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Wireless, battery-free, flexible, miniaturized dosimeters monitor exposure to solar radiation and to light for phototherapy
摘要： Exposure to electromagnetic radiation can have a profound impact on human health. Ultraviolet (UV) radiation from the sun causes skin cancer. Blue light affects the body’s circadian melatonin rhythm. At the same time, electromagnetic radiation in controlled quantities has beneficial use. UV light treats various inflammatory skin conditions, and blue light phototherapy is the standard of care for neonatal jaundice. Although quantitative measurements of exposure in these contexts are important, current systems have limited applicability outside of laboratories because of an unfavorable set of factors in bulk, weight, cost, and accuracy. We present optical metrology approaches, optoelectronic designs, and wireless modes of operation that serve as the basis for miniature, low-cost, and battery-free devices for precise dosimetry at multiple wavelengths. These platforms use a system on a chip with near-field communication functionality, a radio frequency antenna, photodiodes, supercapacitors, and a transistor to exploit a continuous accumulation mechanism for measurement. Experimental and computational studies of the individual components, the collective systems, and the performance parameters highlight the operating principles and design considerations. Evaluations on human participants monitored solar UV exposure during outdoor activities, captured instantaneous and cumulative exposure during blue light phototherapy in neonatal intensive care units, and tracked light illumination for seasonal affective disorder phototherapy. Versatile applications of this dosimetry platform provide means for consumers and medical providers to modulate light exposure across the electromagnetic spectrum in a way that can both reduce risks in the context of excessive exposure and optimize benefits in the context of phototherapy.
关键词： miniaturized dosimeters,phototherapy,UV,flexible,NFC,battery-free,solar radiation,blue light,wireless,photodiodes
更新于2025-09-09 09:28:46
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A dynamic model for solar radiation in the Tyrrhenian Basin of Central Mediterranean area
摘要： Studying the level of solar radiation is important for problems related to both environmental pollution and alternative energy development. In this work a space-time model for solar radiation in the Tyrrhenian basin is presented. Three main features of the model must be stressed because of their importance in modelling space-time variability of a phenomenon. The first and most important one is that relations between solar radiation in different sites are an outcome of the model’s estimation procedure. With this approach spatial weights are not bound to be symmetrical and proportional to distance between locations or to be constant over time. The second one is the presence of a simultaneous effect among locations as the solar radiation in one of them is a function of what simultaneously happens in all the other ones. The third main feature of the model is represented by constrained estimation on the basis of a priori knowledge about the phenomenon that allows to cope the problem of the increased number of parameters.
关键词： solar radiation,constrained maximum likelihood estimator.,simultaneous effect,space-time models
更新于2025-09-09 09:28:46
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Estimating Daily Solar Radiation from Monthly Values Over Selected Nigeria Stations for Solar Energy Utilization
摘要： The solar radiation needed for effective research into solar energy utilization can be determined using concise and reliable data which can be gotten from hourly or daily data. The parameters which govern a physical model of the sky should be taken hourly or daily. The values which fluctuate according to the fluctuating changes in the meteorological and environmental situations should be analyzed with data over a short period of time. These parameters include the sunshine hours, Solar radiation, cloud cover, temperature etc. In predicting the performance of solar energy conversion devices, a sequence of daily radiation is always required. The daily data are not readily available, hence, there is need for the derivation of the needed, which is the daily solar radiation data from the available- the monthly averages. For many stations in Nigeria, only monthly long-term averages are available and the problem of extracting reliable information always sets in. Therefore, this paper proffers solutions to this by establishing a procedure for the derivation of daily solar radiation from the monthly averages using Fourier series.
