Demolition work is a work of the first of the construction work, we investigated a method of reducing greenhouse gas emissions from the demolition work. It was investigated by visualization to five items of three buildings.
Titanium-based functional thin films were prepared by a sputtering deposition method using a metal powder target. To determine the deposition mechanism of the resulting TiO2 thin films, the electron density and temperature of the processing plasma were investigated. The deposition rate using powder targets was 3-5 times higher than that using bulk targets. The reasons for the increased deposition rate were considered as follows. The net surface area of a powder target is twice that of a bulk target. The gamma value for ions at slanting incidence to the target surface is higher than that for perpendicular incidence. The surface temperature of the powder target was higher than that of the bulk target. The hollow cathode effect may be implicated in the case of powder targets.
Zinc oxide (ZnO) nanowires with high aspect ratio were successfully synthesized by annealing the Zn films in the air prepared by electron beam evaporation. The diameter and the length of nanowires are 500 - 100 nm and 5 - 10μm, respectively. Transmission electron microscopy analysis showed that ZnO nanowire is highly crystalline in nature. The experimental results were explained by vapor-solid growth model.
To evaluate spent mushroom beds (log and sawdust beds) as a two-step gasification resource, carbonization of spent mushroom beds for the production of char and gasification of the chars were performed using a small laboratory system. Carbonization of the mushroom beds at 600 °C produced suitable chars as the source for steam gasification. In addition, the wood gas produced during the carbonization process had a sufficient higher heating value and thus could be used as the fuel for the gasification step. The gasification of the spent bed chars produced clean hydrogen-rich gases without generation of any by-products. On the other hand, direct gasification of a waste log bed generated hydrocarbon and tar-like materials. Furthermore, the water-gas reaction (C + H2O → CO + H2) was proposed as the mechanism for the gasification process.
Titanium oxide thin films were prepared by a pulsed laser deposition method using Ti and TiO2 powder and bulk targets. The deposition rate when using a powder target was higher than that in the case of a bulk target. These results may be caused as follows. The heat absorptivity of a powder target for the 532 nm laser light is higher than that of a bulk target. In addition, the net-ablation area of the powder target is larger than that of the bulk target. X-ray diffraction measurements suggest that the films prepared using the Ti and TiO2 powder target without substrate heating system are titanium oxide (TiOx : x=0～2). The diffraction patterns of the prepared films using powder targets indicated nearly the same properties as those of films prepared using Ti and TiO2 bulk targets. The results may be due to the target surface oxidation by laser ablation on the target surface.
We find that the amount of J-aggregates forming through light-induced J-aggregation in mixed LB films of SP1822 and matrix molecules depends on the spatial arrangement of the matrix with respect to SP1822. In mixed Langmuir films of SP1822 and arachidic acid (H19A), each component has a constant occupied area on water irrespective of mixing ratio. H19A is positioned beside SP1822, allowing for the J-aggregation of MC1822 (merocyanine form of SP1822). In mixed Langmuir films of SP1822 and octadecylamine (ODA), area per SP1822 is almost constant at mixing ratios of 1:0, 1:1 and 1:2. ODA is positioned on top of the hydrophilic moiety of SP1822 and should have strong intermolecular interaction with SP1822, hindering the J-aggregation of MC1822.
Doping with manganese is one of several ways to confine the electrons to a small region. In Mn-doped BaTiO3 the phenomenon, which suggests reconstruction of ferroelectric domains, such as an aging effect, has been observed. The valence state of the substituted Mn was found to be +4 by using X-ray absorption fine structure measurements. We also performed high-energy synchrotron X-ray measurements and revealed that the coherence length of local structure increased with Mn substitution. This is a kind of phase transformation from a short-range order to long-range order type of ferroelectrics.
C2(a3Πu) radicals were produced using the dissociative excitation reaction of C2H2 with the microwave discharge flow of Ar. The mechanism of the production of these radicals was investigated by a combined analysis of the laser-induced fluorescence spectroscopy of the C2(d3Πg-a3Πu) (Swan band) and Ar(3P1-3P0) transitions and the electrostatic-probe measurements. From the dependences of these LIF intensities and the kinetic-energy distribution of free electrons on the pressure of Ar, it was concluded that the mechanism of the production of C2(a3Πu) was the collisional energy transfer from the metastable state of Ar, Ar(3P0,2). This conclusion was supported by a chemical-kinetic analysis.
