نتایج جستجو برای: uv
تعداد نتایج: 71007 فیلتر نتایج به سال:
هدف از این مطالعه بررسی اثرات پرتو فرا بنفش روی برخی از پارامترهای فیزیولوژیکی گیاه فلفل قلمی (capsicum longum) تحت شرایط گلخانه ای می باشد. این گیاهان در شرایط یکنواخت محیطی رشد داده شدند و بعداز 35 روز تحت تیمار اشعه ی uv-a به مدت 15 روز و اشعه یuv-c به مدت 8 روز قرار گرفتند. با بررسی های انجام گرفته مشخص شد که میزان پروتئین ها تحت تأثیر اشعه ی uv قرار گرفته و در اندام های هوایی و در ریشه ان...
background: haemonchus contortus causes severe economic losses in small ru-minants, so this study was conducted to study the uv effect on h. contortus larvae and its protective effect. methods: sixteen male goats were divided into 5 groups, control infected, con-trol uninfected and uv 30minutes exposure; uv 60minutes exposure and uv booster 60minutes exposure. the uv groups were exposed to uv i...
در این پژوهش قابلیت سه فرایند اکسیداسیون پیشرفته uv/tio2، uv/h2o2 و uv/o3 در حذف رنگزای اسید قرمز 14 که یکی از پر مصرف ترین رنگزاها در صنایع نساجی است، در محیط آبی بررسی شد. در فرایند uv/tio2 بیش از 90 درصد رنگزا با غلظت 40 میلی گرم در لیتر در شرایط بهینه با ph برابر 3، در مدت زمان 30 دقیقه، توسط 4/0 گرم در لیتر دی اکسید تیتانیم و شدت تابش uv 30 وات حذف شد. همچنین در فرایند uv/o3 در شرایط بهینه...
the role of the antioxidant defense system was studied in brassica napus, and subjected todifferent supplementary bands of ultraviolet radiation (uv-a, uv-b and uv-c). this study showed thatuv-b and uv-c induced oxidative stress as evidenced by an increase in lipid peroxidation and totalascorbate content. under uv-b and uv-c treatments, flavonoids and anthocyanins were increasedsignificantly co...
Photoinhibition is light-induced inactivation of PSII, and action spectrum measurements have shown that UV light causes photoinhibition much more efficiently than visible light. In the present study, we quantified the contribution of the UV part of sunlight in photoinhibition of PSII in leaves. Greenhouse-grown pumpkin leaves were pretreated with lincomycin to block the repair of photoinhibited...
Plants use sunlight for photosynthesis and, as a consequence, are exposed to the ultraviolet (UV) radiation that is present in sunlight. UV radiation is generally divided into three classes: UV-C, UV-6, and UV-A. The UV-C region of the UV spectrum includes wavelengths below 280 nm; these highly energetic wavelengths are effectively absorbed by ozone in the stratosphere and, thus, are not presen...
Thinning of the atmospheric ozone layer leads to elevated levels of Ultraviolet-B (UVB) at the Earth's surface, resulting in an increase of health risks to living organisms due to DNA damage. This paper examines the multidecadal changes of total column ozone from 1979 to 2005 with the aid of ground-based UVB stations using the ultraviolet multifilter rotating shadow-band radiometer (UV-MFRSR). ...
Estimates of the total metal production rate (ρ̇Z) and star formation rate at z > 2 are based on Lyman break systems observed in the rest-frame ultraviolet (UV). These observations are very sensitive to dust obscuration. Here I elucidate and refine the Meurer et al. (1997) method for calculating UV obscuration, presenting new relationships which accurately model the dust reprocessing of radiatio...
UV printing is different from conventional printing in many ways. It is still ink on paper but the ink dries through a completely different process. Instead of having solvents in the ink that evaporate into the air and absorb into the paper, UV inks dry through a photomechanical process. When the inks are exposed to ultraviolet lights they turn from a liquid, or paste, to a solid. There is sign...
Ultraviolet (UV)-B irradiation leads to DNA damage, cell cycle arrest, growth inhibition, and cell death. To evaluate the UV-B stress-induced changes in plant cells, we developed a model system based on tobacco Bright Yellow-2 (BY-2) cells. Both low-dose UV-B (low UV-B: 740 J m(-2)) and high-dose UV-B (high UV-B: 2960 J m(-2)) inhibited cell proliferation and induced cell death; these effects w...
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