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Tytuł:
Co(salen)-catalysed oxidation of synthetic lignin-like polymer: O2 effects
Katalizowane Co(salen) utlenianie syntetycznego lignino-podobnego polimeru: efekt O2
Autorzy:
Zhou, X.-F.
Powiązania:
https://bibliotekanauki.pl/articles/52427.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
co(salen) zob.N,N′-bis(salicylidene)ethylenediaminocobalt
N,N′-bis(salicylidene)ethylenediaminocobalt
oxidation
synthetic lignin-like polymer
oxygen
metal catalyst
Opis:
Molecular oxygen (O2) is widely used as an oxidant in catalytic oxidation. This study was part of a biomimetic oxidation targeted at increasing the use of lignin in the production of chemicals through the application of salen transition metal catalysts. In this work, the catalytic performance of a cobalt-Schiff base catalyst Co(salen) in the presence of an oxidant and a ligand, such as pyridine, was analysed using two polymeric lignin model compounds. Oxidation experiments were carried out in alkaline water (pH 11-12) with the use of H2O2 and atmospheric oxygen (1atm) as oxidants. Co(salen) was an active catalyst, increasing the oxidation rate of the S- and G- type phenolic model polymers. In studies with FTIR, C-13 NMR, and GC-MS spectroscopy, the Co(salen)--catalysed oxidation rate was found to be high in the presence of O2. O2 had effects on the activity of the Co(salen), and it was concluded that the rate of the decomposition of the polymer was increased with the addition of O2. The structure of the lignin model polymers also had an effect on their decomposition. In the form of two CH3O-group polymers (S-type lignin model polymer), the depolymerisation decreased. Irrespective of the polymer (both S- and G- type lignin model polymers), the depolymerisation generated benzaldehydes as the main observed products. The model polymer studies were confirmed to be a useful way to obtain information about the reactions occurring during catalytic oxidation.
Co(salen) to kompleks koordynacyjny stanowiący pochodną ligandu salenowego (dis-alicylaloetylenodiaminy) i kobaltu. Jego pochodne znajdują zastosowanie jako katalizatory. Przeprowadzono badania nad biomimetycznym utlenianiem ligniny i modelowych związków lignin z wykorzystaniem kompleksu Co(salen). Stwierdzono, że reakcje utleniania katalizowane kompleksu Co(salen) pozwalają na powstania wartościowych produktów, które umożliwią wykorzystanie ligniny w aspekcie przyszłych zastosowań jako biomasa i biopaliwa. W pracy zastosowano dwa syntetyczne polimery ligninowe typu S i G, jako mode-lowe substraty do dalszych badań nad zachowaniem ligniny w reakcjach utleniania katalizowanych kompleksem Co(salen). Jego katalityczną skuteczność i wpływ O2 analizowano za pomocą spektroskopii FTIR, C-13 NMR i chromatografii GC-MS. Odkryto,że Co(salen) zwiększa stopień utlenienia polimerów typu S i G. Natomiast O2 wpływa na jego aktywność. Stopień rozkładu omawianych dwóch polimerów zwiększa się wraz z dodaniem O2. Struktura polimerów wpływa na ich rozkład. W przypadku polimeru z dwiema grupami CH3O- (typ S) depolimeryzacja zmniejszała się. Niezależnie of typu polimeru (S lub G) w procesie depolimeryzacji tworzyły się znaczne ilości benzaldehydów, jako głównych produktów reakcji, zwłaszcza w obecności O2. Kompleksy Co(salen) wydają się być obiecującymi katalizatorami utleniania dla selektywnych transformacji syntetycznych lignino-podobnych polimerów z wykorzystaniem O2, jako końcowego (ostatecznego) utleniacza. Efekt O2 zwiększają zdolność katalityczną Co(salen)u w reakcji utleniania.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2013, 56, 190
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dissolving lignin components in spent liquor of simple inorganic complex bleaching eucalyptus pulp
Autorzy:
Zhou, X.-F.
