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101.
102.
103.
This study presents a three‐dimensional numerical analysis of the effect of boundary layer thickness on vortex structures and heat transfer behind a hill mounted in a laminar boundary layer. When the thickness of the velocity boundary layer is comparable to the hill height, a hairpin vortex is formed symmetrically to the center of the spanwise direction in the wake. A secondary vortex is formed between the legs, and horn‐shaped secondary vortices appear under the concave parts of the hairpin vortex. When the boundary layer thickness increases, the legs and horn‐shaped secondary vortices move toward the center of the spanwise direction, and thus heat transport and heat transfer increase there. At this time, high‐turbulence areas generated locally move toward the center of the spanwise direction with an increase in the boundary layer thickness. With a further increase in the boundary layer thickness, steady streamwise vortices are formed downstream of the hill, but the heat transfer decreases. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20261 相似文献
104.
Tomio Okawa Taisuke Goto Jun Minamitani Yosuke Yamagoe 《International Journal of Heat and Mass Transfer》2009,52(15-16):3665-3675
A simple theory was developed to elucidate the influence of sinusoidal oscillation of the inlet flow rate on the occurrence of liquid film dryout in an annular two-phase flow regime in a boiling channel. The theory assumes that the critical heat flux (CHF) under an oscillatory condition can be calculated from values in steady states provided that the effect of axial mixing of the liquid film is appropriately considered. The trends of CHFs calculated using a one-dimensional three-fluid model and those experimentally measured under atmospheric pressure were in reasonable agreement with the proposed theory. However, the CHF values measured under oscillatory conditions were usually higher in the experiment than in the numerical simulation, which indicated that axial liquid transport induced by disturbance waves might enhance axial mixing of the liquid film. 相似文献
105.
Plasma enhanced chemical vapor deposition using a non-thermal plasma jet was applied to deposition of ZnO films. Using vaporized bis(octane-2,4-dionato)zinc flow crossed by the plasma jet, the deposition rate was as high as several tens of nm/s. From the results of infrared spectra, the films deposited at the substrate temperature Tsub = 100 °C contained a significant amount of carbon residue, while the films prepared at Tsub = 250 °C showed less carbon fraction. The experimental results confirmed that the plasma jet decomposed bis(octane-2,4-dionato)zinc in the gaseous phase and on the substrate, and that there should be the critical Tsub to form high-quality ZnO films in the range from 100 to 250 °C. 相似文献
106.
Facile purification of tocopherols from soybean oil deodorizer distillate in high yield using lipase 总被引:16,自引:0,他引:16
Yuji Shimada Seiichi Nakai Masaharu Suenaga Akio Sugihara Motohiro Kitano Yoshio Tominaga 《Journal of the American Oil Chemists' Society》2000,77(10):1009-1013
Tocopherols have been purified from deodorizer distillate produced in the final deodorization step of vegetable oil refining
by a process including molecular distillation. Deodorizer distillate contains mainly tocopherols, sterols, and free fatty
acids (FFA); the presence of sterols hinders tocopherol purification in good yield. We found that Candida rugosa lipase recognized sterols as substrates but not tocopherols, and that esterification of sterols with FFA could be effected
with negligible influence of water content. Enzymatic esterification of sterols with FFA was thus used as a step in tocopherol
purification. High boiling point substances including steryl esters were removed from soybean oil deodorizer distillate by
distillation, and the resulting distillate (soybean oil deodorizer distillate tocopherol concentrate; SODDTC) was used as
a starting material for tocopherol purification. Several factors affecting esterification of sterols were investigated, and
the reaction conditions were determined as follows: A mixture of SODDTC and water (4∶1, w/w) was stirred at 35°C for 24 h
with 200 U of Candida lipase per 1 g of the reaction mixture. Under these conditions, approximately 80% of sterols was esterified, but tocopherols
were not esterified. After the reaction, tocopherols and FFA were recovered as a distillate by molecular distillation of the
oil layer. To enhance further removal of the remaining sterols, the lipase-catalyzed reaction was repeated on the distillate
under the same reaction conditions. As a result, more than 95% of the sterols was esterified in total. The resulting reaction
mixture was fractionated to four distillates and one residue. The main distillate fraction contained 65 wt% tocopherols with
low contents of FFA and sterols. In addition, the residue fraction contained high-purity steryl esters. Because the process
presented in this study includes only organic solvent-free enzymatic reaction and molecular distillation, it is feasible as
a new industrial purification method of tocopherols.
