공기재생용 고온건식탈황제의 가압유동층 반응기에서의 사이클 성능실험

조성호,이봉희,이중범,류청걸,진경태,이창근 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.2

고온고압 기포유동층 반응기에서 분무건조기로 성형제조한 아연계 탈황제(ZAC C)에 대하여 총 6회 황화-재생 반복실험을 500℃, 5atm 조건에서 수행하였다. 1% H_2S를 포함한 석탄모사가스를 반응기에 주입하여 황화반응을 시킨 결과 배출가스 중 H_2S 농도는 10ppmv 이하로 유지되었다. ZAC C의 황흡수력은 6회 황화반응 동안 각각 11.1, 10.9, 11.1, 11.1, 10.9, 10.5g S/100g sorbent으로 유지되어 초기 황흡수력을 유지하였다. 공기를 이용한 500℃ 재생반응에서 배출되는 SO_2의 최대농도는 양론적으로 이론값과 일치하였다. 재생반응에서 탈황제 층의 온도는 발열반응에 의해 500℃에서 최대 750℃까지 상승하였다. 연속 70시간 동안 유동층 반응기내에서 실시된 ZAC C 탈황제의 비산되어 유출된 양은 1.07%이고, 실험 후 탈황제의 크기와 조직특성의 변화도 적었다. 고온고압반응기 multi-cyclone 실험결과 ZAC C 탈황제는 이론 황흡수력의 50% 이상을 유지하였고, 공기를 사용한 500℃의 재생반응이 원활하고 완전히 이루어졌고, 황산염생성과 같은 부반응이 없었다. Two desulfurization-regeneration experiments for a spray-dried zinc-based sorbent(ZAC C) were performed at 500℃ and 5 atm in a fluidized-bed reactor(ID 0.097㎜) facility. The H_S concentration after each desulfurization run was maintained below 10 ppmv from a simulated coal gas of 1% H_2S. The estimated sulfur absorption capacities of ZAC C sorbent were 11.1, 10.9, 11.1, 11.1, 10.9, 10.5 g S/100g sorbent, and the sorption capacity of sorbent was maintained in spite of six times sorption experiments. The maximum SO_2 concentration in regeneration effluent gas agreed with a stoichiometric value of 500℃(ca. 14vol%). In regeneration run, the peak temperature of sorbent bed in the reactor reached up to 750 due to the vigorous exothermicity of regeneration reaction with neat air. While entrainment rate for 70h continuous run in fluidized-bed reactor is 1.07%, the size and the textural properties of ZAC C sorbent also show a little change. Multi-cycle tests in fluidized-bed show that ZAC C sorbent maintains over 50% of its theoretical sorption capacity during 70h run and regeneration reaction undergoes smoothly and completely without side reactions such as sulfate formation.

Contributed Papers ( Poster Abstracts ) : Preparation of Artemisinate Derivatives from Artemisinic acid

Jeong Kul Lee,Sun Sik Min,Soo Un Kim 한국응용생명화학회(구 한국농화학회) 1994 한국응용생명화학회 학술발표회 Vol.1994 No.2

MR-Based Non-Alcoholic Steato Hepatitis (MASH) Score in Patients with Non-Alcoholic Fatty Liver Disease

