• 한국초전도ㆍ저온공학회논문지
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• 제11권2호
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• pp.37-40
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• 2009

A mixed working fluid has a potential to widen the operation temperature range of the thermosiphon. In this study, the thermosiphon using $N_2\;and\;CF_4$ mixture as the working fluid is fabricated and tested to verify its transient thermo hydraulic characteristic. A transparent pyrex glass tube was used for the thermosiphon itself and the vacuum chamber was also fabricated by glass to visualize the internal state of thermo siphon. Onset of condensation temperature was related to the partial pressure of $CF_4$. Two solidifications were observed and condensate temperature range of mixed working fluid was from 160K to 70.7K with $N_2$ 25% composition.

• 한국전기전자재료학회논문지
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• 제15권6호
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• pp.479-485
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• 2002

We have investigated the effects of various wafers cleaning on glass/Si bonding using 4 inch Pyrex glass wafers and 4 inch silicon wafers. The various wafer cleaning methods were examined; SPM(sulfuric-peroxide mixture, $H_2SO_4:H_2O_2$ = 4 : 1, $120^{\circ}C$), RCA(company name, $NH_4OH:H_2O_2:H_2O$ = 1 : 1 : 5, $80^{\circ}C$), and combinations of those. The best room temperature bonding result was achieved when wafers were cleaned by SPM followed by RCA cleaning. The minimum increase in surface roughness measured by AFM(atomic force microscope) confirmed such results. During successive heat treatments, the bonding strength was improved with increased annealing temperatures up to $400^{\circ}C$, but debonding was observed at $450^{\circ}C$. The difference in thermal expansion coefficients between glass and Si wafer led debonding. When annealed at fixed temperatures(300 and $400^{\circ}C$), bonding strength was enhanced until 28 hours, but then decreased for further anneal. To find the cause of decrease in bonding strength in excessively long annealing time, the ion distribution at Si surface was investigated using SIMS(secondary ion mass spectrometry). tons such as sodium, which had been existed only in glass before annealing, were found at Si surface for long annealed samples. Decrease in bonding strength can be caused by the diffused sodium ions to pass the glass/si interface. Therefore, maximum bonding strength can be achieved when the cleaning procedure and the ion concentrations at interface are optimized in glass/Si wafer direct bonding.

• 센서학회지
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• 제6권3호
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• pp.214-220
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• 1997

본 연구에서는 생화학 물질을 정량적으로 분석하기 위하여 소산장(Evanescent field) 흡수를 이용한 박막 광도파로형 칼륨이온센서를 제작하였다. 도파로는 Pyrex glass($26{\times}19{\times}1mm$, $n_{1}=1.485$ at 514nm, Ar laer ; Coherent 사 M532) 기판위에 RF sputtering법으로 Coming-7059 glass($n_{2}=1.588$, at 514nm, Ar laer ; Coherent사 M532) 2 종류의 박막 광도파로를 형성하였으며, 그 두께는 프리즘 결합법으로 측정한 결과 각각 $T_{1}=1.04{\mu}m$ 와 $T_{2}=1.41{\mu}m$ 였다. 칼륨이온 선택성의 이온감지막은 변색성 이온감응물질인 ETH 5294와 중성이온감응물질인 valinomycin을 poly(vinyl chloride-co-vinyl acetate-co-vinyl alcohol) ( 91 : 3 : 6 ) 공중합체 막내에 포괄법으로 고정화한 후 도파로 위에 스핀코팅법으로 제조하였다. 그리고, 센서의 특성을 평가하기 위해 감지막의 작용길이, 도파로의 두께 및 변색성 이온감응물질의 조성비 변화에 따른 감도 의존성을 조사하였다. 본 센서는 약 $1{\times}10^{-6}M\;{\sim}1.0\;M$의 넓은 측정범위를 가지며, 90%의 응답시간은 약 1분 이내의 빠른 응답특성을 나타내었다. 또한 분광분석법에 의한 투과광도법 및 광섬유를 이용한 optode형 센서를 제작하여 본 센서와 그 특성을 비교한 결과, 본 센서의 우수성을 알 수 있었다. 따라서 본 센서는 생화학 및 의용, 환경감시 분야 등에 응용 가능할 것으로 사료된다.

• 대한환경공학회지
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• 제37권2호
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• pp.92-98
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• 2015

알루미늄 호일 부식 실험을 이용하여 초음파 토양 세척 공정의 설계를 위한 기초 연구가 수행되었다. 36 kHz 초음파 발생 모듈이 하부에 장착된 대형 초음파 반응기에 파이렉스 재질의 소형 반응기를 위치시키고 글라스 비드 크기(1, 2, 4 mm), 파이렉스 반응기 내 글라스 비드 높이(5, 10, 15, 20 mm), 글라스 비드 위 물 높이(5, 10, 15, 20 mm) 등의 다양한 조건에서 실험을 진행하였다. 실험 결과, 글라스 비드의 입자 크기가 클수록, 글라스 비드 위 수위가 증가할수록 알루미늄 호일의 부식 정도가 크게 증가하였는데 이는 입자가 클수록 빈 공간이 많이 생겨 초음파 감쇠 현상이 덜 일어나게 되기 때문이며, 또한 수위가 증가할수록 동일한 에너지 유입 조건에서 초음파 캐비테이션 현상이 보다 활성화되기 때문으로 판단되었다. 그러나 글라스 비드를 지나면서 초음파 감쇠 현상이 심하게 일어나 알루미늄 호일의 부식 정도가 상대적으로 매우 약하게 확인되어 부식이 활발하게 일어나는 반응기 하부, 즉 심각한 초음파 감쇠 현상이 일어나지 않는 바닥 부분으로 입자들을 지속적으로 보낼 수 있는 기계적 교반 등의 방안이 제안되었다.

