The transference numbers of the counter ions in montmorillonite paste are determined as a function of the thickness of the water film (h) and of the diffuse double layer (1/κ).

From measured E.M.F. values of a cell with two liquid junction potentials (C′KCl solution-paste-C″KCl solution) and by applying the Henderson equation, the transference numbers t+ were calculated. It is shown that the transference numbers of the counter-ions, t+ → 1 if hκ → 0.

Trioctahedral smectite and regularly interstratified chlorite/smectite in strata of the East Berlin Formation of the Connecticut Valley are largely restricted to black shale and gray mudstone deposited in alkaline, perennial lakes. The precursor of the mixed-layer clay appears to have been a smectite. Alkaline lake waters and inherited pore waters rich in magnesium favored the transformation of smectite to mixed-layer chlorite/smectite by fixation of brucitic interlayers into the smectite unit structure. Gray mudstones containing the mixed-layer chlorite/smectite are invariably underlain by magnesium-rich black shale—a possible source of Mg for the clay mineral transformations. The black shale is composed predominantly of Mg-rich trioctahedral smectite of probable authigenic origin.

A soil of Attica (Greece) has been studied by Mössbauer spectroscopy and magnetization measurements in order to ascertain the nature and form of iron oxides present in it. The room temperature spectra consist of a paramagnetic doublet and a small magnetic sextet. At liquid nitrogen temperature the magnetic component increases considerably at the cost of the paramagnetic component. This behavior is typical of superparamagnetism exhibited by ultrafine magnetic particles. From the values of hyperfine parameters extracted by computer fits of the spectra, the particles can be identified mainly as α-Fe2O3. The theory of superparamagnetism, in conjunction with Mössbauer and magnetization data, is discussed in detail. Application of this theory to the data for the clay fraction of the soil leads to the conclusion that the oxide particles have a size distribution with a mean particle diameter of 131 Å and a width of 14 Å.

One fine spring morning, at some point, I was simply tearing a few sheets of paper towel off a fresh roll. As the sheets came off and the roll rotated about the vertical axle of the holder (Figure 1), I lazily pondered the geometry lurking in the situation. I realised that sometimes I would let the roll rotate as the unwound part moved straight until tearing, while at other times, I might hold the roll in place and unwind the sheets around the roll. More often, it would be some spontaneous combination of the two modes of unwinding.

A reliable method, utilizing a fluoride ion-selective electrode, is described for the determination of fluoride in clays and shales. Interference by aluminum and iron is minimal. The reproducibility of the method is about ±5% at different levels of fluoride concentration.

Data are presented for various clay minerals and for the <2-µm fractions of marine and nonmarine clays and shales. Fluoride values range from 44 ppm (0.0044%) for nontronite from Colfax, WA, to 51,800 ppm (5.18%) for hectorite from Hector, CA. In general, clays formed under hydrothermal conditions are relatively high in fluoride content, provided the hydrothermal waters are high in fluoride content. Besides hectorite, dickite from Ouray, CO, was found to contain more than 50 times as much fluoride (6700 ppm) as highly crystalline geode kaolinite (125 ppm). The clay stratum immediately overlying a fluorite mineralized zone in southern Illinois was found to have a higher fluoride content than the same stratum in a nonmineralized zone approximately 1 mile away. Nonmarine shales in contact with Australian coals were found to be lower in fluoride content than were marine shales in contact with Illinois coals.

It is believed that, in certain instances, peak shifts on DTA curves of similar clay minerals are the result of significant differences in their fluoride content.

Soil samples from near Long Xuyen, South Vietnam, considered to be typical of the clayey alluvial soils of the Mekong Delta, were investigated to determine the soil mineral content and soil type. The soils are of fairly uniform composition, consisting mainly of clay minerals and quartz. the predominant clay minerals including illite and chlorite with lesser amounts of kaolinite and smectite. The small hydrous iron oxide content, indicated by fluorescence background intensity, verified that the soils are not latosols but are clayey estuarine soils amenable to future development as arable land.

