Search Results (523)

Downhole kick is one of the most severe safety hazards in deep and ultra-deep well drilling operations. Traditional monitoring methods, which rely on surface flow rate and fluid level changes, are limited by their delayed response and insufficient sensitivity, making them inadequate for early warning. This study proposes a real-time monitoring technique for gas content in drilling fluid based on the attenuation principle of Ba-133 γ-rays. By integrating laboratory static/dynamic experiments and Geant4-11.2 Monte Carlo simulations, the influence mechanism of gas–liquid two-phase media on γ-ray transmission characteristics is systematically elucidated. Firstly, through a comparative analysis of radioactive source parameters such as Am-241 and Cs-137, Ba-133 (main peak at 356 keV, half-life of 10.6 years) is identified as the optimal downhole nuclear measurement source based on a comparative analysis of penetration capability, detection efficiency, and regulatory compliance. Compared to alternative sources, Ba-133 provides an optimal energy range for detecting drilling fluid density variations, while also meeting exemption activity limits (1 × 10⁶ Bq) for field deployment. Subsequently, an experimental setup with drilling fluids of varying densities (1.2–1.8 g/cm³) is constructed to quantify the inverse square attenuation relationship between source-to-detector distance and counting rate, and to acquire counting data over the full gas content range (0–100%). The Monte Carlo simulation results exhibit a mean relative error of 5.01% compared to the experimental data, validating the physical correctness of the model. On this basis, a nonlinear inversion model coupling a first-order density term with a cubic gas content term is proposed, achieving a mean absolute percentage error of 2.3% across the full range and R² = 0.999. Geant4-based simulation validation demonstrates that this technique can achieve a measurement accuracy of ±2.5% for gas content within the range of 0–100% (at a 95% confidence interval). The anticipated field accuracy of ±5% is estimated by accounting for additional uncertainties due to temperature effects, vibration, and mud composition variations under downhole conditions, significantly outperforming current surface monitoring methods. This enables the high-frequency, high-precision early detection of kick events during the shut-in period. The present study provides both theoretical and technical support for the engineering application of nuclear measurement techniques in well control safety. Full article

Separating azeotropes is an important, difficult, and expensive task, in particular for the 2-propanol–water mixture. The literature on the problem is rich in modeling studies but often lacking even the simplest experimental confirmation. In this paper, extractive distillation, liquid–liquid equilibrium-based extraction, and salting-out were experimentally tested for the desired separation. Among the four tested extractive distillation entrainers, none was able—in the investigated experimental setup—to push the system over the azeotropic composition threshold. Four novel hydrophobic deep eutectic extraction media were tested for the desired separation, and those based on menthol or thymol with decanoic acid were found most promising. Among 16 tested salting-out agents, 5 of them produced two-liquid phases, and only 4 hydrophilic inorganic salts promoted 2-propanol separation, with sodium carbonate being the most promising candidate. The purity of the products was tested with FTIR and ¹H-NMR. The experimental findings were compared with COSMO-RS model predictions, with moderate success. Full article

This article provides a comprehensive review of gas flow behavior in low-permeability geological media, focusing on its implications for the long-term performance of engineered barriers in underground radioactive waste repositories. Key mechanisms include two-phase flow and gas-driven fracturing, both critical for assessing repository safety. Understanding the generation and migration of gas is crucial for the quantitative assessment of repository performance over extended timescales. The article synthesizes the current research on various types of claystone considered as potential host rocks for repositories, providing a comprehensive analysis of gas transport mechanisms and constitutive models. In addressing the challenges related to multi-field coupling, the article provides practical insights and outlines potential solutions and areas for further research, underscoring the importance of interdisciplinary collaboration to tackle these challenges and push the field forward. In addition, the article evaluates key research projects, such as GMT, FORGE, and DECOVALEX, shedding light on their methodologies, findings, and significant contributions to understanding gas migration in low-permeability geological media. In this context, mathematical modeling becomes indispensable for predicting long-term repository performance under hypothetical future conditions, enhancing prediction accuracy and supporting long-term safety assessments. Finally, the growing interest in gas-driven fracturing is explored, critically assessing the strengths and limitations of current numerical simulation tools, such as TOUGH, the phase-field method, and CODE_BRIGHT. Noteworthy advancements by the CODE_BRIGHT team in gas injection simulation are highlighted, although knowledge gaps remain. The article concludes with a call for innovative approaches to simulate gas fracturing processes more effectively, advocating for advanced modeling techniques and rigorous experimental validation to address existing challenges. Full article

