the chronobiology of the acute myocardial infarction (ami) is an interesting matter for recognition of the biological mechanism that might trigger ami. the present study was aimed to investigate the circadian, seasonal and circannual variation of the ami occurrence with solar, lunar, and christian months. a retrospective study of 1174 cases with diagnosis of ami was conducted. all cases include...

today, using new and renewable energy sources to replace fossil fuels is greatly expanded. the solar cells are devices that convert solar energy to electrical energy. solar cells based on organic materials, especially proteins, are one of these solar cells. for example, bacteriorhodopsin (br) which is one of the membrane proteins in halobacterium salinarum could be used in solar cells and parti...

This paper deals with the performance of a heat pipe solar collector. The solar collector consisted of an interconnected heat pipe so as to reduce the production cost by using an interconnected heat pipe because all the heat pipes can be evacuated, sealed and tested at once. Performance of a prototype of the heat pipe solar collector was experimentally examined, and the results were compared wi...

the main problemswith the use of fossil fuels is the restrictions on their access and the detrimental consequences of their use which causes a threat to human health and quality of life. consequently, the use of other energy sources has become necessary. renewable energy as a permanent and clean energy source is an answer to this problem. one such energy source includes photovoltaic solar energ...

this paper presents mathematical models of thin layer forced convection solar drying of cuminum cyminum using two drying methods (mixed and indirect) at different operating conditions. the average initial moisture content of the seeds for all tests was about 43% d.b. and the drying was performed continuously, in each test, for a uniform period of 90 minutes drying time in a solar cabinet dryer ...

new selective coating materials are developed and used in advanced solar collector and absorber designs with improved efficiency. cobalt and copper sulfides nanoparticles are high interest for absorbers of solar thermal collectors due to their optical properties and high absorptance in the solar wavelength range (> 96%). in the present work, cobalt and copper sulfides nanoparticles were synthes...

virial theorem is important for understanding stellar structures. it produces an interesting connection between magnetic and gravitational energies. using the general form of the virial theorem including the magnetic field (toroidal magnetic field), we may explain the solar dynamo model in relation to variations of the magnetic and gravitational energies. we emphasize the role of the gravitatio...

in the present work the effect of cu-water nanofluid, as heat transfer fluid, on the performance of a parabolic solar collector was studied numerically. the temperature field, thermal efficiency, mean-outlet temperatures have been evaluated and compared for the conventional parabolic collectors and nanofluid based collectors. further, the effect of various parameters such as fluid velocity, vol...

Considering that the effective yield of a panel is equal to its total number of hours of solar radiation and temperature, only the effects of temperature and solar radiation intensity at the maximum power point (MPP) are investigated in this article. By collecting temperature data, sun's radiation hours from six synoptic meteorological stations in Kermanshah Province over the course of an e...