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An Experimental Evaluation of the Experimental Spatial Dynamics Modeling (ESDM) TechniqueStafne, Michael Allan 27 May 1998 (has links)
Relatively new transducers permit the measurement of dynamic response at many structure locations. Included among such transducers is the scanning laser Doppler vibrometer (LDV). A scanning LDV can measure velocity at many structure locations. An important new technique, Experimental Spatial Dynamics Modeling (ESDM), utilizes such spatially dense velocity data. ESDM models continuous, three-dimensional velocity fields using LDV velocity data. Thus, ESDM is a powerful structural dynamics analysis tool that significantly enhances the usefulness of a scanning LDV. However, heretofore, ESDM has not been experimentally evaluated. The results contained herein partially satisfy this need. Specifically, this research evaluated the ability of ESDM to reconstruct velocity response fields with large in-plane components parallel to a surface in the presence of small out-of-plane components transverse to the surface. To fulfill this objective, a test structure was developed and fabricated; the structure had certain dynamic properties which aided ESDM evaluation. Subsequently, the test structure was harmonically excited at a single frequency such that large in-plane and small out-of-plane velocity components were present on a particular surface. LDV and accelerometer data were then collected. Ultimately, velocity results were obtained from the LDV data via ESDM and the accelerometer data. Velocity results derived from the accelerometer data served as an experimental standard against which ESDM results were compared. Result comparisons clearly indicate that ESDM accurately reconstructs surface velocity fields with large in-plane and small out-of-plane components. / Master of Science
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Examination of flow around second-generation controlled diffusion compressor blades in cascade at stallFitzgerald, Kevin D. 06 1900 (has links)
Approved for public release, distribution is unlimited / The flow around second-generation controlled-diffusion blades in cascade at stall was examined experimentally through the use of a two-component laser-Doppler velocimeter. Blade surface pressure measurements were also preformed at mid span on the blades at various Reynolds numbers. Flow visualization techniques were used to observe and record the flow on the surface of the blade. A correlation between the experimental results and computational fluid dynamic predictions was attempted in order to determine the exact nature of the flow as the blades approached stall, to further assist in the development of advanced blade design. The blade surface pressure measurements showed that the mid-span section of the blade was at a lower loading than previously measured at a smaller inlet flow angle. This indicated that the blade section was at stall. The flow visualization highlighted the extent of the three-dimensional flow over the blades. The LDV measurements documented the mid-span boundary layer and wake profiles. / Ensign, United States Navy
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Application de l'holographie acoustique en soufflerie par mesures LDV / Application of acoustic holography in wind tunnel by means of LDV measurementsParisot-Dupuis, Hélène 05 December 2012 (has links)
L’ Holographie acoustique de champ proche (NAH) est une méthode d’imagerie acoustique robuste, mais son application en écoulement peut être limitée par l’utilisation de mesures intrusives de pression ou de vitesse acoustique. Dans cette étude, une procédure holographique applicable en écoulement utilisant des mesures de vitesse non-intrusives est proposée. Cette méthode est basée sur le théorème intégral de Kirchhoff-Helmholtz convecté. La fonction de Green convectée est alors utilisée pour déterminer des propagateurs spatiaux convectés définis dans l’espace réel et incluant l’effet d’un écoulement subsonique uniforme. Les transformées de Fourier discrètes de ces propagateurs permettent alors d’évaluer les champs acoustiques à partir de la mesure du champ de pression ou de vitesse acoustique normale. Le but étant de développer une méthode de caractérisation de sources aéroacoustiques à partir de mesures de vitesse non-intrusives, cette étude se concentre essentiellement sur les propagateurs réels convectés basés sur la mesure de vitesse acoustique. Afin de valider cette procédure,des simulations ont été menées dans le cas de combinaisons de sources monopolaires et dipolaires convectées corrélées ou non. La procédure holographique développée donne de bons résultats par comparaison aux champs acoustiques théoriques. Une comparaison des résultats obtenus par les propagateurs convectés réels, développés dans cette thèse, avec ceux obtenus par leurs formes spectrales, développés par Kwon et al. fin 2010 pour des mesures de pression acoustique, montre l’intérêt d’utiliser la forme réelle pour la reconstruction de la pression acoustique à partir de la mesure de vitesse acoustique normale. L’efficacité de la procédure développée est confirmée par une campagne de mesure en soufflerie avec un haut-parleur affleurant rayonnant au sein d’un écoulement à Mach 0.22, et des mesures non-intrusives effectuées par Vélocimétrie Laser Doppler (LDV). Les champs de vitesse acoustique utilisés