In this study, a fuzzy logic prediction model for 3, 7, 14 and 28 days compressive strength of lightweight concrete made with scoria aggregate and fly ash under different curing conditions (standard and air curing) was devised. In mixtures containing fly ash, 15% of Portland cement by weight was replaced with fly ash. The specimens were cured in standard curing conditions at temperature 20±2 °C...

OBJECTIVES To verify the effect of interposing different indirect restorative materials on degree of conversion (DC), hardness, and flexural strength of a dual-cure resin cement. METHODS Discs (2 mm-thick, n=5) of four indirect restorative materials were manufactured: a layered glass-ceramic (GC); a heat-pressed lithium disilicate-based glass-ceramic veneered with the layered glass-ceramic (L...

An active approach for initiating rigidization in carbon-fiber reinforced polymer (CFRP) composites unites electrical resistivity to mechanical stiffening. Temperature control is implemented in efforts to reduce the curing time of the composite and to increase control of the curing process. Specifically, proportional-integral (PI) feedback control of internal resistive (Joule) heating establish...

OBJECTIVES Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights. MATERIALS AND METHODS DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were plac...

In order to study the thermal stability of accelerated-curing PF resin, the curing behavior of fresh PF resin was investigated in the presence of single accelerator of methylolurea derivatives (MMU), magnesium hydrate (Mg(OH)2), 25% aqueous solution of sodium carbonate (Na2CO3), and propylene carbonate (PC). Also their optimum combination was added in fresh PF resin. The thermal stability of cu...

AIM The aim of this study was to investigate the influence of light curing method, composite shade, and depth of cure on composite microhardness. METHODS AND MATERIALS Forty-eight specimens with 4 mm of depth were prepared with a hybrid composite (Filtek Z-100, 3M ESPE); 24 with shade A1 and the remaining with shade C2. For each shade, two light curing units (LCUs) were used: a quartz-tungste...

introduction: the aim of this study was to evaluate the influenceof different light curing systems and curing times on the micro-hardness of aresin modified glass ionomer. methods: forty two samples of resinmodified glass ionomer (rmgi) were prepared using stainless steel cylindrical mold(8 × 2 mm) and randomly divided into six groups of seven. three groups werecured with a quartz tungsten halo...

BACKGROUND AND AIMS The aim of the present study was to compare the efficacy of quartz tungsten halogen (QTH) and light emitting diode (LED) curing lights on polymerization of resin composite. MATERIALS AND METHODS A hybrid resin composite was used to prepare samples which were cured using two QTH and ten LED light curing sources. Twelve groups, each containing ten samples, were prepared usin...

Three concrete mix proportions were designed and prepared, respectively, such as fly ash concrete (abbreviated as “FAC”) with 30% fly ash replacement ratio of cement, fly ash, and slag concrete (abbreviated as “FSC”) with each of 20% fly ash and slag replacement ratio and ordinary Portland cement concrete (abbreviated as “OPC”) for the research of carbonation and chloride resistance of concrete...

OBJECTIVE This study evaluated the effect of temperature and curing time on composite sorption and solubility. MATERIAL AND METHODS Seventy five specimens (8×2 mm) were prepared using a commercial composite resin (ICE, SDI). Three temperatures (10°C, 25°C and 60°C) and five curing times (5 s, 10 s, 20 s, 40 s and 60 s) were evaluated. The specimens were weighed on an analytical balance three ...