INTRODUCTION:Deficiencies of trace elements including zinc, copper, and selenium, after gastrectomy for gastric cancer (GC) have not been elucidated, although those of iron and vitamin B12 are well documented. This study aimed to assess micronutrient deficiencies among patients with GC before and after different types of gastrectomy. METHODS:The study enrolled 112 patients with GC who underwent curative gastrectomy, and clinical data were obtained after gastrectomy in patients without tumor recurrence. Patients were assigned into four surgical groups: distal gastrectomy with Billroth-I reconstruction, distal gastrectomy with Roux-en Y reconstruction, proximal gastrectomy with double-flap technique reconstruction and total gastrectomy (TG). Serum trace element levels were recorded in addition to iron and vitamin B12during the preoperative and postoperative follow-up periods until 24 months after surgery. In postoperative iron and vitamin B12 deficiency, these supplementations were performed at the direction of physician. RESULTS:Linear mixed-effects models demonstrated significant time effects for selenium, copper, iron, ferritin, hemoglobin and vitamin B12 (p < 0.001), whereas no significant time effect was observed for zinc. Significant time-by-surgery interactions were observed for selenium (p = 0.016), copper (p = 0.014), ferritin (p = 0.023) and hemoglobin (p = 0.001), indicating that postoperative trajectories differed according to surgical procedure for these outcomes. Zinc deficiency was observed in 51.8% of patients with GC before surgery, and a significant time-by-preoperative serum zinc status interaction was observed (p < 0.001), indicating that postoperative serum zinc levels in patients with preoperative zinc deficiency remained low. CONCLUSION:Serum iron, vitamin B12 and selenium levels decline over time following gastrectomy. Iron and selenium deficiencies were pronounced in patients who underwent TG. There was a high prevalence of preoperative zinc deficiency, and postoperative serum zinc levels in these patients remained low. Serum micronutrient levels should be monitored carefully before and after gastrectomy, and supplementation should be provided as needed, particularly in TG.
BACKGROUND:Carrageenan, a sulfated polysaccharide extracted from red seaweeds, is widely used in the food, pharmaceutical, and cosmetic industries due to its gelling, thickening, and stabilizing properties. SUMMARY:Its widespread use in the Western diet and processed foods has raised scientific interest regarding its health effects. Evidence remains contradictory: some studies report antioxidant, antiviral, antitumor, and immunomodulatory benefits, whereas others suggest potential adverse outcomes, including impaired glucose metabolism, intestinal inflammation, and immune dysregulation. These effects appear to depend on carrageenan type, molecular weight, purity, dosage, and host-related factors. Regulatory bodies such as the FDA and EFSA generally consider carrageenan safe, although concerns remain regarding infant formulas and long-term exposure. KEY MESSAGES:Carrageenan cannot be uniformly classified as beneficial or harmful. Its biological effects are context-specific, and further well-designed clinical and mechanistic studies are needed to clarify dose-response relationships, safety in vulnerable populations, and implications for industry and public health nutrition.
INTRODUCTION:Cancer cachexia is a clinically important condition associated with worsening nutritional status and difficulty in continuing anticancer treatment. Although multimodal approaches combining exercise, nutritional support, and pharmacological treatment may improve symptoms and delay disease progression, the optimal timing of pharmacological intervention remains unclear. Conventional diagnostic criteria have largely been based on Western populations and may not adequately identify patients at an earlier stage in Asian populations. In 2023, the Asian Working Group for Cachexia (AWGC) proposed diagnostic criteria more suitable for Asian populations; however, it remains unclear to what extent this change has been reflected in real-world prescribing practices for anamorelin. In this study, we examined the anamorelin prescribing trends before and after the introduction of the AWGC criteria and evaluated the associations of cachexia stage and baseline performance status (PS) with treatment continuation. METHODS:We conducted a retrospective chart review of patients who received anamorelin between April 2021 and March 2025 at Showa Medical University Hospital and Showa Medical University Northern Yokohama Hospital. The primary outcome was the duration of treatment continuation. Secondary evaluation focused on chronological changes in the PS. Prescribing patterns before and after the introduction of the AWGC criteria were compared, and subgroup analyses were performed according to Fearon's classification and baseline PS. RESULTS:Of 130 patients prescribed anamorelin during the study period, data from 98 were included in the final analysis after exclusions. Overall, 68 and 30 patients were classified into the pre-AWGC and post-AWGC groups, respectively, with no major differences in key background characteristics or clear changes in the prescribing patterns between the groups. According to Fearon's classification, 90 and 8 patients had cachexia and pre-cachexia, respectively. The pre-cachexia group exhibited a significantly longer continuation duration than did the cachexia group (median: 211.5 vs. 34.5 days, log-rank p = 0.013). Patients with baseline PS of 0-1 demonstrated a significantly longer continuation duration than did those with a PS of 2-4 (median 71 vs. 25 days, log-rank p < 0.001). No marked deterioration in the PS over time was observed. CONCLUSION:The prescribing patterns of anamorelin did not substantially change after the introduction of the AWGC criteria. Conversely, longer treatment continuation was observed in patients at an earlier stage of cachexia and in those with preserved baseline PS. Thus, in addition to updated diagnostic criteria, earlier intervention and initiation at a stage with better general condition may be important when optimizing the timing of anamorelin treatment.
