• The Journal of Korean Academy of Prosthodontics
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• v.62 no.3
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• pp.215-223
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• 2024

The patient in this case presented with a desire to have new dentures due to discomfort with existing ones. At the initial visit, all of teeth were missing except for the mandibular left second molar. As the patient was 65 years old, treatment with dentures and implant-supported prostheses was possible under the national health insurance system, and the patient opted for the mandibular denture using implant. Temporary prostheses were initially provided for patient adaptation, and following successful adaptation period, the treatment progressed. A maxillary complete denture and a mandibular implant-supported denture using two implants in the canines were fabricated. The mandibular denture is a Kennedy Class II removable partial denture which consists of a six-unit porcelain fused to metal fixed dental prostheses supported by the implant in the canines on both sides and left second molar serving as the abutments. Despite severe bone resorption and insufficient abutment teeth, the patient expressed satisfaction with the treatment results. In cases with economic and anatomical constraints affecting the feasibility of complete denture, implant-supported overdenture, and implant-supported fixed dental prostheses, an implant-assisted removable partial denture using implant surveyed crowns proves to be a viable and effective alternative treatment option. Nevertheless, the current dearth of scientifically rigorous studies underscores the necessity for meticulous regular check-up and occlusal assessment.

• Journal of Wetlands Research
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• v.26 no.3
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• pp.227-235
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• 2024

Inland wetlands provide important ecosystem services or functions, including biodiversity conservation, water purification, flood control, and carbon sequestration. However, many inland wetlands are being degraded by urbanization and industrialization, raising the need for conservation and restoration. This study proposes the adoption of No Net Loss(NLL) of Wetland for wetland conservation and restoration in Korea by the review of the literatures. To this end,, we analyzed the wetland conservation and management systems of the United States, Canada, Germany, Japan, and Australia, and identified institutional features and success factors of each country, and sought ways to adapt them to domestic conditions of Korea. The case of the United States highlights the importance of legal frameworks and public-private collaboration, Canada demonstrates systematic management approaches, Germany maintains a balance between development and conservation, Japan underscores the need for cooperative conservation efforts, and Australia emphasizes the efficiency of offset markets. The introduction and operation of these schemes are expected to contribute to climate change mitigation, biodiversity conservation, and water quality improvement, but ongoing research and policy efforts are needed to ensure that the schemes are well established.

• Journal of Korean Society of Forest Science
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• v.64 no.1
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• pp.11-19
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• 1984

Potted, germinating Pinus rigida ${\times}$ P. taeda seedlings were inoculated with Pisolithus tinctorius (Pt) ectomycorrhizal fungus to test the effectiveness of Pt in relation to organic amendment and changes in soil fertility and soil texture. Pt was cultured as mycelia in vermiculite-peat moss mixture with nutrients and added to sterilized pot soils with or without organic amendment (fully fermented compost) at three soil texture levels (sand, loamy sand, and sandy loam) in a factorial design. Plants were grown in a greenhouse for 4 months and harvested to compare their growth with non-mycorrhizal plants and plants infected by natural fungi. Regardless of sod texture, soil fertility, or organic amendment, seedlings inoculated with Pt were better in dry weight and height than non-mycorrhizal plants or those infected by natural fungi. An exception was observed in the most fertile soil (0.075% N and 1.32% organic matter content in sandy loam with organic amendment), where non-mycorrhizal plants were slightly bigger (8%) and heavier (18%) than Pt-inoculated plants. In over-all average, Pt-inoculated seedlings were 30% taller and 107% heavier than those infected by natural fungi and 31 % taller and 60% heavier than non-mycorrhizal plants. Growth stimulation of seedlings by Pt was more pronounced in less fertile sand soil when organic was not amended. Mycorrhizal frequency of Pt (% of mycorrhizal root tips) was reduced to about half (from 84 to 33% in sandy loam and from 77 to 40% in loamy sand) by organic amendment, while that of natural fungi was not significantly affected. Severe nitrogen deficiency was observed in the needles of non-mycorrhizal plants (1.38% N), while both Pt-inoculated plants (1.68% N) and those infected by natural fungi (1.89% N) did not develop symptom, suggesting an active role of mycorrhizae in absorption of soil nitrogen. Top to root ratio increased with organic amendment to non-mycorrhizal plants, but was not significantly affected by fungal treatment. It was concluded from this study that relative effectiveness of Pt was determined by soil fertility. Organic amendment to less fertile sand soil increased effectiveness of Pt, while the same amendment to more fertile loamy sand and sandy loam decreased effectiveness of Pt. Benefits of Pt mycorrhizae would be expected most either when organic was not added to the soil, or when soil nutrients were not abundant.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.9
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• pp.961-972
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• 2008

