Microwave drying in fluidized bed to dehydrate microencapsulated Saccharomyces cerevisiae cells. Temperature control strategies

[EN] Alginate microcapsules containing cell yeasts of the species Saccharomyces cerivisae, used as a reference microorganism, were studied here to improve the protection of cell activity during food processing. Here a novel drying process was proposed to optimize processing conditions. The dehydration of microcapsules by microwaves and under near fluidizing conditions (NFMD), allows performing dehydration employing lower temperatures to maintain high viability levels and a high quality end product. Thus, strategies based on the combination of different thermal gradients and processing temperatures were analysed through a series of NFMD experiments.Mardaras, J.; Lombraña, JI.; Villarán, MC. (2018). Microwave drying in fluidized bed to dehydrate microencapsulated Saccharomyces cerevisiae cells. Temperature control strategies. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1895-1902. https://doi.org/10.4995/IDS2018.2018.7854OCS1895190

MadQCI: a heterogeneous and scalable SDN QKD network deployed in production facilities

Current quantum key distribution (QKD) networks focus almost exclusively on transporting secret keys with the highest possible rate. Consequently, they are built as mostly fixed, ad hoc, logically, and physically isolated infrastructures designed to avoid any penalty to the quantum channel. This architecture is neither scalable nor cost-effective and future, real-world deployments will differ considerably. The structure of the MadQCI QKD network presented here is based on disaggregated components and modern paradigms especially designed for flexibility, upgradability, and facilitating the integration of QKD in the security and telecommunications-networks ecosystem. These underlying ideas have been tested by deploying many QKD systems from several manufacturers in a real-world, multi-tenant telecommunications network, installed in production facilities and sharing the infrastructure with commercial traffic. Different technologies have been used in different links to address the variety of situations and needs that arise in real networks, exploring a wide range of possibilities. Finally, a set of realistic use cases have been implemented to demonstrate the validity and performance of the network. The testing took place during a period close to three years, where most of the nodes were continuously active

Analysis of operating strategies in the production of special foods in vials by freeze drying

A finite element model (FEM) with axial symmetry conditions and isoparametric elements was applied to the freeze drying of special foods in vials. The model was verified by experiments using a methyl cellulose test material. The model was used to simulate and evaluate various heating strategies in freeze drying in order to reduce drying cycles and increase process efficiency. The effect of sublimation front temperature and freeze drying periods on the process duration was analysed.This work was part of a research project sup-ported by CICYT on drying of products at lowtemperature developed during 1991–1994 withinthe field of Food Technology.Peer Reviewe

Simulation and design of beating profiles in beat controlled freeze-drying or pharmaceuticals in vials by the application of a sublimation cylindrical model

A finite element method (FEM) with axial symmetry conditions and isoparametric elements has been applied to describe the freeze drying of a certain pharmaceutical contained in vials in industrial like conditions. Several operating strategies vere proved on the basis of considering three different stages during freeze-drying in relation with the modification of heating and product temperature evolutions. The model offers interesting perspectives to find the most adequate combination of operating conditions in order to reduce drying time.Peer reviewe

Kinetic and quality study of mushroom drying under microwave and vacuum

The aim of this work is to model the drying kinetics of mushrooms under several operational conditions, to evaluate the effective diffusivity coefficient of moisture removing by a drying model and inverse calculus method in finite differences and to study the effect on the final quality of dehydrated mushrooms. Different ways of microwave vacuum drying were compared to freeze-drying. Results show that a decrement of the applied pressure produces a certain increase in the drying rate together with a lower moisture in the dehydrated product at the end. Temperature control inside the sample helps to ensure a better quality in the dehydrated product, than when controlled at the surface. Diffusivity coefficients show a correspondence with product temperature during drying. The microwave dried samples obtained with moderate power and temperature control of product shown an important degree of quality similar to that obtained by freeze-drying. Copyright © 2005 Taylor & Francis, Inc.Peer Reviewe

Drying kinetics and energy consumption in vacuum drying process with microwave and radiant heating

The general objective of this work is to analyze energy input in a vacuum process with the incorporation of microwave heating. Thus, necessary criteria for designing an efficient freeze-drying operation are considered through the analysis of strategies based on the combination of different intensities of radiant and microwave heating. The other aim of this research topic is to study the kinetics of drying in relation to mass transfer parameters. Five freeze-drying strategies using both heating systems were used. Consequently, energy input could be related to diffusivity coefficients, temperature and pressure profiles during dehydration of the product and analyzed in comparison to a conventional freeze-drying process.Peer Reviewe