Search Results (320)

This study investigates the effect of chemical modification of xylite—a fraction derived from Polish lignite—using succinic anhydride (SA) on the morphology and mechanical performance of isotactic polypropylene (iPP) composites. Xylite was incorporated at loadings of 1, 10, and 25 wt% and in two particle size ranges (40–63 µm and 63–125 µm), with and without SA (0.5 and 2 wt%). The composites were characterized by wide-angle X-ray scattering (WAXS), Fourier-transform infrared spectroscopy (FTIR), and tensile testing to evaluate crystallinity (Xc), β-phase content (kβ), and mechanical properties. Unmodified xylite reduced crystallinity (Xc down to ~37%) and significantly decreased ductility, with elongation at break strongly negatively correlated with filler content (r ≈ −0.68), indicating poor dispersion and weak interfacial adhesion. In contrast, SA addition (0.5–2 wt%) partially restored crystallinity (up to ~48%) and increased stiffness (Young’s modulus up to 2120 MPa), while altering β-phase content. FTIR analysis indicated reduced intermolecular hydrogen bonding between xylite surface hydroxyl groups in the presence of SA, consistent with interfacial chemical interactions, likely via esterification. The β-phase content showed a moderate positive correlation with xylite loading (r = +0.43) and a negative correlation with elongation at break (r = −0.46), suggesting that excessive β-phase formation may reduce toughness. Larger particles (63–125 µm) provided slightly improved elongation at break and stiffness. Overall, SA acts as both a compatibilizer and a morphology-directing agent, enabling precise control of the stiffness–ductility balance and crystalline structure in iPP/xylite composites. These results establish chemically modified lignite-derived fillers as a viable strategy for engineering cost-efficient polyolefin materials with tunable structure–property relationships, offering strong potential for scalable industrial implementation. Full article

Sapphire, with excellent optical properties and high hardness, has become a key hard and brittle material component in extreme environments like aviation equipment and infrared detection systems. Its processing quality directly determines the performance of various equipment systems. To address processing defects, technologies such as multi-wire cutting, magnetorheological polishing, chemical mechanical polishing, femtosecond laser processing, and ion beam etching have been developed and studied to improve the surface quality of sapphire components. This paper focuses on key technologies, including sapphire’s nano-scale surface morphology control, intrinsic nano-surface atomic-level defect control, and combined process systems for precision and shape control. These technologies lay the foundation for sapphire components’ process chain manufacturing to achieve high-precision shape and surface quality control. Full article

The ultra-precision machining of micro-optics from low glass transition temperature (T_g) hydrophobic polymers is frequently compromised by thermal instability and kinematic constraints imposed by on-axis turning. To address these challenges, this study presents a novel clamping–cooling system engineered for the off-axis diamond turning of low-T_g polymers. The design integrates vacuum clamping for workpiece stabilization with an embedded microchannel network for efficient thermal management. Strategic material selection effectively balances thermal insulation with mechanical stability. Performance evaluations demonstrated robust thermal regulation: lens blank surface temperatures stabilized at 6 °C during stationary testing, and the system was able to drop below 0 °C under maximum cooling targets. This strict thermal control enabled achieving nanometer surface roughness. Ultimately, this modular system facilitates the scalable, simultaneous production of high-quality, polishing-free intraocular lenses (IOLs), advancing manufacturing capabilities for complex precision optics. Full article

Surface strain measurements on carbon fiber-reinforced polymer (CFRP) structures using bonded strain gauges are often systematically underestimated due to strain transfer effects associated with the surface resin-rich layer. To investigate this issue, comparative bending experiments were performed on steel and CFRP beams, where the steel beam served as a reference structure with negligible strain transfer loss under equal-curvature conditions. An equal-curvature bending framework was established to ensure identical bending curvature at the strain measurement location for both materials, thereby eliminating the influence of material stiffness on global deformation. In parallel, controlled surface polishing was employed to precisely regulate the thickness of the resin-rich layer on CFRP specimens, enabling systematic evaluation of its influence on strain transfer behavior. Experimental results under equal-curvature conditions reveal a stable strain underestimation in CFRP surface measurements, with an average strain transfer coefficient of approximately 0.968. Furthermore, reducing the resin-rich layer thickness leads to a consistent increase in measured strain. Based on these observations, a practical strain correction model was established to improve the reliability and engineering applicability of surface strain measurements in CFRP structures. Full article

