The transformation of sodium and potassium smectite into mixed-layer clay was followed in hydrothermal kinetic experiments. Glasses of beidellite composition and the Wyoming bentonite were used as starting materials. Temperatures ranged between 260 and 490°C at 2 kbar pressure, and run times ranged between 6 hr and 266 days.

The course of the reactions was found to be strongly affected by interlayer chemistry. When potassium was the interlayer cation, increasing reaction produced the series: randomly interstratified illite/smectite-ordered interstratified illite/smectite-illite. This sequence is equivalent to that formed in shales during burial diagenesis. With interlayer sodium and temperatures above 300°C, an aluminous beidellite (Black Jack analog)-rectorite-paragonite series was realized. The difference between these two diagenetic families is discussed. Below 300°C, sodium beidellite formed randomly interstratified mixed-layer clay much like potassium beidellite, except that a higher layer charge was required to produce sodium mica-like layers. The higher charge resulted from sodium's higher hydration energy. The difference in hydration energy between potassium and sodium may account for the fixation of potassium rather than sodium in illite during burial diagenesis.

The appearance of ordered interlayering in mixed-layer phases is also related to interlayer chemistry. Ordering formed in sodium clays at high expandabilities, whereas it never appeared in the potassium clays above approximately 35% expandable. The appearance of ordering may be partly related to the polarizing power of the mica-like layers.

Phase diagrams, constructed from the kinetic experiments and from the composition and occurrence of natural clays, are presented for the systems paragonite and muscovite-2 quartz-kaolinite-excess water. This study also reports the first synthesis of a Kalkberg-type mixed-layer clay.

My thesis is that certain non-verbal paintings such as Picasso's Guernica make (simple) arguments. If this is correct and the arguments are reasonably good, it would indicate one way that non-literary art can be cognitively valuable, since argument can provide the justification needed for knowledge or understanding. The focus is on painting, but my findings seem applicable to comparable visual art forms (a sculpture is also considered). My approach largely consists of identifying pertinent features of viable literary cognitivism and then showing how they or close analogues can be applied to non-verbal painting. The two main features are the requirements, first, that the relevant knowledge is provided significantly in virtue of the distinctive essential feature of literary fictions, i.e., their fictionality, and second, that the knowledge stems primarily from the content of the work, not from what the auditor brings to the work. Some ways that literary fiction has been taken to be argumentative are explained, and striking similarities are found between argumentative literary fiction and argumentative painting. Potential objections are addressed, and I examine a proposed way to express, in a schematized format, both the power of an argumentative painting and its relatively simple associated propositional content.

Complexes of n-tetradecylammonium-beidellite with n-alkanols

${\rm{(n - }}{{\rm{C}}_{{\rm{14}}}}{{\rm{H}}_{{\rm{29}}}}{\rm{N}}{{\rm{H}}_{\rm{3}}}^{\rm{+}}{\rm{)_{{\rm{0,44}}}(n - C_{{\rm{x}}}}}{{\rm{H}}_{{\rm{2x}}}}{\rm{+}}{}_{\rm{1}}{\rm{OH) }}{}_{{\rm{1,56}}}{{\rm{\{ M}}{{\rm{g}}_{{\rm{0,28}}}}{\rm{A}}{{\rm{l}}_{{\rm{1,81}}}}{{\rm{(OH)}}_{\rm{2}}}{\rm{S}}{{\rm{i}}_{{\rm{3,56}}}}{\rm{Al}}{}_{{\rm{0,44}}}{\rm{O_{{10\}} }}}^{{\rm{0,44 - }}}}$

The compounds undergo a series of reversible phase transitions

${\beta _1} \rightleftharpoons...\rightleftharpoons{\beta_i}\rightleftharpoons...\rightleftharpoons{\beta_\omega}\rightleftharpoons{\alpha_1}...\rightleftharpoons{\alpha_j}$

The β-transitions correspond to conformational changes of the alkyl chains via rotational isomerisation, especially kink formation. The β-phases become unstable if the kink concentration exceeds 0,14 kinks/-CH2-. The β/α-transition is probably caused by a rearrangement into special gauche-block structures.

Since 1960 asbestos production of the United States has more than tripled, a phenomenon due in large part to the development of the Coalinga asbestos deposit in western California. Although most asbestos ores contain 5–10 per cent chrysotile in the form of cross- or slip-fiber veins within massive serpentinite bodies, no such veins are to be found in the Coalinga deposit despite the fact that it contains more than 50 per cent recoverable chrysotile. The Coalinga ore consists of soft, powdery, pellet-like agglomerates of finely matted chrysotile surrounding blocks and fragments of serpentinite rock. The highly sheared and pulverized nature of the ore favors its exploitation by simple, open-pit mining, and high quality products can be prepared by either wet or dry milling processes.

