Search Results (113)

The present study focuses on the effect of doping KH560-modified cellulose nanocrystals (CNCs) on the electro-optical characteristics of polymer-dispersed liquid crystals (PDLCs). PDLC films were fabricated through the polymerization-initiated phase separation (PIPS) process and doped with CNC nanoparticles at various concentrations. At low concentrations, the CNCs at the interface, by virtue of their unique chiral characteristics, induce an orderly arrangement of liquid crystal molecules. Meanwhile, the interaction between the film’s fiber structure and the liquid crystal droplets brings about an augmentation in the arrangement efficiency. The excellent dispersion of CNCs diminishes the random alignment of liquid crystal molecules and mitigates light scattering. Additionally, it aids in the deflection of the liquid crystal director, facilitating the lubrication of the liquid crystals’ movement. It is remarkable that within the range of relatively lower CNCs doping concentrations, specifically from 0.005 wt% to 0.05 wt%, the PDLC films exhibit lower threshold and saturation voltages, faster response, enhanced viewing angle performance and higher contrast. Full article

Experimental tests on confined concrete specimens are essential to characterize the mechanisms activated under varying degrees of confinement. Such characterization is critical for understanding how full, partial, and non-uniform wrapping configurations influence strength and ductility enhancements. This study investigates the compressive behavior of concrete cylinders (160 mm × 320 mm) confined using full, partial, and non-uniform carbon fiber-reinforced polymers (CFRP) configurations. In the first phase, all wrapping schemes were applied with equivalent quantities of CFRP, enabling a direct performance comparison under material parity. The results indicate that non-uniform confinement (NUC) achieved approximately 15% higher axial strength than full confinement (FC2) using the same amount of CFRP. In the second phase, the NUC configuration was tested with 25% less CFRP material, yet the reduction in strength was limited to about 3%, demonstrating its superior efficiency. A new predictive model was developed to estimate peak axial stress and strain in CFRP-confined concrete cylinders. Compared to existing models, the proposed model demonstrated greater predictive accuracy (R² = 0.98 for stress and 0.91 for strain) and reduced error metrics (RMSE and scatter index). ANOVA confirmed the statistical significance of the model’s predictions (p < 0.00001 for stress, p = 0.002 for strain). These findings highlight the performance advantages and material efficiency of non-uniform CFRP confinement and support the utility of the proposed model as a practical design tool for developing advanced confinement strategies in structural engineering. Full article

Cellulose nanofiber (CNF) treatments can enhance the structure and performance of regenerated cellulose fibers. This study investigates the effects of CNF treatment on the mechanical properties, water absorption behavior, and humidity dependence of regenerated cellulose fibers. Tensile testing demonstrated that CNF-treated fibers exhibit improved elasticity and reduced swelling in aqueous environments. Scanning electron microscopy revealed the adsorption of CNF components onto the fiber surfaces. Microbeam X-ray diffraction indicated structural differences between untreated and CNF-treated fibers, with the latter containing cellulose I crystals. Small-angle X-ray scattering revealed alterations in the internal fibrillar structure due to CNF treatment. FT-IR spectroscopy highlighted humidity-dependent variations in molecular vibrations, with peak intensities increasing under higher humidity conditions. Additionally, CNF treatment inhibited water absorption in high-humidity conditions, contributing to reduced expansion rates and increased elastic modulus during water absorption. Overall, CNF treatment enhanced both the mechanical strength and water resistance of regenerated cellulose fibers, making them suitable for advanced textile applications. This study provides valuable insights into the role of CNF-treated fibers in improving the durability and functional performance of regenerated cellulose-based textile. Full article

This study investigated the changes in protein composition and DNA content in damaged somatic nerves when exposed to insulin-like growth factor-1 (IGF-1). Using electrophoretic protein separation in polyacrylamide gel (PAG) and spectrophotometry, the transection was shown to be accompanied by a significant decrease in the quantitative content of total protein, certain protein fractions and DNA, both in the proximal and distal segments of the nerve conductor. Against the background of the intramuscular administration of IGF-1, intensive DNA synthesis and the protein composition stabilization of somatic nerves at the earlier post-traumatic stages were observed. By means of Raman scattering (RS-spectroscopy) and recording action potentials (APs), the enhanced recovery of the physicochemical condition of the nerve fiber membrane and its functional activity, indicating regeneration activation in the somatic nerves after damage, was revealed. IGF-1 was most likely to stimulate cytoskeleton protein synthesis through launching the mitogen-activated protein kinase signal pathway (MAPK/ERK), resulting in the increased expression of the genes related to the remyelination and functioning recovery of damaged nerve conductors. Full article

