Effect of CF/GF fibre hybrid on impact properties of multi-axial warp knitted fabric composite materials

The multi-axial warp knitted fabric (MWK) is a useful reinforcement for composite. Higher mechanical performance resulted from no crimp of the fibre bundle is achieved compared with the general textile composites. For the fibre bundle of MWK, only one type of reinforcement fibre among glass, carbon fibre bundle, and so on has been selected. The mechanical properties and the cost of MWK composite depend on the feature of the fibre bundle. In order to extend the applicability of composite, the concept of “fibre hybrid composite” was applied into the MWK composite. Two kinds of fibre bundle; carbon and glass, were used in the 0/90 multi-axial warp knitted fabric. As the fibre hybrid composite; the inter-layer hybrid composite in which each layer was fabricated by carbon and glass fibre bundle respectively was investigated. Impact properties of composite were investigated by using drop weight impact tests. In case of unsaturated polyester, total energy and progressive energy of inter-layer fibre hybrid composite realized the highest value in all specimens. However, in case of epoxy resin, inter-layer hybrid composite didn’t realize the highest value in all specimens. The difference in energy absorption capability could be described with the fracture mechanism.     

Dispersion slope equaliser using bend-induced positive dispersionslope in coiled pure-silica fibre

The dispersion slope of a dispersion-shifted fibre has been successfully equalised by using a bend-induced positive dispersion slope in a singlemode fibre. We realised the bent fibre dispersion slope equaliser by using a 1.3 μm zero-dispersion pure silica core fibre (PSM). This equaliser provides a dispersion slope of -12.54 ps/nm² /km in the 1.5 μm region     

A biomimetic system for localization and separation of multiplesound sources

This paper presents a system for sound source localization and separation inspired by the auditory mechanisms of biological systems. The system consists of three omni-directional microphones, banks of band-pass filters, and a personal computer with a digital signal processor. Sound sources are localized using arrival temporal disparities. The zero-crossing method is used to quickly detect the arrival temporal disparities at signal onset to cope with echo. Arrival temporal disparity histograms remove ambiguity and improve accuracy. The Histogram Mapping Method is introduced to localize multiple sound sources. The system separates multiple sound sources by obtaining their direction information from the localization process. Localization and separation experiments were conducted in an anechoic chamber and an empty room. Two sound sources, human voices, were used. Directions of the sound sources were localized within a few degrees. Sound sources were separated by 25 dB attenuation     

A Speech Prosthesis Employing a Speech Synthesizer?Vowel Discrimination from Perioral Muscle Activities and Vowel Production

A speech prosthesis has been developed based on the following idea. When a handicapped person such as a laryngectomee tries to speak in vain, the movements of the mouth, tongue, etc., are elicited. By detecting the movements, what he or she is trying to say can be determined. Then a speech synthesizer is driven to produce a voice of good quality.     

Induction of the 2B9 antigen/dipeptidyl peptidase IV/CD26 on human natural killer cells by IL-2, IL-12 or IL-15

Activation of human natural killer (NK) cells involves sequential events including cytokine production and induction of cell surface molecules, resulting in the enhancement of cytolytic activity. To delineate the activation process of NK cells, we generated murine monoclonal antibodies (mAbs) against YT, a human large granular lymphocyte/natural killer (LGL/NK) cell line. Among the mAbs reactive with YT cells, one mAb, termed 2B9, was noted because of the lack of reactivity with most of the human T- and B-cell lines tested. In fresh peripheral blood mononuclear cells (PBMC), however, the majority of cells expressing this antigen (Ag) were T cells but not CD16+ nor CD56+ NK cells. Since YT cells showed an activated phenotype expressing interleukin-2 (IL-2) receptor alpha chain, we examined whether 2B9 Ag could be induced on normal human peripheral blood NK cells by cytokines known to activate NK cells. The 2B9 Ag was induced on NK cells by IL-2, IL-12 or IL-15 while no induction was observed by interferon-gamma (IFN-gamma). Biochemical analysis showed that anti-2B9 mAb recognized a 115 kDa molecule in YT cells. A cDNA clone encoding the 2B9 Ag was isolated from a cDNA expression library of YT cells and its sequence was identical to CD26 cDNA although it was not of full length. Transient expression of the 2B9 cDNA on COS-7 cells revealed that this cDNA encodes the antigenic epitope(s) recognized by anti-2B9 mAb as well as Ta1, an anti-CD26 mAb. These results showed that the 2B9 Ag is identical to CD26, and demonstrated that CD26 is an activation antigen on CD16+ CD56+ NK cells inducible by IL-2, IL-12 or IL-15.     

