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Research into the mechanical properties of materials has been a focus of study for over a century leading to sophisticated advances in our understanding of not only materials of everyday use, but also minerals within the Earth and of other planetary bodies. The conditions within the Earth range over several thousands of Kelvins (K) in temperature and several million times atmospheric pressure (stated in gigapascals (GPa)). Adding to these extreme conditions, minerals under these conditions are also undergoing continuous microstructural evolution through processes such as phase transformation, plastic deformation, and dynamic recrystallization for which no satisfactory constrains have been achieved. Several experiments have focused on determining the various properties of minerals under lower mantle conditions using diamond anvil cells combined with synchrotron radiation. While enlightening, these have been relegated to either bulk statistical approaches or individual crystal studies, both limited in the achievable spatial resolution which is a crucial aspect when trying to scale from the microstructural level to large scale physical behavior. From a computational perspective, the processes in the Earth have also been a key area of interest with several modeling attempts attempting to constrain the active deformation mechanisms in minerals that would give rise to current observations of seismic anisotropy. Many models have proven insightful, but again focused on select regions and again lacked the spatial resolution to resolve the long-wavelength anisotropic structures of the lower mantle. This thesis aims to provide a route, both experimentally and computationally, to expand the current understanding of the behavior of lower mantle minerals on scales spanning from individual grain behavior to that of a polyphase aggregate. Quantitative information of the stress environment, phase distribution, as well as crystallographic orientations and microstructural relations are obtained across a range of mantle conditions using in-situ high energy synchrotron radiation combined with far field high energy diffraction microscopy, a.k.a. multigrain crystallography (MGC). Plasticity modeling is also performed under conditions of the lower most mantle to ascertain the active deformation mechanisms at play that could give rise to the long wavelength anisotropic structure observed near the core mantle boundary (CMB).In Chapter 2, MGC is applied to a sample of San Carlos olivine beginning at ambient conditions and through the olivine  γ-ringwoodite phase transition. At high pressure and ambient temperatures, by measuring the evolution of individual Bragg reflection morphology, olivine shows profuse angular intensity broadening consistent with the onset of yielding at a measured stress of ~1.5 GPa, considerably lower than previously reported under similar conditions, which may have implications for constitutive models of lithospheric strength and dynamics. Furthermore, γ - ringwoodite phase was found to nucleate as μm (micrometer) to sub- μm grains imbedded with small amounts of a secondary phase at 15 GPa and 1000 °C. Using MGC, information of individual crystallites from a secondary unknown phase were extracted and refined where it was found to have a structure consistent with the phase recently named Poirierite formed from shock metamorphism and has been described in chondritic meteorites (Tomioka et al. 2021) but yet to be seen during high P-T experiments.Chapter 3 continues deeper into the Earth’s mantle applying MGC to investigate the microstructural evolution during the formation of bridgmanite ((Mg,Fe)SiO3) and ferropericlase ((Mg,Fe)O) from olivine. A weaker ferropericlase forms with random orientations as a fine-grained (< μm - 2 μm ) interconnected matrix around a larger (2-9μm) and higher stressed bridgmanite phase; a configuration that has been implicated in slab stagnation as well as plume deflection in the upper part of the lower mantle through influences on the local viscocity structure surrounding subducting slabs. Pairs of individual twins in the bridgmanite phase are extracted with μm-scale spatial resolution confirming a previously reported {110} twinning relation previously only seen in ex-situ experiments which appears to act as a more energetically favorable mechanism of stress relaxation during grain growth compared to plastic deformation. When combined with the random orientations of ferropericlase, this twining mechanism in bridgmanite would act to reduce any seismic anisotropy from the aggregate.Chapter 4 implements plasticity modeling to investigate the possible link between plastic deformation and phase transitions with the presence of seismic anisotropy at the base of the Earth’s lower mantle. To date there has yet to be consensus on the specific mechanisms that could give rise to the observed shear-wave anisotropic signatures at depths of 2500-2800 km. Strong anisotropy in magnesium post-perovskite (pPv) has been invoked, but different studies disagree on the dominant slip systems at play. In the model presented in this thesis, the most recent results from atomistic calculation and high-pressure deformation experiments are coupled with a realistic pyrolytic composition composed of 74% bridgmanite 17% and 9% calcium perovskite and a 3-dimensional geodynamic model, to compare the resulting deformation-induced anisotropy with seismic observations of the lowermost mantle. Additional complexities are included accounting for the P-T dependent forward and reverse phase transitions from bridgmanite to pPv. When including this feature, a strong textural inheritance is found between bridgmanite and pPv with (001) dominant slip, not seen when bridgmanite converts to pPv with (010) dominant slip. It is also seen that either dominant (001) or (010) slip can both explain the seismically observed anisotropy in colder regions where downwellings turn to horizontal flow, but only a model with dominant (001) slip matches seismic observations at the root of hotter large-scale upwellings.

