• KSBB Journal
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• v.21 no.2
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• pp.90-95
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• 2006

Escherichia coli harboring pAC-LYCO4 and pDdxs was used for lycopene production. Three wild type strains of E. coli OW1, MG1655, and W3110 were compared with DH5${\alpha}$ used before for lycopene production. Lycopene productivity of E. coli MG1655 was similar to DH5${\alpha}$ and the highest among those wild type strain. Therefore, MG1655 strain was used for random transposon and NTG mutagenesis to increase lycopene productivity. Through transposon mutation, five transposon mutants with increased lycopene productivity were obtained. It was found that genes knocked out by transposon insertion were treB in Tn1 mutant, B2436 in Tn2 mutant, and rfaH in Tn3, 4, and 5 mutants. Lycopene productivity was the highest in Tn4 mutant among the Tn mutants, which was 6-fold and 8-fold higher in lycopene concentration and content, respectively, in comparison with those obtained with wild type strain. NTG4 mutant was acquired with NTG mutation. The highest lycopene productivity of 6 mg/L and 4 mg/g DCW was obtained from the NTG4 mutant when arabinose of 0.013 mM was added for induction of dxs, rate-limiting gene of MEP pathway. The lycopene productivity of NTG4 mutant was increased 18-fold and 12-fold in lycopene concentration and content, respectively when comparing with the wild type strain.

• Journal of the Korean Ceramic Society
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• v.39 no.9
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• pp.829-834
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• 2002

Ferroelectric properties of $ErMnO_3$ thin films deposited on Si(100) substrate using Sol-gel process with metal salts were investigated. $ErMnO_3$ thin films with a (001) preferred orientation were crystallized at 800$^{\circ}C$. The $ErMnO_3$ thin film post-annealed at 800$^{\circ}C$ for 1 h showed the dielectric constant(k) of 26 and the dielectric loss(tan ${\delta}$) of 0.032 at the frequency range from 1 to 100 KHz. The grain size of $ErMnO_3$ thin film post-annealed at 800 for 1 h was 10∼30 nm. The remanent polarization($P_r$) of the $ErMnO_3$ thin films increased with increasing (001) preferred orientation. The $ErMnO_3$ thin films post-annealed at 800$^{\circ}C$ for 1 h showed the remanent polarization($P_r$) of 400 nC/$cm^2$, with the increase of post-annealing time at 800$^{\circ}C$, the coercive field($E_c$) of thin films was lowered because the dense and homogeneous thin films were obtained.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.5-14
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• 2023

In this study, LiDAR-reflective black hollow-structured silica/titania(B-HST) materials are successfully synthesized by employing the NaBH₄ reduction and etching method on silica/titania core/shell(STCS) materials, which also effectively enhance near-infrared(NIR) reflectance. Moreover, core-etched supernatant solutions are collected and recycled for the synthesis of extracted silica(e-SiO₂) process, which successfully applies as filler materials for semiconductor epoxy molding compound(EMC). In detail, B-HST materials, fabricated by the sequential experimental steps of sol-gel, reduction, and sonication-mediated etching method, manifest blackness(L^*) of 13.2 similar to black paint and excellent NIR reflectance(31.1%). Consequently, B-HST materials are successfully prepared as LiDAR-reflective black materials. Additionally, core-etched supernatant solution with silanol precursors are employed for synthesis of homogeneous silica filler materials via sol-gel method. As-synthesized silica fillers are incorporated with epoxy resin and carbon black for the preparation of semiconductor EMC. Experimentally synthesized EMC exhibits comparable mechanical-chemical properties to commercial EMC. Conclusively, this study successfully proposes designing procedure and practical experimental method for simultaneously synthesizing the NIR-reflective black materials for self-driving vehicles and EMC materials for semiconductors, which are materials suitable for the industrial 4.0 era, and presented their applicability in future industries.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.3
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• pp.161-169
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• 2017

