scholarly journals ASSESSMENT OF ULTRAVIOLET (UV) RADIATION FROM TECHNICAL SOURCES/DIRBTINIŲ ŠALTINIŲ SKLEIDŽIAMOS UVA IR UVB SPINDULIUOTĖS ĮVERTINIMAS/ОПРЕДЕЛЕНИЕ УФА- И УФБ-ИЗЛУЧЕНИЙ ОТ ТЕХНОГЕННЫХ ИСТОЧНИКОВ

2009 ◽  
Vol 17 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Renata Chadyšienė ◽  
Aloyzas Girgždys
Keyword(s):  
Radiation Dose ◽  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Welding Process ◽  
The Sun ◽  
Uvb Radiation ◽  
The Earth ◽  
Uva Radiation ◽  
Made In

The paper presents the assessment of ultraviolet radiation from technical sources. It has been determined that the intensity of UVA radiation is about 10 times higher than the intensity of radiation of UVB. It has been investigated that the intensity of UV radiation during the welding process nonlinearly depends on the strength of the current, namely, if the strength of the current is reduced by 60%, the intensity of UV radiation is reduced by 20%, it also depends on the distance from the source, namely, if the distance is increased 10 times, the intensity of UV radiation is reduced about 25 times. The dose of UVA and UVB radiation from various resources is calculated. Comparison with the minimum erythema dose is submitted. It has been obtained that when the strength of the current is 315 A, the UV radiation dose exceeds 1 MED, namely, UVA ∼ 3000, UVB ∼300 times. After having carried out the experiment it has been found that the UV radiation emitted from a welder comprises about 80% of UVA, and about 20% of UVB. The results of investigation made in a solarium show that UV radiation from lamps comprises 98% of UVA radiation and 2% – of UVB radiation, while in the Sun rays reaching the Earth UV radiation comprises 96% of UVA and 4% of UVB. Santrauka Darbe radiometriniais metodais nustatyti ir įvertinti dirbtinių šaltinių skleidžiamos ultravioletinės alfa ir beta spinduliuotės (UVA ir UVB) intensyvumo pokyčiai ir apskaičiuota įvairių šaltinių sukuriama UVA ir UVB spinduliuotės dozė. Nustatyta, kad suvirinimo proceso metu skleidžiamos UV spinduliuotės intensyvumas priklauso nuo šaltinio intensyvumo (sumažinus šaltinio intensyvumą apie 60 %, UV spinduliuotės intensyvumas sumažėja apie 20 %) bei nuo atstumo nuo šaltinio (padidinus atstumą 10 kartų UV spinduliuotės intensyvumas sumažėja apie 25 kartus). Įvairių šaltinių sukuriama UVA ir UVB spinduliuotės dozė palyginama su minimalia eritemine doze. Gauta, kad suvirinimo metu, esant 315 A elektros srovės stipriui, UVA spinduliuotės dozė 1 MED viršija apie 3000, UVB ~ 300 kartų. Nustatyta, kad apie 80 % iš suvirinimo aparato skleidžiamos UV spinduliuotės yra UVA, o apie 20 % – UVB. 98 % soliariumo lempų skleidžiamos UV spinduliuotės yra UVA ir 2 % – UVB, gi iš Žemę pasiekiančios Saulės UV spinduliuotės 96 % yra UVA ir 4 % UVB. Резюме Радиометрическими методами определены изменения УФА- и УФБ-излучений некоторых техногенных источников, а также рассчитана доза УФА- и УФБ-излучений этих источников. Установлено, что в среднем интенсивность УФА-излучения в 10 раз сильнее интенсивности УФБ-излучения. Установлено также, что в процессе сварки интенсивность испускаемого УФ-излучения зависит от интенсивности источника: при снижении интенсивности источника на 60% интенсивность УФ-излучения снижается приблизительно на 20%; при увеличении расстояния от места сварки в 10 раз интенсивность УФ-излучения снижается приблизительно в 25 раз. Рассчитана доза УФАи УФБ-излучений, создаваемая различными техногенными источниками. Представлено ее сравнение с минимальной эритемной дозой. Получено, что во время сварки при силе электрического тока 315 А доза УФА-излучения превышает 1 МЭД в 3000 раз, а УФБ-излучения – в 300 раз. Экспериментальными исследованиями получено, что испускаемое при сварке УФ излучение на 80% состоит из УФА-излучения и на 20% – из УФБ-излучения. В соляриуме, где был проведен эксперимент, УФ-излучение ламп состоит на 98% из УФА лучей и на 2% из УФБ лучей. Для сравнения: околоземное УФ-излучение Солнца в Литве состоит в среднем на 96% из УФА лучей и на 4% из УФБ лучей.

