The importance of diagram system MnO2─NaVO3 is in obtaining a crystal phase
(chemical compounds or solid solutions). Acknowledging the fact that these compounds
have grade properties in the field of technology, it was important to study the possibi
lity of
obtaining new phases with different mole ratios, and to draw phase diagram for it,
especially the used compounds in this study have different crystal structures.
The samples were made beginning from powders of reagent grade MnO2 and NaVO3 of
5gr for each of them at following percentage mole ratios of MnO2: (10, 20, 25, 30, 33.33,
50, 66.66, 70, 71, 75, 80, 90). The mixing and grinding process was made for these
samples. Then, it made pills ellipsoidal using manually hydraulic press, and it burned into
oven at different degrees. The study was made using powder X─Rays diffraction PXRD
and different thermal analysis TG─ DTA. The results are compared with X─rays
spectrums of grade compounds and parameters of it. Then, the formation phase changes
degrees were determined. New compound was formed at ratio (MnO2)10(NaVO3)90
mole%, and crystal solid solution was formed to ratio (MnO2)25(NaVO3)75 mole%. As well
solid solution (amorphous+ new compound) was formed until mole ratio
(MnO2)75(NaVO3)25 mole%, and amorphous solid solution was formed beginning mole
ratio (MnO2)80(NaVO3)20 mole%, then the phase diagram for the studied system was
drawing.
This study has been conducted to identify the levels of heavy
metals (lead, cadmium, nickel, cobalt, copper, iron, manganese, and
zinc) in the following spices: Nutmeg, turmeric, cinnamon, ginger,
cardamom, nigella sativa, black pepper, cumin, coriander, curry,
and mixed spices.
This study was undertaken to
evaluate the chemical speciation and distribution of Mn in soils of
Homs Governorate. Sequential extraction scheme was used to
fractionate Mn into exchangeable, bound to carbonate, bound to
manganese (Mn) and iron (Fe) oxide, organically bound, and
residual forms.
Strawberry plants of Oso Grande variety has been treated with three types
of foliar fertilizers containing (Nitrogen, Boron, Manganese) individually and
combined, in addition to treating some of them using urea as soil fertilizer.
Some plants were untreated to be used as a control. Three concentrations were
used.
