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181.
Woo‐Il Baek Hem Raj Pant R. Nirmala Ki‐Taek Nam Hyun‐Ju Oh Hak‐Yong Kim 《Polymer International》2012,61(5):844-849
In the present study, the effect of adhesive on the morphology of different electrospun polymeric mats was investigated. The modification of two polymers, poly(methyl methacrylate) and poly(vinyl chloride), was carried out by blending the polymers with different amounts of poly(butyl acrylate) (PBA) adhesive to investigate the effect of different amounts of adhesive with heat hardener in hybrid mats. The introduction of various concentrations of PBA into different polymer solutions led to the formation of point‐bonded electrospun fibrous mats. Scanning electron microscopy images indicated that point‐bonded polymer/adhesive fibers were uniformly distributed throughout the mats. Fourier transform infrared spectrometry, contact angle measurements and thermogravimetric analysis were used to study the different properties of the hybrid mats. The tensile strength of the blended fibrous electrospun mats was increased effectively. This enhancement of the mechanical properties of the mats due to the presence of adhesive increases the number of potential applications of the electrospun mats, especially for mechanically weak polymers. Copyright © 2012 Society of Chemical Industry 相似文献
182.
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
183.
184.
Hyun-Wung Kwon Suk-Yoon Hong Dae-Kyun Oh Jihoon Lee Doo-Jin Hwang Ok-Sam Kim Jee-Hun Song 《Journal of Mechanical Science and Technology》2014,28(9):3405-3410
Energy flow analysis (EFA) can be used effectively to predict structural vibration in the medium-to-high frequency ranges. In this study, the energy flow finite element method (EFFEM), based on EFA, was used to predict the vibrations of a reinforced cylindrical structure in water. The predicted results of the vibrational energy density for the structure were compared with corresponding experimental results. The structure was divided into several subsystems in the experiment, with several accelerometers attached to each subsystem. The input power excited into the experimental structure was measured using an impedance-head adhered to an exciter. Measured input power was used to predict vibration of the reinforced cylindrical structure by EFFEM in water for comparing experimental and numerical results. A comparison between the experimental and predicted results for the vibrational energy density showed that EFFEM was an effective tool for predicting structural vibration. 相似文献
185.
Xin Jin Chang‐Sei Kim Guy A. Dumont J. Mark Ansermino Jin‐Oh Hahn 《International Journal of Adaptive Control and Signal Processing》2017,31(2):240-254
This paper presents a semi‐adaptive control approach to closed‐loop medication infusion problems. The rationale underlying this approach is to design a controller that can adapt model parameters with a large impact on the model's fidelity while fixing the remaining parameters at nominal values. In this paper, a control‐oriented model for this purpose is derived via system identification and sensitivity analysis of a low‐order model capturing the direct dose‐response relationship Using the model thus derived, a model‐reference adaptive controller and a composite adaptive controller are designed and compared with each other. In‐silico simulation results using remifentanil's effect on respiratory rate as an example indicate that both controllers can regulate the output at commanded set points. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
186.
Jeongseok Oh Seokswoo Cho Bumsik Ham 《Journal of Mechanical Science and Technology》2017,31(12):5761-5767
In a polyethylene boat, a transom pod is subjected to repeated thrust forces generated by an outboard motor. The structural design of the transom pod for the outboard motor must be considered because it is subjected to cyclic bending moments causing thrust forces of the outboard motor. We designed a transom pod reinforced with aluminum alloy plate inside the transom pod in a polyethylene boat and obtained an optimal thickness of the Al alloy plate to ensure the transom pod durability. We then performed a structural analysis for the transom pod reinforced with Al alloy plate and estimated the fatigue life using modified Goodman diagram. The optimal thickness of Al alloy plate was 7 mm. 相似文献
187.
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
188.
Jin Kyung Song Duwoon Kim Jong-Bang Eun Byeong-Dae Choi Myung Joo Oh Sung Ju Jung 《Food science and biotechnology》2012,21(5):1405-1411
The edible ascidian, sea squirt Halocynthia roretzi (Drasche) is marine invertebrate that is a valuable source of foods and bioactive compounds. A severe disease of the sea squirt characterized by degeneration of tunic fibers formed of bundled cellulose microfibrils has occurred. We hypothesized that bacteria lyse the cellulose fibril structure, cellulase activity may be a causative agent of the disease. Among the bacteria isolated from diseased sea squirt, Pseudoalteromonas sp. NO3 had cellulase activity based on a Congo red overlay assay and starch-reducing activity. Sea squirts exhibited 40–100% cumulative mortality after injection with Pseudoalteromonas sp. NO3 using doses of 2×106?2×108 colony forming unit (CFU)/individual. Dead sea squirts possess thinner and ruptured tunics, which were similar to natural outbreaks. These results suggest that Pseudoalteromonas sp. NO3 possessing cellulase activity is one of the causes of tunic softness syndrome in sea squirt. 相似文献
189.
Sang Hyun AhnInsoo Choi Oh Joong KwonTaeho Lim Jae Jeong Kim 《International Journal of Hydrogen Energy》2012,37(1):41-50
CoRuPt and CoPtRu catalysts were prepared on carbon paper (CP) using various electrochemical processes including Sn sensitization, Pd activation, Co electrodeposition and galvanic displacement. The Sn-Pd process is a surface treatment that guarantees a larger number of nucleation sites on CP for subsequent Co electrodeposition by modifying the surface to be more hydrophilic. Co particles were deposited on Sn-Pd-treated CP (SCP) by controlling deposition potential and time. Then, Pt and Ru galvanic displacements were performed on the Co particles to form CoRuPt/SCP and CoPtRu/SCP catalysts. Electrochemical measurements confirmed that the CoRuPt/SCP - 1 catalyst with a 1.02 Pt/Ru surface molar ratio showed a peak potential of 741 mV (vs. NHE) for methanol oxidation and 637 mV for carbon monoxide stripping. These values were 80 and 8 mV lower, respectively, than those of a PtRu/C commercial catalyst. 相似文献
190.
ChangHwan Shin Tae-Hyun Chun Dong-Seok Oh Wang-Kee In 《Journal of Mechanical Science and Technology》2012,26(10):3119-3124
The Korea Atomic Energy Research Institute (KAERI) has been developing a dual-cooled annular fuel for a power uprate of 20% in an optimized pressurized water reactor (PWR) in Korea, OPR1000. The dual-cooled annular fuel is configured to allow coolant flow through the inner channel as well as the outer channel. Several thermal-hydraulic issues exist for the application of dual-cooled annular fuel to OPR1000. One is the hypothetical event of inner channel blockage because the inner channel is an isolated flow channel without the coolant mixing between the neighboring flow channels. The inner channel blockage could cause a departure from nucleate boiling (DNB) in the inner channel that eventually results in fuel failure. A long lower end plug for the annular fuel was invented to provide flow holes by perforating the side surface of the end plug body. The side holes in the lower end plug are expected to supply a minimum coolant in the inner channel to prevent the DNB occurrence in the event of partial or even complete blockage of the inner channel entrance. But due to the very unusual shape of the lower end plug, it is difficult to estimate the flow resistance of the side flow holes using empirical equations available in the open literature. An experiment and computational fluid dynamics (CFD) analysis were performed to investigate the bypass flow through the side holes of the end plug in the case of complete entrance blockage of the inner channel. The form loss coefficient in the side holes was also estimated using the pressure drop along the bypass flow path. 相似文献