Analytical study on effect of ring geometry on frequency shift of piezoelectric ring-shaped resonator

Ring-shaped resonators with one and four-point-outer-pinned supports have been designed in this work. The ring-shaped resonator reacts with a mass perturbation to provide eigenstate or frequency shifts which could transfer to electrical signals by piezoelectric effect. The aforementioned ring-shaped resonator is mainly comprised with a multilayer of Pt/Ti/PZT/Pt/Ti/SiO₂ deposited on the silicon-on-insulator wafer and expected to be a contour mode. In order to estimate the sensitivity of the ring-shaped resonator against the mass perturbation, the theoretical analysis was conducted by ANSYS from two aspects including: (a) the view point of geometrical design and (b) the mass application methodology. When a mass perturbation (i.e., a liquid droplet) of 10?pg is homogeneously contacting on the top electrode of the resonator, frequency shifts from 2.11 to 4.07?kHz could be obtained when excited in the contour mode. Furthermore, the more stabled vibration behavior of resonator with four-point-pinned supports was approved by the computer stimulation of ANSYS analysis results.     

Development of thin film based flexible current clamp sensor using screen-printed coil

This paper reports a novel flexible current clamp sensor with 480 turns silver paste coil (line/space = 50/50 μm) formed by through-holes and screen-printing technologies. Using screen-printing techniques, fine stripe patterns could be formed on a 50-mm-long and 10-mm-wide polyimide film in few seconds. Coil resistance between their contact pads is about 2.3 kΩ. When the value of a primary current was 20 A, the output voltage was 22.6 mV. Furthermore, the output voltage changed linearly with the changing of the primary current in the 0–20 A range. The sensor is developed using only coating, through-holes laser drilling, and screen-printing technologies. Therefore it can be fabricated by a reel-to-reel continuous film processing system.     

Color correction for multi-view video using energy minimization of view networks

Systems using numerous cameras are emerging in many fields due to their ease of production and reduced cost, and one of the fields where they are expected to be used more actively in the near future is in image-based rendering （IBR）. Color correction between views is necessary to use multi-view systems in IBR to make audiences feel comfortable when views are switched or when a free viewpoint video is displayed. Color correction usually involves two steps： the first is to adjust camera parameters such as gain, brightness, and aperture before capture, and the second is to modify captured videos through image processing. This paper deals with the latter, which does not need a color pattern board. The proposed method uses scale invariant feature transform （SIFT） to detect correspondences, treats RGB channels independently, calculates lookup tables with an energy-minimization approach, and corrects captured video with these tables. The experimental results reveal that this approach works well.     

Construction of a diabody (small recombinant bispecific antibody) using a refolding system

Diabodies are the recombinant bispecific antibodies (BsAbs),constructed from heterogeneous single-chain antibodies. Usually,diabodies have been prepared from bacterial periplasmic fractionusing a co-expression vector (i.e. genes encoding two chainswere tandemly located under the same promoter). Some diabodies,however, cannot be expressed as a soluble material owing toinclusion body formation, which limits the utilization of diabodiesin various fields. Here we report an improved method for theconstruction of diabodies using a refolding system. As a model,a bispecific diabody binding to adenocarcinoma-associated antigenMUC1 and to CD3 on T cells was studied. One chain consistedof a VH specific for MUC1 linked to a VL specific for CD3 witha short polypeptide linker (GGGGS). The second was composedof a VL specific for MUC1 linked to a VH specific for CD3. Thetwo hetero scFvs were independently obtained from intracellularinsoluble fractions of Escherichia coli, purified, mixed stoichiometrically(at an equivalent molar ratio of 1:1) and refolded. The refoldedtwo hetero scFv has a hetero-dimeric structure, with completespecificity for both target cells [i.e. MUC1 positive cellsand CD3 positive lymphokine-activated killer cells with a Tcell phenotype (T-LAK)]. Evaluation of the in vitro efficacyof T-LAK with the diabody by growth inhibition assay of cancercells demonstrated maximum growth inhibition of cancer cellsto reach ~98% at an effector:target ratio (E:T ratio) of 10,almost identical with that with anti-MUC1xanti-CD3 chemicallysynthesized BsAbs (c-BsAbs). This is the first report of theconstruction of a diabody using a refolding system.     

