A 25°C, 1 atm total pressure phase diagram for the system SiO2-AlOOH-Fe2O3-H2O, is determined using the Phase Rule and Shreinemaker’s technique as in Chesworth (1974). The waterpresent assemblages so defined are equivalent to a kaolinitic stage of the goethite facies of the weathering zone. As such they constitute the ideal stable assemblages of several earth-surface deposits and the stage can therefore be used to construct models of these deposits.

The effects of hydrothermal conditions on the sorption and fixation of cesium by various clay minerals and shales were investigated. Hydrothermal heating, which may be expected in a radioactive waste repository, altered the clay minerals and shales and led to a decrease in their cation-exchange capacity. Cesium sorption greatly decreased in micaceous vermiculite and in well-crystallized illites containing vermiculite upon hydrothermal treatment at 400°C and 300 bars pressure due to complete layer collapse. However, poorly crystallized illites heated as above showed either a small increase or only a slight decrease in Cs sorption because of partial layer collapse. These studies show that the decrease in Cs sorption is greater in well-crysallized illites than in poorly crystallized illites when treated similarly under hydrothermal conditions. Hydrothermal heating of Cs-sorbed and Cs-saturated samples increased the amount of Cs fixation in all minerals and shales as a result of collapse of the layers. For example, a sample of the Conasauga shale fixed only 18% of sorbed Cs before treatment but fixed 47% after hydrothermal treatment at 200°C and 300 bars pressure. Thus, hydrothermal conditions in a shale repository may be beneficial after leaked radioactive Cs ions are taken up by clay minerals in shales.

The diffusion of water in the title intercalate has been measured by quasielastic neutron scattering. The diffusion coefficient (6.1 × 10−7 cm2 s−1 at 23.5°C) is one order less than that found previously for a sodium-exchanged montmorillonite which, however, contained 4 times as much water in the interlamellar space. The activation energy for the motion has been deduced to be 18 kJ mol−1. Also it has been demonstrated that upon the time scale of the neutron scattering events (faster than 10−9 s) the hydroxyl groups of the clay lattice are not in motion.

Noncrystalline aluminosilicate gels with Al2O3/(Al2O3 + SiO2) weight ratios from 0.3 to 0.5 were reacted in 0.1 N KOH at temperatures varying from 125° to 175°C. The pH of the solutions dropped sharply with increasing gel:solution ratios, indicating that the coordination number of Al in the products changed from IV to VI. The degree of hydrolysis appeared to be higher with KOH than with NaOH. X-ray powder diffraction and infrared spectroscopy showed that disordered kaolinite was the only crystalline product formed. Thermal data and surface area measurements indicated that the kaolinite was formed by a condensation process.

The adsorption-catalyzed degradation of parathion on clay surfaces is a hydrolysis process, proceeding either directly or through a rearrangement step. The rate and mechanism of degradation are dependent on the nature of the clay, its hydration status, and saturating cation. A mechanism for parathion degradation at adsorption sites on clay surfaces, in the absence of a liquid phase, is proposed.

The School Principal introduces readers to a disillusioned and sarcastic teacher who transitions to the role of school principal in a peripheral primary school. Often regarded as a social criticism treatise rather than a work of art, the novella is characterized by the narrator's pervasive cynicism. However, amidst the sarcasm, the principal's actions reveal a surprising undercurrent of compassion, particularly evident in his interactions with children. This article proposes a compassionate reading of the text, positioning it within the framework of childhood history. The narrative, seen through the lens of childhood history, unveils a cultural shift in Iran during the first half of the 20th century, specifically in the realm of education. It explores the complexities of transitioning from child labor to formal schooling and the evolving perceptions of children as innocent, passive, and dependent. A key conflict in the novella revolves around the clash between Iranian patriarchy and the emerging concept of modern childhood. The principal grapples with adapting to a new model that places children at the center of societal and familial concerns. Despite attempts to prioritize children's welfare, the principal struggles to reconcile the demands of patriarchy with the evolving notion of childhood.

Dehydroxylated sericites were stirred in the various salt solutions, or washed several times with various salt solutions using a centrifuge. By these treatments a seriate of the 2M type was easily transformed into an interstratified mineral of the rectorite type when a sericite was treated with sodium salts, and random mixed-layer mineral was formed from 1M sericite. The formation of a rectorite-type mixed-layer mineral from 2M sericite can be explained by the (OH) bond direction after the extraction of the potassium ions.

The adsorption of nitroxide spin probes on smectites solvated in liquids of greatly different polarity was studied using electron spin resonance (ESR) spectroscopy. Adsorbed probes demonstrate various degrees of restricted rotational motion and alignment at the silicate surfaces, depending upon the properties of the solvating liquid. The results are interpreted in terms of direct surface—molecule interaction modified by solvent competition effects. A fraction of the probe molecules is immobilized in many of the solvated clays because of small spacings between platelets. The data indicate lowered reactivity of surface-adsorbed molecules, especially in the case of hydrated smectites.

Aged suspensions of microspheres and two kaolinites exhibit several horizontal layers. Particle concentration is greater at the top of a layer; lower layer tops have increasing particle concentrations. Lower layers also settle more rapidly than upper layers; however, an increase in original suspension concentration results in a proportional increase in the particle concentration of comparable layers and causes comparable layers to settle at a slower rate. The average equivalent diameter of particles within and between kaolinite layers is identical. The maximum measured diameters are also identical. Microsphere layers show similar uniformity of average and maximum diameters. Ultimate settling of layers in suspension does not result in observable layers in the sediment. Data are interpreted as indicating that, in a colloidal suspension, particles interact to become observable as definite horizontal layers. A sequence of mechanisms is proposed for layer formation.