| 1. |
- Di Fatta, G., et al.
(författare)
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Preface
- 2011
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Ingår i: IEEE International Conference on Data Mining. Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 1550-4786. ; , s. xlviii-xlvix
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Ajay, A., et al.
(författare)
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Hot corrosion behavior of solution precursor and atmospheric plasma sprayed thermal barrier coatings
- 2015
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Ingår i: Corrosion Science. - : Elsevier Ltd. - 0010-938X .- 1879-0496. ; 98, s. 271-279
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Tidskriftsartikel (refereegranskat)abstract
- Hot corrosion behavior of solution precursor plasma spray (SPPS) thermal barrier coating (TBC) in molten salt mixtures of 90wt.% Na2SO4+5wt.% V2O5+5wt.% NaCl and 50wt.% Na2SO4+50wt.% V2O5 at 900°C is compared vis-à-vis atmospheric plasma spray (APS) coating. APS TBCs show better hot corrosion resistance than SPPS TBCs in both the salt mixtures. The vertical cracks in SPPS coatings, meant for strain tolerance and high thermal cycling life, serve as channels for transporting salts across the coating to bond coat/top coat interface and accelerate failure. © 2015 Elsevier Ltd.
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| 3. |
- Asik, RM, et al.
(författare)
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Anticancer Potential of L-Histidine-Capped Silver Nanoparticles against Human Cervical Cancer Cells (SiHA)
- 2021
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Ingår i: Nanomaterials (Basel, Switzerland). - : MDPI AG. - 2079-4991. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- This study reports the synthesis of silver nanoparticles using amino acid L-histidine as a reducing and capping agent as an eco-friendly approach. Fabricated L-histidine-capped silver nanoparticles (L-HAgNPs) were characterized by spectroscopic and microscopic studies. Spherical shaped L-HAgNPs were synthesized with a particle size of 47.43 ± 19.83 nm and zeta potential of −20.5 ± 0.95 mV. Results of the anticancer potential of L-HAgNPs showed antiproliferative effect against SiHa cells in a dose-dependent manner with an IC50 value of 18.25 ± 0.36 µg/mL. Fluorescent microscopic analysis revealed L-HAgNPs induced reactive oxygen species (ROS) mediated mitochondrial dysfunction, leading to activation of apoptotic pathway and DNA damage eventually causing cell death. To conclude, L-HAgNPs can act as promising candidates for cervical cancer therapy.
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| 4. |
- Bansal, Namita, et al.
(författare)
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Cell wall-associated transition metals improve alkaline-oxidative pretreatment in diverse hardwoods
- 2016
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 18:5, s. 1405-1415
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Tidskriftsartikel (refereegranskat)abstract
- The responses of four diverse hardwoods (hybrid poplar, silver birch, hybrid aspen, and sugar maple) to alkaline hydrogen peroxide (AHP) pretreated at ambient temperature and pressure were analyzed to gain a deeper understanding of the cell wall properties that contribute to differences in enzymatic hydrolysis efficacy following alkaline-oxidative pretreatment. The enzymatic hydrolysis yields of these diverse hardwoods increased significantly with increasing the cell wall-associated, redox-active transition metal content. These increases in hydrolysis yields were directly correlated with improved delignification. Furthermore, we demonstrated that these improvements in hydrolysis yields could be achieved either through elevated levels of naturally-occurring metals, namely Cu, Fe, and Mn, or by the addition of a homogeneous transition metal catalyst (e.g. Cu 2,2′-bipyridine complexes) capable of penetrating into the cell wall matrix. Removal of naturally-occurring cell wall-associated transition metals by chelation resulted in substantial decreases in the hydrolysis yields following AHP pretreatment, while re-addition of metals in the form of Cu 2,2′-bipyridine complexes and to a limited extent Fe 2,2′-bipyridine complexes prior to pretreatment restored the improved hydrolysis yields. Glycome profiles showed improved extractability of xylan, xyloglucan, and pectin epitopes with increasing hydrolysis yields for the diverse hardwoods subjected to the alkaline-oxidative pretreatment, demonstrating that the strength of association between cell wall matrix polymers decreased as a consequence of improved delignification
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| 5. |
- Biswal, Ajaya K., et al.
