• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.191-199
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• 2021

A distillation column, which is a main facility of the chemical process, separates the desired product from a mixture by using the difference of boiling points. The distillation process requires the optimization and the prediction of operation because it consumes much energy. The target process of this study is difficult to operate efficiently because the composition of feed flow is not steady according to the supplier. To deal with this problem, we could develop a data-driven model to predict operating conditions. However, data preprocessing is essential to improve the predictive performance of the model because the raw data contains outlier and noise. In this study, after optimizing the predictive model based long-short term memory (LSTM) and Random forest (RF), we used a low-pass filter and one-class support vector machine for data preprocessing and compared predictive performance according to the method and range of the preprocessing. The performance of the predictive model and the effect of the preprocessing is compared by using R2 and RMSE. In the case of LSTM, R2 increased from 0.791 to 0.977 by 23.5%, and RMSE decreased from 0.132 to 0.029 by 78.0%. In the case of RF, R2 increased from 0.767 to 0.938 by 22.3%, and RMSE decreased from 0.140 to 0.050 by 64.3%.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.112-112
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• 2012

스포츠웨어 중 바람막이제품의 용도에 사용되는 소재는 폴리에스터와 폴리아미드 소재가 주류이며, 그 중에서 고품격의 바람막이 제품에 대해서는 주로 나일론6 소재를 사용하고 있다. 최근 소비자들은 삶의 질 향상과 야외활동의 증가로 인해 제품의 경량화, 안락한 착용감, 고기능성 등을 동시에 겸비한 제품을 요구하고 있다. 이러한 수요에 발맞추어 국내에서 많이 생산되고 있는 나일론6 소재를 이용하여 제품화 간계에서 경량감과 신축성이 발현될 수 있는 나일론6 소재의 경량 신축직물에 대한 연구개발이 요구되고 있다. 본 연구에서는 직물 단계에서의 경량감과 신축성이 발현될 수 있는 나일론6 소재 신축직물을 개발하기 위해 공중합 나일론6 폴리머와 일반 나일론6 폴리머를 복합방사 설비를 이용하여 side by side POY 26d/6f의 원사를 제조한 후 가연공정을 거쳐 개발된 DTY 20/6f 가연사를 직물 설계 시 위사방향으로 적용하여 제직을 실시하였다. 직물 설계 조건은 기존 T사에서 생산중인 나일론 DTY 20d/7f을 경사로, 개발 소재인 DTY 20/6f을 위사에 적용하였으며, 제직 시 경사밀도 2가지, 위사밀도 2가지로 설계하였으며, 조직의 변화에 따른 신축특성의 변화를 확인하기 위해 평직, Rib. 도비직으로 제직하였고, 이렇게 제조된 직물에 대해 전처리, 염색, 후가공, 코팅가공 공정 조건별로 테스트를 진행한 후, 신축성발현을 위한 최적 공정조건 확보를 위한 공정별 직물의 신축성 변화분석과 최적 공정을 통해 개발한 최종 직물에 대한 신축성 평가를 실시하였다. 테스트 결과, 제직 조건별로는 경사밀도와 위사밀도가 낮은 경우가 원단 내 수축이 더욱 많이 발생함으로써, 신축성이 향상됨을 알 수 있었으며, 조직별로는 평직, Rib. 도비직 순서로 신축성이 우수함을 알 수 있었다. 또한 공정별 신축성 변화분석 결과, 염색 시 가장 신축성 발현이 두드러지게 높은 것으로 나타났으며, 전처리는 일반 연속식 전처리 보다 CPB 전처리 공정이 이후 염색가공 및 코팅을 통해 제조된 직물의 신축성 향상 및 표면 평활성에 높은 기여를 하는 것을 알 수 있었다. 상기 조건에 서 얻어진 최적 공정 조건으로 제조된 최종 코팅직물의 경우에 22% 정도의 신축성이 나타나 개발 소재의 신축특성이 우수함을 확인하였다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.320-323
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• 2004

두가지 처리방법을 연계처리하여 실험한 결과 펜톤산화를 전처리로 적용하여 실험한 경우가 COD와 Color의 제거면에서 더 높은 처리효율을 보이고 있으며 본 연구의 실험 목적인 RFP상의 수질기준을 만족하였다. 배출수 수질 기준이 강화된 RFP상의 수질기준을 만족하기 위한 고도산화방법의 연계처리방법 중 오존산화와 펜톤산화를 조합한 결과 유기물과 색도를 고루 제거하는 펜톤산화를 전처리 공정으로 적용하고 유기물의 제거보다는 색도제거에 더 효율적인 오존처리 공정을 후처리로 둔 조합공정이 더 적합한 것으로 판단된다.

