Electroforming for replicating nanometer-level smooth surface

We proposed and developed a new electroforming process for the replication of surfaces having nanometer-level smoothness. In the electroforming process, the separation method plays an important role in preventing the degradation of the surface morphology. The key point in this process is the fabrication of a metal film as an electrode on the master surface. Cr atoms are deposited by an arc plasma deposition method and act as a binding material. Subsequently, a nickel film is fabricated by electron beam deposition to form an electrode. Electrodeposition is then carried out in a nickel sulfamate bath. By controlling the density of Cr atoms on the master surface, the binding strength between the nickel film and master surface can be adjusted, which makes it possible to separate the metal film from the master surface smoothly. As a result, a surface roughness of 0.22 nm (root mean square) has been achieved in a 64 microm x 48 microm area of a replicated surface.     

Improved optical and electrical characteristics of free-standing GaN substrates by chemical polishing utilizing photo-electrochemical method

The optical and electrical properties of GaN(0001) surfaces treated by a novel chemical polishing method are described. Scanning microscopic photoluminescence images reveal that the polished GaN surface shows improved luminescence properties compared to the untreated surface. Current-voltage measurements of Schottky barriers formed using the GaN substrates show that the polished GaN surface has a lower reverse leakage current, and that the barrier height and ideality factor are improved after the polishing treatment.     

Effect of subchronic feeding of genetically modified corn (CBH351) on immune system in BN rats and B10A mice

Subchronic animal feeding studies to examine the effect on the immune system of genetically modified corn CBH351, which contains the Cry9C protein derived from Bacillus thuringiensis subspecies tolworthi, were conducted in female BN rats and B10A mice. The studies were designed to compare the effect of a line of genetically modified corn CBH351 (GM corn) with that of isoline corn (non-GM corn). Heat-treated corn meal was incorporated into the diets of the rats and mice at a concentration of 50%. The study duration was 13 weeks. Growth, food intake, and organ weights of the thymus, spleen, and liver were compared between animals fed the non-GM and GM lines. The histological findings in thymus, spleen, mesenteric lymph nodes, Peyer's patches, small intestines, liver, kidney, and bone marrow, and the presence of Cry9C-specific IgE, IgG, IgG1 and IgA antibodies in serum were also compared. The results showed no significant differences in growth, feeding value, or the histological findings in immunity-related organs between the animals fed the GM and non-GM lines. Production of Cry9 C-specific IgE and IgA was not detected in the serum of either group. Production of Cry9C-specific IgG and IgG1 was slightly increased in the 50% GM groups of BN rats. No Cry9C-specific IgG or IgG1 was detected in the serum of BN rats fed the diet containing 5% GM-corn In conclusion, no immunotoxic activity was detected in the GM-corn-fed rats and mice in this subchronic dietary study.     

Stress intensity factors of a central interface crack in a bonded finite plate and periodic interface cracks under arbitrary material combinations

Although a lot of interface crack problems were previously treated, few solutions are available under arbitrary material combinations. This paper deals with a central interface crack in a bonded finite plate and periodic interface cracks. Then, the effects of material combination and relative crack length on the stress intensity factors are discussed. A useful method to calculate the stress intensity factor of interface crack is presented with focusing on the stress at the crack tip calculated by the finite element method.     

Effect of chromatic aberration on atomic-resolved spherical aberration corrected STEM images

The effect of the chromatic aberration (_Cc)$(C_c)$ coefficient in a spherical aberration (_Cs)$(C_s)$- corrected electromagnetic lens on high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscope (STEM) images is explored in detail. A new method for precise determination of the _Cc$C_c$ coefficient is demonstrated, requiring measurement of an atomic-resolution one-frame through-focal HAADF STEM image. This method is robust with respect to instrumental drift, sample thickness, all lens parameters except _Cc$C_c$, and experimental noise. It is also demonstrated that semi-quantitative structural analysis on the nanometer scale can be achieved by comparing experimental _Cs$C_s$- corrected HAADF STEM images with their corresponding simulated images when the effects of the _Cc$C_c$ coefficient and spatial incoherence are included.     

