Acidic Composition Research Articles

Characteristics of pyroclastic deposits and evolution of Maar Bethok Lamongan Volcano Tiris Probolinggo East Java Indonesia

The Lamongan Volcano Complex has a very different character from the Bromo and Argopuro Volcano groups. Lamongan Volcano has 37 volcanic cones and 27 maars (ranu). This volcano is quarter-old and occupies part of East Java Province. Maar Bethok is composed of lava and intercalation between pyroclastic deposits from phreatomagmatic and magmatic falls that still need to be firmly consolidated. These pyroclastic deposits characterize a strombolian eruption with more lava dome or crater wall material ejected. The rocks that make up the Bethok maar include olivine-pyroxene basalt lava and pyroclastic fall deposits with fragments of olivine basalt and basalt composition. The evolution of the Bethok maar eruption started from magma with an alkaline composition and ended with a more acidic composition. The magmatism of Bethok maar has an island arc calc-alkaline affinity.

Effect of Coca-Cola on the Dissolution of Persimmon-Related Phytobezoar in a Tertiary Care Hospital.

Introduction Bezoars, masses of indigestible foreign bodies formed in the gastrointestinal tract, pose challenges in their management.Phytobezoars are particularly problematic due to their difficult diagnosis and resilience towards treatment. Recently, Coca-Cola has emerged as a potential solution due to its acidic composition and mucolytic properties. However, existing evidence is limited, highlighting the need for comprehensive studies. This research explores the efficacy of Coca-Cola in dissolving persimmon-related phytobezoars, aiming to contribute valuable insights to non-invasive treatment options. Material and methods Conducted as a descriptive case series, this study employed gastric cola lavage using non-probability purposive sampling. Patients aged 18-70 with persimmon-related phytobezoars were included. Two nasogastric tubes were inserted for cola lavage over 12 hours, utilizing three liters of colauntil the disappearance of symptoms. When the bezoar disappeared, it was considered as complete success to the treatment. Results Out of 31 patients, 45.2% were male and 54.8% were female, with a mean age of 56.77 ± 9.01 years. Efficacy was noted in 54.8% of cases. Age less than 50 and no history of diabetes mellitus were associated with higher chances of treatment success (p-value ≤0.05). Conclusion Ingestion of Coca-Cola was highly effective, safe, and reliable for the dissolution of persimmon-related phytobezoars, as the frequency of efficacy was high in our study. Coca-Cola ingestion is a non-invasive and cost-effective mode of phytobezoar dissolution that should be taken as a first-line initial treatment option to attain desired outcomes.

A study of perforation fluids for secondary opening of productive formations at the Bovanenkovo oil and gas condensate field

When leaving the drilling of gas wells at the fields of Western Siberia, various methods and technologies are employed for their development, such as the secondary opening of productive formations. While undertaking the secondary opening, it is essential to maintain the reservoir properties of the bottomhole formation zone. Liquids for perforation work must be employed for this purpose. Simultaneously, it is recommended to use salt-based perforating liquids treated with CMC-700 and sulfacell, on a hydrocarbon basis (diesel fuel and gas condensate) and on acidic compositions with a high permeability recovery coefficient for carrying out perforation work at equilibrium and depression. After conducting laboratory experiments, we have selected perforating liquids with a permeability recovery coefficient of over 96 % and perforating liquids based on acid compositions with a permeability recovery coefficient of over 180 %.

Compositional Analysis of High-TAN Sudanese Crude Oil Using High-Resolution Mass Spectrometry and Study of the Effect of Temperature and Catalyst on Acidic Composition.

