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The avian bill is finely adjusted to foraging ecology and, as part of the vocal tract, it may also affect sexual signals such as songs. Acoustic theory predicts that larger bills lower the resonant frequency of vocal tracts, allowing larger-billed species to emphasize lower sound frequencies. Theory also predicts that identical changes in bill gape allow singing over a wider frequency bandwidth in larger-billed species. We tested these associations between bill size and sound frequencies of song, controlling for body mass, across ca. 1000 taxonomically-diverse passerines. Phylogenetically informed analyses indicated that both bill and body sizes are negatively related to the sound frequency of songs, with additive effects of similar strength. Analyses of reduced datasets, to decrease bill-body size associations, indicated that the effect of bill size remains identical and is thus not an artefact of its covariation with body size. Sound frequency bandwidth was only related to body size but not bill size, perhaps because large bills may allow greater modulation of frequency but also hinder fast bill movement. Since the bill has a major role explaining species differences in birdsong sound frequency, it can be a magic trait that promotes reproductive isolation as a consequence of ecological divergence.

Carotenoid-based colour signals can be costly to produce and maintain, and trade-offs between signalling and other fitness traits are expected. In mutually ornamented species, trade-offs with reproduction may be stronger for females than males, because females often dedicate more resources to offspring production, which may lead to plastic investment in colour signals and plastic sexual dichromatism. Oestradiol is a candidate mediator of this trade-off because it regulates reproductive physiology and may also influence the expression of coloration. We tested this hypothesis by giving female common waxbills ( Estrilda astrild ) either oestradiol (17β-oestradiol) or empty implants during the early breeding season and measured spectral reflectance of carotenoid-based bill coloration weekly for two months. Using a model of avian vision, we found that bill colour in oestradiol-implanted females became less saturated, less red in hue and brighter, compared with control females and with unimplanted males. This resulted in a change in bill sexual dichromatism from imperceptible to perceptible. Results support the hypothesis that female reproductive physiology influences investment in coloration through changes in oestradiol and show a form of female-driven plastic sexual dichromatism. Greater sensitivity of female colour to physiological and/or environmental conditions helps explain why differences in sexual dichromatism among species differing in ecology often evolve owing to changes in female rather than male phenotype.

Neste trabalho foi estudada a origem de dois tipos de defeitos que ocorriam em canecas de grés obtidas por prensagem isostática e monocozedura. Ambos os tipos de defeitos correspondiam a depressões localizadas e profundas na superfície do vidrado após a cozedura e ocorriam preferencialmente em peças produzidas com o vidrado BS. Verificou-se que a localização dos defeitos do tipo I coincidia com crateras na camada de vidrado geradas durante a etapa de vidragem. Pelo contrário, os defeitos do tipo II apenas eram visíveis após a cozedura das peças. O estudo envolveu a caracterização dos materiais utilizados no fabrico das canecas e um conjunto de ensaios que permitiram identificar a origem dos defeitos e propor ações corretivas para a sua mitigação. No caso dos defeitos do tipo I, os resultados obtidos permitiram concluir que as depressões resultavam da retenção de bolhas de ar durante a vidragem, devido a uma velocidade excessiva de formação da camada de vidrado. Por seu lado, os defeitos do tipo II estavam associados à presença de um resíduo resultante do esponjamento automático das peças. Em ambos os casos, a fusibilidade insuficiente do vidrado BS dificultava a retificação das depressões resultantes durante a etapa de cozedura. A eliminação praticamente completa dos defeitos foi conseguida através do ajuste das condições de vidragem (defeitos do tipo I) e das condições de operação do sistema de acabamento automático (defeitos do tipo II). In this work, the origin of two types of defects that occurred in stoneware mugs obtained by isostatic pressing and single firing was studied. Both types of defects corresponded to localized and deep depressions on the surface of the glaze after firing and occurred preferentially in pieces produced with the BS glaze. It was found that the location of type I defects coincided with craters in the glaze layer generated during the glazing step. By contrast, the type II defects were only visible after the pieces had been fired. The study involved the characterization of the materials used in the production of the mugs and a set of tests that made it possible to identify the origin of the defects and propose corrective actions for their mitigation. In the case of type I defects, the results obtained allowed to conclude that the depressions resulted from the air bubbles trapped during the glazing, due to an excessive speed of formation of the glaze layer. On the other hand, type II defects were associated to the presence of a residue resulting from the automatic sponging of the mugs. In both cases, the insufficient fusibility of the BS glaze made it difficult to rectify the resulting depressions during the firing step. The virtually complete elimination of defects was achieved by adjusting the glazing conditions (type I defects) and the operating conditions of the automatic finishing system (type II defects). Mestrado em Engenharia de Materiais

