Due to the absence of operational requirements and its unidentified solutions ,this
study presented definition alternative analytical and technical conditions for the
continuation of nitrate-selective electrode working. Many electrolytes were teste
d
(ammonium sulfate, ammonium acetate and ammonium chloride). The technical and
analytical conditions shows that the best response which give the Nernst slope of the
electrode had been obtained by adding 0.5ml of ammonium sulfate (3mol / l), and the
response time was 20sec, by the time that values stabilized for 15sec. The study of pH
effect on the electrode response also showed that electrode works within the range (2-8) of
pH and that the best response was at pH = 5.5 by using acetic acid-sodium acetate buffer.
The effect of temperature on the potential electrode was studied ,it showed that the Nernest
electrode response realized within the range (18-37) C0of temperature.While Studying the
effect of some interfering ions such as (OH-, HCO3
-, CO3
2-,Cl-,NO2
-) on the work of the
electrode showed low values of the coefficient of selectivity, which did not exceed 3×10-2
that the electrode was not affected by the presence of these ions. The chosen conditions
were experimented on standard solutions, which showed that the electrode is working
within the range (10-4-10-1) mol / l of concentrations. When the concentrations was about
10-5mol/l or less than that, it was necessary to soak the electrode in solution which has low
concentration for at least one hour, and diluted the taken volumes ten times . These
technical and analytical conditions was applied on standard solutions and environmental
samples(water), which showed the accuracy ,correctly and authenticity of the
measurements.
In this study we used electro spinning technology to obtain
nonwoven webs of Nano fibers of poly vinyl alcohol and Nano
particles of silver . we dissolve the polymer poly vinyl alcohol in
it's solvent (water) to form a polymeric solution that we c
harged it
by positive charge and ejected it to leaving it on a collector that
we charged it by negative charge and used a high voltage. and
we mixed the polymer poly vinyl alcohol with silver nitrate with
different concentrations and electro spinning the mixture to obtain
Nano fibers and Nano particles of silver then we applied heat
treatment for the whole samples at 155°c for 5 minutes for tow
aims the first one is to make crosslinking between series of PVA
and the second is for the stability of silver nanoparticles , finally
we analyze samples on Scanning Electron Microscopy SEM .
Alsin Spring is the most important water sources in Syrian coastal area, due to it is the source of drinking water for the main cities and towns in the Syrian coast. This research aimed to study some contaminant indicators in Alsin spring and some t
aps of distribution system of Alsin drinking water, and compare the Indicators with samples of bottled drinking water from Alsin spring and three other water sources (Drekish, Bukkeen, and Alfigeh). The study included determining the concentrations of nitrates, nitrites and some heavy metals including lead, cadmium and nickel in water samples. The results showed that all water sources contain varying concentrations of lead, while the nickel and cadmium were vary in drinking water samples; The concentrations of nickel and cadmium in some samples were low while were under the detection limits in other samples. The analysis of samples of bottled drinking water showed that the samples from Alfigeh spring were the lesser contamination with heavy metals, while the samples from Alsin spring were contain highest concentrations of lead and nickel. The samples of bottled water from Bukkeen spring contain the highest level of cadmium. The results showed that the concentrations of nitrate, nitrite and heavy metals differ depending on the water source. However, all these concentrations were lower and within the acceptable limits of Syrian standard for drinking water. The study concluded that water resources in the coastal area are distinguished with their higher pure.
This research has included quarterly and periodically physical and chemical analysis of treatment wastewater in the Latakia countryside during year 2011 by testing three treatment plants similar in the mechanism of action and distributed in three v
illages (Happit, Al-Harah, Marg Moairban).
This study has included the measurement of temperature, pH, dissolved oxygen, turbidity, and determination of nitrate, phosphate, sulfate, and chloride.
In this research, potentiometric using Selective Electrodes ISEs, the Visible Spectrum, and the Turbidimetry methods were used.
The results showed significant differences in concentrations of the studied ions between one station to another. The highest nitrate concentrations (228.33mg/l) were recorded in Happit treatment plant especially in summer, and the highest phosphate concentrations (41.81mg/l) were in Happit treatment plant in summer. Whilst the highest sulfate concentrations which ranged between (508.67– 1157.33)mg/l were in Al-Harah treatment plant at all seasons. The highest chloride concentrations (310.33mg/l) recorded in Happit treatment plant in summer.
The statistical study has demonstrated and showed high and sometimes low correlation coefficient R2 so that gives clear indications about the sources of pollution.
This study was carried out on 90 broiler chicks which divided into three groups. The first group has been given 0.75 g/L potassium nitrate and the second group was given 1 g/L potassium nitrate with drinking water for 30 days, While the third group w
as regarded as a control.
The birds were reared in same keeping house and feeded with the same ration without any additives and no vaccinations were applied.
All birds were sacrificed and examined by naked eye. Then the thymus gland was fixed by formalin and stained microscopic sections were examined by microscope.
The histological changes in the birds which dosed by 1 g/L and 0.75 g/L of nitrate were similar and the observed changes were the small size of cortex in some lobules, and the cortex were separated from bulb with increase the number of Hassall bodies in the bulb region, also there were vacuoles and reticular cells in different stages of degeneration and edema in the connective tissues in comparison with control group.
These results confirmed that nitrate had toxic effects on the tissues of thymus, and as a sequence reduced the number of T cells which lead to decrease the resistance and Immune response of the birds and retarded the growth rate.
