Osseointegration assessment of chairside argon-based nonthermal plasma-treated Ca-P coated dental implants

This study investigated the effect of an Argon-based nonthermal plasma (NTP) surface treatment-operated chairside at atmospheric pressure conditions applied immediately prior to dental implant placement in a canine model. Surfaces investigated comprised: Calcium-Phosphate (CaP) and CaP + NTP (CaP-Plasma). Surface energy was characterized by the Owens-Wendt-Rabel-Kaelble method and chemistry by X-ray photoelectron spectroscopy (XPS). Six adult beagles dogs received 2 plateau-root form implants (n = 1 each surface) in each radii, providing implants that remained 1 and 3 weeks in vivo. Histometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed by Kruskall-Wallis (95% level of significance) and Dunn's post-hoc test. The XPS analysis showed peaks of Ca, C, O, and P for the CaP and CaP-Plasma surfaces. Both surfaces presented carbon primarily as hydro-carbon (CAC, CAH) with lower levels of oxidized carbon forms. The CaP surface presented atomic percent values of 38, 42, 11, and 7 for C, O, Ca, and P, respectively, and the CaPPlasma presented increases in O, Ca, and P atomic percent levels at 53, 12, and 13, respectively, in addition to a decrease in C content at 18 atomic percent. At 1 week no difference was found in histometric parameters between groups. At 3 weeks significantly higher BIC and BAFO were observed for CaPPlasma treated surfaces. Surface elemental chemistry was modified by the Ar-based NTP. Ar-based NTP improved bone formation around plateau-root form implants at 3 weeks compared with CaP treatment alone. © 2012 Wiley Periodicals, Inc.

Multimodal exercise intervention improves frontal cognitive functions and gait in Alzheimer's disease: A controlled trial

Aim: The objective of the present study was to investigate the effect of a multimodal exercise intervention on frontal cognitive functions and kinematic gait parameters in patients with Alzheimer's disease. Methods: A sample of elderly patients with Alzheimer's disease (n=27) were assigned to a training group (n=14; aged 78.0±7.3years) and a control group (n=13; aged 77.1±7.4years). Multimodal exercise intervention includes motor activities and cognitive tasks simultaneously. The participants attended a 1-h session three times a week for 16weeks, and the control participants maintained their regular daily activities during the same period. The frontal cognitive functions were evaluated using the Frontal Assessment Battery, the Clock Drawing Test and the Symbol Search Subtest. The kinematic parameters of gait-cadence, stride length and stride speed were analyzed under two conditions: (i) free gait (single task); and (ii) gait with frontal cognitive task (walking and counting down from 20 - dual task). Results and discussion: The patients in the intervention group significantly increased the scores in frontal cognitive variables, Frontal Assessment Battery (P<0.001) and Symbol Search Subtest (P<0.001) after the 16-week period. The control group decreased the scores in the Clock Drawing Test (P=0.001) and increased the number of counting errors during the dual task (P=0.008) after the same period. Conclusion: The multimodal exercise intervention improved the frontal cognitive functions in patients with Alzheimer's disease. © 2012 Japan Geriatrics Society.

Diagnóstico de falhas via observadores de estado com excitações desconhecidas, identificadas via funções ortogonais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso de marcadores microssatélites para estimar parentescos dentro de progênies de polinização aberta de espécies arbóreas dióicas: um estudo de caso de Myracrodruon urundeuva (F.F. & M.F. Allemão)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Redespacho de reativos como ação corretiva para alívio de sobrecargas em Redes de transmissão

Pós-graduação em Engenharia Elétrica - FEIS

Projeto multicritério de filtros harmônicos passivos para instalações industriais utilizando técnicas de inteligência computacional

