• Korean Journal of Materials Research
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• v.34 no.4
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• pp.185-193
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• 2024

In this study, NASICON-type Li_1+XGa_XTi_2-X(PO₄)₃ (x = 0.1, 0.3 and 0.4) solid-state electrolytes for all-solid-state batteries were synthesized through the sol-gel method. In addition, the influence on the ion conductivity of solid-state electrolytes when partially substituted for Ti⁴⁺ (0.61Å) site to Ga³⁺ (0.62Å) of trivalent cations was investigated. The obtained precursor was heat treated at 450 ℃, and a single crystalline phase of Li_1+XGa_XTi_2-X(PO₄)₃ systems was obtained at a calcination temperature above 650 ℃. Additionally, the calcinated powders were pelletized and sintered at temperatures from 800 ℃ to 1,000 ℃ at 100 ℃ intervals. The synthesized powder and sintered bodies of Li_1+XGa_XTi_2-X(PO₄)₃ were characterized using TG-DTA, XRD, XPS and FE-SEM. The ionic conduction properties as solid-state electrolytes were investigated by AC impedance. As a result, Li_1+XGa_XTi_2-X(PO₄)₃ was successfully produced in all cases. However, a GaPO₄ impurity was formed due to the high sintering temperatures and high Ga content. The crystallinity of Li_1+XGa_XTi_2-X(PO₄)₃ increased with the sintering temperature as evidenced by FE-SEM observations, which demonstrated that the edges of the larger cube-shaped grains become sharper with increases in the sintering temperature. In samples with high sintering temperatures at 1,000 ℃ and high Ga content above 0.3, coarsening of grains occurred. This resulted in the formation of many grain boundaries, leading to low sinterability. These two factors, the impurity and grain boundary, have an enormous impact on the properties of Li_1+XGa_XTi_2-X(PO₄)₃. The Li_1.3Ga_0.3Ti_1.7(PO₄)₃ pellet sintered at 900 ℃ was denser than those sintered at other conditions, showing the highest total ion conductivity of 7.66 × 10^-5 S/cm at room temperature. The total activation energy of Li-ion transport for the Li_1.3Ga_0.3Ti_1.7(PO₄)₃ solid-state electrolyte was estimated to be as low as 0.36 eV. Although the Li_1+XGa_XTi_2-X(PO₄)₃ sintered at 1,000 ℃ had a relatively high apparent density, it had less total ionic conductivity due to an increase in the grain-boundary resistance with coarse grains.

• Journal of Physiology & Pathology in Korean Medicine
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• v.32 no.4
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• pp.255-260
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• 2018

Chung-Sang (CS) is an experimental herbal remedy that is formulated to treat respiratory diseases implicated by inflammation. The herbs comprised of CS are frequently prescribed for treating various inflammatory symptoms: Menthae haplocalycis Herba, Magnoliae Flosis, Xanthii Fructus, Herba Asari, and Caryphylli Flos. Here, we prepared the extract of CS with boiling water (wCS) or with 50 % ethanol (eCS) and examined whether the two different extracts of CS exhibit a toxicity to cultured cells and mice. RAW 264.7 cells were treated with wCS or eCS, and the cytotoxicity of these extracts to RAW 264.7 cells was determined by an MTT assay. Although the production of intracellular reactive oxygen species that are detrimental to the cells was not increased by the extracts, the cytotoxicity to the cells was evident from 10 mg/ml of wCS and 100 mg/ml of eCS, suggesting that eCS is less cytotoxic. When mice (n = 10/group) received a single intratracheal wCS or eCS daily for 14 days, wCS yielded 40 % mortality, whereas eCS showed none. Both wCS and eCS did not significantly affect the weight of the body and of vital organs, except the lung. Biochemical analyses of mice blood indicated no damage to liver or kidney. However, unlike eCS, wCS significantly increased the level of IgE in serum. Collectively, our results show that eCS was less toxic than wCS, suggesting that CS prepared with 50 % ethanol is preferential over the conventional way of preparing CS.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.106-106
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• 2003

Human papillomavirus type 16(HPV16) has been known to the major factor for the development of uterine cervical carcinomas. We have extended these studies to investigate the in vivo activities of HPV-16 E6/E7 when expressed in squamous epithelia of transgenic mice. Grossly, hK14HPV16E6/E7 transgenic mice had multiple phenotypes, including wrinkled skin that was apparent prior to the appearance of hair on neonates, thickened ears, and loss of hair in adults. In the transgenic mice, the wrinkled skin phenotype on the body and legs died at the age of 3-4 weeks. Histological analysis of demonstrated that E6/E7 causes epidermal hyperplasia in multiple transgenic lineages with high penetrance. This epithelial hyperplasia was characterized by an expansion of the proliferating compartment and an expansion of the keratinocyte and was associated with hyperkeratosis. These transgenic mice expressed E6/E7 transgene mainly in skin, heart, pancreas and kidney. Hyperplasia was found at the skin. The enzyme activities of GR, GPx and CuZnSOD were measured from the transgene cause keratinocyte at the skin. The specific enzyme activities were significantly higher in transgenic mice skin compared to the normal mice skin. Thus these transgenic mice may be useful for the develpment of antioxidant enzymes or other therapies for HPV-associated hyperkeratosis.

