The extrusion of section from round billet poses a great challenge for theoretical modeling of the process using upper bound method. The greatest difficulty in three-dimensional upper bound method is to determine kinematically admissible velocity field. The SERR (Spatial Elementary Rigid Region) technique is fairly applicable for analyzing extrusion of sections having re-entrant corners. A modi...

Introduction: To investigate Ca(OH)2 extrusion from the apical foramen in relation to the placement mode. Methods: 200 teeth, prepared with ProTaper files with and without apical patency, were divided in Groups A and B respectively, and filled with Ca(OH)2 at 1 and 3 mm short of working length, using K-files manually and with mechanical spiral techniques (Pastinject/Lentulo) at 500 and 700rpm. ...

immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. this study was done to compare the apical extrusion of naocl in an immature root delivered using endovac and needle irrigation.eighty freshly extracted maxillary central incisors were decoronated followed by access ca...

OBJECTIVES The objective of this study was to determine the various factors that affect the extrusion rate of ventilation tubes (VTs), including the nature of the middle ear effusion. METHODS A retrospective chart review of 82 pediatric patients (177 ears) who received VT insertion surgery under general anesthesia was carried out to evaluate the relationship between various factors and the VT...

The control of tissue growth, which is a key to maintain the protective barrier function of the epithelium, depends on the balance between cell division and cell extrusion rates [1, 2]. Cells within confluent epithelial layers undergo cell extrusion, which relies on cell-cell interactions [3] and actomyosin contractility [4, 5]. Although it has been reported that cell extrusion is also dependen...

The objective of this paper is to investigate the viscous shear heating effect on the formation of minimum film thickness in inlet zone of the hydrostatic extrusion process as function of various operating parameters. Minimum film thicknesses in the inlet zone has been evaluated at various extrusion speeds, material parameters, extrusion pressures, and die semiangle for extrusion of low strengt...

This paper presents a new interpretation of the binary blending operator of implicit modeling. Instead of considering the operator as a composition of potential functions, we propose to consider it as an implicit curve extruded in an implicit extrusion field. An implicit extrusion field is a 2D space for which each coordinate is a potential field. The study of general concepts around implicit e...

In the present study the effect of phase volume fraction on the reinforcement of microstructure and tensile properties of composite extrusion process Al6061/SiC has been studied. For this purpose, the base alloy Al6061 using pure aluminum ingots, silicon, of Al-50% Mg, Al-10% Cr and a thin copper rod was prepared. Next, the composite Al6061/5% SiC, Al6061/10% SiC, Al6061/15% SiC and Al6061/20% ...