• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.56-62
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• 1986

Fertilization response on production and quality of flue-cured tobacco as to different level of nitrogen, phosphorus, and potassium were studied in a field experiment. The results were summarized as follows: 1. Growth and yield of flue-cured tobacco were significantly better in higher nitrogen fertilization levels, regardless of soil fertility, but the negative correlation was recognized between the quality of leaves and the amounts of nitrogen application. While, both fertilizers of phosphorous and potassium did not have should little effect on the tobacco yield and quality. 2. The optimum ratio of N, P, and K fertilizer applications were decided by the appearance of the proper yield and the best quality of tobacco leaves. The proportion of N:P:K was 2:1:4. 3. The single effect (Complete plot minus Non-fertilized plot) of N, P, and K on yield and quality of cured leaf was greatly affected by nitrogen, but the combined effect (Nutrient deficiency plot minus Non-fertilzier plot) of that were only slightly affected by P and K.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.8-14
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• 2000

Long term cultivation crops like tomato, capsicum, melon etc. demand much amount of continuous supplying of nutrition during the whole growing periods. It is not easy to cover satisfactorily the nutritional demands for them by splitted top dressings, slow release fertilizer applications and fertigation systems. To overcome these problems, the "CULTAN" (Controlled Uptake Long Term Ammonium Nutrition) Beaker Deposit techniques have been developed and it was put into PVC beaker with the combined nitrogen fertilizer type mixed with the ratio of one-third of ammonium sulfate-N and two-thirds of urea-N, in which nitrogen was loaded on the demanding amount of a tomato plant during the growing period. Gypsum was mixed as a binder, and loamy soil and compost were used as a diffusion regulator. It was placed upside down into root zone of tomato at the transplanting. Tomato roots were spreaded into the Deposit beaker by ammonium ions which attract root growth. The tomato fruit yield and nitrogen uptake by plant were increased by application of $NH_4$-Beaker deposit fertilizer rather than those of common fertilizer treatment. In conclusion, it was able to improve economic and ecological benefits through CULTAN system compared with common fertilization systems. CULTAN system was estimated as a prospective alternative to enhance productivity and minimize nutrient lose. In addition, it shows further developing possibility of CULTAN system by the supplement of micro-nutrients and pesticides in the macro-nutrient beaker deposits.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.5
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• pp.85-92
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• 2016

The eight mixes and artificial soil aggregates were prepared for evaluating the practical application of lightweight foamed concrete as soil aggregates. The main parameter was unit binder content ranged between from 100 to $800kg/m^3$. In lightweight foamed concrete, flow, slurry and dried density, and compressive strength at different ages were measured. In Artificial soil aggregates crushed from lightweight foamed concrete, particle size distribution, pH, coefficient of permeability, cation exchange capacity(CEC), and ratio of carbon to nitrogen(ratio of C/N), were measured. The test results showed that flow, slurry and dried density, and compressive strength at different ages of lightweight foamed concrete increased with the increasing of unit binder content. Compressive strength at age of 28, of lightweight foamed concrete with unit binder of more than $500kg/m^3$, was more than 4 MPa. The ammonium phosphate immersion time of more than age of 3, was effective to decrease pH of artificial soil aggregates. In addition, artificial soil aggregates was evaluated as high class in terms of cation exchange capacity(CEC), while satisfied with value of ratio of carbon to nitrogen(ratio of C/N) recommended by landscape specification.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.447-453
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• 2016

The reduction technologies of exhaust gas from both the off-road engine and on-road vehicles are important. It is possible to apply various combustion technologies with engines after the application of a treatment technology to this field. In this study, main injection timing, pilot injection timing, and exhaust gas recirculation (EGR) rate were selected as the experimental parameters whose effects on the emission of exhaust gases and on the fuel consumption characteristics were to be determined. In the experiment, the emission of nitrogen oxide (NOx) and Smoke, and the Torque at the same fuel consumption level, were measured. The experimental data were analyzed using the Taguchi method with an L9 orthogonal array. Additionally, analysis of variation (ANOVA) was used to confirm the influence of each parameter. Consequently, the level of each parameter was selected based on the signal-to-noise ratio data (main injection timing, 3; pilot injection timing, 3; EGR rate, 2), and the results of the Taguchi prediction were verified experimentally (error: NOx, 10.3 %; Smoke, 6.6 %; brake-specific fuel consumption (BSFC), 0.6 %).

