Search Results (11,943)

A review of the recent research work on high-power and high-speed (HPHS) Ge-on-Si photodiode design is presented, using Silicon Photonics (SiPh) technology, suitable for Radio-over-Fiber base station schemes. The Photodiode (PD) principle of operation, its structure for high RF photogenerated power, and the achieved PD wide bandwidth are presented. Then, the PD equivalent circuit models are introduced to obtain the PD S-parameters and operating bandwidth, such that efficient power coupling to mmWave loads is realized. Then, the PD theoretical transit-time and RC-time bandwidths are presented, and the PD photocurrent behavior against input optical power, and the optical signal manipulation techniques to improve the PD performance are also presented. After that, the impedance matching techniques between the PD output impedance and antenna input impedance are presented. Finally, recent photonic mmWave antenna designs are introduced. Full article

Meat analog manufacturing via high-moisture extrusion technology is a complex process wherein the properties of protein materials constitute a critical determining factor. In this study, we enhanced the fiber structure properties of high-moisture extruded peanut protein-based meat analogs by incorporating different starches (cassava starch, acetyl distarch phosphate [ADSP], and hydroxypropyl starch) to address challenges in water retention, emulsification, and digestibility. The impact of the starch content (0, 3, 6, 9, 12%) was assessed using low-field nuclear magnetic resonance, ultraviolet/fluorescence spectroscopy, differential scanning calorimetry, sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and functional tests. Compared with controls without starch, adding 6% ADSP significantly improved the water retention by forming a dense, charged network, reducing T_2b (0.37 ms) and T₂₂ (175.30 ms). ADSP (12%) enhanced the emulsification (activity index 10.28 m²/g, stability index 75%); the cassava starch (12%) increased the in vitro protein digestibility to 83% due to amylopectin degradation. Hydroxypropyl starch (6%) elevated the thermal stability (peak temperature 125.71 °C) by forming a viscous protective matrix (p < 0.05). Ultraviolet and fluorescence spectra indicated protein–starch interactions, with ADSP inducing the most pronounced conformational changes. This study demonstrated that the starch type and concentration critically modulate protein–starch interactions, offering guidance for enhancing the quality of meat analogs. Full article

Poly(3-hydroxybutyrate) is a biobased and biodegradable polymer, produced via bacterial fermentation and characterized by an isotactic structure and mechanical properties similar to those of polyethylene and polypropylene. However, its brittleness—due to high crystallinity (~70%) and thermal degradation, starting at a temperature range of 180–190 °C near its melting point (175 °C)—makes its processing difficult and limits its applications. Most recent studies on modifying P3HB involved solution casting, typically using chloroform, which raises sustainability concerns. In this study blends of isotactic poly(3-hydroxybutyrate) (i-P3HB) with atactic poly(3-hydroxybutyrate) (a-P3HB) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) were prepared through solvent-free extrusion, and the thermal and mechanical properties of these blends were characterized. The obtained blends showed an extended processing window with reduced processing temperatures (150–160 °C), which were significantly lower than the onset of the decomposition temperature of i-P3HB, thereby avoiding thermal degradation. Furthermore, the crystallinity of these blends could be varied between 17 and 70%, depending on the polymer ratio, which allows for tailormade materials with tunable mechanical properties and an elongation at break up to 600%. Based on the results, the obtained blends in this study are promising candidates for various applications and processing techniques, such as injection molding, extrusion, and fiber spinning, offering a sustainable alternative to conventional plastics. Full article

