• Title/Summary/Keyword: Environmental damage

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The Effects of pH Change in Extraction Solution on the Heavy Metals Extraction from Soil and Controversial Points for Partial Extraction in Korean Standard Method (용출액의 pH 변화가 토양내 중금속 용출에 미치는 영향과 그에 따른 국내 토양 오염 공정시험방법의 문제점)

  • 오창환;유연희;이평구;이영엽
    • Economic and Environmental Geology
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    • v.36 no.3
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    • pp.159-170
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    • 2003
  • Heavy metals are extracted from Chonju stream sediment, roadside soils and sediments along Honam expressway, soils and tailings from mining area using three different methods (partial extraction in Standard Method, partial extraction method with maintaining 0.1 N of extraction solution and Sequential Extraction Method). In samples having buffer capacity against acid, pH 1 (0.1 N HCl) of extraction solution can not be maintained and pH of extraction solution increases up to 8.0 when partial extraction in Standard Method is used. The averages and ranges of HPE(heavy metals extracted using partial extraction in Standard Method)/HPEM(heavy metals extracted using partial extraction method with maintaining 0.1 N of extraction solution) values are 0.479 and 0.145~0.929 for Cd, 0.534 and 0.078~0.928 for Zn, 0.432 and 0.041~0.992 for Mn, 0.359 and 0.011~0.874 for Cu, 0.150 and 0.018~0.530 for Cr, 0.219 and 0.003~0.853 for Pb, and 0.088 and 1.73${\times}$10$^{-5}$~0.303 for Fe. These data indicate that the difference between HPE and HPEM is large in the order of Fe, Cr, Pb, Cu, Mn, Cd and Zn. The amounts of heavy metals extracted decreases in the follow order; Sum III(sum of fraction I, II, III in sequential extraction)>HPEM>Sum III (sum of fraction I and II)>HPE for Zn, Cd and Mn and Sum III>HPEM>HPE for Cr and Fe. In the case Cr, Sum II is lower than HPEM and higher than HPE. In case of Cu, extracted heavy metals is large in the order Sum IV>HPEM>Sum III HPE. HPE/HPEM value decreases with increasing the amount of HCl used for maintaining 0.1 N of extraction solution. For samples with high buffer capacity, HPE/HPEM value in all elements is lower than 0.2. On the other hand, for samples with low buffer capacity, HPE/HPEM value are over 0.2 and many samples have values higher than 0.6 for Zn, Cd Mn and Cu due to the small difference between Sum II and Sum III, and relatively higher mobility. However, for Fe and Cr, HPE/HPEM value is below 0.2 even for samples with low buffer capacity due to their low mobility and big difference between Sum II and Sum III. This study indicates that the partial extraction method in Korean Standard Method of soil is not suitable for an assessment of soil contamination in area where buffer capacity of soil can be decreased or lost because of a long term exposure to environmental damage such as acidic rain.

Effects of climate change on biodiversity and measures for them (생물다양성에 대한 기후변화의 영향과 그 대책)

