Search Results (259)

Non-destructive and destructive test methods are applied to wood to characterize this heterogeneous natural material. There have been multiple studies to characterize and investigate the change after the treatment (impregnation, thermal modification, etc.). In terms of thermal modification, there have been few studies on thermo–vacuum treatment, which is performed in a continuous vacuum atmosphere. With this method, the objective was to attempt to reduce the strength decrease after the thermal treatment. The aim of this study was to estimate the flexural properties of thermo–vacuum-treated Scots pine wood with destructive and acoustic-based non-destructive test methods. Wood was treated at 180 °C and 360 mm Hg. Both treated and untreated samples were cut into small specimens to ensure they were free of defects and were tested with acoustic-based non-destructive (longitudinal vibration and stress wave) and static bending test methods. The results show a decrease in equilibrium moisture content, demonstrating the efficiency of the treatment. When the results were compared with destructive test results, higher correlations (R² > 0.858) were found when estimating the modulus of elasticity (MOE) for both the untreated and treated wood, while lower correlations (R² < 0.440) were found for the modulus of rupture (MOR). When an additional equation was developed, stronger correlations (R² > 0.8986) were obtained between the non-destructive and destructive test results. Full article

Hyperspectral imaging (HSI) combined with chemometrics has emerged as a rapid and non-destructive technique for fruit quality evaluation, enabling efficient monitoring of biochemical changes during postharvest storage. Among quality indicators, antioxidant activity is closely associated with nutritional value and physiological stability. This study aimed to develop an HSI-based approach for assessing the antioxidant capacity of strawberries subjected to different pre-cooling treatments during storage. Strawberries were treated with five pre-cooling methods and stored for up to 41 days. Antioxidant activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Hyperspectral data were collected and preprocessed using multiplicative scatter correction (MSC), followed by partial least squares regression (PLSR) to construct predictive models. Among the treatments, immersion vacuum cooling combined with one-cycle pulsing (IVCWP1) exhibited significantly higher DPPH scavenging activity (61.17 ± 12.31%) than immersion vacuum cooling with water (IVCW, 52.89 ± 18.30%) (p < 0.05). The PLSR model developed using MSC-corrected average reflectance spectra showed superior predictive performance and a higher coefficient of determination (R²) than models based on raw spectra. The results demonstrate that HSI coupled with chemometrics is an effective and practical tool for non-destructive evaluation of antioxidant activity and comparison of pre-cooling strategies in strawberries. Full article

Thermochemical heat storage technology serves as an effective approach for efficient recovery and cross-seasonal storage of low-grade waste heat. However, traditional packed-bed heat exchange methods in industrial applications are prone to material contamination and performance degradation due to impurities in waste heat gases. To address this, this study proposes and constructs a thermochemical heat storage system based on moving-bed indirect heat exchange, using magnesium sulfate heptahydrate (MgSO₄·7H₂O) as the heat storage medium. The system investigates its desorption and heat storage characteristics within the moving bed. A small-scale moving-bed experimental platform was established, incorporating a vacuum-assisted system to promptly remove water vapor generated during desorption. The experimental system examines the effects of different operating parameters (e.g., inlet water temperature and flow rate) on particle temperature fields, desorption rates, and overall heat transfer performance. Results demonstrate that MgSO₄·7H₂O exhibits excellent heat storage stability and reaction controllability in the medium-low temperature range (60–95 °C). Increasing inlet water temperature and flow rate enhances desorption processes, but high temperatures also lead to increased temperature gradients, reducing waste heat recovery rates. Practical applications require optimizing the balance between heat transfer enhancement and desorption time. Compared to conventional heat storage particles, the moving-bed system using magnesium sulfate heptahydrate achieves approximately 30% higher overall heat transfer coefficient. Compared to traditional packed beds, the moving-bed heat exchange method demonstrates superior heat transfer uniformity and storage efficiency. This study validates the feasibility of the “moving-bed + thermochemical heat storage + vacuum desorption” technology under non-clean heat source conditions, providing experimental evidence and technical references for efficient industrial waste heat recovery and high-density storage. Full article

