• Journal of Surface Science and Engineering
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• v.25 no.5
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• pp.215-221
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• 1992

This research is aimed at developing(110) preferred TiS2 cathode films and glass typed solid electro-lytes which have high ionic migrations and low electron conductivities for thin secondary solid batteries. To obtain preferred oriented TiS2 thin films on a substrate by CVD method using TiCl4 and H2S gases three factors of heating temperature, inner pressure of furnace and TiCl4/H2S gas mole fraction were ex-amined systematically. To obtain solid films of Li2O-B2O3-SiO2 electrolytes by r.f. sputtering for thin proto-type batteries of Li/Li2O-B2O3-SiO2TiS2, sputtering conditions were examined. TiS2 cathode films showed columnar structure, namely c axis oriented parallely. At low pressure of reaction chamber and low heating temperature, surface of smooth TiS2 films couldd be obtained. Ionic conductivity of Li2O-B2O3-SiO2 films manufactured by r.f. magnetron sputtering were 3$\times$10-7$\Omega$-1cm-1 and electron conductivities were 10-11$\Omega$-1cm-1. Open cell voltage of thin lithium batteries were 2.32V with a designed prototype cell.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.334-339
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• 2019

A procedure based on high-performance liquid chromatography (HPLC) is described to determine ${\beta}-carotene$ in infant formulas. The method for ${\beta}-carotene$ analysis was performed on a C18 reversed-phase column using acetonitrile/methanol/dichloromethane (6:1:3, v/v/v) as a mobile phase. ${\beta}-Carotene$ was determined in HPLC with photo diode array (PDA) detector. The parameters of validation were specificity, linearity, LOD, LOQ, accuracy, precision and repeatability. The specificity was confirmed by the retention time and the linearity ($R^2$), which was over 0.999 in the range of 0.125~2 mg/L. The detection and quantification limits were 0.064 and 0.193 mg/L, respectively. The accuracy and precision of this method using an STD spiked sample were 80~119% and 1.02~2.05% respectively. The method was applied to the analysis of various infant formula and follow-up formulas products containing ${\beta}-carotene$, and all the products contained acceptable levels of ${\beta}-carotene$ for nutrition labeling.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.372-372
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• 2014