  • An, Ji Hong;Lim, Chi Hong;Jung, Song Hie;Kim, A Reum;Lee, Chang Seok
    • Journal of Wetlands Research
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    • v.18 no.4
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    • pp.474-480
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    • 2016
  • In this study, formation background of biodiversity and its changes in the process of geologic history, and effects of climate change on biodiversity and human were discussed and the alternatives to reduce the effects of climate change were suggested. Biodiversity is 'the variety of life' and refers collectively to variation at all levels of biological organization. That is, biodiversity encompasses the genes, species and ecosystems and their interactions. It provides the basis for ecosystems and the services on which all people fundamentally depend. Nevertheless, today, biodiversity is increasingly threatened, usually as the result of human activity. Diverse organisms on earth, which are estimated as 10 to 30 million species, are the result of adaptation and evolution to various environments through long history of four billion years since the birth of life. Countlessly many organisms composing biodiversity have specific characteristics, respectively and are interrelated with each other through diverse relationship. Environment of the earth, on which we live, has also created for long years through extensive relationship and interaction of those organisms. We mankind also live through interrelationship with the other organisms as an organism. The man cannot lives without the other organisms around him. Even though so, human beings accelerate mean extinction rate about 1,000 times compared with that of the past for recent several years. We have to conserve biodiversity for plentiful life of our future generation and are responsible for sustainable use of biodiversity. Korea has achieved faster economic growth than any other countries in the world. On the other hand, Korea had hold originally rich biodiversity as it is not only a peninsula country stretched lengthily from north to south but also three sides are surrounded by sea. But they disappeared increasingly in the process of fast economic growth. Korean people have created specific Korean culture by coexistence with nature through a long history of agriculture, forestry, and fishery. But in recent years, the relationship between Korean and nature became far in the processes of introduction of western culture and development of science and technology and specific natural feature born from harmonious combination between nature and culture disappears more and more. Population of Korea is expected to be reduced as contrasted with world population growing continuously. At this time, we need to restore biodiversity damaged in the processes of rapid population growth and economic development in concert with recovery of natural ecosystem due to population decrease. There were grand extinction events of five times since the birth of life on the earth. Modern extinction is very rapid and human activity is major causal factor. In these respects, it is distinguished from the past one. Climate change is real. Biodiversity is very vulnerable to climate change. If organisms did not find a survival method such as 'adaptation through evolution', 'movement to the other place where they can exist', and so on in the changed environment, they would extinct. In this respect, if climate change is continued, biodiversity should be damaged greatly. Furthermore, climate change would also influence on human life and socio-economic environment through change of biodiversity. Therefore, we need to grasp the effects that climate change influences on biodiversity more actively and further to prepare the alternatives to reduce the damage. Change of phenology, change of distribution range including vegetation shift, disharmony of interaction among organisms, reduction of reproduction and growth rates due to odd food chain, degradation of coral reef, and so on are emerged as the effects of climate change on biodiversity. Expansion of infectious disease, reduction of food production, change of cultivation range of crops, change of fishing ground and time, and so on appear as the effects on human. To solve climate change problem, first of all, we need to mitigate climate change by reducing discharge of warming gases. But even though we now stop discharge of warming gases, climate change is expected to be continued for the time being. In this respect, preparing adaptive strategy of climate change can be more realistic. Continuous monitoring to observe the effects of climate change on biodiversity and establishment of monitoring system have to be preceded over all others. Insurance of diverse ecological spaces where biodiversity can establish, assisted migration, and establishment of horizontal network from south to north and vertical one from lowland to upland ecological networks could be recommended as the alternatives to aid adaptation of biodiversity to the changing climate.

Permission of the Claim that Prohibits Military Aircraft Operation Nearby Residential Area - Supreme Court of Japan, Judgement Heisei 27th (Gyo hi) 512, 513, decided on Dec. 8, 2016 - (군사기지 인근주민의 군용기 비행금지 청구의 허용 여부 - 최고재(最高裁) 2016. 12. 8. 선고 평성(平成) 27년(행(行ヒ)) 제512, 513호 판결 -)

