Observed degradation in photovoltaic plants affected by hot-spots

A number of findings have shown that the test procedures currently available to determine the reliability and durability of photovoltaic (PV) modules are insufficient to detect certain problems. To improve these procedures, ongoing research into the actual performance of the modules in the field is required. However, scientific literature contains but few references to field studies of defective modules. This article studies two different localized heating phenomena affecting the PV modules of two large-scale PV plants in Spain. The first problem relates to weak solder joints whilst the second is due to microcracks on the module cells. For both cases, the cause is identified, and consideration is given with regard to the effect on performance, the potential deterioration over time, and a way to detect the problems identified. The findings contained in this paper will prove to be of considerable interest to maintenance personnel at large-scale PV plants and also to those responsible for setting module quality standards and specifications, and even the PV module manufacturers themselves

STC power for 15MW of PV comparing nameplate, initial power and power after 4 years

To date, the majority of quality controls performed at PV plants are based on the measurement of a small sample of individual modules. Consequently, there is very little representative data on the real Standard Test Conditions (STC) power output values for PV generators. This paper presents the power output values for more than 1300 PV generators having a total installed power capacity of almost 15.3 MW. The values were obtained by the INGEPER-UPNA group, in collaboration with the IES-UPM, through a study to monitor the power output of a number of PV plants from 2006 to 2009. This work has made it possible to determine, amongst other things, the power dispersion that can be expected amongst generators made by different manufacturers, amongst generators made by the same manufacturer but comprising modules of different nameplate ratings and also amongst generators formed by modules with the same characteristics. The work also analyses the STC power output evolution over time in the course of this 4-year study. The values presented here could be considered to be representative of generators with fault-free modules

Storage requirements for PV power ramp-rate control

Short-term variability in the power generated by large grid-connected photovoltaic (PV) plants can negatively affect power quality and the network reliability. New grid-codes require combining the PV generator with some form of energy storage technology in order to reduce short-term PV power fluctuation. This paper proposes an effective method in order to calculate, for any PV plant size and maximum allowable ramp-rate, the maximum power and the minimum energy storage requirements alike. The general validity of this method is corroborated with extensive simulation exercises performed with real 5-s one year data of 500 kW inverters at the 38.5 MW Amaraleja (Portugal) PV plant and two other PV plants located in Navarra (Spain), at a distance of more than 660 km from Amaraleja

Hoverflies (Diptera: Syrphidae) of El Ventorrillo Biological Station, Madrid province, Spain: a perspective from a late twentieth century inventory

Temporal comparisons of a site's biodiversity depend on the availability of at least two asynchronous data sets on a bioindicator group. The Sierra de Guadarrama, a mountain range in central Spain has a high biodiversity and representative sites such as El Ventorrillo Biological Station (Madrid province) play an important role in research and monitoring of the Sierra biodiversity. Although unevenly and randomly, hoverflies of the Sierra de Guadarrama have been surveyed for decades, but never at El Ventorrillo. This important group of pollinators, aphid predators and bioindicators was sampled with a Malaise trap at El Ventorrillo from June 1989 to June 1990. A total of 51 species were identified (20 spp. of Eristalinae and 31 spp. of Syrphinae), 22 of which were new to the Sierra de Guadarrama and 17 to the Madrid province. The genera Brachypalpus and Didea were also new to the Madrid province. The Sierra de Guadarrama now has 126 species recorded and the Madrid province 150. Within the Sierra de Guadarrama, El Ventorrillo becomes the second locality in number of hoverfly species recorded after El Escorial (64 spp.). In the Malaise trap catch, hoverflies with zoophagous larvae had a higher representation than those of other guilds, both in species richness and abundance. The results provided here for El Ventorrillo represent a baseline for future biodiversity studies at this site with a similar experimental design, for example, to detect changes in hoverfly diversities along time.We thank Vicerrectorado de Investigación y Transferencia de Conocimiento, University of Alicante to fund Antonio Ricarte's position (UATAL05). This study belongs to the ‘Fauna Ibérica’ Project PGC2018-095851-A-C65A (‘Ministerio de Ciencia, Innovación y Universidades’, Spain)

Propuesta metodológica para la implementación de una arquitectura orientada a servicios en entornos de Sistemas de Fabricación Distribuida

