• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.309-316
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• 2010

In this study, a digital particle holographic system and its application to channel-flow measurements were investigated. A double-exposure hologram recording system that is capable of recording digital holograms in a short time interval was developed. A correlation coefficient method was used to determine the focal plane of particles. The Wiener filter was used to remove noises and improve image quality. Two-threshold and image segmentation methods were used for binary image transformation. The cross-correlation method was used for particle pairing. The developed system was employed to study channel flow fields, and the axial velocities of channel flow were measured. The measurement errors are acceptable, and this proves the feasibility of using the digital particle holographic system as a good tool for flow-field measurements.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.637-641
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• 2006

We present the DC and RF characteristics of 100 nm gate length InGaAs/InAlAs/GaAs metamorphic high electron mobility transistors (MHEMTs). We fabricated the T-gate with 100 nm foot print by using a positive resist ZEP520/P (MMA-MAA)/PMMA trilayer by double exposure method. The fabricated 100 nm MHEMT with a $70\;{\mu}m$ unit gate width and two fingers were characterized through do and rf measurements. The maximum drain current density of 465 mA/mm and extrinsic transconductance $(g_m)$ of 844 mS/mm were obtained with our devices. From rf measurements, we obtained the current gain cut-off frequency $(f_T)$ of 192 GHz, and maximum oscillation frequency $(f_{max})$ 310 GHz.

• Tribology and Lubricants
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• v.31 no.6
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• pp.258-263
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• 2015

Biodiesel is an environmentally-friendly fuel with low smoke emission because it contains about 10% oxygen. Biodiesel fuel prepared by transesterification of vegetable oil or animal fats is susceptible to auto-oxidation. The rate of auto-oxidation depends on the number of methylene double bonds contained within the fatty acid methyl or ethyl ester groups. Biodiesel may be easily oxidized under several conditions, i.e., upon exposure to sunlight, temperature, oxygen environment. Maintenance of the fuel quality of biodiesel requires the development of technologies to increase the resistance of biodiesel to oxidation. Treatment with antioxidants is a promising approach for extending the shelf-life or storage time of biodiesel. The chemical properties of various amine-based antioxidants were evaluated after synthesis of the antioxidants by condensation of phenylenediamine with alkylamines at room temperature. In general, the oxidative stability can be assessed based on various experimental parameters. Such parameters may include temperature, pressure, and the flow rate of air through the samples. The Rancimat method (EN14112) was selected because it is a rapid technique that requires very little sample and provides good precision for oxidative degradation analysis. Specifically, the EN 14112 technique provides enhanced efficiency for oxidative stability evaluation when a larger ester head group is utilized. Therefore, this technique was employed for evaluation of the oxidation stability of biodiesel by the Rancimat method (EN14112).

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.102-108
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• 2019

Objectives: Esophageal squamous cell carcinoma (ESCC) is considered as a deadly medical condition that affects a growing number of people worldwide. Targeted therapy of ESCC has been suggested recently and required extensive research. With cyclin D1 as a therapeutic target, the present study aimed at evaluating the anticancer effects of doxorubicin (Dox) or Hypericum perforatum L. (HP) extract encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles on the ESCC cell line KYSE30. Methods: Nanoparticles were prepared using double emulsion method. Cytotoxicity assay was carried out to measure the anti-proliferation activity of Dox-loaded (Dox NPs) and HP-loaded nanoparticles (HP NPs) against both cancer and normal cell lines. The mRNA gene expression of cyclin D1 was evaluated to validate the cytotoxicity studies at molecular level. Results: Free drugs and nanoparticles significantly inhibited KYSE30 cells by 55-73% and slightly affected normal cells up to 29%. The IC50 of Dox NPs and HP NPs was ~ 0.04-0.06 mg/mL and ~ 0.6-0.7 mg/mL, respectively. Significant decrease occurred in cyclin D1 expression by Dox NPs and HP NPs (P < 0.05). Exposure of KYSE-30 cells to combined treatments including both Dox and HP extract significantly increased the level of cyclin D1 expression as compared to those with individual treatments (P < 0.05). Conclusion: Dox NPs and HP NPs can successfully and specifically target ESCC cells through downregulation of cyclin D1. The simultaneous use of Dox and HP extract should be avoided for the treatment of ESCC.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.39-51
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• 2023

Common bean (Phaseolus vulgaris L.) is one of the most important crops in human food production. The occurrence of diseases, such as white mold, caused by Sclerotinia sclerotiorum can limit the production of this legume. The use of Trichoderma has become an important strategy in the suppression of this disease. The aim of the present study was to evaluate the effect of volatile organic compounds (VOCs) emitted by Trichoderma azevedoi CEN1241 in five different growth periods on the severity of white mold in common bean. The in vitro assays were carried out in double-plate and split-plate, and the in vivo assays, through the exposure of the mycelia of S. sclerotiorum to the VOCs of T. azevedoi CEN1241 and subsequent inoculation in bean plants. Chemical analysis by gas chromatography coupled to mass spectrometry detected 37 VOCs produced by T. azevedoi CEN1241, covering six major chemical classes. The profile of VOCs produced by T. azevedoi CEN1241 varied according to colony age and was shown to be related to the ability of the biocontrol agent to suppress S. sclerotiorum. T. azevedoi CEN1241 VOCs reduced the size of S. sclerotiorum lesions on bean fragments in vitro and reduced disease severity in a greenhouse. This study demonstrated in a more applied way that the mechanism of antibiosis through the production of volatile compounds exerted by Trichoderma can complement other mechanisms, such as parasitism and competition, thus contributing to a better efficiency in the control of white mold in bean plants.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.417-422
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• 2008