The method of specimen preparation enabled direct quantitative analysis of the soil samples by X-ray diffraction with the aid of the results of mechanical analysis and of previous analyses of comparable soil samples from the Delta and nearby areas. A method for the quantitative determination of quartz was used that is independent of the powder crystallite orientation. A study of surface replicas of the soil samples by electron microscopy was made to illustrate the fabric of the soil. The undisturbed soil fabric consists mostly of somewhat randomly-oriented large domains of clay minerals with some blocky quartz particles. Nanno-fossils were present in all samples.

A recently described phenomenon, the shear induced decrease of moisture suction in saturated clay—water systems and its subsequent recovery, has been investigated with the aid of a parallel plate shearing device. The apparatus allowed a more quantitative description of the phenomenon than was previously possible. In 4–6% Na-montmorillonite pastes it demonstrated a well defined suction response to shear oven for shear angles as small as one degree. The observed decrease in suction was rapid at first. It terminated within a few minutes and was followed by an approximately exponential, occasionally incomplete recovery. All the tests carried out exhibited the same general features of suction change.

It is postulated that shear induces a displacement or change in configuration of particles and that subsequently they return to their original states due to thermal motion. The shapes of the recovery curves can be interpreted in terms of the relaxation spectrum functions encountered in linear viscoelasticity theory. By utilizing a characteristic relaxation time for these spectra, rate process theory has been employed to interpret the bonding mechanism in terms of the experimental activation free energy. The results suggest that the bonds which are re-established during the recovery are primarily of the Coulombic type.

Shear induced suction changes should be considered when dealing with deformation theories and structural models of wet soils and clays. Indeed they provide a means of testing certain aspects of soil structure.

The optical spectra of Cu2+ and Ni2+ on Camp Berteau montmorillonite after lyophilization and evacuation at room temperature are characteristic for the presence of Cu(H2O)42+ and Ni(H2O)62+ in the interlamellar space. The most probable ligand field parameters for Cu(H2O)2+4 are Dqxy = 1310 cm−1, Ds = 1807 cm−1 and Dt = 664cm−1. The covalent character of the Cu2+-OH2 bond is not negligible as indicated by the orbital reduction factors k∣∣2 = 0.66 and k⊥2 = 0.76. This is also the case for Ni(H2O)62+ which is characterized by a ligand field strength, Dq = 850 cm−1 and an electronic repulsion parameter B = 920 cm−1. After desorption in vacuum the optical spectra of Cu2+ were poorly resolved, while Ni2+ was present partially as (Ol)3Ni2+, partially as (Ol)3Ni-OH2 where Ol means an oxygen of the hexagonal rings in the tetrahedral layers.

The relationship between scholarship and adjudication has attracted considerable attention in recent years, especially in those areas where significant academic expertise has been developed and academic scrutiny of decisions is common. Yet the role of scholars and scholarship in the context of the adjudicatory practices of the European Court of Human Rights (ECtHR) has remained palpably under-investigated. This article begins to fill this gap in the literature by carrying out the first large-scale empirical study of the use of scholarship by the ECtHR. The authors rely on a purpose-built dataset comprising all the citations made by the Grand Chamber of the Court in judgments and separate opinions appended to it. The study finds that the Court's majority uses scholarship for the purposes of reviewing facts and interpreting international and domestic law but does so rarely. The majority of the ECtHR does not use scholarship to interpret the European Convention on Human Rights or for persuasive purposes, unlike the individual Judges in their separate opinions. Indeed, individual Judges refer to scholarship more often, for more varied and arguably different purposes. This use, however, is inconsistent in terms of both frequency and the types of sources referred to.

Lattice spacings of layer silicates, particularly clay minerals, may exceed 20 Å. The errors in measuring lattice spacings increase rapidly for spacings greater than about 10 Å and diffraction angles 2θ less than about 10°. Long-chain organic compounds, such as normal alcohols, C14–C20, and normal alkanes (paraffins), C26–C30, provide useful calibrations for lattice spacings in the range 10–50Å. The basal spacings of the calibrating substances are determined from their higher order reflections in the angular range where reflections from quartz and silicon are used as standards.

