• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.95-103
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• 1998

Acute and chronic responses to PCB toxicity of Neomysis awatschensis were studied by measurement of bioassay, growth, oxygen consumption and nitrogen excretion with concentrations of PCB at 10 and $20^{\circ}C$. 96 hr.-$LC_50$ at 10 and $20^{\circ}C$ were 28.7492 pub and 10.6742 pub, respectively. Survival rates during 60 days exposured to chronic PCB concentrations of 0.5 pub, 1.0 pub, 1.5 pub and 2,0 pub at $10^{\circ}C$ were $85\%,\;80\%,\;75\%$ and $75\%$, respectively and suwival rates at $20^{\circ}C$ $85\%,\;75\%,\;75\%$ and $65\%$, respectively. Average daily growth rate of N. awatschensis exposed to chronic PCB concentrations at $10^{\circ}C$ were 0.039 mm/day in control group and 0.036 mm/day at concentration of 2.0 ppb, while their rates at $20^{\circ}C$ showed 0.072 mm/day in central group and 0.039 mm/day at 2,0 ppb. The growth factors were some similarities between the chronic PCB concentrations, but intermolt periods were related to body size of mysids, temperature and PCB toxicity. Changes in oxygen consumption and nitrogen excretion rates during 60 days exposure to PCB toxicity showed higher in high groups of PCB concentrations. Assimilation and feeding rates of N. awatschensis fed Artemia sp. decreased with increase of PCB concentration at 10 and $20^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.315-321
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• 2005

Chip-on-glass technology to attach IC chip directly on the glass substrate of flat panel display was studied by using induction heating body in AC magnetic field. With applying magnetic field of 230 Oe at 14 kHz, the temperature of an induction heating body made with Cu electrodeposited film of 5 mm${\times}$5 mm size and $600{\mu}m$ thickness reached to $250^{\circ}C$ within 60 seconds. However, the temperature of the glass substrate was maintained below $100^{\circ}C$ at a distance larger than 2 mm from the Cu induction heating body. COG bonding was successfully accomplished with reflow of Sn-3.5Ag solder bumps by applying magnetic field of 230 Oe at 14 kHz for 120 seconds to a Cu induction heating body of 5mm${\times}$5mm size and $600{\mu}m$ thickness.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.267-273
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• 2014

This research has carried out to make a data base of taxonomic research. That Data base explains about spawning behavior, egg development, and morphologic development of variable sabretooth blenny. Fertilized egg was demersal egg which is white and opaque. The number of oil glouble were 10~11, and the size of egg was 0.90~1.43 mm (average rate $1.11{\pm}0.23mm$, n=10). Breeding water temperature was $25.5{\sim}28.5^{\circ}C$ (average rate $27.0^{\circ}C$), and salinity was 32.5~33.5‰ (average rate 33.0‰). After 24 hours from 2 cells, the process of egg development was reached to Blastula stage. Moreover, after 330 hours from 2 cells, nostrils and eyes were formed. Egg membrane was pierced by the head, and the hatch began. After the hatch, postlarvae had 2.59~3.02 mm (average rate $2.81{\pm}0.25mm$, n=5) of whole length, and the mouth and anus were opened. Yolk sac and oil glouble were absorbed. After three days from hatch, prelarvae were 3.02~3.07mm(average rate $3.04{\pm}0.04mm$) of whole length, and caudal fin was grown with round shape. After 13 days from hatch, prelarvae had 3.04~3.20 mm (average rate $3.12{\pm}0.11mm$) of whole length, and they could eat food with upper jaw and bottom jaw.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.1-14
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• 1997

The purpose of this study was to investigate the physical effect of tissue conditioner on polymerized acrylic resins. Surface hardness and transverse strength were measured for evaluating physical effect of tissue conditioner on polymerized acrylic resins. 1) To measured surface hardness, the resin specimens($65{\times}10{\times}10mm$ size) of each resin material were made, applied tissue conditioner, stored in $37^{\circ}C$ water for 1 week, and changed tissue conditioner every week for 3 weeks. Surface hardness was measured every week with Shore hardness tester for 4 weeks. 2) To measured transverse strength, the resin specimens($65{\times}10{\times}3mm$ size & $65{\times}10{\times}1.5mm$) of each resin material were made. The specimens were divided into four groups, and measured by universial testing machine. Group I(control group) : The resin specimens were stored in $37^{\circ}C$ water for 5 weeks. Group II : The resin specimens were stored in $37^{\circ}C$ water for 5 weeks, and relined in 1.5mm thickness with same resin. Group III : The resin specimens were stored in $37^{\circ}C$ water for 1 week, applied tissue conditioner in 1.5mm thickness, stored in $37^{\circ}C$ water for 1 week, changed tissue conditioner and water every week for 3 weeks, removed tissue conditioner, reduced 1.5mm thickness from resin surface which was applied tissue conditioner, and relined in 1.5mm thickness with same resin. The following conclusions were obtained : 1. Surface hardness changes of Vertex RS and Vertex SC were not different significantly(p>0.01). 2. Surface hardness of K-33, Tokuso rebase, and Kooliner were decreased(p<0.01). 3. With the exception of Kooliner, transverse strength of all resin materials between control group and groups which applied with tissue conditioner were not different significantly(p>0.01).