Background/Objectives: The work presented herein focused on the development and characterization of a transdermal caffeine platform fabricated from ultrathin micro- and submicron fibers produced via electrospinning. Methods: The formulations incorporated caffeine encapsulated in a polyethylene oxide (PEO) matrix, combined with various permeation enhancers. A backing layer made of annealed electrospun polycaprolactone (PCL) facilitated the lamination of the two layers to form the final multilayer patch. Comprehensive characterization was conducted, utilizing scanning electron microscopy (SEM) to assess the fiber morphology, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for chemical detection and to assess the stability of the caffeine, and differential scanning calorimetry (DSC) along with wide-angle X-ray scattering (WAXS) to analyze the physical state of the caffeine within the fibers of the active layer. Additionally, Franz cell permeation studies were performed using both synthetic membranes (Strat-M) and ex vivo human stratum corneum (SC) to evaluate and model the permeation kinetics. Results: These experiments demonstrated the significant role of enhancers in modulating the caffeine permeation rates provided by the patch, achieving permeation rates of up to 0.73 mg/cm² within 24 h. Conclusions: This work highlights the potential of using electro-hydrodynamic processing technology to develop innovative transdermal delivery systems for drugs, offering a promising strategy for enhancing efficacy and innovative therapeutic direct plasma administration. Full article

Fiber–aerogel composites have gained significant attention as high-performance thermal insulation materials due to their unique microstructure, which suppresses conductive, convective, and radiative heat transfer. At room temperature, silica aerogels in particular exhibit ultralow thermal conductivity (<0.02 W/m·K), which is two to three times lower than that of still air (0.026 W/m·K). Their brittle skeleton and high infrared transparency, however, restrict how well they insulate, particularly at high temperatures (>300 °C). Incorporating microscale fibers into the aerogel matrix enhances mechanical strength and reduces radiative heat transfer by increasing scattering and absorption. For instance, it has been demonstrated that adding glass fibers reduces radiative heat transmission by around 40% because of increased infrared scattering. This review explores the fundamental mechanisms governing radiative heat transfer in fiber–aerogel composites, emphasizing absorption, scattering, and extinction coefficients. We discuss recent advancements in fiber-reinforced aerogels, focusing on material selection, structural modifications, and predictive heat transfer models. Recent studies indicate that incorporating fiber volume fractions as low as 10% can reduce the thermal conductivity of composites by up to 30%, without compromising their mechanical integrity. Key analytical and experimental methods for determining radiative properties, including Fourier transform infrared (FTIR) spectroscopy and numerical modeling approaches, are examined. The emissivity and transmittance of fiber–aerogel composites have been successfully measured using FTIR spectroscopy; tests show that fiber reinforcement at high temperatures reduces emissivity by about 15%. We conclude by outlining the present issues and potential avenues for future research to optimize fiber–aerogel composites for high-temperature applications, including energy-efficient buildings (where long-term thermal stability is necessary), electronics thermal management systems, and aerospace (where temperatures may surpass 1000 °C), with a focus on improving the materials’ affordability and scalability for industrial applications. Full article

Post-processing plays a vital role in the determination of the final structures and properties of oriented materials. As a sustainable candidate of oil-based poly(ethylene terephthalate), biobased poly(ethylene 2,5-furandicarboxylate) (PEF) reflects great promise in green fiber, film, and packaging applications, but it undergoes poor stress-induced crystallization (SIC) under tensile deformation, necessitating a post-processing technique to improve its crystallinity and stability. Here, the structural evolution of pre-stretched PEF under post heating after uniaxial deformation was monitored by online synchrotron X-ray diffraction/scattering, differential scanning calorimetry, and ex situ infrared spectroscopy. The results delineate the significantly enhanced crystallization of pre-deformed PEF that happened far below its cold crystallization temperature. Through the isochronous analyses of the temperature-dependent evolution of mechanical response, the mesophase, crystal structure, orientation factor, chain conformation, and interchain ═C−H···O═C hydrogen bonding, the molecular mechanisms of microstructural transition and oriented crystallization of pre-drawn PEF under post heating were clarified. This research can enhance the understanding of PEF crystallization in an oriented state and provide guidelines on the structural design and technical control for processing high-performance PEF-based materials. Full article

