Search Results (92)

This study investigates near-infrared (NIR)-induced, Phyto-enhanced, second harmonic generation-mediated photodynamic therapy (Phyto-SHG-PDT) using barium titanate (BT)/rhein/polyethylene glycol 100 (PEG100) and BT/Yemenite “Etrog” leaf extract/PEG100 nanoconjugates. We compare continuous-wave (CW), multi-line Argon-ion laser illumination in the NIR range with high-peak-power femtosecond (fs) 800 nm pulses. Under CW NIR light, BT/rhein nanoconjugates reduced PC3 prostate cancer cell viability by 18% versus non-irradiated controls (p < 0.05), while BT/extract nanoconjugates exhibited 15% dark toxicity. The observed SHG signal matched theoretical predictions and previous CW laser studies. Reactive Oxygen Species (ROS) scavenger 1,3-diphenyl-isobenzofuran (DPBF) showed reduced absorbance at 410 nm upon NIR illumination, indirectly supporting SHG emission at 400 nm from nanoconjugates. Under fs-pulsed laser exposure, pronounced two-photon absorption (TPA) and SHG effects were observed in both nanoconjugate types. Our results demonstrate the effectiveness of BT/rhein nanoconjugates under both laser conditions, while the BT/extract nanoconjugates benefited from high-power pulsed excitation. These results highlight the potential of BT-based Phyto-SHG-PDT nanoconjugates for NIR and blue light applications, leveraging nonlinear optical effects for advanced photochemical cancer therapies. Full article

Water injection is widely recognized as one of the most important operational approaches for enhanced oil recovery in oilfields. However, this process faces significant challenges due to the formation of sulfate and carbonate mineral scales caused by high salinity in both injected water and formation water. To address this issue, the use of mineral scale inhibitors has emerged as a valuable solution. In this study, we evaluated the performance of seven machine learning algorithms (Gradient Boosting Machine; k-Nearest Neighbors; Decision Tree; Random Forest; Linear Regression; Neural Network; and Gaussian Process Regression) to predict inhibitor efficiency. The models were trained on a comprehensive dataset of 661 samples (432 for training; 229 for testing) with 66 features including temperature; concentrations of various ions (sodium; calcium, magnesium; barium; strontium; chloride; sulfate; bicarbonate; carbonate, etc.), and inhibitor dosage levels (DTPMP, PPCA, PBTC, EDTMP, BTCA, etc.). The results showed that GPR achieved the highest prediction accuracy with R² = 0.9608, followed by Neural Network (R² = 0.9230) and Random Forest (R² = 0.8822). These findings demonstrate the potential of machine learning approaches for optimizing scale inhibitor performance in oilfield operations Full article

This study evaluated the chemical composition and subcutaneous tissue biocompatibility of C-Point, a root canal filling material, compared to ProTaper gutta-percha cones (control). Material characterization was conducted using scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). For biocompatibility assessment, both materials were implanted subcutaneously in the dorsal connective tissue of sixteen albino rats (n = 8 per group). Histological evaluation of inflammatory infiltrate intensity was performed at 30 and 60 days post-implantation, with statistical analysis (significance set at p < 0.05). SEM-EDS analysis revealed distinct elemental compositions: C-Point primarily contained zirconium and cobalt ions, while gutta-percha cones demonstrated a strong zinc signature with trace amounts of barium, aluminum, and sulfur. Both materials exhibited similar particulate morphology with radiopaque inclusions. Histologically, no significant difference in inflammatory response was observed between C-Point and gutta-percha at any time point (p > 0.05). All specimens developed a fibrous encapsulation. The inflammatory profile showed temporal dynamics, with lymphocyte predominance during early stages that progressively diminished by the study endpoint. These findings demonstrate that while C-Point possesses a unique elemental profile dominated by zirconium, its tissue biocompatibility parallels that of conventional gutta-percha obturation materials. However, due to the absence of mechanical testing and the limited in vivo follow-up period, the long-term stability of the material remains uncertain. Full article

