• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.185-190
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• 2000

TAO system and solid-liquid separation (28mesh filter and 200mesh filter) were applied in processing piggery slurry to see the reduction of N and P and to draw the efficiency in reducing manure application area. The results are as follows; 1. The amount of N and P in slurry of $4.6m^3/day$ was 22.5kg/day ($4,893mg/{\ell}$) and 7.32kg/day ($1,592mg/{\ell}$). 2. Reduction rate of N and P by TAO reactor was 9.9 kg/day (46.0%) and 3.47kg/day(34.0%). 3. Reduction rate of N and P by Solid-liquid separation was 10.5kg/day (46.6%) and 5.12kg/day (69.8%). 4. One the basis of the amount of nitrogen composting, the square size of liquid manure sprinkled area was reduced from 74.6ha/y to 39.0ha/y in rice paddy, and from 63.2ha/y to 33.0ha/y by the treatment.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.26-34
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• 2013

The multiphase flow analysis related to phase change can be adapted to lots of areas such as evaporation and condensation has many interesting branches due to complicated phenomenon. In this study, the experimental investigation of cryogenic liquid in the porous media with various densities was shown how the cryogenic liquid behaves in the porous structure. For this study, permeability behaviors under different applying pressure of the glass wool with different bulk densities are discussed. Experimental investigation on the behavior of cryogenic liquefied nitrogen in the porous media is conducted. The result was that the non linearity of pressure gradient with location is increased and the permeability is decreased as the bulk density of glass wool increased. Lastly, simulation results with CFD commercial package program are used to realize the cryogenic liquid's flow in porous media to compare the finding with experimental results.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.629-632
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• 1999

Constructed wetlands are being used for the removal of nutrients from livestock wastewater. However, natural vegetation typically used in constructed wetlands does not have marketable value. As an alternative, agronomic plants grown under flooded or saturated soil conditions that promote denitrification can be used. Studies on constructed wetlands for swine wastewater were conducted in wetland cells that contained either natural wetland plants or a combination of soybeans and rice for two years with the objective of maximum nitrogen reduction to minimize the amount of land required for terminal treatment. Three systems, of two 3.6 by 33.5 m wetland cells connected in series were used; two systems each contained a different combination of emergent wetland vegetation: rush/bulrush (system 1) and bur-reed/cattail (system 2). The third system contained soybean (Glycine max) in saturated-soil-culture (SSC) in the first cell, and flooded rice (Oryza sativa) in the second cell. Nitrogen (N) loading rates of 3 and $10kg\;ha^{-1}\;day^{-1}$ were used in the first and second years, respectively. These loading rates were obtained by mixing swine lagoon liquid with fresh water before it was applied to the wetland. The nutrient removal efficiency was similar in the rush/bulrush, bur-reed/cattails and agronomic plant systems. Mean mass removal of N was 94 % at the loading rate of $3kg\;N\;ha^{-1}\;day^{-1}$ and decreased to 71% at the higher rate of $10kg\;N\;ha^{-1}\;day^{-1}$. The two years means for above-ground dry matter production for rush/bulrushes and bur-reed/cattails was l2 and $33Mg\;ha^{-1}$, respectively. Flooded rice yield was $4.5Mg\;ha^{-1}$ and soybean grown in saturation culture yielded $2.8Mg\;ha^{-1}$. Additionally, the performance of seven soybean cultivars using SSC in constructed wetlands with swine wastewater as the water source was evaluated for two years, The cultivar Young had the highest yield with 4.0 and $2.8Mg\;ha^{-1}$ in each year, This indicated that production of acceptable soybean yields in constructed wetlands seems feasible with SSC using swine lagoon liquid. Two microcosms studies were established to further investigate the management of constructed wetlands. In the first microcosm experiment, the effects of swine lagoon liquid on the growth of wetland plants at half (about 175 mg/l ammonia) and full strength (about 350 mg/l ammonia) was investigated. It was concluded that wetland plants can grow well in at least half strength lagoon liquid. In the second microcosm experiment, sequencing nitrification-wetland treatments was studied. When nitrified lagoon liquid was added in batch applications ($48kg\;N\;ha^{-1}\;day^{-1}$) to wetland microcosms the nitrogen removal rate was four to five times higher than when non-nitrified lagoon liquid was added. Wetland microcosms with plants were more effective than those with bare soil. These results suggest that vegetated wetlands with nitrification pretreatment are viable treatment systems for removal of large quantities of nitrogen from swine lagoon liquid.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.22-30
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• 1999

