Low-temperature alkali lignin depolymerization to functional chemicals

Author(s):  
Komal Saini ◽  
Avnish Kumar ◽  
Bijoy Biswas ◽  
Thallada Bhaskar
2020 ◽  
Vol 4 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Xiuhui Wang ◽  
Yi Luo ◽  
Moriko Qian ◽  
Eika W. Qian

The synergistic effect of ionic liquids and catalysts and a hypothetical mechanism of lignin depolymerization in a flow reactor are elucidated.


Fuel ◽  
2020 ◽  
Vol 281 ◽  
pp. 118799
Author(s):  
Zhe Zhang ◽  
Parikshit Gogoi ◽  
Zhishuai Geng ◽  
Xinliang Liu ◽  
Xu Du

2018 ◽  
Vol 6 (7) ◽  
pp. 9293-9303 ◽  
Author(s):  
Luana Dessbesell ◽  
Zhongshun Yuan ◽  
Mathew Leitch ◽  
Michael Paleologou ◽  
Reino Pulkki ◽  
...  

2018 ◽  
Vol 120 ◽  
pp. 25-33 ◽  
Author(s):  
Jiongjiong Li ◽  
Jizhi Zhang ◽  
Shifeng Zhang ◽  
Qiang Gao ◽  
Jianzhang Li ◽  
...  

2019 ◽  
Vol 33 (9) ◽  
pp. 8694-8701 ◽  
Author(s):  
Jun Ye ◽  
Minghao Zhou ◽  
Jiaping Zhao ◽  
Haihong Xia ◽  
Junming Xu ◽  
...  

Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.


Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.


Author(s):  
Gert Ehrlich

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.


Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Eugene L. Vigil

Investigators have long realized the potential advantages of using a low temperature (LT) stage to examine fresh, frozen specimens in a scanning electron microscope (SEM). However, long working distances (W.D.), thick sputter coatings and surface contamination have prevented LTSEM from achieving results comparable to those from TEM freeze etch. To improve results, we recently modified techniques that involve a Hitachi S570 SEM, an Emscope SP2000 Sputter Cryo System and a Denton freeze etch unit. Because investigators have frequently utilized the fractured E face of the plasmalemma of yeast, this tissue was selected as a standard for comparison in the present study.In place of a standard specimen holder, a modified rivet was used to achieve a shorter W.D. (1 to -2 mm) and to gain access to the upper detector. However, the additional height afforded by the rivet, precluded use of the standard shroud on the Emscope specimen transfer device. Consequently, the sample became heavily contaminated (Fig. 1). A removable shroud was devised and used to reduce contamination (Fig. 2), but the specimen lacked clean fractured edges. This result suggested that low vacuum sputter coating was also limiting resolution.


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