Caracterización de una bomba de calor fotovoltaica con conexión a la red eléctrica para generación de frío

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este artículo describe los resultados de la caracterización técnica de un prototipo de bomba de calor fotovoltaica (BC-FV) hibridada con la red eléctrica, para aplicaciones de generación de frío para climatización de espacios. Esta caracterización se ha realizado con un algoritmo de control “inverter”, caracterizado por regular la frecuencia del compresor de la BC para mantener una temperatura de consigna en la habitación. Se han efectuado dos ensayos para dos temperaturas de consigna de 18 ºC y 24 ºC. Se han calculado indicadores de rendimiento del generador FV -PR, PRPV,CEM y 3 factores de utilización-, de la BC -EER y SPF- y de todo el conjunto del sistema -SFFV y SPFBC-FV,CEM, que se obtienen combinando todos los anteriores-. Los resultados muestran un buen comportamiento de los componentes del sistema. La calidad del acoplamiento entre ellos viene determinada fundamentalmente por el aprovechamiento del generador FV por parte del compresor que, a su vez, depende del dimensionado y de la temperatura de consigna establecida.ABSTRACT: This paper presents the results of the technical characterization of a photovoltaic heat pump (PV-HP) prototype connected to the electric grid, for space cooling applications. This characterization has been performed for an “inverter” control that regulates the frequency of the compressor for maintaining a certain temperature set point. Two test have been implemented for two different temperature set points, 18 ºC and 24 ºC. Several performance indicators have been calculated for the PV generator -PR, PRPV,CEM y 3 utilization ratios-, for the HP unit -EER y SPF- and for the whole system -SFFV y SPFBC-FV,CEM, which is obtained as a combination of all the others-. The results show a good performance of the system components. The quality of the coupling between them mosthly depends on the utilization of the PV generator, that is determined by the sizing of these components and by the temperature set point value.info:eu-repo/semantics/publishedVersio

Simulación de sistemas de riego hibridos FV-RED: aplicación a riego directo

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Este artículo presenta la metodología utilizada en una herramienta de simulación de la productividad de sistemas de riego híbridos fotovoltaico-red, así como su aplicación a un sistema de riego directo en Marrakech, Marruecos. Se trata de una finca de olivar intensivo, cuyas necesidades de riego son 8 horas diarias entre marzo y octubre. La aportación fotovoltaica en ese periodo es de 1456 kWh/kWp, mientras que la red eléctrica tiene que aportar 66 kWh/kWp. Entre los meses de noviembre y febrero toda la energía fotovoltaica es desaprovechada (550 kWh/kWp) puesto que no se riega. Con el objetivo de generalizar el estudio, se analiza la influencia de las necesidades de riego diarias en la aportación FV mediante cuatro simulaciones adicionales para necesidades de riego diarias de 4 h, 10 h, 12 h y 16 h. Por ejemplo, en el mes de junio, y considerando 4 h de riego al día, la aportación FV es 104 kWh/kWp (cuando para las 8 h es 185 kWh/kWp), llegando a 239 kWh/kWp a partir de las 12 h de riego al día.ABSTRACT: This article explains the methodology used in a hybrid photovoltaic-grid irrigation system simulation tool, as well its application to a direct pumping system in Marrakech, Morocco. It is an intensive olive tree cultivation, with a daily irrigation need of 8 hours between March and October. The photovoltaic energy used in this period is 1456 kWh/kWp, while the grid electricity consumption is 66 kWh/kWp. Between November and February, the photovoltaic energy is wasted (550 kWh/kWp). To evaluate the influence of the irrigation needs in terms of the number of irrigation hours per day, four additional simulations were performed – for 4 h, 10 h, 12 h, and 16 h. For example, in June, and considering 4 h of irrigation per day, the photovoltaic energy used is 104 kWh/kWp (while it is 185 kWh/kWp for 8 hours), achieving 239 kWh/kWp from 12 hours of irrigation per day.info:eu-repo/semantics/publishedVersio