pour la procédure holographique sont dans ce cas extraits des mesures LDV par corrélation avec un microphone de référence. La faisabilité de prendre en compte des variations de l’écoulement dans la direction de reconstruction holographique est également vérifiée. / Nearfield Acoustic Holography (NAH) is a powerful acoustic imaging method but its application in flow can be limited by intrusive measurements of acoustic pressure or velocity. In this work, a moving fluid medium NAH procedure using non-intrusive velocity measurements is proposed. This method is based on the convective Kirchhoff-Helmholtz integral formula. The convective Green’s function is then used to derive convective realspace propagators including uniform subsonic airflow effects. Discrete Fourier transforms of these propagators allow then the assessment of acoustic fields from acoustic pressure or normal acoustic velocity measurements. As the aim is to derive an aeroacoustic sources characterisation method from non-inrusive velocity measurements, this study is especially focused on real convective velocity-based propagators. In order to validate this procedure, simulations in the case of combinations of monopolar and dipolar sources correlated or not, radiating invarious uniform subsonic flows, have been performed. NAH provides very favorable results when compared to the theoretical fields. A comparison of results obtained by real convective propagators, developed in this work, and those obtained by the spectral ones, developed by Kwon et al. at the end of 2010 for acoustic pressure measurements, shows the interest of using the real-form for NAH acoustic pressure reconstruction from normal acoustic velocity measurements. The efficiency of the developed procedure is confirmed by a wind tunnel campaign with a flush-mounted loudspeaker radiating in a flow at Mach 0.22 and non-intrusive Laser Doppler Velocimetry (LDV) measurements. Acoustic velocity fields used for the NAH procedure are in this case extracted from LDV measurements by correlation with a reference microphone. The feasibility of taking into account mean flow variations in the direction of NAH reconstruction is also checked.
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Estudo da microcirculação na hanseníase usando videomicroscopia (Microscan) e laser-Doppler associado à iontoforese: um modelo de disautonomia vascular por denervação / Leprosymicrocirculation study using video microscopy (MicroScan ) and laser-Doppler associated with iontophoresis: a model of vascular dysautonome by denervationLivia Cristina de Melo Pino Machado 22 August 2013 (has links)
A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomiamicrocirculatória. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase tuberculóide. Utilizamos a videomicroscopia de campo escuro (Microscan), a análise de Fourier do sinal do laser Doppler para estudo da vasomotricidade e o laser Doppler fluxometria associado à iontoforese de substâncias vasoativas (acetilcolina e nitroprussiato de sódio) para avaliação da reatividade vascular. Sete pacientes portadores de hanseníase tuberculóide, sem outras co-morbidades que pudessem alterar os parâmetros microcirculatórios, foram avaliados pelos métodos descritos e seus resultados foram comparados, com controles realizados nos próprios pacientes em área contralateral com pele sã. Em relação à vasomotricidade foi observada alteração estatisticamente significativa entre os grupos, apenas no componente endotelial. Em relação à iontoforese de substâncias vasoativas não se constatou diferenças entre as manchas e os controles. No Microscan, observamos as maiores alterações. Os resultados apresentados sugerem que, provavelmente devido à alteração inervatória decorrente da hanseníase tuberculóide, estes pacientes apresentam uma alteração quantitativa de vasos e também da reatividade vascular da microcirculação cutânea. / Leprosy is an infectious disease with unique features, among them the fact that it compromises not only the cutaneous and anexial innervation, but also the innervation of the cutaneous microcirculation. Several articles indicate the impact of disautonomy on the microcirculatory level, citing the example of changes in vasomotor level. The present study proposes to evaluate the microvascular reactivity of the cutaneous microcirculation of tuberculoid leprosy. Methods employed in the study were: the sidestream dark field imaging (Microscan), the Fourier analysis of the laser Doppler signal to study vasomotion, and the laser Doppler flowmetry associated to iontophoresis of vasoactive substances (acetylcholine and sodium nitroprusside).Seven patients with tuberculoid leprosy, without any other comorbidity that could modify the microvascular parameters were evaluated and their results were compared with contralateral areas of healthy skin from the same patients.Regarding the vasomotion, statistical significant difference was noticed only in endothelial component, between groups. In the iontophoresis of vasoactive substances, it was not found differences between areas with and without lesions and controls. In the results obtained with the Microscan we have observed the greatest changes. The results suggest that, probably due to changes resulting from denervation of tuberculoid leprosy, these patients have significant quantitative change on vessels and also in the vascular reactivity of the cutaneous microcirculation.
