• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.332-332
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• 2010

We have successfully demonstrated the inkjet printing method to create $Al_2O_3$ films withouWe have successfully demonstrated the inkjet printing method to create $Al_2O_3$ films without a high temperature sintering process. In order to remove the coffee ring effect in the ink drop, we have introduced a co-solvent system in order to create Marangoni flow in the ink drop, which leads to the dense packing of ceramic powders on the substrate during inkjet process. The packing density of the Inkjet-printed $Al_2O_3$ films is around 60% (max. 70%) which is very high compared to the value obtained from the same material films by other conventional methods such as film casting, dip coating process, etc. The voids inside the films (which are around 40% of the entire film volume) are filled with the polymer resin (Cyanate ester) by the infiltration process. This resin infiltration is also implemented by the inkjet printing process right after the Ah03 film ink-jetting process. The microstructures of the printed $Al_2O_3$ films are investigated by Scanning Electron Microscope (SEM) to understand the degree of packing density in the printed films. The inkjet-printed $Al_2O_3$ films have been characterized to investigate its thickness and roughness. Quality factor of the printed $Al_2O_3$ film is also measured to be over 300 at 1MHz.

• 한국산업보건학회지
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• 제7권1호
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• pp.71-85
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• 1997

The purpose of this study was to evaluate concentrations of organic solvent mixtures in air of rotogravure printing workplaces. Qualitative and quantitative analysis of organic solvents contained in the gravure inks used at rotogravure factories had been done. The results obtained were as follows: 1. The gravure inks mainly consist of toluene, methyl ethyl ketone(MEK), and ethyl acetate(EA), and traces of isopropyl alcohol(IPA), xylene, 2-butanol, cyclohexane, cellosolve etc were also contained in them. 2. Thinner used as a diluent consist of toluene, MEK, and EA. 3. Geometric mean concentration of toluene in ambient air were 23.81 ppm at gravure printing of packing material, 42.10 ppm at gravure printing of wallpaper, 16.95 ppm at gravure printing of plastic bottle for beverage and 4.31 ppm at gravure printing of plywood printing or floor covering. Concentrations of toluene in ambient air showed statistically significant difference between types of printing. 4. Concentrations of MEK in ambient air were 12.43 ppm at gravure printing of packing material, 5.47 ppm at gravure printing of wallpaper, 16.78 ppm at gravure printing of plastic bottle for beverage and 16.44 ppm at gravure printing of plywood printing or floor covering. MEK concentrations in ambient air showed no significant difference. 5. Conentrations of EA were 14.30 ppm at gravure printing of packing material, 1.92 ppm at gravure printing of wallpaper and 21.12 ppm at gravure printing of plywood printing or floor covering. EA concentrations in ambient air shown significant difference. 6. Percentage of the workplaces where the ambient air concentration of organic solvent mixtures exceeded the Korean Permissble Exposure Level(KPEL) amounted to 18.03%. 7. Toluene concentrations in ambient air of rotogravure printing workplaces ranged from 0.69 to 156.02 ppm and urinary hippuric acid excretion ranged from 0.10 to $1.32g/{\ell}$.

• 공업화학
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• 제9권6호
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• pp.852-856
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• 1998

유동층 연소로에서 압력 요동의 통계적 처리 방법을 이용하여 충전물질의 유동층 거동에 대한 영향을 분석하였다. 실험은 내경이 6.7cm인 유동화 장치에서 수행하였고, 실험변수는 입자크기 및 분포, 유동화가스, 유동층의 aspect ratio(L/D), 충전물 등이다. 충전물질은 스크린 충전물질을 사용하였고, 압력 요동 특성은 차압 전달기로 측정하였다. 측정 압력 요동 특성치는 평균값과 표준편차, power spectral밀도 합수의 주진동수 등이다. 압력요동의 표준 편차는 압력 측정 tap의 반경 방향에 거의 영향을 받지 않았으며, 압력 측정 tap의 축방향에서는 충전물이 없는 경우 가스분산판 약 4.5cm 이상에서는 거의 일정하다. 충전물의 크기가 증가할수록 주진동수는 감소하는 경향이 나타났으며, 충전물의 양이 10% 부근에서 주진동수가 가장 큰 변화값을 나타내었다. 압력 요동의 표준 편차는 유동층 연소로의 거동을 해석하고 유동화 현상을 설명하는데 효과적이며, 압력 요동의 특성들은 충전물질에 많은 영향을 받았다.

