• 제목/요약/키워드: DES[2]

검색결과 545건 처리시간 0.025초

Performance of an acidic extractant (D2EHPA) incorporated in IM used for extraction and separation of Methylene Blue and Rhodamin B

  • Aitali, S.;Kebiche-Senhadji, O.;Benamor, M.
    • Membrane and Water Treatment
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    • 제7권6호
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    • pp.521-537
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    • 2016
  • Laboratory-scale experiments were carried out to investigate the adsorption equilibrium, the adsorption kinetics and facilitated transport of two cationic dyes (Methylene Blue (MB) and Rhodamine B (RB)) on Polymer Inclusion Membrane (D2EHPA-PIM). Different adsorption isotherms (Freundlich, Langmuir and Temkin models) as well as kinetics models indicated that the adsorption process is spontaneous and exothermic. Under the optimal conditions, the adsorption removal efficiencies reach about 93% and 97% for MB and RB respectively. Different extraction values by D2EHPA-PIM were obtained for the two cationic dyes: MB is weakly extracted at pH 2.0 (E% = 18.7%) whilst E% = 82.4% was observed for RB at the same pH. This difference was exploited in a mixture containg both the 2 cationic dyes for the selective extraction of RB at pH 2. Desorption of both dyes was achieved from the membrane by using acidic aqueous solutions and desorption ratio up to 90% was obtained. The formulas of the extracted complexes by the PIMs were, determined by the method of slopes. The dyes transport was elucidated using mass transfer analysis where in it found relatively high values of the initial flux ($J_0$) as 41.57 and $18.74{\mu}mol.m^2.s^{-1}$ for MB and RB respectively.

수증기 쪼임법에 의한 제올라이트형 보로실리케이트 제조방법 (Synthesis of Borosilicate Zeotypes by Steam-assisted Conversion Method)

  • Mansour, R.;Lafjah, M.;Djafri, F.;Bengueddach, A.
    • 대한화학회지
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    • 제51권2호
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    • pp.178-185
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    • 2007
  • 펜타실 구조와 유사한 제올라이트형 결정성 보로실리케이드를 수증기 쪼임법으로 제조하였다. 실제 여러 종류의 서로 다른 붕소화합물 원료를 사용하여 만든 다양한 조성의 Na2O.SiO2.B2O3.TBA2O 겔을 건조시켜 얻은 무정형 분말을 수열합성 분위기에서 수증기를 쪼임으로써 펜타실 구조를 갖는 보로실리케이트 제올라이트를 합성하였다. 이때 MFI와 MEL 구조가 90:10의 비율을 혼합되어 있는 새로운 중간구조 물질이 얻어 졌다. 본 연구로부터, 젖어 있는 반응성 고체상 물질이 수증기와 높은 pH 분위기에서 결정화가 이루어짐을 확인하였다. X-선 회절법으로 분석한 결과 생성물은 우수한 결정성을 가질뿐만 아니라 독특한 촉매적 성질을 보일것으로 예상되는 구조를 갖는다. 또한 반전중심을 갖는 MFI 구조의 펜타실 층이 규칙적으로 쌓이는 모양을 보이지만 이는 MEL 구조의 거울상 층으로 이루어진 결함에 의해 방해된다. 생성물은 77 K 질소흡착법에 의하면 미세기공 부피가 0.160 cc/g 로서 순수한 MFI 구조 물질이 갖는 0.119 cc/g 보다 더 크며, 비교적 넓은 비표면적(~600 m2/g)을 보인다. 적외선 스펙트럼에서는 900.75 cm-1에서 흡수띠를 보이는데, 이는 붕소가 결정성 실리케이트의 사면체 구조내에 위치함을 뜻한다.

Physiological Effects of Diethylstilbestrol Exposure on the Development of the Chicken Oviduct

  • Seo, Hee-Won;Park, Kyung-Je;Lee, Hyung-Chul;Kim, Dae-Yong;Song, Yong-Sang;Lim, Jeong-Mook;Song, Gwon-Hwa;Han, Jae-Yong
    • Journal of Animal Science and Technology
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    • 제51권6호
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    • pp.485-492
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    • 2009
  • Estrogen has dramatic effects on the development and function of the reproductive tract in mammals. Although diethylstilbestrol (DES) triggers the development of reproductive organs in immature animals, continued exposure to DES induces dysfunction of the female reproductive tract in mice. To investigate the effects of neonatal estrogen exposure on the reproductive tract of female chickens, we implanted DES pellets into the abdominal region of immature female chicks and then examined the effects of DES on the oviducts of both immature chicks and sexually mature chickens (30 weeks old). DES induced mass growth and differentiation of the oviduct in immature chicks. The chick oviduct increased by 2.7- and 29-fold in length and weight, respectively, following primary DES stimulation. In secondary DES stimulation, the length and weight of the chick oviduct increased by 4.5- and 74-fold, respectively. Additionally, DES treatments caused abnormal development of the infundibulum and magnum in hen oviducts. Furthermore, infundibulum abnormality gave rise to unusual ovulation of follicles and resulted in infertility and dysfunction of the magnum, such as less production of egg white proteins. Our results indicate that DES exposure during early developmental stages in chickens has detrimental effects on the development and maintenance of the female reproductive tract after sexual maturation.

