Search Results (6,035)

This study presents a systematic comparative analysis of nine stator current discretization methods within the Model Predictive Current Control (MPCC) framework for Permanent Magnet Synchronous Motors (PMSMs). These methods have generally been examined individually or in limited combinations in previous research, and this holistic and comprehensive comparison constitutes the core contribution of this work by addressing a significant gap in the existing literature. The investigated MPCC methods—Forward Euler (FE), Backward Euler (BE), Midpoint Euler (ME), Fourth-Order Runge–Kutta (RK4), Runge–Kutta Ralston (RKR), Taylor Series (TS), Verlet Integration (VI), Crank–Nicolson (CN), and Adams–Bashforth (AB)—are comprehensively evaluated for their dynamic performance, including speed tracking, torque response, settling time, rise time, overshoot, and Total Harmonic Distortion (THD). Additionally, these analysis results are benchmarked against conventional Proportional–Integral–Derivative (PID) and Field-Oriented Control (FOC) methods. In terms of key performance indicators, the MPCC–RKR method proved optimal for speed tracking under no-load conditions, achieving the lowest overshoot, specifically ranging from 0.097% to 1.450%. Conversely, MPCC–ME and MPCC–CN demonstrated superior transient performance under sudden-load conditions (1.7 Nm), yielding the smallest torque deviations, fastest settling times. Specifically, MPCC-ME recorded the lowest overshoot (1.512%) at the 7 s load step, while MPCC-CN performed best at 9 s (1.220%) and 11 s (1.577%). Among the predictive schemes, the MPCC–RKR method achieved the highest current quality with a minimum THD of 3.69% at nominal speed. Finally, it has been confirmed through the applied statistical analysis techniques that the performance differences among the discretization methods are significant. The comparative analysis examines both the dynamic performance of the methods and the fundamental trade-off between accuracy and computational burden in MPCC design. Simple single-step explicit methods (FE, ME, RKR, VI, AB) offer low computational cost and are well suited for high–sampling-frequency real-time applications, especially with sufficiently small sampling times, whereas more complex multi-step or implicit methods (BE, RK4, TS, CN) may increase the processor load despite their potential gains in accuracy and stability. This study provides practical, evidence-based guidelines for selecting an optimal discretization method by balancing accuracy and dynamic performance requirements for PMSM applications. Full article

Background: Insomnia is prevalent and difficult to treat safely over the long term. Given the role of the microbiota–gut–brain axis in melatonin and hypothalamic–pituitary–adrenal (HPA) regulation, and preclinical evidence for Limosilactobacillus fermentum PS150, we evaluated whether a heat-treated formulation (HT-PS150) could improve sleep and modulate endocrine/circadian markers in adults with poor sleep. Methods: In a randomized, double-blind, placebo-controlled trial, 84 adults aged 20–60 years with PSQI ≥ 5 and ISI < 22 were assigned to receive either placebo or HT-PS150 for eight weeks. Outcomes included patient-reported sleep (PSQI, ISI), anxiety/depression (GAD-7, PHQ-9), quality of life (QLESQ-SF), gastrointestinal symptoms (VAS-GI), wrist actigraphy (Fitbit Inspire 3), and sleep-relevant biomarkers measured from urine, saliva, and/or blood samples (melatonin, cortisol, orexin, serotonin, GABA, and/or norepinephrine). Repeated measures were analyzed using generalized estimating equations. An exploratory proportional regulation analysis classified individual biomarker changes as up- or down-regulated and compared proportions between study arms. Per-protocol analyses required ≥80% compliance. Results: Improvements in the primary outcomes, PSQI and ISI, were observed over time in both groups, while no significant group × time interactions were detected. In exploratory proportional analyses, a higher proportion of participants in the HT-PS150 group exhibited up-regulated nocturnal melatonin secretion and improved daytime plasma orexin levels, as well as a tendency toward greater reductions in nocturnal salivary cortisol compared with placebo. In subgroup analyses with higher baseline insomnia severity (ISI ≥ 8), HT-PS150 was associated with greater improvements in PSQI (notably sleep duration and efficiency) and reduction in anxiety (GAD-7) upon post hoc testing. Conclusions: Although group mean scores on sleep symptom scales did not differ significantly in the full cohort, HT-PS150 appeared to modulate sleep–wake regulation by enhancing nocturnal melatonin secretion, attenuating HPA-axis activity, and stabilizing wakefulness. Clinical benefits were most evident among participants with greater baseline symptom burden, suggesting potential utility in more symptomatic populations. Full article

