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排序方式: 共有436条查询结果,搜索用时 0 毫秒
61.
Mitsuhiro Fukuta Tadashi Yanagisawa Masao Shimasaki Yasuhiro Ogi 《International Journal of Refrigeration》2006,29(7):1058-1065
The mixing of refrigeration oil with refrigerant in a refrigeration cycle has great influence on cycle performance. A sampling method is the most general way to measure the mixing ratio of refrigerant and refrigeration oil. Since the sampling method is time-consuming and reduces the amount of refrigerant and oil in the cycle, a real-time measurement is desirable. In this study, a refractive index measurement was applied to measure the mixing ratio of refrigerant/oil mixture. A laser displacement sensor was used to detect any change in optical path which results from changes of the refractive index of refrigerant/oil mixture. For the practical application of real-time measurement of the oil circulation ratio (OCR) in the refrigeration cycle, a correlation between the refractive index and the mixing ratio was developed. In addition, the changes of the refractive index in a range of a few percentages of the oil concentration and under subcooled conditions were measured. Finally, a transient measurement of the OCR in a practically operating refrigeration cycle was carried out successfully. 相似文献
62.
Andréas LyberisAdam J. Stevenson Akiko SuganumaSandrine Ricaud Frédéric DruonFrédéric Herbst Daniel VivienPatrick Gredin Michel Mortier 《Optical Materials》2012,34(6):965-968
In Yb:CaF2, the coordination of Yb3+ in the CaF2 lattice determines the spectroscopic properties that make Yb:CaF2 a good candidate for high power laser applications. In this work, we measure the optical absorption, emission, and fluorescence lifetime of 0.1, 1, 5, and 10 at% Yb:CaF2 ceramics to determine whether Yb3+ substitutes as hexamer clusters giving rise to the tenability and long fluorescent lifetime observed in Yb:CaF2 single crystals. Absorption and emission spectra show that the concentration of Yb3+ present in hexamer clusters, as opposed to isolated ions, increases with increasing Yb3+ content. Fluorescence lifetime also increases with increasing Yb3+ content. Laser testing on a 1 at% Yb:CaF2 transparent ceramic demonstrates that these materials are viable laser gain media. 相似文献
63.
Kanapathipillai M Mammoto A Mammoto T Kang JH Jiang E Ghosh K Korin N Gibbs A Mannix R Ingber DE 《Nano letters》2012,12(6):3213-3217
A cancer nanotherapeutic has been developed that targets the extracellular matrix (ECM)-modifying enzyme lysyl oxidase (LOX) and alters the ECM structure. Poly(d,l-lactide-co-glycolide) nanoparticles (~220 nm) coated with a LOX inhibitory antibody bind to ECM and suppress mammary cancer cell growth and invasion in vitro as well as tumor expansion in vivo, with greater efficiency than soluble anti-LOX antibody. This nanomaterials approach opens a new path for treating cancer with higher efficacy and decreased side effects. 相似文献
64.
Shahira Liza Junko Hieda Hiroki Akasaka Naoto Ohtake Yusuke Tsutsumi Akiko Nagai 《Science and Technology of Advanced Materials》2013,14(1):76-87
AbstractDiamond-like carbon (DLC) material is used in blood contacting devices as the surface coating material because of the antithrombogenicity behavior which helps to inhibit platelet adhesion and activation. In this study, DLC films were doped with boron during pulsed plasma chemical vapor deposition (CVD) to improve the blood compatibility. The ratio of boron to carbon (B/C) was varied from 0 to 0.4 in the film by adjusting the flow rate of trimethylboron and acetylene. Tribological tests indicated that boron doping with a low B/C ratio of 0.03 is beneficial for reducing friction (μ = 0.1), lowering hardness and slightly increasing wear rate compared to undoped DLC films. The B/C ratio in the film of 0.03 and 0.4 exhibited highly hydrophilic surface owing to their high wettability and high surface energy. An in vitro platelet adhesion experiment was conducted to compare the blood compatibility of TiNb substrates before and after coating with undoped and boron doped DLC. Films with highly hydrophilic surface enhanced the blood compatibility of TiNb, and the best results were obtained for DLC with the B/C ratio of 0.03. Boron doped DLC films are promising surface coatings for blood contacting devices. 相似文献
65.
In our previous study, sorption process of water into a biocompatible polymer film, poly(2-methoxyethyl acrylate) (PMEA) was monitored by time-resolved in situ attenuated total reflection infrared (ATR-IR) spectroscopy [S. Morita, et al., Langmuir 23, 3750 (2007)]. In the present study, noisy and heavily overlapped O-H stretching vibrational bands of diffusing water have been analyzed from the series spectra where the spectral shapes change irregularly with time. In spite of these complications, a powerful spectral analysis technique, multivariate curve resolution (MCR) by means of alternating least squares (ALS), yielded smooth and meaningful pure component spectra and detailed kinetic sorption profiles of each component, excluding noise. Ordinary smoothing techniques and Gaussian curve fitting would not achieve these significant results. The quantification of the kinetic parameters such as amplitudes (a) and relaxation time constants (tau) is significant for the systematic development of biocompatible materials and also for revealing the mechanisms of biocompatibility of a material. Moreover, the ratios of coefficients of each component at saturation corresponded well to the values obtained by Tanaka et al. measured by gravimetric analysis. This study is the first to report the detailed concentration profile of each water component whose sorption kinetics is discussed comprehensively. 相似文献
66.
