Search Results (1,728)

The stability of nitrogen gas foam hinders its applicability in petroleum applications. Fly ash nanoparticles and clay improve the N₂ foam stability, and flue gas foams provide a cost-effective solution for carbon capture, utilization, and storage (CCUS). This study examines the stability, volume, and bubble structure of foams formed using two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS), along with the cationic surfactant cetyltrimethylammonium bromide (CTAB), selected for their comparable interfacial tension properties. Analysis of foam stability and volume and bubble structure was conducted under different CO₂/N₂ mixtures, with half-life and initial foam volume serving as the evaluation criteria. The impact of fly ash and clay on SDS-N₂ foam was also evaluated. The results showed that foams created with CTAB, SDBS, and SDS exhibit the greatest stability in pure nitrogen, attributed to low solubility in water and limited gas diffusion. SDS showed the highest foam strength attributable to its comparatively low surface tension. The addition of fly ash and clay significantly improved foam stability by migrating to the gas–liquid interface, creating a protective barrier that reduced drainage. Both nano fly ash and clay improved the half-life of nitrogen foam by 11.25 times and increased the foam volume, with optimal concentrations identified as 5.0 wt% for fly ash and 3.0 wt% for clay. This research emphasizes the importance of fly ash nanoparticles in stabilizing foams, therefore optimizing a foam system for enhanced oil recovery (EOR). Full article

Low-commercial-value natural pistachios (broken, closed, or immature) can be revalorised through oil extraction, obtaining a high-quality oil and partially defatted flour as by-product. This study evaluated the techno-functional and nutritional properties of the flours obtained by hydraulic press (HP) and single-screw press (SSP) systems, combined with pretreatment at 25 °C and 60 °C. The extraction method significantly influenced flour’s characteristics, underscoring the need to tailor processing conditions to the specific technological requirements of each food application. HP-derived flours presented lighter colour, greater tocopherol content, and higher water absorption capacity (up to 2.75 g/g), suggesting preservation of hydrophilic proteins. SSP-derived flours showed higher concentration of protein (44 g/100 g), fibre (12 g/100 g), and minerals, and improved emulsifying properties, enhancing their suitability for emulsified products. Pretreatment at 25 °C enhanced functional properties such as swelling power (~7.0 g/g) and water absorption index (~5.7 g/g). The SSP system achieved the highest oil extraction yield, with no significant effect of pretreatment temperature. The oils extracted showed high levels of unsaturated fatty acids, particularly oleic acid (~48% of ω-9), highlighting their nutritional and industrial value. The findings support the valorisation of pistachio oil extraction by-products as functional food ingredients, offering a promising strategy for reducing food waste and promoting circular economy approaches in the agri-food sector. Full article

The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal risk to humans and the environment, which has attracted the interest of an emerging consumer market and, consequently, the cosmetics industry. The aim of the present study was to produce a biosurfactant from the yeast Starmerella bombicola ATCC 22214 cultivated in a mineral medium containing 10% soybean oil and 5% glucose. The biosurfactant reduced the surface tension of water from 72.0 ± 0.1 mN/m to 33.0 ± 0.3 mN/m after eight days of fermentation. The yield was 53.35 ± 0.39 g/L and the critical micelle concentration was 1000 mg/L. The biosurfactant proved to be a good emulsifier of oils used in cosmetic formulations, with emulsification indices ranging from 45.90 ± 1.69% to 68.50 ± 1.10%. The hydrophilic–lipophilic balance index demonstrated the wetting capacity of the biosurfactant and its tendency to form oil-in-water (O/W) emulsions, with 50.0 ± 0.20% foaming capacity. The biosurfactant did not exhibit cytotoxicity in the MTT assay or irritant potential. Additionally, an antioxidant activity of 58.25 ± 0.32% was observed at a concentration of 40 mg/mL. The compound also exhibited antimicrobial activity against various pathogenic microorganisms. The characterisation of the biosurfactant using magnetic nuclear resonance and Fourier transform infrared spectroscopy revealed that the biomolecule is a glycolipid with an anionic nature. The results demonstrate that biosurfactant produced in this work has potential as an active biotechnological ingredient for innovative, eco-friendly cosmetic formulations. Full article

