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2. Effectiveness of synthetic calcite doped with Fe-EDDHSA as a slow-release Fe source: In-vitro experiment on kiwifruit (Actinidia chinensis var. deliciosa) plants

Author

BALDI E., MARINO G., MUZZI E., MARZADORI C., CIAVATTA C., TAVONI M., Di GIOSIA M., CALVARESI M., FALINI G., ZERBETTO F., TOSELLI M., and BALDI E., MARINO G., MUZZI E., MARZADORI C., CIAVATTA C., TAVONI M., Di GIOSIA M., CALVARESI M., FALINI G., ZERBETTO F., TOSELLI M.

Subjects
in-vitro culture, Fe-chelates| in-vitro culture| pH| alkaline growing media| EDDHSA/CaCO3, pH, Fe-chelate, EDDHSA/CaCO3, alkaline growing media, lcsh:Agriculture (General), lcsh:S1-972
Abstract

Doped calcite (Fe-EDDHSA/CaCO3) was experimentally produced. The hypothesis of the present experiment is that, when roots get in contact with Fe-EDDHSA/CaCO3, the extrusion of H+ decreases the pH and dissolves calcite with subsequent release of Fe that becomes available for roots. The aim of the experiment was to determine whether doped calcite might represent a slow-release Fe source for in-vitro grown kiwifruit plantlets. The root elongation media used in the experiment had pH 8.0 and differed from each other for Fe supply as follow: Control medium that contained complete Murashige and Skoog salt mixture, including FeSO4 and Na2EDTA; calcite medium enriched with Fe-EDDHSA/CaCO3 as the only Fe source; −Fe medium without Fe. The absence of FeSO4 in the medium caused a reduction of plantlet growth. The final pH was higher with calcite medium than in control and −Fe. The addition of Fe-EDDHSA/CaCO3 increased Fe shoot concentration when compared with the −Fe medium. The data of the present experiment show the potential Fe slow release ability of Fe-EDDHSA/CaCO3; however, further investigation on Fe containing fertilizers should be conducted on potted plants to validate our results.

Published
2019
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22. Temperature and conductivity as indicators of the morphology and activity of a submarine volcano: Avyssos (nisyros) in the south aegean sea, Greece

Author

Bakalis, E. Mertzimekis, T.J. Nomikou, P. Zerbetto, F.

Abstract

The morphology and the activity of a submarine caldera, Avyssos, at the northern part of Nisyros volcano in the South Aegean Sea (Greece), has been studied by means of remotely-operated underwater vehicle dives. The recorded time series of temperature and conductivity over the submarine volcano have been analyzed in terms of the generalized moments method. The findings of the mathematical analysis shed light on the volcanic activity, but also on the morphology (shape) of the submarine volcano. The conductivity time series indicates that the volcano is at rest, in agreement with other types of observations. On the other hand, temperature fluctuations, which in general describe a multifractal process, show that the submarine caldera operates as an open system that interacts with its surroundings. This type of analysis can be used as an indicator for the state of activity and the morphological structure (closed or open system) of a submarine volcano. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2018

23. Multifractal structure of microscopic eye–head coordination

Author

Bakalis, E. Fujie, H. Zerbetto, F. Tanaka, Y.

Abstract

Fixational eye movements contribute to visual processing. The information encoded in them is crucial for signals coming from fovea since it connects visual information with brain activity. We recorded microsaccades and tiny head movements at high resolution, with a sampling rate of 300 Hz. Microsaccades are likely influenced by heads's motion. Multifractal analysis shows that both movements are multiplicative processes of different origins, thereby reflecting the presence of different strategies. Microsaccades draw steps from a broad distribution of probability values, which likely indicates the way that the eyes use to maximize information, and satisfies a stretched exponential distribution. On the other hand, tiny head movements are described well by a lognormal distribution. Both movements, eye and head, are initially correlated and de-coherence of the two takes place for times greater than 29.2 seconds. © 2018 Elsevier B.V.

