• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.1985-1988
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• 2006

The polymeric membrane electrodes based on urea derivative as an ionophore were prepared and studied for the iodide-ion selective electrode. This membrane exhibits a linear stable response over a wide concentration range ($1.0\;{\times}\;10^{-5}\sim1.0\;{\times}\;10^{-2}$) with a slope of -57.7 mV/decade, a detection limit of log[$I^-$] = -5.63, and a selectivity coefficient for iodide against perchlorate anion (log$K^{pot}_{I^-,j}$ = -1.42). The selectivity series of the membrane gives the follow as $I^-$ > $SCN^-$, $Sal^-$ > $ClO_4^-$ > $NO_3^-$ > $Br^-$ > $NO_2^-$ > $Cl^-$ > $F^-$. The proposed electrode showed good selectivity and response for iodide anion over a wide variety of other anions in pH 5.0 buffer solutions.

• Journal of Nuclear Fuel Cycle and Waste Technology
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• 제1권1호
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• pp.65-73
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• 2013

Temperature-dependent hydrolysis behaviors of aqueous U(VI) species were investigated with time-resolved laser fluorescence spectroscopy (TRLFS) in the temperature range from 15 to $75^{\circ}C$. The formation of four different U(VI) hydrolysis species was measured at pHs from 1 to 7. The predominant presence of $UO{_2}^{2+}$, $(UO_2)_2(OH){_2}^{2+}$, $(UO_2)_3(OH){_5}^+$, and $(UO_2)_3(OH){_7}^-$ species were identified based on the spectroscopic properties such as fluorescence wavelengths and fluorescence lifetimes. With an increasing temperature, a remarkable decrement in the fluorescence lifetime for all U(VI) hydrolysis species was observed, representing the dynamic quenching behavior. Furthermore, the increase in the fluorescence intensity of the further hydrolyzed U(VI) species was clearly observed at an elevated temperature, showing stronger hydrolysis reactions with increasing temperatures. The formation constants of the U(VI) hydrolysis species were calculated to be $log\;K{^0}_{2,2}=-4.0{\pm}0.6$ for $(UO_2)_2(OH){_2}^{2+}$, $log\;K{^0}_{3,5}=-15.0{\pm}0.3$ for $(UO_2)_3(OH){_5}^+$, and $log\;K{^0}_{3,7}=-27.7{\pm}0.7$ for $(UO_2)_3(OH){_7}^-$ at $25^{\circ}C$ and I = 0 M. The specific ion interaction theory (SIT) was applied for the extrapolation of the formation constants to infinitely diluted solution. The results of temperature-dependent hydrolysis behavior in terms of the U(VI) fluorescence were compared and validated with those obtained using computational methods (DQUANT and constant enthalpy equation). Both results matched well with each other. The reaction enthalpies and entropies that are vital for the computational methods were determined by a combination of the van't Hoff equation and the Gibbs free energy equation. The temperature-dependent hydrolysis reaction of the U(VI) species indicates the transition of a major U(VI) species by means of geothermal gradient and decay heat from the radioactive isotopes, representing the necessity of deeper consideration in the safety assessment of geologic repository.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.47-47
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• 2009

The photoconductive $CdGa_2Se4$ layer has been investigated using photocurrent (PC) spectroscopy as a function of temperature. Three peaks corresponding to the band-to-band transitions were observed in the PC spectra for all temperature ranges. Also, contrary to our expectation, the PC intensities decreased with decreasing temperatures. From the relation of log $J_{ph}$ vs 1/T, where $J_{ph}$ is the PC density, two dominant levels by the exponential variation of the PC with varying temperature were observed, one at high temperatures and the other at low temperatures.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.556-562
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• 2007