A concurrent test architecture for massively parallel computers andits error detection capability

Presents new principles for online monitoring in the context of multiprocessors (especially massively parallel processors) and then focuses on the effect of the aliasing probability on the error detection process. In the proposed test architecture, concurrent testing (or online monitoring) at the system level is accomplished by enforcing the run-time testing of the data and control dependences of the algorithm currently being executed on the parallel computer. In order to help in this process, each message contains both source and destination addresses. At each message source, the sequence of destination addresses of the outgoing messages is compressed on a block basis. At the same time, at each destination, the sequence of source addresses of all incoming messages is compressed, also on a block basis. Concurrent compression of the instructions executed by the PEs is also possible. As a result of this procedure, an image of the data dependences and of the control flow of the currently running algorithm is created. This image is compared, at the end of each computational block, with a reference image created at compilation time. The main results of this work are in proposing new principles for the online system-level testing of multiprocessor systems, based on signaturing and monitoring the data dependences together with the control dependences, and in providing an analytical model and analysis for the address compression process used for monitoring the data routing process     

Dynamic properties of 1.3 μm semi-insulating-BHlight-emission-and-detection (LEAD)-diode module for subscriber TCMtransmission systems

The dynamic properties of a 1.3 μm light-emission-and-detection (LEAD)-diode module that has a high mesa semi-insulating buried heterostructure (SI-BH) to reduce the capacitance of the chip (0.6-0.8 pF) are described. A modulation bandwidth of 12 GHz in laser diode (LD) operation, and detection bandwidth of ~1.9 GHz in photodetector (PD) operation are achieved using a chip and a module, respectively. In bit error rate (BER) performance at 30 Mbit/s, a receiver sensitivity (BER=10^-8) of -37.4 dBm is confirmed, and a switching time of under 1 μs from LD to PD operation is estimated using a circuit simulator     

Picosecond optical pulse compression from gain-switched 1.3 ?m distributed-feedback laser diode through highly dispersive single-mode fibre

The first demonstration to compress the linearly chirped optical pulses from a gain-switched distributed-feedback laser diode (DFB-LD) is described at 1.3 ?m wavelength. By travelling through a highly dispersive single-mode fibre with 48 ps/nm normal dispersion, a 26 ps (FWHM) pulse having red-shift frequency chirping of 85 GHz (FWHM) is compressed to 8.3 ps with the time-bandwidth product of 0.71.     

Introduction of amino groups into the interlayer space of graphite oxide using 3-aminopropylethoxysilanes

Graphite oxide was silylated by 3-aminopropylethoxysilanes under various reaction conditions. Two types of layered materials were obtained when 3-aminopropyltriethoxysilane was reacted with graphite oxide. One obtained at lower temperatures was 3-aminopropyltriethoxysilane-intercalated graphite oxide with an interlayer spacing of 1.27 nm, in which amino groups of 3-aminopropyltriethoxysilane were bonded to hydroxyl groups of graphite oxide. At higher temperatures, silylation of graphite oxide occurred, giving a phase with larger interlayer spacing of 1.37 nm. Chemical reduction of graphite oxide to disordered carbon by amino groups occurred at the same time. Similar reactions occurred when 3-aminopropyldiethoxymethylsilane and 3-aminopropylethoxydimethylsilane were reacted and they were introduced into the interlayer space of graphite oxide. Large amounts of silicon, and accordingly amino groups, were introduced in graphite oxide when it was silylated by 3-aminopropyldiethoxymethylsilane because its reactivity for chemical reduction of graphite oxide was relatively lower than that of 3-aminopropyltriethoxysilane and additional silylation was possible. The amount of amino groups available for chemical adsorption of formaldehyde reached a very high value of 3.8 mmol/g for graphite oxide silylated by 3-aminopropyldiethoxymethylsilane.