Comportamiento productivo de los rebaños de cría de bovinos en el Valle del Cauto, Cuba

The productive behavior of bovine breeding herds from 27 farms located in a low basin of Cauto River in Las Tunas province, Cuba, was studied during a four-year period of time. In order to evaluate the already existing productive systems, the following indexes were analyzed: herd management, herd feeding, and some other aspects related to handling. Variables from production efficiency, handling conditions, as well as processes and procedures defining technological alternatives applied to the farms were checked over. Multivariational statistical techniques of principal components were used to define a number of factors which de- termine the productive behavior of herds, taken as the production of liveweight/breeder/year. Besides, a hierarchical analysis of the farms was carried out as to characterize them all. According to the evaluated indexes, farms were divided into three groups: I. Farms having a complete artificial insemination where management procedures guaranteeing a decrease in post-calving anestrus were applied and a load adjustment to real herd capacity was performed; II. Herds raised in open ranges, and III. The remaining farms with a complete artificial insemination. Farms from groups I and II attained a higher productive efficiency, which demon- strates that such efficiency depends on production and reproduction planning and these systems load capacity.Se caracterizó durante cuatro años el comportamiento productivo de los rebaños de cría de bovinos de 27 fincas ubicadas en la cuenca baja del río Cauto, en la provincia Las Tunas, Cuba. Para la evaluación de los sistemas productivos se tomaron en conside- ración los indicadores siguientes: el manejo de los rebaños, la alimentación y otros aspectos de las condiciones de tenencia. Se controlaron las variables correspondientes a la eficiencia de la producción, condiciones de tenencia y a los procesos y procedi- mientos que definen las alternativas tecnológicas utilizadas en las fincas estudiadas. Se emplearon las técnicas estadísticas multi- variadas componentes principales para definir los factores que determinan el comportamiento productivo de los rebaños, medida como la producción de peso vivo/reproductora/año y el análisis de conglomerado jerárquico para tipificar las fincas. Según los indicadores evaluados se determinaron tres grupos: de las fincas en I. A. completo, donde se aplicaron procedimientos de manejo que garantizan la disminución del anestro postparto y se ajustó la carga a la capacidad de carga del sistema pastoril; los rebaños en patios y el resto de las fincas en IA. completo. En las fincas de los grupos I y II se logra la mayor eficiencia productiva, demos- trándose que está determinada por organización de la producción, y la reproducción y por la capacidad de carga de estos sistemas

Methodology of fault diagnosis for grid-connected photovoltaic systems of network connection

