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Search Results (271)

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Keywords = principle components analysis (PCA)

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25 pages, 1988 KB  
Article
Application of Artificial Neural Networks and Decision Trees for Optimizing Industrial-Scale Composting of Biodegradable Waste to Support Sustainable Waste Management
by Bartosz Gręziak, Ewa Syguła and Andrzej Białowiec
Sustainability 2026, 18(17), 8702; https://doi.org/10.3390/su18178702 - 25 Aug 2026
Viewed by 305
Abstract
Sustainable management of biodegradable waste is a key component of the circular economy and resource recovery strategies. Composting is a complex biological process whose efficiency depends on numerous operational and physicochemical factors. Under industrial conditions, continuous laboratory monitoring of waste properties is often [...] Read more.
Sustainable management of biodegradable waste is a key component of the circular economy and resource recovery strategies. Composting is a complex biological process whose efficiency depends on numerous operational and physicochemical factors. Under industrial conditions, continuous laboratory monitoring of waste properties is often limited by time and cost constraints, necessitating reliable predictive tools to support process management. This study investigates the use of artificial neural networks (ANNs), decision trees (C&RT), and principal component analysis (PCA) for optimizing the composting of biodegradable waste under industrial-scale conditions. The research was conducted at a full-scale mechanical–biological treatment facility in Poland processing both the organic fraction mechanically derived from mixed municipal waste and separately collected biowaste. A dataset containing 23 records was developed from operational parameters (airflow, water addition, turning frequency, and process duration) and physicochemical properties of composted waste, including moisture content (MC), loss on ignition (LOI), total organic carbon (TOC), respiration activity (AT4), and higher heating value (HHV). The best-performing neural model achieved a predictive accuracy of 0.999 (coefficient of determination R2 in the test set). For each of the neural networks, goodness of fit indices were also determined: MAE and RMSE. PCA confirmed strong relationships among key waste properties, while decision tree analysis identified airflow as the dominant operational factor affecting MC, LOI, and TOC, whereas turning frequency had the strongest influence on AT4. The results demonstrate that machine learning tools can effectively support industrial composting optimization by predicting operational parameters required to achieve desired waste stabilization characteristics, providing practical decision-support solutions for composting plant operators. It is recommended to implement single-output MLP models for dynamic, real-time process control and C&RT rules as emergency procedures. This study aligns with circular economy principles and the Sustainable Development Goals by demonstrating the potential of artificial intelligence to enhance sustainable biodegradable waste management, resource recovery, and industrial composting performance. Full article
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30 pages, 6203 KB  
Review
Role of Hyperspectral Imaging in Forensic Science
by Jitendra Shit and V. M. Manikandan
Algorithms 2026, 19(8), 629; https://doi.org/10.3390/a19080629 - 28 Jul 2026
Viewed by 730
Abstract
Hyperspectral imaging (HSI) is a state-of-the-art analytical technique that combines the use of conventional digital imaging and spectroscopy to capture both spatial and spectral information simultaneously in hundreds of narrow, adjacent wavelength bands. In recent decades, the progress in HSI has been rapid, [...] Read more.
Hyperspectral imaging (HSI) is a state-of-the-art analytical technique that combines the use of conventional digital imaging and spectroscopy to capture both spatial and spectral information simultaneously in hundreds of narrow, adjacent wavelength bands. In recent decades, the progress in HSI has been rapid, and the technique has been increasingly utilized in forensic sciences, demonstrating its superiority to standard analytical techniques with respect to being non-invasive and contact-free. Although numerous forensic HSI articles have appeared in the literature in recent years, there has yet to emerge a systematic comparison of HSI performance, instrumentation, and cross-domain translational difficulties within forensic science. This review fills this important gap by analyzing the principles, instrumentations, methods of HSI data processing, and potential applications of HSI in forensics in the context of nine important fields: blood stain analysis and estimation of blood age; document authentication; fingerprint detection and enhancement; gunshot residue (GSR) analysis; analysis of trace evidences; detection of biological fluids; postmortem interval (PMI) estimation; determination of bruise age; and multidisciplinary applications. Comparative analysis of over fifty peer-reviewed articles published from 2010 to 2026 in HSI-based forensic sciences is provided herein, with classification accuracies between 81% and 100%. The use of chemometric and machine-learning methods, such as principal component analysis (PCA), support vector machines (SVM), partial least square discriminant analysis (PLS-DA), and Convolutional Neural Networks (CNNs), is carefully analyzed. Some problems concerning standardization, legal acceptance, data sets available, and forensic application are considered alongside future developments of HSI technology. Full article
(This article belongs to the Section Evolutionary Algorithms and Machine Learning)
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30 pages, 2106 KB  
Article
Embedding-Dependent Performance of Variational Quantum Reinforcement Learning for Intrusion Detection Under Dimensionality Constraints
by Raid Anis Kerkatou, Hacene Belhadef, Aicha Eutamene and Svetlana Petrova Stefanova
Electronics 2026, 15(13), 2853; https://doi.org/10.3390/electronics15132853 - 30 Jun 2026
Viewed by 340
Abstract
Network intrusion detection systems (IDS) operate in high-dimensional feature spaces under evolving attack patterns and asymmetric misclassification costs, where false negatives represent a critical security risk. Reinforcement learning (RL) offers a natural mechanism for encoding domain-specific misclassification costs directly into the learning signal [...] Read more.
