• Fashion & Textile Research Journal
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• v.5 no.1
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• pp.64-70
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• 2003

Water-insoluble chitosan with molecular weight of 2,000,000, 580,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were prepared to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus (MRSA). As experimental method, the Shake Flask Method (SFM) and Modified Shake Flask Method (MSFM) were applicated. The anti-microbial activity of chitosan/acetic acid aqueous solution is consistent irrespective of Mw of chitosan. MIC value of SFM measurement was 0.2 ppm, and MIC value of modified SFM measurement was 25 ppm. But MIC value of chitosan/acetic add solution and chitosan treated cotton filter paper was equally 5 ppm. The antibacterial activities of chitosan were different in different test measurements employed. The antibacterial activities of chitosan/acetic acid solution and chitosan treated cotton filter paper were also different. Therefore, it needs to be pointed out that the test measurements of anti-microbial activity have some problems.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.267-267
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• 2006

Human umbilical cord blood was stored at $4^{\circ}C$ in the Pluronic-immobilized flask as well as commercially available bio-inert flasks, and flow cytometric analysis of surface markers was performed on hematopoietic stem cells after cultivation. The number of cells expressing $CD34^{+}$ in umbilical cord blood on the Pluronic-immobilized flask was extremely higher than those obtained using other flasks. It is concluded that the flexible and hydrophilic segments of Pluronic conjugated on the flask surface are the reason for the effective preservation of hematopoietic stem cells in the Pluronic-immobilized flask.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.341-345
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• 2003

Effect of immobilization on the production of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) by Nicotiana tabacum cells was investigated using polyurethane foam as immobilization matrices. The cell activity and the hGM-CSF production were maintained for 16 days in spite of 3 times of media exchange. Under the same conditions of temperature and agitation rate, maximum concentrations of hGM-CSF in a 500-mL spinner flask and 100-mL Erleuneyer flasks were 17.3 ${\mu}g/L$ and 9.8 ${\mu}g/L$, respectively. Consequently high hGM-CSF production could be possible in spinner flask when the rate and amount of media exchange were optimized.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.114-122
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• 2010

Hydroxy fatty acids have gained important attentions because of their special properties such as higher viscosity and reactivity compared to non-hydroxy fatty acids. The new bacterial isolate Pseudomonas aeruginosa (PR3) had been well studied to produce mono-, di-, and tri-hydroxy fatty acids from different unsaturated fatty acids. Of those hydroxy fatty acids, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced with high yield from oleic acid by P. aeruginosa PR3. Mostly, the substrates used for the production of hydroxy fatty acid by microorganisms were free fatty acids or synthetic lipids. However, it is highly plausible to use vegetable oils containing oleic acid such as olive oil for DOD production by P. aeruginosa PR3. As a first step to address the utilization of olive oil as a substrate for DOD production, we tried to determine the effect of vessel type on DOD production from olive oil by P. aeruginosa PR3. Of two different flask types of normal flask and baffled-flask, baffled-flask was highly effective for DOD production with all the media tested. Maximum increase of productivity by baffled-flask represented 221% with the medium supplemented with whey powder instead of lactose. Results from this study demonstrated that vessel type and medium composition could be both significant factors for DOD production from olive oil by P. aeruginosa PR3.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.189-196
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• 2001

Octanol/water partition coefficients of 52 chemicals were calculated using RP-HPLC estimation method and predicted by computer program, PCHEM. The result showed relationship between literature values and RP-HPLC observed values (relative coefficient r$^2$＝0.916), but the relationship of PCHEM values with literature values was lower than RP-HPLC value (relative coefficient r$^2$＝0.795). The average difference in partition coefficient between the RP-HPLC method and flask-shaking method was log Kow＝0.54, while the average difference between the values predicted form the computer program and flask- shaking method was log Kow = 0.36 Compared to octanol/water partition coefficients by 3 methods (Flask-shaking, RP-HPLC, computer prediction), the octanol/water partition coefficient values based on the flask-shaking method were very similar to the literature values, while the octanol/water partition coefficient values by RP-HPLC method without to consider the dead time, and computer prediction values did not significantly differ with the literature values.

• KSBB Journal
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• v.13 no.1
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• pp.108-113
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• 1998

The cell growth and amino acid metabolism of a hybridoma cell line in T-flasks, spinner flasks, and a 2L bioreactor were compared. Similar growth and metabolic behaviour were observed for spinner flask and bioreactor cultivations, while those in T-flasks differed significantly. Through a detailed analysis of nutrients and wastes, 7 amino acids were found to be consumed to a much higher extent than the rest of the amino acids. Supplementing the based medium with selected amino acids, glucose, and vitamines increased the cell density by 70%. The addition of vitamines was found to increase the metabolic rates of glucose and lactate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3334-3338
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• 2012

This work has been performed to evaluate the strength of fixtures, which were attached to outer surface of propeller flask to prevent transient movement during filling and cooling stages at Ni-Al-Bronze casting of large marine propellers. Experimental work was carried out to evaluate forces exerted on flask fixtures by measuring strain changes of fixtures due to thermal expansion and contraction during casting processes. Numerical analyses were also made to verify the experimental results and finally to evaluate the validity of arrangement of flask fixtures for casting of marine propellers.

• YAKHAK HOEJI
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• v.13 no.2_3
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• pp.57-61
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• 1969

From the principle of CHN-Corder analysis, it is obvious that seperation of chlorine and bromine in a sample is nearly impossible. In order to analyze, chlorine, bromine, and sulfur seperately in a sample which is a single organic compound or a mixture of organic drugs, combination of flask combustion method and CHN-Corder was successfully attempted.

• KSBB Journal
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• v.5 no.3
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• pp.207-214
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• 1990

Growth properties of carrot hairy roots transformed by Agrobacterium rhizogenes were compared in flask and bioreactor. Oxygen transfer coefficient KLa was measured during the cultivation in bioreactor. In flask cultures, initially sucrose 30g/l was nearly exhausted after 20days. pH was dropped from initially 5.8 to 4.79 after 4 days, but it is stable after that time. Finally, after 28 days, hairy roots were grown about twelve times. In view of the results studied optimum conditions, hairy roots were maintained high growth rates in sucrose 50g/l, pH 5.8, total nitrogen 60mM. Also in bioreactor cultures, fixed stainless sieve in bottom and aerated 0.31 vvm, the results of cultivation by the use of sucrose 50g/l had grown about twenty-eight times and pH variations were liked in flask. As a results, growth rate of 1.756g fresh weight/day/g inoculum in bioreactor were higher about three times than 0.57g fresh weight/day/g inoculum in flask culture. KLa values were showed a tendency to decrease from 0.209 min-1 to 0.068 min-1.