• Membrane Journal
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• v.14 no.3
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• pp.230-239
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• 2004

Treatment of a dyeing wastewater was carried out using polyamide RO-membranes. Before applying the wastewater to the membrane process, it was pretreated with various chemical coagulants such as alum, ferric chloride and HOC-100A. In order to see the effect of the pretreatment on the membrane separation process, the optimum conditions for the coagulation and sedimentation process were sought. As a result, by the pretreatment, for all the coagulants used, the chemical oxygen demand (COD) and UV-absorbance of the wastewater were lowered by more than 70%. The pretreated wastewater was then applied to the membrane process. The effect of the coagulants used for the pretreatment on the membrane fouling was studied. From this study, it was found that the HOC-100A was the best out of the coagulants used for the removal of the materials that could cause membrane fouling.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.430-435
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• 2014

Physical and chemical barriers, caused by the close association of the main components of cellulosic biomass, hinder the hydrolysis of cellulose to fermentable sugars. Since the main goal of pretreatment is to increase the enzyme accessibility improving digestibility of cellulose, development of an effective pretreatment process has been considered to be important. In this study, SAA (Soaking in Aqueous Ammonia) was chosen as pretreatment because this is the simple and low-cost method. Rice straw of which the production is outstandingly high in domestic agriculture residues in Korea was chosen as raw material. SSA pretreatment with various reaction time of 3 h to 72 h was tested. The enzymatic hydrolysis and SSF (Simultaneous Saccharification and Fermentation) were performed at three different temperature (30, 40 and $50^{\circ}C$) to investigate performance of SSF upon various pretreatment conditions. As a result, this SAA treated-rice straw was found to have great potential for effective enzymatic hydrolysis and SSF with lower enzyme dosage at lower temperature ($30^{\circ}C$) than its conventional SSF. In SAA addition, SAA reduced fermentation time to 24 h owing to increase the initial hydrolysis rate substantially.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2002.05a
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• pp.117-118
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• 2002

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.117-126
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• 2012

This study was conducted to assess the levels of microbiological hazards of preprocessed Namuls, which were served at the school foodservice. 19 preprocessed ground or root vegetables were collected from 21 schools in May to June of 2011. Heavy contamination of aerobic plate counts (from 3.39 to 8.42 logCFU/g) and total coliform groups (from 3.16 to 7.84 logCFU/g), enterobacteriaceaes (from 2.53 to 7.55 logCFU/g) were detected in preprocessed Namuls. In addition, the detection rates of Escherichia coli, Staphylococcus aureus and Bacillus cereus (emetic form) were 4.3%, 11.7% and 2.1%, respectively. In addition, sanitary indicative bacterium at preprocessing steps of root vegetables (lotus root, burdock root, bellflower root) and blanched Namuls (bracken, sweet potato vine, chinamul) were analyzed. Aerobic plate counts, coliform groups, and enterobacteriaceaes were not effectively removed during preprocessing including washing and soaking steps. In the case of blanched Namuls (bracken, sweet potato vine, chinamul), contamination levels increased more after drying process and no significant reduction effect on the levels of microbial contamination was observed during preprocessing steps. Thus, effect of preprocessing steps on the microbiological hazards in Namuls must be reevaluated to improve the microbiological quality of preprocessed Namuls at the school foodservice and retail markets.

• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• Textile Coloration and Finishing
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• v.11 no.2
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• pp.1-8
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• 1999

이 연구에서는 사이징 공정을 포함해서 수세, 전처리 그리고 최종 열처리 둥의 염색.가공 공정에서의 습열 및 건열 처리 온도가 폴리에스테르 직물의 열응력과 염색성에 미치는 영향을 조사하였다. 사용된 폴리에스테르 필라멘트사는 경사가 50d/24f 스파크사이며 위사는 75d/72f semi-dull사이다. 평직물은 션틀직기, 주자직물은 water jet 직기로 제직하였으며, sizing dryer 온도는 $90^\circ{C}$, $125^\circ{C}$, $150^\circ{C}$, 수세공정의 습열처리 온도는 $90^\circ{C}$, $110^\circ{C}$, $120^\circ{C}$, 전처리 공정의 건열처리 온도는 $180^\circ{C}$, $200^\circ{C}$, $220^\circ{C}$, 마지막 세팅 공정의 건열처리 온도는 $170^\circ{C}$, $180^\circ{C}$, $200^\circ{C}$로 변화시켰다. 이들 습열과 건열처리 온도 변화에 따른 직물내의 필라멘트사의 열 수축률과 직물의 겉보기 염색성의 변화를 조사 분석하였다.

• Resources Recycling
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• v.24 no.2
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• pp.55-61
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• 2015

In this study, mechanical properties of waste ground rubber tire powder were investigated to evaluate the influence of pre-treatment process for recycling. The tensile test, fracture test and morphology observation were carried out using various kinds of waste ground tire powders, which were produced by grinding and devulcanization process, respectively. As a results, it was found that the produced rubber powder through grinding process increased its tensile strength and elongation with decreasing particle size because of decreasing surface area. Devulcanized rubber powder also increased its tensile strength and elongation by de-crosslink with sulfur. It could be also suggested that devulcanization treatment after grinding process was more efficient recycling process for both increasing tensile property and fracture elongation of waste ground rubber tire powders.