The luminescent properties of cerium-doped barium aluminate (BaAl₂O₄) samples with varying Ce concentrations (0–1.1 mol%) prepared either in an air or nitrogen-reduced atmosphere are presented. This work provides the first detailed comparison of the material’s structural, luminescent, and chromatic properties at different doping levels and thermal treatments. X-ray diffraction analysis confirmed the hexagonal crystal structure of barium aluminate. Samples treated in an air atmosphere exhibited crystallite sizes of 58.5 nm for undoped samples and 45.7 nm for doped samples. In contrast, those treated under nitrogen showed smaller crystallite sizes, i.e., 39.8 nm for undoped and 42.3 nm for doped samples, respectively. XPS analysis indicated that the nitrogen-reduced atmosphere minimized Ce oxidation, favoring the presence of Ce³⁺. The bandgap values of the material were 4.0 eV and 5.6 eV for the air and for the nitrogen atmosphere, respectively. Photoluminescence spectra showed maxima at 357 nm (air) and 386 nm (nitrogen), attributed to 4f-5d transitions of Ce. The samples under air atmosphere showed longer lifetimes values (0.94 ns) compared to those in a nitrogen atmosphere (0.40 ns). These results suggest that thermal treatment in an air atmosphere promoted better structural order and higher photoluminescence efficiency, while treatment in a nitrogen-reduced atmosphere increased defect formation, shortening the lifetime. Chromaticity coordinate analysis showed that the cerium ion dopant influenced the blueish emission color in both samples. Full article

Petroleum is an indispensable energy source in modern industrial society, and maintaining the safe and stable operation of its injection and production system is of great significance. To analyze the mechanism of pipeline damage caused by corrosion and scaling in the injection production system, taking a water injection pipeline in an oil field as an example, the causes of corrosion and scaling damage were studied by detecting pipeline samples and analyzing corrosion products and various service conditions of the pipeline. The results showed that there was more scaling on the inner wall of the pipeline, and there was local corrosion in the pipeline sections that had experienced water injection, shutdown, and gas injection conditions, while there was no significant corrosion thinning in the pipeline sections that had only experienced water injection and shutdown conditions. The scale layer formed under water injection conditions is mainly composed of barium strontium sulfate (Ba_0.75Sr_0.25SO₄), barium sulfate (BaSO₄) and a small amount of silica (SiO₂). The main reason for scale formation is the high content of barium ions (Ba²⁺) in the injected water. The corrosion products formed under gas injection conditions, including strontium ions (Sr²⁺) and sulfate ions (SO₄²⁻), are mainly composed of ferrous carbonate (FeCO₃) and ferric oxide (Fe₂O₃). The pipeline corrosion product FeCO₃ is mainly caused by carbon dioxide (CO₂) in the medium. In addition, the high liquid content, cecal position, high Cl⁻ (chloride ion) content, and slightly acidic environment in the pipeline also accelerate the occurrence of corrosion damage. The Fe₂O₃ in the corrosion products is formed when the pipeline is exposed to air after sampling, and is not the main cause of pipeline corrosion. Full article

Barium slag, classified as HW47 hazardous waste, is produced in large quantities and has a high accumulation with heavy metal Ba ions that are significantly above the standard levels, posing a serious threat to the ecological environment and the growth of flora and fauna. Before barium slag can be stored, it must undergo harmless treatment, which is costly, and with the current large volume of accumulated barium slag, storage facilities are strained. There is an urgent need for new technologies to extract barium elements from barium slag while achieving reduction in volume. This study first treats the barium slag to reduce its oxidation state and then utilizes the density differences to separate barium-rich compounds through shaking table concentration. Macro and microanalytical methods such as XRD (X-ray diffraction), XRF (X-ray fluorescence), and SEM&EDS (Scanning Electron Microscopy & Energy-dispersive X-ray Spectroscopy) were employed. The results show that barium in the slag is evenly distributed, and after sufficient crushing, it can be separated by gravity concentration. The barium content can be enriched from 20% to over 80%. This research provides theoretical support for the separation of barium compounds from barium slag. Full article

