Contemporary bio-ethics shares with the ancient tradition of natural theology the characteristic of assuming, in the face of the advances of a fundamentally materialist science, an opportunistic function, which is that of the adaptive rescue of spiritual values. Bioethical humanism exists only in the process of this perpetual movement of repossession, and its effort, established to this effect, leads back incoherently to the interminable dualistic confrontation between science and conscience, having failed to take upon itself the task of constructing a rationally-informed thinking on the relationships between the order of development of positive knowledge and the order of development of moral feelings, both in human evolution and in the history of societies. These matters hardly concern today's fashionable philosophers, whose dominant preoccupation seems to be to find a still-unfilled job - something between an esoteric magus and a preacher in vogue - on the great stage of the inessential upon which inconsequential thought is exhibited.

Analytical electron microscopy was used to confirm the location of pillars of zirconia in pillared montmorillonite. Data show that the pillared clay is of “high” quality, with surface areas ranging from 200 to 250 m2/g and (001) spacings in the 17–18 Å range. The zirconia-rich pillars were observed using bright-field imaging, annular dark-field imaging, and energy-filtered imaging. The composition of the pillars was confirmed by performing nano-analysis using energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy. The pillars apparently have an irregular shape <50 Å in size. The shape and relatively large size of the pillars suggest that zirconia dispersion is not ideally distributed in this sample. This study is apparently the first report of electron microscopy observation of pillaring material in clays.

“All men naturally desire to know” : this is the celebrated assertion with which Aristotle begins the first book of his Metaphysics. According to him, human beings’ desire to know is as natural to them as their desires for food, rest, or amusement. These latter “natural” urges are responses to certain deficiencies—hunger, tiredness, and boredom; similarly, the desire to know is a response to a deficiency of knowledge. As Thomas Aquinas puts it, the urge to know (libido sciendi) is as much a characteristic of human beings as the urge to feel or to dominate (libido sentiendi and libido dominandi), and all three, essential though they may be to human nature, must be kept under control. My purpose here is to examine the limits of the desire to know: in what way may our desire to know go beyond the bounds of the “knowable”?

‘Siberian hunters have never been able to get used to our insistence on pressing our God on everyone else, nor to our way of abasing ourselves before him when they see us as masters of all - conquering the bear and the elk with our rifles, using our knowledge and power to conquer the indigenous people, who have always been determined to hang on to what little they have. How crazy the shaman would be to put his penny in the collection during mass without knowing whether it would be effective or not, whether the ritual would “work” this time - since only the result, here and now, matters to him. Why thank the priest and his God, why let them prosper, when in the end the famine did take hold and the sick did die?’

Siltstones from the Precambrian Freda Formation in Wisconsin have been studied by scanning, scanning-transmission and analytical electron microscopy (SEM, STEM and AEM), and X-ray diffraction (XRD). XRD data for drill core samples show a change from smectite-rich Illite-Smectite (I-S) in shallow samples to illite in deeper samples, implying a transition during burial diagenesis.

Transmission electron microscopy (TEM) observations of shallow samples reveal the presence of three clearly distinguishable kinds of dioctahedral clay minerals: (1) detrital grains of micrometer-sized, mature muscovite; (2) small packets in the matrix consisting of dominant (Reichweite) R1 I-S or (3) small packets of illite. The illite and I-S stacks occur separately and have similar textures, with packet thicknesses averaging ∼400 Å, within the range of anchizonal illite. Illite and detrital muscovite commonly display strain features typical of the effects of tectonic stress. Void space within I-S or illite packets is inferred to be a strain feature, and to have served as pathways for fluids. Detrital muscovite shows abundant alteration features including (001) boundaries which are continuous with parallel packets of I-S; individual layers commonly show along-layer transitions of muscovite to smectite or I-S. Trioctahedral clays consist primarily of detrital chlorite which commonly shows direct alteration to R1 I-S and smectite, as with detrital muscovite.

Deep samples contain only unaltered, coarse detrital muscovite, and thin packets of illite forming stacks and comprising most of the matrix. The texture of the illite appears to be identical to that of shallow samples, with characteristics such as packet size typical of anchizonal illite. Trioctahedral clays consist almost entirely of detrital grains of chlorite and corrensite. They occur as separate grains with rather constant composition, without signs of alteration.

The data imply that all of the studied rocks have been subjected to a uniform anchizonal grade of metamorphism in which detrital grains were largely unchanged but matrix clays were transformed to packets of illite. The unusually abrupt transition with depth from highly expandable I-S to illite is inferred to actually be the result of subsequent alteration of authigenic illite and detrital chlorite and muscovite to R1 I-S and smectite in shallow rocks. This late overprinting of the anchimetamorphic clay mineral assemblage is inferred to have been locally caused by fluids with temperatures less than those of peak metamorphism. This process, called “retrograde diagenesis”, gave rise to a sequence of dioctahedral I-S and illite which mimics classic prograde sequences. Interpretations of such sequences as being prograde, especially in cases of ancient rocks, should be interpreted with caution when high-resolution images of textures are not available.

