Laser-Enhanced Ionization Flame Velocimeter

1982 ◽  
Vol 36 (2) ◽  
pp. 168-171 ◽  
Author(s):  
P. K. Schenck ◽  
J. C. Travis ◽  
G. C. Turk ◽  
T. C. O'Haver
Keyword(s):  
Laminar Flow ◽  
Low Power ◽  
Flow Velocity ◽  
Neutral Atom ◽  
Seed Density ◽  
Spatial Evolution ◽  
Atom Density ◽  
Low Sodium ◽  
Temporal And Spatial ◽  
Better Than

The temporal and spatial evolution of the depleted neutral atom density following laser-enhanced ionization in laminar flow flames has been used to characterize the flow velocity of the flame gases. This technique utilizes a low power cw dye laser and a low sodium seed density (1011 to 1012 atoms/ml). The flow velocity can be measured to better than 2% in standard analytical burners.

Fast Nanoscopic Velocimetry for Micro/Nanofluidics

2009 ◽  
Author(s):  
Cuifang Kuang ◽  
Guiren Wang
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Spatial Resolution ◽  
State Of The Art ◽  
Laser Induced Fluorescence ◽  
Stimulated Emission ◽  
Time Flow ◽  
Temporal And Spatial ◽  
First Time ◽  
Better Than

We presented two kinds of innovative velocimetry with high temporal and spatial resolution respectively based on the Laser Induced Fluorescence Photobleaching Anemometer (LIFPA) and Stimulated Emission Depletion (STED) techniques. The temporal and spatial resolution has been for the first time achieved to 5–10 μs and 70 nm, respectively. To our knowledge, the temporal resolution is about 100× better than that of the state of the art microPIV, which is currently the most widely used velocimetry in microfluidics community. And for the first time, flow velocity distribution in a nanocapillary has been measured with a spatial resolution better than 70 nm.

scholarly journals The NUADU experiment on TC-2 and the first Energetic Neutral Atom (ENA) images recorded by this instrument

2005 ◽  
Vol 23 (8) ◽  
pp. 2825-2849 ◽  
Author(s):  
S. McKenna-Lawlor ◽  
L. Li ◽  
S. Barabash ◽  
K. Kudela ◽  
J. Balaz ◽  
...  
Keyword(s):  
Neutral Atom ◽  
Ring Current ◽  
Global Scale ◽  
Measurement Range ◽  
Spatial Evolution ◽  
Energetic Neutral Atom ◽  
Temporal And Spatial ◽  
Low Altitude ◽  
Northern And Southern Hemispheres ◽  
South Polar

Abstract. The Earth’s ring current and how it responds to varying interplanetary conditions is described and an account provided of the production of Energetic Neutral Atoms (ENAs) in the geo-corona. Also, the potential to remotely monitor, on a global scale, the temporal and spatial evolution of magnetospheric plasma populations through analysing ENA images recorded during magnetic storms/substorms is indicated. A technical account of the Energetic NeUtral Atom Detector Unit NUADU aboard China’s TC-2 mission (measurement range 45–>158 keV) follows, together with an account of the scientific objectives of NUADU, both in stand-alone mode and in the context of multi-point imaging. Low altitude ENA emissions recorded by NUADU during south polar passages of TC-2 at the time of a moderate magnetic storm in September 2004, as well as bright ring current emissions recorded in November 2004 during a major geomagnetic storm, are presented and discussed in the context of various, accompanying, terrestrial disturbances. Also, ENA observations of the November 2004 ring current imaged simultaneously by TC-2/NUADU and by IMAGE/ HENA (viewing, respectively, from the Northern and Southern Hemispheres), are compared.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

scholarly journals Injection-rolling nozzle in an imprint system with continuous injection direct rolling for ultra-thin microstructure guide light plate

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Yan Lou ◽  
Kewei Chen ◽  
Xiangwei Zhou ◽  
Yanfeng Feng
Keyword(s):  
Flow Velocity ◽  
Superior Performance ◽  
Light Transmittance ◽  
Velocity Difference ◽  
Orthogonal Experiments ◽  
Width Direction ◽  
Direct Rolling ◽  
Simulation Results ◽  
Continuous Injection ◽  
Better Than

A novel Injection-rolling Nozzle (IRN) in an imprint system with continuous injection direct rolling (CIDR) for ultra-thin microstructure polymer guide light plates was developed to achieve uniform flow velocity and temperature at the width direction of the cavity exit. A novel IRN cavity was designed. There are eight of feature parameters of cavity were optimized by orthogonal experiments and numerical simulation. Results show that the flow velocity at the width direction of the IRN outlet can reach uniformity, which is far better than that of traditional cavity. The smallest flow velocity difference and temperature difference was 0.6 mm/s and 0.24 K, respectively. The superior performance of the IRN was verified through a CIDR experiment. Several 0.35-mm thick, 340-mm wide, and 10-m long microstructural Polymethyl Methacrylate (PMMA) guide light plates were manufactured. The average filling rates of the microgrooves with the aspect ratio 1:3 reached above 93%. The average light transmittance is 88%.