scholarly journals Use of Flavonoids and Cinnamates, the Main Photoprotectors with Natural Origin

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Alesandra R. Nunes ◽  
Ícaro G. P. Vieira ◽  
Dinalva B. Queiroz ◽  
Antonio Linkoln Alves Borges Leal ◽  
Selene Maia Morais ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
The Sun ◽  
Uvb Radiation ◽  
Natural Origin ◽  
Cosmetic Industry ◽  
Response To Stress ◽  
A Minor ◽  
Plant Compounds ◽  
Cellular Alterations ◽  
Uva Radiation

Many pathological problems are initiated by ultraviolet radiation (UVR), such as skin cancer, the most commonly diagnosed cancer worldwide. The UVA (320–400 nm) and UVB (290–320 nm) wavelengths may cause effects such as photoaging, DNA damage, and a series of cellular alterations. The UVA radiation can damage the DNA, oxidize the lipids, and produce dangerous free radicals, which can cause inflammation, modify the gene expression in response to stress, and weaken the skin immune response. With a minor penetration, the UVB radiation is more harmful, being responsible for immediate damage. Ultraviolet radiation light emitted by the sun is considered necessary for the existence of life but cause radiation problems, especially in the skin. The photoprotective activities of plant extracts and isolated composts were evaluated by many reports, as well as the correlation of these compounds with the antioxidant activity. This review presents plant compounds with interest to the cosmetic industry to be used in sunscreens such as flavonoids and cinnamates.

ULTRAVIOLET RADIATION ALBEDO OF NATURAL SURFACES/NATŪRALIŲ PAVIRŠIŲ ULTRAVIOLETINĖS SPINDULIUOTĖS ALBEDAS/АЛЬБЕДО УЛЬТРАФИОЛЕТОВОГО ИЗЛУЧЕНИЯ НАТУРАЛЬНЫХ ПОВЕРХНОСТЕЙ

2008 ◽  
Vol 16 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Renata Chadyšienė ◽  
Aloyzas Girgždys
Keyword(s):  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Radiation Intensity ◽  
Surface Albedo ◽  
Spectral Response ◽  
Experimental Measurements ◽  
Uvb Radiation ◽  
Maximum Reduction ◽  
Measurement Results ◽  
Uva Radiation