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.316-321
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• 1994

We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.245-249
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• 1986

A pot and laboratory experiments were conducted to find out the effects of pretreatments of rice straw and silica fertilizer in submerged and upland soil condition on the evolution of nitrous oxide with different application time. The results obtained were summarized as follows; 1. Evolution of nitrous oxide was remarkably increased with pretreatment of rice straw and silica in upland condition than that of submerged condition. 2. Effects of application time of rice straw and silica fertilizer on the evolution of nitrous oxide were high in order of two weeks before transplant > early spring (February) > late autumn (November) application. 3. The consumption ratio of carbon for the evolution of one mole nitrogen was pronounced more in submerged condition than that of pretreated in upland condition. Application of rice straw with silica fertilizer was remarkably reduced the consumpotion of carbon on the denitrification path way. 4. Amount of mineral nitrogen as $NH_4^+-N$, $NO_2^--N$, and $NO_3^--N$, and nitrification rate were remarkably high in pretreatment of rice straw and silica in upland condition than that of contineusly submerged soil condition.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.11-19
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• 1988

This study was conducted to relate among growth characteristics, quality, and chemical components for flue-cored tobacco. The results are summarized as follows : 1. Starch content in harvested green leaf was correlated negatively with leaf length, leaf width, leaf area, and leaf weight of harvested green leaf, respectively, while positively with total sugar content in cured leaf, and the ratio of leaf length to leaf width of harvested green leaf. 2. Organic matter and total nitrogen contents in the soil were correlated positively with nicotine content in cured leaf, respectively, and total nitrogen in the soil negatively with total sugar content in cured leaf. 3, Amount of fertilizer, application date of MH, priod of harvesting, and yield were correlated positively with nicotine content in cured leaf, respectively , while negatively with total sugar content. Application amount of MH was correlated positively with total sugar content, but negatively with nicotine content in cured leaf. Also amount of compost was correlated negatively with nicotine content in cured leaf. 4. The ratio of total sugar to nicotine (TS/N) per plant was correlated positively with price (Won/kg) and specific leaf area, but negatively with leaf length. leaf width, leaf area, harvested leaves, and leaf weight in cured leaves, respectively. Yield was correlated negatively with TS/N per plant. 5. TS/N of the best quality tobacco per plant was 12.0. Those of the best quality tobacco in each stalk position were 42.1 for first~third leaf, 28.4 for 4th~6th leaf , 23.7 for 7th~9th leaf, 7.7 for l0th~12th leaf , and 7.8 for over 13th leaf from bottom, respectively. 6, When TS/N was 12.0, optimum values of growth characteristics per plant were 100.5 $\pm$ 10.3g for leaf dry weight, 755.1$\pm$53.2cm for leaf length, 294.4$\pm$25.1cm for leaf width, 8, 892$\pm$111cm2 for leaf area, 16.0$\pm$0.6 leaves for harvested leaves, and 7.32$\pm$0.44mg/cm2 for specific leaf area, respectively. 7. When TS/N was 12.0, optimum values of chemical components per plant were 1.92$\pm$0.28% for nicotine content, and 20.4$\pm$ 1.4 % for total sugar content, and that of yield was 238.3$\pm$ 9.8kg/10a.

