• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.177-182
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• 2007

This study was conducted to produce high quality ginseng seedlings by improvement of the physical properties of nursery soil. In order to select optimum nursery conditions, nursery types were treated with the yangiik nursery and semi-yangiik nursery. Soil conditioners were treated with two different materials of puffed rice husks and perlite. This experiments were tested at Gyunggido Agricultural Research and Extention Services, Hwaseng, from 2003 to 2004. Soil permeability was better at the plot of yangiik nursery than that of semi-yangjik nursery, and was better at plot of puffed rice husks than that of perlite. Soil porosity was improved 2.2% at plot of yangjiik nursery compare at that of semi-yangjik nursery, and was improved 2.0% at plot of puffed rice husks compared to control. There was no difference in the number of ginseng plants per kan among treatments. Root length was longer at plot of yangjik nursery than that of semi-yangjik nursery. More available ginseng plants per kan were obtained from the plot of yangjik nursery by more 252 seedlings than that of semi-yangjik nursery, but there was no significant difference between soil conditioners. The number of available seedlings per kan produced from yangjik nursery was 21.7% higher than those produced by semi-yangjik nursery. The number of available seedlings per kan produced from plot of puffed rice husks was 16.3% higher than that of control.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.7
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• pp.722-729
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• 2010

Over the last decades, much consideration has been given to microbiological and chemical risks, especially when wastewater was reclaimed as water resources for urban water, irrigation water and recreational water etc. We investigated the performance of UV-based processes such as UV and UV/$H_2O_2$ for both the removal of pharmaceuticals and personal care products (PPCPs) as an emerging chemical and the inactivation of pathogen with bench-scale experimental study. 38 kinds of PPCPs including antibiotics and analgesics were detected from secondary effluent used as tested water. Bench-scale experimental study showed that UV process would require considerable UV dose for the effective PPCPs removal. Contrarily, PPCPs removal efficiency significantly improved by the combination of $H_2O_2$ with UV even at a lower UV dose and, moreover, their removal efficiency increased with the increased initial $H_2O_2$ concentration. Besides naproxen (>89%), concentrations of all the investigated PPCPs decreased by more than 90% of their initial concentrations under $923\;mJ/cm^3$ of UV dose and 6.2 mg/L of $H_2O_2$. Previous studies showed that this operational condition could get 4~5 log inactivation for Total coliform, indicating that UV/$H_2O_2$ process will be appropriate to comply with the criteria of California Title 22 for Total coliform.

• Journal of the Korean GEO-environmental Society
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• v.21 no.10
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• pp.5-10
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• 2020

As the demand for the recycling of industrial by-products increases due to various environmental restrictions including the prohibition of ocean disposal, various studies regarding the recycling of industrial by-products are currently being carried out. One of the industrial by-product, coal ash is produced from thermal power generation; studies on the recycling of fly ash have been actively carried out and it is currently recycled in various fields. In the case of bottom ash, however, only a portion of the total amount generated is primarily processed into a particle size of 2~4mm or less than 2mm to be used for gardening purpose and light weight aggregate and so on. The remaining amount is buried at ash disposal sites. Therefore, various studies are needed to develop measures to use bottom ash. This study aimed at identifying the optimal particle size and mixing ratio of bottom ash to be used as CLSM aggregate. To this end, it evaluated the usability of bottom ash as CLSM aggregate, by investigating the flowability and strength change characteristics of CLSM produced with regard to the mixing ratio of weathered granite soil and bottom ash, particle size of bottom ash to be mixed and soil binder addition rate and conducting a heavy metal leaching test.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.437-443
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• 1995

