• 한국광물학회지
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• 제31권4호
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• pp.235-248
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• 2018

본 연구는 제올라이트 Y (Si/Al = 1.56)에서 $Cs^+$ 이온 교환에 $Ca^{2+}$ 이온의 경쟁 양이온 효과를 연구하기 위해 수행되었다. 완전히 탈수되고 부분적으로 $Cs^+$ 이온으로 교환된 3개의 제올라이트 Y(Si/Al = 1.56)의 단결정은 혼합이온교환 용액을 사용하여 흐름법으로 제조되었으며, 전체 농도가 0.05 M인 이온교환용액의 $CsNO_3:Ca(NO_3)_2$ 몰비는 1 : 1 (Crystal 1), 1 : 100 (Crystal 2) 및 1 : 250 (Crystal 3)이다. 이온교환된 단결정을 723 K에서 2일 동안 $1{\times}10^{-4}Pa$로 진공 탈수시켰으며, 결정구조는 100(1) K에서 입방공간군 $Fd{\bar{3}}m$을 사용하여 단결정 싱크트론 X선 회절법으로 해석하고 구조를 정밀화하였다. Crystal 1, 2 및 3의 단위세포당 화학식은 ${\mid}Cs_{21}Ca_{27}{\mid}[Si_{117}Al_{75}O_{384}]-FAU$, ${\mid}Cs_2Ca_{36.5}{\mid}[Si_{117}Al_{75}O_{384}]-FAU$ 및 ${\mid}Cs_1Ca_{37}{\mid}[Si_{117}Al_{75}O_{384}]-FAU$이다. 3개의 결정 모두에서, $Ca^{2+}$ 이온은 D6Rs 내의 site I을 우선적으로 점유하고 있으며 나머지는 site I', II' 및 II를 점유하고 있다. 한편 주어진 이온교환용액의 초기 $Cs^+$ 이온의 농도에 따라 $Cs^+$ 이온의 분포에 중요한 차이가 관찰되었다. Crystal 1에서는 $Cs^+$ 이온이 site II', II, III와 III'에 위치하고 있으며, Crystal 2에서는 site II, IIIa, IIIb에 위치하고 있다. Crystal 3에서는 $Cs^+$ 이온은 site IIIa 및 IIIb에만 위치하고 있다. 초기 $Ca^{2+}$ 이온의 농도가 증가하고 $Cs^+$ 이온의 농도가 감소에 따라 $Cs^+$ 이온의 교환정도는 28.0에서 2.7과 1.3 %로 급격히 감소하였다.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3421-3430
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• 2021

Spherical NaI(Tl) detectors are used in gamma-ray spectrometry, where the gamma emissions come from the nuclei with energies in the range from a few keV up to 10 MeV. A spherical detector is aimed to give a good response to photons, which depends on their direction of travel concerning the detector center. Some distortions in the response of a gamma-ray detector with a different geometry can occur because of the non-uniform position of the source from the detector surface. The present work describes the calibration of a NaI(Tl) spherical detector using both an experimental technique and a numerical simulation method (NSM). The NSM is based on an efficiency transfer method (ETM, calculating the effective solid angle, the total efficiency, and the full-energy peak efficiency). Besides, there is a high probability for a source-to-detector distance less than 15 cm to have pulse coincidence summing (CS), which may occur when two successive photons of different energies from the same source are detected within a very short response time. Therefore, γ-γ ray CS factors are calculated numerically for a ¹⁵²Eu radioactive cylindrical source. The CS factors obtained are applied to correct the measured efficiency values for the radioactive volumetric source at different energies. The results show a good agreement between the NSM and the experimental values (after correction with the CS factors).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.37-40
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• 2000

This paper has been studied on characteristics of organic light-emitting device with various cathode materials. These catode materials were Al：Li(5%), Al, Cu, CsF/Al. And in these devices, HTL(hole transfer layer) was TPD and EML(emitting layer) was Alq$\sub$3/. We studied the I-V characteristics for each device. And then, the turn-on voltage of device for Al-Li(5%), Al, Cu, CsF/Al cathode were 7, 9, 13, 3V respectively. So, the CsF/Al cathode is superior to other cathode materials for I-V characteristics.