Near-wellbore formation damage in carbonate reservoirs is commonly characterized by the coexistence of complex organic and inorganic deposits, which severely deteriorate reservoir permeability and oil well productivity. Conventional acidizing schemes are largely based on experimental data obtained from pure mineral cores, which fail to realistically represent the compositional characteristics of in-situ plugging materials and their influence on acid-rock reaction behavior, thereby limiting their engineering applicability. To address this issue, the organic-inorganic composite composition of near-wellbore plugging materials was first systematically characterized, and artificially damaged cores that reflect the actual damage features were subsequently constructed. On this basis, a targeted hybrid acid system was developed. Core-flooding tests demonstrated that this system achieved a permeability ratio of 18 times (i.e., a 1700% increase), significantly outperforming conventional hydrochloric acid. Key reaction kinetics parameters obtained from static dissolution and rotating disk experiments were utilized to construct and calibrate a dual-scale model. Numerical simulations confirmed that the hybrid acid system generates smoother, more elongated wormholes at lower injection rates compared to the HCl system, explaining its superior deep-penetration capability. This study demonstrates that the hybrid acid system developed herein, benefiting from the synergistic complementarity between organic and inorganic acids, effectively targets the organic-inorganic composite plugging characteristics of ZH Well. The system simultaneously achieves efficient dissolution and enhanced deep penetration, thereby significantly improving stimulation performance in complex and severely damaged carbonate reservoirs.
In order to improve the corrosion inhibition performance of Schiff base (SB) under high-temperature and high-concentration HCl, the effect of the preparation ratio of cerium nitrate and SB-SBES on its corrosion inhibition performance was systematically studied by relevant experiments and molecular dynamics simulation at 363 K.Among them, SB-SBES is a mixture of SB and 2-bromoethyl sulfonate at a ratio of 1: 0.9. The addition amount of Schiff base mixtures after compounding is 5%. The corrosion inhibitor achieved optimal performance when the ratio of cerium nitrate to the SB-SBES was 0.2:1, the weight loss corrosion inhibition efficiency, polarization corrosion inhibition efficiency, and impedance corrosion inhibition efficiency reached 90.2%, 95.2%, and 96.2%. The SB mixture of SB-SBES: cerium nitrate = 1: 0.2 was named SB-SBES-Ce. Electrochemical studies show that SB-SBES-Ce is a mixed inhibitor, which mainly increases the surface film resistance (R-f) and charge transfer resistance (R-ct) of 2024 aluminum alloy and plays a certain corrosion inhibition effect. XPS results showed that SB-SBES-Ce was adsorbed on the metal surface. Molecular dynamics simulation shows that corrosion inhibitor is spontaneously adsorbed on the surface of 2024 aluminum alloy in parallel. [GRAPHICS]
Delaying Leidenfrost effect is of great importance for effective cooling of electronic devices. In this article, the effects of different droplet properties on boiling phenomena have been experimentally studied. To endow the droplets with different properties, the sodium dodecyl sulfate (SDS) and Al2O3 nanoparticles are added to deionized water. The Al2O3 nanofluids with SDS (NFWS) and without SDS (NFNS) are prepared with concentrations from 0.1% to 0.5%, respectively. Static evaporation curve tests are conducted. And images of single droplet impacting on the heated aluminum surface (70 degrees C to 350 degrees C) under various impact velocities and concentrations are captured continuously. The results indicate that the maximum evaporation time of the NFWS droplets decreases with increasing concentration. However, the peak value of the maximum evaporation time occurs at a concentration of 0.3% for the NFNS droplets. The maximum spreading factor increases as the impact velocity rises and decreases as the nanofluid concentration increases. For the NFWS droplets, a larger maximum spreading factor is observed. A boiling regime related to impact velocities and surface temperatures is presented. The Leidenfrost temperature of NFNS droplets is higher than that of NFWS droplets at low impact velocity. As the impact velocity increases, it shows an opposite trend. Finally, the predictive models for the maximum spreading factor and dynamic Leidenfrost temperature are established. The higher prediction accuracy of models can be obtained when considering the NFWS and NFNS droplets, respectively. This study can provide valuable insights into the impact behaviors of Al2O3 nanofluid on high-temperature surface. [GRAPHICS]
