16,106 research outputs found
Kinetic theory of dusty plasmas. IV. Distribution and fluctuations of dust charges
No full textThe recent results of the kinetic theory of dusty plasmas [V. N. Tsytovich and U. de Angelis, Phys. Plasmas 6, 1093 (1999)] are used to investigate the distribution and fluctuations of the dust charges in dusty plasmas. It is shown that the charge fluctuations induced by dust discreteness can be larger than the fluctuations due to electron and ion discreteness. A new Lorentz form for the regular part of the dust charge distribution is found. (C) 2002 American Institute of Physics
Storiografie multiple in L'uomo nell'alto castello
No full textIl saggio appare in una raccolta di contributi (a cura di Umberto Rossi e dell’autore stesso) che mirano a situare Philip K. Dick nel panorama letterario e culturale statunitense e internazionale, analizzare alcuni dei suoi romanzi più rappresentativi (fantascientifici e non), e a puntualizzare l’influenza di Dick sul cinema contemporaneo. Nel saggio si mette in luce la complessa riarticolazione dei vari livelli di realtà in L’uomo nell’alto castello, uno dei massimi esempi di storia alternativa o ucronia, offrendo una prospettiva inedita che coinvolge il grande omonimo del romanziere (fittizio) che all’interno del romanzo di Dick, ambientato in un mondo in cui la Germania e il Giappone hanno vinto la Seconda guerra mondiale, scrive a sua volta un romanzo ambientato in un mondo (comunque diverso dal nostro) in cui a vincere la guerra sono stati gli Alleati. Sebbene finora nessuno l’abbia ancora notato, Hawthorne Abendsen non può non richiamare Nathaniel Hawthorne, e le sue sottili e oblique procedure di riscrittura e deformazione della storia ufficiale. Il saggio indaga quindi le modalità di interrelazione tra le diverse “costruzioni” della realtà storica, e le possibili influenze del “revisionismo storiografico” di Hawthorne sul romanzo di Dick
Erratum to: A Regenerative Approach with Dermal Micrografts in the Treatment of Chronic Ulcers (Stem Cell Rev and Rep, 10.1007/s12015-016-9692-2)
No full textThe original version of this article unfortunately contained a mistake. The name of the seventh author was incorrectly listed as Gabriella Maria Casella De Angelis, when it is actually Gabriella Maria Cusella De Angelis. The correct information is as shown above. The original article was corrected
Low frequency responses, and wave dispersion in dusty plasmas
No full textThe self-consistent dusty-plasma response found in the kinetic theory [V. N. Tsytovich and U. de Angelis, Phys. Plasmas 6, 1093 (1999)] is generalized to include collisions of all species with neutrals, a situation often important in the experiments, and used to derive a new dispersion relation for low-frequency waves in dusty plasmas. An estimate of the differences with previous results is given for the particular case of dust-acoustic waves without the effects of collisions with neutrals: the present theory reproduces the result of Rao, Shukla, and Yu [Planet. Space Sci. 38, 543 (1990)] only for low dust density and small wavelengths, but strong deviations occur at larger wavelengths and dust densities
Influence of the characteristics of isolation and mitigation devices on the response of single-degree-of-freedom vibro-impact systems with two-sided bumpers and gaps via shaking table tests
No full textDuring strong earthquakes, structural pounding may occur between structures (buildings, bridges, strategic facilities, critical equipment, etc.) and the surrounding moat wall because of the limited separation distance and the deformations of the isolator. An arrangement that favors the solution of this problem is the interposition of shock absorbers. Thus, the influence of geometrical and mechanical characteristics of isolation and mitigation devices on nonlinear, nonsmooth response of vibro-impact systems is experimentally investigated in this paper on the basis of a laboratory campaign of experimental tests. Shaking table tests were carried out under a harmonic excitation in order to investigate two different configurations: the absence and the presence of bumpers. Three different values of the table acceleration peak were applied, four different amplitude values of the total gap between mass and bumpers were considered, and also four different types of bumpers were employed; moreover, two problems were addressed, namely, control of excessive displacements and control of excessive accelerations, and hence, two types of normalization were adopted in order to better interpret experimental results. Suitable choices of pairs of bumpers and gaps were suggested as a trade-off between conflicting objectives. Furthermore, a numerical model was proposed, and its governing parameters identified in order to simulate the experimental results
Going back home. The politics of the blues in Langston Hughes’ "The Backlash Blues”
No full textOne of Langston Hughes’s very last poems brought him back to his origins, both poetical and political. “The Backlash Blues,” published in the collection The Panther and the Leash (1967), was immediately recorded by Nina Simone in her album Nina Simone Sings the Blues (1967) precisely because she detected in the poem that interplay between the blues form and the rhetoric of political engagement which was at the very heart of Langston Hughes’s early career, and had been somehow abandoned by the poet after World War 2, and especially after his being investigated by the McCarthy Committee for his former Communist allegiances. In some sense, the title of the poem, which openly refers to the “backlash” white dominant culture is about to experience, according to Hughes, under the pressure of the Civil Rights Movement, is also a (not so) covert allusion to the need of both the poet himself and of the African Americancommunity in general to go back to their origins, rooted in that aesthetics of the blues critics like Houston Baker and Henry Louis Gates see as the “matrix” of “black” culture. My paper will try to show the strategies Hughes deploys to make the blues politically relevant once again in the 1960s as it was in the 1920s (when Bessie Smith’s “Poor Man’s Blues,” the inspiration for Hughes’s poem, was recorded), and also to create a connection between the two historical periods when African Americans were able to obtain a central role in the processes that were deeply redefining US political and cultural identity
I percorsi autorizzativi critici, nella progettazione
No full texta cura A. Ciribini, E. De Angelis, A. Ferr
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