Recycling of aluminum alloys often decrease fluidity, consequently influence the castability of the alloy. In this study, the fluidity of Al-Zn alloys, such as the standard A713 alloy with and without scrap addition has been investigated. The scrap added was comprised of contaminated alloy turning chips. Fluidity measurements were performed with double spiral fluidity test consisting of gravity...

In current casting factories, tilting type automatic pouring machines are often used to pour the molten metal into the mold, with the operator relying on experience, perception and repeated testing to manually determine the pouring velocity. However, seeking an optimum multistep pouring velocity through trial and error results in an enormous number of combinations and is very difficult. For thi...

some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. the present study evaluated the effect of storage time on dimensional stability of three alginates: hydrogum 5, tropicalgin and alginoplast.in this experimental in-vitro trial, a total of 90 alginate impressions were made from a dentoform model using hy...

We describe here a method for estimating the pouring flow rate for tilting-ladle-type automatic pouring systems used in casting industries. To precisely pour molten metal into the mold, controlling the flow rate of liquid flowing out of the ladle is mandatory. However, it is difficult to directly measure the pouring flow rate by using a conventional flow meter, because the flow meter is damaged...

This study evaluated the accuracy of gypsum casts after different impression techniques and double pouring. Ten patients were selected and for each one it was obtained 5 partial putty/wash impressions with vinyl polysiloxane (VPS) material from teeth #13 to #16 with partial metal stock trays. The following techniques were performed: (1) one-step; two-step relief with: (2) PVC film; (3) slow-spe...

OBJECTIVE The aim of this study was to test a new portable vibrator for plaster pouring (developed for this purpose), comparing the effect of its use on the accuracy of working cast of implant-supported restorations to the conventional vibrator. MATERIAL AND METHODS From a master cast with 2 implants, 30 transfer moldings were made randomly and divided into three groups: group I (GI): pouring...

OBJECTIVES Some manufacturers claim to have produced new irreversible hydro-colloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast. MATERIALS AND METHODS In this experimental in-vitro trial, a total of 90 alginate impressions were ...

The formal statements of the lemmas in this appendix, like the axioms in the main text of the paper, are (intended to be) written in a style that could be given directly to an automated theorem checker, after some straightfoward syntactic desugaring. In the text of the proofs here, by contrast, I have followed the (God knows, rigid enough) comparatively informal style of normal mathematical wri...

The curing of fluid resins is performed by pouring the polymer-monomer mixture into molds made of hydrocolloid[1] or special plaster investment[2], before the fluidity of resin mixture disappears. Therefore, it can be said that the fluidity of resin mixture is an important factor which not only determines the pouring time but also is much related to the quality of the products. The viscosity of...