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.99-106
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• 1993

The aim of this study is to elevate the efficiency of salting with low salt concentration in order to improve the quality of salted Chinese cabbage. The efficiency of salting was tested with various sub-atmosphere(760mmHg to 0mmHg), temperature(20$^{\circ}C$ and 30$^{\circ}C$), and concentration of salt(3%, 5% and 10%). The salting efficiency was estimated by amounts of juice, calcium elution, sodium penetration and the state of tissue. The amunts of juice eleuted from Chinese cabbage was increased significantly with the decrease of atmosphere and the time to reach the highest amounts was reduced. This tendency was promoted, with increase of salinigy(from 3% to 10%)and the increase of temperature(more juice at 30$^{\circ}C$ than 20$^{\circ}C$). The amounts of eluted calcium from Chinese cabbage tissue during salting under sub-atmosphere was directly proportional to amounts of juice and was inversely proportional to penetrated sodium. The salting time was reduced with elevation of sub-atmosphere. It was desirable to take between 5.5 and 9 hours to salt under the condition of 3% of salting, 20$^{\circ}C$, and 560-0mmHg. It took between 4.4 and 5 hours under 5% of salt and between 4 and 4.5 hours under 10% of salt. However, it was undesirable because the drying phenomenon and the transparency of tissue appeared under 30$^{\circ}C$ and 160-0mmHg.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.247-252
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• 2012

Objective : The anatomical knowledge is the most important and has a direct link with success of operation in cervical spine surgery. The authors measured various cervical parameters in cadaveric dry bones and compared with previous reported results. Methods : We made 255 dry bones age from 19 to 72 years (mean, 42.3 years) that were obtained from 51 subjects in 100 subjects who donated their bodies. All measurements from C3-C7 levels were made using digital vernier calipers, standard goniometer, and self-made fix tool for two different cervical axes (canal and disc setting). We classified into 4 groups (uncinate process, vertebral body, lamina, and pedicle) and measured independently by two neurosurgeons for 28 parameters. Results : We analyzed 23970 measurements by mean value and standard deviations. In comparing with previous literatures, there are some different results. The mean values for uncinate process (UP) width ranged from 5.5 mm at C4 and 5 to 6.3 mm at C3 and C7 in men. Also, in women, the mean values for UP width ranged from 5.5 mm at C5 to 6.3 mm at C7. C7 was widest and C5 was most narrow than other levels. The antero-posterior length of UP tended to increase gradually from C3 to C6. The tip way, tip distance, and base distance of UP also showed increasing pattern from C3 to C7. Conclusion : These measurements can provide the spinal surgeons with a starting point to address bony architectures surrounding targeted soft tissues for safeguard against unintended damages during cervical operation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.3
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• pp.85-92
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• 2015

SiC crystals are well known for their true potential as high power devices and their crystal growth activity is actively carried out in domestic as well as in abroad. Until now the process to grow this crystal has been done by sublimation technique using radio frequency induction heating method. However in order to get better quality of SiC crystals, the stability of temperature is needed because SiC crystal tends to transform to other polytypes. So, the possibility of SiC crytals growth was evaluated by different heating method. This study aimed to observe whether the resistant heating method would show stable growth and better quality of SiC single crystal than that of RF induction heating. As a result, polycrystalline SiC crystals were grown by the growth rate of 0.02~0.5 mm/hr under the condition of $2100{\sim}2300^{\circ}C$ at the bottom side of the crucible and 10~760 torr. The polycrystalline SiC crystals with 0.25 and 0.5 mm in thickness were grown successfully without seed and characterized by optical stereo microscopic observation.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.87-95
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• 2015