( Young-sun Lee ),( Ji Eun Lee ),( Haein Bak ),( Sehwa Kim ),( Young Kul Jung ),( Ji Hoon Kim ),( Yeon Seok Seo ),( Hyung Joon Yim ),( Baekhui Kim ),( Jeong Woo Kim ),( Chang Hee Lee ),( Jong Eun Yeon 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: As prevalence of NAFLD accounts for up to 30% of the general population worldwide, non-invasive evaluation of disease severity of NAFLD and non-invasive diagnosis of NASH are important issues. The objective of this prospective cross-sectional study was to develop a diagnostic scoring system that could improve the accuracy of NASH diagnosis by combining multiparametric MR and clinical indicators. Methods: This study included 130 patients who were diagnosed NAFLD by liver biopsy from October 2016 to July 2019. All patients were examined for medical history, laboratory tests, and multiparametric MR consisting of MRI proton density fat fraction, MR spectroscopy, T1 mapping, and MR elastography (MRE). Scoring model was developed using logistic regression. Internal validation was performed using bootstrapping. Results: NASH patients were older (59 years vs. 46 years, P<0.001) and had lower BMI (28.23 kg/㎡ vs. 31.19 kg/㎡, P=0.032) than nonalcoholic fatty liver (NAFL) patients. NASH group showed higher prevalence of diabetes/impaired fasting glucose, hypertension, and dyslipidemia. Four categorical variables and 19 continuous variables were evaluated for NASH diagnostic model. Diabetes/IFG and hypertension among categorical variables and age, BMI, hemoglobin, platelet count, T1 mapping, and MRE among continuous variables met the criterion of P-value ≤ 0.1. Variable interactions were identified between BMI and hemoglobin, between platelet count and diabetes/IFG, and between platelet count and MRE. Finally, equation for MR-based NASH (MASH) score was obtained using four demographic factors, two laboratory variables, and two MRI parameters (Figure 1). MASH score showed satisfactory accuracy for NASH diagnosis (C-statistics: 0.892; 95% CI: 0.834-0.950; P<0.001). When MASH score of 0.73 was set as a cut-off for NASH diagnosis, its sensitivity was 0.67 and its specificity was 0.90 (PPV = 0.89, 47/53). When MASH score of 0.37 was set as a cut-off for NASH exclusion, its sensitivity was 0.90 and its specificity was 0.78 (NPV = 0.87, 47/54). Only 17% (22/130) of patients were located in the gray zone (Table 1). Internal validation using 1000 bootstrapping also showed satisfactory accuracy for NASH diagnosis (C-statistics: 0.909; 95% CI: 0.855-0.964; P<0.001). Conclusions: MASH score is a novel non-invasive biomarker for the diagnosis of NASH in patients with NAFLD. Further external validation is required for its clinical application.

담체가 Re-188-Hydroxyethylidene Diphosphonate의 표지와 생체내분포에 미치는 영향

장영수,이상은,이승진,이명철,이동수,정준기,정재민,조정혁,김보광,김인걸 대한핵의학회 2000 핵의학 분자영상 Vol.34 No.4

Purpose: Re-188-Hydroxyethylidene diphosphonate (HEDP) is a new cost-effective agent for systemic radioisotope therapy of metastatic bone pain. We investigated the influence of carrier for labeling and biodistribution of Re-188-HEDP using HEDP kit with or without carrier (KReO4). Materials and Methods: The kits (HEDP 15 mg, gentisic acid 4 mg and SnCl2.2H2O 4.5 mg) with or without carrier (KReO4 0.1 mg) were labeled with Re-188 solution, made available from an in-house generator by boiling for 15 min. We compared the labeling efficiency and stability of carrier-added and carrier-free preparations of Re-188-HEDP. Biodistribution and imaging studies of each preparation were performed in ICR mice (1.85∼3.7 MBq/0.1 ml) and SD rats (74.1∼85.2 MBq/0.5 ml). Results: The carrier-added preparation showed high labeling efficiency (95% at pH 5) and high stability in serum (88%, 3 hr). However, the carrier-free preparation showed low labeling efficiency (59% at pH 5) and low stability (43%, 3 hr). The carrier-added preration showed high uptake in bone and low uptake in stomach and kidneys. However, the carrier-free preparation showed lower uptake in bone and higher uptake in both stomach and kidneys, which is supposed to be due to released perrhenate. The carrier-added preparation also showed better images with higher skeletal accumulation, lower uptake in other organs and lower soft tissue uptake than the carrier-free preparation. Conclusion: The results of these studies clearly demonstrate that addition of carrier perrhenate is required for high labeling efficiency, stability, bone uptake and good image quality of Re-188-HEDP. (Korean J Nucl Med 2000;34:344-52)

INTERVAL-VALUED FUZZY SUBGROUPS

Lee, Jeong Gon,Hur, Kul,Lim, Pyung Ki The Honam Mathematical Society 2013 호남수학학술지 Vol.35 No.4

We study the conditions under which a given interval-valued fuzzy subgroup of a given group can or can not be realized as a union of two interval-valued fuzzy proper subgroups. Moreover, we provide a simple necessary and su cient condition for the unio of an arbitrary family of interval-valued fuzzy subgroups to be an interval-valued fuzzy subgroup. Also we formulate the concept of interval-valued fuzzy subgroup generated by a given interval-valued fuzzy set by level subgroups. Furthermore we give characterizations of interval-valued fuzzy conjugate subgroups and interval-valued fuzzy characteristic subgroups by their level subgroups. Also we investigate the level subgroups of the homomorphic image of a given interval-valued fuzzy subgroup.

