Solar ultraviolet irradiance variations: a review

International Nuclear Information System (INIS)

Lean, J.

1987-01-01

Despite the geophysical importance of solar ultraviolet radiation, specific aspects of its temporal variations have not yet been adequately determined experimentally, nor are the mechanisms for the variability completely understood. Satellite observations have verified the reality of solar ultraviolet irradiance variations over time scales of days and months, and model calculations have confirmed the association of these short-term variations with the evolution and rotation of regions of enhanced magnetic activity on the solar disc. However, neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle. The comparative importance for the long-term variations of local regions of enhanced magnetic activity and global scale activity perturbations is still being investigated. Solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. Correlations with ground-based measures of solar variability are examined because of the importance of the ground-based observations as historical proxies of ultraviolet irradiance variations. Current problems in understanding solar ultraviolet irradiance variations are discussed, and the measurements planned for solar cycle 22, which may resolve these problems, are briefly described. copyright American Geophysical Union 1987

Effects of solar ultraviolet radiation on tropical algal communities

International Nuclear Information System (INIS)

Santas, R.

1989-01-01

This study assessed some of the effects of solar ultraviolet (UV) radiation ion coral reef algal assemblages. The first part of the investigation was carried out under controlled laboratory conditions in the coral reef microcosm at the National Museum of Natural History in Washington, D.C., while a field counterpart was completed at the Smithsonian Institution's marine station on Grand Turk, Turks and Caicos Islands, in the eastern Caribbean. The study attempted to separate the effects of UV-A from those of UV-B. In the laboratory, algal turf assemblages exposed to simulated solar UV radiation produced 55.1% less biomass than assemblages that were not exposed to UV. Assemblages not exposed to UV were dominated by Ectocarpus rhodochondroides, whereas in the assemblage developing under high UV radiation, Enteromorpha prolifera and eventually Schizothrix calcicola dominated. Lower UV-B irradiances caused a proportional reduction in biomass production and had less pronounced effects on species composition. UV-A did not have any significant effects on either algal turf productivity or community structure. In the field, assemblages exposed to naturally occurring solar UV supported a biomass 40% lower than that of assemblages protected from UV-B exposure. Once again, UV-A did not inhibit algal turf productivity

Protective mechanisms and acclimation to solar ultraviolet-B radiation in Oenothera stricta

Science.gov (United States)

Robberecht, R.; Caldwell, M. M.

1981-01-01

Plant adaptations ameliorating or repairing the damaging effects of ultraviolet-B (UV-B) radiation on plant tissue were investigated. The degree of phenotype plasticity in UV protective mechanisms and acclimation in relation to the natural solar UV-B radiation flux and in an enhanced UV-B irradiance environment was also examined. Mechanisms by which plants avoid radiation, adaptations altering the path of radiation incident on the leaf, and repair processes were considered. Attenuation of UV-B by tissues, UV-B irradiation into the leaf, and the effects of UV-B on photosynthesis were investigated.

Biological Sensors for Solar Ultraviolet Radiation

Directory of Open Access Journals (Sweden)

André P. Schuch

2011-04-01

Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

Experimental study of the ultraviolet global radiation in San Jose, Costa Rica

International Nuclear Information System (INIS)

Wright, J.

1996-01-01

The ultraviolet global radiation and the global solar radiation at San Jose, Costa Rica (latitude: 9 0 56', longitude: 84 0 54', altitude: 1.172 m.) during the period October 1993 to January 1995 were analyzed with respect to their seasonal variations and their independence. The dependence between the ultraviolet radiation and the clearness index of the skies was also investigated. A poor correlation was found between the quotient of the ultraviolet radiation (Hv/Hg) and between the global solar radiation and the extraterrestrial solar radiation (Hg/Ho). The correlation coefficient found between Hv/Hg and Hg/Ho was not greater than 0.25 for four categories of clearness index, i.e., covered skies, clear skies, and two intermediate conditions. This demonstrates that the ultraviolet radiation is not only associated with other atmospheric transmission conditions. A regression analysis between the hourly values of the ultraviolet and global radiation yielded a linear relationship with a determination coefficient greater than 98%. Thus a simple linear regression is reliable for the estimation of the ultraviolet in San Jose from global solar radiation data. (author) [es

Exposure to ultraviolet radiation: recommendations for cosmetic use

International Nuclear Information System (INIS)

Dias, C.; Carvalho, F.R.S.

2000-01-01

The beginning of the so-called tanning industry made possible the acquisition of a tanned skin independently of the available solar radiation. The tan is produced by ultraviolet radiation and, as well as in solar exposure, there are additional risks on the use of the so-called sun-beds. The damaging effects of ultraviolet exposure are well documented and reasonably quantified. The objective of this paper is to inform the potential effects of ultraviolet radiation exposure in sun-beds and to provide recommendations in order to reduce the associated risks. These recommendations are adapted for cosmetics use only (author)

The influence of meteorological factors on solar ultraviolet radiation over Pretoria, South Africa for the year 2012

CSIR Research Space (South Africa)

Makgabutlane, M

2013-09-01

Full Text Available Pretoria receives a fair amount of solar ultraviolet radiation (UVR). Certain meteorological factors affect the amount of solar UVR that reaches the ground. The most dominant influencing meteorological factors are stratospheric ozone, cloud cover...

Solar ultraviolet radiation and the risk of infectious disease: summary of a workshop

International Nuclear Information System (INIS)

Chapman, R.S.; Cooper, K.D.; De Faro, E.C.

1995-01-01

This invited review summarizes papers presented in a workshop on solar radiation and the risk of infectious disease. Nine reviewers cover the current state of knowledge in the following relevant fields:-ultraviolet climatology, infectious disease in humans, effects of U.V. from artificial light sources on animal and human immune systems, the influence of solar U.V. on animal and human immune systems, (lab, field, and clinical studies), biological consequences of unrepaired solar induced human DNA damage, and epidemiological considerations. Group discussions preceded the preparation of summary statements on each topic. Extensive bibliography. (UK)

Evolution of solar ultraviolet luminosity

International Nuclear Information System (INIS)

Zahnle, K.J.; Walker, J.C.G.

1982-01-01

In view of the major role of the sun in defining the properties of planetary atmospheres, their evolution cannot be fully understood outside the context of an evolving sun. The ultraviolet radiation is especially interesting because of its strong interaction with planetary atmospheres. We use astronomical observation of stars that are analogous to the sun in order to reconstruct a tentative account of the evolution of solar UV luminosity. A wealth of evidence indicates that the young sun was a much more powerful source of energetic particles and radiation than it is today. While on the main sequence, solar activity has declined as an inverse power law of age (between t -5 and t/sup -1.2/) as a consequence of angular momentum loss to the solar wind. Recent IUE satellite observations of premain sequence stars suggest that before the sun reached the main sequence (at an age of about 50 m.y.), it may have emitted as much as 10 4 times as much ultraviolet radiation (γ<2000 A) than it does today. These results could impact our understanding of the photochemistry and escape of constituents of primordial planetary atmospheres

Solar ultraviolet radiation response of EBT2 Gafchromic, radiochromic film

International Nuclear Information System (INIS)

Butson, Ethan T; Yu, Peter K N; Butson, Martin J

2013-01-01

Measurement of solar ultraviolet (UV) radiation is an important aspect of dosimetry for the improved knowledge of UV exposure and its associated health related issues. EBT2 Gafchromic film has been designed by its manufacturers as an improved tool for ionizing radiation dosimetry. The film is stated as exhibiting a significant reduction in UV response. However, results have shown that when exposed to UV from the ‘bottom side’ i.e. from the thick laminate side, the film exhibits a sensitivity to solar UV radiation which is both measurable and accurate for UV dosimetry. Films were irradiated in this position to known solar UV exposures and results are quantified showing a reproducibility of measurement to within ±7% (1 SD) when compared to calibrated UV meters. With an exposure of 20 J cm −2 broad spectrum solar UV, the films net OD change was found to be 0.248 OD ± 0.021 OD when analysing the results using the red channel region of an Epson V700 desktop scanner. This was compared to 0.0294 OD ± 0.0053 OD change with exposure to the same UV exposure from the top side. This means that solar UV dosimetry can be performed using EBT2 Gafchromic film utilizing the underside of the film for dosimetry. The main advantages of this film type for measurement of UV exposure is the visible colour change and thus easy analysis using a desktop scanner as well as its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

Energy Technology Data Exchange (ETDEWEB)

Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. ohoud-aljawi@hotmail.com (Malaysia)

2015-04-24

Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

Solar Electromagnetic Radiation Study for Solar Cycle 22: Solar Ultraviolet Irradiance, 120 to 300 NM: Report of Working Groups 2 and 3 of SOLERS 22

Science.gov (United States)

Rottman, G. J.; Cebula, R. P.; Gillotay, D.; Simon, P. A.

1996-01-01

This report summarizes the activities of Working Group 2 and Working Group 3 of the SOLax Electromagnetic Radiation Study for Solar Cycle 22 (SOLERS22) Program. The international (SOLERS22) is Project 1.2 of the Solar-Terrestrial Energy Program (STEP) sponsored by SCOSTEP, a committee of the International Council of Scientific Unions). SOLERS22 is comprised of five Working Groups, each concentrating on a specific wave-length range: WG-1 - visible and infrared, WG-2 - mid-ultraviolet (200 < A < 300 nm), WG-3 - Far-ultraviolet (lambda greater than 100 and lambda less than 200 nanometers), WG-4 - extreme-ultraviolet (lambda greater than 10 and lambda less than 100 nm), and WG-5 - X-ray (lambda greater than 1 and lambda less than 10 nano meters). The overarching goals of SOLERS22 are to: 1) establish daily solar irradiance values in the specified wavelength ranges, 2) consider the evolving solar structures as the cause of temporal variations, and 3) understand the underlying physical processes driving these changes.

Protective mechanisms and acclimation to solar ultraviolet-b radiation in oenothera stricta. Final report

International Nuclear Information System (INIS)

Robberecht, R.; Caldwell, M.M.

1981-12-01

Plant adaptations ameliorating or repairing the damaging effects of ultraviolet-B (UV-B) radiation on plant tissue were investigated. The degree of phenotype plasticity in UV protective mechanisms and acclimation in relation to the natural solar UV-B radiation flux and in an enhanced UV-B irradiance environment was also examined. Mechanisms by which plants avoid radiation, adaptations altering the path of radiation incident on the leaf, and repair processes were considered. Attenuation of UV-B by tissues, UV-B irradiation into the leaf, and the effects of UV-B on photosynthesis were investigated

Solar ultraviolet radiation measurements at South African and Reunion Island Coastal Sites: An indicator of public sun protection

CSIR Research Space (South Africa)

Wright, CY

2013-09-01

Full Text Available Solar ultraviolet radiation (UVR) has the potential to cause biological harm to humans. Intensity of solar UVR at the Earth’s surface depends on several factors, such as total column ozone and cloud cover, and temporal trends are usually dependent...

Protection from solar ultraviolet radiation by clothing

Energy Technology Data Exchange (ETDEWEB)

Pailthorpe, M. [New South Wales Univ., Kensington, NSW (Australia)

1996-12-31

The recently published Australia/New Zealand Standard AS/NZS 4399: l996 `Sun Protective Clothing - Evaluation and Classification` specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia`s most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 `sunsuits` have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin.

Protection from solar ultraviolet radiation by clothing

International Nuclear Information System (INIS)

Pailthorpe, M.

1996-01-01

The recently published Australia/New Zealand Standard AS/NZS 4399: l996 'Sun Protective Clothing - Evaluation and Classification' specifies an in vitro spectrophotometric method for the measurement of the ultraviolet (WR) transmission of textiles. Ultraviolet Protection Factors (UPF) are then calculated by convolving the UVR transmission data with standard CIE erythemal response data and ARL solar irradiance data. At the present time the scope of the standard is limited to loose fitting dry clothing. Virtually every textile parameter has an influence on the UPF of the finished garment and hence on the protection afforded to skin from the harmful effects of solar UVR radiation. Textile parameters such as fibre type, the method of spinning the yarn, fabric structure, cover factor, colorant, UVR absorbers and finishing methods determine the UPF of the fabric and hence must be controlled from batch to batch. Since garments generally shrink when washed, multiple wearing and washing cycles usually cause an increase in fabric UPF. Adventitious soiling of fabrics and the absorption of certain components of domestic laundry formulations, e g fluorescent whitening agents, increase fabric UPF ratings. Garments with a high degree of elasticity, e g nylon/lycra sportswear, that are stretched on to fit, will obviously have lower UPFs when stretched than when relaxed. In general fabrics worn in a wet state provide lower protection than when worn dry. On Australia's most extreme summer day it has been estimated that there are 30 MEDs (minimal erythemal doses) in a dawn to dusk exposure. Thus outdoor workers should be provided with UPF 30 clothing, or better. Results from recent experiments using SK-II hairless mice dressed in UPF 50 'sunsuits' have shown that the mice developed no sun induced skin cancers on the skin areas protected by the UPF 50 fabric whereas multiple tumours developed on the unprotected skin

Psoriasis and ultraviolet radiation

International Nuclear Information System (INIS)

Farber, E.M.; Nall, L.

1993-01-01

Prevention and detection screening programs as a public health service in curtailing the ever-increasing incidence of all forms of skin cancer are reviewed. The effect of solar and artificial ultraviolet radiation on the general population and persons with psoriasis is examined. 54 refs

An inexpensive setup for assessing the impact of ambient solar ultraviolet radiation on seedlings

International Nuclear Information System (INIS)

Adamse, P.; Reed, H.E.; Krizek, D.T.; Britz, S.J.; Mirecki, R.M.

1997-01-01

Because of reductions in stratospheric ozone levels due to chlorofluoromethanes and other trace gases, there has been growing concern about the impact of possible increases in ultraviolet-B (UV-B) radiation. Until recently, most studies have focused on the effects of enhanced UV-B levels, however, these have inherent technical difficulties. Ultraviolet-B exclusion studies afford the investigator a rapid means of assessing the effects of present levels of solar UV-B radiation. Unlike UV-B enhancement, UV-B exclusion studies use the sun as the source of UV-B radiation and selective filters to transmit or absorb this portion of sunlight. This article describes a simple, inexpensive system that was used over a 3-yr period to determine seedling response of cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.), and New Zealand spinach ((Tetragonia tetragonoides (Pallas) Kuntze) to UV-B exclusion. Plants of all three species grown outdoors under UV-B absorbing polyester showed an increase in leaf enlargement and biomass accumulation in comparison to those grown under UV-B transmitting cellulose acetate filters. The bask materials used consist of plastic window boxes, plastic filters that transmit or absorb in the UV-B region, wire supports, and binder clips. This setup can be used to demonstrate bask principles of photobiology and stress physiology. It is ideal for students interested in conducting short-term science projects on the effects of solar UV radiation

DNA damage and photosynthetic inhibition induced by solar ultraviolet radiation in tropical phytoplankton (Lake Titicaca, Bolivia)

NARCIS (Netherlands)

Helbling, EW; Villafane, VE; Buma, AGJ; Andrade, M; Zaratti, F

Experiments were conducted during October 1998 in Lake Titicaca, Bolivia (16 degrees S, 68 degrees W, 3810 m a.s.l), to determine the effects of solar ultraviolet radiation (UVR) on phytoplankton photosynthetic rates and DNA damage. Water samples were taken daily and incubated ir? situ or in

Outdoor Exposure to Solar Ultraviolet Radiation and Legislation in Brazil.

Science.gov (United States)

Silva, Abel A

2016-06-01

The total ozone column of 265 ± 11 Dobson Units in the tropical-equatorial zones and 283 ± 16 Dobson Units in the subtropics of Brazil are among the lowest on Earth, and as a result, the prevalence of skin cancer due to solar ultraviolet radiation is among the highest. Daily erythemal doses in Brazil can be over 7,500 J m. Erythemal dose rates on cloudless days of winter and summer are typically about 0.147 W m and 0.332 W m, respectively. However, radiation enhancement events yielded by clouds have been reported with erythemal dose rates of 0.486 W m. Daily doses of the diffuse component of erythemal radiation have been determined with values of 5,053 J m and diffuse erythemal dose rates of 0.312 W m. Unfortunately, Brazilians still behave in ways that lead to overexposure to the sun. The annual personal ultraviolet radiation ambient dose among Brazilian youths can be about 5.3%. Skin cancer in Brazil is prevalent, with annual rates of 31.6% (non-melanoma) and 1.0% (melanoma). Governmental and non-governmental initiatives have been taken to increase public awareness of photoprotection behaviors. Resolution #56 by the Agência Nacional de Vigilância Sanitária has banned tanning devices in Brazil. In addition, Projects of Law (PL), like PL 3730/2004, propose that the Sistema Único de Saúde should distribute sunscreen to members of the public, while PL 4027/2012 proposes that employers should provide outdoor workers with sunscreen during professional outdoor activities. Similar laws have already been passed in some municipalities. These are presented and discussed in this study.

The solar ultraviolet B radiation protection provided by shading devices with regard to its diffuse component.

Science.gov (United States)

Kudish, Avraham I; Harari, Marco; Evseev, Efim G

2011-10-01

The composition of the incident solar global ultraviolet B (UVB) radiation with regard to its beam and diffuse radiation fractions is highly relevant with regard to outdoor sun protection. This is especially true with respect to sun protection during leisure-time outdoor sun exposure at the shore and pools, where people tend to escape the sun under shade trees or different types of shading devices, e.g., umbrellas, overhangs, etc., believing they offer protection from the erythemal solar radiation. The degree of sun protection offered by such devices is directly related to the composition of the solar global UVB radiation, i.e., its beam and diffuse fractions. The composition of the incident solar global UVB radiation can be determined by measuring the global UVB (using Solar Light Co. Inc., Model 501A UV-Biometer) and either of its components. The beam component of the UVB radiation was determined by measuring the normal incidence beam radiation using a prototype, tracking instrument consisting of a Solar Light Co. Inc. Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The horizontal beam component of the global UVB radiation was calculated from the measured normal incidence using a simple geometric correlation and the diffuse component is determined as the difference between global and horizontal beam radiations. Horizontal and vertical surfaces positioned under a horizontal overhang/sunshade or an umbrella are not fully protected from exposure to solar global UVB radiation. They can receive a significant fraction of the UVB radiation, depending on their location beneath the shading device, the umbrella radius and the albedo (reflectance) of the surrounding ground surface in the case of a vertical surface. Shading devices such as an umbrella or horizontal overhang/shade provide relief from the solar global radiation and do block the solar global UVB radiation to some extent; nevertheless, a significant fraction of the solar global UVB

Solar Electromagnetic Radiation Study for Solar Cycle 22: Solar Ultraviolet Irradiance, 120 to 300 NM: Report of Working Groups 2 and 3 of SOLERS 22

Science.gov (United States)

Rottman, G. J.; Cebula, R. P.; Gillotay, D.; Simon, P. A.

1996-01-01

This report summarizes the activities of Working Group 2 and Working Group 3 of the SOLax Electromagnetic Radiation Study for Solar Cycle 22 (SOLERS22) Program. The international (SOLERS22) is Project 1.2 of the Solar-Terrestrial Energy Program (STEP) sponsored by SCOSTEP, a committee of the International Council of Scientific Unions). SOLERS22 is comprised of five Working Groups, each concentrating on a specific wave-length range: WG-1 - visible and infrared, WG-2 - mid-ultraviolet (200 solar irradiance values in the specified wavelength ranges, 2) consider the evolving solar structures as the cause of temporal variations, and 3) understand the underlying physical processes driving these changes.

ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS: III. PREDICTION OF IMPACTS IN SELECTED NORTHERN MIDWESTERN WETLANDS

Science.gov (United States)

The deleterious effects of solar ultraviolet radiation, especially the UV-B portion of sunlight, have been hypothesized to reduce survival, increase the frequency of malformations, and contribute to the apparent worldwide decline of many amphibian species.

New advances in protection against solar ultraviolet radiation in textiles for summer clothing.

Science.gov (United States)

Aguilera, José; de Gálvez, María Victoria; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

2014-01-01

Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection. © 2014 The American Society of Photobiology.

Solar ultraviolet radiation in a changing climate

Science.gov (United States)

The projected large increases in damaging ultraviolet radiation as a result of global emissions of ozone-depleting substances have been forestalled by the success of the Montreal Protocol. New challenges are now arising in relation to climate change. We highlight the complex inte...

Measuring and prediction of global solar ultraviolet radiation (0295-0385 μ m) under clear and cloudless skies

International Nuclear Information System (INIS)

Wright, Jaime

2008-01-01

Values of global solar ultraviolet radiation were measured with an ultraviolet radiometer and also predicted with a atmospheric spectral model. The values obtained with the atmospheric spectral model, based physically, were analyzed and compared with experimental values measured in situ. Measurements were performed for different zenith angles in conditions of clear skies in Heredia, Costa Rica. The necessary input data include latitude, altitude, surface albedo, Earth-Sun distance, as well as atmospheric characteristics: atmospheric turbidity, precipitable water and atmospheric ozone. The comparison between measured and predicted values have been successful. (author) [es

Novel photoinducible protective system in the Candida Guilliermondii under mid-ultraviolet radiation effect

International Nuclear Information System (INIS)

Frajkin, G.Ya.; Pinyaskina, E.V.; Strakhovskaya, M.G.

1995-01-01

Resistance of the Candida guilliermondii cells to ultraviolet radiation (290-320 nm, 400-750 nm) is studied. Presence of previously unknown photoinducible protective mechanism in yeasts, providing for increase in cell stability to mid-ultraviolet radiation, biologically most active in the solar radiation spectrum, is revealed. 9 refs.; 3 figs

Lunar dusty plasma: A result of interaction of the solar wind flux and ultraviolet radiation with the lunar surface

International Nuclear Information System (INIS)

Lisin, E A; Tarakanov, V P; Petrov, O F; Popel, S I

2015-01-01

One of the main problems of future missions to the Moon is associated with lunar dust. Solar wind flux and ultraviolet radiation interact with the lunar surface. As a result, there is a substantial surface change and a near-surface plasma sheath. Dust particles from the lunar regolith, which turned in this plasma because of any mechanical processes, can levitate above the surface, forming dust clouds. In preparing of the space experiments “Luna-Glob” and “Luna-Resource” particle-in-cell calculations of the near-surface plasma sheath parameters are carried out. Here we present some new results of particle-in-cell simulation of the plasma sheath formed near the surface of the moon as a result of interaction of the solar wind and ultraviolet radiation with the lunar surface. The conditions of charging and stable levitation of dust particles in plasma above the lunar surface are also considered. (paper)

Solar ultraviolet radiation in Syria measurements and relationship with skin cancer incidence

International Nuclear Information System (INIS)

Othman, I; Baydon, S.A.; Dawood, S.

1994-11-01

Seasonal variations of solar UVB (285-320) and UVA (320-400) were measured in three sites in Syria (33-37 N sup O) for two years: 1992-1993. UVB measurements were performed using polysulphone films and Robertson-Berger meter, while UVA measurements were done by NVA intensity meter. Two sets of measurements were carried out : - Maximal daily doses three times a week (every other day) - Diurnal variations from sun-rise to sun-set every two hours twice a month (every fortnight). The biological consequences of ultraviolet radiation withreference to some epidemiological data of skin cancer incidence in Syria since 1980 were discussed .(author). 36 refs., 21 figs., 11 tabs

Ultraviolet radiation in Finland

Energy Technology Data Exchange (ETDEWEB)

Taalas, P; Koskela, T; Damski, J; Supperi, A [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

1997-12-31

Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

Ultraviolet radiation in Finland

Energy Technology Data Exchange (ETDEWEB)

Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

1996-12-31

Solar ultraviolet radiation is damaging for living organisms due to its high energy pro each photon. The UV radiation is often separated into three regions according to the wavelength: UVC (200-280 nm), UVB (280-320 nm) and UVA (320-400 nm). The most hazardous part, UVC is absorbed completely in the upper atmosphere by molecular oxygen. UVB radiation is absorbed by atmospheric ozone partly, and it is reaching Earth`s surface, as UVA radiation. Besides atmospheric ozone, very important factors in determining the intensity of UVB radiation globally are the solar zenith angle and cloudiness. It may be calculated from global ozone changes that the clear-sky UVB doses may have enhanced by 10-15 % during spring and 5-10 % during summer at the latitudes of Finland, following the decrease of total ozone between 1979-90. The Finnish ozone and UV monitoring activities have become a part of international activities, especially the EU Environment and Climate Programme`s research projects. The main national level effort has been the Finnish Academy`s climatic change programme, SILMU 1990-95. This presentation summarises the scientific results reached during the SILMU project

Real-time measurement of outdoor worker's exposure to solar ultraviolet radiation in Pretoria, South Africa

Directory of Open Access Journals (Sweden)

Mmathapelo Makgabutlane

2015-05-01

Full Text Available The city of Pretoria in South Africa receives considerable solar ultraviolet radiation (UVR because of its low latitude (22–35°S and relatively clear skies. Certain meteorological factors affect the amount of solar UVR that reaches the ground; the most dominant factors being stratospheric ozone, cloud cover and solar zenith angle. It is known that overexposure to solar UVR may lead to the development of adverse health conditions, the most significant being skin cancer. Outdoor workers spend a significant amount of time outside and are thus susceptible to this risk. In this case study, we estimated, for the first time, the real-time solar UVR exposure of an outdoor worker in Pretoria. Measurements were made on 27 and 28 May 2013 using a handheld ultraviolet index (UVI meter calibrated against a science-grade biometer at the South African Weather Service in Pretoria. Personal exposure estimation was used to discern the pattern in diurnal and annual sunburn risk for the outdoor worker. Ambient UVR levels ranged from 0 UVI to 4.66 UVI and the outdoor worker’s potential exposure estimates regularly exceeded 80% of these levels depending on the time of day. The risk of sunburn was evident; however, actual incidents would depend on individual skin photosensitivity and melanin content, as well as sun protection used. Further research is needed to determine the personal exposure estimations of outdoor workers in other provinces in which solar UVR levels may be equally high, or higher than those in Pretoria.

A spectroscopic study on the effect of ultra-violet solar radiation in Antarctica on the human skin fibroblast cells

Directory of Open Access Journals (Sweden)

Tatsuyuki Yamamoto

2013-11-01

Full Text Available A study on the effect of the solar ultra-violet radiation on the human skin fibroblast cells revealed that the production of matrix metalloproteinase-2 was inhibited by the radiation. A CO2 incubator connected by optical fibers to a reflector telescope for collecting the solar light was built at Syowa station by the 49th Japanese Antarctica Research Expedition. The direction of the telescope was continuously controlled by a sun-tracker to follow the movement of the Sun automatically. The intensity of the collected light was monitored by a portable spectrophotometer housed inside. The human skin fibroblast cells were incubated in the CO2 chamber to investigate the effect of the solar radiation at Syowa station and were compared with those reference experiments at a laboratory in Japan. The results showed cell damage by strong UV radiation. The production of matrix metalloproteinase-2 was prompted by the moderate UV-B, but was inhibited by the strong UV-B radiation, as studied under laboratory conditions in Japan. The effect of strong solar radiation at Syowa station involving the radiation of UV-B region was estimated to be of the same extent of the radiation caused by an artificial UV-B light with the intensity more than 50 mJ/cm2.

Solar ultraviolet radiation is necessary to enhance grapevine fruit ripening transcriptional and phenolic responses.

Science.gov (United States)

Carbonell-Bejerano, Pablo; Diago, Maria-Paz; Martínez-Abaigar, Javier; Martínez-Zapater, José M; Tardáguila, Javier; Núñez-Olivera, Encarnación

2014-07-09

Ultraviolet (UV) radiation modulates secondary metabolism in the skin of Vitis vinifera L. berries, which affects the final composition of both grapes and wines. The expression of several phenylpropanoid biosynthesis-related genes is regulated by UV radiation in grape berries. However, the complete portion of transcriptome and ripening processes influenced by solar UV radiation in grapes remains unknown. Whole genome arrays were used to identify the berry skin transcriptome modulated by the UV radiation received naturally in a mid-altitude Tempranillo vineyard. UV radiation-blocking and transmitting filters were used to generate the experimental conditions. The expression of 121 genes was significantly altered by solar UV radiation. Functional enrichment analysis of altered transcripts mainly pointed out that secondary metabolism-related transcripts were induced by UV radiation including VvFLS1, VvGT5 and VvGT6 flavonol biosynthetic genes and monoterpenoid biosynthetic genes. Berry skin phenolic composition was also analysed to search for correlation with gene expression changes and UV-increased flavonols accumulation was the most evident impact. Among regulatory genes, novel UV radiation-responsive transcription factors including VvMYB24 and three bHLH, together with known grapevine UV-responsive genes such as VvMYBF1, were identified. A transcriptomic meta-analysis revealed that genes up-regulated by UV radiation in the berry skin were also enriched in homologs of Arabidopsis UVR8 UV-B photoreceptor-dependent UV-B -responsive genes. Indeed, a search of the grapevine reference genomic sequence identified UV-B signalling pathway homologs and among them, VvHY5-1, VvHY5-2 and VvRUP were up-regulated by UV radiation in the berry skin. Results suggest that the UV-B radiation-specific signalling pathway is activated in the skin of grapes grown at mid-altitudes. The biosynthesis and accumulation of secondary metabolites, which are appreciated in winemaking and

The Relationship between Ultraviolet Radiation Exposure and Vitamin D Status

Directory of Open Access Journals (Sweden)

Ola Engelsen

2010-05-01

Full Text Available This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due to decreased solar intensity and cold temperatures, which discourage skin exposure. During the mid-winter season, these factors result in decreased solar radiation exposure, hindering extensively the synthesis of vitamin D in these populations.

Assessment of integrated solar ultraviolet radiation by PM-355 detectors

International Nuclear Information System (INIS)

Abu-Jarad, F.; Al-Jarallah, M.I.; Elhadidy, M.A.; Shaahid, S.M.; Fazal-ur-Rehman

2000-01-01

The increase in environmental solar UV radiation due to depletion of ozone layer is a recent challenge to human health (skin cancer and eye effects) in countries having clear skies. Therefore, applying integrated, passive and inexpensive techniques to assess solar UV radiation is very much essential. Measurements of environmental solar UV radiation in Dhahran, Saudi Arabia area were carried out for a period of two months in the summer period in 1996 using two techniques in parallel namely: passive nuclear track detectors and active solar UV radiometers. Some of the nuclear track detectors were mounted in different conditions such as: under shadow band, on solar tracking mechanism following the solar rays. Others were mounted on perpendicular, tilted and horizontal surfaces in sunlight. All detectors were attached to a wooden background of the same thickness (0.5 cm) to eliminate interference of the heat effect of various support materials and have uniformity of the support materials. The assessment was carried out for different periods extending from two to nine weeks continuously. The investigated period covered the hottest months in Saudi Arabia (July and August) when the sky was clear of clouds. The results indicate linear correlation between alpha track diameters and the integrated exposure to solar UV as measured by the solar UV radiometer for all nuclear track detector positions and orientations. The highest slope has been observed for the detectors placed on solar tracking mechanism following the solar rays and the lowest from detectors oriented under the shadow band on horizontal position (measuring the diffused UV radiation only). The results show that most of the measured UV radiation (60%) were from the diffused UV radiation. The characteristics of the upper layer of the detectors are changed after chemical etching very quickly, with increase in the exposure time to UV solar radiation at certain orientation. The results encourage the use of nuclear track

Assessment of integrated solar ultraviolet radiation by PM-355 detectors

Energy Technology Data Exchange (ETDEWEB)

Abu-Jarad, F.; Al-Jarallah, M.I.; Elhadidy, M.A.; Shaahid, S.M.; Fazal-ur-Rehman

2000-06-01

The increase in environmental solar UV radiation due to depletion of ozone layer is a recent challenge to human health (skin cancer and eye effects) in countries having clear skies. Therefore, applying integrated, passive and inexpensive techniques to assess solar UV radiation is very much essential. Measurements of environmental solar UV radiation in Dhahran, Saudi Arabia area were carried out for a period of two months in the summer period in 1996 using two techniques in parallel namely: passive nuclear track detectors and active solar UV radiometers. Some of the nuclear track detectors were mounted in different conditions such as: under shadow band, on solar tracking mechanism following the solar rays. Others were mounted on perpendicular, tilted and horizontal surfaces in sunlight. All detectors were attached to a wooden background of the same thickness (0.5 cm) to eliminate interference of the heat effect of various support materials and have uniformity of the support materials. The assessment was carried out for different periods extending from two to nine weeks continuously. The investigated period covered the hottest months in Saudi Arabia (July and August) when the sky was clear of clouds. The results indicate linear correlation between alpha track diameters and the integrated exposure to solar UV as measured by the solar UV radiometer for all nuclear track detector positions and orientations. The highest slope has been observed for the detectors placed on solar tracking mechanism following the solar rays and the lowest from detectors oriented under the shadow band on horizontal position (measuring the diffused UV radiation only). The results show that most of the measured UV radiation (60%) were from the diffused UV radiation. The characteristics of the upper layer of the detectors are changed after chemical etching very quickly, with increase in the exposure time to UV solar radiation at certain orientation. The results encourage the use of nuclear track

Solar-blind ultraviolet band-pass filter based on metal—dielectric multilayer structures

International Nuclear Information System (INIS)

Wang Tian-Jiao; Xu Wei-Zong; Lu Hai; Ren Fang-Fang; Chen Dun-Jun; Zhang Rong; Zheng You-Dou

2014-01-01

Solar-blind ultraviolet (UV) band-pass filter has significant value in many scientific, commercial, and military applications, in which the detection of weak UV signal against a strong background of solar radiation is required. In this work, a solar-blind filter is designed based on the concept of “transparent metal”. The filter consisting of Al/SiO 2 multilayers could exhibit a high transmission in the solar-blind wavelength region and a wide stopband extending from near-ultraviolet to infrared wavelength range. The central wavelength, bandwidth, Q factor, and rejection ratio of the passband are numerically studied as a function of individual layer thickness and multilayer period. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Ultraviolet radiation response of two heterotropy Antarctic marine bacterial

International Nuclear Information System (INIS)

Hernandez, Edgardo A.; Ferreyra, Gustavo A.; Mac Cormack, Walter P.

2004-01-01

Two Antarctic marine bacterial strains, were exposed to different irradiance of ultraviolet (UV) solar radiation using several experimental protocols and interferential filters. Results showed that both, UV-A and UV-B radiation produce deleterious effects on two tested bacterial strains. The mortality values under UVB treatments were higher than those observed under UVA treatments. UVvi strain proved to be more resistant to UV radiation than the UVps strain. (author) [es

Rapid modulation of ultraviolet shielding in plants is influenced by solar ultraviolet radiation and linked to alterations in flavonoids.

Science.gov (United States)

Barnes, Paul W; Tobler, Mark A; Keefover-Ring, Ken; Flint, Stephan D; Barkley, Anne E; Ryel, Ronald J; Lindroth, Richard L

2016-01-01

The accumulation of ultraviolet (UV)-absorbing compounds (flavonoids and related phenylpropanoids) and the resultant decrease in epidermal UV transmittance (TUV ) are primary protective mechanisms employed by plants against potentially damaging solar UV radiation and are critical components of the overall acclimation response of plants to changing solar UV environments. Whether plants can adjust this UV sunscreen protection in response to rapid changes in UV, as occurs on a diurnal basis, is largely unexplored. Here, we use a combination of approaches to demonstrate that plants can modulate their UV-screening properties within minutes to hours, and these changes are driven, in part, by UV radiation. For the cultivated species Abelmoschus esculentus, large (30-50%) and reversible changes in TUV occurred on a diurnal basis, and these adjustments were associated with changes in the concentrations of whole-leaf UV-absorbing compounds and several quercetin glycosides. Similar results were found for two other species (Vicia faba and Solanum lycopersicum), but no such changes were detected in Zea mays. These findings reveal a much more dynamic UV-protection mechanism than previously recognized, raise important questions concerning the costs and benefits of UV-protection strategies in plants and have practical implications for employing UV to enhance crop vigor and quality in controlled environments. © 2015 John Wiley & Sons Ltd.

Ecological and nonhuman biological effects of solar UV-B radiation

International Nuclear Information System (INIS)

Worrest, R.C.

1984-01-01

Recent studies regarding the impact of UV-B radiation upon ecological and nonhuman biological systems is the subject of the report. For years scientists and laymen alike have causally noted the impact of solar ultraviolet radiation upon the nonhuman component of the biosphere. Stratospheric ozone functions effectively as an ultraviolet screen by filtering out solar radiation in the 220-320 nm waveband as it penetrates through the atmosphere, thus allowing only small amounts of the longer wavelengths of radiation in the waveband to leak through to the surface of the earth. Although this radiation (UV-B radiation, 290-320 nm) comprises only a small fraction (lesser tha 1%) of the total solar spectrum, it can have a major impact on biological systems due to its actinic nature. Many organic molecules, most notably DNA, absorb UV-B radiation which can initiate photochemical reactions. It is life's ability, or lack thereof, to cope with enhanced levels of solar UV-B radiation that has generated concern over the potential depletion of stratospheric ozone

Ultraviolet Radiation in the Solar System

CERN Document Server

Vázquez, M

2006-01-01

UV radiation is an important part in the electromagnetic spectrum since the energy of the photons is great enough to produce important chemical reactions in the atmospheres of planets and satellites of our Solar System, thereby affecting the transmission of this radiation to the ground and its physical properties. Scientists have used different techniques (balloons and rockets) to access to the information contained in this radiation, but the pioneering of this new frontier has not been free of dangers. The Sun is our main source of UV radiation and its description occupies the first two chapters of the book. The Earth is the only known location where life exists in a planetary system and therefore where the interaction of living organism with UV radiation can be tested through different epochs and on distinct species. The development of the human technology has affected the natural shield of ozone that protects complex lifeforms against damaging UV irradiation. The formation of the ozone hole and its consequ...

Solar Simulated Ultraviolet Radiation Induces Global Histone Hypoacetylation in Human Keratinocytes.

Science.gov (United States)

Zhang, Xiaoru; Kluz, Thomas; Gesumaria, Lisa; Matsui, Mary S; Costa, Max; Sun, Hong

2016-01-01

Ultraviolet radiation (UVR) from sunlight is the primary effector of skin DNA damage. Chromatin remodeling and histone post-translational modification (PTM) are critical factors in repairing DNA damage and maintaining genomic integrity, however, the dynamic changes of histone marks in response to solar UVR are not well characterized. Here we report global changes in histone PTMs induced by solar simulated UVR (ssUVR). A decrease in lysine acetylation of histones H3 and H4, particularly at positions of H3 lysine 9, lysine 56, H4 lysine 5, and lysine 16, was found in human keratinocytes exposed to ssUVR. These acetylation changes were highly associated with ssUVR in a dose-dependent and time-specific manner. Interestingly, H4K16ac, a mark that is crucial for higher order chromatin structure, exhibited a persistent reduction by ssUVR that was transmitted through multiple cell divisions. In addition, the enzymatic activities of histone acetyltransferases were significantly reduced in irradiated cells, which may account for decreased global acetylation. Moreover, depletion of histone deacetylase SIRT1 in keratinocytes rescued ssUVR-induced H4K16 hypoacetylation. These results indicate that ssUVR affects both HDAC and HAT activities, leading to reduced histone acetylation.

Occupational applications of ultraviolet radiation

International Nuclear Information System (INIS)

Eriksen, P.

1987-01-01

A large population of workers are exposed to ultraviolet radiation in various occupational environments which often necessitates protection. Since ultraviolet radiation may create other environmental problems an occupational hazard- and protection evaluation can be complicated. Threshold Limit Values adopted by the American Conference of Governmental Industrial Hygienists (ACGIH) on ultraviolet radiation are used in most countries as guidelines for risk assessment and control measures. This review addresses the levels of ultraviolet radiation met in occupational environments, its measurement and evaluation, and discusses different protection methods. Ultraviolet lasers are beginning to find their way into industrial processes but are still limited in number and they will not be covered here. Emphasis is on broad band incoherent radiation in high risk environments such as welding, and on the evaluation of protective eyewear, see-through curtains and plastics. Other occupational risks associated with the emission of ultraviolet radiation are discussed

Photodetector of ultraviolet radiation

International Nuclear Information System (INIS)

Dorogan, V.; Branzari, V.; Vieru, T.; Manole, M.; Canter, V.

2000-01-01

The invention relates to photodetectors on base of semiconductors of ultraviolet radiation and may be used in optoelectronic system for determining the intensity and the dose of ultraviolet radiation emitted by the Sun or other sources. Summary of the invention consists in the fact that in the photodetector of ultraviolet radiation the superficial potential barrier is divided into two identical elements, electrically isolated each of the other, one of them being covered with a layer of transparent material for visible and infrared radiation and absorption the ultra violet radiation. The technical result consists in mutual compensation of visible and infrared components of the radiation spectrum

Minimum exposure limits and measured relationships between the vitamin D, erythema and international commission on non-ionizing radiation protection solar ultraviolet.

