			Home About us Contact

Droplet Impact (droplet + impact)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Direct analysis of lipids in mouse brain using electrospray droplet impact/SIMS

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2010
Daiki Asakawa
Abstract Electrospray droplet impact (EDI)/secondary ion mass spectrometry (SIMS) is a new desorption/ionization technique for mass spectrometry in which highly charged water clusters produced from the atmospheric-pressure electrospray are accelerated in vacuum by 10 kV and impact the sample deposited on the metal substrate. EDI/SIMS was shown to enhance intact molecular ion formation dramatically compared to conventional SIMS. EDI/SIMS has been successfully applied to the analysis of mouse brain without any sample preparation. Five types of lipids, i.e. phosphatidylcholine (PC), phosphatidylserine, phosphatidylinositol (PI), galactocerebroside (GC) and sulfatide (ST), were readily detected from mouse brain section. In addition, by EDI/SIMS, six different regions of the mouse brain (cerebral cortex, corpus callosum, striatum, medulla oblongata, cerebellar cortex and cerebellar medulla) were examined. While GCs and STs were found to be rich in white matter, PIs were rich in gray matter. Copyright © 2010 John Wiley & Sons, Ltd. [source]

The influence of the extensional viscosity of very low concentrations of high molecular mass water-soluble polymers on atomisation and droplet impact

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2008
Peter A Williams
BACKGROUND: Water-soluble polymers are increasingly added to herbicide and pesticide formulations at very low concentrations (100,1000 mg L,1) in order to control the spray characteristics, notably to reduce spray drift and influence droplet bounce. The incorporation of polymeric adjuvants improves the efficacy of the spray solutions, thus enabling crop growers to maximise the performance of agrochemical sprays at lower dose rates of active ingredient. It is important to establish a fundamental understanding of how polymers influence the processes involved in droplet deposition. RESULTS: The shear and extensional viscosities of a series of high molecular mass (Mw) poly(acrylamides) (Mw , 106,107) have been determined at very low concentrations (100,1000 mg L,1). The polymer solutions demonstrated typical shear thinning characteristics under shear, and strain hardening behaviour under extension above a critical strain rate. The presence of the polymers was shown to increase the size of droplets produced in atomisation using an agricultural spray nozzle, as measured by laser diffraction. This was attributed to the increase in the extensional viscosity at the strain rates generated under pressure in the spray nozzle and was a function of both polymer concentration and Mw. In addition, the presence of polymer was found to have a significant influence on droplet bounce. CONCLUSIONS: The presence of very low concentrations of high molecular mass poly(acrylamides) significantly influences the size of droplets formed on atomisation and subsequent bounce characteristics. Large extensional viscosities generated above a critical strain rate are responsible for both processes. Copyright © 2008 Society of Chemical Industry [source]

Direct analysis of lipids in mouse brain using electrospray droplet impact/SIMS

Behavioral patterns of drop impingement onto rigid substrates with a wide range of wettability and different surface temperatures

AICHE JOURNAL, Issue 8 2009
Xiying Li
Abstract This article concerns behavioral patterns of droplet impingement onto solid substrates covering a wide range of wettability from hydrophilic to superhydrophobic surfaces heated at different temperatures. For droplet impingement onto partial hydrophobic surfaces (mirror-polished Cu substrate), the maximum heights of receding droplet undergoing a consecutive increment with surface temperature can be explained taking account of Marangoni flow. Also, the relation to predict the increment of droplet heights with surface temperature was manifested in the light of lubrication approximation combined with energy conservation. However, this relation is only valid for droplet impacts onto partial hydrophobic surface, because the recoiling droplet height was observed to be independent of surface temperature for both hydrophilic and superhydrophobic targets. This phenomenon was attributed to inherent wettability accompanying larger contact angle hysteresis for the hydrophilic substrate and to the presence of an adiabatic gas layer between the composite surface and impacting droplet, for the superhydrophobic target. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]

Study of liquid droplets impact on dry inclined surface

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009
Jie Cui
Abstract The impact of droplets on the surface is a common phenomenon. The outcome of a droplet impacting on a solid surface depends on the properties of the liquid, the surface conditions and the kinematics parameters, i.e. velocity and momentum. During the impact process, the phenomenons, such as spread, rebound, often appear. This paper presents the results of an experimental investigation of droplets impacting on inclined solid surface at low velocity. The effects of the impact parameters on the droplet impingement are studied. Measures were performed using a high-speed camera. It has been shown that the impacting droplets spread on the surface until liquid surface tension and viscosity overcame inertial forces, after which they recoiled off the surface. The maximum diameter of a droplet spread was measured. In addition, a further forecasting expression has been obtained through energy model when a droplet impacts on an inclined surface without splashing. It is found that it is in good agreement with experimental value and can well predict the maximum spread diameter. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]