• Transactions on Electrical and Electronic Materials
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• 제11권4호
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• pp.174-177
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• 2010

We have developed an environment-friendly etching process, an alternative to the dichromic acid etching process, as a pretreatment of acrylonitrile-butadiene-styrene (ABS) plastic for electroless plating. In order to plate ABS plastic in an electroless way, there should be fine holes on the surface of the ABS plastic to enhance mechanically the adhesion strength between the plastic surface and the plate. To make these holes, the surface was coated uniformly with dispersed chemical foaming agents in a mixture of environmentally friendly dispersant and solvent by the methods of dipping or direct application. The solvent seeps into just below the surface and distributes the chemical foaming agents uniformly beneath the surface. After drying off the surface, the surface was heated at a temperature well below the glass transition temperature of ABS plastic. By pyrolysis, the chemical foaming agents made fine holes on the surface. In order to discover optimum conditions for the formation of fine holes, the mixing ratio of the solvent, the dispersant and the chemical foaming agent were controlled. After the etching process, the surface was plated with nickel. We tested the adhesion strength between the ABS plastic and nickel plate by the cross-cutting method. The surface morphologies of the ABS plastic before and after the etching process were observed by means of a scanning electron microscope.

• 한국동물위생학회지
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• 제29권3호
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• pp.317-330
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• 2006

This study was conducted to develop the analytical method about simultaneous determination for synthetic antimicrobials in muscle by high performance liquid chromatography - mass selective detector (HPLC- MSD). Solid phase extraction (SPE), matrix solid phase dispersion (MSPD) and liquid-liquid extraction (LLE) have been adapted as pretreatment procedures for HPLC- MSD. Among various solvent tested, methanol was chosen for extraction of synthetic antimicrobials in muscles. For the optimized response, the values of various MS parameters including fragment voltage, drying gas flow, nebulizer pressure, drying gas temperature were verified. The average recovery rates using MSPD and SPE for muscles of bovine and pork were 78.9-127.1% and 78.3-121.7%, respectively. This method was verified the satisfactory performance for fourteen synthetic antimicrobials excepting carbadox in muscle of pork as detection limit of $0.05{\mu}g/g$ on API/ES SIM mode.

• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.97-112
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• 1995

The purpose of this study was to evaluate the effect of wetting condition made by drying time on bonding of resin cement to dentin. Freshly extracted bovine teeth were grinded to expose flat dentin surfaces. After the exposed dentin surfaces were treated with pretreatment agents and water rinse, each wetting condition of dentin surfaces was made according to drying times and methods including slight blow bry for I-second by air syringe, blow dry for 20-second by air syringe, and 12-hour dry in desiccator respectively. and then, previously made composite resin specimens were bonded onto each conditioned dentin surface of the specimen using Panavia-21(Kuraray Co.), Bistite(Tokuso Co.), and Choice(use with All bond-2, Bisco Inc.) resin cement according as manufacturer's instruction. Bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, then the tensile bond strength was measured, cohesive failure rate was calculated, and fractured dentin surfaces and acrylic rod sides were examined under scanning electron microscope. The result were as follows ; In the group of bonding with Panavia-21 resin cement, higher tensile bond strength was seen in 12-hour dry group than in I-second and 20-second dry group(p<0.01). In the group of bonding with Bistite resin cement, higher tensile bond strength was seen in 1-second dry group than in 20-second and 12-hour dry group(p<0.01). In the group of bonding with Choice resin cement, no significant differences of bond strength under given drying time were seen. Cohesive failure rates derived from the groups of bonding with Panavia-21 and Choice resin cement were increased with the increase of tensile bond strength in each drying time. On SEM examination of fractured surface, adhesive failure mode with fractured resin tags was mostly seen in wet condition with I-second drying time in the group of bonding with Panavia-21 resin cement, mixed failure mode with shortened and fractured resin tag was seen in the group of bonding with Bistite resin cement, and regardless of drying time, and cohesive-adhesive mixed failure mode with fracture of 'Hollow' typed resin tags was mainly seen in the group of bonding with Choice resin cement.

