• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.225-232
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• 1990

The immune responses of commercial layer chickens against Newcastle disease (ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were devided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$ live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were challenged with virulent ND virus at the dose of 10$^{5}$ EID$_{50}$ per bird to examine the pretection rate. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age to determine hemagglutination inhibition antibody titer. The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than 10$^{2.5}$ EID$_{50}$ per bird. Spray method gave better protection compared to eye instillation of drinking water method which resulted in lowest response. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(36%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs. When birds were challenged majority showed clinical signs on ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression (96%), drowsy(90%), anorexia (84%), diarrhoea (29%), difficult breath (15%) and torticollis (10%). Hemorrhagic lesions on post mortem were seen in duodenum (51%), trachea(35%), illeum (13%), ceacal tonsil (11%), proventriculus (10%) and some other organs.

• Korean Journal of Materials Research
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• v.27 no.7
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• pp.392-397
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• 2017

Fluorine-doped tin oxide (FTO) coated NiCrAl alloy foam is fabricated using ultrasonic spray pyrolysis deposition (USPD). To confirm the influence of the FTO layer on the NiCrAl alloy foam, we investigated the structural, chemical, and morphological properties and chemical resistance by using USPD to adjust the FTO coating time (12, 18, and 24 min). As a result, when an FTO layer was coated for 24 min on NiCrAl alloy foam, it was found to have an enhanced chemical resistance compared to those of the other samples. This improvement in the chemical resistance of using USPD NiAlCr alloy foam can be the result of the existence of an FTO layer, which can act as a protection layer between the NiAlCr alloy foam and the electrolyte and also the result of the increased thickness of the FTO layer, which enhances the diffusion length of the metal ion.

• Structural Engineering and Mechanics
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• v.77 no.1
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• pp.137-149
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• 2021

In engineering design, the axial equivalent elastic modulus of laminated FRP pipe was mostly calculated by the average elastic modulus method or the classical laminated plate theory method, which are based on relatively simplified assumptions, and may be not accurate enough sometimes. A new analytical calculation method for the axial equivalent elastic modulus of laminated FRP pipe was established based on three-dimensional stress state. By comparing the results calculated by this method with those by the above two traditional analytical methods and the finite element method, it is found that this method for the axial equivalent elastic modulus fits well not only for thin-walled pipes with orthotropic layers, but also for thick-walled pipes with arbitrary layers. Besides, the influence of the layer stacking on the axial equivalent elastic modulus was studied with this method. It is found that a proper content of circumferential layer is beneficial for improving the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers, and then can reduce its material quantity under the premise that its axial stiffness remains unchanged. Finally, the meso-mechanical mechanism of this effect was analyzed. The improving effect of circumferential layer on the axial equivalent elastic modulus of the laminated FRP pipe with oblique layers is mainly because that, the circumferential fibers can restrain the rigid body rotations of the oblique fibers, which tend to cause the significant deformations of the pipe wall units and the relatively low axial equivalent elastic modulus of the pipe.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.1-9
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• 2020

This study analyzes contaminant movement under transient flow in a rubble mound revetment offshore waste landfill barrier system that prevents contaminant runoff. The barrier system consists of bottom layer and side barrier. For the bottom layer system, impermeable clay layer is used. For the side barrier system, the HDPE barrier sheet (primary element) plays the main role, and the intermediate protection layer (supplementary element) is responsible for the barrier. Seepage, advection, dispersion numerical analysis was carried out using SEEP / W and CTRAN / W programs. As a result, under abnormal conditions considering the fluctuation in tidal range, the volume and direction of the flow velocity vector of the pore water change with time and the dispersion concentration of the contaminant changes. When comparing the case of 2 m tidal range and 8 m tidal range, the larger the tide value, the higher the concentration of contaminant under abnormal conditions. It was found that the rate of change of the concentration of the contaminant changed depending on the change in the tidal range, and as a result, the outflow of the pollutant was smaller than that in the steady flow state.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.601-608
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• 2014

In this paper, we have characterized the electrical properties related to gate leakage current in AlGaN/GaN MISHFETs with varying the thickness (0 to 10 nm) of $Al_2O_3$ gate insulator which also serves as a surface protection layer during high-temperature RTP. The sheet resistance of the unprotected TLM pattern after RTP was rapidly increased to $1323{\Omega}/{\square}$ from the value of $400{\Omega}/{\square}$ of the as-grown sample due to thermal damage during high temperature RTP. On the other hand, the sheet resistances of the TLM pattern protected with thin $Al_2O_3$ layer (when its thickness is larger than 5 nm) were slightly decreased after high-temperature RTP since the deposited $Al_2O_3$ layer effectively neutralizes the acceptor-like states on the surface of AlGaN layer which in turn increases the 2DEG density. AlGaN/GaN MISHFET with 8 nm-thick $Al_2O_3$ gate insulator exhibited extremely low gate leakage current of $10^{-9}A/mm$, which led to superior device performances such as a very low subthreshold swing (SS) of 80 mV/dec and high $I_{on}/I_{off}$ ratio of ${\sim}10^{10}$. The PF emission and FN tunneling models were used to characterize the gate leakage currents of the devices. The device with 5 nm-thick $Al_2O_3$ layer exhibited both PF emission and FN tunneling at relatively lower gate voltages compared to that with 8 nm-thick $Al_2O_3$ layer due to thinner $Al_2O_3$ layer, as expected. The device with 10 nm-thick $Al_2O_3$ layer, however, showed very high gate leakage current of $5.5{\times}10^{-4}A/mm$ due to poly-crystallization of the $Al_2O_3$ layer during the high-temperature RTP, which led to very poor performances.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.26-32
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• 2014

