Three-dimensional macro-scale micro-structure imaging with deep ultraviolet excitation

Flash Nanoprecipitation (FNP) is a technique to produce monodisperse functional nanoparticles through rapidly mixing a saturated solution and a non-solvent. Multi-inlet vortex reactors (MIVR) have been effectively applied to FNP due to their ability to provide both rapid mixing and the flexibility of inlet flow conditions. Until recently, only micro-scale MIVRs have been demonstrated to be effective in FNP. A scaled-up MIVR could potentially generate large quantities of functional nanoparticles, giving FNP wider applicability in the industry. In the present research, turbulent mixing inside a scaled-up, macro-scale MIVR was measured by stereoscopic particle image velocimetry (SPIV). Reynolds number of this reactor is defined based on the bulk inlet velocity, ranging from 3290 to 8225. It is the first time that the three-dimensional velocity field of a MIVR was experimentally measured. The influence of Reynolds number on mean velocity becomes more linear as Reynolds number increases. An analytical vortex model was proposed to well describe the mean velocity profile. The turbulent characteristics such as turbulent kinematic energy and Reynolds stress are also presented. The wandering motion of vortex center was found to have a significant contribution to the turbulent kinetic energy of flow near the center area.

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A simple, repeatable and highly stable self-powered solar-blind photoelectrochemical-type photodetector using amorphous Ga2O3 films grown on 3D carbon fiber paper

Journal of Materials Chemistry C ◽

10.1039/d1tc02471j ◽

2021 ◽

Author(s):

Lijuan Huang ◽

Zhengrui Hu ◽

Hong Zhang ◽

Yuanqiang Xiong ◽

Shiqiang Fan ◽

...

Keyword(s):

Carbon Fiber ◽

Gallium Oxide ◽

Three Dimensional ◽

Next Generation ◽

Solar Blind ◽

Carbon Fiber Paper ◽

Deep Ultraviolet ◽

Self Powered ◽

Ultraviolet Photodetectors

Gallium oxide (Ga2O3) has been extensively studied in recent years because it is a natural candidate material for next-generation solar-blind deep ultraviolet photodetectors (PDs). Herein, a three dimensional (3D) amorphous...

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On the Two-Scale Modelling of Elastohydrodynamic Lubrication in Tilted-Pad Bearings

Lubricants ◽

10.3390/lubricants6030078 ◽

2018 ◽

Vol 6 (3) ◽

pp. 78 ◽

Cited By ~ 3

Author(s):

Gregory de Boer ◽

Andreas Almqvist

Keyword(s):

Surface Topography ◽

Load Capacity ◽

Three Dimensional ◽

Elastohydrodynamic Lubrication ◽

Multiscale Methods ◽

Operating Conditions ◽

Real Surface ◽

Micro Scale ◽

Macro Scale ◽

Heterogeneous Multiscale

A two-scale method for modelling the Elastohydrodynamic Lubrication (EHL) of tilted-pad bearings is derived and a range of solutions are presented. The method is developed from previous publications and is based on the Heterogeneous Multiscale Methods (HMM). It facilitates, by means of homogenization, incorporating the effects of surface topography in the analysis of tilted-pad bearings. New to this article is the investigation of three-dimensional bearings, including the effects of both ideal and real surface topographies, micro-cavitation, and the metamodeling procedure used in coupling the problem scales. Solutions for smooth bearing surfaces, and under pure hydrodynamic operating conditions, obtained with the present two-scale EHL model, demonstrate equivalence to those obtained from well-established homogenization methods. Solutions obtained for elastohydrodynamic operating conditions, show a dependency of the solution to the pad thickness and load capacity of the bearing. More precisely, the response for the real surface topography was found to be stiffer in comparison to the ideal. Micro-scale results demonstrate periodicity of the flow and surface topography and this is consistent with the requirements of the HMM. The means of selecting micro-scale simulations based on intermediate macro-scale solutions, in the metamodeling approach, was developed for larger dimensionality and subsequent calibration. An analysis of the present metamodeling approach indicates improved performance in comparison to previous studies.

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Three-Dimensional Quantum Confinement of Charge Carriers in Self-Organized AlGaN Nanowires: A Viable Route to Electrically Injected Deep Ultraviolet Lasers

Nano Letters ◽

10.1021/acs.nanolett.5b02133 ◽

2015 ◽

Vol 15 (12) ◽

pp. 7801-7807 ◽

Cited By ~ 50

Author(s):

S. Zhao ◽

S. Y. Woo ◽

M. Bugnet ◽

X. Liu ◽

J. Kang ◽

...

