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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

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

Background Oxygen therapy is routinely administered to mechanically ventilated patients. However, there remains uncertainty about the optimal oxygen titration target in patients with the acute respiratory distress syndrome (ARDS). Methods Prospectively identified adult patients meeting the Berlin definition of ARDS between 1st January 2014 and 13th December 2016 were analyzed. Oxygen exposure variables were collected at 6-hourly intervals. The primary exposure was the average time-weighted partial pressure of arterial oxygen (PaO2) calculated over a maximum of 7 days from meeting ARDS criteria. The primary outcome was ICU mortality. Univariable and multivariable logistic regression analyses were performed to assess the impact of exposure variables on clinical outcomes. Results are presented as odds ratio [95% confidence interval]. Results 202 patients were included in the final analysis. Overall ICU mortality was 31%. The average time-weighted PaO2 during the first 7 days of ARDS was similar between non-survivors and survivors (11.3 kPa [10.2, 12.5] (84.8 mmHg [76.5, 93.8]) vs. 11.9 kPa [10.9, 12.6] (89.3 mmHg [81.8, 94.5]); p = 0.08). In univariable and multivariable analysis, average time-weighted PaO2 demonstrated a U-shaped relationship with ICU mortality. There was a similar relationship identified with hospital mortality. Conclusions In patients with ARDS, the predicted probability of both ICU and hospital mortality was lowest when the average time-weighted PaO2 was between 12.5 and 14 kPa (93.8–105.0 mmHg), suggesting this is a reasonable oxygenation target for clinicians to aim for.

By combining experimental observations on Gd doped fuel with a theoretical understanding, the variation in thermal conductivity with Gd concentration and accommodation mechanism has been modelled. Four types of Gd accommodation mechanisms have been studied. In UO2−x, isolated substitutional Gd3+ ions are compensated by oxygen vacancies and { 2 Gd U ’ : V O ⋅ ⋅ } × defect clusters. In UO2, isolated substitutional Gd3+ ions are compensated by U5+ ions and { Gd U ’ : U U ⋅ } × defect clusters. The results indicate that defect clusters can be considered as less effective phonon scatterers and therefore result in less thermal conductivity degradation. The thermal conductivity predicted for UO2 with { G d U ′ : U U ⋅ } × defect clusters is in good agreement with experimental data for UO2 with 5 wt% Gd2O3. This supports the previous theoretical results that Gd is accommodated through defect clusters { Gd U ’ : U U ⋅ } × in UO2 in the presence of excess oxygen.

We report a series of layered superconductors, anti-ThCr$_2$Si$_2$-type $RE_2$O$_2$Bi ($RE$ = rare earth), composed of electrically conductive Bi square nets and magnetic insulating $RE_2$O$_2$ layers. The superconductivity was induced by separating Bi square nets as a result of excess oxygen incorporation, irrespective of the presence of magnetic ordering in $RE_2$O$_2$ layers. Intriguingly, the transition temperature of all $RE_2$O$_2$Bi including nonmagnetic Y$_2$O$_2$Bi was approximately scaled by the unit cell tetragonality ($c$/$a$), implying a key role of relative separation of the Bi square nets to induce the superconductivity.

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.

Studie je zaměřena na účinnost katalytických reakcí La-Fe/AC pro selektivní katalytickou redukci (SCR) NO oxidem uhelnatým (CO). Zvýšený podíl lanthanu vedl ke zvýšení poměru Fe2+/Fe3+ a množství povrchových kyslíkových vakancí (SOV), což zvýšilo i účinnost katalýzy. Po implementaci promotorů La3-Fe1/aktivní uhlík (AC) došlo ke změně katalytické aktivity v důsledku pozměněné elektronické struktury. Zvýšení poměru Fe2+/Fe3+ po implementaci promotoru je pravděpodobně důsledkem dodatečné synergetické interakce M (mangan nebo cerium) a Fe skrze redoxní rovnováhu M(3+)+ Fe(3+)↔M(4+)+ Fe(2+). Tato interakce pravděpodobně zvýšila účinnost redoxního cyklu, zlepšila tvorbu SOV, usnadnila rozklad NO a zrychlila proces CO-SCR. Zvýšené množství kyslíku zlepšilo tvorbu C(O) komplexů a aktivaci kovových center katalytického materiálu. Materiál Mn@La3-Fe1/AC vykazuje skvělou přeměnu NO s účinností 93,8% při 400°C a v přítomnosti 10% kyslíku. Vysoká katalytická účinnost MnOx a přenos náboje usnadněný pomocí Mn3+ a Mn4+ může zvýšit množství SOV a zlepšit katalytické vlastnosti.CZ redukce NO; CO-SCR; Mn promotor; La-Fe/AC katalytický materiál; zvýšená koncentrace kyslíku; znečištění vzduchu 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 M(3+)+ Fe(3+)↔M(4+)+ Fe(2+). 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 °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.

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 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.

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.

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.

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

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 .

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 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.

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.