선택적 중재합의조항의 유효성과 문제점 (Die wahlweise Vereinbarung zwischen Schieds- und Staatsgericht)

  • 정선주
    • 한국중재학회지:중재연구
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    • 제13권2호
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    • pp.585-612
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    • 2004
  • Die vorliegende Arbeit bezieht sich auf die Probleme, ob eine Vereinbarung, in der einer der Parteien oder den beiden ein Wahlrecht zwischen ordentlichem Gericht und Schiedsgericht eingeraumt ist, als eine wirksame Schiedsvereinbarung anzusehen ist, wem das Wahlrecht zuzustehen ist und wie das Wahlrecht auszuuben ist. Im Hinblick auf diese Problematik stehen nicht nur in der Literatur sondern auch in der Praxis die Meinungen einander kontrar gegenuber. Die Wirksamkeit einer wahlweisen Vereinbarung zwischen Schiedsund Staatsgericht ergibt sich vor allem aus dem Wesen der Schiedsgerichtsbarkeit, dem allgemeinen Personlichkeitsrecht i.V.m. Vertragsfreiheit und nicht zuletzt dem effektiven Rechtsschutz. Weil es fur das schiedsgerichtliche Verfahren wesentlich ist, dass es an die Stelle des sonst offenstehenden Verfahrens vor den Staatsgerichten tritt und nach dem Erlass des Schiedsspruchs die Beschreitung des ordentlichen Rechtswegs auszuschliessen ist, ist es erforderlich, den Parteien die Erledigung des Rechtsstreits auf verschiedene Weise zu gewahrleisten. Das tragt auch zum effektiven Rechtsschutz der Parteien bei. Ausserdem ist es nicht einzusehen, warum es rechtlich nicht moglich sein sollte, die Vertragsschliessenden sich gegenseitig das Wahlrecht zwischen Schiedsgericht und Staatsgericht einzuraumen. Die Vertragsfreiheit bzw. das allgemeine Personlichkeitsrecht gilt auch fur Schiedsvertrage. Wenn die Parteiautonomie im Privatrecht ihren Sinn behalten sollte, ist es notwendig, den Parteiwillen in dem wortlichen Ausdruck und in seinem Sinngehalt bestehen zu lassen. Damit steht fest, dass gegen die Einraumung eines Wahlrechts zwischen staatlichem Gericht und Schiedsgericht grundsatzlich keine Bedenken bestehen. Das Hauptproblem der wahlweisen Vereinbarung zwischen Schiedsund Staatsgericht liegt nicht in ihrer Wirksamkeit, vielmehr in den einzelnen Problemen hinsichtlich des Wahlrechts, namlich das Subjekt, die Art und Weise der Ausubung des Wahlrechts usw. Das Wahlrecht kann aufgrund der Parteivereinbarung nur einer Partei vorbehalten bleiben oder beiden eingeraumt werden. Anders als die Ansicht des hochsten Gerichtshofes ist von der Bindung der Partei an die Ausubung des Wahlrechts auszugehen, wenn die andere yon dem Wahlrecht Gebrauch macht. In bezug auf die Bindung bedarf es im Prinzip keiner erganzenden Vereinbarung, denn mit dem Verneinen dieser Bindung wurde zugleich das Wahlrecht selbst geleugnet. Ein Verbrauch des Wahlrechts ist anzunehmen, sobald die Klage vor dem staatlichen Gericht erhoben oder das Schiedsverfahren eingeleitet wurde. Steht das Wahlrecht nur einer Partei zu, ist es entsprechend §381 KBGB Frist zu setzen, nach deren fruchtlosem Ablauf das Wahlrecht ubergeht.

