An efficient and green protocol for the synthesis of pyrazoles derivatives by one-pot reaction of different 1,3-dicarbonyl compounds with hydrazines/hydrazides has been developed using nano-sulfated zirconia, nano-structured ZnO, nano-g-alumina and nano-ZSM-5 zeolites, as the catalyst. The optical properties of the nano-structured catalysts and organic molecules were studied. The advantages of ...

PURPOSE The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita...

Nano-zirconia is commonly used in dentistry as a framework material over which feldspathic porcelain layered to form an aesthetic and strong bi-layered restoration. Sufficient bonding strength between zirconia frameworks veneering porcelains crucial for the longevity of zirconia-based dental restorations. This study aims determine shear bond (SBS) colloidal-processed slip-casted novel nano-zirc...

This study investigated the contrast ratio and grain size depending on sintering parameters of twelve different zirconia materials and compared with glass-ceramic (N=156, n=12 per group). Contrast ratio of all ceramics was measured using a spectrophotometer according to ISO 2471: 2008. Grain sizes of zirconia were determined by SEM. Data was analyzed using one-way ANOVA followed by post-hoc Sch...

PURPOSE This study aimed to identify the effects of the sintering conditions of dental zirconia on the grain size and translucency. MATERIALS AND METHODS Ten specimens of each of two commercial brands of zirconia (Lava and KaVo) were made and sintered under five different conditions. Microwave sintering (MS) and conventional sintering (CS) methods were used to fabricate zirconia specimens. Th...

Authors reported an effective path to increase the electrical conductivity while to decrease the thermal conductivity, and thus to enhance the ZT value by nano-inclusions. By this method, the ZT value of Nb-doped SrTiO3 was enhanced 9-fold by yttria stabilized zirconia (YSZ) nano-inclusions. YSZ inclusions, located inside grain and in triple junction, can reduce the thermal conductivity by effe...

A process of micromolding, delivering micro- and nanopatterned ceramic surfaces for biomaterial applications is described in this work. To create the desired structures, tape casting of ceramic slurries on microfabricated silicon mold was used. Several tape casting slurry compositions were tested to evaluate the feasibility of transferring micro- and nano-features from silicon molds. Used ceram...

PURPOSE To measure the surface loss of dental restorative zirconia and the short-term bond strength between an indirect composite resin (ICR) and zirconia ceramic after various sandblasting processes. MATERIALS AND METHODS Three hundred zirconia bars were randomly divided into 25 groups according to the type of sandblasting performed with pressures of 0.1, 0.2, 0.4 and 0.6 MPa, sandblasting t...

size reduction of high energy materials such as 1, 3, 5, 7-tetranitro- 1, 3, 5, 7-tetraaza cyclooctane (hmx) has considerable influences on improving their explosive characteristics. in this study, nanosized hmx par­ticles were produced using ultrasonically reprecipitation method by applying water as a safe and accessible antisolvent instead of unsafe conventional methods. sem photographs revea...