ÁFRICA EM MOVIMENTO: A HISTÓRIA E O CINEMA AFRICANO CONTEMPORÂNEO

Esse artigo deriva de algumas reflexões sobre o papel do cinema africano na desconstrução do chamado racismo científico, que perdurou até a década de 50 do século passado. Tem como propósito discutir a relação entre cinema e história, destacando a contribuição da produção fílmica para a construção das identidades nacionais. Nessa perspectiva, coloca em questão o cinema africano contemporâneo e a sua importância na luta pela afirmação política e cultural dos povos africanos e da própria história do continente.PALAVRAS-CHAVE: cinema africano contemporâneo; história; cinema; cultura africana

Effect of slag composition on iron nuggets formation from carbon composite pellets

Iron-carbon nuggets can be obtained by high temperature reduction of iron ore by carbonaceous material when both are agglomerated together as a carbon composite pellet. During this process, the stable oxides contained in the materials will form a slag. This work investigates the effect of this slag composition on iron nugget formation. Pellets were prepared with iron ore and two different carbonaceous materials. Through the addition of Portland® cement, silica and alumina the slag composition was varied to adjust the expected liquidus temperature to 1573 and 2273 K. It has been shown that the formation of iron nuggets is favored for slags presenting low liquidus temperature. In order to further investigate this phenomenon, pellets containing iron powder and carbonaceous material, together with previously prepared slags, were also submitted to high temperature, and it has been shown that iron carburization depends on slag composition.(FAPESP) São Paulo Research FoundationNational Research and Development Council of Brazil (CNPq

Modelamento matemático e simulação do comportamento do nitrogênio no processo de desgaseificação a vácuo com circulação

Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorEste trabalho aborda o modelamento matemático e simulação do comportamento do nitrogênio durante o período de tratamento do aço líquido no desgaseificador RH e RH-KTB. A remoção do nitrogênio é descrita cineticamente pelo modelo de controle misto. As etapas consideradas no modelo de controle misto são o transporte de massa do nitrogênio no metal e a reação na interface metal-gás. O modelo descreve a remoção do nitrogênio de forma global, não diferenciando a contribuição individual de cada um dos sítios de reação no RH. Quando ocorre a descarburação sob vácuo é assumido que o nitrogênio e o carbono reagem nos mesmos sítios. Assim, os parâmetros cinéticas aplicáveis a descrição da remoção do nitrogênio são obtidos através do conhecimento do processo de remoção do carbono. Neste modelo também é analisado o efeito do vazamento de ar atmosférico para o interior do desgaseificador, tendo em vista que a vedação destes equipamentos não é perfeita para evitar o vazamento. Desta forma, é simulado o vazamento do ar atmosférico em diferentes pontos dos desgaseificadores RH e RH-KTB e como esse efeito atua sobre o comportamento do nitrogênio do aço líquido durante o período de tratamento de descarburação e desoxidação

Sensoriamento remoto aplicado na espacialização de esquistossomose no sul-sudoeste do Estado de Minas Gerais

The schistosomiasis is a serious disease that is considered endemic in fifty-four countries located in the American and African continents. It is estimated that in Brazil the number of people infected by S. mansoni vary among 2,5 to 6 million of peoples. In this context, this study shows the spatial distribution of schistosomiasis in two localities (Guaranésia and Arceburgo) placed in the south of State of Minas Gerais. The spatial analysis were performed based in remote sensing data, and involved: a) the land cover mapping based in Landsat-5/TM images; b) hypsometric mapping based in Digital Elevation Model from SRTM (Shuttle Radar Topography Mission); c) drainage network mapping obtained by topographic charts from IBGE and; d) density mapping of the snails found in the study area by Kernel Estimation. To identify the human cases of schistosomiasis the Kato-Katz and Lutz/HPJ methods for diagnosis was performed. The results show the presence of snails in the study area. Fieldwork realized in 2012 indicated six focus of B. tenagophila, totaling 681 snails that were no infected. The diagnosis in the human reveals the prevalence rate for Guaranésia and Arcerburgo of approximately 13,5% for a total of 480 tests. In 13,5%, 32% were infected with S. mansoni. The spatial analysis considering land cover, drainage network, hypsometric, density of snails and infected cases in humans indicated risk of transmission in Arceburgo, where the snails are concentrated. A case of infected person was noticed in rural zone.Pages: 8606-861

