• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.1038-1042
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• 2008

Mono and multilayer TiO2(Fe, $PEG_{600}$) films were deposited by the dip-coating on $SiO_2$/glass substrate using sol-gel method. In an attempt to improve the antibacterial properties of doped $TiO_2$ films, the influence of the iron oxides and polyethilenglycol ($PEG_{600}$) on the morphological, optical, surface chemical composition and biological properties of nanostructured layers was studied. Complementary measurements were performed including Spectroscopic Ellipsometry (SE), Scanning Electron Microscopy (SEM) coupled with the fractal analysis, X-Ray Photoelectron Spectroscopy (XPS) and antibacterial tests. It was found that different concentrations of Fe and $PEG_{600}$ added to coating solution strongly influence the porosity and morphology at nanometric scale related to fractal behaviour and the elemental and chemical states of the surfaces as well. The thermal treatment under oxidative atmosphere leads to films densification and oxides phase stabilization. The antibacterial activity of coatings against Escherichia Coli bacteria was examined by specific antibacterial tests.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.103-110
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• 1998

Several soil improvement methods are applied to stabilize soft ground. But their improvement effects are known to be reduced in view of strength under poor conditions such as marine clay. The purpose of this paper is to investigate the strength increase effects of super injection grouting on the marine clay, A series of laboratory tests and chemical analysis tests has been peformed. Through this study, the causes of strength inferiority of treated soil was analyzed and soil improvement effects of grouted soil was presented.

• 한국지반공학회논문집
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• 제25권7호
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• pp.55-64
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• 2009

본 연구에서는 실제 현장조건을 고려하여 토목섬유의 화학저항성을 측정하기 위한 개선된 시험방법이 제안되었다. 이를 위하여 시공조건에 가장 근접한 시험법을 규격화하기 위한 인덱스 및 성능시험이 실시되었으며, Arrhenius 식에 의한 가속모델을 적용하여 실험 데이터를 해석하였다. 전반적인 실험 결과를 분석, 비교하여 현장 시공조건에 부합한 개선된 토목섬유의 화학저항성 시험방법을 확립하고 그 가능성을 제시하였다.

• 대한약침학회지
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• 제20권1호
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• pp.36-44
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• 2017

Objectives: The goal of this study was to characterize Suvarna Bhasma Parada Marit by using the Ayurvedic test parameters, physico-chemical tests, and various instrumentation techniques. Methods: Suvarna Bhasma, an Ayurvedic formulation manufactured as per Bharat Bhaishajya Ratnakar 5/8357 (BBR), has been studied using various instrumentation techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), laser particle size distribution (PSD) analysis, fourier transform infrared spectroscopy (FT-IR), and atomic absorption spectroscopy (AAS), and physico-chemical parameters, such as the loss on drying (LOD), loss on ignition (LOI), and acid insoluble Ash (AIA) were determined. In addition, Ayurvedic tests, such as Rekhapurnatva (enterable in the furrows of the fingers), Varitaratwa (floatable over water), Nirdhoomta (smokeless), Dantagre Kach-Kach (gritty particle feeling between the teeth), were performed. Results: The XRD study showed Suvarna Bhasma to be crystalline in nature and to contain more than 98% gold. The mean size of the gold crystallites was less than 10 microns, and the morphology was globular and irregular. Suvarna Bhasma contains gold as its single and major element, with EDAX and FT-IR spectra showing that it is more than 98% pure gold. The moisture content (LOD) is less than 0.5%, the LOI is less than 2%, and the AIA is not less than 95%. The Ayurvedic tests, as specified above, helped to confirm the quality of Suvarna bhasma prepared as per the text reference (BBR). Conclusion: This chemical characterization of Suvarna Bhasma performed in this study by using modern instrumentation techniques will be helpful in understanding its pharmacological actions and will help in establishing quality protocols and specifications to substantiate the safety, efficacy & quality of Suvarna Bhasma.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.137-138
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• 2002

The benefits of using DLC coatings on steel in dry sliding are well known. The present study has investigated the effects of using the same materials but in a boundary lubricated environment. Tribological tests were performed using a load-scanning device and a lubricant with an extreme-pressure (EP) additive. XPS and grazing incidence XRD are used for chemical analysis. The chemical composition of the resulting tribofilm is correlated to different friction behaviors and contact loads, and indicates that high loads are beneficial for formation of low friction tribofilm.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.104-104
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• 2003

Geosynthetic Reinforcements - membrane drawn type, warp/knitted type, junction bonded type and composite type geogrids, strip type reinforcement - were used to compare the long-term perfor-mance by total factor of safety with reduction factors during service periods. To evaluate the reduction factors, wide-width tensile property, installation damage, creep deformation, chemical and biological degradation tests were performed. Long-term design strengths of geosynthetic reinforcements were calculated by using GRI standard Test Method GG4.

• Elastomers and Composites
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• 제43권2호
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• pp.72-81
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• 2008

포장도로의 소성변형을 줄여보고자 개질아스팔트가 나타나고 있다. 본 연구에서는 타이어 고무 등을 이용하여 개질된 아스팔트의 물성을 알아 보았다. 마샬안정도와 인장강도가 각각 98% 및 43% 증가하여 타이어 고무의 개질효과를 알 수 있었다. 점도, 침입 및 열 분석에서 아스팔트의 변형저항성이 향상되었음을 알 수 있었다. IR 및 GPC 실험에서 개질제의 구조가 아스팔트의 구조와 유사할 경우 두 화합물 사이에 화학결합이 발생하여 분자들의 크기가 증가함으로써 개질효과가 커짐을 알 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.169-172
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• 1995

In optmizing cutting condition for face milling operation, tool wear is an important maching factor. For the purpose of establishing the relationship between various maching factor and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical compositition and grain size of cutting tool and cutting speed have been selected as machining factor. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting condition recommended by 'Machining Data Hardbook(MDH)' as a Knowledge base, an analysis for the validity has been provided. Based on this analysis, tool life criteria applied by MDH has been modifiied. Finaly, using MDH recommended data for neural network trainning, we can compensate the result form the trained neural network for optimizing cutting condition for some given workpice and cutting tool.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.107-112
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• 2012

All chemical processes are centered in the chemical reactor. Chemical reactions are often accompanied by mixing. Mixing can influence not just reaction rate but also product distribution if more than one product is possible. So, reactor agitator is more critical in industrial reactions. High vibration was occurred on reactor agitator which is critical equipment in HDPE plant. This paper describes analysis and diagnosis for agitator vibration throughout some tests. High vibration has been occurred by misalignment and resonance. Through the correction it could be stable.

• 한국정밀공학회지
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• 제15권6호
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• pp.79-89
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• 1998

In determining optimal cutting condition for face milling operation, tool wear is an important factor. For the purpose of establishing the relationship between various machining factors and tool wear, cutting tests have been performed. As a result, hardness and chemical composition of workpiece material, chemical composition and grain size of cutting tool and cutting speed have been selected as machining factors. In addition, relationship between feed rate and workpiece hardness has been observed. Prior to utilizing cutting conditions recommended by ‘Machining Data Handbook(MDH)’ as a knowledge base, an analysis for the validity of the MDH has been provided. Based on this analysis, tool life criteria applied by MDH has been modified. Finally, using MDH recommended data for neural network trainning, the results from the trained neural network for optimal cutting condition for some given workpiece and cutting tool can be used as reference cutting conditions.