The behavior of oil and water in tight rocks can change the distribution of oil or water in pores, so that affect the production of crude oil. Nuclear Magnetic Resonance (NMR) method is an effective and non-destructive tool for evaluating rocks with comparison and analysis both quantitatively and qualitatively. In our study, 20 MHz NMR Relaxometry is used as a key technique to study the changes of water and oil behaviors in Chinese lacustrine Qingshankou shales under different saturated states (imbibition and evaporation without pressure). The results show that variation in different proton populations (water, oil and organic) can be distinguished using 2D T1–T2 maps. The comparison among T1-T2 maps with different saturated states shows that different signal regions changed during oil and water migrations, which the 1D NMR Relaxometry may be not easy to approach. Combined with the pyrolysis analysis, T2 shift and differences of signal regions in T1-T2 maps can reflect properties such as wettability and composition (organic matter, clay and magnetic minerals) to some extent. This study provides better insight into oil and water behaviors in Lacustrine Oil Shales with further understanding of 20 MHz NMR 2D T1-T2 maps both in qualitative and quantitative analysis.

Shale mechanical properties are important for shale gas production, but the magnitudes are difficult to estimate, standard size cores are hard to sample, and secondary interstice generation is inevitable. This paper proposes a method for determining shale macroscale modulus, which is determined at a hierarchy of scales from the nano-to macro-scales. Microscale measurements are upscaled to estimate the corresponding magnitudes at the macroscale. A case study is conducted with Silurian shale samples, using the hierarchy scales, gridding nanoindentation, atomic force microscopy (AFM), mineral liberation analysis (MLA), X-ray diffraction (XRD), and uniaxial compression tests. The mineral compositions are analyzed using MLA and XRD, and the shale composition is described in terms of clay minerals, organic matter, and siliceous and carbonate contents. The variation in the Young's modulus is analyzed based on the recorded indentation depth curves and modulus distributions. The nanoindentation and AFM results are upscaled to the centimeter scale through the Mori–Tanaka method. The upscaled results exhibit satisfactory fitting with the conventional uniaxial compression results, although the fitting of the upscaled AFM results is better than nanoindentation. The proposed approach can be applied to promptly and comprehensively predict the shale mechanical parameters during shale gas exploration.

Due to seasonal climate alterations, the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles. The X-ray micro computed tomography (micro-CT) acted as a non-destructive tool for characterizing the microstructure of soil samples exposed to a range of damage levels induced by dry-wet cycles. Subsequently, the variations of pore distribution and permeability due to dry-wet cycling effects were revealed based on three-dimensional (3D) pore distribution analysis and seepage simulations. According to the results, granite residual soils could be separated into four different components, namely, pores, clay, quartz, and hematite, from micro-CT images. The reconstructed 3D pore models dynamically demonstrated the expanding and connecting patterns of pore structures during dry-wet cycles. The values of porosity and connectivity are positively correlated with the number of dry-wet cycles, which were expressed by exponential and linear functions, respectively. The pore volume probability distribution curves of granite residual soil coincide with the χ2 distribution curve, which verifies the effectiveness of the assumption of χ2 distribution probability. The pore volume distribution curves suggest that the pores in soils were divided into four types based on their volumes, i.e. micropores, mesopores, macropores, and cracks. From a quantitative and visual perspective, considerable small pores are gradually transformed into cracks with a large volume and a high connectivity. Under the action of dry-wet cycles, the number of seepage flow streamlines which contribute to water permeation in seepage simulation increases distinctly, as well as the permeability and hydraulic conductivity. The calculated hydraulic conductivity is comparable with measured ones with an acceptable error margin in general, verifying the accuracy of seepage simulations based on micro-CT results.

