1,402 research outputs found

    Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI)

    Get PDF
    [EN] This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensorThe authors are indebted to the support received from MINECO for the project MODEXFLAT ENE2013-48565-C2-1-P and ENE2013-48565-C2-2-P.Muñoz-Cobo, JL.; Chiva, S.; Mendez, S.; Monrós, G.; Escrivá, A.; Cuadros-Orón, JL. (2017). Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI). Sensors. 17(5):1-35. https://doi.org/10.3390/s17051077S13517

    IAA : Información y actualidad astronómica (22)

    Get PDF
    Sumario : Estrellas binarias: un matrimonio muy ventajoso.-- Mujeres y ciencia: rompiendo techos.-- La estrella más masiva.-- DECONSTRUCCIÓN Y otros ENSAYOS : Criterios termodinámicos en la evolución de agujeros negros.-- ACTUALIDAD.-- ENTRE BASTIDORES.-- CIENCIA: PILARES E INCERTIDUMBRES. Núcleos de galaxias activas .-- HISTORIAS DE ASTRONOMÍA: “Serendipia” cósmica.-- El increíble y asombroso viaje de Fotón. II Parte.-- ACTIVIDADES IAA.Esta revista se publica con la ayuda de la Acción Complementaria CCT005-06-00178 del Programa Nacional de Fomento de la Cultura Científica y Tecnológica.N

    PPARGC1A gene promoter methylation as a biomarker of insulin secretion and sensitivity in response to glucose challenges

    Get PDF
    Methylation in CpG sites of the PPARGC1A gene (encoding PGC1-α) has been associated with adiposity, insulin secretion/sensitivity indexes and type 2 diabetes. We assessed the association between the methylation profile of the PPARGC1A gene promoter gene in leukocytes with insulin secretion/sensitivity indexes in normoglycemic women. A standard oral glucose tolerance test (OGTT) and an abbreviated version of the intravenous glucose tolerance test (IVGTT) were carried out in n = 57 Chilean nondiabetic women with measurements of plasma glucose, insulin, and C-peptide. Bisulfite-treated DNA from leukocytes was evaluated for methylation levels in six CpG sites of the proximal promoter of the PPARGC1A gene by pyrosequencing (positions -816, -783, -652, -617, -521 and -515). A strong correlation between the DNA methylation percentage of different CpG sites of the PPARGC1A promoter in leukocytes was found, suggesting an integrated epigenetic control of this region. We found a positive association between the methylation levels of the CpG site -783 with the insulin sensitivity Matsuda composite index (rho = 0.31; p = 0.02) derived from the OGTT. The CpG hypomethylation in the promoter position -783 of the PPARGC1A gene in leukocytes may represent a biomarker of reduced insulin sensitivity after the ingestion of glucose

    Changing material around (2060) Chiron revealed by an occultation on December 15, 2022

    Get PDF
    Full list of authors: Ortiz, J. L.; Pereira, C. L.; Sicardy, B.; Braga-Ribas, F.; Takey, A.; Fouad, A. M.; Shaker, A. A.; Kaspi, S.; Brosch, N.; Kretlow, M.; Leiva, R.; Desmars, J.; Morgado, B. E.; Morales, N.; Vara-Lubiano, M.; Santos-Sanz, P.; Fernández-Valenzuela, E.; Souami, D.; Duffard, R.; Rommel, F. L.; Kilic, Y.; Erece, O.; Koseoglu, D.; Ege, E.; Morales, R.; Alvarez-Candal, A.; Rizos, J. L.; Gómez-Limón, J. M.; Assafin, M.; Vieira-Martins, R.; Gomes-Júnior, A. R.; Camargo, J. I. B.; Lecacheux, J.We were able to accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on December 15, 2022. The Kottamia Astronomical Observatory in Egypt did not detect the occultation by the solid body, but we found three extinction features in the light curve that had symmetrical counterparts with respect to the central time of the occultation. One of the features is broad and shallow, whereas the other two features are sharper, with a maximum extinction of ∼25% at the achieved spatial resolution of 19 km per data point. From the Wise Observatory in Israel, we detected the occultation caused by the main body and several extinction features surrounding the body. When all the secondary features are plotted in the sky plane, we find that they can be caused by a broad ∼580 km disk with concentrations at radii of 325 ± 16 km and 423 ± 11 km surrounding Chiron. At least one of these structures appears to be outside the Roche limit. The ecliptic coordinates of the pole of the disk are λ = 151° ±8 and β = 18° ±11, in agreement with previous results. We also reveal our long-term photometry results, indicating that Chiron had suffered a brightness outburst of at least 0.6 mag between March and September 2021 and that Chiron was still somewhat brighter at the occultation date than at its nominal pre-outburst phase. The outermost extinction features might be consistent with a bound or temporarily bound structure associated with the brightness increase. However, the nature of the brightness outburst is unclear, and it is also unclear whether the dust or ice released in the outburst could be feeding a putative ring structure or whether it is emanating from it. © The Authors 2023.Part of this work was supported by the Spanish projects PID2020-112789GB-I00 from AEI and Proyecto de Excelencia de la Junta de Andalucia PY20-01309. Financial support from the grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033 is also acknowledged. This research is partly based on observations taken with the 1.88-m telescope at the Kottamia Astronomical Observatory (KAO), operated by researchers at the National Research Institute of Astronomy and Geophysics (NRIAG), Egypt. The Egyptian team acknowledges support from Science, Technology & amp; Innovation Funding Authority (STDF) under grant number 45779. C.L.P is thankful for the support of the CAPES and FAPERJ/DSC-10 (E26/204.141/2022)

