• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1159-1166
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• 2005

In the present study, a series of laboratory tests with sands of different silt contents, are conducted and methods to assess non-linear behaviors based on in-situ test results are proposed. Modified hyperbolic stress-strain model is used to analyze non-linearity of silty sands in terms of non-linear degradation parameters f and g as a function of silt contents and relative density $D_R$. Stress-strain relationship results were obtained from a series of triaxial tests on sands containing different amounts of silt. Initial shear modulus which was applied to normalize modulus degradation of silty sands were determined based on the resonant column test results. From the laboratory test results, it was observed that, as the relative density increases, values of f decrease and those of g increase. Cone resistance $q_c$ for silty soil condition used in the triaxial tests were estimated based on the cavity expansion analysis. A suggestion to make an estimation of degradation parameters f and g as a function of fine contents is addressed in terms of cone resistance $q_c$ .

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1619-1624
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• 2003

The effect of maize hybrid (Suco and Dekalb 765, DK 765), maturity stage (milk, $R_3$ and 1/2 milk line, $R_5$) and animal diet (Diet 1: 70% lucerne hay+30% maize silage; Diet 2: 50% maize silage+20% sunflower meal+30% maize grain) on ruminal stover dry matter (DM) degradability was studied. Additionally, morphological and chemical plant composition was evaluated. Fodder samples ground at 2 mm were incubated in three Holstein steers (400 kg body weight) using the in situ technique. Ruminal degradation kinetics was studied and the effective degradability (ED) was estimated for an assumed kp of 5%/h. The in situ data was analyzed in a complete randomized block design with the animals as blocks. Significant interactions between hybrid${\times}$diet and maturity${\times}$diet on kinetic digestion parameters were detected. In Diet 1, hybrids did not differ in degradable fraction, kd or ED, although a minor difference (p<0.05) in the soluble fraction was found (25.5 and 23.2% for Suco and DK 765, respectively). In Diet 2, the DK 765 had greater degradable fraction (p<0.001) but smaller (p<0.01) kd than Suco, without differences in the soluble fraction or in ED. Anticipating the harvest increased ED of stover from 37.5% in $R_5$ to 44.6% in $R_3$ (average values across hybrids and diets) due to the increase (p<0.001) in the soluble fraction ($R_5$: 22.6%, $R_3$: 28.8%). It is concluded that hybrids had similar stover in situ DM degradability and that soluble fraction represent the main proportion of degradable substrates. Advancing the date of harvesting may not improve the in situ DM degradability of whole maize plant silage since the increase in stover quality is counteracted by the depression in the grain-to-stover ratio. The diet of the animal consuming silage might not improve stover utilization either.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.1-8
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• 2010

Cometabolic air sparging (CAS) is a new and innovative technology that uses air sparging principles but attempts to optimize in situ contaminant degradation by adding a growth substrate to saturated zone. CAS relies on the degradation of the primary growth substrate and cometabolic substrate transformation in the saturated zone and in the vadose zone for volatilized contaminants. In this study, we have investigated to determine MTBE degradation pattern and microbial activity variation if using propane as a primary substrate at the condition of considering air injection rate and air injection pattern. Laboratory-scale two-dimentional aquifer physical model studies were used and the experimental results were represented that the optimal conditions were as air injection rate of 1,000 mL/min and pulsed air injection pattern (15 min on/off). Over 1,000 mL/min air injection rate and continuous air injection pattern was no affected to increase DO concentration. On the other hand, Injection of propane and propane-utilizing bacteria degraded MTBE partially. And also, injection of propane- and MTBE-utilizing bacteria effectively degraded MTBE and TBA production was observed.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.737-752
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• 2014

As condition-based maintenance (CBM) has risen as a new trend, there has been an active movement to apply information technology for effective implementation of CBM in power plants. This motivation is widespread in operations and maintenance, including monitoring, diagnosis, prognosis, and decision-making on asset management. Thermal efficiency analysis in nuclear power plants (NPPs) is a longstanding concern being updated with new methodologies in an advanced IT environment. It is also a prominent way to differentiate competitiveness in terms of operations and maintenance costs. Although thermal performance tests implemented using industrial codes and standards can provide officially trustworthy results, they are essentially resource-consuming and maybe even a hind-sighted technique rather than a foresighted one, considering their periodicity. Therefore, if more accurate performance monitoring can be achieved using advanced data analysis techniques, we can expect more optimized operations and maintenance. This paper proposes a framework and describes associated methodologies for in-situ thermal performance analysis, which differs from conventional performance monitoring. The methodologies are effective for monitoring, diagnosis, and prognosis in pursuit of CBM. Our enabling techniques cover the intelligent removal of random and systematic errors, deviation detection between a best condition and a currently measured condition, degradation diagnosis using a structured knowledge base, and prognosis for decision-making about maintenance tasks. We also discuss how our new methods can be incorporated with existing performance tests. We provide guidance and directions for developers and end-users interested in in-situ thermal performance management, particularly in NPPs with large steam turbines.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.405-410
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• 2001

