Search Results (92,625)

The study examines in detail the possibility of using well casing as a means for power transmission downhole to high-power equipment, such as pumps. The ultimate goal is to transmit single-phase AC to the well bottom and then convert it into three-phase power to operate the downhole equipment, which is a major challenge for such applications. The focus is set on the particular problem of the contact between the packer slips and the casing, and the study aims to examine it in detail. An analysis of high-voltage effects (arcing, etching, contact welding, and heating) and possible mechanical and chemical failures (fatigue, corrosion, surface treatment, contact pressure, and stresses) is performed. These effects are evaluated using common physics laws, and the mechanical structural behavior of the contact is analyzed through Finite Element Method simulation. The performed calculations and analyses show that this is a viable and innovative solution that eliminates the use of cables (umbilicals), especially for long distances and in deep wells. The main contribution is the validated conceptual design, with physical prototyping and tests planned for the next stage of this research. Full article

Chromizing layers are widely employed in industrial applications due to their superior wear resistance and corrosion resistance. In this study, GCr15 bearing steel was chromized by a solid powder pack chromizing method, and the influence of chromizing time on the microstructure and mechanical properties of the chromized layers was systematically investigated. The results reveal the presence of fine pores dispersed both on the surface and at the chromized layers/substrate interface. The concentration of the Cr and Fe elements displays a gradient distribution throughout the layers. The chromized layers are primarily composed of (Cr,Fe)₂₃C₆ and (Cr,Fe)₇C₃ phases. With an increase in the chromizing time, the thickness and hardness of the chromized layers are gradually increased. A large number of radial and circumferential cracks are observed both within and around the indentation regions, accompanied by spalling at the edge. The brittleness of the chromized layer is increased, and the spalling phenomenon becomes more pronounced with prolonged chromizing time. The chromizing treatment significantly improves the tribological performance of GCr15 steel, reducing its wear rate to approximately one fifth of that of the untreated substrate. Full article

Cell motility is a process central to life and is undoubtedly influenced by mechanical and chemical signals. Even so, other stimuli are also involved in controlling cell migration in vivo and in vitro. Among these, electric fields have been shown to provide a powerful and programmable cue to manipulate cell migration. There is now a clear consensus that the electromigration of membrane components represents the first response to an external electric field, which subsequently activates downstream signals responsible for controlling cell migration. Here, we focus on a specific mode of electrotaxis: frictionless, amoeboid-like migration. We used the Finite Element Method to solve an active gel model coupled with a mathematical model of the electromigration of aquaporins and investigate the effect of electric fields on ameboid migration. We demonstrate that an electric field can polarize aquaporins in a cell and, consequently, that the electromigration of aquaporins can be exploited to regulate water flux across the cell membrane. Our findings indicate that controlling these fluxes allows modulation of cell migration velocity, thereby reducing the cell’s migratory capacity. Our work provides a mechanistic framework to further study the impact of electrotaxis and to add new insights into specific modes by which electric fields modify cell motility. Full article

While most efforts are aimed at preventing the surface roughening and colour change of wood due to weathering, some customers, mainly for decorative reasons, want wooden objects and elements to give the impression that they have been weathered for a long time. In this study, the simulated weathering of numerous softwoods as well as ring-porous and diffuse-porous woods by sandblasting and greying with iron sulphate was investigated. Calculations of the correlations between wood density, orientation, mass loss and thickness reduction by sandblasting were performed, and the difference between the hardness of late and early wood and the surface profile parameter P_t showed that the surface profiles correlate strongly with mass loss, especially in the tangential orientation. Softwoods appeared to be the most promising for simulated profiling, especially spruce and larch with tangential surfaces. Among the ring-porous woods, oak and sweet chestnut also delivered good results. Full article

Applying therapeutic elements to prevent injury from potential infections is a promising avenue in the development of novel bone substitutes; however, achieving controllable delivery of therapeutic ions is crucial to realizing their expected functions. In this study, a Ag nanoparticle core wrapped in an MSN shell was successfully synthesized using a one-pot sol–gel process. Subsequently, the produced Ag@MSN was functionalized with amino and carboxylic groups. The experimental results indicated that these core–shell-structured Ag@MSN spheres had a uniform size of ~60 nm and a specific area of 904.6 m²/g. Their release profiles, influenced by different surface charges, were investigated, with the aim of achieving sustainable release of Ag ions. The concentration-dependent biological effects of Ag@MSNs, including their anti-infection properties and biocompatibility, were comprehensively characterized in vitro, considering their potential for use as bioactive bone substitutes. Functionalized mesoporous silica nanoparticles significantly enhanced the sustained release profile of silver ions, achieving a cumulative release efficiency greater than 50% within 24 h. These nanoparticles also demonstrated exceptional antibacterial efficacy, with an inhibition rate surpassing 98% at a concentration of 30 μg/mL, while concurrently maintaining cell viability above 88%, indicating high biocompatibility. We achieved our goal of effectively decreasing the burst release of Ag to satisfy the intrinsic need for long-term resistance to bacteria in bone substitutes and stimulate osteoblast proliferation. Full article

