Multilateral development banks (MDBs) are international organizations subject to the law of international responsibility. Yet, the relationship between their accountability mechanisms and the International Law Commission (ILC) Articles on the Responsibility of International Organizations (ARIO) remains unclear. Understanding this relationship is essential in fully realizing the right to remedy in the development finance context. A comparative analysis of these legal frameworks clarifies that notwithstanding their different rationale, scope and functions, the two are not normatively conflicting and both serve to control public power. While the accountability mechanisms correct the ARIO's State-centric orientation by granting legal standing to project-affected people, they have their own deficiency concerning the actions they can prescribe to MDBs upon a finding of noncompliance. Highlighting that the MDBs’ mandate to ‘do no harm’ and pursue sustainable development is left unfulfilled by the accountability mechanisms’ deficient remedial function, this article identifies specific ARIO provisions to complement rather than undermine the MDBs’ accountability system. The ARIO's residual character, combined with the proposition that remedies arise not only from wrongful conduct but also from harm suffered by one party due to another's risky activities, justify this complementarity.

Loess is a collapsible soil; when it collapses, it can cause significant damage to structures built on it. Improvement in the stability and strength performance of loess is necessary to meet engineering needs. In the present study, the effects on the physical-chemical and rheological characteristics of Ghardaïa loess of adding bentonite and lime (southern Algeria) were examined. Rheological characterization of suspensions was implemented to assess the mechanical sensitivity of the bonds and the structural inter-particle resistance to both the chemical effect and mechanical impact. By analyzing the viscosity results and the evolution of the rheological parameters, the improvements needed in terms of the resistance characteristics of the loess-bentonite and loess-lime mixtures were evaluated and confirmed. The loess physical sensitivity was examined through grain-size distribution and plasticity properties. The pH and electrical conductivity of the mixtures were also used to explore structural modifications. Physical test results showed that introduction of the additives changed the loess texture and improved the plasticity of mixtures. Chemical examination (via change in pH and electrical conductivity) revealed the structural changes in the mixtures studied. Rheological test results showed that increasing concentrations of bentonite and lime improves the mechanical strength and increased the yield stress, consistency, and viscosity of the suspensions. The creation of cement interactions between mixture particles explained the increase in those parameters. Hydration, agglomeration, and inter-particle flocculation induced by the additives promoted these interactions. The experimental results led to the conclusion that bentonite and lime may represent an effective means to improve the performance in terms of preventing loess collapse and to increase its resistance to mechanical impact. The results presented in the present study may provide a geotechnical and rheological working database for the control and treatment of loess collapse and landslides in the region under study. Technical data related to loess may, therefore, be beneficial in terms of civil engineering, public works, hydraulics, and the manufacture of construction materials.

Ferrihydrite is a poorly crystalline Fe oxide of which 2-(XRD)line and 6-line varieties are commonly used in experiments, although species with intermediate numbers of peaks have been found in nature. To simulate nature, we synthesized two continuous series of ferrihydrites with between 2 and 6–7 peaks at room temperature in two different ways: (1) by varying the rate of hydrolysis of an Fe(NO3)3 solution (HR series); and (2) by oxidizing an FeCl2 solution containing up to 73 mmol Si/L (Si series), both at pH 7. Mössbauer spectra at 4.2 K showed that the ferrihydrites of the HR series had a constant magnetic hyperfine field (Bhf) at 4.2 K of 48.8 T whereas Bhf in the Si series dropped from 49.4 to 46.7 T as the Si content of the ferrihydrites increased from 0 to 74.7 g/kg of Si. Temperature scans between 4 and 170 K illustrate that the magnetic order breaks down at a temperature which is lower the higher the hydrolysis rate and the Si concentration in the ferrihydrite.

