Validating GIC modeling in the Spanish power grid by differential magnetometry

series of experiences and recommendations are presented concerning the derivation of geomagnetically induced currents (GIC) by use of the differential magnetometry method (DMM) under power lines. This indirect technique, intended to obtain observations to validate GIC models, is an alternative to measuring the current flow in the transformer neutrals. It is a non-intrusive and autonomous technique, as the procedure does not depend on the grid operator. In contrast, the selection of suitable sites devoid of human interferences, the need for power to supply the magnetometer, the data acquisition and transmission system, along with the choice of the appropriate instrumentation are difficulties that make not just any site suitable for installation and often require costly solutions. We focus on the methodology followed to estimate the GIC flowing in several transmission lines of the Spanish power grid with the aim of validating our GIC models, and we share our experience on the installation of the measuring points. Uncertainty inherent in the DMM is assessed, showing that noise is the main handicap, although it can be minimized with appropriate filtering. According to such experience, on some occasions only total DC currents above a significant fraction of 1 A give magnetic signatures well above the noise level, so this figure can roughly be considered as the threshold limit for detection. The low solar activity, combined with the mid-latitude condition of Spain, limited the significance of available recorded data, but we can already report and analyze the results for several minor geomagnetic storms

Probing the near infrared stellar population of Seyfert galaxies

We employ IRTF SpeX NIR (0.8-2.4 microns) spectra to investigate the stellar population (SP), active galactic nuclei (AGN) featureless continuum (FC) and hot dust properties in 9 Sy 1 and 15 Sy 2 galaxies. Both the starlight code and the hot dust as an additional base element were used for the first time in this spectral range. We found evidence of correlation among the equivalent widths (W) Si I 1.59 microns x Mg I 1.58 microns, equally for both kinds of activity. Part of the W{Na I 2.21 microns} and W {CO 2.3 microns} strengths may be related to galaxy inclination. Our synthesis shows significant differences between Sy 1 and Sy 2 galaxies: the hot dust component is required to fit the K-band spectra of ~90% of the Sy 1 galaxies, and only of ~25% of the Sy 2; about 50 % of the Sy 2 galaxies require a $FC$ component contribution >20%, while this fraction increases to 60% in the Sy 1; also, in about 50 % of the Sy2, the combined FC and young components contribute with more than 20%, while this occurs in 90% of the Sy1, suggesting recent star formation in the central region. The central few hundred parsecs of our galaxy sample contain a substantial fraction of intermediate-age SPs with a mean metallicity near solar. Our SP synthesis confirms that the 1.1 micron CN band can be used as a tracer of intermediate-age SPs. The simultaneous fitting of SP, FC and hot dust components increased in ~150% the number of AGNs with hot dust detected and the mass estimated. The NIR emerges as an excellent window to study the stellar population of Sy 1 galaxies, as opposed to the usually heavily attenuated optical range. Our approach opens a new way to investigate and quantify the individual contribution of the three most important NIR continuum components observed in AGNs.Comment: The paper contains 14 figures and 5 tables. Accepted for publication in MNRA

Prótesis total de cadera con doble recubrimiento de porometal e hidroxiapatita: resultados preliminares

El objetivo de este trabajo es evaluar la eficacia de la prótesis con superficie de Poropatita, recubrimiento doble de Poropros e Hidroxiapatita, para su fijación ósea directa en el reemplazo total de cadera. El estudio ha sido llevado a cabo en 80 pacientes con un seguimiento mínimo de 3 años. La valoración clínica se ha realizado según el sistema de Harris modificado, obteniendo un 90% de buenos resultados y un 10% de resultados regulares en la serie estudiada. El análisis, revisado a partir de parámetros clínicos y radiográficos, permite apreciar que el recubrimiento de un metal poroso con hidroxiapatita supone un mecanismo de seguridad en la fijación primaria como secundaria del implante. La estabilidad inmediata del componente femoral y cotiloideo, factor importante en la osteointegración del implante.This study was aimed at evaluating the outcome in terms of primary bone fixation of a total hip prosthesis coated with Poropatita® , o double coating of porous-metal and hidroxyapatite. The study reviews 80 patients operated on with a minimum follow-up of 3 years. A modified Harris score was used for clinical assessment. Good clinical results wer obtained in 9 0% of patients, while 10% achieved a fair outcome. Based on clinical and radiographic parameters, porous-metal and hidroxyapatite double coating provides both excellent primary and secondary bone fixation of the prosthetic components. Primary stability of both femoral stem and cup seens to be an important factor for osteointegration of the implant

