54 research outputs found
Performance of annealed hybride silicon heterojunctions: a numerical computer study
No full textThe performance of the standard hydrogenated amorphous silicon carbon–crystalline silicon solar cell is extensively compared with the performance of a hybrid structure subjected to a high-temperature annealing processing. Our analysis indicates that high-temperature-annealed heterojunctions show more robustness in the presence of energy offsets and defective amorphous-crystalline interfaces. Annealed hybrid cells are also less vulnerable to the negative impact of amorphous silicon carbon doped layers with poor electrical properties. Furthermore, annealed structures have the potential to generate higher efficiencies than conventional heterojunctions regardless of the wafer quality. The presence of boron at the amorphous-crystalline interface and in the wafer front region plays an important role in annealed hybrid structures that are made with low-quality wafers or where there is a highly defective amorphous-crystalline interface. In this scenario, a linear boron profile in the wafer front region is more appropriate, for which there is an optimum thickness. For low defect amorphous-crystalline interfaces and high-quality wafers, a boron exponential profile is more appropriate when boron creates additional defects in the front region of the wafer. The shape of the boron profile becomes less relevant when the boron does not add additional defects to the front region of high-quality wafers and when the amorphous-crystalline interface is low defect or defect-free.Fil: Rubinelli, Francisco Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Marsal, L. F.. Universitat Rovira I Virgili; EspañaFil: Pallarès, J.. Universitat Rovira I Virgili; Españ
Numerical Simulation of III-V Solar Cells Using D-AMPS
No full textNumerical simulation of devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. Here, we present results obtained using the code D-AMPS-1D, that was conveniently modified to consider the particularities of III-V solar cell devices. This work, that is a continuation of a previous paper regarding solar cells for space applications, is focused on solar cells structures than find application for terrestrial use under concentrated solar illumination. The devices were fabricated at the Solar Energy Institute of the Technical University of Madrid (UPM). The first simulations results on InGaP cells are presented. The influence of band offsets and band bending at the window-emitter interface on the quantum efficiency was studied. A remarkable match of the experimental quantum efficiency was obtained. Finally, numerical simulation of single junction n-p InGaP-Ge solar cells was performed
Dizionario Biografico degli Italiani, vol. 89: Rovereto-Salvemini
No full textDal 2012 il sottoscritto (L Bianconi) fa parte del Comitato di direzione scientifica del "Dizionario biografico degli Italiani", per il quale cura le voci relative alla musica e alla danza (compositori, esecutori, librettisti, impresari, editori, ecc.). Il vol. 89 comprende le seguenti voci, che sono state tutte assoggettate a rigorosa verifica sulle fonti e in svariati casi (contrassegnati da un asterisco) sottoposte a incisive revisioni e finanche radicali rifacimenti effettuati dal sottoscritto: *G. Rovetta, *F. Rovigo, G.M.R. Rubinelli, G.B. Rubini, *B. Rubino, V. Ruffo, fam. Rugeri (liutai), C. Rusca, *L. Russolo, C. Rustichelli, *F. Rustichelli Galletti Gianoli, G. Ruta, B. Sabadini, G. Sabbatini, *L.A. Sabbatini, P.P. Sabbatini, fam. Sabino, I. Sabino, G. Sacchi, *A. Sacchini, S.F. Sacconi, *F. Sacrati, G. Sala, *N. Sala, P.P. Sales, *M. Salicola, *A. Salieri, F. Salimbeni, A. Salvadori, G. Salvator
Doctors' Insights into the Patient Perspective: A Qualitative Study in the Field of Chronic Pain
No full textPurpose. To strengthen the conceptualization of the patient perspective by identifying aspects that, from doctors' point of view, are important to address during a consultation to build a partnership with patients. Method. Semistructured interviews were conducted with 17 doctors who are experts in the field of chronic pain in Italy. The recordings of the interviews were transcribed verbatim and interpreted using thematic analysis. Results. The participants agreed about the importance of doctors addressing aspects of the patient perspective that can lead to a difference of opinion with patients, namely, patients' views about their health condition (i.e., what they think they have and why and the perceived impact of the health condition on their life) and about treatments (i.e., what they have tried or have heard about and their expectations). Conclusions. Identifying patients' standpoints on their health condition and treatments offers an opportunity for critical discussion of differences of opinions and promotes communication exchange and agreement about the appropriate course of action