关键词： Solar radiation,Daily data,Month averages,Fourier series
更新于2025-09-09 09:28:46
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Effect of Different Solar Radiation Data Sources on the Variation of Techno-Economic Feasibility of PV Power System
摘要： The aim of this study is to evaluate the variation in techno-economic feasibility of PV power system under different data sources of solar radiation. HOMER simulation tool is used to predict the techno-economic feasibility parameters of PV power system in Baghdad city, Iraq located at (33.3128° N, 44.3615° E) as a case study. Four data sources of solar radiation, different annual capacity shortages percentage (0, 2.5, 5, and 7.5), and wide range of daily load profile (10-100 kWh/day) are implemented. The analyzed parameters of the techno-economic feasibility are COE ($/kWh), PV array power capacity (kW), PV electrical production (kWh/year), No. of batteries and battery lifetime (year). The main results of the study revealed the followings: (1) solar radiation from different data sources caused observed to significant variation in the values of the techno-economic feasibility parameters; therefore, careful attention must be paid to ensure the use of an accurate solar input data; (2) Average solar radiation from different data sources can be recommended as a reasonable input data; (3) it is observed that as the size and of PV power system increases, the effect of different data sources of solar radiation increases and causes significant variation in the values of the techno-economic feasibility parameters.
关键词： effect of solar radiation from different climate databases,climate databases available online,variation of techno-economic feasibility parameters,PV power systems
更新于2025-09-09 09:28:46
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A Climatology of Solar Irradiance and its Controls across the United States: Implications for Solar Panel Orientation
摘要： The National Solar Radiation Database (NSRDB), which is a spatially-dense modeled dataset intended to accurately represent long-term statistics, was used to construct a 15-year climatology of variations in the direct-beam and diffuse radiation fields across the United States (US). Continental scale variations in the radiation field vary predominantly by latitude during the winter and longitude during the summer. Eight sub-regions, defined by similar climate forcing and geography, demonstrate that the largest seasonal and year-to-year variations in the diffuse-to-direct ratio are in the Northwest and Southwest, while the smallest are in the Northeast and Southeast. The year-to-year variability across the western US is attributed to large scale climate signals, such as the El Ni?o Southern Oscillation (ENSO). A preponderance of diffuse radiation during the summer in the Midwest, South-Central, Southeast and Northeast is demonstrated. It is suggested that harvesting procedures be tuned to accommodate this preponderance. Orienting a fraction of fixed panels to optimize the diffuse beam during the summer in these regions is suggested to increase energy yield. Adopting a seasonal and year-to-year approach in the harvesting procedure in the Northwest and Southwest that is tuned to large scale climate signals is likely to optimize harvest yield in those regions.
关键词： diffuse radiation,panel orientation,US radiation climatology,Solar radiation,clouds,solar panel
更新于2025-09-04 15:30:14
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Relación de la Transmitancia Atmosférica con la Heliofanía y la Diferencia de Temperaturas Extremas Diarias en la Zona Ecuatorial Andina
摘要： In this work, values of atmospheric transmittance coefficients using heliophany (sunshine hours) and the difference between maximum and minimum temperatures are proposed for a city located in the Andean Ecuadorian zone. First, the extraterrestrial radiation was calculated to study the reliability of the models. Later, statistical techniques were applied to meteorological data measured since June 2007 for a period of almost five years. These data were used to calculate the empirical lineal coefficients between different variables, using three models: one using heliophany and two using the difference between temperatures. The results showed that there is a more consistence relation between solar radiation and sunshine hours. In addition, it was established that it is not adequate to generalize the results to other locations even if they have similar weather characteristics.
关键词： solar radiation,atmospheric transmittance,Andean Ecuador,extraterrestrial solar radiation
更新于2025-09-04 15:30:14
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Total Global Solar Radiation Estimation with Relative Humidity and Air Temperature Extremes in Ireland and Holland
摘要： Solar radiation is the earth’s primary energy source for all biochemical and physical activities. Accurate knowledge of the solar radiation is important in engineering applications. This study aimed to calibrate some of the existing models in the literature for estimating daily total global solar radiation parameter using available measuring records (maximum and minimum air temperatures) and new models were developed based on maximum and minimum air temperatures, relative humidity and relative humidity extremes. Applicability of the Hargreaves model, Allen model, Bristow-Campbell model and Chen model were evaluated for computing the daily total solar global radiation, the geographical and meteorological data of Irish and Dutch cities were used. Meteorological data were taken from Royal Netherlands Meteorological Institute and Irish Meteorological Service. The models were compared on the basis of error tests which were mean percentage error (MPE), mean bias error (MBE), root mean square error (RMSE) and Nash-Sutcliffe equation (NSE). And, monthly MPE errors were given for each model. This study proposed new estimation models which were based on daily average relative humidity, relative humidity extremes and temperature extremes. Error analyses were applied to these models and results were given in the study.
