What was studied? This report studies the possibilities and challenges of establishing a high-power charging system for battery-electric aircraft (EA) within an operational airport environment, with a particular focus on enabling short turnaround times (TAT). The study integrates perspectives from a diverse group of stakeholders, including an airport owner, a charging equipment solution provider, an aircraft developer, a research institute, an innovation arena, and a testbed operator. The aim is to significantly enhance the common understanding and identify viable pathways for the efficient and safe implementation of EA charging systems. The report addresses the three key subsystems (airport, charging equipment, and aircraft) detailing their specific requirements, including e.g. technical, operational, regulatory, and safety considerations, followed by identification and evaluation of possible power system topologies and conceptual charging solutions. Smart control of EA charging systems is explored and modeled to support adequate system design and optimal utilization of available power capacity. Additionally, the report presents measurement results from an operational airport to better understand the current electromagnetic compatibility (EMC) environment. It also includes a review of aviation cybersecurity and offers initial recommendations for future risk assessments to ensure an efficient and safe deployment of EA charging systems.
The drying process is largely used in many different industrial applications, such as treatment of foods, production of cosmetics and pharmaceuticals, manufacturing of paper, wood and building materials, polymers and so on. Physical and mathematical models can constitute useful tools to establish the influence of the main process variables on the final product quality, in order to apply an effective production control. In this work, simulation model was developed to describe combined convective/microwave assisted drying. In particular, a multi-physics approach was applied to take into account heat and two mass balances (for liquid water and for water vapor) and Maxwell's equations to describe electromagnetic field propagation. Potato matrix was selected as food material; a waveguide with a rectangular cross section, equipped with a hot air circulator device, was used as microwave applicator. The proposed model was found able to describe the process, being thus a useful tool for design and management of the process itself.
This study aimed to devise innovative, tailor-made, appealing, tasty and semi-industrialized dishes, using sustainable and under-utilized seafood species (bib, common dab, common carp, blue mussel and blue whiting), that can meet the specific nutritional and functional needs of children (8-10-years), pregnant women (20-40-years) and seniors (≥60-years). Hence, contests were organised among cooking schools from 6 European countries and the best recipes/dishes were reformulated, semi-industrially produced and chemically and microbiologically evaluated. The dishes intended for: (i) children and pregnant women had EPA + DHA and I levels that reached the target quantities, supporting the claim as “high in I”; and (ii) seniors were “high in protein” (24.8%-Soup_S and 34.0%-Balls_S of the energy was provided by proteins), “high in vitamin B12”, and had Na contents (≤0.4%) below the defined limit. All dishes reached the vitamin D target value. Sausages_C, Roulade_P, Fillet_P and Balls_S had a well-balanced protein/fat ratio. Roulade_P presented the highest n-3 PUFA/n-6 PUFA ratio (3.3), while Sausages_C the lowest SFA/UNS ratio (0.2). Dishes were considered safe based on different parameters (e.g. Hg-T, PBDEs, Escherichia coli). All represent dietary sources contributing to meet the reference intakes of target nutrients (33->100%), providing valuable options to overcome nutritional and functional imbalances of the three groups.
In this chapter, an introduction to microwave heating of foods and some commonly encountered phenomena in heating uniformity is given. The chapter is intended to help the reader make initial progress and to serve as a beginning for deeper understanding of microwave heating, hopefully resulting in improved heating results and well-designed products. The impact of dielectric properties as well as geometrical properties on the resulting heating is introduced.
A pilot-scale process for continuous in-flow microwave processing of particulate pumpable foods, designed and implemented at RISE Research Institute of Sweden [1], was studied for heat treatment of a particulate, viscous model food at high temperature conditions at 2450 MHz. In this paper, the technology will be discussed as an alternative high-temperature short-time (HTST) processing method for a high-concentrated particulate model product. The technology combines TM 020 and TM 120 microwave mode heating. The rapidness in heating the product will be illustrated for selected time-temperature conditions after tubular microwave heating. The latter corresponds to the required microbiological inactivation, for a product intended for storage at ambient conditions or cool storage, respectively. As will be exemplified, the microwave HTST system studied results in large process flexibility. Additionally, it offers advantages in product quality.
A pilot-scale process for continuous in-flow microwave processing of particulate pumpable foods, designed and implemented at RISE Agrifood and Bioscience, was evaluated for heat treatment of a particulate, viscous model food at high-temperature conditions at 2450 MHz. The microwave system has three consecutive cavities, one excited by the TM020 microwave mode that heats primarily in the centre of the tube, and two cavities fed by TM120 modes that heat primarily in the tube periphery. In this paper, combined TM020 and TM120 tubular microwave heating is evaluated as an alternative to high-temperature short-time (HTST) processing for a high-concentrated particulate model product. Rapidness in heating of the product was evaluated after tubular microwave heating for different time-temperature conditions, corresponding to the required microbiological inactivation for a model product intended for storage at ambient conditions. Moreover, the effects on product quality of the microwave heated model soup were investigated in terms of texture, piece integrity and colour. Microstructural analysis was used to gain an understanding of the effects of heating at a microscopic scale. It was found that the microwave-assisted HTST system results in large process flexibility. Additionally, it offers advantages in product quality in terms of piece integrity and texture.
There are several advantages of industrial microwave-infrared baking of bread. Among these are: shorter process time, reduced energy consumption, less space requirement of baking equipment in the production facility and increased flexibility in production. Furthermore, the fast and efficient energy transfer due to volumetric microwave heating during baking, and due to infrared colouring of the bread, also means considerably reduced need for pre-heating, with resulting cost and time benefits. However, results are promising also when it comes to quality aspects. In this paper, this will be exemplified for two types of bread, which are microwave baked in a continuous pilot-scale oven and then coloured in a next pilot-scale oven section by infrared waves and/or convection. The resulting bread quality is presented in terms of colour and porosity for white tin loaves, and in terms of colour for rolls with seeds. The results are compared to the corresponding quality for conventionally baked bread. The comparison shows good agreement in quality between microwave-combination baked breads and conventionally baked breads. The results are promising also in terms of advantages for the bakery industry, from energy consumption, process time and flexibility aspects. The paper also presents electromagnetic modelling results for microwave baking of tin loaves. The latter results were valuable for the understanding of more uniform microwave baking.
A pilot-scale process for continuous in-flow microwave heating of pumpable foods was designed, built and evaluated for heat treatment of high-concentrated particulate foods at temperatures up to 135°C and at the microwave frequency 2450 MHz. In this work, the temperature uniformity of a particulate model soup after microwave heating is evaluated for selected goal temperatures and holding times, and the heating up time to goal temperature is investigated. Furthermore, choice of radial dimensions of the tube is discussed, as well as strategies for achieving an improved microwave heating uniformity of the product, based on calculated radial temperature profile and electromagnetic field distribution.
A pilot-scale process for continuous in-flow microwave processing of foods, designed and implemented at SP Food and Bioscience, was evaluated for heat treatment of a homogeneous model food for high-temperature short-time (HTST) conditions, at constant total input microwave power, at 2450 MHz. The microwave system has three consecutive cavities, one excited by the TM020 microwave mode that heats primarily in the tube centre, and two TM120 mode cavities that heat primarily in the tube periphery. The temperature uniformity of the homogeneous model food after microwave heating is here evaluated in terms of spatial distribution, for different set-ups of input microwave power in each cavity and for different order of the placement of the cavities, while maintaining the total input microwave power. The microwave heating uniformity is evaluated, based on measured and calculated radial temperature profiles. Combined TM020 and TM120 heating was found to result in more uniform heating by means of spatial temperature uniformity over the tube cross section. Furthermore, appropriately selected microwave power distribution between the centre and periphery heating cavities results in a stable heating profile in the studied food, that differs only about 10 °C or less between highest and lowest average values directly after microwave heating.
A critical analysis is made of literature reports on the dielectric properties of pure water from liquid water supercooled at -20 °C, to +100 °C, in principle in the frequency range 0 to 3 GHz. Measurements using complete multi-step numerical modelling of a dual resonant cavity at about 920 MHz and 2230 MHz are presented. The measured data at about +20 °C are used as reference for the calculation of data at other temperatures. Due to the high resolution and considerations of various error sources, the resulting accuracy becomes high and allows the construction of improved empirical formulae for the Debye relaxation behaviour. © 2007 IOP Publishing Ltd.
A new concept has been developed for characterizing the real-time evolution of the three-dimensional pore and lamella microstructure of bread during baking using synchrotron X-ray microtomography (SRµCT). A commercial, combined microwave-convective oven was modified and installed at the TOMCAT synchrotron tomography beamline at the Swiss Light Source (SLS), to capture the 3D dough-to-bread structural development in-situ at the micrometer scale with an acquisition time of 400 ms. This allowed characterization and quantitative comparison of three baking technologies: (1) convective heating, (2) microwave heating, and (3) a combination of convective and microwave heating. A workflow for automatic batchwise image processing and analysis of 3D bread structures (1530 analyzed volumes in total) was established for porosity, individual pore volume, elongation, coordination number and local wall thickness, which allowed for evaluation of the impact of baking technology on the bread structure evolution. The results showed that the porosity, mean pore volume and mean coordination number increase with time and that the mean local cell wall thickness decreases with time. Small and more isolated pores are connecting with larger and already more connected pores as function of time. Clear dependencies are established during the whole baking process between the mean pore volume and porosity, and between the mean local wall thickness and the mean coordination number. This technique opens new opportunities for understanding the mechanisms governing the structural changes during baking and discern the parameters controlling the final bread quality. © 2023 The Author(s)