• Title/Summary/Keyword: 안정성 검토

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A Study on Management of Seafood Wastewater Treatment Facility using Submerged MBR (침지식 MBR을 이용한 수산물 폐수처리장 운영에 관한 연구)

  • Choi, Yong-Bum;Lee, Hae-Seung;Han, Dong-Joon;Kwon, Jae-Hyouk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.7227-7236
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    • 2015
  • The survey revealed that, due to the discharge characteristics of seafood wastewater, irregular inflow loads were caused, making it difficult to treat the wastewater safely. It is crucial for the operation of pressure and floating tanks for the treatment of high-concentration organic wastewater such as seafood wastewater. The survey of operation factors for the pressure and floating tanks revealed this: A/S ratio 0.05 (design criteria 0.01), the pressurized air pressure 8bar(design criteria 6bar), the pressure tank pressure 6bar (design criteria 4.5bar), and HRT 60sec(design criteria: 10sec). Also, the recirculation rate was changed to over 40%(design criteria: 30%), and the surface load rate was changed to under $13.7m^3/m^2{\cdot}hr$(design criteria: under $17.7m^3/m^2{\cdot}hr$); thus, compared to the initial design criteria, the operation factors were changed according to inflow characteristics, thus enhancing the pressure and floating tank performance. The survey of inflow load revealed BOD 140.7%, $COD_{Mn}$ 120.32%, and SS 106.3%, compared to the inflow design criteria, as well as T-N 135.5% and T-P173.3%, higher than the design criteria. The survey of the treatment facility annual operation cost revealed high portions in sludge treatment cost(27.7%) and chemicals costs(26.0%), and the sludge treatment cost will likely further increase due to the ban on ocean dumping. The unit cost for the treatment of seafood wastewater was found to be KRW 3,858 per ton, more than 27 times higher than the sewage treatment cost(KRW 142.6/ton), presumably because the seafood wastewater contains high-concentration organic substances and nutritive salts.

Evaluation of Removal Efficiencies of Heavy Metals Using Brown Seaweed Biosorbent Under Different Biosorption Systems (폐미역을 이용한 생물흡착 시스템별 중금속 제거 효율 평가)

  • Choi, Ik-Won;Seo, Dong-Cheol;Kim, Sung-Un;Kang, Se-Won;Lee, Jun-Bae;Lim, Byung-Jin;Kang, Seok-Jin;Jeon, Weon-Tai;Heo, Jong-Soo;Cho, Ju-Sik
    • Korean Journal of Environmental Agriculture
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    • v.30 no.3
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    • pp.310-315
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    • 2011
  • BACKGROUND: Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leads to serious ecological and health problems. METHODS AND RESULTS: Optimum conditions in continuous-flow stirred tank reactor (CSTR) and packedbed column contactor (PBCC) using brown seaweed biosorbent were investigated. Under optimum conditions from both lab-scale biosorbent systems, removal efficiency of copper (Cu) in a large-scale PBCC system was investigated. Removal capacity of Cu using brown seaweed biosorbent in a lab-scale CSTR system was higher than that in a lab-scale PBCC system. On the other hand, over 48 L/day of flow rate in Cu solution, removal efficiency of Cu in a lab-scale PBCC system was higher than that in a lab-scale CSTR system. Optimum flow rate of Cu was 24 L/day, optimum Cu solution concentration was 100 mg/L. Removal capacity of Cu at different stages was higher in the order of double column biosorption system > single column biosorption system. Under different heavy metals, removal capacities of heavy metal were higher in the order of Pb > Cr > Ni > Mn ${\geq}$ Cu ${\geq}$ Cd ${\fallingdotseq}$ Zn ${\geq}$ Co. Removal capacity of Cu was 138 L in a large-scale PBCC system. Removal capacity of Cu a large-scale PBCC system was similar with in a lab-scale PBCC system. CONCLUSION(s): Therefore, PBCC system using brown seaweed biosorbent was suitable for treating heavy metal wastewater.

