the numerical investigation of computing the rate of radiated solar-energy requires equations as a function of solar-time according to the radiation angle of the sun (β) in the latitude 37°n and the shape. this paper implements the lagrange interpolation to obtain the equations of normal diagram of elements based on data obtained from surveying. also the method of hann-window equation used to e...

consideration of the current-voltage (i-v) characteristics variations of solar modules with temperature and irradiations variations is basic for maximum power point tracking (mppt). having a simple and accurate mathematical model for the optimize utilization of the solar modules is essential. in this paper, a novel modeling of photovoltaic systems with novel coefficients is proposed for mathema...

sustainable development would be a key solution for climate change and renewable energy plays an important role in this policy. recently, according to increase of co2 emission and other relevant impacts, solar energy has been gaining more attentions from policy makers. thus, compound parabolic concentrators collectors are considered as one of the promising applications from solar thermal advant...

in recent years immense interest has been focused on the use of solar dryers especially when taking into consideration economical and ecological aspects and increasing in fuel costs. the aim of this study was to compare the qualitative factors of raisins made by five different drying methods. at the first step, pretreatments were applied to grapes (var. sultanas) and then the grapes were dried ...

monitoring the effective parameters of drying crops is necessary to evaluate and determine system performance under real conditions. hence, a monitoring system was constructed to determine the performance of a vegetation forced-convection solar dryer. digital temperature sensors were set up in the air inlet and outlet of the collector and the air outlet of the drying chamber. a program was writ...

the paper deals with the analysis of the external factor (solar activity, volcanic eruptions) influence on tree growth at the kola peninsula, northwestern russia. pinus sylvestris l. (scots pine) tree-ring chronologies collected nearby the northern timberline (68.63n, 33.25e) include the oldest (1445-2005 ad) living pine tree found up to date in the kola peninsula. a total of 18 living trees p...

outdoor experiments on a once-through single glazed solar air heater with perforated metal absorber plate were conducted to determine the practical effect of absorber plate porosity as well as suction air flow rate on the collector thermal efficiency and its total pressure drop. three aluminum absorber plates were made perforated by drilling circular holes with different diameter/pitch ratios i...

We investigated geomagnetic activity which was induced by interplanetary magnetic clouds during the past four solar cycles, 1965–1998. We have found that the intensity of such geomagnetic storms is more severe in solar maximum than in solar minimum. In addition, we affirm that the average solar wind speed of magnetic clouds is faster in solar maximum than in solar minimum. In this study, we fin...

Today, due to qualitative growth and scientific advances, energy, especially electricity is increasingly needed by human society. One of the almost endless and pure energy which have been paid attention over the years is the solar energy. Solar cells directly convert solar energy into electrical energy and are one of the main blocks of photovoltaic systems. Significant improvement has been made...