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Is the meander growth in the Brazil Current system off Southeast Brazil due to baroclinic instability?

SILVEIRA, I. C. A. da; LIMA, J. A. M.; SCHMIDT, A. C. K.; CECCOPIERI, W.; SARTORI, A.; FRANSCISCO, C. P. F.; FONTES, R. F. C.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.23%
Temporally-growing frontal meandering and occasional eddy-shedding is observed in the Brazil Current (BC) as it flows adjacent to the Brazilian Coast. No study of the dynamics of this phenomenon has been conducted to date in the region between 22 degrees S and 25 degrees S. Within this latitude range, the flow over the intermediate continental slope is marked by a current inversion at a depth that is associated with the Intermediate Western Boundary Current (IWBC). A time series analysis of 10-current-meter mooring data was used to describe a mean vertical profile for the BC-IWBC jet and a typical meander vertical structure. The latter was obtained by an empirical orthogonal function (EOF) analysis that showed a single mode explaining 82% of the total variance. This mode structure decayed sharply with depth, revealing that the meandering is much more vigorous within the BC domain than it is in the IWBC region. As the spectral analysis of the mode amplitude time series revealed no significant periods, we searched for dominant wavelengths. This search was done via a spatial EOF analysis on 51 thermal front patterns derived from digitized AVHRR images. Four modes were statistically significant at the 95% confidence level. Modes 3 and 4...

Instrumentos de avaliação para limitações funcionais associadas à instabilidade crônica de tornozelo: uma revisão sistemática da literatura; Assessment instruments for chronic ankle instability: a systematic review of literature

Suda, Eneida Yuri; Coelho, Ana Tereza
Fonte: Universidade de São Paulo Publicador: Universidade de São Paulo
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
36.23%
A instabilidade de tornozelo é definida como a sua tendência para sofrer falseios e entorses de repetição após a ocorrência de entorse lateral. Como a presença de instabilidade é definida por meio das queixas relatadas pelo indivíduo, apresenta caráter subjetivo, sendo importante identificar o melhor instrumento de avaliação para a determinação de sua presença e/ou gravidade. O objetivo deste estudo foi revisar, de forma sistemática, instrumentos de avaliação concebidos para pacientes com instabilidade crônica de tornozelo. Foram realizadas pesquisas bibliográficas nas bases de dados PubMed, Embase, BVS, LILACS e SciELO para identificar os instrumentos elegíveis. No total, seis estudos foram incluídos e apresentaram cinco instrumentos diferentes - Foot and Ankle Disability Index (FADI), Ankle Joint Functional Assessment Tool (AJFAT), Foot and Ankle Ability Measure (FAAM), Ankle Joint Functional Assessment Tool (AII) e Cumberland Ankle Instability Tool (CAIT). Foram encontrados instrumentos com qualidade que detectam limitações funcionais em indivíduos com instabilidade crônica de tornozelo, não sendo instrumentos válidos para diagnóstico de instabilidade. O CAIT mostrou-se a ferramenta mais completa, mas não foi validada em uma população específica de indivíduos com condição de instabilidade do tornozelo. Observa-se a necessidade de mais estudos clinimétricamente válidos a fim de atestar a sua validade para se obter uma ferramenta eficaz e completa da instabilidade funcional do tornozelo.

Análise eletromiográfica comparativa de tornozelo durante a aterrissagem em jogadores de vôlei com instabilidade crônica; Comparative electromyographic analysis of ankle muscles during landing in volleyball players with chronic instability

Suda, Eneida Yuri
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/09/2006 PT
Relevância na Pesquisa
36.23%
O objetivo desse estudo foi analisar a atividade eletromiográfica dos músculos tibial anterior (TA), fibular longo (FL) e gastrocnêmio lateral (GL) durante a aterrissagem após o bloqueio em jogadores de vôlei com instabilidade funcional (IF) de tornozelo. Foi analisada a atividade de 21 sujeitos com IF e 19 controles entre o desprendimento do solo e 200ms após o impacto. Os resultados mostraram padrões de ativação muscular que podem predispor o atleta à condição de instabilidade. Em indivíduos com IF, o TA e o FL apresentaram picos máximos de ativação mais tardios no ciclo de movimento, sendo que o TA apresentou maior valor de RMS após a aterrissagem (intervalo de 200ms após o impacto), e o FL, menor valor de RMS pré-terrissagem (intervalo de 100ms antes do impacto). A lém disso, no grupo controle o TA é ativado após o FL e o GL, enquanto no grupo com IF os três músculos ativam de forma praticamente simultânea, pois o GL apresenta um início de atividade muscular mais tardio.; The purpose of this study was to compare electromyiographic activity (EMG) from peroneus longus (PL), tibialis anterior (TA) and gastrocnemius lateralis (GL) of volleyball athletes with and without functional ankle instability (FI) during landing after blocking maneuver. EMG from take-off to 200ms after impact was acquired for 21 athletes with FI and 19 healthy ones. Results showed that FI subjects have a muscle activity that predisposes them to ankle sprains: time of maximum peak occurrence was later for TA and PL...