Building bridges between doctors and patients: the design and pilot evaluation of a training session in argumentation for chronic pain experts
No full textShared decision-making requires doctors to be competent in exchanging views with patients to identify the appropriate course of action. In this paper we focus on the potential of a course in argumentation as a promising way to empower doctors in presenting their viewpoints and addressing those of patients. Argumentation is the communication process in which the speaker, through the use of reasons, aims to convince the interlocutor of the acceptability of a viewpoint. The value of argumentation skills for doctors has been addressed in the literature. Yet, there is no research on what a course on argumentation might look like. In this paper, we present the content and format of a training session in argumentation for doctors and discuss some insights gained from a pilot study that examined doctors' perceived strengths and limitations vis-à-vis this training
On the mirror of the bicentenary
No full textSe analizan condiciones históricas de la conformación de la Región del
Noroeste argentino, con sus particulares características, así como incidencias
del proceso revolucionario de 1810 y algunas repercusiones del mismo en
el futuro de la Región. Se acude para ello al aporte de estudios históricos,
lingüísticos y antropológicos regionales, así como al testimonio de pensadores
comprometidos con su realidad. La población descendiente de los pueblos
originarios aparece sumergida en situaciones de desigualdad y explotación a lo
largo del período recorrido, lo que se expresa a través de obras de luchadores
como M. A. Tanco, J. L. Torres y el grupo Tarja. En la actualidad, y a pesar
de los avances realizados a nivel de Acuerdos y Declaraciones de organismos
internacionales, la demanda de su legítimo y efectivo reconocimiento es una
deuda pendiente, lo que conlleva connotaciones éticas que cuestionan las
bases de nuestro sistema democrático.The author analyzes the historical conditions of Argentina’s Northwest during
its conformation, and its particular characteristics through the revolutionary
process of 1810 and some of its repercussions in the future. Historical,
linguistic and regional anthropological studies are used in this analysis, as
well as the testimony of the engaged humanists (thinkers, philosophers) of
its time. The local native population appears in situations of inequality and
exploitation during this long period, as seen through the works of leaders
such as M. A. Tanco, J. L. Torres and the Tarja group. Currently, in spite of the
progress achieved at the level of Agreements and Declarations by international
organizations, their legitimate demand and actual recognition is a pending
debt, which carries ethical connotations that question the basic principles
of our democracy.Fil: Rubinelli, María Luisa.
Universidad Nacional de Juju
n-i-p Microcrystalline Tunnel Junction in a-Si:H/a-Si:H Tandem Cells
No full textThe kinetics controlling the electrical transport inside the μc-Si tunnel-recombination junction (TRJ) of a-Si:H/a-Si:H tandem solar cells was studied in detail with computer simulations. Trap assisted recombination tunneling and Poole–Frenkel mechanisms were included in our analysis. Three different μc-Si tunnel junctions were investigated: (a) n-p, (b) n-oxide-p and (c) n-i-p. The highest theoretical efficiencies in a-Si:H/a-Si:H tandem cells were achieved with the n-i-p tunnel junction structure. The impact of the μc-Si effective masses, mobility gap, and mobilities in the tandem solar cell efficiency is also studied in this article. Several a-Si:H/a-Si:H tandem solar cells were made with the μc-Si tunnel configurations of types (b) and (c). In all of these samples one extra oxide layer was needed at the i-a-Si:H/n-μc-Si interface. Both tunnel junctions lead us to comparable experimental tandem solar cell efficiencies. When the n-i-p structure is implemented as TRJ in the a-Si:H/a-Si:H tandem solar cell, efficiencies sensitively depend upon the tunnel junction intrinsic layer thickness. The optimization of this thickness provides a more controlled way of maximizing the tandem solar cell efficiency. Illuminated J–V and QE characteristics were successfully fitted using computer modeling.Fil: Rubinelli, Francisco Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Rath, J.K.. Utrecht University; Países BajosFil: Schropp, R.E.I.. Utrecht University; Países Bajo
Transport in tunnelling recombination junctions: a combined computer simulation study