Study of crescent shaped alignment marks applicable to self-alignment of micro-parts with and without positive and negative poles

A “crescent-shaped” binding alignment mark, more applicable to the self-alignment than reported “tear-drop/elliptical hole” pattern, has been designed and comparatively studied with other possible alignment marks. In order to further apply this novel design to micro-parts with positive and negative poles on the binding sites, a modified “crescent-shaped” pattern with an insulated space area, defined as “crescent-shaped/interval” for self-alignment of micro-parts with two poles has been therefore proposed and discussed. The fabrication process using micromachining has been studied and both the substrates and micro-parts with alignment marks have been fabricated for next self-alignment verification.     

Corner Separations around a NACA65 Blade in a Decelerating Flow （Experi- mental Investigations by Five-Hole Probe and PIV）

In order to examine the fundamental characteristics of corner separation in a decelerating cascade flow,the experimental apparatus was made and separations around a NACA65 blade in a decelerating channel flow were examined.Two-dimensional calculations show that the NACA65 cascade flow that has 45 deg.of turning,1.24 of solidity and 17 deg.of stagger angle is equivalent to the channel flow that has 14 deg.of stagger angle in terms of pitchwise blade force.Experimental investigation by five-hole probe shows that the accumulations of low energy fluid can be seen around the corner part and the overturning flow due to the secondary flow exists.And,as the periodicity of the blade wake in a pitchwise direction is comparably good,the wake of this channel flow is similar to the wake of the cascade flow for two pitch portion.PIV measurement results shows that a vortex pattern can be seen in the momentary streamline on the suction surface of the blade and in the averaged streamline on the perpendicular to both the suction surface and the endwall.     

Interface Motion Driven by Capillary Action in Circular and Rectangular Microchannel

In microchannel flow, gas–liquid interface behavior will be important for developing a wide range of microfluidic applications, especially in micro reactors. In this article, we discuss some topics related to capillary action and two-phase fluid behavior in a microchannel. One of the topics is interface motion in the flow driven only by capillary action. We examined circular and rectangular microchannels with diameters of 50 μm, 85 μm × 68 μm, and 75 μm × 48 μm, respectively. For the circular channel, experiments well agreed with the previous theory in the case of ethyl alcohol as the test liquid. The effects of inner surface condition are found to be critical for interface motion on a microscopic scale. We have extended our theory to a rectangular microchannel. We obtained the same formula of relation between non-dimensional time and interface position as that of the circular channel. We compared predictions with experimental results of a PDMS microchannel. They agreed qualitatively, but not quantitatively. The difference was considered to be caused by contact angle estimation.     

Fracture strength estimation of SiC block for IS process

The Japan Atomic Energy Agency has been conducting R&D on thermochemical water-splitting Iodine–Sulfur (IS) process for hydrogen production to meet massive demand in the future hydrogen economy. A concept of sulfuric acid decomposer was developed featuring a heat exchanger block made of SiC. Recent activity has focused on the reliability assessment of SiC block. Although knowing the strength of SiC block is important for the reliability assessment, it is difficult to evaluate a large-scale ceramics structure without destructive test. In this study, a novel approach for strength estimation of SiC structure was proposed. Since accurate strength estimation of individual ceramics structure is difficult, a prediction method of minimum strength in the structure of the same design was proposed based on effective volume theory and optimized Weibull modulus. Optimum value of the Weibull modulus was determined for estimating the lowest strength. The strength estimation line was developed by using the determined modulus. The validity of the line was verified by destructive test of SiC block model, which is small-scale model of the SiC block. The fracture strength of small-scale model satisfied the predicted strength.     

Experimental study on heat transfer and pressure drop in mercury flow system for spallation neutron source

In the design of MW-class spallation target system, using mercury to produce practical neutron applications, keeping the highest level of safety is vitally important. To establish the safety of spallation target system, it is essential to understand the thermal hydraulic properties of mercury. Through thermal hydraulic experiments using a mercury experimental loop, which flows at the rate of 1.2 m³/hr maximum, the following facts were experimentally confirmed. The wall friction factor was relatively larger than the Blasius correlation due to the effects of wall roughness. The heat transfer coefficients agreed well with the Subbotin correlation. Furthermore, for validation of the design analysis code, thermal hydraulic analyses were conducted by using the STAR-CD code under the same conditions as the experiments. Analytical results showed good agreement with the experimental results, using optimized turbulent Prandtl number and mesh size.