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The dissolved oxygen concentration must be well controlled in liquid Pb for use as a primary coolant of fast spectrum nuclear reactors. We have measured fundamental data of oxygen in liquid Pb. The Sieverts constant and solubility of oxygen were measured by coulometric titration. Thermal cycling of liquid Pb allowed a quantification of the excess oxygen above solubility required to initiate solid PbO nucleation, which is the metastable limit in liquid Pb. The data obtained in this study are as follows

de L. Corrêa, H, Ribeiro, HS, Maya, ÁTD, Neves, RP, de Moraes, MR, Lima, RM, Nóbrega, OT, and Ferreira, AP. Influence of the ACTN3 genotype and the exercise intensity on the respiratory exchange ratio and excess oxygen consumption after exercise. J Strength Cond Res 35(5): 1380-1388, 2021-This study aimed to assess the respiratory exchange ratio (RER) and excess postexercise oxygen consumption (EPOC) after high-intensity interval training and continuous moderate-intensity aerobic training in accordance with the ACTN3 genotype. A cross-sectional study with 30 physically active individuals who participated in 3 experimental sessions, as follows: a high-intensity interval aerobic exercise, for 3 minutes at 115% anaerobic threshold, with 90 seconds of passive recovery; a continuous moderate-intensity aerobic exercise at 85% anaerobic threshold; and a control session. Respiratory exchange ratio and V̇o2 were obtained through an indirect, calorimetry-based gas analysis method, using a breath-by-breath approach, assessed at baseline, during the trials, and at 1, 2, 3, and 4 hours after exercise. We found that lower postexercise RER values were observed only in subjects with the X allele, in both the high- and the moderate-intensity training protocols. Homozygous RR subjects showed no differences in postexercise RER compared with the scores at the control day. After both sessions of exercise, EPOC levels were higher compared with scores at the control day for 2 hours among X allele carriers, and only in the first hour among RR homozygous. Thus, the RER and EPOC presented different responses after moderate and intense exercise according to the ACTN3 genotype. Moreover, individuals with the X allele of the ACTN3 gene show a higher oxidation of fats in the postexercise period.

We have presented the evidence of hole self-doping due to excess oxygen addition in polycrystal LaMnO3(LMO). The polycrystal LMO samples were prepared by use of a solid-state reaction method. Powder mixtures with a molar ratio of 1:1 between La2O3and Mn2O3were pre-annealed at 1100oC for 18 hours in the atmospheres of oxygen gas, helium gas and vacuum. By this heat treatment, non-crystalline LMO samples were produced. After that, the non-crystalline LMO samples were grinded and were pressed into pellets at the pressure of 3t/cm3. The pellets were annealed at 1100oC and 1300oC for 18 hours in the same atmospheres as the pre-annealing. Through these processes, polycrystal LMO samples were finally produced. To investigate crystallographic structure of the LMO samples, X-ray diffraction (XRD) measurements were performed by use of Cu-K radiation. From the experimental results of XRD measurements, we have found that all LMO samples have perovskite structure and are polycrystals. In addition, to investigate surface structure of the LMO samples, scanning electron microscope (SEM) measurements were carried out. Electrical resistivities (ERs) of the polycrystal LMO samples were measured as a function of temperature (4K-300K). The ERs of polycrystal LMO samples produced in an oxygen gas atmosphere show lower values as compared with other LMO ones in He gas and vacuum atmospheres. Especially, the temperature dependence of the ER for a polycrystal LMO sample produced at the annealing temperature of 1100oC in an oxygen atmosphere shows a metallic behavior. Thus, we have considered that this LMO sample has the largest hole self-doping concentration in all LMO ones.

The Bancroft terrane and the associated Central Metasedimentary Belt boundary thrust zone represent the northern part of the Central Metasedimentary Belt (CMB) of the Canadian Grenville Province. Only a few direct pressure and temperature calculations based on phase equilibrium petrology methods exist in the central Bancroft terrane, and this study applies thermodynamic approaches such as garnet isopleth geothermobarometry to fill this gap and investigate the metamorphic history of the northern CMB. Four metapelitic rock samples were collected in the vicinity of the enigmatic Bancroft shear zone, which approximates the border between the Bancroft terrane and the Elzevir terrane to the south. Garnet isopleths for these samples only intersect if a certain amount of excess oxygen is added to the bulk rock composition corresponding to a Fe3+/Fetot ratio of 0.33–0.38. The northernmost sample records metamorphic peak conditions of approximately 1 GPa and 780 °C, whereas the southernmost sample, which is located in the Elzevir terrane, records a peak metamorphic pressure of approximately 0.9 GPa at a temperature of 520 °C. The latter result contradicts previous pressure estimates of the region and the proposed metamorphic field gradient but is based on a poorly constrained sample in terms of thermodynamic modeling. Hence, we conclude that the metamorphic field gradient in the northern CMB conceals two different P–T trajectories. Such a scenario is commonly observed in crustal thickening models and suggests that the cold upper plate (Elzevir terrane) was thrust over the warm lower plate (Bancroft terrane) in a northwesterly direction.

