Design of FIR linear phase filters with discrete coefficients usingHopfield neural networks

A novel method is presented for designing FIR linear phase filters with discrete coefficients using Hopfield neural networks. The proposed procedure is based on the minimisation of the energy function of the Hopfield neural network, and can produce a good solution to the design of FIR linear phase filters with discrete coefficients     

Effect of the addition of NH4F on anodic behaviors of DSA-type electrodes in H2SO4-(NH4)2SO4 solutions

The effect of NH₄F addition on the high-anodic behaviors of various DSA-type electrodes was investigated in a mixture of sulfuric acid and ammonium sulfate. The pronounced effect of NH₄ addition was observed on DSA-type Ti/RuO₂, Ti/IrO₂?TiO₂ electrodes, but not observed on the other electrodes studied. The close relationship was found between the increment of the electrode potential caused by the NH₄ addition and the quantity of F^? adsorbed on the electrode surface. The effect of NH₄F addition was considered to be resulted from the adsorption of F^? on the electrode surface, and the presence of adsorbed F^? was directly proved.     

The electrocatalytic activities of the Pd-doped MnO2 for the chlorine evolution reaction

The anodic evolution of chlorine on the massive β-MnO₂ doped with various amounts of Pd was investigated in acidic chloride solution. A second-order relation was found between the rate of the chlorine evolution reaction and the number of active Pd sites at the electrode surface. And it was confirmed that, in the relatively low doped electrodes, the active sites are more effectively dispersed on the surface with microscopic homogeneity. From the activation energies, it was also suggested that the reaction mechanism on the MnO₂ doped with relatively small amounts of Pd is somewhat different from that on the pure PdO electrode.     

Small PWRs using coated particle fuel for district heating, PFPWR50

It has been said that nuclear energy is an important option for especially developing countries to satisfy their increasing energy demand. However, it will be difficult to deploy first of a kind nuclear power plant in developing countries because extensive safety demonstration has to be conducted in industrialized countries. On the other hand, it will be essential to present rigid proof of reliable operational experience to develop proper understanding of the safety features of new reactor systems among the people around the demonstration plant sites. One of the ways to solve the issue is to integrate existing technologies supported by a great deal of data and experience into a new reactor design. Based on the consideration, a small-sized district heating reactor system based on the pressurized water reactor (PWR) technologies combined with the fuel concept of high temperature gas cooled reactors (HTGRs) has been studied. The purpose of the combination of these two existing concepts is to take the best advantages of both excellent operational experience of PWRs and the integrity of HTGR fuel, coated particle fuel, against fission products release even at high temperature. We expect that this approach will help create a breakthrough to the current stagnation of nuclear power deployment.     

Lysophosphatidylinositol Induced Morphological Changes and Stress Fiber Formation through the GPR55-RhoA-ROCK Pathway

We previously reported that lysophosphatidylinositol (LPI) functions as an endogenous agonist of GPR55, a novel cannabinoid receptor. However, the physiological roles of LPI-GPR55 have not yet been elucidated in detail. In the present study, we found that LPI induced morphological changes in GPR55-expressing HEK293 cells. LPI induced the cell rounding of GPR55-expressing HEK293 cells but not of empty-vector-transfected cells. LPI also induced the activation of small GTP-binding protein RhoA and increased stress fiber formation in GPR55-expressing HEK293 cells. The inhibition of RhoA and Rho kinase ROCK by the C3 exoenzyme and the ROCK inhibitor reduced LPI-induced cell rounding and stress fiber formation. These results clearly indicated that the LPI-induced morphological changes and the assembly of the cytoskeletons were mediated through the GPR55-RhoA-ROCK pathway.     

Spiral column configuration for protein separation by high-speed countercurrent chromatography

Retention of the stationary phase of aqueous–aqueous polymer phase systems is improved by a spiral column configuration which utilizes the radially acting centrifugal force along the spiral pitch to retain the heavier phase in the outer portion and the lighter phase in the inner portion of the spiral channel. For the separation of proteins which has low mass transfer rates, the system needs further modification of the separation channel to interrupt the laminar flow and enhance mixing of the two phases.     

Usefulness of Permanent Power Fuse in Control Centers with Molded Case Circuit Breakers

The increase in electric power consumption in industry has led to the development of modern distribution systems such as control centers having high kVA ratings and high prospective fault current. In such a situation, the improvement of the system usefulness such as reliability and cost effectiveness is the essential requirement. An index is presented to evaluate the system usefulness using the cost effectiveness for fault protection in a system of given bank kVA. The index is estimated on four different system structures of control centers, including one which utilizes Permanent Power Fuses (PPF). It is presented that the PPF combined with molded case circuit breaker in main circuit effectively improves the cost effectiveness in control centers with high fault current. Operating principles of the PPF and the control center utilizing the PPF are briefly outlined.     