A total of 126 crossbred weanling pigs (average body weight of $6.3{\pm}0.3$ kg) were used to investigate the effect of chito-oligosaccharide (COS) on growth performance, nutrient digestibility, pH of gastro-intestinal tract (GI), intestinal and fecal microflora of young piglets. Pigs were allocated to three dietary treatments based on body weight and gender in a single factorial arrangement. Treatments were control (No COS), T1 (0.2% COS during starter (6-13 kg) and 0.1% COS during grower (13-30 kg) phases, and T2 (0.4% COS during starter (6-13 kg) and 0.3% COS during grower (13-30 kg) phases, respectively. Each treatment had 3 replicates and 14 pigs were raised in each pen. COS is a low molecular weight water-soluble chitosan that can be obtained from chitin of the crab shell after deacetylation with concentrated sodium hydroxide at high temperature and then further decomposition by chitosanase enzyme in the presence of ascorbic acid. For the starter and grower periods, there were no significant differences (p>0.05) in average daily gain (ADG) and feed to gain ratio among treatments. However, during the overall period (6-30 kg), T2 showed better (p<0.05) feed to gain ratio than other treatments. A digestibility study was conducted at the end of grower phase which showed improvement (p<0.05) in DM and crude fat digestibility in T2 over the control. At 25 kg body weight, 6 pigs per treatment (2 per replicate) were sacrificed to determine the effect of diets on pH and microbial count at different sections of the GI tract. The pH of the cecal contents in pigs fed 0.1% COS was higher (p<0.05) than in the other treatments. Total anaerobic bacterial number increased from cecum to rectum in all treatments. The weekly total bacterial counts showed higher (p<0.05) in feces of pigs fed COS than that of untreated pigs at the $8^{th}$ week. The number of fecal E. coli in untreated pigs at $4^{th}$ wk was 7.35 log CFU/g compared to 6.71 and 6.54 log CFU/g in 0.1 and 0.3% COS-treated pigs, respectively. Similarly, at $8^{th}$ wk, fecal clostridium spp. were lower in pigs fed 0.3% COS (5.43 log CFU/g) than in untreated pigs (6.26 log CFU/g). In conclusion, these results indicated that chito-oligosaccharide could improve feed efficiency in young pigs and inhibited the growth of harmful bacteria.

• 한국도서관정보학회지
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• 제8권
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• pp.127-154
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• 1981

Today's complicated society with a rapid change needs more objective and accurate data for the better managerical decisions and the prospect for the future other than the intuition or subjective experience by men themselves. These data can't be extracted without the analysis of actual data by a n.0, pplying any of mathematical techniques. One of these mathematical techniques, called bibliometrics has been newly developed in the field of library and information science to extract the objective data for the better services through the library operations. The Beadford's Law, one important law in bibliometrics has provided rather scientific and objective basis on the more valid building of library collection within the constraints of budget. The purpose of the study is to investigate the theory of the Bradford's Law, to clarify the possible areas of its a n.0, pplication, and to discern some problems in doing so. The results of the study can be summarized as follows; (1) There is certain difference between the graphical formulation and verbal formulation of Bradford's Law. But this law is very useful for the field of library and information science, owing to the flexibility of the a n.0, pplication of the law in the field. (2) The minimal nucleus can consist of a single periodical only if j, the number of relevant papers in the most productive journals is greater than Z/2. On the other hand, if j is less than or equal to Z/2, then the minimal nucleus will consist of 2 or more periodicals. (3) It is possible to design the most compact selection of scientific periodicals covering any specified percentage P among the total periodicals by using the formulation, log n=Plog N+(1-P)logs, or Nlog N/s=P center dot N log N/s. (4) If there is need to provide all the articles needed by users the given budget, the library can purchase the proper number of journals, by using the formulation, f center dot AN=An+PN (log N/s-logn/s). (5) In the building of the library collection based on the decreasing ratio of use, the library can subscribe to the proper number of journals according to the satisfactory degree of the need, by using the formulation, f=Nu+uNlogN/S-uNlogn/s / nNlogN/s = 1+logN/m /logN/s (6) If the order of valuable journals is decided according to the frequency of being cited, the order can't always represent the value. (7) The evaluation criteria for the journals with high value, but less cited should be made a further study.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.300-304
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• 1993

Genetic transformation of streptomyces gaespitosus by plasmid plJ 702 was camied out. Optimal conditions for the protoplast preparation of streptomyces casepitosus, its regeneration, and its transformation by plJ 702 were evaluated. Addition of 2% glycine to the culture broth was optimal for protoplast yield. Formation and regeneration of protoplasts were most efficient when the mycelium were harvested at between late log and stationary growth phase. The regeneration frequency of the protoplasts was 15% when the protoplats were regenerated on R2YE agar media containing 0.5M sucrose. Under the best condition for protoplats (M.W. 4,000) treatment for 2 minutes.