Based on admirable porous media performance and the popularity of additive manufacturing technology, gradient porous media are progressively being applied in increasing fields. In this study, convection heat transfer within a square vented cavity, partially occupied by two copper metal foam layers of $10$ and $20$ PPI saturated with nanofluid, was assessed numerically. The left wall was heated uniformly and non-uniformly by applying multi-frequency spatial heating following a sinusoidal function. Governing equations, including continuity, the Darcy–Brinkmann–Forchheimer model, and local thermal non-equilibrium energy equations, were adopted and solved by employing the finite volume method. The influences of relevant parameters, including nanoparticle concentrations $\left(0\%\le \phi \le 10\%\right)$, Reynolds number ($1\le Re\le 100$), inlet and outlet port aspect ratios $\left(0.1\le D/H\le 0.4\right)$, three outlet vent opening locations ($\left(S_o=0\right)$ left, ($S_o=\left(H/2-D/2\right)$) middle, and ($S_o=\left(H-D\right)$) right), sinusoidal offset temperature (${\theta }_o=0.5$, $1$), frequency ($f=1, 3, 5$), and amplitude ($A=0-1$), were examined. The results demonstrate that flow and heat transfer fields are impacted mainly by these parameters. Streamlines are more intensified at the upper-left corner when the outlet opening vent is shifted towards the right-corner upper wall. Fluid- and solid-phase Nusselt number increases $Re$, $D/H$, ${\theta }_o$, $A$, and $f$ are raised, specifically when $A\ge 0.3$. The Nusselt number remains constant when the frequency is raised from $3$ to $5$, definitely when $D/H\ge 0.25$. In uniform and non-uniform heating cases, the Nusselt number of both phases remains constant as the outlet port is shifted right for $Re\le 10$ and slightly for higher $Re$ as the outlet vent location is translated from left to right. Full article

Background and Objectives: Early detection of cognitive decline (CD) is crucial for managing dementia risk factors and preventing disease progression. This study pursues two main objectives: (1) to review existing cognitive screening practices implemented in community pharmacy settings and (2) to characterize the cognitive profile of individuals eligible for screening in this context. Materials and Methods: This study was conducted in two phases. First, a scoping review of cognitive screening tools used in community pharmacies was carried out following PRISMA-ScR guidelines. Second, a cross-sectional study was performed to design and implement a CD screening protocol, assessing cognitive function. Data collection included demographic and clinical variables commonly associated with dementia risk. Decision tree analysis was applied to identify key variables contributing to the cognitive profile of patients eligible for screening. Results: The scoping review revealed that screening approaches differed by country and population, with limited pharmacy involvement suggesting implementation barriers. Cognitive screening was conducted in 18 pharmacies in Valencia, Spain (1.45%), involving 286 regular users reporting Subjective Memory Complaints (SMC). The average age of participants was 71 years, and 74.8% were women. According to the unbiased Gini impurity index, the most relevant predictors of CD—based on the corrected mean decrease in corrected impurity (MDcI), a bias-adjusted measure of variable importance—were age (MDcI: 2.60), internet and social media use (MDcI: 2.43), sleep patterns (MDcI: 1.83), and educational attainment (MDcI: 0.96). Simple decision trees can reduce the need for full screening by 53.6% while maintaining an average sensitivity of 0.707. These factors are essential for defining the profile of individuals who would benefit most from CD screening services. Conclusions: Community pharmacy-based detection of CD shows potential, though its implementation remains limited by issues of consistency and feasibility. Enhancing early dementia detection in primary care settings may be achieved by prioritizing individuals with limited internet and social media use, irregular sleep patterns, and lower education levels. Targeting these groups could significantly improve the effectiveness of CD screening programs. Full article

Horizontal wells have revolutionized hydrocarbon production by enhancing recovery efficiency and reducing environmental impact. This paper presents an enhanced Black Oil Model simulator, written in Visual Basic, for three-dimensional two-phase (oil and water) flow through porous media. Unlike most existing tools, this simulator is customized for horizontal well modeling and calibrated using extensive historical data from the South Rumaila Oilfield, Iraq. The simulator first achieves a strong match with historical pressure data (1954–2004) using vertical wells, with an average deviation of less than 5% from observed pressures, and is then applied to forecast the performance of hypothetical horizontal wells (2008–2011). The results validate the simulator’s reliability in estimating bottom-hole pressure (e.g., ±3% accuracy for HRU1 well) and water–oil ratios (e.g., WOR reduction of 15% when increasing horizontal well length from 1000 m to 2000 m). Notably, the simulator demonstrated that doubling the horizontal well length reduced WOR by 15% while increasing bottom-hole pressure by only 2%, highlighting the efficiency of longer wells in mitigating water encroachment. This work contributes to improved reservoir management by enabling efficient well placement strategies and optimizing extraction planning, thereby promoting both economic and resource-efficient hydrocarbon recovery. Full article

