• 한국세라믹학회지
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• 제53권1호
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• pp.116-121
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• 2016

The amount of carbon dioxide ($CO_2$) released while producing building materials is substantial and has been targeted as a leading contributor to global climate change. One of the most typical methods of reducing $CO_2$ in building materials is the addition of slag and fly ash, like pozzolan material another method is to reduce $CO_2$ production by developing carbon negative cement. MgO-based cement from the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. It is also believed that adding reactive MgO to Portland-pozzolan cements can improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, basic research on magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as the main starting materials, as well as blast furnace slag for the mineral admixture, was carried out for industrial waste material recycling. In order to increase the overall hydration activity, $MgCl_2$ was also added. In the case of the addition of $MgCl_2$as accelerating admixture, there was a promoting effect on the compressive strength. This was found to be due to the production of needle-like dense Mg-Cl hydrates. Mgnesia cement has a high viscosity due to its high specific surface area therefore, when the PC-based dispersing agent was added at a level of more than 1.0%, it had the effect of improving fluidity. In particular, the addition of $MgCl_2$ in magnesia cement using $MgCO_3$and magnesium silicate ore (serpentine) as main starting materials led to a lower expansion ratio and an increase in the freeze-thaw resistance finally, the addition of $MgCl_2$ as accelerating admixture led to good overall durability.

• 접착 및 계면
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• 제11권4호
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• pp.144-148
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• 2010

본 연구에서는 플라즈몬 공명 신호 증폭을 위한 AuNPs의 실리카 표면 개질 및 나노 입자의 안정적인 표면 박막 형성을 목표로 하였다. 직경 10 nm의 AuNPs를 수용액 상에서 제조하였으며, AuNPs 표면에 실리카 층을 단계별로 형성시켰다. Tetraethlyorthosilicate 농도를 조절함으로써 실리카 박막 두께를 조절하였으며, 얻어진 나노 입자들을 수용액 표면에 분산시켜 Langmuir-Blodgett 박막을 제조하였다. 흡광스펙트럼의 변화를 관찰함으로써 AuNPs의 크기 변화를 확인하였으며, 원자 힘 현미경으로 LB 박막의 형성 여부와 표면 균일도를 살펴보았다.

• Carbon letters
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• 제24권
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• pp.90-96
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• 2017

We demonstrated the sensitivity of optically active single-walled carbon nanotubes (SWCNTs) with a diameter below 1 nm that were homogeneously dispersed in cement composites under a mechanical load. Deoxyribonucleic acid (DNA) was selected as the dispersing agent to achieve a homogeneous dispersion of SWCNTs in an aqueous solution, and the dispersion state of the SWCNTs were characterized using various optical tools. It was found that the addition of a large amount of DNA prohibited the structural evolution of calcium hydroxide and calcium silicate hydrate. Based on the in-situ Raman and X-ray diffraction studies, it was evident that hydrophilic functional groups within the DNA strongly retarded the hydration reaction. The optimum amount of DNA with respect to the cement was found to be 0.05 wt%. The strong Raman signals coming from the SWCNTs entrapped in the cement composites enabled us to understand their dispersion state within the cement as well as their interfacial interaction. The G and G' bands of the SWCNTs sensitively varied under mechanical compression. Our results indicate that an extremely small amount of SWCNTs can be used as an optical strain sensor if they are homogeneously dispersed within cement composites.

• 대한한방소아과학회지
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• 제32권3호
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• pp.26-43
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• 2018

Objectives The purpose of this study was to analyze recent traditional Chinese medicine clinical studies for treatment of childhood obesity. Methods We analyzed 11 clinical studies from January, 2000 to March, 2018 about childhood obesity from the China Academic Journal (CAJ) and China National Knowledge Infrastructure (CNKI). All selected studies were Randomized Controlled Trials and analyzed in order of publication year, demographic information, treatment method, evaluation methods, results, adverse reactions and relapse after treatment discontinuation. Results The main Traditional Chinese Medicine (TCM) treatment was the herbal decoctions, granules and pills. In most studies, the total efficacy of the treatment group was reported to be higher than that of the control group. Adverse reactions were found in small number of studies. Frequently used medical herbs were Crataegi Fructus (山?), Atractylodis Rhizoma (蒼朮), Citri Pericarpium (陳皮), Poria (茯?), and Nelumbinis Folium (荷葉). Also, Water-draining and swelling-dispersing medicinal (利水退腫藥), Qi-regulating medicinal (理氣藥), Resolving dampness with aroma medicinal (芳香化濕藥), Blood-activating and stasis-dispelling medicinal (活血祛瘀藥), Qi-tonifying medicinal (補氣藥), and Digestant medicinal (消食藥) were commonly used. Conclusions This study showed that traditional Chinese medicine, especially herbal medicine treatment can be effective and safe option for treating childhood obesity. These research results can be utilized in other clinical studies as well as in treatment of childhood obesity. Additional well-designed randomized controlled trials and systematic reviews are need to confirm the conclusion.