Aeroacústica e instabilidades de uma camada de mistura compressível; Flow instability and aeroacoustics of a compressible mixing layer

Colaciti, Alysson Kennerly
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/02/2009 PT
Relevância na Pesquisa
36.23%
Tanto os motores turbo-jato quanto os turbo-fan, são os maiores responsáveis pela geração de ruído durante a decolagem, segmento de subida e de aceleração de uma aeronave. Devido a isto, o problema de ruído em jatos vem sendo intensamente investigado ao longo dos últimos anos. Já na fase do pouso, o slat é uma das fontes de ruído mais importantes. Para este caso, na maioria das aplicações práticas, existe o descolamento da camada limite no intradorso do slat a partir de onde se desenvolve uma camada de mistura. Ainda assim, existem inúmeros aspectos de tais escoamentos que precisam de investigação. Uma abordagem frequentemente feita para o estudo da instabilidade hidrodinâmica e ruído em jatos é o estudo de metade do jato. A estratégia consiste em estudar os fenômenos na camada de mistura, o que é uma aproximação razoável quando o jato tem diâmetro muito grande comparado à espessura da camada cisalhante que se desenvolve nas bordas do jato. Assim, alguns aspectos do ruído gerado pelos modos axi-simétricos de instabilidade são em grande parte reproduzidos. Um aspecto aparentemente jamais estudado antes é o efeito do emparelhamento de vórtices de diferentes geometrias na camada de mistura. Caso o efeito da modulação dos vórtices produzisse um padrão de ruído com características diferentes no emparelhamento...

Energetics, baroclinic instability and models of vertical structure in the Brazil Current region (22S-28S); Energética, instabilidade baroclínica e modelos de estrutura vertical na região da Corrente do Brasil (22S-28S)

Rocha, César Barbedo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/07/2013 EN
Relevância na Pesquisa
36.23%
We use four current meter mooring records and quasi-synoptic hydrographic observations in conjunction with a one-dimensional quasi-geostrophic (QG) linear stability model to investigate the downstream changes in the Brazil Current (BC) System off the southeast Brazil (22°S-28°S) as well as its implications. The dataset depicts the downstream thickening of the BC: Its vertical extension increases from 350 m at 22.7°S to 800 m at 27.9°S. Most of this deepening occurs between 25.5°S and 27.9°S, and it is likely linked to the Santos bifurcation. To the south of that bifurcation, the BC transport is increased by at least 5 Sv. Moreover, the analysis of the water column average kinetic energy (IKE) and its barotropic/baroclinic partition show that the Santos bifurcation is associated with a substantial increase in the barotropic component of the BC System: The IKE is, on average, 70 % baroclinic to the north and becomes 63 % barotropic to the south of that bifurcation. The water column average eddy kinetic energy (IEKE) and its ratio to the IKE quantitatively reveal the conspicuous mesoscale activity associated to the BC off the southeast Brazil; accordingly, the IEKE accounts for (30-60)% of the IKE. The linear stability model predicts southwestward-propagating fastest-growing waves [~(180-190) km] within 25.5°S-27.9°S and quasi-standing most-unstable waves (~230 km) at 22.7°S...

