• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.929-936
• /
• 2011

To treat non-point source pollution in Dongbok lake, removal efficiencies of pollutants were investigated in Dongbokcheon constructed wetlands (CWs) at different treatment time and wastewater loading. The wetlands consisted of forebay, wetlands ($1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, $5^{th}$, $6^{th}$, $7^{th}$, and $8^{th}$ wetlands) and sedimentation pond. The concentrations of BOD, SS, T-N, and T-P in inflow ranged $0.85{\sim}3.14mg\;L^{-1}$, $3.33{\sim}9.70mg\;L^{-1}$, $0.64{\sim}5.33mg\;L^{-1}$, and $0.03{\sim}0.10mg\;L^{-1}$ from April to October in 2008, respectively. The removal rates of BOD, SS, T-N, and T-P in Dongbokcheon CWs were 34%, 5%, 31%, and 13%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Dongbokcheon CWs were higher in the order of forebay > wetlands > sedimentation pond for BOD, sedimentation pond > wetlands > forebay for SS, sedimentation pond > forebay > wetlands for T-N. The amount of T-P removal in wetlands was higher than forebay and sedimentation pond.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.922-928
• /
• 2011

In order to properly manage the quality of water in Juam Lake, distributions and growth characteristics of submerged plants in Boknae flood control reservoir were investigated. In addition, the total amount of nutrient load by submerged plants were investigated. The total vegetation area was $1,146,849m^2$ of total flood control reservoirs ($1,848,568m^2$) before flooding. By August 19, all of Boknae flood control reservoir was flooded during rainy season. Dominant plants were MISSA (Miscanthus sacchariflorus), SCPMA (Scirpus fluviatilis) and CRXDM (Carex dimorpholepis) which occupied 87% of all flood control reservoirs. The total amounts of organic matter loads at different submerged plants were great in the order of CRXDM ($501,642kg\;area^{-1}$) > SCPMA ($20,987kg\;area^{-1}$) > MISSA ($3,413kg\;area^{-1}$). The total amounts of nitrogen loads by CRXDM, SCPMA and MISSA under different submerged plants were 56%, 3.9% and 0.8%, respectively. The total amounts of phosphorus loads at different submerged plants were on the order of CRXDM ($1,842kg\;area^{-1}$) > SCPMA ($78kg\;area^{-1}$) > MISSA ($14.8kg\;area^{-1}$). Therefore, the results of this study suggest that organic matter, T-N and T-P in water quality of Juam lake were strongly influenced by submerged plants in flood control reservoir.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.3
• /
• pp.400-407
• /
• 2011

To evaluate the aquatic ecological characteristics in Sinpyongcheon constructed wetlands for treating nonpoint source pollution, the removal rates of nutrients in water, the total amounts of T-N and T-P uptakes by water plants, and chemical characteristics of T-N and T-P in sediment were investigated. The concentrations of BOD, COD, SS, T-N and T-P in inflow were 0.07~1.47, 0.60~2.65, 0.50~4.60, 1.38~6.26 and $0.08{\sim}0.32mg\;L^{-1}$, respectively. The removal rates of BOD, COD, SS, T-N, and T-P were 14%, 6%, 18%, 24%, and 10%, respectively. The maximum amount of T-N uptake by water plants in August was $813mg\;plant^{-1}$ for Phragmites communis TRIV in $2^{nd}$ bed, $1,172mg\;plant^{-1}$ for Typha orientalis PRESL in $3^{rd}$ bed, respectively. The maximum amount of T-P uptake by water plants in August was $247mg\;plant^{-1}$ for Phragmites communis TRIV in $2^{nd}$ bed, $359mg\;plant^{-1}$ for Typha orientalis PRESL in $3^{rd}$ bed, respectively. Organic matter, T-N, and T-P contents in sediments were high in the order of $1^{st}$ bed > $2^{nd}$ bed > $3^{rd}$ bed. Microbial biomass C/N/P ratios in sediments in $1^{st}$, $2^{nd}$, and $3^{rd}$ were 78~110/3~6/1, 73~204/1~6/1, and 106~169/1~6/1, respectively.

• Korean Journal of Heritage: History & Science
• /
• v.42 no.1
• /
• pp.144-157
• /
• 2009

Nondestructive methods to check the vitality of trees and to find out internal decay of old-giant trees include the use of electrical resistance, ultrasound transmission time, microdrilling, and infrared thermography etc. Among these, ultrasound transmission offers some advantages compared to others such as it is an entirely nondestructive detection method and it can be applied to very big trees. However, the ultrasound equipment is comparatively expensive and not broadly spread yet. On the other hand, Shigometer is versatile to be applied to check vitality of the tree and find out internal decay. Electrical conductivity of plant tissues is a very useful characteristics to determine the vitality and internal decay of trees. Electrical resistance of cambial area tells about the vitality of a tree and electrical resistance of heartwood reveals discoloration or decay of it. For determination of the vitality of the tree, the standard equation for calibration of measured electrical resistances should be developed by measuring and analyzing electrical resistance from at least 30-40 trees of the same species with that tree. All the factors, especially tree species, diameter of the stem, and temperature, which can altered the electrical resistance of trees, should be taken into consideration in the development of the equation. If the standard equation is developed for old-giant trees that we should conserve, it will be very useful. In addition, periodical and continued measuring of a certain tree will help to determine the condition of the tree by comparing the measurement with accumulated data of the tree. Measuring electrical resistance of wood might not require the standard equation. But it also needs to check electrical resistance of sound wood of the same tree species. If the stems that should be examined is thicker than 40cm, it is better to use the ultrasound measurement combined to Shigometer.

