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排序方式: 共有6720条查询结果,搜索用时 15 毫秒
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Daejun Chang Taejin Rhee Kiil Nam Kwangpil Chang Donghun Lee Samheon Jeong 《Reliability Engineering & System Safety》2008,93(12):1877-1885
This study investigated the availability and safety concerns of the conventional and prospective propulsion systems for LNG carriers:
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- dual-fuel steam turbine mechanical (DFSM) propulsion,
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- dual-fuel diesel electric (DFDE) propulsion,
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- dual-fuel gas turbine electric (DFGE) propulsion,
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- dual-fuel diesel mechanical (DFDM) propulsion, and
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- diesel mechanical propulsion with reliquefaction (SFDM+R).
994.
Kim SJ Lee JK Kim JW Jung JW Seo K Park SB Roh KH Lee SR Hong YH Kim SJ Lee YS Kim SJ Kang KS 《Journal of materials science. Materials in medicine》2008,19(8):2953-2962
Stem cell-based therapy has recently emerged for use in novel therapeutics for incurable diseases. For successful recovery from neurologic diseases, the most pivotal factor is differentiation and directed neuronal cell growth. In this study, we fabricated three different widths of a micro-pattern on polydimethylsiloxane (PDMS; 1, 2, and 4 microm). Surface modification of the PDMS was investigated for its capacity to manage proliferation and differentiation of neural-like cells from umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs). Among the micro-patterned PDMS fabrications, the 1 microm-patterned PDMS significantly increased cell proliferation and most of the cells differentiated into neuronal cells. In addition, the 1 microm-patterned PDMS induced an increase in cytosolic calcium, while the differentiated cells on the flat and 4 microm-patterned PDMS had no response. PDMS with a 1 microm pattern was also aligned to direct orientation within 10 degrees angles. Taken together, micro-patterned PDMS supported UCB-MSC proliferation and induced neural like-cell differentiation. Our data suggest that micro-patterned PDMS might be a guiding method for stem cell therapy that would improve its therapeutic action in neurological diseases. 相似文献
995.
The memory characteristics of ZnO nanowire-based nano-floating gate memory (NFGM) with Pt nanocrystals acting as the floating gate nodes were investigated in this work. Pt nanocrystals were embedded between Al(2)O(3) tunneling and control oxide layers deposited on ZnO nanowire channels. For a representative ZnO nanowire-based NFGM with embedded Pt nanocrystals, a threshold voltage shift of 3.8?V was observed in its drain current versus gate voltage (I(DS)-V(GS)) measurements for a double sweep of the gate voltage, revealing that the deep effective potential wells built into the nanocrystals provide our NFGM with a large charge storage capacity. Details of the charge storage effect observed in this memory device are discussed in this paper. 相似文献
996.
Silicon-based aluminum casting alloys are known to be one of the most widely used alloy systems mainly due to their superior casting characteristics and unique combination of mechanical and physical properties. However,manufacturing of thin-walled aluminum die-casting components,less than 1.0 mm in thickness,is generally known to be very difficult task to achieve aluminum casting alloys with high fluidity.Therefore,in this study,the optimal die-casting conditions for producing 297 mm×210 mm×0.7 mm thin-walled aluminum component was examined experimentally by using 2 different gating systems,tangential and split type,and vent design.Furthermore,computational solidification simulation was also conducted.The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after solidification.It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion. 相似文献
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Jeong Su Kim NoGill Park HyoungWoo Lee 《Journal of Mechanical Science and Technology》2016,30(2):611-621
This study models a 3-dimensional planetary gear system using the transfer matrix method. The local transfer matrices between each component of the planetary gear set were derived with consideration of the tooth width, and the transfer matrix of a planetary gear system corresponding to the inertial transfer matrix was determined. The eigenvalue analysis of the transfer matrix suggested an analysis method in the form of a lambda matrix, instead of the direct search method through a characteristic polynomial. The boundary conditions at the first and the last stations of the entire transfer matrix were partitioned into known and unknown values to generate a concentrated transfer matrix and a latent equation, and the eigenvalue problem in the lambda matrix was solved. The characteristics of the responses according to the phase state of the harmonic component of the transmission error were reviewed through the steady-state response and mode shape type. 相似文献
1000.
The optimum levels of transglutaminase (TGase), l-ascorbic acid (l-AA), and xylanase (Xyl) were determined using response surface methodology to improve quality and consumer acceptability of bread made with wheat flour. A Box-Behnken design with three independent variables (TGase, l-AA, and Xyl) and three levels was used to develop models for the different responses (peak time, mixing tolerance, extensibility, resistance, specific volume, hardness, and consumer acceptability). Overall, l-AA and Xyl improved dough and bread properties, whereas the addition of TGase positively affected to texture and overall acceptability by consumer test. The optimal formulation for dough and bread properties and consumer acceptability were identified and the optimal value was 0.36 g/100 g TGase, 0.026 g/100 g Xyl, and 0.005 g/100 g l-AA. The results demonstrate that the addition of optimum amounts of TGase, Xyl, and l-AA improves the baking quality of the flour by enhancing dough properties and increase the consumer acceptability of the bread. 相似文献