Thermal Conductivity of the Molten CaO-SiO2-FeO x System

Thermal conductivity measurements were carried out on synthetic steelmaking slag using the hot-wire method. Furthermore, local structure analysis in the melts was carried out in order to investigate the relationship with the composition dependence. The thermal conductivity of the CaO-SiO₂-FeO _x melts significantly decreased as the content of FeO _x increases, particularly at lower basicity. Both chemical analysis and the observation show that the amount of Fe²⁺ increases when CaO/SiO₂ is smaller, implying more basic behavior of FeO than FeO_1.5. According to further analyses by M?ssbauer spectroscopy, the degree of basicity of FeO_1.5 remains virtually unchanged in the composition range of interest. From the experimental results, it could be concluded that the thermal conductivity of the silicate melt containing iron oxide is highly dependent on the valence of the Fe ion and comparatively independent of the amphoteric behavior of FeO_1.5.     

Comparative study of the histochemical properties, collagen content and architecture of the skeletal muscles of wild boar crossbred pigs and commercial hybrid pigs

The histochemical properties, collagen content and architecture of Musculus longissimusthoracis (LT), Musculus pectoralis profundus (PP) and Musculus biceps femoris (BF) were compared in F(1) (half blood) and F(2) (quarter blood) wild boar crossbred pigs and commercial hybrid pigs, and Japanese wild pigs. F(1) pigs showed the lowest growth rate, followed by F(2) pigs. The most rapid growth was shown by the commercial pigs. The percentage weights of LT and PP muscle to body weight were larger in the wild boar crossbred pigs than commercial pigs. The muscles of the crossbred pigs contained type I and IIA myofibers at higher frequency and type IIB at lower frequency than the commercial pigs, except for LT muscle of F(2) pigs. The myofiber diameter in each type of muscle did not differ between pigs except for the smaller type IIA in BF muscle in commercial pigs. The total amount of intramuscular collagen was less in LT muscles than the others. More intramuscular collagen was found in the wild boar crossbred pigs than the commercial pigs in LT and PP muscles. With an increase of collagen content, the perimysial collagen architecture developed but not the endomysial architecture. Traits characteristic of the crossbred pigs seem to be inherited from the wild boar. Our results clarify that cross breeding with wild boar results in pigs with distinctive muscle characteristics in terms of histochemical properties, collagen content and architecture.     

Reliability evaluation of ultra-thin CSP using new flip-chip bonding technology––double-sided CSP and single-sided CSP

A high-density packaging technology has been developed that uses new flip-chip bonding technology with a thin IC and a thin substrate. Numerical analysis with the finite element method as well experiments clearly showed that deflection of the IC and reliability were affected by the IC thickness. Consequently, reliability could be improved by reducing IC thickness. The dependency of the life in single-sided chip-size packages (CSPs) could be expressed using a normal stress value in thickness, which is computed by the IC thickness and substrate type and thickness. The dependency of the life in double-sided CSPs could be expressed using a shear stress value in the vertical cross section, which is computed in IC thickness and substrate type and thickness, respectively.Moreover, a double-sided flip-chip approach solved the problem of warpage. A high-capacity memory card of 512 MB was put to practical use by applying these results. This increased the Si density by four times over that of a conventional CSP.     

Retrieval process of high-resolution HAADF-STEM images

A process for retrieving experimental high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images, which are systematically distorted by environmental and/or instrumental instability in addition to the convolution influence of the probe, is demonstrated using a HAADF-STEM image of an antimony-rich basal plane inversion boundary in Sb2O3-doped ZnO ceramics recorded in the [0110] zone axis. The process includes a correction of the diffractogram of the HAADF-STEM image by referring to the diffractogram of a high-resolution transmission electron microscopy image of the same area. The corrected diffractogram is used for deconvolution processing combined with the maximum entropy method. The retrieved images show bright spots regarded as the object function. Thus, the processing of the experimental HAADF-STEM image provides almost a real projected atomic structure by reforming the systematic distortion and eliminating the effects of the probe function.     

Cooling Curve''''s Effect on Hardening Behavior of Steel

TO QUENCH HARDEN STEEL MATERIAL,it isrequired to give rapid quenching in the temperaturerange required of rapid quenching.On the other hand,quenching oil comprised of mineral oil as majorcomponent can be modified of its cooling curve byusing various additives.Thereby,we havequench-hardened some steel material each havingdifferent pattern of CCT curve,using quenching oilcomprised of mineral oil modified of coolingcharacteristics by dosing additives,and surveyedrelationship between ha…