• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.4
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• pp.370-377
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• 1994

DC plasma torch which is a non-transferred type was constructed and silicon nitride powders were produced. Ar gas is used as a plasma gas and gas reactants with the carrier gas are introduced beneath the plasma ignition part. Two slits are attached and a reactive quenching gas is introduced through them. Using $SiCl_4 and NH_3$ as starting materials, silicon nitride powders were produced. As-produced powders were amorphous and crystalline silicon nitrides were obtained by heating at $1420^{\circ}C$ for two hours under nitrogen atmosphere. Silicon nitride phase was identified in the XRD patterns and IR spectrum, and the image of the powders before and after heating was observed from the TEM analysis.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.85-95
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• 2009

In the binaural synthesis environments, wide varieties of the head-related transfer functions (HRTFs) that have measured with a various direction would be desirable to obtain the accurate and various spatial sound images. To reduce the size' of HRTFs, interpolation has been often employed, where the HRTF for any direction is obtained by a limited number of the representative HRTFs. In this paper, we study on the distortion measures for interpolation, which has an important role in interpolation. With lhe various objective distortion metrics, the differences between the interpolated and the measured HRTFs were computed. These were then compared and analyzed with the results from the listening tests. From the results, the objective distortion measures were selected, that reflected the perceptual differences in spatial sound image. This measure was employed in a practical interpolation technique. We applied the proposed method to four kinds of an HRTF set, measured from three human heads and one mannequin. As a result, the Mel-frequency cepstral distortion was shown to be a good predictor for the differences in spatial sound location, when three HRTF measured from human, and the time-domain signal to distortion ratio revealed good prediction results for the entire four HRTF sets.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.39-46
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• 1999

This study was performed to examine the effect of initial composition ratio and various reaction conditions on CEC and crystallinity of the product in hydrothermal synthesis of zeolitic materials from fly ash. Na-P1 zeolite was formed from the mixture with $SiO_2/Al_2O_3$ ratio above 2.55, however from the mixture with $SiO_2/Al_2O_3$ ratio below 2.25 hydroxy sodalite was formed. The CEC of reaction product(Na-P1 zeolite) treated with 3N-NaOH, $Na_2O/Al_2O_3$ ratio 2.55 and $SiO_2/Al_2O_3$ ratio 2.0 for 12 hours at $103^{\circ}C$ was about $285cmol^+kg^{-1}$, which was higher than those of the products of other reaction condition. The crystallinity of Na-P1 zeolite as high as 45.1% was attained at the optimum reaction condition of 2N-NaOH, $SiO_2/Al_2O_3$ ratio 2.55, $Na_2O/Al_2O_3$ ratio 1.5 for 12 hours at $103^{\circ}C$. The XRD peak of the reaction product could be measured at 7.16, 5.04, 4.12, 3.18, $2.69{\AA}$ and tetragonal pillar shape observed by SEM image be characteristic for Na-P1 zeolite. Judging from the result, it should be considered the optimum synthesis condition for Na-P1 zeolite from fly ash was 2~3N NaOH, $SiO_2/Al_2O_3$ ratio 2.55 and $Na_2O/Al_2O_3$ ratio 1.5~2.0 for 12 hours at $80{\sim}103^{\circ}C$.

• Journal of Veterinary Clinics
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• v.32 no.4
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• pp.295-300
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• 2015

The aim of the study was to assess the in vitro effect of 808-nm InGaAs diode laser on rabbit articular chondrocyte proliferation and sulphated glycosaminoglycan (sGAG) synthesis in alginate bead. Previous studies revealed either positive or negative stimulatory effects of laser on different types of cells. A 808-nm InGaAs diode laser at 1.0W power output was used to irradiate the rabbit chondrocytes in alginate beads with energy densities of $31J/cm^2$ (G 1) and $62J/cm^2$ (G 2) corresponding to the experimental groups for 10 seconds and 20 seconds, respectively at 24, 48, 72 and 96 hours after seeding. Control group was left untreated. MTT assay was performed at 1 week and 2 weeks after the $1^{st}$ laser irradiation in alginate beads. sGAG synthesis in alginate beads at 1 week and 2 weeks were determined by DMMB assay. Histological evaluation for cellular distribution and sGAG deposition around the cells were performed by alcian blue stain. MTT assay revealed no positive stimulatory effect in cell proliferation in alginate bead. DMMB assay results showed significantly increased sGAG production in G 2 chondrocytes at 2 weeks. Image analysis of alcian blue stained slides also showed significantly higher percentage of positive alcian blue stain in G 2 chondrocytes. This result suggests that 808-nm InGaAs diode laser with 1.0 W power output although cannot stimulate cell proliferation it can increase the cell secretion activity and sGAG deposition in alginate beads.

