Hasil untuk "Mineralogy"

M. Bolton

J. Six, K. Paustian, E. T. Elliott et al.

F. Frey, D. Green

P. Scicluna, S. Zeegers, J. P. Marshall et al.

As astronomy advances and data becomes more complex, models and inference also become more expensive and complex. In this paper we present {\sc ampere}, which aims to solve this problem using modern inference techniques such as flexible likelihood functions and likelihood-free inference. {\sc ampere}\ can be used to do Bayesian inference even with very expensive models (hours of CPU time per model) that do not include all the features of the observations (e.g. missing lines, incomplete descriptions of PSFs, etc). We demonstrate the power of \ampere\ using a number of simple models, including inferring the posterior mineralogy of circumstellar dust using a Monte Carlo Radiative Transfer model. {\sc ampere}\ reproduces the input parameters well in all cases, and shows that some past studies have tended to underestimate the uncertainties that should be attached to the parameters. {\sc ampere}\ can be applied to a wide range of problems, and is particularly well-suited to using expensive models to interpret data.

Yuri Sergeevich Kostylev, Alexandra Vasilievna Tikhomirova

The article examines the names of minerals derived from toponyms found in the Urals. The material for the study was sourced from specialized works on the mineralogy of the region, Russia, and the world. The aim of the research is to analyze the word-formation patterns characteristic of detoponymic mineral names, both in motivational and formal terms. The detoponymic pattern ranks as the second most frequent for mineral names, accounting for 21% of the total number of Ural mineral names (with the most frequent pattern being the deanthroponymic one). Given the diversity of the mineral nomenclature in the Urals, it can be inferred that this ratio is applicable to official scientific mineralogy in general. The most common way of forming a detoponymic mineral name involves using the name of a place directly associated with mining as the base lexeme, typically in its full initial form, followed by the addition of the typical mineral name suffix -it. The name of a man-made object (such as a mining site) is most frequently used as the donor token. In the motivational aspect, deviations from this pattern are rare, occurring when the mineral is named not after the place of discovery, but a neighboring object. Additionally, several minerals are named after celestial bodies. In the formal aspect, deviations manifest as various modifications of the base lexeme (often through truncation), which results in the formation of a compact and user-friendly term. These deviations, both motivational and formal, are linked to the desire to create a euphonic term that fits into the scientific terminological system and avoids ambiguity. The mineral names examined reveal a tendency to associate the resulting term with a significant place for the name-giver and the professional community. Moreover, naming based on mining enables specialists to draw conclusions about the mineral’s characteristics from its name.

Mateusz Pawłowski, Damian Pietrusiak, Jakub Wróbel et al.

The determination of the dynamic angle of repose (DAR) of lunar regolith simulants is essential for modeling material behavior during in situ resource utilization (ISRU) processes and lunar surface operations. This study presents a methodology and dedicated test rig employing digital image processing to measure DAR for seven lunar regolith simulants, representing both Mare and Highland regions. Experiments were conducted under terrestrial gravity at rotational drum speeds of 2, 5, and 10 RPM, with standardized material fill and image capture procedures. For each simulant, lower, higher, and total DAR values were recorded, indicating complex dependencies on particle size distribution, mineralogy, and rotational speed. These measurements provide a critical dataset for numerical model calibration and the simulation of regolith handling systems under lunar conditions. The findings emphasize the necessity of selecting appropriate DAR parameters based on regolith type and operational scale to ensure accurate predictions of granular flow behavior in extraterrestrial environments.

Haiqi Li, Song Li, Dazhen Tang et al.

Abstract The Longtan Formation in Sichuan Basin is a new field and new strata for the exploration and development of coal measure gas, and the evaluation of geochemical and geological conditions is lacking. In this study, elemental geochemistry, mineralogy, organic geochemistry of source rocks (organic matter type, abundance, maturity), and only geophysical analysis of bulk rock (Low-temperature nitrogen adsorption, Mercury intrusion, and nuclear magnetic resonance) were performed to determine the reservoir pore structure and source-reservoir geological-geochemical controlling factors. Geochemistry and mineralogy reveal frequent shale and tuffaceous sandstone interbeds in the southern Sichuan Basin under the Emeishan igneous rock provenance supply and relatively oxic environment. The low input of terrigenous clastics, dysoxic and suboxic or anoxic environment and frequent transgression in the central Sichuan Basin have led to frequent coal-shale interbedding. The organic matter type of the source rock is type III kerogen, which is in the stage of high-over maturation, with high TOC content and excellent hydrocarbon generation potential. The coal seam in the central Sichuan Basin has good reservoir properties (porosity 9.25%, pore volume 4.74cm3/g), and the low permeability (5 × 10-3mD) of the shale caprock has good sealing ability. Overall, the coal-shale interbeds constitute the basic source-reservoir configuration of superimposed gas reservoir, and form a favorable development interval for coal measures.