Background and Objectives: Because of its consistently high stone-free rates (SFRs), percutaneous nephrolithotomy (PCNL) continues to be the first-line treatment for renal stones larger than 20 mm. Standard 24 to 30 Fr access tracts, however, are linked to access-related morbidity, such as bleeding, pain, and extended hospital stays. These restrictions have led to progressive tract miniaturization and the development of mini-PCNL, ultra-mini PCNL, and micro-PCN techniques. Materials and Methods: We performed a narrative review of studies published through January 2026 using PubMed and Google Scholar. Search terms included percutaneous nephrolithotomy, mini-PCNL, ultra-mini PCNL, micro-PCNL, and vacuum-assisted PCNL. Original studies, systematic reviews, and meta-analyses reporting clinical outcomes, complications, and advancements were selected, whereas conference abstracts, non-English papers, and articles without accessible full text were excluded. Results: Across randomized trials, miniaturized PCNL generally preserves efficacy when patients are selected appropriately. Across randomized trials and meta-analyses, miniaturized PCNL achieved stone-free rates comparable to standard PCNL (typically ~80–90% for stones ≤20 mm and similar rates in selected stones >2 cm), while demonstrating lower hemoglobin decrease (mean difference approximately −0.6 to −1.0 g/dL), reduced transfusion rates, and shorter hospital stays, at the cost of longer operative time (mean difference ~8–12 min). On the other hand, operative time may increase, and smaller working channels can make visualization and fragment evacuation more demanding as stone burden rises. Raised intrarenal pressure is a recurring safety issue because it may increase infectious risk unless drainage is actively managed. Recent innovations aim to address these limitations, including vacuum-assisted access sheaths, pressure-controlled irrigation, improved laser and lithotripsy platforms, image-fusion guidance, navigation systems, and robotic assistance. Conclusions: PCNL now spans a spectrum of tract sizes rather than a single standard approach. When chosen appropriately and performed with attention to pressure control and fragment evacuation, miniaturized PCNL can reduce morbidity without sacrificing stone clearance. Future advancements in percutaneous stone surgery are more likely to rely on integrated technological solutions that improve accuracy, safety, and repeatability than on additional tract size reduction. Full article

The further development of scalable fabrication for perovskite solar cells has been considerably constrained by strong process variability and the lack of a reliable real-time predictive mechanism during the thin-film formation process. Existing machine learning-based methods are incapable of capturing the inherent multi-stage kinetic characteristics and uncertainties of the perovskite crystallization process, as they rely on deterministic point prediction models and flatten time-series signals into static features, which necessitates more advanced modeling strategies. To address these challenges, an in situ process monitoring and predictive modeling framework based on a lightweight probabilistic Transformer is proposed for the scalable preparation of perovskite thin films. The strategically designed inputs, consisting of time-resolved photoluminescence (PL) and diffuse reflectance imaging signals acquired during the vacuum quenching process, enable the model to directly learn the conditional probability distribution of the final device performance metrics. Rather than producing a single predicted value, this method enables the explicit quantification of prediction uncertainty, providing statistical support for uncertainty-aware process assessment. Leveraging its advantages over feed-forward neural networks and traditional tree-based machine learning methods, the proposed Transformer architecture effectively captures the staged and non-stationary kinetic features of thin-film formation. Consequently, it exhibits higher robustness and superior uncertainty calibration capability during the early-stage prediction phase. The results demonstrate that the probabilistic Transformer-based modeling paradigm provides a viable pathway toward uncertainty-aware, data-driven process evaluation in perovskite manufacturing. This framework extends its application beyond perovskite photovoltaic device fabrication, providing a generalizable modeling strategy for real-time predictive assessment in the preparation of other complex materials governed by irreversible stochastic dynamics. Full article

