2,911 research outputs found

    Treatment of DomesticWastewaterwith Simultaneous Electricity Generation in Microbial Fuel Cell under Continuous Operation

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    In order to apply microbial fuel cell (MFC) process more practically in wastewater treatment, both power generation and removal of chemical oxygen demand (COD) were examined in an air-cathode MFC fed with domestic wastewater under continuous operation. At a hydraulic retention time (HRT) of 2.0 h, the air-cathode MFC was able to generate electricity from domestic wastewater with a maximum power density of P = 103 2 mWm–2 (5772 mW m–3) and an average Coulomb efficiency (CE) of 18.4%; meanwhile, to achieve an average COD removal up to 71 %. Increasing HRT from 2h to 10–30 h was found to be more effective for COD removal, however, instability in voltage output was also observed. An increased power generation of 1734mW m–2 (9648 mW m–3) was obtained with the aid of NaCl addition at a mass fraction of w = 2.4 %, because of an elevated conductivity of the solution with accord internal resistance of 227 0

    The NF-κB subunit c-Rel regulates Bach2 tumour suppressor expression in B-cell lymphoma

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    The REL gene, encoding the NF-κB subunit c-Rel, is frequently amplified in B-cell lymphoma and functions as a tumour-promoting transcription factor. Here we report the surprising result that c-rel–/– mice display significantly earlier lymphomagenesis in the c-Myc driven, Eμ-Myc model of B-cell lymphoma. c-Rel loss also led to earlier onset of disease in a separate TCL1-Tg-driven lymphoma model. Tumour reimplantation experiments indicated that this is an effect intrinsic to the Eμ-Myc lymphoma cells but, counterintuitively, c-rel–/– Eμ-Myc lymphoma cells were more sensitive to apoptotic stimuli. To learn more about why loss of c-Rel led to earlier onset of disease, microarray gene expression analysis was performed on B cells from 4-week-old, wild-type and c-rel–/– Eμ-Myc mice. Extensive changes in gene expression were not seen at this age, but among those transcripts significantly downregulated by the loss of c-Rel was the B-cell tumour suppressor BTB and CNC homology 2 (Bach2). Quantitative PCR and western blot analysis confirmed loss of Bach2 in c-Rel mutant Eμ-Myc tumours at both 4 weeks and the terminal stages of disease. Moreover, Bach2 expression was also downregulated in c-rel–/– TCL1-Tg mice and RelA Thr505Ala mutant Eμ-Myc mice. Analysis of wild-type Eμ-Myc mice demonstrated that the population expressing low levels of Bach2 exhibited the earlier onset of lymphoma seen in c-rel–/– mice. Confirming the relevance of these findings to human disease, analysis of chromatin immunoprecipitation sequencing data revealed that Bach2 is a c-Rel and NF-κB target gene in transformed human B cells, whereas treatment of Burkitt's lymphoma cells with inhibitors of the NF-κB/IκB kinase pathway or deletion of c-Rel or RelA resulted in loss of Bach2 expression. These data reveal a surprising tumour suppressor role for c-Rel in lymphoma development explained by regulation of Bach2 expression, underlining the context-dependent complexity of NF-κB signalling in cancer

    Superconductivity at 11.3 K induced by cobalt doping in CeOFeAs

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    Pure phases of a new oxyarsenide superconductor of the nominal composition CeOFe0.9Co0.1As was successfully synthesized by solid state reaction in sealed silica ampoules at 1180 C. It crystallizes in the layered tetragonal ZrCuSiAs type structure (sp gp P4/nmm) with lattice parameter of a = 3.9918(5) angstrom and c = 8.603(1) angstrom. A sharp superconducting transition is observed at 11.31 K with an upper critical field of 45.22 T at ambient pressure. The superconducting transition temperature is drastically lowered (~ 4.5, 4.9 K) on increasing the concentration (x = 0.15, 0.2) of cobalt

    Reactive inkjet printing of functional silk stirrers for enhanced mixing and sensing

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    Stirring small volumes of solution can reduce immunoassay readout time, homogenize cell cultures, and increase enzyme reactivity in bioreactors. However, at present many small scale stirring methods require external actuation, which can be cumbersome. To address this, here, reactive inkjet printing is shown to be able to produce autonomously rotating biocompatible silk-based microstirrers that can enhance fluid mixing. Rotary motion is generated either by release of a surface active agent (small molecular polyethylene glycol) resulting in Marangoni effect, or by catalytically powered bubble propulsion. The Marangoni driven devices do not require any chemicals to be added to the fluid as the "fuel," while the catalytically powered devices are powered by decomposing substrate molecules in solution. A comparison of Marangoni effect and enzyme powered stirrers is made. Marangoni effect driven stirrers rotate up to 600 rpm, 75-100-fold faster than enzyme driven microstirrers, however enzyme powered stirrers show increased longevity. Further to stirring applications, the sensitivity of the motion generation mechanisms to fluid properties allows the rotating devices to also be exploited for sensing applications, for example, acting as motion sensors for water pollution