Network intrusion detection systems (IDS) operate in high-dimensional feature spaces under evolving attack patterns and asymmetric misclassification costs, where false negatives represent a critical security risk. Reinforcement learning (RL) offers a natural mechanism for encoding domain-specific misclassification costs directly into the learning signal through reward shaping, enabling cost-sensitive policy optimization in adaptive streaming environments. However, the integration of variational quantum models into RL-based IDS remains insufficiently explored. This work investigates a variational quantum reinforcement learning (VQRL) framework for intrusion detection, in which parameterized quantum circuits are employed to model the policy function. We adopt an RL formulation primarily as a principled cost-sensitive optimization approach rather than to exploit sequential state dependencies, and we employ Instantaneous Quantum Polynomial (IQP) embedding as a quantum feature encoding strategy. The study analyzes how embedding expressivity interacts with varying levels of dimensionality reduction via principal component analysis (PCA) on the CICIDS2017 dataset. Experiments demonstrate that VQRL-IQP achieves high recall and reduces false negative rates in moderately high-dimensional feature spaces compared to a classical RL baseline. This improvement is accompanied by an increase in false positive rates, reflecting a trade-off shaped jointly by the reward structure and the structural properties of IQP encoding. Statistical validation across five independent runs confirms the consistency of these trends. Importantly, no general quantum advantage in accuracy or computational efficiency is claimed; rather, the results indicate that VQRL-IQP offers a distinct error trade-off that is operationally valuable in security-critical scenarios where minimizing missed attacks is the primary objective. Full article
(This article belongs to the Special Issue AI in Cybersecurity, 3rd Edition)
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16 pages, 5740 KB  
Article
Assessment of Cooked Meatballs’ Edibility Using Calibrated MOS Sensors and Microbiological Validation
by Luigi Masi, Revathy Gurusamy, Daniel Garcia-Romeo, Andreas Schütze, Rafael Pagán and Christian Bur
Chemosensors 2026, 14(7), 148; https://doi.org/10.3390/chemosensors14070148 - 30 Jun 2026
Cited by 1 | Viewed by 567
Abstract
Food waste is often driven by consumer uncertainty about the spoilage of stored food, especially for cooked meal leftovers where microbial growth is the main concern. We analyzed whether metal oxide semiconductor (MOS) gas sensors placed inside ordinary food containers can monitor the [...] Read more.
