• 반도체디스플레이기술학회지
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• 제5권2호
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• pp.47-49
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• 2006

Various methods of making thin film is being used in semiconductor manufacturing process. The most common method in this field includes CVD(Chemical Vapor Deposition) and PVD(Physical Vapor Deposition). Thin film is deposited on both the backside and the frontside of wafers. The thin film deposited on the backside has poor thickness profile, and can contaminate wafers in the following processes. If wafers with the thin film remaining on the backside are immersed in batch type process tank, the thin film fall apart from the backside and contaminate the nearest wafer. Thus, it is necessary to etch the backside of the wafer selectively without etching the frontside, and chemical injection nozzle positioned under the wafer can perform the backside etching. In this study, the backside chemical injection nozzle with optimized chemical injection profile is built for single wafer tool. The evaluation of this nozzle, performed on $Si_3N_4$ layer deposited on the backside of the wafer, shows the etching rate uniformity of less than 5% at the etching rate of more than $1000{\AA}$.

• 제어로봇시스템학회논문지
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• 제14권11호
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• pp.1174-1179
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• 2008

Many modeling and calibration methods have been developed to analyze and design the biological wastewater treatment process. For the systematic use of activated sludge model (ASM) in a real treatment process, a most important step in this usage is a calibration which can find a key parameter set of ASM, which depends on the microorganism communities and the process conditions of the plants. In this paper, a standardized calibration protocol of the ASM model is developed. First, a weighted effluent quality index(WEQI) is suggested far a calibration protocol. Second, the most sensitive parameter set is determined by a sensitive analysis based on WEQI and then a parameter optimization method are used for a systematic calibration of key parameters. The proposed method is applied to a calibration problems of the single carbon removal process. The results of the sensitivity analysis and parameter estimation based on a WEQI shows a quite reasonable parameter set and precisely estimated parameters, which can improve the quality and the efficiency of the modeling and the prediction of ASM model. Moreover, it can be used for a calibration scheme of other biological processes, such as sequence batch reactor, anaerobic digestion process with a dedicated methodology.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.287-292
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• 2005

The crude polysaccharides(C-CPF, C-CPM, C-CPB) derived from fruiting body, mycelia and mycelia free broth of cordyceps militaris were obtained by ethanol precipitation of hot water extracts. After a batch fermentation of C. militaris was carried out in a 5 L jar vessel, endo-polysaccharide and exo-polysaccharide were obtained. They were demonstrated as the hetero polysaccharides which were composed of glucsose, galactose and mannose by performed with HPAEC(high pH anion exchange chromatography) and conformation of random coil by its complex forming ability with congo red reagent. They were purified by ion exchange (DEAE-cellulose) and gel filtration chromatography. They were monitered by phenol-sulfuric acid method and Bradford method. The NO induction activities of crude polysaccharides and purified polysaccharides derived from mycelia free broth were enhanced rather than LPS(lipo polysaccharide) which was used as a general NO inducer. These effects presumably contibute to the antitumor activities. The homogenieties and molecular weights of polysaccharides were determined by using Sepharose CL-6B. The yield, molecular weights and NO induction activities of C-CPFN Fr.III, C-CPMN Fr.III, C-CPBN Fr.II were 0.387, 0.408 and 0.153, 127 K 210 K and 36 K, 40.79%, 88.72%, and 104.17%, respectively.

• 한국세라믹학회지
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• 제48권1호
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• pp.40-45
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• 2011

In this study, the composition of optical glass for GMP(glass molding process) was designed with 'Design of Experiments' method. All the composition batch was performed by 'Create Factorial Design' method. Particularly, $SiO_2$, BaO and $Al_2O_3$ were chosen major parameters for investigating the effects of components on optical and thermal properties. BaO and $Al_2O_3$ strongly influenced on optical and thermal properties, respectively. Finally, the approximate values of desired optical and thermal values were obtained by microtuning of compositions. At the composition of $BaO:Al_2O_3:SiO_2$=10:4:48 (molar ratio), refractive index($n_d$) was 1.5833, coefficient of thermal expansion(CTE) was $104{\times}10^{-7}/^{\circ}C$.

• 한국생산제조학회지
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• 제25권3호
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• pp.237-243
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• 2016

Recently, technologies that produce biofuels from microalgae are being studied worldwide. It is necessary to significantly reduce the production costs of biofuels from microalgae for economic reasons. In this study, the growth curve of the microalgae was obtained using the batch-culture method, and the specific growth rate was predicted using the regression method. Based on the culture conditions of the estimated specific growth rate, the turbidity of the microalgae in the flat panel photobioreactor (PBR) was measured. Furthermore, an on-off control scheme was applied to the flat panel PBR in order to culture the microalgae continuously on the basis of turbidity. The parameters of the on-off control system were displayed by LabView. The on-off scheme of peristaltic pump was controlled based on the turbidity in the PBR. In addition, the turbidity values of growth curves were compared and analyzed in the continuous culture process using the on-off controller.

