• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.53-62
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• 2009

This study was conducted to investigate characteristics of the non-point source pollution under construction and evaluate available pollution control methods. Suspended solid loading is high when soil disturbs by rainfall and this phenomenon is much more severe at the initial stage of construction than at the final one. There are three methods available for erosion and sediment control, which are check dam, silt fence, and geotextile. Check dam and silt fence are for control of suspense solids and geotextile is for preventing soil erosion during rainfall. They can be installed as temporary control facilities at construction sites. From the comparison of those methods, it was found that geotextile method was the most efficient for the runoff control of non-point source pollution. Check dam and silt fence can remove suspense solids by pore spaces to some degree, but the removal of pollutants mainly occurs through sedimentation. Because the temporary control facilities have limited removal efficiency of pollutant, they often cause civil claims and contamination of water environment. Hence, using a pressurized filtration system along with temporary control facilities, highly enhanced treatment efficiency was anticipated. In addition, the loading capacity of these techniques depends on filtration velocity and input loading. And their pre-treatments are necessary for efficient operation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3341-3352
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• 2011

In this study, characteristics of wastewater treatment of sewage intermittently mixed with industrial wastewater is examined by investigating the operational status of each unit operation and measuring water quality. The bioreactor operating condition was measured for MLSS concentration 2,000~3,000 mg/L, HRT 5.3~16.3 hour, SRT 2.8~66.6 day, and SVI frequently showed the value above 200 which was higher than the optimal range of 50~150. It is thought that the sludge is not in suitable condition for sedimentation caused by the incoming industrial wastewater. When industrial wastewater is come into the system, MLDO inside of bioreactor rapidly increased, rate of nitrification is steeply decreased, and Pin floc. is spilled in the secondary clarifier. In the observance of microorganism showed that various bacterial floc. and ciliata were found as well as actinomycetes and filamentous bacteria(Sphaeotilus) which is known to cause bulking. Efficiency of each unit operation was fairly good in average. However, efficiency of the bioreactor treatment showed high fluctuation by unstable operating condition by intermittently incoming industrial wastewater.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.462-462
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• 2018

국내 신규댐 건설에 있어, 침수토양의 용출에 의한 호내 수질영향에 대해서는 현재까지 정량화된 사례는 찾기 어려우며, 댐 담수 초기에 증가되는 오염원에 대한 정확한 조사자료의 부족으로 담수이후의 수질변화에 대한 정확한 예측이 어려운 실정이다. 따라서 외부 오염부하의 강우시 유입과 퇴적물로부터의 영양염용출 등의 내부 오염부하가 함께 고려된 수질예측기법의 적용이 필요하다. 수몰지 토양 및 호내로부터의 내부부하에 있어서는 퇴적물 내의 다량 존재하는 오염물이 재용출 되거나 퇴적물 내의 화학적 생물학적 반응이 하천 수질에 악영향을 미치게 된다. 대부분 수몰지토양에서 수층으로 용출되는 유기물의 양은 수층에서 퇴적물로 흡수 또는 침강 되는 것보다 많은 경우도 있으며, 오염된 수계에서는 내부 부하량이 과다할 경우 수질 개선을 어렵게 하는 요인이 되고 있다. 따라서 본 연구에서는 2016년 시험담수 예정지인 신규댐 수몰지를 대상으로 토양에 포함된 유기물이 자연상태에서 수체로 용출되는 특성을 분석하여 수질에 미치는 영향을 검토하고자 한다. 댐 수몰지의 토양 시료는 시험담수전 2016년 7월, 토지이용 유형별로 5개지점(논, 밭, 대지, 임야, 하천)에서 시료를 채집하여 총 36일간 용출실험을 실시하였으며, 수층내 용존산소 조건을 호기성 조건과 혐기성 조건으로 나누어 실험하였다. 수질분석은 COD, T-N, T-P, $PO_4-P$등 9개 항목에 대해 실험기간 중 13회 실시하였다. 토양별 점유면적 대비 일 용출량은(kg/day) COD 63 kg/day, T-N 93.6 kg/day, T-P 5.8 kg/day, $PO_4-P$ 4.6 kg/day 였으며, 수몰지 내 토지이용현황별 오염원 기여율은 임야, 밭, 하천, 논, 대지 순 이었다. 본 실험은 수몰지토양의 순수용출량만을 담수개시~36일간 측정한 결과로서 실제 저수지환경에서는 실험값보다 낮을 것으로 판단되며, 수중 수질환경 변화 및 퇴적물의 퇴적 등으로 인하여 원토양으로부터의 용출로 인한 수질에의 영향은 시간의 경과와 함께 변화 또는 감소될 것으로 예상된다. 따라서 본 실험결과는 담수초기의 영향으로 국한하여 해석하는 것이 바람직하며, 보다 장기적인 영향파악을 위해서는 담수 후의 퇴적물의 거동(퇴적현황) 파악 및 담수 후 퇴적물의 장기용출실험을 통한 용출량 검토가 필요하다.

