Textiles, including clothing, hats, and umbrellas, offer the best way to protect against exposure to UV rays. Natural dyes are environmentally friendly dyes that reduce water pollution to a large extent compared to synthetic dyes.
The study was conducted during 2017 in the laboratories of the department of Botany
at Tishreen University, Lattakia, Syria. The effect of ultraviolet radiation (UV-C and UVB)
for different periods (0.5, 1, 3, 5, 15, 15, 30, 45, 60 minutes) on the
photosynthetic
pigments of Euglena gracilis (with three stages of measurements) was studied. The results
showed that chlorophyll pigments were more sensitive to UV-C compared to UV-B. These
reductions were correlated with the increase in the exposure time, reaching the lowest
value after 60 minutes exposure (97.83, 98.73, 99.18% for chlorophyll a, chlorophyll b and
carotenoids when measured after 24 hours respectively).
The polyethylene films protect the chlorophyll pigments against UV radiation.
The protection rate was more evident against UV-C reaching .7.7% after 24 hours in the
algae exposed for 30 minutes according to the experimental conditions.
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.
The aim of this study was evaluation the effective of chelating
solutions 17% EDTA, 0.2% Chitosan and 10% Sodium citrate by
comparing the concentrations of chelated calcium ions after
(1min-5min-24h) of application. The study was performed on 45
extracted single-rooted sound human. The sample was randomly
divided into groups (n=3), each group 15 teeth that depend on the
used solution.
The aim of the study is repairing some partially damaged
archeological wood and restoration it before being completely
damaged. For achieving this aim, the radiation technology was used in preparing some polymer blends such as Poly (vinyl alcohol)
(PVA), Poly ethylene glycol (PEG), acrylic acid (AAC), and Acryl amid (AAm) to improving adhesion forces of polymer with wood and protecting it. The results show that the best mechanical
properties was achieved by using Poly(vinyl) alcohol (PVA), acrylic
acid (AAC), and acryl amid (AAm). Also, results show that by
increasing the ratio of acrylic acid (AAC), the tensile strength,
adhesion force, hardness, transparency, are increasing. The best
tensile strength obtained was 4.79 MPa for polymer blends contains 18/% acrylic acid, 6% acryl amid, 12% poly (vinyl alcohol) when exposing to Ultra-Violet ray dose of 210 . Results, also showed that the exposing of wood to Ultra-Violet ray dose of 250 [Gry] was enough for doing sterilization, purification.