In high-pressure thermal power systems, corrosion-induced wall thinning in steam pipelines poses a significant threat to operational safety and efficiency. This study investigates the effects of gas–liquid two-phase flow on corrosion-induced wall thinning in pipe bends of high-pressure heaters in power plants, with particular emphasis on the mechanisms of void fraction and inner wall surface roughness. Research reveals that an increased void fraction significantly enhances flow turbulence and centrifugal effects, resulting in elevated pressure and Discrete Phase Model (DPM) concentration at the bend, thereby intensifying erosion phenomena. Simultaneously, the turbulence generated by bubble collapse at the bend promotes the accumulation and detachment of corrosion products, maintaining a cyclic process of erosion and corrosion that accelerates wall thinning. Furthermore, the increased surface roughness of the inner bend wall exacerbates the corrosion process. The rough surface alters local flow characteristics, leading to changes in pressure distribution and DPM concentration accumulation points, subsequently accelerating corrosion progression. Energy-Dispersive Spectroscopy (EDS) and Scanning Electron Microscopy (SEM) analyses reveal changes in the chemical composition and microstructural characteristics of corrosion products. The results indicate that the porous structure of oxide films fails to effectively protect against corrosive media, while bubble impact forces damage the oxide films, exposing fresh metal surfaces and further accelerating the corrosion process. Comprehensive analysis demonstrates that the interaction between void fraction and surface roughness significantly intensifies wall thinning, particularly under conditions of high void fraction and high roughness, where pressure and DPM concentration at the bend may reach extreme values, further increasing corrosion risk. Therefore, optimization of void fraction and surface roughness, along with the application of corrosion-resistant materials and surface treatment technologies, should be considered in pipeline design and operation to mitigate corrosion risks. Full article

A continuous-wave (CW) orthogonally polarized single-wavelength red laser (OPSRL) at 698 nm with a tunable power ratio within a wide range between the two polarized components was demonstrated using two Pr³⁺:LiLuF₄ (Pr:LLF) crystals for the first time. Through control of the waist location of the pump beam in the active media, the output power ratio of the two polarized components of the OPSRL could be adjusted. Under pumping by a 20 W, 444 nm InGaN laser diode (LD), a maximum total output power of 4.12 W was achieved with equal powers for both polarized components, corresponding to an optical conversion efficiency of 23.8% relative to the absorbed pump power. Moreover, by a type-II critical phase-matched (CPM) BBO crystal, a CW ultraviolet (UV) second-harmonic generation (SHG) at 349 nm was also obtained with a maximum output power of 723 mW. OPSRLs can penetrate deep tissues and demonstrate polarization-controlled interactions, and are used in bio-sensing and industrial cutting with minimal thermal distortion, etc. The dual-polarized capability of OPSRLs also supports multi-channel imaging and high-speed interferometry. Full article

Background/Objectives: Increasing the solid-state landscape of an active pharmaceutical ingredient (API) by generating new crystalline forms (e.g., polymorphs, cyclodextrin (CD) inclusion complexes, co-crystals, and salts) can yield products with significantly enhanced biopharmaceutical properties (especially increased water solubility), thereby improving API delivery and extending its lifetime. The aim of this study was the isolation of new solid forms of the poorly water-soluble non-steroidal anti-inflammatory drug fenbufen (FBF), for which relatively few solid phases have been reported to date. Further motivation for the study is the recent finding that it has potential for repurposing to treat acute pancreatitis. Methods: Interventions for generating new solid forms of FBF included (a) polymorph screening with a variety of solvent media, (b) attempts to form solid inclusion complexes with the native cyclodextrins α-, β-, and γ-CD using various preparative methods, and (c) co-crystallization with a series of coformers to produce co-crystals and/or molecular salts. Results: No new polymorphic forms of FBF were identified, but screening with CDs resulted in isolation and characterization of a new solid inclusion complex with γ-CD. However, co-crystallization of FBF with the water-soluble coformer isonicotinamide yielded two new products, namely a 1:1 co-crystal and an unusual multi-component ionic co-crystal, whose aqueous solubility indicated significant enhancement of FBF solubility. Conclusions: Due to its extremely low water solubility, FBF presented challenges during the study aimed at modifying its crystalline form. However, two new supramolecular forms, a co-crystal and an ionic co-crystal, were isolated, the latter phase having potential for further formulation owing to its significantly enhanced solubility. Full article

