945 research outputs found

    Merio Scattola, L'utopia delle passioni. Ordine della società e controllo degli affetti nell'Isola di Felsenburg (1731-1745) di Johann Gottfried Schnabel. 2002

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    Dieses Buch liefert erstmals die überzeugende Begründung dafür, daß Johann Gottfried Schnabel als Autor der Frühaufklärung gelten kann, und erklärt gleichzeitig, weshalb ihm aber dieses literaturgeschichtliche Etikett nicht gänzlich gerecht wird. Es ist vielleicht kein Zufall, daß eine neue, differenziertere Sicht auf Schnabel von einem profilierten Historiker der politischen Theorien der frühen Neuzeit kommt, der nicht von vornherein geneigt ist, Schnabels Werk Insel Felsenburg allein in den Grenzen der literarischen Gattung Roman als Utopie und Robinsonade zu lesen, wie es die germanistische Literaturwissenschaft lange getan hat. Vielmehr berücksichtigt Merio Scattola die doppelte epistemische Schwelle, welche die deutschen Romane des frühen 18. Jahrhunderts noch nicht überschritten hatten: die der Literaturproduktion unter den Bedingungen der entstehenden Nationalphilologien des 19. sowie die der Autonomieästhetik am Ende des 18. Jahrhunderts (S. 16f.). So kommt er im Blick auf sein Forschungsobjekt denn auch auf andere Wege und Frage

    Bernhard Huss

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    A singular stochastic control problem for hydropower generation in renewable energy markets

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    We consider a singular stochastic control problem for hydroelectric power production in an energy market where the electricity spot market prices dynamics is described by a Vasicek's process, allowing also for negative prices. We propose a hydroelectric production system that can react in two different modes when it is convenient to produce energy through an instantaneous release of water. We endow the system with the possibility of producing ``less efficiently'' when negative prices appear in the market, but it is still preferable to produce instantaneously rather than waiting for positive prices. We defined a novel optimization problem whose performance functional exhibits a state-dependent instantaneous marginal revenue whose sign is directly affected by the sign of the prices dynamics. We aim to maximize such functional among all the admissible control policies into the class of the adapted stochastic processes whose paths are not necessarily absolutely continuous with respect to the Lebesgue's measure but only non-decreasing, left-continuous and with finite right limits (càglàd). We prove the Verification Theorem, allowing to characterize the value function of our singular stochastic control problem among the solutions of the associated Hamilton-Jacobi-Bellman equation which turns to be a variational inequality with state-dependent gradient constraint. The Verification Theorem sheds light on the structure of the optimal control which turns to be a purely discontinuous process that, at the first time of action, exerts all the available fuel with a single instantaneous jump. Under some assumptions on the characteristics of our hydropower production model, we identify the value function of the optimal control problem in terms of the optimal reward function of an associated family of optimal stopping problems. We identified a unique positive boundary, separating the action and inaction regions and we showed that the optimal strategy consists in completely discharge the water reservoir as soon as the price dynamics reaches values grater or equal such optimal threshold. We highlight the difficulties that arise when the aforementioned assumptions are replaced by other alternative hypotheses. In this more challenging context, we provide some intuitions on the tricky structure of the action and inaction regions as well as on the nature of the candidate optimal control policy

    MA_MISS FM TEST CAMPAIGN AT ROVER LEVEL – DATA ANALYSIS

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    This document reports on the Test Campaign performed during 2019-2020 on the Ma_MISS Flight Model, integrated onboard the ExoMars Rover. Tests have been carried out both by using the Drill movement (Acquisition type C) and without Drill motion (Acquisition type A), and consisted in acquiring signals with and without targets, with Ma_MISS lamp switched on/off, at different integration times; several Operation Procedures (OPs) have been tested. Moreover functional health checks have also been carried out

    In silico screening of nanoporous materials for urea removal in hemodialysis applications

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    The design of miniaturized hemodialysis devices, such as wearable artificial kidneys, requires regeneration of the dialysate stream to remove uremic toxins from water. Adsorption has the potential to capture such molecules, but conventional adsorbents have low urea/water selectivity. In this work, we performed a comprehensive computational study of 560 porous crystalline adsorbents comprising mainly covalent organic frameworks (COFs), as well as some siliceous zeolites, metal organic frameworks (MOFs) and graphitic materials. An initial screening using Widom insertion method assessed the excess chemical potential at infinite dilution for water and urea at 310 K, providing information on the strength and selectivity of urea adsorption. From such analysis it was observed that urea adsorption and urea/water selectivity increased strongly with fluorine content in COFs, while other compositional or structural parameters did not correlate with material performance. Two COFs, namely COF-F6 and Tf-DHzDPr were explored further through Molecular Dynamics simulations. The results agree with those of the Widom method and allow to identify the urea binding sites, the contribution of electrostatic and van der Waals interactions, and the position of preferential urea–urea and urea–framework interactions. This study paves the way for a well-informed experimental campaign and accelerates the development of novel sorbents for urea removal, ultimately advancing on the path to achieve wearable artificial kidneys

