scholarly journals A Comparison of Particle Size Distributions Measured by Microscopic (Feret Diameter) and Laser Diffraction Method. Ground Product of Sr-Ferrite.

2000 ◽  
Vol 13 (1) ◽  
pp. 13-17
Author(s):  
Naoya KOTAKE ◽  
Yusuke HONMA ◽  
Naoyuki TOIDA ◽  
Takahiro MOCHIDUKI ◽  
Ichiro OKA ◽  
...  
Keyword(s):  
Particle Size ◽  
Diffraction Method ◽  
Laser Diffraction ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Feret Diameter

scholarly journals Impact of optical indices on particle size distribution of activated sludge measured by laser diffraction method

2014 ◽  
Vol 21 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Agata Sochan ◽  
Cezary Polakowski ◽  
Grzegorz Łagód
Keyword(s):  
Particle Size ◽  
Refractive Index ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mie Theory ◽  
Diffraction Method ◽  
Laser Diffraction ◽  
Optical Parameters ◽  
Size Distributions ◽  
Particle Size Distributions

Abstract The important factors that strongly influence the particle size distributions measured by the laser diffraction method are the optical parameters of the suspension (refractive index and absorption coefficient). Knowledge of the values of these parameters is necessary for Mie theory. Mie theory is applied for conversion of the intensity of light recorded on detectors into particle size distribution (PSD) of tested material. Both wastewater and activated sludge are mixtures of a variety of elements (mineral or organic, including living organisms). In practice, it is not possible to define clearly the values of the optical parameters, as the composition of the suspension changes over time. The aim of the study was to estimate the impact of assumed values of the optical parameters on particle size distributions obtained. The PSDs of suspensions sampled in different stages of wastewater treatment are the most reproducible when the following optical parameters are defined: absorption coefficients - 1.0 and the refractive index - 1.52.

Comparing multifractal characteristics of soil particle size distributions calculated by Mie and Fraunhofer models from laser diffraction measurements

2021 ◽  
Vol 94 ◽  
pp. 36-48
Author(s):  
María Liliana Darder ◽  
Antonio Paz-González ◽  
Aitor García-Tomillo ◽  
Marcos Lado ◽  
Marcelo German Wilson
Keyword(s):  
Particle Size ◽  
Laser Diffraction ◽  
Soil Particle ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Soil Particle Size

Comparison of soil texture determined by two dispersion units of Mastersizer 2000

2012 ◽  
Vol 26 (1) ◽  
pp. 99-102 ◽  
Author(s):  
A. Sochan ◽  
A. Bieganowski ◽  
M. Ryżak ◽  
R. Dobrowolski ◽  
P. Bartmiński
Keyword(s):  
Particle Size ◽  
Soil Texture ◽  
Clay Fraction ◽  
Laser Diffraction ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Clay Particles ◽  
Fine Clay

Comparison of soil texture determined by two dispersion units of Mastersizer 2000The comparison of particle size distributions measured by sedimentation methods and laser diffraction shows the underestimation of the fine (clay) fraction. This is attributed mainly to the shape of clay particles being different than spherical. The objective of this study was to demonstrate differences in the results of particle size distributions of soils determined with the method of laser diffraction using two different dispersion units of the Malvern Mastersizer 2000.

The duplicity of floc strength

2004 ◽  
Vol 50 (12) ◽  
pp. 63-70 ◽  
Author(s):  
P. Jarvis ◽  
B. Jefferson ◽  
S. Parsons
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Laser Diffraction ◽  
Growth Potential ◽  
Small Scale ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Growth Behaviour ◽  
Different Types ◽  
Floc Strength

The breakage of flocs is dependent upon the strength of the bonds holding the aggregate together. The present work describes the breakage and re-growth behaviour of three different types of floc, these were: 1) coagulant precipitate flocs, 2) turbidity flocs and 3) organic matter flocs. Floc aggregates were exposed to increased levels of shear on a conventional jar tester and the sizes of the flocs were observed dynamically using a laser diffraction instrument. The organic flocs showed most resistance to breakage across the whole range of shears under investigation. The dynamic procedure provided detailed information on particle size distributions (PSD). Large and small scale degradation events could be identified from analysis of the PSD data. All of the flocs under investigation showed little re-growth potential after breakage. The precipitate and organic flocs showed slightly better re-aggregation of the small floc sizes.

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.

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