This article presents measurement results of intensity of solar UVA and UVB radiation, as well as UV radiation albedo from various surfaces. The intensity of albedo was measured from natural surfaces, such as: sand, grass, water, and snow. The paper also presents measurements of solar emitted UVA and UVB radiation intensity in the shadow. Ultraviolet radiation intensity and surface albedo was measured using a handy UVA radiation radiometer UVA ‐ 365HA, with spectral response of 320–390 nm and a handy UVB radiation radiometer PMA2201, with spectral response of 280–320 nm. The results of measurements show that snow has the maximum albedo ‐ from 50 to 60 per cent, sand ‐ 10 per cent, and the minimum albedo is for grass ‐ 2 or 3 per cent. The data of experimental measurements of UVA and UVB radiation in the shadow show that maximum reduction of intensity of UVA radiation up to 80%, was at 1 p.m. in comparison with reduction of intensity of UVB radiation to 70% at 2 p.m. Santrauka Pateikti saules skleidžiamos UVA ir UVB spinduliuotes intensyvumo ir ivairiu paviršiu UV spinduliuotes albedo matavimu rezultatai. Matuotas ivairiu natūraliu paviršiu albedas: smelio, žoles, vandens, sniego. Ultravioletines spinduliuotes intensyvumas ir ivairiu paviršiu albedas matuotas nešiojamaisiais radiometrais: UVA spinduliuotes ‐ UVA‐365 HA, kurio daviklis registruoja UV spinduliuote nuo 320 iki 400 nm, ir UVB spinduliuotes‐PMA2201, kurio daviklis registruoja UV spinduliuote nuo 280 iki 320 nm. Atlikus eksperimentus nustatyta, kad iš natūraliu paviršiu didžiausias albedas yra sniego ‐ apie 80–90 %, smelio ‐ 10 %, mažiausias ‐ žoles, apie 2–3 %. Atlikta saules skleidžiamos UVA, UVB spinduliuotes intensyvumo ir šalia esančiu paviršiu albedo ryšio analize. Didžiausi koreliacijos koeficientai gauti: tarp UVA spinduliuotes intensyvumo ir smelio albedo (‐0,93), tarp UVA spinduliuotes intensyvumo ir žoles albedo (0,93), tarp UVB spinduliuotes intensyvumo ir smelio albedo (‐0,89). Atlikus UVA ir UVB spinduliuotes intensyvumo matavimus šešelyje, nustatyta, kad labiausiai UVA spinduliuote sumažeja apie 13 vai. (80 %), o UVB ‐ apie 14 vai. (70 %). Резюме Представлены результаты измерения интенсивности УФА и УФБ солнечного излучения, а также УФ альбедо различных поверхностей. Измерялись альбедо натуральных материалов: песка, травы, воды, снега. Интенсивность ультрафиолетового излучения и альбедо различных поверхностей измерялись переносными радиометрами: УФА излучение – УФА–365 HA, датчик которого регистрирует УФ излучение в пределах 320–400 нм, и УФБ излучение – РМА2201, датчик которого регистрирует УФ излучение в пределах 280–320 нм. Результаты экспериментов показали, что наибольшее альбедо у натуральных веществ: около 80–90 % – у снега, 10 % – у песка, наименьшее (около 2–3 %) – у травы. Проведен анализ связи между солнечной интенсивностью УФА излучения, УФБ излучения и альбедо находящихся рядом друг с другом поверхностей. Наибольшие коэффициенты корреляции получены между интенсивностью УФА излучения и альбедо песка (–0,93), между интенсивностью УФА излучения и альбедо травы (0,93), между интенсивностью УФБ излучения и альбедо песка (–0,89). После проведения измерений интенсивности УФА и УФБ излучений в тени установлено, что больше всего УФА излучение уменьшается около 13 ч (80 %), а УФБ – около 14 ч (70 %).

scholarly journals III. On the nature and construction of the sun and fixed stars

1795 ◽  
Vol 85 ◽  
pp. 46-72 ◽  
Keyword(s):  
Central Body ◽  
Planetary System ◽  
Considerable Progress ◽  
The Sun ◽  
Great Satisfaction ◽  
The Earth ◽  
The World ◽  
Celestial Bodies ◽  
The Universe ◽  
Made In

Among the celestial bodies the sun is certainly the first which should attract our notice. It is a fountain of light that illuminates the world! it is the cause of that heat which main­tains the productive power of nature, and makes the earth a fit habitation for man! it is the central body of the planetary system; and what renders a knowledge of its nature still more interesting to us is, that the numberless stars which compose the universe, appear, by the strictest analogy, to be similar bodies. Their innate light is so intense, that it reaches the eye of the observer from the remotest regions of space, and forcibly claims his notice. Now, if we are convinced that an inquiry into the nature and properties of the sun is highly worthy of our notice, we may also with great satisfaction reflect on the considerable progress that has already been made in our knowledge of this eminent body. It would require a long detail to enumerate all the various discoveries which have been made on this subject; I shall, therefore, content myself with giving only the most capital of them.

Study of the dynamics of the qualitative indicator of champignons during storage after treatment with UV radiation in the A range

2021 ◽  
pp. 56-57
Author(s):  
Наталья Игоревна Федянина ◽  
Ольга Вячеславовна Карастоянова ◽  
Надежда Вячеславовна Коровкина
Keyword(s):  
Mathematical Model ◽  
Radiation Dose ◽  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
Storage Capacity ◽  
Optimal Processing ◽  
Target Indicator ◽  
Processing Modes

Представлены результаты исследования влияния обработки свежих шампиньонов ультрафиолетовым излучением в диапазоне А различными дозами на изменение текстуры. Построена математическая модель зависимости предельной хранимоспособности по целевому показателю грибов от дозы облучения, и установлены оптимальные режимы обработки. The results of a study of the effect of processing fresh champignons with ultraviolet radiation in the A range with various doses on the change in texture are presented. A mathematical model of the dependence of the limiting storage capacity for the target indicator of mushrooms on the radiation dose has been built and the optimal processing modes have been established.

scholarly journals XXXIV. On the transit of Venus in 1769. To the Right Honourable The Earl of Morton, President to the Council and Fellows of the Royal Society, this discourse is, with all humility, inscribed, by their humble servant, Thomas Hornsby