Siyi Xu, Laura K. Rogers, Simon Blouin

White dwarf planetary systems provide a unique way to measure the bulk composition of exoplanetary material. Extrasolar asteroids/comets/moons which have survived the evolution of their host star can end up in the atmosphere of the white dwarf. Asteroids and boulders appear to be the most common pollutants, where we use the term "asteroids" to refer to the parent body that is polluting the atmosphere. The presence of the planetary material is detected via absorption lines of heavy elements. White dwarfs with these absorption features are called "polluted" white dwarfs. Polluted white dwarfs were expected to be rare objects because white dwarfs have high surface gravities, therefore, these heavy elements will settle out of the white dwarf's atmospheres in a short amount of time (Paquette et al. 1986). However, high-resolution spectroscopic surveys found that 25-50% of white dwarfs are polluted (Zuckerman et al. 2003, 2010; Koester et al. 2014). The mechanism responsible for making a polluted white dwarf must be common and efficient. There is strong theoretical and observational evidence that white dwarfs are accreting from planetary material. There are different mechanisms that can deliver exoplanetary material into the Roche lobe of the white dwarf. Debris disks, transits from disintegrating bodies, and intact planets have all been detected around white dwarfs (e.g., Jura et al. 2007; Vanderburg et al. 2015, 2020). This chapter will describe how the chemical autopsies are conducted, and what is learnt about exoplanetary material from polluted white dwarfs.

Dante S. Lauretta, Harold C. Connolly,, Joseph E. Aebersold et al.

On 24 September 2023, the NASA OSIRIS-REx mission dropped a capsule to Earth containing approximately 120 g of pristine carbonaceous regolith from Bennu. We describe the delivery and initial allocation of this asteroid sample and introduce its bulk physical, chemical, and mineralogical properties from early analyses. The regolith is very dark overall, with higher-reflectance inclusions and particles interspersed. Particle sizes range from sub-micron dust to a stone about 3.5 cm long. Millimeter-scale and larger stones typically have hummocky or angular morphologies. A subset of the stones appears mottled by brighter material that occurs as veins and crusts. Hummocky stones have the lowest densities and mottled stones have the highest. Remote sensing of the surface of Bennu detected hydrated phyllosilicates, magnetite, organic compounds, carbonates, and scarce anhydrous silicates, all of which the sample confirms. We also find sulfides, presolar grains, and, less expectedly, Na-rich phosphates, as well as other trace phases. The sample composition and mineralogy indicate substantial aqueous alteration and resemble those of Ryugu and the most chemically primitive, low-petrologic-type carbonaceous chondrites. Nevertheless, we find distinct hydrogen, nitrogen, and oxygen isotopic compositions, and some of the material we analyzed is enriched in fluid-mobile elements. Our findings underscore the value of sample return, especially for low-density material that may not readily survive atmospheric entry, and lay the groundwork for more comprehensive analyses.

Eloy Peña-Asensio, Álvaro-Steve Neira-Acosta, Juan Miguel Sánchez-Lozano

The selection of a landing site within the Artemis Exploration Zone (AEZ) involves multiple factors and presents a complex problem. This study evaluates potential landing sites for the Artemis III mission using a combination of Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methodologies, specifically the TOPSIS algorithm. By integrating topographic, illumination, and mineralogy data of the Moon, we assess 1247 locations that meet the Human Landing System (HLS) requirements within 13 candidate regions and Site 004 near the lunar south pole. Criteria considered include surface visibility, HLS-astronaut line of sight, Permanently Shadowed Regions (PSRs), sunlight exposure, direct communication with Earth, geological units, and mafic mineral abundance. Site DM2 (Nobile Rim 2), particularly the point at latitude 84°12'5.61" S (-84.20156°) and longitude 60°41'59.61" E (60.69989°), is the optimal location for landing. Sensitivity analysis confirms the robustness of our approach, validating the suitability of the best location despite the MCDM method employed and variations in criteria weightings to prioritize illumination and PSRs. This research demonstrates the applicability of GIS-MCDM techniques for lunar exploration and the potential benefits they can bring to the Artemis program.

