DROPLET DYNAMICS AFTER IMPACTING ON HYDROPHILIC POWDER BEDS COMPOSED OF UNIFORM AND NON-UNIFORM SIZE PARTICLES

2020 ◽  
Vol 8 (1) ◽  
pp. 11-24
Author(s):  
Wei Xiong ◽  
Ping Cheng ◽  
Zhiyuan Ma ◽  
Xiaojun Quan ◽  
Wei Yao
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.


TAPPI Journal ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 17-23 ◽  
Author(s):  
WANHEE IM ◽  
HAK LAE LEE ◽  
HYE JUNG YOUN ◽  
DONGIL SEO

Preflocculation of filler particles before their addition to pulp stock provides the most viable and practical solution to increase filler content while minimizing strength loss. The characteristics of filler flocs, such as floc size and structure, have a strong influence on preflocculation efficiency. The influence of flocculant systems on the structural characteristics of filler flocs was examined using a mass fractal analysis method. Mass fractal dimensions of filler flocs under high shear conditions were obtained using light diffraction spectroscopy for three different flocculants. A single polymer (C-PAM), a dual cationic polymer (p-DADMAC/C-PAM) and a C-PAM/micropolymer system were used as flocculants, and their effects on handsheet properties were investigated. The C-PAM/micropolymer system gave the greatest improvement in tensile index. The mass fractal analysis showed that this can be attributed to the formation of highly dense and spherical flocs by this flocculant. A cross-sectional analysis of the handsheets showed that filler flocs with more uniform size were formed when a C-PAM/micropolymer was used. The results suggest that a better understanding of the characteristics of preflocculated fillers and their influence on the properties of paper can be gained based on a fractal analysis.


1997 ◽  
Vol 24 (1-3) ◽  
pp. 138-148 ◽  
Author(s):  
Yuji Ikeda ◽  
Nobutaka Tsuchimoto ◽  
N. Kawahara ◽  
Tsuyoshi Nakajima

Mediaevistik ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 450-452
Author(s):  
John M. Jeep

Under the somewhat different, certainly intentionally punning title, Unter Druck: Mitteleuropäische Buchmalerei im Zeitalter Gutenbergs / Under Pressure / Printing […] in the Age of Gutenberg, this volume first appeared in German (Lucerne: Quaternio, 2015) to accompany a series of twelve different exhibitions of largely fifteenth-century book illumination across Central Europe. The exhibitions in Germany, Austria, and Switzerland were held, in part overlapping, from September 2015 – March 2017. They were bookended by exhibits in Vienna and Munich (for the latter, see Bilderwelten. Buchmalerei zwischen Mittelalter und Neuzeit. Katalogband zu den Ausstellungen in der Bayerischen Staatsbibliothek vom 13. April 2016 bis 24. Februar 2017, ed. Jeffrey F. Hamburger et al. Buchmalerei des 15. Jahrhunderts in Mitteleuropa, 3 (Lucerne: Quaternio, 2016). For each of ten somewhat smaller exhibitions a catalogue of uniform size and format was produced; they are, according to the publisher, already out of print. The three editors of the more comprehensive collection, Painting the Page, penned contributions that complement Eberhard König’s study, “Colour for the Black Art,” which traces <?page nr="451"?>the development of ornamentation to the Gutenberg and following printed Bibles. Early printed Bibles, in Latin or in the vernacular, tended only to provide space for initial and marginal, as opposed to full page illumination. These admittedly limited artistic accomplishments often allow for more precise localization of incunabula than other available resources. At the same time, differences and even misunderstandings – such as failure to follow instructions to the illuminator – on occasion lead to fruitful cultural analysis. Finally, printed copies that were never adorned were sometimes in the past thought to be superior, untouched, as it were, by the artistry of the ‘old’ manuscript world. König argues that the study of early printed books, and especially the illuminations they contain, should be celebrated not only as ancillary scholarship, but also as a discipline in its own right.


2012 ◽  
Vol 9 (1) ◽  
pp. 110-115
Author(s):  
L.A. Kovaleva ◽  
R.R. Zinnatullin ◽  
V.N. Blagochinnov ◽  
A.A. Musin ◽  
Yu.I. Fatkhullina ◽  
...  

Some results of experimental and numerical studies of the influence of radio-frequency (RF) and microwave (MW) electromagnetic (EM) fields on water-in-oil emulsions are presented. A detailed investigation of the dependence of the dielectric properties of emulsions on the frequency of the field makes it possible to establish the most effective frequency range of the EM influence. The results of water-in-oil emulsion stability in the RF EM field depending on their dielectric properties are presented. The effect of the MW EM field on the emulsion in a dynamic mode has been studied experimentally. In an attempt to understand the mechanism of emulsion destruction the mathematical model for a single emulsion droplet dynamics in radio-frequency (RF) and microwave (MW) electromagnetic fields is formulated.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 711
Author(s):  
Zdzisław Kaliniewicz ◽  
Dariusz J. Choszcz

Viburnum is a genus of colorful and ornamental plants popular in landscape design on account of their high esthetic appeal. The physical properties of viburnum seeds have not been investigated in the literature to date. Therefore, the aim of this study was to characterize the seeds of selected Viburnum species and to search for potential relationships between their physical attributes for the needs of seed sorting operations. The basic physical parameters of the seeds of six Viburnum species were measured, and the relationships between these attributes were determined in correlation and regression analyses. The average values of the evaluated parameters were determined in the following range: terminal velocity—from 5.6 to 7.9 m s−1, thickness—from 1.39 to 1.87 mm, width—from 3.59 to 6.33 mm, length—from 5.58 to 7.44 mm, angle of external friction—from 36.7 to 43.8°, mass—from 16.7 to 35.0 mg. The seeds of V. dasyanthum, V. lentago and V. sargentii should be sorted in air separators, and the seeds of V. lantana and V. opulus should be processed with the use of mesh screens with round apertures to obtain uniform size fractions. The seeds of V. rhytodophyllum cannot be effectively sorted into batches with uniform seed mass, but they can be separated into groups with similar dimensions.


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