Oil-well cement stone is inherently brittle and prone to cracking, posing serious threats to construction safety and long-term zonal isolation. To improve wellbore sealing integrity and service life, mullite whiskers were synthesized via a molten-salt method. A novel synergistic toughening system combining mullite whiskers and halloysite nanotubes (HNTs) is proposed to reduce cement brittleness and cracking. Mechanical tests reveal an optimal blend of 0.7% mullite whiskers plus 1% HNTs (labeled M7-H1). Compared with the neat reference, this formulation increases 3-day and 7-day compressive strength by 49.39% +/- 3.5% and 58.37% +/- 3.5%, respectively, and raises tensile strength by 32.23% +/- 3.1% and 29.30% +/- 2.9%. XRD, TGA, and MIP analyses demonstrate that both mullite whiskers and HNTs act as nucleation sites for hydration products, accelerating secondary hydration and promoting calcium-silicate-hydrate (C-S-H) gel formation. A "bridging-nucleation-filling" tri-modal reinforcement mechanism is thereby established. The concurrent refinement of the pore structure reduces total porosity from 33.38% +/- 0.42% to 24.34% +/- 0.25% and cuts the fraction of detrimental pores (>50nm) from 59.9% to 36.2%. Owing to the facile, low-cost synthesis of the mullite whiskers, the proposed approach offers a readily deployable, high-performance solution for achieving durable cement-sheath sealing and life extension in deep and shale oil/gas wells. [GRAPHICS] .
Oily wastewater poses substantial environmental and health threats, driving the need for efficient and eco-friendly treatment solutions. In this study, we develop a robust magnesium hydroxide/polyvinyl alcohol/zinc oxide (Mg(OH)(2)/PVA/ZnO) composite membrane on copper mesh via a facile one-step electrodeposition process conducted at elevated temperature. The temperature of the electroplating bath critically governs the kinetic behavior of particle deposition, thereby dictating the resulting membrane structure, stability, and oil-water separation performance. The optimized membrane prepared at 82 degrees C exhibits exceptional oil-water separation performance, achieving 99.8% +/- 0.11% separation efficiency, a high water flux of 3.7 & times; 10(5) L & centerdot;m(-2)& centerdot;h(-1), and stable operation over 1,800 separation cycles with minimal efficiency loss (>99.6%). It also exhibits high intrusion pressure (>2.3 kPa) and superior oil repellency. Moreover, the membrane demonstrates outstanding mechanical resilience against water impact, tape peeling, and abrasion, along with chemical stability across alkaline and saline environments (pH =7, 9). With the capability to efficiently separate various oil-water mixtures and surfactant-stabilized emulsions, this composite membrane presents a promising solution for real-world oily wastewater remediation. [GRAPHICS]
The removal of molybdenum (VI) from contaminated water is challenging due to its high solubility and environmental mobility. This study explores the zirconium-based metal-organic framework UiO-66 as an efficient adsorbent for Mo(VI) removal and elucidates its adsorption mechanism through systematic physicochemical and kinetic analyses. UiO-66 was synthesized via a solvothermal method, and its crystalline structure, functional groups, morphology, and porosity were confirmed by XRD, FTIR, SEM, TEM, and N-2 adsorption-desorption analyses, indicating the formation of a stable and highly porous framework. Batch adsorption experiments were conducted to investigate the effects of pH, temperature, contact time, initial concentration, and competing ions. The adsorption process exhibited strong pH dependence, with optimal performance at pH 3. Under these conditions, UiO-66 achieved a maximum adsorption capacity of 275.9 +/- 0.9 mg g(-1) at 45 degrees