Search results for "Oxide"

ODS steel raw material local structure analysis using X-ray absorption spectroscopy

2015

Oxide dispersion strengthened (ODS) steels are promising materials for fusion power reactors, concentrated solar power plants, jet engines, chemical reactors as well as for hydrogen production from thermolysis of water. In this study we used X-ray absorption spectroscopy at the Fe and Cr K-edges as a tool to get insight into the local structure of ferritic and austenitic ODS steels around Fe and Cr atoms and its transformation during mechanical alloying process. Using the analysis of X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) we found that for austenitic samples a transformation of ferritic steel to austenitic steel is detectable after …

Die autoxydation von linolsäuremethylesterhydroperoxyd. Über die autoxydation ungesättigter verbindungen. XIII. Mitteilung

1961

Linolsauremethylesterhydroperoxyd wurde mit Hilfe der O'KEEFFE-Verteilung aus autoxydiertem Linolsauremethylester isoliert. Die Autoxydation dieses Hydroperoxydes verlauft rascher als die des Linolsaureesters. Die Reaktion verlaft aber nicht autokatalytisch und ist nach Aufnahme von 1 Mol Sauerstoff pro Mol Hydroperoxyd praktisch beendet; die Hydroperoxydgruppen bleiben dabei zum grosten Teil erhalten, die konjugierten Doppelbindungen verschwinden. Die Aktivierungsenergie dieser Reaktion ist um 3 kcal/Mol kleiner als die der Autoxydation des Linolsauremethylesters. Es wird ein Mechanismus vorgeschlagen, bei dem das Linolsauremethylesterhydroperoxyd hauptsachlich in biomolekularer Startreakt…

Recent Advances in Electrochromics for Smart Windows Applications

1998

Electrochromic smart windows are able to vary their throughput of radiant energy by low-voltage electrical pulses. This function is caused by reversible shuttling of electrons and charge balancing ions between an electrochromic thin film and a transparent counter electrode. The ion transport takes place via a solid electrolyte. Charge transport is evoked by a voltage applied between transparent electrical conductors surrounding the electrochromic film/electrolyte/counter electrode stack. This review summarizes recent progress concerning (i) calculated optical properties of crystalline WO3, (ii) electrochromic properties of heavily disordered W oxide and oxyfluoride films produced by reactiv…

Electric current induced modification of germanium nanowire NEM switch contact.

2015

We present an investigation of contact properties of a germanium (Ge) nanowire based nanoelectromechanical (NEM) switch in its ON state. The contact stiffness in the ON state was evaluated by detecting the nanowire's resonance frequency. It was found that the resonance frequency increases when electric current flows through the nanowire/counter electrode contact area. The reason for modification in the contact area is referred to as electric-current-induced processes in the native oxide layer covering the nanowires. The presented resonance shift method is a simple way to indicate strengthening of the nanowire/counter electrode contact area without disassembling the contact.

Oscillatory Changes of the Heterogeneous Reactive Layer Detected with the Motional Resistance during the Galvanostatic Deposition of Copper in Sulfur…

2015

Metallic copper was galvanostatically deposited on quartz|gold resonant electrodes by applying a constant current in a 0.5 M CuSO4/0.1 M H2SO4 aqueous solution. Galvanostatic copper deposition is one of the best methodologies to calibrate the electrochemical quartz crystal microbalances (EQCM), a gravimetric sensor to evaluate changes in mass during the electrochemical reactions through the Sauerbrey equation. The simultaneous measurement of mass, current density, and motional resistance by an EQCM with motional resistance monitoring allows us to characterize the processes occurring on the electrode surface and at the interfacial regions with unprecedented detail. During the galvanostatic c…

A Ferromagnetic [Cu3(OH)2]4+Cluster Formed inside a Tritopic Nonaazapyridinophane: Crystal Structure and Solution Studies

2009

Some aspects of cardiac antioxidant defence: Ebselen (PZ 51) treatment increases glutathione peroxidase activity in the rat heart

1990

Ebselcn (PZ 5 1 : 2-phenyl1.2-benzisoelenazol-3-( 2H)-one 1 is ii synthetic organoselenium compound with anti-inflammatory activity ( I . 21, which exhibits glutathione peroxidase (GSH-Px)-like activity, catalysing the reduction o f hydrogen peroxide as well as other organic peroxides [3-5]. Its antiinflammatory effect may be mediated by either the GSH-Px activity, the inhibition of leukotriene B4 formation [6], the antioxidant capacity, or a combination of all of them. Many attempts have been made to increase the antioxidant capacity of the myocardium, since free radical generation has been demonstrated in ischaemia-reperfusion damage [7, 81; superoxide dismutase (SOD) and catalase have be…

Role of oxygen and nitrogen species in experimental uveitis: anti-inflammatory activity of the synthetic antioxidant ebselen.

2002

This study was aimed at examining the role of oxygen and nitrogen reactive species in a model of experimental uveitis upon intravitreal injection of bacterial endotoxin to albino New Zealand rabbits. The inflammatory response was evaluated in terms of: (i) the integrity of the blood aqueous barrier (protein and cell content in samples of aqueous humor), (ii) histopathological changes of the eyes, (iii) clinical evaluation (with a score index based on clinical symptoms), and (iv) the concentration of malondialdehyde (MDA), in aqueous humor, as a marker of oxidative stress. Betamethasone was used as reference treatment, superoxide dismutase as quencher of superoxide anion, L-N(G)-nitro-L-argi…

11,12-EET Stimulates the Association of BK Channel α and β1 Subunits in Mitochondria to Induce Pulmonary Vasoconstriction

2012

In the systemic circulation, 11,12-epoxyeicosatrienoic acid (11,12-EET) elicits nitric oxide (NO)- and prostacyclin-independent vascular relaxation, partially through the activation of large conductance Ca(2+)-activated potassium (BK) channels. However, in the lung 11,12-EET contributes to hypoxia-induced pulmonary vasoconstriction. Since pulmonary artery smooth muscle cells also express BK channels, we assessed the consequences of BKβ(1) subunit deletion on pulmonary responsiveness to 11,12-EET as well as to acute hypoxia. In buffer-perfused mouse lungs, hypoxia increased pulmonary artery pressure and this was significantly enhanced in the presence of NO synthase (NOS) and cyclooxygenase (…

Impedance investigation of BaCe0.85Y0.15O3-delta properties for hydrogen conductor in fuel cells

2012

International audience; The influence of the sintering conditions on the electrochemical properties of the proton conducting electrolyte BaCe0.85Y0.15O3-delta (BCY15) and Ni - based BCY15 cermet anode for application in high temperature proton conducting fuel cell are investigated by electrochemical impedance spectroscopy. The results show that at lower sintering temperatures due to the formation of parasitic Y2O3 phase an increase of both the electrolyte and electrode resistances is observed. This effect is strongly reduced by enhancement of the sintering temperature. The obtained BCY15 conductivity (sigma = 2.5x10(-2) S/cm at 700 degrees C) is comparable with that of the best proton condu…