Quartz is abundant in the Earth’s continental crust and persistent throughout the geological record. Trace element signatures in silica minerals can be used to infer processes operating in magmatic and hydrothermal systems. Conventional analyses of trace elements in silica minerals are limited by either spatial or mass resolution [e.g., wavelength-dispersive X-ray spectroscopy, micro-X-ray fluorescence, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS)]. Time-of-flight SIMS (TOF-SIMS) is a relatively new technique for geological applications and provides both high spatial and mass resolution. This minimally destructive, in situ technique rapidly acquires a full suite of elements down to tens of nanometers depth. No previous study has utilized TOF-SIMS to analyze quartz or silica. Four samples of silica minerals representing distinct environments in a magmatic-hydrothermal system were characterized with optical microscopy and qualitative cathodoluminescence (CL), quantitatively analyzed for trace elements with a 157 nm LA-ICP-MS, and qualitatively mapped for trace elements using TOF-SIMS. The novel technique produced maps of trace element distribution in silica minerals to a maximum resolution of 65 nm and consistently resolved light elements (including Li) to 195 nm. That makes this study the highest resolution geochemical characterization of silica minerals and places it among the highest resolution analyses by TOF-SIMS, or any technique, for that matter. TOF-SIMS isotope maps differentiate trace elements hosted in nano- and micro-inclusions from lattice incorporation in quartz and cryptocrystalline silica—an impossibility for lower resolution techniques, allowing insights into cations substituting for Si4+ in the crystal lattice and their role in activating CL in low-temperature epithermal quartz. Further development of this technique could see TOF-SIMS become a routine tool for measuring diffusion profiles in a range of other geological materials. Quantification of TOF-SIMS would revolutionize mineral characterization, especially given its temporal efficiency and low-sampling volume.

The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uranium leaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, was taken as the research object. The fractal characteristics of the pore structure of the uranium-bearing sandstone were studied using mercury intrusion experiments and fractal theory, and the fractal dimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics was studied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that the rate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant (K) is linearly related to the pore specific surface fractal dimension (DS) and the pore volume fractal dimension (DV). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics were established using the unreacted shrinking core model, and the linear relationship between the fractal dimension of the sample's pore structure and the dissolution rate during the leaching was fitted.

This study focuses on the prediction of the porosity of nonuniform sediment mixtures, considering the effects of particle packing. A random particle packing model has been developed for the porosity of bimodal mixtures by extending the existing random particle filling theory. Coefficients in the developed model are calibrated by fitting the model to measured data for a variety of bimodal mixtures, including spherical glass particles, rounded quarry grains, and natural sediments. The model coefficients are found to be functions of the diameter ratio of coarse and fine particles, separately for spherical glass particles and natural sediments due to differences in particle shapes. The bimodal mixture model is then extended to trimodal particle mixtures in three approaches: two based on serial packing and one based on random packing. These models are tested against experimental data of six trimodal mixtures with spherical glass beads. The results show that the random packing model and the fine–medium–coarse particle serial packing model predict well the observed trimodal mixture porosities.

The evolution of the U-Pb decay system is determined by their initial isotopic composition in the proto-Earth and the subsequent global differentiation. The differentiation is highly complicated because of large-scale evaporation and multi-stage core formation in Earth accretion. We statistically rebuild the accretional history of Earth using a series of N-body simulations. This provides us with an estimation of the amount of silicate melting and thus temperature and pressure at the bottom of the magma oceans driven by continuous planetesimal impacts. We further assumed different evolutionary paths of the redox state and found a reduced process from an oxidized state consistent with the current value of Pb content and μ value (238U/204Pb) in the bulk silicate Earth. Meanwhile, the fraction of the impactor's core that participates in the re-equilibration is around 0.2–0.7. Our model predicts the final μ value equals the observed value, 8.25, regardless of the minor contribution of the late veneer (0.2). The evolution of μ determines the growth rate of radiogenic Pb isotopes. The episodic increase of μ in multi-stage core formation accelerates the growth of radiogenic Pb isotopes (206Pb and 207Pb) and finally causes a slight deviation of the composition of Pb isotopes (206Pb/204Pb and 207Pb/204Pb) to the right of 4.567-Ga Earth Geochron. A multi-stage evolution model for U–Pb system can explain the modern terrestrial μ value, but has little influence on the puzzle of “the first Pb paradox”.

