Search

Laurus nobilis, sometimes referred to as laurel, has been used for medicinal and culinary purposes for a very long time. The main subjects of this study are the phytochemical composition, mineralogical profile, and potential antioxidant properties of Laurus nobilis in Tangier, Northern Morocco. For phytochemical analysis of methanolic extracts, high-performance liquid chromatography (HPLC-UV-MS) was used, and Fourier transformation infrared spectroscopy (FT-IR) was used to identify each individual component. Minerals were studied by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and wavelength dispersive X-ray fluorescence (WD-XRF). Total tannin, flavonoid, and phenolic amounts were quantified using aqueous and methanolic extracts. The antioxidant properties were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays. Research has revealed a complex array of phytochemicals, including tannins, flavonoids, and phenolic acids. Mineral analysis has revealed the existence of vital components that are beneficial to health. Comparing the methanolic extract to the water extract, it demonstrated higher levels of phenols, flavonoids, and tannins as well as stronger antioxidant activity, indicating greater health benefits. This comprehensive study highlights the importance of Laurus nobilis from Northern Morocco as a reliable botanic resource with potential pharmaceutical, nutritional, and cosmetic uses. [ABSTRACT FROM AUTHOR]

The study of the chemical and mineralogical composition of the agricultural soils is essential to know its process of formation. and the characteristics associated to the fertility and to the retention of nutrients as foundations for conduct its use and management. With this objective are evaluated Brown sialitic and Vertisols soils representative of the eastern region of Cuba. The technique of X-rays diffraction (DRX) was used for determine the mineralogical and chemistry composition of the predominant soils. Were calculated the oxides SiO2, Al2O3, Fe2O3 and the molecular relations SiO2 / Al2O3, SiO2 / Fe2O3 and SiO2 / R2O3 for characterize the soils. The predominant minerals in the Brown soils were in that order: calcite, quartz, montmorillonite and anortite. In the Vertisols were detected quartz, albite and vermiculite that are very resistant to the meteorism. The vertical distribution of the minerals show a degree of evolution uniform of the parent rocks. The sequence of free oxides (SiO2> Al2O3> Fe2O3) corroborated the sialitic origin of the soil profiles, associated with the predominance of minerals in a relation 2:1. The uniform distribution of the total of elements in all the profiles shows a lithogenic origin. [ABSTRACT FROM AUTHOR]

Interpersonal violence is a rising issue in global society and new approaches are being sought to combat the problem. Within this context, expanding forensic techniques to better document violent crime scenes is critical for improving and acquiring legal evidence, such as proving or tracing contact between victims and suspects. This project aims to demonstrate the potential for forensic investigations in the context of interpersonal violence using a field-based reflective spectroscopy approach. For this, a common cosmetic, Wet'N'Wild "Color Icon" blush in the shade "Pearlescent Pink", was mineralogically characterized using transmission electron microscopy and powder X-ray diffraction and subsequently investigated via reflective spectroscopy on a variety of common substrates. Differing amounts of the cosmetic product, ranging from 0.001 g to 0.075 g, were applied to a variety of substrates using a simple push method to simulate forcible contact and material transfer. Substrates included a pine wood block; (calcareous) sand from Tulum, Mexico; Ottawa sand; tile; Pergo wood; linoleum; closet material; carpets; and fabrics. The reflective spectra of cosmetic–substrate combinations were measured via an ASD FieldSpec 4 Hi-Res spectroradiometer. The Wet'N'Wild cosmetic was reliably detected on various substrates relevant to crime scenes. Minor amounts (as low as 0.02 mg/mm2) could be detected, and average limits of detection of 0.03 mg/mm2) were achieved; however, a calcareous sand (Tulum) had a high level of detection (>0.38 mg/mm2), suggesting that further investigation is needed for more complex sand substrates. The use of the ASD spectroradiometer as a forensic tool within the context of crime scene documentation shows promise. Future work should expand the characterization of cosmetic materials across a broad range of substrates and consider systematic studies of specific population groups. Furthermore, combining this approach with hyperspectral imaging at crime scenes is a promising future direction for crime scene documentation. This work therefore demonstrates a novel method for investigating cosmetics within the context of interpersonal violence and provides a foundation for future laboratory and field work using the ASD FieldSpec 4 and hyperspectral imaging systems. [ABSTRACT FROM AUTHOR]

