• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.57-62
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• 1985

The three tide pools of Kanagawagen Aburatsubo coast, Japan were studied for 5 months (June-October, 1991) to know the physicochemical factors and changes of the microflora, In the tide pools salinity was ${\simeq}35\%0$, temperature range was $14{\sim}32^{\circ}C$ and pH range was $7.4{\sim}8.9$. Particulate organic carbon (POC) was $255{\sim}3980\;{\mu}g-at/l$, and total phosphate-P was $1.0{\sim}27.0\;{\mu}g-at/l$. The numbers of suspended bacteria and heterotrophic bacteria on the algae were $10^4{\sim}10^7/ml$ and $10^6{\sim}10^8/g$, respectively. Bacterial flora isolated from the Samples were Acinetobacter spp., Moraxella spp., Flavobacterium spp. and Pseudomonas spp., While Acinetobacter spp. was predominant among them. T. japonicus occurred dominantly with densities of $2200{\sim}7000/l$ during $August{\sim}september$. During this period the sharp increases of the unicellular microalgae and the protozoans were observed. According to the experimental results (POC, total phosphate-P, numbers and composition of bacterial flora), T. japonicus seemed to inhabit the environment with high eutrophication and high variability.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.101-109
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• 2013

Recently, it is certain that the increase of heating and cooling energy consumption by radical change in climate condition has caused serious problems related to environmental and energy concerns associated with increase of fossil fuel usage and carbon dioxide production as well as global warming. So, various actions to reduce greenhouse gas exhaustion and energy consumption have been prepared by world developed countries. Our government has also been trying to seek energy control methods for houses and buildings by proclaiming political polices on low-carbon green growth and construction and performance standards for environment-friendly housing. The energy consumption by buildings approximately reaches 25% of total korea energy consumption, and the increasing rate of energy consumption by buildings is stiffer than the rate by the other industries. The greatest part in the buildings of the energy consumption is building facade. While lots of research projects for reducing energy consumption of the facade have been conducted, but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research presents here a study to improve the insulation property of structural concrete formed by micro form admixture (MFA) with experimentally reviewing the physical, mechanical and thermal characteristics of the concrete. As the results of this experiment, in the case of concrete mixed with MFA, slump loss has been improved. As the mixing ratio of MFA increases, the compressive strength is decreased and thermal conductivity is increased. Also it was found that water-cement ratio increases, the compressive strength is decreased and thermal conductivity is increased. but, there was not big influence by the change of fine aggregate ratio.

• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.153-159
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• 2020

In order to find out the condition of flow in sewer pipes, this study investigated the characteristics of tractive force of sewage flow estimated using actual measured values of water level, velocity, and flowrate in sewers located at uppermost portion in a treatment area during dry weather periods. When the scene of sewage flow was taken by CCTV after cohesive and non-cohesive solids (tofu and sand) were put on the sewer invert, it was found that the solids could be flushed without significant interruption. In sewer with slope of 0.00319, the frequency exceeding the minimum tractive force of sewage during a weekday was zero, while it was 10 per day with slope of 0.00603. During the week of the field observation, the event to exceed the minimum tractive force occurred once, suggesting that sewer odor would potentially increase. Maximum tractive force in sewer with steep slope was 2.9-3.1 N/㎡, but with gentle slope it decreased to 1.6-1.7N/㎡. It was also observed that the interval of time maintained below the criterion of minimum tractive force increased, during weekends compared to weekdays and for the sewage including non-cohesive particles which could enter combined sewers during a storm period. This study found that the sewer sediments formed by direct feces input into sewers, through sewer pipes which were designed meeting the standard sewer design criteria, could be flushed without staying as deposited solids state for a long time.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.5-12
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• 2009

