Preparation of siloxane-like films by glow discharge polymerization

Glow discharge polymerizations of tetramethoxysilane (TMOS), tetramethylsilane/oxygen mixture (½ molar ratio) (TMS/O₂), hexamethyldisiloxane (HMDSO), and tetramethyldisiloxane (TMDSO) were carried out for the preparation of thin, polymeric films with siloxane structures. The chemical composition of the formed polymers was examined by elemental analysis, infrared spectroscopy, and electron spectroscopy for chemical analysis (ESCA) in connection with polymerization conditions, especially, a level of the radiofrequency (rf) input power per mass of the monomers (W/FM value). The polymers prepared from HMDSO at fairly low W/FM values resembled in chemical composition the conventionally polymerized polydimethylsiloxane. The surface properties of the formed polymers also were evaluated by the measurement of surface energy.     

Novel CO2 Absorbents Using Lithium-Containing Oxide

We have discovered a series of lithium-containing oxides that immediately react with ambient carbon dioxide (CO₂) up to 700°C. The products react and return reversibly to the oxides at a temperatures higher than about 700°C. The absorption capacity surpasses that of other CO₂ absorbents by a factor of 10. Utilizing these absorbents, the possibility of a CO₂ separation system that operates at around 500°C is proposed. It is generally believed that a CO₂ separation process operable at temperatures higher than 500°C has the special benefit of a small energy penalty. Moreover, the absorption also proceeds at ambient temperature in the atmospheric environment. This property offers the possibility of many other applications, such as air cleaners or cartridges. Therefore, we think these materials have the potential to make a valuable contribution to the realization of CO₂ emission control.     

Proposal of variable sequential sampling plan having desired operating characteristics indexed by quality loss

The proportion of non-conforming items has been traditionally utilised as an evaluation criterion for quality of items. However, the proportion of non-conforming items is not necessarily useful as a proper evaluation criterion for controlling high-quality manufacturing in recent years. Accordingly, in order to achieve further quality improvement and innovation, more careful quality evaluation has been required newly. Then, a concept of quality loss in the Taguchi methods has been devised as a severe criterion of quality evaluation. Hereby, a variable single sampling plan having desired operating characteristics (OCs) indexed by quality loss has been proposed in the area of statistical quality control. By the way, the most economical sampling inspection in the average sample number (ASN) is the sequential sampling plan based on the Wald’s sequential probability ratio test. Then, from the viewpoint of cost reduction, we discuss a variable sequential sampling plan having desired OC indexed by quality loss with the aim of expansion of the utility of variable sampling plan for quality loss. As the result, the design procedure of the sequential sampling plan for satisfying some required design conditions indexed by quality loss is provided. In addition, the effectiveness of the proposed sequential sampling plan is verified through some numerical examples.     

Minimizing False Positives of a Decision Tree Classifier for Intrusion Detection on the Internet

Machine learning or data mining technologies are often used in network intrusion detection systems. An intrusion detection system based on machine learning utilizes a classifier to infer the current state from the observed traffic attributes. The problem with learning-based intrusion detection is that it leads to false positives and so incurs unnecessary additional operation costs. This paper investigates a method to decrease the false positives generated by an intrusion detection system that employs a decision tree as its classifier. The paper first points out that the information-gain criterion used in previous studies to select the attributes in the tree-constructing algorithm is not effective in achieving low false positive rates. Instead of the information-gain criterion, this paper proposes a new function that evaluates the goodness of an attribute by considering the significance of error types. The proposed function can successfully choose an attribute that suppresses false positives from the given attribute set and the effectiveness of using it is confirmed experimentally. This paper also examines the more trivial leaf rewriting approach to benchmark the proposed method. The comparison shows that the proposed attribute evaluation function yields better solutions than the leaf rewriting approach.

Socializing artifacts as a half mirror of the mind

In the near future, our life will normally be surrounded with fairly complicated artifacts, enabled by the autonomous robot and brain–machine interface technologies. In this paper, we argue that what we call the responsibility flaw problem and the inappropriate use problem need to be overcome in order for us to benefit from complicated artifacts. In order to solve these problems, we propose an approach to endowing artifacts with an ability of socially communicating with other agents based on the artifact-as-a-half-mirror metaphor. The idea is to have future artifacts behave according to the hybrid intention composed of the owner’s intention and the social rules. We outline the approach and discuss its feasibility together with preliminary work.

