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Keywords = VCE-004.8

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19 pages, 1615 KiB  
Article
A Stroll Through Saffron Fields, Cannabis Leaves, and Cherry Reveals the Path to Waste-Derived Antimicrobial Bioproducts
by Stefania Lamponi, Roberta Barletta, Michela Geminiani, Alfonso Trezza, Luisa Frusciante, Behnaz Shabab, Collins Nyaberi Nyong’a and Annalisa Santucci
Pharmaceuticals 2025, 18(7), 1003; https://doi.org/10.3390/ph18071003 - 3 Jul 2025
Viewed by 326
Abstract
Background: The accumulation of agri-food waste is a major environmental and economic challenge and converting these by-products into bioactive compounds fits within the circular bioeconomy. This study aimed to evaluate the antimicrobial potential of extracts derived from Cannabis sativa L. leaves (CSE), Crocus [...] Read more.
Background: The accumulation of agri-food waste is a major environmental and economic challenge and converting these by-products into bioactive compounds fits within the circular bioeconomy. This study aimed to evaluate the antimicrobial potential of extracts derived from Cannabis sativa L. leaves (CSE), Crocus sativus tepals (CST), and Prunus avium L. cherry waste (VCE) against four key bacterial species (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa). Methods: Minimum inhibitory concentration (MIC) assays were performed to assess antibacterial activity, while a bioinformatic pipeline was implemented to explore possible molecular targets. Full-proteome multiple sequence alignments across the bacterial strains were used to identify conserved, strain-specific proteins, and molecular docking simulations were applied to predict binding interactions between the most abundant compounds in the extracts and their targets. Results: CSE and CST demonstrated bacteriostatic activity against S. aureus and B. subtilis (MIC = 15.6 mg/mL), while VCE showed selective activity against B. subtilis (MIC = 31.5 mg/mL). CodY was identified as a putative molecular target for CSE and CST, and ChaA for VCE. Docking results supported the possibility of spontaneous binding between abundant extract constituents and the predicted targets, with high binding affinities triggering a strong interaction network with target sensing residues. Conclusions: This study demonstrates the antimicrobial activity of these agri-food wastes and introduces a comprehensive in vitro and in silico workflow to support the bioactivity of these agri-food wastes and repurpose them for innovative, eco-sustainable applications in the biotechnology field and beyond. Full article
(This article belongs to the Special Issue Sustainable Approaches and Strategies for Bioactive Natural Compounds)
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14 pages, 9656 KiB  
Article
A CMOS-Based Power Management Circuit with a Reconfigurable Rectifier and an LDO Regulator for Piezoelectric Energy Harvesting in IoT Applications
by Suany E. Vázquez-Valdés, Primavera Argüelles-Lucho, Rosa M. Woo-García, Edith Osorio-de-la-Rosa, Francisco López-Huerta and Agustín L. Herrera-May
Nanoenergy Adv. 2025, 5(2), 7; https://doi.org/10.3390/nanoenergyadv5020007 - 14 May 2025
Viewed by 577
Abstract
The technological advances in internet of things (IoT) devices have raised the demand for cost-efficient and sustainable energy sources. Piezoelectric energy harvesters (PEHs) are promising low-cost and eco-friendly energy sources but require robust power management circuits (PMCs) for voltage conversion and regulation. This [...] Read more.
