Interaction of β-Cyclodextrin with Lipophilic Ring Compounds Deposited in a Sandy Soil Matrix during Flushing

조대철,이인형,Sang-Hyuk Youn 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

Chemical soil flushing in a packed sandy soil matrix using a natural surfactant, b-cyclodextrin (CD) wasinvestigated via a fluorescence spectroscopy and a dye labeling. The contaminants are lipophilic ring compounds -phenanthrene and naphthalene. Sand type and flushing intensity (rate and concentration) are critical investigationvariables. The removal efficiencies were proportional to flow rate, concentration, temperature of the flushing solutionand voidity of the sand column. Initial sorption of the surfactant onto the soil matrix was found to be a key step whileflow shear was more crucial in the later steps. From time delay experiments before flushing, we speculate that the com-plexation reaction appears to be rate-limiting in non-equilibrium washing schemes.

K-DOSE 60을 이용한 원전주변 주민 방사선 피폭선량 계산

조대철,이인형,이갑복 한국공업화학회 2003 한국공업화학회 연구논문 초록집 Vol.2003 No.-

대뇌 신경교종증 : 임상특징 및 예후에 관한 연구

조대철,황정현,성주경,황성규,함인석,박연묵,변승열,김승래,Jo, Dae-Chuol,Hwang, Jeong-Hyun,Sung, Joo-Kyung,Hwang, Sung-Kyu,Hamm, In-Suk,Park, Yeun-Mook,Byun, Seung-Yul,Kim, Seung-Lae 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.12

Objectives : Gliomatosis cerebri is an uncommon primary brain tumor characterized by diffuse neoplastic proliferation of glial cells, with the preservation of the underlying cytoarchitecture. The aim of this study is to evaluate clinical features, outcome of surgical treatment and adjuvant therapy of gliomatosis cerebri. Methods : Between Jan. 1990 and Dec. 2000, 12 patients were diagnosed with gliomatosis cerebri based on characteristic radiological and histological findings. The patients' age ranged from 18 to 77(mean 44) years and the male to female ratio was 7 : 5. Nine patients underwent decompressive surgery and three, biopsy only. Postoperative radiation therapy was given in all cases except three. In addition to radiation therapy, four patients received chemotherapy. The mean duration of follow-up period was 18.8 months. Results : The most common presenting symptom were seizure and motor weakness. The mean duration of symptom was 5.9 months. There was 5 bilateral lesions and tumor involved corpus callosum in 5, basal ganglia-thalamus in 4, and brain stem in 2. There was no operative mortality but four patients died during the follow-up. The mean survival period for 11 patients was 20.5 months from the time of diagnosis. In univariate analysis, the lesion involving corpus callosum, basal ganglia-thalamus and brain stem correlated significantly with the short length of survival(p<0.05). Also, postoperative radiation as a adjuvant therapy prolonged the patient's survival(p<0.05). Conclusions : In the management of gliomatosis cerebri patients, early detection by MR imaging, active management of increased intracranial pressure, decompressive surgical removal and postoperative adjuvant therapy such as radiation is thought to be a good treatment modality.

Stochastics and Artificial Intelligence-based Analytics of Wastewater Plant Operation

조대철,Sung-Hyun Kwon 한국청정기술학회 2023 청정기술 Vol.29 No.2

Tele-metering systems have been useful tools for managing domestic wastewater treatment plants (WWTP) over the last decade. They mostly generate water quality data for discharged water to ensure that it complies with mandatory regulations and they may be able to produce every operation parameter and additional measurements in the near future. A sub-big data group, comprised of about 150,000 data points from four domestic WWTPs, was ready to be classified and also analyzed to optimize the WWTP process. We used the Statistical Product and Service Solutions (SPSS) 25 package in order to statistically treat the data with linear regression and correlation analysis. The major independent variables for analysis were water temperature, sludge recycle rate, electricity used, and water quality of the influent while the dependent variables representing the water quality of the effluent included the total nitrogen, which is the most emphasized index for discharged flow in plants. The water temperature and consumed electricity showed a strong correlation with the total nitrogen but the other indices’ mutual correlations with other variables were found to be fuzzy due to the large errors involved. In addition, a multilayer perceptron analysis method was applied to TMS data along with root mean square error (RMSE) analysis. This study showed that the RMSE in the SS, T-N, and TOC predictions were in the range of 10% to 20%.