Science.gov (United States)

Downs, Nathan; Parisi, Alfio; Butler, Harry; Turner, Joanna; Wainwright, Lisa

2015-01-01

The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for exposure to ultraviolet radiation in outdoor occupational settings. Spectrally weighted ICNIRP ultraviolet exposures received by the skin or eye in an 8 h period are limited to 30 J m(-2). In this study, the time required to reach the ICNIRP exposure limit was measured daily in 10 min intervals upon a horizontal plane at a subtropical Australian latitude over a full year and compared with the effective Vitamin D dose received to one-quarter of the available skin surface area for all six Fitzpatrick skin types. The comparison of measured solar ultraviolet exposures for the full range of sky conditions in the 2009 measurement period, including a major September continental dust event, show a clear relationship between the weighted ICNIRP and the effective vitamin D dose. Our results show that the horizontal plane ICNIRP ultraviolet exposure may be used under these conditions to provide minimum guidelines for the healthy moderation of vitamin D, scalable to each of the six Fitzpatrick skin types. © 2014 The American Society of Photobiology.

Effect of ultraviolet-B radiation on biochemical and antioxidant ...

African Journals Online (AJOL)

user

The stratospheric ozone depletion and enhanced solar ultraviolet-B (UV-B) ... mechanism produced by enzymatic antioxidant such as catalase, peroxidase, ... absorb UV-B and prevent it from penetrating into the leaf mosophyll cells. The aim of this work was to investigate the effects of UV-B radiation on Indigofera tinctoria ...

Effectiveness of eye drops protective against ultraviolet radiation.

Science.gov (United States)

Daxer, A; Blumthaler, M; Schreder, J; Ettl, A

1998-01-01

To test the effectiveness of commercially available ultraviolet (UV)-protective eye drops (8-hydroxy-1-methylchinolinium methylsulphate) which are recommended for protection against both solar and artificial UV radiation. The spectral transmission in the wavelength range from 250 to 500 nm was investigated in 1-nm steps using a high-resolution double monochromator with holographic gratings of 2,400 lines/mm and a 1,000-watt halogen lamp as light source. The transmission spectrum was measured for different values of the layer thickness. The transmission of a liquid layer of about 10 microns, which corresponds to the thickness of the human tear film, shows a cut-off at 290 nm with a transmission of about 25-50% at shorter wavelengths. For wavelengths longer than 290 nm the transmission is higher than 90%. The threshold time ratio for keratitis formation with and without eye drops is above 0.93 considering solar radiation on the earth's surface and above 0.65 considering radiation from arc-welding, respectively. The transmission spectrum of the eye drops under realistic conditions does not show a protective effect against solar UV radiation. However, there exists reduction of UVC radiation in the spectral range typical of artificial UV sources such as arc-welding. We cannot recommend the application of these eye drops as an UV-protective aid against eye damage by solar UV radiation.

Near-ultraviolet radiation blocks SOS responses to DNA damage in Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Turner, M.A.; Eisenstark, A.

1984-01-01

Escherichia coli cells in which the recA promoter is fused to a lac structural gene, (Mu) Mud(Ap,lac)::rec, were irradiated with two far-ultraviolet light wavelengths (254 and 290 nm), selected monochromatic near-ultraviolet (NUV) wavelengths 313 nm, 334 nm, 365 nm, or broad band solar-UV (290-420 nm) from a solar simulator. Irradiation with the two far-ultraviolet wavelengths was followed by high yields of ..beta..-galactosidase, lambda prophage induction, and Weigle reactivation. These end points were not observed after irradiation with the selected NUV wavelengths or the broad spectrum solar-UV. Thus, neither broad spectrum solar-UV nor monochromatic NUV wavelengths resulted in the derepression of the recA promoter. Further, prior exposure of the cells either to the selected monochromatic NUV wavelengths or to solar-UV inhibited a) the induction of ..beta..-galactosidase by subsequent 254-nm radiation, b) subsequent 254-nm induction of lambda prophage, c) Weigle reactivation, and d) mutation frequency. These observations are consistent with the hypothesis that NUV blocks subsequent recA protease action.

Improved Statistical Model Of 10.7-cm Solar Radiation

Science.gov (United States)

Vedder, John D.; Tabor, Jill L.

1993-01-01

Improved mathematical model simulates short-term fluctuations of flux of 10.7-cm-wavelength solar radiation during 91-day averaging period. Called "F10.7 flux", important as measure of solar activity and because it is highly correlated with ultraviolet radiation causing fluctuations in heating and density of upper atmosphere. F10.7 flux easily measureable at surface of Earth.

Solar radiation measurements at the network of six sites in the UK, January - December 2001

Energy Technology Data Exchange (ETDEWEB)

Driscoll, C.M.H.; Campbell, J.I.; Pearson, A.J.; Grainger, K.J.L.; Dean, S.F.; Clark, I.E

2002-04-01

A summary of the results from January to December 2001 of a survey of solar radiation levels at the UK network of six solar radiation measurement sites is presented. The network consists of three NRPB sites at Chilton, Leeds and (monitoring since 1988) and three Meteorological Office stations at Camborne, Kinloss and Lerwick (monitoring since 1993). Visible (400-770 nm), ultraviolet UVA radiation (320-400 nm) and erythemally weighted ultraviolet radiation UVR{sub eff} (280-400 nm) have been measured simultaneously using a three detector measurement system. Results are compared with calculated irradiances of ultraviolet radiation and published illuminance data, and with data for the measurement period from 1988 to 2000. Yearly reports have been produced for selected sites, giving the daily solar index (which is a measure of the sunburn potential for sensitive skin types) throughout the year. (author)

Solar radiation measurements at the network of six sites in the UK, January - December 2001

International Nuclear Information System (INIS)

Driscoll, C.M.H.; Campbell, J.I.; Pearson, A.J.; Grainger, K.J.L.; Dean, S.F.; Clark, I.E.

2002-01-01

A summary of the results from January to December 2001 of a survey of solar radiation levels at the UK network of six solar radiation measurement sites is presented. The network consists of three NRPB sites at Chilton, Leeds and (monitoring since 1988) and three Meteorological Office stations at Camborne, Kinloss and Lerwick (monitoring since 1993). Visible (400-770 nm), ultraviolet UVA radiation (320-400 nm) and erythemally weighted ultraviolet radiation UVR eff (280-400 nm) have been measured simultaneously using a three detector measurement system. Results are compared with calculated irradiances of ultraviolet radiation and published illuminance data, and with data for the measurement period from 1988 to 2000. Yearly reports have been produced for selected sites, giving the daily solar index (which is a measure of the sunburn potential for sensitive skin types) throughout the year. (author)

Spectral properties of plant leaves pertaining to urban landscape design of broad-spectrum solar ultraviolet radiation reduction

Science.gov (United States)

Yoshimura, Haruka; Zhu, Hui; Wu, Yunying; Ma, Ruijun

2010-03-01

Human exposure to harmful ultraviolet (UV) radiation has important public health implications. Actual human exposure to solar UV radiation depends on ambient UV irradiance, and the latter is influenced by ground reflection. In urban areas with higher reflectivity, UV exposure occurs routinely. To discover the solar UV radiation regulation mechanism of vegetation, the spectral reflectance and transmittance of plant leaves were measured with a spectrophotometer. Typically, higher plants have low leaf reflectance (around 5%) and essentially zero transmittance throughout the UV region regardless of plant species and seasonal change. Accordingly, incident UV radiation decreases to 5% by being reflected and is reduced to zero by passing through a leaf. Therefore, stratified structures of vegetation are working as another terminator of UV rays, protecting whole terrestrial ecosystems, while vegetation at waterfronts contributes to protect aquatic ecosystems. It is possible to protect the human population from harmful UV radiation by urban landscape design of tree shade and the botanical environment. Even thin but uniformly distributed canopy is effective in attenuating UV radiation. To intercept diffuse radiation, UV screening by vertical structures such as hedges should be considered. Reflectivity of vegetation is around 2%, as foliage surfaces reduce incident UV radiation via reflection, while also eliminating it by transmittance. Accordingly, vegetation reduces incident UV radiation to around 2% by reflection. Vegetation influence on ambient UV radiation is broad-spectrum throughout the UV region. Only trees provide cool UV protective shade. Urban landscapes aimed at abating urban heat islands integrated with a reduction of human UV over-exposure would contribute to mitigation of climate change.

CLASSICS Handbook of Solar Radiation Data for India

Indian Academy of Sciences (India)

Srimath

Handbook of Solar Radiation Data for India. By Anna Mani. CHAPTER 1. Introduction. 1.1. The sun and its radiation. The electromagnetic radiation emitted by the sun covers a very large range of wave- lengths, from radiowaves through the infrared, visible and ultraviolet to X-rays and gamma rays. However, 99 per cent of ...

Ultraviolet radiation and cyanobacteria.

Science.gov (United States)

Rastogi, Rajesh Prasad; Sinha, Rajeshwar P; Moh, Sang Hyun; Lee, Taek Kyun; Kottuparambil, Sreejith; Kim, Youn-Jung; Rhee, Jae-Sung; Choi, Eun-Mi; Brown, Murray T; Häder, Donat-Peter; Han, Taejun

2014-12-01

Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of Software for Measurement and Analysis of Solar Radiation

International Nuclear Information System (INIS)

Mohamad Idris Taib; Abul Adli Anuar; Noor Ezati Shuib

2015-01-01

This software was under development using LabVIEW to be using with StellarNet spectrometers system with USB communication to computer. LabVIEW have capabilities in hardware interfacing, graphical user interfacing and mathematical calculation including array manipulation and processing. This software read data from StellarNet spectrometer in real-time and then processed for analysis. Several measurement of solar radiation and analysis have been done. Solar radiation involved mainly infra-red, visible light and ultra-violet. With solar radiation spectrum data, information of weather and suitability of plant can be gathered and analyzed. Furthermore, optimization of utilization and safety precaution of solar radiation can be planned. Using this software, more research and development in utilization and safety of solar radiation can be explored. (author)

Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

International Nuclear Information System (INIS)

Kamarudin, S. U.; Gopir, G.; Yatim, B.; Sanusi, H.; Mahmud, P. S. Megat; Choo, P. Y.

2010-01-01

The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2 degree sign 55' N, 101 degree sign 46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3 degree sign 06' N, 101 degree sign 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298±105) kJm -2 while the total daily maximum is (600±56) kJm -2 . From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.

Harmful effects of ultraviolet radiation

International Nuclear Information System (INIS)

Anon.

1989-01-01

Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

Establishing a ultraviolet radiation observational network and enhancing the study on ultraviolet radiation

Science.gov (United States)

Bai, Jianhui; Wang, Gengchen

2003-09-01

On the basis of analyzing observational data on solar radiation, meteorological parameters, and total ozone amount for the period of January 1990 to December 1991 in the Beijing area, an empirical calculation method for ultraviolet radiation (UV) in clear sky is obtained. The results show that the calculated values agree well with the observed, with maximum relative bias of 6.2% and mean relative bias for 24 months of 1.9%. Good results are also obtained when this method is applied in Guangzhou and Mohe districts. The long-term variation of UV radiation in clear sky over the Beijing area from 1979 to 1998 is calculated, and the UV variation trends and causes are discussed: direct and indirect UV energy absorption by increasing pollutants in the troposphere may have caused the UV decrease in clear sky in the last 20 years. With the enhancement of people’s quality of life and awareness of health, it will be valuable and practical to provid UV forecasts for typical cities and rural areas. So, we should develop and enhance UV study in systematic monitoring, forecasting, and developing a good and feasible method for UV radiation reporting in China, especially for big cities.

Photodetector of ultra-violet radiation

International Nuclear Information System (INIS)

Dorogan, V.; Vieru, T.; Coseac, V.; Chirita, F.

1999-01-01

The invention relates to photodetectors on the semiconductors base, in particular, to photodetectors of ultra-violet radiation and can be used in the optoelectronics systems for determining the intensity and dose of ultraviolet radiation emitted by the Sun and other sources. In the structure of the photodetector of ultraviolet radiation with a superficial potential barrier formed of semiconductors A 3 B 5 with the prohibited power width Eg 1 , solid solutions thereof with the prohibited power width Eg 2 and SnO 2 or ITO, in the semiconductors A 3 B 5 at a surface distance less than the absorption length of the visible radiation it is formed an isotype heterojunction between the semiconductors A 3 B 5 and solid solutions thereof with the prohibited power width Eg 2 > Eg 1 . The technical result consists in manufacturing of a photodetector sensitive solely to the ultraviolet radiation

Maps of ultraviolet radiation in Costa Rica

International Nuclear Information System (INIS)

Wright, Jaime

2009-01-01

Ultraviolet radiation (UV) has contributed relatively little energy to the solar spectrum; but is important, because it is biologically active. The software Surfer 8 has created maps designed of the territory of Costa Rica to assess the maximum levels of solar UV radiation on a horizontal plane. The data were used in creating the maps, were predicted at local noon in eighty-three locations scattered across the country, with a spectral atmospheric model which is physically established. The model has used as input data: the date and time, the location identified by latitude, longitude and height of land above sea level, the value of the vertical column ozone, surface albedo and atmospheric turbidity parameters. The estimate differs by 3% of the measurements made in situ, which agrees with the experimental data. The model has used the data estimation of UV radiation, clear sky conditions, which is the condition where you get the maximum energy possible in each locality. This is of fundamental importance when assessing the adverse effects on human health, leads the maximum intensity in this important solar spectrum band. A larger increase of 23% has presented in the UV radiation with altitude obtaining the hills and mountains the highest rates and places located at sea level and the lowest cost, the indices. The annual variation analysis has revealed an increase greater than 27% from the month of lowest UV radiation (December) and the month of greatest UV radiation (April). The issue is of particular interest because of the increasing number of people moving at different times of the year, altitudes over 2000 m altitude, in activities relating to tourism and employment. These individuals are significant increases in levels of UV solar radiation under conditions of clear skies. (author) [es

Estimation of hourly ultraviolet solar irradiance in the semi-arid northeast region of Brasil

Energy Technology Data Exchange (ETDEWEB)

Andrade, Ricardo C. de; Tiba, Chigueru [Dept. de Energia Nuclear da Univ. Federal de Pernambuco, Recife, Pernambuco (Brazil)

2008-07-01

Two computational codes, SPCTRAL2 and SMARTS2, were used for estimating ultraviolet solar irradiance in a locality of the semi-arid region of the Northeast of Brazil. The softwares presented simplicity of use, precision and relative ease in obtaining the input variables: zenith angle, atmospheric pressure in relation to sea level, relative humidity of the air, amount of precipitable water, total ozone and the aerosol optic depths (AOD). All these variables are measured in conventional meteorological stations, except for the aerosol optic depth. The AOD was measured with an apparatus that was constructed with a narrow band LED sensor, centered in 555nm which measures the monochromatic radiation transmission through the terrestrial atmosphere, which can be described by Beer's law. The measurements for obtaining the AOD were carried out during the months of December, 2006 and January, 2007 for Pesqueira-PE (Longitude -36.77 and Latitude 8.4 ) semi-arid region of Pernambuco, at intervals of 10 and 10 minutes, simultaneously. The ultraviolet solar irradiation was measured with a TURV (Total Ultraviolet Radiometer) Eppley Pyranometer on a minute scale. The computational simulations with SPCTRAL2 and SMARTS2 were made considering the following cases: (a) obtention of daily AOD, or be it, coming from the linear extrapolation of all the data along the day (b) obtention of hourly AOD, or be it the linearization by parts (piecewise). In the first case, the results of the simulations of ultraviolet solar irradiance and ultraviolet radiation index show an error of 4% and 13% for solar midday, and 78% at end of afternoon, when compared with the values measured with the TURV pyranometer. These results were significantly improved when using the AOD obtained on hourly bases: an error of 6.7 % for solar midday, a maximum error of 10% between 11 and 13 h, a maximum error of 20% between 10 and 14h and finally a maximum error of 30% between 9 and 15h. (orig.)

Higher plant acclimation to solar ultraviolet-B radiation

International Nuclear Information System (INIS)

Robberecht, R.

1981-01-01

The objectives of this study were to determine: (1) the relationship between plant sensitivity and epidermal uv attenuation, (2) the effect of phenotypic changes in the leaf epidermis, resulting from uv-B exposure, on plant sensitivity to uv radiation, and (3) the platicity of these changes in the epidermis leading to plant acclimation to uv-B radiation. A mechanism of uv-B attenuation, possibly involving the biosynthesis of uv-absorbing flavonoid compounds in the epidermis and mesophyll under the stress of uv-B radiation, and a subsequent increase in the uv-B attenuation capacity of the epidermis, is suggested. The degree of plant sensitivity and acclimation to natural and intensified solar uv-B radiation may involve a dynamic balance between the capacity for uv-B attenuation and uv-radiation-repair mechanisms in the leaf

Prostate cancer incidence in Australia correlates inversely with solar radiation.

Science.gov (United States)

Loke, Tim W; Seyfi, Doruk; Sevfi, Doruk; Khadra, Mohamed

2011-11-01

What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States. • To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia. • Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined. • Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades. •  There exists an association between less solar radiation and higher prostate cancer incidence in Australia. © 2011 THE AUTHORS. BJU

Effects of increased solar ultraviolet radiation on biogeochemical cycles

International Nuclear Information System (INIS)

Zepp, R.G.; Callaghan, T.V.; Erickson, D.J.

1995-01-01

Increases in solar UV radiation could affect terrestrial and aquatic biogeochemical cycles thus altering both sources and sinks of greenhouse and chemically important trace gases (e.g., carbon dioxide (CO2), carbon monoxide (CO), carbonyl sulfide (COS). In terrestrial ecosystems, increased UV-B could modify both the production and decomposition of plant matter with concomitant changes in the uptake and release of atmospherically important trace gases. Decomposition processes can be accelerated when UV-B photodegrades surface litter, or retarded when the dominant effect involves changes in the chemical composition of living tissues that reduce the biodegradability of buried litter. These changes in decomposition can affect microbial production of CO2 and other trace gases and also may affect the availability of nutrients essential for plant growth. Primary production can be reduced by enhanced UV-B, but the effect is variable between species and even cultivars of some crops. Likewise, the effects of enhanced UV-B on photoproduction of CO from plant matter is species-dependent and occurs more efficiently from dead than from living matter. Aquatic ecosystems studies in several different locations have shown that reductions in current levels of solar UV-B result in enhanced primary production, and Antarctic experiments under the ozone hole demonstrated that primary production is inhibited by enhanced UV-B. In addition to its effects on primary production, solar UV radiation can reduce bacterioplankton growth in the upper ocean with potentially important effects on marine biogeochemical cycles. Decomposition processes can be retarded when bacterial activity is suppressed by enhanced UV-B radiation or stimulated when solar UV radiation photodegrades aquatic dissolved organic matter. Photodegradation of DOM results in loss of UV absorption and formation of dissolved inorganic carbon, CO, and organic substrates that are readily mineralized or taken up by aquatic

Effects of solar PAR and UV radiation on tropical biofouling communities

KAUST Repository

Dobretsov, SV; Gosselin, L; Qian, P

2010-01-01

We investigated the effect of solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) on the development of tropical micro- and macrofouling communities for 30 d. The experimental design involved 3 treatments: full spectrum

Ultraviolet radiation after exposure to a low-fluence IPL home-use device

DEFF Research Database (Denmark)

Thaysen-Petersen, Daniel; Erlendsson, Andres M; Nash, J F

2015-01-01

The prevailing advice is to avoid sun exposure after intense pulsed light (IPL) hair removal. However, no systematic evaluation of ultraviolet radiation (UVR) after IPL hair removal exits. Therefore, we investigated the occurrence of side effects in subjects receiving solar-simulated UVR after...

SIMULATED SOLAR ULTRAVIOLET RADIATION EFFECTS ON 5 SPECIES OF SCLERACTINIAN CORALS

Science.gov (United States)

The impact of global climate change factors such as increased temperature and ultraviolet radiation (UVR) on coral bleaching are of continued interest to the USEPA. Coral bleaching occurs when symbiotic zooxanthellae and/or their pigments are depleted in response to stressors suc...

Establishment of a dosimetry method for the exposure evaluation to the ultraviolet radiation

International Nuclear Information System (INIS)

Gronchi, Claudia Carla

2009-01-01

A dosimetric method for the exposure evaluation to ultraviolet radiation was established with Al 2 O 3 :C InLight detectors and an OSL microStar reader and software, of Landauer, associated to the techniques of Optically Stimulated Luminescence (OSL) and Photo transferred Optically Stimulated Luminescence (PTOSL). The main phases of this work were: characterization of the Al 2 O 3 :C InLight detectors, without pre-conditioning, exposed to ultraviolet radiation (RUV) of solar and artificial sources, using the OSL technique; characterization of the Al 2 O 3 :C InLight detectors, pre-conditioned, exposed to RUV solar and artificial sources, using the PTOSL technique; practical applications of the Al 2 O 3 :C InLight detectors to the solar and artificial RUV, originating from TIG (Tungsten Inert Gas) and electric welding. The Al 2 O 3 :C InLight detectors presented satisfactory OSL and PTOSL responses in relation to the parameters: wavelength, UV illumination time, irradiance, radiance exposure and angular dependence to the RUV. Those detectors presented maximum OSL and PTOSL stimulation for the wavelength of 330 nm, showing that they are may be useful for UVA radiation detection and dosimetry. (author)

Solar Radiation and Climate Experiment (SORCE) Satellite

Science.gov (United States)

2003-01-01

This is a close-up of the NASA-sponsored Solar Radiation and Climate Experiment (SORCE) Satellite. The SORCE mission, launched aboard a Pegasus rocket January 25, 2003, will provide state of the art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. Critical to studies of the Sun and its effect on our Earth system and mankind, SORCE will provide measurements that specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. Orbiting around the Earth accumulating solar data, SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolo meters engineered into instruments mounted on a satellite observatory. SORCE is carrying 4 instruments: The Total Irradiance Monitor (TIM); the Solar Stellar Irradiance Comparison Experiment (SOLSTICE); the Spectral Irradiance Monitor (SIM); and the XUV Photometer System (XPS).

Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation

Science.gov (United States)

Lubin, Dan; Arrigo, Kevin R.; van Dijken, Gert L.

2004-05-01

Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone ``hole'' was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors of the Southern Ocean, impacting 60% of the surface biomass by the late 1990s. These results suggest two reasons why more serious impacts to the base of the marine food web may not have been detected by field experiments: (1) the onset of UVR increases several years before dedicated field work began may have impacted the most sensitive organisms long before such damage could be detected, and (2) most biological field work has so far not taken place in Antarctic waters most extensively subjected to enhanced UVR.

Ultraviolet-radiation-curable paints

Energy Technology Data Exchange (ETDEWEB)

Grosset, A M; Su, W F.A.; Vanderglas, E

1981-09-30

In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

NEW Fe IX LINE IDENTIFICATIONS USING SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR ULTRAVIOLET MEASUREMENT OF EMITTED RADIATION AND HINODE/EIS JOINT OBSERVATIONS OF THE QUIET SUN

International Nuclear Information System (INIS)

Landi, E.; Young, P. R.

2009-01-01

In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s 2 3p 5 4p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 A and 700-850 A wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation.

Glacial Influences on Solar Radiation in a Subarctic Sea.

Science.gov (United States)

Understanding macroscale processes controlling solar radia­tion in marine systems will be important in interpreting the potential effects of global change from increasing ultraviolet radiation (UV) and glacial retreat. This study provides the first quantitative assessment of UV i...

The measurement of ultraviolet radiation and sunburn time over southern Ontario

Science.gov (United States)

Evans, W. F. J.

1994-01-01

Studies of the depletion of ozone which have been conducted from the TOMS instrument on the NIMBUS 7 satellite indicate that total ozone has declined by 5 percent over the last 12 years at most mid-latitudes in the Northern Hemisphere typical of southern Ontario. The measurement of the actual resultant increases in UVB is now important. A monitoring program of UVB (biologically active solar ultraviolet radiation) has been conducted for the last 24 months at a site near Bolton, Ontario. The sunburn time varies from less than 17 minutes in late July, to over 4 hours in December on clear days. The levels depend on solar insolation and total ozone column. The ultraviolet levels are strongly affected by cloud and sky conditions. The implications of present and future depletion on the sunburn time are discussed.

UV radiation hardness of silicon inversion layer solar cells

International Nuclear Information System (INIS)

Hezel, R.

1990-01-01

For full utilization of the high spectral response of inversion layer solar cells in the very-short-wavelength range of the solar spectrum sufficient ultraviolet-radiation hardness is required. In addition to the charge-induced passivation achieved by cesium incorporation into the silicon nitride AR coating, in this paper the following means for further drastic reduction of UV light-induced effects in inversion layer solar cells without encapsulation are introduced and interpretations are given: increasing the nitride deposition temperature, silicon surface oxidation at low temperatures, and texture etching and using higher substrate resistivities. High UV radiation tolerance and improvement of the cell efficiency could be obtained simultaneously

Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit

Science.gov (United States)

Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

1991-01-01

Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

Impact of solar ultraviolet radiation on atopic dermatitis symptoms in young children: A longitudinal study.

Science.gov (United States)

Kim, Young-Min; Kim, Jihyun; Lee, Ji Young; Kim, Minji; Kim, Hyunmi; Jung, Kwon; Eo, Soomi; Ahn, Mijin; Ahn, Kangmo

2017-09-01

There are controversial data about the effects of sun exposure on atopic dermatitis (AD). We evaluated the association between solar ultraviolet radiation (UVR) exposure and AD symptoms in children. Eighty-two children under 6 years (48 boys and 34 girls) with AD living in Seoul, Korea, were enrolled and followed for 12 months between September 2013 and August 2014. Daily symptoms were recorded to describe the degree of itching, sleep disturbance, erythema, dryness, oozing, and edema. We assessed solar UVR by measuring radiation heat flux over the 290-400 nm wavelength range using thermopiles. A generalized linear mixed model and a generalized additive mixed model were used to evaluate the effects of UVR exposure on AD symptoms after adjusting for age, sex, outdoor temperature, outdoor humidity, and ambient air pollution. Symptom records of 12 915 person-days were analyzed. UVR showed a significantly positive relationship with AD symptoms. Over the study period, an increase in UVR by 10 W/cm 2 was associated with a 1.46% increase in AD symptoms (95% CI: 0.85-2.07) on the exposure day. An increase in the 6-day average level of UVR of the previous 5 days and the current day by 10 W/cm 2 was associated with a 3.58% (95% CI: 2.60-4.56) increase in AD symptoms. UVR exposure significantly increased AD symptoms in autumn, but decreased them in winter. Atopic dermatitis symptoms in children are likely to be affected by exposure to solar UVR with a cumulative effect, and this effect is different according to season. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Ultraviolet radiation, measurements and safety evaluations for radiation protection purposes

International Nuclear Information System (INIS)

Witew, B.; Fischer, P.G.

1983-01-01

In order to evaluate the effects of ultraviolet radiation, one has to study that photobiologically effective radiation which induces a just measurable threshold reaction. For practical radiation protection, one has to determine the permissible duration of exposure at the end of which the threshold reaction is induced. This time limit is derived by means of spectral measurements and determination of radiation intensity. Detrimental photobiological effects can be avoided, and favourable effects optimized, by observing the time limit. Thus these measurements are used to determine the threshold at which the desired effects of ultraviolet radiation will be accompanied by unwanted effects or damage to persons, as for instance in the use of ultraviolet radiation for operating room sterilization, arc welding work, or cosmetic purposes. (orig.) [de

Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study using data from the 2007 to 2009 Canadian Health Measures Survey.

Science.gov (United States)

Greenfield, Jamie A; Park, Philip S; Farahani, Ellie; Malik, Suneil; Vieth, Reinhold; McFarlane, Norman A; Shepherd, Theodore G; Knight, Julia A

2012-08-15

Exposure to solar ultraviolet-B (UV-B) radiation is a major source of vitamin D3. Chemistry climate models project decreases in ground-level solar erythemal UV over the current century. It is unclear what impact this will have on vitamin D status at the population level. The purpose of this study was to measure the association between ground-level solar UV-B and serum concentrations of 25-hydroxyvitamin D (25(OH)D) using a secondary analysis of the 2007 to 2009 Canadian Health Measures Survey (CHMS). Blood samples collected from individuals aged 12 to 79 years sampled across Canada were analyzed for 25(OH)D (n = 4,398). Solar UV-B irradiance was calculated for the 15 CHMS collection sites using the Tropospheric Ultraviolet and Visible Radiation Model. Multivariable linear regression was used to evaluate the association between 25(OH)D and solar UV-B adjusted for other predictors and to explore effect modification. Cumulative solar UV-B irradiance averaged over 91 days (91-day UV-B) prior to blood draw correlated significantly with 25(OH)D. Independent of other predictors, a 1 kJ/m² increase in 91-day UV-B was associated with a significant 0.5 nmol/L (95% CI 0.3-0.8) increase in mean 25(OH)D (P = 0.0001). The relationship was stronger among younger individuals and those spending more time outdoors. Based on current projections of decreases in ground-level solar UV-B, we predict less than a 1 nmol/L decrease in mean 25(OH)D for the population. In Canada, cumulative exposure to ambient solar UV-B has a small but significant association with 25(OH)D concentrations. Public health messages to improve vitamin D status should target safe sun exposure with sunscreen use, and also enhanced dietary and supplemental intake and maintenance of a healthy body weight.

SimUVEx v2 : a numeric tool to predict anatomical solar ultraviolet exposure

OpenAIRE

Religi, Arianna; Moccozet, Laurent; Farahmand, Meghdad; Vuilleumier, L.aurent; Vernez, David; Milon, Antoine; Backes, Claudine; Bulliard, Jean-Luc

2016-01-01

Solar ultraviolet (UV) radiation has a dual effect on human health: low UV doses promote the photosynthesis of vitamin D and regulate calcium and phosphorus metabolism, while an excessive UV exposure is the main cause of skin cancer, along with eye diseases and premature skin ageing. The link between UV radiation levels and UV exposure is not fully understood since exposure data are limited and individual anatomical variations in UV doses are significant. SimUVEx is a numeric simulation tool ...

Solar Ultraviolet Radiation Exposure of South African Marathon Runners During Competition Marathon Runs and Training Sessions: A Feasibility Study.

Science.gov (United States)

Nurse, Victoria; Wright, Caradee Y; Allen, Martin; McKenzie, Richard L

2015-01-01

Marathon runners spend considerable time in outdoor training for and participating in marathons. Outdoor runners may experience high solar ultraviolet radiation (UVR) exposure. South Africa, where running is popular, experiences high ambient solar UVR levels that may be associated with adverse health effects. This feasibility study explores the use of personal dosimeters to determine solar UVR exposure patterns and possible related acute health risks of four marathon runners during marathons and training sessions in Cape Town and Pretoria. Runners running marathons that started early in the day, and that did not exceed 4 hours, yielded low total solar UVR exposure doses (mean 0.093 SED per exposure period run, median 0.088 SED, range 0.062-0.136 SED; average of 16.54% of ambient solar UVR). Training sessions run during early morning and late afternoon presented similar results. Several challenges hindered analysis including accounting for anatomical position of personal dosimeter and natural shade. To assess health risks, hazard quotients (HQs) were calculated using a hypothetical runner's schedule. Cumulative, annual solar UVR exposure-calculated acute health risks were low (HQ = 0.024) for training sessions and moderate (HQ = 4.922) for marathon runs. While these data and calculations are based on 18 person-days, one can measure marathon runners' personal solar UVR exposure although several challenges must be overcome. © 2015 The American Society of Photobiology.

Ambient solar UV radiation and seasonal trends in potential sunburn ...

African Journals Online (AJOL)

Background. The detrimental effects of excess personal solar ultraviolet (UV) radiation exposure include sunburn, immunosuppression and skin cancer. In South Africa, individuals with minimum natural protection from melanin, including fair-skinned individuals and African albinos, and people spending extended ...

Thermoluminescent monitoring of the solar ultraviolet radiation with KCl: Eu{sup 2+} crystals; Monitoreo termoluminiscente de la radiacion solar ultravioleta con cristales de KCl: Eu{sup 2+}

Energy Technology Data Exchange (ETDEWEB)

Chernov, V.; Melendrez, R.; Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A.P. 5-88, Hermosillo, Sonora (Mexico)

2000-07-01

In this work it has been investigating the Tl properties of KCl: Eu{sup 2+} subjected to solar direct radiation. Also it was realized irradiation with the Deuterium and Xenon lamps. It was used a set of filters and a Katos monochromator 0.25 M to determine the spectral response to Tl peaks and a study of them with respect to the duration of the Sun irradiation. After of the Sun irradiation the Tl curves show several peaks between the ambient temperature and 673 K. The relation between peaks depends strongly of the irradiation time and the different solar light wavelength. It is possible to divide the Tl peaks in two groups. The first one (T<473 K) is very sensitive to ultraviolet radiation but it is strongly affected by visible light. The second one (T>473 K) is not too sensitive but is more stable under optical whitening. Here the obtained results are discussed with respect to UV dosemeters development for environment which facilitate to obtain direct measurements of the UV index. (Author)

[Analysis of the cumulative solar ultraviolet radiation in Mexico].

Science.gov (United States)

Castanedo-Cázares, Juan Pablo; Torres-Álvarez, Bertha; Portales-González, Bárbara; Martínez-Rosales, Karla; Hernández-Blanco, Diana

2016-01-01

The incidence of skin cancer has increased in Mexico in recent years. Ultraviolet radiation is the main risk factor associated. Due to the need to develop strategies to prevent skin cancer, the aim of the study was to estimate the UV intensity in several representative regions of Mexico, the average annual UV dose of these populations, and the potential benefit of applying sunscreen at different ages. The intensity of UV radiation was quantified by remote and terrestrial radiometry. The dose of UV exposure was measured in minimal erythema doses using validated models for face and arms. The benefit of using a sunscreen was calculated with the use of a sunscreen with SPF 15 from birth to age 70. The UV radiation is lower in December and greater in the period from May to July. The region with a lower annual dose is Tijuana; and the higher annual dose is in the Mexico City area. The annual difference between these regions was 58 %. Through life, a low SPF sunscreen can reduce up to 66 % of the received UV dose. The geographical location is a risk factor for accumulation of UV radiation in Mexico. Since childhood, people receive high amounts of it; however, most of this dose can be reduced using any commercially available sunscreen, if applied strategically.

Ion beam sputtered aluminum based multilayer mirrors for extreme ultraviolet solar imaging

Energy Technology Data Exchange (ETDEWEB)

Ziani, A. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Centre National d’Etudes Spatiales (CNES), 18 Avenue E. Belin, 31401 Toulouse (France); Delmotte, F., E-mail: Franck.Delmotte@InstitutOptique.fr [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Le Paven-Thivet, C. [Institut d' Electronique et de Télécommunications de Rennes (IETR) UMR-CNRS 6164, Université de Rennes 1, UEB, IUT Saint Brieuc, 18 rue Henri Wallon, 22004 Saint Brieuc cedex France (France); Meltchakov, E.; Jérome, A. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Roulliay, M. [Institut des Sciences Moléculaires d’Orsay UMR 8214, Univ Paris Sud, 91405 Orsay France (France); Bridou, F. [Laboratoire Charles Fabry, Institut d' Optique, CNRS, Univ Paris Sud, 2 Avenue Augustin Fresnel, 91127 Palaiseau cedex France (France); Gasc, K. [Centre National d’Etudes Spatiales (CNES), 18 Avenue E. Belin, 31401 Toulouse (France)

2014-02-03

In this paper, we report on the design, synthesis and characterization of extreme ultraviolet interferential mirrors for solar imaging applications in the spectral range 17 nm–34 nm. This research is carried out in the context of the preparation of the European Space Agency Solar Orbiter mission. The purpose of this study consists in optimizing the deposition of Al-based multilayers by ion beam sputtering according to several parameters such as the ion beam current and the sputtering angle. After optimization of Al thin films, several kinds of Al-based multilayer mirrors have been compared. We have deposited and characterized bi-material and also tri-material periodic multilayers: aluminum/molybdenum [Al/Mo], aluminum/molybdenum/boron carbide [Al/Mo/B{sub 4}C] and aluminum/molybdenum/silicon carbide [Al/Mo/SiC]. Best experimental results have been obtained on Al/Mo/SiC samples: we have measured reflectivity up to 48% at 17.3 nm and 27.5% at 28.2 nm on a synchrotron radiation source. - Highlights: • Design and synthesis of extreme ultraviolet interferential mirrors. • Optimization of aluminum thin films by adjusting several deposition parameters. • Comparison of results obtained with different types of Al-based multilayer mirrors. • Reflectivity up to 48% at 17.3 nm on a synchrotron radiation source.

Ion beam sputtered aluminum based multilayer mirrors for extreme ultraviolet solar imaging

International Nuclear Information System (INIS)

Ziani, A.; Delmotte, F.; Le Paven-Thivet, C.; Meltchakov, E.; Jérome, A.; Roulliay, M.; Bridou, F.; Gasc, K.

2014-01-01

In this paper, we report on the design, synthesis and characterization of extreme ultraviolet interferential mirrors for solar imaging applications in the spectral range 17 nm–34 nm. This research is carried out in the context of the preparation of the European Space Agency Solar Orbiter mission. The purpose of this study consists in optimizing the deposition of Al-based multilayers by ion beam sputtering according to several parameters such as the ion beam current and the sputtering angle. After optimization of Al thin films, several kinds of Al-based multilayer mirrors have been compared. We have deposited and characterized bi-material and also tri-material periodic multilayers: aluminum/molybdenum [Al/Mo], aluminum/molybdenum/boron carbide [Al/Mo/B 4 C] and aluminum/molybdenum/silicon carbide [Al/Mo/SiC]. Best experimental results have been obtained on Al/Mo/SiC samples: we have measured reflectivity up to 48% at 17.3 nm and 27.5% at 28.2 nm on a synchrotron radiation source. - Highlights: • Design and synthesis of extreme ultraviolet interferential mirrors. • Optimization of aluminum thin films by adjusting several deposition parameters. • Comparison of results obtained with different types of Al-based multilayer mirrors. • Reflectivity up to 48% at 17.3 nm on a synchrotron radiation source

Ultraviolet radiation and immunosuppression.

LENUS (Irish Health Repository)

Murphy, G M

2009-11-01

Ultraviolet (UV) radiation is a complete carcinogen. The effects of UV radiation are mediated via direct damage to cellular DNA in the skin and suppression of image surveillance mechanisms. In the context of organ transplantation, addiction of drugs which suppress the immune system add greatly to the carcinogenicity of UV radiation. This review considers the mechanisms of such effects.

Solar Radiation effect on the bituminous binder

International Nuclear Information System (INIS)

Tadeo Rico, A.; Torres Perez, A.

2010-01-01

Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

Cutaneous solar ultraviolet exposure and clinical aspects of photodamage

Directory of Open Access Journals (Sweden)

Claire Battie

2012-01-01

Full Text Available Solar ultraviolet (UV radiation reaching the earth is a combination of UVB (290-320 nm and UVA (320-400 nm wavelengths. Since UVA is less energetic than UVB, UVB has long been thought to be the factor responsible for the damaging effects of solar radiation. But with modern tools such as in vitro models, it has been proven that UVA plays a major role. The objective of this review is to show how skin may be exposed to UV light and to highlight the clinical aspects of UV-induced skin damages with the respective contribution of UVB or UVA. Even if UVA is less energetic than UVB, it is more abundant and penetrates deeper into the skin, reaching as far as the dermis. Various factors also influence skin exposure to UV light: the latitude, season, and time of the day. Acute as well as chronic sun exposure induces short- and long-term clinical damages. Erythema and pigmentation are immediate responses of normal human skin exposed to UV radiation. The long-term effects are photoaging and photocarcinogenesis. In particular, UVA appears to play a major role in the deterioration of dermal structure leading to the photoaged appearance of the skin.

Exposure of Finnish population to ultraviolet radiation and radiation measurements

International Nuclear Information System (INIS)

Hoikkala, M.; Lappalainen, J.; Leszczynski, K.; Paile, W.

