• Journal of the Korean Electrochemical Society
• /
• v.19 no.3
• /
• pp.95-100
• /
• 2016

A method for electrochemical degradation of the perchlorate anion ($ClO_4{^-}$) using mercury film electrode has been studied. Electrochemical method has relatively simple pre-treatment. However, electrochemical method should avoid interference from hydrogen evolution at the applied potential to degradation of perchlorate ion, and thus applied electrode should have large hydrogen overvoltage which suppressed the hydrogen evolution at the working reduction potential to prevent hydrogen evolution. In this study, we used mercury film electrode as a working electrode which has a large overvoltage. Ag / AgCl (sat. NaCl) was used as a reference electrode, and platinum was used as a counter electrode. Mercury film electrode was made by cyclic voltammetry (CV) method. The deposition time was decided as 10 minute, and the stability of the mercury electrode in perchlorate solution was confirmed by CV. The reduction potential of perchlorate was checked by using CV method, and decomposition of perchlorate was performed by using chronoamperometric (CA) method. Also, ion chromatography (IC) was used to confirm the degradation rates of perchlorate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.671-675
• /
• 2002

The present study was conducted to elucidate functional properties of sulfated polysaccharides from ascidian tunics, In physical properties of the crude polysaccharides, emulsion ability and foaminess were more excellent compared with chitin and chitosan, particular dye binding capacity was prominent. Anti-blood coagulation of partially purified sulfnted polysaccharides showed with respect to APTT (Activated partial thromboplastin time). Especially, active fraction $(F_4)$ obtained by DEAE-cellulose ion exchange chromatography showed highest activity, which was approximately $20\%$ of the activity of heparin. ACE inhibitory activity also similar to anticoagulant activity. Active fraction $(F_4)$ obtained by DEAE-cellulose ion exchange chromatography showed about $34\%$, in ACE inhibitory activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.7
• /
• pp.965-970
• /
• 2003

This study has been performed to develope a method for the simultaneous determination of 1,4-dioxane (DOX), epichlorohydrin (EPC), propylene chlorohydrin (PCH), ethylene chlorohydrin (ECH) and 1,3-dichloro-2-pro-panol (DCP) in polysorbates, chloline chloride, choline bitartrate, modified starch and spices by purge and trapgas chromatography. Experimental design was used to select a suitable trap by measuring the limit of detection (LOD) and to investigate the effect of temperature and salt of extraction, and the percentage of recovery in various matrix. The LOD of DOX, EPC, PCH, ECH and DCP were 1.38$\mu\textrm{g}$, 0.23$\mu\textrm{g}$, 3.30$\mu\textrm{g}$, 3.97$\mu\textrm{g}$, 20.43$\mu\textrm{g}$ respectively, by means of using Vorcarb 3000 trap with 5$0^{\circ}C$ sample sparger. Excluding EPC, the recoveries of target compounds were above 90% in all matrix. Target compounds in polysorbates (17), choline chloride (5), choline bitartrate (5), modified starch (8) and spices (25) were not detected. But 2.5 ppm of DOX was detected in Tween 80.

• Korean Journal of Pharmacognosy
• /
• v.48 no.4
• /
• pp.329-338
• /
• 2017

This study was investigated the changes of quality stability and physicochemical characteristics of the Korean red ginsengs stored for a long times over 20 years. The Korean red ginsengs were stored for 4 to 22 years in canned packaging with polypropylene film and wooden box at room temperatures. The unusal phenomena such as discoloration and pin hole in packaging were not observed. General bacteria showed the vlaues of below 100 CFU/g, coliform groups and molds were not found in any samples stored for 22 year. Any samples also were not detected in mycotoxins. The contents of moisture, ash and crude saponin were the levels of 10.6~11.1%, 3.8~4.2% and 4.1~4.7% during the whole storage periods, respectively. The contents of maltol, which has been known as characteristic flavour and antioxidant of Korean red ginseng, showed remarkably increasing tendency from 0.10 mg/g for 4 years to 2.53 mg/g for 22 years during the storage. The contents of AFG (arginyl-fructosyl-glucose), arginine and free sugar were slightly decreased. Acidic polysaccharide and ginsenoside were not changed significantly during the storage periods. The contents of acidic polysaccharide and total ginsenosides were the 75.1~76.3 mg/g and 15.1~16.6 mg/g, respectively. The sums of ginsenoside-Rg1,-Rb1 and -Rg3s were the ranges of 9.3~9.9 mg/g and PD (ginsenoside-Rb1, -Rb2,-Rc,-Rd,-Rg3s,-Rg3r)/PT (ginsenoside-Rg1,-Rg2,-Re,-Rf,-Rh1) saponin ratios were the levels of 1.4~1.5. These results suggest that Korean red ginsengs stored for long periods show relatively stable quaility stabilities and not significantly changed the contents of ginsenoside and polysaccharide during the storage up to 22 years.

