Toward large-scale CVD graphene growth by enhancing reaction kinetics via an efficient interdiffusion mediator and mechanism study utilizing CFD simulations

Computational fluid dynamics (CFD) simulations were performed for unsteady periodic breathing conditions, using large-scale models of the human lung airway. The computational domain included fully coupled representations of the orotracheal region and large conducting zone up to generation four (G4) obtained from patient-specific CT data, and the small conducting zone (to G16) obtained from a stochastically generated airway tree with statistically realistic geometrical characteristics. A reduced-order geometry was used, in which several airway branches in each generation were truncated, and only select flow paths were retained to G16. The inlet and outlet flow boundaries corresponded to the oronasal opening (superior), the inlet/outlet planes in terminal bronchioles (distal), and the unresolved airway boundaries arising from the truncation procedure (intermediate). The cyclic flow was specified according to the predicted ventilation patterns for a healthy adult male at three different activity levels, supplied by the whole-body modeling software HumMod. The CFD simulations were performed using Ansys FLUENT. The mass flow distribution at the distal boundaries was prescribed using a previously documented methodology, in which the percentage of the total flow for each boundary was first determined from a steady-state simulation with an applied flow rate equal to the average during the inhalation phase of the breathing cycle. The distal pressure boundary conditions for the steady-state simulation were set using a stochastic coupling procedure to ensure physiologically realistic flow conditions. The results show that: 1) physiologically realistic flow is obtained in the model, in terms of cyclic mass conservation and approximately uniform pressure distribution in the distal airways; 2) the predicted alveolar pressure is in good agreement with previously documented values; and 3) the use of reduced-order geometry modeling allows accurate and efficient simulation of large-scale breathing lung flow, provided care is taken to use a physiologically realistic geometry and to properly address the unsteady boundary conditions.

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Large-Scale Simulation of the Clocking Impact of 2D Combustor Profile on a Two Stage High Pressure Turbine

Volume 5B: Heat Transfer ◽

10.1115/gt2014-25883 ◽

2014 ◽

Author(s):

Thomas E. Dyson ◽

David B. Helmer ◽

James A. Tallman

Keyword(s):

High Pressure ◽

Large Scale ◽

High Pressure Turbine ◽

Cfd Simulations ◽

Two Stage ◽

Substantial Impact ◽

Sliding Mesh ◽

Wall Flow ◽

End Wall ◽

Film Flows

This paper presents sliding-mesh unsteady CFD simulations of high-pressure turbine sections of a modern aviation engine in an extension of previously presented work [1]. The simulation included both the first and second stages of a two-stage high-pressure turbine. Half-wheel domains were used, with source terms representing purge and film flows. The end-wall flow-path cavities were incorporated in the domain to a limited extent. The passage-to-passage variation in thermal predictions was compared for a 1D and 2D turbine inlet boundary condition. Substantial impact was observed on both first and second stage vanes despite the mixing from the first stage blade. Qualitative and quantitative differences in surface temperature distributions were observed due to different ratios between airfoil counts in the two domains.

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Abstract 262: Derivation of Duchenne Muscular Dystrophy Disease Specific Cardiomyocytes From Patient Urine

Circulation Research ◽

10.1161/res.113.suppl_1.a262 ◽

2013 ◽

Vol 113 (suppl_1) ◽

Author(s):

Xuan Guan ◽

David L Mack ◽

Claudia M Moreno ◽

Fernando Santana ◽

Charles E Murry ◽

...

Keyword(s):

Stem Cells ◽

Human Urine ◽

Large Scale ◽

Lentiviral Vector ◽

Cellular Reprogramming ◽

Urine Samples ◽

Pcr Analysis ◽

Scale Production ◽

Mechanism Study

Introduction: Human somatic cells can be reprogrammed into primitive stem cells, termed induced pluripotent stem cells (iPSCs). These iPSCs can be extensively expanded in vitro and differentiated into multiple functional cell types, enabling faithful preservation of individual’s genotype and large scale production of disease targeted cellular components. These unique cellular reagents thus hold tremendous potential in disease mechanism study, drugs screening and cell replacement therapy. Due to the genetic mutation of the protein dystrophin, many DMD patients develop fatal cardiomyopathy with no effective treatment. The underlying pathogenesis has not been fully elucidated. Hypothesis: We tested the hypothesis that iPSCs could be generated from DMD patients’ urine samples and differentiated into cardiomyocytes, recapitulating the dystrophic phenotype. Methods: iPSCs generation was achieved by introducing a lentiviral vector expressing Oct4, Sox2, c-Myc and Klf4 into cells derived from patient’s (n=1) and healthy volunteers’ (n=3) urine. Cardiomyocytes were derived by sequentially treating iPSCs with GSK3 inhibitor CHIR99021 and Wnt inhibitor IWP4. Differentiated cardiomyocytes were subjected to calcium imaging, electrophysiology recording, Polymerase Chain Reaction (PCR) analysis, and immunostaining. Results: iPSCs were efficiently generated from human urine samples and further forced to differentiate into contracting cardiomyocytes. PCR analysis and immunostaining confirmed the expression of a panel of cardiac markers. Both normal and patient iPSC derived cardiomyocytes exhibited spontaneous and field stimulated calcium transients (up to 2Hz), as well as action potentials with ventricular-like and nodal-like characteristics. Anti-dystrophin antibodies stained normal iPSC-derived cardiomyocyte membranes but did not react against DMD iPSC-derived cardiomyocytes. Conclusions: Cardiomyocytes can be efficiently generated from human urine, through the cellular reprogramming technology. DMD cardiomyocytes retained the patient’s genetic information and manifested a dystrophin-null phenotype. Functional assessments are underway to determine differences that may exist between genotypes.