• 상하수도학회지
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• 제29권6호
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• pp.609-615
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• 2015

This study was carried out for characterization of MIO synthesized in our laboratory by co-precipitation method and applied isotherm and kinetic models for adsorption properties. XRD analysis were conducted to find crystal structure of synthesized MIO. Further SEM and XPS analysis was performed before and after phosphate adsorption, and BET analysis for surface characterization. Phosphate stock solution was prepared by KH2PO4 for characterization of phosphate adsorption, and batch experiment was conducted using 50 ml conical tube. Langmuir and Freundlich models were applied based on adsorption equilibrium test of MIO by initial phosphate solution. Pseudo first order and pseudo second order models were applied for interpretation of kinetic model by temperature. Surface area and pore size of MIO were found $89.6m^2/g$ and 16 nm respectively. And, the determination coefficient ($R^2$) value of Langmuir model was 0.9779, which was comparatively higher than that of Freundlich isotherm model 0.9340.

• 한국산학기술학회논문지
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• 제12권10호
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• pp.4696-4703
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• 2011

본 연구에서는 메리필드펩타이드 수지가 치환된 테트라아자거대고리 화합물인 1,4,8,11-tetraazacyclotetradecane bonded Merrifield peptide resin(TDM)과 1,4,8,12-tetraazacyclopentadecane bonded Merrifield peptide resin(TPM)을 합성 하였다. 합성된 이온교환수지의 이온교환용량을 측정하였고, 또한 여러 농도의 염화암모늄용액에서 마그네슘이온의 분포계수를 측정하였다. 새롭게 합성한 테트라아자거대고리 화합물(TDM, TPM)을 가지고 컬럼크로마토그래피법을 이용하여 마그네슘 동위원소를 분리하고 그 효용성을 논의하였다.

• 자원리싸이클링
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• 제12권4호
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• pp.44-50
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• 2003

혼합되어 배출되는 플라스틱을 분리 및 선별하기 위한 기존의 방법들은 플라스틱 비중의 유사성, 입도의 제한 등의 요인으로 인해 단일재질의 플라스틱으로 분리하는데 많은 어려움이 따른다. 본 연구에서는 플라스틱의 재질별 연화온도와 점착 특성이 다른 점에 착안하여 열 점착 방식을 이용하여 혼합 플라스틱을 분리하는 방식을 개발하고자 하였다. 일상생활에서 사용되는 범용수지를 시료로 이용, batch 방식의 실험장치를 제작하여 온도를 변화시키면서 각 플라스틱의 점착 온도 범위, 점착율을 실험적으로 조사하였다. 또한 접촉시간과 플라스틱의 착색제의 유무, 입자 크기 등 다양한 조건들을 변화시키면서 그에 따른 영향을 조사하였으며 이를 실제 혼합 폐 플라스틱에 적용하여 분리효율을 조사하였다. 실험 결과 혼합 플라스틱에서 비중이 유사한 LDPE와 HDPE, PET와 PVC, 그리고 PP와 PVC 등을 온도의 변화에 의해 선택적으로 분리할 수 있음을 확인하였다.

• Advanced Composite Materials
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• 제18권3호
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• pp.221-232
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• 2009

The allylamine plasma treatment is used to modify the surface properties of vapor grown carbon fibers (VGCF). It is to improve the interfacial bonding between the VGCF and epoxy matrix. The allylamine plasma process was performed by batch process in a vacuum chamber, using gas injection followed by plasma discharge for the durations of 20, 40 and 60 min. The interdependence of mechanical properties on the VGCF contents, treatment time and interfacial bonding between VGCF/ep was investigated. The interfacial bonding between VGCF and epoxy matrix was observed by scanning electron microscopy (SEM) micrographs of nanocomposites fracture surfaces. The changes in the mechanical properties of VGCF/ep, such as the tensile modulus and strength were discussed. The mechanical properties of allylamine plasma treated (AAPT) VGCF/ep were compared with those of raw VGCF/ep. The tensile strength and modulus of allyamine plasma treated VGCF40 (40 min treatment)/ep demonstrated a higher value than those of other samples. The mechanical properties were increased with the allyamine plasma treatment due to the improved adhesion at VGCF/ep interface. The modification of the carbon nanofibers surface was observed by transmission electron microscopy (TEM). SEM micrographs showed an excellent dispersion of VGCF in epoxy matrix by ultrasonic method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.553-556
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• 2008

전기전도도에 의한 콘크리트의 염소이온 침투저항성 시험방법에 의해 동일 배치의 10개의 콘크리트 공시체의 염소이온 투과시험을 실시하였다. 실험결과 동일한 배합의 시료에 대한 염소이온 투과시험 결과 변동계수가 24% 정도로 나타나고 있어, 이 방법에 의해 얻어진 데이터의 신뢰성은 그다지 높지 않다는 결론을 도출할 수 있었다. 이러한 오차는 구성 재료 자체의 불균질성, 배합상의 오차, 시험방법 상의 오차 등이 모두 복합적으로 작용하여 일어나는 것으로 얻어진 결과를 활용하고자 할 때 이러한 영향으로 인해 도입되는 오차의 범위를 고려하여야 할 것이다. 특히 1개의 공시체에 대한 1회의 시험값을 토대로 연구결과를 내려는 경우 큰 오류를 범할 수 있음을 주지해야 한다.