NEWSLETTER 17

Annals of the Brazilian Academy of Sciences

AABC - Volume 88 (4) - December 2016

I am very pleased to introduce the last issue of the AABC of 2016! This year we have published 200 papers (+5 editorials) in six issues - a record for the journal.

As usual, it is very hard to select the most interesting contributions among the 33 papers published here, that cover a variety of fields, from Mathematical to Health Sciences. Earth Sciences are leading this issue with 8 manuscripts discussing topics like seasonal variation and the hydro-biogeochemical features of two upland lakes; new aspects of volcanic rocks from the Paraná volcanic province; and new dates from the Devil´s Cave using thermoluminescent techniques. I would also call your attention to a discussion on paleo-sea level changes on the coast of Rio de Janeiro - lots of arguments here.

In the field of Chemical Sciences, I would like to highlight a study on barium as an indicator of paleoproductivity. In Health Sciences, there is a contribution that presents new ways to treat fungal infection of skin and a paper addressing the obesity in children.

Please, keep in mind that since 2000 all papers published by the AABC can be downloaded free of charge at the SciELO site and previous editions of the Newsletter are available at the ABC website.

We are now inviting you to scroll through the text and click on the title of the article that interests you!

Alexander W. A. Kellner
Editor-in-Chief

MATHEMATICAL SCIENCES

1-On simple Shamsuddin derivations in two variables
Author: Rene Baltazar

In these notes, we prove a conjecture about the finitude of the isotropy for a family of derivations and to understand the isotropy of a simple derivation of k[x,y], we give necessary conditions for an automorphism to belong to the isotropy of a simple derivation.

Read here

2-Translation Hypersurfaces with Constant S_r Curvature in the Euclidean Space
Authors: Barnabé P. Lima, Newton L. Santos, Juscelino P. Silva and Paulo A.A. Sousa

The main goal of this paper is to present a complete description of all translation hypersurfaces with constant r-curvature Sr, in the Euclidean space R^{n+1}, where 3 ≤ r ≤ n-1.

Read here

3-On reduced L² cohomology of hypersurfaces in spheres with finite total curvature
Author: Peng Zhu

In this paper, we prove that the dimension of the second space of reduced L² cohomology of M is finite if M is a complete noncompact hypersurface in a sphere Sⁿ⁺¹ and has finite total curvature (n>2) by use of a moser iteration argument.

Read here

4-On non-Kupka points of codimension one foliations on P³
Authors: Omegar Calvo-Andrade, Maurício Correa and Arturo Fernández-Pérez

We study the singular set of a codimension one holomorphic foliations on projective three-spaces. We find a local normal form of a codimension two component of the singular set that is not of Kupka type. We also determined the number of non-Kupka points immersed in a codimension two component of the singular set of a codimension one foliation on projective three-space.

Read here

CHEMICAL SCIENCES

5-Enhancement of Hevea brasiliensis properties through chemical application
Authors: Roszaini Kadir and Mohad D. Jantan

The performance of four different types of bleaching agents mixed together with 2% boron-based preservative was studied on green sawn rubberwood. Evaluation on the effects of the most bleaching agent on physical, mechanical and biological properties of rubberwood also have been determined. Laboratory results indicated that timber treated with 1% and 2% hydrogen peroxide produced better and more homogeneous colour properties. Hydrogen peroxide gave higher whitish values and lower colour changes when compared to the other three chemicals. The static bending of bleached rubberwood tends to decrease when the level of hydrogen peroxide increased. Biological properties increased with the increasing of chemical concentrations. 

Read here

6-Barium and its Importance as an Indicator of (Paleo) Productivity
Authors: Bianca T.P. Liguori, Marcelo G. de Almeida and Carlos E. de Rezende

Barium, as barite (BaSO₄), has been shown to have relation with organic carbon flux and marine biological debris in the water column. This relationship can indicate direct or indirect involvement in biological cycling in the water column. During decay of organic compounds in the water column barite is formed which can be used to estimate the productivity in surface waters. Barite in the marine environment have been used as a promising (paleo) productivity proxy due to its high preservation rate under oxic conditions, which is higher than the direct proxies for productivity as carbonates and organic carbon, for example.