    Effect of nanostructuration on compressibility of cubic BN

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    Compressibility of high-purity nanostructured cBN has been studied under quasi-hydrostatic conditions at 300 K up to 35 GPa using diamond anvil cell and angle-dispersive synchrotron X-ray powder diffraction. A data fit to the Vinet equation of state yields the values of the bulk modulus B0 of 375(4) GPa with its first pressure derivative B0' of 2.3(3). The nanometer grain size (\sim20 nm) results in decrease of the bulk modulus by ~9%

    Electron Anomalous Magnetic Moment in Basis Light-Front Quantization Approach

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    We apply the Basis Light-Front Quantization (BLFQ) approach to the Hamiltonian field theory of Quantum Electrodynamics (QED) in free space. We solve for the mass eigenstates corresponding to an electron interacting with a single photon in light-front gauge. Based on the resulting non-perturbative ground state light-front amplitude we evaluate the electron anomalous magnetic moment. The numerical results from extrapolating to the infinite basis limit reproduce the perturbative Schwinger result with relative deviation less than 0.6%. We report significant improvements over previous works including the development of analytic methods for evaluating the vertex matrix elements of QED.Comment: 6 pages, 1 figure, proceeding for Lightcone 2011 conferenc

    A High-gain and Low-scattering Waveguide Slot Antenna of Artificial Magnetic Conductor Octagonal Ring Arrangement

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    A novel design of high-gain and low-scattering waveguide slot antenna is proposed in this paper. Firstly the scattering pattern of artificial magnetic conductor (AMC) composite surface is estimated by array factor analysis method. The comparison between octagonal ring arrangement and chessboard arrangement proves that the former arrangement has the characteristic of diffuseness-like and expands the bandwidth of radar cross section (RCS) reduction. Secondly, the metal surface of waveguide slot antenna (WSA) is replaced by the octagonal ring arrangement composite surface (ORACS). The gain is improved because of spurious radiation units which are around the slot. At the same time using the phase cancellation principle, a backscatter null achieves RCS reduction in the vertical direction. Experimental results show that the novel antenna after loading with the ORACS, the gain is improved by 5dB; the bandwidth of RCS reduction (reduction greater than 10dB) is 5.24-5.92 GHz

    High value information in engineering organizations

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    The management of information in engineering organizations is facing a particular challenge in the ever-increasing volume of information. It has been recognized that an effective methodology is required to evaluate information in order to avoid information overload and to retain the right information for reuse. By using, as a starting point, a number of the current tools and techniques which attempt to obtain ‘the value’ of information, it is proposed that an assessment or filter mechanism for information is needed to be developed. This paper addresses this issue firstly by briefly reviewing the information overload problem, the definition of value, and related research work on the value of information in various areas. Then a “characteristic” based framework of information evaluation is introduced using the key characteristics identified from related work as an example. A Bayesian Network diagram method is introduced to the framework to build the linkage between the characteristics and information value in order to quantitatively calculate the quality and value of information. The training and verification process for the model is then described using 60 real engineering documents as a sample. The model gives a reasonable accurate result and the differences between the model calculation and training judgments are summarized as the potential causes are discussed. Finally several further the issues including the challenge of the framework and the implementations of this evaluation assessment method are raised

    Information evaluation: empirical investigations in engineering organisations

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    The management of information in engineering organizations is facing a particular challenge due to the ever-increasing volume of information needs to be dealt with. It has been recognized that an effective methodology is required to evaluate information in order to avoid information overload and to retain the right information for reuse. By whatever approaches, information evaluation judgments are made in those engineering organizations in order to support businesses decisions. Investigating those practical methodologies would benefit the overall information evaluation research. This paper addresses this practical information evaluation issue firstly by briefly reviewing the idea of information evaluation, the definition of value, and related research work on the value of information in various areas. Then a series of industrial empirical investigation activities, based on interviews in engineering organizations, are introduced. The evaluation approaches in those organizations are analyzed and compared according to the nature of each of the organizations. The current practices are then summarized. Finally, several further issues including the impact of the newly developed information evaluation methodologies and the implementation issues associated with this evaluation assessment method are raised

    Defining a framework for the evaluation of information

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    In any enterprise, principled decisions need be made during the entire life cycle of information about its acquisition, storage, creation, maintenance and disposal. Such information management requires some form of information evaluation to take place, yet little is understood about the process of information evaluation within enterprises. For evaluation support to be both effective and resource efficient, particularly where decisions are being made about the future of large quantities of information, it would be invaluable if some sort of automatic or semi-automatic methods were available for evaluation. Such a method would require an understanding of the diversity of the contexts in which evaluation takes place so that evaluation support can have the necessary context-sensitivity. This paper identifies the dimensions that influence the information evaluation process and defines the elements that characterize these dimensions, thus providing the foundations for a context-sensitive framework for information evaluation
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