• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.219-224
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• 2011

The new MPV type reagent, Al-trifluoromethanesulfonyldiisobutylalane ($DIBAO_3SCF_3$), has been prepared and its reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined, and compared its reactivity with that of Al-methanesulfonyldiisobutylalane ($DIBAO_3SCH_3$) in order to understand the fluorine-substituent effect on its reactivity. In general, the reactivity of $DIBAO_3SCF_3$ appears to be much higher than that of $DIBAO_3SCH_3$, apparently due to the acidity increase by the electron-withdrawing fluorine-substituent. The reagent reduced aldehydes and ketones readily, but showed a perfect selectivity in the reduction of $\alpha,\beta$-unsaturated aldehydes and ketones to produce the corresponding allylic alcohols in an absolutely 100% purity. In addition, the reagent achieved the regioselective cleavage of phenyl- or/and alkyl-substituted epoxides to the less substituted alcohols in a perfect regioselectivity. Moreover, the reagent also showed an high stereoselectivity in the reduction of substituted cycloalkanones to produce the thermodynamically more stable alcohol epimers exclusively.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.5
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• pp.488-495
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• 2007

In this paper, SBN (Structure-Borne Noise) reduction of resiliently mounted machinery and effect of the foundation impedance on mount performance is studied. SBN reduction through the mount is analyzed by using two theoretical models; mass-spring model and wave model, in which longitudinal wave propagation is included. It is found that floor impedance greatly affects SBN reduction through lower mount, while it is almost negligible to SBN reduction through upper mount. Comparisons between measurement and predictions shows that the mass-spring model is valid only in low frequency range below few hundred Hz, while for high frequency ranges longitudinal wave propagation in the mount must be considered.

• Bulletin of the Korean Chemical Society
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• v.19 no.4
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• pp.417-422
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• 1998

The electrocatalytic reduction of molecular oxygen was investigated with a Co(II)-glyoxal bis(2-hydroxyanil) complex coated-glassy carbon (GC) electrode in aqueous media. The reduction of $O_2$ at the modified electrode was an irreversible and diffusion-controlled reaction. The complex coated-GC electrode demonstrated an excellent electrocatalytic effect for $O_2$ reduction in an acetate buffer solution of pH 3.2. The coated electrode made the $O_2$ reduction potential shift of 60-510 mV in a positive direction compared to the bare GC electrode depending on pH. The Co(II)-glyoxal bis(2-hydroxyanil) coated electrode converted about 51% of the $O_2$ to $H_2O_2$ via a two-electron reduction pathway, with the balance converted to H_2O$.

• Journal of Korean Society of Forest Science
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• v.97 no.1
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• pp.95-101
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• 2008

The wind speed reduction capability of forest belt of Caragana Korshinskili Kom in Yanchi, Ningxia province in China is as follows. 1. At the height of 0.5 m, the windbreak effect is 3-Strip (30.22%) > 2-Strip (26.53%) > 1-Strip (16.28%) from 1H (H = Tree Height) to 5H, and the windbreak effect is 2-Strip (16.11%) > 3-Strip (12.79%) > 1-Strip (9.82%) for greater than 7H. Further analysis of 2-Strip and 3-Strip revealed that the wind reduction effect of 2-Strip spread to 44H and 3-Strip spread to 27H. This result implies that 3-Strip is most effective for short distances and 2-Strip is most effective for long distances. 2. At the height of 1.0m, the wind speed was relatively constant and the reduction rate of wind speed had a minimal variation, with the reduction rate of 1-Strip (8.04%), 2-Strip (8.23%), and 3-Strip (7.43%). 3. The sandbreak effect is 2-Strip (55.28%) > 3-Strip (37.13%) > 1-Strip (20.87%). Especially, The rate of sandbreak of 1H (86.06%) of 2-Strip is most effective value in whole data.

