On the development of creep damage constitutive equations: modified hyperbolic sine law for minimum creep strain rate and stress and creep fracture criterion based on cavity area fraction along grain boundaries

Abstract: This paper reports 1) the latest development and application of modified hyperbolic sine law for minimum creep strain rate and stress for both low Cr and high Cr steels, and 2) the development of creep fracture criterion based on cavity area fraction along grain boundary for high Cr steel. This work is part of the fundamental development of creep damage constitutive equations which were identified through a critical literature review. In the former the application of the new law results in an improved fitting; in the latter, a new creep fracture criterion based on cavity area fraction along grain boundary was derived and quantitatively calibrated using the latest detailed cavity nucleation and growth kinetics models for high Cr steel. Furthermore, this paper revealed the trend of nucleation rate coefficient with stress, and the trend of creep life time coefficient with stress, which provide reliable and universal prediction capabilities. This paper contributes to the specific knowledge on the minimum creep strain rate and stress function, the development of a scientific sound and novel creep rupture criterion based on the cavity area fraction along grain boundary for high Cr steel, and the provision of creep damage/life prediction tools

Temperature and pressure behavior of the emission bands from Mn-, Cu-, and Eu-doped ZnS nanocrystals

The Mn-, Cu- and Eu-doped ZnS nanocrystals (NC) were analyzed for temeperature and pressure dependence of photoluminescence. The thermal quenching behavior of characteristic emission bands reflected nature of different transition mechanisms. The energies of Mn-orange and Eu-green emissions were observed to be weakly dependent on temperature. The results show strong interaction between excited state of Eu2+ ions and conduction band of ZnS which was responsible for positive pressure coefficient.published_or_final_versio

Heterogeneous activation of peroxymonosulfate by a biochar-supported Co3O4 composite for efficient degradation of chloramphenicols

Herein, a new peroxymonosulfate (PMS) activation system was established using a biochar (BC)-supported Co3O4 composite (Co3O4-BC) as a catalyst to enhance chloramphenicols degradation. The effects of the amount of Co3O4 load on the BC, Co3O4-BC amount, PMS dose and solution pH on the degradation of chloramphenicol (CAP) were investigated. The results showed that the BC support could well disperse Co3O4 particles. The degradation of CAP (30 mg/L) was enhanced in the Co3O4-BC/PMS system with the apparent degradation rate constant increased to 5.1, 19.4 and 7.2 times of that in the Co3O4/PMS, BC/PMS and PMS-alone control systems, respectively. Nearly complete removal of CAP was achieved in the Co3O4-BC/PMS system under the optimum conditions of 10 wt% Co3O4 loading on BC, 0.2 g/L. Co3O4-BC, 10 mM PMS and pH 7 within 10 min. The Co3O4/BC composites had a synergistic effect on the catalytic activity possibly because the conducting BC promoted electron transfer between the Co species and HSO5- and thus accelerated the Co3+/Co(2+)redox cycle. Additionally, over 85.0 +/- 1.5% of CAP was still removed in the 10th run. Although both SO4 center dot- and OH center dot were identified as the main active species, SO4 center dot- played a dominant role in CAP degradation. In addition, two other chloramphenicols, i.e., florfenicol (FF) and thiamphenicol (TAP), were also effectively degraded with percentages of 86.4 +/- 13% and 71.8 +/- 1.0%, respectively. This study provides a promising catalyst Co3O4-BC to activate PMS for efficient and persistent antibiotics degradation. (C) 2019 Elsevier Ltd. All rights reserved

Why some causative ‘give’ constructions develop beyond the passive to also form the unaccusative : evidence from Southern Min dialects

The conference was organized by Linguistic Society of Hong Kong.2011-2012 > Academic research: refereed > Refereed conference paperOther Versio

Experimental procedure for the characterization of turbocharger s waste-gate discharge coefficient

[EN] Nowadays, the turbocharger has become one of the key components for automotive spark-ignition engine improvements (fed with both liquid and gaseous fuels), as a support for the boosting and downsizing concept to reduce fuel consumption and exhaust emission. In gasoline engines, the usage of the waste-gate valve typically regulates the maximum boost pressure in the turbocharger system, to protect the engine and the turbocharger at high engine speeds. To improve the transient response at low engine speeds two-stage turbocharger is widely used. Two-stage systems are composed of several valves to regulate the flow to control the boosting of the system. Like, a by-pass valve between the turbines, a check valve between the compressor and a waste-gate valve for the low-pressure turbines. This paper deals with a methodology for characterizing the discharge coefficient of an electronic waste-gate valve in the turbocharger. To estimate the gas flow over the same in one-dimensional models, an empirical model is correlated and validated. For this, a constant stream experimental work has been carried out on a test rig at different valve position openings, with high turbine inlet temperatures. Finally, an optimal MAP of discharge coefficient has been drawn out through interpolation method, which can integrate into the full one-dimensional turbocharged engine model system, to calculate the actual mass flow through the waste-gate valve.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was partially funded by FEDER and Government of Spain through Project TRA2016-79185-R.Serrano, J.; Arnau Martínez, FJ.; Tiseira ., AO.; Samala, V. (2017). Experimental procedure for the characterization of turbocharger s waste-gate discharge coefficient. Advances in Mechanical Engineering. 9(10):1-9. https://doi.org/10.1177/1687814017728242S1991

Folate cycle enzyme MTHFD1L confers metabolic advantages in hepatocellular carcinoma

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Mimetic-enzyme fluorescence immunoassay using a thermal phase separating polymer

Poly-N-isopropylacrylamide (PNIP), a water-soluble, thermally precipitated synthetic polymer, has been conjugated together with a monoclonal antibody and utilized as a novel separation method for an immunoassay. PNIP precipitates out of water above a critical temperature of 31 degrees C, enabling a polymer-bound immune complex to be separated from the solution. These characteristics were used to develop a novel polymer-mimetic enzyme immunoassay method for determination of alpha-1-fetoprotein (AFP) with hemin as a labeling reagent to catalyze the reaction of p-hydroxyphenyl acetic acid (HPA) and hydrogen peroxide in alkaline medium. After a one-step competitive immunoreaction, the polymer-antibody-antigen-hemin conjugate moiety was determined by coupling the fluorogenic reaction of HPA and hydrogen peroxide, The calibration graph for AFP was linear over the range of 0-380 ng cm(-3) with a detection limit of 1.0 ng cm(-3). This method combines some advantages of both homogeneous and heterogeneous immunoassays, and has been applied to determine AFP in human blood serum with satisfactory results