VUV single-photon ionization ion trap time-of-flight mass spectrometer for on-line, real-time monitoring of chlorinated organic compounds in waste incineration flue gas

In this work, a sensitive and robust vacuum ultra-violet (VUV) single-photon ionization (SPI) ion trap time-of-flight mass spectrometer (VUV-SPI-IT-TOFMS) for on-line, realtime monitoring of chlorinated organic compounds in waste incineration flue gas has been newly developed. The fragment-free SPI technique with 121.6-nm VUV lamp irradiated by a microwave generator and the quadrupole ion trap to accumulate and select analyte ions were combined with a reflectron time-of-flight mass spectrometer to detect chlorinated organic compounds at trace level. This measuring system was tuned up to detect dioxins precursors with the aim at an application to monitoring trace level toxic substances in flue gases from incinerator furnaces. As a result, this technology has made it possible to analyze trichlorobenzene (T3CB), a dioxin precursor, in 18 s with a sensitivity of 80 ng/m3-N (10 pptv) using the selective accumulation of analyte substances and separation of interfering substances in the ion trap. Moreover, the first field test of the continuous monitoring T3CB in an actual waste incineration flue gas had been done for 7 months. The results show that this system has an exceeding robust performance and is able to maintain the high sensitivity in analyzing T3CB for long months of operation.     

Effects of gas adsorption on the electrical conductivity of single-wall carbon nanohorns

We present significant electrical conductivity responses of the pelletized as-prepared and oxidized (ox-) single-wall carbon nanohorns (SWNHs) on adsorption of CO(2) and O(2). The morphological and pore structures of both pelletized SWNHs were examined by transmission electron microscopy (TEM) and nitrogen adsorption isotherm, leading to explicit evidences of the formation of nanoscale windows on the wall by oxidation. The SWNH and ox-SWNH induced a semiconducting behavior, strongly responded to CO(2) and O(2) adsorptions, and each exhibited n-type- and p-type-like conductivities. The electrical conductivity increase and decrease for CO(2) and O(2) adsorption, respectively, were observed for SWNH, whereas ox-SWNH showed a marked electrical conductivity drop on CO(2) adsorption and almost no change on O(2) adsorption. The dramatically different electrical conductivity response of ox-SWNH is presumed to be ascribed to the annihilation of pentagons in the single graphene wall by oxidation.     

Contouring controller design for biaxial feed drive systems considering compliance of transmission mechanism

Contouring control is an effective method for computer numerical controlled machining, and various such designs have been proposed to date. However, the compliance of the transmission mechanism is not considered in most existent contouring controller designs. This paper presents a new contouring control system design considering the compliance of a transmission mechanism based on a fourth-order model of feed drive dynamics. First, we present a controller design that enables the controller gain assignment for reducing the error component orthogonal to the desired contour curve, independent of the tangential error component. Although this design provides better control performance with small control input variance, there exists an inherent contour error because of the difficulty in calculating the exact contour error for any contour curve in real time. To address this problem, a reference adjustment method is used to estimate the actual contour error. The effectiveness of the proposed design is experimentally verified by comparing the control performance with a design based on a plant model that neglects the compliance.     

A lithium superionic conductor

Batteries are a key technology in modern society. They are used to power electric and hybrid electric vehicles and to store wind and solar energy in smart grids. Electrochemical devices with high energy and power densities can currently be powered only by batteries with organic liquid electrolytes. However, such batteries require relatively stringent safety precautions, making large-scale systems very complicated and expensive. The application of solid electrolytes is currently limited because they attain practically useful conductivities (10(-2) S cm(-1)) only at 50-80 °C, which is one order of magnitude lower than those of organic liquid electrolytes. Here, we report a lithium superionic conductor, Li(10)GeP(2)S(12) that has a new three-dimensional framework structure. It exhibits an extremely high lithium ionic conductivity of 12 mS cm(-1) at room temperature. This represents the highest conductivity achieved in a solid electrolyte, exceeding even those of liquid organic electrolytes. This new solid-state battery electrolyte has many advantages in terms of device fabrication (facile shaping, patterning and integration), stability (non-volatile), safety (non-explosive) and excellent electrochemical properties (high conductivity and wide potential window).     

Autonomous dispersed control system for independent micro grid

In this paper, we show an autonomous dispersed control system for independent micro grid of which performance has been substantiated in China by Shikoku Electric Power Co. and its subsidiary companies under the trust of NEDO (New Energy and Industrial Technology Development Organization). For the control of grid interconnected generators, the exclusive information line is very important to save fuel cost and maintain high frequency quality of the electric power supply, but it is relatively expensive in such small micro grids. We contrived an autonomous dispersed control system without any exclusive information line for dispatching control and adjusting supply control. We have confirmed through the substantiation project in China that this autonomous dispersed control system for an independent micro grid has a very satisfactory characteristic from the viewpoint of less fuel consumption and high electric quality. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 28–35, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20618     

Control methods and compensation characteristics of a series active filter for neutral conductor