• Journal of Oriental Neuropsychiatry
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• v.15 no.1
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• pp.101-119
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• 2004

Ginseng Radix Alba and Cyperi Rhizoma were investigated for their anti-depressant effects. For this purpose, forced-swimming test, tail suspension test, hot plate test, reserpine-induced hypothermia, aggressive behavior test were performed. In addition, the brain content of 5-hydroxyindoleacetic acid(a metabolite of serotonin), the monoamine oxidase activity, anticonvulsant effect, sleep enhancement effect were determined. The results are as follows: In the forced swimming test, Ginseng Radix diminished the duration of immobility by 45.5% compared to the control group, while Cyperi Rhizoma showed weaker effect (12.4% reduction) at 2g/kg. In the tail suspension test, the effect of Ginseng Radix(43.7% reduction) are also better than that of Cyperi Rhizoma(15.6% reduction) at 2g/kg. In the hot plate test, Ginseng Radix showed no difference as compared to control, while Cyperi Rhizoma increased the jump latency time by about 25% after administration for 10 days. In the reserpine-induced hypothermia test, both drugs slowly dropped the body temperature compared to the control group, especially the rate of hypothermia of Ginseng Radix was 24.0% at 1g/kg. In the aggressive behavior test, both drugs delayed the onset time, decreased the duration and frequency, of which effects were better in Cyperi Rhizoma. The content of 5-hydroxyindoleacetic acid in mice brain was slightly increased in Ginseng Radix, while Cyperi Rhizoma increased its level almost to the control group. Both drugs inhibited the monoamine oxidase activity in a dose-dependent manner, but the effect(51.2%) of Cyperi Rhizoma was more potent than the effect(11.8%) of Ginseng Radix. In the pentobarbital-induced sleep test, Cyperi Rhizoma exhibited no significant difference against the control group, while Ginseng Radix showed about two-fold enhancement at 2g/kg. The anticonvulsant effect of both drugs delayed the onset time, shortened the duration of convulsion and diminished the lethality, but Ginseng Radix were better than Cyperi Rhizoma.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.4
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• pp.61-75
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• 2021

Roadside greenery in the city is not only a means of reducing fine dust, but also an indispensable element of the city in various aspects such as improvement of urban thermal environment, noise reduction, ecosystem connectivity, and aesthetics. However, in studies dealing with the effect of reducing fine dust through trees in existing urban spaces, microscopic aspects such as the adsorption effect of plants were dealt with, structural changes such as the width of urban buildings and streets, and the presence or absence of trees, Impact studies that reflect the actual form of In this study, the effect of greenery composition applicable to urban space on PM2.5 was simulated through the microclimate epidemiologic model ENVI-met, and field measurements were performed in parallel to verify the results. In addition, by analyzing the results of fine dust background concentration, wind speed, and leaf area index, the sensitivity to major influencing variables was tested. As a result of the study, it was confirmed that the fine dust reduction effect was the highest in the case with a high planting amount, and the reduction effect was the greatest at a low background concentration. Based on this, the cost of planting street green areas and the effect of reducing PM2.5 were compared. The results of this study can contribute as a basis for considering the effect of pedestrian space on air quality when planning and designing street green spaces.

• Journal of Acupuncture Research
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• v.23 no.1
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• pp.25-38
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• 2006

Objectives : Acupuncture has been widely used in oriental medicine. The aim of this research is to study how does the interaction between reinforcement-reduction by twirling nine and six and subject's cold or heat tendency effect on Heart Rate Variability. Methods : We divided our subjects into 3 groups at random and classified subjects by their cold or heat tendency using questionnaire for cold-heat patternization. Group 1 is acupuncture at shinmun(HT7) reinforcement group, 2 is acupuncture at shinmun(HT7) reduction group, 3 in acupuncture at hapkok(LI4) group. According to their group, we acupunctured. Before and after acupuncture Heart Rate Variability raw data were measured during 5 minutes. LF, HF, LF norm HF norm were calculated. We analyzed these data using 3-way repeated ANOVA, Paired student T-Test. Results : 3-way repeated ANOVA showed significant interaction among LF, each group and subject's cold heat tendency(p<0.05). Paired student T-Test showed significant differences between before and after acupuncture at shinmun(HT7) reinforcement method in cold tendency men and acupuncture at shinmun(HT7) reduction method in heat tendency men(p<0.05). Conclusion : These results suggest that acupuncture at Shinmun(HT7) has an effect on declining sympathetic nerve function and has an effect on stabilizing mind through Interaction between reinforcement-reduction by twirling nine and six and subject's cold or heat tendency. We propose that more prudent care is needed about subject's cold or heat tendency and acupuncture technique of reinforcement-reduction to achieve the most suitable treatment effect.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.197-207
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• 2023