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Estudo da microcirculação na hanseníase usando videomicroscopia (Microscan) e laser-Doppler associado à iontoforese: um modelo de disautonomia vascular por denervação / Leprosymicrocirculation study using video microscopy (MicroScan ) and laser-Doppler associated with iontophoresis: a model of vascular dysautonome by denervationLivia Cristina de Melo Pino Machado 22 August 2013 (has links)
A hanseníase é uma doença infecciosa com características únicas, dentre elas o fato de atingir intensamente a inervação da pele e seus anexos. Entremeando estes anexos, está a microcirculação cutânea, que a principio também tem sua inervação comprometida. Vários artigos apontam para alterações de disautonomiamicrocirculatória. O presente estudo se propõe a avaliar a microcirculação cutânea na hanseníase tuberculóide. Utilizamos a videomicroscopia de campo escuro (Microscan), a análise de Fourier do sinal do laser Doppler para estudo da vasomotricidade e o laser Doppler fluxometria associado à iontoforese de substâncias vasoativas (acetilcolina e nitroprussiato de sódio) para avaliação da reatividade vascular. Sete pacientes portadores de hanseníase tuberculóide, sem outras co-morbidades que pudessem alterar os parâmetros microcirculatórios, foram avaliados pelos métodos descritos e seus resultados foram comparados, com controles realizados nos próprios pacientes em área contralateral com pele sã. Em relação à vasomotricidade foi observada alteração estatisticamente significativa entre os grupos, apenas no componente endotelial. Em relação à iontoforese de substâncias vasoativas não se constatou diferenças entre as manchas e os controles. No Microscan, observamos as maiores alterações. Os resultados apresentados sugerem que, provavelmente devido à alteração inervatória decorrente da hanseníase tuberculóide, estes pacientes apresentam uma alteração quantitativa de vasos e também da reatividade vascular da microcirculação cutânea. / Leprosy is an infectious disease with unique features, among them the fact that it compromises not only the cutaneous and anexial innervation, but also the innervation of the cutaneous microcirculation. Several articles indicate the impact of disautonomy on the microcirculatory level, citing the example of changes in vasomotor level. The present study proposes to evaluate the microvascular reactivity of the cutaneous microcirculation of tuberculoid leprosy. Methods employed in the study were: the sidestream dark field imaging (Microscan), the Fourier analysis of the laser Doppler signal to study vasomotion, and the laser Doppler flowmetry associated to iontophoresis of vasoactive substances (acetylcholine and sodium nitroprusside).Seven patients with tuberculoid leprosy, without any other comorbidity that could modify the microvascular parameters were evaluated and their results were compared with contralateral areas of healthy skin from the same patients.Regarding the vasomotion, statistical significant difference was noticed only in endothelial component, between groups. In the iontophoresis of vasoactive substances, it was not found differences between areas with and without lesions and controls. In the results obtained with the Microscan we have observed the greatest changes. The results suggest that, probably due to changes resulting from denervation of tuberculoid leprosy, these patients have significant quantitative change on vessels and also in the vascular reactivity of the cutaneous microcirculation.
