STUDY OF CHEMICAL REACTIVITY FOR CO2 MINERALIZATION POTENTIAL IN VOLCANIC ROCK PLUGS FROM THE SERRA GERAL GROUP

Purpose. Environmental safety assessment of Khmelnytskyi region based on a comprehensive analysis of soil chemical composition and acidity for identifying potential environmental risks. Methodology. For soil quality assessment, soil samples were collected and analyzed in accordance with established and approved methods. X-ray fluorescence spectrometry (XRF) was used to determine the chemical content of the soil. The acidity of the soil was determined by measuring the actual acidity in the water extract and the potential acidity in the salt extract. Sampling was carried out on the territory of Derazhnyanska ATC, considering different types of land use. The pollution index (PI) was calculated to assess the level of soil pollution, which compares the actual concentration of chemical elements with the reference values. The spatial variability of chemical element concentrations and acidity indicators was investigated, and appropriate cartographic models of these parameters distribution were created within the study area. Findings. The research of light gray podzolized soils of the Derazhnyanska ATC of Khmelnytskyi region was used to determine the chemical content and acidity of the selected samples. The analysis of the chemical composition of the soil using XRF analysis revealed significant spatial variability in the concentrations of elements, but their content did not exceed the maximum permissible limits. Measurements of the actual acidity in the water extract showed a predominantly neutral or close to neutral reaction of the medium (pH 6.9‒7.9), which is favorable for most crops. However, the determination of potential acidity in the salt extract revealed a wider range of pH values (4.5‒7.2), including samples with an acidic reaction, which may indicate the need for liming of some areas. The calculation of the pollution index showed that most of the studied elements are in the moderate pollution category (1 < PI  3), with the highest values for Ti, V and Pb, indicating potential environmental risks and further monitoring is required. Originality. The first comprehensive assessment of the environmental safety of soils in the Derazhnyanska ATC of Khmelnytskyi region was conducted on the basis of a complex analysis of chemical composition and acidity. A methodology for assessing environmental risk, which takes into account the correlation between the concentration of chemical elements, soil acidity, and environmental safety, was developed and tested. Practical value. The investigation of environmental safety based on the analysis of the chemical composition and acidity of soils in Khmelnytskyi region is important for the sustainable development of the region and environmental protection. The obtained data provide an opportunity to assess the level of anthropogenic pressure on the ecosystem and develop effective measures to improve the ecological state of soils. Identification of areas with high content of pollutants and abnormal acidity allows for targeted environmental protection measures and optimization of agricultural activities, considering environmental risks.

Development of routines for simultaneous in situ chemical composition and stable Si isotope ratio analysis by femtosecond laser ablation inductively coupled plasma mass spectrometry

This study aims to characterize the phase composition and chemistry of the speiss/matte sample from the Metallurgist's Burial at Castillo de Huarmey and to use the information derived from these analyses to infer the temperatures, furnace conditions, and ores associated with the smelting processes, which created the speiss/matte sample. For this purpose, a number of geochemical analyses were performed on the spies/matte fragment: analysis of the general chemical composition (handheld X‐ray fluorescence spectrometry [hhXRF], X‐ray photoelectron spectroscopy [XPS]), analysis of the chemical composition in the micro area (field emission scanning electron microscope with an energy dispersive spectroscopy detector [FE‐SEM‐EDS], field emission electron probe microanalysis [FE‐EPMA]), analysis of the mineral composition (X‐ray diffraction [XRD]), and analysis of the phase composition (Raman spectroscopy). Chemical and mineralogical analyses of the speiss/matte specimen determined that the specimen is composed of distinct arsenide, arsenate, sulfide, and glass phases. During the smelting process, the charge material consisted mainly of Cu, Fe, and As sulfides. Arsenopyrite is the most likely candidate as the mineral source of arsenic. In addition, temperatures of at least 1200°C were achieved during the smelting process, with smelting occurring over a relatively short timeframe given that effective density separation of speiss and matte phases was not achieved.