• 한국경제지리학회지
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• 제17권2호
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• pp.349-365
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• 2014

충청북도는 전국 대비 면적은 약 7.5%, 인구 및 주요 경제 지표에서는 약 3.1%를 차지할 정도로 발달이 미약하다. 그러나 충청북도는 청주시와 청원군의 통합, 정부기관의 세종시로의 이전, 수도권의 제조업체 분산을 활용하여 발전시켜야 한다. 본 연구에서는 충청북도의 인구와 입지계수를 통해 지역별 산업별 변화를 살펴보았다. 충청북도의 지역별 특화 산업 분포에 영향을 미치는 요인은 청주와 경기도와의 거리이다. 도시에서는 서비스업, 청주 및 경기도와 가까운 지역에서는 제조업, 청주와 먼 지역에서는 1차와 소비자 서비스업 중심으로 특화되어 있다. 본 연구는 충청북도의 지역별 특화 산업 선정 및 지역 정책 수립의 기초로 활용될 수 있을 것이다.

• 대한기계학회논문집B
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• 제38권8호
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• pp.701-707
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• 2014

친환경 소재인 황토는 화장품, 건축물, 식 음료 저장용기 등의 제조에 이용된다. Polyethylene terephthalate(PET, 페트) 는 식 음료 저장용기로 널리 사용되고 있으나, 미세기공(~nm)이 존재하여 페트 내 외부 사이에 공기의 유동으로 음료수에 유통기한이 단축되는 문제점이 대두되고 있다. 본 연구의 목적은 황토-폴리스티렌 하이브리드 구조체를 제작하여 이를 페트에 적용시켜 유통기한의 연장을 꾀하고자 한다. 친수성 소재인 황토의 소수성 페트에 직접적용을 위해 매개체로 소수성 폴리스티렌을 이용하였다. 나노크기의 황토입자가 분산된 현탁액을 에멀젼 중합으로 나노크기의 폴리스티렌 입자 내부에 캡슐화 시켰다. 원활한 캡슐화 과정을 위해 에멀젼 중합 조건을 확립하였으며, 제작된 하이브리드 구조체의 형태 및 캡슐화 정도를 주사전자현미경, X-선 분광기, X-선 회절 분석기로 분석하였다.

• 한국환경복원기술학회지
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• 제19권4호
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• pp.81-89
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• 2016

This study aims to understand the relationship between visitors and the degradation of natural resources in Bukhansan national park. We analyzed the trend of the number of visitors, destruction of natural resources and decrease of biodiversity per year. We further compared three types of trails, heavily-used trails and rarely-used trails and a trail with limited access, regarding the degree of destruction in the National Park through a field survey. Our result showed that increasing number of visitors had direct and indirect impact on the destruction of natural resources in the National Park. The direct impact came from visitors' excessive use of trails. Naturally, increasing number of visitors caused an immoderate use of natural resources. Physical degradation such as exposure of tree root, poor drainage of trails, trail erosion was more severe than other types of trails. Decreasing biodiversity or mild disturbance around trails is the indirect impact such as broken bough, worn-bark in rarely-used trails. Destruction scale greatly increased as the number of visitors increased. Real-named reservation system helped to prevent trails from degradation. Our result calls for the need of controlling the number of visitors to Bukhansan National Park to mitigate the degradation. We recommend dispersing visitors from the heavily-used trails to other trails and implementing real-named reservation system in the rarely-used trails for the effective management of the national park.

