My dissertation research focuses on the investigation of the transport and magnetic properties of transition metal and rare earth doped oxides, particularly SnO2 and HfO2 thin films. Cr- and Fe-doped SnO2 films were deposited on Al2O3 substrates by pulsed-laser deposition. Xray- diffraction patterns (XRD) show that the films have rutile structure and grow epitaxially along the (101) plane. The diffraction peaks of Cr-doped samples exhibit a systematic shift toward higher angles with increasing Cr concentration. This indicates that Cr dissolves in SnO2. On the other hand, there is no obvious shift of the diffraction peaks of the Fe-doped samples. The magnetization curves indicate that the Cr-doped SnO2 films are paramagnetic at 300 and 5 K. The Fe-doped SnO2 samples exhibit ferromagnetic behaviour at 300 and 5 K. Zero-field-cooled and field-cooled curves indicate super paramagnetic behavior above the blocking temperature of 100 K, suggesting that it is possible that there are ferromagnetic particles in the Fe-doped films. It was found that a Sn0.98Cr0.02O2 film became ferromagnetic at room temperature after annealing in H2. We have calculated the activation energy and found it decreasing with the annealing, which is explained by the increased oxygen vacancies/defects due to the H2 treatment of the films. The ferromagnetism may be associated with the presence of oxygen vacancies although AMR was not observed in the samples. Pure HfO2 and Gd-doped HfO2 thin films have been grown on different single crystal substrates by pulsed laser deposition. XRD patterns show that the pure HfO2 thin films are of single monoclinic phase. Gd-doped HfO2 films have the same XRD patterns except that their diffraction peaks have a shift toward lower angles, which indicates that Gd dissolves in HfO2. Transmission electron microscopy images show a columnar growth of the films. Very weak ferromagnetism is observed in pure and Gd-doped HfO2 films on different substrates at 300 and 5 K, which is attributed to either impure target materials or signals from the substrates. The magnetic properties do not change significantly with post deposition annealing of the HfO2 films.

In this project, the time-dependent one-dimensional heat equation with internal heating is solved using eigenfunction expansion, according to the thermoelectric boundary conditions. This derivation of the equation describing time-dependent heat flow in a thermoelectric sample or device yields a framework that scientists can use (by entering their own parameters into the equations) to predict the behavior of a system or to verify numerical calculations. Allowing scientists to predict the behavior of a system can help in decision making over whether a particular experiment is worthy of the time to construct and execute it. For experimentalists, it is valuable as a tool for comparison to validate the results of an experiment. The calculations done in this derivation can be applied to pulsed cooling systems, the analysis of Z-meter measurements, and other transient techniques that have yet to be invented. The vast majority of the calculations in this derivation were done by hand, but the parts that required numerical solutions, plotting, or powerful computation, were done using Mathematica 8. The process of filling in all the steps needed to arrive at a solution to the time-dependent heat equation for thermoelectrics yields many insights to the behavior of the various components of the system and provides a deeper understanding of such systems in general.