• Archives of design research
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• v.17 no.2
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• pp.335-350
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• 2004

Design takes concrete form from the things which are not yet exist to the molded reality. Creation of value which is accompanied by the rational value could be possible only through the searching examination of the basic concept. All designs are under circumstances because the results and the character of the problems are different under the given conditions and circumstances which are the characteristic of the design. The aim of this study is searching for the differential design conce- pt which is the most appropriate and reasonable in the basic design process in which the phase of the analysis, synthesis and evaluation of the problem. First of all the pursuit value of the times and the change of the view point of value of the product design. How the pursuit value of times were searched and analyzed. Analyze the successful product design realization of the typical trend of the modern design which are 3-2. function-focused design, 3-3. emotion-centered design, 3-4. image communicative design through the metaphor, 3-5. environmental affinity design. On the base of the case analysis how to apply the differential design concept which is coming as a trend in the future society which are sustainable developing society was examined closely. The outcome through the analysis of the success cases are as follows, \circled1 the value of the spirit of the times should be emphasized as the design image, \circled2 environmental appropriateness should be taken into consideration as the first primary factor, \circled3 the realization of value of the fulfillment of differential consumer's needs, \circled4 lead to prolong the life cycle of the product, \circled5 promote the sustaining growth of enterprise, \circled6 user-centered product value should be the first consideration. \circled7 It is necessary to overcome the cultural andinguistic barriers and to reflect the metaphor which people remember well. \circled8 The application of human's true character should be decided beforehand. It is the commonness of values of times and customs. \circled9 The differentiated design concept which meets our mental satisfaction, not material one, will be required. In addition to this the creative and differentiated design concepts which are accompanied by the good design factor under the base of product could achieve the emotional consensus from the consumers. That is, the value of all designs should be estimated by the base of the humanism ' The human beings are the barometer of all things".ngs".uot;.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.3
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• pp.177-185
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• 2006

Purpose: Purpose of this study is to synthesize $^{99m}Tc$-labeled transferrin for injection imaging and to compare it with $^{67}Ga$-titrate for the detection of infectious foci. Materials and methods: Succinimidyl 6-hydrazino-nicotinate hydrochloride-chitosan-transferrin (Transferrin) was synthesized and radiolabeled with $^{99m}Tc$. Labeling efficiencies of $^{99m}Tc$-Transferrin were determined at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 8 hr. Biodistribution and imaging studies with $^{99m}Tc$-Transferrin and $^{67}Ga$-citrate were performed in a rat abscess model induced with approximately $2{\times}10^8$ colony forming unit of Staphylococcus aureus ATCC 25923. Results: Successful synthesis of Transferrin was confirmed by mass spectrometry. Labeling efficiency of $^{99m}Tc$-Transferrin was $96.2{\pm}0.7%,\;96.4{\pm}0.5%,\;96.6{\pm}1.0%,\;96.9{\pm}0.5%,\;97.0{\pm}0.7%\;and\;95.5{\pm}0.7%$ at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 8 hr, respectively. The injected dose per tissue gram of $^{99m}Tc$-Transferrin was $0.18{\pm}0.01\;and\;0.18{\pm}0.01$ in the lesion and $0.05{\pm}0.01\;and\;0.04{\pm}0.01$ in the normal muscle, and lesion-to-normal muscle uptake ratio was $3.7{\pm}0.6\;and\;4.7{\pm}0.4$ at 30 min and 3 hr, respectively. On image, lesion-to-background ratio of $^{99m}Tc$-Transferrin was $2.18{\pm}0.03,\;2.56{\pm}0.11,\;3.08{\pm}0.18,\;3.77{\pm}0.17,\;4.70{\pm}0.45\;and\;5.59{\pm}0.40$ at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 10 hr and those of $^{67}Ga$-citrate was $3.06{\pm}0.84,\;4.12{\pm}0.54\;and\;4.55{\pm}0.74 $ at 2 hr, 24 hr and 48 hr, respectively. Conclusion: Transferrin is successfully labeled with $^{99m}Tc$, and its labeling efficiency was higher than 95% and stable for 8 hours. $^{99m}Tc$-Transferrin scintigraphy showed higher image quality in shorter time compared to $^{67}Ga$-citrate image. $^{99m}Tc$-transferrin is supposed to be useful in the detection of the infectious foci.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.93-102
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• 2008

Experimental studies were conducted to characterize the synthesized nanoscale zero-valent iron (NZVI) which is resistant to oxidation in the atmospheric environment. XRD, XPS, and TEM analyses revealed that the oxidation-resistant NZVI particles formed under various controlled air contact conditions (4, 8 and 12 mL/min) have shells with ${\sim}$5 nm thickness. The shells consist of magnetite (${Fe_3}{O_4}$) and maghemite (${\gamma}-{Fe_2}{O_3}$), predominantly. No substantial differences were found in the shell components and thickness among NZVI particles formed under the various air flow rates. On the other hand, shell was not detected in the TEM image of rapidly oxidized NZVI particles. NZVI particles synthesized under the various air flow rates showed similar TCE degradation performances ($k_{obs}$= 0.111, 0.102, and 0.086 $hr^{-1}$), which are equivalent to approximately 80% of those obtained by the fresh NZVI particles. TCE degradation efficiencies of the NZVI particles(fresh, controlled air contact and rapidly oxidized) were improved after equilibrating with water for one day, indicating that depassivation of the shells occurred. The performances of NZVI particles decreased to 90% and 50% of those of the fresh NZVI particles, when they were equilibrated with the atmosphere for a week and two months, respectively. The NZVI particles synthesized under the controlled air contact would have advantages over traditional NZVI particles in terms of practical application into the site, because of their inertness toward atmospheric oxygen.