Background/Objectives: Spinal diffusion tensor imaging (sDTI) remains a challenging method for the selective evaluation of key anatomical structures, like pyramidal tracts (PTs) and dorsal columns (DCs), and for reliably quantifying diffusion metrics such as fractional anisotropy (FA), radial diffusivity (RD), mean diffusivity (MD), and axial diffusivity (AD). This prospective, single-center study aimed to assess the reproducibility, robustness, and reliability of an optimized axial sDTI protocol, specifically intended for long fiber tracts. Methods: We developed an optimized Stejskal–Tanner sequence for high-resolution, axial sDTI of the cervical spinal cord at 3.0 T. Using advanced standardized evaluation and post-processing methods, we estimated DTI values for PTs, DCs, and AHs at the level of the second cervical vertebra. Reliability was evaluated through repeated measurements in 16 healthy volunteers and by comparing results from two 3.0 T scanners (Magnetom Skyra and Magnetom Prisma, Siemens Healthineers, Erlangen, Germany). Reproducibility was assessed using paired t-tests, intraclass correlation coefficients (ICCs), Bland–Altman analysis, and coefficients of variation (CVs). Results: The optimized sDTI protocol demonstrated high consistency for FA between test–retest sessions and across scanners. For the Skyra, the DC region showed the highest reliability (average ICC = 0.858) followed by the PT region (average ICC = 0.789). On the Prisma, the PT region reached an average ICC of 0.854, with the DC region at 0.758. Pooled inter-scanner data indicated good-to-excellent agreement, particularly in the PT region (average ICC = 0.860). FA CVs remained low (<10%) across all regions and scanners. RD showed good-to-excellent ICC values for PTs and DCs (average ICC for Skyra 0.642 and 0.769 and 0.926 and 0.830 for Prisma, respectively) but showed a higher CV between 14.6 and 19.4% for these two scanners. Conclusions: Improved sDTI offers highly reproducible FA measurements for all metrics with scanner independence, supporting its potential as a robust tool for detecting and monitoring spinal cord pathologies. Full article

Background/Objectives: Dyslipidemia is a prevalent metabolic disorder closely linked to cardiovascular complications and muscular pathologies, often managed using statins such as simvastatin. However, statin-induced myopathy remains a significant treatment-limiting side effect, necessitating the exploration of safe, natural alternatives. Spirulina platensis, a phytochemical-rich marine-derived cyanobacterium, has emerged as a promising bioactive nutraceutical with potent antioxidant and anti-inflammatory properties. This study evaluated the comparative effects of Spirulina platensis and simvastatin in attenuating dyslipidemia-induced skeletal muscle injury in adult male albino rats. Methods: Forty animals were allocated to the control and high-fat diet (HFD) groups. After 4 weeks, the dyslipidemic rats were subdivided into untreated, simvastatin-treated, and Spirulina platensis-treated subgroups. Serum lipid profile, creatine kinase (CK), and malondialdehyde (MDA) levels were assessed. Histological, ultrastructural, and immunohistochemical analyses were conducted to assess muscle fiber integrity and expression of TGF-β1 and Bcl2. Results: Spirulina platensis significantly improved lipid parameters, reduced CK and MDA levels, preserved muscle histoarchitecture, and downregulated fibrotic (↓TGF-β1) and apoptotic (↑Bcl2) responses compared to the dyslipidemic and simvastatin-treated groups. Our results proved that Spirulina platensis ameliorates the effects of statin-associated myopathy while exerting lipid-lowering, cytoprotective, and antifibrotic effects. Conclusion: These molecular and ultrastructural benefits position Spirulina platensis as a promising, natural alternative to statins for managing dyslipidemia and preventing statin-induced myopathy. Future translational and clinical studies are warranted to further validate its efficacy and safety, supporting its broader application in metabolic and muscle-related disorders. Full article

The application of conductive polymers in wound dressings presents great potential for accelerated wound healing since their high electrical conductivity and biocompatibility facilitate the delivery of external electrical stimuli to cells and tissues, promoting cell differentiation and proliferation. Electrospinning is a very straightforward method for the preparation of polymeric wound dressings capable of mimicking the extracellular matrix of skin, promoting hemostasis, absorbing wound exudate, allowing atmospheric oxygen permeation and maintaining an appropriately moist environment. In this work, in situ chemically polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) was achieved through hyaluronic acid-doping. The synthesized PEDOT was used for the production of conductive and biodegradable chitosan (CS)/gelatin (GEL)/PEDOT electrospun meshes. Additionally, the randomly aligned meshes were crosslinked with a 1,4-butanediol diglycidyl ether and their physicochemical and mechanical properties were investigated. The results show that the incorporation of a conductive polymer led to an increase in conductivity of the solution, density and fiber diameter that influenced porosity, water uptake, and dissolvability and biodegradability of the meshes, while maintaining appropriate water vapor permeation values. Due to their intrinsic similarity to the extracellular matrix and cell-binding sequences, CS/GEL/PEDOT electrospun nanofibrous meshes show potential as conductive nanofibrous structures for electrostimulated wound dressings in skin tissue engineering applications. Full article

