Structure and physical properties of sodium borate glasses containing nickel oxide

A series of glass samples were prepared from a mixtures of B₂O₃, Na₂O and NiO. The role of nickel oxide in a glass matrix was studied by using infrared spectra, optical absorption, magnetic susceptibility, density, and differential thermal analysis (DTA). It was shown that the addition of nickel oxide at different concentrations to the glass batches causes some deformation in the glass structure. The values of ligand field strength and Racah parameter indicated an increasing degree of covalency. The glass samples exhibited diamagnetic behaviour with NiO content up to 1 g, then paramagnetic behaviour. The densities and glass transition temperatures decreased with increase in the NiO content up to 0.2 g and then increased again. This tendency may be related to changes in the glass structure.     

Degradation of the natural mutagenic compound safrole in spices by cooking and irradiation

Safrole was determined using gas-liquid chromatography in some common spices as star anise, cumin, black pepper and ginger. Safrole concentration in these spices was 9325, 3432, 955 and 500 mg · kg^?1, respectively. Black pepper was chosen to use in the following experiments. Using Ames-test with Salmonella TA 98 and TA 100 proved high cytotoxic effects due to pure safrole and black pepper volatile oil in both of them. The degradation of safrole was obvious after drying of the washed seeds of black pepper especially at 70 °C for 30 min or with sun-drying. Also, high irradiation doses (20 and 30 kGy) caused high degradation of more than 90% of the initial toxic concentration in black pepper. Whereas, microwave caused same effects at 75 s, but unfortunately, the powder was burned due to moisture absence. Boiling whole seeds or powder of black pepper during cooking for few minutes (1-5 min) were more efficient in decreasing safrole content. Finally, these results proved that the mutagenicity of some spices due to presence of safrole can be destructed during drying of the washed seeds or during cooking either with or without any additional treatment as irradiation. But irradiation of these spices became more necessary for using in some food industries as milk products to get more safe for human consumption.     

Structure and magnetic susceptibility of irradiated sodium borate glasses containing nickel oxide

The effect of introducing soda to boric oxide on the optical absorption infrared spectra and magnetic susceptibility of sodium borate glass system containing nickel oxide was studied. It was found that increasing of Na₂O helps in forming the BO₄ group and nonbridging oxygen and the nickel ions change from the octahedral state to the tetrahedral state. The magnetic susceptibility also increases rapidly with gradual increase of soda content up to 20 mol%, and then slightly increases, this may be due to the change in the coordination number of nickel ions. Also the effect of the addition of nickel oxide was studied, it was found that the values of magnetic susceptibility increases with the gradual increase of the nickel oxide, which is due to the increase of Ni²⁺ in octahedral coordination.