Sudanese Fula crude oil, from the western region, is considered highly viscous and acidic and contains high amounts of heteroatoms (N and O) but a low sulfur content. This work presents an original and comprehensive analysis of its molecular composition in addition to an investigation of the effect of temperature and catalyst on the treatment of the acid fraction. The analysis was performed using a high-resolution Fourier transform mass spectrometer and Orbitrap-Elite with different ionization methods. The results reveal that the Fula crude oil contains a high abundance of nitrogen composition homologue classes N[H], NO2[H], and NO[H]. Their hydrocarbon composition includes low to high aromatic hydrocarbons. The number of oxygen classes varies from acids containing monocarboxylic acids of O2 to acids of multiple carboxylic and phenolic group (CxHyO3 to CxHyO15) classes, which indicate a high content of acidic moiety of 0.765%. In addition to oxygen classes, the acidic fraction that is present as a NOx series indicates the presence of carboxylic carbazole acidic fraction. Low-temperature crude oil treatment at 200 °C decreases the intensity of acids. No significant reduction to low masses was observed; however, there was a clear reduction to high masses. At a high temperature of 350 °C, the carboxylic acid intensity increases (O2 classes), and thus, heating crude oil to 350 °C is unfavorable as it increases the amount of monocarboxylic acids, which are primarily responsible for corrosion in refinery units. Predicted TAN values of residual samples show a reduction in TAN of 62% using thermal treatment at 200 °C, whereas there is an increase in TAN of 5% at 350 °C. A great reduction in acidity results from catalytic treatment with a transition metal catalyst of cobalt and iridium complex. A reduction in all acidic oils is observed; however, the greater reduction is found in mono- and dicarboxylic acids. Catalytic treatment is shown to result in an 85% reduction in predicted TAN values.

НЕКОТОРЫЕ ОСОБЕННОСТИ РАСПРЕДЕЛЕНИЯ РЕДКОЗЕМЕЛЬНЫХ ЭЛЕМЕНТОВ В ПОВЕРХНОСТНЫХ ОСАДКАХ ЗАЛИВА ТОНКИН (ЮЖНО-КИТАЙСКОЕ МОРЕ)

The peculiarities of the rare-earth elements distribution in the surface bottom sediments in the Gulf of Tonkin (South China Sea) are considered. According to the results of granulometric analysis, the sediments are mainly represented by pelitic silt, silty pelite, and miktites. The REE contents normalized to the chondrite composition show the absence of cerium anomaly, the presence of negative europium anomaly and significant fractionation of light and heavy REE. The values of indicator ratios La /Yb ), Cr/Th, Th/Co, La/Sc, Th/Sc N N indicate the predominance of rocks of intermediate and acidic composition in the erosion areas, due to which sediments were formed. The values of the Ce/La ratio and Strakhov lithochemical modulus (Fe+Mn)/Ti characterize the surface sediments as typical terrigenous without the admixture of endogenous exhalative material. The Eu/Sm ratio values indicate low permeability of the sediments for upward fluid flows, which is consistent with the measured methane concentrations. The analysis of correlations indicates the dominance of the terrigenous source of REE and a significant role of clay minerals and iron hydroxides in the migration and accumulation of REE.

Significant features of association of hemostasis, electrolytic and acidic alkaline composition parameters using different variants of perioperative infusion therapy

The paper presents that the use of Ringer’s solution in the program of perioperative infusion therapy, compared with the use of an isotonic sterofundin solution, causes statistically significant adverse changes in the parameters of hemostasis, acid-base state and electrolyte composition, with the exception of potassium and sodium, venous blood. Also, the correlation analysis confirmed the relationship of significant adverse changes in the parameters of hemostasis, acid-base state and electrolyte composition of venous blood in patients when using Ringer’s solution in the perioperative infusion therapy program.

