Search Results (91)

FDO’s wide boiling range and complex composition hinder controlled synthesis of high-performance mesophase pitch. Here, FDO was separated into light, middle, and heavy narrow fractions by vacuum distillation. Multi-scale characterization traced molecular evolution and mesophase development. The light fraction consists of three-ring aromatics with short alkyl side chains and shows the lowest reactivity, yielding limited condensation and poor stacking with isotropic regions and dispersed spheres. The middle fraction contains four-ring aromatics with moderately extended chains, exhibiting enhanced reactivity and undergoing nucleation, growth, coalescence, and disintegration of mesophase spheres. However, insufficient volatiles restrict shear orientation, forming a mosaic texture. The heavy fraction has four-ring aromatics with the longest alkyl chains and the lowest substitution degree, giving the highest reactivity. During thermal cracking, long chains release abundant radicals and volatiles; directional escape generates shear, promoting rapid growth and ordered alignment of aromatic lamellae. At 440 °C for 12 h, this fraction yields high-quality mesophase pitch with small-domain texture, a low softening point (295 °C), and high anisotropic content (98.8%). The pitch shows excellent spinnability, and derived carbon fibers (tensile strength ~1.45 GPa, modulus ~151 GPa) outperform a commercial reference processed under identical conditions. This study reveals molecular-level regulation of mesophase evolution by narrow fraction structures. Full article

Objectives: Alzheimer’s disease (AD) is associated with impaired adult hippocampal neurogenesis (AHN). This study aimed to establish an in vitro model of Aβ_1–42 oligomer-damaged neural stem cells (NSCs) and to employ the 5×FAD mouse model of AD in vivo, and to evaluate the therapeutic effects of brain-derived neurotrophic factor-loaded hyaluronic acid hydrogel (BDNF-HA gel) on AHN. Methods: In vitro, BDNF-HA gel was co-cultured with Aβ_1–42 oligomer-impaired NSC spheres and evaluate NSC proliferation, migration, and differentiation. In vivo, BDNF-HA gel was infused intracerebroventricularly into 5×FAD mice. Using BrdU labeling, immunofluorescence, anterograde transsynaptic viral tracing, and behavioral tests, we assessed the effects of BDNF-HA gel on adult neurogenesis, newborn neuron integration into memory circuits, and cognitive function. Results: In vitro, BDNF-HA gel attenuated Aβ_1–42-induced NSC apoptosis, restored proliferation and migration, promoted differentiation into neuroblasts, newborn neurons, and oligodendrocytes, and alleviated mitochondrial depolarization and loss of mitochondrial mass. In vivo, despite the absence of significant Aβ plaques reduction in 5×FAD mice, BDNF-HA gel markedly enhanced NSC proliferation and neurogenesis in the subventricular zone (SVZ) and subgranular zone (SGZ). Behavioral tests further revealed significant improvements in object recognition, spatial working memory, and spatial reference memory. Conclusions: BDNF-HA gel can effectively counteract the toxic microenvironment induced by Aβ oligomers, promoting NSC proliferation, migration, and differentiation into neurons. Without altering the Aβ burden, it significantly enhances adult neurogenesis and rescues cognitive deficits in AD mice. Full article

The Ozone Monitor Suite-Nadir (OMS-N) onboard the FY-3F satellite is a key payload for global atmospheric ozone and trace gas detection. The data quality depends on the accuracy of ground calibration. This study presents a systematic ground calibration of OMS-N. The instrument operates over 250–500 nm, with a spatial resolution of 7 × 7 km² and a spectral resolution of 0.5–1 nm. Radiometric calibration was performed using an integrating sphere, spectral calibration using a tunable laser, and geometric calibration using a precision turntable. All tests were conducted under controlled environmental conditions (20 ± 3 °C and 50% ± 10% humidity). The absolute radiometric calibration uncertainty was below 2.33% for UV1/UV2 and 1.69% for VIS, with relative uncertainties ≤1.84%. The spectral wavelength error was ≤0.01 nm for the VIS channel and ≤0.03 nm for the UV1/UV2 channels, and the geometric positioning uncertainty was better than 0.1 pixels. All performance indicators met or exceeded the design requirements. These results provide technical support for the quantitative application of OMS-N data in atmospheric monitoring and establish a reference framework for the ground calibration of similar ultraviolet hyperspectral instruments. Full article