Food waste is often driven by consumer uncertainty about the spoilage of stored food, especially for cooked meal leftovers where microbial growth is the main concern. We analyzed whether metal oxide semiconductor (MOS) gas sensors placed inside ordinary food containers can monitor the edibility of leftovers, specifically cooked meatballs. Sensors were operated using temperature cycling to enhance selectivity, and cycle-aligned features were extracted. A prior calibration campaign produced information used to map cycle-aligned features into estimated gas concentrations for relevant VOCs. Total viable counts, which represent the growth of total number of spoilage microorganisms, were analyzed on days 0, 5 and 7 to determine the food’s freshness. Both the raw sensor features and the calibration-derived gas concentration estimates were analyzed with principal component analysis (PCA) and evaluated with a leave-one-sensor-out (LOSO) binary classifier for multiple food containers. PCA on the calibrated gas estimates revealed a dominant axis that consistently tracks food degradation over time across various containers. LOSO classification accuracy improved from 81.7% using raw sensor features to 87.8% using calibrated gas concentration estimates. These findings represent a proof of principle that calibrated MOS sensor systems can robustly support in situ edibility assessment for cooked food. Full article
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19 pages, 32560 KB  
Article
Metabolomic Profiling Reveals Intestinal Metabolic Reprogramming in Chinese Tongue Sole (Cynoglossus semilaevis) Against Vibrio harveyi Infection
by Weiwei Zheng, Yadong Chen, Tengteng Wang, Huizong Han, Zhihong Liu, Dong Xu, Xiaoqing Xi and Tao Yang
Animals 2026, 16(11), 1715; https://doi.org/10.3390/ani16111715 - 3 Jun 2026
Viewed by 932
Abstract
Vibriosis caused by V. harveyi led to high mortality and enormous economic losses in Chinese tongue sole aquaculture. However, the intestinal metabolic alterations associated with V. harveyi infection remain unclear. In this study, ultra-performance liquid chromatography–mass spectrometry (LC-MS)-based metabolomics was used to investigate [...] Read more.
Vibriosis caused by V. harveyi led to high mortality and enormous economic losses in Chinese tongue sole aquaculture. However, the intestinal metabolic alterations associated with V. harveyi infection remain unclear. In this study, ultra-performance liquid chromatography–mass spectrometry (LC-MS)-based metabolomics was used to investigate the variations in intestinal metabolic phenotypes among control, susceptible, and resistant Chinese tongue sole after 7 days of V. harveyi infection. Histopathological examination revealed severe intestinal damages in susceptible fish, whereas resistant fish displayed only mild changes. Principle components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) revealed distinct separation of intestinal metabolites among three groups. A total of 2948 metabolites were identified, with 437 and 794 differential metabolites detected in the resistant and susceptible groups, respectively. The KEGG enrichment analysis revealed that resistant individuals primarily enriched amino acid metabolism and TCA cycle to support immunity and tissue repair, whereas susceptible individuals enriched sphingolipid and cGMP-PKG signaling pathways linked to inflammation and apoptosis, indicating divergent metabolic strategies during V. harveyi infection. Thirty-two potential metabolite biomarkers (area under the curve (AUC) = 1) were screened, which could effectively distinguish susceptible and resistant individuals. Correlation analysis further demonstrated strong interactions among these metabolite markers, host immune-related differentially expressed genes (DEGs), and intestinal microbes. Collectively, our findings reveal distinct intestinal histopathological changes and metabolic reprogramming in resistant and susceptible individuals following V. harveyi infection and identify a set of candidate biomarkers, providing a theoretical foundation for developing targeted prevention strategies and immune enhancement approaches against V. harveyi infection in Chinese tongue sole. Full article
(This article belongs to the Special Issue Advances in Reproductive Physiology of Fish)
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27 pages, 1691 KB  
Article
Incorporation of Citrus Peel-Derived Bioactive Compounds into a Fish-Based Food Product: Effects on Quality, Antioxidant Potential, Microbial Safety and Sensory Attributes
by Elena-Iuliana Flocea, Gabriela Mihalache, Bianca-Georgiana Anchidin, Ioana Gucianu, Marius-Mihai Ciobanu, Florina Stoica, Giulia Pascon, Daniel-Florin Lipșa and Paul-Corneliu Boișteanu
Foods 2026, 15(10), 1741; https://doi.org/10.3390/foods15101741 - 14 May 2026
Cited by 3 | Viewed by 758
Abstract
Fish-derived products are extensively acknowledged for their substantial role in fostering balanced diets and supporting a healthy way of life. This research is aimed at formulating, analyzing and evaluating a fish-based food product. The methodology adopted in this study adheres to contemporary food [...] Read more.