Le procédé industriel d’extraction d'inuline consiste en une diffusion de longue durée et à température élevée. Ce procédé induit l’extraction des sucres mais également des impuretés. Les étapes de purification de jus deviennent alors plus complexes. Pour pallier à ces problèmes, il est essentiel de réduire la température de diffusion pour limiter l’extraction des impuretés. Récemment, la technique de champs électriques pulsés (CEP) a démonté ses avantages dans le domaine sucrier et également dans d’autres applications agro-alimentaires. L’objectif de ce travail de thèse est de d’optimiser et valider la faisabilité de cette techniques dans le cas de la chicorée. Une purification par filtration dynamique est envisagée et proposée pour remplacer la purification classique. Les résultats de l’extraction montrent qu’il est possible d’intensifier l’extraction de l’inuline par application de CEP. Le prétraitement des cossettes de chicorées à 600 V/cm et 50 ms, réduit de 20°C la température de diffusion (60°C au lieu de 80°C actuellement). Une économie d’énergie importante est réalisée (gain 90 kJ/kg chicory juice). La combinaison innovante d’un prétraitement électrique et un traitement thermique (chauffage ohmique) provoque une perméabilisation importante des cellules et permet de réaliser des diffusions « à froid ». Les analyses qualitatives de jus de diffusion classique et jus CEP montrent que la pureté des extraits CEP est plus élevée (87.2% vs 86.7%). Les essais de filtration sur membrane montrent que les performances de la filtration (pureté, flux, colmatage,…) dépendent énormément de l’origine de l’extrait. Le jus CEP contient moins d’impureté que le jus thermique, est donc plus facile à filtré. Cependant, col matage de membrane restent dans les deux cas important. Un module de filtration dynamique avec disque rotatif a été utilisé pour améliorer les performances de la filtration. Ce module a permit de réduire le colmatage des membranes, améliorer la pureté des extraits et atteindre des facteurs de réduction volumique important (10). / Industrial inulin extraction requires high temperature and long duration to ensure inulin productivity. In addition complex steps are necessary to purify extracted chicory juice and to obtain inulin with desirable purity. In order to avoid the extracting of inulin at high temperature, to obtain chicory juice with better quality and to purify chicory juice with more simple operation, pulsed electric fields (PEF) and membrane filtration were applied to this study : PEF was used to intensify inulin extraction from chicory roots. By pre-treatment of chicory slices at 600 V/cm, diffusion temperature at pilot scale can be decreased to 60oC from about 80oC (industrial extraction condition) to obtain comparable juice inulin concentration. Moreover, this moderate temperature diffusion brought out interesting energy savings compared to that of conventional diffusion. For the goal of extracting inulin at “cold” condition (for example 30oC) PEF induced combined electroporation/ohmic heating pretreatment was applied for chicory tissue denaturation. Better solute extraction was observed after effective damage of chicory tissue diffusivity.Juice extracted from PEF assisted diffusion (PEF juice) was confirmed had higher inulin purity and less impurity in comparison to juice from conventional thermal diffusion process. The juice was purified by membrane filtration in order to investigate a simple chicory juice purification method. Since it contains less impurity, dead-end filtration performance of PEF juice was significantly improved, with less membrane fouling and higher inulin purity in filtrate. However, permeate flux of membrane filtration was seriously restricted by the membrane fouling. In order to improve filtration flux, rotating disk module was introduced in this study for clarification and purification of chicory juice. Elevated shear rate of rotating disk (1500–2000 rpm) could effectively control or even eliminate membrane fouling and lead to satisfying carbohydrate transmission (98%) and desirable permeate flux even at high volume reduction ratio (10). In view of energy saving, optimization of RDM assisted chicory juice filtration was carried out and yielded optimal operation conditions to maximize average flux and minimize specific energy consumption.