Weathering of chlorite adjacent to macro- and micro-passages (fissures) in regolith units has been studied to determine the alteration mechanisms and products and compare them to those that prevail at a distance from the open passages. The micro-fissures in the saprolith units evolve as a function of weathering with an increase in micro-fissure density and their infilling with ferriargillans corresponding to an increase in weathering intensity. In the saprock and saprolite units, goethite-rich bands with surrounding reddish haloes invade the chlorite adjoining the micro-fissures. In the reddish haloes surrounding the goethite bands and fissures, the phyllosilicates alter to an intimate mixture of goethite, kaolinite, feroxyhyte and halloysite with the possible nanoscale presence of other fine-grained iron aluminosilicates such as hisingerite and smectite. In the fine saprolite, the weathering products after original chlorite adjoining the micro-fissures bearing ferriargillans, alter directly to ferriargillan products — kaolinite and goethite. The lack of orientation of the products with the parent phyllosilicates indicates the operation of a dissolution-precipitat ion mechanism which is in contrast to the topotactic alteration mechanism functioning at a distance within the phyllosilicate grain assemblage. The differences in alteration mechanisms and products of chlorite weathering in different microsites suggest the rate of weathering of chlorite can differ in microsites within individual regolith units. The presence of fine-grained metastable products in the form of feroxyhyte and halloysite adjoining the fissures suggests an Ostwald Step Rule sequence during alteration of phyllosilicates with rapid oxidation of Fe and the presence of Si in the microsite considered the main factor favoring fine-grained metastable products.

The crystal structure of biotite-1 M from Bancroft, Ontario, with the formula: $\left({\text{K}}_{1.96}{\text{Na}}_{0.13}{\text{Ca}}_{0.01}\right)\left({\text{Mg}}_{3.15}{\text{Fe}}_{2.59}^{2+}{\text{Ti}}_{0.17}{\text{Mn}}_{0.09}\right)\left({\text{Si}}_{5.98}{\text{Al}}_{1.92}{\text{Ti}}_{0.10}\right){\text{O}}_{20}\left[{\left(\text{OH}\right)}_{1.47}{\text{F}}_{1.98}\right]$, was determined by Rietveld refinement using high-resolution neutron powder diffraction at in situ temperatures ranging from 20 to 900°C. The room-temperature structure of the samples heated to between 400 and 900°C using an electric furnace in air was also refined. The crystal structures were refined to an RP of 2.98 — 5.06% and Rwp of 3.84–6.77%. For the in situ heating experiments in a vacuum, the unit-cell dimensions increased linearly to 600°C. The linear expansion coefficient for the c axis was 1.65 × 10−5°C−1, while those for the a and b dimensions were 4.44 × 10−6°C−1 and 5.21 × 10−6°C−1, respectively. Accordingly, the increase in the unit-cell volume up to 600 C occurred mainly along the c axis, resulting from the expansion in the K coordination sphere along that direction. Results for all K−O bonds were analyzed in terms of the lattice component and an inner component of the structural strain. The ditrigonal distortion decreased (3.76 at 20°C to 1.95 at 600°C) with temperature, because the shorter bonds expanded and the longer bonds contracted. The increase in the interlayer separation and the decrease in the interlayer octahedral flattening angle confirmed that the c-dominated expansion occurred in the interlayer region. In the case of the ex situ-heated samples, the cell dimensions decreased sharply at temperatures over 400 C. The octahedral sheet thickness and mean <M−O> distance decreased linearly due to oxidation of octahedral Fe. However, the interlayer separation and mean <K−O> distance decreased at temperatures over 400°C. At 400°C, dehydroxylation began to increase and interlayer regions became more constricted. The overall cell parameters decreased rapidly with increasing temperatures due to dehydroxylation. The large inner strain components in the K−O bonds also resulted in an increase in the considerable ditrigonal distortion (3.57° at 400°C to 6.15° at 900°C).

The dissolution kinetics of sepiolite in hydrochloric acid and nitric acid were studied in a batch reactor. The effects of reaction temperature, acid concentration, particle size and solid-to-liquid ratio on the dissolution process were investigated. Experimental studies were carried out in the ranges of 25–75°C for reaction temperature, 0.25–1.00 mol/L for acid concentration, 0.00755–0.05020 cm for average particle size and 2.5 to 12.5 g of solid/100 mL of acid for solid-to-liquid ratio. It was determined that the dissolution process is controlled by resistance of the diffusion through the product layer. The activation energies of the process were determined to be 40.8 and 38.3 kJ/mol for hydrochloric and nitric acid, respectively. The apparent rate constants were expressed as a function of reaction temperature, acid concentration, particle radius and solid-to-liquid ratio: kαe−4910(1/T)Cr−0.6 (s/l)−1 and kαe−4606(1/T)Cr−0.5 (s/1)−1 for hydrochloric and nitric acid, respectively; k is the apparent rate constant in min−1; T, the reaction temperature (K); C, the acid concentration (mol/L); r, the initial particle radius (cm); s/l, the solid-to-liquid ratio (g of solid/100 mL of acid).