The level of oxygen saturation in the blood is important to know the health condition of the body. If the human body lacks or excess oxygen, it will cause illness and other bodily system work disorders. One of the tools to detect the oxygen saturation level is the Pulse oximeter. Previous research has successfully designed a Pulse oximeter based on Arduino. The pulse oximeter produces a photoplethysmograph (PPG) signal that corresponds to the standard PPG signals in 20 test samples. PPG signals can be processed to provide information on oxygen saturation (SpO2) levels in the blood. In this research, validation of the Pulse oximeter is compared with a commercial pulse oximeter, the digital oximeter JZK-301. The results obtained from this validation are the smallest deviation errors are 4.83% while the largest errata is 22.51%. The greatest accuracy of 95.17%, of respondents number 16 and the smallest accuracy is 77, 49%, that is the number of respondents 12. The average deviation of 20 data is 12.82% with the resulting accuracy is 87, 18%. This indicates that the self-designed pulse oximeter has good efficiency and can be developed further

This study investigated the homogeneous formation and reduction of NO from the oxidation of CH4/NH3 to understand the effect of the high concentrations of H2O on NO emissions. The experimental results about the effects of excess oxygen ratio, gas compositions including H2O, CO2, NH3 and recycled NO, on NO formation and reduction were presented. The mechanism about the effects of high concentration of H2O and combined effect of H2O/CO2 on NO formation and reduction has been discussed. The results indicates that NO formation was markedly enhanced at high concentrations of H2O, which were mainly attributed to the increased OH radicals with steam addition at oxygen-rich conditions. By contrast, the radicals were consumed by reduction radicals, such as CO, H, and CHi radicals, under oxygen-lean conditions. NO concentrations followed the sequence of H2O/Ar > H2O/CO2 > CO2/Ar under both the oxygen-rich and oxygen-lean conditions, which meant that the highest and lowest NO emissions were recorded in Ar/H2O and CO2/Ar respectively. The combined H2O/CO2 concentration accordingly exerted an effective impact on NO reduction. The results about the effect of NH3 concentration in fuel on NO emission showed that NO emission increased with increasing NH3 concentration. Furthermore, NO reburning results implied that with increasing NO concentration, the total NO reduction increased, whereas the reduction ratio decreased.

A process has been developed to oxidise methane at low temperatures in an excess oxygen environment using ozone as the oxidant. Ozone being more reactive than oxygen allows low temperature methane control. A range of catalysts have been screened and a commercially available current production Fe-BEA catalyst, from an automotive application has shown excellent potential for methane control with ozone in the feed, leading to a peak conversion efficiency of 81% at 168 °C in the absence of H2O and 60% conversion at 220 °C in the presence of H2O.

Premature infants undergo a complex postnatal adaptation at birth. For last two centuries, oxygen has been integral to respiratory support of preterm infants at birth. Excess oxygen can cause oxidative stress and tissue injury. Preterm infants due to lung immaturity may need oxygen for successful transition at birth. Although, considerable progress has been made in the last 3 decades, optimum oxygen therapy for preterm delivery room resuscitation remains unknown. In this review, we discuss the history and physiology behind oxygen therapy in the delivery room, evaluate current literature, provide practice points and point out knowledge gaps of oxygen therapy in preterm infant at birth.

Recently, superconductivity was induced by expanding interlayer distance between Bi square nets in anti-ThCr2Si2-type Y2O2Bi through incorporation of excess oxygen with increased nominal amount of ...

In this study, a novel composite Ni-OTiO2 was prepared by doping nickel and introducing excess oxygen defects in TiO2. The as-synthesized Ni-OTiO2 particles were characterized by scanning electron ...

An important issue of solid-waste energy recovery is related to the methods that prevent both the synthesis and emission of dioxins and furans. Carbon-sorbent injection into a gas flow of the incinerators and industrial furnaces is a leading and proven technology [1, 2]. Both the high temperatures of the gas flow and excess oxygen complicate the usage of active carbons, since an exceedance of 300°C gives rise to the initiation of sorbent combustion [3]. A carbon material was prepared using thermomechanical activation of fine-dispersed coke dust and proposed for solving this problem [4].