Read here

EARTH SCIENCES

7-Holocene paleo-sea level changes along the coast of Rio de Janeiro, southern  Brazil: Comment on Castro et al. (2014)
Authors: Rodolfo J. Angulo, Paulo C.F. Giannini, Maria Cristina de Souza and Guilherme C. Lessa

The present work discusses and reinterprets paleo-sea level indicators used to build Holocene sea-level curve for the coast of Rio de Janeiro at former works. We conclude that, when correctly interpreted, they are compatible with the eustatic sea-level curve and the sea-level envelope proposed for the Brazilian coast and with former data published from the coast of Rio de Janeiro. We also conclude that: (a) the paleo-sea levels inferred by vermetid remains show that sea-level has fallen over the past 4400 years, at least; (b) the paleo-sea level inferred by the beachrock facies and dated shells of Jaconé shows that sea-level was near the present elevation between 8198 and 5786 years before present; and (c) several shells from other beachrocks were deposited probably thousands of years after the specimens died and consequently do not allow precise reconstructions of paleo-sea levels.

Read here

8-First Occurrence and Paleo-Ecological Implications of Insects (Orthoptera: Ensifera Gryllidae) in the Romualdo Member of the Santana Formation, Eo-Cretaceous of the Araripe Basin
Authors: Luís C.B. Freitas, Geraldo J.B. de Moura and Antônio A.F. Saraiva

The Romualdo Member of the Santana Formation of the Araripe Basin is famous for its preserved fossils in calcareous concretions, which stand out for their diversity and excellent preservation levels. This paper aims to record the first occurrence of the Class Insecta (Orthoptera:Gryllidae) in the Romualdo Member, as well as to describe and discuss the paleo-ecological implications of such finding. This new species is attributed to the genus Araripegryllus,that lasted throughout the deposition of the Crato Member, which is under the Romualdo Member. In reference to its statigraphic origin, the specimens was named Araripegryllus romualdoi.

Read here

9-Geostatistical Approach for Spatial Interpolation of Meteorological Data
Authors: Derya Ozturk and Fatmagul Kilic

In recent years, with the developments in Geographical Information System (GIS) technology, geostatistical methods have become popular in the analysis of the spatial data. In this study, spatial distributions of precipitation and temperature of the Aegean Region in Turkey for years 1975, 1980, 1985, 1990, 1995, 2000, 2005 and 2010 in 5-year periods were determined by the Ordinary Kriging method which is one of the geostatistical interpolation methods using the time series of monthly precipitation and temperature data from 98 meteorological stations. The changes realized in 5-year periods were determined and the results were statistically examined using cell and multivariate statistics. The results revealed that a significant change in precipitation regime in the Aegean Region has occurred.

Read here

10-Dating stalagmite from Caverna do Diabo (Devil´S Cave) by TL and EPR techniques
Authors: Shigueo Watanabe, Nilo F. Cano, T.K. Gundu Rao, Betzabel N. Silva-Carrera, Lucas S. Carmo, Antonio J.A. Quina, Roseli F. Gennari, Casimiro S. Munita, Jorge S. Ayala-Arenas and Bruno G. Fernandes

Many caves are characterized by large stalagmite, stalactite and other  compounds, altogether called speleothems. How old they are and what was growth rate, besides their chemical contends are of geological and physics interests. The Caverna do Diabo (Devil´s Cave) is known not only for its extension, but mainly the huge speleothems it contains. It is not allowed to collect pieces of speleothems, but we were able to obtain a fragment of stalagmite found in the ground. With permission of manager of the Cave a fragment of stalagmite of about 40 cm long and 5 to 6 cm diameter was collected and its age and growth rate have been measured by thermoluminescent technique.

Read here

11-Cordão Formation: loess deposits in the southern coastal plain of the state of Rio Grande do Sul, Brazil
Authors: Renato P. Lopes, Sergio R. Dillenburg and Cesar L. Schultz

This paper describes loess deposits in the southern coastal plain of Rio Grande do Sul, designed as a new lithostratigraphic unit, named Cordão Formation. This formation consists of up to 2 meter-thick, silt-dominated deposits found beneath the modern soil. Its mineral composition indicates that it was transported from Argentina by increased aeolian processes during the last glacial stage, between 30 and 10 kyrs ago. The absence of interbedded soils or fluvial deposits within this formation, and the scarcity of fossil mammalian remains indicate that the southernmost Brazil experienced semiarid (dry and cold) conditions during the latest Pleistocene.