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An Approach for Efficient CFD Simulations of an Ejector Air Injection System for Active Aerodynamic Compressor Stabilization

Volume 2B: Turbomachinery ◽

10.1115/gt2017-64660 ◽

2017 ◽

Cited By ~ 1

Author(s):

Sebastian Brehm ◽

Felix Kern ◽

Jonas Raub ◽

Reinhard Niehuis

Keyword(s):

Large Scale ◽

Armed Forces ◽

Air Injection ◽

Injection System ◽

Cfd Simulations ◽

Data Set ◽

Numerical Effort ◽

Enhance Efficiency ◽

Set Up ◽

Novel Concept

The Institute of Jet Propulsion at the University of the German Federal Armed Forces Munich has developed and patented a novel concept of air injection systems for active aerodynamic stabilization of turbo compressors. This so-called Ejector Injection System (EIS) utilizes the ejector effect to enhance efficiency and impact of the aerodynamic stabilization of the Larzac 04 two-spool turbofan engine’s LPC. The EIS design manufactured recently has been subject to CFD and experimental pre-investigations in which the expected ejector effect performance has been proven and the CFD set-up has been validated. Subsequently, optimization of the EIS ejector geometry comes into focus in order to enhance its performance. In this context, CFD parameter studies on the influence of in total 16 geometric and several aerodynamic parameters on the ejector effect are required. However, the existing and validated CFD set-up of the EIS comprises not only the mainly axisymmetric ejector geometry but also the highly complex 3D supply components upstream of the ejector geometry. This is hindering large scale CFD parameter studies due to the numerical effort required for these full 3D CFD simulations. Therefore, an approach to exploit the overall axissymmetry of the ejector geometry is presented within this paper which reduces the numerical effort required for CFD simulations of the EIS by more than 90%. This approach is verified by means of both experimental results as well as CFD predictions of the full 3D set-up. The comprehensive verification data set contains wall pressure distributions and the mass flow rates involved at various Aerodynamic Operating Points (AOP). Furthermore, limitations of the approach are revealed concerning its suitability e.g. to judge the response of the attached compressor of future EIS designs concerning aerodynamic stability or cyclic loading.

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Large-Scale Automated Identification and Quality Control of Exfoliated and CVD Graphene via Image Processing Technique

ECS Transactions ◽

10.1149/1.3485619 ◽

2019 ◽

Vol 33 (13) ◽

pp. 201-209 ◽

Cited By ~ 2

Author(s):

Craig M. Nolen ◽

Desalegne Teweldebrhan ◽

Giovanni Denina ◽

Bir Bhanu ◽

Alexander A. Balandin

Keyword(s):

Image Processing ◽

Quality Control ◽

Large Scale ◽

Processing Technique ◽

Image Processing Technique ◽

Automated Identification ◽

Cvd Graphene

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CFD Simulations of a Large-Scale Seed Precipitation Tank Stirred with Multiple Intermig Impellers

Light Metals 2015 ◽

10.1002/9781119093435.ch12 ◽

2015 ◽

pp. 63-68 ◽

Cited By ~ 1

Author(s):

Guoquan Zhang ◽

Hongliang Zhao ◽

Chao Lv ◽

Yan Liu ◽

Ting-an Zhang

Keyword(s):

Large Scale ◽

Cfd Simulations ◽

Seed Precipitation

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CVD Graphene Growth for Redox Reactions to Renewable Energy Applications

ECS Meeting Abstracts ◽

10.1149/ma2018-01/5/639 ◽

2018 ◽

Keyword(s):

Renewable Energy ◽

Redox Reactions ◽

Graphene Growth ◽

Cvd Graphene ◽

Energy Applications

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An Immersive and Interactive Visualization System for Large-Scale CFD

Volume 2: Symposia, Parts A, B, and C ◽

10.1115/fedsm2003-45201 ◽

2003 ◽

Cited By ~ 3

Author(s):

Yuichi Matsuo

Keyword(s):

Large Scale ◽

Interactive Visualization ◽

Cfd Simulations ◽

Output Data ◽

Visualization System ◽

Aerospace Research ◽

Projection Screen ◽

Computational Fluid Dynamics Cfd ◽

Collaboration And Communication ◽

Rear Projection Screen

We have been long involved in large-scale computational fluid dynamics (CFD) simulations in aerospace research. These days, as the computer power grows, output data from the simulations becomes larger and larger, and we feel that the current visualization methodology has its limitation in understanding. Thus, with the target concepts of reality, collaboration, and communication, we has built an immersive and interactive visualization system with a large-sized wall-type display. The system, which has been in operation since April 2001, is driven by a SGI Onyx 3400 server with 32 CPUs, 64Gbytes memory, and 6 IR3 graphics pipelines, and comprises a 4.6×1.5-meter (15×5-foot) rear projection screen with 3 high-resolution CRT projectors, supporting stereoscopic viewing, easy color/luminosity matching, and accurate edge-blending. The system is mainly used for visualization of large-scale CFD simulations. This paper will describe the new visualization system introduced at the National Aerospace Laboratory of Japan, and the features of the system are discussed while illustrating some typical visualized examples.

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