반도체 검출기는 입사되는 X선 에너지에 의하여 이온화되어 발생하는 전자 전공쌍을 수집함으로 방사선 정보를 확인하는 선량계로써 많은 연구와 활용이 이루어지고 있다. 하지만, X선 에너지에 의하여 반도체 검출기에서 발생하는 전기적 신호량이 높지 않기 때문에 누설 전류의 저감이 필수적이다. 누설 전류를 저감시키기 위한 방안으로 반도체 층과 전극 층의 Schottky Contact 구조의 설계, Insulating Layer의 사용, 높은 비저항의 반도체 물질 연구 등이 이루어지고 있다. 하지만, 기존에 누설 전류 저감을 위하여 Insulating Layer를 전극층과 반도체 층 사이에 형성하는 연구에 있어서 Insulating Layer와 반도체 층의 계면 사이에서 발생하는 Charge Trapping으로 인하여 생성되는 신호의 Reproducibility 저하, 동영상 적용의 제한 등의 문제점을 겪어왔다. 이에 본 논문에서는 누설 전류를 저감시킴과 동시에 Charge Trapping의 최소화를 이루기 위하여 Insulating Layer의 두께 최적화 연구를 수행하였다. 본 연구에서 사용한 Insulating Layer는 검출기 표면에 입사하는 X선 정보 손실을 최소화 시키는 동시에 누설 전류와 Charge Trapping을 최소화 시키는 방법으로써 CVD방법으로 검출기 표면에 균일하게 Insulating Layer를 코팅하였다. Insulating 물질은 Parylene을 사용하였으며, 그 중 온도, 습도 등 외부환경에 영향을 적게 받는 type C를 사용하였다. 증착에 사용한 장비의 진공도는 Torr로 설정하여 증착되는 Parylene의 두께가 약 $0.3{\mu}m$가 되게 하였으며, 실험에는 반도체 물질 PbO를 사용하였다. Parylene의 절연 특성은 Dark Current와 Sensitivity를 측정한 SNR을 이용하여 Parylene코팅이 되지 않은 동일 반도체 검출기와의 신호를 비교하였으며 또한 Parylene를 다층 제작한 검출기의 수집 신호량을 비교하였다. 제작한 검출기의 X선 조사 시의 수집 전하량 측정 결과, 100 kVp, 100mA, 0.03s의 X선 조건에서 $1V/{\mu}m$의 기준 시, Parylene를 코팅하지 않은 PbO 검출기의 Dark current는 0.0501 nA/cm2, Sensitivity는 0.6422 nC/mR-cm2, SNR은 12.184이었으며, Parylene단층의 두께인 $0.3{\mu}m$로 증착된 시편의 Dark current는 0.04097 nA/cm2, Sensitivity는 0.53732 nC/mR-cm2으로 Dark current가 감소되고 sensitivity도 감소하였지만 SNR은 13.1150으로 높아진 것을 확인할 수 있었다. Perylene이 $0.6{\mu}m$로 증착된 시편의 경우, Dark Current는 0.04064 nA/cm2, Sensitivity는 0.31473 nC/mR-cm2, SNR은 7.7443으로써 Insulating Layer가 없는 시편보다 SNR이 약 40% 낮아진 것을 확인할 수 있었다. Parylene이 $0.9{\mu}m$로 증착된 시편의 경우 Dark current는 0.0378 nA/cm2, Sensitivity 0.0461 nC/mR-cm2로 Insulating Layer가 없는 시편에 비해 SNR은 약 1/12배 감소한 1.2196이었고, Parylene이 $1.2{\mu}m$로 증착된 시편의 SNR은 1.1252로서 더 감소하였다. 따라서 Parylene을 다층 코팅한 검출기일수록 절연 효과의 영향이 커짐으로써 SNR 비교 시 수집되는 신호량이 줄어드는 것을 확인하였다. 반도체 검출기의 누설 전류를 저감시킴과 동시에 신호 수집율에 영향을 최소화시키기 위하여 Insulating Layer의 두께를 적절하게 설정하여 적용하면 Insulating Layer가 없는 검출기에 비해 누설전류를 최소한으로 줄일 수 있고 신호 검출효율이 감소하는 것을 방지할 수 있을 것이라 사료된다.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1299-1305
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• 1996

The rat thoracic aorta was harvested to determine whether either hyperkalemla or hypothermia impairs the endothelium-dependent re axation of the vascular smooth muscle. Isolated thoracic aorta segments were studied in five groups(n=10 in each group). In group I(control), the isolated aortic seglnents were suspended in organ bath without any intervention. In group ll(endotheilum removAl). the endothelium of the aortic segment was removed by gentle rubbing of the intimal surface with a pair of forceps. In group III(457), IV(4mST), and V(3757), the aortic segments were exposed for 45minutes to 4$^{\circ}C$ St. Thomas hospital cardioplegic solution(57 : NaCl, 144.3; KCI, 19.6, MgCl:, 15.7 : CaCl, 2.2 mmol/L).4$^{\circ}C$ modified St. Thomas hospital cardioplegic solution(NaCl, 144.3 : KCI. 140.0 : MgCl:, 15.7; CaCl:. 2.2 mmol/L). and 37$^{\circ}C$ 57, before suspending in the organ bath, respectively. Then, aorta segments were suspended in organ baths(physiologic salt solution, 37$^{\circ}C$, 95% oxygen and 5% carbon dioxide) for Isometric tension recording. The vasodilatation to acetylcholine (10-2 to 10-2mol/L) was not impaired in control, 457, 4mST, nd 3757 groups. The vasodilatation to acetylcholine was impaired in endothelium removal group. The vasodilatation to sodium nitroprusslde (10-2 to 10-2 mol/L) was not impaired in all groups. In conclusion, both hyperkalemia and hypothermia do not alter irreversibly the function of the rondothelium of the thoracic aorta of the rat.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.323-330
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• 1998