Satoshi Yoshida Yoshinari Nishikubo Akiko Konno Toru Sugawara Yoshinari Miura Jun Matsuoka 《International Journal of Applied Glass Science》2012,3(1):3-13
It is known that indentation using a diamond indenter induces permanent densification to result in plastic or inelastic deformation of glass. However, it is still unclear whether a high tensile stress causes such a structural change or not. In this study, fracture- and indentation-induced structural changes of glasses with the compositions of 20 Na2O − 40x B2O3 – (80−40x) SiO2 (in mol%, x = 0, 0.5, 1, 1.5) are investigated. Two-point bending tests of the glass fibers are performed to apply a high tensile stress to the glasses, and Vickers indentation tests of the glasses are also carried out for comparison. The structural change of the glass is evaluated by using Raman spectroscopy. It is elucidated that a tensile side of the fractured fiber for every composition shows a permanent structural change, which is characterized by a lower wave number shift of Raman peak assigned to the Si-O-Si bending vibration mode. It is also found that the behaviors of Raman peaks of the fractured fiber are opposite to those of the indented glass under a high compressive stress. 相似文献
67.
Masanori Kawakami Yutaka Abe Akiko Kaneko Yuji Yamamoto Koji Hasegawa 《Microgravity science and technology》2010,22(2):145-150
Under the microgravity environment, new and high quality materials with a homogeneous crystal structure are expected to be
manufactured by undercooling solidification, since the material manufacturing under the microgravity environment is more static
than that under the normal gravity. However, the temperature change on the interface of the material in space can affect on
the material processing. The purpose of the present study is to investigate effect of the temperature change of interface
on the large levitated droplet interface. A water droplet levitated by the acoustic standing wave is heated by YAG laser.
In order to heat the water droplet by the laser heating, rhodamine 6G is solved in it to achieve high absorbance of the laser.
The droplet diameter is from 4 to 5.5 mm. The deformation of the droplet interface is observed by high speed video camera.
The temperature of droplet is measured by the radiation thermometer. It is noticed that the larger droplet under the higher
sound pressure tends to oscillate remarkably by the laser heating. 相似文献
68.
Masaki T Ishikawa T Paradis PF Yoda S Okada JT Watanabe Y Nanao S Ishikura A Higuchi K Mizuno A Watanabe M Kohara S 《The Review of scientific instruments》2007,78(2):026102
A compact electrostatic levitator was developed for the structural analysis of high-temperature liquids by x-ray diffraction methods. The size of the levitator was 200 mm in diameter and 200 mm in height and can be set up on a two axis diffractometer with a laboratory x-ray source, which is very convenient in performing structural measurements of high-temperature liquids. In particular, since the laboratory x-ray source allows a great amount of user time, preliminary or challenging experiments can be performed with trial and error, which prepares and complements synchrotron x-ray experiments. The present small apparatus also provides the advantage of portability and facility of setting. To demonstrate the capability of this electrostatic levitator, the static structure factors of alumina and silicon samples in their liquid phases were successfully measured. 相似文献
69.
In order to develop a short-term algal toxicity test, the growth of and the phosphate uptake by the green alga Selenastrum capricornutum during batch culture were observed. In the control medium, S. capricornutum took up phosphate earlier than it grew. It was also observed that the phosphate uptake was inhibited by the presence of a toxicant. From these results, phosphate uptake was considered as one of the useful effect parameters for a short-term algal toxicity test. As the removal rate of phosphate from the medium is a function of the amount of algal cell initially inoculated, the test period is variable. The relationship between the amount of inoculation and phosphate uptake was examined and the test conditions suitable for a 3-h toxicity test were established as one example. According to this test procedure, the inhibitory effect of some toxicants on the phosphate uptake was determined. For comparison, a conventional algal assay based on algal growth was also performed. The EC50s for both tests were close. This indicated that the algal toxicity test method proposed in this paper would be useful for the uses where rapidity is required. 相似文献
70.
In recent years, it is remarkable that various robots are being developed, and the development of robot technology is beginning to be taken into an actual living space. There are still many questions that we will have to answer for the harmonization of living together with a robot. This study is focused on "the study of how to plan and design a living space in harmonizing with robots", and focused on the effects of infants (subjects) along with the distance between robots and themselves. The study is to seek for the minimum distance for the subjects who felt that "I do not want a robot to be any closer being approached to me". This experiment was conducted among 30 infants at the kindergarten, utilizing a small experimental robot. A small robot whose dimension is 120 mm (W) ×130 mm (D) × 70 mm (H), approaching infants as is to see if it would make any differences to the infant's reactions. 相似文献