Ecotribology focuses on both saving energy resources and reducing environmental pollution. Considering environmental concerns, water-based nanolubricants have gained significant attention over conventional oil-based ones. Non-ecotoxic and highly environmentally friendly nanoadditives were chosen for nanolubricant synthesis, especially considering their use at elevated temperatures. In this study, hexagonal boron nitride nanosheets (hBNNSs) and titanium dioxide nanoparticles (TiO₂ NPs) were used to prepare water-based lubricants with glycerol and surfactant sodium dodecyl benzene sulfonate (SDBS) in water under ultrasonication. An Rtec ball-on-disk tribometer was used to investigate the tribological performance of the synthesised water-based lubricants containing different nano-hBN/TiO₂ concentrations, with dry and water conditions used as benchmarks. The results indicated that the water-based nanolubricant containing 0.5 wt% hBN and 0.5 wt% TiO₂ exhibited the best tribological performance at both ambient (25 °C) and elevated (500 °C) temperatures. This optimal concentration leads to a reduction in the coefficient of friction (COF) by 72.9% and 37.5%, wear of disk by 62.5% and 49%, and wear of ball by 74% and 69% at ambient and elevated temperatures, respectively, compared to that of distilled water. Lubrication mechanisms were attributed to the rolling, mending, tribofilm, solid layer formation, and synergistic effects of hBNNSs and TiO₂ NPs. Full article

Background/Objectives: Holy basil (Ocimum tenuiflorum L.) essential oil exhibits antioxidant, antimicrobial, and anesthetic activities, mainly due to eugenol, methyl eugenol, and β-caryophyllene. However, its clinical application is limited by poor water solubility, instability, and low bioavailability. This study developed and compared two delivery systems, self-nanoemulsifying drug delivery systems (SNEDDS) and microemulsions (ME), to enhance their stability and fish anesthetic efficacy. Methods: The optimized SNEDDS (25% basil oil, 8.33% coconut oil, 54.76% Tween 80, 11.91% PEG 400) and ME (12% basil oil, 32% Tween 80, 4% sorbitol, 12% ethanol, 40% water) were characterized for droplet size, PDI, zeta potential, pH, and viscosity. Stability was evaluated by monitoring droplet size and PDI over time and by determining the retention of eugenol, methyl eugenol, and β-caryophyllene after storage at 45 °C. Fish anesthetic efficacy was tested in koi carp (Cyprinus carpio var. koi). Results: SNEDDS maintained a small droplet size (~22.78 ± 1.99 nm) and low PDI (0.188 ± 0.088 at day 60), while ME showed significant size enlargement (up to 177.10 ± 47.50 nm) and high PDI (>0.5). After 90 days at 45 °C, SNEDDS retained 94.45% eugenol, 94.08% methyl eugenol, and 88.55% β-caryophyllene, while ME preserved 104.76%, 103.53%, and 94.47%, respectively. In vivo testing showed that SNEDDS achieved faster anesthesia (114.70 ± 24.80 s at 120 ppm) and shorter recovery (379.60 ± 15.61 s) than ME (134.90 ± 4.70 s; 473.80 ± 16.94 s). Ethanol failed to induce anesthesia at 40 ppm and performed poorly compared to SNEDDS and ME at other concentrations (p < 0.0001). Conclusions: SNEDDS demonstrated superior physical stability and fish anesthetic performance compared to ME. These findings support SNEDDS as a promising formulation for delivering holy basil essential oil in biomedical and aquaculture applications. Full article

Oral delivery of hydrophobic compounds remains challenging due to their poor aqueous solubility and the potential toxicity associated with conventional surfactant-based emulsions. To address these issues, we present a surfactant-free encapsulation strategy using electrosprayed alginate hydrogel beads for the stable and controlled delivery of hydrophobic oils. Hydrophobic compounds were dispersed in high-viscosity alginate solutions without surfactants via ultrasonication, forming kinetically stable oil-in-water dispersions. These mixtures were electrosprayed into calcium chloride baths, yielding monodisperse hydrogel beads. Higher alginate concentrations improved droplet sphericity and suppressed phase separation by enhancing matrix viscosity. The resulting beads exhibited stimuli-responsive degradation and controlled release behavior in response to physiological ionic strength. Dense alginate networks delayed ion exchange and prolonged structural integrity, while elevated external ionic conditions triggered rapid disintegration and immediate payload release. This simple and scalable system offers a biocompatible platform for the oral delivery of lipophilic active compounds without the need for surfactants or complex fabrication steps. Full article

