Sergio Casu

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.

A polycarbonate RFID tag for blood chain tracking

In this paper we describe the design of a RFID tag in the UHF band, to be applied to the bags for the collection and transport of blood. RFID use allows to track the chain of transfusion blood from selection until the seals transfusion , thus helping to improve patient safety.

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.

Evaluation of the effects of UHF electromagnetic fields on a blood bag

In this paper we evaluate the effects of UHF electromagnetic fields (in different configurations) on a blood bag, to show that the effects are small enough to support the use of UHF RFID also in the blood transfusion supply chain.

Robustness of flexible 7T-MRI coil behaviour

In magnetic resonance imaging (MRI), the electrical performance of the RF coil is critical to achieve sufficient signal to noise ratio (SNR). In this work, the variation of performance of a plane and a flexible coil over a saline and a humanlike phantom is proposed. In order to evaluate the RF sensitivity of these flexible devices, we performed both an electrical characterization of the coil performances and a MRI simulation on a saline phantom.

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.

Analysis of superparamagnetic scaffolds: For bone tissue engineering in static magnetic and dynamic fields

Bone tissue engineering has obtained valuable results using biophysical stimulation through magnetic fields to enhance integration of prosthetic implants. Recently a new class of therapeutic scaffolds has been developed in order to activate remotely, in non-invasive way, using magnetic fields. In our work we analyzed the ability of these scaffolds to attract magnetic bioagents towards them, thanks to the magnetic field gradients due to the non-linear response of the prosthetic implant. The possibility of influence osteogenic and/or angiogenic cells is taken into account, and a simple chemotaxis model indirectly driven by magnetic field is proposed.