(författare)
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Aspen pectate lyase PtxtPL1-27 mobilizes matrix polysaccharides from woody tissues and improves saccharification yield
- 2014
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Ingår i: Biotechnology for Biofuels. - : Springer Science and Business Media LLC. - 1754-6834. ; 7, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Wood cell walls are rich in cellulose, hemicellulose and lignin. Hence, they are important sources of renewable biomass for producing energy and green chemicals. However, extracting desired constituents from wood efficiently poses significant challenges because these polymers are highly cross-linked in cell walls and are not easily accessible to enzymes and chemicals. Results: We show that aspen pectate lyase PL1-27, which degrades homogalacturonan and is expressed at the onset of secondary wall formation, can increase the solubility of wood matrix polysaccharides. Overexpression of this enzyme in aspen increased solubility of not only pectins but also xylans and other hemicelluloses, indicating that homogalacturonan limits the solubility of major wood cell wall components. Enzymatic saccharification of wood obtained from PL1-27-overexpressing trees gave higher yields of pentoses and hexoses than similar treatment of wood from wild-type trees, even after acid pretreatment. Conclusions: Thus, the modification of pectins may constitute an important biotechnological target for improved wood processing despite their low abundance in woody biomass.
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| 6. |
- Crowe, Jacob D., et al.
(författare)
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Identification of developmental stage and anatomical fraction contributions to cell wall recalcitrance in switchgrass
- 2017
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Ingår i: Biotechnology for Biofuels. - : BioMed Central. - 1754-6834. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Heterogeneity within herbaceous biomass can present important challenges for processing feedstocks to cellulosic biofuels. Alterations to cell wall composition and organization during plant growth represent major contributions to heterogeneity within a single species or cultivar. To address this challenge, the focus of this study was to characterize the relationship between composition and properties of the plant cell wall and cell wall response to deconstruction by NaOH pretreatment and enzymatic hydrolysis for anatomical fractions (stem internodes, leaf sheaths, and leaf blades) within switchgrass at various tissue maturities as assessed by differing internode. Results: Substantial differences in both cell wall composition and response to deconstruction were observed as a function of anatomical fraction and tissue maturity. Notably, lignin content increased with tissue maturity concurrently with decreasing ferulate content across all three anatomical fractions. Stem internodes exhibited the highest lignin content as well as the lowest hydrolysis yields, which were inversely correlated to lignin content. Confocal microscopy was used to demonstrate that removal of cell wall aromatics (i.e., lignins and hydroxycinnamates) by NaOH pretreatment was non-uniform across diverse cell types. Non-cellulosic polysaccharides were linked to differences in cell wall response to deconstruction in lower lignin fractions. Specifically, leaf sheath and leaf blade were found to have higher contents of substituted glucuronoarabinoxylans and pectic polysaccharides. Glycome profiling demonstrated that xylan and pectic polysaccharide extractability varied with stem internode maturity, with more mature internodes requiring harsher chemical extractions to remove comparable glycan abundances relative to less mature internodes. While enzymatic hydrolysis was performed on extractives-free biomass, extractible sugars (i.e., starch and sucrose) comprised a significant portion of total dry weight particularly in stem internodes, and may provide an opportunity for recovery during processing. Conclusions: Cell wall structural differences within a single plant can play a significant role in feedstock properties and have the potential to be exploited for improving biomass processability during a biorefining process. The results from this work demonstrate that cell wall lignin content, while generally exhibiting a negative correlation with enzymatic hydrolysis yields, is not the sole contributor to cell wall recalcitrance across diverse anatomical fractions within switchgrass
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| 7. |
- Dom, R., et al.
(författare)
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Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying
- 2012
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Ingår i: Materials research bulletin. - 0025-5408 .- 1873-4227. ; 47:3, s. 562-570
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Tidskriftsartikel (refereegranskat)abstract
- Deposition of pure spinel phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 < pH ≤ 10) were found to favor oxide film formation. The nanostructured films produced under optimized conditions, with 500 mM solution at pH ∼ 8.0, yielded pure cubic phase ZnFe 2O 4 film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of ∼1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications. © 2012 Elsevier Ltd. All rights reserved.
