We report here the first example of an SRN1 reaction on propargylic chloride in heterocyclic series. The reaction of 4-(3-chloroprop-1-ynyl)-1,2-dimethyl-5-nitro-1H-imidazole with nitronate anions led to both the formation of the C-alkylated product through an SRN1 mechanism and the predominant ethylenic compound resulting from nitrous acid elimination on the C-alkylated product. Interestingly, in contrast to our previous works on SRN1 reactivity, no O-alkylated product was observed.
In recent international collaboration, Idaho National Laboratory (INL) and Universitä t Erlangen (UE)have developed large MIR flow systems which are ideal for joint graduate student education and research. The benefitof the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages andaround objects to be obtained without locating a disturbing transducer in the flow field and without distortion of theoptical paths. The MIR technique is not new itself others employed it earlier. The innovation of these MIR systems istheir large size relative to previous experiments, yielding improved spatial and temporal resolution. This report willdiscuss the benefits of the technique, characteristics of the systems and some examples of their applications to complexsituations. Typically their experiments have provided new fundamental understanding plus benchmark data forassessment and possible validation of computational thermal fluid dynamic codes.
We report our study on fluidization of 5000 spherical particles in a pseudo-2D gas-fluidized bed by direct numerical simulations (DNS) and experiments as well. DNS are performed using an immersed boundary method, together with the methodology developed in our earlier work for accurate prediction of gas-solid interactions at relatively low grid resolutions. Experimental measurements of solids mean motion are conducted using a combined particle image velocimetry (PIV) and digital image analysis (DIA) technique. Furthermore, the PIV technique is extended and applied for instantaneous measurements of the particle granular temperature, which is a key characteristic of particle velocity fluctuations.This paper presents a detailed direct comparison between IBM simulation results and experimental data for realistic gas fluidization, which has not been reported before in literature. The comparison reveals a good agreement with respect to the time-averaged solids motion, as well as the fluctuations of the pressure drop over the bed. The granular temperatures calculated from the simulations also agree very well with the experimental data measured by the extended PIV technique.