This work was presented at the Biocatalysis symposium in April 2000, held at the 91st Annual Meeting and Expo of the American
Oil Chemists Society, San Diego, CA. 相似文献
107.
Two different growth modes of carbon nanotubes (CNTs) are identified in ethylene chemical vapour deposition (CVD) using SiO2 as support. With a series of electron microscopy observations, we have found that small-diameter nanotubes favor a root-growth mechanism on nanoporous SiO2 support, while nanotubes with larger diameters prefer a tip-growth. The dependence of growth mode on tube diameter is explained in terms of the porosity of the support and the size distribution of the catalyst. Our results provide clues to control growth of CNTs and obtain well-organized nanotube structures. 相似文献
108.
Shuich Fujii Yuko Fukawa Hiroaki Takahashi Yosuke Inomata Kenichi Okada Kenji Fukui Katsuhiko Shirasawa 《Solar Energy Materials & Solar Cells》2001,65(1-4)
In 1996 a conversion efficiency of 17.1% had been obtained on 15 cm×15 cm mc-Si solar cell. In this paper, large-scale production technology of the high-efficiency processing will be discussed. Enlarging reactive ion etching (RIE) equipment size, technology of passivation, and fine contact grid with low resistance by screenprinted metallization, which is firing through PECVD SiN, have been investigated. 相似文献
109.
Yosuke Inomata Jae-Won Oh Kohei Taniguchi Nobuhiko Sugito Nao Kawaguchi Fumitoshi Hirokawa Sang-Woong Lee Yukihiro Akao Shinji Takai Kwang-Pyo Kim Kazuhisa Uchiyama 《International journal of molecular sciences》2022,23(9)
Non-alcoholic steatohepatitis (NASH) has pathological characteristics similar to those of alcoholic hepatitis, despite the absence of a drinking history. The greatest threat associated with NASH is its progression to cirrhosis and hepatocellular carcinoma. The pathophysiology of NASH is not fully understood to date. In this study, we investigated the pathophysiology of NASH from the perspective of glycolysis and the Warburg effect, with a particular focus on microRNA regulation in liver-specific macrophages, also known as Kupffer cells. We established NASH rat and mouse models and evaluated various parameters including the liver-to-body weight ratio, blood indexes, and histopathology. A quantitative phosphoproteomic analysis of the NASH rat model livers revealed the activation of glycolysis. Western blotting and immunohistochemistry results indicated that the expression of pyruvate kinase muscle 2 (PKM2), a rate-limiting enzyme of glycolysis, was upregulated in the liver tissues of both NASH models. Moreover, increases in PKM2 and p-PKM2 were observed in the early phase of NASH. These observations were partially induced by the downregulation of microRNA122-5p (miR-122-5p) and occurred particularly in the Kupffer cells. Our results suggest that the activation of glycolysis in Kupffer cells during NASH was partially induced by the upregulation of PKM2 via miR-122-5p suppression. 相似文献
110.
Seiichiro Katagiri SungGi Chi Yosuke Minami Kentaro Fukushima Hirohiko Shibayama Naoko Hosono Takahiro Yamauchi Takanobu Morishita Takeshi Kondo Masamitsu Yanada Kazuhito Yamamoto Junya Kuroda Kensuke Usuki Daigo Akahane Akihiko Gotoh 《International journal of molecular sciences》2022,23(9)
KIT is a type-III receptor tyrosine kinase that contributes to cell signaling in various cells. Since KIT is activated by overexpression or mutation and plays an important role in the development of some cancers, such as gastrointestinal stromal tumors and mast cell disease, molecular therapies targeting KIT mutations are being developed. In acute myeloid leukemia (AML), genome profiling via next-generation sequencing has shown that several genes that are mutated in patients with AML impact patients’ prognosis. Moreover, it was suggested that precision-medicine-based treatment using genomic data will improve treatment outcomes for AML patients. This paper presents (1) previous studies regarding the role of KIT mutations in AML, (2) the data in AML with KIT mutations from the HM-SCREEN-Japan-01 study, a genome profiling study for patients newly diagnosed with AML who are unsuitable for the standard first-line treatment (unfit) or have relapsed/refractory AML, and (3) new therapies targeting KIT mutations, such as tyrosine kinase inhibitors and heat shock protein 90 inhibitors. In this era when genome profiling via next-generation sequencing is becoming more common, KIT mutations are attractive novel molecular targets in AML. 相似文献