scholarly journals YBCO Superconductor Wire based on IBAD-Textured Templates and RCE of YBCO: Process Economics

2012 ◽  
Vol 36 ◽  
pp. 1440-1444 ◽  
Author(s):  
Vladimir Matias ◽  
Robert H. Hammond
Keyword(s):  
Ybco Superconductor ◽  
Process Economics ◽  
Superconductor Wire

scholarly journals In situ measurements of oxidation–reduction potential and hydrogen peroxide concentration as tools for revealing LPMO inactivation during enzymatic saccharification of cellulose

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Adnan Kadić ◽  
Anikó Várnai ◽  
Vincent G. H. Eijsink ◽  
Svein Jarle Horn ◽  
Gunnar Lidén
Keyword(s):  
Reduction Potential ◽  
Enzymatic Saccharification ◽  
The State ◽  
Enzyme Inactivation ◽  
Ex Situ ◽  
Process Economics ◽  
Complete Inactivation ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

Abstract Background Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. Results Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation–reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. Conclusion Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation–reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.

scholarly journals Identification of the major fermentation inhibitors of recombinant 2G yeasts in diverse lignocellulose hydrolysates

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gert Vanmarcke ◽  
Mekonnen M. Demeke ◽  
Maria R. Foulquié-Moreno ◽  
Johan M. Thevelein
Keyword(s):  
Second Generation ◽  
Industrial Process ◽  
Superior Performance ◽  
Fermentation Inhibitors ◽  
Inhibitor Tolerance ◽  
Xylose Consumption ◽  
Process Economics ◽  
Partial Inhibition ◽  
Second Generation Bioethanol ◽  
Lignocellulose Hydrolysates

Abstract Background Presence of inhibitory chemicals in lignocellulose hydrolysates is a major hurdle for production of second-generation bioethanol. Especially cheaper pre-treatment methods that ensure an economical viable production process generate high levels of these inhibitory chemicals. The effect of several of these inhibitors has been extensively studied with non-xylose-fermenting laboratory strains, in synthetic media, and usually as single inhibitors, or with inhibitor concentrations much higher than those found in lignocellulose hydrolysates. However, the relevance of individual inhibitors in inhibitor-rich lignocellulose hydrolysates has remained unclear. Results The relative importance for inhibition of ethanol fermentation by two industrial second-generation yeast strains in five lignocellulose hydrolysates, from bagasse, corn cobs and spruce, has now been investigated by spiking higher concentrations of each compound in a concentration range relevant for industrial hydrolysates. The strongest inhibition was observed with industrially relevant concentrations of furfural causing partial inhibition of both D-glucose and D-xylose consumption. Addition of 3 or 6 g/L furfural strongly reduced the ethanol titer obtained with strain MD4 in all hydrolysates evaluated, in a range of 34 to 51% and of 77 to 86%, respectively. This was followed by 5-hydroxymethylfurfural, acetic acid and formic acid, for which in general, industrially relevant concentrations caused partial inhibition of D-xylose fermentation. On the other hand, spiking with levulinic acid, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid or vanillin caused little inhibition compared to unspiked hydrolysate. The further evolved MD4 strain generally showed superior performance compared to the previously developed strain GSE16-T18. Conclusion The results highlight the importance of individual inhibitor evaluation in a medium containing a genuine mix of inhibitors as well as the ethanol that is produced by the fermentation. They also highlight the potential of increasing yeast inhibitor tolerance for improving industrial process economics.

Damping Characteristics of a Magnet Oscillating above a YBCO Superconductor

1998 ◽  
Vol 37 (Part 1, No. 7A) ◽  
pp. 3961-3964 ◽  
Author(s):  
Muneo Futamura ◽  
Takeshi Maeda ◽  
Hajime Konishi
Keyword(s):  
Ybco Superconductor ◽  
Damping Characteristics

Study of Cu Absorption Edge of YBCO Superconductor by X-Ray Powder Diffraction Method

1995 ◽  
Vol 64 (9) ◽  
pp. 3336-3342 ◽  
Author(s):  
Makoto Nakaura ◽  
Tetsuya Ozawa ◽  
Kunio Saiga ◽  
Shintaro Kumazawa ◽  
Hiroyuki Katoh ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Absorption Edge ◽  
Diffraction Method ◽  
Ybco Superconductor ◽  
X Ray