• 분석과학
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• 제18권6호
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• pp.511-519
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• 2005

식품 포장재에 사용되는 접착제의 원료로 사용되는 우레탄의 주원료인 톨루엔 디이소시아네이트(TDI)는 인체에 노출될 경우에 독성을 일으킬 수 있다. GC/MS를 사용하여 식품 포장재에 잔류하는 TDI를 분석하기 위한 시료 전처리 조건과 분석조건을 확립하였다. 포장재 중에 포함된 TDI는 n-헵탄, 4%아세트산 등과 같은 식품유사용매를 사용하여 추출된 후, 기체 크로마토그래프/질량분석기 (GC/MS)에 의해 분석되었다. 26개의 식품 포장재를 측정한 결과 10개의 시료에서 $0.51{\sim}60.88{\mu}g/ml$ 농도 범위에서 TDI가 검출되었다. 포장재의 절단된 면에 대한 추출 용매의 접촉을 피하고 포장재 면만이 접촉하도록 한 후 추출시간을 달리하면서 실험한 결과 2시간 추출 조건에서도 0.7% 수준으로 감소되어 실제 식품 조리시에 TDI가 다량 검출될 위험은 미미한 것으로 평가되었다. 본 연구에서 확립된 톨루엔 디이소시아네이트에 대한 분석법은 외국의 유해물질에 대한 관리기준을 만족시키는 정량한계를 확보한 신뢰성 있는 방법으로 추후 관련 연구를 위한 기초 분석기술로 활용도가 높을 것으로 예상된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.81-81
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• 2009

Non-sintered Alumina films were fabricated via inkjet printing processes without a high temperature sintering process. The packing density of these inkjet-printed alumina films measured around 60%. Polymer resin was infiltrated thru these non-sintered films in order to fill out the 40% of voids constituting the rest of the inkjet-printed films. The concept of inkjet-printed Alumina-Resin hybrid materials was designed in order to be applicable to the ceramic package substrates for 3D-system module integration which may possibly substitute LTCC-based 3D module integration. So, the dielectric properties of these inkjet-printed $Al_2O_3$ hybridmaterialsareofourgreatinterest. We have measured dielectric constant and dissipation factor of the inkjet-printed $Al_2O_3$-resinhybridfilmsbyvaryingtheamountofresininfiltratedthruthe$Al_2O_3$films.

• 한국미생물·생명공학회지
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• 제30권1호
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• pp.73-78
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• 2002

4 종류의 무기담채와 지렁이 분변토를 담채로 사용하여 분변토 집식배양한 질산화 세균을 접종한 바이오필터의 암모니아 제거 특성을 규명하였다. 담채의 암모니아 흡착능은 zcocarbn(24g-NH3/kg)을 제외하고 무시할 수준이었으며, 충전부피 당 담체의 미생물 고정화량은 담채 종류와 관계없이 유사하였다. 바이오필터의 압력손실은 분변토 $\geq$ zeocarbon $\geq$ zeolite $\geq$ porous glass $\simeqporous $ 순이었다. 담체의 충전 부피를 기준으로 한 최대 제거용량($g-Nkg^{-1}$$d^{-1}$)은 zeocarbon (526) $\geq$ 분변토 (220) $\geq$ porous celite (93) > Zeolite (68) > porous glass (53) 순으로 바이오필터의 성능은 담체에 많은 영향을 받는 것을 확인할 수 있었다. 속도론적 해석에 의해 $V_{m}$과 $K_{s}$를 구하였으며, 담체들간의 암모니아 제거 성능을 고려할 때 가장 우수한 담체는 zeocarbon 이었다.