Fish-derived products are extensively acknowledged for their substantial role in fostering balanced diets and supporting a healthy way of life. This research is aimed at formulating, analyzing and evaluating a fish-based food product. The methodology adopted in this study adheres to contemporary food safety standards, prioritizing the utilization of minimal technological processes and natural ingredients, a focus that is gaining prominence within contemporary industrial practices. Thus, the proposal for a formulation obtained by integrating powders and extracts from plant byproducts (Citrus) represents a concrete application direction with real potential for commercialization. The product has been enriched with biocomponents derived from orange peel, namely orange extract (OE) and orange peel powder (PPO). The research focused on product development and the in situ evaluation of the effects of OE and PPO. The physicochemical composition, bioactive compound content, and antioxidant activity were evaluated, along with the microbiological status under post-opening refrigeration conditions, in order to simulate actual consumer use. In addition, the product’s color parameters and sensory attributes were analyzed. The results highlight significant potential for the development of a clean-label fish-based product, characterized by a simplified and easily implementable formulation, aligned with current production and consumption requirements. Compared to the control sample, both OE and PPO significantly influenced the analyzed parameters. Differences in physicochemical composition were observed in the experimental samples. In addition, PPO increased the antioxidant activity of the samples and the profile of bioactive compounds. Microbiological analysis, performed on day 0 and after 3 and 7 days of storage at 4 °C showed opening, confirmed the absence of Escherichia coli and Staphylococcus aureus in all samples and had an influence on the growth of fungi. The acceptability of fish-based products is often limited by odor perception, which is one of the main factors leading to consumer rejection. Sensory evaluation demonstrated that citrus-enriched samples were distinguished by the perception of particular sensory attributes. This formulation presents a practical solution to address this constraint, thereby enhancing the product’s sensory acceptability. The integration of OE and PPO yielded a more harmonized sensory profile, as evidenced by elevated hedonic scores and an intermediate placement in both principal component analysis (PCA) and external preference mapping. This research furnishes a thorough characterization of a fish-based food product, underscoring its potential as a viable option for balanced dietary regimens. Simultaneously, the findings support the product’s adherence to sustainability principles through the utilization of bioactive compounds sourced from plant byproducts, thus satisfying contemporary requirements for foods that possess an optimal nutritional profile and a diminished environmental footprint. Full article
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23 pages, 3446 KB  
Article
Quality by Design-Based Scale-Up and Industrial Development of Turmeric Extract-Loaded Nanostructured Lipid Carriers
by Wipanan Jandang, Phennapha Saokham, Chidchanok Prathumwon, Siriporn Okonogi and Chadarat Ampasavate
Pharmaceutics 2026, 18(4), 492; https://doi.org/10.3390/pharmaceutics18040492 - 16 Apr 2026
Cited by 2 | Viewed by 1232
Abstract
Background/Objectives: A robust and scalable manufacturing framework for lipid-based nanocarriers remains a critical challenge, particularly for labile phytochemicals such as curcuminoids in turmeric. This study presents an integrated Quality by Design (QbD)-driven and Outcome-Based Design (ObD) strategy to establish a scalable, resource-efficient [...] Read more.
Background/Objectives: A robust and scalable manufacturing framework for lipid-based nanocarriers remains a critical challenge, particularly for labile phytochemicals such as curcuminoids in turmeric. This study presents an integrated Quality by Design (QbD)-driven and Outcome-Based Design (ObD) strategy to establish a scalable, resource-efficient manufacturing process for curcuminoids-loaded nanostructured lipid carriers (NLCs). Methods: To overcome the limitations of conventional multivariate design of experiments (DOE), which require extensive experimental runs, a risk-based, knowledge-driven single-factor screening approach was employed. Guided by risk assessment tools, including Ishikawa diagrams and failure mode considerations, 12 representative processing conditions were selected to define the design space. Critical quality attributes (CQAs), namely, particle size, polydispersity index (PDI), and zeta potential, were predefined to establish a robust control strategy. A two-step homogenization process—high-shear homogenization (HSH) for pre-emulsification followed by high-pressure homogenization (HPH) for nanoscale refinement—was systematically optimized. Results: Multivariate data analysis using principal component analysis (PCA) and hierarchical cluster analysis (HCA) identified key critical process parameters (CPPs), particularly HSH speed, processing time, and HPH cycles, as dominant factors influencing nanoparticle characteristics. The optimized 1-h process enabled successful scale-up of NLCs from 100 g to 5000 g, demonstrating the capability to generate nanosized particles within 100–500 nm. The combined HSH–HPH approach produced smaller, more uniform nanoparticles with high encapsulation efficiency and physical stability, outperforming HSH alone. Conclusions: Overall, this study establishes a practical and industrially viable framework that integrates QbD principles with data-driven optimization tools, for enabling reliable translation from laboratories to semi-industrial production. Full article
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18 pages, 1227 KB  
Article
Royal Jelly as a Natural Endocrine Modulator of Serum Estradiol Levels in Juvenile Sterlets (Acipenser ruthenus)
by Dragoș Moraru, Ersilia Alexa, Adrian Grozea, Violeta Igna, Sandra Antonia Mihailov, Christine Neagu and Silvia Pătruică
Molecules 2026, 31(7), 1210; https://doi.org/10.3390/molecules31071210 - 6 Apr 2026
Viewed by 925
Abstract
The present study investigates the role of royal jelly as a natural endocrine modulator of serum estradiol levels in juvenile sterlets (Acipenser ruthenus), a species of major interest for sustainable aquaculture. The experiment was conducted over a period of 85 days [...] Read more.
