• Title/Summary/Keyword: Separation Characteristics

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Gas Separation Properties of PTMSP-GO Composite Membrane (PTMSP-GO 복합막의 기체분리 특성)

  • Lee, Seul Ki;Hong, Se Ryeong
    • Membrane Journal
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    • v.28 no.2
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    • pp.105-112
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    • 2018
  • In this study, PTMSP-GO composite membranes were prepared by the addition of GO (graphene oxide) into PTMSP [poly (1-trimethylsilyl-1-propyne)] having high gas permeability, to study of gaseous membrane using GO. Gas permeation properties for $N_2$, $CH_4$, $CO_2$ were investigated by increasing the amount of GO in the PTMSP. PTMSP-GO composite membranes had higher gas permeability in the order of $N_2$ < $CH_4$ < $CO_2$. The gas permeation tendency of $N_2$, $CH_4$, and $CO_2$ increased as the content of GO increased from 0 to 10 wt%, but the gas permeability decreased as increased from 10 to 30 wt%. In the range of low GO contents, the gas permeability decreased due to the decrease of diffusivity because GO acts as a barrier in the composite membrane, and the gas permeability increased due to the void at the interface above the content range. And $CO_2$ has an affinity with -COOH of GO, the selectivity ($CO_2/N_2$) and the selectivity ($CO_2/CH_4$) gradually increase with increasing GO content. And the selectivity($CO_2/N_2$) showed the highest selectivity at 10.6 for PTMSP-GO 10 wt% and the selectivity ($CO_2/CH_4$) showed the highest selectivity at 3.4 for PTMSP-GO 20 wt%. However, above a certain amount of GO, selectivity ($CO_2/N_2$) and selectivity ($CO_2/CH_4$) decreased because the coagulation phenomenon between GO was increased and the solubility effect of $CO_2$ decreased. The PTMSP-GO 20 wt% composite membrane exhibited enhanced gas permeation characteristics with increased $CO_2$ permeability and selectivity ($CO_2/CH_4$) over PTMSP membrane.

An Improved Analytical Method for the Determination of Qualitative and Quantitative Characteristics of Di- and Trisaccharides in Honey using GC and GC/MS (GC 및 GC/MS에 의한 벌꿀 중의 이·삼당류 정성 및 정량 특성과 개선된 동시분석방법의 확립)

  • Kim, Jong-Bae;Jang, Eun-Suk;Kim, In-Suk;Lee, Hee-Jin;Lee, Hye-Jeong;Seo, Hyun-Sun;Park, Nam-Pyo
    • Korean Journal of Food Science and Technology
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    • v.47 no.1
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    • pp.27-36
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    • 2015
  • The improved analytical method with gas chromatography (GC) and GC-mass spectrometry was established to identify and quantify disaccharides and trisacchrides in honey. In this method, the analysis of trimethylsilyl (TMS), TMS-oxime and TMS-methoxime sugars takes into account the determination of a single peak of complete separation on the chromatogram. The number of possible peaks for the qualitative and quantitative determination of TMS, TMS-oxime, and TMS-methoxime sugars was 17, 22, and 25, respectively. This new analytical method allowed for the determination of diand trisaccharides in honey by TMS-oxime and TMS-methoxime derivatives. This study suggested that the improved method is more suitable and precise than the other analytical methods for the simultaneous determination of sugars in honey.

A Study on the Evolution of the Holding and Utilizing System of Fisheries Resources in Korea (수산자원 소유.이용제도의 변천에 관한 연구)

