The smallest quaternary ammonium salts with ether groups for high-performance electrochemical double layer capacitors

Electrochemical double layer capacitors (EDLCs) are energy storage devices that have been used for a wide range of electronic applications. In particular, the electrolyte is one of the important components, directly related to the capacitance and stability. Herein, we first report a series of the smallest quaternary ammonium salts (QASs), with ether groups on tails and tetrafluoroborate (BF4) as an anion, for use in EDLCs. To find the optimal structure, various QASs with different sized head groups and ether-containing tail groups were systematically compared. Comparing two nearly identical structures with and without ether groups, QASs with oxygen atoms showed improved capacitance, proving that ions with oxygen atoms move more easily than their counterparts at lower electric fields. Moreover, the ether containing QASs showed low activation energy values of conductivities, leading to smaller IR drops during the charge and discharge processes, resulting in an overall higher capacitance

Dissociating stable nitrogen molecules under mild conditions by cyclic strain engineering

All quiet on the nitrogen front. The dissociation of stable diatomic nitrogen molecules (N-2) is one of the most challenging tasks in the scientific community and currently requires both high pressure and high temperature. Here, we demonstrate that N-2 can be dissociated under mild conditions by cyclic strain engineering. The method can be performed at a critical reaction pressure of less than 1 bar, and the temperature of the reaction container is only 40 degrees C. When graphite was used as a dissociated N* receptor, the normalized loading of N to C reached as high as 16.3 at/at %. Such efficient nitrogen dissociation is induced by the cyclic loading and unloading mechanical strain, which has the effect of altering the binding energy of N, facilitating adsorption in the strain-free stage and desorption in the compressive strain stage. Our finding may lead to opportunities for the direct synthesis of N-containing compounds from N-2

Highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites: Pt-free, highly efficient, and durable counter electrodes for dye-sensitized solar cells

We report the preparation of highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites which show Pt-like dye-sensitized solar cell (DSSC) efficiency and remarkable long-term durability as DSSC counter electrodes.close413

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

Preferences on Security Issues and Ideological Competitions: A Case of the Korean National Assembly

This article examines the distinct features of the ideological thinking and their impact on ideological competitions among the members of Korean National Assembly (KNA). In particular, it analyzes the influence of preferences on security issues on the formation of ideological self-identification and internal competitions of the KNA. By applying factor analysis, it shows that the issue attitudes among the members of the KNA do not converge into the ideological self-identification. In addition, preferences on security issues can be distinguished from the ideological self-identification among the member of the KNA and have an independent impact on their legislative voting behavior. These results imply that a more valid understanding of the legislative behavior among the members of the KNA could develop by specifying issue attitudes independently from the ideological self-identification.OAIID:RECH_ACHV_DSTSH_NO:T201634977RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A080262CITE_RATE:.153DEPT_NM:국제학과EMAIL:[email protected]_YN:YY

Introduction: South Korean Politics after Transitions

South Korea is best known for its economic development, democratic consolidation, proactive civil society, and, more recently, for its emergence as a cultural powerhouse. The country has experienced various transitions including political, democratic, economic, societal, and demographic and, thus, its contemporary politics are considerably different from its traditional patterns through the process of responding to these transitions. Overall, South Korea and its politics are far distant from the outdated images and grand perspectives associated with them, which tended to underappreciate the complex and diversified nature of South Korean politics. By critically evaluating the contemporary politics of South Korea in their areas of expertise, contributors to this handbook point out that South Korean politics have been moving in the direction of introducing the principle of checks and balances over the South Korean presidential system. Different groups, including political parties and civil society, have diverse channels to make their voices heard. Strong state-led developmentalism has been replaced by a thriving market-driven economy with heterogenous demands. Instances and practices of international cooperation and mutual learning have eroded the unity of political elites, now divided into competing groups with different reference points behind their policy orientations

Risk-Based Prioritization of Sewer Pipe Inspection from Infrastructure Asset Management Perspective

The escalating number of aging sewer pipes necessitates an infrastructure asset management approach to achieve an efficient budget allocation for maintenance. This study suggests a risk-based prioritization framework for sewer pipe inspection considering the predicted condition of sewer pipes and the criticality of the economic, social and environmental impacts associated with them. The results from both models can be used to evaluate the risk of sewer pipes by classification into risk groups. A risk matrix is used for the classification, and it divides the sewer pipes into five risk groups. The results of this study show an improvement in the accuracy of finding sewer pipes in a bad condition using this framework. The condition prediction model can successfully find sewer pipes with a bad condition with over 70% precision. High-risk sewer pipes are highlighted using the differences in the environmental features as well as in the physical features associated with other sewer pipes. Additionally, through the combination of both the condition and criticality of sewer pipes, the framework systemically prioritizes needed maintenance for sewer pipes with a very bad condition. This prioritization framework is expected to help the process of deciding which sewer pipes should be prioritized within a constrained budget