Selective synthesis of carbon nanotubes and nanocapsules using naphthalene pyrolysis assisted with ferrocene

Selective synthesis of well aligned multi-walled carbon nanotubes (MW-CNT) and multi-shelled carbon nanocapsule (MS-CNC) using pyrolysis of naphthalene with the presence of ferrocene was experimentally examined. With higher mole fraction of naphthalene to ferrocene, more MW-CNTs could be synthesized due to higher concentration of carbonaceous precursors emerging from the decomposed naphthalene. Based on kinetic analysis, at lower temperature, MW-CNTs could preferably be synthesized due to the controlled supply of carbonaceous clusters to get onto the surface of Fe clusters. On the other hand, at temperature higher than 900 °C the Fe clusters become more active to catalyze carbonaceous precursors to undergo self assembling process of MS-CNCs. With cheaper cost of naphthalene compared with other high-value hydrocarbons, usage of naphthalene would provide an advantage of reasonably economical synthesis of MW-CNT or MS-CNC.     

Voltage-based fault path tracing by transistor operating point analysis

A novel diagnosis technology based on transistor operating point analysis is presented. This technology is the way to detect penetration current net result from fault, replace the net with impedance net, calculate voltage value of each node of the impedance net by OHM’s low, and then sequentially trace the fault logic propagation. The impedance is determined by using transistor dimension and its operating point managed by gate voltage. The proposed method makes it possible to detect not only signal propagation of each gate in order of time, but oscillation phenomenon brought by feedback fault.     

Determination of traction-separation laws on an acrylic adhesive under shear and tensile loading

Structural acrylic adhesives are of special interest because those adhesives are cured at room temperature and can be bonded to oily substrates. To use those adhesives widely for structural bonding, it is necessary to clarify the methodology for predicting strengths of bonding structures with those adhesives. Recently, cohesive zone models (CZMs) have been receiving intensive attentions for simulation of fracture strengths of adhesive joints, especially when bonded with ductile adhesives. The traction-separation laws under mode I and mode II loadings require to estimate fracture toughness of adhesively bonded joints. In this paper, the traction-separation laws of an acrylic adhesive in mode I and mode II were directly obtained from experiments using Arcan type adhesively bonded specimens. The traction-separation laws were determined by simultaneously recording the J-integral and the opening displacements in the directions normal and tangential to the adhesive layer, respectively.     

Abscopal Effect of Frozen Autograft Reconstruction Combined with an Immune Checkpoint Inhibitor Analyzed Using a Metastatic Bone Tumor Model

We evaluated the abscopal effect of re-implantation of liquid nitrogen-treated tumor-bearing bone grafts and the synergistic effect of anti-PD-1 (programmed death-1) therapy using a bone metastasis model, created by injecting MMT-060562 cells into the bilateral tibiae of 6–8-week-old female C3H mice. After 2 weeks, the lateral tumors were treated by excision, cryotreatment using liquid nitrogen, excision with anti-PD-1 treatment, and cryotreatment with anti-PD-1 treatment. Anti-mouse PD-1 4H2 was injected on days 1, 6, 12, and 18 post-treatment. The mice were euthanized after 3 weeks; the abscopal effect was evaluated by focusing on growth inhibition of the abscopal tumor. The re-implantation of frozen autografts significantly inhibited the growth of the remaining abscopal tumors. However, a more potent abscopal effect was observed in the anti-PD-1 antibody group. The number of CD8+ T cells infiltrating the abscopal tumor and tumor-specific interferon-γ (IFN-γ)-producing spleen cells increased in the liquid nitrogen-treated group compared with those in the excision group, with no significant difference. The number was significantly higher in the anti-PD-1 antibody-treated group than in the non-treated group. Overall, re-implantation of tumor-bearing frozen autograft has an abscopal effect on abscopal tumor growth, although re-implantation of liquid nitrogen-treated bone grafts did not induce a strong T-cell response or tumor-suppressive effect.     

Posture Control for Personal Mobility Robot Using Feedback Compensation with Unstable Pole

This paper presents a novel posture control approach using feedback compensation with an unstable pole. For a narrow and small personal mobility robot (PMR), this is needed in order to control its posture for achieving quick turning and high acceleration. However, in the conventional control approach that uses the posture angle as a controlled variable, the zero moment point (ZMP) does not settle to the desired point in the following cases: an unknown disturbance force given to the PMR, a fluctuation in the center of gravity of the PMR, and a change in the conditions between the tires and the road surface. In this paper, a novel control method using feedback compensation with an unstable pole is proposed to achieve the desired ZMP in the steady state. The proposed controller changes the control input for the actuator of posture control to zero in order to achieve the desired posture angle. The effectiveness of the proposed approach is verified through experiments using a prototype of the PMR.     

