Search Results (2,300)

Nanoaperture optical tweezers (NOTs) were used to analyze conalbumin in various forms. By analyzing the power spectrum of the NOT-transmitted laser signal, differences between iron and iron-free conalbumin were observed; the corner frequency extrapolated to zero-laser power was significantly larger in magnitude for conalbumin with iron, which was interpreted as coming from the enhanced electrostatic interactions close to the surface of the nanoaperture. Conalbumin in a diluted, but otherwise unprocessed, egg white sample showed the same behavior as purified iron-free conalbumin. Dynamic two-state transitions in the NOT signal were observed for iron-free conalbumin and conalbumin in egg white samples. We used this to determine the dominant state as a function of temperature, with one state showing a maximum occupancy around 30.4 ${}^{\circ }\mathrm{C}$. Deconvolution of the probability distribution function was used to find the energy landscape associated with this two-state transition. This work shows the potential of NOTs to see variations with metal ion binding, including conformational dynamics related to the binding at timescales not accessible to other methods. Full article

Tissue engineering is a multidisciplinary field that aims to address tissue and organ failure by integrating scientific, engineering, and medial expertise. Gelatin is valued in this field for its biocompatibility; however, it faces thermal and mechanical weaknesses that limit its biomedical utility. This work proposes a strategy for improving gelatin properties by fabricating semi-interpenetrating polymer networks via in situ Diels–Alder crosslinking within gelatin colloidal solutions. Ten systems with variable polymer concentrations (2–4%) and crosslinking degrees (2–5%) were prepared and characterized. Rheological analysis revealed that elastic modulus, zero-shear viscosity, and complex viscosity were substantially enhanced, being especially dependent on the crosslinking degree, while critical strain values mostly depended on gelatin concentration. The incorporation of a synthetic Diels–Alder-crosslinked network also improved the thermal stability of gelatin hydrogels, particularly at physiological temperatures. Additionally, these systems exhibit favorable buoyancy, swelling and biodegradation profiles. Collectively, the resultant hydrogels are cytocompatible, solid-like, and mechanically robust, allowing for further tunability of their properties for specific biomedical uses, such as injectable matrices, load-bearing scaffolds for tissue repair, and 3D bioinks. Full article

The traction behavior of lubricant films forms the foundation of dynamic modeling for aeroengine mainshaft ball bearings. Its accuracy directly determines the reliability of predicted dynamic responses and the available design safety margins. Existing traction models produce artificial friction in the zero slip region and exhibit strong sensitivity to ball size effects, which leads to significant deviations from experimental observations. These limitations make them unsuitable for high-fidelity analyses of aeroengine mainshaft bearings. In this study, a self-developed high-speed traction test rig was used to systematically measure the traction–slip responses of three aviation lubricants, including the newly developed 4102 (7 cSt) and the inservice 4050 (5 cSt) and 4010 (3 cSt). The tests covered a wide range of operating conditions, including maximum Hertzian pressures of 1.0 to 1.5 GPa, oil supply temperatures of 25 to 120 °C, entrainment speeds of 25 to 40 m/s, and slide–roll ratios (SRR) of 0 to 0.3. The evolution of lubricant traction characteristics was examined in detail. Based on the experimental data, a four-parameter and three-coefficient traction model was proposed. This model eliminates the non-physical traction outputs at zero slip observed in previous formulations. When embedded into the bearing dynamic simulations, the maximum deviation between the predicted friction torque and the measured values is only 3.79%. On the basis of typical operating conditions of aeroengine bearings, lubricant selection guidelines were established. Under combined high-speed, light-load, and high-temperature conditions, the high-viscosity lubricant 4102 is preferred because it suppresses cage sliding and enhances film stiffness. When the cage slip ratio is below 15% and lubrication is sufficient, the low-viscosity lubricant 4010 is recommended, followed by 4050, in order to reduce frictional heating. This study provides a theoretical basis for high-accuracy dynamic design and lubricant selection for aeroengine ball bearings. Full article