It is usual in Mössbauer spectroscopy analysis to take the subspectra areas as a measure of the concentration of the Fe compounds that generate them. In soils, the presence of different-size particles of different nature makes the semiquantitative Mössbauer studies difficult, and some handling of the sample must be carried out in order to get reliable area results (Bowman et al. 1967; Muir 1968; Williamson et al. 1981).

An environmental infrared microbalance (EIRM) cell was used to study H2O sorption on two montmorillonite samples as a function of water content and type of exchangeable cation. The vibrational spectra showed that H2O sorbed to the clay at low-water content was strongly influenced by the exchangeable cation and by the close proximity to the clay surface. At water contents <6 H20 molecules per exchangeable cation, the H-O-H bending mode of H2O (v2 mode) shifts to a lower frequency and is characterized by an increase in molar absorptivity. In contrast, the positions of the asymmetric and symmetric OH-stretching modes of sorbed water (v1 and v3 modes) shift to higher energies. These observations indicate that H2O molecules sorbed to the clay surface at low-water content are less hydrogen bonded than in bulk H2O. In addition, the vibrational-stretching and bending bands of the structural OH groups of the 2:1 layer are also strongly influenced by H2O content and type of exchangeable cation. By using the EIRM cell, the molar absorptivities of the structural OH-bending vibrations were measured as a function of H2O content. The position and molar absorptivity of the structural OH-bending bands at 920, 883, and 840 cm-1 are strongly influenced by H2O content and type of exchangeable cation. The molar absorptivity of the 920-cm-1 band, which is assigned to the AlAlOH group, decreased strongly at low-H2O content. This reduction in intensity is assigned to a dehydration-induced change in orientation of the structural OH groups resulting from the penetration of H2O molecules into siloxane ditrigonal cavities that are not associated with a net negative charge from isomorphous substitutions.

The orientation of TMPA cations on montmorillonite affects the adsorbate-accessible siloxane surface area and determines whether the TMPA phenyl ring can interact with other aromatic adsorbates by π-π interactions. The purpose of this study was to determine the orientation of TMPA ions in the interlayer of normal-charge and reduced-charge Wyoming montmorillonite. The orientation of TMPA's phenyl group was investigated using infrared dichroism of selected aromatic ring vibrations. X-ray diffraction (XRD) and MacEwan Fourier transforms were used to determine interlayer spacings and to ascertain whether reduced-charge Wyoming montmorillonite is a randomly interstratified mixture of layers with two different d-spacings. For normal-charge montmorillonite, the infrared results showed that the C-N bond axis is neither perpendicular nor parallel to the surface, yet X-ray data suggested that the TMPA phenyl ring is perpendicular or nearly perpendicular to the siloxane surface. In this orientation, the average adsorbate-accessible space between adjacent TMPA ions is 24 Å2, or about 1/3 of the total surface. When the phenyl ring of TMPA is perpendicular to the clay surface, aromatic compounds should be able to interact with TMPA's aromatic ring by π-π interactions, while polar compounds such as water can interact with positively charged nitrogen atom. The reduced-charge montmorillonite used in this study is a randomly interstratified mixture of about 25% collapsed layers with no adsorbed cations and 75% expanded layers that are propped open by TMPA's methyl groups, not by the aromatic ring. The adsorbate-accessible surface area on expanded layers of reduced-charge montmorillonite is 1.5 to 2 times that on normal-charge TMPA-clay, depending on the orientation of TMPA's aromatic ring.

On our planet only the American continent has had the privilege, or the unhappiness perhaps, of being subjected to a sort of accounting of “anniversaries” or, let us say, “centennials.” But this does not mean, for all that, that these anniversaries serve to commemorate its birth. Geologists tell us the continents were formed hundreds of millions of years ago, making the commemoration of the American continent relatively recent. Moreover, the origins of this custom are foreign to it and are imbued, it must be said, with perspectives that are by all evidence “Eurocentric.” Curiously, no one took any notice of the first or the second centennial of the American continent.

Two essays have been placed under this title. The first is written in the spirit of continental European moral and political philosophy. Its emphasis is on the tensions and paradoxes inherent in the idea of tolerance. The first paradox: the possibility of tolerance, far from being based on the renunciation of the absolute nature of the conviction, depends on the contrary on the capacity for absolute engagement which itself gives rise to an unconditional right towards respect. Another paradox: while, in the case of scientific truth (rational or empirical), understanding and consent coincide, in the case of belief (moral, religious, or aesthetic), there is a striking divergence between the contestable nature of the affirmation and the risky nature of the attachment; but such is the cost of the unconditional. An extreme paradox: it is at the very heart of the idea of truth that a split between possessing and sharing must be operated; and it is then in the realm of dispossession and nonknowledge that the art of mimicking an opposed conviction within oneself - ultimate bulwark against the temptation to impose one's own portion of truth on others - can be learned. The spirit of Karl Jaspers permeates this lucid meditation.