Los Sistemas de Fabricación de Siguiente Generación, concebidos por la organización IMS (Intelligent Manufacturing Systems), cubrirán la demanda de un mercado cada vez más cambiante y exigente, reuniendo de forma dinámica las funciones de múltiples sistemas internos y externos a la propia empresa de fabricación en lo que conocemos por una empresa extendida. Sin embargo, resulta difícil estructurar estos sistemas para conseguir la flexibilidad deseada y la interoperabilidad con los de las demás organizaciones. Además, un defecto en el sistema tendría un fuerte impacto: afectaría no sólo a la empresa propietaria del sistema, sino también a sus colaboradores. Por estas razones, creemos que una buena decisión sería emplear una arquitectura orientada a servicios diseñada siguiendo una metodología que adopte los servicios como concepto central, en vez de como un detalle de implementación. Para que la arquitectura sea fiable en su conjunto, tendrá que ayudar a localizar errores antes de que sucedan en un entorno de producción. En este artículo proponemos el uso de técnicas de pruebas específicas para este tipo de sistemas, realizamos una comparación de las metodologías existentes para el desarrollo de arquitecturas orientadas a servicios y esbozamos una serie de extensiones sobre una de las existentes para integrar técnicas de prueba.As envisioned by the IMS (Intelligent Manufacturing Systems), Next Generation Manufacturing Systems will satisfy the needs of an increasingly fast-paced and demanding market by dynamically integrating systems from inside and outside the manufacturing firm itself into a so-called extended enterprise. However, organizing these systems to ensure the maximum flexibility and interoperability with those from other organizations is difficult. Additionally, a defect in the system would have a great impact: it would affect not only its owner, but also its partners. For these reasons, we argue that a service-oriented architecture (SOA) would be a good candidate. It should be designed following a methodology where services play a central role, instead of being an implementation detail. In order for the architecture to be reliable enough as a whole, the methodology will need to help find errors before they arise in a production environment. In this paper we propose using SOA-specific testing techniques, compare some of the existing SOA methodologies and outline several extensions upon one of them to integrate testing techniques

Una emulsión lipídica basada exclusivamente en aceite de pescado revierte la colestasis

Prolonged parenteral nutrition (PN) leads to liver damage. Recent interest has focused on the lipid component of PN. A lipid emulsion based on w-3 fatty acids decrease conjugated bilirubin. A mixed lipid emulsion derived from soybean, coconut, olive, and fish oils reverses jaundice. Here we report the reversal of cholestasis and the improvement of enteral feeding tolerance in 1 infant with intestinal failure-associated liver disease. Treatment involved the substitution of a mixed lipid emulsion with one containing primarily omega-3 fatty acids during 37 days. Growth and biochemical tests of liver function improved significantly. This suggests that fat emulsions made from fish oils may be more effective means of treating this condition compared with an intravenous lipid emulsion containing soybean oil, medium -chain triglycerides, olive oil, and fish oilLa nutrición parenteral prolongada produce daño hepático. Recientemente se ha comunicado el efecto de las emulsiones lipídicas intravenosas basadas exclusivamente en ácidos grasos omega-3 en la resolución de la colestasis. Lo mismo se ha observado con el uso de emulsiones lipídicas mixta derivadas del aceite de soja, coco, oliva y pescado. Comunicamos la desaparición de colestasis y mejoría de la tolerancia enteral en un niño con enfermedad hepática asociada a nutrición parenteral. El tratamiento consistió en sustituir una emulsión lipídica mixta por otra que contenía de forma exclusiva aceite de pescado durante 37 días. El crecimiento y los datos bioquímicos de función hepática mejoraron de forma significativa. Este caso sugiere que emulsiones lipídicas intravenosas a partir de aceite de pescado pueden ser mas eficaces para tratar la colestasis si se comparan con emulsiones mixta

Haptically assisted connection procedure for the reconstruction of dendritic spines

