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Efficient strengthening systems for tunnel lining concrete (TLC) have not been sufficiently discussed while various systems are available for other structures. The study aims at development of a strengthening system applicable for TLC. In particular, the present study focused on an NSM-FRP strengthening system which is often employed in deck-slabs and girders of bridge. Most of FRP materials used in such supra-structures are laminates and rods. It may be hard to embed FRP materials into inner surface of arched tunnels. Flexible FRP must be a favorable material for strengthening of TLC. The study focused on a carbon-fiber composite cable (CFCC) which is often used in prestressed concrete structures. The CFCC is embedded in inner surface of TLC by using a polymer cementitious mortar and epoxy resin. Fundamental loading test using mock-up TLC models was conducted to examine the strengthening effect of the proposed system. The paper reports the load-carrying capacity of the strengthened TLC models.

Vertical graphene (VG) films can be fabricated on the surface of nickel foil from fullerene soot (FS) under microwave plasma irradiation (MPI) in a mixture gas of H2 and Ar at 1200 W for 15 min. The resulting FS-derived VG films mostly consist of few-layer graphene sheets with large domain graphene sizes, high graphitization order, and high purity, as characterized by scanning and transmission electron microscopies, Raman spectroscopy, and X-ray photoelectron spectroscopy. Combined the present and previous results, MPI technique is an effective and versatile approach to synthesize vertically oriented graphene sheets from any carbon-containing sources.

The composites consisting of graphene oxides (GOs) and carbon spheres (CSs), which were hydrothermally derived from the aqueous solution of glucose with average diameter of 200 nm, were mechanically mixed, and the GOs/CSs (GCSs) were thermally treated at high temperatures in the range of 700–900 °C. In the GCS composites, the CSs as spacers located between the GO sheets prevent the aggregation and restacking of graphene sheets. The GCS composites (GO/CS = 1) treated at 800 °C (GCS@800) have the high specific capacitances of 272.8 and 197.5 F g−1 in a three-electrode cell at the current density of 0.2 and 10 A g−1, respectively, in 6 M KOH aqueous solution, and demonstrated high rate capability and good cycling stability. The excellent electrochemical performance of the GCS@800 electrode is attributed to its structure with hierarchical porous structures including overwhelming micropores and a few of macropores. This work provides an effective and simple technique by integrating CSs and graphene sheets into composite structures for high-performance energy storage devices.

Nitrogen-doped porous carbon monoliths (NDP-CMs) have long been pursued as the desirable supercapacitor electrode materials. However, the currently effective template methods and Lewis acid/base activation strategy suffer from the drawbacks of either high costs or tedious steps. We report on a simple and practicable novel method to the production of CNTs constructed NDP-CMs. Polyacrylonitrile (PAN) contained carbon nanotubes (CNTs), being dispersed into tubular level of dispersions (mono-dispersions), were used as the starting material and NDP-CMs were obtained through a direct carbonization process. First, PAN/CNT based mesostructured polymeric monoliths with interconnected networks were formed using a template-free temperature-induced phase separation (TTPS) method and the mono-dispersed CNTs networks act as the backbones of PAN molecules. Then, NDP-CMs with a surface area of 840 m2/g and a pore diameter 2.48 nm were obtained through heat treatment. Thus, the NDP-CMs based supercapacitor demonstrated a reversible specific capacitance of 246 F/g. Furthermore, pyridinic nitrogen and quaternary nitrogen species contribute significantly to the advantageous electrochemical activities of NDP-CMs.

