Francesco Desogus

Evaluation of a microwave resonant cavity as a reactor for enzyme reactions

We present here the design and analysis of a microwave resonant cavity to evaluate the effect of RF electromagnetic field on enzyme reactions. The cavity has been first designed using CST Microwave Studio. Then, its behaviour in the actual use has been evaluated using the COMSOL multiphysics. The presented results show that such cavity can be quite effective.

Microwave resonant cavity as a reactor for the enzymatic hydrolysis of sucrose

We present here the design and analysis of a microwave resonant cavity to evaluate the effect of RF electromagnetic field on enzyme reactions. The cavity has been first designed using CST. Then, its behaviour in the actual use has been evaluated using the COMSOL multiphysics.

Design and Simulation of a Rf Resonant Reactor for Biochemical Reactions

In this work the development of a multi-tube reactor for chemical processing, running in a microwave irradiated field, is presented. Considering the need of operating with well-known and reproducible experimental conditions, the aim was to design a resonant cavity inside which the tubes with the fluid to be processed are positioned. The irradiated fluid is exposed to constant microwave power since the system works in resonance conditions, therefore the field intensity and power absorption can be accurately calculated and mapped. The cavity was designed by the authors using proper commercial software for 3D electromagnetic simulation, and then the reactor operation was tested by another commercial multiphysics simulation software. The results here presented show the proper geometrical characteristics of the cavity and of the internal tubes to work at 2.45 GHz of frequency while the irradiation power can be varied depending on the needs of the process. The reactor can work with different homogeneous systems, both chemical and biological (enzyme reactions). The future development will be the construction and the real operation of the designed apparatus in order to confirm the simulation results.

Microwaves disinfection of farmland

Abstract This work focuses on the heat transfer dynamics in agricultural soils when exposed to microwave fields, in order to disinfect them and to eliminate dangerous organisms without using pesticides. The work manages with the use of a horn antenna to irradiate the superficial layer of soils and so to eliminate harmful bio-agents within a fixed depth. The soil was approximated using a transmission line model. Considering the dielectric constant of the ground as a function of the soil water content, it was possible to evaluate the power absorbed by the irradiated ground and the temperature increase and its profile depending on the irradiation time. Since the latter information is strictly connected to the heat transfer process occurring in the system, we demonstrated the feasibility of the methodology here proposed to achieve difficult conditions for microbial and pathogens life, leading to an effective disinfection of the treated farmland.

Use of Microwaves for Disinfection of Farmland: a Feasibility Study

This work focuses on the heat transfer dynamics in agricultural soils when exposed to microwave (MW) fields, in order to disinfect them and to eliminate dangerous organisms without using pesticides. The work managed with the design of a horn antenna, with fixed feeding power, to be used to irradiate the superficial layer of soils for a fixed depth. The soil was approximated with a transmission line model, i.e. a lumped electrical model. By this model, after evaluating the relevant physical parameters such as the dielectric constant (as a function of the soil water content), it was possible to evaluate the power absorption and, finally, the increase in temperature and its profile as a function of the irradiation time. The latter information, strictly connected to the heat transfer process, demonstrated the feasibility of the methodology here proposed to achieve difficult conditions for microbial and pathogens life and so an effective disinfection of the treated farmland.

Nonlinear Analysis of Soil Microwave Heating: Application to Agricultural Soils Disinfection

Agriculture is facing the challenge of increasing the quality of food production with environmentally friendly and health compatible processes featuring limited use of chemicals. The elimination of pathogens and harmful biological agents still remains a fundamental requirement. Therefore, soil physical disinfestation and disinfection represent a promising approach to a sustainable and profitable agriculture. For this reason, a cheap and selective method based on microwave power is proposed. Microwave soil disinfection is based on increasing the soil and, consequently, the pathogens temperature, by radiating the system with microwaves and maintaining the temperature over a threshold value for a sufficient time. This work deals with the nonlinear modeling of electromagnetic and heating phenomena involved in the soil disinfection. Thus, the feasibility of the proposed approach is demonstrated in a realistic case and an optimal design process is derived for any kind of soil.

Microwave Effects on the Enzymatic Hydrolysis of Sucrose

This work focuses on the experimental study about the influence of microwave radiation (at 2.45 GHz of frequency) on the enzyme catalyzed hydrolysis of sucrose in aqueous solutions, in order to detect possible modifications in the whole reaction rate, and to identify the inhibition effect due to sucrose and/or to the hydrolysis product D-fructose. For comparison purposes, the same experimental conditions were applied both in the presence and in the absence of irradiation. The experimental concentrations were estimated from spectrophotometer acquisitions in the UV wavelengths, and data were fitted with proper kinetic models, taking into account the main reaction pathway and inhibition phenomena. The obtained results show a modification in the reaction kinetics due to the microwave application.

A feasibility study for disinfection of farmland using microwaves

This work focuses on the heat transfer dynamics in agricultural soils when exposed to microwave (MW) fields, in order to disinfect them and to eliminate dangerous organisms without using pesticides. The work managed with the design of a horn antenna, with fixed feeding power, to be used to irradiate the superficial layer of soils for a fixed depth. The soil was approximated using a transmission line model, i.e. a lumped electrical model. By this model, after having evaluated the relevant physical parameters, e.g. the dielectric constant (as a function of the soil water content), it was possible to evaluate the power absorption for the irradiated ground and, finally, the increase in temperature and its profile as a function of the irradiation time. Since the latter information is strictly connected to the heat transfer process occurring in the system, it is demonstrated the feasibility of the methodology here proposed to achieve difficult conditions for microbial and pathogens life and so an effective disinfection of the treated farmland.