Les polymères électroactifs (PAE), sont des matériaux permettant de réaliser une conversion entre l'énergie électrique et mécanique. L'objet de ce travail est de proposer des procédés de modifications des terpolymères électrostrictifs par voies composites basés sur différentes approches dans le but d’améliorer les performances électromécaniques et de développer des applications à partir de ces matériaux modifiés. Dans un premier temps, un nano-composite à base de terpolymère et de noir de carbone a été préparé pour améliorer la permittivité diélectrique. Dans un deuxième temps, sur la base de la nature hétérogène de terpolymère semi-cristallin ainsi que du rôle important que la polarisation interfaciale joue sur la réponse diélectrique et électromécanique, une faible quantité d’agent plastifiant (bis (2-ethylhexyl) phalate (DEHP)) a été introduite dans le terpolymère électrostrictif afin de former un composite tout organique permettant l'amélioration des performances électromécaniques. Enfin, l’utilisation de ces matériaux modifiés dans deux applications spécifiques a été étudiée: La récupération de l'énergie mécanique et une pompe microfluidique sans valve. / Electroactive polymers (EAPs), which can realize the conversion between electrical and mechanical energy, have been emerging as one of the most interesting smart materials in the past two decades due to their low density, excellent mechanical properties, ease of processing, low price and potential applications in the fields of sensors, actuators, generators, biomimetic robots and so on. The object of this work is to modify electrostrictive terpolymers with different approaches to improve the electromechanical performances and to develop some applications based on modified terpolymers. Firstly, an organic/inorganic (terpolymer/carbon black) nanocomposite was prepared to improve the dielectric permittivity based on the percolation theory. Secondly, based on the heterogeneous nature of semi-crystalline terpolymer and the important role that interface polarization plays for dielectric and electromechanical response, small molecular plasticizer bis(2-ethylhexyl) phalate (DEHP) was introduced into electrostrictive terpolymer to form an all-organic polymer composite with improved electromechanical performances. Finally, two applications including mechanical energy harvesting and microfluidic pump based on DEHP modified terpolymers were investigated.

Les pathologies respiratoires obstructives de l’enfant (asthme et broncho-alvéolites) sont l’une des principales causes d’admission en réanimation pédiatrique. Depuis plusieurs années, des progrès ont été faits pour réduire l’invasivité des soins se traduisant par une réduction de la morbidité. L’objectif de ce travail de thèse est de s’appuyer sur des mécanismes physiopathologiques pour proposer des stratégies d’optimisation ventilatoire et non ventilatoire chez ces enfants. Nous avons évalué l’impact du décubitus ventral couplé à la ventilation non invasive chez les nourrissons atteints de bronchiolite grave. Le décubitus ventral permet de réduire significativement l’effort inspiratoire et d’améliorer le couplage électromécanique du diaphragme. Ensuite nous avons évalué la « neurally adjusted ventilatory assist » (NAVA) qui est un mode ventilatoire proportionnel basé sur l’activité électrique du diaphragme. Nous avons démontré que la NAVA améliorait la synchronisation patient-respirateur et réduisait le travail respiratoire en comparaison à la « nasal continuous positive airway pressure » (nCPAP). Enfin, dans la pathologie asthmatique nous avons également décrit la faisabilité du haut débit nasal dans cette population. Ces stratégies nécessitent maintenant d’être validées sur des critères cliniques et feront l’objet de deux études multicentriques randomisées / Obstructive lung disease in children (asthma and bronchiolitis) are one of the main causes of admission to pediatric intensive care units. For several years, progress has been made to reduce the invasiveness of care resulting in a decrease in associated morbidity. The main objective of the thesis was to propose new ventilatory and non-ventilatory strategies based on physiopathology to optimize the care of such children.In children with severe bronchiolitis we evaluated the impact of prone position associated with non-invasive ventilation. The prone position decreases significantly the inspiratory work of breathing and improves the neuromechanical efficiency of the diaphragm. We also evaluated the effect of neurally adjusted ventilatory assist (NAVA) that is a proportional ventilatory mode based on the electrical activity of the diaphragm. We demonstrated that NAVA improved the patient-ventilator interactions and decrease the work of breathing in comparison with nasal continuous positive airway pressure (nCPAP). We also evaluated the feasibility of high flow nasal cannula as a respiratory support in children with severe asthma attack. These strategies need now to be validated on clinical outcomes and are the subject of two ongoing multicenter randomized trials

