3,467 research outputs found

    Postseismic deformation and body forces shaping the Apennines and adjacent sedimentary basins in Umbria-Marche

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    The geodynamic complexity of the Apennines and adjacent sedimentary basins in Umbria-Marche (North-Central Italy) makes the dynamics of the present day deformation and its relationships with the seismicity less well understood. In this paper, we argue that, further to buoyancy forces, postseismic deformation of earthquakes taking place on the Apennines contributes to the regional deformation. We investigate the interaction between the normal faulting system responsible of the 1997 Umbria-Marche earthquake sequence (Colfiorito fault) and the low angle normal faulting system bordering the sedimentary basins, namely the Altotiberina fault. We set-up a 2D finite element model of the lithosphere-asthenosphere accounting for lateral heterogeneities and investigate how this heterogeneous structure is capable of localizing strain under the Umbria-Marche sedimentary basins, providing a way for the Colfiorito fault to influence the evolution of the Altotiberina fault. We show how the two different length and time scale processes, namely postseismic deformation and buoyancy, are complementary in shaping the Apennines and adjacent sedimentary basins. The high resolution deformation patterns modeled in this study can hardly be reproduced by a model accounting only for external forces such as a rotating or subducting or retreating Adria

    Frequency Dynamics in Fully Non-Synchronous Electrical Grids: A Case Study of an Existing Island

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    The operation of a power system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the design and the control of the system. Existing literature on the integration of renewable energy sources in isolated systems mainly focuses on energy aspects or steady-state issues, and only a few studies examine the dynamic issues of autonomous networks operated with fully non-synchronous generation. A lack of research can be found in particular in the determination of the required amount of grid-forming power, the selection of the number and rated power of the units which should implement the grid-forming controls, and the relative locations of the grid-forming converters. The paper aims to address those research gaps starting from a theoretical point of view and then by examining the actual electrical network of an existing island as a case study. The results obtained from the investigations indicate specific observations and design opportunities, which are essential for securing the synchronization and the stability of the grid. Possible solutions for a fully non-synchronous operation of autonomous systems, in terms of dynamic characteristics and frequency stability, are presented and discussed

    Chronic mild stress-induced alterations of clock gene expression in rat prefrontal cortex: modulatory effects of prolonged lurasidone treatment

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    Disruptions of biological rhythms are known to be associated with depressive disorders, suggesting that abnormalities in the molecular clock may contribute to the development of these disorders. These mechanisms have been extensively characterized in the suprachiasmatic nucleus, but little is know about the role exerted by individual clock genes in brain structures that are important for depressive disorders. Using the chronic mild stress model we found a significant reduction of BMAL1 and CLOCK protein levels in the nuclear compartment of the prefrontal cortex of CMS rats, which was paralleled by a down-regulation of the expression of several target genes, including Pers and Crys but also Reverb\u3b2 and Ppar\u3b1. Interestingly, chronic treatment with the multi receptor modulator lurasidone (3 mg/kg for 5 weeks) was able to normalize the molecular changes induced by CMS exposure in prefrontal cortex, but it was also able to regulate some of these genes within the hippocampus. We believe that changes in clock genes expression after CMS exposure may contribute to the disturbances associated with depressive disorders and that the ability of chronic lurasidone to normalize such alterations may be relevant for its therapeutic properties in ameliorating functions that are deteriorated in patients with major depression and other stress-related disorders

    Electrochemical nanolithography on silicon: An easy and scalable method to control pore formation at the nanoscale

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    Lithography on a sub-100 nm scale is beyond the diffraction limits of standard optical lithography but is nonetheless a key step in many modern technological applications. At this length scale, there are several possible approaches that require either the preliminary surface deposition of materials or the use of expensive and time-consuming techniques. In our approach, we demonstrate a simple process, easily scalable to large surfaces, where the surface patterning that controls pore formation on highly doped silicon wafers is obtained by an electrochemical process. This method joins the advantages of the low cost of an electrochemical approach with its immediate scalability to large wafers

    Diferentes coeficientes de similaridade para análise de agrupamento de genótipos de Coffea canephora com base em marcadores moleculares.

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    O objetivo deste trabalho foi comparar o agrupamento de 80 genótipos de C. canephora com 15 diferentes coeficientes de similaridade, obtidos por meio de marcadores moleculares RAPD. Os coeficientes de similaridade analisados foram: Jaccard, Nei e Li, Ochiai, Índice II, Coincidência simples, Rogers e Tanimoto, Sokal e Sneath, Yule, Índice I, Haman, Ochiai II, Índice III, Russel e Rao, Baroni et al. e Sokal. As estimativas de similaridade (Sgii?) entre todos os pares de genótipos (ii?) foram convertidas em dissimilaridade por meio do complemento aritmético dos coeficientes utilizados (Dgii? = 1 - Sgii?). Para a análise de agrupamento dos genótipos foi empregado o método de otimização de Tocher. Verificaram-se diferenças quanto ao número de grupos formados com a utilização dos diferentes coeficientes de similaridade, variando de quatro a 43. Houve concordância entre os coeficientes de Jaccard, Nei e Li, Ochiai, Índice II, Coincidência simples, Rogers e Tanimoto, Sokal e Sneath, Yule, Índice I, Haman, Ochiai II, Índice III e Baroni et al. quanto ao agrupamento dos genótipos mais dissimilares e mais similares. Os coeficientes de Russel e Rao e Sokal apresentaram dados discrepantes e sugere-se que não sejam utilizados. Os resultados em conjunto caracterizam a necessidade de estudos complementares para acurácia na definição do (s) coeficiente (s) para a análise de dados moleculares obtidos por meio de marcadores dominantes RAPD em C. canephora

