• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
• /
• pp.486-489
• /
• 1987

For longterm conservation of the $Si_3N_4$ gate pH-ISFET, characteristics of ISFET surface treatment with HF and surface coating with paraffin wax were investigated.

• 박물관보존과학
• /
• 제13권
• /
• pp.23-31
• /
• 2012

본 연구의 대상 유물은 경희대학교박물관 소장 철제유물로 표면에 파라핀(Paraffin)이나 밀납(Bees Wax)으로 추정되는 물질로 코팅이 되어있어 표면이 불투명하며 전체적으로 부식이 심하게 발생되어 표면이 판상으로 두텁게 박락된 상태이다. 따라서 유물 표면에 코팅 처리된 물질을 안전하게 제거하기 위하여, 코팅물질을 제거하기 위한 가역성 실험을 실시하였으며, 실험결과를 토대로 유물에 적용하여 보존처리를 실시하였다. 연구방법은 첫째, 표면에 코팅 처리된 물질의 성분을 알아보기 위하여 FT-IR분석을 실시하였다. 둘째, 각종 유기용제를 사용하여 유물에 코팅된 물질을 가역시킬 수 있는 약품이 무엇인지를 실험을 통해 확인 하였다. 셋째, 가역성실험 결과를 토대로 코팅물질 제거에 가장 적합한 약품을 선정하여 실제 유물에 적용하였다. 연구결과 첫째, FT-IR 분석결과 유물에 사용된 코팅제와 파라핀(Paraffin)은 성분이 같은 것으로 확인되었다. 둘째, 유기용제 중 xylene, toluene, trichloroethylene, methyl alcohol이 파라핀을 용융시킬 수 있는 것으로 확인되었으며 이 중 toluene이 코팅제를 제거하기에 가장 적합 한 것으로 판단되었다. 셋째, 선정된 약품을 사용하여 실제유물에 적용하는데 있어서 미세한 편들을 지지하고 있는 파라핀을 모두 제거하는 것은 유물을 붕괴시킬 수 있으므로 표면을 불투명하게 덮고 있는 부분만을 면봉이나 거즈 등을 이용하는 방법으로 파라핀을 제거 한 후 보존처리를 완료 하였다.

• 한국안전학회지
• /
• 제34권4호
• /
• pp.1-5
• /
• 2019

In the field of combined cycle power generation, thermal barrier coating(TBC) protects the super-heat-resistant alloy, which forms the core component of the gas turbine, from high temperature exposure. As the turbine inlet temperature(TIT) increases, TBC is more important and durability performance is also important when considering maintenance cost and safety. Therefore, studies have been made on the fabrication method of TBC and super-heat-resistant alloy in order to improve the performance of the TBC. In recent years, due to excellent properties such as high temperature creep resistance and high temperature strength, turbine blade material have been replaced by a single crystal superalloy, however there is a lack of research on TBC applied to single crystal superalloy. In this study, to understand the isothermal degradation performance of the TBC applied to the single crystal superalloy, isothermal exposure test was conducted at various temperature to derive the delamination life. The growth curve of thermally grown oxide(TGO) layer was predicted to evaluate the isothermal degradation performance. Also, microstructural analysis was performed by scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDS) to determine the effect of mixed oxide formation on the delamination life.

• 한국안전학회지
• /
• 제19권1호
• /
• pp.12-17
• /
• 2004

By using an experimental approach recently developed to determine the torque-tension relationship for bearing frictional characteristics of several typical bolted joints were studied. The experimental approach allows the direct determination of the bearing friction between the nut and its bearing surface. Detailed friction studies were made on the influences of the size and shape of the hole, the use of a slot in a bolted joint, contact area and position, and other factors such as turning speed, coating, and the use of wax on the bearing surface. The contact area and position of the washer have a marginal effect on the bearing friction. The organic coating on the nuts reduces the bearing friction significantly. Nuts with organic coating over a washer with zinc finish provide the smallest and the most consistent bearing friction. The results from the experimental investigation will be helpful for the better design of bolted joints bearing friction. The results from the experimental investigation Will be helpful for the better design of bolted joints.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.509-509
• /
• 2011

Superhydrophobic surfaces on alloyed steels were fabricated with a non-conventional method of plasma etching and subsequent water immersion procedure. High aspect ratio nanopatterns of nanoflake or nano-needle were created on the steels with various Cr content in its composition. With CF4 plasma treatment in radio-frequence chemical vapor deposition (r.-f. CVD) method, steel surfaces were etched and fluorinated by CF4 plasma, which induced the nanopattern evolution through the water immersion process. It was found that fluorine ion played a role as a catalyst to form nanopatterns in water elucidated with XPS and TEM analysis. The hierarchical patterns in micro- and nano scale leads to superhydrophobic properties on the surfaces by deposition of a hydrophobic coating with a-C:H:Si:O film deposited with a gas precursor of hexamethlydisiloxane (HMDSO) with its lower surface energy of 24.2 mN/m, similar to that of curticular wax covering lotus surfaces. Since this method is based on plasma dry etching & coating, precise patterning of surface texturing would be potential on steel or metal surfaces. Patterned hydrophobic steel surfaces were demonstrated by mimicking the Robinia pseudoacacia or acacia leaf, on which water was collected from the humid air using a patterned hydrophobicity on the steels. It is expected that this facile, non-toxic and fast technique would accelerate the large-scale production of superhydrophobic engineering materials with industrial applications.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2067-2072
• /
• 2007