Graphitization of carbon materials plays an important role their microstructures and conductivity, and then influences their applications. However, the graphitization of hydrothermal carbon spheres (CSs) has not systemically investigated heretofore. The CSs with 60–250 nm in diameter were prepared from aqueous glucose solution by hydrothermal carbonization, and were treated at the high temperatures of 900–2900 °C in Ar atmosphere. The heat-treated CSs have demonstrated that their surface structure, microstructure, porosity, and polygonization strongly depend on the treatment temperatures. These results are supported by scanning and transmission electron microscopes, energy dispersive x-ray spectrometry, Raman, X-ray diffraction, and BET surface area analyses. We also investigated the electrical properties of the heat-treated CSs under compression, and found that the resistivity of the carbon particles is very dependent on their surface, microstructure, density, and polygonization. Therefore, high temperature treatment is an effective method to tailor the structure, morphology, and property of the hydrothermal CSs.

Here, we present a facile technique for synthesis of graphene nanosheet (GNS)-grafted double-walled carbon nanotube (DWCNT) hybrid carbon nanostructures (here after referred to as G-DWCNTs) by directly growing GNSs along the sidewalls of DWCNTs using a two-step chemical vapor deposition (CVD). DWCNTs were synthesized by floating catalyst CVD at 1300 °C using ferrocene and thiophene dissolved in ethanol. Then, GNSs were grafted onto the synthesized DWCNT bundles by thermal CVD at 1300 °C using ethanol. The sharp-edged petal-like structure of GNSs were grown along the sidewalls of DWCNT bundles while maintaining the one-dimensional structure of DWCNT. Next, DWCNTs and G-DWCNTs were dispersed in ethanol, then deposited on the paper using vacuum filtration method and used for ethanol detection. G-DWCNTs sensor exhibited a 3-fold improvement in the response to ethanol vapor compared to the DWCNTs sensor. The sensing mechanism of DWCNTs and G-DWCNTs can be described in terms of charge transfer between the gas molecules and sensing material. These results demonstrate that the facile technique by two-step CVD method provides a promising approach for simple and low-cost technique to synthesize the hybrid nanostructure of GNSs and DWCNTs. The new hybrid carbon nanostructures are attractive for gas sensing application.

Due to its unique structure and amazing physiochemical properties including high chemical inertness, large specific surface area, and high electric conductivity, graphene, a two-dimensional single sheet of carbon atoms consisting of honeycomb lattices, has attracted great scientific interest in the enormous applications, for example, optical electronics, photovoltaic cells, energy storage, composite materials, filter membranes, and biological engineering, and is regarded as a basic building block for graphitic materials of all other dimensionalities. Recently, another two-dimensional graphitic sheet, vertical graphene (VG), which is typically aligned vertically on a substrate, is attractive for the abovementioned graphene-based applications. The novel vertical orientation and open structures of VGs make it more suitable for sensing biomarkers with high sensitivity and selectivity in complex biological conditions. Until now, VG biosensors have been investigated for detecting diverse biomolecules with or without the modification of metal nanoparticles. More importantly, the plasma technique for the growth and modification of VG is useful but simple tool to optimize the biosensor performance and capabilities. In this chapter, we will simply introduce the synthesis, characteristics, and fundamental properties of VG and carefully discuss the recent studies of VG-based biosensors including electronic and electrochemical biosensors.

Recently, graphene and carbon nanotube (CNT) composites have attracted great interest of scientists and exhibited fascinating properties even better than they could on their own. Here, we have synthesized the graphenated CNTs (g-CNTs), one of graphene–CNT composites, from waste rice husk (RH) by one-step microwave plasma irradiation (MPI) process. The RH-derived g-CNTs were composed of graphene standing on the sidewalls of CNTs, in which the graphene sheets possessed a large amount of sharp edges, which mainly consisted of 2–6 layers, and the CNTs had several tens of micrometers in length and 50–200 in diameter. They offer great promise in the application of electrochemical electrodes due to their special features including high surface area and specific capacitance. The successful MPI technique can be spread to other waste biomass, in which their components are made of cellulose, hemicellulose, and lignin similar to RHs, to fabricate high-added-value nanocarbons including graphene, CNTs, and g-CNTs, which were dependent of experimental pressure.