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| 8. |
- Joshi, S. V., et al.
(författare)
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Hybrid Plasma-Sprayed Thermal Barrier Coatings Using Powder and Solution Precursor Feedstock
- 2014
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Ingår i: Journal of thermal spray technology (Print). - 1059-9630 .- 1544-1016. ; 23:4, s. 616-624
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Tidskriftsartikel (refereegranskat)abstract
- A novel approach of hybridizing the conventional atmospheric plasma spraying (APS) technique with the solution precursor plasma spray (SPPS) route to achieve thermal barrier coatings (TBCs) with tailored configurations is presented. Such a hybrid process can be conveniently adopted for forming composite, multi-layered and graded coatings employing simultaneous and/or sequential feeding of solution precursor as well as powder feedstock, yielding distinct TBC microstructures that bear promise to further extend coating durability. TBC specimens generated using conventional APS technique, the SPPS method and through APS-SPPS hybrid processing have been comprehensively characterized for microstructure, phase constitution, hardness and thermal cycling life, and the results were compared to demonstrate the advantages that can ensue from hybrid processing.
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| 9. |
- Joshi, Shrikant V., 1960-, et al.
(författare)
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Hybrid Processing with Powders and Solutions : A Novel Approach to Deposit Composite Coatings
- 2015
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Ingår i: Journal of thermal spray technology (Print). - : Springer. - 1059-9630 .- 1544-1016. ; 24:7, s. 1166-1186
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Tidskriftsartikel (refereegranskat)abstract
- Thermal spraying employing either solution precursor or suspension feedstock offers an exciting opportunity to obtain coatings with microstructures and characteristics that differ vastly compared to those conventionally produced using spray-grade powders. Both solution precursor plasma spray and suspension plasma spray techniques have been explored extensively in recent years for depositing wide ranging ceramic coatings for various functional applications. Encouraged by the properties achieved using the above solution-based feedstocks, a hybrid approach involving dual injection of solutions and powders, either simultaneously or sequentially, has been proposed and demonstrated to yield novel coating architectures. Although prior work on such hybrid processing is very limited, this overview seeks to present the concept, outline associated challenges, and demonstrate its efficacy to realize coatings with exciting and unusual properties using some illustrative examples. © 2015 ASM International
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| 10. |
- Joshi, Shrikant V., 1960-, et al.
(författare)
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New Generation Ceramic Coatings for High-Temperature Applications by Liquid Feedstock Plasma Spraying : Defense, Security, Aerospace and Energy Applications
- 2020
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Ingår i: Handbook of Advanced Ceramics and Composites. - Cham : Springer. - 9783319732558 ; , s. 1-42
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Plasma spraying with liquid feedstock offers an exciting opportunity to obtain coatings with characteristics that are vastly different from those produced using conventional spray-grade powders. The two extensively investigated variants of this technique are suspension plasma spraying (SPS), which utilizes a suspension of fine powders in an appropriate medium, and solution precursor plasma spraying (SPPS), which involves use of a suitable solution precursor that can form the desired particles in situ. The advent of axial injection plasma spray systems in recent times has also eliminated concerns regarding low deposition rates/efficiencies associated with liquid feedstock. The 10–100 μm size particles that constitute conventional spray powders lead to individual splats that are more than an order of magnitude larger compared to those resulting from the fine (approximately 100 nm–2 μm in size) particles already present in suspensions in SPS or formed in situ in SPPS. The distinct characteristics of the resulting coatings are directly attributable to the above very dissimilar splats (“building blocks” for coatings) responsible for their formation. This chapter discusses the salient features associated with SPS and SPPS processing, highlights their versatility for depositing a vast range of ceramic coatings with diverse functional attributes, and discusses their utility, particularly for high-temperature applications through some illustrative examples. A further extension of liquid feedstock plasma processing to enable use of hybrid powder-liquid combinations for plasma spraying is also discussed. This presents a novel approach to explore new material combinations, create various function-dependent coating architectures with multi-scale features, and enable convenient realization of layered, composite, and graded coatings as demonstrated through specific examples.
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