Development of New Mushroom Substrate using Kapok Seedcake for Bottle Culture of Oyster Mushroom(Pleurotus ostreatus). (케이폭박을 이용한 병재배 느타리버섯의 대체배지 개발)

  • Won, Seon-Yi;Lee, Yun-Hae;Jeon, Dae-Hoon;Ju, Young-Cheoul;Lee, Yong-Beom
    • The Korean Journal of Mycology
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    • v.38 no.2
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    • pp.130-135
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    • 2010
  • To select the viable alternative substrates among the variable organic substrates for productivity enhancement and production cost-reduction of oyster mushroom in bottle culture, this study was carried out at mushroom research institute of GGRDA in 2007. In bottle culture of oyster mushroom (Plerutus ostreatus), the seedcakes of rape (RS), soybean (SS), coconut (CCS), and kapok (KS) were examined as substitute of cotton seedcake which was primary nutritive material of mushroom growing substrate. The chemical properties of substrate mixed with kapok seedcake is similar to the mixture with cotton seedcake in T-C, T-N, C/N ratio, and other nutrients. Mixed growing substrate containing cotton seedcake and kapok seedcake was superior to other mixtures 99.2% and 99.5%, respectively in spawning ratio and was faster mycellium growth in column test than that of soybeen seedcake, cotton + soybeen seedcake, and coconut seedcake. The period required in first pin-heading was 1-2 days longer in rape and soybeen seedcake mixture. Also there wad no primodia and fruitbody formation at soybeen seedcake mixture which had highest T-N content among the other mixed substrates. Yield per bottle and biological efficiency were highest of 144.6 g and 75.4%, respectively at kapok seedcake mixture. As a result, this study found that cotton seedcake can be replaced with kapok seedcake in bottle culture of oyster mushroom.

Effects of Cohort Size on Male Experience-Earnings Profiles in Korea (코호트 사이즈가 경력-임금 곡선에 미치는 영향)

  • 신영수
    • Korea journal of population studies
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    • v.10 no.1
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    • pp.50-69
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    • 1987
  • There are about 400, 000 Korean ethnics living in Central Asia. Most of Koreans in Central Asia are leading a stable middle class life mostly engaged in farm work. With increase of educational attainment of their children, a number of Koreans are launching into political and academic circles as well as in the cultural world or the press. In recent years, however, the countries in this area(Uzbekistan and Kazakstan) for this study advocate an ethnic united policy to stabilize the politics and society and to carry out efficient transformation from the former socialistic economy to a market oriented economy. In addition, they are trying to recover the culture and the language of each nation which has been forgotten in the assimilation of Russia policy. Koreans have difficulty in adaption to this kind of change. In fact, a number of Koreans lost traditional culture and could not speak their mother language - Korean. Although they more or less maintain national consciousness, they recognize Uzbekistan or Kazakstan as their nation politically. They associated with North Korea unilaterally before the launching of the Perestroika policy. But after the Seoul Olympics held in 1998, there was movement to know and understand South Korea. There has been increased in the investment by Korean companies in Central Asia. Now, what is an alternative idea for Korean community consciousness\ulcorner It can be summarized as follows: 1) The increase of aid to Korean education institute : Considering the last few decades of Russia's strong racial assimilation policy, which leads most Koreans to lost their language and national culture, the priority should go to Koreans education. 2) Local Korean press support : Though Korean newspaper are published and Korean broadcasting is on the air currently in Uzbekistan and Kazakstan, they are suffering from qualified staff and poor financial status. Therefore, positive support should be established for these Korean mass communication media outlets to recover their own function and expand their dissemination powers quickly. 3) Research on the actual condition for Korean Community : It is essential to directly examine the local Korean community's regional distribution, population structure, Korean group's formation and operation, social and cultural understanding, racial consciousness, hope for their mother land and much more. 4) Increase of mother land and education opportunity : To stir up national culture and national consciousness within the Korean community, it is necessary to expand continuous opportunities for mother land visits and education training for local Koreans, especially for second and third generations.

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Responses of Tree Growth and Fruit Production of Persimmon after Lowering Height by Heavy Pruning to Fertilization Rates (강전정에 의한 저수고 감나무의 시비량 조절에 따른 수체 생장 및 과실 생장 반응)

  • Choi, Seong-Tae;Park, Doo-Sang;An, Gwang-Hwan;Kim, Sung-Chul;Choi, Tae-Min;Rho, Chi-Woong
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.2
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    • pp.136-141
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    • 2013
  • Lowering tree height has been a key practice for efficient management of persimmon orchards. This experiment was conducted to assess whether fertilization rates could be reduced after lowering the tree height by heavy pruning. Twelve-year-old 'Uenishiwase' persimmon trees were lowered to 2 m from over 3 m by severe dormant pruning, and then conventional fertilization rate was applied to some trees in April (N 224 g, $P_2O_5$ 172 g, and $K_2O$ 172 g per tree), June (N 112 g and $K_2O$ 99 g per tree), and October (N 112 g and $K_2O$ 99 g per tree). At the same time, 1/3 or 2/3 of the conventional rate and none were applied to other trees, respectively. Non-application decreased shoot length and reduced number of unnecessary secondary shoots by 39% compared with the conventional rate, not affecting yield and weight, color, firmness, and soluble solids of fruits. No significant difference was also found in the yield and the fruit characteristics among the trees fertilized with different rates. Concentrations of soluble sugars, starch, N, and K of dormant shoots in March of the following year were not significantly changed by the different treatments of the previous year. There was no significant difference of shoot growth and yield among the treatments the following year when the same fertilization rate was supplied to all the trees. Results indicated that fertilization rate could be reduced to less than 1/3 of conventional rate to save the cost and stabilize shoot vigor when tree height is lowered by severe pruning.