Carbon dioxide (CO2) geological storage has a large potential to achieve a net-zero target of CO2 emissions. CO2 injected into the storage formation typically becomes a super-critical state under the underground temperature and pressure conditions. The injected super-critical CO2 (scCO2) tends to migrate upwards within the reservoir due to its lower density compared to the formation brine even though the density of scCO2 is quite higher than that of gaseous phase CO2. Moreover, injected CO2 is affected by not only the gravity segregation but also the viscous fingering. These phenomena are expected to cause poor storage efficiency in carbon storage projects. In this study, we investigated the potential of adding common metal oxide nanoparticles to scCO2 to improve the storage efficiency utilizing the properties of scCO2 as a solvent under subsurface conditions. This paper presents the pseudo-fluid modeling of scCO2 containing nanoparticles and the results of numerical simulation considering the effects of nanoparticle types and concentrations on the CO2 storage efficiency. In particular, the effect of density alteration on CO2 storage efficiency was investigated in this study. Some pseudo-fluid models of scCO2 containing four types of nanoparticles, such as aluminum oxide, silicon dioxide, titanium oxide, and zinc oxide with different concentration were created, respectively. Furthermore, numerical simulations of scCO2 injection with and without nanoparticles were performed using a two-dimensional radially symmetric model. The results from this work showed the migration of CO2 to the upper part of the formation was suppressed and the storage of CO2 in the lower part of the formation was promoted when scCO2 was injected with nanoparticles. Furthermore, CO2 breakthrough time was delayed several months or years and total breakthrough quantities were also decreased as the density and concentration of nanoparticles in scCO2 became higher in the case of installing an imaginary production well for pressure control. These results suggest that the injection of nanoparticle-dispersed CO2 improves the storage efficiency of CO2 geological storage compared to the injection of CO2 alone. Furthermore, this study showed that the concept has possibility of improving the safety of CO2 geological storage, which may play an important role when considering the long-term CO2 sequestration as well.

Adding conductive carbon fillers to insulating thermoplastic polymers increases the resulting composite's electrical conductivity. Carbon nanotubes (CNTs) are very effective at increasing composite electrical conductivity at low loading levels without compromising composite tensile and flexural properties. In this study, varying amounts (2–8 wt %) of CNTs were added to polycarbonate (PC) by melt compounding, and the resulting composites were tested for electrical conductivity (1/electrical resistivity), thermal conductivity, and tensile and flexural properties. The percolation threshold was less than 1.4 vol % CNT, likely because of CNTs high aspect ratio (1000). The addition of CNT to PC increased the composite electrical and thermal conductivity and tensile and flexural modulus. The 6 wt % (4.2 vol %) CNT in PC resin had a good combination of properties for electrical conductivity applications. The electrical resistivity and thermal conductivity were 18 Ω‐cm and 0.28 W/m · K, respectively. The tensile modulus, ultimate tensile strength (UTS), and strain at UTS were 2.7 GPa, 56 MPa, and 2.8%, respectively. The flexural modulus, ultimate flexural strength, and strain at ultimate flexural strength were 3.6 GPa, 125 MPa, and 5.5%, respectively. Ductile tensile behavior is noted in pure PC and in samples containing up to 6 wt % CNT. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Carbon Capture and Storage (CCS) is attracting increasing scientific attention. Although experiments can explore the chemical process of CO2 sequestration, they are limited in time. CO2 geological storage will last hundreds and thousands of years, even much longer, so the numerical simulation method is used to conduct kinetic batch modeling and reactive transport modeling. The geochemical simulation tool—TOUGHREACT—is used to imitate CO2-brine–rock interactions at the Shihezi Formation in the Ordos basin. The mechanisms of CO2-brine–rock interaction and their effects on the reservoir are discussed, especially the change in structure and properties. K-feldspar and albite will dissolve as the main primary minerals. However, calcite and quartz will dissolve first and precipitate last. In addition, siderite and ankerite also appear as precipitation minerals. Mineral dissolution and precipitation will alter the formation of petrophysical parameters, such as porosity and permeability, which play significant roles in the geological storage environments. Although the CO2-brine–rock interaction rate may be small, it is an ideal way of geological storage. Regardless of what minerals dissolve and precipitate, they will improve the dissolution of CO2. The interaction between rock and brine with dissolved CO2 can promote the amount of mineralization of CO2, called mineral trapping, which has a positive effect on the long-term feasibility of CO2 storage.