The dopaminergic (DAergic) system has well-known influences on behavioral and cognitive functions. Previous work with common waxbills (Estrilda astrild) reported context-specific DAergic effects that could have been due to social environment. Manipulating the dopamine D2-like receptor family (D2R) pathways had opposing effects on behavior depending on whether waxbills were tested alone or in a small cage with a mirror as a social stimulus. As waxbills are highly gregarious, it was hypothesized that being alone or perceiving that they have a companion might explain this context dependence. To test context-dependent DAergic effects, we compared behavioral effects of D2R manipulation in waxbills in the same familiar environment, but either alone or with a familiar, same-sex companion. We found that D2R agonism decreased movement and feeding, similar to previous results when testing waxbills alone. However, contrary to the hypothesis of dependence on social context, we found that the behavioral effects of the D2R agonist were unchanged when waxbills were tested with a companion. The context dependence reported earlier might thus be due to other factors, such as the stress of being in a novel environment (small cage) or with an unfamiliar social stimulus (mirror image). In tests with a companion, we also found a sex-specific social effect of D2R manipulation: D2R blocking tended to decrease aggression in males but to increase it in females. Together with past work, our results suggest that DAergic effects on behavior involve different types of context or sex dependence.

We explore how commodity objects and technologies can be repurposed to provide a multimodal programming environment that is accessible to children with visual impairments, flexible, and scalable to a variety of programming challenges. Our approach resorts to four main components: 1) a LEGO base plate where LEGO blocks can be assembled to create maps, which is flexible and robust for tactile recognition; 2) a tangible programming area where LEGOs, with 3D printed caps enriched with tactile icons, can be assembled to create a program; 3) alternatively, the program can be created through a voice dialogue; and 4) a low-cost OzoBot Bit. A preliminary study with educators suggests that the approach could be useful to a variety of developmental stages, is accessible and stimulating, and promising for CT training.

In a healthy athlete, the caloric intake is sufficient for sports energy needs and body physiological functions, allowing a balance between energy availability, bone metabolism, and menstrual cycle. On the other hand, an imbalance caused by low energy availability due to a restrictive diet, eating disorders or long periods of energy expenditure leads to multisystemic deregulation favoring the essential functions of the body. This phenomenon, described as the female athlete triad, occurs in a considerable percentage of high-performance athletes, with harmful consequences for their future. The present review was carried out based on a critical analysis of the most recent publications available and aims to provide a global perception of the topic relative energy deficit in sport (RED-S). The objective is to promote the acquisition of more consolidated knowledge on an undervalued theme, enabling the acquisition of preventive strategies, early diagnosis and/or appropriate treatment.Em uma atleta saudável, o aporte calórico é suficiente para a necessidade energética esportiva e para as funções fisiológicas corporais, permitindo um equilíbrio entre disponibilidade energética (DE), metabolismo ósseo e função menstrual. Por outro lado, um desequilíbrio devido à baixa disponibilidade energética (BDE) por dieta restritiva, perturbações alimentares ou grandes períodos de gasto energético conduz a uma desregulação multissistêmica priorizando as funções essenciais do corpo. Este fenômeno, descrito inicialmente como tríade da mulher atleta e, atualmente, como défice energético relativo no esporte (RED-S, na sigla em inglês) tem como pilares a BDE, disfunção menstrual e alterações na densidade mineral óssea (DMO), estando presente em uma percentagem considerável de atletas de alta competição, com consequências nefastas para o seu futuro a curto, médio e longo prazo. A presente revisão foi realizada a partir da análise crítica das publicações mais recentes disponíveis e pretende proporcionar uma percepção global do tema RED-S. O objetivo é promover a aquisição de um conhecimento mais consolidado sobre uma temática subvalorizada, possibilitando a aquisição de estratégias preventivas, diagnóstico precoce e/ou tratamento adequado.

