• Title/Summary/Keyword: limiting factors

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Effects of Growth Regulator for Promoting Lateral Shooting in White-Spine Cucumber(Cucumis sativus L.) (백침계 모이 측지발생 촉진을 위한 생장조정제 이용 효과)

  • Lee Jae Han;Kwon Joon Kook;Kang Nam Jun;Jung Ho Jung;Park Jin Myeon;Kang Kyung Hee;Choi Young Hah
    • Journal of Bio-Environment Control
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    • v.14 no.4
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    • pp.275-279
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    • 2005
  • The fruiting habit pattern of white-spine cucumber, whose fruits are usually borne on the lateral branches, is different from domestic ones. The cucumber production far export has been focused on how to promote lateral shooting and how to increase the number of lateral branches. As the growing season of the exporting cucumber is confined to winter season, low temperature and weak light are limiting factors to lateral shooting. This study was conducted to investigate the effect of foliar application of growth regulator for induction of lateral shoot in white-spine cucumber. foliar application of growth regulator were focused on concentration and application time based on number of leaves. The visible damages were observed in applied leaves by $30mg{\cdot}L^{-1}$ BA(benzyladenine) in retarding culture, but no significant by $10mg{\cdot}L^{-1}$ BA in case of semi-forcing culture. The number of available lateral shoots were greater in applied plant with $10mg{\cdot}L^{-1}$ BA than that of $30mg{\cdot}L^{-1}$ BA, in applied plants at 10th and 15th loaves than that of applied plants at 5th leaves.

Analyses of Inter-cultivar Variation for Salinity Tolerance in Six Korean Rapeseed Cultivars

  • Lee, Yong-Hwa;Lee, Tae-Sung;Kim, Kwang-Soo;Jang, Young-Seok;Nam, Sang-Sik;Park, Kwang-Geun
    • Horticultural Science & Technology
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    • v.30 no.4
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    • pp.417-425
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    • 2012
  • Salinity stress is one of the most serious factors limiting the productivity of agricultural crops. The aim of this study was to assess inter-cultivar (intraspecific) variation for salinity tolerance in six Korean rapeseed (Brassica napus L.) cultivars at the seedling stage. The effect of three different salinity stress levels (EC 4, 8, and 16 $dS{\cdot}m^{-1}$) on seedlings of six cultivars was investigated through leaf size, leaf dry weight, and leaf chlorosis. At the highest salinity level (16 $dS{\cdot}m^{-1}$), the mean decrease of leaf dry weight in 'Sunmang', 'Tammi', 'Tamla', 'Naehan', 'Youngsan', and 'Halla' was about 56.2, 56.9, 78.4, 79.3, 77.4, and 80.9%, respectively. 'Tammi' and 'Sunmang' showed much less reduction in leaf dry weight than all the other cultivars. In addition, diluted seawater treatments increased the occurrence of leaf chlorosis in six cultivars. At EC 8 and 16 $dS{\cdot}m^{-1}$, 'Naehan', 'Youngsan', and 'Halla' showed a higher level of leaf chlorosis than 'Tammi' 'Sunmang', and 'Tamla'. On the basis of these results, six cultivars were placed into salinity-tolerant and sensitive groups. 'Tammi' and 'Sunmang' were the salinity-tolerant cultivars, while 'Naehan', 'Halla', 'Youngsan', and 'Tamla' were the salinity-sensitive cultivars. 'Tammi' and 'Naehan' rated as the most tolerant and most sensitive cultivar, respectively. To further analyze protein expression profiles in 'Tammi' and 'Naehan', 2-D proteomic analysis was performed using the plants grown under diluted seawater treatments. We identified eight differentially displayed proteins that participate in photosynthesis, carbon assimilation, starch and sucrose metabolism, amino acid metabolism, cold and oxidative stress, and calcium signaling. The differential protein expressions in 'Tammi' and 'Naehan' are likely to correlate with the differential growth responses of both cultivars to salinity stress. These data suggest that 'Tammi' is better adapted to salinity stressed environments than 'Naehan'.

