Análise e Previsão de Anomalias de Consumo

Trabalho de projeto de mestrado, Matemática Aplicada à Economia e Gestão, Universidade de Lisboa, Faculdade de Ciências, 2018Atualmente a energia elétrica é considerada um bem com uma fundamental aplicação no quotidiano, pois é utilizado para variados fins e sem a eletricidade o ser humano sente-se condicionado. A dependência dos consumidores face à energia elétrica leva a que esta tenha de ser alvo de estudos cada vez mais aprofundados, para que a utilização deste bem não seja ultrapassada pelos avanços tecnológicos da era em que vivemos e, portanto, os consumidores cada vez melhor informados e mais exigentes, não vejam a utilização da energia elétrica como algo limitado. No presente projeto é efetuada uma contextualização ao tema da energia elétrica, com principal foco no consumo de eletricidade por parte de clientes cujas instalações possuem determinadas características. É também abordado o tema da qualidade dos dados em estudo, para que se consiga determinar quando esses dados são considerados anómalos ou, por outras palavras, não tipificados. Este estudo é feito com base na análise de clusters, utilizando dados de consumo históricos, em que as instalações são agregadas em grupos homogéneos. Aplicam-se dois métodos, o de Ward e o de k-means, para se observar a distribuição dos objetos pelos vários grupos. O intuito da análise de clusters é criar grupos com consumos padrão, bem como grupos com consumos considerados suspeitos, para uma imediata comparação entre si. Para complementar a análise de clusters são criados intervalos de 95% de confiança para o valor médio dos consumos padrão, com vista a observar se os grupos suspeitos apresentam consumos considerados estatisticamente tipificados, ou seja, até que ponto as instalações com consumo suspeito podem afinal enquadrar-se nos grupos de referência. Por fim, para compreender qual dos métodos utilizados na análise de clusters é mais eficiente e robusto em termos da identificação de objetos com consumo efetivamente anómalo, é efetuada a comparação entre os resultados obtidos por ambos e outras fontes de informação acerca dos dados.Nowadays the electric energy is fundamental to daily life as it is the basis for many usages in such a way that a power shortage causes tremendous impact. As the consumers become more active players in the energy market, more well informed and more demanding, it is of utmost importance to deeply study this market behavior, so that electric energy services keep up to date with technological advances in all human areas. This project presents a brief background to the electric energy theme, focusing on electric usage by costumers with some specific characteristics, with the aim of studying and understanding when abnormal data are present, in other words, identifying non-typified data. Using historical consumption data, the proposed method to identify abnormal data starts by dividing the observations into homogeneous groups with the help of two different methods: Ward and k-means. This allows to observe the similarity between the variables classified in the same groups as well as the differences among these groups. The goal of the cluster analysis is precisely to group similar consumption locations, targeting reference (standard) patterns, as well as grouping objects with non-typified consumption for an immediate comparison. After dividing the observations into groups, 95% confidence intervals for the means of the standard consumption are built to supplement the cluster analysis and to confirm the non-typified consumption objects grouped before. Finally, both methods, Ward and k-means, are compared looking at the grouping of objects with non-typified consumption in an attempt to conclude which method is better

Anti-staphylococcal activity and mode of action of thioridazine photoproducts

Antibiotic resistance became an increasing risk for population health threatening our ability to fight infectious diseases. The objective of this study was to evaluate the activity of laser irradiated thioridazine (TZ) against clinically-relevant bacteria in view to fight antibiotic resistance. TZ in ultrapure water solutions was irradiated (1–240 min) with 266 nm pulsed laser radiation. Irradiated solutions were characterized by UV–Vis and FTIR absorption spectroscopy, thin layer chromatography, laser-induced fluorescence, and dynamic surface tension measurements. Molecular docking studies were made to evaluate the molecular mechanisms of photoproducts action against Staphylococcus aureus and MRSA. More general, solutions were evaluated for their antimicrobial and efflux inhibitory activity against a panel of bacteria of clinical relevance. We observed an enhanced antimicrobial activity of TZ photoproducts against Gram-positive bacteria. This was higher than ciprofloxacin effects for methicillin- and ciprofloxacin-resistant Staphylococcus aureus. Molecular docking showed the Penicillin-binding proteins PBP3 and PBP2a inhibition by sulforidazine as a possible mechanism of action against Staphylococcus aureus and MRSA strains, respectively. Irradiated TZ reveals possible advantages in the treatment of infectious diseases produced by antibiotic-resistant Gram-positive bacteria. TZ repurposing and its photoproducts, obtained by laser irradiation, show accelerated and low-costs of development if compared to chemical synthesis.publishersversionpublishe

