• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.404-410
• /
• 2012

This study was conducted to examine effects of harvest time (09:00 vs. 14:00), precooling at $4^{\circ}C$ vs. no precooling, and storage temperature (4 vs. $8^{\circ}C$) on the storage life of 'Maehyang' strawberry fruits for export. Fruits at a 60% ripe stage were harvested from a commercial greenhouse in Gyeongsangnamdo, Jinju on May 4, 2010. Fruits were precooled by a forced draft cooling for three hours, transported for about 30 minutes and then stored, immediately. Small precoolers set in the farm were used for precooling. Fruits were placed in constant temperature chamber (4 or $8^{\circ}C$) after packaging using PVC wrap and a cardboard box. Fruits were examined for their changes in weight, hardness, Hunter color values, soluble solids content (SSC), and incidence of gray mold (Botrytis cinerea) during storage at a two days interval from May 6 to May 14, 2010. Hardness and SSC decreased as the ripening stage progressed. The Hunter's 'L' and 'a' value of fruit color decreased as time passed. Also, fresh weight decreased during storage at all temperatures. Soft rot appeared on epidermal tissues and followed by gray mold. Incidence of gray mold was greater at $8^{\circ}C$ storage temperature than in $4^{\circ}C$ storage temperature. However, no difference by the harvested time and precooling. The results indicate that effectiveness for keeping the freshness was best achieved by precooling at $4^{\circ}C$ and storage at $4^{\circ}C$, respectively.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.10a
• /
• pp.34-34
• /
• 2019

털부처꽃(Lythrum salicaria L.)은 7~8월에 최산꽃차례로 붉은 자주색의 꽃이 피며, 밀원식물로 이용된다. 또한 예로부터 발효해서 술로 마시고 잎은 채소로 식용하였으며, 식중독 치료 및 설사를 멈추게 하는 효과가 있는 것으로 알려진 식물이다. 한국, 중국, 아프리카, 유럽, 북아메리카 등의 습한 지역에 분포한다. 본 연구는 다방면으로 이용이 가능한 털부처꽃을 관상용 소재로 개발하기 위한 최적의 유묘 재배 기술을 확립하기 위해 수행되었다. 유리온실 내에서 2019년 4월 27일에 종자를 파종하여 8주간 육묘하였다. 파종 용기는 162, 200 및 288 트레이로 달리하였으며, 토양 실험은 원예상토와 피트모스:펄라이트 3:1, 4:1 혼용토를 사용하였다. 파종립수 실험은 200구 트레이에 셀 당 1, 2, 4 및 6립으로 달리하였고, 추비는 hyponex (6.5-6-19)를 0, 250, 500, $1000mg{\cdot}L^{-1}$의 농도로 출아 후 2주 간격으로 총 3회 엽면시비하였다. 또한 차광 실험은 0, 55, 75%로 설정하였다. 대조구는 200구 트레이에 원예상토를 충진하고 셀당 1립씩 파종하여 무차광 조건에서 육묘하였으며, hyponex $500mg{\cdot}L^{-1}$를 추비하였다. 연구의 결과, 파종용기에 따른 털부처꽃 유묘는 셀 당 토양의 양이 가장 많은 162구 트레이에서 왕성하였다. 토양 종류별 실험은 원예상토 단용구에서 모든 생육이 양호한 결과를 보였으며, 피트모스와 펄라이트의 혼용토에서는 생육이 억제되었다. 파종립수에 따른 초장의 유의적인 생육 차이는 없었으나, 전반적인 생육은 1립 파종에서 우수하였다. 한편 2립 또는 4립을 파종구에서 비교적 생육이 양호하고 풍성하게 보이는 효과가 있어 관상적 이용에 적합할 것으로 생각되었다. 추비처리는 hyponex의 농도가 가장 높은 $1000mg{\cdot}L^{-1}$ 처리구에서 유묘의 생육이 가장 양호하였고, $500mg{\cdot}L^{-1}$ 처리에서는 무처리와 유의적인 차이가 없었다. 차광처리는 털부처꽃의 유묘 재배시 전반적인 생육을 증가시켰으며, 55% 차광에서 가장 우수하였다. 결론적으로 털부처꽃의 육묘는 162구 트레이에 원예상토를 충진한 다음 셀 당 2립 또는 4립을 파종하고 55% 차광 조건에서 재배하는 것이 효과적이며, 추비는 hyponex $1000mg{\cdot}L^{-1}$를 처리하는 것이 양묘 생산에 적합한 것으로 판단된다.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.4
• /
• pp.45-53
• /
• 2005

