Numerical analysis of air flow past the 2415-3S airfoil for an unmanned aerial vehicle with internal propulsion system

This paper deals with the prediction of pressure and velocity fields on the 2415-3S airfoil which will be used for and unmanned aerial vehicle with internal propulsion system and in this way analyze the air flow through an internal duct of the airfoil using computational fluid dynamics. The main objective is to evaluate the effect of the internal air flow past the airfoil and how this affects the aerodynamic performance by means of lift and drag forces. For this purpose, three different designs of the internal duct were studied; starting from the base 2415-3S airfoil developed in previous investigation, basing on the hypothesis of decreasing the flow separation produced when the propulsive airflow merges the external flow, and in this way obtaining the best configuration. For that purpose, an exhaustive study of the mesh sensitivity was performed. It was used a non-structured mesh since the computational domain is tridimensional and complex. The selected mesh contains approximately 12.5 million elements. Both the computational domain and the numerical solution were made with commercial CAD and CFD software respectively. Air, incompressible and steady was analyzed. The boundary conditions are in concordance with experimental setup in the AF 6109 wind tunnel. The k-ε model is utilized to describe the turbulent flow process as followed in references. Results allowed obtaining pressure and velocity contours as well as lift and drag coefficients and also the location of separation and reattachment regions in some cases for zero degrees of angle of attack on the internal and external surfaces of the airfoil. Finally, the selection of the configuration with the best aerodynamic performance was made, selecting the option without curved baffles.

Self-organized defensive behavior in honeybees

We investigated the defensive behavior of honeybees under controlled experimental conditions. During an attack on two identical targets, the spatial distribution of stings varied as a function of the total number of stings, evincing the classic “pitchfork bifurcation” phenomenon of nonlinear dynamics. The experimental results support a model of defensive behavior based on a self-organizing mechanism. The model helps to explain several of the characteristic features of the honeybee defensive response: (i) the ability of the colony to localize and focus its attack, (ii) the strong variability between different hives in the intensity of attack, as well as (iii) the variability observed within the same hive, and (iv) the ability of the colony to amplify small differences between the targets.

Metal ion-mediated substrate-assisted catalysis in type II restriction endonucleases

The 2.15-Å resolution cocrystal structure of EcoRV endonuclease mutant T93A complexed with DNA and Ca2+ ions reveals two divalent metals bound in one of the active sites. One of these metals is ligated through an inner-sphere water molecule to the phosphate group located 3′ to the scissile phosphate. A second inner-sphere water on this metal is positioned approximately in-line for attack on the scissile phosphate. This structure corroborates the observation that the pro-SP phosphoryl oxygen on the adjacent 3′ phosphate cannot be modified without severe loss of catalytic efficiency. The structural equivalence of key groups, conserved in the active sites of EcoRV, EcoRI, PvuII, and BamHI endonucleases, suggests that ligation of a catalytic divalent metal ion to this phosphate may occur in many type II restriction enzymes. Together with previous cocrystal structures, these data allow construction of a detailed model for the pretransition state configuration in EcoRV. This model features three divalent metal ions per active site and invokes assistance in the bond-making step by a conserved lysine, which stabilizes the attacking hydroxide ion nucleophile.

The octadecanoic pathway: signal molecules for the regulation of secondary pathways.

Plant defense against microbial pathogens and herbivores relies heavily on the induction of defense proteins and low molecular weight antibiotics. The signals between perception of the aggression, gene activation, and the subsequent biosynthesis of secondary compounds are assumed to be pentacylic oxylipin derivatives. The rapid, but transient, synthesis of cis-jasmonic acid was demonstrated after insect attack on a food plant and by microbial elicitor addition to plant suspension cultures. This effect is highly specific and not caused by a number of environmental stresses such as light, heavy metals, or cold or heat shock. Elicitation of Eschscholtzia cell cultures also led to a rapid alkalinization of the growth medium prior to jasmonate formation. Inhibition of this alkalinization process by the protein kinase inhibitor staurosporine also inhibited jasmonate formation. The induction of specific enzymes in the benzo[c]phenanthridine alkaloid pathway leading to the antimicrobial sanguinarine was induced to a qualitatively and quantitatively similar extent by fungal elicitor, methyl jasmonate, and its linolenic acid-derived precursor 12-oxophytodienoic acid. It is herein proposed that a second oxylipid cascade may exist in plants starting from linoleic acid via 15,16-dihydro-12-oxophytodienoic acid to 9,10-dihydrojasmonate. Experiments with synthetic trihomojasmonate demonstrated that beta-oxidation is not a prerequisite for biological activity and that 12-oxophytodienoic acid and derivatives are most likely fully active as signal transducers. Octadecanoic acid-derived compounds are essential elements in modulating the synthesis of antibiotic compounds and are thus integral to plant defense.