In 2004, total emissions of Greenhouse Gases(GHGs) in Korea was estimated to be about 590 million metric tons, which is the world's 10th largest emissions. Considering the much amount of nation's GHG emissions and growing nation's position in the world, GHG emissions in Korea should be reduced in near future. The CO$_2$ emissions from two sub-sections of energy sector in Korea, such as thermal power plant and industry section(including manufacturing and construction industries), was about 300 million metric tons in 2004 and this is 53.3% of total GHG emissions in Korea. So, the mitigation of CO$_2$ emissions in these two section is more important and more effective to reduce the nation's total GHGs than any other fields. In addition, these two section have high potential to qualitatively and effectively apply the CCS(Carbon Capture and Storage) technologies due to the nature of their process. There are several CCS technologies applied to these two section. In short term, the chemical absorption technology using amine as a absorbent could be the most effectively used. In middle or long term, pre-combustion technology equipped with ATR(Autothermal reforming), or MSR-$H_2$(Methane steam reformer with hydrogen separation membrane reactor) unit and oxyfuel combustion such as SOFC+GT(Solid oxide fuel cell-Gas turbine) process would be the promising technologies to reduce the CO$_2$ emissions in two areas. It is expected that these advanced CCS technologies can reduce the CO$_2$ avoidance cost to $US 8.5-43.5/tCO$_2$. Using the CCS technologies, if the CO$_2$ emissions from two sub-sections of energy sector could be reduced to even 10% of total emissions, the amount of 30 million metric tons of CO$_2$ could be mitigated.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.29-37
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• 2008

This study examined principles and techniques of efficient water quality management as well as total coastal pollutant loads and the relevant examples in the advanced countries from the viewpoints of water quality improvement and pollution control in coastal areas. The problems and improvements in an estimation of the current total pollutant loads were also pointed out. In addition, discussion was made on the relationship between total pollutant loads and environmental capacity as well as particulars requiring extensive examination on access to and study on water quality model used as prediction tool for marine environment. Furthermore, this study proposed details of and improvement plans for water quality control to be reflected and absorbed into systems and policies related to coastal water quality. In coastal areas, which are subject to total coastal pollutant loads, it is necessary to calculate pollutant loads reduction and allocation, to propose them in detail in statement in relations to new pollution sources for the corresponding projects or plans in environmental impact assessment and prior environmental review system. Also, in relations to regional plans for coastal management, the local government concerned must focus more on environmental management plan to implement data on pollution sources and pollutant loads flown into sea areas under basic jurisdiction, therefore it is required to actively respond to expansion and introduction of total coastal pollutant loads system in the future. Total coastal pollutant loads system must be expanded and executed by considering characteristics of sea area and changes in the environment of land. For pollution sources in land, the competent authorities in charge of coastal environment will need to initiatively administer supervision, monitoring activities and achieve integration and operation of the related laws by preparing legal bases for management system or adjusting the related laws.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.376-383
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• 2003