Powiązania:
https://bibliotekanauki.pl/articles/52879.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Opis:
Promising results from the catalytic bleaching (Cat-bleaching) of oxygen-delignified hardwood kraft pulp (Eucalyptus urophylla × Eucalyptus grandis) with simple inorganic complexes prompted interest in discovering the soluble lignin components.The dissolved substances can be harmful to the environment and some dissolved substances may also have toxic effects on the environment. For these reasons, study of the the composition and structure of dissolved lignin components are of great importance.This investigation is part of a project on Cat-bleaching to obtain more information regarding the lignin components of bleaching effluents. The Cat-treatments of the pulp were performed at bench scale using simple inorganic complexes composed of (NH4)2S2O8 plus Cu(CH3COO)2 (Cu) or Co(CH3COO)2 (Co). The spent liquors obtained after Cat-bleaching were extracted using chloroform, in portions, and the compounds of interest from both the chloroform extracts were isolated using gravity column chromatography with the aid of the UV technique. The samples were analyzed by spectrometric(FT-IR, HSQC 2D-NMR, GC-MS) methods. The dissolved components extracted from the spent liquors from the Cat-bleaching were confirmed to be structurally similar to lignin. The major constituents extracted by organic solvents were identified as phenols, benzaldehydes, phenylethanones, benzoic acid and benzoic acid ethyl ester, which indicated extensive oxidation reactions on the pulp lignin including Cα–Cβ and alkyl-aryl cleavage in the lignin upon catalytical attack. The 2-methoxy phenol predominated, and its proportion was higher from the Cu-bleaching. But the carbonyl compounds (benzaldehyde + phenylethanone) released from the pulp after Co-bleaching had a higher ratio than those after Cu-bleaching. Identification of these carbonyl compounds from among the dissolved compounds contributed to the relation between lignin oxidation and lignin removal.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2015, 58, 194
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Co(salen) catalysed oxidation of synthetic lignin-like polymer: NaOH effects
Autorzy:
Zhou, X-F
Powiązania:
https://bibliotekanauki.pl/articles/778743.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Co(salen)
catalyst
catalytic oxidation
lignin model polymer
NaOH effect
FTIR
C-13 NMR
GC-MS
Opis:
An attempt has been made to selectively oxidise synthetic lignin-like polymer for fine chemicals. The G- and S-type polymers (G- and S- type lignin model polymers) were synthesized using simple aromatic compounds as starting materials and then oxidised to benzaldehydes by reacting them with Co(salen) catalytic system. The reaction was characterized by measuring the change of the polymer with FTIR, C-13 NMR and GC-MS spectroscopy. The results obtained by the FTIR and C-13 NMR showed that the effects of NaOH were important and higher yield of benzaldehydes characterized by GC-MS in the presence of NaOH in the course of catalytic oxidation of the polymer demonstrated these effects. From the results, the catalyst could suitably be used in green procedures for lignin transformation.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 3; 91-96
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Treatment of bleaching effluent by guanidine phosphate-activated paper mill sludge activated carbon
Autorzy:
Zhou, X.-F.
Powiązania:
https://bibliotekanauki.pl/articles/52312.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
paper mill sludge
activated carbon
bleaching effluent
guanidine phosphate
adsorbable organohalogen
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2017, 60, 200
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combining laccase with Cu(salen) catalysts for oxidation of kraft lignin
Autorzy:
Zhou, X.-F.
Tang, K.
Powiązania:
https://bibliotekanauki.pl/articles/52753.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
laccase
catalysis
oxidation
kraft lignin
monomeric aromatic chemical
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2016, 59, 198
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The degradation of kraft lignin during hydrothermal treatment for phenolics
Autorzy:
Tang, K.
Zhou, X. F.
Powiązania:
https://bibliotekanauki.pl/articles/778789.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
kraft lignin
hydrothermal treatment
low reaction temperature/short time
oil
phenolics
Opis:
Kraft lignin was hydrothermally depolymerized at low temperature/short time in water for producing value-added phenolics. The effects of residence time (15, 60 min) and reaction temperature (130, 180, 230ºC) on yields of oils and phenolic compounds were studied in detail. Total oil yield was found to range between 7% and 10%. The compositions of oils were analyzed by GC-MS to confirm the main compound to be guaiacol (2-methoxy phenol) in the range of 12–55% of oil depending on different reaction conditions. The most interesting was the finding that maximum value of total oil yield (10% of kraft lignin) and guaiacol amount (55% of oil) was obtained at 130ºC/15, 60 min which is a low reaction temperature/short time, while the residual kraft lignins were analyzed by FTIR with respect to the conversion mechanism of kraft lignin by this process.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 3; 24-28
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxidation of a lignin model compound of benzyl-ether type linkage in water with H2O2 under an oxygen atmosphere catalyzed by Co(Salen)
Utlenianie modelowego związku ligniny z typem wiązania benzylowo-eterowego w wodzie z H2O2 w atmosferze tlenu katalizowane Co(Salen)
Autorzy:
Zhou, X.F.
Qin, J.X.
Wang, S.R.