The place of CEUS in distinguishing benign from malignant cervical lymph nodes: a prospective study

Abstract Aims: The aim of the study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) compared to grayscale B-mode and color Doppler ultrasound in differentiate benign versus malign superficial cervical lymph nodes. Material and methods: In a prospective study ultrasonography (gray scale, color and spectral Dopller, and CEUS) was performed in 61 patients (33 men, 28 women; mean age of 51.2 years, range: 18-81 years), with cervical lymphadenopathy. The nodes were examined and biopsied or surgically removed. CEUS was performed with 2.4 ml intravenous bolus of contrast agent Sono Vue and the results were registered with a special software. Results: Of all the nodes, 32 were benign and 29 were malignant (metastases). Solbiati index was higher in benign nodes (2.23 ± 0.84 vs 1.50 ± 0.48, p<0.05). Doppler parameters (vessel location, vascular pattern, pedicullum number, resistivity index, and pulsatility index) were significantly lower in benign nodes (p<0.001), and ROC analysis returned excellent results. For CEUS, derived peak intensity (DPI %) was higher in benign nodes (17.72 ± 5.43 vs 11.76 ± 4.88, p<0.05); regional blood volume (RBV) was also higher (849.8 ± 467.1 vs 458.3 ± 283.3, p<0.05). The time to peak (TTP, s) and area under the curve (AUC, cm2) were similar in both benign and malignant nodes. Enhancement pattern was the most accurate to characterize benign versus malignant nodes. Sensitivity and specificity were higher for DPI, RBV and enhancement pattern from CEUS, according to ROC analysis, compared to gray scale ultrasound, but lower than color Doppler. Analyzing the place of CEUS in lymph node evaluation we found that CEUS is most useful for the evaluation of the lymph nodes with uncertain aspect at gray scale and Doppler evaluation. Conclusions: ROC analysis confirmed the higher degree of diagnostic accuracy of CEUS in comparison with conventional techniques for some parameters such as enhancement pattern. Evaluation of nodal perfusion with this method can be helpful in the differentiation of benign from malignant nodes but requires further confirmation

The place of CEUS in distinguishing benign from malignant cervical lymph nodes: a prospective study

Abstract Aims: The aim of the study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) compared to grayscale B-mode and color Doppler ultrasound in differentiate benign versus malign superficial cervical lymph nodes. Material and methods: In a prospective study ultrasonography (gray scale, color and spectral Dopller, and CEUS) was performed in 61 patients (33 men, 28 women; mean age of 51.2 years, range: 18-81 years), with cervical lymphadenopathy. The nodes were examined and biopsied or surgically removed. CEUS was performed with 2.4 ml intravenous bolus of contrast agent Sono Vue and the results were registered with a special software. Results: Of all the nodes, 32 were benign and 29 were malignant (metastases). Solbiati index was higher in benign nodes (2.23 ± 0.84 vs 1.50 ± 0.48, p<0.05). Doppler parameters (vessel location, vascular pattern, pedicullum number, resistivity index, and pulsatility index) were significantly lower in benign nodes (p<0.001), and ROC analysis returned excellent results. For CEUS, derived peak intensity (DPI %) was higher in benign nodes (17.72 ± 5.43 vs 11.76 ± 4.88, p<0.05); regional blood volume (RBV) was also higher (849.8 ± 467.1 vs 458.3 ± 283.3, p<0.05). The time to peak (TTP, s) and area under the curve (AUC, cm2) were similar in both benign and malignant nodes. Enhancement pattern was the most accurate to characterize benign versus malignant nodes. Sensitivity and specificity were higher for DPI, RBV and enhancement pattern from CEUS, according to ROC analysis, compared to gray scale ultrasound, but lower than color Doppler. Analyzing the place of CEUS in lymph node evaluation we found that CEUS is most useful for the evaluation of the lymph nodes with uncertain aspect at gray scale and Doppler evaluation. Conclusions: ROC analysis confirmed the higher degree of diagnostic accuracy of CEUS in comparison with conventional techniques for some parameters such as enhancement pattern. Evaluation of nodal perfusion with this method can be helpful in the differentiation of benign from malignant nodes but requires further confirmation

