Funções Executivas (Frontal Assessment Battery), Capacidade Visuo Construtiva e Memória (Rey Complex Figure) numa Amostra de Idosos sob Resposta Social

Introdução: As funções executivas (FE) têm sido sistematicamente associadas ao funcionamento dos lobos frontais e sabemos que o declínio cognitivo se associa a piores resultados em provas que avaliam estas funções. Para além de pretendermos analisar se um teste que avalia as FE (Frontal Assessment Battery/FAB) discrimina idosos com/sem declínio cognitivo, avaliado através do Montreal Cognitive Assessment (MoCA) e se existem associações entre os resultados obtidos com a Figura Complexa de Rey-Osterreith/FCR-O (qualidade da cópia, memória de 3 e de 20 minutos) e a presença/ausência de declínio cognitivo, queremos sobretudo analisar se a qualidade e exactidão da cópia (capacidade visuo construtiva) e a memória de 3 minutos na FCR-O se associam ao resultado obtido com a FAB, dado que as duas provas estão supostamente associadas às FE e ao funcionamento dos lobos frontais avaliados com o FAB, por oposição à memória de 20 minutos (supostamente associada à área temporal, não avaliada pela FAB). Não deixámos de considerar, ainda, a associação entre as variáveis sociodemográficas e os resultados na FAB, na FCR-O e no MoCA. Metodologia: A amostra total incluiu 556 idosos (média de idades, M = 80,2; Desvio-padrão, DP = 5,23; variação = 60-100) sob resposta social em diferentes instituições do Concelho de Coimbra que aceitou responder voluntariamente (ou cujos familiares/cuidadores concederam consentimento) a uma bateria de testes (incluindo questões sociodemográficas, a FCR-O, o MoCA e a FAB). Estas variáveis foram estratificadas de acordo com a idade e escolaridade dos idosos e dicotomizadas. Para testar os nossos objetivos recorremos a diferentes sub amostras compostas pelos sujeitos que tinham resultados nas provas cujas associações queríamos testar. Resultados: De acordo com o MoCA, 59,7% dos idosos apresentavam declínio cognitivo, com 73,9% a apresentar défice executivo ligeiro, de acordo com a FAB. Quanto à FCR-O, 24,0% dos idosos apresentavam défice práxico ligeiro a moderado, 73,9% défice mnésico visual a curto prazo leve (3 minutos) e 60.9% défice mnésico visual a longo prazo leve a moderado (20 minutos). Não se verificaram associações estatisticamente significativas entre o género, estado civil e tipo de resposta social e as três variáveis centrais do estudo (MoCA, FAB e FCR-O). Quer a FAB, quer a FCR-O (as três provas: qualidade e exatidão da cópia, memória de 3 e 20 minutos) revelaram associações com a ausência/presença de declínio cognitivo. Considerando as variáveis estratificadas pela idade e escolaridade dos idosos e dicotomizadas, um teste do qui quadrado para a independência mostrou que a prova qualidade da FCR-O não estava associada ao resultado na FAB (com/sem défice executivo), ao contrário da prova memória de 3 minutos da FCR-O, que se mostrou associada a este resultado. A prova memória de 20 minutos da FCR-O voltou a não estar associada à ausência/presença de défice executivo (usando o mesmo teste). Analisando as diferentes provas da FCR-O e a FAB, sem estratificação, correlações de Spearman confirmaram as associações encontradas, mas também entre a prova qualidade da cópia da FCR-O e a FAB. Conclusão/Discussão: Os resultados seguem a literatura quanto à associação entre a prova da FCR-O memória a curto prazo/3 minutos e as funções executivas (associadas aos lobos frontais e testadas através da FAB), por oposição com a memória a longo prazo que aparece, na literatura, como mais associada/ou envolvendo à/a área temporal e que, de facto, não se mostrou associada ao resultado na FAB. Os resultados não são tão claros/consensuais no que toca à prova qualidade da cópia da FCR-O.