Current Research Status of Postharvest and Packaging Technology of Oriental Melon (Cucumis melo var. makuwa) in Korea (국내 참외의 수확 후 관리 및 포장기술 연구)

  • Kim, Jung-Soo;Choi, Hong-Ryul;Chung, Dae-Sung;Lee, Youn-Suk
    • Horticultural Science & Technology
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    • v.28 no.5
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    • pp.902-911
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    • 2010
  • Oriental melon ($Cucumis$ $melo$ var. $makuwa$) is a popular and high-value market fruit cultivated in Korea. Consumers are becoming increasingly interested in oriental melon as a healthy diet over the past few years. However, the melons have relatively high quality loss because the fruit are mainly produced for a limited period of time in the summer season. Lack of the proper postharvest treatments and high temperature exposure at harvest or during distribution are the most critical environmental factors limiting postharvest life of fruit. This review focuses on the overview of current research studies for postharvest treatment and functional packaging technology of oriental melon in Korea. Major physiological problems of the harvest fruit include the ripening process in quality changes of the produce such as loss of weight, firmness, flavor, and decay during the storage periods. Low temperature at 7 to $10^{\circ}C$ with high relative humidity of 90 to 95% is the suitable environmental condition used to maintain the quality of fresh oriental melon. Controlled atmosphere (CA) storage or modified atmosphere (MA) packaging can be used as supplemental treatments to extend postharvest-life. For oriental melon, an optimum CA is currently recommended to be 2-3% oxygen and 5-10% carbon dioxide atmosphere. Precooling, pretreatments of ethylene action and functional packaging system can be applied to oriental melon after harvest in order to extend storage life. Major active packaging technologies are concerned with a selectively gas permeable film related to respiration of produce and the packaging applications of ethylene removal, antimicrobial, and antifogging substances to keep the effective freshness of fruit.

Effects of Fouling on Permeate Flux during Ultrafiltration of Protein Solutions in a Hollow-Fiber Membrane Reactor (중공사 막반응기에서 단백질용액의 한외여과시 유출속도에 미치는 Fouling의 영향)

  • 김세권;변희국이환근하진환
    • KSBB Journal
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    • v.9 no.5
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    • pp.483-491
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    • 1994
  • It is known that a key limiting factor to the use of ultrafiltration membranes is that of membrane fouling, which has been a major cause of permeate flux reduction. In this work, the effects of several factors (operating time, protein concentration, temperature and pH, etc.) influencing permeate flux during ultrafiltration of gelatin, casein and bovine serum albumin using a hollow fiber membrane(M. W. 10,000 cut off) reactor have been examined. The permeate flux of gelatin solution was maintained almost constant during the operation up to 6 hours, but those of casein and albumin solutions were decreased to 50% and 43% of initial value after an operation time of 60min. The permeate flux with increasing concentration and temperature of protein solutions increased, but the permeate flux showed a minimum value near the isoelectric point of proteins. The permeate fluxes of protein solution were enhanced by a temperature increase and pH control. Also, it is proposed that fouling can be decreased by the pretreatment of insoluble proteins with enzymes.

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Pre-treatment Technology of Wastewater Sludge for Enhanced Biogas Production in Anaerobic Digestion (혐기소화에서의 바이오가스 생산 증진을 위한 슬러지 전처리 기술)