Seed priming is a useful technique for rapid and uniform seed germination as well as early seedling establishment. This experiment was conducted to find out the optimum condition for Sorbus alnifolia seed priming with four concentrations of four reagents in germination property and seedling growth performance. The results are summarized as follows: Percent germination (PG) varied 2.67% to 24.67%, and S. alnifolia seeds had the highest PG in the treatment that were primed in 100mM $KNO_3$ solution for 2 days. Mean germination time was the shortest in 200 mM $KNO_3$ solution for 2 days. Seed priming with $KNO_3$ solutions increased germination speed (GS) and germination performance index (GPI) compared with non-primed seeds. Especially seed primed with 100 mM $KNO_3$ solution for 2 days showed the highest GS and GPI. The highest relative growth rate (RGR) and seedling vigor index (SVI) was significantly (p<0.05) different from the control and other treatments, respectively. RGR of height (0.0071) and root collar diameter (0.0141) of seedling from primed seeds were the highest in 400 mM NaCl solution for 2 days. The highest SVI (5.43) was observed in the seedlings from seeds primed in 100 mM $KNO_3$ solution for 2 days. Consequently, the optimum reagent and concentration were $KNO_3$ and 100 mM for the effective germination and seedling growth in S. alnifolia

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.103-112
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• 2011

This study was carried out on 4 batch reactors to determine the specific ammonium oxidizing rate (SAOR), specific nitrate forming rate (SNFR) and inhibitory degree of nitrifying activities with saline concentrations. Under salt free condition ammonia was consumed during the reaction period within 200 min. When the salt level increased to 10, 20 and 30 g $NaClL^{-1}$ in reactor, ammonia depletion took 250, 300 and above 350 min, respectively. During concentration above 10 g $NaClL^{-1}$, there was nitrite accumulation. Also, at 30 g $NaClL^{-1}$ ammonia did not depleted and $NO_2{^-}$-N accumulated until the final reaction. Nitrate formation rates decreased with increasing salt concentration. SAOR and SNFR showed a decreasing trend as salinity concentrations were increased. The SAOR was reduced from 0.2 to 0.08 mg $NH_4{^+}$-N $g^{-1}VSS\;day^{-1}$ as the salt concentration increased from 0 to 30 g $NaClL^{-1}$. Similarly, the SNFR decreased from 0.26 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline free to 0.1 kg $NO_3{^-}$-N $kg^{-1}VSS\;day^{-1}$ at saline 30 g L-1. A severe inhibition of nitrifiers activity was observed at increased salt concentrations. The inhibition ratio of specific ammonium oxidation rates were 17, 47 and 60% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. The inhibition ratio of specific nitrate forming rates also were inhibited 30, 53 and 62% on the reactor of 10, 20 and 30 g $NaClL^{-1}$ added, respectively. As the salinity concentrations increased from 0 to 30 mg $NaClL^{-1}$, the average MLSS concentration increased from 1,245 to 1,735 $mgL^{-1}$. The SS concentration of supernatant in reactor which settled about 30 minutes was not severely difference between concentration of salt free reactor and one of those high salt contained reactors.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.389-397
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• 2004

