• 한국수소및신에너지학회논문집
• /
• 제19권3호
• /
• pp.226-231
• /
• 2008

Cu/Fe/$Al_2O_3$ granules with various sizes have been prepared by a combination of sol-gel and oil drop method for the use in sulfur trioxide decomposition, a subcycle in thermochemical sulfur-iodine cycle to split water in the hydrogen and oxygen. The size of composite granules have been mainly changed by the flow-rate of the gel mixture before dropping in the synthesis. The structural properties of the samples were comparable with granule size. In the reaction, the catalytic activity was enhanced by decreasing size in the entire reaction temperature ranges.

• Journal of Electrochemical Science and Technology
• /
• 제7권1호
• /
• pp.1-12
• /
• 2016

The production of oxygen and hydrogen from solar water splitting has been considered to be an ultimate solution for energy and environmental issues, and over the past few years, nano-sized semiconducting metal oxides alone and with graphene have been shown to have great promise for use in photocatalytic water splitting. It is challenging to find ideal materials for photoelectrochemical water splitting, and these have limited commercial applicability due to critical factors, including their physico-chemical properties, the rate of charge-carrier recombination and limited light absorption. This review article discusses these main features, and recent research progress and major factors affect the performance of the water splitting reaction. The mechanism behind these interactions in transition metal oxides and graphene based nano-structured semiconductors upon illumination has been discussed in detail, and such characteristics are relevant to the design of materials with a superior photocatalytic response towards UV and visible light.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제6권3호
• /
• pp.189-193
• /
• 2001

Critical cell density (CCD), the maximum cell concentration without mutual shading in algal cultures, can be used as a new operating parameter for high-density algal cultures and for the application of the flashing light effect on illuminated algal cultures. CCD is a function of average cell volume and light illumination area. The CCD is thus proposed as an index of estimation of mutual shading in algal cultures. Where cell densities are below the CCD, all the cells in photobioreactors can undergo photosysnthesis at their maximum rate. At cell densities over CCD, mutual shading will occur and some cells in the illumination chamber cannot grow photoautotrophically. When the cell concentration is higher than the CCD, specific oxygen production rates under flashing light were higher than those under continuous light. The CCD was found to be a useful engineering parameter for the application of flashing light, particularly in high-density algal cultures.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1998년도 추계학술대회
• /
• pp.129-130
• /
• 1998

In this paper, We designed the ECG-NIBP-$SpO_2$ patient monitor. This production can measure Electrocardiograph, Heart Rate, Noninvasive Blood Pressure, and Oxygen Saturation for Noninvasive Mehod and can display each information. These informations were implemented by the electrodes of ECG part, the cuff of NIBP module and the finger probe with light sensor of $SpO_2$ without injection of needle or catheter. In addition, We developed a new analysis algorithm and measurement technique for NIBP and $SpO_2$ to observe patient's conditions correctly.

• 미생물학회지
• /
• 제21권1호
• /
• pp.27-35
• /
• 1983

The stoichiometry between the consumption of CO and $O_2$ and the production of $CO_2(2CO+O_2{\rightarrow}2CO_2)$) showed that Pseudomonas carboxydohydrogena grows as a typical aerobic CO oxidizer with CO. The optimal concentration of CO for growth was found to be 30% in gas mixture with air. The initial buffer concentration of the culture medium did not affect the growth of this bacterium. P. carboxydohydrogena is an obligate aerobe and dose not use nitrate as a terminal electron acceptor. The CO dehydrogenase is an inducible and soluble enzyme. The reaction rate and stability were maximal at pH7.5, and the Arrhenius plot revealed an activation energy of 37.7kJ/mol (9.0 Kcal/mol). The crude enzyme used methylene blue, thionin, and toluylene blue as electron acceptors for the oxidation of CO to $Co_2$ under anaerobic conditions. It was found that water must be the source of the second oxygen atom for CO oxidation.