The specific heat capacity of skinned muscle in an adhering rigor solution was studied with differential scanning calorimetry (DSC) heating runs to search for a heat sink in the sarcomere of the muscle. To elucidate the contribution of major myoproteins to heat capacity, myosin and actin were partially removed by high-KCl and gelsolin treatments, respectively. Differential heat denaturation of myosin (together with α-actinin) and actin was induced to confirm their contributions. On the DSC curve, aside from the endothermic peaks representing ice melting and protein denaturation, the steady baseline level showed a significant increase in basal heat capacity in the presence of skinned muscle compared to the rigor solution alone. In the physiological temperature range from 10 to 25 °C, untreated skinned muscle in the native state (non-denatured) introduced an extra basal heat capacity of 0.4 J K⁻¹ (g evaporable weight)⁻¹, which was diminished by both removing and denaturing actin and was additionally increased by removing myosin; myosin denaturation had little effect on the basal heat capacity. Based on these results, we considered actin to be the fundamental source of extra basal heat capacity, which was partly suppressed by the thermally stable region of myosin under rigor conditions. This extra basal heat capacity was roughly preserved at sub-zero temperatures, suggesting the involvement of non-freezing water molecules. The extra basal heat capacity may have contributed to thermal buffering during muscle function via actin-associated hydration. As a supplemental result, we found a small reversible endothermic peak around −21 °C, which was suppressed in the presence of skinned muscle. Heating beyond the denaturing temperatures reduced this suppression effect. Full article

Conjugate heat transfer in non-Newtonian fluids is a fundamental phenomenon in thermal management systems. This study investigates the combined effects of magnetic field topology, heat absorption/generation, the thermal conductivity ratio, enclosure inclination, and power-law rheology using the lattice Boltzmann method. The parametric analysis shows that increasing the heat generation coefficient from −5 to +5 reduces the average Nusselt number by up to 97% for the pseudo-plastic fluids and up to 29% for the Newtonian fluids, while entropy generation increases by 44–86% depending on the thermal conductivity ratio. Increasing the inclination angle from 0° to 90° weakens convection and reduces heat transfer by nearly 77%. Magnetic field strengthening (Ha = 0–45) decreases the Nusselt number by 20–55% depending on the barrier temperature. Among all tested conditions, the highest thermal performance (maximum heat transfer and minimum entropy generation) occurs when using a pseudo-plastic fluid (n = 0.75), exhibiting high wall conductivity (TCR = 50) and heat absorption (HAPC = −5), a cold obstacle (θ_b = 0), and zero inclination (λ = 0°), as well as in the absence of the magnetic field effects. These quantitative insights highlight the controllability of the conjugate heat transfer and irreversibility in the power-law fluids under coupled magnetothermal conditions. Full article

A rise in seawater salinity results in an increase in its viscosity, which presents a coupled influence on the distribution of fluid pressure, temperature and deformation at the sealing face, leading to fluctuations in sealing performance and forming the salinity effect in seawater thermoelastohydrodynamic lubrication (TEHL). Here, for a double spiral groove face seal, a TEHL model is established and numerical analysis is carried out, taking account of the salinity effect and cavitation effect, with the aim to ensure that the seal maintains stable performance under varying conditions of sea depth and speed. It is found that the effect of salinity on the opening force and leakage rate exhibits obvious nonlinear variations. As salinity rises from 0 to the standard 35 g/kg, the opening force changes by about 5%, and there is a transition between forward and reverse leakage, with variations of approximately ±100%. More importantly, the double spiral grooves offer the potential for a zero-leakage design in seawater face seals, even under pressures exceeding 4 MPa, through precise design. Additionally, the double spiral groove face seal shows excellent adaptability under multipoint conditions and can facilitate a zero-leakage design in varying pressure, speed and temperature conditions. This provides theoretical support for deep-sea equipment and applications in other extreme environments. Full article