Read here

12-Paralavas in the Cretaceous Paraná volcanic province, Brazil – A genetic interpretation of the volcanic rocks containing phenocrysts and glass
Authors: Sérgio B. Baggio, Léo A. Hartmann and Rosa M.S. Bello

One sixth of the Brazilian territory is covered by basalts and rhyodacites of the Paraná volcanic province. The rocks are mineralized in amethyst geodes and native copper. We solved a paradox, because thick (30-80 m) basalt lavas display large (10 cm), hollow and skeletal crystals of clinopyroxene, plagioclase and magnetite in a glassy matrix. The ignition of methane in a hot (1,000 ºC) basalt raised the temperature to ˃1,500 ºC and remelted the rock forming the paralavas. This is a novel contribution to the understanding of remelting and mineralization in basaltic massifs.

Read here

13-Hourly interaction between wind speed and energy fluxes in Brazilian Wetlands - Mato Grosso - Brazil
Authors: Thiago R. Rodrigues, Leone F.A. Curado, Vinicius M.R. Pereira, Luciana Sanches and José S. Nogueira

Matter and energy flux dynamics of wetlands are important to understand environmental processes that govern biosphere-atmosphere interactions across ecosystems. This study presents analyses about hourly interaction between wind speed and energy fluxes in Brazilian Wetlands - Mato Grosso - Brazil. Results presented same patterns in energies fluxes in all period studied. Wind speed and air temperature presented same patterns, while LE was relative humidity presented inverse patterns of the air temperature. Analyses of linear regression presented positive interactions between wind speed and LE, and wind speed and H in all seasons.

Read here

14-Influence of seasonal variation on the hydro-biogeochemical characteristics of two upland lakes in the Southeastern Amazon, Brazil
Authors: Prafulla K. Sahoo, José T.F. Guimarães, Pedro W.M. Souza-Filho, Marcio S. da Silva, Renato O. Silva Júnior, Gustavo Pessim, Bergson C. de Moraes, Paulo F.P. Pessoa, Tarcísio M. Rodrigues, Marlene F. da Costa and Roberto Dall’Agnol

The hydro-biogeochemical characteristics of the Violão and Amendoim lakes, Serra dos Carajás, were studied in 2013-2014. The hydroclimatic data indicate that the lake levels were strongly influenced by local rainfall patterns. Both lakes are classified as classes “1” and “2” in the CONAMA scheme and as “excellent” to “good” in the Water Quality Index (WQI) categories. However, the limnology is distinctly different between the lakes and seasons. Higher trophic state and phytoplankton productivity were observed mainly during the rainy period in Violão Lake compared to Amendoim Lake. This may be highly influenced by catchment lithology and seasonal weather variability.

Read here

BIOLOGICAL SCIENCES

15-Local Anesthetic Activity from Extracts, Fractions and Pure Compounds from the Roots of Ottonia anisum Spreng. (Piperaceae)
Authors: Kelvin S.E. López, André M. Marques, Davyson de L. Moreira, Leosvaldo S. Velozo, Roberto T. Sudo, Gisele Zapata-Sudo, Elsie F. Guimarães and Maria Auxiliadora C. Kaplan

In Brazil, species of Piperaceae are used in some communities as local anesthetic and analgesic. Ottonia anisum a species popularly knownas “anestesia” in some regions and it is a common habit of chewing leaves and roots of Ottonia species to relief toothache in North of Brazil. In this work, phytochemical investigations on methanol extract and its n-hexane fraction from roots O. anisum led to the isolation and characterization of several bioactive amides with significant anesthetic effects, which are in agreement with ethnobotanical survey.

Read here

16-Agaricus subrufescens: substratum nitrogen concentration and mycelial extraction method on antitumor activity
Authors: Míria B.D. Bertéli, Ana D. Lopes, Itaruã M. Colla, Giani A. Linde and Nelson B. Colauto

This study evaluated the effect of nitrogen concentration on the cultivation medium of Agaricus subrufescens and the extraction method of mycelial antineoplastic actives against sarcoma 180 cells implanted in mice. Mycelial biomass production increases when cultivation medium is added with high nitrogen concentrations as well as the splenic index and the antitumor activity of moistened mycelial powder. Hot water extract is more effective than moistened mycelial powder to reduce tumor. The antitumor activity of hot water mycelial extract is similar to the one of basidiocarps, presenting lower metabolic demand on the spleen, keeping blood parameters normal and promoting animal wellness.