1990-01-01

This report is based on a survey of the literature on radiation risks involved in sunbathing and the use of solaria. The purpose of the report is to provide background information for the development of regulations on solaria and for informing the public about the risks posed by solaria and the sun. The report gives an overview of the properties and biological effects of ultraviolet radiation. The most important regulations and recommendations issued in various countries are presented. The connection between ultraviolet radiation and the risks of skin cancer is examined both on a general level and in reference to information obtained from the Finnish Cancer Registry. In Finland, the incidence of melanomas nearly tripled between 1960 and 1980. The most important cause is considered to be the population's increased exposure to the su's ultraviolet radiation. There are no reliable data on the connection between the use of solaria and the risks of skin cancer. It is estimated, however, that solaria account for less than 10 per cent of the skin cancer risk of the whole population. There are some difficult physical problems associated with the measurement of ultraviolet radiation emitted by both natural sources and solaria. A preliminary study of these problems has been undertaken by means of a survey of the available literature, supplemented by a review of measurements performed by the Finnish Centre For Radiation and Nuclear Safety. The estimated inaccuracy of the Optronic 742 spectroradiometer used by the Centre in the measurement of ultraviolet radiation emitted by the sun and solaria is about +-14%

Measuring solar UV radiation with EBT radiochromic film

International Nuclear Information System (INIS)

Butson, Ethan T; Cheung Tsang; Yu, Peter K N; Butson, Martin J

2010-01-01

Ultraviolet radiation dosimetry has been performed with the use of a radiochromic film dosimeter called Gafchromic EBT for solar radiation exposure. The film changes from a clear colour to blue colour when exposed to ultraviolet radiation and results have shown that the colour change is reproducible within ±10% at 5 kJ m -2 UV exposure under various conditions of solar radiation. Parameters tested included changes in season (summer versus winter exposure), time of day, as well as sky conditions such as cloudy skies versus clear skies. As the radiochromic films' permanent colour change occurs in the visible wavelengths the film can be analysed with a desktop scanner with the most sensitive channel for analysis being the red component of the signal. Results showed that an exposure of 5 kJ m -2 (approximately 1 h exposure in full sun during summer) produced an approximate 0.28 change in the net OD when analysed in reflection mode on the desktop scanner which is significant darkening. The main advantages of this film type, and thus the new EBT2 film which has replaced EBT for measurement of UV exposure, is the visible colour change and thus easy analysis using a desktop scanner, its uniformity in response and its robust physical strength for use in outside exposure situations. (note)

A broad-spectrum sunscreen prevents cumulative damage from repeated exposure to sub-erythemal solar ultraviolet radiation representative of temperate latitudes.

Science.gov (United States)

Seité, S; Christiaens, F; Bredoux, C; Compan, D; Zucchi, H; Lombard, D; Fourtanier, A; Young, A R

2010-02-01

We have previously shown the detrimental effects of 19 sub-erythemal exposures to daily ultraviolet radiation (DUVR, which mimics non-extreme exposure conditions), delivered over 4 weeks to volunteers. This source had UVA (320-400 nm) to UVB (290-320 nm) irradiance ratio of 25, instead of that close to 10 that is typically the case with solar-simulated radiation (SSR) that represents summer global sunlight with a clear sky and quasi-zenith solar irradiance. Here, we report on an extension of this previous study, in which we evaluated the photoprotection afforded by a broad-spectrum daily-care product with a low-sun protection factor (SPF 8, UVA-PF 7 and 3* rated UVA protection). We assessed cellular and molecular markers of photodamage that are relevant to skin cancer and photoageing. This study shows that biological effects of repeated exposure to DUVR can be prevented by a broad-spectrum daily-care product and that the level of protection afforded varies with the studied endpoint. Efficient daily UVR protection, as provided by a broad-spectrum daily-care product, is necessary to prevent the 'silent' sub-erythemal cumulative effects of UVR from inadvertent sun exposure.

Pairing of near-ultraviolet solar cells with electrochromic windows for smart management of the solar spectrum

Science.gov (United States)

Davy, Nicholas C.; Sezen-Edmonds, Melda; Gao, Jia; Lin, Xin; Liu, Amy; Yao, Nan; Kahn, Antoine; Loo, Yueh-Lin

2017-08-01

Current smart window technologies offer dynamic control of the optical transmission of the visible and near-infrared portions of the solar spectrum to reduce lighting, heating and cooling needs in buildings and to improve occupant comfort. Solar cells harvesting near-ultraviolet photons could satisfy the unmet need of powering such smart windows over the same spatial footprint without competing for visible or infrared photons, and without the same aesthetic and design constraints. Here, we report organic single-junction solar cells that selectively harvest near-ultraviolet photons, produce open-circuit voltages eclipsing 1.6 V and exhibit scalability in power generation, with active layers (10 cm2) substantially larger than those typical of demonstration organic solar cells (0.04-0.2 cm2). Integration of these solar cells with a low-cost, polymer-based electrochromic window enables intelligent management of the solar spectrum, with near-ultraviolet photons powering the regulation of visible and near-infrared photons for natural lighting and heating purposes.

Ultraviolet radiation monitoring in makkah city, Saudi Arabia, using thermoluminescence material CaF2:Tm

International Nuclear Information System (INIS)

Al-Ghorabie, F.H.; Natto, S.S.; AL-Lehyani, S.A.

2005-01-01

The aim of the present study is to explore the possibility of using Ca F2:Tm thermoluminescence material for measuring and monitoring of solar UV R in Makkah City, Saudi Arabia. Several laboratory experiments, prior to the field measurements, were performed included study of the effects of ultraviolet wavelengths on the response of the phosphor, study of the effect of increasing ultraviolet radiation dose on the intensity of thermoluminescence and study the effect of time factor on the thermoluminescence fading of Ca F 2 :Tm. The phosphor was then exposed directly for one hour to sunlight radiation on a daily basis for 90 days in an open field inside Umm Al-Qura university campus. The field measurements were performed during the months of June, July and August 2003 at 1:00 p.m. The laboratory and field results of this study showed that Ca F 2 :Tm can be used as a suitable dosimeter for solar UV R

Ultraviolet-B radiation effects on leaf fluorescence characteristics in cultivars of soybean

International Nuclear Information System (INIS)

Miles, D.

1993-01-01

Ultraviolet-B (UV-B; 280–320 nm)–emitting lamps unavoidably emit ultraviolet-A (UV-A; 320–400 nm) and ultraviolet-C (UV-C; <280 nm) radiation. Short-wavelength–blocking filters are generally used to limit the wave bands of UV under investigation. The widespread use of such filters means that all exposures to UV-B radiation will have a significant UV-A component. Therefore, the physiological effects unique to UV-B exposure are difficult to clearly isolate. This study presents a method to remove the UV-A and UV-C “contamination” using a liquid potassium chromate (K 2 CrO 4 ) filter, thus allowing more direct assessment of the effects of UV-B exposure. Cultures of the green marine alga Dunaliella tertiolecta were grown in the absence of UV radiation. Sunlamps supplied the UV radiation for a 24 h exposure (solar radiation was not used in this study). The UV radiation was filtered either by the standard method (i.e. cellulose acetate (CA) with polyester = Mylar controls) or by a liquid filter of potassium chromate. Photosynthetic responses were compared. Major decreases in the ratio of variable to maximal fluorescence in dark-adapted cells and photosynthetic capacity were observed in CA-filtered cultures, whereas no change was observed in cells exposed to the same UV-B flux with the UV-A removed by K 2 CrO 4 . The use of a CA filter with a Mylar control does not link results unequivocally to UV-B radiation. Such results should be interpreted with caution. (author)

Prediction of shock-layer ultraviolet radiation for hypersonic vehicles in near space

Directory of Open Access Journals (Sweden)

Niu Qinglin

2016-10-01

Full Text Available A systemic and validated model was developed to predict ultraviolet spectra features from the shock layer of near-space hypersonic vehicles in the “solar blind” band region. Computational procedures were performed with 7-species thermal non-equilibrium fluid mechanics, finite rate chemistry, and radiation calculations. The thermal non-equilibrium flow field was calculated with a two-temperature model by the finite volume technique and verified against the bow-shock ultra-violet (BSUV flight experiments. The absorption coefficient of the mixture gases was evaluated with a line-by-line method and validated through laboratory shock tube measurements. Using the line of sight (LOS method, radiation was calculated from three BSUV flights at altitudes of 38, 53.5 and 71 km. The investigation focused on the level and structure of ultraviolet spectra radiated from a NO band system in wavelengths of 200–400 nm. Results predicted by the current model show qualitative spatial agreement with the measured data. At a velocity of 3.5 km/s (about Mach 11, the peak absolute intensity at an altitude of 38 km is two orders of magnitude higher than that at 53.5 km. Under the same flight conditions, the spectra structures have quite a similar distribution at different viewing angles. The present computational model performs well in the prediction of the ultraviolet spectra emitted from the shock layer and will contribute to the investigation and analysis of radiative features of hypersonic vehicles in near space.

Photoprotection beyond ultraviolet radiation--effective sun protection has to include protection against infrared A radiation-induced skin damage.

Science.gov (United States)

Schroeder, P; Calles, C; Benesova, T; Macaluso, F; Krutmann, J

2010-01-01

Solar radiation is well known to damage human skin, for example by causing premature skin ageing (i.e. photoageing). We have recently learned that this damage does not result from ultraviolet (UV) radiation alone, but also from longer wavelengths, in particular near-infrared radiation (IRA radiation, 760-1,440 nm). IRA radiation accounts for more than one third of the solar energy that reaches human skin. While infrared radiation of longer wavelengths (IRB and IRC) does not penetrate deeply into the skin, more than 65% of the shorter wavelength (IRA) reaches the dermis. IRA radiation has been demonstrated to alter the collagen equilibrium of the dermal extracellular matrix in at least two ways: (a) by leading to an increased expression of the collagen-degrading enzyme matrix metalloproteinase 1, and (b) by decreasing the de novo synthesis of the collagen itself. IRA radiation exposure therefore induces similar biological effects to UV radiation, but the underlying mechanisms are substantially different, specifically, the cellular response to IRA irradiation involves the mitochondrial electron transport chain. Effective sun protection requires specific strategies to prevent IRA radiation-induced skin damage. 2010 S. Karger AG, Basel.

Ocean acidification alters the photosynthetic responses of a coccolithophorid to fluctuating ultraviolet and visible radiation.

Science.gov (United States)

Jin, Peng; Gao, Kunshan; Villafañe, Virginia E; Campbell, Douglas A; Helbling, E Walter

2013-08-01

Mixing of seawater subjects phytoplankton to fluctuations in photosynthetically active radiation (400-700 nm) and ultraviolet radiation (UVR; 280-400 nm). These irradiance fluctuations are now superimposed upon ocean acidification and thinning of the upper mixing layer through stratification, which alters mixing regimes. Therefore, we examined the photosynthetic carbon fixation and photochemical performance of a coccolithophore, Gephyrocapsa oceanica, grown under high, future (1,000 μatm) and low, current (390 μatm) CO₂ levels, under regimes of fluctuating irradiances with or without UVR. Under both CO₂ levels, fluctuating irradiances, as compared with constant irradiance, led to lower nonphotochemical quenching and less UVR-induced inhibition of carbon fixation and photosystem II electron transport. The cells grown under high CO₂ showed a lower photosynthetic carbon fixation rate but lower nonphotochemical quenching and less ultraviolet B (280-315 nm)-induced inhibition. Ultraviolet A (315-400 nm) led to less enhancement of the photosynthetic carbon fixation in the high-CO₂-grown cells under fluctuating irradiance. Our data suggest that ocean acidification and fast mixing or fluctuation of solar radiation will act synergistically to lower carbon fixation by G. oceanica, although ocean acidification may decrease ultraviolet B-related photochemical inhibition.

Ultraviolet radiation, cancer of the skin and immunology

International Nuclear Information System (INIS)

Suurmond, D.

1984-01-01

The effects of near and far ultraviolet radiation on the development of skin neoplasms are reviewed. Especially the role of ultraviolet radiation in immunosuppression is discussed as a possible working mechanism of the tumor promoting the effect of this radiation, beside effects on DNA-repair. (Auth.)

Infrared radiation increases skin damage induced by other wavelengths in solar urticaria.

Science.gov (United States)

de Gálvez, María Victoria; Aguilera, José; Sánchez-Roldán, Cristina; Herrera-Ceballos, Enrique

2016-09-01

Photodermatoses are typically investigated by analyzing the individual or combined effects of ultraviolet A (UVA), ultraviolet B (UVB), and visible light using light sources that simulate portions of the solar spectrum. Infrared radiation (IRR), however, accounts for 53% of incident solar radiation, but its effects are not taken into account in standard phototest protocols. The aim was to analyze the effects of IRR, alone and combined with UVA and visible light on solar urticaria lesions, with a distinction between infrared A (IRA) and infrared B (IRB). We performed standard phototests with UVA and visible light in four patients with solar urticaria and also tested the effects after blocking IRB with a water filter. To analyze the direct effect of IRR, we performed phototests with IRA and IRB. Initial standard phototests that were all positive found the induction of erythema and whealing, while when IRR was blocked from the UVA and visible light sources, three of the patients developed no lesions, while the fourth developed a very small wheal. These results suggest that IRR has the potential to produce and exacerbate lesions caused by other types of radiation. Consideration of these effects during phototesting could help prevent diagnostic errors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Short and long term variation in ultraviolet radiation and multiple sclerosis

DEFF Research Database (Denmark)

Menni, Cristina; Lowell, Walter E; Bentzen, Joan

2012-01-01

We examined the role of ultraviolet radiation (UVR) in persons diagnosed with multiple sclerosis (MS) in four different populations, Italians, Danish, White and African Americans. We tested whether variation in UVR as determined by seasons (short term variation) and solar cycles (long term...... to study the pattern of month of birth distribution in patients with MS comparing with general population data. T-tests were employed to study solar cycles association with lifespan. A surplus of births was observed in June for White Americans. A decrease of births in October and November, though...... not significant after multiple testing correction, was observed in the three populations. In White American with MS overall, males and females, we found that solar cycle is associated with lifespan. We found that season and solar cycles have some role in MS susceptibility and life duration. However...

The effects of solar ultraviolet-B radiation on the growth and yield of barley are accompanied by increased DNA damage and antioxidant responses

International Nuclear Information System (INIS)

Mazza, C.A.; Battista, D.; Zima, A.M.; Szwarcberg-Bracchitta, M.; Giordano, C.V.; Acevedo, A.; Scopel, A.L.; Ballare, C.L.

1999-01-01

There is limited information on the impacts of present-day solar ultraviolet-B radiation (UV-B) on biomass and grain yield of field crops and on the mechanisms that confer tolerance to UV-B radiation under field conditions. We investigated the effects of solar UV-B on aspects of the biochemistry, growth and yield of barley crops using replicated field plots and two barley strains, a catalase (CAT)-deficient mutant (RPr 79/4) and its wild-type mother line (Maris Mink). Solar UV-B reduced biomass accumulation and grain yield in both strains. The effects on crop biomass accumulation tended to be more severe in RPr 79/4 (≈ 32% reduction) than in the mother line (≈ 20% reduction). Solar UV-B caused measurable DNA damage in leaf tissue, in spite of inducing a significant increase in UV-absorbing sunscreens in the two lines. Maris Mink responded to solar UV-B with increased CAT and ascorbate peroxidase (APx) activity. No effects of UV-B on total superoxide dismutase (SOD) activity were detected. Compared with the wild type, RPr 79/4 had lower CAT activity, as expected, but higher APx activity. Neither of these activities increased in response to UV-B in RPr 79/4. These results suggest that growth inhibition by solar UV-B involves DNA damage and oxidative stress, and that constitutive and UV-B-induced antioxidant capacity may play an important role in UV-B tolerance. (author)

Stratospheric ozone, ultraviolet radiation and climate change

International Nuclear Information System (INIS)

Boucher, O.

2008-01-01

It is well known that an overexposure to ultraviolet radiation is associated with a number of health risks such as an increased risk of cataracts and skin cancers. At a time when climate change is often blamed for all our environmental problems, what is the latest news about the stratospheric ozone layer and other factors controlling ultraviolet radiation at the surface of the Earth? Will the expected changes in the chemical composition of the atmosphere and changes in our climate increase or decrease the risk for skin cancer? This article investigates the role of the various factors influencing ultraviolet radiation and presents the latest knowledge on the subject. (author)

Applying spaceborne reflectivity measurements for calculation of the solar ultraviolet radiation at ground level

Directory of Open Access Journals (Sweden)

P. N. den Outer

2012-12-01

Full Text Available Long-term analysis of cloud effects on ultraviolet (UV radiation on the ground using spaceborne observations requires the use of instruments that have operated consecutively. The longest data record can be built from the reflectivity measurements produced by the instruments Total Ozone Mapping Spectrometers (TOMS flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI flown on EOS Aura since 2004. The reflectivity data produced by TOMS on Earth Probe is only included until 2002. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing the standard reflectivity are compared with measurements of UV irradiances at eight European low-elevation stations. The reflectivity data of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage, i.e. 2–3%. In contrast, the reflectivity product of OMI requires correction of 7–10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The average reduction of UV radiation due to clouds for all sites together indicates a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of the reflectivity data would have indicated the opposite.

An optimal area was established for reflectivity data for the calculation of daily sums of UV radiation. It measures approximately 1.25° in latitudinal direction for square-shaped areas overhead the ground-based UV stations. Such an area can be traversed within 5 to 7 h at the average wind speeds found for the West European continent.

Terrestrial ecosystems, increased solar ultraviolet radiation, and interactions with other climate change factors.

Science.gov (United States)

Caldwell, M M; Bornman, J F; Ballaré, C L; Flint, S D; Kulandaivelu, G

2007-03-01

as growth, DNA damage, oxidative damage and induction of changes in secondary chemicals. Thus, use of a single BSWF for plant or ecosystem response is not appropriate. This brief review emphasizes progress since the previous report toward the understanding of solar ultraviolet radiation effects on terrestrial systems as it relates to ozone column reduction and the interaction of climate change factors.

Characterization of a smartphone camera's response to ultraviolet A radiation.

Science.gov (United States)

Igoe, Damien; Parisi, Alfio; Carter, Brad

2013-01-01

As part of a wider study into the use of smartphones as solar ultraviolet radiation monitors, this article characterizes the ultraviolet A (UVA; 320-400 nm) response of a consumer complementary metal oxide semiconductor (CMOS)-based smartphone image sensor in a controlled laboratory environment. The CMOS image sensor in the camera possesses inherent sensitivity to UVA, and despite the attenuation due to the lens and neutral density and wavelength-specific bandpass filters, the measured relative UVA irradiances relative to the incident irradiances range from 0.0065% at 380 nm to 0.0051% at 340 nm. In addition, the sensor demonstrates a predictable response to low-intensity discrete UVA stimuli that can be modelled using the ratio of recorded digital values to the incident UVA irradiance for a given automatic exposure time, and resulting in measurement errors that are typically less than 5%. Our results support the idea that smartphones can be used for scientific monitoring of UVA radiation. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Impact of ultraviolet radiation on humans

International Nuclear Information System (INIS)

Cesarini, J.P.

2001-01-01

Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

Impact of ultraviolet radiation on humans

Energy Technology Data Exchange (ETDEWEB)

Cesarini, J.P. [Laboratoire de Recherche sur les Tumeurs de la Peau Humaine, INSERM, Paris (France)

2001-07-01

Solar radiation, including its ultraviolet (UV) components is a key factor in life on Earth. While small quantities of UV are beneficial for people (for example, through the production of vitamin D), the considerable amount to which people sometimes expose themselves may have extremely noxious effects including actinic erythema, sunburn, photo-induced diseases, photo-worsened diseases, actinic ageing and skin cancers. Since the last century, human exposure to UV has increased either by social-behaviour modifications, or by anthropogenic disruption to the environment through, among other things, industrial development. The World Health Organisation's (WHO) INTERSUN programme has several components: action for reconstruction of the ozone layer through, for example, preventing dumping of chlorofluorocarbons; creation and popularisation of a global UV index; prevention campaigns underlining the risks from UV exposure including dissemination of information to daily newspapers. These are all aimed at reducing the amount of UV radiation that people receive. In addition the WHO advises against exposure to UV artificial sources to reduce overall the quantity of UV received. (author)

The impact of solar ultraviolet radiation on human health in sub-Saharan Africa

Directory of Open Access Journals (Sweden)

Caradee Y. Wright

2012-10-01

Full Text Available Photoprotection messages and ‘SunSmart’ programmes exist mainly to prevent skin cancers and, more recently, to encourage adequate personal sun exposure to elicit a vitamin D response for healthy bone and immune systems. Several developed countries maintain intensive research networks and monitor solar UV radiation to support awareness campaigns and intervention development. The situation is different in sub-Saharan Africa. Adequate empirical evidence of the impact of solar UV radiation on human health, even for melanomas and cataracts, is lacking, and is overshadowed by other factors such as communicable diseases, especially HIV, AIDS and tuberculosis. In addition, the established photoprotection messages used in developed countries have been adopted and implemented in a limited number of sub-Saharan countries but with minimal understanding of local conditions and behaviours. In this review, we consider the current evidence for sun-related effects on human health in sub-Saharan Africa, summarise published research and identify key issues. Data on the prevalence of human diseases affected by solar UV radiation in all subpopulations are not generally available, financial support is insufficient and the infrastructure to address these and other related topics is inadequate. Despite these limitations, considerable progress may be made regarding the management of solar UV radiation related health outcomes in sub-Saharan Africa, provided researchers collaborate and resources are allocated appropriately.

Epidermal UV-A absorbance and whole-leaf flavonoid composition in pea respond more to solar blue light than to solar UV radiation.

Science.gov (United States)

Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J

2015-05-01

Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors. © 2014 John Wiley & Sons Ltd.

Some aspects of vacuum ultraviolet radiation physics

CERN Document Server

Damany, Nicole; Vodar, Boris

2013-01-01

Some Aspects of Vacuum Ultraviolet Radiation Physics presents some data on the state of research in vacuum ultraviolet radiation in association with areas of physics. Organized into four parts, this book begins by elucidating the optical properties of solids in the vacuum ultraviolet region (v.u.v.), particularly the specific methods of determination of optical constants in v.u.v., the properties of metals, and those of ionic insulators. Part II deals with molecular spectroscopy, with emphasis on the spectra of diatomic and simple polyatomic molecules, paraffins, and condensed phases. Part III

Solar maximum ultraviolet spectrometer and polarimeter

Science.gov (United States)

Tandberg-Hanssen, E.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Hyder, C. L.; Michalitsianos, A. G.; Shine, R. A.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.

1979-01-01

The objectives of the UVSP experiment are to study solar ultraviolet radiations, particularly from flares and active regions, and to measure constituents in the terrestrial atmosphere by the extinction of sunlight at satellite dawn and dusk. The instrument is designed to observe the Sun at a variety of spectral and spatial resolutions in the range from 1150 to 3600 A. A Gregorian telescope with effective focal length of 1.8 m is used to feed a 1 m Ebert-Fastie spectrometer. A polarimeter containing rotatable magnesium fluoride waveplates is included behind the spectrometer entrance slit and will allow all four Stokes parameters to be determined. Velocities on the Sun can also be measured. The instrument is controlled by a computer which can interact with the data stream to modify the observing program. The observing modes, including rasters, spectral scans, velocity measurements, and polarimetry, are also described along with plans for mission operations, data handling, and analysis of the observations.

Application of ultraviolet and infrared radiation in food

OpenAIRE

D Jafarpour; M Alizadeh; F Siamak

2018-01-01

BACKGROUND: There are many uses of radiation in the food industry. Radiation can be considered as one of the new processes and usage of it can offer new features of food. This process in most food doesn’t leave any physical or sensory changes. Therefore, in this review article, the application of ultraviolet and infrared radiation in food was studied. Methods: Search by the keywords “Ultraviolet Radiation Infrared Radiation Food” in databases Pubmed, Scopus and Web of Sci...

Calculating the diffuse solar radiation in regions without solar radiation measurements

International Nuclear Information System (INIS)

Li, Huashan; Bu, Xianbiao; Long, Zhen; Zhao, Liang; Ma, Weibin

2012-01-01

Correlations for calculating diffuse solar radiation can be classified into models with global solar radiation (H-based method) and without it (Non-H method). The objective of the present study is to compare the performance of H-based and Non-H methods for calculating the diffuse solar radiation in regions without solar radiation measurements. The comparison is carried out at eight meteorological stations in China focusing on the monthly average daily diffuse solar radiation. Based on statistical error tests, the results show that the Non-H method that includes other readily available meteorological elements gives better estimates. Therefore, it can be concluded that the Non-H method is more appropriate than the H-based one for calculating the diffuse solar radiation in regions without solar radiation measurements. -- Highlights: ► Methods for calculating diffuse solar radiation in regions without solar radiation measurements are investigated. ► Diffuse solar radiation models can be classified into two groups according to global solar radiation. ► Two approaches are compared at the eight meteorological stations in China. ► The method without global solar radiation is recommended.

Synchrotron Vacuum Ultraviolet Light and Soft X-Ray Radiation Effects on Aluminized Teflon FEP Investigated

Science.gov (United States)

Dever, Joyce A.; Townsend, Jacqueline A.; Gaier, James R.; Jalics, Alice I.

1999-01-01

Since the Hubble Space Telescope (HST) was deployed in low Earth orbit in April 1990, two servicing missions have been conducted to upgrade its scientific capabilities. Minor cracking of second-surface metalized Teflon FEP (DuPont; fluorinated ethylene propylene) surfaces from multilayer insulation (MLI) was first observed upon close examination of samples with high solar exposure retrieved during the first servicing mission, which was conducted 3.6 years after deployment. During the second HST servicing mission, 6.8 years after deployment, astronaut observations and photographic documentation revealed significant cracks in the Teflon FEP layer of the MLI on both the solar- and anti-solar-facing surfaces of the telescope. NASA Goddard Space Flight Center directed the efforts of the Hubble Space Telescope MLI Failure Review Board, whose goals included identifying the low-Earth-orbit environmental constituent(s) responsible for the cracking and embrittling of Teflon FEP which was observed during the second servicing mission. The NASA Lewis Research Center provided significant support to this effort. Because soft x-ray radiation from solar flares had been considered as a possible cause for the degradation of the mechanical properties of Teflon FEP (ref. 1), the effects of soft xray radiation and vacuum ultraviolet light on Teflon FEP were investigated. In this Lewisled effort, samples of Teflon FEP with a 100-nm layer of vapor-deposited aluminum (VDA) on the backside were exposed to synchrotron radiation of various vacuum ultraviolet and soft x-ray wavelengths between 18 nm (69 eV) and 0.65 nm (1900 eV). Synchrotron radiation exposures were conducted using the National Synchrotron Light Source at Brookhaven National Laboratory. Samples of FEP/VDA were exposed with the FEP surface facing the synchrotron beam. Doses and fluences were compared with those estimated for the 20-yr Hubble Space Telescope mission.

Both near ultraviolet radiation and the oxidizing agent hydrogen peroxide induce a 32-kDa stress protein in normal human skin fibroblasts

International Nuclear Information System (INIS)

Keyse, S.M.; Tyrrell, R.M.

1987-01-01

We have analyzed the pattern of protein synthesis in solar near ultraviolet (334 nm, 365 nm) and near visible (405 nm) irradiated normal human skin fibroblasts. Two hours after irradiation we find that one major stress protein of approximately 32 kDa is induced in irradiated cells. This protein is not induced by ultraviolet radiation at wavelengths shorter than 334 nm and is not inducible by heat shock treatment of these cells. Although sodium arsenite, diamide, and menadione all induced a 32-kDa protein, they also induced the major heat shock proteins. In contrast, the oxidizing agent, hydrogen peroxide, induced the low molecular weight stress protein without causing induction of the major heat shock proteins. A comparison of the 32-kDa proteins induced by sodium arsenite, H 2 O 2 , and solar near ultraviolet radiation using chemical peptide mapping shows that they are closely related. These results imply that the pathways for induction of the heat shock response and the 32-kDa protein are not identical and suggest that, at least in the case of radiation and treatment with H 2 O 2 , the 32-kDa protein might be induced in response to cellular oxidative stress. This conclusion is supported by the observation that depletion of endogenous cellular glutathione prior to solar near ultraviolet irradiation lowers the fluence threshold for induction of the 32-kDa stress protein

Occupational exposure to solar ultraviolet radiation and the risk of prostate cancer.

Science.gov (United States)

Peters, Cheryl E; Demers, Paul A; Kalia, Sunil; Hystad, Perry; Villeneuve, Paul J; Nicol, Anne-Marie; Kreiger, Nancy; Koehoorn, Mieke W

2016-11-01

Preventable risk factors for prostate cancer are poorly understood; sun exposure is a possible protective factor. The goal of this study was to investigate prostate cancer risk in outdoor workers, a population with high sun exposure. Prostate cancer cases and controls from a large study (conducted between 1994 and 1997) were used for this analysis. A job exposure matrix (JEM) was used to assign solar ultraviolet radiation (UVR) at work as moderate (2 to hours outside/day) or high (≥6 hours). Average daily satellite UV-B measures were linked to the latitude/longitude of the residences of each participant. Several other exposure metrics were also examined, including ever/never exposed and standard erythemal dose by years (SED×years). Logistic regression was used to evaluate the association between solar UVR exposure and the odds of prostate cancer. A total of 1638 cases and 1697 controls were included. Men of Indian and Asian descent had reduced odds of prostate cancer (ORs 0.17 (0.08 to 0.35) and 0.25 (0.15 to 0.41), respectively) compared with Caucasian men, as did single men (OR 0.76 (0.58 to 0.98)) compared with married men. Overall, no statistically significant associations were observed between sun exposure and prostate cancer with 1 exception. In the satellite-enhanced JEM that considered exposure in high category jobs only, prostate cancer odds in the highest quartile of cumulative exposure was decreased compared with unexposed men (OR 0.68 (0.51 to 0.92)). This study found limited evidence for an association with prostate cancer, with the exception of 1 statistically significant finding of a decreased risk among workers with the longest term and highest sun exposure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Effects of solar radiation on hair and photoprotection.

Science.gov (United States)

Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

2015-12-01

In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. Copyright © 2015 Elsevier B.V. All rights reserved.

Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America.

Science.gov (United States)

Corrêa, Marcelo de Paula

2015-01-01

The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-melanoma skin cancer and other diseases of the skin and eyes (harmful effect) diagnosed each year in Brazil. However, the lack of scientific knowledge on the UV-R in Brazil and South America leads to adoption of protective measures based on studies conducted in Europe and USA, where the amounts of UV-R available at surface and the sun-exposure habits and characteristics of the population are significantly different from those observed in Brazil. In order to circumvent this problem, the Brazilian Society of Dermatology recently published the Brazilian Consensus of Photoprotection based on recent studies performed locally. The main goal of this article is to provide detailed educational information on the main properties and characteristics of UV-R and UV index in a simple language. It also provides: a) a summary of UV-R measurements recently performed in Brazil; b) a comparison with those performed in Europe; and, c) an evaluation to further clarify the assessment of potential harm and health effects owing to chronic exposures.

Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America*

Science.gov (United States)

Corrêa, Marcelo de Paula

2015-01-01

The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-melanoma skin cancer and other diseases of the skin and eyes (harmful effect) diagnosed each year in Brazil. However, the lack of scientific knowledge on the UV-R in Brazil and South America leads to adoption of protective measures based on studies conducted in Europe and USA, where the amounts of UV-R available at surface and the sun-exposure habits and characteristics of the population are significantly different from those observed in Brazil. In order to circumvent this problem, the Brazilian Society of Dermatology recently published the Brazilian Consensus of Photoprotection based on recent studies performed locally. The main goal of this article is to provide detailed educational information on the main properties and characteristics of UV-R and UV index in a simple language. It also provides: a) a summary of UV-R measurements recently performed in Brazil; b) a comparison with those performed in Europe; and, c) an evaluation to further clarify the assessment of potential harm and health effects owing to chronic exposures. PMID:26131858

Solar ultraviolet radiation in Africa: a systematic review and critical evaluation of the health risks and use of photoprotection.

Science.gov (United States)

Lucas, Robyn M; Norval, Mary; Wright, Caradee Y

2016-01-01

Most information on the harmful health effects of solar ultraviolet radiation (UVR) has been obtained in populations in which the majority has fair skin. Here a systematic review of evidence on diseases related to solar UVR in Africa was undertaken, and the appropriateness of effective photoprotection for these people considered. There are few population-based studies on UV-induced skin cancers (melanoma, squamous and basal cell carcinomas) in Africa, although limited reports indicated that they occur, even in people with deeply pigmented skin. The incidence of melanoma is particularly high in the white population living in the Western Cape of South Africa and has increased significantly in recent years. Cataract is extremely common in people of all skin colours and is a frequent cause of blindness, particularly in the elderly. For both skin cancer and cataract, the proportion of the disease risk that is attributable to exposure to solar UVR in African populations, and therefore the health burden caused by UV irradiation is unclear. There was little published information on the use of sun protection in Africa. The potential disease burden attributable to solar UVR exposure of Africans is high, although accurate data to quantify this are sparse. Information is required on the incidence, prevalence and mortality for the range of UV-related diseases in different populations living throughout Africa. Photoprotection is clearly required, at least for those subpopulations at particularly high risk, but may be limited by cost and cultural acceptability.

Solar ultraviolet-B radiation affects seedling emergence, DNA integrity, plant morphology, growth rate, and attractiveness to herbivore insects in Datura ferox

International Nuclear Information System (INIS)

Ballare, C.L.; Scopel, A.L.; Stapleton, A.E.

1996-01-01

To study functional relationships between the effects of solar ultraviolet-B radiation (UV0B) on different aspects of the physiology of a wild plant, we carried out exclusion experiments in the field with the summer annual Datura ferrox L. Solar UV-B incident over Buenos Aires reduced daytime seedling emergence, inhibited stem elongation and leaf expansion, and tended to reduce biomass accumulation during early growth. However, UV-B had no effect on calculated net assimilation rate. Using a monoclonal antibody specific to the cyclobutane-pyrimidine dimer (CPD), we found that plants receiving full sunlight had more CPDs per unit of DNA than plants shielded from solar UV-B, but the positive correlation between UV-B and CPD burden tended to level off at high (near solar) UV-B levels. At our field site, Datura plants were consumed by leaf beetles (Coleoptera), and the proportion of plants attacked by insects declined with the amount of UV-B received during growth. Field experiments showed that plant exposure to solar UV-B reduced the likelihood of leaf beetle attack by one-half. Our results highlight the complexities associated with scaling plant responses to solar UV-B, because they show: (a) a lack of correspondence between UV-B effects on net assimilation rate and whole-plant growth rate, (b) nonlinear UV-B dose-response curves, and (c) UV-B effects of plant attractiveness to natural herbivores. 56 refs., 7 figs

Inhibition of seagrass photosynthesis by ultraviolet-B radiation

International Nuclear Information System (INIS)

Trocine, R.P.; Rice, J.D.; Wells, G.N.

1981-01-01

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme (Kuetz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated. Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species. Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation

Sunscreen protection against ultraviolet radiation-induced pyrimidine dimers in mouse epidermal DNA

International Nuclear Information System (INIS)

Ley, R.D.

1997-01-01

Solar ultraviolet radiation (UVR) induces a number of pathologic conditions of mammalian skin including erythema, oedema, hyperplasia, sunburn cell formation and skin cancer. Consequently, UVR-induced DNA damage has been implicated as one of the photochemical events that results in the formation of these pathological changes. The ability of sunscreens to protect against UVR-induced DNA damage has not been well characterized especially with UVA (320-400 nm) wavelengths and UVA absorbers. In this paper we present results of a study aimed at determining the efficacy of two sunscreens at preventing the induction of pyrmidine dimers in basal cell DNA of mice exposed to solar-simulated UVR (SSUV) wavelengths (290-400 nm) or to UVA (320-400 nm). (author)

Sunscreen protection against ultraviolet radiation-induced pyrimidine dimers in mouse epidermal DNA

Energy Technology Data Exchange (ETDEWEB)

Ley, R.D. [The Lovelace Institutes, Albuqeurque, NM (United States). Photomdecine Program; Fourtanier, A. [L`Oreal, Advanced Research, Clichy (France)

1997-06-01

Solar ultraviolet radiation (UVR) induces a number of pathologic conditions of mammalian skin including erythema, oedema, hyperplasia, sunburn cell formation and skin cancer. Consequently, UVR-induced DNA damage has been implicated as one of the photochemical events that results in the formation of these pathological changes. The ability of sunscreens to protect against UVR-induced DNA damage has not been well characterized especially with UVA (320-400 nm) wavelengths and UVA absorbers. In this paper we present results of a study aimed at determining the efficacy of two sunscreens at preventing the induction of pyrmidine dimers in basal cell DNA of mice exposed to solar-simulated UVR (SSUV) wavelengths (290-400 nm) or to UVA (320-400 nm). (author).

Does ultraviolet radiation affect the xanthophyll cycle in marine phytoplankton?

NARCIS (Netherlands)

van de Poll, W.H.; Buma, A.G.J.

2009-01-01

This Perspective summarizes the state of knowledge of the impact of ultraviolet radiation on the photoprotective xanthophyll cycle in marine phytoplankton. Excess photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet radiation (UVR; 280-400 nm) affect various cellular processes and

Effects of solar UV-B radiation on aquatic ecosystems

Science.gov (United States)

Häder, D.-P.

Solar UV degrades dissolved organic carbon photolytically so that they can readily be taken up by bacterioplankton. On the other hand solar UV radiation inhibits bacterioplankton activity. Bacterioplankton productivity is far greater than previously thought and is comparable to phytoplankton primary productivity. According to the "microbial loop hypothesis," bacterioplankton is seen in the center of a food web, having a similar function to phytoplankton and protists. The penetration of UV and PAR into the water column can be measured. Marine waters show large temporal and regional differences in their concentrations of dissolved and particulate absorbing substances. A network of dosimeters (ELDONET) has been installed in Europe ranging from Abisko in Northern Sweden to Gran Canaria. Cyanobacteria are capable of fixing atmospheric nitrogen which is then made available to higher plants. The agricultural potential of cyanobacteria has been recognized as a biological fertilizer for wet soils such as in rice paddies. UV-B is known to impair processes such as growth, survival, pigmentation, motility, as well as the enzymes of nitrogen metabolism and CO 2 fixation. The marine phytoplankton represents the single most important ecosystem on our planet and produces about the same biomass as all terrestrial ecosystems taken together. It is the base of the aquatic food chain and any changes in the size and composition of phytoplankton communities will directly affect food production for humans from marine sources. Another important role of marine phytoplankton is to serve as a sink for atmospheric carbon dioxide. Recent investigations have shown a large sensitivity of most phytoplankton organisms toward solar short-wavelength ultraviolet radiation (UV-B); even at ambient levels of UV-B radiation many organisms seem to be under UV stress. Because of their requirement for solar energy, the phytoplankton dwell in the top layers of the water column. In this near-surface position

Ultra-violet radiation: hazard in workplaces? (part II)

International Nuclear Information System (INIS)

Mohd Yusof Mohd Ali

2003-01-01

Not many workers are aware that apart from chemicals, physical agents, noise and machines which are known to be hazardous in workplaces, there exist another source of hazard which is equally important to be recognised and respected, that is hazard due to ultrviolet radiation (UV). This is the continuation of part I, which was discussed in the later issue. In this part, hazard of ultraviolet radiation were briefly discused i.e. effects on the skin and the eyes. Other subjects discussed are exposure limits, how to assess the radiation, protection against ultraviolet radiation

Solar Radiation effect on the bituminous binder; Efecto de la radiacion solar sobre el ligante bituminoso

Energy Technology Data Exchange (ETDEWEB)

Tadeo Rico, A.; Torres Perez, A.

2010-07-01

Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

The effect of solar ultraviolet radiation (UVR on induction of skin cancers

Directory of Open Access Journals (Sweden)

Marta Pacholczyk

2016-04-01

Full Text Available Ultraviolet radiation is a physical mutagenic and cancerogenic factor. About 95% of ultraviolet A (UVA (320–400 nm and 5% of UVB (280–320 nm reach the Earth’s surface. Melanin is a natural skin protective factor against UV radiation. Skin cancers associated with long-term exposure to UV radiation are: basal cell carcinoma (BCC, squamous cell carcinoma (SCC and cutaneous malignant melanoma (CMM. The high risk of BCC development is related to acute and repeated exposure to UV causing sunburn. Molecular studies of BBC demonstrated disorders in sonic hedgehog (SHH cell signaling regulation pathway, associated with the suppressor protein patched homolog 1 gene (PTCH1 mutations. The risk of the BCC development is related to the polymorphism of melanokortin-1 receptor gene (MC1R. Tumor P53 gene mutations observed in BCC cells has been classified as secondary genetic changes. In SCC cells UV-induced mutations were mostly related to P53 gene. Increased expression of cyclooxigenase- 2 gene (COX-2 plays a significant role in the development of SCC. Other pathogenetic factors include intensification of the synthesis of pro-inflammatory cytokines (tumor necrosis factor α (TNF-α, interleukin-1 α (IL-1α, IL-1β and IL-6. Currently, the role of UVB has been recognized in the pathogenesis of CMM. In CMM cells the following gene mutations were noted: cyclindependent kinase inhibitor 2A INK4A (p16INK4A, cyclin-dependent kinase 4 (CDK4, Ras, phosphatase and tensin homolog deleted on chromosome 10 (PTEN and proto-oncogene B-Raf (BRAF. The BRAF gene mutations were observed in ~50% of CMM cases. Mutations of P53 gene are not characteristic of CMM cells. Med Pr 2016;67(2:255–266

Data on solar sunburning ultraviolet (UVB radiation at an urban Mediterranean climate

Directory of Open Access Journals (Sweden)

Katerina G. Pantavou

2017-04-01

Full Text Available This article describes data on the intensity of ultraviolet B (UVB radiation collected during field questionnaire-based surveys in Athens, Greece. The surveys were conducted over 11 days of July and October 2010 at three different urban, outdoor sites. A total of 1104 interviews were conducted. The participants were asked to report whether they felt they got a sunburn at the moment of the interview. Questions related to personal characteristics including skin type and exposure time (visit duration at the interview site were also included in the questionnaire.

