Electrochemical Investigation of High-Performance Dye-Sensitized Solar Cells Based on Molybdenum for Preparation of Counter Electrode

In order to improve the photocurrent conversion efficiency of dye-sensitized solar cells (DSSCs), we studied an alternative conductor for the counter electrode and focused on molybdenum (Mo) instead of conventional fluorine-doped tin oxide (FTO). Because Mo has a similar work function to FTO for band alignment, better formability of platinum (Pt), and a low electric resistance, using a counter electrode made of Mo instead of FTO lead to the enhancement of the catalytic reaction of the redox couple, reduce the interior resistance of the DSSCs, and prevent energy-barrier formation. Using electrical measurements under a 1-sun condition (100 mW/cm(2), AM 1.5), we determined that the fill factor (FF) and photocurrent conversion efficiency (eta) of DSSCs with a Mo electrode were respectively improved by 7.75% and 5.59% with respect to those of DSSCs with an FTO electrode. Moreover, we have investigated the origin of the improved performance through surface morphology analyses such as scanning electron microscopy and electrochemical analyses including cyclic voltammetry and impedance spectroscopy

Neuroprotective and anti-oxidant effects of caffeic acid isolated from Erigeron annuus leaf

<p>Abstract</p> <p>Background</p> <p>Since oxidative stress has been implicated in a neurodegenerative disease such as Alzheimer's disease (AD), natural antioxidants are promising candidates of chemopreventive agents. This study examines antioxidant and neuronal cell protective effects of various fractions of the methanolic extract of <it>Erigeron annuus </it>leaf and identifies active compounds of the extract.</p> <p>Methods</p> <p>Antioxidant activities of the fractions from <it>Erigeron annuus </it>leaf were examined with [2,2-azino-bis(3-ethylbenz thiazoline-6-sulfonic acid diammonium salt)] (ABTS) and ferric reducing antioxidant power (FRAP) assays. Neuroprotective effect of caffeic acid under oxidative stress induced by H₂O₂was investigated with [3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) and lactate dehydrogenase (LDH) assays.</p> <p>Results</p> <p>This study demonstrated that butanol fraction had the highest antioxidant activity among all solvent fractions from methanolic extract <it>E. annuus </it>leaf. Butanol fraction had the highest total phenolic contents (396.49 mg of GAE/g). Caffeic acid, an isolated active compound from butanol fraction, showed dose-dependent <it>in vitro </it>antioxidant activity. Moreover, neuronal cell protection against oxidative stress induced cytotoxicity was also demonstrated.</p> <p>Conclusion</p> <p><it>Erigeron annuus </it>leaf extracts containing caffeic acid as an active compound have antioxidative and neuroprotective effects on neuronal cells.</p

Northern Barbados accretionary prism: Structure, deformation, and fluid flow interpreted from 3D seismic and well-log data

We reanalyzed 3D seismic reflection and logging-while-drilling data from the toe of the northern Barbados accretionary prism to interpret structure, deformation, and fluid flow related to subduction processes. The seafloor amplitude and coherence reveal an abrupt change in the thrust orientation from NNE at the thrust front and north and NNW about 5 km west of the thrust front. These thrust sets are separated by a triangular-shaped quiet area, which may represent a zone of low strength. The northeast-trending band of strong negative amplitude and high coherence in the décollement, known to be an interval of arrested consolidation, overlaps the quiet area, suggesting that the arrested consolidation may be related to the lack of thrust imbrication, and thus, vertical drainage for fluid in the accretionary prism. Fractal analysis of the décollement and top of the subducting oceanic basement indicates that the relief of the décollement correlates with the topography of the oceanic basement. Differential compaction of the underthrust sediment overlying the rugged oceanic basement, together with the basement faults that penetrate into the décollement probably caused relief or even faulting in the décollement

Restructuring TCAD System: Teaching Traditional TCAD New Tricks

Traditional TCAD simulation has succeeded in predicting and optimizing the device performance; however, it still faces a massive challenge - a high computational cost. There have been many attempts to replace TCAD with deep learning, but it has not yet been completely replaced. This paper presents a novel algorithm restructuring the traditional TCAD system. The proposed algorithm predicts three-dimensional (3-D) TCAD simulation in real-time while capturing a variance, enables deep learning and TCAD to complement each other, and fully resolves convergence errors.Comment: In Proceedings of 2021 IEEE International Electron Devices Meeting (IEDM