Read here

17-Method validation for determination of metals in Vitis labrusca L. grapevine leaf extracts by inductively coupled plasma mass spectrometry (ICP-MS)
Authors: Liane V.V. Bokowski, Roberto B. Sobrinho, Cristián J.V. Armijo, Caroline Dani, João A.P. Henriques and Cláudia Funchal

The aim of this study was to develop and validate an analytical methodology to determine the metals selenium (96Se), chromium (53Cr), nickel (62Ni), cadmium (111Cd) and lead (206Pb) using inductively coupled plasma mass spectrometry (ICP-MS) in Vitis labrusca L. grapevine leaves the main species of grapes used for wine and juice production in Brazil. The method showed linearity, precision, accuracy and limits of quantification and detection acceptable for INMETRO protocol validation of analytical methods and the proposed method could be applied in routine analytical laboratory.

Read here

BIOMEDICAL SCIENCES

18-The Complex Link between Apoptosis and Autophagy: a Promising New Role for RB
Authors: João M.A. Delou, Deborah Biasoli and Helena L. Borges

Inactivation of Retinoblastoma (RB) pathway is one of the earliest and more frequent hallmarks of cancer. RB can regulate critical cellular processes modified in cancer, as proliferation, cell death, and recently also autophagy. The latter is the process of recycling organelles and molecules that can either support or hamper cancer development and resistance. Here, we discuss RB as a new link between autophagy and cell death and review current strategies to improve response to antineoplastic cocktails by interfering with autophagy.

Read here

19-Iron restriction increases myoglobin and protein expression in Soleus muscle of rats
Authors: Janaina S. de Souza, Erika L. Brunetto and Maria Tereza Nunes

Iron is an important trace element for the cells and 15% of its content is present in muscles. Iron deficiency is one of the biggest problems in public health worldwide. This study provides new insights in iron importance for postural muscle. Herein we show that iron restriction increases myoglobin gene and protein expression in the Soleus muscle in rats during a certain period of treatment with an iron chelator. This increase might be a protective response of the tissue to a more severe iron deficiency that can affect the body.

Read here

HEALTH SCIENCES

20-Analysis of labour risks in the Spanish industrial aerospace sector
Authors: Juan Laguardia, Emilio Rubio, Ana Garcia and Rafael Garcia-Foncillas

We applied the ACSOM method for data mining and predictive analysis to identify the preeminent occupational hazards within the Spanish Industrial Aerospace Sector (SIAS) and therefore, prioritise the most appropriate preventive actions. We equated by deviation and translocation of labour pitfall reference patterns from aerospace (AS) and general industrial (IS) sectors. We hereby infer that radiation poses the greater workplace threat, oddly either in the IS and the AS, followed by overstrain. These findings could be used to improve risk prevention strategies by classifying them into primary and secondary menace phases using ACSOM method.

Read here

21-Formulation and in vitro evaluation of carbopol 934-based modified clotrimazole gel for topical application
Authors: Muhammad Ubaid, Sadaf Ilyas, Sadullah Mir, Abida K. Khan, Rehana Rashid, Muhammad Z.U. Khan, Zainab G. Kanwal, Ahmad Nawaz, Amna Shah and Ghulam Murtaza

This study was conducted to make drug loaded gel for treating fungal infection of skin. The antifungal drug used in study was clotrimazole. To increase the effectiveness of this gel, special compounds, known as permeability enhancers, were used. We tried biological oils including coconut and pistachio oil as permeability enhancers. These enhancers increased the permeation of clotrimazole across skin without producing toxic effects on rat skin. Moreover, the prepared gel produced antifungal effect against various fungal strains (such as Candida albicans, Aspergillus niger and Mucor) comparable to that of clotrimazole.

Read here

22-Popular medicinal uses of Calea uniflora Less. (Asteraceae) and its contribution to the study of Brazilian medicinal plants
Authors: Luan S. Ramos, Paula S. Cardoso, Michele D. Freitas, Renato Paghan, Marília S. Borges, Vanilde Citadini-Zanette, James W. Barlow, Patrícia A. Amaral and Silvia DalBó

The article “Popular medicinal uses of Calea uniflora Less. (Asteraceae) and its contribution to the study of Brazilian medicinal plants" is a research with people who use the plant popularly known as “arnica” in the southern region of Santa Catarina. We were interested in Arnica because the frequent use by the population and the beneficial effects of it informally reported. Then, because there was a gap in the literature, we idealized the work in order to identify the percentage of use of the plant, how and for which the plant is used. This research may be serve as basis for the development of other studies with the plant, as well as reference as the local use.

