Chemical composition of ocean manganese nodules from the Pacific Ocean using different techniques

Mineralogical and chemical analyses performed on 67 ferromanganese nodules from widely varying locations and depths within the marine environment of the Pacific Ocean indicate that the minor element composition is controlled by the mineralogy and that the formation of the mineral phases is depth dependent. The pressure effect upon the thermodynamics or kinetics of mineral formation is suggested as the governing agent in the depth dependence of the mineralogy. The minor elements, Pb and Co, appear concentrated in the dMnO2 phase, whereas Cu and Ni are more or less excluded from this phase. In the manganites, Pb and Co are relatively low in concentration, whereas Cu and Ni are spread over a wide range of values. The oxidation of Pb and Co from divalent forms in sea water to higher states can explain their concentration in the dMnO2 phase.

On the microstructure, growth pattern and original porosity of belemnite rostra: insights from calcitic Jurassic belemnites

Calcitic belemnite rostra are usually employed to perform paleoenvironmental studies based on geochemical data. However, several questions, such as their original porosity and microstructure, remain open, despite they are essential to make accurate interpretations based on geochemical analyses.This paper revisits and enlightens some of these questions. Petrographic data demonstrate that calcite crystals of the rostrum solidum of belemnites grow from spherulites that successively develop along the apical line, resulting in a “regular spherulithic prismatic” microstructure. Radially arranged calcite crystals emerge and diverge from the spherulites: towards the apex, crystals grow until a new spherulite is formed; towards the external walls of the rostrum, the crystals become progressively bigger and prismatic. Adjacent crystals slightly vary in their c-axis orientation, resulting in undulose extinction. Concentric growth layering develops at different scales and is superimposed and traversed by a radial pattern, which results in the micro-fibrous texture that is observed in the calcite crystals in the rostra.Petrographic data demonstrate that single calcite crystals in the rostra have a composite nature, which strongly suggests that the belemnite rostra were originally porous. Single crystals consistently comprise two distinct zones or sectors in optical continuity: 1) the inner zone is fluorescent, has relatively low optical relief under transmitted light (TL) microscopy, a dark-grey color under backscatter electron microscopy (BSEM), a commonly triangular shape, a “patchy” appearance and relatively high Mg and Na contents; 2) the outer sector is non-fluorescent, has relatively high optical relief under TL, a light-grey color under BSEM and low Mg and Na contents. The inner and fluorescent sectors are interpreted to have formed first as a product of biologically controlled mineralization during belemnite skeletal growth and the non-fluorescent outer sectors as overgrowths of the former, filling the intra- and inter-crystalline porosity. This question has important implications for making paleoenvironmental and/or paleoclimatic interpretations based on geochemical analyses of belemnite rostra.Finally, the petrographic features of composite calcite crystals in the rostra also suggest the non-classical crystallization of belemnite rostra, as previously suggested by other authors.

Almetrics: measuring the influence of the media on the social impact of research

Social media is changing the way we interact, present ideas and information and judge the quality of content and contributions. In recent years there have been hundreds of platforms to freely share all kinds of information and connect across networks. These new tools generate activity statistics and interactions among users such as mentions, retweets, conversations, comments on blogs or Facebook; managers references showing popularity ratings of more references shared by other researchers or repositories that generate statistics of visits or downloads of articles. This paper analyzes that have meaning and implications altmetrics, what are its advantages and critical platforms (Almetric.com, ImpactStory, Plos altmetrics, PlumX), reports progress and benefits for authors, publishers and librarians. It concluded that the value of alternative metrics as a complementary tool citation analysis is evident, although it is suggested that you should dig deeper into this issue to unravel the meaning and the potential value of these indicators to assess their potential.