Norman Wagner, Frank Daschner, Alexander Scheuermann et al.

The frequency dependence of dielectric material properties of water saturated and unsaturated porous materials such as soil is not only disturbing in applications with high frequency electromagnetic (HF-EM) techniques but also contains valuable information of the material due to strong contributions by interactions between the aqueous pore solution and mineral phases. Hence, broadband HF-EM sensor techniques enable the estimation of soil physico-chemical parameters such as water content, texture, mineralogy, cation exchange capacity and matric potential. In this context, a multivariate (MV) machine learning approach (principal component regression, partial least squares regression, artificial neural networks) was applied to estimate the Soil Water Characteristic Curve (SWCC) from experimentally determined dielectric relaxation spectra of a silty clay soil. The results of the MV-approach were compared with results obtained from empirical equations and theoretical models as well as a novel hydraulic/electromagnetic coupling approach. The applied MV-approach gives evidence, (i) of a physical relationship between soil dielectric relaxation behavior and soil water characteristics as an important hydraulic material property and (ii) the applicability of appropriate sensor techniques for the estimation of physico-chemical parameters of porous media from broadband measured dielectric spectra.

Sadaf Maramizonouz, Sadegh Nadimi, William Skipper et al.

In the UK Network Rail Environmental Sustainability Strategy 2020-2050, minimal waste and the sustainable use of materials are highlighted as core priorities. The ambition is to reuse, repurpose or redeploy all resources. In low adhesion conditions, sand particles are used to enhance traction throughout the network. However, sand is in danger of becoming scarce as many applications demand it. In this study, an alternative adhesion-enhancing particle system made of recycled crushed glass is examined in terms of density, size, shape distribution, mineralogy, mechanical properties, and bulk behaviour to better understand their characteristics in comparison with the typical Great British rail sand currently in use and reported in the literature. Their effects on tribological behaviour and surface damage are also investigated using the High-Pressure Torsion test in dry, wet, and leaf-contaminated conditions. Both particle characterisation and tribological testing show promising results. Recycled glass particles provide an acceptable level of traction with a similar level of rail damage as typical rail sand. It is suggested to perform full-scale laboratory and field tests to further confirm this material's suitability.

Junjie Dong

Nominally anhydrous minerals (NAMs) are the primary carriers of water in rocky planet mantles. Therefore, studying water solubilities of major NAMs in the mantle can help us estimate the water storage capacities of rocky planet mantles and indirectly constrain the actual water contents of their interiors. By using data science methods such as statistics and statistical learning algorithms, in this paper, current modeling studies on the mantle water storage capacities of Earth, Mars, and exoplanets have been introduced and summarized. Firstly, the thermodynamic model for mantle water storage capacity has been reviewed. Then, based on the two case studies on Earth and Mars, how to translate atomic-scale experimental data of water solubility and their measurement errors into planetary-scale models of mantle water storage capacity has been explored by using robust regression, Monte Carlo methods, and bootstrap aggregation algorithms. Thirdly, how the large sample data from the exoplanet observational campaigns can help us understand the statistical properties of the mantle water storage capacities of rocky exoplanets has been introduced. Finally, the application limitations of data science methods in mineral physics research have been discussed, and how to better combine statistics and statistical algorithms with mineral physics data research has been prospected.

Halim Mutlu, Zehra Deveci Aral, Sevilay Tan et al.

Basins formed on active strike-slip faults are important prospect areas for geothermal energy exploration since the crust gets thinner in these areas and tectonic structures provide favorable conditions for heat-fluid circulation and transport. The Edremit (Balıkesir) Basin holds a great promise for the discovery of new geothermal energy sources. The objective of the recent study is to evaluate the geothermal capacity of the Edremit Basin utilizing tectonic, geological, and hydrogeological studies, combining remote sensing (land surface temperature-LST, hydrothermal alteration, and multi-temporal InSAR (MT-InSAR) assessments). We present structural literature data and the results of field mapping, which revealed the geometry, kinematics, and dynamics of structural features, geological units as geothermal system components, thermal and cold water chemistry, and thermal infrared remote sensing analysis. For the purpose of assessing new targets and recent geothermal capacity, these data are combined and evaluated. According to the outcomes of the study, the fault pattern in the Edremit Basin is generated by N-S extension, which produced E-W dominant striking normal faults with a heritage of paleostructures oriented in various directions. According to remote sensing analyses, the primary LST regions in the basin are defined by the active faults. Therefore, a high sodium sulfate ratio recorded in the chemical analyses of the water samples indicates a deep circulation and high possibility for the presence of thermal water. Consequently, our findings are consistent with the work to include thorough field geology surveys, structural patterns, LST, and water chemistry to refined exploration process.

