<i>Influence of UAV Rotor Down-wash Airflow For Droplet Penetration</i>

2018 ◽  
Author(s):  
Zhilun Yang ◽  
Lijun Qi ◽  
Yalei Wu
Keyword(s):  
Droplet Penetration

Analysis of water droplet penetration in earth plasters using X-ray microtomography

2021 ◽  
Vol 283 ◽  
pp. 122651
Author(s):  
T. Mauffré ◽  
E. Keita ◽  
E. Contraires ◽  
F. McGregor ◽  
A. Fabbri
Keyword(s):  
Water Droplet ◽  
X Ray ◽  
Droplet Penetration

scholarly journals Impact of operating conditions on the evolution of droplet penetration in oil mist filters

2019 ◽  
Vol 211 ◽  
pp. 697-703 ◽  
Author(s):  
T. Penner ◽  
J. Meyer ◽  
G. Kasper ◽  
A. Dittler
Keyword(s):  
Operating Conditions ◽  
Oil Mist ◽  
Droplet Penetration

scholarly journals Application of transparent microperforated panel to acrylic partitions for desktop use: A case study by prototyping

2021 ◽  
Author(s):  
Kimihiro Sakagami ◽  
Midori Kusaka ◽  
Takeshi Okuzono ◽  
Shigeyuki Kido ◽  
Daichi Yamaguchi
Keyword(s):  
Adverse Effect ◽  
Sound Absorption ◽  
Acoustic Environment ◽  
Actual Use ◽  
Acrylic Sheet ◽  
Absorption Performance ◽  
The Subject ◽  
Droplet Penetration ◽  
Absorption Characteristics

There are various measures currently in place to prevent the spread of COVID-19; however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to a possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings of the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. This time, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.

Effect of oxygen deprivation on soil hydrophobicity during heating

2005 ◽  
Vol 14 (4) ◽  
pp. 449 ◽  
Author(s):  
R. Bryant ◽  
S. H. Doerr ◽  
M. Helbig
Keyword(s):  
Heat Source ◽  
Forest Soils ◽  
Water Droplet ◽  
Oxygen Deprivation ◽  
Eucalypt Forest ◽  
Soil Hydrophobicity ◽  
Effect Of Oxygen ◽  
Penetration Time ◽  
Droplet Penetration ◽  
Heating Duration

Previous studies of the effects of heating on soil hydrophobicity have been conducted under free availability of oxygen. Under fire, however, soils may be deprived of oxygen due to its consumption at the heat source and inadequate replenishment in the soil. In the present study, effects of heating on soil hydrophobicity are examined for three initially hydrophobic Australian eucalypt forest soils under standard and oxygen-deprived atmospheres for temperatures (T) of 250–600°C and durations (tE) 2–180 min. Hydrophobicity assessments using water droplet penetration time (WDPT) tests indicate substantial differences between the absence and presence of oxygen. Heating to 250–300°C enhanced hydrophobicity from initial respective WDPTs of 2029 s, 361 s and 15 s to > 18 000 s for all samples under both atmospheres. Depending on heating duration, hydrophobicity was eliminated (WDPTs ~0 s) in air between 210 and 340°C, but under oxygen-deprived conditions between 400 and 510°C. Relationships between the destruction temperature for hydrophobicity TD and tE provide temperature–duration thresholds below which hydrophobicity persists under oxygen concentrations <21%. As established temperature–duration thresholds for hydrophobicity destruction are based on the free availability of oxygen, caution is advised in their applicability to field situations where heating under burning may occur in oxygen-depleted conditions.

scholarly journals Application of transparent microperforated panel to acrylic partitions for desktop use: A case study by prototyping

2021 ◽  
Author(s):  
Kimihiro Sakagami ◽  
Midori Kusaka ◽  
Takeshi Okuzono ◽  
Shigeyuki Kido ◽  
Daichi Yamaguchi
Keyword(s):  
Adverse Effect ◽  
Sound Absorption ◽  
Acoustic Environment ◽  
Actual Use ◽  
Acrylic Sheet ◽  
Absorption Performance ◽  
The Subject ◽  
Droplet Penetration ◽  
Absorption Characteristics

There are various measures currently in place to prevent the spread of COVID-19; however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to a possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings of the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. This time, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.