[ES] Esta investigación tiene como objetivo el diseño de una metodología de diagnóstico de fallos para contribuir al mejoramiento de los indicadores de eficiencia, mantenimiento y disponibilidad de los Sistemas Fotovoltaicos de Conexión a Red (SFVCR). Para lograr dicho objetivo, se realiza el estudio del inversor de conexión a red y del modelo matemático del generador fotovoltaico. Luego se cuantifican las pérdidas operacionales del generador fotovoltaico y se adapta el modelo matemático de éste a las condiciones reales del sistema a través de un ajuste polinomial. Un sistema real de conexión a red de potencia nominal 7.5 kWp, instalado en el Centro de Investigaciones de Energía Solar (CIES) en la provincia Santiago de Cuba, se utiliza para evaluar la metodología propuesta. Con los resultados obtenidos se valida el diseño propuesto para demostrar que éste supervisa con éxito el SFVCR. La metodología fue capaz de detectar e identificar el 100 % de los fallos simulados y los ensayos realizado[EN] The aim of the present research work is the design of a methodology of fault diagnosis as a contribution to the improvement of indicators about efficiency, maintenance and availability of Photovoltaic Systems of Network Connection (PVSNC). The network connection inverter and the mathematical model of the Photovoltaic Generator were firstly analyzed. Afterwards, the existing operational losses of the Photovoltaic Generator were quantified, and the mathematical model was adapted to the real conditions of the System through a polynomial adjustment. A real network connection system of nominal power 7.5 kWp installed at the Research Center of Solar Energy, in the province of Santiago de Cuba, was used to assess the proposed methodology. The results obtained were validated to show that the proposed design successfully supervises the PVSNC.100% of the simulated faults were detected and identified with the designed methodology, whose usefulness was additionally shown when having a maximum rateNúñez A., J.; Benítez P., I.; Proenza Y., R.; Vázquez S., L.; Díaz M., D. (2020). Metodología de diagnóstico de fallos para sistemas fotovoltaicos de conexión a red. Revista Iberoamericana de Automática e Informática industrial. 17(1):94-105. https://doi.org/10.4995/riai.2019.11449OJS94105171Alam, M., Khan, F., Johnson, J. & Flicker, J., 2015. A comprehensive review of catastrophic faults in PV arrays: types, detection, and mitigation techniques. IEEE Journal of Photovoltaics 5(3):1-16. https://doi.org/10.1109/JPHOTOV.2015.2397599Berbesi, T. Aplicacion de técnicas robustas para detección y diagnóstico de fallos. 2012. Tesis Doctoral. Universidad de Valladolid, España.Brooks, B. The bakersfield fire: a lesson in ground-fault protection. SolarPro, Issue 4.2, Feb/Mar 2011.Chao, K., Ho, S. & Wang, M. Modeling and fault diagnosis of a photovoltaic system. 2008. Electric Power Systems Research 78 (1), p. 97-105. https://doi.org/10.1016/j.epsr.2006.12.012Chouder, A. & Silvestre. Automatic supervision and fault detection of PV systems based on power losses analysis. Energy Conversion and Management, Volume 51, Issue 10, October 2010, Pages 1929-1937. https://doi.org/10.1016/j.enconman.2010.02.025Chouder, A. & Silvestre, S. Analysis model of mismatch power losses in PV systems. 2009. Journal of Solar Energy Engineering, 131(2), 024504 (Apr 02, 2009) (5 pages).https://doi.org/10.1115/1.3097275De Soto, W., Klein, W., Beckman, W. A. Improvement and Validation of a Model for Photovoltaic Array Performance. 2004. Solar Energy, 80(2), January 2006, Pages 78-88.https://doi.org/10.1016/j.solener.2005.06.010Duffie, J. A., Beckman, W. A. Solar Engineering of Thermal Processes. Fourth Edition. 2013. Published by John Wiley & Sons, Inc., Hoboken, New Jersey. https://doi.org/10.1002/9781118671603Farhat, M., Barambones, Ó., Ramos, J., Durán, E., & Andújar, J. (2015). Diseño e Implementación de un Sistema de Control estable basado en Lógica Borrosa para optimizar el rendimiento de un sistema de Generación Fotovoltaico. Revista Iberoamericana de Automática e Informática industrial, 12(4), 476-487. https://doi.org/10.1016/j.riai.2015.07.006Firth, S. K. Raising Efficiency in Photovoltaic Systems: High Resolution Monitoring and Performance Analysis. 2006 Tesis Doctoral. Institute of Energy and Sustainable Development De Montfort University.Garoudja, E., Harrou, F., Sun, Y., Kamel, K., Chouder, A., Silvestre, S. Statistical fault detection in photovoltaic systems. 