Keyword(s):

Quantum Confinement ◽

Three Dimensional ◽

Charge Carriers ◽

Self Organized ◽

Deep Ultraviolet ◽

Ultraviolet Lasers

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Investigation on Light Extraction Behavior of Surface Plasmon-Coupled Deep-Ultraviolet LED in Different Emission Directions

Crystals ◽

10.3390/cryst12010082 ◽

2022 ◽

Vol 12 (1) ◽

pp. 82

Author(s):

Mei Ge ◽

Yi Li ◽

Youhua Zhu ◽

Meiyu Wang

Keyword(s):

Surface Plasmon ◽

Three Dimensional ◽

Strong Absorption ◽

Light Extraction ◽

Light Extraction Efficiency ◽

Time Domain Simulation ◽

Al Nanoparticles ◽

Extraction Behavior ◽

Deep Ultraviolet ◽

Difference Time

The light extraction behavior of an AlGaN-based deep-ultraviolet LED covered with Al nanoparticles (NPs) is investigated by three-dimensional finite-difference time-domain simulation. For the transmission spectra of s- and p-polarizations in different emission directions, the position of maximum transmittance can be changed from (θ = 0°, λ = 273 nm) to (θ = 0°, λ = 286 nm) by increasing the diameter of Al NPs from 40 nm to 80 nm. In the direction that is greater than the critical angle, the transmittance of s-polarization is very small due to the strong absorption of Al NPs, while the transmittance spectrum of p-polarization can be observed obviously for the 80 nm Al NPs structure. For a ~284 nm AlGaN-based LED with surface plasmon (SP) coupling, although the luminous efficiency is significantly improved due to the improvement of the radiation recombination rate as compared with the conventional LED, the light extraction efficiency (LEE) is lower than 2.61% of the conventional LED without considering the lateral surface extraction and bottom reflection. The LEE is not greater than ~0.98% (~2.12%) for an SP coupling LED with 40 nm (80 nm) Al NPs. The lower LEE can be attributed to the strong absorption of Al NPs.

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Three-Dimensional Visualization of the Micro-Structure and Mechanism of Magnetorheological Fluids Using Digital Micro-Holography

Chinese Journal of Lasers ◽

10.3788/cjl201441.0409002 ◽

2014 ◽

Vol 41 (4) ◽

pp. 0409002

Author(s):

王秋宽 Wang Qiukuan ◽

杨鸿 Yang Hong ◽

李光勇 Li Guangyong ◽

杨岩 Yang Yan

Keyword(s):

Three Dimensional ◽

Magnetorheological Fluids ◽

Micro Structure

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Digital laser micro- and nanoprinting

Nanophotonics ◽

10.1515/nanoph-2018-0103 ◽

2018 ◽

Vol 8 (1) ◽

pp. 27-44 ◽

Cited By ~ 9

Author(s):

Qingfeng Li ◽

David Grojo ◽

Anne-Patricia Alloncle ◽

Boris Chichkov ◽

Philippe Delaporte

Keyword(s):

Three Dimensional ◽

Digital Fabrication ◽

Two Dimensions ◽

Minimum Size ◽

Direct Writing ◽

3D Objects ◽

Wide Range ◽

Macro Scale ◽

Forward Transfer ◽

Pros And Cons

AbstractLaser direct writing is a well-established ablation technology for high-resolution patterning of surfaces, and since the development of additive manufacturing, laser processes have also appeared very attractive for the digital fabrication of three-dimensional (3D) objects at the macro-scale, from few millimeters to meters. On the other hand, laser-induced forward transfer (LIFT) has demonstrated its ability to print a wide range of materials and to build functional micro-devices. For many years, the minimum size of laser-printed pixels was few tens of micrometers and is usually organized in two dimensions. Recently, new approaches have been investigated, and the potential of LIFT technology for printing 2D and 3D sub-micrometer structures has become real. After a brief description of the LIFT process, this review presents the pros and cons of the different digital laser printing technologies in the aim of the additive nanomanufacturing application. The transfer of micro- and nano-dots in the liquid phase from a solid donor film appears to be the most promising approach to reach the goal of 3D nanofabrication, and the latest achievements obtained with this method are presented and discussed.

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Three-Dimensional Laser Printing of Macro-Scale Glass Objects at a Micro-Scale Resolution

Micromachines ◽

10.3390/mi10090565 ◽

2019 ◽

Vol 10 (9) ◽

pp. 565 ◽

Cited By ~ 8

Author(s):

Peng Wang ◽

Wei Chu ◽

Wenbo Li ◽

Yuanxin Tan ◽

Fang Liu ◽

...

Keyword(s):

3D Printing ◽

Three Dimensional ◽

Laser Pulses ◽

Fused Silica ◽

Rapid Expansion ◽

Ultrafast Laser Pulses ◽

3D Objects ◽

Macro Scale ◽

Powerful Approach ◽

3D Printing Technique

Three-dimensional (3D) printing has allowed for the production of geometrically complex 3D objects with extreme flexibility, which is currently undergoing rapid expansion in terms of materials, functionalities, as well as areas of application. When attempting to print 3D microstructures in glass, femtosecond laser-induced chemical etching (FLICE)—which is a subtractive 3D printing technique—has proved itself a powerful approach. Here, we demonstrate the fabrication of macro-scale 3D glass objects of large heights up to ~3.8 cm with an identical lateral and longitudinal feature size of ~20 μm. The remarkable accomplishment is achieved by revealing an unexplored regime in the interaction of ultrafast laser pulses with fused silica, which results in depth-insensitive focusing of the laser pulses inside fused silica.

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