• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.385-388
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• 1986

The reaction of cupric nitrate trihydrate with S-2-pyridyl thioates in acetonitrile was studied. The major products were the corresponding carboxylic acids and $[Cu(NO_3)(C_5H_4NS)(C_5H_5NS$)] (Complex A). Sometimes $[Cu(NO_3)(C_5H_4NS)(H_2O$)] was also obtained in addition to Complex A. When Complex A was recrystallized in dimethylsulfoxide, $[Cu(NO_3)(C_5H_4NS)(C_5H_5NS)$ {$(CH_3)_2SO$}$_2]{\cdot}2H_2O$ was crystallized. The structures of these copper complexes and the role of cupric nitrate in the hydrolysis of S-2-pyridyl thioates are discussed.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.622-626
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• 1991

Antioxygenic effects of browning reaction product(BRP) obtained from 2M L-ascorbic acid(AsA) solution by heating at $85^{\circ}C$ were investigated. BRP obtained from AsA solution(pH 2.30) without pH adjusting showed slightly antioxygenic effect. As heating time increased, powers of antioxygenic activity of BRP did not increase. Retained AsA after heating did not effect antioxygenic activity of AsA solution. After adjusting pH of AsA solution to 2.3, 4.0, 7.0, 9.0 and 11.5 respectively, BRP were obtained from these AsA solution by heating at $85^{\circ}C$ for 15 hrs. Among these BRPs, BRPs of pH 2.3 and 4.0 showed no antioxygenic effect, lower browning degree and higher retained AsA, but had stronger reducing power. While those of pH 7.0, 9.0 and 11.5 had stronger antioxygenic activity, higher browing degree and lower retained AsA, but showed weaker reducing power. After adjusting pH of AsA solution to 7.0, antioxygenic activities of BRP which was obtained from this AsA solution by heating respectively at $85^{\circ}C$ for 0, 3, 5, 10, 15 and 25 hrs increased in proportion to heating time.

• Korean journal of applied entomology
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• v.12 no.4 s.17
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• pp.153-155
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• 1973

1. 침파리의 동계사육 결과 평균온도 $23.7^{\circ}C$에서 유충기간 7일, 용기간 9.2일, 전산란기간 14.2일, 성충수명 23.3일이었다. 2. 5월부터 7월까지 사육온도 $25\pm1^{\circ}C$로 고정시켰을 때의 생육기간은 유충기간 8.0일, 용기간 5.3일, 전산란기간 11.7일, 성충수명 30.1일 이었다. 3. 용 개체중량은 5월-7월의 $25\pm1^{\circ}C$에서 13.3mg으로서 현저한 증가를 볼 수 있었다. 4. 전산란 기간중의 성충사망율은 습도 조절(R. H.)에 따라서 큰 차이를 보여주었으며 누대사육을위해서는 $55-65\%$의 R.H.를 유지할 필요가 있을 것으로 본다. 5. 성충의 산란율은 산란 시작후 제8-10일에 제일 높다.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.548-554
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• 1990

Temperature effects on the fluorescence emission spectra of 0.01 M Eu(III) ion with ClO$_4$, Cl$^-$, NO$_3$ were studied. Relative intensity change of hypersensitive band ($^5D0\; {\to}\;^7F_2$) and nonhypersensitive band ($^5D0 \;{\to}\;^7F_1$) was quite remarkable with temperature and ligand. The relative intensity change was interpreted as the change of formation constant and used to calculation the enthalpy change of $Eu(H_2O)_X^{3+}$+ to EuL(H$_2O)_{X-1}^{2+}$ complex. $\Delta{H}$ of $Eu(H_2O)_X^{3+}$ to EuCl(H$_2O)_{X-1}^{2+}$ was roughly 15 kJ/mol and temperature independent, but $\Delta{H}$ of EuNO$_3(H_2O)_{X-1}^{2+}$ was changed with temperature; -11 kJ/mol at 25$^{\circ}C$ and 47 kJ/mol at 250$^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.168-173
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• 2013

This study was carried out to develop and validate predictive models of E. coli O157:H7 growth. Growth data of E. coli O157:H7 in Paprika were collected at 12, 24, 30 and $36^{\circ}C$. The population increased into 3.0 to 3.8 log10 CFU/g within 4 days, then continued to increase at a slower rate through 10 days of storage at $12^{\circ}C$. The lag time (LT) and maximum specific growth rate (SGR) obtained from each primary model was then modeled as a function of temperature using Davey and square root equations, respectively. For interpolation of performance evaluation, growth data for a mixture of E. coli O157:H7 were collected at time intervals in paprika incubated at the different temperatures, which was not used in model development. Results of model performance for interpolation data demonstrated that induced secondary models showed acceptable goodness of fit. Relative errors in the LT and SGR model for interpolation data (18 and $27^{\circ}C$) was 100%, which show acceptable goodness of fit and validated for interpolation. The primary and secondary models developed in this study can be used to establish tertiary models to quantify the effects of temperature on the growth of E. coli O157:H7 in paprika.