La thèse porte sur l'étude et la modélisation d'une colonne pulsée utilisée dans les opérations d'extraction liquide-liquide dans l'industrie nucléaire, et qui est par ailleurs également utilisée pour des opérations de précipitation oxalique en continu. La modélisation du comportement de la phase dispersée dans la colonne est entreprise dans ce manuscrit. Tout d'abord, nous avons commencé par la modélisation du champ moyen et de la turbulence de la phase continue qui est responsable du transport et de la rupture et coalescence de la phase dispersée. Le modèle développé, validé sur des mesures PIV, prédit d'une manière très satisfaisante la turbulence. Une modélisation des temps de séjour (DTS) des gouttes par une approche lagrangienne est ensuite entreprise. Cette modélisation est validée sur des mesures de DTS prises par une technique d'ombroscopie. Les résultats de modélisation sont en très bon accord avec les mesures expérimentales. Pour modéliser les distributions de tailles des gouttes (DTG) dans la colonne, nous avons utilisé les équations de bilan de population (PBE) que nous avons couplées avec le modèle de mécanique des fluides numérique (CFD). Un réacteur parfaitement agité (RPA) équipé d'une sonde optique est utilisé, dans un premier temps, pour acquérir les DTG relatives à notre système liquide-liquide. Par le biais d'une modélisation 0D dans le RPA basée sur la résolution du problème inverse, nous avons pu déterminer les noyaux de rupture et de coalescence adaptés à notre système pour les utiliser dans la PBE. Les noyaux de rupture et de coalescence ainsi identifiés ont ensuite été utilisés pour modéliser les DTG dans la colonne pulsée par un modèle couplé CFD-PBE basé sur la méthode QMOM. Enfin, une validation du modèle couplé CFD-PBE est réalisée sur des mesures de DTG dans la colonne pulsée. Les résultats obtenus reproduisent parfaitement les mesures expérimentales aussi bien d'un point de vue qualitatif que quantitatif. Le modèle validé est ensuite utilisé dans le cadre d'une étude paramétrique qui a permis de donner accès à un certain nombre d'informations utiles sur le fonctionnement du procédé / This study was dedicated to the modeling of the dispersed behavior in a pulsed column used both in liquid-liquid extraction and continuous oxalic precipitation in the nuclear industry. We have started by modeling the mean flow and turbulence of the continuous phase, which is responsible of the transport, breakup and coalescence of the droplets. The turbulence was accurately predicted by the model that we have validated on PIV type measurements. Then, we have moved to the modeling on the residence time distributing (RTD) of the dispersed phase via a lagrangian approach. The calculated RTDs were also validated using an ombroscopic technique allowing for the measurement of the RTD of the droplets in the pulsed column. The droplets size distribution (DSD) of the droplets were obtained by the mains of population balance equation modeling (PBE) coupled together with the CFD validated model. In order to choose the breakup and coalescence models relevant to our system, we have first used a stirred vessel in which we performed measurements of the DSD using a probe. These measured DSD were used to choose the breakup and coalescence models by resolving the 0d inverse problem. These models were then set in the CFD-PBE coupled model, which was resolved with the QMOM method, to simulate the DSD in the pulsed column. A validation of the CFD-PBE coupled model was also performed via DSD measurements inside the pulsed column. The simulations were found to accurately represent the experiments qualitatively and event quantitatively. Once the model was validated, it has been used to perform a parametric study that allowed us to gain understanding in the behavior of the dispersed phase in the pulsed column

ABSTRACT The focus of this work was the study possible ways to improve the efficiency of solar cells. To this end, the main aim was to investigate the deposition process of Indium Tin Oxide (ITO), Titanium Dioxide (TiO2), multi-layers ITO/TiO2 on quartz SiO2 substrates under different conditions (oxygen pressure, laser fluence and wavelength, and temperature) and later gold nanoparticles by the Reactive Pulsed Laser Ablation Deposition (RPLAD) technique. It was intended to investigate their electrical structural and optical properties under selected conditions for possible application to Dye Sensitised Solar Cells (DSSC). Under optimised conditions, maximum deposition rates of 12nm/min for ITO and 21nm/min for TiO2 thin films were achieved. Rutherford Backscattering Spectrometry (RBS) with 2MeV He+ ions was used to measure the films thickness. Uniform thicknesses over a large area were found to be about 400nm and 800nm for ITO and TiO2 films, respectively. Crystalline properties were studied via x-ray diffraction and Raman spectroscopy. X-ray Diffraction (XRD) analysis revealed that