• Nutrition Research and Practice
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• 제4권5호
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• pp.383-392
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• 2010

This study was conducted to prepare basic materials and offer advice regarding dietary habits to prevent and cure childhood obesity by comparing and analyzing dietary habit, nutritional status, blood factors, and mineral contents of hair. All subjects were stratified by their weight-length index (WLI). According to the standard WLI values, 64.9% of children were within the normal value, 13.5% of children were underweight, and 21.6% of children were overweight and obese (WLI ${\geq}$ 110%). Overall, the score assessed dietary habit for all children was $21.32{\pm}2.55$ point (921 subjects), with 5.1% of children having excellent dietary habits and 3.1% having poor dietary habits. Additionally, 37.9% of underweight children, 37.6% of normal weight children, and 43.2% of overweight and obese children consumed higher amounts of protein than underweight children did (meat, fish, eggs, and soy products) (P < 0.05). Overweight and obese children consumed more fried foods than underweight or normal weight children (P < 0.05). Moreover, 38.0% of the children had hemoglobin levels of 12 g/dl, while 7.6% were anemic (11.1 g/dl). When a hematocrit level of 33% was taken as the standard, 11.0% of children were anemic. The plasma transferrin content was $263.76{\pm}54.52$ mg/dl in overweight and obese children. The mean values of Fe, Cu, Ca, Cr, Mn, Se, Na, K, Li, V, Co, and Mo were within the reference values, but the Zn concentrations of underweight, normal weight, and overweight and obese children were $67.97{\pm}28.51$ ppm, $70.09{\pm}30.81$ ppm, and $73.99{\pm}30.36$ ppm, respectively. The Zn concentration of overweight and obese children ($73.99{\pm}30.36$ ppm) was lower than that of the standard value (180~220 ppm). Therefore, a nutritional education program and new guidance for dietary pattern should be developed to reduce the number of underweight and overweight and obese children.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.181-186
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• 2001

JLF-1 steel (Fe-9Cr-2W-V-Ta), low activation ferritic steel, is one of the promising candidate materials fer fusion reactor applications. High temperature fatigue life and tensile strength of JLF-1 steel and its TIG welded joints were investigated at the room temperature and $400^{\circ}C$. The strength of base metal (JLF-1) is in between those of weld metal and the HAZ. When the test temperature was increased from room temperature to $400^{\circ}C$, both strength and ductility decreased for base metal, weld metal and the HAZ. The longitudinal specimens of base metal showed similar strength and ductility compared with those of the transverse specimens at room temperature and $400^{\circ}C$. Little anisotropy was observed in the JLF-1 steel base metal in terms of rolling direction. Fatigue limit of weld metal which was obtained from cross-weld specimen is 495MPa. Thus, the weld metal showed the higher fatigue limit than those of base metal at both room temperature and $400^{\circ}C$. Little anisotropy of fatigue properties was observed for JLF-1 base metal in terms of rolling direction. When the test temperature was increased from room temperature to $400^{\circ}C$, the fatigue limit of both base metal and weld metal decreased substantially.

• 한국광물학회지
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• 제13권3호
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• pp.147-163
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• 2000

The mineralogy and chemical composition of reddish to brownish yellow residual soils, so called "Hwangto" have been examined according to representative host rocks. The result of the study indicates that Hwangto consists of 40-80% clay minerals and various minerals such as quartz, feldspar, hornblende, goethite, and gibbsite. Clay minerals include kaolinite, halloysite, illite, hydroxy interlayered vermiculite (HIV), mica/vermiculite interstratifield mineral and chlorite. The mineralogical constituents and contents of Hwangto were different depending on the types of host rocks. Moreover, the Jurassic granitic rocks contain relatively more kaolin minerals, whereas the Cretaceous granitic rocks contain more HIV and illite. In addition, reddish Hwangto contains relatively more kaolinite and HIV, and yellowish Hwangto contains more illite and halloysite. It is suggested that feldspars and micas of host rocks were chemically weathered into illite, halloysite, illite/vermiculite interstratified minerals, and HIV, and finally into kaolinite. Compared with their host rocks, the major chemical compositions of Hwangto tend to contain more $Al_2O_3,\;Fe_2O_3,\;H_2O$ in amount and less Ca, Mg, and Na. Hwangto contains relatively high amount of trace elements, P, S, Zr, Sr, Ba, Rb, and Ce including considerable amount of Li, V, Cr, Zn, Co, Ni, Cu, Y, Nb, La, Nd, Pb, Th in excess of 10 ppm. Relatively high amount of most trace elements were detected in the Hwangto. The major and minor chemical compositions of the Hwangto were different depending on the types of host rocks. However, their difference was in the similar range compared with the compositions of host rocks.

