In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Microwave Inactivation of Bacteria Under Dynamic Heating Conditions in Solid Media

S. Curet[1], M. Mazen Hamoud-Agha[1]
[1]GEPEA, UMR 6144, CNRS, ONIRIS, Université de Nantes, Nantes, France

In this study, COMSOL®4.2a is used to model a microwave heating process in a TE10 rectangular waveguide. The sample consists of a small cylindrical Ca-alginate gel (D = 8 mm, H = 10 mm) inoculated with bacteria Escherichia Coli K12. The sample is placed along the microwave propagation direction into the waveguide. Maxwell’s equations and heat transfer are coupled to a microbial inactivation ...

Modeling of an Oxygenation-Aided 3D Culture for Functional Beta-Cell Expansion

S. Jin[1], J. McReynolds[1], X. Li[2], J. Guan[2]
[1]Department of Biomedical Engineering, College of Engineering, University of Arkansas, Fayetteville, AR, USA
[2]Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA

Currently, researchers are looking for ways to mass-produce biologically functional pancreatic beta cells in vitro because of the shortage of donor tissue needed for diabetes cell therapy. The beta cells will become hypoxic if their high oxygen demands are not met. We hypothesized that the biological function of beta cells can be improved if they are cultured in a 3D collagen scaffold, which ...

Aplicação de Elementos Finitos na Ortodontia

T. O. Bassani [1], T. Bassani [2], A. Andriguetto [1], F. Schneider [2],
[1] Instituto Latino Americano de Pesquisa e Ensino Odontológico - ILAPEO, Curitiba, PR, Brasil
[2] Universidade Tecnológica Federal do Paraná – UTFPR, Curitiba, PR, Brasil

O presente estudo visou a avaliação, por meio do método dos elementos finitos, das tensões geradas em um arco ortodôntico chamado de Arco de Retração Dupla Chave, também conhecido como DKL. Para isso foram modeladas as geometrias do arco DKL, dos bráquets e das coroas dentais, no software COMSOL Multiphysics®. O modelo criado tem como objetivo a substituição dos métodos tradicionais de ...

Modeling of Nerve Stimulation Thresholds and Their Dependence on Electrical Impedance with COMSOL

P. Krastev[1], and B. Tracey[1]
[1]Neurometrix, Inc., Waltham, Massachusetts, USA

Nerve localization is important for applications in regional anesthesia. Localization is achieved by stimulating the nerve with an electric field produced by a current from a needle inserted into the body of the patient, close to the target nerve.  Modeling of the electric field in close proximity to the nerve may help to explain observed variations in threshold currents and can help to ...

Simulation of Transport of Lipophilic Compounds in Complex Cell Geometry

Q.A. Chaudhry[1], M. Hanke[1], and R. Morgenstern[2]
[1]School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden
[2]Karolinska Institutet, Stockholm, Sweden

The mathematical modeling of the diffusion and reaction of toxic compounds in mammalian cells is tough task due to their very complex geometry. The heterogeneity of the cell, particularly the cytoplasm, and the variation of the cellular architecture, greatly affects the behavior of these toxic compounds. Homogenization techniques have been implemented for the numerical treatment of the model. ...

Simulation of Convection in Water Phantom Induced by Periodic Radiation Heating

H.H. Chen-Mayer[1], and R. Tosh[1]
[1]Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA

Water calorimetry is employed to establish a primary reference standard for radiation dosimetry by measuring the temperature rises in a water phantom (a cube of about 30 cm x 30 cm x 30 cm) subjected to a beam of ionizing radiation.  We use COMSOL Multiphysics to model the system using the Heat Transfer module and the Incompressible Navier-Stokes module with a geometry of 2D-axial ...

Detection of E.coli Cell using Capacitance Modulation

A.K. Dwivedi, R.M. Patrikar, R.B. Deshmukh, and G. Pendharkar
Visvesvaraya National Institute of Technology, Nagpur, Maharashtra, India

Testing and verification is very important to increase reliability of a system. In water analysis its purity is verified using different test methods. Biosensors are very useful to detect the microorganisms present in water. This paper presents a method to detect E.coli bacteria in water depending upon the capacitance modulation in the presence and absence of E.coli cell, which is simulated in ...

Simulation and Design of a Microfluidic Respirometer for Semi-Continuous Amperometric Short Time Biochemical Oxygen Demand (BODST) Analysis

F.J. del Campo[1], A. Torrents[1], J. Mas[2], F.X. Muñoz[1]
[1]Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Campus Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
[2]Departement de Genètica i Microbiologia, Campus Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain

Introduction: This work presents the design of a novel flow cell based miniaturized electrochemical respirometer to monitor organic content in water samples semi-continuously, in contrast to current Biochemical Oxygen Demand, BOD, methods. Simulation techniques has been used to parameterize and optimize aspects such as height and length of the channels, materials and thickness, flow and oxygen ...

An Assessment of the Suitability of the Body and Adult Head Coils for Transmission during Paediatric Magnetic Resonance Imaging

G.R. Cook[1], M.J. Graves[1], F.J. Robb[2], D.J. Lomas[1]
[1]Department of Radiology, University of Cambridge, Cambridge, United Kingdom
[2]General Electric Healthcare Coils, Aurora, Ohio, USA

MRI offers many advantages over other modalities and its lack of ionizing radiation is important for children, but can be limited by the radio-frequency (RF) coils available. This work calculates Specific Absorption Rate (SAR) and homogeneity of the RF transmit field (B1+) when imaging infants in adult coils. Two birdcage-type coils were loaded by a tissue model and their B1+ homogeneities ...

基于 DTI 纤维追踪和有限元力学模型的脑损伤轴突纤维损伤研究

李娜 [1], 李江红 [2]
[1] 中南大学湘雅三医院,长沙,湖南,中国
[2] 中车集团南车研究所,株洲,湖南,中国

研究头部损伤机理是对运动撞击中脑损伤进行预测的有效手段。数学模型是分析损伤实验数据、预测人员碰撞损伤程度的唯一方法,但现有的头部损伤有限元模型基于尸体实验数据,且忽略脑组织结构的各向异性。本项目旨在提出并实现一种以损伤生物力学为基础、结合磁共振扫描 DTI 的轴突走向信息的有限元力学模型。提取脑外伤前的弥散张量成像信息,实现深入到轴突水平有限元力学模型的建立,在有限元模拟中采用非线性超弹性力学模型,并植入 NSGAII 最优化方法对有限元模型的材料参数进行优化,从而提高模型的稳定性和计算精度;将计算预测结果与损伤后 DTI 的 FA 值所表现的轴突断裂情况进行验证, 探索活体环境下碰撞损伤中脑轴突的损伤性变化,从而获得脑外伤损伤程度与力学因素之间的关系,为脑外伤损伤程度的预测和脑外伤损伤标准的校正提供精确完整的信息。本项目的研究成果将在汽车碰撞的乘员防护设计上有重要的理论指导价值。 ...