OBJECTIVE A low-viscosity resin (infiltrant) was used to inhibit the progression of white spot lesions (WSLs) and resolve associated esthetic issues. An alternative pretreatment was explored to increase the pore volume of the surface layer of the WSLs. Also, the penetration effects of the infiltrant were evaluated for various pretreatments. METHODS Sixty two artificial lesions were fabricated...

Speciation of copper in a contaminated soil during electrokinetic remediation (EKR) assisted by H3PO4 was studied by in situ X-ray absorption near edge structural (XANES) spectroscopy. The least-square fit of the XANES spectrum showed that CuCO3 (68%) and CuCl2 (32%) were the major copper species in the contaminated soil. In the presence of H3PO4 (40%), most of CuCl2 and about 24% of CuCO3 were...

BACKGROUND A new and efficient method have been developed for the synthesis of different indole derivatives from various ketones, having at least one hydrogen atom attached to each of their α-carbon atoms, and hydrazines in solvent-free conditions, using marine sponge/H3PO4 as a naturally occurring chiral catalyst. OBJECTIVES This study recommended the use of marine sponge/H3PO4 as a naturall...

Urea-formaldehyde resins modified by melamine were synthesized by four catalysts (H2SO4, HCl, H3PO4, and NaOH/NH4OH) with a F/U/M molar ratio of 1.38/1/0.074. Resin structure and thermal behavior were studied by C-NMR and DSC techniques. For H2SO4, HCl, and H3PO4 catalysts, resins were prepared by two stage pH adjustment: the first pH stage was set at 1.25 (H3PO4 pH 1.60) and second pH stage wa...

Luffa was evaluated as a potential energy crop. A considerable amount of luffa sponge biomass can be grown in a vertical direction with approximately 70% polysaccharide content and low lignin content. When concentrated H3PO4 was employed to pretreat luffa sponge, hemicelluloses were the most sensitive component, followed by cellulose and lignin. Hemicellulose solubilization and cellulose loss p...

PURPOSE The goal of this in vitro study was to identify the topographical features of the enamel surface deproteinized and etched with phosphoric acid (H3PO4) compared to phosphoric acid alone. MATERIALS AND METHOD Ten extracted lower first and second permanent molars were polished with pumice and water, and then divided into 4 equal buccal sections having similar physical and chemical proper...

Solvent extraction using organic solvents is an important technology for the purification of wet process phosphoric acid (WPA). In this study, the purification process of WPA, using a new type of solvent extraction system, cyclohexanol diluted in kerosene, was investigated. The equilibrium phase diagram of the system H3PO4 H2Osolvent mixtures at 313.2K was obtained. The effects of extraction ...

A solid acid membranes based on poly (vinyl alcohol) (PVA), sodium bromide (NaBr) and phosphoric acid (H3PO4) were prepared by a solution casting method. The morphological, IR, electrical and optical properties of the (PVA)0.7(NaBr)0.3(H3PO4) x M solid acid membranes where x = 0.00, 0.85, 1.7, 3.4, 5.1 M were investigated. The variation of film morphology was examined by scanning electron micro...

Karbon aktif adalah suatu bahan yang mengandung unsur karbon 85-95% dan merupakan padatan berpori. ini hasil pemanasan pada suhu tinggi tetapi tidak teroksidasi. Pada penelitian digunakan Kulit Dalam Biji Kopi aktivatornya berupa KOH H3PO4. Adapun tujuan untuk mengkaji pembuatan Aktif dari dengan Variasi Konsentrasi Jenis aktifator berbeda, menganalisa kadar air, abu, terikat, daya serap terhad...