Fabrication Process and Characterization of Conductive Composite for PEFC Bipolar Plates

Besides climate change impacts on water availability and hydrological risks, the consequences on water quality is just beginning to be studied. This research concerns the impacts of climate change on surface water quality through multilevel analysis. Multilevel modeling is a relatively new statistical technique in environmental science research, although its roots can be traced back to several other fields. The objective of this study was to evaluate the surface water quality, its spatial variation and its dependence on climatic parameters. The water quality data for seven parameters, namely Color, Turbidity, pH, Electrical Conductivity, Chloride, Total Alkalinity and Total Hardness collected from 2012 to 2014 from 68 locations around Sri Lanka was used for the analysis. These monthly water quality measurements had been made on two occasions nested within locations within districts and thus had a multilevel structure. Hence a multilevel regression model was adopted using the Bayesian Markov Chain Monte Carlo method. Since, neither of the 95% credible intervals for chemical composition (0.682, 4.945) and physical composition (0.203, 0.485) of water included the value zero, district level variances are significant. The chemical composition of water varies more with the districts compared to the physical composition of water. Several locations in Anuradhapura and Monaragala districts contributed to this significant difference in chemical composition and several locations in Ampara district presented a significant contribution to the difference in the physical composition as shown by the non-inclusion of the value zero in their individual 95% confidence bands. Further, it was observed that rain (P<0.01), temperature (P<0.01) and humidity (P<0.05) have an impact on both the chemical and physical composition of surface water. Source type (P<0.01) has an impact only on physical composition of water. The main conclusion of the study was that drinking water quality varied geographically and over time according to climatic conditions.

Polymer‐based materials with high electrical conductivity are of considerable interest because of their wide range of applications. The construction of a 3D, compactly interconnected graphene network can offer a huge increase in the electrical conductivity of polymer composites. However, it is still a great challenge to achieve desirable 3D architectures in the polymer matrix. Here, highly conductive polymer nanocomposites with 3D compactly interconnected graphene networks are obtained using a self‐assembly process. Polystyrene (PS) and ethylene vinyl acetate (EVA) are used as polymer matrixes. The obtained PS composite film with 4.8 vol% graphene shows a high electrical conductivity of 1083.3 S/m, which is superior to that of the graphene composite prepared by a solvent mixing method. The electrical conductivity of the composites is closely related to the compact contact between graphene sheets in the 3D structures and the high reduction level of graphene sheets. The obtained EVA composite films with the 3D graphene structure not only show high electrical conductivity but also exhibit high flexibility. Importantly, the method to fabricate 3D graphene structures in polymer matrix is facile, green, low‐cost, and scalable, providing a universal route for the rational design and engineering of highly conductive polymer composites.

Adding conductive carbon fillers to thermoplastic polymers increases the resulting composite's electrical conductivity. Carbon black (CB) is very effective at increasing composite electrical conductivity at low loading levels. In this study, varying amounts (2 to 10 wt %) CB were added to polycarbonate (PC) and the resulting composites were tested for electrical conductivity (1/electrical resistivity), thermal conductivity, and tensile and flexural properties. These results were compared with prior work done for carbon nanotubes (CNT) in polycarbonate. The percolation threshold was ∼ 2.3 vol % CB compared to between 0.7 and 1.4 vol % CNT. At 8 wt % filler, the CNT/PC composite had an electrical resistivity of 8 ohm‐cm compared to 122 ohm‐cm for the CB/PC composite. The addition of CB to polycarbonate increased the composite electrical and thermal conductivity and tensile and flexural modulus. The 8 wt % (5.5 vol %) CB in polycarbonate composite had a good combination of properties for semiconductive applications. Ductile tensile behavior is noted in pure polycarbonate and in samples containing up to 8 wt % CB. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