No full textThe implementation of trap-assisted tunneling of charge carriers into numerical simulators ASPIN and D-AMPS is briefly described. Important modeling details are highlighted and compared. In spite of the considerable differences in both approaches, the problems encountered and their solutions are surprisingly similar. Simulation results obtained for several tunneling recombination junctions made of amorphous silicon (a-Si), amorphous silicon carbide (a-SiC), or microcrystalline silicon (µc-Si) are analyzed. Identical conclusions can be drawn using either of the simulators. Realistic performances of a-Si/a-Si tandem solar cells can be reproduced with simulation programs by assuming that extended-state mobility increases exponentially with the electric field. The same field-enhanced mobilities are needed in single tunneling recombination junctions in order to achieve measured current levels. Temperature dependence of the current-voltage characteristics indicates that the activation energy of enhanced mobilities should be determined. Apparent discrepancies between simulation results and measurements are explained and eliminated making use of Gill’s law. For application in tandem and triple solar cell structures, tunneling recombination junctions made of (µc-Si) are the most promising of all examined structures.Fil: Vukadinovic, M.. University of Ljubljana; EsloveniaFil: Smole, F.. University of Ljubljana; EsloveniaFil: Topič, M.. University of Ljubljana; EsloveniaFil: Schropp, R. E. .. Utrecht University; Países BajosFil: Rubinelli, Francisco Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin
Using computer modeling analysis in single a-SiGe:H p-i-n solar cells
No full textIn this article we discuss basic aspects of single junction a-SiGe:H p–i–n solar cells by coupling computer simulations with experimental characteristics. We are able to fit the dark illuminated current–voltage characteristics and the spectral response curves of a-SiGe:H p–i–n structures in the initial state, modeling the density of dangling bonds in each device layer by using either uniform density profiles or the defect pool model. Although we can fit these experimental curves with any of these two electrical models, band gap profiling in the a-SiGe:H intrinsic layer leads to improvement of the solar cell performance only when the defect pool model is implemented in our simulations. A U-shaped band gap profile is tailored in our samples by a staircase band gap profile composed of (i) several front band gap graded steps, (ii) one lowest band gap region, and (iii) several back band gap graded steps. Only by using the defect pool model are we able to predict an optimum thickness for the front band gap graded steps and for a buffer layer located at the p/i interface. Furthermore, using the defect pool model, the simulation predicts that higher efficiencies in single junction a-SiGe:H p–i–n solar cells can be achieved by depositing nonuniform graded steps, i.e., thicker band gap graded layers besides the lowest band gap a-SiGe:H layer and thinner band gap graded layers besides the p/i and i/n interfaces.Fil: Rubinelli, Francisco Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Jiménez, R.J.. Utrecht University; Países BajosFil: Rath, J.K.. Utrecht University; Países BajosFil: Schropp, R.E.I.. Utrecht University; Países Bajo
Nogo-A reduces ceramide de novo biosynthesis to protect from heart failure
No full textAims: Growing evidence correlate the accrual of the sphingolipid ceramide in plasma and cardiac tissue with heart failure (HF). Regulation of sphingolipid metabolism in the heart and the pathological impact of its derangement remain poorly understood. Recently, we discovered that Nogo-B, a membrane protein of endoplasmic reticulum, abundant in the vascular wall, down-regulates the sphingolipid de novo biosynthesis via serine palmitoyltransferase (SPT), first and rate liming enzyme, to impact vascular functions and blood pressure. Nogo-A, a splice isoform of Nogo, is transiently expressed in cardiomyocyte (CM) following pressure overload. Cardiac Nogo is up-regulated in dilated and ischaemic cardiomyopathies in animals and humans. However, its biological function in the heart remains unknown. Methods and results: We discovered that Nogo-A is a negative regulator of SPT activity and refrains ceramide de novo biosynthesis in CM exposed to haemodynamic stress, hence limiting ceramide accrual. At 7 days following transverse aortic constriction (TAC), SPT activity was significantly up-regulated in CM lacking Nogo-A and correlated with ceramide accrual, particularly very long-chain ceramides, which are the most abundant in CM, resulting in the suppression of 'beneficial' autophagy. At 3 months post-TAC, mice lacking Nogo-A in CM showed worse pathological cardiac hypertrophy and dysfunction, with ca. 50% mortality rate. Conclusion: Mechanistically, Nogo-A refrains ceramides from accrual, therefore preserves the 'beneficial' autophagy, mitochondrial function, and metabolic gene expression, limiting the progression to HF under sustained stress
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