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Kiho Bae Kyung Sik Son Jun Woo Kim Suk Won Park Jihwan An Fritz B. Prinz Joon Hyung Shim 《International Journal of Hydrogen Energy》2014
This work elucidated the proton-incorporation mechanism in ALD YSZ1. Isotope 2H2O was used as an oxidant to trace proton incorporation. The ratio of ZrO2 to Y2O3 ALD cycles was varied from 1:1 to 5:1. TEM confirmed that the ALD YSZ films grew as fully crystallized columnar grains in the cubic ZrO2 phase. SIMS indicated that the Y3+ and 2H+ concentrations were linearly correlated, indicating yttria-deposition-induced proton incorporation. XPS confirmed an appreciable amount of Y(OH)3 proportional to the 2H+ content in the ALD YSZ, as was also detected by SIMS. Oxide ion vacancies created by the replacement of ZrO2 with relatively small amounts of Y2O3 provided additional vacancies for proton incorporation, resulting in steeper [2H+]/[Y3+] slopes. 相似文献
123.
A host material with high triplet energy based on dibenzofuran and triphenylamine interconnected through diphenylmethylene linkage was synthesized and photophysical properties of the host material were investigated. A high triplet energy of 2.90 eV was obtained due to complete separation of an electron donating triphenylamine and accepting dibenzofuran by diphenylmethylene linkage. It was found out that intermolecular charge transfer dominated the light emission of the host material. 相似文献
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Kyung Yoen Won Young Soo Kim Kyeong Keun Oh 《Korean Journal of Chemical Engineering》2012,29(10):1341-1346
Cellulose rich barley straw, which has a glucan content of 62.5%, followed by dilute acid pretreatment, was converted to bioethanol by simultaneous saccharification and fermentation (SSF). The optimum fractionation conditions for barley straw were an acid concentration of 1% (w/v), a reaction temperature of 158 °C and a reaction time of 15 min. The maximum saccharification of glucan in the fractionated barley straw was 70.8% in 72 h at 60 FPU/gglucan, while the maximum digestibility of the untreated straw was only 18.9%. With 6% content WIS (water insoluble solid) for the fractionated barley straw, 70.5 and 83.2% of the saccharification yield were in SHF and SSF (representing with glucose equivalent), respectively, and a final ethanol concentration of 18.46 g/L was obtained under the optimized SSF conditions: 34 °C with 15 FPU/g-glucan enzyme loading and 1 g dry yeast cells/L. The results demonstrate that the SSF process is more effective than SHF for bioethanol production by around 18%. 相似文献
126.
Tae-Kyun Oh Sung Oh Seongdae Kim Jae Sung Park Nagarajan Vinod Kyung Min Jang Sei Chang Kim Chang Won Choi Suk-Min Ko Dong Kee Jeong Rajangam Udayakumar 《International journal of molecular sciences》2014,15(9):15571-15591
A full-length phytase gene (phy) of Aspergillus nidulans was amplified from the cDNA library by polymerase chain reaction (PCR), and it was introduced into a bacterial expression vector, pET-28a. The recombinant protein (rPhy-E, 56 kDa) was overexpressed in the insoluble fraction of Escherichia coli culture, purified by Ni-NTA resin under denaturing conditions and injected into rats as an immunogen. To express A. nidulans phytase in a plant, the full-length of phy was cloned into a plant expression binary vector, pPZP212. The resultant construct was tested for its transient expression by Agrobacterium-infiltration into Nicotiana benthamiana leaves. Compared with a control, the agro-infiltrated leaf tissues showed the presence of phy mRNA and its high expression level in N.
benthamiana. The recombinant phytase (rPhy-P, 62 kDa) was strongly reacted with the polyclonal antibody against the nonglycosylated rPhy-E. The rPhy-P showed glycosylation, two pH optima (pH 4.5 and pH 5.5), an optimum temperature at 45~55 °C, thermostability and broad substrate specificities. After deglycosylation by peptide-N-glycosidase F (PNGase-F), the rPhy-P significantly lost the phytase activity and retained 1/9 of the original activity after 10 min of incubation at 45 °C. Therefore, the deglycosylation caused a significant reduction in enzyme thermostability. In animal experiments, oral administration of the rPhy-P at 1500 U/kg body weight/day for seven days caused a significant reduction of phosphorus excretion by 16% in rat feces. Besides, the rPhy-P did not result in any toxicological changes and clinical signs. 相似文献
127.
Dae Chul Ha Ha Young Lee Yeo Won Son Soon Hong Yuk Youn Woong Choi Byung Kook Kwak Byung Cheol Shin Cheong-Weon Cho Sun Hang Cho 《Nanoscale research letters》2014,9(1):38
The purpose of this study was to synthesize biocompatible poly(2-hydroxyethyl aspartamide)–C16-iron oxide (PHEA-C16-iron oxide) nanoparticles and to evaluate their efficacy as a contrast agent for magnetic resonance imaging of lymph nodes. The PHEA-C16-iron oxide nanoparticles were synthesized by coprecipitation method. The core size of the PHEA-C16-iron oxide nanoparticles was about 5 to 7 nm, and the overall size of the nanoparticles was around 20, 60, and 150 nm in aqueous solution. The size of the nanoparticles was controlled by the amount of C16. The 3.0-T MRI signal intensity of a rabbit lymph node was effectively reduced after intravenous administration of PHEA-C16-iron oxide with the size of 20 nm. The in vitro and in vivo toxicity tests revealed the high biocompatibility of PHEA-C16-iron oxide nanoparticles. Therefore, PHEA-C16-iron oxide nanoparticles with 20-nm size can be potentially useful as T2-weighted MR imaging contrast agents for the detection of lymph nodes. 相似文献
128.
Eun-Sil Kang Da Won Chae Baekjin Kim Young Gyu Kim 《Journal of Industrial and Engineering Chemistry》2012,18(1):174-177
2,5-Dihydroxymethylfuran (DHMF) and 5-hydroxymethylfuranoic acid (HMFA) are the versatile intermediate chemicals of high industrial potential. An efficient preparation of both DHMF and HMFA is reported from biomass-derived HMF via a Cannizzaro reaction using ionic liquids as a reusable reaction solvent under the water-free conditions. The operationally simple and environment-friendly process produces both DHMF and HMFA from HMF consistently in good to high yields up to five runs with the recycled ionic liquid. 相似文献
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