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A Study on the Electrical and Optical Characteristics of CLN-PZT Ceramics (CLN-PZT 세라믹스의 전기, 광학 특성에 관한 연구)

  • Kang, Won-Koo
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.799-801
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    • 1988
  • This paper was studied on the effects of Ca-La-Nb substitution and Zr/Ti ratio variation to Pb(Zr, Ti)$O_3$ system on structural, electrical, optical and sound level characteristics in order to develope the piezoelectric and electrooptic ceramic devices. Also the specimens were prepared by the two stage sintering technique. The molecular formular was X($CaO{\cdot}1/4La_{2}O_{3}{\cdot}1/4Nb_{2}O_{5}){\cdot}(1-X)Pb(Zr_{Y}Ti_{1-Y})O_{3}$(x=100X, y=100Y), and the variation of x was $6{\sim}12$, y was 60${\sim}$49 and second stage sintering time was 20${\sim}$40 hours. The experimental results obtained from this study are as follows : 1. The density was decreased, the grain size was increased according to increase of Ca-La-Nb substitution. 2. The crystal structure was rhombohedral in composition 6/60/40, and the crystal structure was tetragonal and cubic according to increase of Ca-La-Nb substitution. 3. The Ca substitution of PZT system enhanced the sintering property. The Pb site vacancy resulting from the substitution of La-Nb increased the dielectrical constant, the piezoelectric charge constant, the dielectric loss and decreased the coercive field. 4. The resistivity of PZT system which has the P type conduction mechanism increased according to substitution of La-Nb because of the substituent acting as donor. 5. The PZT ceramics varied from ferroelectric substance according to increase of Ca-La-Nb substituent. The coercive field and saturation remanent polarization decreased, and at last straight line according to increase of La-Nb substitution. 6. The amount of Ca-La-Nb substitution to improve the light transmittance of speciment was 10 mol%, the Zr/Ti ratio was 49/51, and the second stage sintering time was 40 hours. 7. According to Ca-La-Nb substitution, the specimens was to be transparent. The 7.5/51/49 specimen was suitable for transparent sound vibrator because it had 58% light transmittance (thick 0.2[mm], wave length 700[mm]) and 48% electromechanical coupling factor.

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A Comparative Study on Low-Carbon Port Management of Busan and LA/LB - On the Basis of Port Management Cost - (LA/LB항과 부산항의 저탄소 항만운영에 관한 비교연구 - 비용부담을 중심으로 -)

  • Cho, Dong-Oh
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.2
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    • pp.223-228
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    • 2010
  • In the midst of worldwide response to climate change, the advanced ports including LA/LB(Los Angeles/Long Beach) has started to reduce carbon emission from port area which has not been targets of interests in the worldwide cooperation. Recently, the Port of Busan has started to reduce carbon emission from the port area under the Green Port Strategy in Korea. However, the low-carbon port management increases the cost of port management and negatively impacts the port competitiveness in the short term. Therefore, the Busan Port Authority is carrying out the low-carbon projects directly and has not transfer the cost to the port users, such as shipowers, cargo owners and terminal operators. However, the Port Authority of LA/LB has transferred the cost at low-carbon port management to customers of port. In this study, comparative analysis on cost of low-carbon port management at Busan and LA/LB is carried out for sustainable port management.

Quality Characteristics of Squid Sikhae by Preparation Method and Fermentation Conditions (오징어 식해의 제조 방법에 따른 품질 특성)

  • Lee Ye-Kyung;Park Bum-Do;Kim Soon-Dong
    • Journal of the East Asian Society of Dietary Life
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    • v.15 no.4
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    • pp.405-412
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    • 2005
  • Quality characteristics of squid-sikhae prepared by four different methods(SHM: sikhae method, SHM-LA; sikhae method added with L plantarum, MM; mixed method of sikhae method and salting method, MM-LA; MM method added with L plantarum) were investigated during fermentation at $20^{\circ}C$. The pHs of all the 6-days fermented sikhae samples were in the range of 4.01-3.76, meaning that there were no significant difference in pH according to the preparation methods. Number of total microbes(TM) were decreased, while the ratio of lactic acid bacteria against TM in SHM-LA and MM-LA was higher than those of SHM and MM. There were no differences in acid protease activity, while $NH_2-N$ content of SHM and MM were higher than those of SHM-LA and MM-LA. Amylase activity was the lowest in MM-LA. Proteins separated by SDS-PAGE belonged to 7-200 kDa, the major proteins (153<94<41 kDa) of the sikhae in all plots were disappeared at 6 days fermentation. In sensory evaluation, sour taste of MM was the highest, while it was the lowest in SHM-LA. Sweet taste, bitter taste, salty taste and hot taste were not significantly different Off-flavor was decreased in lactic acid bacteria added products. Scores of the softness and overall acceptability were the highest in SHM-LA. These results indicated that SHM-LA was the best method for the preparation of squid sikhae because of the enhancement of lactic acid fermentation and overall acceptability.