본 연구는 GIS를 이용하여 아파트 단지의 UHF대역의 전파장애에 대한 예측모델을 제시한다. 전파예측모델은 기지국 및 중계기 위치설계와 전파음영지역 결정 등 무선네트워크 서비스에 결정적으로 활용된다 기존의 전파예측모델은 한국지형요소나 3차원 공간기술이 반영되지 않고 외국지형기반의 2차원적인 접근으로 개발되어 있다. 특히 많은 사람이 거주하는 아파트단지에 대해서는 고려가 되어 있지 않은 실정이며, 마치 아파트 단지가 일반 건물로 취급되어 전파환경 요소로 분류되지 않은 상태이다. 그리고 전파관리자가 기존 전파 예측모델을 이용한 무선네트워크 설계 및 운용등에 있어 정확한 의사결정지원에 어려움이 많다. 본 연구는 이러한 한계와 문제점을 해결하기 위해서 아파트 단지의 전파에 대한 영향을 3차원 공간밀집, 건물높이, 전파의 전송방향에 대한 건물배치등 3가지 요소로 분류하고 GIS 도구로 그 요소들을 분석하였다. 그 결과로 상관과 회귀분석등 정량적인 방법으로 평가하여 아파트 전파예측모델(GARP)을 개발하여 다음의 결과를 얻었다. 첫째, 아파트 단지가 UHF 대역의 전파에 대한 영향은 전파진행방향성이 57%, 공간밀집이 30%, 건물높이가 13%의 순으로 나타났다. 둘째, 본 연구에서 개발된 아파트 모델은 기존 모델에 비해 평균 6.3dBm, 최소 2.15 ～ 최대 12.48dBm의 개선 효과가 있다. 셋째, 급속히 확산되는 도시 개발에 3차원 공간상에서 전파예측모델을 시뮬레이션하여 전파의 영향을 예측할 수 있으며, 대단지 아파트 건설과 전파환경영향평가의 기초정보 수집에 활용될 수 있다. 본 연구는 GARP모델과 GIS 가시권 분석기능을 이용하여 실제 지형공간상에서 전파경로 손실치를 도시화함으로써 전파관리자가 무선서비스지역 설계, 전파음영지역 판단, 최적 중계기와 기지국 위치 선정에 기여할 것으로 판단된다.하지 않은 지역과 서로 다른 분광특성을 나타내므로 별도의 Segment를 형성하게 된다. 따라서 임상도의 경계선으로부터 획득된 Super-Object의 분광반사 값과 그 안에서 형성된 Sub-Object의 분광반사값의 차이를 이용하여 임상도의 갱신을 위한 변화지역을 탐지하였다.라서 획득한 시추코아에 대해서도 각 연구기관이 전 구간에 대해 동일하게 25%의 소유권을 가지고 있다. ？스굴 시추사업은 2008년까지 수행될 계획이며, 시추작업은 2005년까지 완료될 계획이다. 연구 진행과 관련하여, 공동연구의 명분을 높이고 분석의 효율성을 높이기 위해서 시료채취 및 기초자료 획득은 4개국의 연구원이 모여 공동으로 수행한 후의 결과물을 서로 공유하고, 자세한 전문분야 연구는 각 국의 대표기관이 독립적으로 수행하는 방식을 택하였다 ？스굴에 대한 제1차 시추작업은 2004년 3월 말에 실시하였다. 시추작업 결과, 약 80m의 시추 코아가 성공적으로 회수되어 현재 러시아 이르쿠츠크 지구화학연구소에 보관중이다. 이 시추코아는 2004년 8월 중순경에 4개국 연구팀원들에 의해 공동으로 기재된 후에 분할될 계획이다. 분할된 시료는 국내로 운반되어 다양한 전문분야별 연구에 이용될 것이다. 한편, 제2차 시추작업은 2004년 12월에서 2005년 2월 사이에 실시될 계획이다. 수백만년에 이르는 장기간에 걸쳐 지구환경변화 기록이 보존되어 있는 ？스굴호에 대한 시추사업은 후기 신생대 동안 유라시아 대륙 중부에서 일어난 지구환경 및 기후변화를 이해함과 동시에 이러한 변화가 육상생태계 및 지표지질환경에 미친 영향을 이해하는데 크게 기여할 것이다.lieve in safety with Radioactivity wastes control for harmony with Environment.d by the experiments under vari

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.1-13
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• 2015

Travellers consider extra travel time to be arriving their destination because of uncertainty of travel. So it is important to make predictable highway by providing information of travel time variability to traveller so as to enhance level of service at highway. In order to make predictable highway, it is necessary to develope measures of travel time variability that travellers can easily understand. Recently advanced country including the United States, travel time variability index are actively studied. In earlier study, 95percentile of travel time is considered to be most important calculation index of travel time variability. In this study, is has focused on the propriety analysis of 95percentile of travel time in domestic transportation environment. Result of analysis, All of measures(80percentile of travel time, 90percentile of travel time, 95percentile of travel time) show the tendency to increase when case of weather factor occur compare to normal condition under LOS A~D. Especially 95percentile of travel time increased sensitively.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.49.1-49.1
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• 2014