• Journal of Korean Theatre Studies Association
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• no.53
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• pp.203-233
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• 2014

Depuis les $ann{\acute{e}}es$ 1990, sous l'influence de la $pens{\acute{e}}e$ postmoderne, des ${\oe}uvres$ $d{\acute{e}}constructivistes$ ont fait leur apparition dans le $th{\acute{e}}{\hat{a}}tre$ $cor{\acute{e}}en$. Cependant, cette approche est plus remarquable dans le domaine du $th{\acute{e}}{\hat{a}}tre$ pratique que dans celui de $l^{\prime}{\acute{e}}criture$ dramatique. Par exemple, ce mouvement a $commenc{\acute{e}}$ avec les metteurs en $sc{\grave{e}}ne$ OH Tae-suk et GUI Gook-seo au $d{\acute{e}}but$ des $ann{\acute{e}}es$ 1990. Leur ont $succ{\acute{e}}d{\acute{e}}$ ensuite les metteurs en $sc{\grave{e}}ne$ CHOI Yong-hoon, de la troupe de $th{\acute{e}}{\hat{a}}tre$ Chak Eun Shin Hwa, et PARK Kun-hyung. De plus, actuellement, de jeunes metteurs en $sc{\grave{e}}ne$ travaillent avec $perspicacit{\acute{e}}$, tels que KO Sung-woong, KANG Lyang-won et YOUN Han-sol. A $l^{\prime}oppos{\acute{e}}$ de ce $th{\acute{e}}{\hat{a}}tre$ pratique, $l^{\prime}{\acute{e}}criture$ dramatique des $pi{\grave{e}}ces$ de $th{\acute{e}}{\hat{a}}tre$ demeure au niveau de $l^{\prime}{\acute{e}}criture$ $repr{\acute{e}}sentative$ et est encore sans grande valeur. Pour $r{\acute{e}}fl{\acute{e}}chir$ ${\grave{a}}$ ce $probl{\grave{e}}me$, nous $consid{\acute{e}}rerons$ les $pi{\grave{e}}ces$ de Michel Vinaver dont la dramaturgie oppose $l^{\prime}{\acute{e}}criture$ $d{\acute{e}}constructiviste$ au principe $repr{\acute{e}}sentatif$ et ${\grave{a}}$ $l^{\prime}{\acute{e}}criture$ traditionnelle en ${\acute{e}}chappant$ au principe de $causalit{\acute{e}}$. Avec sa $strat{\acute{e}}gie$ de montage $sp{\acute{e}}cifique$, il $proc{\grave{e}}de$ avec une ${\acute{e}}criture$ $fragment{\acute{e}}e$ tout en $ins{\acute{e}}rant$ des dialogues $h{\acute{e}}t{\acute{e}}rog{\grave{e}}nes$. Il trouve ainsi le silence des mots, un $pr{\acute{e}}sent$ sensible, la $mat{\acute{e}}rialit{\acute{e}}$ des mots et des images ostensives ${\grave{a}}$ travers des dialogues $juxtapos{\acute{e}}s$, une $simultan{\acute{e}}it{\acute{e}}$ et une $discontinuit{\acute{e}}$ du dialogue. En examinant ses $pi{\grave{e}}ces$ de $th{\acute{e}}{\hat{a}}tre$, nous explorons cette nouvelle ${\acute{e}}criture$ qui $r{\acute{e}}siste$ au $r{\acute{e}}gime$ dramatique de la $repr{\acute{e}}sentation$. Toutefois, nous n'encenserons pas seulement cette ${\acute{e}}criture$ postmoderne. Plus $pr{\acute{e}}cis{\acute{e}}ment$, nous $rel{\grave{e}}verons$ ses limites, dans les circonstances $pr{\acute{e}}sentes$, en $r{\acute{e}}fl{\acute{e}}chissant$ aux limites du $th{\acute{e}}{\hat{a}}tre$ postmoderne depuis le $d{\acute{e}}but$ des $ann{\acute{e}}es$ 2000. Ce faisant, nous souhaitons $d{\acute{e}}finir$ de nouvelles $possibilit{\acute{e}}s$ $esth{\acute{e}}tiques$.