Mechanisms of plant resistance to increased solar ultraviolet-B radiation. Final report

International Nuclear Information System (INIS)

Teramura, A.H.; Sullivan, J.H.

1988-05-01

Since the major conclusions of the project are being disseminated via the scientific literature, the final report consists of a compilation of 11 articles and manuscripts on the effects of ultraviolet-B radiation (UVB) on soybean growth and yield, stress interactions with UVB, and effects of UVB on seedling growth in conifers (the Pinaceae). The effects of UVB on soybeans under field and greenhouse conditions, and under water stress, drought stress and phosphorus deficiency were studied. Soybean yields, seed quality, and physiology, including seed fatty acid and sterol composition, were determined

Solar ultraviolet radiation in Australia. Results from network measurements and their use in public education

International Nuclear Information System (INIS)

Roy, C.R.; Gies, H.P.; Lokan, K.H.

1993-01-01

Growing evidence of global depletion of stratospheric ozone has given additional support to the ultraviolet radiation (UVR) network established by ARL in Australia and Antarctica. The data produced is necessary to increase our knowledge of atmospheric change, human health studies and for public education. (4 figs., 1 tab.)

Threat of ultraviolet radiation to the eye--how to protect against it

International Nuclear Information System (INIS)

Pitts, D.G.

1981-01-01

The purpose of this paper is to discuss the effects of exposure of the eye to ultraviolet (UV) radiation and to provide information from which protective criteria and standards may be established. To accomplish this purpose, the article discusses ultraviolet radiation, absorption of UV radiation by the eye, the effects of ocular exposure to ultraviolet radiation, and how to protect the eye against exposure to UV radiation

Study of effect ultraviolet radiation on Aspergillus Flavus and Aspergillus Parasiticus

International Nuclear Information System (INIS)

Ghafourian, H.; Kafaei, F.; Raouf, J.B.

2000-01-01

In this article the results of ultraviolet radiation effects on Aspergillus Flavus and Aspergillus parasiticus to reach the quality control standards are presented. The purpose was to test the effect of ultraviolet radiation in 254 nanometer wavelength for fungi decontamination with respect to the exposure time of radiation and the distance between samples and radiation source. The ultraviolet radiation effects on plates containing Aspergillus Flavus and Aspergillus Parasiticus fungi were studied in the exposure time duration of 30, to 360 seconds of a fixed distance, and also for variable distances from 10 to 40 cm at a given exposure time. It is shown that in the exposure time of more than 360 second the ultraviolet radiation exposure highly decreases the number of Aspergillus Flavus and Aspergillus Parasiticus fungi colonies. By reducing the distance, the number of colonies decreases and it is minimized at a 10 cm distance in the time exposure of 360 second. The above results show that the ultraviolet radiation is an effective method for food decontamination and can be used in industry

Inhibition of seagrass photosynthesis by ultraviolet-B radiation.

Science.gov (United States)

Trocine, R P; Rice, J D; Wells, G N

1981-07-01

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ultraviolet-B were investigated.Halodule was found to possess the greatest photosynthetic tolerance for ultraviolet-B. Photosynthesis in Syringodium was slightly more sensitive to ultraviolet-B while Halophila showed relatively little photosynthetic tolerance. Evidence for a photorepair mechanism was found only in Halodule. This mechanism effectively attenuated photosynthetic inhibition induced by ultraviolet-B dose rates and dosages in excess of natural conditions. Syringodium appeared to rely primarily on a thick epidermal cell layer to reduce photosynthetic damage. Halophila seemed to have no morphological or photorepair capabilities to deal with ultraviolet-B. This species appeared to rely on epiphytic and detrital shielding and the shade provided by other seagrasses to reduce ultraviolet-B irradiation to tolerable levels. The presence of epiphytes on leaf surfaces was found to reduce the extent of photosynthetic inhibition from ultraviolet-B exposure in all species.Observations obtained in this study seem to suggest the possibility of anthocyanin and/or other flavonoid synthesis as an adaptation to long term ultraviolet-B irradiation by these species. In addition, Halophila appears to obtain an increased photosynthetic tolerance to ultraviolet-B as an indirect benefit of chloroplast clumping to avoid photo-oxidation by intense levels of photosynthetically active radiation.

Solar constant values for estimating solar radiation

International Nuclear Information System (INIS)

Li, Huashan; Lian, Yongwang; Wang, Xianlong; Ma, Weibin; Zhao, Liang

2011-01-01

There are many solar constant values given and adopted by researchers, leading to confusion in estimating solar radiation. In this study, some solar constant values collected from literature for estimating solar radiation with the Angstroem-Prescott correlation are tested in China using the measured data between 1971 and 2000. According to the ranking method based on the t-statistic, a strategy to select the best solar constant value for estimating the monthly average daily global solar radiation with the Angstroem-Prescott correlation is proposed. -- Research highlights: → The effect of the solar constant on estimating solar radiation is investigated. → The investigation covers a diverse range of climate and geography in China. → A strategy to select the best solar constant for estimating radiation is proposed.

21 CFR 179.39 - Ultraviolet radiation for the processing and treatment of food.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultraviolet radiation for the processing and..., PROCESSING AND HANDLING OF FOOD Radiation and Radiation Sources § 179.39 Ultraviolet radiation for the processing and treatment of food. Ultraviolet radiation for the processing and treatment of food may be...

Ambient solar UV radiation and seasonal trends in potential sunburn risk among schoolchildren in South Africa

CSIR Research Space (South Africa)

Wright, CY

2011-07-01

Full Text Available The detrimental effects of excess personal solar ultraviolet (UV) radiation exposure include sunburn, immunosuppression and skin cancer. In South Africa, individuals with minimum natural protection from melanin, including fair-skinned individuals...

Ultraviolet radiation therapy and UVR dose models

Energy Technology Data Exchange (ETDEWEB)

Grimes, David Robert, E-mail: davidrobert.grimes@oncology.ox.ac.uk [School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland and Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Gray Laboratory, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ (United Kingdom)

2015-01-15

Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed.

Ultraviolet radiation therapy and UVR dose models

International Nuclear Information System (INIS)

Grimes, David Robert

2015-01-01

Ultraviolet radiation (UVR) has been an effective treatment for a number of chronic skin disorders, and its ability to alleviate these conditions has been well documented. Although nonionizing, exposure to ultraviolet (UV) radiation is still damaging to deoxyribonucleic acid integrity, and has a number of unpleasant side effects ranging from erythema (sunburn) to carcinogenesis. As the conditions treated with this therapy tend to be chronic, exposures are repeated and can be high, increasing the lifetime probability of an adverse event or mutagenic effect. Despite the potential detrimental effects, quantitative ultraviolet dosimetry for phototherapy is an underdeveloped area and better dosimetry would allow clinicians to maximize biological effect whilst minimizing the repercussions of overexposure. This review gives a history and insight into the current state of UVR phototherapy, including an overview of biological effects of UVR, a discussion of UVR production, illness treated by this modality, cabin design and the clinical implementation of phototherapy, as well as clinical dose estimation techniques. Several dose models for ultraviolet phototherapy are also examined, and the need for an accurate computational dose estimation method in ultraviolet phototherapy is discussed

Solar ultraviolet radiation induces biological alterations in human skin in vitro: Relevance of a well-balanced UVA/UVB protection

Directory of Open Access Journals (Sweden)

Françoise Bernerd

2012-01-01

Full Text Available Cutaneous damages such as sunburn, pigmentation, and photoaging are known to be induced by acute as well as repetitive sun exposure. Not only for basic research, but also for the design of the most efficient photoprotection, it is crucial to understand and identify the early biological events occurring after ultraviolet (UV exposure. Reconstructed human skin models provide excellent and reliable in vitro tools to study the UV-induced alterations of the different skin cell types, keratinocytes, fibroblasts, and melanocytes in a dose- and time-dependent manner. Using different in vitro human skin models, the effects of UV light (UVB and UVA were investigated. UVB-induced damages are essentially epidermal, with the typical sunburn cells and DNA lesions, whereas UVA radiation-induced damages are mostly located within the dermal compartment. Pigmentation can also be obtained after solar simulated radiation exposure of pigmented reconstructed skin model. Those models are also highly adequate to assess the potential of sunscreens to protect the skin from UV-associated damage, sunburn reaction, photoaging, and pigmentation. The results showed that an effective photoprotection is provided by broad-spectrum sunscreens with a potent absorption in both UVB and UVA ranges.

Solar ultraviolet radiation induces biological alterations in human skin in vitro: relevance of a well-balanced UVA/UVB protection.

Science.gov (United States)

Bernerd, Francoise; Marionnet, Claire; Duval, Christine

2012-06-01

Cutaneous damages such as sunburn, pigmentation, and photoaging are known to be induced by acute as well as repetitive sun exposure. Not only for basic research, but also for the design of the most efficient photoprotection, it is crucial to understand and identify the early biological events occurring after ultraviolet (UV) exposure. Reconstructed human skin models provide excellent and reliable in vitro tools to study the UV-induced alterations of the different skin cell types, keratinocytes, fibroblasts, and melanocytes in a dose- and time-dependent manner. Using different in vitro human skin models, the effects of UV light (UVB and UVA) were investigated. UVB-induced damages are essentially epidermal, with the typical sunburn cells and DNA lesions, whereas UVA radiation-induced damages are mostly located within the dermal compartment. Pigmentation can also be obtained after solar simulated radiation exposure of pigmented reconstructed skin model. Those models are also highly adequate to assess the potential of sunscreens to protect the skin from UV-associated damage, sunburn reaction, photoaging, and pigmentation. The results showed that an effective photoprotection is provided by broad-spectrum sunscreens with a potent absorption in both UVB and UVA ranges.

CAN A NANOFLARE MODEL OF EXTREME-ULTRAVIOLET IRRADIANCES DESCRIBE THE HEATING OF THE SOLAR CORONA?

Energy Technology Data Exchange (ETDEWEB)

Tajfirouze, E.; Safari, H. [Department of Physics, University of Zanjan, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

2012-01-10

Nanoflares, the basic units of impulsive energy release, may produce much of the solar background emission. Extrapolation of the energy frequency distribution of observed microflares, which follows a power law to lower energies, can give an estimation of the importance of nanoflares for heating the solar corona. If the power-law index is greater than 2, then the nanoflare contribution is dominant. We model a time series of extreme-ultraviolet emission radiance as random flares with a power-law exponent of the flare event distribution. The model is based on three key parameters: the flare rate, the flare duration, and the power-law exponent of the flare intensity frequency distribution. We use this model to simulate emission line radiance detected in 171 A, observed by Solar Terrestrial Relation Observatory/Extreme-Ultraviolet Imager and Solar Dynamics Observatory/Atmospheric Imaging Assembly. The observed light curves are matched with simulated light curves using an Artificial Neural Network, and the parameter values are determined across the active region, quiet Sun, and coronal hole. The damping rate of nanoflares is compared with the radiative losses cooling time. The effect of background emission, data cadence, and network sensitivity on the key parameters of the model is studied. Most of the observed light curves have a power-law exponent, {alpha}, greater than the critical value 2. At these sites, nanoflare heating could be significant.

Solar glint suppression in compact planetary ultraviolet spectrographs

Science.gov (United States)

Davis, Michael W.; Cook, Jason C.; Grava, Cesare; Greathouse, Thomas K.; Gladstone, G. Randall; Retherford, Kurt D.

2015-08-01

Solar glint suppression is an important consideration in the design of compact photon-counting ultraviolet spectrographs. Southwest Research Institute developed the Lyman Alpha Mapping Project for the Lunar Reconnaissance Orbiter (launch in 2009), and the Ultraviolet Spectrograph on Juno (Juno-UVS, launch in 2011). Both of these compact spectrographs revealed minor solar glints in flight that did not appear in pre-launch analyses. These glints only appeared when their respective spacecraft were operating outside primary science mission parameters. Post-facto scattered light analysis verifies the geometries at which these glints occurred and why they were not caught during ground testing or nominal mission operations. The limitations of standard baffle design at near-grazing angles are discussed, as well as the importance of including surface scatter properties in standard stray light analyses when determining solar keep-out efficiency. In particular, the scattered light analysis of these two instruments shows that standard "one bounce" assumptions in baffle design are not always enough to prevent scattered sunlight from reaching the instrument focal plane. Future builds, such as JUICE-UVS, will implement improved scattered and stray light modeling early in the design phase to enhance capabilities in extended mission science phases, as well as optimize solar keep out volume.

An assessment of ultraviolet radiation components of light emitted ...

African Journals Online (AJOL)

An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

A model to calculate solar radiation fluxes on the Martian surface

Directory of Open Access Journals (Sweden)

Vicente-Retortillo Álvaro

2015-01-01

Full Text Available We present a new comprehensive radiative transfer model to study the solar irradiance that reaches the surface of Mars in the spectral range covered by MetSIS, a sensor aboard the Mars MetNet mission that will measure solar irradiance in several bands from the ultraviolet (UV to the near infrared (NIR. The model includes up-to-date wavelength-dependent radiative properties of dust, water ice clouds, and gas molecules. It enables the characterization of the radiative environment in different spectral regions under different scenarios. Comparisons between the model results and MetSIS observations will allow for the characterization of the temporal variability of atmospheric optical depth and dust size distribution, enhancing the scientific return of the mission. The radiative environment at the Martian surface has important implications for the habitability of Mars as well as a strong impact on its atmospheric dynamics and climate.

Coral skeletons defend against ultraviolet radiation.

Directory of Open Access Journals (Sweden)

Ruth Reef

Full Text Available BACKGROUND: Many coral reef organisms are photosynthetic or have evolved in tight symbiosis with photosynthetic symbionts. As such, the tissues of reef organisms are often exposed to intense solar radiation in clear tropical waters and have adapted to trap and harness photosynthetically active radiation (PAR. High levels of ultraviolet radiation (UVR associated with sunlight, however, represent a potential problem in terms of tissue damage. METHODOLOGY/PRINCIPAL FINDINGS: By measuring UVR and PAR reflectance from intact and ground bare coral skeletons we show that the property of calcium carbonate skeletons to absorb downwelling UVR to a significant extent, while reflecting PAR back to the overlying tissue, has biological advantages. We placed cnidarians on top of bare skeletons and a UVR reflective substrate and showed that under ambient UVR levels, UVR transmitted through the tissues of cnidarians placed on top of bare skeletons were four times lower compared to their counterparts placed on a UVR reflective white substrate. In accordance with the lower levels of UVR measured in cnidarians on top of coral skeletons, a similar drop in UVR damage to their DNA was detected. The skeletons emitted absorbed UVR as yellow fluorescence, which allows for safe dissipation of the otherwise harmful radiation. CONCLUSIONS/SIGNIFICANCE: Our study presents a novel defensive role for coral skeletons and reveals that the strong UVR absorbance by the skeleton can contribute to the ability of corals, and potentially other calcifiers, to thrive under UVR levels that are detrimental to most marine life.

Solar Ultraviolet-B Radiation Increases Phenolic Content and Ferric Reducing Antioxidant Power in Avena sativa

Directory of Open Access Journals (Sweden)

Christopher T. Ruhland

2007-06-01

Full Text Available We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm on the maximum photochemical efficiency of photosystem II (Fv/Fm, bulk-soluble phenolic concentrations, ferric-reducing antioxidant power (FRAP and growth of Avena sativa. Treatments involved placing filters on frames over potted plants that reduced levels of biologically effective UV-B by either 71% (reduced UV-B or by 19% (near-ambient UV-B over the 52 day experiment (04 July - 25 August 2002. Plants growing under near-ambient UV-B had 38% less total biomass than those under reduced UV-B. The reduction in biomass was mainly the result of a 24% lower leaf elongation rate, resulting in shorter leaves and less total leaf area than plants under reduced UV-B. In addition, plants growing under near-ambient UV-B had up to 17% lower Fv/Fm values early in the experiment, and this effect declined with plant age. Concentrations of bulk-soluble phenolics and FRAP values were 17 and 24% higher under near-ambient UV-B than under reduced UV-B, respectively. There was a positive relationship between bulk-soluble phenolic concentrations and FRAP values. There were no UV-B effects on concentrations of carotenoids (carotenes + xanthophylls.

Vulnerability and behavioral response to ultraviolet radiation in the components of a foliar mite prey-predator system

Science.gov (United States)

Tachi, Fuyuki; Osakabe, Masahiro

2012-12-01

Ambient ultraviolet-B (UVB) radiation impacts plant-dwelling arthropods including herbivorous and predatory mites. However, the effects of UVB on prey-predator systems, such as that between the herbivorous spider mite and predatory phytoseiid mite, are poorly understood. A comparative study was conducted to determine the vulnerability and behavioral responses of these mites to ultraviolet (UV) radiation. First, we analyzed dose-response (cumulative irradiance-mortality) curves for the eggs of phytoseiid mites ( Neoseiulus californicus, Neoseiulus womersleyi, and Phytoseiulus persimilis) and the spider mite ( Tetranychus urticae) to UVB radiation from a UV lamp. This indicated that the phytoseiid mites were more vulnerable than the spider mite, although P. persimilis was slightly more tolerant than the other two phytoseiid mites. Second, we compared the avoidance behavior of adult female N. californicus and two spider mite species ( T. urticae, a lower leaf surface user; Panonychus citri, an upper leaf surface user) in response to solar UV and visible light. N. californicus actively avoided both types of radiation, whereas P. citri showed only minimal avoidance behavior. T. urticae actively avoided UV as well as N. californicus but exhibited a slow response to visible light as well as P. citri. Such variation in vulnerability and avoidance behavior accounts for differences in the species adaptations to solar UVB radiation. This may be the primary factor determining habitat use among these mites on host plant leaves, subsequently affecting accessibility by predators and also intraguild competition.

Solar ultraviolet and the occupational radiant exposure of Queensland school teachers: A comparative study between teaching classifications and behavior patterns.

Science.gov (United States)

Downs, Nathan J; Harrison, Simone L; Chavez, Daniel R Garzon; Parisi, Alfio V

2016-05-01

Classroom teachers located in Queensland, Australia are exposed to high levels of ambient solar ultraviolet as part of the occupational requirement to provide supervision of children during lunch and break times. We investigated the relationship between periods of outdoor occupational radiant exposure and available ambient solar radiation across different teaching classifications and schools relative to the daily occupational solar ultraviolet radiation (HICNIRP) protection standard of 30J/m(2). Self-reported daily sun exposure habits (n=480) and personal radiant exposures were monitored using calibrated polysulphone dosimeters (n=474) in 57 teaching staff from 6 different schools located in tropical north and southern Queensland. Daily radiant exposure patterns among teaching groups were compared to the ambient UV-Index. Personal sun exposures were stratified among teaching classifications, school location, school ownership (government vs non-government), and type (primary vs secondary). Median daily radiant exposures were 15J/m(2) and 5J/m(2)HICNIRP for schools located in northern and southern Queensland respectively. Of the 474 analyzed dosimeter-days, 23.0% were found to exceed the solar radiation protection standard, with the highest prevalence found among physical education teachers (57.4% dosimeter-days), followed by teacher aides (22.6% dosimeter-days) and classroom teachers (18.1% dosimeter-days). In Queensland, peak outdoor exposure times of teaching staff correspond with periods of extreme UV-Index. The daily occupational HICNIRP radiant exposure standard was exceeded in all schools and in all teaching classifications. Copyright © 2016 Elsevier B.V. All rights reserved.

Current and future impacts of ultraviolet radiation on the terrestrial carbon balance

Institute of Scientific and Technical Information of China (English)

W. Kolby SMITH; Wei GAO; Heidi STELTZER

2009-01-01

One of the most documented effects of human activity on our environment is the reduction of stratospheric ozone resulting in an increase of biologically harmful ultraviolet (UV) radiation. In a less predictable manner, UV radiation incident at the surface of the earth is expected to be further modified in the future as a result of altered cloud condition, atmospheric aerosol concentration, and snow cover. Although UV radiation comprises only a small fraction of the total solar radiation that is incident at the earth's surface, it has the greatest energy per unit wavelength and, thus, the greatest potential to damage the biosphere. Recent investigations have highlighted numerous ways that UV radiation could potentially affect a variety of ecological processes, including nutrient cycling and the terrestrial carbon cycle. The objectives of the following literature review are to summarize and synthesize the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research.

Photodamage to human skin by suberythemal exposure to solar ultraviolet radiation can be attenuated by sunscreens: a review.

Science.gov (United States)

Seité, S; Fourtanier, A; Moyal, D; Young, A R

2010-11-01

The effects of acute or repeated suberythemal solar ultraviolet radiation (UVR) exposure on human skin have been insufficiently investigated. Such exposure almost certainly has important long-term consequences that include skin ageing and skin cancer. This review summarizes the published data on the biological effects of suberythemal exposure using a wide range of clinical, cellular and molecular endpoints, some of which may be considered as biomarkers for skin cancer and photoageing. We also include some recent unpublished results from our laboratories. The effects of UVA (320-400 nm), UVB (290-320 nm) and total solar UVR (290-400 nm) are compared. We demonstrate that avoiding sunburn does not prevent many indicators of cutaneous biological damage and that use of low sun protection factor (SPF) sunscreen can inhibit much of the damages induced by suberythemal exposure to UVR. However, even when applied correctly, sunscreen use will result in suberythemal exposure. The degree and spectral quality of such exposure will depend on the SPF and absorption spectrum of the sunscreen, but nonetheless it may contribute to cumulative photodamage. This review may help to determine the level of photoprotection required in sunscreens and daily use products, as well as the ideal ratio of UVB/UVA protection, to improve long-term photoprotection outcomes. © 2010 The Authors. BJD © 2010 British Association of Dermatologists.

Enhancement of growth and lipid production from microalgae using fluorescent paint under the solar radiation.

Science.gov (United States)

Seo, Yeong Hwan; Cho, Changsoon; Lee, Jung-Yong; Han, Jong-In

2014-12-01

Solar radiation has intensity that is too high to inhibit microalgae activity and is composed of wide light spectrum including ultraviolet (UV) range which cannot be utilized for microalgae. For these reasons, the modification of solar radiation is required for effective microalgae cultivation, and to do that, fluorescent paint was used for not only blocking excessive solar energy but also converting UV to visible light. With fluorescent aqueous layer, microalgae was protected from photoinhibition and could grow well, but there was difference in growth and lipid accumulation efficiencies depending on the color; maximum dry weight of 1.7 g/L was achieved in red paint, whereas best lipid content of 30% was obtained in blue one. This phenomenon was due to the different light spectrum made by colors. With simple process using fluorescent paint, modification of light was successfully done and allowing microalgae to grow under strong radiation such as solar radiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nrf2 Activation Protects against Solar-Simulated Ultraviolet Radiation in Mice and Humans.

Science.gov (United States)

Knatko, Elena V; Ibbotson, Sally H; Zhang, Ying; Higgins, Maureen; Fahey, Jed W; Talalay, Paul; Dawe, Robert S; Ferguson, James; Huang, Jeffrey T-J; Clarke, Rosemary; Zheng, Suqing; Saito, Akira; Kalra, Sukirti; Benedict, Andrea L; Honda, Tadashi; Proby, Charlotte M; Dinkova-Kostova, Albena T

2015-06-01

The transcription factor Nrf2 determines the ability to adapt and survive under conditions of electrophilic, oxidative, and inflammatory stress by regulating the expression of elaborate networks comprising nearly 500 genes encoding proteins with versatile cytoprotective functions. In mice, disruption of Nrf2 increases susceptibility to carcinogens and accelerates disease pathogenesis. Paradoxically, Nrf2 is upregulated in established human tumors, but whether this upregulation drives carcinogenesis is not known. Here we show that the incidence, multiplicity, and burden of solar-simulated UV radiation-mediated cutaneous tumors that form in SKH-1 hairless mice in which Nrf2 is genetically constitutively activated are lower than those that arise in their wild-type counterparts. Pharmacologic Nrf2 activation by topical biweekly applications of small (40 nmol) quantities of the potent bis(cyano enone) inducer TBE-31 has a similar protective effect against solar-simulated UV radiation in animals receiving long-term treatment with the immunosuppressive agent azathioprine. Genetic or pharmacologic Nrf2 activation lowers the expression of the pro-inflammatory factors IL6 and IL1β, and COX2 after acute exposure of mice to UV radiation. In healthy human subjects, topical applications of extracts delivering the Nrf2 activator sulforaphane reduced the degree of solar-simulated UV radiation-induced skin erythema, a quantifiable surrogate endpoint for cutaneous damage and skin cancer risk. Collectively, these data show that Nrf2 is not a driver for tumorigenesis even upon exposure to a very potent and complete carcinogen and strongly suggest that the frequent activation of Nrf2 in established human tumors is a marker of metabolic adaptation. ©2015 American Association for Cancer Research.

Comparison of Five Modeling Approaches to Quantify and Estimate the Effect of Clouds on the Radiation Amplification Factor (RAF) for Solar Ultraviolet Radiation

Data.gov (United States)

U.S. Environmental Protection Agency — Ultraviolet Radiation (UV) data collected at 21 US Environmental Protection Agency sites throughout the continental US, Alaska, Hawaii, and the US Virgin Islands...

Solar cataract: A clinical report | Ahuama | Journal of Health and ...

African Journals Online (AJOL)

Solar Ultraviolet radiation is caractogenic, as there is increasing evidence implicating ultraviolet radiation as a risk factor in the aetiology of cataracts. Through absorption from sunlight exposure especially into the violet and of the visible range of the solar spectrum, cataract formation may occur due to physiochemical ...

Molecular effects of 1-naphthyl-methylcarbamate and solar radiation exposures on human melanocytes.

Science.gov (United States)

Ferrucio, Bianca; Tiago, Manoela; Fannin, Richard D; Liu, Liwen; Gerrish, Kevin; Maria-Engler, Silvya Stuchi; Paules, Richard S; Barros, Silvia Berlanga de Moraes

2017-02-01

Carbaryl (1-naphthyl-methylcarbamate), a broad-spectrum insecticide, has recently been associated with the development of cutaneous melanoma in an epidemiological cohort study with U.S. farm workers also exposed to ultraviolet radiation, the main etiologic factor for skin carcinogenesis. We hypothesized that carbaryl exposure may increase deleterious effects of UV solar radiation on skin melanocytes. This study aimed to characterize human melanocytes after individual or combined exposure to carbaryl (100μM) and solar radiation (375mJ/cm 2 ). In a microarray analysis, carbaryl, but not solar radiation, induced an oxidative stress response, evidenced by the upregulation of antioxidant genes, such as Hemeoxygenase-1 (HMOX1), and downregulation of Microphtalmia-associated Transcription Factor (MITF), the main regulator of melanocytic activity; results were confirmed by qRT-PCR. Carbaryl and solar radiation induced a gene response suggestive of DNA damage and cell cycle alteration. The expression of CDKN1A, BRCA1/2 and MDM2 genes was notably more intense in the combined treatment group, in a synergistic manner. Flow cytometry assays demonstrated S-phase cell cycle arrest, reduced apoptosis levels and faster induction of cyclobutane pyrimidine dimers (CPD) lesions in carbaryl treated groups. Our data suggests that carbaryl is genotoxic to human melanocytes, especially when associated with solar radiation. Copyright © 2016 Elsevier B.V. All rights reserved.

Accelerated Solar-UV Test Chamber

Science.gov (United States)

Gupta, A.; Laue, E. G.

1984-01-01

Medium-pressure mercury-vapor lamps provide high ratio of ultraviolet to total power. Chamber for evaluating solar-ultraviolet (UV) radiation damage permits accelerated testing without overheating test specimens.

Parameterization models for solar radiation and solar technology applications

Energy Technology Data Exchange (ETDEWEB)

Khalil, Samy A. [National Research Institute of Astronomy and Geophysics, Solar and Space Department, Marsed Street, Helwan, 11421 Cairo (Egypt)

2008-08-15

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined. (author)

Parameterization models for solar radiation and solar technology applications

International Nuclear Information System (INIS)

Khalil, Samy A.

2008-01-01

Solar radiation is very important for the evaluation and wide use of solar renewable energy systems. The development of calibration procedures for broadband solar radiation photometric instrumentation and the improvement of broadband solar radiation measurement accuracy have been done. An improved diffuse sky reference and photometric calibration and characterization software for outdoor pyranometer calibrations are outlined. Parameterizations for direct beam, total hemispherical and diffuse sky radiation and solar radiation technology are briefly reviewed. The uncertainties for various broadband solar radiations of solar energy and atmospheric effects are discussed. The varying responsivities of solar radiation with meteorological, statistical and climatological parameters and possibility atmospheric conditions was examined

Ultraviolet radiation

International Nuclear Information System (INIS)

Hawk, J.

1986-01-01

Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

Inconstant sun: how solar evolution has affected cosmic and ultraviolet radiation exposure over the history of life on Earth.

Science.gov (United States)

Karam, P Andrew

2003-03-01

Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.

A novel sensor array for field based ocular ultraviolet radiation measurements

International Nuclear Information System (INIS)

Fleming, D. P.; Walsh, J. E.; Moore, L. A.; Bergmanson, J. P.; McMahon, D.

2006-01-01

The intensification of terrestrial solar ultraviolet radiation (UVR) due to the diminution of the ozone layer has promoted a variety of research into establishing the impact of this elevated potential dose of UVR on biological tissues. Certain anterior ocular tissues have been found to be susceptible to damage by incident UVR and potentially blinding diseases such as pterygium are thought to be a direct result of absorbed UVR at the nasal limbus. There is a need for more accurate quantification and localisation of incident UVR at the anterior ocular surface. A novel solar blind photodiode sensor array system has been designed, constructed and tested for this purpose. Initial measurements to quantify the irradiance across the anterior ocular surface within the latitudes known as the 'pterygium belt' provide us with a set of core data for different head orientations and tilt angles and indicate the accuracy and stability of the system. (authors)

Solar ultraviolet radiation alters alder and birch litter chemistry that in turn affects decomposers and soil respiration.

Science.gov (United States)

Kotilainen, Titta; Haimi, Jari; Tegelberg, Riitta; Julkunen-Tiitto, Riitta; Vapaavuori, Elina; Aphalo, Pedro Jose

2009-10-01

Solar ultraviolet (UV)-A and UV-B radiation were excluded from branches of grey alder (Alnus incana) and white birch (Betula pubescens) trees in a field experiment. Leaf litter collected from these trees was used in microcosm experiments under laboratory conditions. The aim was to evaluate the effects of the different UV treatments on litter chemical quality (phenolic compounds, C, N and lignin) and the subsequent effects of these changes on soil fauna and decomposition processes. We measured the decomposition rate of litter, growth of woodlice (Porcellio scaber), soil microbial respiration and abundance of nematodes and enchytraeid worms. In addition, the chemical quality of woodlice feces was analyzed. The exclusion of both UV-A and UV-B had several effects on litter chemistry. Exclusion of UV-B radiation decreased the C content in litter in both tree species. In alder litter, UV exclusion affected concentration of phenolic groups variably, whereas in birch litter there were no significant differences in phenolic compounds. Moreover, further effects on microbial respiration and chemical quality of woodlice feces were apparent. In both tree species, microbial CO(2) evolution was lower in soil with litter produced under exclusion of both UV-A and UV-B radiation when compared to soil with control litter. The N content was higher in the feces of woodlice eating alder litter produced under exclusion of both UV-A and UV-B compared to the control. In addition, there were small changes in the concentration of individual phenolic compounds analyzed from woodlice feces. Our results demonstrate that both UV-A and UV-B alter litter chemistry which in turn affects decomposition processes.

Ultraviolet-B-effects on plants: Spectra of harmful effects, primary damage and UV protective mechanisms

International Nuclear Information System (INIS)

Wellmann, E.; Beggs, C.; Moehle, B.; Schneider-Ziebert, U.; Steinmetz, V.; Koch, U.

1986-01-01

In two model systems of higher plants, damage caused by ultraviolet-B-radiation was analysed as to its mechanism of action and the spectral quantum efficiency. These investigations were to provide information on the relevance of such UV effects in cases of increased ultraviolet-B-irradiation owing to the destruction of ozone. The results indicate the very high tolerance of the plants to ultraviolet-B-radiation which obviously is the result of very effective protective mechanisms, and show at the same time that potential damage must already be reckoned with, given the current share of ultraviolet-B-radiation in solar radiation. Should ultraviolet-B-radiation be increased, then indirect damage to the plant from the destruction of ultraviolet protective mechanisms through UV-B-radiation will probably constitute a particular risk. (orig./MG) [de

The potential sensitivity of tropical plants to increased ultraviolet-B radiation

International Nuclear Information System (INIS)

Ziska, L.H.

1996-01-01

Little is known concerning the impact of stratospheric ozone depletion and increasing ultraviolet (UV)-B radiation on the phenology and growth of tropical plants. This is because, ostensibly, tropical plants are already exposed to relatively high levels of UV-B radiation (relative to a temperate environment) and should, therefore, possess a greater degree of tolerance to increased UV-B radiation. In this brief review I hope to show that, potentially, direct and indirect effects on photosynthesis, assimilate partitioning, phenology and biomass could occur in both tropical crops (e.g. cassava, rice) and native species (e.g. Cecropia obtusifolia (Bertol. Fl)., Tetramolopium humile (Gray), Nana sandwicensis L.). However, it should be noted that differences in sensitivity to UV-B radiation can be related to experimental conditions, and care should be taken to ensure that the quantity and quality of background solar radiation remains at near ambient conditions. Nevertheless, by integrating current and past studies on the impact of UV-B radiation on tropical species, I hope to be able to demonstrate that photosynthesis, morphology and growth in tropical plants could be directly affected by UV-B radiation and that UV-B radiation may be a factor in species and community dynamics in natural plant populations in the tropics

A model investigation of annual surface ultraviolet radiation in Iran

International Nuclear Information System (INIS)

Sabziparvar, A.-A.

2003-01-01

In recent years, there has been some concern regarding solar ultraviolet (UV) radiation received at the earth,s surface because of its biological hazards affecting living organisms. Although the geographical distribution of ground-based UV network is relatively good in some continents,but over Asia, the number of UV instruments are not sufficient for meteorological and biological purposes. Iran, as an Asian country, is also suffering from the lack of UV monitoring network with the exception of one ground-based UV spectrophotometer site (Brower III) at Esfahan. Using a complex radiative transfer model and various meteorological data (for 8 years) such as total column ozone, cloudiness, surface albedo, surface air pressure, relative humidity, visibility and daily total solar radiation (TSR), the geographical distribution of annual integrated biological surface UV irradiances such as UVB, erythema and cataracts are calculated. The comparison is made for cloud-free and all-sky conditions for eight selected cities distributed from the southern tip of the country (25 N-60 E) to the northern border (39 N-48 E). It is shown that the difference between the annual UV at south and north in all-sky condition is larger than the differences in cloud-free condition. The ratio of some biological UV irradiances at southern cities to the same component at northern cities shows a factor of two and more which is quite significant. The possible reasons which might cause such differences are discussed

Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation

International Nuclear Information System (INIS)

Flint, S.D.; Caldwell, M.M.

1984-01-01

Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined

Solar irradiance changes and photobiological effects at earth's surface following astrophysical ionizing radiation events.

Science.gov (United States)

Thomas, Brian C; Neale, Patrick J; Snyder, Brock R

2015-03-01

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the Tropospheric Ultraviolet and Visible (TUV) radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance but that relative estimates for increase in exposure to DNA-damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in very limited geographical areas; instead we found a net increase for most of the modeled time-space region. This result has implications for proposed climate changes associated with ionizing radiation events.

Ultraviolet - status of knowledge on exposure and health risks

International Nuclear Information System (INIS)

Dervault, Anne Marie; Secretan, Beatrice; Guinot, Christiane; Bazex, Jacques; Donadieu, Jean; Dore, Jean Francois; Cesarini, Jean Pierre; Aleth Richard, Marie; Leccia, Marie Therese; Autier, Philippe; Cesarini, Jean Pierre; Beani, Jean Claude; Grob, Jean Jacques; Wald, Lucien; Dore, Jean Francois; Casiniere, Alain de la; Dixsaut, Gilles; Guenel, Pascal; Choulika, Sophie; Pirard, Philippe; Bastuji-Garin, S.; Beani, J.C.; Brin, A.J.; Cadet, J.; Corre, M.F.; Frelon, J.H.; Grob, Jean Jacques; Jeanmougin, M.; Martini-Morel, M.C.; Meunier, L.; Marty, J.P.; Revuz, J.; Reynier, J.P.; Roelands, R.; Stoebner, A.; Vian, L.

2005-05-01

After having recalled some physical aspects of ultraviolet radiations (presence in solar radiation, artificial UV radiation, measurement, metrology, UV index, boundary limits), this report describes the biological and health effects of UV radiations (analysis methodology, recall of previous expert reports, biological effects, health effects), addresses human behaviour with respect to UV radiation and exposure to UV radiation, discusses the relationship between cosmetics and UV radiation. It presents the various European and international positions with respect to UV emitting devices (evolution of standards, regulations). Some recommendations are made regarding solar exposure, sun-tanning installations, and other domestic or industrial sources

Ultraviolet spectral distribution and erythema-weighted irradiance from indoor tanning devices compared with solar radiation exposures.

Science.gov (United States)

Sola, Yolanda; Baeza, David; Gómez, Miguel; Lorente, Jerónimo

2016-08-01

Concern regarding the impact of indoor tanning devices on human health has led to different regulations and recommendations, which set limits on erythema-weighted irradiance. Here, we analyze spectral emissions from 52 tanning devices in Spanish facilities and compare them with surface solar irradiance for different solar zenith angles. Whereas most of the devices emitted less UV-B radiation than the midday summer sun, the unweighted UV-A irradiance was 2-6 times higher than solar radiation. Moreover, the spectral distributions of indoor devices were completely different from that of solar radiation, differing in one order of magnitude at some UV-A wavelengths, depending on the lamp characteristics. In 21% of the devices tested, the erythema-weighted irradiance exceeded 0.3Wm(-2): the limit fixed by the European standard and the Spanish regulation. Moreover, 29% of the devices fall within the UV type 4 classification, for which medical advice is required. The high variability in erythema-weighted irradiance results in a wide range of exposure times to reach 1 standard erythemal dose (SED: 100Jm(-2)), with 62% of devices requiring exposures of UV-A dose during this time period would be from 1.4 to 10.3 times more than the solar UV-A dose. Copyright © 2016 Elsevier B.V. All rights reserved.

Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

Directory of Open Access Journals (Sweden)

M. El Ghazaly

Full Text Available Photoluminescence (PL emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53–4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV to 400 (3.10 eV nm in step of 10 nm and the corresponding photoluminescence (PL emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC, the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation. Keywords: Photoluminescence spectra, Makrofol® DE 1-1, UV–vis spectrophotometry, Attenuation coefficient, Ultraviolet radiation

UV Irradiance Enhancements by Scattering of Solar Radiation from Clouds

Directory of Open Access Journals (Sweden)

Uwe Feister

2015-08-01

Full Text Available Scattering of solar radiation by clouds can reduce or enhance solar global irradiance compared to cloudless-sky irradiance at the Earth’s surface. Cloud effects to global irradiance can be described by Cloud Modification Factors (CMF. Depending on strength and duration, irradiance enhancements affect the energy balance of the surface and gain of solar power for electric energy generation. In the ultraviolet region, they increase the risk for damage to living organisms. Wavelength-dependent CMFs have been shown to reach 1.5 even in the UV-B region at low altitudes. Ground-based solar radiation measurements in the high Andes region at altitudes up to 5917 m a.s.l showed cloud-induced irradiance enhancements. While UV-A enhancements were explained by cloud scattering, both radiation scattering from clouds and Negative Ozone Anomalies (NOA have been discussed to have caused short-time enhancement of UV-B irradiance. Based on scenarios using published CMF and additional spectroradiometric measurements at a low-altitude site, the contribution of cloud scattering to the UV-B irradiance enhancement in the Andes region has been estimated. The range of UV index estimates converted from measured UV-B and UV-A irradiance and modeled cloudless-sky ratios UV-B/erythemal UV is compatible with an earlier estimate of an extreme UV index value of 43 derived for the high Andes.

Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

Science.gov (United States)

El Ghazaly, M.; Aydarous, Abdulkadir

Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53-4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV) to 400 (3.10 eV) nm in step of 10 nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

PMMA Wettability Caused by Ultraviolet Radiation

OpenAIRE

Dehtjars, J; Lancere, L; Poļaka, N; Soudnikovich, A; Tjuļkins, F; Valters, V

2010-01-01

The article is targeted to explore ultraviolet radiation (UV) influence on PMMAf or eye prostheses. UV beingt he Sun lightc omponenta nd could effect PMMA surface that in turn contributesi nteractionw ith tear. PMMA wettabilityw as poweredb y UV.

Photosynthetic carbon reduction by seagrasses exposed to ultraviolet A radiation

Science.gov (United States)

1979-01-01

The seagrasses Halophila engelmannii, Halodule wrightii, and Syringodium filiforme were examined for their intrinsic sensitivity to ultraviolet-A-UV-A and ultraviolet-B-UV-B radiation. The effect of UV-A on photosynthetically active radiation (PAR) was also determined. Ultraviolet-A and ultraviolet-B were studied with emphasis on the greater respective environmental consequence in terms of seagrass distribution and abundance. Results indicate that an intrinsic sensitivity to UV-A alone is apparent only in Halophila, while net photosynthesis in Halodule and Syringodium seems unaffected by the level of UV-A provided. The sensitivity of Halophila to UV-A in the absense of (PAR) indicates that the photosynthetic reaction does not need to be in operation for damage to occur. Other significant results are reported.

Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

Science.gov (United States)

Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

2007-01-01

We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

Study of solar radiation prediction and modeling of relationships between solar radiation and meteorological variables

International Nuclear Information System (INIS)

Sun, Huaiwei; Zhao, Na; Zeng, Xiaofan; Yan, Dong

2015-01-01

Highlights: • We investigate relationships between solar radiation and meteorological variables. • A strong relationship exists between solar radiation and sunshine duration. • Daily global radiation can be estimated accurately with ARMAX–GARCH models. • MGARCH model was applied to investigate time-varying relationships. - Abstract: The traditional approaches that employ the correlations between solar radiation and other measured meteorological variables are commonly utilized in studies. It is important to investigate the time-varying relationships between meteorological variables and solar radiation to determine which variables have the strongest correlations with solar radiation. In this study, the nonlinear autoregressive moving average with exogenous variable–generalized autoregressive conditional heteroscedasticity (ARMAX–GARCH) and multivariate GARCH (MGARCH) time-series approaches were applied to investigate the associations between solar radiation and several meteorological variables. For these investigations, the long-term daily global solar radiation series measured at three stations from January 1, 2004 until December 31, 2007 were used in this study. Stronger relationships were observed to exist between global solar radiation and sunshine duration than between solar radiation and temperature difference. The results show that 82–88% of the temporal variations of the global solar radiation were captured by the sunshine-duration-based ARMAX–GARCH models and 55–68% of daily variations were captured by the temperature-difference-based ARMAX–GARCH models. The advantages of the ARMAX–GARCH models were also confirmed by comparison of Auto-Regressive and Moving Average (ARMA) and neutral network (ANN) models in the estimation of daily global solar radiation. The strong heteroscedastic persistency of the global solar radiation series was revealed by the AutoRegressive Conditional Heteroscedasticity (ARCH) and Generalized Auto

ACCURATELY CALCULATING THE SOLAR ORIENTATION OF THE TIANGONG-2 ULTRAVIOLET FORWARD SPECTROMETER

Directory of Open Access Journals (Sweden)

Z. Liu

2018-04-01

Full Text Available The Ultraviolet Forward Spectrometer is a new type of spectrometer for monitoring the vertical distribution of atmospheric trace gases in the global middle atmosphere. It is on the TianGong-2 space laboratory, which was launched on 15 September 2016. The spectrometer uses a solar calibration mode to modify its irradiance. Accurately calculating the solar orientation is a prerequisite of spectral calibration for the Ultraviolet Forward Spectrometer. In this paper, a method of calculating the solar orientation is proposed according to the imaging geometric characteristics of the spectrometer. Firstly, the solar orientation in the horizontal rectangular coordinate system is calculated based on the solar declination angle algorithm proposed by Bourges and the solar hour angle algorithm proposed by Lamm. Then, the solar orientation in the sensor coordinate system is achieved through several coordinate system transforms. Finally, we calculate the solar orientation in the sensor coordinate system and evaluate its calculation accuracy using actual orbital data of TianGong-2. The results show that the accuracy is close to the simulation method with STK (Satellite Tool Kit, and the error is not more than 2 %. The algorithm we present does not need a lot of astronomical knowledge, but only needs some observation parameters provided by TianGong-2.

Photodegradation of antibiotics under simulated solar radiation: implications for their environmental fate.

Science.gov (United States)

Batchu, Sudha Rani; Panditi, Venkata R; O'Shea, Kevin E; Gardinali, Piero R

2014-02-01

Roxithromycin, erythromycin, ciprofloxacin and sulfamethoxazole are frequently detected antibiotics in environmental waters. Direct and indirect photolysis of these problematic antibiotics were investigated in pure and natural waters (fresh and salt water) under irradiation of different light sources. Fundamental photolysis parameters such as molar absorption coefficient, quantum yield and first order rate constants are reported and discussed. The antibiotics are degraded fastest under ultraviolet 254 nm, followed by 350 nm and simulated solar radiation. The composition of the matrix (pH, dissolved organic content, chloride ion concentration) played a significant role in the observed photodegradation. Under simulated solar radiation, ciprofloxacin and sulfamethoxazole degrade relatively quickly with half-lives of 0.5 and 1.5h, respectively. However, roxithromycin and erythromycin, macrolides are persistent (half-life: 2.4-10 days) under solar simulation. The transformation products (15) of the targeted antibiotics produced under irradiation experiments were identified using high resolution mass spectrometry and degradation pathways were proposed. © 2013.

Solar radiation over India

Energy Technology Data Exchange (ETDEWEB)

Mani, A; Rangarajan, S

1982-01-01

Solar radiation data, on horizontal and sloped surfaces, are provided derived from other meteorological parameters at 145 stations covering all major climatic zones of the country. Two methods were used to compute solar radiation, one using regression techniques to derive radiation from sunshine and cloudiness, the other from extra-terrestrial radiation, allowing for its depletion by absorption and scattering in the atmosphere. The methods of calculating the daily global radiation tilt factor using an anisotropic model for diffuse solar radiation are described. The results of statistical analysis of global solar radiation data recorded at 16 stations are presented. Appendices contain an extensive bibliograpny, sun path diagrams for latitudes 6/sup 0/N to 36/sup 0/N, and tables for the calculation of Local Apparent Time from Indian Standard Time.

The impact of ultraviolet radiation on timber

International Nuclear Information System (INIS)

Dawson, B.

1993-01-01

Photochemical degradation of timber, the outcome of exposure of timber to ultraviolet radiation, is a light induced chemical and physical decay. Timber is a collection of dead wood cells. Impacts of radiation on the growing tree are therefore outside the scope of this paper, which is primarily concerned with timber as a material. (author). 5 refs. 2 figs

Ultraviolet radiation, human health, and the urban forest

Science.gov (United States)

Gordon M. Heisler; Richard H. Grant

2000-01-01

Excess exposure to ultraviolet (UV) radiation from the sun, particularly the ultraviolet B (UVB) portion, has been linked with adverse effects on human health ranging from skin cancers to eye diseases such as cataracts. Trees may prevent even greater disease rates in humans by reducing UV exposure. Tree shade greatly reduces UV irradiance when both the sun and sky are...

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

International Nuclear Information System (INIS)

Thorseth, Trond Morten

2000-01-01

The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe

Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

Energy Technology Data Exchange (ETDEWEB)

Thorseth, Trond Morten

2000-07-01

The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

Effects of increased solar ultraviolet radiation on terrestrial plants

International Nuclear Information System (INIS)

Caldwell, M.M.; Teramura, A.H.; Tevini, M.; Bornman, J.F.; Björn, L.O.; Kulandaivelu, G.

1995-01-01

Physiological and developmental processes of plants are affected by UV-B radiation, even by the amount of UV-B in present-day sunlight. Plants also have several mechanisms to ameliorate or repair these effects and may acclimate to a certain extent to increased levels of UV-B. Nevertheless, plant growth can be directly affected by UV-B radiation. Response to UV-B also varies considerably among species and also cultivars of the same species. In agriculture, this may necessitate using more UV-B-tolerant cultivars and breeding new ones. In forests and grasslands, this will likely result in changes in species composition; therefore there are implications for the biodiversity in different ecosystems. Indirect changes caused by UV-B-such as changes in plant form, biomass allocation to parts of the plant, timing of developmental phases and secondary metabolism-may be equally, or sometimes more important than damaging effects of UV-B. These changes can have important implications for plant competitive balance, herbivory, plant pathogens, and biogeochemical cycles. These ecosystem-level effects can be anticipated, but not easily predicted or evaluated. Research at the ecosystem level for solar UV-B is barely beginning. Other factors, including those involved in climate change such as increasing CO2, also interact with UV-B. Such reactions are not easily predicted, but are of obvious importance in both agriculture and in nonagricultural ecosystems

Competitive interaction in plant populations exposed to supplementary ultraviolet-B radiation

International Nuclear Information System (INIS)

Fox, F.M.; Caldwell, M.M.; Utah State Univ., Logan

1978-01-01

Changes in plant growth and competitive balance between pairs of competing species were documented as a result of supplementary ultraviolet-B radiation (principally in the 290-315 nm waveband) under field conditions. This component of the terrestrial solar spectrum would be intensified if the atmospheric ozone layer were reduced. A method for calculating and statistically analyzing relative crowding coefficients was developed and used to evaluate the competitive status of the species pairs sown in a modified replacement series. The effect of the supplementary UV-B irradiance was generally detrimental to plant growth, and was reflected in decreased leaf area, biomass, height and density as well as changes competitive balance for various species. For some species, interspecific competition apparently accentuated the effect of the UV-B radiation, while more intense intraspecific competition may have had the same effect for other species. A few species when grown in a situation of more severe mutual interspecific competition exhibited enhanced growth under the UV-B radiation treatment. This, however, was usually associated with a detrimental effect of the radiation, on its competitor and thus was likely the result of its improved competitive circumstance rather than a benefical physiological effect of the radiation. (orig.) [de

Measurements of integrated direct, diffuse and global ultraviolet-B radiation

International Nuclear Information System (INIS)

Utrillas, M.P.; Pedrós, R.; Gandía, S.; Gómez-Amo, J.L.; Estellés, V.; Martínez-Lozano, J.A.

2015-01-01

We present the first multiyear set of simultaneous measurements of the global ultraviolet-B radiation and its two components: direct and diffuse. The measurements have been taken with four YES-UVB-1 radiometers: two radiometers to measure the diffuse radiation, one provided with a shadow band and the other with a shadow disk on a Sun tracker; a radiometer to measure the global horizontal radiation; and a Sun-tracking radiometer to measure the direct radiation with an especially designed radiance collimator. The diffuse minute-values measured with both instruments agree within a coefficient correlation of 1.00. The diffuse component represents at least 50% of the global UVB (ultraviolet-B) radiation. The minute values of global UVB irradiance obtained by adding the direct and diffuse components concur with the measured global irradiance. Therefore, the measurement of the direct irradiance enables the estimation of the diffuse component, and gives an insight into the factors that affect its value, especially aerosols. - Highlights: • Simultaneous measurements of global, direct and diffuse UVB (ultraviolet-B) radiation. • The diffuse minute-values are at least 50% of the global ones. • The diffuse measurements are highly correlated to the aerosol load. • The sum of direct + diffuse radiation concur with the measured global.

Effects of ultraviolet radiation on photosynthetic performance and N2 fixation in Trichodesmium erythraeum IMS 101

Science.gov (United States)

Cai, Xiaoni; Hutchins, David A.; Fu, Feixue; Gao, Kunshan

2017-10-01

Biological effects of ultraviolet radiation (UVR; 280-400 nm) on marine primary producers are of general concern, as oceanic carbon fixers that contribute to the marine biological CO2 pump are being exposed to increasing UV irradiance due to global change and ozone depletion. We investigated the effects of UV-B (280-320 nm) and UV-A (320-400 nm) on the biogeochemically critical filamentous marine N2-fixing cyanobacterium Trichodesmium (strain IMS101) using a solar simulator as well as under natural solar radiation. Short exposure to UV-B, UV-A, or integrated total UVR significantly reduced the effective quantum yield of photosystem II (PSII) and photosynthetic carbon and N2 fixation rates. Cells acclimated to low light were more sensitive to UV exposure compared to high-light-grown ones, which had more UV-absorbing compounds, most likely mycosporine-like amino acids (MAAs). After acclimation under natural sunlight, the specific growth rate was lower (by up to 44 %), MAA content was higher, and average trichome length was shorter (by up to 22 %) in the full spectrum of solar radiation with UVR, than under a photosynthetically active radiation (PAR) alone treatment (400-700 nm). These results suggest that prior shipboard experiments in UV-opaque containers may have substantially overestimated in situ nitrogen fixation rates by Trichodesmium, and that natural and anthropogenic elevation of UV radiation intensity could significantly inhibit this vital source of new nitrogen to the current and future oligotrophic oceans.

Radiation hard solar cell and array

International Nuclear Information System (INIS)

Russell, R.L.

1975-01-01

A power generating solar cell for a spacecraft solar array is hardened against transient response to nuclear radiation while permitting normal operation of the cell in a solar radiation environment by shunting the cell with a second solar cell whose contacts are reversed relative to the power cell to form a cell module, exposing the power cell only to the solar radiation in a solar radiation environment to produce an electrical output at the module terminals, and exposing both cells to the nuclear radiation in a nuclear radiation environment so that the radiation induced currents generated by the cells suppress one another

Ultraviolet radiation and blue-light emissions from spotlights incorporating tungsten halogen lamps

CERN Document Server

MacKinlay, Alistair F; Whillock, M J

1989-01-01

This report summarises measurements of the ultraviolet radiation and blue-light emissions from eleven 'desk-top' tungsten halogen (quartz) lamps and one 'floor-standing' tungsten halogen (quartz) lamp available in the UK. Values of occupational hazard weighted and erythemally weighted ultraviolet radiation irradiance and measurements and relevant calculations of blue-light hazards are presented. It is concluded that the safety design of some desk-top tungsten halogen lamps is inadequate to prevent unnecessary exposure of the skin to potentially harmful ultraviolet radiation. It is recommended that all tungsten halogen lamps should have sufficient filtration to reduce their ultraviolet emissions to an acceptably low level. As long as the comfort aversion responses of the eye are respected, direct viewing of the lamps examined should not constitute a retinal hazard.

Ultraviolet radiation and blue-light emissions from spotlights incorporating tungsten halogen lamps

International Nuclear Information System (INIS)

McKinlay, A.F.; Whillock, M.J.; Meulemans, C.C.E.

1989-07-01

This report summarises measurements of the ultraviolet radiation and blue-light emissions from eleven 'desk-top' tungsten halogen (quartz) lamps and one 'floor-standing' tungsten halogen (quartz) lamp available in the UK. Values of occupational hazard weighted and erythemally weighted ultraviolet radiation irradiance and measurements and relevant calculations of blue-light hazards are presented. It is concluded that the safety design of some desk-top tungsten halogen lamps is inadequate to prevent unnecessary exposure of the skin to potentially harmful ultraviolet radiation. It is recommended that all tungsten halogen lamps should have sufficient filtration to reduce their ultraviolet emissions to an acceptably low level. As long as the comfort aversion responses of the eye are respected, direct viewing of the lamps examined should not constitute a retinal hazard. (author)

Nonionising radiation and risk of human cancer: comparison of ultraviolet and radiofrequency radiation

International Nuclear Information System (INIS)

Green, A.

2003-01-01

Human exposure to ultraviolet radiation (UVR) comes largely from sunlight, although a small proportion of people receive high dose UVR from artificial sources. The causal link between solar UVR and the keratinocyte cancers, basal cell carcinomas and squamous cell carcinomas of the skin, is well-established based on a large body of observational and experimental evidence. UVR damages molecules such as DNA directly and this is the principal mechanism of carcinogenesis, though other mechanisms such as immunosuppression and interaction with viruses may also be involved. People are also exposed to another form of nonionising radiation, radiofrequency radiation (RFR), through occupation, the community environment from base stations, and through use of cellular telephones and related communications devices. However, unlike UVR, the relationship between RFR and cancer is far from clear. The main tumours that have been investigated to date are brain tumours and leukaemia but assessing the RFR exposure pathway to such cancers poses many methodological challenges for epidemiologists. Refinements to measurement of exposure are the major urgent need, and the lack of evidence regarding carcinogenic effects of RFR in experimental settings complicates the assessment. Further insights into the links between RFR and chronic disease such as cancer are likely in the next few years however when results of several large-scale epidemiological studies now in train around the world become available

Estimating hourly direct and diffuse solar radiation for the compilation of solar radiation distribution maps

International Nuclear Information System (INIS)

Ueyama, H.

2005-01-01

This paper presents a new method for estimating hourly direct and diffuse solar radiation. The essence of the method is the estimation of two important factors related to solar radiation, atmospheric transmittance and a dimensionless parameter, using empirical and physical equations and data from general meteorological observation stations. An equation for atmospheric transmittance of direct solar radiation and a dimensionless parameter representing diffuse solar radiation are developed. The equation is based on multiple regression analysis and uses three parameters as explanatory variates: calculated hourly extraterrestrial solar radiation on a horizontal plane, observed hourly sunshine duration and hourly precipitation as observed at a local meteorological observatory. The dimensionless parameter for estimating a diffuse solar radiation is then determined by linear least squares using observed hourly solar radiation at a local meteorological observatory. The estimated root mean square error (RMSE) of hourly direct and diffuse solar radiation is about 0.0-0.2 MJ¥m(-2)¥h(-1) in each mean period. The RMSE of the ten-day and monthly means of these quantities is about 0.0-0.2 MJ¥m(-2)¥h(-1), based on comparisons with AMeDAS station data, located at a distance of 6 km

Failure of supplementary ultraviolet radiation to enhance flower color under greenhouse conditions

Energy Technology Data Exchange (ETDEWEB)

Klein, R. M. [University of Vermont, Burlington, VT (United States)

1990-03-15

In order to determine whether the concentration of floral petal anthocyanin pigments could be increased, ultraviolet radiations in the UV-A and UV-B wavelength bands were presented to a variety of flowering plants to partly restore those wavelengths filtered out by greenhouse glass. In no tested plant did the supplementary ultraviolet radiation enhance floral anthocyanin content. Supplementary UV radiation has no economic value in greenhouse production of flowering plants. (author)

Health impacts of ultraviolet radiation in urban ecosystems: a review

Science.gov (United States)

Heisler, Gordon M.

2005-08-01

This paper explores the literature on ultraviolet irradiance (UV) in urban ecosystems with respect to the likely effects on human health. The focus was the question of whether the health effects of UV radiation should be included in planning of landscape elements such as trees and shading structures. In examining the literature, special attention was given to seeking information on the question of whether it is important that shade be provided for elementary school play areas, and if so, how should it be accomplished? Before such practical questions could be dealt with, it became obvious that answers to several pertinent secondary questions had to be sought. Foremost of these was, what are the negative and positive health effects of UV exposure? Recent epidemiological findings of apparent benefits of sunlight because of vitamin-D photosynthesis and resulting anti-cancer effects make this highly relevant. Another basic question is that of trends in ozone depletion, which leads to interesting questions of long-term trends, short-term extremes, and urban influences on UV irradiance. A host of these and other pertinent questions, such as, "What is the relationship between climate of a location and dress," i.e., "How much exposure will people receive during time spent outdoors?" require much more study. Judging from current knowledge of typical spectra of solar radiation in tree shade and the difference between the action spectra for vitamin D synthesis and erythema in human skin, exposure to solar radiation in tree shade for a short period of time can be somewhat more beneficial for vitamin D synthesis and regulation than detrimental in producing sunburn.

Solar and terrestrial physics. [effects of solar activities on earth environment

Science.gov (United States)

1975-01-01

The effects of solar radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the solar cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of solar cycle variation of the characteristics of the solar wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of solar shock waves are investigated. The solar and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.

The caretakers of the genome. Repair of DNA lesions induced by ultraviolet-light and ionizing radiation

International Nuclear Information System (INIS)

Boiteux, S.; Radicella, J.P.

2000-01-01

The DNA contained in the nucleus of each of our cells daily suffers of thousand damages caused by solar ultraviolet radiations or ionizing radiations, with a natural or not origin, agents able to modify the genetic information. This information stays stable. True caretakers of the genome repair the DNA, provided that the cell is not over-taken by the level of the attack. Alterations of the repair mechanism are at the origin of extremely severe syndromes. The failure of one of these caretakers of the genome, the O.G.G.1 gene, seems implicated in the cancer development. It can be a lead to discover a predisposition to radioinduced or caused by other toxic agents cancers. (N.C.)

Determination of daily solar ultraviolet radiation using statistical models and artificial neural networks

Directory of Open Access Journals (Sweden)

F. J. Barbero

2006-09-01

Full Text Available In this study, two different methodologies are used to develop two models for estimating daily solar UV radiation. The first is based on traditional statistical techniques whereas the second is based on artificial neural network methods. Both models use daily solar global broadband radiation as the only measured input. The statistical model is derived from a relationship between the daily UV and the global clearness indices but modulated by the relative optical air mass. The inputs to the neural network model were determined from a large number of radiometric and atmospheric parameters using the automatic relevance determination method, although only the daily solar global irradiation, daily global clearness index and relative optical air mass were shown to be the optimal input variables. Both statistical and neural network models were developed using data measured at Almería (Spain, a semiarid and coastal climate, and tested against data from Table Mountain (Golden, CO, USA, a mountainous and dry environment. Results show that the statistical model performs adequately in both sites for all weather conditions, especially when only snow-free days at Golden were considered (RMSE=4.6%, MBE= –0.1%. The neural network based model provides the best overall estimates in the site where it has been trained, but presents an inadequate performance for the Golden site when snow-covered days are included (RMSE=6.5%, MBE= –3.0%. This result confirms that the neural network model does not adequately respond on those ranges of the input parameters which were not used for its development.

Effects of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation

International Nuclear Information System (INIS)

Zhang Lei; Wang Lianxi; Li Fusheng

2009-01-01

[Objective]The experiment aimed to explore the influence of enhanced ultraviolet radiation-B on maize in arid regions of middle-high elevation for correct assessing the influence of enhanced ultraviolet radiation-B on maize and providing scientific reference to make proper countermeasures.[Method] The location test in field and lift lamp of UV-B were used to observe the changes of maize height , leaf area and number of green leaves under influences of different UV-B radiation. [Result]In arid regions of middle-high elevation, enhanced ultraviolet radiation-B could dwarf maize plant, decrease leaf area, decline number of green leaves and yield. The reason of decreasing leaf area was that enhanced ultraviolet radiation-B shortened leaf length and leaf width while the reason of declining yield was that yield components were all negatively influenced and with the increase of ultraviolet radiation-B, the yield declined dramatically.[Conclusion]The result of this experiment would be good for maize production in arid regions of middle-high elevation

Solar ultraviolet radiation-induced DNA damage in aquatic organisms: potential environmental impact

International Nuclear Information System (INIS)

Haeder, Donat-P.; Sinha, Rajeshwar P.

2005-01-01

Continuing depletion of stratospheric ozone and subsequent increases in deleterious ultraviolet (UV) radiation at the Earth's surface have fueled the interest in its ecological consequences for aquatic ecosystems. The DNA is certainly one of the key targets for UV-induced damage in a variety of aquatic organisms. UV radiation induces two of the most abundant mutagenic and cytotoxic DNA lesions, cyclobutane pyrimidine dimers (CPDs) and pyrimidine pyrimidone photoproducts (6-4PPs) and their Dewar valence isomers. However, aquatic organisms have developed a number of repair and tolerance mechanisms to counteract the damaging effects of UV on DNA. Photoreactivation with the help of the enzyme photolyase is one of the most important and frequently occurring repair mechanisms in a variety of organisms. Excision repair, which can be distinguished into base excision repair (BER) and nucleotide excision repair (NER), also play an important role in DNA repair in several organisms with the help of a number of glycosylases and polymerases, respectively. In addition, mechanisms such as mutagenic repair or dimer bypass, recombinational repair, cell-cycle checkpoints, apoptosis and certain alternative repair pathways are also operative in various organisms. This review deals with the UV-induced DNA damage and repair in a number of aquatic organisms as well as methods of detecting DNA damage

Comparison of photospheric electric current and ultraviolet and x-ray emission in a solar active region

International Nuclear Information System (INIS)

Haisch, B.M.; Bruner, M.E.; Hagyard, M.J.; Bonnet, R.M.; NASA, Marshall Space Flight Center, Huntsville, AL; ESA, Paris, France)

1986-01-01

This paper presents an extensive set of coordinated observations of a solar active region, taking into account spectroheliograms obtained with the aid of the Solar Maximum Mission (SMM) Ultraviolet Spectrometer Polarimeter (UVSP) instrument, SMM soft x-ray polychromator (XRP) raster maps, and high spatial resolution ultraviolet images of the sun in Lyman-alpha and in the 1600 A continuum. These data span together the upper solar atmosphere from the temperature minimum to the corona. The data are compared to maps of the inferred photospheric electric current derived from the Marshall Space Flight Center (MSFC) vector magnetograph observations. Some empirical correlation is found between regions of inferred electric current density and the brightest features in the ultraviolet continuum and to a lesser extent those seen in Lyman-alpha within an active region. 29 references

Solar minimum Lyman alpha sky background observations from Pioneer Venus orbiter ultraviolet spectrometer - Solar wind latitude variation

Science.gov (United States)

Ajello, J. M.

1990-01-01

Measurements of interplanetary H I Lyman alpha over a large portion of the celestial sphere were made at the recent solar minimum by the Pioneer Venus orbiter ultraviolet spectrometer. These measurements were performed during a series of spacecraft maneuvers conducted to observe Halley's comet in early 1986. Analysis of these data using a model of the passage of interstellar wind hydrogen through the solar system shows that the rate of charge exchange with solar wind protons is 30 percent less over the solar poles than in the ecliptic. This result is in agreement with a similar experiment performed with Mariner 10 at the previous solar minimum.

An Ultraviolet Optical Wireless Sensor Network in Multi-scattering Channels

Science.gov (United States)

Kedar, Debbie; Arnon, Shlomi

2006-10-01

Networks of wirelessly communicating sensors are a promising technology for future data-gathering systems in both civilian and military applications including medical and environmental monitoring and surveillance, home security and industry. Optical wireless communication is a potential solution for the links, particularly thanks to the small and lightweight hardware and low power consumption. A noteworthy feature of optical wireless communication at ultraviolet wavelengths is that scattering of radiation by atmospheric particles is significant, so that the backscattering of light by these particles can function as a vehicle of communication as if numerous tiny reflecting mirrors were placed in the atmosphere. Also, almost no solar radiation penetrates the atmosphere in this spectral band, which is hence called the solar blind ultraviolet spectrum, so that very large field-of-view receivers can be used. In this paper we present a model of a non-line-of-sight (NLOS) optical wireless sensor network operating in the solar blind ultraviolet spectrum. The system feasibility is evaluated and found to facilitate miniature operational sensor networks. The problem of multi-access interference is addressed and the possibility of overcoming it using WDM diversity methods is investigated.

Occupational exposure to solar radiation in Australia: who is exposed and what protection do they use?

Science.gov (United States)

Carey, Renee N; Glass, Deborah C; Peters, Susan; Reid, Alison; Benke, Geza; Driscoll, Timothy R; Fritschi, Lin

2014-02-01

Solar ultraviolet radiation (UVR) exposure is widely recognised as a leading cause of skin cancer, with outdoor workers being particularly at risk. Little is known on a national level about how many workers are exposed to solar radiation, the circumstances in which they are exposed, or their use of protective measures. The Australian Work Exposures Study (AWES) was a cross-sectional telephone survey of 5,023 Australian workers aged 18 to 65. A subset of 1,113 respondents who indicated they worked outdoors was asked about their exposure to solar radiation in terms of the amount of time they spent working outdoors, their working location and their use of sun protective measures. A total of 1,100 respondents (22% overall) were assessed as being exposed to solar radiation at work. Exposure was more likely among males and those residing in lower socioeconomic and regional areas. Sun protection was used by 95% of the respondents, although the level of protection varied among workers, with only 8.7% classified as fully protected. This study provides valuable information regarding solar exposure that has not previously been available. The results of this study will inform strategies for risk reduction. © 2014 The Authors. ANZJPH © 2014 Public Health Association of Australia.

Experimental study of carbon materials behavior under high temperature and VUV radiation: Application to Solar Probe+ heat shield

International Nuclear Information System (INIS)

Eck, J.; Sans, J.-L.; Balat-Pichelin, M.

2011-01-01

The aim of the Solar Probe Plus (SP+) mission is to understand how the solar corona is heated and how the solar wind is accelerated. To achieve these goals, in situ measurements are necessary and the spacecraft has to approach the Sun as close as 9.5 solar radii. This trajectory induces extreme environmental conditions such as high temperatures and intense Vacuum Ultraviolet radiation (VUV). To protect the measurement and communication instruments, a heat shield constituted of a carbon material is placed on the top of the probe. In this study, the physical and chemical behavior of carbon materials is experimentally investigated under high temperatures (1600-2100 K), high vacuum (10 -4 Pa) and VUV radiation in conditions near those at perihelion for SP+. Thanks to several in situ and ex situ characterizations, it was found that VUV radiation induced modification of outgassing and of mass loss rate together with alteration of microstructure and morphology.

Effects of ultraviolet radiation on photosynthetic performance and N2 fixation in Trichodesmium erythraeum IMS 101

Directory of Open Access Journals (Sweden)

X. Cai

2017-10-01

Full Text Available Biological effects of ultraviolet radiation (UVR; 280–400 nm on marine primary producers are of general concern, as oceanic carbon fixers that contribute to the marine biological CO2 pump are being exposed to increasing UV irradiance due to global change and ozone depletion. We investigated the effects of UV-B (280–320 nm and UV-A (320–400 nm on the biogeochemically critical filamentous marine N2-fixing cyanobacterium Trichodesmium (strain IMS101 using a solar simulator as well as under natural solar radiation. Short exposure to UV-B, UV-A, or integrated total UVR significantly reduced the effective quantum yield of photosystem II (PSII and photosynthetic carbon and N2 fixation rates. Cells acclimated to low light were more sensitive to UV exposure compared to high-light-grown ones, which had more UV-absorbing compounds, most likely mycosporine-like amino acids (MAAs. After acclimation under natural sunlight, the specific growth rate was lower (by up to 44 %, MAA content was higher, and average trichome length was shorter (by up to 22 % in the full spectrum of solar radiation with UVR, than under a photosynthetically active radiation (PAR alone treatment (400–700 nm. These results suggest that prior shipboard experiments in UV-opaque containers may have substantially overestimated in situ nitrogen fixation rates by Trichodesmium, and that natural and anthropogenic elevation of UV radiation intensity could significantly inhibit this vital source of new nitrogen to the current and future oligotrophic oceans.

Online educative activities for solar ultraviolet radiation based on measurements of cloud amount and solar exposures.

Science.gov (United States)

Parisi, A V; Downs, N; Turner, J; Amar, A

2016-09-01

A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermoluminescent monitoring of the solar ultraviolet radiation with KCl: Eu2+ crystals

International Nuclear Information System (INIS)

Chernov, V.; Melendrez, R.; Barboza F, M.

2000-01-01

In this work it has been investigating the Tl properties of KCl: Eu 2+ subjected to solar direct radiation. Also it was realized irradiation with the Deuterium and Xenon lamps. It was used a set of filters and a Katos monochromator 0.25 M to determine the spectral response to Tl peaks and a study of them with respect to the duration of the Sun irradiation. After of the Sun irradiation the Tl curves show several peaks between the ambient temperature and 673 K. The relation between peaks depends strongly of the irradiation time and the different solar light wavelength. It is possible to divide the Tl peaks in two groups. The first one (T 473 K) is not too sensitive but is more stable under optical whitening. Here the obtained results are discussed with respect to UV dosemeters development for environment which facilitate to obtain direct measurements of the UV index. (Author)

The influence of the solar radiation model on the calcutated solar radiation from a horizontal surface to a tilted surface

DEFF Research Database (Denmark)

Andersen, Elsa; Lund, Hans; Furbo, Simon

2004-01-01

Measured solar radiation data are most commonly available as total solar radiation on a horizontal surface. When using solar radiation measured on horizontal to calculate the solar radiation on tilted surfaces and thereby the thermal performance of different applications such as buildings and solar...... heating systems, different solar radiation models can be used. The calculation of beam radiation from a horizontal surface to a tilted surface can be done exactly whereas different solar radiation models can calculate the sky diffuse radiation. The sky diffuse radiation can either be assumed evenly...... in the calculation. The weather data are measured at the solar radiation measurement station, SMS at the Department of Civil Engineering at the Technical University of Denmark. In this study the weather data are combined with solar collector calculations based on solar collector test carried out at Solar Energy...

Cytogenetic, cellular, and developmental responses in antarctic sea urchins (Sterechinus neumayeri) following laboratory ultraviolet-B and ambient solar radiation exposures

International Nuclear Information System (INIS)

Anderson, S.; Hoffman, J.; Wild, G.; Bosch, I.; Karentz, D.

1993-01-01

Increasing ultraviolet-B radiation as a consequence of springtime ozone depletion, could harm antarctic ecosystems. This study uses several techniques for studying genotoxic effects to evaluate UV-B effects in sea urchins from Antarctica. 6 refs., 2 figs

Utilization of ultraviolet radiation of cold hollow cathode discharge plasma for water disinfection

International Nuclear Information System (INIS)

Soloshenko, I.O.; Bazhenov, V.Yu.; Khomych, V.O.; Tsiolko, V.V.; Potapchenko, N.G.; Goncharuk, V.V.

2006-01-01

We study the possibility to use the ultraviolet radiation of a hollow cathode discharge plasma for water disinfection. We have performed the comparative experiments on the influence of ultraviolet radiation of the mentioned discharge plasma, as well as that of a standard low pressure mercury lamp

Mutation induction by 365-nm radiation and far-ultraviolet light in Escherichia coli differing in near- and far-ultraviolet light sensitivity

International Nuclear Information System (INIS)

Leonardo, J.M.; Reynolds, P.R.; Tuveson, R.W.

1984-01-01

The his-4 locus derived from Escherichia coli strain AB1157 has been transduced into 4 E. coli strains that exhibit all 4 possible combinations of genes controlling sensitivity to near-ultraviolet light (nur versus nur + ) and far-ultraviolet light (uvrA6 versus uvrA + ). The 4 strains exhibited the predicted sensitivity to 254-nm radiation based on the sensitivity of the parent strains from which they were derived and the frequency of his + mutations predicted from experiments with AB1157 from which the his-4 locus was derived. When the 4 strains were treated with 365-nm radiation, they exhibited the predicted sensitivity based on the near-ultraviolet light sensitivity of the strains from which they were derived while his + mutations were undetectable with the 4 strains as well as with strain AB1157. When treated with 365-nm radiation, cells of a WP2sub(s) strain (a derivative of B/r transduced to his-4) plated on semi-enriched medium prepared with casamino acids did not yield induced mutations, whereas plating on semi-enriched medium prepared with nutrient broth did yield mutants at both the his-4 and trp loci at frequencies at least an order of magnitude lower than that observed with far-ultraviolet light. The induction of nutritionally independent mutants by 365-nm radiation is strongly dependent on the supplement used for semi-enrichment. When compared at equivalent survival levels, mutant frequencies are significantly less following 365-nm radiation when compared with far-ultraviolet radiation. (Auth.)

Solar Ultraviolet-B radiation monitoring in Khorram Abad city in Iran

International Nuclear Information System (INIS)

Gholami, M.; Yoosefi, L.

2009-01-01

The increasing evidences show that global depletion of stratospheric ozone layer is caused by pollutant and growing incidence of the skin cancer and cataract is related to the amounts of solar UV radiation reaching the earth's surface. Therefore, the main driving force behind such efforts has been the lack of an appropriate network in scope monitoring of the terrestrial UV radiation. Materials and Methods: The present work was performed at Khorram Abad province, Lorestan, Iran. Khorram Abad (48 d egree ' ,21' E and 30 d egree , 23' N) is approximately 1171m above the mean sea level. UV radiation was measured using a UV-Biometer Model 501, from November 2005 till November 2006. Results: Hourly average UV- index, the effective power and other parameters such as effective UV dose have been m oderate f rom April until the end of August 2006 and very low from November till January 2006. However, in some days, the maximum UVI was in the range of H igh , especially in May. Conclusion: It was observed that the monthly average hourly UV index values in Khorram Abad were never at the extreme range. Chronic UVB exposure could be the major cause of eye's and skin disease in months from April to August, during which most people's activities were performed outdoor in the province of Lorestan.

Investigating work-related neoplasia associated with solar radiation.

Science.gov (United States)

Turner, S; Forman, S D; McNamee, R; Wilkinson, S M; Agius, R

2015-01-01

Both solar and non-solar exposures associated with occupation and work tasks have been reported as skin carcinogens. In the UK, there are well-established surveillance schemes providing relevant information, including when exposures took place, occupation, location of work and dates of symptom onset and diagnosis. To add to the evidence on work-related skin neoplasia, including causal agents, geographical exposure and time lag between exposure and diagnosis. This study investigated incident case reports of occupational skin disease originating from clinical specialists in dermatology reporting to a UK-wide surveillance scheme (EPIDERM) by analysing case reports of skin neoplasia from 1996 to 2012 in terms of diagnosis, employment, suspected causal agent and symptom onset. The suspected causal agent was 'sun/sunlight/ultraviolet light' in 99% of the reported work-related skin neoplasia cases. Most cases reported (91%) were in males, and the majority (62%) were aged over 65 at the time of reporting. More detailed information on exposure was available for 42% of the cases, with the median time from exposure to symptom onset ranging from 44 (melanoma) to 57 (squamous cell carcinoma) years. Irrespective of diagnostic category, the median duration of exposure to 'sun/sunlight/ultraviolet light' appeared longer where exposures occurred in the UK (range 39-51 years) rather than outside the UK (range 2.5-6.5 years). It is important to provide effective information about skin protection to workers exposed to solar radiation, especially to outdoor workers based outside the UK. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The use of shore wave ultraviolet radiation for disinfection in operating rooms

International Nuclear Information System (INIS)

Baanrud, H.; Moan, J.

1999-01-01

Over a number of years short wave ultraviolet radiation (UVC;200-280 nm) has been used to disinfect air and surfaces in operating rooms, patient rooms and laboratories, as well as air in ventilation ducts. Despite the well-documented effect of ultraviolet radiation on air quality, this technology has been relatively little used. One advantage of this method is that the UVC sources ensure a continuous reduction in the number of airborne microorganisms that are generated all the time. There are, however, some disadvantages with this method. Human exposure to ultraviolet C may cause keratoconjunctivitis and erythema and requires protection of the skin and the eyes of people exposed to levels above recommended exposure limits. However, by enclosing the UVC sources or by irradiation in the absence of human activity, human exposure is eliminated. These and other aspects concerning the use of short wave ultraviolet radiation as a disinfection agent in operating rooms are discussed in this article

Coordinated weather balloon solar radiation measurements during a solar eclipse.

Science.gov (United States)

Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

2016-09-28

Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.

A comparison of ultraviolet radiation measured at an arctic and an alpine site

International Nuclear Information System (INIS)

Ambach, W.; Blumthaler, M.; Wendler, G.

1991-01-01

Ultraviolet radiation contributes relatively little energy to the solar spectrum; however, it is very important because it is biologically very active. Measurements were carried out at a high altitude station in Switzerland (jungfraujoch 3576 m), and at a high altitude station in Alaska (Fairbanks 64.82°N) with identical instrumentation. For all season the UV flux for Jungfraujoch was larger than for Fairbanks. In summer the differences between the stations were less pronounced because the lower solar elevation is compensated by a longer day length. In winter the differences are more severe. For both stations the authors find an increased relative intensity of the UV (UV/Global) with increasing cloudiness, while the absolute values decreased with increasing cloudiness. This shows that the clouds absorb more in the near IR than in the UV region of the solar spectrum. For Fairbanks, the UV values in spring were substantially higher (mean value 18%) than for identical solar elevations after summer solstice. Cloudiness could not account for this, because the authors also observed differences for clear sky conditions. A simple model was developed, which took multiple reflections of the highly reflecting snow cover in spring into account, which correctly explained 83% of the observed differences. (author)

Solar cell radiation handbook

Science.gov (United States)

Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.

