Mineral Composition Research Articles

Influence of fermentation conditions, and the blends of sorghum and carrot pulp supplementation on the nutritional and sensory quality of tef injera

Tef [Eragrostis tef (Zucc.) Trotter], an ancient cereal primarily grown in Ethiopia, is becoming increasingly popular worldwide due to its high iron content and gluten-free nature. However, it has been reported that injera produced only with tef flour lack certain vital nutrients. Therefore, this specific study was conducted to supplement tef injera with other food materials of better nutritional value and compensate its expensive market price with sorghum cereal flour. The effect of fermentation conditions, and the sorghum and carrot pulp blending ratio on the nutritional value and sensory quality of tef injera was investigated. The factorial approach of the experimental design was conducted considering the nutritional value and sensory quality of the injera made of three main blending ratios of tef, sorghum, and carrot (60% tef: 30% sorghum: 10% carrot pulp, 45% tef: 45% sorghum: 10% carrot pulp and 30% tef: 60% sorghum: 10% carrot pulp) as experiential variables. The raw materials and injera were characterised for their proximate composition, physicochemical property, mineral composition, microbial analysis, and sensory attributes, using standard methods. The results of the study show that fermentation conditions and blending ratios have a significant effect on the nutritional, anti-nutritional, mineral content, microbial quality, and sensory properties of blended injera products, where higher values of ash, crude protein, crude fat, Total titratable acidity (TTA), Fe, Zn, and Ca (2.30%, 11.34%, 2.62%, 3.53, 32.97 mg/100 g, 2.98 mg/100 g and 176.85 mg/100 g, respectively) were analyzed for the co-fermented injera sample. In addition, a lower microbial count was observed in co-fermented injera samples, whereas microbial counts in injera samples prepared from carrot pulp-supplemented dough after the co-fermentation of tef and sorghum flours were observed to be higher. The injera product made using blending ratio of 60% tef: 30%sorghum: 10% carrot co-fermented was found to be the optimum result due to its very good nutritional improvement (i.e., reduction of some anti-nutritional factors, microbial contents, pH and increased contents of some minerals, crude protein, crude fat, TTA and improved most of the sensory quality of the supplemented injera product). According to this study, sorghum and carrot supplementation on tef could improve the nutritional value of injera while also providing an instant remedy for the growing price of tef.

Thermal spalling failure mechanism of heterogeneous granite under moving heat source

The conventional mechanical methods employed for rock breaking encounter substantial challenges in deep, hard formation drilling, characterized by low penetration rates and exorbitant drilling costs. Consequently, there exists an urgent necessity to explore novel drilling methods and technologies. Thermal spallation drilling, as a non-contact rock breaking technique, offers high efficiency in rock fragmentation and substantially reduces drilling costs. However, the mechanism underlying rock fragmentation induced by thermal spallation remains unclear. Therefore, this study establishes a thermo-mechanical coupling model based on heterogeneous granite subjected to a high-temperature moving heat source. The model comprehensively considers the geometric shape, contact, and strength heterogeneity of rock minerals, and analyzes the effects of heating source speed, radius, mineral composition, heterogeneity index, and grain size on the thermal spallation mechanism of rock. The research findings indicate that lower heating source speeds and larger radii result in higher surface temperatures and greater damage volumes, whereas increasing speed and reducing radius enhance fragmentation efficiency, with speed exerting a more significant influence. Thermal spallation primarily results in tensile damage to rocks, with the surface damage and depth of damage being respectively influenced by the heating source speed and radius. Particle size exhibits minimal impact on thermal spallation, while increased quartz content enhances the rock's thermal properties, resulting in significant thermal spallation effects. Additionally, the location of rock damage is closely correlated with thermal parameters. These findings significantly contribute to a better understanding of the thermal spallation fracture mechanism in granite and facilitate the development of technical solutions for thermal spallation drilling methods.