The technological advances in internet of things (IoT) devices have raised the demand for cost-efficient and sustainable energy sources. Piezoelectric energy harvesters (PEHs) are promising low-cost and eco-friendly energy sources but require robust power management circuits (PMCs) for voltage conversion and regulation. This work presents a complementary metal–oxide–semiconductor (CMOS)-based PMC, integrating a reconfigurable AC-DC rectifier and a low-dropout (LDO) voltage regulator designed using 0.18 µm Taiwan semiconductor manufacturing company (TSMC) CMOS technology. This design includes an intermediate coupling stage to reduce voltage drop and improve the transfer efficiency of the PMC. In addition, we develop numerical simulations of the PMC performance, achieving a voltage conversion efficiency (VCE) between 72.8% and 43.21% using input voltages from 0.7 V to 2.8 V with a 50 kΩ load resistance. Compared to previous designs, the proposed circuit demonstrates improved stability, reduced area (66.28 mm2), and extended operating voltage range, allowing its potential application for ultra-low-power IoT nodes. This PMC contributes to the development of autonomous systems with reduced battery dependency and enhanced sustainability. Full article
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25 pages, 5069 KiB  
Article
Bioactive Potential of Sweet Cherry (Prunus avium L.) Waste: Antioxidant and Anti-Inflammatory Properties for Sustainable Applications
by Luisa Frusciante, Collins Nyaberi Nyong’a, Alfonso Trezza, Behnaz Shabab, Tommaso Olmastroni, Roberta Barletta, Pierfrancesco Mastroeni, Anna Visibelli, Maurizio Orlandini, Luisa Raucci, Michela Geminiani and Annalisa Santucci
Foods 2025, 14(9), 1523; https://doi.org/10.3390/foods14091523 - 26 Apr 2025
Cited by 3 | Viewed by 833
Abstract
This study presents an innovative approach to the sustainable valorization of industrial sweet cherry (Prunus avium L.) waste from the Vignola Region, Italy, transforming what is typically discarded into a high-value bioactive resource. Unlike conventional extractions, our hydroethanolic extract (VCE) was obtained [...] Read more.
This study presents an innovative approach to the sustainable valorization of industrial sweet cherry (Prunus avium L.) waste from the Vignola Region, Italy, transforming what is typically discarded into a high-value bioactive resource. Unlike conventional extractions, our hydroethanolic extract (VCE) was obtained from the entire cherry waste, including the pericarp, pulp, and stone, as generated by industrial processing. This full-fruit extraction strategy represents a novel and efficient use of agricultural by-products, aligning with circular bioeconomy principles. Sweet cherries are known for their phenolic richness, and spectrophotometric assays (TPC, TFC, reducing power, DPPH, and ABTS) confirmed the extract’s antioxidant capacity. In vitro studies using RAW 264.7 macrophages revealed no cytotoxic effects (MTT assay), along with significant anti-inflammatory activity, evidenced by reduced ROS and NO production and downregulation of iNOS and COX-2. Western blotting showed inhibition of NF-κB nuclear translocation and MAPK pathway signaling. Additionally, agarose gel electrophoresis showed protection against oxidative DNA damage. UPLC-MS/MS analysis identified sakuranetin, aequinetin, and dihydrowogonin as the most representative compounds in VCE. Molecular docking simulations revealed strong and specific binding affinities of these compounds to NF-κB p65 and key MAPK targets. These findings highlight whole sweet cherry waste—including the pit—as a potent and sustainable source of bioactive compounds with promising nutraceutical and pharmaceutical applications. Full article
(This article belongs to the Section Food Nutrition)
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12 pages, 12855 KiB  
Case Report
Transcatheter Aortic Valve Replacement Reverses Heyde Syndrome: A Case Report of Severe Aortic Stenosis and Gastrointestinal Bleeding
by Claudiu Florin Rășinar, Alexandru Tîrziu, Rebeca Ionela Rășinar, Florin Gîru, Cristian Mornoș, Dan Gaiță, Constantin Tudor Luca and Daniel Miron Brie
J. Clin. Med. 2025, 14(8), 2819; https://doi.org/10.3390/jcm14082819 - 19 Apr 2025
Viewed by 646
Abstract
Background: Heyde syndrome is a rare condition characterized by the triad of severe aortic stenosis, gastrointestinal bleeding, and acquired type 2A von Willebrand syndrome. This case report highlights the diagnostic and therapeutic approach for a 72-year-old woman presenting with exertional chest pain, dyspnea, [...] Read more.