The electromagnetic wave absorption properties of single- and double-layer silver nanoparticle/carbon nanotube (Ag/CNT) nanocomposites were evaluated. The reflection loss (R.L.) of the samples was calculated based on the measured complex permittivity and permeability. The double-layer composites constructed from CNT 30 wt.% and Ag/CNT 30 wt.% with total thickness of 3.3 mm showed a minimum R.L. of ∼−52.9 dB (over 99.999% absorption) at 6.3 GHz. The bandwidth of reflection loss less than −10 dB was observed at 3 regions, with wideness of 3.5, 0.8, and 1.5 GHz. Thin absorber with large R.L. and wide response bandwidth at low and high frequency regions can be obtained with double-layer composites. The capability to modulate the absorption and bandwidth of these samples to suit various applications in different frequency bands indicates that these nanocomposites could be an excellent electromagnetic wave absorber.

Helical graphite whiskers (GWs) have been synthesized from fullerene waste soot, which is a byproduct in fullerene production by arc discharge technique, at 2600 °C for 1 h with Ar gas flow at 760 Torr. The as-synthesized GWs consisting of graphite layers with some disclination possess various kinds of morphological structures with loop-like brims and arch-shaped protrusion on their surfaces, as observed by scanning and transmission electron microscopy. The GWs show strong intensity of 2D peak in Raman spectra, which could be attributed to disclination in the whiskers.

Graphene-sheet fiber, a novel structure of graphitic carbon, grew from coffee grounds under the condition of microwave plasma irradiation. The resulting fiber consisted of only few-layer graphene without a hollow structure inside while possessing a large amount of graphene edges and high conductivity. Due to these advantages, graphene-sheet fibers may find applications in electrochemical energy conversion and storage.

Nitrogen-doped porous activated carbon monoliths (NDP-ACMs) have long been the most desirable materials for supercapacitors. Unique to the conventional template based Lewis acid/base activation methods, herein, we report on a simple yet practicable novel approach to production of the three-dimensional NDP-ACMs (3D-NDP-ACMs). Polyacrylonitrile (PAN) contained carbon nanotubes (CNTs), being pre-dispersed into a tubular level of dispersions, were used as the starting material and the 3D-NDP-ACMs were obtained via a template-free process. First, a continuous mesoporous PAN/CNT based 3D monolith was established by using a template-free temperature-induced phase separation (TTPS). Second, a nitrogen-doped 3D-ACM with a surface area of 613.8 m²/g and a pore volume 0.366 cm³/g was obtained. A typical supercapacitor with our 3D-NDP-ACMs as the functioning electrodes gave a specific capacitance stabilized at 216 F/g even after 3000 cycles, demonstrating the advantageous performance of the PAN/CNT based 3D-NDP-ACMs., National Science Foundation (U.S.) (DMR-1507806)

Vertically-aligned carbon nanosheets (CNSs), which were fabricated by microwave plasma-enhanced chemical vapor deposition in Ar and CH 4 system, have been annealed at high temperatures in the range of 1200–3000 °C. The morphologies and microstructures of the treated CNSs were analyzed by scanning and transmission electron microscopes, and Raman spectroscopy. High temperature treatment process efficiently removed the amorphous carbon and some defects and improved the graphitization of the CNSs. The graphitized grains increase and the interlayer spacing decreases with increasing heat temperatures. Heat treatment of the CNSs at temperatures from 1500 to 2000 °C was found to achieve the edges consisting of many single-layer graphene sheets. Annealing at temperatures above 2100 °C, the edges of nanosheets consist of 2–5 layer graphene with many zigzag junctions. The mechanism of reconstruction for the edges in the CNSs ascribes possibly to the carbon atom vaporization at high temperatures.

