scholarly journals High-Performance Three-Dimensional Electromagnetic Modelling Using Modified Neumann Series. Wide-Band Numerical Solution and Examples

1997 ◽  
Vol 49 (11) ◽  
pp. 1519-1539 ◽  
Author(s):  
Dmitry B. Avdeev ◽  
Alexei V. Kuvshinov ◽  
Oleg V. Pankratov ◽  
Gregory A. Newman
Keyword(s):  
Numerical Solution ◽  
High Performance ◽  
Three Dimensional ◽  
Wide Band ◽  
Neumann Series ◽  
Electromagnetic Modelling

Investigations On Flow And Flow-Induced Vibration Of Candu Fuel Bundles

2021 ◽  
Author(s):  
Alokendu Bhattacharya
Keyword(s):  
High Performance ◽  
Nuclear Reactor ◽  
Angular Position ◽  
Three Dimensional ◽  
Power Spectra ◽  
Wide Band ◽  
Major Step ◽  
Processing Scheme ◽  
Fuel Channel ◽  
Fuel Bundle

Excitations induced by three-dimensional unsteady flows of ordinary water coolant through a string of CANDU fuel bundles in a fuel channel are investigated in this thesis. Several comprehensive computational fluid dynamics (CFD) models are developed and solved by means of large eddy simulation (LES), high performance computers and parallel processing scheme. The 12-bundle flow model is the first ever developed concerning flow in a very complex CANDU fuel channel. The lateral fluid flow and flow-induced excitations on every fuel bundle are obtained and analyzed for various combinations of bundle angular positions. The coherent nature of the flow through the multiple bundles inside the fuel channel exhibiting fluid excitations of frequencies spreaded over a wide band in the power spectra is a source of bundle lateral vibration. The flow features of different bundle regime are correlated both in time and frequency domain and they are sensitive to the bundle-to-bundle angular position. This finding directs that, to study the flow and flow-induced excitations and vibrations of a bundle string, it is necessary to include all bundles for fluid-structure interactions. Results from the computational model reveal that the misaligned interface changes the flow pattern in the fuel channel. The mean lateral fluid forces increase by an order of magnitude and their RMS values raise about 3 to 4 times at some configurations compared to fully aligned situation. Experiments are also performed using the simulated CANDU bundles in an out-reactor setup to verify the computational results. An analysis of a complete fuel channel of a nuclear reactor using LES is at the forefront of current research worldwide and this study is a major step forward towards understanding and unfolding the fuel bundle vibration phenomenon.

Wireless communicating nodes at 60 GHz integrated on flexible substrate for short-distance instrumentation in aeronautics and space

2011 ◽  
Vol 4 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Mohamed Mehdi Jatlaoui ◽  
Daniela Dragomirescu ◽  
Mariano Ercoli ◽  
Michael Krämer ◽  
Samuel Charlot ◽  
...  
Keyword(s):  
High Performance ◽  
Flip Chip ◽  
Flexible Substrate ◽  
Three Dimensional ◽  
Wide Band ◽  
Cmos Technology ◽  
Electrical Contacts ◽  
Planar Antenna ◽  
60 Ghz ◽  
Polyimide Substrate

This paper presents the research done at LAAS-CNRS and in the context of “NANOCOMM” project. This project aims to demonstrate the potential of nanotechnology for the development of reconfigurable, ultra-sensitive, low consumption, and easy installation sensor networks with high performance in terms of reliability in line with the requirements of aeronautics and space. Each node of the sensor network is composed of nano-sensors, transceiver, and planar antenna. In this project, three-dimensional (3D) heterogeneous integration of these different components, on flexible polyimide substrate, is planned. Two types of sensors are selected for this project: strain gauges are used for the structure health monitoring (SHM) application and electrochemical cells are used to demonstrate the ability to detect frost phenomenon. After processing, sensors data are processed and transmitted to the reader unit using an ultra-wide band (UWB) transceiver. (digital baseband and radiofrequency (RF) head). The design and implementation of reconfigurable wireless communication architectures are provided according to the application requirements using nanoscale 65 nm CMOS technology. It is proposed to integrate on flexible substrate the transceiver using the flip-chip technique. A 60 GHz planar antenna is connected to the transceiver for the wireless data transmission. This paper is focused on the 3D integration techniques and the technological process used for the realization of such communicating nano-objects on polyimide substrate. The first assembly tests were carried out. Tests of interconnections quality and electrical contacts (Daisy Chain, calibration kit, etc.) were also performed with good results. A bumps contact resistance of 15 mΩ is measured.

