Infrared Microscopy for Examination of Structure in Spray-Dried Granules and Compacts

Novel infrared microscopy has been developed to improve the liquid-immersion method, which is a technique that has been developed by the authors to study the packing structures of powder particles in ceramic green bodies. This paper demonstrates the high potential of the novel technique by presenting clear structures of Si₃N₄ powder granules and their compacts.     

Microscale Contacting of Two Immiscible Liquid Droplets to Measure Interfacial Tension

In various microfluidic devices, surface tension and interfacial tension values are necessary to analyze the fluid behavior in microchannels, and evaluating the values of interfacial tension is especially important for gas–liquid and liquid–liquid flows. A pendant drop method is commonly used to measure the interfacial tension value; however, the pendant drop method requires strict accuracy in measuring the droplet size when the droplet has a nonspherical shape, as well as an accurate value of the density difference between the two liquids. In this work, a new measurement method called the “liquid bridge-inducing microscale contact method” has been developed in which the interfacial tension can be obtained from the bridging of two liquid droplets extruded from opposing ends of glass capillary tubes or formed on the ends of round metal rods. By measuring the radii of curvature of each liquid surface and interface, we calculate the Laplace pressure on the surface and interface, and derive the interfacial tension value using the Laplace equation. The results show that the values of interfacial tension obtained from the two methods are approximately the same and that the liquid bridge-inducing microscale contact method is capable of accurate interfacial tension measurements.     

Pumping experiment of water on B and LaB6 films with an electron beam evaporator

The pumping characteristic of water vapor on boron and lanthanum hexaboride films formed with an electron beam evaporator have been investigated in high vacuum between 10⁻⁴ and 10⁻³ Pa. The measured initial maximum pumping speeds of water for the fresh B or LaB₆ films with a deposition amount from 2.3 × 10²¹ to 6.7× 10²¹ molecules/m² separately formed on a substrate are 3.2–4.9 m³/sm², and the saturation values of adsorbed water on these films are 2.1 ×10²⁰−1.3 × 10²¹ H₂O molecules/m².     

Synthesis of the Orthorhombic Phase of 2Y˙ZrO2

A mixture of tetragonal and monoclinic 2Y˙ZrO₂ (2 mol% Y₂O₃–ZrO₂) powder was treated from 400° to 800°C and from 4 to 7 GPa for 30 min. The products were identified by powder XRD, Raman spectroscopy, and TEM. Results indicated that an orthorhombic phase was synthesized at T=400° to 600°C and P>4 GPa. The lattice parameters were obtained as a=0.505, b=0.525, and c=0.509 nm; the density was 6.17 Mg/m³. The orthorhombic phase always coexisted with the tetragonal phase in the products. The amounts of the tetragonal phase before and after treatment remained largely unchanged, whereas the amount of new orthorhombic phase was nearly the same as the decreased amount of the monoclinic phase. It was assumed, therefore, that only the monoclinic phase transformed into the orthorhombic phase.     

Progress in large-area Cu(InGa)Se2-based thin-film modules with a Zn(O,S,OH)x buffer layer

Applying basically the same innovative and robust fabrication technologies which, for the first time, led to the achievement of remarkably high efficiency of 14.2% at an aperture area of 51.7 cm² with a Zn(O,S,OH)_x buffer layer, the following goals have been targeted: (1) 13% efficiency on a 30 cm×30 cm module and (2) establishment of the fabrication technologies to attain 140 yen/W_p in the annual production capacity of 100 MW_p/a. The main focus is currently on the technology development (1) to increase the V_oc related to the CIGS absorber and (2) to improve the J_sc related to the DC-sputtered ZnO window layer with a multilayered structure. This contribution well explains the status and strategy of Showa Shell Sekiyu K.K. on the R&D of CIGS-based thin-film modules to achieve the above two goals by the end of FY2000.     

Crank‐shaped and Y‐shaped through‐hole interconnections filled with Au‐Sn solder

Crank‐shaped and Y‐shaped through‐hole interconnections (THI) filled with Au‐Sn solder are demonstrated in this study. They are expected to realize a higher‐density wafer‐level package (WLP) for electrical devices including the fields of MEMS (Micro Electro‐Mechanical Systems) and MOEMS (Micro Optical Electro‐Mechanical Systems) compared with conventional WLP using THI consisting of straight through‐holes. In this paper, formation techniques for crank‐shaped and Y‐shaped THI are described. In order to make crank‐shaped and Y‐shaped through‐holes in a substrate, both femtosecond laser irradiation and wet chemical etching are used. Crank‐shaped through‐holes with an 80‐μm opening and 400 μm deep have also been achieved. Gold (Au)‐tin (Sn) solder was filled into the holes using the molten metal suction method (MMSM). Airtightness of the THI was examined using the helium leakage test, and the estimated leakage rate was less than 1.0 × 10^?9 Pa·m³/s, which is sufficient for use in WLP applications. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(1): 54–62, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com) . DOI 10.1002/eej.21134     

Feasibility of in vivo three-dimensional T<Stack><Subscript>2</Subscript><Superscript>*</Superscript></Stack> mapping using dicarboxy-PROXYL and CW-EPR-based single-point imaging

Objectives

The aim of this study was to demonstrate the feasibility of in vivo three-dimensional (3D) relaxation time T ₂ ^* mapping of a dicarboxy-PROXYL radical using continuous-wave electron paramagnetic resonance (CW-EPR) imaging.