The present study investigates the role of royal jelly as a natural endocrine modulator of serum estradiol levels in juvenile sterlets (Acipenser ruthenus), a species of major interest for sustainable aquaculture. The experiment was conducted over a period of 85 days under controlled recirculating system conditions, using four dietary treatments (n = 30 fish per group): a control group and three groups supplemented with 1%, 3%, and 5% royal jelly. Serum estradiol concentrations were determined by high-performance liquid chromatography (HPLC), while biometric assessment included the determination of total length (L), standard length (Sl), maximum body height (H), body circumference (C), and body mass (BM). Royal jelly supplementation significantly increased serum estradiol levels in a dose-dependent manner (p < 0.05), with the highest values recorded in the 5% group compared to the control. The proportion of individuals with non-detectable estradiol levels decreased progressively with increasing supplementation level. Biometric analysis revealed moderate effects on growth parameters, with no statistically significant differences among groups for most traits (p > 0.05), except for maximum body height, which showed a significant overall effect (ANOVA, p = 0.0089). Principal Component Analysis (PCA) highlighted the relative independence between endocrine variability and growth dynamics. Overall, the findings support the potential of royal jelly as a natural endocrine modulator of serum estradiol, representing a promising and environmentally friendly alternative to synthetic hormonal substances used in aquaculture. This approach may contribute to the development of innovative nutritional strategies for endocrine control and the optimization of biological performance in sturgeons, in accordance with the principles of sustainable aquaculture. Full article
(This article belongs to the Special Issue Applied Chemistry in Europe, 2nd Edition)
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23 pages, 3361 KB  
Article
Parameterized Multimodal Feature Fusion for Explainable Seizure Detection Using PCA and SHAP
by Abdul-Mumin Khalid, Musah Sulemana and Wahab Abdul Iddrisu
AppliedMath 2026, 6(3), 49; https://doi.org/10.3390/appliedmath6030049 - 18 Mar 2026
Viewed by 968
Abstract
Multimodal epileptic seizure detection using physiological biosignals remains challenging due to signal noise, inter-subject variability, weak cross-modal alignment, and the limited interpretability of many machine learning models. To address these challenges, this study proposes a parameterized multimodal feature-fusion framework that unifies normalization, modality [...] Read more.
Multimodal epileptic seizure detection using physiological biosignals remains challenging due to signal noise, inter-subject variability, weak cross-modal alignment, and the limited interpretability of many machine learning models. To address these challenges, this study proposes a parameterized multimodal feature-fusion framework that unifies normalization, modality weighting, and nonlinear cross-modal interaction within a single mathematical representation. Four fusion parameters, the fusion exponent ρ, interaction weight (δ), normalization factor (λ), and the cross-modal interaction term (η), are introduced at the feature-fusion level, while all classifiers retain their original learning mechanisms. The framework is evaluated using synchronized EEG, ECG, EMG, and accelerometer signals from 120 subjects, segmented into 2 s windows at 512 Hz and analyzed using twelve classical and deep learning classifiers. Principal Component Analysis (PCA) applied to the fused feature space reveals improved class separability compared to unimodal representations, with EEG exhibiting the strongest intrinsic discrimination and peripheral modalities contributing complementary structure when fused. SHapley Additive exPlanations (SHAP) further identify entropy as the most influential feature across all modalities, followed by RMS and energy, yielding physiologically coherent attributions. Quantitative performance evaluation and ablation analysis confirm that the observed improvements arise from the proposed representation design rather than classifier-specific modifications. Unlike existing architecture-dependent fusion strategies, the proposed method introduces a mathematically parameterized feature-space formulation that enhances separability and interpretability without modifying classifier architectures, thereby establishing a representation-driven paradigm for explainable multimodal seizure detection. These results demonstrate that mathematically principled feature-space modeling can simultaneously enhance predictive performance and interpretability, providing a transparent and robust foundation for explainable multimodal seizure detection. Full article
(This article belongs to the Topic A Real-World Application of Chaos Theory)
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21 pages, 17132 KB  
Article
An Exploratory Study of FT-NIR Spectroscopy and Class-Wise PCA for Quality Screening of Mee Rough Tea
by Wenfei Zou, Li Luo, Xiangyang Yu and Weibin Hong
Spectrosc. J. 2026, 4(1), 7; https://doi.org/10.3390/spectroscj4010007 - 18 Mar 2026
Viewed by 1000
Abstract
To address the need for rapid evaluation of large batches of Mee rough tea during the acceptance stage, this study aims to explore the feasibility of using portable Fourier transform near-infrared (FT-NIR) spectroscopy for preliminary quality screening. The goal is to develop a [...] Read more.