Background: Robotic-assisted thoracic surgery is increasingly recognized as an advanced minimally invasive technique for treating non-small cell lung cancer, offering technical advantages such as enhanced precision and visualization. Although numerous studies have been published worldwide, there are no comparable data from Poland. Therefore, evidence on the perioperative safety and oncologic adequacy of robotic-assisted lobectomy during early phase of program implementation within the Polish healthcare system remains limited. Methods: This retrospective, single-institution observational study included 81 consecutive patients who underwent robotic-assisted lobectomy for primary NSCLC between January 2022 and December 2024. All procedures were carried out using the da Vinci Xi system with a standardized four-arm portal approach. Clinical, perioperative, and pathologic parameters were prospectively collected and analyzed descriptively. Postoperative complications were classified according to Clavien-Dindo. Results: The median patient age was 70 years (IQR: 65–74), 52% were male, and 67% had a history of smoking. Adenocarcinoma was the predominant histologic subtype (51%). The median operative time was 176 min (IQR: 149–220). There were no conversions to thoracotomy and no 30-day mortalities. Postoperative complications occurred in 24% of cases, with prolonged air leak being most common (17%). The median hospital stay was 8 days (IQR: 6–10). R0 resection was achieved in 96% of patients, with a median of 14 lymph nodes dissected across 5 nodal stations. Conclusions: Robotic-assisted lobectomy performed during the early implementation phase of a national program demonstrated low morbidity, high rates of complete (R0) resection, and adequate lymph node yields consistent with international benchmarks. These results support the feasibility of robotic lobectomy within the Polish healthcare setting; however, the single-surgeon, single-center design limits generalizability. Further multicenter prospective studies are needed to confirm reproducibility, assess learning curves, and evaluate long-term oncologic outcomes. Full article

Modern agriculture must combine profitability with environmental protection and food safety by using advanced knowledge and continuously introducing new technologies. The study aimed to evaluate the diversification of precision farming in Poland and identify limitations to its development. The study used literature reviews and two secondary data sources: the Local Database of the Central Statistical Office (GUS) regarding the share of farms using precision farming solutions by voivodeship and the nationwide precision farming survey conducted by the Polish Space Industry Foundation. The survey included 432 agricultural producers from across Poland. Data analysis utilized descriptive statistics, comparative analysis, cluster analysis, and a chi-squared (χ²) test. Existing research shows that advanced precision farming technologies in Poland have been implemented only on a limited number of farms. This is due to limited knowledge among agricultural producers, the small scale of production on most farms, and high investment costs. These technologies include equipping farms with sprayers for strip application of plant protection products during sowing or planting, precision irrigation or weed control, variable-dose fertilizers or plant protection products, and soil sampling for analysis. The use of precision farming technologies varies regionally. They are primarily used on large farms located in western and northern Poland. The study’s results may be helpful to decision-makers in agricultural policy and to agricultural producers. Full article

As a key low-expansion material for high-end equipment such as aerospace and precision instruments, the surface quality of Invar alloy directly determines the operational performance of devices. To fill the research gap in the multi-parameter synergy and mechanism of Invar alloy laser polishing, this study performs polishing experiments on Invar alloy using a burst-mode femtosecond laser, with a repetition rate of 1 MHz and four sub-pulses per burst. The results indicate that energy density plays a dominant role in the polishing effect: with the increase in energy density, the surface roughness first decreases and then increases. A stable molten pool is formed under medium energy density (0.47–0.64 J/cm²), and under the optimal parameter conditions, the surface roughness is reduced to 394 ± 50 nm, representing a 52% reduction compared to the original surface (821 nm). Scanning speed and scanning pitch affect the polishing effect by synergistically regulating energy input: increasing scanning speed under high energy density can inhibit the rise in roughness, while a small scanning pitch can lower the threshold of optimal energy density. Amplitude spectrum analysis reveals that the medium-scale surface undulations are significantly improved after polishing. A four-layer Fully Connected Neural Network (FCNN) model is established to achieve high-precision prediction of polishing effects with a coefficient of determination R² = 0.92, which enables rapid prediction of unknown polishing parameter combinations and provides a new solution path for the optimization of polishing effects. This study clarifies the interaction mechanism between a burst-mode laser and Invar alloy, proposes an efficient ultra-precision polishing method for Invar alloy, and lays a theoretical foundation for its application in the field of high-end manufacturing. Full article

This study proposes a new fabrication process for terahertz Fresnel zone plates on high-resistivity silicon substrates. It involves ion implantation surface modification, ultra-precision diamond turning, and magnetron sputtering, followed by polishing. Ductile-regime cutting is used to form smooth microgrooves, which are selectively metallized to create alternating opaque and transparent zones for terahertz waves. Finite-element simulations are performed to design the zone structure and to evaluate the effect of process-induced radius errors. A 3 μm amorphous layer is formed via ion implantation, which significantly enhances the ductile-to-brittle transition depth of silicon from 55 nm to about 535 nm while causing only minor changes in terahertz transmittance. The results demonstrate that the proposed method can produce high-quality Fresnel zone plates on silicon and offers a practical route to compact diffractive terahertz components. Full article