The low-temperature NO decomposition with high efficiency remains a grand challenge. Herein, we report an attractive approach for the low-temperature NO decomposition by microwave catalysis over BaMnO 3 and substituted Ba 0.8 A 0.2 MnO 3 (A Ca, K, La) catalysts. Importantly, impressively high NO conversion and N 2 selectivity with 99.9% and 99.9%, respectively, were achieved over Ba 0.8 K 0.2 MnO 3 catalyst at 250 °C. Comparatively, under identical conditions in the conventional reaction mode, the highest NO conversion and N 2 yield are respectively only 45.4% and 28.7% for Ba 0.8 K 0.2 MnO 3 at 650 °C. Unexpectedly, the effect of Ca, K and La substitution is different in these two reaction modes. The catalysts were characterized by H 2 -TPR, O 2 -TPD, and microwave absorbing properties to illustrate possible reasons causing such obvious differences in catalytic performance. The apparent activation energies for BaMnO 3 , Ba 0.8 Ca 0.2 MnO 3 , Ba 0.8 K 0.2 MnO 3 and Ba 0.8 La 0.2 MnO 3 catalysts under microwave irradiation drop down to as low as 33.4, 41.6, 14.7 and 18.2 kJ/mol, separately, suggesting a significant microwave catalytic effect.

It is established that excess oxygen content δ influences the exchange bias (EB) in layered GdBa-Co2O5 + δ cobaltite. The EB effect arises in p-type (δ > 0.5) cobaltite and disappears in n-type (δ < 0.5) cobaltite. The main parameters of EB in GdBaCo2O5.52(2) polycrystals are determined, including the field and temperature dependences of EB field H EB , blocking temperature T B , exchange coupling energy J i of antiferromagnet–ferromagnet (AFM–FM) interface, and dimensions of FM clusters. The training effect inherent in systems with EB has been studied. The results are explained in terms of exchange interaction between the FM and AFM phases. It is assumed that the EB originates from the coexistence of Co3+ and Co4+ ions that leads to the formation of monodomain FM clusters in the AFM matrix of cobaltite.

This paper investigates the authenticity of the biofuels as an alternative to Jet A fuel. Owing to the fact of reduced CO2 emission quality, biofuels can be used in the field of aviation to substantially reduce the CO2 emission and improve the performance. In this analysis, microalgae Spirulina biofuel was added with Jet-A fuel at different proportions such as 20%, 40%, 60%, 80% and 100%. The proportions used are B20% (20% biofuel with 80% jet-A fuel), B40% (40% biofuel with 60% Jet-A fuel), B60% (60% biofuel with 40% Jet-A fuel), B80% (80% biofuel with 20% Jet-A fuel) and B100% biofuel. All the test results were compared with the neat jet A fuel. The experiments were conducted at different engine speeds. A small experimental jet engine was used to conduct all the experimental tests. Engine performance characteristics and emission characteristics were found for different fuel blends. It is concluded that the biofuel at a lower proportion level with the Jet–A fuel comparatively produced a good result. In terms of thrust and engine speed, the lower level of addition of biofuel is fruitful. The emission level of CO, CO2, and NOx was reduced owing to the presence of excess oxygen content in the blends. However, when the addition percentage was increased, the results produced by them were not positive because of its low energy.

We have studied transport properties of several NdBa 2 Cu 3 O 7-δ superconductors using wide range of excess oxygen content δ. The buckling angle is found to be very sensitive with δ. Disordered copper oxide planes are origins of the superconducting properties controlling of which is possible by changing the buckling angle in superconducting planes in addition to the carrier concentration. A phase diagram consisting of the characteristic temperature T* related to the formation of pseudogap and critical temperature with δ has been obtained. The effect of the changed buckling angle on the pseudogap formation with δ has been also studied.

A mild cascade approach for the generation of 2-(α-hydroxyacyl)pyrroles under Ag(I) catalysis has been reported. This strategy involves a 5-exo-dig cyclization of insitu generated imines from 6-hydroxyhex-2-en-4-ynals and primary amines followed by oxidation. The reaction is very general for propargylic alcohols, tethers and primary amines. Efficient synthesis of core structures of pyrrole based bioactive natural products have also been achieved. Control experiments revealed the fact that, presence of excess oxygen and water may favor the competitive formation of the furans over the pyrroles.

Operating data of a bubbling fluidized bed (BFB) boiler and three stoker grate (SG) biomass boilers from different pulp mills were analyzed over a 2-year period. The results show that in all cases, the thermal perfor - mance decreases markedly from 5.5 to 4 lb steam/lb dry biomass as the feedstock moisture content increases from 40% to 60%. The BFB boiler had better thermal performance, although it operated in a higher moisture content range compared with the SG boilers. Multivariate analysis was also performed on one of the SG boilers to determine operating parameters that affect thermal performance. The results show that furnace temperature, oil flow rate, and induced draft fan current positively correlate with thermal performance, while the feedstock moisture content, total air flow, and excess oxygen (O 2 ) negatively correlate with thermal performance. This implies that when making mod - ifications to improve thermal performance, it is important to take into account correlations among various parame - ters. In some cases, one positively correlated parameter might cause an increase in a negatively correlated parame - ter. The net effect might be a decrease in thermal performance.