To address the need for rapid evaluation of large batches of Mee rough tea during the acceptance stage, this study aims to explore the feasibility of using portable Fourier transform near-infrared (FT-NIR) spectroscopy for preliminary quality screening. The goal is to develop a rapid, non-destructive, and relatively objective assessment method that is applicable to practical acceptance scenarios. This work represents an exploratory proof-of-concept study rather than a finalized industrial grading solution. Spectral data of three reference categories and thirty-six test samples were collected in the wavelength range of 1350–2500nm using a portable FT-NIR spectrometer. The sample configuration was designed to simulate practical acceptance sampling conditions. The spectra were preprocessed using multiplicative scatter correction, first-order derivative transformation, and mean-centering. Independent principal component analysis (PCA) models were constructed for each reference category to achieve class-wise feature dimensionality reduction, with cumulative explained variance exceeding 95%. Distance thresholds were determined using the 3σ principle based on Euclidean distance and Mahalanobis distance. Classification was performed by distance-based matching between test samples and reference categories. Under optimized matching degree threshold settings of 0.9 and 0.7, the two distance models achieved classification accuracies of 86.11% and 83.33%, respectively, demonstrating the feasibility of the proposed approach. The main contribution of this study is the application of class-wise PCA combined with distance-based discrimination to the acceptance stage of Mee rough tea. The proposed framework provides a practical exploratory approach for rapid screening and offers a preliminary digital tool to support acceptance decisions. Further validation using larger and more diverse datasets will be necessary prior to large-scale industrial implementation. Full article
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30 pages, 2381 KB  
Review
A Macroeconomic and Technological Perspective on the Sustainable Valorization of Plant-Based Waste Streams in European States
by Simona Gavrilaș
Sustainability 2026, 18(5), 2163; https://doi.org/10.3390/su18052163 - 24 Feb 2026
Viewed by 766
Abstract
The transition toward a circular, sustainable food industry requires efficient valorization of biological resources while minimizing environmental pressures. This critical review focuses on the sustainable use of bioactive compounds recovered from plant-based waste and side streams through green extraction technologies as a core [...] Read more.
The transition toward a circular, sustainable food industry requires efficient valorization of biological resources while minimizing environmental pressures. This critical review focuses on the sustainable use of bioactive compounds recovered from plant-based waste and side streams through green extraction technologies as a core element of circular economy strategies in the agri-food sector. By integrating EUROSTAT indicators, a multivariate analytical approach, combining correlation analysis, principal component analysis (PCA), K-means clustering, and agglomerative hierarchical clustering (AHC), was employed to assess the relationships between greenhouse gas emissions, energy productivity, economic activity, and environmental employment across European States. The results reveal two main structural dimensions that explain nearly 90% of the total variability, reflecting the balance between economic scale and environmental pressure, and the role of energy efficiency in supporting sustainable consumption. Cluster analysis identified converging economies with greater circularity potential and structurally distinct economies that require targeted transition pathways. These findings emphasize that circular bioeconomy solutions, such as integrating green-extracted bioactive compounds into food products, must be tailored to each country’s economic and energy profile. This review highlights the strategic role of circular economy principles in strengthening the sustainability, resilience, and innovation capacity of the European food industry. Full article
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16 pages, 4695 KB  
Article
A Principal Component Analysis Framework for Evaluating Mining-Induced Risk: A Case Study of a Chilean Underground Mine
by Felipe Muñoz, Rodrigo Estay, Claudia Pavez-Orrego and Gonzalo Nelis
Appl. Sci. 2026, 16(3), 1211; https://doi.org/10.3390/app16031211 - 24 Jan 2026
Viewed by 749
Abstract
Mining-induced seismicity presents significant challenges to the safety and operational continuity of underground mines, particularly in deep and highly stressed environments. This study proposes a methodological framework for seismic risk evaluation inspired by predictive-maintenance principles and applied to a high-resolution microseismic catalog from [...] Read more.