• Parasites, Hosts and Diseases
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• 제56권1호
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• pp.41-48
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• 2018

The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.

• 한국식품위생안전성학회지
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• 제35권1호
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• pp.31-36
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• 2020

장과류의 방사능 안전성 확보를 위해 2016년부터 2018년까지 경기도 내 유통 중인 장과류 및 가공식품 15품목 258건을 수거하여 방사능 오염을 분석하였다. 방사능 분석은 게르마늄 감마핵종 분석기를 이용하였으며, 인공 방사성 물질인 요오드(¹³¹I)와 세슘(¹³⁴Cs, ¹³⁷Cs)을 분석하였다. 모든 제품에서 ¹³¹I와 ¹³⁴Cs은 MDA (Minimum Detectable Activity)값 이상으로 검출되지 않았고, 39건에서 0.69-808.90 Bq/kg 범위로 ¹³⁷Cs이 검출되었다. 국내산 제품 6건은 0.70-3.29 Bq/kg 범위에서 검출되었지만, 원재료는 모두 수입산이었다. 수입산 제품 33건은 0.69-808.90 Bq/kg 방사능 농도를 나타내었으며, 폴란드산 블루베리 분말 제품 1건(808.90 Bq/kg) 및 링곤베리 분말 제품 2건(103.93, 188.46 Bq/kg)은 국내 방사성 세슘의 허용 기준을 초과하였다. 이러한 결과는 식품 안전 확보를 위해 수입산 장과류와 장과류 가공식품에 대한 방사능 검사 강화와 함께 수입 과정에서 더 철저한 관리가 필요한 것으로 판단된다.

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.342-346
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• 1999

This study was performed to investigate the effect of cyclosporine (CsA) on glucose tolerance and peripheral insulin sensitivity in normal Sprague-Dawley rats. After daily treament of CsA (10 mg/kg, i.p.) for two weeks, glucose tolerance tests were carried out by the treatment of glucose (Glu, 2 g/kg, i.p.) alone or in conjunction with exogenous insulin (Ins; human regular insulin, 5 U/kg, s.c.) and measured the decrement of area under the time-plasma glucose concentration curve ($AUC_{o\longrightarrow120}$; g.min/ml) by the trapezoidal rule. The rats were divided into three groups (Glu- (Control), Ins+Glu- and CsA+Ins+Glu-, n=7 in each group). The $AUC_{o\longrightarrow120}$ of the CsA+Ins+Glu-group was significantly (p<0.01) lower than that of Glu-group (61.0% of control) and significantly (p<0.05) higher than that of Ins+Glu-group (197.4% of Ins+Glu-). The CsA+Ins+Glu- grou showed higher levels of maximal blood glucose concentration and higher $AUC_{o\longrightarrow120}$ than those of Ins+Glu-group in normal rats. Besides direct pancreatic toxicity of CsA previously reported (Hahn et al., 1972), these results suggest that CsA also make the possibility to induce peripheral insulin insensitivity and glucose intolerance in normal rats.

• 대한화학회지
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• 제28권6호
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• pp.349-354
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• 1984

요오드화알칼리금속(NaI, KI, RbI, CsI)의 상대점도와 삼투 계수를 메탄올, 에탄올, dimethylsulfoxide (DMSO), and sulfolane (TMS) 용액에서 각각 측정하였다. 각 용매에서 요오드화 알칼리금속의 점도 A계수는 MeOH > EtOH > TMS > DMSO의 순위이고, 점도 B계수는 TMS > EtOH > DMSO > MeOH의 순위이다. 또 양성자성용매인 MeOH과 EtOH에서는 dB/dT의 순위가 NaI > KI > RbI > CsI이나, 비양성자성용매인 DMSO와 TMS에서는 반대순위이다. 한편 모든 용액에서 전해질의 삼투 계수는 Raoult 법칙의 양의 벗어남으로 인해 농도증가에 따라 삼투계수는 감소하였다. 각용매에서의 전해질의 삼투계수가 커지는 순위는 EtOH > DMSO > MeOH > TMS이다. 이러한 사실로 부터 요오드화알칼리금속은 양성자성용매와 비양성자성용매에서의 용매화현상이 매우 다르며, 이온쌍형성 및 용매의 구조파괴현상 등이 있음을 알았다.

