This article reassesses the so-called Nereid Monument (ca 380 BCE) at Xanthos in Lycia by focusing on the narrative and symbolic role of female figures within its sculptural programme. Constructed as the tomb for the Lycian dynast Erbbina, the monument has been noted for its over-human-size sculpture of Nereids, its historicising city-siege reliefs, as well as its spectacular fusion of visual and architectural styles, motifs and themes from various contexts throughout the Aegean and Anatolia. Building on this scholarship, I turn specifically to the monument’s innovative representations of non-mythological women in prominent areas of its visual programme: Erbbina’s dynastic consort and a distressed woman who is caught in the throes of military violence. By focusing on the role of female bodies in Erbbina’s funerary qua triumphal monument, I argue for the important narrative function of female bodies in articulating dynastic legitimacy and continuity. Finally, this article comments on the importance of femininity in addition to masculinity in dynastic expressions in the fourth century, thus anticipating major art-historical changes in the art of power at the beginning of the Hellenistic period.

Two-dimensional montmorillonite nanolayers (2D Mnt) are excellent adsorbents for methylene blue due to the fully exposed active sites, but the separation of 2D Mnt from water is difficult. The objective of the present study was to assemble 2D Mnt and graphene oxide sheets into a three-dimensional aerogel (3D Mnt-rGO Gel) to achieve easy solid–liquid separation. Structural characterization demonstrated that the Mnt-rGO Gel has a porous 3D structure with Mnt nanolayers distributed uniformly within; the introduction of 2D Mnt could reduce significantly the degree of restacking of graphene sheets. Adsorption tests indicated that 2D Mnt enhances the methylene blue (MB) removal performance of Mnt-rGO Gel with a large adsorption capacity of 207 mg g–1, which may be attributed to the adsorption of MB onto 2D Mnt and the increased adsorption surface of rGO resulting from the reduced restacking of graphene sheets. The MB was removed completely by 300 mg L–1 of Mnt-rGO Gel-3 in 180 min. The adsorption process of MB onto Mnt-rGO Gel followed the pseudo-second order kinetic model and the Langmuir isotherm model. Mnt-rGO Gel also showed good reusability. Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results suggested that the adsorption of MB onto Mnt-rGO Gel may be attributed to the π–π interactions between aromatic rings of MB and graphene, hydrogen bonding, and the electrostatic interactions between the nitrogen groups on the MB and oxygen-containing groups on the Mnt-rGO Gel.

The radiogenic isotope systematics of clay minerals are complex because of the intimate mixture of minerals from different origins such as detrital and authigenic sources. An important aspect of dating clays is the primary sample preparation and disintegration method. In the present study, a sample of weakly deformed Opalinus claystone from the Mont Terri underground site (Switzerland) was investigated after disintegration by three different methods. The Opalinus Clay was sedimented in the late Toarcian and early Aalenian and reached maximum temperatures of ~85°C during burial in the Cretaceous. The present study reports data from a comprehensive investigation comparing the effects of disintegration by: (1) disc milling; (2) repeated freezing and thawing; and (3) high-voltage discharges. K-Ar age values of the finest clay (<0.1 µm) released by the different disintegration methods are indistinguishable, indicating that the high-voltage liberation method does not influence grains as small as 100 nm. The K-Ar age values of particle-size separates decreased with decreasing particle size. The age values of the 2–6 µm separates correspond to the Carboniferous Period, which reflects the dominance of Paleozoic detritus in that size range. The age values of the smallest separates (<0.1 µm), on average 213 ± 4 Ma, exceed the numerical age of the formation (~177−172 Ma), which show predominance of detrital grains over authigenic grains even in the finest illite. In summary, isotope geochronology data suggest that the high-voltage method can be applied reliably for disintegrating claystones.

