• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.180-185
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• 2003

The increase of traffic over a bridge has been emerged as one of the most severe problems in view of bridge maintenance, since the load effect caused by the vehicle passage over the bridge has brought out a long-term damage to bridge structure, and it is nearly impossible to maintain operational serviceability of bridge to user's satisfactory level without any concern on bridge maintenance at the phase of completion. Moreover, bridge maintenance operation should be performed by regular inspection over the bridge to prevent structural malfunction or unexpected accidents front breaking out by monitoring on cracks or deformations during service. Therefore, technical breakthrough related to this uninterested field of bridge maintenance leading the public to the turning point of recognition is desperately needed. This study has the aim of development on automated inspection system to lower surface of bridge superstructures to replace the conventional system of bridge inspection with the naked eye, where the monitoring staff is directly on board to refractive or other type of maintenance .vehicles, with which it is expected that we can solve the problems essentially where the results of inspection are varied to change with subjective manlier from monitoring staff, increase stabilities in safety during the inspection, and make contribution to construct data base by providing objective and quantitative data and materials through image processing method over data captured by cameras. By this system it is also expected that objective estimation over the right time of maintenance and reinforcement work will lead enormous decrease in maintenance cost.

• The Korean Journal of Mycology
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• v.16 no.1
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• pp.1-8
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• 1988

Effect of suppression for zoosporangial germination and mycelial growth of Phyto­phthora capsici causing red pepper fruit rot, was carried out in vitro test by using $NH_4OH$ and $KNO_2$, as ammonium/ammonia, nitrite/nitrous acid and $CaCl_2$, as calcium ion. Results of in vitro tests with $NH_4OH$, $KNO_2$, and $CaCl_2$, mol solutions demonstrated that zoosporangial germination of P. capsici was inhibited about 15 to 50% compared with control, according to $NH_3$, HNO as nonionized form and $Ca^{+2}$ ions. Ammonia concentration$(NH_3)$ was proportionally increased by high pH level and mol concentration, whereas low pH and high mol concentration showed rather higher concentration of $HNO_2$. Ammonia were more toxic at pH 8 than at pH 7 under the same concentration, while nitrous acid$(HNO_2)$ was more toxic than at pH 8. The zoosporangial germination inhibition in the ammonium/ammonia and nitrite/nitrous acid solutions demonstrated that $NN_3$, and $HNO_2$, were primarily responsible for the inhibition at lower concentration and mor" toxic by increasing concentration. $Ca^{+2}$ ions showed that zoosporangial germination was inhibitory by high pH level and increasing mol concentration in comparison with buffer conlrol. pH levels affected to mycelial growth of the fungus, and especially, high pH caused rather retardation of mycelial growth. There was no definite inhibitory response of mycelial growth at various degree concentrations of the toxicant solutions.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.99-105
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• 1976

After investigation of soil characteristics the properties of a reclaimed marine soil (Gupo series) distributed along the southern coastal areas of Korea are summarized as follows: 1. Gupo soils distributed in the southern Ria coastal area are derived from rolling to hilly materials and are poorly sorted with less influences of river fluvial action. These soils have high content of sand compared with the broad fluvio-marine soils in the western coastal areas. 2. The morphological features of the poorly drained Gupo soils are greyish brown sandy loam with a few yellowish mottles in the surface horizon and are grey sandy loam with a few gravel in the sub-strata. The ground water table remains around 10-30cm below the surface. These soils, recently reclaimed younger deposits, do not show any evidence of illuviation. 3. The "n" value (about 0.8) of the Gupo soils indicates physically unripened soils. 4. pH value of these soils shows more than 8.0 throughout the profile. Organic matter contents are extremely low (around 0.5%) except 1.2 percent in the surface horizon. C.E.C. ranges from 7 to 9m.e/100g which is lower than average in the country. The ratios of extractable cations such as Ca, Mg, Na and K of the surface horizon are 20:7:4:1. Base saturation is more than 60%. Available phosphate content is very low that is less than 25 ppm. Electric conductivity of the soils at $25^{\circ}C$ ranges 7 to 12 mmhos/cm and increased with depth. 5. According to classification of soil based on physical ripening, the Gupo soils can be classified into "Unripe soils with half-ripe sub-soils". The soils could be classified into "Hydric Haplaquents" in the original of the 7th Approximation (1960), but into "Typic Haplaqents in the supplement of 7th approximation which the physical ripening condition is not clearly expressed. Soil Taxonomy, apparently the final version of the 7th approximation, defines the soils as "Haplic Hydraquents" that clearly show the condition of physical ripening as well as other properties. Other several classification systems applied do not describe physical ripening condition of the soils.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.4
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• pp.227-234
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• 1974