Introduction: The CAD-RADSTM classification was recently introduced in an attempt to standardize coronary computed tomography angiography (CCTA) reports and to provide recommendations for further management. The aim of this study was to assess how additional cardiac investigations were being ordered before the introduction of the CAD-RADS classification in a tertiary hospital's CCTA reports. Methods: We conducted a single-center retrospective analysis of 200 patients (103 women, mean age 59±13 years) who underwent CCTA for suspected or known coronary artery disease prior to the systematic introduction of the CAD-RADS classification in the reports. For each case, we assessed whether further cardiac investigation was requested after CCTA and what type of test was performed (functional testing, invasive coronary angiography or viability testing). Results: The majority of patients (n=158; 79%) were classified as CAD-RADS 0-2. In patients with lower (0-2) or higher (4 or 5) scores, further testing was in accordance with CAD-RADS recommendations in 98% of cases (n=168). In patients with CAD-RADS 3 (intermediate stenosis), functional testing was requested as recommended in only 36% of cases (n=5), while 50% (n=7) proceeded directly to invasive coronary angiography. In patients in whom CCTA was non-diagnostic, most did not undergo further cardiac investigation. Conclusion: In patients with CAD-RADS classifications at the ends of the spectrum, additional cardiac investigation after CCTA was almost always in accordance with the recommendations. However, in patients with intermediate scores, invasive coronary angiography prevailed over functional testing. Resumo: Introdução: A classificação CAD-RADS® foi recentemente introduzida com o objetivo de padronizar os relatórios da AngioTC coronária e fornecer recomendações sobre a investigação futura. O objetivo deste trabalho foi avaliar qual o tipo de investigação cardíaca adicional solicitada antes da introdução da classificação CAD-RADS® nos relatórios de AngioTC coronária de um hospital terciário. Métodos: Análise retrospetiva de centro único em que foram avaliados 200 doentes (103 mulheres, idade média 59±13 anos) que realizaram AngioTC por suspeita ou avaliação de doença coronária, antes da introdução sistemática da classificação CAD-RADS® nos relatórios. Em cada caso avaliou-se se foi realizada investigação cardíaca adicional após a AngioTC e qual o tipo de exame requisitado (avaliação funcional de isquemia, angiografia coronária invasiva ou teste de viabilidade). Resultados: A maioria dos doentes (n = 158; 79%) foram classificados como CAD-RADS® 0 - 2. Nos doentes com pontuação mais baixa (0-1) ou mais elevada (4-5), a investigação realizada foi concordante com as recomendações em 98% dos casos (n = 168). Em doentes com CAD-RADS® = 3 (estenose intermédia), os testes funcionais foram requisitados em apenas 36% dos casos (n = 5), enquanto 50% (n = 7) realizaram diretamente angiografia coronária invasiva. Nos doentes em que o estudo não foi diagnóstico, a maioria não realizou nova investigação cardíaca. Conclusão: Nos doentes com classificação CAD-RADS® nos extremos da pontuação, a avaliação cardíaca adicional após realização de AngioTC coronária foi muito semelhante àquela prevista pelo score. Contudo, nos doentes com classificação intermédia, a coronariografia prevaleceu sobre o teste funcional. Keywords: CAD-RADSTM, Coronary artery disease, Coronary computed tomography angiography, Cardiac investigation, Palavras-chave: CAD-RADS®, Doença coronária, AngioTC coronária, Investigação cardíaca

