Image analysis system for evaluating sliding behavior of a liquid droplet on a hydrophobic surface

An analysis system was developed to evaluate the sliding behavior of a liquid droplet on a hydrophobic surface. This system enables continuous and simultaneous measurement of both the sliding acceleration and shape deformation during the sliding of a liquid droplet. Moreover, the velocity vector of the internal fluidity of a sliding droplet was obtained by employing particle image velocimetry in the analysis system. This evaluation method pioneers the measurement of the dynamic wettability of a hydrophobic solid surface.     

Synthesis of poly[2-(N,N-dimethyl)aminoethyl methacrylate-co-acrylonitrile]

Summary Radical copolymerization of 2-(N,N-dimethyl)aminoethyl methacrylate (1) and acrylonitrile (2) initiated by 2,2-azobis(2-methylpropionitrile) was carried out. The sequence distributions of the copolymers were investigated by ¹³C NMR spectroscopy. A terminal model was used to interpret the propagation process in the copolymerization. The monomer reactivity ratios in the bulk copolymerization at 45°C were evaluated as r₁=1.06 and r₂=0.07. Radical reactivity indices and frontier electron densities for 1 and 2 were calculated.     

Structure of $$\langle 110 \rangle $$-tilt boundaries in cubic zirconia

Atomic structures of \(\langle 110 \rangle \)-symmetrical tilt grain boundaries in yttria-stabilized cubic zirconia are investigated from a mathematical perspective. We predicted the unique arrangement of structural units along the grain boundaries which was confirmed experimentally by atomic-resolution scanning transmission electron microscopy.     

Dissociation reaction of the 1/3$$ \left\langle {\bar{1}101} \right\rangle $$ edge dislocation in α-Al2O3

It has been reported that dislocations with 1/3\( \left\langle {\bar{1}101} \right\rangle \) edge component of the Burgers vector are formed in {1\( \bar{1} \)04}/\( \left\langle {11\bar{2}0} \right\rangle \) low-angle grain boundaries of alumina (α-Al₂O₃). These dislocations dissociate into two partial dislocations with a stacking fault on the (0001) plane (Tochigi et al. in J Mater Sci 46:4428–4433, 2011). However, the dissociation reaction of these dislocations has not been determined so far. In this study, the structures of the dissociated dislocations and the (0001) stacking fault were investigated by transmission electron microscopy and theoretical calculations. It was revealed that the dissociated dislocations were generated from the 1/3\( \left\langle {\bar{1}101} \right\rangle \) perfect edge dislocation by the reaction of 1/3\( \left\langle {\bar{1}101} \right\rangle \) → 1/18\( \left\langle {\bar{4}223} \right\rangle \) + 1/18\( \left\langle {\bar{2}4\bar{2}3} \right\rangle \). Furthermore, electron energy loss spectroscopy analysis was performed to examine the atomic/electronic structure of the (0001) stacking fault. In the observed spectra, a chemical shift and intensity decrease were found at the oxygen K-edge. Theoretical spectrum analysis using first-principles calculations revealed that the characteristic features of the spectra are originated from the local atomic configurations of the (0001) stacking fault.     

Direct Evidence of Dopant-Enhanced Grain-Boundary Sliding in Yttria-Stabilized Zirconia Bicrystals

Compression tests were conducted at 1400°C in air for undoped and Si-doped yttria-stabilized zirconia (YSZ) bicrystals with the same orientation relationship (Σ=5, [001]/{210} grain boundary). It was found that the macroscopic grain-boundary slidings are observed during the deformation in both undoped and doped bicrystals, and the sliding displacements increase almost linearly with increasing total displacements. It is distinctly demonstrated that the Si-doped bicrystal exhibits a sliding displacement that is a few times larger than the undoped bicrystal. In addition, the total strain of the Si-doped bicrystal at a failure is much larger than that of the undoped bicrystal. It can be stated that Si doping in YSZ not only enhances the grain-boundary sliding but also suppresses its failure.     