1982-01-01

The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

The Physics and Diagnostic Potential of Ultraviolet Spectropolarimetry

Science.gov (United States)

Trujillo Bueno, Javier; Landi Degl'Innocenti, Egidio; Belluzzi, Luca

2017-09-01

The empirical investigation of the magnetic field in the outer solar atmosphere is a very important challenge in astrophysics. To this end, we need to identify, measure and interpret observable quantities sensitive to the magnetism of the upper chromosphere, transition region and corona. This paper provides an overview of the physics and diagnostic potential of spectropolarimetry in permitted spectral lines of the ultraviolet solar spectrum, such as the Mg ii h and k lines around 2800 Å, the hydrogen Lyman-α line at 1216 Å, and the Lyman-α line of He ii at 304 Å. The outer solar atmosphere is an optically pumped vapor and the linear polarization of such spectral lines is dominated by the atomic level polarization produced by the absorption and scattering of anisotropic radiation. Its modification by the action of the Hanle and Zeeman effects in the inhomogeneous and dynamic solar atmosphere needs to be carefully understood because it encodes the magnetic field information. The circular polarization induced by the Zeeman effect in some ultraviolet lines (e.g., Mg ii h & k) is also of diagnostic interest, especially for probing the outer solar atmosphere in plages and more active regions. The few (pioneering) observational attempts carried out so far to measure the ultraviolet spectral line polarization produced by optically pumped atoms in the upper chromosphere, transition region and corona are also discussed. We emphasize that ultraviolet spectropolarimetry is a key gateway to the outer atmosphere of the Sun and of other stars.

High Data Rate Optical Wireless Communications Based on Ultraviolet Band

KAUST Repository

Sun, Xiaobin

2017-01-01

Optical wireless communication systems based on ultraviolet (UV)-band has a lot inherent advantages, such as low background solar radiation, low device dark noise. Besides, it also has small restrictive requirements for PAT (pointing, acquisition

Effective polycrystalline sensor of ultraviolet radiation

Directory of Open Access Journals (Sweden)

S.Yu. Pavelets

2017-10-01

Full Text Available Deposition of special thin layers with high and low resistance in space charge region of surface barrier photoconverters based on the p-Cu1.8S/n-CdS structure leads to a sufficient increase in photosensitivity and decrease in dark tunneling-recombination current. Highly efficient and stable polycrystalline photoconverters of ultraviolet radiation based on polycrystalline CdS have been obtained. Electrical and photoelectric properties have been investigated, and the main operational parameters of ultraviolet sensors have been adduced. The reasons for high stability of the parameters inherent to the p-Cu1.8S/n-CdS sensors are as follows: the absence of impurity components additionally doped to the barrier structure and stability of the photocurrent photoemission component.

Pollen and spores as a passive monitor of ultraviolet radiation

Directory of Open Access Journals (Sweden)

Wesley Toby Fraser

2014-04-01

Full Text Available Sporopollenin is the primary component of the outer walls of pollen and spores. The chemical composition of sporopollenin is responsive to levels of ultraviolet (UV radiation exposure, via a concomitant change in the concentration of phenolic compounds. This relationship offers the possibility of using fossil pollen and spore chemistry as a novel proxy for past UV flux. Phenolic compounds in sporopollenin can be quantified using Fourier Transform infrared spectroscopy. The high potential for preservation of pollen and spores in the geologic record, and the conservative nature of sporopollenin chemistry across the land plant phylogeny, means that this new proxy has the potential to reconstruct UV flux over much longer timescales than has previously been possible. This new tool has important implications for understanding the relationship between UV flux, solar insolation and climate in the past, as well as providing a possible means of assessing paleoaltitude, and ozone thickness.

Ultraviolet radiation response of two heterotropy Antarctic marine bacterial; Respuesta a la radiacion ultravioleta de dos cepas bacterianas marinas heterotrofas antarticas

Energy Technology Data Exchange (ETDEWEB)

Hernandez, Edgardo A [Buenos Aires Univ. (Argentina). Facultad de Farmacia y Bioquimica; Ferreyra, Gustavo A; Mac Cormack, Walter P [Direccion Nacional del Antartico, Buenos Aires (Argentina). Instituto Antartico Argentino

2004-07-01

Two Antarctic marine bacterial strains, were exposed to different irradiance of ultraviolet (UV) solar radiation using several experimental protocols and interferential filters. Results showed that both, UV-A and UV-B radiation produce deleterious effects on two tested bacterial strains. The mortality values under UVB treatments were higher than those observed under UVA treatments. UVvi strain proved to be more resistant to UV radiation than the UVps strain. (author) [Spanish] Dos cepas marinas antarticas fueron expuestas a diferentes irradiancias de radiacion solar ultravioleta (UV) utilizando diferentes protocolos experimentales y filtros interferenciales. Los resultados mostraron que tanto la radiacion UV-A como UV-B produce efectos deletereos sobre las dos cepas bacterianas analizadas. Los valores de mortalidad bajo tratamiento UV-B fueron mayores que los observados bajo tratamiento UV-A. La cepa UVvi mostro mayor resistencia a la radiacion UV que la cepa UVps. (autor)

A comparison of photospheric electric current and ultraviolet and X-ray emission in a solar active region

Science.gov (United States)

Haisch, B. M.; Bruner, M. E.; Hagyard, M. J.; Bonnet, R. M.

1986-01-01

This paper presents an extensive set of coordinated observations of a solar active region, taking into account spectroheliograms obtained with the aid of the Solar Maximum Mission (SMM) Ultraviolet Spectrometer Polarimeter (UVSP) instrument, SMM soft X-ray polychromator (XRP) raster maps, and high spatial resolution ultraviolet images of the sun in Lyman-alpha and in the 1600 A continuum. These data span together the upper solar atmosphere from the temperature minimum to the corona. The data are compared to maps of the inferred photospheric electric current derived from the Marshall Space Flight Center (MSFC) vector magnetograph observations. Some empirical correlation is found between regions of inferred electric current density and the brightest features in the ultraviolet continuum and to a lesser extent those seen in Lyman-alpha within an active region.

Effects of ultraviolet-B radiation on plants during mild water stress, 4: The insensitivity of soybean internal water relations to ultraviolet-B radiation

International Nuclear Information System (INIS)

Teramura, A.H.; Forseth, I.N.; Lydon, J.

1984-01-01

The combined effects of ultraviolet-B (UV-B, 280–320 nm) radiation and water stress were investigated on the water relations of greenhouse grown soybean [Glycine max (L.) Merr. cv. Essex]. On a weighted (Caldwell 1971), total daily dose basis, plants received either 0 or 3 000 effective J m 2 UV-B BE supplied by filtered FS-40 sunlamps. The latter dose simulated the solar UV-B radiation anticipated at College Park, Maryland, U.S.A. (39°N latitude) in the event that the global stratospheric ozone column is reduced by 25%. Plants were either well-watered or preconditioned by drought stress cycles. Diurnal measurements of water potential and stomatal conductance were made on the youngest fully expanded leaf. Various internal water relations parameters were determined for detached leaves. Plants were monitored before, during and after water stress. There were no significant differences in leaf water potential or stomatal conductance between treatments before plants were preconditioned to water stress. However, drought stress resulted in significantly lower midday and afternoon leaf water potentials and lower leaf conductances as compared to well-watered plants. UV-B radiation had no additional effect on leaf water potential; however, UV did result in lower leaf conductances in plants preconditioned to water stress. Turgid weight:dry weight ratio, elastic modulus, bound water and relative water content were unaffected by UV-B radiation. Osmotic potentials at full and zero turgor were significantly lower in the drought stressed treatments as compared to well-watered plants. (author)

MgII Observations Using the MSFC Solar Ultraviolet Magnetograph

Science.gov (United States)

West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

2011-01-01

This paper will describe the scientific goals of our sounding rocket program, the Solar Ultraviolet Magnetograph Investigation (SUMI). This paper will present a brief description of the optics that were developed to meet SUMI's scientific goals, discuss the spectral, spatial and polarization characteristics of SUMI s optics, describe SUMI's flight which was launched 7/30/2010, and discuss what we have learned from that flight.

Solar storms; Tormentas solares

Energy Technology Data Exchange (ETDEWEB)

Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

2016-08-01

Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

The minimal melanogenesis dose/minimal erythema dose ratio declines with increasing skin pigmentation using solar simulator and narrowband ultraviolet B exposure

DEFF Research Database (Denmark)

Ravnbak, Mette H; Philipsen, Peter A; Wulf, Hans Christian

2010-01-01

To investigate the relation between pre-exposure skin pigmentation and the minimal melanogenesis dose (MMD)/minimal erythema dose (MED) ratio after a single narrowband ultraviolet B (nUVB) and solar simulator (Solar) exposure.......To investigate the relation between pre-exposure skin pigmentation and the minimal melanogenesis dose (MMD)/minimal erythema dose (MED) ratio after a single narrowband ultraviolet B (nUVB) and solar simulator (Solar) exposure....

Epigallocatechin-3-gallate on Melanogenesis in Ultraviolet A ...

African Journals Online (AJOL)

compared to blank (control) which was neither treated by UVA nor by EGCG. TEM showed that UVA induced the formation of ... Biological Engineering Technology Co., Ltd,. (Shanghai, China). PA102 Bradford protein assay kit ..... Sliney DH. Estimating the solar ultraviolet radiation exposure to an intraocular eye implant.

Human exposure to ultraviolet radiation

International Nuclear Information System (INIS)

Bernhardt, J.H.; Matthes, R.

1987-01-01

Ultraviolet radiation is that part of the electromagnetic spectrum located between the softest ionizing radiation and visible radiation. The lower limit of 100 nm is equivalent to photon energies of 12.4 eV, which corresponds approximately to the limit for the production of ionization in biologically important materials. A historical subdividing of the UV-region takes some of the biological effects into account. In this arrangement the range 400-315 nm, the so-called black light region, is called UV-A. In this wavelength region, fluorescence can be induced in many substances. UV-B covers the range 315-280 nm (the skin erythemal region). Most of the biologically active and potentially harmful UV from the sun reaching the surface of the earth is part of this spectral region. UV-C includes the radiation of wavelengths less than 280 nm (the germicidal region). It should be noted that this classification is somewhat arbitrary, and today it is more usual to evaluate the biological effectiveness of the whole UV-range from 200 to 400 nm

Ultraviolet Radiation Dose National Standard of México

Science.gov (United States)

Cardoso, R.; Rosas, E.

2006-09-01

We present the Ultraviolet (UV) Radiation Dose National Standard for México. The establishment of this measurement reference at Centro Nacional de Metrología (CENAM) eliminates the need of contacting foreign suppliers in the search for traceability towards the SI units when calibrating instruments at 365 nm. Further more, the UV Radiation Dose National Standard constitutes a highly accurate and reliable source for the UV radiation dose measurements performed in medical and cosmetic treatments as in the the food and pharmaceutics disinfection processes, among other.

Null bactericidal effect of ultraviolet radiation emitted by LEDs.

Directory of Open Access Journals (Sweden)

Francisco Alcántara Muñoz

2016-11-01

Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review.

Science.gov (United States)

Sklar, Lindsay R; Almutawa, Fahad; Lim, Henry W; Hamzavi, Iltefat

2013-01-01

The effects of ultraviolet radiation, visible light, and infrared radiation on cutaneous erythema, immediate pigment darkening, persistent pigment darkening, and delayed tanning are affected by a variety of factors. Some of these factors include the depth of cutaneous penetration of the specific wavelength, the individual skin type, and the absorption spectra of the different chromophores in the skin. UVB is an effective spectrum to induce erythema, which is followed by delayed tanning. UVA induces immediate pigment darkening, persistent pigment darkening, and delayed tanning. At high doses, UVA (primarily UVA2) can also induce erythema in individuals with skin types I-II. Visible light has been shown to induce erythema and a tanning response in dark skin, but not in fair skinned individuals. Infrared radiation produces erythema, which is probably a thermal effect. In this article we reviewed the available literature on the effects of ultraviolet radiation, visible light, and infrared radiation on the skin in regards to erythema and pigmentation. Much remains to be learned on the cutaneous effects of visible light and infrared radiation.

Availability of solar radiation and standards for solar access

Energy Technology Data Exchange (ETDEWEB)

Casabianca, G.A.; Evans, J.M. [Research Centre Habitat and Energy, Facultad de Arquitectura, Diseno y Urbanismo, Universidad de Buenos Aires, Capital Federal (Argentina)

1997-12-31

In southern Argentina, a region between latitudes 38 deg C and 55 deg C S, the heating demand in the residential sector is high while the availability of solar radiation is limited. A new proposal for solar access standards has been developed, taking into account the climatic conditions of each location, the effective availability of solar radiation and the direct sunlight requirements. This study analyses the climatic conditions for the Patagonia, relating heating demand and solar radiation availability in different sites, and presents the development of new sunlight standards that respond to these regional conditions. As a result of this study, the new Argentine standard TRAM 11.603 includes new conditions to protect solar access and provide design recommendations. (orig.) 4 refs.

Fluctuation characteristics of solar radiation in crop cultivation

International Nuclear Information System (INIS)

Hayashi, S.; Suzuki, H.

1996-01-01

The objective of this study was to clarify the fluctuation of solar radiation for long and short periods, which is very crucial for plant growth. Data obtained from a meteorological observatory were used to investigate solar radiation and sunshine duration for a long period. For a short period, observation of global solar radiation and sky solar radiation were conducted in a glass house and at an open field. (1) Yearly average percentage of solar radiation at Kagawa from 1973 to 1994 was 44.3%, and its coefficient of variation was 3.9%. The percentage of possible sunshine and the coefficient were larger than those of solar radiation, 47.3% and 56% respectively. (2) Percentage of possible solar radiation and percentage of possible sunshine showed seasonal variation. Those coefficients of variation both increased exponentially with cloud amount. (3) Variations of global solar radiation and direct solar radiation were more remarkable in the glass house than those in the open field, while variations of sky solar radiation were small in the house and at the open field. (4) The fluctuation of solar radiation observed every 5 minutes was presented as the difference of radiation, present value minus the preceding value. The difference was positive in the morning, negative in the afternoon at the open field. In the house both positive and negative values were obtained the whole day. (5) Diurnal variation of ratio of direct solar radiation to sky solar radiation showed a parabolic effect, whereas it had irregular and large fluctuations at the open field

The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries

International Nuclear Information System (INIS)

Kaidbey, K.H.; Witkowski, T.A.; Kligman, A.M.

1982-01-01

Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene

Daily, seasonal, and latitudinal variations in solar ultraviolet A and B radiation in relation to vitamin D production and risk for skin cancer.

Science.gov (United States)

Grigalavicius, Mantas; Moan, Johan; Dahlback, Arne; Juzeniene, Asta

2016-01-01

Solar ultraviolet (UV) radiation varies with latitude, time of day, and season. Both spectral UV composition and ambient UV dose lead to different health outcomes at different latitudes. Finding the optimal time for sun exposure, whereby the positive effects of UV exposure (vitamin D) are facilitated and the negative effects (skin cancer, photoimmunosuppression) avoided are the most important consideration in modern skin cancer prevention programs. This paper focuses on the latitude dependency of UVB, UVA, vitamin D production, and skin cancer risk in Caucasians. Biologically effective UVB (280-315 nm) and UVA (315-400 nm) doses were calculated using radiative transfer models with appropriate climatologic data for selected locations. Incidences of squamous cell carcinoma (SCC) and cutaneous melanoma (CM) were retrieved from cancer registries and published articles. Annual doses of UVA radiation decrease much less with increasing latitude than annual doses of UVB. Incidences of CM also decrease less steeply with increasing latitude than incidences of SCC. As SCC is caused mainly by UVB, these observations support the assumption that UVA plays an important role in the development of CM. The variations in UVA (relevant to CM) and UVB (relevant to vitamin D production) over 1 day differ: the UVB : UVA ratio is maximal at noon. The best way to obtain a given dose of vitamin D with minimal carcinogenic risk is through a non-burning exposure in the middle of the day, rather than in the afternoon or morning. © 2015 The International Society of Dermatology.

Key issues of ultraviolet radiation of OH at high altitudes

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing [State Key Laboratory of High Temperature Gasdynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

2014-12-09

Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}Σ{sup +}→X{sup 2}Π ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

The Xenon Test Chamber Q-SUN® for testing realistic tolerances of fungi exposed to simulated full spectrum solar radiation.

Science.gov (United States)

Dias, Luciana P; Araújo, Claudinéia A S; Pupin, Breno; Ferreira, Paulo C; Braga, Gilberto Ú L; Rangel, Drauzio E N

2018-06-01

The low survival of insect-pathogenic fungi when used for insect control in agriculture is mainly due to the deleterious effects of ultraviolet radiation and heat from solar irradiation. In this study, conidia of 15 species of entomopathogenic fungi were exposed to simulated full-spectrum solar radiation emitted by a Xenon Test Chamber Q-SUN XE-3-HC 340S (Q-LAB ® Corporation, Westlake, OH, USA), which very closely simulates full-spectrum solar radiation. A dendrogram obtained from cluster analyses, based on lethal time 50 % and 90 % calculated by Probit analyses, separated the fungi into three clusters: cluster 3 contains species with highest tolerance to simulated full-spectrum solar radiation, included Metarhizium acridum, Cladosporium herbarum, and Trichothecium roseum with LT 50  > 200 min irradiation. Cluster 2 contains eight species with moderate UV tolerance: Aschersonia aleyrodis, Isaria fumosorosea, Mariannaea pruinosa, Metarhizium anisopliae, Metarhizium brunneum, Metarhizium robertsii, Simplicillium lanosoniveum, and Torrubiella homopterorum with LT 50 between 120 and 150 min irradiation. The four species in cluster 1 had the lowest UV tolerance: Lecanicillium aphanocladii, Beauveria bassiana, Tolypocladium cylindrosporum, and Tolypocladium inflatum with LT 50  solar radiation before. We conclude that the equipment provided an excellent tool for testing realistic tolerances of fungi to full-spectrum solar radiation of microbial agents for insect biological control in agriculture. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Effects of emollients on ultraviolet-radiation-induced erythema of the skin

International Nuclear Information System (INIS)

Schleider, N.R.; Moskowitz, R.S.; Cort, D.H.; Horwitz, S.N.; Frost, P.

1979-01-01

Several commonly used emollients were studied as to their effectiveness in absorbing and filtering erythema-causing ultraviolet radiation in the 280 to 315 nm range (UVB). Planter's Peanut Oil (Standard Brands) and Mazola Corn Oil (Best Foods Inc.) had no effect; Alpha Keri Bath Oil (Westwood Pharmaceuticals), mineral oil, and Johnson's Baby Oil (Johnson and Johnson Co) had minimal effects. Vaseline Petroleum Jelly (Chesebrough-Ponds Inc.), petrolatum, and hydrophilic ointment substantially reduced the erythema that was induced by exposure to low doses of UVB radiation. Therefore, these emollients may interfere with the therapeutic effects of the ultraviolet radiation component of the Goeckerman treatment when it is administered in low doses to patients with psoriasis

Thermoluminescent phosphors for ultraviolet radiation dosimetry - a review

International Nuclear Information System (INIS)

Nagpal, J.S.

2001-01-01

Intrinsic TL response of CaSO 4 , CaF 2 , Al 2 O 3 (Si,Ti), Mg 2 SiO 4 : Tb and lamp phosphors to ultraviolet radiation is reviewed. Taking into consideration the characteristics such as afterglow at RT, rate/flux dependence, linearity of response, useful range, spectral dependence and effect of sequential/tandem UV exposures CaF 2 :Eu 2+ is an ideal TL dosemeter for UV radiation dosimetry. (author)

Multiple Roles for UV RESISTANCE LOCUS8 in Regulating Gene Expression and Metabolite Accumulation in Arabidopsis under Solar Ultraviolet Radiation1[W][OA

Science.gov (United States)

Morales, Luis O.; Brosché, Mikael; Vainonen, Julia; Jenkins, Gareth I.; Wargent, Jason J.; Sipari, Nina; Strid, Åke; Lindfors, Anders V.; Tegelberg, Riitta; Aphalo, Pedro J.

2013-01-01

Photomorphogenic responses triggered by low fluence rates of ultraviolet B radiation (UV-B; 280–315 nm) are mediated by the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8). Beyond our understanding of the molecular mechanisms of UV-B perception by UVR8, there is still limited information on how the UVR8 pathway functions under natural sunlight. Here, wild-type Arabidopsis (Arabidopsis thaliana) and the uvr8-2 mutant were used in an experiment outdoors where UV-A (315–400 nm) and UV-B irradiances were attenuated using plastic films. Gene expression, PYRIDOXINE BIOSYNTHESIS1 (PDX1) accumulation, and leaf metabolite signatures were analyzed. The results show that UVR8 is required for transcript accumulation of genes involved in UV protection, oxidative stress, hormone signal transduction, and defense against herbivores under solar UV. Under natural UV-A irradiance, UVR8 is likely to interact with UV-A/blue light signaling pathways to moderate UV-B-driven transcript and PDX1 accumulation. UVR8 both positively and negatively affects UV-A-regulated gene expression and metabolite accumulation but is required for the UV-B induction of phenolics. Moreover, UVR8-dependent UV-B acclimation during the early stages of plant development may enhance normal growth under long-term exposure to solar UV. PMID:23250626

Near-ultraviolet radiation-induced damage using an actinic reticuloid strain as a possible sensitive model

International Nuclear Information System (INIS)

Kralli, A.

1987-01-01

The introduction to this thesis consists of a review of current concepts regarding the effects of ultraviolet radiation on living cells. Actinic reticuloid, a disease condition for which a near-ultraviolet radiation cellular sensitivity has been proposed as an underlying cause, is described. The experimental work, the broad aim of which is to expand existing knowledge of the effects of near-ultraviolet radiation that may lead to cell lethality, has centred upon the irradiation of a normal human skin fibroblast strain, GM730, and a strain derived from an actinic reticuloid patient, AR6LO. Parts 1 and 2 examine the effects of the irradiation on both normal and actinic fibroblast sensitivities to a range of ultraviolet wavelengths. The next two sections include observations on the protective effect of Trolox-C, a vitamin E analogue and the sensitization resulting from the replacement of the irradiation medium by a deuterated one, using both normal and actinic reticuloid fibroblasts. The final part examines broad-band near- and far-ultraviolet radiation induced membrane damage by the use of radioactively labelled rubidium as a potassium analogue. (author)

Estimation of monthly solar radiation distribution for solar energy system analysis

International Nuclear Information System (INIS)

Coskun, C.; Oktay, Z.; Dincer, I.

2011-01-01

The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors. -- Research highlights: → The first study to apply global solar radiation distribution in solar system analyzes. → The first study showing global solar radiation distribution as a parameter of the solar irradiance intensity. → Time probability intensity frequency and probability power distribution do not have similar distribution patterns for each month. → There is no relation between the distribution of annual time lapse and solar energy with the intensity of solar irradiance.

Slowly varying component of extreme ultraviolet solar radiation and its relation to solar radio radiation

Science.gov (United States)

Chapman, R. D.; Neupert, W. M.

1974-01-01

A study of the correlations between solar EUV line fluxes and solar radio fluxes has been carried out. A calibration for the Goddard Space Flight Center EUV spectrum is suggested. The results are used to obtain an equation for the absolute EUV flux for several lines in the 150- to 400-A region and the total flux of 81 intense lines in the region, the 2800-MHz radio flux being used as independent variable.

Extreme Ultraviolet Solar Images Televised In-Flight with a Rocket-Borne SEC Vidicon System.

Science.gov (United States)

Tousey, R; Limansky, I

1972-05-01

A TV image of the entire sun while an importance 2N solar flare was in progress was recorded in the extreme ultraviolet (XUV) radiation band 171-630 A and transmitted to ground from an Aerobee-150 rocket on 4 November 1969 using S-band telemetry. The camera tube was a Westinghouse Electric Corporation SEC vidicon, with its fiber optic faceplate coated with an XUV to visible conversion layer of p-quaterphenyl. The XUV passband was produced by three 1000-A thick aluminum filters in series together with the platinized reflecting surface of the off-axis paraboloid that imaged the sun. A number of images were recorded with integration times between 1/30 see and 2 sec. Reconstruction of pictures was enhanced by combining several to reduce the noise.

Photokeratitis induced by ultraviolet radiation in travelers: A major health problem

Directory of Open Access Journals (Sweden)

M Izadi

2018-01-01

Full Text Available Ultraviolet (UV irradiation is one of the several environmental hazards that may cause inflammatory reactions in ocular tissues, especially the cornea. One of the important factors that affect how much ultraviolet radiation (UVR humans are exposed to is travel. Hence, traveling is considered to include a more acute UVR effect, and ophthalmologists frequently evaluate and manage the ocular manifestations of UV irradiation, including UV-induced keratitis. The purpose of this paper is to provide an evidence-based analysis of the clinical effect of UVR in ocular tissues. An extensive review of English literature was performed to gather all available articles from the National Library of Medicine PubMed database of the National Institute of Health, the Ovid MEDLINE database, Scopus, and ScienceDirect that had studied the effect of UVR on the eye and its complications, between January 1970 and June 2014. The results show that UVR at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis. Apoptosis in all layers of the cornea occurs 5 h after exposure. The effect of UVR intensity on the eye can be linked to numerous factors, including solar elevation, time of day, season, hemisphere, clouds and haze, atmospheric scattering, atmospheric ozone, latitude, altitude, longitudinal changes, climate, ground reflection, and geographic directions. The most important factor affecting UVR reaching the earth's surface is solar elevation. Currently, people do not have great concern over eye protection. The methods of protection against UVR include avoiding direct sunlight exposure, using UVR-blocking eyewear (sunglasses or contact lenses, and wearing hats. Hence, by identifying UVR intensity factors, eye protection factors, and public education, especially in travelers, methods for safe traveling can be identified.

Photokeratitis induced by ultraviolet radiation in travelers: A major health problem.

Science.gov (United States)

Izadi, M; Jonaidi-Jafari, N; Pourazizi, M; Alemzadeh-Ansari, M H; Hoseinpourfard, M J

2018-01-01

Ultraviolet (UV) irradiation is one of the several environmental hazards that may cause inflammatory reactions in ocular tissues, especially the cornea. One of the important factors that affect how much ultraviolet radiation (UVR) humans are exposed to is travel. Hence, traveling is considered to include a more acute UVR effect, and ophthalmologists frequently evaluate and manage the ocular manifestations of UV irradiation, including UV-induced keratitis. The purpose of this paper is to provide an evidence-based analysis of the clinical effect of UVR in ocular tissues. An extensive review of English literature was performed to gather all available articles from the National Library of Medicine PubMed database of the National Institute of Health, the Ovid MEDLINE database, Scopus, and ScienceDirect that had studied the effect of UVR on the eye and its complications, between January 1970 and June 2014. The results show that UVR at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis. Apoptosis in all layers of the cornea occurs 5 h after exposure. The effect of UVR intensity on the eye can be linked to numerous factors, including solar elevation, time of day, season, hemisphere, clouds and haze, atmospheric scattering, atmospheric ozone, latitude, altitude, longitudinal changes, climate, ground reflection, and geographic directions. The most important factor affecting UVR reaching the earth's surface is solar elevation. Currently, people do not have great concern over eye protection. The methods of protection against UVR include avoiding direct sunlight exposure, using UVR-blocking eyewear (sunglasses or contact lenses), and wearing hats. Hence, by identifying UVR intensity factors, eye protection factors, and public education, especially in travelers, methods for safe traveling can be identified.

Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces

Science.gov (United States)

Dever, Joyce A.; Bruckner, Eric J.; Scheiman, David A.; Stidham, Curtis R.

1994-01-01

For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.

Effects of ultraviolet-B radiation on phytoplankton - zooplankton interactions = [Effecten van ultraviolet-B straling op interacties tussen fytoplankton en zooplankton

NARCIS (Netherlands)

Lange, de H.J.

1999-01-01

The decrease in stratospheric ozone concentration has received wide attention because the ozone layer protects the earth from harmful ultraviolet-B radiation (UVB, 280-320 nm). UVB radiation is harmful for organisms, and therefore scientific research into how UVB radiation affects organisms

Predicted solar cell edge radiation effects

International Nuclear Information System (INIS)

Gates, M.T.

1993-01-01

The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

Solar radiation for Mars power systems

Science.gov (United States)

Appelbaum, Joseph; Landis, Geoffrey A.

1991-01-01

Detailed information about the solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data from which the diurnally and daily variation of the global, direct (or beam), and diffuse insolation on Mars are calculated, are presented. The radiation data are based on measured optical depth of the Martian atmosphere derived from images taken of the Sun with a special diode on the Viking Lander cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation.

A Model for Hourly Solar Radiation Data Generation from Daily Solar Radiation Data Using a Generalized Regression Artificial Neural Network

OpenAIRE

Khatib, Tamer; Elmenreich, Wilfried

2015-01-01

This paper presents a model for predicting hourly solar radiation data using daily solar radiation averages. The proposed model is a generalized regression artificial neural network. This model has three inputs, namely, mean daily solar radiation, hour angle, and sunset hour angle. The output layer has one node which is mean hourly solar radiation. The training and development of the proposed model are done using MATLAB and 43800 records of hourly global solar radiation. The results show that...

Models of diffuse solar radiation

Energy Technology Data Exchange (ETDEWEB)

Boland, John; Ridley, Barbara [Centre for Industrial and Applied Mathematics, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia); Brown, Bruce [Department of Statistics and Applied Probability, National University of Singapore, Singapore 117546 (Singapore)

2008-04-15

For some locations both global and diffuse solar radiation are measured. However, for many locations, only global is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from trigonometry, we need to have diffuse on the horizontal available. There are regression relationships for estimating the diffuse on a tilted surface from diffuse on the horizontal. Models for estimating the diffuse radiation on the horizontal from horizontal global that have been developed in Europe or North America have proved to be inadequate for Australia [Spencer JW. A comparison of methods for estimating hourly diffuse solar radiation from global solar radiation. Sol Energy 1982; 29(1): 19-32]. Boland et al. [Modelling the diffuse fraction of global solar radiation on a horizontal surface. Environmetrics 2001; 12: 103-16] developed a validated model for Australian conditions. We detail our recent advances in developing the theoretical framework for the approach reported therein, particularly the use of the logistic function instead of piecewise linear or simple nonlinear functions. Additionally, we have also constructed a method, using quadratic programming, for identifying values that are likely to be erroneous. This allows us to eliminate outliers in diffuse radiation values, the data most prone to errors in measurement. (author)

Solar and infrared radiation measurements

CERN Document Server

Vignola, Frank; Michalsky, Joseph

2012-01-01

The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

Radiations in space and global environment

International Nuclear Information System (INIS)

Oguti, Takasi

1994-01-01

It has been well known that the global environment of the earth is basically determined by the radiation equilibrium of the earth atmosphere system embedded in the solar radiation. However, the surface temperature of about 15 degC on average is much higher than that determined by the radiation equilibrium. This is due to the so-called greenhouse gases in the atmosphere such as carbon dioxide, water vapor, methane and others. Also the global environment has evolved by interacting with the living things on the earth, for example, tree oxygen by photosynthesis, and a small amount of ozone protecting living things from the fetal damage due to solar ultraviolet radiation. The solar radiation of short wavelength, that is, ultraviolet to X-ray influences atmospheric constituents, and the thermal structure and dynamics of the atmosphere through chemical reaction. The solar energetic particles produced by solar flares precipitate in the polar regions, and the nitric oxides are produced by auroral X-ray. Auroral activities accelerate particles in the magnetosphere. All these radiations cause significant global changes. Human activities increase greenhouse gases rapidly and cause global warming, and atmospheric chloro-fluoro-carbon (CFC) makes the ozone hole. Now, human activities must be modified to match the natural cycle of materials. (K.I.)

Making Ultraviolet Spectro-Polarimetry Polarization Measurements with the MSFC Solar Ultraviolet Magnetograph Sounding Rocket

Science.gov (United States)

West, Edward; Cirtain, Jonathan; Kobayashi, Ken; Davis, John; Gary, Allen

2011-01-01

This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph Investigation (SUMI) sounding rocket program. This paper will concentrate on SUMI's VUV optics, and discuss their spectral, spatial and polarization characteristics. While SUMI's first flight (7/30/2010) met all of its mission success criteria, there are several areas that will be improved for its second and third flights. This paper will emphasize the MgII linear polarization measurements and describe the changes that will be made to the sounding rocket and how those changes will improve the scientific data acquired by SUMI.

Measurement of solar radiation at the Earth's surface

Science.gov (United States)

Bartman, F. L.

1982-01-01

The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

Measurements and modeling of total solar irradiance in X-class solar flares

International Nuclear Information System (INIS)

Moore, Christopher Samuel; Chamberlin, Phillip Clyde; Hock, Rachel

2014-01-01

The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment can detect changes in the total solar irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-class solar flares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar flares presented in Woods et al., as well as an additional flare measured on 2006 December 6. The radiative outputs for both phases of these five flares are then compared to the vacuum ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-class flares. This model provides the basis for the bolometric energy estimates for the solar flares analyzed in the Emslie et al. study.

The Ultraviolet Index: a useful tool.

Science.gov (United States)

Kinney, J P; Long, C S

2000-09-01

The Ultraviolet Index was developed in the United States in 1994 following successful use of ultraviolet (UV) alerts in other countries. This daily National Weather Service prediction is a calculation which integrates five data elements to yield the amount of UV radiation impacting the surface (1m2) at solar noon in 58 of the largest US population centers. This simple numeric prediction is then categorized by the Environmental Protection Agency into five "exposure levels" with protective actions recommended for each level. This information is disseminated through the media. Daily reminders seem to affect awareness and behavior in Canada, but US surveys indicate the need for better understanding through educational graphics. Comparing the UV Index to a precipitation prediction has merit in that it links a familiar daily prediction with implied appropriate protective measures. Graphics link the ideas that "when it rains it pours and when it shines it radiates." Beginning in schools, camps, and dermatology meetings, using the rain/shine analogy, a wider exposure to the Ultraviolet Index is proposed.

Comprehensive Review of Ultraviolet Radiation and the Current Status on Sunscreens

Science.gov (United States)

Moon, Summer; Armstrong, Frank

2012-01-01

In the past, manufacturers’ labeling of sunscreen varied greatly, confusing the consumers regarding efficacy and the appropriate photoprotection provided by their products. Therefore, in June 2011, the United States Food and Drug Administration issued new guidelines for sunscreen labeling. Sunscreen products are over-the-counter drugs; therefore, they are regulated by the United States Food and Drug Administration to determine safety, efficacy, and labeling. This article discusses ultraviolet radiation and the positive and negative effects of ultraviolet radiation, provides a review of sunscreens, and discusses the new United States Food and Drug Administration regulations for sunscreens. PMID:23050030

Cosmetic and medical applications of ultraviolet radiation

International Nuclear Information System (INIS)

Diffey, B.L.

1987-01-01

The social desirability of a tanned skin is apparent and many people associate a bronzed body with good health and a sense of well-being. In Northern Europe and America the lack of long periods of sunshine has led to the establishment of the suntanning industry where artificial sources of ultraviolet radiation emitting almost entirely in the UV-A region supplement sunlight exposure

Solar UV-B radiation modulates chemical defenses against Anticarsia gemmatalis larvae in leaves of field-grown soybean.

Science.gov (United States)

Dillon, Francisco M; Chludil, Hugo D; Zavala, Jorge A

2017-09-01

Although it is well known that solar ultraviolet B (UV-B) radiation enhances plant defenses, there is less knowledge about traits that define insect resistance in field-grown soybean. Here we study the effects of solar UV-B radiation on: a) the induction of phenolic compounds and trypsin proteinase inhibitors (TPI) in soybean undamaged leaves or damaged by Anticarsia gemmatalis neonates during six days, and b) the survival and mass gain of A. gemmatalis larvae that fed on soybean foliage. Two soybean cultivars (cv.), Charata and Williams, were grown under plastic with different transmittance to solar UV-B radiation, which generated two treatments: ambient UV-B (UVB+) and reduced UV-B (UVB-) radiation. Solar UV-B radiation decreased survivorship by 30% and mass gain by 45% of larvae that fed on cv. Charata, but no effect was found in those larvae that fed on cv. Williams. TPI activity and malonyl genistin were induced by A. gemmatalis damage in both cultivars, but solar UV-B radiation and damage only synergistically increased the induction of these compounds in cv. Williams. Although TPI activity and genistein derivatives were induced by herbivory, these results did not explain the differences found in survivorship and mass gain of larvae that fed on cv. Charata. However, we found a positive association between lower larval performance and the presence of two quercetin triglycosides and a kaempferol triglycoside in foliage of cv. Charata, which were identified by HPLC-DAD/MS 2 . We conclude that exclusion of solar UV-B radiation reduce resistance to A. gemmatalis, due to a reduction in flavonol concentration in a cultivar that has low levels of genistein derivatives like cv. Charata. Copyright © 2017 Elsevier Ltd. All rights reserved.

Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

International Nuclear Information System (INIS)

Bero, M A; Abukassem, I

2009-01-01

Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

Detection of ultraviolet radiation using tissue equivalent radiochromic gel materials

Science.gov (United States)

Bero, M. A.; Abukassem, I.

2009-05-01

Ferrous Xylenol-orange Gelatin gel (FXG) is known to be sensitive to ionising radiation such as γ and X-rays. The effect of ionising radiation is to produce an increase in the absorption over a wide region of the visible spectrum, which is proportional to the absorbed dose. This study demonstrates that FXG gel is sensitive to ultraviolet radiation and therefore it could functions as UV detector. Short exposure to UV radiation produces linear increase in absorption measured at 550nm, however high doses of UV cause the ion indicator colour to fad away in a manner proportional to the incident UV energy. Light absorbance increase at the rate of 1.1% per minute of irradiation was monitored. The exposure level at which the detector has linear response is comparable to the natural summer UV radiation. Evaluating the UV ability to pass through tissue equivalent gel materials shows that most of the UV gets absorbed in the first 5mm of the gel materials, which demonstrate the damaging effects of this radiation type on human skin and eyes. It was concluded that FXG gel dosimeter has the potential to offer a simple, passive ultraviolet radiation detector with sensitivity suitable to measure and visualises the natural sunlight UV exposure directly by watching the materials colour changes.

Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

Science.gov (United States)

Austin, A.; Ballare, C. L.; Méndez, M. S.

2015-12-01

Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

Influence of rpoS mutations on the response of Salmonella enterica serovar Typhimurium to solar radiation.

Science.gov (United States)

Oppezzo, Oscar J; Costa, Cristina S; Pizarro, Ramón A

2011-01-10

Salmonella enterica serovar Typhimurium is an important pathogen, and exhibits considerable resistance to the lethal effects of solar radiation. To evaluate the involvement of the RpoS transcription factor in the defense mechanisms of this organism, the sunlight response of a wild type strain (ATCC14028) was compared with that of an rpoS mutant, which exhibited increased sensitivity. Kinetics of cell death was complex in both strains, probably due to the presence of a variety of targets for the radiation. When ultraviolet radiation was excluded from the incident sunlight, lethal effects were abolished independently of the allelic state of rpoS. Reduction of oxygen concentration in the irradiation medium provided moderate protection to ATCC14028, but notably improved survival of the mutant. Similar assays were developed with another S. enterica strain (DA1468), which is a derivative of strain LT2 and produces low levels of RpoS. In this strain the loss of viability reveals the dependence on solar ultraviolet and oxygen concentration found for ATCC14028, but radiation resistance was slightly reduced. Increased sensitivity was observed in an rpoS mutant derived from DA1468, indicating that RpoS functions related to photoprotection are conserved in this strain. In addition, notable differences in the shape of the survival curves obtained for mutants derived from ATCC14028 and DA1468 were found, suggesting that genes beyond RpoS control are relevant in the sunlight response of these mutants. Copyright © 2010 Elsevier B.V. All rights reserved.

Polycyclic aromatic hydrocarbons (PAHs) skin permeation rates change with simultaneous exposures to solar ultraviolet radiation (UV-S).

Science.gov (United States)

Hopf, Nancy B; Spring, Philipp; Hirt-Burri, Nathalie; Jimenez, Silvia; Sutter, Benjamin; Vernez, David; Berthet, Aurelie

2018-05-01

Road construction workers are simultaneously exposed to two carcinogens; solar ultraviolet (UV-S) radiation and polycyclic aromatic hydrocarbons (PAHs) in bitumen emissions. The combined exposure may lead to photogenotoxicity and enhanced PAH skin permeation rates. Skin permeation rates (J) for selected PAHs in a mixture (PAH-mix) or in bitumen fume condensate (BFC) with and without UV-S co-exposures were measured with in vitro flow-through diffusion cells mounted with human viable skin and results compared. Possible biomarkers were explored. Js were greater with UV-S for naphthalene, anthracene, and pyrene in BFC (0.08-0.1 ng/cm 2 /h) compared to without (0.02-0.26 ng/cm 2 /h). This was true for anthracene, pyrene, and chrysene in the PAH-mix. Naphthalene and benzo(a)pyrene (BaP) in the PAH-mix had greater Js without (0.97-13.01 ng/cm 2 /h) compared to with UV-S (0.40-6.35 ng/cm 2 /h). Time until permeation (T lags ) in the PAH-mix were generally shorter compared to the BFC, and they ranged from 1 to 13 h. The vehicle matrix could potentially be the reason for this discrepancy as BFC contains additional not identified substances. Qualitative interpretation of p53 suggested a dose-response with UV-S, and somewhat with the co-exposures. MMP1, p65 and cKIT were not exploitable. Although not statistically different, PAHs permeate human viable skin faster with simultaneous exposures to UV. Copyright © 2018 Elsevier B.V. All rights reserved.

