Search Results (965)

Faults of heating, ventilation, and air-conditioning (HVAC) systems can cause significant consequences, such as negatively affecting thermal comfort of occupants, energy demand, indoor air quality, etc. Several methods of fault detection and diagnosis (FDD) in building energy systems have been proposed since the late 1980s in order to reduce the consequences of faults in heating, ventilation, and air-conditioning (HVAC) systems. All the proposed FDD methods require laboratory data, or simulated data, or field data. Furthermore, the majority of the recently proposed FDD methods require labelled faulty and normal data to be developed. Thus, providing reliable ground truth data of HVAC systems with different technical characteristics is of great importance for advances in FDD methods for HVAC units. The primary objective of this study is to examine the operational behaviour of a typical single-duct dual-fan constant air volume air-handling unit (AHU) in both faulty and fault-free conditions. The investigation encompasses a series of experiments conducted under Mediterranean climatic conditions in southern Italy during summer and winter. This study investigates the performance of the AHU by artificially introducing seven distinct typical faults: (1) return air damper kept always closed (stuck at 0%); (2) fresh air damper kept always closed (stuck at 0%); (3) fresh air damper kept always opened (stuck at 100%); (4) exhaust air damper kept always closed (stuck at 0%); (5) supply air filter partially clogged at 50%; (6) fresh air filter partially clogged at 50%; and (7) return air filter partially clogged at 50%. The collected data from the faulty scenarios are compared to the corresponding data obtained from fault-free performance measurements conducted under similar boundary conditions. Indoor thermo-hygrometric conditions, electrical power and energy consumption, operation time of AHU components, and all key operating parameters are measured for all the aforementioned faulty tests and their corresponding normal tests. In particular, the experimental results demonstrated that the exhaust air damper stuck at 0% significantly reduces the percentage of time with indoor air relative humidity kept within the defined deadbands by about 29% (together with a reduction in the percentage of time with indoor air temperature kept within the defined deadbands by 7.2%) and increases electric energy consumption by about 13% during winter. Moreover, the measured data underlined that the effects on electrical energy demand and indoor thermo-hygrometric conditions are minimal (with deviations not exceeding 5.6% during both summer and winter) in the cases of 50% clogging of supply air filter, fresh air filter, and return air filter. The results of this study can be exploited by researchers, facility managers, and building operators to better recognize root causes of faulty evidences in AHUs and also to develop and test new FDD tools. Full article

Background/Objectives: Persons with multiple sclerosis (MS) are interested in diet as a second-line approach for disease management. This study examined potential variables that correlate with inaccuracy of self-reported energy intake (EI) in adults with MS. Methods: Twenty-eight participants completed two assessment appointments within a 14-day period that included a standard doubly labeled water (DLW) protocol for estimating total energy expenditure (TEE). The participants reported their EI using the Automated Self-Administered 24 h (ASA24) Dietary Assessment Tool. The primary variables of interest for explaining the discrepancy between TEE and ASA24 EI (i.e., inaccuracy) included cognition (processing speed, visuospatial memory, and verbal memory), hydration status (total body water), and device-measured physical activity. Pearson’s correlations assessed the association between absolute and percent inaccuracy in reporting of EI with outcomes of interest, followed by linear regression analyses for identifying independent correlates. Results: California Verbal Learning Test—Second Edition (CVLT-II) z-scores and light physical activity (LPA) were significantly associated with mean absolute difference in EI (r = –0.53 and r = 0.46, respectively). CVLT-II z-scores and LPA were the only variables significantly associated with mean percent difference in EI (r = –0.48 and r = 0.42, respectively). The regression analyses indicated that both CVLT-II and LPA significantly explained variance in mean absolute difference in EI, and only CVLT-II explained variance for percent difference in EI. Conclusions: The results from this study indicate that verbal learning and memory and LPA are associated with inaccuracy of self-reported EI in adults with MS. This may guide timely research identifying appropriate protocols for assessment of diet in MS. Full article