GH3536 superalloy is widely used in the high-temperature components of aerospace applications for its excellent high-temperature strength and corrosion resistance. However, under such a harsh environment, surface defects can make the superalloy prone to corrosion and fatigue fractures. Therefore, it is important to eliminate surface defects through polishing. However, the existing polishing methods usually suffer from some issues such as surface integrity damage, low efficiency, and poor environmental sustainability. More importantly, these methods fail to account for the requirement of surface roughness below 0.05 μm in some high-precision aerospace components. Herein, the plasma electrolytic polishing (PEP) of GH3536 superalloy is systematically investigated and optimized through single-factor experiments and response surface methodology (RSM). A minimum surface roughness Ra of 0.044 μm with a mirror-like surface was achieved at a voltage of 303.8 V, electrolyte temperature of 66.2 °C, polishing time of 5 min, and submersion depth of 7.5 cm. At the same optimized condition, the material removal rate was 59.12 mg·min⁻¹. After polishing, the surface composition of GH3536 superalloy varied negligibly, while its corrosion resistance improved markedly, with a 53.72% increase in polarization resistance and a 43.46% decrease in corrosion current density. Meanwhile, the microhardness slightly decreased due to the removal of the work-hardened layer and the compressive residual stress exhibited a more uniform distribution across the surface, contributing to improved near-surface mechanical stability. This study establishes an optimized PEP parameter for improving the surface quality of GH3536 superalloy, offering a practical method for the precision finishing of aerospace-grade superalloy components. Full article

Background: In traditional karate, performance effectiveness is determined, among other factors, by the speed of stimulus processing and the precision of the motor response. Body composition may indirectly modulate these abilities; however, data on karate athletes are limited. Methods: The study included 27 men—active members of the Polish national team in traditional karate (18–30 years; training experience ≥ 5 years; black belt). Body composition was assessed using segmental bioelectrical impedance analysis (InBody 770), and psychomotor abilities were measured with the TEST2DRIVE system: SIRT (simple reaction), CHORT (choice reaction), HECTOR (simple reaction), and SPANT (spatial anticipation). Results: The psychomotor profile showed the longest reaction times in CHORT and the shortest in SIRT. Associations with body composition were selective: in SIRT, the median simple reaction time demonstrated a moderate positive relationship with lean-mass-related parameters, with no associations for motor time. No significant correlations with body composition were found in CHORT or HECTOR. In SPANT, significant associations concerned motor time only, which was positively related to selected indices of adiposity and fat distribution, whereas choice reaction time and accuracy were independent of body composition. Conclusion: In traditional karate athletes, body composition is not an unambiguous predictor of psychomotor performance, and its relevance depends on task characteristics. The findings suggest that potential effects of somatic parameters are expressed mainly in selected execution components; therefore, assessments of competitive readiness should combine body composition monitoring with tests that differentiate the reaction phase from the motor phase. Full article

As a critical pretreatment process for chemical and mechanical polishing (CMP), the lapping roughness of gallium nitride (GaN) crystals directly influences the outcome of subsequent polishing and the reliability of final devices. This study systematically investigates the key factors affecting the lapping performance of GaN single crystals, focusing on abrasive type, particle size, and spindle speed, and elucidates their mechanisms in regulating material removal rate (MRR) and surface roughness. Using a micro-thickness gauge and controlled variable method, the material removal depth of the (0001) plane of GaN was accurately measured. The results show that the MRR increases with the increase in abrasive particle size within a certain range, albeit at the cost of increased surface roughness. Meanwhile, the spindle speed and MRR exhibit a positive correlation under specific conditions. Considering these lapping parameters, a balance between high MRR and controlled roughness can be achieved, providing a technical foundation for efficient and precise lapping of GaN crystals and facilitating the fabrication of GaN-based devices. Full article

As precision polishing and post-processing advance, surface-layer absorptive defects in fused silica optics increasingly show random distribution, low quantity, and ultra-low concentration—making efficient, non-destructive inspection of large-aperture components challenging. In this study, fused silica samples made by conventional ring polishing and acid cleaning were analyzed using photothermal weak absorption (PTWA), micro-X-ray fluorescence (μ-XRF), micro-X-ray diffraction (μ-XRD), and ultraviolet fluorescence microscopy spectroscopy. Results show that process-related contaminants emit strong spontaneous fluorescence between 500 and 620 nm under 375 nm ultraviolet (UV) excitation. Using this optical signature, a high-throughput detection system was developed that combines rapid fluorescence imaging for screening with PTWA for verification. Full-area scanning of a 100 mm × 100 mm sample successfully identified absorptive defects with significantly improved efficiency over conventional methods. This work provides a practical quality control solution for large-aperture fused silica optics and supports process optimization to reduce laser damage risks in high-performance systems. Full article

