introduction: the purpose of this study was to evaluate the morphologic surface of gutta­percha cones after cutting with different methods. materials and methods: the apical 3 millimeters of forty standardized, gutta-percha cones size 40 were cut off using scissors or a scalpel against a glass slab. the samples were then examined under scanning electron microscopy (sem) for topographic deformit...

the new non-conventional cutting process by the use of thermal shock is a convenient procedure for cutting the brittle materials such as glasses and ceramics. this method is based on the application of localized thermal shock to brittle materials by the use of hot air jet, which induces thermal stresses at the tip of an existed pre-crack. due to the thermo-elastic behavior of materials, the pre...

Forest managers have traditionally planned harvests using their expert knowledge. This applies mainly to the spatial distribution of harvest units. The amount of timber to be harvested is regulated by market demand. In addition to forest managers’ expert knowledge, there is a set of rules, which can be automatized. Computerized harvest planning will lead not only to saving time of forest manage...

in order to evaluate the effect of different sources and rates of nitrogen the growth and biomass production of purslane, a randomized complete block design was conducted with three replications at the agricultural research farm of shahrekord university in 2012. fertilization treatments were consisted of control (no n amendment), 30 and 90 kg n ha-1in the form of urea fertilizer, 30 and 90 kg n...

Estimation and modeling of soft tissue deformation during cutting is important for developing a reality based haptic interaction model for surgical training and simulation. In this paper, we are interested in understanding the effect of parameter changes, such as the cutting speed and the angle of cutting, to develop a predictive model that is self consistent with the experimental observations....

This article reports the effects of various artificial aging methods and lubrication modes (dry, mist, wet) on the recorded cutting forces and chip morphology in drilling Al-Si-Mg (A356) cast alloys. In the course of this work, the work part sampled were as-received alloy (T0), solution heat-treated alloy (SHT) and then aged alloys at 155°C, 180°C, and 220°C (T4, T6, T61, T7), respectively. The...

Utilization of metalworking fluids in the technological process of metalworking brings its advantages and disadvantages, mainly associated with the contamination of the working air through cutting fluid mist. The primary aim of this article is to approximate the mechanism of aerosols generation which contaminates the working air and to draw the attention to the problem of quantification of gene...

Two types of alumina-based cutting tools with compositions of 90 vol.% Al2O3+10 vol.% ZrO2 and 80 vol.% A12O3+20 vol.% TiC are produced by isostatic pressing and sintering technique. The effects of these additives on the mechanical properties and cutting performance of these materials are investigated. The tool life in both materials is examined under identical conditions on cutting a grey cast...