  • 류정곤
    • The Journal of Fisheries Business Administration
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    • v.22 no.1
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    • pp.1-52
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    • 1991
  • This study deals with the evolutional history of the holding and utilization of fisheries resources in Korea. Fisheries resources have the basic characteristics of the density dependent self-regulating renewable and common property resources, Irrational utilization of fisheries resources is mainly due to the unlimited access to the resources. The holding and utilization of fisheries resources in Koryo era was opened to everyone. But it was nationalized in the early Yi Dynasty. The purpose of its nationalization was to provent the paticular powered-man with their monoplized holding and to levy fisheries tax. Eoeop-peop, the first modern fisheries law in Korea, was enacted as a part of the invasion policy of Japan in 1908. With the japanese annexation of Korea in 1910, the Japanese Government established a new institutional system of fisheries as a part of an overall reformation of the institutional for an implementation of the colonial policy. It was very the new enacted Fisheries Law (Gyogyorei). Also the Government enacted compulsorily another new Fisheries Law (Chosen Gyogyorei) with its adjunct laws and regulations revise the institutional system of fisheries on May 1, 1930. After Eoeop-peop enactment, the fisheries resources in Korea could be used only under the license, permission, and statement. After Korea was from Japan in 1945, Korea Government at last enacted the new fisheries law (Susaneop-peop) in 1953. The goal of Susaneop-peop was to achive the general usage and protection of the fisheries resources, and to attain the development and democratization of the fishery in Korea. This law was amended 13 times until 1990. The license fishery have a legal right on the fishery, called a fishery rigt. This right means a right of exclusive occupation and utilization of a unit of the inshore fishing grounds. The main evolutional issues of license fishery are as the following : 1) the foundation of the exclusive usable fishery right(1911, Gyogyorei), 2) the deletion of the settled U9space lift net and settled space sein net fishery, and the expansion of the cooperative fishery-No.1, 2, and 3 type cooperative fishery-(3rd amendment, 1963), 3) the deletion of the No.2 and 3 type cooperative fishery, and the separation of the culturing fishery in No.1 and 2 type culturing fishery (13th amendment, 1990). The effective period of the license fishery was amended as the following : 1) 1908(Eoeop-peop) : within 10 years, renovation system, 2) 1929(Chosen Gyogyorei) : within 10 years, unlimited extension system, 3) 1971. 7th amendment : 10 years, renovation system, 4) 1972. 8th amendment : 10 years, only 1 extension system, 5) 1975. 9th amendment : 5-10 years, only 1 extension system, 6) 1990.13th amendment : 10 years, within 10 years of total extensional years. The priority order of the fishery license was established in 1953 (Susaneop-peop). The amendment of it is as follows : 1) 1953. enactment \circled1 the fishing grounds that the fishery right is extablished 1st order : the existing fishery right man, unlimited renovation 2nd order : the corporate that the regional fisherfolk organized 3rd order : the rest experienced fishermen \circled2 new fishing grounds 1st order : the corporate that the regional fisherfolk organized 2nd order : the rest experienced fishermen 2) 1971. 9th amendment \circled1 the fishing grounds that the fishery right is established 1st order : the existing fishery right man, unlimited renovation 2nd order : the Eochongye that the regional fisherfolk organized 3rd order : the regional fishery cooperative that the regional fisherfolk organized 4th order : the rest experienced fishermen \circled2 new fishing grounds 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd order : the rest experienced fishermen 3) 1981. 10th amendment \circled1 the inside of No.1 type cooperative fishing grounds 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd orer : the rest experienced fishermen 4) 1990. 13th amendment \circled1 No.1 type cultural fishery 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd order : the rest experienced fishermen \circled2 No.2 type cultural and settle fisher : general priority order The effective period of the permission fishery was amended 6 timed. First, it was within 5 years and renovation system (Eoeop-peop). Now it is 5 years and renovation system. The effective period of the statement fishery was amended 4 times. First, it was within 5 years, and then was amended within 3 years(Chonsen Gyogyorei). Now it is 5 years.

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The geography of external control in Korean manufacturing industry (한국제조업에서의 외부통제에 관한 공간적 분석)