• 한국식품과학회지
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• 제33권4호
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• pp.395-400
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• 2001

동결건조묵을 인스탄트화 하기 위하여 당용액으로 전처리한 것과 무처리 한 것을 동결건조하여 건조물의 재수화특성과 품질특성을 비교해 보았다. 당용액(sucrose)에 침지하여 전처리한 묵의 재수화 효율은 무처리가 가장 높았고 당침지의 경우는 60%, 40%, 20% 순으로 낮아졌으며 온도의 영향은 당용액의 농도와는 관계없이 $90^{\circ}C$에서 가장 우수하였다. 수분흡수속도상수 또한 온도가 증가할수록 높은 값을 보였으며 무처리가 가장 높은 값을 나타내었다. 당용액으로 전처리한 묵의 표면색도는 전처리에 따라 큰 차이가 없었으나 조직특성은 재수화온도가 높을수록 낮은 값을 보였으며 당용액에 전처리했을 경우 60%처리구가 시판묵과 비슷한 품질 특성을 보여 품질손상을 억제하였다. 관능검사결과도 60%처리구와 무처리구가 높게 평가되었으나 재수화 효율면에서는 무처리가 우수한 것으로 나타났다.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.363-368
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• 2003

The purpose of this study is to evaluate the effect of additional enamel etching with phosphoric acid on the microleakage of the adhesion of self-etching primer system. Class V cavity($4mm{\times}3mm{\times}1.5mm$) preparations with all margins in enamel were prepared on buccal surface of 42 extracted human upper central incisor teeth. Prepared teeth were randomly divided into 3 groups. Group 1：no additional pretreatment with 37% phosphoric acid (NE). Group 2：additional pretreatment with 37% phosphoric acid for 10 seconds (E10s). Group 3：additional pretreatment with 37% phosphoric acid for 20 seconds (E20s). The adhesives(Clearfil SE $Bond^{\circledR}$, Kuraray, Osaka, Japan) and composite resins(Clearfil $AP-X^{\circledR}$, Osaka, Kuraray, Japan) were applied following the manufacturer's instructions. All the specimens were finished with the polishing disc(3M dental product, St Paul, MN, USA), thermocycled for 500 cycles between $5^{\circ}C$ and $55^{\circ}C$ and resected apical 3-mm root. 0.028 stainless steel wire was inserted apically into the pulp chamber of each tooth and sealed into position with sticky wax. Surrounding tooth surface was covered with a nail varnish 2 times except areas 1mm far from all the margins. After drying for one day, soaked the samples in the distilled water. Microleakage was assessed by electrochemical method(System 6514, $Electrometer^{\circledR}$), Keithley, USA) in the distilled water. In this study, the microleakage was the lowest in group 1 (NE) and the highest in group 3(E20s)(NE

• Journal of the Korean Wood Science and Technology
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• 제36권6호
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• pp.59-68
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• 2008

본 연구에서는 엔드테이핑(End-taping) 처리가 두께가 20~75 mm이고, 직경이 120~470 mm인 백합나무 원반들의 고주파진공건조중 건조결함 예방 미치는 영향에 대하여 조사하였다. Inside end-taping (Inside-ET)과 Outside end-taping (Outside-ET)의 경우 두께 33 mm, 직경 270 mm 이하 원반에서 할렬의 예방효과가 우수하게 나타났다. 직경이 30 cm 이하이고, 두께 60 mm와 두께 75 mm의 원반에서도 전처리을 통하여 경계할렬을 예방할 수 있을 것으로 기대되었다. 경계할렬의 발생위치는 0.50~0.63 diameter 지점으로서 직경에 따라서 상이하였으며, 따라서 횡단면의 부분 엔드테이핑 처리의 경계선도 원반의 직경 따라 적정하게 선정할 필요가 있는 것으로 조사되었다. 중경재의 경우 0.3 diameter 지점이 경계할렬 예방을 위한 전처리의 경계점일 가능성이 높을 것으로 해석된다. 대경재의 경우 경계할렬과 V형 크랙에 의한 손상이 매우 심하였으며, 이는 방사방향으로의 함수율 분포변이가 극심한 백합나무 고유의 재질특성에 기인한 것으로 해석된다. 따라서 대경재의 경우 원반으로 활용하는 것은 적절하지 않는 것으로 생각된다.

• 한국식품영양과학회지
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• 제38권7호
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• pp.879-884
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• 2009