• The Journal of the Petrological Society of Korea
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• v.28 no.2
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• pp.53-69
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• 2019

In the Jirisan area of the Yeongnam Massif, Korea, several ductile shear zones are developed within Precambrian gneiss complex (Jirisan metamorphic rock complex). The ductile shear zones have a general NS- and NNE-striking foliation with westward dipping directions. The foliation developed in the shear zones cut the foliation in gneiss complex. The stretching lineations are well developed in the foliated plane of the shear zone, showing ENE-trend with gentle plunging angle to the ESE direction. Within shear zone, several millimetric to centimetric size of porphyroclasts are deformed strongly as a sigmoid form by ductile shearing. The sigmoid patterns of porphyroclasts in the shear zones indicate the dextral shearing. The spatial distribution of ductile shear zone is characterized by the dominant NS- and NNE-striking dextral sense in the central and eastern regions respectively. In the western part, it develops in NE-striking dextral sense which is the general direction of the Honam shear zone. The U-Pb concordant ages obtained from the two samples, the strongly sheared leucocratic gneiss, are $1,868{\pm}3.8Ma$ and $1,867{\pm}4.0Ma$, respectively, which are consistent with the U-Pb ages reported around the study area. We supposed that the ductile shearing in the study area is occurred about 230~220 Ma during late stage of the continental collision around Korea and is preceded by granitic intrusion related to subduction during 260~230 Ma, which are supported by compiling the age data from sheared gneiss, deformed mafic dyke intruded gneiss complex, and non-deformed igneous rocks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.299-309
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• 2019

This study was designed to assess the quality and quantity of food resources such as the chlorophyll a concentration (Chl-a), the particulate organic carbon (POC) and the particulate organic nitrogen (PON), on blood cocke (Tegillarca granosa Linnaeus) farms from May to November 2017 in the northwestern area of Yeoja Bay, Korea. The values of Chl-a, POC and PON were $1.69-7.68{\mu}g{\cdot}L^{-1}$ (average: $3.48{\mu}g{\cdot}L^{-1}$ in the surface), 0.88-2.58 mM (average: 1.97 mM) and 0.17-0.90 mM (average: 0.54 mM), respectively, and these values were higher in the spring and summer and lower in the autumn. Furthermore, Chl-a and POC had higher values on the bottom layer than those vales on the surface, while PON had higher values on the surface than those values on the bottom. The POC/PON ratio and POC/Chl-a ratio were 1.56-7.88 (average: 3.71 on the surface of the water) and 216-967 (average: 700 on the bottom of the water), respectively, with most of the carbon sources being sediment-accumulated particle organic matter, and the contribution by phytoplankton was assessed as being low. These results show that the food source of the blood cockle farms in the northwest area of Yeoja Bay seems to be abundant in quantity, but this is considered to be very poor in quality.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.177-182
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• 1983

Direct conversion of starchy materials to single cell protein of Sporobolomyces holsaticus FRI Y-5 was investigated. Effect of yeast extract concentration on its cell growth showed that it could utilize more of starch in the medium containing 2.5 g/l of yeast extract. In case of jar fermentor culture, the specific growth rate and cell yield of Sp. holsaticus on soluble starch were calculated to be $0.14\;hr^{-1}$ and 0.425, respectively and its maximum cell concentration was 13.4 g/l. After 80 hr of incubation time, 45.96% of starch was consumed and 45.1% of relative blue value was decreased. Reducing sugars in the starch medium seemed to increase from 4.06 g/l to 6.08 g/l and then to decrease. During fermentor culture, pH of medium was almost not changed in the range of $pH\;7.0{\pm}0.5$. The optimal temperature and pH of Sp. holsaticus amylase activity were $40^{\circ}C$ and pH 7.5, respectively. It was shown from the effect of Tapioca starch concentration on the cell growth that the optimal concentration of Tapioca starch for Sp. holsaticus was lower than that of soluble starch. FRI Y-5 cells settled much slower than Sp. holsaticus IFO 1032 cells and the viscosity vs cell concentration relationship was related to be linear.