Background: Heyde syndrome is a rare condition characterized by the triad of severe aortic stenosis, gastrointestinal bleeding, and acquired type 2A von Willebrand syndrome. This case report highlights the diagnostic and therapeutic approach for a 72-year-old woman presenting with exertional chest pain, dyspnea, fatigue, and a history of melena. Methods: The diagnostic workup revealed severe microcytic anemia and a reduced vWF ristocetin-to-antigen ratio. Imaging confirmed severe degenerative aortic stenosis, while video capsule endoscopy identified angiodysplasia and telangiectasias in the small bowel as the source of gastrointestinal bleeding. Following evaluation by a multidisciplinary Heart Team, the patient underwent transcatheter aortic valve replacement (TAVR) with an Evolut Fx self-expanding prosthesis. Results: Post-procedural echocardiography showed mild paravalvular regurgitation. The patient’s clinical course was favorable, with resolution of anemia and no further gastrointestinal bleeding episodes. Conclusions: Heyde syndrome requires a high index of suspicion for diagnosis in patients with severe aortic stenosis and unexplained anemia or gastrointestinal bleeding. TAVR offers an effective treatment option that not only resolves valvular pathology, but also mitigates associated bleeding risks. Full article
(This article belongs to the Special Issue Clinical Advances in Valvular Heart Diseases)
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9 pages, 3517 KiB  
Case Report
A Study on the Diagnostic Approach Using Real-Time Video Capsule Endoscopy in Dogs with Acute Vomiting
by Hyomi Jang, Young Joo Kim and Dong-In Jung
Animals 2025, 15(7), 1056; https://doi.org/10.3390/ani15071056 - 5 Apr 2025
Cited by 1 | Viewed by 828
Abstract
This study aimed to evaluate the efficiency and sensitivity of real-time video capsule endoscopy (RT-VCE) when detecting surgical and nonsurgical gastric lesions in dogs that presented with acute vomiting. Additionally, the patient tolerance and the utility of the RT-VCE data for clinical decision-making [...] Read more.
This study aimed to evaluate the efficiency and sensitivity of real-time video capsule endoscopy (RT-VCE) when detecting surgical and nonsurgical gastric lesions in dogs that presented with acute vomiting. Additionally, the patient tolerance and the utility of the RT-VCE data for clinical decision-making were assessed. Eleven client-owned dogs with an acute onset of vomiting were included. Each dog received an antiemetic and antacid before undergoing an RT-VCE (MC1200, MiroCam®, Intromedic, Seoul, Republic of Korea). We independently reviewed the RT-VCE images to assess the image quality, detect gastric lesions, and make clinical decisions. The time taken to reach a diagnosis and the inter-clinician agreement were evaluated. RT-VCEs were successfully completed in all the dogs, with a mean time to diagnosis of 21.82 ± 15.26 min (range: 1–48 min). Both clinicians reached unanimous agreement on the RT-VCE findings. Five dogs were diagnosed with gastric foreign bodies and underwent surgical removal, while the remaining six were diagnosed with gastritis, a gastric ulcer or erosion, or hemorrhages, which were managed medically. No adverse effects, including vomiting, were observed after the capsule administration. RT-VCE proved to be an effective, accurate, and well-tolerated diagnostic method for evaluating gastric conditions in dogs with acute vomiting. Its rapid diagnostic capability and non-invasive nature make it a valuable modality in emergency veterinary settings. Full article
(This article belongs to the Section Veterinary Clinical Studies)
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15 pages, 1804 KiB  
Article
Brucella ceti in Common Dolphins (Delphinus delphis) in Portugal—Characterization of First Isolates
by Sandra Cavaco, Miguel L. Grilo, Ricardo Dias, Mónica Nunes, Pedro Pascoal, Marcelo Pereira, Catarina Fogaça, Ana Beatriz Costa, Sofia Pardal and Ana Cristina Ferreira
Animals 2025, 15(3), 374; https://doi.org/10.3390/ani15030374 - 28 Jan 2025
Viewed by 2062
Abstract
This study investigates Brucella ceti infection in marine mammals stranded along the Lisbon and Tagus Valley coast between 2022 and mid-2024, marking the first report of Brucella presence in Portuguese waters. Out of 59 examined marine mammals, B. ceti was isolated in three [...] Read more.