Target language use : An empirical study of the target language use in the Swedish 4-6 grade classroom

A consistent use of the target language during English lessons is beneficial for pupils’ linguistic development, but also challenging for both teachers and pupils. The main purpose for pupils to learn English is to be able to use it in communication, which requires that they develop the ability to comprehend input, produce output and use language strategies. Several researchers claim that a consistent use of the target language is necessary in order to develop these abilities. Therefore, the aim of this study is to examine the target language use during English lessons in Swedish grades 4-6, and what pupils’ opinions regarding target language use are. The methods used to collect data consisted of a pupil questionnaire with 42 respondents and an observation of two teachers’ English lessons during a week’s time. The results from the observations show that the teachers use plenty of target language during lessons, but the first language as well to explain things that pupils might experience difficult to understand otherwise. The results from the questionnaire mainly show that the pupils seem to enjoy English and like to both speak and hear the target language during lessons. The main input comes from listening to a CD with dialogues and exercises in the textbook and the workbook, and from the teacher speaking. The results also show that a majority of the pupils use the target language in their spare time. A conclusion that can be drawn from this study is that the TL should be used to a large extent in order to support pupils’ linguistic development. However, teachers may sometimes need to use L1 in order to facilitate understanding of the things that many pupils find difficult, for example grammar. Suggestions for further research in this area include similar studies conducted on a larger scale.

Study Of Water Flowrate Using Time Transient And Cross-Correlation Techniques With 82br Radiotracer

This paper aims to determinate the water flowrate using Time Transient and Cross-Correlation techniques. The detection system uses two NaI(Tl) detectors adequately positioned on the outside of pipe and a gamma-ray source (82Br radiotracer). The water flowrate measurements using Time Transient and Cross-Correlation techniques were compared to invasive conventional measurements of the flowmeter previously installed in pipeline. Discrepancies between Time Transient and Cross-Correlation techniques flowrate values were found to be less than 3% in relation to conventional ones.

Evaluation of Cross Correlation Technique to Measure Flow in Pipes of the Oil Industry

The present work is concerned with the use of the cross correlation technique to measure delay time between two simulated signals displaced with respect to time, in order to develop a cross correlator system that will be used to measure the water and oil pipes flowrate in which the detection system is composed by two external low intensity radiation sources located along the tube and two NaI(Tl) gamma-ray detectors. The final purpose of the correlator system is to use the natural disturbances, as the turbulence in the own flow rather than to inject radioactive tracers to the fluid flow as usually is carried out. In the design of this correlator is evaluated the point-by-point calculation method for the cross correlation function in order to produce a system accurate and fast. This method is divided at the same time in three modes of operation: direct, relay and polarity.

Flow Regime Identification Methodology with Mcnp-X Code And Artificial Neural Network

This paper presents flow regimes identification methodology in multiphase system in annular, stratified and homogeneous oil-water-gas regimes. The principle is based on recognition of the pulse height distributions (PHD) from gamma-ray with supervised artificial neural network (ANN) systems. The detection geometry simulation comprises of two NaI(Tl) detectors and a dual-energy gamma-ray source. The measurement of scattered radiation enables the dual modality densitometry (DMD) measurement principle to be explored. Its basic principle is to combine the measurement of scattered and transmitted radiation in order to acquire information about the different flow regimes. The PHDs obtained by the detectors were used as input to ANN. The data sets required for training and testing the ANN were generated by the MCNP-X code from static and ideal theoretical models of multiphase systems. The ANN correctly identified the three different flow regimes for all data set evaluated. The results presented show that PHDs examined by ANN may be applied in the successfully flow regime identification.

Desenvolvimento de Sistema de Aquisição e Análise de Dados para Aplicações de Traçadores Radioativos em Unidades Industriais

Desenvolveu-se no Instituto de Engenharia Nuclear um sistema de aquisição de dados para avaliação das condições operacionais de unidades industriais pelo estudo das curvas Distribuição do Tempo de Residência - RTD, composto de detectores cintiladores NaI (Tl) 3”x 3” conectados a analisadores monocanal cujos sinais são captados por uma interface acoplada a um microcomputador. Para a análise das informações coletadas desenvolveu-se o programa TRACER que efetua um tratamento matemático preliminar dos dados; apresenta na tela a curva RTD, e calcula valores como o tempo de residência médio e as funções resposta, tanto para estímulos instantâneos como para estímulos contínuos. As informações levantadas permitem a identificação de problemas como possíveis canalizações, fugas, zonas mortas e decréscimo na eficiência das unidades. Todo o conjunto é disposto em módulos compactos o que possibilita seu transporte e instalação em unidades industriais.