Spectral Unmixing for Mapping a Hydrothermal Field in a Volcanic Environment Applied on ASTER, Landsat-8/OLI, and Sentinel-2 MSI Satellite Multispectral Data: The Nisyros (Greece) Case Study

The aim of this study was to propose a methodology that provides a detailed description of the argillic zone of a hydrothermal field, based on satellite multispectral data. More specifically, we developed a method based on spectral unmixing where hydroxyl-bearing alteration is represented by a single endmember (representing clays) and the three (nearly) non-altered primary volcanic lithologies, namely, two types of lava flows (basic and acidic compositions) and the loose materials (alluvial/beach deposits, scree, pyroclastic deposits, etc.), are represented by three endmembers. We also used one endmember representing elemental sulfur that is present in fumarolic vents hosted by active hydrothermal craters. The methodology was applied in the south part of Lakki plain inside the Nisyros volcano caldera (Greece), using Sentinel-2, Landsat-8/OLI, and ASTER satellite multispectral datasets. Specifically, it was applied separately to each one of the three datasets. The spectral unmixing results, combined with the relative geological map, provide quantitative estimations of the primary volcanic and loose material areas affected by alteration. In addition, pixels with high abundance values of hydroxyl-bearing alteration corresponded to mapped areas with strong hydrothermal alteration. The developed methodology is superior to conventional approaches (e.g., alteration spectral index) in terms of its ability to describe the overall pattern of the hydrothermal field. The most accurate results were taken when applied to ASTER or Sentinel-2 MSI data.

Agricultural use and pH correction of anaerobic sewage sludge with acid pH

Agricultural use is the main way of recycling sewage sludge. Besides providing nutrients and organic matter to crops and soils, it is an important alternative for recycling this residue. However, problems during the sewage treatment process may generate sludge batches with an acidic pH. Thus, it is essential to understand the consequences of using such sludge on soils and plants, and to explore ways to overcome this limitation. The objective of this study was to evaluate addition rates of anaerobic sewage sludge (ASS) with acidic compositions on the soil fertility and performance of lettuce plants. Additionally, a methodology for pH correction of ASS with acidic pH is proposed. An agronomic experiment was conducted in a greenhouse using seven addition rates of ASS (0.0, 0.25, 0.5, 1, 2, 4 and 8 g kg−1 in dry basis), treated with an additional step of disinfection (solarization), and applied in an Albaqualf soil cultivated with lettuce (Lactuca sativa). Soil and leaf chemical composition, as well as chlorophyll index and the dry matter of lettuce leaves were evaluated. Failures during the acidogenesis phase of the anaerobic digestion process were probably the cause of ASS acidification. Although this ASS increased soil fertility indicators and plant dry matter, it significantly reduced soil pH, thereby requiring a complementary assay to correct its pH up to 6.0, which was achieved through liming. Anaerobic sewage sludges with an acidic pH can be effectively used in agriculture after being dried and disinfected through solarization, followed by pH correction, avoiding negative impacts on soil chemical attributes and plant response.

The Effect of Acidic Water Composition on Removal Efficiency of Air Ammonia in a Spray Tower

Introduction: One of the major factors that affect the employees' health and productivity in industries is the air quality of work environments. One of these pollutants is ammonia gas, which is very important from an economic and environmental points of view. Therefore, this study aimed to investigate the effect of using acidic water compound on the removal efficiency of air ammonia in a spray tower.
 Materials and Methods: In this study, airflow was provided by variable ventilation and water pressure through a class electropump. The rate of ammonia removal from the air stream was investigated by a spray tower with changes in water pressure, inlet gas density, and number of nozzles. For this purpose, at different inlet densities, different liquid pressures and different nozzles with water washing liquid with 0.01 mM sulfuric acid were used as the washing liquid.
 Results: Increased number of nozzles from one to three had a significant effect on ammonia removal (P-Value = 0.021). Increase of the inlet ammonia gas density from 24.1 to 68 parts per million significantly reduced the efficiency (P-Value = 0.058). Increase of the spray pressure from 9 bar to 12 bar also significantly increased the removal of ammonia gas from the spray tower outlet (P-Value = 0.052).
 Conclusion: Increased number of nozzles, increased spray pressure, and decreased density of the ammonia gas inlet gas will increase removal efficiency.