  • ;Beck, Yeong-Ki
    • Journal of the Korean Geographical Society
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    • v.30 no.2
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    • pp.146-168
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    • 1995
  • problems involved in defining and identifying it. However, data on ownership of business establishments may be useful and one of the best alternatives for this empirical research because of use of limited information about control This study examines the spatial patterns of external control in the Korean manufacturing activities between 1986 and 1992. Using the data on ownership iinkages of multilocational firms between 15 administrative areas, it was possible to construct a matrix of organizational control in terms of the number of establishments. The control matrix was disaggregated by three types of manufacturing industries according to the capital and labor requirements of production processes used in. On the basis of the disaggregated control matrix, a series of measures were calculated for investigating the magnitude and direction of control as well as the external dependency. In the past decades Korean industrialization development has risen at a rapid pace, deepening integration into the world economy, together with the continuing growth of the large industrial firms. The expanded scale of large firms led to a spatial separation of production from control, Increasing branch plants in the nation. But recent important changes have occurred in the spatial organization of production by technological development, increasing international competition, and changing local labor markets. These changes have forced firms to reorganize their production structures, resulting in changes of the organizational structures in certain industries and regions. In this context the empirical analysis revealed the following principal trends. In general term, the geography of corporate control in Korea is marked by a twofold pattern of concentration and dispersion. The dominance of Seoul as a major command and control center has been evident over the period, though its overall share of allexternally controlled establishments has decreased from 88% to 79%. And the substantial amount of external control from Seoul has concentrated to the Kyongki and Southeast regions which are well-developed industrial areas. But Seoul's corporate ownership links tend to streteh across the country to the less-developed regions, most of which have shown a significant increase of external dependency during the period 1986-1992. At the same time, a geographic dispersion of corporate control is taking place as Kyongki province and Pusan are developing as new increasingly important command and control reaions. Though these two resions contain a number of branch plants controlled from other locations, they may be increasingly attractive as a headquarters location with increasing locally owned establishments. The geographical patterns of external control observable in each of three types of manufacturing industries were examined in order to distinguish the changing spatial structures of organizational control with respect to the characteristics of the production processes. Labor intensive manufacturing with unskilled iabor experienced the strongest external pressure from foreign competition and a lack of low cost labor. The high pressure expected not only to disinte-grate the production process but also led to location of production facilities in areas of cheap labor. The linkages of control between Seoul and the less-developed regions have slightly increased, while the external dependency of the industrialized regions might be reduced from the tendency of organizational disintegration. Capita1 intensive manufacturing operates under high entry and exit barriers due to capital intensity. The need to increase scale economies ied to an even stronger economic and spatial oncentration of control. The strong geographical oncentration of control might be influenced by orporate and organizational scale economies rather than by locational advantages. Other sectors experience with respect to branch plants of multilocational firms. The policy implications of the increase of external dependency in less-developed regions may be negative because of the very share of unskilled workers and lack of autonomy in decision making. The strong growth of the national economy and a scarcity of labor in core areas have been important factors in this regional decentralization of industries to less-developed regions. But the rather gloomy prospects of the economic growth in the near future could prevent the further industrialization of less-developed areas. A major rethinking of regional policy would have to take place towards a need for a regional policy actively favoring indigenous establishments.

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Study of Polysulfone Membrane for Membrane-covered Oxygen Probe System (산소 전극 시스템에 사용되는 polysulfone막에 대한 연구)

  • Hong, Suk In;Kim, Hyun Joon;Park, Hee Young;Kim, Tae Jin;Jeong, Yong Seob
    • Applied Chemistry for Engineering
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    • v.7 no.5
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    • pp.877-887
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    • 1996
  • The ideal membranes for membrane-covered oxygen probes system should be selectively permeable for oxygen and chemically inert, and have good mechanical strength. Polysulfone(PSf) was selected to develop the membrane for membrane-covered oxygen electrodes system. PSf membranes have properties such as good reproducibility, good mechanical strength, chemical inertness, and high heat resistance. PSf membranes were cast from polymer solution on the glass plate at constant temperature, and casting solvents used were tetrahydrofuran(THF), methylene chloride, and N-methyl-2-pyrrolidone(NMP). Tricresyl phosphate(TCP) as plasicizer was added to PSf to increase the softness of membrane. The permeation characteristics were observed for pure oxygen and nitrogen through pure PSf membranes by variable volume method and membrane-covered electrode system. The permeability coefficients of oxygen and nitrogen measured by variable volume method were slightly decreased with increasing of upstream pressure. The permeation properties of PSf membrane using methylene choride as casting solvent were not affected by the PSf amount of polymer solution. The permeability coefficients of oxygen and nitrogen for PSf membrane containing TCP were very slightly lower than those for pure PSf membrane, but ideal separation factors were slightly higher. The flexibility of PSf membrane containing 2wt% TCP was better than that of pure PSf membrane. It was expected that this increase in flexibility would solve the difficulty of fixing the membrane to the cathode. The membrane-covered oxygen probes system was composed of anode, cathode and electrolyte. The type of the anode was Ag/AgCl half-cell, that of cathode was Ag, and the electrolyte was 4N KCl solution. The result of sampled current voltametry for PSf membrane showed the plateu region at -0.3V~-1.0V. The correlation coefficient of oxygen partial pressure versus current for PSf membrane was relatively high, 0.99949. It was concluded that PSf membrane was the good candidate for the membrane-covered oxygen probes system.