• KSBB Journal
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• v.10 no.5
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• pp.568-574
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• 1995

To investigate the effect of pH on organic acid production by Anaerobiospirillum succiniciproducens, an anaerobic fermentation was carried out by maintaining the pH of the fermentation broth at 5.8, 6.0, 6.4, 6.8, and 7.2. At various pHs, the concentrations of cell were $1.0∼1.9g/\ell$ which were two to three times higher than those of the other worker's results, and the maximum was obtained at pH 5.8. Substrate consumption was increased by increasing the pH in the range of pH 6.0 to 6.8, while the sugar consumption rate at both pH 5.8 and 7.2 was very slow. The total amount of 2M $Na_2C0_3$ added for adjustment of pH change due to organic acid production was maximum at pH 6.8. Changes of conductivity of the fermentation broth was very simillar to those of 2M $Na_2C0_3$ added at various pHs. Therefore, it is suggested that determination of the amount of organic acid in a broth can be possible by measuring the conductivity. The maximum production yield of lactate based on glucose was 64% for pH 7.2 and 32% for pH 6.8, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.570-574
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• 2003

This study investigate the effects of starter cultures on the color stability of Chinese-style sausage. The samples were inoculated with $10^7cfu\;g^{-1}$ meat of either Staphylococcus carnosus or Staphylococcus xylosus. After mixing, curing at either $4^{\circ}C$ or $20^{\circ}C$ for 20 h and then drying at $50^{\circ}C$ for 5 h, the samples were then either vacuum packed or hung at $4^{\circ}C$ and $25^{\circ}C$ (85% R. H.). The pH, nitrite content, nitrosyl pigment content, metmyoglobin and L-, a-, b- values were measured. The pH value still remained above 6.0 during storage. Nitrite residue of all samples decreased after storage at $25^{\circ}C$ for 7 days. The samples inoculated with S. carnosus and S. xylosus had higher nitrite content (20.9-34.7 ppm) than the control (p<0.05). Samples inoculated with S. carnosus and S. xylosus had higher nitrosyl pigment content and lower metmyoglobin content than those of the control. The L- and b- values of all samples decreased but the a- values increased with storage time. The result suggested that S. carnosus and S. xylosus starter cultures be used to improve color stability of Chinese-style sausage.

• Electrical & Electronic Materials
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• v.6 no.6
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• pp.514-522
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• 1993

본 연구에서는 Ag/ 첨가에 의한 YB $a_{2}$C $u_{3}$ $O_{7-{\delta}}$산화물의 초전도 특성 변화를 조사하였다. Ag가 첨가된 YB $a_{2}$C $u_{3-x}$A $g_{x}$ $O_{7-{\delta}}$ 산화물 시료를 만들고 이 시료들에 대한 X-ray 회절분석, IR흡수 스펙트럼분석, 임계온도(Tc)측정 및 자화(M-H)특성 측정등을 통하여 제조된 시료의 물리적 성질을 조사하였다. X-ray 회절실험 결과로 부터 x.leq.0.03인 경우에는 YB $a_{2}$C $u_{3-x}$A $g_{x}$ $O_{7-{\delta}}$가 단일상의 물질로 존재하고 x가 증가함에 따라 불순물상( $Y_{2}$ $O_{3}$, 순Ag)이 나타남을 알 수 있었다. IR흡수의 실험결과에서 Cu와 치환되어 들어간 Ag의 Ag-O 결합에 의한 흡수 스펙트럼(670$cm^{-1}$ /)이 관측되었다. 실험 결과로 부터 치환된 Ag의 양 x가 증가함에 따라 Tc가 조금씩 낮아지는 경향이 있었으며 자화의 세기 및 임계자장( $H_{C2}$)은 급격히 감소함을 알 수 있었고 또 M-H특성곡선에는 히스테리시스 특성이 나타났다.났다..났다.다.

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.64-70
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• 1995

The authors have studied crystallographic and magrletic properties of $NdFe_{10.7}TiM_{0.3}(M=B,\;Ti)$ by X-ray diffraction, VSM magnetometer, and Mossbauer spectrometer. The Alloys were prepared by arc-melting under argon atmosphere. The $NdFe_{10.7}TiM_{0.3}$ has pure single phase, whereas the $NdFe_{10.7}Ti_{1.3}$ contains some $\alpha-Fe$, from powder X-ray diffractometry. The $NdFe_{10.7}TiM_{0.3}$ has the $ThMn_{12}$-type tetragonal structure with $a_{0}=8.587\;{\AA}\;and\;c_{0}=4.788\;{\AA}$. The Curie temperature ($T_c$) is $570{\pm}3\;K$ from $M\"{o}ssbauer$ spectroscopy performed at various temperatures ranging from 13 to 770 K. Each spectrum of below $T_c$ was fitted with five subspectra of Fe sites in the structure ($8i_{1},\;8i_{2},\;8j_{1},\;8j_{2}\;and\;8f$). The area fraction of the subspectra at room temperature are 16.4, 8.2, 14.8, 21.3 and 39.3 %, respectively. Magenetic hyperfine fields for the Fe sites decrease in the order, $H_{hf}(8i)>H_{hf}(8j)>H_{hf}(8f)$.

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.323-332
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• 1988

The bacteria containing urease convert each molecule of urea into two molecules of ammonia and one molecule of carbon dioxide gas. Bacterial electrodes have been constructed by immobilizing the Proteus vulgaris on an ammonia and a carbon dioxide gas-sensors, and were investigated for the effects of pH, temperature, buffer solution, bacterial amounts and interferences, and life time. NH3-bacterial electrode based on ammonia gas-sensor had linearity in the range of $7.0{\times}10^{-4}\;-\;3.0{\times}10^{-2}$M urea in pH 7.4, 0.05M phosphate buffer at $25^{\circ}C$ with a slope of 116.7 mV/decade. While $CO_{2-}$bacterial electrode based on carbon dioxide gas-sensor bad linearity in the range of $7.0{\times}10^{-4}\;-\;5. 0{\times}10^{-2}$M urea in pH 7.0, 0.1M phosphate buffer at $30^{\circ}C$with a slope of $45.4{\times}45.7mV/decade$. As the clinical application, urea in urine was determined by these devices and this result was compared with spectrophotometric method. Consequently, these electrodes could be used for the analysis of many samples because of simplicity, rapidity and convenience of the experimental procedure.