Graphite whiskers (GWs) are obtained from coffee grounds (CGs) treated at 2500 °C for 1 h in the presence of Ar gas at 1 atm. The majority of the GWs formed inside the CGs shell are rod‐like with a conical tip with diameter and length in the range between 1 to 3 µm and 4 to 10 µm, respectively. At first, the carbon layer might be grown in a turbostratic manner, and then progressively graphitized at higher temperature. The strong G′ peak intensity might be induced by the disclination of graphitized carbon layers.

We report the synthesis of high purity double-wall carbon nanotubes encapsulating GdCl 3 nanowires (GdCl 3 @DWCNTs). The obtained GdCl 3 @DWCNTs were characterized by transmission electron microscopy (TEM), Raman spectroscopy, UV–Vis-NIR spectroscopy, and fluorescence spectroscopy. TEM measurements show that GdCl 3 impurities were absent on the exterior of the tubes and bundles. Furthermore, significant changes of the optical properties of the inner tubes were not triggered by being filled with GdCl 3 nanowires, which suggests that significant charge transfer does not occur between the encapsulated GdCl 3 and the inner tubes. Our results indicate that GdCl 3 @DWCNTs could be useful for various applications using the expected magnetic properties of GdCl 3 and almost unchanged optical properties of DWCNTs. [TANSO 2013 (No. 260) 279–83.]

The quantitatively limited use of hydrogen peroxide in supercritical water allows for the in situ formation of iron oxides and graphitic carbon from ferrocene in one step. The structure of the particles prepared at 400–500 °C is comprised of nano- to micro-meter size of magnetite and maghemite cores covered with graphitic carbon shells. The morphology and size of the core–shell particles and the phase composition of iron-oxide cores are different dependent on the preparation conditions. The particles prepared at 400 °C contain, as dominant iron-oxide phase, the magnetite core particles ranging from nano- to micro-meter scales with no morphological regularity, while those prepared at 500 °C are comprised of hexagram shape and micro-meter size of maghemite cores. The observed morphology, the dimension of the core particles, and the dominant phase composition suggested that the iron-oxide cores would be formed through the oxidation of iron(II) to iron(III) and two different hydrolysis paths. Furthermore, the higher preparation temperature of 500 °C has shown a tendency to form smaller crystallite sizes of polycrystalline iron-oxide cores. The decrease of subcrystal sizes in the vicinity of superparamagnetic thresholds effects the reduction of coercivity in the ferromagnetic hysteresis.

pH monitoring data for public water bodies in Niigata and Gifu prefectures in central Japan were tested by the nonparametric seasonal Mann–Kendall method to evaluate long-term acidification. A significant long-term declining trend in river water pH was found in several watersheds in Niigata and Gifu prefectures. In Niigata, the declining trend was observed only in areas receiving drainage from granitic rocks, and the acid neutralizing capacity of the river waters was in fact low in those areas. In Gifu, a declining trend was observed in some remote watersheds, where there was no clear relationship between the geology and the long-term trends. Since Niigata and Gifu receive the highest level of acid loading from the atmosphere in Japan, river water acidification in several watersheds may be attributable to the effects of the acid deposition. Other factors, such as hot spring drainage, changes in land use, and natural sea salt deposition, cannot adequately explain the acidification phenomena observed in this study.

A limited use of hydrogen peroxide in supercritical water has produced graphitic carbons from hydrocarbons at the low temperature of 400 °C. The choice of precursor hydrocarbons leads to morphological and microstructural variations. The use of n-hexane has provided chain-like interlinked nanoparticles comprised of graphitic layers, while benzene has been converted to a fine spherical shape of colloidal carbons with sub-micron size. The microstructure of the colloidal carbons is comprised of smaller aromatic clusters than the hexane-derived graphitic layers. Furthermore, the graphitization of the colloidal carbons at 2300 °C has induced not closed shell-like graphitic layers with concentric arrangement but ribbon-like graphitic layers growing in no particular direction. The arbitrary direction of the graphitization demonstrates the smallness of the aromatic clusters allowing for their flexible rearrangement.