Studying dispersed and rheological properties of hydrocarbon-containing acid emulsions and their efficiency in removing asphalt-resin-paraffin deposits

Currently, the treatment of the bottomhole formation zone with acidic compositions is one of the most common methods to intensify the oil inflow. The use of various modified acid compositions increases the efficiency of acid treatments on the bottomhole formation zone. Acid compositions, including those containing hydrocarbon solvents, which contribute to more efficient removal of organic colmatants, affect the reaction rate of the reagent with the rock and processing equipment, change the reservoir properties, etc.The article presents the results of experimental studies, which are aimed at establishing the effect of the composition of hydrocarbon-containing acidic emulsions consisting of an aqueous solution of hydrochloric acid, toluene and Neonol AF 9-10 on their dispersed and rheological properties, as well as their efficiency in removing paraffin deposits.

Material composition of the kursov’s assise of the vendian period of the Mirnin outshot of the Nepsk-Botuobinsk anteclise according to the results of the core material study

In this work, the object studied is the terrigenous and carbonate rocks of the Kursov’s assise of the Nepsk horizon of the Botuobinsk facies zone of the Mirnin outshot of the north-eastern part of the Nepsk-Botuobinsk anteclise. In recent years, in the course of active geological exploration work in the region, high quality core material appeared. This material was studied at the macro and micro levels, which made it possible to obtain new data on the material composition. Based on the detailed lithological description and petrographic core study, for the first time, the author gives a description and justification of the division of the Kursov’s assise into three lithological packs: low clay sand, middle carbonate clay and high carbonate clay sand. The lithological properties of the studied section reflect the characteristics of the Vendian deposition of sediments in the south of the Siberian paleocontinent. The accumulation of sandstones of the Kursov’s assise was facilitated by the weathering of magmatic rock of acidic and medium composition; the destruction products that came from the north-western part to the south-eastern part of the NepskBotuobinsk anteclise in the modern plan. In the upper-section of the Kursov’s assise, the gradual increase in the maturity of terrigenous rocks, which is associated with the duration of their transportation and repeated redeposition, is observed. The carbonate microbial formations of the middle pack of the Kursov’s assise are the first witnesses to life in the Vendian paleobasin. Their characteristic feature is the magnesia impurity.

Sandstone petrography and provenance of the Chubut Group (Cretaceous) in the Cañadón Matasiete (Golfo San Jorge Basin, central Patagonia): Implications for basin evolution and alluvial organization

Sandstone petrographic data have been used to investigate the provenance of the Matasiete, Pozo D-129, and Castillo formations (Chubut Group) in the Cañadón Matasiete, San Bernardo Fold Belt at Golfo San Jorge Basin, Argentina. Available petrographical data provides evidence of several distinctive volcanic source areas, with minor contributions of metamorphic, plutonic, or sedimentary components. Paleo-volcanic contributions from basic-intermediate (lathwork and microlithic textures) and acidic compositions (felsitic, seriate, granular, and vitric textures) were mainly derived from the Middle-Upper Jurassic rocks of the Lonco Trapial Formation. Pyroclastic components (glass shards, pumice fragments, and eutaxitic textures) derived from coeval volcanic activity in the Andes Cordillera, generated either gradual or abrupt changes in the source of the lithic fragments along the study succession. The observed trends in detrital lithic provenance can be integrated with previous sedimentological and architectural studies of the Matasiete and Castillo formations, revealing that narrow-sheet geometries of the channel fill characterize stratigraphic intervals dominated by pyroclastic components, whereas stratigraphic intervals that contain a low content of pyroclastic materials in the channel fill show ribbon-shaped geometries. Sandstone petrography in volcaniclastic basins can be used to complement other indicators of the evolution of the fluvial systems, providing reliable information about the nature of the changes in the sediment supply within the drainage catchment.