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Efeitos da radiação laser em baixa intensidade na cicatrização de queimaduras de pele. Estudo Laser Doppler fluxométrico e histológico em ratos / Effects of low intensity laser radiation on burned skin healing. a laser doppler flowmetry and histological study in ratsSugayama, Stella Thyemi 28 November 2006 (has links)
Queimaduras severas causam trauma às vítimas, pela perda de líquido corpóreo, injúria no sistema vascular cutâneo e demora na cicatrização das lesões. A irradiação com laser em baixa intensidade vem sendo estudada como tratamento alternativo, por ser uma terapia não-invasiva e capaz de acelerar o processo de cicatrização. O objetivo deste estudo foi avaliar os efeitos do laser de baixa potência (λ = 660 nm) em queimaduras de pele por histomorfometria e fluxometria laser Doppler utilizando duas condições de irradiação. Trinta e seis animais com duas queimaduras criadas por vapor foram divididos em três grupos: no grupo dose fracionada (GF), as lesões foram irradiadas com dose de 1 J/cm2 nos dias 1, 3, 8 e 10; no grupo dose única (GU), as lesões foram irradiadas com dose de 4 J/cm2 no dia 1. O grupo controle (GC) não foi irradiado. O fluxo sanguíneo foi monitorado nos dias 3, 8, 10, 15 e 21 e três animais por grupo foram sacrificados nestes momentos. Os grupos irradiados mostraram um pico de vasos neoformados no dia 15, enquanto que o pico do GC foi no dia 21. O número de vasos no GC foi significantemente maior que GF e GU no dia 21. Com relação ao fluxo sangüíneo, os grupos irradiados mostraram um valor mais alto que o controle no dia 8, porém, sem diferenças significantes entre os grupos. Estes achados sugerem que o laser acelera a cicatrização de queimaduras, porém, sem diferenças significativas entre as doses estudadas. / Severe burn injuries cause extensive damage and are notoriously complicated by loss of body fluids, injury in the cutaneous vasculature and delayed wound healing. Low intensity laser therapy (LILT) has been studied as an alternative method since it is a non invasive treatment and is able to accelerate wound healing. The purpose of the present study was to evaluate the effects of LILT (λ = 660 nm) in burned skin with two different doses by histomorphometry and laser Doppler flowmetry. Thirdy six male adult Wistar rats with two burns created on the back using water vapor were divided into 3 groups. In the fractioned dose laser group (GF), the lesions were irradiated with 1 J/cm2 on days 1, 3, 8 and 10; in the single dose laser group (GU), the lesions were irradiated with 4 J/cm2 on day 1. On control group (GC) lesions were not irradiated. The blood flow was measured on days 1, 3, 8, 10, 15 and 21 and three animals per group were sacrificed in these moments. Irradiated groups showed a peak of new blood vessels formation on day 15 while for GC the peak was on day 21. At this moment, the number of vessels in GC was significantly higher than GF and GS. Regarding to blood flux, irradiated groups displayed a higher value than GC on day 8, though no significant differences were observed. These findings suggest that LILT may accelerate skin repair, however, no significant differences were observed between the studied doses.
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Avaliação da fluxometria laser doppler em dentes decíduos traumatizados necrosados antes e após tratamento endodôntico / Evaluation of laser Doppler flowmetry in traumatized primary teeth with pulp necrosis before and after endodontic treatmentWeffort, Isabela Capparelli Cadioli 10 December 2007 (has links)
Estudos de diagnóstico de vitalidade pulpar em dentes decíduos traumatizados, através da Fluxometria Laser Doppler (FLD), têm utilizado dentes tratados endodonticamente, porém o diagnóstico clínico é realizado em dentes necrosados. O objetivo deste estudo foi avaliar a FLD como teste de vitalidade pulpar em incisivos superiores decíduos traumatizados necrosados, desvitalizados (DES), antes e após tratamento endodôntico. Foram analisados em 57 crianças, de 40 a 85 meses de idade, valores de fluxo de dois dentes: IC DES - I VIT - 1 incisivo central necrosado (leitura antes e após a endodontia) e 1 incisivo central ou lateral vitalizado (leitura repetida em 2 sessões); I VIT - I VIT - 2 incisivos centrais ou laterais vitalizados (leitura em sessão única). Foi utilizado o Fluxômetro Laser Doppler (Moor Instruments, moorLab, Axminster, Inglaterra), diodo laser emitindo no comprimento de onda de 780nm, banda Doppler em 15kHz, sonda MP13 posicionada na vestibular a 4mm da margem gengival e estabilizada com posicionador de silicone. Foram avaliados dois parâmetros: F(UA), valor