Introdução: Estimulação transcraniana com corrente contínua (ETCC) é um método não invasivo de estimulação cerebral que modifica o potencial de repouso da membrana neuronal através de uma corrente elétrica de baixa intensidade. Trata-se de uma técnica neuromodulatória aplicável ao contexto terapêutico de disfunções do sistema nervoso implicados na fisiopatologia da dor e transtornos neuropsiquiátricos, com baixo custo, mínimos efeitos adversos e fácil aplicação. A ETCC tem se mostrado eficaz no tratamento de dores crônicas incluindo a fibromialgia (FM) em curto prazo. Seu uso se sustenta na melhor compreensão dos mecanismos fisiopatológicos dessa síndrome, os quais incluem processos de desinibição em nível cortical e infracortical, demonstrado por medidas neurofisiológicas como facilitação e desinibição, assim como redução da potência dos sistemas modulatórios descendentes da dor, além de alterações nas vias nociceptivas periféricas, como as fibras nervosas finas. No entanto, essa alteração isolada não foi previamente associada à disfunção no sistema de modulação descendente da dor (SMDD), observado na FM. As áreas de aplicação da ETCC dependem do objetivo terapêutico. O córtex motor primário (M1) é o alvo mais estudado e com maior contingente de evidências para o tratamento da dor e reabilitação motora, enquanto o córtex pré-frontal dorsolateral esquerdo (DLPFC) tem sido eficaz na depressão e melhora dos componentes psicoafetivos dos pacientes com dor crônica. Seu principal limitador prático é a necessidade de ir ao centro de atendimento durante dias consecutivos, pois o efeito terapêutico sustentado da ETCC necessita repetição das sessões Objetivos: Esta tese está constituída por dois estudos. O primeiro objetiva examinar se a disfunção de fibras finas que ocorre em pacientes com FM está ligada a um mau funcionamento do sistema modulador descendente da dor. No segundo, o objetivo é avaliar a eficácia do uso em longo prazo da ETCC em nível domiciliar na FM, com o objetivo de facilitar o uso e permitir a disponibilização desta técnica a pacientes do Sistema Único de Saúde. Estudo I: No primeiro estudo avaliamos se a disfunção de fibras nervosas finas periféricas está ligada a um mau funcionamento do sistema modulador descendente da dor (SMD) na FM. Métodos: Foi realizado um estudo exploratório no qual 41 mulheres com FM e 28 voluntárias saudáveis foram submetidas a testes psicofísicos que avaliaram a função de fibras sensitivas envolvidas na nocicepção. O teste quantitativo sensorial (QST) foi utilizado para medir o limiar perceptivo térmico (HTT), o limiar de dor térmica (HPT) e o limiar de tolerância à dor térmica (HPTo), bem como avaliar a mudança na Escala Numérica de Dor (NPS0-10) durante uma tarefa de modulação da dor condicionada (CPM-task). A algometria foi utilizada para determinar o limiar de pressão de dor (PPT). Escalas para avaliação de catastrofização, ansiedade, depressão e distúrbios do sono também foram aplicadas. O fator neurotrófico derivado do cérebro (BDNF) foi medido como um marcador de neuroplasticidade. Realizamos modelos de regressão linear multivariada por grupo (saudáveis e FM) para estudar a relação entre a função do SMD e sua relação com as medidas psicofísicas. Resultados: As amostras diferiram em seu perfil psicológico, e nas medidas psicofísicas, o grupo e pacientes com FM apresentou menor sensibilidade e limiares de dor. Na FM, mas não nos saudáveis, os modelos de regressão revelaram que o HTT estava relacionado ao BDNF e ao CPM-Task (Hotelling's Trace = 1,80, P<0,001, poder=0,94, R2=0,64). HTT foi correlacionado positivamente com a CPM-task (B = 0,98, P= 0,004, Partial-ƞ2=0,25), e ao HPT (B=1,61, P=0,008, parcial -ƞ2= 0,21). No entanto PPT não foi correlacionado com o HTT. Na FM a relação do BDNF com CPM-Task teve uma relação negativa (B=-0,04, P=0,043, parcial-ƞ2=0,12) e a HPT foi diretamente proporcional (B= - 0,08, P=0,03, parcial-ƞ2 = 0,14). O BDNF não influenciou no modelo. E os efeitos adversos relatados foram maiores no grupo ativo (17,8%) em comparação com o grupo sham (6,6%). Conclusão: A disfunção sensorial periférica está associada positivamente à disfunção do sistema modulatório descendente da dor e aos níveis séricos de BDNF na FM, o que não ocorre em indivíduos saudáveis. Estudo II: O segundo estudo teve como objetivo avaliar a eficácia do uso domiciliar de 60 sessões da ETCC-ativa e ETCC-simulada aplicadas sobre a