• Biomolecules & Therapeutics
• /
• v.2 no.1
• /
• pp.59-64
• /
• 1994

The water extract of pilose antler of Cervus nippon var. mantchuricus (WEC) was investigated in respect of its effect on ceruloplasmin and $\alpha$$_1$-cysteine protease inhibitor (CPI), which are acute-phase proteins showing increased synthesis following inflammatory stimulus in rat. Ceruloplasmin and CPI were spectrophotometrically determined by the oxidase activity and the inhibitory activity on papain, respectively, and their changes in the concentrations in plasma or serum were examined after oral administration of 0.04% WEC to rats during 7 days following inflammation by subcutaneous injection of turpentine oil or lipopolysaccharide (LPS). WEC suppressed the maximum increases in ceruloplasmin and CPI on the 4th day after injection of turpentine oil, but the suppression in ceruloplasmin was more potent than that in CPI. On inflammation by LPS the suppression of the maximum increase in ceruloplasmin by WEC was found on the 2nd day, but the result was less significant from that obtained by the treatment with turpentine oil. Administration of WEC for at least 4 days was required to suppress the maximum increase in ceruloplasmin due to inflammation by turpentine oil. When WEC was administered to rats after injection of turpentine oil, a high dosage (0.36% of WEC) was requisite for the suppression on the maximum increase in ceruloplasmin.

• Journal of Welding and Joining
• /
• v.29 no.2
• /
• pp.88-93
• /
• 2011

This study produced hypereutectic Al-Si clad layer on 1050 Al alloy by a novel laser cladding method. Pure Si powder was mixed with organic binder to make fluid paste which could be screen-printed on the 1050 Al alloy plate. Pulsed Nd:YAG laser was irradiated on the Si paste layer to melt and alloy with Al substrate. Different laser power of 99 W, 179 W and 261 W, was used to see the difference of the microstructure, composition and hardness of the clad layers. When laser power of 179 W was used, the clad layer had overall Si content of 38wt% and composed of fine primary Si particles and fine eutectic phase. At laser power of 261 W, the clad layer had overall Si content of 24wt% and composed of mainly fine eutectic phase. Vickers hardness of HV176.7 and HV150.3 on the clad layer was obtained at laser power of 179 W and 261 W, respectively.

• Economic and Environmental Geology
• /
• v.45 no.6
• /
• pp.599-622
• /
• 2012

The phase I soil geochemical exploration was carried out targeting around Chau Binh area far from about 14 km with southeastern direction from Quy Chau within Nghe An province. The interval of sampling are horizontal 300 m with 14 line and longitudinal 500 m with 15 line, resulting in 194 soil samples. Based on the result of the phase I soil geochemical exploration, the phase II detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 56 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and Dai Loc gneissic granite complex intruding Bu Khang formation comprising of schist, gneiss and limestone. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite(about 300 g/t) and xenotime(about 10 g/t) to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the phase I soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.84 times). As a analysis result with ICP-MS on the soil samples from the phase II soil detailed pit survey, we identified outcrop considering as economic ore body at the grid point 4-7 pit with N40W attitude. As a synthetic consideration on the phase I soil geochemical exploration and phase II detailed pit survey, we tentatively designated areas considering as the extension of economic ore body with REE anomaly. In the near future, we have the plan to carry out the geophysical exploration and test drilling targeting the interval anticipated to the economic ore body.

• Journal of the Korean Chemical Society
• /
• v.63 no.5
• /
• pp.342-345
• /
• 2019

The standards for the contents of glyphosate and glufosinate in foods are specific and well categorized. However, the standard of content in animal feeds is relatively inadequate and the classification is insufficient. There is also constant debate about the risk of glyphosate and glufosinate to human health, but the risk to animals has not been well studied. In this study, we established an analytical method in feeds that is estimated to be the path for animals to ingest glyphosate. The solvent extraction was carried out using 25% methanol. After centrifugation, samples were purified using solid phase extraction (SPE) and quantitatively analysed using LC-MS/MS after concentrated. Assessment of validation was conducted through detection limits, accuracy, and precision tests. The detection limits for the established method were 1.8 of ${\mu}g/kg$ of glufosinate and $2.4{\mu}g/kg$ of glyphosate. Accuracy was ranged from 94.4% to 103.4% and precision was range from 1.5% to 7.2%. Glufosinate was detected in one sample ($ND{\sim}8.8{\mu}g/kg$) and glyphosate was detected in all but one sample ($ND{\sim}337.0{\mu}g/kg$) by applying the analytical method to animal feeds (n=13).

• Applied Microscopy
• /
• v.32 no.1
• /
• pp.9-15
• /
• 2002

Microstructural investigations of $(1-x)NdAlO_3-xCaTiO_3$ (NACT) complex perovskite compounds were carried out using X-ray diffractometry, neutron diffraction and transmission electron microscopy. When $0.3{\leq}x{\leq}0.9$, NACT had not only the 1 : 1 chemical ordering of cations but also the antiphase and inphase tilting of oxygen octahedron and the antiparallel shift of cations. Both the antiphase boundaries and the ferroelastic domains were present in the microstructure. The long and straight ferroelastic domains became degenerate as x decreases. When x was smaller than 0.3, the chemical ordering was absent and the antiphase tilting of oxygen octahedron was observed. The defects like tangled dislocations and the second phase were also found in the microstructure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.07a
• /
• pp.406-409
• /
• 2001

In this paper, the microstructure and the dielectric properties of the Sr$_{1-x}$ Ca$_{x}$TiO$_3$(0$\leq$$\chi$$\leq$0.2) -based grain boundary layer ceramics were investigated. The specimens were sintered from 142$0^{\circ}C$ to 152$0^{\circ}C$ for 4hr. in $N_2$ gas. The 2nd phase formed by thermal diffusing from the surface lead to a very high apparent dielectric constant, $\varepsilon$$_{r}$>50000. The structural properties of the specimens were studied by X-ray diffraction and SEM, EDX. All specimens exhibited cubic structure. Increasing content of Ca, the peak intensity were decreased.ed.d.

