A Rapid and Simple Spectrophotometric Determination of Traces of Chromium (VI) in Waste Water Samples and in Soil samples by using 2-Hydroxy, 3-Methoxy Benzaldehyde Thiosemicarbazone (HMBATSC)
A rapid and simple Spectrophotmetric method has been developed for the determination of microgram amount of Chromium (VI) in aqueous dimethyl formamide (DMF). Chromium (VI) forms a yellowish green coloured M:L complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone in the acidic buffer medium (pH=6.0) at room temperature. The complex shows maximum absorption at 385nm. Beer's law is obeyed in the range 0.260 to 2.60 
Novel QSPR modeling of stability constants of metal-thiosemicarbazone complexes by hybrid multivariate technique: GA-MLR, GA-SVR and GA-ANN
Abstract The quantitative structural property relationship (QSPR) models of the logβ11 stability constants of M:L complexes of the structurally diverse thiosemicarbazones and several metal ions (M = Ag+, Cd2+, Co2+, Cu2+, Fe3+, Mn2+, Cr3+, La3+, Mg2+, Mo6+, Nd3+, Ni2+, Pb2+, Zn2+, Pr3+, Dy3+, Gd3+, Ho3+, Sm3+, Tb3+, V5+) in aqueous solution have been constructed by combining the genetic algorithm with multivariate linear regression (QSPRGA-MLR), support vector regression (QSPRGA-SVR) and artificial neural network (QSPRGA-ANN). The multi-levels optimization for grid search technique is used to find the best QSPRGA-SVR model with the optimized parameters capacity C = 1.0, Gamma, γ = 1.0 and Epsilon, e = 0.1. The quality of the QSPR models presented in statistical values as training R2 in range 0.9148–0.9815, validation Q2 in range 0.7168–0.9669 and MSE values in range 0.2742–2.4906. The new two thiosemicarbazone reagents were designed and synthesized based on the lead thiosemicarbazone reagents. The logβ11 values of new complexes Cu2+L, Ni2+L, Cd2+L and Zn2+L derived from the QSPRGA-SVR and QSPRGA-ANN model turn out to be in a good agreement with experimental data.
Remote estimation of nitrogen and chlorophyll contents in maize at leaf and canopy levels
a b s t r a c t Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl indices using near infrared (780-800 nm) and either green (540-560 nm) or red-edge (730-750 nm) spectral bands. Spectral bands that were found optimal for Chl and N estimations coincide well with the red-edge band of the MSI sensor onboard the near future Sentinel-2 satellite. The coefficient of determination for the relationships between the red-edge chlorophyll index, simulated in Sentinel-2 bands, and Chl and N content was 0.90 and 0.87, respectively.