• Journal of Life Science
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• v.24 no.2
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• pp.118-127
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• 2014

The kinetic properties and isozyme expression of lactate dehydrogenase (EC 1.1.1.27; LDH) in tissues from Rana catesbeiana I and II collected from February (I) and August (II) were studied. LDH activities, A4 isozyme, and LDH/citrate synthase (EC 4.1.3.7; CS) were high in skeletal muscle from R. catesbeiana I, and LDH $B_4$ isozyme increased in several tissues of R. catesbeiana II. In particular, LDH activities were high in heart and brain tissues from R. catesbeiana II. LDH eye-specific C isozyme, detected by native polyacrylamide gel electrophoresis after immunoprecipitation, was expressed in eye tissue and was more similar to the $B_4$ than $A_4$ isozyme. LDH $A_4$ isozyme was purified by oxamate-linked affinity chromatography, and the molecular weight of subunit A was 32.0 kDa. In R. catesbeiana II, levels of $Km^{PYU}$, $Vmax^{LAC}$, and tolerance to lactate of LDH were high in all tissues, and $Vmax^{PYU}$ of LDH in heart and brain tissue was highly detected. Purified $A_4$ isozyme and LDH in eye tissue were highly tolerate compared to others. The $Km^{LAC}$ value was highly measured compared to $Km^{PYU}$. The degree of inhibition by 10 mM of pyruvate on LDH activities in tissues from R. catesbeiana I and II was more pronounced as the ratio of subunit B increased. As a result, characteristic expression of LDH eye-specific C was found in R. catesbeiana. Anaerobic metabolism seemed to predominate as the LDH of skeletal muscle from I showed higher activity. It also appeared that R. catesbeiana II adapted well to incremental increases in LDH B, becoming tolerant to the lactate of LDH in tissues.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.864-868
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• 2006