Okara, the soybean residue from soy milk and tofu production, offers significant potential as a sustainable, fiber-rich ingredient for starch-based and gluten-free food systems. This study investigates the comparative effects of whole okara and its extracted dietary fiber (DF) on the retrogradation, rheological properties, and nanostructural organization of rice starch (RS) gels. Rice starch suspensions were blended with 5–20% (dry basis) of either whole okara or DF, thermally gelatinized, and analyzed using dynamic rheology, synchrotron-based Wide-Angle X-ray Scattering (WAXS), and Fourier Transform Infrared (FTIR) spectroscopy. DF markedly reduced the gelation temperature and enhanced storage modulus (G′), indicating earlier and stronger gel network formation. WAXS analysis showed that DF more effectively disrupted long-range molecular ordering, as evidenced by suppressed crystallinity development and disrupted molecular ordering within the A-type lattice. FTIR spectra revealed intensified O–H stretching and new ester carbonyl bands, with progressively higher short-range molecular order (R_1047/1022) in DF-modified gels. While whole okara provided moderate retrogradation resistance and contributed to network cohesiveness via its matrix of fiber, protein, and lipid, DF exhibited superior retrogradation inhibition and gel stiffness due to its purity and stronger fiber–starch interactions. These results highlight the functional divergence of okara-derived ingredients and support their targeted use in formulating stable, fiber-enriched, starch-based foods. Full article

Hard carbon anodes are promising for sodium-ion batteries due to their low cost and high reversible capacity. However, the long-term Na⁺ (de)intercalating process destroys the structure of the two-phase interface between the electrode and electrolyte, impairing cycling stability. In this paper, a few-layer graphene (FLG)-coated hard carbon fiber composite is constructed. A uniform graphene encapsulation is confirmed by synchrotron small-angle X-ray scattering and transmission electron microscopy technologies. Post-cycling observation reveals FLG participation in forming a hybrid solid electrolyte interphase (SEI). At a proper concentration, the FLG with a small specific surface area and pore size characteristics is well matched in the SEI. The FLG-integrated SEI not only mitigates volume expansion but also enhances ion conductivity through its oxygen-rich functional groups. As a result, the composite structure maintains 98.2% capacity retention after 100 cycles and reaches 164 mAh g⁻¹ at 1000 mA g⁻¹, compared to 97 mAh g⁻¹ for the pristine hard carbon. This work demonstrates that FLG coating simultaneously stabilizes the interfacial chemistry and improves the ion transport, offering a practical pathway to advance hard carbon anodes for high-performance sodium-ion batteries. Full article

This work presents a high-speed hybrid communication system integrating Underwater Optical Wireless Communication (UOWC), Multimode Fiber (MMF), and Free-Space Optics (FSO) channels, leveraging Orbital Angular Momentum (OAM) beams for enhanced data transmission. A Photodetector, Remodulate, and Forward Relay (PRFR) is employed to enable wavelength conversion from 532 nm for UOWC to 1550 nm for MMF and FSO links. Four distinct OAM beams, each supporting a 5 Gbps data rate, are utilized to evaluate the system’s performance under two scenarios. The first scenario investigates the effects of absorption and scattering in five water types on underwater transmission range, while maintaining fixed MMF length and FSO link. The second scenario examines varying FSO propagation distances under different fog conditions, with a consistent underwater link length. Results demonstrate that water and atmospheric attenuation significantly impact transmission range and received optical power. The proposed hybrid system ensures reliable data transmission with a maximum overall transmission distance of 1125 m (comprising a 25 m UOWC link in Pure Sea (PS) water, a 100 m MMF span, and a 1000 m FSO range in clear weather) in the first scenario. In the second scenario, under Light Fog (LF) conditions, the system achieves a longer reach of up to 2020 m (20 m UOWC link + 100 m MMF span + 1900 m FSO range), maintaining a BER ≤ 10⁻⁴ and a Q-factor around 4. This hybrid design is well suited for applications such as oceanographic research, offshore monitoring, and the Internet of Underwater Things (IoUT), enabling efficient data transfer between underwater nodes and surface stations. Full article

This investigation presents an overview of various optical biosensors utilized for the detection of cancer cells. It covers a comprehensive range of technologies, including surface plasmon resonance $\left(SPR\right)$ sensors, which exploit changes in refractive index $\left(RI\right)$ at the sensor surface to detect biomolecular interactions. Localized surface plasmon resonance $\left(LSPR\right)$ sensors offer high sensitivity and versatility in detecting cancer biomarkers. Colorimetric sensors, based on color changes induced via specific biochemical reactions, provide a cost-effective and simple approach to cancer detection. Sensors based on fluorescence work using the light emitted from fluorescent molecules detect cancer-specific targets with specificity and high sensitivity. Photonics and waveguide sensors utilize optical waveguides to detect changes in light propagation, offering real-time and label-free detection of cancer biomarkers. Raman spectroscopy-based sensors utilize surface-enhanced Raman scattering $\left(SERS\right)$to provide molecular fingerprint information for cancer diagnosis. Lastly, fiber optic sensors offer flexibility and miniaturization, making them suitable for in vivo and point-of-care applications in cancer detection. This study provides insights into the principles, applications, and advancements of these optical biosensors in cancer diagnostics, highlighting their potential in improving early detection and patient outcomes. Full article