Greenhouse gas emissions associated with traditional and alternative concretes

Life Cycle Assessment (LCA) quantifies the environmental impacts associated with products throughout their life cycle. LCA also assists in the interpretation of impact assessment results, enabling improvements in a product or process. This paper applied the LCA methodology to quantify and compare the greenhouse gas emissions associated with different types of concrete: with a traditional binder (Portland cement) and with alkali-activated materials (Metakaolin, Lateritic Soil, and Lateritic Concretion) as precursors. The environmental impact was evaluated by means of greenhouse gas emissions (kg CO2-eq/m³), considering 1m³ of each binder and resistance of approximately 30 MPa, obtained by a recommended mix ratio. The main objective is to evaluate whether alkali-activated binders present lower emissions than Portland cement. The results demonstrated that Portland cement is responsible for over 92% of the environmental impacts of traditional concrete production. The use of alternative materials in civil construction, such as laterite soil, reduces carbon dioxide emissions by 79% compared to Portland cement concrete emissions

Greenhouse gas emissions associated with traditional and alternative concretes

Life Cycle Assessment (LCA) quantifies the environmental impacts associated with products throughout their life cycle. LCA also assists in the interpretation of impact assessment results, enabling improvements in a product or process. This paper applied the LCA methodology to quantify and compare the greenhouse gas emissions associated with different types of concrete: with a traditional binder (Portland cement) and with alkali-activated materials (Metakaolin, Lateritic Soil, and Lateritic Concretion) as precursors. The environmental impact was evaluated by means of greenhouse gas emissions (kg CO2-eq/m³), considering 1m³ of each binder and resistance of approximately 30 MPa, obtained by a recommended mix ratio. The main objective is to evaluate whether alkali-activated binders present lower emissions than Portland cement. The results demonstrated that Portland cement is responsible for over 92% of the environmental impacts of traditional concrete production. The use of alternative materials in civil construction, such as laterite soil, reduces carbon dioxide emissions by 79% compared to Portland cement concrete emissions.</p

Measurement of the double-differential inclusive jet cross section in proton-proton collisions at s\sqrt{s} = 5.02 TeV

International audienceThe inclusive jet cross section is measured as a function of jet transverse momentum $p_\mathrm{T}$ and rapidity $y$. The measurement is performed using proton-proton collision data at $\sqrt{s}$ = 5.02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb$^{-1}$. The jets are reconstructed with the anti-$k_\mathrm{T}$ algorithm using a distance parameter of $R$ = 0.4, within the rapidity interval $\lvert y\rvert$$\lt$ 2, and across the kinematic range 0.06 $\lt$$p_\mathrm{T}$$\lt$ 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonperturbative effects, and presented for a variety of parton distribution functions and choices of the renormalization/factorization scales and the strong coupling $\alpha_\mathrm{S}$

Two-particle Bose-Einstein correlations and their Lévy parameters in PbPb collisions at sNN\sqrt{s_\mathrm{NN}} = 5.02 TeV

Two-particle Bose-Einstein momentum correlation functions are studied for charged-hadron pairs in lead-lead collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV. The data sample, containing 4.27$\times10^{9}$ minimum bias events corresponding to an integrated luminosity of 0.607 nb$^{-1}$, was collected by the CMS experiment in 2018. The experimental results are discussed in terms of a L\'evy-type source distribution. The parameters of this distribution are extracted as functions of particle pair average transverse mass and collision centrality. These parameters include the L\'evy index or shape parameter ($\alpha$), the L\'evy scale parameter ($R$), and the correlation strength parameter ($\lambda$). The source shape, characterized by $\alpha$, is found to be neither Cauchy nor Gaussian, implying the need for a full L\'evy analysis. Similarly to what was previously found for systems characterized by Gaussian source radii, a hydrodynamical scaling is observed for the L\'evy $R$ parameter. The $\lambda$ parameter is studied in terms of the core-halo model.Comment: Submitted to Physical Review C. All figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-21-011 (CMS Public Pages