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Made available in DSpace on 2016-06-02T20:18:20Z (GMT). No. of bitstreams: 1 4970.pdf: 2137632 bytes, checksum: 24df6302ff25ccdf968d2ef39fc8b67f (MD5) Previous issue date: 2013-03-22 / The thesis consisted of two studies described below. The study I, entitled: "The influence of body composition measured by dual-energy absorptiometry functional capacity in patients with chronic obstructive pulmonary disease", aimed to analyze the influence of body composition assessed by dual-energy x-ray absorptiometry on functional capacity in patients with chronic obstructive pulmonary disease (COPD). We Eleven male patients with COPD (COPDG), 7 presenting moderate obstruction and 4 severe, and 11 sedentary male subjects (CG) were evaluated by dual-energy x-ray absorptiometry to assess their body composition, all subjects have also performed the 6 minute walk test (6MWT) and step test (6MST) to assess their functional capacity. No significant differences were found between groups for anthropometric data such as age, weight, height and body mass index (BMI). However, the COPDG presented forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, maximal voluntary ventilation (MVV),walked distance (WD) and number of steps (NS) significantly lower than the CG (p<0,05; Student s t test). The body bone mass (BBM), BBM%, Lean Mass (LM), LM%, and right lower limb (RLL) and left lower limb (LLL) were significantly lower in the COPDG when compared with the CG, presenting statistically significant positive correlations with 6MWT on WD and 6MST on NS (p<0,05, Pearson s test). We conclude that body composition is an important prognostic factor for patients with COPD, which reinforces the importance of assessing body composition by dual-energy absorptiometry since it has demonstrated with satisfactory accuracy in clinical practice. Moreover, it is a parameter useful evaluation and reassessment in pulmonary rehabilitation programs. Following the II study entitled: "Effects of training of high and low intensity in musculature inspiratory in individuals with severe COPD and malnourished," which aimed to verify and analyze the effects of training in high and low intensity inspiratory muscles in patients with severe COPD and malnourished. We evaluated 32 men with severe COPD and malnourished, divided into two groups (G1 and G2). Assessments of the degree of dyspnea, pulmonary function test, MIP, WD, SGRQ and DM were performed at pre-training and after 12 weeks of training. We found that G1 got significant increase in MVV, MIP, WD and DM, and significant decreases in the percentages MRCm and SGRQ at 12 weeks of training, which remained after 12 weeks without training. Group 2 showed the same behavior when compared with the G1 at 12 weeks of training, but values returned to the initial MVV, MRCm, DM and MIP and WD had values below the baseline, and the percentage increased significantly SGRQ after 12 weeks without training. In the intergroup analysis (12-12 weeks) G1 showed higher values in MVV, MIP, WD and DM values and smaller percentages in the SGRQ compared with G2. Comparing the 24-24 weeks, G2 showed lower values in MVV, MIP, WD and DM and significant increases in the percentages MRCm and SGRQ compared with G1. The TMI high and low intensity promoted benefits to individuals with severe COPD and malnourished, which were maintained after 12 weeks of high intensity training. / A tese constou de dois estudos descritos a seguir. O estudo I, intitulado: A influência da composição corporal avaliada pela absorciometria duo-energética na capacidade funcional em portadores de doença pulmonar obstrutiva crônica , teve como objetivo analisar a influência da composição corporal avaliada pela absorciometria duo-energética na capacidade funcional em