Estudo da distribuição do fluxo de energia solar e da eficiência ótica de um concentrador linear Fresnel com absorvedor plano

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Apresenta-se uma análise da uniformidade da densidade do fluxo de energia solar concentrada e da eficiência de um concentrador solar do tipo refletor linear Fresnel, existente no Laboratório de Energia e Ambiente da Faculdade de Tecnologia da Universidade de Brasília. Esta análise é realizada através da simulação com o software TONATIUH conjuntamente com o software OCTAVE. Apresentam-se os valores da média mensal por hora da eficiência ótica e do índice de uniformidade do fluxo de energia solar concentrada na superfície do absorvedor. Em formato de mapa de cores mostra-se a distribuição da irradiância na superfície do absorvedor para diferentes horários e meses do ano. O concentrador apresenta boa uniformidade na distribuição do fluxo no período das 10h até as 14h para todos os meses do ano e uma eficiência ótica máxima de 0,79. Verifica-se que as perdas de final de linha na iluminação do absorvedor diminuem significativamente a eficiência elétrica do sistema.ABSTRACT: An analysis of the uniformity of the concentrated solar energy flux density and the efficiency of a Fresnel linear reflector solar concentrator is presented. This concentrator is located at the Energy and Environment Laboratory of the Faculty of Technology of the University of Brasilia. The analysis was carried out through simulation with the software TONATIUH and OCTAVE. The average monthly values per hour of the optical efficiency and uniformity index of the concentrated solar energy flux on the absorber surface are presented. In color map format, the distribution of irradiance on the absorber surface is shown for different times and months of the year. The concentrator shows good uniformity in the flux distribution from 10 am to 2 pm for all months of the year and a maximum optical efficiency of 0.79. It is verified that the end losses of illumination on the absorber reduce significantly the electrical efficiency of the system.info:eu-repo/semantics/publishedVersio

Determinación de parámetros en módulos fotovoltaicos de silicio para diferentes irradiancias y temperaturas : método simplificado con datos del DataSheet

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este artículo propone y describe un modelo numérico para la obtención de los cinco parámetros (corriente foto generada, corriente de saturación, factor de idealidad, resistencia en serie y em paralelo) del circuito equivalente de un módulo fotovoltaico (modelo de un diodo) a partir de los datos dados en el datasheet. Estos parámetros posibilitan determinar el punto de máxima potencia y trazar la curva I-V del módulo para condiciones diferentes a las dadas por los fabricantes de irradiancia y temperatura. Se utiliza el método de Newton-Raphson para resolver el sistema de ecuaciones no lineales del modelo propuesto. Se realiza el muestreo de las diferentes curvas I-V dadas por los fabricantes de dos módulos fotovoltaicos diferentes y se determinan las métricas RMSE y NRMSE. Estas métricas, así como los valores de los cinco parámetros son comparados con los obtenidos por otros modelos propuestos por diferentes autores. El modelo final presentó 100% de convergencia a soluciones válidas para los panales usados en la validación de los resultados.ABSTRACT: This paper proposes and describes a numerical model to obtain the five parameters (photo generated current, saturation current, ideality factor, resistance in series and parallel) of the equivalent single-diode model of photovoltaic cell from the data given in the datasheet. These parameters allow to determine the maximum power point and plot the I-V curve of the module for irradiance and temperatures different from the datasheet. The Newton-Raphson method is used to solve the system of nonlinear equations of the proposed model. The different I-V curves given by the manufacturers of two different photovoltaic modules are sampled and the metrics RMSE and NRMSE are calculated. The metrics obtained, as well as the values of the five parameters are compared with those obtained by other models proposed by different authors. The final model presented 100% convergence to valid solutions for the photovoltaic panels used in the validation of the results.info:eu-repo/semantics/publishedVersio

Outcomes of COVID-19 in 79 patients with IBD in Italy : an IG-IBD study

COVID-19 has rapidly become a major health emergency worldwide. Patients with IBD are at increased risk of infection, especially when they have active disease and are taking immunosuppressive therapy. The characteristics and outcomes of COVID-19 in patients with IBD remain unclear. Design: This Italian prospective observational cohort study enrolled consecutive patients with an established IBD diagnosis and confirmed COVID-19. Data regarding age, sex, IBD (type, treatments and clinical activity), other comorbidities (Charlson Comorbidity Index (CCI)), signs and symptoms of COVID-19 and therapies were compared with COVID-19 outcomes (pneumonia, hospitalisation, respiratory therapy and death). Results: Between 11 and 29 March 2020, 79 patients with IBD with COVID-19 were enrolled at 24 IBD referral units. Thirty-six patients had COVID-19-related pneumonia (46%), 22 (28%) were hospitalised, 7 (9%) required non-mechanical ventilation, 9 (11%) required continuous positive airway pressure therapy, 2 (3%) had endotracheal intubation and 6 (8%) died. Four patients (6%) were diagnosed with COVID-19 while they were being hospitalised for a severe flare of IBD. Age over 65 years (p=0.03), UC diagnosis (p=0.03), IBD activity (p=0.003) and a CCI score >1 (p=0.04) were significantly associated with COVID-19 pneumonia, whereas concomitant IBD treatments were not. Age over 65 years (p=0.002), active IBD (p=0.02) and higher CCI score were significantly associated with COVID-19-related death. Conclusions: Active IBD, old age and comorbidities were associated with a negative COVID-19 outcome, whereas IBD treatments were not. Preventing acute IBD flares may avoid fatal COVID-19 in patients with IBD. Further research is needed