Closure, Interior and Compactness in Ordinary Smooth Topological Spaces

Jeong Gon Lee,Kul Hur,Pyung Ki Lim 한국지능시스템학회 2014 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.14 No.3

It presents the concepts of ordinary smooth interior and ordinary smooth closure of an ordinary subset and their structural properties. It also introduces the notion of ordinary smooth (open) preserving mapping and addresses some their properties. In addition, it develops the notions of ordinary smooth compactness, ordinary smooth almost compactness, and ordinary near compactness and discusses them in the general framework of ordinary smooth topological spaces.

SINGLET OXYGEN-MEDIATED PHOTOOXIDATION OF METHYL 11-HYDRO-13-(METHYLOXY)CARBONYLARTEMISINATE

Lee, Jung-Kul,Han, Jae-Hong,Kim, Jeong-Han,Lim, Yoong-Ho,Kim, Soo-Un Korean Society of Photoscience 1994 Journal of Photosciences Vol.1 No.2

Singlet oxygen-mediated photooxidation and subsequent triplet oxygen insertion of 11-hydro-13-(methyloxy)carbonylartemisinate (4) yielded a diketo compound 5 as the major product instead of the expected 11-hydro-13-(methyloxy)carbonylartemisinin (6). The formation of the unexpected product was in part consistent with the mechanism proposed by Acton and Roth and is the first isolation of the diketo compound from the photooxidation of artemisinate.

INTERVAL-VALUED FUZZY GROUP CONGRUENCES

Lee, Jeong Gon,Hur, Kul,Lim, Pyung Ki The Honam Mathematical Society 2016 호남수학학술지 Vol.38 No.2

We introduce the concepts of interval-valued fuzzy complete inner-unitary subsemigroups and interval-valued fuzzy group congruences on a semigroup. And we investigate some of their properties. Also, we prove that there is a one to one correspondence between the interval-valued fuzzy complete inner-unitary subsemigroups and the interval-valued fuzzy group congruences on a regular semigroups.

NEIGHBORHOOD STRUCTURES IN ORDINARY SMOOTH TOPOLOGICAL SPACES

Lee, Jeong Gon,Lim, Pyung Ki,Hur, Kul The Honam Mathematical Society 2012 호남수학학술지 Vol.34 No.4

We construct a new definition of a base for ordinary smooth topological spaces and introduce the concept of a neighborhood structure in ordinary smooth topological spaces. Then, we state some of their properties which are generalizations of some results in classical topological spaces.

Characterization of xyn10J, a novel family 10 xylanase from a compost metagenomic library.

Jeong, Yu Seok,Na, Han Beur,Kim, Sung Kyum,Kim, Yong Ho,Kwon, Eun Ju,Kim, Jungho,Yun, Han Dae,Lee, Jung-Kul,Kim, Hoon Humana Press 2012 Applied biochemistry and biotechnology Vol.166 No.5

<P>A gene encoding an extracellular xylanase was cloned from a compost metagenomic library. The xylanase gene, xyn10J, was 1,137?bp in length and was predicted to encode a protein of 378 amino acid residues with a putative signal peptide of 27 amino acid residues. The molecular mass of the mature Xyn10J was calculated to be 39,882?Da with a pI of 6.09. Xyn10J had a motif GVKVHFTEMDI characteristic of most members of glycosyl hydrolase family 10. The amino acid sequence of Xyn10J showed 60.0% identity to that of XynH, a xylanase from an uncultured soil bacterium and 55% identity to XylC of Cellvibrio mixtus. Site-directed mutagenesis of the expected active site based on the sequence analysis indicated that an aspartic acid residue (Asp207), in addition to the identified catalytic residues Glu165 and Glu270, plays a crucial role for the catalytic activity. The purified Xyn10J had a mass of about 40?kDa and was optimally active at pH?7.0 and 40?C. Xyn10J hydrolyzed beechwood xylan?>?birchwood xylan?>?oat spelt xylan?>?arabinoxylan. Xyn10J hydrolyzed xylotetraose and xylohexaose exclusively to xylobiose, xylopentaose, and xylotriose mainly to xylobiose with transglycosylation activity. The saccharification of reed (Phragmites communis) powder by commercial enzymes was significantly increased by the addition of a small amount of Xyn10J to the commercial preparation. Xyn10J is the first xylanase screened directly from a compost metagenomic library, and the enzyme has the potential to be used in the conversion of biomass to fermentable sugars for biofuel production.</P>