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Rhizoma Rehmanniae induced Apoptosis in Human Cervical Carcinoma HeLa Cells (생지황(生地黃)이 자궁경부암세포(子宮經部癌細胞)(HeLa cell)에 미치는 영향(影響))

  • Kim, Joo-Yeon;Jo, Ok-Hyon;Choe, Chang-Min;Cho, Han-Baek
    • The Journal of Korean Obstetrics and Gynecology
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    • v.19 no.1
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    • pp.69-80
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    • 2006
  • Purpose : This study is to evaluate the synergistic cytotoxicity of Rhizoma Rehmanniae(RR), in adriamycin-treated HeLa human cervical carcinoma cells. Methods : We culture HeLa cell which is human metrocarcinoma cell in D-MEM included 10% fetal bovine serum(Hyclone Laboratories) below $37^{\circ}C$, 5% $CO_2$. Then we observed apoptosis of log phage cell which is changed cultivation liquid 24 Hours periodically. Results : The combination of RR and adriamycin synergistically augmented the cytotoxicity of HeLa cells. The apoptotic cell death was accompanied by the activation of caspase-3 and -8 as well as cleavage of poly(ADP- ribose) polymerase (PARP) in HeLa cells. The co-treatment of RR with adriamycin didn't have any effect on either the expression of Bcl-2 or that of Bax. Interestingly, a synergistic increase in apoptosis by the combination of two drugs was accompanied by the enhancement of Pas and Fas ligand (FasL) expression in HeLa cells. Taken together, the combination of RR and adriamycin significantly augmented the apoptotic cytotoxicity of Fas-positive cells, such as HeLa cells. The pathway is not involved in mitochondria-dependent pathway. Conclusion : RR induces apoptosis in HeLa cells via p38 MAPK activation.

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An IS-41 Based dynamic Location Management using the Mobility History of Mobile Station (이동국의 이동이력을 이용한 IS-41 기반 동적위치관리)

  • Lee, Tae-Ro;Han, Chi-Geun;Jo, Dong-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.4
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    • pp.1032-1044
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    • 1999
  • In the mobile communication systems such as PCS(Personal Communication Service), several strategies have been proposed to optimize the signalling traffic load by using the characteristics of traffic and mobile patterns for effective mobility management. According to IS-41 standard, LA(Location Area) consists of static and arbitrarily-defined set of cells, which do not take into account mobility patterns of mobile stations. In this paper, we propose an improved location management mechanism which contains the neighbor cells of the LA selectively using the mobility history of a mobile station and accommodates the LA size adaptively according to the speed of the mobile station. Also, we use the paging priorities for cells in LA to improve the paging efficiency. We compare the performance of conventional mechanism with that of the proposed mechanism using numerical analysis. The analysis results show that the proposed location management mechanism is better than conventional mechanism significantly.

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Charge Structure of the Combined System (La0.6Sr0.4MnO3)0.7(La0.6Sr0.4FeO3)0.3 as Investigated by Mössbauer Spectroscopy

  • Uhm, Young Rang;Kim, Sam Jin;Kim, Chul Sung
    • Journal of Magnetics
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    • v.7 no.1
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    • pp.18-20
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    • 2002
  • The charge structures of (LSMO) and of the combined system $(La_{ 0.6}Sr_{0.4}FeO_3$(LSMO) and of the combined system (La_{0.6}Sr_{0.4}MnO_3)_{0.7}(La_{0.6}Sr_{0.4}/FeO_3)_{0.3}$are investigated by using M$\ddot{o}$ssbauer spectroscopy. The antiferromagnetically ordered $(La_{0.6}Sr_{0.4}FeO_3$(LSFO) has possible charges of Fe^{3+} and Fe^{4+}$, which include a low-spin $Fe^{4+}$ state at and above 230 K. The temperature dependences of the M$\ddot{o}$ssbauer spectra for the $(La_{ 0.6}Sr_{0.4}FeO_3$ system and for the combined $(LSMO)_{ 0.7}(LSFO)_{0.3}$ system are fitted as three sets of Zeeman patterns corresponding to $Fe^{3+}$ and $Fe^{4+} below 230 K. At and above 230 K, the fitted M$\ddot{o}$ssbauer spectra for the combined system are the same in all temperature ranges. Above 230 K, $(La_{0.6}Sr_{0.4}FeO_3$ spectrum consists of two sets of six Lorentzians for $Fe^{3+}$ and one line for low spin $Fe^{4+}$. It is worth noting that large fields are induced in the combined system.