Effectiveness of individualized lung recruitment strategies at birth: An experimental study in preterm lambs

Respiratory transition at birth involves rapidly clearing fetal lung liquid and preventing efflux back into the lung while aeration is established. We have developed a sustained inflation (SIOPT) individualized to volume response and a dynamic tidal positive end-expiratory pressure (PEEP) (open lun

Activities related to inflammatory bowel disease management during and after the coronavirus disease 2019 lockdown in Italy: How to maintain standards of care

Background and aims:Restructuring activities have been necessary during the lockdown phase of the coronavirusdisease 2019 (COVID-19) pandemic. Few data are available on the post-lockdown phase in terms of health-careprocedures in inflammatory bowel disease (IBD) care, and no data are available specifically from IBD units. Weaimed to investigate how IBD management was restructured during the lockdown phase, the impact of therestructuring on standards of care and how Italian IBD units have managed post-lockdown activities.Methods:A web-based online survey was conducted in two phases (April and June 2020) among the Italian Groupfor IBD affiliated units within the entire country. We investigated preventive measures, the possibility of continuingscheduled visits/procedures/therapies because of COVID-19 and how units resumed activities in the post-lockdownphase.Results:Forty-two referral centres participated from all over Italy. During the COVID-19 lockdown, 36% of first visitsand 7% of follow-up visits were regularly done, while>70% of follow-up scheduled visits and 5% of first visits weredone virtually. About 25% of scheduled endoscopies and bowel ultrasound scans were done. More than 80% ofbiological therapies were done as scheduled. Compared to the pre-lockdown situation, 95% of centres modifiedmanagement of outpatient activity, 93% of endoscopies, 59% of gastrointestinal ultrasounds and 33% of biologicaltherapies. Resumption of activities after the lockdown phase may take three to six months to normalize. Virtualclinics, implementation of IBD pathways and facilities seem to be the main factors to improve care in the future.Conclusion:Italian IBD unit restructuring allowed quality standards of care during the COVID-19 pandemic to bemaintained. A return to normal appears to be feasible and achievable relatively quickly. Some approaches, suchas virtual clinics and identified IBD pathways, represent a valid starting point to improve IBD care in the post-COVID-19 er

Telemedicine and Remote Screening for COVID-19 in Inflammatory Bowel Disease Patients: Results From the SoCOVID-19 Survey

none46noneFantini, Massimo Caludio; Biancone, Livia; Dragoni, Gabriele; Bezzio, Cristina; Miranda, Agnese; Ribaldone, Davide Giuseppe; Bertani, Angela; Bossa, Fabrizio; Allocca, Mariangela; Buda, Andrea; Mocci, Giammarco; Soriano, Alessandra; Guglielmi, Francesco William; Bertani, Lorenzo; Baccini, Flavia; Loddo, Erica; Privitera, Antonino Carlo; Sartini, Alessandro; Viscido, Angelo; Grossi, Laurino; Casini, Valentina; Gerardi, Viviana; Ascolani, Marta; Di Ruscio, Mirko; Casella, Giovanni; Savarino, Edoardo; Stradella, Davide; Pumpo, Rossella; Cortelezzi, Claudio Camillo; Daperno, Marco; Ciardo, Valeria; Nardone, Olga Maria; Caprioli, Flavio; Vitale, Giovanna; Cappello, Maria; Comberlato, Michele; Alvisi, Patrizia; Festa, Stefano; Campigotto, Michele; Bodini, Giorgia; Balestrieri, Paola; Viola, Anna; Pugliese, Daniela; Armuzzi, Alessandro; Saibeni, Simone; Fiorino, GionataFantini, Massimo Caludio; Biancone, Livia; Dragoni, Gabriele; Bezzio, Cristina; Miranda, Agnese; Ribaldone, Davide Giuseppe; Bertani, Angela; Bossa, Fabrizio; Allocca, Mariangela; Buda, Andrea; Mocci, Giammarco; Soriano, Alessandra; Guglielmi, Francesco William; Bertani, Lorenzo; Baccini, Flavia; Loddo, Erica; Privitera, Antonino Carlo; Sartini, Alessandro; Viscido, Angelo; Grossi, Laurino; Casini, Valentina; Gerardi, Viviana; Ascolani, Marta; Di Ruscio, Mirko; Casella, Giovanni; Savarino, Edoardo; Stradella, Davide; Pumpo, Rossella; Cortelezzi, Claudio Camillo; Daperno, Marco; Ciardo, Valeria; Nardone, Olga Maria; Caprioli, Flavio; Vitale, Giovanna; Cappello, Maria; Comberlato, Michele; Alvisi, Patrizia; Festa, Stefano; Campigotto, Michele; Bodini, Giorgia; Balestrieri, Paola; Viola, Anna; Pugliese, Daniela; Armuzzi, Alessandro; Saibeni, Simone; Fiorino, Gionat