Quantifying the Pore Heterogeneity of Alkaline Lake Shale during Hydrous Pyrolysis by Using the Multifractal Method

Distinguishing itself from marine shale formations, alkaline lake shale, as a significant hydrocarbon source rock and petroleum reservoir, exhibits distinct multifractal characteristics and evolutionary patterns. This study employs a combination of hydrous pyrolysis experimentation, nitrogen adsorption analysis, and multifractal theory to investigate the factors influencing pore heterogeneity and multifractal dimension during the maturation process of shale with abundant rich alkaline minerals. Utilizing partial least squares (PLS) analysis, a comparative examination is conducted, elucidating the disparate influence of mineralogical composition on their respective multifractal dimensions. The findings reveal a dynamic evolution of pore characteristics throughout the maturation process of alkaline lake shale, delineated into three distinct stages. Initially, in Stage 1 (200 °C to 300 °C), both ΔD and H demonstrate an incremental trend, rising from 1.2699 to 1.3 and from 0.8615 to 0.8636, respectively. Subsequently, in Stages 2 and 3, fluctuations are observed in the values of ΔD and D, while the H value undergoes a pronounced decline to 0.85. Additionally, the parameter D1 exhibits a diminishing trajectory across all stages, decreasing from 0.859 to 0.829, indicative of evolving pore structure characteristics throughout the maturation process. The distinct alkaline environment and mineral composition of alkaline lake shale engender disparate diagenetic effects during its maturation process compared with other shale varieties. Consequently, this disparity results in contrasting evolutionary trajectories in pore heterogeneity and multifractal characteristics. Specifically, multifractal characteristics of alkaline lake shale are primarily influenced by quartz, potassium feldspar, clay minerals, and alkaline minerals.

Research on the generation and annotation method of thin section images of tight oil reservoir based on deep learning

The cast thin sections of tight oil reservoirs contain important parameters such as rock mineral composition and content, porosity, permeability and stratigraphic characteristics, which are of great significance for reservoir evaluation. The use of deep learning technology for intelligent identification of thin section images is a development trend of mineral identification. However, the difficulty of making cast thin sections, the complexity of the making process and the high cost of thin section annotation have led to a lack of cast thin section images, which cannot meet the training requirements of deep learning image recognition models. In order to increase the sample size and improve the training effect of deep learning model, we proposed a generation and annotation method of thin section images of tight oil reservoir based on deep learning, by taking Fuyu reservoir in Sanzhao Sag as the target area. Firstly, the Augmentor strategy space was used to preliminarily augment the original images while preserving the original image features to meet the requirements of the model. Secondly, the category attention mechanism was added to the original StyleGAN network to avoid the influence of the uneven number of components in thin sections on the quality of the generated images. Then, the SALM annotation module was designed to achieve semi-automatic annotation of the generated images. Finally, experiments on image sharpness, distortion, standard accuracy and annotation efficiency were designed to verify the advantages of the method in image quality and annotation efficiency.

Effects of Genotype, Nitrogen, and Sulfur Complex Fertilization on the Nutritional and Technological Characteristics of Buckwheat Flour.

The present study investigated the effect of nitrogen fertilization (NF) at the levels of 0, 45, and 90 kg·ha-1 combined with selected sulfur complex fertilization (SCF) levels of 0 and 45 kg·ha-1 on the nutritional and technological characteristics of buckwheat flour from five varieties. The results showed that the genotype was a critical factor affecting the chemical composition and physicochemical properties of buckwheat flour. NF significantly increased protein, total starch, and amylose content as well as mineral composition but decreased particle size, color value, and water hydration properties. However, SCF enhanced the ash content and decreased the protein content but had no significant effect on the pasting temperature. In addition, the combination of NF and SCF significantly reduced granule size, water solubility, viscosity, and rheological properties with increasing fertilization levels. This study can guide the cultivation of buckwheat with the desired physicochemical properties and provide information for buckwheat-based products in the food industry.