Partial melting, fractional crystallisation, liquid immiscibility and hydrothermal mobilisation – A ‘recipe’ for the formation of economic A-type granite-hosted HFSE deposits

A number of A-type granites host resources of the high field strength elements (HFSE), including the rare earth elements (REE), that have been considered for economic exploitation. The best known of them is the Strange Lake pluton (Canada) with a resource of 20 Mt grading 1.44 wt% REE2O3, of which ~50% are heavy rare-earth oxides. In this paper, we examine the various processes that are likely to be responsible for the hyper-enrichment of the HFSE, starting with the generation of a parental magma through a very low degree of partial melting of a mantle plume or a metasomatically enriched mantle, in both cases, below a continental crust (continental rift). We trace the evolution of this magma (olivine nephelinite) through fractional crystallisation of olivine and clinopyroxene followed by plagioclase, K-rich alkali feldspar and arfvedsonite to the final residues of hyper-enriched HFSE granitic pegmatites. In so doing, we show that at least two additional steps are essential to the process of HFSE enrichment. The first of these is the abrupt termination of plagioclase crystallisation prior to the final consumption of Ca or assimilation of a Ca source and the resulting exsolution of an immiscible Ca-fluoride melt that sequesters the LREE and Y. The second of these steps is prolonged crystallisation of arfvedsonite, which delays saturation of the magma with an aqueous phase and ensures the development of an agpaitic assemblage of Na-bearing HFSE minerals (e.g., Na-zirconosilicates and Na-titanosilicates). Finally, we show that saturation of the magma with an aqueous‑carbonic fluid, which evolves to a very acidic composition, is an essential ingredient in the ‘recipe’ for the formation of an economic A-type granite-hosted HFSE deposit.

Fluid inclusion and stable isotope study of the Lubin-Zardeh epithermal Cu-Au deposit in Zanjan Province, NW Iran: Implications for ore genesis

The Lubin-Zardeh deposit is located in the Western Alborz Magmatic belt, 45 km NE of Zanjan, Iran. This deposit contains polymetallic (Cu, Au, Pb, Zn) mineralization which is hosted by the Cenozoic volcanic-intrusive rocks of mainly intermediate and acidic composition. Pyrite, chalcopyrite, galena, sphalerite, bornite and tennantite-tetrahedrite, with native gold and silver are present in the ores. Quartz, adularia and clay minerals (illite-montmorillonite) with minor calcite are the most abundant gangue minerals and generally occur as fine-grained assemblages; some are, however, medium- and coarse-grained assemblages. The ore minerals show disseminated, vein-veinlet, replacement, and brecciated textures while the gangue minerals represent replacement, cockade, crustiform, colloform, comb, vein-veinlet and plumose textures. Alteration haloes along the main vein are silicic, argillic (illite-montmorillonite), sericitic and pyritic. Gold contents of the quartz-chalcopyrite-gold veins range from 0.002 to 10 ppm with an average of 0.52 ppm. The average values for total reserve of 0.5 Mt of Lubin-Zardeh deposit has been determined 1.3%, 0.7% and 0.4% for Cu, Pb and Zn, respectively. Most of fluid inclusions in the quartz-gold-sulfide veins consist of two vapor and liquid phases at room temperature. The primary fluid inclusions have a low to intermediate homogenization temperature between 127 and 327 °C and salinity between 4.07 and 13.98 wt% NaCl equivalent. Stable isotope and fluid inclusion studies indicate that mineralization occurred in two stages at Lubin Zardeh deposit i.e. stage I; along which base metal deposited and stage II which is associated with copper and gold mineralization. The δ18Oquartz values from stage I and stage II range from 9.56 to 12.77‰ and from 7.23 to 9.24‰, respectively while their δ34S values of sulfide minerals range from −0.9‰ to +6.2‰ and form −6.6‰ to −1.9‰. The isotopic and microthermometric data indicate that the hydrothermal solution evolved through mixing of magmatic fluids with meteoric waters. Boiling of magmatic fluid and mixing with meteoric waters were the main mechanisms of ore deposition in the Lubin-Zardeh low sulfidation epithermal deposit.