Utilizing high-resolution transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) and X-raydiffraction (XRD) techniques, we have studied the transition from shallower smectite-rich mudrocks to deeper illite-rich mudrocks in Pliocene-age turbidite sediments from the northern Gulf of Mexico (GOM). Our objective in this work was to better understand how the smectite-illite transition may affect the onset of geopressuring in GOM sediments. The samples studied were sidewall cores from an offshore Louisiana well. In previous studies of GOM sediments, the smectite-to-illite reaction has mainly been documented in considerably older, Miocene-age sediments.

The results of this study elucidate the reaction mechanisms entailed in the transformation of clays in this sediment from smectitic to illitic. We found that illite formed at the expense of smectite in 2 ways: 1) growth of preexisting discrete illite flakes, and 2) creation of new illite layers within mixed-layer illite-smectite. Also, illitization apparently proceeded via a dissolution/precipitation, Al-conserving reaction rather than a solid-state, layer-conserving reaction. Smectite illitization is commonly believed to require input of K from feldspar dissolution. Our XRD results found little correlation between decreases in K-feldsparand increases of illite. However, in 1 instance TEM/EDS analyses indicated the presence of high-charge smectite, which suggests that insufficient K was available for illitization. TEM images also show small packets of authigenic chlorite in illite-rich mudrock. This chlorite may act as a sink for Fe liberated upon smectite illitization.

Hydrothermal treatment of a mixture of silicic acid, cobalt chloride, sodium dithionite and sodium hydroxide at 250 °C under 500 psi of argon produced a pink solid. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and electron diffraction data showed the product to be a well-crystallized smectite. SEM/EDX analysis gave a unit cell formula of [(Si8.05)(Co5.58)O20(OH)4]Na066. Heating the same mixture at 150 °C without argon gave a less well ordered smectite of composition [(Si7.93)(CO5.92)O20(OH)4]Na0.42. Two peaks were observed in the cyclic voltammograms of electrodes modified with films of these two clays recorded for the blank electrolytes in the absence of any adsorbed electroactive species. The first peak was attributed to the oxidation of a small fraction of the Co2+ sites within the clay lattices to Co3+. The second peak was assigned to further oxidation of these Co3+ to Co4+.

X-ray diffraction studies of the pore-lining chloritic mineral from the Tuscaloosa Formation disclose a marked pattern of odd-order line broadening for the 001 to the 00,16 reflections. The odd-order peaks are approximately twice as broad as the even orders after correction for instrumental broadening effects. These results are consistent with a randomly interstratified 7-Å/14-Å structure, which is most likely serpentine/chlorite. Quantitative analysis of line broadening and model calculations indicate that the serpentine/chlorite contains 7% serpentine layers.

A simplified method is proposed for quantifying randomly interstratified serpentine/chlorite. Residual line broadening (βr) is obtained from the half-height widths of uncorrected diffraction profiles for the 004 and 005 “chlorite” reflections by means of the following:

${\beta }_r=({\beta }_{005}^{1.25}-{\beta }_{004}^{1.25}{)}^{\frac{1}{1.25}}.$

$\mathrm{\%}S=-0.51+24.27{\beta }_r,$

The changes in amount and location of layer charge during diagenetic alteration have been investigated for smectites and smectite layers of illite/smectite interstratified minerals (I/S) by X-ray powder diffraction analysis with various expansion behavior tests: 1) ethylene glycol (EG) solvation (XRD); 2) K-saturation and EG solvation; 3) Li-saturation, heating at 250 °C and glycerol or EG solvation (Greene-Kelly test); and 4) alkylammonium saturation. In the course of low-temperature diagenesis but before the onset of illitization, mean layer charge of smectites continuously increases from approximately 0.56 to 0.73 per O20(OH)4 with increasing depth, and tetrahedral charge also increases continuously from approximately 0.21 to 0.38 per O20(OH)4 (beidellitization). The continuous increase in tetrahedral charge without change in peak intensity and shape suggests that the solid-state Al for Si substitution mechanism appears to predominate within beidellitization. After illitization, the content of the beidellitic layers continuously decreases, while the mean layer charge of expandable layers and the content of illite layers in I/S increase. This suggests that the conversion of a beidellitic layer to an illitic layer preferably occurs during early illitization. Thus, before illitization, beidellite-like layers are formed from precursor smectite, and during the early stage of illitization, the high charged beidellitic layers are probably consumed to form illite layers.