A comparative study of hybrid models combining various kinetic and regression models for p-xylene oxidation

Yaming Dong,Xuefeng Yan 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

The hybrid modeling approach, which combines kinetic and regression module parts to an overall processmodel, is an attractive process modeling approach. However, the selection of various kinetic and regression modelsaffects the hybrid model performance. As an illustrating example, we investigated the p-xylene (PX) oxidation processand summarized the published results of the PX oxidation kinetic model. The kinetic parameters of three kinetic models(i.e., three frequently used kinetic models of PX oxidation) were estimated and the fitting results were evaluated. Sixhybrid models were then developed based on these three kinetic models and two regression models (artificial neuralnetwork and support vector regression). Afterwards, a comparative study of the six hybrid models was carried out basedon various kinetic and regression models. The performances of these kinetic and regression models on the hybrid modelswere also evaluated. Finally, the best suitable hybrid model was obtained for the PX oxidation process.

기동형 건축요소의 성능지향적 설계를 위한 물리 모델-디지털 모델간 상호연동 방법론 제안

장도진(Jang, Do-Jin),김성아(Kim, Sung-Ah) 대한건축학회 2016 대한건축학회논문집 Vol.32 No.1

Kinetic building components, which respond to the changing environmental conditions or user demands, need different design process from traditional static building components. For performance-oriented design of kinetic building components with dynamic movements, interwoking between the physical model and the digital model via physical computing is advantageous. Even though the digital model can control the actuators of physical model in real-time, the two models cannot correspond with each other, due to physical conditions including material properties and the surrounding environment. For accurate evaluation performance, the shape and motion of physical model needs to be reflected in the digital model. This study aimed to devise a motion-capture-based system of interworking between physical and digital models. The motion-capture data of the physical model can be used for verification of the deviation between it and digital model and, based on its shape, for optimization of Kinetic building components operation.

Mass transfer kinetics using two-site interface model for removal of Cr(VI) from aqueous solution with cassava peel and rubber tree bark as adsorbents

M. Vasudevan,P. S. Ajithkumar,R. P. Singh,N. Natarajan 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

Present study investigates the potential of cassava peel and rubber tree bark for the removal of Cr (VI) from aqueous solution. Removal efficiency of more than 99% was obtained during the kinetic adsorption experiments with dosage of 3.5 g/L for cassava peel and 8 g/L for rubber tree bark. By comparing popular isotherm models and kinetic models for evaluating the kinetics of mass transfer, it was observed that Redlich-Peterson model and Langmuir model fitted well (R2 > 0.99) resulting in maximum adsorption capacity as 79.37 mg/g and 43.86 mg/g for cassava peel and rubber tree bark respectively. Validation of pseudo-second order model and Elovich model indicated the possibility of chemisorption being the rate limiting step. The multi-linearity in the diffusion model was further addressed using multi-sites models (two-site series interface (TSSI) and two-site parallel interface (TSPI) models). Considering the influence of interface properties on the kinetic nature of sorption, TSSI model resulted in low mass transfer rate (5% for cassava peel and 10% for rubber tree bark) compared to TSPI model. The study highlights the employability of two-site sorption model for simultaneous representation of different stages of kinetic sorption for finding the rate-limiting process, compared to the separate equilibrium and kinetic modeling attempts.

60Co 에어로졸의 내부피폭 선량평가를 위한 ICRP 생체역동학 모델 비교분석

이상경,김정민 (사)한국방사선산업학회 2020 방사선산업학회지 Vol.14 No.4

Radioactive aerosols generated during the decommissioning or decontamination innuclear power plants can be deposited in the body due to workers’ inhalation, and become a majorcontribution in the internal exposure. Therefore, the internal dosimetry is an important procedurefor probably preventing the over-exposure of workers. The bio-kinetic models recommended bythe ICRP are applied to calculate the committed effective dose and bio-assay functions of workers,and used in codes for the internal dosimetry. Organs in the body can be represented as a seriesof mathematical compartments according to the bio-kinetic models (the respiratory tract model,alimentary tract model and systemic model). Recently, the ICRP has issued publications on thenew bio-kinetic models. In this study, we investigated the differences between the previous biokineticmodels and the revised bio-kinetic models of 60Co, which is one of radioactive aerosolsand an important activation product generated during the operation of nuclear power plants. Comparative analysse of the retention fraction and daily excreta fraction of inhaled 60Co aerosolhave shown that the difference between two bio-kinetic models is clear, so the revised bio-kineticmodels must be used in the internal exposure calculation codes.

