We studied relaxation by hygroscopic expansion of the interfacial polymerization shear stress of bonded resin composites. In the experimental set-up, resin composite-cured-to-glass strips bent due to the polymerization shrinkage. The strips were stored wet or dry. The curvatures of the bent strips were recorded, by the scanning of the glass surfaces with a contact profilometer, periodically ove...

SINCE the discovery of the phenomenon of hygroscopic expansion of dental casting investments when subjected to an environment of water, there has been considerable work carried out to investigate its behavior. The ultimate goal is to develop a technic based on this property capable of compensating for the casting shrinkage of dental gold alloys. The result of these efforts has been the establis...

The purpose of this study was to characterize three base/liner materials in the initial stage of setting, i.e., dual-cured (light-activated glass ionomer), light-cured (light-activated glass ionomer analogue), and chemically-cured (conventional glass ionomer) materials. Changes in dimension, weight and flexural strength were examined from immediately after setting to the end of one week followi...

A study was completed to improve the ability for the designer to account for two-dimensional hygroscopic effects in design analysis while considering a variety of applicable temperature and humidity environments. A literature review was performed to better understand published ISO and ASTM testing specifications and other established methodologies for determining the necessary material properti...

OBJECTIVE To measure the long-term linear hygroscopic expansion (LHE) of several materials using bulked and layered techniques. MATERIALS AND METHODS Seven materials were used; Fuji Cap II, Fuji II LC, Photac-Fil Aplicap, Vitremer, Dyract, Tetric and Z100. Ten specimens (6×4 mm) were made for each material using layered and bulked techniques (each group comprises five specimens). The specimen...

Groundwater-induced deformation of natural rock slopes is typically interpreted to be related changes in pore pressure. Rock, however, a porous medium that has been shown expand on contact with water. Here, we present insights into surface free-standing 115 × 65 35 mm granite prisms water continuously infiltrating from the upper over 16 – 24 hours under ambient laboratory environmental conditio...

The hygroscopic growth of the atmospheric aerosol is a critical parameter for quantifying the anthropogenic radiative forcing. Until now, there has been a lack of long term measurements due to limitations in instrumental techniques. In this work, for the first time the seasonal variation of the hygroscopic properties of a continental background aerosol has been described, based on more than two...