  • Kwon, Chang-Young
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.1
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    • pp.45-79
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    • 2018
  • An increase of airplanes and military aircraft operation lead to significant demanding of residential claims by people who live in nearby airports and military bases due to noise, vibration and residential damages caused by aircraft operations. In recent years, a plaintiff has filed a lawsuit against the defendant, claiming the prohibition of using claimant's possessed land as a helicopter landing route, and the Daejeon High Court was in favour of the plaintiff. Although the Supreme Court later dismissed the Appeal Court decision, it is necessary to discuss the case of setting flight prohibited zone. In Japan, the airport noise lawsuits have been filed for a long time, mainly by environmental groups. Unlike the case that admitted residential damages caused by noise, the Yokohama District Court for the first time sentenced a judgment of the prohibition of the flight. This ruling was partially changed in the appellate court and some of the plaintiffs' claims were adopted. However, the Supreme Court of Japan finally rejected such decision from appeal and district courts. Atsugi Base is an army camp jointly used by the United States and Japan, and residents, live nearby, claim that they are suffering from mental damage such as physical abnormal, insomnia, and life disturbance because of the noise from airplane taking off and landing in the base. An administrative lawsuit was therefore preceded in the Yokohama District Court. The plaintiff requested the Japan Self-Defense Forces(hereinafter 'JSDF') and US military aircraft to be prohibited operating. The court firstly held the limitation of the flight operation from 10pm to 6am, except unavoidable circumstance. The case was appealed. The Supreme Court of Japan dismissed the original judgment on the flight claim of the JSDF aircraft, canceled the first judgment, and rejected the claims of the plaintiffs. The Supreme Court ruled that the exercise of the authority of the Minister of Defense is reasonable since the JSDF aircraft is operating public flight high zone. The court agreed that noise pollution is such an issue for the residents but there are countermeasures which can be taken by concerned parties. In Korea, the residents can sue against the United States or the Republic of Korea or the Ministry of National Defense for the prohibition of the aircraft operation. However, if they claim against US government regarding to the US military flight operation, the Korean court must issue a dismissal order as its jurisdiction exemption. According to the current case law, the Korean courts do not allow a claimant to appeal for the performance of obligation or an anonymous appeal against the Minister of National Defense for prohibiting flight of military aircraft. However, if the Administrative Appeals Act is amended and obligatory performance litigation is introduced, the claim to the Minister of National Defense can be permitted. In order to judge administrative case of the military aircraft operation, trade-off between interests of the residents and difficulties of the third parties should be measured in the court, if the Act is changed and such claims are granted. In this connection, the Minister of National Defense ought to prove and illuminate the profit from the military aircraft operation and it should be significantly greater than the benefits which neighboring residents will get from the prohibiting flight of military aircraft.

Effects of Endocrine Disruptors (NP, DBP and BPA) on Sperm Characteristics and Development of IVF Embryos in Pig

  • Yuh, In Suh;Cheong, Hee Tae;Kim, Jong Taek;Park, In Chul;Park, Choon Keun;Yang, Boo Keun
    • Journal of Animal Science and Technology
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    • v.55 no.4
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    • pp.237-247
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    • 2013
  • This study was to examine single or combined in vitro effects of environmental endocrine disruptors on boar sperm characteristics, oxidative stress damage in sperm and development of porcine IVF embryos. Addition of various concentration of NP (10, 20, $30{\mu}M$), DBP (10, 50, $100{\mu}M$) and BPA (1, 5 or $10{\mu}g/ml$) on boar sperm characteristics such as percentages of sperm motility, viability, membrane integrity and mitochondrial activity were dose-dependently decreased within 3, 6 or 9 hr incubation period (p<0.05). The overall detrimental effects increased with incubation time increasement. NP, DBP and BPA showed the detrimental effects on sperm membrane and mitochondria of energy production organelles affecting cell viability with the dependancy of dose and incubation time. In combination effects, NP ($10{\mu}M$) + DBP ($10{\mu}M$) significantly decreased boar general sperm characteristics for 3 or 6 hr incubation period compared with control (p<0.05). When both of NP and DBP concentrations (NP; $30{\mu}M$, DBP; $100{\mu}M$) increase, the detrimental effects on sperm characteristics were larger than those of low concentration combination (p<0.05). The inhibitory effects of NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$) on sperm characteristics were larger than those of NP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) (p<0.05). DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) decreased sperm characteristics compared with the low concentration combination (DBP $10{\mu}M$ + BPA $1{\mu}g/ml$, p<0.05). This result indicates the detrimental effects of both chemicals on sperm characteristics were dose dependent. Addition of NP ($30{\mu}M$) + DBP ($100{\mu}M$), NP ($30{\mu}M$) + BPA ($10{\mu}g/ml$), DBP ($10{\mu}M$) + BPA ($1{\mu}g/ml$) or DBP ($100{\mu}M$) + BPA ($10{\mu}g/ml$) significantly increased lipid peroxidation for 3 or 6 hr incubation period (p<0.05) compared with no addition control. NP (${\geq}20{\mu}M$) decreased the percentages of IVF embryo development from morulae and blastocyst stages (p<0.05) and its detrimental effects were dose-dependant. BPA 0, 1, 5 or $10{\mu}g/ml$ decreased significantly and dose-dependently the percentage of morulae plus and blastocysts (p<0.05). Combinations of DBP ($100{\mu}M$) plus NP ($30{\mu}M$) and DBP ($100{\mu}M$) plus BPA ($10{\mu}g/ml$) did not affect on morulae and blastocyst development, but NP ($30{\mu}M$) plus BPA ($10{\mu}g/ml$) has significant detrimental effect on embryo development at these stages (p<0.05). These overall results indicate that the partial detrimental effects on boar sperm characteristics and embryo development by NP, DBP, BPA or the combination of these chemicals might be due to the increasement of lipid peroxidation and free radical formation in the cell and there were no specific interaction effects on boar sperm and embryo degeneration among the combined treatments.