The crystallization process of CaO in iron melt begins with nucleation, which determines the structure and size of the CaO inclusions; thus, it is important to investigate the mechanism of inclusion modification by calcium treatment. In this study, a two-step nucleation method was used to investigate the behavior during the early stages of CaO inclusion crystallization. The first principles method was applied to calculate the structures and properties of CaO crystals and CaO clusters. Then, the nucleation mechanism of CaO in the Fe-O-Ca melt has been discussed. The numerical results show that CaO clusters with cubic structures and appropriate variations are the lowest energy structures and are more stable than other isomers. The stability of the cubic (CaO)n clusters increases with the increase in size and gradually approaches that of the CaO crystal. CaO clusters can form spontaneously in the Fe-O-Ca melt, while the transformation reaction of the CaO clusters in the Fe-O-Ca melt deeply depends on the supersaturation ratio of [Ca] and [O]. CaO clusters may remain as suspended CaO inclusions in the iron melt for a long time, and these suspensions of CaO clusters are the source of excess oxygen in the iron melt.

The effect of Al doping concentration on resistive switching characteristics of Pt/Al-doped HfO x /Cu structures was investigated. According to the X-ray photoelectron spectroscopy (XPS) analysis and the first-principle calculation, the Al doping introduced more oxygen vacancies in HfO x film and these oxygen vacancies can be easily generated along Al dopants. Significant enhancement in resistive switching behaviors was achieved for 6.8% Al-doped HfO x film in terms of ON/OFF ratio, switching voltages and uniformity, whereas the higher Al doping concentration of 9.4% caused excess oxygen vacancies in the film, resulting in the degeneration of switching performance. A schematic diagram based on the formation and rupture of oxygen vacancy filaments was proposed to illustrate the distinct switching behaviors of HfO x and Al-doped HfO x samples. The results indicated that the concentration and distribution of oxygen vacancies played an important role on resistive switching behavior. The reliability properties for the prepared HfO x samples were also investigated. This work might provide a guidance for the further optimization of HfO x -based memory.

Oxy-fuel circulating fluidized bed (CFB) combustion combining the advantages of oxy-fuel combustion and CFB technology is one of the most promising technologies for capturing CO2. However, the emission of N2O in oxy-fuel CFB combustion can be high enough to raise some related environmental issues. This study investigated N2O emission in O2/CO2 CFB combustion with a high oxygen concentration based on the experimental results using a the 0.1 MWth oxy-fuel CFB. This study focused on the operating parameters. It was found that increasing the combustion temperature and overall oxygen concentration can lead to lower N2O emission, while increasing the excess oxygen ratio can lead to higher N2O emission levels. Both gas staging and oxygen staging have slight adverse influences on controlling N2O owing to the higher oxygen concentration in the secondary gas. Finally, the excess oxygen ratio in the primary zone was determined in order to assess the actual effects of gas and oxygen staging on both N2O and NO emissions.

The impact of H 2 as additional reducing agent on the SCR of NO with C 3 H 6 in excess oxygen, was comparatively explored over low noble metal loading (0.5 wt%), Pt/γ-Al 2 O 3 , Pd/γ-Al 2 O 3 , Ir/γ-Al 2 O 3 catalysts. To gain insight into the role of H 2 , the reactions NO + C 3 H 6 + O 2 (R#1), NO + C 3 H 6 + O 2 + H 2 (R#2), NO + H 2 + O 2 (R#3) were employed. In respect to propene oxidation, the Pd > Pt > Ir sequence was obtained under R#1, since they exhibit complete conversion at 220, 250, 325 °C, respectively; all metals exhibit moderate deNO x performances ( X NO, 2 co-presence (R#2) promotes both the NO and C 3 H 6 conversions, which is valid in the whole temperature interval investigated (50–400 °C), being more substantial for Pt/γ-Al 2 O 3 and Ir/γ-Al 2 O 3 , less beneficial for Pd/γ-Al 2 O 3 . A two-maxima feature is obtained on X NO pattern (at ∼100 and ∼230 °C) of Pt and Pd during R#2. The low temperature maximum −attributed to NO reduction by H 2 - is substantially more pronounced on Pt than Pd, offering X NO ∼90% and S N2 ∼85%; the high temperature maximum—attributed to NO reduction by C 3 H 6 —is higher by ∼15% on both Pt and Pd, in respect to the values obtained during R#1, while S N2 remained unaffected. Different X NO pattern with one maximum is obtained over Ir, implying a synergistic interaction between H 2 and C 3 H 6 . This synergy is accompanied by a substantial widening of the NO reduction window toward lower temperatures and a considerable increase on both X NO,max and S N2 (from X NO ∼30% with S N2 ∼55% during R#1 to X NO ∼70% with S N2 ∼95% during R#2). The specific features of all reactions and metals employed are comparatively discussed.