    II Jornadas de la Sociedad Española para la Conservación y Estudio de Los Mamíferos (SECEM) Soria 7-9 diciembre 1995

    Get PDF
    Seguimiento de una reintroducción de corzo (Capreolus capreolus) en ambiente mediterráneo. Dispersión y área de campeoModelos de distribución de los insectívoros ern la Península IbéricaDieta anual del zorro, Vulpes vulpes, en dos hábitats del Parque Nacional de DoñanaDesarrollo juvenil del cráneo en las poblaciones ibéricas de gato montés, Felis silvestris Schreber, 1777Presencia y expansión del visón americano (Mustela vison) en las provincias de Teruel y Castellón (Este de España).Preferencias de hábitat invernal de la musaraña común (Crocidura russula) en un encinar fragmentado de la submeseta norteUso de cámaras automáticas para la recogida de información faunística.Dieta del lobo en dos zonas de Asturias (España) que difieren en carga ganadera.Consumo de frutos y dispersión de semillas de serbal (Sorbus aucuparia L.) por zorros y martas en la cordillera Cantábrica occidentalEvaluación de espermatozoides obtenidos postmorten en el ciervo.Frecuencia de aparición de diferentes restos de conejo en excrementos de lince y zorroAtlas preliminar de los mamíferos de Soria (España)Censo y distribución de la marmota alpina (Marmota marmota) en Navarra.Trampeo fotográfico del género Martes en el Parque Nacional de Aigüestortes i Estany de Sant Maurici (Lleida)Peer reviewe

    Improved X-ray detection and particle identification with avalanche photodiodes

    Full text link
    Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2, and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g. to distinguish between x-rays and MeV electrons in our experiment.Comment: 6 pages, 6 figure

    Circulating citric acid cycle metabolites and risk of cardiovascular disease in the PREDIMED study

    Get PDF
    Background and aim Plasma citric acid cycle (CAC) metabolites might be likely related to cardiovascular disease (CVD). However, studies assessing the longitudinal associations between circulating CAC-related metabolites and CVD risk are lacking. The aim of this study was to evaluate the association of baseline and 1-year levels of plasma CAC-related metabolites with CVD incidence (a composite of myocardial infarction, stroke or cardiovascular death), and their interaction with Mediterranean diet interventions. Methods and results Case-cohort study from the PREDIMED trial involving participants aged 55–80 years at high cardiovascular risk, allocated to MedDiets or control diet. A subcohort of 791 participants was selected at baseline, and a total of 231 cases were identified after a median follow-up of 4.8 years. Nine plasma CAC-related metabolites (pyruvate, lactate, citrate, aconitate, isocitrate, 2-hydroxyglutarate, fumarate, malate and succinate) were measured using liquid chromatography-tandem mass spectrometry. Weighted Cox multiple regression was used to calculate hazard ratios (HRs). Baseline fasting plasma levels of 3 metabolites were associated with higher CVD risk, with HRs (for each standard deviation, 1-SD) of 1.46 (95%CI:1.20–1.78) for 2-hydroxyglutarate, 1.33 (95%CI:1.12–1.58) for fumarate and 1.47 (95%CI:1.21–1.78) for malate (p of linear trend <0.001 for all). A higher risk of CVD was also found for a 1-SD increment of a combined score of these 3 metabolites (HR = 1.60; 95%CI: 1.32–1.94, p trend <0.001). This result was replicated using plasma measurements after one-year. No interactions were detected with the nutritional intervention. Conclusion Plasma 2-hydroxyglutarate, fumarate and malate levels were prospectively associated with increased cardiovascular risk

    Influência da variação da produtividade das usinas hidroelétricas no cálculo da energia firme

