• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.96-101
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• 1997

Among the lactic flora responsible for the development of acidity and characteristic flavor of Kimchi which is a traditional fermented Chiness cabbage. Homofermentative Lactobacillus plantarum is rod-shaped and to be known to ewert major role during later fermentation period. Once this strain establishes main flaora in the Kimchi fermentation process, it gives rise to excess acid production to reduce the taste and quality of Kimchi during storage. As a primary work to increase the keeping quality using virulent Lactobaillus plantarum bacteriophages, it was isolated sucessfully from collected Kimchi samples and their characteristics were studied. The new isolated phage, named SC 921, adsorbed to its host without Ca$^{2+}$, and nearly eliminated at 60$\circ $C of heat treatment for 5 min. This phages were atable at pH 4~ 10 but inactivated below pH 3.0 or pH 11.0 above. The latent period, rise period, and burst size of this phage was 100 min, 120 min, 31$\pm $2pfu/ml, respectively. Electron micrograph showed the phages particles were unusually oval feature of head (dia 80~ 120 nm) without contractile tail.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.282-282
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• 1996

The purpose of this study was to prepare the nifedipine dry elixir (NDE) and coated nifedipine dry elixir (CNDE) containing nifedipine ethanol solution for improving the dissolution rate and bioavailability of nifedipine. NDE containing nifedipine and ethanol in wall materials of dextrin was prepared using a spray-dryer and then NDE was coated with eudragit acrylic resin to make CNDE. Shape and size of the NDE and CNDE were monitored by scanning electron micrograph and laser particle size analyzer In vitro dissolution tests were performed in simulated gastric and intestinal fluid. Bioavailability of NDE and CNDE were compared with drug powder suspension and commercial soft capsule after oral administration of the preparations to rats. NDE and CNDE are spherical in shape. Cross-sectional view of dry elixirs indicates the large inter cavity containing ethanolic drug solution in shell. Geometric mean diameter of NDE and CNDE is about 6.64 and 8.70 $\mu\textrm{m}$, respectively. Drug dissolution rate within first 5 min from NDE increased dramatically irrespective of dissolution medium. However, CNDE showed a particularly retarded dissolution rate in pH 1.2 simulated gastric fluid compared with NDE. The bioavailability of nifedipine in the NDE was increased dramatically compared with drug powder suspension. CNDE reduced initial burst-out plasma peak compared with NDE. CNDE as a sustained release delivery system could reduce the initial burst-out plasma peak due to controlling the release rate of nifedipine from NDE and maintain the effective plasma level over a longer period within therapeutic window with enhanced bioavailability of nifedipine.

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.303-308
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• 2006

Aggregation-induced emissions of polymetalloles have been investigated since they are very attractive in their possible optoelectronic applications such as P-LED's and Sensors. Size of nanoparticulates was measured by using scanning electron micrograph and was about 200-300 nm. Phenylmethylpolysilane (PMPS) and polymetalloles emit the light at 360 nm and 520 nm, respectively. However, the aggregates of polymetallole containing PMPS exhibit an enhanced emission band at 520 nm, indicating that the energy transfer occurs from PMPS to polymetalloles in aggregates. Emission intensity of PMPS/polymetallole nanoparticulates at 520 nm increases depending on the aliquot of PMPS.

• Journal of the Korean Society for Heat Treatment
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• v.20 no.5
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• pp.231-236
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• 2007

High velocity oxy-fuel (HVOF) spraying was used to coat Ti(Al,O)/$Al_2O_3$ powder onto the SS41 steel plate. Macrostructure of the coated specimen has been investigated by scanning electron micrograph (SEM). High temperature oxidation behavior of the coated specimen and SS41 steel have been studied. From the results of SEM observation, Ti(Al,O)/$Al_2O_3$ powder was coated well onto the substrate SS41 steel. Porosity onto the coated layer was only 0.38%. The oxidation results showed that Ti(Al,O)/$Al_2O_3$ powder coated SS41 steel have improved little oxidation resistance at $900^{\circ}C$ in air, but improved remarkably oxidation resistance at $800^{\circ}C $ in air compare to the substrate SS41 steel.

• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.305-311
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• 2002

In order to evaluate the effect of poloxamer 407 content on the dissolution profiles of pellets, diltiazem HCl (DTL) core pellets were prepared with poloxamer 407 (50-90% w/w, with lactose as filler) using an extruder and a spheronizer. Any possible interaction between the drug and excipients was evaluated using DSC, IR and TLC. Dissolution tests were performed using USP basket method. In addition, scanning electron micrograph was performed to examine the surface roughness and cross sections. The release of DTL from the core pellets was decreased with increasing poloxamer 407 content. Cracks appeared on the surface of the core pellets with increasing the poloxamer 407 content, which may play a role on the retardation of the release of DTL from core pellets. There was no any significant interaction between the drug and excipients employed to prepare the core pellets.