Bentonite, biotite, illite, kaolin, vermiculite and zeolite were treated with 0.1, 1.0 and 5.0 mol. dm−3 HCl or NaOH. Suspensions of Na homoionic forms of the initial and the treated minerals were back titrated with 0.1 mol. dm−3 NaOH. From back-titration data variable surface charge, QV, vs. pH dependencies and apparent surface dissociation constant distribution functions were estimated. Variable charge vs. pH curves were scaled against cation exchange capacity at pH 7.2 to obtain actual charge, QA, vs. pH plots. In general both treatments led to an increase of QV, while the QA value increased and decreased depending on the mineral and the treatment. Products of 5 mol dm−3 NaOH action on zeolite and of 1 and 5 mol. dm−3 NaOH on kaolin apparently developed a positive surface charge below pH ∼3.7 and below ∼4.3, respectively.

The heterogeneity of charge-generating surface groups was observed in natural minerals. During acid treatment, the number of weakly-acidic surface functional groups increased while the number of groups of stronger acidic character decreased. The opposite was found for alkaline treatment: the number of surface groups of intermediate acidity increased and that of low acidity decreased.

The main objective of the present work was to functionalize nanoclays with organosilanes and surfactant in order to facilitate the dispersion of the nanofillers in the host fluoroelastomer (FKM) polymer matrix. Better dispersion was achieved by improving interaction between the clay polymer nanocomposite (CPN) constituents. The first part of this study investigated modification of montmorillonite (Mnt) using different saturated and unsaturated alkyl silanes and an alkyl hydrocarbon ammonium quaternary surfactant. Silicon magic angle spinning nuclear magnetic resonance spectroscopy, thermal gravimetric analysis (TGA), elemental analysis, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy were used to characterize the silane-grafted clays. Results indicated that the amount of silane grafted depended on the specific structure of the silane. Silane-grafted Mnt was also modified with ionic surfactants intercalated between the clay layers. A 169% increase in the clay basal spacing (from initial spacing of 10.0 Å to 26.9 Å) was achieved. The second part of the study successfully synthesized FKM nanocomposites containing custom-functionalized Mnt, with the aim of producing reinforced high-performance materials. The effects of clay modification on the morphology and thermal properties of the CPN were studied using XRD, TGA, scanning electron microscopy, and transmission electron microscopy. The CPN made with the modified clay exhibited greater thermal stability than the CPN of the commercially available modified Mnt, with a degradation onset point ~ 40°C higher.

Reaction of a Mg-Al carbonate layered double hydroxide (LDH) with boric acid leads to a borate-pillared LDH with the stoichiometry [Mg0.65Al0.35(OH)2][B3O5]0.35.0.65H2O and an interlayer spacing of 1.07 nm. Infrared and 11B magic angle spinning nuclear magnetic resonance data are consistent with the presence of polymeric triborate anions of the type [B3O4(OH)2]nn- in the interlayer galleries so that the material can be formulated as [Mg0.65Al0.35(OH)2][B3O4(OH)2]0.35.0.30H2O. The flame-retardant properties of the borate-pillared material and the carbonate precursor in composites with ethylene vinyl acetate copolymer were compared. Introduction of the borate anion leads to a significant enhancement in smoke suppression during combustion without compromising the flammability of the material. This is related to the synergistic effect between the host layers of the LDH and the borate anions uniformly distributed in the interlayer region.

Semiconductor photocatalysis has been regarded as one of the most promising methods for treatment of Cr(VI)-containing wastewater, but the high recombination rate of photogenerated carriers and photocorrosion have limited severely its practical application. The objective of the current study was to employ a layered double hydroxide (LDH) to mitigate these problems by designing and constructing a multiple heterojunction system of g-C3N4/LDH/Ag3PO4 (CNLDHAP) through a two-step hydrothermal route. The structures, morphologies, chemical states, and optical properties of the products were investigated systematically. The CNLDHAP composite showed superior photocatalytic activity for Cr(VI) reduction than that of the individual components under visible-light irradiation. The composite exhibited high photocatalytic reduction stability after five recycles. The enhanced photocatalytic performance may originate from the very efficient separation of photogenerated carriers of the multiple heterojunction system. Possible photocatalytic mechanisms for the reduction of Cr(VI) over the CNLDHAP composite photocatalyst are proposed.