C, outperforming many conventional adsorbents. Kinetic data followed the pseudo-second-order model (R-2 = 0.998), suggesting chemisorption as the rate-limiting step, while equilibrium data were best described by the Langmuir isotherm, indicating monolayer adsorption on homogeneous sites. Selectivity studies confirmed preferential Mo(VI) uptake in the presence of competing ions. Thermodynamic analysis revealed that the adsorption is spontaneous (Delta G < 0) and endothermic (Delta H > 0). Additionally, UiO-66 demonstrated excellent reusability over five adsorption-desorption cycles, maintaining high efficiency and structural stability. The adsorption mechanism is mainly attributed to electrostatic attraction and coordination interactions between molybdate species and Zr-O clusters. These findings highlight UiO-66 as a promising material for efficient water purification applications. [GRAPHICS]
Herein, we report a crosslinked (cl) hydrogel of spent tea leaves (STLs) with two monomers, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) and acrylamide (Am), via free radical graft copolymerization using potassium persulfate and N, N '-Methylenebisacrylamide as the initiator and cross-linker, respectively. The as-synthesized hydrogel, STLs-cl-Poly(AMPSA-co-Am), was characterized using FTIR, FESEM-EDX, TGA, BET, zeta potential, and surface charge analysis. The STLs-cl-Poly(AMPSA-co-Am) hydrogel was evaluated for the adsorption of cationic dyes, namely, methylene blue (MB), and crystal violet (CV) from their aqueous solutions using various parameters, such as time (0-90 min), temperature (25-50 degrees C), pH (2.0-10.0), and concentration (25-400 ppm). The adsorption process was analyzed using kinetic models, namely pseudo-first-order, pseudo-second-order (PSO), and Elovich, and isotherm models, such as Langmuir, Freundlich, and Temkin. The maximum removal efficiencies for MB and CV were 90.50 +/- 0.63% and 85.62 +/- 0.59%, respectively. The adsorption process was best described by PSO and Langmuir model, confirming monolayer adsorption, with maximum adsorption capacities of 375.53 +/- 6.33 and 344.05 +/- 4.49 mg g(-1) for MB and CV, respectively. The STLs-cl-Poly(AMPSA-co-Am) hydrogel showed high reusability for 8 cycles with a cumulative adsorption capacity of 682.76 mg g(-1) for MB and 622.43 mg g(-1) for CV. Thus, a novel STLs-based hydrogel was developed via free-radical graft copolymerization, in which STLs function simultaneously as a precursor and bio-filler, providing ample functional groups and a porous structure that enhance interactions with cationic dyes. This dual functionality enables effective biomass waste valorization for cost-effective, reusable, and environmentally sustainable dye removal from aqueous solutions. [GRAPHICS]
The increasing demand for eco-friendly and multifunctional nanomaterials has intensified interest in green synthesis strategies for biomedical and environmental applications. In this study, AgMgO nanocomposites (NCs) were successfully synthesized using Parmelia tiliaceae extract as a biological reducing and stabilizing agent. The synthesized NCs were comprehensively characterized by UV-Vis spectroscopy, SEM, STEM, DLS, FTIR, EDX, XRD, and TGA analyses, confirming their spherical morphology, homogeneous distribution, and particle size in the range of 20-80 nm. The biological and functional properties of the AgMgO NCs were systematically evaluated. The nanocomposites exhibited notable antibacterial activity, with a maximum inhibition zone of 17.3 +/- 0.5 mm against Escherichia coli O157:H7 ATCC 35150, and a strong antibiofilm effect, achieving up to 94% inhibition against Staphylococcus aureus ATCC 29213. In addition, effective antialgal activity was observed across all tested concentrations. The photocatalytic performance of the NCs demonstrated moderate efficiency, achieving 61.8% degradation of methylene blue (2 mg/L) within 180 min, indicating their potential as a proof-of-function system for environmental remediation. Furthermore, the synthesized NCs showed significant cytotoxic activity against A549 lung cancer cells. Overall, the results demonstrate that lichen-mediated AgMgO NCs are cost-effective, biocompatible, and multifunctional materials with promising applications in antimicrobial, environmental, and biomedical fields.
