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Search Results: 1 - 10 of 11814 matches for " Rafael Carretero "
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TM-TE Decomposition of Power Losses in Multi-Stranded Litz-Wires Used in Electronic Devices
Claudio Carretero;Jesus Acero;Rafael Alonso
PIER , 2012, DOI: 10.2528/PIER11091909
Abstract: Efficiency often constitutes the main goal in the design of a power system because the minimization of power losses in the magnetic components implies better and safer working conditions. The primary source of losses in a magnetic power component is usually associated with the current driven by the wire, which ranges from low to medium frequencies. New power system tendencies involve increasing working frequencies in order to reduce the size of devices, thus reducing costs. However, optimal design procedures involve increasingly complex solutions for improving system performance. For instance, using litz-type multi-stranded wires which have an internal structure to uniformly share the current between electrically equivalent strands, reducing the total power losses in the windings. The power losses in multi-stranded wires are generally classified into conduction losses and proximity losses due to currents induced by a magnetic field external to the strand. Both sources of loss have usually been analyzed independently, assuming certain conditions in order to simplify the derivation of expressions for calculating the correct values. In this paper, a unified analysis is performed given that both power losses are originated by the electromagnetic fields arising from external sources where the wire is immersed applying the decomposition into transversal magnetic (TM) and transversal electric (TE) components. The classical power losses, the so called conduction and proximity losses, can be calculated considering the TM modes under certain conditions. In addition, a new proximity loss contribution emerges from the TE modes under similar conditions.
Coupling Impedance Between Planar Coils Inside a Layered Media
Claudio Carretero;Rafael Alonso;Jesus Acero;Jose Miguel Burdio
PIER , 2011, DOI: 10.2528/PIER10112911
Abstract: In this paper a semi-analytical representation of the coupling impedance between coils composed of filamentary turns located between two layered media is provided on the basis of the spectral expansion of the fields involved in the system. Both media are composed of several layers of homogeneous materials characterized by their physical properties occupying, respectively, a half-space bounded by a plane. The domain in the middle, where the coils are placed, has vacuum properties. The development is focused on misaligned circular coils placed in parallel planes with respect to the media boundaries. Two different behavioral descriptions have been considered: first, the system is made up entirely of magnetic insulators and the coupling impedance is therefore purely inductive; second, at least one medium is an electrical conductor and, as a consequence, an additional resistive component emerges when the coupling impedance is evaluated. In the latter case, the coupling impedance exhibits a frequency dependence due to the dispersive effects associated with the induced currents generated in the conductive media. The model developed is verified by means of a comparison between numerical and experimental results.
Nota de libros
Cuesta ávila, Rafael A.,Jiménez-Esquinas, Guadalupe,Sánchez-Carretero, Cristina,Arrieta Urtizberea, I?aki
Revista de Dialectología y Tradiciones Populares , 2011,
Abstract:
Reacciones a la modernidad. Una lectura de las respuestas de lo social al ejercicio del poder
Enrique Carretero
Nómadas , 2003,
Abstract:
Maurice Halbwachs: Official and hidden memory
Carretero, Angel
Athenea Digital , 2008,
Abstract: This article tries to show, in general terms, how Maurice Halbwachs has discovered presence and vitality in the collective memorieswhich have been excluded from the socially-institutionalized world. In order to decipher his opaque writing, one should try for a sociology of the depths, for a sociological look that, separating itself from the dominant positivism of the social sciences, manages to penetrate the hidden logic that permanently underlies social life. This article seeks to uncover the nature of a collective memory that respects the vicissitudes of time, as well as its difficult relations both with official memory and with the dominant historical record.
Phytogenic Mounds (Nebkhas): Effect of Tricomaria usillo on Sand Entrapment in Central-West of Argentina  [PDF]
Graciela Pastrán, Eduardo Martínez Carretero
Journal of Geographic Information System (JGIS) , 2016, DOI: 10.4236/jgis.2016.84036
Abstract: Nebkhas, developed by the trapping of sand within the body of a plant, were studied in the Médanos Grandes system, arid central Argentina, during the springs of 2009-2010. The dynamics of nebkhas was studied in three draas (megadunes), and considering both orientations: leeward and windward. The Drift Potential (DP) for the study area was 42, evidencing the inactivity of the sand dunes or the scarce activity only in crests. Dominant sand movement is in south-southeast direction, with deflation processes at the southern side of the nebkhas. All nebkhas showed uniformity in the morphometry. Tricomaria usillo is the dominant plant species in the nebkha formation process; and results showed a significant positive relationship between nebkha and canopy volumes.