Devido ao auge do crescimento industrial na Região Norte e, em especial, o Pólo Industrial de Manaus (PIM), são necessários obter ferramentas matemáticas que facilitem ao especialista tomar decisões sobre a seleção e dimensionamento dos filtros harmônicos que proporcionam neutralizar os efeitos prejudiciais dos harmônicos gerados pelas cargas não lineares da indústria e alcançar conformidade com os padrões das normas de qualidade de energia correspondentes. Além disso, como os filtros harmônicos passivos têm a capacidade de gerar potência reativa à rede, estes meios são eficazes compensadores de potência reativa e, portanto, podem conseguir uma economia significativa no faturamento de energia elétrica consumida por essas instalações industriais. Esta tese tem como objetivo geral desenvolver um método matemático e uma ferramenta computacional para a seleção da configuração e parâmetros do projeto de um conjunto de filtros harmônicos passivos para sistemas elétricos industriais. Nesta ótica, o problema de otimização da compensação de harmônicos por meio de filtros passivos foi formulado como um problema multiobjetivo que considera tanto os objetivos da redução da distorção harmônica como da efetividade econômica do projeto considerando as características das tarifas brasileiras. Todavia, a formulação apresentada considera as restrições relevantes impostas pelas normas brasileiras e estrangeiras. A solução computacional para este problema foi conseguida, usando o algoritmo genético NSGA-II que determina um conjunto de soluções ótimas de Pareto (Fronteira) que permitem ao projetista escolher as soluções mais adequadas para o problema. Por conseguinte, a ferramenta computacional desenvolvida tem várias novidades como: não só calcula os parâmetros que caracterizam os filtros, como também seleciona o tipo de configuração e o número de ramos do filtro em cada barra candidata de acordo com um conjunto de configurações pré-estabelecidas; têm implementada duas normas para a avaliação das restrições de qualidade de energia (Prodist-Módulo 8 e IEEE 519-92) que podem ser selecionadas pelo usuário; determina soluções com bons indicadores de desempenho para vários cenários característicos e não característicos do sistema que permitem a representação das as variações diárias da carga; das variações dos parâmetros do sistema e dos filtros; avalia o custo das contas de energia numa rede elétrica industrial que tem diferentes condições de operação (cenários característicos); e avalia o efeito econômico de filtros de harmônicos como compensadores de potência reativa. Para desenvolver a ferramenta computacional adequada desta tese, foi empregado um modelo trifásico em coordenadas de fase para redes de energia elétrica industriais e de serviços onde foram feitos vários programas utilizando várias ferramentas computacionais adicionais. Estas ferramentas compreendem um programa de varredura de freqüência, um programa do fluxo de harmônicos por injeção de correntes e um programa de fluxo de potência à freqüência fundamental. Os resultados positivos desta tese, a partir da análise de vários exemplos práticos, mostram as vantagens do método desenvolvido.

The dynamic behavior of a cantilever beam coupled to a non-ideal unbalanced motor through numerical and experimental analysis

An excitation force that is not influenced by the system state is said to be an ideal energy source. In real situations, a direct and feedback coupling between the excitation source and the system must always exist at a certain level. This manifestation of the law of conservation of energy is known as the Sommerfeld effect. In the case of obtaining a mathematical model for such a system, additional equations are usually necessary to describe the vibration sources with limited power and its coupling with the mechanical system. In this work, a cantilever beam and a non-ideal DC motor fixed to its free end are analyzed. The motor has an unbalanced mass that provides excitation to the system which is proportional to the current applied to the motor. During the coast up operation of the motor, if the drive power is increased slowly, making the excitation frequency pass through the first natural frequency of the beam, the DC motor speed will remain the same until it suddenly jumps to a much higher value (simultaneously its amplitude jumps to a much lower value) upon exceeding a critical input power. It was found that the Sommerfeld effect depends on some system parameters and the motor operational procedures. These parameters are explored to avoid the resonance capture in the Sommerfeld effect. Numerical simulations and experimental tests are used to help gather insight of this dynamic behavior. (C) 2014 Elsevier Ltd. All rights reserved.

