The effect of V-notches or reentrant corners on fracture propagation has been analyzed for brittle materials, but not for quasibrittle materials such as concrete, marked by a large material characteristic length producing a strong size effect transitional between plasticity and linear elastic fracture mechanics. A simple size effect law for the nominal strength of quasibrittle structures with s...

We perform a case study on the evolution of current sheet in different regions around dipolarization front (DF), including magnetic-dip preceding DF, at and magnetic pileup region (MPR) behind DF based magnetospheric multiscale (MMS) observation July 31, 2017. In this event, MMS1 stays inside during whole bursty bulk flow (BBF) interval. Our analysis reveals that cross-tail is rolled up, signif...

introduction: in open reduction and internal fixation for the treatment of mandibular fracture, the fixation technique used is very important in reducing post-operative complications and promoting the healing process. this study assessed the results of fixation of the mandible using two mini-plates perpendicular to each other in the lower border of the mandible for fracture treatment.    materi...

sudden fracture is one of the major failure modes in brittle materials. plexiglass (polymethyl methacrylate) is a well known brittle polymer, widely used in various industries. many types of notches, particularly v-shaped notches, are sometimes used in the components made of plexiglass. these notches can dramatically decrease the load bearing capacity of components due to the concentration of s...

UNLABELLED PURPOSE OF THE STUDY Although supracondylar humeral fractures represent a major part of the pediatric fractures, no classification system or radiological characteristics describes which supracondylar fractures require open reduction. We aim to evaluate the factors that lead us to perform open reduction during operation. MATERIAL AND METHODS We retrospectively evaluated 57 patients wh...

AIM To evaluate the effect of rotational speed and the angle and radius of curvature of root canals on the fracture of two types of nickel-titanium rotary instruments: K3 and ProTaper. METHODOLOGY A total of 240 root canals of extracted human maxillary and mandibular molars were divided into two groups of 120, according to the angle of the canal curvature (group A: <30 degrees, group B: >30 d...

The more complex the hydrogeological conditions of a mine, likely coal seam is to experience water inrush during mining process, and greater degree hazard. scientific reasonable prediction in mines with great significance safe efficient operation mines. Taking roof problem No. 3 lower Jisan Coal Mine as research object, factors affecting were comprehensively considered from three aspects: aquif...