This study investigates the possibility of reducing the efflorescence (excess or non-reactive salts) effect of inorganic polymers based on aluminosilicate materials from Jordan. This was achieved by minimizing the particle size of the raw materials, and using hydrothermal curing at 80° C, 120° C and 150° C, then comparing the results with other different curing conditions; ambient and humid. Kaolinite (K), volcanic tuff (Vt), and silica sand (Ss) raw materials were used. The raw materials were ground to the average particle sizes (d50) of: <10µm, <200nm, and <100nm. Three different mixing ratios of Vt, K, and Ss were used to study their dissolution behavior and to prepare inorganic polymers. X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma (ICP) techniques were used to identify the mineralogical and chemical composition of the raw and processed materials. The samples of <10µm were successful to be molded and analyzed for compressive strength. The average compressive strength was about 65 Mpa under hydrothermal condition cured at 150°C. The samples of nanometric size failed because the material in this range of size behaves and exhibits one or more nanoscale phenomena. Qualitative and quantitative measurements of efflorescence formation were also determined. The average alkali leaching was reduced from 3.14% of ambient cured samples to 0.83% of hydrothermally cured ones. This highest strength result indicates that the alkaline solution has reacted with the majority of Al3+ and Si4+ of silicates raw material. [ABSTRACT FROM AUTHOR]

A mineralogical and mineral chemistry study was carried out in the San Luis Alta telluride-rich gold deposit, mid-south Peru, to contribute towards determining its formation and improving the ore processing. The San Luis mineralization is considered an intrusion-related gold deposit located in the Arequipa segment of the Coastal Batholith. The mineralization occurs in quartz veins hosted in diorites and granodiorites from the Tiabaya Super-Unit. These veins are sulfide-rich in the deep areas and contain abundant iron oxides. Sulfides are mainly pyrite with minor chalcopyrite and galena. Native gold and telluride minerals are abundant. Mineral chemistry was determined using an electron microprobe. The mineralogy of veins was classified into four stages. Gold occurs in the three last stages either in large grains, visible to the naked eye, or, more frequently, in grains of less than 10 µm. Gold appears as grains encapsulated in pyrite, Fe oxides, quartz and filling fractures. The first stage is characterized by the deposition of quartz and massive pyrite, which does not contain gold. During the second stage, hessite, calaverite, petzite and altaite are formed. Additionally, Bi-tellurides, mainly volynskite, rucklidgeite, kochkarite and tellurobusmuthine, are formed. Some of these minerals occur as blebs encapsulated in pyrite, suggesting that a Bi-Te-rich melt was formed from the ore-forming hydrothermal fluid and transported the Au and Ag elements. This stage was followed by a fracturing event and tellurobismuthite, tetradymite and montbrayite precipitated. In the last stage, a supergene replacement formed covellite, bornite and goethite. Te-Bi minerals do not appear in this stage, but selenium minerals occur in minor amounts. Chlorargyrite and iodargyrite occur and are associated with gold. [ABSTRACT FROM AUTHOR]