O uso do eucalipto em sistemas silvipastoril: acúmulo de fitomassa arbórea e de pastagem

O presente estudo foi dividido em três capitulos, todos realizados na Estação Experimental de Ciências Florestais de Anhembi/SP, entre os anos de 2014 e 2015. O primeiro estudo intitulado de \"Variação mensal da fitomassa da forragem em função do grau de cobertura do dossel em sistemas silvipastoris\", foi realizado em 3 monoculturas de 13 anos de idade, com área útil de 50 m x 30 m para coleta de pasto as mesmas efectuadas mensalmente. Os resultados apresentaram que não há relação significativa entre a cobertura do dossel e fitomassa da forragem pelo caso de que o sub-bosque estava muito sombreado. Entretanto, houve uma relação indireta entre área basal e fitomassa. Evidenciando-se que o talhão de Eucalipto urograndis apresentou as melhores condições de crescimento e disponibilidade de materia seca mensal para Bachiaria decumbens além de obter a maior porcentagem de folha entre todos os tratamentos. Ao contrario, no talhão de Pinus tecunumanii, foi encontrada a menor disponibilidade de materia seca mensal e por consequência, menor porcentagem de folha. O segundo estudo foi chamado de: \"Disponibilidade de fitomassa de B. decumbens, em um sistema silvipastoril com eucalipto: o papel da radiação\" onde o componente florestal foi o eucalyptus (COP-1377) de 2 anos de idade plantado em uma área útil de 10 ha, dividido em 3 tratamentos (onda longa-OL (39 m), onda curta-OC (21 m), e testemunha-T) e instalado em 4 blocos distintos. Foram realizadas duas coletas dutante o período de verão e de inverno, onde foi possível verificar que o tratamento OL mostrou maior disponibilidade de fitomassa a 65% de irradiância além de obter maior porcentagem da fração folha. Este foi favorecido pelo maior espaçamento entre as aléias. Contudo, houve ataque de cigarinha na pastagem, mantendo a queda da disponibilidade no período de inverno. O terceiro estudo intitulado de: \"Variaçoes arquiteturais de uma monocultura de E. urograndis em função de sua posição espacial\", foi também realizado na monocultura do primeiro estudo, numa área de 7 ha. Para este estudo, realizou-se um inventario florestal, logo após, dividiu-se as árvores por sua classe diamétrica e selecionou-se aleatoriamente 60 árvores para cubagem, e destas, escolheu-se 15 para determinação da fitomassa e respectiva densidade da madeira. Para a obtenção da fitomassa dividiu-se as árvores em três frações de análise: tronco, galhos e folha. Além disso, as 15 árvores foram divididas em: bordadura, intermediária e centro da parcela, de acordo com a sua localização. Verificou-se que a bordadura apresentou os maiores crescimentos em DAP, altura, largura de copa e, que por consequência, obteve maior volume e fitomassa em todas suas frações. Também foi possível observar que tanto a bordadura quanto o centro apresentaram maior densidade básica em função da maior copa e altura das árvores incentivando a geração de mais fitomassa foliar. Finalmente conforme os três estudos realizados neste trabalho de pesquisa, concluiu-se que a radiação solar é fator chave na produtividade da cultura forrageira, demonstrando a necessidade de mais pesquisas sobre os sistemas agroforestais e silvipastoris para o sucesso de futuros emprendimentos.

