• Elastomers and Composites
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• v.7 no.2
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• pp.215-223
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• 1972

• Journal of Conservation Science
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• v.18 s.18
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• pp.75-88
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• 2006

This study tries to find out the properties of soft ind hard white wares of white wares from Dudong-ri in a scientific way, especially by meant of physical chemical analysis, microstructural observation. As a result, In the physical analysis, soft white wares are found to have higher absorption and porosity. In the composition analysis, the chemical property, of body and glaze, shows that the composition of them varies with excavation areas. However, no clear difference is identified between the soft and hard white wares which are from the ssme kiln. The microstructural observation visibly shows the difference of hard and soft white wares which it verified in the physical property Minerals with round pores and vitrified feldspar are observed in the body of hard white wares, but no vitrified particles but widely distributed pores with long and sharp irregular shapes are found in the body of soft white wares. In conclusion, the hard and soft white wares from Dudong-ri kiln are mainly influenced by physical property and microstructural rather than chemical composition and firing atmospheres. However, more and various comparative studies are needed since the resources with various physical properties vary among kilns of each production area.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.259-269
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• 2021

The effects of the physicochemical properties of soil such as soil pH, cation exchange capacity, and organic matter content on single extraction of Cd, Cr, Cu, Ni, Pb, and Zn using CaCl2, HOAc, HNO3, and DTPA were statistically investigated for 69 agricultural soils in Korea. Correlation analysis and multiple regression analysis were applied for soil samples which were grouped on the basis of average values of the physicochemical properties of the soil. Diluted HNO3 extracted higher concentrations of Cr, Cu, Ni, and Pb when compared with the other extractants, however, similar amounts of Cd and Zn were extracted by HOAc with HNO3. The results of correlation analysis indicated that DTPA extraction showed a high correlation with other single and pseudo-total extraction methods, and the physicochemical properties of soil influenced the concentrations of heavy metals leached by the single extraction methods. In the case of Zn, high correlations between pseudo-total and the studied single extraction methods were observed. As a result of regression analysis, it was found that the physicochemical properties of the soil could explain up to 74% of variances of the single extraction results. These results indicate that the physicochemical properties of the soil can have a direct influence on the concentrations of heavy metals extracted by the single extraction methods.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.731-739
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• 2021

This research aimed to analyze the characteristics of topsoil for soil conservation and promote the process of turning subsoil into topsoil. The physicochemical characteristics of topsoil and subsoil of different types of soil were compared, and their quantitative differences were examined. 204 soil samples were collected from a total of 102 areas according to rock types. These samples were tested to measure grain size, water content, and unit weight, along with XRF and XRD analyses. The topsoil and subsoil of the soil samples were also analyzed. The results of this research showed that the topsoil and subsoil had different physical characteristics, and that the chemical alteration index of the topsoil was higher than that of the subsoil. This would imply that the topsoil was high in clay minerals since it was directly affected by weathering more than the subsoil. In particular, vermiculite, one of the final products generated from weathering, was common in the topsoil.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.62-66
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• 2013

This study was performed to investigate the physicochemical characteristics of glycoprotein extracted from carrot. We manufactured glycoprotein using natural vegetable raw materials carrots, and then analyzed it's physicochemical properties. The results showed that the nutritional composition of carrot glycoprotein (CG) consisted of 2.35% carbohydrate and 94.2% glycoprotein. There were small amounts of hydroxyproline and glycine known as characteristics of collagen peptide in the amino acid of CG, but there were large amount of glutamic acid and aspartic acid involved in the metabolism of glucose and fat. The calories of CG was 342.1 kcal/100 g and the molecular weight appeared less than 594 Da average molecular weight distribution.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.141-142
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• 2022

열화란 윤활유의 물리적, 화학적 성질이 변하면서 성능이 저하되는 현상을 말합니다. 물리적 변화는 연료유, 수분, 금속 등 이물질 혼입으로 발생되며 화학적 변화는 산화 현상이 대표적이며 슬러지 등을 발생합니다. 해경 경비함정은 장시간 항해, 해상조건등에 따라 엔진의 부하변동이 많습니다. 따라서 윤활유의 역할이 매우 중요합니다. 그러나 연료혼입 등으로 윤활유가 열화되면서 수명이 단축되게 됩니다. 따라서 본 연구에서는 대표적 물리적 변화의 요인인 연료혼입를 실험적으로 고찰하고자 윤활유에 연료를 일정비율로 혼합하여 물성시험 등을 수행하였습니다. 실험결과 동점도는 윤활유에 점도가 낮은 연료유 혼입량이 증가함에 따라 점진적으로 감소하는 경향을 보였습니다.

• Fire Science and Engineering
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• v.14 no.3
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• pp.19-26
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• 2000

As a basic physical property of chemical substances, the flash point is of great importance as far as the prevention of chemical disasters is concerned. The measurement of flash point is not easy. and the number of c(Impounds for which systematic data have been collected pitifully small. Because, a need exists for some means of predicting the flash point of compound for which experimental data are unavailable, not only those which are currently in use or at the production stage, but also, those not compounds which are in the process of synthesis and design. The present research concerns the application of OCD (organic conception diagram) to the association between chemical structures and flash points, and an attempt made to discover a method of predicting the approximate flash point of a compound from its chemical structure alone.

• 전기의세계
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• v.37 no.7
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• pp.20-26
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• 1988

과학이나 공학의 발달은 측정기술과 밀접하게 연결되어 있다. 정량적으로 정밀하게 측정된 물리양은 그 물리적현상에 대한 보다 정확한 모델을 유도하고, 이로부터 보다 우수한 측정방법이 개발되고 있다. 때로는 측정기술의 발달은 새로운 이론과 개념을 요구하여 우리의 상식마저 수정하게 된다. 이 펄스를 압축하여 얻은 8femto초광펄스는 지금까지는 접근할 수 없었던 매우 짧은 시간에 일어나는 물리, 화학적인 현상을 측정하고 규명할 수 있는 장을 열었다. 또 극초단 광펄스는 공학적으로는 초고속 광통신과 광신호처리, 초고속 전자소자의 특성 측정등에도 널리 응용되고 있다. 본고에서는 여러가지 극초단 광펄스의 생성원리와 이의 응용에 관해서 검토하고자 한다.

• Journal of the KSME
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• v.28 no.1
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• pp.37-41
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• 1988

일반적으로 화학공장에서 요구되는 프로세스 펌프는 취급하는 액의 물리적 화학적 성질 및 고 형체(solid)함량, 결정생성 여부 등을 고려 이에 충분히 견디고 유지보수가 용이하며 가격 면에 서도 저렴하고 여러 가지 운전 조건에 상응할 수 있는 호환성 있는 제품이어야 한다. 다양한 액성 및 운전조건에 적합한 펌프 선정에는 실제적인 많은 시험과 경험이 필요하다. 본 글에서는 원심펌프 선정시 보편적으로 고려되어야 할 일반사항에 대하여 기술하고자 한다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.257-258
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• 2001

대기중 PM의 물리ㆍ화학적 특성은 발생 원의 종류에 따라 큰 차이가 있으며, 발생원에서 직접 배출된 1차 생성입자(Primary particles)와 가스상 물질이 물리ㆍ화학적 반응에 의하여 성장되거나 생성ㆍ변환되어 1차 생성입자와는 전혀 다른 2차 생성입자(Secondary particles)로 황산염, 질산염 및 유기물질 등이 있다. (중략)