Nitration of lignin isolated from spruce wood by mechanical grinding

1966 ◽  
Vol 2 (1) ◽  
pp. 49-53
Author(s):  
N. N. Shorygina ◽  
N. P. Mikhailov ◽  
B. V. Lopatin
Keyword(s):  
Mechanical Grinding ◽  
Spruce Wood

Inhomogeneities in the Chemical Structure of Spruce Lignin

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 165-170 ◽  
Author(s):  
H. Önnerud ◽  
G. Gellerstedt
Keyword(s):  
Chemical Structure ◽  
Kraft Pulp ◽  
Periodate Oxidation ◽  
Middle Lamella ◽  
Size Exclusion ◽  
Thermomechanical Pulp ◽  
Normal Wood ◽  
Mechanical Grinding ◽  
Spruce Wood ◽  
Exclusion Chromatography

Summary Thioacidolysis, periodate oxidation and size exclusion chromatography (SEC) were used for the analysis of spruce lignin samples. The standard thioacidolysis method was modified by including a pre-swelling of the lignocellulosic sample before the reaction, and this gave a higher yield of monomer products. Middle lamella and compression wood lignin was found to contain a larger amount of oligomers after thioacidolysis than normal wood lignin. Analysis by thioacidolysis of a thermomechanical pulp (TMP) revealed that approximately 10% of the β-O-4 structures in the lignin were cleaved due to the mechanical grinding effect. From kraft pulp, the mixture of thioacidolysis products contains a major fraction having a considerably larger molecular mass than the products from spruce wood and TMP. The structure of this material is still unknown.

Microstructure of mechanically alloyed and hot-pressed Al5CuZr2

1990 ◽  
Vol 48 (4) ◽  
pp. 970-971
Author(s):  
T. E. Mitchell ◽  
P. B. Desch ◽  
R. B. Schwarz
Keyword(s):  
Mechanical Alloying ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Rapid Quenching ◽  
Hardened Steel ◽  
Alloyed Powder ◽  
Ion Milling ◽  
Mechanical Grinding ◽  
Mechanically Alloyed ◽  
Steel Container

Al3Zr has the highest melting temperature (1580°C) among the tri-aluminide intermetal1ics. When prepared by casting, Al3Zr forms in the tetragonal DO23 structure but by rapid quenching or by mechanical alloying (MA) it can also be prepared in the metastable cubic L12 structure. The L12 structure can be stabilized to at least 1300°C by the addition of copper and other elements. We report a TEM study of the microstructure of bulk Al5CuZr2 prepared by hot pressing mechanically alloyed powder.MA was performed in a Spex 800 mixer using a hardened steel container and balls and adding hexane as a surfactant. Between 1.4 and 2.4 wt.% of the hexane decomposed during MA and was incorporated into the alloy. The mechanically alloyed powders were degassed in vacuum at 900°C. They were compacted in a ram press at 900°C into fully dense samples having Vickers hardness of 1025. TEM specimens were prepared by mechanical grinding followed by ion milling at 120 K. TEM was performed on a Philips CM30 at 300kV.

Facile preparation of nanofiller-paper using mixed office paper without deinking

TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU
Keyword(s):  
Cellulose Nanofibrils ◽  
Ash Content ◽  
Raw Material ◽  
Mechanical Grinding ◽  
Microscope Imaging ◽  
Facile Preparation ◽  
Electron Microscope Imaging ◽  
Thermal Stability Of ◽  
Scanning Electron ◽  
Office Paper

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.

Hydriding and Dehydriding Reactions of Mg-xTaF5 (x=0, 5, and 10) Prepared via Reactive Mechanical Grinding

2014 ◽  
Vol 52 (11) ◽  
pp. 957-962 ◽  
Author(s):  
Myoung Youp Song ◽  
Young Jun Kwak ◽  
Seong Ho Lee ◽  
Hye Ryoung Park
Keyword(s):  
Mechanical Grinding

DNA Inspirited Rational Construction of Nonconventional Luminophores with Efficient and Color-Tunable Afterglow

2020 ◽  
Author(s):  
Yunzhong Wang ◽  
Saixing Tang ◽  
Yating Wen ◽  
Shuyuan Zheng ◽  
Bing Yang ◽  
...  
Keyword(s):  
Rational Design ◽  
Room Temperature ◽  
Double Helix ◽  
Mechanical Grinding ◽  
Room Temperature Phosphorescence ◽  
Color Tunable ◽  
Potential Applications ◽  
Rational Construction ◽  
Double Helix Structure ◽  
Made In

<div>Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive </div><div>due to its fundamental importance and potential applications in molecular imaging, </div><div>sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in </div><div>obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. </div><div>The origin of color-tunable p-RTP and the rational design of such luminogens, </div><div>particularly those with explicit structure and molecular packing, remain challenging. </div><div>Noteworthily, nonconventional luminophores without significant conjugations generally </div><div>possess excitation-dependent photoluminescence (PL) because of the coexistence of </div><div>diverse clustered chromophores6,8, which strongly implicates the possibility to achieve </div><div>color-tunable p-RTP from their molecular crystals assisted by effective intermolecular </div><div>interactions. Here, inspirited by the highly stable double-helix structure and multiple </div><div>hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on </div><div>hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP </div><div>from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP </div><div>efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are </div><div>resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, </div><div>color-tunable and highly efficient p-RTP render the luminophores promising for varying </div><div>applications. These findings provide mechanism insights into the origin of color-tunable </div><div>p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div>

Influence of mechanical grinding on Tc in the Bi base superconductor.

1994 ◽  
Vol 6 (1) ◽  
pp. 31
Author(s):  
Hiroko Yamamoto ◽  
Kouji Ishizuka ◽  
Kazuya Oguri ◽  
Yoshitake Nishi
Keyword(s):  
Mechanical Grinding
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