Dendritic spines are thin protrusions that cover the dendritic surface of numerous neurons in the brain and whose function seems to play a key role in neural circuits. The correct segmentation of those structures is difficult due to their small size and the resulting spines can appear incomplete. This paper presents a four-step procedure for the complete reconstruction of dendritic spines. The haptically driven procedure is intended to work as an image processing stage before the automatic segmentation step giving the final representation of the dendritic spines. The procedure is designed to allow both the navigation and the volume image editing to be carried out using a haptic device. A use case employing our procedure together with a commercial software package for the segmentation stage is illustrated. Finally, the haptic editing is evaluated in two experiments; the first experiment concerns the benefits of the force feedback and the second checks the suitability of the use of a haptic device as input. In both cases, the results shows that the procedure improves the editing accuracy

Application of a Pharmacogenetics-Based Precision Medicine Model (5SPM) to Psychotic Patients That Presented Poor Response to Neuroleptic Therapy

[EN] Antipsychotics are the keystone of the treatment of severe and prolonged mental disorders. However, there are many risks associated with these drugs and not all patients undergo full therapeutic profit from them. The application of the 5 Step Precision Medicine model(5SPM), based on the analysis of the pharmacogenetic profile of each patient, could be a helpful tool to solve many of the problematics traditionally associated with the neuroleptic treatment. In order to solve this question, a cohort of psychotic patients that showed poor clinical evolution was analyzed. After evaluating the relationship between the prescribed treatment and pharmacogenetic profile of each patient, a great number of pharmacological interactions and pharmacogenetical conflicts were found. After reconsidering the treatment of the conflictive cases, patients showed a substantial reduction on mean daily doses and polytherapy cases, which may cause less risk of adverse effects, greater adherence, and a reduction on economic costs

Caracterización geotécnica y mineralógica de bentonitas. Comparativa de distintos métodos de análisis de tamaño de partícula

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Economic evaluation of percutaneous cryoablation vs conventional surgery in extra-abdominal desmoid tumours in the Spanish healthcare system

BackgroundDesmoid tumours (DTs) or deep fibromatosis are benign soft-tissue tumours, sometimes locally aggressive, requiring intervention on some cases. Surgery has been the gold standard, but new less invasive techniques such as percutaneous cryoablation have proved their effectiveness, reducing health resources and complications. The study aimed to compare the total cost of percutaneous cryoablation and conventional surgery for patients with extra-abdominal and/or abdominal wall DTs, candidates for local ablative treatment in Spain.MethodsA cost-analysis model was developed. An expert panel provided data about resource consumption for the percutaneous cryoablation technique and validated the epidemiology used for target population estimation. Unitary resources cost (euro 2022) derived from local cost databases. A retrospective analysis of 54 surgical cases in 3 Spanish hospitals was performed to estimate the cost of conventional surgery based on the cost of the Diagnosis-Related group (DRG) codes identified on this patient sample, weighted by each DRG proportion. The total cost for each alternative included intervention cost and complications cost, considering debridement required in 4.5% of cases with percutaneous cryoablation and minor surgery for surgical site infection in 18.0% for conventional surgery.ResultsThe total cost for percutaneous cryoablation (euro 5774.78/patient-year) was lower than the total cost for conventional surgery (euro 6780.98/patient-year), yielding cost savings up to euro 80,002 in 1 year for the entire cohort of 80 patients with DTs eligible for intervention estimated in Spain. One-way sensitivity analyses confirmed the results' robustness.ConclusionPercutaneous cryoablation versus conventional surgery would yield cost savings for the management of DT patients in Spain.Critical relevance statementThis manuscript provides insight into the economic impact derived from the savings related to the use of percutaneous cryoablation for desmoid-type tumours from the perspective of the Spanish National Healthcare System, providing useful information for the health decision-making process.Key points center dot Desmoid tumours are locally aggressive and may require local therapy.center dot Percutaneous cryoablation procedure is less invasive than the conventional surgery.center dot Cost comparison shows savings associated to percutaneous cryoablation use.Key points center dot Desmoid tumours are locally aggressive and may require local therapy.center dot Percutaneous cryoablation procedure is less invasive than the conventional surgery.center dot Cost comparison shows savings associated to percutaneous cryoablation use.Key points center dot Desmoid tumours are locally aggressive and may require local therapy.center dot Percutaneous cryoablation procedure is less invasive than the conventional surgery.center dot Cost comparison shows savings associated to percutaneous cryoablation use