Protoglobin from Methanosarcina acetivorans (MaPgb) is a dimeric globin with peculiar structural properties such as a completely buried haem and two orthogonal tunnels connecting the distal cavity to the solvent. CO binding to and dissociation from MaPgb occur through a biphasic kinetics. We show that the heterogenous kinetics arises from binding to (and dissociation from) two tertiary conforma...

the biosorption of hexavelent chromium from saline solutions by posidonia oceanica, a marinebiomass, was studied as a function of ph, initial chromium (vi) and salt (nacl) concentrations in batchsystem. the sorbent exhibited the maximal chromium (vi) uptake at ph 2 regardless of the presence ofincreasing salt concentration. equilibrium uptake increased with chromium (vi) concentration up to 250...

in this study adsorption of 1-chloro-4-nitrobenzene (cnb) from aqueous solutions onto multi-walled carbon nanotubes (mwcnts) was surveyed. the effect of some key parameters such as ph (2-10), carbon nanotubes dosage (0.02-0.1 mg/250ml), cnb concentration (2- 16 mg/l), and temperature (20,30,40,50°c) were investigated. the results showed that, the variation of initial ph and cnb concentration ex...

Isothermal melt crystallization kinetics of PVDF was investigated by differential scanning calorimetry. Thin PVDF film has been fabricated by the solvent casting technique using dimethylformamide (DMF). Then, the samples were melted and subsequently crystallized in the range of the crystallization temperature (Tc) between 138 and 145 °C. The crystallization kinetics was derived from Avrami equa...

   A magnetically recoverable adsorbent has been prepared by silica-coated magnetic nanoparticles through an amine functionality (ASMNPs). The ASMNPs were characterized by XRD, TEM, SEM, and FT-IR spectroscopy. It was used as an efficient and economical adsorbent for removing O, O-Diethyl O-[4-methyl-6-(propan-2-yl) pyrimidin-2-yl] phosphorothioate (diazinon) from...

Titanium dioxide nanoparticles surface-modified by 5-sulfosalicylic acid 5-SA-TiO2 were prepared in ethanol by the chemisorption process. The effects of surface improvement on the photocatalytic degradation and adsorption of methyl orange MO were studied in a batch system by considering the various parameters, such as contact time, adsorbent dosage, pH, initial dye concentration and temperature...

The adsorption equilibrium and kinetics of ethanol-water systems on starch-based adsorbents prepared from cassava were undertaken. These include modified cassava starch (MS), cassava starch (CS), cassava pellet (CP), and Cassava shred (AB). The adsorption equilibrium data were best represented by the Langmuir adsorption isotherm. The adsorption kinetics was found to follow second order kinetics...

Palladium (II) coordination complexes catalyze the reaction of alcohols with ketones to yield ethers. During the catalytic cycle, the alcohol adds selectively to the β-carbon (anti-Markovnikov). In this work, mechanism and kinetics for the reaction of methanol with methyl vinyl ketone (MVK), being catalyzed by Pd, has been theoretically investigated in detail. Using quantum mechanical approach,...