The characterization of the nominal power under real operating conditions is crucial for the correct evaluation of a photovoltaic generator. Several earlier studies proposed different methods based on empirical models for the estimation of the nominal power. These methods require experimental data obtained during optimal days under clear sky conditions and are not suitable for days deviating from these optimal conditions and, thus, generating a significant amount of noise in the data. In this sense, we propose a non-parametric statistical approach to filter out this noise to reliably estimate the real nominal power in the latter conditions. The period of study was 107 days. These were divided in two categories, clear and partly cloudy sky conditions. The results show that our statistical method allows to obtain the same nominal power under partly cloudy conditions as under clear sky. Thi...

A seroprevalence study on 5439 cattle from April to June 2007 was conducted based on a circumstantial diagnosis of two cases of bovine brucellosis in the district of Codo del Pozuzo, en the region of Huanuco. Two animals resulted positive to the Rose Bengal test but negative to the Complement Fixation test. The beta distribution using a simulation model showed a prevalence of 0.02% with a minimum interval of confidence of 0 and maximum of 0.06%.

The cysticercosis is a zoonotic disease of world-wide distribution and in Peru represents the main parasitic zoonosis with 17 and 75% seroprevalence in humans and pigs respectively. The high seroprevalence indicates that Peru is an endemic area. The objective of this study was to obtain a representative level of infection with T. solium larvae in pigs of Omia, Nuevo Chirimoto, Mashuyacu and Tocuya villages, Omia district, Amazonas. Sampling was conducted in 48 animals, resulting 27.1% (13/48) of positives to the Electroimmuno Transference Blot (EITB) test. Data was analyzed in a program that uses stochastic simulations of the beta distribution (@Risk®) resulting in a mean seroprevalence of 28% with a distribution between 18.2 and 38.8%. Seroprevalence for Tocuya was 14.3% (0.8-39.3%), Nuevo Chirimoto was 4.8% (0.3-13.9%), Mashuyacu was 71.4% (50.5-88.7%), and Omia was 35.7% (16.6-57.2%)...

En base a un diagnóstico circunstancial de dos casos de brucelosis en un hato bovino del distrito de Codo del Pozuzo, Huánuco, se llevó a cabo un estudio de prevalencia de Brucella sp. en 5439 bovinos entre abril a junio de 2007. Dos bovinos resultaron positivos a la prueba de Rosa de Bengala, pero negativos a la prueba confirmativa de Fijación del Complemento. El modelo de simulaciones estocásticas de distribución beta mostró una prevalencia de 0.02% con intervalo de confianza mínimo de 0 y máximo de 0.06%.

La cisticercosis es una enfermedad zoonótica de distribución mundial y en el Perú representa la principal zoonosis parasitaria con seroprevalencias que alcanzan el 17% en humanos y 75% en porcinos, calificando al país como área endémica. El objetivo de este trabajo fue obtener un valor representativo del grado de infección de la forma larvaria de Taenia solium en cerdos criados en los caseríos de Omia, Nuevo Chirimoto, Mashuyacu y Tocuya del distrito de Omia, Amazonas. Se muestreó a 48 animales, resultando el 27.1% (13/48) positivo a la prueba de Electroinmuno Transferencia Blot (EITB). Estos valores se ingresaron en un programa de simulaciones estocásticas de distribución beta (@Risk®), calculándose una seroprevalencia media de 28.0% con una distribución entre 18.2 y 38.8%. La seroprevalencia media para el caserío de Tocuya fue de 14.3% (0.8-39.3%), Nuevo Chirimoto de 4.8...

The aim of this study was to evaluate the economic impact caused by avian infectious laryngotracheitis (ILT) in a commercial layer farm located in the district of Chilca, Lima, with a population of 14 415 hens that was affected by the ILT from August 2008 to March 2010. A survey was conducted and visits to the farm were done to collect biosafety and production data, and production costs of the campaign with ILT and the previous campaign without ILT. The economic impact was evaluated by comparing data from both campaigns using a stochastic distribution model with the risk analysis program @ RISK 5.1®. The cost per kilogram of eggs increased by 34%, egg production declined by 16%, and mortality increased by 18% in the campaign with ILT.

The aim of this study was to quantify the economic impact of avian infectious laryngotracheitis (ILT) on productive and economic performance of broilers. Two batches of 35 000 broilers each up to 49 days of age were evaluated. The first batch was affected for ILT while the other was not affected. A survey was conducted to collect information about productive data, biosecurity and production cost per batch, as well as additional costs related to the control of the disease. The economic impact was evaluated by comparing data from both batches using a stochastic distribution model with the risk analysis program @Risk 5.1®. Besides, a statistical analysis was done to determine difference between productive data of the two batches. In the one with ILT the mortality increased by 3.51% and feed conversion rate by 16.8%, while the productive efficiency decreased by 27.3% compared with the batch...