关键词： Holland,solar radiation,model validation,temperature,daily total global solar radiation,relative humidity,model comparison,Ireland,meteorological models
更新于2025-09-04 15:30:14
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Evaluation of the Level of Transmission of Solar Radiation by Eyeglasses (Spectacles) and its Effects on the Human Eye
摘要： Global atmospheric changes such as depletion of Ozone in the stratosphere and global warming contribute to the average increase of ultraviolet radiation on earth. Protective eyeglasses are normally recommended to safeguard the eyes from the harmful effects of solar radiation. In this paper, twenty (20) pairs of eyeglasses were selected based on systematic random sampling to determine the amount of optical radiation transmission and level of attenuation by eyeglasses, in the wavelength range of 200nm to 900nm using 6405 UV/VIS spectrophotometer. All the eyeglasses were found to transmit a substantial amount of ultraviolet radiation. The transmission of visible light depends on the lens colours. It was discovered that the eyeglasses do not provide complete protection from UV radiation. This shows that the glasses can still pose great danger to human eyes.
关键词： Spectrophotometer,Eyeglasses,Human eye,Percentage transmittance (%T),Optical radiation,Global warming,Depletion of Ozone,Solar radiation,Attenuation
更新于2025-09-04 15:30:14
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Estimation and validation of daily global solar radiation by day of the year-based models for different climates in China
摘要： Day of the year-based (DYB) models can achieve great accuracy in daily global solar radiation estimation without specific meteorological elements. Many empirical models (EMs) and machine learning (ML) methods have been proposed for DYB models. However, the number of their comparative studies based on diverse climates is limited. In this study, a grand total of 14 DYB models are established to estimate daily global solar radiation based on measured data from 1994 to 2015 at 35 meteorological stations in six climate zones of China. Detailed tasks are as follows: (1) Seven EMs and seven ML models are trained for solar radiation estimation. (2) A new EM and two novel ML models are proposed, i.e. hybrid 3th order polynomial and sine wave model, adaptive neuro-fuzzy inference system (ANFIS) optimized by chaotic firefly algorithm (CFA) and ANFIS optimized by whale optimization algorithm with simulated annealing and roulette wheel selection (WOASAR). (3) Four statistical indicators are utilized to compare those models, and the best model for each station is decided. (4) We discuss the model parameters and climate variances of six specific stations in different climate zones. The comparison results demonstrate superb estimation precision and climate adaptability of the newly proposed models.
关键词： Day of the year,Empirical models,Global solar radiation estimation,Machine learning
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Emerging Trends and Innovations In Engineering And Technological Research (ICETIETR) - Ernakulam, Cochin, India (2018.7.11-2018.7.13)] 2018 International Conference on Emerging Trends and Innovations In Engineering And Technological Research (ICETIETR) - Statistical Analysis of Monthly Solar Radiations and Wind Speed Data
摘要： Increase in electricity demand has motivated us to move towards renewable energy sources. These energy sources are available abundantly and can never be exhausted. Environmental impacts are much lower than those with conventional energy sources. Therefore, in this study, solar and wind data has been collected at Aurangabad, Maharashtra (Latitude: 19o52’ 3.61” N – Longitude: 75o19’ 23.99” E) for a period of one year and statistical analysis has been carried out. Solar radiation data has been recorded to estimate the level of radiations falling on the same location mentioned above, while the wind speed data has been recorded and analyzed using Weibull and Rayleigh distribution and the best fitting distribution of wind has been found out using goodness of fit tests.
关键词： Weibull,Rayleigh,goodness of fit tests,Chi-Squared test,root mean square error,monthly solar radiation,wind speed,probability density function
更新于2025-09-04 15:30:14