Potential use of raw clayey deposits from El Jadida, Morocco, in the manufacture of traditional ceramic products has been evaluated through a careful sampling and an in-depth characterization of the outcropping features around Ouled Sidi Ali Ben Youssef area (El Jadida city). We collected six representative clay-rich materials (C1–C6) for subsequent analyses by several spectroscopic and mineralogical techniques including physico-chemical, mineralogical, and thermal analyses. Our results revealed high amounts of oxides, mainly SiO2, Al2O3, Fe2O3, CaO and MgO. Those ferruginous clays were found suitable for dark ceramic bodies. Further mineralogical examination confirmed low to medium contents of clay minerals, but subordinated by quartz, calcite, dolomite and plagioclase as the main nonclay minerals. Ternary diagram plots indicated that the studied clays were suitable for structural clay products and clay roofing tiles. C5 sample exhibited the best physico-chemical and mineralogical properties due to its illitic nature (64%), low quartz content (28%), high plasticity index (32) and lower loss on ignition (10.84%). Therefore, C5 clayey sample was selected as a potential candidate to be mixed with expanded perlite (EP) for the production of insulating ceramics. Specimen were prepared from the new mixture (i.e., C5 and EP) by pressing and firing at 1100 °C. The obtained ceramic bodies were ascertained by addressing their bulk density, water absorption, shrinkage, bending strength, thermal conductivity, structural and mineralogical properties.

In order to study the propagation laws of acoustic wave of coal samples from the Upper Permian Xuanwei Formation in the east of Yunnan Province, China, under saturated water and dry conditions, the basic physical parameters, acoustic parameters and anisotropic parameters were obtained through the experiments. Based on FFT and wavelet analysis theory, the spectral characteristics of coal samples under different conditions were studied. The results show that physical parameters of coal samples in different directions have different values, that is, the anisotropy of coal samples is obvious. When the coal samples are saturated with water, the acoustic velocities and the attenuation coefficient increase, whereas the dominant frequency decreases. The signal amplitude of the frequency domain significantly decreases, that is, the internal structure of coal samples is damaged. The P-wave velocity and S-wave velocity increase with the increase of the confining pressure, whereas the anisotropy parameters decrease with the increase of the confining pressure. Overall, this study provides the basis to understand basic acoustic information and anisotropy characteristics of coal samples.

International audience; In order to understand the nature of the dust that accreted onto chondrules in the nebula and to unravel the conditions of formation of fine grained rims (FGRs), we studied three of the least altered chondrites from different chondrite groups (LL3.00 Semarkona, CO3.0 DOM 08006, CR2.8 QUE 99177) and compared the results with our previous work on the Paris CM chondrite (Zanetta et al., 2021). For each sample, we selected representative rimmed chondrules showing minimal traces of aqueous alteration. We performed high-resolution SEM X-ray chemical mapping to obtain relevant phase abundances and grain size distributions. Four FIB sections were then extracted from each meteorite, two in the rims and two in their adjacent matrix for quantitative TEM analysis. At the microscale, texture, modal abundances and grain size differ depending on the chondrite but also between FGRs and their adjacent matrix. At the nanoscale (i.e. TEM observations), matrices of the four chondrites consist mostly of domains of amorphous silicate associated with Fe-sulfides, Fe-Ni metal, Mg-rich anhydrous silicates and an abundant porosity. The related FGRs in Semarkona (LL) and DOM 08006 (CO) exhibit more compact textures with a lower porosity while FGRs in QUE99177 (CR) are similar to the matrix in terms of porosity. In the three chondrites, FGRs are made of smooth and chemically homogeneous amorphous (or nanocrystalline) silicate with no porosity that encloses domains of porous amorphous silicate bearing Mg-rich anhydrous silicates, Fe-sulfides, Fe-oxides and sometimes metal and Fe-rich olivines. The average compositions in major elements of the amorphous regions are similar for the FGRs and the matrix within a given chondrite (but differ between chondrites). The texture and the chemical homogeneity of the smooth silicate and the fact that it encloses domains of porous amorphous silicate bearing other mineral phases similar to matrix-like material suggests a formation by condensation. Areas that are enclosed in this smooth silicate exhibit Fe-rich olivine formed through Fe interdiffusion that also suggest a thermal modification of the dust accreted to form FGRs. These characteristics indicate a transformation process for the modification of the FGR material similar to the one proposed in our previous work on Paris. We conclude that matrix and FGRs accreted a similar type of dust but FGR material was affected by thermal modification and compaction contemporary with their accretion. For each chondrite, dust accreted onto chondrules under different conditions (dust density, temperature) which led to diverse degrees of compaction/thermal modification of the sub-domains and explain the textural differences observed in FGRs. They accreted on chondrules in a warm environment related to the chondrule formation episode, whereas matrix accreted later in a cooler environment.