Powiązania:
https://bibliotekanauki.pl/articles/52363.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
oxidation
lignin model compound
benzyl-ether type
linkage
water
oxygen atmosphere
cobalt salen complex
catalytic property
analytical technique
veratrylglycerol-beta-guaiacyl-alpha,gamma-dimethylether
Opis:
The catalytic properties of Cobalt salen? complex in the oxidation of a lignin model compound [veratrylglycerol-β-guaiacyl-α,γ-dimethylether, VGD] have been investigated in order to obtain the mechanistic aspects of the reaction between Co(salen) and VGD under an oxygen atmosphere using hydrogen peroxide as an oxidant. VGD was found to undergo structural changes in response to the catalytic reaction as characterised by different analytical techniques (FT-IR, H-1 NMR and GC-MS), yielding 2-methoxy phenol and biphenyl. A mechanism for the oxidation of VGD was postulated.
Zbadano katalityczne właściwości kompleksu Co(Salen) w utlenianiu modelowego związku ligniny (veratrylglycerol-β-guaiacyl-α,γ-dimetyleter, VGD) w celu określenia mechanicznych aspektów reakcji pomiędzy Co(salen) i VGD w atmosferze tlenu przy zastosowaniu nadtlenku wodoru jako utleniacza. Zaobserwowano, że w VGD zaszły zmiany strukturalne w odpowiedzi na reakcję katalityczną, co przedstawiono za pomocą różnych technik analitycznych (FTIR, H-1 NMR oraz GC-MS). W efekcie otrzymano 2-metoksy fenol i bifenyl.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2011, 54, 186
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Catalytic conversion of kraft lignin using paper-like Co(salen) as an effective catalyst
Autorzy:
Gao, T.-T.
Zhou, X.-F.
Zhu, Z.-L.
Powiązania:
https://bibliotekanauki.pl/articles/52817.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
catalytic conversion
kraft lignin
catalyst paper
phenolic compound
Co(salen) powder
Opis:
Co(salen) powders were homogeneously scattered over a ceramic fibre network to give a catalyst paper and the Co(salen) paper was tested for the oxidative degradation of a kraft lignin using H2O2 as an oxidant. Due to the structural effect of the interconnected 3D-network, the catalyst paper exhibited a higher performance in the oxidation of kraft lignin with a oil yield of 23.27 % than the original Co(salen) powder with an oil yield of 10.63 %, along with excellent recycling performance. 2,6-Dimethoxyphenol (2.32 mg/kg kraft lignin), vanillin (3.80 mg/kg kraft lignin), and syringaldehyde (2.63 mg/kg kraft lignin) were found to be the main products in the oil obtained. In addition, the structural changes in the kraft lignin were also studied during the process. The phenolic compounds were formed through side chain oxidation together with the oxidative cleavage of β-O-4 linkage.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2015, 58, 195
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Catalytic oxidation of lignin to aromatics over salen-porphyrin complex as a biomimetic catalyst
Autorzy:
Lu, X.-J.
Zhou, X.-F.
Zhu, Z.-L.
Sun, Y.
Tang, K.
Lei, F.-H.
Liu, Z.-G.
Wang, T.
Powiązania:
https://bibliotekanauki.pl/articles/52771.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2019, 62, 203
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of combustion and propulsion processes of a new concept gun using a gaseous propellant
Autorzy:
Liu, N.
Deng, F.
Zhou, F.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/279471.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
combustion light gas gun
interior ballistics
combustion and propulsion
Opis:
The combustion light gas gun (CLGG) uses a low molecular weight gas as the propellant to burn, expand and propel the projectile out of the barrel with higher muzzle velocities. In order to better understand the interior ballistic process of CLGG, an multidimensional combustion and flow model for CLGG is established. It contains unsteady Reynolds-averaged Navier-Stokes (RANS) equations, the RNG k-ε two equation turbulence models, and the Eddy-Dissipation Model (EDM) of combustion. Simulation of the interior ballistic process of CLGG is carried out with a propellant of hydrogen and oxygen mixture charged at a particular initial condition. Results show that the spherical front flames spread from the ignition points which divide the flow field as burned and unburned regions in the initial period and expand to the whole flow field subsequently. The filling error of propellants in the chamber will affect the interior ballistic performance, but the impact is relatively small.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 531-541
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of matrine on reducing damage to bovine mammary epithelial cells induced by Staphylococcus aureus alpha-hemolysin
Autorzy:
Feng, F.
Ma, W.W.
Luo, H.X.
Guan, C.P.
Zhou, X.Z.
Powiązania:
https://bibliotekanauki.pl/articles/2087720.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
α-hemolysin
BMECs
matrine
cell damage
Źródło:
Polish Journal of Veterinary Sciences; 2018, 21, 2; 409-413
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative processing of situation awareness for autonomous ships navigation
Autorzy:
Zhou, X. Y.
