18,181 research outputs found

    A geometrical theory for {111} <hkl> recrystallisation texture formation in cold rolled IF steel

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    The introduction of a conditional deformating banding into BCC rolling texture modellling has produced a clue as too the origins of the {111} texture as it develops from the γ fibre material. OIM has reveqaled that deformation bands are present in many deformed γ grains, which therefore produced the gometrical condition for successful nucleation of rotated ND material by either subgrain growth or SIBM. Clearly the roles of solutes and precipitates have to be established in this deformation microstructure.published_or_final_versio

    Radio variability of 1st 3-months Fermi blazars at 5 GHz: affected by interstellar scintillation?

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    Blazars from the first-three-months Fermi-AGN list were observed with the Urumqi 25m radio telescope at 5GHz in IDV (Intra-Day Variability) mode and inter-month observation mode. A significant correlation between the flux density at 5GHz and the gamma-ray intensity for the Fermi-LAT detected blazars is seen. There is a higher IDV detection rate in Fermi detected blazars than those reported for other samples. Stronger variability appears at lower Galactic latitudes; IDV appears to be stronger in weaker sources, indicating that the variability is affected by interstellar scintillation.Comment: 4 pages, 4 figures, in proceedings of 'Multiwavelength Variability of Blazars' in Guangzhou Uni. of China, 22-24, Sep. 2010, to appear in JA

    Linkage and mapping analyses of the no glue egg gene Ng in the silkworm (Bombyx mori L.) using simple sequence repeats (SSR) markers

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    In the silkworm, Bombyx mori, no glue egg is mainly controlled by Ng (No glue) gene, which is located on the 12th chromosome. Owning to a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progenies were used for linkage analysis and mapping of the Ng gene based on the simple sequence repeats (SSR) linkage map using silkworm strains H9 and P50, which are Ng mutant and normal to egg, respectively. The Ng gene was found to be linked to three SSR markers. Using a reciprocal BC1M cross, we constructed a linkage map of 36.4 cM, with Ng mapped at 15.9 cM and the nearest SSR marker at a distance of 7.4 cM. Based on fine genome map of domesticated silkworm (B. mori), the result of Kaikoblast show that the physical distance between the near markers (containing Ng gene) is 181.7 Kb. Further analysis show that BGIBMGA005833, BGIBMGA005835 and BGIBMGA005836 are closer to Ng, and the BGIBMGA005835 is nearest to Ng, which physical distance is 44 Kb.Key words: Gene location, linkage analysis, microsatellite, Ng, silkworm

    Nitrous Oxide Production in Co-Versus Counter-Diffusion Nitrifying Biofilms

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    For the application of biofilm processes, a better understanding of nitrous oxide (N 2 O) formation within the biofilm is essential for design and operation of biofilm reactors with minimized N 2 O emissions. In this work, a previously established N 2 O model incorporating both ammonia oxidizing bacteria (AOB) denitrification and hydroxylamine (NH 2 OH) oxidation pathways is applied in two structurally different biofilm systems to assess the effects of co-and counter-diffusion on N 2 O production. It is demonstrated that the diffusion of NH 2 OH and oxygen within both types of biofilms would form an anoxic layer with the presence of NH 2 OH and nitrite (), which would result in a high N 2 O production via AOB denitrification pathway. As a result, AOB denitrification pathway is dominant over NH 2 OH oxidation pathway within the co-and counter-diffusion biofilms. In comparison, the co-diffusion biofilm may generate substantially higher N 2 O than the counter-diffusion biofilm due to the higher accumulation of NH 2 OH in co-diffusion biofilm, especially under the condition of high-strength ammonium influent (500 mg N/L), thick biofilm depth (300 μm) and moderate oxygen loading (∼1-∼4 m 3 /d). The effect of co-and counter-diffusion on N 2 O production from the AOB biofilm is minimal when treating low-strength nitrogenous wastewater

    Model-Based Feasibility Assessment of Membrane Biofilm Reactor to Achieve Simultaneous Ammonium, Dissolved Methane, and Sulfide Removal from Anaerobic Digestion Liquor

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    In this study, the membrane biofilm reactor (MBfR) is proposed to achieve simultaneous removal of ammonium, dissolved methane, and sulfide from main-stream and side-stream anaerobic digestion liquors. To avoid dissolved methane stripping, oxygen is introduced through gas-permeable membranes, which also from the substratum for the growth of a biofilm likely comprising ammonium oxidizing bacteria (AOB), anaerobic ammonium oxidation (Anammox) bacteria, denitrifying anaerobic methane oxidation (DAMO) microorganisms, aerobic methane oxidizing bacteria (MOB), and sulfur oxidizing bacteria (SOB). A mathematical model is developed and applied to assess the feasibility of such a system and the associated microbial community structure under different operational conditions. The simulation studies demonstrate the feasibility of achieving high-level (>97.0%), simultaneous removal of ammonium, dissolved methane, and sulfide in the MBfRs from both main-stream and side-stream anaerobic digestion liquors through adjusting the influent surface loading (or hydraulic retention time (HRT)) and the oxygen surface loading. The optimal HRT was found to be inversely proportional to the corresponding oxygen surface loading. Under the optimal operational conditions, AOB, DAMO bacteria, MOB, and SOB dominate the biofilm of the main-stream MBfR, while AOB, Anammox bacteria, DAMO bacteria, and SOB coexist in the side-stream MBfR to remove ammonium, dissolved methane, and sulfide simultaneously