Different ore deposit types may evolve from a common magmatic-hydrothermal system. Establishing a genetic link between different deposit types in an ore cluster can not only deepen the understanding of the magmatic-hydrothermal mineralization process but can also guide exploration. Both the Nihe iron-oxide–apatite (IOA) deposit and the Shaxi porphyry Cu–Au deposit in the Lower Yangtze Valley, Anhui, Southeast China, formed in the Luzong Cretaceous volcanic basin at ~130 Ma. We examined a temporal–spatial and potential genetic link between these deposits based on stratigraphic lithofacies sections, biotite and clinopyroxene mineralogical chemistry, zircon chronology, Hf isotopes, and trace elements. Stratigraphy, petrology, mineralogical chemistry, and available fluid inclusion results support that the emplacement depth of the Nihe ore-related porphyry is shallower than that of the Shaxi porphyry. The magmatic zircon and hydrothermal zircon from Nihe provided U–Pb ages of 130.6 ± 0.7 Ma and 130.7 ± 0.7 Ma, respectively. The magmatic zircon U–Pb age (130.0 ± 0.8 Ma) of Shaxi overlaps with its molybdenite Re–Os age (130.0 ± 1.0 Ma). The agreement between the mineralization and porphyry emplacement ages of Nihe and Shaxi indicates a temporal coincidence and supports a possible genetic link between the two deposits, considering their close spatial relationship (in the same ore district, 15 km). The zircon Hf isotopes and trace elements support the evolution of both deposits from an enriched lithospheric mantle, although the Shaxi deposit may have experienced contamination of the Jiangnan-type basement. Both deposits lie above the fayalite-magnetite-quartz buffer, but the Nihe magmatic zircons are of lower temperature and less oxidized than that of Shaxi. The much higher Eu/Eu* and Yb/Dy values of zircons from Shaxi are likely caused by the suppression of early plagioclase crystallization and the prevalence of amphibole fractionation, thus indicating more hydrous content of the Shaxi ore-related magma. Additionally, the Shaxi ore-related porphyry has higher zircon Hf concentrations, suggesting that the porphyry Cu–Au deposit has experienced a greater degree of magma fractionation. Our study highlights that the Nihe IOA deposit and the Shaxi porphyry Cu–Au deposit have a common magma source, while different extent of crust contamination, magma oxidation state, hydrous content, and degree of magma fractionation collectively result in the two distinct ore deposits. This possible genetic link suggests a great potential of porphyry Cu–Au-PGE mineralization in the Middle–Lower Yangtze River metallogenetic belt, especially in the deep part of the IOA district in the Luzong Cretaceous volcanic basin. [ABSTRACT FROM AUTHOR]

Sediment-derived granites (S-type) can provide detailed information about continental crust reworking processes and tectonic regimes through time. Their compositions reflect the nature of sedimentary rocks that melted to form them. Inherited accessory minerals in these granites can provide information regarding the age and nature of the crustal rocks that contributed to the formation of their sedimentary source rock. In addition, S-type granites typically form during collisional stages in modern orogens, and their Precambrian records can provide clues about ancient tectonics. In this contribution, we present a detailed petrogenesis of the Cupim Pluton, located in the Paleoproterozoic Mineiro Belt (Brazil). The Cupim pluton is composed of two-mica and garnet-bearing leucogranites that are strongly peraluminous (ASI > 1.1), high-K (K 2 O/Na 2 O > 1), low MgO + FeO + TiO 2 (<2 wt%). Its composition is similar to that of melts experimentally produced by muscovite/biotite dehydration melting reactions. Rb/Sr and Rb/Ba ratios suggest that these leucogranites are formed by the melting of heterogeneous sedimentary source(s). Zircon crystals from the Cupim Pluton unveil a protracted crustal melting period (2.01–1.98 Ga) hitherto unknown in the Mineiro Belt, which itself discloses a late collisional orogenic stage in southern São Francisco Craton. Igneous zircon crystals exhibit εHf (t) between −16.4 and − 0.6, and δ30Si between −1.16 and − 0.26 ‰, which is typical for zircon from sediment-derived granites. Hafnium isotope variations reflect mixing between at least two crustal sources, which is in line with inherited zircon cores that evidence major Archean and minor Paleoproterozoic sediment contributions. The emplacement of the Cupim Pluton leucogranites ends a subduction-collision cycle, following a long period of TTG-sanukitoid magma production, and promoted the stabilization of the southern São Francisco Craton. [Display omitted] • Cupim Pluton is composed of sediment-derived (two-mica and garnet-bearing) granites. • Whole-rock and mineralogical chemistry diversity point to source heterogeneity. • 2000 Ma zircons mark the collisional event in the Southern São Francisco Craton. • Inherited zircons reveal Archean contribution to Paleoproterozoic sedimentary basins. • Zircon Hf-Si isotope compositions attest to crust reworking and source mixing. [ABSTRACT FROM AUTHOR]