Development of an Automatic Liquid Feeder for Early Weaned Piglets (조기이유 자돈용 액상사료 자동급이기 개발)

  • 유용희;정일병;안정대;이덕수;강희설;최희철;전병수;박홍석
    • Journal of Animal Environmental Science
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    • v.7 no.1
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    • pp.1-12
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    • 2001
  • This study was conducted to develope an automatic liquid feeder for early weaning piglets and to test the efficacy of the system. The liquid feeder consists of water heating and discharge unit, dry diet storing and discharge unit, mixing and discharge unit, mixed liquid feed-delivering unit, and the central control part which control each unit, feeding frequency and the amount of feeding. For investigating the possibility of practical use, a feeding trial was carried out using eighteen three way crossbred piglets weaned on 19 days of age for the experimental period of six weeks. Experimental diet was provided in liquid form using the automatic liquid feeder for the first three weeks and in dry form for the later three weeks. The water heating and discharge unit exactly supplied warm water by 27 $m\ell$/s, into the mixing unit. The dry diet storing and discharge unit supplied dry feed by 3.7g/s, into the mixing unit. Being compared with the standard growth rate suggested by NRC, average daily gain of the piglets during the first three weeks of liquid feeding was lower by 10%, while it was higher during three weeks of dry feeding and over the whole experimental period by 24 and 17%, respectively. Feed/gain was 1.09, 2.14 and 1.89 for the first 3 weeks, later 3 weeks, and whole period, respectively. Diarrhea was observed for three days from day 3 to day 7 after feeding liquid diet, but no pig died of it. In conclusion, a preliminary test for the newly developed an automatic liquid feeder using 19 days of age weaning piglets showed that the unit was successfully operated without any major problems. Piglets raised on a liquid diet through the unit developed grew less during the first three weeks, but their growth and feed intake were greatly improved thereafter, indicating the developed automatic liquid feeder may be practically used in swine industry.

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Optimum Pre-treatment Method in Constructed Wetlands by Natural Purification Method for Treating Livestock Wastewater (자연정화공법에 의한 인공습지에서 효과적인 축산폐수처리를 위한 최적 전처리방법 구명)

  • Park, Jong-Hwan;Seo, Dong-Cheol;Kim, Ah-Reum;Kim, Sung-Hun;Lee, Seong-Tea;Jeong, Tae-Uk;Choi, Jeong-Ho;Lee, Sang-Won;Cho, Ju-Sik;Kim, Hyun-Ook;Heo, Jong-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.3
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    • pp.425-433
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    • 2011
  • In order to obtain optimum pre-treatment methods and improve T-N and T-P removal efficiencies, removal rates of pollutants in small-scale livestock wastewater treatment apparatus with water plant filtration bed or activated sludge tank were investigated. Based on the results from the optimum pre-treatment in small-scale livestock wastewater treatment apparatus, removal efficiencies of pollutants in livestock wastewater treatment plant with water plant filtration and activated sludge beds. The removal rates of COD, SS, T-N, and T-P in effluent were 83, 89, 63 and 87% in small-scale livestock wastewater treatment apparatus with water plant filtration bed, respectively. The removal rates of COD, SS, T-N, and T-P in effluent were 96, 95, 86 and 92% in small-scale livestock wastewater treatment apparatus with activated sludge tank, respectively. For increasing the COD, SS, T-N, and T-P removals in small-scale livestock wastewater treatment apparatus, the water plant filtration and activated sludge beds are recommended. In livestock wastewater treatment plant with water plant filtration ($1^{st}$ treatment) and activated sludge ($2^{nd}$ treatment) beds, the concentrations of COD, SS, T-N, and T-P in effluent were 39, 15, 42 and $1mg\;L^{-1}$, respectively. It was shown that the concentrations of COD, SS, T-N, and T-P met acceptable effluent quality standard for livestock wastewater. Based on the above results, the removal rates of COD, SS, T-N, and T-P in effluent were over 99.8, 99.9, 99.2, and 99.9% in livestock wastewater treatment plant, respectively.

