Changes in contributions of matrix and block boundary strengths to macroscopic hardness of high Cr ferritic steel during creep

The instrumented indentation test was applied to the interrupted creep specimens of turbine rotor steel (Fe-10Cr-1Mo-1W-VNbN) to investigate the changes in contributions of matrix and block boundary strengths to macroscopic hardness during creep. The indentation tests were performed under the loads of 1 and 10 mN to determine the matrix strength and the block boundary strength, respectively. The matrix strength of the grip portion decreased gradually with increasing life fraction and, for the gauge portion, the decrease was more pronounced, particularly, at the latter half of the life. On the other hand, the experimental results revealed that the block boundary strength decreased significantly at the early stage of the creep life, but this decrease was no longer pronounced when the creep life fraction exceeded 20%. Additionally, there was a good correlation between the block boundary strength and the width of block boundary carbide and the carbide coarsening was considered to be closely associated with the decrease in block boundary strength.     

An Assay Method for Determining the Total Lipid Content of Fish Meat Using a 2-Thiobarbituric Acid Reaction

A method for the determination of the total lipid content in fish meat was established using a 2-thiobarbituric acid (TBA) reaction, which had previously been used for the determination of lipid peroxides in animal tissues. In this method, an unspecific peroxidation of fish oils was created by omitting the addition of antioxidant to the reaction mixture during the TBA reaction, because fish meat is more sensitive to the TBA reaction due to its higher concentration of polyunsaturated fatty acids, especially docosahexaenoic acid and eicosapentaenoic acid, which can easily react artificially with TBA in the absence of an antioxidant in the assay system. As for a practical application of this method, we tried to optimize the assay procedures in the sampling, reaction, and detection steps of this method, and finally proposed a new standard procedure recommended for determining the total lipid content of fish using a TBA reaction. In order to confirm the accuracy of the new procedure, comparative evaluations for the lipid contents of commercially available fish, i.e., chub mackerel (Scomber japonicus) and saury (Cololabis saira) were made between the conventional procedure and the recommended TBA method. The lipid contents obtained by the two methods coincided well with high correlation. This method is relevant for total lipid content analysis of fish meat under restricted laboratory conditions.     

The detailed analysis of the vinylidene structure of metallocene-catalyzed polypropylene

The vinylidene structures in polypropylenes produced by ethylenebis(indenyl)zirconiumdichloride (En(Ind)₂ZrCl₂), 1, and isopropyl(cyclopentadienyl)(fluorenyl)zirconiumdichloride (iPr(Cp)(Flu)ZrCl₂), 2, were analyzed by ¹H NMR. The vinylidene group adjacent to the chain end was clearly distinguished from other internal vinylidene structures for the first time using 1,2-dichlorobenzene as solvent. The polypropylene produced by 2 had much internal vinylidene groups compared with one by 1.     

Optimum condition of Fourier transform infrared multiple-angle incidence resolution spectrometry for surface analysis

A novel measurement technique of pure out-of-plane vibrational modes of thin films on a nonmetallic substrate has recently been proposed, which is named multiple-angle incidence resolution spectrometry (MAIRS). Since this technique could not be replaced by other conventional techniques, MAIRS was expected to be a promising tool for analysis of thin soft materials and surface adsorbates. Nevertheless, some experimental conditions have been found to be inappropriate for MAIRS, which yields incorrect results. In the present study, therefore, the problems in the technique have been investigated in terms of optics to improve the accomplishments of MAIRS. The problems have been found to have a strong relationship with optics in FT-IR, which is influenced by refractive index of the sample material and angle of incidence. In particular, optimization of the size matching of the detector surface and the infrared spot at the detector was a key to having MAIRS perform properly. It has been concluded that reliable MAIRS measurements require overfilling of the detector and a substrate with a high-refractive index.     

Solo instrumental music analysis using the source-filter model as a sound production model considering temporal dynamics

A source-filter model, originally devised to represent a sound production process, has been widely used to estimate both of the source signal which includes pitch information and the synthesis filter which includes vowel information, as from sounds of a speech signal. We use this model to identify instruments by their instrumental sound signal. However, this model suffers from an indeterminacy problem. To resolve it, we employ three elements of the sound: loudness, pitch and timbre. Our assumption is that the source signal is represented by time-varying pitch and amplitude, and the synthesis filter by time-invariant line spectral frequency parameters. We construct a probabilistic model that represents our assumption with an extension of the source-filter model. For learning of model parameters, we employed an EM-like minimization algorithm of a cost function called the free energy. Reconstruction of the spectrum with the estimated source signal and synthesis filter, and instrument identification by using the model parameters of the estimated synthesis filter are performed to evaluate our approach, showing that this learning scheme could achieve simultaneous estimation of the source signal and the synthesis filter.

Yet another generation of LALR parsers for regular right part grammars

In this paper we introduce two methods for building LALR parsers for regular right part grammars (RRPGs). Both methods build a parser directly from a grammar, require no extra state or data structure, and can deal with all LALR RRPGs. The first method is quite simple. For almost all LALR RRPGs, including the majority of grammars with stacking conflicts, parsing actions are similar to those of LALR parsers for usual context free grammars. No extra action is required to recognize a handle in this case. For other LALR RRPGs, the right hand side of a production is checked to recognize a handle. The second method does not require checking of the right hand side of a production to recognize a handle. Instead, it records the number of conflicts in LR items and in the stack. Unlike previous methods, our method needs no extra data structure. Received: 23 September 1998 / 16 March 2001     

Special-purpose computer for two-dimensional FFT

Using a system of combined PC and LSI is useful when a research environment does not allow using supercomputers and calculation objects are restricted. FPGA is different from ASIC. A circuit in FPGA can be designed and reconfigured with PC or workstation electrically. We designed and implemented a circuit for 8×8 two-dimensional 2-radix FFT in a FPGA and compared its calculation speed with that of a PC. As a result, the calculation speed of the FPGA was found to be 1.3 times faster than that of a PC.     

Durable, Ultraluminous Structure for Incandescent, High-Power White-LED

A new particle- and resin-free system composed of transparent, binary single crystals entangled with each other continuously has been successfully developed for a light source for illumination. These single crystals exist in a semi-coherent state like a block copolymer; one of these single crystals exhibits effective photoluminescence and the other plays an important role as a light guide of excitation and emitting lights. This material can have low backscattering and high quantum efficiency, resulting in twice the emission light of conventional particle-dispersed systems. Furthermore, this system shows outstanding durability, because of its thermostructural properties. This concept will be expanded into wide combinations to create incandescent systems in the future.     

Development of biomaterial using durable surface wettability fabricated by plasma-assisted immobilization of hydrophilic polymer

As a series of plasma-assisted immobilization of bio-molecule for bio application, 12-mer oligo-DNA was immobilized on the surface of LDPE-VEMAC sheet, which was prepared by plasma-assisted method and possessed a lot of carboxyl groups on the surface. A larger amount of oligo-DNA could be immobilized by the present technique compared with other methods reported. The sheet immobilizing oligo-DNA detected the complementary oligo-DNA and was reusable for several times at least under present experimental condition. This method would be useful for the fabrication of the analytical instrument such as DNA chip, protein chip and affinity chromatography.