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Simultaneous Separation and Determination of $^{l4}C\;and\;^3H$ in Spent Resins from PWR Nuclear Power Plants (가압경수로형 원전에서 발생된 폐수지의 $^{14}C$$^3H$ 동시 분리 및 측정)

  • Park, Soon-Dal;Kim, Jung-Suck;Kim, Jong-Goo;Han, Sun-Ho;Jee, Kwang-Yong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.3
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    • pp.179-188
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    • 2007
  • In this work $^{14}C\;and\;^3H$ distribution characteristics of spent resins from nuclear power plants(NPPs), pressurized water reactors(PWRs), was investigated. It was found that the recovery percent of $^{14}C$ by the wet oxidation-acid stripping was $81%{\sim}100%$ for the added activity range of $^{14}C,\;0.72\;Bq{\sim}460\;Bq$, and it was not affected by the kinds of stripping acids, 3N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$. And the recovery percent of $^3H$ by distillation using the same apparatus was $81%{\sim}101%$ for the added activity range of $^3H,\;0.60\;Bq{\sim}435\;Bq$. Among the tested stripping acids, 3\;N-HCl, $3\;N-HNO_3\;and\;3\;N-H_2SO_4$, only the trapped $^3H$ solution by distillation in $3\;N-H_2SO_4$ was compatible with the 3H scintillator, Ultimagold XR. Neither of the $^{14}C\;and\;^3H$ trapping solutions from the spent ion exchange resin samples by the wet oxidation-3 $N-H_2SO_4$ stripping contained gamma nuclides. However, some gamma nuclides, $^{60}Co,\;^{134}Cs,\;^{137}Cs\;and\;^{54}Mn$, were found in the trapped $^3H$ solutions of the spent resins by the wet oxidation-3 N-HCl stripping. It was the same for the $^3H$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). Meanwhile only two nuclides, $^{134}Cs,\;and\;^{134}Cs$, were found in the $^{14}C$ trapping solutions of the spent resins by Sample Oxidizer(PACKARD MODEL 307). It was found that most of the $^{14}C$ in the spent resins existed as inorganic carbon form, more than about 70% of the total $^{14}C$ content. Among the analyzed 30 spent ion exchange resin samples, the average concentration of $^{14}C$ and $^3C$ for the high radioactive samples, 8 samples, was $19000\;Bq/g{\pm}41000\;Bq/g,\;670\;Bq/g{\pm}460\;Bq/g$ and that for the low radioactive samples, 22 samples, was $4.2\;Bq/g{\pm}4.3\;Bq/g,\;6.0\;Bq/g{\pm}5.3\;Bq/g$, respectively. And the average $^{14}C/^3H$ ratio for the high radioactive samples, was higher, 28, than that of low radioactive samples, 0.70. Some linear relationship trend was found between the activity concentrations of $^{14}C\;and\;^3H$.