With an increase in the number of electronic devices, such as personal computers, connected to power distribution lines in commercial buildings, problems associated with their use, such as voltage distortion on utility outlets and excessive neutral current on the distribution lines, become more and more serious. This paper shows control methods and compensation characteristics of series active filters connected to the neutral conductor. The distinctive functions of the proposed active filter are the mitigation of third harmonic voltage and the reduction of neutral current in three‐phase four‐wire distribution systems. The required kVA rating of the proposed active filter is less than 10% of that of the harmonic producing leads. A control method of the DC capacitor voltage on the active filter circuit is also described. It was experimentally demonstrated that one of these two functions of the active filter (to mitigate harmonics or to reduce the neutral current) can be realized selectively and that the DC capacitor voltage of the active filter can be regulated to a desired value. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 53–63, 2006; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20227     

Measurement of odour after in vitro or in vivo ingestion of raw or heated garlic, using electronic nose, gas chromatography and sensory analysis

The possibility of characterising the garlic odour in in vitro and in vivo was demonstrated using the newly developed electronic nose, based on an array of metal oxide semiconductor sensors. Two grams of raw and heat‐treated garlic, and breath odour after eating 2 g of raw garlic and heat‐treated garlic were analysed with an electronic nose. Furthermore, calculation of F‐value (odour quality) and S‐value (odour strength) demonstrated distinct odour differences between the samples, and that the electronic nose could differentiate between the various garlic associated odours corresponding to the different origins (in vivo or in vitro), or to the different processing (raw or heat‐treated). The correlation between gas chromatography and sensory analysis was also discussed in order to identify the volatile compounds in the sample, and to investigate the association with the response of human perception to the samples. Results showed that odour sensor data were easier to obtain and were well correlated with both types of instrument.     

Efficient cleavage of RNA at high temperatures by a thermostable DNA-linked ribonuclease H

To construct a DNA-linked RNase H, which cleaves RNA site-specificallyat high temperatures, the 15-mer DNA, which is complementaryto the polypurine-tract sequence of human immunodeficiency virus-1RNA (PPT-RNA), was cross-linked to the unique thiol group ofCys135 in the Thermus thermophilus RNase HI variant. The resultantDNA-linked enzyme (d15-C135/TRNH), as well as the d15-C135/ERNH,in which the RNase H portion of the d15-C135/TRNH is replacedby the Escherichia coli RNase HI variant, cleaved the 15-merPPT-RNA site-specifically. The mixture of the unmodified enzymeand the unlinked 15-mer DNA also cleaved the PPT-RNA but ina less strict manner. In addition, this mixture cleaved thePPT-RNA much less effectively than the DNA-linked enzyme. Theseresults indicate that the cross-linking limits but acceleratesthe interaction between the enzyme and the DNA/RNA substrate.The d15-C135/TRNH cleaved the PPT-RNA more effectively thanthe d15-C135/ERNH at temperatures higher than 50°C. Thed15-C135/TRNH showed the highest activity at 65°C, at whichthe d15-C135/ERNH showed little activity. Such a thermostableDNA-linked RNase H may be useful to cleave RNA molecules withhighly ordered structures in a sequence-specific manner.     

Microstructure of Partially Melted Filamentary Hg1223 Superconductors

A microstructure of filamentary Hg1223 superconductor by using CaHgO ₂ for a vaporizing material was studied to improve the grain alignment and the transport J _c . A. filamentary precursor Ba ₂ Ca ₂ Cu ₃ Re _0.2 O _x was fabricated using a solution spinning method and partially melted in an evacuated quartz tube with a pellet of (CaHgO ₂ )Ba ₂ CaCu _2.8 Re _0.2 (CuF ₂ ) _0.2 O _x . The reacted sample was a single phase of Hg1223 with T _c value of 135 K. Platelike grains were partly aligned along the fiber length by controlling the heating condition. The J _c value of the sample enhanced by using CaHgO ₂ in stead of HgO for the vaporizing material. Although the J _c value rapidly decreased by applying the field less than 0.1 T, the superconductivity at 77 K of the sample maintained in the field up to 8T.     

Synthesis and characterization of mesoporous carbon nano-dendrites with graphitic ultra-thin walls and their application to supercapacitor electrodes

Mesoporous carbon nano-dendrites (MCNDs) with ultra-thin graphitic walls are synthesized by controlling the highly exothermic segregation reaction of silver acetylide into a carbon skeleton and silver vapor. The dendroid acetylides were quickly warmed to 150 °C emitting a brilliant flash of reddish orange light with a thunderous sound indicative of the sudden jump of the local temperature to higher than 2000 °C. This sudden heating boils off the silver from the main body, leaving carbon skeletons, the MCNDs. Raman spectra clearly indicate that the skeletons consist of mainly single-layer graphene walls. SEM and TEM images as well as EELS spectra show that the main bodies with ∼50 nm radii branches every 100-150 nm and is composed of cells with graphene walls. The MCNDs showed a BET surface area of 1610 m²/g. Cyclic voltammetry of a supercapacitor with MCND electrodes showed good rectangular curves, even at a scanning rate of 400 mV/s and a peak current density higher than 40 A/g, suggesting applicability for high current and high-speed charge-discharge capacitors for motor vehicles. These properties are attributed to the dendroid branching structure of the main body that allows fast and massive ion transport through the open channels between branches.