A novel efficient barium sulfate scale inhibitor was designed by examining important quantum parameters such as adsorption energy, solubility, steric hindrance parameter, and entanglement molecular weights. Through molecular simulation techniques, it was found that the carboxylic acid group of the scale inhibitor molecule could transfer an average of 0.07 e⁻ electrons to the barium sulfate surface. During molecular dynamics simulations, closer adsorption between oxygen atoms and barium ions in the scale inhibitor was observed, which resulted from van der Waals forces. Based on the simulation results at the molecular level, we successfully prepared this scale inhibitor by free radical polymerization and verified its high efficiency in our experiments: the scale inhibition efficiency was as high as 89.1% when used at a concentration of 160 mg/L under the conditions of pH = 7 and 70 °C. In addition, by SEM and XRD analyses, we further confirmed the consistency of the scale inhibition mechanism of the scale inhibitor with the molecular simulation results. Full article

This paper analyzes the effective use of a mixture of fly ash (MSWI-FA) and solid waste from flue gas treatment (MSWI-SW), which are by-products of the municipal waste incineration process. MSWI-FA (19 01 13*) and MSWI-SW (19 01 07*) are classified as hazardous waste due to their toxic metal content and leaching potential, and currently lack practical applications, unlike slag and bottom ash (19 01 12). This study tested these wastes as partial substitutes for natural sand within a range of 0–20% of cement mass. Statistical analysis of the experimental results allowed the creation of good quality models predicting the effect of substitution additives on compressive strength and flexural strength (correlation 0.91 and 0.93, respectively). The mixture with the highest share of substitution additives (40% = 20% + 20%) was characterized by a decrease in compressive strength by 1.3% and flexural strength by 25.8%. Cement mortars synthesized with the waste mixture (up to 20% of each component) showed slightly lower consistency and water absorption than the control mortars. After the frost resistance tests (25 cycles), the flexural and compressive strength showed ambiguous behavior, showing both increases and decreases, indicating that the percentage of waste components alone is an insufficient set of factors for predicting these strength properties. The concentration of metal ions, i.e., Zn, Cu, Pb, Ni, Cu, and Cr, in the eluate after the leaching tests did not exceed the legal levels of pollutants introduced into waters, with the exception of barium. However, its content did not exceed the permissible levels required for waste intended for landfill. Using the mixing plant for this waste in the amount of 20% each, we save about EUR 10 in the cost of purchasing sand (which is 13% of the production costs of 1 m³) and EUR 8 in the cost of environmental fees when producing 1 m³ of mortar. The proposed technology is compatible with the objectives of a sustainable economy. Full article

This study proposes an innovative method for the harmless treatment of barium slag using the industrial by-product Flue Gas Desulfurization Gypsum. Barium slag is a by-product of the barium carbonate production process, and due to its high content of barium ions and corrosive properties, it poses a significant threat to the environment and human health. It is classified as barium-containing hazardous waste (code HW47) in China. In this study, barium slag was optimally combined with FGD gypsum, utilizing a synergistic precipitation mechanism to solidify the easily leachable barium ions and form stable sulfate minerals. Mechanical and heavy metal leaching tests showed that the harmlessly treated barium slag had a certain compressive strength, and the concentration of barium ions in the leachate was below the national hazardous waste identification standards (100 mg/L) and the drinking water quality standards (0.7 mg/L). Microstructural analysis using X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy indicated that FGD gypsum promotes the solidification of barium slag, and through the synergistic precipitation mechanism, low-solubility barium sulfate minerals are formed. This treatment method also has a low cost and good potential for resource utilization, providing effective technical support for the green treatment of industrial waste. Full article

