• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.2
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• pp.2593-2602
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• 1972

Plastic pipes Wrapped with synthetic filter are recently used for drainage or Collecting of Underground water. But it's use is possible only for small size of diameter less than 300mm, because large size plastic pipes are not readily availabe. For large diameter infiltration gallery, porous concrete pipes are now used, but it's heavy weight brings difficulties in making, moving and setting of the pipes. With it's conventional method of filter setting, fine sands are brought into the pipes to make trouble to lifting pumps and channels Therefore, initial construction cost and maintenance cost become high. To solve-this problem, new method is developed and tested. Small PVC pipes(diameter 14mm) are assembled at the site of construction to newly devised I beam type circls. The size of circular inpiltration gallery is optionally determined by I beam type circle which support small PVC pipes and is made of PVC amterial. This gallery are wrappd with syntheitc filter to prevent sand instruction. In this test, the diameter of 300, 400, 500mm were used. I beam type circles were made with PVC plated with thickness. t=6, 9, 12mm. Water quantity collected through the PVC circulor gallery are measured and the strengths of the gallery. 1. Allowable setting depth of gallery pipe below graund for the case of t=6mm, D=500mm is 2.72m. 2. Collected water quantity depends on soil texture, depth of water grandient of water surface, filter material angle of setting etc. 3. About 126% of water quantity collected from the one gallery pipe measured in two gallery pipes of two parallel installation.

• The Korean Journal of Malacology
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• v.9 no.2
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• pp.16-22
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• 1993

Contamination of heavy metals in water and sediments along Mangyeong Gang(river) has reached up to critical level The object of the study is to elucidate somed molluscs which inhabit along the river on respect to the modulatory role in reducing the pollution. For the purpose, molluscs which are common in numbers and biomass in the area were collected, and Cadmim(Cd) was subjected as a reference metal in the experiment. The corresponding species were; Cipango;aludina chinensis (muddy snail) and Scapharca subcrenata (seashell). As methods, sample species were kept in laboratory under the natural condition as possible. Soil were brought from the site of the collection, dried autoclaved and wetted with ordinary water. It wad utilized as media to maintain the collected species in vitro all the way of the experiment. CdCI$^{2}$ was mixe in the medium according to experimental design. On the result obtained in the study, it is summarized that molluscs which inhabit along Mangyeong Gang(river)consume heavy mital-containing matters, so far Cd is concerned in the study. The amout of Cd concentration in tissues of the benthic natured invertebrates were dose and time related, and MT-Cd was also similar trend. Thus, Cd may eventually combine with low molecular protein forming metalloprotein, then reduce the toxicity of the heavy metal.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.3
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• pp.115-127
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• 1997

Nonpoint source (NPS) pollution from small watersheds has recently been brought into attention as a potential pollutant to streams and tnbutaries, as majority of them are experiencing water quality degradation. This necessiates the quantification of NPS loadings from agricultural and forested lands. And this study attempts to quantify daily loadings from forested and farm lands using hydrologic and water quality monitoring. The hydrologic monitoring program consists of five water level gauging stations along creeks and stream at the Banweol reservoir watershed having 1220 hectare in size. Water sam pies were taken and analyzeel periodically at the streamf low gaging sites and tributaries. Soil samples were also taken and the chemical constitutes analyzed. The primary results indicate that the major sources of pollution were small villages and dairy farms on the watersheds, constituting two-third of total nutrient loadings to the reservoir. However, the loadings from paddies and upland areas may cause a problem to the water quality of the reservoir and stream as the measured levels of total nitrogen and phosporus are not low enough to ignore. Further studies are needed to quantify the effects of landuses and treatments at a watershed scale.

• Structural Engineering and Mechanics
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• v.8 no.1
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• pp.39-51
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• 1999

The dynamic response of buried pipelines has gained considerable importance because these pipelines perform vital role in conducting energy, water, communication and transportation. After realizing the magnitude of damage, and hence, the human uncomfort and the economical losses, researchers have paid sincere attention to this problem. A number of papers have appeared in the past which discuss the different aspects of the problem. This paper presents a theoretical analysis of non-axisymmetric dynamic response of buried orthotropic cylindrical shell subjected to a moving load along the axis of the shell. The orthotropic shell has been buried in a homogeneous, isotropic and elastic medium of infinite extent. A thick shell theory including the effects of rotary inertia and shear deformation has been used. A perfect bond between the shell and the surrounding medium has been assumed. Results have been obtained for very hard (rocky), medium hard and soft soil surrounding the shell. The effects of shell orthotropy have been brought out by varying the non-dimensional orthotropic parameters over a long range. Under these conditions the shell response is studied in axisymmetric mode as well as in the flexural mode. It is observed that the shell response is significantly affected by change in orthotropic parameters and also due to change of response mode. It is observed that axial deformation is large in axisymmetric mode as compared to that in flexural mode.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.1
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• pp.1-10
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• 2001