Cyclodextrin glucanotransferase (CGTase) was purified from the culture broth of the Bacillus firmus var. alkalophilus, using ultrafiltration, starch adsorption/desorption, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephacryl HR-100. The molecular weight of the purified enzyme was determined as 77,000 by SDS-PAGE. The optimum pH and temperature for the CD synthesis were 6.0 and 5$0^{\circ}C$, respectively. The activity of this enzyme was stably kept at the range of pH 6.0～9.5 and up to 5$0^{\circ}C$. However, in the presence of $Ca^{2+}$, the optimum temperature for CD synthesis was shifted 55~6$0^{\circ}C$ and this enzyme was stable up to 6$0^{\circ}C$ because of the stabilizing effect of $Ca^{2+}$. The purified CGTase produced CDs with high conversion yields of 45~51% from sweet potato starch, com starch and amylopectin as substrate, especially, and the product ratio of $\beta$-CD to ${\gamma}$-CD was obtained at range of from 5.8:1 to 8.4:1 according to the kind of substrate. The purified enzyme produced mainly $\beta$-CD without accumulation of $\alpha$-CD during enzyme reaction using various starches as the substrate, indicating that the purified enzyme is the typical $\beta$-CGTase. The purified CGTase produced 25 g/l of CDs from 5.0% (w/v) liquefied com starch and the conversion yield of CDs was 50%, and the content of $\beta$-CD was 84% of total CDs after 8 hours under the optimum reaction condition.ion.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.257-267
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• 1997

Fruit bodies similar to the Phellinus sp. residing on the mulberry were collected at Yang-yang in Kang-won-do province and one strain of Phellinus sp. was isolated from the fruit bodies. For mass production of the isolated mycelia in a submerged culture, the culture conditions, medium composition, and the effect of various culture systems on the mycelial growth, were investigated. The morphological characteristics of the fruit body were as follows: covered with blackish to black and rough, lower surface with yellowish-brown to dull-brown and smooth, 5-7 cm thick and hard woody. Also, the pure cultured mycelia showed yellowish-brown color, capability of purplish-brown pigment production on the PDA plate media, no-formation of clamp-connection, much binding branch, and enzyme activities such as laccase, tyrosinase and peroxidase. Therefore, pure cultured strain was identified to be Phellinus sp. In the flask culture, the optimum culture conditions for the mycelial production were obtained after cultivation of 8 days at inoculum level of 5%(v/v), media volume of 70 mL, 150 rpm, initial pH 6, and temperature of $30^{\circ}C$. Optimum medium composition from the response surface analysis were determined to be glucose 12.12 g/L, sucrose 12.12 g/L, yeast extract 11.15 g/L, malt extract 11.15 g/L, $KH_2PO_4$ 0.855 g/L and $CaCl_2$ 0.855 g/L. The production of the mycelia after 4 and 8 days of cultivation was 1.95 and 9.89 g/L, respectively. The maximum specific growth rate and productivity were $0.020\;hr^{-1}$ and 1.25 g/L/day, respectively. Among the three different culture systems for the growth of mycelia, the maximum mycelial dry weight of 7.5 g/L was obtained after cultivation of 4 days in the air-lift fermentor under aeration rate of 2.5 vvm. The maximum specific growth rate and productivity were $0.033\;hr^{-1}$ and 1.9 g/L/day, respectively, which were about 1.7 and 4.2 times higher than those of flask culture.

• Korean journal of food and cookery science
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• v.7 no.1
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• pp.15-25
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• 1991