A novel indirect solar receiver/volatile extractor concept was considered for thermally extracting H2O(s) from lunar regolith in the permanently shadowed regions on the Moon. The modeled indirect solar receiver/H2O(s) extractor consisted of a rigid, highly conductive chamber that was partially embedded in the lunar surface. Solar selective and non-selective absorbers were examined to efficiently capture concentrated solar irradiation and effectively transfer heat to icy regolith to drive H2O sublimation. A detailed heat and mass transfer model was developed in ANSYS Fluent to assess the feasibility of thermal extraction from permanently shadowed regions near the lunar poles with 5 wt% of H2O(s). The maximum H2O(v) collected after 10 terrestrial h of simulation time was 2789 g for the solar selective coated receiver and 1035 g for the non-selective receiver. The addition of a solar selective coating was observed to significantly enhance H2O(s) thermal extraction. The low lunar regolith thermal conductivity was shown as the major bottleneck for thermal extraction.

Understanding the relationship between the coal structure and its reactive behaviour is of great significance to achieve clean coal conversion and its efficient utilisation. One of the key tasks is to elucidate the molecular structure and chemical bonding information of coal. Owing to the complexity of the chemical structure of coal, studies on the molecular structure of coal, especially coal models with complex particle structures of different sizes for bituminous coal from northwest China, are highly warranted. In this work, the molecular structure characteristics and chemical index of a Qinghua bituminous coal sample collected from the Ningdong area, China, were assessed. Using a combination of material characterization, computation, and molecular modelling methods, a standard method for modelling complex coal structures from single molecules of macerals to particles of various sizes was developed. The single molecular structure of vitrinite and inertinite present in Qinghua coal can be expressed as C269H196N4O13S and C255H179N3O14S, respectively. Then, a series of complex particle models of various sizes were established based on the single molecular structure models of vitrinite and inertinite. Among these models, the size of the complex particles was as large as 11 nm, with the total atomic number approaching 60,000. Furthermore, the energetic and structural features of the complex coal particle structures were also explored based on their energy decomposition and radial distribution function analysis. In addition, the chemical structure index analysis was performed for different coal macerals to further understand the internal relationship between its structure and application.

This paper introduces a new technique that enables considering the impact of soil fabric on microstructure of internally unstable gap-graded soil. The influence of soil fabric on erodibility of fine particles was studied by transferring the real soil fabric from a micro-computed tomography (μCT) image to discrete element method (DEM) using a new image processing workflow. The pair correlation function (PCF), a two-point correlation between particles in images, was used as a microgeometrical parameter to assess the impact of image filters on the quality of the μCT image. Comparison between PCF and particle size distribution of the raw μCT and reconstructed images suggest that anisotropic diffusion and non-local mean filters reproduce the real soil fabric samples most effectively. DEM results showed lower coordination number but slightly higher stress reduction factor for the real fabric, indicating that the real contact geometry results in having fine particles more involved in force network.

The permeability is one of the intrinsic parameters that determines the fluid flow in the porous media. The permeability in hydrate-bearing sediments affects the gas recovery and production of hydrate reservoirs significantly. The irregular permeability characteristics are challenging for fine-grained hydrate-bearing sediments. In this study, a series of experiments was conducted using a one-dimensional pressure vessel to investigate the hydrate formation characteristics and the permeability in hydrate-bearing fine quartz sands (volume weighted mean diameter was 36.695 μm). Hydrate saturations (0–26% in volume) were controlled and calculated precisely based on the amount of injected water and gas, the system pressure and temperature. The results indicated that the hydrate nucleation induction period was completed during gas injection, and the average time of hydrate formation was within 500 min. The permeability of methane hydrate-bearing fine quartz sands was investigated by steady gas volume flow. For hydrate saturation lower than 13.94%, the hydrate mostly formed in grain-coating, the permeability reduction exponent calculated by Parallel Capillary, Kozeny Grain Coats and Simple Cubic Filling models were 2.00, 2.10 and 1.74 respectively, and Simple Cubic Filling model was in accordance with the experimental data best. However, for hydrate saturation ranged from 13.94% to 25.91%, the permeability increased due to the flocculation structure formation of fine quartz sands and hydrate, which caused the increase of effective porosity. A new relationship among hydrate saturations, effective porosity, the ratio of permeability in the presence and the absence of hydrate was developed. This study developed the mathematical models for predicting the permeability with hydrate saturation in fine quartz sands, which could be valuable for understanding the characteristics of hydrate-bearing fine-grained sediments.

Gas hydrates are large energy resources with estimated global reserves of approximately 500–10 000 Gt of carbon, which can be extracted from underground reservoirs. In addition, such reservoirs can...

