Technique for detecting flaws in metallic surfaces using an optical system with phase-type blazed gratings

In this paper, we evaluate a novel flaw-detection technique for metallic surfaces based on the use of phase-type blazed gratings. Transparent blazed gratings were prepared by the soft nanoimprint method involving the transfer of a template (a reflective grating structure used for spectroscopy) onto silicone rubber. The blazed gratings were then integrated into an imaging system to observe the reflective metal sample. Due to the low-pass-filtering properties of the gratings, the captured image was notably blurred. This characteristic aids in flaw detection on metallic surfaces because the captured image is adequate to distinguish flaws in the targeted area on the basis of the texture of the rough surface, including any other structures that were unintended. The use of double-sided gratings with crossing grating vectors was found to be efficient for homogenous low-pass filtering. Such flaw-detection techniques are expected to be useful for conducting quality inspections of rolled steel plates since the surface contains both a rough surface and undesirable flaws.     

4032 ppi High‐resolution OLED microdisplay

A 0.5‐inch Ultra Extended Graphics Array (UXGA) organic light‐emitting diodes microdisplay has been developed with 6.3 μm pixel pitch. Not only 4032 ppi high resolution but high frame rate, low power consumption, wide viewing angle, and high luminance have been achieved. This newly developed organic light‐emitting diodes microdisplay is suitable for Near‐to‐Eye display applications, especially electronic viewfinders.     

Room-temperature densification of MgO bulk ceramics with dispersed nitride phosphor particles

Wave conversion materials with high thermal conductivity are necessary for high-power semiconductor lighting. Ceramics have higher thermal conductivity than existing matrices such as resin or glass in which phosphor particles are dispersed. However, the high densification of ceramics generally requires high-temperature sintering, which degrades and alters the phosphor particles. In this study, we aimed to achieve the high densification of MgO ceramics at room temperature. Applying high hydrostatic pressure with water addition improved the sample packing ratio and promoted the formation of Mg(OH)₂. As a result, the relative density was ≥95%. Additionally, various nitride phosphor particles (CaAlSiN₃:Eu²⁺, β-SiAlON:Eu²⁺, and α-SiAlON:Eu²⁺) were dispersed in the MgO matrix at room temperature without degrading the luminescence property. The thermal conductivity of the obtained sample was about 8 W m^?1K^?1, 40 times higher than that of the epoxy matrix.     

Contribution of known endocrine disrupting substances to the estrogenic activity in Tama River water samples from Japan using instrumental analysis and in vitro reporter gene assay

To quantitatively characterize the substances contributing to estrogenic activity in river water, in vitro bioassay using MVLN cells and instrumental analysis using liquid chromatograph–mass spectrometer (LC/MS) or liquid chromatograph–tandem mass spectrometer (LC/MS/MS) were applied to river water extracts taken from various locations in the Tama River, Japan. Tama River water samples were extracted using solid phase extraction and the crude extracts were fractionated by high-performance liquid chromatography (HPLC) into 10 fractions. The sixth fraction contained nonylphenol (NP) and octylphenol (OP) at concentrations in the range of 51.6–147 and 6.9–81.9 ng/L, respectively (concentrations corresponding to the original sample volumes). No estrogenic activity, expressed as 17β-estradiol equivalents (E2-EQ_B), however, was observed in this fraction (<0.6 ng-E2eq/L). Instrumentally determined estrogenic activity (E2-EQ_C), which is the concentrations of NP and OP multiplied by their corresponding relative potency, was below the detection limit of the MVLN cell bioassay. Estrogenic activities were detected only in HPLC fraction nos. 7, 8 and 9. Estrone (E1), estradiol (E2) and bisphenol A (BPA) were detected in these fractions. Estriol (E3) and ethynylestradiol (EE2) were not detected (<0.2 ng/L) in these fractions. The calculated E2-EQ_C for BPA was below the detection limit of bioassay. The E2-EQ_C for E1 and E2 were on the same order as the estrogenic activity determined by the bioassay (E2-EQ_B). The ratios of E2-EQ_C and E2-EQ_B for E1 and E2 in the three factions collectively (nos. 7–9) were 0.49–0.97 and 0.29–1.12, respectively. Above results indicated that the major causal substances to the estrogenic activity in the Tama River were E1 and E2.     