Published
2018

34. Real-time Observation of Phonon-Mediated $\sigma$-$\pi$ Interband Scattering in MgB2

Author

Baldini E., Mann A., Benfatto L., Cappelluti E., Acocella A., Silkin V.M., Eremeev S.V., Kuzmenko A.B., Borroni S., Tan T., Xi X.X., Zerbetto F., Merlin R., and Carbone F.

Subjects
sInterband scattering, Light excitation, Layered material, Multi-band superconductors, Plasma frequencies, MgB2, Condensed Matter::Superconductivity, Condensed Matter - Superconductivity, Electronic subsystem, Real time observation, Transient controls
Abstract

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properties. Here we show that the population of E$_{2g}$ phonons in the multiband superconductor MgB$_2$ can be selectively enhanced by femtosecond laser pulses, leading to a transient control of the number of carriers in the {\sigma}-electronic subsystem. The nonequilibrium evolution of the material optical constants is followed in the spectral region sensitive to both the a- and c-axis plasma frequencies and modeled theoretically, revealing the details of the $\sigma$-$\pi$ interband scattering mechanism in MgB$_2$., Comment: 5 pages, 3 figures, 7 supplemental pages, 6 supplemental figures

Published
2017
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35. Breathing modes of Kolumbo submarine volcano (Santorini, Greece)

Author

Bakalis, E. Mertzimekis, T.J. Nomikou, P. Zerbetto, F.

Abstract

Submarine volcanoes, such as Kolumbo (Santorini, Greece) are natural laboratories for fostering multidisciplinary studies. Their investigation requires the most innovative marine technology together with advanced data analysis. Conductivity and temperature of seawater were recorded directly above Kolumbo's hydrothermal vent system. The respective time series have been analyzed in terms of non-equilibrium techniques. The energy dissipation of the volcanic activity is monitored by the temperature variations of seawater. The venting dynamics of chemical products is monitored by water conductivity. The analysis of the time series in terms of stochastic processes delivers scaling exponents with turning points between consecutive regimes for both conductivity and temperature. Changes of conductivity are shown to behave as a universal multifractal and their variance is subdiffusive as the scaling exponents indicate. Temperature is constant over volcanic rest periods and a universal multifractal behavior describes its changes in line with a subdiffusive character otherwise. The universal multifractal description illustrates the presence of non-conservative conductivity and temperature fields showing that the system never retains a real equilibrium state. The existence of a repeated pattern of the combined effect of both seawater and volcanic activity is predicted. The findings can shed light on the dynamics of chemical products emitted from the vents and point to the presence of underlying mechanisms that govern potentially hazardous, underwater volcanic environments. © 2017 The Author(s).

Published
2017

36. Excited and ionic states of formamide: An excited-state photoelectron spectroscopy and ab initio study.

Author

ter Steege, D. H. A., Lagrost, C., Buma, W. J., Leigh, D. A., and Zerbetto, F.

Subjects
FORMAMIDE, PHOTOELECTRON spectroscopy
Abstract

High-resolution excited-state photoelectron spectroscopy has been applied to unravel the spectroscopic and dynamic properties of the excited states of formamide populated by two- and three-photon excitation. In combination with ab initio calculations, this approach has led to various reassignments of previously observed states, and to the observation of new states. One of the aspects that particularly emerges from the present study is the important role of vibronic coupling, which leads to states of heavily mixed characten Projection on the ionic manifold -- as is done in our studies -- is, however, able to determine the various contributions of the wave function. Our studies have enabled us as well to resolve an apparent disagreement concerning the values of the ionization energies of the ground and first excited state of the radical cation. We find here adiabatic values of 10.233±0.008 and 10.725±0.020 eV, respectively. A final issue our studies shed light on concerns the vibrational properties of the ground state of the radical cation. [ABSTRACT FROM AUTHOR]

Published
2002
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44. Vibronic coupling in polyenes and their derivatives. Interpretation of the absorption and emission spectra of a derivative of dodecahexaene.