Semiconductor wafer manufacturing is one of the most complex and data-intensive processes in the industry, encompassing the front-end (FEOL), middle-end (MOL), and back-end (BEOL) stages, involving thousands of interdependent processes. Each stage can introduce potential variability, thereby reducing yield, making metrology and inspection crucial for process control. However, due to capacity, cost, and destructive testing constraints, exhaustive metrology for every wafer or die is impractical. Therefore, this study aims to introduce sampling strategies that have evolved to balance the accuracy, risk, and efficiency of measurement allocation. This review presents a literature review of static, adaptive, and dynamic sampling and discusses recent intelligent sampling techniques. The results show that traditional static sampling provides fixed, rule-based inspection schemes that ensure comparability and compliance but lack responsiveness to process variations. Adaptive sampling introduces flexibility, allowing measurement density to be adjusted based on detected drift, anomalies, or statistical control limits. Building on this, dynamic sampling represents a paradigm shift towards predictive, real-time decision-making driven by machine learning, risk analysis, and digital twin integration. The dynamic framework continuously assesses process uncertainties and prioritizes metrology to maximize information gain, thereby significantly reducing metrology workload without impacting yield or quality. Static, adaptive, and dynamic sampling together constitute a continuous evolution from deterministic control to self-optimizing intelligence. As semiconductor nodes move towards sub-3 nm, this intelligent sampling technology is crucial for maintaining yield, cost competitiveness, and process flexibility in autonomous, data-centric wafer fabs. Full article

Amid accelerating climate change, intensifying urban heat island effects, and rising public demand for livable, walkable streets, there is an urgent practical need for interpretable and actionable evidence on streetscape quality. Yet, research on streetscape quality has often relied on single data sources and linear models, limiting insight into multidimensional perception; evidence from temperate monsoon cities remains scarce. Using Tianjin’s main urban area as a case study, we integrate street-view imagery with remote sensing imagery to characterize satellite-derived environmental indicators at the point scale and examine the following five perceptual outcomes: comfort, aesthetics, perceived greenness, summer heat perception, and willingness to linger. We develop a three-step interpretable assessment, as follows: Elastic Net logistic regression to establish directional and magnitude baselines; Generalized Additive Models with a logistic link to recover nonlinear patterns and threshold bands with Benjamini–Hochberg false discovery rate control and binned probability calibration; and Shapley additive explanations to provide parallel validation and global and local explanations. The results show that the Green View Index is consistently and positively associated with all five outcomes, whereas Spatial Balance is negative across the observed range. Sky View Factor and the Building Visibility Index display heterogeneous forms, including monotonic, U-shaped, and inverted-U patterns across outcomes; Normalized Difference Vegetation Index and Land Surface Temperature are likewise predominantly nonlinear with peak sensitivity in the midrange. In total, 54 of 55 smoothing terms remain significant after Benjamini–Hochberg false discovery rate correction. The summer heat perception outcome is highly imbalanced: 94.2% of samples are labeled positive. Overall calibration is good. On a standardized scale, we delineate optimal and risk intervals for key indicators and demonstrate the complementary explanatory value of street-view imagery and remote sensing imagery for people-centered perceptions. In Tianjin, a temperate monsoon megacity, the framework provides reproducible, actionable, design-relevant evidence to inform streetscape optimization and offers a template that can be adapted to other cities, subject to local calibration. Full article