A high-sensitivity surface plasmon resonance (SPR) dual-parameter sensor based on photonic crystal fiber (PCF) is proposed for simultaneous measurement of magnetic field and temperature. The grooves on the right and upper sides of the PCF, serving as distinct detection channels, are filled with magnetic fluid and polydimethylsiloxane, respectively, enabling high-sensitivity detection of magnetic field and temperature. The structure parameters and sensing characteristics of the proposed sensor are investigated based on the finite element method. Numerical results indicate, within the wavelength range of 850–1050 nm, that the sensor achieves a high magnetic field sensitivity of 86 pm/Gs under x-polarization in the range of 100–600 Gs, and exhibits a temperature sensitivity of −2.63 nm/°C under y-polarization within the temperature range of 20–40 °C. Furthermore, the detection precision and applicability of the sensor in actual measurement applications could be further enhanced in the future by introducing surface-enhanced Raman scattering technology. Full article

Thermal insulation layers between batteries are an effective way to reduce the propagation of thermal runaway in lithium-ion batteries. A flexible composite sandwich structure material has been designed for thermal insulation, featuring mica rolls (MRs) as the protective layers and a ceramic fiber felt (CFF) as the core layer. Experimental and numerical simulations demonstrate that at a hot-surface temperature of 900 °C, the cold-surface temperature of the sandwich structure with a 0.3 mm MR and 3.0 mm CFF layer is only 175 °C, which is significantly lower than the 350 °C observed for a standalone 3.0 mm CFF layer under the same conditions. The MR layer effectively shields against flames and impedes heat transfer, while the porous structure of the CFF, enhanced by microcracks and holes, increases heat transfer paths and scatters radiated heat. This synergistic interaction between the MR and CFF layers results in a superior thermal insulation performance. The findings highlight the potential of this sandwich structure in improving the safety and thermal management of lithium-ion batteries and other energy storage systems. Full article

The electrical conduction mechanism of PEDOT:PTSA thermoelectric conversion material supported on PET fiber was investigated with varying PTSA concentrations. Raman analysis revealed that an increasing PTSA concentration promoted transformation from a benzoid to a quinoid structure in PEDOT chains, reaching saturation in higher concentrations. All samples exhibited p-type behavior, with Seebeck coefficients ranging from 0.9 to 2.7 mV/K. The temperature dependence of electrical conductivity showed that conductivity and activation energy exhibited extreme values with increasing PTSA concentration, correlating with the saturation of quinoid structure transformation. This behavior suggests that PTSA serves dual roles: at lower concentrations, it enhances electrical conductivity through chemical doping, increasing carrier concentration and mobility via quinoid structure formation; at higher concentrations, excess PTSA induces carrier scattering without contributing to chemical doping, thereby reducing conductivity. These findings indicate that the thermoelectric properties of PEDOT:PTSA on PET fiber are governed by the balance between chemical doping effects and carrier scattering mechanisms, which are both influenced by PTSA concentration. Full article

The generation of unwanted higher-order Raman effects is the main factor restricting the power scaling of Raman fiber amplifiers (RFAs). This phenomenon arises from an interplay of physical processes, including stimulated Raman scattering (SRS), four-wave mixing (FWM), and the intricate temporal and spectral dynamics. Tapered fibers have demonstrated excellent nonlinear effects suppression characteristics due to the varying core diameter along the fiber, which is widely used in ytterbium-doped fiber lasers. In this paper, a comprehensive numerical investigation is conducted on the core-pumping tapered fiber RFAs considering Raman-assisted FWM. The higher-order Raman power in the tapered fiber is always kept at a low level, showing a weak Raman-assisted FWM effect. A numerical investigation is conducted to study the impact of the tapering ratio, the lengths of the thin part, tapered region, and thick part on the higher-order Raman threshold of RFAs. Furthermore, the impact of phase mismatch variations caused by changes in the seed wavelength, on the output signal power and nonlinear effects is analyzed. This paper presents, for the first time, a study on core-pumped RFAs using tapered fibers, providing a novel perspective on enhancing the power of RFAs. Full article