Search Results (385)

In order to study the problem of obvious wall thinning in the wellbore caused by proppant backflow and sand production under throttling conditions in tight gas wells. Based on the gas-phase control equation, particle motion equation, and erosion model, the wellbore erosion model is established. The distribution law of pressure, temperature, and velocity trace fields under throttling conditions is analyzed, and the influences of different throttling pressures, particle diameters, and particle mass flows on wellbore erosion are analyzed. The flow field at the nozzle changes drastically, and there is an obvious pressure drop, temperature drop, and velocity rise. When the surrounding gas is completely mixed, the physical quantity gradually stabilizes. The erosion shape of the wellbore outlet wall has a point-like distribution. The closer to the throttle valve outlet, the more intense the erosion point distribution is. Increasing the inlet pressure and particle mass flow rate will increase the maximum erosion rate, and increasing the particle diameter will reduce the maximum erosion rate. The particle mass flow rate has the greatest impact on the maximum erosion rate, followed by the particle diameter. The erosion trend was predicted using multiple regression model fitting of the linear interaction term. The research results can provide a reference for the application of downhole throttling technology and wellbore integrity in tight gas exploitation. Full article

Drought conditions impact plants at the morphological, physiological, and molecular levels. Plant tolerance to drought conditions is frequently associated with maintaining proteome stability, highlighting the significance of proteomic analysis in understanding the mechanisms underlying plant resilience. Here, we performed proteomic and peptidomic analysis of spring wheat (Triticum aestivum L.) under drought stress conditions. Using isobaric tags for relative and absolute quantitation (iTRAQ), we identified 497 and 157 differentially abundant protein (DAP) groups in leaves and roots, respectively. The upregulated DAP groups in leaves were primarily involved in stress responses, such as oxidative stress and heat response, whereas those in roots were associated with responses to water deprivation and sulfur compound metabolic processes. The analysis of the extracellular root peptidome revealed 2294 native peptides, including members of small secreted peptide (SSP) families. In the peptidomes of stress-induced plants, we identified 16 SSPs as well as peptides derived from proteins involved in cell wall catabolism, intercellular signaling, and stress response. These peptides represent potential candidates as regulators of drought responses. Our results help us to understand adaptation mechanisms and develop new agricultural technologies to increase productivity. Full article

Construction costs have increased significantly since the COVID-19 pandemic due to supply chain disruption, labour shortages, and construction material price hikes. The market is increasingly demanding innovative construction methods that can save construction costs, reduce construction time, and minimise waste and carbon emission. The prefabrication system has been used for years in industrial construction, resulting in better performance in regard to structure stability, the control of wastage, and the optimisation of construction time and cost. In addition, prefabrication has had a positive contribution on resource utilisation in the construction industry. There are various types of prefabricated wall systems. However, the majority of comparative studies have focused on comparing each prefabrication wall system against the conventional construction system, while limited research has been conducted to compare different prefabrication structures. This study examined four prominent prefabricated wall systems, i.e., precast walls, tilt-up walls, prefabricated steel-frame walls, and on-site-cut steel-frame walls, to determine which one is more suitable for the construction of industrial buildings to minimise cost, time delay, and labourer utilisation on construction sites, as well as to enhance structure durability, construction efficiency, and sustainability. One primary case project and five additional projects were included in this study. For the primary case project, data were collected and analysed; for example, a subcontractor cost comparison for supply and installation was conducted, and shop drawings, construction procedures, timelines, and site photos were collected. For the additional five projects, the overall cost data were compared. The main research finding of this study is that factory-made precast walls and tilt-up wall panels require similar construction time. However, on average, tilt-up prefabrication construction can reduce the cost by around 23.55%. It was also found that prefabricated frame walls provide cost and time savings of around 39% and 10.5%, respectively. These findings can provide architects, developers, builders, suppliers, regulators, and other stakeholders with a comprehensive insight into selecting a method of wall construction that can achieve greater efficiency, cost savings, and environmental sustainability in the construction of industrial and commercial buildings. Full article