área DLPFC esquerda, nas pacientes com diagnóstico de FM. Métodos: Foi realizado um ensaio clínico randomizado, duplo cego, em paralelo, controlado com ETCC-simulada em 20 mulheres com diagnóstico de fibromialgia. A estimulação foi realizada durante cinco dias consecutivos na semana, durante 30 min, com a intensidade de 2 mA, por 12 semanas, totalizando 60 sessões. As pacientes receberam treinamento para uso do equipamento especialmente desenvolvido para uso domiciliar e mantinham contato com o pesquisador responsável por meio de mensagem de texto diariamente. Os efeitos foram medidos por meio da escala visual de dor (EAV) durante o curso de 12 semanas de tratamento, bem como o uso de analgésicos e possíveis eventos adversos, diariamente. Foram avaliados os níveis de depressão, catastrofismo e capacidade funcional para tarefas diárias, QST para verificar limiar de dor e tolerância ao calor, PPT e dosagem dos níveis séricos de BDNF no início, após 30 sessões e no final do tratamento. Um modelo linear misto com efeitos fixos foi usado para comparar mudanças nos escores de dor na EAV ao longo do tratamento. Resultados: A ETCC ativa domiciliar reduziu os escores de dor pela EAV (p<0.001) quando comparado ao sham, com uma redução média de dor de 64% (p<0.001). Além disso, ETCC ativa reduziu significativamente a incapacidade relacionada a dor [B-PCP:S escore total (p=0.023);-ƞ2=0.61]. Também reduziu os escores nas medidas clínicas de depressão, catastrofismo e qualidade do sono [BDI-II, PCS e PSQI (p<0.05)]. No entanto, ETCC ativa aumentou os escores na algometria (PPT) e tolerância térmica (HPTo) (p<0.01). O BDNF não influenciou no modelo. Os efeitos adversos relatados foram maiores no grupo ativo (17,8%) em comparação com o grupo sham (6,6%). Conclusão: A ETCC para uso domiciliar mostrou-se segura e eficaz na redução da dor, incapacidade relacionada a dor, sintomas depressivos e catastróficos e redução do uso de analgésicos. O conjunto de dados desta tese sugere que em pacientes fibromiálgicas, o nível de disfunção do sistema modulador descendente da dor está relacionado ao nível de disfunção de fibras nervosas finas periféricas envolvidas na nocicepção. Além disso, a ETCC de longo prazo em fibromiálgicas foi eficaz na melhora dos sintomas disfuncionais relacionados à dor crônica e se mostrou adequada para uso domiciliar. / Introduction: Transcranial direct current stimulation (tDCS) is a noninvasive method of brain stimulation that modifies the resting potential of the neuronal membrane through a low intensity electrical current. It is a neuromodulatory technique to the therapeutic context of dysfunctions of the nervous system implicit in physiotherapy and neuropsychological disorders, with low cost, adverse effects and easy application. tDCS has been effective without a chronic fight process, including fibromyalgia (FM), in which the processes of disinhibition are cortical and infracortical, demonstrated by neurophysiological as intracortical facilitation and desinhibition, as well as reduction of the power of the systems descending pain modulators. In addition, studies have shown a severity of inhibition of central positive correlation with BDNF (Brain Derived Neurotrophic Factor) levels and seems to have some relation to the peripheral nociceptive pathways, as the areas of application of the stimulation depend on the primary motor cortex (M1) is the most studied target and the largest contingent of selection for the treatment of pain and motor reaction, while the dorsolateral prefrontal cortex (DLPFC) was effective in the treatment of depression and psychoaffective components in cases of patients with the chronic condition. Although tDCS has been successful in treating FM, its main limiter is a need for the service center for consecutive days as it has cumulative effect. In fact, the erasure of the sessions guaranteed the therapeutic effect of the ETCC. The application of measures on consecutive days motivated the study of its value when applied at the household level, in order to allow the large-scale treatment technique to be adopted in the Unified Health System. This is proved by two studies. The first objective is to examine whether a fine-fiber dysfunction that occurs in patients with FM is linked to an operation of the pain-modulating system. Neuropathy of long nerve fibers has been implicated by a descriptor of pain, neurophysiological and psychophysiological