• Journal of the Korean Geographical Society
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• v.30 no.3
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• pp.242-254
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• 1995

The Hadano Basin is located at a distance of about 70kms and 60kms from Tokyo and Yokohama and lies in the south-west part of the Kanto region in Japan. The basin area, which correspoends to the catchment of the Kaname River, is about areal size of 60.7$\textrm{km}^2$ and extends about length of 8kms in E-W direction and about width of 5kms in N-S direction (Fig.1). The Hadano basin is filled with thick pile of the alluvum from deposits composed of volcanic materials, mostly came from the Hakone Volcano and overlain by Fuji Volcanic ashes. Fluvial deposits form the good aquifer, therefore water resources of Handano City has been largely depending upon the eroundwater. Urbanization and industrialization of the basin has been rapid in the last thirty years, after activation of "Factory Attraction Policy of Hadano City" in 1956. Growth in population and number of factory due to urbanization changed the land-use pattern of the basin rapidly and increased the water demands. Therefore, Hadano City exploited a new source of water supply, and have introduced the prefectureal waterworks since 1976. On the other hand, the rapid urbanization has brought about the pollution of streams in the basin by domestic sewage and industrial waste water. Diffusion rate of sewerage systems in Hadano City is 38% in 1993. In ordcr to examine the impact of anthropogenic factors on river environments, the author took up the change of land-use and diffusion area of sewerage as parameters, and performed field surveys on water discharge and quality. The survey has been made at upstream and downstream of the main stream regularly per month, to get informati ons about the variation of discharge and water quality aiong the stream and its diurnal fluctuation. Annual variation has been analyzed based the data from Hadano City Office. The results are summarized as follows. 1. Stream discharge has been increasing by urbanization (Fig.3). Water quality (C $l^{-10}$ , N $H^{+}$$_{ 4}$-N, BOD) has been improving gradually after the application of sewerage service, yet water pollution load at the lower station has increased than that at the upper one because of the larger anthropogenic discharge volumes (Fig.4). 2. Corrclation coefficient of discharges between upper and lower was 0.81-0.92. Pollutant loads of the R. Kamame after the confluence with R. Kuzuha grew up by 2.4-3.7 times as compared with its upper reaches, and it increased to 3.7-6.9 times after the confluence with the R. Muro (Fig.5). 3. The changes of water quality along the stream can be divided into two groups (Fig.6a). First: water quality of the R. Kaname and R. Shijuhachisse is becoming worse towards the lower reaches because the water from branches are polluted. Second: water quality are improved in the lower where spring and small branch streams supply clear water, for example R. Mizunashi, R. Muro and R. Kuzuha. 4. Measured discharge at the upper station in the R. Shijuhachisse is 0.153㎥/sec, and about 55% of this is recharged until it reaches to the lower point. The R. Mizunashi has a discharge of 1.155㎥/sec at the upper point, is recharged 0.24㎥/sec until the midstream and groundwater spring 0.2㎥/sec at the lower reaches. R. Kuzuha recharged all the mountain runoff (0.2㎥/sec) at the upper reaches. The R. Muro is supplied by many springs and the estimated discharge of spring was 0.47㎥/sec (Fig.6b). 5. Diurmal variations in discharge and water quality are influenced clearly by domestic and industrial waste waters (Fig.7, 8).ed clearly by domestic and industrial waste waters (Fig.7, 8).

• Journal of the Korea Concrete Institute
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• v.21 no.2
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• pp.199-207
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• 2009

Many researches on electromagnetic (EM) properties like dielectric constant and conductivity are performed since they can be characterized in nonmetallic cement-based material such as mortar and concrete. However, they are much affected by the moisture so that the behaviors of EM properties are to be clearly understood. In this paper, measurements for saturation and EM properties are performed for cement mortar specimens with five different water to cement (W/C) ratios including basic tests like compressive strength and porosity measurement. Every saturated specimens are exposed to room condition and the changes in EM properties caused by decreasing saturation are analyzed. In the saturated condition, higher measurement of EM properties are evaluated in the specimens with higher porosity, however this relationship is adversely changed with drying process. Since the pores without filled water causes the decreases in EM properties, the measurements show stable and linear increment with the lower W/C ratios. Furthermore, the increasing ratios of EM measurements with W/C ratio are shown with saturation and the relationships between them are derived through regression analysis.