Analysis of particle trajectories of small particles in flotation when the particles and bubbles are both charged

The trajectory of a small particle moving to a bubble surface was analyzed by taking into account the effects of surface charges of the bubble and particle and the short range hydrodynamic interaction near the bubble surface, in a flotation process. The particle trajectories obtained theoretically were in good agreement with those obtained by direct observation. Even if the signs of the surface charges of the bubble and particle were the same, the particle adhered to the bubble surface when the net surface force, that is, the sum of the electrostatic force and the van der Waals force, was attractive. Particle capture efficiency, η_S, per bubble was estimated by trajectory analysis and the flotation efficiency, η_T, was calculated. The values of η_T calculated by the particle trajectory analysis were in reasonable agreement with those obtained experimentally. The dependence of particle diameter on η_T was also examined by the particle trajectory analysis.     

The bioassay of aflatoxins and related substances with Bacillus megaterium spores and chick embryos

The “paper disc plate” method of antibiotic assay usingBacillus megaterium spores was tested for the assay of aflatoxins and related compounds. Significant inhibitions were obtained in the range of 1–4 μg/disc for aflatoxin B₁ and 4–8 μg/disc for aflatoxin G₁. Dicumarol was the most active of the compounds tested and inhibited at 0.1–1.0 μg/disc. Compounds were also tested using nine-day-old chick embryos. It was found that embryos incubated in egg cartons were much more sensitive to toxins than eggs incubated on cotton padding or in a commercial egg incubator. The LD₁₀₀ of aflatoxin B₁ to carton-incubated embryos was 0.01 μg, while to embryos from the commercial incubator the LD₁₀₀ was >5.0 μg. The results of the two bioassay procedures did not correlate completely with each other. Presented at the AOCS-AACC joint meeting in Washington, D.C., 1968.     

Thermo-molecular gas-film lubrication (t-MGL) analysis for heat-assisted magnetic recording head sliders

In the present paper the static lubrication characteristics of a slider flying over a running boundary wall with arbitrary local temperature distributions are analyzed using the thermomolecular gas-film lubrication (t-MGL) equation. We obtain two approximate solutions: (a) a linearized solution when the temperature deviation is small ( \( \tau_{W} \ll 1 \) ) and arbitrarily distributed, and (b) a solution for the case with a very large bearing number \( (\varLambda \to \infty ) \) . We herein numerically calculate the static lubrication characteristics and verify the validities of these two approximate solutions. Moreover, we calculate the characteristics for various temperature distributions produced by laser heating.     

Relations between the molecular aggregation state and ionic conductivity in photopolymerized crosslinking polymers with oligo(oxyethylene) chains

A mixture of a vinyl monomer and a crosslinking agent was photopolymerized to form a crosslinked polymer film. Methacrylate with pendant oligo(oxyethylene) chain and poly(ethylene glycol) dimethacrylate were used as the vinyl monomer and crosslinking agent, respectively. The ionic conductivity of the film increased with an increasing concentration of LiClO₄ and then decreased. The size of the quasicrystalline aggregation phase composed of pendant and crosslinking chains in the film decreased with an increasing concentration of LiClO₄. The amorphous pendant and crosslinking oxyethylene chains gave rise to increased segmental motion and conductivity. The dissolution was depressed for a decrease in the ionic conductivity at a high LiClO₄ concentration at which the interactions among ions became stronger and the crystal phase of LiClO₄ was formed. The amount of the dissolution of the aggregation phase increased with an increasing crosslinking agent concentration. The quasicrystalline aggregation phase became larger with an increasing length of the pendant chains, and an increase in the size of the aggregation phase resulted in a decrease in the ionic conductivity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1272–1277, 2002     

Model-based Fault Localization: Finding Behavioral Outliers in Large-scale Computing Systems

We present a model-based approach to fault localization that aims to help the human analyst narrow down the manual localization into a small fraction of the overall system. Our method consists of two parts: pre-failure model derivation and post-failure model-based anomaly detection. The first part collects function-call traces from all processes and derives an execution model that reflects the function-calling behaviors of the target system. When a failure occurs, we identify the most deviant behaviors in the failed run by comparing the failure traces with the derived model. We claim that the analyst can substantially reduce the burden of fault localization by prioritizing such behaviors. Our preliminary experiment with a distributed job manager supports this claim: Our method narrows down localization of a 70-second faulty run on a 78-node distributed platform into just sub-second behaviors involving only two nodes.