This experiment was carried out to determine the forage yield and mineral contents of silage corn(Zea mays L.), and N balance, soil chemical characteristics and nitrate-N level in infiltration water by different types and N rates of liquid manure applied. Seven treatments consisting of chemical fertilizer $200kg\;N;ha^{-1}$, liquid cattle manure 200, 320 and $440kg\;N;ha^{-1}$, liquid swine manure 200, 320 and $440kg\;N;ha^{-1}$ were arranged in a randomized complete block design with three replications. The results obtained at National Livestock Research Institute, RDA, in Suweon from May 1997 to Aug. 1997 are summarized as follows : There were no significant differences in percentage of dry matter among the treatments, but significant dry matter yield differences were found (P<0.05), and also the mean dry matter yield of liquid swine manure plot was higher than that of liquid cattle manure plot. Potassium, calcium and magnesium contents of silage corn increased with increasing liquid manure application rates (P<0.05). Nitrate-N content of silage corn in the liquid cattle manure treatments was not influenced by liquid manure application rates, but that in the liquid swine manure treatments increased with increasing the N rates of liquid manure application. pH and contents of exchangeable canons of the soil after experiment were raised by increasing the amount of liquid manure application. Available $P_2O_5$ content in topsoil(0-10cm) was highest as $340mg\;kg^{-1}$ at the plot of liquid swine manure $440kg\;N;ha^{-1}$. Concentration of nitrate-N in infiltration water increased at the plot of liquid swine manure $440kg\;N;ha^{-1}$. Amount of nitrogen balance increased with increasing liquid manure application rates. Based on the results of this experiment, it is suggested that the mean dry matter yield of liquid swine manure plot was higher than that of liquid cattle manure plot, and the amount of nitrogen balance increased with increasing liquid manure application.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.234-240
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• 2015

In the face of the world's growing energy storage needs, liquid hydrogen offers a high energy density solution for the storage and transport of energy throughout society. A 5 L liquid hydrogen storage tank has been designed, fabricated and tested to investigate boil-off rate of liquid hydrogen. As the insulation plays a key role on the cryogenic vessels, various insulation methods have been employed. To reduce heat conduction loss, the epoxy resin-based insulation supports G-10 were used. To minimize radiation heat loss, vapor cooled radiation shield, multi-layer insulation, and high vacuum were adopted. Mass flow meter was used to measure boil-off rate of the 5 L cryogenic vessel. A series of performance tests were done for liquid nitrogen and liquid hydrogen to compare with design parameters, resulting in the boil-off rate of 1.7%/day for liquid nitrogen and 16.8%/day for liquid hydrogen at maximum.

• Journal of the Korean Geosynthetics Society
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• v.15 no.3
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• pp.57-66
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• 2016

In this study, to prevent possible collapse caused by hydraulic or mechanical instability, liquid nitrogen injection method is developed and implemented at the tip of drilling auger of steel pipe propulsion tunneling. In this study, 1/5-scale model auger and sand chamber were manufactured. The prototype diameter of steel pile (or casing) is assumed about 1,000 mm. For the frictional sandy soils and plastic weathered soils, liquid nitrogen injection methods were tested varying water contents of the soils. For the induced hydraulic instability, the ground near the drilling auger was frozen within approximately 5 minutes preventing mechanical collapse and water infiltration. Securing stability of steel pile propulsion tunneling using liquid nitrogen was much more effective for which the water content of the soil somewhat exceeds the optimum water content.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.5
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• pp.431-443
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• 2014

In this paper case studies of artificial ground freezing, which have not been applied in Korea, have been investigated for the water cut-off in a subsea tunnel under high water pressure and the most commonly used cooling mediums of brine and liquid nitrogen are examined. Since sea water with pressure has the lower freezing point than pure water, the lower temperature cooling medium is required in the application of subsea tunnel. Also, the cooling medium must have refrigeration safety and is able to reduce executing time. Brine freezing system can reuse cooling medium and is safer than liquid nitrogen freezing. But it takes more time to freeze ground and needs complex circulation plants. On the other hand, liquid nitrogen freezing system can't recycle cooling medium and may cause breathing problems or asphyxiation through oxygen deficiency. But, freezing with liquid nitrogen is fast and requires simple refrigeration equipment. Principal elements of design for ground freezing in subsea tunnel have been extracted and these elements are needed further research.