This paper presents a fully passive and wireless glucose concentration sensor that integrates a capacitively coupled complementary split-ring resonator (CSRR) with an H-slot UHF RFID antenna. The CSRR serves as the primary sensing element, where changes in glucose concentration alter the effective permittivity of the surrounding solution, thereby modifying the resonator capacitance and shifting its resonance behavior. Through near-field capacitive coupling, these dielectric variations affect the antenna input impedance and backscatter response, enabling wireless sensing by modulating the maximum read range. The proposed sensor operates within the 902–928 MHz UHF RFID band and is interrogated using commercial RFID readers, eliminating the need for specialized laboratory equipment such as vector network analyzers. Full-wave electromagnetic simulations and experimental measurements validate the sensor performance, demonstrating a variation in the read range from 6.23 m to 4.67 m as glucose concentration increases from 50 to 200 mg/dL. Moreover, the sensor exhibits excellent linearity, with a high coefficient of determination ($R^2=0.986$) based on the curve-fitted data. These results underscore the feasibility of the proposed sensor as a low-cost and fully portable platform for concentration monitoring, with potential applications in liquid characterization and chemical sensing. Full article

In order to solve the problems of wrinkling, cracking, and springback that occur during the single deep drawing forming process of household stainless steel sinks without annealing, the deep drawing process of thin SUS304 stainless steel was studied using a DYNAFORM numerical simulation and experimental analysis. The uniaxial tensile test results indicate that 304 stainless steel exhibits different levels of plasticity in different directions. The TD direction, which is perpendicular to the rolling direction, has the lowest elongation, which is 11.8% lower than that in the rolling direction. The maximum bulging depth of the thin specimens in the finite element simulation reached 17.142 mm, and the maximum bulging depth of the specimens with cracks in the experiment was 16.572 mm, indicating that the results of the finite element simulation were in good agreement with those of the experiment. Finally, through simulation and experimentation, the optimal process for forming stainless thin steel sinks was obtained when the fillet radius R was 5 mm, the stamping speed was 20 mm/s, the blank holder force was 3 MPa, and the friction coefficient was 0.120. Full article

The Mediterranean soft-shell turtle (Trionyx triunguis) is classified as critically endangered by the IUCN. Effective conservation requires a clear understanding of its reproductive strategies and population structure. By combining mitochondrial DNA tandem repeat-region profiling with genome-wide SNP data obtained through 3RADseq, we gained high-resolution insights into the genetic composition and breeding behavior of Mediterranean populations. Our results revealed complex reproductive dynamics, including multiple paternity, sperm storage, and repeated nesting within a single season—strategies that enhance genetic diversity in small, fragmented populations. Using SNP-based kinship inference, we estimated the number of breeding females and identified full and half-sibling groups, offering a robust genomic framework for assessing population size and structure. Genetic similarity patterns highlighted moderate differentiation among Israeli river populations, suggesting some connectivity, while samples from Türkiye were clearly distinct, reflecting long-term geographic and genetic separation. This integrative approach provides a scalable, repeatable tool for long-term monitoring. The combined use of maternal and biparental markers enables detailed tracking of genetic diversity, breeding contributions, and demographic trends—key elements for designing informed, adaptive conservation strategies. Full article

This study systematically investigates the color origin and coloration mechanisms of yellow-green nephrite from Ruoqiang, Xinjiang, using multiple analytical techniques including hyperspectral colorimetry, X-ray fluorescence (XRF) spectroscopy, titrimetry, laser ablation inductively coupled plasma–mass spectrometry (LA-ICP-MS), Raman spectroscopy and ultraviolet–visible (UV-Vis) spectroscopy. A pioneering quantitative model (R² = 0.942) was established between hue (H) and the Fe₂O₃ ratio (Fe₂O₃/TFe), revealing that the coloration mechanism is jointly governed by Fe³⁺ charge transfer (300–400 nm absorption band) and Fe²⁺→Fe³⁺ transitions (600–630 nm absorption band). Furthermore, the intensity variation in the 3651 cm⁻¹ Raman peak serves to further confirm the critical role of Fe³⁺ occupancy in the tremolite lattice for color modulation. In combination with the partition patterns of Rare Earth elements (REEs) (right-leaning LREE distribution with negative Eu anomaly) and trace element characteristics, this study supports the classification of Ruoqiang yellow-green nephrite as a high oxygen fugacity magnesian marble-type deposit. In this type of deposit, the ore-forming environment facilitates Fe³⁺ enrichment and yellow-green hue formation. The findings provide new theoretical insights into the chromatic genesis of yellow-green nephrite and hold significant implications for its identification, quality grading, and research on metallogenic mechanisms. Full article