댐과 양쪽의 산 능선에 감싸이어 있는 저수지의 모습은 이렇다할만한 특징을 찾아보기가 쉽지 않다. 우리나라의 각지에 건설되어진 다목적댐으로 인해 형성되어진 저수지들을 둘러보아도, 역시 주변의 지형을 자세히 비교해 보기 전에는 구별하기 힘들만큼, 그만큼 외관상으로는 닮아있다. 하지만, 이러한 저수지들이 보여주는 자연현상은 실제로는 너무나도 다양하다. 잔잔한 물 표면의 안쪽에 저마다 눈에 보이지 않는 특성들을 감추고 있으리라 추측해 본다. 하지만, 그 특성을 정량적으로 파악 하기란 좀처럼 쉽지가 않다. 영양염분의 과다 유입으로 부영양화가 초래되면 여기저기서 녹조를 발생 시키고, 또한 홍수나 상류 유역의 토사 붕괴로 인하여 좀처럼 침강되지 않는 미세 입자가 과다 유입되면, 1년 내내 누런 탁수로 몸살을 앓는다. 이처럼, 인간의 눈에 보여 지는 저수지는 '매우 닮은 모습에서 너무나 다른 모습'으로 '계단의 층계변화'와 같은 극단적인 상태 변화만이 파악되어진다. 최근에 들어서, 장비의 발달과 환경에 대한 관심의 고조로 한 달에 한번 많으면 일주일에 한 번씩 현장 조사를 수행하고는 있지만, 지속적으로 저수지를 파악하기 위한 '선형적인 현상'을 보여주기에는 충분하지가 않다. 본 연구에서는, 저수지 수온을 모니터링 함으로서, 홍수와 가뭄과 같은 이벤트 및 계절 변화로 인한 수체의 온도분포를 조사 하였다. 그 방법으로, 자체 개발한 써미스터체인을 용담호의 댐축 지점과 댐축으로부터 상류방향으로 6.6km 떨어진 유입지점의 두 곳에 설치하였으며, 연 중 10분 간격으로 수온데이터를 로거에 저장한 후, 두 달에 한번 정도로 센서 정비 및 데이터 수거를 실시하였다. 그 결과, 우리가 눈으로나 현지관측만으로는 파악할 수 없었던 수체내의 많은 특징을 파악 할 수 있었다.. 중랑천 유역의 소배수구역을 대상으로 연중 발생하는 큰 호우사상에 대해 임의의 강우관측소를 결측지점으로 가정하고 주변의 강우관측소로부터 각각의 방법을 이용해 가중치들을 산정하여 결측지점의 강우량 값을 보정하고자 하였다. 또한 각각의 방법을 이용하여 얻어진 결과에 대해 실측값과 보정값의 오차정도를 평균절대오차법(Mean Absolute Error)과 제곱평균제곱근오차법(Root Mean Squared Error)에 의해 산정하여 보정 방법간의 효율성을 검토하고자 하였다.9년, 그리고 2010년${\sim}$2019년까지 총 4구간으로 나누어 결과를 도출하였으며 예상한 바와 같이 후반기 20년 동안에 세 가지 지표가 취약해 지는 것을 확인할 수 있었고, 특히 2000년부터 2009년까지 10년 동안에는 더욱 취약해짐을 확인할 수 있었다.를 보임에 따라 그 정책적 효과는 때로 역기능적인 결과로 초래하였다. 그럼에도 불구하고 이 연구결과를 통하여 최소한 주식시장(株式市場)에서 위탁증거금제도는 그 제도적 의의가 여전히 있다는 사실이 확인되었다. 또한 우리나라 주식시장에서 통상 과열투기 행위가 빈번히 일어나 주식시장을 교란시킴으로써 건전한 투자풍토조성에 저해된다는 저간의 우려가 매우 커왔으나 표본 기간동안에 대하여 실증분석을 한 결과 주식시장 전체적으로 볼 때 주가변동율(株價變動率), 특히 초과주가변동율(超過株價變動率)에 미치는 영향이 그다지 심각한 정도는 아니었으며 오히려 우리나라의 주식시장은 미국시장에 비해 주가가 비교적 안정적인 수준을 유지해 왔다고 볼 수 있다.36.4%)와 외식을 선호(29.1%)${\lrcorner}$ 하기 때문에 패스트푸드를 이용하게 된 것으로 응답 하였으며, 남 여 대학생간에는 유의한 차이(p<0

• The Korean Journal of Rheology
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• v.10 no.4
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• pp.195-201
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• 1998

We have studied the rheological and electrical properties of two types of electrorheological (ER) fluids based on semi-conductive polymers (poly(p-phenylene) and polyaniline). These semi-conductive polymer-based suspensions showed a dramatic increase in viscosity on the application of the static electric field due to the large value of conductivity ratio between particle and medium. The dynamic yield stresses of these ER suspensions exhibited a quadratic dependence on electric field strength at low electric fields and a linear one for high fields. They showed a maximum and then decreased with increasing bulk conductivity of particles. These yield stress behaviors under the static electric field were found to be closely related to the dielectric properties, which is in accord with Maxwell-Wagner interfacial polarization induced by the conductivity effects. In order to achieve better understanding of interfacial polarization effect on ER response and to improve the stability of ER suspension, different kinds of surfactants were employed for controlling the ER activity as well as for enhancing the colloidal stability of suspensions.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.21-28
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• 1984

The milling property of ti different Australian Wheat varieties (Australian Prime Hard (APH), Australian Hard (AH), Western Australian Wheat (WAW), South Australian Wheat (SAW), Australian Standard White (ASW) and Australian Soft Wheat (SW) was investigated by using $B{\ddot{u}}hler$ test mill. The flour characteristics were evaluated by farinograph, mixograph, amylograph, sedimentation and pelshenke tests. The milling race of Australian wheats varied from 59% to 66%, and that of Suwon 219 (Korean variety) was 65.5%. The milling rate was significantly related to the seed weight but less extent to the bulk density of grain. The flours obtained from the wheat varieties exhibited distinctly different chemical compositions and dough properties. The protein content of the flour varied from 14.47% (APH) to 6.59 % (SW). The gluten forming ability of APH and AH was very high, but very low with ASW and Sw. On the other hand, ASw and WAW showed very high gelatinized viscosity, while SAW marked exceptionally low viscosity.