• Title/Summary/Keyword: Standardized materials

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Development of Certified Reference Materials for Specific Surface Area (비표면적 인증표준물질 개발)

  • Choi, Byung Il;Kim, Jong Chul;Kim, Taeyoung;Nham, Hyunsoo;Kwon, Su Yong
    • Analytical Science and Technology
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    • v.18 no.1
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    • pp.74-84
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    • 2005
  • Understandings of adsorption characteristic of interface are very important in several advanced materials processes, related to NT and BT technology. Volumetric gas adsorption method, suitable for absolute measurements, is regarded as the standardized measurement technique for specific surface area. In order to verify the reliability of commercial equipments, certified reference materials (called CRM) of specific surface area are developed and evaluated its uncertainty factors by standard equipment which has traceability to SI units. Specific surface areas of developed materials are $10.72{\pm}0.46m^2g^{-1}$ for silicon nitride powders and $149.50{\pm}3.44m^2g^{-1}$ for alumina. These disseminations of CRMs would result in improved reliability chains in industrial processes, and lead eventually to contribution to productivity improvement, quality management, safety evaluation, and possibly to new material development.

Establishment and Selection of Indicator Materials for Cervi Parvum Cornu Pharmacopuncture

  • Yang, Kyu-Jin;Lee, Ki-Beom;Kim, No-Hyeon;Kim, Tae-Gyu;Gi, Yu-Mi;Joo, Hwan-Soo;Suh, Chang-Yong;Lee, In-Hee;Chung, Hwa-Jin;Ha, In-Hyuk;Lee, Jae-Woong
    • Journal of Acupuncture Research
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    • v.34 no.4
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    • pp.180-184
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    • 2017
  • Background: Recently, Cervi Parvum Cornu pharmacopuncture has been widely used. But no studies on the indicator materials for Cervi Parvum Cornu pharmacopuncture have been conducted. The aim of this study was to select indicator materials that would aid in the uniform preparation of standardized Cervi Parvum Cornu pharmacopuncture. Methods: Three lots of Cervi Parvum Cornu pharmacopuncture were analysed. Each lot was prepared using the same methods and materials. Chondroitin sulfate, alanine, and leucine were selected as the indicator materials for Cervi Parvum Cornu. For standardization, chondroitin sulfate analysis was performed using the colorimetric method, while alanine and leucine were analyzed using liquid chromatography-mass spectrometry (LC-MS). Results: Analysis of the three lots of Cervi Parvum Cornu pharmacopuncture found chondroitin sulfate levels of $108.9{\pm}17.3ug/ml$, $118.8{\pm}5.0ug/ml$ and $112.3{\pm}11.9ug/ml$. Alanine levels were $44.9{\pm}2.8ug/ml$, $44.6{\pm}0.3ug/ml$, and $43.9{\pm}0.2ug/ml$. Leucine levels were $29.6{\pm}0.7ug/ml$, $29.0{\pm}0.1ug/ml$, and $29.4{\pm}0.1ug/ml$. Conclusion: These results suggest that chondroitin sulfate, alanine, and leucine may be useful for the standardization of Cervi Parvum Cornu pharmacopuncture.

A Study of the Development of Teaching Materials for Computer Education in Teachers' College (교원양성대학의 컴퓨터교육 교재개발 연구)

  • Park, Sun-Joo;Kim, Jeong-Rang;Kim, Chul;Jeong, Dong-Ryul
    • Journal of The Korean Association of Information Education
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    • v.4 no.1
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    • pp.72-82
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    • 2000
  • The importance of computer education has increased as a knowledge-based society develops. The national project for developing the industry of educational information will be ended by the year of 2000 From year 2001 on, the korean government plans to include computer education in Elementary and Middle-School Curricula. Teachers' colleges in Korea need to develop standardized teaching materials. These teaching materials may be used to teach a computer education class, plan a computer education curriculum, and do research on computer education teaching methods as well as computer education teaching materials. This study attempted to examine some aspects for developing teaching materials which we may use to teach pre-service teacher trainees in a teachers' college. The results of this study will help pre-service teacher trainees not only improve their ability of information literacy, but also obtain some techniques and strategies for teaching computer education in school.

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An in vitro model of Fusobacterium nucleatum and Porphyromonas gingivalis in single- and dual-species biofilms

  • Tavares, Livia Jacovassi;Klein, Marlise Inez;Panariello, Beatriz Helena Dias;de Avila, Erica Dorigatti;Pavarina, Ana Claudia
    • Journal of Periodontal and Implant Science
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    • v.48 no.1
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    • pp.12-21
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    • 2018
  • Purpose: The goal of this study was to develop and validate a standardized in vitro pathogenic biofilm attached onto saliva-coated surfaces. Methods: Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) strains were grown under anaerobic conditions as single species and in dual-species cultures. Initially, the bacterial biomass was evaluated at 24 and 48 hours to determine the optimal timing for the adhesion phase onto saliva-coated polystyrene surfaces. Thereafter, biofilm development was assessed over time by crystal violet staining and scanning electron microscopy. Results: The data showed no significant difference in the overall biomass after 48 hours for P. gingivalis in single- and dual-species conditions. After adhesion, P. gingivalis in single- and dual-species biofilms accumulated a substantially higher biomass after 7 days of incubation than after 3 days, but no significant difference was found between 5 and 7 days. Although the biomass of the F. nucleatum biofilm was higher at 3 days, no difference was found at 3, 5, or 7 days of incubation. Conclusions: Polystyrene substrates from well plates work as a standard surface and provide reproducible results for in vitro biofilm models. Our biofilm model could serve as a reference point for studies investigating biofilms on different surfaces.

