scholarly journals Parametric modelling of magnetic fine particle systems: the role of single domain particle size distributions and magnetic anisotropy

2005 ◽  
Vol 17 ◽  
pp. 1-6 ◽  
Author(s):  
S R Hoon ◽  
D B Lambrick
Keyword(s):  
Particle Size ◽  
Magnetic Anisotropy ◽  
Fine Particle ◽  
Particle Systems ◽  
Single Domain ◽  
Parametric Modelling ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Single Domain Particle

Textural properties of regoliths on vegetated steep slopes in upland regions, Scotland

1986 ◽  
Vol 77 (3) ◽  
pp. 241-250 ◽  
Author(s):  
J. L. Innes
Keyword(s):  
Particle Size ◽  
Early Stage ◽  
Probability Distributions ◽  
Textural Properties ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Normal Probability ◽  
Log Normal ◽  
Steep Slopes

ABSTRACTThe textural properties of many sediments provide a good indication of their provenance, but surprisingly little information is available on the transitional stages between the breakdown of a rock and the incorporation of the material into a fluvial sediment. These transitional stages are important as certain fractions (particularly the finer ones) may be selectively removed. Regoliths developed on steep slopes represent an early stage in the debris cascade and they are here examined in detail to assess the role of parent lithology on the textural properties of the regolith. There are substantial variations between lithologies, although the majority of regoliths are dominated by coarser fractions and are poorly sorted. Most particle size distributions show some degree of fit to both log-normal probability distributions and Rosin distributions. Differences from these can be ascribed to the processes operating on steep slopes, particularly the influx of sand- and silt-sized material by colluvial processes and the removal of clay-sized material by leaching. The regoliths form a distinct facies type which may be recognisable in the geological record.

scholarly journals Tuning Aerosol Particle Size Distribution of Metered Dose Inhalers Using Cosolvents and Surfactants

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Imran Y. Saleem ◽  
Hugh D. C. Smyth
Keyword(s):  
Particle Size ◽  
Fine Particle ◽  
Laser Diffraction ◽  
Particle Sizes ◽  
Size Distributions ◽  
Metered Dose Inhalers ◽  
Particle Size Distributions ◽  
Metered Dose ◽  
Aerosol Particle Size ◽  
Median Particle

Objectives.The purpose of these studies was to understand the influence of cosolvent and surfactant contributions to particle size distributions emitted from solution metered dose inhalers (pMDIs) based on the propellant HFA 227.Methods.Two sets of formulations were prepared: (a) pMDIs-HFA 227 containing cosolvent (5–15% w/w ethanol) with constant surfactant (pluronic) concentration and (b) pMDIs-HFA 227 containing surfactant (0–5.45% w/w pluronic) with constant cosolvent concentration. Particle size distributions emitted from these pMDIs were analyzed using aerodynamic characterization (inertial impaction) and laser diffraction methods.Results. Both cosolvent and surfactant concentrations were positively correlated with median particle sizes; that is, drug particle size increased with increasing ethanol and pluronic concentrations. However, evaluation of particle size distributions showed that cosolvent caused reduction in the fine particle mode magnitude while the surfactant caused a shift in the mode position. These findings highlight the different mechanisms by which these components influence droplet formation and demonstrate the ability to utilize the different effects in formulations of pMDI-HFA 227 for independently modulating particle sizes in the respirable region.Conclusion. Potentially, the formulation design window generated using these excipients in combination could be used to match the particle size output of reformulated products to preexisting pMDI products.

scholarly journals The Role of Particle Size in Producing the F- Coronal Scattered Brightness

1996 ◽  
Vol 150 ◽  
pp. 349-352
Author(s):  
R.M. MacQueen ◽  
W.C. Davidson ◽  
I. Mann
Keyword(s):  
Particle Size ◽  
Mie Theory ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Interplanetary Dust Particles ◽  
Infrared Observations ◽  
Flux Measurements

AbstractMotivated by new infrared observations, we examine the contribution of various size intervals of interplanetary dust particles to visible and infrared scattered radiances of the solar F-corona, employing Mie theory and particle size distributions based upon differing interpretations of lunar microcrater evidence and interplanetary flux measurements.

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