• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.260-267
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• 2020

In this study, supercapacitor based on the all solid state electrolyte with PVA(polyvinyl alcohol), ionic liquid as a BMIMBF4(1-buthyl-3-methylimidazolium tetrafluoroborate) and activated carbon/Ni-MOF composite was fabricated and characterized its electrochemical properties with function of MOF. In order to analysis and comparison that electrochemical performances [including cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge test] of prepared supercapacitor based on activated carbon/Ni-MOF composite and all solid state electrolyte. As a result, specific capacitance of the supercapacitor without Ni-MOF was 380 F/g which value decreased to 340 F/g after adding Ni-MOF to activated carbon as a electrode material. This result exhibited that decreased electrochemical property of the supercapacitor effected on physical hinderance in the electrode. In further, it needs to optimization of the Ni-MOF amount (wt%) in the electrode composite to maximize its electrochemical performances.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.659-666
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• 1995

Fucoidans were isolated from Hizikia fusiformis and Sargassum fulvellum and characterized on their chemical properties. Crude fucoidans were extracted at $65^{\circ}C$ for 1hr with acid solution of pH 2.0, and cetylpyridinum chloride was used for partial purification. The yields of partially purified fucoidans were $2.51\%$ for H. fusiformis, and $65\%$ for S. fulvellum, respectively. The partially purified fucoidans were separated into 3 fractions by DEAE-Sephadex A-25 ion exchange column chromatography and the major fractions were refractionated with fractional preripitation with ethanol. $60-70\%$ ethanol precipitated fraction(P-70) of H. fusiformis and $60-65\%$ ethanol precipitated fraction(P-65) of S. fulvellum turned out to be homogeneous by cellulose acetate electrophoresis and gel filtration chromatography. The molar ratios of fucose, galactose, and sulfate In the purified fucoidans were 1 : 0.66 2.74 for H. fusiformis and 1 : 0.24. 1.46 for 5. fulvellum. The averaged molecular weights of the purified fucoidans from H. fusiformis and S. fulvellum were 26,000 and 105,000, respectively.

• Journal of the Korean Electrochemical Society
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• v.9 no.1
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• pp.1-5
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• 2006

Lithium titanium oxide $(Li_4Ti_5O_{12})$ with spinel-framework structures as anode material for lithium-ion battery was prepared by sol-gel and high energy ball milling (HEBH) method. According to the X-ray diffraction (XRD), Particle Size Analyses(PSA) and scanning electron microscopy (SEM) analysis, uniformly distributed $Li_4Ti_5O_{12}$ particles with grain sizes of 100 nm were observed. Half cells, consisting of $Li_4Ti_5O_{12}$ as working electrode and lithium foil as both counter and reference electrodes showed the high performance of high rate discharge capacity and 173 mAh/g at 0.2C in the range of $1.0\sim2.5 V$. Furthermore, the crystalline structure of $Li_4Ti_5O_{12}$ didn't transform during the lithium intercalation and deintercalation process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.4
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• pp.32-39
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• 1986

A strain of Aspergillus niger CAD 1 which produces considerable amount of beta-galactosidase was selected from extracellular beta-galctaosidase producing fungi isolated from soil. Optimal conditions for the enzyme from Aspergillus niger CAD 1 were the growth in wheat bran supplemented with 0.5% skim milk powder at $30^{\circ}C$ for 72 hrs. The crude enzyme was purified 1,387 fold through DEAE-cellulosc and Sephadex G-100 chromatographr and its recovery was 6.2%, The optimal pH and temperature for the purified enzyme were pH 4.5 ana $45^{\circ}C$, respectively. The Km and Vmax on ONPG were $3.57{\times}10^3M$ and 33.0 unit/mg protein, whereas those on lacose were $83.3{\times}10^3M$and 15.33 unit/mg protein, respectively, The activation energy for the enzyme was 9,900 cal/mol and the enzyme had no metal ion requirement for its activity and stability. The hydrolysis of lactose in skim milk, 4.8% lactose solution and acidic whey were 65%, 70% and 78% after 10 hrs incubation at $45^{\circ}C$, when 182 units of the enzyme were used 50ml of the substrate solutions.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.244-250
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• 1990

A bacterium capable of hydrotyzing raw starch was isolated from soil, which was identified as a strain of Bacillue. The effects of culture conditions and medium compositions on the enzyme production were investigated. Among tested carbon sources, soluble starch and wheat starch were most effective for the production of the enzyme, and the level of concentration for the optimal enzyme production was 0.5%. For nitrogen sources, polypeptone was best for the enzyme production, with the level of 0.5%. The enzyme was maximally produced by cultivating the organism at medium of initial pH 6.5, and temperature of $35^{\circ}C$. The enzyme was partially purified by Sepharose CL-6B gel filtration and DEAESephacel ion-exchange chromatography. The optimal pH and temperature for the enzyme reaction were 6.5 and $70^{\circ}C$, respectively. The enzyme most stable at pH 8.0, and temperature up to $60^{\circ}C$. In kinetic studies, the k, values for corn, wheat, rice and potato starch were 1.7, 1.4,2.5 and 1.090, respectively.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.204-210
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• 1997