• Journal of the Korean Data and Information Science Society
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• 제27권4호
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• pp.1067-1074
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• 2016

A start-up demonstration test is a mechanism that is usually used to determine the reliability of equipment, for example water pumps, car batteries and power generators. The simplest and oldest start-up demonstration tests are called CS (consecutive successes) which have been studied by Hahn and Gage (1983), Viveros and Balakrishnan (1993).At first Hahn and Gage (1983) discussed the start-up demonstration test. I was based on i.i.d (independently and identically distributed) binary outcomes with the specified number of consecutive successful start-ups. Oh (2016) studied CSNCF (consecutive successful, but not consecutive failures). In this paper, we investigated the CS and CSNCF models, also their applications to start-up demonstration tests. The numerical results showed that the expectations and variances of the total number of attempted start-ups until the acceptance of the unit are gradually increasing in all of the specified number of successes as the p (probability of a successful start-up in an single trial) decreases from 0.99 to 0.90. The difference between means of the CS mode and CSNCF model is small, but variances of the CS and CSNCF are big.

• Journal of Radiation Protection and Research
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• 제41권4호
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• pp.333-338
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• 2016

Background: In case of radiation emergencies, internal exposure monitoring for the members of public will be required to confirm internal contamination of each individual. In-vivo monitoring technique using portable gamma spectrometer can be easily applied for internal exposure monitoring in the vicinity of the on-site area. Materials and Methods: In this study, minimum detectable doses (MDDs) for $^{134}Cs$, $^{137}Cs$, and $^{131}I$ were calculated adjusting minimum detectable activities (MDAs) from 50 to 1,000 Bq to find out the optimal in-vivo counting condition. DCAL software was used to derive retention fraction of Cs and I isotopes in the whole body and thyroid, respectively. A minimum detect-able level was determined to set committed effective dose of 0.1 mSv for emergency response. Results and Discussion: We found that MDDs at each MDA increased along with the elapsed time. 1,000 Bq for $^{134}Cs$ and $^{137}Cs$, and 100 Bq for $^{131}I$ were suggested as optimal MDAs to provide in-vivo monitoring service in case of radiation emergencies. Conclusion: In-vivo monitoring program for emergency response should be designed to achieve the optimal MDA suggested from the present work. We expect that a reduction of counting time compared with routine monitoring program can achieve the high throughput system in case of radiation emergencies.

• 한국염색가공학회지
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• 제12권6호
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• pp.372-379
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• 2000

Four kinds of neutral salts with different cations, LiCl, NaCl, KCl, and CsCl, were added to the dye bath to accurately understand the effect of cations on the reactive dyeing of silk with C. I. Reactive Black 5. The cations of salts added lowered the negative surface potential of the silk, improving equilibrium adsorption and the accessibility of the dyestuff to the fiber greatly and speeding up the dyeing rate in the order of $Li^+>Na^+>K^+>Cs^+$. The activation energy$(E_a)$ for the dyeing was in the order of$Li^+>Na^+>K^+>Cs^+$ but the activation free energy$(\Delta{G}^*)$, or the real energy barrier for the reaction, was in the order of $Li^+>Na^+>K^+>Cs^+$ because the degree of the contribution of E$^{a}$ to the activation entropy$(\Delta{S}^*)$ was $Li^+>Na^+>K^+>Cs^+$. It was found from this result that LiCl had the strongest lowering effect on the negative surface potential of silk. The decrease in $\Delta{S}^*$ should be attributed to the loosely bonded activated complex of dyestufffs, cations and fiber molecules at transition state. It was clarified from the Bronsted equation that salts had the ionic strength effect and the specific salt effect on the reactive dyeing.