Two different types of age-hardening behaviors in commercial dental gold alloys

Age-hardening behavior during continuous heating in commercial dental casting gold alloys was investigated by means of electrical resistivity measurements, hardness tests and X-ray diffraction. Two distinguishable behaviors were detected. It is considered that the difference was attributed to the amount of platinum, and the atomic ratio of gold and copper in each alloy. The phase transformations during continuous heating progressed into two steps (stages I and II). Increase of the platinum addition in gold-based alloys retards the rate of the reaction and decreases remarkably the amount of stage I.     

Effects of defocus and algorithm on optical step height calibration

Defocus effects on step height measurements by interferometric microscopy are estimated using different algorithms to calculate the step height. The interferometric microscope here is a Mirau-type with a 20x objective and a numerical aperture (NA) of 0.4. Although the focus is adjusted within the range of the depth of focus, a defocus corresponding to 4 fringes (1.3 μm) distorts the measured profile into a curve with a radius of curvature of about 24 m. The effect of this distortion on step height determination by a basic ISO step height algorithm is estimated to be 0.11 nm/fringe. An algorithm developed by NIST and a second-order fitted ISO step-height algorithm show good robustness against defocus errors. Because of sample imperfection, a discrepancy of about 1 % exists among step-height values determined by the different algorithms at the optimum fringe contrast position. It has been pointed out theoretically that the NA correction factor varies with the difference of optical path length between the sample and the reference surface. However, in our case, the changes of optical path length do not change the NA correction factor by more than 0.3 %.     

Precise metabolic flux analysis of coryneform bacteria by gas chromatography-mass spectrometry and verification by nuclear magnetic resonance

Precise metabolic flux analysis (MFA) by gas chromatography-mass spectrometry (GC-MS) and computer calculation was performed, and the consistency of the estimated results was verified by independently performed nuclear magnetic resonance (NMR) analysis. The precise estimation of flux by the integration method of the mass isotopomer signal, defined as the coefficient of variance (CV) of multiple determination, was investigated, and the results estimated using different data sets with the same magnitude of error were confirmed. The CV of multiple determinations was sufficiently small to discuss and compare the fluxes of a metabolic pathway. The estimated fluxes using the GC-MS data were cross-validated with the NMR data that were independently measured and not used for MFA. The developed method was successfully applied to the MFA of the growth phase of two different glutamate-producing coryneform bacteria, Corynebacterium glutamicum and C. efficiens. The difference in the growth rate between these two bacterial species was discussed while considering the results of MFA, including forward and backward (exchange) fluxes.     

Continuous path control of a 5-DOF parallel-serial hybrid robot

Using the 5-degree of freedom parallel-serial hybrid robot, to realize the de-burring, new forward and inverse kinematic calculation methods based on the “off-line teaching” method are proposed. This hybrid robot consists of a parallel stage section and a serial stage section. Considering this point, each section is calculated individually. And the continuous path control algorithm of this hybrid robot is proposed. To verify the usefulness, a prototype robot is tested which is controlled based on the proposed methods. This verification includes a positioning test and a pose test. The positioning test evaluates the continuous path of the tool center point. The pose test evaluates the pose on the tool center point. As the result, it is confirmed that this hybrid robot moves correctly using the proposed methods.     

Cross-section analysis of electric devices by scanning capacitance microscope

Carrier influence of semiconductor devices is important as it affects the function of the device. In this experiment, the carrier density distribution in the cross-section of semiconductor device was analyzed by SCM: Scanning Capacitance Microscope which is one of the measuring mode of SPM: Scanning Probe Microscope.This paper describe measurement result of change in carrier density by the gate voltage at p channel area of CMOS device and its efficiency to investigating dopant profile on 16MDRAM cross-section.