In order to respond to environmental pollution, developed countries, including Korea, have begun to conduct research to utilize hydrogen energy. For mass transfer of hydrogen energy, storage as liquid hydrogen is advantageous, and in this case, the volume can be reduced to 1/800. As such, the transportation technology of liquefied hydrogen for ships is expected to be needed in the near future, but there is no commercialized method yet. This study is a study on the technology to test the performance of the components constituting the membrane type storage container in a cryogenic environment as a preparation for the above. It is a study to find a way to respond by analyzing in advance the problems that may occur during the shear test of adhesives. Through this study, the limitations of ISO4587 were analyzed, and in order to cope with this, the specimen was supplemented so that fracture occurred in the adhesive, not the adhesive gripper, by using stainless steel, a low-temperature steel, to reinforce the thickness. Based on this, shear evaluation was performed under conditions lowered to minus 243℃, and it was confirmed that the breaking strength was higher at cryogenic temperatures.

When self-disposing of radioactive waste, it is important to follow the acceptable concentration standards for each nuclide set by the Nuclear Safety and Security Commission (NSSC). Gamma-emitting nuclides can be easily analyzed with a simple pretreatment process, but beta-emitting nuclides require a chemical separation procedure to be analyzed for radiochemistry analysis. When analyzing betaemitting nuclides for the purpose of self-disposal, there may be difficulties in radiation detection after the chemical separation process. This is because the concentration of beta nuclides in the sample may be low and some of them may be lost during the chemical separation. Therefore, measurement method of gross-beta activity can be used instead of that of each nuclide to access the compliance of selfdisposal criteria. While a proportional counter is commonly used to measure gross-beta activity, liquid scintillation counting can also be used to measure gross-beta, and we plan to compare the results of both methods.

A large amount of small and medium-sized metal waste is generated during the decommissioning of nuclear power plants (NPPs). Metal waste is mostly contaminated with low-level radioactive, so it needs decontamination for self-disposal and recycling. A large amount of Organic Decontamination Liquid Waste during decontamination will be generated. The generated organic liquid waste is low in concentration, so the decomposition efficiency is low in the decomposition process. A conditioning process is necessary to concentrate at a high concentration. For effective treatment for Organic Decontamination Liquid Waste, the composition of organic liquid waste and conditioning process were analyzed. Organic acids, metal ions, radioactive nuclides, surfactants, etc. are present in the Organic Decontamination Liquid Waste, and suspended solids are sometimes generated by various reactions. According to previous studies, the concentration of organic acids including surfactants obtained results from several tens of ppm to a maximum of 1,000 ppm, so the maximum value of 1,000 ppm was assumed. For the composition and total amount of metal ions, the average value (52.7wt% Fe, 16.3wt% Ni, 15.1wt% Cr, 15.9wt% Mn) of the distribution of metal species removed by the actual decontamination process is applied, and the total amount is 1,000 ppm was assumed. As for the radionuclides, only 60Co and 137Cs, which are expected to be mainly present, were considered, and 60Co was assumed to be 2,000 Bq/g and 137Cs to be 360 Bq/g by referring to the literature. The amounts of suspended solids were assumed to be 500 ppm by referring to the characteristics of the liquid waste generated in the decontamination process of the NPPs. Based on the estimated value, a reaction formula was established and a simulated Organic Decontamination Liquid Waste was prepared. As a result of measurement using an analysis device, the composition of the estimated and simulated Organic Decontamination Liquid Waste had similar values. The conditioning and treatment process largely consists of pretreatment, conditioning, decomposition processes. Organic Decontamination Liquid Waste goes through a pretreatment process to remove impurities with large particles. In the conditioning process, treated water that has passed through the UF/RO membrane system is discharged into the environment. At this time, Concentrated water goes through a decomposition process for processing the Organic Decontamination Liquid Waste, and is discharged to the environment through a secondary RO membrane system. The conditioning process is the low-concentration Organic Decontamination Liquid Waste in the UF membrane system is forming a micelles in an RO membrane system, concentrating it to a high concentration and then go through a recirculation process in the UF membrane system. An experiment was conducted to confirm whether the concentration of surfactants occurred during the conditioning process. As a result of the experiment confirmed that the highly concentrated surfactant formed micelles and was filtered out in the UF membrane system.

