The study aimed to assess concentrations of heavy metals in soil samples on both sides along the three Niles (Blue, White, and Nile Rivers) Almogran area (Tuti Island) Khartoum city (the capital Sudan country) after overflow season. Concentrations Br, Cu, Ni, Pb, Co, Rb, Cr, Zn, Zr, Sr, Mn, Ti, K, Ca, Fe were determined using Xray fluorescence (XRF) techniques compatible with direct analysis s...

Covalent immobilization of redox-active dyes is an important strategy to evaluate structure-activity relationships in nanoscale electrochemistry by using optical readouts such as surface-enhanced Raman scattering (SERS). Here we investigate the role of the tether length in the SERS spectroelectrochemistry of surface-attached Nile Blue. Differential pulse voltammetry and a potential-dependent SE...

A laser-based double beam absorption detection system for aggregation immunoassays has been developed. The assay was based on the aggregation of gold nanoparticles that are coated with protein antigens in the presence of their corresponding antibodies. The aggregation of the gold nanoparticles results in an absorption change that is monitored at 635 nm using the double beam spectrometer. The no...

This study describes implementation of hydrological climate change impact assessment tool utilising a combination of statistical spatiotemporal downscaling and an operational hydrological model known as the Nile Forecasting System. A spatial rainfall generator was used to produce high-resolution (daily, 20km) gridded rainfall data required by the distributed hydrological model from monthly GCM ...

The present study aimed to test the effects of blue, green or white light on the stress response of the Nile tilapia, Oreochromis niloticus (L.). Each color was tested on two groups of isolated adult Nile tilapia (8 replicates each): one being subjected to confinement stress, and the other not (control). A different environmental color was imposed on each compartment by covering the light sourc...

The electrogenerated chemiluminescence (e.c.!.) and electrochemistry of the laser dyes, coumarin-2, coumarin-3D, rhodamine-GG (perchlorate), rhodamine-B (perchlorate), oxazine1 (perchlorate), and Nile Blue (perchlorate) were studied in acetonitrile using 0.1 M tetran-butylammonium perchlorate (TBAP) as a supporting electrolyte. Rather low intensity e.c.!. was obtained for all dyes except Nile B...

Intraduplex DNA-mediated reduction is established as a general mechanism for the reduction of distally bound stacked redox-active species covalently tethered to DNA through flexible alkane linkages. Methylene Blue (MB), Nile Blue (NB), and Anthraquinone (AQ) were covalently tethered to DNA with three different covalent linkages. Using these reporters DNA electrochemistry was shown to be both DN...

The monomer-dimer equilibrium and thermodynamic of several ionic dyes (Neutral Red, Nile Blue A, Safranine T and Thionine) has been investigated by means of spectrophotometric and chemometrics methods. The dimerization constants of these ionic dyes have been determined by studying the dependence of their absorption spectra on the temperature in the range 20-75 degrees C at concentrations of Neu...