This study aims to investigate hydrogeochemical characteristics and groundwater quality in the Bashang Area in Chengde and to discuss factors controlling the groundwater quality. A total of 91 groundwater samples were collected and a fuzzy synthetic evaluation (FSE) method was used for assessing groundwater quality. Results show the groundwater chemistry in the study area is predominantly characterized by HCO₃⁻-Ca type waters. Rock weathering processes dominate the hydrogeochemical processes within the study area, while also being influenced by evaporation and concentration effects. The results of the fuzzy evaluation indicate that 94.5% of groundwater samples are of good quality and suitable for drinking (Classes I, II, and III), while 5.5% are of poor quality and unsuitable for drinking (Class IV). Among these, bedrock fissure water exhibited superior quality. Within clastic rock pore water, elevated levels of NO₃⁻ and F⁻ ions were observed in certain localized areas. The exceedance of NO₃^-concentrations stems from agricultural expansion, where the application of nitrogen fertilizers constitutes the primary driver of local nitrate pollution. Excessive F⁻ levels correlate with the region’s indigenous geological background. Fluoride-bearing minerals such as fluorite and biotite are widely distributed throughout the study area. Intensive evaporation concentrates groundwater, while the region’s slow groundwater flow facilitates the accumulation and enrichment of F⁻ within aquifers. Full article

Biased or weighted sampling frequently arises in reliability testing, biomedical survival analysis, and quality-control studies, where the observed data deviate systematically from the target population. This paper develops a unified framework for nonparametric estimation of probability density distribution, hazard rate, and regression functions when the data are subject to biased sampling. The proposed weighted kernel estimators adjust for biasing functions \( w(x) \), enabling asymptotically unbiased estimation under general sampling distortions. Comprehensive theoretical results are provided, including bias-variance decompositions, optimal bandwidth orders, and mean-squared error properties. Extensive numerical simulations and a real-data application to the Channing House dataset demonstrate the practical advantages and robustness of the proposed estimators compared with naïve approaches. The results confirm the method’s theoretical validity and its broad applicability in survival and reliability studies involving biased data. Full article

Modern traffic-monitoring systems increasingly rely on supplemental analytical data to complement video recordings, yet such data are rarely integrated into video containers without altering the original footage. This paper proposes a lightweight audio-based approach for embedding road-condition information using a Least Significant Bit (LSB) steganography framework. The method operates by serializing sensor data, encoding it into the LSB positions of synthetically generated audio, and subsequently compressing the audio track while preserving imperceptibility and video integrity. A series of controlled experiments evaluates how waveform type, sampling rate, amplitude, and frequency influence the storage efficiency and quality of WAV and FLAC stego-audio files. Additional tests examine the impact of embedding capacity and output-quality settings on compression behavior. Results reveal clear trade-offs between audio quality, data capacity, and file size, demonstrating that the proposed framework enables efficient, secure, and scalable integration of metadata into surveillance recordings. The findings establish practical guidelines for deploying LSB-based audio embedding in real traffic-monitoring environments. Full article

The widespread presence of nanoplastics (NPs) in the environment creates a significant and growing concern for global health, with ingestion, inhalation, and dermal contact identified as primary exposure pathways. Despite their documented presence in various environmental matrices and human tissues, robust quantitative data on NP levels remains scarce. This study addresses this critical gap by employing a novel and rapid flow cytometry technique to quantify nanoplastic concentrations in commercial waters, common beverages and infant food, with special focus in packaging influence. Pyrogen-free water was analyzed to establish the negative control for NP concentration, yielding 5.24 ± 2.02 events/µL. Ten commercial waters from natural springs in Spain and France showed NP levels ranging from 1.75 NP/µL to 67.94 NP/µL (mean: 19.90 ± 14.53 NP/µL), where three of those brands showed significantly higher NP numbers than the pyrogen-free water control. Compared to pyrogen-free water, infant formula and cereal porridge showed very low NP concentrations, with values of 10.27 ± 6.85 and 6.78 ± 2.27 events/µL, respectively, following triplicate analyses of six samples. Additional analyses comparing three similar soft drinks across different packaging (can, plastic bottle, or glass bottle) found no significant differences in NP concentration attributable to the container type. NPs, as ubiquitous contaminants, can be ingested by organisms through food and drink. Potential NP contamination in commercial water may be due to factors such as source water contamination, filtration and packaging. The presence of very low concentrations of NPs in infant foods suggests rigorous and effective quality control. Finally, the presence of NP in soft drinks was not affected by the type of packaging. Although soft drinks have higher NP levels than water, the type of packaging had no effect on the presence of NP in these soft drinks. Despite all plastic bottles being made of polyethylene terephthalate, variation in NP accumulation implies that material quality, storage condition, and substantially, water treatment and filtering processes contribute to NP contamination. This research gives evidence for widespread nanoplastic accumulation in bottled water, common beverages and infant formula and sets the stage for demanding research to further investigate sources, health effects, and development into effective quality control and preventive measures for public health. Full article