The geological origins and soil properties of loess-like silty clay: a case study in the jinan area

This study, using Jinan as a case study, systematically investigates the characteristics and geological genesis of loess-like silty clay in the middle and lower reaches of the Yellow River. The primary distribution of loess-like silty clay is revealed through field surveys, laboratory experiments, and previous literature reviews. The chemical and physical properties of the loess-like silty clay were examined, in addition to investigations into its mineral composition, microstructural characteristics, and engineering mechanical properties, in order to enhance comprehension of its attributes and formation mechanisms. The research suggests that the distinctive soil environment in the area has been influenced by numerous instances of the Yellow River overflow and channel shifts over its history, as well as the impacts of climate change, geological factors, and human activities. The primary sources of material for the loess-like silty clay consist of loess, Hipparion Red Clay, and paleosol layers. The discussion also addresses the impact of regional climate on the formation of mineral components. The aforementioned findings hold significant implications for advancing the understanding of historical climatic and paleogeographic shifts, as well as for addressing engineering challenges associated with the distribution of loess-like silty clay.

Influence of Mulberry Leaf Powder Additive on Chemical and Physical Characteristics of Wheat and Rice Flour Butter Cookies.

People of all age groups consume cookies every day. Consumers' preferences for cookies supplemented with functional plant raw materials have recently increased. Therefore, this research aimed to investigate the influence of a mulberry leaf additive on the proximate and mineral compositions, total phenolic and total chlorophyll content, antioxidant activity, and the hardness and color properties of butter cookies. Wheat and rice flour butter cookies were prepared by replacing the flour with mulberry leaf powder at 0, 4, 8, and 12% (w/w). The results revealed that the investigated chemical and physical characteristics of butter cookies depend on the flour used (rice or wheat) and the addition of mulberry leaf powder. Wheat and rice flour cookies with 12% mulberry leaf powder had the significantly highest contents of fiber (20.34 and 20.23%, respectively), ash (1.73 and 1.75%, respectively), K (170.22 and 160.22 mg 100 g-1, respectively), and Ca (170.45 and 160.68 mg 100 g-1, respectively). The rice flour cookies enriched with 12% leaf powder had the greatest amounts of total phenolics (1.48 mg 100 g-1), Zn (12.25 mg kg-1), Mn (6.28 mg kg-1), Cu (1.95 mg kg-1), and antioxidant activity (67.98%). However, the wheat cookies without mulberry leaf powder contained the most B (9.12 mg kg-1), while the no-added rice cookies contained the most Fe (14.30 mg kg-1). Replacing flour with leaf powder increased the cookies' hardness and decreased their lightness. In conclusion, enriching butter cookies with freeze-dried mulberry leaves can improve their nutritional value and antioxidant activity.

Intrinsic mechanisms of shale hydration-induced structural changes

The interaction between a water-based working fluid and shale causes a change in shale structure, resulting in wellbore instability and greatly increasing drilling costs. On the basis of the black rock samples of the Longmaxi Formation, the structural change characteristics and internal mechanisms of shale hydration are investigated using scanning electron microscopy, fixed-point observation experiments, X-ray diffraction experiments, ion analysis, and energy spectroscopy analysis. In this study, the changes in the microscopic elements during the propagation of macroscopic cracks to hydration were studied and the ion exchange of brine and mineral hydration was analyzed. The results indicate that the interaction between water and shale leads to shale fracture along the bedding plane, the expansion of primary fractures, the generation of new fractures, and the occurrence of a high number of dissolution phenomena. The ion exchange cation precipitation of shale and the fluid is dominated by Ca2+, and the anion precipitated is mainly SO42−. Through the energy spectrum analysis of the whole-rock mineral composition changes and shale structural changes, it is believed that shale dissolution is mainly from carbonatite minerals, such as calcite. While the oxidation of pyrite in the aqueous environment provides a large amount of SO42− and H+ and fracture propagation mainly occurs in areas where non quartz inorganic minerals are distributed on the bedding plane. The intrinsic mechanism of shale hydration structural changes is revealed through the structural changes, mineral composition changes, and chemical reactions present during the water–shale interaction, which is significant for ensuring the wellbore stability of drilling.

