52,788 research outputs found
A dádiva, a sovinice e a beleza: economia da Cultura Matis, Vale do Javari, Amazônia
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Antropologia SocialEssa tese trata sobre a economia da cultura dos Matis, um povo indígena amazônico, sua circulação de conhecimentos com o exterior e suas relações com estrangeiros de diferentes matizes. Alguns desses estrangeiros são nëix (animais); outros, tsussin (forças vitais, seres ou potências desencorporadas); outros, nawa (povos indígenas vizinhos, brasileiros ou gringos). Dentre esses últimos, relações econômicas se dão especialmente com jornalistas/ documentaristas, turistas e pesquisadores. Transações diversas são etnografadas em ritos, mitos, práticas xamânicas, filmagens, programas turísticos, comércio de objetos e em outras relações cosmopolitanas. Um ponto fundamental estudado é a afirmação dos Matis de que querem ser um povo numeroso, ser um povo grande. A economia de pessoas está entretecida com as economias da cultura. Os Matis querem desses povos estrangeiros (animais, tsussin, gringos) tecnologias (num sentido amplo) para conseguir crescer, ter corpos mais duros e fortes, serem mais e mais poderosos, mais belos. Os estrangeiros aparecem como os principais outros de quem se quer adquirir poder, tecnologias, estéticas e através de quem se pode expandir pelo cosmos. A tese trata de temas clássicos da etnologia amazônica como economia de pessoas (corpos), com foco em sovinices e circulações de conhecimentos e coisas (transações, aquisições ou roubos de mitos, cantos, poderes xamânicos, farmacopéia, pedaços de corpos, motores e outros bens). Trato de economia, portanto, em uma compreensão generosa, qualquer definição clássica etimológica de #economia# como cuidado, manejo ou organização da casa (do grego "oikos" e "nomia") será alargada aquiThis thesis is about the economy of culture of the Matis - an Amazonian indigenous people, its circulation of knowledge with the outside and its relations with different foreigners. Some of those foreigners are nëix (animals); some, tsussin (vital forces, desincorporated beings or potencies); others are nawa neighbouring indigenous peoples, Brazilians and gringos. Among these last ones, economic relations take place specially with journalists/film makers, tourists and researchers. Several transactions are ethnographed in rites, myths, shamanic practices, filming, touristic programs, objects# trading and in other cosmopolitan relations. A fundamental point of the present study is the Matis# affirmation that they want to be a numerous people, to be bigger. The economy of people is interwoven with the economy of culture. The Matis want from these foreign peoples (animals, tsussin, gringos) technologies (in a broad sense) so that they can grow, to have bodies that are harder and stronger, to be more and more powerful, more beautiful. The foreigners appear as the #special others# from whom to acquire power, technologies, aesthetics and through whom it is possible to expand throughout the cosmos. The thesis treats classic themes in Amazonian ethnology such as economy of people (bodies), with focus in the stinginess and the circulation of knowledge and things (transactions, acquisitions or robberies of myths, songs, shamanic powers, pharmacopoeia, body parts, engines and other stuff). So, I treat economy in a generous comprehension, any classic etymologic definition of #economy# as care, management or organization of the house (from the greek "oikos" and "nomia") will be broaden her
Dinâmica de espécies na agricultura indígena do Vale do Javari - AM: o caso dos Matis e Marubo
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Agroecossistemas.A visão depreciativa em relação à população rural aprofundou o descaso com muitos sistemas de conhecimento nativo, cujo conteúdo era expresso de forma discursiva e simbólica. Poucos trabalhos foram realizados e ainda pouco se conhece sobre os sistemas tradicionais de produção. Os estudos realizados têm demonstrado a diversidade e complexidade dos padrões de cultivo, dos sistemas de manejo e conservação de solos, usos da água, reciclagem de nutrientes, controle da sucessão e proteção das culturas, além da incorporação de grande número de cultivares, importantes para o desenvolvimento de programas de melhoramento genético. A agricultura itinerante constitui a forma tradicional de uso da terra mais praticada na América Latina. Alternando-se períodos de cultivo e regeneração da floresta, é possível manejar a fertilidade do solo e controlar pragas e doenças, estabelecendo policultivos e sistemas agroflorestais com alto grau de sustentabilidade. Nos sistemas tradicionais indígenas da Amazônia, os produtos de maior importância são o milho, a mandioca e a banana, representando as fontes básicas de carboidratos. Com a conquista européia da Amazônia, os cacicados indígenas estabelecidos na várzea e que mantinham forte o cultivo de milho, foram destruídos e os grupos indígenas restantes tiveram que retornar ao cultivo de mandioca, que se mantém como alimento principal para a maior parte das populações nativas até os dias atuais. Em diversos grupos indígenas, no entanto, a banana vem se tornando o cultivo mais importante. É o que vem acontecendo com os índios Matis e Marubo, grupos Pano do Vale do Javari, no Amazonas. Esses grupos praticam uma agricultura de derrubada e queima, conformando sistemas agroflorestais. Constitui o objetivo deste trabalho estudar as razões e conseqüências da substituição de espécies no repertório dos cultivos Matis e Marubo, no contexto atual, cujo fato mais marcante está nas substituições da mandioca e milho pela banana. Utilizando-se metodologias qualitativas em um longo período de convívio com os grupos pesquisados, estudou-se os seus sistemas agrícolas e as mudanças ocorridas, onde a substituição de espécies foi o fator mais relevante. Resultados do trabalho indicaram que a introdução e a adaptação da banana contribuiu para a melhoria do agroecossistema e permitiu aos indígenas se adaptarem melhor à nova realidade pós-contato com a sociedade nacional, além dos ganhos na dieta e no rendimento do trabalho na roça. O conhecimento indígena sobre o seu agroecossistema pode ser visto como um processo co-evolutivo, na medida em que sociedade e sistema agrícola evoluem, mantendo-se as características básicas de interação ecológica
Experimental investigation of plasma impedance in Linac4 source
