نتایج جستجو برای: ultraviolet a

تعداد نتایج: 13444736  

ژورنال: سلامت و محیط زیست 2021

Background and Objective: Monitoring the amount of ultraviolet radiation from sunlight can provide a basis for assessing people's exposure, raise public awareness and warn people against this radiation. Measuring the sun's ultraviolet index over a working period is an accurate choice to achieve this goal. Materials and Methods: In this study, the amount of solar UV index in one of the outdoor ...

Journal: :The Journal of investigative dermatology 2002
Dat X Nghiem Nasser Kazimi David L Mitchell Arie A Vink Honnavara N Ananthaswamy Margaret L Kripke Stephen E Ullrich

The ultraviolet radiation present in sunlight is immune suppressive. Recently we showed that solar-simulated ultraviolet radiation (ultraviolet A + B; 295-400 nm), applied after immunization, suppressed immunologic memory and the elicitation of delayed-type hypersensitivity to the common opportunistic pathogen, Candida albicans. Further, we found that wavelengths in the ultraviolet A region of ...

The present study was focused to examine the combined effects of climate and ultraviolet-B radiation on conifer tree-ring density. Statistical methods were employed to extract tree responses in annual ring density and to identify functional relationship in trees when the level of ultraviolet-B radiation changes regardless of climate variations. In this study, the consideration was given to the ...

Journal: :بهداشت و توسعه 0
روح الله مقصودی مقدم فرهاد فراستی علی طولابی زهره جعفرزاده

background: light is an important and adjustable physical factor in the job environment.this study aimed to determine the intensity of natural and mixed light and also the level of ultraviolet radiation in libraries and computer sites of ilam universities in spring 2011.   methods: in this cross-sectional study, 10 libraries, 16 study saloons, and 7 computer sites were selected. luminosity asse...

Introduction. Azithromycin is among the broad-spectrum antibiotics that is widely available in various environmental systems and could have destructive effects on the ecosystem and human health due to its bacterial resistance. In this study, removal of azithromycin from wastewater using an advanced oxidation process of ultraviolet light with and without persulfate was investigated and effective...

Ultraviolet radiation divides to three bands UV-A (320-390 nm), UV-B (280-320 nm) and UV-C (254-280 nm). Different bands of ultraviolet radiation have different effects on growth, physiological and biochemical plants. In this research the effect of different bands of UV radiation on the shoot and root length, quantity of flavonoids, anthocyanine, protein, ethylene, peroxidase and polyphenol o...

A. Alemi, M. Sertkol S. Khademinia

Lithium disilicate nano-powders were synthesized via a mild condition hydrothermal reaction at 180 ºC for 48 and 72 h with a non stoichiometric1:2 Li:Si molar ratio in NaOH aqueous solution using Li2CO3 and SiO2.H2O as raw materials. The synthesized materials were characterized by powder X-ray diffraction (PXRD) technique and Fourier transform infrared (FTIR) spectroscopy. The XRD data showed t...

Journal: :The Journal of investigative dermatology 2001
D X Nghiem N Kazimi G Clydesdale H N Ananthaswamy M L Kripke S E Ullrich

The ultraviolet radiation present in sunlight is the primary cause of nonmelanoma skin cancer and has been implicated in the development of cutaneous malignant melanoma. In addition, ultraviolet is immune suppressive and the suppression induced by ultraviolet radiation has been identified as a risk factor for skin cancer induction. Ultraviolet also suppresses the immune response to infectious a...

Journal: :تحقیقات نظام سلامت 0
شهرام نظری کارشناس ارشد، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی قم، قم، ایران اسرافیل عسگری کارشناس ارشد، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ارومیه، ارومیه، ایران رحیم عالی ده چناری استادیار، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ارومیه، ارومیه، ایران

background: given the increasing importance of suspended particles and reporting weather conditions in the amount of ultraviolet radiation in many countries, in this study, the data of the maximum amounts of pollution by suspended particles with the size of 10, 2.5 and1 microns (pm10, pm2.5, pm1) which were reported in 1-hour time-series and global ultraviolet index (uvi) were used to predict t...

Journal: :علوم و تکنولوژی پلیمر 0
آرش سعادت منفرد محسن محسنی

cerium oxide (ceria) nano particle, as photodegradation prevention agent was studied in water-based polyurethane clear coat  systems. polyurethane coatings show superior weathering resistance compared with acrylic melamine systems. however, any chemical change has detrimental effects on the property profile of pu coatings. coatings containing various amounts of cerium oxide nanoparticles were p...

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