• 한국산학기술학회논문지
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• 제16권4호
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• pp.2924-2932
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• 2015

본 연구는 초등학교, 중학교 및 고등학교의 급수설비 사용수량의 분석 통해 급수량 산출자료를 추정하여 학교시설 급수시스템의 적정 급수계획에 필요한 기초자료를 얻고자 하였다. 이를 위하여, 강원지역 6개 도시에 소재하는 초 중 고등학교 54개 학교를 대상으로 5년간의 급수설비 사용수량을 분석하였다, 분석결과, 1) 월평균 사용수량의 평균은 $600.7(m^3/mon)$이었으며, 초등학교와 중학교가 $484.2(m^3/mon)$, 고등학교가 $833.8(m^3/mon)$로 분석 되었다. 2) 학급당 월평균 사용수량의 평균은 $27.0(m^3/mon/class)$이었으며, 초등학교와 중학교가 $24.4(m^3/mon/class)$, 고등학교가 $32.(m^3/mon/class)$로 분석 되었다. 3) 1인1일 평균 사용수량의 평균은 55.8(l/c/d)이었으며, 초등학교와 중학교가 54.4(l/c/d), 고등학교가 58.6(l/c/d)로 분석 되었다.

• 상하수도학회지
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• 제11권1호
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• pp.99-108
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• 1997

This study examined the feasbility of upgrading D waste water treatment plant which treats incoming wastewater by primary sedimentation only. By adding 20-40 ppm of Hi-PAX into the outlet of the aerated grit chamber, BOD and SS removal efficiences were improved from 29% and 36% to 53 % and 73%,respectively. However, chemically enhanced primary treatment failed to meet the upcoming wastewater quality standard(BOD and SS <20 mg/l) consistently. This was suspected to result from the deteriorated plant return stream. The wastewater treatment by chemical treatment should have increased the amount of the sludge to be removed as the sludge production was increased. Chemically enhanced primary treatment is anticipated to consistently produce effluent of the 1996 standards quality by adjusting the amount of the sludge to be removed. Besides BOD and SS removal, chemically enhanced primary treatment resulted in the improved T-P removal from 30% to 64-74%. However, such benefit was not observed in T-N removal. Improved T-P removal will be expected to help control water pollution in Masan bay.

• Corrosion Science and Technology
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• 제21권6호
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• pp.466-475
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• 2022

Surface oxides and intergranular (IG) oxidation phenomena in Alloy 600 depending on hydrogen concentration were characterized to obtain clear insight into the primary water stress corrosion cracking (PWSCC) behavior upon exposure to pressurized water reactor primary water. When hydrogen concentration was between 5 and 30 cm³ H₂/kg H₂O, NiFe₂O₄ and NiO type oxides were found on the surface. NiO type oxides were found inside the oxidized grain boundary when hydrogen concentration was 5 cm³ H₂/kg H₂O. However, only NiFe₂O₄ spinel on the surface and Ni enrichment were observed when hydrogen concentration was 30 cm³ H₂/kg H₂O. These results indicate that the oxidation/reduction reaction of Ni in Alloy 600 depending on hydrogen concentration can considerably affect surface oxidation behavior. It appears that the formation of NiO type oxides in a Ni oxidation state and Ni enrichment in a Ni reduction (or metallic) state are common in primary water. It is believed that the above different oxidation/reduction reactions of Ni in Alloy 600 depending on hydrogen concentration can also significantly affect the resistance to PWSCC of Alloy 600.

• 한국물환경학회지
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• 제36권5호
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• pp.453-467
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• 2020

This study aimed to inventory the water pollutant discharge of wastewater from two facilities, one primary steel manufacturing facility and one petroleum refinery, both of which are located in Korea, and to identify ways to improve the wastewater treatment process through field investigation. Probability evaluation was used to inventory the substances in polluted water. The samples collected in this study included original wastewater, on processing wastewater, and treated water. The general description of wastewater occurrence, major sources, and treatment facilities were also investigated to obtain an integrated database of the pollutants created by different industrial categories. Based on our analysis of raw wastewater and final effluent, the detected pollutants were confirmed by analyzing their presence in the raw or supplemental materials, the potential of formation as byproducts, and the possibility of inclusion as impurities. The compounds detected for each category were screened via investigation of their possible sources and confirmed as the final water pollutant inventories. Thirty kinds of water pollutants were emitted by the primary steel manufacturing facility (reference in case A), including 14 specified hazardous water pollutants. The petroleum refinery (reference in case B) emitted 36 water pollutants, including 16 specified hazardous water pollutants.

• 한국수산과학회지
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• 제20권5호
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• pp.381-390
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• 1987

본 연구는 1985년 5월부터 1986년 5월까지 삼천포 화력발전소를 대상으로 발전소 냉각계통의 가동이 식물플랑크톤의 기초생산력에 미치는 영향을 구명하기 위하여 실시되었다. 발전소 냉각계통이 총기초생산력에 미치는 영향은 평균 $7.5\~58.9\%(4.6\~12.1mgC/m^3/h)$이었으며, 순기초생산력의 경우는 이보다 높은 수준이 $58.7\~83.5\%(8.4\~11.9mgC/m^3/h)$. 영향요인 중 가장 큰 요소는 냉각계통 통과시 입는 기계적인 영향으로 그 범위가 $21.1\~110.7\%$에 달하였다. 삼천포 화력발전소 냉각계통에 이한 식물성탄소에 해당하는 량으로 추계되었다.