• Journal of Chest Surgery
• /
• v.13 no.1
• /
• pp.13-20
• /
• 1980

Heparin would have been used for preventing clotting of blood during extracorporeal circulation and subsequent use of protamine sulfate and made possible the neutralization of heparin. This procedure has been adopted for eliminating one of the great causes of bleeding, especially in cardiac surgery. In this experiment, the hypocoagulability of blood induced by heparin followed by neutralization with treatment of protamine sulfate were estimated by the Lee-White clotting time [CT], partial thromboplastin time [PTT] and protamine titration test. The results were as follows: 1] Comparison of clotting time between the heparinized [2.0 mg/kg] and non-heparinized dogs was done using CT and PT`I` of the blood. In heparinized group [Group I], the CT lasted infinitively and prolongation of PTT [4 times than normal] until 60 minutes. The CT [2 times] and PTT [3 times] has been shortened after 90 minutes, however they returned to normal limit level within 180 minutes. 2] The determination of appropriate ratio of heparin and protamine In vivo were performed. The group II [heparin 2.0 mg/kg, protamine 1.0 mg/kg] revealed rapid decrease of CT and PTT, but returned to normal after 120 minutes. The group III [heparin 2.0 mg/kg, protamine 2.0 mg/kg] returned rapidly to normal within 15 minutes. The group IV [heparin 2.0 mg/kg, protamine 3.0 mg/kg] recovered its normal level after 60 minutes. The group V [heparin 2.0 mg/kg, protamine 4.0 mg/kg] recovered its normal level after 90 minutes. 3] In the combined experimental study In vivo and vitro, the protamine titration test was done using the dog which were given 2.0 mg/kg and 3.0 mg/kg of heparin, respectively and coagulation time were checked after 15, 30, 60 and 120 minutes. The complete neutralization was showed to be heparin-protamine ratio of 1:1 to 1.5. 4] In vitro study, fresh blood was drawn into known amount of heparin content [20, 40, 60 and 100/ug per 1 ml of blood] syringe, thereafter protamine titration test was done. In all cases, the complete neutralization was found in heparin-protamine ratio of 1:0.85 to 1.5. 5] It was found by the present experiment that the ideal heparin-protamine ratio was 1:1 within 60 minutes and 1:0.5 after 60 minutes for avoiding the serious side effect due to overadministration of protamine sulfate.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.5 no.3
• /
• pp.149-158
• /
• 2005

This paper describes design, fabrication, and application of the silicon based temperature controllable micro reactor. In order to achieve fast temperature variation and low energy consumption, reaction chamber of the micro reactor was thermally isolated by etching the highly conductive silicon around the reaction chamber. Compared with the model not having thermally isolated structure, the thermally isolated micro reactor showed enhanced thermal performances such as fast temperature variation and low energy consumption. The performance enhancements of the micro reactor due to etched holes were verified by thermal experiment and numerical analysis. Regarding to 42 percents reduction of the thermal mass achieved by the etched holes, approximately 4 times faster thermal variation and 5 times smaller energy consumption were acquired. The total size of the fabricated micro reactor was $37{\times}30{\times}1mm^{3}$. Microchannel and reaction chamber were formed on the silicon substrate. The openings of channel and chamber were covered by the glass substrate. The Pt electrodes for heater and sensor are fabricated on the backside of silicon substrate below the reaction chamber. The dimension of channel cross section was $200{\times}100{\mu}m^{2}$. The volume of reaction chamber was $4{\mu}l$. The temperature of the micro reactor was controlled and measured simultaneously with NI DAQ PCI-MIO-16E-l board and LabVIEW program. Finally, the fabricated micro reactor and the temperature control system were applied to the thermal denaturation and the trypsin digestion of protein. BSA(bovine serum albumin) was chosen for the test sample. It was successfully shown that BSA was successfully denatured at $75^{\circ}C$ for 1 min and digested by trypsin at $37^{\circ}C$ for 10 min.