The objective of this study is to evaluate the effects of changes in soil temperature on biodegradation rate of diesel compounds from a field pilot test using hot air injection process. Total remediation time was estimated from in-situ biodegradation rate and temperature for optimum biodegradation. All tests were conducted by measuring in-situ respiration rates every about 10 days on highly contaminated area where an accidental diesel release occurred. The applied remediation methods were hot air injection/extraction process to volatilize and extract diesel compounds followed by a bioremediation process to degrade residual diesels in soils. Oxygen consumption rate varied from 2.2 to 46.3%/day in the range of 26 to $60^{\circ}C$, and maximum $O_2$ consumption rate was observed at $32.0^{\circ}C$. Zero-order biodegradation rate estimated on the basis of oxygen consumption rates varied from 6.5 to 21.3 mg/kg-day, and the maximum biodegradation rate was observed at $32^{\circ}C$ as well. In other temperature range, the values were in the decreasing trend. The first-order kinetic constants (k) estimated from in-situ respiration rates measured periodically were 0.0027, 0.0013, and $0.0006d^{-1}$ at 32.8, 41.1, and $52.7^{\circ}C$, respectively. The estimated remediation time was from 2 to 9 years, provided that final TPH concentration in soils was set to 870 mg/kg.

• Journal of Bio-Environment Control
• /
• v.32 no.4
• /
• pp.405-415
• /
• 2023

This study was conducted to investigate optimal conditions for cutting propagation of the strawberry cultivar "Sulhyang" through the collection methods of cuttings (runners tips), leaf number of cuttings, and cutting time. Cuttings were collected from the mother plant in the nursery bed (MP) and plants after fruit harvest (HP); the leaf number of cuttings was 0, 1, and 2, and the cutting time was at one-week intervals from June 4 to July 9. The survival rates for MP and HP cuttings were notably high, reaching 99.5% and 98.7%, respectively, but no significant difference was found. The number of roots were higher in MP cuttings, and there was no significant difference in crown and leaf growth. The fruit yields were 419.2 and 428.4 g, for MP and HP cuttings, respectively. The survival rates according to leaf number of cuttings were 98.1% and 98.3% for 1 and 2 remaining leaves, respectively, and remarkably lower at 25.3% for no remaining leaves. The root numbers were 26.0 and 26.3 for 1 and 2 remaining leaves, respectively, compared with 23.5 for no remaining leaves, with no significant differences in crown and leaf growth. The fruit yields were 424.4 and 421.5 g for 1 and 2 remaining leaves, respectively, and 396.7 g for no remaining leaves. The survival rates according to cutting time was over 97.2% in all cutting time without any difference in each treatment. The root, shoot, and crown of the nursery plant before planting showed the best growth in the cuttings on June 4 and 11, resulting in the highest fruit yields of 433.3 and 426.4 g, respectively, with the lowest yields at 384.5 g for cutting time on July 9. Both MP and HP materials proved suitable for strawberry cuttings. The optimal leaf number for cuttings was at least 1, and the optimal cutting time in Gyeongnam area was evaluated as around June 4-11.

• Pediatric Infection and Vaccine
• /
• v.6 no.1
• /
• pp.107-115
• /
• 1999

Purpose : Enterobiasis is probably one of the most common parasitic infection world-wide. Human is the only known host of Enterobius vermicularis. Children are more commonly infected with Enterobius vermicularis than adults and infections are commonly recurred. In Korea, there is a high prevalence. So, we performed this study to evaluate the present status of Enterobius vermicularis infection among children in the Masan, Changwon areas and to determine the efficacy of flubendazole against this parasitic nematode. Methods : From November to December, 1997, urban and rural elementary school children and urban preschool children were examined for the presence of Enterobius vermicularis egg. All the children were examined once by an adhesive cellotape anal swab technique in the early morning at home by their parents guided by specific instructions for the technique. Results : 1) A total of 644 adhesive cellotape anal swab specimens was collected from 205 urban elementary school children, 290 rural elementary school children and 145 urban preschool children. Among them, 114(17.7%) were positive for Enterobius vermicularis eggs. There was no significant differences in the rate with regard to sex. 2) In the preschool children, the egg detection rate was 42(29.0%) out of 145 children. This rate was significantly higher compared with 72(14.4%) of 499 school children. 3) The egg detection rates in the rural and urban school children were 15.2, 13.7% respectively. There was no significant difference in both groups. In the 3rd grade and below in elementary school children, there was a higher rate compared with above 4th grade group. 4) In day care center where egg detection rate was high as 41%, the children were given two doses of 100mg flubendazole every 3 weeks, including staffs and family members. After treatment, egg detection rate fatted as 6%. Conclusion : Our data demonstrated that there was high prevalence of Enterobius vermicularis infection. In the light of these results, it is necessary to examine and treat children as soon as possible.

