http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ce_(0.8)Zr_(0.2)O₂ 촉매를 이용한 Dimethyl Carbonate 합성에서 탈수제 첨가의 영향
한기보,전진혁,박노국,이종대,류시옥,이태진,이병권,안병성 한국공업화학회 2004 응용화학 Vol.8 No.1
The effect of dehydrating agent in DMC(dimethyl carbonate) synthesis from methanol and carbon dioxide over Ce_(0.8)Zr_(0.2)O₂ catalyst was studied in this work. Ce_(0.8)Zr_(0.2)O₂ catalyst having the best activity among Ce_(1-x)Zr_(x)O₂ catalysts was selected. We could supposed that the addition of dehydrating agents improved the DMC yield by H₂O elimination. When the dehydrating agents such as Na_(2)SO₄ or K₂SO₄ was added into the synthesis of DMC, the formation amount of DMC increased to about 0.8∼0.9 mmol through the elimination of formed H₂O as by-product.
사철나무 알칼로이드, Euojaponine의 NMR스펙트럼의 분석
柳載夏,李沼映,李叔淵,韓秉勳 숙명여자대학교 약학연구소 1994 약학논문집-숙명여자대학교 Vol.10 No.-
The strutures of euojaponines, alkaloidal components from Euonymus japonica are composed of β-agarofuran type sesquiterpene and pyridic dibasic acid, and they are linked via cyclodiester bonds. The structures of these compounds were elucidated by the application of various two dimensional NMR methods. From the results of complete interpretation of NMR spectra, several correlating aspects between structure and spectral pattern of sesquiterpene moiety were found, which can be utilized for the structural determination of the same family compounds.
강안수,이병철,이한섭,안형환,이영주,류운형 明知大學校 産業技術硏究所 1993 産業技術硏究所論文集 Vol.12 No.-
For elucidation of various parameter's effect on the reactive extraction of organic acidstrioctylamine(TOA)-diluents system, the association model, equilibrium constants and extraction factors(loading) were investigated . The organic acids rosed were propionic. succinic, masonic, and benzoic acid. Extractant was tertiary amine, TOA and diluents were butylaeohol, hexane, and benzene. It was concluded that the loading of monobasic acid of propionic acid were higher than that of dibasic acids of oxalic, and malonic acid with extranctant TOA. In the extraction of monobasic acid the extraction factor was not affected by the initial concentration of extractant amine, but in the extraction of dibasic acids the extraction factor was getting better with decreasing the initial concentration of amine. There was a strong effect of diluents upon the extractien factor, and the order of these factor was as shown below: xylene<Benzene<butylalcohol<choloroform<methylisobutylketone.
이송우,나영수,김도한,류동춘,최동훈,류병순,송승구 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1
본 연구는 무연탄으로 활성탄을 제조할 경우 성형이 세공특성에 미치는 효과를 고찰한 것이다. 3가지 다른 방법으로 활성탄(파쇄형 활성탄, 압축성형 활성탄, 압축성형 활성탄)을 제조하여 특성을 비교했다. 이중에서 25%의 콜타르와 7%의 물을 혼합하여 압출 성형한 활성탄이 비표면적, 세공부피, 그리고 경도에서 가장 좋은 물성을 나타내었다. 압축 및 압출 성형체의 표면은 무연탄 원탄과는 달리 무연탄 분말이 바인더와 혼합되어 있으므로 매우 거친 상태를 나타내었고, 활성화시 거칠게 형성되어 있는 입자사이로 활성화제인 수증기가 쉽게 침투하여 많은 세공을 형성시킴을 알 수 있었다. 이렇게 형성된 세공을 통해 수증기 활성화반응이 잘 일어나 직경 3,000-50,000Å 범위의 거대세공이 발달하였다. 파쇄형 활성탄에 비해 약 2배의 거대세공(macropore)부피를 가지고 있었으며 경도도 30%에서 95% 이상으로 상승되었다. This study was to investigate the effect of granulation process on pore characteristics in manufacturing anthracitebased activated carbons. The activated carbons were made by three different methods to compare characteristics: the crushed activated carbon, the compressed activated carbon, and the extruded activated carbon. Among these activated carbons, the extruded activated carbon using a binder that consists of 25% coal tar and 7% water showed the best characteristics in specific surface area, pore volume, and hardness. Since the compressed and the extruded substances had coarser surfaces than a raw material, steam could penetrate easily through particles and produce macropores especially in the diameter ranges of 3,000-50,000Å during activation process. The extruded activated carbon showed about twice more macropore volumes than the crushed activated carbon and the hardness was increased from 30% up to 95%.