• The Korean Journal of Nuclear Medicine
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• v.30 no.3
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• pp.344-350
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• 1996

Purpose : Noninvasive imaging of tumor cell proliferation could be helpful in the evaluation of tumor growth potential and could provide an early assessment of treatment response. Radiolabeled thymidine, uridine and adenosine have been used to evaluate tumor cell proliferation. These nucleoside analogs are incorporated into DNA during proliferation. Iodine-131-Iodomethyluridine, an analog of Iodine-131-Iododeoxyuridine, is also involved in DNA/RNA synthesis. The purpose of this study was to develop Iodine-131-Iodomethylurdine and image tumor proliferation using Iodine-131-Iodomethyluridine. Materials and Methods : Radiosynthesis of Iodine-131-5-Iodo-2'-O-methyluridine (Iodine-131-Iodomethyluridine) was prepared from 10 mg of 2'-O-methyluridine(Sigma chemical Co., St. Louis, Missouri) and 2.1 mCi(SP. 10Ci/mg) of Iodine-131-labeled sodium iodide in $100{\mu}l$ of water using iodogen reaction. Female Fischer 344 rats were inoculated in the thigh area with breast tumor cells(13765 NF, $10^5$ cells/rat S.C.). After 14 days, the Iodine-131-Iodomethyluridine $10{\mu}Ci$ was injected to three groups of rats(3/group). The percent of injected dose per gram of tissue weight was determined at 0.5-hours, 2-hours, 4-hours, and 24-hours respectively. Tumor bearing rats after receiving Iodine-131-Iodomethyluridine($50{\mu}Ci$ IV) were euthanized at 2 hours after injection. Autoradiography was done using freeze-dried $50{\mu}m$ coronal section. After injection of Iodine-131- Iodomethyluridine ($10{\mu}Ci$/rat, IV) in three breast tumor-bearing rats, planar scintigraphy was taken at 45 minutes, 90 minutes and 24 hours. Results : Iodine-131-Iodomethyluridine was conveniently synthesized using iodogen reaction. The biodistribution showed fast blood clearance and the tumor-to-tissue uptake ratios showed that optimal imaging time was at 2 hours postinjection. Autoradiogram and planar scintigram indicated that tumor could be well visualized. Conclusion : The findings suggest that Iodine-131-Iodomethyluridine, a new radio-iodinated nucleoside, has potential use for evaluation of active regions of tumor growth.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1099-1104
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• 2007

The visual implementation of 3-dimensional national environment is focused by the requirement and importance in the fields such as, national development plan, telecommunication facility deployment plan, railway construction, construction engineering, spatial city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies national geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. There it is needed to apply laser measurement technique in the spatial target object to obtain accuracy. Currently, the LiDAR data which combines the laser measurement skill and GPS has been introduced to obtain high resolution accuracy in the altitude measurement. In this paper, we first investigate the LiDAR based researches in advanced foreign countries, then we propose data a generation scheme and an algorithm for the optimal manage and synthesis of railway facility system in our 3-D spatial terrain information. For this object, LiDAR based height data transformed to DEM, and the realtime unification of the vector via digital image mapping and raster via exactness evaluation is transformed to make it possible to trace the model of generated 3-dimensional railway model with long distance for 3D tract model generation.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.1-12
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• 2003

The purpose of this study was to investigate the effect of high voltage pulsed current stimulation (HVPCS) on the healing rate of a dermal wound in a rat. We also determined the mechanism of promoting healing by HVPCS. Twenty male Sprague-Dawley rats were randomly divided into two group; HVPCS group (n=10) and control group (n=10). The HVPCS rats received electrical stimulation with a current intensity of 50 V at 100 pps for a duration of 30 minutes, while the control group was given the same treatment without electricity for a week. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with Masson's trichrome, hematoxylin and eosin (H&E). The fibroblasts and collagen density were counted using a light microscope and computerized image analysis system and calculated as the density and the percent. A Student t-test showed a significantly higher wound healing rate of the HVPCS group than control (t=-4.161, p<0.001). The fibroblasts in the HVPCS group were higher than in the control group (t=-4.921, p<0.001). The density of collagen in the HVPCS group was also higher than in the control group (t=-4.367, p<0.001). These results indicate that the HVPCS accelerated the rate of healing in dermal wound, and increased fibroblasts and collagen density in the regenerative dermis. These findings suggest that the HVPCS may activate fibroblasts by alteration of the electrical environment, and it may increase collagen synthesis in the regenerative dermal wound.