Genetic polymorphisms of RANTES, IL1-A, MCP-1 and TNF-A genes in patients with prostate cancer
Pablo Sáenz-López, Rafael Carretero, José Cózar, José Romero, Julia Canton, José Vilchez, Miguel Tallada, Federico Garrido, Francisco Ruiz-Cabello
BMC Cancer , 2008, DOI: 10.1186/1471-2407-8-382
Abstract: A case-control study design was used to test the association between prostate cancer risk and the polymorphisms TNF-A-308 A/G (rs 1800629), RANTES-403 G/A (rs 2107538), IL1-A-889 C/T (rs 1800587) and MCP-1 2518 G/A (rs 1024611) in 296 patients diagnosed with prostate cancer and in 311 healthy controls from the same area.Diagnosis of prostate cancer was significantly associated with TNF-A GA + AA genotype (OR, 1.61; 95% CI, 1.09–2.64) and RANTES GA + AA genotype (OR, 1.44; 95% CI, 1.09–2.38). A alleles in TNF-A and RANTES influenced prostate cancer susceptibility and acted independently of each other in these subjects. No epistatic effect was found for the combination of different polymorphisms studied. Finally, no overall association was found between prostate cancer risk and IL1-A or MCP-1 polymorphisms.Our results and previously published findings on genes associated with innate immunity support the hypothesis that polymorphisms in proinflammatory genes may be important in prostate cancer development.Chronic or recurrent inflammation is known to play a causative role in the promotion and progression of many human tumours, including cancers of the liver, oesophagus, stomach, large intestine and urinary bladder [1-3]. Chronic inflammation has also been implicated in the aetiology of prostate cancer [4-7]. Prostate cancer risk has been associated with sexually transmitted infections and prostatitis in some epidemiologic studies [8,9], and its relationship with genetic polymorphisms in inflammatory cytokines has been explored in various case-control studies [10-13]. Chronic inflammation, alongside the intrinsic properties of pre-malignant cells and other determinants, may therefore be one of the driving forces of malignant transformation. Thus, numerous mediators released in dysregulated chronic inflammation have been found to promote cell growth and invasion, induce mutagenesis and increase angiogenicity [1]. By virtue of these properties, inflammatory mediators favo
Polimorfimos en genes de respuesta inflamatoria en cáncer renal metastásico
Sáenz López,Pablo; Vázquez Alonso,Fernando; Romero,José M.; Carretero,Rafael; Tallada Bu?uel,Miguel; Ruiz Cabello,Francisco; Cózar Olmo,José Manuel;
Actas Urológicas Espa?olas , 2009, DOI: 10.4321/S0210-48062009000500004
Abstract: inflammation has been implicated as an etiological factor in different human cancers. allelic variations in the genes implicated in inflammation are candidates as genetic determinants or markers of renal carcinoma risk. the present study investigates whether polymorphisms of the genes that give rise to increases in the levels of proinflammatory cytokines and chemokines are associated with an increased risk of renal carcinoma. to this effect, a number of case-control studies were designed to assess the correlation between renal carcinoma and polymorphisms il10-1082 a/g (rs 1800896), il10-592 a/c (rs 1800872), il10-819 c/t (rs 1800871), il10-1082 a/g, il4-590 c/t (rs 2243250), tnf-a-308 a/g (rs 1800629), rantes-403 g/a (rs 2107538), il1-a-889 c/t (rs 1800587), mcp-1 2518 g/a (rs 1024611), ctla-4/+49 a/g (rs 231775) and ctla-4 ct60 a/g (rs 3087243) in 127 renal carcinoma patients and in 176 healthy subjects. the results obtained in relation to cytokine polymorphism il-10-1082 a/g indicate that ag heterozygosity status is the principal risk factor in relation to locally advanced or metastatic tumor stage and renal carcinoma. in the case of the molecule ctla4, the results obtained in renal cancer reveal an association between the polymorphisms of the ctla-4 gene and an increased risk of developing renal cell carcinoma. a high genotypic frequency of polymorphisms ctla4/ct60-aa and ctla4/a49g-aa is observed in patients with renal cell carcinoma versus the controls. an association has been established between polymorphism ctla4/ct60 and tumor grade in patients with renal cell carcinoma. logistic regression analysis has confirmed these data, demonstrating a high frequency of the aa genotype in patients with high-grade tumors. the results obtained support the hypothesis that different genetic factors implicated in the regulation of adaptive immune responses, stromal cell composition and local cytokine production levels may be crucial elements in the modification of the clinic
La colectoría de Espa?a en época de Carlos V: cuentas del nuncio y colector General Giovanni Poggio (1529-1546)
Carretero Zamora,Juan M.;
Cuadernos de historia de Espa?±a , 2003,
Abstract: the "colectorías"; were basic institutions of the pope's finances. there was a "colectoría"; in each european catholic kingdom, chiefs of which were those belonging to the habsburg monarchy: spain, naples and portugal. the most important was the spanish "colectoría";, which included the kingdoms of castile and aragon. this "colectoría"; reached its definitive configuration in the times of the papal nuncio in spain, giovanni poggio, an important person who held high offices in rome's finances.
Dioscorea volckmannii (Dioscoreaceae): nuevo registro para la Argentina
Martínez Carretero,Eduardo;
Darwiniana , 2011,
Abstract: dioscorea volckmannii, known until now from valparaiso to talca provinces in chile, is recorded for the first time for the argentinean flora in the province of mendoza. the species is described and illustrated, and environmental observations are included.
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