  • Kim, Dong-Jin
    • Clean Technology
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    • v.19 no.4
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    • pp.355-369
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    • 2013
  • Economic feasibility is one of the most important factors in energy production from regenerative biomass. From the aspect, biogas from anaerobic digestion of wastewater sludge is regarded as the most economical because of its cheap substrate and additional income from the disposal of waste sludge. Sludge hydrolysis has been regarded as the rate limiting step of anaerobic digestion and many sludge pre-treatment technologies have been developed to accelerate anaerobic sludge digestion for enhanced biogas production. Various sludge pre-treatment technologies including biological, thermo hydrolysis, ultrasonic, and mechanical methods have been applied to full-scale systems. Sludge pre-treatment increased the efficiency of anaerobic digestion by enhancing hydrolysis, reducing residual soilds, and increasing biogas production. This paper introduces the characteristics of various sludge pre-treatment technologies and the energy balance and economic feasibility of each technology were compared to prepare a guideline for the selection of feasible pre-treatment technology. It was estimated that thermophilic digestion and thermal hydrolysis were most economical technology followed by Cell rupture$^{TM}$, OpenCEL$^{TM}$, MicroSludge$^{TM}$, and ultrasound. The cost for waste sludge disposal shares the biggest portion in the economic analysis, therefore, water content of the waste sludge was the most important factor to be controlled.

Utilization of Various Electron Acceptors in Shewanella putrefaciens DK-l (Shewanella putrefaciens DK-1의 Fe(III) 환원 특성)

  • 조아영;이일규;전은형;안태영
    • Korean Journal of Microbiology
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    • v.39 no.3
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    • pp.175-180
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    • 2003
  • Microbial Fe(III) reduction is an important factor for biogeochemical cycle in anaerobic environments, especially sediment of freshwater such as lakes, ponds and rivers. In addition, the Fe(III) reduction serves as a model for potential mechanisms for the oxidation of organic compounds and the reduction of toxic heavy metals, such as chrome or uranium. Shewanella putrefaciens DK-1 was a gram-negative, facultative anaerobic Fe(III) reducer and used ferric ion as a terminal electron acceptor for the oxidation of organic compounds to $CO_{2}$ or other oxidized metabolites. The ability of reducing activity and utilization of various electron acceptors and donors for S. putrefaciens DK-1 were investigated. S. putrefaciens DK-1 was capable of using a wide variety of electron acceptor, including $NO_{3}^{-}$, Fe(III), AQDS, and Mn(IV). However, its ability to utilize electron donors was limited. Lactate and formate were used as electron donors but acetate and toluene were not used. Fe(III) reduction of S. putrefaciens DK-l was inhibited by the presence of either $NO_{3}^{-}$ or $NO_{2}^{-}$. Further S. putrefaciens DK-1 used humic acid as an electron acceptor and humic acid was re-oxidized by nitrate. Environmental samples showing the Fe(III)-reducing activity were used to investigate effects of the limiting factors such as carbon, nitrogen and phosphorus on the Fe(III) reducing bacteria. The highest Fe (III) reducing activity was measured, when lactate as a carbon source and S. putrefaciens DK-1 as an Fe(III) reducer added in untreated sediment samples of Cheon-ho and Dae-ho reservoirs.

The Expansion Strategy for the New Route between Korea and Hungary (한-헝가리 간의 신물류 확대전략)