This study investigates Brucella ceti infection in marine mammals stranded along the Lisbon and Tagus Valley coast between 2022 and mid-2024, marking the first report of Brucella presence in Portuguese waters. Out of 59 examined marine mammals, B. ceti was isolated in three common dolphins (5.1%), a prevalence rate consistent with previous studies from other coastlines. PCR-based detection indicated a higher infection rate (23.7%), suggesting an underestimation of the prevalence of B. ceti infection in this population. Multi-locus Sequence Typing (MLST) and Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA) revealed distinct genetic profiles and close relationships to B. ceti strains from the Atlantic, supporting the hypothesis of specific host-adapted lineages in dolphins. Virulence genes, including those for host interaction (bspE, btpB) and intracellular survival (virB7, vceA), were consistent across isolates, highlighting the pathogenic potential. Additionally, antimicrobial resistance (AMR) genes, such as mprF and efflux proteins (bepC-G), were also identified. These findings underscore the need for further research and surveillance to understand B. ceti transmission, host range, and impacts on Atlantic cetaceans, as well as to develop effective diagnostic and management strategies to mitigate infection risks in marine environments. Full article
(This article belongs to the Special Issue Zoonotic Diseases: Etiology, Diagnosis, Surveillance and Epidemiology)
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13 pages, 965 KiB  
Article
The Role of Small Bowel Capsule Endoscopy in Determining the Treatment Strategy for Duodenal Follicular Lymphoma: A Single-Center Retrospective Study
by Donghoon Kang, Gi-June Min, Tong Yoon Kim, Young-Woo Jeon, Yukyung Cho, Jae Myung Park, Joo Hyun O, Byung-Ock Choi, Gyeongsin Park and Seok-Goo Cho
Diagnostics 2025, 15(2), 193; https://doi.org/10.3390/diagnostics15020193 - 15 Jan 2025
Viewed by 1040
Abstract
Objectives: In this single-center retrospective study, we aimed to verify the extent of duodenal follicular lymphoma (DFL) and investigate the role and clinical significance of video capsule endoscopy (VCE) in the treatment process. Methods: We analyzed the clinical and imaging data [...] Read more.
Objectives: In this single-center retrospective study, we aimed to verify the extent of duodenal follicular lymphoma (DFL) and investigate the role and clinical significance of video capsule endoscopy (VCE) in the treatment process. Methods: We analyzed the clinical and imaging data of 40 patients diagnosed with DFL. Results: Imaging workup and bone marrow biopsies revealed DFL only in the gastrointestinal tract (stage I) in 22 patients and in local lymph nodes (stage II1), distant lymph nodes (stage II2), pancreas (stage II2Epancreas), and extranodal regions (stage IV) in 1, 3, 1, and 13 patients, respectively. Fifteen of the 23 patients with localized (stages I and II1) DFL underwent VCE for comprehensive small bowel evaluation, which revealed lesion extension beyond the duodenum in 10 patients (66.7%). A watch-and-wait strategy was implemented for one patient and systemic chemotherapy was administered to the remaining nine. Of the eight patients without VCE, seven and one received radiotherapy and observation, respectively. Nine of the 23 patients (39.1%) received systemic treatment based on positive VCE results. Only one of the 17 patients with advanced-stage DFL (stages II2 and IV) accepted radiotherapy; 16 underwent systemic chemotherapy. During follow-up (median, 48.4 months), two relapse events occurred in the advanced stage, with no lymphoma-associated deaths. DFL tends to be indolent and has favorable outcomes. Conclusions: Proactive VCE for diagnosing DFL is recommended to determine small bowel involvement, which may influence subsequent treatment decisions. Full article
(This article belongs to the Special Issue Endoscopy in Diagnosis of Gastrointestinal Disorders—2nd Edition)
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18 pages, 3603 KiB  
Article
Prediction of a Hydrogen Vapor Cloud Explosion with a Barrier Wall Using Various Machine Learning Methods
by Hyunseok Min and Hyungseok Kang
Processes 2024, 12(12), 2946; https://doi.org/10.3390/pr12122946 - 23 Dec 2024
Viewed by 979
Abstract
Hydrogen is considered the next energy to replace fossil fuels, but it must be handled with care given that it is a flammable gas. A barrier wall is an effective way to mitigate the effect of an explosion, and to build a safe [...] Read more.
