• 한국산림과학회지
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• 제103권1호
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• pp.80-86
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• 2014

산림유역의 토지이용 변화가 호수의 토사퇴적속도에 미치는 영향을 조사하기 위해 $^{210}Pb$ 연대측정을 수행하였다. 평상시 타코부호수는 쿠시로강으로 유출되지만 쿠시로강의 수위가 증가하면 역류현상으로 인해 쿠시로강에 유출된 다량의 세립토사가 호수로 유입되고 있어 호수 유출지점의 토사퇴적속도를 증가시키고 있었다. 그래서 호수에서 유출입하는 하천 주변의 토사퇴적물에서 $^{210}Pb$ 농도는 많은 양의 토사 퇴적의 영향으로 $^{210}Pb$ 농도가 희석되어 비교적 낮은 값을 나타내고 있었으며 지수함수적으로 감소하는 경향도 나타나지 않았다. 따라서 본 연구에서는 CRS 모델의 $^{210}Pb$ 연대측정법을 사용하였고, CRS 모델의 연대는 $^{137}Cs$ 연대(1963년)와 잘 일치하였다. 타코부호수에서 과거 100~150년 정도의 토사퇴적속도를 조사한 결과, 유역에서 인위적 개발이 없는 1880년대 이전 자연상태에서는 토사퇴적량이 $0.01{\sim}0.03g/cm^2/year$였고, 산림벌채와 하천공사가 시작된 1880년대~1940년대에는 $0.03{\sim}0.09g/cm^2/year$으로 토사퇴적이 증가하였다. 특히 유역에서 산림벌채, 하천공사, 농업개발과 임도 개설이 진행된 1980년대 이후에는 토사퇴적속도가 $0.09{\sim}0.84g/cm^2/year$로 자연상태보다 9~28배 증가하여 호수의 수심이 얕아지는 현상을 가속시키고 있는 것으로 나타났다.

• 대한수의학회지
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• 제31권3호
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• pp.259-264
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• 1991

The proteins of the race horse erythrocyte membrane were analysed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate(SDS-PAGE), and their relations to the fast erythrocyte sedimentation rate(ESR) of the race horse were investigated. The erythrocyte sedimentation rate of race horse were very fast compared with the human one(33 times <$90^{\circ}-plastic-ESR/30m$> and 25 times <$90^{\circ}-micro-ESR/30m$> as fast as the human one) are reported previously. Although the general protein profiles of the race horse erythrocyte membranes were almost similar to that of human, band 3 content was showing higher in race horse (34.7%) than in human (25.3%). The glycoprotein profiles of the race horse erythrocyte membranes revealed by periodic acid Schiff's(PAS) stain showed a marked difference from that of human. The PAS-1(glycophorin) and PAS-2(sialoglycoprotein) present in human erythrocyte memo brane were almost absent from the Holstein and race horse erythrocyte membranes, but PAS-2 was more in only race horse from that of human. Instead, the bovine erythrocyte membranes showed a strong PAS-B near the origin of the electrophorograms and the race horse erythrocyte membranes showed a strong PAS-negative band near the end of the electrophorograms, which is named as PAS-E in this study. These results suggest that the fast sedimentation rate of race horse erythrocyte is due in part to the presence of more band 3 protein fraction and PAS-E glycoproteins in the race horse erythrocytes.

• 생태와환경
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• 제42권4호
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• pp.413-421
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• 2009

Eleven lake sediment core samples were obtained and analyzed to develop a chronology using $^{137}Cs$ (in 1963) and two tephra layers (Ko-c2 in 1694 and Ta-a in 1739). Sedimentation rates estimated for the past ca 300 years in Lake Shirarutoro indicated that catchment development has influenced the shallowing process in the lake by increasing sediment production. The sediment yield under initial land-use development conditions for the first two periods was estimated as 514 tons $yr^{-1}$ from 1694 to 1739 and 542 tons $yr^{-1}$ from 1739~1963. The development of the Shirarutoro catchment intensified in the 1960s with deforestation and agriculture activity leading to an increased sediment yield of 1261 tons $yr^{-1}$ after 1963. The sediment yields after intensified land use development, such as forestry and agricultural development, were about 2 times higher than that under initial development conditions, leading to accelerated lake shallowing over the last ca 50 years. Sedimentation rates differed with location in the lake because of spatial variation in the sediment flux from the contributing rivers and their catchments. The sedimentation rates before 1963 were low in all sites except for one site close to the Shirarutoroetoro River. The sedimentation rate in 1739~1963 was accumulated mostly at the inflow of the Shirarutoroetoro River by sediment production associated with forestry for charcoal production and initial agricultural development. The sedimentation rate after 1963 increased. In particular, the southern zone of the lake near the conjunction with the Kushiro River had a high sedimentation rate, which is attributable to sediment inflow back from the Kushiro River during floods.