This study analyzes the lacustrine hydrocarbon source rocks of the Lower Cretaceous in the Erdengsumu sag of the Erlian Basin, evaluating their characteristics and identifying areas with oil resource potential, while also investigating the ancient lake environment, material source input, and controlling factors, ultimately developing a sedimentary model for lacustrine hydrocarbon source rocks. The findings suggest the following: (1) The lower Tengger Member (K₁bt₁) and the Aershan Formation (K₁ba) are the primary oil-producing strata, with an effective hydrocarbon source rock exhibiting a lower limit of total organic carbon (TOC) at 0.95%. The Ro value typically remains below 0.8%, indicating that high-maturity oil production has not yet been attained. (2) The oil generation threshold depths for the Dalestai and Sayinhutuge sub-sags are 1500 m and 1214 m, respectively. The thickness of the effective hydrocarbon source rock surpasses 200 m, covering areas of 42.48 km² and 88.71 km², respectively. The cumulative hydrocarbon generation intensity of wells Y1 and Y2 is 486 × 10⁴ t/km² and 26 × 10⁴ t/km², respectively, suggesting that the Dalestai sub-sag possesses considerable petroleum potential. The Aershan Formation in the Chagantala sub-sag has a maximum burial depth of merely 1800 m, insufficient to attain the oil generation threshold depth. (3) The research area’s productive hydrocarbon source rocks consist of organic matter types I and II₁. The Pr/Ph range is extensive (0.33–2.07), signifying a reducing to slightly oxidizing sedimentary environment. This aligns with the attributes of small fault lake basins, characterized by shallow water and robust hydrodynamics. (4) The low ratio of ∑nC₂₁₋/∑nC₂₂₊ (0.36–0.81), high CPI values (>1.49), and high C₂₉ sterane concentration suggest a substantial terrestrial contribution, with negligible input from aquatic algae–bacterial organic matter. Moreover, as sedimentation duration extends, the contribution from higher plants progressively increases. (5) The ratio of the width of the deep depression zone to the width of the depression in the Erdengsumu sag is less than 0.25. The boundary fault scale is small, its activity is low, and there is not much input from the ground. Most of the source rocks are in the reducing sedimentary environment of the near-lying gently sloping zone. Full article

Oil and gas field water not only contains low concentrations of lithium but also a lot of suspended matter, inorganic salt, and organic matter. Both inorganic ions and organic substances influence the extraction of lithium. To improve the extraction efficiency of low-concentration lithium in oil and gas field water, the effects of Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, Br⁻, SO₄²⁻, NO₃⁻, and organic substances on the extraction efficiency of lithium were studied. The results showed that Na⁺ can promote the extraction of lithium to a certain extent, and lithium ions competed with K+ for extraction; however, the separation coefficient remained more than 13. Ca²⁺ and Mg²⁺ have a significant influence on the extraction of lithium and should be removed prior to extraction. Cl⁻, SO₄²⁻, and NO₃⁻ have little influence on the extraction solution of lithium. Among the organic components, a high concentration of long-chain alkane has a certain effect on the extraction efficiency of lithium, while other substances have little effect. On this basis, the first step for precipitating impurity ions and the second step for solvent extraction of lithium were established. After removing the impurity ions, the extraction efficiency of lithium can reach over 90%. Taking 15L of oil and gas field water as the research object, after extraction, back extraction, concentration, depth impurities removal by extraction, and precipitation drying, the purity of the lithium carbonate product can be achieved at 99.28%. This study can provide technical support for the efficient extraction of low-concentration lithium from oil and gas field water. Full article

The objective of this study was to develop a novel sauce formulation in which egg yolk was substituted with pea and soy proteins, in addition to the incorporation of tomato pomace as a functional ingredient. Nine experimental samples (E1–E3, S1–S3, and P1–P3) and three control samples (E0, S0, and P0) were prepared, corresponding to three protein sources (E: egg yolk, S: soy, P: pea), with increasing concentrations of tomato pomace (0, 2, 4, and 6%). The formulations were adjusted proportionally in terms of water and oil to maintain the desired consistency. The analyses performed included: physico-chemical analysis of the sauce (fat content, peroxide value, and CIE L* a* b* color determination), quality assessment using Fourier Transform Infrared Spectroscopy (FT-IR, rheological measurements, and microstructural evaluation. The sample designated P2 demonstrated a notable correlation with favourable parameters, exhibiting intense colouration, elevated protein content, and consistent rheological properties. However, at higher levels of tomato pomace (notably 6%), microstructural instability was observed, which may limit the formulation’s robustness over time. These findings demonstrate that tomato pomace can enhance the functional and structural characteristics of sauce, while also highlighting the importance of optimizing concentration levels to avoid negative impacts on emulsion stability. Overall, the results support the use of tomato pomace and plant proteins in the formulation of sustainable and innovative food products. Full article