부추 건조 분말을 제조하기 위한 최적 열풍건조온도 조건을 확립하고 건조온도 조건에 따른 부추 건조 분말의 생리활성을 가진 클로로필과 SOD 유사활성의 변화정도를 살펴본 결과는 다음과 같다. 건조온도는 부추의 수분함량의 변화에 큰 영향을 미쳤으며 건조온도가 증가함에 따라 건조시간은 현저하게 단축되었다. 부추의 전처리에서 건조시간은 건조 온도가 $70^{\circ}C$ 또는 $80^{\circ}C$에서는 건조 완결시간이 200분 이상소요되었으나 $100^{\circ}C$에서는 120분 이내에 건조가 거의 완료되었다. $100^{\circ}C$에서 30분간 건조하고 그 이후는 $70^{\circ}C$에서 건조하는 조건에서는 약 160분, $100^{\circ}C$에서 60분간 건조하고 그 이후는 $70^{\circ}C$에서 건조하는 조건에서는 건조완료 시간이 120분으로 건조조건의 변화로 건조시간을 단축시킬 수 있었다. 또한 건조온도는 부추의 색도의 결과에도 큰 영향을 미쳤으며 L값은 대조구인 동결 건조한 시료가 49.56, $100^{\circ}C$에서 30분간 건조한 다음 $70^{\circ}C$에서 건조를 완료하는 조건의 시료가 49.19, $100^{\circ}C$에서 60분에서 건조한 다음 $70^{\circ}C$에서 건조한 것으로 각각 48.55로 높았으며, 녹색도(a)는 대조구인 동결 건조한 시료가 -13.24, $100^{\circ}C$에서 30분간 건조한 다음 $70^{\circ}C$에서 건조를 완료하는 조건의 시료가 -9.15, $100^{\circ}C$에서 60분에서 건조한 다음 $70^{\circ}C$에서 건조를 완료하는 조건의 시료는 -8.86로 가장 높았으며, 황색도(b)값 역시 대조군인 동결 건조한 시료는 22.01, $100^{\circ}C$에서 30분에서 건조한 다음 $70^{\circ}C$에서 건조를 완료하는 시료는 15.71, $100^{\circ}C$에서 60분에서 건조한 다음 $70^{\circ}C$에서 건조한 시료는 15.31로 가장 높게 나타내어 부추의 건조에 적정 조건이라 생각되었다. 또한 건조 조건별 클로로필 함량 역시 $100^{\circ}C$에서 30분에서 건조한 다음 $70^{\circ}C$에서 건조를 완료하는 시료가 177 mg%로 가장 낮은 온도인 $70^{\circ}C$에서 건조시킨 부추 시료 179 mg%와 유사한 값을 나타내어 여러 건조 조건 중에서 가장 엽록소 함량이 높았다. SOD 유사활성 역시 대조구인 동결건조 부추에서 1,250(unit/g)으로 가장 높았으며 다음은 $100^{\circ}C$ 60분$-70^{\circ}C$ 건조완료한 부추가 1,176, $100^{\circ}C$ 30분$-70^{\circ}C$ 건조완료한 부추가 1,141로 고온이나 비교적 장시간 열풍에 노출되는 조건에 비해서 높은 값을 나타내었다. 이렇듯 $100^{\circ}C$에서 제한된 시간 동안 건조하고 $70^{\circ}C$에서 건조를 완료하는 것이 부추의 색도와 생리활성 물질을 최대로 유지하면서 건조시간을 단축시킬 수 있는 조건임을 확인하였으며 열풍건조 이후에도 색도와 생리활성 물질인 클로로필과 SOD 유사활성 물질의 효과가 상당량 존재하여 부추 건조 분말의 저장성 및 생리활성 효과를 기대할 수 있을 것으로 판단된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1688-1689
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• 2011

A simple and rapid capillary electrophoresis method was developed for the quantitative analysis of common triazine herbicides. Cyclic voltammetry was employed to clarify the detection voltage which showed characteristic irreversible cathodic peaks. For the analysis, the mixture of triazine herbicides was applied in a microfluidic chip to determine the CE-separated peaks. Soil sample extracts were analyzed directly after drying and redissolution with the supporting electrolyte but without other pretreatment. The results were comparable to those obtained by HPLC with UV detection. Therefore, this method can be used in the rapid determination of pesticide/herbicide residues.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.73-82
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• 2001

The ESEM could be used in investigating the fibrous networks developed during handsheet-forming processes with the exception of the stages relating to the actual dispersion of the fibers and the drying of formed sheets. Also the cross-sectional images of swollen fibers were generated with the ESEM but the information given by the images was rarely fresh compared to the CLSM images. The LTSEM was extremely useful in generating images of the microfibrillar structure of a wet fiber with great resolution. However, pretreatment required in the LTSEM chamber was somewhat tedious due to the time consumed in sublimation of ice and sputter coating. For observation of lamellar structure of a hydrated fiber, the LTSEM exhibited greatly detailed structure with high resolution. Finally ESEM and LTSEM should be used in a finite field such as observation of surface morphology in detail.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.419-423
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• 2008

This study is regarding to the Print System recording the information for the treatment on vessel steel plate in the process Ship Drying on moving without stopping. The print head accepts the locating information of moving steel plate sensored in sensor and It is aimed for the construction of facilities that the print head prints the information of maps, letters and signals for treatment on Steel plate surface on moving.