TULBURAREA METABOLICĂ SEVERĂ – CAUZĂ DE DECES LA UN SUGAR AVÂND O BOALĂ CRONICĂ

Hiperplazia congenitală suprarenală reprezintă o tulburare în sinteza steroizilor, cu transmitere autozomal recesivă şi cu prevalenţă mare în cazul copiilor proveniţi din relaţii de consangvinitate. Prezentăm cazul unui sugar de sex masculin, diagnosticat la vârsta de 2 luni cu sindrom de pierdere de sare şi hiperplazie congenitală suprarenală forma clasică fără semne de virilizare, alături de un review al datelor din literatura recentă legată de acest subiect. Diagnosticul a fost pus pe baza istoricului familial, a datelor clinice şi paraclinice. Prognosticul poate fi unul favorabil atât timp cât există complianţă la tratamentul de substituţie cu glucocorticoizi. Totodată, riscul de deces este ridicat prin crizele suprarenale şi dezechilibrul metabolic major

Synthesis of Magnetic Nanoparticles and nanoparticles and Strategies towards Magneto-Photonic Materials

El proyecto propuso obtener un sistema óptico que responda a estímulos externos, en concreto, a campos magnéticos. Cristales fotónicos de dos y tres dimensiones fueron seleccionados como sistemas ópticos para ser funcionalizados con nanopartículas magnéticas para obtener cristales magneto-fotónicos (MPCs). La funcionalización de cristales fotónicos tuvo como objeto no solamente permitir los cambios en la posición espectral del bandgap utilizando un campo magnético externo, sino también permitir respuestas magneto-ópticas aumentadas a determinadas longitudes de onda debido a la interacción luz-materia. Previamente se ha demostrado que la respuesta magneto-óptica en un cristal fotònico 1D aumenta significativamente para frecuencias en el borde del bandgap. Sin embargo, lograr cristales 3D de alta calidad es mucho más complejo y, por lo tanto, conseguir una respuesta magneto-óptica óptima, comparable a la de los cristales magneto-fotónicos 1D, sigue siendo un tema difícil. Los cristales magneto-fotónicos tridimensionales con una respuesta magneto-óptica aumentada pueden ser una plataforma adecuada para el desarrollo, por ejemplo, de una nueva generación de aislantes ópticos rápidos y compactos para transmisión en comunicaciones ópticas, disminuyendo drásticamente su espesor y en consecuencia las pérdidas ópticas (la cual es ventajoso para la óptica integrada). Los objetivos de esta tesis doctoral han sido : 1) sintetizar nanopartículas magnéticas de alta cristalinidad (níquel, óxido de hierro y ferrita de manganeso) a través de métodos químicos, con el fin de controlar el tamaño de las nanopartículas a través de diversos parámetros experimentales y para estudiar la estabilidad de las soluciones coloidales magnéticas, 2) la fabricación de materiales magneto-fotònicos mediante: i) técnicas ¨bottom-up´´-para la incorporación de nanopartículas magnéticas en un cristal fotónico prefabricado (2D o 3D) y ii) métodos ¨top-down¨ -p.e., mediante técnicas litográficas (haz de electrones y litografía nanoimprint), 3) la caracterización estructural y morfológica de los materiales fotónicos preparados, 4) optimizar la fabricación de los cristales magneto-fotónicos para garantizar una respuesta magneto-óptica aumentada a longitudes de onda cerca del bandgap óptico. La presente tesis está dividida en seis capítulos El capítulo 1 incluye una introducción general a las nanopartículas magnéticas, los materiales cristales fotónicos convencionales y funcionalizados (magneto-fotónicos). Las nanopartículas magnéticas de tipo metálico (níquel) y de óxido metálico (óxido de hierro y manganeso de ferrita) se describen a través de sus propiedades, la síntesis, estabilidad de las soluciones coloidales y sus aplicaciones. Se presentan los materiales fotònicos y magneto-fotònicos con sus características estructurales y óptica y magneto-óptica. El capítulo 2 describe la síntesis química de nanopartículas magnéticas por tres vías diferentes: la descomposición térmica, calentamiento por microondas y la síntesis continua en etanol supercrítico. El control del tamaño de las nanopartícula y la estabilidad de las soluciones coloidales magnéticas son analizadas. También se aborda la caracterización estructural, morfológica y funcional de las nanopartículas preparadas. El capítulo 3 está enfocado a la fabricación de los cristales magneto-fotònicos bidimensionales por técnicas de ´´top-down´´ (haz de electrones y la litografía por nanoimprint) y bottom-up (depósito de partículas magnéticas asistida por microondas). Para ambas estrategias se describe el protocolo de fabricación desarrollado, junto con la caracterización estructural, morfológica y funcional de los materiales fabricados. El capítulo 4 describe la fabricación de los materiales magneto-fotónicos tridimensionales mediante técnicas bottom-up basadas en dos estrategias, utilizando: i) nanopartículas sintetizadas ex-situ (método de dip-coating