1765 ◽  
Vol 55 ◽  
pp. 326-344 ◽  
Keyword(s):  
Royal Society ◽  
The Sun ◽  
The Real ◽  
The Earth ◽  
Theory Of Gravity ◽  
The Right ◽  
Made In

The observations of the late transit of Venus, though made with all possible care and accuracy, have not enabled us to determine with certainty the real quantity of the sun's parallax; since, by a comparison of the observations made in several parts of the globe, the sun's parallax is not less than 8" 1/2, nor does it seem to exceed 10". From the labours of those gentlemen, who have attempted to deduce this quantity from the theory of gravity, it should seem that the earth performs its annual revolution round the sun at a greater distance than is generally imagined: since Mr. Professor Stewart has determined the sun's parallax to be only 6', 9, and Mr. Mayer, the late celebrated Professor at Gottingen, who hath brought the lunar tables to a degree of perfection almost unexpected, is of opinion that it cannot exceed 8".

scholarly journals 160 m Pulsations in the Magnetosphere of the Earth Possibly Caused by Oscillations of the Sun

1983 ◽  
Vol 66 ◽  
pp. 451-455
Author(s):  
B.M. Vladimirsky ◽  
V.P. Bobova ◽  
N.M. Bondarenko ◽  
V.K. Veretennikova
Keyword(s):  
Uv Radiation ◽  
Wavelength Range ◽  
Optical Observations ◽  
Stable Phase ◽  
Expansion Velocity ◽  
The Sun ◽  
Flux Variation ◽  
Geophysical Observatory ◽  
The Earth ◽  
Solar Uv

AbstractThe measurements of the amplitudes envelope of Pc 3–4 geomagnetic micropulsations obtained at the Borok Geophysical Observatory were analysed by the cosinor method to search for magnetospheric pulsations with a period of about 160 m. 216 days of observations in 1974–1978 were used. It was found that Pc3–4 amplitudes are modulated by the period 160.010 m with a stable phase. The maximum of the Pc3–4 amplitudes follows approximately 20 m after the maximum of the solar expansion velocity (for the center of the disk) in the optical observations of Severny et al. This modulation of the Pc3–4 amplitudes could be caused by the presence of an oscillating component in solar UV radiation over the wavelength range 100-900 Å. The amplitude of the UV flux variation may be as large as 2–4%.

A brief illustrated history on sunscreens and sun protection

2015 ◽  
Vol 87 (9-10) ◽  
pp. 929-936 ◽  
Author(s):  
Federico Svarc
Keyword(s):  
World War I ◽  
Sun Protection ◽  
Skin Cancer Prevention ◽  
The Sun ◽  
Uvb Radiation ◽  
Human Beings ◽  
World War ◽  
Protection Factor ◽  
The Pacific ◽  
Uva Radiation

AbstractNobody exactly knows when human beings begun protecting their skin from the sun. Our dark-skinned ancestors in Africa had the benefit of natural melanin to avoid sunburn. With migration to cooler regions, humans clothed themselves to avoid frost, losing their protective pigmentation. For cultural reasons, occidentals continued to cover their body up to the XIXth century. After World War I fashion wanted tanned bodies. Oils without protection to UV radiation were used. In 1935 Eugène Schueller, founder of L’Oreal, formulated the first radiation filtering product, “Ambre Solaire Huile”. Benjamin Green produced for the soldiers battling in the Pacific a red jelly substance as a physical blocker. The hazards of sun overexposure were already apparent. The product boomed under the brand Coppertone. In 1946 Franz Greiter developed the “Gletscher Créme”. In 1956 R. Schulz introduced the concept of the sun protection factor (SPF). All those products protected only against UVB radiation, whose main visible result is erythema. There was still no concern on the more penetrating UVA radiation, and skin cancer prevention nor on several other contemporary issues. Today we benefit from very high SPF products with broad UV protection. Solubility limitations and sensorial properties make them difficult to formulate and stabilize.

scholarly journals ‘The Earth but a Satellite of the Sun’

1958 ◽  
Vol 11 (4) ◽  
pp. 409-410
Author(s):  
R. d'E. Atkinson ◽  
E. G. R. Taylor
Keyword(s):  
High Rank ◽  
The Sun ◽  
Experimental Proof ◽  
Main Thesis ◽  
The Earth ◽  
The Absolute ◽  
Made In