The NISS (Near-infrared Imaging Spectrometer for Star formation history) onboard NEXTSat-1 is the near-infrared instrument onboard NEXTSat-1 which is being developed by KASI. The imaging low-resolution spectroscopic observation in the near-infrared range for nearby galaxies, low background regions, star-forming regions and so on will be performed on orbit. After the System Requirement Review, the optical design is changed from on-axis to the off-axis telescope which has a wide field of view (2 deg. ${\times}$ 2 deg.) as well as the wide wavelength range from 0.95 to $3.8{\mu}m$. The mechanical structure is considered to endure the launching condition as well as the space environment. The design of relay optics is optimized to maintain the uniform optical performance in the required wavelength range. The stray light analysis is being made to evade a light outside a field of view. The dewar is designed to operate the infrared detector at 80K stage. From the thermal analysis, we confirmed that the telescope can be cooled down to around 200K in order to reduce the large amount of thermal noise. Here, we report the current status of the NISS development.

• Journal of Environmental Science International
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• v.16 no.10
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• pp.1203-1208
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• 2007

Feathers are produced in huge quantities as a waste product at commercial poultry processing plants. Since feathers are almost pure keratin protein, feather wastes represent an alternative to more expensive dietary ingredients for animal feedstuffs. Generally they become feather meal used as animal feed after undergoing physical and chemical treatments. These processes require significant energy and also cause environmental pollutions. Therefore, biodegradation of feather by microorganisms represents an alternative method to prevent environment contamination. The aim of this study was to investigate cultural conditions affecting keratinolytic protease production by Bacillus pumilus RS7. We also assessed the nutritive value of microbial and alkaline feather hydrolysates, The composition of optimal medium for the keratinolytic protease was fructose 0.05%, yeast extract 0.3%, NaCl 0.05%, K2HPO4 0.03%, KH2PO4 0.04% and MgCl2 6H2O 0.01%, respectively. The optimal temperature and initial pH was $30^{\circ}C$ and 9.0, respectively. The keratinolytic protease production under optimal condition reached a maximum after 18 h of cultivation. Total amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $113.8\;{\mu}g/ml$ and $504.9\;{\mu}g/ml$, respectively. Essential amino acid content of feather hydrolysates treated by NaOH and B. pumilius RS7 was $47.2\;{\mu}g/ml$ and $334.0\;{\mu}g/ml$, respectively. Thus, feather hydrolysates have the potential for utilization as an ingredient in animal feed.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.63-71
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• 2011

Portland cement production is under critical review due to high amount of $CO_2$ gas released to the atmosphere. Attempts to increase the utilization of a by-products such as fly ash and ground granulated blast-furnace slag to partially replace the cement in concrete are gathering momentum. But most of by-products is currently dumped in landfills, thus creating a threat to the environment. Many researches on alkali-activated concrete that does not need the presence of cement as a binder have been carried out recently. In this study, we investigated the influence of alkali activator and superplasticizer on the flowability and compressive strength of the alkali-activated mortar in oder to develop cementless alkali-activated concrete using blast furnace slag. In view of the results, we found out that the type and mixture ratio of alkali activator, the type and adding order of superplasticizer results to be significant factors. When cementless alkali-activated mortar using blast furnace slag manufactured with 1:1 the mass ratio of 9M NaOH and sodium silicate, and added superplasticizer before alkali activator in the mixer, we can be secured workability with 180 mm of flow during 1 hours and compressive strength of about 50 MPa under $20^{\circ}C$ curing condition at age of 28days.