Intrinsic microwave dielectric loss of lanthanum aluminate

The intrinsic dielectric properties of LaAlO? were investigated to understand the microwave properties of several materials containing LaAlO?. In this study, LaAlO? single crystals were prepared by the Czochralski method. The temperature dependence of the dielectric properties and neutron inelastic scattering of the single crystals were measured. From these data, the intrinsic dielectric properties were evaluated and it was found that the dielectric loss of the LaAlO? includes two types of dielectric loss. One is a phonon absorption-related loss and the other is a component of the loss arising from Debye- type orientation polarization. The latter affects the room temperature dielectric loss in materials containing LaAlO?. The present study suggests that avoiding this polarization loss is an important goal in decreasing the total dielectric loss.     

Design of Fully Balanced Analog Systems Based on Ordinary and/or Modified Single-Ended Opamps

The system architectures, which allow a high performance fully balanced (FB) system based on ordinary/modified single-ended opamps to be implemented, are investigated and the basic and general requirements are formulated. Two new methods of an FB analog system design, which contribute towards achieving both a high performance IC system implementation and a great reduction of the design time are presented. It is shown that a single-ended system based on any type of opamp (rail-to-rail, constant g _m , etc.), realized in any technology (CMOS, bipolar, BiCMOS, GaAs), can be easily and effectively converted to its FB counterpart in a very practical way. Using the proposed rules, any FB system implementation with opamps (data converter, modulator, filter, etc.) requires only a single-ended system version design and the drawbacks related to a conventional FB system design are avoided. The principles of the design are pointed out and they are verified by experimental results.     

The Uncertainty in SCHF‐DT Thermal Conductivity Measurements of Lotus‐Type Porous Copper

Lotus‐type porous metals with many straight pores are attractive for use as heat‐sinks because a large heat‐transfer capacity can be obtained, due to the small diameter of the pores. In order to use lotus‐type porous copper effectively as a heat sink, it is important to know the effective thermal conductivity considering the effect of pores on heat conduction in the material. Since these metals have anisotropic pores, a steady‐state comparative longitudinal heat‐flow method for measuring thermal conductivity, referring to an ASTM standard, is better than other methods. So far, the effective thermal conductivity of lotus‐type porous copper has been measured by using specimens of different thickness (the SCHF‐DT method). In this paper, the uncertainty in the effective thermal conductivity of a specimen measured using this method was evaluated by comparison between numerical analysis and current experimental data. The following conclusions were drawn: 1) The uncertainty showed good agreement with the uncertainty analysis; 2) The contribution of the thermal grease thickness was large, based on a combined standard uncertainty analysis; and, 3) The effective thermal conductivity perpendicular to the pores of lotus copper can be measured within 10% uncertainty by this method.     

Epitaxial growth of Cu6Sn5 formed at Sn-based lead-free solder/non-textured polycrystalline Cu plate interface

This study examines the epitaxial growth of the intermetallic compound (IMC) of Cu₆Sn₅ (or (Cu,Ni)₆Sn₅) that forms at the interface between molten Sn-based lead-free solders and non-textured polycrystalline Cu substrates. Sn, Sn–Cu, Sn–Cu–Ni and Sn–Ag–Cu solders were investigated. The dominant growing planes in a hexagonal structure of this IMC on Cu substrates are (101) and (102). Addition of trace Ni into Sn–Cu solders leads to an increase in (101) growth and a decrease in (102) growth. The presence of Ag in Sn–Ag–Cu solders facilitates (102) growth and suppresses (101) growth. Such an epitaxial growth should have a large influence on the mechanical and electrical characteristics of the Sn-based solder/Cu joints.     

