• 제목/요약/키워드: Pseudo center

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Synthesis and Reactivity of a Mononuclear Manganese(II) Complex Having Pseudo-Seven Coordination Environment

  • Yoon, Jee-Hee;Seo, Mi-Sook;Kim, Young-Mee;Kim, Sung-Jin;Yoon, Sung-Ho;Jang, Ho G.;Nam, Won-Woo
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.679-682
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    • 2009
  • Utilizing a planar five coordinating N3S2 ligand, 2,6-bis(2-methylthiophenyliminomethyl)pyridine, a pseudo 7-coordinated manganese(II) complex with two labile triflate anions in the axial positions was synthesized. The reaction of the manganese(II) complex with an oxidant, iodosylbenzene, produced a metastable high-valent manganese(IV)-oxo species at 0 ${^{\circ}C}$. The high-valent Mn(IV)-oxo intermediate was characterized with a UV-vis spectrophotometer and an electrospray ionization mass spectroscopy. Reactivity studies of the Mn(IV)=O species revealed that the intermediate is capable of oxygenating $PPh_3$ and N-dealkylating N,N-dimethyl-toludine.

Hydrocortisonee 의 $\Delta^1$-Dehydrogenation 에서 소포제의 영향 (Effect of Antifoam Agents on $\Delta^1$-Dehydrogenation of Hydrocortisone)

  • Chung, Bong-Hyun;Son, Jung-Duk;Park, Young-Hoon
    • 한국미생물·생명공학회지
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    • 제17권3호
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    • pp.219-223
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    • 1989
  • Hydrocortisone의 $\Delta$$^1$-Dehydrogenation에 의한 prednisolone의 생산에서 소포제인 silicone oil과 neolin 302의 영향이 조사되었다. 미생물 전환방법은 pseudo-crystallofermentation 기법에 의해 수행되었다. 스테로이드 입자들은 소포제와의 hydrophobic-hydrophobic interaction에 의해 서로 응집되었다. 이러한 응집 현상에 의해 고체 기질의 용해속도와 비례하는 물질전달 면적이 감소됨으로써, 결국 생물전환속도의 감소를 유발하게 된다. Neolin은 silicone oil에 비해 전환속도에 더욱 좋지 않은 영향을 끼쳤으며, 소포제 농도가 증가할수록 전환속도는 감소하였다.

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Equilibrium and kinetic studies for the removal of cationic dye using banana pith

  • El-Maghraby, Azza;Taha, Nahla A.
    • Advances in environmental research
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    • 제3권3호
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    • pp.217-230
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    • 2014
  • The large quantity of green cull bananas has the potential of being used industrially and, thereby, to improve banana economics and eliminate the large environmental problem presented by banana waste. Wastewaters from textile, cosmetics, printing, dying, food colouring, and paper-making industries are polluted by dyes. The adsorption of basic dye by waste banana pith was investigated by varying dye concentrations, adsorbent dose, particle size and agitation rate. The adsorption capacity was found to be maximum value of removal by using 0.1 g of sorbent with particle size 1mm at mixing speed 200 rpm for initial concentration 25 mg/l to reach value of approximate 89%. The Langmuir, Temkin and Freundlich adsorption models were used for mathematical description of the adsorption equilibrium and it was found that experimental data fitted very well to these models except Langmuir model. Adsorption of dye was applied on (pseudo-first and pseudo-second-order kinetics), and the experimental data was more fitted to pseudo second order. The results of this study showed that banana pith could be employed as effective and low-cost materials for the removal of dyes from aqueous solutions.

Adsorption of Phenol on Mesoporous Carbon CMK-3: Effect of Textural Properties

  • Haque, Enamul;Khan, Nazmul Abedin;Talapaneni, Siddulu Naidu;Vinu, Ajayan;JeGal, Jong-Geon;Jhung, Sung-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제31권6호
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    • pp.1638-1642
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    • 2010
  • Mesoporous carbon CMK-3s with different textural properties have been used for the adsorption of phenol to understand the necessary physicochemical properties of carbon for the efficient removal of phenol from contaminated water. The kinetic constants (both pseudo-second order and pseudo-first-order kinetics) increase with increasing pore size of carbons. The maximum adsorption capacities correlate well with micropore volume compared with surface area or total pore volume even though large pore (meso or macropore) may contribute partly to the adsorption. The pore occupancies also explain the importance of micropore for the phenol adsorption. For efficient removal of phenol, carbon adsorbents should have large micropore volume and wide pore size for high uptake and rapid adsorption, respectively.

준역행렬과 투영행렬을 이용한 구속 다물체계의 동역학 해석 (A dynamic analysis for constrained multibody systems using pseudo-inverse and projection matrix)

  • 김외조;유완석
    • 대한기계학회논문집A
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    • 제22권1호
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    • pp.170-176
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    • 1998
  • In this paper, the column space and null space of the Jacobian matrix were obtained by using the pseudo-inverse method and projection matrix. The equations of motion of the system were replaced by independent acceleration components using the null space matrix. The proposed method has the following advantages. (1) It is simple to derive the null space. (2) The efficiency is improved by getting rid of constrained force terms. (3) Neither null space updating nor coordinate partitioning method is required. The suggested algorithm is applied to a three-dimensional vehicle model to show the efficiency.

복소 유사응력함수에 의한 타원 강체함유물을 내포하는 크립재료의 응력해석 (Stress analysis of creep material containing elliptical rigid inclusion by complex pseudo-stress function)

  • 이강용;김종성
    • 대한기계학회논문집A
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    • 제22권2호
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    • pp.408-415
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    • 1998
  • The analysis model is the power law creep material containing an elliptical rigid inclusion subjected to the arbitrarily directional stress on infinite boudary. The stress analysis is performed using the conformal mapping function and complex pseudo-stress function. The stress distributions near an elliptical rigid inclusion are obtained with various ellipse shapes, strain hardening exponents and directions of applied stress.

