scholarly journals ANALYSIS AND OPTIMIZATION OF PULSED ELECTRIC FIELD DISTRIBUTION EFFICIENCY IN A CYLINDRICAL TREATMENT CHAMBER FOR JUICE EXTRACTION

Electroporation is an effective phenomenon of inactivating viable pathogens present in the liquid food for pulsed electric field (PEF) applications. It is a technique which depends on applied electric field strength for causing pores on cell plasma membrane. The various parameters which affect the electroporation efficacy are, the electric field intensity, pulse width, number of pulses, pulse interval and the electrode. The electrode provides a contact between the high voltage pulse generator and the liquid food, and it plays an important role in getting the required inactivation outcome. The electric field distribution varies based on electrode designs. Parallel plate electrodes are generally used due to the uniform electric field it delivers in the inactivation area, where high possibility of microbial inactivation will occur. This paper analyses the effectiveness of round edged parallel plate electrodes immersed in water which provides uniform electric field distribution in the inactivation area. Analyses have been performed on electric field distribution through four kinds of materials such as glass, alumina, quartz and plexiglass, which contains these electrodes in the center filled with sterile water. The electrodes are circular, and edge smoothened and hence the field distribution is also analyzed on electrode edges. The distance between the electrodes including the surface material is kept at 5 mm. The diameter of the electrodes are 40 mm and the electric field simulations are implemented in ANSYS MAXWELL v 15.0. Based on results it is reported that alumina required less peak voltage for generating 20 kV/cm field strength (nominal field required for bacterial inactivation) when compared with other materials. Also alumina exhibited less reduction of field travelling through it, and resulted in 82% of field application in the inactivation area which is comparatively higher than other materials. The results indicate that alumina is highly recommended for future noninvasive pulsed electric field applications.


2017 ◽  
Vol 5 (3) ◽  
pp. 96
Author(s):  
I. Made Yulistya Negara ◽  
Dimas Anton Asfani ◽  
Daniar Fahmi ◽  
Yusrizal Afif

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.


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