de fluxo de um único dente em unidades arbitrárias; F(%), variação percentual entre pares de dentes de um mesmo paciente. Estes parâmetros foram aplicados nos grupos antes e após a endodontia: F(UA) antes, F(UA) após, F(%) antes e F(%) após. No parâmetro F(UA), para os 29 IC DES antes, a variação de fluxo foi de 2,3 a 11,1UA, a média foi de 5,4UA e o desvio-padrão de 2,5UA. Para os 29 I VIT antes, a variação foi de 4,2 a 16,1UA (9,6 ± 3,5UA). Na segunda sessão, para os 29 IC DES após, foi de 1,3 a 7,4UA (3,4 ± 1,6UA), e para os 29 I VIT após foi de 3,6 a 19,7UA (9,3 ± 3,6UA). Para os 62 I VIT analisados em única sessão, a variação foi de 5,0 a 16,5UA (9,3 ± 2,4UA). No parâmetro F(%), para os 29 pares de IC DES antes - I VIT antes a variação foi de 28,0 a 98,1% (57,4 ± 17,2%). Para os 29 pares de IC DES após - I VIT após, de 18,0 a 84,5% (37,9 ± 15,2%). Para os 31 pares de I VIT - I VIT, foi de 57,5 a 146,5% (99,9 ± 23,3%). A performance dos parâmetros foi estimada pela área sob a curva ROC (AUC). Para F(UA) antes, a AUC foi de 0,862, para F(%) antes, a AUC foi de 0,941, para F(UA) após, a AUC foi de 0,975. Seus desempenhos, considerando intervalo de confiança de 95%, foram considerados entre moderadamente acurados e altamente acurados. Para F(%) após, a AUC foi de 0,987, sendo seu desempenho altamente acurado. Após comparação das AUCs, somente foi observada diferença significante, p=0,002, entre F(UA) antes e F(UA) após. Os pontos de corte propostos foram baseados nos dados obtidos antes da endodontia: para F(UA), valores menores ou iguais a 6,5UA classificam os dentes como desvitalizados e para F(%), valores menores ou iguais a 66,9%. Conclui-se que F(UA) e F(%) são parâmetros capazes de diferenciar dentes decíduos necrosados de dentes vitalizados, assim como de diferenciar dentes tratados endodonticamente de dentes vitalizados. / Studies on diagnosis of dental pulp necrosis in traumatized primary teeth using laser Doppler flowmetry (LDF) evaluate teeth with endodontic treatment; however, clinical diagnosis is performed in teeth with pulp necrosis. The aim of this study was to evaluate the LDF as pulp vitality test in traumatized primary upper incisors, with pulp necrosis (DES), before and after endodontic treatment. The pulpal flux values of 57 children, aged from 40 to 85 months, were evaluated: IC DES - I VIT - 1 central incisor with pulp necrosis (readings before and after endodontic treatment) and 1 vital central or lateral incisor (readings in 2 sessions); Control group: I VIT - I VIT - 2 vital incisors (readings in 1 session). The Laser Doppler Flowmeter (Moor Instruments, moorLab, Axminster, UK) was used. It is a diode laser emitting at 780 nm and bandwidth at 15 kHz. A MP13 probe was placed on the buccal surface of the tooth, 4mm from the gingival margin using silicone splints. Two parameters were evaluated: F(AU), the flux value of each tooth in arbitrary units, and F(%), the percentage variation of the flux value between pairs of teeth in the same patient. The two parameters were used before and after endodontic treatment: F(AU) before, F(AU)after, F(%) before and F(%) after. In the 29 IC DES before, F(AU) ranged from 2.3 to 11.1AU; the mean was 5.4AU and the standard deviation was 2.5AU; in the 29 I VIT before, ranged from 4.2 to 16.1AU (9.6 ± 3.5AU); in the 29 IC DES after, the values ranged from 1.3 to 7.4AU (3.4 ± 1.6AU), and in the 29 I VIT after, from 3.6 to 19.7AU (9.3 ± 3.6AU). In the 62 I VIT analyzed in one session, the values ranged from 5.0 to 16.5AU (9.3 ± 2.4AU). In respect to F(%), in the 29 pairs of IC DES before - I VIT before, the values ranged from 28.0 to 98.1% (57.4 ± 17.2%); in the 29 pairs of IC DES after - I VIT after, from 18.0 to 84.5% (37.9 ± 15.2%); in the 31 pairs of I VIT - I VIT, from 57.5 to 146.5% (99.9 ± 23.3%). The performance of both tests was estimated by the area under the ROC curve (AUC). Regarding F(AU) before, the AUC was 0.862; in F(%) before, the AUC was 0.941; in F(AU) after, the AUC was 0.975. The performances were classified between moderate and highly accurate (95% Confidence Interval). Regarding F(%) after, the AUC was 0.987 and its performance was highly accurate. Comparing the AUCs, there was statistical significance (p=0.002), between F(AU) before and F(AU) after. The cut-off values were based on data before endodontic treatment. The F(AU) values that were equal to or smaller than 6.5AU, and the F(%) values that were equal to or smaller than 66.9% classified the tooth as non-vital The two parameters studied, F(AU) and F(%), are able to distinguish non-vital primary teeth from vital teeth, and to distinguish vital teeth from teeth with endodontic treatment.
