• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1021-1026
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• 2012

The transient mass transfer in a single droplet system consisting of 1-octanol (continuous phase)/aqueous succinic acid solution (dispersed phase) was investigated in the presence of chemical reaction, which is acid/anion exchange reaction of succinic acid and tri-n-octylamine (TOA). This succinic acid extraction by TOA can be considered to occur at the interface between organic and aqueous phase, that is, heterogeneous reaction system. The basic properties of the system such as viscosity, density, distribution coefficient, terminal velocity of droplet, and diffusion coefficient were measured experimentally or calculated theoretically, and used for theoretical calculation of characteristic parameters of mass transfer later. The effects of succinic acid concentration on the terminal velocity was negligible in the existence of TOA, although the terminal velocity increases with succinic acid concentration in the absence of TOA. On the contrary, the terminal velocity decreases with TOA concentration. While droplets falls through organic phase, the trajectory of droplets is observed to oscillate around its vertical path. A mass trnasfer cell was prepared to monitor the mass transfer behavior in a single droplet and used to measure the mean concentration of succinic acid inside droplet. The results are expressed with dimensionless parameters. Under 50 g/L succinic acid condition, the system with 0.1 mol/kg TOA showed that the molar flux decreases in proportion to the decrease of concentration gradient, while in the case of 0.5 mol/kg TOA Sh increases rapidly with time indicating the molar flux of succinic acid decreases relatively slowly compared to the decrease in concentration gradient.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.21-29
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• 1966

Dichloroisoproterenol(DCI) i; one of the well known ${\beta}$-adrenergic receptor blocking agents. According to Moran and Perkins, DCI has sympathomimetic like action in relatively low concentrations. Fleming and Hawkins confirmed that DCI acts upon the receptors concerned with positive chronotropic and inotropic actions in the heart. Vogins reported that DCI, in concentration of $5{\times}10^{-8}$ to $5{\times}10^{-6}g/ml$, had properties of sympathomimetic amine causing positive inotropic and chronotropic actions in normal rat atria. And James and Nadeau found that DCI had not only adrenergic blocking effect in moderate and higher concentrations, but it also blocked the effect on the sinus node by vagal stimulation and of directly administered acetylcholine in higher concentrations. As stated above by many authors, DCI has complicated actions according to its concentrations. Our aim at the present experiments was to study the effects of DCI to the action of ouabain and acetylcholine upon the excised rabbit atria, as well as to the action of barium chloride and acetylcholine upon the excised rabbit intestine. In addition, Pan ax Ginseng is widely used as tonics in oriental nations, its pharmacological action, however, has not been clearly established. So we atempted to investigate the effects of the water extract of Panax Ginseng to the action of ouabain and DCI upon both atria and intestine. The results obtained were as follows. 1) DCI has a negative inotropic effect on the excised rabbit atria at concentration of $10^{-5}$ and a positive inotropic effect at concentration of $10^{-6}$. 2) DCI (at concentration of $10^{-6}$) potentiates the positive inotropic effect of ouabain upon the excised rabbit atria. 3) DCI antagonizes the action of acetylcholine upon the excised rabbit atria. 4) The water extract of Panax Ginseng, at concentration of $10^{-3}$, decreases the contractile force of rabbit atria, and tends to slightly increase that of rabbit atria at $10^{-4}$. 5) The water extract of Panax Ginseng exhibits a synergistic action with ouabain on the contractile force of rabbit atria. 6) DCI, in concentrations of $10^{-7}{\sim}10^{-6}$, depresses the tone and amplitude of contraction of the excised rabbit intestine. The depression of the intestinal tone markedly appears in pretreatment with reserpine 2mg/kg 24 hours. 7) DCI antagonizes the contractile effect of barium chloride on the excised rabbit atria. 8) DCI has no significant influence on the action of acetylcholine upon the excised rabbit intestine. 9) The series of those evidences indicates that DCI has a sympathomimetic-like action and more over a relaxing action directly on the excised rabbit intestine. 10) The water extract of Panax Ginseng in concentrations of $10^{-4}{\sim}10^{-3}$, has transient depression of the intestinal tone, but later gradually recovers its normal motility: 11) The water extract of Panax Ginseng has a synergistic action with ouabain on the intestinal contractility.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.738-742
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• 2012

Here, we develop a new nanofilter device for the rapid and efficient separation of nanoparticles and biomolecules, exploiting the use of AAO mebrane with ordered nanopores in the range from 20 nm to 200 nm. Briefly, the chip comprises of a series of the upper and lower PDMS channels containing embedded inlet and outlet ports, and $50{\mu}m$ width microfluidic channel, and AAO membrane to be made the filtering zone. After assembling these components, the acrylate plastic plates were used to fix the device on the top and bottom side. When introducing the samples into the inlet ports of the upper PDMS channel, we were able to separate and concentrate the nanoparticles and target molecules at the filtering zone, and to elute the solutions containing the unwanted materials toward the lower PDMS channels normal to the direction of AAO membrane. To demonstrate the usefulness of the device we apply it to the SERS detection of nucleic acid sequences associated with Dengue virus serotype 2. We report a limit of detection for Dengue sequences of 300 nM and show excellent enhancement of Raman signals from the filter zone of the nanofilter device.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.89-95
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• 1995