The present study investigated the effect of the rib arrangement and a guide vane for enhancing internal cooling of the blade. Two types of rib arrangements were used in the first and second passage in parallel. Aspect ratio of the channel was 5 and a fixed Reynolds number based on hydraulic diameter was 10,000. The attack angle of rib was $60^{\circ}$, rib pitch-to-height ratio (p/e) was 10, and the rib height-to-hydraulic-diameter ratio ($e/D_h$) was 0.075. The effect of an interaction between Dean vortices and the secondary vortices from the first passage was observed. Overall, the attack angle of rib in the first passage was dominant factor to heat transfer and flow patterns in turning region. Also, the channel with a guide vane showed enhanced heat transfer at the tip surface with reducing flow separation and recirculation.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.114-118
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• 2017

While saliva can be considered as good biological fluid for monitoring biomarkers due to many advantages including its communication with blood and the non-invasive nature during its sampling, its applications to that purpose is still limited. As a part of efforts to expand the applications of saliva to the protein biomarker research, we carried out global absolute quantitation of proteins in human whole saliva (WS) by bottom-up proteomics techniques mainly based on nLC-Q-IMS-TOF employing $MS^E$. From the analyses of a pooled WS sample collected from 22 healthy Korean volunteers, 93 proteins ranging from $5.89{\times}10^1ng/mL$ (immunoglobulin heavy chain) to $1.59{\times}10^4ng/mL$ (${\alpha}-amylase$ 1) were confirmed. For the validation of the present results, human serum albumin in the same sample was quantitated by ELISA and its result was compared with that from the nLC-Q-IMS-TOF study. As a result, there was no significant difference between two results from individual approaches ($1.18{\times}10^4{\pm}0.03{\times}10^4 ng/mL$ from nLC-Q-IMS-TOF experiments vs. $1.23{\times}10^4{\pm}0.07{\times}10^4ng/mL$ from ELISA experiments, n=3, p=0.309). To our knowledge, this is the first global absolute quantitation of proteins in human whole saliva and information from the present study can be widely used as the first level reference for the discovery of new protein biomarkers from human whole saliva as well as for quantitative applications of human whole saliva proteins.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.96-103
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• 2009

Man has an unconscious desire to free oneself from everyday selves and a strong intellectual desire to see and analyze things in a different perspective. This provided a momentum for architectural design that has long been confined to its limits of modernism of being rational and objective. The ever-changing society that we live in filled with various attempts and pluralistic characteristics shows a complex set of attributes that can hardly be defined by a single term. As society moves towards an uncertain and volatile state, the boundary between literature, philosophy and art has dimmed out and converged. Such tendencies have been observable in recent establishments in architecture in the form of introducing external elements and create an alien and farfetched architectural space. Using the 'depaysement' defamiliarization method expressing irrationality and randomness, it is applied in various aspects, sharing the counter-rational structure and features of such architectural space. Hence, it is the purpose of this study to delve into the unique characteristics of depaysement through Magritte's work which reflects the unique pictorial world built under the influence of surrealism, and discover the $D\acute{e}paysement$ tendencies in modern architectural space. It is apparent in Modern architecture that, owing to the development in digital technology, it is showing process changes in design and an interfacial $D\acute{e}paysement$ effect in cyberspace, an interlace of reality and the virtual world. In this study, the focus of analysis was architectural properties such as the program, figure/spatial, material and the objective side, but due to mutual text properties, it is bound to be an overlapping analysis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.1
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• pp.25-30
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• 2019

