Mechanochemical reactions of clay minerals with CsCl

Solid state mechanochemical reactions between clay minerals and CsCl during grinding in non-destructive techniques, investigated in our laboratory, are reviewed. Clays were talc, pyrophyllite, sepiolite, palygorskite and minerals from the serpentine-kaolin and smectite groups. No reaction occurred with serpentines, talc, pyrophyllite and palygorskite. Cation-exchange occurred with montmorillonite and saponite. Kaolin-type minerals were delaminated forming disordered aggregates of TO layers with water, Cs cations and Cl anions. XRD did not show any peak but IR spectra proved the presence of H-bonds between water molecules, and inner-surface oxygens or inner-surface hydroxyls. After water thermal evolution CsCl intercalation complexes with a spacing of 1050 pm were identified. Wet-grinding of sepiolite with CsCl resulted in the disappearance of sepiolite XRD peaks indicating a disintegration of the crystal into micro-crystallites with no order in their packing in the particle. Air-grinding of sepiolite with CsCl almost did not change the X-ray pattern of sepiolite

MONOIONIC MONTMORILLONITES TREATED WITH CONGO-RED Differential thermal analysis study

Abstract The adsorption of the anionic dye congo-red (CR) by Na-, Cs-, Mg-, Al-and Fe-montmorillonite was studied by simultaneous DTA-TG. Thermal analysis curves of adsorbed CR were compared with those of neat CR. The oxidation of neat CR is completed below 570°C. Thermal analysis curves of adsorbed CR show three regions representing dehydration of the clay, oxidation of the organic dye and dehydroxylation of the clay together with the oxidation of residual organic matter. The oxidation of the dye begins at about 250°C with the transformation of organic H atoms into water and carbon into charcoal. Two types of charcoal are obtained, low-temperature and high-temperature stable charcoal. The former gives rise to an exothermic peak in the second region of the thermal analysis and the latter in the third region. The exchangeable metallic cation determines the ratio between the low-temperature and high-temperature stable charcoal, which is formed. With increasing acidity of the exchangeable metallic cation higher amounts of high-temperature stable charcoal are obtained. It was suggested that aromatic compounds π bonded to the oxygen plane of the clay framework are converted into charcoal, which is burnt at about 550-700°C. With increasing surface acidity of the clay more species of CR are protonated. Only protonated dye species can form π bonds with oxygen plane and are converted to high-temperature stable charcoal during the thermal analysis. The thermal behavior of the dye complex of Cu-montmorillonite is different probably due to the catalytic effect of Cu

Analyses of the "Gans" Committee Report

This document contains four separate analyses, each with a different author, of the "Gans" committee report on the Bible codes (DP 364 of the Center for the Study of Rationality, June 2004). The analyses appear in alphabetical order of the authors' names. Three of the authors were members of the committee; one, Doron Witztum, is active in Bible codes research. Two of the analyses-by Aumann and by Furstenberg-support the report of the committee; the other two-by Lapides and by Witztum-do not. This document contains material that was generated after the results of the committee's experiments became known; other than reporting the numerical results themselves, DP 364 contains only material generated before they became known.