Epidemiological situation of bovine brucellosis in the State of Bahia, Brazil

O trabalho consistiu em estratificar o Estado da Bahia em quatro regiões com características homogêneas (circuitos produtores) para que fossem amostradas aleatoriamente, em cada uma delas, 300 propriedades. Em cada propriedade foram escolhidas, de forma aleatória, 10 a 15 fêmeas bovinas adultas, das quais foi obtida uma amostra de sangue. No total, foram amostrados 10.816 animais, provenientes de 1.413 propriedades. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado (Rosa Bengala) e a confirmação dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal reagiu às duas provas sorológicas. As prevalências de focos e a de fêmeas adultas soropositivas do Estado foram de 4,2% [3,1-5,3%] e 0,66% [0,41-0,93%], respectivamente. Para os circuitos produtores foram: circuito 1, 5,8% [3,6-8,7%] e 0,86% [0,41-1,3%]; circuito 2, 3,1% [1,5-5,6%] e 1,2% [0,25-2,1%]; circuito 3, 6,3% [4,0-9,3%] e 1,7% [0,66-2,7%]; e circuito 4, 0,60% [0,07-2,2%] e 0,07 [0,00-0,21%]. Para a análise de fatores de riscos associados à doença foi aplicado um questionário epidemiológico em cada propriedade visitada. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: compra de reprodutores (OR= 2,27) e presença de áreas alagadiças (OR= 1,76). A vacinação de fêmeas de três até oito meses de idade foi um fator de proteção (OR= 0,53). ____________________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological situation of bovine brucellosis in the State of Bahia was carried out in 2004. The State was divided into four similar production regions, 300 herds were randomly sampled in each region, and 10 to 15 adult bovine females were sampled in each of these herds. A total of 10,816 serum samples from 1,413 herds were collected. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal Test (RBT), and all RBT-positive sera were re-tested by the 2-mercaptoethanol test (2-ME) for confirmation. A herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalence of infected herds and seropositive adult bovine females in Bahia State were: 4.2% [3.1-5.3%] and 0.66% [0.41-0.93%], respectively. In the production regions, prevalence of infected herds and animals were, respectively: region 1, 5.8% [3.6-8.7%] and 0.86% [0.41-1.3%]; region 2, 3.1% [1.5-5.6%] and 1.2% [0.25-2.1%]; region 3, 6.3% [4.0-9.3%] and 1.7% [0.66-2.7%]; and region 4, 0.60% [0.07-2.2%] and 0.07%[0.00-0.2%]. In each herd, an epidemiological questionnaire was applied. The risk factors (odds ratio, OR) associated with the presence of the infection were: purchase of breeding animals (OR = 2.27) and presence of flood areas (OR= 1.76). Vaccination of heifers from three to eight months of age was a protective factor (OR=0.53)

Epidemiological situation of bovine brucellosis in the State of Rio Grande do Sul, Brazil

Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina. O Estado foi dividido em sete regiões. Em cada região foram amostradas aleatoriamente cerca de 300 propriedades, e dentro dessas foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total foram amostrados 16.072 animais, provenientes de 1.957 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração e as práticas zootécnicas e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal foi reagente às duas provas sorológicas. Para o Estado, as prevalências de focos e de animais infectados foram, respectivamente, 2,1% [1,5-2,6%] e 1,0% [0,60-1,4%]. Para os circuitos, a prevalência de focos e a de animais foram, respectivamente: circuito 1, 3,1% [1,4-5,7%] e 0,95% [0,0-2,0%]; circuito 2, 7,7% [4,9-11,3%] e 1,0% [0,40-1,7%]; circuito 3, 5,7% [3,4-8,8%] e 2,1% [0,41-3,8%]; circuito 4, 0,66% [0,08-2,4%] e 0,66% [0,0-1,8%]; circuito 5, 0,66% [0,08-2,4%] e 0,05% [0,0-0,13%]; circuito 6, 0,0% [0,0-1,3%] e 0,0% [0,0-0,25%]; circuito 7, 5,4% [2,5-10,1%] e 2,9% [0,49-5,3%]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: exploração de corte (OR= 4,27 [1,82-10,01]) e histórico de aborto (OR=3,27,1,71-6,25]). ____________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological status of bovine brucellosis was carried out in the State of Rio Grande do Sul. The State was divided in seven regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 16,072 serum samples from 1,957 herds, were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test and all positive sera were re-tested by the 2-mercaptoethanol test. The herd was considered positive if at least one animal was positive on both tests. The prevalences of infected herds and animals in the State were, respectively 2.1% [1.5-2.6%] and 1.0% [0.60-1.4%]. In the regions, the prevalences of infected herds and animals were, respectively: region 1, 3.1% [1.4-5.7%] and 0.95% [0.0-2.0%]; region 2, 7.7% [4.9-11.3%] and 1.0% [0.40-1.7%]; region 3, 5.7% [3.4-8.8%] and 2.1% [0.41-3.8%]; region 4, 0.66% [0.08-2.4%] and 0.66% [0.0-1.8%]; region 5, 0.66% [0.08-2.4%] and 0.05% [0.0-0.13%]; region 6, 0.0% [0.0-1.3%] and 0.0% [0.0-0.25%]; and region 7, 5.4% [2.5-10.1%] and 2.9% [0.49-5.3%]. The risk factors (odds ratio, OR) associated with the presence of infection were: beef herd (OR= 4.27 [1.82-10.01]) and recent history of abortion (OR= 3.27-1.71-6.25])

Portuguese Ministers, 1851-1999: Social Background and Paths to Power

Disponível em: http://193.136.113.6/Opac/Pages/Search/Results.aspx?SearchText=UID=bb8aa8d5-c6b6-466a-81bb-fe8a67693cee&DataBase=10449_UNLFCSHThis paper provides an empirical analysis of the impact of regime changes in the composition and patterns of recruitment of the Portuguese ministerial elite throughout the last 150 years. The ‘out-of-type’, violent nature of most regime transformations accounts for the purges in and the extensive replacements of the political personnel, namely of the uppermost officeholders. In the case of Cabinet members, such discontinuities did not imply, however, radical changes in their social profile. Although there were some significant variations, a series of salient characteristics have persisted over time. The typical Portuguese minister is a male in his midforties, of middle-class origin and predominantly urban-born, highly educated and with a state servant background. The two main occupational contingents have been university professors - except for the First Republic (1910-26) - and the military, the latter having only recently been eclipsed with the consolidation of contemporary democracy. As regards career pathways, the most striking feature is the secular trend for the declining role of parliamentary experience, which the democratic regime did not clearly reverse. In this period, a technocratic background rather than political experience has been indeed the privileged credential for a significant proportion of minister

Membrane adsorber for endotoxin removal

ABSTRACT The surface of flat-sheet nylon membranes was modified using bisoxirane as the spacer and polyvinyl alcohol as the coating polymer. The amino acid histidine was explored as a ligand for endotoxins, aiming at its application for endotoxin removal from aqueous solutions. Characterization of the membrane adsorber, analysis of the depyrogenation procedures and the evaluation of endotoxin removal efficiency in static mode are discussed. Ligand density of the membranes was around 7 mg/g dry membrane, allowing removal of up to 65% of the endotoxins. The performance of the membrane adsorber prepared using nylon coated with polyvinyl alcohol and containing histidine as the ligand proved superior to other membrane adsorbers reported in the literature. The lack of endotoxin adsorption on nylon membranes without histidine confirmed that endotoxin removal was due to the presence of the ligand at the membrane surface. Modified membranes were highly stable, exhibiting a lifespan of approximately thirty months