This study was aimed to examine the synergetic effects of photochemopreventive external agents composed of inorganic ZnO and esculetin. Zinc oxide (ZnO) is widely used in sunblocks because of its excellent biostability and little toxicity. Esculetin derived from Citrus Peel has an anti-oxidative effect. We made the hollow-shaped ZnO microsphere (MS), soaked it with esculetin (EZnO). We used SKH-1 mice to measure the photodamaging effects of UVB. The mice were divided into five groups as follows; UVB nontreated group (N), vehicle (C), esculetin (E), ZnO MS (ZnO), esculetin + ZnO MS(EZno) group. Each group of samples was topically applied to the dorsal skins before the UVB irradiation. The changes of collagen fibers in the skin tissues were observed by H & E staining and Van Gieson staining. The expression of mast cells in skin tissue was observed by immunohistochemical staining of tryptase present in the mast cell granules. Expression of inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, and MMP-9, which plays an essential role in wrinkle formation, was measured by RT-PCR. Interestingly, the composition of collagen fibers was better in the EZnO applied group than in the E or ZnO group. Moreover, mast cell expression and the expression of TNF-${\alpha}$, IL-$1{\beta}$, and MMP-9 mRNA were markedly suppressed in the EZnO group, indicating that the synergetic effects of esculetin and ZnO were excellent.

• Smart Media Journal
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• v.11 no.5
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• pp.63-74
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• 2022

Initial public offering (IPO) has a legal framework for investor protection, and because there are various quantitative evaluation factors, objective analysis is possible, and various studies have been conducted. In addition, crowdfunding also has several devices to prevent indiscriminate funding as the legal system for investor protection. On the other hand, the blockchain-based cryptocurrency white paper (ICO), which has recently been in the spotlight, has ambiguous legal means and standards to protect investors and lacks quantitative evaluation methods to evaluate ICOs objectively. Therefore, this study collects online-published ICO white papers to detect fraud in ICOs, performs ICO fraud predictions based on BERT, a text embedding technique, and compares them with existing Random Forest machine learning techniques, and shows the possibility on fraud detection. Finally, this study is expected to contribute to the study of ICO fraud detection based on quantitative methods by presenting the possibility of using a quantitative approach using unstructured data to identify frauds in ICOs.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.11-17
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• 2012

Disinfection of Escherichia coli (E. coli) in drinking water was investigated by using $TiO_2$ and $TiO_2-SiO_2$ based photocatalyst prepared by sol-gel method. The disinfection test was carried out in an annular flow reactor with circulating sterile water containing the photocatalysts powder under UV-A irradiation. The disinfection activity was proportional to the anatase`s intensity of crystalline peak of the $TiO_2$ photocatalysts. 100% disinfection of E.coli without endotoxin was achieved with $TiO_2$ coated photocatalytic system under UV-A irradiation within 2 h. However, toxic endotoxine was exist in the disinfection of E.colithe under UV-C irradiation even though 100% disinfection of E.colithe within 30 min, which suggest that $TiO_2$ coated photocatalytic system with UV-A is useful tool for the disinfection of E.coli in drinking water.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.269-276
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• 2019

A colorimetric rapid detection method based on acetylcholinesterase (AChE) was developed for the analysis of organophosphorus (OP) and carbamate (CB) pesticides. The AChE catalyzes acetylthiocholine into thiocholine having (-) and (+) charges, and the (+) charge results in gold nanoparticle (GNP) aggregation. The in-activation of AChE by OP and CB has been well known. In order to optimize the colorimetric method, optimal dilution times of commercial serum containing AChE, diameter of GNP, and concentration of acetylthiocholine were tested as a key parameter. The colorimetric detection limits of the method were 7.5 ng/mL for both dimethyl amine and carbofuran pesticides in 60% ethanol. No cross-reaction to other chemicals, such as aflatoxin B1 and ochratoxin A, which can be contaminated with pesticides in agricultural products, was observed. Recoveries from lettuce, sesame leaf, and cabbage lettuce spiked with known concentrations of dimethyl amine and carbofuran were found to be ranged from 83.85 to 133.16%. These results indicated that the colorimetric rapid method based on AChE can be a useful tool for the sensitive, specific, rapid, and accurate detection of OP and CB pesticides in fresh vegetables.