El objetivo del estudio fue evaluar el impacto económico causado por la laringotraqueitis infecciosa aviar (LT) en una granja de ponedoras comerciales, ubicada en el distrito de Chilca, Lima, con una población de 14 415 gallinas, que fue afectada por la LT entre agosto de 2008 hasta marzo de 2009. Se elaboró una encuesta y se recolectaron datos sobre bioseguridad, producción y costos de producción del lote afectado con LT así como de la campaña previa sin LT. El impacto económico causado por LT fue evaluado comparando ambas campañas. Se utilizó un modelo de distribución estocástica con el programa para análisis de riesgo @RISK 5.1®. El costo por kilogramo de huevos producido en el lote afectado con LT se incrementó en 34% comparado con el lote libre de la enfermedad; asimismo, la producción de huevos disminuyó en 16% y la mortalidad se incrementó en 18%.

The aim of this study was to quantify the economic impact of avian infectious laryngotracheitis (ILT) on productive and economic performance of broilers. Two batches of 35 000 broilers each up to 49 days of age were evaluated. The first batch was affected for ILT while the other was not affected. A survey was conducted to collect information about productive data, biosecurity and production cost per batch, as well as additional costs related to the control of the disease. The economic impact was evaluated by comparing data from both batches using a stochastic distribution model with the risk analysis program @Risk 5.1®. Besides, a statistical analysis was done to determine difference between productive data of the two batches. In the one with ILT the mortality increased by 3.51% and feed conversion rate by 16.8%, while the productive efficiency decreased by 27.3% compared with the batch...

En este trabajo se estudia las propiedades estructurales y morfológicas de las películas delgadas de plata de 60 nm de espesor, depositadas sobre sustrato de SiO2 y tratadas térmicamente a distintas temperaturas desde 250 hasta 1000℃. Se ha encontrado que al incrementar la temperatura de recocido, la película de plata se cristaliza en la dirección [111] aumentando la rugosidad superficial y formando islas. Sin embargo, entre la temperatura de recocido de 800 a 900°C se observa un cambio en la orientación preferencial a la dirección [200]. Se discute este cambio de orientación mediante los procesos de difusión.

The aim of the present work was to estimate the seroprevalence of bovine brucellosis in cattle reared under an extensive breeding system in the district of Puerto Inca, Huánuco, Peru in 2007. Blood samples were collected (n=3321) for the diagnosis of Brucella spp. by the Rose Bengal agglutination test. None of the samples resulted positive and the prevalence showed by the @Risk stochastic simulations software was 0.031% with ranges of 0.0008 and 0.1144%. The low prevalence would allow the implementation of a program to eradicate bovine brucellosis in the district of Puerto Inca.

El estudio tuvo como objetivo determinar la seroprevalencia de brucelosis en bovinos de crianza extensiva en el distrito de Puerto Inca, provincia de Puerto Inca, departamento de Huánuco, en el año 2007. Se colectaron muestras de sangre de 3221 animales para el diagnóstico de Brucella sp. mediante la prueba de aglutinación Rosa de Bengala. No se encontraron reactores positivos, y con el programa @Risk de simulaciones estocástica de distribución beta se calculó una prevalencia media de 0.031% con rangos de 0.0008 a 0.1144%. La baja prevalencia permitiría implementar un programa de erradicación de brucelosis bovina en el distrito de Puerto Inca.

This research was funded by the Research Management Office (DGI) of the Pontificia Universidad Católica del Perú (PUCP). The authors have been supported by the PUCP under the PhD scholarship program Huiracocha (J A Guerra) and by the National Council of Science and Technology (CONCYTEC) under the scholarships granted to the PUCP (J R Angulo and J Llamoza). The author would like to thank Prof Dr H P Strunk, F Benz and Dr Y Weng of the University of Stuttgart for the TEM measurements.

The purpose of the study was to detect the frequency of antibodies against Leptospira sp in the wild neck white squirrel population (Sciurus stramineus) caught in the Parque de las Leyendas Zoo, Lima. Thirty five blood samples were collected from neck white squirrels, males and females of various ages that were trapped in various areas in the zoo. Samples were analyzed for antibodies against Leptospira sp by micro agglutination test. The 82.3% (29/35) of animals had antibodies against Leptospira sp of which 60% corresponded to the icterohemorraghiae serovar, followed by georgia (31.4%), canicola (5.7%), and australis (2.8%). None statistical difference between the presence of antibodies against Leptospira sp and the variables sex, age and area of trapping was found. The results indicated that leptospiral infection is present in the neck white squirrels, and the disease poses a health ris...