The structure of boron ion-implanted pn junctio in the vacancy-doped p-type HgCdTe was investigated with the differential Hall measurement. The as-implanted junction showed the electron concentration as high as 1${\times}10^{18}/cm^{3}$ and the junction depth of 0.6.mu.m. When the HgCdTe junction was heated in oven, the electron concentration near the junction decreased and the junction depth increased as the annealing temperature and time increased. The junction structure after the thermal annealing was n$^{+}$/n$^{-}$/p. For the 200.deg. C 20min annealed sample, the electron mobility was 10$^{4}cm^{2}/V{\cdot}$s near the surface(n$^{+}$), and was larger thatn 10$^{5}cm^{2}/V{\cdot}$s near the junction(n$^{+}$). The junction formation mechanism is conjectured as follows. When HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms near the surface. The displaced Hg vacancies diffuse in easily by the thernal treatment and a fill the Hg vacancies in the p-HgCdTe substrate. With the Hg vacancies filled completely, the GfCdTe substrate becomes n-type because of the residual n-type impurity which was added during the wafer growing. Therefore, the n$^{+}$/n$^{-}$/p regions are formed by crystal defects, residual impurities, and Hg vacancies, respectively.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.371-374
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• 2004

In this paper, Ni Germane-silicide formed on undoped $Si_{0.8}Ge_{0.2}$ as well as source/drain dopants doped $Si_{0.8}Ge_{0.2}$ was characterized by the four-point probe for sheet resistance. x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FESEM). Low resistive NiSiGe is formed by one step RTP (Rapid thermal processing) with temperature range at $500{\~}700^{\circ}C$. To enhance the thermal stability of Ni Germane-silicide, Ni/Co/TiN structure with different Co concentration were studied in this work. Low sheet resistance was obtained by Ni/Co/TiN structure with high Co concentration using 2-step RTP and it almost keeps the same low sheet resistance even after furnace annealing at $650^{\circ}C$ for 30 min.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.425-432
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• 2000

Objective : It is well known that Gagamsojeokbackchool-san show antitumor effects and its activities are result from enhancement of immune function, we investigated the antitumor effects of Sambonggangyongbaneo-tang and its mechanism. Methods : We measured change of body weight, weight of immune organs (Spleen, Thymus), Liver, Kidney, tumor weight, cytotoxicity for investigation of antitumor effects of Sambonggangyongbaneo-tang. Results : 1. The body weight of mouse has no significant difference between control and sample groups. 2. The weights of immune organs (Spleen and Thymus) decreased significantly in sample groups. The weights of Liver and Kidney have no significant difference. 3. The tumor weights in mouse decreased significantly in sample groups and showed dose-dependent effect. 4. Cell viability of Sarcoma 180 has no significant difference in sample groups. 5. HeLa cell viability has no significant difference in low concentration, but it decreased significantly in high concentration. Conclusions : According to the above results, it could be suggested that Sambonggangyongbaneo-tang has prominant antitumor effects and cytotoxicity.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.443-450
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• 1997

The main purpose of this study is to investigate mineralogical and chemical changes during natural weathering, and assess the mobility of major and trace elements. Yongwol power plant utilize anthracite coal which is mainly composed of illite, kaolinite, pyrophyllite and quartz in mineralogy. Coal and coal-derived fly ash samples were sampled by the electrostatic precipitator in Yongwol coal-fired power plant in Korea. Short term weathered fly ash were also collected in ash disposal mound, and two profile soil samples were taken from an ash near the power plant. Amorphous materials are the main component of the fly ash, and mullite, quartz, magnetite and heamatite are present in all coal-derived fly ash. In chemistry, Si and Al are the most abundant elements of the total content. The ash samples were fractionated into upper $90{\mu}m$ and under $45{\mu}m$ size. Finer particles show higher concentrations in metal contents including Co, Cr, Cu, Ni, V, Zn and Pb. Concentration of Zn and Pb are nearly 4 times higher concentration in the finer particles. For the profile samples, the concentrations of $SiO_2$, $Na_2O$, MgO and $K_2O$ generally show increasing trends with depth, whereas those of $Fe_2O_3$ and $TiO_2$ appear to decrease with depth. Content of MnO does not show any specific depth trend. For the trace elements, Co, Cu, Ni and V show increasing concentrations with depth.

• Asian Journal of Turfgrass Science
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• v.3 no.1
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• pp.24-33
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• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.4
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• pp.415-422
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• 2008

This study was carried out to investigate the effect of operating and design conditions of gas dispersion type of absorber on $SO_2$ removal efficiency. pH difference between upper and lower part of gas dispersing plate of absorber was 0.2, which was relatively low. This was supposed that recirculation capacity of absorbing liquid between froth zone and reaction zone of absorber be increased by oxidation air injection through liquid riser which acted as liquid pump. Test results showed that $SO_2$ removal efficiency was more sensitive than absorber ${\Delta}P$. High $SO_2$ removal even at lower pH resulted from very low concentration of $HSO_3^-$ ion in absorbing liquid because of direct supply of dissolved oxygen into froth zone. 96% of $SO_2$ removal efficiency was obtained under the condition of absorber pH 5.2, flue gas flow rate of $1,530\;Nm^3/hr$, inlet $SO_2$ concentration of 800 ppm, absorber ${\Delta}P$ of 250mmAq. The following equation by a multiple linear regression was obtained to describe the relationship between $SO_2$ removal and operating variables. $$f=1-{\exp}(-1.3939+1.060pH+0.0139{\Delta}P-0.00267G-0.000064SO_2Conc.),\;R^2=0.9719$$

• 한국해양학회지
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• v.12 no.1
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• pp.48-53
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• 1977

Various types of iron were determined in 5 meters interval from surface to bottom layers in Yeongil Bay water of Korea, late October 1973. The contents of every type of iron decreased outward from the inner part to the entrance of the bay. But there was not any difference in iron contents among the water masses. Particulate iron and ferric iron were lower in the entrance and central parts than in the inner parts of the bay. It seemed to be caused by turbidity. The concentration of soluble iron showed higher value at the area of entrance of harbour than those of any other stations. It suggests that there may be the origin of pollutants.