We inferred hydrological changes in Lake Petén Itzá (Guatemala) during Marine Isotope Stages (MIS) 3-2 using geochemical (Ti, Ca/Ti+Al+Fe ratio and Mn/Fe) and mineralogical (carbonates, gypsum, quartz, clay) data from sediment core PI-2 to reconstruct changes in runoff, lake evaporation, organic matter sources and potential oxic/anoxic conditions associated with variations in water-level during the last ~59 cal ka BP. Early MIS3 (57.0–52.5 cal ka BP) was dominated by relatively wet conditions, higher lake primary productivity and anoxic waters, which persisted into the subsequent interval (52.5–39.0 cal ka BP), except for two periods of possible low water-level at 52 and 46 cal ka BP when our data suggest higher evaporation, high terrestrial organic matter input and persistent oxic conditions. Towards the end of MIS3 and start of MIS2 (39.0–23.0 cal ka BP), lake evaporation increased considerably, as did inputs of terrestrial organic matter, and waters became more oxic as water-levels dropped and the site moved from the hypolimnion to the epilimnion. These conditions reversed during the Last Glacial Maximum (23.0–18.0 cal ka BP) when runoff and lake productivity increased and waters again became anoxic as a result of rising water-levels. Refining the age-depth model for the Site PI-2 also allowed the correlation to Greenland Interstadials (GI14-2), Greenland Stadial (GS14-2) and Heinrich Stadials (HS5-1). HS and GS were characterized by increases in Ca/Ti+Al+Fe ratios and gypsum content generally indicative of drier conditions. GS13, 9 and 5 showed the driest conditions associated with the contemporaneous establishment of HS5-3, respectively. In contrast, GI show high Ti values which suggests relatively greater runoff and overall wetter conditions compared with GS and HS, with the most marked GI peaks between 40 and 30 cal ka BP. This runoff variability is in accord with shifts in the average position of the Intertropical Convergence Zone and strength of the Atlantic Meridional Oceanic Circulation during the Late Pleistocene. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quantitative reconciliation of mineralogical data with leachate dynamic. • Investigation of mine waste rock water content on weathering. • Decrease in leachate pH at lower water saturation. • Carbonate phase size reduction with increase in water saturation. Water content plays a critical yet ambivalent role in the physical and geochemical stability of mine tailings and waste rock, but its effects on individual chemical weathering reactions (dissolution and precipitation) and bulk water quality remain poorly understood. We experimented with synthetic waste rock to quantitatively reconcile modal and textural mineralogical parameters (mineral size, association, and liberation) with leachate quality at different water saturation levels (5–100%). Leachate pH consistently decreased from a 13-week average of 6.14 at 100% saturation to 5.37 at 5% saturation. Simultaneously, mineralogical analyses revealed a reduction in the size of carbonate phases over the course of weathering, decreasing from 200 µm to 145 µm as water saturation increased from 5% to 100%, which could be a contributing factor to more alkaline pH in samples with higher water saturation. Total concentrations of iron (Fe) and copper (Cu) in solution increased with lower moisture, with Cu concentrations increasing 24-fold in samples at 5% saturation compared to full saturation. In contrast, arsenic (As) concentration increased with higher moisture levels, which we attribute to reduced galvanic protection of As-bearing pyrite from oxidation. Multivariate statistical evaluation allowed us to uncover correlations between water chemistry and mineralogical data (i.e., sulfide associations or phase perimeters) and to explain chemical differences between samples, particularly those at 100% and 5% water saturation. Our findings underscore the importance of conducting quantitative mineralogical investigations on mine waste materials and considering their stored water content in the formulation of mine waste management strategies. [ABSTRACT FROM AUTHOR]