portadores de DPOC. Foram avaliados 11 indivíduos do sexo masculino portadores de DPOC, sendo 7 com obstrução moderada e 4 grave (Grupo DPOC - GDPOC) e 11 indivíduos sedentários do sexo masculino (Grupo Controle - GC), por meio da absorciometria duo-energética para avaliar a composição corporal, bem como pelo teste de caminhada de seis minutos (TC6) e teste do degrau (TD6) para avaliar a capacidade funcional. Não houve diferenças significantes intergrupos na idade, peso, altura e índice de massa corporal (IMC). No entanto, o GDPOC apresentou Capacidade Vital Forçada (CVF), Volume Expiratório Forçado no primeiro segundo (VEF1), relação VEF1/CVF, Ventilação Voluntária Máxima (VVM), Distância Percorrida (DP) e Número de Degraus (ND) significantemente menores que o GC (p&#61603;0,05, teste t Student). A Massa Óssea Corporal (MOC), % MOC, Massa Magra (MM), % MM e MM do Membro Inferior Direito (MID) e Membro Inferior Esquerdo (MIE) no GDPOC foram significantemente menores que no GC obtendo correlações positivas estatisticamente significantes com a DP no TC6 e ND no TD6 (p&#61603;0,05; correlação de Pearson). Concluímos que a composição corporal é um importante fator de prognóstico para pacientes com DPOC, o que reforça a importância da avaliação da composição corporal pela absorciometria duo-energética uma vez que tem demonstrado precisão satisfatória na prática clínica. Além disso, é um parâmetro de avaliação e reavaliação útil em programas de reabilitação pulmonar. Na sequência, o estudo II intitulado Efeitos do treinamento de alta e baixa intensidade na musculatura inspiratória em indivíduos com DPOC grave e desnutridos , que objetivou verificar e analisar os efeitos do treinamento de alta e baixa intensidade na musculatura inspiratória em indivíduos com DPOC grave e desnutridos. Foram avaliados 32 homens com DPOC grave e desnutridos, divididos em dois grupos (G1 e G2). As avaliações do grau de dispneia, prova de função pulmonar, PImáx, DP, SGRQ e MD foram realizadas no pré-treinamento e após 12 semanas de treinamento. Observou-se que o G1 obteve aumento significante da VVM, PImáx, DP e MD, e diminuições significantes na MRCm e das porcentagens do SGRQ em 12 semanas de treinamento, os quais se mantiveram após 12 semanas sem treinamento. O G2 apresentou o mesmo comportamento quando comparado com o G1 em 12 semanas de treinamento, porém os valores voltaram aos iniciais na VVM, MRCm, MD e as variáveis PImáx e DP apresentaram valores abaixo da avaliação inicial, e as porcentagens do SGRQ aumentaram significantemente após 12 semanas sem treinamento. Na análise intergrupo (12-12 semanas) o G1 apresentou valores maiores na VVM, PImáx, DP e MD e valores menores nas porcentagens do SGRQ quando comparado com o G2. Na comparação das 24-24 semanas, o G2 apresentou valores menores na VVM, PImáx, DP e MD e aumentos significantes na MRCm e nas porcentagens do SGRQ quando comparados com G1. O TMI de alta e baixa intensidade proporcionou efeitos benéficos aos indivíduos com DPOC grave e desnutridos, os quais se mantiveram após 12 semanas do treinamento de alta intensidade.

This research aimed at assessing respiratory muscle function, electrical activity of the accessory inspiratory muscles, diaphragmatic range of movement (DROM), the palate dimensions and nasal patency in adults with mouth breathing mode (MB), comparing with adults with nasal breathing mode (NB). In the study, 77 adults were selected, from 18 to 30 years old, of both sexes, according the inclusion criteria, allocated in MB (n=38) and NB (n=39) groups. The breathing mode (MB/NB) was diagnosed, based on physical characteristics, the signs and symptoms and on the otorhinolaryngologic examination. It was evaluated anthropometric measurements, maximal inspiratory and expiratory pressures (MIP, MEP), peak nasal inspiratory flow (PNIF), spirometry, nasal obstruction symptoms (NOSE scale), vertical and transverse palate dimensions , ultrasonography of the diaphragm muscle during breathing at Tidal Volume (TV), inspiration at Lung Total Capaciy (LTC) and sniff test. Yet, it was carried out the surface electromyographic (sEMG) of the sternocleidomastoid (SCM) and upper trapezius (UT) for evaluation of the amplitude and symmetry activity (POC%) during rest, inspiration at LTC and in the sniff, MIP and MEP tests. For statistical analysis, SPSS statistical software (version 17.0) was utilized, adopting a significance level of 5 % and the tests Shapiro-Wilk (data normality), Student t and Mann-Whitney (comparison between groups), Intraclass Correlation Coefficient (inter and intra-examiner reproducibility), Pearson and Spearman (correlation between variables) and the chi-square test for nominal variables. In the comparison between groups, the MB had significantly higher mean values for NOSE scale and lower mean values for MIP, MEP, PNIF, forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and sEMG activity of SCM in the sniff, PNIF and MIP tests. There was no difference in sEMG activity during rest, inspiration TLC, as well as for the POC%. The DROM was lower in the MB group in all tests, with significant difference at rest and TLC. Palate dimensions, in the MB group, showed significantly smaller transverse distance in intercanine region and, bigger in the vertical distance at the premolars and molars regions. The PNIF correlated inversely with the NOSE scale, with the UT sEMG at rest and LTC and, positively, with the FVC, the palate transversal distance, MIP and DROM. The MIP was positively correlated with MEP and FVC. The MB group presented smaller nasal patency, smaller width and higher height of hard palate than NB. The mouth breathing reflected in the smaller values of respiratory pressures, accessory inspiratory muscle electrical activity and diaphragmatic amplitude. As smaller the nasal patency, smaller the respiratory muscle pressure, the diaphragm amplitude and the width of hard palate. / Esta pesquisa teve por objetivo verificar a função muscular respiratória, atividade elétrica dos músculos inspiratórios acessórios, amplitude do movimento diafragmático (AMD), dimensões do palato e patência nasal em adultos com modo respiratório oral (RO), comparando-os com adultos com modo respiratório nasal (RN). Foram selecionados 77 adultos, entre 18 e 30 anos de idade, de ambos os sexos, de acordo com os critérios de inclusão, sendo alocados nos grupos RO (n=38) e RN (n=39). O modo respiratório foi diagnosticado baseado nas características físicas, sinais e sintomas e no exame otorrinolaringológico. Avaliou-se medidas antropométricas, pressões inspiratórias e expiratórias máximas (PImáx, PEmáx), pico de fluxo inspiratório nasal (PFIN), espirometria, sintomatologia de obstrução nasal (escala NOSE), dimensões vertical e transversal do palato e ultrassonografia do diafragma durante respiração em volume corrente (VC), inspiração na capacidade pulmonar total (CPT) e teste de sniff. Ainda, realizou-se eletromiografia de superfície (sEMG) dos músculos esternocleidomastoideo (ECM) e trapézio superior (TS), para avaliação da amplitude e índice de simetria da atividade elétrica (POC%) no repouso, inspiração na CPT, sniff, PImáx e PFIN. Para a análise estatística utilizou-se o programa estatístico SPSS (versão 17.0), com nível de significância de 5% e os testes Shapiro-Wilk (normalidade dos dados), t-student e Mann-Whitney (comparação entre os grupos), Coeficiente de Correlação Intraclasse (reprodutibilidade inter e intra-examinadores), Pearson e Spearman (correlação entre as variáveis) e o qui-quadrado (variáveis nominais). Na comparação entre os grupos, os RO apresentaram valores significativamente maiores para a escala NOSE e menores para PImáx, PEmáx, PFIN, capacidade vital forçada (CVF), volume expiratório forçado no primeiro segundo (VEF1) e amplitude da sEMG dos músculos ECM nos testes de sniff, PFIN e PImáx. Não houve diferença na sEMG no repouso e na inspiração em CPT, assim como no POC%. A AMD foi menor no grupo RO em todas as situações testadas, com diferença significante durante o repouso e CPT. O grupo RO apresentou distância transversal do palato significativamente menor na região intercanina e maior na distância vertical, na região dos pré-molares e molares. A medida do PFIN se correlacionou inversamente com a escala NOSE e com a sEMG do TS durante o repouso e CPT. Correlações positivas foram encontradas na medida do PFIN com CVF, distância transversal do palato, PImáx e AMD. A PImáx se correlacionou positivamente com a PEmáx e CVF. O grupo RO apresentou menor patência nasal, menor largura e maior altura do palato duro que o RN. A respiração oral repercutiu em menores valores de pressões respiratórias, de atividade elétrica dos músculos inspiratórios acessórios e de amplitude diafragmática. Quanto menor a patência nasal, menores os valores das pressões respiratórias, a amplitude de movimento do diafragma e a largura do palato duro.