• 상하수도학회지
• /
• 제10권2호
• /
• pp.117-123
• /
• 1996

A bench-scale continuous activated sludge system was operated in order to study the effects of solid waste landfill leachate on municipal wastewater treatment. The leachate sample was collected from Nanjido landfill. During the 7 weeks of operational period, the leachate content in the influent fed to the system was increased stepwise from 3% to 5% and 7%. The solids retention time was the major process control parameter, and it was 10 days. With the municipal wastewater alone, COD removal was 75%. The removal percents, however, decreased to 60% and 45% when the leachate content was 3% and 7%, respectively. For the wastewater spiked with the leachate, the sludge production was higher than for the municipal wastewater alone. Sludge settleability determined by SVI deteriorated with the increase of leachate content. The specific oxygen uptake rate, however, was measured higher as leachate content increased.

• Journal of Plant Biology
• /
• 제20권3호
• /
• pp.119-126
• /
• 1977

The maximum relative growth rate of algae treated with Zinc was shown as follows: 15, 8, 6, 3 and -5% per day for the rather sensitive Chlorella sp. populations, or 14, 7, 5 and 4% per day for the Pleurococcus sp. populations, and 22, 20, 13, 9 and 7% per day for the more resistant Scenedesmus spinosus populations, respectively for the culture medium with 0, 1, 5, 10 and 20 ppm of Zinc treatment. With mixed cultures of Chlorella sp. and Scenedesmus spinosus populations, the growth of the Chlorella sp. population overcame that of the S. spinomsus population from the cultures treated with relatively low concentration of Zinc. On the contrary, the population growth of the latter resistant species overcame that of the former sensitive species when the concentration of Zinc was above 5 ppm Zn of the medium. This paper describes the results of further investigations of the effects evaluated by direct cell counts method, optical density comparisons, oxygen production and consumption determinations and the measurements of the fate of Zinc treated in the solutions.

• 생물환경조절학회지
• /
• 제20권4호
• /
• pp.406-411
• /
• 2011

본 연구는 수확 전 단수처리가 치콘 저장성에 미치는 영향을 알아보고자 실시하였다. 단수처리 후 수확한 치콘은 단수처리 없이 수확한 치콘에 비해 처리시간별로 건물함량의 차이를 보임에 따라 예건효과가 있을 것으로 보여 실험에 임하였다. 단수처리는 치콘의 수확후 호흡률과 에틸렌 발생률에도 영향을 주었는데, 호흡률과 에틸렌 발생률은 각각 12시간과 6시간 처리에서 가장 높은 수준을 보였고, 이보다 처리시간이 길어지면 감소하는 경향을 보였다. 저장 중 생체중 변화를 조사 해 본 결과 6시간 단수처리의 경우 다른 단수처리들에 비해 변화율이 적게 나타났다. 그리고 포장재내의 대기조성 변화를 보았을 때 저장기간이 길어짐에 따라 포장내 산소농도와 이산화탄소 농도는 6시간 단수처리 시 약간의 예건효과를 보이는 듯 보였으나 통계적 유의성은 없는 것으로 판단되었다. 포장내 에틸렌농도는 저장 4일째에 전체적으로 단수처리하지 않은 대조구에 비해 에틸렌 농도가 높게 나타났으나 저장기간이 길어짐에 따라 저장 16일차에는 대조구에 비해 농도가 낮게 나타났으나 통계적 유의성은 없었다. 전체 외관품질을 보았을 때는 단수처리 3시간, 6시간, 24시간 순으로 좋은 평가를 받았으며, 절단면 갈변정도를 보았을 때는 단수처리 6시간이 가장 갈변의 정도가 심하지 않았다. 이상의 결과로 보아 치콘 생산시 수확 전 6시간부터 양액 공급을 중지시키는 단수처리를 할 경우 예건 효과를 가져옴으로써, 치콘의 저장기간 중 수분 손실량을 줄여주고 절단부 갈변 억제 효과를 가져와 저장기간동안 외관상 품질을 유지해줄 수 있을 것으로 생각되어진다.

