Constantes biologiques au Congo des moutons inoculés pour préparation du vaccin antirabique

Il a été tenté d'établir les valeurs moyennes de certains constituants sanguins du matériel animal utilisé pour la préparation du vaccin antirabique. Ces valeurs sont suivies chez les animaux inoculés, et les résultats obtenus sont comparés à ceux d'autres auteurs

In situ measurement of the acoustic performance of a full scale tramway low height noise barrier prototype

International audienceThe performance of a full scale low height barrier prototype meant to attenuate tramway noise is measured in situ. The prototype is made of a simple L-shape assembly of pressed wood boards covered on the source side with fibrous absorbing material, and has been set up temporarily in a residential area in the town of Saint-Martin-d'H` eres, near Grenoble, through which a tramway line passes. A series of pass-by measurements were made at a close receiver location corresponding to the typical height of human ears, with and without the device. The tram speed has been measured as well using an auxiliary microphone located very close to the track. A significant variability in pass-by levels has been found between the different trams, even when applying an approximate correction for speed. However it is shown that the barrier provides on average an attenuation of more than 10 dB(A), during the whole pass-by. Spectral analysis of the recorded signals is carried out as well to estimate the barrier insertion loss more accurately. Furthermore, comparisons between measurements and simplistic BEM calculations show that numerical predictions can yield rather good estimates of the actual in situ performance, within a few dB(A)

Molecular nature of breakdown of the folic acid under hydrothermal treatment: a combined experimental and DFT study

Using a combination of experimental Raman, FTIR, UV–VIS absorption and emission data, together with the corresponding DFT calculations we propose the mechanism of modification of the folic acid specifically under the hydrothermal treatment at 200 °C. We established that folic acid breaks down into fragments while the pteridine moiety remains intact likely evolving into 6-formylpterin with the latter responsible for the increase in fluorescence emission at 450 nm. The results suggest that hydrothermal approach can be used for production of other purpose-engineered fluorophores

Evaluation of residence time on nitrogen oxides removal in non-thermal plasma reactor

Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore,between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode

Comparison between two carbonyl measurement methods in the atmosphere

Two atmospheric aldehyde sampling techniques, the impinger method in which aldehydes are trapped in a 2,4-dinitrophenylhydrazine acidified acetonitrile solution, and the method in which aldehydes are captured in 2,4-dinitrophenylhydrazine acidified coated cartridges commercialised by the WATERS$^{\text{\textregistered}}$, were compared for blank values, sample preservation, ozone action, and water influence. The two methods were tested in a Paris atmosphere and the influence of a KI ozone scrubber has been evaluated. Except for acetaldehyde and benzaldehyde, the two techniques do not give coherent results. When no ozone scrubber is used, the cartridge technique gives systematically lower values. Bad correlation has been obtained between data with scrubber and data without scrubber for the impinger technique except for acetaldehyde. For the cartridge technique, the correlation is better for all the aldehydes but higher values are found when a scrubber is used, except for formaldehyde. Ozone action leads to 2,4-dinitrophenylhydrazone destruction, but also to formaldehyde 2,4-dinitrophenylhydrazone formation by reaction between airborne volatile organic compounds and ozone on the cartridge surfaces