Encapsulated formulations have emerged as a promising tool for increasing nutrient absorption in the food supplement and cosmetic industries. Although the theoretical amplification factors for improving the bioavailability of encapsulated formulations are very high for poorly soluble active compounds, it has long been known that encapsulation can also enhance the absorption of water-soluble ingredients. These findings have led to the development of new technologies for encapsulating nutrients for use in the food industry. However, accurate quantification of nutrients in encapsulated formulations in the food supplement industry remains a challenge. This study presents the development and validation of novel analytical procedures for determining artemisinin in various food supplement formulations. Three formulations were prepared using different emulsifying procedures for artemisinin encapsulation. High-performance liquid chromatography with UV/Vis detection (HPLC-UV/Vis) was used for analysis. Separation was performed using a Waters ACQUITY Premier BEH C18 column. Specialized sample preparation procedures were designed to efficiently disrupt encapsulation and extract artemisinin for precise quantification. Three different sample preparation procedures were required to accurately determine the artemisinin content in the tested formulations. All methods were validated. The precision, linearity expressed as R², LOD, and LOQ of the chromatographic method were 0.39%, 0.9995, 18 µg/mL, and 26 µg/mL, respectively. Recoveries of the sample preparation methods were above 94%. The developed procedures enable accurate determination of artemisinin in encapsulated formulations, ensuring product quality and safety. These findings suggest that, for quality control of encapsulated food products, specialized analytical procedures for individual formulations may need to be developed and validated. Full article

The upper Xin’an River basin serves as a critical ecological barrier and water-conservation area for the Yangtze River Delta. However, with rapid economic development, nitrogen pollution in the surface waters of this region has become increasingly pronounced. This study analyzed river water samples collected on four occasions from the upper Xin’an River basin for ammonium (NH₄⁺–N), nitrate-nitrogen (NO₃⁻–N), total nitrogen (TN), and nitrate isotopic (δ¹⁵N–NO₃⁻ and δ¹⁸O–NO₃⁻). The sources of nitrate (NO₃⁻) were apportioned using the MixSIAR stable-isotope mixing model, and the spatial distribution of these sources across the basin was characterized. Across the four sampling rounds, the mean TN concentration exceeded 1.3 mg/L, with NO₃⁻–N accounting for over 45% of TN, indicating that nitrate was the dominant inorganic nitrogen species. The δ¹⁵N–NO₃⁻ values ranged from 2.17‰ to 13.0‰, with mean values following the order summer > winter > autumn > spring. The δ¹⁸O–NO₃⁻ values varied from −5.20‰ to −3.48‰, and the average value showed a completely opposite seasonal variation pattern to that of δ¹⁵N–NO₃⁻. Process-based analysis of nitrogen transformations revealed that nitrification predominates during nitrate transport and transformation, whereas denitrification is comparatively weak. MixSIAR-based estimates indicate marked seasonal differences in the source composition of nitrate pollution in the upper Xin’an River basin; NO₃⁻ derives primarily from soil nitrogen (SN) and livestock/sewage manure nitrogen (LSN). LSN was the dominant contributor in spring and summer (49.2% and 59.9%, respectively). SN dominated in autumn (49.2%) and winter (54.1%). Fertilizer nitrogen (FN) contributed more during summer and autumn, when fertilization is concentrated and rainfall is higher. Atmospheric deposition (AN) contributed approximately 1% across all seasons and was thus considered negligible. These findings provide a scientific basis for source control of nitrogen pollution and water-quality management in the upper Xin’an River. Full article