Innovative antibacterial and antifungal coating films of chitosan/nano zinc oxide/essential oil on grape preservation

The effects of some innovative antibacterial and antifungal coating films of chitosan/nano zinc oxide/essential oil (C-ZNO-EO) on grape preservation for human health were studied during the storage periods on (0, 4, 7, 14, and 16) days. Several evaluation approaches were evaluated such as the bacterial evaluations against the presence of the mesophilic aerobic bacteria. The polyamines evaluation was studied by thin-layer chromatography (TLC) for putrescine and spermidine. Soluble sugars were detected by high-performance liquid chromatography (HPLC) for fructose, glucose, and sucrose. Iron, zinc, and manganese were absorbed by the spectrum spectrophotometer. The antifungal properties have been examined against Botryis cineraa, Aspergillus niger, and Tubingensis. The results reported that the highest mesophilic aerobic bacteria (4.73 Log CFU g−1) was recorded in the control grapes on the 16th day, whereas the lowest level (2.05 Log CFU g−1) was recorded for C-ZNO-EO. The polyamines ranged from 12.18 nmol g−1 FW to 10.1 nmol g−1 FW, and from 21.35 nmol g−1 FW to 16 nmol g−1 FW for putrescine and spermidine during the storage periods, respectively. The grapes treated with C-ZNO-EO achieved the maximum increase in glucose and fructose contents (40.61 and 30.05 μmol/g FW), while grapes treated with chitosan/nano zinc oxide (C-ZNO) achieved the maximum increase in sucrose (0.982 μmol/g FW) compared with chitosan (C) and control treatments at the end of the storage periods, respectively. Using C-NZO-EO treatment had a positive effect on the mineral compositions and the antifungal against Botryis cineraa, Aspergillus niger, and Tubingensis. The innovative antibacterial and antifungal coating film by C-NZO-EO was the best treatment for grape preservation.

Mineral Quantitation of Irish Potato (Solanum tuberusom) Treated with Maca (Lepidium meyenii) During Storage

Irish potato (Solanum tuberusom) has contributed to human diet for thousands of years, first in the Andes of South America and then in the rest of the world. Potato is rich in potassium which reduces the risk of cardiovascular disease. Maca (Lepidium meyenii) contains macamides which are thought to have antioxidant effects. Prolonged storage of Irish potatoes is the stage at which good quality tubers are most difficult to maintain because of the transformations occurring at that time lead to quantitative changes in the composition of tubers. This work was designed to quantify potassium along aside with some minerals in Irish potato during storage with aqueous solution of maca flour. In the storage process, potatoes are affected by two negative factors, i.e., high (room) temperature, light and physiological activities in the tuber. The values obtained for Irish potato treated with aqueous maca 1:10 mL distilled water (MA1) and untreated potato as control (CTRL) respectively are potassium (173.85 and 93.67 mg/100 g), sodium (99.74 and 39.59 mg/100 g), magnesium (14.20 and 12.37 mg/100 g), phosphorus (56.00 and 39.00 mg/100 g), zinc (0.34 and 0.30 mg/100 g), manganese (0.39 and 0.33 mg/100 g) and copper (0.01and 0.01 mg/100 g). MA1 differs significantly (p < 0.05) from CTRL for potassium, sodium and magnesium phosphorus and zinc while there was no significant difference for manganese and copper. These results indicate that treating potato with low concentration of aqueous maca helps to retain minerals composition during storage.

Trade-off between Pore-Throat Structure and Mineral Composition in Modulating the Stability of Soil Organic Carbon.

The preservation of soil organic carbon (OC) is an effective way to decelerate the emission of CO2 emission. However, the coregulation of pore structure and mineral composition in OC stabilization remains elusive. We employed the in situ nondestructive oxidation of OC by low-temperature ashing (LTA) combined with near edge X-ray absorption fine structure (NEXAFS), high-resolution microtomography (μ-CT), field emission electron probe microanalysis (FE-EPMA) with C-free embedding, and novel Cosine similarity measurement to investigate the C retention in different aggregate fractions of contrasting soils. Pore structure and minerals contributed equally (ca. 50%) to OC accumulation in macroaggregates, while chemical protection played a leading role in C retention with 53.4%-59.2% of residual C associated with minerals in microaggregates. Phyllosilicates were discovered to be more prominent than Fe (hydr)oxides in C stabilization. The proportion of phyllosilicates-associated C (52.0%-61.9%) was higher than that bound with Fe (hydr)oxides (45.6%-55.3%) in all aggregate fractions tested. This study disentangled quantitatively for the first time a trade-off between physical and chemical protection of OC varying with aggregate size and the different contributions of minerals to OC preservation. Incorporating pore structure and mineral composition into C modeling would optimize the C models and improve the soil C content prediction.