O papel do miR-100 na proliferação, indução da apoptose e instabilidade cromossômica em linhagens celulares de câncer de bexiga e próstata; The role of miR-100 on proliferation, induction of apoptosis and chromosomal instability in bladder and prostate cancer cell lines

Morais, Denis Reis
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/10/2013 PT
Relevância na Pesquisa
36.23%
Introdução: O câncer de próstata (CaP) é o tumor sólido mais diagnosticado no homem atualmente, e a sexta ocorrência mais frequente de casos novos de neoplasia maligna no mundo, sendo a segunda causa de óbito por câncer. O câncer de bexiga (CaB) é a segunda neoplasia maligna mais comum e a segunda em causa de óbito entre os tumores genito-urinários. Mundialmente o CaB é responsável por aproximadamente 386.000 novos casos e 150.000 óbitos por ano. O conhecimento das alterações em processos celulares envolvidos na sua carcinogênese nos permite melhor compreensão da patogênese dessas neoplasias, subsidiando, assim, mais efetivamente, o planejamento de estratégias de prevenção, diagnóstico e tratamento. Micro RNA (miRNA) são pequenas sequências não codificantes de RNA que possuem grande papel no controle da expressão dos genes, inibindo a tradução da proteína ou promovendo a degradação do RNA mensageiro (RNAm). Os miRNA estão envolvidos em vários processos celulares fisiológicos e patológicos, incluindo o câncer, onde podem atuar como oncogenes (oncomiR) ou como supressores de tumor (tsmiR). Previamente demonstramos que níveis elevados de miR-100 estão relacionados a recidiva bioquímica pós-prostatectomia radical enquanto no carcinoma urotelial de bexiga de baixo grau ocorre subexpressão desse miRNA. Objetivo: O estudo pretende analisar o papel do miR-100 na regulação de seus supostos genes alvo SMARCA5...

Is the meander growth in the Brazil Current system off Southeast Brazil due to baroclinic instability?

da Silveira, I. C. A.; Lima, J. A. M.; Schmidt, A. C. K.; Ceccopieri, W.; Sartori, A.; Franscisco, C. P. F.; Fontes, R. F. C.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 187-207
ENG
Relevância na Pesquisa
36.23%
Temporally-growing frontal meandering and occasional eddy-shedding is observed in the Brazil Current (BC) as it flows adjacent to the Brazilian Coast. No study of the dynamics of this phenomenon has been conducted to date in the region between 22 degrees S and 25 degrees S. Within this latitude range, the flow over the intermediate continental slope is marked by a current inversion at a depth that is associated with the Intermediate Western Boundary Current (IWBC). A time series analysis of 10-current-meter mooring data was used to describe a mean vertical profile for the BC-IWBC jet and a typical meander vertical structure. The latter was obtained by an empirical orthogonal function (EOF) analysis that showed a single mode explaining 82% of the total variance. This mode structure decayed sharply with depth, revealing that the meandering is much more vigorous within the BC domain than it is in the IWBC region. As the spectral analysis of the mode amplitude time series revealed no significant periods, we searched for dominant wavelengths. This search was done via a spatial EOF analysis on 51 thermal front patterns derived from digitized AVHRR images. Four modes were statistically significant at the 95% confidence level. Modes 3 and 4...

Does political instability lead to higher inflation? a panel data analysis

Veiga, Francisco José; Aisen, Ari
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2005 ENG
Relevância na Pesquisa
36.23%
Economists generally accept the proposition that high inflation rates generate inefficiencies that reduce society’s welfare and economic growth. However, determining the causes of the worldwide diversity of inflationary experiences is an important challenge not yet satisfactorily confronted by the profession. Based on a dataset covering around 100 countries for the period 1960-1999 and using modern panel data econometric techniques to control for endogeneity, this paper shows that a higher degree of political instability is associated with higher inflation. The paper also draws relevant policy implications for the optimal design of inflation stabilization programs and of the institutions favorable to price stability.

Genetic instability of commercial Saccharomyces cerevisiae strains recovered from vineyard’s microflora