The electronic structure of Yb3+-doped BaPrO3 (BaPr1-xYbxO3-δ) has been studied by resonant photoemission spectroscopy and X-ray absorption spectroscopy (XAS). The O 1s XAS spectra exhibit that the conduction band consists of Pr 4f and Ba 5d states. The valence band is mainly composed of the O 2p states hybridized with Pr 4f and Pr 5d states. The valence band shifts to the lower binding energy side with Yb3+ concentration. The Pr 4f state has the mixed-valent states of Pr4+ and Pr3+. The intensities of Pr4+ and Pr3+ states rapidly decrease with increasing Yb3+ concentration. These results may contribute to the change of charge transfer from O 2p to Pr 4f states in the ground state with oxygen vacancies and Yb3+ substitution.
Nd-doped BiFeO3 (BNF) thin film of 170 nm thickness was deposited on SrRuO3-coated (100) Nb-doped SrTiO3 substrate by pulsed laser deposition. Resistive switching and ferroelectric properties of BNF film capacitor were investigated by using Positive-Up-Negative-Down measurement. Switched charge without influence of the leakage current was 121 μC/cm2 with a maximum applied voltage of 9 V. The leakage current was estimated from the gradient of the pulse response when reading pulse was applied. After writing by voltages of -9 V and +9 V the current density at reading voltage of -1.8 V were 1.2 mA/cm2 and 14 μA/cm2, respectively. Maximum ON/OFF ratio of the leakage current was 86.
Hot-filament chemical vapor deposition exhibits high potential for scaled-up diamond growth. However, contamination from filament materials may adversely affect diamond quality. In this study, we investigated the effects of off-axis (100) planes on impurity incorporation. Tungsten atoms at concentration levels of 1018 cm-3 were unintentionally incorporated as impurities from filament wires used; this was confirmed by secondary ion mass spectroscopy. The incorporated amount did not depend on the off-axis angle of substrate, which ranged from 0 to 5°. The incorporation mechanism is discussed on the basis of the obtained experimental results. It is suggested that tungsten atoms are incorporated preferentially at facet faces rather than at step edges.
Alkoxide-derived lanthanum aluminate (LaAlO3: LAO) nanoparticles were obtained at 1023 K. Experimental process parameters such as the starting reagents and the process temperature were optimized to obtain LAO with a large surface area. Consequently, LAO with 29 m2/g was attained at 1073 K. This surface area was approximately twice that of the conventional chemical solution deposition using polymerized complex method. The catalytic activity for the ethanol steam reforming process of the obtained LAO was estimated using a conventional fixed bed reactor. Results show that the highest hydrogen yield of approximately 40% was attained using alkoxide-derived LAO. The catalytic activity was higher than that of LAO derived from the conventional preparation technique.
Oleic acid coated Fe3-xCoxO4 (x = 0, 0.1 and 0.3) nanocrystal self-assembled films were fabricated via drop-casting of colloidal particles on a SiO2/Si substrate. Nanocrystals of the Fe3-xCoxO4 exhibited bifurcation of the zero-field-cooled and field-cooled magnetizations at 300 K. The Fe3-xCoxO4 nanocrystal drop-cast films demonstrated nonlinear current-voltage characteristics between the source and drain electrodes in magnetic fields of zero and 0.2 T, and magnetoresistance reached into −46% for the x = 0 film and −50% for both the x = 0.1 and 0.3 films at 300 K. Oleic acid coated Fe3-xCoxO4 (x = 0.1 and 0.3) nanocrystal would boost developments of a high performance current switching device using negative magnetoresistance.
Hydrogel multilayers with micrometer-scale in thickness containing living cancer cells were prepared by layer-by-layer assembling with 2-methacryloyloxyethyl phosphorylcholine polymer solution and poly(vinyl alcohol) solution alternatively under biological conditions. It was demonstrated that this tool could be utilized for minimizing barriers to the diffusion of drugs while preserving the 3D context. The contribution of dimensional and diffusional factors on drug efficacy was also investigated. As a case study, the cytotoxicity effects of paclitaxel on human cervical cancer HeLa-Fucci cells were evaluated in vitro. A comparative study was carried out: 2D culture, 3D culture in microgel thin membrane and in macrogel. Time-lapse microscopic analyses showed HeLa-Fucci cells cultured on 2D exhibited a more rapid and robust response to stimulation than cells cultured in microgel thin membrane. Besides, HeLa-Fucci cells cultured under macrogel did not show any response to stimulation. It was speculated that both of the diffusion of paclitaxel and matrix dimensionality could affect drug efficacy and diffusion of drug seemed to play a more important role. This study provides a versatile and experimentally convenient method to fabricate a useful and generalizable platform for cancer drug screening.
