Reconfiguração ótima de sistemas de distribuição para minimização de perdas de energia

This paper presents an algorithm for reconfiguration of Electrical Distribution Systems in order to minimize energy losses considering different load levels. This problem is considered as mixed integer non linear programming, in which a continuous function is used to handle the discrete variables. As consequence, the proposed model is solved using a step by step approach where the primal-dual interior point technique is solved at each step. The Lagrange multiplies are used to evaluate the sensitivity index for the reconfiguration process. The developed algorithm is tested in three systems of the literature.Este artigo apresenta um algoritmo para a reconfiguração ótima de Sistemas de Distribuição de Energia Elétrica (SDE), com o objetivo de minimizar a perda total de energia considerando diferentes níveis de carregamento. Trata-se de um problema de programação não linear inteira mista onde a variável discreta é modelada como uma função contínua. Como conseqüência, o problema proposto é resolvido através de um algoritmo passo a passo, onde em cada passo é utilizado o Método Primal-Dual de Pontos Interiores. Os multiplicadores de Lagrange são utilizados para compor o índice de sensibilidade no processo de reconfiguração. O algoritmo proposto é testado em três sistemas encontrados na literatura

Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid

Alves C. J., Alcino J. F., Farias A. E. M., Higino S. S. S., Santos F. A., Azevedo S. S., Costa D. F. & Santos C. S. A. B. 2012. [Epidemiological characterization and risk factors associated with leptospirosis in the brazilian semiarid.] Caracterizacao epidemiologica e fatores de risco associados a leptospirose em ovinos deslanados do semiarido brasileiro. Pesquisa Veterinaria Brasileira 32(6): 523-528. Universidade Federal de Campina Grande, Centro de Sa de e Tecnologia Rural, Unidade Academica de Medicina Veterinaria, Av. Universitaria s/n(o), Patos, PB 58700-970, Brazil. E-mail: [email protected] The aim of this investigation was to determine the herd-level and animal-level prevalence of leptospirosis in sheep from the semiarid of Paraiba State, Northeast Brazil, as well as to identify risk factors. Blood samples were collected from 1,275 sheep from 117 flocks in 19 counties in the Sertao mesoregion, Paraiba. For the serological diagnosis of leptospirosis the microscopic agglutination test (MAT) using 24 Leptospira spp. serovars as antigens was carried out. Of the 117 flocks studied 33 (28.20%) presented at least one seropositive sheep, and of the 1,275 animals 69 (5.41%) were seropositive with titers ranging from 100 to 3,200. Reactant serovars were Autumnalis (49.30%), Andamana (27.53%), Sentot (17.39%), Whitcomb (4.34%) and Australis (1.44%). Herd size > 48 sheep (odds ratio = 2.26; 95% CI = 1.33-5.07; p = 0.021) and participation in animal exhibits (odds ratio = 9.05; 95% CI = 0.96-85.71; p = 0.055) were identified as risk factors. The need was suggested for studies on the isolation of the agent, characterization of its pathogenicity and its economic impact on sheep flocks of the region, and sanitary control in sheep agglomerations was recommended

Cold Brewing Process to Produce Light Beer

Looking for new beer production techniques, the cold extraction process showed as an alternative, which is very common in producing beverages such as coffee but needs better scientific information for application in the manufacture of beer. This technique is known as Cold Brew, which aims to extract compounds through a cold solvent, in this case, water. This work aims to prepare a beer using the Cold Brew technique to remove a smaller amount of starch, thus generating a beer with a proportionally reduced final alcohol content, obtaining a body that is made classically. For the study, three treatments were made. They consisted of a standard beer as a Control (C), a cold brew (CB), and a diluted beer (DB) with the original Extract coincident with the cold brew. The physicochemical analysis, sugar quantification by HPLC, and sensorial analysis were made to evaluate the three treatments. The curves obtained for rhamnose, fructose, and sucrose showed no significant difference between C and CB but differed from DB. The C presented an average alcohol content of 5.1 + 0.07%, while the CB and DB presented 1.60 + 0.05 and 1.53 + 0.05%, respectively. Furthermore, a sensory analysis showed that the acceptance of SB and CB beers was higher than DB. Reductions in CB were obtained in; alcohol, Density, Extract, and calories compared to SB, but they meet the expectations for a beer with such a low content of fermentable sugars. This method showed potential for the manufacture of light cherries with low alcohol content, corroborating the fact that it is not a diluted beer but an alternative method for the elaboration of different styles of new beers

Retinofugal Projections Into Visual Brain Structures in the Bat Artibeus planirostris: A CTb Study

A well-developed visual system can provide significant sensory information to guide motor behavior, especially in fruit-eating bats, which usually use echolocation to navigate at high speed through cluttered environments during foraging. Relatively few studies have been performed to elucidate the organization of the visual system in bats. The present work provides an extensive morphological description of the retinal projections in the subcortical visual nuclei in the flat-faced fruit-eating bat (Artibeus planirostris) using anterograde transport of the eye-injected cholera toxin B subunit (CTb), followed by morphometrical and stereological analyses. Regarding the cytoarchitecture, the dorsal lateral geniculate nucleus (dLGN) was homogeneous, with no evident lamination. However, the retinal projection contained two layers that had significantly different marking intensities and a massive contralateral input. The superior colliculus (SC) was identified as a laminar structure composed of seven layers, and the retinal input was only observed on the contralateral side, targeting two most superficial layers. The medial pretectal nucleus (MPT), olivary pretectal nucleus (OPT), anterior pretectal nucleus (APT), posterior pretectal nucleus (PPT) and nucleus of the optic tract (NOT) were comprised the pretectal nuclear complex (PNT). Only the APT lacked a retinal input, which was predominantly contralateral in all other nuclei. Our results showed the morphometrical and stereological features of a bat species for the first time

Commentaries on viewpoint : physiology and fast marathons

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Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio