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We have derived the velocities of meridional flows by measuring the latitudinal motions (or drifts) of umbrae of spot groups classified into three categories of area: 0 -5 μ, 5 -10 μ, and >10 μ (μ area in millionths of the solar hemisphere). The latitudinal drifts (or the meridional flows) in all three categories are directed equatorward in both the northern and southern hemispheres. By sorting the spot groups into three area classes, we are able to relate the respective latitudinal drifts with the three depths in the convection zone where the footpoints of the flux loops of the spot groups of each area class are anchored. We obtain estimates of the anchor depths through a comparison of the rotation rates of the spot groups of each area class with the rotation-rate profiles from helioseismic inversions. The equatorward drifts obtained provide estimates of the meridional flows at the three depths in the convection zone and thereby suggest the presence of return meridional flows as envisaged in the flux-transport dynamo models, which have remained undetected so far. The data sources for this study are measurements of positions and areas of umbrae of sunspots from the photographic white-light images of the Sun of the Kodaikanal Observatory archives for the period 1906 -1987 and a very similar, but independent, data set from the Mt. Wilson Observatory archives for the period 1917 -1985.

A model has been established based on numerical calculation to analyze a vertical tube in tube stainless steel generator with forced convective boiling. Refrigerant vapour is generated from the weak refrigerant-absorbent solution takes place in the middle tube of the generator, when hot water through the outer side is used as boiling medium and the pipe arrays inserted is the phase change material containment. This paper shows the results of the TRNSYS modeling and simulation of a solar absorption cooling system under the weather conditions of Chennai in order to partially satisfy the thermal demand of a building room. The maximum hourly thermal load reaches 165 kW. The suggested model operates with concentrating parabolic collectors, a NH3-H2O single effect absorption air-conditioning system, hot water storage with PCM and an external auxiliary boiler. As a result of the method simplifying for the varying climate and different orientation of the components are analyzed. These outcomes show that the prime system could succeed a yearly solar fraction of 0.58.

Abstract.We have derived the latitude motions of sunspots classified into three area categories using the measures of positions and areas of their umbrae from the white -light images of the Sun for the period 1906 -1987 from the Kodaikanal Observatory archives. The latitude motions are directed equator -ward in all the three area classes. We interpret that these equatorward latitude motions reflect the meridional flows at the three depths in the convection zone where the magnetic flux loops of the spots of the three area classes are anchored. We obtain estimates of the anchor depths through a comparison of the rotation rates of the spots in each area class with the rotation rate profiles from helioseismic inversions. The equator -ward flows measured by us thus provide evidence of the return meridional flows in the convection zone as required in the flux transport solar dynamo models. We have done an identical analysis using a similar data set derived from the photoheliogram collections of the Mt.Wilson Observatory for the period 1917 -1985. There is good agreement between the results from the data sets of the two observatories.

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