Geochemical features of dike rocks of the Argentine islands and the near area of the antarctic peninsula (Western Antarctica)

The block of the Antarctic Peninsula is part of a magmatic arc formed along the southwestern part of the paleo-Pacific margin of the Gondwana supercontinent. Currently, subduction processes continue only in its northwestern part — in the region of the South Shetland islands, and to the southwest of it — there is a passive segment of the continental margin, within which the Argentine islands are located. Here, subduction was completed in the late Miocene-Early Pliocene. In the geological structure of the Argentine islands archipelago, the rocks of the Upper Jurassic volcanic group (AP Volcanic Group) and intrusive batholiths of the batholiths (AP batholiths) are distinguished. In them, there are numerous dikes of basic, medium and acidic compositions. The activation of dyke magmatism on the passive margin of the Antarctic Peninsula was probably connected with subduction processes in its northwestern part.The age sequence of dike formation in the rocks of the Antarctic Peninsula (AP) volcanic Group and intrusions of the gabbroids and granitoids of the Andean complex in the Argentine Islands and the near area of the Antarctic Peninsula is determined. The early dikes of the dacites in the volcanogenic stratum of the AP volcanic Group and the gabbrodiabases in the gabbroids of the Andean complex have a submeridional and northwestern strike. After the introduction of the granitoids of the Andean complex, dikes predominantly of the sublatitudinal and northeasterly strike are formed. The early dikes in the gabbroids of the Andean complex are Fe-Ti cumulates, and in granodiorite intrusions they are represented by aplites, probably formed from the residual magma of these intrusions. Later dikes were formed, probably due to the melting of the metasomatized mantle source at moderate depths under the influence of plumes. To their primitive (initial) melts, the composition of high-magnesian dike rocks is probably close. Products of deep mantle (plume) sources in the sample of selected samples were not detected. The dike rocks of this region according to their geochemical characteristics correspond to the mature island-arc formations of the calc-alkaline series.

Лазуритовая минерализация Бадахшанского массива

Lazurite rocks of the Badakhshan massif, which is located in the south of Central Asia at the junction of two folded structures of the Southwestern Pamir and East Hindu Kush, are considered. On the example of the Sary-Sang, Lyadzhvardara and Goron occurrence, structural-textural features and the mineral composition of the main, secondary and accessory minerals of lazurite rocks are described. The main studies performed are spectral, X-ray structural, chemical analyzes, allowing to reveal their typomorphic features. The formation of lazuritic metasomatites mainly occurs at the regressive stage of metamorphism, which leads to the removal of volatile components (Cl, CO2, S) from evaporite strata with high chemical potential of potassium and sodium and the inert behavior of aluminum and magnesium. The lazurite deposits of the Badakhshan massif have a similar geological structure, but are characterized by a number of mineralogical and geochemical features that affect the scale of the deposits and the quality of lazurite raw materials. Minerals of lazuritic rocks (lapzurite, diopside, phlogopite, clinohumite) often inherit the chemistry of the rocks being replaced, which is reflected in their chemical composition. The concentration of typomorphic impurity elements (Ba, Be, Sr, Ti, Mn, Fe, Zr, Pb) in the minerals of the Lyadzhdara deposit and Horon occurences shows different degrees of metamorphic and metasomatic transformations of the bumi-nised bodies of aluminosilicate rocks. In addition, an important role has a different degree of dislocation and fracturing of rocks. For example, in the Lyadzhvardara field, lazurite mineralization is observed near the nuclear part of the anticline and the isocline that complicates its upturned isocline, and the Sary-Sang deposit linear bodies of lazuritized boudins are traced along tectonically weakened zones. Thus, the main search criteria and signs of zones with lazurite mineralization in the region are:1) confined to the Precambrian complex of magnesian marbles, metamorphosed under the conditions of the amphibolite and granulite facies; 2) the enrichment of marbles with primary sedimentary sulfur; 3) the presence in the marbles of the bodies of aluminosilicate igneous rocks of moderately acidic and acidic compositions, as well as boudinated veins of aplites and pegmatites; 4) the presence of alkaline minerals in the underlying meta-morphic and Boudins of igneous rocks; 5) the nature of fracturing and the intensity of metasomatic processes.