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Characterization of the Four GH12 Endoxylanases from the Plant Pathogen Fusarium graminearum

  • Habrylo, Olivier;Song, Xinghan;Forster, Anne;Jeltsch, Jean-Marc;Phalip, Vincent
    • Journal of Microbiology and Biotechnology
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    • 제22권8호
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    • pp.1118-1126
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    • 2012
  • Four putative GH12 genes were found in the Fusarium graminearum genome. The corresponding proteins were expressed in Escherichia coli, purified, and evaluated. FGSG_05851 and FGSG_11037 displayed high activities towards xyloglucan ($V_{max}$ of 4 and $11{\mu}mol/min$, respectively), whereas FGSG_07892 and FGSG_16349 were much less active with this substrate (0.081 and $0.004{\mu}mol/min$, respectively). However, all four of these enzymes had a similar binding affinity for xyloglucan. Xyloglucan was the substrate preferred by FGSG_05851, in contrast to the three other enzymes, which preferred ${\beta}$-glucan or lichenan. Therefore, FGSG_05851 is a xyloglucan-specific glucanase (E.C. 3.2.1.151) rather than an endoglucanase (E.C. 3.2.1.4) with broad substrate specificity. FGSG_11037 displayed a peculiar behavior in that the xyloglucan binding was highly cooperative, with a Hill coefficient of 2.5. Finally, FGSG_05851 essentially degraded xyloglucan into hepta-, octa-, and nonasaccharides, whereas the three other enzymes yielded hepta- and octa-saccharides as well as larger molecules.

Validation of a New Design of Tellurium Dioxide-Irradiated Target

  • Fllaoui, Aziz;Ghamad, Younes;Zoubir, Brahim;Ayaz, Zinel Abidine;Morabiti, Aissam El;Amayoud, Hafid;Chakir, El Mahjoub
    • Nuclear Engineering and Technology
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    • 제48권5호
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    • pp.1273-1279
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    • 2016
  • Production of iodine-131 by neutron activation of tellurium in tellurium dioxide ($TeO_2$) material requires a target that meets the safety requirements. In a radiopharmaceutical production unit, a new lid for a can was designed, which permits tight sealing of the target by using tungsten inert gaswelding. The leakage rate of all prepared targets was assessed using a helium mass spectrometer. The accepted leakage rate is ${\leq}10^{-4}mbr.L/s$, according to the approved safety report related to iodine-131 production in the TRIGA Mark II research reactor (TRIGA: Training, Research, Isotopes, General Atomics). To confirm the resistance of the new design to the irradiation conditions in the TRIGA Mark II research reactor's central thimble, a study of heat effect on the sealed targets for 7 hours in an oven was conducted and the leakage rates were evaluated. The results show that the tightness of the targets is ensured up to $600^{\circ}C$ with the appearance of deformations on lids beyond $450^{\circ}C$. The study of heat transfer through the target was conducted by adopting a one-dimensional approximation, under consideration of the three transfer modes-convection, conduction, and radiation. The quantities of heat generated by gamma and neutron heating were calculated by a validated computational model for the neutronic simulation of the TRIGA Mark II research reactor using the Monte Carlo N-Particle transport code. Using the heat transfer equations according to the three modes of heat transfer, the thermal study of I-131 production by irradiation of the target in the central thimble showed that the temperatures of materials do not exceed the corresponding melting points. To validate this new design, several targets have been irradiated in the central thimble according to a preplanned irradiation program, going from4 hours of irradiation at a power level of 0.5MWup to 35 hours (7 h/d for 5 days a week) at 1.5MW. The results showthat the irradiated targets are tight because no iodine-131 was released in the atmosphere of the reactor building and in the reactor cooling water of the primary circuit.

19세기 유우럽 신사복 Mode의 특성 (Tendenzen der Herrenmode im 19. Jahrhundert in Europa)