The objective of this study was to develop a simultaneous method for 8 amino acids including alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan in veterinary products using LC-MS/MS. To optimize MS analytical condition of 8 amino acids, each parameter was established by multiple reaction monitoring in positive mode. The chromatogram separation was achieved on a C18 column with mobile phase of 0.1% formic acid in D.W. and 0.1% formic acid in acetonitrile for green technology at a flow rate of 0.4mL/min for 5 min with gradient elution. The developed method was validated for mass accuracy, precision, linearity in veterinary products. Calibration curves were linear over the calibration ranges (0.5 – 10 mg/L) for all the analytes r2>0.99. Average recoveries were 92.96 – 105.61% and relative standard deviations (RSD) were 0.27 – 3.5%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 – 0.83 mg/L and 0.12 – 2.52 mg/L, respectively. All values were corresponded with the criteria ranges requested by CD 2002/657/EC. The application of this method will be helpful in quality control analysis of amino acids in veterinary products.

현재 양송이 종균은 1980년대 개발된 방법으로 제조되고 있어, 양송이 종균 품질 향상을 위한 새로운 제조 방법을 개발하였다. 그 결과 균사체량이 5.92±0.52 g/L로 가장 많이 배양된 CDB(compost dextrose broth) 배지에서 24oC에서 120 rpm으로 진탕 배양(24시간/일) 하는 통기 식(2.5 L/min) 액체배양법으로 배양기간 10일이 액체 접종원 사용으로 양호했으며, 양송이 밀 배지 종균 생산은 밀 배지 50 g당 액체 접종원 1 ml을 적정 접종량으로 하여 10일 배양하면 종균의 뭉침과 흔드는 작업없이 적절하게 배양되었음을 보고한다.

In this study, a new method of rapid preparation of carbon nanotube (CNT) solution with highly dispersed morphology by free arc excitation is proposed, which shortens the time of the preparation of CNT solution with low concentration. The principle is that the high-energy flow density heat generated by the free arc makes the vaporizable substance coated on the surface of CNTs vaporize rapidly, and then generates the bulk increasing motion, which makes the CNTs aggregates dispersed, and finally forms the CNTs gas-phase dispersion monomer with high dispersion or the cross-linking morphology of few CNTs. In this paper, the influence of gum Arabic (GA) and deionized water (DI water) contents in CNTs mixed electrode on the dispersion of CNTs in different environments (gas phase and liquid phase) is explored. In the limited case of this work, the dispersion effect is better when the mass ratio of CNTs, GA and DI water is 1:0.04:3.96 in the liquid-phase environment. The preparation method reported in this work is expected to be a rapid way to obtain low-concentration nanodispersion.

This study investigated the residue of tulathromycin (TLM) on the lung tissue of pigs intramuscularly injected with 2.5 mg/kg body weight as a single dose. Nine healthy cross swine were intramuscularly injected with the drug. Three treated animals were arbitrarily selected to be sacrificed at 7, 10 and 14 days after treatment. TLM residue concentrations in lung tissue were determined using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The drug was extracted from lung samples using acetonitrile followed by clean-up with n-hexane. The analyte was separated on a Hypersil GOLDTM liquid chromatography column using 0.1% formic acid in deionized distilled water and acetonitrile. The correlation coefficient (R2) of the calibration curve was 0.9981, and the limits of detection and quantification were 10 and 50 μg/kg, respectively. Recoveries at three spiking levels ranged between 95.0-98.2%, and relative standard deviations were less than 3.95%. In TLM-treated group, the concentration of TLM on 7, 10 and 14 days post-treatment was 627.3, 496.9, 259.1 μg/kg, respectively. The developed method is sensitive and reliable for detection of TLM in porcine lung tissues. In addition, it can detect below the maximum residue limits in animal-derived food products destined for human consumption.