화학적 토양플러싱의 일반적 모델링

조대철 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.2

토양은 다양한 성분과 복잡한 구조를 가진 물질이다. 토양 플러싱은 토양정화의 좋은 도구이지만 합리적 계산 없이 여러 가지 계면활성제와 유기용제가 사용되어 왔다. 따라서 모델링은 화학적 토양세정에서 매우 중요한 도구이며 본 고에서는 용해 및 이동 그리고 흡착 동력학을 근간으로 토양 bed에서의 플러싱 모델을 제시하였다. 오염물 제거에는 실험에서 확인된 것과 같이 유가식 첨가방식이 연속식보다 훨씬 우수함을 보여준다.

고분자 물질의 표면처리에 따른 미생물 점착

조대철 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.2

폴리우레탄 거품수지를 대기압 플라즈마와 표면 그라프팅 중합반응을 이용하여 표면개질하였다. 플라즈마 반응으로 폴리우레탄의 표면에 과산화기가 도입되었다. 또한 아크릴산의 그라프트 공중합을 통하여 카르복시기가 형성되었다. 이와 같이 개질된 폴리우에탄 시료를 일반 미생물 점착시헌에 사용하였다. 점착시험으로 표면 개질방법에 따른 미생물 점착성을 조사하였다. 그 결과 그라프트 공중합 개질한 시료의 점착성이 전혀 표면개질이 없었던 시료나 플라즈마 처리만 된 시료보다 약 3배이상 높게 분석되었다. 세균의 양은 주사전자현미경으로 측정하였다.

후두와 동정맥 기형의 임상분석

조대철,황정현,함인석,성주경,황성규,박연묵,김승래 釜山醫師會 2001 釜山醫師會誌 Vol.37 No.12

담체 변화에 따른 Labscale 바이오 필터의 성능 실험

조대철,권성현 한국산학기술학회 2003 한국산학기술학회 학술대회 Vol.- No.-

The low-pH biofiltration system in laboratory experiments demonstrate defectiveperformance for treating H₂S. When leachate pH was in the range of 1.5 tO₄. the biofilters in three different media removed H₂S with efficiencies greater than 99% while it was treated as a single contaminant. The posibility of using a single-stage low pH biofilter depends on its performance in treating VOCs. During Phase 2. a single-stage biofilter was effective for treating mixtures of H₂S and toluene with toluene concentrations below 20ppm and leachate pH between 2 and 3.5. Biofiltration of xylene was ineffective when pH was lower than 1.5. The treatment sysytem acclimated most slowly to benzene, and treatment of benzene was apparently subject to some competive inhibition from xylene and toluene. However, co-treatment was possible after some acclimation time. Xylene was not easily treated, with higher elimination capacities and no sign of competitive inhibition.

바이오필터의 기계적 세포성장 모델

조대철 순천향대학교 부설 산업기술연구소 2000 순천향 산업기술연구소논문집 Vol.6 No.2

A mechanistic growth model with a simple flux-dependent diffusion limitation was proposed in order to investigate bacterial growth and decay on the surfaces of media particles used in biofiltration. The size of media particles was estimated to be slightly dependent on the number of active cells as well as the thickness of the attached cell layers. In the model, the flux ratio was almost constant over time (about 3 days) and the natural cell decay rate would strongly affect on both cell growth and decay. A simulated prediction of cell growth was compared to one of experimental data.

A solid control strategy for preparation of silver nanoparticles in aqueous medium

조대철,권성현 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

Uniformly distributed, spherically shaped, mild concentrated silver nanoparticles with single-digit to hundreds nm size have been prepared by reducing silver nitrate with popular reducers like sodium borohydride or hydrazine in the presence of ordinary stabilizers such as SDS, PVP, Polysorbates and ultrasonication. Uv-visble spectroscopic analysis, particle size analysis, and particle-imaging through transmission electron microscopy (TEM) were used for nanoparticle characterization. Higher temperature accelerated the reduction rates, which follows the typical autocatalytic kinetics. Particularly, ultrasonication helped to facilitate the crucial stage of reduction phase to result in excellent quality of nanosolution, such as narrow distribution of particles and size uniformity. We found that initial location or arrangement of silver ions in clouds of stabilizers and ‘effectve mixing’ in the stage of reduction were vital for successful preparation of silver nanosolution. Also, reagent/stabilizer ratio, reducer input, solution environment such as pH, temperature, and stabilizer properties were optimized and discussed in detail. Proper selection of stabilizer and molar ratio to reagent and effective ‘mixing’ for preventing grain growth needs to be investigated more in the future work.