• Journal of Korean Society of Forest Science
• /
• v.100 no.4
• /
• pp.623-629
• /
• 2011

The detectable levels and population fluctuations of phytoplasmas infecting dwarf mulberry trees were investigated using nested-PCR and competitive-PCR methods. Samples of five different types were studied : A. petiole of a leaf that displays dwarf symptoms, B. petiole from apparently healthy leaf residing on a branch also supports a leaf with dwarf symptoms, C. the branch portion that supports a leaf with dwarf symptoms, D. the leaf petiole from healthy appearing leaves on branch with no dwarf symptoms, and branch portion of branch with no dwarf symptoms, E. the rootlets of trees with dwarf symptoms. These 5-parts were collected from each tree during June - April, once in every two months. The phytoplasma was detected from all parts of collected mulberry samples during all seasons using nested-PCR with AS-1/AS-2 primer pairs. The phytoplasma was detected until $10^4$ dilution using direct-PCR method, but it was detected until $10^{13}$ dilution by the nested-PCR method. The density of pytoplasma was found to be $7.94{\times}10^{18}-10^{12}copies/{\mu}L$ in mulberry trees. The density of phytoplasma was observed throughout the year in all samples of mulberry trees. The highest rates of phytoplasma was found in the samples B and C during the early growing season followed by the sample A and D during the dormant season. Samples C and E displayed the highest phytoplasma density followed sample D. The density of phytoplasma appeared stable during all the seasons for samples C and A. The result of the present study demonstrates the utility of nested-PCR and competitive-PCR for detection and determination of population fluctuations of phytoplasmas in plant tissues.

• Journal of the Korean Society of Floral Art and Design
• /
• no.43
• /
• pp.123-138
• /
• 2020

This study found Flower Jewelry works in the monthly magazine specializing in flower decoration for nine years from 2011 to 2019. Based on the analysis of the type of expression, method of expression, type and number of plant materials used, and the type and number of non-plant materials used for the flower jewelry found, it was conducted to find out the trend of flower jewelry in Korea. By expression type, a total of 96 works were analyzed as 20.83% for headdresses, 57.29% for necklaces, 5.21% for earrings, 6.25% for lists, and 10.42% for other works(χ²=94.833, p<.001). According to the analysis of the frequency of use of expression techniques, headdresses, necklaces, and lists for each work were produced using five to six different expression techniques and earrings were produced using two to four expression techniques. Material coupling techniques 34.43%, flower and leaf utilization 30.17%, visual techniques 16.63%, collectivization techniques 14.12%, technical highlighting techniques 4.26%, and other 0.39% (χ²=455.222, p<.001). The most frequently used techniques were framing techniques 16.63% and knotting techniques 16.44%. Plant materials used in flower jewelry were found to be 22.61% for Phalaenopsis spp., 13.48% for Gomphrena globosa, 9.57% for Gloriosa rothschildiana, 7.39% for Epidendrum cinnabarinum, 6.96% for Chamelaucium uncinatum and 4.78% for Craspedia globosa (χ²=718.104, p<.001). In the case of branch, the most common was used with 70.00% of the Cornus walteri, and 10.00% of Actinidia arguta, Celastrus orbiculatus, and Salix pseudolasiogyne were used respectively (χ²=10.800, p=.013). In the case of foliage, 24.65% Aspidistra elatior, 24.62% Asparagus asparagoides, 11.54% Senecio rowleyanus, and 6.15% Ceropegia woodii (χ²=269.385, p<.001). In the case of berries, 44.44% of the fruits of the Smilax china, 33.33% of the Hypericum patulum, and 11.11% of the Phytolacca americana were found (χ²=11.444, p =.022). Non-planting materials used in the manufacture of flower jewelry were found to be 47.34% of 2mm aluminium wire, 33.73% of copper wire and 10.06% of 1mm aluminum wire (χ²=186.704, p<.001). The figure was 53.57% for pearls, 12.50% for ribbons, and 4.14% for spangles and feathers.

