• Journal of Korean Society of Water and Wastewater
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• v.27 no.2
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• pp.223-232
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• 2013

In this study, carbon emissions and energy consumption were evaluated to establish a design strategy which has low energy consumption and carbon emission production, by using life cycle energy (LCE) and life cycle $CO_2(LCCO_2)$ calculation methods in life cycle management(LCM) tools. After improvement design projects, the energy consumption and $CO_2$ emission were calculated and compared in three sewage treatment plants (STPs), which are A STP, B STP, and C STP. The reduction of carbon emissions was 28,020.1 ton $CO_{2-}e/yr$, 37,399.6 ton $CO_{2-}e/yr$ and 8,788.3 ton $CO_{2-}e/yr$, respectively. Production of energy was 792 TOE/yr, 1,235 TOE/yr and 1,023 TOE/yr, respectively. As a result, the estimation of energy and energy self-sufficiency was 5.1 %, 14.5 % and 23.5 %, respectively. The result of this study shows the LCM can be contributed to establish strategy for energy and carbon emission reduction in sewage treatment plants.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.299-303
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• 2008

The treated sewage temperature is about $5^{\circ}C$ lower in summer and $5{\sim}10^{\circ}C$ higher in winter than ambient air. It can be used heat pump heat source and is good heat source on high performance of heat pump. In this study, to develop 100RT 2-stage compression heat pump use treated sewage water heat source and system applies to sewage disposal plant. Although heat pump is better performance, the large temperature difference between load and source makes the performance degradation of a heat pump. To solve this problem screw 2-stage compression is considered. The experiment was focused on the system operating performance variations over supply water and treated sewage water a temperature in the field. The results show that system of heating performance is higher then general heat pump and is enough to supply a hot water of $70^{\circ}C$.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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• pp.636-641
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• 2016

Alkaline water electrolysis is commercial hydrogen production technology. It is possible to operate MW scale plant. Because It used non-precious metal for electrode. But It has relatively low current density and low efficiency. In this study, research objective is development of anode for alkaline water electrolysis with low cost, high corrosion resistance and high efficiency. Stainless steel 316L (SUS 316L) was selected for a substrate of electrode. To improve corrosion resistance of substrate, Nickel (Ni) layer was electrodeposited on SUS 316L. Ni-Fe alloy was electrodeposited on the passivated Ni layer as active catalyst for oxygen evolution reaction(OER). We optimized preparation condition of Ni-Fe alloy electrodeposition by changing current density, electrodeposition time and composition ratio of Ni-Fe electrodeposition bath. This electrodes were electrochemically evaluated by using Linear sweep voltammetry (LSV) and Cyclic voltammetry (CV). The Ni-Fe alloy (Ni : Fe = 1 : 1) showed best activity of OER. The optimized electrode decreased overpotential about 40% at $100mA/cm^2$ compared with Ni anode.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1436-1445
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• 2021

To obtain the dynamic characteristics of reactor secondary circuit under transient conditions, the system analysis program was developed in this study, where dynamic models of secondary circuit were established. The heat transfer process and the mechanical energy transfer process are modularized. Models of main equipment were built, including main turbine, condenser, steam pipe and feedwater system. The established models were verified by design value. The simulation of the secondary circuit system was conducted based on the verified models. The system response and characteristics were investigated based on the parameter transients under emergency shutdown and overload. Various operating conditions like turbine emergency shutdown and overspeed, condenser high water level, ejector failures were studied. The secondary circuit system ensures sufficient design margin to withstand the pressure and flow fluctuations. The adjustment of exhaust valve group could maintain the system pressure within a safe range, at the expense of steam quality. The condenser could rapidly take out most heat to avoid overpressure.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1285-1293
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• 2005

The present study was conducted to evaluate and compare the effects of various animal and plant protein sources on piglet' performance, digestibility of amino acids and gut morphology in weaned pigs until 28 days after weaning. The plant protein sources used were soybean meal (SBM), fermented soy protein (FSP), rice protein concentrate (RPC); and animal protein sources tested were, whey protein concentrate (WPC) and fishmeal (FM). Iso-proteinous (21%) diets were formulated and lysine (1.55%) content was similar in all the diets. The level of each protein source added was 6% by replacing SBM to the same extent from the control diet containing 15% SBM. The ADG was higher (p<0.05) in the groups fed animal proteins as compared with plant proteins at all the levels of measurement, except during 15-28 days. The highest ADG was noted in WPC and FM fed diets and lowest in SBM fed diet. The feed intake was higher in animal protein fed groups than plant proteins at all phases, but the feed:gain ratio was not affected by protein sources except during overall (0 to 14 day) measurement which was improved (p<0.05) in animal protein fed diets compared to plant protein sources. The digestibilities of gross energy, dry matter and crude protein were higher in animal protein fed groups than for plant protein fed sources. The apparent ileal digestibilities of essential amino acids like Leu, Thr, and Met were significantly (p<0.05) higher in animal proteins fed animals as compared with plant protein fed animals. But the apparent fecal digestibilities of essential amino acids like Arg and Ile were significantly higher (p<0.05) in plant protein diets than animal protein sources. The villous structure studied by scanning electron microscope were prominent, straight finger-like, although shortened and densely located in FM fed group as compared with others. The lactic acid bacteria and C. perfringens counts were higher in caecal contents of pigs fed plant proteins than the animal proteins. Overall, it could be concluded that animal protein sources in the present study showed better effects on growth performance, nutrient digestibility and gut morphology than plant protein sources.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.255-265
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• 2013