Droplet penetration into porous networks: Role of pore morphology

2000 ◽  
Vol 15 (5) ◽  
pp. 554-563 ◽  
Author(s):  
Tim J. Senden ◽  
Mark A. Knackstedt ◽  
M. Bruce Lyne
Keyword(s):  
Pore Morphology ◽  
Porous Networks ◽  
Droplet Penetration

Pyrogenic Evidence in Paleosols along the North Saskatchewan River in the Rocky Mountains of Alberta

1975 ◽  
Vol 12 (7) ◽  
pp. 1238-1244 ◽  
Author(s):  
J. F. Dormaar ◽  
L. E. Lutwick
Keyword(s):  
Magnetic Susceptibility ◽  
Rocky Mountains ◽  
Water Droplet ◽  
River Valley ◽  
Mineral Matter ◽  
Fe Oxides ◽  
The North ◽  
Organic Debris ◽  
Vertical Sections ◽  
Droplet Penetration

Vertical sections of paleosols along the Upper North Saskatchewan River valley show horizons that have distinct brown to reddish-brown colors. Based on such criteria as time for water droplet penetration, magnetic susceptibility, and crystallization of Fe oxides, together with present conditions and vegetation of the fans and floodplain in that area, it was concluded that these brown horizons were fire-affected. The organic debris in the bogs before a fire is continually being enriched with silt blowing from the floodplain. The colored horizons are considered to be a combination of accessed eolian matter reddened in the layer of burning debris and some mineral matter reddened by conducted heat.

scholarly journals Application of transparent microperforated panels to acrylic partitions for desktop use: A case study by prototyping

2021 ◽  
Vol 2 ◽  
Author(s):  
Kimihiro Sakagami ◽  
Midori Kusaka ◽  
Takeshi Okuzono ◽  
Shigeyuki Kido ◽  
Daichi Yamaguchi
Keyword(s):  
Adverse Effect ◽  
Sound Absorption ◽  
Acoustic Environment ◽  
Actual Use ◽  
Acrylic Sheet ◽  
Absorption Performance ◽  
The Subject ◽  
Droplet Penetration ◽  
Absorption Characteristics

There are various measures currently in place to prevent the spread of coronavirus (COVID-19); however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to prevent possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings on the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. For this study, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.

A Novel Biomimetic Nanocomposite Exhibiting Petal Wetting Phenomenon: Fabrication and Experimental Investigations

2022 ◽  
Author(s):  
Adithya Lenin ◽  
Pandurangan Arumugam ◽  
Aruna Prakasa Rao ◽  
Angayarkanny Subramanian
Keyword(s):  
Electron Microscopy ◽  
Water Droplet ◽  
Laser Scanning ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Boron Nitride Nanotubes ◽  
Biological Research ◽  
Experimental Investigations ◽  
Roughness Parameters ◽  
Droplet Penetration

Abstract A functional composite material that simultaneously exhibits hydrophobicity and water droplet adhesion has monumental potential in controlling fluid flow, studying phase separation, and biological research. This article reports the fabrication of a petal wetting biomimetic Boron Nitride Nanotubes (BNNTs) -Polydimethylsiloxane (PDMS) nanocomposite achieved by drop casting. The petal effect was investigated by non-destructive techniques. The nanotubes were synthesized by chemical vapor deposition at 1150 °C and were characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The mean diameter of the nanotubes was found to be 70 nm. The nanocomposites had BNNT fillers ranging from 0.5 wt. % to 2 wt. %. Water contact angles for pure PDMS polymer was 94.7° and for the 2 wt. % BNNT-PDMS nanocomposite was 132.4°. The petal wetting nanocomposite displayed a characteristic trait of high contact angle hysteresis. The surface roughness parameters of the nanocomposites were determined by atomic force microscopy. Laser scanning confocal microscopy aided in analyzing the droplet penetration and in observing the trapped air between the water droplet and the nanocomposite surface. Based on surface observations, roughness parameters, and the extent of droplet penetration by the surface, we shed light on the Cassie impregnating wetting regime followed by the biomimetic nanocomposite. Such a surface would be beneficial in the study of the embryogenesis of cells and aid in moisture collection.

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