Background: Campylobacter causes gastroenteritis worldwide with increasing antimicrobial resistance. Furazolidone (FZD) shows potential in resource-poor areas but needs further study. We aimed to assess the in vitro susceptibility of Campylobacter spp. to FZD, ciprofloxacin (CIP), and erythromycin (ERY) in a high-risk pediatric cohort and to evaluate the clinical relevance of resistance patterns using inhibitory quotient (IQ) pharmacodynamics. Methods: A two-phase prospective study (2012–2013, 2014–2015) was conducted at a tertiary pediatric hospital in Lima, Peru. Stool samples from children ≤24 months were cultured on selective media, with Campylobacter isolates identified via conventional bacteriological methods. Antimicrobial susceptibility was determined using Kirby–Bauer disk diffusion and regression-derived minimum inhibitory concentrations (MICs). IQ analysis correlated inhibition zones with therapeutic outcomes. Results: Among 194 Campylobacter isolates (C. jejuni: 28%; C. coli: 72%), resistance to CIP declined from 97.7% (2012–2013) to 83% (2014–2015), while ERY resistance rose from 2.3% to 9.4% (p= 0.002). No FZD resistance was observed, with mean inhibition zones of 52 ± 8 mm (2012–2013) and 43 ± 10.5 mm (2014–2015). MICs for FZD were predominantly <0.125 μg/mL, and all susceptible isolates demonstrated favorable IQ outcomes. Multidrug resistance (≥2 drugs) increased to 6.2% (2014–2015), though all MDR strains retained FZD susceptibility. CLSI and EUCAST breakpoints showed concordance for ERY (p = 0.724) but discordance for CIP (p = 0.022 vs. 0.008). Conclusions: FZD exhibits sustained in vitro efficacy against Campylobacter spp., even among MDR strains, contrasting with escalating fluoroquinolone and macrolide resistance. Full article

The Seven Masters of the Quanzhen 全真七子 sect served as central figures during the founding phase of Quanzhen Daoism and played key roles in the sect’s early development. Originally positioned as the “Northern Seven Perfected Ones” (Bei Qi Zhen 北七真), they were instrumental in propelling the prosperity and expansion of Quanzhen Daoism. Over time, their images subsequently proliferated across various media—including portrayals in stone inscription, painting, biography, and novel, undergoing transformations through inscriptions, paintings, biographies, and novels—transforming transmission channels from Daoist temples to stage performances and from street corners to modern screens. In the Jin and Yuan 金元 periods, Daoist biographies and inscriptions portrayed the Seven Masters as exemplary figures of Daoist practice. In folk novels and precious scrolls (Baojuan 宝卷) in the Ming 明 and Qing 清 dynasties, they were presented as legendary, divine immortals and distant ancestors available for narrative appropriation. In modern times—particularly due to the popularity of Jin Yong 金庸’s martial art novels—they completed their universalization as Daoist cultural resources blending chivalric ethos and entertainment value. Examining the evolution of the Seven Masters’ imagery, two fundamental implications emerge: First, this transformation was jointly shaped by the power structures, functional needs, and media forms of each era. Second, beneath the fluid representations from sacred patriarchs of the Jin–Yuan period to modern entertainment symbols, there is an enduring thread of Daoist transcendental consciousness. Full article

The concomitant utilization of flavonoids and α-tocopherol has the potential to establish a comprehensive antioxidant system that operates in both hydrophilic and lipophilic environments. The objective of this study was to examine the antioxidant interactions between dihydroquercetin, a flavonoid that has shown promise in various studies, as well as structurally related flavonoids, and α-tocopherol in various ratios. The antioxidant capacity was assessed using two ABTS^•+ radical-cation inhibition assays: a decolorization assay and a lag-time assay. The results of this study indicated that formulations of dihydroquercetin, quercetin, rutin, or morin with α-tocopherol exhibited additive or mildly subadditive interactions, independent of their ratios. A two-phase pattern was exhibited by the lag-time data, which, in comparison with individual components, allowed us to suggest that α-tocopherol appeared to dominate the initial phase of radical scavenging, while flavonoids became active in the later phase. This finding indicates that α-tocopherol may play a role in protecting flavonoids from premature oxidation in alcoholic media. The findings could prove valuable for the rational design of antioxidant formulations in the nutraceutical, cosmeceutical, and pharmaceutical industries. Additionally, the two-stage antioxidant behavior offers prospects for the formulation of straightforward, cost-effective analytical approaches to measure components in binary antioxidant formulations. Full article