(1) Background: Indwelling pleural catheters (IPCs) with vacuum-based drainage can cause pain, especially in patients with a non-expandable lung (NEL). This evaluation assessed whether the Passio™ digital drainage system offers a viable alternative for patients experiencing pain during IPC drainage. (2) Methods: All IPC patients between November 2023 and April 2024 completed questionnaires assessing pain severity on a 10-point visual analogue scale (VAS) at four points during drainage. Patients reporting drainage-related pain at the 2-week post-IPC appointment had their existing valve replaced with a Passio™ valve (n = 5). (3) Results: Twenty-seven patients (59% male) were included in this analysis. The mean VAS scores for pain with a standard vacuum bottle were not statistically different at mid-drainage and the end of drainage compared with pre-drainage. Patients who experienced pain with the vacuum bottle (n = 5) had higher mean VAS scores at mid-drainage (51.68 mm ± 16.29; p = 0.13), end of drainage (46.68 mm ± 19.45; p = 0.19), and 10 min post-drainage (61.38 mm ± 9.81; p = 0.06) compared with pre-drainage (9.16 mm ± 4.01). Post-Passio™ valve replacement (n = 5), patients had a lower VAS pain score mid-drainage (20.15 mm ± 9.34; p = 0.25), end of drainage (27.28 mm ± 12.69; p = 0.84), and 10 min post-drainage (14.81 mm ± 3.33; p = 0.0079) when compared with vacuum bottle drainage. There were no complications with the Passio™ drainage system. (4) Conclusions: Controlled pleural drainage using a digital drainage device such as Passio™ may have a role in IPC patients who experience pain with vacuum bottle drainage, especially in those with an NEL. Full article

A vacuum-arc pulsed plasma accelerator (APPA) operating at a discharge current of 750 A and a pulse duration of 110 μs with a repetition rate of 5 Hz was employed to deposit thin films and coatings under low- and medium-vacuum conditions. The aim of this study was to obtain metal coatings suitable for potential applications in the energy and chemical industries. SEM, AFM, and XRD techniques were used to investigate the structure and morphology of coatings formed on metallic and insulating substrates under the following conditions: residual pressure of 10⁻²–10⁻⁴ mbar and deposition times of 10–30 min. Under medium-vacuum conditions, thin and non-uniform metallic films with thicknesses ranging from 0.4 to 1.9 μm were deposited on metal substrates. The morphology of thick films deposited under low-vacuum conditions consisted of spherical metal particles of various sizes (0.1–1 μm), containing up to 30% carbon and 28% oxygen. On silicon substrates, spherical microparticles up to 4 μm in diameter with thin shells approximately 0.3 μm thick were formed. One possible mechanism for microsphere formation—the desorption of residual gases by the coating material—is discussed. The potential of the APPA method for producing metal shells, relevant to powder manufacturing due to the high energy density of the process and the intrinsic purity of vacuum technologies, is also considered. Porous coatings obtained using the APPA technique may be applicable in the fabrication of energy-related materials, such as battery anodes. Full article

The rapid progress of perovskite solar cells (PSCs) has established them as a groundbreaking technology for sustainable energy. However, the sustainability of their lifecycle is still hindered by challenges related to material toxicity and end-of-life management. This review comprehensively assesses emerging recycling technologies, with a particular focus on their effectiveness in recovering perovskite compounds, transparent conductive oxides, and metallic contacts. Mechanical separation, solvent-based dissolution, thermal decomposition, and hybrid methods are compared in terms of recovery rates, purity levels, energy consumption, and scalability. Current challenges, such as the generation of secondary waste, the instability of recovered perovskites, and economic barriers, are critically analyzed alongside emerging solutions, including the use of non-toxic solvents, vacuum-assisted recovery, and the integration of closed-loop manufacturing. By evaluating lifecycle impacts and cost–benefit trade-offs, this work outlines pathways for transforming PSC waste into high-value secondary resources, thereby promoting both environmental sustainability and industrial competitiveness. Full article

Background: Post-harvest losses in bananas, particularly due to diseases such as anthracnose and stem-end rot, significantly limit their storage life and marketability. Developing effective and non-toxic treatments to prolong the shelf life of fruits while maintaining quality is crucial inenabling long-distance transport and facilitating exports. Methods: The most popular and commercial banana variety, ‘Grand Naine’, was treated with a proprietary secondary metabolite-based formulation (this refers to a solution containing natural compounds produced by living organisms, which are not directly involved in growth but can influence various biological processes, such as antimicrobial activity) and stored under cold conditions at 13 °C, using vacuum packaging (a method where air is removed from the packaging to reduce spoilage and prolong freshness). Untreated fruits were considered as controls, meaning that they were not subjected to the treatment and served as a baseline for comparison. Shelf life-related parameters such as ethylene production (a plant hormone responsible for triggering fruit ripening), ACC oxidase activity (an enzyme central to ethylene synthesis), respiration rate (the rate at which fruit consumes oxygen and produces carbon dioxide), firmness, total soluble solids (TSS; measures the sugar content in fruit), acidity, and metabolic composition were assessed, including indices of susceptibility to disease. These measurements were taken at regular intervals for both treated and control fruits. Results: Secondary metabolite-treated bananas maintained quality for 45 days, staying free from anthracnose and stem-end rot. Control fruits showed over-ripening and an 11.6% percent disease index (PDI). Treated fruits had lower ethylene production (7.80 μg/kg/s vs. 10.03 μg/kg/s in controls), reduced ACC oxidase activity, and a slower respiration rate, delaying ripening. They also had greater firmness (1.45 kg/cm²), optimal TSS (13.5 °Brix), balanced acidity (0.58%), and increased flavonoid and antioxidant levels compared to controls. Conclusions: Secondary metabolite-based treatment, combined with cold storage and vacuum packaging, extended banana shelf life to 45 days, minimized disease, and preserved fruit quality. This approach substantially reduced post-harvest losses, demonstrating export potential through extended storage. Full article