Article, JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS. 69(10): 2481-2486 (2008)

A simple construction of sol–gel sheaths onto the surface of multi-walled carbon nanotubes (MWCNTs) has been carried out in water by a hydrophobicity-induced covering with the assistance of ultrasound. The ultrasound assistance prevents in water an unregulated agglomeration induced by the hydrophobicity of MWCNTs and phenyl-containing sols, leading to a selective construction of sol–gel sheaths on the nanotube surface. The phenyl groups of the resulting sol–gel sheaths were successfully removed by air-oxidation to provide the MWCNTs covered with amorphous SiO 2 sheaths. The effect of the SiO 2 sheaths on the electrical and thermal properties of the SiO 2 -MWCNT nanocomposites was evaluated from the electrical resistivities of the nanocomposites with two different SiO 2 concentrations and the thermal conductivities of their phenol-resin composites. The results indicate that the small increase of the SiO 2 concentration remarkably increases the electrical resistivity of the SiO 2 -MWCNT nanocomposites. Furthermore, the SiO 2 sheaths have more directly influenced the thermal property of the polymer composites than the inside nanotubes.

Article, SCRIPTA MATERIALIA. 58(4): 267-270 (2008)

症例は86歳の女性で, 腹痛を主訴に外来受診し, 腹部単純X線検査にて腸閉塞と診断され入院となった. ガストログラフィン注腸検査ではS状結腸に高度の狭窄が見られ, 腹部造影CTで同部位に浮腫性変化による壁肥厚と憩室を認めたため, 憩室炎による腸閉塞と診断した. 大腸内視鏡は, 腸の屈曲が強く病変部まで挿入できなかった. 開腹するとS状結腸周囲は炎症が激しく, 強固に癒着していたが剥離可能であった. 口側の大腸は著しく拡張していたため大腸亜全摘を施行した. 切除標本の肉眼所見ではS状結腸は約6cmの壁肥厚を伴う狭窄が見られた. 病理組織学的所見では異型性のない大腸粘膜と, 筋層の肥厚, 著しい炎症細胞浸潤が認められ, 憩室による筋層の肥厚に, 浮腫性の変化が加わって狭窄がおきたと考えた. 悪性所見は認めなかった. 大腸憩室症の合併症は多彩であるが, 腸閉塞となり, 手術を要した症例の報告は少ないことから, 文献的考察を加えて報告する.

Nickel-fluorinated vapor growth carbon fiber (VGCF) composite films have been fabricated by using electrochemical deposition method from the plating bath containing a cationic fluorocarbon surfactant as the dispersing agent of fluorinated VGCF. The ESCA result confirmed the existence of metallic Ni and the fluorinated VGCF with C–F covalent bond structure in the composite film, while the SEM and TEM results showed that the fluorinated VGCFs embedded into the Ni-fluorinated VGCF composite film obtained from the plating bath at a dispersion concentration of 2.5 gdm−3 VGCF. The results clearly proved that the bath concentration and deposition conditions, which were designed in the present study, are effective on preparing the Ni-fluorinated VGCF composite film. Keywords: Nickel, Fluorinated vapor growth carbon fiber, Composite film, Electrochemical, Deposition, Microstructure