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Genetic Variation and Polymorphism in Rainbow Trout, Oncorhynchus mykiss Analysed by Amplified Fragment Length Polymorphism

  • Yoon, Jong-Man;Yoo, Jae-Young;Park, Jae-Il
    • Journal of Aquaculture
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    • v.17 no.1
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    • pp.69-80
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    • 2004
  • The objective of the present study was to analyze genetic distances, variation and characteristics of individuals in rainbow trout, Oncorhynchus mykis using amplified fragment length polymorphism (AFLP) method as molecular genetic technique, to detect AFLP band patterns as genetic markers, and to compare the efficiency of agarosegel electrophoresis (AGE) and polyacrylamide gel electrophoresis (PAGE), respectively. Using 9 primer combinations, a total of 141 AFLP bands were produced, 108 bands (82.4%) of which were polymorphic in AGE. In PAGE, a total of 288 bands were detected, and 220 bands (76.4%) were polymorphic. The AFLP fingerprints of AGE were different from those of PAGE. Separation of the fragments with low molecular weight and genetic polymorphisms revealed a distinct pattern in the two gel systems. In the present study, the average bandsharing values of the individuals between two populations apart from the geographic sites in Kangwon-do ranged from 0.084 to 0.738 of AGE and PAGE. The bandsharing values between individuals No.9 and No. 10 showed the highest level within population, whereas the bandsharing values between individuals No.5 and No.7 showed the lowest level. As calculated by bandsharing analysis, an average of genetic difference (mean$\pm$SD) of individuals was approximately 0.590$\pm$0.125 in this population. In AGE, the single linkage dendrogram resulted from two primers (M11+H11 and M13+H11), indicating six genetic groupings composed of group 1 (No.9 and 10), group 2 (No. 1, 4, 5, 7, 10, 11, 16 and 17), group 3 (No. 2, 3, 6, 8, 12, 15 and 16), group 4 (No.9, 14 and 17), group 5 (No. 13, 19, 20 and 21) and group 6 (No. 23). In AGE, the genetic distances among individuals of between-population ranged from 0.108 to 0.392. In AGE, the shortest genetic distance (0.108) displaying significant molecular differences was between individuals No.9 and No. 10. Especially, the genetic distance between individuals No. 23 and the remnants among individuals within population was highest (0.392). Additionally, in the cluster analysis using the PAGE data, the single linkage dendrogram resulted from two primers (M12+H13 and M11+H13), indicating seven genetic groupings composed of group 1 (No. 15), group 2 (No. 14), group 3 (No. 11 and 12), group 4 (No.5, 6, 7, 8, 10 and 13), group 5 (No.1, 2, 3 and 4), group 6 (No.9) and group 7 (No. 16). By comparison with the individuals in PAGE, genetic distance between No. 10 and No. 7 showed the shortest value (0.071), also between No. 16 and No. 14 showed the highest value (0.242). As with the PAGE analysis, genetic differences were certainly apparent with 13 of 16 individuals showing greater than 80% AFLP-based similarity to their closest neighbor. The three individuals (No. 14, No. 15 and No. 16) of rainbow trout between two populations apart from the geographic sites in Kangwon-do formed distinct genetic distances as compared with other individuals. These results indicated that AFLP markers of this fish could be used as genetic information such as species identification, genetic relationship or analysis of genome structure, and selection aids for genetic improvement of economically important traits in fish species.

Blend Characteristics of PBT, Nylon6,12 and Preparation of PBT/Nylon6,12 Micro Fiber with Core/shell Structure and their Extrusion Conditions (PBT와 Nylon6,12의 블렌드 특성과 core/shell 구조를 갖는 PBT/Nylon6,12 미세모의 제조 및 압출조건)