The samples had been heated by magnetic or electric field of microwave. During microwave heating by magnetic field, the samples were heated to the sintering temperature of 1000°C for 12 min followed by 70 min soak time. In initial heating step during the first 30 min, the sample temperature was dramatically changed. Thereafter, the sample temperatures settled and microwave power was lowered as 270 watt. In case of electric field heating of microwave, the samples were heated to the sintering temperature of 1000°C for 2 min followed by 100 min soak time. The heating mechanism was electric loss, because the heating rate was not correlative with Curie temperature. As a result, the microstructures were very different in sintered samples obtained by magnetic field and electric field heating under microwave irradiation. The sample heated in the magnetic field exhibited the presence of randomly oriented nano-crystalline domains. The domain sizes of this sample were approximately 10 nm in average. On the other hands, the sintered sample in electric field showed rather large grain growth.
Hydrogen response characteristics of Pt/Ti film were evaluated by impedance measurement. The sensitivity of Pt/Ti film as a function of hydrogen concentration was measured by DC resistance. According to decrements of thickness, the resistivity change ratio increased. However, the response time to hydrogen gas was insufficient at room temperature, and therefore, pulsed heating was conducted to speed up the response time with low power consumption. The effect of these results of thickness dependence and the pulsed heating suggests the hydrogen response mechanism is based on the surface reaction. Therefore, AC impedance measurement was conducted to analyze the conduction mechanism of ultrathin film. As a result, Pt/Ti film is assumed to be a parallel RC circuit due to the surface roughness. In addition, both resistance and capacitance were changed and frequency dependence was observed, when exposed to hydrogen, by the AC impedance measurement. From the result of measurement and calculation, the capacitance changes occurred in high frequency by the skin effect. The carrier and proton generated by the catalytic reaction of hydrogen were thought to exist near the surface.
In this study, we studied the structure and phase behavior of synthetic ceramide 2 ((2S,3R)-2-Octadecanoylamino-octadecane-1,3-diol) (S-CER2) using differential scanning calorimetry (DSC) and X-ray diffraction. In addition, we also investigated the effects of limonene on S-CER2. It was found that the phase behavior of S-CER2 depends on its thermal history and that the DSC thermograms depend apparently on the scan rates. The present study suggested a relatively strong affinity between limonene and S-CER2.
A novel heterogeneous transition-metal catalyst, a polymer-supported terpyridine-palladium(II) complex, was prepared from 4-methoxycarbonylbenzaldehyde, 2-acetylpyridine, NH4OAc according to the reported procedures and found to promote the Mizoroki-Heck reaction in water between aryl halides and styrenes under aerobic conditions with high to excellent yield. The catalyst was recovered and reused several times without loss of catalytic activity.
In this study, we investigated control of particle size of hollow silica-alumina composite spheres prepared using L(+)-arginine and their activity of these hollow spheres for hydrolytic dehydrogenation of ammonia borane. The hollow spheres were prepared by polystyrene templates method, and the polystyrene templates were completely removed by calcination. In this method, silica-alumina composite shell were coated onto polystyrene particles via a sol-gel reaction using L(+)-arginine as a promoter of this reaction. Hollow spheres with average diameter of 206, 277, and 366 nm were prepared using polystyrene particles with average diameter of 150, 200, and 340 nm, respectively. Activities of hollow spheres with various diameter for hydrolytic dehydrogenation of ammonia borane were compared. The evolution of 8, 7.5, and 5 mL of hydrogen was released in the presence of the hollow spheres with the diameter of 210, 260, and 400 nm, respectively. From the results, the activity increase with decrease of diameter of the hollow spheres. The result of neutralization titration and solid state 27Al MAS NMR indicates that the activity for hydrolytic dehydrogenation of ammonia borane increase with increase of amount of Brønsted acid sites.