In this study, Cu2S-ZnS reduced graphene oxide (Cu2S-ZnS-rGO) nanocomposite was synthesized for the dispersive solid-phase extraction (DSPE) of trace levels of lead ion (Pb2+), followed by its determination using electrothermal atomic absorption spectrometry (ETAAS). The synthesized nanocomposite was characterized using X-Ray Diffraction (XRD) analysis, Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared spectrophotometry (FT-IR). Key parameters influencing the extraction efficiency-including sample pH, adsorbent dosage, extraction time, and desorption conditions-were thoroughly optimized. Based on the results, the proposed method exhibited good linearity in the range of 0.10-8.0 mu g/L, with a correlation coefficient (R-2) of 0.9988. The limits of detection (LOD) and quantification (LOQ), calculated as 3S(b)/m and 10S(b)/m, were found to be 0.024 mu g/L and 0.080 mu g/L, respectively. The relative standard deviation (RSD) for six replicate measurements of a 1.0 mu g/L Pb2+ solution was 4.3%. The adsorption mechanism was further investigated using adsorption isotherm models, which indicated that Pb2+ adsorption onto the adsorbent conformed to the Langmuir isotherm model, with a maximum adsorption capacity of 98.0 mg/g. Finally, the developed method was effectively employed to quantify trace amounts of Pb2+ in water and rice samples. [GRAPHICS]
In this study ZnO nanostructures (NSs), CdS nanoparticles (NPs), and ZnO-CdS nanocomposites utilizing simple and affordable technologies were used to fabricate a coating with superhydrophobicity and photocatalytic activity following stearic acid (SA) modification for water pollution treatment. The higher hierarchical (micro-nano) structure increased the water contact angle (WCA) value from 56.6 degrees and 20 degrees for the substrates to 143 +/- 2 degrees when the composite nanomaterial was deposited, while it reached the value of 153 +/- 3 degrees, which indicates the superhydrophobicity coating formation. XRD, FE-SEM, Fourier transform infrared (FTIR), EDS, and UV-Vis spectroscopy were used to study the nanomaterial's and superhydrophobic coatings, and the water contact angle was determined to assess wettability. X-ray diffraction revealed that the polycrystalline ZnO-CdS nanocomposite comprises the hexagonal wurtzite phase together with the hexagonal phase of ZnO and CdS. Pure ZnO has a 3.4 eV band gap, whereas CdS has band gap of 2.55 eV. The ZnO-CdS nanocomposite was utilized to test methylene blue (MB) dye photodegradation under visible light before and after SA treatment. After 90 min. of irradiation, the pure nanocomposite photodegraded 90% of the MB and 85% of the superhydrophobic (ZnO-CdS) coating.
Numerous studies have reported the polymerization and stabilization of castor oil (CO) with isocyanates for the synthesis of polyurethanes (PUs) intended for adhesive applications. In this work, we propose a novel strategy for stabilizing PU emulsions, employing modified styrene-co-maleic anhydride (SMA) copolymers as surfactants, in combination with carbon nanotubes (CNTs). We synthesized emulsified PU nanocomposites using isophorone diisocyanate and 4,4 '-dicyclohexylmethane diisocyanate (H12MDI), which were reacted with CO as the polyol source. Stabilization of the PU adhesives was achieved by emulsifying the resulting PUs in the presence of a modified SMA copolymer, functionalized via imidization reaction with tallow amine with two different styrene and maleic anhydride ratios, along with water and functionalized CNTs. The resulting material is a stable, flowable PU emulsion capable of effectively bonding wood substrates. Lap shear tests were performed to evaluate the adhesive bonding strength showing values of 1.2 MPa. The presence of the SMA-based plays a crucial role in emulsion stability, as it reduces the oil-water interfacial tension by approximately 40%. The combination of CNTs and SMA copolymers resulted in emulsions that remained stable for over ten months after preparation exhibiting droplet sizes smaller than 2 & micro;m in diameter, maintaining their performance as adhesive materials.
Conventional admixtures for oil well cement are associated with high costs and inadequate utilization of industrial solid wastes. This study addresses these challenges by introducing modified Titanium-extracted slag (TES) as a sustainable alternative. It was observed that the hydration of TES leads to the formation of layered double hydroxides (LDHs) within the cementitious matrix. To enhance its reactivity, TES was modified through ball milling, washing, and calcination. The washing process effectively reduced the chloride ion (Cl-) content, while calcination shortens the average chain length of silicate glass and promotes the release of Al3+, thereby increasing its amorphous activity. The hydration behavior and microstructural evolution of TES-blended cementitious composites were systematically investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Furthermore, the hydration mechanism was elucidated by applying the Krstulovic-Dabic (K-D) kinetic model. Results indicate that both washed and calcined TES promote the formation of calcium aluminosilicate hydrate (C-(A)-S-H) gels and LDHs. These phases enhance the density of the cement stone by improving the connectivity of the C-(A)-S-H network and filling pores with LDHs. In summary, this study demonstrates that the tailored incorporation of modified TES enables simultaneous waste valorization and enhancement of cement stone properties, offering an eco-friendly and cost-effective solution for high-temperature well cementing applications. [GRAPHICS] .