• Research in Plant Disease
• /
• v.28 no.2
• /
• pp.82-91
• /
• 2022

Recently, several in vitro studies have reported antiviral activity of agents of systemic acquired resistance against plant virus infection, but the approach has not been applied in a wide range of agricultural fields. The objective of this study was to evaluate the inhibitory effect of the exogenous application of salicylic acid (SA), chitosan (CH), or eugenol (EG) in tomato yellow leaf curl virus (TYLCV) infection of greenhouse-grown tomato plants. In vitro, the initial time of symptom was observed in TYLCV-infected plants (VP) of the resistant cultivar 'Superdotaerang' at 12 days post inoculation (dpi) after application of antiviral agents. At 32 dpi, the disease rate of TYLCV in the CHT+VP (0.1% chitosan and virus infected control) treated plants was 87.5%, lower than that of the other treatment. However, the virus content in the CHT+VP treated plants was higher than those of the other treatments, and SA, EG, and CH did not show significant effect on plant height or shoot and root fresh weight. Our results from summer-cultivated greenhouse-grown tomatoes show that none of the tested agents had an inhibitory activity on viral infection or yield of tomato 'Dotaerangsola'cultivar. In contrast, all treated 'TY Giants' cultivars that possessed TYLCV resistance genes Ty-1 and Ty-3a did not show typical symptoms and the virus content was remarkably lower than those in the TYLCV treated plants in 'Superdotaerang'. The results of this research indicated that the planting of resistant tomato cultivars was effective method instead of using SA, EG, and CH (known as resistance-inducing factors for control) of TYLCV in the field.

• Journal of the Korean Society of Floral Art and Design
• /
• no.41
• /
• pp.3-12
• /
• 2019

The purpose of this study was to investigate the effect of forest play activities on children's emotional vocabulary change. Forest play activities were conducted for 498 children aged 4 to 5 years old who visited the environmental training in G city for forest play activity for 1 hour. As a result, positive vocabulary was significantly improved from 0.95±0.78 before forest play to 1.15±1.21 after forest play(p=.003) and negative vocabulary was significantly decreased from 1.27±1.58 to 0.41±1.10(p=.000). In the case of male children, positive vocabulary was increased significantly from 0.96±0.82 to 1.36±1.24(p=.000), in the case of negative vocabulary, it decreased significantly from 1.42±1.74 to 0.55±1.30(p=.000). In the case of female children, negative vocabulary was significantly decreased from 1.12±1.37 to 0.26±0.26(p=.000), but the positive vocabulary increase was not significant(p=.851). As a result of age, for a 4-year-old children, positive vocabulary did not show significant difference between before and after forest play(p=.471), and negative vocabulary was significantly increased from 1.04 ± 1.42 before forest play to 0.41±1.16 after forest play(p=.000). For a 5-year-old children, positive vocabulary was increased significantly from 0.96±0.85 to 1.23±1.21(p=.001) and negative vocabulary was decreased significantly from 1.41±1.65 to 0.41±1.06(p=.000). As a result of this study, it was found that play activities using various natural objects in the forest were directly related to nature, resulting in positive vocabulary increase and negative vocabulary decrease.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.4
• /
• pp.257-267
• /
• 2023

Purpose. The purpose of the study was to fabricate a prototype robotic simulator for dental education, to test whether it could simulate mandibular movements, and to assess the possibility of the stimulator responding to stimuli during dental practice. Materials and methods. A virtual simulator model was developed based on segmentation of the hard tissues using cone-beam computed tomography (CBCT) data. The simulator frame was 3D printed using polylactic acid (PLA) material, and dentiforms and silicone face skin were also inserted. Servo actuators were used to control the movements of the simulator, and the simulator's response to dental stimuli was created by pressure and water level sensors. A water level test was performed to determine the specific threshold of the water level sensor. The mandibular movements and mandibular range of motion of the simulator were tested through computer simulation and the actual model. Results. The prototype robotic simulator consisted of an operational unit, an upper body with an electric device, a head with a temporomandibular joint (TMJ) and dentiforms. The TMJ of the simulator was capable of driving two degrees of freedom, implementing rotational and translational movements. In the water level test, the specific threshold of the water level sensor was 10.35 ml. The mandibular range of motion of the simulator was 50 mm in both computer simulation and the actual model. Conclusion. Although further advancements are still required to improve its efficiency and stability, the upper-body prototype simulator has the potential to be useful in dental practice education.

• Journal of Korea Water Resources Association
• /
• v.57 no.1
• /
• pp.1-8
• /
• 2024

Persistent droughts due to climate change will intensify water shortage problems in Korea. According to the 1st National Water Management Plan, the shortage of domestic and industrial waters is projected to be 0.07 billion m³/year under a 50-year drought event. A long-term prediction of water demand is essential for effectively responding to water shortage problems. Unlike industrial water, which has a relatively constant monthly usage, domestic water is analyzed on monthly basis due to apparent monthly usage patterns. We analyzed monthly water usage patterns using water usage data from 2017 to 2021 in Chungcheong, South Korea. The monthly water usage rate was calculated by dividing monthly water usage by annual water usage. We also calculated the water distribution rate considering correlations between water usage rate and climate variables. The division method that divided the monthly water usage rate by monthly average temperature resulted in the smallest absolute error. Using the division method with average temperature, we calculated the water distribution rates for the Chungcheong region. Then we predicted future water usage rates in the Chungcheong region by multiplying the average temperature of the SSP5-8.5 scenario and the water distribution rate. As a result, the average of the maximum water usage rate increased from 1.16 to 1.29 and the average of the minimum water usage rate decreased from 0.86 to 0.84, and the first quartile decreased from 0.95 to 0.93 and the third quartile increased from 1.04 to 1.06. Therefore, it is expected that the variability in monthly water usage rates will increase in the future.