Search

Your search keyword '"Barraco, D."' showing total 145 results
Start Over Author "Barraco, D."
145 results on '"Barraco, D."'

5. Relativistic dynamics of cylindrical shells of counter-rotating particles

Author

Hamity, V. H., Cecere, M. A., and Barraco, D. E.

Subjects
General Relativity and Quantum Cosmology
Abstract

Although infinite cylinders are not astrophysical entities, it is possible to learn a great deal about the basic qualitative features of generation of gravitational waves and the behavior of the matter conforming such shells in the limits of very small radius. We describe the analytical model using kinetic theory for the matter and the junction conditions through the shell to obtain its equation of motion. The nature of the static solutions are analyzed, both for a single shell as well as for two concentric shells. In this second case, for a time dependent external shell, we integrate numerically the equation of motion for several values of the constants of the system. Also, a brief description in terms of the Komar mass is given to account for the gravitational wave energy emitted by the system., Comment: 19 pages, 8 figures

Published
2007
Full Text
View/download PDF

6. Equilibrium hydrostatic equation and Newtonian limit of the singular f(R) gravity

Author

Bustelo, A. J. and Barraco, D. E.

Subjects
General Relativity and Quantum Cosmology, Astrophysics, High Energy Physics - Theory
Abstract

We derive the equilibrium hydrostatic equation of a spherical star for any gravitational Lagrangian density of the form $L=\sqrt{-g}f(R)$. The Palatini variational principle for the Helmholtz Lagrangian in the Einstein gauge is used to obtain the field equations in this gauge. The equilibrium hydrostatic equation is obtained and is used to study the Newtonian limit for $f(R)=R-\frac{a^{2}}{3R}$. The same procedure is carried out for the more generally case $f(R)=R-\frac{1}{n+2}\frac{a^{n+1}}{R^{n}}$ giving a good Newtonian limit., Comment: Revised version, to appear in Classical and Quantum Gravity.

Published
2006
Full Text
View/download PDF

7. Newtonian limit of the singular f(R) gravity in the Palatini formalism

Author

Dominguez, A. E. and Barraco, D. E.

Subjects
General Relativity and Quantum Cosmology, Astrophysics, High Energy Physics - Theory
Abstract

Recently D. Vollick [Phys. Rev. D68, 063510 (2003)] has shown that the inclusion of the 1/R curvature terms in the gravitational action and the use of the Palatini formalism offer an alternative explanation for cosmological acceleration. In this work we show not only that this model of Vollick does not have a good Newtonian limit, but also that any f(R) theory with a pole of order n in R=0 and its second derivative respect to R evaluated at Ro is not zero, where Ro is the scalar curvature of background, does not have a good Newtonian limit., Comment: 9 pages

Published
2004
Full Text
View/download PDF

10. Biobased supramolecular ionic networks with optimized crystallinity and mechanical properties as promising dynamic materials for eutectogels design

Author

Química aplicada, Kimika aplikatua, Ronco, Ludmila Irene, Luque, Gisela C., Calderón, C. A., Euti, E. M., Rufeil Fiori, E., Barraco, D. E., Leiva, E. P. M., Mecerreyes Molero, David, Minari, Roque Javier, Picchio, Matías L., Química aplicada, Kimika aplikatua, Ronco, Ludmila Irene, Luque, Gisela C., Calderón, C. A., Euti, E. M., Rufeil Fiori, E., Barraco, D. E., Leiva, E. P. M., Mecerreyes Molero, David, Minari, Roque Javier, and Picchio, Matías L.

Abstract

Ionic supramolecular networks are attractive materials for technological applications with unique properties such as ionic conductivity, stimuli-responsiveness, recyclability, and self-healing. Herein, new semicrystalline supramolecular ionic networks are designed from fully biobased building blocks such as tartaric acid, phytic acid, sebacic acid, and a fatty dimer diamine (Priamine™ 1071). The combination of tartaric acid with Priamine™ 1071 results in a crystalline and brittle polymer, but its molecular regularity can be controlled by incorporating sebacic acid or phytic acid, affording tough materials with appropriate mechanical properties (elastic moduli ranging 19–42 MPa). Furthermore, the ionic polymers show network-to-liquid phase transitions between 75 and 127 °C, and in the liquid state, they were found to be miscible with a lithium-based deep eutectic solvent, yielding flexible and conductive eutectogels. Altogether, these dynamic networks could open new prospects for developing fully green soft ionic materials from their combination with other innovative and low-cost eutectic mixtures.