• 한국분말재료학회지
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• 제24권1호
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• pp.46-52
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• 2017

Fecralloy coating layer with large surface area is suitable for use as a filter media for efficient removal of hot gaseous pollutants exhausted from combustion processes. For uniform preparation of a Fecralloy coating layer with large surface area and strong adhesion to substrate, electrospray coating and thermal treatment processes are experimentally optimized in this study. A nano-colloidal solution with 0.05 wt% Fecralloy nanoparticles is successfully prepared. Optimized electrospraying conditions are experimentally discovered to prepare a uniform coating layer of Fecralloy nano-colloidal solution on a substrate. Drying the electrospray coated Fecralloy nano-colloidal solution layer at $120^{\circ}C$ and subsequent heating at $600^{\circ}C$ are the best post-treatment for enhancing the adhesion force and surface roughness of the Fecralloy coating layer on a substrate. An electrospray coating system, consisting of several multi-groove nozzles, is also experimentally confirmed as a reasonable device for uniform coating of Fecralloy nano-colloid on a large area substrate.

• 자원환경지질
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• 제12권2호
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• pp.79-93
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• 1979

한반도 내에 부존되고 있는 중적광상들은 세 주요한 Metallousenetic Epoch (Pre-Cambrian E., Jurassic-early Cretaceous E., 및 late Cretaceous-early Tertiary E.)에 생성되었고 성인으로 열수작용과 접촉교대작용에 기인된다고 보고되었다. 이중 12개 광상(달성, 산내, 일광, 상동, 대화, 월악, 복수, 옥방, 쌍전, 홍성, 삼봉, 청양)을 본 연구의 대상으로 택하고 각 지역에서 채취한 표품중 모두 25개 시료에 대하여 지화학적 실험을 수행하였다. 즉 각 분쇄된 시료 (-80+120mesh)는 super panner, 중액, isodynamic separator, UV lamp를 이용한 물리적인 처리과정을 거쳐 최종으로 입체현미경 하에서 단체분리된 후 Jarrell-Ash 1.5m Grating Spectrometer를 이용하여 본 연구대상 시료로 개발한 Spectrochemical method (Carrier: NaCl, Internal standard: $La_2O_3$)로 정량 분석되었다. 본 연구에서 밝혀낸 국내 회중석 광내에 함유되는 희유 윈소의 종류는 모두 Al, Bi, Fe, Si, Mn, Pb, Mg, Sn, Mo, Cu, Sr, Cr, Y, Ag, Ti, Ni, As, Yb의 18개 원소이며, 이들은 각각의 절대적 및 상대적인 함량과 각 광화작용의 시기, 광상의 성인, 모암, 각 원소의 mobility 그리고 회중석광의 형광색 및 육안색과 비교 검토되었다. 본 연구의 결과로 회중석광이 정출되는 과정에서 유사한 지질환경의 물리화학적인 여건이 이루어지면 그 내에 함유되는 몇 성분원소들의 화학적인 특성은 매우 유사성을 보여주는 typochemical habit를 가짐을 알 수 있었다. 본 연구에서 밝혀진 한국산 회중석 광내의 희유성분(稀有成分)으로서 Y, Mn, Sr 원소들의 Geochemical mobility의 특성(特性)은 앞으로 회중석광의 심도탐광을 위하여 고려되어야하고, 더욱 연구개발되어야 할 것이다. 또한 상기 회중석 광내의 물리적 및 화학적으로 결합되어 있는 불순물의 희유성분들은 선광 제련 파정에서 금속성분의 추출농집공정(工程)에 유용한 자료가 될 것이다.

• 한국염색가공학회지
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• 제22권3호
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• pp.194-206
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• 2010

This study was carried out to identify the optimum dyeing conditions for maximum dye uptake of Prunus yedoensis Matsumura flower extract on silk fabric and to investigate hue/tone characteristics and fastness properties of the dyed fabrics. As results, the flower extract was found to contain flavonoids by FT-IR and to show yellowish shade by UV-vis spectrum. Silk fabric was optimized for maximum dye uptake to five repetitions of dyeing at $80^{\circ}C$ for 60 min with an extract concentration of 600% owf in terms of both K/S and color differences. Pre-mordanting was more effective to dye uptake than post-mordanting for all of the mordants used. Un-mordanted and pre-mordanted fabric showed YR(Yellow Red) while most of post-mordanted ones did Y(Yellow). Main tones of dyed fabrics were sf(soft) and lt(light) in the case of unmordanting or Al-mordanting whereas they were d(dull) and g(grayish) by post-mordanting with Cu, Cr, and Fe, respectively. The fastness grades to rub and dry cleaning were reasonably good for most dyeing conditions while those to light were poor. Finally dyeing condition for each hue/tone of the dyed silk with the flower extract was optimized considering fastness properties.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E4호
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• pp.203-213
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• 2002