neurophysiology, as well as skin biopsy studies. However, this comparison was not associated with dysfunction in the descending pain system (DPMS) not on FM. Objective did the study explore the association of dysfunction of small fibers with the DPMS and other substitutes for nociceptive changes in FM. In the second, the term is a measure of long-term use of ETCC at household level in FM Study I: In this first study evaluating the presence of nerve and peripheral fiber failure, it is linked to the functioning of the descending pain modulator system (DPMS) in FM Methods: It was performed an exploratory study with 41 FM women and 28 healthy volunteers whose were evaluated in psychophysical tests that evaluated a function of sensory fibers involved in nociception. The quantitative sensory test (QST) was used to measure the Heat thermal threshold (HTT), the heat pain threshold (HPT) and the thermal pain tolerance (HPTo), as well as the numerical scale of pain (NPS0 -10 ) over a task of modulation of conditioned pain (CPM-task). Algometry was used to determine the pain pressure threshold (PPT). Scales for evaluation of catastrophic, anxiety, depression and sleep disorders were also applied. Brain-derived neurotrophic factor (BDNF) was measured as a marker of neuroplasticity. Multivariate linear regression models by group (health and FM) for a relationship between a descending modulatory system function and its relationship with psychophysical measures. Results: The samples differed in their psychological profile, and in the psychophysical measures, the group and the patients with FM had lower sensitivity and pain thresholds. At FM, regression models revealed that HTT was related to BDNF and CPM-Task (Hotelling's Trace = 1.80, P <0.001, power = 0.94, R2 = 0.64). HTT was positively correlated with a CPM task (B = 0.98, P = 0.004, partial-ƞ2 = 0.25), and HPT (B = 1.61, P = 0.008, partial -ƞ2 = 0.21) . However PPT was not correlated with HTT. In FM, the relationship of BDNF with CPM, a negative relation was found (B = -0.04, P = 0.043, partial- = 2 = 0.12) and HPT was proportionally (B = -0.08, P = 0.03, partial-ƞ2 = 0.14). BDNF did not influence the model. And the adverse effects reported were higher in the active group (17.8%) compared to the sham group (6.6%). Conclusion: Peripheral sensory dysfunction is positively associated with the modulating dysfunction of BDNF levels in FM, which does not occur in isolated individuals. Study II: The second study had the purpose of evaluating the home use of 60 sessions of atDCS and s-tDCS on a left DLPFC area in patients with FM. Methods: A randomized, double-blind, parallel-sham controlled study in 20 women with FM. Stimulation was performed for five consecutive days in the week for 30 min at the intensity of 2 mA for 12 weeks, totaling 60 sessions. Patients were trained to use equipment specially designed for home use and maintained contact with the researcher responsible through daily text message. The effects were measured through visual pain scale (VAS) daily during the course of 12 weeks of treatment, as well as the use of analgesics and possible adverse events daily. The levels of depression, catastrophism and disability for daily tasks were assessed. The QST was used to check pain threshold and tolerance to heat, an algometry was used to check pressure pain threshold (PPT) and blood collection was performed to evaluate serum BDNF levels at baseline, after 30 sessions and at the end of treatment. A Mixed Linear Model with fixed effects was used to compare changes in pain scores in VAS throughout the treatment. Results: Home-based tDCS reduced dairy pain VAS scores (p<0.001), with cumulative mean pain drop of 64% (p<0.001). Furthermore, active home-based tDCS reduced significantly disability due to pain [B-PCP:S total scores (p=0.023; partial-ƞ2=0.61]. And also reduced scores in clinical measures like depression scores, catastrophizing pain scores and sleep quality scores [BDI-II and PCS (p<0.05), PSQI (p<0.05)]. However, active homebased tDCS enhance scores in algometry (PPT) and heat pain tolerance (HPTo) (p<0.01). Conclusion: Home-based anodal tDCS applied over the DLPFC in FM had a baseline neuroplasticity-dependent reduction effect on pain. In addition, it improved the disability due to pain, depressive symptoms and pain catastrophizing. It reduced the analgesic use and increased pressure and heat pain tolerance.