Groundwater is one of the main sources of water supply in tropical developing countries; however, its integrated management is often constrained by limited hydrogeological information and increasing anthropogenic pressures on aquifer systems. This study presents the numerical modeling of groundwater flow in the Neogene–Quaternary aquifer system of the Middle Magdalena Valley (Colombia), focusing on the rural area of Puerto Wilches, which is characterized by strong surface–groundwater interactions, particularly with the Yarirí wetland and the Magdalena River. A three-dimensional model was implemented and calibrated in FEFLOW v.8.1 under steady-state and transient conditions, integrating both primary and secondary data. The dataset included piezometric levels measured with water level meters and automatic loggers, hydrometeorological records, 21 physicochemical and microbiological parameters analyzed in 45 samples collected during three field campaigns under contrasting hydrological conditions, 79 pumping tests, detailed lithological columns from drilled wells, and complementary geological and geophysical models. The results indicate a predominant east–west groundwater flow from the Eastern Cordillera toward the Magdalena River, with seasonal recharge and discharge patterns controlled by the bimodal rainfall regime. Microbiological contamination (total coliforms in 69% of groundwater samples) and nitrate concentrations above 10 mg/L in 21% of wells were detected, mainly due to agricultural fertilizers and domestic wastewater infiltration. Particle tracking revealed predominantly horizontal flow paths, with transit times of up to 800 years in intermediate units of the Real Group and around 60 years in shallow Quaternary deposits, highlighting the differential vulnerability of the system to contamination. These findings provide scientific foundations for strengthening integrated groundwater management in tropical regions under agroindustrial and hydrocarbon pressures and emphasize the need to consolidate monitoring networks, promote sustainable agricultural practices, and establish preventive measures to protect groundwater quality. Full article

Contemporary seed gene bank management emphasizes the importance of understanding seed storage behaviour to maximize the preservation of genetic material. In this context, the patterns of naturally occurring ageing-related changes in physiological and biochemical markers were evaluated by comparing the performance of freshly regenerated seed samples (control) to samples kept under cold storage (CS) for 37 years (original, CS1 samples) and five years (CS2 samples). A significant decline in seed viability and physiological quality—initial seedling development—was directly associated with the duration of cold storage, leading to a marked reduction in seedling vigour index (SVI) performance. Key biochemical markers influencing early seedling growth and vigour included total protein, the glutelins protein fraction, fructose, sucrose, both insoluble-bound and soluble-free phenolics—including phenolic acids, and β-carotene. The CS2 samples, which experienced severe water deficit during the post-zygotic phase, exhibited increased sucrose, insoluble-bound p-coumaric acid (p-CouA), insoluble-bound ferulic acid (FA), and α-tocopherol contents. Conversely, glutelins and glucose contents decreased, while genotype-specific variations were observed in albumins, globulins, fructose, maltose, insoluble-bound caffeic acid, and soluble-free p-CouA, as well as in β+γ- and δ-tocopherol contents. Given the consistent pattern of natural ageing-related changes, β-carotene, lutein+zeaxanthin, insoluble-bound FA, and particularly soluble-free FA emerge as relevant biomarkers for improved monitoring of ageing processes under ex situ conservation. Full article