    Mixed Matrix Membranes based on PPO and graphene for gas separation

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    Novel composite Mixed Matrix Membranes (MMM) were fabricated by dispersion of different loadings of graphene nanoparticles (from 0.3 to 15 % weight percentage) in a dense permeable glassy polymer, poly (2,6-dimethyl-1,4-phenylene oxide), PPO, by solvent casting procedure. The permeability, selectivity and diffusivity of helium, nitrogen and carbon dioxide have been measured at two different temperatures, 35° and 65°C and the effect of graphene loading was studied. (R. Rea et al. 2018)

    Micro-imaging VIS-IR spectroscopy of Martian meteorites in support of the future MaMIss spectrometer measurements

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    In the view of the future ExoMars 2020 mission, an activity of VIS-IR spectral investigations on terrestrial and extraterrestrial Mars Analogues is ongoing, in support of the Ma Miss in situ measurements. Ma_Miss is an imaging spectrometer that works in the range 0.4-2.2 μm with 20nm spectral sampling and that will observe the lateral wall of the borehole generated by ExoMars Rover's drill (Coradini et al., 2001). In this abstract, we describe some results about the spectral properties and characterization of mineral grains of the slabs of two Martian meteorites by means of the SPIM imaging spectrometer. SPIM works in the 0.22-5.05 μm spectral range, with a spatial resolution of 38x38 μm on the sample and represents the spare of the spectrometer on Dawn spacecraft (De Angelis et al., 2015). The meteorites investigated are North West Africa 8657 (NWA8657) and Dar Al Gani 489 (DAG489), basaltic shergottites. The average spectrum of the NWA8657 slab, in comparison with spectral measurements on other martian meteorites (Mcfadden & Cline, 2005) shows low reflectance values and 1 and 2 μm spectral absorptions indicating the strong presence of Ca-pyroxenes. The successive pixel by pixel analyses for the pyroxenes spectral speciation showed a great variability of clinopyroxenes in NWA8657. In fact, the 2 μm absorption at longer wavelength in some pixel does not always correspond to the 1 μm feature at longer wavelength. The average spectrum of DAG 489 is marked by a signature typical of low-Ca pyroxenes. Pixel by pixel analyses of DAG489 shows a more homogeneous composition of the pyroxenes characterized by the two major features centered at 0.98-0.99 and 1.98-2 μm. Further spectral absorptions related to sulfates, phosphates and carbonates were detected that are being validated by SEM-BSD to constrain the formation hystories of these two shergottites

    A randomized blinded retrospective study: the combined use of micro-needling technique, low-level laser therapy and autologous non-activated platelet-rich plasma improves hair re-growth in patients with androgenic alopecia

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    Introduction Mini-invasive therapies based on autologous non-activated Platelet-Rich Plasma (ANA-PRP), Low-Level Laser Therapy (LLL-T), and Micro-Needling Technique (MN-T) used in combining for hair re-growth need to be standardized. Objectives The work aims to showin vivooutcomes resulted from retrospective case-series study in which ANA-PRP + MN-T + LLL-T were used in combined in patients affected by Androgenic alopecia. Methods 23 patients were treated, of which 13 males were classified in stage I-V by the Norwood-Hamilton scale, and 10 females were classified in stage I-III by the Ludwig scale. Assessment of hair re-growth was evaluated with photography, physician's and patient's global assessment scale, and standardized phototrichograms during a follow-up: T0 - baseline, T1 - 12 weeks, T2 - 23 weeks, T3 - 44 weeks, T4 - 58 weeks. Results Interesting outcomes represented by a hair density increase of 81 +/- 5 hairs/cm(2)and 57 +/- 7 hairs/cm(2)respectively at T1 and T2 compared with baseline (173 +/- 5 hairs/cm(2)at T1 and 149 +/- 9 hairs/cm(2)at T2 versus 92 +/- 2 hairs/cm(2)at baseline) were observed using computerized trichograms. Expert Opinion The main limitation in the autologous regenerative therapies and biotechnologies in hair-regrowth is the extreme variability of PRP products used, in the absence of standardized protocols and widely shared. Appropriate PRP preparations have to be pick after carefully thinking about their bio-molecular specifications and intended indications for use in patients. This approach will aid in matching the optimal PRP product to specific patient factors, leading to improved outcomes and the elucidation of the cost-effectiveness of this treatment. The combined use of biotechnologies as the association of PRP with micro-needling and low-level laser therapy may improve the results in terms of hair count and hair density compared with those obtained by alone PRP. All the procedures must be performed in the full respect of international and local rules. Conclusions The effect of the combined use of MN-T, LLL-T, and ANA-PRP has been demonstrated

    Identification of a Ca-Phosphate Grain in North West Africa 8657 Martian Meteorite by VIS-IR Micro-Imaging Spectroscopy

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    This abstract focuses on the VIS-IR imaging spectroscopy investigation on some grains of merrillite in the North West Africa 8657 shergottite slab
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