Chemical modifications of Tonda Gentile Trilobata hazelnut and derived processing products under different infrared and hot-air roasting conditions: a combined analytical study.

For the processing industry, it is crucial to know what effect the roasting process and conditions have on hazelnut quality. The present study investigates, for the first time, the effects of hot-air and infrared (IR) roasting at different time-temperature combinations on Tonda Gentile Trilobata hazelnut: whole kernels and derived processing products (paste and oil). The nutritional and physical characteristics of hazelnuts and processing products were investigated to determine the influence of the different roasting conditions as a function of intended use. The antioxidant profile (2.2-diphenyl-1-picrylhydrazyl radical, oxygen radical absorbance capacity and total phenolic content) were analyzed on roasted hazelnut and paste extracts. For a comprehensive understanding of the complex biochemical phenomena occurring during roasting, E-nose and near-IR spectroscopy were also applied. All analytical data were processed using univariate and multivariate data analyses. Hazelnuts derived from IR roasting at higher temperatures (195 °C) showed a richer antioxidant profile and a more intense flavour. On the other hand, the yield associated with the oil extraction under the same conditions was unsatisfactory, making this process completely inadequate for oil production. Oil obtained by hot-air roasting and IR roasting at lower temperature (135 °C) was found to be of good quality, showing rather similar acidity grade, peroxide number and acidic composition. In particular, a slightly but significantly lower acidity was related to lower roasting temperatures (0.21-0.22% versus 0.27% for higher temperatures). All roasting conditions tested allowed the quantitative homogeneous hazelnut paste to be obtained and, from a rheological point of view, a higher roasting temperatures resulted in pastes characterized by higher density and viscosity values. The use of IR was found to be a promising alternative method for hazelnut roasting, as a result of its capability with respect to preserving nutritional values and enhancing organoleptic quality. © 2018 Society of Chemical Industry.

ШВИДКІСНІ ХАРАКТЕРИСТИКИ ЗЕМНОЇ КОРИ КОРОСТЕНСЬКОГО ПЛУТОНУ (УКРАЇНСЬКИЙ ЩИТ) ЗА ДАНИМИ МЕТОДУ ГЛИБИННОГО СЕЙСМІЧНОГО ЗОНДУВАННЯ

A detailed comparative analysis of the velocity characteristics of the Earth's crust of the Korosten pluton, Volyn and Chopovitsky massifs of the basic rocks of the Volyn megablock of the Ukrainian Shield was carried out. In the interval of depths of 3–13 km in the Earth's crust of the Korosten pluton, five sections are fixed, where the speed on a short interval first decreases with depth, then, on the contrary, increases. This is due to the presence in the section of a series of layers composed of rocks with reduced or elevated speeds, which alternate with increasing depth. Such changes in velocity are considered to be the results of alternation of rocks of the basic and acidic composition. With depth, the rate of increase in velocity (vertical velocity gradient), which characterizes the features of rooting into the crust of an intrusion with increased basicity, significantly decreases. These features lie in the fact that the molten masses coming from the upper mantle were concentrated mainly in the upper and middle parts of the Earth's crust. The distinction between the features of the speed characteristics of the Earth's crust of the Volynsky and Chopovitsky massifs of the main rocks is revealed. The velocity characteristics of the compared structures reflect the characteristics of the rooting of igneous melts of the basic composition into the Earth's crust. Despite the territorial proximity of the massifs, the nature of the rooting of the melts between them is significantly different. For example, abrupt changes in velocity in the depth interval of 0–12 km of the Volynsky massif can be attributed to the presence of, at least, 10 layers of rocks, predominantly of acidic and basic composition, which alternate each other. It should be emphasized that at depths of 8–12 km maximum speeds (up to 0.17–0.18 km/s) between individual layers are observed. In the same depth interval in the Chopovitsky massif, only 5 layers stand out with a maximum differential velocity of 0.18 km/s.

