This research comprises a study of the effect of heat treatment on fatigue behavior of (A193-51T-B7) alloy steel. Two heat treatment processes were conducted, namely, annealing and quenching followed by tempering at 200C. All fatigue tests were carried out using a rotary bending machine with constant stress ratio, R=-1. The eddy current probe was used to measure the crack length propagation. Fr...

The purpose of this study was to compare (a) forces generated during lateral compaction and (b) apical microleakage for nickel-titanium (NiTi) and stainless steel (SS) finger spreaders. Twenty-eight extracted human teeth were instrumented using a standardized rotary instrumentation technique. NiTi and SS #30 spreaders were used to obturate molar roots while the forces generated during obturatio...

Methods: Forty disc-shaped specimens were fabricated with a feldspathic porcelain (Super Porcelain EX3), glazed, and randomly divided into 4 experimental groups and 1 control group (n=8/group). For the experimental groups, the glazed layer was ground with a diamond rotary instrument, and the surface was polished with: rubber points (Edenta), steel finishing burs (Meisinger), silicon rubber poin...

This report introduces a novel technique that allows a safe and predictable canal negotiation, creation of a glide path and canal preparation with reciprocating nickel-titanium or stainless steel engine-driven instruments in canals where the use of rotary and the newly developed reciprocating instruments is contraindicated. In this novel technique, the instruments are used in reciprocating moti...

Abstract Rotary straightened structural steel cross‐sections have a different residual stress pattern compared to those without rotary straightening, which affects behavior, especially in members subjected inelastic buckling. A stiffness reduction material model for rotary‐straightened hot rolled sections was previously developed and validated specific set of cross‐section sizes load conditions...

©FFPRHC J Fam Plann Reprod Health Care 2007: 33(4) Chastity belts Chastity belts have been the subject of schoolroom and music hall humour for as long as most of us can remember. But did they really exist and for the purpose suggested? My research started in 2004 with the purchase of a steel chastity belt (Figures 1 and 2). Made of solid steel with sharp spikes on the groin area, padlock plus k...

The purpose of this study was to assess in vitro the efficacy of nickel-titanium K3 rotary files and hand files for removal of gutta-percha and sealer from obturated root canals using either chloroform or chlorhexidine as solvents. Sixty extracted single-rooted bovine teeth with straight, large canals were prepared, obtured and randomly assigned to 3 groups (n=20). The teeth were stored at 37 d...

introduction: the purpose of the present study was to quantify and compare the amount of extruded debris from apical foramen after instrumentation of the root canal system with hand and rotary instruments. materials and methods: root canals of forty five fresh extracted single rooted human teeth with mature apexes and less than 15 degree of root curvature were instrumented in group a with stain...

This work investigates the proportion of generated fines in a pilot-scale experiment using belt conveyor and commercial fuel pellets. For this, with length 3.1 m was used operated at varying conditions: speeds, percentages material loading on belt, two combinations inclination angle falling height, different number handling steps. We considered design experiments approach based response surface...