Havana, Cuba, 1762 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A plan of the Havana and its environs : with several posts and attacks made by the British forces under the command of the Earl of Albemarle and Sr. Geo. Pocock which was taken 13 Aug. 1762, Ths. Kitchin sculpt. engraver to H.R.H. the Duke of York. It was published by J. Boydell engraver in Cheapside & R. Willcock bookseller in Cornhill, Novr. 1st 1762. Scale [ca. 1:24,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'NAD 1927 Cuba Norte' coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map.This map shows features associated with the British Siege of Havana, 1762, such as roads, drainage, built-up areas and selected buildings, fortifications, lines of fire, troop placement, ship locations, ground cover, and more. Relief is shown by hachures; Depths are shown by soundings. Includes indexes for: References to the Moro -- Attack on the Moro -- References to the Town and Harbour -- Attack on the Town and Defences of that Side.This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

The war of nerves with Iran - consequences for the South Caucasus and Russia. OSW Commentary No. 75, 2012-04-25

Tensions over Iran’s nuclear programme have risen considerably in recent months. This has been visible in numerous threats of – and much speculation about – an imminent Israeli (and US) attack on Iran’s nuclear installations. In this context, the support for the attacks that the countries of the South Caucasus (and Azerbaijan in particular) could provide has been the subject of lively debate, as has been the prospect of a Russian political and military offensive in the Caucasus in response to the attacks on Iran. It seems that the ongoing war campaign in the media has been aimed primarily at putting pressure on Iran and the international community to find a political solution to the Iranian problem. This also applies to the Caucasus’s involvement in the campaign. Given the outcome of the Istanbul round of talks on a political solution to the Iranian issue (14 April), which warrants moderate optimism, the threat of a conflict now appears more distant and this also indirectly proves the effectiveness of the campaign. The war of nerves with Iran, however, is already now actually affecting the stability of the Southern Caucasus. While it seems that Azerbaijan is not Israel’s partner in the preparations to attacks, and that there is no real link between the Iranian problem and the ongoing and planned movements of Russian troops in the Caucasus, the tensions between Iran and Azerbaijan are indeed high. Moreover, the global image of the Caucasus is deteriorating, the USA’s position in the region is becoming more complicated, and Russia’s room for manoeuvre is expanding.

Shakers.

"The Legislature of New Hampshire and their constitutuion": p. 4-7; "Minority report of the Judiciary Committee, upon the petition of Franklin Munroe and others in relation the the Society of Christians called Shakers": p. 7-12.

History of the world war,

v.1. The attack on France. - v.2. The making of middle Europe - v.3. Verdun and the Somme. - v.4. America and Russia. - v.5. The victory of armistice.

Acusacion pronunciada ante el Tribunal de jurados de Lima por el doctor Don Juan Ascencio contra el "Alcance al Mercurio peruano"

In the "Alcance al Mercurio peruano," Lima, 1833, Rodríguez made a violent attack on General O'Higgins, who at once instituted suit for libel. The "Acusacion," an elaborate defence of O'Higgins, is chiefly a compilation of documents relating to his revolutionary career, ostensibly by Ascencio, but in reality prepared by José Joaquín de Mora. cf. Prólogo, t. 12; also, Figueroa, Dicc. biog. de estranjeros en Chile, 1900, p. 154, where the name Ascencio is asserted to be a pseudonym.

The chances of death, and other studies in evolution.

"Errata" slip tipped in at v. 1, p. [1]; Addenda slip tipped in at v. 2, p. [413]

The minor : a comedy, as it is now acting at the new theatre in the Hay-Market /

An attack on George Whitefield and the Methodists.

A letter from Henry Woodward, comedian, the meanest of all characters; (see Inspector, no.524.) to Dr. John Hill, inspector-general of Great-Britain, the greatest of all characters; (see all the Inspectors.)

A reply to an attack on Woodward by Hill, the authorship of which has also been attributed to Henry Fielding and to Fielding and David Garrick jointly.--Cf. UCLA.

Resumption of the arguments & observations more immediately directed in his last letter to Lord John Russell, but in this to Lord Melbourne, with a view to shew the imprudence and folly of lending their great names to countenance revolutionists & infidels.

Attack on Robert Owen.

Lady Cheveley; or, The woman of honour.

A satire in verse, written in answer to Lady Bulwer-Lytton's attack on her husband in "Cheveley, the man of honour."