Effect of Indium-Tin Oxide Surface Modifications on Hole Injection and Organic Light Emitting Diode Performance

Ph.DDOCTOR OF PHILOSOPH

Finite edge-transitive dihedrant graphs

AbstractIn this paper, we first prove that each biquasiprimitive permutation group containing a regular dihedral subgroup is biprimitive, and then give a classification of such groups. The classification is then used to classify vertex-quasiprimitive and vertex-biquasiprimitive edge-transitive dihedrants. Moreover, a characterization of valencies of normal edge-transitive dihedrants is obtained, and some classes of examples with certain valences are constructed

Evaluation of n-Butane Gas Adsorption Performance of Composite Adsorbents Used for Carbon Canister

AbstractA novel adsorbent design technique was proposed to composite adsorbent used for carbon canister for improving the adsorption performance of n-butane gas. Two kinds of activated carbons were tested to produce composite adsorbents and evaluate the performance by measuring the adsorption isotherms of butane and pore structure characteristics. The volume-based amount of adsorption for the adsorbents prepared at sodium silicate solution concentration of 0.1wt% is 1.04 and 1.53 times that of the raw activated carbons (AC1 and AC2). The packing density of the composite adsorbent increased with the increase of sodium silicate solution concentration

Long-term antiplatelet therapy in medically managed non-ST-segment elevation acute coronary syndromes: The EPICOR Asia study

OBJECTIVES: To describe long-term antithrombotic management patterns (AMPs) in medically managed Asian patients with non-ST-segment myocardial infarction (NSTEMI) or unstable angina (UA). BACKGROUND: Current guidelines support an early invasive strategy in NSTEMI and UA patients, but many are medically managed, and data are limited on long-term AMPs in Asia. METHODS: Data were analyzed from medically managed NSTEMI and UA patients included in the prospective, observational EPICOR Asia study (NCT01361386). Survivors to hospital discharge were enrolled (June 2011 to May 2012) from 8 countries/regions across Asia. Baseline characteristics and AMP use up to 2 years post-discharge were collected. Outcomes were major adverse cardiovascular events (MACE: myocardial infarction, ischemic stroke, and death) and bleeding. RESULTS: Among 2289 medically managed patients, dual antiplatelet therapy (DAPT) use at discharge was greater in NSTEMI than in UA patients (81.8% vs 65.3%), and was significantly associated with male sex, positive cardiac markers, and prior cardiovascular medications (p < 0.0001). By 2 years, 57.9% and 42.6% of NSTEMI and UA patients, respectively, were on DAPT. On multivariable Cox regression analysis, risk of MACE at 2 years was most significantly associated with older age (HR [95% CI] 1.85 [1.36, 2.50]), diagnosis of NSTEMI vs UA (1.96 [1.47, 2.61]), and chronic renal failure (2.14 [1.34, 3.41]), all p ≤ 0.001. Risk of bleeding was most significantly associated with region (East Asia vs Southeast/South Asia) and diabetes. CONCLUSIONS: Approximately half of all patients were on DAPT at 2 years. MACE were more frequent in NSTEMI than UA patients during follow-up

Study on using hydrogen and ammonia as fuels: Combustion characteristics and NOx formation

This paper evaluates the potential of hydrogen (H-2) and ammonia (NH3) as carbon-free fuels. The combustion characteristics and NOx formation in the combustion of H-2 and NH3 at different air-fuel equivalence ratios and initial H-2 concentrations in the fuel gas were experimentally studied. NH3 burning velocity improved because of increased amounts of H-2 atom in flame with the addition of H-2. NH3 burning velocity could be moderately improved and could be applied to the commercial gas engine together with H-2 as fuels. H-2 has an accelerant role in H-2-NH3-air combustion, whereas NH3 has a major effect on the maximum burning velocity of H-2-NH3-air. In addition, fuel-NOx has a dominant role and thermal-NOx has a negligible role in H-2-NH3-air combustion. Thermal-NOx decreases in H-2-NH3-air combustion compared with pure H-2-air combustion. NOx concentration reaches its maximum at stoichiometric combustion. Furthermore, H-2 is detected at an air-fuel equivalence ratio of 1.00 for the decomposition of NH3 in flame. Hence, the stoichiometric combustion of H-2 and NH3 should be carefully considered in the practical utilization of H-2 and NH3 as fuels. H-2 as fuel for improving burning performance with moderate burning velocity and NOx emission enables the utilization of H-2 and NH3 as promising fuels. Copyright (C) 2014 John Wiley & Sons, Ltd

Pathfinder: Protein folding pathway prediction based on conformational sampling.