A pivotal role of metabolic reprogramming in urothelial carcinoma is hallmarked by the dependence of two-fold faster proliferation of urothelial carcinoma cell line T24 than benign cell line TRT-HU1 on five-fold higher glucose (basal) 16 mM vs. 3 mM in McCoy’s 5A media and Keratinocyte Serum Free media, respectively. Here, we report that an additional 10% increase to 17.6 mM and 3.3 mM glucose significantly shortens the doubling time by 3 h and 1 h for T24 and TRT-HUI, respectively. T24 grown at 17.6 mM glucose lowers the confocal localization of the fatty acid mimetic, Betulinic Acid (BA) conjugated to FITC (BA-FITC) with Mito Tracker Red (mitochondrial marker), which doubles the IC50 of BA and BA-FITC by lowering cell cycle arrest in the G0/G1 phase from 54.2% to 43.8% and caspase-3/7 mediated apoptosis and by reversing caspase-3, p53, PTEN, GAPDH, and XIAP gene expression induced by BA in T24 grown at basal glucose (16 mM). Besides slowing the glycogen and pH decline of T24 at basal glucose, BA exhibited an eight-fold higher IC50 than Mitomycin C (MC) on TRT-HU1 by not mimicking the glucose-insensitive cycle arrest and apoptosis of MC. Overall, the glucose sensitivity of the lower IC50 of BA-FITC and BA on T24 vs. TRT-HU1 supports the safety of BA conjugates for theragnostic purposes. Full article

The present study explores the affordances of virtual reality (VR) technologies to enhance digital and media literacy skills within an interdisciplinary and inclusive K-12 English as a Foreign Language (EFL) learning context. Addressing gaps in research on the design and impact of VR experiences in secondary education, the study investigates VR affordances not only as a learning tool, but also as a medium for knowledge co-creation through learning by doing, with students acting as the agents within digital social contexts. The study was conducted for two years, with 59 participants aged 13–14 years old, following a structured five-phase intervention model with the intent to comply with DigComp 2.2 guidelines for digital citizenship and the Universal Design for Learning (UDL) for inclusive educational practices. The phases involved (a) training on the technological level to leverage digital tools; (b) media and information literacy (MIL) instruction in VR; (c) collaborative VR artifact creation; (d) peer evaluation; and (e) dissemination with peers from other sociocultural contexts for an iterative process of continuous content improvement and social discourse. Mixed methods data collection included pre/post-course surveys, pre/post-tests, observation journals, and student-generated VR artifact evaluations. The findings indicate consistent learning gains across both years, with an average pre–post gain of 18 points (Cohen’s d = −2.25; t = −17.3, p < 0.001). The VR-supported intervention fostered complex skillset building within a VR-supported dynamic learning environment that caters to diverse needs. Students’ reflections informed a framework for designing inclusive media literacy in VR, structured around three main pillars: Narrative Structure, Strategic Design, and Representation Awareness. These themes encapsulate the practical, cognitive, and ethical dimensions of VR design. Sub-themes with examples contribute to understanding the key design elements of VR in promoting participatory engagement, digital and media literacy, critical discourse, and inclusive education. The sub-themes per pillar are signaling and multisensory cues, storyline, and artful thinking; schema formation, multimedia encoding, and optimal cognitive load; and bias-free, respect for emotional impact, and language and symbols. Complementary quantitative findings confirmed the themes of the proposed framework, revealing a positive correlation between the perceived ease of use (PEoU) with digital skills development and a negative correlation between perceived usefulness (PU) and cognitive load. The study concludes with recommendations for pedagogy, curriculum design, and future research to empower learners in shaping sustainable digital futures. Full article

Vibrational double diffusion has gained increasing attention in recent studies due to its role in enhancing mixing, disrupting thermal boundary layers, and stabilizing convection structures, especially in nanofluids and porous media. This study focuses on the case of two-phase nanofluid flow in the presence of vibrational effects. The flow domain is a fined chamber that is filled with a non-Darcy porous medium. Two concentration formulations are proposed for the species concentration and nanoparticle concentration. The thermal radiation is in both the x- and y-directions, while the flow domain is considered to be inclined. The solution technique depends on an effective finite volume method. The periodic behaviors of the stream function, Nusselt numbers, and Sherwood numbers against the progressing time are presented and interpreted. From the major results, a significant reduction in harmonic behaviors of the stream function is obtained as the lengths of the fins are raised while the gradients of the temperature and concentration are improved. Also, a higher rate of heat and mass transfer is obtained when the vibration frequency is raised. Furthermore, for fixed values of the Rayleigh number and vibration frequency (Ra = 10⁴, σ = 500), the heat transfer coefficient improves by 27.2% as the fin length increases from 0.1 to 0.25. Full article