Mixed ionic and electronic conducting K2NiF4-type oxide, Nd2Ni1-xCuxO4+δ (x=0~1) powders were synthesized by solid state reaction technique and solid oxide fuel cells consisting of a Nd2Ni1-xCuxO4+δ cathode, a Ni-YSZ anode and ScSZ as an electrolyte were fabricated. The effect of copper substitution for nickel on the electrical and electrochemical properties was examined. Small amount of copper doping (x=0.2) resulted in the increased electrical conductivity and decreased polarization resistance. It appears that this phenomenon was associated with the high mean valence of nickel and copper and the resulting excess oxygen (δ). It was found that power densities of the cell with the Nd2Ni1-xCuxO4+δ (x=0.1 and 0.2) cathode were higher than that of the cell with the Nd2NiO4+δ cathode.

The effects of the temperature, oxygen concentration, and excess oxygen coefficient on mercury oxidation under O2/CO2 and O2/N2 coal combustion were experimentally analyzed in a fluidized bed. The results suggested that both the concentration and proportion of Hg0 increased as the temperature increased under oxy-coal combustion. Mercury was also primarily in elemental form at high temperatures under oxy-coal combustion. Mercury oxidation was much less effective in the presence of CO2. The percentages of Hg0 and Hg2+ increased as the excess oxygen coefficient increased under oxy-coal combustion.

Type III silica samples were implanted with O using a multi-energy process that produced a layer of constant concentration to within ±5% beginning ∼80 nm from the surface and extending to ∼640 nm below the surfaces of the samples. The concentrations of excess oxygen in the layer ranged from 0.035 to ∼2.1at.%. In these samples we show that E′ centers and NBOHCs, as well as the normal cadre of ODC (II) centers, were suppressed, and the optical absorption from 4.7 to 6.4 eV was primarily due to oxygen excess defects. Using Gaussian fitting techniques to examine the optical difference spectra, we have been able to identify four defect centers that are related to excess oxygen defect bands at 4.76 eV, 5.42 eV, 5.75 eV and 6.25 eV.

The cathodes of MFCs are the main bottleneck for practical application; undesired cathode biofilms often cause their breakdown. The goal of this study was to extend cathode life time. Membranes were applied on the air side of the cathodes to limit oxygen penetration and reduce biofilm formation. Two single chamber MFC designs with an electrode spacing of 120 mm (HRT ∼1 week) and 15 mm (HRT 24 h) were investigated in batch operation using a synthetic blackwater at room temperature (23 ±3 °C). At high electrode spacing cathode life time was increased to 217%, with a significantly increase in power densities over time. The Power densities at 15 mm electrode spacing reached 1155 ± 41 mW m−2 with the membrane applied; compared to 460 ± 32 m Wm−2 without membrane. TOC degradation relative to the anode surface at close electrode spacing was near equal at 6.8 ± 2.3 and 7.2 ± 3.0 gm−2 d−1; however, the Coulomb Efficiency with a membrane increased from 28 ± 10% to 54 ± 13%. CV analysis after operation showed considerably higher ORR activity of the cathodes covered by a membrane.

Standard genetic algorithms (SGAs) are investigated to optimise discrete-time proportional-integral-derivative (PID) controller parameters, by three tuning approaches, for a multivariable glass furnace process with loop interaction. Initially, standard genetic algorithms (SGAs) are used to identify control oriented models of the plant which are subsequently used for controller optimisation. An individual tuning approach without loop interaction is considered first to categorise the genetic operators, cost functions and improve searching boundaries to attain the desired performance criteria. The second tuning approach considers controller parameters optimisation with loop interaction and individual cost functions. While, the third tuning approach utilises a modified cost function which includes the total effect of both controlled variables, glass temperature and excess oxygen. This modified cost function is shown to exhibit improved control robustness and disturbance rejection under loop interaction. © 2015 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg

The catalytic performance of a series of La-Fe/AC catalysts was studied for the selective catalytic reduction (SCR) of NO by CO. With the increase in La content, the Fe2+/Fe3+ ratio and amount of surface oxygen vacancies (SOV) in the catalysts increased, thus the catalytic activity improved. Incorporating the promoters to La3-Fe1/active carbon (AC) catalyst could affect the catalyst activity by changing the electronic structure. The increase in Fe2+/Fe3+ ratio after the promoter addition is possibly due to the extra synergistic interaction of M (Mn and Ce) and Fe through the redox equilibrium of M3+ + Fe3+ &harr, M4+ + Fe2+. This phenomenon could have improved the redox cycle, enhanced the SOV formation, facilitated NO decomposition, and accelerated the CO-SCR process. The presence of O2 enhanced the formation of the C(O) complex and improved the activation of the metal site. Mn@La3-Fe1/AC catalyst revealed an excellent NO conversion of 93.8% at 400 &deg, C in the presence of 10% oxygen. The high catalytic performance of MnOx and double exchange behavior of Mn3+ and Mn4+ can increase the number of SOV and improve the catalytic redox properties.

