Recently, the longitudinal oscillations of intensity have been frequently detected in the different structures of the Solar corona using space telescope observations. Some researchers believe that the magneto-acoustic waves, which share the plasma heating processes in the corona, are responsible for the longitudinal oscillations of the intensities. In this study, the aim is to discover the location, generation, propagation and damping of the magneto-acoustic waves in the corona structures as well as to compare the results with theoretical models. For this purpose, for each selected active region, about 400 sequence images are taken at 12 seconds intervals at 171 angstroms using AIA instrument onboard on the SDO space telescope. For each set, the histogram equalization is applied with respect to the first image for all images, then the time series of intensities are extracted from the successive macropixels with 3  3 pixels wide on different paths along the active region loops. Different filters are applied to the time series of the intensities, and real and stable frequencies are identified from the unrealistic and unstable frequencies of the noise in the spectral power density using the Lamb-Scargle algorithm. The physical quantities of the dominant frequencies are computed. The results of this analysis showed that magneto-acoustic waves are produced at the base of the loops of the active regions and propagated along the loops. The range of oscillation period, apparent velocity, apparent length, damping time, and damping quality of these extracted waves are 7 􀀀 32 minutes, 66 􀀀 363 km=s; 8 􀀀 103 mega meters, 0: 7 􀀀 12 minutes and 0: 06 􀀀 0: 63, respectively. Also, by comparing the observational results with the theoretical models, the temperature range and electron numerical density of the selected regions are estimated.

An experiment to search for short-period intensity oscillations in the Solar corona was conducted during the total Solar eclipse of August 11, 1999 in Esfahan, [ran. The intensity in the continuum, centered about 4700Å and with a passband having a half-width of 190 Å, was recorded at a counting rate of 5 Hz using six low-noise Hamamatsu R647 photomultiplier tubes. We recorded intensity values from 6 different regions on the image of the Solar corona from 1.2 R to 1.5 R. The power spectrum analysis of all channels, except for a channel that failed to receive any coronal light, shows excess power in the frequency range 0.02-0.2 Hz. The results of analyzing all channels demonstrate various waves with some degree of coherence and amplitudes from 0.3 to 0.7 percent of the mean coronal brightness. There are some similarities between waves in various channels and it may show that these waves exist in a large region of the corona, of the order of a few hundred thousand kilometers, much larger than the fiber optic diaphragms. The energy flux of each wave was calculated by assuming them as the slow or fast mode waves for the active and quiet regions of the Solar corona. The energy flux of the fast mode waves in the active regions is comparable with the required energy flux for heating up the Solar corona. The intensity oscillations observed in this experiment are similar to those detected during the 1995 and 1997 eclipses.

Background: Solar ultraviolet radiation (UVR) is considered one of the most important biological risk factors in the world. Most health damages from Solar ultraviolet radiation at ground level are mainly caused by UVA and UVB spectrums.Objective: The aim of this study was to Measure the Solar ultraviolet radiation intensity type A and B in Qazvin city.Methods: In this cross-sectional study, the intensity of Solar ultraviolet radiation type A and B was measured in Qazvin on years of 2013-14 (during one year) every monthly at three times, in the morning, afternoon and evening by using a UV Radiometer. Data were analyzed using descriptive statistics.Findings: The maximum average intensity of UVA and UVB rays during the one year with 28.36±1.88 W/m2 and 0.156±0.035 W/m2 respectively was in Tir month (June 22–July 22) and the minimum average intensity of UVA and UVB rays with 10.36±0.83 W/m2 and 0.041±0.010 W/m2 respectively was in Dai month (December 22–January 20).Conclusion: With regards to the results, it is recommended that individuals were less exposed to exposure time with direct sunshine and use appropriate protective measures such as; wear appropriate clothing, sunglasses, and sunscreen.

Dyes belong to organic compound families with complex structure due to their toxicity, carcinogenic and lack of biodegradability properties' are considered as a serious environmental pollutant. The objective of this paper is to investigate decolorization of Reactive Blue 19 from contaminated water by potassium peroxydisulfate and Solar light in the presence of Solar parabolic concentrator. Solar irradiation intensity will be increased. In this case radiation after reflecting will be concentrated on the focal path of collector. The more light intensity, the more enhancement production of sulfate radical from persulfate would be. In this study evaluation of effective parameter has been investigated. Regards to the results from homogenous photo-oxidation in presence of Solar concentrator has been introduced and considered as a superior option for removal of dyes from textile' industry wastewater. Using this collector dramatically increase the performance of advanced oxidation processes respects 98% of RB19 has been mineralized during 60 min in optimal condition.

Solar radiation reaching the earth's surface is one of the most important variables used in Solar energy projects, hydrological modeling, evaporation and transpiration, meteorology and agriculture. In this research, the functionality of principal component analysis and linear multivariate regression was investigated in predicting the amount of Solar radiation in Yazd station between 2010 to 2014 and 2015 to 2021. Variables of average temperature, minimum temperature, maximum temperature, hours of sunshine, relative humidity and Solar radiation are received from the Meteorological Organization on a daily basis and variables of extraterrestrial Solar radiation, relative distance from the earth to the sun, Solar inclination angle and maximum hours of sunshine are calculated with the existing relations and was chosen as input of Principal component analysis method. The correlation of these parameters with the amount of Solar radiation shows the presence of a significant positive relationship at the level of 1% between the amount of Solar radiation and extraterrestrial radiation, the ratio of sunny hours, the average temperature and the relative distance from the earth to the sun, and with the Solar inclination angle at the level of 5% and was observed a significant negative correlation at the level of 1% with relative humidity values. The results of the analysis of the main components showed that the first two components can be selected as the main components according to the eigenvalues of the parameters and the percentage of variance. The correlation coefficient of the first and second components with Solar radiation was 0.893 and -0.168, respectively, and as a result, the first component has a higher correlation with the amount of Solar radiation than the second component. The rotated value of loading in the first component shows that the minimum temperature, maximum temperature, average temperature and relative humidity are more correlated with Solar radiation and the correlation of other factors (extraterrestrial radiation, Solar inclination angle and relative distance from the earth to the sun and the ratio of sunny hours) is low in this component. Investigating the relationship between Solar radiation and the values of the main components obtained from PC1 and PC2 using multivariate linear regression showed that the effect of meteorological parameters on Solar radiation is significant (p < 0.001) and its R2 is was determined as 0.89%. The evaluation criteria of PCR and MLR methods show the ability of PCA method to estimate Solar radiation.

We are exposed to ultraviolet (UV) light every day. Depending on its wavelength, UV light has various biological effects. The waveband 315 to 400 nm is referred to "UV-A." UV-A causes several adverse effects on human including decreased immunity, flakiness, skin blister, erythematosus, and skin cancer...

This paper aims to produce freshwater from saline water with the help of Solar still. Different Solar wick materials still absorb the sunlight and convert the heat energy, such as black sheer mesh fabric, light black cotton fabric, light jute fabric, black velvet fabric, and 4 mm thick sponge sheet. The wick materials sheets were wholly immersed in the saline water covering the total still basin area. The net basin horizontal active area of the Solar still is 0. 48 m² , and the glass cover’ s tilted angle was fixed at 36º . From this arrangement, it has been found that by the use of various wick materials, the productivity rate differs from each other, and among these wick materials, light black cotton is the most effective wick material for Solar still productivity increment. The pH value measures the final quality of the freshwater.