Identification of harmonic current sources in single-phase power systems using feature selection techniques and artificial neural networks

Este trabalho consiste em apresentar um método para a identificação de cargas lineares e não-lineares comumente encontradas em sistemas elétricos residenciais. Desta identificação, soluções viáveis poderão ser aplicadas com o intuito de mitigar os níveis de emissão das correntes harmônicas geradas, advindas principalmente por cargas com características não-lineares. No desenvolvimento do método, utilizaram-se de técnicas para a seleção de atributos, de forma a minimizar a dificuldade em se identificar as cargas conectadas ao sistema. A etapa posterior de identificação foi realizada pela aplicação de redes neurais artificiais. Todas as situações de distorção harmônica foram geradas em laboratório por uma fonte de alimentação, onde em sua saída foram alocados analisadores de energia, responsáveis pela extração das medidas necessárias sobre as cargas residenciais em análise. Os resultados obtidos foram considerados satisfatórios, mostrando-se que a metodologia proposta pode ser também empregada pelas concessionárias de energia elétrica para que estas obtenham informações sobre o perfil das cargas instaladas em consumidores residenciais.This work presents a method to identify linear and nonlinear loads commonly encountered in residential electrical systems. From this method, feasible solutions can be applied to mitigate the high levels of harmonic currents, generated mainly by nonlinear loads. Techniques of feature selection were used to data preprocessing and to minimize the effort in identification of loads connected to the electrical system. For the next step, the load identification, artificial neural networks were applied. All harmonic distortion situations were created in laboratory from a power source, and in its outputs were inserted the loads and power quality analyzers, which perform the extraction of all measurements. The obtained results were considered satisfactory, which show that the methodology can be employed by power distribution companies in order to obtain information about the profile of loads used by residential consumers.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Voltage regulation in power distribution substation transformer using fuzzy implementation

Este trabalho apresenta um controlador fuzzy para realizar o ajuste automático de tensão em transformadores de subestação de distribuição de energia elétrica. Tal controle atuará em tempo-real nos transformadores dotados de comutadores de tap sob carga. O sistema inteligente foi empregado para tornar o relé regulador de tensão adaptativo. Ainda como foco do estudo, pretende-se atuar apenas na subestação de distribuição, realizando medições no barramento secundário e implementando ações de controle também neste barramento. A capacidade dos sistemas fuzzy em tratar incertezas, assim como sua habilidade em interpretar informações qualitativas, permitiu a formulação de uma estratégia de controle de tensão que atende a todas as regulamentações dos órgãos fiscalizadores brasileiros e, também, os anseios das concessionárias de distribuição frente aos aspectos relacionados com a qualidade de energia, pois os resultados obtidos foram bem satisfatórios.A fuzzy controller is introduced in this paper in order to make the voltage adjustment in power distribution substation transformer. The real-time controller in each case would act on power transformers equipped with under-load tap changers. Learning systems are employed to turn the voltage-control relays into adaptive devices. The scope of the present study has been limited to the power distribution substation, and both the voltage measurements and control actions are carried out on the secondary bus. The capacity of fuzzy systems to handle approximate data, together with their unique ability to interpret qualitative information, make it possible to design voltage control strategies that satisfy both the requirements of the Brazilian regulatory bodies and the real concerns of the electric power distribution companies in relation to the aspects involved with power quality, since the test results were highly satisfactory.FAPES

Evidence mapping based on systematic reviews of therapeutic interventions for soft tissue sarcomas

Soft tissue sarcomas are a heterogeneous group of rare tumours of mesenchymal origin. Evidence mapping is one of the most didactic and friendly approaches to organise and summarise the range of research activity in broad topic fields. The objective of this evidence mapping is to identify, describe and organise the current available evidence about therapeutic interventions on soft tissues sarcomas. We followed the methodology of global evidence mapping. We performed a search of the PubMed, EMBASE, The Cochrane Library and Epistemonikos to identify systematic reviews (SRs) with or without meta-analyses published between 1990 and March 2016. Two independent literature reviewers assessed eligibility and extracted data. Methodological quality of the included systematic reviews was assessed using AMSTAR. We organised the results according to identified PICO questions and used tables and a bubble plot to display the results. The map is based on 24 SRs that met eligibility criteria and included 66 individual studies. Three-quarters were either observational or uncontrolled clinical trials. The quality of the included SRs was in general moderate or high. We identified 64 PICO questions from them. The corresponding results mostly favoured the intervention arm. This evidence mapping was built on the basis of SRs, which mostly included non-experimental studies and were qualified by the AMSTAR tool as of moderate quality. The evidence mapping created from PICO questions is a useful approach to describe complex and huge clinical topics through graphical media and orientate further research to fulfil the existing gaps. However, it is important to delimitate the steps of the evidence mapping in a pre-established protocol

Profiling the circulating miRnome reveals a temporal regulation of the bone injury response

