Search results for "Oxidation."
showing 10 items of 1877 documents
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 ±
Assessment of the suitability of pitanga leaf extract as a natural antioxidant for enhancing canola oil stability: monitoring lipid oxidation paramet…
2019
Effect of oxidoreduction potential and of gas bubbling on rheological properties and microstructure of acid skim milk gels acidified with glucono-del…
2009
Milk oxidoreduction potential was modified using gases during the production of a model dairy product and its effect on gel setting was studied. Acidification by glucono-delta-lactone was used to examine the physicochemistry of gelation and to avoid variations due to microorganisms sensitive to oxidoreduction potential. Four conditions of oxidoreduction potential were applied to milk: milk was gassed with air, nongassed, gassed with N(2), or gassed with N(2)H(2). The rheological properties and microstructure of these gels were determined using viscoelasticimetry, measurement of whey separation, and confocal laser scanning microscopy. It appeared that a reducing environment led to less-aggre…
Combined use of modified atmosphere packaging and high pressure to extend the shelf-life of raw poultry sausage
2014
International audience; The contribution of modified atmosphere packaging (MAP) in extending the shelf-life of high-pressure treated raw poultry sausages was examined by considering microbial and oxidative stability (TBARs) aspects. Raw poultry sausages packaged under air or modified atmosphere (50% CO2–50% N2) were pressurized at 500 MPa during 5 min at a maximum temperature of 10.5 °C, subsequently allowed to refrigerated storage during 22 days. During storage, samples were tested at time intervals for headspace gas composition, pH, TBARs, Aerobic Mesophilic Counts (AMC) and Lactic Acid Bacteria (LAB) counts. The high pressure treatment could represent an efficient means of extending the …
Methanol electrooxidation with Cu-B catalyst
2016
In the last few years alternative energy sources have been fast developing. One of these sources is fuel cell. Due to development of the renewable energy sources, the powering of fuel cells with bio-fuels is very important. The one of this fuel is methanol. The use of fuel cells on a large scale is mainly limited by the high cost of catalysts - mainly platinum. Elimination of Pt as catalyst would allow for wider commercial application of fuel cells. The paper presents a study of methanol electrooxidation on electrode with Cu-B alloy catalyst. Researches were done by the method of polarizing curves of electrooxidation of methanol in glass vessel. An aqueous solution of KOH was used as the el…
Canola oil electrooxidation in an aqueous solution of KOH - Possibility of alkaline fuel cell powering with canola oil
2016
In the last few years alternative energy sources have been fast developing. One of these sources is fuel cell. Due to development of the renewable energy sources, the powering of fuel cells with bio-fuels is very important. Vegetable oil is an alternative fuel for Diesel engines and for heating oil burners. Powering high efficiency power sources like fuel cells with renewable fuels (like vegetable oil) will allow development of renewable energy sources and elimination or reduce of toxic substances emissions. The paper presents the possibility of using canola oil as fuel for fuel cells. The work shows possible electrooxidation of canola oil emulsion prepared on the basis of a nonionic surfac…
Electricity production from waste engine oil from agricultural machinery
2017
As fuel for fuel cells can be used various substances, but generally fuel cells are powered by hydrogen. However, problems with the storage of hydrogen are the reason for the search of new fuels for fuel cells. Moreover, annually are produced huge amount of waste oils. These oils must be directed to purification and processing. It would be important to use waste engine oil as fuel for fuel cell to direct electricity production without intermediate stage e.g. combustion. The paper presents the possibility of using waste engine oil as fuel for fuel cell. The oil does not have the feature of electrical conductivity, for this reason a detergent was used for dissolving oil in an electrolyte. So,…