Illite from Muloorina, just south of Lake Eyre in South Australia, is commonly used as a standard ferric iron-bearing illite which has a cation exchange capacity (CEC) of ~22 meq/100 g, too high a value for this clay to conform to the most recent conclusions about illite composition. The objective of the present study was to reassess the Muloorina illite to determine the reason for this high CEC value. The composition determined by X-ray fluorescence analysis calculated to a cation charge of +22 is K0.68(Mg0.39Al1.02Fe0.543+Fe0.042+)[Si3.59Al0.38Fe0.033+]O10(OH)2. X-ray diffraction of glycolated and heated K-saturated Muloorina illite revealed no evidence of expandable layers. The cell dimensions are a = 5.314(1)Å, b = 9.040(1)Å, c = 10.135(3)Å, and b = 100.97(3)° (3σ in parentheses). Transmission electron microscopy revealed that Muloorina illite has a remarkably fine and uniform particle size in the form of irregularly stepped hexagonal crystals, averaging 60 nm in diameter at their widest, and 35 nm thick, each step being ~7 nm high. At most steps and between many steps defects occur where a 2:1 layer terminates, with a wide interlayer spacing beyond, commonly reaching to the crystal edge. Even though uninterrupted stacking of >10 or so 2:1 layers across one crystal is uncommon, the irregular distribution of the dislocations leaves appreciable structural continuity so that the mean diffracting thickness is of the order of 16 nm. Muloorina illite is not an interstratified illite-smectite, but a mica mineral with low-charge regions associated with terminating 2:1 layer defects. Such regions are wedge shaped at the nm scale and stabilized by the bonding of the illitic remainder of that interlayer. Approximately 17% of the total volume of each Muloorina illite crystallite is occupied by such low-charge 2:1 layers.

Interest in hydrotalcite-like compounds has grown due to their role in controlling the mobility of aqueous metals in the environment as well as their use as catalysts, catalyst precursors and specialty chemicals. Although these materials have been studied in a number of contexts, little is known of their thermodynamic properties. High-temperature oxide melt solution calorimetry was used to measure the standard enthalpy of formation for compounds M(II)1−xAlx(OH)2(CO3)x/2·mH2O (0.2 < x < 0.4, M(II) = Mg, Co, Ni and Zn). The enthalpy of formation of these compounds from the relevant single cation phases was also determined. The formation of HTLCs results in a 5–20 kJ/mol enthalpy stabilization from the single cation hydroxides and carbonates and water. The data are correlated to two variables: the ratio of divalent to trivalent cation in the solid (M(II)/Al) and the identity of the divalent cation. It was observed that the M(II)/Al ratio exerts a minor influence on the enthalpy of formation from single-cation phases, while greater differences in stabilization resulted from changes in the chemical nature of the divalent cation. However, the data do not support any statistically significant correlation between the composition of HTLCs and their heats of formation. Equilibrium geochemical calculations based upon the thermodynamic data illustrate the effect of HTLCs on the speciation of metals in natural waters. These calculations show that, in many cases, HTLCs form even in waters that are undersaturated with respect to the individual divalent metal hydroxides and carbonates. Phase diagrams and stability diagrams involving Ni-bearing HTLCs and the single-cation components are presented. The Ni(II) concentration as a function of pH as well as the stability diagram for the equilibrium among minerals in the CaO-NiO-Al2O3-SiO2-CO2-H2O system at 298 K are plotted.

Tuffs of the Tertiary Colbún Formation near Quinamávidain central southern Chile have been mapped and their mineralogy analyzed. The pyroclastic rocks present a maximum outcropping thickness of 120 m and are dominated by vitreous lapilli and minor lithic tuffs, the products of active volcanism nearby. About 10% of the tuffs consist of lenses of fine banded tuffs with a high leaf content that were deposited in shallow lakes during quiescent periods between periods of volcanic activity. This tuff sequence is pervasively transformed to clinoptilolite/heulandite and mordenite with variable amounts of plagioclase, minor quartz and smectite. Factors thought to have influenced this conversion to zeolites are a humid climate following deposition combined with a slightly elevated heat flow. Local hydrogeological conditions have modified the cation-hydrogen ion ratios across the study area favoring the formation of clinoptilolite/heulandite and mordenite with medium-minor smectite in the center and south, and a more abundant presence of smectite in the north of the study area.

Thank you, Dean Fairfax, for your warm introduction and thanks also to the American Society of International Law and the American University Washington College of Law for this invitation.

