scholarly journals Fuel film thickness measurements using refractive index matching in a stratified-charge SI engine operated on E30 and alkylate fuels

2018 ◽  
Vol 59 (3) ◽  
Author(s):  
Carl-Philipp Ding ◽  
Magnus Sjöberg ◽  
David Vuilleumier ◽  
David L. Reuss ◽  
Xu He ◽  
...  
Keyword(s):  
Refractive Index ◽  
Film Thickness ◽  
Si Engine ◽  
Fuel Film ◽  
Stratified Charge ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Thickness Measurements

scholarly journals Effect of engine conditions and injection timing on piston-top fuel films for stratified direct-injection spark-ignition operation using E30

2019 ◽  
Vol 21 (2) ◽  
pp. 302-318 ◽  
Author(s):  
Carl-Philipp Ding ◽  
David Vuilleumier ◽  
Namho Kim ◽  
David L Reuss ◽  
Magnus Sjöberg ◽  
...  
Keyword(s):  
Refractive Index ◽  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Injection Timing ◽  
Fuel Film ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Wall Wetting ◽  
Direct Injection Spark Ignition

Mid-level ethanol/gasoline blends can provide knock resistance benefits for stoichiometric spark-ignition engine operation, but previous studies have identified challenges associated with spray impingement and wall wetting, leading to excessive particulate matter emissions. At the same time, stratified-charge spark-ignition operation can provide increased thermal efficiency, but care has to be exercised to avoid excessive in-cylinder soot formation. In support of the use of mid-level ethanol/gasoline blends in advanced spark-ignition engines, this study presents spray and fuel-film measurements in a direct-injection spark-ignition engine operated with a 30 vol.%/70 vol.% ethanol/gasoline blend (E30). Crank-angle resolved fuel-film measurements at the piston surface are conducted using two different implementations of the refractive index matching technique. A small-angle refractive index matching implementation allows quantification of the wetted area, while a large-angle refractive index matching implementation enables semi-quantitative measurements of fuel-film thickness and volume, in addition to fuel-film area. The fuel-film measurements show that both the amount of fuel deposited on the piston and the shape of the fuel-film patterns are strongly influenced by the injection timing, duration, intake pressure, and coolant temperature. For combinations of high in-cylinder gas density and long injection duration, merging of the individual spray plumes, commonly referred to as spray collapse, can cause a dramatic change to the shape and thickness of the wall fuel films. Overall, the study provides guidance to engine designers aiming at minimizing wall wetting through tailored combinations of injection timings and durations.

scholarly journals Refractive index matching applied to fecal smear clearing

2005 ◽  
Vol 47 (6) ◽  
pp. 347-350 ◽  
Author(s):  
Cláudio S. Ferreira
Keyword(s):  
Refractive Index ◽  
Sucrose Solution ◽  
Glycerol Solution ◽  
Human Feces ◽  
Microscope Slide ◽  
Helminth Eggs ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Fecal Smear ◽  
Effect Of Light

Thick smears of human feces can be made adequate for identification of helminth eggs by means of refractive index matching. Although this effect can be obtained by simply spreading a fleck of feces on a microscope slide, a glycerol solution has been routinely used to this end. Aiming at practicability, a new quantitative technique has been developed. To enhance both sharpness and contrast of the images, a sucrose solution (refractive index = 1.49) is used, which reduces the effect of light-scattering particulates. To each slide a template-measured (38.5 mm³) fecal sample is transferred. Thus, egg counts and sensitivity evaluations are easily made.

scholarly journals Biological glass: structural determinants of eye lens transparency

2011 ◽  
Vol 366 (1568) ◽  
pp. 1250-1264 ◽  
Author(s):  
Steven Bassnett ◽  
Yanrong Shi ◽  
Gijs F. J. M. Vrensen
Keyword(s):  
Refractive Index ◽  
Cellular Level ◽  
Structural Determinants ◽  
Lens Transparency ◽  
Index Matching ◽  
Lens Fibre ◽  
Refractive Index Matching ◽  
Lens Membranes ◽  
Adhesive Proteins ◽  
Structural Adaptations

The purpose of the lens is to project a sharply focused, undistorted image of the visual surround onto the neural retina. The first pre-requisite, therefore, is that the tissue should be transparent. Despite the presence of remarkably high levels of protein, the lens cytosol remains transparent as a result of short-range-order interactions between the proteins. At a cellular level, the programmed elimination of nuclei and other light-scattering organelles from cells located within the pupillary space contributes directly to tissue transparency. Scattering at the cell borders is minimized by the close apposition of lens fibre cells facilitated by a plethora of adhesive proteins, some expressed only in the lens. Similarly, refractive index matching between lens membranes and cytosol is believed to minimize scatter. Refractive index matching between the cytoplasm of adjacent cells is achieved through the formation of cellular fusions that allow the intermingling of proteins. Together, these structural adaptations serve to minimize light scatter and enable this living, cellular structure to function as ‘biological glass’.

scholarly journals Kilowatt-level direct-‘refractive index matching liquid’-cooled Nd:YLF thin disk laser resonator

2016 ◽  
Vol 24 (2) ◽  
pp. 1758 ◽  
Author(s):  
Zhibin Ye ◽  
Chong Liu ◽  
Bo Tu ◽  
Ke Wang ◽  
Qingsong Gao ◽  
...  
Keyword(s):  
Refractive Index ◽  
Thin Disk ◽  
Laser Resonator ◽  
Disk Laser ◽  
Index Matching ◽  
Refractive Index Matching ◽  
Thin Disk Laser
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