This numerical study introduces a surface plasmon resonance (SPR)-based biosensor utilizing a kagome lattice-inspired hollow core photonic crystal fiber (PCF) for the highly sensitive detection of various blood biomarkers and analytical components. The sensor is designed to detect key blood biomarkers such as water, glucose, plasma, and hemoglobin (Hb), as well as analytical targets including krypton, sylgard, ethanol, polyacrylamide (PA), and bovine serum albumin (BSA), by monitoring shifts in the resonance wavelength (RW). A dual-polarization approach is employed by analyzing both transverse magnetic (TM) and transverse electric (TE) modes. The proposed sensor demonstrates exceptional performance, achieving maximum wavelength sensitivities (Sw) of 18,900 nm RIU⁻¹ for TM pol. and 16,800 nm RIU⁻¹ for TE pol. Corresponding peak amplitude sensitivities (S_A) of 71,224 RIU⁻¹ for TM pol. and 58,112 RIU⁻¹ for TE pol. were also observed. The peak sensor resolution (S_R) for both modes is on the order of 10⁻⁶ RIU, underscoring its high precision. Owing to its enhanced sensitivity, compact design, and robust dual-polarization capability, the proposed biosensor holds strong promise for point-of-care diagnostics and real-time blood component analysis. Full article

This study evaluated the performance of ultra-fine bar refiner plates with a cutting edge length (CEL) of 97 km/s in enhancing the properties of Korean Old Corrugated Containers (KOCCs) compared to conventional plates with a CEL of 37 km/s. While unrefined KOCCs demonstrated compromised mechanical properties except for higher paper bulk, refining with the ultra-fine bar plate significantly improved tensile strength, tear strength, and water retention value (WRV). Although the conventional plate achieved higher stock throughput at lower specific energy, the ultra-fine bar plate proved more energy-efficient for achieving targeted fiber quality enhancements. The observed throughput plateau of the ultra-fine bar plate is attributed to its narrower groove design, which increases flow resistance. Overall, the ultra-fine bar plates offer a promising route for producing high-performance recycled paper by balancing refining energy inputs and fiber quality improvements. Full article

Background/Objectives: The melt-spinning process has seen limited application in the pharmaceutical industry. However, nano- and microfibrous structures show significant potential for novel drug delivery systems, due to their high specific surface area. To facilitate broader adoption in pharmaceutical technology, critical parameters influencing fiber quality and yield must be investigated. In this study, we aimed to develop an isomalt-based microfibrous carrier system for active pharmaceutical ingredients. Methods: The effects of different isomalt compositions—specifically, varying ratios of GPS (6-O-α-d-glucopyranosyl-d-sorbitol) and GPM (1-O-α-d-glucopyranosyl-d-mannitol)—as well as key process parameters, were systematically investigated to optimize fiber formation. The prepared fibers underwent different treatments. Morphological changes were monitored with a microscope, and microstructural changes were studied using a differential scanning calorimeter and X-ray diffractometer. The macroscopic behavior of the fibers was evaluated by image analysis under monitored conditions. Results: Statistical analysis was used to determine the optimal setting to produce isomalt-based fibers. We found that storage over ethanol vapor has a positive effect on the stability of the fibers. We successfully prepared ibuprofen sodium-containing fibers that remained stable after alcohol treatment and enabled drug release within 15 s. Conclusions: It was found that the applied GPS:GPM isomalt ratio significantly influenced fiber formation and that storage over ethanol positively influenced the processability and stability of the fibrous structure. An isomalt-based microfibrous system with advantageous physicochemical and structural properties was successfully developed as a potential drug carrier. The system is also resistant to the destructive effects of ambient humidity, enabling preparation of suitable dosage forms. Full article