Naturally occurring volcanic glassy rocks, obsidians, are widely used for medical tools and have great interests in alternative medicine, auxiliary therapy, spa, cosmetics and jewellery fields. In this paper, we studied the spectroscopic and radiation shielding properties of obsidian samples collected from four main volcanic regions, named as Nemrut Mountain, Erzurum-Pasinler, Kars-Sarikamis and Rize-Ikizdere, eastern Turkey. In this regard, important and effective spectroscopic techniques; Electron paramagnetic resonance, X-ray diffraction, Fourier transform infrared spectrometry, Raman spectroscopy, Energy dispersive spectroscopy and Scanning electron microscopy were used to give information about structural, magnetic and morphological features of the obsidians. Additionaly, radiation shielding potentials of the obsidians were evaluated by determination of mass attenuation coefficients, effective atomic numbers, and buildup factors. Recently developed EpiXS code was used for obtaining radiation shielding parameters. It is concluded that the studied obsidians can be considered as radiation shielding materials. By this comprehensive study, both spectroscopic and shielding properties of obsidian samples from different volcanic regions in Turkey are presented and compared.

We have analyzed 14 impact melt glass samples, covering the compositional range from highly felsic to mafic/basaltic, as part of our effort to provide mid-infrared spectra (7–14 µm) for MERTIS (Mercury Radiometer and Thermal Infrared Spectrometer), an instrument onboard of the ESA/JAXA BepiColombo mission. Since Mercury was exposed to many impacts in its history, and impact glasses are also common on other bodies, powders of tektites (Irghizite, Libyan Desert Glass, Moldavite, Muong Nong, Thailandite) and impact glasses (from the Dellen, El'gygytgyn, Lonar, Mien, Mistastin, and Popigai impact structures) were analyzed in four size fractions of (0–25, 25–63, 93–125 and 125–250 µm) from 2.5 to 19 µm in bi-directional reflectance. The characteristic Christiansen Feature (CF) is identified between 7.3 µm (Libyan Desert Glass) and 8.2 µm (Dellen). Most samples show mid-infrared spectra typical of highly amorphous material, dominated by a strong Reststrahlen Band (RB) between 8.9 µm (Libyan Desert Glass) and 10.3 µm (Dellen). Even substantial amounts of mineral fragments hardly affect this general band shape. Comparisons of the SiO2 content representing the felsic/mafic composition of the samples with the CF shows felsic/intermediate glass and tektites forming a big group, and comparatively mafic samples a second one. An additional sign of a highly amorphous state is the lack of features at wavelengths longer than ∼15 µm. The tektites and two impact glasses, Irghizite and El'gygytgyn respectively, have much weaker water features than most of the other impact glasses. For the application in remote sensing, spectral features have to be correlated with compositional characteristics of the materials. The dominating RB in the 7–14 µm range correlates well with the SiO2 content, the Christiansen Feature shows similar dependencies. To distinguish between glass and crystalline phases of the same chemical composition, a comparison between CF the SCFM index (SiO2/(SiO2 + CaO + FeO + MgO)) ( Walter and Salisbury [1989 ] J. Geophys. Res., 94, 9203–9213) is useful, if chemical compositional data are also available.

The active material of power ultrasonic transducers is a ferroelectric ceramic. The methods of characterization of these materials from resonance are a key issue in the transducer design. Worldwide regulations require lead zirconate titanate (PZT) piezoceramics to be substituted due to the hazards of PbO at the processing and lifetime of these materials. The main “lead-free” families are bismuth-layered structure ferroelectrics, solid solutions based on alkaline niobates (KNbO 3 -NaNbO 3 or KNN), and those based on bismuth sodium titanate (Bi 0.5 Na 0.5 TiO 3 or BNT). New compositions and oriented grain ceramics are also under study. To date there is not a direct replacement for PZT and the most appropriate lead-free composition is used for each application.

Various processes leading to inorganic scaling and formation damage are discussed. Special attention is given to formation damage caused by the adverse reactions encountered during acid stimulation, brine incompatibility in seawater injection for water flooding, precipitation caused by carbon dioxide (CO2) and light hydrocarbon gases near wellbore, and sulfur deposition. The alterations of thermodynamic and chemical balances in favor of precipitation, precipitate aggregation, crystal growth, and inorganic scale formation are discussed and mathematically formulated. The rate processes governing the cation exchange, adsorption/desorption, and dissolution/precipitation reactions are formulated. The criteria for precipitate forming conditions are derived. Typical applications to above mentioned inorganic precipitation and scale formation processes are presented.