Comparison of four glycosyl residue composition methods for effectiveness in detecting sugars from cell walls of dicot and grass tissues

BackgroundThe effective use of plant biomass for biofuel and bioproduct production requires a comprehensive glycosyl residue composition analysis to understand the different cell wall polysaccharides present in the different biomass sources. Here we compared four methods side-by-side for their ability to measure the neutral and acidic sugar composition of cell walls from herbaceous, grass, and woody model plants and bioenergy feedstocks.ResultsArabidopsis, Populus, rice, and switchgrass leaf cell walls, as well as cell walls from Populus wood, rice stems, and switchgrass tillers, were analyzed by (1) gas chromatography–mass spectrometry (GC–MS) of alditol acetates combined with a total uronic acid assay; (2) carbodiimide reduction of uronic acids followed by GC–MS of alditol acetates; (3) GC–MS of trimethylsilyl (TMS) derivatives; and (4) high-pressure, anion-exchange chromatography (HPAEC). All four methods gave comparable abundance ranking of the seven neutral sugars, and three of the methods were able to quantify unique acidic sugars. The TMS, HPAEC, and carbodiimide methods provided comparable quantitative results for the specific neutral and acidic sugar content of the biomass, with the TMS method providing slightly greater yield of specific acidic sugars and high total sugar yields. The alditol acetate method, while providing comparable information on the major neutral sugars, did not provide the requisite quantitative information on the specific acidic sugars in plant biomass. Thus, the alditol acetate method is the least informative of the four methods.ConclusionsThis work provides a side-by-side comparison of the efficacy of four different established glycosyl residue composition analysis methods in the analysis of the glycosyl residue composition of cell walls from both dicot (Arabidopsis and Populus) and grass (rice and switchgrass) species. Both primary wall-enriched leaf tissues and secondary wall-enriched wood/stem tissues were analyzed for mol% and mass yield of the non-cellulosic sugars. The TMS, HPAEC, and carbodiimide methods were shown to provide comparable quantitative data on the nine neutral and acidic sugars present in all plant cell walls.

Relationship Between Sulfide Capacity and Structure of MnO-SiO2-Al2O3-Ce2O3 System

Sulfide capacity of the MnO-SiO2-Al2O3-Ce2O3 system was measured at 1873 K (1600 °C), and the structural analysis was carried out using micro-Raman spectroscopy to understand the role of Ce2O3 in the sulfur dissolution behavior. Sulfide capacity of the basic melts (MnO/SiO2 = 2.2(±0.14)) decreased with increasing content of Ce2O3 to approx. 4 mol pct, beyond which it increased. Sulfide capacity continuously decreased in the less basic system (MnO/SiO2 = 1.0(±0.15)), whereas it was hardly affected by Ce2O3 in the relatively acidic composition (MnO/SiO2 = 0.3(±0.05)). There was a significant increase in the intensity of Raman band at 600 cm−1 by Ce2O3 addition in high MnO/SiO2 (=2.2) system, which originated from the transition from [(Al,Mn0.5)O4]-tetrahedron to [(Al,Ce)O6]-octahedron due to strong attraction between Al2O3 and Ce2O3. Combining thermodynamic and structural information, the effect of Ce2O3 on the sulfide capacity of Mn-aluminosilicate melts can be explained by the following factors: (1) Activity of MnO in the melts decreased by addition of Ce2O3; (2) Free oxygen was consumed in the structure modification from [(Al,Mn0.5)O4] to [(Al,Ce)O6] unit by addition of Ce2O3; and 3) When the Ce3+ content was greater than critical value (approx. 4 mol pct) in high MnO/SiO2 (=2.54) melts, excess Ce3+ and Mn2+ ions competitively reacted with S2− ions, resulting in an increase of sulfide capacity.