Liu, Z. J.
Wu, Z. L.
Wang, F. W.
Powiązania:
https://bibliotekanauki.pl/articles/117424.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
autonomous vessel
autonomous ship
autonomous ships navigation
situation awareness (SA)
quantitative processing
navigation safety
remotely controlled vessel
maritime unmanned navigation through intelligence in networks (MUNIN)
Opis:
The first ever attempt at fully autonomous dock-to-dock operation has been tested and demonstrated successfully at the end of 2018. The revolutionary shift is feared to have a negative impact on the safety of navigation and the getting of real-time situation awareness. Especially, the centralized context onboard could be changed to a distributed context. In navigation safety domain, monitoring, control, assessment of dangerous situations, support of operators of decision-making support system should be implemented in real time. In the context of autonomous ships, decision-making processes will play an important role under such ocean autonomy, therefore the same technologies should consist of adequate system intelligence. At the same time, situation awareness is the key element of the decision-making processes. Although there is substantial research on situation awareness measurement techniques, they are not suitable to directly execute quantitative processing for the situation awareness of autonomous ships navigation. Hence, a novel quantitative model of situation awareness is firstly proposed based on the system safety control structure of remotely controlled vessel. The data source is greatly limited, but the main result still indicates that the probability of operator lose adequate situation awareness of the autonomous ship is significantly higher than the conventional ship. Finally, the paper provides a probabilistic theory and model for high-level abstractions of situation awareness to guide future evaluation of the navigation safety of autonomous ships.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 1; 25-31
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Summer distribution patterns of Trichodesmium spp. in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf
Autorzy:
Jiang, Z.
Chen, J.
Zhou, F.
Zhai, H.
Zhang, D.
Yan, X.
Powiązania:
https://bibliotekanauki.pl/articles/47907.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Trichodesmium
Yangtze River
estuary
China Sea
trichome
biogeochemistry
environment parameter
sea surface temperature
salinity
Opis:
To examine the distribution of Trichodesmium relative to physicochemical factors during summer in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf, three cruises were conducted separately in June 2009, July 2011, and August 2009. Trichodesmium species found were T. thiebautii, T. erythraeum, and T. hildebrandtii. The population was dominated by T. thiebautii, which accounted for >85% of the samples found. Most of them were free trichomes. Colonial forms were rarely observed (approximately 10% of our samples), occurring only in offshore waters. The depth integrated abundances of Trichodesmium were 308 × 103, 1709 × 103, and 3448 × 103 trichomes m−2 in June, July, and August, respectively. Trichodesmium was distributed abundantly in the southern or southeastern part of our study area, where nutrients were low and light penetration, temperature, and salinity were high, which were influenced by the Taiwan Warm Current (TWC) and Kuroshio. Trichodesmium was found in low abundance in inshore, eutrophic, low-salinity waters, which were mainly controlled by the Changjiang Diluted Water (CDW) and coastal current. These results suggest that spatiotemporal changes in the summer Trichodesmium distribution correlate highly with the variations in physicochemical properties that are primarily controlled by the TWC, Kuroshio, and CDW. The summer N2 fixation rate of Trichodesmium was estimated at 12.3 μmol N m−2 d−1 in our study area, contributing >50% of biological N2 fixation.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laboratory investigation of self-healing properties on geosynthetic clay liners with flaw
Autorzy:
Zhang, G.-W.
Zhang, H.-Y.
Wang, J.-F.
Zhou, L.
Liu, P.
Jiang, X.
Powiązania:
https://bibliotekanauki.pl/articles/204652.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
landfills
geosynthetic clay liner
self healing
hydraulic conductivity
Opis:
The objective of this paper is to evaluate the self- healing properties of a commercially-available geosynthetic clay liner (GCL) using flexible-wall permeameter. The GCLs are produced by the same factory, but the contents of bentonite are different. Also the hydraulic conductivities (HC) of GCLs with no defect are different. In this study, specimens were completely saturated under the backpressure of 20 kPa before the test. Permeability tests were performed on GCL specimens with penet rating flaw and also on specimens permeated with distilled water and CaCl2 solutions. The test results were presented and discussed. Experimental results showed that the GCL with penetrating flaw did not exhibit complete self-healing in the case of flaw. After 120 days, the hydraulic conductivity increased by approximately an order of magnitude. In addition, CaCl2 solutions had a significant influence on the hydraulic conductivity. The research findings might be of interest to researchers and engineers who design liners for landfills and other liquid containment facilities.
Źródło:
Archives of Environmental Protection; 2015, 41, 1; 53-58
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł

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