• Korean Journal of Plant Resources
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• v.14 no.3
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• pp.251-258
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• 2001

Predehydration effects for cryopreservation in -196$^{\circ}C$ liquid nitrogen were studied in Korean native Aquilegia buergeriana var. oxysepala Kitamura and A. flabellata var. pumila Kudo seeds. Aquilegia species seeds were adjusted to moisture contents between 3.2 and 9.7% by air dry treatments. Seeds were placed in paper envelopes after submerged in liquid nitrogen and rewarming in 38 $^{\circ}C$ water. Seeds moisture contents by duration of drying were identified as controlling factors in the survival of Aquilegia species seeds for cryopreservation. Aquilegia species seeds having approximate 5% moisture content were able to withstand cooling to -l96$^{\circ}C$. Undehydrated seeds of Aquilegia buergeriana var. oxysepala Kitamura after being cryopreservated in liquid nitrogen have a 10.9% of moisture content and show 52.5% in germination. But, Aquilegia buergeriana var. oxysepala Kitamura seeds dehydrated by drying for 60 min. to have 6.0% of moisture content before cryopreservation show 84.7% in germination test. Properly dehydrated seeds after being stored in liquid nitrogen showed over 60% in germination rate and also shows an uniform sprouting time,11~13 days in average. Any morphologically deformity in germinating beds has not been observed. Results from this study suggest that Aquilegia species seeds can cryopreservation in liquid nitrogen if the seed moisture content is controled by a proper amount of dehydration.

• Progress in Superconductivity and Cryogenics
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• v.8 no.2
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• pp.37-42
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• 2006

A research on several characteristics such as volume breakdown and surface discharge of insulators for a termination of power transmission class HTS cable was performed. We investigated the surface discharge of glass fiber reinforced plastic (GFRP) under air, cryogenic nitrogen gas and nitrogen gas media. The breakdown characteristics of these media were studied. Experimental results revealed that flashover voltage greatly depends on pressure, temperature, the kinds of insulating media and voltages, but it is slightly affected by shape and material of electrode. The breakdown voltage of liquid nitrogen, cryogenic nitrogen gas and nitrogen gas deeply depends on the shape and dimension of electrode, kinds of voltages and pressure. Moreover, the breakdown voltage of cryogenic nitrogen gas and flashover voltage of GFRP in the cryogenic nitrogen gas is also influenced by temperature and vapour-mist density of the gas.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.715-721
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• 2011

This study was conducted to estimate aboveground biomass and nitrogen storage potential of tree species-eight clones of a poplar and hybrids, one clone of Salix alba L., dawn redwood (Metasequoia glyptostroboides Hu and W.C. Cheng), yellow poplar (Liriodendron tulipifera L.), Okamoto maple (Acer okamotoanum Nakai), and pin oak (Quercus palustris $M{\ddot{u}}nchh.$)- after treating with liquid pig manure. Stems showed the highest percentage of aboveground biomass, and followed by branches and leaves. Nitrogen content in aboveground biomass components was the highest in leaves, and followed by branches and stems. Average aboveground biomass production was higher in the clones and species treated with manure than those of not treated, 30 ton/ha and 16 ton/ha, respectively. In the manure-treated site, clone 'Dorskamp' of Populus deltoides${\times}$Populus nigra showed the highest aboveground biomass (48.3 ton/ha). Average nitrogen storage potential was superior in the clones and species treated with manure than those of not treated, 159 kg/ha and 90 kg/ha, respectively. Clone 'Dorskamp' also showed the greatest nitrogen storage potential (286.5 kg/ha) among tested tree species. Therefore, 'Dorskamp' is the most suitable clone for treating liquid pig manure, but additional studies are needed to determine any damages or tolerance from the treatment.