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Efeito da terapia farmacológica anti-hipertensiva sobre densidade capilar e função endotelial microcirculatória / Effect of pharmacological antihypertensive therapy on capillary density and microvascular endothelial functionSergio Emanuel Kaiser 17 April 2012 (has links)
Hipertensos têm rarefação capilar e disfunção endotelial microcirculatória, tornando-se mais vulneráveis a lesões em órgãos-alvo. O estudo buscou avaliar o efeito de seis meses de tratamento farmacológico sobre densidade capilar e reatividade microvascular a estímulos fisiológicos e farmacológicos em hipertensos de baixo risco cardiovascular. Secundariamente testou-se a existência de diversidade nas respostas a diferentes estratégias anti-hipertensivas. Foram recrutados 44 pacientes, com 46,71,3 anos e 20 normotensos com 48,01,6 anos. Avaliaram-se dados antropométricos e laboratoriais e dosaram-se no soro o fator de crescimento vascular endotelial (VEGF), receptor Flt-1 para VEGF e óxido nítrico (NO). A contagem capilar foi por microscopia intravital, captando-se imagens da microcirculação no dorso da falange do dedo médio e contando os capilares com programa específico. Repetia-se o procedimento após hiperemia reativa pós-oclusiva (HRPO) para avaliar o recrutamento capilar. A reatividade vascular foi testada por fluxometria Laser Doppler, iontoforese de acetilcolina (Ach), HRPO e hiperemia térmica local (HTL). Os pacientes foram distribuídos aleatoriamente para dois grupos de tratamento: succinato de metoprolol titulado a 100 mg diários ou olmesartana medoxomila titulada a 40 mg diários, empregando-se, se necessário, a hidroclorotiazida. Os controles seguiram o mesmo protocolo inicial e após seis meses todos os testes foram repetidos nos hipertensos. As variáveis clínicas e laboratoriais basais eram semelhantes em comparação aos controles e entre os dois grupos de tratamento. Após seis meses, havia pequenas diferenças entre os grupos na relação cintura-quadril e HDL. A densidade capilar antes do tratamento era significativamente menor que no grupo controle (71,31,5 vs 80,61,8 cap/mm2 p<0,001 e HRPO 71,71,5 vs 79,52,6 cap/mm2 p<0,05) e, com o tratamento, aumentou para 75,41,1 cap/mm2 (p<0,01) no estado basal e para 76,81,1 cap/mm2 à HRPO (p<0,05). À reatividade vascular, a condutância vascular cutânea (CVC) em unidades de perfusão (UP)/mmHg era similar à HTL nos controles e hipertensos e aumentou com o tratamento nos dois subgrupos (metoprolol:1,730,2 a 1,900,2 p<0,001 e olmesartana:1,490,1 a 1,870,1 p<0,001). A CVC máxima à HRPO era menor nos hipertensos: 0,30(0,22-0,39) que nos controles: 0,39(0,31-0,49) com p<0,001. Após tratamento, aumentou para 0,41(0,29-0,51) com p<0,001. O aumento foi significativo apenas no grupo olmesartana (0,290,02 a 0,420,04 p<0,001). A diferença entre o tempo para atingir o fluxo máximo à HRPO aumentou no grupo metoprolol após tratamento 3,0 (-0,3 a 8,8) segundos versus olmesartana 0,4 (-2,1 a 2,4) segundos p<0,001. À iontoforese, a área sob a curva de fluxo (AUC) era similar nos grupos e aumentou com o tratamento, de 6087(3857-9137) para 7296(5577-10921) UP/s p=0,04. O VEGF e receptor não diferiam dos controles nem sofreram variações. A concentração de NO era maior nos hipertensos que nos controles: 64,9 (46,8-117,6) vs 50,7 (42-57,5) M/dl p=0,02 e não variou com tratamento. Em conclusão, hipertensos de baixo risco têm menor densidade e menor recrutamento capilar e ambos aumentam com tratamento. Apresentam também disfunção endotelial microcirculatória que melhora com a terapia. / Capillary rarefaction and microcirculatory endothelial dysfunction are hallmarks of hypertension, rendering patients vulnerable to target organ lesions. The study aimed at assessing the effect of a six-month treatment period upon capillary density and microvascular reactivity to physiological and pharmacological stimuli. In addition, two different treatment strategies were tested for possible differences between effects upon those variables. A total of 44 patients were recruited, mean age 46.71.3 years and 20 normotensive individuals served as controls, mean age 48.01.6 years. Anthropometrical and laboratory data were collected, as well as plasma levels of vascular endothelial growth factor (VEGF), its receptor Flt-1 and nitric oxide (NO). Capillary density was obtained by intra-vital microscopy of the dorsum of the middle phalanx before and after post-occlusive reactive hyperemia (PORH). Capillary loops were counted by a semi-automated software. Microvascular reactivity was tested by laser Doppler flowmetry (LDF), and the challenges consisted of acetylcholine iontophoresis, local thermal hyperemia (LTH) and PORH. Patients were randomly allocated