The compound Mg2+-Al3+-(Fe(CN)6)4−, with a structure similar to hydrotalcite Mg6Al2(OH)16CO3 ·4H2O, is prepared by a coprecipitation method. Chemical, thermal, and X-ray analysis of the compound lead to the formula: $(M{g}_{0.741}A{l}_{0.259}(OH{)}_2)((F{e}^{II}(CN{)}_6{)}_{0.067}(C{O}_3{)}_{0.002}(H_{2}O{)}_{1.05})$

The compound is dehydrated at 100° to 250°C, and the adsorption of N2, O2, CO2, and H2 on it is measured at −196°C to room temperature by the volumetric method. The water is removed reversibly from 100° to 200°C, and the interstices after dehyration act as sites of adsorption. When dehydration is carried out at 150°C, the adsorptive activity reaches a maximum. Adsorption isotherms of N2 and O2 at −196°C and of CO2 at room temperature are of the Langmuir type, and the saturated amounts of N2, O2, and CO2 adsorbed are 96.3, 65.2, and 91.8 ml (STP)/g, respectively.

Adsorption isotherms of N2 and O2 at room temperature are of the Henry type. The amount of O2 adsorbed is about 67% of that of N2. The isosteric heats of adsorption at room temperature of N2, O2, and CO2 are 5.1, 4.8, and 11.0 kcal/mol, respectively. A dehydrated product of a Mg2+-Al3+-CO32− compound does not permit adsorption of CO2 at room temperature, but permits the adsorption of H2O. Hence, it has a molecular sieve effect. No adsorption of H2 is observed in any of the compounds tested.

Glauconite pellets in the Cambrian of the central U.S.A. frequently contain two textural forms of glauconite–aggregate and oriented—which differ in both mineralogy and chemistry. The aggregate glauconite composes the bulk of most pellets and consists of crystals in a nearly random arrangement. The oriented glauconite occurs primarily as rims on the periphery of pellets. It has a honeycomb-like structure—the crystals are oriented with their c-axes tangent to the aggregate-textured cores. Scanning electron photomicrographs show that the aggregate and oriented textures grade one into the other.

The aggregate glauconite has a 1 M structure and less than 5% expandable layers, whereas the oriented form has a 1 Md structure and ∼ 10% expandable layers. The aggregate glauconite contains 5–8% more total iron oxides and 2–3% less Al2O3 than the oriented glauconite. The b-cell dimension of individual samples increases nearly linearly with increasing octahedral Fe3+ + F2+ + Mg content. Chemical and crystallographic variations among various samples are, for the most part, related to the ratio of aggregate to oriented glauconite.

The transition between the texture of the aggregate and oriented glauconite suggests that some glauconite pellets may form by concretionary growth. It is proposed that Cambrian glauconite pellets grew through the repetitive development of a smectite-like clay at the margin of pellets. The smectite was later altered, both chemically and texturally, first to the oriented and then to the aggregate-textured glauconite.

The structural formula for K and Mg saturated beidellite was calculated from the total elemental analysis of the < 0.2 μm clay fraction of the B2t horizon of a Mexico soil. The free energies of formation (ΔGfo) of K-beidellite and Mg-beidellite as determined from their apparent solubilities were -2491.3 and -2484.0 ± 3.2 kcal per mole, respectively. The free energies of formation correspond to a clay mineral structure calculated on the basis of a 24 oxygen cell.

The interaction between “unhydrated” cations (those not separated from the surface by a solvent sheath) in hole positions and the montmorillonite surface was analyzed theoretically by considering the main contributions to potential energy from the coulombic, hydration, van der Waals, induced dipole, and repulsive energies. The effects on these energy terms of the distance between the cation and the plane of basal oxygens, h, and of the angle of rotation of the silica tetrahedra, θ, were investigated. Increase of θ with h constant increases the absolute values of all but one of the energy terms. The hydration energy is an exception because it is probably independent of θ. For a small cation, the increase in attraction is greater than the increase in repulsion when the value of θ is sufficiently small. As θ increases, the repulsive energy becomes more and more dominant until a minimum potential energy is reached. For large cations, this minimum can occur only above a certain value of h. Thus, the values of the potential energy minimum and of θ at this minimum depend on the cation under study as well as on h. Since the concentration of unhydrated cations in a montmorillonite-water system increases with decreasing water content, it is concluded that θ increases during the drying of homogeneous montmorillonite-water suspensions. This provides a partial explanation for the changes in b-dimension with water content observed by other investigators.