    An assessment of microstructure and properties of laser clad coatings of ultrafine eutectic beta Ti-Fe-Nb-Sn composite for implants

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    [EN] High mechanical strength (1800¿2500 MPa), elastic modulus (50¿110 GPa) close to that of human bone and good corrosion resistance are some characteristics of ultrafine eutectic Ti-based nanocomposite alloys. This is explained due to a combination of soft ß-Ti (bcc) matrix and hard/refined TiFe and/or Ti3Sn intermetallic particles. The present study focuses on the production and characterization of Ti-Fe-Nb-Sn eutectic alloys using biocompatible ß-stabilizer elements, such as Nb, Fe and Sn. Different fabrication techniques based on rapid solidification may be highlighted considering the application of these alloys as implant materials. In the present investigation, the processing routes comprise single tracks and coatings (overlapped tracks) by laser melting of pre-alloyed powders of the Ti66Fe20Nb8Sn6 alloy deposited into a Ti substrate. To select this composition (i.e., the Ti66Fe20Nb8Sn6 alloy), three Ti-Fe-Nb based chemistries (Ti63Fe23Nb8Sn6, Ti60Fe23Nb8Sn9 and Ti66Fe20Nb8Sn6) were originally generated under bulk conditions by using a suction casting apparatus. These alloys were further evaluated. All samples were analyzed by metallography, X-ray diffraction (XRD), scanning electron microscopy (SEM-EBSD and SEM-EDS), microhardness, nanohardness and elastic modulus. The results showed that the proportions of the formed TiFe and Ti3Sn intermetallic particles dispersed within the soft ß-Ti matrix play a fundamental role on the final properties. Lower elastic modulus (E ~72 GPa) is associated with the Ti66Fe20Nb8Sn6 bulk alloy. The laser clad coatings showed a broad range of nanohardness (4.8¿8.0 GPa) and elastic modulus (98¿150 GPa) depending on the related laser power and scanning speeds.The authors acknowledge the financial supports provided by CNPq (National Council for Scientific and Technological Development - Universal Project # 473777/2011-8) and by FAPESP (Sao Paulo State Research Foundation - Thematic Project # 2013/05987-8). Furthermore, we are grateful for the Grants (#2015/17090-8 - BEPE of A.L.V. and # 2015/19978-6 - BPE of C.R.M.A.) provided by FAPESP.Afonso, CRM.; Vidilli, AL.; Spinelli, JE.; Riva, R.; Amigó, V.; Kiminami, CS. (2017). An assessment of microstructure and properties of laser clad coatings of ultrafine eutectic beta Ti-Fe-Nb-Sn composite for implants. Surface and Coatings Technology. 328:161-171. https://doi.org/10.1016/j.surfcoat.2017.08.035S16117132

    Developement of real time diagnostics and feedback algorithms for JET in view of the next step

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    Real time control of many plasma parameters will be an essential aspect in the development of reliable high performance operation of Next Step Tokamaks. The main prerequisites for any feedback scheme are the precise real-time determination of the quantities to be controlled, requiring top quality and highly reliable diagnostics, and the availability of robust control algorithms. A new set of real time diagnostics was recently implemented on JET to prove the feasibility of determining, with high accuracy and time resolution, the most important plasma quantities. With regard to feedback algorithms, new model–based controllers were developed to allow a more robust control of several plasma parameters. Both diagnostics and algorithms were successfully used in several experiments, ranging from H-mode plasmas to configuration with ITBs. Since elaboration of computationally heavy measurements is often required, significant attention was devoted to non-algorithmic methods like Digital or Cellular Neural/Nonlinear Networks. The real time hardware and software adopted architectures are also described with particular attention to their relevance to ITER.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

    Nutritional management and follow up of infants and children with food allergy: Italian Society of Pediatric Nutrition/Italian Society of Pediatric Allergy and Immunology Task Force Position Statement.

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    Although the guidelines on the diagnosis and treatment of food allergy recognize the role of nutrition, there is few literature on the practical issues concerning the nutritional management of children with food allergies. This Consensus Position Statement focuses on the nutritional management and follow-up of infants and children with food allergy.It provides practical advices for the management of children on exclusion diet and it represents an evidence-based consensus on nutritional intervention and follow-up of infants and children with food allergy. Children with food allergies have poor growth compared to non-affected subjects directly proportional to the quantity of foods excluded and the duration of the diet. Nutritional intervention, if properly planned and properly monitored, has proven to be an effective mean to substantiate a recovery in growth. Nutritional intervention depends on the subject's nutritional status at the time of the diagnosis. The assessment of the nutritional status of children with food allergies should follow a diagnostic pathway that involves a series of successive steps, beginning from the collection of a detailed diet-history. It is essential that children following an exclusion diet are followed up regularly. The periodic re-evaluation of the child is needed to assess the nutritional needs, changing with the age, and the compliance to the diet. The follow- up plan should be established on the basis of the age of the child and following the growth pattern
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