a mathematical model of sorption of zirconium and hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. sulfuric acid is selected as the eluent for selective separation of zr and hf in a packed bed of dowex cation exchange resin. the column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin bead...

this research was conducted to study the effects of styrene and methyl methacrylate cell lumen monomers on the mechanical properties and decay resistance of beech wood. mechanical and decay resistance test samples were prepared according to astm d143-94 and din en113 standards and impregnated with five concentration monomer solution 0, 40, 60, 80 and 100 percent using bethell method. treated sa...

A solid-phase extraction (SPE) method for sample clean-up and preconcentration followed by reversed-phase high-performance liquid chromatography (RP-HPLC) with uv detection is reported for determination of polycyclic aromatic hydrocarbons (PAHs) in the caspian seawater. A good resolution was obtained using acetonitrile:water (40:60) as mobile-phase for separation of these compounds. The eff...

Acrylic base resins are widely used in orthopedics and dental surgery. It is generally accepted that due to the incomplete conversion of methyl methacrylate (MMA) monomer to the polymer form during polymerization of the resin, some MMA monomers remain in the hardened material. MMA monomer has been reported to cause abnormalities or lesions in several organs of animals. Study of the literatures ...

poly(vinyl acetate) is synthesized via solution polymerization, and then it is converted to poly(vinyl alcohol) by alkaline alcoholysis. the aim of the work study was to investigate statistically the  influence of reaction variables in vinyl acetate polymerization, the conversion of this monomer to polymer, degree of branching of acetyl group in poly(vinyl acetate), as well as the molecular wei...

grafting polymerization was a valuable method for the modification of the chemical and physical properties of polymer surfaces. in this paper, the grafting of cationic vinyl monomer with quaternary ammonium groups, methacryloxyethyltrimethyl ammonium chloride (dmc), onto the isotactic polypropylene (ipp) granule was performed by suspension solid-state grafting process. the technique offers new ...

Periprosthetic Joint Infection (PJI) is a challenging complication after joint replacements, and cement spacers are standard treatment in two-stage revision surgery. This experimental vitro study aimed to evaluate the elution properties of different gentamicin formulations from commercially available intraoperative molded hip spacers. The compared prepared with premixed antibiotic bone cement, ...

1. A systematic procedure for the purification of enzymes by affinity-elution chromatography is described. Enzymes are adsorbed on a cation-exchanger, and eluted with ligands specific for the enzyme concerned. 2. All of the glycolytic and some related enzymes present in rabbit muscle can be purified by the affinity-elution technique. The pH range for adsorption and elution of each enzyme was fo...