As one of the most promising carbon capture technologies for coal-fired power plants, oxy-coal combustion has attracted wide interests during the last two decades. In comparison to atmospheric oxy-fuel combustion, pressurized oxy-fuel combustion has the potential to further reduce the energy penalties caused by the carbon capture and storage and improve the net power plant efficiency. Although many researchers have investigated the NOx emissions of atmospheric oxy-coal combustion, the NOx emission behaviors under pressurized oxy-coal combustion conditions are much less understood and further comprehensive experimental investigations with continuous fuel-feeding pressurized oxy-coal combustion systems are needed in order to fill this knowledge gap. In the present study, a series of oxy-coal combustion experiments were conducted in a 30 kWth pressurized fluidized bed combustor. The effects of combustion pressure, bed temperature and excess oxygen on the NOx emissions were investigated systematically. The experimental results have shown that an increase in combustion pressure from 0.1 MPa to 0.4 MPa leads to a significant reduction in NOx emissions. An increase in bed temperature or excess oxygen results in higher NOx emissions under the higher combustion pressure conditions, which is consistent with what is observed under the atmospheric pressure combustion condition. Besides, it is found that the promoting effect of temperature increase on NOx emissions under the higher combustion pressures is weaker than that under the atmospheric pressure.

Amorphous indium gallium zinc oxide ($a$-IGZO) has drawn considerable interest as a channel material in flexible thin-film transistors (TFTs), to replace amorphous-Si-based TFTs, but $a$-IGZO-based TFTs show environment-dependent instability in threshold voltage. Investigating the variation of defect structures and subgap states with post-annealing temperature, this study reveals that the excess oxygen atoms surrounding cations or cation-vacancy-related defect clusters give rise to the instability. These results open a route to understanding the physical origin of device instability, and offer a feasible approach to tailoring such defects for practical applications.

In this paper, a series of Wx/Ag/Al2O3 catalysts with different tungsten contents (0, 0.04, 0.06, 0.08, and 0.10 g/g) and 0.03 g/g silver for selective catalytic reduction of NO with methanol under excess oxygen (methanol-SCR), were prepared with a traditional impregnation method. At a gas hourly space velocity (GHSV) of 30 000 h−1, the operating window of NO conversion (NO conversion above 50 %) shifted to a higher temperature region as the tungsten content increased. Importantly, the operating window of NO conversion over combined catalysts containing W8/Ag/Al2O3 in the front and Ag/Al2O3 in the rear (W8/Ag/Al2O3 + Ag/Al2O3), was wider (65 °C) than that of the single W8/Ag/Al2O3 catalyst (50 °C) or Ag/Al2O3 catalyst (41 °C). Further, the CO concentration over the combined catalyst was lower than the single W8/Ag/Al2O3 catalyst. The characterization results demonstrated that there are strong interactions between tungsten and silver which contribute to the formation and stabilization of oxidized silver species.

A series of hexagonal RMnO{sub 3} (R=Y, Ho–Lu) compounds are first annealed in various highly oxidizing conditions to show that for the largest R constituents, Y and Ho, it is possible to load the phases with large amounts of excess oxygen. Within the oxygen-annealed samples we identify new heavily-oxygenated phases, that is, YMnO{sub 3.35} and HoMnO{sub 3.34}. The former is then thoroughly characterized by thermogravimetric analysis, X-ray diffraction and electron diffraction. These studies evidence a hexagonal sub-cell (a{sub S}≈3.578 A (a{sub H}/√(3)), c{sub S}≈11.18 A, space group P6{sub 3}mc) and satellites, associated with two modulation vectors q{sup →}{sub 1}{sup ⁎}≈0.41a{sup →}{sub S}{sup ⁎}+0.41b{sup →}{sub S}{sup ⁎}+1/3c{sup →}{sub S}{sup ⁎}andq{sup →}{sub 2}{sup ⁎}=(1/2). The results are interpreted by the formation of a modulated composite structure, resulting from the evolution of the hexagonal parent YMnO{sub 3+δ} structure toward a reduced pyrochlore-type structure Y{sub 2}Mn{sub 2}O{sub 7−x}, in long- and short-range ordering. - Graphical abstract: Hexagonal RMnO{sub 3+δ} phases are commonly taken as oxygen-stoichiometric. Here we show that the R=Y and Ho phases can be loaded with excess oxygen up to δ≈0.35 through high-pressure oxygenation annealing. Formation of a new composite structure composed of hexagonal-like RMnO{sub 3+δ} and pyrochlore-like RMnO{sub 3.5−δ} constituents ismore » demonstrated in the case of R=Y. - Highlights: • Hexagonal RMnO{sub 3+δ} phases are commonly taken as oxygen-stoichiometric. • For R=Y and Ho phases excess-oxygen loading is possible. • Single-phase samples with a new composite structure are obtained at δ≈0.35. • The new structure is composed of hexagonal- and pyrochlore-like units.« less

A range of aryl sulfinates can be oxidatively dimerized to generate substituted biphenyls with concomitant extrusion of sulfur dioxide with a palladium catalyst. Catalytic amounts of TEMPO and excess oxygen are utilized as oxidants to regenerate the palladium catalyst.

