• Structural Engineering and Mechanics
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• v.52 no.5
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• pp.875-887
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• 2014

The aim of the shaking table experiment is to verify the isolation effect of a storage liquid tank with multiple friction pendulum bearings. A 1:20 scale model of a real storage liquid tank that is widely used in the petroleum industry was examined by the shaking table test to compare its anchored base and isolated base. The seismic response of the tank was assessed by employing the time history input. The base acceleration, wave height and tank wall stress were used to evaluate the isolation effect. Finally, the influences of the bearing performance that characterizes the isolated tank, such as the friction force and residual displacement, were discussed.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.1967-1972
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• 2008

Reburning is an efficient combustion technology to reduce nitrogen oxide by injecting hydro-carbon fuel to the downstream of the main combustion. In this paper LPG has been used not only as main fuel but also as reburn fuel and air was used as an oxidizer with 15kW swirl burner. Experimental studies have been done to evaluate effect of reburning for NOx reduction. Also to examine the effect of the amount of burnout air for complete combustion by reburn fuel on NOx reduction, test was conducted by reducing the amount of burnout air. Computational fluid dynamic (CFD) simulation was performed using the commercial CFD code FLUENT 6.3 to simulate experimental results and investigate the thermo-chemical characteristics. An evaluation of reaction models for swirl burner has been carried out for propane-air with two step finite-rate eddy-dissipation model in FLUENT.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.34-41
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• 2001

Semiconductors performing digital clocking are a main source of radiated emission noise. Therefore, the most secure method of reducing emission noise is to reduce emission radiated from semiconductors; an application of an absorber to the surface of semiconductors is one of these methods, too. However, in reality, it is difficult to achieve as much effect of noise reduction as expected by using only absorber. It is confirmed by experiment in this paper that a loop area within chip has no correlation with radiated emission noise and it is clarified why the existing absorber fails to achieve a satisfactory effect of emission noise reduction. Besides, a new type of chip coating absorber has been developed which can cover up to semiconductor out lead by using ferrite coating material of ferrite/epoxy acrylate substance using only permeability loss out of electromagnetic wave reduction characteristics of materials. As a result of evaluating radiated emission noise by applying this coating absorber to semiconductor device, it could be confirmed that emission noise decreased from about 3 ㏈ up to 20㏈ depending on frequency.

• Wind and Structures
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• v.10 no.5
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• pp.421-435
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• 2007

A two-dimensional flutter analysis method (2d-3DOF method) was developed to simultaneously investigate the relationship between oscillation parameters and aerodynamic derivatives of three degrees of freedom, and to clarify the coupling effects of different degrees of freedom in flutter instability. With this method, the flutter mechanism of two typical bridge deck sections, box girder section and two-isolated-girder section, were numerically investigated, and both differences and common ground in these two typical flutter phenomena are summarized. Then the flutter stabilization effect and its mechanism for long-span bridges with box girders by using central-slotting were studied by experimental investigation of aerodynamic stability and theoretical analysis of stabilizing mechanism. Possible explanation of new findings in the evaluation trend of critical wind speed through central vent width is finally presented.

• Textile Coloration and Finishing
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• v.8 no.5
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• pp.1-6
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• 1996

To obtain the basic data of the effect of antimicrobic finishing on chrome-tanned leather for apparel, it was studied that the specimens given from each step of manufacturing process, that is, steps before and after neutralization and after fixation were treated with Si-QAC as a antimicrobic finishing agent, and the antimicrobic activity was evaluated. The results were as follows: 1. The bacterial reduction of the specimens finished antimicrobically were 100% and 94.4% before and after neutralization respectively, however, the specimens carried out successive process after antimicrobic finishing exhibited the reduction of 16.5% and 14.8%. It was assumed that the antimicrobic agent was washed off by the successive process. 2. When the antimicrobic finishing was carried out on the specimens after fixation the bacterial reduction was 95.0% and then the specimen carried out successive process was 97.3%. This result indicates that antimicrobic finishing on the leather would be given after fixation rather than before and after neutralization.