La artroscopia de rodilla: experiencia de 474 casos

El objetivo de este trabajo es dar a conocer los resultados de un estudio de 474 artroscopias realizadas en nuestro Servicio de Cirugía Ortopédica y Traumatología desde el mes de enero 1988 hasta agosto 1992. La edad media de los pacientes fue de 32 años, con una mayor incidencia en el sexo masculino (73%). La patología más frecuente correspondió a la meniscopatía interna (48%). Tuvimos una estancia media hospitalaria de 3 días, apreciándose una relación inversa entre ésta y la edad del paciente. La complicación más habitual en el post-operatorio fue el derrame sinovial (3%) siendo necesaria al artrocentesis para su desaparición en el plazo de 1-2 semanas.This work was aimed at presenting the results of 474 diagnostic artroscopies of the knee performed in our Department of orthopaedic surgery from January 1988 to August 1992. The mean age of the patients was 32 years. There was a greater incidence in males (73%). The most frequent pathologic finding was medial meniscopathy (48%). The mean period of hospitalization was 3 days. There was an opposite relationship betwen the hospitalization period and the age of the patient. As complications, synovial effusion was found in 3% of cases, synovial fluid evacuation been necessary

Germinação de semente, embrião e eixo embrionário de sucupira branca (Pterodon pubescens Benth.) in vitro.

Resumo de trabalho apresentado no 7º Congresso Brasileiro de Fisiologia Vegetal, Brasília, julho 1999

Estabelecimento e multiplicação in vitro de segmento nodal de Sucupira branca (Pterodon pubescens Benth.).

Resumo de trabalho apresentado no 7º Congresso Brasileiro de Fisiologia Vegetal, Brasília, julho 1999

La prótesis de cadera con recubrimiento de vidrio Primeros resultados con 2 años de evolución

El presente trabajo analiza los primeros resultados clínicos y radiográficos de un estudio con la prótesis de cadera no cementada con recubrimiento «de vidrio» a nivel metafísario (prótesis CRM). La casuística comprende 80 artroplastias totales implantadas desde 1991 a 1994 con un seguimiento mínimo de 2 años. La evolución clínica, valorada según el sistema de Harris modificado, ha sido satisfactoria en el 90% de los enfermos. La observación radiográfica ha mostrado buena fijación y orientación de los componentes femorales en 72 casos. La conclusión de este análisis preliminar permite apreciar que el recubrimiento protésico con cerámica de vidrio supone un mecanismo de seguridad en la fijación primaria y secundaria de la prótesis de cadera.This work analizes the first clinical and radiological results of a cementless hip prosthesis with glass coating at metaphyseal level (CRM prosthesis). A total of 80 arthroplasties implanted since may 1991 to 1994 were studied with a two year follow-up. The clinical assesment was done by the modified Harris score, being satisfactory in 90% of the patients. The radiological study demonstrated good fixation and orientation of the prosthetic compounds in 72 cases. The prosthetic model studied provides a security mechanism both for primary and secondary fixation of the femoral stem and acetabular cup

Hubble Space Telescope WFPC-2 Imaging of Cassiopeia A

The young SNR Cassiopeia A was imaged with WFPC-2 through four filters selected to capture the complete velocity range of the remnant's main shell in several important emission lines. Primary lines detected were [O III] 4959,5007, [N II] 6583, [S II] 6716,6731 + [O II] 7319,7330 + [O I] 6300,6364, and [S III] 9069,9532. About 3/4th of the remnant's main shell was imaged in all four filters. Considerable detail is observed in the reverse-shocked ejecta with typical knot scale lengths of 0.2"-0.4" (1 - 2 x 10^16 cm). Both bright and faint emission features appear highly clumped. Large differences in [S III] and [O III] line intensities indicating chemical abundance differences are also seen, particularly in knots located along the bright northern limb and near the base of the northeast jet. A line of curved overlapping filament in the remnant's northwestern rim appears to mark the location of the remnant's reverse shock front in this region. Finger-like ejecta structures elsewhere suggest cases where the reverse shock front is encountering the remnant's clumped ejecta. Narrow-band [N II] images of the remnant's circumstellar knots ("QSFs") reveal them to be 0.1"-0.6" thick knots and filaments, often with diffuse edges facing away from the center of expansion. Three color composite images of the whole remnant and certain sections along with individual filter enlargements of selected regions of the bright optical shell are presented and discussed.Comment: 26 pages, 12 figures Accepted to the Astronomical Journa