75 research outputs found

    ¿Qué opinan los docentes universitarios de su trabajo?

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    Póster presentado en: VIII Jornadas de Innovación Docente de la UBU, Burgos, 5 de abril de 2016, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

    Evaluation of load matching and grid interaction indexes of a net plus-energy house in Brazil with a hybrid PV system and demand-side management

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    This paper analyzes four scenarios of PV system configuration and proposes an optimized hybrid PV system size in order to improve Load Matching and Grid Interaction (LMGI) indicators, describing the yearly and daily variations of the indexes. A net plus-energy house is modeled in EnergyPlus under humid subtropical and dry tropical climates and electricity flows in the house and with the power grid are based on a high level battery controller simulated with different PV-battery sizes. An economic analysis is presented through two supporting schemes in order to perform analyses of Levelized Cost of Electricity (LCOE), grid parity and system payback time. The results demonstrated the combination of load-shifting demand-side management and small-scale PV-battery capacities provide improvements on building self-consumption and on the effects on the grid. The economic study indicates the building reaches better profitability under current Brazilian net-metering scheme in scenarios without batteries, reducing the payback time and LCOE sensibility analysis indicate the importance in reducing PV costs and to promote financial incentives

    Family communication and verbal child-to-parent violence among adolescents: The mediating role of perceived stress

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    In recent years, there has been an increase in the number of reported incidents of child-to-parent violence (CPV); however, this type of intra-family violence remains vastly understudied compared with other forms of family violence. The aim of this study is to analyze the relationship between family communication and verbal CPV through the mediation of adolescent perceived stress. The sample consisted of 2399 Spanish students of both genders between the ages of 11 and 20 years. Results show that problematic family communication is a risk factor for the presence of verbally abusive behavior towards parents, with a direct and indirect relationship through perceived stress. Open family communication is presented as a protective factor against verbally abusive behavior due to a negative relationship with perceived stress. Results point to a mediating role of perceived stress, which would explain the mechanism which links the quality of family communication to verbal violence towards parents. Implications of these results are discussed

    El engagement más esperado en educación superior: profesores y estudiantes comprometidos con el e-learning

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    Nowadays, it is essential for institutions of higher education to enhance the continuance commitment of users toward e-learning programs to promote and ensure the sustainability of those programs over time. The aim of this research is to identify the factors that might contribute to deepening user commitment toward e-learning systems from key agents’ perspectives (students and teachers). Information was collected from 146 students and 124 teachers participating in e-learning programs in higher education. The results showed that perceived organizational impact is the most important antecedent of continuance commitment. System quality had the highest impact on perceptions of organizational impact among both groups of users.The study showed the need for reconsideration of the role of instructor and system quality in the new educational paradigm, since both variables had no significant direct effect on the continuance commitment of users. This research shows managerial recommendations and directions for deepening commitment toward e-learning systems.Actualmente es esencial para las instituciones de educación superior fomentar un compromiso duradero de los usuarios hacia los programas de enseñanza online para promover y asegurar su sostenibilidad en el tiempo. El objetivo de este trabajo es identificar los factores que contribuyen a reforzar al compromiso del usuario con los sistemas de enseñanza online desde la perspectiva de los agentes implicados (estudiantes y profesores). Se recogió información de 146 estudiantes y 124 profesores que participan en programas universitarios de enseñanza online. Los resultados indican que el impacto organizacional percibido es el determinante más importante del compromiso temporal. La calidad del sistema muestra una gran influencia en las percepciones de compromiso organizacional en ambos grupos de usuarios. El estudio muestra la necesidad de reconsiderar el rol del profesor y de la calidad del sistema en este nuevo tipo de enseñanza, dado que ambas variables no muestran un efecto directo significativo en el compromiso temporal de los usuarios. Esta investigación permite derivar recomendaciones para la gestión y direcciones para generar compromiso hacia los sistemas de enseñanza online

    Serological and molecular survey of hepatitis E virus in cats and dogs in Spain

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    Hepatitis E virus (HEV) is an emerging zoonotic pathogen that is currently recognized as one of themajor causes of acute human hepatitis worldwide. In Europe, the increasing number of hepatitis E cases is mainly associated with the consumption of animal food products or contact with infected animals. Dogs and cats have been suggested as a zoonotic source of HEV infection. The aim of this study was to assess Orthohepevirus circulation, including HEV-A, HEV-B and HEV-C species, in sympatric urban cats and dogs in southern Spain. Between 2017 and 2020, blood samples were collected from 144 stray cats and 152 dogs, both strays and pets. The presence of antibodies againstHEV were tested using a double-antigen sandwich ELISA and seropositive simples were further analysed bywestern blot.ART-PCR was performed to detect RNAof Orthohepevirus species (HEV-A,HEV-B andHEV-C).Atotal of 19 (6.4%; 95%CI: 3.6-9.2) of the 296 animals tested showed anti-HEV antibodies by ELISA. Seropositivity was significantly higher in dogs (9.9%; 15/152; 95%CI: 5.1-14.6) than in cats (2.8%; 4/144; 95%CI: 0.1-5.5). Ten of the 18 ELISA-positive animals that could be further analysed by western blot, reacted against HEV-3 and/or HEV-C1 antigens, which suggest circulation of both genotypes in urban cats and dogs in the study area. However, HEV-A, HEV-B and HEV-C RNA were not detected in any of the tested sera. This is the first study to assess HEV circulation in both stray cats and dogs in Europe. Our results provide evidence of HEV exposure in sympatric urban cat and dog populations in southern Spain. Further studies are needed to determine the role of these species in the epidemiology of HEV