This paper introduces a linear battery aging and degradation model to a multi-energy microgrid sizing model using mixed integer linear programming. The battery aging model and its integration into a larger microgrid sizing formulation are described. A case study is provided to explore the impact of considering battery aging on key results: optimal photovoltaic and storage capacities, optimal distributed energy resources operations strategies, and annual cost and generation metrics. The case study results suggest that considering battery degradation in optimal microgrid sizing problems significantly impacts the perceived value of storage. Depending on capacity loss and lifetime targets, considering battery degradation is shown to decrease optimal storage capacities between 6 and 92% versus scenarios that do not consider battery health. When imposing constant distributed energy resource capacities, inclusion of degradation can decrease optimal annual battery cycling by as much as a factor five and reduce total annual electricity cost savings from otherwise identical photovoltaic and storage systems by 5–12%. These results emphasize that as batteries grow in maturity and ubiquity for distributed energy applications, considering battery health and capacity loss is an essential component of any analytical tool or model to guide system planning and decision-making.

O fracasso escolar é, muitas vezes, atribuído, pela escola, exclusivamente à falta de mérito e dons naturais dos alunos, desvalorizando-se a importância das desigualdades sociais e culturais na análise desta problemática. Assim, o insucesso escolar é tido como incapacidade, por parte do aluno, de atingir os patamares definidos por uma escola assente num código elaborado e com o qual nem todas as crianças e jovens convivem no seio familiar. Traduzido em retenções ao longo do percurso escolar dos alunos, o insucesso escolar obtém contornos de exclusão social para a qual a escola, direta (por via de mecanismos de exclusão interna) e/ou indiretamente (consentindo os processos de exclusão), vai contribuindo. É tendo por base, entre outros, os referenciais das teorias da reprodução social e cultural e os conceitos e mecanismos de exclusão social e escolar, bem como o testemunho de jovens alunos, que, ao longo do seu percurso escolar, foram vivenciando experiências de insucesso e exclusão, que analisamos esses processos (mecanismos de exclusão escolar) num contexto específico (numa escola secundária do litoral centro), refletindo, também, sobre as relações de poder e as desigualdades sociais e escolares. Foi objetivo central desta investigação compreender os mecanismos de exclusão, partindo da problematização do insucesso escolar e refletindo sobre as dinâmicas da escola, bem como analisar e refletir sobre as perspetivas dos participantes (constituídos como co investigadores) face à escola, a fim de perceber como sentem e reagem aos problemas que vivenciam. Este projeto, desenvolvido entre outubro de 2019 e maio de 2020- numa aproximação inicial à metodologia de Investigação-Ação Participativa, pretendia tornar audível, na comunidade escolar, um grupo de 12 alunos de um Curso de Educação e Formação de Serviços de Restauração e Bar, de uma escola secundária da zona litoral centro. Devido ao encerramento das escolas enquanto medida de contenção da propagação do novo coronavírus (SARS-CoV-2), foi necessário ajustar a investigação já em curso, direcionando-a para a Investigação Qualitativa. Os resultados principais prendem-se com a perceção formada da Escola enquanto Instituição falsamente inocente no que concerne à problemática da reprodução das desigualdades de partida no seu interior (percetíveis nesta investigação) e aos mecanismos de exclusão escolar que vão vitimizando, de forma cada vez mais precoce, os alunos oriundos de famílias desfavorecidas e, consequentemente, com percursos marcados pelo insucesso escolar (que se deve, em parte, à distancia da cultura destes alunos da cultura erudita que a escola reproduz mas não traduz). Reconhecemos, que neste estudo em concreto, é possível perceber a influência direta e indireta da escola nos mecanismos de exclusão: Indireta, porque os consente; direta, porque, de forma ativa, vai (des) encaminhando estes alunos para cursos alternativos (como é exemplo os CEF) que desembocam no exterior da escola e que, muitas vezes (como constatamos na investigação), em nada se relacionam com a vontade dos alunos. Terminamos constatando que os participantes (alunos de uma turma de um CEF) se sentem, realmente, excluídos do interior da escola, alegando que ser aluno de um CEF é estar A baixo da base da hierarquia escolar. School failure is often attributed by the school exclusively to students' lack of merit and natural gifts, devaluing the importance of social and cultural inequalities in the analysis of this problem. Thus, school failure is considered as an inability of the student to reach the levels defined by a school based on an elaborated code and with which not all children and young people live within the family. School failure, which is evident in the retentions along the students' school path, obtains characteristics of social exclusion to which the school, directly (through internal exclusion mechanisms) and / or indirectly (allowing the exclusion processes), contributes. It is based on, among others, the theoretical references of the theories of social and cultural reproduction and the concepts and mechanisms of social and school exclusion, as well as the testimony of young students who, throughout their school career, have been undergoing experiences of failure and exclusion, that we analyzed these processes (mechanisms of school exclusion) in a specific context (in a secondary school on the central coast), also reflecting on the power relations and social and school inequalities. The main objective of this investigation was to understand the mechanisms of exclusion, starting from the problematization of school failure and reflecting on the dynamics of the school, as well as to analyze and reflect on the perspectives of the participants (constituted as co-researchers) towards school, in order to understand how they feel and react to the problems they experience. This project, developed between October 2019 and May 2020 - in an initial approach to the Methodology of Participatory Action Research, aimed to make audible, in the school community, a group of 12 students from an Education and Training Course (CEF) for Catering and Bar Services from a secondary school in the central coastal zone. Due to the closure of schools as a measure to contain the spread of the new coronavirus (SARS-CoV-2), it was necessary to adjust the research already underway, directing it to the Qualitative Research. The main results are related not only to the formed perception of the School as a falsely innocent institution in what concerns the problematics of the reproduction of the starting inequalities within school (perceptible in this investigation) but also to the mechanisms of school exclusion that have been victimizing, increasingly earlier, students from disadvantaged families and, consequently, with paths marked by school failure ( which is due, in part, to the distance of these students’ culture from the erudite culture that the school reproduces but does not reflect. We recognize that in this specific study, it is possible to perceive the direct and indirect influence of the school on the exclusion mechanisms: Indirect, because it allows them; direct, because it actively has been (mis) guiding these students to alternative courses (such as the CEF, for example) that ends up outside the school and that often have nothing to do with the students ‘desire (as we could see in the research). We ended up by finding that the participants (students of a CEF class) really do feel excluded from the core of the school life decisions, claiming that being a student of a CEF course means to be below the base of the school hierarchy. Mestrado em Educação e Formação

