Search results for "oxidation"
showing 10 items of 1913 documents
Elektroutlenianie odpadowego syntetycznego oleju silnikowego w wodnym roztworze H2SO4
2017
W pracy przedstawiono badania nad możliwością wykorzystania odpadowego syntetycznego oleju silnikowego do bezpośredniego wytwarzania energii elektrycznej. Pomiary przeprowadzono w zakresie temperatur 293–333 K. Obejmowały one elektroutlenianie emulsji odpadowego (zużytego) syntetycznego oleju silnikowego na elektrodzie platynowej w wodnym roztworze H2SO4. Do wytworzenia emulsji wykorzystano niejonowy środek powierzchniowo czynny Syntanol DS-10. Maksymalna uzyskana gęstość prądu wyniosła 22 mA/cm2 (dla temp. 333 K). Wykazano więc, że istnieje możliwość bezpośredniego wytwarzania prądu elektrycznego z odpadowego syntetycznego oleju silnikowego, a więc zasilania nim ogniw paliwowych.
Ogniwo paliwowe zasilane emulsją oleju rzepakowego
2017
W pracy przedstawiono badania nad możliwością wykorzystania oleju rzepakowego jako substancji czynnej do zasilania ogniwa paliwowego. W tym celu zbudowano testowe ogniwo paliwowe. Ogniwo zasilano emulsją oleju rzepakowego. Jako detergent zastosowano Syntanol DS-10. Wykorzystano anodę z katalizatorem platynowym oraz katodę z katalizatorem Ni-Co. Pomiary przeprowadzono w temperaturze 293–333K. Maksymalna uzyskana gęstość prądu wynosiła 2 mA/cm2, natomiast maksymalna moc ogniwa 21 mW (dla temp. 333K). Wykazano, więc możliwość bezpośredniego dostarczania oleju rzepakowego (w formie emulsji) na anodę. Uzyskana moc ogniwa była stosunkowo niska, jednak istnieje możliwość zbudowania ogniwa paliwowe…
Allocation of Ambipolar Charges on an Organic Diradical with a Vinylene-Phenylenediyne Bridge.
2021
Two redox and magnetically active perchlorotriphenylmethyl (• PTM) radical units have been connected as end-capping groups to a bis(phenylene)diyne chain through vinylene linkers. Negative and positive charged species have been generated, and the influence of the bridge on their stabilization is discussed. Partial reduction of the electron-withdrawing • PTM radicals results in a class-II mixed-valence system with the negative charge located on the terminal PTM units, proving the efficiency of the conjugated chain for the electron transport between the two terminal sites. Counterintuitively, the oxidation process does not occur along the electron-rich bridge but on the vinylene units. The • …
Sterigmatocystin-induced cytotoxicity via oxidative stress induction in human neuroblastoma cells.
2020
Abstract Sterigmatocystin (STE) is a mycotoxin produced by fungi of the genus Aspergillus. Considering that the effect of STE on neuronal system has not been well studied, the aim of the present study consists to investigate the cytotoxic effects of STE in human neuroblastoma (SH-SY5Y) cells. Moreover, the role of oxidative stress and intracellular defense systems was assessed by evaluating reactive oxygen species (ROS) generation, lipid peroxidation (LPO) and antioxidant no-enzymatic (GSH) levels and enzymatic (GPx, GST, CAT and SOD) activity. Our results revealed that STE decreased cell viability in a dose and time-dependent manner. Furthermore, after 24 h of exposure, STE induced an incr…
Effect of electron-beam irradiation on structure of ultra high molecular weight polyethylene used in medical implants
2004
Określono wpływ napromieniania strumieniem elektronów dawką równoważną stosowanej w praktyce podczas sterylizacji radiacyjnej endoprotez chirurgicznych (26 kGy) oraz dwukrotnie większą (2 . 26 kGy) na zmianę struktury PE-UHMW o nazwie handlowej „,Chirulen 1120”' (tabela 1) służącego do otrzymywania panewek endoprotez biodrowych. Metodą FT-IR zbadano zmiany strukturalne polimeru, stwierdzając głównie występowanie skutków jego utlenienia (wzrost udziału grup karbonylowych typu ketonowego, estrowego i nadestrowego, grup hydroksylowych oraz winylowych) (rys. 1). Metodą GPC stwierdzono, że napromienianie powoduje także częściową degradację makrocząsteczek (zmniejszenie ciężaru cząsteczkowego o j…