Mineral and particle-size chemometric classification using handheld near-infrared instruments for soil in Northeast Brazil

The characterization of soil variations crucial for agriculture is challenging due to soil having different mineral composition and particle-size distribution. Traditional methods are costly and time-consuming for large-sized areas. Spectroscopic techniques coupled with chemometrics are alternative ways to overcome these drawbacks. Miniaturized near-infrared (NIR) spectrophotometers provide fast, cost-effective spectra acquisition for assessing soil chemistry and distribution despite challenges like overlapped bands and reduced spectral range. This study presents a pattern recognition strategy to address these limitations, enhancing the use of handheld NIR instruments for soil analysis. The study analyzed 176 soil samples from 15 soil groups in the Northeast region of Brazil. First, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and energy-dispersive X-ray fluorescence spectrometry (EDXRF) were employed to characterize the samples, providing complementary vibrational and elemental information, respectively. Common Dimension Analysis (ComDim) identified links between ATR-FTIR and EDXRF data, aiding soil characterization. The Common Components (CCs) from ComDim were used in Partitioning Around Medoids (PAM) clustering, resulting in five distinct classes based on their mineral composition. These classes showed significant differences in clay and sand contents. With the use of ComDim-PAM, samples were labeled for classification via Partial-least Squares-Discriminant Analysis (PLS-DA) and Support Vector Machine (SVM) using NIR spectra (spectral range: 908–1676 nm) from two handheld instruments (Hand 1 and Hand 2). The SVM models outperformed the PLS-DA models, especially by including variable selection for Hand 1, with test accuracy exceeding 90%. These findings highlight the method's advantages for fast and cost-effective assessment, classification, and soil mapping based on their mineral and particle-size distribution.

Reservoir damage mechanism and “Double protection” drilling fluid of tight sandstone gas reservoir in central SiChuan Basin

It is very important to clarify the reservoir damage characteristics and damage characteristics and damage mechanism of tight sandstone gas reservoirs in Jinhua-Zhongtai mountain area of central SiChuan Basin, and put forward the technical countermeasures of “Double protection” drilling fluid to protect the reservoir and the environment, which is very important for the efficient well construction in this area. Through X-ray diffraction, scanning electron microscopy, casting thin sections and other testing methods, the mineral composition and microstructure characteristics of the block were analyzed, and the potential damage factors of the reservoir were clarified. Based on the sensitivity evaluation, it was revealed that the overall sensitivity damage of the block was weak. The main damage type was salt-sensitive damage, and the critical salinity was 9472.5 mg/L. On the basis of the environmental protection drilling fluid system used in this block, the surfactant which can effectively prevent gas invasion and reduce surface tension is selected, and the “Double protection” drilling fluid system is constructed. Through comprehensive performance test and reservoir protection performance evaluation, the core permeability damage rate of the optimized drilling fluid system is reduced from 88.77 to 18.66%, and the cuttings recovery rate is increased to more than 66%, and the cuttings expansion rate is reduced to less than 3.2%, which can effectively solve the problem of reservoir damage in drilling in Jinhua-Zhongtai mountain block in central Sichuan.