    Nitrous oxide production in a granule-based partial nitritation reactor: A model-based evaluation

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    Sustainable wastewater treatment has been attracting increasing attentions over the past decades. However, the production of nitrous oxide (N2O), a potent GHG, from the energy-efficient granule-based autotrophic nitrogen removal is largely unknown. This study applied a previously established N2O model, which incorporated two N2O production pathways by ammonia-oxidizing bacteria (AOB) (AOB denitrification and the hydroxylamine (NH 2 OH) oxidation). The two-pathway model was used to describe N2O production from a granule-based partial nitritation (PN) reactor and provide insights into the N2O distribution inside granules. The model was evaluated by comparing simulation results with N2O monitoring profiles as well as isotopic measurement data from the PN reactor. The model demonstrated its good predictive ability against N2O dynamics and provided useful information about the shift of N2O production pathways inside granules for the first time. The simulation results indicated that the increase of oxygen concentration and granule size would significantly enhance N2O production. The results further revealed a linear relationship between N2O production and ammonia oxidation rate (AOR) (R2 = 0.99) under the conditions of varying oxygen levels and granule diameters, suggesting that bulk oxygen and granule size may exert an indirect effect on N2O production by causing a change in AOR

    Developing N-Rich Carbon from C₃N₄-Polydopamine Composites for Efficient Oxygen Reduction Reaction

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    Nitrogen-rich carbon-based materials are amongst the most promising electrocatalysts for the oxygen reduction reaction (ORR) and/or the oxygen evolution reaction (OER). The introduction of nitrogen within the carbonaceous framework generates catalytic active sites and alters the electrical conductivity. However, the synthesis of these materials often involves long processes and severe reaction conditions which yield a low concentration of nitrogen (N) functionalities. Herein, we present a facile method for the synthesis of N-rich carbon by carbonizing a carbon nitride (C3N4)-polydopamine composite (CNDA) which can readily be prepared by room temperature self-polymerisation of dopamine in the presence of C3N4. The intrinsically high N content in C3N4 leads to a highly N-doped carbon. The CNDA catalyst synthesized at 900 °C contained 12.5 at% of N, enhancing both the ORR and OER catalytic activities through a 4-e− dominated pathway, providing a comparable E1/2 and a remarkably improved diffusion-limited current to the other reported N-doped carbon catalysts. When used as an air-cathode in a zinc-air battery, this CNDA catalyst possessed stable discharge-charge cycling performance for 216 h, outperforming the Pt/C standard. This work opens a promising platform for the development of template-free processes for the synthesis of non-metal and nitrogen-rich carbon materials which are attractive for metal-air batteries and fuel cells

    Age-related differences in adaptation during childhood: The influences of muscular power production and segmental energy flow caused by muscles

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    Acquisition of skillfulness is not only characterized by a task-appropriate application of muscular forces but also by the ability to adapt performance to changing task demands. Previous research suggests that there is a different developmental schedule for adaptation at the kinematic compared to the neuro-muscular level. The purpose of this study was to determine how age-related differences in neuro-muscular organization affect the mechanical construction of pedaling at different levels of the task. By quantifying the flow of segmental energy caused by muscles, we determined the muscular synergies that construct the movement outcome across movement speeds. Younger children (5-7 years; n = 11), older children (8-10 years; n = 8), and adults (22-31 years; n = 8) rode a stationary ergometer at five discrete cadences (60, 75, 90, 105, and 120 rpm) at 10% of their individually predicted peak power output. Using a forward dynamics simulation, we determined the muscular contributions to crank power, as well as muscular power delivered to the crank directly and indirectly (through energy absorption and transfer) during the downstroke and the upstroke of the crank cycle. We found significant age × cadence interactions for (1) peak muscular power at the hip joint [Wilks' Lambda = 0.441, F(8,42) = 2.65, p = 0.019] indicating that at high movement speeds children produced less peak power at the hip than adults, (2) muscular power delivered to the crank during the downstroke and the upstroke of the crank cycle [Wilks' Lambda = 0.399, F(8,42) = 3.07, p = 0.009] indicating that children delivered a greater proportion of the power to the crank during the upstroke when compared to adults, (3) hip power contribution to limb power [Wilks' Lambda = 0.454, F(8,42) = 2.54, p = 0.023] indicating a cadence-dependence of age-related differences in the muscular synergy between hip extensors and plantarflexors. The results demonstrate that in spite of a successful performance, children construct the task of pedaling differently when compared to adults, especially when they are pushed to their performance limits. The weaker synergy between hip extensors and plantarflexors suggests that a lack of inter-muscular coordination, rather than muscular power production per se, is a factor that limits children's performance ranges
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