Objective: Different methods have been suggested to overcome the polymerization shrinkage of composite restorations. Changing the light curing protocol to improve polymerization by using new light curing units is among these methods. The new devices are more efficient, portable and durable and produce less heat. This study aimed to assess the marginal microleakage of class V composite restora...

the present work reports and discusses the results of a 3d simulation of the injection molding process of a rubber compound that includes the mold flling stage and  material curing, using the computer code is developed in “udf” part of the fluent 6.3 cae software. the data obtained from a rheometer (mdr 2000) is used to characterize the rubber material in order to fnd the cure model parameters ...

Recently, the use of high-strength concrete has become more popular due to the availability and significant variety of the admixtures. High-strength concrete increases the load carrying capacity of the columns, therefore, reduces their sizes in buildings and bridges. In bridges, high-strength concrete could result in reduction of number of girders as well as an increase in the span length which...

In order to develop a simple and effective activation method of low calcium fly ash concrete (FAC) and to understand their basic properties, the present paper experimentally investigates the influences of the volume of fly ash (FA), the dosage of the activator (AC) and the water to binder ratio (w/b) on the hydration, setting times and the crack-resistance properties of activated FACs. Results ...

We commercialized Reactive Coke Agglomerate (RCA), a cement-bonded pellet to decrease the thermal reserve zone temperature for the reduction of the reducing agent rate of blast furnaces. To achieve a high productivity of supplying RCA to large blast furnaces, a rapid curing process of RCA using steam was investigated. We obtained rapid curing of RCA within 18 h by combining primary curing for 1...

We report on the control of cyclotrimerization forming a polycyanurate polymer using magnetic iron oxide nanoparticles in an alternating-current (ac) field as an internal heat source, starting from a commercially available monomer. Magnetic nanoparticles were dispersed in the monomer and catalytic system using sonication, and the mixture was subjected to an alternating magnetic field, causing t...

objective: shear bond strength is an important property inherent to the durability of tooth-colored restorative materials namely composite resins. it has been years that halogen light sources have been used for polymerization of composite resins. in recent years light emitting diodes (led) have been introduced for this purpose. with respect to their longer bulb life, needless of a filter and no...