Variação temporal e espacial da taxa de sedimentação e das características limnológicas na microbacia do córrego da Barrinha, no município de Pirassununga, SP

Studies regarding the quality and quantity of water have become more and more important because of the increasing negative environmental impacts occurred and their scarcity increase as well. At the Center of Tropical Fish Research (Centro de Pesquisas de Peixes Tropicais - CEPTAlIBAMA) located in the city of Pirassununga, SP, there is a dam named Represa Velha which supplies 128 tanks that are fish hatcheries. This dam takes in part of the Barrinha stream micro-basin where it has been observed strong impacts due to the deforestation of its support forest, as well an the intensive agricultural activities in the neighboring areas. There has been established and distributed 13 points of water-collectors disposed inside the stream and the dam. The water samples were taken from the stream only from its surface because of the low depth and, inside. In the dam, the water samples were taken at the water column, at a 50cm distance over the sediment. In every point of collection inside the dam, it was placed a chamber of sedimentation, vertically in the water column at a 70% height from the total depth. The collections took place during the dry/cold and raining/warm periods of the years 2000 and 2001. Then, it were analyzed the physical, physical-chemical, chemical and micro-biological parameters of the water samples. The obtained results were statistically analyzed throughout the SAS system (Statistical Analisys System). Parameters such as total phosphate, nitrate, nitrite and turbidity were within the established limits for the Class 2 water, according to the n° 20/1986 CONAMA Resolução. However, the total and Escherichia coli coliforms, mainly inside the Barrinha stream, had showed values above of the established limits for the same... (Complete abstract click electronic access below)

A virtual experiment for the detection of specific features in the frequency response of a coupled nonlinear and linear oscillator

This paper presents an investigation into some practical issues that may be present in a real experiment, when trying to validate the theoretical frequency response curve of a two degree-of-freedom nonlinear system consisting of coupled linear and nonlinear oscillators. Some specific features, such as detached resonance curves, have been theoretically predicted in multi degree-of-freedom nonlinear oscillators, when subject to harmonic excitation, and the system parameters have been shown to be fundamental in achieving such features. When based on a simplified model, approximate analytical expression for the frequency response curves may be derived, which may be validated by the numerical solutions. In a real experiment, however, the practical achievability of such features was previously shown to be greatly affected by small disturbances induced by gravity and inertia, which led to some solutions becoming unstable which had been predicted to be stable. In this work a practical system configuration is proposed where such effects are reduced so that the previous limitations are overcome. A virtual experiment is carried out where a detailed multi-body model of the oscillator is assembled and the effects on the system response are investigated.

Transiting exoplanets from the CoRoT space mission XXII. CoRoT-16b: a hot Jupiter with a hint of eccentricity around a faint solar-like star

Aims. We report the discovery of CoRoT-16b, a low density hot jupiter that orbits a faint G5V star (mV = 15.63) in 5.3523 +/- 0.0002 days with slight eccentricity. A fit of the data with no a priori assumptions on the orbit leads to an eccentricity of 0.33 +/- 0.1. We discuss this value and also derive the mass and radius of the planet. Methods. We analyse the photometric transit curve of CoRoT-16 given by the CoRoT satellite, and radial velocity data from the HARPS and HIRES spectrometers. A combined analysis using a Markov chain Monte Carlo algorithm is used to get the system parameters. Results. CoRoT-16b is a 0.535 -0.083/+0.085 M-J, 1.17 -0.14/+0.16 R-J hot Jupiter with a density of 0.44 -0.14/+0.21 g cm(-3). Despite its short orbital distance (0.0618 +/- 0.0015 AU) and the age of the parent star (6.73 +/- 2.8 Gyr), the planet orbit exhibits significantly non-zero eccentricity. This is very uncommon for this type of objects as tidal effects tend to circularise the orbit. This value is discussed taking into account the characteristics of the star and the observation accuracy.

Loudness scattering due to vibro-acoustic model variability

The use of numerical simulation in the design and evaluation of products performance is ever increasing. To a greater extent, such estimates are needed in a early design stage, when physical prototypes are not available. When dealing with vibro-acoustic models, known to be computationally expensive, a question remains, which is related to the accuracy of such models in view of the well-know variability inherent to the mass manufacturing production techniques. In addition, both academia and industry have recently realized the importance of actually listening to a products sound, either by measurements or by virtual sound synthesis, in order to assess its performance. In this work, the scatter of significant parameter variations on a simplified vehicle vibro-acoustic model is calculated on loudness metrics using Monte Carlo analysis. The mapping from the system parameters to sound quality metric is performed by a fully-coupled vibro-acoustic finite element model. Different loudness metrics are used, including overall sound pressure level expressed in dB and Specific Loudness in Sones. Sound quality equivalent sources are used to excite this model and the sound pressure level at the driver's head position is acquired to be evaluated according to sound quality metrics. No significant variation has been perceived when evaluating the system using regular sound pressure level expressed in in dB and dB(A). This happens because of the third-octave filters that averages the results under some frequency bands. On the other hand, Zwicker Loudness presents important variations, arguably, due to the masking effects.