This article posits that Islamic fairy tales function as a mystical bridge of speech, a discursive passage that, within the siyasatnama tradition, summons the subject toward ethico-political responsibility, while in Sufi narrative, it carries the seeker beyond the limits of language toward a transformative silence. Reading Indo-Persian and Ottoman siyasatnama texts alongside the Sufi classics of Attar and Rumi, the article traces this movement across both traditions. In the siyasatnama context, the fairy tale translates divine commandments into a set of virtues, such as justice, mercy, and compassion, that regulate the conduct of both ruler and subject, framing governance as an ethical response to a sacred truth. Conversely, in Sufi narrative, the fairy tale operates within a similar ethical–pedagogical grammar but directs the subject toward a fundamentally different ontological end: The dissolution of the self. Here, speech becomes a threshold to be crossed and narrative a cage to be surrendered, allowing the seeker to enter the silence in which divine love is realized. Ultimately, the article proposes that mystical transcendence does not signify a withdrawal from the ethical sphere; instead, it constitutes its most profound enactment, manifested either through the responsible exercise of power or its radical renunciation in love. Full article

This study investigates the interaction of commercially available alumina (Al₂O₃) particles with humic acid salt (HA–salt) and the subsequent impact of HA-coating on uranium adsorption. Alumina particles were coated by immersion in HA–salt solutions of varying concentrations (0.01–1.0 g/L). Following, batch adsorption experiments were conducted using U-232 at ultra-trace levels, to evaluate distribution coefficients (K_d) at pH 4 and 7, and depleted uranium (DU) at elevated concentrations to assess maximum adsorption capacities (q_max), temperature dependence, and kinetics. HA-coating significantly enhanced uranium uptake, particularly at neutral pH for ultra-tracer levels, where the deprotonation of HA carboxylic groups favors inner-sphere complex formation. At pH 3 (and at relatively high concentrations), the results showed that adsorption appears to be due to the formation of outer-sphere complexes, with q_max values for particles with the highest HA–salt loading reaching up to 0.16 ± 0.02 mol/kg. Temperature studies indicated endothermic adsorption, while kinetic data revealed a two-step mechanism for HA-coated particles, involving most probably initial outer-sphere complexation followed by gradual inner-sphere complex formation. These findings highlight the critical role of HA surface modification in enhancing the affinity of alumina towards uranium, with implications for radionuclide mobility in the geosphere and the development of efficient sorbents for uranium-contaminated water treatment. Full article

This investigation provides a comprehensive analytical framework for the topological morphology and global convergence dynamics governing a specific family of sixth-order iterative schemes designed for nonlinear equations with multiple roots. By invoking a Möbius conjugacy transformation upon the specialized polynomial class $f\left(z\right)={\left((z-p)(z-q)\right)}^m$, we project the iterative sequence onto the Riemann sphere $\widehat{\mathbb{C}}$, effectively recasting the algorithm as a discrete complex dynamic system. The core of this study lies in the bifurcation analysis of the associated parameter space. We meticulously chart the stability manifolds, tracing the evolution of critical orbits to distinguish between regions of predictable convergence and those characterized by chaotic instability. By examining the iterative methods generated by these rational endomorphisms, the research unveils the intricate fractal boundaries that delineate the basin of attraction, offering a profound insight into the structural robustness of higher-order methods. In the dynamical plane, the geometry of the basins of attraction is scrutinized to evaluate the robustness of the numerical flow and its sensitivity to the configuration of weight functions. By analyzing the fractal complexity of the boundaries within these basins, we provide a detailed characterization of the iterative morphology and its global reliability. The analytical findings are supported by high-resolution graphical representations and comparative numerical data, illustrating the superior performance and structural integrity of the proposed methods in solving nonlinear problems. Full article

