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排序方式: 共有1398条查询结果,搜索用时 218 毫秒
961.
Hideki Kita Hideki Hyuga Naoki Kondo Tatsuki Ohji 《International Journal of Applied Ceramic Technology》2008,5(4):373-381
Exergy is a measure that can commonly deal with the quantification of a variety of resources, products, and energy coming in and going out of the manufacturing systems. In this study, exergy analysis was conducted on a ceramic tube and a steel heater protection tube used in aluminum casting, and the amount of exergies consumed through their life cycle were calculated. In the production stage, the ceramic heater tube consumes much higher exergy than the steel one; however, analysis through the life cycle in seven years shows that exergy consumptions for the ceramic and steel tubes were 1223 and 1585 GJ, respectively. These results reveal that ceramics are effective in the reduction of environmental burden. 相似文献
962.
Hideyuki Kasano Teruhiko Yoda Kuniei Nogami Jun Murakoshi Naoki Toyama Mamoru Sawada Kentaro Arimura Lu Guo 《钢结构国际杂志》2012,12(3):381-389
Tension and shear block failure is a limit state which occurs in the connection of tension steel members. The failure mechanism is a combination of tensile failure on one plane and shear failure on the perpendicular plane. The design strength equations for the tension and shear block failure are described in the well known design codes. However, they provide inconsistent levels of safety when they are used in different types of connections. In this paper, the authors survey the design strength equations in the various codes. Then, the pertinent strength equations for the gusset plates of steel truss bridges are selected. Moreover, the authors propose a pair of strength equations for compression and shear block failure for gusset plates subjected to compressive force. And to examine the applicability of proposed equations and to investigate the mechanical behavior of compression gusset plates, parametric analyses on the various thicknesses of gusset plates were conducted. 相似文献
963.
Since colors affect human beings both physiologically and mentally, various studies have been conducted about the infl uences
of color. Most of the studies have been focused on the psychological aspects. In this study, we investigated the infl uences
of color physiologically by the use of infrared thermography. With this technique, the subjects wear no devices, and objective
values are expected to be obtained to evaluate the infl uences of color. Nasal skin temperatures were measured by infrared
thermography under yellow, red, and blue illuminations. A significant temperature change was observed under red illumination. 相似文献
964.
965.
Tohru Ohki Naoki Nishikawa Takayuki Hasegawa Tomomichi Okano Yoshiaki Tanizawa 《Journal of surfactants and detergents》2010,13(1):19-26
Repeated use of a toilet results in the build-up of a deposit derived from urine and hard water on the surface of the toilet
bowl. The hardened mineral scale is difficult to clean completely, especially in the case of deposits under the rim. A number
of studies have focused on kidney stones, which are also caused by urine in the urinary tract; little attention, however,
has been paid to the detailed composition and structure of the toilet scale. To develop powerful products for removing the
toilet scale effectively instead of relying on acid-cleaning and scrubbing, the composition and the accumulation mechanism
of the scale must be clarified. Scale samples collected from the bowl surface were characterized by IR, XRF, XRD, ICP–AES,
SEM–EDS and HPLC techniques and found to consist mainly of calcium phosphates, struvite, calcium carbonate, uric acid and
proteins. After acid treatment of the scale, a film-like structure of protein, produced as a result of the metabolism of bacteria
and mold, was left behind. The scale had composite structures that were composed of the inorganic minerals and the organic
materials listed above. This structure might be critical to making the scale resistant to removal by acid-containing cleaners. 相似文献
966.
Mikinori Hotta Naoki Kondo Hideki Kita Tatsuki Ohji Yasuhisa Izutsu 《International Journal of Applied Ceramic Technology》2014,11(1):164-171
This study demonstrated that a long silicon nitride pipe of several meters with adequately strong joints can be fabricated by a local‐heating joining technique. Commercially available silicon nitride ceramic pipes sintered with Y2O3 and Al2O3 additives were used for parent material, and powder slurry of Si3N4‐Y2O3‐Al2O3‐SiO2 system was brush‐coated on the rough or uneven end faces of the pipes. Joining was carried out by locally heating the joint region at different temperatures from 1500°C to 1650°C for 1 h with a mechanical pressure of 5 MPa in N2 flow; using a horizontal electrical furnace specially designed for this experiment. The silicon nitride pipe 3‐m long was successfully fabricated without voids or cracks in the joint region, and the microstructure of the joint region was similar to that of the parent one. The joint strength was examined in flexure using specimens cut from the joined pipes, and those joined at 1600°C and 1650°C indicated the highest strength of about 680 MPa, which was almost the same as that of the parent material. This study also indicated that the slurry brush‐coating technique is advantageous to easily joining ceramic pipes with rough or uneven end faces, which is essentially important for practical use. 相似文献
967.
Toru Wakimoto Yoshimitsu Takahashi Norihito Kimura Yukitoshi Narumi Naoki Hayakawa 《Electrical Engineering in Japan》2014,186(4):11-19
This paper presents a plain method of calculating the voltage waveform at motor input terminals from the inverter output terminal voltage and also a method of reducing the voltage. The voltage waveform at the motor input terminals is obtained by a frequency domain calculation using the transfer function of the cable and the frequency characteristics of the voltage waveform at the inverter output terminals. The analysis using this method clarifies the mechanism of the rise of the maximum voltage at the motor input terminals, that is, ringing at the motor input terminals, which occurs at specific frequencies at which the transfer gain increases, causing the rise of the maximum voltage. Therefore, to decrease the maximum voltage at the motor input terminals, it is effective to shorten the cable length or cancel the ringing voltage by preswitching. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 11–19, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22482 相似文献
968.