• 한국세라믹학회지
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• 제47권3호
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• pp.232-236
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• 2010

In recent years abrasive water jet (AWJ) has received significant attention as a technology used in the manufacturing industry for cutting materials. In this paper we report the development of a new preparation method of abrasives for water jet by using an air bubbling sedimentation rate control technique. The SiC abrasives prepared by an air bubbling sedimentation rate control technique using latex resin are found to be superior to the conventional abrasives not only in surface roughness uniformity but also in lifetime. The AWJ test results also show that the former has also better impact-resistance and wear-resistance than the latter.

• 한국임상수의학회지
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• 제16권1호
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• pp.8-12
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• 1999

The erythrocyte sedimentation rate (ESR) test could be applied well in clinic of men, horses or dogs. But the ESR test was not applied to clinic ruminants except for buffaloes since it was too low measure. To overcome this problem angled tube method was developed. This method was found to be useful for making diagnosis and prognosis. The results were summarized as follows. 1. In the early pregnancy condition, corrected ESR did not changed when compared with normal valures. 2. In the middle pregnancy condition, corrected ESR was increased when compeared with normal valures. 3. In the latter pregnancy condition, corrected ESR was increased when compeared with normal valures. 4. After parturition condition, corrected ESR did not changed when compeared with normal valures.

• 한국해안·해양공학회논문집
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• 제31권6호
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• pp.450-457
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• 2019

항구 주변 하천의 퇴적현상은 하천에 위치한 항구들이 공통적으로 직면하고 있는 문제이나, 그 심각성은 퇴적 속도, 수로 모양 및 크기, 강의 유체 역학적 거동 및 항구의 중요성에 따라 달라진다. 미얀마의 가장 큰 항구인 양곤항이 위치한 양곤강의 높은 퇴적율은 경제적인 측면에서 해결이 절실한 심각한 문제이다. 높은 퇴적물 침강 속도의 결과로 나타나는 양곤강, 파젠달 크릭 및 바고강이 합류하는 지역의 얕은 수심은 양곤항으로 향하는 항로를 막을 뿐만 아니라 양곤항으로 향하는 선박의 크기도 제한한다. 미얀마의 경제발전은 양곤항을 통한 교역에 크게 의존하기 때문에 양곤강의 퇴적물 수송 문제를 해결하기 위해 이 지역의 퇴적현상을 이해하는 연구가 필요하다. 본 논문은 Bagnold(1966) 이론을 적용하여 퇴적물 수송량을 계산하고 양곤 강의 강바닥 고도 변화를 예측하는 것을 목표로 한다. 양곤 강의 우기와 건기 사이의 상하수 운송에서 큰 차이가 발견 되며, 따라서 운송 된 퇴적물이 감소하는 건기에는 침강 문제가 더 심해진다. 건기에 계산한 퇴적율에 따르면 문제가 되는 양곤항 인근 하상 상승률은 연간 약 0.063 m로, 이 지역 연간 준설량을 고려할 때 향 후 50년간 하상이 약 3.15 m 상승할 것으로 예상되며 정확한 예측을 위해 보다 정밀한 관측과 수치모델 등을 사용한 심화연구과 필요하다.