Anna Rogowitz, Marcel Thielmann, Katrin Kraus et al.

Abstract We performed deformation experiments on omphacite‐garnet aggregates at a temperature of 1000°C, a confining pressure of 2.5 GPa, and a strain rate of 3 × 10−6 s−1 and complemented them by numerical simulations to gain insight into the role of garnet fraction for the deformation behavior of dry eclogite, with a focus on strain weakening mechanisms. We determined the spatial and temporal evolution of strain and strain rate by basing numerical simulations on experimentally derived microstructures, and thereby identified characteristic deformation mechanisms. Pure omphacite and garnet aggregates deform by two different mechanisms. Internally strained clasts and low‐angle grain boundaries indicate crystal plasticity for omphacitite; the fracture dominated fabric of garnetite documents brittle deformation. Electron channeling contrast imaging, however, revealed low‐angle grain boundaries and free dislocations in garnet crystals, suggesting that minor crystal plasticity accompanies the brittle failure. Eclogitic aggregates show varying deformation behavior between the two end‐members shifting from crystal plastic toward brittle deformation with increasing garnet content. All samples exhibit strain weakening. The intensity of weakening shows a positive correlation with the garnet content. Our combined experimental, numerical, and microstructural investigations suggest that the majority of strain weakening is associated with crystal plastic processes in omphacite. Numerical simulations and experiments show that a garnet content above 25% enhances the activity of crystal plastic processes in omphacite and results in strain localization, which subsequently weakens the eclogite.

Zixuan Wang, Xiaoqing He, Bo Xu et al.

Green diopside is currently popular in the jewelry market due to its attractive color and excellent transparency. Gem-quality diopsides are mainly sourced from Pakistan, Italy, Russia, and other places. The color, geographic origin, and formation mechanism are the main factors affecting the value of gemstones, which can be determined by examining their gemology and composition characteristics. This study systematically characterizes the standard gemology of green diopsides from Pakistan and Russia and compares them with the blue diopsides produced within the skarn process and the diopsides from the nearby region in Russia from previous studies by gemological microscopy, spectral testing (infrared, Raman and ultraviolet-visible spectroscopy), and chemical analyses (electron probe and laser ablation inductively coupled plasma mass spectrometry). The results show that the spectral characteristics and phase composition of the green diopside samples from Pakistan and Russia have excellent uniformity and similarity. The high Cr, Fe, V, and Ni contents are the reasons why they appear as green. Meanwhile, the elemental characteristics of the diopside are effective tools for distinguishing different origins of different diopsides. The Russian green diopsides have higher contents of Sr, Sc, Zr, and rare earth elements (REE), indicating that they are related to alkaline ultrabasic rocks, and the source of the diopside sample from Pakistan is metamorphic rock.

Nabil Ibtehaz, Muhammad E. H. Chowdhury, Amith Khandakar et al.

Raman spectroscopy provides a vibrational profile of the molecules and thus can be used to uniquely identify different kind of materials. This sort of fingerprinting molecules has thus led to widespread application of Raman spectrum in various fields like medical dignostics, forensics, mineralogy, bacteriology and virology etc. Despite the recent rise in Raman spectra data volume, there has not been any significant effort in developing generalized machine learning methods for Raman spectra analysis. We examine, experiment and evaluate existing methods and conjecture that neither current sequential models nor traditional machine learning models are satisfactorily sufficient to analyze Raman spectra. Both has their perks and pitfalls, therefore we attempt to mix the best of both worlds and propose a novel network architecture RamanNet. RamanNet is immune to invariance property in CNN and at the same time better than traditional machine learning models for the inclusion of sparse connectivity. Our experiments on 4 public datasets demonstrate superior performance over the much complex state-of-the-art methods and thus RamanNet has the potential to become the defacto standard in Raman spectra data analysis

Alfonso Alogo Nguema-Mozoho, Maday Cartaya-Pires, Gilberto Sargentón-Romero et al.

