fabrication of ultrafine grained materials by imposing severe plastic deformation for improvement of mechanical and physical properties of metals has been the focus of many researches over the past few years. in this process, a sheet is subjected to repetitive shear deformation conditions by utilizing asymmetrically grooved and flat dies through alternate pressing. in this study, a 2mm thick co...

background: this study describes the possibility of implementing three-dimensional printing technology to create a precise construction of a planned bolus, based on computed tomography information stored in the digital imaging and communications in medicine (dicom) format file. materials and methods:  to create the bolus with a 3d printer, we converted data in the dicom format to the stereolith...

in this paper, the influence of the constituent volume fractions by changing the values of the power-law exponent with uniform pressure on the vibration frequencies of reinforced functionally graded cylindrical shells is studied. the fgm shell with ring is developed in accordance to the volume fraction law from two constituents namely stainless steel and nickel. these constituents are graded th...

objective herpes simplex virus (hsv) infection during pregnancy may lead to fetal loss. the aim of this study was to explore the infection rate of hsv type 1 and 2 infection associated with spontaneous abortion in a pilot case-control study in two cities of iran in 2010. patients and methods placenta and curettage samples from 35 healthy full term neonates and 35 cases of spontaneous abortion w...

in this study, the stability problem of a circular orthotropic cylindrical shell under the effect of anaxial compression varying with a power function of time is considered. at first, the modified donnell typedynamic stability and compatibility equations are obtained using love’s shell theory. applying the galerkinmethod and rayleigh-ritz variational techniques to these equations and taking the...

the study determined optimum inventory levels for various bakery resources using the bread supply chain network in onitsha city. structured questionnaires were administered among bakery factories. the optimum design achieved through the optimization model was compared with the existing systems. analysis of 90 bakeries with a combined capacity of 3960 revealed that total money n 564,408,477.28 i...

this study aims to deal with a more realistic combined problem of project scheduling and material ordering. the goal is to minimize the total material holding and ordering costs by determining the starting time of activities along with material ordering schedules subject to some constraints. the problem is first mathematically modelled. then a hybrid simulated annealing and genetic algorithm is...

background numerous factors have an effect on the accuracy of an impression and resultant cast, and these include: impression material, impression technique, tray selection, impression disinfection, storage time of impression before pouring, stone type used for fabrication of cast. up to now, there has been little research conducted on the effect of contact time of a cast with an impression, on...

results significantly high levels of radon gas were found mostly in water and residential buildings. conclusions it conclusion with regard to the study of building materials, granite stone and adobe coverings cannot be recommended for construction purposes. materials and methods the most important route of exposure to such radiation is indoor places. in this investigation measurement of radon i...