A valid biomarker for predicting the presence of gastric cancer may contribute to reducing deaths from this disease. Although pepsinogen (PG) testing has been introduced as a predictor, its predictive power is not satisfactory. We examined whether serum trefoil factor (TFF) could be a non-endoscopic predictor of the presence of gastric cancer.Gastric cancer patients who underwent preoperative endoscopy were sequentially recruited. Individuals who underwent a thorough medical checkup were enrolled as non-cancer controls. Serum levels of TFF1, TFF2, TFF3, Helicobacter pylori antibody, PG I, and PG II were examined.We studied 192 gastric cancer patients aged 64.3 ± 9.7 years and 1254 non-cancer controls aged 52.3 ± 12.4 years. In the age/gender-matched analysis (187 cases and 561 controls), significant relationships were demonstrated between gastric cancer presence and TFF3 (P0.0001), the PGI/II ratio (P0.0001), H. pylori antibody (P = 0.001), TFF1 (P = 0.012), and TFF2 (P = 0.020). The area under the receiver-operating characteristic curve for predicting gastric cancer presence was comparably high for all factors (0.893) and for the combination of TFF3 and the PG test (0.883), but was significantly (P0.0001) lower for the PG test alone (0.823). A positive PG test showed a sensitivity of 67% and specificity of 82%, whereas a combination of TFF3 and PG testing showed a sensitivity of 80% and specificity of 80% in predicting the presence of gastric cancer.The combination of serum TFF3 and PG testing might be a valid non-endoscopic biomarker for predicting the presence of gastric cancer.

This report describes a pregnant woman with common bile duct stones whose colic was successfully treated by prolonged continuous epidural infusion of ropivacaine. A 32-year-old woman in the 26th week pregnancy complained of severe abdominal pain due to common bile duct stones. We adopted ropivacaine for infusion into the epidural space using patient controlled analgesia system considering fetoplacental circulation. We administered the solution successfully for 3 weeks, but we observed that the effectiveness of ropivacaine became reduced. This suggests that tachyphilaxis to ropivacaine might have developed by its long-term infusion.

We fabricated silver–carbon nanotube (Ag–CNT) composite plating films and prepared samples after a H2S gas corrosion test. After corrosion, although the elastic modulus of Ag film increased 1.9 times, there was no marked difference in the mechanical characteristic of Ag–CNT film. At a low load, for the Ag–CNT film after corrosion, there was no polarity and the contact resistance was low and ohmic, although the contact resistance of Ag film after corrosion was high and polar. Therefore, Ag–CNT film can be considered as a promising material for next-generation electrical contact applications.

tissues was significantly higher than that in the adjacent normal tissue (73.3% vs 13.3%, P 0.05). 5. Multivariate analysis confirmed that the dual-high expression of SUMO-1 and P53 was an independent factor for predictors of progression risk. Conclusion: There was a high SUMO1 expression in colon cancer tissues. High expression of P53 in colon cancer may be related to SUMO Modification. SUMO1 may be useful as a novel target for therapy in colon cancer as well as a clinical indicator for tumor progression risk.

A high dispersion of carbon-supported Pt–Ru alloy nanoparticles have been prepared in an alkaline aqueous solution by using glyoxylate as a reducing agent. The glyoxylate monoanion is converted to oxalate dianion with the reduction of metal precursor ions. The surface-potential analysis of unsupported Pt–Ru black in the presence of all the anion species coexistent in the preparation system suggests a possibility of oxalate dianion as the most effective particle stabilizer. In the glyoxylate-reduction system, a precursor–support interaction is significantly promoted to affect the formation and stabilization of nanoparticles. The glyoxylate reduction at 20-wt% metal loading has provided a higher Pt(0)/Ru concentration ratio in the near-surface region than that of 60-wt% catalyst. The structural and morphological features and advantageous surface composition of the 20-wt% catalyst contribute to the high mass activity for methanol oxidation in the anode overpotential range of typical direct methanol fuel cells.

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in APPLIED PHYSICS LETTERS. 92(6):63105 (2008) and may be found at https://doi.org/10.1063/1.2842411 ., Article, APPLIED PHYSICS LETTERS. 92(6):63105 (2008)

Free-standing diamond films are prepared by CVD technique to examine their properties directly. The products have a variety of shapes such as plates, tubes and curved diaphragms. Coefficients of thermal expansion (GTE) of the tube are similar to the values of a bulk diamond in the range from 40°C to 500°C. It is found that polished diamond film has uniform infrared transmission ranging from 500cm-1 to 4000cm-1. A speaker diaphragm will be a good application for free-standing diamond film.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.