scholarly journals Microwave assisted pyrolysis of Kraft lignin in single mode high-Q resonant cavities: Degradation kinetics, product chemical composition, and numerical modeling

2021 ◽  
Vol 230 ◽  
pp. 113754
Author(s):  
Divine B. Nde ◽  
Pranjali D. Muley ◽  
Cristina M. Sabliov ◽  
Sue E. Nokes ◽  
Dorin Boldor
Keyword(s):  
Numerical Modeling ◽  
Chemical Composition ◽  
Degradation Kinetics ◽  
Single Mode ◽  
Kraft Lignin ◽  
Resonant Cavities ◽  
High Q ◽  
Microwave Assisted

scholarly journals Microwave Assisted Extraction and Pressurized Liquid Extraction of Sulfated Polysaccharides from Fucus virsoides and Cystoseira barbata

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1481
Author(s):  
Ana Dobrinčić ◽  
Sandra Pedisić ◽  
Zoran Zorić ◽  
Mladenka Jurin ◽  
Marin Roje ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Chemical Composition ◽  
Liquid Extraction ◽  
Pressurized Liquid Extraction ◽  
Sulfate Group ◽  
Sulfated Polysaccharides ◽  
Microwave Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Cystoseira Barbata

Sulfated polysaccharide fucoidan isolated from brown algae shows a wide range of biological activities that are significantly dependent on its chemical composition, which is closely related to the applied technique and extraction parameters. Therefore, the objective of this study was to evaluate the influence of microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) parameters (solvent, temperature, time, and number of cycles) on the Fucus virsoides and Cystoseira barbata polysaccharide yield (%PS) and chemical composition (total sugar, fucose, and sulfate group). The optimal MAE parameters that resulted in the highest polysaccharide extraction from F. virsoides and C. barbata were 0.1 M H2SO4 for 10 min at 80 °C, while the optimal PLE parameters were 0.1 M H2SO4, for two cycles of 15 min at 140 °C. Furthermore, the %PS, chemical structure, molecular properties, and antioxidant activity of the F. virsoides and C. barbata polysaccharide extracts obtained with MAE, PLE, and conventional extraction (CE) performed under previously determinate optimal conditions were compared. PLE resulted in a significantly higher %PS from F. virsoides, while for C. barbata, a similar yield was achieved with CE and PLE, as well as CE and MAE, for both algae. Furthermore, the polysaccharides obtained using PLE had the highest polydispersity index, fucose, and sulfate group content, and the lowest uronic acid content; however their antioxidant activity was lower.

Fabrication and spectral characterizations of high Q asymmetric resonant cavities

2015 ◽  
Vol 355 ◽  
pp. 269-273 ◽  
Author(s):  
Jun Tang ◽  
Jianhua Liu ◽  
Chenglong Shang ◽  
Chengfeng Xie ◽  
Hao Guo ◽  
...  
Keyword(s):  
Resonant Cavities ◽  
High Q ◽  
Spectral Characterizations

scholarly journals Chemical composition and in sacco ruminal degradation of tropical trees rich in condensed tannins

2013 ◽  
Vol 58 (No. 4) ◽  
pp. 176-192 ◽  
Author(s):  
Z. Belachew ◽  
K. Yisehak ◽  
T. Taye ◽  
G.P.J. Janssens
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Dry Matter ◽  
Soluble Fraction ◽  
Degradation Kinetics ◽  
Condensed Tannin ◽  
Chemical Constituent ◽  
Crude Fibre ◽  
Plant Parts ◽  
In Sacco

The study was aimed at determining the chemical composition, in sacco ruminal dry matter and organic matter degradability of leaves and fruits of tropical condensed tannin rich multipurpose tree species (MPTS). The MPTS studied were Ekebergia capenesis, Ficus sycomorus, Maesa lanceolata, and Rhus glutinosa. Chemical composition of dry matter (DM), crude protein (CP), crude ash (CA), ether extract (EE), crude fibre (CF), neutral detergent fibre (NDF), non-fibre carbohydrates (NFC), and condensed tannin (CT) was determined. In sacco rumen degradability was measured using three rumen fistulated Holstein Friesian-Boran cross steers at 0, 6, 12, 24, 48, 72, and 96 h. The DM and organic matter (OM) degradability data were fitted to the equation Y = a + b(1 &ndash; e<sup>&ndash;ct</sup>). The values for each chemical constituent ranged 5.43&ndash;11.49% (CA), 7.97&ndash;17.06% (CP), 1.57&ndash;31% (EE), 12.20&ndash;27.5% (CF), 5.84&ndash;39.30% (NFC), and 7.2&ndash;16.72% (CT). Ekebergia capensis leaves had the greatest values for slowly degradable fraction (b), effective degradability (ED), and rate of degradation (c) in DM (P &lt; 0.001) whereas E. capensis fruit had significantly the greatest soluble fraction (a), potential degradability (b), and effective degradability (ED) values as compared to the a, PD, and ED values in the fruits of other plants(P &lt; 0.001). Yet in OM degradation kinetics, the greatest and least values of potential degradability (PD) were recorded for F. sycomorus (89.89%) and E. capensis (55.90%) leaves (P &lt; 0.001). Similar to the rapidly soluble fraction a, ED was found to be the greatest in fruits as compared to leaves of the plants (P &lt; 0.001). Generally variation of plant parts led to significant differences in chemical composition, DM, and OM degradability and the degradable parameters. The leaves and fruits recorded more than 60% DM and OM degradability at 24 h, which implied that they were all greatly degradable in the rumen.

Microwave-assisted selective acetylation of Kraft lignin: Acetic acid as a sustainable reactant for lignin valorization

2020 ◽  
Vol 164 ◽  
pp. 1536-1544
Author(s):  
Davi Rabelo de Oliveira ◽  
Francisco Avelino ◽  
Selma Elaine Mazzetto ◽  
Diego Lomonaco
Keyword(s):  
Acetic Acid ◽  
Kraft Lignin ◽  
Lignin Valorization ◽  
Microwave Assisted

scholarly journals An extremely high ‘Q’ueue value applied to seismological meetings

1988 ◽  
Vol 123 ◽  
pp. 585-585
Author(s):  
Keyword(s):  
Density Fluctuations ◽  
Number Density ◽  
Oscillation Spectrum ◽  
Resonant Cavities ◽  
Future Studies ◽  
High Q ◽  
Long Period ◽  
Fabry Perot ◽  
Solar Type ◽  
Propagation Velocities

Recent observations of the mysterious astronomical body IAU 123 indicate that the ‘Q’ueue value for astronomy symposia can approach 100–120, with very rapid growth and slow exponential decay. Number density fluctuations, with a frequency of 11.56 μHz and extreme phase coherence have been detected outside the main cafeteria. The long period and high ‘Q’ suggest that this may be represented by a g-mode of low radial order.A stabilized Fabry-Perot etalon has been used to measure the low-level motions, with propagation velocities of order 0.01 cm s−1. Although this is well below the local Alfvén speed, there can still arise significant shock effects (e.g. upon discovery of liver loaf as the main course).The observed cafeteria oscillation spectrum is still incomplete. For instance, if ice cream were offered at the end of the line, we would expect to detect the well-known ‘a la’-mode predicted by Baskin and Robbins.We hope that future studies of astronomical Q's may lead to a better understanding of solar-type astronomers' resonant cavities.

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