• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.112-127
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• 1997

The purpose of this study is to get optimum operating factors of Upflow Anaerobic Sludge Blanket (UASB) reactor by introducing methods that make it to reduce inhibition possible in each process wastewater treatment. The used substrates, concentrated corn starch liquid (CSL) wastewater, modified starch, filtering and decoloring wastewater, ion refining wastewater, and mixed wastewater including modified starch and not including modified starch, are generated from molasses process. The seeding sludge is the digested sludge that had been applied to molasses wastewater. Batch test to reduce the inhibition factors that might be existed in each wastewater was examined. Based on the this test, the optimum operating factors according to alkalinity and pH variation was studied through the continuous test using three 5.5 L UASB reactor. The first reactor added $NaHCO_3$ to control alkalinity. The hydraulic retention time (HRT) reduced to 8 hours and the organic loading rate increased gradually. The second reactor changed the pH of influent from 7.0 to 6.0 using NaOH. The third reactor was operated without changes to compare the above two reactors. As the result, the inhibition in concentrated CSL wastewater was removed by adding iron (II). When trace metals were added to mixed wastewater not including modified starch, the digestability by gas production rate increased to more fifty percentage than mixed wastewater that was not adding the trace metals. The reason that the inhibition did not decreased in spite of adding trace metals and nutrients was influenced by high concentration generated during the acid fermentation. The UASB reactors using the mixed wastewater with the most effective performance were operated as 500 mg/L as $CaCO_3$ alkalinity and 6.0 pH at steady state, and at this time, the gas production rates were 283 and 311mL gas/g $COD_{added}$. The COD removal rates were 84.7 and 86.3%, respectively.

• Journal of Environmental Health Sciences
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• v.28 no.5
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• pp.22-27
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• 2002

The composting practice has been recognized as the most popular way of controlling food waste and many attempt have been made in the field to establish more efficient and economical process. Some of the efforts are mixing cured compost with sawdust as alternative bulking agent, seeding commercially produced microorganism and/or combination of above. However, verification of such efforts is often restricted because of either the lack of engineering consideration on the limitation of composting facility scales. In this study, the effect of mixing materials in food waste composting was investigated by controlling the combination and the mixing ratio of them. When the cured compost was mixed with saw dust. the decomposition of organic material was proven to be more active by observing the compost temperature, the oxygen (O$_2$) consumption, and the cumulative carbon dioxide ($CO_2$) profile. However, the quantity of compost mix-ing seemed not to influence the reaction as long as the minimum required amount was mixed. The feeding of com-mercially produced microorganism had a tendency to prolong the thermophilic stage, which helped to increase the decomposition but it resulted in composting period. Regardless of the composting condition, bacteria and actinomycetes increased in population as the reaction approached to the end. The population of bacteria and actinomycetes were rel-atively higher than those of fungi and yeast throughout the reaction.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.49-57
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• 1993

Seedling of Aralia continentalis is more effective method rather than use of vegetative organ for mass propagation. However, lower germination rate is the main problem for seeding. In this study, we analyzed substances in aim to relate to germination process. The results indicated that longer period of stratification brought lower amount of phenolic compounds in the seeds and both promoting and inhibiting substances were at very low level or gradually disappeared.

• Korean Journal of Organic Agriculture
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• v.11 no.3
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• pp.91-108
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• 2003

So far, we have pursued only convenient and efficient growth of economy, as a result, environment surrounding us has been destroyed and the rights of our existence gotten to be even threatened. We need to ensure our lives and at the same time, need a power with which agriculture undertakes global circulation structure and a power that is able to preserve our environment we live per so. Therefore, in the near future, the final objectives of agriculture structure for 21st century would be to increase productivity of highly developed agricultural products in accordance with the ecosystem and a recycling agriculture. What is a recycling agriculture\ulcorner In the narrow sense, it means provisions-producing- system related to interactive recycle of material among forestry, livestock husbandry and seeding agriculture. In the broad sense, it means to produce credible agricultural product by keeping balanced resources via conversion to complete degradable material of organic wastes produce within rural village. Based on this concept, finally, our goal is to construct the resources recycling community. Environment friendly agriculture ⇒ organic agriculture ⇒ recycling (circulation) agriculture ⇒ construction of community with resources recycling. Therefore, in order to construct recycling agriculture, most of all, it is considered that the following, it should be established reasonable standard amounts for fertilizer, manure and liquid fertilizer based on results of soil test by each region, nature-recycling form of crops production and livestock production systems by maximizing utilization of different recycling byproducts occurring in the crop producing process by each region.