We have succeeded in synthesizing hole-doped bulk superconductors of La 1.8-x Eu 0.2 Ca x CuO 4 ( x = 0.05 and 0.10) with the Nd 2 CuO 4 -type structure by means of the structural transformation at low temperatures from the K2NiF4-type structure via the Nd 4 Cu 2 O 7 -type structure. Superconductivity has appeared through the removal of excess oxygen by the reduction annealing in vacuum. Values of the superconducting transition temperature, T c , are 13 and 6 K for x = 0.05 and 0.10, respectively. These values are smaller than those of T’-La 1.8-x Eu 0.2 Sr x CuO 4 .

Along with SO2, NOx emissions are considered the main pollutants from solid-fired combustion systems. In fluidized-bed boilers, injection of limestone pursues SO2 retention, achieving capture efficiencies over 90%. Nevertheless, CaO formed from limestone calcination has been identified as a catalyst of N-compound reactions, increasing NO emissions. This paper investigates the effect of limestone addition on NO emissions under oxy-fired conditions, as well as the influences of bed temperature, O2 concentration in the fluidizing gas, and excess oxygen. To this purpose, a set of experiments were conducted in a 90 kWth bubbling fluidized-bed reactor, testing two different limestones for a variety of operating conditions and using anthracite as the fuel. The limestone with the lower SO2 capture capacity has shown the higher impact on NO emissions for all of the O2/CO2 atmospheres tested. It has also been observed that the higher the bed temperature and O2 excess, the higher the NO emissions. If compared to con...

The reaction behavior of CuAlO2during the annealing at high temperatures was investigated. The relationship between thermoelectric properties including electrical resistivity, excess oxygen doping and decomposition of CuAlO2was discussed. The evolution of CuAlO2compact during the annealing mainly included excess oxygen doping, decomposition of CuAlO2into CuAl2O4and CuO and complete decomposition of CuAlO2as following pattern : CuAlO2→ CuAlO2+x→ CuAlO2+CuO+ CuAl2O4→ CuAl2O4+CuO. Electrical resistivity of the compacts was decreased with excess oxygen doping, but increased when CuO and CuAl2O4were formed. Thermoelectric performance of the compacts was improved due to the excess oxygen doping.

The oxygen storage capability was investigated for Ca2(AlxMn1–x)2O5+δ (0.50 ≤ x ≤ 0.67) with a Brownmillerite-type structure. This oxide can store/release a large amount of excess oxygen (∼3.0 wt %) topotactically in response to variations in temperature and the surrounding atmosphere in a highly reversible manner. The capacity and response of oxygen storage are remarkable only in the vicinity of x = 0.50, that is, Ca2AlMnO5+δ, and rapidly deteriorated as the Al content increases. Owing to the high sensitivity in terms of oxygen nonstoichiometry, Ca2AlMnO5+δ exhibits oxygen intake/release ability when temperature swing between 500 and 700 °C is applied. With this characteristic feature of this oxide, a facile method for oxygen enrichment is demonstrated.

The langasite-type Ca3NbGa3Si2O14 [CNGS] piezoelectric crystals grown in Air and Ar were annealed under various temperatures and atmospheres and the effects of annealing on various properties were investigated. The absorption peaks around 360 and 500 nm of CNGS crystals grown in Air decreased by the annealing at 1300°C in Ar. On the other hand, the annealing at 1300°C in Air decreased transmittance in the range from 300 to 500 nm for the CNGS crystal grown in Ar. The results suggest that the absorptions around 350 and 500 nm originate from the excess oxygen and the post-annealing can control the oxygen content in the crystals.

Oxygen use in prehospital care is aimed at treating or preventing hypoxemia. However, excess oxygen delivery has important consequences in select patients, and hyperoxia can adversely impact outcome. The unique environment of prehospital care poses logistical and educational challenges. Oxygen therapy in prehospital care should be provided to patients with hypoxemia and titrated to achieve normoxemia. Changes to the current practice of oxygen delivery in prehospital care are needed.

The influence of coal blending methods, such as out-furnace (external or premixed) blending and in-furnace (initially nonmixed) blending, with different excess oxygen (highest, medium, and lowest s...

The oxidation behavior of a number of Fe–Cr- and Ni–Cr-based alloys was studied in atmospheres relevant to oxyfuel combustion at 650 °C. Oxidation was greatly enhanced in ferritic model alloys exposed in low p(O2) CO2 + 30%H2O and Ar + 30%H2O gases. Rapidly growing iron oxides appear to be porous and gas permeable. Transition from non-protective to protective oxidation occurs on alloys with higher Cr contents between 13.5 and 22 wt% in H2O. Excess oxygen, usually found in the actual oxyfuel combustion environments, disrupts the selective oxidation of Fe–Cr alloys by accelerating vaporization of early-formed Cr2O3 in combination with accelerated chromia growth induced by the H2O. Rapid Cr consumption leads to the nucleation and rapid growth of iron oxides. On the contrary, Ni–Cr alloys are less affected by the presence of H2O and excess O2. The difference between Fe–Cr and Ni–Cr alloys is not clear but is postulated to involve less acceleration of chromia growth by water vapor for the latter group of alloys.

