Kaolinite bioformation at surface conditions: The role of fungi and bacteria.

Experiments aimed at studying the role of microorganisms in the formation of kaolinite from aluminosilicate solutions (Si:Al = 1:1) are reported. The experiments were carried out at room temperature in presence of living microorganisms, Leonardite humic acid, bacterial debris, bacterial exopolysaccharides (EPS), and some organic ligands. The bacterial debris, EPS, Leonardite and organic ligands were chosen to stabilize Al in octahedral coordination for allowing the crystallization of kaolinite.

Direct Observations of Ordered Nanoporosity in Deprotonated 2-(Acetoacetoxy)ethyl Methacrylate (AAEMA) Polymer: Preliminary Results.

Polymers based on 2-(acetoacetoxy)ethyl methacrylate, charged with iron or sodium, were thermally heated at 150 °C. Both polymers were studied and characterized by SEM, TEM, STEM microscopy and SAEDF techniques. The morphological investigation revealed that, upon heating, both polymers were endowed with microholes, sometimes perfectly ordered, whose dimensions varied from 4-5 nm to approximately 500 nm.

Shifts in bentonite bacterial community and mineralogy in response to uranium and glycerol-2-phosphate exposure.

The multi-barrier deep geological repository system is currently considered as one of the safest option for the disposal of high-level radioactive wastes. Indigenous microorganisms of bentonites may affect the structure and stability of these clays through Fe-containing minerals biotransformation and radionuclides mobilization. The present work aimed to investigate the behavior of bentonite and its bacterial community in the case of a uranium leakage from the waste containers.

Modeling the Adsorption of Oxalate onto Montmorillonite.

In this work, a multiscale modeling of the interaction of oxalate with clay mineral surfaces from macroscale thermodynamic equilibria simulations to atomistic calculations is presented. Previous results from macroscopic adsorption data of oxalate on montmorillonite in 0.01 M KNO3 media at 25 °C within the pH range from 2.

In situ observation of biotite (001) surface dissolution at pH 1 and 9.5 by advanced optical microscopy.

Laser confocal differential interference contrast microscopy (LCM-DIM) allows for the study of the reactivity of surface minerals with slow dissolution rates (e.g., phyllosilicates).

Efficacy of Biodanza for treating women with fibromyalgia.

Objective: The objective of this study was to determine the effects of a 3-month Biodanza intervention in women with fibromyalgia (FM).

Design: This was a controlled trial.

Setting/location: The study was conducted at a university research laboratory and social center.

Surface chemistry of K-montmorillonite: ionic strength, temperature dependence and dissolution kinetics.

The surface chemistry of K-montmorillonite was investigated by potentiometric titrations conducted at 25, 50 and 70 degrees C and at ionic strengths of 0.001, 0.01 and 0.

Halobacillus alkaliphilus sp. nov., a halophilic bacterium isolated from a salt lake in Fuente de Piedra, southern Spain.

A Gram-positive, spore-forming, halophilic bacterial strain, FP5T, was isolated from a salt lake in southern Spain and subjected to a polyphasic taxonomic study. Strain FP5T was strictly aerobic. Cells were coccoidal, occurring singly or in clusters.

Haloterrigena hispanica sp. nov., an extremely halophilic archaeon from Fuente de Piedra, southern Spain.

An extremely halophilic archaeon belonging to the order Halobacteriales was isolated from Fuente de Piedra salt lake, Spain. This strain, designated FP1(T), was a pleomorphic coccoid, neutrophilic and required at least 15 % (w/v) NaCl for growth. Strain FP1(T) grew at 37-60 degrees C, with optimal growth at 50 degrees C.

An Experimental Study on the Ion-Exchange Behavior of the Smectite of Cabo de Gata (Almería, Spain): FEBEX Bentonite.

Binary cation-exchange processes (Na-K, Na-Mg, and Na-Ca) have been investigated at 25 degrees C in samples of bentonite from Cabo de Gata (Almería, SE Spain). Exchange isotherms and Vanselow selectivity coefficients indicate that the preference of this bentonite for K(+), Ca(2+), and Mg(2+) ions is greater than that for the Na(+) ion. The change in (i)(j)K(V) as a function of the equivalent fraction of cation M, E(M), is interpreted on the basis of the presence of different types of adsorption/exchange sites (tetrahedral, octahedral, and edge sites).

Adsorption Mechanism and Structure of the Montmorillonite Complexes with (CH(3))(2)XO (X=C, and S), (CH(3)O)(3)PO, and CH(3)-CN Molecules.

The formation of complexes with different ligands in the interlayer space of montmorillonite saturated in Na(+), Mg(2+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Fe(3+), and Cr(3+) was studied. Acetone, acetonitrile, dimethyl sulfoxide, and trimethylphosphate were used as ligands. The nature of the complexes was studied by means of X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, microcalorimetry, and ab initio quantum mechanical methods.

Adsorption of Water Vapor by Homoionic Montmorillonites. Heats of Adsorption and Desorption.

Adsorption isotherms for water vapor, basal spacing, and immersion heats and water desorption heats of Li+, Na+, Mg2+, Ca2+, Cu2+, and Fe3+ montmorillonite are measured at various relative humidities (r.h.).