The Gannan navel orange (GNO) industry is large but constrained by limited deep-processing. This study employed vacuum freeze-drying (FD) and hot-air drying (HD) methods to prepare dried GNO slices, comparing their physical properties, volatile/non-volatile compounds, antioxidant activity, and sensory quality. Compared with the HD sample (ΔE= 10.11), the color changes were more pronounced in the FD sample (ΔE= 34.39), which appeared whiter and brighter. The FD method preserved more vitamin C (9.09% loss) than the HD method (27.28% loss). In contrast, HD samples contained significantly higher levels of total flavonoids, total phenols, hesperidin, narirutin and didymin, with respective increment percentages of 13.81%, 19.27%, 17.03%, 27.56% and 33.33% compared to FD samples. Volatile analysis revealed that drying treatments led to a decrease in terpene content compared with fresh slices (fresh 48.84% vs. FD 47.81% vs. HD 47.42%), while ester content increased (fresh 13.87% vs. FD 14.59% vs. HD 14.45%). Both methods reduced key monoterpenes (e.g., β-terpineol, terpinolene, 3-carene, α-terpineol, β-thujene and α-terpinene), possibly converting them into compounds such as p-mentha-1(7),8-diene-ol and thymol. Notably, HD samples contained much higher levels of harmful compounds 5-hydroxymethylfurfural and furfural. FD samples exhibited superior antioxidant activity and were preferred in sensory evaluation for appearance, aroma, texture, and taste. The findings indicate that FD offers advantages in terms of morphological retention, vitamin C preservation, antioxidant activity, safety and sensory perception, underscoring the market potential of FD navel orange slices as a high-value, healthy food product. Full article

The Wigner representation for quantum mechanics of particles is generalized to Bose fields. The standard Hilbert space quantization becomes, via the Weyl transform, a quantization method that consists of adding a Gaussian zeropoint field distribution to the vacuum. I comment on the possible advantages of the method in order to study quantum fields in curved spaces. I study a unified formulation of non-relativistic quantum electrodynamics in the Weyl–Wigner formalism, in terms of (classical-like) c-numbers. Full article

An optical levitation system in a vacuum is an efficient system to investigate the dynamics of isolated micro- and nanoparticles. However, the motion and stability of the trapped particles in this system can be affected by the internal temperature, which remains a challenge to measure. Conventional methods are constrained by material specificity or lack the capability for direct temperature measurement. Here, we demonstrate the application of Raman thermometry for non-contact temperature detection of an optically levitated fused silica sphere in vacuum. In addition, the experimental results reveal a linear increase in particle temperature with laser power, consistent with photothermal theory. The integration of Raman thermometry with the optical levitation system enables high-precision thermal sensing at the microscale, offering significant potential for applications in precision metrology and fundamental physics. Full article

