• 자연과학논문집
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• 제12권1호
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• pp.81-84
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• 2002

식물 중 단자엽을 제외한 쌍자엽 식물은 선택적으로 제거할 수 있는 헤테로 고리 화합물을 기존에 알려진 방법보다 용이하게 합성할 수 있는 방법을 연구하였으며, 과정에 일부 헤테로 고리 치환기의 4위치에 염소기가 치환된 화합물 5a를 70%수율로 하는 5b는 74%수율로 각각 수득하였다. 술폰 산화제로 potassium percarbonate를 사용하였을 때 1)의 화합물을 90%수율로 고순도 화합물을 수득하였으며 2)의 경우 85%의 고수율, 고순도 화합물을 수득하였다. Sodium hypochlorite의 경우 피리미딘 헤테로 고리에 염소가 치환되는 불순물 생성으로 적합지 않음이 판명되었다.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.188-198
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• 2021

A modern approach to nuclear energy involves reprocessing like transmutations of spent nuclear fuel products to reduce their radiotoxicity and time needed for their storage. For this purpose, they are immobilized in inert matrices made of zirconia and can be "burned" in fast neutron reactor or Accelerator Driven System. These matrices in spherical form can be obtained by sol-gel process. The paper presents a method of microspheres fabrication based on the combined Complex Sol-Gel Process and double extraction process consisting in the preparation of zirconium-ascorbate sol and simultaneous extraction of water and nitrates. The procedure allows obtaining gel microspheres with a diameter of 50 ㎛, which after heat treatment are processed into the final product. The synthesis of zirconia microspheres with Yttrium by internal gelation process is well known for over a decade now. However, the explanation and characterization of synthesis of such material by extraction of water process is rarely found. Parameters such as: pH, viscosity, shape, sphericity and crystal structure have been determined for synthesized products and semi-products. In addition, preliminary research consisting in irradiation of the obtained materials in fast and thermal neutron flux was carried out. The obtained results are presented and described in this work.

• Archives of Pharmacal Research
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• 제7권2호
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• pp.145-151
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• 1984

A novel agglomeration technique, termed "Spherical Crystallization Process", which can transform directly the fine crystals produced in the crystallization or the reaction process into a spherical shape was developed. By this technique, needle like crystals such as salicylic acid were transformed into free flowing and directly compressible agglomerates. Sphericaly agglomerated aminophyline crystals were obtained directly from the reaction system, which could reduce the preparation processes, e. g. synthesis, crystallization and agglomeration, into only one step. Sodium theophyline monohydrate agglomerates were prepared by salting out, the rate process of which was described by a first order kinetics. Agglomerated crystals of ndw complex of indo-methacin-mepirizole were prepare with this technique; an improved therapeutic effect of the resultant crystals was expected. expected.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.387-390
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• 1997

Grinding process takes a long time that grinding machine is setted properly. It is difficult for user to judge correctly the abnormal states generated in grinding process. Air grinding has to be reduced for the improvement of productivity. In addition, it is important to monitor the dressing and the grinding process so that the grinding working maintains optimal grinding conditions. In this study, the monitoring system using the acoustic emission is developed to monitor these processes continuously. This system was able to reduce the preparation as well as the machine setting time in grinding operation.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.289-294
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• 2002

This paper presents first results of an interdisciplinary research project for the development of an "intelligent" welding helmet. Contrary to conventional welding helmets the system allows a detailed observation both of the welding process and the environment. By methods of virtual and augmented reality additional information can be supplied to the welder. The system can be used for welding preparation, welding process observation and quality assurance.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2001년도 가을 학술발표회 논문집
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• pp.375-378
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• 2001

At the time of facing strict environmental regulations, environmentally friendly dyeing technology is being highlighted due to the potential possibility of reducing environmental impact, so is the preparation process that uses a great deal of water and generates as much contamination. Enzyme technology has been regarded as an eco-friendly solution to industrial problems, saving water, chemicals and energy. (omitted)

• 산업경영시스템학회지
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• 제40권3호
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• pp.49-58
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• 2017