The final stage of the drinking water treatment process yields two distinct outputs: treated water and the resulting sludge. This sludge is composed of raw water impurities, coagulation and flocculation agents, and various other additives. In any volume of processed drinking water, the continuous production of sludge is not negligible, leading to a significant environmental impact. This is particularly concerning when aluminium-based agents are used, as these compounds are strongly implicated in potential detrimental health risks. This situation is significantly worsened when raw water temperature approaches zero, as the treatment process efficiency is greatly diminished. Drinking water treatment at low temperatures faces a culmination of adverse effects, including a lower rate of hydrolysis and a reduced floc size, both of which negatively impact sedimentation. An effective strategy for suppressing the high dosing of chemicals is the suitable choice of ratio between acidity and the basicity of the treated water. Simply maintaining the pH value that was optimised for higher temperatures is detrimental, leading to, among other issues, increased sludge accumulation. Therefore, attention should instead be concentrated on the pOH value. A simple algebraic relation is proposed for converting the optimised pH value for higher temperatures to an optimum value for more moderate or low-temperature conditions. The application of this method results in a reduction in the amount of chemical agents required and consequently a reduction in the volume of sludge produced. Full article

Phenolic compounds are widespread environmental contaminants whose removal from water and wastewater is essential for ecosystem protection. Among the several purification technologies, the use of zero-valent metals has gained increasing interest in recent years. The identification of effective and environmentally friendly materials is a key issue for the development of this technology. In this study, zero-valent magnesium (ZVMg), a highly reactive non-toxic material, was used for the first time for the degradation of gallic acid (GA), chosen as a model phenolic compound, in an aqueous system. Several tests were conducted in order to identify the effect of pH, ZVMg amount, and temperature on the process performance. Moreover, the reusability of the reactive material in subsequent treatment cycles was assessed. Optimal operational conditions were achieved with a ZVMg amount of 0.3 g, corresponding to a ratio of 0.33 g_GA/g_Mg, reaching a removal efficiency of almost 90% in about 180 min. The performance was clearly favored by an alkaline environment, and yields close to the maximum values were reached under uncontrolled pH conditions. The increase in temperature significantly accelerated the reaction rate, which followed pseudo-first-order kinetic law, achieving high abatement percentages with a reduced quantity of ZVMg. Finally, Mg⁰ demonstrated good reusability, maintaining high efficiency, close to 78%, for up to four cycles, with the possibility of restoring the material’s activity through acid washing. The detected results confirm that ZVMg is a promising and sustainable reactive material for environmental remediation processes, offering an effective alternative for the treatment of water contaminated by phenolic compounds. Full article

Cherry tomatoes are highly appreciated for their nutritional value but remain highly perishable due to rapid respiration and senescence. This study evaluated a multi-hurdle strategy combining plasma-activated water (PAW), sodium caseinate-based edible coating, and antioxidant active packaging to preserve minimally processed (MP) cherry tomatoes stored at 1 °C, 4 °C, and 8 °C for 15 days. Quality evolution was monitored through physical, chemical, nutritional, and microbiological parameters and described using pseudo-zero- and first-order kinetic models, with temperature dependence expressed by the Arrhenius equation. The combined treatment (prototype) slowed the degradation rates of pH, titratable acidity, total polyphenols, and antioxidant capacity, as reflected by consistently lower kinetic rate constants across all temperatures. Prototype samples showed better retention of polyphenols and antioxidant capacity, particularly at 1 °C and 4 °C, without detrimental effects on visual appearance. Metagenomic analysis revealed that the multi-hurdle treatment reshaped the microbial community, reducing the relative abundance of potentially problematic taxa such as Acinetobacter johnsonii and limiting the occurrence of antimicrobial resistance (AMR) genes at the end of storage. This study provides the first integrated assessment of PAW, edible coating, and antioxidant active packaging as a synergistic multi-hurdle strategy, demonstrating their combined ability to extend shelf life while modulating the microbiome and resistome of minimally processed cherry tomatoes. Full article