In today’s industrial applications, cutting fluids have attained prime importance due to their all-round features, including increase of tool life by lubrication of the tool at the tool–workpiece interface. This study compares the effects of mango seed oil and pongamia oil on cutting force and surface morphology during the turning of AISI 304 steel. The design of experiments was applied using Taguchi’s method with an L9 array of experiments. During the experiment, it was discovered that mango seed and pongamia-based cutting fluid exhibited the lowest contact angles of 22.1° and 24.4°, respectively, at a 97:3 volumetric concentration of deionized water and eco-friendly oil. The use of mango seed oil as a cutting fluid with MQL (Minimum Quantity Lubrication) resulted in the lowest surface roughness of 0.809 µm, compared to 0.921 µm with pongamia-based cutting fluid. The cutting force was reduced by a maximum of 28.68% using mango seed-based cutting fluid, compared to pongamia-based cutting fluid. ANOVA analysis revealed that feed rate had the maximum influence on the optimization of output parameters for mango seed cutting fluid. For pongamia-based cutting fluid, feed rate had the maximum influence on cutting force, while the depth of cut had the strongest influence on surface roughness. Full article

Polymer flooding is a widely used enhanced oil recovery (EOR) method for improving energy efficiency and reducing the carbon footprint of oil production. Optimizing polymer concentration is critical for maximizing recovery while minimizing economic and environmental costs. Here, we present a systematic experimental study which shows that even very low concentrations of polymers yield relatively high recovery rates at adverse mobility ratios (230 cP oil). A series of core flood experiments were conducted on Bentheimer sandstone rock, with polymer concentrations ranging from 40 ppm (1.35 cP) to 600 ppm (10.0 cP). Beyond a mobility ratio threshold, increasing polymer concentration did not significantly enhance recovery. This plateau in performance was attributed to the persistence of viscous fingering and oil crossflow into pre-established water channels. The study suggests that low concentrations of polymer may mobilize oil at high mobility ratios by making use of the pre-established water channels as transport paths for the oil and that the rheology of the polymer enhances this effect. These findings enable reductions in the polymer concentration in fields with adverse mobility ratios, leading to substantial reductions in chemical usage, energy consumption, and environmental impact of the extraction process. Full article

This study focuses on the optimization of valve assemblies in downhole rod pumping units (DRPUs), which remain the predominant artificial lift technology in oil production worldwide. The research addresses the critical issue of premature failures in DRPUs caused by leakage in valve pairs, i.e., a problem that accounts for approximately 15% of all failures, as identified in a statistical analysis of the 2022 operational data from the Uzen oilfield in Kazakhstan. The leakage is primarily attributed to the accumulation of mechanical impurities and paraffin deposits between the valve ball and seat, leading to concentrated surface wear and compromised sealing. To mitigate this issue, a novel valve assembly design was developed featuring a flow turbulizer positioned beneath the valve seat. The turbulizer generates controlled vortex motion in the fluid flow, which increases the rotational frequency of the valve ball during operation. This motion promotes more uniform wear across the contact surfaces and reduces the risk of localized degradation. The turbulizers were manufactured using additive FDM technology, and several design variants were tested in a full-scale laboratory setup simulating downhole conditions. Experimental results revealed that the most effective configuration was a spiral plate turbulizer with a 7.5 mm width, installed without axis deviation from the vertical, which achieved the highest ball rotation frequency and enhanced lapping effect between the ball and the seat. Subsequent field trials using valves with duralumin-based turbulizers demonstrated increased operational lifespans compared to standard valves, confirming the viability of the proposed solution. However, cases of abrasive wear were observed under conditions of high mechanical impurity concentration, indicating the need for more durable materials. To address this, the study recommends transitioning to 316 L stainless steel for turbulizer fabrication due to its superior tensile strength, corrosion resistance, and wear resistance. Implementing this design improvement can significantly reduce maintenance intervals, improve pump reliability, and lower operating costs in mature oilfields with high water cut and solid content. The findings of this research contribute to the broader efforts in petroleum engineering to enhance the longevity and performance of artificial lift systems through targeted mechanical design improvements and material innovation. Full article