• Journal of the Korean earth science society
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• v.32 no.7
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• pp.809-831
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• 2011

Sea Surface Temperature (SST) is one of the most important oceanic variables to understand rapidly-changing climate, so that accurate and error-free SST images should be presented in school science textbooks. However, satelliteobserved SST images in the high-school textbooks presented some errors caused by various reasons. This study analyzed 36 satellite images for SST presented in 24 kinds of high-school textbooks (earth science I and II textbooks on the basis of the 7th National Curriculum) for 17 items. This study investigated errors in image processing such as cloud removal, land masking, color bar, geological and time information, and some erroneous expressions related to the fundamental information of satellites. Twenty five pre-service teachers filled out a survey about several problematic satellite images, and their responses were analyzed. As a result, most of the pre-service teachers did not recognize the errors associated with image processing and tended to comprehend the SST errors as real oceanographic phenomena such as sea ice, river outflow, or cold current. Therefore, satellite SST images in the textbooks should be accurately presented by including detailed items suggested in this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.190-194
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• 2000

Double cropping is important for increase of farm income and rate of arable land utilization. This study was carried out to obtain information for optimum plant density of the second crop in a double cropping system. A waxy corn hybrid, Chalok #2, was sown on July 10 at the first corn cropping site. Growth characteristics and yield response of fresh waxy corn were examined under different planting densities, which were 55.5, 66.6, 83.3, and 111.1 thousands plants ${ha}^{-1}$. Plant height was higher under high planting density than low planting density and 154cm at the 55.5 thousand plants ${ha}^{-1}$, and 168cm at the 111.1 thousand plant ${ha}^{-1}$. It showed same trends in ear height and gravity center height. But planting density did not affect root lodging and silking date. At the silking stage, stalk and leaf dry matter weight and leaf area index (LAI) were increased significantly with increasing planting density, Filled ear lengtg was shortened significantly under the hi임est planting density (111.1 thousand plants ${ha}^{-1}$), while ear length and ear diameter were no differences among planting densities. The number of marketable ears increased with increasing planting density, but husked fresh ear weight was the highest at 83.3 thousand plants ${ha}^{-1}$ with 11.2MT ${ha}^{-1}$and optimum planting density was estimated as about 80 thousand plants ${ha}^{-1}$.

• Resources Recycling
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• v.24 no.1
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• pp.58-65
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• 2015

Although Korea is a top market sharing and world leading producer and developer of flat panel display devices, relevant recycling technology is not up to her prestigious status. Besides, most of the waste glass arising from flat panel displays is currently land-filled. The present paper mainly reviews on development of recycling systems for waste TFT-LCD glass from end-of-life LCD TVs and monitors and TFT-LCD process waste of crushed glass particles with target end uses of raw material for high strength concrete pile and glass fibers, respectively. Waste LCD glass was recycled to fabricate ingredients for high strength concrete piles with enhanced physical properties and spherical foam products. The waste LCD glass recycling technology is already developed to fabricate long and short fibers at commercial level. In view of these, future R & D on waste LCD glass materials is to be directed toward implementation of commercial materials recycling system therefrom.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.291-297
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• 2018

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.23-31
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• 1987