Background/Objectives: In recent years, increasing attention has been paid to the stabilization of natural biologically active compounds in order to expand their application in the food, pharmaceutical, and cosmetic industries. Such compounds, such as polyphenols, essential fatty acids, or vitamins, are extremely sensitive to environmental factors. This study aims to review the spray-drying-based microencapsulation technology and its application for stabilizing sensitive biologically active substances. Methods: This article systematically analyzes the main steps of the spray-drying microencapsulation process and discusses traditional and innovative wall materials, including natural polymers (polysaccharides and proteins), as well as new raw material sources (e.g., yeast cells, canola and pea protein isolates, and hemicelluloses). It also examines the potential of these systems for the stimulated release of active ingredients. Results: This review provides a comprehensive overview of the main stages of the spray-drying process and critically examines both conventional (e.g., maltodextrin and gum Arabic) and innovative wall materials (e.g., plant-based proteins and food industry by-products). Studies show that using different wall materials can achieve high encapsulation efficiency, improve the stability of biologically active substances, and control their release. Various compounds have been successfully microencapsulated—polyphenols, essential oils, carotenoids, fatty acids, and vitamins—protecting them from oxidation, light, and temperature. The review identifies key factors that can enhance product quality, increase encapsulation yield, and reduce processing costs and energy input—offering meaningful insights for optimizing the microencapsulation process. Conclusions: Spray-drying-based microencapsulation is an advanced technology that effectively protects sensitive active ingredients and allows for wider industrial food, pharmaceutical, and cosmetic applications. In the future, more attention is expected to be paid to personalized formulations, stimulated release systems, and sustainable wall materials from by-products. Full article

New types of functional peanut butter containing the probiotic strain Bacillus coagulans TBC-169 and Bacillus coagulans microcapsules with different wall materials were developed. After 24 h of in vitro simulated digestion, the peanut butter with high-ester pectin (group A) and inulin (group B) microcapsules still retained 5.94 ± 0.58 × 10⁸ and 1.79 ± 0.73 × 10⁹ CFU/g of Bacillus coagulans, respectively. Both the high-ester pectin and inulin microcapsules could be well preserved in the peanut butter substrate and stored at 4 °C and 25 °C for 120 days. The biological activities of B. coagulans in the two groups were 2.64 ± 0.58 × 10¹⁰ and 2.31 ± 0.4 × 10¹¹ CFU/g, and 5.20 ± 0.10 × 10⁸ and 2.24 ± 0.11 × 10⁹ CFU/g, respectively. The addition of microcapsules improved the texture, stability, and rheological properties of the peanut butter. Differential scanning calorimetry revealed that the microcapsules showed certain binding interactions with the oil and proteins in the peanut butter. The rheological and texture tests demonstrated an improved ductility and reduced hardness and viscosity after the microcapsule addition. Targeted metabolomics identified inulin as a synergistic substrate for Bacillus coagulans in the probiotic peanut butter, which enhanced the functionality and stability of the microencapsulated probiotics. This study delivered essential information and parameters for the preparation of probiotic microcapsule peanut butter and laid the foundation for future research efforts geared toward the formulation, preparation, and characterization of functional peanut butter. Full article

The shallow, soft subsea formations, characterized by low strength and poor stability, lead to complex interactions between the screw motor drilling tool and the wellbore wall during directional drilling, complicating the accurate evaluation of the tool’s deflection capability. To address this issue, this paper proposes an integrated mechanical analysis method combining three-dimensional finite element analysis and transient dynamic analysis. By establishing a finite element model using 12-DOF (degree-of-freedom) spatial rigid-frame Euler–Bernoulli beam elements, coupled with well trajectory coordinate transformation and Rayleigh damping matrix, a precise description of drill string dynamic behavior is achieved. Furthermore, the introduction of pipe–soil dynamics and the p-y curve method improves the calculation of contact reaction forces between drilling tools and formation. Case studies demonstrate that increasing the tool face rotation angle intensifies lateral forces at the bit and stabilizer, with the predicted maximum dogleg severity within the first 10 m ahead of the bit progressively increasing. When the tool face rotation angle exceeds 2.5°, the maximum dogleg severity reaches 17.938°/30 m. With a gradual increase in the drilling pressure, the maximum bending stress on the drilling tool, maximum lateral cutting force, and stabilizer lateral forces progressively decrease, while vertical cutting forces and bit lateral forces gradually increase. However, the predicted maximum dogleg severity increases within the first 10 m ahead of the bit remain relatively moderate, suggesting the necessity for the multi-objective optimization of drilling pressure and related parameters prior to actual operations. Full article

