• Nuclear Engineering and Technology
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• 제8권1호
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• pp.1-8
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• 1976

의료용 $^{18}$ F을 단시간내에 생산하기 위하여 반조분리(recoil separation), 알루미나 칼럼크로마토그래피, 증류등 지금까지 알려진 분리방법들을 검토하고 각각의 분리방법으로 얻은 생성물중의 잔사, ${\gamma}$ 방출불순물, 및 $^3$H 함량등을 결정하였다. 핵반조분리 생성물이나 알루미나 칼럼크로마토그래피에 의한 분리생성물은 순도면에서 증류 분리 생성물보다 좋지 못하였고 특히 천연탄산리티움을 표적으로 사용하는 경우는 증류법이 가장 효과적임을 알수 있었다. 천연 탄산리티움 7g을 중성자속밀도 1$\times$$10^{13}$n/$\textrm{cm}^2$/sec에서 3시간 중성자 조사하고 증류에 의해 $^{18}$ F를 정제함으로서 무담체 $^{18}$ 를 대략 2mCi 이상 (10mCi 이하)의 규모로 일상생산할 수 있으며 이때 정제에 소요되는 시간은 35~40분이다.

• 분석과학
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• 제36권6호
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• pp.300-314
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• 2023

유통되고 있는 치약제 31품목(어린이치약 6품목 포함) 및 구중청량제 18품목(어린이구중청량제 2품목 포함)의 불소 함량, pH, 보존제와 타르색소의 함량을 분석하여 제품의 품질 실태를 조사하고 기준 및 제품의 표시 사항 일치 여부를 확인함으로써 소비자에게 올바른 정보를 제공하고자 하였다. 불소 함량을 측정한 결과 치약은 26건에서 48~1472 ppm, 구중청량제는 15건에서 85~225 ppm의 불소를 함유하고 있었고 치약제와 구중청량제의 불소 검출률은 각각 83.9 %, 83.3 %로 비슷한 수준을 나타냈다. 불소가 검출된 치약제와 구중청량제 41건 중 40건은 표시량의 90.7~109.8 %로 불소 함량 기준인 90.0~110.0 %에 적합하였으나, 치약 1건이 제품에 표시된 불소함량의 36.3 %로 부적합을 나타내었다. 치약의 pH는 5.1~9.4, 구중청량제의 pH는 4.2~6.2로 기준에 모두 적합하였다. 6종의 보존제 함량을 동시 분석한 결과 안식향산은 치약 6건과 구중청량제 9건 총 15건에서 30.6 %의 검출률로 가장 많이 검출되었고, 소르빈산은 구중 청량제 9건(검출률 18.4 %)에서 검출되었으며, 파라옥시벤조산메틸, 파라옥시벤조산에틸, 파라옥시벤조산프로필, 파라옥시벤조산부틸 등 4종은 모두 검출되지 않았다. 황색4호 등 10종의 타르색소 함량을 분석한 결과 치약 2건, 구중청량제 7건 총 9건에서 적색40호, 황색4호, 황색5호, 황색203호, 녹색3호, 청색1호 등 6가지 종류가 검출되었으며, 청색 1호가 가장 많이 검출되었다. 치약제와 구중청량제에서 검출된 불소 농도, 첨가된 보존제와 타르색소는 제품의 표시사항과 일치하였고 표시면에 잘 기재되어 있었다. 검출된 보존제와 타르색소는 일일섭취량허용량과 비교하여 위해도가 낮아 안전한 수준이었다.

• 반도체디스플레이기술학회지
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• 제21권1호
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• pp.119-126
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• 2022

MAS-based glass, which has been studied to replace the ceramic material used in the plasma etching chamber, has problems such as forming and processing due to its high melting temperature. To solve this problem, in this study, fluoride was added to the existing MAS-based glass to increase the workability in the glass manufacturing and to improve the chemical resistance to CF₄/Ar/O₂ plasma gas. Through RAMAN analysis, the structural change of the glass according to the addition of fluoride was observed. In addition, it was confirmed that high-temperature viscosity and thermal properties decreased as the fluoride content increased and plasma resistance was maintained, it showed an excellent etching rate of up to 11 times compared to quartz glass.