Ecological Changes of Insect-damaged Pinus densiflora Stands in the Southern Temperature Forest Zone of Korea (II) (솔잎혹파리 피해적송림(被害赤松林)의 생태학적(生態學的) 연구(硏究) (II))

  • Yim, Kyong Bin;Lee, Kyong Jae;Park, In Hyeop
    • Journal of Korean Society of Forest Science
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    • v.54 no.1
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    • pp.49-59
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    • 1981
  • In order to elucidate the process of plant succession of the Japanese red pine forests caused by pine gall midge, Thecodoplosis japonensis, in the area of Chungbuk and Kyongbuk, 12 study plots, 4 plots from each three districts, were set up. Districts A (Cheongwon)not attacked by this insect, as the check, District B(Gumi) in which the insect outbreak occured 5 years ago, and District C(Yeongdong)in which the insect outbreak occured 10 years ago, were sampled. The surveyed were some environmental factors, the number of woody plants, relative density, relative dominance values, species composition of plots by layer(upper, middle and ground), importance values, species diversity, similarity and dissimilarity index, etc. The results obtained are summarized as follows: The accumulation of litter on the ground was increased with the lengthening the insect damage duration. Through the crown opening and litter accumulation, the light intensity, temperature condition and soil moisture and nutrient content might be altered. According to the changes of species composition were forced. In general, the Genus Quercus, as a compensation species, has sprung up. The relative importance values for Q.aliena, Q.serrata, and Q.variabilis were significantly increased in the insect infested forests. 2. the stand structure and species composition of the insect attacked forest about 5 years later after the outbreak become complex and diverse. However, since this time, the simplicity of these regards become restored up to 10 years after the outbreak. 3. As the synthetic analysis of plant succession process, the relative values calculated from the relative density and the relative dominance values shown the dominant status of Genus Quercus in the heavily damaged forests. In addition, Genus Rhododendron and Genus Lespedeza with higher frequency become the ground vegetation components. They were gradually increased along the time elapsing after the insect out-break. 4. The differences in connection with the soil moisture contents, the organic matter contents which might give some influences to the vegetation change were hardly recognizable statistically among the studied plots by three district groups. We estimated that the annual mean precipitation and the annual mean temperature did not operated any meaningful effects on the vegetation alteration among plots between districts.

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Diversity, Spatial Distribution and Ecological Characteristics of Relict Forest Trees in South Korea (한국 산림유존목의 다양성, 공간 분포 및 생태 특성)