This study aimed to valorize underutilized local ingredients by developing nutritionally enhanced pasta products enriched with sorghum and cork oak flours. The resulting pasta samples were characterized by their chemical composition, color attributes, functional properties, texture, microstructure, and antioxidant capacity. Semolina-based pasta showed higher protein content, while cork oak flour contributed significantly to lipid content, and sorghum flour was notably rich in fiber and minerals. Colorimetric analysis quantified visible differences in appearance, depending on the type of flour used. Functional assessment showed comparable water absorption indices across all samples; however, sorghum-enriched pasta exhibited significantly higher water solubility. Textural analysis indicated that sorghum reduced pasta adhesiveness and cohesiveness, whereas cork oak flour increased hardness, gumminess, and adhesiveness—likely due to its high fiber content, contributing to a stickier mouthfeel. Microstructural observations confirmed a denser and more compact matrix in pasta formulated with cork oak flour. Antioxidant analysis revealed that cork oak flour imparted the highest antioxidant potential, followed by sorghum and semolina. HPLC/ESI-TOF-MS profiling demonstrated a rich and diverse polyphenolic composition in the enriched samples. These formulations not only enhance the functional and nutritional profile of traditional pasta but also align with the increasing consumer demand for low-carbohydrate, fiber-rich foods. Full article

In recent years, agricultural biomass-filled materials have been increasingly explored as sustainable alternatives to fossil-based polymers and for the development of biocomposites. In this study, micronized hemp stalks, a byproduct of the cannabis industry, were loaded into 10–20% of polypropylene/polyethylene bicomponent fibers in a cost-effective original airlaying process. The production process was developed to achieve high hemp content (up to 80%), while maintaining suitable structural and mechanical properties. Experimental analyses confirmed that the hemp-based biocomposite exhibited promising thermal conductivity values (0.068 ± 0.002 W/mK) and effective sound-attenuation capabilities that are comparable to commonly used insulating materials, such as stone wool. Furthermore, X-ray diffraction and field emission scanning electron microscopy measurements analyzed the insulation features of the hemp-based biocomposite prepared with its morphological and structural properties, revealing its high internal porosity and polymeric crystallinity. These results highlight the potential of hemp biocomposites as sustainable, economically viable alternatives for thermal and acoustic insulation applications. Full article

Optical fiber composite insulators are essential for photoelectric current measurement, yet insulation failure at embedded optical fiber interfaces remains a major challenge to long-term stability. This study proposes a strategy to replace conventional silicone rubber with cycloaliphatic-like epoxy resin (CEP) as the shed-sheathing material. Three optical fibers with distinct outer coatings, ethylene-tetrafluoroethylene copolymer (ETFE), thermoplastic polyester elastomer (TPEE), and epoxy acrylate resin (EA), were evaluated for their interfacial compatibility with CEP. ETFE, with low surface energy and weak polarity, exhibited poor wettability with CEP, resulting in an interfacial tensile strength of 0 MPa, pronounced dye penetration, and rapid electrical tree propagation. Its average interfacial breakdown voltage was only 8 kV, and the interfacial leakage current reached 35 μA after hygrothermal aging. In contrast, TPEE exhibited high surface energy and strong polarity, enabling strong bonding with CEP, yielding an average interfacial tensile strength of approximately 46 MPa. Such a strong interface effectively suppressed electrical tree growth, increased the average interfacial breakdown voltage to 27 kV, and maintained the interfacial leakage current below 5 μA even after hygrothermal aging. EA exhibited moderate interfacial performance. Mechanism analysis revealed that polar ester and ether groups in TPEE enhanced interfacial electrostatic interactions, restricted the mobility of CEP molecular chain segments, and increased charge traps. These synergistic effects suppressed interfacial charge transport and improved insulation strength. This work offers valuable insight into structure–property relationships at fiber–resin interfaces and provides a useful reference for the design of composite insulation materials. Full article