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

Resumen La producción de microalgas ha tomado importancia en los últimos años, debido a sus diversos usos en la producción de biocombustibles, alimentación tanto humana como animal, y en biorremediación; es por ello que, la optimización de las tecnologías destinadas a su producción resulta necesaria. En el presente trabajo se implementó y comparó un fotobiorreactor tubular helicoidal con un sistema abierto tradicional para la producción de Nannochloropsis oculata en el Parque Marino del Pacífico, Puntarenas, Costa Rica. En la construcción del fotobiorreactor se utilizó 100 metros de manguera transparente de 1” con un volumen total de 55 L, una estructura cilíndrica metálica (diámetro 0,67 m y 1,90 m de altura), un colector (0,12 m diámetro y 1,25 m de altura) de 15 L de volumen, un desgasificador para eliminar los excedentes de oxígeno, se instaló un aireador para la mezcla del medio de cultivo y finalmente se colocaron ocho lámparas de 32 W alrededor de la estructura metálica. Mientras que el sistema abierto estaba conformado por tanques de fibra de vidrio de 2 m3 de volumen y una manguera para la aireación. Se obtuvo como resultado que con el fotobiorreactor tubular se logró aumentar la densidad algal de 7,5 a 134x 106 cel/mL, la microalga logró permanecer en este sistema hasta 20 días mientras que, con el sistema abierto común solamente de 4 a 5 días, redujo el área requerida para la producción de la microalga en un 91% y al reducir las horas hombre necesarias para su funcionamiento logró reducir en un 18% los costos económicos. Abstract Microalgae production has become important in recent years due to its diverse uses in the industry (biofuels, human and animal feeding, and bioremediation), because is important the optimization of the technologies destined to its production is necessary. A tubular photobioreactor with a traditional open system for production of Nannochloropsis oculata in the Parque Marino del Pacífico, Puntarenas, Costa Rica, was compared. In the construction of the photobioreactor was used 100 meters of transparent hose 1 “with a total volume of 55 L, a cylindrical structure (diameter 0, 67 m and 1, 90 m height), a manifold (0, 12 m diameter and 1, 25 m height) of 15 L of volume, a degasser to remove excess oxygen, an aerator was installed for the corresponding mixing of the culture medium and finally eight lamps of 32 W were placed around the metallic structure. While the open system consisted of glass fiber tanks 2 m3 and a hose for aeration. Results showed with tubular photobioreactor it was possible to increase the algal density from 7, 5 to 134 x 106 cells / mL, the microalga managed to remain in the system for up to 20 days while with the common open system only 4 to 5 days, the new equipment reduced the area required for microalgae production by 91% and by reducing the man hours required for its operation managed to reduce economic costs by 18%.

Selective catalytic reduction of NO by hydrogen was studied over Cr modified Pt/ZSM-35 catalysts. The preparation process greatly influenced catalytic activity and sample prepared by co-impregnation method exhibits the best activity. In situ DRIFT studies revealed that on Pt–Cr/ZSM-35, (1) new Pt-NO δ+ and NO species adsorbed on Pt were detected upon NO + O 2 adsorption; (2) much more ammonia species were formed under reaction condition. Cr addition not only enhanced the adsorption of NO x but also promoted the formation of surface NH 4 + species, which should be the origin of promotional effect of Cr on Pt/ZSM-35 for H 2 -SCR reaction.

The bomb calorimeter is laboratory equipment which serves to calculate the value of combustion heat or heat capacity of a sample in excess oxygen combustion. This study aims to determine the effect of using bomb calorimeter on science process skill of physics students. Influences include the effectiveness of using the equipment and knowing the improvement of students' science process skills before and after using tools. The sample used simple random sampling with one group pretest-posttest research design. The instrument that used is written test that adjusts with science process skills aspect. Analysis of the effectiveness of bomb calorimeter showed useful result 87.88%, while the study of science skill improvement showed n-gain value 0.64 that is the medium category.

A new concept of a novel “dual bed” configuration of NH 3 and CO-SCR catalytic system (NH 3 -CO-SCR), comprising Cu/Beta as top catalyst bed for NH 3 -SCR and WO 3 /Ir/SiO 2 as bottom catalyst bed for CO-SCR, is described in this article. The combined catalytic system provides high NO reduction efficiency, in a broad temperature range (160–600 °C). The NO conversion over the combined catalytic system reached up to 98% between 280 and 320 °C, as compared to the system using only Cu/Beta or WO 3 /Ir/SiO 2 with sole NH 3 or CO as reductant. Furthermore, the combined catalytic system shows high NO reduction efficiency even in the presence of lower concentrations of NH 3 and CO. Thus, the potential advantage of this combined system is that it can effectively reduce NO during situations when NH 3 and CO concentration is expected to fluctuate in real driving conditions which could potentially lead to NH 3 and CO slip issues.

