a new method for the separation and preconcentration of trace amounts of cadmium in food and water samples by magnetic solid phase extraction (mspe) with fe3o4 magnetic nanoparticles (fe3o4-mnps) and its determination by flame atomic absorption spectrometry has been developed. for this purpose, fe3o4-mnps were synthesized via chemical precipitation method. the extraction of cadmium ions from th...

background and objectives: the addition of plasticizers (mainly phthalates and adipates) makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. the most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (dehp) though being suspected to have carcinogenic and estrogenic properties. the aim of this study is application of magn...

a novel, magnetic silica sorbent with polyelectrolyte multilayers (pems) on its surface was prepared, and was used for magnetic solid phase extraction (mspe) of trace a+ via flame atomic absorption spectrometry (faas). the experimental parameters for the mspe procedure, such as the ph, type, and concentration of eluent, ultrasonic time and effects of co-existing ions were investigated. the dete...

In this work, the stencil adaptive method is applied to investigate the effects of a magnetic field on mixed convection of Al2O3-water nanofluid in a square lid-driven cavity. The incompressible Navier-Stokes equations are solved by an adaptive mesh method which has superior numerical advantages compared to the traditional method on the uniform fine grid. The main objective of this study is to ...

A soft-sphere discrete particle model was used to simulate mixing behavior of solid substrate particles in a slow rotating drum for solid-state fermentation. In this approach, forces acting on and subsequent motion of individual particles can be predicted. The (2D) simulations are qualitatively and quantitatively validated by mixing experiments using video and image analysis techniques. It was ...

A mixed-metal metal-organic framework, (Al,Ga)-MIL-53, synthesised by post-synthetic ion exchange has been investigated using solid-state nuclear magnetic resonance (NMR) spectroscopy, microscopy and energy dispersive X-ray (EDX) spectroscopy. 17O enrichment during...

Solid-state 13C nuclear magnetic resonance was used to characterize the molecular ordering of cellulose in a cell-wall preparation containing mostly primary walls obtained from the leaves of Arabidopsis thaliana. Proton and 13C spin relaxation time constants showed that the cellulose was in a crystalline rather than a paracrystalline state or amorphous state. Cellulose chains were distributed b...