to either one of two treatment arms: metoprolol succinate uptitrated to 100 mg daily or olmesartan medoxomil uptitrated to 40 mg daily, with addition of hydrochlorothiazide if necessary. Controls underwent the same initial protocol and all tests were repeated in patients after six months. Baseline clinical and laboratory parameters were similar between patients and controls and between the two treatment groups. After six months there were slight, although significant, differences between the two groups in waist/hip ratio and HDL-cholesterol. In the whole cohort, pretreatment capillary density was significantly reduced compared to controls (71.31.5 vs 80.61.8 cap/mm2 p<0.001 and PORH 71.71.5 vs 79.52.6 cap/mm2 p<0.05). After treatment it increased to 75.41.1 cap/mm2 (p<0.01) at rest and 76.81,1 cap/mm2 during PORH. During LTH, cutaneous vascular conductance (CVC) in perfusion units (PU)/ mmHg was similar in patients and controls and increased significantly in both subgroups (metoprolol: from 1.730.2 to 1.900.2 p<0,001 and olmesartan: from 1.490.1 to 1.870.1 p<0.001). Maximal CVC during PORH was reduced in hypertensive patients: 0.30 (0.22-0.39) compared to controls: 0.39(0.31-0.49) with p<0.001. After therapy it increased to 0.41(0.29-0.51) with p<0.001. The change was significant only for the olmesartan subgroup (from 0.290.02 to 0.420.04 p<0.001). After treatment, the difference in time spent to reach peak flow during PORH inreased significantly in patients taking metoprolol but not in those taking olmesartan: -3.0 (-8.8 to 0.2) and 0.4 (-2.1 to 2.4) seconds after vs before, respectively p<0,001. Area under the Ach iontophoresis flow curve (AUC) was similar in controls and hypertensive patients, and increased after treatment, from 6087 (3857-9137) to 7296 (5577-10921) PU/s p=0.04. VEGF and Flt-1 receptor were similar among all groups and did not change with treatment. NO levels were higher in hypertensive individuals than in controls: 64.9 (46.8-117.6) vs 50.7 (42.0-57.5) M/dl p=0.02 and did not change with treatment. In conclusion, low-risk hypertensive patients show reduced capillary density/recruitment, and endothelial microvascular dysfunction. Both improve with treatment
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Análise comparativa de medidor de vazão em flare por tecnologia ótica e pitometria utilizando túnel de ventoSilva, Felipe Carvalho da 25 July 2012 (has links)
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Previous issue date: 2012-07-25 / With recent discoveries by the oil industry related to the reserves in Brazilian pre-salt, flow measurement technology is being re-evaluated in view of the large CO2 concentrations found in these reserves. A technology that has accuracy levels similar to those obtained with flow meters currently used and also measures independent characteristics to the composition and thermodynamic properties of gases is optical flow measurement velocimetry (OFM). The present work is related to experimental study, comparison of the speed readings from Pitot tube flow meters and optical velocimetry. This experimental study consists of qualifying and quantifying the velocity profiles among the possible configurations of flow in the wind tunnel, proposing methodology using flow conditioners and damping of the readings obtained with the Pitot tube, and analysis of readings taken with the optical sensor to evaluate
the device installation effects in the results. The results indicate that transit-time optical flow meters for medium to high speed levels, could provide readcohesive flow even in a misalignment of up to ± 5 °, although it appears in the
installation manual of the manufacturer guarantees of results meter when a misalignment of at most up to ±2º. Regarding the optical sensor intrusive effect in the readings simultaneous with the Pitot tube, it is perceived, in general, from approximately Re> 2,05x105, the intrusive effect of this influence is suppressed by other effects. Finally, for a proper flow study through Pitometry in order to make the comparison with the optical flow metering and achieve satisfactory results with the Pitot tube, the use of specific devices of flow conditioning and damping of the measured values had to be made / Com as recentes descobertas da indústria petrolífera brasileira,
relacionadas às reservas no pré-sal, a tecnologia de medição de vazão está sendo reavaliada, tendo em vista as grandes concentrações de CO2 encontradas nessas reservas. A tecnologia de medição de vazão por velocimetria óptica (OFM) possui níveis de precisão semelhantes aos obtidos com os medidores de vazão utilizados atualmente. Essa tecnologia possui as características de independência com relação à composição química e às propriedades termodinâmicas dos gases. O presente trabalho se dedica ao estudo experimental de comparação das leituras de velocidade entre tubo de