Mining-induced seismicity presents significant challenges to the safety and operational continuity of underground mines, particularly in deep and highly stressed environments. This study proposes a methodological framework for seismic risk evaluation inspired by predictive-maintenance principles and applied to a high-resolution microseismic catalog from a Chilean underground mine. Using a combination of data filtering and correlation analyses, we identify the seismic parameters that control the most variability in the dataset: moment magnitude, frequency corner, and both dynamic and static stresses. Based on this, we perform a Principal Component Analysis (PCA), which clearly demonstrates the physical interconnection between the selected parameters, thereby helping to better characterize the seismic events and the mining environment. Using these results, a PCA-based risk map is constructed, enabling the delineation of zones with different levels of seismic risk. Additionally, a temporal tracking of potentially hazardous seismicity is included. The proposed methodology demonstrates that microseismic behavior can be effectively represented in a reduced-dimension space, offering a promising foundation for predictive and data-driven risk-assessment tools capable of supporting real-time decision-making in underground mining operations. Full article
(This article belongs to the Special Issue Machine Learning Applications in Seismology: 2nd Edition)
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41 pages, 9730 KB  
Review
In-Vehicle Gas Sensing and Monitoring Using Electronic Noses Based on Metal Oxide Semiconductor MEMS Sensor Arrays: A Critical Review
by Xu Lin, Ruiqin Tan, Wenfeng Shen, Dawu Lv and Weijie Song
Chemosensors 2026, 14(1), 16; https://doi.org/10.3390/chemosensors14010016 - 4 Jan 2026
Cited by 3 | Viewed by 3511
Abstract
Volatile organic compounds (VOCs) released from automotive interior materials and exchanged with external air seriously compromise cabin air quality and pose health risks to occupants. Electronic noses (E-noses) based on metal oxide semiconductor (MOS) micro-electro-mechanical system (MEMS) sensor arrays provide an efficient, real-time [...] Read more.
Volatile organic compounds (VOCs) released from automotive interior materials and exchanged with external air seriously compromise cabin air quality and pose health risks to occupants. Electronic noses (E-noses) based on metal oxide semiconductor (MOS) micro-electro-mechanical system (MEMS) sensor arrays provide an efficient, real-time solution for in-vehicle gas monitoring. This review examines the use of SnO2-, ZnO-, and TiO2-based MEMS sensor arrays for this purpose. The sensing mechanisms, performance characteristics, and current limitations of these core materials are critically analyzed. Key MEMS fabrication techniques, including magnetron sputtering, chemical vapor deposition, and atomic layer deposition, are presented. Commonly employed pattern recognition algorithms—principal component analysis (PCA), support vector machines (SVM), and artificial neural networks (ANN)—are evaluated in terms of principle and effectiveness. Recent advances in low-power, portable E-nose systems for detecting formaldehyde, benzene, toluene, and other target analytes inside vehicles are highlighted. Future directions, including circuit–algorithm co-optimization, enhanced portability, and neuromorphic computing integration, are discussed. MOS MEMS E-noses effectively overcome the drawbacks of conventional analytical methods and are poised for widespread adoption in automotive air-quality management. Full article
(This article belongs to the Special Issue Detection of Volatile Organic Compounds in Complex Mixtures)
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21 pages, 738 KB  
Article
Development of a Mediterranean Diet Recipe Index (MedRI)
by Sofia G. Florença, Filipa P. Costa, Raquel P. F. Guiné, Maria João Lima, Edite Teixeira-Lemos and Cristina A. Costa
Nutrients 2025, 17(24), 3868; https://doi.org/10.3390/nu17243868 - 11 Dec 2025
Viewed by 1138
Abstract
Background/Objectives: The Mediterranean Diet (MD) is globally recognized for its nutritional, environmental, and cultural value. Although several indices assess adherence to the MD and its food environments, none evaluate the alignment of individual recipes with MD principles. This study aimed to develop and [...] Read more.