• 한국염색가공학회지
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• 제20권2호
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• pp.53-58
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• 2008

New dyeable PP fiber and several products from it has been developed through dispersing polyester copolymer into PP resin by a Korean synthetic fiber manufacturer and its colleagues. The dyeing properties of PET/dyeable PP double knit fabric were examined with three different types of disperse dye in this study. It was found that the disperse dye, exhausted on dyeable PP at early stage of dyeing, migrated to PET at elevated dyeing temperature when two fibers were dyed in the same dye bath. The ratios of dye distribution between two substrates dyed at $120^{\circ}C$ and $130^{\circ}C$ showed no difference. S type disperse dyes showed good build-up properties and acceptable color fastness while high light fastness type exhibited the lowest amounts of exhaustion but excellent color fastness. It might be concluded that the most appropriate dye for PET/dyeable PP double knit fabric was S type, and that some color difference between PET side and dyeable PP side was unvoidable.

• 한국의사학회지
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• 제23권1호
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• pp.23-41
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• 2010

Greater yang disease(太陽病) is a syndrome induced by peripheral obstruction. One of them is "wind stroke(中風)" with the obstruction in lymphatic system. The other obstruction appearing on circulatory system is called "cold damage(傷寒)." Kyejitang(桂枝湯) is the formula prescribed for greater yang wind stroke pattern(太陽中風證) which is caused by peripheral lymphatic duct obstruction. Ramulus Cinamoni acts as a vasodilator and Radix Paeoniae relieves the abdominal tension. They make blood move to the internal organ and this can remove the retention of peripheral lymphatic system. Covering the patient with a blanket and getting him/her to have hot and thin rice gruel causes slight Diaphoresis, contributing to relieving the retention of lymphatic system. Disharmony between nutrient and defense(營衛不和) means that pressure becomes different between lymphatic system and vascular system. Kyejitang(桂枝湯) is called releasing muscles formula(解肌劑) because it can resolve such pressure difference. Diaphoresis is not a means to eliminate pathogenic qi(邪氣) from the body. That is the syndrome proving that the body fluid has moved around when disordered fluid distribution is corrected. Therefore, diaphoresis should be induced weakly all the time. If diaphoresis is induced excessively, body fluid will move more than desired and then illness cannot be cured. In Sanghanlun(傷寒論), dispersing drugs aim at addressing the retention in the exterior field, but it actually applies to the entire exterior and interior to make body fluid move. Therefore, diaphoresis does not just act on exterior field, and freeing the stool does not only apply to interior field. Distribution of body fluid changed by pathogenic qi(邪氣) influences the whole body because the human body has a closed circulatory system. Sanghanlun(傷寒論) has included treatments for pathogenic disease. However, its value should not be limited to pathogenic disease. It is because controlling blood flow by sending body fluid to the place a doctor wants is certainly worth using for treatment of non-exogenous disease or chronic illnesses.

• 폴리머
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• 제34권6호
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• pp.534-539
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• 2010

라텍스 블렌딩 기법을 이용하여 폴리스티렌(PS)/다중벽 탄소나노튜브(MWCNT) 나노복합재료를 제조하여 나노튜브 길이에 따른 나노복합재료의 유변학적 특성을 고찰하였다. 나노복합재료 제조에 사용된 단분산 PS 입자는 무유화제 유화중합으로 제조하였고, MWCNT는 불순물 제거와 분산성 향상을 위해 표면개질 과정을 거친 후 사용하였다. 최종적인 나노복합재료는 단분산 PS 입자와 개질한 MWCNT를 초음파 교반조에서 분산시킨 후 동결건조 과정을 거쳐 제조하였다. 나노복합재료의 MWCNT 함량과 나노튜브 길이에 따른 유변학적 특성은 소진폭 진동 전단유동을 부과시켜 평가하였다. 본 연구에서 고찰한 PS/MWCNT 나노복합재료는 MWCNT의 함량이 증가할수록, 나노튜브 길이가 길수록 유변물성 향상 효과가 뚜렷하였다. 이는 MWCNT 함량이 증가할수록 나노복합재료의 유변학적 특성이 액체적 특성에서 점차 고체적 특성으로 변화하기 때문이며, 나노튜브 길이가 길수록 네트워크 구조를 달성하는 임계 농도가 작아지기 때문인 것으로 판단된다.