Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the possible complexation of ac...

The Santa Quitéria Project is the major Brazilian uranium mine project, nowadays. A peculiarity of this project is the association of uranium with phosphate and the mining and processing of both by two different enterprises. A private company will be responsible for the production of phosphoric acid and a state owned company will be responsible for the production of yellow cake. At full capacit...

an efficient one-pot oxidation/condensation tandem process has been developed for the synthesis of 2-substituted benzimidazole derivatives from benzylic alcohols and 1,2-phenylenediamine with use of urea-hydrogen peroxide/silica phosphoric acid  as a bifunctional catalyst. this method provides a rapid and efficient access to 2-substituted benzimidazoles.

objective: evaluating the effect of dentin conditioning with edta on microleakage of composite resin restorations, using two etch and rinse and two self-etch adhesives. materials and methods: one hundred and sixty extracted molars received class v cavity preparations right under the cej and were randomly divided into eight groups of 20, usingfour different adhesive systems. these adhesives incl...

Oyster shells have received attention for use as a calcium resource. For this study, calcium phosphate was prepared from phosphoric acid and oyster shells. The influences of the concentration of phosphoric acid and pH in the preparation conditions were studied from the yields of calcium phosphate and unreacted carbonate, and the Ca/P ratios in precipitates. The yield of calcium phosphate and ca...

This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1) 0.1% food grade phosphoric acid; 2) 5.0 mg/L nisin; 3) 0.1% phosphoric acid and 5.0 mg/L nisin; and 4) sterile water (control). The sausages were produced in a pilot plant...

The purpose of the present study was to assess the bond strength of composite resin repairs subjected to different surface treatments and accelerated artificial aging. 192 cylindrical samples (CSs) were prepared and divided into 24 groups (n = 8). Half of the CSs were stored in water for 24 h, and the other half were subjected to C-UV accelerated aging for non-metallic specimens. The treatments...