• 한국초전도ㆍ저온공학회논문지
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• 제8권1호
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• pp.5-8
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• 2006

The growth properties of MOD-YBCO films were investigated. To enhance the growth rate of YBCO layer and inhibit the build-up of HF gas during the annealing process in TFA-MOD for YBCO coated conductors the method of low pressure annealing was employed. Total pressure was changed from 700Torr to 1Torr and its effect on growth of YBCO films was compared with atmospheric one. The lower Pressure was effective to control of the pore size in MOD method . Surface morphology of YBCO films processed at low total pres sure was rough and composed of random YBCO (103) grains. But large pores, usually observed at atmospheric process in MOD disappeared and also the number of pores was reduced at low pressure annealing. Also discussed ate the effects of Fluorine-free Y and Cu precursor solution on the development of microstructure. Dense surface me phology and with less and small pores can be provided through controlling Fluorine content.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.979-985
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• 2001

Two experiments on commercial broiler chickens (3-37 d) and WL layers (252-364 d) were conducted to study the relative bioavailability of phosphorus (P) from different P supplements in comparison to tricalcium phosphate (TCP), at constant dietary calcium (Ca):P ratio. The P sources tested were dicalcium phosphate (DCP), steam sterilized bone meal (SSBM), commercial mineral mixture (CMM), phosphoric acid (PA) and a combination of CMM + PA. Fluorine (F) content in CMM and SSBM was 13.12 and 0.14 g/kg, respectively. In commercial broiler diets, DCP, SSBM or PA could be used as supplemental P sources without affecting (p<0.05) weight gain, feed intake, tibia ash and, P and Ca contents in tibia ash when compared to TCP. Severity of leg abnormality and deposition of F in bone were higher (p<0.05) in group fed CMM. P retention and serum inorganic P content was significantly reduced (p<0.05) in CMM fed birds compared to those fed TCP, SSBM, PA or CMM+PA. Among other P sources (TCP, SSBM, PA and CMM+PA) the serum inorganic P levels did not vary significantly (p<0.05). The P retention also significantly reduced in CMM fed groups compared to those fed DCP or PA. The P retention significantly increased from 0.183 to 0.216 units by supplementation of PA to CMM diet. In layers, egg production was not affected by replacing TCP with DCP, SSBM, PA or CMM+PA, but significantly (p<0.05) reduced with CMM. Feed (kg)/kg egg mass, egg weight, shell quality (shell weight and shell thickness) and serum Ca levels were not influenced by dietary variation in P source. The poor performance of both broilers and layers fed on CMM based diets could be attributed to the presence of hlgher levels of F (647.8 and 630.1 mg/kg, respectively) and low P utilization. Based on growth, bone mineralization and P retention it is concluded that DCP, SSBM or PA can be used as alternatives to TCP in broiler diets. In WL layer diets, in addition to above P sources, CMM can also be used as supplemental P source by replacing one half of P from CMM with PA without affecting egg production and shell quality.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.162-165
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• 2005

A series of fluorine and hydroxyl containing jasmonate derivatives, which were chemically synthesized in our institute, were investigated for their effects on the biosynthesis and heterogeneity of ginsenosides in suspension cultures of Panax notoginseng cells. Com-pared to the control (without addition of elicitors), $100{\mu}M$ of each of the jasmonate was added on day 4 to the suspension cultures of P. notoginseng cells. It was observed that, jasmonates greatly enhanced the ginsenoside content and the ratio of Rb group to Rg group (i.e. $(Rb_1\;+\;Rd)/(Rg_1\;+\;Re)$ in the P. notoginseng cells. Some of the synthetic jasmonates, such as pentafluoropropyl jasmonate (PFPJA), 2-hydroxyethyl jasmonate (HEJA) and 2-hydroxye-thoxyethyl jasmonate (HEEJA), could promote the ginsenoside content to $2.55\;\pm\;0.11,\;3.65\;\pm\;0.13\;and\;2.94\;\pm\;0.06$mg/100 mg DW, respectively, compared to that of $0.64\;\pm\;0.06$mg/100 mg DW for the control and $2.17\;\pm\;0.04$ mg/100 mg DW by the commercially available methyl jasmonate (MJA); and they could change the respective Rb:Rg ratio to $1.60\;\pm\;0.04,\;1.87\;\pm\;0.01\;and\;1.56\;\pm\;0.05$, compared to that of $0.47\;\pm\;0.01$ for the control and $1.42\;\pm\;0.06$ by MJA. The results suggest that suitable esterification of MJA with fluorine or hydroxyl group could in-crease the elicitation activity to induce plant secondary metabolism. The information obtained from this study is useful for hyper-production of heterogeneous products by plant cell cultures.

