Deformation behavior and mechanical properties of braided rectangular pipes

The purpose of this study is to clarify the deformation behavior and the relationship between the braiding angle and mechanical properties for the braided rectangular pipe. Three-point bending test was performed for each specimen. Furthermore, the effect of the solid-core bar on the deformation state of the rectangular pipe was studied by finite element method (FEM). Moreover, the effect of the braiding angle on the deformation behavior in detail was investigated. The bending modulus and the bending strength for each specimen were decreased with an increase in the braiding angle. The local deformations occurred at the compression side under loading nose and decreased with an increase in stiffness properties in circumferential direction. From FEM analysis, using the aluminum solid-core bar was effective to restrain the local deformation. The difference between the bending moduli of experiments and FEM was decreased with an increase in the modulus in transverse direction.     

New multivariate strategy for panel evaluation using principal component similarity

Advantages of principal component similarity (PCS) as an unsupervised classification techniques compared to supervised methods are the detectability of outliers or anomalies, a capacity to classify continuum, easy identification of causes for grouping, and a potential of discovering new groups. The ability of detecting outliers or anomalies was utilized to eliminate panel members who were not appropriate for the classification purposes by using PCS scattergrams. After eliminating the unqualified panelists, the evaluation score tables were realigned from the one based on panelists to that based on samples. Accumulated principal component score were computed for the samples in a form of SPC_i × S_i, where PC_i was the principal component score of sample i and S_i was its proportion within the total variation. The conventional averaging algorithms of evaluated scores are useful, as this techniques absorbs the effect of unjustifiable negative scores reported by outliers. However, more reasonable summary scores for the samples could be obtained by eliminating unreasonable evaluation scores made by the outliers as well as by using the above new summary values. Differences in deviations of evaluation among attributes, such as those in likenesses of color and taste of meat products, were normalized. Specific training or selecting qualified panelists prior to panel evaluation is unnecessary when the information obtained from panel evaluation is required to reflect the variable broad patterns of consumer preference. Information obtained from consumer preference test based on cluster analysis, which was applied to a beverage, might be more readily recovered by using this new strategy.     

Formation of L10-type ordered β′ phase in as-solutionized dental Ag-Pd-Au-Cu alloys and hardening behavior

The relationship between the microstrucutural changes of L1₀-type ordered β′ phase and hardening behavior in as-solutionized dental Ag-Pd-Au-Cu alloys was investigated by changing the cooling rate and the solution treatment temperature. Additionally, the formation process of the β′ phase in as-solutionized Ag-Pd-Au-Cu alloy was attempted to clarify. The microstructural changes were observed by X-ray diffraction (XRD) method and transmission electron microscopy (TEM). The hardness was evaluated using a Vickers microhardness tester. The β′ phase is precipitated regardless of the cooling rate, after solution treatment at 1123 K. TEM dark field images show that the size of the β′ phase decreases and the number of β′ phase increases with an increase in the cooling rate. The Vickers hardness value increases with an increase in cooling rate. TEM dark field images show that the microstructure of β′ phase is similar when the solution treatment temperature increases from 1123 K to 1173 K. However, the Vickers hardness increases with an increase of solution treatment temperature. It is of great significance to reveal that the β′ phase precipitated in as-solutionized Ag-Pd-Au-Cu alloy is formed during cooling after high-temperature solution treatment and that the growth of the β′ phase is diffusion controlled.     

Stress Corrosion and Corrosion Fatigue Crack Growth of Zr-Based Bulk Metallic Glass in Aqueous Solutions

Crack-propagation tests on a bulk metallic glass (BMG), Zr₅₅Cu₃₀Ni₅Al₁₀, were conducted either in aqueous sodium chloride (NaCl) solutions or in high-purity water under sinusoidal cyclic loading or sustained loading. Although the crack growth rate in high-purity water was almost identical to that in air, the rate in the NaCl solution was much higher than that in air, even in a very low concentration of NaCl such as 0.01 mass pct. In a 3.5 mass pct NaCl solution, the time-based crack growth rate during cyclic loading, da/dt, was determined by the maximum stress-intensity factor, K _max, but was almost independent of the loading frequency and the stress ratio, and the rate was close to that of stress corrosion cracking (SCC) under a sustained loading.     

Temperature dependence of Bi4Ge3O12 photoluminescence spectra

Bi₄Ge₃O₁₂ single crystals were obtained using Czochralski growth method. Photoluminescence spectra were analyzed versus temperature from 12 to 295 K. Besides the previously observed emission bands at 610 and 820 nm, the new emission band at 475 nm was found by a careful temperature dependence measurement in the present study. The influence of basic and defect structure on the shape and position of the spectra versus temperature was discussed.     

Noise rejection method for magnetic noise from wire using ICA for magnetocardiogram

In magnetocardiogram (MCG) measurements, magnetic noise from the wire used to suture the sternum after heart surgery becomes a problem. Independent component analysis is an effective method of noise rejection. In this study, MCG measurements were made on a normal subject with the wire attached and without the wire. We performed signal processing by independent component analysis in order to reduce the effect of magnetic noise from the wire. Comparison of the waveforms after this signal processing with waveforms without the wire clearly showed that magnetic noise caused by the wire was reduced. This result clearly shows that independent component analysis is effective for the removal of magnetic noise from the wire. ©2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 7–14, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20589     

An attempt for coloring multichannel MR imaging data

This is an elementary research into assigning color values to voxels of multi-channel magnetic resonance imaging (MRI) volume data. The MRI volume data sets obtained under different scanning conditions are transformed into components by independent component analysis (ICA), which enhances the physical characteristics of the tissue. The transfer functions for generating color values from the independent components are obtained by using a radial basis function network, a kind of neural net, by training the network with sample data chosen from the Visible Human female data set (VHF). The resultant color volume data sets correspond well with the full-color cross-sections of the Visible Human data sets     

Measurements of biological contaminants and particulate matter inside a dwelling in Japan

To investigate the biological contaminant levels inside dwellings in Japan, the authors measured fungal indices, airborne mite allergens (Der 1 and Der 2), and suspended particulate matter (SPM). Measurements were continuously conducted at one dwelling located in Yokosuka-city, Kanagawa. The biosensors for fungal index were set at 12 points inside and 2 points outside the dwelling. An SPM sampler was placed in the living room, and samplers for collecting allergens were placed in the living room and in the washroom. The peak level of the fungal index was recorded during July, which is the rainy season in Japan. The highest value in the dwelling was 6.9 in the toilet, and the second highest was 6.6 near a window in the living room that faces southeast, and behind the sofa. The highest monthly SPM level was 21.5 micrograms/m3 during October, and the highest monthly allergen level (Der 1) in the living room was 25.7 pg/m3 during November. A positive relationship between the fungal index and mite allergens was not observed, and the levels of contaminants were not as those found in other studies. However, further study to investigate the distribution of biological contaminants is needed because indoor temperature and relative humidity are comparatively high.