Blasting and drilling methods are mainly used in basalt rock quarries as blasting-digging methods. The purpose of this study is to argue the validity of using a jackhammer as a rock removal method in Gabricar quarry, based on knowing the geomechanical parameters of rocks as well as the technical-economic indicators for exploitation. Gravimetric, saturation, hydrostatic weighing, pycnometric and axial loads methods were used to obtain physical-mechanical properties of the rocks and geological survey, volumetric joint count, and strength coefficient were used to establish crack elements, block size, and rock mass quality, respectively. 4.75% humidity; 2.39% porosity; 5.73 g/cm3 volumetric mass; density of 26.44 g/cm3 and axial compressive strength of 173.53 Mpa as average values of physical-mechanical properties were obtained. Four families of cracks with spacing of 0.4m, 0.6m; 0.3m and 0.2m and 18mm openings; 13mm; 3mm and 9mm, respectively were established. Blocks are small and the rocky massif is of good quality. The technical-economic analysis showed the efficiency of the jackhammer as a blasting-based digging method in Gabricar quarry.

C. Thomas, L. J. Cobden, A. R. T. Jonkers

Abstract Polarities of seismic reflections at the discontinuity atop the D" region (PdP and SdS) indicate the sign of the velocity contrast across the D" reflector. Recent studies found PdP polarities matching and opposite those of P and PcP. While anisotropy could explain this behavior, we find that the ratio of the change in S wave velocity over change in P wave velocity (R‐value) can influence polarity behavior of D" reflected P waves. For R‐values exceeding 3, the P wave reverses polarity in the absence of anisotropy while S wave polarity is not influenced by the R‐value. Using sets of one million models for normal mantle and MORB with varying minerals and processes across the boundary, we carry out a statistical analysis (Linear Discriminant Analysis) finding that there is a marked difference in mantle mineralogy to explain R‐values larger and smaller than 3, respectively. Based on our results we can attribute different mineralogy to a number of cases. In particular, we find that when velocities increase across D" and polarities of PdP and SdS are opposite the post‐perovskite phase transition is still the best explanation whereas MORB is the best explanation when PdP and SdS are the same. When the velocities are decreasing, the post‐perovskite phase transition within MORB is the best explanation if PdP and SdS polarities are the same but if PdP and SdS are opposite, our results indicate that primordial material or mantle enriched in bridgmanite can explain the polarity behavior, further constraining mineralogy within the large low seismic velocity provinces.

A. Santhana Krishna Kumar, Jolanta Warchol, Jakub Matusik et al.

Abstract Numerous adsorbents have been introduced to efficiently remove heavy metals and organic dyes from environmental water samples. However, magnetic a porous network aerogels are rarely developed to capture inorganic and organic pollutants from aqueous. We herein fabricated hexagonal boron nitride nanosheets (h-BNNSs)-based on magnetic hybrid aerogels (MHAs) as a lightweight adsorbent for robust uptake of Cr(VI), As(V), methylene blue (MB) and acid orange (AO). The synthetic procedure of poly(ethyleneimine)-modified h-BNNSs (PEI-h-BNNSs) involved thermal poly condensation of melamine and boric acid, pyrolysis of the resultant products which allowed exfoliated by ultra-sonication process further functionalization with PEI-mediated modification of h-BNNSs. The as formed PEI-h-BNNSs allowed in-situ formation of magnetite nanoparticles (Fe3O4 NPs) decorated on their surfaces, which are turned to be PEI-h-BNNSs@Fe3O4 NPs. The lyophilization treatment of PEI-h-BNNSs@Fe3O4 NPs-loaded PVA hydrogels generated the MHAs with large porous structures, diverse and numerous functional groups, good super-paramagnetic and a zero net surface charge. These features enabled the proposed adsorbent (MHAs) to be utilized to efficiently remove Cr(VI), As(V), MB, and AO from an aqueous solution, with maximum adsorption capacity estimated to be 833, 426, 415, 286 mg g−1, respectively. The adsorption kinetics and isotherm data demonstrated that MHAs mediated adsorption of Cr(VI), As(V), MB and AO followed the Freundlich isotherm model and a pseudo-second-order kinetics model. This finding signifies that the MHAs exhibit heterogeneous binding behavior with multilayer chemisorption of Cr(VI), As(V), MB and AO. Subsequently, the practical application were validated by conducting their detoxification of chromium and arsenic in soli-sludge samples.