Dissertação de Mestrado, Educação e Formação (Área de Especialidade em Organização e Gestão da Educação e Formação), Universidade de Lisboa, Instituto de Educação, 2021 Submitted by Biblioteca FPIE-ULisboa (bibliorul@fpie.ulisboa.pt) on 2021-03-31T09:59:02Z No. of bitstreams: 1 ulfpie055871_tm.pdf: 1175040 bytes, checksum: b82fba82e19816e7958da6402aaf8588 (MD5) Made available in DSpace on 2021-03-31T09:59:29Z (GMT). No. of bitstreams: 1 ulfpie055871_tm.pdf: 1175040 bytes, checksum: b82fba82e19816e7958da6402aaf8588 (MD5) Previous issue date: 2021

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease associated with major obstetrical complications such as gestational loss, preterm delivery, fetal growth restriction (FGR) and preeclampsia. Published literature is not consensual regarding the main risk factors for each of these outcomes. Our goal with this study was to determine the most important predictors for each of the main adverse pregnancy outcomes in this population. We conducted a retrospective cohort study of unifetal pregnancies of women with the diagnosis of SLE followed in our unit between January 1994 and December 2016. We excluded elective terminations of pregnancy and cases lost to follow-up and we analyzed 157 pregnancies (128 women). Multiple logistic regression models for the outcomes gestational loss, preterm delivery, fetal growth restriction, and preeclampsia were built. Two-sided p-values of