In this work, a D-shaped Photonic Crystal Fiber (PCF) sensor with a detection range of 1.30–1.35 is proposed, including Gold (Au), Titanium Dioxide (TiO₂), graphene, and a functionalized sensing region. Instead of filling or coating inside the PCF’s air holes, the Gold (Au) layer is applied to the polished surface. The effects of the larger air holes’ diameter and the thickness of the Au layer are examined. To achieve effective RI sensing, the proposed design leverages the strong coupling between the core mode and the Surface Plasmon (SP) excitation mode. Modal dispersion, confinement loss, and electric field distributions are analyzed for analyte RI values ranging from 1.30 to 1.35 using the Finite Element Method (FEM). The sensor demonstrates improved plasmonic excitation with a maximum Wavelength Sensitivity (WS) of 3000 nm/RIU (Au = 45 nm), strong confinement loss of more than 788.39 dB/cm (at Au = 40 nm), and a highest Figure of Merit (FoM) of 62.5/RIU (at Au = 40 nm with RI = 1.32). The TiO₂ layer enhances mode coupling and resonance sharpness, while the optimized Au thickness boosts sensitivity and spectral resolution. Additionally, the blood components reach the WS of 5000 nm/RIU for plasma and 3000 nm/RIU for Krypton. Because of its high tunability and repeatable performance, the PCF–SPR biosensor is a promising choice for precise biochemical and biomedical sensing applications. Full article

The thickness of silicon carbide (SiC) wafers is a crucial parameter that significantly affects the performance of devices, and its high-precision online measurement during chemical mechanical polishing (CMP) faces challenges from complex process-induced errors. To address this issue, this study develops a non-contact online thickness measurement system based on oblique-incidence laser triangulation and proposes a hierarchical hybrid error compensation method. Deterministic systematic errors caused by optical interference from polishing slurry are first compensated by combining an optical propagation physical model with experimental calibration. Subsequently, a Long Short-Term Memory (LSTM) network model is introduced to compensate for nonlinear, time-series-related dynamic random errors, primarily induced by temperature drift and associated thermal effects. Experimental results indicate that, after applying the proposed compensation method, the root mean square error (RMSE) of the online thickness measurement is 0.47471 $\mathsf{\mu }\mathrm{m}$, and the mean absolute percentage error (MAPE) is 0.1102%. The deviation from reference thickness values is maintained within ±1 $\mathsf{\mu }\mathrm{m}$. The proposed method provides an effective solution for high-precision online thickness measurement and error compensation in the SiC CMP process. Full article

Objectives: This systematic review evaluated enamel surface alterations and residual composite following the removal of clear aligner attachments, with particular emphasis on the influence of removal techniques, instrument selection, operator experience, and the use of magnification on enamel preservation and cleaning efficiency. Methods: A comprehensive electronic search was performed in PubMed, Scopus, Embase, Web of Science, and Scielo up to October 2025. In vitro, ex vivo, and clinical studies assessing enamel loss, residual composite, surface roughness, or removal time after clear aligner attachment removal were included. Study selection, data extraction, and methodological assessment followed the PRISMA 2020 guidelines and Cochrane Handbook recommendations. Risk of bias was evaluated using a modified Joanna Briggs Institute checklist for laboratory-based studies. Due to substantial methodological heterogeneity, a narrative synthesis was conducted. Results: Of 656 identified records, three in vitro/ex vivo studies were assessed for eligibility. Reported enamel loss ranged from approximately 15 µm to more than 50 µm, depending on the removal protocol and visualization conditions. Residual composite covered approximately 20–40% of the treated enamel surface. Multi-step protocols combining tungsten carbide burs with silicone polishers under magnification demonstrated the most favorable balance between composite removal efficiency and enamel preservation. Fiberglass burs were associated with smoother enamel surfaces but increased enamel loss, whereas one-step polishing systems (OneGloss, Enhance, SM104) resulted in reduced surface roughness and shorter procedural time. The use of magnification loupes (≥2.5×) consistently improved removal precision and reduced residual composite. Meta-analysis was not feasible due to heterogeneity in outcome measures and testing methodologies. Overall risk of bias was deemed acceptable. Conclusions: Based on the limited number of available in vitro/ex vivo studies, removal of clear aligner attachments appears to be associated with measurable enamel loss and residual composite, largely influenced by the instruments and visualization aids used. Sequential carbide–silicone polishing protocols performed under magnification appear promising based on limited in vitro/ex vivo evidence, demonstrating a favorable balance between composite removal and enamel preservation under controlled laboratory conditions. However, given the scarcity of evidence and absence of clinical trials, these findings cannot be directly extrapolated to routine clinical practice. Further well-designed studies are required before definitive clinical recommendations can be established. Full article