This study explored the potential of chitosan (CH)/bacterial cellulose (BC) complexes (0.5% w/v) as novel emulsifiers to stabilize oil-in-water (o/w) Pickering emulsions (20% v/v sunflower oil), with a focus on their gel-like behavior. Emulsions were prepared using CH combined with BNC derived via H₂SO₄ (BNC1) or H₂SO₄-HCl (BNC2) hydrolysis. Increasing BNC content improved stability by reducing phase separation and enhancing viscosity, while CH contributed interfacial activity and electrostatic stabilization. CH/BNC1_25:75 emulsions showed the highest stability, maintaining an emulsion stability index (ESI) of up to 100% after 3 days, with minimal change in droplet size (R_h ~8.5–8.8 μm) and a positive ζ-potential (15.1–29.8 mV), as confirmed by dynamic/electrophoretic light scattering. pH adjustment to 4 and 10 had little effect on their ESI, while ionic strength studies showed that 0.1 M NaCl caused only a slight increase in droplet size combined with the highest ζ-potential (−35.2 mV). Higher salt concentrations led to coalescence and disruption of their gel-like structure. Rheological analysis of CH/BNC1_25:75 emulsions revealed shear-thinning behavior and dominant elastic properties (G′ > G″), indicating a soft gel network. Incorporating sunflower-seed protein isolates into CH/BNC1 (25:75) emulsions led to coacervate formation (three-layer system), characterized by a decrease in droplet size and an increase in ζ-potential (up to 32.8 mV) over 7 days. These findings highlight CH/BNC complexes as sustainable stabilizers for food-grade Pickering emulsions, supporting the development of biopolymer-based emulsifiers aligned with bioeconomy principles. Full article

A high intake of saturated fats and cholesterol from processed meats is associated with increased cardiovascular disease risk. This study aimed to develop a nutritionally enhanced Bologna-type sausage by partially replacing the beef content with a structured emulsion gel (EG) formulated from pine nut oil, inulin, carrageenan, and whey protein concentrate. The objective was to improve its lipid quality and functional performance while maintaining product integrity and consumer acceptability. Three sausage formulations were prepared: a control and two variants with 7% and 10% EG, which substituted for the beef content. The emulsion gel was characterized regarding its physical and thermal stability. Sausages were evaluated for their proximate composition, fatty acid profile, cholesterol content, pH, cooking yield, water-holding capacity, emulsion stability, instrumental texture, microstructure (via SEM), oxidative stability (TBARSs), and sensory attributes. Data were analyzed using a one-way and two-way ANOVA with Duncan’s test (p < 0.05). The EG’s inclusion significantly reduced the total and saturated fat and cholesterol, while increasing protein and unsaturated fatty acids. The 10% EG sample achieved a PUFA/SFA ratio of 1.00 and an over 80% reduction in atherogenic and thrombogenic indices. Functional improvements were observed in emulsion stability, cooking yield, and water retention. Textural and visual characteristics remained within acceptable sensory thresholds. SEM images showed more homogenous matrix structures in the EG samples. TBARS values increased slightly over 18 days of refrigeration but remained below rancidity thresholds. This period was considered a pilot-scale evaluation of oxidative trends. Sensory testing confirmed that product acceptability was not negatively affected. The partial substitution of beef content with pine nut oil-based emulsion gel offers a clean-label strategy to enhance the nutritional quality of Bologna-type sausages while preserving functional and sensory performance. This approach may support the development of health-conscious processed meat products aligned with consumer and regulatory demands. Full article

Date seeds, a by-product of the pitted-date industry, are often discarded as waste. This study investigated the interaction between date seed powder and starch at different concentrations (0, 1, 5, 10, and 20 g/25 g composite) and temperatures (40 °C and 70 °C). The results revealed that the hygroscopicity of date seed powder (9.94 g/100 g) was lower than starch (13.39 g/100 g), and its water absorption (75.8%) was also lower than starch (88.3%), leading to a reduced absorbance capacity in composites. However, the solubility increased with a higher date seed content due to its greater solubility (17.8 g/L) compared to starch (1.6 g/L). A morphological analysis showed rough, agglomerated particles in date seed powder, while starch had smooth, spherical shapes. This study also found that the composites formed larger particles at 40 °C and porous structures at 70 °C. Crystallinity decreased from 41.6% to 12.8% (40 °C) and from 24.0% to 11.3% (70 °C). A thermal analysis revealed three endothermic peaks (glass transitions and solid melting), with an additional oil-melting peak in high-seed samples. FTIR spectra showed changes in peak intensities and locations upon seed incorporation. Overall, these findings revealed that, the incorporation of date seed powder–starch composites into bakery formulations offers a promising strategy for developing fiber-enriched products, positioning them as functional ingredients with added nutritional value. Full article