Hydrogen is considered the next energy to replace fossil fuels, but it must be handled with care given that it is a flammable gas. A barrier wall is an effective way to mitigate the effect of an explosion, and to build a safe barrier wall, research on hydrogen explosions is necessary. Experiments and CFD (computational fluid dynamics) are two commonly used methods, but both are costly to use under any condition. Machine learning can be used to enhance the data from experiments and CFD as the trained model can predict explosion pressure levels very rapidly under various conditions. We propose the prediction of a hydrogen VCE (vapor cloud explosion) with a barrier wall using various machine learning methods. This research uses CFD simulation data from KAERI (Korea Atomic Energy Research Institute) as training data. MLP (multi-layer perceptron), LSTM (long short-term memory), and the Transformer architectures are used to train the hydrogen VCE and are compared. In our research, MLP produces the best score among all learning processes, with an R2 value exceeding 0.97, outperforming both LSTM and Transformer in terms of accuracy and speed. The trained machine learning model can be used to build safe barrier walls in hydrogen refueling stations. Evaluating the safe distance from the barrier wall and evaluating the optimal position of the barrier wall are possible usages. Full article
(This article belongs to the Section Energy Systems)
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24 pages, 6400 KiB  
Article
Innovative Modeling of IMU Arrays Under the Generic Multi-Sensor Integration Strategy
by Benjamin Brunson, Jianguo Wang and Wenbo Ma
Sensors 2024, 24(23), 7754; https://doi.org/10.3390/s24237754 - 4 Dec 2024
Cited by 4 | Viewed by 1478
Abstract
This research proposes a novel modeling method for integrating IMU arrays into multi-sensor kinematic positioning/navigation systems. This method characterizes sensor errors (biases/scale factor errors) for each IMU in an IMU array, leveraging the novel Generic Multisensor Integration Strategy (GMIS) and the framework for [...] Read more.
This research proposes a novel modeling method for integrating IMU arrays into multi-sensor kinematic positioning/navigation systems. This method characterizes sensor errors (biases/scale factor errors) for each IMU in an IMU array, leveraging the novel Generic Multisensor Integration Strategy (GMIS) and the framework for comprehensive error analysis in Discrete Kalman filtering developed through the authors’ previous research. This work enables the time-varying estimation of all individual sensor errors for an IMU array, as well as rigorous fault detection and exclusion for outlying measurements from all constituent sensors. This research explores the feasibility of applying Variance Component Estimation (VCE) to IMU array data, using separate variance components to characterize the performance of each IMU’s gyroscopes and accelerometers. This analysis is only made possible by directly modeling IMU inertial measurements under the GMIS. A real land-vehicle kinematic dataset was used to demonstrate the proposed technique. The a posteriori positioning/attitude standard deviations were compared between multi-IMU and single IMU solutions, with the multi-IMU solution providing an average accuracy improvement of ca. 14–16% in the estimated position, 30% in the estimated roll and pitch, and 40% in the estimated heading. The results of this research demonstrate that IMUs in an array do not generally exhibit homogeneous behavior, even when using the same model of tactical-grade MEMS IMU. Furthermore, VCE was used to compare the performance of three IMU sensors, which is not possible under other IMU array data fusion techniques. This research lays the groundwork for the future evaluation of IMU array sensor configurations. Full article
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12 pages, 5447 KiB  
Article
Quantitative Risk Assessment of Steam Reforming Process by Hydrogen Generator, Using PHAST Model
by Jongseok Lee, Hyunjun Kwak and Seungho Jung
Energies 2024, 17(22), 5704; https://doi.org/10.3390/en17225704 - 14 Nov 2024
Cited by 2 | Viewed by 1329
Abstract
This study applied a risk assessment technique to the steam reforming process in hydrogen production facilities to generate baseline data for preparing safety protocols in related workplaces. To this end, consequence analysis (CA) was conducted using DNV-PHAST v.8.9., focusing on the reforming process, [...] Read more.