• Ocean and Polar Research
• /
• 제36권1호
• /
• pp.39-47
• /
• 2014

말쥐치, Thamnaconus modestus는 우리 연근해에서 1970년대 말부터 1980년대에 걸쳐 대표적인 어획종이였으나 지속적인 남획으로 인해 현재 자원이 급격히 감소한 상황이다. 2000년대에 들어오면서 인공종묘생산이 성공하게 되고 현재에는 새로운 양식 대상어종으로서 그 가능성을 타진하고 있다. 이 연구에서는 성체에 진입하는 단계에 있는 말쥐치(전장 $22.6{\pm}0.8$ cm, 총습중 $140.3{\pm}13.9$ g)의 수온($12{\sim}28^{\circ}C$)에 대한 표준대사율을 측정하여 이들 종이 가지는 수온 특성을 파악하고자 하였으며, 각 측정치로부터 그 관련 식을 얻었다. 표준대사율은 수온 $23{\sim}26^{\circ}C$ 부근에서는 수온 상승에 대해 증가 경향이 나타나지 않았으나, $12{\sim}28^{\circ}C$의 수온 범위 전반에서 단위 체중 당 산소소 비율(SOCR, $m/O_2/gWW/h$)의 경우, SOCR = 0.0117WT-0.0135 ($r^2$ = 0.9351), 개체 당 산소소비율(IOCR, $m/O_2/fish/h$)의 경우는, IOCR = 1.8160WT-5.4007 ($r^2$= 0.9428)로 수온 상승에 따라 직선함수로 증가하는 경향을 나타내었다. 그리고 단위 체중 당 산소소비율을 통해 수온민감도($Q_{10}$)를 계산하여 비교한 결과, 수온이 높을수록 낮아지는 경향을 보였는데 외온성 동물의 일반적인 $Q_{10}$ 값인 2~3보다 $12{\sim}15^{\circ}C$에서는 $Q_{10}$ 값이 6.27로 매우 높았고 $23{\sim}28^{\circ}C$에서 $Q_{10}$ 값은 1.30으로 다소 낮아서 난류성 어종의 수온 특성을 보였으며, 이로부터 성체에 진입하는 말쥐치에 있어서 $15{\sim}28^{\circ}C$는 그 적수온대에 속하는 것으로 판단된다.

• 한국환경과학회지
• /
• 제3권3호
• /
• pp.185-195
• /
• 1994

Masan bay is one of the polluted enclosed bays, which has red tides problem and the formation of oxygen deficient water in the bottom layer. Most important factors that cause eutrophication and red tide is nutrient materials containing nitrogen and phosphorus which stem from terrestrial sources and nutrients released from sediment. Therefore, to improve of water quality, reduction of these nutrient loads should be indispensible. At this study, the three-dimensional numerical hydrodynamic and eutrophication model, which were developed by Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the phytoplankton production and also to evaluate the effect of water quality improvement plans on phytoplankton production. In field sorvey, the range of concentrations of chlorophyll-a at surface area was found to be 29.17 - 212.5mg/m3, which were exceeding eutrophication criteria. The constant currents defined by integrating the simulated tidal currents over 1 tidal cycle showed the counterclockwise eddies in the southern part of Budo. The general directions of constant currents were found to be southward at surface and northward at bottom over all the bay. The eutrophication model was calibrated with the data surveyed in the field area in June, 1993. The calculated results are in fairly good agreement with values within relative error of 30%. The pollutant load from the sources such as the input from terrestrial release from the sediment was reduced by the rate of 50, 70, 90, 98% to effect of phytoplankton production. Phytoplankton production was reduced to of the 90% reduction of the input loads from terrestrial sources and 8% in 90% reduction of the load from sediment.