• 전자통신동향분석
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• 제38권4호
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• pp.81-94
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• 2023

The increased adoption of open source security management in supply chains is gaining worldwide attention. In particular, as security and threatening situations, such as solar winds, Kaseya ransomware, and Log4j vulnerability, are becoming more common in supply chains using software (SW)-defined networks, SW bills of materials (SBOMs) for SW products should be prepared to protect major countries like the United States. An SBOM provides SW component information and is expected to become required for SW supply chain management. We focus on SW supply chain management policies and SBOM trends in major countries and private organizations worldwide for safe SW use and determine the current status of Korea and ETRI's open source SW supply chain management trends.

• 한국식품영양과학회지
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• 제41권11호
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• pp.1632-1638
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• 2012

치콘의 미생물학적 안전성을 확보하기 위해 50 ppm 이산화염소수와 5 kJ/$m^2$ UV-C 및 2 kGy 전자빔 조사 병합처리에 따른 저장 중 미생물 수 및 품질 변화를 $4{\pm}1^{\circ}C$에서 11일 동안 저장하면서 측정하였다. 이산화염소수와 UV-C 병합처리 후 치콘의 총 호기성 세균 수는 대조구와 비교하여 1.49~2.92 log CFU/g, 효모 및 곰팡이는 1.63~1.78 log CFU/g의 감소를 보였다. 반면에, 이산화염소수와 2 kGy 전자빔 병합처리구의 경우 총 호기성 세균은 저장기간 동안 검출되지 않았으며, 효모 및 곰팡이 역시 11일 간의 저장기간 동안 나타나지 않았다. 이산화염소수와 전자빔의 병합처리는 대조구와 비교하여 치콘의 저장 중 Hunter 색도 값에 부정적 영향을 미치지 않았다. 관능검사에 있어서도 저장기간 동안 대조구와 비교 시 유의적인 차이가 없는 것으로 나타났다. 따라서 본 연구결과, 이산화염소수와 전자빔 조사의 병합처리가 치콘의 저장 중 오염될 수 있는 위해미생물의 감소와 외관적 품질유지에 효과적인 살균처리 기술이라고 판단된다.

• 한국물환경학회지
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• 제22권4호
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• pp.672-677
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• 2006

Ozone/UV combined process is an effective technique to enhance generation of OH radical which is non-selective and powerful oxidant. The objective of this study is to evaluate the inactivation rates of B. subtilis spores by three candidate processes (ozone alone, UV alone, ozone/UV combined processes) at 4 and $20^{\circ}$ and to investigate the effects of OH radical on inactivation of B. subtilis spores. On the UV alone process, required UV dosages for lag phase and 3-log inactivation of B. subtilis spores were determined as $8.9mJ/cm^2$ and $47mJ/cm^2$. However, the inactivation of B. subtilis spores didn't occured beyond 4.5-log inactivation despite increasing UV dose. The inactivation of B. subtilis spores by ozone alone and ozone/UV combined process was investigated with ozone CT (Concentration of disinfectant ${\times}$ Contact time) concept. As a result, inactivation of B. subtilis spores by ozone/UV combined process was faster than by ozone alone, and especially $CT_{lag}$ value B. subtilis spores in the presence and absence of t-BuOH, OH radical scavenger, was investigated to evaluate effects of OH radical formed during ozone/UV combined process. We found that OH radical plays important roles on inactivation of B. subtilis spores.

• 한국식품저장유통학회지
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• 제15권6호
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• pp.922-926
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• 2008

UV-C 조사가 국내에 유통되고 있는 수입 건어포류의 저장 중 미생물학적 변화와 품질에 미치는 영향을 연구하였다. UV-C 조사량은 5, 10, $20\;kJ/m^2$으로 처리하여 대조구와 비교하였다. 조사시간은 5분 33초, 11분 6초, 22분 12초를 사용하였다. UV-C 조사에 의한 건어포류에 존재하는 오염된 미생물의 감소는 $20\;kJ/m^2$ 처리에서, 쥐포는 호기성 세균과 효모 및 곰팡이에서 각각 0.82, 1.23 log CFU/g, 문어포는 각각 1.20, 1.01 log CFU/g이었다. 또한 저장 중 대조구 대비 초기 감균 효과를 유지하였고, 조사선량이 증가함에 따라 미생물이 더 감소하였다. UV-C 조사된 시료에 대한 Hunter L, a, b 값을 측정한 결과 저장 중 시료의 색도에 있어서 조사선량에 따른 유의적인 차이는 없었다. 따라서 본 연구결과, UV-C 조사 처리가 수입 건어포류의 미생물 생육 억제 및 품질 유지의 가능성을 확인하였다.