We have developed a new copper-carbon fiber composite which possesses properties of copper, i.e., excellent thermal and electrical conductivities, in combination with a property of carbon fiber, i.e., a small thermal expansion coefficient. The composite properties can be controlled by the amount, type and orientation of the carbon fibers they contain. Therefore, this composite is considered to be useful as an electrical material.The effects of volume and arrangement of fibers on the thermal conductivity, electrical conductivity and specific heat of the composite were studied. The results obtained were as follows:(1) The thermal and electrical conductivities of the composite became smaller as the volume of carbon fibers increased, and they were also influenced by the fiber arrangement.(2) The above conductivities could be calculated by careful application of the “rule of mixtures” for composites.(3) The specific heat of the composite was dependent not on the fiber arrangement but on the fiber volume.(4) In thermal fatigue tests, no degradation in electrical conductivity was observed.

Shear-induced preferential alignment of carbon nanotubes resulted in anisotropic electrical conductivity of polymer composites

Aluminum matrix composites are widely used in many structural application due to properties like high specific strength, wear resistance, lightweight and fatigue properties. The aim of the current work is to investigate the effect of the addition of nanosize participles to AA6063-T4 aluminum alloy on the electrical conductivity, magnetic and fatigue properties of composites produced by stir casting method. It was revealed that the AA6063-T4/ composites were successfully prepared with 3 wt%, 5 wt% and 7 wt% TiO2 using a stir casting technique with electrical conductivity increasing with increasing amount of Also it was found that the electrical conductivity of all composites was higher than the base metal matrix and the conductivity was proportion to the frequency for both matrix and composites. The magnetic studies revealed an improvement of the nanocomposites in comparison with the base metal. The fatigue life and fatigue strength of 7 wt% TiO2 composite was found to be higher than that of other composites and base matrix.

The C-matrix: Augmentation and reduction in the analysis of chemical composition and structure

The aim of this study was to provide a comparative analysis of chemical and fatty acid composition, as well as of the connective tissue proteins in pigs of different genotypes, Mangalitsa and Landrace. Both pig genotypes were fed with the same feed of standard composition and quality. At the end of the fattening period, in total 24 pigs of both genotypes were slaughtered. Based on the analysis of the chemical composition we came to the conclusion that the protein content in both genotypes was similar. Moisture and ash content in the Landrace pig genotype differed significantly (P &lt; 0.01) compared with genotype of Mangalitsa breed. Statistically significant differences (P &lt; 0.01) were established in the fat content, which was 7.95 g/100 g, in pigs of Mangalitsa breed and 1.59 g/100 g in the Landrace pigs breed. Content of hydroxyproline, non-proteinogenic amino acids, in meat of Landrace was significantly higher (P &lt; 0.01) compared to the content in the Mangalitsa breed. The same tendency was observed with regard to the connective tissue protein content, as well as with the relative connective tissue protein content. The fatty acid composition of the meat indicated that the most common saturated fatty acid (SFA) in both tested breeds was palmitic fatty acid (C16), whose content was significantly higher in Landrace (P &lt; 0.01) compared with its content in Mangalitsa breed. In addition, the share of stearic acid (C18) was significantly higher (P &lt; 0.01) in Landrace compared to Mangalitsa pig breed, what significantly contributed to the increase of the SFA share in Landrace compared to Mangalitsa breed. The most common monounsaturated fatty acid in both pig breeds was the oleic fatty acid (C18:1), whose share was significantly higher in Mangalitsa compared to the Landrace breed (P &lt; 0.01). Out of the polyunsaturated fatty acids (PUFA), linoleic fatty acid (C18:2) was the most predominant in both pig breeds, with no statistically significant differences (P &gt; 0.05). The content of PUFA was not statistically significantly different between the tested breeds, as well as the content of n-3 and n-6 fatty acids, which caused no statistically significant differences in the n-6/n-3 PUFA ratio. Ratio of the unsaturated fatty acids, i.e., of the sum of MUFA and PUFA, and of the saturated fatty acids was significantly higher in Mangalitsa compared to Landrace breed (1.86 vs. 1.4), and the same was observed when it comes to the relationship MUFA/SFA (1.51 in Mangalitsa vs. 1.08 in Landrace breed) and MUFA/PUFA (4.35 vs. 3.38).