Understanding of the impinging behavior of an electrically charged spray is essential in determining appropriate operating conditions for electro-spraying of paints, surface coating materials and insecticides. In the present work, as an initial step, the wall impact of an electrically charged droplet has been experimentally investigated. The charged drops were directed on the surface of a paraffin wax, and the impinging behavior was visualized and recorded using a CCD camera to identify the impingement regime. The spread-rebound boundary for the charged drop turned out to be smaller compared to that for an electrically neutral droplet under the same surface condition. The shift of the transition criterion is considered to be due to the discrepancy between the maximum spread ratio of the electrically charged droplet and that of the neutral droplet.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
• /
• pp.803-810
• /
• 2000

Red pepper powder is produced from dried red pepper through milling process with roller mill. Traditional Roller mill is convenient for crushing wax and fiber parts in red pepper. However, some metallics are produced by the friction of two rollers when it operates without feeding of red peppers. In order to reduce this metallic problems created in the roller mill in the process of red pepper, a new roller mill mechanism which enables two roller to apart when red pepper is not fed between two rollers was introduced. Adjustment of clearance between two rollers was able to conducted by the current difference between idling and crushing process. Two types of roller surface, grove and flat, and two different roller mills, cast iron and Ti coating, are tested and compared in this experiment.

• 한국표면공학회지
• /
• 제28권1호
• /
• pp.23-33
• /
• 1995

AISI 304 stainless steel has high resistance to corrosion due to the presence of a self-healing chromium oxide film on the surface, which also accounts for the difficulty in plating. Surface cleaning of this alloy is of fundamental importance in gold plating since its effectiveness puts an upper limit on the quality of the final coating. The cleaning of AISI 304 stainless steel was investigated with elimination of artificial passive oxide film and degreasing of remaining buffing wax as stearic acid. The familiar cleaning methods i.e. ultrasonic cleaning, electro-cleaning and activation treatment were fabricated in this study. Activation treatment showed best cleaning efficiency for elimination of passive oxide film among these methods, which was also confirmed by AES (Auger electron spectrometer) analysis. However, the best condition of cleaning was obtained by combining these methods. Electrocleaning time, for degreasing the stearic acid layer, was decreased with increasing amount of added KCN.

• 농업과학연구
• /
• 제13권1호
• /
• pp.62-67
• /
• 1986

상치 종자(種字) (과실)의 과피(果皮) 및 과피맥(果皮脈)을 SEM을 이용(利用)하여 관찰(觀察)하였다. 그 결과(結果) 과피(果皮) 및 과피맥(果皮脈)의 형성(形成)뿐만이 아니라 외피각질층(外皮角質層)의 왁스(epicuticular wax)의 발달까지도 종자(種子) 형성시(形成時)의 저온조건(低溫條件)에 의하여 크게 촉진되는 반면, 고온(高溫)에 의하여 발육(發育)이 매우 부진하다는 사실을 알았다. 또한, 이러한 사실이 종자(種子)의 품질(品質) 형성(形成) 및 수명에 영향(影響)을 주는 하나의 요인(要因)이 될 수 있다고 생각되었다. 또한, TEM을 이용(利用)한 관찰(觀察)에서는 상치 종자(種子)가 흡수후(吸水後) 불과 4시간(時間)안에 배유의 활동(活動)이 시작되며 배유세포가 서로 원형질(原形質) 연락사를 통하여 연결된다는 사실을 확인(確認)하였고, 과피(果皮)에 유합된 종피(種皮)는 여러 가지 섬유질의 라멜라층을 이루고 있다는 사실을 알아내었다.

• 보존과학회지
• /
• 제34권4호
• /
• pp.259-271
• /
• 2018

Outdoor copper alloy is exposed to the atmospheric environment, accelerating corrosion progress compared with indoor copper alloy. In order to prevent corrosion, the outdoor copper alloy is coated with wax to block external corrosion factors. However, corrosion of the inside of the coating film is highly likely to continue without the internal corrosion prevention treatment. B.T.A, which is used as a copper alloy water-soluble corrosion inhibitor, has a high possibility of being harmful to the human body and is mainly used to treat excavated artifacts. This study had selected the water-soluble corrosion inhibitor, which was easier to use than the existing wax and B.T.A being used in corrosion inhibition treatment for outdoor copper alloy. A comparative study was conducted on B.T.A, which is a water-soluble corrosion inhibitor used on excavated artifacts, and $VCI^{(R)}$, $Rus^{(R)}$, and L-cys, an amino acid corrosion inhibitor, used for tin bronze test pieces. The experimental method was conducted for a certain period of time with the salt, acid, and air pollution affecting the corrosion of outdoor copper alloy. Based on experiment results, it was concluded that the best water - soluble copper alloy corrosion inhibitor in the atmospheric environment is $VCI^{(R)}$. and it could be considered to be applied in replacement of B.T.A due to its low harmfulness. In addition, $VCI^{(R)}$ is judged to serve as a corrosion inhibitor for outdoor copper alloy because it showed the best result even in the outdoor exposure test which is a real atmospheric environment.