03 구두발표 : 구두발표(OA) - 농업환경 및 토양,수질 분야 ; OA-03 : 사양토에서 왕겨 바이오차 시용에 따른 암모늄태 질소(NH4-N) 흡착특성 및 반응속도

최용수 ( Yong Su Choi ),김성철 ( Sung Chul Kim ),신중두 ( Joung Du Shin ) 한국환경농학회 2015 한국환경농학회 학술대회집 Vol.2015 No.-

Objective of this study was to investigate adsorption characteristic and kinetic model of NH4-N to biochar produced from rice hull in respective to mitigation of greenhouse gases. NH4-N concentration was analyzed by UV spectrophotometer. For the experiment, the soil texture used in this study was sandy loam, and application rate of chemical fertilizer and pig compost were 420-200-370 kg ha-1 (N-P-K) and 5,500 kg ha-1 as recommended amount after soil test for corn cultivation. Biochar treatments were 0.2-5% to soil weigh. Its adsorption characteristic was investigated with application of Langmuir isotherm, and pseudo-first order kinetic model and pseudo-second order kinetic model were used as kinetic models. Adsorption amount and removal rates of NH4-N were 39.3 mg g-1 and 28.0% in 0.2% biochar treatment, respectively. The sorption of NH4-N to biochar was fitted well by Langmuir model because it was observed that dimensionless constant (RL) was 0.48. The maximum adsorption amount (qm) and binding strength constant (b) were calculated as 4.1 mg g-1 and 0.01 L mg-1 in Langmuir isotherm, respectively. The pseudo-second order kinetic models was more appropriate than pseudo-first order kinetic model for high correlation coefficient (r2) of pseudo-second order kinetic model. Therefor, biochar produced from rice hull could reduce N2O by adsorbing NH4-N to biochar cooperated in sandy loam.

Modified Two-Compartment First-Order Kinetic Model (MTCFOKM)을 이용한 퇴적물에 대한 Ibuprofen의 빠른 및 느린 수착의 동력학 해석

오상화 ( Sang Hwa Oh ) 한국수처리학회 2015 한국수처리학회지 Vol.23 No.5

Ibuprofen is a nonsteroideal anti-inflammatory drug (NSAID) widely used as a pain reliever and therefore, has been frequently detected in rivers, lakes and even their sediments. However, few data have been available for the fate of ibuprofen in the water/sediment compartment despite its high pKow (=3.5). This study focused on the dynamic sorption of ibuprofen onto sediment at pH 4 and 0 and 30 ppt (part per thousand) of salinity. Experimental data were fitted to several kinetic models such as one-site mass transfer model (OSMTM), pseudo-first order kinetic model (PFOKM), pseudo-second order kinetic model (PSOKM), two compartment first order kinetic model (TCFOKM), and modified two compartment first order kinetic model (MTCFOKM). The MTCFOKM was the best in fitting sorption data (R2 > 0.991 and 0.985 at 0 and 30 ppt salinity, respectively). The MTCFOKM can fit the data into the fast and slow sorption kinetics. The results show that the fast sorption of ibuprofen finished within 1 day, whereas the slow sorption finished between 10 and 100 days. Salinity increases the sorbed amount of ibuprofen (qe) and affects also the finish time for the fast and slow sorption. The increase in salinity decreased the finish time for the fast sorption whereas increased it for the slow sorption.

충돌 검출을 이용한 지그 키네틱 모델링 방법론

정용호(Yong Ho Chung),함원경(Won K. Hwam),박상철(Sang Chul Park),최정주(Jung Ju Choi) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

This paper proposes algorithm for efficient fixture modeling for automotive body assembly line that should be remodeled frequently whenever changes of design occur. A fixture model consists of geometric model and kinetic model. We develop an algorithm extracting kinetic model from geometric model. In automotive body assembly lines, Kinetic models of fixtures mostly follow the same mechanism, the so-called slider-crank mechanism; this is a four-axis system of three revolute and one prismatic joint. It is very important to identify the prismatic axis from a given geometric model to extract the kinetic model of a fixture. We employ the concept of collision detection. The result of collision detection is a Boolean saying whether two or more objects collide.

