| 1. |
- Panarese, A., et al.
(author)
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Molecular dynamics calculation of the spectral densities of plasma fluctuations
- 2018
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In: Journal of Plasma Physics. - : CAMBRIDGE UNIV PRESS. - 0022-3778 .- 1469-7807. ; 84:3
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Journal article (peer-reviewed)abstract
- Spectral densities of plasma fluctuations are calculated for the thermal case using classical molecular dynamics (MD) assuming Coulomb interactions and a short-range cutoff radius. The aim of the calculation is to verify limits and performances of such calculations in the light of possible generalizations, e.g. collisional or non-ideal plasmas. Results are presented for ideal, collisionless, fully ionized thermal plasmas. Comparison with the analytical theory reveals a generally satisfactory agreement with possibility for improvement when more strict numerical parameters are used albeit with a strong increase in computational cost. The largest deviations have been observed in the vicinity of the weakly damped eigenmodes. The agreement is strong in other parts of the spectrum, where Landau damping is prominent, and overcomes the effects stemming from the excess collisionality and coupling as well as from the exclusion of short-range collisions.
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| 2. |
- Rocculi, P., et al.
(author)
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The potential role of isothermal calorimetry in studies of the stability of fresh-cut fruits
- 2012
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In: LWT - Food Science and Technology. - : Elsevier BV. - 0023-6438. ; 49:2, s. 320-323
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Journal article (peer-reviewed)abstract
- Attention is drawn to the feasibility of using high sensitivity isothermal heat conduction calorimetry to study metabolic responses of differently processed and stored fresh-cut fruit. The heat production of endogenous (tissue metabolism during 12 h of analysis at 10 degrees C for kiwifruit and strawberry) and exogenous (microbial growth during 18 d of analysis at 10 degrees C for cantaloupe) biological processes was investigated. Osmotic dehydration of fresh kiwifruit in sucrose solution (61.5 g/L) at different treatment times (30, 60 and 180 min), resulted in metabolic heat production decrease, confirming the progressive cell death induced by osmotic dehydration. Analysis on strawberry slices under two atmospheric conditions (air and innovative modified atmosphere) seemed to confirm the inhibitory effect of N2O on metabolic activity. Cantaloupe samples immersed in three different syrups (SS: sucrose syrup (20 degrees Brix); SS1: SS + 0.5 g/L ascorbic acid + 0.5 g/L citric acid; SS2: SS1 + 0.1 g/L potassium sorbate) showed a stability increase when additives with antimicrobial properties were included. Our findings confirm that isothermal calorimetry provides a versatile and high sensitive tool for conducting fundamental metabolic studies on the effect of different processing operations on the quality and shelf life of fresh-cut fruit and vegetables. (C) 2012 Elsevier Ltd. All rights reserved.
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