the ITO films are highly orientated nanocrystals with their a-axis normal to the glass substrate surface. The average particle size of the precipitated nanocrystals was calculated to be 10-15nm. The structure of the films was characterised via Atomic Force Microscopy (AFM) imaging of the top surface of the film. The films have a rough surface with average roughness of 26-30nm. Pores were observed with a density of 144 and 125 pores/mm2 and average size of 150 and 110nm for ITO films deposited at 200 and 400°C, respectively. TiO2 films deposited on the prepared ITO films were less crystalline. Annealing was performed at 300 and 500°C for 3 consecutive hours and the XRD results show that the transformation of TiO2 film into anatase phase was almost complete with a crystal size of ~ 6-7nm. Scanning Transmission Electron Microscopy (STEM) of the surfaces was also performed. The TiO2 films deposited onto the prepared ITO films present a relatively high pore size with an average pore diameter of ~ 40nm and excellent uniformity. It is interesting to note that the pores are randomly arranged. The random arrangement of the pores network may actually be beneficial for producing a uniform electrode. In addition, STEM cross-sectional analysis of the films showed a columnar structure but no evidence of voids in the structure. The large surface area produced suggests applications in DSSC. The electrical properties of the films were investigated and an estimation of resistivity and Hall mobility was made. Low values of resistivity and high values of mobility were observed for ITO films. The resistivity of the film increases with increasing thickness while it decreases when increasing the deposition temperature. The lowest value was found to be 1.5x10-6Ωm for ITO films deposited at 400°C. Hall mobility was found to increase with substrate temperature. In this investigation, the highest Hall mobility at room temperature was estimated to be 22.3cm2/Vs under ambient O2 pressure (PO2) of 1Pa and 52.1 and 51.3cm2/Vs for films deposited at 200 and 400°C, respectively. But the best ITO film was deposited at 200°C, since this film combines good resistivity, good Hall mobility and good transmittance. UV-VIS-IR transmission spectra were recorded on a Perkin Elmer Lambda 900. From the transmission data, the energy gap as well as the optical constant was estimated. A high transmission for ITO films in the visible (Vis) range was observed which was above 88% for films produced at room temperature and above 95% for those deposited at 200°C. The transmission for the films produced in oxygen was about 90% above 400nm, whereas it lies between 70 and 80% for films produced in rare gases. An increase in the band gap was observed by increasing the oxygen pressure and substrate temperature for ITO films. Increasing the quartz SiO2 substrate temperature from room temperature to 400 °C resulted in an increase of the transmission of TiO2 films, mostly in the Visible Near Infrared (Vis-NIR) from about 70% to 92%. After annealing at 500°C for 3 consecutive hours, the transmission of TiO2 film further sharply decreases toward shorter wavelengths. Analysis of the transmittance curve of TiO2/Au shows a decrease of about 6% of the transmission in the Ultraviolet Visible (UV-Vis) range. Optical absorption edge analysis showed that the optical density could be used to detect the film growth conditions and to correlate the film structure and the absorption edge. The TiO2 films deposited present a direct band gap at 3.51eV and 3.37eV for TiO2 as deposited and after annealing, respectively, while the indirect band gap was found to be 3.55eV and 3.26eV for TiO2 films as deposited and after annealing, respectively. There was a shift of about 0.1eV between as deposited ITO monolayer films and ITO/TiO2 bilayers deposited at 200°C. A small shift towards shorter wavelengths has been observed for multilayer ITO/TiO2/Au. In this case, the increase of Eg was ascribed to a reduction of the oxygen vacancies with increasing substrate temperature at which the ITO film was deposited. The change in the shape of the fundamental absorption edge is considered to reflect the variation of density and the short range structural modifications undetected by structural characterisations. Enlargement of band-gap energies of semiconductors may be advantageous when used in DSSC to suppress the charge recombination between the reduced electrolytes and the photo-excited holes in the valence band of TiO2 substrates and enhance the open-circuit potential of the cell. When ITO/TiO2 bilayers were annealed before depositing Au, the gap energy remained constant.