Keywords: Phyllosilicates; glauconite; nontronite; peak shift EN Phyllosilicates glauconite nontronite peak shift 1080 1090 11 06/01/22 20220601 NES 220601 Introduction Raman spectroscopy found widespread application in the rapid and non-destructive characterization of silicate minerals ([26]; [8]; [35]; [34]; [44]; [31]; [1]; [45], 2015; [30]). Concluding remarks In this study, Raman spectroscopy analysis of nontronite and glauconite-nontronite mixed-layer phases from deep-sea hydrothermal fields reveals that these phyllosilicates have diagnostic Raman spectral features that include a series of strong peaks in the low wavenumber region (<700 cm SP -1 sp ) and the hydroxyl domain (3500-3700 cm SP -1 sp ). To fill these knowledge gaps, this study reports a comprehensive Raman spectral characterization of nontronite and glauconite-nontronite mixed-layer phases (i.e., vertical mixing/interstratification of glauconite and nontronite layers) from seafloor hydrothermal fields. Chemistry/structure-dependent Raman spectral features of glauconite and nontronite For the analyzed nontronite and glauconite-nontronite mixed-layer samples, the covariations between Raman spectral properties and octahedral chemistry (Table 2; Figs. [Extracted from the article]

Copyright of Issues of Chemistry & Chemical Technology / Voprosy Khimii & Khimicheskoi Tekhnologii is the property of Ukrainian State University of Chemical Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We conducted outcrop‐to‐nanoscale structural observations on a principal slip zone (PSZ) of the Yangsan fault, a major strike‐slip fault in southeast Korea, and some high‐velocity rotary shear tests on the PSZ gouges to understand shear localization and physico‐chemical processes in the PSZ during earthquakes. At the fault outcrop, the PSZ appears 1–2 cm thick. At smaller scales, the PSZ is subdivided into Units 1 to 4 based on their microstructures. Microscopic observations confirmed the shear localization in Units 1 (20–500 μm in thickness) and 3 (0.8–3 mm in thickness). Further localization was observed in several μm‐thick shear bands. Various structural and mineralogical features that recorded physico‐chemical processes in slip zones were found in the PSZ, including gouge fluidization structures relevant to thermal pressurization, solidified frictional melt of clay‐rich gouge, and mineralogical changes by frictional heating‐induced illitization. The gouge melting and mineralogical changes were reproduced in our experiments at 1.3 m s−1. The gouge fluidization has been observed in previous tests at seismic slip rates. Thus, the observations from the natural and experimental faults indicate that the shear localization in the PSZ was coseismic. In a cataclasite zone next to the PSZ, altered veins of pseudotachylyte were found. All these observations indicate temporal changes of the PSZ materials (e.g., formation of solidified melt, alteration of the melt into clay minerals, friction‐induced mineralogical changes). Associated with such changes, coseismic slip zone processes and dominant weakening mechanisms may also vary, even at the same location on a fault. Plain Language Summary: Shear strain may be localized into narrow zones of tectonic faults in short‐term and long‐term scales. We conducted outcrop‐to‐nanoscale structural observations on a principal slip zone (PSZ) of the Yangsan fault in southeast Korea and shear tests on fault rocks taken from the fault at 1.3 m s−1 to understand the short‐term shear localization in the fault during earthquakes. Frictional heating‐related geological records such as gouge injection structures, solidified frictional melt, and mineralogical changes were found in the principal slip zone. The frictional gouge melting and mineralogical changes were reproduced in our experiments, and the gouge injection structures were observed in previous shear tests at seismic slip rates. Thus, the natural and experimental observations indicate that the shear localization into the PSZ, which is several tens of μm to several mm in thickness, occurred during earthquakes. Further localization was also observed in several μm‐thick shear bands in the PSZ. This study gives us an idea of shear localization zone thickness in natural fault zones. Also, it shows, with changes in slip zone materials, physical and chemical processes in fault slip zones during earthquakes may vary with time, even at the same location of a fault. Key Points: Shear localization occurred in natural slip zones as thin as several μm to tens of μmGeologic records of clay‐rich gouge melting, gouge fluidization, and friction‐induced illitization indicate coseismic shear localizationWith changes in slip zone materials, coseismic slip zone processes and dominant weakening mechanisms may vary with time [ABSTRACT FROM AUTHOR]