Thermohydraulics of Laminar Flow Through Rectangular and Square Ducts With Transverse Ribs and Twisted Tapes

2006 ◽  
Vol 128 (10) ◽  
pp. 1070-1080 ◽  
Author(s):  
Debashis Pramanik ◽  
Sujoy K. Saha
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Laminar Flows ◽  
Short Length ◽  
Full Length ◽  
Twisted Tape ◽  
Twisted Tapes ◽  
Square Ducts ◽  
Better Than

The heat transfer and the pressure drop characteristics of laminar flow of viscous oil through rectangular and square ducts with internal transverse rib turbulators on two opposite surfaces of the ducts and fitted with twisted tapes have been studied experimentally. The tapes have been full length, short length, and regularly spaced types. The transverse ribs in combination with full-length twisted tapes have been found to perform better than either ribs or twisted tapes acting alone. The heat transfer and the pressure drop measurements have been taken in separate test sections. Heat transfer tests were carried out in electrically heated stainless steel ducts incorporating uniform wall heat flux boundary conditions. Pressure drop tests were carried out in acrylic ducts. The flow was periodically fully developed in the regularly spaced twisted-tape elements case and decaying swirl flow in the short-length twisted tapes case. The flow characteristics are governed by twist ratio, space ratio, and length of twisted tape, Reynolds number, Prandtl number, rod-to-tube diameter ratio, duct aspect ratio, rib height, and rib spacing. Correlations developed for friction factor and Nusselt number have predicted the experimental data satisfactorily. The performance of the geometry under investigation has been evaluated. It has been found that on the basis of both constant pumping power and constant heat duty, the regularly spaced twisted-tape elements in specific cases perform marginally better than their full-length counterparts. However, the short-length twisted-tape performance is worse than the full-length twisted tapes. Therefore, full-length twisted tapes and regularly spaced twisted-tape elements in combination with transverse ribs are recommended for laminar flows. However, the short-length twisted tapes are not recommended.

scholarly journals Temporal and spatial evolution of dynamic support from river profiles: A framework for Madagascar

2012 ◽  
Vol 13 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gareth G. Roberts ◽  
Jonathan D. Paul ◽  
Nicky White ◽  
Jeffrey Winterbourne
Keyword(s):  
Spatial Evolution ◽  
Temporal And Spatial Evolution ◽  
Dynamic Support ◽  
Temporal And Spatial ◽  
River Profiles

Optical Diagnostics of Temporal and Spatial Evolution of a Reacting Diesel Fuel Jet

1999 ◽  
Vol 148 (1-6) ◽  
pp. 1-16 ◽  
Author(s):  
MASSIMO ASTARITA ◽  
FELICE E. CORCIONE ◽  
BIANCA MARIA VAGLIECO ◽  
GERARDO VALENTINO
Keyword(s):  
Diesel Fuel ◽  
Optical Diagnostics ◽  
Spatial Evolution ◽  
Temporal And Spatial Evolution ◽  
Fuel Jet ◽  
Temporal And Spatial

scholarly journals Asymmetries in mutual understanding: People with low status, power, and self-esteem understand better than they are understood

2020 ◽  
Author(s):  
Sanaz Talaifar ◽  
Michael Buhrmester ◽  
Ozlem Ayduk ◽  
william swann
Keyword(s):  
Low Power ◽  
Conceptual Analysis ◽  
Self Esteem ◽  
Mutual Understanding ◽  
Insight Into ◽  
Better Than

NOW PUBLISHED: https://doi.org/10.1177/1745691620958003. All too often, people who develop exceptionally astute insights into others remain mysterious to these others. Evidence for such asymmetric understanding comes from several independent domains. Striking asymmetries occur among those who differ in status and power, such that low status, low power individuals understand more than they are understood. We show that this effect extends to people who merely perceive that they have low status: individuals with low self-esteem. Whereas people with low self-esteem display insight into people with high self-esteem, their high self-esteem counterparts fail to reciprocate. Conceptual analysis suggests that asymmetries in mutual understanding may be reduced by addressing deficits in information and motivation among perceivers. Nevertheless, evidence from several interventions were unsuccessful, indicating that the path to symmetric understanding is a steep and thorny one. Further research is needed to develop strategies for fostering understanding of those who are most misunderstood: people with low self-esteem, low status, and low power.

scholarly journals Temporal and Spatial Evolution of Brain Network Topology during the First Two Years of Life

PLoS ONE ◽  
2011 ◽  
Vol 6 (9) ◽  
pp. e25278 ◽  
Author(s):  
Wei Gao ◽  
John H. Gilmore ◽  
Kelly S. Giovanello ◽  
Jeffery Keith Smith ◽  
Dinggang Shen ◽  
...  
Keyword(s):  
Network Topology ◽  
Brain Network ◽  
Spatial Evolution ◽  
Temporal And Spatial Evolution ◽  
Temporal And Spatial
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