A biosensor for the determination of glucose, lactate, ethanol and starch in beverages has been developed using enzymes immobilized by a redox-active gel on a screen-printed electrode. A significant improvement proposed for multichannel biosensors, overcoming stability and sensitivity issues by covalently binding phenazine mediators to a biocompatible protein hydrogel, enhancing the packaging of the enzyme. Glucose oxidase (GOx), alcohol oxidase (AOx) and lactate oxidase (LOx) were used as biological materials, as well as a mixture of GOx with γ-amylase (Am). Redox gels were synthesized from bovine serum albumin (BSA) and phenazine derivatives. It was shown that a neutral red-based redox gel combined with single-walled carbon nanotubes is more promising than other substrates for enzyme immobilization. The lower limit of quantification for glucose, ethanol, lactate and starch using these systems is 0.035 mM, 2.3 mM, 15 mM and 2 mg/L, respectively. Biosensors were used to analyze the content of these substances in alcoholic, kvass and fermentation mass. Statistical analysis of the results showed that the values of glucose, ethanol, lactic acid and starch determined using biosensors and obtained by reference methods differ insignificantly. A set of biosensors developed on the basis of specifically selected enzymes is effective for controlling biotechnological processes and can be used as an alternative to classical analytical methods. Full article

During the drilling process of high-temperature geothermal wells, the high temperature at the bottom of the well and the complex lithology of the formation lead to poor tooth loss prevention in cone drill bits. This issue seriously affects the life and efficiency of geothermal drilling. The stability of the wellbore is one of the key issues in the drilling process of high-temperature geothermal wells, and the fixed-tooth strength of the roller drill bit directly affects the stability of the wellbore and drilling efficiency. The heat transfer effect of the wellbore will exacerbate the thermal expansion and performance degradation of the drill bit material in high-temperature environments, leading to a decrease in the strength of the fixed teeth. To address this, this study used a high-temperature experimental apparatus to systematically test the fixed-tooth strength of roller drill bits. By using five types of tooth spacing: 4, 6, 8, 10, and 12 mm, three types of tooth diameters: 12, 14, and 16 mm, and three types of interference fit: 0.075, 0.095, and 0.115 mm, the maximum fastening force of fixed teeth was measured under different conditions, and its variation pattern was analyzed. The experimental results show that the higher the temperature, the weaker the tooth-fixing strength. Under the same perforation distance, the maximum fastening force decreases with increasing temperature. Compared with normal temperature, the maximum fastening force decreases by about 49.6–64.5%. At the same temperature, the maximum fastening force is the largest when the perforation distance is 10 mm. When the temperature increases, the maximum fastening force increases with the tooth diameter; that is, the larger the tooth diameter, the better the tooth-fixing effect. At the same temperature, the maximum fastening force first increases and then decreases with increasing interference. The maximum fastening force is the largest when the interference is 0.095 mm. At 120 °C, 180 °C, and 240 °C, the maximum fastening force is reduced by 21.9%, 29.4%, and 56.6%, respectively, compared to normal temperature. The study reveals the variation law of tooth-fixing strength under high-temperature conditions and proposes tooth-fixing methods and suggestions suitable for high-temperature geothermal wells. This provides a scientific basis for solving the problem of tooth loss of roller bits in high-temperature geothermal drilling and has important theoretical and practical application value. Full article

Identifying sustainable and efficient methods for the degradation of plastic waste in landfills is critical for the implementation of the Saudi Green Initiative, the European Union’s Strategic Plan, and the 2030 United Nations Action Plan, all of which are aimed at achieving a sustainable environment. This study assesses the influence of palm fronds (PFR) on the thermal degradation of polypropylene plastic (PP) using TGA/FTIR experimental measurements, thermo-kinetics, and machine learning convolutional deep learning neural networks (CDNN). Thermal degradation operations were conducted on pure materials (PFR and PP) as well as mixed (blended) materials containing 25% and 50% PFR, across degradation temperatures ranging from 25 to 600 °C and heating rates of 10, 20, and 40 °C·min⁻¹. The TGA data indicated a synergistic interaction between the agricultural waste (PFR) and PP plastic, with decreased thermal stability at temperatures below 500 °C, attributed to the hemicellulose and cellulose present in the PFR biomass. In contrast, at temperatures exceeding 500 °C, the presence of lignin retards the degradation of the PFR biomass and blends. Activation energy values between 81.92 and 299.34 kJ·mol⁻¹ were obtained through the application of the Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) model-free methods. The application of CDNN facilitated the extraction of significant features and labels, which were crucial for enhancing modeling accuracy and convergence. This modeling and simulation approach reduced the overall cost function from 41.68 to 0.27, utilizing seven hidden neurons, and 673,910 epochs in 13.28 h. This method effectively bridged the gap between modeling and experimental data, achieving an R² value of approximately 0.992, and identified sample composition as the most critical parameter influencing the thermolysis process. It is hoped that such findings may facilitate an energy-efficient pathway necessary for the thermal decomposition of plastic materials in landfills. Full article

