EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Item A novel two degrees of freedom system for measuring iron ore water content on a conveyor belt.(2021) Pinto, Érica Silva; Santos, Gabriel Almeida; Magalhães, Paulo Henrique Vieira; Rêgo Segundo, Alan KardekWater content or moisture of materials is a parameter widely used in the industry. In mining, it is an important variable to control in iron ore production. High moistures may cause instability of iron ore piles and may make transport by ship unfeasible. Therefore, this paper presents the development of a system for measuring iron ore moisture on a conveyor belt (laboratory-scale). The structure that supports the sensor has two degrees of freedom, which allow perpendicular and parallel movements. The parallel movement makes the relative velocity between the measurement cell and the ore almost zero. The vertical movement allows the sensor to be placed at different depths in the ore. These sets enable real-time and in situ measurements. The system uses the capacitive method to determine the dielectric constant of the iron ore located between the sensor electrodes and, consequently, the moisture. This system has a measuring range of 0 to 14% on a dry basis and presents an uncertainty up to 0.07 percentage points for a 2-standard-deviation confidence level. In the validation process, the absolute error was less than 0.34 percentage point in the mining interest range of 6 to 14%. The founded results achieve a significant advance in the development of real-time equipment for measuring ore moisture since there is no device capable of doing it with the necessary level of accuracy and precision. For mining, this kind of system represents a big step to take corrective and preventive decisions around iron ore moisture control.Item The golden mussel proteome and its response to niclosamide : uncovering rational targets for control or elimination.(2020) Sanson, Ananda Lima; Cosenza Contreras, Miguel de Jesus; Marco, Ricardo De; Neves, Leandro Xavier; Mattei, Bruno; Silva, Gustavo Gonçalves; Magalhães, Paulo Henrique Vieira; Andrade, Milton Hércules Guerra de; Borges, William de CastroThe Asian invasive species Limnoperna fortunei (Dunker, 1857), known as the golden mussel, causes great economic and environmental damage due to its fixative capacity and accelerated proliferation. Molecular studies for the control of larval and adult forms are of great economic, scientific and technological interest. Here, we first report on the compositional analysis of the L. fortunei proteome obtained through shotgun analysis using LC-MS/ MS. Among those 2790 proteins identified, many of them related to secretory processes and membrane receptors. Our second approach consisted in exposing the mollusc to the molluscicide niclosamide to evaluate the induced proteomic alterations. Exposure to niclosamide at 0.25 mg/L for 24 h resulted in a pronounced differential abundance of proteins when compared to those obtained when exposure was reduced to 4 h at 2.3 mg/ L. In total, 342 proteins were found differentially expressed in the responsive individuals as revealed by labelfree quantitative proteomics. Regarding the affected cell processes were: cell division and differentiation, cytoskeletal organization and compartment acidification (upregulated), and energy metabolism (downregulated). Our findings constitute the first inventory of the expressed proteome of the golden mussel and have the potential to contribute with a more rational proposition of molecular targets for control and monitoring of this species. Significance: With the recent availability of transcriptomic and genomic data applied to L. fortunei the timing is right to interrogate its putative gene repertoire using proteomic techniques. These have the potential to validate the existence of the predicted genes, infer their relative abundance and quantify their levels as a response to environmental stressors or various agents. Here we provided an inventory of the golden mussel proteome and evaluated its response to the molluscicide niclosamide. The obtained results open new avenues for intervention aimed at its control or elimination, particularly by targeting the various cellular processes that were uncovered.Item Estudo de um veículo submersível para uso em inspeção de estruturas hidráulicas.(2008) Martinez, Carlos Barreira; Magalhães, Paulo Henrique Vieira; Bastos, Alexandre Augusto Marinho da Motta; Gruberger, IsaakA inspeção visual de estruturas hidráulicas é uma atividade para a qual, normalmente, designam-se seres humanos treinados capazes de gerar opiniões sobre o item inspecionado. Entretanto, devido à diversidade de condições, as dificuldades inerentes ao trabalho subaquático e a segurança do pessoal envolvido nestas inspeções, tornam esta tarefa um problema de gerenciamento complexo. Devido a este fato e visando propiciar melhores condições de trabalho, propõe-se a utilização de sistemas de monitoramento remoto através de câmera e sensores dos mais diversos tipos. Motivado por estas questões, elaborou- se o projeto e o protótipo de um veículo de inspeções subaquático que se tem como objetivo principal, permitir o estudo de uma solução viável e efetiva no quesito “eliminar riscos e prover melhores condições de trabalho”. O veículo consiste em um sistema móvel telecomandado capaz de captar imagens e transmiti-las via cabo para um ponto distante permitindo seu posterior armazenamento e análise. O veículo desenvolvido para testes foi concebido com o objetivo inicial de permitir a formação de conhecimento básico sobre o problema. Assim, enfocou-se no primeiro protótipo os problemas relativos a flutuabilidade, capacidade de manobra, sistemas de refrigeração interna e sistemas de vídeo. O projeto do “Veículo Subaquático de Inspeção” foi denominado de“VSI-01”.Item The corrosive power of golden mussel (L. fortunei) macrofouling on steel structuresg.(2014) Cassino, Flávio Sandro Lays; Magalhães, Paulo Henrique Vieira; Trindade, Vicente Braz; Ananias, JúniaAbstract In this study it was performed a detailed morphological-structural analysis of the corrosion products resulting from golden mussel (Limnoperna fortunei) macrofouling on steel structures. Scanning electron microscopy, without previous metallization of the observed structures, was utilized in the study. With this analysis it was possible to build a new scenario for understanding this corrosion process, as several important facts were observed. Firstly, the presence of at least three types of bacteria able to corrode metals was detected: sulphate reducing bacteria, iron-depositing bacteria, and Fe3+ reducing anaerobic bacteria which produce ferrous hydroxy carbonate from magnetite. The presence and proliferation of colonies of these micro-organisms can be in many ways favored by the dense mussel fouling. Also, the analysis of the cross-sectional structure of the corrosion layer allowed identifying the basic mechanism by which the metal is consumed by the corrosion process.