Introdução: As alterações da mecânica diafragmática e a alta atividade dos músculos da caixa torácica estão associadas com maior sensação de dispnéia em pacientes com DPOC. Tem sido demonstrado que a respiração diafragmática (RD) aumenta a mobilidade abdominal durante o padrão diafragmático voluntário, porém, até o presente momento, nenhum estudo investigou as mudanças na mobilidade abdominal adotadas naturalmente. O objetivo desse estudo foi investigar os efeitos de um programa de treinamento de respiração diafragmática (PTRD) na mobilidade tóraco-abdominal, mobilidade diafragmática e capacidade funcional de pacientes com DPOC. Método: Trinta pacientes com DPOC (VEF1 42 +/- 13% do predito) foram alocados aleatoriamente para o grupo treinamento (GT) ou grupo controle (GC). O GT completou um PTRD supervisionado de 4 semanas (3 sessões semanais individualizadas). A efetividade do treinamento foi avaliada por meio da mensuração da relação da amplitude de movimento da caixa torácica pelo abdômen (CT/ABD; variável primária) e da mobilidade diafragmática (variável secundária). A relação CT/ABD foi quantificada utilizando a pletismografia respiratória por indutância durante RD voluntária e respiração natural (RN) e a mobilidade diafragmática foi determinada por avaliação ultra-sonográfica. O teste de caminhada em 6 minutos (TC6min) e os fatores de saúde relacionados à qualidade de vida (FSRQV) também foram avaliados. Resultados: Apenas os pacientes do GT apresentaram uma melhora na mobilidade diafragmática (18,8%) e uma redução na relação CT/ABD durante RN (26,1%) e RD voluntária (28,3%), sugerindo que a mobilidade abdominal aumentou em ambas as condições. Também foram observadas melhoras no TC6min e nos FSRQV no GT. Não foi observada diferença no GC para nenhuma variável mensurada. Conclusões: O PTRD para pacientes com DPOC induziu um aumento do recrutamento diafragmático durante a respiração natural resultando em melhora da capacidade funcional / Background: Impairment of diaphragm mechanics and enhanced activity of the chest wall muscles are associated with increased dyspnea in COPD patients. Diaphragmatic breathing (DB) has been suggested to improve abdominal motion but only during voluntarily DB, and no controlled studies have investigated the naturally adopted change in abdominal motion. The aim of this study was to investigate the effects of a diaphragmatic breathing training program (DBTP) on thoracoabdominal motion, diaphragmatic mobility and functional capacity in COPD patients. Methods: Thirty subjects (FEV1 42+/-13% predicted) were randomly allocated to either training (TG) or control group (CG). TG completed a 4-week supervised DBTP (3 individualized weekly sessions). Effectiveness was assessed by amplitude of the rib cage to abdominal motion ratio (RC/ABD ratio; primary outcome) and diaphragmatic mobility (secondary outcome). The RC/ABD ratio was measured using respiratory inductive plethysmography during voluntarily DB and natural breathing (NB). Diaphragmatic mobility was measured by ultrasonography. A 6-minute walk test (6MWT) and health-related quality of life (HRQoL) were also evaluated. Results: Only COPD patients from the TG demonstrated an improvement in diaphragmatic mobility (18.8%) and a reduction of the RC/ABD ratio during both NB (26.1%) and voluntarily DB (28.3%), suggesting that the abdominal motion improved in both conditions. An improvement in the 6MWT and in HRQoL was also observed in the TG. No differences were found in the CG for any measured outcome. Conclusions: We concluded that DBTP for COPD patients induced increased diaphragm recruitment during natural breathing resulting in an improvement in functional capacity

Les parois moulées sont des ouvrages de fondations en béton armé. Le béton de paroi moulée n'est jamais vibré et présente une fluidité élevée. Les observations effectuées après le terrassement et le rabotage des parois montrent que celles-ci présentent des défauts qui sont reliés au ressuage du béton lors de sa mise en place. Les cheminées de remontées d’eau représentent 90% des désordres observés sur les chantiers. Les constituants du béton sont souvent mis en cause. Une étude a été menée afin de comprendre l'influence des divers paramètres affectant le ressuage. Quatre formulations de béton issues de chantier ont été caractérisées en laboratoire. Une formule a montré sur chantier sa robustesse vis à vis du ressuage, tandis que les trois autres formulations ont abouti à des pathologies plus ou moins sévères. La formulation qui présentait le plus de pathologies a été modifiée de manière à observer l’effet des constituants de la formulation vis à vis du ressuage forcé et statique. Différentes pressions ont été étudiées