Since the Industrial Revolution, people have enjoyed an abundant life, owing to the technological innovations of science. However, because of changes in the environment or polution to the environment, it has brought on many chronic diseases. Especially, even though it may be a small amount, if cadmium gets into a human body, because its biological half life is long, it fatally causes a kidney disease and damage to human organisms. It was reported that Metallothioneins(MT), a substance that is closely related with a free radical that comes from environmental pollution and the course of which cadmium, which causes chronic addition in the body, is formed, along with harmful metals, make the toxicity reduce. MT compound led into the body by cadmium indirectly functions as an antioxidation, supplied adequate amount of vitamin E, and suppresses the accumulation of cadmium in heart, liver and blood. Cadmium content found in Korean soil according to the test conducted from 1992 to 1996 was 0.02~0.03mg/kg in cereals, pulses, and potatoes. Free radical scavenger, finding solution for metal substance that comes from environmental pollution from food and natural substances implicates a better future for the study of food science.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.78-83
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• 2013

The excessive and indiscriminate use of chemical fertilizers in the past has brought serious soil and other environmental problems so alternatives over this agrochemical are being searched. Our study focuses on the effects of expanded rice hull inoculated with selected beneficial microorganisms on growth (through agronomic characters), yield and yield components, and grain quality indices of rice. Results showed that favorable effects of different expanded rice hull preparations were not readily apparent at vegetative stage and only treatments with supplemental chemical fertilizer application were comparable with the conventional practice. Expanded rice hull combined with 50% rate of chemical fertilizer exhibited a significantly higher yield (6,471 kg $ha^{-1}$) over conventional practice (5,719 kg $ha^{-1}$). Good milling quality indices were observed in treatments having 50% chemical fertilizers plus alternatives from expanded rice hull. Finally, we demonstrated that chemical fertilizer rate can potentially be reduced into 50% if combined with expanded rice hull, and show even better output than chemical fertilizer alone.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.242-252
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• 1984

A port experiment was conducted to compare the effect of chemical forms of nitrogen fertilizers on the rice growth and soil characteristics. The nitrogen fertilizers used for this study were ammonium sulfate, ammonium nitrate, ammonium chloride and urea. The results are summarized as follows. 1. The differences in pH of the soil and surface water between treatments during the first week after fertilizer application were great and the pH values were in the order of urea > ammonium nitrate > ammonium sulfate > ammonium chloride treatment. However the differences were insignificant after the first week. 2. The differences in pH of the air-dried soil somewhat increased and pH values were in the order of urea > ammonium nitrate > ammonium chloride > ammonium sulfate treatment. 3. Sulfur contents of the soil and the rice leaf and N content of the rice leaf were highest when ammonium sulfate was applied. But there were few differences between the treatments in total N content of the soil and in P, K, Ca and Mg contents of the soil and the rice leaf. 4. Number of tillers and dry matter weight of the rice plant were highest in ammonium sulfate plot throughout all the growing stages. 5. Number of panicle per hill was highest in ammonium sulfate plot, and this brought the highest grain yield in ammonium sulfate plot. The lowest grain yield in ammonium nitrate plot resulted from the lowest number of panicle per hill and ripened grain ratio.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.272-279
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• 1994

In order to compare the biological properties of benfuresate and cinosulfuron as herbicides for the chemical control of Eleocharis kuroguwai, some experiments were conducted at greenhouse and field conditions in 1993. Benfuresate and cinosufuron moved to 2cm and 6cm deep in paddy soil and inhibited the growth of E. kuroguwai. Benfuresate was absorbed into the roots of E. kuroguwai. whereas cinosulfuron was absorbed into not only the roots and shoots but also the mesocotyls. After the emergence was inhibited by the soil application of herbicides, the percentage of regrowing numbers was higher at cinosulfuron than at benfuresate, whereas the growth rate was higher at benfuresate on the contrary. Benfuresate brought about complete death of buds as a killing type, but cinosulfuron produced lots of abnormal shoots as an inhibiting type. Benfuresate was able to apply on soil surface from the preemergence to the early stage of 2cm high, but cinosulfuron was able to use from the preemergence to the stage of 15cm high. The foliar application of cinosulfuron showed a good control effect, but it induced a severe phytotoxicity to rice. A good control effect of Benfuresate/bensulfuron GR lowered at the late stage, but that of cinosulfuron/mefenacet/dymron GR at the early stage maintained until the late stage of 65 days after transplanting.