The effects of lactic acid bacteria on the chemical and microbial changes of fermented kimchi at various temperatures were studied. Kimchi was homogenized and was sterilized by ultra violet, then Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici, Lactobacillus brevis and the mixture of there bacteria inoculated on sterilized kimchi, respectively. The measurement of pH and total acidity, quantitative analysis of volatile organic acids and nonvolatile organic acids by gas chromatography were investigated while inoculated kimchi were fermented at $30^{\circ}C$, $21^{\circ}C$, $14^{\circ}C$ and $7^{\circ}C$. Sample I (original kimchi homogenate), Sample III (inoculated with Leuconostoc mesenteroides) and Sample Ⅵ (inoculated with mixed lactic acid bacteria) were alike in that changes of pH and total acidity and especially, these phenomena were prominent at $14^{\circ}C$. Formic, acetic and heptenoic acid as volatile organic acid were detected by GC, and these acids formed mainly by Leuconostoc mesenteroides and lactobacillus brevis. Sample III was more higher content than other samples at $14^{\circ}C$. As nonvolatile organic acid, lactic acid in all samples, citric acid in sample III at $21^{\circ}C$and $14^{\circ}C$, succinic acid in sample I at $30^{\circ}C$, $21^{\circ}C$, $14^{\circ}C$ and sample V at $30^{\circ}C$ were detected by GC.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.24-37
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• 1991

We synthesized the binuclear Tetradentate Schiff base nickel(II) and copper(II) complexes ; [Ni(II)$_2$(SMPO)$_2$(L)$_2$], [Ni(II)$_2$(SPPD)$_2$(L)$_2$] and [Cu(II)$_2$(SMPD)$_2$] and [Cu(II)$_2$(SPPD)$_2$] (where, L : Py, DMSO and DMF). We identified the structure of these complexes by elemental analysis, IR-spectrum, T.G.A, D.S.C and ESR measurements. According to the results of cyclic voltammetry and DPP measurements in aprotic solvent included 0.1M TEAP as supporting electrolyte, we knew that diffusional controlled redox process of one step with one electron was irreversible process in 0.1M TEAP-Py solution. Also it was reversible or quasi reversible process in 0.1M TEAP-DMSO solution and reversible or E.C reaction mechanism in 0.1M TEAP-DMF solution at mononuclear complexes ; [Cu(II)(SOPD)] and [Ni(II)(SOPD)(L)$_2$]. But, we knew that diffusional controlled redox process of two step for one electron of binuclear complexes was as follows. The values of redox potential for dimeric complexes in 0.1M TEAP-L solution (where, L ; Py, DMSO and DMF) with scan rate 100mV/sec.

• Food Science and Preservation
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• v.16 no.2
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• pp.223-229
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• 2009

The effects of 0.01%(w/v) chitosan-ascorbate(CA) and 10 ppm morea on the number of total microbes, Escherichia coli levels, and growth of food poisoning bacteria in dombaeki during storage at $10^{\circ}C$ over 6 days were investigated. Total microbes in meat, cartilage, and skin of untreated samples increased by 4.24, 3.81, and 2.20 logs compared to the zero timepoint, respectively, but, in CA-treated samples, counts fell by 2.66, 2.37, and 1.24 logs. Total microbial levels in morea-treated meat, cartilage, and skin showed similar tendencies but the effects were slightly less than seen in CA-treated samples. E. coli numbers in CA-treated meat, cartilage, and skin stored for 6 days decreased by 1.69, 1.25, and 1.52 logs respectively, compared with control samples. Morea-treated samples showed similar falls, but the effects were again slightly less than seen after CA-treatment. Both Salmonella and Vibrio parahaemolyticus were detected in untreated meat stored for 3 or 6 days. Food poisoning bacteria were found in both untreated and morea-treated samples stored over 6 days. However, no such bacteria were detected in CA-treated samples. Also, CA-treated meat, cartilage, and skin showed low degrees of degeneration. Thus, CA treatment enhanced shelf-life and dombaeki quality by inhibiting microorganism growth and tissue breakdown during storage.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.98.2-98.2
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• 2010

$CuInS_2$ thin films were synthesized by sulfurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furnace annealing at temperature 200[$^{\circ}C$]. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_2$ thin films with non-stoichiometry composition. $CuInS_2$ thin film was well made at the heat treatment 200[$^{\circ}C$] of SLG/Cu/In/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1 : 1 : 2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and hall measurement system. At the same time, carrier concentration, hall mobility and resistivity of the thin films was $9.10568{\times}10^{17}$ [$cm^{-3}$], 312.502 [$cm^2/V{\cdot}s$] and $2.36{\times}10^{-2}$ [${\Omega}{\cdot}cm$], respectively.