Collapse of micrometer-sized cavitation bubbles near a rigid boundary

The interaction of cavitation bubbles with a rigid boundary and its dependence on the distance between bubble and boundary is investigated experimentally. Individual cavitation bubbles, with a maximum radius of 150?μm, are generated by using pulsed high-intensity focused ultrasound. Observations are made with high-speed photography with framing rates of up to 200?million frames per second and exposure time of 5?ns, and the spatial resolution is in the order of a few micrometers. The significant parameter of this study is the non-dimensional stand-off parameter, γ, defined as the distance between the ultrasound focus and the rigid boundary scaled by the maximum bubble radius. Both the velocity of the liquid jet developed during bubble collapse and the maximum pressure of the shock wave emitted during bubble rebound show a minimum for γ?≈?1 and a constant value for γ?>?3. The maximum jet velocity is slightly smaller than the corresponding values obtained in the case of millimeter-sized bubbles and ranges from 80?m/s (at γ?≈?1) to 130?m/s (for γ?>?3). No jet formation was observed for γ?>?3. The shock wave pressure, measured at a distance of 5?mm from the emission center, ranges from 0.2?MPa (at γ?≈?1) to 0.65?MPa (for γ?>?3). These values are an order of magnitude smaller than those obtained in the case of millimeter-sized bubbles. The shock wave duration is almost independent of γ at a value of about 75?ns. For large γ values (γ?>?3), a large percentage of the bubble energy (up to 60?%) is transformed into the mechanical energy of the shock wave emitted during bubble rebound but, for γ?≈?1, the conversion efficiency decreases to 30?%. Independent of the relative distance between bubble and rigid boundary, the shock pressure decays proportionally to r ^?1 with increasing distance r from the emission center. The results are discussed with respect to cavitation damage and collateral effects in pulsed high-intensity focused ultrasound surgery.     

The role of numerical simulation for the development of an advanced HIFU system

High-intensity focused ultrasound (HIFU) has been used clinically and is under clinical trials to treat various diseases. An advanced HIFU system employs ultrasound techniques for guidance during HIFU treatment instead of magnetic resonance imaging in current HIFU systems. A HIFU beam imaging for monitoring the HIFU beam and a localized motion imaging for treatment validation of tissue are introduced briefly as the real-time ultrasound monitoring techniques. Numerical simulations have a great impact on the development of real-time ultrasound monitoring as well as the improvement of the safety and efficacy of treatment in advanced HIFU systems. A HIFU simulator was developed to reproduce ultrasound propagation through the body in consideration of the elasticity of tissue, and was validated by comparison with in vitro experiments in which the ultrasound emitted from the phased-array transducer propagates through the acrylic plate acting as a bone phantom. As the result, the defocus and distortion of the ultrasound propagating through the acrylic plate in the simulation quantitatively agree with that in the experimental results. Therefore, the HIFU simulator accurately reproduces the ultrasound propagation through the medium whose shape and physical properties are well known. In addition, it is experimentally confirmed that simulation-assisted focus control of the phased-array transducer enables efficient assignment of the focus to the target. Simulation-assisted focus control can contribute to design of transducers and treatment planning.     

Caspase 1-independent IL-1beta release and inflammation induced by the apoptosis inducer Fas ligand

Anchietia salutaris tea is traditionally used in Brazil to treat allergies, suggesting it contains compounds with antagonistic activity on the allergic mediators. We have evaluated extracts and semi-purified fractions of Anchietia salutaris as a source of compounds having this type of antagonism on the contraction induced in guinea-pig lung parenchymal strips and on platelet aggregation and shape change. After 10 min pre-incubation dichloromethane extracts containing 30 or 100 microg mL(-1) inhibited the contraction induced by prostaglandin D2 (PGD2) in guinea-pig lung parenchymal strips with dose ratios (DR) of 0.76+/-0.14 and 0.93+/-0.19, respectively; the amount of inhibition depended both on the concentration and on the time of pre-incubation (DR after 30 min pre-incubation was 1.21+/-0.51). The dichloromethane extract and its semi-purified fractions also inhibited the contractions induced by U46619, a more potent, stable, synthetic agonist of thromboxane A2 (TxA2) prostanoid (TP) receptors, the receptors acted upon by PGD2 to produce lung contractions. The dichloromethane extract did not inhibit the lung parenchymal contractions induced by histamine, leukotriene D4 (LTD4) or platelet-activating factor (PAF). Platelet aggregation induced by U46619, adenosine 5'-diphosphate (ADP) or PAF was not inhibited by the dichloromethane extract. Indeed, the extract potentiated platelet aggregation induced by low concentrations of these agonists and also potentiated the shape change induced by U46619. These results imply that the dichloromethane extract of Anchietia salutaris and its semi-purified fractions contain an active principle that competitively inhibits TxA2 TP receptors, the stimulation of which causes lung parenchymal contraction. The inhibition seems to be selective for this receptor subtype, because the extract fails to inhibit platelet aggregation or shape change. This provides additional support of earlier reports suggesting the occurrence of TP receptor subtypes.