Real-Time Amplitude and Phase Imaging of Optically Opaque Objects by Combining Full-Field Off-Axis Terahertz Digital Holography with Angular Spectrum Reconstruction

Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials.     

Analysis of a coal-derived liquid using highpressure liquid chromatography and synchronous fluorescence spectrometry

Synchronous fluorescence spectra of model polycondensed aromatic hydrocarbon molecules were recorded and used to identify the number of condensed rings in the aromatic molecules. A coal-derived liquid from Yubarishinko coal was initially separated into fractions having different number of condensed aromatic rings, and each fraction was further divided into narrow fractions having different numbers of carbon atoms. These fractions were studied using synchronous fluorescence spectroscopy. Results indicate the potential usefulness of synchronous fluorescence spectroscopy as a method of analysis of complex mixtures as coal-derived liquids despite the limitation of the method that some molecules give only weak peaks. Several components in some fractions were identified by a combination of synchronous fluorescence spectra and conventional excitation and emission fluorescence spectra.     

Control of biodegradability of poly(3‐hydroxybutyric acid) film with grafting acrylic acid and thermal remolding

Radiation‐induced graft polymerization of acrylic acid (AAc) on poly(3‐hydroxybutyric acid) (PHB) film was carried out and the resulting film was thermally‐remolded. The PHB films grafted with AAc (PHB‐g‐AAc) having a degree of grafting higher than 5% completely lost the enzymatic degradability. The enzymatic degradability of the grafted film was recovered by thermal remolding. The highest enzymatic degradation rate was observed at degree of grafting of 10% after thermal remolding. The PHB‐g‐AAc films and thermally‐remolded PHB‐g‐AAc films were characterized by contact angle and differential scanning calorimetry. The enzymatic degradability of PHB‐g‐AAc films was lost by the grafted AAc, which covered the surface of PHB film. The acceleration of enzymatic degradation in the remolded PHB‐g‐AAc films was mainly caused by decrease of crystallinity of PHB by dispread of grafted AAc during thermal remolding. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3856–3861, 2006     

Enhanced amination and adsorption performance of functional copolymer synthesized <Emphasis Type="Italic">via</Emphasis> RAFT-mediated radiation grafting in emulsion

Grafted polymer substrates bearing diglycol amic acid (DA) ligands for Eu and Sm adsorption were prepared using a two-step post-grafting modification of polyethylene/polypropylene-g-poly(glycidyl methacrylate) (PE/PP-g-PGMA) that was synthesized through reversible addition-fragmentation chain transfer (RAFT)-mediated γ-radiation induced graft polymerization in emulsion phase. The PE/PP-g-PGMA prepared with RAFT mediation exhibited better reactivity towards amination reaction at 40 °C than the graft copolymers prepared without RAFT mediation, with the epoxide to amino group conversion of the former exceeding the latter by as much as 20%. The DA ligands were incorporated to the aminated graft copolymer by subsequent reaction with diglycolic anhydride to yield the DA-modified PE/PP-g-PGMA adsorbent. The effects of pH and competing ions on the uptake of Eu and Sm have been investigated. The DA-modified PE/PP-g-PGMA prepared with RAFT mediation showed higher Eu and Sm adsorption percentage than the DA adsorbent that was synthesized without RAFT mediation. The DA-modified PE/PP-g-PGMA exhibited higher affinity for Eu over Cu and Fe in acidic solutions.     

RAFT‐mediated graft polymerization of glycidyl methacrylate in emulsion from polyethylene/polypropylene initiated with γ‐radiation

The successful reversible addition‐fragmentation (RAFT)‐mediated graft polymerization of glycidyl methacrylate (GMA) in emulsion phase from polyethylene/polypropylene nonwoven fabric using 4‐cyano‐4‐[(phenylcarbonothioyl)thio]pentanoic acid under γ‐irradiation at ambient condition is reported. While conventional graft polymerization in emulsion phase yielded grafted materials with low of grafting (Dg) values [<7.5% at 10% (wt/wt) GMA], addition of RAFT agent to the graft polymerization system allowed the synthesis of polyethylene/polypropylene‐g‐poly(GMA) with more tunable Dg (8% ≤ Dg ≤ 94%) by controlling the grafting parameters. Relatively good control (PDI ～1.2 for selected grafting conditions) during polymerization was attained at 100:1 monomer‐to‐RAFT agent molar ratio. The number average molecular weight of free poly(glycidyl methacrylate) (PGMA) increased as a function of monomer conversion. NMR analyses of the free PGMA homopolymers indicate the presence of dithiobenzoate group from 4‐cyano‐4‐((phenylcarbonothioyl)thio) pentanoic acid on the polymer chain. The reactive pendant oxirane group of the grafted GMA can be modified for various environmental and industrial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45270.