• Korean Journal of Crystallography
• /
• v.9 no.1
• /
• pp.21-29
• /
• 1998

The rare-earth orthoborate family, RM3(BO3)4 is known to be the most promising material for the microlaser host. To grow LaSc3(BO3)4 single crystal, the phase relation of the system LaBO3-ScBO3 was investigated by DTA method. LaSc(BO3)4 was the unique intermediate compound in the binary system the peritectic reaction point of which was 1495 ±2℃. Owing to the peritectic behavior of the compound, the crystal growth of the rare-earth Sc-borate was carried out by pulling from the melt-soultion of La1+xSc3-x(BO3)4. The optimal conditions for the growth of LaSc3(BO3)4 were determined by traditional CZ method : pulling speed 0.7mm/hr, rotation speed 7-10 rpm under reduction condition. Pt and Ir crucibles could be used for about 8-10 times of growth. The effect of thermal configurations on the temperature distribution was investigated. A special two-coordinate manipulator was made for the precise movement of thermocouples from the melt to the top of the furnace for several thermal configurations. The radial gradient on the melt surface depends strongly on the construction of the afterheater. On the other hand, the axial gradient was mainly propotional to both the opening degree of baffle plate and the mutual positions of crucible and heater.

• Aerospace Engineering and Technology
• /
• v.12 no.1
• /
• pp.40-45
• /
• 2013

Satellite's infrared detector shall be calibrated under thermal vacuum environment using a reference black body before a launch. The full aperture black body (FABB) as an infrared calibration reference shall be composed of vacuum compatible materials and temperature controlled from $-40^{\circ}C$ to $+40^{\circ}C$ with emissivity higher than 0.95. The temperature homogeneity over the central 80 % area of the FABB front surface shall be better than 2 K. The FABB designed by thermal and flow analysis was $1m{\times}1m{\times}8mm$ copper plate on which black painted aluminum honeycomb core was attached. Copper tubes were welded on the opposite side of the honeycomb core to allow temperature regulated gaseous nitrogen to flow through them. By the FABB validation test, the temperature homogeneity was observed around 1 K using 20 PT100 sensors and modified COTS infrared camera. The emissivity value was 0.975 at $40^{\circ}C$ under atmospheric pressure.

• Korean Journal of Plant Resources
• /
• v.23 no.1
• /
• pp.7-13
• /
• 2010

This experiment was conducted to establish the micropropagation of Calanthe discolor through multiple shoot formation from the culture of leaf, corm and root explants. Frequency of adventitious shoot formation from leaf explants was higher than those of corms and root explants. Frequency of adventitious shoot formation on medium with various concentrations of BA (0. 1.0, 3.0, and 5.0 mg/L) and NAA (0, 0.1, 0.5, and 1.0 mg/L) was tested. The maximun induction of adventitious shoot was obtained on half strength Murashige and Skoog (MS) medium supplemented with 3.0 mg/L BA and 1.0 mg/L NAA after 6 weeks of culture. Multiple shoots were transferred onto half strength MS medium with various concentrations of GA3 (0, 0.1, 0.5, 1.0, 3.0, and 5.0 mg/L). The number and length of multiple shoots on medium were highest on medium with 3.0 mg/L GA3. All the adventitious shoot grew well and rooted on half strength MS medium with 3.0 mg/L NAA. The plantlets were acclimatized up to 100% on sand with TKS-II or pearlite with TKS-II.

• Journal of the Korean institute of surface engineering
• /
• v.50 no.5
• /
• pp.411-420
• /
• 2017

In this paper, two methods of making the Pd-added $SnO_2$ ($Pd-SnO_2$) powder with pure tetragonal phase by the hydrazine method were suggested and compared in terms of crystal structure, surface morphology, and alcohol gas response. One of the addition methods is to use $PdCl_2$ as a Pd source, the other is to use Pd-based organic with oleylamine (OAM). When Pd concentration was increased from 0 to 5 wt%, the average grain size of $Pd-SnO_2$ made with Pd-OAM were decreased from 32 to 12 nm. In the case of using with $PdCl_2$, grain size of the $PdCl_2$ fell to less than 10 nm. However, agglomerated and extruded surface morphology was observed for the films with Pd addition over 4 wt%. The crack-free $Pd-SnO_2$ thick films were able to successfully fill the $30{\mu}m$ gap of patterned Pt electrodes by optimized ink dropping method. Also, the 2 wt% $Pd-SnO_2$ thick film made with PdCl2 showed gas responses ($R_{air}/R_{gas}$) of 3.7, 5.7 and 9.0 at alcohol concentrations of 10, 50 and 100 ppm, respectively. On the other hand, the prepared 3 wt% $Pd-SnO_2$ thick film with Pd-OAM exhibited very excellent responses of 3.4, 6.8 and 12.2 at the equivalent measurement conditions, respectively. The 3 wt% $Pd-SnO_2$ thick film with Pd-OAM has a specific surface area of $31.39m^2/g$.