This chapter presents different methods and tools for microgrid optimal investment and planning problem, focusing on specific methodological aspects addressing the challenges of rural microgrids design. In particular, three aspects of rural microgrids planning are analyzed: (1) the multi-energy nature of rural microgrids, where electricity coexists with other energy vectors (such as heat distribution); (2) the occupation of large portions of the rural territory, which requires planning methods to consider the microgrid internal network constraints; (3) the remote (and sometimes off-the-grid) locations of rural microgrids, which require security criteria and multi-objective approaches to be considered in planning problem. These three methodological aspects are discussed using the example of a real microgrid in Alaska.

Submitted by Ana Rebelo (amsr@isep.ipp.pt) on 2020-11-03T11:59:32Z No. of bitstreams: 1 DM_FranciscoAndrade_2020_MEM.pdf: 5941223 bytes, checksum: b6a2e69f02c000bbcecaf17d868bfdf1 (MD5) Approved for entry into archive by Ana Rebelo (amsr@isep.ipp.pt) on 2020-11-03T12:00:09Z (GMT) No. of bitstreams: 1 DM_FranciscoAndrade_2020_MEM.pdf: 5941223 bytes, checksum: b6a2e69f02c000bbcecaf17d868bfdf1 (MD5) Made available in DSpace on 2020-11-03T12:00:09Z (GMT). No. of bitstreams: 1 DM_FranciscoAndrade_2020_MEM.pdf: 5941223 bytes, checksum: b6a2e69f02c000bbcecaf17d868bfdf1 (MD5) Previous issue date: 2020

The installation and operation distributed energy resources (DER) and the electrification of the heat supply significantly changes the interaction of the residential building stock with the grid infrastructure. Evaluating the mass deployment of DER at the national level would require analyzing millions of individual buildings, entailing significant computational burden. To overcome this, this work proposes a novel bottom-up model that consists of an aggregation algorithm to create a spatially distributed set of typical residential buildings from census data. Each typical building is then optimized with a Mixed-Integer Linear Program to derive its cost optimal technology adoption and operation, determining its changing grid load in future scenarios. The model is validated for Germany, with 200 typical buildings considered to sufficiently represent the diversity of the residential building stock. In a future scenario for 2050, photovoltaic and heat pumps are predicted to be the most economically and ecologically robust supply solutions for the different building types. Nevertheless, their electricity generation and demand temporally do not match, resulting in a doubling of the peak electricity grid load in the rural areas during the winter. The urban areas can compensate this with efficient co-generation units, which are not cost-efficient in the rural areas., Preprint submitted to Energy & Buildings

The acquisition of reading skills is decisive for the academic achievement of students. However, learning to read is a complex process. With this in mind, several attempts have been made to find new educational approaches to enhance students' reading motivation. Considering the enormous potential of ICT for education and training, we have developed a digital repository of teaching and learning materials and a multiplatform application that runs on mobile devices: Letrinhas. This information system was designed to promote the development of reading and to provide tools for monitoring and assessing reading skills against the curricular targets set by the Ministry of Education. Letrinhas was evaluated by specialists and users and a high level of satisfaction was observed among students and teachers as time and effort spent to consolidate reading is considerably reduced with this application. This evaluation also enabled to identify features that will be available in the future.

This paper proposes a new methodology to capture the impact of fast moving clouds on utility power demand charges observed in microgrids with photovoltaic (PV) arrays, generators, and electrochemical energy storage. It consists of a statistical approach to introduce sub-hourly events in the hourly economic accounting process. The methodology is implemented in the Distributed Energy Resources Customer Adoption Model (DER-CAM), a state of the art mixed integer linear model used to optimally size DER in decentralized energy systems. Results suggest that previous iterations of DER-CAM could undersize battery capacities. The improved model depicts more accurately the economic value of PV as well as the synergistic benefits of pairing PV with storage.