  • Seo, Dae-Sung
    • Journal of Distribution Science
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    • v.12 no.6
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    • pp.59-65
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    • 2014
  • Purpose - The competitiveness of logistics in the 21st century rests on ensuring the efficiency and effectiveness of its local hub. While considering entry into a niche market in local logistics, it is pertinent to note that Budapest is emerging as a hub in EU enlargement in Eastern Europe. Big, small, and medium-sized businesses in Korea entered Hungary in the early 1990s since then, there has been a significant increase in Korean presence, of approximately 130 times. This study aimed to identify the key distribution issues that have emerged in relation to Eastern Europe. Research design, data, and methodology - This study indicates that 33 major Korean companies were located in Hungary, which serves as an out post to enter the European marketplace. However, Korea's exports to Hungary have declined (-32.0% in 2012) because of a loss of competitiveness against multinational corporations, due to factors such as the rise in current local distribution costs and wages. Hungary, on the other hand, through diversification and expansion of foreign trade with the non-EU markets, including Korea, is increasing its exports. Strategies of emerging countries are compared and reviewed in this study, by examining the vicissitudes of Hungary's distribution methods. Results - There are issues regarding Hungary's innovative ability. Hungary has a history of low wages and high skilled labor. However, the outflow of high-quality human resources for high-wages has become more extensive, and this underlines concerns that the CEE's trade hub is moving to neighboring countries. After the European financial crisis in 2010, the Hungarian economy is now developing, because of the IMF's measures, and it is being transformed into a trade surplus nation, while regaining distribution volumes rapidly. However, if there is continued lack of investment, the supply chain is weakened and exports decline amidst competition with TNCs or with China's distribution networks. Conclusions - It is necessary to create a new logistics approach for increasing trade between Korea and Hungary. First, Korean small and medium enterprises (SMEs) should build trust by working with advanced Hungarian talent, and they should expand into state-of-the-art fields instead of being confined to traditional sectors. Second, this study focuses on limiting and lowering their high expectations for success according to foreign direct investment (FDI) inflows and the role in the CEE distribution hub Korea should try to strengthen the distribution hub with its centralized population, using better, more highly educated human resources, thereby sustaining more innovative ability. Further, the positive effects of these measures are manifested in enhanced business on both sides of Hungary, namely, the EU and non-EU nations such as Turkey and emerging markets around Europe, and a better engagement in the core placement of culture and industry. For this, Korea can contribute to, and benefit from, a Hungarian logistics center, for adopting the high-tech cluster systems and commercializing distribution technology such as RFID·USN.

DISTRIBUTION CHARACTERISTICS OF NUTRIENTS IN CHINESE BOHAI SEA

  • Li, Zhengyan;Gao, Huiwang;Bai, Jie;Shi, Jinhui
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2001.11a
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    • pp.19-29
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    • 2001
  • Nutrients are key environmental factors in marine ecosystem. They limit algal growth when at low concentrations and cause algal bloom when at high contents. They also control the growth and succession of many other biota including bacteria and zooplankton, either directly or indirectly. Nutrient contents therefore affect both the structure and functions of marine ecosystem. To study the contents and distribution of nutrients in Chinese Bohai Sea, two cruise surveys were undertaken in August 2000 (summer) and January 2001 (winter), respectively. A total of 595 water samples were collected from 91 sites. After collection the samples were transported to the laboratory and five nutrients, i.e., nitrate, nitrite, ammonia, phosphate and silicate, were analyzed. The results showed that tile average concentration of total inorganic nitrogen (TIN) in Bohai Sea in winter (6.5293.717 ${\mu}$mol$.$l$\^$-1/) was significantly higher than that in summer (3.717 ${\mu}$mol$.$l$\^$-1/). The phosphorus concentration in winter (0.660 ${\mu}$mol$.$l$\^$-1/) was also significantly higher than that in summer (0.329 ${\mu}$mol$.$l$\^$-1/). Mean silicate concentration in winter (7.858 ${\mu}$mol$.$l$\^$-1/) was not significantly different from that in summer (7.200 ${\mu}$mol$.$l$\^$-1/). Nutrients also varied considerable among different areas within Bohai Sea. TIN concentration in Laizhou Bay (4.444 ${\mu}$mol$.$l$\^$-1/), for example, was significantly higher than those in Bohai Bay (2.270 ${\mu}$mol$.$l$\^$-1/) and Bohai Straight (2.431 ${\mu}$mol$.$l$\^$-1/), which probably reflects tile discharge of large amounts of nitrogen into Laizhou Bay via Yellow River. The nutrients also showed vertical distribution pattern. In summer, nutrients in bottom layer were generally higher than those in surface and medium layers. In winter, however. nutrients in different layers were not significantly different Compared with historic data, TIN contents increased continuously since early 1980s, phosphorus arid silicone contents, nevertheless, fell down to some degree. Based on atomic ratios of different nutrients, nitrogen is still the main limiting factor for algal growth in Bohai Sea.