Mineralogy and weathering of REE minerals in the Liuchen granite, Guangxi, southern China: Implications for HREE enrichment in the granite regolith

Regolith-hosted ion-adsorption REE deposits (IARDs) in southern China were derived predominantly from the weathering of granitoids. However, the role of primary REE minerals in the formation of a REE-rich regolith during weathering of the granites has not been fully understood. To investigate the formation process of IARDs, fresh granite samples and regolith samples from different horizons (i.e., fully-, highly-, and semi-weathered horizons) in the Liuchen (LC) super-large IARD of Guangxi Province, southern China were collected and studied the compositions of the REE minerals. Allanite-(Ce), monazite, apatite, and zircon are major primary LREE-bearing minerals in the LC granite, and xenotime-(Y) is the major host of HREEs, including Gd, Dy, Er, Yb and Y (up to 38.68 wt%). Altered anhedral xenotimes are observed recrystallized as a result of the breakdown of apatite. These xenotimes have elevated contents of HREEs compared with their precursors. The sizes of these altered xenotimes are significantly smaller (mostly 0.5–5 μm) compared to the primary xenotimes (>50 μm). The increased surface-to-volume ratio for smaller particle sizes of these altered xenotimes make them more susceptible to weathering during supergene alteration. Except for zircon, the volume of primary REE minerals is reduced in zones of intense weathering (fully- and highly-weathered horizons) in the granite regolith, but relics of xenotime which covered by biofilms on their surfaces were observed in the incipient zones of weathering (e.g., in the semi-weathered horizon). Dissolution that begins at their surfaces from nano-scale was observed in these mineral relics. Microbial solubilization of this previously thought insoluble REE phosphate is likely to control the mobilization REE content, especially Y, in the LC granite regolith. Secondary cerianite-(Ce) and LREE- and HREE-bearing phosphates, mainly rhabdophane and florencite, were identified in the regolith, and this is evidence that HREE minerals such as xenotime-(Y) that were undergoing bio-weathering were an important source of materials for the formation of REE-bearing secondary minerals. This may provide new insights into the formation of so-called “ion-adsorption” REE deposits.

Physico-chemical, technological and radiological characteristics of kaolinized granite from northwestern Serbia

In the ceramic industry, the quality of the final ceramic tile as well as the possibility of its use depends on the quality and characteristics of the starting raw materials. One of the potential raw materials that can be used in the production of ceramic tiles is kaolinized granite, and it is necessary to examine its characteristics. In this research, the kaolinized granite of the Jadar block, northwestern Serbia, from the Beli Majdan surface mine, Jadranska Lešnica, was examined. Chemical analysis, X-ray diffraction analysis (XRD), and differential thermal analysis (DTA) were carried out. Ignition tests of the prepared composites were also conducted at three selected temperatures (1000, 1100, and 1250 °C), where total linear shrinkage and water absorption were determined. The activity concentrations of natural radionuclides and the artificial radionuclide 137Cs were determined using the gamma spectrometry method, and then the radiation risk for the external exposure of workers when working with this raw material was assessed. For the samples with the highest content of 226Ra, radon exhalation measurements were performed with the RAD7 device, and the values of the radon emanation coefficient were determined, as well as the values of alpha dose equivalents, which quantified the potential internal exposure of workers. The results of the chemical analysis showed that the content of Al2O3 in the examined composites ranged from 19.11 to 21.00%, and the content of Fe2O3 from 1.53 to 1.72%. Additionally, the K2O content in the tested composites ranges from 4.01 to 5.46%, which indicates the presence of K-feldspar and muscovite, and the Na2O content from 1.82 to 2.61%. Based on XRD analysis, it was established that the mineral composition of kaolinized granite includes quartz, feldspar, mica, calcite/dolomite, and kaolinite minerals. DTA analysis indicates the occurrence of minor endothermic processes at 488.05 °C and 558.12 °C, as well as an exothermic process at 980.8 °C. The color of the ignition is brick red to dark brown red. A trend of increasing linear shrinkage and decreasing water absorption with increasing ignition temperature was observed with the normal appearance of the samples. The average activity concentration of natural radionuclides are around and below the average values for building materials, expect for 40K. The values for 137Cs are below the values measured in soil. Annual effective doses estimated for external exposure are below 1 mSv y−1, which indicates that there is no increased radiation risk when working with this raw material. The values of the radon mass exhalation rate are in the range of 61–113 mBq kg−1 h−1, and the values of the radon emanation coefficient are 6.3–8.4%. The average value of the alpha dose equivalent is 1mSvy−1, which indicates a potential exposure to radon below 100 Bq m−3. Based on the obtained results, it can be concluded that kaolinized granite is a high-quality and radiologically safe raw material for making ceramic composites in the production of ceramic tiles. It has all the necessary characteristics to partially or completely replace feldspar in ceramic composites.