2017. Solar Energy, 150(1), July 2017, Pages 485-499.https://doi.org/10.1016/j.solener.2017.04.043González, G. N., De Angelo, C. H., Forchetti, D. G., Aligia, D. A., 2018. Detection and Isolation of Faults on the Rotor Side Converter of Doubly Fed Induction Generators. Revista Iberoamericana de Automática e Informática Industrial,15(3), 297-308. ISSN: 1697-7912, https://doi.org/10.4995/riai.2017.9042Grimaldo Guerrero, J. W., Mendoza Becerra, M. A., Reyes Calle, W. P., 2017. Modelo para pronosticar la demanda de energía eléctrica utilizando los producto interno brutos sectoriales: Caso de Colombia. Revista Espacios Vol. 38 (22), 38.Guerrero, J. W. G., Toscano, A. D. R., Pacheco, L. V., Tovar, J. O., 2018. Analysis of the Energetic and Productive Effects Derived by the Installation of a Conveyor Belt in the Metal-mechanic Industry. International Journal of Energy Economics and Policy, 8(6), 196-201. https://doi.org/10.32479/ijeep.7066Houssein, N. Héraud, I. Souleiman and G. Pellet, "Monitoring and fault diagnosis of photovoltaic panels," 2010 IEEE International Energy Conference, Manama, 2010, pp. 389-394. https://doi.org/10.1109/ENERGYCON.2010.5771711Lorenzo, E., Martínez F., Muñoz, J., Narvarte, L. Predicción y ensayo de la producción de la energía FV conectada a la red. Era solar: Energías renovables, ISSN 0212-4157, Nº. 139, 2007, págs. 22-31Mekki, H., Mellit, A., Salhi & H.H. Artificial neural network-based modelling and fault detection of partial shaded photovoltaic modules. 2016. Simulation Modelling Practice and Theory, vol 67, p. 1-13. https://doi.org/10.1016/j.simpat.2016.05.005Meyer. E. L., Van Dyk, E. E. Assessing the reliability and degradation of photovoltaic module performance parameters, in IEEE Transactions on Reliability, vol. 53, no. 1, pp. 83-92, March 2004. https://doi.org/10.1109/TR.2004.824831Mikati, M., Santos, M., Armenta, C., 2013. Electric grid dependence on the configuration of a small-scale wind and solar power hybrid system. Renewable Energy, 57, 587-593. https://doi.org/10.1016/j.renene.2013.02.018Montgomery, D., 2009. Introduction to Statistical Quality Control. Sixth Edition 978-0-470-16992-6 Printed in the United States of America.Munoz, M., Alonso-García, M., Vela, N. & Chenlo, F., 2011. Early degradation of silicon pv modules and guaranty conditions. 2011. Solar Energy 85(9):2264-2274. https://doi.org/10.1016/j.solener.2011.06.011Real Calvo, R., Moreno Muñoz, A., Pallares López, V., González Redondo, M., Moreno García, I., & Palacios García, E. (2017). Sistema Electrónico Inteligente para el Control de la Interconexión entre Equipamiento de Generación Distribuida y la Red Eléctrica. Revista Iberoamericana de Automática e Informática industrial, 14(1), 56-69. https://doi.org/10.1016/j.riai.2016.11.002Romera Cabrerizo, J. A., Santos, M., 2017. ParaTrough: Modelica-based Simulation Library for Solar Thermal Plants. Revista Iberoamericana de Automática e Informática Industrial, 14(4):412-423. https://doi.org/10.1016/j.riai.2017.06.005Rubio, F. R., Navas, S. J., Ollero, P., Lemos, J. M., Ortega, M. G., 2018. Optimal Control Applied to Distributed Solar Collector Fields. Revista Iberoamericana de Automática e Informática Industrial, 15(3), 327-338. https://doi.org/10.4995/riai.2018.8944Sagastume Gutiérrez, A., Cabello Eras, J.J., Hens, L,. 2017. The Biomass Based Electricity Generation Potential of the Province of Cienfuegos, Cuba. Waste Biomass Valor. 8(6), 2075-2085. https://doi.org/10.1007/s12649-016-9687-xSagastume Gutiérrez, A., Cabello Eras, J.J., Huisinghc, D., Vandecasteeled, C., Hense, L., 2018. The current potential of low-carbon economy and biomass-based electricity in Cuba. The case of sugarcane, energy cane and marabu (Dichrostachys cinerea) as biomass sources. Journal of Cleaner Production. 17(2), Pages 716-723. https://doi.org/10.1016/j.jclepro.2017.11.209Stettler, S., Toggweiler, P., Wiemken, E., Heidenreich, W., Keizer, A.C., Sark, W.G., Feige, S., Schneider, M., Heilscher, G., É., Lorenz, R., Drews, A., Heinemann, D., 2005. Failure Detection Routine for Grid Connected Pv Systems as Part of the Pvsat2 Project. 20th European Photovoltaic Solar Energy Conference and Exhibition.Tian, H., Mancilla-David, F., Ellis, K., Muljadi, E., & Jenkins, P. Detailed Performance Model for Photovoltaic Systems: Preprint. United States. National Renewable Energy Laboratory, 2012 - 56 páginas.Vergura, S., Acciani, G., Amoruso, V., Patrono, G., 2008. Inferential statistics for monitoring and fault forecasting of pv plants. In Industrial Electronics IEEE International Symposium on, p. 2414-2419. https://doi.org/10.1109/ISIE.2008.4677264Vergura, S., Acciani, G., Amoruso, V., Patrono, G., Vacca, F. 2009. Descriptive and inferential statistics for supervising and monitoring the operation of pv plants. Industrial Electronics, IEEE Transactions on Energy Conversion, p. 4456-4464. https://doi.org/10.1109/TIE.2008.927404Zhao, Y., 2010. Fault analysis in solar photovoltaic arrays. Master's thesis, Northeastern University. Boston, Massachusetts. http://hdl.handle.net/2047/d20003009Zhao, Y., Ball, R., Mosesian, de Palma, J., Lehman, B. 2014. Graph-based semi-supervised learning for fault detection and classification in solar photovoltaic arrays. In IEEE Transactions on Power Electronics, vol. 30, no. 5, pp. 2848-2858, May 2015. https://doi.org/10.1109/TPEL.2014.2364203Zhao, Y., Lehman, B., Ball, R., Mosesian, J., de Palma, J. 2013 . Outlier detection rules for fault detection in solar photovoltaic arrays. In Applied Power Electronics Conference and Exposition (APEC), Twenty-Eighth Annual IEEE, p. 2913-2920. https://doi.org/10.1109/APEC.2013.6520712Zhao, Y, Yang, L., Lehman, B., de Palma, J., Mosesian, J. 2012. Decision tree-based fault detection and classification in solar photovoltaic arrays. Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC), Orlando, FL, pp. 93-99. https://doi.org/10.1109/APEC.2012.616580