Chemical, physical and mineralogical characterization of an industrial rice husk ash is reported and the differences with ash typically obtained by laboratory combustion of husks were highlighted. Valorization of industrial ash was targeted by controlling the combustion temperature of rice husks at 600 °C, 650 °C, 700 °C and 750 °C in an atmospheric fluidized bed industrial boiler of a paper mill. The other parameters were ash sampling points (air-preheater, economizer and electrostatic-precipitator) and the ash processing condition (as-received and ground). Irrespective of the burning temperature or sampling point, all ashes had a cellular microstructure with a high specific surface area (25 m2/g − 50 m2/g), silica content was greater than 80% with the amorphous fraction being larger than 90%. Pozzolanic reactivity of ground ash for the entire burning temperature range of 600 °C -750 °C was acceptable and a 15% replacement of cement with the processed ash in blended mortars yielded optimum strength and flow performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Initial timing of the extensional environment of the EKOB was not later than 428 Ma. • No genetic relation between highly evolved rhyolite and trachyte at Haidewula. • Strongly peraluminous volcanic rocks are favorable U-sources for mineralization. Zircon U–Pb-Hf isotopic compositions, mineralogical chemistry, and whole-rock geochemistry analyses were performed on rhyolite and trachyte from the Haidewula deposit in the East Kunlun Orogen Belt (EKOB). These analyses aimed to elucidate the genetic relationship between trachyte and rhyolite and to investigate the role of these volcanic rocks in uranium mineralization. Zircon U–Pb isotope dating indicates that the Haidewula rhyolite and trachyte were contemporaneous with emplacement ages of 421 Ma to 428 Ma, respectively. The trachyte samples exhibit high K 2 O/Na 2 O and Fe# [FeO/(FeO + MgO)] ratios, and belong to metaluminous, ferroan volcanic rock; the rhyolite samples display high A/CNK and Fe# ratios, elevated high field strength element contents, and can be classified as strongly peraluminous A 2 -type magma. Trace and major elemental geochemical signatures demonstrate that the Haidewula trachyte originated from the high-temperature partial melting of a mafic lower crust, followed by fractional crystallization of plagioclase, pyroxene, magnetite, and/or K-feldspar. On the other hand, the rhyolite was likely generated by high-temperature melting of granodiorite in a low water and mid-crust pressure environment, followed by fractional crystallization of feldspar and ilmenite. The occurrence of A-type volcanic rocks at Haidewula suggests that the initial timing of crustal extension in the EKOB was not later than 428 Ma. Overall, Paleozoic igneous rocks in the EKOB revealed that a post-collisional extensional regime, resulting from the rewelding of the microcontinents in eastern Gondwana, was responsible for intensive magmatism during the Late Silurian period. In comparison to other volcanic complexes hosting uranium deposits in eastern China, the relatively U-rich rhyolite and trachyte had the potential to contribute to the formation of U mineralization. In particular, the rhyolitic tuffaceous U-rich glassy volcanic rocks in the Haidewula deposit may represent favorable U-source rocks for mineralization, with uranium released through volcanic glass devitrification processes and leaching by oxidizing hydrothermal fluids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mineralogical and geochemical analysis of Taiji-2 subseafloor samples on the SMAR were conducted. • Mineralogical and pyrite chemistry differences between stockwork and semi-massive sulfide samples were revealed. • w and logf S2 decrease from subseafloor stockwork to semi-massive sulfide zone. • Three distinct mineralization stages were identified. In modern seafloor hydrothermal mineralization systems, subseafloor deposits are crucial alongside seafloor massive sulfides, consisting mainly of stockwork at the periphery and semi-massive sulfides at the central of subseafloor ore bodies. These two ore types exhibit contrasting mineralogical and elemental compositions, and the difference between their formation processes are unclear due to sampling challenges. The mafic-hosted Taiji-2 hydrothermal field, located on the Southern Mid-Atlantic Ridge, presents pyrite-enriched subseafloor sulfides on the seafloor, providing a good research opportunity. Our study included comprehensive analyses of mineralogy, pyrite chemistry, and in-situ sulfur isotopes through LA-MC-ICP-MS method on Taiji-2 subseafloor samples. Our findings suggest: (1) a hybrid source of ore-forming materials, (2) increased seawater involvement and decreased temperature and sulfur fugacity from the periphery to the central of subseafloor deposits, and (3) multistage of subseafloor ore-forming activities. Additionally, we characterized the seafloor alteration of Taiji-2 subseafloor sulfides. These results enhance our understanding of subseafloor mineralization in seafloor hydrothermal field. [ABSTRACT FROM AUTHOR]