Schuller, Dorit; Alves, Hugo; Cambon, Brigitte; Dequin, Sylvie; Casal, Margarida
Fonte: Sociedade Portuguesa de Microbiologia e Sociedade Portuguesa de Biotecnologia Publicador: Sociedade Portuguesa de Microbiologia e Sociedade Portuguesa de Biotecnologia
Tipo: Conferência ou Objeto de Conferência
Publicado em /12/2005 ENG
Relevância na Pesquisa
36.23%
From spontaneous fermentations carried out with grapes collected in vineyards from the Vinho Verde Region, 101 isolates were recovered whose mitochondrial DNA restriction length polymorphism (mtDNA RFLP) were identical to strain Zymaflore VL1, a commercial strain (Lallemand) that has been used by the wineries in the last years. Genetic polymorphisms were evaluated by microsatellite analysis, interdelta sequence analysis and chromosomal karyotyping comparatively to those of 30 isolates of the original commercialized strain. Our data show that the recovered commercial yeast isolates present a considerable genetic instability that can be assessed by distinct methods. Microsatellite allelic polymorphisms were found in 12 natural isolates, two of them were characterized by complete loss of heterozygosity, whereas their chromosomal constitution showed a loss of structural heteromorphism. Major changes of chromosomal patterns were found among the natural isolates, apparent by the absence or changed position of bands in the presumable region of chromosomes VI and III. Interdelta amplification patterns depended on the primer pair used, and changes were apparent by additional bands. Whether these changes are associated with the yeast’s permanence in natural environments is subject of current investigations.; Financially supported by the programs POCI 2010 (FEDER/FCT...

Does political instability lead to higher inflation? a panel data analysis

Veiga, Francisco José; Aisen, Ari
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2005 ENG
Relevância na Pesquisa
36.23%
Economists generally accept the proposition that high inflation rates generate inefficiencies that reduce society’s welfare and economic growth. However, determining the causes of the worldwide diversity of inflationary experiences is an important challenge not yet satisfactorily confronted by the profession. Based on a dataset covering around 100 countries for the period 1960-1999 and using modern panel data econometric techniques to control for endogeneity, this paper shows that a higher degree of political instability is associated with higher inflation. The paper also draws relevant policy implications for the optimal design of inflation stabilization programs and of the institutions favorable to price stability.; Fundação para a Ciência e a Tecnologia (FCT)

Genetic instability of a commercial Saccharomyces cerevisiae strain

Schuller, Dorit; Alves, Hugo; Cambon, Brigitte; Dequin, Sylvie; Casal, Margarida
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /04/2006 POR
Relevância na Pesquisa
36.23%
Resumo e slides da comunicação oral apresentada no encontro científico "XXXII Jornadas Portuguesas de Genética" Vila Real, Portugal, 2006.; The usefulness of four genetic fingerprinting methods (interdelta sequence typing, mitochondrial DNA restriction length polymorphism (mtDNA RFLP), chromosomal karyotyping and microsatellite analysis) was assessed in order to detect a commercial yeast strain (Zymaflore VL1, Lallemand). From 54 spontaneous fermentations performed with grapes collected in 18 the Vinho Verde Wine Region in northwest Portugal, 101 isolates were recovered whose mtDNA RFLP were identical to strain Zymaflore VL1. Evaluation of polymorphisms was performed in comparison to 30 isolates of the corresponding original commercialized strain. Microsatellite allelic polymorphisms were found in 12 natural isolates, two of them were characterized by complete loss of heterozygosity, whereas their chromosomal constitution showed a loss of structural heteromorphism. Major changes of chromosomal patterns were found among the natural isolates, apparent by the absence or changed position of bands in the presumable region of chromosomes VI and III. Interdelta amplification patterns depended on the primer pair used, and changes were apparent by additional bands. No correlations were found between interdelta sequence amplification patterns and chromosomal profiles or microsatellite typing patterns. The present data show that commercial yeast strains present a considerable genetic instability that can be assessed by distinct methods. Whether these changes are associated with the yeast’s permanence in natural environments is subject of current investigations.; Este estudo foi desenvolvido no âmbito do projecto ENOSAFE (Nº 762...

Political instability and inflation volatility

Veiga, Francisco José; Aisen, Ari
Fonte: Universidade do Minho. Núcleo de Investigação em Políticas Económicas Publicador: Universidade do Minho. Núcleo de Investigação em Políticas Económicas
Tipo: Trabalho em Andamento
Publicado em //2006 ENG
Relevância na Pesquisa
36.23%
The purpose of this paper is to empirically determine the causes of the worldwide diversity of inflation volatility. We show that higher degrees of political instability, ideological polarization and political fragmentation are associated with higher inflation volatility.