Metodología de diagnóstico de fallos para sistemas fotovoltaicos de conexión a red

The aim of the present research work is the design of a methodology of fault diagnosis as a contribution to the improvement of indicators about efficiency, maintenance and availability of Photovoltaic Systems of Network Connection (PVSNC). The network connection inverter and the mathematical model of the Photovoltaic Generator were firstly analyzed. Afterwards, the existing operational losses of the Photovoltaic Generator were quantified, and the mathematical model was adapted to the real conditions of the System through a polynomial adjustment. A real network connection system of nominal power 7.5 kWp installed at the Research Center of Solar Energy, in the province of Santiago de Cuba, was used to assess the proposed methodology. The results obtained were validated to show that the proposed design successfully supervises the PVSNC.100% of the simulated faults were detected and identified with the designed methodology, whose usefulness was additionally shown when having a maximum rate of 0.22% of false alarm in all the tests done.Esta investigación tiene como objetivo el diseño de una metodología de diagnóstico de fallos para contribuir al mejoramiento de los indicadores de eficiencia, mantenimiento y disponibilidad de los Sistemas Fotovoltaicos de Conexión a Red (SFVCR). Para lograr dicho objetivo, se realiza el estudio del inversor de conexión a red y del modelo matemático del generador fotovoltaico. Luego se cuantifican las pérdidas operacionales del generador fotovoltaico y se adapta el modelo matemático de éste a las condiciones reales del sistema a través de un ajuste polinomial. Un sistema real de conexión a red de potencia nominal 7.5 kWp, instalado en el Centro de Investigaciones de Energía Solar (CIES) en la provincia Santiago de Cuba, se utiliza para evaluar la metodología propuesta. Con los resultados obtenidos se valida el diseño propuesto para demostrar que éste supervisa con éxito el SFVCR. La metodología fue capaz de detectar e identificar el 100 % de los fallos simulados y los ensayos realizados tuvieron como máximo una tasa de falsa alarma de 0.22 %, evidenciándose su utilidad