Electric retail rate design is relevant to utilities, customers, and regulators as retail rates impact the utility's revenue as well as the customers' electricity bills. In California, regulators approve rate proposals by privately owned vertical integrated utilities. Approval, however, is subject to compliance with multiple, potentially conflicting objectives such as economic or environmental objectives. Additionally, retail rates are price signals that affect how customers use electricity services. When utility customers change their usage, they also impact the ratemaking objectives to which rates have been designed. This suggests a feedback loop, which is particularly pronounced with prosumers, as they can systematically optimize their interactions with the electricity system. Prevalent ratemaking methods may not deliver retail rates that are optimal for multiple objectives when customers are prosumers. We propose a novel ratemaking method that formalizes the problem of designing retail rates as a multi-criteria optimization problem and accounts for prosumer reactions through a simulation-based optimization approach. Through a fictive case study, we found that the resulting Pareto frontiers are useful in recognizing and balancing tradeoffs among conflicting ratemaking objectives. Additionally, our results indicate that prevailing retail rates in California are not Pareto optimal.

Current guidelines recommend the use of the Modified Diamond-Forrester (MDF) method to assess the pre-test likelihood of obstructive coronary artery disease (CAD). We aimed to compare the performance of the MDF method with two contemporary algorithms derived from multicenter trials that additionally incorporate cardiovascular risk factors: the calculator-based 'CAD Consortium 2' method, and the integer-based CONFIRM score.We assessed 1069 consecutive patients without known CAD undergoing coronary CT angiography (CCTA) for stable chest pain. Obstructive CAD was defined as the presence of coronary stenosis ≥50% on 64-slice dual-source CT. The three methods were assessed for calibration, discrimination, net reclassification, and changes in proposed downstream testing based upon calculated pre-test likelihoods.The observed prevalence of obstructive CAD was 13.8% (n=147). Overestimations of the likelihood of obstructive CAD were 140.1%, 9.8%, and 18.8%, respectively, for the MDF, CAD Consortium 2 and CONFIRM methods. The CAD Consortium 2 showed greater discriminative power than the MDF method, with a C-statistic of 0.73 vs. 0.70 (p0.001), while the CONFIRM score did not (C-statistic 0.71, p=0.492). Reclassification of pre-test likelihood using the 'CAD Consortium 2' or CONFIRM scores resulted in a net reclassification improvement of 0.19 and 0.18, respectively, which would change the diagnostic strategy in approximately half of the patients.Newer risk factor-encompassing models allow for a more precise estimation of pre-test probabilities of obstructive CAD than the guideline-recommended MDF method. Adoption of these scores may improve disease prediction and change the diagnostic pathway in a significant proportion of patients.

The large-scale deployment of distributed energy resources will produce reverse power flows, voltage, and congestion problems in the distribution networks. This paper proposes a novel optimization model to support distribution system operators planning future medium voltage distribution networks characterized by high penetration of behind-the-meter distributed energy resources. The optimization model defines the optimal mix, placement, and size of on-load tap charger transformers and energy storage devices with the objectives of mitigating network technical problems and minimizing both investment and operation costs. The proposed optimization model relaxes the non-convex formulation of the optimal power flow to a constrained second-order cone programming model and exactly linearizes the non-linear model of the on-load tap changer transformer via binary expansion scheme and big-M method. These two transformations reduce the computational burden of the optimization allowing it to be applicable to real-scale distribution grids, as demonstrated by the results. The numerical results also show that the joint optimization of energy storage devices and on-load tap changer transformers produces a more affordable and flexible planning strategy than the individual optimization of the technologies.