  • CHO, Hyun-Je;Lee, Cheol-Ho;Shin, Joon-Hwan;Bae, Kwan-Ho;Cho, Yong-Chan;Kim, Jun-Soo
    • Journal of Korean Society of Forest Science
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    • v.105 no.4
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    • pp.401-413
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    • 2016
  • Forest resources utilization and variable disturbance history have been affected the rarity and conservation value of forest relict trees, which served as habitat for forest biodiversity, important carbon stock and cultural role include human and natural history in South Korea. This study was conducted to establish the baseline data for forest resources conservation by clarifying species diversity, spatial distribution and ecological characteristics (individual and habitat) of forest relict trees (DBH > 300 cm) based on the data getting from mountain trail, high resolution aerial photos and field professionals and field survey. As results, 54 taxa (18 family 32 genus 48 species 1 subspecies 3 variety and 2 form) as about 22% of tree species in Korea was identified in the field. 837 individuals of forest relict trees were observed and the majority of the trees was in Pinaceae, deciduous Fagaceae and Rosaceae, which families are abundant in population diversity. High elevation area was important to relict trees as mean altitudinal distribution was 1,200 m a.s.l as likely affected by human activity gradients and mid-steep slope and North aspect was important environment for the trees remain. Many individuals exhibited 'damage larger branch' (55.6%) and consequent relatively lower mean canopy coverages (below 80%). Synthetically, present diversity and abundance of relict forest trees in South Korea were the result of complex process among climate variation, local weather and biological factors and the trees of big and old were estimated to important forest biodiversity elements. In the future, clarifying the role and function of relict trees in forest ecosystem, in- and ex- situ programmes for important trees and habitat, and activities for building the background of conservation policy such as "Guideline for identifying and measurement of forest relict trees".

The Improvement Measures for the Establishment of Emergency Management System in Private Security (위험사회의 전개에 따른 민간경비 산업의 대응과제 - 위기관리를 중심으로)

  • Park, Dong-Kyun
    • Korean Security Journal
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    • no.10
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    • pp.103-125
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    • 2005
  • Hazard are defined here as threat to life, well-being, material goods and environmental from the extremes of natural processes or technology. The challenges of natural and technology in increasing the exposure of people and property to risk pose a dilemma for any government seeking the fullest protection for its people and their property. As society progresses and as technology improves and becomes ever more intricate and far reaching, the human species is confronted with increasingly diverse and numerous catastrophic events. Not so infrequently, unfortunately, the impact of either a man-made or natural disaster is compounded by the fact that policy makers have neither prepared themselves or the public to respond appropriately to a disaster once the tragedy has struck. Many concerns have been raised for importance of emergency management after 1990's numerous urban disasters in Korea. Emergency management is the discipline and profession of applying science, technology, planning, and management to deal with extreme events that can injure or kill large numbers of people, cause extensive damage to property, and disrupt community life. When the primary function of private security is to protect lives and property of clients, emergency management should be included in the security service and many countermeasures should be carried out for that purpose. The purpose of this study is to establish ways and means needed to improve the private security emergency management system in Korea. This study is spilt into four chapters. Chapter I is the introduction part. Chapter II introduces the reader to a private security and emergency management theory, and Chapter III deals with the establishment of an effective emergency management system in Korea private security, Chapter IV is a conclusion. Policy makers and private security industry employers in Korea has not concerned with the importance of training and education by lack of recognition and has been passive about qualified guards. And the authorities supervising and the administrating the guards has not recognized the importance of private security and has neglected the training of the guards. In theses contexts, private security should develop and maintain a educational program of emergency management to meet their responsibilities to provide the protection and safety of the clients. Today's modern corporate security director, is, first of all, a competent, well-rounded business executive and, second, a 'service expert'. And, emergency management personnel in private security industry need continuous training.

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Estimation of the Moisture Maximizing Rate based on the Moisture Inflow Direction : A Case Study of Typhoon Rusa in Gangneung Region (수분유입방향을 고려한 강릉지역 태풍 루사의 수분최대화비 산정)

  • Kim, Moon-Hyun;Jung, Il-Won;Im, Eun-Soon;Kwon, Won-Tae
    • Journal of Korea Water Resources Association
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    • v.40 no.9
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    • pp.697-707
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    • 2007
  • In this study, we estimated the PMP(Probable Maximum Precipitation) and its transition in case of the typhoon Rusa which happened the biggest damage of all typhoons in the Korea. Specially, we analysed the moisture maximizing rate under the consideration of meteorological condition based on the orographic property when it hits in Gangneung region. The PMP is calculated by the rate of the maximum persisting 12 hours 1000 hPa dew points and representative persisting 12 hours 1000 hPa dew point. The former is influenced by the moisture inflow regions. These regions are determined by the surface wind direction, 850 hPa moisture flux and streamline, which are the critically different aspects compared to that of previous study. The latter is calculated using statistics program (FARD2002) provided by NIDP(National Institute for Disaster Prevention). In this program, the dew point is calculated by reappearance period 50-year frequency analysis from 5% of the level of significant when probability distribution type is applied extreme type I (Gumbel distribution) and parameter estimation method is used the Moment method. So this study indicated for small basin$(3.76km^2)$ the difference the PMP through new method and through existing result of established storm transposition and DAD(Depth-Area-Duration). Consequently, the moisture maximizing rate is calculated in the moisture inflow regions determined by meteorological fields is higher $0.20{\sim}0.40$ range than that of previous study. And the precipitation is increased $16{\sim}31%$ when this rate is applied for calculation.