Bioremediation is a degradation process of existing organic contaminants in soils and groundwater by indigenous or inoculated microorganisms. This process can provide economical solution as well as safe and effective alternative in remediation technologies. However, it has been suggested that the rate of bioremediation process of organic contaminants by microorganisms can be limited by the concentration of nutrients and TEAs(Terminal Electron Accepters). In in-situ bioremediation, conventional pumping techniques have been used for supplying these additives. However, the injection of these additives is difficult in low permeable soils, and also hindered by preferential flow paths resulting from heterogeneities in high permeable ground. Therefore, the Injection of chemical additives is the most significant concern in in-situ bioremediation. Most recently, electrokinetic technique has been applied into the bioremediation and the injection characteristics under electrokinetics have not been examined in various soil types. Therefore, in this study, electrokinetic injection method is investigated in kaolinite and sand, and the concentration of ammonium(nutrients) and sulfate(TEAs) in soil is presented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.232-236
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• 2005

In-situ Air Sparging (IAS, AS) is a groundwater remediation technique, in which organic contaminants are volatilized into air as it rises from saturated to vadose soil zone. The purpose of this study was to investigate the effect of environmental conditions on the degradation of VOCs (Volatile Organic Compounds) and $CO_2$ in the unsaturated zone and TPH (Total Petroleum Hydrocarbons) in saturated zone of sandy loam. In the laboratory, diesel (10,000 mg TPH/kg)-contaminated saturated soil. After heating the soil for 36 days, the equilibrium temperature of soil reached to $34.9{\pm}2.7^{\circ}C$ and TPH concentration was reduced to 78.9% of the initial value, Volatilization loss of VOCs in TPH was about 2%, The reduction gradient of $CO_2$ concentration was 0.018/day in air space and 0.0007/day in unsaturated zone.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.128-132
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• 1998

The relative disappearance and rate of degradation of dry matter (DM) and neutral detergent fiber (NDF) of nine different feedstuffs were determined by simultaneously suspending groups of substrates, using the nylon bags, in the rumen of males of Sahiwal cattle and Nili-Ravi buffalo. The digestion kinetics of leguminous forages (Lucerne, berseem and cowpeas) and feed byproducts (cotton seed cake, wheat bran and wheat straw) did not differ between the two species. However, the DM and NDF digestibilities and rates of digestion of grasses and wheat straw were greater in buffalo than in cow bulls, indicating that buffaloes are better converters of poor quality roughages than are Sahiwal. The lag time for DM of grasses did not differ between these two species but the NDF lag time was lower in buffalo than in cows, indicating that both the rate and lag time of digestion may be reliable indicators for assessing the NDF quality.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1603-1609
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• 2006

To estimate undegraded intake protein (UIP) fraction in feeds and fodders, on the basis of their neutral detergent insoluble N content was studied. Samples of six feeds and forages were incubated in situ for a time equivalent to their mean retention time, estimated on the basis of their digestibility plus 10 h (to account for a lag in passage of particles from the rumen). The samples were incubated for 0, 25, 50, 75 and 100% of the estimated total mean retention time. UIP value of leguminous forages, obtained from the fractional rates of degradation and passage, were highly correlated with those estimated from samples incubated for 75% of total mean retention time, while incubating the non-leguminous forages and groundnut cake for this point over estimate the UIP fraction.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.1
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• pp.67-76
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• 2007

Bioventing is commonly used for petroleum hydrocarbon (PHC) spills. This process provides better subsurface oxygenation, thus stimulating degradation by indigenous microorganisms. Therefore soil vapor monitoring points (VMPs) are extremely important in determining the potential effectiveness of bioventing and in long-term monitoring of bioventing progress. In this study in-situ soil gas monitoring well (GMW) was developed and presented the pilot test results which recover the contaminated site by bioventing method. The result of application was successful and it was expected that GMW developed could be applied to the evaluation procedure of bioventing effectiveness and long-term remediation potential.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.159-162
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• 1999

All solid state thin film micro-batteries consisting of lithium metal anode, an amorphous LiPON electrolyte and cathode of vanadium oxide have been fabricated and characterized, which were fabricated with cell structure of Li/LiPON/V$_2$O$\sub$5/Pt. The vanadium oxide thin films were formed by d.c. reactive sputtering on Pt current collector. After deposition of vanadium oxide films, in-situ growths of lithium phosphorus oxynitride film were conducted by r.f. sputtering of Li$_3$PO$_4$ target in mixture gas of N$_2$ and O$_2$. The pure metal lithium film was deposited by thermal evaporation on thin film LiPON electrolyte. The cell capacity was about 45${\mu}$Ah/$\textrm{cm}^2$ $\mu\textrm{m}$ after 200 cycle. No appreciable degradation of the cell capacity could be observed after 50 cycles .