Purpose : This study presents the usefulness assessment of secondary shield for the lens exposure dose reduction during radiation treatment of peripheral orbit. Materials and Methods : We accomplished IMRT treatment plan similar with a real one through the computed treatment planning system after CT simulation using human phantom. For the secondary shield, we used Pb plate (thickness 3mm, diameter 25mm) and 3 mm tungsten eye-shield block. And we compared lens dose using OSLD between on TPS and on simulation. Also, we irradiated 200 MU(6 MV, SPD(Source to Phantom Distance)=100 cm, $F{\cdot}S\;5{\times}5cm$) on a 5cm acrylic phantom using the secondary shielding material of same condition, 3mm Pb and tungsten eye-shield block. And we carried out the same experiment using 8cm Pb block to limit effect of leakage & transmitted radiation out of irradiation field. We attached OSLD with a 1cm away from the field at the side of phantom and applied a 3mm bolus equivalent to the thickness of eyelid. Results : Using human phantom, the Lens dose on IMRT treatment plan is 315.9cGy and the real measurement value is 216.7cGy. And after secondary shield using 3mm Pb plate and tungsten eye-shield block, each lens dose is 234.3, 224.1 cGy. The result of a experiment using acrylic phantom, each value is 5.24, 5.42 and 5.39 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Applying O.S.B out of the field, each value is 1.79, 2.00 and 2.02 cGy in case of no block, 3mm Pb plate and tungsten eye-shield block. Conclusion : When secondary shielding material is used to protect critical organ while irradiating photon, high atomic number material (like metal) that is near by critical organ can be cause of dose increase according to treatment region and beam direction because head leakage and collimator & MLC transmitted radiation are exist even if it's out of the field. The attempt of secondary shield for the decrease of exposure dose was meaningful, but untested attempt can have a reverse effect. So, a preliminary inspection through Q.A must be necessary.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.1
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• pp.29-35
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• 1998

Substrates, SiC raw materials and graphite crucibles were purified for growing the high quality 6H-SiC single crystal ingot. Especially, XRD data of raw materials were analyzed before and after purification. We have grown 6H-SiC single crystal ingot up to 33 mm in diameter and 11 mm in length and SiC wafer for using the substrate and observing the internal defects was about 33 mm in diameter and 0.5 mm in thickness. Utilizing optical microscpe and Raman spectroscopy, internal defects density and crystallinity of the SiC wafer obtained by purification processes before crystal growth were measured. As a result, micropipe density and planar defect density were 100/$\textrm{cm}^2$ and 30/$\textrm{cm}^2$ respectively. Therefore, high quality 6H-SiC single crystal could be grown because internal defects density of 6H-SiC single crystal ingot was decreased by the purification processes before crystal growth.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.161-171
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• 1994

Mesh selection analysis for the trawl net were carried out at the Southern Korean Sea and the East China Sea during the 1992-1994 years by the training ship Seabada of the National Fisheries University of Pusan, using A type (51.2mm), B type (70.2mm), C type (77.6mm), D type (88.0mm) square mesh cod-ends. The fishing trials were made using bottom trawl of the trouser type cod-end with cover net. Selection curves and selection parameters were calculated by a logistic model for Sphyraena pinguis, Pampus argenteus, Trachurus japonicus, Pagrus major, Callanthias japonicus, Trichiurus lepturus. The results obtained are summarized as follows: 1. Red barracuda : Selection range and fifty percent selection length in the A type was 115.8mm, 292.8mm, respectively. 2. Harvest fish : Each selection range and fifty percent selection length in the B. C. and D type was 37.7mm, 113.8mm : 40.1mm, 131.7mm and 64.8mm, 148.6mm, respectively. Selection parameters of master curve were : slope, 3.81 : intercept, -6.4. Optimum mesh size was 89.3mm. 3. Horse mackerel : Each selection range and fifty percent selection length in the A, B, C and D type was 43.0mm, 148.3mm : 60.7mm, 183.2mm, 214.5mm and 91.4mm, 254.9mm, respectively. Selection parameters of master curve were : slope 2.30 : intercept, -6.4. Optimum mesh size was 66.8mm. 4. Red seabrem : Selection range and fifty percent selection length in the D type was 42.7mm, 203.4mm, respectively. 5. Yellowsail red bass : Selection range and fifty percent selection length in the A type was 84.0mm, 110.6mm, respectively. 6. Hair tail : Each selection range and fifty percent selection length in the A, B and C type was 59.7mm, 176.0mm : 100.9mm, 250.7mm and 178.6mm, 307.0mm, respectively. Selection parameters of master curve were : slope, 1.54 : intercept, -5.4. Optimum mesh size was 57.5mm.