NEW APPROACHES FOR VERY SHORT-TERM STEADY-STATE ANALYSIS OF AN ELECTRICAL DISTRIBUTION SYSTEM WITH WIND FARMS

Distribution networks are undergoing radical changes due to the high level of penetration of dispersed generation. Dispersed generation systems require particular attention due to their incorporation of uncertain energy sources, such as wind farms, and due to the impacts that such sources have on the planning and operation of distribution networks. In particular, the foreseeable, extensive use of wind turbine generator units in the future requires that distribution system engineers properly account for their impacts on the system. Many new technical considerations must be addressed, including protection coordination, steady-state analysis, and power quality issues. This paper deals with the very short-term, steady-state analysis of a distribution system with wind farms, for which the time horizon of interest ranges from one hour to a few hours ahead. Several wind-forecasting methods are presented in order to obtain reliable input data for the steady-state analysis. Both deterministic and probabilistic methods were considered and used in performing deterministic and probabilistic load-flow analyses. Numerical applications on a 17-bus, medium-voltage, electrical distribution system with various wind farms connected at different busbars are presented and discusse

Mobiliario en madera para viviendas sociales

Desde el inicio del trabajo se buscó aplicar los conocimientos sobre las propiedades de la madera de sauce para otorgarle mayor valor, debido a que es un recurso desaprovechado. Además, se intentó responder a las necesidades de los habitantes de viviendas sociales. A partir de esto, se tomaron problemas de los mobiliarios, como el uso intensivo y el desgaste diario, y otros inconvenientes vinculados a la madera, como la tendencia a torcerse y su flexibilidad. Se proyectó una familia de muebles compuesta por una mesa y sillas de comedor, una cama simple y otra matrimonial y un conjunto de muebles de guardado que pueden ubicarse en distintos espacios de la casa. Las sillas fueron planteadas como una monopieza. Se pensó en una estructura cerrada en la parte inferior que resalta la idea de durabilidad. Además, los encastres diseñados logran una buena resistencia.Trabajos de graduacion (Taller de Diseño Industrial V-A).Facultad de Bellas Arte

Voltage stability in unbalanced power systems: A new complementarity constraints-based approach

Voltage stability has become a fundamental issue in the new, liberalized markets due to the fact that the new power systems are approaching more and more the stability limits. Then, several approaches were proposed in the relevant literature to find the critical conditions and recently the problem was faced also with reference to unbalanced three phase power systems. The unbalances, in fact, can be responsible of more critical stability conditions than in balanced power systems. Continuation power flow and optimal power flows were applied to analyze such conditions. This paper deals with voltage stability analysis in unbalanced power systems and proposes a new optimization model to determine the critical point based on the use of complementarity constraints. Different formulations, with increasing complexity, of the optimization model are proposed and tested. In particular, the maximum stability margin is calculated by a single-stage or a multi-stage procedure that accounts for the relationship between the actual operating point and the maximum loading point. In addition, the multi-stage maximum stability margin problem is formulated also in a probabilistic framework to account for the uncertainties affecting the input data (e.g., load powers). An application is presented on a test system highlighting the feasibility and the goodness of the proposed technique. Both load and line unbalances are taken into account to capture the dependence of voltage stability on the level of unbalances

Operation of Plug-In Electric Vehicles for Voltage Balancing in Unbalanced Microgrids

The widespread use of distributed energy resources in the future electric distribution systems represents both a challenge and an opportunity for all the Smart Grid operators. Among these resources, plug-in electric vehicles are expected to play a significant role not only for the economic and environmental benefits they involve but also for the ancillary services they can provide to the supplying grid. This chapter deals with real-time operation of unbalanced microgrids including plug-in electric vehicles. The operation is achieved by means of an optimal control strategy aimed at minimizing the costs sustained for the energy provision while meeting various technical constraints. Among the technical constraints, the optimal control allows guaranteeing the satisfaction of power quality requirements such as the containment of slow voltage variations and the unbalance factors. Case studies are investigated in order to show the feasibility and the effectiveness of the proposed approach

How is who: evidence as clues for action in participatory sustainability science and public health research

Participatory and collaborative approaches in sustainability science and public health research contribute to co-producing evidence that can support interventions by involving diverse societal actors that range from individual citizens to entire communities. However, existing philosophical accounts of evidence are not adequate to deal with the kind of evidence generated and used in such approaches. In this paper, we present an account of evidence as clues for action through participatory and collaborative research inspired by philosopher Susan Haack’s theory of evidence. Differently from most accounts of evidence for use in policies and interventions, our account combines action-oriented (the how) and actors-oriented (the who) considerations. We build on Haack’s theory and on the analysis of examples of participatory and collaborative research in sustainability science and public health research to flesh out six procedural criteria for the generation and mobilization of evidence in and from participatory research. Action-oriented criteria invite to look at evidence from a (a) foundherentist, (b) gradational and (c) quasi-holistic perspective. Actors-oriented criteria point out that evidence generation and utilization are (d) social, (e) personal, and (f) embedded. We suggest that these criteria may reinforce participatory and collaborative approaches to evidence co-production when addressing complex problems in sustainability science and public health allowing for the generation of a kind of practical objectivity

Frequent detection of high human papillomavirus DNA loads in oral potentially malignant disorders

Human papillomavirus (HPV) is estimated to be the cause of 40-80% of the squamous cell carcinoma of the oropharynx but only of a small fraction of the oral cavity cancers. The prevalence of oral HPV infection has significantly increased in the last decade, raising concerns about the HPV role in progression of oral potentially malignant disorders (OPMD) toward squamous cell carcinomas. We sought to study HPV infection in patients with oral lesions, and in control individuals, using non-invasive and site-specific oral brushing and sensitive molecular methods. HPV DNA positivity and viral loads were evaluated in relation to patient data and clinical diagnosis. We enrolled 116 individuals attending Dental Clinics: 62 patients with benign oral lesions (e.g. fibromas, papillomatosis, ulcers) or OPMD (e.g. lichen, leukoplakia) and 54 controls. Oral cells were collected with Cytobrush and HPV-DNA detected with quantitative real-time PCR (qPCR) for the more common high-risk (HR) and low-risk (LR) genotypes. HPV detection rate, percentage of HR HPVs and HPV-DNA loads (namely HPV16 and in particular, HPV18) were significantly higher in patients than in controls. Lichen planus cases had the highest HPV positive rate (75.0%), hairy leukoplakia the lowest (33.3%). This study detected unexpectedly high rates of HPV infection in cells of the oral mucosa. The elevated HR HPV loads found in OPMD suggest the effectiveness of qPCR in testing oral lesions. Prospective studies are needed to establish whether elevated viral loads represent a clinically useful marker of the risk of malignant progression

Comunicazioni

The thirteenth volume of Comunicazioni dell’Istituto Papirologico «G. Vitelli» is divided, as was the previous one, into three sections: 1. Editions and rieditions of texts; 2. Critical notes; 3. Chronique de lexicographie papyrologique de la vie matérielle. In the first section there are texts which are being published for the first time or which are subject to a revision and a new edition, both belonging to various collections. This section also includes the exhibition of an exceptional artefact from the Arab period, belonging to the Papyrological Institute «G. Vitelli»’s collection. The second section includes three contributions with careful palaeographic and linguistic observations on literary and documentary texts, and a fourth contribution offering an exhaustive summary of the publication state of an archive from the Institute's collection. Lastly, the third section, as consolidated by the previous volume of the Comunicazioni, collects several findings of the international research project on the lexicography of material culture (Lex.Pap.Mat.), documented in the language of papyri

Mountain Information System: A Distributed E-Government Office

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