In land treatment systems for organic waste removal, especially rapid intiltration method is well known as less climatic restrictions and less field area requirements as against the others. Therefore the present study on rapid infiltration is aimed to survey the waste removal rate, infiltration rate, variation of dissolved oxygen due to biological oxygen absorption and pH decrement using pilot infiltration column filled with permeable soil(sand) as media, also to find the waste load(COD) per unit area and nitrate conversion ratio from TKN. The results obtained here are as follows. 1) When the depth of sand layer is more than 1 meter, the COD removal would be reached steadly to 90% or more under the infiltration rate below 15~20cm/day, and would be no problem due to leached organic pollutants considering the depth of ground water table. 2) The COD removal per unit area($m^2$) can readily be expected to 10~14g/day with proper operation, and the decomposition of substrate would be attained mostly at the surface layer of the media. 3) Generally the conversion of TKN to the $NO_3{^-}$-N is seemed to be proportional to the COD removal rate if provided proper retention time.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.133-144
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• 2001

An effective seismic reflection technique for mapping the cavities and bedrock surface in carbonate rocks is described. The high resolution seismic reflection images were successfully registered by using the hydrophones employed in the stream-water driven trench, and were effectively focused by applying optimal data processing sequences. The strategy included enhancement of the signal interfered with the large-amplitude scattering noise, through pre- and post stack processing such as time-variant filtering, bad-trace editing, residual statics, velocity analysis, and careful muting after NMO (normal moveout) correction. The major reflections including the bedrock surface were mapped with the desired resolution and were correlated to the seismic crosshole tomographic data. Shallow major reflectors could be identified and analyzed on the AGC (auto gain control)-applied field records. Three subhorizontal layers were identified with their distinct velocities; overburden (<3000 m/s), sediments (3000-4000 m/s), limestone bedrock (>4000 m/s). Taking into account of no diffraction effects in the field records, gravel-rich overburdens and sediments are considered to be well sorted. Based on the images mapped consistently on the whole survey line and seismic velocity increasing with depth, this area probably lacks in sizable cavities (if any, no air-filled cavities).

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.245-253
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• 1995

The effects of a simultaneous application of KCl and lime on the root uptake of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ by rice, soybean, Chinese cabbage and radish were investigated through 2 years' greenhouse experiments. At their early growth stages, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm and $83g/m^2$ of fertilizer KCl and $200g/m^2$ of slake lime were applied to the surfaces. Distribution of radioactivities among plant parts and change in uptake pattern with plant species were not, on the whole, significantly affected by the application. It reduced effectively soil-to-plant transfer factors of $^{85}Sr\;and\;^{137}Cs$ for rice, of all for Chinese cabbage and of $^{54}Mn,\;^{60}Co,\;and\;^{137}Cs$ for radish without their growth inhibition. In rice, $^{85}Sr$ showed the highest decrease $({\sim}60%)$ while, in Chinese cabbage and radish, $^{54}Mn$ did $({\sim}80%)$. The exprimental results can become valuable reference data to establish countermeasures against a radioactive contamination of farm-land during plant growth.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.125-133
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• 2009

Wastewater sludge had normally filled up in land before revising the law of waste material management in 2003, which does not permit landfill of organic sludge in Korea. After the law, most sludge has been littered in the ocean up to now. However, due to the London Convention 96 Protocol, littering sludge in the ocean will also be prohibited after 2011. This Protocol makes countries find out new methods to treat wastewater sludge. There is no exception in Korea too. Many researchers have urgently try to find out better ways to treat sludge. One of ways is to make sludge recycle energy and the success of it depends on drying method. Specifically, it really depends how to make sludge dry ecologic friendly and economic efficiently. Therefore, wastewater sludge produced in Youngdong was analyzed to make it energy resources in this study. The sludge was tested to analyze the drying and chemical characteristics of it by irradiating microwave. In the result, it is sure that the sludge has little heavy metals as like as others in country side. High calories, 3370 Kcal, shows that it has good potential to be recycle energy. Moreover, weight deduction of the sludge vs. time shows long S-curve and has same deduction ratio. Specifically, S-curve can be divided by three sections based on the curvature points. There are steady state reduction ratio of weight and approximately 80% of weight duction in the second section. This results can be used to estimate the amount of sludge reduction in the full-scale microwave dryer. Drying capacity of microwave shows approximately 1.0 kg/kw/hr. It makes sure that sludge recycle energy has the potential of economic efficiency too.