• Journal of Ecology and Environment
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• v.33 no.3
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• pp.187-193
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• 2010

Seed germination is a biological process that is affected by a variety of genetic and environmental factors. The cardinal temperature and thermal time are required for germination. The principal objective of this study was to identify and characterize variations in the base, optimum, and maximum germination temperatures of Haloxylon aphyllum L. from two seed sources, in order to establish models for use in predicting seeding dates. Mature H. aphyllum seeds were germinated at temperatures between 5 and $35^{\circ}C$. The germination behavior of H. aphyllum seeds to different temperature regimens in light was evaluated over a temperature range of $5-35^{\circ}C$ at intervals of $5^{\circ}C$. The rate of germination increased between base and optimum thermal conditions, and decreased between optimum and maximum thermal conditions; the germination rate varied in a linear fashion at both sub-optimal and supra-optimal temperatures. The linear regression fit the range of germination rates at $5^{\circ}C$ to $25^{\circ}C$ and $25^{\circ}C$ to $30^{\circ}C$, and thus the base temperature, optimum temperature, and maximum temperature for the germination of H. aphyllum were measured to be $0.6^{\circ}C$, $25.69^{\circ}C$, $37.90^{\circ}C$, and $1.76^{\circ}C$, $21.56^{\circ}C$, $37.90^{\circ}C$ for Qom and the Fars dune desert respectively.

• Journal of Biosystems Engineering
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• v.28 no.2
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• pp.107-116
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• 2003

One of the major obstructing factors against managing dairy farm in Korea has been a shortage of roughage supply. The shortage of roughage caused excessive use of concentrate feed increase of production cost and deterioration of cattle quality. In order to solve this problem for the dairy farm, use of fallow paddy field in the winter was feasible to produce barley and rye forage during the winter season after harvesting of in. And many desirable effects of raising cattle productivity, saving dollars for importing feeds and providing huge ground for manure spreading are expected by enlarged local roughage production. Through analysing the forage producing process, a mechanized operation model was developed for dairy farms in Korea. Its model consists of seeding models(till, no-till model) and harvesting models(wrap silage, traditional silage, hay model). Currently, the government policies are being executed to urge producing winter cereal wrap silage in the fallow paddy field with various supporting programs. Ant with enlarged local forage production, it is possible to make a new huge market fur forage producing machine.

• Journal of the Korean Society of Visualization
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• v.3 no.1
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• pp.20-25
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• 2005

An x-ray PIV (Particle Image Velocimetry) technique was developed fur measuring quantitative information on flows inside opaque conduits and/or opaque-fluid flows. To check the performance of the x-ray PIV technique developed, it was applied to a liquid flow in an opaque Teflon tube. To acquire x-ray images suitable for PIV velocity field measurements, the refraction-based edge enhancement mechanism was employed with seeding detectable tracer particles. The amassed velocity field data obtained were in a reasonable agreement with the theoretical prediction. The x-ray PIV technique was also applied to get velocity fields of blood flow and to measure size and velocity of micro-bubbles simultaneously, and to visualize the water refilling process in bamboo leaves. The x-ray PIV was found to be a powerful transmission-type flow imaging technique fur measuring quantitative information of flows inside opaque objects and various opaque-fluid flows.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.920-932
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• 1994

The combustion phenomena of a reciprocating engine is one of the most important processes affecting performance and emissions. One effective way to improve the engine combustion is to control the motion of the charge inside a cylinder by means of optimum induction system design, because the flame speed is mainly determined by the turbulence at compression(TDC) process in S.I. engine. It is believed that the tumble and swirl motion generated during intake breaks down into small-scale turbulence in the compression stroke of the cycle. However, the exact nature of their relationship is not well known. This paper describes cycle resolved LDV measurement of turbulent flow inside the cylinder of a 4-valve engine under motoring(non-firing) conditions, and studies the effect of intake port configurations on the turbulence characteristics using following parameters ; Eulerian temporal autocorrelation coefficient, turbulence energy spectral density function, Taylor micro time scale, integral time scale, and integral length scale.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.3
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• pp.293-298
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• 1986

The physiological aspects of tobacco seeds from seeding to germination under light and dark condition, and different temperature were studied to obtain basic information on the production of good seedlings. There were distinct three phases in moisture uptake and respiration process during germination that classifiable into 'Imbibition', 'Lag', and 'Growth' phase under light condition but such growth phase were not observed in the dark germination. Great changes of sugar and fatty acid content of tobacco seeds were observed during germination in light condition but such changes were slight in dark germinated seeds and fatty acid content of seeds during germination were decreased as corresponding to increasing in respiration.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.293-297
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• 2000

Multiseeding with (100)/(100) grain junctions of top-seeded melt growth (TSMG) processed YBCO superconductors was studied. The effect of the number of seeds and the distance between two seeds on the levitation forces and the trapped magnetic fields of the TSMG-processed YBCO samples was investigated. Multiple seeding shortened the processing time for the fabrication of TSMC-processed YBCO superconductors. The large magnetic field was trapped at the grain junction when two seeds was placed without spacing, while the amount of the magnetic field decreased when the seed distance increased. This is attributed to the increased amount of the residual melt phases around the grain junctions.