• Journal of Korean Society of Transportation
• /
• v.20 no.4
• /
• pp.197-212
• /
• 2002

지난 2001년 3월 말 개항된 인천국제공항은 대규모의 현대화된 시설을 갖춘 첨단공항이지만 일부 시설은 수용 목표 연도인 2005년보다 훨씬 빨리 그 용량이 포화상태에 이를 것으로 전망되고 있다. 특히 44개에 불과한 탑승구는 개항과 동시에 첨두시간의 수요에 미치지 못하여 항공기가 원격주기장에 대기하는 경우가 발생하고 있다. 탑승구와 원격주기장을 합한 전체 주기장 60개도 2002년에는 포화상태에 도달할 것으로 예상되어 현 인천국제공항 1단계시설의 처리능력 향상을 위한 시설별 용량 불균형 해소 방안이 시급히 요청되고 있다. 이 연구에서는 현 인천국제공항의 시설별 용량을 점검하고 조기 포화가 예상되는 시설을 밝혀낸 후 2002년부터 건설에 착수하는 2단계 건설계획의 투자방향을 제시한다. 아울러 현재의 인천국제공항이 안고 있는 시설과 운영상의 문제점을 분석하고 이를 보완 또는 개선할 수 있는 정책방향을 제시한다.

• 한국전산유체공학회:학술대회논문집
• /
• 2011.05a
• /
• pp.20-24
• /
• 2011

In this paper, numerical simulation of cavitation flow for modified NACA66 hydrofoil was made by using the multi-phase RANS equation based on pseudo-compressibility. The Homogeneous mixture model comprised of the mixture continuity, mixture momentum and liquid volume fraction equations was utilized. A vertex-centered finite-volume method was used in conjunction 2nd-order Roe's FDS to discretize the inviscid fluxes. The viscous fluxes were computed based on central differencing The Spalart-Allmaras one equation model was employed for the closure of turbulence. Reasonable agreements were obtained between the calculation results and the experiment for pressure coefficients on the hydrofoil surface.

• Applied Chemistry for Engineering
• /
• v.29 no.3
• /
• pp.356-361
• /
• 2018

It is common to analyze volatile organic compound (VOC) or semi-VOC (SVOC) in a sample composed of a complex matrix consisting of multiple components such as bloods through a separation process. Adsorption is a physical phenomenon in which certain components accumulate on the surface of other phases. In order to overcome difficulties in the pretreatment process, an adsorption is frequently used. Solid phase microextraction (SPME) equipment with porous carbon carboxen (CAR) is an example of adsorption application. In this study, the adsorption of 4-octylphenol to carboxen was examined. To do so, the extraction efficiency for such solvents as dichloromethane ($CH_2Cl_2$, DCM), ethylacetate ($CH_3COOC_2H_5$, EA) and diethylether ($C_2H_5OC_2H_5$, $Et_2O$) was studied and also the derivatization reaction for 4-octylphenol with reagents of bistrimethylsilyltrifluoroacetamide (BSTFA), methylchloroformate (MCF) and pentafluorobenzylbromide (PFBBr) was compared. The combination of DCM and BSTFA showed good performance thus they were adopted for this study. Thermodynamic adsorption experiments showed that the adsorption process was endothermic and Freundlich isotherm equation was more suitable than Langmuir isotherm. It was also found that the adsorption followed a pseudo-$2^{nd}$ order kinetic model.

• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.2
• /
• pp.167-175
• /
• 2015

A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulses with regard to their effectiveness in evoking retinal ganglion cell (RGC) responses. Retinal degeneration (rd1) mice were used (n=17). From the ex-vivo retinal preparation, retinal patches were placed ganglion cell layer down onto an $8{\times}8$ multielectrode array (MEA) and RGC responses were recorded while applying electrical stimuli. For asymmetric pulses, 1st phase of the pulse is the same with symmetric pulse but the amplitude of 2nd phase of the pulse is less than $10{\mu}A$ and charge balanced condition is satisfied by lengthening the duration of the pulse. For intensities (or duration) modulation, duration (or amplitude) of the pulse was fixed to $500{\mu}s$($30{\mu}A$), changing the intensities (or duration) from 2 to $60{\mu}A$(60 to $1000{\mu}s$). RGCs were classified as response-positive when PSTH showed multiple (3~4) peaks within 400 ms post stimulus and the number of spikes was at least 30% more than that for the immediate pre-stimulus 400 ms period. RGC responses were well modulated both with anodic and cathodic phase-1st biphasic pulses. Cathodic phase-1st pulses produced significantly better modulation of RGC activity than anodic phase-1st pulses regardless of symmetry of the pulse.