Imidazolium Based Surface Active Ionic Liquids as Novel Micellar Media for Simultaneous and Sensitive Electrochemical Detection of Dopamine and Ascorbic Acid

Surface active ionic liquid (SAIL) micelle assisted, simultaneous and highly sensitive electrochemical sensing of dopamine (DA) and ascorbic acid (AA) is presented. Results presented herein establish that SAILs viz.1‐dodecyl‐3‐methyl imidazolium chloride ([DDMIM][Cl]), 1‐octyl‐3‐methyl imidazolium chloride ([OMIM][Cl]) and 1‐butyl‐3‐methyl imidazolium chloride ([BMIM][Cl]) exhibit a probe and SAIL nature/concentration specific impact on the redox behaviour of hydroquinone (H₂Q), dopamine (DA) and ascorbic acid (AA). To our observations, the electrochemical behaviour of DA and AA is affected oppositely by SAILs with the apparent effects being more appreciable in presence of [DDMIM][Cl]. In the presence of [DDMIM][Cl] micelles, the electro‐oxidation of AA was observed to occur at potentials about 350 mV less positive than required for electrooxidation of DA, an important advantage that minimises the interference of former in sensing of the later. The peak to peak potential separation of 350 mV observed in presence of [DDMIM][Cl] micelles is the largest to be reported so far. The DPV signal for DA and AA displayed a linear response in the concentration range of 6.6 to 99.9 μM and 6.6 to 131.5 μM respectively. Very low detection limits of 0.0161 μM for DA in presence of 39.8 μM AA and 0.0227 μM for AA in presence of 39.8 μM DA were estimated in micellar phase of [DDMIM][Cl].     

Vegetation radiative transfer modeling based on virtual flux decomposition

Many physically based approaches for modeling the scattering properties of vegetation (i.e. methods based on radiative transfer models, RTM) suffer from significant shortcomings. In particular, the energy conservation problem has remained unsolved for a long time. This is particularly evident when introducing finite size scattering elements (leaves or shoots) into equations originally describing a turbid medium. This phenomenon, called the hot spot effect, is treated in classical RTM by increasing the reflectance value at the first collision of incident photons. To overcome this shortcoming, we propose in this paper a new model called the flux decomposition model (FDM) and based on the Kallel et al. approach (AddingSD) which propose a formulation showing that the hot spot could be viewed as an increase of the posterior gap probability. The formalism is based on a decrease of the vegetation density and is called ‘the effective vegetation density’. Thus, inspired from this idea, in our study, energy conservation is achieved using the same effective density to estimate the upward diffuse flux provided by the first collision of the solar irradiance () as well as the diffuse fluxes created by scattering. Finally, to solve the RT equations, is divided into virtual subfluxes having simple expressions, allowing the division of the problem into a finite number of subproblems, each one corresponding to a given subflux easily solved based on SAIL++ formalism. Simulation tests show that the proposed model conserves energy with good accuracy. Compared to 3-D models in the ROMC/RAMI three database, our model performs similarly. Finally, compared to AddingSD, the running time is drastically reduced from about 15 min to a few milliseconds.