Familial melanoma associated with dominant ultraviolet radiation sensitivity

International Nuclear Information System (INIS)

Ramsay, R.G.; Chen, P.; Imray, F.P.; Kidson, C.; Lavin, M.F.; Hockey, A.

1982-01-01

Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some family members exhibited responses similar to those of controls. Cells from four cases of sporadic melanoma showed normal levels of sensitivity. The data are consistent with a dominantly inherited ultraviolet light sensitivity associated with these examples of familial melanoma. Spontaneous and ultraviolet light-induced sister chromatid exchange frequencies were similar to those in control cell lines. No defect in excision repair was detected in any of the above cell lines, but the sensitive group showed postirradiation inhibition of DNA replication intermediate between controls and an excision-deficient xeroderma pigmentosum cell line

Lighting considerations in controlled environments for nonphotosynthetic plant responses to blue and ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Caldwell, M.M.; Flint, S.D. [Utah State Univ., Logan, UT (United States)

1994-12-31

This essay will consider both physical and photobiological aspects of controlled environment lighting in the spectral region beginning in the blue and taken to the normal limit of the solar spectrum in the ultraviolet. The primary emphasis is directed to questions of plant response to sunlight. Measurement and computations used in radiation dosimetry in this part of the spectrum are also briefly treated. Because of interest in the ozone depletion problem, there has been some activity in plant UV-B research and there are several recent reviews available. Some aspects of growth chamber lighting as it relates to UV-B research were covered earlier. Apart from work related to the blue/UV-A receptor, less attention has been given to UV-A responses.

SORCE: Solar Radiation and Climate Experiment

Science.gov (United States)

Cahalan, Robert; Rottman, Gary; Lau, William K. M. (Technical Monitor)

2002-01-01

Contents include the following: Understanding the Sun's influence on the Earth; How the Sun affect Earth's climate; By how much does the Sun's radiation very; Understanding Solar irradiance; History of Solar irradiance observations; The SORCE mission; How do the SORCE instruments measure solar radiation; Total irradiance monitor (TIM); Spectral irradiance monitor (SIM); Solar stellar irradiance comparison experiment (SOLSTICE); XUV photometer system (XPS).

Solar radiation data sources, applications, and network design

Energy Technology Data Exchange (ETDEWEB)

None

1978-04-01

A prerequisite to considering solar energy projects is to determine the requirements for information about solar radiation to apply to possible projects. This report offers techniques to help the reader specify requirements in terms of solar radiation data and information currently available, describes the past and present programs to record and present information to be used for most requirements, presents courses of action to help the user meet his needs for information, lists sources of solar radiation data and presents the problems, costs, benefits and responsibilities of programs to acquire additional solar radiation data. Extensive background information is provided about solar radiation data and its use. Specialized information about recording, collecting, processing, storing and disseminating solar radiation data is given. Several Appendices are included which provide reference material for special situations.

Studying the effect of spectral variations intensity of the incident solar radiation on the Si solar cells performance

Directory of Open Access Journals (Sweden)

Ahmed Elsayed Ghitas

2012-12-01

Full Text Available Solar spectral variation is important in characterization of photovoltaic devices. We present results of an experimental investigation of the effects of the daily spectral variation on the device performance of multicrystalline silicon photovoltaic module. The investigation concentrate on the analysis of outdoor solar spectral measurements carried out at 1 min intervals on clear sky days. Short circuit current and open circuit voltage have been measured to describe the module electrical performance. We have shown that the shift in the solar spectrum towards infrared has a negative impact on the device performance of the module. The spectral bands in the visible region contribute more to the short circuit current than the bands in the infrared region while the ultraviolet region contributes least. The quantitative effect of the spectral variation on the performance of the photovoltaic module is reflected on their respective device performance parameters. The decrease in the visible and the increase in infrared of the radiation spectra account for the decreased current collection and hence power of the module.

New high-resolution rocket-ultraviolet filtergrams of the solar disc

Science.gov (United States)

Foing, B.; Bonnet, R.-M.; Bruner, M.

1986-01-01

A rocket-borne solar ultraviolet telescope named Transition Region Camera was launched successfully for the third on July 13, 1982. High quality calibrated photographic images of the sun were obtained at Lyman alpha and in the continuum at 160 nm and 220 nm. The angular resolution achieved is better than one arcsec. A flare, active regions, sunspots, the 8 Mm mesostructure, the chromospheric network, bright UV grains and coronal loops were observed during the flight. The results are presented and the evolution with height in the solar atmosphere of the various structures observed is followed from one wavelength to the other, showing distinct differences. The value of the field's intensity of magnetic flux tubes is deduced from the observations.

Solar radiation on Mars: Update 1991

Science.gov (United States)

Appelbaum, Joseph; Landis, Geoffrey A.

1991-01-01

Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. A procedure and solar radiation related data are presented from which the daily variation of the global, direct beam and diffuse insolation on Mars are calculated. Given the optical depth of the Mars atmosphere, the global radiation is calculated from the normalized net flux function based on multiple wavelength and multiple scattering of the solar radiation. The direct beam was derived from the optical depth using Beer's law, and the diffuse component was obtained from the difference of the global and the direct beam radiation. The optical depths of the Mars atmosphere were derived from images taken of the Sun with a special diode on the cameras used on the two Viking Landers.

Tm2+ luminescent materials for solar radiation conversion devices

NARCIS (Netherlands)

Van der Kolk, E.

2015-01-01

A solar radiation conversion device is described that comprises a luminescent Tm 2+ inorganic material for converting solar radiation of at least part of the UV and/or visible and/or infra red solar spectrum into infrared solar radiation, preferably said infrared solar radiation having a wavelength

Solar ultraviolet radiation induced variations in the stratosphere and mesosphere

Science.gov (United States)

Hood, L. L.

1987-01-01

The detectability and interpretation of short-term solar UV induced responses of middle atmospheric ozone, temperature, and dynamics are reviewed. The detectability of solar UV induced perturbations in the middle atmosphere is studied in terms of seasonal and endogenic dynamical variations. The interpretation of low-latitude ozone and possible temperature responses on the solar rotation time scale is examined. The use of these data to constrain or test photochemical model predictions is discussed.

an assessment of ultraviolet radiation components of light emitted ...

African Journals Online (AJOL)

Dr

therefore high for exposure limits of 8 hours for UV-B and UV-C and the 16 minutes for UV-A. The investigation ... has become particularly interesting as the ozone layer ... THEORY. Ultraviolet (UV) light is an electromagnetic radiation with a ...

Health effects of exposure to ultraviolet and infrared radiation

International Nuclear Information System (INIS)

Thuerauf, J.R.

1979-01-01

A working group on the Health Effects of Exposure to Ultraviolet and Infrared Radiation met in Sofia (Bulgaria) from February 21-25, 1978. The conference was organized by the European Regional Bureau of the World Health Organization, WHO, in cooperation with the Bulgarian government. The main task for the participants was the revision and discussion of two guidelines. A Manual on Nonionizing Radiation Protection will be made available in 1979 to governmental and official organs to support them in establishing standards for the control of radiation. (orig.) [de

Solar radiation on domed roofs

Energy Technology Data Exchange (ETDEWEB)

Faghih, Ahmadreza K.; Bahadori, Mehdi N. [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran)

2009-11-15

Solar radiation received and absorbed by four domed roofs was estimated and compared with that of a flat roof. The domed roofs all had the same base areas, and equal to that of the flat roof. One of the roofs considered was the dome of the St. Peter's Church in Rome. Compared with the other roofs considered, this dome had a higher aspect ratio. It was found that all domed roofs received more solar radiation than the flat roof. Considering glazed tiles to cover a selected dome in Iran and the dome of the St. Peter's Church, it was found that the solar radiation absorbed by these roofs is reduced appreciably. In the case of the dome of St. Peter's Church, the amount of radiation absorbed was roughly equal to that absorbed by the comparable flat roof in the warm months. In the case of the glazed reference dome located in Yazd, Iran (a city with very high solar radiation), the radiation absorbed was less than that of flat roof at all times. In addition to aesthetics, this may be a reason for employing glazed tiles to cover the domes of all mosques, shrines, and other large buildings in Iran. (author)

Preliminary observations and results obtained with the ultraviolet spectrometer and polarimeter. [for Solar Maximum Mission

Science.gov (United States)

Tandberg-Hassen, E.; Cheng, C. C.; Athay, R. G.; Beckers, J. M.; Brandt, J. C.; Chapman, R. D.; Bruner, E. C.; Henze, W.; Hyder, C. L.; Gurman, J. B.

1981-01-01

New observation with the Ultraviolet Spectrometer and Polarimeter (UVSP) of a number of manifestations of solar activity obtained during the first three months of Solar Maximum Mission operations are presented. Attention is given to polarimetry in sunspots, oscillations above sunspots, density diagnostics of transition-zone plasmas in active regions, and the eruptive prominence - coronal transient link.

Bystander effects in UV-induced genomic instability: Antioxidants inhibit delayed mutagenesis induced by ultraviolet A and B radiation

Directory of Open Access Journals (Sweden)

Dahle Jostein

2005-01-01

Full Text Available Abstract Background Genomic instability is characteristic of many types of human cancer. Recently, we reported that ultraviolet radiation induced elevated mutation rates and chromosomal instability for many cell generations after ultraviolet irradiation. The increased mutation rates of unstable cells may allow them to accumulate aberrations that subsequently lead to cancer. Ultraviolet A radiation, which primarily acts by oxidative stress, and ultraviolet B radiation, which initially acts by absorption in DNA and direct damage to DNA, both produced genomically unstable cell clones. In this study, we have determined the effect of antioxidants on induction of delayed mutations by ultraviolet radiation. Delayed mutations are indicative of genomic instability. Methods Delayed mutations in the hypoxanthine phosphoribosyl transferase (hprt gene were detected by incubating the cells in medium selectively killing hprt mutants for 8 days after irradiation, followed by a 5 day period in normal medium before determining mutation frequencies. Results The UVB-induced delayed hprt mutations were strongly inhibited by the antioxidants catalase, reduced glutathione and superoxide dismutase, while only reduced glutathione had a significant effect on UVA-induced delayed mutations. Treatment with antioxidants had only minor effects on early mutation frequenies, except that reduced glutathione decreased the UVB-induced early mutation frequency by 24 %. Incubation with reduced glutathione was shown to significantly increase the intracellular amount of reduced glutathione. Conclusion The strong effects of these antioxidants indicate that genomic instability, which is induced by the fundamentally different ultraviolet A and ultraviolet B radiation, is mediated by reactive oxygen species, including hydrogen peroxide and downstream products. However, cells take up neither catalase nor SOD, while incubation with glutathione resulted in increased intracellular levels of

Workshop Report on Managing Solar Radiation

Science.gov (United States)

Lane, Lee (Compiler); Caldeira, Ken (Compiler); Chatfield, Robert (Compiler); Langhoff, Stephanie (Compiler)

2007-01-01

The basic concept of managing Earth's radiation budget is to reduce the amount of incoming solar radiation absorbed by the Earth so as to counterbalance the heating of the Earth that would otherwise result from the accumulation of greenhouse gases. The workshop did not seek to decide whether or under what circumstances solar radiation management should be deployed or which strategies or technologies might be best, if it were deployed. Rather, the workshop focused on defining what kinds of information might be most valuable in allowing policy makers more knowledgeably to address the various options for solar radiation management.

Measurement of solar energy radiation in Abu Dhabi, UAE

Energy Technology Data Exchange (ETDEWEB)

Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi, P.O. Box 2533 (United Arab Emirates)

2009-04-15

This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 N, 54.45 E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m{sup 2}, respectively. The highest one-minute average daily solar radiation was 1041 W/m{sup 2}. Yearly average daily energy input was 18.48 MJ/m{sup 2}/day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture. (author)

Measurement of solar energy radiation in Abu Dhabi, UAE

International Nuclear Information System (INIS)

Islam, M.D.; Kubo, I.; Ohadi, M.; Alili, A.A.

2009-01-01

This paper presents data on measurement of actual solar radiation in Abu Dhabi (24.43 deg. N, 54.45 deg. E). Global solar radiation and surface temperatures were measured and analyzed for one complete year. High resolution, real-time solar radiation and other meteorological data were collected and processed. Daily and monthly average solar radiation values were calculated from the one-minute average recorded values. The highest daily and monthly mean solar radiation values were 369 and 290 W/m 2 , respectively. The highest one-minute average daily solar radiation was 1041 W/m 2 . Yearly average daily energy input was 18.48 MJ/m 2 /day. Besides the global solar radiation, the daily and monthly average clearness indexes along with temperature variations are discussed. When possible, global solar energy radiation and some meteorological data are compared with corresponding data in other Arab state capitals. The data collected indicate that Abu Dhabi has a strong potential for solar energy capture

Cataract frequency and subtypes involved in workers assessed for their solar radiation exposure: a systematic review.

Science.gov (United States)

Modenese, Alberto; Gobba, Fabriziomaria

2018-04-16

Cataract is currently the primary cause of blindness worldwide, and one of its main risk factors is solar ultraviolet radiation exposure. According to the localization of lens opacities, three main subtypes of cataract are recognized: nuclear, cortical and posterior subcapsular cataract. One of the main determinants of individual long-term solar radiation exposure is outdoor work. We systematically reviewed scientific literature from the last 20 years to update the recent development of research on the risk of cataract in outdoor workers and on the specific subtypes involved, also investigating the methods applied to evaluate the occupational risk. A total of 15 studies were included in the review, of which 12 showed a positive association. The studies confirm the relationship of long-term occupational solar radiation exposure with cortical cataract and give new support for nuclear cataract, although no substantial new data were available to support a relation with the posterior subcapsular subtype. In most of the studies, the exposure assessment was not adequate to support a representative evaluation of the ocular risk; however, outdoor work is clearly a relevant risk factor for cataract. Further research providing a better evaluation of the relation between solar radiation exposure levels and lens damage in workers is needed and aimed to establish adequate occupational exposure limits and better preventive measures, studying also their effectiveness. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Effects of near ultraviolet and green radiations on plant growth

Energy Technology Data Exchange (ETDEWEB)

Klein, R.M.; Edsall, P.C.; Gentile, A.C.

1965-01-01

Selective removal of near ultraviolet and green wavelengths from white light permitted enhanced growth of marigold, tomato, corn, and Impatiens plants, Chlamydomonas cells and the mycelium of Sordaria. Additions of near ultraviolet and green radiations caused repressions in the growth of marigold and Sordaria. These wavelengths do not alter the oxidative mechanisms of mitochondria, intact algal cells or marigold leaf tissues. The capacity for chlorophyll and carotenoid synthesis by Euglena cells was unaffected by these wavelengths. 23 references, 2 figures, 4 tables.

Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

Science.gov (United States)

Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

2002-01-01

Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

[Solar radiation exposure in agriculture: an underestimated risk].

Science.gov (United States)

Gobba, F

2012-01-01

Solar Radiation (SR) is a major occupational risk in agriculture, mainly related to its ultraviolet (UV) component. Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma and squamous cell carcinoma of the skin, and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in agriculture. The role of the Occupational Physician in prevention is fundamental.

Effect of near-ultraviolet radiation on the cell surface of the protozoan Tritichomonas foetus

International Nuclear Information System (INIS)

Filho, F.C.S.; Elias, C.A.; Souza, W. de

1982-01-01

It is concluded that the authors' data showing that near-ultraviolet radiation decreases the cellular electrophoretic mobility of Tritrichomonas foetus indicate that ultraviolet radiation may have an important effect on basic properties of the plasma membrane such as (a) its surface charge, (b) the mobility of membrane-associated components, as revealed by the concanavalin A-induced agglutination, and (c) changes in its permeability to cytoplasmic components. These data also indicate that protozoa may be a useful model for studies related with the effect of radiation on eukaryotic cells. (author)

Parameterization Of Solar Radiation Using Neural Network

International Nuclear Information System (INIS)

Jiya, J. D.; Alfa, B.

2002-01-01

This paper presents a neural network technique for parameterization of global solar radiation. The available data from twenty-one stations is used for training the neural network and the data from other ten stations is used to validate the neural model. The neural network utilizes latitude, longitude, altitude, sunshine duration and period number to parameterize solar radiation values. The testing data was not used in the training to demonstrate the performance of the neural network in unknown stations to parameterize solar radiation. The results indicate a good agreement between the parameterized solar radiation values and actual measured values

AUMENTO DEL ÍNDICE SOLAR ULTRAVIOLETA CON LA ALTURA SOLAR ULTRAVIOLET INDEX INCREASE WITH ALTITUDE

Directory of Open Access Journals (Sweden)

Miguel Rivas A

2008-09-01

Full Text Available En este trabajo se presentan los resultados obtenidos al realizar comparaciones entre mediciones experimentales de Índice solar ultravioleta (IUV obtenido a partir de datos experimentales y también de resultados teóricos proveniente del cálculo del IUV mediante el modelo TUV (modelo ultravioleta troposféricol. En especial se destacan los aumentos de la irradianza solar ultravioleta B (UVB 280-320 nm que se reciben a nivel del suelo debido a los aumentos de la altitud del lugar sobre el nivel del mar (efecto altitudinal. Los cálculos mediante el modelo TUV se realizaron en un período comprendido entre los años 1996-2003, introduciendo los parámetros de los lugares geográficos en que se hicieron las mediciones experimentales. Dado que una de las variables importantes de la que depende el IUV es la altitud sobre el nivel del mar y considerando que la zona norte de Chile es un lugar con características especiales para realizar este tipo de estudios, es que se han realizado experimentos para medir la irradianza solar UVB entre 0-3.200 m de altura, y a partir de estos datos se ha obtenido el IUV. La importancia de estos resultados radica en el hecho que a partir de ellos se pueden cuantificar el incremento de la irradianza UVB por cada 1.000 m de altitud sobre el nivel del mar. Un número creciente de personas se desplazan continuamente entre el nivel del mar y altitudes cercanas a los 5.000 m, debido a trabajos relacionados con: minería, turismo, transporte. En todos estos casos estas personas reciben importantes incrementos de irradianza solar UV, que pueden afectar gravemente su salud si no se informan de los riesgos para que puedan tomar precauciones.In this work we present results from ultraviolet solar index (IUV comparisons between values obtained from experimental measurements, with theoretical results obtained from tropospherical ultraviolet model (TUV. It is important to emphasise the observed increase in solar ultraviolet B (UVB

The Role of Macrophage Migration Inhibitory Factor (MIF) in Ultraviolet Radiation-Induced Carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Tadamichi [Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, 930-0194, Toyama (Japan)

2010-08-09

Ultraviolet (UV) radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn) of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α. and macrophage migration inhibitory factor (MIF). MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer.

The Role of Macrophage Migration Inhibitory Factor (MIF) in Ultraviolet Radiation-Induced Carcinogenesis

International Nuclear Information System (INIS)

Shimizu, Tadamichi

2010-01-01

Ultraviolet (UV) radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn) of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α. and macrophage migration inhibitory factor (MIF). MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer

The Role of Macrophage Migration Inhibitory Factor (MIF in Ultraviolet Radiation-Induced Carcinogenesis

Directory of Open Access Journals (Sweden)

Tadamichi Shimizu

2010-08-01

Full Text Available Ultraviolet (UV radiation is the most common cause of physical injury to the skin due to environmental damage, and UV exposure substantially increases the risk of actinic damage to the skin. The inflammatory changes induced by acute UV exposure include erythema (sunburn of the skin, while chronic exposure to solar UV radiation causes photo-aging, immunosuppression, and ultimately, carcinogenesis of the skin. After skin damage by UV radiation, the cells are known to secrete many cytokines, including interleukin (IL-1, IL-6, tumor necrosis factor (TNF-α. and macrophage migration inhibitory factor (MIF. MIF was originally identified as a lymphokine that concentrates macrophages at inflammatory loci, and is known to be a potent activator of macrophages in vivo. MIF is considered to play an important role in cell-mediated immunity. Since the molecular cloning of MIF cDNA, MIF has been re-evaluated as a proinflammatory cytokine and pituitary-derived hormone that potentiates endotoxemia. MIF is ubiquitously expressed in various tissues, including the skin. Recent studies have suggested a potentially broader role for MIF in growth regulation because of its ability to antagonize p53-mediated gene activation and apoptosis. This article reviews the latest findings on the roles of MIF with regard to UV-induced skin cancer.

Spectroscopic observation of the middle ultraviolet earth albedo by S-520-4 rocket and mesospheric ozone density profile

International Nuclear Information System (INIS)

Suzuki, Katsuhisa; Ogawa, Toshihiro.

1982-01-01

The ozone Hartey absorption band in the middle ultraviolet range is commonly adopted for the ozone measurement by rocket and satellite observations. In Japan, since 1965 the ozone absorption in the solar ultraviolet radiation has been observed by rocket-borne uv photometers. On the other hand the spectroscopic measurements of the scattered solar ultraviolet radiation from the terrestrial atmosphere will be performed by the EXOS-C satellite which will be launched in 1984. We tested the spectrometer for this satellite experiment by S-520-4 rocket launched on 5 September 1981. This instrument observed the scattered radiation of 2500 A -- 3300 A and the visible earth albedo of 4030 A. The spectrometer is consisted of a concave grating and has about 10 A wavelength resolution. A photomultiplier having a Cs-Te photocathode is used as a uv detector. The visible albedo is measured by a photometer consisting of an interference filter and a phototube. We estimated the atmospheric ozone profile, comparing the uv spectrum obtained by this experiment with the model calculations. The estimated ozone density profile higher than 30 km altitude has good agreement with the profile obtained by the previous uv photometer experiments at Uchinoura. There are differences between the observed spectrum and the calculated one in = 3100 A. We can explain them by the effect of Mie scattering and the uv stray light. In the present experiment we could successfully test the functions of the instrument in the space. rocket, spectrometer, solar ultraviolet radiation, earth albedo, ozone (author)

Solar UV exposure among outdoor workers in Denmark measured with personal UV-B dosimeters

DEFF Research Database (Denmark)

Grandahl, Kasper; Mortensen, Ole Steen; Sherman, David Zim

2017-01-01

radiation exposure are needed to help resolve this problem. This can be done using personal ultraviolet radiation dosimeters. Methods: We consider technical and practical feasibility of measuring individual solar ultraviolet exposure at work and leisure in professions with different á priori temporal high......-level outdoor worktime, using aluminium gallium nitride (AlGaN) photodiode detector based personal UV-B dosimeters. Essential technical specifications including the spectral and angular responsivity of the dosimeters are described and pre-campaign dosimeter calibration applicability is verified. The scale...... with our specialist knowledge as occupational physicians. Conclusions: Large-scale use of personal UV-B dosimeters for measurement of solar ultraviolet radiation exposure at work and leisure in Denmark is indeed feasible from a technical and practical viewpoint. Samples of exposure data shown support...

MgII Linear Polarization Measurements Using the MSFC Solar Ultraviolet Magnetograph

Science.gov (United States)

West, Edward; Cirtain, Jonathan; Kobayahsi, Ken; Davis, John; Gary, Allen; Adams, Mitzi

2011-01-01

This paper will describe the Marshall Space Flight Center's Solar Ultraviolet Magnetograph (SUMI) sounding rocket program, with emphasis on the polarization characteristics of the VUV optics and their spectral, spatial and polarization resolution. SUMI's first flight (7/30/2010) met all of its mission success criteria and this paper will describe the data that was acquired with emphasis on the MgII linear polarization measurements.

Effects of Ultraviolet Radiation on Human Health (invited paper)

International Nuclear Information System (INIS)

MacKie, R.M.

2000-01-01

The detrimental and beneficial effects of exposure to ultraviolet radiation in the UVB and UVA ranges are discussed. The main benefit of UV radiation is promoting the synthesis of vitamin D from precursors in the skin. Detrimental effects include acute sun damage in the form of sunburn and chronic sun damage leading to photoageing and possibly to cutaneous malignancies. Other detrimental effects of UV exposure include photosensitivity reactions to ingested drugs and rare examples of genetically determined photosensitivies. (author)

Effects of Ultraviolet Radiation on Human Health (invited paper)

Energy Technology Data Exchange (ETDEWEB)

MacKie, R.M

2000-07-01

The detrimental and beneficial effects of exposure to ultraviolet radiation in the UVB and UVA ranges are discussed. The main benefit of UV radiation is promoting the synthesis of vitamin D from precursors in the skin. Detrimental effects include acute sun damage in the form of sunburn and chronic sun damage leading to photoageing and possibly to cutaneous malignancies. Other detrimental effects of UV exposure include photosensitivity reactions to ingested drugs and rare examples of genetically determined photosensitivies. (author)

OBSERVATIONS OF FIVE-MINUTE SOLAR OSCILLATIONS IN THE CORONA USING THE EXTREME ULTRAVIOLET SPECTROPHOTOMETER (ESP) ON BOARD THE SOLAR DYNAMICS OBSERVATORY EXTREME ULTRAVIOLET VARIABILITY EXPERIMENT (SDO/EVE)

International Nuclear Information System (INIS)

Didkovsky, L.; Judge, D.; Wieman, S.; Kosovichev, A. G.; Woods, T.

2011-01-01

We report on the detection of oscillations in the corona in the frequency range corresponding to five-minute acoustic modes of the Sun. The oscillations have been observed using soft X-ray measurements from the Extreme Ultraviolet Spectrophotometer (ESP) of the Extreme Ultraviolet Variability Experiment on board the Solar Dynamics Observatory. The ESP zeroth-order channel observes the Sun as a star without spatial resolution in the wavelength range of 0.1-7.0 nm (the energy range is 0.18-12.4 keV). The amplitude spectrum of the oscillations calculated from six-day time series shows a significant increase in the frequency range of 2-4 mHz. We interpret this increase as a response of the corona to solar acoustic (p) modes and attempt to identify p-mode frequencies among the strongest peaks. Due to strong variability of the amplitudes and frequencies of the five-minute oscillations in the corona, we study how the spectrum from two adjacent six-day time series combined together affects the number of peaks associated with the p-mode frequencies and their amplitudes. This study shows that five-minute oscillations of the Sun can be observed in the corona in variations of the soft X-ray emission. Further investigations of these oscillations may improve our understanding of the interaction of the oscillation modes with the solar atmosphere, and the interior-corona coupling, in general.

Red tattoos, ultraviolet radiation and skin cancer in mice

DEFF Research Database (Denmark)

Lerche, Catharina M.; Heerfordt, Ida M.; Serup, Jørgen

2017-01-01

Ultraviolet radiation (UVR) induces skin cancer. The combination of UVR and red tattoos may be associated with increased risk of skin cancer due to potential carcinogens in tattoo inks. This combination has not been studied previously. Immunocompetent C3.Cg/TifBomTac hairless mice (n=99) were...

Solar cell radiation handbook. Addendum 1: 1982-1988

International Nuclear Information System (INIS)

Anspaugh, B.E.

1989-02-01

The Solar Cell Radiation Handbook (JPL Publication 82-69) is updated. In order to maintain currency of solar cell radiation data, recent solar cell designs have been acquired, irradiated with 1 MeV electrons, and measured. The results of these radiation experiments are reported

A Solar Radiation Parameterization for Atmospheric Studies. Volume 15

Science.gov (United States)

Chou, Ming-Dah; Suarez, Max J. (Editor)

1999-01-01

The solar radiation parameterization (CLIRAD-SW) developed at the Goddard Climate and Radiation Branch for application to atmospheric models are described. It includes the absorption by water vapor, O3, O2, CO2, clouds, and aerosols and the scattering by clouds, aerosols, and gases. Depending upon the nature of absorption, different approaches are applied to different absorbers. In the ultraviolet and visible regions, the spectrum is divided into 8 bands, and single O3 absorption coefficient and Rayleigh scattering coefficient are used for each band. In the infrared, the spectrum is divided into 3 bands, and the k-distribution method is applied for water vapor absorption. The flux reduction due to O2 is derived from a simple function, while the flux reduction due to CO2 is derived from precomputed tables. Cloud single-scattering properties are parameterized, separately for liquid drops and ice, as functions of water amount and effective particle size. A maximum-random approximation is adopted for the overlapping of clouds at different heights. Fluxes are computed using the Delta-Eddington approximation.

Estimating surface solar radiation from upper-air humidity

Energy Technology Data Exchange (ETDEWEB)

Kun Yang [Telecommunications Advancement Organization of Japan, Tokyo (Japan); Koike, Toshio [University of Tokyo (Japan). Dept. of Civil Engineering

2002-07-01

A numerical model is developed to estimate global solar irradiance from upper-air humidity. In this model, solar radiation under clear skies is calculated through a simple model with radiation-damping processes under consideration. A sky clearness indicator is parameterized from relative humidity profiles within three atmospheric sublayers, and the indicator is used to connect global solar radiation under clear skies and that under cloudy skies. Model inter-comparisons at 18 sites in Japan suggest (1) global solar radiation strongly depends on the sky clearness indicator, (2) the new model generally gives better estimation to hourly-mean solar irradiance than the other three methods used in numerical weather predictions, and (3) the new model may be applied to estimate long-term solar radiation. In addition, a study at one site in the Tibetan Plateau shows vigorous convective activities in the region may cause some uncertainties to radiation estimations due to the small-scale and short life of convective systems. (author)

Avoidable cancers in the Nordic countries. Radiation

DEFF Research Database (Denmark)

Winther, J F; Ulbak, Kaare; Dreyer, L

1997-01-01

Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our...... malignant melanomas arising in the Nordic populations around the year 2000 will be due to exposure to natural ultraviolet radiation, equivalent to an annual number of about 4700 cases, with 2100 in men and 2600 in women, or some 4% of all cancers notified. Exposure to ionizing radiation in the Nordic...... and building materials, the man-made sources are dominated by the diagnostic and therapeutic use of ionizing radiation. On the basis of measured levels of radon in Nordic dwellings and associated risk estimates for lung cancer derived from well-conducted epidemiological studies, we estimated that about 180...

Additive effects of ultraviolet radiation

International Nuclear Information System (INIS)

Cullen, A.P.

1980-01-01

A xenon-mercury high pressure lamp and a double monochromator were used to produce ultraviolet (uv) radiation at 295 nm. Pigmented rabbit eyes were irradiated and evaluated by slitlamp biomicroscopy. Corneal threshold (Hc) was 0.05 J.cm-2 and lens threshold (hL) was 0.75 J.cm-2. Other eyes were irradiated with 2 Hc and evaluated from 4 to 24 h at 4 h intervals. Corneal damage was only greater than that expected from a single Hc exposure if the separation between the two Hc exposures did not exceed 8 h. The most repeatable and reliable corneal response to these levels of uv was the development of corneal epithelial granules

Interventions to prevent skin cancer by reducing exposure to ultraviolet radiation: a systematic review.

Science.gov (United States)

Saraiya, Mona; Glanz, Karen; Briss, Peter A; Nichols, Phyllis; White, Cornelia; Das, Debjani; Smith, S Jay; Tannor, Bernice; Hutchinson, Angela B; Wilson, Katherine M; Gandhi, Nisha; Lee, Nancy C; Rimer, Barbara; Coates, Ralph C; Kerner, Jon F; Hiatt, Robert A; Buffler, Patricia; Rochester, Phyllis

2004-12-01

The relationship between skin cancer and ultraviolet radiation is well established. Behaviors such as seeking shade, avoiding sun exposure during peak hours of radiation, wearing protective clothing, or some combination of these behaviors can provide protection. Sunscreen use alone is not considered an adequate protection against ultraviolet radiation. This report presents the results of systematic reviews of effectiveness, applicability, other harms or benefits, economic evaluations, and barriers to use of selected interventions to prevent skin cancer by reducing exposure to ultraviolet radiation. The Task Force on Community Preventive Services found that education and policy approaches to increasing sun-protective behaviors were effective when implemented in primary schools and in recreational or tourism settings, but found insufficient evidence to determine effectiveness when implemented in other settings, such as child care centers, secondary schools and colleges, and occupational settings. They also found insufficient evidence to determine the effectiveness of interventions oriented to healthcare settings and providers, media campaigns alone, interventions oriented to parents or caregivers of children, and community-wide multicomponent interventions. The report also provides suggestions for areas for future research.

Correlation of total, diffuse, and direct solar radiation

Science.gov (United States)

Buyco, E. H.; Namkoong, D.

1977-01-01

Present requirements for realistic solar energy system evaluations necessitate a comprehensive body of solar-radition data. The data should include both diffuse and direct solar radiation as well as their total on an hourly (or shorter) basis. In general, however, only the total solar radiation values were recorded. This report presents a correlation that relates the diffuse component of an hourly total solar radiation value to the total radiation ratio of the maximum value attainable. The data used were taken at the Blue Hill Observatory in Milton, Massachusetts, for the period 1952. The relation - in the form of the data plots - can be used in situations in which only the hourly total radiation data are available but the diffuse component is desired.

Protection of humans from ultraviolet radiation through the use of textiles: a review

International Nuclear Information System (INIS)

Capjack, L.; Kerr, N.; Davis, S.; Fedosejevs, R.; Hatch, K.L.; Markee, N.L.

1994-01-01

One of the growing concerns of the present decade is the health risk associated with exposure to ultraviolet radiation (UVR) and its link with problems such as carcinogenesis, cataracts, sunburn, and photoaging. For protection from UVR, medical experts recommend avoiding exposure, using sunscreens, donning hats, and covering up with clothing. Research on the solar-protective value of clothing, however, still leaves many questions unanswered. This review of literature identifies the need for appropriate protection from the sun, especially for children, and the benefits of clothing as protection. The methods and difficulties associated with assessing the UVR protection and the definition of the sun protection factor (SPF) of clothing are outlined and discussed. Studies using in vivo, radiometric, and spectrophotometric methodologies to assess the UVR transmission throughfabrics are examined. Fabric variables, identified in the literature, that have been found to affect UVR transmission values are discussed

High Radiation Resistance IMM Solar Cell

Science.gov (United States)

Pan, Noren

2015-01-01

Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

Exposure to solar ultraviolet radiation: a hot topic?

International Nuclear Information System (INIS)

Vernez, David; Backes, Claudine; Milon, Antoine

2016-01-01

The Sun can be harmful to human health, about a certain threshold. More than occasional exposures, it is chronic exposures that are responsible for the majority of the UV-related skin cancers that affect numerous outdoor workers. Solar exposure should not merely be a public health issue, it should also be raised in the working world. (authors)

A pilot solar water disinfecting system: performance analysis and testing

Energy Technology Data Exchange (ETDEWEB)

Saitoh, T.S.; El-Ghetany, H.H. [Tohoku University, Sendai (Japan). Dept. of Aeronautics and Space Engineering

2002-07-01

In most countries, contaminated water is the major cause of most water-borne diseases. Disinfection of water may be accomplished by a number of different physical-chemical treatments including direct application of thermal energy, chemical and filtration techniques. Solar energy also can be used effectively in this field because inactivation of microorganisms is done either by heating water to a disinfecting temperature or by exposing it to ultraviolet solar radiation. A pilot solar system for disinfecting contaminated water is designed, constructed and tested. Investigations are carried out to evaluate the performance of a wooden hot box solar facility as a solar disinfectant. Experimental data show that solar energy is viable for the disinfection process. A solar radiation model is presented and compared with the experimental data. A mathematical model of the solar disinfectant is also presented. The governing equations are solved numerically via the fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed, solar radiation, etc.) on the performance of the solar disinfectant are examined. Results showed that the system is affected by ambient temperature, wind speed, ultraviolet solar radiation intensity, the turbidity of the water, the quantity of water exposed, the contact area between the transparent water container in the solar disinfectant and the absorber plate as well as the geometrical parameters of the system. It is pointed out that for partially cloudy conditions with a low ambient temperature and high wind speeds, the thermal efficiency of the solar disinfectant is at a minimum. The use of solar energy for the disinfection process will increase the productivity of the system while completely eliminating the coliform group bacteria at the same time. (author)

Solar radiation and out-of-hospital cardiac arrest in Japan.

Science.gov (United States)

Onozuka, Daisuke; Hagihara, Akihito

2017-11-01

Although several studies have estimated the effects of temperature on mortality and morbidity, little is known regarding the burden of out-of-hospital cardiac arrest (OHCA) attributable to solar radiation. We obtained data for all cases of OHCA and meteorological data reported between 2011 and 2014 in 3 Japanese prefectures: Hokkaido, Ibaraki, and Fukuoka. We first examined the relationship between daily solar radiation and OHCA risk for each prefecture using time-varying distributed lag non-linear models and then pooled the results in a multivariate random-effects meta-analysis. The attributable fractions of OHCA were calculated for low and high solar radiation, defined as solar radiation below and above the minimum morbidity solar radiation, respectively. The minimum morbidity solar radiation was defined as the specific solar radiation associated with the lowest morbidity risk. A total of 49,892 cases of OHCA occurred during the study period. The minimum morbidity solar radiation for each prefecture was the 100th percentile (72.5 MJ/m 2 ) in Hokkaido, the 83rd percentile (59.7 MJ/m 2 ) in Ibaraki, and the 70th percentile (53.8 MJ/m 2 ) in Fukuoka. Overall, 20.00% (95% empirical confidence interval [eCI]: 10.97-27.04) of the OHCA cases were attributable to daily solar radiation. The attributable fraction for low solar radiation was 19.50% (95% eCI: 10.00-26.92), whereas that for high solar radiation was 0.50% (95% eCI: -0.07-1.01). Low solar radiation was associated with a substantial attributable risk for OHCA. Our findings suggest that public health efforts to reduce OHCA burden should consider the solar radiation level. Large prospective studies with longitudinal collection of individual data is required to more conclusively assess the impact of solar radiation on OHCA. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultraviolet light exposure and skin cancer in the city of Arica, Chile.

Science.gov (United States)

Rivas, Miguel; Araya, María C; Durán, Viviava; Rojas, Elisa; Cortes, Juan; Calaf, Gloria M

2009-01-01

An increase in the amount of solar ultraviolet light that reaches the Earth is considered to be responsible for the worldwide increase in skin cancer. Solar ultraviolet B (UVB) light (290-320 nm) has multiple effects that can be harmful to human beings. The city of Arica in Chile receives high UV levels. This can explain the high prevalence of skin cancer in the Arica population. In the present study, pathological reports of skin cancer were collected from an Arica hospital and retrospectively examined to investigate the possible effects of UV radiation. Among the malignant skin tumor types, basocellular and spinocellular carcinomas were more common in men (44.4 and 16.6%, respectively) than in women (24.9 and 10.7%, respectively). Basocellular carcinoma was observed in individuals 40-79 years of age. The incidence of skin cancer significantly increased (Plight to which individuals are exposed throughout the year, and the cumulative effect of this type of radiation on the skin.

Solar Indices - Solar Ultraviolet

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

Melanocortin 1 receptor genotype: an important determinant of the damage response of melanocytes to ultraviolet radiation

Science.gov (United States)

Kadekaro, Ana Luisa; Leachman, Sancy; Kavanagh, Renny J.; Swope, Viki; Cassidy, Pamela; Supp, Dorothy; Sartor, Maureen; Schwemberger, Sandy; Babcock, George; Wakamatsu, Kazumasa; Ito, Shosuke; Koshoffer, Amy; Boissy, Raymond E.; Manga, Prashiela; Sturm, Richard A.; Abdel-Malek, Zalfa A.

2010-01-01

The melanocortin 1 receptor gene is a main determinant of human pigmentation, and a melanoma susceptibility gene, because its variants that are strongly associated with red hair color increase melanoma risk. To test experimentally the association between melanocortin 1 receptor genotype and melanoma susceptibility, we compared the responses of primary human melanocyte cultures naturally expressing different melanocortin 1 receptor variants to α-melanocortin and ultraviolet radiation. We found that expression of 2 red hair variants abolished the response to α-melanocortin and its photoprotective effects, evidenced by lack of functional coupling of the receptor, and absence of reduction in ultraviolet radiation-induced hydrogen peroxide generation or enhancement of repair of DNA photoproducts, respectively. These variants had different heterozygous effects on receptor function. Microarray data confirmed the observed differences in responses of melanocytes with functional vs. nonfunctional receptor to α-melanocortin and ultraviolet radiation, and identified DNA repair and antioxidant genes that are modulated by α-melanocortin. Our findings highlight the molecular mechanisms by which the melanocortin 1 receptor genotype controls genomic stability of and the mutagenic effect of ultraviolet radiation on human melanocytes.—Kadekaro, A. L., Leachman, S., Kavanagh, R. J., Swope, V., Cassidy, P., Supp, D., Sartor, M., Schwemberger, S., Babcock, G., Wakamatsu, K., Ito, S., Koshoffer, A., Boissy, R. E., Manga, P., Sturm, R. A., Abdel-Malek, Z. A. Melanocortin 1 receptor genotype: an important determinant of the damage response of melanocytes to ultraviolet radiation. PMID:20519635

Effects of antibiotics and ultraviolet radiation on the halophilic blue-green alga

International Nuclear Information System (INIS)

Yopp, J.H.; Albright, G.; Miller, D.M.; Southern Illinois Univ., Carbondale

1979-01-01

The effects of a variety of antibiotics, ultraviolet radiation and N-methyl-N-nitro-N-nitro-N-nitrosoguanidine (NTG) on the survival and mutability of the halophilic blue-green alga, Aphanothece halophytica, were determined. The halophile was found extremely sensitive to penicillin G and bacitracin; moderately sensitive to novobiocin, amino acid analogs, chloramphenicol and streptomycin; and tolerant to actidione and hydroxyurea. Ultraviolet and NTG killing curves and photoreactivation capabilities were seimilar to those reported for other members of the Chroococcales. Three stable morphological mutants were obtained by ultraviolet and NTG treatment, the latter being much more efficient in the production of mutants. (orig.)