Application of battery energy storage in the Québec interconnection

Le Système Stockage de l’Énergie par Batterie ou Batterie de Stockage d’Énergie (BSE) offre de formidables atouts dans les domaines de la production, du transport, de la distribution et de la consommation d’énergie électrique. Cette technologie est notamment considérée par plusieurs opérateurs à travers le monde entier, comme un nouveau dispositif permettant d’injecter d’importantes quantités d’énergie renouvelable d’une part et d’autre part, en tant que composante essentielle aux grands réseaux électriques. De plus, d’énormes avantages peuvent être associés au déploiement de la technologie du BSE aussi bien dans les réseaux intelligents que pour la réduction de l’émission des gaz à effet de serre, la réduction des pertes marginales, l’alimentation de certains consommateurs en source d’énergie d’urgence, l’amélioration de la gestion de l’énergie, et l’accroissement de l’efficacité énergétique dans les réseaux. Cette présente thèse comprend trois étapes à savoir : l’Étape 1 - est relative à l’utilisation de la BSE en guise de réduction des pertes électriques ; l’Étape 2 - utilise la BSE comme élément de réserve tournante en vue de l’atténuation de la vulnérabilité du réseau ; et l’Étape 3 - introduit une nouvelle méthode d’amélioration des oscillations de fréquence par modulation de la puissance réactive, et l’utilisation de la BSE pour satisfaire la réserve primaire de fréquence. La première Étape, relative à l’utilisation de la BSE en vue de la réduction des pertes, est elle-même subdivisée en deux sous-étapes dont la première est consacrée à l’allocation optimale et le seconde, à l’utilisation optimale. Dans la première sous-étape, l’Algorithme génétique NSGA-II (Non-dominated Sorting Genetic Algorithm II) a été programmé dans CASIR, le Super-Ordinateur de l’IREQ, en tant qu’algorithme évolutionniste multiobjectifs, permettant d’extraire un ensemble de solutions pour un dimensionnement optimal et un emplacement adéquat des multiple unités de BSE, tout en minimisant les pertes de puissance, et en considérant en même temps la capacité totale des puissances des unités de BSE installées comme des fonctions objectives. La première sous-étape donne une réponse satisfaisante à l’allocation et résout aussi la question de la programmation/scheduling dans l’interconnexion du Québec. Dans le but de réaliser l’objectif de la seconde sous-étape, un certain nombre de solutions ont été retenues et développées/implantées durant un intervalle de temps d’une année, tout en tenant compte des paramètres (heure, capacité, rendement/efficacité, facteur de puissance) associés aux cycles de charge et de décharge de la BSE, alors que la réduction des pertes marginales et l’efficacité énergétique constituent les principaux objectifs. Quant à la seconde Étape, un nouvel indice de vulnérabilité a été introduit, formalisé et étudié ; indice qui est bien adapté aux réseaux modernes équipés de BES. L’algorithme génétique NSGA-II est de nouveau exécuté (ré-exécuté) alors que la minimisation de l’indice de vulnérabilité proposé et l’efficacité énergétique représentent les principaux objectifs. Les résultats obtenus prouvent que l’utilisation de la BSE peut, dans certains cas, éviter des pannes majeures du réseau. La troisième Étape expose un nouveau concept d’ajout d’une inertie virtuelle aux réseaux électriques, par le procédé de modulation de la puissance réactive. Il a ensuite été présenté l’utilisation de la BSE en guise de réserve primaire de fréquence. Un modèle générique de BSE, associé à l’interconnexion du Québec, a enfin été proposé dans un environnement MATLAB. Les résultats de simulations confirment la possibilité de l’utilisation des puissances active et réactive du système de la BSE en vue de la régulation de fréquence.

Coupled diusion and mechanics in battery electrodes

Thesis (Ph.D.)--University of Washington, 2016-08

The effect of dissolved magnesium on diffusion creep in calcite

We experimentally tested a series of synthetic calcite marbles with varying amounts of dissolved magnesium in a standard triaxial deformation machine at 300 MPa confining pressure, temperatures between 700 and 850°C, stresses between 2 and 100 MPa, and strain rates between 10−7 and 10−3 s−1. The samples were fabricated by hot isostatic pressing of a mixture of calcite and dolomite at 850°C and 300 MPa. The fabrication protocol resulted in a homogeneous, fine-grained high-magnesian calcite aggregate with minimal porosity and with magnesium contents between 0.07 and 0.17 mol% MgCO3. At stresses below 40 MPa the samples deformed with linear viscosity that depended inversely on grain size to the 3.26±0.51 power, suggesting that the mechanisms of deformation were some combination of grain boundary diffusion and grain boundary sliding. Because small grain sizes tended to occur in the high-magnesium calcite, the strength also appeared to vary inversely with magnesium content. However, the strength at constant grain size does not depend on the amount of dissolved magnesium, and thus, the impurity effect seems to be indirect. At stresses higher than 40 MPa, the aggregates become non-linearly viscous, a regime we interpret to be dislocation creep. The transition between the two regimes depends on grain size, as expected. The activation energy for diffusion creep is 200±30 kJ/mol and is quite similar to previous measurements in natural and synthetic marbles deformed at similar conditions with no added magnesium.