Early carboniferous wrenching, exhumation of high-grade metamorphic rocks and basin instability in SW Iberia: Constraints derived from structural geology and U–Pb and 40Ar–39Ar geochronology

Pereira, M. Francisco; Chichorro, M.; Silva, J. Brandão; Ordonez-Casado, B.; Lee, James K.W.; Williams, Ian S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.23%
New U–Pb and 40Ar–39Ar geochronology and structural data from high- tomedium grade metamorphic shear zones of the Ossa-Morena Zone, and structural data from Early Carboniferous basins (Ossa-Morena Zone and South-Portuguese Zone), place additional constraints on the Variscan tectonics in SW Iberia. A zircon U–Pb age of 465±14Ma (Middle Ordovician) measured on migmatite from the Coimbra–Cordoba shear zone is interpreted as the age of protolith crystallization. This age determination revises the information contained in the geological map of Portugal, in which these rocks were considered to be Proterozoic in age. This paper describes the evolution of Variscan wrench tectonics related to the development of shear zones, exhumation of deep crustal rocks and emplacement of magma in the Ossa-Morena Zone basement. In the Coimbra–Cordoba shear zone (transpressional), migmatites were rapidly exhumed from a depth of 42.5km to 16.6km over a period of ca. 10Ma in the Viséan (ca. 340–330Ma), indicating oblique slip exhumation rates of 8.5 to 10.6mm/yr (Campo Maior migmatites) and 3.2mm/yr (Ouguela gneisses) respectively. In the Évora Massif, the gneisses of the Boa Fé shear zone (transtensional) were exhumed from 18.5 to 7.4km depth in the period ca. 344–334Ma (Viséan)...

São Tomé and Príncipe: Political Instability Continues

Seibert, Gerhard
Fonte: IPRIS Publicador: IPRIS
Tipo: Outros
Publicado em /01/2013 ENG
Relevância na Pesquisa
36.23%
The recent political crisis provoked by the controversial dismissal of Patrice Trovoada’s minority government by a censure motion has again drawn the attention to politics in this small impoverished African island republic that has been marked by political instability since the introduction of a democratic constitution based on the Portuguese semi-presidential regime in 1990. Following the end of Miguel Trovoada’s ten-year presidency in 2001 his son Patrice has become one of the principal political competitors in São Tomé and Príncipe, while his father retired from national politics and, in 2009 has become executive secretary of the Gulf of Guinea Commission.

Postural instability in Parkinson?s disease ? 120 years after Charcot?s death

Teive,Hélio Afonso Ghizoni; Munhoz,Renato Puppi
Fonte: Academia Brasileira de Neurologia - ABNEURO Publicador: Academia Brasileira de Neurologia - ABNEURO
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 EN
Relevância na Pesquisa
36.23%
The authors present the original Charcot’s description of postural instability in Parkinson’s disease as well as the evolution of this sign after 120 years of Charcot’s death.

Genomic instability in patients with type 2 diabetes mellitus on hemodialysis

Palazzo,Roberta Passos; Bagatini,Pamela Brambilla; Schefer,Patrícia Brandt; Andrade,Fabiana Michelsen de; Maluf,Sharbel Weidner
Fonte: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular Publicador: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
Relevância na Pesquisa
36.23%
OBJECTIVE: A previous study by our research group evaluated the levels of DNA damage using the comet assay in hemodialysis patients with type 2 diabetes mellitus. The same blood samples were also evaluated using the cytochalasin B micronucleus assay. A comparison of the results of the two assays is presented here. METHODS: Whole blood samples were collected from 22 type 2 diabetes mellitus patients on hemodialysis and from 22 control subjects. Samples were collected from patients early in the morning on Mondays, before the first weekly hemodialysis session. The cytokinesis-block micronucleus assay (CBMN) was used to evaluate genomic instability. RESULTS: The frequencies of micronuclei and nuclear buds were higher in patients than in controls (p-value = 0.001 and p-value < 0.001, respectively). There was a correlation between the frequency of micronuclei and DNA damage with the results of the comet assay (p-value < 0.001). The difference in the frequency of micronuclei and nuclear buds between patients and controls was more pronounced in the group with higher median comet values than in the group with lower comet values. CONCLUSIONS: Our results suggest that the increased rates of DNA damage as measured by the comet assay and influenced by the weekly routine therapy of these patients has a mutagenic effect...