Read here

23-Genotypic carriers of the obesity-associated FTO polymorphism exhibit different cardiometabolic profiles after an intervention
Authors: Greice G. Moraes, Cézane P. Reuter, Jane D.P. Renner, Elisa I. Klinger, Michele B. Ferreira, Elza D. de Mello, Andréia de M. Valim and Miria S. Burgos

Children and adolescents with at-risk genotypes (AA/AT) of the rs9939609 polymorphism in FTO, a fat mass and obesity-associated gene, may exhibit different cardiometabolic profile responses than subjects with the TT genotype after an interdisciplinary intervention. A quasi-experimental study was conducted with 36 school children from southern Brazil. We observed no significant differences among the groups (AA, AT and TT) after the intervention. However, we observed improvements in three parameters (waist circumference, hip circumference and C-reactive protein) in the AT/AA genotype group and in two parameters (hip circumference and uric acid) in the TT genotype group.

Read here

24-New carbohydrazide derivatives of 1H-pyrazolo[3,4-b]pyridine and trypanocidal activity
Authors: Raquel R.S. Salvador, Murilo L. Bello, Igor R.L. Barreto, Maria A.F. Vera, Estela M.F. Muri, Sérgio de Albuquerque and Luiza R.S. Dias

New carbohydrazides derived from 3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine were evaluated in order to identify the antiparasitic profile against Trypanosoma cruzi. These substances showed different activity profiles and since the trypomastigote is the infectious form and the amastigote is the intracellular proliferation form of the parasite, the active compound on the amastigote form can provide information about the capacity of the drugs to target intracellular organism. The replacement at C-6 position by phenyl, methyl or trifluoromethyl groups promoted significant stereoelectronic and lipophilic changes that affected the trypanocidal activity. These findings should contribute to the planning of new active molecules for this target.

Read here

25-Insulin-like Growth Factor 1 gene polymorphism and breast cancer risk
Authors: Danylo R. Costa-Silva, Maria da Conceição Barros-Oliveira, Rafael S. Borges, Cléciton B. Tavares, Umbelina S. Borges, Francisco A. Alves-Ribeiro, Vladimir C. Silva and Benedito B. da Silva

Insulin-like Growth Factor-1 (IGF-1) gene polymorphism has been associated with an increased risk for breast cancer. IGF-1 is a key regulator of proliferation, cell differentiation and apoptosis. It has important mitogenic and anti-apoptotic activities in normal cells and in breast cancer cells, acting synergistically with estrogen to increase neoplastic cell proliferation. This review aims to present the recent finds of IGF-1 gene polymorphism and its relationship with the risk of breast cancer through polymorphic variants by searching in the PubMed database publications focused studies published from 2010 to 2015 related to IGF-1 gene polymorphism and breast cancer risk.

Read here

AGRARIAN SCIENCES

26-Evaluation of deciduous broadleaf forests mountain using satellite data using neural network method near Caspian Sea in North of Iran
Author: Seyed A. Hashemi

The Caspian forests in north of Iran and the aim to determine deciduous broadleaf forests in mountain area with satellite data, used ETM+ Data from 2013. Forest area in northern Iran, the most important of vegetation in Iran. This study evaluated changes in forests area in 2013 using satellite images with neural network method. After selecting the best set of band using the Bhattacharya distance index, the image classification was performed by using artificial neural network algorithm. The neural network method has high accuracy in results.

Read here

27-Genetic structure from the oldest Jatropha germplasm bank of Brazil and contribution for the genetic improvement
Authors: Dalilhia N. dos Santos, Juliano L. Ferreira, Tesfahun A. Setotaw, Geraldo M.A. Cançado, Moacir Pasqual, Luciana C.N. Londe, Heloisa M. Saturnino and Wagner A. Vendrame

Jatropha is an oilseed crop, which requires mitigating factors such as the low genetic variability. The solution runs through the research of Brazilian germplasm. Thus, we aimed to investigate the genetic diversity of 48 accessions of germplasm bank of EPAMIG using SSR and ISSR markers. The results showed low genetic diversity, but some individuals stood out as the access J. mollíssima, J. podagrica and some Mexican and national access. Therefore, it is suggested to explore such as parental genotypes to increase the genetic variability of the jatropha germplasm.