Among plant-based analogs, fish and seafood analogs (PBFSAs) represent a growing sector. This study analyzed the nutritional quality of PBFSAs in Italy and compared it to their animal-based counterparts. Nutritional declarations, ingredient lists, and claims were collected from PBFSA food labeling. Nutri-Scores of PBSFAs and animal-based counterparts were also determined as nutritional quality indicators. Fifty-one products were collected, with most attributed to tuna, salmon, and cod categories (n = 18, 12, and 14, respectively). Results showed large heterogeneity in nutritional quality, with cod products having higher energy (217 (201–257) kcal/100 g), protein (10.5 (7.9–13.0) g/100 g), and carbohydrate (19.4 (14.2–26.0) g/100 g) levels, while tuna and salmon products had a higher fat content (15.0 (10.0–19.7) and 13.5 (5.0–17.0) g/100 g, respectively). Products with fiber or fat nutrition claims did not necessarily indicate higher fiber or lower fat content, while products with a protein claim had a higher protein content. Most animal-based counterparts, except cod and sturgeon caviar, received an “A” Nutri-Score, and often scored better than the PBSFA due to lower salt content. In conclusion, PBFSAs on the market should not be considered animal product analogs regarding nutritional quality, but drawing definitive conclusions is challenging due to the limited number and high variability of the products. However, these findings provide insights that may improve PBFSA nutritional quality, such as decreasing salt and sugar content, for people trying to incorporate such foods into their diet. Full article

In this study, we comparatively analyzed the variable-temperature crystal structures for two isomorphous salts, [1-benzyl-4-aminopyridinium][M(mnt)₂] (M = Ni or Cu; mnt²⁻ = maleonitriledithiolate; labeled as APy-Ni or APy-Cu). Both salts crystallize in the triclinic P–1 space group at 296 K, comprising linear [M(mnt)₂]⁻ (M = Ni or Cu) tetramers. A magnetostructural phase transition occurs at T_C~190 K in S = ½ APy-Ni at ambient pressure, with a conversion of paramagnetic tetramers into nonmagnetic spin-paired dimers. The discontinuous alteration of cell parameters at T_C signifies the characteristic of first-order phase transition in APy-Ni. No such transition appears in the nonmagnetic APy-Cu within the same temperature vicinity, demonstrating the magnetic interactions promoting the structural phase transition in APy-Ni, which is further reinforced through a comparison of the lattice formation energy between APy-Ni and APy-Cu. The phase transition may bear a resemblance to the mechanisms typically observed in spin-Peierls systems. We further explored the magnetic and phase transition properties of APy-Ni under varying pressures. Significantly, T_C shows a linear increase with rising pressure within the range of 0.003–0.88 GPa, with a rate of 90 K GPa⁻¹, manifesting that the applied pressure promotes the transition from tetramer to dimer. Full article

This study investigates the efficacy of activated carbons (ACs) derived from Tamarix gallica (TG) leaves for glyphosate removal from aqueous solutions. Two chemical activation methods, using phosphoric acid (H₃PO₄) and sulfuric acid (H₂SO₄), were compared to optimize adsorbent performance. The resulting materials, labeled AC-H₃PO₄ and AC-H₂SO₄, were comprehensively characterized using XRD, FTIR, SEM-EDS, BET analysis, and pHpzc determination, revealing distinct physicochemical properties. AC-H₃PO₄ exhibited a larger surface area (580.37 m²/g) and more developed pore structure compared to AC-H₂SO₄ (241.58 m²/g). Adsorption kinetics were best described by the pseudo-first-order model for both adsorbents. Isothermal studies demonstrated that AC-H₃PO₄ followed a pore-filling mechanism best described by the Dubinin–Radushkevich model, while AC-H₂SO₄ showed multilayer adsorption fitting the Freundlich model. Both adsorbents exhibited high glyphosate removal capacities, with maximum Langmuir adsorption capacities of 247.58 mg/g and 235.13 mg/g for AC-H₃PO₄ and AC-H₂SO₄, respectively. The mean free energy of adsorption (E) values confirmed physisorption as the dominant mechanism. This research highlights the potential of TG-derived activated carbons as sustainable and effective adsorbents for glyphosate remediation in water treatment applications, demonstrating the impact of activation methods on adsorption performance. Full article

