Molecular Tagging Velocimetry (MTV) and Its Automotive Applications

This work provides an overview of the technique of Molecular Tagging Ve-locimetry (MTV) and some of its automotive applications. The various ele-ments of MTV implementation are briefly described in terms of the available molecular tracers, methods of tagging, detection, and processing schemes. The automotive applications of this velocimetry technique are demonstrated in mapping the velocity field of the intake flow into a “steady flow rig ” model of an internal combustion engine and flow mapping of cycle-to-cycle variation in late compression of a motored IC engine. 1

Hydroxyl radical consumption following photolysis of vapor-phase hydrogen peroxide at 266 nm: Implications for photofragmentation laser-induced fluorescence measurements of hydrogen peroxide

The decay of OH concentration following photolysis of room-temperature vapor-phase hydrogen peroxide is studied as a function of photolysis fluence at 266 nm in an open air environment. The rate of decay is found to increase with increasing photolysis fluence, i.e., with increasing number of photodissociated H2O2(g) molecules. Single-exponential functions approximate the OH concentration decay rather well, even for higher photolysis levels, and the decay time is shown to be inversely proportional to the H2O2(g) concentration. For fluences of about 450 mJ/cm(2) the difference between a single-exponential decay and measured data is becoming evident after approximately 150 mu s. Calculations based on a chemical kinetics model agree well with experimental data also for times > 150 mu s. By combining the model with measurements, the actual photolysis levels used in experiments are estimated. The best fit between measured data and the model suggests that about 1.1% of the H2O2(g) molecules are dissociated with a photolysis fluence of similar to 450 mJ/cm(2), in reasonable agreement with a Beer-Lambert based estimation. Excitation scans did not unfold any differences between OH spectra recorded at different photolysis fluences

In vitro screening of Amazonian plants for hemolytic activity and inhibition of platelet aggregation in human blood Testes in vitro de plantas Amazônicas para atividade hemolítica e inibição da agregação plaquetária em sangue humano

In the present study, different aerial parts from twelve Amazonian plant species found in the National Institute for Amazon Research's (INPA's) Adolpho Ducke Forest Reserve (in Manaus, Amazonas, Brazil) were collected. Separate portions of dried, ground plant materials were extracted with water (by infusion), methanol and chloroform (by continuous liquid-solid extraction) and solvents were removed first by rotary evaporation, and finally by freeze-drying which yielded a total of seventy-one freeze-dried extracts for evaluation. These extracts were evaluated initially at concentrations of 500 and 100 µg/mL for in vitro hemolytic activity and in vitro inhibition of platelet aggregation in human blood, respectively. Sixteen extracts (23 % of all extracts tested, 42 % of all plant species), representing the following plants: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae), exhibited significant inhibitory activity towards human platelet aggregation. A group of extracts with antiplatelet aggregation activity having no in vitro hemolytic activity has therefore been identified. Three extracts (4 %), all derived from Elaeoluma nuda (Sapotaceae), exhibited hemolytic activity. None of the plant species in this study has known use in traditional medicine. So, these data serve as a baseline or minimum of antiplatelet and hemolytic activities (and potential usefulness) of non-medicinal plants from the Amazon forest. Finally, in general, these are the first data on hemolytic and inhibitory activity on platelet aggregation for the genera which these plant species represent.<br>No presente estudo, partes aéreas obtidas de doze (12) espécies vegetais da Amazônia encontradas na Reserva Florestal Adolpho Ducke (localizada na cidade de Manaus, Estado do Amazonas, Brasil) do Instituto Nacional de Pesquisas da Amazônia foram coletadas, secadas e moídas. Porções dos materiais vegetais em pó foram extraídas com água (por infusão), metanol e clorofórmio (por extração líquido-sólido contínua) e os solventes foram removidos por evaporação rotatória e finalmente liofilização, forneceram um total de setenta e one (71) extratos liofilizados. Esses extratos foram avaliados inicialmente para atividade hemolítica in vitro e atividade inibitória da agregação plaquetária em sangue humano in vitro em concentrações de 500 e 100 µg/mL, respectivamente. Dezesseis (16) extratos (23 % dos extratos testados, 42 % das espécies vegetais) representando as seguintes plantas, apresentaram inibição significativa frente a agregação de plaquetas humanas in vitro: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae). Como principal resultado, um grupo de extratos apresentando atividade inibitória da agregação plaquetária e em que não há atividade hemolítica in vitro foi identificado. Três (3) extratos (4 % do total de extratos testados), todos obtidos a partir de Elaeoluma nuda (Sapotaceae), apresentaram atividade hemolítica. Nenhuma das espécies vegetais nesse estudo tem uso medicinal conhecido. Assim, esses dados servem de linha base ou mínimas das atividades antiplaquetária e hemolítica (e utilidade potencial) de plantas da floresta Amazônica. Finalmente, em geral, esses dados são os primeiros disponíveis sobre ação hemolítica e inibição da agregação plaquetária dos gêneros representados por essas espécies de plantas