This study was conducted to examine the effects of eggshell membrane hydrolysates (ESMH) on the anti-inflammatory, anti-wrinkle, anti-microbial activity, and moisture-protection for cosmetic use. Whole ESMH (before fractionation), and fraction I (>10 kDa), fraction II (3-10 kDa), and fraction III (<3 kDa) of the hydrolysates were assessed in this experiment. As lipopolysaccharide (LPS) and IFN-${\gamma}$ caused the inflammation on Raw264.7 cell, whole ESMH and fraction I showed to be effective in inhibiting the induction of cell inflammation depending on the concentration, and also showed outstanding effect to suppress the skin inflammation. Fraction I inhibited collagenase and elastase activities to a greater extent than the other fractions, while all fractions had antibiotic effects at concentrations of 10 mg/disc and 20 mg/disc. In addition, it showed the moisture protection effects of skin on the holding amount and losing amount of moisture in upper-inner arm of the human body with a relatively low loss rate in skin, which confirmed that the hydrolyzed fractions of ESM helps to form the superior protective layer of moisture. It was concluded that ESMH fractions with different molecular weights, especially the 10 kDa fraction, have anti-lipopolysaccharide, anti-IFN-${\gamma}$-induced inflammation, anti-collagenase and elastase activities, and thus can be used as a cosmetic agent to protect skin.

• Transactions on Electrical and Electronic Materials
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• v.14 no.1
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• pp.47-51
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• 2013

A high power MOSFET switch based on a 0.35 ${\mu}m$ CMOS process has been developed for the protection IC of a rechargeable battery. In this process, a vertical double diffused MOS (VDMOS) using 3 ${\mu}m$-thick epi-taxy layer is integrated with a Zener diode. The p-n+Zener diode is fabricated on top of the VDMOS and used to protect the VDMOS from high voltage switching and electrostatic discharge voltage. A fully integrated digital circuit with power devices has also been developed for a rechargeable battery. The experiment indicates that both breakdown voltage and leakage current depend on the doping concentration of the Zener diode. The dependency of the breakdown voltage on doping concentration is in a trade-off relationship with that of the leakage current. The breakdown voltage is obtained to exceed 14 V and the leakage current is controlled under 0.5 ${\mu}A$. The proposed integrated module with the application of the power MOSFET indicates the high performance of the protection IC, where the overcharge delay time and detection voltage are controlled within 1.1 s and 4.2 V, respectively.

• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.606-617
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• 2019

The present study newly developed a firefighters' protective jacket and pants using a Nomex honeycomb structured layer (HPC) in cases of being exposed to flashover or flameover. This study evaluated the protective and comfort functions of an HPC compared to the current KFI firefighters' protective clothing (FPC). The results are as follows. First, thermal protective performance (TPP) of fabric layers was 2.75 times greater for HPC than FPC at $125kW/m^2$. Second, the predicted second and third degree burn areas were smaller for HPC than FPC when using a flame manikin. Third, thermal insulation using a thermal manikin was 0.2 clo greater for HPC than FPC. Fourth, there were no marked differences in maximal performance, mobility, and microclimate temperature/humidity between FPC and HPC through human wear trials. The thermal insulation of HPC was higher than that of FPC; however, any negative effect of HPC thermal insulation on the comfort functions for firefighters was not found. In conclusion, the newly-developed HPC provided more protection in reducing burn injuries from $125kW/m^2$, while no negative impact on maximal performance, mobility and thermal comfort functions of firefighters, which is appropriate for quick-evasive tactics at the flashover, flameover or back draft fires.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.81-89
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• 1999

The fabrication process for miniaturizing the Electronic Article Surveillance (EAS) sensor was studied using micromachining technique. Two types of sensor structure, free standing membrane type and diving beard type, were proposed and researched for establishing the fabrication process. The membrane type structure was easy to change the sensor shape but had the limitation for miniaturizing, because the size of the sensor depends on the silicon substrate thickness. The diving board type structure has the advantage of miniaturization and of free motion. Since the elastic modulus is not trio high, SiN film is expected to be adequate for the supporting membrane of magnetic sensor. The selectivity of $H_2O_2$for sputtered W with respect to Fe-B-Si, which was studded for magnetic sensor materials, was high enough to be removed after using as a protection layer. Therefore, the diving board type process using the silicon nitride film for the supporter of the sensor material and the sputtered W for protection layer is expected to be useful fur miniaturizing the Electronic Article Surveillance (EAS) sensor.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.750-754
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• 2014

Quantitative risk analysis has been performed for a pervaporation process for production of high test peroxide. Potential main accidents are explosion and fire caused by a decomposition reaction. As the target process has a laboratory scale, the consequence is considered to belong to Category 3. An event tree has been developed as a model for occurrence of a decomposition reaction in the target process. The probability functions of the accident causes have been established based on the frequency data of similar events. Using the constructed model, the failure rate has been calculated. The result indicates that additional safety devices are required in order to achieve an acceptable risk level, i.e. an accident frequency less than $10^{-4}/yr$. Therefore, a layer of protection analysis has been applied. As a result, it is suggested to introduce inherently safer design to avoid catalytic reaction, a safety instrumented function to prevent overheating, and a relief system that prevents explosion even if a decomposition reaction occurs. The proposed method is expected to contribute to developing safety management systems for various chemical processes including concentration of hydrogen peroxide.