El objetivo del estudio fue detectar la frecuencia de anticuerpos contra Leptospira sp en la población de ardillas nuca blanca (Sciurus stramineus) silvestres capturadas en el zoológico Parque de Las Leyendas, Lima. Se colectó 35 muestras de suero de ardillas nuca blanca de ambos sexos, de diferentes edades y zonas del zoológico, para la detección de anticuerpos contra Leptospira sp mediante la prueba de microaglutinación. El 82.3% (29/35) de animales presentó anticuerpos contra Leptospira sp, donde el 60% correspondió al serovar icterohemorraghiae, seguidos por georgia (31.4%), canicola (5.7%), y australis (2.8%). No hubo diferencia estadística entre la presencia de anticuerpos contra Leptospira sp y las variables sexo, edad y área de captura de las ardillas. Los resultados indican que la infección leptospiral está presente en las ardillas nuca blanca pudiendo constituir un ...

This study presents for the first time the spectral impact on the performance of different photovoltaic (PV) technologies in Lima, Peru. We experimentally monitored the spectral distributions over one year (March 2019–February 2020). The average photon energy (APE) is calculated as a representative parameter to evaluate the spectral distributions. The spectral mismatch factor (MM) enables an estimation of the spectral gains of distinct PV technologies: amorphous silicon (a-Si), perovskite, cadmium telluride (CdTe), multicrystalline silicon (multi-Si), monocrystalline silicon (mono-Si) and copper indium gallium selenide with two distinct band-gaps (CIGS-1 and CIGS-2). We found that the annual APE has a value of 1.923 eV, indicating that the spectrum is shifted to shorter wavelengths. In contrast to studies performed in other locations, the spectral distribution shows relatively small mo...

The aim of the study was to establish whether the presence of Cryptosporidium parvum in the dam is a risk factor for the presentation of the pathogen in the baby alpaca. The study included 698 alpaca dams and their offspring less than 30 days of age. The sampling took place from January till March 2007 in the localities of La Raya, Choquecota, Chillihua, Maranganí and Silli in Canchis province, Cusco, Peru. Fecal samples were collected from the rectum, processed using the Modified Ziehl-Neelsen stain and observed by microscopy. Risk analysis was done through logistic regressions. Results showed that a baby alpaca born from a positive dam to C. parvum was 2.1 times more likely to get infected with the parasite as compared with others born from a negative dam (p<0.05). Likewise, sex and presence of diarrhea were not significant, whereas place of breeding showed to be a protection facto...

The aim of the study was to establish whether the presence of Cryptosporidium parvum in the dam is a risk factor for the presentation of the pathogen in the baby alpaca. The study included 698 alpaca dams and their offspring less than 30 days of age. The sampling took place from January till March 2007 in the localities of La Raya, Choquecota, Chillihua, Maranganí and Silli in Canchis province, Cusco, Peru. Fecal samples were collected from the rectum, processed using the Modified Ziehl-Neelsen stain and observed by microscopy. Risk analysis was done through logistic regressions. Results showed that a baby alpaca born from a positive dam to C. parvum was 2.1 times more likely to get infected with the parasite as compared with others born from a negative dam (p<0.05). Likewise, sex and presence of diarrhea were not significant, whereas place of breeding showed to be a protection facto...

This article presents the benefits of two simple analytical models for estimating the outdoor performance of three different photovoltaic technologies in Lima, Peru. The Osterwald and the constant fill factor models are implemented to estimate the maximum power delivered by three photovoltaic module technologies: aluminum back surface field, heterojunction with intrinsic thin-layer and amorphous/microcrystalline thin-film tandem. A 12-months experimental campaign is carried out through measurements of current-voltage curves, irradiance and module temperature. The results show that both models overestimate the modelled power when compared to the measured one. In order to correct the maximum power predicted by both models, a correction factor is introduced. This correction factor allows us to estimate losses and a respective effective nominal power to minimize the prediction error on a mon...

This work presents the firsts results of the experimental characterization campaign under outdoor conditions carried out with three different photovoltaic (PV) module technologies: Standard poly-crystalline silicon (poly-Si) aluminum back surface field (Al-BSF) cells, mono-crystalline (c-Si) Heterojunction with Intrinsic Thin-Layer (HIT) cells, and amorphous and microcrystalline silicon (a-Si/µc-Si) thin-film tandem cells. We studied the behavior of these PV technologies and their performance in Lima's desertic and coastal climate during the period from May 2019 to July 2019. For this study, a new outdoor-PV laboratory was implemented at the Pontificia Universidad Católica del Perú (PUCP) with the help of the IDEA research group of the University of Jaén (UJA), Spain. The laboratory enables the characterization of PV modules by extracting the electrical parameters from the current-vo...