    Get PDF
    In the present work, the problem associated to the firm energy evaluation is treated as a non linear optimization model, which allows the representation of the productivity variation of the hydro plants. The proposed model takes into account the individualized representation of the plants and the historical series of flows since the month of January of 1931. The proposed optimization problem will be solved using the Primal-Dual Interior Point Method. A case study will be presented including the Brazilian Interconnected National System. The results obtained show that the proposed methodology is promising, since it presents an energy market value more realistic when compared with existing methodologies.No presente trabalho, o problema associado ao cálculo da energia firme é tratado como um modelo não linear de otimização, o que permite a representação da variação da produtividade das usinas. No modelo proposto é considerada a representação individualizada das usinas bem como a série histórica de vazões desde o mês de janeiro de 1931. O problema de otimização proposto é resolvido através do método primal-dual de pontos interiores. Adicionalmente, é apresentado um estudo de caso abrangendo o Sistema Interligado Nacional Brasileiro. Os resultados obtidos mostram que a metodologia proposta é promissora, tendo em vista que apresenta um valor de mercado de energia mais realista quando comparado com outras metodologias

    Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

    Get PDF
    Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population.This work was supported in part by the Spanish AIDS Research Network (RD16/0025/0017, RD16/0025/0018), which is included in the Spanish I+D+I Plan and is co-funded by the ISCIII-Subdirección General de Evaluación and European Funding for Regional Development (FEDER). The sponsors had no role in the study design, the collection, analysis and interpretation of data, the writing of the report, or the decision to submit the article for publication.S

    The stellar occultation by (319) Leona on 2023 September 13 in preparation for the occultation of Betelgeuse

    Get PDF
    J. L. Ortiz et al.On 2023 December 12, the star α Orionis will be occulted by asteroid (319) Leona. This represents an extraordinary and unique opportunity to analyse the brightness distribution of Betelgeuse’s photosphere with extreme angular resolution by studying light curves from different points on Earth and at different wavelengths. Here we present observations of another occultation by asteroid Leona, on 2023 September 13, whose goal was to determine Leona’s projected shape and size in preparation for the December 12th event and its interpretation. The occultation campaign was highly successful with 25 positive detections from 17 different sites and a near miss. The effective diameter in projected area derived from the positive detections was 66 ± 2 km using an elliptical fit to the instantaneous limb. The body is highly elongated, with dimensions of 79.6 ± 2.2 km × 54.8 ± 1.3 km in its long and short axis, respectively, at occultation time. This result, in combination with dense time series photometry of Leona that we recently obtained, together with archival sparse photometry, allowed us to predict the angular size of the asteroid for the Betelgeuse event and to simulate the expected brightness change. Also, an accurate position coming from the occultation is provided, to improve the orbit of Leona.Part of this work was supported by the Spanish projects PID2020-112789GB-I00 from AEI and Proyecto de Excelencia de la Junta de Andalucía PY20-01309. Financial support from the grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/501100011033 is also acknowledged. MS-G acknowledges the financial support from the Planetary Society via its ‘2023 Gene Shoemaker NEO Grant’. JM and PLLE are supported by grant PID2019-105510GB-C32/AEI/10.13039/501100011033 from the State Agency for Research of the Spanish Ministry of Science and Innovation. They also acknowledge support by Consejería de Economía, Innovación, Ciencia y Empleo of Junta de Andalucía as research group FQM- 322, as well as FEDER funds. PS-S acknowledges financial support from the Spanish I+D + i project PID2022-139555NB-I00 funded by MCIN/AEI/10.13039/501100011033. JLR acknowledges financial support by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR. We thank M. Pugnaire for observing support at Los Coloraos observatory. AR and SA acknowledge the financial support through the Europlanet Society Public Engagement Funding Scheme 2023, sponsored by the ‘Dill Faulkes Educational Trust’. This article is partly based on observations made in the Observatorios de Canarias of IAC with the Liverpool Telescope operated on the island of La Palma by the Liverpool JMU in the Observatorio del Roque de los Muchachos. This article includes observations made in the Two-metre Twin Telescope (TTT) in the Teide Observatory of the IAC, that Light Bridges operates in the Island of Tenerife, Canary Islands (Spain). The Observing Time Rights (DTO) used for this research were provided by IAC. This article includes observations made with TRAPPIST telescopes. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant PDR T.0120.21. TRAPPIST-North is a project funded by the University of Liége, in collaboration with the Cadi Ayyad University of Marrakech (Morocco). EJ is a F.R.S.-FNRS Senior Research Associate. FLR thanks the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo) granted by CNPq grant number 465376/2014-2. PJG acknowledges financial support from project PID2021-126365NB-C21 (MCI/AEI/FEDER, UE).With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).Peer reviewe
    corecore