A well-designed clamping layout significantly enhances the dynamic stiffness of a manufacturing system, improving its stability and suppressing cutting chatter in workpieces. This paper focuses on the machining of thin-walled beams, which are prone to vibration and have low stiffness, especially under hydraulic floating clamping conditions. By analyzing the system stability domain, we propose a method to improve system stiffness through strategic design of support module layouts. Finite element dynamic simulations and modal hammer experiments were conducted to validate this approach. The results show that the proposed layout design method increases the relative central frequency by 13.49% and the relative fundamental frequency by 8.51%. These findings demonstrate a substantial improvement in the dynamic stiffness of the part-clamping system, confirming that the auxiliary support module layout design method effectively enhances system dynamic stiffness and suppresses cutting chatter. Full article

Yeasts have been extensively recognized as a type of model microorganism due to their facile cultivation, short growth cycle, and genetic stability. Different yeast strains, such as Saccharomyces cerevisiae and Rhodotorula mucilaginosa, have exhibited notable sorption capacities for heavy metals and metalloids. Yeast employs diverse pathways for detoxifying heavy metals via its cell walls, intracellular organelles, and extracellular polymeric substances (EPSs). The cell wall has many functional groups to adsorb metals, decreasing their concentrations in the environment. In intracellular regions, some proteins are capable of transporting metals into biological metabolic processes for detoxification. In extracellular regions, electrostatic as well as complexation mechanisms between protein in EPSs and heavy metals is well accepted. Meanwhile, mannose and glucose within EPSs are target sugars for complexation with metals. Many yeasts can hence work as excellent biomaterials for the bioremediation of metal pollution. Meanwhile, they can be combined with other materials to enhance remediation efficiency. This study reviews underlying mechanisms and cases of yeast-mediated metal detoxification, alongside highlighting yeasts’ industrial applications as bioremediation materials. Full article

Guayule (Parthenium argentatum A. Gray) is a valuable domestic source for rubber and resin. At its center of origin in the Northern Mexico and Southern Texas deserts, guayule, a perennial shrub, is hybridized with its relative species mariola (Parthenium incanum Kunth). As rubber and resin are the main products derived from guayule, there is interest in using guayule bagasse as a bioenergy feedstock to meet the growing bioenergy and biofuel demands. This study aimed to explore and characterize phenotypic diversity in cell wall constituents (lignin, cellulose, and hemicellulose) and their yields among 51 guayule and mariola genotypes under two irrigation regimes (well-watered and water-stressed). Significant genotypic and environmental effects were observed for lignin, cellulose and hemicellulose concentrations, and yields, indicating the wide genetic variability of the collection for bioenergy-related traits. Moderate to high entry-mean heritability values for lignin, cellulose, and hemicellulose suggest that selection is feasible to enhance genetic gain. Significant positive correlations were found among cellulose and hemicellulose concentrations and yields, indicating the possibility to select multiple traits together during breeding cycles. High positive correlations between rubber and resin and lignin, cellulose, and hemicellulose yields highlight the opportunity to develop guayule germplasm with enhanced multi-use traits for industrial applications. Wide variations in drought stress indices (stress tolerance index, yield index, and yield stability index) underscore the environmental impact on the lignocellulosic traits. Several genotypes were identified with high stress index scores and could be parental candidates for improving guayule for arid and semi-arid sustainable agricultural systems. The current study is the first to characterize the phenotypic diversities in guayule and mariola for lignocellulosic components and yield, providing the foundation for future breeding efforts aimed at enhancing guayule’s value for diverse production goals and environmental conditions. Full article

