THE EVALUATION OF FOUR PRETREATMENTS USED IN PARTICLE-SIZE DISTRIBUTION ANALYSES

1964 ◽  
Vol 44 (3) ◽  
pp. 345-351 ◽  
Author(s):  
R. Protz ◽  
R. J. St. Arnaud
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Dilute Acid ◽  
Free Lime ◽  
Ph Values ◽  
The Individual ◽  
Suspension Ph

Four methods of soil pretreatment for particle-size distribution analyses compared using 10 Saskatchewan soils. Clay percentages, suspension pH values following shaking, and losses due to various treatments were used to evaluate the individual treatments. The high suspension PH required to obtain complete dispersion may not be achieved if excess acid is used to destroy lime carbonates prior to analysis. Lowering soil PH to 5.5 during pretreatment with dilute acid effectively removes free lime carbonates while still allowing complete dispersion.

Aspects of particle attachment in filtration

2006 ◽  
Vol 6 (4) ◽  
pp. 125-134 ◽  
Author(s):  
J. Kim ◽  
D.F. Lawler
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Granular Media ◽  
Early Stage ◽  
Particle Removal ◽  
Specific Chemical ◽  
Ph Values ◽  
Initial Stage

Granular media filtration is used almost universally as the last particle removal process in conventional water treatment plants, but every particle cannot be removed. Laboratory-scale filtration experiments were performed at a filtration velocity of 5 m/h using spherical glass beads with mean diameter of 0.55 mm as collectors; the 10 cm depth ensured particles would be in the effluent. Particle suspensions (Min-U-Sil 5) with 1.7 μm mean particle size were filtered at pH values of 3.0, 4.0, and 5.0, all above the isoelectric point (near pH 2.0). Zeta potential distribution (ZPD) and particle size distribution (PSD) of influent and effluent particles were measured. More favorable particles, i.e. particles with smaller surface charge, were well attached to the collectors during the early stage of filtration. This selective attachment of the lower charged particles caused the ZPD of the effluent to move to a more negative range. However, the ZPD did not keep moving to a more negative range during later stages of filtration, and this result was thought to be caused by two reasons: ripening effects and detachment of flocs. In the early stages of filtration, particles were captured better at pH 3.0 than at the higher pH values (as expected), but this trend reversed at a cumulative hydraulic loading (CHL) of only 5–10 m3/m2. Particle breakoff apparently occurs as flocs of particles that are initially captured individually, as indicated by the trends for different particle sizes. At pH 3.0, particles in the 3–5 μm range had worse removal after a CHL of 5 m3/m2, whereas removal improved through the entire CHL of 20 m3/m2 for all size particles at pH 4.0. Chemical parameters such as zeta potential can be important during the initial stage of filtration, but their importance can decrease over time depending on the specific chemical conditions. The influent particle size distribution and the removal of certain size particles during the initial stage can significantly influence ripening which, in turn, can influence the overall particle removal efficiency. Better initial particle removal does not necessarily mean better overall particle removal.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution

DENSE SPRAY CORRECTIONS FOR DIFFRACTION-BASED PARTICLE SIZE DISTRIBUTION MEASUREMENTS

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution

Influence of Cementite Particle Size Distribution on Machinability and Tool Life of High Carbon Cr-bearing Steels

1998 ◽  
Vol 84 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Takashi INOUE ◽  
Yuzo HOSOI ◽  
Koe NAKAJIMA ◽  
Hiroyuki TAKENAKA ◽  
Tomonori HANYUDA
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Tool Life ◽  
Cementite Particle ◽  
High Carbon ◽  
Bearing Steels

Study of the microstructure and particles of vanadium (III) oxide, vanadium (V) oxide and lithium aluminate powders

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Vanadium Oxide ◽  
Size Distribution ◽  
Microstructural Analysis ◽  
Coherent Scattering ◽  
Powder Materials ◽  
Lithium Aluminate ◽  
Range Limit ◽  
Oxide Particles

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.

Multi-fractal characteristics of particle size distribution of granular backfilling materials under different loads

2018 ◽  
Vol 60 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Hao Yan ◽  
Jixiong Zhang ◽  
Jiaqi Wang ◽  
Nan Zhou ◽  
Sheng Zhang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fractal Characteristics
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