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A Study on the Concept of Mental Health in Korea (한국인의 정신건강 개념에 관한 연구)

  • Kim, Dong-Bae;Ahn, In-Kyung
    • Korean Journal of Social Welfare
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    • v.56 no.1
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    • pp.203-233
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    • 2004
  • Rapid process of industrialization and modernization in Korea has caused earning differentials between the rich and the poor, the feeling of alienation followed by excessive competitions among the members of community as well as the conflict between generations. Because of those factors, Koreans have come to undergo several mental problems such as anxiety, melancholy and suicide. However, scarce concern or effort has been given to solve those mental problems in the professional field of mental health. Social work service for mental health in Korea has been delivered on the basis of the Law of Mental Health, most of which are focused on treatment or care of mental patient himself or his family. Therefore ordinary people who have no mental disorder but have desire for mental health have no way to take service in the field of public mental health except for counselling programs given by some of the private social welfare institutions. In this context, the process of clarifying the concept of mental health is demanded before we develop the mental health program. As social welfare is the practical science that helps people seek after happiness and meaningful life, so clarifying the concept of mental health is needed not only for the field of mental health itself but also for every field of social welfare. In order to achieve this purpose, this study firstly arranged concepts of mental health in Korea using Q methodology. As the result, we found 21 dimensions including spiritual one and self-wellbeing one which newly identified in this study as well as 19 dimensions of Jahoda. We also found Koreans perceive concepts of mental health as independently as 5 types of Communalist, Rationalist, Individualist, Humanist, and Religionist. Secondly, on the basis of the result, we suggested that mental health programs in social welfare should be oriented to the positive concept of mental health. This study could furnish fundamental data that enable the concept of mental health to be spread to that of the growth for a better life not limiting on that of the prevention or the treatment of the mental disorder.

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A study of the Characteristics of Community Design for Modern Industrial Heritage's Reproduction (근대산업유산 재생을 위한 커뮤니티디자인 특성 연구)

  • Jeong, Min-Joo;Lee, Chan
    • Korean Institute of Interior Design Journal
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    • v.23 no.4
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    • pp.157-168
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    • 2014
  • In buildings on the street, indiscriminate redevelopment are being made by overlooking the relationship with surrounding landscape to create their own unique meaning, due to industrialization progressed rapidly with human needs of longing for something constantly. Selection and methods of two plans, conservation and utilization should be required, considering heritage values on industrial buildings which are being lost and aged in this redevelopment higher. The attempt for the use of modern industrial heritage becomes a hot topic, and several experimental challenges are being made. However, there are rather many cases of causing industrial buildings' depreciation and one-size-fits-all reproduction performance as it applies other examples as standards by recognizing the reproduction of modern industrial heritage as one trend, not focusing on the trend of the times or paradigm, what the times want. To minimize these problems, we focus on how to utilize industrial buildings beyond the importance of industrial buildings' reproduction, considering the quality of local residents' life as well as the expected effect obtainable due to security of local identity and reproduction of buildings, focusing on the concept of community design that offers and forms a way of community life as the design of shares based on unspecified individuals' common life. Community design's core can be called to have diversity rather than undifferentiated unity by pursuing whole unification, since local residents become those who plan design and all people participate in it. In addition, community design achieves integration with other fields as an enlarged design area without limiting in an environmental area, by making indigenously natural characteristics combined with cultural factors in one context so that people may understand the flow of the place. The importance of effects acquired from modern industrial heritage's reproduction has well-known, and the attempt for utilizing aged heritage as a new value and a function has constantly been made. Now, it's time to focus on how long it lasts through this method, rather than modern industrial heritage's reproduction itself. There can be a significance in this study in proposing methodological solutions on modern industrial heritage's reproduction, not to cause depreciation of industrial buildings by recognizing contemporary trends and uniform regeneration performance, multifaceted research is needed for creative, effective development on modern industrial heritage which will occur constantly.