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Correlation of the scientific approach to the archaeological investigation and vice versa is considered, for at least the past 30 years, as the best strategy to answer questions in cultural heritage. Many archaeological queries have merged archaeological and scientific studies and have been carried out with a multidisciplinary approach that uses complementary analytical techniques. Here, we focused our efforts on outlining the strong relevance of elemental composition in chemistry and mineralogical investigations to answer important archaeological questions in the case of Apulian red figure pottery. This ceramic class is the most important quantitative handcraft production group of figured pottery in Magna Grecia and the most widespread and commercialized production from the third quarter of the fifth century to the end of the next century. The results obtained indicate that, by exploring chemical elements in the ceramic mixture, it is possible to extract information about provenance, manufacturing processes, originality and restoration techniques. [ABSTRACT FROM AUTHOR]

The ExoMars rover, scheduled to be launched in 2020, will be equipped with a novel and diverse payload. It will also include a drill to collect subsurface samples (from 0‐ to 2‐m depth) and deliver them to the rover analytical laboratory, where it will be possible to perform combined science between instruments. For the first time, the exact same sample target areas will be investigated using complementary analytical methods—infrared spectrometry, Raman spectrometry, and laser desorption mass spectrometry—to establish mineralogical and organic chemistry composition. Fundamental for implementing this cooperative science strategy is the Raman Laser Spectrometer (RLS) calibration target (CT). The RLS CT features a polyethylene terephthalate disk used for RLS calibration and verification of the instrument during the mission. In addition, special patterns have been recorded on the RLS CT disk that the other instruments can detect and employ to determine their relative position. In this manner, the RLS CT ensures the spatial correlation between the three analytical laboratory instruments: MicrOmega, RLS, and MOMA. The RLS CT has been subjected to a series of tests to qualify it for space utilization and to characterize its behavior during the mission. The results from the joint work performed by the RLS and MicrOmega instrument teams confirm the feasibility of the "combined science" approach envisioned for ExoMars rover operations, whose science return is optimized when complementing the RLS and MicrOmega joint analysis with the autonomous RLS operation. [ABSTRACT FROM AUTHOR]