This study aims to reveal the extent of the impact of mining activities on groundwater in a specific mining area in Hunan Province, assess the current quality of groundwater in the study area, investigate the correlations among heavy metal elements, and understand the migration and enrichment processes of different elements in groundwater. The findings will provide scientific data support for the establishment of groundwater monitoring systems by local governments and environmental protection departments. This paper presents the monitoring work conducted on the current status of heavy metal ions in groundwater within a mining area. Sampling and analysis were performed to measure pH, total dissolved solids (TDS), manganese (Mn), arsenic (As), cobalt (Co), molybdenum (Mo), barium (Ba), antimony (Sb), and selenium (Se) in both groundwater and surface water surrounding the study area. An improved hierarchical ladder evaluation method was used to comprehensively assess the degree of heavy metal pollution in the groundwater of the mining area. Additionally, statistical analysis was conducted to examine the correlations between heavy metal evaluation factors and TDS. The results show that the TDS values at various water quality monitoring points range from 187.34 to 1359.67, with a median of 400 and an average of 460.83. Additionally, the analysis of heavy metal pollution characteristics indicates that the water bodies in the mining area are severely impacted by mining activities, falling into the category of severe pollution. Among the heavy metals, As and Sb are the most serious pollutants, while the other heavy metal evaluation factors are less affected by mining activities. Correlation analysis further reveals that the correlation coefficients between Mo and Se and between Se and TDS are 0.772 and 0.778, respectively, indicating strong correlations. The correlation coefficients between As and Sb, Ba and Sb, and Mo and TDS are 0.455, 0.55, and 0.499, respectively, indicating moderate correlations. Other factor pairs exhibit weak correlations or even negative correlations. Full article

In the framework of luminescent rare-earth-doped glasses for near-infrared applications, TiO₂-containing inorganic glasses have been recently demonstrated to be a promising alternative to commercially used high-phonon SiO₂-based glasses. This study investigates the effect of TiO₂ concentration on the near-infrared spectroscopic properties of Yb³⁺ ions in multicomponent titanate–germanate glasses. A series of glass samples in the xTiO₂-(60−x)GeO₂-BaO-Ga₂O₃-Yb₂O₃ system (x ranging from 0 to 50 mol%) were synthesized using the melt-quenching technique. X-ray diffraction analysis confirmed the fully amorphous nature of the fabricated titanate–germanate samples. Fundamental spectroscopic properties of Yb³⁺-doped titanate–germanate system consisting of absorption spectra, near-IR emission spectra, and luminescence decay curves have been determined based on measurement using optical spectroscopy. The intensity of the emission band at 1 µm due to the ²F_5/2 → ²F_7/2 laser transition of Yb³⁺ ions increases by over 2.3-fold (TiO₂ as the network former) compared to a barium gallo-germanate sample without TiO₂. Our previous studies indicate that Yb³⁺-doped titanate–germanate glass is a promising optical material and could be successfully applied to laser technology. Full article

A simple and innovative method was introduced for the production of green and recoverable flame-retardant cotton fabrics, where sulfonated cotton fabric (COT-SC) was synthesized by oxidizing cotton fabric with sodium periodate, followed by a sulfonation step with sodium bisulfite to provide active sites, which further chelated barium ions (Ba²⁺) to achieve flame retardancy. The morphological and structural characterizations of the fabricated cotton fabrics (COT-SC-Ba) demonstrated that the cleavage of C₂-C₃ free hydroxy groups within the cellulose macromolecule was chemically modified for grafting a considerable number of sulfonic acid groups, and Ba²⁺ ions were effectively immobilized on the macromolecule of the cotton fabric through a chelation effect. Results from cone calorimeter tests (CCTs) revealed that COT-SC-Ba became nonflammable, displayed a delayed ignition time, and decreased the values of the heat release rate (HRR), total smoke release (TSR), effective heat of combustion (EHC), and CO/CO₂ ratio. TG/DTG analysis demonstrated that COT-SC-Ba possessed greater thermal stability, fewer flammable volatiles, and more of a char layer during burning than that of the original cotton fabric. Its residual mass was increased from 0.02% to 26.9% in air and from 8.05% to 26.76% in N₂, respectively. The COT-SC-Ba not only possessed a limiting oxygen index (LOI) of up to 34.4% but could also undergo vertical burning tests evidenced by results such as the non-afterflame, non-afterglow, and a mere 75 mm char length. Those results demonstrated that the combination of SO₃⁻ and Ba²⁺ promoted the formation of a char layer. Moreover, cotton fabric regained its superior flame retardancy after being washed and re-chelated with Ba²⁺. Additional characteristics of the cotton fabric, such as the rupture strength, white degree, and hygroscopicity, were maintained at an acceptable level. In conclusion, this research can offer a fresh perspective on the design and development of straightforward, efficient, eco-friendly, and recoverable fire-retardant fabrics. Full article

