In this study, samples of cotton fabric were dyed using direct dye
by the traditional method as well as using microwave energy at
different energy levels. It was noted that the use of microwave
energy increase the dye exhaustion at the used energy
levels
compared to the traditional method, as well as improving the
fastness to washing and wet rubbing.
Young sun flower plants were exposed to ultraviolet radiation of the type UV-B (295
nm) for 3 days (2 hours per day) with or without excluding the UV-radiations using
polyethylene layers (blue and transparent) (0.5 mm thick). The amount of photosyn
thesis
pigments was measured whereby a variation in the chlorophyll contents. Chlorophyll a
(chl.a) was noticed at these rates (without covering 19.59%, transparent polyethylene
3.40%, blue polyethylene 1.66%), chlorophyll b (chl.b) at rates (7.81, 25.13, 22.79%) and
the total chlorophyll content (2.88, 21.76, 20.53%), while the amount of carotenoid
pigments has increased in the studied samples (24.45, 19.23, 17.32%). A decrease in the
rate of photosynthetic electron transport has also been noticed (88.04, 78.71, 58.81%) in
the plant samples exposed to ultraviolet radiation (on the third day) without UV excluding
and with transparent and blue polyethylene successively. All results were compared to the
sample which was not exposed to radiation.
All results indicate the negative effect of ultraviolet radiation on the chlorophyll
content and the rate of photosynthetic electron transport, therefore, on photosynthesis and
the productivity of sun flower plants. They also point out the importance of carotenoid
pigments in protecting chlorophyll pigments from the negative effects of this radiation.
Results showed the clear positive effect of polyethylene layers, specifically the blue one, in
protecting plants against this radiation.
In this study , a dyeing process of vat dyes was carried out for
cotton fabrics (100%) at an optimal conditions for material's
concentrations (sodium hydrosolphite , oxidization agent
,alkaline agent) to obtained a reference sample using for
comp
arison with another samples which dyeing at difference
concentrations of materials and different oxidization agent and
conditions of works ( work at close condition or open) , and it
was observed the decrease of fastness's values for the tester
samples against dry and wet rubbing opposite of reference
sample and that due to the difference of concentration of
reducing agent and the weakness of bonds between the dye
and textile because of the difference of oxidization conditions.
Print pastes contain thickeners ''thickening agents'' that are often
natural or synthetic polymers. The role of thickeners is
thickening of print paste and making it more viscous to avoid
lateral diffusion and improve finesse of motifs. The aim of
this
paper is to study the effect of type and concentration of
thickeners in print paste (using vat dyes and Two-stage method)
on fastness properties and color yield. Thickeners used usually, in
this method, are sodium alginate, guar gum and starch ether.
Conventional print paste recipe applied in this method give low
fastness to dry and wet rubbing when we print in dark shade. We
used only two thickeners in various concentrations, and then the
fastness to rubbing is evaluated. The viscosity of print pastes is
measured because of its effect on the penetration of the print
paste across the fabric, thus its effect on color yield.
Classified locality Yeasts have been culturing in plantology
department at the Faculty of Science-University of Damascus,
from genera of Pichia, Candida, Geotrichum, Rhodotorula, Phaffia
on solid Czhapek agar medium, and after incubated in appropr
iate
conditions their colonies showed evidence of different colors to
produce a variety of pigments. Then it cultured in liquid Czhapek
medium to increase biomass and the genera producing
endocellular pigment separated from the medium by filtration with
added ethanol on them and blasting cells by ultrasonic waves to
get a pigment, while the genera producing exocellular pigment is
separated about the liquid medium also by filtration but the solvent
was added to the medium containing the pigment.
A new polyvinylchloride membrane sensitive to Cd+2 ions basede on 1,3-diphenyl-5-P-nitrophenylformazan as ionophore has been prepared. This electrode shows a Nernestian response for cadmuim ions over a wide range ( 1.0 ×10-6 to 1.
0 ×10-1 M ) with the slope of 27.74 mv . decade-1 . the detiction limite is 7 × 10-7 M . It has a fast response time of 15 s and can be used for at least 4 mounth without any divergence in potential . the electrode can be used in the pH range from 4.0 to 9.0 . the proposed electrode shows avery good discriminating ability towards Cd+2 ion in presence of some alkali , alkaline earth , transition and heavy metal ions. It was successfully applied for the direct determination of Cd+2 in standard and real sample solutions
Five derivatives of Formazn (FM1–FM5) were prepared through reaction between
benzaldehydphenylhydrazone with five diazonium salts by a reaction ratio of 1:1 in
alkaline medium. The hydrazone was prepared through the reaction between
phenylhydrazin
e and benzaldehydeby a reaction ratio of 1:1 in a slight acidic medium.
Crystals of formazans resulting from recrystalization were formed by using different
solvents and show variation of solubility among these formazans according to the kind of
the solvent and the kind of diazonium salt used. Their purity was studied by using thin
layer chromatography. The melting point of the prepared hydrazone and the resulting
Formazan complexes were complexes with lead (II), copper(II) and cadmium were
successfully prepared and studied by using UV and IR spectroscopy. These complexes
were used as ionophors and applied as electrically active materials in the preparation of
ion-selective membranes for the mentioned metal ions.
A reactive dye was applied to woven cotton fabric then washed-off
using water and three alkaline agents (ammonium hydroxide,
sodium bicarbonate, sodium hydroxide). The aim of washing-off is
to eliminate of dyes no fixed on fabric to avoid its diss
olution
during washing what reduces fastness to washing.
The duration and temperature of wash-off were fixed, and the
concentrations of alkaline agents used were varied, and the effects
of these variables on the wash fastness of the dyeing were
determined.
There was little difference between the three alkaline agents, in
terms of the level of wash-fastness achieved. The best result was
with sodium bicarbonate and sodium hydroxide
In this work, theoretical calculation of the ground and excited state of
coumarin compounds are performed using DFT-B3LYP and CIS methods with
6-31G basis set. IR spectrum, UV/Vis spectrum, molecular orbitals and energy
gap are calculated. We use
different solvents ethanol, methanol, water,
acetonitrile (ACN), dimethyl sulfoxide (DMSO), acetone, and dichloromethane
to compare values of UV/Vis absorption spectra. Then the calculated results are
compared with the experimental values.
During the past few years attention has been drawn on chemical techniques
that could be used to discolour textile wastewaters. We have studied the
photocatalytic degradation of various dyes (Methyl orange, Azo carmine B,
Coomassie Brilliant blue G
250, Tartrazine, Calcon, Eriochrome blue SE,
Solamine Red 4BL, Bismarck brown Y(G), Methylen blue, Black 5, Red 120,
Morin) using TiO2 P25 Degussa as catalyst. All dye solutions underwent a
decolourization. The kinetics of reaction have been studied and were found to
be zero or first order with respect to the dye. It was compared with the
adsorption properties. The effect of the addition of hydrogen peroxide has been
studied. An enhancement of the rate has been observed in all cases and the
order with respect to the dye's concentration in presence of the additive seemed
not to change. It is difficult to give general view of the kinetics using these very
different dyes but the process was found to be effective for the decolourization
of textile wastewater.