Çayırbağı magnesite is one of numerous magnesite deposits occurring throughout Turkey. In this deposit, sepiolite and newly found stevensite occur locally as two daughter minerals formed from magnesite. The sepiolite and stevensite show distinctive compositions and modes of formation compared to those described in the literature. The objective of the current study was to characterize these minerals by means of mineralogic, thermal, structural, geochemical, and textural analyses and to describe their mechanisms of formation. The geology, mineralogy, and geochemistry were examined by field work followed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential thermal (DTA), and thermogravimetric (TG) analyses. Chemical analyses were performed by means of electron microprobe (EMPA), inductively coupled plasma-optical emission spectrometry (ICP-OES), and laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS). The XRD analyses showed that the d110 of the sepiolite was at 12.64 Å and at 13 Å after air-drying and ethylene-glycol solvation, respectively. Identification of the sepiolite as sepiolite-13 Å was supported by FTIR and TG-DTA data. Chemical analyses showed an ideal composition with a structural formula of (Ca0.05K0.02)(Mg7.79Al0.10□0.11)Si12O30(OH)4. Stevensite displayed distinctive results for XRD, FTIR, and thermal characteristics. The structural formula of stevensite was: (Ca0.01Na0.20K0.04)(Mg1.90Al0.30Fe3+0.37Ti0.01□0.43)(Si3.93Al0.07)O10(OH)2, indicating a layer charge arising mainly from octahedral sheets. Field and SEM observations demonstrated that sepiolite was formed from magnesite by transformation via a dissolution–precipitation mechanism. Descending surface waters were responsible for this transformation. Thick magnesite veins were partly replaced whereas in thin veins sepiolite replaced the overall mass. Both surface waters with high Si, low Al and Fe activities, and pH values of 8–9.5 were responsible for sepiolite formation. Stevensite was formed similarly to sepiolite with respect to the mechanism and parent mineral under permanent groundwater; where both Si, Fe, Al activities and pH (>9.5) were high. [ABSTRACT FROM AUTHOR]

The purpose of this study was to carry out a mineralogical, chemical, petrographic and physical-mechanical characterization of the two kinds of slate rocks from Tchihingue deposit in Angola in order to make a good use of them as industrial rocks. The characterization was carried out using Atomic Absorption Spectrometry, thin section petrographic analysis and X-ray diffraction. Determining physical-mechanical properties of the rock was carried out through the abrasion test, and resistance to flexion and compression. It was determined that slates have a majority chemical composition of silicon, aluminum, iron and potassium oxides. Both types have a very fine texture on a sericite matrix, which classifies them as sericitic slates. They are essentially composed of muscovite and quartz. Kaolinite is identified on the yellow slate and hematite on the brown slate as accessory minerals, distinctive features of each slate. Brown slate is richer in micaceous minerals and yellow slate has higher quartz content. The technological properties of these slates are suitable for application as an industrial rock, with little significant difference in flexural strength. The selection of its potential can be given from the aesthetic point of view. [ABSTRACT FROM AUTHOR]

A low-cost adsorbent (wheat plant ash) has been prepared using a common agricultural waste (wheat straw) and its physicochemical characteristics, including chemical, physical, mineralogical, and morphological, and adsorption efficacy are investigated. WPA is characterized by SEM (scanning electron microscopy), CHNS(ultimate analysis) analysis, Brunauer-Emmett-Tellersurface area technique, and Fourier transform infrared method. The BET surface area of wheat plant ash was found to be 37 m²/g. To evaluate its adsorption capacity, paraquat is chosen as the adsorbate. Batch adsorption is performed by varying adsorbent dosage, initial concentration, and contact time. Experimental data are fitted to both kinetic and isotherm models. Pseudo-first-order and pseudo-second-order kinetic models are applied to experimental data, which indicated that the latter model had the best fit. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models are then applied to the equilibrium data. The adsorption capacity of WPA for paraquat removal, determined using the Langmuir isotherm, is found to be approximately 241.3 mg/m² at 303 K. [ABSTRACT FROM AUTHOR]