With standard orthorectification algorithms, one can produce unacceptable structure duplication in the orthophoto due to the double projection. Because of the abrupt height differences, such structure duplication is a frequently occurred phenomenon in the dense urban area which includes multi-history buildings. Therefore, occlusion area detection especially for the urban area is a critical issue in generation of true orthophoto. This paper deals with occlusion area detection with visible height based approach from aerial imagery and LiDAR. In order to accomplish this, a grid format DSM is produced from the point clouds of LiDAR. Next, visible height based algorithm is proposed to detect the occlusion area for each camera exposure station with DSM. Finally, generation of true orthophoto is presented with DSM and previously produced occlusion maps. The proposed algorithms are applied in the Purdue campus, Indiana, USA.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1163-1175
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• 2023

Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α-EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.35-42
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• 1996

This study was carried out to investigate the effect of straw loading method and thawing protocol on the in vitro development of in vitro produced mouse blastocysts cryopreserved by vitrification. Three loading types of straw I, Il and III on loading and sealing method were made for vitrification. The ability of the solution on straw loading methods to remain vitreous during warming was tested by exposed in air for 1 to 10 s sec. and then plunged the vitrified straws into water bath at 25°C. Embryos to be vitrified were equilibrated to the 20% EG for 5min. and exposed in EFS 40 for 1min. The plug ends of Straw I and Straw II were sealed with straw powder and Straw III was treated straw powder, followed by heat sealing and then plunged into LN$_2$. The results obtained in these experiments were summarized as follows; 1) Straw I embryo column mostly changed from transparent to opaque upon thawing without exposure in air for 3-6 sec. Straw II embryo column was I improved partially but was not remained completely vitreous during warming. However, when Straw lll loading method was used, the embryo column was remained vitreous completely. 2) High survival rates and development rates of each groups (middle blastocysts and hatching blastocysts) of vitrified embryos were obtained by using Straw III loading method than Straw I method (P<0.05). And the range of s standard error was low in Straw lll method. 3) When the embryos vitrified-frozen were placed in air for 3, 5 and l0sec. and then warmed rapidly in water bath at 25$^{\circ}C$, the survival rates after 24h of culture were 72.7-87.1% and the development rates to hatching stage after 48h of culture were 34.0-48.4%. There were no significantly differences according to exposure time in air during warming. In conclusion, the present results showed that highly survival and low standard error of vitrified-frozen mouse bIastocysts were obtained by using straw lll loading, double sealing and appropriate 2 step warming method.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.520-530
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• 2011

This study was carried out to evaluate the possibility of rice double cropping in Korea by assessing the growth and yield performance of rice cultivars transplanted at the extremely-early date. When the transplanted rice seedling was exposed to low temperature below 0℃, the survival rate decreased drastically. However, short exposure to below 0℃ one or two times did not damage transplanted rice seedling so severely. Thus, the earliest transplanting in spring would be possible when minimum temperature rises above 0℃. Compared with the conventional seedling nursery tray (CSNT), seedling rearing with the potted nursery tray was more effective for increasing leaf age and seedling dry weight during nursery period. In the first rice cropping, rice cultivation with seedlings reared in PSNT showed shorter growth duration and cumulative temperature from transplanting to heading than that with seedlings reared in CSNT. The earliest heading date on July 4 in Jinbuolbyeo was earlier by two to three days than that of Dunaebyeo. If rice has not exposed to cold damage, the earliest heading date of Jinbujolbyeo can advance to June 30 or July 1. In this case, rice harvest would be possible on August 5, enabling the rice transplanting of the second rice cropping before August 10. At transplanting time with low temperature damage rice yield were less than 400 kg/10a while rice yield exceeded 400 kg/10a at transplanting time without low temperature damage.

• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.531-556
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• 1992

The majority of the commonly used protraction headgears for the protraction of small and/or retropositioned maxilla not allow a change in the point of force application or direction of the force delivery to attain predictable results because of the position of the upper and lower lips to avoid discomfort to the patient. The purpose of this study was to investigate the initial reaction of maxillofacial complex according to the change of force variables such as direction and point of force application with designing an antenna type-modified protraction head gear. A macerated human skull with well aligned upper teeth was used to experimental model and the investigation was done by double exposure holographic interferometry. Fringe patterns of each protraction conditions were compared and analized. The results were as follows. (Frontal view) 1. The Counterclockwise rotation of the maxilla was showed by parallel protraction to occlusal plane and the fringe was decreased in number as higher point of force application. 2. Generally, the number of fringe was increased in 500gm of protraction force than in 300gm. 3. When apply the protraction force to the maxilla with rapid palatal expansion, the direction of fringe patterns was differed from the protraction without expansion. 4. In most of cases, the counterclockwise rotation was decreased in case of the direction of the force is $20^{\circ}$ downward to occlusal plane compared to the parallel direction. 5. At the point of force application is 15mm above and the direction of force is 20 downward to occlusal plane , the translation of the maxillary complex was showed. (Lateral view) 6. The direction of fringe patterns of the facial bones were differed each other by the sutures, and showed almost parallel when apply the 300gm and 500gm of protraction force. 7. In case of rapid palatal expansion with protraction of the maxilla, the fringe patterns between the maxillary area and the area from the posterior of the maxillary first molar to the pterygomaxillary fissure were differed. In case without rapid palatal expansion, the changes of direction and point of the force application did not affect to the direction and the number of the fringe patterns.