methoxy polyethylene glycol modified magnetite nanoparticles (pegmns) were synthesized and were characterized by scanning electron microscopy (sem), vibrating sample magnetometer (vsm), and x-ray diffraction (xrd) . the adsorption of diazinon onto (pegmns) was investigated by uv spectrophotometry at 236 nm, through batch experiments. the effects of adsorbent dosage, solution ph, contact time, s...

Cu3(BTC)2 (or HKUST-1) is a metal-organic framework (MOF) material that was synthesized by electrochemical method from Cu and benzene-1,3,5-tricarboxylic acid with large surface area high porosity. The influence of some factors on the adsorption ciprofloxacin (CIP) such as pH (4 - 11), initial concentration CIP solution (10 80 mg/L), mass adsorbent (1 5 mg) time 60 minutes) has been studied. re...

A stable numerical solution to the unsolved problem of nonequilibrium growth/evaporation at long time step of multiple dissociating acids (e.g., nitric acid, hydrochloric acid, carbonic acid, sulfuric acid, etc.) and a base (ammonia) is discussed. The solution eliminates most oscillatory behavior observed in previous solutions at long time step. The solution is applicable across the entire rela...

The instruments and materials used in health establishments are frequently exposed to microorganism contamination, and chemical products are used before sterilization to reduce occupational infection. We evaluated the antimicrobial effectiveness, physical stability, and corrosiveness of two commercial formulations of peracetic acid on experimentally contaminated specimens. Stainless steel speci...

A buffer is defined as a compound that in small concentrations can impart a resistance to large pH changes. Common buffers contain two substances, a conjugate base and a conjugate acid. There are acidic buffers that contain a weak acid and the salt of a weak acid (the conjugate base) and basic buffers that contain a weak base and the salt of a weak base (the conjugate acid). The combination of ...

Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design under response surface methodology was applied for optimizing and observing both individual a...

A chemically modified carbon paste electrode with 2-chlorobenzoyl ferrocene (2CBF) and carbon nanotube (2CBFCNPE) was employed to study the electrocatalytic oxidation of ascorbic acid in aqueous solution using cyclic voltammetry, square wave voltammetry and chronoamperometry. The diffusion coefficient (D = 1.42 × 10-6 cm2 s-1), and the kinetic parameter such as ...

Thermodynamics of extraction of Zn2+ from sulfuric acid media contacting to a mixture of DEHPA and MEHPA diluted with 80 wt% aromatic-aliphatic kerosene with a constant DEHPA to MEHPA ratio is investigated at different acidities, concentrations and temperatures. As a result, the extraction reaction is found to be endothermic with a zinc distribution factor that increases with increasing of the ...

Modification of carboxypeptidase A(gamma) crystals (Anson) with diazotized arsanilic acid specifically labels tyrosine 248; at pH 8.2 the modified enzyme gives yellow crystals, but a red solution. It has been suggested that arsanilazotyrosine 248 forms a complex with the Zn cofactor accounting for the red color in solution, but that a complex is not formed in the crystal. However, the crystal s...