Author(s): Cardoso, Goncalo; Heleno, Miguel; DeForest, Nicholas | Abstract: The objective of the project is to develop an advanced optimization-based design support tool for AC or DC microgrids in remote locations, where utility grids may not be accessible. The mathematical model and the interface are being developed such that multiple design objectives and criteria/constraints can be easily enabled or disabled, to deliver a flexible tool relevant to a large, diverse user base, and to facilitate future feature developments. The new tool delivered by this project leverages the team’s extensive expertise in the development, testing, deployment, and commercialization of the state-of-the-art Distributed Energy Resources Customer Adoption Model (DER-CAM) – which is the foundation for the new tool. Phase I of the project leverages the microgrid design and decision support tool DER-CAM. Key Phase I developments include the following adaption to the DER-CAM model: a) AC or DC microgrid architectures, b) multiple economic objectives (e.g. single customer vs community vs utility perspective), c) constraints on fuel availability (e.g. total fuel available during outage periods), d) active and reactive power flow constraints for normal and N-1 contingency cases, e) component part load efficiencies (e.g. power electronic devices), and f) interactive data visualization capabilities (e.g. design topology elements). A component library including components’ default technical and economical characteristics was also developed. In Phase II, the project is focused on tool testing and validation, use for real-world microgrid designs, and outreach. Fully developing this tool will have the following impacts: 1) optimal off-grid microgrid designs that replace existing back of the envelope or non-optimal calculations, reducing capital costs and risk of microgrid deployment; 2) removing barriers to microgrid assessments by lowering microgrid soft costs, as the tool is freely usable; 3) reliable and resilient designs that reduce the cost of critical load shedding due to component outages.

In developing countries, mini-grids are seen as an important option to improve electrification rates in rural areas. In order to be successful, mini-grids face issues of operation and sizing of generation capacities. Current studies on the optimal sizing of mini-grids do not include capacity expansion feedbacks regarding the operator's or investor's long-term economic performance on growth in electricity usage, e.g. gap between demand and supply impacting the operator's income. Using a System Dynamics model, this paper compares the impact from two capacity expansion strategies on rural mini-grid operator's long-term economic performance. The two capacity expansion strategies are: a strategy with minimized costs and a strategy where only diesel power is allowed. Research shows that a cost-minimized capacity expansion strategy might not be the most beneficial solution for the operator's long term financial performance. Specifically, the high investment costs prohibit the implementation of the cost-minimized expansion strategy. In addition, the diesel-only expansion strategy suffers from high operational costs, which creates long-term challenges as the share of diesel increase. Therefore, the timeline of the investments and when to implement different strategies is important, creating a benefit for a System Dynamics approach.

International audience; Microgrid operations are challenging due to variability in loads and renewable energy generation. Advanced tools capable of taking uncertainty into account are essential to maximize microgrid benefits when operating microgrid owned DERs. This paper proposes a novel optimization model for day-ahead economic dispatch of flexible resources within a microgrid environment, considering uncertainty of PV and loads.This model is conceived to support the microgrid supervisory control layer, providing a security-constrained day-ahead strategy to operate three types of microgrid flexible resources: PV, electric storage and controllable loads. The work presented in this paper introduces a novelty in microgrid operations by presenting a stochastic version of the day ahead scheduling of microgrid DERs to deal with uncertainties associated with PV, load and temperature while considering microgrid network limits and end-user comfort as optimization constraints. An annual analysis quantifies the benefits of to the microgrid-owner of a stochastic formulation over a deterministic one both in terms of ensuring end-user comfort and decreasing operation costs.

In this study, we investigate the cost-effectiveness of hydrogen storage systems in industrial microgrids. This analysis is enabled by an extension introduced to the Distributed Energy Resources — Customer Adoption Model. We analyze the potential to mitigate costs associated with volumetric time-of-use rates through arbitrage, reduce peak loads, and optimize the use of on-site generation, amongst others. The analysis is supported by a case study using real load data from two manufacturing companies with significant heat loads. We find that hydrogen storage systems can be economically viable per se and can be competitive with other storage systems such as standard electrochemical storage. The use of a fuel cell with combined heat and power production further integrates sectors but does not lead to financial savings.