• Journal of Korean Society of Transportation
• /
• v.22 no.7 s.78
• /
• pp.119-129
• /
• 2004

This paper is designed to report the results of development and validation procedures in relation to the Freeway Incident Management System (FIMS) prototype development as part of Intelligent Transportation Systems Research and Development program. The central core of the FIMS is an integration of the component parts and the modular, but the integrated system for freeway management. The whole approach has been component-orientated, with a secondary emphasis being placed on the traffic characteristics at the sites. The first action taken during the development process was the selection of the required data for each components within the existing infrastructure of Korean freeway system. After through review and analysis of vehicle detection data, the pilot site led to the utilization of different technologies in relation to the specific needs and character of the implementation. This meant that the existing system was tested in a different configuration at different sections of freeway, thereby increasing the validity and scope of the overall findings. The incident detection module has been performed according to predefined system validation specifications. The system validation specifications have identified two component data collection and analysis patterns which were outlined in the validation specifications; the on-line and off-line testing procedural frameworks. The off-line testing was achieved using asynchronous analysis, commonly in conjunction with simulation of device input data to take full advantage of the opportunity to test and calibrate the incident detection algorithms focused on APID, DES, DELOS and McMaster. The simulation was done with the use of synchronous analysis, thereby providing a means for testing the incident detection module.

• Korean Journal of Remote Sensing
• /
• v.38 no.6_2
• /
• pp.1607-1622
• /
• 2022

The purpose of this study is to determine the actual performance of cool roof in preventing absorbed solar radiation. The spatial correlation between surface temperature and absorbed solar radiation is the method by which the performance of a cool roof can be understood and evaluated. The research area of this study is the vicinity of Jangyu Mugye-dong, Gimhae-si, Gyeongsangnam-do, where an actual cool roof is applied. FLIR Vue Pro R thermal infrared sensor, Micasense Red-Edge multi-spectral sensor and DJI H20T visible spectral sensor was used for aerial photography, with attached to the drone DJI Matrice 300 RTK. To perform the spatial correlation analysis, thermal infrared orthomosaics, absorbed solar radiation distribution maps were constructed, and land cover features of roof were extracted based on the drone aerial photographs. The temporal scope of this research ranged over 9 points of time at intervals of about 1 hour and 30 minutes from 7:15 to 19:15 on July 27, 2021. The correlation coefficient values of 0.550 for the normal roof and 0.387 for the cool roof were obtained on a daily average basis. However, at 11:30 and 13:00, when the Solar altitude was high on the date of analysis, the difference in correlation coefficient values between the normal roof and the cool roof was 0.022, 0.024, showing similar correlations. In other time series, the values of the correlation coefficient of the normal roof are about 0.1 higher than that of the cool roof. This study assessed and evaluated the potential of an actual cool roof to prevent solar radiation heating a rooftop through correlation comparison with a normal roof, which serves as a control group, by using high-resolution drone images. The results of this research can be used as reference data when local governments or communities seek to adopt strategies to eliminate the phenomenon of urban heat islands.

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.2
• /
• pp.93-104
• /
• 2002

A field survey and experiment was conducted from 1996 to 1998 to develop rational technology for turfgrass vegetation of runway side of Incheon International Airport on the reclaimed tidal land in Young-Jong Island. Backfill of the experimental site was finished on August 1995. The experimental site was 8 ha located in the middle of the construction place for the main parking lot in front of the terminal building construction. The experimental field was drained by main open ditch, and divided three main plots, no subsurface tile drain, subsurface tile drain spacing with 22.5m, and with 45 m, respectively. The 17 sub plots were designed to test the effect of soil covering with red earth loam by 5 cm and 20 cm depth, application of chemical compound fertilizers and livestock manures, dressing of artifical soils and hydrophylic soil conditioners. The tested turfgrasses were three transplanting indigenous turfgrasses, Zoysia koreana, Zoysia sinica and Zoysia japonica, and two hydroseeding mixed exotic turgrasses, cool type I(tall fescue 30%, kentucky blue grass 40%, perenial ryegrass 30%), and cool type II(tall fescue 40%, perenial ryegrass 20%, fine fescue 20%, alkaligrass 20%). The soil backfilled with dredged seasand was sand textured with high salt concentration and low fertility. The soil showed high pH, low organic matter and low available phophate contents. The percolation rate was fast with high hydraulic conductivity. Desalinization was fast after installation of the main open drainage system. No subsurface tile drainage effect was found showing little difference in turfgrass growth. The covering and visual growth of turfgrasses were the best in the 20-cm soil covering with compound fertilizer treatment. The covering and visual growth of turfgrasses were satisfactory in the 5 cm soil covering with compound fertilizer treatment and with livestock manure treatments. The hydrophillic soil conditioner treatments were effective but expensive at present. The coverage and visual quality of turfgrasses were good for Zoysia koreana and Zoysia japonica. The coverages of turfgrasses by the hydroseeding with the mixed exotic turfgrasses were less than transplanting of native turfgrasses. In conclusion, for the runway side vegetation purposes, the subsurface tile drainage might not necessary as main open ditch drainage be sufficient due to fast percolation rate of the backfilled dredged seasand. The 5 cm soil covering with red earth might be sufficient for the runway side, but the 20 cm soil covering might be necessary for the runway side where high density of turfgrass coverage was necessary to protect from the airplance air blow.