The present study aimed to develop and optimize ketoconazole (KTZ)-loaded transniosomes (TN) for improved dermal delivery and therapeutic efficacy. KTZ was characterized using differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR) to confirm its thermal properties and chemical integrity. KTZ-loaded TN vesicles were formulated via the thin-film hydration method using Leciva-S70, cholesterol, Span 60, and sodium cholate. The formulation was optimized in terms of vesicle size, polydispersity index (PDI), and entrapment efficiency (%EE) using a three-factor, three-level Box-Behnken design. The optimized TN exhibited a vesicle size of 105.2 +/- 2.15 nm, PDI of 0.29 +/- 0.02, zeta potential of -29.63 +/- 2.21 mV, and %EE of 87.63 +/- 5.97. Transmission electron microscopy (TEM) confirmed spherical morphology. In vitro release studies demonstrated sustained drug release (94.97 +/- 2.91% over 24 h) compared to KTZ suspension (43.49 +/- 2.98%), following non-Fickian diffusion kinetics. Antioxidant activity, assessed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, showed enhanced free radical scavenging for TN compared to pure KTZ. The optimized TN was incorporated into a Carbopol 934 P gel matrix, exhibiting favorable pH (7.1 +/- 0.1), spreadability, extrudability, and mechanical properties. Ex vivo permeation studies revealed significantly higher KTZ flux from TN gel (5.895 & micro;g/cm2/h) versus conventional gel (3.560 & micro;g/cm2/h). Dermatokinetic analysis indicated increased drug retention in epidermal and dermal layers with TN gel. Short-term stability studies demonstrated no changes in physicochemical properties over three months. Overall, the KTZ-loaded TN gel represents a promising nanocarrier system for enhanced topical delivery, improved skin penetration, and sustained therapeutic action.
Conventional Class G oil well cement suffers from considerable strength retrogression at temperatures over 200 degrees C, principally due to the hydrothermal conversion of C-S-H gel into coarse, permeable alpha-C2SH phases. The long-term zonal isolation of ultra-deep wells is seriously threatened by this phenomenon. This study evaluates the usefulness of gamma-phase nano-alumina (NA) in strengthening silica-stabilized Class G cement systems under simulated downhole conditions of 240 degrees C to address this issue. For up to 28 days, cement slurries containing varying concentrations of NA (0%-2.0% BWOC) were cured. Rheometry, Mercury Intrusion Porosimetry (MIP), Scanning Electron Microscope/Energy Dispersive Spectrometer (SEM/EDS), X-ray diffraction analysis (XRD),Si-29 Nuclear Magnetic Resonance (Si-29 NMR), and Thermogravimetry/Derivative Thermogravimetry (TG/DTG) were used to systematically characterize the rheological behavior, mechanical evolution, and microstructural changes. The results show that the ideal dosage is 0.5% NA, which maintains a safe thickening period of 105 min, reduces API fluid loss by 27.3%, and slows the strength retrogression after 28 days. Differently, doses more than 1.0% create a considerable "rapid stiffening" impact. Mechanistically, 0.5% NA refines the median pore diameter by 8.89% through a physical nucleation effect and stimulates the production of thermodynamically stable Al-substituted tobermorite, thereby limiting the growth of coarse xonotlite crystals. So, the introduction of 0.5% well-dispersed NA provides a dual strengthening mechanism-pore structure refinement and phase stabilization-offering a realistic alternative for constructing high-performance cement sheaths in ultra-high temperature conditions.
