Autoignition behavior of a spherical cluster consisted of a center fine droplet and surrounding twelve fine droplets

2015 ◽  
Vol 35 (2) ◽  
pp. 1629-1637 ◽  
Author(s):  
H. Kataoka ◽  
H. Yamashita ◽  
J. Tada ◽  
Y. Oka ◽  
Y. Morinaga ◽  
...  
Keyword(s):  
Spherical Cluster ◽  
Fine Droplet

scholarly journals Mono-energetic ions from collisionless expansion of spherical multi-species clusters

2009 ◽  
Vol 27 (2) ◽  
pp. 321-326 ◽  
Author(s):  
K.I. Popov ◽  
V.Yu. Bychenkov ◽  
W. Rozmus ◽  
V.F. Kovalev ◽  
R.D. Sydora
Keyword(s):  
Electron Temperature ◽  
Time Evolution ◽  
Hot Electrons ◽  
Ion Concentration ◽  
Energy Spectra ◽  
Plasma Expansion ◽  
Energetic Ions ◽  
Spherical Cluster ◽  
Light Ions ◽  
Unified Description

AbstractKinetic collisionless expansion of a spherical cluster composed of light and heavy cold ions and hot electrons is studied for arbitrary electron temperature. A wide set of regimes of plasma expansion, from nearly quasi-neutral to Coulomb explosion, is described from a unified description. The time evolution of the velocity, density, and energy spectra for accelerated ions is studied. The study demonstrates that an optimum light ion concentration from few percent to few tens percent, depending on the electron temperature, leads to a quasi-monoenergetic spectra with numbers as high as 70–80% of the total number of light ions.

scholarly journals Design and Characterizations of Inhalable Poly(lactic-co-glycolic acid) Microspheres Prepared by the Fine Droplet Drying Process for a Sustained Effect of Salmon Calcitonin

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1311 ◽  
Author(s):  
Hideyuki Sato ◽  
Aiko Tabata ◽  
Tatsuru Moritani ◽  
Tadahiko Morinaga ◽  
Takahiro Mizumoto ◽  
...  
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
Salmon Calcitonin ◽  
Glycolic Acid ◽  
Pharmacological Action ◽  
Conformational Structure ◽  
Intratracheal Administration ◽  
Fine Droplet ◽  
Droplet Drying

The present study aimed to develop inhalable poly (lactic-co-glycolic acid) (PLGA)-based microparticles of salmon calcitonin (sCT) for sustained pharmacological action by the fine droplet drying (FDD) process, a novel powderization technique employing printing technologies. PLGA was selected as a biodegradable carrier polymer for sustained-release particles of sCT (sCT/SR), and physicochemical characterizations of sCT/SR were conducted. To estimate the in vivo efficacy of the sCT/SR respirable powder (sCT/SR-RP), plasma calcium levels were measured after intratracheal administration in rats. The particle size of sCT/SR was 3.6 µm, and the SPAN factor, one of the parameters to present the uniformity of particle size distribution, was calculated to be 0.65. In the evaluation of the conformational structure of sCT, no significant changes were observed in sCT/SR even after the FDD process. The drug release from sCT/SR showed a biphasic pattern with an initial burst and slow diffusion in simulated lung fluid. sCT/SR-RP showed fine inhalation performance, as evidenced by a fine particle fraction value of 28% in the cascade impactor analysis. After the insufflation of sCT samples (40 µg-sCT/kg) in rats, sCT/SR-RP could enhance and prolong the hypocalcemic action of sCT possibly due to the sustained release and pulmonary absorption of sCT. From these observations, the strategic application of the FDD process could be efficacious to provide PLGA-based inhalable formulations of sCT, as well as other therapeutic peptides, to enhance their biopharmaceutical potentials.

Spray Application Efficiency from a Multi-Rotor Unmanned Aerial Vehicle Configured for Aerial Pesticide Application

2019 ◽  
Vol 62 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Brian Richardson ◽  
Carol A. Rolando ◽  
Mark O. Kimberley ◽  
Tara M. Strand
Keyword(s):  
Wind Speed ◽  
Unmanned Aerial Vehicle ◽  
Droplet Size ◽  
Small Range ◽  
Surprising Result ◽  
Spray Application ◽  
Size Classes ◽  
Fine Droplet ◽  
Application Efficiency ◽  
Aerial Vehicle

HighlightsThe swath pattern was measured from an Agras MG-1 UAV spraying fine and extra-coarse droplet spectra.The recommended lane separation of 3.6 m did not differ for the two droplet size classes tested in this study.The applied spray deposited within the swath was higher with extra-coarse (>90%) than with fine (73%) droplets.There was potential for substantial downwind drift with fine droplets, even when flying close to the ground at low speed.Abstract. While there is increasing interest in the use of small, multi-rotor UAVs for application of agrichemicals, there is also uncertainty about their performance. Consequently, the purpose of this study was to quantify the performance of an Agras MG-1 with modified nozzle positions that, at the time of writing, was being used for commercial spraying in New Zealand. The approach was to release spray from the UAV along a single 50 m line. Spray deposits were measured using horizontal collectors placed on the ground in three 15 m transects centered on, and perpendicular to, the flight line. Airborne deposits were measured with a 10 m mast that supported spherical samplers at 1 m vertical intervals. Analysis of deposition data was undertaken to quantify factors influencing overall swath pattern variability, lane separation associated with a coefficient of variation (CV) of deposition of 30%, and spray application efficiency, which is the proportion of applied spray deposited within the swath. For two droplet size classes (extra-coarse and fine), the lane separation associated with a CV of 30% was about 3.6 m, with no significant effect of droplet size. This is a surprising result and may reflect the relatively small range of environmental conditions experienced during the field tests, including wind speed, which was relatively low for all tests. We speculate that this result may also be a consequence of the strong downwash. The swath width was positively correlated with wind speed. Spray efficiency was shown to be high (>90%) for the extra-coarse droplets but dropped significantly (73%) with the fine droplet spectrum. Combining in-swath deposition with the amount of airborne spray sampled in a 10 m vertical profile close to the edge of the swath accounted for 98.0% of the spray released with the extra-coarse spectrum but only 88.6% of the spray with the fine droplet spectrum. These results highlight that even with UAVs flying relatively close to the ground at a low forward speed, there is potential for substantial drift downwind of the swath when using smaller droplet size classes. Overall, the swath pattern was reasonably consistent across the two droplet size classes and for the narrow range of operational and meteorological conditions tested. Keywords: Aerial spraying, Pesticides, Spray application efficiency, Spray deposition, Swath pattern, UAV, Unmanned aerial vehicle.