The DQMS (Defence Quality Management System) is a certification system that manages participating companies to improve the quality of munitions. Since Korean Defense Specification (KDS) for DQMS certification that was established by adding military requirements based on the ISO quality standard, many companies complain that they should pay too much effort into the preparation process. However, it is hard to find helpful information on the preparation process because we have been only interested in the effect of DQMS acquisition. The purpose of this paper is to provide helpful information to companies preparing for DQMS certification. We surveyed the degree of difficulty and importance of the DQMS requirements from the companies with certification experience, and performed IDA (Importance-Difficulty analysis) by dividing the companies into the main contractor and the subcontractor. The result of IDA shows that there is a different recognition to the DQMS certification between main-contracting and sub-contracting companies. Subcontractor has more difficulties than main contractor in preparing the DQMS certification. In addition, we are able to identify the difficult and important requirements in the preparation process to the DQMS certification. Both main contractor and subcontractor have difficulty to the requirements related to configuration or validation such as 'customer controls configuration', 'configuration review shall be implemented' and 'design and development validation documentation.' The requirements related to customers are important to main contractor but the subcontractor regards difficult requirements as important ones. The result of this paper would be helpful to both the company preparing for DQMS and the munitions quality assurance agency.

• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2542-2546
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• 2010

The objective of this paper was to investigate the effect of dextran gel on preparation of nano-liposomes loaded with ginkgolide. During preparation, Sephadex G75, G50 and G25 were added in the aqueous phase respectively. From the experiment, nano-liposomes prepared by dextran gels were found spherical and smooth. The result indicated that aperture of dextran gels were narrower, particle size of nano-liposomes was smaller (207.13 ~ 89.16 nm) and zeta potential was greater (-36.2 ~ -29.5 mV) in more negative. The study also revealed that differences of the entrapment efficiency and drug loading among the three types of nano-liposomes were not significant. In vitro drug release test demonstrated that nano-liposomes had a better controlled release. To conclude, by using dextran gel in the preparation of nano-liposome loaded with ginkgolide, the particle size could be effectively controlled and the drug stability could be improved.

• 산업식품공학
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• 제21권3호
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• pp.191-200
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• 2017

There have been great efforts to develop a rapid and sensitive detection method to monitor the presence of pathogenic bacteria in food. While a number of methods have been reported for bacterial detection with a detection limit to a single digit, most of them are suitable only for the bacteria in pure culture or buffered solution. On the other hand, foods are composed of highly complicated matrices containing carbohydrate, fat, protein, fibers, and many other components whose composition varies from one food to the other. Furthermore, many components in food interfere with the downstream detection process, which significantly affect the sensitivity and selectivity of the detection. Therefore, isolating and concentrating the target pathogenic bacteria from food matrices are of importance to enhance the detection power of the system. The present review provides an introduction to the representative sample preparation strategies to isolate target pathogenic bacteria from food sample. We further describe the nucleic acid-based detection methods, such as PCR, real-time PCR, NASBA, RCA, LCR, and LAMP. Nucleic acid-based methods are by far the most sensitive and effective for the detection of a low number of target pathogens whose performance is greatly improved by combining with the sample preparation methods.

• Journal of Information Science Theory and Practice
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• 제6권4호
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• pp.54-64
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• 2018

This study aims to understand the information needs of Korean immigrant mothers in the United States for their high school children's college preparation. A content analysis was conducted for the messages posted to a "motherhood" forum on the MissyUSA website. In total, 754 posts were analyzed in terms of a child's grade, college preparation stage, type of post, and topic of post. The study found that there is a range of information needed at different stages in a child's education. Many of the demonstrated information needs showed similarities to those of other immigrant groups, but there were also community-specific themes, such as an emphasis on STEM (science, technology, engineering, and math) and standardized tests. The forum was mainly used for factual questions, not emotional support. We concluded that the findings of the study would help researchers in understanding immigrant information needs for the college application process and how information professionals and educators could combine the needs of different ethnic groups to create customized services for them.