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Search Results: 1 - 10 of 219728 matches for " C. Sasso "
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Milne-Eddington inversions of the He I 10830 ? Stokes profiles: Influence of the Paschen-Back effect
C. Sasso,A. Lagg,S. K. Solanki
Physics , 2011, DOI: 10.1051/0004-6361:20065257
Abstract: The Paschen-Back effect influences the Zeeman sublevels of the He I multiplet at 10830 {\AA}, leading to changes in strength and in position of the Zeeman components of these lines. We illustrate the relevance of this effect using synthetic Stokes profiles of the He I 10830 {\AA} multiplet lines and investigate its influence on the inversion of polarimetric data. We invert data obtained with the Tenerife Infrared Polarimeter (TIP) at the German Vacuum Tower Telescope (VTT). We compare the results of inversions based on synthetic profiles calculated with and without the Paschen-Back effect being included. We find that when taking into account the incomplete Paschen-Back effect, on average 16% higher field strength values are obtained. We also show that this effect is not the main cause for the area asymmetry exhibited by many He I 10830 Stokes V-profiles. This points to the importance of velocity and magnetic field gradients over the formation height range of these lines.
Magnetic structure of an activated filament in a flaring active region
C. Sasso,A. Lagg,S. K. Solanki
Physics , 2013, DOI: 10.1051/0004-6361/201322481
Abstract: While the magnetic field in quiescent prominences has been widely investigated, less is known about the field in activated prominences. We introduce observational results on the magnetic field structure of an activated filament in a flaring active region. We study, in particular, its magnetic structure and line-of-sight flows during its early activated phase, shortly before it displays signs of rotation. We invert the Stokes profiles of the chromospheric He I 10830 A triplet and the photospheric Si I 10827 A line observed in this filament by the VTT on Tenerife. Using these inversion results we present and interpret the first maps of velocity and magnetic field obtained in an activated filament, both in the photosphere and the chromosphere. Up to 5 different magnetic components are found in the chromospheric layers of the filament, while outside the filament a single component is sufficient to reproduce the observations. Magnetic components displaying an upflow are preferentially located towards the centre of the filament, while the downflows are concentrated along its periphery. Also, the upflowing gas is associated with an opposite-polarity magnetic configuration with respect to the photosphere, while the downflowing gas is associated with a same-polarity configuration. The activated filament has a rather complex structure. Nonetheless, it is compatible with a flux rope, although with a distorted one, in the normal configuration. The observations are best explained by a rising flux rope in which a part of the filament material is still stably stored (upflowing material, rising with the field), while a part is no longer stably stored and flows down along the field lines.
The watt-balance operation: magnetic force and induced electric potential on a conductor in a magnetic field
C. P. Sasso,E. Massa,G. Mana
Physics , 2012, DOI: 10.1088/0026-1394/50/2/164
Abstract: In a watt balance experiment, separate measurements of magnetic force and induced electric potential in a conductor in a magnetic field allow for a virtual comparison between mechanical and electrical powers, which leads to and an accurate measurement of the Planck constant. In this paper, the macroscopic equations for the magnetic force and the induced electric potential are re-examined from a microscopic point of view and the corrective terms due to a non-uniform density of the conduction electrons induced by their interaction with the magnetic field are investigated. The results indicate that these corrections are irrelevant to the watt balance operation.
Multicomponent He I 10830 ? profiles in an active filament
C. Sasso,A. Lagg,S. K. Solanki
Physics , 2011, DOI: 10.1051/0004-6361/200912956
Abstract: We present new spectropolarimetric observations of the chromospheric He I 10830 {\AA} multiplet observed in a filament during its phase of activity. The data were recorded with the new Tenerife Infrared Polarimeter (TIP-II) at the German Vacuum Tower Telescope (VTT) on 2005 May 18. We inverted the He Stokes profiles using multiple atmospheric components. The observed He Stokes profiles display a remarkably wide variety of shapes. Most of the profiles show very broad Stokes I absorptions and complex and spatially variable Stokes V signatures. The inversion of the profiles shows evidence of different atmospheric blue- and redshifted components of the He I lines within the resolution element (1 arcsec), with supersonic velocities of up to 100 km/s. Up to five different atmospheric components are found in the same profile. We show that even these complex profiles can be reliably inverted.
Modelling solar low-lying cool loops with optically thick radiative losses
C. Sasso,V. Andretta,D. Spadaro
Physics , 2015, DOI: 10.1051/0004-6361/201526598
Abstract: We investigate the increase of the DEM (differential emission measure) towards the chromosphere due to small and cool magnetic loops (height $\lesssim8$~Mm, $T\lesssim10^5$~K). In a previous paper we analysed the conditions of existence and stability of these loops through hydrodynamic simulations, focusing on their dependence on the details of the optically thin radiative loss function used. In this paper, we extend those hydrodynamic simulations to verify if this class of loops exists and it is stable when using an optically thick radiative loss function. We study two cases: constant background heating and a heating depending on the density. The contribution to the transition region EUV output of these loops is also calculated and presented. We find that stable, quasi-static cool loops can be obtained by using an optically thick radiative loss function and a background heating depending on the density. The DEMs of these loops, however, fail to reproduce the observed DEM for temperatures between $4.6<\log T<4.8$. We also show the transient phase of a dynamic loop obtained by considering constant heating rate and find that its average DEM, interpreted as a set of evolving dynamic loops, reproduces quite well the observed DEM.