Growth Inhibitory Effect and Changes in Membrane Phospholipid Fatty Acid Composition on MG-63 and AZ-521 Human Cancer Cells by Linoleic Acid (리놀레산에 의한 인체암세포의 성장 억제효과 및 암세포막 인지질 지방산 변화)

  • 임선영;이숙희;이세윤;박건영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.4
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    • pp.662-668
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    • 1997
  • Linoleic acid(LA) was examined to evaluate its potential as a chemotherapeutic agent for MG-63 human osteosarcoma and AZ-521 gastric cancer cells. The treatment of LA(0.005% for 6 days) to the MG-63 and AZ-521 cancer cells inhibited growth of the cancer cells by 54% and 52%, respectively as compared to that of the controls. It also exhibited that LA with 0.01% concentration decreased the [$^3$H] thymidine incorporation by more than 90% in the both cancer cells. In additions we observed morphological changes in MG-63 and AZ-521 cells under inverted microscope, and the changes in membrane fatty acid compositions of the cancer cells when LA was added at the level of 0.005%. The treatment with LA revealed that the contents of 16:0 and 18:0 decreased significantly, but fatty acids that C numbers are more than 20 and unsaturated(20:4, 22:6, and 24:4) increased, concomitantly the morphological changes of the cells were observed.

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Ionesco et Roumanie (이오네스코와 루마니아)

  • PARK, hyung-sub
    • Cross-Cultural Studies
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    • v.26
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    • pp.95-121
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    • 2012
  • Ce travail est de rechercher la vie litteraire d'Eug?ne Ionesco ? l'?poque de la Roumanie(1921~1937). Ionesco fait partie d'une cat?gorie d'?crivains(Mircea Eliade, Emil Cioran, Tristan Tzara, Pana?t Istrati, etc) qui sont n?s en Roumanie et ont commenc? leur carri?re dans leur pays d'origine pour la continuer et l'achever en France. Eugen Ionescu devient Eug?ne Ionesco. Ce dernier repr?sente d?j? dans les ann?es 30 une personnalit? hors du commun. C'est un homme qui a deux patries, deux racines : une roumaine, une autre fran?aise. Sa vie est a ?t? marqu?e par ses publications des l'adolescence. Ils font l'objet de ce livre-portrait d'Eugen Ionescu, po?te et critique, ?crivain de langue roumaine. L'?tude de la jeunesse roumaine d'Ionesco nous m?ne sur un terrain p?rilleux, celui de la biographie, plus pr?cis?ment des ann?es d'adolescence, de jeunesse et d'apprentissage d'un ?crivain qui a masqu? cette p?riode de sa vie. Nous avons pr?fer? tracer une biographie intellectuelle plutot qu'?num?rer des d?tails anecdotiques. La projection d'Ionesco dans son oeuvre est le r?cit de ses propres aventures intellectuelles. Une part importante de notre travail est consacr?e ? l'anlayse d'un livre de critique Nu(Non) de jeune Ionesco. Nous avons utilis? le texte de la version fran?aise publi?e en 1986 pour ce travail. Pour Ionescu le Roumain, le po?te Ionesco, ?l?gies pour des ?tres minuscules, nous avons consult? une th?se d'Ecaterina Cleynen-Serghieve La jeunesse litt?raire d'Eug?ne Ionesco et puis l'?tude de Gelu Ionesco sur la carri?re roumaine d'Ionesco. Nous nous sommes aussi r?f?r?s ? divers documents comme Notes et contre-notes(1966), D?couvertes(1969), Journal en miettes et Pr?sent pass?, Pass? pr?sent(Mercure de France), et les entretiens avec Claude Bonnefoy pour comprendre la personnalit? d'un jeune ?crivain roumain.