• 한국환경과학회지
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• 제12권12호
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• pp.1255-1260
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• 2003

Plasma-photocatalytic oxidation process was applied in the decomposition of Triethylamine(TEA) and Methyl ethyl ketone(MEK). Plasma reactor was made entirely of pyrex glass and consists of 24mm inner diameter, 1,800mm length and discharge electrode of 0.4mm stainless steel. And initial concentrations of TEA and MEK for plasma-photocatalytic oxidation are 100 ppm. Odor gas samples were taken by gas-tight syringe from a glass sampling bulb which was located at reactor inlet and outlet, and TEA and MEK were determined by GC-FID. For plasma process, the decomposition efficiency of TEA and MEK were evaluated by varying different flowrates and decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. For photocatalytic oxidation process, also the decomposition efficiency of TEA and MEK increased considerably with decreasing treatment flowrates. The decomposition efficiency of MEK was 57.8％, 34.2％, 18.8％ respectively and the decomposition efficiency of TEA was reached all 100％. This result is higher than that of plasma process only, From this study, the results indicate that plasma-photocatalytic oxidation process is ideal for treatment of TEA and MEK.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.641-644
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• 2005

The study on the interaction forces of some biological materials is important to understanding biological phenomena and their application to practical purpose. This paper introduces a measuring technique for biological adhesive forces using the AFM(Atomic Force Microscope). Since no standardized thesis on adhesive forces exist, the adhesive forces is defined as adhesive forces against a hardened surface of biological materials. To grant the results are meaningful, which is based on the understanding the surface characteristics of biological materials using the AFM, a nominal value of average adhesive force per unit area should be measured. Therefore the modified AFM probe with small micro glass bead was proposed so that it can guarantee the required contact area for measuring the average adhesive forces. A pyrex glass substrate with circular patterns, which was fabricated by micromachining technique, is introduced in order to controll the contact area. The two types of mussel adhesive proteins, Celltak and recombinant-MGFP5, were tested by the proposed measuring method. The test results show that the adhesive force of the mussel adhesive proteins can be reliably measured by use of this method.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.86-86
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• 2010

Micro- and nanoscale texturing and control of surface energy have been considered for superhydrophobicity on polymer and silicon. However these surfaces have been reported to be difficult to meet the robustness and transparency requirements for further applications, from self cleaning windows to biochip technology. Here we provided a novel method to fabricate a nearly superhydrophobic soda-lime glass using two-step method. The first step involved wet etching process to fabricate micro-sale patterns on soda-lime glass. The second step involved application of $SiO_x$-incorporated DLC to generate high intrinsic contact angle on the surface using chemical vapor deposition (CVD) process. To investigate the effect of surface roughness, we used both positive and negative micro-scale patterns on soda-limeglass, which is relatively hard for surface texturing in comparison to quartz or Pyrex glasses due to the presence of impurities, but cheaper. For all samples we tested the static wetting angle and transparency before and after 100 cycles of wear test using woolen steel. The surface morphology is observed using optical and scanning electron microscope (SEM). The results shows that negative patterns had a greater wear resistance while the hydrophobicity was best achieved using positive patterns having static contact angle up to 140 deg. with about 80% transparency. The overall experiment shows that positive patterns at etching time of 1 min shows the optimum transparency and hydrophobicity. The optimization of micro-scale pattern to achieve a robust, transparent, superhydrophobic soda-lime glass will be further investigated in the future works.

• 비파괴검사학회지
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• 제15권2호
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• pp.378-385
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• 1995

초음파검사는 초음파 펄스가 한 방향으로 진행한다고 하는 지향성을 이용하고 있다. 초음파의 지향성은 전파 방향과 음압 분포의 관계를 나타내고 있으며 탐촉자의 배치, 탐상 감도 및 주사 간격, 결함의 위치 및 특성의 결정에 밀접한 관계가 있다. 본 논문은 초음파가시화법을 이용하여 pyrex glass로 만든 가상 맞대기 용접부내의 용접 금속부에 위치한 인공 결함으로부터 산란한 반사 횡파의 지향성을 측정하였다. 2 MHz와 4 MHz의 사각탐촉자가 인공 결함에서의 반사파의 지향성 조사에 사용되었다. 인공 결함으로부터 반사된 횡파의 지향성은 사각탐촉자의 위치 및 가상 용접부의 형상에 따라 달랐으며 2 MHz와 4 MHz의 사각 탐촉자에 따라 반사파의 지향성은 큰 차이를 나타내고 있었다. 또한 가상 용접부의 높이가 커짐에 따라 반사각과 입사각은 비슷하게 되었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.116-119
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic restoration and pile-up was proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1-10nm Comparison between the experimental data and numerical result demonstrated that the finite element approach is capable of reproducing the loading-unloading behavior of a nanoindentation test. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.

• 한국정밀공학회지
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• 제20권5호
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• pp.210-217
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• 2003

In this study, to achieve the optimal conditions for mechanical hyper-fine pattern fabrication process, deformation behavior of the materials during indentation was studied with numerical method by ABAQUS S/W. Polymer (PMMA) and brittle materials (Si, Pyrex glass) were used as specimens, and forming conditions to reduce the elastic restoration and pile-up was proposed. The indenter was modeled a rigid surface. Minimum mesh sizes of specimens are 1-l0mm. The result of the investigation will be applied to the fabrication of the hyper-fine pattern and mold.