This doctoral thesis aimed at better understanding the contribution of sleep, Targeted Memory Reactivation and transcranial Direct Current Stimulation (tDCS) on the consolidation of neutral and emotional memories. In the first part of this work, we found that REM-enriched naps and more specifically rapid eye movement density is associated with the consolidation of sad stories, suggesting a possible implication of Ponto-Geniculo-Occipital (PGO) waves in the consolidation of sad information. In addition, we observed an increase in emotional reactivity during re-exposure to the sad story following a REM-enriched nap. We postulate that REM sleep favored the consolidation of the emotionalsalience of the sad memories, leading to exacerbated emotional reactivity during re-exposure. We also investigated the impact of TMR during NREM sleep on the consolidation of neutral and negative word pairs leanred with a specific sound. We found an equal benefit of the TMR procedure on neutral and emotional material, suggesting that emotion does not modulate the selective enhancing effect of TMR during NREM sleep. In an additional study, we tested the impact of verbatim presentation of the pairs of words during NREM sleep and did not find the memory benefits of TMR. We ascribed the absence of TMR memory benefit to the detrimental effect of the auditory presntation of the second word which impaired the memory reactivation processes initiated by the presentation of the first word. Together, theseresults indicate the crucial role of a sensitive plastic time window necessary for the successful processes of memory reactivation during sleep. Finally, we evaluated how the combination of tDCS and TMR procedure during a wakeful rest consolidation interval benefits memory consolidation. We found that TMR alone led to selective memory benefits for cued word pairs. When the TMR procedure was combined with either right-anodal or left anodal tDCS, we observed a significant improved global learning, suggesting that tDCS does not potentiate but overshadows the TMRprocedure. Altogether, these studies offer new perspectives in the field of memory consolidation. More specifically, the application of an alternating current during post-learning sleep concomitantly to a TMR procedure might favor the specific brain oscillations involved in successful memory reactivation, and might enhance the associated memory gains. / Doctorat en Sciences psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished

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My diploma thesis deals with a specific dynamic model of DC motor with the parameters obtained from the calculation and from the program using the finite element method. It shows how much accurate results can be achieved in the model, if you use only the values which can be measured, recorded and calculated on the engine. This thesis contens three parts. First part describes the structure and function of DC motor and the basic principle and the use of FEM. Next is calculation analytical and numerical parameters. The search parameters include torque, resistance and inductance of armature winding, resistance and inductance of excitation windings. The last part is dedicated to creating a dynamic model. Results from the dynamic model and measured values are compared in the conclusion of my thesis.

The thesis describes ways ejection pinions automotive starter and evaluation of the advantages and disadvantages of each solution. The first chapter deals with the principle of operation of DC motors and starters parameters. In the second part, the individual systems are theoretically discussed in terms of design and their advantages and disadvantages. The third part is focused on the most common system, which is analyzed in terms of mechanical and electrical reliability. The last point of the work is to design an experimental analysis Reach starter pinion.

Over the last years, electrical roads have emerged as a cost effective and environmentally friendly solution towards a transportation system with less dependency on fossil fuels. This thesis presents the design of a search and locate system for road-bound conductive electrical roads with position control in two axes. The system is intended to find and follow the position of an electrified rail. The actuator system constitutes a firm groundwork for further research and development in this field. A laboratory test set up has been designed and both hardware and software parts have been constructed. The control of the system uses the CompactRIOTM technology from National Instruments. Results from the practical evaluation suggest that the non-linear characteristic of the system and the lack of direct position feedback from the motor rotation are the main causes of a non-accurate position control. Future development steps should focus on improving the mechanical design and include encoder feedback for the control loop as well as absolute automatic control with the incorporation of rail sensors.