Published
2023

15. Composite solid electrolytes toward safer Lithium-metal cells

Author

JULIA GINETTE NICOLE AMICI, Calderón, C. A., Daniele Versaci, Dessantis, D., Marchisio, A., Colombo, R., Fagiolari, L., Mangini, A., Maria Laura Para, Siccardi, S., Alidoost, M., Di Prima, P., Luque, G., Barraco, D., Leiva, E., Federico Bella, Carlotta Francia, and Silvia Bodoardo

Subjects
Energy storage, Lithium-metal battery, Composite, Polymer electrolyte, Safety
Published
2021

18. Impact of bone marrow fibrosis grade in post-polycythemia vera and post-essential thrombocythemia myelofibrosis: A study of the MYSEC group

Author

Mora, B., Guglielmelli, P., Rumi, E., Maffioli, M., Barraco, D., Rambaldi, A., Caramella, M., Komrokji, R. S., Kiladjian, J. -J., Gotlib, J., Iurlo, A., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Albano, F., Benevolo, G., Cavalloni, C., Uccella, S., Accetta, R., Siracusa, C., Agnoli, S., Merli, M., Barbui, T., Bertu, L., Cazzola, M., Vannucchi, A. M., Passamonti, F., De Stefano V. (ORCID:0000-0002-5178-5827), Mora, B., Guglielmelli, P., Rumi, E., Maffioli, M., Barraco, D., Rambaldi, A., Caramella, M., Komrokji, R. S., Kiladjian, J. -J., Gotlib, J., Iurlo, A., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Albano, F., Benevolo, G., Cavalloni, C., Uccella, S., Accetta, R., Siracusa, C., Agnoli, S., Merli, M., Barbui, T., Bertu, L., Cazzola, M., Vannucchi, A. M., Passamonti, F., and De Stefano V. (ORCID:0000-0002-5178-5827)

Abstract

N/A

Published
2020

23. Second primary malignancies in postpolycythemia vera and postessential thrombocythemia myelofibrosis: A study on 2233 patients

Author

Mora, B., Rumi, E., Guglielmelli, P., Barraco, D., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Pietra, D., Barbui, T., Rotunno, G., Cazzola, M., Vannucchi, A. M., Giorgino, T., Passamonti, F., De Stefano V. (ORCID:0000-0002-5178-5827), Mora, B., Rumi, E., Guglielmelli, P., Barraco, D., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Pietra, D., Barbui, T., Rotunno, G., Cazzola, M., Vannucchi, A. M., Giorgino, T., Passamonti, F., and De Stefano V. (ORCID:0000-0002-5178-5827)

Abstract

Patients with myeloproliferative neoplasms (MPN) are known to have higher incidence of nonhematological second primary malignancies (SPM) compared to general population. In the MYSEC study on 781 secondary myelofibrosis (SMF) patients, the incidence of SPM after SMF diagnosis resulted 0.98/100 patient-years. When including non-melanoma skin cancers (NMSC), the incidence arose to 1.56/100 patientyears. In SMF, JAK inhibitor treatment was associated only with NMSC occurrence. Then, we merged the MYSEC cohort with a large dataset of PV and ET not evolving into SMF. In this subanalysis, we did not find any correlation between SPM and SMF occurrence. These findings highlight the need of studies aimed at identifying MPN patients at higher risk of SPM.

Published
2019

27. PS1458 RISK FACTORS AND OUTCOME OF ACUTE MYELOID LEUKEMIA SECONDARY TO POST-POLYCYTHEMIA VERA AND POST-ESSENTIAL THROMBOCYTHEMIA MYELOFIBROSIS: AN ANALYSIS OF THE MYSEC COHORT

Author

Mora, B., primary, Guglielmelli, P., additional, Rumi, E., additional, Maffioli, M., additional, Barraco, D., additional, Rambaldi, A., additional, Caramella, M., additional, Komrokji, R., additional, Kiladjian, J.J., additional, Gotlib, J., additional, Iurlo, A., additional, Cervantes, F., additional, Devos, T., additional, Palandri, F., additional, De Stefano, V., additional, Ruggeri, M., additional, Silver, R.T., additional, Benevolo, G., additional, Albano, F., additional, Cavalloni, C., additional, Pietra, D., additional, Barbui, T., additional, Rotunno, G., additional, Bertù, L., additional, Cazzola, M., additional, Vannucchi, A.M., additional, and Passamonti, F., additional

Published
2019
Full Text
View/download PDF

28. PS1462 SECOND PRIMARY MALIGNANCIES IN MYELOFIBROSIS PATIENTS TREATED WITH RUXOLITINIB: REAL WORLD EVIDENCE FROM 215 CONSECUTIVELY TREATED PATIENTS IN LOMBARDY