Many existing reinforced concrete (RC) frames with brick infill walls are vulnerable to earthquake damage, particularly when the walls contain window openings that reduce the lateral resistance. This study aims to examine the seismic performance of RC frames strengthened with U-shaped precast concrete (PC) wall panels. In the proposed method, the window-containing brick infill walls within the RC frames are replaced with factory-fabricated U-shaped PC wall panels, thereby converting the infill into a strong and rigid structural element while preserving the openings. The panels are anchored to the RC frame using post-installed anchors inserted through predrilled holes, allowing for rapid and secure installation with minimal on-site work. To validate the method, five full-scale, one-bay, one-story RC frames were constructed and tested under reversed cyclic lateral loading. Three frames were strengthened with U-shaped PC wall panels of varying thicknesses and large openings. Displacement-controlled cycles following ACI 374.1-05 (R7.0) were applied, with three cycles at each drift ratio stage, and no axial load was applied to the columns. Compared with the reference specimen with a U-shaped brick wall, the strengthened frames exhibited up to 3.29 times higher lateral strength, 4.39 times higher initial stiffness, and 4.33 times greater energy dissipation capacity. These findings demonstrate that the proposed strengthening technique significantly enhances seismic resistance while maintaining the architectural openings, offering a practical and efficient solution for upgrading low-rise RC buildings. Full article

High levels of phosphorus cause eutrophication, leading to water blooms and making the water undesirable in aquatic environments. Surface water pollution by phosphorus (P) is caused by both point and diffuse sources. Despite the recent technological advancements in wastewater phosphorus removal, this element persists in aquatic ecosystems, particularly in sediments, often in non-bioavailable forms (in the case of precipitation by aluminum salts) or within biomass associated with high concentrations of heavy metals, rendering it unsuitable for reuse. In this paper, we review the measures and methods commonly used for reducing or removing bioavailable phosphorus, with a focus on the strategies and methods for direct in situ phosphorus removal or reuse, including the use of microbial biofilms and aquatic macrophytes, natural and constructed wetlands, and biotised (biologically enhanced) solid-phase sorbents or woodchip bioreactors. This paper also highlights the significance of bioavailable phosphorus from both the hydrochemical perspectives, examining phosphorus speciation, solubility, and the geochemical interactions influencing mobility in water and sediments, and the biological perspectives, which consider phosphorus uptake, bioaccumulation in aquatic organisms, and the role of microbial and plant communities in modulating phosphorus cycling. This overview presents sustainable phosphorus management approaches that are key to reducing eutrophication and supporting ecosystem health. Full article

Fundamental research, exploration, extraction, and metallurgical studies of rare earth elements (REEs) require the use of analytical techniques. Recently, emerging developments of analytical instrumentation for REEs have taken place, with some of them having shrunk in size, becoming handheld devices. The Flame and Graphite Furnace AAS, ICP-OES, and MP-AES are standard laboratory techniques used for the analysis of REEs. ICP-MS, ICP-MS/MS, ICP-TOF-MS, HR-ICP-MS, MH-ICP-MS, and MC-ICP-MS are popular techniques for REE analysis thanks to their ultrahigh sensitivity, minimal interference effects, and broad applicability. The INAA, XRF, LIBS, and LA-based ICP-MS techniques are widely employed for the direct analysis of solid samples. The TIMS, SIMS, and SHRIMP are common techniques used for dating isotopic REE deposits. The portable XRF, LIBS, and Raman spectrometer devices can perform on-the-spot in situ analysis, which may help make speedy decisions in the exploration study of REEs. Currently, hyperspectral remote sensing platforms, such as handheld, drone, and satellite-based devices, are preferred for the exploration of REEs due to their cost-effectiveness, which enables the coverage of large areas in a limited amount of time. The use of microanalytical sensors installed on remotely operated vehicles has been successfully applied in analyzing rich REE-bearing deposits in the deep sea. In general, this review provides in-depth information on all essential aspects, from analytical instruments to cutting-edge developments in the analysis of REE-bearing resources. Full article