Para o estudo usou-se uma coluna de vidro, com 2,75 m de altura e 3,7 cm de diâmetro interno, contendo 29 pratos perfurados (diâmetro dos furos, 0,3 cm e área livre de 35 %), com espaçamento de 9,35 cm. O solvente percorria a coluna no sentido ascendente e a fase contínua, no contrário. A pulsação era fornecida ao sistema líquido por uma biela ligada excentricamente a uma polia, de um lado, e a uma junta de expansão, do outro. A frequência variou de 0 a 2,8 s-1 e a amplitude, de 0,6 a 2,3 cm. Uma primeira série de ensaios foi feita com o sistema binário acetato de n-butila-água, pois, para ele, há dados disponíveis para comparação. Dos resultados obtidos, concluiu-se ser conveniente o desempenho do equipamento. Em seguida, usou-se (a) o sistema metil isobutil cetona-água para levantar curvas de inundação e retenção da fase dispersa para várias condições de operação e (b) o sistema metil isobutil cetona-fenol-água para obter dados de transporte de massa, ou seja, altura equivalente a um estágio de equilíbrio e eficiência da remoção do fenol. Os resultados foram comparados, quando possível, com outros da literatura e com correlações existentes; em alguns casos, obtiveram-se correlações próprias. Os resultados alcançados são reprodutíveis e, para propriedades físicas e geométricas semelhantes, comportam-se de modo compatível com os da literatura. O processo é razoavelmente eficiente na remoção do fenol. / The extraction of phenol from aqueous solutions using a pulsed perforated-plate column was studied. The glass column, 2.75 m high and 3.7 cm internal diameter contains 29 perforated plates (0.3 cm holes and 35% of free area). The solvent flows upwards and the continuous phase, downwards. The pulsation was obtained by the expansion and compression of an expansion joint. Frequency varied from 0 to 2.8 s-1 and amplitude, from 0.6 to 2.3 cm. The initial tests were undertaken with the binary system n-butyl acetate-water because, for this system, there are data for comparison. It was shown that the equipment leads to convenient results. Then, the system methylisobutylketone-water was used to obtain flooding curves and dispersed phase hold-up and the system MIBK-phenol-water to study height equivalent to a theoretical stage and the phenol separation efficiency. The results were compared, whenever possible, with data from the literature and with existing correlations; specific correlations were obtained in certain cases. Results are reproducible and, for similar geometries and physical properties they are compatible with those of literature. The equipment is rather efficient in removing the phenol from the solution.

Estudo dos efeitos da irradiação ultra-sônica pulsada de baixa intensidade sobre o desenvolvimento de segmentos da coluna vertebral implantados em camundongos isogênicos / The aim of the present research was evaluate the action of low-intensity pulsed ultrasonic irradiation on development and ossification of vertebral column blastemas, through mice new born tail segments implants in adult receptor isogenic mice lineages C57BL/6 and Balb/C. New born tail segments were implanted in subcutaneous tissues of adults isogenics mice C57BL/6 and intramuscularly in adults isogenics mice Balb/C. After 24 hours the implant, the animals in both groups, were stimulated with the low-intensity pulsed ultrasound (LIPUS), 10 minutes per day. After 5 days of stimulus, the receptors animals were death and had the implanted tails removed for histopathology, trhrough Periodic Acid Schiff plus Alcian Blue (PAS/AB), Masson's tricomico and hem lumen-eosin (HE). The group of animals stimulated which received subcutaneous implant presented the implant with accelerated in inter-vertebral diks, faces to chondrocytes organization and chondroblastes findings in cartilaginous matrix, showing maturity in fiber cartilages arrangements. It was observed too, a collagen fibers enlargement in the disks fibro cartilage which show more dense next the pulposo nucleus in the segments implanted and stimulated, compared with the controls segments. The areas of the segments were available by Fisher's test and Student's t. It didn't watch significant differences in the vertebral bodies' areas sizes in the animals which implant was subcutaneous (p'< OU = '0.05). In the intramuscular implants animals group, it was observed a major velocity in the hialuronic acid matrix formation in the intervertebral disks after LIPUS stimulus. Moreover, the fibrous ring fiber cartilages' were better organized with large number of cells inside the cartilaginous matrix compared with the controls segments. With regard to the vertebral bodies in the intramuscular implants, it's not verifies significant increases in the areas (p'< OU =' 0,05). The findings allow conclude that LIPUS should promote the ontogenetic differentation of the structural components of the mice vertebral column more quickly, trhough vertebras endochondral ossification microscopic evaluation and the inter-vertebral disks components differentiation, follow the methodology employed.

