8,196 research outputs found
In situ photogalvanic acceleration of optofluidic kinetics: a new paradigm for advanced photocatalytic technologies
A multiscale-designed optofluidic reactor is demonstrated in this work, featuring an overall reaction rate constant of 1.32 s¯¹ for photocatalytic decolourization of methylene blue, which is an order of magnitude higher as compared to literature records. A novel performance-enhancement mechanism of microscale in situ photogalvanic acceleration was found to be the main reason for the superior optofluidic performance in the photocatalytic degradation of dyes as a model reaction
Orthogonal array design for biodiesel production optimization: using ultrasonic-assisted transestification of Camelina sativa L. Crantz oil
Bioenergy Technology (BE): 0234Camelina seed oil has recently attracted great interest as a low-cost feedstock for biodiesel production because of its high oil content and environmental benefits. In the present study, an orthogonal array design was used to optimize the biodiesel production from camelina seed oil using ultrasonic-assisted transesterification. Four relevant factors are investigated: methanol to oil ratio, catalyst concentration, reaction time and temperature to obtain maximum fatty acid methyl ester (FAME) yield of biodiesel. An OA25 matrix was employed to study the effect of the four factors, by which the effect of each factor was estimated using statistical analysis. Based on the results of the statistical analysis after the orthogonal experiments, maximal biodiesel FAME yield (98.6 %) was obtained under the conditions of 8:1 methanol to oil molar ratio, 1.25 wt.% catalyst concentration (KOH), 50 min reaction time, and 55 ℃ reaction temperature. Other properties of the optimized biodiesel, including density, kinematic viscosity, and acid value, were conformed to the relevant ASTM and EN biodiesel standards and thus the optimized biodiesel from camelina oil basically qualified to be used as diesel fuel.published_or_final_versionThe World Renewable Energy Congress (WREC 2011), Linköping, Sweden, 8-13 May 2011. In Linköping Electronic Conference Proceedings, 2011, ECP57, v. 1, p. 79-8
The relationships among pre-service mathematics teachers’ beliefs about mathematics, mathematics teaching, and use of technology in China
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Leaky Bucket-Inspired Power Output Smoothing with Load-Adaptive Algorithm
The renewables will constitute an important part of the future smart grid. As a result, the growing portion of renewable generation in the power grid will bring challenges to the operations of the power grid because of the fluctuation and intermittency properties of renewables. In order to make the operations of power grid stable and reliable, the power outputs from renewable energy sources must be smoothed. In this paper, we propose a scheme inspired from the idea of the leaky bucket mechanism for smoothing the power output from a renewable energy system. In our proposed method, the settings of energy storage size and power output level have significant effects on the system performance and thus needs to be determined. An optimization framework is thus proposed for storage and power output planning of the renewable energy system. To operate our proposed scheme practically, a load-adaptive power smoothing algorithm is devised aiming to match the power output level with the actual load in the grid. Our simulation studies show that the proposed algorithm can reduce the operation cost comparing to other algorithms and maintain high renewable energy utilization.postprin
Electric vehicle charging station placement
Transportation electrification is one of the essential components in the future smart city planning and electric vehicles (EVs) will be integrated into the transportation system seamlessly. Charging stations are the main source of energy for EVs and their locations are critical to the accessibility of EVs in a city. They should be carefully situated so that an EV can access a charging station within its driving range and cruise around anywhere in the city upon being recharged. In this paper, we formulate the Electric Vehicle Charging Station Placement Problem, in which we minimize the total construction cost subject to the constraints for the charging station coverage and the convenience of the drivers for EV charging. We study the properties of the problem, especially its NP-hardness, and propose an efficient greedy algorithm to tackle the problem. We perform a series of simulation whose results show that the greedy algorithm can result in solutions comparable to the mixed-integer programming approach and its computation time is much shorter. © 2013 IEEE.Link_to_subscribed_fulltextpostprin
Laser spectroscopy of NiBr: Ground and low-lying electronic states
Rotationally resolved near-infrared spectroscopic study of electronic transition of low-lying states of NiBr was reported using the technique of laser vaporization/reaction with supersonic cooling and laser induced fluorescence (LIF) spectroscopy. The reaction of laser ablated nickel atoms and ethyl bromide produced NiBr molecules. Least squares fit of rotationally resolved transition lines yielded accurate molecular constants.published_or_final_versio
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