Background/Objectives: The Mediterranean Diet (MD) is globally recognized for its nutritional, environmental, and cultural value. Although several indices assess adherence to the MD and its food environments, none evaluate the alignment of individual recipes with MD principles. This study aimed to develop and validate the Mediterranean Diet Recipe Index (MedRI), a novel scoring tool designed to quantify the concordance of recipes with MD guidelines. Methods: The MedRI was conceptualized through a comprehensive literature review and expert panel assessment, integrating two main dimensions: consumption context and recipe composition. The index evaluates ingredient selection, preparation methods, and food group inclusion, with criteria adapted to specific recipe categories. Validation was conducted using a structured questionnaire administered to 244 adults living in Portugal. Statistical analyses included descriptive statistics, Spearman correlations, intra-class correlation coefficients (ICCs), Cohen’s kappa, Chi-square tests, Cramer’s V, and principal component analysis (PCA). Results: Validation results demonstrated strong internal consistency and construct validity, confirming the reliability and applicability of the MedRI in assessing recipe alignment with MD principles. Conclusions: The MedRI thus represents a reliable and innovative tool to assess and promote culinary practices consistent with the MD. It holds potential applications in nutrition education, public health policymaking, and gastronomic research, supporting the advancement of sustainable and health-promoting dietary models. Full article
(This article belongs to the Special Issue EAT-Lancet: A Smart and Sustainable Way of Eating)
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19 pages, 1922 KB  
Article
Validated Transfer Learning Peters–Belson Methods for Survival Analysis: Ensemble Machine Learning Approaches with Overfitting Controls for Health Disparity Decomposition
by Menglu Liang and Yan Li
Stats 2025, 8(4), 114; https://doi.org/10.3390/stats8040114 - 10 Dec 2025
Viewed by 1131
Abstract
Background: Health disparities research increasingly relies on complex survey data to understand survival differences between population subgroups. While Peters–Belson decomposition provides a principled framework for distinguishing disparities explained by measured covariates from unexplained residual differences, traditional approaches face challenges with complex data patterns [...] Read more.
Background: Health disparities research increasingly relies on complex survey data to understand survival differences between population subgroups. While Peters–Belson decomposition provides a principled framework for distinguishing disparities explained by measured covariates from unexplained residual differences, traditional approaches face challenges with complex data patterns and model validation for counterfactual estimation. Objective: To develop validated Peters–Belson decomposition methods for survival analysis that integrate ensemble machine learning with transfer learning while ensuring logical validity of counterfactual estimates through comprehensive model validation. Methods: We extend the traditional Peters–Belson framework through ensemble machine learning that combines Cox proportional hazards models, cross-validated random survival forests, and regularized gradient boosting approaches. Our framework incorporates a transfer learning component via principal component analysis (PCA) to discover shared latent factors between majority and minority groups. We note that this “transfer learning” differs from the standard machine learning definition (pre-trained models or domain adaptation); here, we use the term in its statistical sense to describe the transfer of covariate structure information from the pooled population to identify group-level latent factors. We develop a comprehensive validation framework that ensures Peters–Belson logical bounds compliance, preventing mathematical violations in counterfactual estimates. The approach is evaluated through simulation studies across five realistic health disparity scenarios using stratified complex survey designs. Results: Simulation studies demonstrate that validated ensemble methods achieve superior performance compared to individual models (proportion explained: 0.352 vs. 0.310 for individual Cox, 0.325 for individual random forests), with validation framework reducing logical violations from 34.7% to 2.1% of cases. Transfer learning provides additional 16.1% average improvement in explanation of unexplained disparity when significant unmeasured confounding exists, with 90.1% overall validation success rate. The validation framework ensures explanation proportions remain within realistic bounds while maintaining computational efficiency with 31% overhead for validation procedures. Conclusions: Validated ensemble machine learning provides substantial advantages for Peters–Belson decomposition when combined with proper model validation. Transfer learning offers conditional benefits for capturing unmeasured group-level factors while preventing mathematical violations common in standard approaches. The framework demonstrates that realistic health disparity patterns show 25–35% of differences explained by measured factors, providing actionable targets for reducing health inequities. Full article
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