Elements characteristics and potential environmental risk assessment of jarosite residue and arsenic sulfide residue based on geochemical and mineralogical analysis

The waste slag known as jarosite residue (JR) and arsenic sulfide residue (ASR) were produced following the creation of zinc by hydrometallurgical procedures. The increasing annual zinc mining has led to growing pressure to dispose of the resulting JR and ASR from zinc smelting, making it crucial to assess their environmental impact and feasibility for utilization. The main components, distribution characteristics of elements, and potential environmental risks of zinc smelting wastes are studied through toxicity leaching tests, sequential extraction procedures, and various characterization technologies such as XRF, XRD, and SEM-EDS. The mineral compositions of JR are natrojarosite, franklinite, and gunningite, and zinc mainly adheres to the crevices of the natrojarosite mineral. Meanwhile, the ASR of flocculent structures is composed of orpiment, greenockite, arsenic oxide, and calvertite, and As appears in the form of the S-As-O phase. The Zn, Cu, and Cd in JR were dominated by exchangeable bound (81.53–96.6 %), and the main form of As, Cd, Se, and Tl in ASR was organic matter bound (87.0–99.21 %). The Risk Assessment Code (RAC) method confirmed the risk of Cd, Cu, Zn, and Mo in JR is high, while the risk of Cd, Pb, and Cr in ASR is moderate. Compared to the standard value of “Identification Standard for Toxicity of Hazardous Waste Leaching (GB5085.3-2007)”, the leachate concentrations of Zn in JR as well as Cd and As in ASR were exceeded, suggesting that the JR and ASR were in the type of hazardous waste and posed an environmental risk. The study provides theoretical guidance for the future rational management and effective utilization of hazardous waste.

Ecofriendly solidification of sand using microbially induced calcium phosphate precipitation

This study introduces microbiologically induced calcium phosphate precipitation (MICPP) as a novel and environmentally sustainable method of soil stabilization. Using Limosilactobacillus sp., especially NBRC 14511 and fish bone solution (FBS) extracted from Tuna fish bones, the study was aimed at testing the feasibility of calcium phosphate compounds (CPCs) deposition and sand stabilization. Dynamic changes in pH and calcium ion (Ca2+) concentration during the precipitation experiments affected the precipitation and sequential conversion of dicalcium phosphate dihydrate (DCPD) to hydroxyapatite (HAp), which was confirmed by XRD and SEM analysis. Sand solidification experiments demonstrated improvements in unconfined compressive strength (UCS), especially at higher Urea/Ca2+ ratios. The UCS values obtained were 10.35 MPa at a ratio of 2.0, 3.34 MPa at a ratio of 1.0, and 0.43 MPa at a ratio of 0.5, highlighting the advantages of MICPP over traditional methods. Microstructural analysis further clarified the mineral composition, demonstrating the potential of MICPP in environmentally friendly soil engineering. The study highlights the promise of MICPP for sustainable soil stabilization, offering improved mechanical properties and reducing environmental impact, paving the way for novel geotechnical practices.

Micro-scale study of microcapsule cracking performance based on XFEM and fluid cavity model

Microcapsule self-healing has become popular for microcrack repairing in resin mineral composites, and the cracking performance of microcapsule directly affect their repair efficiency on the matrix material. In this study, the problem of how the volume of microcapsule core affects the cracking performance of microcapsule is addressed. Based on the extended finite element method, the representative volume element (RVE) considering the volume of microcapsule core is established by combining the cohesive zone model and the fluid cavity model. On this basis, a numerical simulation study of the cracking performance of RVE with different volumes of microcapsule core under dynamic loading is conducted to investigate the triggered cracking process of the fully filled and incompletely filled microcapsules besides their cracking behavior, respectively. This study provides a reference for the preparation of microcapsules and the numerical simulation of microcapsule mechanical properties.