Pitot e medidor de vazão por velocimetria óptica. Para isso foi efetuada qualificação e quantificação dos perfis de velocidades em escoamento no túnel de vento, propondo metodologia de uso de retificadores de fluxo e
amortecimento das leituras obtidas com o tubo de Pitot, e análises de leituras realizadas com o sensor óptico visando avaliar os efeitos de instalação do dispositivo nos resultados obtidos. Os resultados indicam que medidores de vazão ópticos por tempo de trânsito, para níveis médios e altos de velocidade, podem fornecer a leitura esperada da vazão mesmo estando num desalinhamento de ±5º, apesar de constar no manual de instalação do fabricante garantia destes resultados do medidor quando num desalinhamento
de, no máximo, até ±2º. Com relação ao efeito intrusivo do sensor óptico nas leituras simultâneas com o tubo de Pitot, percebe-se, em geral, que a partir de aproximadamente Re> 2,05x105, o efeito intrusivo desta influência foi suprimido
por outros efeitos. Por fim, para uma devida caracterização do escoamento por meio de pitometria, a fim de efetuar a comparação com a medição Laser, e alcançar satisfatórios resultados com o tubo de Pitot, foi necessário fazer uso
de dispositivos específicos como retificadores de fluxo e de amortecimento (damping) dos valores medidos
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Efeitos da radiação laser em baixa intensidade na cicatrização de queimaduras de pele. Estudo Laser Doppler fluxométrico e histológico em ratos / Effects of low intensity laser radiation on burned skin healing. a laser doppler flowmetry and histological study in ratsStella Thyemi Sugayama 28 November 2006 (has links)
Queimaduras severas causam trauma às vítimas, pela perda de líquido corpóreo, injúria no sistema vascular cutâneo e demora na cicatrização das lesões. A irradiação com laser em baixa intensidade vem sendo estudada como tratamento alternativo, por ser uma terapia não-invasiva e capaz de acelerar o processo de cicatrização. O objetivo deste estudo foi avaliar os efeitos do laser de baixa potência (λ = 660 nm) em queimaduras de pele por histomorfometria e fluxometria laser Doppler utilizando duas condições de irradiação. Trinta e seis animais com duas queimaduras criadas por vapor foram divididos em três grupos: no grupo dose fracionada (GF), as lesões foram irradiadas com dose de 1 J/cm2 nos dias 1, 3, 8 e 10; no grupo dose única (GU), as lesões foram irradiadas com dose de 4 J/cm2 no dia 1. O grupo controle (GC) não foi irradiado. O fluxo sanguíneo foi monitorado nos dias 3, 8, 10, 15 e 21 e três animais por grupo foram sacrificados nestes momentos. Os grupos irradiados mostraram um pico de vasos neoformados no dia 15, enquanto que o pico do GC foi no dia 21. O número de vasos no GC foi significantemente maior que GF e GU no dia 21. Com relação ao fluxo sangüíneo, os grupos irradiados mostraram um valor mais alto que o controle no dia 8, porém, sem diferenças significantes entre os grupos. Estes achados sugerem que o laser acelera a cicatrização de queimaduras, porém, sem diferenças significativas entre as doses estudadas. / Severe burn injuries cause extensive damage and are notoriously complicated by loss of body fluids, injury in the cutaneous vasculature and delayed wound healing. Low intensity laser therapy (LILT) has been studied as an alternative method since it is a non invasive treatment and is able to accelerate wound healing. The purpose of the present study was to evaluate the effects of LILT (λ = 660 nm) in burned skin with two different doses by histomorphometry and laser Doppler flowmetry. Thirdy six male adult Wistar rats with two burns created on the back using water vapor were divided into 3 groups. In the fractioned dose laser group (GF), the lesions were irradiated with 1 J/cm2 on days 1, 3, 8 and 10; in the single dose laser group (GU), the lesions were irradiated with 4 J/cm2 on day 1. On control group (GC) lesions were not irradiated. The blood flow was measured on days 1, 3, 8, 10, 15 and 21 and three animals per group were sacrificed in these moments. Irradiated groups showed a peak of new blood vessels formation on day 15 while for GC the peak was on day 21. At this moment, the number of vessels in GC was significantly higher than GF and GS. Regarding to blood flux, irradiated groups displayed a higher value than GC on day 8, though no significant differences were observed. These findings suggest that LILT may accelerate skin repair, however, no significant differences were observed between the studied doses.
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