Graphene quantum dots (GQDs) show significant promise as antibacterial agents, but their application is hindered by several limitations, including potential cytotoxicity at high concentrations, as well as concerns regarding aggregation and reusability. In this study, sodium titanate (NTO) ultralong nanotubes were utilized as both a photocatalyst and support for GQDs. The NTO/GQDs heterojunction was formed by embedding GQDs nanoplates onto the walls of NTO nanotubes. This integration significantly improved the visible light absorption and enhanced the separation and transfer of electron–hole pairs, leading to an efficient photocatalytic antibacterial process. The NTO/GQD-8 self-supporting membrane composed of these ultralong nanotubes demonstrated outstanding antibacterial efficiency (99.99%) against E. coli and exhibited remarkable cycling stability. Radical scavenging experiments revealed that ∙OH and e⁻ were the primary reactive species driving the photocatalytic antibacterial process. Notably, NTO and NTO/GQDs-8 exhibited distinct antibacterial outcomes. After photocatalytic treatment with NTO/GQDs-8, E. coli cells were completely fragmented, with no intact cell structures remaining due to the synergy effect of GQDs’ physical cutting during photocatalytic treatment. Full article

Hypercholesterolemia causes atherosclerosis by inducing immune cell migration and chronic inflammation in arterial walls. Recent single-cell analyses reveal the presence of lipid-enriched foamy macrophages, as well as other macrophage subtypes, neutrophils, T cells, and B cells, in atherosclerotic plaques in both animal models and humans. These cells interact with each other and other cells, including non-immune cells such as endothelial cells and smooth muscle cells. They thereby regulate metabolic, inflammatory, phagocytic, and cell death processes, thus affecting the progression and stability of atherosclerotic plaques. The nuclear receptors liver X receptor (LXR)α and LXRβ are transcription factors that are activated by oxysterols and regulate lipid metabolism and immune responses. LXRs regulate cholesterol homeostasis by controlling cholesterol’s transport, absorption, synthesis, and breakdown in the liver and intestine. LXRs are also highly expressed in tissue-resident and monocyte-derived macrophages and other immune cells, including both myeloid cells and lymphocytes, and they regulate both innate and adaptive immune responses. Interestingly, LXRs have immunosuppressive and immunoregulatory functions that are cell-type-dependent. In animal models of atherosclerosis, LXRs have been shown to be involved in both progression and regression phases. The pharmacological activation of LXR enhances cholesterol efflux from macrophages and promotes atherosclerosis progression. Deleting LXR in immune cells, especially myeloid cells, accelerates atherosclerosis by increasing monocyte migration, macrophage proliferation and activation, and neutrophil extracellular traps (NETs); furthermore, the deletion of hematopoietic LXRs impairs the regression of atherosclerotic plaques. Therefore, LXRs in immune cells may be a potent therapeutic target for atherosclerosis. Full article

A transient stability flow analysis is performed using the unsteady laminar boundary layer equations. The flow dynamics are studied via the Navier–Stokes equations. In the case of external spatially developing flow, the differential equations are reduced via Prandtl or boundary-layer assumptions, consisting of continuity and momentum conservation equations. Prescription of streamwise pressure gradients (decelerating and accelerating flows) is carried out by an impulsively started Falkner–Skan (FS) or wedge-flow similarity flow solution in the case of flat plate or a Blasius solution for particular zero-pressure gradient case. The obtained mean streamwise velocity and its derivatives from FS flows are then inserted into the well-known Orr–Sommerfeld equation of small disturbances at different dimensionless times ($\tau$). Finally, the corresponding eigenvalues are dynamically computed for temporal stability analysis. A finite difference algorithm is effectively applied to solve the Orr–Sommerfeld equations. It is observed that flow acceleration or favorable pressure gradients (FPGs) lead to a significantly shorter transient period before reaching steady-state conditions, as the developed shear layer is notably thinner compared to cases with adverse pressure gradients (APGs). During the transient phase (i.e., for $\tau <1$), the majority of the flow modifications are confined to the innermost 20–25% of the boundary layer, in proximity to the wall. In the context of temporal flow stability, the magnitude of the pressure gradient is pivotal in determining the streamwise extent of the Tollmien–Schlichting (TS) waves. In highly accelerated laminar flows, these waves experience considerable elongation. Conversely, under the influence of a strong adverse pressure gradient, the characteristic streamwise length of the smallest unstable wavelength, which is necessary for destabilization via TS waves, is significantly reduced. Furthermore, flows subjected to acceleration ($\beta$ > 0) exhibit a higher propensity to transition towards a more stable state during the initial transient phase. For instance, the time response required to reach the steady-state critical Reynolds number was approximately 1$\tau$ for $\beta$ = 0.18 (FPG) and $\tau$ = 6.8 for $\beta$ = −0.18 (APG). Full article