Optimization of Nb3SnCu superconductor wire prepared by the in situ process

1981 ◽  
Vol 29 (11) ◽  
pp. 1791-1796 ◽  
Author(s):  
J.J. Sue ◽  
J.D. Verhoeven ◽  
E.D. Gibson ◽  
J.E. Ostenson ◽  
D.K. Finnemore
Keyword(s):  
Superconductor Wire

The ecological impact of membrane-based extraction of phenolic compounds – a life cycle assessment study

2010 ◽  
Vol 62 (4) ◽  
pp. 915-919 ◽  
Author(s):  
C. Bayer ◽  
M. Follmann ◽  
T. Melin ◽  
T. Wintgens ◽  
K. Larsson ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Phenolic Compounds ◽  
Ecological Impact ◽  
Porous Membrane ◽  
Aqueous Fluid ◽  
Reactive Extraction ◽  
Molecular Weights ◽  
Process Economics ◽  
Process Implementation

Many phenolic compounds show high boiling points, low molecular weights, moderate polarities or high toxicities. Therefore, conventional wastewater treatment is limited or expensive. Recycling of the separated compounds is often not possible. But, if liquid-liquid reactive extraction is linked to a non-porous membrane, some or all of the above mentioned limitations may be overcome. The key element is a composite membrane with a dense, hydrophobic top layer which avoids the mixing of the two aqueous fluid streams. The dilute phenol stream is one of them, the other is caustic soda as stripping solvent. Since the basics of this technology have been discussed before, the scope of this study is to facilitate process implementation and integration. To this end, a life cycle assessment framework is used to identify the optimal equipment size for the treatment of wastewater that may, for example, originate from the production of polycarbonate. Limiting for this application is not the environmental performance though, but most likely process economics.

YBCO superconductor added with one-dimensional TiO2 nanostructures: Frequency dependencies of AC susceptibility, FC-ZFC magnetization, and pseudo-gap studies

2021 ◽  
pp. 160887
Author(s):  
E. Hannachi ◽  
Y. Slimani ◽  
Ahmed T. Okasha ◽  
Ghulam Yasin ◽  
Munawar Iqbal ◽  
...  
Keyword(s):  
Ac Susceptibility ◽  
Ybco Superconductor ◽  
One Dimensional ◽  
Tio2 Nanostructures

Drift of levitated YBCO superconductor induced by both a variable magnetic field and a vibration

1992 ◽  
Vol 195 (1-2) ◽  
pp. 41-46 ◽  
Author(s):  
A.N. Terentiev ◽  
A.A. Kuznetsov
Keyword(s):  
Magnetic Field ◽  
Variable Magnetic Field ◽  
Ybco Superconductor

scholarly journals Value-Added Products from Urea Glycerolysis Using a Heterogeneous Biosolids-Based Catalyst

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 373 ◽  
Author(s):  
Mattia Bartoli ◽  
Chengyong Zhu ◽  
Michael Chae ◽  
David Bressler
Keyword(s):  
Weight Ratio ◽  
Value Added ◽  
Economic Feasibility ◽  
Biodiesel Production ◽  
Wastewater Management ◽  
Thermal Hydrolysis ◽  
Process Economics ◽  
Air Stream ◽  
Increasing Temperature ◽  
Value Added Products

Although thermal hydrolysis of digested biosolids is an extremely promising strategy for wastewater management, the process economics are prohibitive. Here, a biosolids-based material generated through thermal hydrolysis was used as a catalyst for urea glycerolysis performed under several conditions. The catalytic system showed remarkable activity, reaching conversion values of up to 70.8 ± 0.9% after six hours, at 140 °C using a catalyst/glycerol weight ratio of 9% and an air stream to remove NH3 formed during the process. Temperature played the most substantial role among reaction parameters; increasing temperature from 100 °C to 140 °C improved conversion by 35% and glycidol selectivity by 22%. Furthermore, the catalyst retained good activity even after the fourth catalytic run (conversion rate of 56.4 ± 1.3%) with only a slight decrease in glycidol selectivity. Thus, the use of a biosolids-based catalyst may facilitate conversion of various glycerol sources (i.e., byproduct streams from biodiesel production) into value-added products such as glycidol, and may also improve the economic feasibility of using thermal hydrolysis for treatment of biosolids.

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