The swelling behaviour of polyelectrolyte networks

Being basic ingredients of numerous daily-life products with significant industrial importance as well as basic building blocks for biomaterials, charged hydrogels continue to pose a series of unanswered challenges for scientists even after decades of practical applications and intensive research efforts. Despite a rather simple internal structure it is mainly the unique combination of short- and long-range forces which render scientific investigations of their characteristic properties to be quite difficult. Hence early on computer simulations were used to link analytical theory and empirical experiments, bridging the gap between the simplifying assumptions of the models and the complexity of real world measurements. Due to the immense numerical effort, even for high performance supercomputers, system sizes and time scales were rather restricted until recently, whereas it only now has become possible to also simulate a network of charged macromolecules. This is the topic of the presented thesis which investigates one of the fundamental and at the same time highly fascinating phenomenon of polymer research: The swelling behaviour of polyelectrolyte networks. For this an extensible simulation package for the research on soft matter systems, ESPResSo for short, was created which puts a particular emphasis on mesoscopic bead-spring-models of complex systems. Highly efficient algorithms and a consistent parallelization reduced the necessary computation time for solving equations of motion even in case of long-ranged electrostatics and large number of particles, allowing to tackle even expensive calculations and applications. Nevertheless, the program has a modular and simple structure, enabling a continuous process of adding new potentials, interactions, degrees of freedom, ensembles, and integrators, while staying easily accessible for newcomers due to a Tcl-script steering level controlling the C-implemented simulation core. Numerous analysis routines provide means to investigate system properties and observables on-the-fly. Even though analytical theories agreed on the modeling of networks in the past years, our numerical MD-simulations show that even in case of simple model systems fundamental theoretical assumptions no longer apply except for a small parameter regime, prohibiting correct predictions of observables. Applying a "microscopic" analysis of the isolated contributions of individual system components, one of the particular strengths of computer simulations, it was then possible to describe the behaviour of charged polymer networks at swelling equilibrium in good solvent and close to the Theta-point by introducing appropriate model modifications. This became possible by enhancing known simple scaling arguments with components deemed crucial in our detailed study, through which a generalized model could be constructed. Herewith an agreement of the final system volume of swollen polyelectrolyte gels with results of computer simulations could be shown successfully over the entire investigated range of parameters, for different network sizes, charge fractions, and interaction strengths. In addition, the "cell under tension" was presented as a self-regulating approach for predicting the amount of swelling based on the used system parameters only. Without the need for measured observables as input, minimizing the free energy alone already allows to determine the the equilibrium behaviour. In poor solvent the shape of the network chains changes considerably, as now their hydrophobicity counteracts the repulsion of like-wise charged monomers and pursues collapsing the polyelectrolytes. Depending on the chosen parameters a fragile balance emerges, giving rise to fascinating geometrical structures such as the so-called pear-necklaces. This behaviour, known from single chain polyelectrolytes under similar environmental conditions and also theoretically predicted, could be detected for the first time for networks as well. An analysis of the total structure factors confirmed first evidences for the existence of such structures found in experimental results.

Bestimmung der Hamaker-Konstanten von polymeren Nanopartikeln in organischen Lösungsmitteln und wässrigen Elektrolytlösungen mittels asymmetrischer Fluss-Feld-Fluss-Fraktionierung