Magnetic activated biochar (MAB) was synthesized from waste Deglet Nour date pits, an abundant palm byproduct from Algeria, through ZnCl2 chemical activation followed by Fe3O4 nanoparticle loading via co-precipitation, and applied for crystal violet (CV) removal from water. Comprehensive characterization by SEM-EDX, AFM, TEM, FTIR, TGA, XRD, VSM, and N-2 physisorption verified the successful activation and magnetization of biochar. TEM images of MAB confirmed that Fe3O4/ZnFe2O4 nanoparticles (11-47 +/- 0.1 nm) are well-dispersed on the micron-sized biochar support. MAB exhibited an enhanced BET surface area of 870.6 (+/- 0.01) m(2).g(-1) and a large pore volume of 0.514 (+/- 0.001) cm(3).g(-1), exceeding those of the pristine date-pit biochar (DPB; 143.2 +/- 0.01 m(2).g(-1) and 0.0662 +/- 0.001 cm(3).g(-1)) by more than sixfold. Adsorption kinetics indicated a rapid uptake with 57% removal within 5 min under single-component conditions and up to 86% in the binary system with methylene blue (cooperative removal). The Langmuir maximum adsorption capacity of MAB reached 537.8 +/- 10.18 mg.g(-1), whereas DPB showed 63.0 +/- 4.094 mg.g(-1) (at 45 degrees C +/- 1 degrees C). Thermodynamic studies indicated a spontaneous, exothermic, and entropy-driven behavior. Ethanol CV-desorption confirmed the reversibility of the process and the recyclability of MAB. Adsorption was controlled by pi-pi interactions, pore filling, hydrogen bonding, n-pi interactions, surface complexation, and van der Waals forces. The production cost of MAB was estimated at 2.16-4.86 US$.kg(-1), while the operational cost of CV removal was only 0.004-0.014 US$.g(-1) of dye, demonstrating technical efficiency, economic feasibility, and sustainable valorization of date pit waste.
Reducing the injection pressure in low-permeability reservoirs is key to achieving efficient water flooding operations, this paper synthesized different types of middle phase microemulsion systems by low-energy emulsification method, synthesized and screened out the microemulsion system suitable for low-permeability sandstone reservoirs. Through online displacement CT and nuclear magnetic resonance scanning technology experiments, the effect of pressure reduction and injection enhancement, and the ability to improve the remaining oil occurrence state of the optimized middle phase microemulsion system are verified. The research results indicate that:(1) The optimized nano-microemulsion system formula is: (1) 10% OP-10 + 15% pentanol + 2% NaCl + 36.5% white oil + 36.5% pure water; (2) 5% HSB1618 + 4% pentanol + 3% NaCl + 44% white oil + 44% pure water; (3) 6% SLS + 9% pentanol + 4% NaCl + 45% white oil + 45% pure water; (2) Microemulsion can strip crude oil from fine pore throats by inducing the rock wettability reversal and miscibility of crude oil, and the displacement pressure decreases by 18.2%similar to 33.3%. (3) Microscopic mechanism shows that the microemulsion can promote the transformation of residual oil occurrence state from continuous phase to dispersed droplets, and the core displacement efficiency is obviously improved. The low interfacial tension and strong wettability modification capabilities of OP-10 microemulsion enable to reduce capillary resistance, peel off the oil film on the rock surface, the nano-scale particle size enhances its percolation ability in low-permeability pore throats. This paper provides a theoretical basis for the efficient water injection development of low-permeability oil reservoirs.
Conventional separation processes often encounter issues such as redundant separation steps and low separation efficiency when treating fine quartz and muscovite, owing to the similar particle sizes and properties. To address these problems, this study explored the feasibility of enhancing gravity separation through the flocculation effects. Using the specific "bridging" capability of anionic polyacrylamide (APAM), the efficient separation of fine quartz and muscovite was achieved under near-neutral conditions. Sedimentation experiments were conducted to compare the flocculation behaviors of the two minerals using different types of polyacrylamide (PAM). The selective flocculation behavior and adsorption mechanism of APAM on the two minerals were systematically analyzed using XRD, XRF, microscopic observation, Zeta potential, FTIR and XPS. The results showed that APAM could effectively flocculate fine muscovite but had a weaker coagulation effect on quartz. When the APAM concentration reached 100 mg/L, the difference in sedimentation recovery rates between the two minerals was 78.8 +/- 2.5%. In mixed mineral systems, after sedimentation separation, the suspension product contained 88.49 +/- 0.23% quartz with a recovery rate of 63.30 +/- 0.23%, whereas the sediment product contained 60.19 +/- 0.12% muscovite with a recovery rate of 81.84 +/- 0.12%. Mechanistic studies indicated that APAM specifically binds to the muscovite surface via hydrogen bonding and electrostatic adsorption, whereas its interaction with quartz is relatively weak. Furthermore, this study constructed a selective adsorption model to illustrate the dynamic process by which APAM separates quartz and muscovite under natural conditions.