Naoki Kano ;Kunlhlro Tanabe ;Meiling Pang ;Yanling Deng ;Hiroshi Imaizumi 《化学与化工:英文版》2014,(11):1049-1058
Adsorption experiment from aqueous solutions containing known amount of Cr (chromium) using chitosan was explored to evaluate the efficiency of chitosan as sorbent for Cr. Some variable parameters such as pH, reaction time and chitosan dosage were optimized. Under the optimum experiment condition, the effect of common ions on the adsorption of Cr (i.e., Na^+, K^+, Mg^2+, Ca^2+ for Cr(Ⅲ), and Cl^-, NO3^-, SO4^2- for Cr(Ⅵ)) was also investigated. Furthermore, the sorption mechanism of Cr by chitosan was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, to confirm the characteristics of the chitosan, the surface morphology of the biomass was determined by SEM (scanning electron microscope) and specific surface area analyzer (N2-BET (Brunaeur, Emmet and Teller)). Consequently, the following matters have been mainly clarified: (1) chitosan can be an efficient sorbent for Cr (both Cr(Ⅲ) and Cr(Ⅵ)); (2) the effect of common ions on the adsorption ofCr (Cr(Ⅲ) and Cr(Ⅵ)) was not significant under this experimental conditions; (3) adsorption isotherms using the chitosan can be generally described by Langmuir isotherm more satisfactorily for Cr. The adsorption may have occurred mainly by monolayer reaction; (4) the rates of adsorption were found to conform to pseudo-second order kinetics. 相似文献
969.
Naoki Kimata Angelo Karaboyas Brian A. Bieber Ronald L. Pisoni Hal Morgenstern Brenda W. Gillespie Akira Saito Tadao Akizawa Shunichi Fukuhara Bruce M. Robinson Friedrich K. Port Takashi Akiba 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(3):596-606
Guidelines have recommended single pool Kt/V > 1.2 as the minimum dose for chronic hemodialysis (HD) patients on thrice weekly HD. The Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown that “low Kt/V” (<1.2) is more prevalent in Japan than many other countries, though survival is longer in Japan. We examined trends in low Kt/V, dialysis practices associated with low Kt/V, and associations between Kt/V and mortality overall and by gender in Japanese dialysis patients. We analyzed 5784 HD patients from Japan DOPPS (1999–2011), restricted to patients dialyzing for >1 year and receiving thrice weekly dialysis. Logistic regression models estimated the relationships of patient characteristics with Kt/V. Logistic models also were used to estimate the proportion of low Kt/V cases attributable to various treatment practices. Multivariable Cox regression was used to estimate the associations of low Kt/V, blood flow rate (BFR), and treatment time (TT), with all‐cause mortality. From 1999 to 2009, the prevalence of low Kt/V declined in men (37–27%) and women (15–10%). BFR <200 mL/min, TT <240 minutes, and dialyzate flow rate (DFR) < 500 mL/min were common (35, 13, and 19% of patients, respectively) and strongly associated with low Kt/V. Fifteen percent of low Kt/V cases were attributable to BFR <200 and 13% to TT <240, compared to only 3% for DFR <500. Lower Kt/V was associated with elevated mortality, more so among women (hazard ratio [HR] = 1.13 per 0.1 lower Kt/V, 95% CI: 1.07–1.20) than among men (HR = 1.06 per 0.1 lower Kt/V, 95% CI: 1.00–1.12). The relatively large proportion of low Kt/V cases in Japanese facilities may potentially be reduced 30% by increasing BFR to 200 mL/min and TT to 4 hours thrice weekly in HD patients. Associations of low Kt/V with elevated mortality suggest that modification of these practices may further improve survival for Japanese HD patients. 相似文献
970.
Masahiro Suzuki Naoki Yokoyama Mutsumi Kimura Kenji Hanabusa Hirofusa Shirai 《Reactive and Functional Polymers》1999,40(3):241-248
The solvent effects on the photosensitized charge separation using partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes (RuQPIm), in which bis(2,2′-bipyridine)ruthenium(II) complexes are coordinated to the imidazolyl residues on the poly(1-vinylimidazole) partially quaternized by 1-bromohexadecane and the degree of quaternization is 19 (RuQPIm-19) and 44 (RuQPIm-44) molar percentage, have been investigated in methanol and methanol–NMF (NMF: N-methylformamide). These systems consist of RuQPIm-19 and RuQPIm-44 as photosensitizers, 1,1′-dimethyl-4,4′-bipyridinium dication (MV2+) and 1,1′-didodecyl-4,4′-bipyridinium dication (C12V2+) as electron acceptors, and triethanolamine (TEOA) as a sacrificial donor. The addition of NMF mainly affect the forward and back reactions in the charge separation reactions. In RuQPIm-19 systems, the reaction proceeds through an interactive process, which is through the viologen having π–π interaction for MV2+ and van der Waals interaction for C12V2+. In contrast, the reaction proceeds through a direct process by MV2+ having no interaction and through an interactive process by C12V2+ undergoing van der Waals interaction with the polymer for RuQPIm-44 systems. For MV2+, the rates of MV·+ formation increased, although the quenching efficiency decreased with increasing NMF content for RuQPIm-19 and RuQPIm-44. These results are attributed to stabilization of MV·+ species by π–π interaction for RuQPIm-19 and steric repulsion between MV·+ species and RuQPIm-44; namely, the restriction of the back reactions by these effects. In contrast, for C12V2+, the rates of C12V·+ formation decreased and the quenching efficiency increased with the addition of NMF. These are attributed to that the addition of NMF increases the van der Waals interaction of the C12V2+ with these polymers and the diffusion of the C12V·+ species into the bulk solution; namely, the back reaction is accelerated. Furthermore, it is suggested that the conformational changes in these polymers contribute to the charge separation reaction. 相似文献