• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.69-72
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• 2021

Various studies for QLEDs using inkjet printing has been actively conducted. Multilayers in QLEDs need an orthogonal process inevitably using different solvents and it makes the inkjet printing process more difficult and expensive. Therefore, coating two layers in a single process can reduce the fabrication step, resulting in the process time. In this study, we fabricated QLEDs of standard structure using a mixture of emission layer and hole transport layer. The mixed layer was fabricated by dissolving TFB and QDs in chlorobenzene, and the maximum luminance of the device was 45,850 cd/m². It shows the bright future of the electroluminescence devices applied with inkjet printing process.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2258-2265
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• 2024

The present investigation aims to study the role of Pr₂O₃ on the structural, physical, and radiation shielding properties of a dense cadmium lead borate glass. The XRD was used to affirm the glassy amorphous structure of fabricated sample materials. Moreover, the FTIR was used to record the change in the FT-IR spectra due to the addition of Pr₂O₃ in the wavenumber interval between 400 and 4000 cm^-1. The features of glass surfaces and the elemental analyses for the synthesized Pr₂O₃-reinforced cadmium lead borate glasses were performed using a SEM, supported by an energy-dispersive spectrometer. The γ-ray protection capacity was evaluated using the Monte Carlo method in a wide energy interval ranging between 0.015 and 15 MeV. The linear attenuation coefficient (LAC) at 1 MeV was reduced by a factor of 10 % from 0.372 cm^-1 to 0.340 cm^-1. The decrease in the LAC values negatively affected the other shielding properties such as half-value thickness and the transmission factor. Although the linear attenuation coefficient is decreased slightly with the partial substitution of CdO by Pr₂O₃ compound, the fabricated glass samples still have a high shielding capacity compared to the traditional commercial glasses as well as previous similar reported glasses.

• Journal of the Korean Institute of Gas
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• v.1 no.1
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• pp.56-63
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• 1997

This paper presents a hybrid network model(HY-PIPENET) implementing a minimum cost spanning tree(MCST) network algorithm to be able to determine optimum path and constrained derivative(CD) method to select optimum Pipe diameter. The HY-PIPENET has been validated with the published data of 6-node/7-pipe network. Networking system and also this system has been optimized with MCST-CD method. As a result, it was found that the gas can be sufficiently supplied at the lower pressure with the smaller diameters of pipe compared to the original system in 6-node/7-pipe network. Hence, the construction cost was reduced about $40\%$ in the optimized system. The hybrid networking model has been also applied to a complicated domestic gas pipeline network in metropolitan area, Korea. In this simulation, parametric study was peformed to understand the role of each individual parameter such as source pressure, flow rate, and pipe diameter on the optimized network. From the results of these simulations, we have proposed the optimized network as tree-type structure with optimum pipe diameter and source pressure in metropolitan area, Korea, however, this proposed system does not consider the environmental problems or safety concerns.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.260-265
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• 2000

To determine the quality change of the irradiated eggs during storage, fresh shell eggs were irradiated using $^{60}Co$ at 0, 1, 5, 10, 30 kGy and stored for 30 days. The york index, color, pH, viscosity, egg weight, and SDS-PAGE profile of the irradiated eggs were examined. During storage, york index values of the irradiated eggs and the control were decreased and the increase of dose decreased yolk index. However, the yolk index values were increased temporarily at 10 kGy and 30 kGy. The yolk color had a bright yellow with increases in dose level and there was no significant change during storage. The albumen viscosities were decreased with increases in dosage and were decreased during storage. Also, the albumen pH values of the irradiated eggs were higher than that of the control and were increased during storage. The weight losses of eggs were increased during storage and there were no significant changes by dose level. SDS-PAGE profile of the egg white proteins of the shell eggs showed the change in molecular weight distribution and had aggregation pattern as well as degradation. CD and fluorescence spectroscopy study showed changes in the secondary and tertiary structure of egg white proteins by ${\gamma}-irradiation$. Therefore, this study clearly indicates that irradiation dose of eggs should be appropriate to prevent the loss of egg qualities.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.182-192
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• 2006