Research Trends and Future Directions for R&D Vitalization of Domestic Dairy Industry (국내 유가공산업의 R&D활성화를 위한 연구 동향과 방향)

  • Yoon, Sung-Sik
    • Journal of Dairy Science and Biotechnology
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    • v.29 no.1
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    • pp.23-31
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    • 2011
  • Domestic dairy industry is now standing at the crossroad for planning next fifty years, mainly because economic and environmental situations surrounding Korean peninsula are fast changing. For the aspects of dairy consumption, fresh milk consumed less, while consumption of the other milk and dairy products is slightly increasing every year. In 2010, it is approximately estimated that 1,939,000 tons of raw milk was used and the supply would be short by about 35,000 tons, based on the amounts in the previous year. Currently, multilateral negotiations against US and EU are underway. When it will be in effect in the future, significant damage would be expected in the dairy and livestock sectors, leading to cut domestic milk supply. Quality of farm-gate milk is graded as 1A on average 90% or more, loaded with very low in microbial and somatic cell counts. Therefore, policy implications have to be placed toward switch currently the UHT processing method to Pasteurization or the LTLT technology, by which natural flavors and nutrients in milk mostly remain after heat treatment. Domestic cheese products comprise only 10% and the rest is occupied by the various kinds of imported natural products. The market size keeps increasing up to 65,423,000 tons last year. When it comes to vitalization of our natural cheese industry, cheese whey, which is a main by-product in cheese manufacture, is a critical issue to be solved and also "On-Farm Processing" would be combined with a growth of big dairy companies when few immediate issues among the relevant regulations will be eased and alleviated in the near future. Fermented milk market is recorded as a single area of gradual increase in the past 10 years, Korea. Fermented yogurts with health claims targeted stomach, liver, and intestine are popular and has grown fast in sales amounts. In this context, researches on beneficial probiotic lactic acid bacteria are one of the important projects for domestic milk and dairy industries. Labelling regulations on efficacy or health-promoting effects of functional dairy products, which is the most important issue facing domestic dairy processors, should be urgently examined toward commercial expression of the functionality by lawful means. Colostrum, a nutrition-rich yellowish fluid, is roaded with immune, growth and tissue repair factors. Bovine colostrum, a raw material for immune milk preparations and infant formula, can be used to treat or prevent infections of the gastrointestinal tract. Nanotechnology can be applied to develop new milk and dairy products such as micro-encapsulated lactase milk for consumers suffering lactose intolerance. Raw milk is suggested to be managed by its usage in the processing line because imbalance of supply and demand is structural problem in every country and thus the usage systems as in the advanced dairy countries is worth of bench-marking to stabilize milk supply and demand. Raw milk produced is desirable to divide into the three parts; domestic, import, and buffering purposes. It is strongly recommended that a domestic dairy control center as an institutional framework should be urgently established as is Dairy Board in New Zealand and Australia. Lastly, government policy should be directed to foster the highly-educated people who are majoring in Dairy Sciences or working in the dairy industry by means of financial support in studying and training abroad as well.

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Physico-Chemical Factors on the Growth of Cochlodinium polykrikoides and Nutrient Utilization (Cochlodinium polykrikoides의 성장에 미치는 물리$\cdot$화학적 요인과 영양염 이용)

  • KIM Hyung Chul;LEE Chang Ku;LEE Sam Geun;KIM Hak Gyoon;PARK Chung Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.5
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    • pp.445-456
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    • 2001
  • In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.

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