scanning calorimetry (tg–dsc), uv- vis absorption spectroscopy, brunauer emmett teller (bet) specific surface area and barrett joyner halenda (bjh) pore size distributio...