Objectif: Cette thèse vise à étudier si l’inhibition de la douleur par l’activation de la mémoire de travail (MT) peut être rehaussée par la Stimulation Transcranienne à Courant Direct (tDCS) chez des volontaires jeunes et des personnes âgées en bonne santé. La MT permet de sélectionner l’information pertinente à une tâche et de diriger l’attention vers l’exécution de cette tâche, permettant ainsi de limiter la capture de l'attention par des distracteurs, incluant la douleur. Cependant, cette inhibition de la capture attentionnelle par la douleur puisqu’il s’agit d’un processus descendant (top-down), peut être diminuée chez les personnes âgées en raison de la réduction des capacités de la MT. La tDCS est une méthode prometteuse à cet égard puisque la stimulation anodale du cortex préfrontal dorsolatéral (DLPFC) gauche permet d’améliorer les capacités de la MT. Méthodes: Cette thèse comporte deux expériences menées sur quarante jeunes adultes (première étude) et quinze personnes âgées (deuxième étude). Les expériences comportent deux séances de tDCS (tDCS anodale et simulée), pendant lesquelles de la douleur et le réflexe nociceptif de flexion étaient évoqués par une stimulation électrique à la cheville, alors que les participants exécutaient une tâche n-back (0-back et 2-back). Le protocole expérimental comportait cinq conditions dont l'ordre a été contrebalancé (0-back, 2- back, douleur, 0-back avec douleur et 2-back avec douleur), et qui ont été réalisées deux fois chacune (avant tDCS et pendant tDCS). Résultats: Les résultats indiquent que la neuromodulation du DLPFC gauche permet d’améliorer l’inhibition de la douleur par la MT, autant chez les jeunes adultes que chez les personnes âgées. Cependant, le réflexe nociceptif de flexion n’a pas été modulé par l’activation de la MT, suggérant que les effets bénéfiques de la tDCS reposent sur des mécanismes supraspinaux indépendants des voies inhibitrices descendantes. Ces études ont permis l'avancement des connaissances sur les interactions entre la cognition, la douleur et l'âge et montrent comment la neuromodulation peut changer ces interactions pour améliorer l'inhibition de la douleur. Ces résultats permettront le développement de protocoles de neuromodulation pour la gestion de la douleur chez les personnes âgées. / Objective: This thesis aimed to examine whether pain inhibition by working memory (WM) engagement can be enhanced by Transcranial Direct Current Stimulation (tDCS) in young and older healthy volunteers. Directing attention away from painful stimuli is under the control of WM that allows the selection of task-relevant information and directing attention towards task execution. However, top-down inhibition of nociceptive activity and pain may be altered in normal aging due to decreased WM. tDCS is a promising method in this regard since anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) was shown to improve WM performance. Methods: Two experiments were conducted on forty healthy (first study) and fifteen older volunteers (second study). They participated in two tDCS sessions (sham and anodal tDCS), in which the pain was evoked by electrical stimulation at the ankle. Participants performed an n-back task (0-back and 2-back) while they received random electrical stimulation to produce pain and the nociceptive flexion reflex, an index of spinal nociception. The experimental protocol comprised five counterbalanced conditions (0-back, 2-back, pain, 0-back with pain and 2-back with pain) that were performed twice (pre-tDCS baseline and during tDCS). Results: In both studies, neuromodulation of left DLPFC enhanced pain inhibition by WM. However, the nociceptive flexion reflex was not modulated by WM enhancement suggesting that improvement of pain inhibition by WM using tDCS is supraspinal and independent of descending inhibitory pathways. These studies improve our understanding of the interactions between cognition, pain and age and show how neuromodulation may change these interactions to improve pain inhibition. Findings support the development of neuromodulation protocols for pain management in older persons.