• Elastomers and Composites
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• 제40권2호
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• pp.83-92
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• 2005

국제 환경규제에 적합한 자동차용 연료 호스를 개발하기 위하여, 배합조건을 달리한 FKM 고무재료를 내층재료로 하였을 경우, 기본물성을 비롯한 내열성, 내유성, 내연료성 및 투과성을 측정하고 연료 호스재료로서의 적합성을 조사하였다. 불소 함량이 증가함에 따라 불소 고무재료는 기본물성, 내열성, 내유성 및 내연료성의 증가를 보였으며, 66%, 69%, 71% FKM 혼합물에서 카본의 양을 20 phr로 하였을 때 연료 호스의 규격을 만족하는 것으로 나타났다. 이소옥탄과 톨루엔 그리고 가솔린과 메탄올을 혼합한 연료유로써 측정한 NBR 고무와 FKM 고무의 투과성에서 FKM 고무의 경우, 불소의 함량에 따라서 미세한 투과량의 차가 나타났으나 NBR 고무보다는 투과성이 매우 우수하였다. 또한 연료유의 성분비를 달리했을 때도 FKM 고무의 투과성에는 거의 영향이 없었으며, 투과성 실험을 거친 69% FKM 고무재료의 열적 특성에도 변화가 없었다.

• 공업화학
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• 제34권2호
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• pp.170-174
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• 2023

CO₂는 지구온난화의 원인 중 하나로 알려져 있으며 포집을 위하여 다양한 연구가 진행되고 있다. 본 연구에서는 표면특성 변화를 통하여 활성탄소의 CO₂ 흡착 능력을 향상시키고자 사불화탄소 플라즈마 반응을 진행하였으며, 반응 시간에 따른 흡착 특성을 고찰하였다. 플라즈마 반응 이후 활성탄소의 미세기공 부피가 모두 늘어났으며, 최대 1.03 cm³/g까지 증가하였다. 또한 반응 시간의 증가에 따라 활성탄소 표면에 존재하는 불소 함량이 0.88%까지 증가하였다. 결과적으로 본 실험을 통하여 활성탄소의 기공 특성과 표면 작용기를 동시에 조절할 수 있었다. 본 연구에서 표면처리된 활성탄소의 CO₂ 흡착량은 미처리 활성탄소에 비하여 최대 7.44%까지 향상되어, 반응 시간이 60 s일 때 3.90 mmol/g으로 가장 우수한 성능을 보였다. 이는 활성탄소 표면에 도입된 불소 작용기와 식각 효과에 의하여 증가된 미세기공 부피에 의한 시너지 효과 때문으로 판단된다. 또한, CO₂ 흡착량이 3.67 mmol/g보다 낮은 구간에서는 미세기공의 부피가 CO₂ 흡착에 더 큰 영향을 미쳤으며, 그보다 높은 구간에서는 도입된 불소의 함량이 더 큰 영향을 미치는 것을 알 수 있었다.

• 한국환경보건학회지
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• 제13권1호
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• pp.7-16
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• 1987

A study was carried out to determine the adequacy of springs as drinking water in summer and in winter separately. In this study, environmental sanitation, physio-chemical examination, bacteriologic contamination and the content of heavy metal were included. For this study, samples were collected from 8 springs which were located in the suburbs of Chunchon city. The following results were obtained. 1. There was the covering system in 1 out of 8 springs. 6 out of 8 springs showed contaminating source within lorn. 2. In physio-chemical test, six out of 8 springs were found to be unsafe for the legitimate standard of safty water. 3. Bateriologic examination clone during summer showed the evidence of coilform group at 7 out of 8 springs and during winter showed positivity at 3 out of 8 springs. 4. In the study for heavy metal content, all places showed high iron level beyond the standard level of salty water, and 4 places showed high contents of fluorine, mangan and lead.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.386-388
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• 1996

Low dielectric constant fluorinated oxide (SiOF) films were deposited using SiF$_4$/O$_2$/SiH$_4$mixtures by electron cyclotron resonance chemical vapor deposition (ECR CVD). Chemical composition of SiOF films was investigated by Fourier transform infrared spectroscopy (FT-lR). The fluorine content in the SiOF film observed by X-ray photoelectron spectroscopy (XPS). The dielectric constant decreased with increasing of the SiF$_4$ flow rate about 8sccm. The SiOF film, deposited with SiF$_4$=8 sccm, exhibited a F content of 5 atomic % and a relative dielectric constant 3.45. For evaluating SiOF films stability, humidity tests were performed.