A velocidade de arrastamento de elétrons caracteriza a condutividade elétrica de um gás fracamente ionizado e é um dos mais importantes parâmetros de transporte para a simulação e modelagem de detectores de radiação e de descargas em plasmas. Neste trabalho são apresentados os resultados de velocidade de arrastamento de elétrons, em função do campo elétrico reduzido, obtidos para o nitrogênio e isobutano pela técnica de Townsend pulsada. Em uma câmara de geometria planar, os elétrons primários foram liberados de um catodo de alumínio devido à incidência de um feixe de laser de nitrogênio e acelerados em direção ao anodo (placa de vidro de elevada resistividade) por meio de um campo elétrico uniforme. Os rápidos sinais elétricos (da ordem de nanossegundos) gerados foram digitalizados em um osciloscópio de 1 GHz de largura de banda para medidas do tempo de trânsito dos elétrons e cálculo das velocidades de arrastamento em diferentes distâncias entre anodo e catodo. Para validar este método, as medidas foram feitas inicialmente no nitrogênio puro em uma região de campo elétrico reduzido de 148 a 194 Td. Os resultados mostraram um excelente acordo com aqueles encontrados na literatura para este gás, amplamente investigado. As medidas de velocidade de deriva de elétrons no isobutano puro foram realizadas em função do campo elétrico reduzido de 190 a 211 Td. Os resultados concordaram dentro dos erros experimentais com os valores simulados com o programa Imonte (versão 4.5) e com os resultados recentemente obtidos pelo nosso grupo no intervalo de campo elétrico reduzido investigado neste trabalho. / The electron drift velocity characterizes the electric conductivity of weakly ionized gases and is one of the most important transport parameters for simulation and modelling of radiation detectors and plasma discharges. This work presents the results of electron drift velocity as a function of the reduced electric field obtained in pure nitrogen and pure isobutane by the Pulsed Townsend technique. In a planar geometry chamber, primary electrons were liberated from an aluminum cathode due to the incidence of a nitrogen laser beam and accelerated toward the anode (high resistivity glass plate) by an uniform electric field. The fast electric signals generated were digitalized in a 1 GHz bandwidth oscilloscope to measure the electrons transit time and to calculate the electron drift velocity in different gaps between anode and cathode. To validate this method, measurements were initially carried out in pure nitrogen, in reduced electric fields ranging from 148 to 194 Td. These results showed very good agreement with those found in the literature for this largely investigated gas. In the pure isobutane, measurements of electron drift velocities were performed as a function of reduced electric field from 190 to 211 Td. The results were concordant, within the experimental errors, with the values simulated by the Imonte (version 4.5) software and the data recently obtained by our group in the range of reduced electric field investigated in this work.

As qualidades biofísicas do U.S.P. levaram-nos a estimar o efeito do mesmo sobre a regeneração de um nervo periférico. Este estudo foi levado a efeito sobre a axotomia experimental do nervo ciático de ratos. Para tal finalidade estimulamos por 12 dias consecutivos, durante 20 minutos o coto proximal dos nervos axotomizados. A morfologia foi avaliada comparativamente entre cortes semifinos corados pelo azul de toluidina e cortes ultra finos à microscopia eletrônica, dos cotos proximais de nervos estimulados e não estimulados. A avaliação morfométrica das estruturas, baseou-se na contagem diferencial das fibras; da espessura da bainha de mielina e da área dos axônios das fibras tipo A, mediante o emprego de um software especializado ( Image Tool). Os achados morfológicos e a análise estatística dos dados morfométricos são altamente sugestivos de que o U.S.P. estimula a regeneração de nervos periféricos. / The biophysical qualities of pulsed ultrasound led us to appraise it¢s effect on the regeneration of a peripheral nerve. In this study our intention was to evaluate the effects of pulsed ultrasound on the axotomy of the ciatic nerve in rats. The proximal stump of the nerve was stimulated on 12 consecutive days with pulsed ultrasound and the effects of the sonication were evaluated through morphologic and morphometric techniques. Our findings suggest that sonication leads to a rapid regeneration of the nerve after axotomization. These affirmations are based on the counting of different types of fibre components in mixed nerves and the morphologic recovery of the same in comparasion with nerves of animals submitted to sham operation.