• Bulletin of the Korean Chemical Society
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• v.4 no.1
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• pp.14-17
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• 1983

The effects of trialkylborane on the stereochemistry of ketone reduction with lithium borohydride were studied for the four representative ketones, namely 4-t-butylcyclohexanone, 2-methylcyclohexanone, norcamphor, and camphor. The presence of trialkylborane increased the yields of the less stable alcohols. For example, in the presence of tri-s-butylborane, 42 % yield of cis-4-t-butylcyclohexanol was observed whereas only 8 % yield with lithium borohydride alone in the reduction of 4-t-butylcyclohexanone. The in situ formation of lithium trialkylborohydride, by the hydride transfer from lithium trialkoxyborohydride to trialkylborane, was demonstrated as a possible mechanism for the catalytic effect of trialkylborane.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.202-210
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• 2018

This study was carried out to quantify degree of contribution of harvested wood product (HWP) on mitigation of climate change by valuation of public benefits, environmentally and economically. The potential carbon dioxide emission reduction of HWP was estimated by accounting carbon storage effect and substitution effect. Based on 2014 statistics of Korea Forest Service, domestic HWPs were sorted by two categories, such as wood products produced domestically from domestic and imported roundwood. The wood products were divided into seven items; sawnwood, plywood, particle board, fiberboard (MDF), paper (including pulp), biomass (wood pellet) and other products. The carbon stock of wood products and substitution effects during manufacturing process was evaluated by items. Based on the relevant carbon emission factor and life cycle analysis, the amount of carbon dioxide emission per unit volume on HWP was quantified. The amounts of carbon stock of HWP produced from domestic and from imported roundwood were 3.8 million $tCO_{2eq}$., and 2.6 million $tCO_{2eq}$., respectively. Also, each reduction of carbon emission by substitution effect of HWP produced from domestic and imported roundwood was 3.1 million $tCO_{2eq}$. and 2.1 million $tCO_{2eq}$., respectively. The results of this study, the amount of carbon emission reduction of HWP, can be effectively used as a basic data for promotion of wood utilization to revise and establish new wood utilization promotion policy such as 'forest carbon offset scheme', and 'carbon storage labeling system of HWP'.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.456-462
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• 2016

This study was conducted to analyze the effect of forest road network on accessibility and cost reduction for forest operations before and after forest road construction by investigating harvesting operations in 5 regional Forest Services (8 management planning districts). The results showed that the accessible operation area within 500 m from forest roads or public roads increased about 3.5 times after the forest road construction. The average cost reduction was 308,000 won/km/year. According to the results, forest road had a great effect on improvement of accessibility and reduction effect of forest operation cost. Therefore, the policy for expansion of forest road should be continued for preparing of effective harvesting system.

• Journal of Photoscience
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• v.7 no.1
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• pp.1-4
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• 2000

The photosensory ciliates Blepharisma japonicum and Stentor coeruleus use the hypericin-derived pigments blepharismin and stentorin, respectively, as photoreceptor chromophores. Fluorescence quenching studies have shown that the first excited singlet state of hypericin and the purified chromophores blepharismin and stentorin can be deactivated by electron transfer to an acceptor molecule with a suitable reducing potential [1,2]. This paper reports the result of a series of photobehavioral experiments performed with the aim to ascertain if the same electron accepters which quench the photoreceptor pigment fluorescence in vitro may also compete with the native acceptor molecule in its natural physiological environment. Individual cell trajectories were examined before and after light stimulation, in the presence and in the absence of potential "in vivo" electron accepters, with a microvideo-recording apparatus. Our data, on Blepharisma cells, showed that as the negative reduction potential of the electron acceptor increases, a pronounced decrease in cell photoresponsiveness was detected. A dramatic effect on cell photoresponsiveness was noticed in the presence of 1,4-benzoquinone that has the lowest negative reduction potential. Such an effect on the percentage of photoreacting cells was moderate in the case of 1,4-naphthoquinone, with a relatively higher negative reduction potential. In the presence of benzophenone, which has the highest negative reduction potential, no significant effect on photoreacting cells was noticed. Our results can support the hypothesis that in the pigment granules such a light-induced charge transfer from excited blepharismin to a suitable electron acceptor triggers sensory transduction processes in B. japonicum.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.79-83
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• 2008

The present study describes glutamate which is known as excitatory neurotransmitter is related with oxidative damages and the Viola mandshurica extracts. Showed protective effects against glutamate-induced cytotoxicity. The protective effect of antioxidant on the glutamate treated N18-RE-I05 cells was determined by a MTT reduction assay. The neuroprotective effect of methanol, ethanol, and acetone extracts from V. mandshurica against glutamate-induced cytotoxicity was assessed by the results of an MTT reduction assay. Among the three extracts, the acetone extract showed the highest protective effect by the results of an lactate dehydrogenase release assay. Therefore, these results suggest that V. mandshurica extracts could be a new potential candidate against glutamate-induced oxidative stress.