asistido por motor paso a paso) y ii) nanopartículas sintetizadas in-situ (depósito asistido por microondas). En el capítulo 5 se enumeran las principales conclusiones de la tesis y se hacen sugerencias para trabajos futuros. El capítulo 6 incluye los anexos. El anexo i. presenta la lista de las publicaciones relacionadas con esta tesis. El anexo ii. incluye una breve descripción de las técnicas experimentales utilizadas y protocolos aplicados para la preparación de las muestras. Los anexos III. y IV contienen las tablas detalladas con las condiciones experimentales y los datos de fabricación de nanopartículas magnéticas y ópalos magnéticos, respectivamente.The project aimed to obtain an optical system responding to an external stimulus (magnetic field). Photonic crystal materials (two and three dimensions) were selected as the optical systems to be further functionalized with magnetic nanoparticles, to obtain magneto-photonic crystals (MPCs). This functionalization not only would enable the tunability of photonic band gap spectral position using an external magnetic field, but also would enable an enhanced magneto-optical response near photonic band-edge frequencies due to light-matter interaction. It has previously been demonstrated that the magneto-optical response of one-dimensional (1D) MPCs is significantly enhanced at band-edge frequencies. The achievement of high-quality 3D-MPCs is much more complex and the attainment of an optimal magneto-optical response, comparable to that of 1D-MPCs, remains a challenging issue and the work of this thesis goes in this direction. Three dimensional magnetophotonic crystals with enhanced magneto-optical response can be a suitable platform for the development, for instance, of a new generation of fast and compact optical isolators for optical transmission, drastically reducing their thickness and optical losses (advantageous for integrated optics). The objectives of this PhD thesis have been: 1 ) to synthesize highly crystalline magnetic nanoparticles (nickel, iron oxide and manganese ferrite) via a chemical method, to tune the nanoparticles size by playing with various experimental parameters and to study the stability of the obtained liquid magnetic colloids; 2 ) to fabricate magnetophotonic materials by: i) bottom-up techniques – incorporating magnetic nanoparticles into a prefabricated photonic crystal (2D or 3D) and ii) top-down method – nanopatterning of magnetic composite material by lithographic techniques (electron beam and nanoimprint lithography); 3 ) to characterize the prepared photonic materials structurally and morphologically ; 4 ) and to optimize magneto-photonic materials fabrication to ensure appropriate magneto-optical response , namely enhanced magento-optical response near photonic band-edge frequencies. The PhD thesis report is divided into six chapters: Chapter 1 provides a general introduction to magnetic nanoparticles, conventional photonic crystal materials and functionalized magnetophotonic crystals. Magnetic nanoparticles such as metallic (nickel) and metal oxide (iron oxide and manganese ferrite) nanoparticles are discussed through their properties, synthesis, stabilization and applications. Photonic and magnetophotonic materials with their structural and optical/magneto-optical characteristics are presented. Chapter 2 describes the chemical synthesis of magnetic nanoparticles by three different pathways: thermal decomposition, microwave heating and continuous supercritical ethanol synthesis. The tunability of the nanoparticles size and stability of the magnetic colloids are studied. Structural, morphological and functional characterizations of the prepared nanoparticles are discussed. Chapter 3 deals with the fabrication of two-dimensional magneto-photonic materials by top-down (electron beam and nanoimprint lithography) and bottom-up (microwave-assisted deposition) approaches. For both strategies, an individual fabrication protocol was developed. Structural, morphological and functional characterizations of the fabricated materials are discussed. Chapter 4 describes the fabrication of three-dimensional magneto-photonic materials by bottom-up approaches using both ex-situ synthesized nanoparticles (vertical dip-casting deposition) and in-situ synthesized nanoparticles (microwave-assisted coating). Characterization and optimization of these materials are furthermore presented. Chapter 5 lists the main conclusions of the thesis and makes suggestions for future works. Chapter 6 includes the annexes. Annex i. lists the publication I have co-authored related to this thesis. Annex ii. includes a brief description of the experimental techniques used and protocols applied for samples preparation. Annex iii. and iv contains tables with detailed experimental conditions and measurements for magnetic nanoparticles and magnetic opals, respectively