We introduce a fully solution-processed interlayer strategy for n–p CdS/PbS thin film solar cells that combines a sol–gel ZnO compact coating with an electrospun ZnO nanofiber network. The synthesis and characterization of ZnO, CdS, and PbS thin films, complemented by electrospun ZnO nanofibers, are aimed at low-cost photovoltaic applications. Sol–gel ZnO films exhibited a hexagonal wurtzite structure with a bandgap (Eg) of approximately 3.28 eV, functioning effectively as electron transport and hole-blocking layers. CdS films prepared by chemical bath deposition (CBD) showed mixed cubic and hexagonal phases with an Eg of about 2.44 eV. PbS films deposited at low temperature displayed a cubic galena structure with a bandgap of approximately 0.40 eV. Scanning Electron Microscopy revealed uniform ZnO and CdS surface coatings and a conformal 1D ZnO network with nanofibers measuring about 50 nm in diameter (ranging from 49.9 to 53.4 nm), which enhances interfacial contact coverage. PbS films exhibited dense grains ranging from 50 to 150 nm, and EDS confirmed the expected stoichiometries. Electrical characterization indicated low carrier densities and high resistivities consistent with low-temperature processing, while mobilities remained within reported ranges. The incorporation of ZnO layers and nanofibers significantly improved device performance, particularly at the CdS/PbS heterojunction. The device achieved a V_oc of 0.26 V, an J_sc of 3.242 mA/cm², and an efficiency of 0.187%. These improvements are attributed to enhanced electron transport selectivity and reduced interfacial recombination provided by the percolated 1D ZnO network, along with effective hole blocking by the compact film and increased surface area. Fill-factor limitations are linked to series resistance losses, suggesting potential improvements through fiber densification, sintering, and control of the compact layer thickness. This work is a proof-of-concept of a fully solution-processed and low-temperature CdS/PbS architecture. Efficiencies remain modest due to low carrier concentrations typical of low-temperature CBD films and the deliberate omission of high-temperature annealing/ligand exchange. Overall, this non-vacuum, low-temperature coating method establishes electrospun ZnO as a tunable functional interlayer for CdS/PbS devices and offers a practical pathway to elevate power output in scalable productions. These findings highlight the potential of nanostructured intermediate layers to optimize charge separation and transport in low-cost PbS/CdS/ZnO solar cell architectures. Full article

Spices play a crucial role in shaping the characteristic flavor of marinated meat products. This study systematically compared the effects of physical crushing, vacuum nano-collision, and steam explosion on the physical and flavor characteristics of star anise and cinnamon. The vacuum nano-collision treatment effectively reduced particle size to below 15 nm, promoting faster flavor release and improving both moisture retention and solubility. Hydrocarbons, alcohols, and aldehydes were identified as the dominant volatile compounds. Among the non-volatile components, crushed cinnamon contained the highest shikimic acid concentration (1510.1 ± 25.45 μg/kg), while star anise treated with vacuum nano-collision reached the highest level of shikimic acid (893.10 ± 23.99 μg/kg). However, the main active components of these two spices did not show significant differences between the two treatment methods. Steam explosion treatment resulted in the lowest levels of both volatile and non-volatile compounds. Flavor profiling and electronic tongue analyses further revealed that the flavor characteristics of the crushed and nano-collision groups were similar, but distinctly different from those obtained with steam explosion. Overall, these results provide new insights into the development of efficient spice processing technologies and offer practical guidance for optimizing flavor quality in marinated meat products. Full article

This study presents the synthesis and characterisation of cellulose long chain fatty acid ester films using a novel distillable ionic liquid (IL), 5-methyl-1,5,7-triaza-bicyclo-[4.3.0] non-6-enium acetate [mTBNH][OAc] in combination with DMSO as a cosolvent. The cellulose esters cellulose diacetate (CDA), cellulose laurate (CL), and cellulose palmitate (CP) were fabricated through an evaporation-induced phase separation method (EIPS) and dried under two conditions: conventional oven drying (RO) and vacuum oven drying (VO). The influence of drying conditions on the structural, thermal, and surface properties of the films was evaluated using XRD, TGA, SEM, AFM, and contact angle measurement techniques. XRD confirmed an amorphous structure in all films, with no significant effect on the drying conditions. TGA revealed consistent thermal degradation profiles across all samples, with ester group decomposition accruing between 140 and 250 °C and main cellulose backbone degradation near 350 °C. The SEM cross-section showed a uniform film, devoid of cavities and layered structures. AFM analysis demonstrated that VO-dried films had smoother surfaces compared to RO-dried films, correlating with increased contact angles and enhanced hydrophobicity. A strong inverse relationship between surface roughness and hydrophobicity was observed, particularly in VO-dried samples, although this was not statistically significant due to data variability. Overall, the drying method had minimal impact on the internal structure and thermal stability; it significantly influenced surface morphology and wettability. Full article