• 한국시뮬레이션학회논문지
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• 제16권4호
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• pp.67-75
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• 2007

RFID(Radio Frequency IDentification)가 국방, 물류/유통, 도서 관리 등의 분야에서 바코드를 대체하는 대안으로 각광을 받고 있으나, 적용 범위가 제품 생산이나 판매 유통 관리 등의 분야로 제한되어 있는 것이 사실이다. 본 논문에서는RFID 기술을 공정관리에 적용해 본 후, 그 효과를 분석하였다. 또한 유통단계뿐 아니라 제품의 이력관리 및 품질관리에 RFID의 적용 가능성을 타진하기 위해, 제조 및 포장공정에 활용하는 방안을 제안하였다. RFID 적용 효과를 검증하기 위해 실제 제조업체를 대상으로 현재 바코드를 부착하는 공정을 RFID로 변경하였을 때 공정 개선 효과를 산출하였으며, 연구 결과 RFID 도입에 소모되는 초기 투자 비용을 상쇄할 수 있는 비용절감 효과가 있음을 확인하였다. 이로써 높은 초기 비용으로 인해 바코드에서 RFID로의 교체를 망설이는 제조업체들의 의사결정에 기여할 수 있을 것으로 기대된다.

• 한국지역사회생활과학회지
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• 제17권3호
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• pp.43-53
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• 2006

In order to improve on the stability during the storage of Han-gwa, this study measured peroxide value, AOM test of ginseng and antioxidants added to Han-gwa. 1.2% of ginseng added to Han-gwa consists of moisture (3.37%), protein(1.30%), lipids (11.54%), carbohydrate(82.45%) and ash (1.34%). The hardness of Han-gwa was 257.7 for 1.2% of ginseng added to Han-gwa and 269.8 for Han-gwa without ginseng. The expansion coefficient of Han-gwa including 1.2% of ginseng was 12.9 magnification to Bandegi, indicating that it was inversely proportioned to the amount of ginseng. The induction period of the AOM test according to the concentration of ginseng in Han-gwa was extended to $0.53{\sim}0.83$ of magnification than the test of Han-gwa without ginseng. According to changes in AOM, acid value, peroxide value and thiobarbituric acid value of Han-gwa with various packing materials, PP multilayer film packing was the most effective material for storage of Han-gwa at 30C. 1.2% of ginseng added to Han-gwa and rosemary extract in a panel test was the most effective, and using PP multilayer film packing for Han-gwa was found to be the most useful method.

• Advances in concrete construction
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• 제10권5호
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• pp.431-441
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• 2020

For the purpose of improving the properties of UHPC as well as the economic efficiency in production of the material, Availability of river sands as fine aggregate instead of micro silica sand were investigated. Four different sizes of river sands were considered. Using river sand instead of micro silica sand increased the flowability, and decreased the yield stress and plastic viscosity in rheological properties, and the effect was higher with larger particle size of river sand. It was demonstrated by analyses based on the packing density. In the results of compressive strength and elastic modulus, even though river sand was not as good as micro silica sand, it could provide high strength of over 170 MPa and elastic modulus greater than 40 GPa. The difference in compressive strength depending on the size of river sand was explained with the concept of maximum paste thickness based on the packing density of aggregate. The flexural performance with river sand also presented relatively lower resistance than micro silica sand, and the reduction was greater with larger particle size of river sand. The flexural performance was proven to be also influenced by the difference in the fiber orientation distribution due to the size of river sand.

• 비파괴검사학회지
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• 제8권1호
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• pp.44-48
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• 1988

Quality and economy in radiography can be achieved by using the right techniques and the film material available on the market. Pre-packing with or without lead, under vacuum or not, play an important role provided the right kinds of procedures are applied. The author explains some of the ways used by different N.D.T.companies to achieve the best quality in an economical way.