Author

Maffioli, M., primary, Giorgino, T., additional, Mora, B., additional, Iurlo, A., additional, Elli, E., additional, Finazzi, M.C., additional, Caramella, M., additional, Rumi, E., additional, Carraro, M.C., additional, Polverelli, N., additional, D’Adda, M., additional, Malato, S., additional, Rossi, M., additional, Molteni, A., additional, Vismara, A., additional, Sissa, C., additional, Spina, F., additional, Anghilieri, M., additional, Barraco, D., additional, Porta, M.G. Della, additional, and Passamonti, F., additional

Published
2019
Full Text
View/download PDF

29. Gender effect on phenotype and genotype in patients with post-polycythemia vera and post-essential thrombocythemia myelofibrosis: results from the MYSEC project

Author

Barraco, D., Mora, B., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, V., Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Merli, M., Pietra, D., Barbui, T., Rotunno, G., Cazzola, M., Giorgino, T., Vannucchi, A. M., Passamonti, F., De Stefano V. (ORCID:0000-0002-5178-5827), Barraco, D., Mora, B., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, V., Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Merli, M., Pietra, D., Barbui, T., Rotunno, G., Cazzola, M., Giorgino, T., Vannucchi, A. M., Passamonti, F., and De Stefano V. (ORCID:0000-0002-5178-5827)

Abstract

N/A

Published
2018

30. Value of cytogenetic abnormalities in post-polycythemia vera and post-essential thrombocythemia myelofibrosis: A study of the MYSEC project

Author

Mora, B., Giorgino, T., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Barraco, D., Merli, M., Pietra, D., Casalone, R., Barbui, T., Rotunno, G., Cazzola, M., Vannucchi, A. M., Passamonti, F., De Stefano V. (ORCID:0000-0002-5178-5827), Mora, B., Giorgino, T., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Barraco, D., Merli, M., Pietra, D., Casalone, R., Barbui, T., Rotunno, G., Cazzola, M., Vannucchi, A. M., Passamonti, F., and De Stefano V. (ORCID:0000-0002-5178-5827)

Abstract

N/A

Published
2018

31. Phenotype variability of patients with post polycythemia vera and post essential thrombocythemia myelofibrosis is associated with the time to progression from polycythemia vera and essential thrombocythemia

Author

Mora, B., Giorgino, T., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Barraco, D., Pietra, D., Barbui, T., Rotunno, G., Vannucchi, A. M., Passamonti, F., De Stefano V. (ORCID:0000-0002-5178-5827), Mora, B., Giorgino, T., Guglielmelli, P., Rumi, E., Maffioli, M., Rambaldi, A., Caramella, M., Komrokji, R., Gotlib, J., Kiladjian, J. J., Cervantes, F., Devos, T., Palandri, F., De Stefano, Valerio, Ruggeri, M., Silver, R. T., Benevolo, G., Albano, F., Cavalloni, C., Barraco, D., Pietra, D., Barbui, T., Rotunno, G., Vannucchi, A. M., Passamonti, F., and De Stefano V. (ORCID:0000-0002-5178-5827)

Abstract

N/A

Published
2018

32. Effect of Temperature on The Kinetics of Electrochemical Insertion of Li-Ions into a Graphite Electrode Studied by Kinetic Monte Carlo.

Author

Gavilán-Arriazu, E. M., Mercer, M. P., Pinto, O. A., Oviedo, O. A., Barraco, D. E., Hoster, H. E., and Leiva, E. P. M.

Subjects
TEMPERATURE effect, LITHIATION, ACTIVATION energy, HIGH temperatures, CHARGE transfer, DIFFUSION coefficients, ANALYTICAL mechanics, GRAPHITE
Abstract

The effect of temperature on the kinetics of electrochemical insertion/removal of lithium in graphite is analyzed by kinetic Monte Carlo methods. Different electrochemical techniques are simulated at different temperatures and responses are compared with experimental results. Simulated voltammograms show, similarly to experiment, how the behavior of the system becomes closer to equilibrium as temperature increases. Calculated chronoamperometric profiles show a different qualitative behavior in the current at different temperatures, especially in the Cottrell representation peaks, explained in terms of the relative importance of diffusive versus charge transfer processes at different temperatures. Results at room temperature are in good agreement with experiment, and we further evaluate trends at elevated temperature that have not yet been described in experimental or theoreticalworks. Exchange current densities for different degrees of lithium intercalation at different temperatures are predicted using potentiostatic simulations, showing an Arrhenius-type relationship. The dependence of the exchange current on electrolyte composition is simulated by investigating the effect of different activation energy barriers at different temperatures. The influence of temperature on diffusion coefficients as a function of lithiation fraction in graphite is simulated and related to Arrhenius plots, explaining the experimentally observed changes in diffusion phenomena with lithium composition and temperature. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

39. Shedding Light on the Entropy Change Found for the Transition Stage II→Stage I of Li-Ion Storage in Graphite.

Author

Leiva, E. P. M., Perassi, E., and Barraco, D.