A survey on the vinyl house soils was conducted to investigate the salt accumulation status and it's effects on the deterioration of soil aggregates. The survey was made for the vinyl house soils in Suwon, Yesan, and Kimhae areas where vegetables are extensively grown under a vinyl house. Physical and chemical properties of the soils at the inside and outside of the vinyl house were compared to continuous vegetable cropping. Electrical conductivity of the soil solution (Y) in vinyl house was closely related to the number of cropping years (X), and the relations are given by the following regression equations: $Y=0.54X{\times}1.44$ ($r=0.580^*$) for loamy textured soils and $Y=0.58X{\times}2.61$ ($r=0.524^*$) for clayey textured soils. Electrical conductivity of the soils, where vegetable cropping in winter and rice in summer were rotated, was lower than that given by the regression equations. Analyses for extractable cations, the concentration of calcium, sodium and potassium was high in the inside vinyl house soils compared to the outside. Soil aggregates larger than 1mm in diameter were greatly deteriorated, while the content of the soil aggregates smaller than 0.5mm in diameter remained unchanged. Aggregate stability of the soil was negatively correlated to the accumulation rate of extractable sodium ($r=-0.681^{**}$), potassium ($r=-0.528^*$) and the amount of daily irrigated water (r=-0.477), while positively correlated to the content of organic matter ($r=-0.692^{**}$) and calcium (r=0.391).

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.287-292
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• 1990

A study has been conducted since 1954 to elucidate the effects of longterm application of ammonium sulfate (AS), urea, compost, and calcium silicate(CS) fertilizers on major soil nutrients and rice yields in wetland soil. The soil pH in the AS plot become lower than that in the urea plot but had little influence on rice yield. Continuous application of AS and urea with compost and CS raised the soil pH compared with single applications of AS or urea. Soil organic matter content increased yearly in plot with no fertilizer and in those with AS and urea, and increased considerably in plots with compost and CS. Application of compost and CS promoted rice top growth as well as root growth, resulting in increased dry matter. Soil contents of N, $P_2O_5$, Ca, Mg, and $SiO_2$ in the NPK with composts plot increased considerably compared with the NPK plot; however. the exchangeable K content was rather low. Rice growth increased with compost application. which enhanced K uptake, and the coarse texture promoted K leaching. With compost and CS addition, con tents of exchangeable Ca and Mg in the AS plot decreased considerably more than in the urea plot. Probably this was the result of higher Ca and Mg precipitation by sulfate in the AS plot. The re are no significant differences in rice yield between AS and urea plots. With compost and CS treatments, rice yields increased in the AS plot compared with the urea plot. The increase in yield is considered to be the effect of S. which is a constituent of AS.

• Journal of Applied Biological Chemistry
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• v.56 no.4
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• pp.229-234
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• 2013

Coal ash can be added to agricultural soils to increase the chemical properties of soil such as pH, cation exchange capacity and nutrient availability of - B, Ca, Mo etc-. Therefore, the main purpose of this study was to evaluate the feasibility of fly ash as a soil amendment in paddy soils. Selected fly ash was mixed with bentonite and calcium hydroxide at the ratio of 80:15:5 (w/w) and manufactured as a pellet type at the size of 10 mm. Field experiments were conducted to evaluate the effects of fly ash fertilizer on the soil quality and crop growth compare to the control (no fertilizer) and, - traditional fertilizer. Results showed that soil pH and organic matter in paddy soils after applying the manufactured fly ash fertilizer were not increased compared to the other two treatments. However, the concentration of available phosphate and silicate in paddy soils were higher than those of the control and traditional fertilization. With regard to crop growth, no significant difference was observed between three different treatments. However, the content of protein in the rice grain cultivated with the fly ash fertilizer was higher than in the rice cultivated by other two treatments. Overall, fly ash fertilizer could increase the concentration of available silicate and phosphate in the paddy soil and improve the rice quality. In conclusion, fly ash can be utilized in agricultural soils as soil amendment, especially in the rice paddy soil.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.152-157
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• 2016

BACKGROUND: Since bottom ash (BA) contains considerable amounts of CaO and MgO, it could be a useful amendment to increase soil pH and to immobilize cadmium (Cd). This study was conducted to evaluate effect of BA application in reducing Cd phytoavailability.METHODS AND RESULTS: Bottom ash was applied at the rate of 0, 20, 40, and 80 Mg/ha to Cd contaminated soil, and then lettuce was cultivated under field condition. soil pH and net negative charge increased slightly with increasing BA application; however, there was no statistical difference among the rates. Water soluble, exchangeable+acidic, reducible, and oxidizable fraction of Cd decreased with increasing bottom ash application rate, whereas residual fraction of Cd increased with increasing bottom ash application rate. Lettuce yield increased with rate of bottom ash up to 40 kg/ha. Visual evidences of cadmium toxicity and growth inhibition were not found during lettuce cultivation.CONCLUSION: Bottom ash was effective to reduce phytoextractability of Cd and to increase lettuce yield. Conclusively, BA could be a good soil amendment to reduce Cd phytoavailability in contaminated arable soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.333-338
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• 1999