The formation of barium sulfate scale is a persistent and formidable challenge across various industrial processes. In order to effectively mitigate this problem, this study proposed the development of an innovative azacrown ether-based macrocycle descaling agent. Using density functional theory, an in-depth analysis of the surface energy of different barium sulfate crystal facets was carried out, together with a detailed investigation into the adsorption properties of the functional groups on the (001) surface. A further comprehensive investigation was carried out to determine how changes in the nitrogen and oxygen atoms in the crown ether framework influence its adsorption affinity to barium ions. In addition, a detailed analysis was carried out to elucidate the molecular interactions between crown ethers with pyridine carboxylic acid side chains and barium sulfate. The newly developed decalcifying macrocycle descaling agent exhibited superior adsorption performance, achieving an adsorption energy for barium ions approximately −4.1512 ev higher than that of conventional DTPA decalcifiers. This remarkable improvement is mainly attributed to the pivotal role of electrostatic forces in the coordination process between the macrocycle descaling agent and barium ions, with an electrostatic potential value reaching −143.37 kcal/mol. This discovery not only introduces a novel approach to the removal of barium sulfate scale but also highlights the significant potential of macrocycle chemistry in industrial applications. Full article

In order to improve the microwave-absorption performance of barium ferrite and broaden its microwave-absorption band, BaFe₁₂O₁₉, Ba_0.95Ca_0.05Fe₁₂O₁₉, and Ba_0.95Ca_0.05Fe_12−xCo_xO₁₉ (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites were synthesized by the solid-state reaction method, and the influence of Co ion substitution on the phase composition, microstructure, magnetic properties, and microwave-absorption ability of the ferrites in this system was studied. Introducing minor Co ions (x < 0.2) facilitated sintering and grain growth. At x ≥ 0.2, XRD revealed the emergence of the Co₂X phase alongside the BaM phase. Increasing Co ion concentration and the secondary X-phase led to slight reductions in saturation magnetization (69 to 63.5 emu/g) and substantial decline in coercivity (2107.02 to 111.21 Oe), attributed to grain size growth and Co₂X’s soft magnetic nature. Notably, Co₂X incorporation significantly enhanced the microwave absorption and provided a tunable absorption band from the Ku to the C band. For a sample with a thickness of 2.0 mm and a doping level of x = 0.2, a minimum reflection loss of −59.5 dB was achieved at 8.92 GHz, with an effective absorption bandwidth of 3.31 GHz (7.07–10.38 GHz). The simple preparation method and good performance make Ba_0.95Ca_0.05Fe_12−xCo_xO₁₉ (x = 0.1, 0.2, 0.3 and 0.4, respectively) hexaferrites promising microwave-absorbing materials. Full article

Amidst the swift expansion of the electric vehicle industry, the imperative for alternative battery technologies that balance economic feasibility with sustainability has reached unprecedented importance. Herein, we utilized Perovskite-based oxide compounds barium titanate (BaTiO₃) and strontium titanate (SrTiO₃) nanoparticles as anode materials for lithium-ion batteries from straightforward and standard carbonate-based electrolyte with 10% fluoroethylene carbonate (FEC) additive [1M LiPF₆ (1:1 EC: DEC) + 10% FEC]. SrTiO₃ and BaTiO₃ electrodes can deliver a high specific capacity of 80 mA h g⁻¹ at a safe and low average working potential of ≈0.6 V vs. Li/Li⁺ with excellent high-rate performance with specific capacity of ~90 mA h g⁻¹ at low current density of 20 mA g⁻¹ and specific capacity of ~80 mA h g⁻¹ for over 500 cycles at high current density of 100 mA g⁻¹. Our findings pave the way for the direct utilization of perovskite-type materials as anode materials in Li-ion batteries due to their promising potential for Li⁺ ion storage. This investigation addresses the escalating market demands in a sustainable manner and opens avenues for the investigation of diverse perovskite oxides as advanced anodes for next-generation metal-ion batteries. Full article