Raman Tweezers as a Diagnostic Tool of Hemoglobin-Related Blood Disorders
Giulia Rusciano,Anna C. De Luca,Giuseppe Pesce,Antonio Sasso
Sensors , 2008, DOI: 10.3390/s8127818
Abstract: This review presents the development of a Raman Tweezers system for detecting hemoglobin-related blood disorders at a single cell level. The study demonstrates that the molecular fingerprint insight provided by Raman analysis holds great promise for distinguishing between healthy and diseased cells in the field of biomedicine. Herein a Raman Tweezers system has been applied to investigate the effects of thalassemia, a blood disease quite diffuse in the Mediterranean Sea region. By resonant excitation of hemoglobin Raman bands, we examined the oxygenation capability of normal, alpha- and beta-thalassemic erythrocytes. A reduction of this fundamental red blood cell function, particularly severe for beta-thalassemia, has been found. Raman spectroscopy was also used to draw hemoglobin distribution inside single erythrocytes; the results confirmed the characteristic anomaly (target shape), occurring in thalassemia and some other blood disorders. The success of resonance Raman spectroscopy for thalassemia detection reported in this review provide an interesting starting point to explore the application of a Raman Tweezers system in the analysis of several blood disorders.
Procedimentos metodológicos na constru??o do conhecimento científico: a pesquisa bibliográfica
Lima, Telma Cristiane Sasso de;Mioto, Regina Célia Tamaso;
Revista Katálysis , 2007, DOI: 10.1590/S1414-49802007000300004
Abstract: this article concerns bibliographic research in the context of production of knowledge, as a methodological procedure that offers the researcher the possibility of seeking solutions to a research problem. it recognizes the need to present the scientific method chosen by the researcher; to present the forms of construction of the methodological design and the choice of procedures; and demonstrates how the presentation and analysis of the data obtained is configured. it also presents a methodological design of successive approximations, considering that the flexibility in the apprehension of data guarantees the dialectical movement in which the object of study can be constantly revised. that is, it postulates that bibliographic research involves conducting a tireless movement of apprehension of objectives, observance of steps, reading, questioning and critical interlocution with the bibliographic material and this demands epistemological vigilance.
A dimens o técnico-operativa do Servi o Social em foco: sistematiza o de um processo investigativo
Mioto, Regina Célia Tamaso,Lima, Telma Cristiane Sasso de
Textos & Contextos (Porto Alegre) , 2009,
Abstract: O presente artigo problematiza a dimens o técnico-operativa do exercício profissional dos assistentes sociais, no contexto do projeto da profiss o, articulando-a às dimens es teórico-metodológica e ético-política. Apresenta, inicialmente, algumas observa es sobre quest es vinculadas ao exercício profissional, tendo como base a produ o bibliográfica da área de Servi o Social e dados de pesquisas referentes ao trabalho profissional. Em seguida, concentra-se na defini o e discuss o das a es profissionais, entendendo-as como o vetor fundamental para o desvelamento dos processos interventivos dos assistentes sociais. Posteriormente, discute como tais a es se articulam e se diferenciam entre si, chegando à proposi o de três eixos articuladores, intrínsecos e dialeticamente relacionados, denominados de processos político-organizativos, processos de gest o e planejamento e processos socioassistenciais. Finalmente exp e possíveis contribui es da sistematiza o efetuada.
BINDING TO AND RETENTION BY MUCOSAL CELLS OF THE TAMARINDUS INDICA SEED POLYSACCHARIDE: VISUAL EVALUATION BY MEANS OF INORGANIC AND ORGANIC MARKERS
P.C. Braga*, M. Dal Sasso, M. Culici
International Journal of Pharmaceutical Sciences and Research , 2012,
Abstract: The aim of this study was to investigate the possibility of using inorganic and organic markers to visualize the ability of the transparent polysaccharide (TSP) polymer isolated from the endosperm of the seed kernel of Tamarindus indica, a tree that mainly grows in India and South-East Asia, to bind to human mucosal cells. A layer of human buccal cells was prepared on slides and overlaid by 0.2 ml of 0.6, 0.3, 0.15 and 0.075 % TSP solutions in phosphate buffer and then colloidal carbon black particles were deposited on the slides. The unbound colloidal carbon black particles were cleared by thoroughly washing the slides. The slides were then examined by means of Nomarski interference contrast microscopy in order to visualize the degree of surface retention of the black particles by the buccal cells. The same procedure was followed using Escherichia coli as organic markers. The clearly visible binding of black carbon particles to the cells treated with polymer revealed the presence of a thin layer of TSP covering the cells (untreated cells had no black carbon particles binding). The presence of the TSP has also been confirmed by a significant reduction in bacterial adhesiveness. Both markers made it possible to visualize the binding of the thin transparent layer of TSP and its retention, which was proportional to the degree of dilution. Using Escherichia coli it has been observed the possibility of counteracting the lock-and-key mechanism of micro-organism adhesion using the bioadhesive properties of this polymer to prevent possible contact between microorganism adhesins and complementary receptors.
Rate dependence of the magnetocaloric effect in La-Fe-Si compounds
Kuepferling M.,Sasso C.P.,Basso V.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134006010
Abstract: The dynamic magnetocaloric effect in La(FexCoySi1-x-y)13 with x=0.9 and low Co content of y=0.015 was analysed by calorimetric measurements at constant magnetic field and constant temperature as well as magnetisation relaxation measurements. It is shown that the rate dependence of the measurement, which leads to an increased entropy hysteresis with increasing rate of the driving force (temperature or magnetic field), can be mainly attributed to a thermal contact resistance R between sample and thermal bath of the measurement setup.
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