scholarly journals Investigations On Flow And Flow-Induced Vibration Of Candu Fuel Bundles

2021 ◽  
Author(s):  
Alokendu Bhattacharya
Keyword(s):  
High Performance ◽  
Nuclear Reactor ◽  
Angular Position ◽  
Three Dimensional ◽  
Power Spectra ◽  
Wide Band ◽  
Major Step ◽  
Processing Scheme ◽  
Fuel Channel ◽  
Fuel Bundle

Excitations induced by three-dimensional unsteady flows of ordinary water coolant through a string of CANDU fuel bundles in a fuel channel are investigated in this thesis. Several comprehensive computational fluid dynamics (CFD) models are developed and solved by means of large eddy simulation (LES), high performance computers and parallel processing scheme. The 12-bundle flow model is the first ever developed concerning flow in a very complex CANDU fuel channel. The lateral fluid flow and flow-induced excitations on every fuel bundle are obtained and analyzed for various combinations of bundle angular positions. The coherent nature of the flow through the multiple bundles inside the fuel channel exhibiting fluid excitations of frequencies spreaded over a wide band in the power spectra is a source of bundle lateral vibration. The flow features of different bundle regime are correlated both in time and frequency domain and they are sensitive to the bundle-to-bundle angular position. This finding directs that, to study the flow and flow-induced excitations and vibrations of a bundle string, it is necessary to include all bundles for fluid-structure interactions. Results from the computational model reveal that the misaligned interface changes the flow pattern in the fuel channel. The mean lateral fluid forces increase by an order of magnitude and their RMS values raise about 3 to 4 times at some configurations compared to fully aligned situation. Experiments are also performed using the simulated CANDU bundles in an out-reactor setup to verify the computational results. An analysis of a complete fuel channel of a nuclear reactor using LES is at the forefront of current research worldwide and this study is a major step forward towards understanding and unfolding the fuel bundle vibration phenomenon.

Improved 3-D reconstruction using stereo computer graphics and multiple tilt EM images

1995 ◽  
Vol 53 ◽  
pp. 630-631
Author(s):  
Lee D. Peachey ◽  
Lou Fodor ◽  
John C. Haselgrove ◽  
Stanley M. Dunn ◽  
Junqing Huang
Keyword(s):  
Computer Graphics ◽  
High Performance ◽  
Transverse Section ◽  
Three Dimensional ◽  
Stereo Pair ◽  
3D Reconstructions ◽  
Video Cameras ◽  
Biological Objects ◽  
Microscope Images ◽  
High Performance Computer

Stereo pairs of electron microscope images provide valuable visual impressions of the three-dimensional nature of specimens, including biological objects. Beyond this one seeks quantitatively accurate models and measurements of the three dimensional positions and sizes of structures in the specimen. In our laboratory, we have sought to combine high resolution video cameras with high performance computer graphics systems to improve both the ease of building 3D reconstructions and the accuracy of 3D measurements, by using multiple tilt images of the same specimen tilted over a wider range of angles than can be viewed stereoscopically. Ultimately we also wish to automate the reconstruction and measurement process, and have initiated work in that direction.Figure 1 is a stereo pair of 400 kV images from a 1 micrometer thick transverse section of frog skeletal muscle stained with the Golgi stain. This stain selectively increases the density of the transverse tubular network in these muscle cells, and it is this network that we reconstruct in this example.

Rationally Designed Three-Dimensional Porous Nico 2n@C Reticular Structure for High-Performance Li-Ion Batteries

2020 ◽  
Author(s):  
Peiyao Wang ◽  
Bangchuan Zhao ◽  
Jin Bai ◽  
Kunzhen Li ◽  
Hongyang Ma ◽  
...  
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Li Ion Batteries ◽  
Reticular Structure ◽  
Li Ion

scholarly journals Polarization-sensitive photodetectors based on three-dimensional molybdenum disulfide (MoS2) field-effect transistors

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4719-4728
Author(s):  
Tao Deng ◽  
Shasha Li ◽  
Yuning Li ◽  
Yang Zhang ◽  
Jingye Sun ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistors ◽  
Three Dimensional ◽  
Polarized Light ◽  
Optical Field ◽  
Two Dimensional ◽  
Polarization Ratio ◽  
Two Dimensional Materials

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.

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