Molecular docking and oxidation kinetics of 3-phenyl coumarin derivatives by human CYP2A13
2021
CYP2A13 enzyme is expressed in human extrahepatic tissues, while CYP2A6 is a hepatic enzyme. Reactions catalysed by CYP2A13 activate tobacco-specific nitrosamines and some other toxic xenobiotics in lungs.To compare oxidation characteristics and substrate-enzyme active site interactions in CYP2A13 vs CYP2A6, we evaluated CYP2A13 mediated oxidation characteristics of 23 coumarin derivatives and modelled their interactions at the enzyme active site.CYP2A13 did not oxidise six coumarin derivatives to corresponding fluorescent 7-hydroxycoumarins. The Km-values of the other coumarins varied 0.85���97 ��M, Vmax-values of the oxidation reaction varied 0.25���60 min���1, and intrinsic clearance var…
Molybdenum(VI) complexes with a chiral L-alanine bisphenol [O,N,O,O’] ligand : Synthesis, structure, spectroscopic properties and catalytic activity
2023
Dioxidomolybdenum(VI) compound [MoO2Cl2(dmso)2] reacts with a chiral tetradentate O3N-type L-alanine bisphenol ligand precursor (Et3NH)H2Lala to form an oxidochloridomolybdenum(VI) complex [MoOCl(Lala)] (1) as two separable geometric isomers with phenolate groups in cis or trans positions. The single crystal X-ray and NMR analyses of cis- and trans-1 reveal that the complexes are formed of monomeric molecules, in which the ligand has a tetradentate coordination through three oxygen donors and one nitrogen donor. The reaction of Na2MoO4·2H2O with the same ligand precursor in an acidic methanol solution leads to the formation of an anionic dioxido complex (Et3NH)[MoO2(Lala)] (2) with a trans …
Non-linear interactions of femtosecond laser pulses with graphene : photo-oxidation, imaging and photodynamics
2017
This thesis presents a study focused on interactions of femtosecond laser pulses with graphene, a one atom thick carbon membrane. Graphene, which exhibits exceptional electronic and optoelectronic properties, could provide considerable advantage over current silicon-based electronics. Graphene alone, being semi-metal, is not sufficient for electronic applications, but requires modification. For this, a set of methods for modifying and measuring the properties of graphene was developed. With the perspective of making graphene a suitable component for electronics, optoelectronics or photonics, ultrashort laser pulses were used for drawing patterns on graphene. The procedure modifies graphene …
Involvement of Lipoxygenase-dependent Production of Fatty Acid Hydroperoxides in the Development of the Hypersensitive Cell Death induced by Cryptoge…
1999
Lipid peroxidation was investigated in relation with the hypersensitive reaction in cryptogein-elicited tobacco leaves. A massive production of free polyunsaturated fatty acid (PUFA) hydroperoxides dependent on a 9-lipoxygenase (LOX) activity was characterized during the development of leaf necrosis. The process occurred after a lag phase of 12 h, was accompanied by the concomitant increase of 9-LOX activity, and preceded by a transient accumulation of LOX transcripts. Free radical-mediated lipid peroxidation represented 10% of the process. Inhibition and activation of the LOX pathway was shown to inhibit or to activate cell death, and evidence was provided that fatty acid hydroperoxides ar…
Impact of a Pitanga Leaf Extract to Prevent Lipid Oxidation Processes during Shelf Life of Packaged Pork Burgers: An Untargeted Metabolomic Approach
2020
In this work, the comprehensive metabolomic changes in pork burgers treated with different antioxidants, namely, (a) a control without antioxidants, (b) 200 mg/kg butylated hydroxytoluene (BHT), and (c) 250 mg/kg pitanga leaf extract (PLE, from Eugenia uniflora L.), each one packaged under modified atmosphere (80% O2 and 20% CO2) for 18 days storage at 2 ±