afin de simuler différentes hauteurs de paroi moulée. Cette étude a permis de valider la pression 5 bars prédite par les recommandations Bauer. La formulation de base de ce béton de fondation a été modifiée de manière à obtenir une courbe granulaire continue, un rapport G/S proche de 1 et une augmentation du dosage en fines supérieur à 430 kg/m3. Les résultats des essais ont permis de limiter le seuil admissible du filtre presse Bauer à 15 ml au lieu de 24,4 ml. Les formulations du béton de fondation de plusieurs chantiers de parois moulées ont été modifiées, ce qui a permis de valider les prescriptions précédentes. Des recommandations ont pu être proposées. / The diaphragm walls are foundations made with reinforced concrete. The concrete of diaphragm wall is never vibrated and has a high fluidity. The observations recorded following excavation and planing of diaphragm walls demonstrate that defects are observed which are correlated with concrete bleeding during placement. Water upwelling pathology represents 90% of all disorders observed at project sites. Mix components are often implicated. A study was conducted to understand the influence of various parameters affecting the bleeding. Four concrete mix designs derived from the field were characterized in the laboratory. On a jobsite, one design has, revealed its robustness with respect to bleeding, whereas the other three have led to pathologies of varying severity. The tested concrete displaying the most of pathologies was modified so as to observe the effect of different mix components on the forced and static bleeding. A range of pressures was introduced as a means of simulating various diaphragm wall heights.This study validated the pressure 5 bar predicted by the Bauer recommendations. The basic formulation of this concrete of foundation has been modified in order to have a continuous granular curve, G / S close to 1 and an increasing in the dosage of fines greater thinly than 430 kg / m3. The results of tests served to limit the admissible threshold of filter press Bauer at 15 ml instead of 24,4 ml. The formulations of the concrete foundation of several diaphragm walls have been modified accordingly, which validated the previous prescriptions. Recommendations have been proposed.

Critical care has undergone several developments in the recent years leading to improved survival. However, acquired muscle weakness in the intensive care unit (ICU) is an important complication that affects severely ill patients and can prolong their ICU stay. Critical illness myopathy (CIM) is the progressive decline in the function and mass of the limb muscles in response to exposure to the ICU condition, while ventilator-induced diaphragm dysfunction (VIDD) is the time dependent decrease in the diaphragm function after the initiation of mechanical ventilation. Since the complete underlying mechanisms for CIM and VIDD are not completely understood, there is a compelling need for research on the mechanisms of CIM and VIDD to develop intervention strategies targeting these mechanisms. The aim of this thesis was to investigate the effects of several intervention strategies and rehabilitation programs on muscle wasting associated with ICU condition. Moreover, muscle specific differences in response to exposure to the ICU condition and different interventions was investigated. Hence, a rodent ICU model was used to address the mechanistic and therapeutic aspects of CIM and VIDD. The effects of heat shock protein 72 co-inducer (HSP72), BGP-15, on diaphragm and soleus for rats exposed to different durations of ICU condition was investigated. We showed that 5 and 10 days treatment with BGP-15 improved diaphragm fiber and myosin function, protected myosin from posttranslational modification, induced HSP72 and improved mitochondrial function. Moreover, BGP-15 treatment for 5 days improved soleus muscle fibers function, improved mitochondrial structure and reduced the levels of some ubiquitin ligases. In addition to BGP-15 treatment, passive mechanical loading of the limb muscles was investigated during exposure to the ICU condition. We showed that mitochondrial dynamics and mitophagy gene expression was affected by Mechanical silencing while mechanical loading counteracted these effects. Our investigation for other pathways that can be involved in muscle wasting associated with ICU condition showed that the Janus kinase 2/ Signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is differentially activated in plantaris, intercostals and diaphragm. However, further studies are required with JAK2/STAT3 inhibitors to fully examine the role of this pathway in the pathogenesis of CIM and VIDD prior to translation to clinical research.