Primary Myopathic Chronic Intestinal Pseudo-Obstruction in a Maltese Dog

  • Jung, Joohyun;Choi, Mincheol
    • 한국임상수의학회지
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    • 제33권3호
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    • pp.179-182
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    • 2016
  • An 11-year-old castrated male Maltese had vomiting, diarrhea, and abdominal distension for over two weeks and weight loss for several months. Clinical laboratory studies were not remarkable. Abdominal radiographs showed severe dilated intestine with a gravel sign. Colon was empty with normal diameter in the pneumocolon study. On ultrasonographs, most small bowel loops were dilated without normal peristalsis and showed abnormal thin wall. Barium contrast study revealed remarkably delayed gastric emptying and transit time up to $6^{th}$ day. On exploratory laparotomy, there were no mechanical obstruction and extra-intestinal abnormalities except severe dilated small intestine. Chronic fibrosing lymphohistiocytic leiomyositis with atrophy of tunica muscularis in the small intestines and colon was identified through full thickness biopsy and histopathology. Therefore, primary myopathic chronic intestinal pseudo-obstruction was diagnosed. This dog is survival with symptomatic treatments for eight months.

Feasibility study on model-based damage detection in shear frames using pseudo modal strain energy

  • Dehcheshmeh, M. Mohamadi;Hosseinzadeh, A. Zare;Amiri, G. Ghodrati
    • Smart Structures and Systems
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    • 제25권1호
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    • pp.47-56
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    • 2020
  • This paper proposes a model-based approach for structural damage identification and quantification. Using pseudo modal strain energy and mode shape vectors, a damage-sensitive objective function is introduced which is suitable for damage estimation and quantification in shear frames. Whale optimization algorithm (WOA) is used to solve the problem and report the optimal solution as damage detection results. To illustrate the capability of the proposed method, a numerical example of a shear frame under different damage patterns is studied in both ideal and noisy cases. Furthermore, the performance of the WOA is compared with particle swarm optimization algorithm, as one the widely-used optimization techniques. The applicability of the method is also experimentally investigated by studying a six-story shear frame tested on a shake table. Based on the obtained results, the proposed method is able to assess the health of the shear building structures with high level of accuracy.

The Rapid Differentiation of Toxic Alexandrium and Pseudo-nitzschia Species Using Fluorescent Lectin Probes

  • Cho, Eun-Seob;Park, Jong-Gyu;Kim, Hak-Gyoon;Kim, Chang-Hoon;Rhodes, Lesley L.;Chung, Chang-Soo
    • Journal of the korean society of oceanography
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    • 제34권3호
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    • pp.167-171
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    • 1999
  • Since toxic Alexandrium catenella and non-toxic A. fraterculus are morphologically similar, they are difficult to discriminate under the light microscope. However, a novel technology, such as fluorescein isothiocyanate (FITC)-conjugated lectin probes enables easy and rapid differentiation. Toxic A. catenella bound seven different lectins, whereas the non-toxic A. fratercuzus did not bind Arachis hypogaea (PNA) lectin. In addition, Pseudo-nitrschia species in this study were also difficult to identify to species level with light microscope techniques, but it was possible to classify them using fluorescent lectins. Pseudo-nitzschia multistriata, P. subfraudulenta and P. pungens bound Canavalia ensiformis (ConA), whereas P. subpaclfica did not, and P. pungens also bound Ricinus communis (RCA). These results imply that lectin could be used as a critical tool in the differentiation of P. multistriata, P. subfraudulenta and P. pungens. However, P. subpacifica was not differentiated by the lectins tested. Therefore, it isconcluded that lectin probes are useful for discriminating toxic A. catenella from non-toxic A. fraterculus, and for the identification of some Pseudo-nitzschia species. In addition, this method has a great potential to speed and detection between non-toxic and toxic harmful algal blooms (HABs) in Korean biotoxin monitoring systems.

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수화한 무정형 알루미나로부터 제조된 $\gamma$-Alumina의 특성 (Characteristics of $\gamma$-Alumina Prepared from Rehydrated Amorphous Alumina)

  • 김윤섭;고형신;서정권;이정민;하백현
    • 한국재료학회지
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    • 제11권11호
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    • pp.978-985
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    • 2001
  • The amorphous alumina was obtained by flash calcination of Bayer gibbsite[$Al(OH)_3$aluminum trihydroxide]. Rehydration and pore characteristics of $r-A1_2O_3$ prepared from rehydrated amorphous alumina were investigated. Crystal phases of pseudo-boehmite and bayerite were changed when amorphous alumina was hydrated at various conditions such as time, the ratio of water/alumina and pH. Specific surface areas and pore volumes of $r- A1_{2O}_3$ were influenced by the reaction time, water/alumina and PH of rehydration. The total pore volume of $r-A1_{2O}_3$increases with increasing the reaction time and ratio of water/alumina. Especially, the pure pseudo-boehmite of single phase could be prepared, when amorphous alumina was hydrated in the range of pH 6.5-8.0 in water/alumina= 10 at $90^{\circ}C$ for 7hr. The $r-Al_{2O}_3$, obtained by calcination of the prepared pseudo-boehmite at $500^{\circ}C$ for 2hrs, is characterized by the specific surface area of $265m^2$/g, total pore volume of $0.75cm^3$/g.

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