Background: Atherosclerosis has emerged as the leading cause of death in developed countries. At present, human umbilical vein endothelial cells (HUVEC) are most commonly used for the investigation of Endothelial cells (EC). However, HUVEC are not found in arteries but only in veins. Currently there are many reports on methods used to isolate EC;, most of these methods require special equipment to remove contaminating smooth muscle cells (SMC). Materials and Methods: The method described here may be used to isolate not only ECs but also SMCs;,the approach presented here did not require special equipment. Rat aorta was treated with 2 mg/ml of type II collagenase solution for 45 minutes. The isolated cells from the aorta were incubated in medium G for a week;, only ECs could be separated. After the collagenase treatment, the rest of aorta was cut lengthwise, and left undisturbed to obtain SMCs in the culture dish for 10 days. To verify the purity of the isolated cells, we performed immunofluorescence and evaluated the results with transmission electron microscopy analysis. Results: The immunofluorescence study demonstrated specific expression of CD31 and ${\alpha}$-smooth muscle actin in the isolated ECs and SMCs, respectively. Cultured ECs and SMCs showed their own fine structure characteristics. Conclusion: These results suggest that this method for isolating ECs and SMCs may be especially useful for the study of atherosclerosis.

• Korean Journal of Materials Research
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• v.30 no.10
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• pp.566-572
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• 2020

In the recent years, thin film solar cells (TFSCs) have emerged as a viable replacement for crystalline silicon solar cells and offer a variety of choices, particularly in terms of synthesis processes and substrates (rigid or flexible, metal or insulator). Among the thin-film absorber materials, SnS has great potential for the manufacturing of low-cost TFSCs due to its suitable optical and electrical properties, non-toxic nature, and earth abundancy. However, the efficiency of SnS-based solar cells is found to be in the range of 1 ~ 4 % and remains far below those of CdTe-, CIGS-, and CZTSSe-based TFSCs. Aside from the improvement in the physical properties of absorber layer, enormous efforts have been focused on the development of suitable buffer layer for SnS-based solar cells. Herein, we investigate the device performance of SnS-based TFSCs by introducing double buffer layers, in which CdS is applied as first buffer layer and ZnMgO films is employed as second buffer layer. The effect of the composition ratio (Mg/(Mg+Zn)) of RF sputtered ZnMgO films on the device performance is studied. The structural and optical properties of ZnMgO films with various Mg/(Mg+Zn) ratios are also analyzed systemically. The fabricated SnS-based TFSCs with device structure of SLG/Mo/SnS/CdS/ZnMgO/AZO/Al exhibit a highest cell efficiency of 1.84 % along with open-circuit voltage of 0.302 V, short-circuit current density of 13.55 mA cm^-2, and fill factor of 0.45 with an optimum Mg/(Mg + Zn) ratio of 0.02.

• BMB Reports
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• v.46 no.5
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• pp.282-287
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• 2013

Cecropin A and papiliocin are novel 37-residue cecropin-like antimicrobial peptides isolated from insect. We have confirmed that papiliocin possess high bacterial cell selectivity and has an ${\alpha}$-helical structure from $Lys^3$ to $Lys^{21}$ and from $Ala^{25}$ to $Val^{35}$, linked by a hinge region. In this study, we demonstrated that both peptides showed high antimicrobial activities against multi-drug resistant Gram negative bacteria as well as fungi. Interactions between these cecropin-like peptides and phospholipid membrane were studied using CD, dye leakage experiments, and NMR experiments, showing that both peptides have strong permeabilizing activities against bacterial cell membranes and fungal membranes as well as $Trp^2$ and $Phe^5$ at the N-terminal helix play an important role in attracting cecropin-like peptides to the negatively charged bacterial cell membrane. Cecropin-like peptides can be potent peptide antibiotics against multi-drug resistant Gram negative bacteria and fungi.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.36-36
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• 2011