A series of TiO 2 supported catalysts with 0.5 wt% noble metal (Pt, Pd, Rh and Ru) were used for the low-temperature selective catalytic reduction (SCR) of NO with propylene in the presence of excess oxygen. Under an atmosphere of 150 ppm NO, 150 ppm C 3 H 6 and 18 vol% O 2 (GHSV 72,000 h −1 ), the Pt/TiO 2 was found to be the most active catalyst giving a complete C 3 H 6 conversion and 63% NO x reduction simultaneously at 140 °C. The enhanced activity of Pt/TiO 2 may be associated to its outstanding activities in the temperature-programmed oxidation (TPO) of NO to NO 2 and C 3 H 6 to CO 2 .

The catalytic activity in the oxidation of hydrogen (in the gaseous state in the presence of excess oxygen) has been studied for samples of Pt(Pd)/Ta2O5−x, formed by reduction with hydrogen. The samples obtained had greater activity than the traditional catalysts Pt(Pd)/Al2O3. According to X-ray diffraction analysis and electron microscopic studies, Ta2O5−x becomes amorphous with the formation of more reduced non-stoichiometric oxygen-deficient tantalum oxides with a surface layer of catalyst.

A series of iridium-supported catalysts with various Ir loadings were prepared by impregnation method. The support materials used were ZSM-5, γ-Al2O3, and SiO2. The Ir loadings examined were 0.02%, 0.1%, 1%, and 5% (w). The behavior of the catalysts for the NO reaction was analyzed by means of temperature programmed reaction (TPR) experiments. The reactions of NO over iridium include the oxidation of NO to NO2 and the reduction of NO to N2 or N2O. The iridium catalysts promote the reactions of NO and the catalytic activity increases with the increase of the Ir loadings. Further, support materials have a little effect on the catalytic activity. When the loading was less than 0.1%, the catalytic activity was found to be dependent on the property of support materials and the activity order was Ir/ZSM-5Ir/γ-Al2O3Ir/SiO2; when the loading was higher than 0.1%, the order of catalytic activity for NO oxidation was Ir/ZSM-5Ir/SiO2Ir/γ-Al2O3, which was correlated with Ir dispersion on the surface of support materials, and the order of catalytic activity for NO reduction was Ir/γ-Al2O3Ir/SiO2Ir/ZSM-5, which was attributed to the adsorbed-dissociation of NO2. Ir/γ-Al2O3 catalyst was more beneficial for the NO reduction than Pt/γ-Al2O3 catalyst.

We have fabricated truly single-crystal BSCCO thin films of the quality of traveling-solvent-floating-zone single crystals by using a double side cleaving technique. The thicknesses of the cleaved thin films thus obtained ranges from 20 nm to 100 nm. These films are found to adsorb or desorb oxygen very easily at a relatively low annealing temperature of 200 to 300degC. When a cleaved film is annealed in Argon at 300degC for 10 min, it changes to an insulator without any trace of superconducting transition. When this film is subsequently annealed in oxygen at 300degC , it exhibits a sharp superconducting transition at about 90 K. When the film is subjected to these process repeatedly, the film changes from an insulator to a superconductor quite reversibly. We have measured in-plane resistivity and the Hall coefficient systematically in a wide doping range for this thin film BSCCO single crystals.

A new simple and reliable procedure was developed for the spectrophotometric determination of nitrogen(II) oxide. The procedure is based on the determination of excess oxygen after its reaction with NO. Alkaline solutions of thiourea dioxide were used for the determination of oxygen. It was found that the decomposition of an alkaline solution of thiourea dioxide under aerobic conditions is accompanied by the formation of dithionite, and its concentration is proportional to the concentration of oxygen in the solution. The absorbance of the resulting dithionite was measured at 315 nm. The solutions obeyed Beer’s law at oxygen concentrations of 1 × 10–5 – 1.5 × 10–3 M. The analytical range for NO was 1 × 10–5 –1.5 × 10–3 M. The proposed procedure was also used for the determination of nitrogen(II) oxide in aqueous-ethanolic solutions.

Pd (0.1 wt.%)/Al2O3 catalyst was found to be active for the selective NO reduction employing H2 (NO conversion>90%) under excess O2 at low temperatures (110–190 °C) with good N2 selectivity (about 70%). The selectivity towards N2O was sensitive to the reaction conditions and decreased as the temperature was raised. The maximum selectivity to NH3 occurred at 190 °C. The selectivity to N2O was inhibited greatly by O2 at low temperatures. Gaseous O2 promoted the selectivity to N2 as well as the generation of adsorbed NH species in comparison to the reactions without O2. In situ diffuse reflectance IR spectroscopy (DRIFTS) measurements suggested that there was competition between H2 and other adsorbed species such as nitrates and water at low temperatures, and the rate determining step may be the adsorption and activation of H2 over the catalyst.

The roles of aliovalent Ca(II)-for-Y(III) substitution and high-pressure-oxygen annealing in the process of "superconducterizing" the Co-based layered copper oxide, CoSr2(Y1-xCax)Cu2O7+d (Co-1212), were investigated. The as-air-synthesized samples up to x = 0.4 were found essentially oxygen stoichiometric (-0.03, 16 pages, 6 figures, submitted to Solid State Communications