Die zwischen allen Objekten vorhandenen Wechselwirkungen können repulsiver und attraktiver Natur sein. Bei den attraktiven Kräften kommt der Bestimmung von Dispersionskräften eine besondere Bedeutung zu, da sie in allen kolloidalen Systemen vorhanden sind und entscheidenden Einfluss auf die Eigenschaften und Prozesse dieser Systeme nehmen. Eine der Möglichkeiten, Theorie und Experiment zu verbinden, ist die Beschreibung der London-Van der Waals-Wechselwirkung durch die Hamaker-Konstante, welche durch Berechnungen der Wechselwirkungsenergie zwischen Objekten erhalten werden kann. Für die Beschreibung von Oberflächenphänomenen wie Adhäsion, die in Termen der totalen potentiellen Energie zwischen Partikeln und Substrat beschrieben werden, benötigt man exakt bestimmte Hamaker-Konstanten. In der vorliegenden Arbeit wurde die asymmetrische Fluss Feld-Fluss Fraktionierung in Kombination mit einem auf dem Newton-Algorithmus basierenden Iterationsverfahren zur Bestimmung der effektiven Hamaker-Konstanten verschiedener Nanopartikeln sowie Polystyrollatex-Partikel in Toluol bzw. Wasser verwendet. Der Einfluss verschiedener Systemparameter und Partikeleigenschaften wurde im Rahmen der klassischen DLVO-Theorie untersucht.

Application of Submerged Grouted Anchors in Sheet Pile Quay Walls

Sheet pile walls are one of the oldest earth retention systems utilized in civil engineering projects. They are used for various purposes; such as excavation support system, cofferdams, cut-off walls under dams, slope stabilization, waterfront structures, and flood walls. Sheet pile walls are one of the most common types of quay walls used in port construction. The worldwide increases in utilization of large ships for transportation have created an urgent need of deepening the seabed within port areas and consequently the rehabilitation of its wharfs. Several methods can be used to increase the load-carrying capacity of sheet-piling walls. The use of additional anchored tie rods grouted into the backfill soil and arranged along the exposed wall height is one of the most practical and appropriate solutions adopted for stabilization and rehabilitation of the existing quay wall. The Ravenna Port Authority initiated a project to deepen the harbor bottom at selected wharves. An extensive parametric study through the finite element program, PLAXIS 2D, version 2012 was carried out to investigate the enhancement of using submerged grouted anchors technique on the load response of sheet-piling quay wall. The influence of grout-ties area, length of grouted body, anchor inclination and anchor location were considered and evaluated due to the effect of different system parameters. Also a comparative study was conducted by Plaxis 2D and 3D program to investigate the behavior of these sheet pile quay walls in terms of horizontal displacements induced along the sheet pile wall and ground surface settlements as well as the anchor force and calculated factor of safety. Finally, a comprehensive study was carried out by using different constitutive models to simulate the mechanical behavior of the soil to investigate the effect of these two models (Mohr-Coulomb and Hardening Soil) on the behavior of these sheet pile quay walls.

NLGA based Active Control in Aerospace: fault tolerability, disturbance rejection, and parameter estimation

A new control scheme has been presented in this thesis. Based on the NonLinear Geometric Approach, the proposed Active Control System represents a new way to see the reconfigurable controllers for aerospace applications. The presence of the Diagnosis module (providing the estimation of generic signals which, based on the case, can be faults, disturbances or system parameters), mean feature of the depicted Active Control System, is a characteristic shared by three well known control systems: the Active Fault Tolerant Controls, the Indirect Adaptive Controls and the Active Disturbance Rejection Controls. The standard NonLinear Geometric Approach (NLGA) has been accurately investigated and than improved to extend its applicability to more complex models. The standard NLGA procedure has been modified to take account of feasible and estimable sets of unknown signals. Furthermore the application of the Singular Perturbations approximation has led to the solution of Detection and Isolation problems in scenarios too complex to be solved by the standard NLGA. Also the estimation process has been improved, where multiple redundant measuremtent are available, by the introduction of a new algorithm, here called "Least Squares - Sliding Mode". It guarantees optimality, in the sense of the least squares, and finite estimation time, in the sense of the sliding mode. The Active Control System concept has been formalized in two controller: a nonlinear backstepping controller and a nonlinear composite controller. Particularly interesting is the integration, in the controller design, of the estimations coming from the Diagnosis module. Stability proofs are provided for both the control schemes. Finally, different applications in aerospace have been provided to show the applicability and the effectiveness of the proposed NLGA-based Active Control System.