Four types of serpentine material are distinguishable: (1) hard, dense blocks of serpentinite rock, ranging from fractions of an inch to several tens of feet in diameter; (2) tough, leathery sheets, resembling mountain leather, up to several square feet in size; (3) brittle blades and plates of green serpentine, a few square inches in size; and (4) friable agglomerates of soft, powdery chrysotile containing appreciable amounts of the other three. Chrysotile is the principal component of all the above materials, with the exception of the serpentinite rock which consists mainly of lizardite and/or antigorite, with small amounts of brucite, magnetite, and very short fiber chrysotile. Although chrysotile fibers up to several microns in length are present in the leathery sheets, most Coalinga chrysotile is much shorter and arranged in a swirling mesh or disoriented, tangled fibers, much like cellulose fibers in paper. Fragments of serpentinite gangue are scattered throughout the ore and contain most of the lizardite, antigorite, and brucite. Chemical, electron probe, and X-ray analyses confirm the iron-rich nature of the brucite, a critical factor in the susceptibility of this phase to oxidation in the surface weathering zone. Here brucite either dissolves, leaving behind a residue of brown, amorphous iron oxides, or transforms in situ to pyroaurite or coalingite. Dissolved magnesium precipitates as hydromagnesite immediately above the water table throughout the deposit.

The abnormally high chrysotile content of this deposit is probably a result of the intensive shearing that it underwent during or after emplacement. If the friable, chrysotile-rich ore was produced during this pulverization episode, (1) lizardite and/or antigorite in the serpentinite must have been transformed into chrysotile and (2) brucite must have been removed. It is likely that early-formed lizardite/antigorite dissolved in the ground waters which pervaded the highly sheared body and that chrysotile later precipitated from these waters, coating all available surfaces.

A comparison is made of the ion exchange behavior, towards the cobalt ion, of five sodium montmorillonite clays. The selectivity for the bivalent ion at low cobalt loading is correlated with the average dimensions of the particles in the various clays, as characterized by several methods. The data are interpreted in terms of a higher selectivity of the bivalent ions for the broken bonds located at the edges of the clay crystals. Using a model comprising two areas of different charge densities, the experimental differences in behavior can be predicted reasonably well.

The Maungaparerua halloysite deposit is located on the North Island of New Zealand some 210 km north of Auckland. The halloysite deposit was formed by hydrothermal alteration of rhyolite flow rocks. Superimposed on the hydrothermally altered halloysite is deep intensive surficial weathering resulting from the humid climate on the extreme tip of the North Island. The deposit has been drilled and the cores have been analyzed mineralogically and chemically. Drilling has shown that the deposit is circular or ovate and covers about 350 acres. The altered rocks contain about 50% quartz and fine amorphous silica and 50% of a mix of halloysite, kaolinite, and allophane with a small amount of plagioclase feldspar in the coarse fraction. The upper 8–30m, with an average of 15m, of the halloysite alteration deposit consists of relatively soft clay. Below this soft clay, which is the result of intense surficial weathering, the clay becomes hard and dense. The halloysite and kaolin from this deposit are mined and beneficiated using wet process techniques of dispersion, centrifugation, leaching, dewatering, and drying. The products are used as filler in paper, paint, and plastics and as a ceramic raw material for producing whiteware and fine china. This deposit is unique in that it contains a very high proportion of halloysite in the clay fraction. The detailed geology, mineralogy, geochemistry, and the physical properties of the clay will be discussed.

Hydrazine and dithionite, both of which are strong reducing agents, react differently with various dioctahedral smectites. Both the nature of the reducing agent and the structure of the clay affect the course of the reaction. Hydrazine reduces octahedral Fe3+ efficiently if the mineral has a low tetrahedral charge. The reducing action of dithionite does not depend upon the charge.

The results obtained by different physical methods of investigation suggest that reduction of iron is associated with protonation of an adjacent OH group. The Fe2+ formed is readily re-oxidised but the structural changes occurring on reduction are reversible only when Al-OH-Fe, but not when Fe-OH-Fe associations are involved. Reaction mechanisms are proposed and changes in the distribution of iron in the octahedral sites are discussed.

Accelerated soil erosion from construction sites and the resulting increase in downstream sediment load constitute a significant environmental problem. Laboratory studies indicate that small percentages of hydrated lime or of Portland cement will stabilize clay soils against rainstorm erosion by preventing particle detachment. Coordinated measurements of the size distribution of water-stable aggregates, of pore size distribution by mercury porosimetry and of microstructure by scanning electron microscopy and energy dispersive X-ray spectrometry were used to clarify aspects of the mechanisms responsible for the development of erosion resistance. Attainment of such resistance was marked by aggregation of a significant part of the clay into water stable aggregations of the order of several mm in size and of minimal change in porosity and pore size distribution on exposure to the test rainstorms. At least some of the clay particles in the aggregations appeared to be partly converted to calcium-bearing reaction products and formation of the “reticulated network” variety of calcium silicate hydrate gel linking adjacent particles was demonstrated.

The d(001) spacings for a series of montmorillonite samples containing increasing amounts of Cu(en)32+ were recorded after exposure to 50% humidity, 10% humidity, and air that had been saturated with ethylene glycol. It was found that Cu(en)32+ is too large to fit between the montmorillonite particles and that in those samples with large amounts of ethylenediamine Cu(II) added, the clay platelets are associated with stronger interactions than those with small amounts of Cu(II) complex added.

