• Energy Research

AbstractIn this work, the design, construction and instantaneous efficiency in solar water heater were investigated. A thermal analysis was developed, based on the energy balanced in the solar collector. The geometry and dimension in the collector was determinate by the results of the thermal analysis and the thermal properties of the materials used for the collector construction. The dimension of solar collector was of 1.4 m2 with a storage tank of 100 L. The highest temperature reached was 55.0 oC and decreased to 47.6 oC during the night. The flow rate was at range from 0.0038-0.04kg/s, and the global average efficiency was of 30.2%.

AbstractEarthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.

AbstractIn this work a detailed study of Savonius wind rotor was investigated in order to obtain the optimal characteristics. The designed Savonius wind rotor assembly was developed on CAD software. Simulations of the interaction between the flow of air and blades were developed through finite element analysis. A result of these simulations shows the velocity distribution of the profile blades. In the same way, it was obtained the profile pressure due the velocities profiles. The formations of vortices were studied with the finality to improve the performance of the Savonius rotor. Blades with different geometry and gap distance between the blades were simulated, the results shown better geometry for the blade and gap distance between blades that improved the power coefficient (Cp) of the Savonius rotor. Simulations results show that the geometry and gap distance of the blades increases the Cp about 20%. Through gap distance between the blades, the wind was directed to the surface of following blade to induce its rotation. An air deflector was located front the Savonius rotor to increase and guide the flow of air to the blades. The deflector increased the velocity of the Savonius rotor up to 32%. From the simulation results it was built a prototype Savonius wind rotor at scale 2:1 according to simulation done; field tests will be performed to check the amount of energy obtained with the changes implemented.