Starter Cultures for Kimchi Fermentation

  • Lee, Mo-Eun;Jang, Ja-Young;Lee, Jong-Hee;Park, Hae-Woong;Choi, Hak-Jong;Kim, Tae-Woon
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.559-568
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    • 2015
  • Kimchi is a traditional Korean vegetable product that is naturally fermented by various microorganisms present in the raw materials. Among these microorganisms, lactic acid bacteria dominate the fermentation process. Natural fermentation with unsterilized raw materials leads to the growth of various lactic acid bacteria, resulting in variations in the taste and quality of kimchi, which may make it difficult to produce industrial-scale kimchi with consistent quality. The use of starter cultures has been considered as an alternative for the industrial production of standardized kimchi, and recent trends suggest that the demand for starter cultures is on the rise. However, several factors should be carefully considered for the successful application of starter cultures for kimchi fermentation. In this review, we summarize recent studies on kimchi starter cultures, describe practical problems in the application of industrial-scale kimchi production, and discuss the directions for further studies.

A Structural Analysis by Finite Element Method under the Dropping Condition of Standardized IP-2 Metal Container for Decommissioning Radwaste Transportation (해체폐기물운반을 위한 IP-2형 금속용기의 낙하시 유한요소해석)

  • Choi, Kyu-Sup;Park, Jea-Ho;Park, Ji-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.6
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    • pp.35-40
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    • 2015
  • An IP-2 type container is used for the transport of low-level radioactive materials. An IP-2 type metal container was modeled and analyzed for the dropping conditions in normal transport conditions required by NSSC Notice 2014-50, "Regulations on the packaging and transport of radioactive materials." Structural analyses were performed by finite element method, and the acceptability was reviewed by comparing the results with technical standards and maximum allowable stresses of each material. Structural members of the container were modeled as 3D solid elements, and the possible dropping directions were considered in these analyses. Results show that maximum stresses, maximum deformed gaps in the cover, and maximum estimated thickness reduction in structural members were well below the allowable limits; thus, the structural integrity of the container was confirmed.

European Community Legislation on Overall Migration of Plastic Food Packaging (합성수지제 식품 포장에 대한 유럽연합의 총이행량 규정)

  • Sung, Jun-Hyun;Lee, Young-Ja
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.12 no.1
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    • pp.7-12
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    • 2006
  • The EU regulation of overall migration which is the cornerstone of the limitation to ensure that plastic materials and articles intended to contact with foodstuffs are fit for the intended application, was reviewed. In Council Directives, it was established in detail what simulants, contact times and temperatures are to be used in migration tests performed under standardized conditions. In some cases, conventional conditions for substitution test was provided, because of technical reasons. Moreover, a reduction factor ranging from 2$\sim$5 may be applied depending on the foods, because olive oil which is simulant for fatty foods, is severe solvent compared with most fatty food.

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A Study on Remodeling Period by Cost Analysis of Finished and Equipped Materials in Apartment Building (공동주택 내/외장재 및 설비재의 비용분석을 통한 리모델링시기 검토를 위한 연구)

  • Oh Jin-Soo;Kim Ki-Hyung;Lee Myung-Sik
    • Korean Institute of Interior Design Journal
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    • v.14 no.5 s.52
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    • pp.218-225
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    • 2005
  • In this apartment market, many apartments are being reconstructed within even less than 20 years from their first construction. This entails many problems in environmental and economical facets, for which many researches are under way in several institutions and universities. International cases show that the international trend goes for remodeling of maintenance, management, and repairing rather than new building. The purpose of this study is to investigate the factors of cost evaluation for establishing the time period of apartment based on durability of material and equipment while considering the economic feasibility of apartment, when remodeling as a concept of sustainability regarding building is being vitalized. This study investigates the proper period of remodeling in consideration of weight accruing to the LC(Life Cycle) and cost based on the standardized durability. The weight of cost, period establishment analysis, and LC according durability varies the data values of remodeling periods. The physical durability and cost from this data enable the investigation into not only the repair period of individual materials of the apartment but also remodeling period.

Criteria of Impact Resistance of Lightweight Wall by the Large Soft Body (건식 경량벽체의 연질 충격체에 의한 내충격성 판정기준에 관한 연구)

  • Kim, Ki Jun;Song, Jung Hyeon;Choi, Soo Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.102-103
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    • 2014
  • Due to the nature of the existing load, the criteria of assessing the intensity of the lightweight wall's impact resistance has been though of as obscure. The current study, therefore, focuses on the standardized assessment of the impact resistance to the force of the large soft body applying to the lightweight wall. The gypsum board wall showed a low level of the maximum residual displacement. It is, however, required to be careful about the selection of the finishing process since the high level of the maximum displacement is likely to cause harm to finishing materials. Unlike the gypsum board, the ALC block wall displayed a considerable rigidity while showing almost no maximum residual displacement. Even with the low level of the maximum displacement due to the stiffness, the ALC block wall is still likely to be affected by the vibration derived from any impact on the surface, which demands a need for additional study. The future experimental study, accordingly, will focus on the impact of the vibration on finishing materials, consequently leading to the accurate prediction of the possibility of potential damage to the lightweight wall caused by the large soft body.

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IOT-based SMEs producing standardized information system model analysis and design (IOT기반 중소기업 생산정보화시스템 표준화 모델 분석 및 설계)

  • Yoon, Kyungbae;Chang, Younghyun
    • The Journal of the Convergence on Culture Technology
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    • v.2 no.1
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    • pp.87-91
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    • 2016
  • This study is to develop a standard model in order to establish IOT production information system and to analyze the effect. Professional IT industry and SMEs that want to build a production information system can be applied to standard models to build the system more effectively. It provides ease of construction and reliability for IOT production information system with removing irrational elements, product quality and reducing production cost. In addition, it can be applied to standardize management of raw materials supply and demand aggregation processes of production and constructed a system more effectively using standard module.