This study was conducted to determine the extent of drought resistance based on physiological responses of Calystegia soldanella under water deficit. In order to investigate the changes of plant growth, stomatal density, photosynthesis, chlorophyll fluorescence, the contents of chlorophyll and carotenoid, osmolality, total ion contents, the contents of carbohydrate and proline, C. soldanella was grown under well watered and drought stressed conditions for 12 days. In this study, water-deficit resulted in remarkable growth inhibition of C. soldanella. The effect of water-deficit on plant growth was associated with low osmotic potential of soil. On day 12 after drought treatment, dry weight, relative water contents, number and area of leaves and stem length were lower than those of control. The stomatal conductance and net photosynthetic rate were significantly reduced in water stressed plant to regulate inner water contents and $CO_2$ exchange through the stomatal pore. Chlorophyll fluorescence and chlorophyll contents were not different in comparison with the control, indicating that the efficiency of photosystem II was not affected by drought stress. This results could be explained that water-deficit in C. soldanella limits the photosynthetic rate and reduces the plant's ability to convert energy to biomass. A significant increase in total ion contents and osmolality was observed on day 7 and day 12. Accumulation of proline in leaves is associated with the osmotic adjustment in C. soldanella to soil water-deficit. Consequently, this increase in osmolality in water stressed plant can be a result in the increase of ion contents and proline.

• BMB Reports
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• v.38 no.6
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• pp.650-660
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• 2005

Proteins accumulated in dry, stratified Arabidopsis seeds or young seedlings, totaled 1100 to 1300 depending on the time of sampling, were analyzed by using immobilized pH gradient 2-DE gel electrophoresis. The molecular identities of 437 polypeptides, encoded by 355 independent genes, were determined by MALDI-TOF or TOF-TOF mass spectrometry. In the sum, 293 were present at all stages and 95 were accumulated during the time of radicle protrusion while another 18 appeared in later stages. Further analysis showed that 226 of the identified polypeptides could be located in different metabolic pathways. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about 1/4, and those involved in metabolism of vitamins and cofactors constituted for about 3% of the total signal intensity in gels prepared from 72 h seedlings. Enzymes related to genetic information processing increased very quickly during early imbibition and reached highest level around 30 h of germination.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.422-425
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• 1988

Pot experiment was conducted to determine the influence of liming on the uptake of $Sr^{90}$ by rice plant. The effect of lime application on the yield of rice plant has approved small slight increase of yield at the level of 150kg/10a only. Liming depressed the nutrient uptake of Mg, K, N and $P_2O_5$ except Ca by the rice plant. The $Sr^{90}$ content of rice plant diminished with increased lime application until to 300kg/10a. At the low pH and exchangeable Ca content of the soil, $Sr^{90}$ uptake of rice plant was high.

• Journal of Soil and Groundwater Environment
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• v.20 no.1
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• pp.56-64
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• 2015

Acid mine drainage occurrence is a serious environmental problem by mining industry, it usually contains high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of the greatest concern. An indigenous plant extract was used to produce calcium carbonate from Canavalia ensiformis as effective biomaterial, and its ability to form the calcium carbonate under stable conditions was compared to that of purified urease. X-ray diffraction and scanning electron microscopy were employed to elucidate the mechanism of calcium carbonate formation from the crude plant extracts. The results revealed that urease in the plant extracts catalyzed the hydrolysis of urea in liquid state cultures and decreased heavy metal amounts in the contaminated soil. The heavy metal amounts were decreased in the leachate from the treated mine soil; 31.7% of As, 65.8% of Mn, 50.6% of Zn, 51.6% of Pb, 45.1% of Cr, and 49.7% of Cu, respectively. The procedure described herein is a simple and beneficial method of calcium carbonate biomineralization without cultivation of microorganisms or further purification of crude extracts. This study suggests that crude plant extracts of Canavalia ensiformis have the potential to be used in place of purified forms of the enzyme during remediation of heavy metal contaminated soil.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.315-322
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• 2008

Valves in power plants are leaking internally by various damages including insertion of foreign objects on seat, seat crack, defects and fatigue crack of stem packing or welds etc. due to severe operating conditions such as high temperature and high pressure for extended period time. Acoustic emission(AE) technology should be applied in order to diagnose precisely and evaluate these valve internal leak. In this paper, results of studies which have accomplished in actual power plant are presented. We have analyzed background noise, AE signal level and frequency spectrum through laboratory tests on the basis of various actual conditions in power plant, and also have considered evaluation methods on the background noise, AE properties and the detectable minimum leak rate according to valve leak conditions through comparing with results of field tests in power plant. As a result of these studies, we conformed that evaluation of internal leak conditions including discrimination of leak or not, and the detectable minimum leak rate is possible, and also it is expected to contribute to safe operation and prevention of energy loss in power plants.