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Nitrogen dioxide (NO2) is a pollutant that directly harm the human respiratory system, lead to inflammation, as well as to form the secondary aerosol pollutants. The main NO2 sources, combustion or thermal processes, were well controlled. However, the metal etching operation in semiconductor industry emits flue gases with reddish-brown NO2 fume that leads to visibility reduction, acidic odor, as well as negative effects on human health. In this study, a stream of flue gases with low NO2 (230 ± 10 ppm) and NO (50 ppm) concentrations were conducted to pass through an activated carbon-packed fixed bed for analyzing the adsorptive conversion behavior of NO2 by the activated carbon (AC) at room temperature. The repeated adsorption test was carried out by washing the regenerated waste carbon with a caustic solution and water and drying. Results propose that at the beginning of adsorption, nitrogen dioxide combined with carbon to form NO and desorbed from carbon surface. The net adsorptive conversion removal capacity of NO2 by the virgin AC and regenerated AC was 224 and 155 mg g–1 AC, respectively. Regeneration restored around 70–75% of effective surface area, pore volume, and adsorptive conversion capacity of the virgin AC. Leached caustic solution obtained from the carbon regeneration contained only nitrate and the phenomena indicates the adsorbed -C2(ONO2) hydrolyzed following the Eq. (2) -C2(ONO2) + H2O → 3 -C* + -C(O) + 2 HNO3, where -C* denotes active site on the carbon surface.

A new digital scanning approach is proposed and its feasibility is demonstrated. The Cascaded Mirror Array applies an array of reflectors, with each reflector movable between discretized angular positions controlled by digitized electrical signals, to process a light beam by cascaded reflections to generate desired deflections of a light beam. An Uneven-Leg Tilting mechanism was devised to provide a very significant mechanical reduction ratio so that it can be used to generate very small tilt angles by comparatively large, finite displacements that can be easily created. A 4-bit 1D scanner prototype, built by simple non-MEMS methods, demonstrated point-to-point scanning at 0.0125° resolution from 1 to several hundred Hz. Studies based on finite element simulations suggest that by increasing electromagnetic driving force and reducing the size and mass of the prototype construction operating frequency up to several thousand Hz can be achieved. The new approach has the potential of making low-cost light-weight robust high speed scanners.

Vanadium redox flow battery (VRFB) is a rechargeable battery, which has attracted attention as a next-generation electrochemical energy storage system. It is widely known that achieving high performance in terms of power density is critical for the commercialization of VRFBs. The aim of this paper is to propose a computational design approach for automatically generating an optimized flow field design of a VRFB to achieve high performance without relying on the designer’s intuition. To realize this, we focus on generating a freeform configuration of the flow field in a VRFB via topology optimization, which is known as a powerful design tool that is based on numerical optimization. In this study, to improve the mass transfer effect in a VRFB, we formulate the topology optimization problem as a maximization problem of the electrode surface concentration in the negative electrode during the charging process. We demonstrate through numerical investigation that a topology-optimized flow field can be obtained. As a result, it is revealed that the interdigitated flow field is an optimal flow field of the VRFB under the investigated operating conditions.

In this study, a reinforcement learning based power assisted method is proposed for pedelec, which is a Light Electric Vehicle (LEV) driven by a human's pedal force and electric motor. The proposed method adaptively chooses appropriate assisted power according to the environmental changes. By adaptively adjusting the assisted power after learning for pedelec, not only energy utilization is improved but comfort of riding for pedalist is also satisfied. Simulations of the proposed method on pedelec powered by battery are performed. Experimental results demonstrate that the proposed method satisfies the requirement of comfort of riding and achieve better energy utilization by comparing with other conventional power assisted methods.

Evodia rutaecarpa is commonly used as an anti-inflammatory drug in traditional Chinese medicine. We previously identified four bioactive compounds (dehydroevodiamine (I), evodiamine (II), rutaecarpine (III), and synephrine (IV)) from the ethanol extract of E. rutaecarpa, but their effects and mechanism(s) of action remain unclear. To study the anti-inflammatory potential and the possible underlying mechanism(s), their effects on phorbol-12-myristate-13-acetate (PMA)- and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced reactive oxygen species production in neutrophils was studied, as well as lipopolysaccharide (LPS)-induced nitric oxide (NO) production and inducible NO synthetase (iNOS) expression in microglial cells. The ethanol extract of E. rutaecarpa displayed potent antioxidative effects against both PMA- and fMLP-induced reactive oxygen species production in neutrophils (with IC50 values of around 2.7-3.3 microg/ml). Although less potent than the ethanol extract of E. rutaecarpa, compounds I-IV all concentration-dependently inhibited PMA- and fMLP-induced reactive oxygen species production, with compound IV consistently being the most potent agent among these active components. The antioxidative effects of the ethanol extract of E. rutaecarpa and these compounds were partially due to inhibition (10%-33%) of NADPH oxidase activity, a predominant reactive oxygen species-producing enzyme in neutrophils, and to a minor extent to their direct radical-scavenging properties. The ethanol extract of E. rutaecarpa also inhibited LPS-induced NO production (with an IC50 of around 0.8 microg/ml) and iNOS upregulation in microglial cells that was partially mimicked by compounds I, II, and III, but not compound IV. Our results suggest that the ethanol extract of E. rutaecarpa and its four bioactive components all exhibited anti-inflammatory activities which could be partially explained by their different potentials for inhibiting NADPH oxidase-dependent reactive oxygen species and/or iNOS-dependent NO production in activated inflammatory cells.