Numerical Simulation of Two Phase Mathematical Model for Transportation of Mass and Drug from Drug Eluting Stents

2017 ◽  
Vol 12 (5) ◽  
pp. 162-179
Author(s):  
A. Ali ◽  
N. Alias ◽  
W. Al Rahmi
2021 ◽  
Vol 81 (4) ◽  
pp. 1503-1529
Author(s):  
Sunčica Čanić ◽  
Yifan Wang ◽  
Martina Bukač

2021 ◽  
Vol 321 ◽  
pp. 04011
Author(s):  
Navideh Abbasnezhad ◽  
Farid Bakir ◽  
Stéphane Champmartin ◽  
Mohammadali Shirinbayan

Drug-eluting stents implanted in blood vessels are subject to various dynamics of blood flow. In this study, we present the evaluation of a mathematical model considering the effect of flow rate, to simulate the kinetic profiles of drug release (Diclofenac Sodium (DS)) from in-vitro from PLGA films. This model solves a set of non-linear equation for modeling simultaneously the burst, diffusion, swelling and erosion involved in the mechanisms of liberation. The release parameters depending on the flow rate are determined using the corresponding mathematical equations. For the evaluation of the proposed model, test data obtained in our laboratory are used. To quantify DS release from drug-carrier PLGA films, we used the flow-through cell apparatus in a closed-loop. Four flow rate values are applied. For each value, the model-substance liberation kinetics showed an increase in drug released with the flow rate. The simulated release profiles show good agreement with the experimental results. Therefore, the use of this model could provide a practical tool to assess in-vitro drug release profiles from polymer matrices under continuous flow rate constraint, and could help improve the design of drug eluting stents.


Author(s):  
Haroldo Rosman Junior ◽  
Rachel Manhaes de Lucena ◽  
Norberto Mangiavacchi ◽  
José da Rocha Miranda Pontes ◽  
Sean McGinty

1979 ◽  
Vol 19 (03) ◽  
pp. 175-182 ◽  
Author(s):  
Hossein Kazemi ◽  
L.S. Merrill

Original manuscript received in Society f Petroleum Engineers office Sept. 15, 1977. Paper accepted for publication June 9, 1978. Revised manuscript received Feb. 19, 1979. Paper (SPE 6890) first presented at the SPE-AIME 52nd Annual Fall Technical Conference and Exhibition, held in Denver, Oct. 9-12, 1977. Abstract A two-dimensional, two-phase, semi-implicit, numerical simulator was used to simulate water imbibition and oil recovery in artificially fractured and unfractured cores. Experimental results were matched satisfactorily by the numerical simulator. These results provide evidence of the reliability of the concepts underlying an earlier numerical simulator, which was tailored specifically for field applications. We show that the flow equations used to match the laboratory data reduce to the equations used in the field simulator. In addition, the experiments themselves were conducted quite differently from those commonly used in imbibition experiments and provide added insight into oil recovery from fractured reservoirs. Introduction Previously, we reported on the development of a Previously, we reported on the development of a numerical reservoir simulator for use in field applications. In this paper, we examine the reliability of the concepts underlying the numerical simulation by matching experimental results of fractured and unfractured cores with a simulator that accounts for the fracture and the matrix components. The simulator is a conventional two-dimensional, two-phase, semi-implicit simulator, but we show that it reduces to the formulation used in the field simulator. Several studies have reported on water imbibition in fractured media. These studies were concerned primarily with the imbibition aspects of the flow primarily with the imbibition aspects of the flow mechanism in the matrix rather than the total flow problem in the fracture-matrix system. Mattax and problem in the fracture-matrix system. Mattax and Kyte developed equations for scaling up imbibition effects. Parsons and Chaney used these equations to study imbibition effects in carbonate rocks. Iffly et al., in addition to experimental work, used a one-dimensional, two-phase, semi-implicit mathematical model to match oil recoveries from the matrix. A similar mathematical model in two dimensions was used by Kleppe and Morse to match the results of their imbibition experiments. While the last two papers show that imbibition oil recovery can be simulated numerically, the total concept of fluid flow in fracture-matrix systems has not been investigated adequately either numerically or experimentally. Mathematical Model The porous media used here were cylindrical cores or rectangular blocks cut along the long axis. The flow experiments were conducted so that the fracture plane and the entire core were horizontal. Therefore, the fractured cores were simulated by a layered two-dimensional simulator. The core halves were simulated as two matrix layers having the properties of the original core. The fracture was simulated as a very thin, high-permeability, and high-flow-capacity layer, where capillary pressure was essentially zero. The basic flow equations, assuming imcompressible flow, are w w----- wx ------ + ----- wz --------x x x zax az Sw+ qw Bw (X - Xo) = -------................(1)at t o o------ ox------ + ------ oz -------qoBo (X-Xo)x x z z So= ---------..................................(2)t Sw + So = 1.....................................(3) Pc(Sw) = po - pw....................................(4) kxkrwwx = 0.006328 -----------,......................(5)w SPEJ P. 175


Author(s):  
Vladimir Viktorovich Pekunov

This article examines the problem of numerical simulation of interaction between the gaseous sulfur dioxide emitted by road transport and fog in the conditions of high humidity. For this purpose, the author applies a multi-factor two-phase mathematical model, which takes into account the dynamics of turbulent main phase, dynamics and kinetics of the multi-sectional droplet phase, presence of thermal inconsistencies formed as a result of direct and diffused solar radiation in various ranges, diffusion of sulfur dioxide, and its absorption by the fog droplets. The article carries out a numerical calculation of the corresponding task within the modeling system of environmental processes AirEcology-P, which allows generating the optimal calculation code for a particular mathematical model. The proposed complex mathematical model that descries interaction between the emitted sulfur dioxide gas and the fog droplets is new; it specifies the calculation of the kinetics of droplet phase based on consideration of the additional factor of droplet fusion characteristic to fog. The submodel of the droplet phase was tested in the numerical simulation (the results were compared with the data of direct Lagrangian modeling of the composite of 1,000 droplets), indicating decent accuracy results. The article obtains the results of numerical simulation of interaction between the emitted SO2 and the droplets. The author demonstrates the self-cleaning ability of the atmosphere, the degree of which correlates with the initial concentration of the smallest droplets and the height from the surface.


Author(s):  
Carrie V. Falke ◽  
Abdul Khaliq ◽  
Tammy R. Dugas ◽  
James J. Kleinedler ◽  
Weizhong Dai

2014 ◽  
Vol 678 ◽  
pp. 620-623
Author(s):  
Xiao Lei Zhou ◽  
Zhe Shi ◽  
Gui Fang Zhang ◽  
Zhong Ning Du

The research status of numerical simulation on LF furnace refining ladle is introduced in this paper.Since 1970, the research on the gas-liquid two-phase region has begun.Szekely began to be simulated by mathematical model and physical experiment method of flow phenomena in ladle in early 1975. It is the first time that the numerical model is introduced to study the refining process of steel. The plume model is presented by Xiao Zeqiang in 1980, then the numerical simulation began to develop rapidly.


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