The objective of this study was to compare subjective manifest refraction with wavefront-based automated refraction using iTrace (ray tracing) and LadarWave (Hartmann–Shack) in eyes implanted with two enhanced monofocal intraocular lenses (IOLs) and a standard aspheric monofocal IOL, emphasizing agreement and refractive variability across optical designs. This retrospective cohort included 84 eyes from 42 patients implanted with Tecnis Eyhance (DIB00), RayOne EMV (RAO200E), or Tecnis ZCB00 IOLs. Postoperative evaluation (1–3 months) included uncorrected and corrected distance visual acuity and subjective manifest refraction, followed by automated refraction with iTrace and LadarWave. Outcomes were sphere, cylinder, and spherical equivalent (SE). Agreement was assessed using mean signed difference, mean absolute error, root mean square error, Bland–Altman limits of agreement, proportions within clinically relevant thresholds, and vector astigmatism (J0, J45). Linear mixed-effect modeling evaluated SE differences across methods and IOL types while accounting for within-subject correlation. Subjective SE differed among IOLs (p = 0.027), with RAO200E more myopic than ZCB00 (−0.20 ± 0.32 D vs. −0.08 ± 0.44 D, p = 0.035). Automated refraction showed greater variability and poorer agreement in enhanced monofocal IOLs, particularly for cylinder and SE, with wider limits of agreement and fewer eyes within ±0.50 D compared with ZCB00. In mixed-effect contrasts (three-method repeated-measures model), iTrace and LadarWave showed a consistent myopic bias versus manifest refraction in DIB00 and RAO200E, whereas in ZCB00 the iTrace–manifest difference was not significant and LadarWave retained a significant myopic bias. Enhanced monofocal IOLs exhibit reduced agreement between wavefront-based automated and subjective manifest refraction compared with a standard aspheric monofocal IOL. Manifest refraction remains essential for postoperative assessment, and automated measurements should be interpreted as complementary, particularly in IOL designs that modify aberrations. Full article

Copper and nickel ions play pivotal, albeit distinct, roles as essential trace elements in living systems, and primarily serve as co-factors for a range of enzymes. However, as with all trace metal ions, excessive concentrations can exert adverse toxicological properties. Interestingly, the incorporation of these in cell culture media can establish novel chemical interactions, with their speciation status markedly influencing characteristics, including cell maturation, and cellular uptake mechanisms. Thus, the primary objective of this study was to investigate and determine the speciation status (i.e., complexation) of nickel(II) and copper(II) ions by biomolecules present in RPMI 1640 mammalian cell culture medium using virtually non-invasive high-resolution proton NMR analysis, an investigation of much relevance to now routine studies of their toxicological actions towards cultured cells. Samples of the above aqueous culture medium were ¹H NMR-titrated with increasing added concentrations of 71–670 µmol/L Ni(II)(aq.), and 0.71–6.7, 7.1–67 and 71–670 µmol/L Cu(II)(aq.), in duplicate or triplicate. ¹H NMR spectra were acquired on a JEOL ECZ-600 spectrometer at 298 K. Results demonstrated that addition of increasing concentrations of Ni(II) and Cu(II) ions to the culture medium led to the selective broadening of a series of biomolecule resonances, results demonstrating their complexation by these agents. The most important complexants for Ni(II) were histidine > glutamine > acetate ≈ methionine ≈ lysine ≈ threonine ≈ branched-chain amino acids (BCAAs) > asparagine ≈ aspartate > tyrosine ≈ tryptophan, whereas for Cu(II) they were found to be histidine > glutamine > phenylalanine ≈ tyrosine ≈ nearly all remaining aliphatic metabolites (particularly the wealth of amino acids detectable) > 4-hydroxyphenylacetate (trace culture medium contaminant), in these orders. However, Cu(II) had the ability to influence the linewidths of these signals at much lower added levels (≤7 µmol/L) than that of Ni(II), the broadening effects of the latter occurring at concentrations which were approximately 10-fold greater. Virtually all of these added metal ion-induced resonance modifications were, as expected, reversible on addition of equivalent or excess levels of the chelator EDTA. From this study, changes in the co-ordination sphere of metal ions in physiological environments can give rise to marked modifications in their physicochemical properties (e.g., redox potentials, electronic charges, the potential catalytic generation of reactive oxygen species (ROS), and cell membrane passages). Moreover, given that the above metabolites may also function as potent hydroxyl radical (^●OH) scavengers, these findings suggest that generation of this aggressively reactive oxidant directly from Cu(II) and Ni(II) ions in physiologically-relevant complexes may be scavenged in a ‘site-dependent’ manner. This study is of further relevance to trace metal ion research in general since it enhances our understanding of the nature of their interactions with culture medium biomolecules, and therefore provides valuable information regarding their overall chemical and biological activities, and toxicities. Full article