Concerns on use of excess amount of chemical fertilizier and pesticide in current farming system turns both of the producer and consumer of agricultural products to an organic farming which use a less chemicals and more natural manure. Rice-duck farming system is one of the strategy to meet the purpose and this experiment was carried out to find the effect of the rice-duck farming system on the quality and yields of rice. 20day-old rice seedling were mechanically transplanted in sandy-loam paddy field and 21 day-old ducks were raised from 3 weeks after transplanting with population of 30 heads per 10a. The plots were consists of reduce fertilizer(70%) with and without duck-raising. The conventional fertilizer treatment without duck-raising was used as check. The results obtained are summarized as follows. The weeds population of test plots which were raised with duck for 3 consecutive years was less than that of test plots without duck-raising, though a speciffic population of Echinochola crusgallis were increased. The weed control effect was higer in duck-raising than in check at the maximum tillering stage but, not at later stages of rice plant. It was found that the small animals and insects inhibiting in the rice field were reduced by duck-treatment, however, there were also damages of grass leaf roller at booting stage in the plots of duck-raising. In rice-duck plot, dark green leaf color were found: 41.8 of SPAD value than 38.6 of SPAD in check plot. Higher root activity and surface soil oxidation were also observed in rice-duck plot than check plot. 3% of the increase in yield was observed by duck-treatment. However, the expected increase of the palatability wsa not observed. This may be due to the unfavorable weather conditions during the rice growing in this expriment.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.512-516
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• 2013

Pear cultivar 'Sinhwa' (Pyrus pyrifolia var. culta Nakai) was originated from a cross between 'Niitaka' and Whasan' with the aims of improving the fruit quality and the traits of cultivation and of early maturing more than 'Whasan' cultivar at Pear Research Station of National Institute of Horticultural & Herbal Science, Rural Development Administration in 1995. 'Sinhwa' was preliminarily selected in 2004 and named in 2009. The tree shows vigorous growth habit and semi-spread characters like 'Niitaka'. Furthermore, it has a sufficient and well upkeep of the flower bud, so it can be more easily cultivated in orchards. In the flower characteristics, flowering time of 'Sinhwa' is $11^{th}$ April like as maternal parent 'Niitaka'. Also 'Sinhwa' has short of pollen grains, so it is need above two pollinizer cultivars. 'Sinhwa' is highly resistant to black leaf spot (Alternaria kikuchiana) and relatively strong to pear scab (Venturia nashicola) in field condition. The optimum harvest time is around Sep. $15^{th}$ in Naju, which is ahead of 'Whasan' about 10 days in the harvest period. The fruit shape is oblate and fruit skin color is yellowish-brown during harvesting time. The average weight of fruit is 627 g, and the soluble solids content is $13.0^{\circ}Brix$. The flesh is very soft and juicy, and renders good eating quality. Shelf life is about 30 days under the room temperature condition.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.209-216
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• 2009

The aim of this study was to investigate the removal effects of the color, nutritive salts and other pollutants on piggery slurry by advanced oxidation process (AOP) system. The experimental AOP system was designed to treat 300 L of piggery slurry per hour. To enhance oxidizing power of the experimental APO system, a ultraviolet irradiation system and the ultrasonic system were attached to the AOP system. With 5 min ultrasonic treatment, COD, SS and T-N concentrations were changed from 210, 820, and 309 to 200, 760, and 262 mg/L, respectively. With 10 min ultrasonic treatment, SS and T-N concentrations tended to decrease but T-P concentration was not changed. With the treatment of both ozone and ultrasonic waves for 30 min, COD, SS, T-N and T-P decreased from 238, 900, 400, and 5 to 165, 540, 263, and 4 mg/L, respectively. With the treatment of both ozone and ultraviolet irradiation for 30 min, COD, SS, T-N and T-P decreased from 321, 340, 204, and 15 to 151, 140, 111, and 7 mg/L, respectively, and color was changed from 4,344 to 624.

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.280-286
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• 2014

This study investigated to changes in the sensory characteristics of cheonggukjang made with smoked soybean. The total organic acid content of cheonggukjang made with smoked soybeans (CSS) increased to about two times in comparison with cheonggukjang made with non-smoked soybeans (CNS). Among the organic acids, the amount of succinic acid was highest for both CSS and CNS. The total free sugar content of CSS ($228.6{\pm}8.8mg%$) was significantly reduced compared to that of CNS ($350.1{\pm}13.7mg%$). Further, the total free amino acid content of CSS ($10,123.3{\pm}301.4mg%$) was significantly increased compared to that of CNS ($8,912.5{\pm}286.5mg%$). The contents of sweet, savory and bitter taste compounds were significantly elevated in CSS when compared to that of CNS. However, there were no significant differences in the total content of fatty acids in CNS and CSS. The sensory evaluation of aroma, taste and overall quality of CSS were significantly increased compared to that of CNS. Taken together, it was expected that a smoking process is useful for the development of new fermented foods.