    Optimizing PV use through active demand side management

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    With recent technological developments within the field of power conditioning and the progressive decrease of incentives for PV electricity in grid-connected markets, new operation modes for PV systems should be explored beyond the traditional maximization of PV electri city feed-in. An example can be found in the domestic sector, where the use of modern PV hybrid systems combin ed with efficient electrical appliances and demand side management strategies can significantly enhance the PV value for the user. This paper presents an active demand side management system able to displace the consumer’s load curve in response to local (PV hybrid system, user) and external conditions (external grid). In this way, th e consumer becomes an “active consumer” that can also cooperate with others and the grid, increasing even more the PV value for the electrical system

    Self-consumption enhancement with storage system and demand-side management: GeDELOS-PV system.

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    Because of the recent technological developments within the field of power conditioning and the progressive decrease of incentives for PV electricity in grid-connected markets, new operation modes for PV systems should be explored beyond the traditional maximization of PV electricity feed-in. We have developed the GeDELOS-PV system as an example of added value for PV electricity which arises from the combination of modern hybrid PV technology with a lead-acid battery storage system and Demand Side Management strategies in the residential sector. We carry out simulations for long-time experiments (yearly studies) and real measurements for short and mid-time experiments (daily and weekly studies). Results show that the relationship between electricity flows and storage capacity is not linear and therefore, it becomes an important design criterio

    Improving photovoltaics grid integration through short time forecasting and self-consumption

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    The uncertainty associated to the forecast of photovoltaic generation is a major drawback for the widespread introduction of this technology into electricity grids. This uncertainty is a challenge in the design and operation of electrical systems that include photovoltaic generation. Demand-Side Management (DSM) techniques are widely used to modify energy consumption. If local photovoltaic generation is available, DSM techniques can use generation forecast to schedule the local consumption. On the other hand, local storage systems can be used to separate electricity availability from instantaneous generation; therefore, the effects of forecast error in the electrical system are reduced. The effects of uncertainty associated to the forecast of photovoltaic generation in a residential electrical system equipped with DSM techniques and a local storage system are analyzed in this paper. The study has been performed in a solar house that is able to displace a residential user?s load pattern, manage local storage and estimate forecasts of electricity generation. A series of real experiments and simulations have carried out on the house. The results of this experiments show that the use of Demand Side Management (DSM) and local storage reduces to 2% the uncertainty on the energy exchanged with the grid. In the case that the photovoltaic system would operate as a pure electricity generator feeding all generated electricity into grid, the uncertainty would raise to around 40%

    Energy Refurbishment of an Office Building with Hybrid Photovoltaic System and Demand-Side Management

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    On-site photovoltaic (PV) and battery systems intend to improve buildings energy performance, however battery costs and monetary incentives are a major drawback for the introduction of these technologies into the electricity grids. This paper proposes an energy refurbishment of an office building based on multi-objective simulations. An innovative demand-side management approach is analyzed through the PV and battery control with the purpose of reducing grid power peaks and grid imported energy, as well as improving the project economy. Optimization results of load matching and grid interaction parameters, complemented with an economic analysis, are investigated in different scenarios. By means of battery use, the equivalent use of the grid connection is reduced by 12%, enhancing the grid interaction potential, and 10% of load matching rates can be increased. Project improvements indicate the grid connection capacity can be reduced by 13% and significant savings of up to 48% are achieved on yearly bills. The economy demonstrates the grid parity is only achieved for battery costs below 100  /kWh and the payback period is large: 28 years. In the case with only PV system, the grid parity achieves better outcomes and the payback time is reduced by a half, making this a more attractive option

    Self-consumption of PV electricity with active demand side management: The GEDELOS-PV system

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    Because of the recent technological developments within the field of power conditioning and the progressive decrease of incentives for PV electricity in grid-connected markets, new operation modes for PV systems should be explored beyond the traditional maximization of PV electricity feed-in. We have developed the GeDELOS-PV system as an example of added value for PV electricity which arises from the combination of modern hybrid PV technology with a lead-acid battery storage system and Demand Side Management strategies in the residential sector. We carry out simulations for long-time experiments (yearly studies) and real measurements for short and mid-time experiments (daily and weekly studies). Results show that the relationship between electricity flows and storage capacity is not linear and therefore, it becomes an important design criterion.
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