This thesis deals with the study of parameters of diaphragm discharge in liquids. NaCl solution of different conductivity was used as a conductive medium. Conductivities were adjusted in the range from 220 to 1000 µS cm-1. Two diagnostic methods were used for the study of plasma parameters. The first one was employed in the laboratory of plasma chemistry at Faculty of Chemistry, Brno University of Technology, namely the optical emission spectroscopy. The second method used for plasma diagnostics was the time resolved ICCD camera at the Laboratoire de Physique des Plasmas at the École Polytechnique in Paris. The reactor for the diagnostics by optical emission spectroscopy had the volume of 4 l, and it was made of polycarbonate. PET diaphragm was placed in the barrier separating the cathode and the anode space. Electrodes were made of titanium coated with platinum. Electric power source supplied a constant DC voltage of maximum 5 kV and electric current up to 300 mA. Spectrometer Jobin Yvon TRIAX 550 with CCD detector was used during the experiments in order to measure overview spectra within the range from 200 to 900 nm as well as OH molecular spectra and Hß line spectra. All spectra were scanned in both discharge polarities, i.e. at the cathode and the anode part of reactor. The basic parameters of the discharge plasma were calculated from the spectra, that means rotational and electron temperature and electron density. Another part of experiment consisted of measurements by the ICCD camera iStar 734. Two types of reactors were used. The first one was the same as the reactor for the measurements by the optical emission spectroscopy. The second one was also made of polycarbonate, but the volume of conductive solution was 110 ml, only. HV electrodes made of stainless steel were placed in this reactor. Ceramic diaphragm (Shapal-MTM) was used in both reactors. Diaphragms had different thickness and diameter of holes. ICCD camera acquired photographs with details of processes of the bubbles generation and discharge operation (propagation of plasma channels), depending on solution conductivity, dimensions of the diaphragm, and with respect to the electrode part of the reactor.

This work is focused on study of electrical discharges in liquids, especially in water solutions. Generation of the discharge in water solutions leads to simultaneous effect of UV radiation, shock waves, electrical field and most importantly, chemically reactive species. This can be utilized in many applications such as sterilization, degradation of organic waste products, lithotripsy or other medical applications. The experimental part is concentrated on a diaphragm arrangement of the reaction system. This means that the reactor is divided into two electrode reservoirs connected only through a small orifice in a dielectric barrier. This barrier is made of Macor® non-porous ceramics with thickness of 1 mm, with the diameter of the orifice 0.6 mm, in the first part of work. In the second part, ShapalTM-M ceramics of thickness 1.0 mm and orifice diameter 0.6 mm was used. The experimental part is divided into two sections. For both, NaCl is chosen as an electrolyte to set the initial conductivity of the tested solutions to the value of 400 S/cm. Supplied direct voltage is regulated to attain power of 100 W in the system. In the first part, effect of addition of chosen alcohols (ethanol, isopropylalcohol and glycerol) on the efficiency of the discharge in their water solutions is studied. For this purpose, a special glass reactor was designed and constructed. The efficiency of the discharge is measured by a spectroscopic determination of concentration of complex formed by a titanium reagent and hydrogen peroxide, which is generated during the discharge. The results show no positive effect of addition of extra OH group to the reaction through the alcohols. The use of isopropylalcohol causes even a significant decrease in the amount of hydrogen peroxide generated. The subject of the second part is a comparison of effect of different electrode materials on the discharge. The efficiency is measured by the same method as in the first part. Materials chosen were stainless steel, platinum, aluminium, copper and carbon. Each material shows different hydrogen peroxide production rate under the same parameters. The most perspective material seems to be carbon, as an inert material, that can be expected not to initiate any decomposition of hydrogen peroxide. The least favourable appears to be copper. When used, no production of hydrogen peroxide was observed in one of the electrode parts of the reactor.