Influence of Cobalt on the Properties of Load-Sensitive Magnesium Alloys

In this study, magnesium is alloyed with varying amounts of the ferromagnetic alloying element cobalt in order to obtain lightweight load-sensitive materials with sensory properties which allow an online-monitoring of mechanical forces applied to components made from Mg-Co alloys. An optimized casting process with the use of extruded Mg-Co powder rods is utilized which enables the production of magnetic magnesium alloys with a reproducible Co concentration. The efficiency of the casting process is confirmed by SEM analyses. Microstructures and Co-rich precipitations of various Mg-Co alloys are investigated by means of EDS and XRD analyses. The Mg-Co alloys' mechanical strengths are determined by tensile tests. Magnetic properties of the Mg-Co sensor alloys depending on the cobalt content and the acting mechanical load are measured utilizing the harmonic analysis of eddy-current signals. Within the scope of this work, the influence of the element cobalt on magnesium is investigated in detail and an optimal cobalt concentration is defined based on the performed examinations.

BATTERY POWERED PORTABLE VAPOR COMPRESSION CYCLE SYSTEM WITH PCM CONDENSER

A battery powered air-conditioning device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The main focus of the current research was on the development of the cooling system. The cooling capacity of the vapor compression cycle measured was 165.6 W with system COP at 2.85. It was able to provide 2 hours cooling without discharging heat to the ambient. The PCM was recharged in nearly 8 hours under thermosiphon mode.

Maize inbreds from different heterotic groups as favorable sources for increased potential bioavailability of magnesium, iron, manganese and zinc

Malnutrition, as a global problem, is mainly caused by low level of mineral elements in staple food (deficient soil). Biofortification is based on selection of genotypes with enhanced concentration of mineral elements in grain, as well as decreased concentration of substances which interfere bioavailability of mineral elements in gut (like phytic acid), and increased content of substances that increase availability (such as β-carotene). The experiment with 51 maize ( Zea mays L.) inbred lines with different heterotic background was set up in order to evaluate chemical composition of grain and to determine the relations between phytic acid (PA), β-carotene, and mineral elements: Mg, Fe, Mn, and Zn. The highest average phytate, β-carotene, Fe, and Mn content was found in grain of inbreds from Lancaster heterotic group. The highest content of Mg was in grain of Independent source and Zn in grain of BSSS group. Increased level of Fe and Mn in Lancaster lines could be partially affected by higher PA content in grain, while increased β-carotene content could improve Mn and Zn availability from grain of BSSS genotypes and Mg availability from Lancaster inbreds. It is important to underline that PA reduction is followed by Zn content increase in grain of Lancaster heterotic group, as well as that variations in Mg, Fe, and Mn contents are independent on PA status in inbreds from Independent source, indicating that the genotypes with higher Mg, Fe and Mn status from this group could serve as favorable source for improved Mg, Fe, and Mn absorption.

Cyber foraging for green computing, improving performance and prolonging battery life of mobile devices

The increasing dependency of everyday life on mobile devices also increases the number and complexity of computing tasks to be supported by these devices. However, the inherent requirement of mobility restricts them from being resources rich both in terms of energy (battery capacity) and other computing resources such as processing capacity, memory and other resources. This thesis looks into cyber foraging technique of offloading computing tasks. Various experiments on android mobile devices are carried out to evaluate offloading benefits in terms of sustainability advantage, prolonging battery life and augmenting the performance of mobile devices. This thesis considers two scenarios of cyber foraging namely opportunistic offloading and competitive offloading. These results show that the offloading scenarios are important for both green computing and resource augmentation of mobile devices. A significant advantage in battery life gain and performance enhancement is obtained. Moreover, cyber foraging is proved to be efficient in minimizing energy consumption per computing tasks. The work is based on scavenger cyber foraging system. In addition, the work can be used as a basis for studying cyber foraging and other similar approaches such as mobile cloud/edge computing for internet of things devices and improving the user experiences of applications by minimizing latencies through the use of potential nearby surrogates.

