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.
The current research aims to study the effect of chemical disinfectants
on the roughness and hardness of the surface of the cobalt chrome
alloy, where the use of cleansing Sodium hypochlorite 5.25%
and distilled water (the control sample), Been ma
nufacturing 20
structure metal of the alloy cobalt chrome, each group containing 10
samples and was doused with samples intravenously cleared, then it
was measured surface roughness using an Atomic force microscope, and
measuring the hardness of the surface using a Vickers measuring device
hardness.
A sensitive, simple, selective spectrophotometric method has been developed for determination Cobalt (II) with 1-(2-pyridylazo)-2 naphthol (PAN). This method ralies on the formation of stable red colored complex at pH=4.1 which has an absorption maximum at 580nm.
A new carbon paste electrode (CPE) for Co2+ ion modified with
complex of Cobalt(II) with 1-(2-pyridylazo)-2-naphthol (PAN) as
electroactive 84aterial was prepared. The best performances were
obtained by carbon paste electrode with the composition Graphit
powder (47%), DOPH as plasticizer (47%) and Co-PAN as
electroactive material (6%)
Co-Cr alloys have excellent corrosion resistance, but in the
ceramic firing process, they are exposed to high temperatures that may affect the alloy corrosion causing ions' release.
We aimed to study the effect of ceramic firing on Co, Cr ions rele
ase from Co-Cr frameworks.
So, 30 Co-Cr models were fabricated and divided randomly into
two equal groups: 1st group: (control), 2nd group: exposed to ceramic firing conditions. Then samples were submerged in artificial saliva for one month, and measurements of released ions were performed using atomic absorption spectrometry.
Concentrations of both cobalt and chromium ions released in
control group (in μg/l) were less than those in 2nd group (without a
statistically significant difference).
We can consider ceramic firing as safe and acceptable process
that slightly increase Co, Cr ions release from Co-Cr frameworks.
Resonant photoemission of single crystals of the perovskite TbBaCoO3 has been carried out for freshly scraped surfaces. The resonance onset energy at the Co3p→3d threshold is used to explore the contribution of Co3d electrons to the electronic struct
ure of the valence band. The Energy Distribution Curves (EDC) corresponding to the valence band of the crystal were determined for radiation energies hv in the region of hv=60 eV. For 63.2 eV binding energy, the main contribution of Co 3d electrons was found in the main valence band peak located at 7.46 eV below the Fermi level, whereas the contribution of Tb4f electrons was found at energy 12.08 eV below the Fermi level. The results show that the density of states close to the Fermi energy is of Co3d/O2p character, with any Tb4f contribution.
The heterocyclization of unsaturated nitriles and ethyne catalyzed by
cyclopentadienyl - ١،٥ - cis, cis-cyclooctadiene-cobalt (I) and promoted by light
has been studied in toluene as solvent.
Acrylonitrile and substituted acrylonitriles gave satis
fying results
interesting for the preparation of ٢-vinylpyridines.
No reaction was observed using fumaronitrile, maleonitrile and
allycyanides.
(E)/(Z)-ratio of reactants and products seems not to be influenced within the
reaction.
