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Preparation and Characterization of Chitosan-Insulin-Tripolyphosphate Membrane for Controlled Drug Release: Effect of Cross Linking Agent

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Journal of Biomaterials and Nanobiotechnology 2014年第4期5卷 211-219页

作者： Holanda Adriana Lima Fook Marcus Vinícius Lia swarnakar ramdayal Department of Physiotherapy Centre for Higher Education and Development Faculty of Medical Sciences of Campina Grande Campina Grande Brazil Department of Materials Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil Department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil

The term Diabetes Mellitus (DM) comprises a group of metabolic disorders characterized by chronic hyperglycemia resulting from defects in the secretion and/or action of insulin. The Insulin therapy constitutes the preferred treatment for DM, consisting of daily subcutaneous insulin injections to control blood glucose levels. The chitosan studied for Biomedicine is a biomaterial that can be used for controlled release of drugs whose release rate can be controlled by Sodium Tripolyphosphate (TPP), which is an ionic cross linker of the chitosan. Present study, therefore, was aimed to develop and evaluate membranes of chitosan and chitosan cross linked by TPP for use in controlled release of insulin system, with the purpose of obtaining an alternative to the injectable administration of this drug. The developed membranes were characterized by the techniques of Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), High Performance Liquid Chromatography (HPLC) and Evaluation of Cell Viability of Macrophages (MTT). With the FTIR technique the interaction between chitosan, tripolyphosphate and insulin was identified. Chemical elements present in chitosan, insulin and sodium tripolyphosphate membranes were detected by EDX technique. By SEM technique, the changes in the morphology of the membrane containing insulin, with the presence of granular particles of varying sizes, could be observed when compared to pure chitosan. With HPLC assay insulin was identified and it was shown that it gets separated from chitosan membrane even when the membrane was cross linked by the TPP, though at a reduced rate. The crosslinking agent was effective to control the rate of insulin release. The biocompatibility of the prepared membranes was confirmed by cell viability of macrophages using the MTT assay. The developed membranes, therefore, have potential for use as a biomaterial in controlled release systems for insulin.

关键词： Biomaterials Diabetes Mellitus Insulin-Chitosan-TPP Membranes Controlled Release of Drugs

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Thermo-Hydrodynamics of Core-Annular Flow of Water, Heavy Oil and Air Using CFX

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Advances in Chemical Engineering and Science 2013年第4期3卷 37-45页

作者： Antonio José Ferreira Gadelha Severino Rodrigues de Farias Neto ramdayal swarnakar Antonio Gilson Barbosa de Lima Department of Chemical Engineering Center of Science and Technology Federal University of Campina Grande

The transport of heavy and ultra-viscous oil employing the core-flow technique has been increasing recently, because it provides a greater reduction of the pressure drop during the flow. In this context, the effect of temperature and the presence of gas on the thermo-hydrodynamics of a three-phase water-heavy oil-air flow in a horizontal pipe under the influence of gravity and drag forces, using the commercial software ANSYS CFX?, have been evaluated. The standard κ ? ε turbulence model, the mixture model for heavy oil-water system and the particle model for heavy oil-gas and water-gas systems, were adopted. Results of velocity, volume fraction, pressure and temperature fields of the phases present along the pipe are presented and discussed. It has been found that the presence of the air phase and the variation in the temperature affect the behavior of annular flow and pressure drop.

关键词： Heavy Oil Three-Phase Flow Heat Numerical Simulation CFX

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Unsteady Fluidynamic Behavior of Gas Bubbles Flowing in Curved Pipes: A Numerical Study

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Advances in Chemical Engineering and Science 2012年第2期2卷 283-291页

作者： Jose Luis Gomes Marinho ramdayal swarnakar Severino Rodrigues de Farias Neto Antonio Gilson Barbosa de Lima Department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil Department of Mechanical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil

Petroleum is considered as one of the factors for the development of a nation as well as a cause of economic and political conflicts around the world because of the diversity of products obtained with their derivatives such as fuel for automotives and aviation, and manufacturing plastic parts, among others. The crude petroleum (usually oil, water and gas) found in an underground reservoir is transported to the surface by pipes, and has drawn the attention of researchers because of the problems generated in the pipeline with particular attention to the loss of pressure, friction and bubbles. For a fluid flow in plug regime, where many of the bubbles formed coalesce and produce bigger ones of sizes almost equal to the pipe diameter (Taylor bubble), severe instability in the flow is caused. In this context, the objective of this research has been to study the Taylor bubble flow in curved ducts using the software CFX. Results of the transient effects of the air concentration on the bubble air volumetric fraction, of the viscosity on bubble format, and pipe angle of 90? on bubble symmetry are presented and interpreted.

关键词： Slug Flow Taylor Bubbles Curved Pipe CFD Oil Simulation

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Non-Isothermal Separation Process of Two-Phase Mixture Water/Ultra-Viscous Heavy Oil by Hydrocyclone

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Advances in Chemical Engineering and Science 2011年第4期1卷 271-279页

作者： Josedite Saraiva de Souza Fabiana Pimentel Macêdo Farias ramdayal swarnakar Severino Rodrigues de Farias Neto Antonio Gilson Barbos de Lima 不详

Environmental agencies do not allow effluents, from the petroleum productions, which contain oil concentrations that exceed the amounts permitted by the regulations. In recent time heavy oil operating petroleum industries are generating oil/water mixture by products, which are difficult to separate. Industrially, hydrocyclone is generally used to separate oil from an oil/water mixture. This is due to its high performance of separation, low cost of installation and maintenance. In the present work, therefore, the thermal fluid dynamics of water/ultra-viscous heavy oil separation process in a hydrocyclone has been studied. A steady state mathematical model which simulates the performance of a non-isothermal separation process is presented. The Eulerian-Eulerian approach for the interface of the phases involved (water/ultra-viscous heavy-oil) is used and the two-phase flow is considered as incompressible, viscous and turbulent. For carrying out numerical solutions of the governing equations the CFX11? commercial code was used. Results of the behavior of the two-fluid flow inside the hydrocyclone and separation efficiency are presented and analyzed. The role of the average temperature of the fluid, oil droplet diameter and the fluid mixture inlet velocity on the separation efficiency of the hydrocyclone are verified.

关键词： Thermal Fluid Dynamics Hydrocyclone Two-Phase Flow Simulation Separation Efficiency

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