Materials and methods

Isotopically substituted dicarboxy-PROXYL radicals, 3,4-dicarboxy-2,2,5,5-tetra(²H₃)methylpyrrolidin-(3,4-²H₂)-(1-¹⁵N)-1-oxyl (²H,¹⁵N-DCP) and 3,4-dicarboxy-2,2,5,5-tetra(²H₃)methylpyrrolidin-(3,4-²H₂)-1-oxyl (²H-DCP), were used in the study. A clonogenic cell survival assay was performed with the ²H-DCP radical using squamous cell carcinoma (SCC VII) cells. The time course of EPR signal intensities of intravenously injected ²H,¹⁵N-DCP and ²H-DCP radicals were determined in tumor-bearing hind legs of mice (C3H/HeJ, male, n = 5). CW-EPR-based single-point imaging (SPI) was performed for 3D T ₂ ^* mapping.

Results

²H-DCP radical did not exhibit cytotoxicity at concentrations below 10 mM. The in vivo half-life of ²H,¹⁵N-DCP in tumor tissues was 24.7 ± 2.9 min (mean ± standard deviation [SD], n = 5). The in vivo time course of the EPR signal intensity of the ²H,¹⁵N-DCP radical showed a plateau of 10.2 ± 1.2 min (mean ± SD) where the EPR signal intensity remained at more than 90% of the maximum intensity. During the plateau, in vivo 3D T ₂ ^* maps with ²H,¹⁵N-DCP were obtained from tumor-bearing hind legs, with a total acquisition time of 7.5 min.

Conclusion

EPR signals of ²H,¹⁵N-DCP persisted long enough after bolus intravenous injection to conduct in vivo 3D T ₂ ^* mapping with CW-EPR-based SPI.

     

High Selective deNO x Electrochemical Cell with Self-Assembled Electro-Catalytic Electrode

A new family of electrochemical cells for decomposition of NO gas in the presence of excess O₂, in which the cathode was covered with mixed oxide layer of NiO and YSZ (electro-catalytic electrode) were designed and investigated. The deNO_x properties were increased by microstructural and compositional control of the electro-catalytic electrode. Nano-size Ni grains were self-assembled at NiO/YSZ interfaces by oxidation-reduction reaction of the NiO during the cell operation. In order to use the reduced Ni for NO decomposition reaction effectively, the authors investigated multilayering of the electro-catalytic electrode. Through this process, the adsorption of coexisting O₂ was prevented and the deNO_x properties of the electrochemical cell were improved.     

Solid insulated switchgear and investigation of its mechanical and electrical reliability

SF₆ gas is widely employed in medium‐voltage switchgear because of its high insulation reliability and down‐sizing ability. However, SF₆ gas was placed on the list of greenhouse gases under the Kyoto Protocol in 1997. Since then, research on low‐SF₆ or SF₆‐free insulation has been carried out actively. Therefore, we focused on solid materials with higher dielectric strength than SF₆, and we have now developed solid insulated switchgear (SIS) that uses molding of all main circuits. A new epoxy casting material is used which contains a large amount of spherical silica and a small amount of rubber particles. This new material has high mechanical strength, high thermal resistance, high toughness, and also high dielectric strength because of direct molding of the vacuum bottle, as well as reduced size and high reliability. This paper describes the technology of the new epoxy casting material which makes possible SIS. In addition, mechanical and electrical reliability tests of SIS using a new epoxy resin were performed, and the effectiveness of the developed material and the mechanical and electrical reliability of the SIS were verified. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 28–36, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21057     

Endoplasmic Reticulum (ER)‐Targeted,Galectin‐Mediated Retrograde Transport by Using a HaloTag Carrier Protein

Investigations into metabolic processes within the cell have often relied on genetic methods such as forced expression and knockout or knockdown techniques. An alternative approach would be introducing a molecule into the desired location inside the cell. To translocate compounds from outside cells into the endoplasmic reticulum (ER), we constructed a delivery carrier protein. This comprised N‐terminal galectin‐1 for cell‐surface binding (G1), a protease cleavable sequence (ps), a HaloTag domain for attaching exogenous compounds (Halo), and a C‐terminal KDEL sequence for ER retention. Fluorescently labeled G1‐ps‐Halo‐KDEL passed through the Golgi apparatus and reached the ER. By using Man₉GlcNAc₂‐BODIPY as a cargo compound, the carrier protein was also delivered into the ER with concomitant processing of mannose to Man_5,6, by the ER‐resident α1,2‐mannosidase. G1‐ps‐Halo‐KDEL might serve as a new type of delivery carrier protein to direct compounds into the ER.