• International Journal of Highway Engineering
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• v.19 no.1
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• pp.53-62
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• 2017

PURPOSES : This research was a fundamental study on the application of an integral $TiO_2$ solution to asphalt concrete pavement. The integral $TiO_2$ solution was produced in pilot production equipment; application of the integral $TiO_2$ solution to asphalt pavement was conducted to examine the pollution-reducing capability of photocatalytic compounds such as $TiO_2$. The photocatalytic $TiO_2$ reacted with air pollutants, converting them into small amounts of relatively benign molecules. METHODS : In this study, laboratory experiments were conducted using five various testing methods. Tensile strength ratio (TSR) and British pendulum test (BPT) were conducted in order to evaluate the properties of asphalt pavement subsequent to the integral $TiO_2$ solution coating. In addition, methylene blue testing, a measurement of nitrate on the coated pavement, and nitrogen oxide (NOx) reduction testing were conducted in order to evaluate photocatalytic reaction. Lastly, a UV-A lamp was used as a light source for photocatalytic reactions. RESULTS : Test results indicated no change in the properties of asphalt pavement following the integral $TiO_2$ solution coating. In order to evaluate the performance of asphalt pavement as a function of $TiO_2$, the moisture susceptibility and skid resistance were investigated. The moisture susceptibility and skid resistance satisfied there quirements related to pavement quality and safety specification. Furthermore, the effects of reduction of air pollution were significantly improved as determined via the methylene blue test and NOx reduction test. The $TiO_2$-paved asphalt specimen exhibited approximately 43% reduction of NOx. CONCLUSIONS : This study has suggested that applying $TiO_2$ rarely impacts asphalt pavement performance measures such as moisture susceptibility and skid resistance, and that its application may be a better means of reducing air pollution. Further studies, such as proper $TiO_2$ dosage rates and compatibility with various pavement types, are required to broaden and generalize its application.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.132-137
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• 1993

This study was conducted to establish a safe cultivation technique of rice in the area irrigated with polluted water. The changes of water and grain quality were investigated in the two paddy soils which are located in the adjacent of Geumho river in 1991. The results obtained in this study are as follows : 1. The qualities of irrigation water were shown to be in the range of 6.7~7.4 in pH, 21.3~52.8ppm in COD. 3.2~5.3ppm in $NH_4-N$ and 1.6~6.0ppm in $PO_4$, respectively. Concentration of COD and $NH_4-N$ were over the standard levels. Therefore, the water pollution was mainly caused by organic waste matters. 2. Ranges of the Soil pH of Gyeongsan and Gyuam series were 5.6~6.0, 6.1~6.3 respectively. The contents of avaiable $P_2O_5$ and $SiO_2$ were high in the silicate treatment plots among other plots. 3. Degree of irrigation water pollution of Geumho river showed the highest peak in June. 4. Plant height, number of panicle and yield of rice grain were not decreased by the diminution of nitrogen fertilizer application. 5. The $Mg/(K{\times}N)$ ratio and Gel consistency of milled rice were increased in the nitrogen decreasing plot, but the alkali digestability value and protein content were decreased. Therefore, it was desirable to decrease the amount of nitrogen fertilizer application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.25-32
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• 2016

A long-term field experiment under different fertilization treatments had been conducted to explore the effects of rice yield and soil chemical properties from 1978 to 2008 in Suwon, Korea. The paddy was applied eight fertilization treatments which were F0 (no fertilizer), PK (phosphorous and potassium), NK (nitrogen and potassium), NP (nitrogen and phosphorous), NPK (nitrogen, phosphorus and potassium), NPKC (NPK with compost), NPKS (NPK with straw) and NPKL (NPK with lime). Results of 31 years experiment showed that yield index (the ratio of yield in each treatment to NPK) was the lowest in F0 (0.52) and the highest in NPKC (1.18). Yield index was gradually increased in NPKC but decreased in F0 and NK. The yield index of PK, NP, NPKS and NPKL were not changed long-term treatment. Soil acidity of NPKL showed the highest with pH 7.9, and that of other treatments ranged from pH 6.3 to 6.8. Available phosphorous content of soil was increased in all plots by long-term fertilization, was the highest in PK and NPKC. Soil organic matter was higher in NPKC (1.8%) and NPKS (1.8%) than other treatments (1.3~1.4%) in the early experiment, but that was remarkably increased in only NPKC (2.5%) according to annual long-term application. Thus we suggest that annual compost application with optimum NPK could make stable and sustainable rice production.