Extensive research is underway on a variety of functional foods that support consumer health. A promising combination is milk (a drink with high nutritional value), fortified with spices (naturally rich in antioxidant compounds) and supplemented with low-calorie, health-promoting sweeteners. The aim was to analyze the antioxidant activity (AA), total polyphenol content (TPC), and mineral composition of milk beverages fortified with a mixture of spices and sweeteners and to verify the interactions between these ingredients. Twenty-four variants of milk drinks were prepared with the addition of three types of spice mixtures (1:1) of clove (Cl), cinnamon (Ci), and turmeric (Tu) with the shares of 2.5%, 5%, 7.5%, and 10%, and two types of sweeteners—erythritol (E) and stevia (S)—as well as six control samples, including three 10% aqueous solutions of spice mixtures. AA was measured using the ABTS, FRAP, and DPPH methods. TPC was determined using the Folin–Ciocalteu method. Mineral content (Ca, Mg, Fe, Cu, and Zn) was assessed using the FAAS/FAES method. The highest AA was demonstrated for beverages with Cl-Ci and Cl-Tu, whereas the highest TPC was found in those with Cl-Tu. AA and TPC values increased with the increase in the share of spices in the beverages, and both measurements were significantly higher in beverages with erythritol compared to those with stevia. Despite the 4–5 times lower TPC, 3–8 times higher AA was demonstrated in beverages with the addition of 10% spice mixtures than their corresponding control samples (aqueous solutions with the addition of 10% spice mixtures), which suggests the great role of interactions between nutrients in food. For beverages with 10% Cl-Ci/Cl-Tu mixtures, significantly higher ABTS, FRAP, and DPPH were observed than would result from the simple sum of AA of the components (synergistic effect). The opposite (antagonistic) effect was observed for beverages with Ci-Tu. AA was positively correlated with the content of Fe, Mg, and Cu; negatively with Ca; and not correlated with Zn. The results suggest that the most health-promoting properties are exhibited by the milk drink with the addition of 10% Cl-Tu and erythritol, demonstrating the highest AA and TPC, the strongest synergistic effect of the components, and the highest content of Mg and Zn. This study highlights the importance of carefully selecting and combining ingredients to maximize the antioxidant properties of functional beverages. However, further research is needed to expand knowledge on this issue. Full article

The use of pultruded-fibre-reinforced polymer (PFRP) composite profiles in structural applications is rapidly increasing, due to their high strength-to-weight ratio, corrosion resistance, and durability. Bolted joints between PFRP play a critical role, as localized high stresses in a material that typically exhibits brittle behaviour—especially in tension and shear—can lead to sudden failure. This study aims to investigate the mechanical performance of such bolted connections (in terms of stiffness, strength, displacement capacities and failure modes), contributing to the development of reliable yet optimized design criteria for structural applications. In particular, numerical analyses of single-bolted connections in PFRP profiles are presented in the paper. To emphasize the general validity of the model and demonstrate its applicability across different configurations, the simulations were validated against experimental results from three separate test campaigns, which varied in both material (three different PFRP composites) and geometry (profile thickness, bolt diameter, and hole–end distance). Finite element models using continuum shell elements in ABAQUS, based on the Hashin failure criteria, successfully captured typical failure modes, including shear-out and pin-bearing. Two analysis approaches—implicit and explicit solvers—were also compared and discussed. Sensitivity analyses were carried out to enhance the model’s accuracy and its computational efficiency. The validated model was then extended to simulate different configurations, investigating the role of the main parameters influencing the connections. Full article

Research has long supported the use of and engagement with music as a catalyst for health and wellbeing. However, there is a lack of research exploring how the structures, rituals and ‘minor gestures’ that go alongside music-making, making-with the materiality of music and engagement, can positively impact health. Using assemblages of interconnected community music projects in North Lanarkshire, Scotland, as collective ethnographic entry points, we examine how collective routines and communal activities—through the interplay of material-discursive practices that play out in structural elements, memories, and shared experiences—contribute to the creation of meaningful social exchanges, stability, sense of belonging and becoming. We argue that the benefits of music ‘interventions’ are not solely outcomes from isolated activities, but from the accumulative habits and rituals they affect, offering a new perspective on health as a dynamic process. This reframing invites a transcending of measurement in relation to the impact of music on individual and social wellbeing. Through this, we challenge traditional, conventional wellbeing scales and measures and call for a broader understanding of music’s potential in addressing health inequalities, concluding with implications for scalable community music models that contribute to expanding possibilities for research–practice–policy partnerships in health and social care systems. Full article