Bone injury healing is an orchestrated process that starts with an inflammatory phase followed by repair and remodelling of the bone defect. The initial inflammation is characterized by local changes in immune cell populations and molecular mediators, including microRNAs (miRNAs). However, the systemic response to bone injury remains largely uncharacterized. Thus, this study aimed to profile the changes in the plasma miRnome after bone injury and determine its biological implications. Methods: A rat model of femoral bone defect was used, and animals were evaluated at days 3 and 14 after injury. Non-operated (NO) and sham operated animals were used as controls. Blood and spleen were collected and peripheral blood mononuclear cells (PBMC) and plasma were separated. Plasma miRnome was determined by RT-qPCR array and bioinformatics Ingenuity pathway analysis (IPA) was performed. Proliferation of bone marrow mesenchymal stem/stromal cells (MSC) was evaluated by Ki67 staining and high-throughput cell imaging. Candidate miRNAs were evaluated in splenocytes by RT-qPCR, and proteins found in the IPA analysis were analysed in splenocytes and PBMC by Western blot. Results: Bone injury resulted in timely controlled changes to the miRNA expression profile in plasma. At day 3 there was a major down-regulation of miRNA levels, which was partially recovered by day 14 post-injury. Interestingly, bone injury led to a significant up-regulation of let-7a, let-7d and miR-21 in plasma and splenocytes at day 14 relative to day 3 after bone injury, but not in sham operated animals. IPA predicted that most miRNAs temporally affected were involved in cellular development, proliferation and movement. MSC proliferation was analysed and found significantly increased in response to plasma of animals days 3 and 14 post-injury, but not from NO animals. Moreover, IPA predicted that miRNA processing proteins Ago2 and Dicer were specifically inhibited at day 3 post-injury, with Ago2 becoming activated at day 14. Protein levels of Ago2 and Dicer in splenocytes were increased at day 14 relative to day 3 post-bone injury and NO animals, while in PBMC, levels were reduced at day 3 (albeit Dicer was not significant) and remained low at day 14. Ephrin receptor B6 followed the same tendency as Ago2 and Dicer, while Smad2/3 was significantly decreased in splenocytes from day 14 relative to NO and day 3 post-bone injury animals. Conclusion: Results show a systemic miRNA response to bone injury that is regulated in time and is related to inflammation resolution and the start of bone repair/regeneration, unravelling candidate miRNAs to be used as biomarkers in the monitoring of healthy bone healing and as therapeutic targets for the development of improved bone regeneration therapies.This work was funded by project NORTE-01-0145-FEDER-000012, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and AO Foundation-Switzerland (project S-15-83S). AMS, MIA, CC and JHT were supported by FCT-Fundação para a Ciência e a Tecnologia, through fellowships SFRH/BD/ 85968/2012, SFRH/BPD/91011/2012, SFRH/BDP/ 87071/2012 and SFRH/BD/112832/2015, respecttively. Work in Dr. Calin's laboratory is supported by National Institutes of Health (NIH/NCATS) grant UH3TR00943-01 through the NIH Common Fund, Office of Strategic Coordination (OSC), the NIH/NCI grant 1R01CA182905-01, a U54 grant-UPR/MDACC Partnership for Excellence in Cancer Research 2016 Pilot Project, a Team DOD (CA160445P1) grant, a Ladies Leukemia League grant, a CLL Moonshot Flagship project, a SINF 2017 grant, and the Estate of C. G. Johnson, J

Strengthening the Magnetic Interactions in Pseudobinary First-Row Transition Metal Thiocyanates, M(NCS)2.

Understanding the effect of chemical composition on the strength of magnetic interactions is key to the design of magnets with high operating temperatures. The magnetic divalent first-row transition metal (TM) thiocyanates are a class of chemically simple layered molecular frameworks. Here, we report two new members of the family, manganese(II) thiocyanate, Mn(NCS)2, and iron(II) thiocyanate, Fe(NCS)2. Using magnetic susceptibility measurements on these materials and on cobalt(II) thiocyanate and nickel(II) thiocyanate, Co(NCS)2 and Ni(NCS)2, respectively, we identify significantly stronger net antiferromagnetic interactions between the earlier TM ions-a decrease in the Weiss constant, θ, from 29 K for Ni(NCS)2 to -115 K for Mn(NCS)2-a consequence of more diffuse 3d orbitals, increased orbital overlap, and increasing numbers of unpaired t2g electrons. We elucidate the magnetic structures of these materials: Mn(NCS)2, Fe(NCS)2, and Co(NCS)2 order into the same antiferromagnetic commensurate ground state, while Ni(NCS)2 adopts a ground state structure consisting of ferromagnetically ordered layers stacked antiferromagnetically. We show that significantly stronger exchange interactions can be realized in these thiocyanate frameworks by using earlier TMs.EPSRC NPIF 2018 fund Laboratory Directed Research and Development Program of Oak Ridge National Laboratory NSERC of Canada PGSD fund Trinity College, Cambridge School of Chemistry, University of Nottingham Hobday Fellowship EPSRC Strategic Equipment Grant EP/M000524/