An attractive cryogenic near-zero thermal expansion (ZTE) behavior was achieved in the Mn₃Cu_0.5Ge_0.5N_0.78C_0.22 compound, spanning a broad temperature window of 120 K (5 K to 125 K) with an average coefficient of thermal expansion (CTE) of α = 0.68 × 10⁻⁶ K⁻¹. Furthermore, the effect of sintering temperature and holding time on thermal expansion and magnetic properties were investigated. Two distinct magnetic phase transitions are evident in the magnetization–temperature (M-T) curve of Mn₃Cu_0.5Ge_0.5N_0.78C_0.22, which precede the near-ZTE behavior. These two antiferromagnetic (AFM)-like ordering transitions are hypothesized to play a pivotal role in governing the ZTE behavior, as they induce two episodes of negative thermal expansion (NTE). The realization of ZTE behavior is thus attributed to the counterbalance of these two NTE contributions, which can be effectively tuned by varying the carbon content or optimizing the sintering process parameters. Collectively, these results demonstrate significant potential for the design of diverse cryogenic functional materials. Full article

We investigate momentum transport in ferromagnetic–plasmon heterostructures using Keldysh field theory and energy–momentum tensor formalism. A three-layer model reveals that plasmon frequency shifts generate a non-zero expectation value for the $xz$-component of the energy–momentum tensor $⟨T_{xz}⟩$ through magnon–plasmon coupling. The momentum transport exhibits linear velocity dependence, with temperature behavior transitioning from exponential suppression at low temperatures to linear growth at high temperatures, governed by the magnon energy gap. Spatial oscillations follow $sin(2n\pi z/h)$ patterns within the ferromagnetic layer. This framework provides fundamental insights into quantum momentum transport mechanisms in magnetic systems. Full article

Effective fishery management in coastal waters requires accurate assessments of species–environment relationships, particularly in data-rich but zero-inflated contexts (i.e., datasets with an excess of zero catches). Here, we used fishery-independent trawl survey data collected from 2018 to 2019 in the offshore waters of southern Zhejiang Province of China to investigate the spatio-temporal distribution of Setipinna taty (scaly hairfin anchovy) and its environmental determinants. Given the high frequency of zero catches, we fitted both zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models and selected the best-performing approach using the Akaike information criterion (AIC). Cross-validation indicated that the ZINB model (RMSE: 199.1, R²; 0.25) outperformed ZIP model (RMSE: 239.4, R²; 0.23). Temperature, depth, and salinity were key predictors of S. taty abundance, which generally occurred at depths of 20–40 m and salinities of 26–34 psu. We then applied the optimal ZINB model to predict S. taty distributions in spring, summer, and autumn of 2020. The predictions indicated a summer peak in abundance and a nearshore-to-offshore decreasing gradient, and were broadly consistent with the spatial distribution trends observed in the 2020 survey data. The highest predicted densities were located in nearshore areas off Wenzhou and Taizhou, west of 122° E. By clarifying the key environmental factors shaping S. taty distribution and applying zero-inflated count models to account for an excess of zero catches, which occur more frequently than expected under standard negative binomial models, this study provides an improved basis for effective conservation and sustainable utilization of S. taty resources in the southern offshore waters of Zhejiang; nevertheless, predictive performance could be further improved by incorporating additional environmental and biotic covariates together with extended spatio-temporal data. Full article

African catfish (Clarias gariepinus, AC) is one of the most widely farmed freshwater fish species in Central Europe. Processing operations generate up to 55% by-products (BPs), predominantly carcasses rich in proteins, lipids, and minerals. This study develops a comprehensive valorization process for ACBPs to recover gelatin, protein hydrolysate, fish oil, and pigments. The processing protocol consisted of sequential washing, oil extraction, demineralization, and biotechnological treatment to disrupt the collagen quaternary structure. A two-factor experimental design was employed to optimize the processing conditions. The factors included the extraction temperatures of the first (35–45 °C) and second fraction (50–60 °C). We hypothesized that enzymatic conditioning, combined with sequential hot-water extraction, would yield gelatin with properties comparable to those of mammalian- and fish-derived gelatins, while enabling a near-zero-waste process. The integrated process yielded 18.2 ± 1.2% fish oil, 9.8 ± 2.1% protein hydrolysate, 1.7 ± 0.7% pigment extract, and 25.3–37.8% gelatin. Optimal conditions (35 °C/60 °C) produced gelatin with gel strength of 168.8 ± 3.6 Bloom, dynamic viscosity of 2.48 ± 0.02 mPa·s, and yield of 34.76 ± 1.95%. Life cycle assessment (LCA) identified two primary environmental hotspots: water consumption and energy demand. This near-zero-waste biorefinery demonstrates the potential for comprehensive valorization of aquaculture BPs into multiple value-added bioproducts. Full article