To enable fast charging of electric vehicles in Stockholm or sites where the electrical energy is limited and the number of chargeable vehicles increases, there is a need to investigate new solutions to comply with the future demand. The goal of this project is to investigate what the conditions are in Stockholm today and investigate what is needed to enable fast chargers in Stockholm city. Both what electrical equipment is necessary and develop a model to simulate the flow for the available energy and the demanded energy from a charging location. The result shows that battery energy storage systems can help the chargers, but to what degree depends on demand and availability. What is shown is, if the total maximum power demand is greater than the available power from the grid, a battery could be beneficial. In the scenarios, it has been enough to have a 150 kWh battery to increase the total charged energy over the day by more than two times what the grid could supply. / För att möjliggöra snabbladdning av elfordon i Stockholm eller platser där elenergin är begränsad och andelen laddbara fordon ökar måste nya lösningar undersökas för att möta framtidens behov. Målet med detta arbete är att undersöka vad det finns för förutsättningar för laddning i Stockholm i dagsläget och undersöka vad som krävs för att införa snabbladdare i Stockholms stad; vilken elektrisk utrustning som krävs samt ta fram en modell för att simulera ett flöde av tillgänglig energi och efterfråga för en laddplats.  Resultatet av studien är att batterienergilagringsystem kan hjälpa laddarna, men de bidrar olika mycket beroende på efterfrågan och energitillgång direkt från nätet. Om det totala maxeffektbehovet från laddgatan är högre än vad elnätet kan leverera kan det vara lönsamt att ha installerade batterier. I dessa scenarion har det räckt med ett batteri på 150 kWh för att kunna öka den energimängd som laddas över till elfordon under ett dygn med mer än dubbla nätets kapacitet.

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[pt] Existe uma perspectiva crescente da utilização de alta tensão em corrente contínua (ATCC). Assim, com base em informações da literatura sobre ensaios elétricos em equipamentos para ATCC e em exigências quanto à confiabilidade de procedimentos metrológicos, nesta dissertação, propõe-se o monitoramento e análise de um parâmetro (ripple) de forma que se possa garantir a rastreabilidade de sistemas de medição de referência (SMR). Os SMRs permitem apenas uma análise quantitativa da tensão de calibração, sendo preciso avaliar e garantir que a incerteza não seja influenciada por ripples de até 3 por cento, mas torna-se necessário também fazer uma avaliação qualitativa. No caso de ensaios em ATCC, o uso de diferentes fontes e retificadores provoca ripple em diferentes níveis, influenciando na qualidade da tensão fornecida e possivelmente em outros parâmetros relevantes descritos na norma ABNT NBR IEC 60060-1:2013. Nesse contexto, o objetivo desta dissertação foi o aperfeiçoamento e validação, com o rascunho da norma IEC 61083-4, de um algoritmo de medição previamente desenvolvido em LabVIEW que se comunique com um multímetro de 8 (1 sobre 2) dígitos e estime todos os parâmetros normalizados. Estabeleceu-se, ainda, os procedimentos necessários para calibração em ATCC e a análise da influência do ripple a partir dos parâmetros definidos pela norma. Para validar a metodologia proposta nesta dissertação foram feitos ensaios com diferentes arranjos, cuja finalidade foi comparar, estatisticamente, as incertezas de medição da calibração com diferentes níveis de ripple no SMR. Finalmente, os resultados obtidos indicam que o ripple não influencia na calibração. / [en] There is a growing prospect of using high voltage in direct current (HVDC). Thus, based on information from the literature on dielectric tests in equipment for HVDC and requirements regarding the reliability of metrological procedures, this dissertation aims at monitoring and analyzing a specific parameter (ripple) in a way that can guarantee the traceability of reference systems. The reference systems allow only a quantitative analysis of the calibration voltage, being necessary to evaluate and ensure that the measurement uncertainty is not influenced by ripples of up to 3 percent, but it is also necessary to make a qualitative assessment. In the case of HVDC tests, the use of different power supplies and rectifiers causes ripple at different levels, influencing the quality of the supplied voltage and possibly other relevant parameters for the ABNT NBR IEC 60060-1:2013 standard. In this context, the objective of this dissertation was the improvement and validation, with the draft of the IEC 61083-4 standard, of a signal acquisition and processing algorithm developed in LabVIEW that communicates with an 8 (1 over 2) digit multimeter and estimates all the normalized parameters. It is also intended to establish the procedures introduced for HVDC calibration and an analysis of the ripple influence from the parameters defined by the standard. To validate the methodology proposed in this dissertation, tests were made with different arrangements, with universal and purely resistive dividers, and different ripple levels, in the laboratory, statistically comparing the calibration measurement uncertainties with different ripple levels in the traceability of reference systems. Finally, the results indicate that the ripple does not influence the calibration.