Zeolite 4A-impregnated complex molecular sieve was prepared by hydrothermal reaction after aluminosilicate gel was penetrated into the pore of activated carbon granule. The crystals of zeolite 4A mainly were formed in the macropore of activated carbon, and their average diameter is $0.8{\mu}m$. The pore volume of activated carbon granule is $0.67m{\ell}/g$, and the pore volume of the sample including 21.6wt% of zeolite 4A crystal is $0.41m{\ell}/g$ decreasing the pore volume by 40% due to the crystallization of zeolite 4A crystals on the internal surface of activated carbon. The calcium ion exchange capacity of zeolite 4A-impregnated sample is 320mg $CaCO_3/g$ zeolite, and this value is almost the same as that of zeolite 4A powder. The crystal of zeolite 4A was not separated from the support of activated carbon granule in the course of ultrasonic dispersion. The adsorption isotherm of water on zeolite 4A-impregnated sample shows the intermediate shape between types, I and III. In addition, zeolite 4A-impregnated sample shows the hydrophilic and hydrophobic properties simultaneously.

• Journal of Life Science
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• v.18 no.6
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• pp.845-851
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• 2008

${\beta}-Lactamase$, secreted from Bacillus sp. J105 strain was purified to a single band on SDS-PAGE by ammonium sulfate precipitation, ion exchange column chromatography and gel-filtration. The molecular weight of the purified enzyme was 31 kDa on SDS-PAGE and its isoelectric point was 7.35. Optimal pH and temperature for enzymatic reaction were 5 and $40^{\circ}C$, respectively. As a result of total amino acid composition analysis of the purified enzyme, Gly and Ala were occupied 14.1 and 13.3 mole %, respectively. Km and Vmax value of purified enzyme were 1.33 mM and 0.36 mM/ml using ampicillin as a substrate, respectively.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.57-62
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• 2000

The proteoglycan, intracellular and extracellular, extracted from the liquid culture of Phellinus igniarius were purified and characterized. The mycelial productivity was proved to be better in shaking culture compared to standing culture. The productivity of intracellular proteoglycan of Phellinus igniarius appeared to be similar in two culturing methods. The standing culture of Phellinus igniarius produced 6 times as much extracellular proteoglycan compared to shaking culture. The proteoglycan were purified to a single peak by ion exchange chromatography(DEAE-cellulose) followed by gel filtration(Sepharose 2B). PIEPDG contained 79.0% total sugar and 7.2% protein. PIEPAG contained 56.7% total sugar and 40.8% protein. PIIPDG contained 64.8% total sugar and 17.4% protein. PIIPAG contained 56.9% total sugar and 41.5%n protein. The molecular weights of all the fractions were estimated to be above 100,000, from 134KDa of PIEPDG to 560 KDa of PIEPAG. The results of sugar analysis by HPLC showed that PIEPDG contains glucose only. The sugar part of PIIPDG and PIIPAG were consisted of glucose and inositol. The PIEPAG contained three kinds of monosaccharides, glucose, fructose and inositol.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.320-327
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• 2004

Three hundreds thirty two bacterial colonies which were able to degrade crude oil were isolated from soil sam­ples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its higher oil degrading ability, and this selected bacterial strain was identified as Acinetobactor sp. B2 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Acinetobactor sp. B2 was able to utilize various carbohydrates but did not utilize trehalose and mannitol as a sole carbon source. Acinetobactor sp. B2 showed a weak resistance to antibiotics such as kanamycin, streptomycin, tetracycline and spectinomycin, but showed a high resistance up to mg/ml unit to heavy metals such as Ba, Li, Mn, AI, Cr and Pb. The optimal growth temperature of Acinetobactor sp. B2 was $30^{\circ}C.$ The lipase produced by Acinetobactor sp. B2 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 60 kDa and condition for the optimal activity was observed at $40^{\circ}C$ and pH 10, respectively. The activation energy of lipase for the hydrolysis of p­nitrophenyl palmitate was 2.7 kcal/mol in the temperature range of 4 to $37^{\circ}C,$ and the enzyme was unstable at the temperature higher than $60^{\circ}C.$ The Michaelis constant $(K_m)\;and\;V_{max}$ for p-nitrophenyl palmitate were 21.8 uM and $270.3\;{\mu}M\;min^{-1}mg^{-1},$ respectively. This enzyme was strongly inhibited by 10 mM $Cd^{2+},\;Co^{2+},\;Fe^{2+},\;Hg^{2+},$ EDTA and 2-Mercaptoethalol.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.7-12
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• 1999

By SDS-polyacrylamide gel elcctrophoresis (SDS-PAGE) and immunoblot analysis that a protein with 66,000 daltons in size was recognized by P. aeruginosa anti-exotoxin A from P. sp. PY002. The yields of exotoxin A in P. sp. PY002 culture were influenced by the concentration of iron in the culture media. Increasing of the exotoxin A production and siderophore production was made slight increasing in the MKB medium. On the other hand, to clone the gene encoding the exoloxin A genomic library of P. sp. PY002 was constructed in pBluescript SK(+). From this library a exotoxin A homologous gene was isolated by immunological hybridization method using P. aemginosa anti-exoloxin A as a probe. Two putative clones were isolated and designated pETA23 and pETA42. Thc restriction analysis ol pETA42 demonstrated that thc 1760 bp insert contained one NcoI, PvuII, SstI, Kpnl and EcoRI site and three SmaI and HaeD sites.