Assessment of Sampling Techniques to Investigate Airborne Transport of Contaminants in Treated Wastewater from Sprinkler Irrigation Fine Droplet

2020 ◽  
Author(s):  
Mehrnaz Zardari ◽  
Séverine Tomas ◽  
Bruno Molle ◽  
Laurent Aprin ◽  
Sandrine Bayle ◽  
...  
Keyword(s):  
Sprinkler Irrigation ◽  
Treated Wastewater ◽  
Sampling Techniques ◽  
Fine Droplet ◽  
Airborne Transport

Performance of a Novel Rotating Gas-Liquid Separator

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
G. P. Willems ◽  
J. P. Kroes ◽  
M. Golombok ◽  
B. P. M. van Esch ◽  
H. P. van Kemenade ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Collection Efficiency ◽  
Separation Process ◽  
Major Influence ◽  
Descriptive Model ◽  
Capital Costs ◽  
Fine Droplet ◽  
Phase Separator ◽  
Scale Design ◽  
Liquid Separator

A novel gas separation process makes use of a rotating phase separator to separate micron-sized droplets from a gas stream. Based on an industrial scale design, a water/air separator is constructed and tested. The first experiment concerns the drainage of large fractions of separated liquid. During operation, drainage is observed via windows and a descriptive model is formulated. Because of the major influence on overall separation efficiency, liquid drainage is a key issue in the separator design. The second experiment comprises a droplet collection efficiency measurement using micron-sized droplets dispersed within the airstream. The separation efficiency of fine droplet removal is measured. This is an important factor in reducing capital costs.

Visualization and Characterization of the Flashing Spray of Cryogen R404a

2011 ◽  
Author(s):  
Z.-F. Zhou ◽  
W.-T. Wu ◽  
B. Chen ◽  
L.-J. Guo ◽  
Y.-S. Wang ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Droplet Diameter ◽  
Industrial Applications ◽  
Superheated Liquid ◽  
Liquid Droplets ◽  
Spray Distance ◽  
Spray Formation ◽  
Fine Droplet ◽  
Volatile Liquids ◽  
Laser Dermatology

Flashing spray of volatile liquids is a common phenomenon observed in many industrial applications such as fuel injection of engines, accidental release of flammable and toxic pressure-liquefied gases, failure of a vessel or pipe in the form of a small hole in chemical industry, and cryogenic spray cooling in laser dermatology. In flashing spray, the volatile liquid is depressurized rapidly at the exit of a nozzle (or a hole in a vessel) and becomes superheated. Such superheated liquid (in the form of either a jet or droplets) leads to explosive atomization, leading to fine droplet sizes and a short spray distance. This paper presents an experimental investigation of flashing spray of cryogen R404a. A photographic study of the spray is first conducted, providing visualization of spray formation and showing the dynamic characteristics of the spray. Then the R404a short spray is characterized by the phase Doppler particle analyzer (PDPA). The PDPA measurements provide the distributions of the diameter and velocities of liquid droplets in the spray., showing the dramatic dynamic variation of the liquid droplets due to explosive atomization of large droplets in the region near the exit of nozzle. The data finds that the average droplet axial velocity increases first to a maximum, followed by a gradual decrease, a typical variation expected for flashing spray. During the same time period, the average droplet diameter shows a quick decrease, from early large droplets of about 30 microns in diameter to fine droplet with about 10 microns within about 40 mm spray distance. This study provides quantitative data on droplet velocity and diameter in flashing spray, useful for model validation. The qualitative results help to have a better understanding of the flashing spray atomization mechanisms for volatile cryogens.

Distribution of the nucleation rate in the vicinity of a growing spherical cluster

1993 ◽  
Vol 362 (1-2) ◽  
pp. 21-31 ◽  
Author(s):  
A. Milchev ◽  
W.S. Kruijt ◽  
M. Sluyters-Rehbach ◽  
J.H. Sluyters
Keyword(s):  
Nucleation Rate ◽  
Spherical Cluster

Vibration characteristic of bubbles inside a spherical cluster

2016 ◽  
Vol 47 (2) ◽  
pp. 024301
Author(s):  
ChengHui WANG ◽  
RunYang MO ◽  
Jing HU ◽  
MingDuo ZHANG
Keyword(s):  
Vibration Characteristic ◽  
Spherical Cluster

Making homogeneous and fine droplet O/W emulsions using nonionic surfactants

1981 ◽  
Vol 58 (6) ◽  
pp. 738-743 ◽  
Author(s):  
Hiromichi Sagitani
Keyword(s):  
Nonionic Surfactants ◽  
Fine Droplet
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