This study was conducted with the purpose of measuring the disaster damage reduction effect according to the provision of the early warning service ahead of the nationwide expansion. The damage reduction effect was measured using insurance data for 19 insured crops in areas that early warning services were provided during the period from 2017 to 2020. As a result of the measurement, it was analyzed that the early warning service had the effect of preventing or reducing disaster damage to farms. In particular, it was found that the disaster reduction effect was greater when disaster prevention facilities were equipped. The implications obtained from the results are as follows. First, by presenting subjectively experienced disaster reduction cases as numerical effects using insurance data with public confidence and objectivity, it can be used as basic data such as expansion of service area, discount of insurance premium with service adoption, and promotional materials for service subscription for early warning service. Second, in expanding and distributing early warning services, giving priority to areas or crops equipped with disaster prevention facilities can help increase the efficiency and effectiveness of the project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.535-546
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• 2008

Urbanization results in increased runoff volume and flowrate and shortening in time of concentration, which may cause frequent flooding downstream. The retardation structures are used to eliminate adverse downstream effects of urban stormwater runoff. There are various types of flow retardation measures include detention basin, retention basin, and infiltration basin. In this study, to present a rough standard about location of detention pond for attenuating peak flow of urban area, the runoff reduction effect is analyzed at outlet point when detention pond is located to upstream drainage than outlet. The runoff reduction effects are analyzed under the three assumed basins. These basins have longitudinal shape (SF = 0. 204), concentration shape (SF = 0. 782), and middle shape (SF = 0.567). Numerous variables in connection with the storage effect of detention pond and the runoff reduction effects are analyzed by changing the location of detention pond. To analyze runoff reduction effect by location of single detention pond, Dimensionless Upstream Area Ratio (DUAR) is changed to 20%, 40%, 60%, and 80% according to the basin shape. In case of multiple detention pond, DUAR is changed to 60%, 80%, 100%, 120%, and 140% only under the middle shape basin (SF = 0.567). Related figures and regression equations to determine the location of detention pond are obtained from above analysis of two cases in this study. These results can be used to determine the location of appropriate detention pond corresponding to the any runoff reduction such as storage ratio and peak flow ratio in urban watershed.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.104-117
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• 1998

Rising concern about climate change has evoked interest in the potential for urban vegetation to help reduce the level of atmospheric CO\sub 2\, a major heat-trapping gas. This study quantified the functio of home energy savings and carbon emission reduction by shading, evapotranspiration and windspeed reduction of urban vegetatioin in Chuncheon. Tree and shrub cover averaged approximately 13% in residential land. The effects of shading, evapotranspiration and windspeed reduction annually saved heating energy by 2.2% and cooling energy by 8.8%. The heating and cooling energy savings reduced carbon emissions by 3.0% annually. These avoided emissions equaled the amount of carbon emitted annually from fossil fuel consumption by a population of about 1,230. Carbon emission reduction per residential building was 55kg for detached buildings and 872 kg for multifamily buildings. Urban vegetation annually decreased heating and cooling energy cost by ￦1.1 billions, which were equivalent to annual savings of ￦10,000 savings and carbon emission reduction due to tree plantings in the wrong locations, while windspeed reduction had a great effect. Plantings fo large trees close to the west and east wall of buildings, full tree plantings on the north, and avoidance of shade-tree plantings or selection of solar-friendlytrees on the south were recommended to improve the function of building energy savings and carbon emission reduction by urban vegetation.