Chung-Ang University

About: Chung-Ang University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Thin film. The organization has 13381 authors who have published 26978 publications receiving 416735 citations. The organization is also known as: CAU & Chung.

Ultrathin sandwich-like MoS2@N-doped carbon nanosheets for anodes of lithium ion batteries

Abstract: In this work, we report on a simple and scalable process to synthesize the core–shell nanostructure of MoS2@N-doped carbon nanosheets (MoS2@C), in which polydopamine is coated on the MoS2 surface and is then carbonized. An intensive investigation using transmission electron microscopy and Raman spectroscopy reveals that the as-synthesized MoS2@C possesses a nanoscopic and ultrathin layer of MoS2 sheets with a thin and conformal coating of carbon layers (∼3 nm). The MoS2@C demonstrates a superior electrochemical performances as an anode material for lithium ion batteries compared to exfoliated MoS2 and bulk MoS2 samples. This unique core–shell structure is capable of delivering an excellent Li+ ion charging–discharging process as follows: a specific capacity as high as 1239 mA h g−1, a high rate capability even at a high current rate of 10 A g−1 while retaining 597 mA h g−1, and a good cycle stability over 200 cycles at a high current rate of 2 A g−1.

Biodegradation of naphthalene, BTEX, and aliphatic hydrocarbons by Paraburkholderia aromaticivorans BN5 isolated from petroleum-contaminated soil.

Abstract: To isolate bacteria responsible for the biodegradation of naphthalene, BTEX (benzene, toluene, ethylbenzene, and o-, m-, and p-xylene), and aliphatic hydrocarbons in petroleum-contaminated soil, three enrichment cultures were established using soil extract as the medium supplemented with naphthalene, BTEX, or n-hexadecane Community analyses showed that Paraburkholderia species were predominant in naphthalene and BTEX, but relatively minor in n-hexadecane Paraburkholderia aromaticivorans BN5 was able to degrade naphthalene and all BTEX compounds, but not n-hexadecane The genome of strain BN5 harbors genes encoding 29 monooxygenases including two alkane 1-monooxygenases and 54 dioxygenases, indicating that strain BN5 has versatile metabolic capabilities, for diverse organic compounds: the ability of strain BN5 to degrade short chain aliphatic hydrocarbons was verified experimentally The biodegradation pathways of naphthalene and BTEX compounds were bioinformatically predicted and verified experimentally through the analysis of their metabolic intermediates Some genomic features including the encoding of the biodegradation genes on a plasmid and the low sequence homologies of biodegradation-related genes suggest that biodegradation potentials of strain BN5 may have been acquired via horizontal gene transfers and/or gene duplication, resulting in enhanced ecological fitness by enabling strain BN5 to degrade all compounds including naphthalene, BTEX, and short aliphatic hydrocarbons in contaminated soil

Effectiveness of atomoxetine and methylphenidate for problematic online gaming in adolescents with attention deficit hyperactivity disorder

Abstract: Objective There is a high prevalence of problematic online gaming in adolescents with attention deficit hyperactivity disorder (ADHD). In the current study, we compared the effectiveness of atomoxetine (ATM) and methylphenidate (MPH) on problematic online gaming in adolescents with ADHD. Methods We recruited 86 adolescents diagnosed with ADHD together with Internet gaming disorder. These participants were divided into two treatment groups: 44 participants were treated with MPH for 12 weeks, and 42 participants were treated with ATM for 12 weeks. Results During the 3-month study period, the MPH group showed greater improvement in Korean ADHD rating scale scores than the ATM group. The ATM group showed greater improvement in Child Depression Inventory scores than the MPH group. However, Young Internet Addiction Scale and Behavioral Inhibition & Activation Scales score changes did not differ significantly between the MPH and ATM groups. In both groups, changes in Young Internet Addiction Scale scores were positively correlated with the changes in Behavioral Inhibition & Activation Scales scores. Conclusions Both MPH and ATM reduced the severity of Internet gaming disorder symptoms, and this reduction was correlated with impulsivity reduction, which also resulted from both ADHD medications. These findings suggest impulsivity plays a critical role in the development of problematic online gaming.

Approximation-based adaptive control of uncertain non-linear pure-feedback systems with full state constraints

Abstract: This study proposes an adaptive approximation-based control approach for non-linear pure-feedback systems in the presence of full state constraints. Completely non-affine non-linear functions are considered and assumed to be unknown. The dynamic surface design based on integral barrier Lyapunov functionals is provided to achieve both the desired tracking performance and the constraints satisfaction, in consideration of the full-state-constrained non-affine non-linearities. In this design procedure, simple sufficient conditions for choosing control gains, which can be checked off-line, are established to guarantee the feasibility of the controller. The function approximation technique is employed to estimate unknown non-linearities induced from the controller design procedure where the adaptive laws using the projection operator are designed to ensure the boundedness of the function approximators in the feasibility conditions. It is shown that all the signals in the closed-loop system are uniformly ultimately bounded and the tracking error converges to an adjustable neighbourhood of the origin while all state variables always remain in the constrained state space.