Alteration of basalt is a ubiquitous process on the vast oceanic crust surface and results in the formation of secondary-phase minerals that include clay minerals and Fe-(oxyhydr)oxides. Thus, this process is a significant consequence of water/rock interactions that could reveal the (bio)geochemical conditions of formation. Core samples at the basalt/sediment interface from a depth of 74.79 m below sea floor (mbsf) were recovered during the International Ocean Discovery Program (IODP) expedition 329 (2010.10.10–2010.12.13) in the South Pacific Gyre (SPG). Two distinct regions of yellow- and red-colored sediment were observed. The mineralogy, elemental composition, Fe oxidation state, and mineral structure of the altered basalt samples were analyzed using transmission electron microscopy (TEM) with selected area electron diffraction (SAED) patterns, energy dispersive spectroscopy (EDS), electron energy loss spectroscopy (EELS), and micro X-ray fluorescence (μ-XRF). In the yellow sediment, K-nontronite and feroxyhyte (δ’-FeO(OH)) were the dominant mineral phases, while Mg-rich smectite (saponite), chlorite, and hematite were found predominantly in the reddish sediment. The appearance of K-nontronite and feroxyhyte mineral assemblages in altered sediment indicated that oxidative conditions prevailed during basalt alteration. Variation in the Fe-oxidation states in the K-nontronite structure, however, may indicate that local reducing conditions persisted throughout the biogeochemical reactions.

A more controllable method to synthesize particular zeolites from geopolymers is needed in order to effectively use these materials in industrial applications. In the present study, a well-crystallized zeolite P1 was synthesized from a metakaolin-based geopolymer (SiO2/Al2O3=3.2) using a hydrothermal method. The products obtained by hydrothermal treatment were identified using X-ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface areas. The XRD patterns and SEM micrographs indicated that the structure and morphology of zeolite P1 could be controlled by the NaOH solution concentration, hydrothermal temperature, and the hydrothermal treatment time. The crystalline structure of the prepared zeolite P1 was refined using the Rietveld method and the crystal structure parameters were as follows: a = 10.01 Å, b = 10.01 Å and c = 10.03 Å. The optimal hydrothermal conditions to form zeolite P1 were 24 h at a hydrothermal temperature of 100°C and 2.0 M NaOH solution. Moreover, the synthesized zeolite P1 had a specific surface area of 36.56 m2/g.

Experimental studies have shown that a sharp, high-frequency IR band at ~3615 cm-1 (in H2O form) and at ~2685 cm-1 (in D2O form) is a common feature for all smectites, and its position correlates with layer charge. In order to explain the molecular origin of this band in terms of total layer charge, charge localization, as well as nature of interlayer cations influencing the position and intensity of this peak, a series of classical molecular dynamics (MD) simulations was performed for several smectite models. The smectite layers were described using a modified CLAYFF force field, where the intramolecular vibrations of H2O were described more accurately by the Toukan-Rahman potential. The power spectra of molecular vibrations of hydrogens were calculated for selected sub-sets of interlayer H2O to analyze quantitatively their contribution to the observed spectral features. The statistics of hydrogen bonds in the smectite interlayers were also analyzed to support the spectral calculations.

The simulation results demonstrated clearly that only the H2O molecules in close proximity to the smectite surface are responsible for the sharp vibrational band observed. Other hypotheses for the possible origins of this band were considered carefully and eventually rejected. Two orientations of H2O molecules donating one or two H bonds to the basal oxygens of the smectite surface (monodentate and bidentate orientations, respectively) were observed. In both orientations, these H bonds are quite weak, pointing to a generally hydrophobic character of the smectite surface. Both orientations contributed to the high-frequency band, but the monodentate orientation provided the predominant contribution because surface H2O molecules in this orientation were much more abundant. In good agreement with experiment, only a small difference in the peak position was observed between smectites with different charge localization. The effect of the total layer charge, i.e. the red-shift for higher-charge smectites, was also confirmed. This shift arose from the decrease in the H-bonding distances of H2O in monodentate and bidentate orientation.