• Journal of dental hygiene science
• /
• v.14 no.1
• /
• pp.7-14
• /
• 2014

This study aims to evaluate the impact of varying exposure to dental amalgam on urinary mercury levels in children by measuring the number of amalgam-filled teeth and the variance of mercury concentration in urine over a period of 2 years. A total of 317 (male 158, female 159) elementary school children (1st~4th graders) attending 2 schools in urban regions participated in this study. At 6-month intervals, 4 oral examinations were conducted to check any variance in the conditions of dental caries and the status of dental fillings. Also, urine tests were conducted followed by a questionnaire survey. To elucidate the factors potentially affecting the mercury concentration in urine, t-test, ANOVA, chi-square test and a mixed model were used for the analysis. Regarding the status of dental fillings in line with examination time periods, deciduous teeth had more amalgam-filled surfaces than those filled with resin, whereas permanent teeth had more resin-filled surfaces than those filled with amalgam. A significant relevance was found between the exposure to dental amalgam and urinary mercury levels. Specifically, subjects whose teeth surfaces had been filled with dental amalgam showed higher urinary mercury levels than those who had no dental amalgam fillings. Based on the analysis using the mixed model, the increase in the number of teeth surfaces filled with amalgam was found to be the factor affecting the increase in urinary mercury levels. The urinary mercury levels were found to be highly associated with the exposure to dental amalgam. The more the teeth surfaces filled with amalgam, the higher the urinary mercury levels. Hence, even a trace of dental amalgam fillings can liberate mercury, affecting the variance in the urinary mercury levels. These findings suggest that some criteria or measures should be developed to minimize the exposure to dental amalgam. Moreover, relevant further studies are warranted.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.1
• /
• pp.54-60
• /
• 2022

The planting date of corn for silage has been delayed because of spring drought and double cropping system in Korea. This experiment was conducted to evaluate agronomic characteristics, forage production and feed value of corn at April and May in 2019. Experimental design was a split-plot with three replications. Planting dates (12 April and 10 May) were designated to the main plot, and corn hybrids ('P0928', 'P1543' and 'P2088') to the subplot. The silking days of the early planting date (12 April) was 79 days and that of the late planting date (10 May) was 66 days (p<0.0001), however, there were no significant differences among the corn hybrids. Ear height of the late planting date was higher than that of the early planting (p<0.05), while there were no significant differences in plant height of corn. Insect resistance at the early planting was lower than that of late planting (p<0.05), however, lodging resistance was no significant difference at planting date. The rice black streaked virus (RBSDV) infection of early planting was 3.7% and that of late planting was 0.3% (p<0.001). Dry matter (DM) contents of stover, ear and whole plant had significant difference at planting date (p<0.05). And differences in ear percentages were observed among the corn hybrids (p<0.01). And ear percentages of early maturing corn ('P0928') was higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date (p<0.01). DM and total digestible nutrients (TDN) yields had significant difference at planting date, however, there were no significant differences among the corn hybrids. DM and TDN yields at the late planting (21,678 kg/ha and 14,878 kg/ha) were higher than those of the early planting (13,732 kg/ha and 9,830 kg/ha). Crude protein content at the early planting date was higher than that of the late planting. Acid detergent fiber content of the late planting was lower than that of the early planting date (p<0.01), while there were no significant neutral detergent fiber content difference among the corn tested. Calculated net energy for lactation (NE_L) and TDN at the early planting were higher than those of at the late planting (p<0.01). Results of this our study indicate that the late planting date (May) is better than early planting date (April) in forage yield and feed value of corn. Therefore, the delay of planting date by May was more suitable for use in cropping system.