• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1151-1156
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• 2003

The dynamic properties of short-fiber reinforced Chloroprene rubber for vibration isolators have been studied as functions of interphase conditions and fiber content. The loss factor showed the maximum at strain amplitude 2%, and increased 0.09 for matrix, 0.05 for reinforced rubber with increasing frequency respectively. The dynamic ratio rapidly decreased with increasing strain amplitude, and some increased with increasing frequency. The better interphase condition showed the lower dynamic ratio. Therefore, the short-fiber reinforced rubber could have the better isolation in frequency ratio(${\sqrt{2}}min$.) compared to frequency ratio(${\sqrt{2}}max$.). And we have investigate the possibility of applying short-fiber reinforced rubber to automotive engine mount.

• Natural Product Sciences
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• 제15권1호
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• pp.22-26
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• 2009

Phytochemical investigation of the roots of Echiochilon fruticosum resulted in the isolation of two naphthoquinone derivatives. Compound 1 was identified as anhydroalkanin while compound 2 was identified as a new derivative 5-hydroxy 8-methoxy 2-(4-methylpent-1,3-dienyl) naphthalene-1,4-dione named as echiochiloquinone. In addition, caffeic acid 3, caffeic acid methyl ester 4 were isolated. The structures were determined by physical, chemical and spectral methods. The anti-inflammatory activity of the root extracts and compound 2 was evaluated utilizing both cotton pellet-induced and carragenin-induced rat paw edema. The ulcerogenic effect was also studied.

• 한국동물위생학회지
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• 제17권2호
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• pp.83-88
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• 1994

The studies were carried out to diagnose of disease chickens that were raised at the chicken farms located in Chung -nam province and evaluated potential of mold growth inhibition of antifungal agent, Mold-X. The diseased 25 chickens that were shown clinical sign such as anorexia, respiratory symptoms, were suspected aspergillosis. The results obtained were summarized as follows ; 1. The diseased thickens were diagnosed aspergillosis according to clinical sign, pathological finding, isolation of etiological agent. 2. The growth of mold was conciderable inhibited by the Mold-X of 300 ppm level.

• Natural Product Sciences
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• 제17권2호
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• pp.142-146
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• 2011

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract from the whole plant of Veronica peregrina (Scrophulariaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of six phenolic compounds including chrysoeriol (1), diosmetin (2), 4-hydroxybenzoic acid (3), apigenin (4), caffeic acid methylester (5) and protocatechuic acid (6). Their structures were elucidated by spectroscopic studies. Compounds 1-5 were isolated for the first time from this plant. Compounds 5 and 6 showed significant antioxidative effects in DPPH free radical scavenging and superoxide quenching activity assays.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.15-19
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• 1996

To utilize the waste materials and develope wood adhesive from isolated bloods of slaughtered cow and pig and also to prevent water pollution, simple and rapid method of isolation and purification of plasma proteins from pig bloods with trichloroacetic acid(TCA) treatment was developed. Adding of TCA-precipitated blood powder to the phenol formaldehyde resin(PF) improved dry and wet strength of plywood and resulted in fast hot pressing times.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1243-1246
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• 2006

As remodeling market is growing and peoples' concern on health and well-being is getting high, there is a need to apply environmentally friendly approach to remodeling an apartment houses. But, in point of the impact noise concerned, the thickness of the concrete slab and the limited ceiling height of the remodelling houses are the main constraints to improve the impact noise performance. In order to investigate the effect of the impact noise isolation as structural treatments for the structural elements, heavy-weight impact noise and tapping noise were measured in an remodeling building. As a result, structural strengthening method by H-beam was successful to enhance the impact noise level at about 3 or 4 class by the sound classification system.

• 센서학회지
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• 제24권3호
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• pp.159-164
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• 2015

Solid state electrochemical and chemo-resistive gas sensors have been used widely but can operate only under high temperature. For reducing the power consumption and optimizing the structure of the substrate of these sensors, we conducted device and circuit simulations using the COMSOL Multiphysics simulator. For assessing the effective types of substrate and heat isolation, we conducted three-dimensional thermal simulations in two separate parts; (a) by changing the shape of the contacting holes and (b) punching additional holes on the substrate. Thus, it was possible to achieve high temperature in the sensor end of the substrate while maintaining low power consumption, and temperature in the circuit.

• 생명과학회지
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• 제6권2호
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• pp.79-86
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• 1996

A bacterium producing pullulanase was from soil, and was identified Bacillus cereus and named as Bacillus cereus JK36. The optimal culture conditions for the efficident production of pullulanase from B. cereus JK36 was obtained by cultivating with the medium composed of 1% pullulan, 1% teast extract, 1% bactopeptone, 0.1% NaH$_{2}$PO$_{4}$, 2H$_{2}$O, 0.02% MgSO$_{4}$\ulcorner7H$_{2}$O at 40$\circ$C, initial pH 6.5 for 70 hours. Using the culture supernatant as crude enzyme, the optimal pH and temperature of the pullulanase of this strain were 6.5 and 50$\circ$C. In effect of pH and temperature on the stability of the enzyme, the enzyme was stable in the range of pH6.0$\sim$9.5 and up to 40$\circ$C, respectively. The hydrolysis product on pullulan was mainly maltotriose.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.13-18
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• 2006

The antioxidant activity of the extract of Erigeron annuus was assessed by means of two different in vitro tests: bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test) and the scavenging of authentic peroxynitrite in company with peroxynitrite generation from 3-morpholinosydnonimine (SIN-1). In both tests, the 85% aq. MeOH and n-BuOH soluble fractions of the crude extract showed a significant scavenging effect on peroxynitrite and DPPH radical in comparison to L-ascorbic acid. And bioassay-guided fractionation of the n-BuOH soluble fraction led to the isolation of three compounds: Apigenin (1), quercetin-3-O-glucoside (2), and caffeic acid (3). The structures of the isolated compounds were elucidated on the basis of their spectroscopic data and their antioxidant activities were measured by determining their capacity to scavenge peroxynitrite and the DPPH radical.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.423-430
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• 1998

Elastomeric bearings are frequently used as a means to isolate structural systems from earthquake loadings. The combination of rubber layers and reinforcing steel shims makes the bearings stiff axially but soft laterally The shear flexibility of these short columns can lead to relatively low buckling loads which may be further reduced when high shear strains are simultaneously imposed. The area reduction formula has been proposed to account for the reduction in buckling load due to shear. The result obtained from the formula is presumed to be conservative but the degree of conservatism is unknown. This paper describes a numerical study which aims at determining the effect of high shear strain on the critical load of rubber bearings. The results from the finite element analysis which accounts for both the material and geometric non-linearities are compared against the theoretical results in order to examine the validity of the theoretical formulas.