The experiment was carried out to find the effects of the application method of dairy liquid manure on productivity of silage corn(P3352) and sorghum $\times$ sudangrass hybrid(P988) and physical and chemical properties of soil during 2 years at Suwon. Crude protein content of T1(Chemical fertilizer) was highest by 6.5%, 8.9% in both forage, respectively, but total digestible nutrient(TDN) percent of T3(dairy liquid manure, basal + chemical fertilizer, topdressing) was highest by 73.8%, 59.0% in both forage, respectively. In TND yield, it was little different between T1(9.5 MT/ha) and others(8.4~9.3 MT/ha) at silage corn, but T4(chemical fertilizer at basal + dairy liquid manure at topdressing) was highest as 13.3 MT/ha at sorghum $\times$ sudangrass hybrid(p<0.05). pH of the soil after experiment was lower than that of the soil before experiment in the both forages, but soil organic matter was high at after trial than before trial. Available phosphorous and exchangeable cation were not shown the regular trend in this experiment. Based on the results of this experiment, it was not shown among different application method for silage corn (P3352), but application of chemical fertilizer at basal and liquid manure at topdressing was good for sorghum $\times$ sudangrass hybrid(P988).

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.1
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• pp.85-102
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• 1993

This study was conducted to achieve develop organic sludge recycling technology as sludge make a prey of earthworm. Therefore sludge treatment and recycling technology is an important field by which this research project to solve landfill site and reduction treatment expense using vermicomposting treatment process on the waste sludge from the biological wastewater treatment plant. In experimental results on the optimum conditions of vermicomposting of nightsoil treatment sludge, survival rates were observed 98.3% in temperature of $10-15^{\circ}C$, 75% in pH 5.8-7.5 and 100% in density of $1/79.8cm^3$, respectively. Liveweight changes of earthworm were increased 266% in temperature of $10-15^{\circ}C$, 227% in pH 5.8-7.5 and 325 % in density $1\;cap./79.8cm^3$, respectively. Casting production rate were generated 0.06 g/cap./day in temperature $20-25^{\circ}C$, 0.065 g/cap./day in pH 5.8-7.5 and 0.1 g/cap./day in density $1\;cap./79.8cm^3$, respectively. Cocoon production numbers were observed 3.8 ea. /cap.in $10-15^{\circ}C$, 2.95 ea./cap.in pH 5.8-7.5 and 3.16 ea./cap. in $1\;cap./79.8cm^3$ during 6 weeks, respectively. pH was droped by 6.2 to 5.7, volatile solids was decreased by 2.9%, $NH_3-N$ were also reduced by $6.984{\mu}g/g$ to $0.991{\mu}g/g$. $NO_3-N$, however, were increased by $3.213{\mu}g/g$ to $7.706{\mu}g/g$. Fecal coliforms and pathogenic bacteria are analyzed by microbiological method to assess public health safety of casting. Number of fecal coliform groups were reduced 88.6-99.1% (Avg. 95.7%) approximately. And pathogenic bacteria such as Salmonella, Shiegella and Vibrio, were not isolated from the earthworm cast.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.62-69
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• 2008

There has been a recent trend in Korea that treatments for combustible wastes among municipal solid waste (MSW) by those methods, such as incineration and landfill are restricted as much as possible and Mechanical Biological Treatment (MBT) are encouraged actively in order to promote resource recovery. To build and operate properly these facilities, the physicochemical characteristics of MSW should be analyzed precisely beforehand. In particular, designing a crusher or separator properly which is the main process in MBT facilities of MSW. require the information on the size distribution characteristics of MSW, but they are nor sufficient in the qualities and quantities yet as of now. Accordingly, this study aims to evaluate size distribution characteristics of MSW and its physicochemical characteristics by size. The samples of MSW were collected from detached dwelling area, apartment area, business area, and commercial area of A city in Korea. According to the result of analysis, paper records 29.78~60.02% by wet weight basis, so it was the most regardless of the regions where the wastes were generated. And in terms of element analysis, Carbon(C) was 34.77~44.39%, the largest friction, and Oxygen(O) was the next occupying 19.46~33.71%. As indices of RDFs, Chlorine(Cl) was 0.39~0.83%, so it was less than the standard, 2.0%(by dry weight basis); moreover, Sulfur(S) did not exceed the standard, 0.6%, either. In the size distribution of MSW, waste fraction ranging 50~80mm in diameter was the most in combustible waste while 30~50mm was in incombustible waste.