Using an Ongoing Study of Terrestrial Plant Response to Ultraviolet Radiation in Project ALERT

Science.gov (United States)

Condon, Estelle; Skiles, J. W.; Seitz, Jeffery C.; Dantoni, Hector L.

1998-01-01

The ALERT (Augmented Learning Environment for Renewable Teaching) Project is a cooperative California-based program with two main partners: California State University (CSU) geoscience and education departments and two NASA Centers, the Jet Propulsion Laboratory (JPL) in Pasadena and the Ames Research Center (ARC) in Mountain View. This paper presents an example of how a NASA research effort can be used in the undergraduate classroom. A study, now in the fourth year, subjects test plants to exposures of varying solar ultraviolet (UV) radiation (280 - 340 nm); a full solar UV exposure, a solar UV exposure less about 14% of ambient UV flux, and a UV-blocked regime. This experiment is simple in that only modest amounts of expense are required yet it is elegant since only one variable, UV-flux is involved. The experiment lends itself to teaching several of the Earth Sciences because it uses information from botany, taxonomy, and ecology. Aspects of physics are inherent in the study since portions of the electromagnetic spectrum are studied. Further, since only one of many variables are manipulated, UV flux, the study demonstrates how the scientific method is used in formulating and testing hypotheses. Based on the ALERT experience this summer, this study will be implemented at a CSU campus with the expectation that it will serve as a pedagogical tool and where it will involve students in actual research.

Ocular ultraviolet radiation exposure of welders.

Science.gov (United States)

Tenkate, Thomas D

2017-05-01

reference made to the average solar UVR exposure of a Danish outdoor worker being 22 400 J/m 2 per year (min-max 5400 - 66 900 J/m 2 per year) (10). For comparison, taking the mean 8-hour UVR dose within the welding helmets as 15 mJ/cm2 (3), this would equate to an annual ocular/facial UVR dose for welders of 37 500 J/m 2 (at 5 days/week, 50 weeks/year). Even though this value is weighted for the ACGIH action spectrum, and the value for the Danish outdoor workers is weighted for the erythema spectrum, it provides a reasonable comparison and indicates that welders are likely to receive comparable facial/ocular UVR doses to outdoor workers. Slagor et al also state that "it is inferred that welders are not exposed to large amounts of UVR during their work life, in spite of the photokeratoconjunctivitis incidents" (1, p451). I would propose that the UVR dosimetry studies described above (2, 3), taken together with studies on UVR emissions of welding arcs which show that the MPE for many welding arcs can be exceeded in a matter of seconds (11-13), indicate that welders do work in an extreme UVR environment. These studies also suggest that welders are regularly exposed to levels of UVR that exceed the occupational exposure limits at body sites which are thought to be protected (eg, face and eyes) (2, 3). When these exposures are further considered in light of the range of eye conditions reported to occur in welders (14-17), the importance of implementing a comprehensive eye safety strategy for welders and all workers in a welding environment is imperative. References 1. Slagor RM, La Cour M, Bonde JP. The risk of cataract in relation to metal arc welding. Scan J Work Environ Health. 2016;42(5):447-53. https://doi.org/10.5271/sjweh.3572.  2. Shehade SA, Roberts PJ, Diffey BF, Foulds IS. Photodermatitis due to spot welding. Br J Dermatol. 1987;117:117-9. https://doi.org/10.1111/j.1365-2133.1987.tb04100.x.  3. Tenkate TD, Collins MJ. Personal ultraviolet radiation exposure of

Effects of solar PAR and UV radiation on tropical biofouling communities

KAUST Repository

Dobretsov, SV

2010-03-08

We investigated the effect of solar ultraviolet radiation (UVR) and photosynthetically active radiation (PAR) on the development of tropical micro- and macrofouling communities for 30 d. The experimental design involved 3 treatments: full spectrum (PAR+UVR), PAR only, and minimal light (reduced PAR and UVR). Terminal restriction fragment length polymorphism analysis demonstrated that different light conditions resulted in the formation of highly different microbial communities. The lowest densities of bacteria were found under the full spectrum treatment, while the lowest densities of diatoms were found in the minimal light treatment. Macrofouling communities consisted of 13 species and differed among light treatments. In the presence of UVR, communities had low species diversity, evenness, and richness, while in minimal light and PAR treatments, communities had high species diversity, evenness, and richness. Similarity percentage (SIMPER) analysis revealed that the tubeworm Hydroides elegans, the alga Ulva (Enteromorpha) sp., and the bivalve Perna viridis were the species responsible for most of the dissimilarities in macrofouling communities among treatments. While densities of H. elegans were similar in the PAR and minimal light treatments, this polychaete had higher growth rates under minimal light conditions. We conclude that UVR and PAR directly control the development of shallow micro- and macrofouling communities by inhibiting the recruitment and growth of sensitive species and promoting the growth of resistant species, but also that these forms of solar radiation influence the surface cues available to competent larvae by altering the development of the microbial community.

Channel catfish response to ultraviolet-B radiation

Science.gov (United States)

Ewing, M.S.; Blazer, V.S.; Fabacher, D.L.; Little, E.E.; Kocan, K.M.

1999-01-01

Fingerling channel catfish Ictalurus punctatus exposed to simulated ultraviolet-B radiation at an average daily dose of 2.9 J/cm2 were quite sensitive to the radiation. After a 24-h exposure, thinning of the most dorsal epidermis frequently was accompanied by edema. Compared with epidermis of unexposed fish, mucous cells in exposed fish were less superficial and club cells were less numerous both dorsally and high on the lateral surface of the body. Sunburn cells with pyknotic nuclei were evident in the epidermis of exposed fish. Among fish exposed for 48 h, focal necrosis and sloughing of the outer epidermal layer were widespread. A methanol-extractable skin substance that is associated with resistance to sunburn in other fish species was not detected in channel catfish.

NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM ...

African Journals Online (AJOL)

NEW MODEL FOR SOLAR RADIATION ESTIMATION FROM MEASURED AIR TEMPERATURE AND ... Nigerian Journal of Technology ... Solar radiation measurement is not sufficient in Nigeria for various reasons such as maintenance and ...

Effect of ultraviolet radiation absorbing film on pollination work of foreign bumblebee [Bombus terrestris

International Nuclear Information System (INIS)

Nishiguchi, I.

1999-01-01

The transmitted light through the ultraviolet radiation absorbing (UVA) film has a preventing effect of disease and pest occurrence. To develop the agriculture harmonized with the ecosystem, we attempted to research a further possible utilization of the UVA film. Pollination work of foreign bumblebee (Bombus terrestris) in the greenhouses roofed with UVA film and with common film for agriculture was examined in growing fruit-vegetables. The bumblebees used were not acclimatized to environmental conditions of the greenhouses. They visited flowers and gathered pollen from flowered crops grown in both houses, irrespective of the kind of film covering over the greenhouse roof, and the pollen quantity gathered was far greater in crops which produced in large quantity of pollen. Thus, the bumblebees were capable to work under the condition lacking in ultraviolet radiation. This pollinating behavior is different from that of honeybees. Then we concluded that bumblebees functioned well as an efficient pollinator under the condition without ultraviolet radiation

School students' knowledge and understanding of the Global Solar ...

African Journals Online (AJOL)

Background. The Global Solar Ultraviolet Index (UVI) is a health communication tool used to inform the public about the health risks of excess solar UV radiation and encourage appropriate sun-protection behaviour. Knowledge and understanding of the UVI has been evaluated among adult populations but not among ...

Phototherapy cabinet for ultraviolet radiation therapy

International Nuclear Information System (INIS)

Horwitz, S.N.; Frost, P.

1981-01-01

A newly designed cabinet can be used for the treatment of psoriasis with fluorescent ultraviolet (UV) lamps. the new design provides more uniform distribution of UV radiation in both the horizontal and vertical axes, and several safety features have been added. The distribution and uniformity of UV output in this and in a previously described cabinet are compared. The UV output at the vertical center of the older UV light cabinet was six times greater than that at either the top or bottom, while the design of the present cabinet provides uniform UV radiation except for a slight increase at head height and at the level of the lower legs compared with the middle third of the cabinet. The variation in output of the older cabinet may, in part, explain the commonly encountered difficulty in the phototherapy of psoriasis of the scalp and lower extremities

Sterilization techniques without heating (ultraviolet ray, radiation and ozone)

International Nuclear Information System (INIS)

Ito, Hitoshi

1991-01-01

The recent demand of consumers for processed foods is characterized by the intention for health and nature, besides, the demand for low sweetness, salt reduction, no additive and freshness becomes strong. In view of the control of microorganisms in products, all these become the negative factors. Accordingly, in order to overcome them, it is urgently desired to develop new technology or to improve conventional methods. As to heating sterilization, the uniform temperature treatment to the inside of foods is difficult, and it cannot be applied to perishables. The high temperature sterilization above 120degC causes the change in nutrition composition and physical properties. Ultraviolet ray and ozone can be used for the sterilization of food surface and powder and liquid foods. Radiation treatment can be applied to packed foods and frozen foods as well as food surface. The principle and the fields of application of ultraviolet ray sterilization, radiation sterilization and ozone sterilization are reported. In the mechanism of these methods, the action to DNA and oxidation are common. (K.I.)

Estimation of Solar Radiation using Artificial Neural Network

Directory of Open Access Journals (Sweden)

Slamet Suprayogi

2004-01-01

Full Text Available The solar radiation is the most important fator affeccting evapotranspiration, the mechanism of transporting the vapor from the water surface has also a great effect. The main objectives of this study were to investigate the potential of using Artificial Neural Network (ANN to predict solar radiation related to temperature. The three-layer backpropagation were developed, trained, and tested to forecast solar radiation for Ciriung sub Cachment. Result revealed that the ANN were able to well learn the events they were trained to recognize. Moreover, they were capable of effecctively generalize their training by predicting solar radiation for sets unseen cases.

Modeling the survivability of brucella to exposure of Ultraviolet radiation and temperature

Science.gov (United States)

Howe, R.

Accumulated summation of daily Ultra Violet-B (UV-B = 290? to 320 ? ) data? from The USDA Ultraviolet Radiation Monitoring Program show good correlation (R^2 = 77%) with daily temperature data during the five month period from February through June, 1998. Exposure of disease organisms, such as brucella to the effects of accumulated UV-B radiation, can be modeled for a 5 month period from February through June, 1998. Estimates of a lethal dosage for brucell of UV-B in the environment is dependent on minimum/maximum temperature and Solar Zenith Angle for the time period. The accumulated increase in temperature over this period also effects the decomposition of an aborted fetus containing brucella. Decomposition begins at some minimum daily temperature at 27 to 30 degrees C and peaks at 39 to 40C. It is useful to view the summation of temperature as a threshold for other bacteria growth, so that accumulated temperature greater than some value causes decomposition through competition with other bacteria and brucella die from the accumulated effects of UV-B, temperature and organism competition. Results of a study (Cook 1998) to determine survivability of brucellosis in the environment through exposure of aborted bovine fetuses show no one cause can be attributed to death of the disease agent. The combination of daily increase in temperature and accumulated UV-B radiation reveal an inverse correlation to survivability data and can be modeled as an indicator of brucella survivability in the environment in arid regions.

Ultraviolet radiation-induced carcinogenesis: mechanisms and experimental models

International Nuclear Information System (INIS)

Ramasamy, Karthikeyan; Shanmugam, Mohana; Balupillai, Agilan; Govindhasamy, Kanimozhi; Gunaseelan, Srithar; Muthusamy, Ganesan; Robert, Beualah Mary; Nagarajan, Rajendra Prasad

2017-01-01

Ultraviolet radiation (UVR) is a very prominent environmental toxic agent. UVR has been implicated in the initiation and progression of photocarcinogenesis. UVR exposure elicits numerous cellular and molecular events which include the generation of inflammatory mediators, DNA damage, epigenetic modifications, and oxidative damages mediated activation of signaling pathways. UVR-initiated signal transduction pathways are believed to be responsible for tumor promotion effects. UVR-induced carcinogenic mechanism has been well studied using various animal and cellular models. Human skin-derived dermal fibroblasts, epidermal keratinocytes, and melanocytes served as excellent cellular model systems for the understanding of UVR-mediated carcinogenic events. Apart from this, scientists developed reconstituted three-dimensional normal human skin equivalent models for the study of UVR signaling pathways. Moreover, hairless mice such as SKH-1, devoid of Hr gene, served as a valuable model for experimental carcinogenesis. Scientists have also used transgenic mice and dorsal portion shaved Swiss albino mice for UVR carcinogenesis studies. In this review, we have discussed the current progress in the study on ultraviolet B (UVB)-mediated carcinogenesis and outlined appropriate experimental models for both ultraviolet A- and UVB-mediated carcinogenesis. (author)

Annual cycle of solar radiation in a deciduous forest

International Nuclear Information System (INIS)

Hutchison, B.A.; Matt, D.R.

1977-01-01

Periodic solar radiation measurements within and above an east Tennessee Liriodendron forest and continuous records of insolation from a nearby NOAA weather station were used to derive an approximation of the animal radiation regime within and above the deciduous forest. The interaction of changing solar elevations, insolation, and forest phenology are shown to control the radiation climate within the forest. Maximum radiation penetrates the forest in early spring as solar paths rise higher in the sky each day just prior to leaf expansion. After leaf expansion begins, average radiation received within the forest decreases rapidly despite continued increases in solar elevations and daily insolation. This forest attains full leaf in early June and from then until the advent of leaf abscission near the autumnal equinox, forest structure remains relatively static. Solar elevations and daily insolation decline following the summer solstice, however, and as a result, average radiation penetrating the forest slowly declines throughout the summer reaching an annual minimum in early autumn. With leaf fall, slightly increased amounts of radiation penetrate the forest but as within-forest solar paths continue to lengthen, radiation within the forest again declines. Minimum amounts of solar radiation penetrate the leafless forest around the winter solstice

High mortality of Red Sea zooplankton under ambient solar radiation.

Science.gov (United States)

Al-Aidaroos, Ali M; El-Sherbiny, Mohsen M O; Satheesh, Sathianeson; Mantha, Gopikrishna; Agustī, Susana; Carreja, Beatriz; Duarte, Carlos M

2014-01-01

High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation). The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM) 18.4±5.8% h(-1), five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM) 12±5.6 h(-1)% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

High mortality of Red Sea zooplankton under ambient solar radiation.

Directory of Open Access Journals (Sweden)

Ali M Al-Aidaroos

Full Text Available High solar radiation along with extreme transparency leads to high penetration of solar radiation in the Red Sea, potentially harmful to biota inhabiting the upper water column, including zooplankton. Here we show, based on experimental assessments of solar radiation dose-mortality curves on eight common taxa, the mortality of zooplankton in the oligotrophic waters of the Red Sea to increase steeply with ambient levels of solar radiation in the Red Sea. Responses curves linking solar radiation doses with zooplankton mortality were evaluated by exposing organisms, enclosed in quartz bottles, allowing all the wavelengths of solar radiation to penetrate, to five different levels of ambient solar radiation (100%, 21.6%, 7.2%, 3.2% and 0% of solar radiation. The maximum mortality rates under ambient solar radiation levels averaged (±standard error of the mean, SEM 18.4±5.8% h(-1, five-fold greater than the average mortality in the dark for the eight taxa tested. The UV-B radiation required for mortality rates to reach ½ of maximum values averaged (±SEM 12±5.6 h(-1% of incident UVB radiation, equivalent to the UV-B dose at 19.2±2.7 m depth in open coastal Red Sea waters. These results confirm that Red Sea zooplankton are highly vulnerable to ambient solar radiation, as a consequence of the combination of high incident radiation and high water transparency allowing deep penetration of damaging UV-B radiation. These results provide evidence of the significance of ambient solar radiation levels as a stressor of marine zooplankton communities in tropical, oligotrophic waters. Because the oligotrophic ocean extends across 70% of the ocean surface, solar radiation can be a globally-significant stressor for the ocean ecosystem, by constraining zooplankton use of the upper levels of the water column and, therefore, the efficiency of food transfer up the food web in the oligotrophic ocean.

Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health.

Science.gov (United States)

Holick, Michael F

2016-03-01

Humans evolved in sunlight and had depended on sunlight for its life giving properties that was appreciated by our early ancestors. However, for more than 40 years the lay press and various medical and dermatology associations have denounced sun exposure because of its association with increased risk for skin cancer. The goal of this review is to put into perspective the many health benefits that have been associated with exposure to sunlight, ultraviolet A (UVA) ultraviolet B (UVB), visible and infrared radiation. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Occupational standard for exposure to ultraviolet radiation (1989)

International Nuclear Information System (INIS)

1989-12-01

The exposure limit (EL) values in this standard refer to ultraviolet radiation (UVR) in the spectral region between 180 and 400 nm and represents conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. The EL values for exposure of the eye or the skin may be used to evaluate potentially hazardous exposure from UVR. The limits do not apply to ultraviolet lasers. The values should be used as guides in the control of exposure to both pulsed and continuous sources of UVR where the exposure duration is not less than 0.1 μsec. The ELs are below levels used for UV exposures of patients as a part of medical treatment or for elective cosmetic purposes. They are intended as upper limits for non therapeutic and non cosmetic exposure. 2 refs., 2 tabs

Biological effect of ultraviolet radiation on cattle: bovine ocular squamous cell carcinoma

International Nuclear Information System (INIS)

Kopecky, K.E.; Pugh, G.W. Jr.; Hughes, D.E.; Booth, G.D.; Cheville, N.F.

1979-01-01

The relationship between bovine ocular squamous cell carcinoma and ultraviolet radiation was studied. Experimental procedures were devised to irradiate cattle with predetermined quantities of ultraviolet beta. Irradiation induced a preneoplastic ocular growth in one of four irradiated cattle. An epizootiologic study indicates that since 1950 the occurrence of bovine ocular squamous cell carcinoma reported at slaughter has increased. This increase was real and not due to an increase in numbers of cattle

Solar Radiation Model for Development and Control of Solar Energy Sources

Directory of Open Access Journals (Sweden)

Dominykas Vasarevičius

2016-06-01

Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.

Ultraviolet light and infrared radiation. Measurement and hazard assessment

International Nuclear Information System (INIS)

Mayer, A.; Salsi, S.

1979-01-01

Ultraviolet, light and infrared radiation exists in many work places and can be dangerous in many ways, especially for the eyes. The INRS has developed a method and an apparatus for measuring on site or in a laboratory the spectral energy distribution of such radiation and the luminance of the source. With current knowledge of the effects of radiation on the eyes and by comparing readings taken and recommended limit values, it is possible to determine the risk levels at work places in the different wave ranges. Two examples of readings taken at a pot furnace in a crystal glass factory and at an MAG welding station are given and the appropriate protective measures described [fr

A mechanism for solar ultraviolet flux variability

International Nuclear Information System (INIS)

Schatten, K.H.; Heath, D.F.

1981-01-01

Solar UV emission observed by a filter photometer on Nimbus IV from 1969 to 1973 is examined in an attempt to understand the short term (27 day) and secular variability. Two models are discussed to explain the variations - a calcium plage model and a chromospheric network (faculae and spicule) structure model. Both relate to the remnant magnetic fields of active regions. An association between UV brightenings and the large scale magnetic field has been found consistent with the network model. An increase in UV emittance can be achieved by raising the effective chromospheric temperature closer to a photospheric level. If the Sun's luminosity is constant on these time intervals the enhanced UV radiation could be partially offset by an overall decrease in photospheric temperature as measured by Livingston in visible photospheric profiles. Total solar luminosity may then show less variability, however, the UV to visible luminosity variation may have significant planetary influences. Lockwood and Thompson (1979) report a relation between solar activity and planetary albedos, and Schatten (1979) discussed a long-suspected relationship between solar activity and the Great Red Spot appearance. (orig.)

Solar energy R + D programme, 1979-1983. Project F: solar radiation data

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

Individual presentations report work in the following areas: production of test reference years for model simulation of solar systems and components; global radiation atlas for horizontal surfaces; radiation data on inclined surfaces; intensity thresholds and cumulative frequency curves; useful energy output from solar collectors; network comparison of pyranometers; measurements of turbidity, spectral radiation, etc.; satellite data. (LEW)

Norathyriol Suppresses Skin Cancers Induced by Solar Ultraviolet Radiation by Targeting ERK Kinases

Energy Technology Data Exchange (ETDEWEB)

Li, Jixia; Malakhova, Margarita; Mottamal, Madhusoodanan; Reddy, Kanamata; Kurinov, Igor; Carper, Andria; Langfald, Alyssa; Oi, Naomi; Kim, Myoung Ok; Zhu, Feng; Sosa, Carlos P.; Zhou, Keyuan; Bode, Ann M.; Dong, Zigang (Cornell); (Guangdong); (UMM)

2012-06-27

Ultraviolet (UV) irradiation is the leading factor in the development of skin cancer, prompting great interest in chemopreventive agents for this disease. In this study, we report the discovery of norathyriol, a plant-derived chemopreventive compound identified through an in silico virtual screening of the Chinese Medicine Library. Norathyriol is a metabolite of mangiferin found in mango, Hypericum elegans, and Tripterospermum lanceolatum and is known to have anticancer activity. Mechanistic investigations determined that norathyriol acted as an inhibitor of extracellular signal-regulated kinase (ERK)1/2 activity to attenuate UVB-induced phosphorylation in mitogen-activated protein kinases signaling cascades. We confirmed the direct and specific binding of norathyriol with ERK2 through a cocrystal structural analysis. The xanthone moiety in norathyriol acted as an adenine mimetic to anchor the compound by hydrogen bonds to the hinge region of the protein ATP-binding site on ERK2. Norathyriol inhibited in vitro cell growth in mouse skin epidermal JB6 P+ cells at the level of G{sub 2}-M phase arrest. In mouse skin tumorigenesis assays, norathyriol significantly suppressed solar UV-induced skin carcinogenesis. Further analysis indicated that norathyriol mediates its chemopreventive activity by inhibiting the ERK-dependent activity of transcriptional factors AP-1 and NF-{kappa}B during UV-induced skin carcinogenesis. Taken together, our results identify norathyriol as a safe new chemopreventive agent that is highly effective against development of UV-induced skin cancer.

Obliquity Modulation of the Incoming Solar Radiation

Science.gov (United States)

Liu, Han-Shou; Smith, David E. (Technical Monitor)

2001-01-01

Based on a basic principle of orbital resonance, we have identified a huge deficit of solar radiation induced by the combined amplitude and frequency modulation of the Earth's obliquity as possibly the causal mechanism for ice age glaciation. Including this modulation effect on solar radiation, we have performed model simulations of climate change for the past 2 million years. Simulation results show that: (1) For the past 1 million years, temperature fluctuation cycles were dominated by a 100-Kyr period due to amplitude-frequency resonance effect of the obliquity; (2) From 2 to 1 million years ago, the amplitude-frequency interactions. of the obliquity were so weak that they were not able to stimulate a resonance effect on solar radiation; (3) Amplitude and frequency modulation analysis on solar radiation provides a series of resonance in the incoming solar radiation which may shift the glaciation cycles from 41-Kyr to 100-Kyr about 0.9 million years ago. These results are in good agreement with the marine and continental paleoclimate records. Thus, the proposed climate response to the combined amplitude and frequency modulation of the Earth's obliquity may be the key to understanding the glaciation puzzles in paleoclimatology.

Evaluation of solar radiation abundance and electricity production capacity for application and development of solar energy

Energy Technology Data Exchange (ETDEWEB)

Rahim, Mustamin [Department of Architecture, Khairun University, Ternate (Indonesia); Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan); Yoshino, Jun; Yasuda, Takashi [Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University (Japan)

2012-07-01

This study was undertaken to analyze solar radiation abundance to ascertain the potential of solar energy as an electrical energy resource. Local weather forecasting for predicting solar radiation is performed using a meteorological model MM5. The prediction results are compared with observed results obtained from the Japan Meteorological Agency for verification of the data accuracy. Results show that local weather forecasting has high accuracy. Prediction of solar radiation is similar with observation results. Monthly average values of solar radiation are sufficiently good during March–September. Electrical energy generated by photovoltaic cells is almost proportional to the solar radiation amount. Effects of clouds on solar radiation can be removed by monthly averaging. The balance between supply and demand of electricity can be estimated using a standard curve obtained from the temporal average. When the amount of solar radiation every hour with average of more than 100 km radius area does not yield the standard curve, we can estimate the system of storage and auxiliary power necessary based on the evaluated results of imbalance between supply and demand.

MEASUREMENT OF SURFACE SOLAR UV-B RADIATION AT TROPICAL COASTAL STATION BAKKHALI IN WEST BENGAL, INDIA

OpenAIRE

R. BHATTACHARYA; A. BHOUMICK

2012-01-01

Surface solar ultraviolet irradiance has been measured at Bakkhali (21.8ºN, 87.8ºE), a tropical rural station on the coast of Bay of Bengal, India in West Bengal. The measurements show a remarkable variation in UV-B load exists with a peak value at noon. The blockage of direct UV radiation in mangrove forest of costal site appears low when compared with UV load beneath the multiple trees of Mangifera indica in an inland site of Kalyani (22058' N, 88028' E), West Bengal. Mangrove forests have ...

Evaluation of conventional and high-performance routine solar radiation measurements for improved solar resource, climatological trends, and radiative modeling

Energy Technology Data Exchange (ETDEWEB)

Gueymard, Christian A. [Solar Consulting Services, P.O. Box 392, Colebrook, NH 03576 (United States); Myers, Daryl R. [National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401-3305 (United States)

2009-02-15

The solar renewable energy community depends on radiometric measurements and instrumentation for data to design and monitor solar energy systems, and develop and validate solar radiation models. This contribution evaluates the impact of instrument uncertainties contributing to data inaccuracies and their effect on short-term and long-term measurement series, and on radiation model validation studies. For the latter part, transposition (horizontal-to-tilt) models are used as an example. Confirming previous studies, it is found that a widely used pyranometer strongly underestimates diffuse and global radiation, particularly in winter, unless appropriate corrective measures are taken. Other types of measurement problems are also discussed, such as those involved in the indirect determination of direct or diffuse irradiance, and in shadowband correction methods. The sensitivity of the predictions from transposition models to inaccuracies in input radiation data is demonstrated. Caution is therefore issued to the whole community regarding drawing detailed conclusions about solar radiation data without due attention to the data quality issues only recently identified. (author)

Altmetric: 165More detailArticle | OPENClimate change-induced increases in precipitation are reducing the potential for solar ultraviolet radiation to inactivate pathogens in surface waters

Science.gov (United States)

Climate change is accelerating the release of dissolved organic matter (DOM) to inland and coastal waters through increases in precipitation, thawing of permafrost, and changes in vegetation. Our modeling approach suggests that the selective absorption of ultraviolet radiation (U...

Solar ultraviolet photodegradation of DOC may stimulate freshwater food webs

NARCIS (Netherlands)

Lange, de H.J.; Morris, D.P.; Williamson, C.E.

2003-01-01

The UV component in solar radiation increased the availability of DOC for bacterial growth, and led to an increase in bacterial and bacterivore abundance in laboratory plankton cultures. UV radiation may thus stimulate ecosystem productivity by increasing dissolved organic carbon lability and

A simple solar radiation index for wildlife habitat studies

Science.gov (United States)

Keating, Kim A.; Gogan, Peter J.; Vore, John N.; Irby, Lynn R.

2007-01-01

Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretically striking an arbitrarily oriented surface during the hour surrounding solar noon on the equinox. Because it derives from first geometric principles and is linearly distributed, SRI offers clear advantages over aspect-based surrogates. The SRI also is superior to hillshade, which we found to be sometimes imprecise and ill-behaved. To illustrate application of our SRI, we assessed niche separation among 3 ungulate species along a single environmental axis, solar radiation, on the northern Yellowstone winter range. We detected no difference between the niches occupied by bighorn sheep (Ovis canadensis) and elk (Cervus elaphus; P = 0.104), but found that mule deer (Odocoileus hemionus) tended to use areas receiving more solar radiation than either of the other species (P solar radiation component.

DNA replication and repair in Tilapia cells. 1. The effect of ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Yew, F.H.; Chang, L.M. (National Taiwan Univ., Taipei (China))

1984-12-01

The effect of ultraviolet radiation on a cell line established from the warm water fish Tilapia has been assessed by measuring the rate of DNA synthesis, excision repair, post-replication repair and cell survival. The cells tolerate ultraviolet radiation better than mammalian cells with respect to DNA synthesis, post-replication repair and cell survival. They are also efficient in excision repair, which in other fish cell lines has been found to be at a low level or absent. Their response to the inhibitors hydroxyurea and 1-..beta..-D-arabinofuranosylcytosine is less sensitive than that of other cell lines, yet the cells seem to have very small pools of DNA precursor.

Animal model for evaluation of topical photoprotection against ultraviolet A (320-380 nm) radiation

International Nuclear Information System (INIS)

Chew, S.; DeLeo, V.A.; Harber, L.C.

1987-01-01

Recent studies reporting UVA (ultraviolet A radiation 320-380 nm) as an integral part of the cumulative sun-induced damage in human skin have prompted an interest in developing effective UVA photoprotective agents. The development of such compounds has been impeded by the absence of a clinically relevant animal model for evaluating their efficacy. This report describes the development and use of such a laboratory animal system. Selected concentrations of oxybenzone (2-hydroxy-4-methoxybenzophenone) in vehicle (0.1% to 6%) or vehicle alone were applied to the depilated dorsal skin of 30 Hartley strain female albino guinea pigs. The skin was irradiated with solar simulated UVA from a xenon light source. Acute radiation-induced damage was assayed by erythema grading and inhibition of [ 3 H]thymidine incorporation into epidermal DNA. Data from erythema grading studies indicated that a significant degree of photoprotection was achieved with 6%, 3%, and 1% solutions of benzophenone compared with the control vehicle; the 6% solution was significantly more photoprotective than the 3% and 1% solutions. A 6% solution afforded significant photoprotection when assayed by [ 3 H]thymidine incorporation

Climate hypersensitivity to solar forcing?

Directory of Open Access Journals (Sweden)

W. Soon

2000-05-01

Full Text Available We compare the equilibrium climate responses of a quasi-dynamical energy balance model to radiative forcing by equivalent changes in CO2, solar total irradiance (Stot and solar UV (SUV. The response is largest in the SUV case, in which the imposed UV radiative forcing is preferentially absorbed in the layer above 250 mb, in contrast to the weak response from global-columnar radiative loading by increases in CO2 or Stot. The hypersensitive response of the climate system to solar UV forcing is caused by strongly coupled feedback involving vertical static stability, tropical thick cirrus ice clouds and stratospheric ozone. This mechanism offers a plausible explanation of the apparent hypersensitivity of climate to solar forcing, as suggested by analyses of recent climatic records. The model hypersensitivity strongly depends on climate parameters, especially cloud radiative properties, but is effective for arguably realistic values of these parameters. The proposed solar forcing mechanism should be further confirmed using other models (e.g., general circulation models that may better capture radiative and dynamical couplings of the troposphere and stratosphere.Key words: Meteorology and atmospheric dynamics (climatology · general or miscellaneous · Solar physics · astrophysics · and astronomy (ultraviolet emissions

Orbiter radiator panel solar focusing test

Science.gov (United States)

Howell, H. R.; Rankin, J. G.

1983-01-01

Test data are presented which define the area around the Orbiter radiator panels for which the solar reflections are concentrated to one-sun or more. The concave shape of the panels and their specular silver/Teflon coating causes focusing of the reflected solar energy which could have adverse heating effects on equipment or astronaut extravehicular activity (EVA) in the vicinity of the radiator panels. A room ambient test method was utilized with a one-tenth scale model of the radiator panels.

Ultraviolet-induced responses in two species of climax tropical marine macrophytes.

Science.gov (United States)

Detrés, Y; Armstrong, R A; Connelly, X M

2001-09-01

In tropical regions nominal reductions in stratospheric ozone could be detrimental to marine organisms that live near their upper tolerance levels of ultraviolet (UV) radiation and temperature. Well-known plant responses to UV include inhibition of photosynthesis, reductions in chlorophyll content, morphological changes and production of UV absorbing compounds such as flavonoids. An assessment of the effects and responses of two tropical marine macrophytes to full solar radiation and solar radiation depleted of UV were conducted in southwestern Puerto Rico. Changes in concentration of photosynthetic and photoprotective pigments, and in leaf optical properties of the red mangrove Rhizophora mangle and the seagrass Thalassia testudinum, were evaluated in field exclusion experiments. Rhizophora mangle exposed to full solar radiation showed lower leaf reflectance and a shift of 5 nm in the inflection point of the red edge. Thalassia testudinum samples excluded from UV had significant increases in total chlorophyll and carotenoid concentrations. These marine macrophytes showed increments in their concentration of UV-B absorbing compounds with exposure to UV radiation. Results indicate that even minor increases in UV radiation at low latitudes could have significant effects on the pigment composition of these climax species.

Skin Erythema, Pigmentation and Hydration Kinetics after Ultraviolet Radiation-induced Photodamage in Southern Chinese Women.

Science.gov (United States)

Wan, Miaojian; Hu, Rong; Xie, Xiaoyuan; Gong, Zijian; Yi, Jinling; Chen, Haiyan; Xie, Lin; Guan, Xiaomin; Guan, Lei; Lai, Wei

2017-10-01

Although there have been some studies about changes of skin erythema and pigmentation following ultraviolet radiation in other races, the relevant data in Chinese have never been achieved. Thus, we evaluated the long-time course of skin erythema, pigmentation and hydration changes after different doses of solar-simulated ultraviolet (SSUV) irradiation in 26 Chinese women for 168 days. The erythema index increased abruptly and peaked during 3 days of SSUV exposure, then slowly returned to the baseline level starting at day 7 and completely recovered during 168-day course of this study only in one minimal erythema doses (MED) SSUV irradiation. The melanin index started to slowly increase at day 3 of SSUV exposure, peaking at day 14 and gradually returned to the baseline level thereafter, but did not return to the baseline level during 168-day course in all doses. Skin hydration slowly declined at day 3 of exposure, hitting the lowest point at day 7, then slowly recovered starting at day 14 and completely returned to the baseline level at day 28 only in 1.5MED. These results will serve as baseline data on Chinese skin and provide useful references for the treatment of serious skin photodamage in Chinese. © 2017 The American Society of Photobiology.

Correlation between endogenous glutathione content and sensitivity of cultured human skin cells to radiation at defined wavelengths in the solar ultraviolet range

International Nuclear Information System (INIS)

Tyrrell, R.M.; Pidoux, M.

1988-01-01

Glutathione depletion of cultured human skin fibroblasts by treatment with buthionine-S.R.-sulfoximine (BSO) sensitises them to solar UV radiation. We now show that there is a close quantitative correlation between cellular glutathione content and sensitivity to radiation at 365 nm. A weaker correlation is observed when cells are depleted of glutathione using diethylmaleimide. Both fibroblasts and epidermal keratinocytes derived from the same foreskin biopsy are sensitised to radiation at 313 nm by glutathione depletion. At low to intermediate fluence levels, 10 mM cysteamine present during irradiation at 302 nm is able to almost completely reverse the sensitising effects of glutathione depletion suggesting that the endogenous thiol protects against radiation at this wavelength by a free radical scavenging mechanism. At 313 nm, the sensitisation is not reversed by cysteamine suggesting that glutathione plays a more specific role in protection against radiation at longer wavelengths. Xeroderma pigmentosum group A fibroblasts (excision deficient) are also sensitised to radiation at 313 and 365 nm by depletion of glutathione. The results provide further evidence that endogenous glutathione is involved in protecting human skin cells against a wide range of solar radiation damage. (author)

ANALYSIS OF MEASURED AND MODELED SOLAR RADIATION AT THE TARS SOLAR HEATING PLANT IN DENMARK

DEFF Research Database (Denmark)

Tian, Zhiyong; Perers, Bengt; Furbo, Simon

2017-01-01

, such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, Wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate...... collector field have been measured in Tars solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tars solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total......A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tars, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters...

Solar Maximum Mission Experiment - Ultraviolet Spectroscopy and Polarimetry on the Solar Maximum Mission

Science.gov (United States)

Tandberg-Hanssen, E.; Cheng, C. C.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.; Gurman, J. B.; Hyder, C. L.

1981-01-01

The Ultraviolet Spectrometer and Polarimeter on the Solar Maximum Mission spacecraft is described. It is pointed out that the instrument, which operates in the wavelength range 1150-3600 A, has a spatial resolution of 2-3 arcsec and a spectral resolution of 0.02 A FWHM in second order. A Gregorian telescope, with a focal length of 1.8 m, feeds a 1 m Ebert-Fastie spectrometer. A polarimeter comprising rotating Mg F2 waveplates can be inserted behind the spectrometer entrance slit; it permits all four Stokes parameters to be determined. Among the observing modes are rasters, spectral scans, velocity measurements, and polarimetry. Examples of initial observations made since launch are presented.

Effect of solar UV/EUV heating on the intensity and spatial distribution of Jupiter's synchrotron radiation

Science.gov (United States)

Kita, H.; Misawa, H.; Tsuchiya, F.; Tao, C.; Morioka, A.

2013-10-01

We analyzed the Very Large Array archived data observed in 2000 to determine whether solar ultraviolet (UV)/extreme ultraviolet (EUV) heating of the Jovian thermosphere causes variations in the total flux density and dawn-dusk asymmetry (the characteristic differences between the peak emissions at dawn and dusk) of Jupiter's synchrotron radiation (JSR). The total flux density varied by 10% over 6 days of observations and accorded with theoretical expectations. The average dawn-dusk peak emission ratio indicated that the dawn side emissions were brighter than those on the dusk side and this was expected to have been caused by diurnal wind induced by the solar UV/EUV. The daily variations in the dawn-dusk ratio did not correspond to the solar UV/EUV, and this finding did not support the theoretical expectation that the dawn-dusk ratio and diurnal wind velocity varies in correspondence with the solar UV/EUV. We tried to determine whether the average dawn-dusk ratio could be explained by a reasonable diurnal wind velocity. We constructed an equatorial brightness distribution model of JSR using the revised Divine-Garrett particle distribution model and used it to derive a relation between the dawn-dusk ratio and diurnal wind velocity. The estimated diurnal wind velocity reasonably corresponded to a numerical simulation of the Jovian thermosphere. We also found that realistic changes in the diurnal wind velocity could not cause the daily variations in the dawn-dusk ratio. Hence, we propose that the solar UV/EUV related variations were below the detection limit and some other processes dominated the daily variations in the dawn-dusk ratio.

Tl response of KMgF3: Lu + PTFE at ultraviolet radiation

International Nuclear Information System (INIS)

Gonzalez, P.R.; Alarcon, N.G.; Furetta, C.; Azorin, J.

2003-01-01

Ionizing radiation has different types of interaction with a crystalline solid. However, only few effects are interesting to optimize some thermoluminescent (Tl) properties of certain Tl materials. This paper presents results obtained by irradiating KMgF 3 : Lu + Ptfe Tl dosimeters with ultraviolet (UV) radiation previously exposed to gamma radiation. These results showed that those dosimeters not exposed previously to gamma radiation did not presented any Tl signal. Meanwhile, those previously submitted to gamma irradiation showed that their sensitivity was increased as the gamma dose increased. The glow curve of sensitized KMgF 3 : Lu + Ptfe exposed to UV radiation, presented the dosimetric pea at 212 C. This makes this material to be promissory for measuring UV radiation. (Author)

Models for prediction of global solar radiation on horizontal surface ...

African Journals Online (AJOL)

The estimation of global solar radiation continues to play a fundamental role in solar engineering systems and applications. This paper compares various models for estimating the average monthly global solar radiation on horizontal surface for Akure, Nigeria, using solar radiation and sunshine duration data covering years ...