Undersampled Critical Branching Processes on Small-World and Random Networks Fail to Reproduce the Statistics of Spike Avalanches

The power-law size distributions obtained experimentally for neuronal avalanches are an important evidence of criticality in the brain. This evidence is supported by the fact that a critical branching process exhibits the same exponent t~3=2. Models at criticality have been employed to mimic avalanche propagation and explain the statistics observed experimentally. However, a crucial aspect of neuronal recordings has been almost completely neglected in the models: undersampling. While in a typical multielectrode array hundreds of neurons are recorded, in the same area of neuronal tissue tens of thousands of neurons can be found. Here we investigate the consequences of undersampling in models with three different topologies (two-dimensional, small-world and random network) and three different dynamical regimes (subcritical, critical and supercritical). We found that undersampling modifies avalanche size distributions, extinguishing the power laws observed in critical systems. Distributions from subcritical systems are also modified, but the shape of the undersampled distributions is more similar to that of a fully sampled system. Undersampled supercritical systems can recover the general characteristics of the fully sampled version, provided that enough neurons are measured. Undersampling in two-dimensional and small-world networks leads to similar effects, while the random network is insensitive to sampling density due to the lack of a well-defined neighborhood. We conjecture that neuronal avalanches recorded from local field potentials avoid undersampling effects due to the nature of this signal, but the same does not hold for spike avalanches. We conclude that undersampled branching-process-like models in these topologies fail to reproduce the statistics of spike avalanches.

Qual a contribuição das características antropométricas na velocidade de corrida de curta distância ?

v. 19, n. 2, abr./jun. 2016.

Proprioception in ankle sprain from exercises and bandages

Ankle sprains are the most common injuries in sports, usually causing damage to the lateral ligaments. Recurrence has as usual result permanent instability, and thus loss of proprioception. This fact, together with residual symptoms, is what is known as chronic ankle instability, CAI, or FAI, if it is functional. This problem tries to be solved by improving musculoskeletal stability and proprioception by the application of bandages and performing exercises. The aim of this study has been to review articles (meta-analisis, systematic reviews and revisions) published in 2009-2015 in PubMed, Medline, ENFISPO and BUCea, using keywords such as “sprain instability”, “sprain proprioception”, “chronic ankle instability”. Evidence affirms that there does exist decreased proprioception in patients who suffer from CAI. Rehabilitation exercise regimen is indicated as a treatment because it generates a subjective improvement reported by the patient, and the application of bandages works like a sprain prevention method limiting the range of motion, reducing joint instability and increasing confidence during exercise. As podiatrists we should recommend proprioception exercises to all athletes in a preventive way, and those with CAI or FAI, as a rehabilitation programme, together with the application of bandages. However, further studies should be generated focusing on ways of improving proprioception, and on the exercise patterns that provide the maximum benefit.

The numerical simulation of aircraft evacuation and its application to aircraft safety

Abstract not available

Géodiversité sous-marine de Nouvelle-Calédonie. 1ère partie

The object of this article is to offer a synthesis of the knowledge clarifying the originality and the diversity of the submarine geological formations of the New Caledonian EEZ. A reminder is given onto the geologic history of the region, based upon the dislocation of the Gondwana Continent, the opening of the Tasman Sea, the presence of submarine volcanism, the setting up of heavy peridotitic rocks, the building up of the Fairway and Lord Howe Ridges and of sedimentary basins, the formation of volcanic domes and sea-mounts or guyots, the subduction along the Vanuatu Trench, the uplift of the Loyalty Islands, the development of carbonated ptatforms around the islands etc.... Of this complex history ensues an exceptional submarine geo-diversity. After this presentation the article clarifies the methods and the tools used in marine geosciences to map, explore, observe, analyze, sample, that they are embarked or are autonomous, teleoperated or inhabited systems. A chapter describes the programs which were set up since about forty years and the results obtained as well as the scientific teams concerned with. In conclusion, based on the unpublished character of this geo-diversity, the article introduces the second text to come in a next issue of theTai Kona magazine, text which will focus on the scientific, economic (mineral resources), environmental (deep biodiversity) and risks (seismicity) challenges that are worn by one of the most original submarine geologic context in the world.