Infrared spectroscopy and electron spin resonance analysis indicate that the absorbed copper (II) complex is the square planar bis ethylenediamine Cu(II) and that the complex ion is oriented so that the $d_{z^2}$ orbital is perpendicular to the clay surface. The montmorillonite particles may act as ligands and coordinate with Cu(en)22+ ions.

Weathering products formed on surfaces of both potassium and plagioclase feldspar (An70), which were continuously leached in a Soxhlet extraction apparatus for 140 days with 7·21 of distilled water per day at a temperature of approximately 78°C, are morphologically identical to natural products developed on potassium feldspars weathered under conditions of good drainage in the humid tropics. The new products, which first appear as tiny bumps on the feldspar surface, start to develop mainly at exposed edges but also at apparently random sites on flat cleavage surfaces. As weathering continues, the bumps grow outward from the feldspar surface to form tapered projections, which then develop into wide-based thin films or sheets. The thin sheets of many projections merge laterally to form one continuous flame-shaped sheet. The sheets formed on potassium feldspars may then roll to form tubes that are inclined at a high angle to the feldspar surface. Etch pits of triangular outline on the artificially weathered potassium feldspars serve as sites for development of continuous, non-rolled, hollow tubes. It is inferred from its morphology that this weathering product is halloysite or its primitive form. The product of naturally weathered potassium feldspars is halloysite · 4H2O.

The flame-shaped films or sheets formed on artificially weathered plagioclase feldspar do not develop into hollow tubes, but instead give rise to a platy mineral that is most probably boehmite. These plates form within the flame-shaped films, and with continued weathering are released as the film deteriorates. There is no indication from this experiment that platy pseudohexagonal kaolinite forms from any of these minerals under the initial stage of weathering.

This study deals with the analysis of dielectric measurements made on montmorillonites saturated by bivalent cations. These measurements are performed between — 150°C and +30°C at frequencies ranging from 300 to 10,000 Hz. Their interpretation is based on a numerical analysis allowing determination of the dielectric losses due to free charge carriers conductivity phenomena and losses due to relaxation phenomena. The free charge carriers conductivity is due to the movement of protons. It depends very much on the nature of compensating cations and on the water content and seems to be closely related to the characteristics of the swelling.

Two types of relaxation phenomenon are described: a Debye relaxation due to electric dipole rotations and a Maxwell-Wagner relaxation due to heterogeneity effects. The analysis of the first phenomenon leads to the examination of the values of the relaxation time. It appears that the rotations of water molecules are difficult with bivalent cations. This essentially is shown by the high activation energy of the phenomenon. The discussion of these parameters shows that the state of adsorbed water molecules are certainly different as compared to the state of water molecules in ice or in liquid water. The characteristics of the second relaxation phenomenon are closely dependent on the free carriers charge conductivity.

Constitutional courts operate under a framework of formal and informal rules. While formal rules have been extensively studied, our understanding of informal rules remains limited. Courts often rely on internal practices, traditions and unwritten customs developed over time, posing a significant challenge due to their hidden nature. Numerous constitutional courts lack detailed voting protocols in their statutes and internal regulations, leaving essential aspects to the court's discretion, such as, inter alia, the voting order, deliberation style, outcome versus issue voting and tie-breaking protocols. By employing a case study of strategic breaching of informal voting protocols in the Mexican Supreme Court, this article highlights the complexity of enforcing informal voting rules given that external actors may be unaware of them, along with other factors. Even when informal rules are broadly known, certain circumstances may diminish the efficacy of informal sanctions addressing their breach. Thus, key judicial players, such as chief justices or judge-rapporteurs, may take advantage of the informal rules of voting protocols to advance their policy preferences.

Two bentonite deposits having average thicknesses of 10 and 4 ft are exposed within nonmarine strata of Late Cretaceous age along the Battle River near Rosalind, Alberta. They are characterized by scarcity of >44 μm material and variable 44-2 μm and <2 μm contents. Material >44 μm in size in excess of 2 per cent is primarily attributable to secondary calcite, and <2 μm content may be related to the amount of 44-2 μm material that has altered diagenetically from volcanic glass to montmorillonite. Rhyodacite was the probable composition of the parent ash; therefore, the high iron content in one deposit is probably due to diagenesis. The blocking effect of iron on exchange sites can explain differences in exchangeable Na and Ca in different deposits. High exchangeable Na found in finer subdivisions of fractionated clay can be explained by increased purity of the bentonite.

Multiple regression analysis of the analytical data shows that 48 per cent of the variation in yield (bbl/T.) of 15 centipoise drilling mud can be attributed to concomitant variation in seven interrelated compositional properties. Sequential analysis shows that <0·2 μm clay content is the most important contributor to variation in yield. The remaining variables (total clay content, exchangeable Na, exchangeable Ca + Mg, Fe2+ and Fe3+ contents, and CEC) contribute little additional precision to the regression analysis when <0·2 μm clay content is included in the equation.