Multilocus sequence type-dependent activity of human and animal cathelicidins against community-, hospital-, and livestock-associated methicillin-resistant Staphylococcus aureus isolates

  • Sun Do, Kim;Geun-Bae, Kim;Gi Yong, Lee;Soo-Jin, Yang
    • Journal of Animal Science and Technology
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    • v.64 no.3
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    • pp.515-530
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    • 2022
  • Sequence type (ST) 5 methicillin-resistant Staphylococcus aureus (MRSA) with staphylococcal cassette chromosome mec (SCCmec) type II (ST5-MRSA-II) and ST72-MRSA-IV represent the most significant genotypes for healthcare- (HA) and community-associated (CA) MRSA in Korea, respectively. In addition to the human-type MRSA strains, the prevalence of livestock-associated (LA) MRSA clonal lineages, such as ST541 and ST398 LA-MRSA-V in pigs and ST692 LA-MRSA-V and ST188 LA-MRSA-IV in chickens, has recently been found. In this study, clonotype-specific resistance profiles to cathelicidins derived from humans (LL-37), pigs (PMAP-36), and chickens (CATH-2) were examined using six different ST groups of MRSA strains: ST5 HA-MRSA-II, ST72 CA-MRSA-IV, ST398 LA-MRSA-V, ST541 LA-MRSA-V, ST188 LA-MRSA-IV, and ST692 LA-MRSA-V. Phenotypic characteristics often involved in cathelicidin resistance, such as net surface positive charge, carotenoid production, and hydrogen peroxide susceptibility were also determined in the MRSA strains. Human- and animal-type MRSA strains exhibited clonotype-specific resistance profiles to LL-37, PMAP-36, or CATH-2, indicating the potential role of cathelicidin resistance in the adaptation and colonization of human and animal hosts. The ST5 HA-MRSA isolates showed enhanced resistance to all three cathelicidins and hydrogen peroxide than ST72 CA-MRSA isolates by implementing increased surface positive charge and carotenoid production. In contrast, LA-MRSA strains employed mechanisms independent of surface charge regulation and carotenoid production for cathelicidin resistance. These results suggest that human- and livestock-derived MRSA strains use different strategies to counteract the bactericidal action of cathelicidins during the colonization of their respective host species.

L'idea dell'umanità nuova nelle tragedie Saul e Mirra di Alfieri (알피에리의 비극 『사울Saul』과 『미라Mirra』에 나타난 새로운 인간의 이상)

  • Jang, Ji Yeon
    • Lettere Italiane
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    • no.36
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    • pp.125-150
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    • 2012
  • Vittorio Alfieri fu celebrato dagli uomini del Risorgimento come "l'iniziatore ed il padre della rinascita" e il creatore della coscienza nazionale. Per questo è lodato da Foscolo, Manzoni, Leopardi, Mazzini, Gioberti, Oriani, Carducci. Ma insieme con i suoi meriti politici, anche i valori artistici delle sue opere non debbono essere dimenticati. Anche sul pensiero e sull'opera dell'Alfieri influirono le ideologie tipiche del secondo Settecento, l'Illuminismo e il nascente Romanticismo, in lui intrecciandosi e scontrandosi ad un tempo. Il suo interesse per lo studio dell'uomo, per la concezione meccanicistica del mondo, la lontananza dalla religione per l'assoluta libertà e l'avversione verso il dispotismo, collegano Alfieri alla dottrina illuminista. I temi letterari illuministici, volti a chiarificare le coscienze e ad apportare il progresso sociale e civile, sono affrontati dal poeta non in modo distaccato, ma con l'emotività e le inquietudini del pensiero romantico. Ma i letterati romantici dell'Ottocento furono piuttosto ostili all'opera dell'Alfieri, accusandola di astratezza, di lontananza dagli interessi e dalla realtà della vita moderna e di assenza di senso storico. Invece nei primi anni del Novecento, Croce lo presenta come iniziatore della nuova letteratura italiana, con la quale egli avrebbe in comune l'individualismo, la passionalità, l'amore per la solitudine, la malinconia. Anche se gli manca l'ansia religiosa sul fine e il valore della vita e l'interessamento per la storia, ecc., secondo il Croce si può definire un protoromantico. Nelle sue opere ci sono, sotto l'aspetto dell'Illuminismo l'odio istintivo contro la tirannide e l'amore per la libertà, e sotto quello protoromantico esplode l'urto violento di sentimenti e passioni e l'esaltazione della morte eroica dei protagonisti. E anche Saul e Mirra descrivono l'idea dell'umanità eroica che muore dopo una lunga vicenda di miseria e di abbiezione. L'idea dell'umanità nuova in Saul e Mirra è l'idea degli uomini nuovi che egli desiderava.