No full textCERN ’s new particle accelerator Linac4 is part of the upgrade of the LHC accelerator chain. Linac4 is required to deliver 160 MeV H− beam to improve the beam brightness and luminosity in the Large Hadron Collider (LHC). The Linac4 H− source must deliver 40-50 mA, 45 keV H− beam in the RFQ acceptance. Since the RF power coupled to the H− source plasma is one of the important parameters that determines the quality of the H− beam, the experimental investigation of the dependence of the load impedance on the operational parameters is mandatory. In this study, we have measured the impedance of the H− source plasma varying the RF power coupled to the plasma and the condition of the hydrogen gas. Also, optical emission spectroscopy (OES) measurements have been carried out simultaneously with the impedance measurement in order to determine the plasma parameters. The determination of the plasma parameters allows us to compare the experimental results with the analytic model of the plasma parameters, which is useful to discuss the results from a physical point of view
Influence of the cusp field on the plasma parameters of the Linac4 H− ion source
No full textWhen the H ion source of CERN’s Linac4 is operated in volume mode, a maximum of the extracted current is obtained at varying RF power. The power required for this maximum and its absolute value is strongly influenced by the cusp magnets installed at the source for electron confinement: without magnets, 15−20 mA are typically obtained at 20 kW whereas with magnets a factor of two more power is needed and 25−30 mA are achieved. In order to access the reasons behind the peaked performance with varying RF power and for determining the influence of the cusp field on the discharge, optical emission spectroscopy (OES) measurements of the atomic Balmer series and of the molecular Fulcher transition have been carried out. In all investigated cases, the gas temperature of the discharge has been virtually equal to the ambient temperature as the short discharge pulse length of 500 s is not long enough for considerable heavy particle heating. When no cusp magnets are installed, the plasma parameters evaluated with the collisional radiative models Yacora H and Yacora H show a minimum in the electron temperature of 3.25 eV and a maximum in the electron density of and also in the vibrational excitation of the hydrogen molecule at 20 kW. Assessing the relevant production and destruction processes demonstrates that the H yield is maximal at this point thereby explaining the optimum ion source performance. When the cusp magnets are applied, the same general trends are observed but the required RF power is a factor of two higher. The OES results indicate an optimum performance around 30 kW whereas the highest H current is actually achieved around 40 kW. Furthermore, a higher H yield is indicated without cusp magnets but a better ion source performance is observed with magnets. These differences can most likely be attributed to changing gradients in the plasma parameters which are not accessible by OES. Nevertheless, the obtained plasma parameters can be used as benchmark for RF coupling codes simulating the Linac4 ion source
A molecular dynamics study of N-A-S-H gel with various Si/Al ratios
No full textThe understanding of sodium aluminosilicate hydrate (N-A-S-H) gel is still limited due to its complex and amorphous structure. Recently, molecular dynamics simulation has provided a unique opportunity to better understand the structure of N-A-S-H gel from nanoscale. In this work, the N-A-S-H gel structure was obtained by simulating the polymerization of Si and Al monomers by molecular dynamics. The simulated polymerization process is in good agreement with the experimental results especially in terms of the reaction rate of Si and Al species. The atomic structural features of the N-A-S-H gel were analyzed in terms of bond length and bond angle information, simulated X-ray diffraction (XRD) and Qn distribution. A significant finding is the existence of pentacoordinate Al in all simulated N-A-S-H structures, indicating that pentacoordinate Al in geopolymer does not only come from raw material. Besides, the results show that a smaller Si/Al ratio led to a more crosslinked and compacted structure of N-A-S-H gel
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Effects of the extraction voltage applied by the puller-electrode on the H extraction in the Linac4 negative ion source
No full textIn order to understand the H extraction mechanism and investigate the effect of the extraction voltage applied by the puller-electrode on the H extraction in the Linac4 negative ion source, we are developing a 2D3V-PIC (two dimensions in the real space and three dimensions in the velocity space, Particle in Cell) model with volume produced H ions. It is shown that how to take the magnetic filter field direction is important for the 2D modeling to take into account the important 3D effect of electron drift. It is also shown that the meniscus formation is not symmetric due to the electron drift in the extraction region and the divergence of the H beam is asymmetric. In order to make more quantitative comparison of the extracted H and electron currents with the experiments and 3D modeling, further improvements, especially the electron loss along the magnetic filter field line will be needed
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Measuring industry-science links through inventor-author relations: A profiling method
No full textIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
Electrostatic properties of C-S-H and C-A-S-H for predicting calcium and chloride adsorption
No full textThe adsorption capacity of cement hydrates considerably affects the ionic ingress into cementitious materials. In this study, the surface electrostatic properties of calcium silicate hydrate (C-S-H) and calcium aluminosilicate hydrate (C-A-S-H) were determined to understand the effects of the properties on calcium and chloride adsorption. The density of the surface functional groups was determined by analysing the structure of C-S-H and CASH through Al-27 and Si-29 MAS NMR. The surface sites of SiOH and AlOH are available in CASH whereas C-S-H has SiOH groups for ionic adsorption. We found that the incorporation of aluminium decreases the number of total adsorption sites in C-A-S-H. Furthermore, the site density increased with Ca/(Si + Al). To understand the C-A-S-H/solution interface, a triple-layer surface complexation model was developed and the associated equilibrium constants for depmtonation, calcium, and chloride adsorption were determined by fitting the experimental data of potentiometric titration and zeta potential measurement results. The estimated surface complexation modelling parameters were verified by predicting the experimental data of calcium and chloride adsorption on C-S-H and C-A-S-H
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