Designed experiments based on a simplex mixture design were employed to explore the effects of three solvent components (water, formic acid, and aqueous acetic acid), extraction time, and extraction temperature for the automated microextraction of basic (cationic) dyes from acrylic fibers. Extractions were conducted by an automated liquid handling system, and dye extraction was evaluated using ...

effects of water on the catalytic performances of movtenbo catalyst in the oxidation of propane to acrylic acid have been investigated at different reaction temperatures and different steam contents. obtained results show that both catalytic performances and catalyst structure are very sensitive to the presence of water vapor in the reaction feed. presence of water induces some structural modif...

The repaired denture base material fractures at the interface of base and repair material. This study evaluated the effect of different chemical treatment of the surfaces on the shear bond strength of conventional heat-cured resin repaired with autopolymerized acrylic resin. The specimens were divided into four groups, 30 specimens each according to surface treatment by chemical etchants Group ...

We describe here the first example of the synthesis of 4-arm star poly(acrylic acid) for use as a water-soluble drag reducing agent, by applying Cu(0)-mediated polymerization technique. High molecular weight 4-arm star poly(tert-butyl acrylate) (Mn = 3.0-9.0 x 10 5 g mol -1 ) was first synthesized using 4,4’-oxybis(3,3-bis(2-bromopropionate)butane as an initiator and a simple Cu(0)/TREN catalys...

BACKGROUND AND OBJECTIVE Chemical cleansing by denture cleansers is first choice for denture plaque control. The most common problems while using denture cleansers are hardening, porosity, odor sorption, water sorption, solubility, and colour change, bacterial and fungal growth. Chemical cleansing procedures have been found to have an effect on the physical and mechanical properties of denture ...

Plastic 60Co buildup caps have been widely used to protect ionization chambers when calibrating high-energy x-ray and electron beams in water, and have been used consistently by the Radiological Physics Center. Recent calibration protocols base their calculations on a theory that assumes that no protective cap is used during calibration in phantom. The change in ionization within the chamber du...

The water characteristics of acrylic denture teeth were investigated under single- and double-pass sliding. The response of acrylic teeth to sliding was that of a relatively ductile material. The wear characteristics were affected similarly by environments of water and saliva. The "enamel" surfaces showed more resistance to penetration and were less susceptible to surface damage than the "denti...

In nature, some organisms have the ability to camouflage adapt environmental changes; they blend with environment by changing their skin colors. Such a phenomenon is of great significance for research adaptive materials. this study, we propose novel design scheme study angle-independent photonic materials and successfully prepare an electrically tunable multi-color display inverse opal gel (IOP...