• Mass Spectrometry Letters
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• 제14권4호
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• pp.147-152
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• 2023

The increasing demand for two-dimensional imaging analysis using optical or electronic microscopic techniques has led to an increase in the use of simple one-dimensional and two-dimensional mass spectrometry imaging. Among these imaging methods, secondary-ion mass spectrometry (SIMS) has the best spatial resolution using a primary ion beam with a relatively insignificant beam diameter. Until recently, SIMS, which uses high-energy primary ion beams, has not been used to analyze molecules. However, owing to the development of cluster ion beams, it has been actively used to analyze various organic molecules from the surface. Researchers and commercial SIMS companies are developing cluster ion beams to analyze biological samples, including amino acids, peptides, and proteins. In this study, a water droplet ion beam for surface analysis was realized. Water droplets ions were generated via electrospraying in a vacuum without desolvation. The generated ions were accelerated at an energy of 10 keV and collided with the target sample, and secondary ion mass spectra were obtained for the generated ions using ToF-SIMS. Thus, the proposed water droplet ion-beam device showed potential applicability as a primary ion beam in SIMS.

• 한국해양공학회지
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• 제15권4호
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• pp.53-59
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• 2001

The Primary Production of phytoplanktons produces organic matter in high concentration in eutrophicated Hakata Bay, Japan, even during the winter season in spite of low water temperature. Phytoplanktons are considered to have any biological capabilities to keep activities of photosynthesis under the unfavorable conditions, and this affects water quality of the bay. In this study, seasonal variations in primary production efficiency were predicted by using a simple box-type ecosystem model, which introduced the concept of efficiency for absorption of solar radiation energy in relation to growth of phytoplanktons under the low solar radiation intensity. According to the simulation result of primary production, it was organic pollution comes from dissolved organic carbon (DOC) throughout the year, DOC of which is originated from the primary production of phytoplanktons on biological response of the seasonal variation of ambient conditions.

• 한국해양공학회지
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• 제26권1호
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• pp.78-83
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• 2012

The abundant nutrients contained in deep seawater are delivered by natural upwellings from the deep sea to the surface sea. However, the natural upwelling phenomenon is limited to specific areas of the sea; in other areas, the thermocline separates the surface sea from the lower layer. Thus, the surface layer is often deficient in nutritive salts, causing the deterioration of its primary productivity and ultimately leading to an imbalance in the marine ecosystem. Without a consistent supply of nitrogenous nutritive salts, they are absorbed by phytoplankton, resulting in a considerable problem in primary productivity. To solve this issue, a floating type of artificial upwelling system is suggested to artificially pump up, distribute, and diffuse deep seawater containing rich nutritive salts. The key technologies for developing such a floating artificial upwelling system are a floating offshore structure with a large diameter riser, self-supplying energy system, density current generating system, method for estimating the emission and absorption of CO2, and way to evaluate the primary production variation. Strengthening the primary production of the sea by supplying deep seawater to the sea surface will result in a sea environment with abundant fishery resources.

• 한국식품과학회지
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• 제29권3호
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• pp.446-451
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• 1997

구조와 용해도가 다른 4종류의 다당류(옥수수전분, 쌀전분, 고구마전분 및 셀룰로오스)내의 1차 alcohol group을 $25^{\circ}C$에서 2,2,6,6-tetramethyl-1-piperidine oxoammunium (TEMPO)을 사용하여 carboxyl group으로 산화, 전환하였다. TEMPO/bromite 촉매를 이용한 산화반응계에서 최적 pH, TEMPO함량 및 NaBr 함량은 각각 $10.5{\sim}11.0$, 10 mmol/mol of primary alcohol, 0.49 mol/mol primary alcohol이였으며, 반응 최적조건하에서의 산화율은 4종류의 다당류 모두 90%이상이였다. 산화반응은 다당류의 물에 대한 용해도를 매우 증가시켰는 바, 물에 불용성인 셀룰로오스의 경우 산화에 의하여 8.42% (w/v)로 증가되었으며, 옥수수전분, 쌀전분 및 고구마전분과 같이 물에 거의 불용성인(0.10% (w/v) 이하) 다당류들도 약 45% (w/v) 수준으로 물에 대한 용해도가 증가하였다. 또한 본 실험에서의 산화공정에 의하여 제조된 산화물질은 $Ca^{2+}$이온과의 겔 형성능을 갖게됨을 확인하였는 바, 각종 gum, gel 및 film의 새로운 소재로 활용될 수 있을 것으로 기대되었다.

• International Journal of Fluid Machinery and Systems
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• 제6권1호
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• pp.1-10
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• 2013

Jet pump is one type of artificial lifts and is used when depth and deviation of producing wells increases and pressure depletion occurs. In the present study, numerical analysis has been carried out to analyze the flow behavior and find the performance of the jet pump. Reynolds-averaged Navier Stokes equations were solved and k-${\varepsilon}$ turbulence model was used for simulations. Water and light oil as primary fluids were used to pump water, light oil and heavy oil. The ratios of area and length to diameter of the mixing tube were considered as design parameters. The pump efficiency was considered to maximize for the downhole conditions. It was found that the increase in viscosity and density of the secondary fluid reduced efficiency of the system. Water as primary fluid produced better efficiency than the light oil. It was also found that the longer throat length increased efficiency upto 40% if light oil was used as primary fluid and secondary fluid viscosity was 350 cSt.