Kaolinite is often used as a base for the synthesis of new organo-mineral nanomaterials designed for applications in industry and in environmental protection. To make the mineral structure more likely to interact with organic molecules, a kaolinite-methanol complex (KM) can be used. In the present study, different experimental procedures were tested to investigate the formation of the KM. The kaolinitedimethyl sulfoxide intercalation compound (KDS), either wet or dried, was used as a pre-intercalate. The samples obtained were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, CHNS elemental analysis, 13C CP-magic angle spinning nuclear magnetic resonance (MAS NMR), and 27Al and 29Si MAS NMR techniques. The method of density functional theory with dispersion corrections (DFT-D2) was used to explain the structure and to simulate the vibrational spectra of KM. Theoretical results were compared with experimental data. The most effective formation of the KM (d001 = 11.1 Å — wet; d001 = 8.7 Å — dried) was observed when the dried KDS precursor was used. In such conditions the degree of intercalation reached ~98% after 24 h of reaction time. As indicated by the CHNS elemental analysis, ~1/6 of the inner-surface OH groups were grafted by OCH3 groups. The esterification reaction was less efficient at higher temperatures or when wet KDS was used. In the latter case, the excess of very polar dimethyl sulfoxide molecules prevented intercalation of methanol and further grafting. Detailed analysis of the results of theoretical simulations revealed that the reaction of the KDS with methanol led to the formation of kaolinite with both grafted methoxy groups and intercalated methanol, and water molecules in the interlayer space. The spectra calculated revealed the contribution of individual vibrational modes into the complex bands, i.e. the energy of C-H vibrations was in the order: νasCHmet > νasCHmtx > νsCHmet > νsCHmtx.

Differentiating clay minerals that formed in a supergene environment during deep chemical weathering from those that formed during hydrothermal alteration at higher temperatures associated with a mineralizing event is important in the exploration for epithermal Au deposits. The purpose of this study was to further elucidate this topic by comparing morphological and chemical properties of clay minerals in saprolite overlying epithermally altered bedrock at the Vera Au deposit, Queensland, Australia, with those of clay minerals in saprolite overlying bedrock adjacent to the epithermal alteration zone. X-ray diffraction (XRD) and analytical transmission electron microscopy (ATEM) investigations identified kaolinite, illite, and interstratified illite-smectite, together with quartz, Fe and Ti oxide minerals, and the sulfate minerals jarosite, gypsum, alunite, and natroalunite. Kaolinite crystals within the weathered argillic alteration zone proximal to the epithermal quartz vein are generally larger (up to 3 μm in diameter) and better formed (subhedral to euhedral) than crystals in saprolite distal to the hydrothermal alteration zone, in which smaller (mostly <1 μm), subhedral to anhedral crystals dominate. Energy-dispersive spectrometry (EDS) analysis of single crystals indicated that kaolinite within the alteration zone has an Al/Si ratio indistinguishable from reference kaolinite and has small Fe concentrations, whereas distal saprolitic kaolinite has smaller Al/Si and greater Fe/Si ratios, consistent with the formation of low-Fe kaolinite during hydrothermal alteration and higher-Fe kaolinite during weathering. Illite and interstratified illitesmectite (I-S) were distinguished from kaolinite by their morphology and greater K/Si and smaller Al/Si ratios. The Illite and I-S morphology ranged from thin irregular masses through lath-like crystals in hydrothermal samples to larger, irregularly shaped crystals. The Ca/Si and K/Si ratios of single crystals in Ca-saturated clay minerals were consistent with the I-S interstratification parameters determined from XRD patterns.