고급강 제조 반응 모델의 검토 : Part. 2. 종합 모델 및 단일 반응 모델

김정인,김선중 한국자원리싸이클링학회 2021 資源 리싸이클링 Vol.30 No.1

As a demand of high-end steel raises, the importance of secondary refinement process also increases. However, the content of each component in molten steel, slag and inclusions change with the time, meaning the secondary refinement process is not an equilibrium state. Furthermore, many reactions occur between molten steel, slag, inclusion, refractory and alloying element during secondary refinement process. In order to consider the above complex reactions with non-equilibrium state, a few researchers developed kinetic models in secondary refinement process based on the experimental numerical equations. It is important to analyze and review to the previously reported models to develop a precise model. Therefore, in present study, the complex reaction models based on kinetic in secondary refinement process were analyzed, reviewed, and introduced. Moreover, the single reaction models also introduced which would be applied to the complex reaction models. 고품질 철강의 수요가 증가함에 따라 2차 정련 공정의 중요성이 높아지고 있다. 하지만 공정 시간에 따라 변화하는 용강, 슬래그 및 비금속 개재물의 조성은 정련 공정이 평형 상태가 아님을 의미하며, 정련 공정에서는 용강, 슬래그, 비금속 개재물, 내화물 및 합금 원소 간의 동시 다발적 반응이 일어난다. 다양한 상들의 비평형 상태에서 복잡한 반응을 고려하기 위해, 이전 연구자들은 실험을 통해 도출된 반응 속도 수식들을 기반으로 kinetic 기반의 고급강 제조 정련 시뮬레이션 모델을 발표하였다. 정밀한 시뮬레이션 모델의 개발을 위해 보고된 2차 정련 모델들의 분석 및 검토가 필요하다. 본 연구에서는 국내외로 발표된 정련 공정 관련 종합 모델들 및 단일 반응 모델들에 대하여 검토하고 소개하였다.

Adsorption Characteristics and Kinetic Models of Ammonium Nitrogen using Biochar from Rice Hull in Sandy Loam Soil

Yong-Su Choi,Sung-Chul Kim,Joung-Du Shin 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.5

Objective of this study was to investigate adsorption characteristics and kinetic models of NH₄-N to biochar produced from rice hull in respective to mitigation of greenhouse gases. NH₄-N concentration was analyzed by UV Spectrophotometer. For the experiment, the soil texture used in this study was sandy loam soil, and application rates of chemical fertilizer and pig compost were 420-200-370 kg ha<SUP>-1</SUP> (N-P-K) and 5,500 kg ha<SUP>-1</SUP> as recommended amount after soil test for corn cultivation. Biochar treatments were 0.2-5% to soil weight. Its adsorption characteristic was investigated with application of Langmuir isotherm, and pseudo-first order kinetic model and pseudo-second order kinetic model were used as kinetic models. Adsorption amount and removal rates of NH₄-N were 39.3 mg g<SUP>-1</SUP> and 28.0% in 0.2% biochar treatment, respectively. The sorption of NH₄-N to biochar was fitted well by Langmiur model because it was observed that dimensionless constant (RL) was 0.48. The maximum adsorption amount (qm) and binding strength constant (b) were calculated as 4.1 mg g<SUP>-1</SUP> and 0.01 L mg<SUP>-1</SUP> in Langmuir isotherm, respectively. The pseudo-second order kinetic model was more appropriate than pseudo-first order kinetic model for high correlation coefficient (r<SUP>2</SUP>) of pseudo-second order kinetic model. Therefore, biochar produced from rice hull could reduce N₂O by adsorbing NH₄-N to biochar cooperated in sandy loam soil.

Adsorption Characteristics and Kinetic Models of Ammonium Nitrogen using Biochar from Rice Hull in Sandy Loam Soil

최용수,신중두,김성철 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.5

Objective of this study was to investigate adsorption characteristics and kinetic models of NH4-N to biochar produced from rice hull in respective to mitigation of greenhouse gases. NH4-N concentration was analyzed by UV Spectrophotometer. For the experiment, the soil texture used in this study was sandy loam soil, and application rates of chemical fertilizer and pig compost were 420-200-370 kg ha-1 (N-P-K) and 5,500 kg ha-1 as recommended amount after soil test for corn cultivation. Biochar treatments were 0.2-5% to soil weight. Its adsorption characteristic was investigated with application of Langmuir isotherm, and pseudo-first order kinetic model and pseudo-second order kinetic model were used as kinetic models. Adsorption amount and removal rates of NH4-N were 39.3 mg g-1 and 28.0% in 0.2% biochar treatment, respectively. The sorption of NH4-N to biochar was fitted well by Langmiur model because it was observed that dimensionless constant (RL) was 0.48. The maximum adsorption amount (qm) and binding strength constant (b) were calculated as 4.1 mg g-1 and 0.01 L mg-1 in Langmuir isotherm, respectively. The pseudo-second order kinetic model was more appropriate than pseudo-first order kinetic model for high correlation coefficient (r2) of pseudo-second order kinetic model. Therefore, biochar produced from rice hull could reduce N2O by adsorbing NH4-N to biochar cooperated in sandy loam soil.