Utilization of single-chamber microbial fuel cells as renewable power sources for electrochemical degradation of nitrogen-containing organic compounds

By employing promising single-chamber microbial fuel cells (MFCs) as renewable power sources, an aerated electrochemical system is proposed and for nitrogen-containing organic compounds (pyridine and methyl orange) removals. Carbon felt performed the best as electrode material while lower initial contaminant concentration and lower initial pH value could improve the performance. A degradation efficiency of 82.9% for pyridine was achieved after 360 min electrolysis with its initial concentration of 200 mg/L, initial pH of 3.0 and applied voltage of 700 mV. Mechanisms study implied that indirect electrochemical oxidation by generated hydrogen peroxide was responsible for their degradation. This study provides an alternative utilization form of low bioelectricity from MFCs and reveals that applying it to electrochemical process is highly-efficient as well as cost-effective for degradation of nitrogen-containing organic compounds. (C) 2015 Elsevier B.V. All rights reserved.National Natural Science Foundation of China (NSFC) [21307117, 41440025]; Research Fund for the Doctoral Program of Higher Education of China [20120022120005]; Beijing Excellent Talent Training Project [2013D009015000003]; Beijing Higher Education Young Elite Teacher Project [YETP0657]; Fundamental Research Funds for the Central Universities [2652015226, 2652015131]SCI(E)[email protected]

Asynchronous Stabilization of Nonlinear Markov Jump Singularly Perturbed Systems via Fuzzy Static Output Feedback Control

This study focuses on the static output feedback control of nonlinear Markov jump singularly perturbed systems within the framework of Takagi–Sugeno fuzzy approximation. From a practical point of view, the phenomenon of asynchronous switching between the plant and the controller is considered and characterized by a finite piecewise-homogenous Markov process. Particularly, for facilitating the controller synthesis, the closed-loop system is transformed into a fuzzy Markov jump singularly perturbed descriptor system by adopting descriptor representation. In order to fully accommodate the system features, an appropriate stochastic Lyapunov function is constructed. Afterwards, by combining Finsler’s lemma, the mean square exponential admissibility of the system is analyzed. The conditions ensuring the existence of the predesigned controller are given and further solved by designing a brief search algorithm. Finally, a typical circuit system is used to demonstrate the application potential of the developed control technology and the effectiveness of the control strategy

Enhanced microbial chromate reduction using hydrogen and methane as joint electron donors

Hydrogen and methane commonly co-exist in aquifer. Either hydrogen or methane has been individually utilized as electron donor for bio-reducing chromate. However, little is known whether microbial chromate reduction would be suppressed or promoted when both hydrogen and methane are simultaneously supplied as joint electron donors. This study for the first time demonstrated microbial chromate reduction rate could be accelerated by both hydrogen and methane donating electrons. The maximum chromate reduction rate (4.70 ± 0.03 mg/L·d) with a volume ratio of hydrogen to methane at 1:1 was significantly higher than that with pure hydrogen (2.53 ± 0.02 mg/L·d) or pure methane (2.01 ± 0.02 mg/L·d) as the sole electron donor (p < 0.01). High-throughput 16S rRNA gene amplicon sequencing detected potential chromate reducers (e.g., Spirochaetaceae, Delftia and Azonexus) and hydrogenotrophic bacteria (e.g., Acetoanaerobium) and methane-metabolizing microorganisms (e.g., Methanobacterium), indicating that these microorganisms might play important roles on microbial chromate reduction using both hydrogen and methane as electron donors. Abundant hupL and mcrA genes responsible for hydrogen oxidation and methane conversion were harbored, together with chrA gene for chromate reduction. More abundant extracellular cytochrome c and intracellular NADH were detected with joint electron donors, suggesting more active electron transfers

Optimal Relay Location for Resource-Limited Energy-Efficient Wireless Communication

In the design of wireless networks, techniques for improving energy efficiency and extending network lifetime have great importance, particularly for defense and civil/rescue applications where resupplying transmitters with new batteries is not feasible. In this paper we study a method for improving the lifetime of wireless networks by minimizing the length of the longest edge in the interconnecting tree with deploying additional relay nodes.Let P={p1, ..., pn} be a set of n terminals in the Euclideanplane. For a positive integer k, the bottleneck Steinertree problem (BSTP) asks to find a Steiner tree with atmost k Steiner points such that the length of the longest edge in the tree is minimized. We give a ratio - sqrt(3) + e polynomial time approximation algorithm for BSTP, where e is an arbitrary positive number.Keywords:wireless networks, power efficient, approximation algorithms, Steiner tree, bottleneck Steiner tree

J Glob Optim DOI 10.1007/s10898-006-9017-0 ORIGINAL ARTICLE

Optimal relay location for resource-limited energy-efficient wireless communicatio

Variation of carbohydrates and macronutrients during the flowering stage in canola (Brasscia napus L.) plants with contrasting seed oil content

Determination of dynamics of the physiological traits that affect the seed oil content in canola (Brassica napus L.) is essential for high seed oil content breeding programs. The main purpose of the present experiments was to explore the relationship between seed oil content and carbohydrates, N and P content of various canola aboveground tissues during flowering stage using two recombinant inbred lines RILS. Two field experiments were performed simultaneously in both 2010 and 2011. In experiment 1, seed yield and quality were compared between two RILs with contrasting seed oil content, that is, high oil content line (HOCL) and low oil content line (LOCL) at 50.4% and 41.4%, respectively. In experiment 2, our results showed the HOCL produced markedly more biomass in the reproductive organs by 9.9% and 30% at 35 days after anthesis (DAA) in 2010 and 2011, respectively. Furthermore, compared with LOCL, HOCL accumulated higher fructose, sucrose, and P content in the reproductive organs at the late flowering stage, with an average increment of 85.0%, 31.1%, and 12.4% at 35 DAA, respectively. However, the mean N content in the reproductive organs of HOCL was 17.27% lower than that in LOCL at 35DAA. These results reveal the importance of the higher reproductive organ C/N ratio in the regulation of the higher seed oil content of HOCL. Therefore, the C/N ratio of the reproductive organ may be a useful physiological indicator to screen canola lines for high seed oil content in future breeding program

Broadcasting Policy, Creative Compliance, and the Myth of Civil Society in China

This paper looks at arguments framing civil society debates and questions the usefulness of civil society models in understanding how media policy is made and implemented in China. The key argument is that viewing the state-society relationship in China through a Western optic obviates the distinctive differences between the autonomous civil society of liberal-democracies and Chinese social relations. This does not mean that civil society is a redundant concept. It can be usefully applied to describe economically driven political and social change in China. However, its capacity to explain how cultural and media policy is formulated is limited