We have developed a magnetic holographic memory using transparent bismuth-substituted rare-earth iron garnet as a next-generation optical memory. To realize this, a magnetic garnet with a large Faraday rotation angle and a moderately small extinction coefficient is required. In this study, we investigated the effect of Al or Ga substitution for the iron site of bismuth-substituted yttrium iron garnet (Bi/YIG) films on their magneto-optical properties. The Faraday rotation angle decreased with the amount of substitution, x, increase, for both Al- and Ga-substituted Bi/YIG, and a reversal of sign of rotation angle was only observed for Ga-substituted Bi/YIG, indicating a compensation composition. In the Al-substituted sample, due to small squareness, the residual Faraday rotation angle at zero magnetic field, |θ_R,res|, gradually decreased above x = 0.5, whereas in the Ga-substituted sample, the squareness ratio increased with increasing substitution up to x = 2.0, and thus showed a peak at x = 1.5. The Curie temperature and extinction coefficient were reduced with increasing substitution amount. As a result of a decrease in extinction coefficient, k, the high figure of merit, (|θ_R,res|/2πk) · λ was obtained around x = 1.5~1.9 for Ga and x = 2.1 for Al, while it was smaller than that of Bi/RIG we usually used. Full article

Greenhouse gas emissions from the energy sector are the main driver of global warming, which has led to an increase in the average surface temperature of the Earth by more than 1 °C above pre-industrial levels. Responding to the urgent need for energy transition, the countries of the European Union have set themselves the goal of achieving climate neutrality by 2050. The main objective of this article is to comprehensively assess the progress of decarbonization in the 27 European Union countries between 2004 and 2024, using an advanced multi-criteria model. The study used the quantitative Analytical Hierarchy Process (AHP) method to construct a multidimensional decision-making model. Eight energy technologies were evaluated through the prism of 13 criteria grouped into three pillars of sustainable development: economic (including technical), environmental, and social. Based on the weights of each criterion, estimated by a group of experts, a synthetic decarbonization index (DI) was calculated for each technology. In the next stage, a cumulative decarbonization index (CDI) was formulated for each country, reflecting the structure of its energy mix. The analysis revealed a fundamental divergence between conventional and zero-emission technologies. Renewable sources and nuclear energy have the highest positive impact on decarbonization (highest DI): hydropower (27.5), nuclear (20.7), wind (20.3). The lowest, unfavorable values of the index are characteristic of fossil fuels: oil (3.6), coal (3.9), and gas (4.8). The average cumulative decarbonization index (CDI) for the EU-27 rose from 14.0 in 2004 to 26.4 in 2024, demonstrating the effectiveness of the EU’s common policy. The leaders of the transition are countries with diversified, green mixes, such as Luxembourg (CDI = 40.4), Lithuania (CDI = 39.6), Portugal (38.5), Austria (36.9), and Spain (33.6). Despite starting from the lowest level in 2004 (CDI = 5.2), Poland recorded one of the most dynamic increases in 2024 (CDI = 17.7), mainly due to a reduction in the share of coal from 93% to 53.5%. The analysis confirms the effectiveness of the EU’s common climate and energy policy and demonstrates the usefulness of the methodology presented for a comprehensive assessment of the decarbonization process. The results indicate the need to further increase the share of zero-emission energy sources in the energy mix in order to achieve the objectives of the European Green Deal. The varying pace of transformation among Member States requires an individualized approach and support for countries with a historical dependence on fossil fuels. Full article