• Korean Journal of Pharmacognosy
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• v.9 no.3
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• pp.149-156
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• 1978

The result of the study about the cultivation, the constituents, the sweetenity, and the development of preparations of Stevia and Hydrangea are as follows: 1. Hydrangea thrived at $200{\sim}1,400m$ above the sea-level, and the good ones were brought up at $600{\sim}1,200m$. 2. The good ones which belonged to the genera of Hydrangea were produced in the damp, dark and cold place. 3. The growth and cultivated yield of Stevia was not significantly influenced by the acidity of the soil. 4. The best season was May and June for propagation of Stevia by cutting method. 5. The growth rate of Stevia and Hydrangea was really good in the sandy fertile soil, but in the mucotic soil it was not suitable. 6. The extraction and separation of phyllodulcin by solvent had many difficulties, because it was very soluble in water, ethanol, ether, petroleum ether, acetone and benzene, etc. 7. The solubility of stevioside on the solvent was as follows: It was very soluble in water and methanol, slightly soluble in ethanol and acetone, and insoluble in ether, petroleum ether and chloroform. 8. The alkaloid reaction by Mayer reagent in Hydrangea extract was positive. 9. The ashification rate of Stevia was 8.66% to 8.72% and that of Hydrangea 17.02% to 17.04%. 10. The tannin of Stevia leaf was 7.80% to 7.88% and its of Hydrangea decreased 9.46% to 6.08% by fermentation. 11. The percent rates in minimum concentration-occurring sweetness in sugar, glycyrrhiza methanol extract, Hydrangea water extract, Stevia leaf water extract, decoction of Stevia's leaf, decoction of Stevia's stem were as follows: 1.2, 0.1, 0.1, 0.2, 0.4, 0.01, 0.1, 0.6. and sweetenity ratios of those were 1, 12, 12, 6, 3, 64, 12, 2, 12. It was very meaningful to develop preparations of stevia as stevioside, micronized powder, water extract, methanol extract and compound teas and in Hydrangea, water extract, methanol extract, single tea, and compound teas were less meaningful. 13. The genera of Hydrangea which is natural species in Korea was positive in phyllodulcin-identification test, but it was not available to make the sweet tea because of having a little content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.209-215
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• 1992

Different from 'Seyokwiryang' (歲易爲良 : fallowing as the best method) which was an agricultural technique of ancient China, fertilization of rice fields was already practiced in the end of Koryo age in Korea. 'Bunjongbeob'(糞種法 : fertilizer applicating method on seed) or 'Bunkwabeob' (糞科法 : fertilizer applicating method on each plant) was practiced before green manure of bean crops and 'Bunjeonbeob'(糞田法 : fertilizer practicing method on fields) were done. In the 15th century 'Dojeonbunjeonbeob'(稻田糞田法 : fertilizer applicating method on paddy) in 'Jikseol' was divided the materials to be used into the soil brought from another place, trees, grasses, and the manure. Also, it discribed the fertilization between first plowing and the second, and proper fertilization for particular soil conditions. In case of transplanting techniques, the fertilization practices were specified into nursery and rice fields, and restoration of organic matter was systemized by plowing for cultivation in the reclaimed areas. In the 17th century, through 'Jikseolbo'($\ulcorner$直說補$\lrcorner$), the habitual practice of Kyungsang province was systemized and 'Bunyangsool'(糞壤術 : technique of fertilization) of 'Jodoangkicheo' (早稻秧基處 : rearing fields of early-ripening rice) was completed. Specific things was the manufacturing and utilizing techniques of 'Bunhoe'(糞灰 : mixture of manure and ash), 'Yohoe'(尿灰 : mixture of urine and ash), and additional fertilizers. In the 18 to 19th century, the materials of fertilization were greatly enlarged to recover the waste lands and to support the reinforcement of soil fertility for increasing the system of two cropping a year. Also, 'Jeobunbeob'(貯糞法 : method of manure storage) and additional fertilization were emphasized, and use of wagons for it was emphasized to improve the theory of fertilization and working efficiency. As mentioned above, limitation of fertilizing materials was conquered by 'Dojeonbunyang'(稻田糞壤 : techniques of practicing fertilizers in paddy) and the system of additional fertilization was established. The fertilization methods were improved with 'Jeobunbeob' due to the theory and recognition necessary for high rates of fertilizers.