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The use of renewable energy sources has increased exponentially worldwide. Cuba has implemented a program until 2030 where renewable sources play a fundamental role within the national energy matrix. The policy regarding the installation of solar plants has been to connect small plants of up to 5 MW, mainly in distribution networks. In this work an optimization algorithm is developed to identify the best connection points of small solar plants in distribution networks. The algorithm solves the problem through a power flow combined with a full N-P allocation model. The goal of the algorithm is obtaining the best points to connect solar plants in buses of a radial distribution network at to minimize total active power losses or the deviation of voltage profile. [ABSTRACT FROM AUTHOR]

The bacterias constitute the second group in importance like pathogens of plants. The genus of more importance are Clavibacter, Agrobacterium, Pectobacterium, Pseudomonas and Xanthomonas. The bee-glue has demonstrated microbial action bacterias. The present work had as objectives: to evaluate "in vitro" three concentrations of two extracts of bee-glue of different origin in the inhibition of growth of Pectobacterium carotovorum subsp. atroseptica, Xanthomonas vesicatoria, Clavibacter michiganensis subsp. michiganensis (Cmm), Agrobacterium tumefaciens, Ralstonia solanacearum, Pseudomonas syringae pv. tomato, Pseudomonas corrugata, Xanthomonas campestris pv. cucurbitae, Pseudomonas sevastanoi subsp. sevastanoi, Xanthomonas axonopodis pv. citri and to determine the Inhibitory Minimum Concentration (IMC) and the effect germicide of 15 isolations of Cmm. The microbial activity of bee-glues extracts was carried out by means of the antibiogram technique. IMC of bee-glue extracts was determined in front of isolations of C. michiganensis michiganensis. The extracts of bee-glue of the two origins inhibited the growth of C. m. michiganensis in all the evaluated concentrations. The extract of Cannelonis produced bigger inhibition diameter that that of Rocha. This inhibition difference is also observed in the dose of 120 mg/mL for X. campestris pv. cucurbitae and X. vesicatoria. The bacteria R. solanacearum was inhibited in the concentrations 120 and 80 mg/mL of the bee-glue of Cannelonis and 120 mg/mL of bee-glue of Rocha. None of the extracts inhibited the growth of Pectobacterium carotovorum atroseptica, A. tumefaciens, P. s. pv. tomato, P. corrugata, P. s. pv. sevastanoi, X. to. pv. citri, the same as the control. [ABSTRACT FROM AUTHOR]

A sampling plan was designed, starting from the results about the distribution in plant and field of T. palmi potato crop. For this, two sampling proceedings were considered in productive areas of Havana province during three years. They consisted on evaluating larvae density in parcels or in the diagonal of the sector. Mean density was valued by means of variance analysis and means were compared by Duncan (p< 0.05). Relative variation , net relative precision and the most adequate sample size were also calculated. The results showed that, starting from means superior to 3.01 larvae/ folioles, the best procedure is in diagonal, while at lower values, the best estimation was achieved in parcels. In this case the sample required approached at 100 folioles. In a way that population increases 50 and 64 folioles, a reliable sample size can be obtained. [ABSTRACT FROM AUTHOR]