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Dielectric Dispersion of Polycrystalline Aluminum Nitride at Microwave Frequencies

Complex permittivity of polycrystalline AlN was measured over the frequency range 100 MHz to 13 GHz using reflection coefficient and cavity resonator methods. Dielectric relaxation peaks of loss tangent were observed in the frequency range 200 MHz to 3 GHz. The maximum value of loss tangent was ∼200 × 10⁻⁴. Relative permittivities decreased by ∼4% with increased frequency at the region of relaxation peaks. It was shown that these dispersion frequencies were inversely proportional to the grain sizes of AlN and independent of purities and processes. Model calculations for elastic vibration of a single-crystal grain of AlN were performed to investigate the origin of the dielectric dispersion due to piezoelectric effect. The calculated results of elastic sphere and 14-faced-polyhedron models showed a good quantitative agreement with the observed dispersion frequencies, which suggested that the dispersion was due to a piezoelectric vibration of a single grain of AlN ceramics at microwave frequencies.     

Synthesis of zirconia sphere particles based on gelation of sodium alginate

Zirconia sphere particles were synthesized through the gelation process of Na-alginate, and cermet (ZrO₂-Mo) pellets were fabricated under several conditions. In this process, a zirconia slurry was prepared by mixing oxide powders (ZrO₂, Y₂O₃, Er₂O₃, CeO₂), distilled water and Na-alginate, and subsequently dropped into CaCl₂ solution. As a result, zirconia sphere particles coated with a gelled film were synthesized. The slurry density (zirconia content in slurry) of 30-64 wt.% and Na-alginate concentration of a few% were good for gelation for up to 10 wt.% CaCl₂ solution. Sphere particles with smaller diameter were obtained by dropping slurry with a mechanical vibration. The prolongation of the ball milling time for mixture of oxide powders was effective to increase the sintered density of zirconia sphere particles, especially for higher CeO₂ concentration. The dense cermet pellets were fabricated for max. 50% volume ratio of zirconia phase for Mo matrix using zirconia particles covered with Mo powder by a rotating granulation method.     

Fe-Ni-Si基奥氏体时效合金的马氏体相变和形状记忆效应

It is well known that the morphologies of the α martensite formed from the γ phase in ferrous alloys are classified into five types of lath, butterfly, (225)A type plate,lenticular and thin-plate. Among those α martensites, onlythe thinplate martensite, which is characterized by containing a high density of transformation twins, has a potential of exhibiting a perfect shape memory (SM) effect.Recently the present authors found in Fe-Ni-Si alloys that the thin-plate martensite is formed by the introduction of fine and coherent γ-(Ni,Fe)3Si particles with a L12 ordered structure in the austenite matrix due to ausaging. In the present study, the SM properties of the ausaged Fe-Ni-Si alloys with the thin-plate martensite are investigated by a conventional bending-test. The effects of the addition of Co to the Fe-Ni-Si alloys on the martensitic transformation and the SM properties are also investigated. It is shown that while the ausaged Fe-Ni-Si ternary alloys exhibit an imperfect SM effect due to reverse transformation from stress-induced thin-plate martensite to austenite, the SM properties are improved by the addition of Co. An almost perfect SM effect is confirmed in the Fe-Ni-Si-Co alloys by heating to 1 100 ℃ after deformation at -196 ℃.     

Phosphorylation-dependent control of structures of intermediate filaments: a novel approach using site- and phosphorylation state-specific antibodies

The synovitis of rheumatoid arthritis (RA) is one of few pathological lesions in which B lymphocyte accumulation progresses to the extent of germinal centre formation. The present study was designed to assess the ability of synovial fibroblasts to express molecules implicated in B lymphocyte survival and differentiation, both in vivo, and in response to cytokines in vitro. Normal and diseased synovia were examined by indirect immunofluorescence. In all tissues synovial intimal fibroblasts showed co-expression of vascular cell adhesion molecule-1 (VCAM-1) and complement decay-accelerating factor (DAF) comparable to that of follicular dendritic cells (FDC), but not complement receptor 2 (CR2). In rheumatoid synovia, subintimal cells showed variable expression of VCAM-1 and DAF, with bright co-expression of VCAM-1, DAF and CR2 in lymphoid follicle centres. B lymphocytes, some of which were proliferating cell nuclear antigen-positive, were present in contact with subintimal cells expressing VCAM-1 with or without DAF or CR2. B lymphocytes were rarely present in the intimal layer, and, where present, showed fragmentation. In vitro, synovial fibroblasts exposed to tumour necrosis factor-alpha (TNF-alpha) in combination with interferon-gamma (IFN-gamma) showed enhanced expression of VCAM-1, in comparison with fibroblasts from skin and lung and, unlike skin and lung fibroblasts, also expressed DAF and CR2. These findings support the hypothesis that synovial targeting in RA involves an enhanced ability of synovial fibroblasts to support B lymphocyte survival. This appears to be dependent, not on the constitutive expression of VCAM-1 and DAF on intimal cells, but on the increased ability of subintimal cells to respond to proinflammatory cytokines, perhaps critically in the expression of VCAM-1.