We synthesized new dye sensor based on indole compound. Through the UV-vis absorptions, we analyzed chemosensing properties to explain metal binding properties. The peak absorptions increased at 472 nm when added metal cations($Cd^{2+}$, $Cu^{2+}$, $Hg^{2+}$, $Fe^{2+}$, $Zn^{2+}$, $Ni^{2+}$ and $Cr^{3+}$) and gradually decreased the peak at 516 nm. Thus, this UV-Vis absorption behavior clearly showed the metal binding reaction. To measure energy level of used dye sensor, HOMO/LUMO energy value was calculated with cyclovaltagramm(CV) and using computational calculation method, in which we estimated the optimum structure of dye sensor. CV and computational calculation method, both compared to find suitable geometric structure. (with almost same energy values.) From the computational calculation, dye sensor has plane structure. So, Amine and ketone in the dye sensor faced each other and makes position to bind metal cations. In addition, these positions was supported pull-push electron system and generated MLCT process, when the dye sensor was bonded with the metal cations and resulted chemosensing properties. Through the electrochemical and computational calculation method analyze, we proposed the chemosensing principles that the dye sensor bind the metal cation between ketone and amine. Finally, the formation type of metal ion bindings was determined by Job's plot measurements.

• BMB Reports
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• v.28 no.5
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• pp.437-442
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• 1995

The potency of yeast-derived methionyl-free human growth hormone (rhGH), which was obtained by removal of the N-terminal Met from methionyl-hGH, was estimated by in vitro and in vivo assays. In radio-receptor assay where the binding affinity of growth hormone to the receptor was estimated, the recombinant hGH showed 2.9 international units (IU) per mg of specific activity. In contrast, pitUitary-derived human growth hormone had a slightly lower receptor binding activity (2.5 IU/mg) compared with recombinant growth hormone. For the in vivo assay, efficacy of rhGH was tested by use of hypophysectomized rats, in which pituitary organs were surgically removed, resulting in the termination of growth hormone secretion. The weight-increase in rats by the injection of rhGH was almost identical to the result obtained by the injection of the same amount of pituitary-derived (international standard) hGH. A comparision of the secondary structures of rhGH and rMet-hGH by circular dichroism spectrophotometer demonstrated that the removal of the methionyl residue from rMet-hGH did not exert any effect on the structure of the growth hormone. In conclusion, methionyl-free human growth hormone produced from yeast was highly potent in biological activity and maintained a legitimate three dimensional structure.

• Proceedings of the Korean Printing Society Conference
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• 2001.06a
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• pp.63-77
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• 2001

PDF(Portable Document Format) is a file format that Adobe advances postscritp technique and use in managing document information or electric publishing(internet, CD-ROM, DVD). PDF is a devised document type for being able to read and print anywhere, independent of OS, printer type, resolution, and the kind of computer etc. Because this includes a compressing function, it transfers document through a small size of file in internet or intranet. In addition, that is a file format has various advantages-sharing of information and transfering documents in on line or off line environment. In this paper, we developed electronic document system using PDF format. Electronic document system consists of filter, automatic indexing, special searching system and web server. The information used in this paper is database made using Zwon\`s DocuCom. The filter recognizes various kinds of document structure. And according to property of document, it produces ASCII output. In addition to processing various formats of document, the filter can extract keywords in documents of MS WORD, Excel, Powerpoint, PDF, CAD etc. This filter uses the structure of window printer drive and can extract the information for text, page, font type and size from relevant document. The automatic indexing recognizes the formatted tag of document form ASCII text produced by filter and extracts adequate keyword to structure and property of document. PDF electronic document systems proposed in this paper can be used in Internet, PC communication. Users can choose and read electronic documents by two ways. First, users can choose and read relevant books using PDF electronic document homepage. Second, users can use PDF integrated-search system. User can search after inputing keyword and choose reference field and type of data. But, now, PDF products of Adobe can\`t support the Korean character. If this problem is resolved, we thick that PDF applications system looks active. Although there is limited function in case of using Zwon DocuCom used in this study, we think that there isn\`t a great deal of difficulty in electronic document and building digital database.