  • 양숙희
    • 한국의류학회지
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    • 제8권2호
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    • pp.27-40
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    • 1984
  • Die Geschichte des Kostums steht in unmittelbarem odor mittelbarem Zusammenhang mit der allgemeinea historischen Entwicklung derjenigen Lander und sozialen Schichten, die das kulturclle Gesicht und damit auch die Entwicklung der Mode einer Epoche bestimmen. Im 19. Jahrhundert war das Burgertum in Europa die herrschende soziale Schicht und daher auch modisch tonangebend. Die Mode des Burgertums zeigte demokratisierende Tendon-zen: Vereinfachung der Ausstattung und der Formen, wobei sich die Proportionen der Kleidung so gut wie moglich den des Korpers anpaBten. Die Herrenmode beugte sich zunehmend den For-derungen nach ZweckmaBigkeit; dab galt zumindest fur den Tagesanzug, der immer mehr zum Arbeitsanzug wurde und sick damit der Mannerkleidung der arbeinden Schicht annahrte. Die Industrialisierung trug ebenfalls dazu bei, daB die modischen und sozialen Previlegien in der Kleidung sich verminderten : die Textil-und Konfektionsindustrie muBte sich zwangs-laufig auf die Bedurfnisse der Massen und auf deren Wunsch einstellen. In der Herrenmode setzte sich die Tendenz zu funktionaler Einfachheit und Gradlinigkeit durch, d.h. funktional uberflussige Teile wie z.B. die Vielzahl der Kragen, Knopfreihen, uberlange SchoBe verschwanden ; an die Stelle der Farbenfreude trat ein einfaches, einhei-tliches Grau, Schwarz, Blau und Braun. Diese Vereinfachung wurde zum Ausdruck der zunehmenden Demokratisierung, wurde aber zugleich auch Voraussetzung fur eine neue Differnzierung des KlassenbewuBtseins. Zum Statussymbol wurden die auffalliges Erscheinen vermeidende Eleganz und das Arrangement der einzelnen Kleidungsstucke zu einem har-monischen Ganzen; elegante Kleidung weist ihren Trager aus als Kenner des Modetrends und damit als zugehorig zum Kreis der modeavancierten Schicht. Diese Ambivalenz bestimmt auch die Mode des 20. Jahrhunderts.

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Thermo-mechanical bending response with stretching effect of functionally graded sandwich plates using a novel shear deformation theory

  • Saidi, Hayat;Houari, Mohammed Sid Ahmed;Tounsi, Abdelouahed;Bedia, El Abbas Adda
    • Steel and Composite Structures
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    • 제15권2호
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    • pp.221-245
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    • 2013
  • This paper presents an analytical solution to the thermomechanical bending analysis of functionally graded sandwich plates by using a new hyperbolic shear deformation theory in which the stretching effect is included. The modulus of elasticity of plates is assumed to vary according to a power law distribution in terms of the volume fractions of the constituents. The core layer is still homogeneous and made of an isotropic ceramic material. The effects of functionally graded material (FGM) layer thickness, volume fraction index, layer thickness ratio, thickness ratio and aspect ratio on the deflections and stresses of functionally graded sandwich plates are investigated.

임베디드 환경에서의 H.235 기반 VoIP 보안 단말 구현 및 안전성 분석에 관한 연구 (An implementation and security analysis on H.235 for VoIP security on embedded environments)

  • 김덕우;홍기훈;이상학;정수환
    • 한국통신학회논문지
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    • 제29권7C호
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    • pp.1007-1014
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    • 2004
  • 본 논문에서는 ITU-T에서 제안한 VoIP 표준인 H.323 시스템의 보안 프로토콜인 H.235에 대하여 연구하고 이를 임베디드 환경의 IP Phone에 구현하여 VoIP 보안 프로토콜의 구현 요구사항 및 구현 결과에 따른 분석을 실시하였다. 특히 annex D에서 제안하고 있는 VoIP 단말에서의 보안 기능을 분석하여 구현하였는데, annex D에서는 HMAC-SHAI-96을 이용하여 인중과 무결성을 제공하고 Diffie-Hellman을 이용해서 음성 데이터 암호화에 사용되는 세션 키를 암호화해서 전달하며 음성 데이터의 암호화를 위한 RC2, DES, 3DES 등을 지원하고 있다. 또한 annex D의 안전성 및 상호 연동 문제점을 분석하여 취약점을 발견하고 보안을 강화하는 개선 방안을 제시하였다.

A Review on Recent Development and Applications of Dielectric Elastomers

  • Seo, Jin Sung;Kim, Dohyeon;Hwang, Sosan;Shim, Sang Eun
    • Elastomers and Composites
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    • 제56권2호
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    • pp.57-64
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    • 2021
  • This paper reviews recent developments and applications of dielectric elastomers (DEs) and suggests various techniques to improve DE properties. DEs as smart materials are a variety of electro-active polymers (EAPs) that convert electrical energy into mechanical energy and cause a large deformation when a voltage is applied. The dielectric constant, modulus, and dielectric loss of DEs determine the efficiency of deformation. Among these, the dielectric constant significantly affects their performance. Therefore, various recent approaches to improve the dielectric constant are reviewed, including the enhancement of polarization, introduction of microporous structures in the matrix, and introduction of ferroelectric fillers. Furthermore, the basic principles of DEs are examined, as well as their various applications such as actuators, generators, sensors, and artificial muscles.