First-principles calculations and analysis of the thermodynamic, structural, electronic properties liquid SiO2 characterize bonded-to-atomic transition at 0.1–1.6 TPa 104– 105 K (1–9 eV), high-energy-density regime relevant to understanding planetary interiors. We find strong ionic bonds that become short-lived due high kinetics during transition, with sensitivity temperature pressure, our calc...

The present study revealed a low-cost process for utilizing desert sand preparing nanosilica by sol-gel technique. This work required sodium hydroxide, concentrated hydrochloric acid, distillate water as raw materials, and Iraqi sand. Nanosilica sample was characterized X-Ray Diffraction (XRD), scanning electron microscopy analysis (SEM), atomic force microscope(AFM), surface area (BET) method,...

OBJECTIVES This study investigated the shear bond strength (SBS) and the tensile bond strength (TBS) of the zirconia-to-resin interface using different cement bonding concepts. METHODS Coplanar zirconia specimens were bonded to CoCr-cylinders measuring 5 mm in diameter and 3 mm in height. All bonding areas were first sandblasted with 110 μm Al(2)O(3) (0.28 MPa, 10 s). SBS and TBS were determi...

The aim of the present study was undertaken to investigate the effects of several surface modi cation methods applied to lithium disilicate glass ceramics (LDCs) on their bonding durability with resin-based cement. The LDC specimens were sectioned using a low-speed diamond cutting machine, crystallized by heating in a furnace, and then subjected to several surface modi cation treatments such as...

Separations of the hydrophilic vitamins thiamine (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), cobalamin (B12), ascorbic acid (C), and folic acid have been compared using 14 mobile phases and commercially available, precoated silica gel and chemically bonded silica gel thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) plates. The best separations of i...

Dual-layer and tri-layer broadband antireflective (AR) films with excellent transmittance were successfully fabricated using base-/acid-catalyzed mixed sols and propylene oxide (PO) modified silica sols. The sols and films were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), transmission electron microscope (...