New psychoactive substances (NPSs) emerged in the 2000s as legal alternatives to illicit drugs and quickly became a huge public health threat due to their easy accessibility online, limited information, and misleading labels. Synthetic cannabinoids and synthetic cathinones are the most reported groups of NPSs. Despite NPSs being widely studied, due to their structural diversity and the constant emergence of novel compounds with unknown properties, the development of new techniques is required to clarify their mode of action and evaluate their toxicological effects. Metabolomics has been a useful tool to evaluate the metabolic effects of several xenobiotics. Herein, a systematic review was performed, following PRISMA guidelines, regarding metabolomic studies on synthetic cathinones and synthetic cannabinoids to evaluate their effects in cellular metabolism. In the studies, in vivo models were the most employed (86%) and the analysis mostly followed untargeted approaches (75%) using LC-MS techniques (67%). Both groups of NPSs seem to primarily interfere with energy metabolism-related pathways. Even though this type of study is still limited, metabolomics holds great promise as a tool to clarify mechanisms of actions, identify biomarkers of exposure, and explain the toxicological effects of NPSs. Full article

To obtain accurate blackbody temperature, emissivity, and waveband measurements, an energy-domain infrared nonuniformity method based on unsupervised learning is proposed. This method exploits the inherent physical correlation within the calibration dataset and sets the average predicted energy-domain value of the same blackbody temperature as the learning goal. Then, the coefficients of the model are learned without theoretical radiance labels by leveraging clustering-based unsupervised learning methodologies. Finally, several experiments are performed on a mid-wave infrared system. The results show that the trained correction network is uniform and produces stable outputs when the integration time and attenuator change within the optimal dynamic range. The maximum change in the image corrected using the proposed algorithm was 1.29%. Full article

Terahertz (THz) molecular fingerprint spectroscopy provides a powerful label-free tool for detecting trace-amount analytes. Introducing extra microstructures such as metasurfaces to confine the field energy is essential to improve the sensitivity. However, the area of analyte film on conventional enhancing metasurfaces must be larger than the beam spot in a free-space measuring setup. Here, we propose a tunable defect cavity of one-dimensional photonic crystal in the combined coaxial waveguide (CCW) and enhance the broadband THz fingerprint of trace analytes on a much smaller area. The peaks of high Q resonances can form a wide absorption spectrum by changing the length of the rubber part of the coaxial waveguide. For the 0.2 µm α-lactose film sample in the frequency range of 0.48–0.58 THz, the absorption enhancement factor of 89.2 times based on the thickness can be achieved and the sample area is about 1/1700 of that in the free-space measurement with the 5 mm beam waist. We first introduce the coaxial waveguide in the terahertz absorption spectra enhancement. With our proposed structure the analyte volume is effectively reduced which is significant in the real application scenario. Full article

Energy consumption modeling in buildings is crucial for calculating energy performance indices and establishing criteria for energy labeling. Different countries utilize diverse approaches to calculate these indices based on energy efficiency regulations and classifications. In recent years, Iran has established energy compliance standards, outlined in Article 19 of the National Building Regulations, to improve the energy efficiency of buildings. This study aims to develop a systematic methodology for assessing energy consumption indicators in residential buildings using the criteria specified in the Iranian National Building Regulations. Our research examines three specific energy standard categories in residential buildings to evaluate the suitability of the energy compliance specifications and identify the distribution of energy indices, rather than relying solely on the fixed values prescribed in the regulations. Initially, three model building shapes were analyzed to demonstrate how different building envelope designs affect energy performance. This study fills a critical research gap by estimating energy consumption indices through a novel methodology that combines regression analysis and Monte Carlo simulation for the three energy classifications specified in Article 19 of the Iranian National Building Regulations. The study employs a permutation approach to evaluate the primary energy consumption indicators and the uncertainties arising from various adjacency configurations. Extensive simulations were conducted, resulting in the development of regression equations that account for the surface area of the building envelope adjacent to the outdoor environment. The Monte Carlo method was used to assess potential fluctuations in the adiabatic area of the building envelope and the area adjacent to the external environment for buildings with varying orientations, allowing for the generation of probability distributions for energy consumption intensities. The sensitivity analysis identified the critical components of the building envelope and their orientation that significantly impact the uncertainty of energy efficiency. The findings revealed that the west and east walls of buildings adjacent to the outdoor environment substantially influence the uncertainty of energy consumption. In contrast, the floor surface and south wall had the least significant effect on annual energy uncertainty. This innovative approach represents a significant advancement in the field. It plays a specific role in energy labeling for buildings by calculating the required standard deviation in energy consumption indices resulting from various envelope adjacencies. This research also has practical implications for building design and energy efficiency measurement. Full article