Abstract We demonstrate convenient alignment technologies using imprinting lithography with sol-gel process. The aligned nano pattern is fabricated on a silicon wafer by laser interference lithography. For conformal imprinting process, aligned nano pattern was transferred onto the polydimethylsiloxane (PDMS). Using a PDMS sheet with aligned nano pattern, aligned nano pattern was created onto the sol-gel driven hafnium zinc oxide by imprinting lithography. The process was conducted at annealing temperatures of 150 °C. The obtained pattern on the HfZnO film acted as a guide for aligning liquid crystal (LC) molecules. The geometric restriction induced by aligned pattern leads to LC alignment along to the aligned nano pattern. The combination of imprint lithography and solution-processed inorganic materials proved good alternative of LC alignment technique.

우리나라의 해외 곡류 수입량과 수입국가의 다변화를 고려 해 볼 때, 호밀, 밀, 귀리 등 맥류에서 주로 발생하는 것으로 알려져 있는 맥각알칼로이드의 노출가능성도 배제 할 수 없다. 따라서 본 연구는 곡류 및 곡류가공품 중 맥 각알칼로이드에 대한 선제적 안전관리를 위해 호밀 및 가공품 (크래커, 맥주) 으로 부터 에르고메트린을 포함한 12 종 맥각알칼로이드의 공인 시험법을 개발하고자 하였다. 아세토니트릴이 함유된 2 mM 탄산암모늄용액 추출과 Mycocep catridge를 이용한 정제·농축이 전처리 방법으로 적합함이 확인되었고, 기기분석을 통해 표준물질 첨가 검량선의 직선성이 12개 알칼로이드 모두 R2 >0.99 이상이 었으며, 정량한계는 0.01 ~ 0.05 μg/kg수준이었다. 시험법 검증을 통해 대상 품목간의 차이는 있으나, 12개 맥각 알칼로이드 모두 회수율은 72~113% 수준이었으며, 반복성은 2~10% 수준으로 적합성이 확인되었다.

Liquid crystals offer plenty of useful activities as improving the stability of emulsion, increasing moisturizing power, drug release, improving skin feeling and visual effect for cosmetics fields. In order to prepare stable semi-transparent gel emulsion, liquid crystal emulsification method was used. The emulsion stabilities of systems containing glycerin, fatty alcohols, surfactants, water and oil were investigated at various temperatures as time passed. The stabilities of all emulsions were evaluated by means of a polarizing microscope, SEM, rheometer, colorimeter and DSC. Even though the samples stored at 50℃ thermostatic chamber were occurred the reduction of hardness, turbidity and △H and the peak shift, the semi-transparent gel emulsion was very stable without separation between water and oils phase in emulsion

본 연구는 국내 생산 및 수입 양식 수산물에 대해 잔류 할 수 있는 향정신성 의약품인 디아제팜 대한 안전관리 강화기반을 위해 마련되었다. 중국인민공화국 국가 표준 시험법(GB 29697-2013)을 기반으로 전처리 방법을 개선 하여 GC-MS/MS 시험법을 확립하였으며, LC-MS/MS 방 법과의 기기간 검증을 통해 확립된 시험법의 선택성, 정량한계 및 회수율에 대한 검증을 통해 디아제팜 시험법으로서의 유효성을 확인하였다. LC-MS/MS의 경우 아세토니트릴로 추출 후 PSA를 이용해 정제하였고, GC-MS/MS의 경우 아세토니트릴로 추 출후 C18카트리지를 이용해 정제하였다. 디아제팜은 표준용액을 정량한계를 포함한 농도에 따라 검량선을 작성한 결과 두 기기 모두 r2> 0.99 이상의 직선성을 확인하였다. 본 실험에서의 검출한계와 정량한계는 LC-MS/MS 및 GCMS/ MS 모두 0.0004 mg/kg, 0.001 mg/kg 수준이었으며, 평균 회수율은 각각 99.8~106%, 109~124%이었다. 또한, 분석오차는 모두 15% 이하로 정확성 및 재현성이 우수하였 으며, CODEX 가이드라인 규정에 만족하는 수준이었다. 따라서 개발된 시험법은 안전한 수산물의 국내 유통과 잔 류실태조사를 위해 활용될 것으로 기대한다.