The Li+ ion is used frequently as an environmentally acceptable surrogate for sorbing radionuclides in field tracer tests, and experiments using Li are an important part of assessing the potential transport of radionuclides in saturated alluvium south of Yucca Mountain, Nevada, the site of a proposed nuclear waste repository. Equilibrium partition constants (Li+ Kds) were measured using batch studies incorporating a wide range of Li+ concentrations and two different grain-size fractions of alluvium samples from multiple depth intervals in two wells. Cation exchange capacity, surface area, bulk mineralogy from quantitative X-ray powder diffraction, and trace Mn- and Fe-oxyhydroxide mineralogy from extractive studies were evaluated as predictors for linearized Li+ Kd values (K1in) in the alluvium. Many of the predictor variables are correlated with each other and this was considered in the analysis. Linearized Kd values were consistently higher for fine particle-size fractions than for coarse fractions. Single and multivariate linear regression analyses indicated that the clinoptilolite + smectite content, taken together as a combined variable, was the best predictor for Li+ sorption in the alluvium, although clinoptilolite content was clearly a better predictor when the two variables were considered separately in simple linear regressions. Even so, Li+ Klin predictions based on clinoptilolite and smectite abundance were accurate only to within about ±100%. This uncertainty suggests that there is either a high inherent variability in Li+ Klin values or that additional alluvium characteristics not measured or evaluated here may play an important role in simple Li+ cation exchange in the alluvium.

Focus here is placed on the pharmaceutical and biomedical applications of novel clay-drug hybrid materials categorized by methods of administration. Clay minerals have been used for many years as pharmaceutical and medicinal ingredients for therapeutic purposes. A number of studies have attempted to explore clay-drug hybrid materials for biomedical applications with desired functions, such as sustained release, increased solubility, enhanced adsorption, mucoadhesion, biocompatibility, targeting, etc. The present review attempts not only to summarize the state-of-the-art of clay-drug hybrid materials and their advantages, depending on the methods of administration, but also to deal with challenges and future perspectives of clay mineral-based hybrids for biomedical applications.

A microtexture analysis by TEM and AFM of palygorskite deposits from the Hawthorne Formation, southern Georgia is given. Palygorskite is the dominant mineral comprising an average of 65–70% of the sample volume with smaller volumes of smectite, illite and kaolinite. Morphologic observations indicate that the palygorskite formed in an unconfined environment, such as in the water column or in open-pore space. Some palygorskite textures appear to be secondary growths filling voids. An unusual texture is observed where smectite or illite-smectite (Reichweite, R = 0) form epitaxially on detrital illite and kaolinite particles. Oxides of Fe and Ti are common, and authigenic cassiterite is present but rare. Apatite is a common trace mineral in these sediments and occurs in a variety of textures. Apatite occurs as clusters which are believed to be small fecal pellets. These clusters have been partially dissolved and recrystallized and the crystals in the clusters are 50–100 µm in diameter. Other apatite crystals occur either as single crystals or in clusters that are not associated with fecal pellets.

The textural data of this study suggest that there was an evolving and complex mineralogical and geochemical system during and after deposition of the palygorskite deposits in the Hawthorne. The epitaxial overgrowths of smectite on detrital illite and kaolinite particles indicate an intermittent stratified water column occurring in the system. Freshwater was introduced into the system from the northeast of the Apalachicola embayment and overrode more saline water in the southwest portion of the embayment. The results of this study are consistent with previous environmental interpretations and provide additional details.