Mineral Composition of Blackcurrant (Ribes Nigrum L.) Fruits and Leaves

Background Plants as living systems are characterized by the appropriate degree of accumulation of macro- and microelements, which, acting as factors of the external environment, are basic modulators for synthesizing biologically active substances. Blackcurrant (Ribes nigrum L., Grossulariaceae) is widespread worldwide. Berries, leaves, and buds are medicinal raw materials in folk medicine. The regularity of inorganic elements accumulation in this plant and their impact on the quality of raw materials are topical and need to be studied. Aims This work aimed to study the mineral composition of R. nigrum raw materials collected in Western Ukraine (Ivano-Frankivsk and Ternopil regions) and find the regularity of their accumulation in the plant parts and from the soils. Methods The elemental compositions of R. nigrum fruits and leaves, as well as the soils of the growth places, were studied using the method of atomic emission spectrometry with inductively coupled plasma iCAP 7000 Duo. Results The content of 19 inorganic elements in R. nigrum raw materials was established. Their quantities don’t differ significantly depending on the growth places. All the fruits had high K, Na, Mg, P, and Ca contents, which were slightly lower in leaves. Thus, the fruits contain 590-675 mg/kg of Mg, while in leaves, there are just 98-106 mg/kg. Most of Fe was accumulated in the fruits (73-85 mg/kg). The content of Mn was observed in the leaves (57-64 mg/kg), slightly higher than in the fruits (47-51 mg/kg). The content of heavy metals in the objects was within the permitted limits of European Pharmacopeia. The results testify to the inverse relationship between the content of most elements in the soils and the coefficient of their accumulation in the plant. Conclusion The content of macro- and microelements in R. nigrum fruits and leaves had similar profiles but differed in their quantitates. The regularity of element accumulation in R. nigrum raw materials corresponds to the following profile in accordance with their quantitative content in the raw materials: K> Na> P> Mg> Ca> Si> Fe> Mn> Al> Se> Zn> Cu> Co> I> Pb> Ni> Mo> Sr> Cd. The regularity of their accumulation in the plant parts from the soils was established.

Microscopic Characterization and Fractal Analysis of Pore Systems for Unconventional Reservoirs

The complex pore structure of unconventional oil and gas reservoirs is one of the reasons for the difficulties in resource evaluation and development. Therefore, it is crucial to comprehensively characterize the pore structure, understand reservoir heterogeneity from multiple perspectives, and gain an in-depth understanding of fluid migration and accumulation mechanisms. This review outlines the methods and basic principles for characterizing microporous systems in unconventional reservoirs, summarizes the fractal analysis corresponding to the different methods, sorts out the relationship between the fractals and reservoir macroscopic physical properties (porosity, permeability, etc.) with the reservoir microscopic pore structures (pore structure parameters, pore connectivity, etc.). The research focuses on cutting-edge applications of characterization techniques, such as improved characterization accuracy, calibration of PSD ranges, and identification of different hydrogen compositions in pore systems for dynamic assessment of unconventional reservoirs. Fractal dimension analysis can effectively identify the quality level of the reservoir; complex pore-throat structures reduce permeability and destroy free fluid storage space, and the saturation of removable fluids is negatively correlated with Df. As for the mineral composition, the fractal dimension is positively correlated with quartz, negatively correlated with feldspar, and weakly correlated with clay mineral content. In future qualitative characterization studies, the application and combination of contrast agents, molecular dynamics simulations, artificial intelligence techniques, and 4D imaging techniques can effectively improve the spatial resolution of the images and explore the adsorption/desorption of gases within the pores, and also help to reduce the computational cost of these processes; these could also attempt to link reservoir characterization to research on supercritical carbon dioxide-enhanced integrated shale gas recovery, carbon geological sequestration, and advanced underground hydrogen storage.