Author

Zerbetto, F., Zgierski, M. Z., Orlandi, G., and Marconi, G.

Subjects
*POLYENES, *COUPLINGS (Gearing), *FLUORESCENCE
Abstract

It is shown that unusual frequency differences of the totally symmetric C=C bond stretching vibration in the S1(2Ag) state between 2,12-dimethyltridecahexaene and two of its derivatives N-(2,4,6,8,10-dodecapentaenylidine) butylamine (12SB) and dodecapentaenal (12R), result from vibronic coupling between the S1(2Ag) and S2(1Bu) electronic states via totally symmetric vibrations in 12SB and 12R. The vibronic coupling matrix elements between the lower ππ* electronic states of the three molecules are evaluated by CNDO/S+CISD calculations in a floating atomic orbital basis set. The resulting adiabatic frequencies of the Franck–Condon active totally symmetric vibrations in the S0(1Ag) and S1(2Ag) electronic states are in good agreement with experiment. High-resolution fluorescence and fluorescence excitation spectra of 12SB are successfully interpreted in terms of the vibronic coupling between the S1(2Ag) and S2(1Bu) electronic states via the totally symmetric C=C and C–C bond stretching vibrations. The analysis of these spectra provides values of the displacement parameters for these vibrations in the S1(2Ag) and S2(1Bu) states. [ABSTRACT FROM AUTHOR]

Published
1987
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45. Surface enhanced SHG from macrocycle, catenane and rotaxane thin films

Author

Arfaoui, I., Bermudez, V., De Nadai, C., Jalkanen, J.-P., Kajzar, F., Leigh, D.A., Lubomska, M., Mendoza, S.M., Niziol, J., Rudolf, Petra, Zerbetto, F., Grote, JG, Kaino, T, Kajzar, F, and Surfaces and Thin Films

Subjects
Rotaxane, Chemistry, second harmonic generation, surface effects, Catenane, Second-harmonic generation, Nonlinear optics, Nanotechnology, Molecular physics, molecular motors, X-Ray photoelectron spectroscopy, ENERGY MINIMIZATION, rotaxanes, Electric field, catenanes, MOLECULAR-MECHANICS, Monolayer, BENZYLIC AMIDE, Surface second harmonic generation, Thin film
Abstract

Surface enhanced second harmonic generation experiments on supramolecules: macrocycles, catenanes and rotaxanes, monolayers and multilayers deposited by vacuum evaporation on silver layers are reported and described. The measurements show that the molecules are ordered in thin films. The highest order is observed in the case of macrocycles and the lowest in thin films of fumaramide [2] rotaxanes. Also a better ordering is observed in the case of monolayers. The observed second harmonic generation activity is interpreted in terms of electric field induced second harmonic generation. The electric field contributing to SHG signal is created by silver atoms on the surface of silver layers. The measured second order NLO susceptibilities for a fumaramide [2] rotaxane is compared with that obtained by considering only EFISH contribution to SHG intensities. The electric filed on the surface of silver layer is calculated using TINKER molecular mechanics/dynamics software and the Embedded Atom model. An excellent agreement is observed between the calculated and the measured SHG susceptibilities.

Published
2005
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46. Isomers of C70 dimer

Author

Heine, T., Zerbetto, F., Seifert, G., and Fowler, P. W.

Subjects
Ring formation (Chemistry) -- Research, Raman spectroscopy -- Research, Isomerism -- Electric properties, Chemicals, plastics and rubber industries
Abstract

The calculated binding energies and spectroscopic properties of C70 dimers are presented. The two most stable isomers of the set of conceivable [2 + 2] cycloaddition products are isoenergetic, and both are compatible with NMR, infrared, and Raman data on the product synthesized by Lebedkin et al.

Published
2001

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