The decomposition of simple chlorinated organic compounds comprising benzene derivatives (mono, di and tri-chlorobenzenes) as the imitation substance of polychlorobiphenyls (PCBs) was investigated by using basic molten salts in order to establish a safe, simple and highly efficient decomposition process for PCBs. Chlorobenzen liquid or the solution was injected into basic molten salts (KOH―K 2 CO 3 or NaOH― Na 2 CO 3 ) at 573―973 K with imitation air, and the residual concentration of chlorobenzenes in the exhaust was measured after the decomposition treatment. The decomposition efficiency reached to very high of 99.9999% in an optimum condition. The decomposition efficiencies of chlorobenzenes were affected by the flow rate of the air and the initial concentration of chlorobenzen in the gas mixture. The complete destruction for benzene derivatives required excess oxygen condition.

Delafossite-type CuLnO2 (Ln = La, Y) was synthesized and investigated their oxygen storage capacity (OSC) under oxidation/reduction cycle. CuLaO2 was synthesized by heating at 1000 °C for 6 h in N2 flow and CuYO2 was synthesized by heating of Cu2Y2O5 at 1190 °C for 1 h in N2 flow. The oxygen storage capacity values of CuLaO2 and CuYO2 at lower temperature were larger than that of CeO2-based materials which is used as a promoter of an automobile catalyst. The stability of delafossite-type CuLnO2 under cyclic oxidation/reduction atomosphere was investigated using XRD analysis. During the OSC measurement up to 700 °C, CuLaO2 decomposed to La2CuO4 and Cu2O. CuYO2 also partially decomposed to Y2O3, Cu2Y2O5 and Cu2O. These results suggest that oxidative decomposition of CuLnO2 occurred at high temperature. In lower temperature range, delafossite-type CuLaO2+x containing excess oxygen existed in both oxidative and reductive atmosphere and it partially decomposed during a hundred of oxidation/reduction cycles.

We have synthesized La 2− x Sm x CuO 4 (0 ⩽ x ⩽ 2.0) with the Nd 2 CuO 4 structure via a molten alkaline hydroxide route at temperatures as low as 400–480 °C. After reduction heat treatment in vacuum at 600–750 °C for removal of excess oxygen atoms at the interstitial apical site, superconductivity with T c = 20–24 K was observed in the samples with x = 0.05–1.0. The superconducting volume fraction is nearly 100% for x = 0.3–0.7. Our results demonstrate that La 2− x Sm x CuO 4 with no nominal carrier doping is a bulk superconductor.

Pt/TiO2 catalysts prepared by sol–gel and wetness impregnation methods were investigated for the selective catalytic reduction (SCR) of NO by C3H6 in the presence of excess oxygen. The characterist...

Δημοσίευση σε επιστημονικό περιοδικό Summarization: In the present work, two different methods of catalyst promotion, the electrochemical promotion (EP) and the conventional promotion (CP), were comparatively applied on a catalytic system of significant environmental and practical importance: the N2O reduction by hydrocarbons (alkanes and alkenes), in the presence or absence of O2, over Pd catalysts. A galvanic cell of the type Pd/K+-conducting β″-Al2O3/Au was constructed for the application of the EP concept whereas the CP concept was investigated via a series of highly dispersed Pd/γ-Al2O3 catalysts, conventionally promoted (by impregnation) with K modifier. Given that EP is a straightforward, efficient and in situ way for investigating the effect of a promoter on a catalytic system, the present study is dealing with its prior use as a rapid “research tool” for exploring the effect of K promoter on the catalytic system under consideration. Subsequently, the insight obtained from EP studies is applied to the design of conventional catalysts' composites, i.e. Pd/γ-Al2O3 catalysts conventionally promoted by K at loadings indicated from EP studies. For the system investigated, the optimal promoter loading was in the range of ∼ 0.45–0.55, in terms of K-coverage. In this range of K-loadings significant enhancement on de-N2O activity was obtained under reducing conditions using both methods of K-promotion. However, in the presence of excess oxygen in the reaction mixture the effect of K-promotion was less pronounced, independently of the reducing agent used. Παρουσιάστηκε στο: Solid State Ionics

Three-beam X-ray diffraction (XRD) has been measured using the Renninger scheme in epitaxial ZnO layers with various thicknesses and degrees of crystal perfection. The integral intensity of three-beam XRD reflections has been analyzed and compared to that of two-beam reflections in the Bragg and Laue geometry. It is established that, for thin ZnO layers grown in the presence of excess oxygen, the integral intensity of three-beam diffraction peaks and Laue reflections is much smaller than that for layers of the same thickness grown in the presence of excess zinc. This fact is explained by the formation of a textured sublayer in the former case.