  • Park, Hui-Man;Lee, Seon-Ho;Kwak, Noh-Seok;Hwang, Chi Won;Park, Sung-Gyu;Hwang, Taek Sung
    • Korean Chemical Engineering Research
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    • v.50 no.6
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    • pp.1068-1075
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    • 2012
  • Poly(butylene terephthalate) (PBT)/Nylon6,12 core/shell micro fiber were prepared by extrusion molding. To investigate their optimum extrusion conditions, compatibility of PBT/Nylon6,12 blend micro fiber in conformity to their weight ratio and manufacture temperature was explored with SEM morphology and DSC. The alterations in their mechanical properties by extrusion speed were compared and analyzed through a UTM. In comparison with SEM figures, the domain sizes of Nylon6,12 were gradually declined by increasing the extrusion temperature of blends. Furthermore, according to these SEM images, the phase separation between Nylon6,12 domain and PBT matrix became indistinct with increasing of weight percentage of Nylon6,12. In case of DSC, the boundaries of two peaks were almost disappeared when increasing the extrusion temperature and also intervals of each two melting peaks became narrow as increasing the Nylon6,12 ratio. The mechanical properties including tensile strength, elongation, flexural strength and flexural modulus were increased as the increase in the extrusion temperature until $260^{\circ}C$. However, the mechanical properties were actually deteriorated over $260^{\circ}C$. The tensile strength, elongation, flexural strength and flexural modulus at $260^{\circ}C$ were 560 $kg_f/cm^2$, 220%, 807 $kg_f/cm^2$ and 22,146 $kg_f/cm^2$, respectively. These values are more than intermediate values of mechanical properties of PBT and Nylon6,12. These results mean that there is compatibility between PBT and Nylon6,12. Based on the extrusion conditions that produced optimum compatibility of blend, as a result, our group obtained micro fibers with the core/shell structure.

Writing and Sijo in new media culture age (새로운 매체문화시대의 글쓰기와 시조)

  • Jung Ki-chul
    • Sijohaknonchong
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    • v.22
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    • pp.27-55
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    • 2005
  • Visual media are taken the highest position in modem society, Modern poems also have been changed into visual poems, This aspect is the result of considering only individual talents ignoring traditions. Now, new Sigo should be concentrated on the mythological and historical voice from true nature and the body of human being, That is. ut should be converted into an ecological world view resolutely and restored a form of expression granted specific characteristics of our language. Advantages the computer media have brought. that is. equality freedom. human rights. harmony. pro-environmental value. can be maximized by positively accepting an ecological world view of Sijo which had included daily lives and spirits of the nation. Moreover. these all changes of new Sijo have to be established and recreated in the traditional expressions of Sijo. Aesthetic value of Sijo should be found in the expression forms such as phonetic harmony, rules of versification, rhythm, and etc. Then, we can overcome modern society's pathological phenomena such as severance, separation, dissolution, estrangement, psychiatric syndrome and etc. which visual media superiority brought. At the same time. it will cure ills of modern poems, Sijo and writing epochally and can establish true happiness and development.

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Agronomic Characteristics of A Mutant for Genic Male Sterility-Chalky Endosperm and Its Utilization on $F_1$ Hybrid Breeding System in Rice (벼 유전자적 웅성불임-심백 돌연변이체의 특성과 그를 이용한 일대잡종 육성체계)

  • ;Mun-Hue Heu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.6
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    • pp.684-696
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    • 1995
  • A mutant for chalky endosperm and genetic male sterility (GMS) was newly developed in rice. The two characters were found to be controlled by single recessive gene which has pleiotropic effect, indicating that chalky seeds should be GMS seeds in segregating populations. Chalky seeds showed the same shape and size as normal seeds. However, starch composition of central part of endosperm was looser and shape of starch granules was rounder compared with normal endosperm, resulting in significantly lower grain weight, absolute density and grain hardness in chalky grains than in normal ones. Amylose content and gel consistency of chalky grains were much lower and harder, respectively. Male sterile plants showed much shorter plant height, poorer panicle exsertion and lesser panicle number compared with normal plants. Microspore abortion stage in pollen developmental process was observed as before meiosis. Male sterility of the mutant was stable regadless of temperature and day length. A system breeding hybrid rice using this mutant was discussed, comp ring with other systems utilizing cytoplasmic-genic male sterility(CGMS) and environment sensitive GMS(EGMS). Separation of GMS seeds in mixed seed bulks by specific gravity (1.14∼1.16g / cm3) was successful about 85∼90%. But some mixed normal plants were seemed to be easily removed by the apparent difference in growth characters at seedling stage. The highest natural outcrossing rate of this GMS line was as 17.3 % in a plot treated with 2-row pollinator, I-row GMS, and GA3 + cutting of flag leaf + pollen-scattering by rope.

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