Among the important differential equations on a Riemannian space $\left(M,g\right)$ of dimension n are the static perfect fluid equation (SPFE), namely $fRic-Hess\left(f\right)={\displaystyle \frac{1}{n}}\left(f\tau -\Delta f\right)g$, and the Fischer–Marsden equation (FME), namely $\left(\Delta f\right)g+fRic=Hess\left(f\right)$, where $Ric$ is the Ricci tensor, $\tau$ is the scalar curvature of $\left(M,g\right)$ and $Hess\left(f\right)$ and $\Delta f$ are the Hessian and the Laplacian of the smooth function f. The trace of the FME is $\Delta f=-{\displaystyle \frac{\tau }{n-1}}f$, which we call the TFME, and if we combine the TFME with the SPFE, we observe that it reduces to the FME. Thus, in the presence of the TFME on the Riemannian space $\left(M,g\right)$ the fundamental differential equations SPFE and FME are equivalent. In this article, we consider the presence of the TFME on a Riemannian space $\left(M,g\right)$ and study its impact on the Riemannian space $\left(M,g\right)$. The importance of this study follows from the fact that results obtained for Riemannian spaces admitting solutions to the TFME automatically are generalizations of corresponding results on spaces admitting solutions to the FME. First, we show that for a connected and compact Riemannian space $(M,g)$, $dimM=n>1$, with scalar curvature $\tau$ that admits a nontrivial solution f to the TFME, with the Ricci operator Q satisfying $Q\left(\nabla f\right)={\displaystyle \frac{\tau }{n}}\nabla f$, and with the integral of $Ric\left(\nabla f,\nabla f\right)$ having a suitable lower bound, it is necessary and sufficient that $(M,g)$ is an n-sphere ${\mathbf{S}}^n\left(c\right)$. In addition, we show that a compact and connected space $(M,g)$, $dimM=n>1$, admits a nontrivial solution f to the TFME such that the scalar curvature $\tau$ satisfies $(n-1)c<\tau \le n(n-1)c$ for some constant $c>0$, and the Ricci curvature $Ric(\nabla f,\nabla f)$ is bounded below by $(n-1)c$, if and only if $(M,g)$ is an n-sphere ${\mathbf{S}}^n\left(c\right)$. Finally, it is shown that a connected and compact Riemannian space $(M,g)$, $dimM=$ $n>1$, with constant scalar curvature $\tau$ admits a nontrivial solution f to the TFME, with the Ricci operator Q satisfying $Q\left(\nabla f\right)={\displaystyle \frac{\tau }{n}}\nabla f$, if and only if $(M,g)$ is the sphere ${\mathbf{S}}^n\left(c\right)$. Full article

In this work, we report a compact and highly sensitive photoacoustic spectroscopy (PAS) system based on a cone–sphere coupled photoacoustic cell (CSC-PAC) for real-time detection of trace acetylene (C₂H₂) dissolved in transformer oil. The sensing module integrates a conical resonator with a spherical cavity, forming a hybrid structure that effectively enhances photoacoustic confinement and energy coupling efficiency. Finite element thermo-viscoelastic simulations were employed to optimize the cavity geometry and resonance conditions for maximum signal generation. Experimental results demonstrate a strong linear correlation between the photoacoustic signal and C₂H₂ concentration (R² > 0.999), with a sensitivity of 2.45 µV·ppm⁻¹. Allan deviation confirms a detection limit of 18.6 ppb is achieved at a 400 s averaging time, confirming excellent system stability. The miniaturized light-acoustic spectroscopy sensor, with a total volume of 7.5 mL and a rapid response time of 25.5 s, provides a high-performance and field-deployable platform for on-site monitoring of high-voltage power equipment and other industrial applications. Full article

High-nitrogen organic chemical wastewater is characterized by high chemical oxygen demand (COD_Cr), poor biodegradability, and toxic nitrogenous organics, posing significant challenges for conventional biological treatment. In this study, a dual-electrical treatment strategy integrating an electromagnetic Fenton (EM-Fenton) pretreatment unit with a three-dimensional biofilm electrode reactor (3D-BER) is proposed. The EM-Fenton system used iron–carbon fillers under electric and magnetic fields to generate hydroxyl radicals (·OH), enabling efficient oxidation of nitro-aromatic compounds and the conversion of organic nitrogen into NO₃⁻-N, while reducing Fe²⁺ input and iron sludge generation. Subsequently, the 3D-BER, filled with Fe₃O₄/Mn₃O₄-modified polyurethane spheres, facilitated autotrophic denitrification and phosphorus removal through enhanced extracellular electron transfer and trace hydrogen (H₂) release. Experimental results demonstrated that the EM-Fenton system achieved COD_Cr and NH₄⁺ removal rates of over 40% and 14%, respectively, under optimal HRT. The 3D-BER further improved removal efficiencies, with TN and TP reductions exceeding 80% and 81%, respectively, significantly outperforming the control groups. Microbial analysis revealed the enrichment of functional genera, such as Pararhodobacter and Thauera, and the upregulation of key denitrification pathways. This coupled system demonstrated high treatment efficiency, process synergy, and microbial selectivity, offering a promising approach for the advanced treatment of high-nitrogen industrial wastewater. Full article