The study of protein folding mechanism is a challenge in molecular biology, which is of great significance for revealing the movement rules of biological macromolecules, understanding the pathogenic mechanism of folding diseases, and designing protein engineering materials. Based on the hypothesis that the conformational sampling trajectory contain the information of folding pathway, we propose a protein folding pathway prediction algorithm named Pathfinder. Firstly, Pathfinder performs large-scale sampling of the conformational space and clusters the decoys obtained in the sampling. The heterogeneous conformations obtained by clustering are named seed states. Then, a resampling algorithm that is not constrained by the local energy basin is designed to obtain the transition probabilities of seed states. Finally, protein folding pathways are inferred from the maximum transition probabilities of seed states. The proposed Pathfinder is tested on our developed test set (34 proteins). For 11 widely studied proteins, we correctly predicted their folding pathways and specifically analyzed 5 of them. For 13 proteins, we predicted their folding pathways to be further verified by biological experiments. For 6 proteins, we analyzed the reasons for the low prediction accuracy. For the other 4 proteins without biological experiment results, potential folding pathways were predicted to provide new insights into protein folding mechanism. The results reveal that structural analogs may have different folding pathways to express different biological functions, homologous proteins may contain common folding pathways, and α-helices may be more prone to early protein folding than β-strands

Efficient nano-regional photocatalytic heterostructure design via the manipulation of reaction site self-quenching effect

Heterostructural photocatalysts with rationally aligned energy bands have been proved effective in diminishing the recombination of photo-induced excitons, thus leading to enhanced photocatalytic performance. However, the critical role of charge carrier behaviors and their quenching pathway in determining the overall photocatalytic performance are still not fully explored, which severely hindered the development for efficient photocatalysts. Herein, to further explore the essential principles of photocatalysis with heterostructures, a representative nano-regional photocatalytic heterostructure was constructed through uniform decoration of visible light activable BiOI nanodots on TiO2 nanorod assembled microflowers. With which as a well-known prototype of conventional heterostructures, a possible photocatalytic performance annihilation channel via reaction site self-quenching effect in photocatalytic heterostructures was experimentally evidenced for the first time. Based on our experimental results, we evidenced that excessive decoration with BiOI nanodots would result in severe self-quenching of their photocatalytic sites through highly probable charge carrier recombination between migrating electrons along TiO2 nanorods and reactive holes in adjacent BiOI nanodots. Such fundamental and experimental discovery is not limited to the current model and would shed light on the development of novel nano-regional heterostructures with high photocatalysis performance.Nanyang Technological UniversityWe acknowledge the support from the Surface Technology Group of Singapore Institute of Manufacturing Technology including experimental and characterization equipment. We also thank the Advanced Environmental Biotechnology Centre of Nanyang Environment and Water Research Institute for the financial support (AEBC M060380006.70602200)

Numerical study on effect of oxygen content in combustion air on ammonia combustion

As a key parameter for a fuel in real combustion development, burning velocity of NH3 which is usually low limits its application in the energy device. In this study, the combustion of NH3 at oxygen enriched condition has been proposed as a novel method for improving NH3 combustion. The oxygen concentration in the combustion air was varied from 21% to 30%. The results show that O-2-enriched combustion has positive effects on both laminar burning velocity and adiabatic flame temperature of NH3. The maximum burning velocity of NH3 is 38.6 cm/s at O-2 content of 30%, which is approximately 2.6 times the value obtained at an O-2 content of 21%, mainly due to the increased reaction rates of OH, H, O, and NH2 radicals in the reaction zone at higher O-2 contents. NO emissions increase with an increase in the O-2 content of the combustion air. Whereas, the reactions between NO and surplus NH2, NH and N radicals cause more NO consumption especially at fuel-rich conditions, showing the potential in reducing NO emission in NH3-air combustion. Therefore, O-2-enriched combustion is a suitable method for improving NH3 combustion when NH3 is utilized as fuel. (C) 2015 Elsevier Ltd. All rights reserved

Research on Combustion and Emission Characteristics of Ammonia under Preheating Conditions

The present study focuses on determining the potential applicability of ammonia (NH3) as a carbon-free alternative fuel through numerical simulations. The combustion and emissions characteristics of premixed NH3-air flame at preheating conditions were numerically investigated. The burning velocity and all species mole fraction were determined using the Miller and Bowman and the Reductive Konnov mechanism. The results show that both the equivalence ratio and preheating temperature have important effects on the laminar burning velocity and adiabatic flame temperature of NH3. The reaction rate of production and mole fraction of H, O, and OH radicals, together with nitrogen radicals such as NH2, NH, and N in the reaction zone, increases as the preheating temperature is increased from 298 to 573 K. Although NO concentrations in the exhaust gas increased with increasing preheating temperature under fuel-lean conditions, they could be maintained at a reasonably low level at all preheating temperatures, mainly due to the increased reduction reaction of NO with NH2, NH, N radicals. The main N radical formation in the NH3-air combustion originates from NH3 rather than N-2, which indicates that the N-2 dilution effect of NH3-air flame is negligible for NO formation. Furthermore, the equivalence ratio has a dominant effect on NO yields, because of the higher reduction reaction and lower flame temperature at higher equivalence ratio conditions, leading to a lower formation of HNO, which indicates a potential in reducing NO emissions in NH3 combustion. Therefore, the preheating temperature and equivalence ratio should be given sufficient consideration in practical operations to minimize NO formation in combustion of NH3 as a clean fuel