La conjugaison de phase ultrasonore à couplage par l’air basée sur une céramique magnétostrictive et une membrane de filtration poreuse pour la microscopie et la vélocimétrie de micro écoulements a été développée. Dans ce but, dans le cadre de l’acoustique géométrique un système d’équations pour décrire mathématiquement le passage par l’interface entre l’élément actif du système de conjugaison de phase confocale – milieu de propagation a été développé.On a développé et réalisé une technique de codage de phase par m-séquence pour l’enregistrement des faibles signaux conjugués en phase. Cette technique a permis de travailler plus efficacement avec fort bruit et des signaux qui se trouvent sous le niveau de bruit. Aussi cette technique a permis d’améliorer une méthode de vélocimétrie des écoulements gazeux.On a développé et réalisé une technique d’adaptation d’impédance acoustique basée sur la membrane de filtration poreuse imprégnée par de l’huile. Cette technique a permis d’optimiser les conditions de transmission de l’onde à l’interface air–ferrite aux fréquences basse dans bande du MHz.Les applications possibles de l’effet de conjugaison de phase paramétrique à la vélocimétrie des écoulements gazeux et à la microscopie à couplage par l’air ont été présentées. L’application de l’effet de conjugaison de phase permet d’améliorer les performances des méthodes de vélocimétrie et de microscopie ultrasonores à couplage par l’air. Les méthodes élaborées a repoussé les limites d’applications pratiques de l’effet de conjugaison de phase et peuvent être utilisées pour le développement des dispositifs en vélocimétrie, microscopie et tomographie ultrasonore des écoulements gazeux / Air-coupled wave phase conjugation technique, based on magneto-acoustic interaction and porous membrane filters, for microscopy and velocity measurements of gas micro flows is under investigation. For this reason in the frame of ray acoustics the base system of equations for mathematical model of phase conjugate wave passage through the interface active element of con-focal WPC system – medium of propagation is developed. The phase coding technique by pseudonoise M-sequence was used for registration of weak acoustical phase conjugate signals. This method has allowed to work more effectively with strong noisy and being under noise level phase conjugate signals. Also this method has allowed improving a method of gas flow velocimetry.It is developed and realized the technology of acoustical matching on base of thin polycarbonate porous membrane filters impregnated by oil. This technology has allowed optimizing the conditions of wave transmission through the interface air–ferrite in the low megahertz frequency range.Possible applications of phase conjugate waves in air are shown. Results of investigations of air-coupled wave phase conjugation technics can serve for drawing up of new methods ultrasonic velocimetry and microscopy in technical industrial applications. The elaborated methods expand limits of application and can be used for development of devices of ultrasonic microscopy, tomography and velocimetry of gas micro flows

No controle da qualidade da água, parâmetros microbiológicos são avaliados e devem estar de acordo com os limites estipulados em portarias e resoluções. Todas as metodologias de monitoramento microbiano demandam o cultivo dos organismos-alvo. Em muitos casos, as cepas isoladas devem ser analisadas por teses fenotípicos para determinação da espécie. Por meio de inóculos de E. coli, demonstrou-se que a variação na técnica de plaqueamento se deve especialmente à falta de consistência entre as diluições. Além disso, para a análise de réplicas, comarando-se as médias de dois métodos de diluição, foi demonstrado que ser utilizado apenas uma série de diluição derivada de um único inóculo. Utilizando-se culturas puras de E. coli, E. faecalis e P. aeruginosa, a recuperação foi similar entre os meios seletivos respectivos (m-Endo, m-EI, m-PA-C) e meio não seletivo (Tripticase Soy Agar). A utilização da técnica de membrana filtrante resultou em contagens significativamente maiores para E.coli e E. faecalis em comparação ao método de spread plate. A microbiota natural presente na água potável (torneira) não influenciou significativamente as contagens de E. coli, E. faecalis e P. aeruginosa em meios seletivos. Entretanto, na água mineral engarrafada inoculada artificialmente com P. aeruginosa, a contagem foi significativamente maior na réplica estéril. Na análise de água marinha, e na réplica não estéril inoculada com E. faecalis, a contagem foi signifivativamente menor e as células de P. aeruginosa produziram colônias atípicas. Analisando-se amostras do meio ambiente (biofilmes de estação de tratamento de água, lodo de esgoto e água de córrego contaminado), 45 colônias típicas isoladas em meios de cultura seletivos foram identificadas por meio do sequenciamento do gene 16S rRNA, testes bioquímicos e MALDI-TOF. Os resultados de sequenciamento do gene 16SrRNA tiveram baixa correlação com a identificação dos organismos por testes bioquímicos (46,6% em nível de gênero e 20% em nível de espécie) e MALDI-TOF (60% em nível de gênero e 48,8% em nível de espécie). Para as cepas identificadas como E. coli e Enterococcus spp., a correlação entre o sequenciamento e MALDI-TOF foi de 75% e 62%, respectivamente. Uma vez que a quantificação de micro-organismo por membrana filtrante depende do micro-organismo em análise e do tipo de água, é necessário que os laboratórios realizem testes de padronização antes de implementar essa metodologia. Os resultados demonstram que os métodos convencionais utilizados não são adequados e suficientes para a análise da qualidade da água e, portanto, novas metodologias devem ser empregadas. Idealmente devem ser utilizadas técnicas baseadas em características fenotípicas, genômica e proteômica cujos resultados são complementares e fornecem uma identificação mais acurada. / All over the world regulatory agencies specify microbiological water quality parameters to guarantee water safety. Conventional microbiological water quality analysis is based on the cultivation of the target organisms. In many analysis protocols, phenotypic assays of isolated strains are mandated for species determination. Reference samples are required for quality assessment and quality control of analytical protocols. Using E. coli as a model organism, it was demonstrated here that the variability of plate counts of reference cultures is caused mainly by the spread of counts in individual serial dilutions. Besides, comparing the means obtained by two dilution approaches, it was demonstrated that in the analysis of replicates it is possible to use only a set of dilutions derived for a unique inoculum. Recovery of pure cultures of E. coli, E. faecalis and P. aeruginosa was similar on selective culture media (m-Endo, m-EI, m-PA-C) and with the non-selective medium (Tripticase Soy Agar). The membrane filter technique yielded significantly higher counts for E.coli and E. faecalis in comparison to spread plate method. The autochthonous microbiota of potable water (tap water) did not influence the counts of E. coli, E. faecalis and P. aeruginosa on selective culture media. However, the sterile replica of mineral water spiked with P. aeruginosa showed higher counts for these bacteria. For marine water analysis, the non-sterile replica spiked with E. faecalis yielded low counts and P. aeruginosa produced an atypical colony. Both, sample-induced variation in target strain recovery and colony appearance on culture plates indicates the requirement for method evaluation tests on particular sample matrices before implementing routine microbiological analysis by culture-based methods in the laboratory. 45 typical colonies obtained from environmental samples in selective culture media (biofilms from activated sludge, drinking water treatment plants and water from creek contaminated with raw sewage) were analyzed by 16S rRNA gene sequencing, biochemical phenotypic assays and MALDI-TOF. Sequencing showed low correlation with phenotypic assays (46,6% at the genus level and 20% at the species level) and MALDI-TOF (60% at the genus level and 48,8% at the species level). On the other hand, the strains identified as E. coli an Enterococcus spp. by 16S rDNA gene sequencing demonstrated a high correlation with MALDI-TOF (75% and 62%, respectively). Since the results showed that conventional methods aren´t suitable and sufficient to assess water quality, new technologies should be employed. Ideally, techniques should be based on phenotypic, genomic and proteomic features since the results are complementary and provide a more accurate identification.