Subjects
GRAPHITE, LITHIUM, INTERCALATION reactions
Abstract

In order to examine the controversial hypothesis put forward to explain the entropy step experimentally observed for the stage II to stage I transition for lithium intercalation in graphite, a transparent statistical mechanical model is developed. The results obtained show that the entropy increase can be explained by the change of configurational entropy occurring at occupation of half of the lattice. Comparison with experimental data shows that attractive interactions between intercalated particles in the same layer must be assumed, in agreement with the ansatz made in the original experimental work. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

47. f( R) Cosmology in the First Order Formalism.

Author

Barraco, D., Hamity, V., and Vucetich, H.

Abstract

In the present work we consider those theories that are obtained from a Lagrangian density ℒ T( R) = f( R)√{-g} + ℒ M, that depends on the curvature scalar and a matter Lagrangian that does not depend on the connection, and apply Palatini's method to obtain the field equations. We start with a brief discussion of the field equations of the theory and apply them to a cosmological model described by the FRW metric. Then, we introduce an auxiliary metric to put the resultant equations into the form of GR with cosmological constant and coupling constant that are curvature depending. We show that we reproduce known results for the quadratic case. We find relations among the present values of the cosmological parameters q0, H0, $$\mathop {(G/G)}\limits^ \circ _0$$ and $$\mathop {(G/G)}\limits^{ \circ \circ } _0 $$ . Next we use a simple perturbation scheme to find the departure in angular diameter distance with respect to General Relativity. Finally, we use the observational data to estimate the order of magnitude of what is essentially the departure of f( R) from linearity. The bound that we find for f″ (0) is so huge that permit almost any f( R). This is in the nature of things: the effect of higher order terms in f( R) are strongly suppressed by power of Planck's time 8π G0. In order to improve these bounds more research on mathematical aspects of these theories and experimental consequences is necessary. [ABSTRACT FROM AUTHOR]

Published
2002
Full Text
View/download PDF

48. The effects of dieldrin and chlordimeform on learning and memory in the cockroach,Periplaneta Americana: A study in behavioral toxicology

Author

Siegel D, Barraco D, Topinka Ma, Eisenstein Em, and Trofeli R

Subjects
Male, medicine.medical_specialty, Time Factors, education, Chlordimeform, Amidines, Cockroaches, Audiology, Toxicology, Behavioral toxicology, chemistry.chemical_compound, Dieldrin, Memory, biology.animal, Animals, Learning, Medicine, Acute dose, Cockroach, biology, business.industry, Environmental Exposure, Chlorphenamidine, biology.organism_classification, Pollution, chemistry, business, Periplaneta
Abstract

A one-session T-maze training procedure for cockroaches in which animals were trained to turn right or left to avoid a shock was utilized to investigate the effects of dieldrin and chlordimeform (two neurotoxic pesticides) on learning and memory. These animals were trained and then tested for retention 5 h later. Three behavioral measures were recorded: choice behavior or direction turned, the time taken to proceed down the runway (runway time), and the time taken to proceed from the runway to either choice arm (choice point time). In control animals the number of correct choices, the runway time, and the choice point time increased with succeeding trials during training. Furthermore, control animals showed retention of correct choice behavior from training to testing. A nontoxic dose (no overt behavioral signs) of dieldrin was injected 2 h before training or 15 min after training. Pretraining injections of dieldrin eliminated correct-choice learning but did not alter the increase with training in runway or choice point times. Posttraining dieldrin administration did not interfere with retention of correct-choice behavior upon testing. These findings indicate that dieldrin induces behavioral alterations in a low acute dose and that detrimental effects are more likely with more complex behavior. Furthermore, behavioral disruption is more likely the closer exposure is to the initial learning of a task. Nontoxic doses of chlordimeform injected 1 h before training eliminated correct-choice learning and facilitated an increase in runway times during training.

Published
1984

Catalog

Books, media, physical & digital resources
See catalog results