• 대한수의학회지
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• 제29권1호
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• pp.13-20
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• 1989

The proteins of the bovine erythrocyte membrane were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate, and their relations to the slow sedimentation rate of bovine erythrocytes were investigated by treating the erythrocytes with trypsin. The erythrocyte sedimentation rates of bovine erythrocytes from Holstein and Korean native cattle were very slow compared with the human one (1/7 as slow as the human one) as reported previously. However, when human and Holstein erythrocytes were treated with trypsin (0.2 and 0.5 mg/ml) for 1 hour at ${37^{\circ}C}$, their sedimentation rates were markedly accelerated while the sedimentation rate of Korean native cattle's erythrocytes were not affected. Although the general protein profiles of the bovine erythrocyte membranes were almost similar to that of human, bovine erythrocyte membranes showed one additional protein band, called band Q in this study, which migrated electrophoretically to the mid-position between band 2 and band 3 in human erythrocyte membranes. Treatment of Holstein and human erythrocytes with trypsin caused a decrease or disapperance of the band Q from the erythrocyte membrane. Although the band Q in Korean native cattle's erythroyte membrane was decreased by trypsin treatment of the erythrocytes, the magnitude of the decrement was not so pronounced as in the case of human and Holstein erythrocytes. The glycoprotein profiles of the bovine erythrocyte membranes revealed by periodic acid-Schiff stain showed a marked difference from that of human. The PAS-1 (glycophorin) and PAS-2 (sialoglycoprotein) present in human erythrocyte membrane were almost absent from the bovine erythrocyte membranes. Instead, the bovine erythrocyte membranes showed a strong PAS-positive band near the origin of the electrophorograms, which is named as PAS-B in this study. The PAS-B band was disappered completely by the trypsin treatment of Holstein erythrocytes whereas the PAS-B band in Korean native cattle's erythrocyte membrane still remained after the trypsin treatment. The trypsin treatment of Korean native cattle's erythrocytes, however, led to the appearance of small molecular weight peptides, indicating that the high molecular weight glycoproteins were degraded by trypsin as in human and Holstein ones. These results suggest that the slow sedimentation rate of bovine erythrocytes is due in part to the presence of band Q protein fraction and PAS-B glycoprotein in the bovine erythrocytes.

• 한국물환경학회지
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• 제29권6호
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• pp.799-807
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• 2013

Reservoir sedimentation is one of the major concerns for sustainable reservoir operation. Since sediment concentration of the rivers in the Himalayan Mountain is very high, a proper sediment management scheme is necessary. This paper presents long-term reservoir sedimentation and sediment flushing based on the gate operation. Focused on the reservoir to be constructed for the Patrind hydropower project in Pakistan, 4 different flushing scenarios were proposed in this study to prevent successive sedimentation. By extending flushing period and by increasing the flushing discharge for 2 times, the flushing rate increases up to 53.2% and 43.6% in proportion to flushing period and discharge, respectively. Based on the simulation presented in this paper, it is expected to establish efficient sediment management plan to increase hydro power generation and sediment flushing simultaneously.

• 상하수도학회지
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• 제18권2호
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• pp.191-200
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• 2004

DAF process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when the freshwater blooms occut or raw water turbidity become high. Pre-sedimentation iS prepared in case when raw water turbidity is very high by rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than conventional sedimentation process. Moreover, low-density particles (algae and alum flocs) are easily separated while it is difficult to remove in sedimentation. One of the main concerns in adoption of DAF (Dissolved Air-Flotation) process is a high raw water turbidity problem. That is, DAF is not adequate for raw water, which is more turbid than 100NTU. In order to avoid this problem, pre-sedimentation basins are prepared in DAF plant to decrease the turbidity of DAF influent. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, DAF process coupled with sedimentation is suggested that pre-sedimentation with optimum coagulation prior to DAF would be appropriate.

• 한국환경과학회지
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• 제10권2호
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• pp.113-117
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• 2001

This study was conducted to investigate the effect of the prechlorination on algal removal by application of a varying amount of different coagulants, such as LAC, PAC, PACS following the process of coagulation and sedimentation of algae in the Nakdong River. The samples used as a source for the raw water of the Nakdong River were collected from the D Water Purification Plant in Taegu city. With the application of the process of prechlorination, the removal rate of the algae was increased from 10~25% for Synedra spp., 20~35% for diatoms and 4~17% for turbidity. Generally, the removal rate of the algae was increased with the increase of the concentration of the coagulants. The PAC and PACS showed 5% higher removal rate for turbidity as compared to the LAS. On the hand, LAS showed 12% higher removal rate for Synedra spp. as compared to the PAC and PACS. The variations in the removal rate of diatoms with the change of coagulant were not significant. In conclusion, the application of LAS, polymeric coagulant and chlorination for at least 20 minutes could be considered as a reliable treatment process for the removal of source water containing a variety of algae.