The conventional methods of direct bromination of organic compounds with elemental bromine have several major drawbacks such as handling difficulty, corrosive effect, and toxicity, in addition to over-bromination and problems with isolation of products from the reaction mixture. Supported catalysts and reagents have become popular in the synthesis of organic chemicals over recent decades because they have overcome almost all of the drawbacks noted above. In the present study, a new clay polymer nanocomposite (CPN)-supported brominating agent was prepared from montmorillonite (Mnt) and styrene-co-vinyl pyridinium polymer. The reagent was obtained by the direct interaction of a two-fold excess of poly(styrene-co-N-methyl-4-vinylpyridinium) bromide with Na-montmorillonite (NaMnt) through ion exchange between Na+ of the NaMnt and pyridinium ions in the copolymer to provide CPN3 with free methylpyridinium bromide side chains. The structure of the CPN3 prepared was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Treatment of the CPN3 with bromine using the bromide ions which remained led to the perbromide-supported reagent, CPN4. The activity of the resulting CPN4 brominating reagent was examined through direct bromination of some alkenes, arenes, and carbonyl compounds and compared with the effectiveness of a crosslinked polymeric perbromide reagent. The yields obtained from application of the reagent were moderate to excellent. The advantages of this reagent, such as stability at room temperature, ease of regeneration from the polymeric by-product, and the yields of the brominated products, confirm the viability of using a CPN-supported brominating agent as a reactive reagent in organic chemistry synthesis.

The Upper Miocene Mustafapas-a member of the Ürgüp Formation in the Cappadocia region consists predominantly of mudstones, sandstone, and conglomerate lenses with ignimbrite and basalt intercalations. The mudstones are an important source of raw materials for the ceramics industry in Turkey. A detailed mineralogical, geochemical, and genesis study of these materials has not been performed previously and the present study aims to fill that gap. The characteristics of mudstones of the Mustafapas-a member were examined using X-ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, and chemical analyses. Weathering products of ophiolitic and pyroclastic rocks were transported into the tectonically subsided zone where they accumulated as fluvial and lacustrine deposits.Weathering in the mudstones is evidenced by smectite flakes associated with relict pyroxene, rod-like amphibole, feldspar, and volcanic glass. The chemical composition of mudstones and their distribution suggest that the depositional basin was supplied with ophiolitic material in the south and ignimbrite material in the north. This interpretation is based on an increase in the quantity of feldspar and opal-A and a decrease in the Fe2O3+MgO/Al2O3+SiO2 ratio from south to north in the study area. The northward increases in Light Rare Earth Elements/Heavy Rare Earth Elements, La/Yb, Zr/Ni and Zr/Co ratios and Nb, Ba, Rb, Sr, and Eu in the mudstones of the Mustafapas-a member with positive Eu anomalies suggest that the Fe, Mg, Al, and Si required to form smectite were supplied mainly through the decomposition of amphiboles, pyroxenes, feldspars, and volcanic glass during weathering processes. After the deposition of mudstones, relative increases in evaporation-controlled Ca, K, and Al in pore water favored the partial dissolution of Ca-bearing minerals and smectite flakes and in situ precipitation of calcite and traces of illite fibers under alkaline micro-environmental conditions during early diagenesis.

The influence of cation size on the misfit between the tetrahedral and the octahedral sheets of serpentine layers, and thus on the curvature of serpentine minerals, has been studied using an experimental approach, based on scanning and high-resolution transmission electron microscopies (SEM and HRTEM, respectively) coupled with analytical electron microscopy (AEM), and a theoretical approach, based on the elastic theory of thin plates and the surface stress concept.

Various Ni3(Si,Ge)2O5(OH)4 serpentine syntheses were prepared, with progressive tetrahedral substitution for Si by the larger Ge ion, the ratio Ge/(Si + Ge) ranging from 0 to 100%. Other parameters (temperature, time duration, water pressure) were fixed. From SEM-HRTEM observations and AEM analyses of all samples, two types of serpentine minerals were characterized: (1) curved structures of tubular or ‘roman-tile’ shape (curvature radius of 10 nm for 0% Ge, increasing with the Ge content), when the Ge tetrahedral content is <25%; (2) perfectly plane structures, with hexagonal or triangular shape (view normal to the layers), for greater Ge contents. These results prove the direct influence of cation size on the crystal curvature.

From a theoretical point of view, a single serpentine layer with a misfit between its tetrahedral and octahedral sheets can be considered as an elastic thin plate subjected to two different surface stresses, σ+ and σ−, on its two faces. The difference σ+ − σ− between these two surface stresses was calculated from the above geometrical misfit, and the curvature of the serpentine layer was related to σ+ − σ−, according to the elastic theory of thin plates. The calculated curvature radii, and the Ge content of transition from curved to plane structures, are in agreement with the above observed values. Curved serpentine crystals may then be considered as a stacking of such elastically curved single serpentine layers.