Environmental responses on the surface of polyurethane-based graft copolymers having uniform size polyether and polyamine segments

Langmuir ◽  
1991 ◽  
Vol 7 (11) ◽  
pp. 2860-2865 ◽  
Author(s):  
Yasuyuki. Tezuka ◽  
Mami. Yoshino ◽  
Kiyokazu. Imai
Keyword(s):  
Graft Copolymers ◽  
Uniform Size ◽  
Environmental Responses

Surface formation and environmental responses on polyurethane-polystyrene graft copolymers

1995 ◽  
Vol 7 (3) ◽  
pp. 283-291 ◽  
Author(s):  
Yasuyuki Tezuka ◽  
Akitoshi Araki ◽  
Tomoo Shiomi
Keyword(s):  
Contact Angle ◽  
Graft Copolymer ◽  
Graft Copolymers ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
The Other ◽  
Environmental Response ◽  
Uniform Size ◽  
Environmental Responses ◽  
Measurable Change

The surfaces of polyurethane (PU)-polystyrene (PS) graft copolymers having a defined content of uniform-size polystyrene graft segments were studied in both dry and wet states. XPS inspection of PU-PS graft copolymer film samples indicated the enrichment of the PS component at the surface in the dry state. The sample films were then immersed in water, and the environmental response at the surface was examined by means of a contact angle measurement using a CCI4 in water technique. The contact angle underwent a slow, but measurable change from one near to that of the PS homopolymer toward that of the PU homopolymer within a 3 h period for the graft copolymer samples annealed at 80 C. On the other hand, the contact angle remained close to that of the PU homopolymer within a 3 h period for samples annealed at 120'C.

Synthesis of polyurethane-based graft copolymers with uniform-size polyether and polyamine segments

Polymer ◽  
1990 ◽  
Vol 31 (11) ◽  
pp. 2207-2213 ◽  
Author(s):  
Hideki Kazama ◽  
Michiaki Hoshi ◽  
Hiroshige Nakajima ◽  
Daniel Horák ◽  
Yasuyuki Tezuka ◽  
...  
Keyword(s):  
Graft Copolymers ◽  
Uniform Size

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

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.

Plant peptide hormone signalling

2015 ◽  
Vol 58 ◽  
pp. 115-131 ◽  
Author(s):  
Ayane Motomitsu ◽  
Shinichiro Sawa ◽  
Takashi Ishida
Keyword(s):  
Communication Systems ◽  
Cell Communication ◽  
Peptide Hormone ◽  
Peptide Hormones ◽  
Target Cells ◽  
Signalling Molecules ◽  
Receptor Complexes ◽  
Environmental Responses ◽  
Plant Life Cycle ◽  
Multicellular Organisms

The ligand–receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone–receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

Structure characterization of ground calcium carbonate flocs by fractal analysis and their effects on handsheet properties

TAPPI Journal ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 17-23 ◽  
Author(s):  
WANHEE IM ◽  
HAK LAE LEE ◽  
HYE JUNG YOUN ◽  
DONGIL SEO
Keyword(s):  
Fractal Analysis ◽  
Structural Characteristics ◽  
Fractal Dimensions ◽  
Strength Loss ◽  
Structure Characterization ◽  
Uniform Size ◽  
Cross Sectional ◽  
Floc Size ◽  
Mass Fractal ◽  
Handsheet Properties

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.

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
Keyword(s):  
Uniform Size ◽  
Droplet Dynamics

Painting the Page in the Age of Print: Central European Manuscript Illumination of the Fifteenth Century, ed. Jeffrey F. Hamburger, Robert Suckale, and Gude Suckale-Redlefsen, trans. David Sánchez Text · Image · Context: Studies in Medieval Manuscript Illumination, 4 Studies and Texts 208. Toronto: Pontifical Institute of Mediaeval Studies, 2018, pp. XXXIII, 329.

Mediaevistik ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 450-452
Author(s):  
John M. Jeep
Keyword(s):  
Fifteenth Century ◽  
Cultural Analysis ◽  
Manuscript Illumination ◽  
Uniform Size ◽  
Medieval Manuscript ◽  
The Past ◽  
Comprehensive Collection ◽  
Printed Books ◽  
Black Art ◽  
Image Context

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.

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