Thailand in 2016: The Death of King Bhumibol Adulyadej and the Uncertainty in Political Economy (태국 2016: 푸미폰 국왕의 서거와 정치·경제적 불확실성)

  • KIM, Hong Koo;LEE, Mi Ji
    • The Southeast Asian review
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    • v.27 no.2
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    • pp.245-271
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    • 2017
  • The purpose of this study is to examine and assess the major characteristics and changes of politics, economy, and diplomacy in Thailand in 2016. Specifically, it reviewed the New Constitution that was passed in 2016, the confrontation between different political forces and the trend of military regime around the New Constitution, and the political instability caused by the accession of the new king to the throne. This study also set out to figure out changes to the economy and foreign relations of the country, including its relations with South Korea, under the military regime and make predictions for the impact and future prospects of King Bhumibol Adulyadej's death on the politics and economy of the country. In 2016, the politics of Thailand took a step further toward the transfer of power to civil government and established a foundation for an authoritarian system. The draft of the New Constitution, which does not seem to be democratic, was approved by a referendum and enabled the military authorities to continue their political interventions, even after the general election. The New Constitution, in particular, reduces the power of political parties itself in addition to simply keeping the Thaksin's party in check; thus, anticipating ongoing conflicts between the military authorities and political parties. In this situation, the absence of King Bhumibol Adulyadej, who used to play a decisive role in promoting the political stability of the country, and the accession of the new king to the throne raise concerns about the acceleration of political instability, which has continued after the coup and influenced the diplomatic relations of the country. Today, Thailand is distancing itself from Western nations that do not recognize the current military regime including the U.S.A. and EU member states and instead maintains a rapidly friendly and close relation with China. In 2016, the economy of Thailand made a gradual recovery rather than high growth. The death of King Bhumibol Adulyadej has exerted limited direct economic impacts only on individual consumption and tourism and is not likely to cause a recession. An economic crisis will, however, be unavoidable if the political confrontations escalate before the general election to transfer power to the civil government.

Evaluating the Strategic Reaction of Labor Union Movement toward Labor Reforms: The Two National Centers' Reaction toward Park, Guen-Hye Government's Labor Market Restructuring (노동개혁국면에 있어 노조운동의 대응전략에 관한 평가: 박근혜정부의 노동시장 구조개혁에 대한 양노총의 대응을 중심으로)

  • Lee, Byoung-Hoon
    • 한국사회정책
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    • v.23 no.1
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    • pp.1-23
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    • 2016
  • This study evaluates the strategic capacity of Korean labor union movement by examining policy alternatives and strategic steps that the Federation of Korean Trade Unions and the Korean Confederation of Trade Unions have shown in response to Park Geun-Hye government's labor market structuring policies. While the government-led labor reform was carried out as intended, organized labor has not simply failed to achieve progressive labor reforms to enhance employment security, but also to exert their strategic capacity effectively for preventing Park's labor market flexibilization policies. The two national centers have not been able to exert their strategic capacity (such as intermediating, framing, articulating, learning) for mobilizing the resources of internal solidarity, network embeddedness, narrative discourse, and organizational infrastructure. In particular, the formation and diffusion of public discourse is a significant part of strategic capacity of labor unions dealing with the labor politics of labor market restructuring, since organized labor, which is under the unfavorable constraints of limited movement resources and power imbalance with the business circle, needs to mobilize massive support and participation from union members and civil society organizations. In this light, it becomes of more importance for labor union movement to exert their strategic capacity toward internal solidarity and network embeddedness in the stage of labor market reforms. Under the recent stage of labor reforms, however, the labor unions has not harnessed their movement resources effectively, but undertaken their protest in a traditional manner, thereby losing its public efficacy from inside and outside. Moreover, it is necessary to build and activate the network of organic solidarity among organized labor, civil society organizations and progressive political parties, in order to cope with the pro-business coalition of power elites for accomplishing pro-labor reforms.

Physico-Chemical Properties of Aggregate By-Products as Artificial Soil Materials (골재 부산물의 용토재 활용을 위한 특성 분석)

  • Yang, Su-Chan;Jung, Yeong-Sang;Kim, Dong-Wook;Shim, Gyu-Seop
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.5
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    • pp.418-428
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    • 2007
  • Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.