This paper proposes a reconstruction framework for estimating the far-field (FF) radiation patterns of large, heavy, or non-rotatable wireless-enabled systems. The method combines a tilted orbital sampling (ToS) strategy with sparse spherical harmonic (SH) expansion, compressed sensing (CS), and convex optimization (CO), thereby linking a mechanically constrained acquisition scheme with a mathematically efficient recovery process. The purpose of this integration is not only to reduce the number of measurements but also to retrieve the radiation information most relevant to Internet of Things (IoT) devices and bulky equipment that cannot be easily rotated within anechoic chambers. The framework is validated on two representative cases: a canonical half-wave dipole and a commercial Wi-Fi-enabled device. In the latter and more challenging case, accurate reconstruction is achieved with fewer than 30 SH coefficients and using less than 20% of the measurements required by a conventional full-sphere scan, with the normalized root-mean-square error remaining below 5%. Although inaccessible angular regions may be partially uncharacterized, such directions are of minor relevance for the intended operational coverage. The resulting SH-based representation can be seamlessly integrated into ray-tracing propagation simulators and electromagnetic optimization workflows, enabling efficient and application-oriented OTA characterization under realistic chamber constraints. Full article

Particularly in the post-October 7 period, the use of the word or utterance “Jew,” or “Jewish,” is (once more) a pertinent example for understanding conflict, geopolitics, and the relation between religion and politics. Based on my ongoing ethnographic work, which explores how this is experienced in the Greek university world, I provide here a mode of understanding dominant ideological and/or intellectual origins of people’s stances in the academic workplace when they use, or encounter, the “Jewish” signifier. I do not provide ethnographic material as much as I provide a context for understanding the ethnography of a specific academic–intellectual universe. As a particular public sphere, the academic workplace has its own attitudes and strategies for handling ideological and politico-philosophical differences within itself. This condition, I suggest, can accommodate a felt predicament among interlocutors, colleagues, and other interrelated actors, as has been the case particularly during the last couple of years. The conflict in the Middle East brings the geopolitical into the classroom and onto campus in ways that may reconfigure and unsettle power relations and sentiment in the community. I trace the origins of this predicament through a synoptic genealogical trajectory from the 1960s to the present. Full article

This study interrogates the semiotic destabilization of rural cultural symbols in China’s burgeoning short video sphere, with particular focus on the discursive reconstruction of “tǔ wèi” labeling. This paper, through semantic tracing and content analysis, combined with empirical data from over 130,000 “tǔ wèi” videos on Douyin (Tik Tok), categorizes the “tǔ wèi” content into two major styles: the novelty-hunting and ugliness-seeking style and the rural original ecological style. It also compares the differences in popularity, quality, and value orientation between the two. The research finds that the semantic segmentation of the “tǔ wèi” label is rooted in clash of civilizations and the urban–rural dichotomy, as well as the promotion of the traffic logic and symbol abuse of short video platforms. This segmentation has exacerbated the stigmatization of Chinese farming culture and weakened cultural confidence. It is suggested that efforts should be made from three aspects: deep exploration of indigenous “tǔ” cultural resources, optimization of algorithm recommendation mechanisms, and reconstruction of discourse contexts, to promote the semantic return of the “tǔ wèi” label and consolidate cultural subjectivity. Full article

The use of advanced adaptive algorithms in Augmented Reality (AR) systems works to advance spatial skills with valuable relevance in many professional spheres by providing personalized feedback in an immersive environment. This study combines Bayesian Knowledge Tracing (BKT) and Human Plausible Reasoning (HPR) to design an AR system that can adapt to dynamic simulations with quantitative as well as qualitative cognitive methodologies. The system records a broad range of interactions from users, such as objects being rotated, changes in viewing perspective, and time spent on tasks, which are later analyzed through probabilistic updates with respect to skill building along with rule-based reasoning for determining behavioral patterns. Results from an in-depth case study show that the BKT module properly tracks improvement in spatial skills, while the HPR application highlights suboptimal approaches that hide underlying conceptual understanding. The adaptive system used then provides metacognitive hints that adjust by optimizing task difficulty levels, leading to improved student performance compared to standard non-adaptive AR techniques. Results show that using BKT and HPR in an AR environment not only enables accurate task performance but supports greater insight in approach strategies, leading to better and transferable spatial skills. Full article