One of the important parameters in undercut slopes design is the determination of the maximum stable undercut span. The maximum stable undercut span is a function of slope geometry, the strength parameters of the slope material, condition of discontinuities, underground water condition, etc. However, the desired production capacity and therefore the size of excavating equipment will sometimes a...

statement of the problem: impression materials are concerned as a significant source of cross-contamination because of exposure to blood and saliva. purpose: considering the importance of infection control in the dental environments, this study is performed to investigate the dimensional changes of two condensation silicone impression materials, speedex and irasil, after immersion in 0.5% sodiu...

This paper describes algorithms for generating shapes of side actions to minimize a customizable injection molding cost function. Given a set of undercut facets on a polyhedral part and the main mold opening directions, our approach works in the following manner. First, we compute candidate retraction space for every undercut facet. This space represents the set of candidate translation vectors...

STATEMENT OF THE PROBLEM Impression materials are concerned as a significant source of cross-contamination because of exposure to blood and saliva. PURPOSE Considering the importance of infection control in the dental environments, this study is performed to investigate the dimensional changes of two condensation silicone impression materials, Speedex and Irasil, after immersion in 0.5% sodiu...

Restoring a large edentulous space in the anterior maxilla presents many challenges, including how to utilize and manage a deep anterior soft tissue undercut. In the case reported here, a partial denture was constructed that incorporated a semi-rigid exterior flange and a soft liner to help the denture to engage the depth of the undercut. The denture was placed after extraction of the anterior ...

The hypothesis that plastic changes in the efficacy of excitatory neurotransmission occur in areas of chronic cortical injury was tested by assessing short-term plasticity of evoked excitatory synaptic currents (EPSCs) in neurons of partially isolated neocortical islands (undercut cortex). Whole cell recordings were obtained from layer V pyramidal neurons of sensorimotor cortical slices prepare...

Acetylcholinesterase (AChE) levels were determined in control samples of cat cerebral cortex, in partially neuronally isolated (undercut) cortex, and in undercut or intact cortex that had received long-term intermittent electrical stimulation. Assay of AChE activity was based on an automatic titration method using methalcholine as substrate. Tissues from ten of 15 undercut cerebral cortices sho...

Statement of the Problem: Understanding about impression materials, their properties, uses and manipulation can guide operators towards having more successful restorations. Purpose: The aim of this in vitro study was to compare the accuracy of a condensation silicone impression material, Optosil, and an addition poly siloxane impression material, Elite-HD. Materials and Method: A laboratory mod...

This paper develops a theoretical foundation for the undercut-proof equilibrium (see Shy, 1996, 2002; Morgan and Shy, 2013). In a general spatial setting, the set of undercut-proof prices is equivalent the core of a non-transferable utility cooperative-game, played on the set of outcomes that are feasible in Bertrand competition. The result depends critically on two conditions: First, firms mus...

We present a systematic investigation of the dynamic properties of silicon nitride cantilevers in air. The thermal noise spectra of cantilevers have been measured using a home-made optical deflection setup. Torsional and flexural resonances up to the seventh mode are observed. The dependence of resonance frequencies on the dimensions and mode number is studied in detail. It is found that underc...