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Impact of pulsed electric fields and ultrasound on the frying characteristics of sweet potato chips
No full textInternational audienceSweet potato fries and chips are a popular snack worldwide. However, as the high oil and acrylamide contents in fried foods may contribute to increased risks of obesity, diabetes, hypertension and cancer, methods to reduce these harmful components have become a research focus. In this study, the impacts of pulsed electric fields (PEF) and ultrasound (US) on the frying kinetics and characteristics of sweet potato chips were investigated. The intensity of PEF treatment was set at E = 1.0 kV/cm with a total duration of tPEF = 0.2 s; the energy applied in the PEF pre-treatment was 9.47 ± 0.5 kJ/kg. US treatment was performed at 53 kHz (10 s ON/1 s OFF), 180 W, and 25 °C for 30 min. Low-field nuclear magnetic resonance (LF–NMR) revealed that both PEF and US pre-treatment influence the binding force between water molecules in sweet potatoes. Reducing sugars in raw products treated with PEF, US, and PEF + US were significantly (p < 0.05) reduced by 33.3 %, 20.0 %, and 53.3 %, respectively. The first-order kinetics model provided a good fit for water evaporation during frying. The PEF, US, and PEF + US treatments resulted in oil content reductions of 32.3 %, 37.0 %, and 40.3 %, respectively, compared with the untreated samples. Pre-treatments also improved the color and textural characteristics of fried sweet potato chips. Furthermore, the acrylamide content was reduced by 55.28 % (549 µg/kg) with PEF + US pre-treatment. These results reveal a potential method for producing high-quality fried products
"Innovation in Pieces": A study of the externalization process of FDA approved drugs from 2010-2020
No full textThis study investigates the role of large biopharmaceutical companies in the development and commercialization of new drugs approved by the U.S. Food and Drug Administration (FDA) between 2010 and 2020. It combines drug-level data on clinical development with firm-level data on ownership and collaborations to trace the sourcing trajectories of 371 novel drugs. We find that large biopharmaceutical companies were affiliated with 289 drugs, or 77% of the 371 FDA-approved drugs from 2010 to 2020. Notably, these companies produced 45 in-house (originated, developed, and marketed internally) drugs (12%) and, through collaborations and external sourcing, were able to secure partial or full ownership of a total of 228 drugs (61%). This is study is among the first to model the innovation nexus across distinct phases of the R&D and commercialization process and is systematically mapping firm involvement throughout the drug life cycle. The results confirm the existence of a fragmented innovation nexus and highlight various innovation trajectories for drugs ultimately marketed by large biopharmaceutical firms
Investigating the Impact of Alignment Angle Between Copper Turns and Magnetic Core on Magnetic Field Coupling in PCB Integrated Inductors
No full textInternational audienceThis study investigates the influence of copper trace alignment relative to the magnetic core in PCB-embedded inductors, focusing on the effects of the alignment angle on perpendicular magnetic flux density that shall cause eddy currents in AC applications. Although aligning traces at right angles is common in traditional inductor winding, it may not be feasible for PCB designs due to manufacturing constraints. The study proposes an investigation of the angular-shift effects on magnetic flux while maintaining practical PCB manufacturability in potential applications like static power converters. By evaluating how the angular shift impacts magnetic flux behavior in copper traces, this research is part of a study that aims to address efficiency losses and heating caused by eddy currents. Through Finite Element Method (FEM) simulations using Ansys Maxwell software and experimental validation, the results demonstrate that smaller alignment angles, particularly at 0°, reduce perpendicular flux what shall mitigate eddy current formation in AC applications, improving inductor performance
Design and Optimization of an Unbalanced-flux Transformer for 1 kW LLC Transformer
No full textInternational audienceExisting works to increase the power density of LLC transformer are mainly based on the MHz approach. This paper proposes a new LLC transformer design based on the recent introduced concept called the unbalanced-flux magnetics. The transformer was optimized using Genetic algorithm and iterative optimization approach. The unbalanced-flux transformer was designed and experimentally tested in 1 kW 400/48V LLC converter. The LLC converter is built, and the transformer is successfully up-to 750 W without heatsink and 1 kW with heatsink. The realized realizing power density is 224W/cm 3 which is approximately 3x higher than the results in the state-of-the-art