Design of ATM Networks with Multiple Traffic Classes
Ryu, Byung-Han,Cho, Cheol-Hye,Ahn, Jee-Hwan Electronics and Telecommunications Research Instit 1998 ETRI Journal Vol.20 No.2
In this paper, we propose a new heuristic design algorithm for the virtual path (VP)-based ATM network with multiple traffic classes, in which QoS constraints associated with traffic class are taken into account. The minimum bandwidth of VP required to carry given amount of traffic is obtained by utilizing an equivalent bandwidth concept, and the route of each VP is placed so that the network cost is minimized while the QoS requirement is fulfilled To evaluate our design algorithm, we consider two kinds of traffic: voice traffic as low speed service and still picture traffic as high speed service. Through numerical examples, we demonstrate that our design method can achieve an efficient use of network resources, which results in providing a cost-effective VP-based ATM network.
Ryu, Jae-Ha,Ryu, Shi-Yong,Han, Yong-Nam,Han, Byung-Hoon The Pharmaceutical Society of Korea 1997 Archives of Pharmacal Research Vol.20 No.1
A new celastraceae alkaloid, euojaponine C has been isolated from the methanol extract of the root bark of Euonymus japonica. With the relative stereochemistry of euojaponine C established by NOESY data, the absolute stereochemistry has been determined by circular dichroism (CD) exciton chirality method. The CD of the 2, 5-bis-phenyl benzoate of triacetonide derived from the LiAlH$_{4}$, hydrolysate, euonyminol shows that the configuration of C-2 and C-5 are both R.
Han, Byung Hoon,Han, Yong Nam,Ryu, Jae Ha,Moon, Chang Hyun,Lee, Soo Hwan 한국응용약물학회 1995 Biomolecules & Therapeutics(구 응용약물학회지) Vol.3 No.4
Crude ginseng saponin fraction reduced the production of thromboxane A₂ in the lipopolysaccharide-stimulated macrophages. Several kinds of crude saponins showed varient potency that might be caused by the compositional difference of ginseng saponins. From the metabolic labeling experimental data, this reduction of thromboxane A₂ formation, at least in part, resulted from the reduction of protein synthesis of inducible isozyme of cyclooxygenase(COX-2). This activity may be resulted from the fact that ginseng saponins have steroidal moiety in their structures.
Ryu Byung-Han,Hong Sun In,Lim Su Jin,Cho Younghwa,Hwang Cheolgu,Kang Hyungseok,Kim Si-Ho,Wi Yu Mi,Hong Kyung-Wook,Bae In-Gyu,Cho Oh-Hyun 대한의학회 2021 Journal of Korean medical science Vol.36 No.49
Background: Data on severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) delta variant virulence are insufficient. We retrospectively compared the clinical features of adult coronavirus disease 2019 (COVID-19) patients without risk factors for severe COVID-19 who entered residential treatment centers (RTCs) before and after the delta variant outbreak. Methods: We collected medical information from two RTCs in South Korea. On the basis of nationwide delta variant surveillance, we divided the patients into two groups: 1) the delta-minor group (diagnosed from December 2020–June 2021, detection rate < 10%) and 2) the delta-dominant group (diagnosed during August 2021, detection rate > 90%). After propensity-score matching, the incidences of pneumonia, hospital transfer and need for supplemental oxygen were compared between the groups. In addition, risk factors for hospital transfer were analysed. Results: A total of 1,915 patients were included. The incidence of pneumonia (14.6% vs. 9.2%, P = 0.009), all-cause hospital transfer (10.4% vs. 6.3%, P = 0.020) and COVID-19- related hospital transfer (7.5% vs. 4.8%, P = 0.081) were higher in the delta-dominant group than those in the delta-minor group. In the multivariate analysis, the delta-dominant group was an independent risk factor for all-cause (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.16–3.13; P = 0.011) and COVID-19-related hospital transfer (aOR, 1.86; 95% CI, 1.04–3.32; P = 0.036). Conclusion: Hospitalization rates were increased in the adult COVID-19 patients during the delta variant nationwide outbreak. Our results showed that the delta variant may be more virulent than previous lineages.