• Journal of Pharmaceutical Investigation
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• v.13 no.1
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• pp.1-9
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• 1983

The effect of humidity on crystallization and polymorphic transformation of hydrous aluminum oxide under various humidity at $37^{\circ}$ was examined by means of X-ray diffraction, scanning electron micrograph, IR spectra and DTA. The humidity was an important factor influencing crystallization of hydrous aluminum oxide. The growth or crystal was strongly accelerated by humidity. The aging process is assumed that it is composed of two seperate steps, an increase of the diffraction around $36{\sim}42^{\circ}$, and an appearance and its development of the peak at $18{\sim}20^{\circ}$ of $2{\theta}$ value. The former is considered to be nucleation and the latter correspond to the growth period on crystallization. The crystalline form of aging products was various depending on the degree of humidity, directly it leads to the eventual formation of bayerite in more than 72%, $b{\"{o}}hmite$ in 50% and resembled to Nordstandite in 0% relative humidity, respectively but once formed, it was mostly stable in each surroundings and does not transform to the other more stable form in solid state even after aging for five years. The mechanism responsible for aging is further polymerization process of six-membered rings by deprotonation-dehydration reaction in which positively charged polynuclear hydroxy aluminum complexes formed in the presence of moisture are joined at their edges by double hydroxide bridges.

• Journal of Welding and Joining
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• v.21 no.2
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• pp.97-101
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• 2003

The change of microstructures in the base metal during transient liquid phase bonding process of directionally Ni base superalloy, GID-111 was investigated. Bonds were fabricated using a series of holding times(0~7.2ks) at three different temperatures. The flip chip bonding utilizing self-aligning characteristic of solder becomes mandatory to meet tolerances for the optical device. In this paper, a parametric study of aging condition and pad size of samples was evaluated. A TiW/Cu/electroplated Cu UBM structure was selected and the samples were aging treated to analyze the effect of intermetallic compounds with the time variations. An FIB technique was applied to the preparation of samples for TEM observations. An FIB technique is very useful to prepare TEM thin foil specimens from the solder joint interface. After aging treatment, the tendency to decrease in shear strength was measured and the structure of the solder and the UBM was observed by using SEM, TEM and EDS. As a result, the shear strength was decreased of about 21% in the 100${\mu}{\textrm}{m}$ sample at 17$0^{\circ}C$ aging compared with the maximum shear strength of the sample with the same pad size. In the case of the 12$0^{\circ}C$ aging treatment, 18% of decrease in shear strength was measured at the 100${\mu}{\textrm}{m}$ pad size sample. An intermetallic compound of Cu6Sn5 and Cu3Sn were also observed through the TEM measurement by using.

• Journal of Ginseng Research
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• v.9 no.1
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• pp.1-8
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• 1985

Preventive effect of ginseng saponin fraction against ethanol intoxication of the liver of rats fed width 12% ethanol instead of water for 6 days was investigated. Control group was dosed 12% ethanol instead of water (free access) for 6 days and test group was dosed 0.1% ginseng saponin fraction in the 12% ethanol instead of water for 6 days. Normal rats was given only water freely. It was observed that the activities of alcohol dehydrogenase (ADH) and Microsomal ethanol oxidizing system (MEOS) of both control and test groups were higher than those of normal group while the activity of aldehyde dehydrogenate (ALDH) of control and test groups were lower than that of normal rats, However, the ALDH activity decrease of test group was much less than that of control groups. Electron micrograph showed that severely swollen and disrupted mitochondria and dilated and vesiculated ER can be seen in control group while dilated or vesiculated ER are very few and swollen or disrupted mitochondria can not be seen in test group. From the above experimental result, it seems that ginseng saponin might stimulate ethanol oxidation and the removal of acetaldehyde resulting in the decrease of ethanol intoxication of the liver.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.2
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• pp.73-80
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• 2007

The preparation of oil absorbent using waste polyurethane was studied. And the effects of shape, size, and contents of waste polyurethane foam was investigated. The waste foam was treated in shape of powder, cube and bar type generated from rigid sandwich panel process. The tests for flexural strength, combustibility, and water absorptivity were carried out to investigate the mechanical and physical properties of the recycled foams. And the cell microstructure was evaluated through Scanning Electron Micrograph. The recycled foam containing powder-shaped underfilled and showed poor properties that was generated through reactivity of the resins and increasing of slurry viscosity. For the recycled foam with the cube and bar-shaped, the underfilling was caused by interference between the waste PUFs and increasing surface areas of PUF. Low cell density, non-uniformity of cell shape and size, and low adhesion of the boundary surface (new/recycled) was showed as a result of the poor properties. Considering underfilling and the properties of PUF (new/recycled), maximum recycle contents were less than 20 wt% for the powder and above 40 wt% for the cube and bar.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.201-204
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• 2007

A novel self-humidifying composite membrane for the proton exchange membrane fuel cell (PEMFC) at low humidity condition was developed. The $Pt/TiO_2 catalyst particles were synthesized via supercritical impregnation methods. Pt precursor was dissolved in supercritical carbon dioxide and impregnated onto $TiO_2$ particles. Pt precursors were platinum(II) acetylacetonate, Dimethyl(1,5-cyclooctadiene) platinum(II) and we controlled the ratio of Pt to $TiO_2$ The impregnated Pt precursor was converted to $TiO_2$ supported Pt nanoparticle under various reducing conditions. $TiO_2$ catalyst particles were dispersed uniformly into the Nafion solution, and then $Pt/TiO_2/Nafion$composite membrane was prepared using solution-cast method. The size, dispersion and content of the platinum had been characterized with Transmission Electron Micrograph (TEM), X-ray diffract ion (XRD) and Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES). The cell performance with the self-humidifying composite membrane was compared with a recast Nafion membrane under both humidified and dry conditions at 65 $^{\circ}C$.