Defatting methods are key to modulating the nutritional, functional, and bioactive characteristics of edible insect powders. This study evaluated the effects of mechanical pressing and ethanol-based solvent extraction on Hermetia illucens larvae powder. Solvent-defatted samples (DPSs) showed the highest protein content (54.96 g/100 g), with a 61% increase compared to full-fat powder (FP), and the lowest residual lipid content (3.18 g/100 g). In contrast, mechanical pressing (DPP) preserved higher antioxidant activity (68.30% DPPH inhibition), a 30% increase over FP. DPS also showed greater fiber content (13.90 g/100 g), improved water solubility, emulsification capacity, and reduced water activity (0.269), desirable traits for food formulations. DPP retained higher hygroscopicity and exhibited the highest antioxidant potential among the samples. These findings demonstrate that defatting method selection significantly impacts the techno-functional and nutritional quality of insect powders and should align with the desired end use, whether for protein enrichment, enhanced antioxidant activity, or development of sustainable food ingredients. This work supports the strategic use of Hermetia illucens as a functional, high-protein ingredient and reinforces its role in advancing circular and sustainable food systems. Full article

Banana fiber, as a naturally biodegradable material, exhibits excellent mechanical properties and considerable application potential. However, conventional rotary blade scraping extractors often cause significant fiber damage during extraction, thereby reducing fiber quality. To enhance fiber integrity and extraction efficiency, this study developed a pulsating rubbing-based banana fiber extractor. The device comprises a rubbing device with two grass-textured belts and a pulsating pressing device driven by a cam mechanism. Through the synergistic action of periodic pressing and rubbing, flexible fracture of banana stems and efficient fiber separation are achieved. The fiber extraction process was simulated using the RecurDyn rigid–flexible coupling analysis method to verify the dynamic behavior of stem slices during rubbing. Structural parameters were optimized based on the Box–Behnken experimental design, with 17 groups of tests conducted, each repeated three times and averaged. The results indicated that, when the spring outer diameter was 30 mm, the feeding interval of stem slices was 4 s, and the clamping angle between the stem slices and the rubbing belts was 90°, the fiber extraction rate reached 61.35%, the impurity rate was 9.01%, and the integrity rate was 96.22%. These findings verify the feasibility of the equipment structure and process parameters, achieve a favorable balance between extraction efficiency and fiber quality, and provide a novel technical pathway and equipment support for the high-value utilization of banana stem resources. Full article

The construction industry is a major source of environmental degradation as it is responsible for a significant share of global CO₂ emissions, especially from cement and aggregate consumption. This study fills the need for sustainable construction materials by developing and evaluating a low-carbon fiber-reinforced concrete (FRC) made of steel slag powder (SSP), processed recycled concrete aggregates (PRCAs), and waste steel rivet fibers (WSRFs) derived from industrial waste. The research seeks to reduce dependency on virgin materials while maintaining high values of mechanical performance and durability in structural applications. Sixteen concrete mixes were used in the experimental investigations with control, SSP, SSP+RCA, and RCA, reinforced with various fiber dosages (0%, 0.2%, 0.8%, 1.4%) by concrete volume. Workability, density, compressive strength, tensile strength, and water absorption were measured according to the appropriate standards. Compressive and tensile strength increased in all mixes and the 1.4% WSRF mix had the best performance. However, it was found that a fiber content of 0.8% was optimal, which balanced the improvement in strength, durability, and workability by sustainable reuse of recycled materials and demolition waste. It was found by failure mode analysis that the transition was from brittle to ductile behavior as the fiber content increased. The relationship between compressive, tensile strength, and fiber content was visualized as a 3D response surface in order to support these mechanical trends. It is concluded in this study that 15% SSP, 40% PRCA, and 0.8% WSRF are feasible, specific solutions to improve concrete performance and advance the circular economy. Full article