Oil and natural gas continue to dominate global energy consumption, though a supply gap of 2 million barrels per day (b/d) was reported in the fourth quarter of 2023. Despite a projected increase in global oil supply by 1.2 million b/d in 2023, reaching 101.1 million b/d compared to 2022, reliance on fossil fuels poses challenges for energy security and sustainability. For China, transitioning to clean and renewable energy sources is essential. Biofuel ethanol, with its high octane rating and anti-knock properties, is a promising alternative. This bioenergy sector is expanding globally, with cellulosic ethanol production emerging as a key objective. However, the high production cost of cellulosic ethanol presents a significant challenge to its large-scale adoption. To overcome this barrier, various techniques are being explored to reduce production costs. Among them, advanced characterization methods are used to monitor changes in cellulose, lignin, and hemicellulose during ethanol production in situ, quickly and without surface labeling. These methods provide insights into the factors driving high production costs, enabling targeted improvements. This review focuses on the potential of these characterization techniques to optimize ethanol production processes and improve efficiency. The findings may offer a strategic direction for scaling up cellulosic ethanol production and contribute to the sustainability of energy resources by reducing dependency on fossil fuels. Full article

Wave breaking is a fundamental process in ocean energy dissipation and plays a crucial role in the exchange between ocean and nearshore sediments. Foam, the primary visible feature of wave breaking areas, serves as a direct indicator of wave breaking processes. Monitoring the distribution of foam via remote sensing can reveal the spatiotemporal patterns of nearshore wave breaking. Existing studies on wave breaking processes primarily focus on individual wave events or short timescales, limiting their effectiveness for nearshore regions where hydrodynamic processes are often represented at tidal cycles. In this study, video imagery from a typical low-tide terrace (LTT) beach was segmented into four categories, including the wave breaking foam, using the DeepLabv3+ architecture, a convolutional neural networks (CNNs)-based model suitable for semantic segmentation in complex visual scenes. After training and testing on a manually labelled dataset, which was divided into training, validation, and testing sets based on different time periods, the overall classification accuracy of the model was 96.4%, with an accuracy of 96.2% for detecting wave breaking foam. Subsequently, a heatmap of the wave breaking foam distribution over a tidal cycle on the LTT beach was generated. During the tidal cycle, the foam distribution density exhibited both alongshore variability, and a pronounced bimodal structure in the cross-shore direction. Analysis of morphodynamical data collected in the field indicated that the bimodal structure is primarily driven by tidal variations. The wave breaking process is a key factor in shaping the profile morphology of LTT beaches. High-frequency video monitoring further showed the wave breaking patterns vary significantly with tidal levels, leading to diverse geomorphological features at various cross-shore locations. Full article

The detection of human activities is an important step in automated systems to understand the context of given situations. It can be useful for applications like healthcare monitoring, smart homes, and energy management systems for buildings. To achieve this, a sufficient data basis is required. The presented dataset contains labeled recordings of 25 different activities of daily living performed individually by 14 participants. The data were captured by five multisensors in supervised sessions in which a participant repeated each activity several times. Flawed recordings were removed, and the different data types were synchronized to provide multi-modal data for each activity instance. Apart from this, the data are presented in raw form, and no further filtering was performed. The dataset comprises ambient audio and vibration, as well as infrared array data, light color and environmental measurements. Overall, 8615 activity instances are included, each captured by the five multisensor devices. These multi-modal and multi-channel data allow various machine learning approaches to the recognition of human activities, for example, federated learning and sensor fusion. Full article

This study evaluates the effectiveness of an oil-in-water emulsion formulated from water and seed and nut oils as a substitute for butter in the formulation of brioche bread. First, the selected oils were physicochemically characterized. In the brioche, animal fat was fully and partially replaced, and the effects were analyzed at the physical, chemical, and sensory levels. The new formulations exhibited increased lightness, a softer crumb, improved cohesiveness, and greater expansion compared to the control, resulting in fluffier and lighter brioches. Nutritionally, the seed and nut oil brioches showed a lower fat content and lower energy value, but higher protein and carbohydrate levels. The lipid profile was enhanced, with a higher proportion of unsaturated fatty acids, which positively impacted two heart-friendly indices and increased the vitamin E content. This improvement potentially allows the food industry to apply health claims to product labeling. Regarding sensory analysis, in all cases, the reformulated brioches scored higher than the control sample in terms of external appearance, although there remained a preference for the flavor and aroma of the traditional version, which could be mitigated by adding flavor compounds such as diacetyl. This study differs from previous research by using a seed and nut oil emulsion instead of non-emulsified oils, improving the texture and stability of brioche bread, an achievement not consistently reported in prior studies. Additionally, it emphasizes sustainability by offering a plant-based alternative that addresses the growing consumer demand for vegan and eco-friendly products while providing enhanced nutritional benefits that support potential health claims. Full article

To promote sustainable food choices, it is essential to provide easily understandable information that integrates health, environmental impacts and planetary boundaries. For this purpose, the Planet Health Conformity Index (PHC) was developed and tested. Current labels, such as the Nutri-Score for health and the Eco-Score for environmental impacts, provide separate information, which may result in consumers receiving conflicting messages. The PHC combines these dimensions into a single label, aligning with consumer demand for clearer guidance and fostering sustainable food consumption and development. Methods: The PHC assesses 18 nutrients and five environmental impacts—Global Warming Potential (GWP), cropland use, freshwater use, nitrogen application (N-min) and phosphorus application (P-min)—within the framework of planetary boundaries. Six different algorithm designs, varying in capping and weighting, were tested on 125 food products from the German market. The analysis compared mass-, energy- and multi-nutrient-based functional units. Results: Under mass- and energy-based units, many products meet planetary boundaries. However, incorporating nutrient profiles often leads to exceeding these boundaries (exceedance rate PHC: GWP: 38% of products transgressed the boundary, cropland use: 41%, freshwater use: 27%, N-min: 34%, P-min: 71%). Accordingly, the PHC contextualizes nutritional strengths and weaknesses environmentally. Moreover, it disaggregates the Planetary Health Diet (PHD) at the nutrient level, facilitating adaptation to individual nutritional needs. Conclusions: Traditional food Life Cycle Assessments should include nutrients in the functional unit and consider planetary boundaries to enable more accurate food comparisons. The PHC presented here takes these aspects into account. In addition, its dual-factor approach, integrating health and environmental metrics, ensures broad applicability. Thus, the PHC Index can be applied not only to single food items but also to recipes, dishes, menus and entire diets. Full article

Irumamycin (Iru) is a complex polyketide with pronounced antifungal activity produced by a type I polyketide (PKS) synthase. Iru features a unique hemiketal ring and an epoxide group, making its biosynthesis and the structural diversity of related compounds particularly intriguing. In this study, we performed a detailed analysis of the iru biosynthetic gene cluster (BGC) to uncover the mechanisms underlying Iru formation. We examined the iru PKS, including the domain architecture of individual modules and the overall spatial structure of the PKS, and uncovered discrepancies in substrate specificity and iterative chain elongation. Two potential pathways for the formation of the hemiketal ring, involving either an olefin shift or electrocyclization, were proposed and assessed using ¹⁸O-labeling experiments and reaction activation energy calculations. Based on our findings, the hemiketal ring is likely formed by PKS-assisted double bond migration and TE domain-mediated cyclization. Furthermore, putative tailoring enzymes mediating epoxide formation specific to Iru were identified. The revealed Iru biosynthetic machinery provides insight into the complex enzymatic processes involved in Iru production, including macrocycle sculpting and decoration. These mechanistic details open new avenues for a targeted architecture of novel macrolide analogs through synthetic biology and biosynthetic engineering. Full article