Receptor modeling is one of statistical methods to achieve reasonable air pollution strategies. In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The main purpose of the study was to survey seasonal trends of inorganic elements in the coarse and fine particles. Second, this study has attempted emission sources qualitatively by a receptor method, the PMF mo-del. After that. both PMF (positive matrix factorization) model and TTFA (target transformation factor analysis) model were applied to compare and to estimate mass contribution of coarse and fine particle sources at the receptor. A total of 138 sets of samples was collected from 1989 to 1996 by a low volume cascade impactor with 9 size fraction stages at Kyung Hee University in Korea. Sixteen chemical species (Si, Ca, Fe, K, Pb, Na, Zn, Mg, Ba, Ni, V, Mn, Cr, Br, Cu. Co) were characterized by XRF. The study result showed that the weighted arithmetic mean of coarse and fine particles were 51.3 and 54.4 $\mu\textrm{g}$/㎥, respectively. Contribution of both particle fractions were esti-mated using TTFA and PMF models. The number of estimated sources was seven according to TTFA model and 8 according to PMF model. Comparison of TTFA and PMF revealed that both methodologies exhibited similar trends in their contribution pattern. However, large differences between contributions were observed in some sour-ces. The results of this study may help to suggest control strategies in local countries where known source profiles do not exist.

• 한국대기환경학회지
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• 제23권6호
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• pp.718-726
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• 2007

There are many varieties of asbestos: chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophylite. These are widely used in construction materials, brake lining, textile, and so on. Even though non-asbestos fibers such as glassfiber and rockwool have manufactured because asbestos causes asbestosis, lung cancer, mesothelioma, etc., some bad effects of non-asbestos have been also reported. PCM (phase contrast microscopy) and PLM (polarized light microscopy) have been used to qualitatively analyze asbestoses. These techniques have serious drawbacks when identifying and separating various asbestoses. Recently scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX) has been known as an useful tool to analyze airborne particle since it provides physical and chemical information simultaneously. The purpose of the study was to classify both asbestos and non-asbestos fibers and finally to develop their source profiles by using the SEM/EDX. The source profiles characterized by 6 different types of asbestos fibers and 2 types of non-asbestos fibers had been developed by analyzing a total of 380 fibers. Analytical parameters used in this study were length, width, aspect ratio, and shape as physical information, and Na, Mg, Al, Si, K, Ca, Cr, Mn, Fe, and Cu as chemical information. All the parameters were intensively reviewed.

• 비파괴검사학회지
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• 제23권2호
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• pp.148-155
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• 2003

저방사화 페라이트강인 JLF는 핵융합로의 블랑켓과 같은 열교환기의 재료로써 유용한 재료이다. 이 재료의 광범위한 적용을 위해서는 JLF강과 다른 재료와의 접합기술의 개발이 중요하다. 최근 두 이종재료간의 접합에는 마찰용접이 많이 이용되고 있으며 본 연구에서도 JLF강과 STS304 간의 마찰용접에 의한 용접특성을 평가하였으며 특히 비파괴기법중의 하나인 음향방출 기법을 이용하여 두 이종재료간의 용접특성 및 최적의 용접조건을 평가하였다. 음향방출 파라미터중의 하나인 카운트와 사상수 등이 최적용접조건 및 용접품질을 평가하는데 유효한 파라미터들이었다.

• 한국물환경학회지
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• 제31권3호
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• pp.304-312
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• 2015

In this study, we tried to determine the vertical variation of sediment structure and geochemical characteristics, core sediment was collected in the Nakdong River midstream on August, 2014. Core sediment mainly composed of sand (51.48%) and silt (46.21%) and coarsing upward changed from sM to mS facies. IL and TOC were decreased from lower to upper layer. C/N ratio was lower than 10 so the organic matters were originated from underwater creatures and C/S ratio was decreased from lower to upper layer. Heavy metal (Al, Fe, Zn, Cr, Pb, Ni, Cu, Cd) content were decreased from lower to upper layer and seriously polluted condition is not. These results are thought to be due to the effect of natural and anthropogenic in the fluctuation of flow.