I Have read Professor Taylor's article with great enjoyment. There are, however, two matters of fact on which, though they do not affect her main thesis, the record should, I think, be set right, (a) The earliest experimental proof of the Earth's revolution round the Sun was neither Bessel's detection of the relative parallax of 61 Cygni, nor Henderson's determination of the absolute parallax of α Centauri (both of which occurred in 1838) but Bradley's very beautiful discovery of aberration in 1725, together with his slightly later explanation. The discovery was made in a deliberate search for parallaxes; and although that particular proof of the Earth's movement was not then achieved, it was at once recognized that aberration provided a different and equally cogent one. Bradley's work was indeed resisted, in some quarters and for a short while, for reasons which Professor Taylor will by no means find unexpected. His later discovery of one term in the nutation was also a discovery of something which would have embarrassed Ptolemy, and delighted Newton; it certainly tended to confirm the picture, if that were needed. By the time parallaxes actually were discovered, though there still were individuals, sometimes of high rank, whose prejudices were stronger than their intellects, the only point of genuine doubt was the question how far away the nearest stars really were.

A Royal Society appointment with Venus in 1769: the voyage of Cook and Banks in the Endeavour In 1768-1771 and its botanical results

1969 ◽  
Vol 24 (1) ◽  
pp. 64-90 ◽  
Keyword(s):  
Pacific Ocean ◽  
Royal Society ◽  
The Sun ◽  
Royal Navy ◽  
The Earth ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Set Up ◽  
George Iii ◽  
Made In

A little over two hundred years ago a number of serious and learned men in Copenhagen, London, Paris, St Petersbourg, Stockholm and elsewhere, men who were academicians, Fellows of the Royal Society, Lords of the Admiralty, politicians and the like, had been thinking seriously and learnedly about the behaviour of Venus, not, of course, about Venus as represented coldly and chastely by the marble statues being imported from Italy or more warmly in the paintings of Boucher and his contemporaries, but about her far distant planet which was calculated to pass across the disk of the Sun in 1769 and not to make another such transit until 1874. Observations of the 1769 transit at widely separated stations would provide, it was hoped, the means of calculating the distance of the Earth from the Sun. The Royal Society in London, having set up in November 1767 a sub-committee ‘to consider the places proper to observe the coming Transit of Venus’ and other particulars relevant to the same, presented a memorial to King George III outlining possible benefits to science and navigation from observations made in the Pacific Ocean and received in return the promise of £4000 and a suitable ship provided by the Royal Navy (8).

scholarly journals On a method of comparing the light of the Sun with that of the fixed stars

1833 ◽  
Vol 2 ◽  
pp. 355-355
Keyword(s):  
Full Moon ◽  
Angular Distance ◽  
The Other ◽  
The Sun ◽  
Proper Distance ◽  
The Earth ◽  
Direct Light ◽  
Glass Bulb ◽  
The Mean ◽  
Made In

In the Philosophical Transactions for the year 1767, a suggestion is thrown out by Mr. Michell, that a comparison between the light received from the sun and any of the fixed stars, might furnish data for estimating their relative distances; but no such direct comparison had been attempted. Dr. Wollaston was led to infer from some observations that he made in the year 1799, that the direct light of the sun is about one million times more intense than that of the full moon, and therefore very many million times greater than that of all the fixed stars taken collectively. In order to compare the light of the sun with that of a star, he took, as an intermediate object of comparison, the light of a candle reflected from a small bulb, about a quarter of an inch in diameter, filled with quicksilver, and seen, by one eye, through a lens of two inches focus, at the same time that the star or the sun’s image, placed at a proper distance, was viewed by the other eye through a telescope. The mean of various trials seemed to show that the light of Sirius is equal to that of the sun seen in a glass bulb one tenth of an inch in diameter, at the distance of 210 feet, or that they are in the proportion of one to ten thousand millions; but as nearly one half of the light is lost by reflection, the real proportion between the light from Sirius and the sun is not greater than that of one to twenty thousand millions. If the annual parallax of Sirius be half a second, corresponding to a distance of 525,481 times that of the sun from the earth, its diameter would be 3⋅7 times that of the sun, and its light 13⋅8 times as great. The distance at which the sun would require to be viewed, so that its brightness might be only equal to that of Sirius, would be 141,421 times its present distance; and if still in the ecliptic, its annual parallax in longitude would be nearly 3″; but if situated at the same angular distance from the ecliptic as Sirius is, it would have an annual parallax, in latitude, of 1″⋅8.

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