Caracterización citológica de hepatopatías en perros y gatos

Diferentes técnicas diagnósticas complementarias se han aplicado durante losúltimos años en medicina veterinaria. Debido a su implementación se han realizado diagnósticosnovedosos en animales, pero aún es necesario determinar sensibilidad y especificidadde las mismas. Para la evaluación de las enfermedades hepáticas se dispone fundamentalmentede técnicas no invasivas, como las pruebas bioquímicas, la ultrasonografía y otras.La realización de biopsias es fundamental en muchos casos para determinar la causa o elpronóstico de las alteraciones encontradas, por lo cual todas estas técnicas deben considerarsecomo parte de un sistema de diagnóstico integrado. Se describen aquí los resultadosde la realización de la técnica de punción con aguja fina guiada por ecografía, aplicada aveintidós pacientes con sintomatología hepática, que concurrieron al Hospital de Clínicas dela Facultad de Ciencias Veterinarias de la UNNE durante el primer semestre del año 2007.Se detallan hallazgos citológicos significativos para la caracterización de diferentes hepatopatíasen perros y gatos

Luminous Satellites of Early-Type Galaxies I: Spatial Distribution

We study the spatial distribution of faint satellites of intermediate redshift (0.1<z<0.8), early-type galaxies, selected from the GOODS fields. We combine high resolution HST images and state-of-the-art host subtraction techniques to detect satellites of unprecedented faintness and proximity to intermediate redshift host galaxies (up to 5.5 magnitudes fainter and as close as 0."5/2.5 kpc to the host centers). We model the spatial distribution of objects near the hosts as a combination of an isotropic, homogenous background/foreground population and a satellite population with a power law radial profile and an elliptical angular distribution. We detect a significant population of satellites, Ns =1.7 (+0.9,-0.8) that is comparable to the number of Milky Way satellites with similar host-satellite contrast.The average projected radial profile of the satellite distribution is isothermal, gamma_p= -1.0(+0.3,-0.4), which is consistent with the observed central mass density profile of massive early-type galaxies. Furthermore, the satellite distribution is highly anisotropic (isotropy is ruled out at a >99.99% confidence level). Defining phi to be the offset between the major axis of the satellite spatial distribution and the major axis of the host light profile, we find a maximum posterior probability of phi = 0 and |phi| less than 42 degrees at the 68% confidence level. The alignment of the satellite distribution with the light of the host is consistent with simulations, assuming that light traces mass for the host galaxy as observed for lens galaxies. The anisotropy of the satellite population enhances its ability to produce the flux ratio anomalies observed in gravitationally lensed quasars.Comment: 21 pages, 16 figures, Accepted for publication in Ap

Stellar populations of galaxies in the ALHAMBRA survey up to z∼1z \sim 1. I. MUFFIT: A Multi-Filter Fitting code for stellar population diagnostics

We present MUFFIT, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and we check its reliability and feasibility with real galaxy data from the ALHAMBRA survey. Making use of an error-weighted $\chi^2$-test, we compare the multi-filter fluxes of galaxies with the synthetic photometry of mixtures of two single stellar populations at different redshifts and extinctions, to provide through a Monte Carlo method the most likely range of stellar population parameters (mainly ages and metallicities), extinctions, redshifts, and stellar masses. To improve the diagnostic reliability, MUFFIT identifies and removes from the analysis those bands that are significantly affected by emission lines. We highlight that the retrieved age-metallicity locus for a sample of $z \le 0.22$ early-type galaxies in ALHAMBRA at different stellar mass bins are in very good agreement with the ones from SDSS spectroscopic diagnostics. Moreover, a one-to-one comparison between the redshifts, ages, metallicities, and stellar masses derived spectroscopically for SDSS and by MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters. In addition, and using as input the results from photometric-redshift codes, MUFFIT improves the photometric-redshift accuracy by $\sim 10$-$20\%$, and it also detects nebular emissions in galaxies, providing physical information about their strengths. Our results show the potential of multi-filter galaxy data to conduct reliable stellar population studies with the appropiate analysis techniques, as MUFFIT.Comment: 31 pages, 18 figures, accepted for publication in A&

The ALHAMBRA survey: Accurate merger fractions by PDF analysis of photometric close pairs

Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. We improve the current methodologies to estimate the merger fraction f_m from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space, (ii) including the variation in the luminosity of the sources with z in both the selection of the samples and in the luminosity ratio constrain, and (iii) splitting individual PDFs into red and blue spectral templates to deal robustly with colour selections. We test the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. The merger fractions and rates from the ALHAMBRA survey are in excellent agreement with those from spectroscopic work, both for the general population and for red and blue galaxies. With the merger rate of bright (M_B <= -20 - 1.1z) galaxies evolving as (1+z)^n, the power-law index n is larger for blue galaxies (n = 2.7 +- 0.5) than for red galaxies (n = 1.3 +- 0.4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is N_m = 0.57 +- 0.05 for red galaxies and N_m = 0.26 +- 0.02 for blue galaxies. Our new methodology exploits statistically all the available information provided by photometric redshift codes and provides accurate measurements of the merger fraction by close pairs only using photometric redshifts. Current and future photometric surveys will benefit of this new methodology.Comment: Submitted to A&A, 15 pages, 15 figures, 6 tables. Comments are welcome. Close pair systems available at https://cloud.iaa.csic.es/alhambra/catalogues/ClosePairs

The ALHAMBRA Survey: Bayesian Photometric Redshifts with 23 bands for 3 squared degrees

The ALHAMBRA (Advance Large Homogeneous Area Medium Band Redshift Astronomical) survey has observed 8 different regions of the sky, including sections of the COSMOS, DEEP2, ELAIS, GOODS-N, SDSS and Groth fields using a new photometric system with 20 contiguous ~ $300\AA$ filters covering the optical range, combining them with deep $JHKs$ imaging. The observations, carried out with the Calar Alto 3.5m telescope using the wide field (0.25 sq. deg FOV) optical camera LAICA and the NIR instrument Omega-2000, correspond to ~700hrs on-target science images. The photometric system was designed to maximize the effective depth of the survey in terms of accurate spectral-type and photo-zs estimation along with the capability of identification of relatively faint emission lines. Here we present multicolor photometry and photo-zs for ~438k galaxies, detected in synthetic F814W images, complete down to I~24.5 AB, taking into account realistic noise estimates, and correcting by PSF and aperture effects with the ColorPro software. The photometric ZP have been calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission line galaxies. We calculate photometric redshifts with the BPZ2 code, which includes new empirically calibrated templates and priors. Our photo-zs have a precision of $dz/(1+z_s)=1$ for I<22.5 and 1.4% for 22.5<I<24.5. Precisions of less than 0.5% are reached for the brighter spectroscopic sample, showing the potential of medium-band photometric surveys. The global $P(z)$ shows a mean redshift =0.56 for I=0.86 for I<24.5 AB. The data presented here covers an effective area of 2.79 sq. deg, split into 14 strips of 58.5'x15.5' and represents ~32 hrs of on-target.Comment: The catalog data and a full resolution version of this paper is available at https://cloud.iaa.csic.es/alhambra

The ALHAMBRA survey : Estimation of the clustering signal encoded in the cosmic variance

The relative cosmic variance ($\sigma_v$) is a fundamental source of uncertainty in pencil-beam surveys and, as a particular case of count-in-cell statistics, can be used to estimate the bias between galaxies and their underlying dark-matter distribution. Our goal is to test the significance of the clustering information encoded in the $\sigma_v$ measured in the ALHAMBRA survey. We measure the cosmic variance of several galaxy populations selected with $B-$band luminosity at $0.35 \leq z < 1.05$ as the intrinsic dispersion in the number density distribution derived from the 48 ALHAMBRA subfields. We compare the observational $\sigma_v$ with the cosmic variance of the dark matter expected from the theory, $\sigma_{v,{\rm dm}}$. This provides an estimation of the galaxy bias $b$. The galaxy bias from the cosmic variance is in excellent agreement with the bias estimated by two-point correlation function analysis in ALHAMBRA. This holds for different redshift bins, for red and blue subsamples, and for several $B-$band luminosity selections. We find that $b$ increases with the $B-$band luminosity and the redshift, as expected from previous work. Moreover, red galaxies have a larger bias than blue galaxies, with a relative bias of $b_{\rm rel} = 1.4 \pm 0.2$. Our results demonstrate that the cosmic variance measured in ALHAMBRA is due to the clustering of galaxies and can be used to characterise the $\sigma_v$ affecting pencil-beam surveys. In addition, it can also be used to estimate the galaxy bias $b$ from a method independent of correlation functions.Comment: Astronomy and Astrophysics, in press. 9 pages, 4 figures, 3 table