Read here

28-Effects of irrigation intervals and organic manure on morphological traits, essential oil content and yield of oregano (Origanum vulgare L.)
Authors: Farzad Gerami, Parviz R. Moghaddam, Reza Ghorbani and Abbas Hassani

Over-utilization and exploitation of medicinal plants from the wild habitat is led to genetic diversity loss of these valuable plants. For cultivation of threatened plants under field conditions, different management practices are required including awareness of ecological properties of plants, nutrient, water requirements, etc. In order to evaluate the effect of irrigation intervals and cattle manure on growth and yield of oregano, an experiment was conducted in Iran. In general, it seems that cultivation of oregano with three weeks irrigation intervals and use of 30 t.ha^-1 cattle manure is a good practice for achieving high essential oil content and yield.

Read here

ENGINEERING SCIENCES

29-Production of crispy bread snacks containing chicken meat and chicken meat powder
Authors: Hulya Cakmak, Burak Altinel, Seher Kumcuoglu, Duygu Kisla and Sebnem Tavman

Chicken meat with its favorable amino acid composition is a good and cheap animal protein source; however, the availability and accessibility is limited due to its shorter shelf life. The aim of this study was to produce healthy snacks with addition of chicken meat powder and chicken meat for protein enrichment. Protein contents of the snacks were between 15.47 and 21.16%, and quality parameters such as moisture, pH, hardness as well as the microbial count and the TBA value were kept constant during three months of storage at room temperature in a special laminated package.

Read here

30-Experimental validation of a bearing wear model using the directional response of the rotor-bearing system
Authors: Tiago Henrique Machado and Katia L. Cavalca

The paper presents an experimental validation of a wear model previously proposed by the authors. A test rig was assembled in order to evaluate the behavior of the rotating system when supported by hydrodynamic bearings with different wear patterns. The experimental measurements are used to validate the wear model, comparing the anisotropy influence on the experimental and numerical responses. The simulated directional frequency responses showed a good agreement with the experimental ones, demonstrating the potential of the proposed wear model in satisfactorily represent its influence on the rotor-bearings system response.

Read here

31-Contributions of the complexity paradigm to the understanding of Cerrado's organization and dynamics
Authors: Sérgio H.V.L. de Mattos, Luiz E. Vicente, Archimedes Perez Filho and José R.C. Piqueira

The organization and the dynamics of Brazilian Cerrado remains an intriguing puzzle. Here is presented how the complexity paradigm may provide another view for solving this puzzle. Based on theoretical concepts related to dynamic systems, it is suggested that the occurrence of a given Cerrado physiognomy derives from the inter-relationships among several aspects. It is also discussed how complexity paradigm can strongly contribute to understanding the stability of the Cerrado towards disturbances – both anthropogenic and natural. The application of the multistability and self-organized criticality concepts may be very useful for understanding the dynamics of the Cerrado.

Read here

32-Ecohydrological modeling and environmental flow regime in the Formoso River, Minas Gerais State, Brazil
Authors: Hugo A.S. Guedes, Demetrius D. Silva, Jorge A. Dergam and Abrahão A.A. Elesbon

The balance of the ecosystem is one of the main principles that promote the sustainable development of water resources. This paper examines the influence of the ecology of the rivers on the Formoso River – Brazil. It analyzes the biotic and abiotic variables according to the minimum flows permitted for a good planning and a sustainable management of water resources, using the River2D model. It proposes that environmental flows have space and time variability and that fixing only one constant reference flow value along a year damages the aquatic fauna. Thus, it demonstrates the importance of ecohydrology in water resources management.

Read here

33-Numerical Study of Wake Characteristics in a Horizontal-Axis Hydrokinetic Turbine
Authors: Paulo A.S.F. Silva, Taygoara F. de Oliveira, Antonio C.P. Brasil Junior and Jerson R.P. Vaz

In this paper, we report a Computational Fluid Dynamics (CFD) simulation of a hydrokinetic turbine considering the rotor close from the river surface and its implication on the wake. This is significant because the depth and width of rivers are a constrained factor in a power plant. This paper presents a study of the velocity recovery in a hydrokinetic turbine Wake and its turbulence behavior. In addition, it is showed the influence which the river surface may cause an expansion of the Wake. The methodology is reported here for CFD simulations of both hydrokinetic and wind turbines which were validated against a benchmark experiment.

Read here

Annals of the Brazilian Academy of Sciences
aabc@abc.org.br

| unsubscribe |