This study applied a risk assessment technique to the steam reforming process in hydrogen production facilities to generate baseline data for preparing safety protocols in related workplaces. To this end, consequence analysis (CA) was conducted using DNV-PHAST v.8.9., focusing on the reforming process, which operates at the highest temperature and pressure among related processes. This study predicted jet fire damage resulting from the total failure of a 65 mm syngas pipe at the rear end of the reformer, with a projected flame length of up to 23.6 m based on a radiant heat of 5 kW/m2. As per the assessment, a vapor cloud explosion (VCE) caused damage of up to 42.6 m at an overpressure of 0.07 bar (1 psi), while a flash fire had an impact range of approximately 12.7 m based on hydrogen’s LFL (lower flammable limit). This quantitative risk assessment of the general steam reforming process provides valuable basic data for the design and operation of related facilities. Full article
(This article belongs to the Special Issue Safety of Hydrogen Energy: Technologies and Applications)
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17 pages, 5029 KiB  
Article
Research on the Calculation Method and Diffusion Pattern of VCE Injury Probability in Oil Tank Group Based on SLAB-TNO Method
by Xixiang Zhang, Yufeng Yang, Wanzhou Cheng, Guohua Chen, Qiming Xu and Tingyu Gao
Processes 2024, 12(11), 2459; https://doi.org/10.3390/pr12112459 - 6 Nov 2024
Viewed by 1049
Abstract
Accidental leakage from oil–gas storage tanks can lead to the formation of liquid pools. These pools can result in vapor cloud explosions (VCEs) if combustible vapors encounter ignition energy. Conducting accurate and comprehensive consequence analyses of such explosions is crucial for quantitative risk [...] Read more.
Accidental leakage from oil–gas storage tanks can lead to the formation of liquid pools. These pools can result in vapor cloud explosions (VCEs) if combustible vapors encounter ignition energy. Conducting accurate and comprehensive consequence analyses of such explosions is crucial for quantitative risk assessments (QRAs) in industrial safety. In this study, a methodology based on the SLAB-TNO model to calculate the overpressure resulting from a VCE is presented. Based on this method, the consequences of the VCE accident considering the gas cloud concentration diffusion are studied. The probit model is employed to evaluate casualty probabilities under varying environmental and operational conditions. The effects of key parameters, including gas diffusion time, wind speed, lower flammability limit (LFL), and environment temperature, on casualty diffusion are systematically investigated. The results indicate that when the diffusion time is less than 100 s, the VCE consequences are significantly more severe due to the rapid spread of the gas cloud. Furthermore, increasing wind speed accelerates gas dispersion, reducing the spatial extent of casualty isopleths. The LFL is shown to have a direct impact on both the mass and diffusion of the flammable gas cloud, with higher LFL values shifting the explosion’s epicenter upward. The environmental temperature promotes gas diffusion in the core area and increases the mass of the combustible gas cloud. These findings provide critical insights for improving the safety protocols in oil and gas storage facilities and can serve as a valuable reference for consequence assessment and emergency response planning in similar industrial scenarios. Full article
(This article belongs to the Special Issue New Insight in Enhanced Oil Recovery Process Analysis and Application)
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15 pages, 6404 KiB  
Article
Modeling and Performance Analysis of Variable Cycle Engine with Ceramic Matrix Composite Turbine Blades
by Baokuo Li, Sheng Huang, Huaixu Yan, Xiaobo Zhang, Kun Du and Zhanxue Wang
Aerospace 2024, 11(11), 886; https://doi.org/10.3390/aerospace11110886 - 28 Oct 2024
Cited by 1 | Viewed by 1874
Abstract
To meet the requirements of future aircraft for power systems, the turbine inlet temperatures of aero engines are gradually increasing. Ceramic matrix composite (CMC), with its higher thermal limit, has become the preferred material for the turbine blades of variable cycle engines (VCEs). [...] Read more.