Dynamic instability of imperfect laminated sandwich plates with in-plane partial edge load

Chakrabarti,Anupam; Sheikh,Abdul Hamid
Fonte: Associação Brasileira de Ciências Mecânicas Publicador: Associação Brasileira de Ciências Mecânicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
36.23%
Dynamic instability of laminated sandwich plates having inter-laminar imperfections with in-plane partial edge loading is studied for the first time using an efficient finite element plate model. The plate model is based on a refined higher order shear deformation plate theory, where the transverse shear stresses are continuous at the layer interfaces with stress free conditions at plate top and bottom surfaces. A linear spring-layer model is used to model the inter-laminar imperfection by considering in-plane displacement jumps at the interfaces. Interestingly the plate model having all these refined features requires unknowns at the reference plane only. However, this theory requires C1 continuity of transverse displacement (w) i.e., w and its derivatives should be continuous at the common edges between two elements, which is difficult to satisfy arbitrarily in any existing finite element. To deal with this, a new triangular element developed by the authors is used in the present paper.

Application of Iteration Perturbation Method in studying dynamic pull-in instability of micro-beams

Sedighi,Hamid M.; Daneshmand,Farhang; Yaghootian,Amin
Fonte: Associação Brasileira de Ciências Mecânicas Publicador: Associação Brasileira de Ciências Mecânicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
36.23%
In the present study, dynamic pull-in instability of electrostatically-actuated micro-beams is investigated through proposing the nonlinear frequency amplitude relationship. An approximate analytical expression of the fundamental natural frequency is presented by modern asymptotic approach namely Iteration Perturbation Method (IPM). Influences of vibrational amplitude as well as different parameters on dynamic pull-in voltage are investigated. It is demonstrated that two terms in series expansions is sufficient to produce an acceptable solution of the mentioned microstructure. The simulations from numerical methods verify the validity of the analytical procedure.

Modeling the pull-in instability of the CNT-based probe/actuator under the Coulomb force and the van der Waals attraction

Koochi,Ali; Fazli,Norodin; Rach,Randolph; MohamadrezaAbadyan,
Fonte: Associação Brasileira de Ciências Mecânicas Publicador: Associação Brasileira de Ciências Mecânicas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
36.23%
Carbon nano-tube (CNT) is applied to fabricate nano-probes, nano-switches, nano-sensors and nano- actuators. In this paper, a continuum model is employed to obtain the nonlinear constitutive equation and pull-in instability of CNT-based probe/actuators, which includes the effect of electrostatic interaction and intermolecular van der Waals (vdW) forces. The modified Adomian decomposition (MAD) method is applied to solve the nonlinear governing equation of the CNT-based actuator. Furthermore a simple and useful lumped parameter model was developed to investigate trends for various pull-in parameters. The influence of the vdW force and the geometrical dimensionless parameter on the pull-in deflection and voltage of the system is investigated. The obtained results are compared with those available in the literature as well as numerical solutions. The results demonstrate that our developed continuum based model is in good agreement with experimental results.

3D point cloud in the evaluation of processes that generate instability of the lumbar spine

Gallegos,José Luis González; Gómez,Tania del Socorro Vergara; Hernández,Armando García; Martínez,Ana Karen Ibarra; González,Alejandro García; Aguilar,Rita Quetziquel Fuentes; Ávila,José María Jiménez
Fonte: Sociedade Brasileira de Coluna Publicador: Sociedade Brasileira de Coluna
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2015 EN
Relevância na Pesquisa
36.23%
OBJECTIVE: To integrate patients with lumbar instability in a multisensor platform in the process of assessment and diagnosis, assigning quantitative parameters for the sagittal balance (SB) and muscle function. METHODS: Experimental study involving adult patients diagnosed with diseases that cause alterations in the SB, that were or were not submitted to surgery with posterior instrumentation and fusion. Each patient underwent anthropometric measurements in body composition scale; a kinesiological analysis using a multisensor platform consisting of depth camera to static/dynamic analysis for the quantitative measurement of SB, and surface electromyography to capture the level of abdominal and lumbar muscles activation and through flexion and extension. RESULTS: Seven adult patients: five females (62.5%)and two men (37.5%) with a mean age 48 years. Images with depth cameras resulted in a SB of from -6.4 to +5.3cm (average -5.7cm). In individuals with positive sagittal balance the percentage of activation (PA) of the abdominal muscles was 58.5% and the lower back lumbar was 75.25%; patients with negative SB integrated the PA of the abdominal muscles of 70.25% and lumbar of 65%; the patient with neutral SB exhibited activation of the abdominal muscles of 87.75% and lumbar muscles of 78.25%. CONCLUSIONS: We observed a trend towards positive SB in patients with overweight and obesity by BMI...