본 연구는 소의 가식부위(근육, 신장, 간장, 지방) 중에 서 세팔렉신을 효과적으로 정량분석하기 위한 LC-MS/MS 법을 확립하고 이를 검증하기 위해 수행되었다. 확립된 LC-MS/MS에 대해 특이성, 검출한계, 정량한계, 정확도 및 정밀도에 대한 검증을 통하여 유효성을 확인하였다. 표준 용액을 이용하여 검량성을 작성한 결과, r2 > 0.999 이상의 직선성을 나타내었으며, 세팔렉신에 대한 검출한계와 정량한계는 각각 2~10과 6~30 μg/kg으로 나타났다. 또한, 회 수율은 83.9~106.8%로 나타났으며, 상대표준편차는 2.3~ 14.8%로 나타나 정확성이 우수하였다. 이는 식품의약품안 전처의 잔류동물용의약품 분석법에서 제시한 기준에 모두 적합한 수준이었다. 따라서 본 연구를 통해 개발된 LCMS/ MS법은 향후 소의 가식부위 중 세팔렉신을 분석하는데 효과적으로 활용될 수 있을 것으로 사료된다.

The stability of liquid ferrate(Ⅵ) produced by an innovative method was confirmed and the degradation characteristics of cyclic compounds(Benzene, Aniline, Toluene, 1,4-Dioxane) by liquid ferrate(Ⅵ) were investigated under the same reaction conditions. When it was compared with the ferrate manufactured by the wet oxidation method, the liquid ferrate was more stable. And the stability of liquid ferrate was tested at the storage temperature. As a result, only 17.7% of liquid ferrate(Ⅵ) has decomposed at the storage temperature(4˚C) for 28 days. Among the cyclic compounds, the aniline was rapidly degraded compare to other cyclic compounds, which seems to be due to the electron-donating ability of the substituent, -NH2 group. Especially, when 1,4-dioxane was compared with benzene, the decomposition rate of 1,4-dioxane was lower than that of benzene, suggesting that oxygen atoms hinder the electrophilic reaction. Among 4 cyclic compounds, it was observed that aniline has the highest rate constant than those of other cyclic compounds.

Large-size graphene samples are successfully prepared by combining ultrosonic assisted liquid phase exfoliation process with oxidation-deoxidation method. Different from previous works, we used an ultrasound-treated expanded graphite as the raw material and prepared the graphene via a facile oxidation-reduction reaction. Results of X-ray diffraction and Raman spectroscopy confirm the crystal structure of the as-prepared graphene. Scanning electron microscopy images show that this kind of graphene has a large size (with a diameter over 100 μm), larger than the graphene from graphite powder and flake graphite prepared through single oxidation-deoxidation method. Transmission electron microscopy results also reveal the thin layers of the prepared graphene (number of layers ≤3). Furthermore, the importance of preprocessing the raw materials is also proven. Therefore, this method is an attractive way for preparing graphene with large size.

본 연구는 우유 중에서 덱사메타손을 효과적으로 정량 분석하기 위한 LC-MS/MS법을 확립하고 이를 검증하기 위해 수행되었다. 확립된 LC-MS/MS에 대해 특이성, 검출 한계, 정량한계, 정확도 및 정밀도에 대한 검증을 통하여 유효성을 확인하였다. 표준용액을 이용하여 검량성을 작성한 결과, r2 > 0.999 이상의 직선성을 확인하였고, 덱사 메타손에 대한 검출한계와 정량한계는 각각 0.15와 0.5 ng/ mL이었다. 또한, 회수율은 98.9-109.6%로 나타났으며, 상대표준편차는 1.7-4.4%로 나타나 정확성이 우수하였으며, 이는 식품의약품안전처의 잔류동물용의약품 분석법에서 제시한 기준에 모두 적합한 수준이었다. 따라서 본 연구를 통해 개발된 LC-MS/MS법은 향후 우유 중 덱사메타손을 분석하는데 효과적으로 활용될 수 있을 것으로 사료된다.