To meet the requirements of future aircraft for power systems, the turbine inlet temperatures of aero engines are gradually increasing. Ceramic matrix composite (CMC), with its higher thermal limit, has become the preferred material for the turbine blades of variable cycle engines (VCEs). However, the impact of CMC turbine blades on the performance of a VCE is still unknown. In this research project, the comprehensive cooling-efficiency characteristics of CMC are determined through a fluid–solid coupling calculation; a cooling calculation model for turbine blades is established, and cooling airflow solution and control technology (CSCT) for an air system is developed. Additionally, a VCE simulation model is established to analyze the influence of CMC turbine blades on the cooling airflow of the air system and the overall performance of the engine. The results show that, for the design condition, the CMC turbine blade can reduce the cooling airflow of the air system by approximately 10%, and the net thrust is increased by 6.07–7.98%. For the off-design conditions, with the CSCT, the specific fuel consumption can be reduced by 3.06–5.73% while ensuring that the engine net thrust remains unchanged. A comprehensive analysis of the performance for both the design point and off-design points indicates that the use of CMC for high-pressure turbine (HPT) guide vanes and rotor blades yields significant performance benefits, while the performance improvement from the use of CMC for low-pressure turbine (LPT) rotor blades is minimal. Full article
(This article belongs to the Section Aeronautics)
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17 pages, 5704 KiB  
Article
Study of the Micro-Vibration Response and Related Vibration Isolation of Complex Traffic Load-Induced Experimental Buildings
by Feifan Feng, Yunjun Lu and Weiwei Chen
Symmetry 2024, 16(10), 1328; https://doi.org/10.3390/sym16101328 - 9 Oct 2024
Cited by 2 | Viewed by 1128
Abstract
In view of the high-sensitivity vibration effect of precision instrument laboratory buildings under the influence of surrounding traffic loads, field micro-vibration tests under various working conditions were carried out based on actual projects. Combined with numerical simulation, measured data served as input loads [...] Read more.
In view of the high-sensitivity vibration effect of precision instrument laboratory buildings under the influence of surrounding traffic loads, field micro-vibration tests under various working conditions were carried out based on actual projects. Combined with numerical simulation, measured data served as input loads to simulate the vibration effect of various traffic loads on the floor of a building structure, and the structural vibration laws under the comprehensive action of various loads were analyzed. The vibration isolation effect of the isolation ditch on the oblique orthogonal load was investigated according to the corresponding safety index. The results show that the main frequency components of the site vibration frequency caused by various traffic loads are approximately 25 Hz and that the root-mean-square speed value is stable below VC-E, which meets the design requirements. Under the comprehensive action of multiple loads, the site structure will produce a vibration amplification effect, which is obvious when all types of loads are distributed symmetrically and the curve distribution is controlled by load factors with large amplitudes. The isolation effect of a small isolation ditch is best when it is located close to the source and the building. The depth of the isolation ditch must be greater than the maximum depth of the source to achieve better results, and the width has little influence. The effect of a small isolation trench on vertical vibration is poor, and the oblique orthogonal triaxial load has a counteracting effect on the vertical component. Thus, additional structural vibration isolation measures are needed. The research results provide a reference for engineering vibration isolation, damping measures, and structural design. Full article
(This article belongs to the Special Issue Symmetry in Civil Transportation Engineering)
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19 pages, 8059 KiB  
Article
CFD Analysis of the Effects of a Barrier in a Hydrogen Refueling Station Mock-Up Facility during a Vapor Cloud Explosion Using the radXiFoam v2.0 Code
by Hyung-Seok Kang, Keun-Sang Choi, Hyun-Woo Lee and Chul-Hee Yu
Processes 2024, 12(10), 2173; https://doi.org/10.3390/pr12102173 - 6 Oct 2024
Viewed by 1325
Abstract
A CFD (computational fluid dynamics) analysis to investigate the effects of the installation of a barrier in a hydrogen refueling station (HRS) mock-up facility, with a dummy vehicle and dispensers in the vapor cloud region, during a hydrogen-air explosion using a gas mixture [...] Read more.