Energy Management of a Battery-Ultracapacitor Hybrid Energy Storage System in Electric Vehicles

Electric vehicle (EV) batteries tend to have accelerated degradation due to high peak power and harsh charging/discharging cycles during acceleration and deceleration periods, particularly in urban driving conditions. An oversized energy storage system (ESS) can meet the high power demands; however, it suffers from increased size, volume and cost. In order to reduce the overall ESS size and extend battery cycle life, a battery-ultracapacitor (UC) hybrid energy storage system (HESS) has been considered as an alternative solution. In this work, we investigate the optimized configuration, design, and energy management of a battery-UC HESS. One of the major challenges in a HESS is to design an energy management controller for real-time implementation that can yield good power split performance. We present the methodologies and solutions to this problem in a battery-UC HESS with a DC-DC converter interfacing with the UC and the battery. In particular, a multi-objective optimization problem is formulated to optimize the power split in order to prolong the battery lifetime and to reduce the HESS power losses. This optimization problem is numerically solved for standard drive cycle datasets using Dynamic Programming (DP). Trained using the DP optimal results, an effective real-time implementation of the optimal power split is realized based on Neural Network (NN). This proposed online energy management controller is applied to a midsize EV model with a 360V/34kWh battery pack and a 270V/203Wh UC pack. The proposed online energy management controller effectively splits the load demand with high power efficiency and also effectively reduces the battery peak current. More importantly, a 38V-385Wh battery and a 16V-2.06Wh UC HESS hardware prototype and a real-time experiment platform has been developed. The real-time experiment results have successfully validated the real-time implementation feasibility and effectiveness of the real-time controller design for the battery-UC HESS. A battery State-of-Health (SoH) estimation model is developed as a performance metric to evaluate the battery cycle life extension effect. It is estimated that the proposed online energy management controller can extend the battery cycle life by over 60%.

Influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes

Introduction: Studies have shown that oxidative stress, found in patients with type 2 diabetes, may be due to changes in the metabolism of minerals, such as magnesium and iron. Data related to compartmentalization of these minerals in diabetes are scarce and controversial. Objective: This study assessed the influence of magnesium on biochemical parameters of iron and oxidative stress in patients with type 2 diabetes. Methods: A case-control study in male and female subjects aged 27-59 years, divided into two groups: type 2 diabetes (n=40) and control (n=48). Intake of magnesium and iron was assessed by three-day food record. Plasma, erythrocyte and urinary levels of magnesium, serum iron, ferritin, total iron binding capacity, fasting glucose, glycated hemoglobin, insulin, creatinine clearance and plasma thiobarbituric acid reactive substances (TBARS) were analyzed. Results and Discussion: Magnesium intake and plasma magnesium were lower in diabetic subjects. There was low urinary magnesium excretion, with no difference between groups. Although normal, the diabetic group had lower serum iron and ferritin concentrations compared to control subjects. Plasma TBARS in diabetic patients was higher than control while creatinine clearance was lower. An inverse correlation between erythrocyte magnesium and serum iron and ferritin was observed in the diabetes group. Conclusions: Diabetes induced hypomagnesemia and this, associated with chronic hyperglycemia, may have enhanced oxidative stress. Erythrocyte magnesium may have contributed to prevent iron overload and worsening of oxidative stress and hyperglycemic status.

Volumetric interactions of a series of α-amino acids in aqueous magnesium chloride solutions at 278.15, 288.15, 298.15, and 308.15 K

In this work, the partial molar volumes of glycine, l-alanine, l-valine, l-serine, and l-threonine in aqueous solutions of magnesium chloride at 0.0, 0.1, 0.3, 0.7, and 1.0 molal are addressed between 278.15 and 308.15 K. Volumes of transfer were obtained, following the rank serine > glycine a parts per thousand threonine > alanine > valine. Differently, the hydration numbers follow the sequence serine > valine > alanine > threonine > glycine, and dehydration of the amino acids is observed, rising the temperature or salt molality. The data suggest that interactions are mainly pairwise, between the ions and charged/hydrophilic groups of the amino acids. Within the Friedman and Krishnan formalism, a group-contribution scheme has been successfully applied to the pairwise volumetric interaction coefficient. Finally, the dehydration effect of MgCl2 on glycine, alanine, and serine has been predicted applying empirical correlations developed before, showing satisfactory results.

Plan of the entrance of Barataria with a projected battery proposed by Lt. Coll. G.T. Ross. No. 9 Rapport May 3d 1813 /

Relief shown pictorially. Depths shown by soundings.