Examinando por Materia "Surface chemistry"

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    Ítem
    Analysis of chemical processes for the synthesis of magnetite for biomedical applications
    (IOP PUBLISHING LTD, 2011-01-01) Baena, J.; Marulanda, J.I.; Universidad EAFIT. Departamento de Ciencias Básicas; Óptica Aplicada
    This article demonstrates the evaluation of wet chemical routes to produce magnetic nanoparticles of iron oxide and surface chemistry characterization by infrared spectroscopy (IR). Its potential use in biomedicine as contrast agents or to deliver drugs in localized medical treatments, which reduce the toxicity associated with cytotoxic drugs, is also evaluated.
  • No hay miniatura disponible
    Ítem
    Analysis of chemical processes for the synthesis of magnetite for biomedical applications
    (IOP PUBLISHING LTD, 2011-01-01) Baena, J.; Marulanda, J.I.; Baena, J.; Marulanda, J.I.; Universidad EAFIT. Departamento de Ciencias; Electromagnetismo Aplicado (Gema)
    This article demonstrates the evaluation of wet chemical routes to produce magnetic nanoparticles of iron oxide and surface chemistry characterization by infrared spectroscopy (IR). Its potential use in biomedicine as contrast agents or to deliver drugs in localized medical treatments, which reduce the toxicity associated with cytotoxic drugs, is also evaluated.
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    Ítem
    Design and construction of a transducer for bite force registration.
    (ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería Mecánica; Bioingeniería GIB (CES – EAFIT)
    This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.
  • No hay miniatura disponible
    Ítem
    Design and construction of a transducer for bite force registration.
    (ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)
    This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.
  • No hay miniatura disponible
    Ítem
    Simulation and parameterization by the finite element method of a C Shape Delectromagnet for application in the characterization of magnetic properties of materials
    (World Academy of Science, Engineering and Technology, 2012-11-22) Velásquez Torres, Álvaro Andrés; Baena Rodríguez, Juliana; Universidad EAFIT. Departamento de Ciencias Básicas; avelas26@eafit.edu.co; Electromagnetismo Aplicado (Gema)
    This article presents the simulation, parameterization and optimization of an electromagnet with the C–shaped configuration, intended for the study of magnetic properties of materials -- The electromagnet studied consists of a C-shaped yoke, which provides self–shielding for minimizing losses of magnetic flux density, two poles of high magnetic permeability and power coils wound on the poles -- The main physical variable studied was the static magnetic flux density in a column within the gap between the poles, with 4cm2 of square cross section and a length of 5cm, seeking a suitable set of parameters that allow us to achieve a uniform magnetic flux density of 1x104 Gaussor values above this in the column, when the system operates at room temperature and with a current consumption not exceeding 5A -- By means of a magnetostatic analysis by the finite element method, the magnetic flux density and the distribution of the magnetic field lines were visualized and quantified -- From the results obtained by simulating an initial configuration of electromagnet, a structural optimization of the geometry of the adjustable caps for the ends of the poles was performed -- The magnetic permeability effect of the soft magnetic materials used in the poles system, such as low–carbon steel (0.08% C), Permalloy (45% Ni, 54.7% Fe) and Mumetal (21.2% Fe, 78.5% Ni), was also evaluated -- The intensity and uniformity of the magnetic field in the gap showed a high dependence with the factors described above -- The magnetic field achieved in the column was uniform and its magnitude ranged between 1.5x104 Gauss and 1.9x104 Gauss according to the material of the pole used, with the possibility of increasing the magnetic field by choosing a suitable geometry of the cap, introducing a cooling system for the coils and adjusting the spacing between the poles -- This makes the device a versatile and scalable tool to generate the magnetic field necessary to perform magnetic characterization of materials by techniques such as vibrating sample magnetometry (VSM), Hall-effect, Kerr-effect magnetometry, among others -- Additionally, a CAD design of the modules of the electromagnet is presented in order to facilitate the construction and scaling of the physical device