The central venous catheter (CVC) is essential in the management of pediatric patients, allowing the administration of medications, parenteral nutrition, and other treatments. However, its use carries a high risk of central-line-associated bloodstream infections (CLABSI) and catheter-related bloodstream infections (CRBSI). Advanced chlorhexidine-impregnated dressings have been developed to reduce bacterial colonization, but their effectiveness in the pediatric population remains uncertain. The aim of this review is to evaluate the effectiveness of chlorhexidine-impregnated dressings compared to standard dressings in reducing CLABSI, CRBSI, and CVC colonization in pediatric patients. Randomized clinical trials published between 2005 and 2021 in PubMed, CINAHL, and Embase, in Italian or English, were selected. Methodological quality was assessed using the Joanna Briggs Institute (JBI) checklist. Relevant data were extracted and summarized in tables. Four studies, including a total of 733 pediatric patients (367 intervention, 366 control), were included. None reported a statistically significant reduction in CLABSI/CRBSI with the use of chlorhexidine-impregnated dressings. However, two studies showed a significant reduction in catheter colonization in the intervention group. Current evidence does not support a superior effect of chlorhexidine-impregnated dressings in preventing CLABSI/CRBSI in pediatric patients, although they may reduce catheter colonization. Randomized trials with larger samples and specific methodologies are needed to clarify the true clinical impact. Full article

Quality control of herbal medicinal products (HMPs) is challenging due to their multicomponent composition. For most HMPs, chemical reference standards (CRSs) required for traditional chromatographic and spectral analyses are unavailable. According to USP and Ph. Eur., an exception is valerian tincture, for which highly specific CRSs have been developed. The aim of this study was to use principal component analysis (PCA) and the novel two-dimensional diffuse laser scattering (2D-DLS) method to identify HMPs and their aqueous-ethanolic extracts according to their botanical genera without relying on specific marker compounds. Spectral data were compiled into an extensive library covering a wide wavelength range—from 0.02 nm to 15,000 nm. PCA of the spectral data (UV spectrophotometry, fluorimetry, FTIR spectroscopy, and X-ray diffraction) enabled clustering of samples by individual botanical genera. The most significant information for sample differentiation was provided by wavenumbers of 1400, 1180, and 931 cm⁻¹ in the IR spectra and wavelengths of 450 nm and 672 nm in the UV and fluorescence spectra, respectively. During model cross-validation, all “blind samples” were correctly classified by botanical genus, achieving a non-error rate (NER) of 100%. Furthermore, the unique 2D-DLS method was used to rapidly identify tinctures without opening the glass bottles. Full article

The aim of the study was to evaluate how controlled laboratory addition with Pb, Cd, and Cu affects the fatty acid profile of milk and acid-coagulated cheese from three geographical regions (R1, R2, R3), considering the influence of regional characteristics and the March–April 2025 harvesting period. Comparative analysis of the lipid profile (SFA and UFA) and the ratios between fatty acids showed that region R2 displayed the most balanced nutritional structure, followed by regions R1 and R3. The lipid indices (IA 2.5–4, IT 3–4.4, HH 0.4–0.6, HPI 0.2–0.4) confirmed this pattern across all regions, indicating that R2 is characterized by a favorable, antiatherogenic, and antithrombotic lipid profile, whereas R1 exhibits an intermediate profile and R3 a markedly unbalanced profile. The same trend was observed for the lipid composition of the blank cheese samples. Heavy metal fortification produced major shifts in fatty acid composition and lipid indices. At the maximum level permitted by legislation, the changes were moderate, with SFA increasing from 71% to 77% and essential ω-3 and ω-6 PUFA decreasing, resulting in increased IA and IT and reduced HH and HPI. At 10× the maximum limit, the lipid profile became severely unbalanced: SFA increased to 81%, UFA dropped to 17%, ω-3 fatty acids were nearly absent, and ω-6 levels declined sharply, amplifying their imbalance. These changes were accompanied by a substantial deterioration in all lipid indices. These findings demonstrate that fatty acid composition (SFA, MUFA, PUFA) and lipid parameters (IA, IT, HH, HPI) serve as highly sensitive markers of heavy metal-induced oxidative stress in dairy products. Overall, the study shows that while the fatty acid profiles of milk from different regions reliably indicate both geographical origin and nutritional quality, exposure to heavy metal addition profoundly disrupts these profiles, together with their lipid indices, producing changes significant enough to signal compromised safety and diminished functional value of the resulting cheese. Full article