O objetivo do presente estudo foi avaliar os fluxos das valvas aórtica (AO) e pulmonar (Pul) por meio de análise qualitativa (presença de regurgitações valvares e características do espectro avaliado) e quantitativa, com obtenção de parâmetros ecocardiográficos como velocidades máxima (V. Max.) e média (V. Me.), integral de velocidade (VTI), tempo de aceleração (TA) e ejeção (TE), volume sistólico (VS) e débito cardíaco (DC). Foram utilizados 30 cães, que após considerados clinicamente sadios por meio de exames físico, laboratoriais, eletrocardiográfico, ecocardiográfico (modos uni e bidimensional), radiográfico de tórax e mensuração da pressão arterial sistêmica, obtiveram-se os seguintes resultados para os referidos parâmetros: V.max. AO= 1,215 + 19,38 m/s; V. Me. AO= 0,722 + 0,08206 m/s; VTI AO= 0,141 + 0,02426m; TA AO= 38,80 + 11,29 ms; TE AO= 197,9 + 24,77 ms; VS AO= 29,63 + 14,59 mL; DC AO= 2,940 + 1,260 L/ min.; V. Max. Pul= 0,9457 + 0,1792 m/s; V. Me. Pul= 0,632 + 0,09960 m/s; VTI Pul= 0,1267 + 0,02324 m; TA Pul= 70,97 + 18,87 ms; TE Pul= 203,7 + 28,98 ms; VS Pul= 28,52 + 17,96 mL; DC Pul= 3,056 + 1,546 L/ min.. Em apenas três animais observou-se regurgitação pulmonar. Alguns parâmetros tiveram correlação negativa com a variável freqüência cardíaca (VTI AO, TE AO, VTI Pul, TA Pul, TE Pul, VS Pul), outros correlação positiva com a variável peso (VTI AO, TA AO, TE AO, VS AO, DC AO, VTI Pul, TE Pul, VS Pul, DC Pul), não sendo encontrada influência da variável sexo na maioria dos parâmetros avaliados. Na comparação entre os dois fluxos, observaram-se V. Max. AO e V. Me. AO maiores que V. Max. Pul. e V. Me. Pul., respectivamente, VTI AO maior que VTI Pul, e TA AO menor que TA Pul. Observada ainda uma correlação positiva e significativa entre VS AO e VS Pul e entre DC AO e DC Pul. / The purpose of this study was the evaluation of aortic (AO) and pulmonary (Pul) valves flow for the qualitative (valvar insufficiency presence, characteristic of flow profile) and quantitative analysis, obtaining this way chocardiographic parameters as: peak (PV) and mean (MV) velocities, velocity-time integral (VTI), acceleration (AT) and ejection (ET) time, stroke volume (SV) and cardiac output (CO). Thirty dogs were studied, and to be considered normal, physical, laboratory, electrocardiographic, echocardiographic (uni and bidimensional mode) exams, torax radiographs, and measurement of the blood pressure were accomplished, and the following echocardiographic parameters were obtained: AO PV= 1,215 19,38 m/s; AO MV= 0,722 + 0,08206 m/s; AO VTI= 0,141 + 0,02426m; AO AT= 38,80 + 11,29 ms; AO ET= 197,9 + 24,77 ms; AO SV= 29,63 + 14,59 mL; AO CO= 2,940 + 1,260 L/ min.; Pul PV= 0,9457 + 0,1792 m/s; Pul MV= 0,632 + 0,09960 m/s; Pul VTI= 0,1267 + 0,02324 m; Pul AT= 70,97 + 18,87 ms; Pul ET= 203,7 + 28,98 ms; Pul SV= 28,52 + 17,96 mL; Pul CO= 3,056 + 1,546 L/ min. The variable heart rate had negative correlation with AO VTI, AO ET, Pul VTI, Pul AT, Pul ET, Pul SV, and the variable weight had positive correlation with AO VTI, AO AT, AO ET, AO SV, AO CO, Pul VTI, Pul ET, Pul SV, Pul CO, differently from the variable sex, that had no influence on the evaluated parameters. The comparation of aortic and pulmonary valves flow demonstrated AO PV and AO MV higher than Pul PV and Pul MV, respectively, AO VTI higher than Pul VTI, and Pul AT higher than AO AT. The statistical evaluation also showed a strong and positive correlation between AO SV and Pul SV and between AO CO and Pul CO.