A CFD (computational fluid dynamics) analysis to investigate the effects of the installation of a barrier in a hydrogen refueling station (HRS) mock-up facility, with a dummy vehicle and dispensers in the vapor cloud region, during a hydrogen-air explosion using a gas mixture volume of 70.16 m3 was conducted to determine whether the radXiFoam v2.0 code with the established analysis methodology to predict the peak overpressure can be utilized to evaluate the safety of a HRS with such a barrier installed in a large city in the Republic of Korea. The radXiFoam v2.0 code was developed on the basis of the XiFoam solver in the open-source CFD software OpenFOAM-v2112 by modifying C++ source codes in several libraries and governing equations so as to ensure effective calculations of the hydrogen-air chemical reaction and radiative heat transfer through water vapor in a humid air environment and to remove unnecessary warning messages that arise when using the radXiFoam v1.0 code. First, we conducted a validation analysis on the basis of measured overpressure datasets from a near field to a far field of a vapor cloud explosion (VCE) site in the HRS mock-up facility to evaluate the uncertainty in prediction datasets by radXiFoam v2.0. After this validation analysis, we undertook CFD sensitivity calculations by installing barriers with heights of 2.1 m and 4.2 m at a horizontal distance of 2.3 m from the VCE region in the grid model used for the validation analysis to assess the effects of these barriers on reducing the peak overpressure of the blast wave. From these calculations, we judged that the radXiFoam v2.0 code can accurately simulate the effects of the barrier during a VCE, as the calculated overpressure reduction values according to the barrier height are reasonable on the basis of previous validation results from Stanford Research Institute’s explosion test with such a barrier. The results herein imply that the radXiFoam v2.0 code is feasible for use in HRS safety when barrier installation must meet the technical regulations of the Korea Gas Safety Corporation in a large city. Full article
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21 pages, 2778 KiB  
Article
Could Capsule Endoscopy Be Useful in Detection of Suspected Small Bowel Bleeding and IBD-10 Years of Single Center Experience
by Jelena Martinov Nestorov, Aleksandra Sokic-Milutinovic, Aleksandra Pavlovic Markovic and Miodrag Krstic
Diagnostics 2024, 14(9), 862; https://doi.org/10.3390/diagnostics14090862 - 23 Apr 2024
Viewed by 1980
Abstract
A retrospective study in patients who underwent video capsule endoscopy (VCE) between 2006 and 2016 was conducted in the Clinic for gastroenterology and Hepatology, University Clinical Center of Serbia. A total of 245 patients underwent VCE. In 198 patients the indication was obscure [...] Read more.
A retrospective study in patients who underwent video capsule endoscopy (VCE) between 2006 and 2016 was conducted in the Clinic for gastroenterology and Hepatology, University Clinical Center of Serbia. A total of 245 patients underwent VCE. In 198 patients the indication was obscure gastrointestinal bleeding (OGIB), with 92 patients having overt and the other 106 occult bleeding. The remaining 47 patients underwent VCE due to suspected small bowel (SB) disease (i.e., Von Hippel–Lindau syndrome, familial adenomatous polyposis, Peutz Jeghers syndrome, Crohn’s disease, prolonged diarrhea, abdominal pain, congenital lymphangiectasia, protein-losing enteropathy, tumors, refractory celiac disease, etc.). VCE identified a source of bleeding in 38.9% of patients (in the obscure overt group in 48.9% of patients, and in the obscure occult group in 30.2% of patients). The most common findings were angiodysplasias, tumors, Meckel’s diverticulum and Crohn’s disease. In the smaller group of patients with an indication other than OGIB, 38.3% of patients had positive VCE findings. The most common indication is OGIB, and the best candidates are patients with overt bleeding; patients with IBD should be evaluated in this setting. Full article
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