Development and Use of a Kinetical and Real-Time Monitoring System to Analyze the Replication of Hepatitis C Virus

In microbiological research, it is important to understand the time course of each step in a pathogen’s lifecycle and changes in the host cell environment induced by infection. This study is the first to develop a real-time monitoring system that kinetically detects luminescence reporter activity over time without sampling cells or culture supernatants for analyzing the virus replication. Subgenomic replicon experiments with hepatitis C virus (HCV) showed that transient translation and genome replication can be detected separately, with the first peak of translation observed at 3–4 h and replication beginning around 20 h after viral RNA introduction into cells. From the bioluminescence data set measured every 30 min (48 measurements per day), the initial rates of translation and replication were calculated, and their capacity levels were expressed as the sums of the measured signals in each process, which correspond to the areas on the kinetics graphs. The comparison of various HuH-7-derived cell lines showed that the bioluminescence profile differs among cell lines, suggesting that both translation and replication capacities potentially influence differences in HCV susceptibility. The effects of RNA mutations within the 5′ UTR of the replicon on viral translation and replication were further analyzed in the system developed, confirming that mutations to the miR-122 binding sites primarily reduce replication activity rather than translation. The newly developed real-time monitoring system should be applied to the studies of various viruses and contribute to the analysis of transitions and progression of each process of their life cycle.     

Color restoration method based on spectral information using normalized cut

This paper proposes a novel method for color restoration that can effectively apply accurate color based on spectral information to a segmented image using the normalized cut technique. Using the proposed method, we can obtain a digital still camera image and spectral information in different environments. Also, it is not necessary to estimate reflectance spectra using a spectral database such as other methods. The synthesized images are accurate and high resolution. The proposed method effectively works in making digital archive contents. Some experimental results are demonstrated in this paper.     

IN-situ monitoring of hydrogen transfer in carbonization reaction by well resolved high-temperature 1H NMR

By means of a well resolved high-temperature ¹H NMR technique, the carbonization process of acenaphthylene as well as the hydrogen transfer from some model compounds and decant oil to anthracene and/or acenaphthylene have been studied. The hydrogen transfer reaction was found to take place in the liquid phase at temperatures above 630 K for the decant oil/anthracene system.     

T1ρ study of pitch softening

Proton rotating frame spin-lattice relaxation time (T_1ρ) measurements have been made in 10 samples of pitch from room temperature to 673 K to obtain information about the mechanisms of pitch softening. The T_1ρ minimum of pitch was found to occur at approximately the same temperature as the softening point. This result suggests that the softening phenomenon of pitch can be detected at the molecular level by T_1ρ measurements. Laboratory frame spin-lattice relaxation time (T₁) measurements were also made on pitches to obtain information about the molecular motion of pitch in the high frequency ranges.     

The CO2 solubilities of highly basic melts

The CO₂ solubilities of highly basic melts have been measured by equilibrating samples with a gas phase. According to the results, the investigated oxides can be arranged as follows in order of decreasing basicity; K₂O>Na₂O>Li₂O, BaO > CaO, SO₃ ? CrO₃ > BO_1.5 > SiO₂ > PO_2.5. By comparing the solubility data with optical theoretical basicity value, sulfide capacity, phosphate capacity and activity of CaO, it has been found that the carbonate capacity is a good measure of slag basicity.     

Multimode oscillator analysis via integral manifolds part II: Resonant case

This article represents Part II of a two-part paper which provides a rigorous mathematical foundation of the modeanalysis method for analysing the periodic and quasi-periodic oscillation observed in various types of coupled oscillators. Although the results predicted by this method had been confirmed by experiments to some extent, the crucial assumptions used to derive the averaged equations are based on engineering intuition. Moreover, while it is intuitively reasonable to associate an equilibrium solution of the averaged equations whose eigenvalues have negative real parts with that of a stable periodic or quasi-periodic solution of the original equation, the relationship between the solution of the averaged equations and that of the original equations as t tends to infinity, is not clear in a mathematical sense. This paper resolves the theoretical ambiguities of the mode analysis method by using the theory of integral manifolds. In particular, we recalculate the averaged equations in a rigorous way, and show that they coincide with those obtained before. Thereore, the theory of integral manifolds guarantees the existence of an integral manifold in the original system which corresponds to a steady-state periodic or quasi-periodic solution, provided the equilibrium point of the averaged equation has no eigenvalues with a zero real part (i.e. hyperbolic. This rigorous analysis proved that all our previous results obtained from the mode analysis method, i.e. averaged equations and the analysis were correct.