To utilize composts more efficiently, combining composts with fertilizer to meet crop requirements is an appealing alternative. A pot experiment was conducted to study the effect of application rate of composted pig manure blended with fertilizer on the availability and loss of fertilizer-N. Chinese cabbage (Brassica campestris L. cv. Samjin) plants were cultivated for 30 and 60 days. 15N-Labeled urea ($5.24\;^{15}N\;atom\;%$) was added to soil at $450mg\;N\;kg^{-1}$, and unlabeled compost ($0.37\;^{15}N\;atom\;%$) was added at 0, 200, 400, and $600mg\;N\;kg^{-1}$. The amount of plant-N derived from urea was not affected by compost application at rate of $200mg\;N\;kg^{-1}$. However, compost application at 400 and $600mg\;N\;kg^{-1}$ significantly (P<0.05) increased plant assimilation of N from urea irrespective of sampling time, probably because of physicochemical changes in the soil properties allowing urea-N to be assimilated more efficiently. The amount of immobilized urea-N increased with increasing rate of compost application at both growth periods, as the results of increased microbial activities using organic C in the compost. Total recovery of urea-N (as percentage of added N) by Chinese cabbage and soil also increased with increasing rate of compost from 71.5 to 95.6% and from 67.0 to 88.2% at the 30- and 60-days of growth, respectively. These results suggest that increasing rate of compost blending increases plant uptake of fertilizer-N and enhances immobilization of fertilizer-N, which leads to decrease in loss of fertilizer-N. However, information about the fate of immobilized N during future crop cultivation is necessary to verify long-term effect of compost blending.

• Membrane Journal
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• v.19 no.3
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• pp.252-260
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• 2009

The effects of the treatment of an acidic solution at pH 2 on polyacrylonitrile ultrafiltration (UF) membranes were investigated using a circular cross-flow filtration bench with a membrane module. A substantial reduction in the membrane permeability was observed after 80 hours' treatment of the acidic solution. In addition, the analyses of the sample solutions by ultraviolet/visible absorption spectroscopy and gas chromatography/mass spectrometry (GC/MS), which were taken from the feed tank as a function of the treatment time, showed that a new organic compound was produced in the course of the treatment. From a thorough search of the mass spectral library we presumed the new compound to be 1,6-dioxacyclododecane-7,12-dione (DCD), one of the well-known additives for polyurethane. Based on further experimental results, including the scanning electron microscope (SEM) images and the solid-state NMR spectra of the membranes used for the treatment of the acidic solution, we suggested that the decrease of the permeate flux resulted not from the deformation of the membranes, but from the fouling by DCD eluted from the polyurethane tubes in the filtration bench during the treatment. Those results imply that the reactivity to an acidic solution of the parts comprising the filtration bench is as important as that of the membranes themselves for effective treatments of acidic solutions, for efficient chemical cleaning by strong acids, and also in determining the pH limit of the solutions that can be treated by the membranes.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.38-45
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• 2017

We investigated the effects of rising temperatures on the photosynthesis, mineral composition, and growth of radish (Raphanus sativus var. hortensis) in a winter cropping system using a temperature gradient tunnel to predict the impact of rising global temperatures. Vegetative growth, including shoot and root fresh and dry weights, shoot length, and root length and diameter, was high under elevated temperatures (ambient $+4^{\circ}C$ and $+7^{\circ}C$) compared with ambient temperature. At elevated temperatures, the N, P, Ca, Mg, and Fe contents were high in shoots, whereas in roots, the K, Ca, Mg, and Fe contents were high and the Cu content was low. The maximum photosynthetic rates ($22.1{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at ambient temperature $+4^{\circ}C$ and $22.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at ambient temperature $+7^{\circ}C$) at elevated temperatures were more than twice that ($9.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) at ambient temperature, whereas the water use efficiency was lower at elevated temperatures. These results suggest that rising global temperatures will lead to increased mineral absorption and photosynthesis in radish in winter cropping systems, subsequently favoring plant growth, although the water requirements will be high.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.253-260
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• 2005

Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P $(1,431{\sim}6,516mg\;kg^{-1}),\;NO_3-N\;(117.60{\sim}395.73mg\;kg^{-1})$, exchangeable Ca $(4.06{\sim}11.07\;cmol_c\;kg^{-1})$ and Mg $(2.59{\sim}18.76\;cmol_c\;kg^{-1})$, as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of $Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+,\;{NH_4}^+,\;{PO_4}^{3-}\;and\;{NO_3}^-$. Rice bran effectively removed ${PO_4}^{3-}\;and\;{NO_3}^-$ in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for $Ca^{2+}$ were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing $Mg^{2+},\;K^+,\;Na^+,\;and\;{NH_4}^+$. Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.