Effects of Removing Bottom-side Copper in Baseplate-less Power Modules
No full textInternational audiencePerformance of SiC MOSFETs are limited by the inherent parasitic elements originating from the packaging structure. In this paper, the parasitic capacitance of a 1.2 kV SiC MOSFET half-bridge power module is significantly reduced by removing the bottom-side copper, and the influence on its electrical and thermal performance is experimentally evaluated. Finally it is concluded that even though the modified module show significant advantages in turn-on switching energy, an increase in turn-off energy offsets it while also achieving a worse thermal performance
Comparative Loss Analysis of an Axial-Flux PMSM Fed by a Modular Multilevel Inverter (BM3) Versus a Two-level Inverter (SVPWM)
No full textInternational audienceLoss reduction of up to 11 % in an AFPM machines is achieved using a Modular Multilevel Converter, enhancing efficiency and extending the range of electric vehicles. Simulations highlight significant advantages in reducing THD by up to 16 %, contributing to increased sustainability and resource conservation in all sectors of electric vehicles
Performance Evaluation of Three-Phase, Two-Level Medium Voltage Power Stack Based on 10 kV SiC MOSFETs
No full textInternational audienceThe performance of a 50 kVA three-phase, two-level medium voltage power stack based on 10 kV SiC MOSFETs has been evaluated under varying load conditions, i.e. voltage-and current-levels, coolant temperatures, and switching frequencies. A calorimetric measurement method is applied to estimate the power stack losses and its equivalent power stack efficiency. Experimental results from an inductive load test setup show an equivalent power stack efficiency of 98.8% ± 0.56‰ at 6 kV DC-link voltage, 10 kHz switching frequency, and 40 • C coolant temperature with a maximum MOSFET junction temperature of less than 115 • C and thermal resistance of 0.38 K/W
Simple nine-level inverter with 10 switches and a floating capacitor
No full textInternational audienceThis paper presents a simple nine-level inverter with 10 switches and a floating capacitor. The proposed inverter consists of a five-level activeneutral-point-clamped (ANPC) leg and an unfolding leg. The ANPC leg generates a pulsating AC waveform with five voltage levels. The unfolding leg operates at the grid frequency and unfolds the pulsating AC waveform to convert it into a nine-level waveform. Also, a floating capacitor voltage balancing algorithm is introduced to ensure voltage stability. To show the feasibility and performance of the proposed inverter, 1.5 kW prototype is developed
Second Life Li-ion batteries: Influence of aging on the Techno-economic Analysis of a Microgrid
No full textInternational audienceIn the context of second life lithium-ion batteries, understanding the aging process is crucial for accurately sizing a microgrid that employs Energy Storage Systems. This article introduces a novel aging model that captures the aging knee point of lithium-ion batteries and integrates it in a microgrid simulation. The goal is to understand how key aging parameters influence battery performance within the microgrid. The study analyzes the impact of the aging knee, initial State of Health and retail price
Mission-Profile Based Reliability Framework for Medium-Frequency Transformers
No full textThis paper was presented at the EPE 2025 conference and was subsequently selected for publication in the special issue of Elsevier's PEDC journal. Therefore, only the abstract appears on the conference website.International audienceThis paper presents a theoretical framework for assessing the reliability of medium-frequency transformers by dividing their structure into dielectric regions and forecasting their lifetime based on mission profiles. The framework incorporates random failure and wear-out analysis to estimate reliability, highlighting specific failure mechanisms associated with high-frequency switching and insulation stresses. A case study of a 200 kW, 15 kHz dual active bridge converter is presented to demonstrate the proposed methodology. The derived lifetime distribution can support the design of the medium-frequency transformer and help evaluate the related risk of unreliability