Reducing the environmental footprint of cement is an absolute necessity to meet the commitments of COP26 and to limit global warming to + 1.5°C compared to the pre-industrial level. In this context, particular interest has developed in recent years in the use of calcined clays as supplementary cementitious materials (SCMs). Due to their high reactivity, large reserves and homogeneous distribution on the earth's surface, calcined clays represent a viable alternative to conventional SCMs. Clay minerals are highly variable and numerous, each with their own characteristics. As a result, not all of them have potential for use as SCMs. The present paper investigated the use of palygorskite (a clay that has been relatively poorly studied) as an SCM. Two commercial palygorskites of different grades were selected and their calcination was studied by X-ray diffraction and pozzolanic activity tests. Blended cements incorporating 20% of each calcined palygorskite were prepared and the mechanical performance and resistivity of the mortars measured. The results show that the optimum calcination temperature is 800°C (allowing complete amorphization of the clay fraction and the highest pozzolanic reactivity) for both clays. Mortars made with 80% ordinary Portland cement (OPC) blended with 20% of 800°C calcined palygorskite allowed a significant increase in compressive strength and electrical resistivity compared to the reference (100% OPC). The clay sample with palygorskite as the dominant mineral exhibited the greatest pozzolanic reactivity and mechanical performance in cementitious systems, confirming that palygorskite is a clay mineral with a significant potential for a use as a SCM. The second sample with smaller palygorskite content also allowed a significant increase in mechanical performance. This demonstrated that it is not necessary to use high-purity samples and enhances the value of this type of material.

Phenol contaminants are highly biotoxic and have become a global problem threatening the environment and human health. The objective of the present study was to develop a very efficient and easily recyclable adsorbent to remove phenol. A magnetic montmorillonite composite with organic co-intercalation was fabricated by a simple one-step co-precipitation method and exhibited excellent phenol removal. Two surfactants, cetyltrimethylammonium bromide (CTAB) and erucic acid amide (EA), were successfully co-intercalated into the interlayer of Ca-montmorillonite, and Fe3O4 nanoparticles were simultaneously decorated to obtain Fe3O4-CTAB/EA-montmorillonite composite (Fe3O4-C/E-Mnt). The morphology and structure of Fe3O4-C/E-Mnt composite were explored by using different techniques such as X-ray diffraction, Fourier-Transform infrared spectroscopy, X-ray photoelectron microscopy and so on. The adsorption capacity of Fe3O4-C/E-Mnt for phenol was investigated under various conditions including temperature, pH, contact time, various phenol concentrations, and adsorbent dosage. The results showed that Fe3O4-C/E-Mnt retained a lamellar structure of Ca-Mnt with mesopores. Its interlayer space, surface area, and pore volume were increased. The Fe3O4-C/E-Mnt composite exhibited a good adsorption capacity (31.45 mg·g–1) for phenol with a removal efficiency of 85.46% at optimized conditions. Moreover, the adsorbent still maintained 78.32% of the adsorption capacity after five cycles. The adsorption test data of Fe3O4-C/E-Mnt followed the pseudo-second order kinetic model and the Langmuir model. The adsorption was a spontaneous, exothermic, entropy-decreasing process, and a possible adsorption mechanism of Fe3O4-C/E-Mnt was finally proposed.

Recent studies indicate that a template method for creating Al-pillared clays, in which surfactant micelles foster the creation of a homogeneous mesoporous network within the pillar, effectively enhance catalyst performance and adsorbent properties. No studies, however, have described the relative effects of the surfactant concentration and Al content on the textural and acidic properties and on the catalytic activity of the Al-pillared clays. The purpose of the present study was to fill this gap, using the isomerization of 1-butene as the test process for catalytic activity. Modified pillared clays (MPC) were prepared from a synthetic clay, TS-1, using different amounts of a non-ionic surfactant (Igepal CO-720) and a fixed concentration of a solution containing the Al polycation [Al13O4-(OH)24]7+. MPC with a fixed amount of surfactant and different amounts of Al were also prepared. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), temperature-programmed desorption of ammonia, 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR), and N2 adsorption/desorption isotherms. Isomerization of 1-butene at 250°C was used to test the catalytic activity. Analyses by XRD and XRF showed that the synthesized solids were amorphous and that the amount of pillaring by Al increased with the amount of Al complex used. Interestingly, the surface area and pore volume were directly proportional to the amount of surfactant employed and decreased with increasing amounts of Al pillaring. All solids showed activity for 1-butene isomerization, with a maximum conversion of ∼75%. Only cis- and trans-2-butene were observed. The absence of isobutene suggested that acid sites of moderate strength were formed, in agreement with the results obtained from the desorption of ammonia.