• Clean Technology
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• v.5 no.1
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• pp.78-85
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• 1999

In the Kimchi manufacturing industry that has recently been on its greatest growth, the rinsing process for salt-pickled Chinese cabbage in a brining step generates a vast amount of rinsing wastewater containing salts, colloids, and organics released from the raw material. In this study, the experimental method was developed to optimize the rinsing water consumption and thus to minimize the rinsing wastewater generation. The continuous counter-current rinsing basin in the actual plant was simulated through the lab-scale three batch-wise rinsing tanks. Rinsing efficiencies for the brined cabbage from the same brining tank were almost in the same level, whereas those varied substantially from source to source in the raw Chinese cabbage provided. When rinsing water used were decreased from 3.3 L/head to 2.7 L/head, no significant change was observed with respect to COD, turbidity, conductivity, $Na^+$, and $Cl^-$ concentrations in the extracted solution of the rinsed cabbage. However, the quality of the extracted solution was badly deteriorated as the amount of rinsing water used dropped down to below 2.7 L/head. The reduction of rinsing water up to 18% was proved to be possible without any negative effect on the quality of the product, Kimchi.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.285-297
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• 2023

The present study aims to investigate the acoustic performance of the creative convergence classrooms in Korea used by elementary school students under the age of 9 introduced through the school space innovation project. In order to do this, acoustic performances of three creative convergence classrooms were measured. The measured acoustic parameters were background noise levels, Reverberation Time (RT), D₅₀, Speech Transmission Index (STI), and Inter-Aural Cross Correlation (IACC). Also, acoustic parameters including Transmission Loss (TL) and standardized level difference (D_nT) have been measured for the analysis of sound insulation performance of walls. In addition, the noise level was measured according to the opening conditions of doors and windows in the classroom. As a result, background noise level was measured at an average of 28.0 dB(A) to 32.8 dB(A) when the air conditioner was not operated, and the RT did not exceed 0.6 s. There were differences in IACC according to various desk layouts, and IACC values were high in the center line and the seats near the sound source. In particular, higher IACC was measured at the seats on the center line facing the source squarely. Regarding noise level in the classroom according to the opening conditions of doors and windows, the standards were exceeded when all windows, or windows and doors front onto the corridor were opened.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.343-349
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• 2012

Exposure and risk assessments were conducted to evaluate the relative safety of mixing/loading work of indoxacarb between wettable powder (WP) and water dispersible granule (WG). Hand exposure was monitored using cotton gloves while inhalation exposure was measured using personal air monitor. Method validation for the exposure monitoring was established successfully through several experiments. Limit of determination and limit of quantitation were 0.25 and 1 ng, respectively. $R^2$ of calibration curve linearity was more than 0.9999 and reproducibility was 0.7-6. Recovery of indoxacarb from gloves, solid sorbent and glass fiber filter at three different levels was 81.5-108.8%. Trapping efficiency and breakthrough tests gave 981.5-108.8% of recovery. During mixing/loading procedure, hand exposure amount (75 percentile of 30 repetitions) for indoxacarb WP was 6 folds (459.8 mg/kg a.i) than that of WG (81.4 mg/kg a.i). This result indicates that WG has less drift than WP thanks to its granular type of formulation. Inhalation amount was $10^{-8}-10^{-7}%$ of spray mixture prepared and $10^{-4}-10^{-3}%$ of hand exposure. In inhalation case, no significant differences were observed between two formulations. Margin of safety was calculated for risk assessment using male Korean average body weight and acceptable operator exposure level as the important exposure factors. Mixing/loading procedures for both of the formulations were considered to be of least risk because calculated MOS values were more than 1.