• Journal of the Korean association of regional geographers
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• v.17 no.6
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• pp.738-752
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• 2011

La c$\hat{o}$te m$\acute{e}$ridionale de la Cor$\acute{e}$e du sud, et principalement la ville de Yeosu et ses environs pr$\acute{e}$sentent un int$\acute{e}$r$\hat{e}$t particulier puisque le paysage offre de nombreuses presqu'$\hat{i}$les, baies et $\hat{i}$les. Pour tirer profit de ces paysages naturels il est d'abord n$\acute{e}$ssaire de les prot$\acute{e}$ger. Malgr$\acute{e}$ la haute valeur de ces paysages naturels, ils demeurent peu connus et les analyses $\acute{e}$cotouristiques de la ville de Yeosu et ses environs sont encore incompl$\grave{e}$tes. Par ailleurs, la protection de ces paysages naturels est rendue difficile par la d$\acute{e}$sagr$\acute{e}$gation d$\hat{u}$e aux sels halo$\ddot{i}$des. Cette recherche a pour objet l'$\acute{e}$tude du tourisme physico-$\acute{e}$cologique et sa contribution au d$\acute{e}$veloppement $\acute{e}$conomique d'une r$\acute{e}$gion de Yeosu en Cor$\acute{e}$e du sud. Nous nous int$\acute{e}$ressons particuli$\grave{e}$rement au d$\acute{e}$veloppement d'une route $\acute{e}$cotouristique, aux crit$\grave{e}$res de s$\acute{e}$lection du lieu $\acute{e}$cotouristique et $\grave{a}$ la pr$\acute{e}$sentation des explications touristiques, en tenant compte de l'$\hat{i}$le de Sado et de ses paysages naturels sur le plan de l'$\acute{e}$cotourisme. Il y a plusieurs ressources $\acute{e}$cotouristiques sur l'$\hat{i}$le de Sado et dans ses environs: la plage de sable et la falaise de l'$\hat{i}$le de Sado; les traces fossiles de dinosaures, la ripple-mark et la crevasse dans le sol boueux de l'$\hat{i}$le de Joungdo; le tombolo, l'affleurement tufac$\acute{e}$ et le dyke de l'$\hat{i}$le de Silouseom; le trou provoqu$\acute{e}$ par les sels halo$\ddot{i}$des et le dyke de l'$\hat{i}$le de Jangsado; la mer ass$\acute{e}$ch$\acute{e}$e entre l'$\hat{i}$le de Naquek et l'$\hat{i}$le de Choudo. On a, g$\acute{e}$n$\acute{e}$ralement, d$\acute{e}$velopp$\acute{e}$ les reliefs li$\acute{e}$s $\grave{a}$ la couche s$\acute{e}$dimentaire et les fossiles de la derni$\grave{e}$re p$\acute{e}$riode du m$\acute{e}$sozo$\ddot{i}$que. La route $\acute{e}$cotouristique part de l'embarcad$\grave{e}$re de l'$\hat{i}$le de Sado et continue du Nord jusqu'au Sud.

• Membrane Journal
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• v.25 no.4
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• pp.332-342
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• 2015

In this study, to solve the major problem of reverse osmosis (RO) membrane, surface of reverse osmosis membrane was modified by silane-epoxy multi layer. Octyltrimethoxysilane (OcTES) was polymerized to membrane surface via cross-linking by Sol-gel method. n = 8 alkylgroup of OcTES formed the branch structure by self assembly. And for improve fouling resistance of RO membrane, Ether group of ethylene glycol diglycidyl ether (EGDE) was given to improve hydrophilicity of RO membrane surface by ring-opening. To analyze structure of RO membrane surface with FE-TEM and AFM. Membrane surface of the ridge and valley structure and the bridge structure was confirmed due to the multi-layer surface modification of OcTES and EGDE. And through the increase of the roughness, the branch structure was formed well on membrane surface. Through the XPS analysis was identified chemical structure of membrane surface. And confirmed that the hydrophilic surface modification is given to the surface of the film through a Contact angle analysis. In optimization of EGDE surface modification condition, was suitable 0.5 wt% EGDE concentraion and $70^{\circ}C$ ring-opening temperature. In result of fouling resistance test and MFI is SUL-H10, $PA-OcTES_{1.0}$, $PA-OcTES_{1.0}-EGDE_{0.5}$ 68.7, 60.4, 5.4 ($10E-8hr/mL^2$), multi-layer surface modified membrane improved fouling resistance.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.11
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• pp.63-70
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• 1999

A PLT(10) thin film has been deposited on $Pt/TiO_2/SiO_2/Si$ substrate by sol-gel method, and its switching characteristics have been investigated with various top electrode areas, input pulse voltages and loan resistances. As the external input pulse voltage increases from 2V to 5V, the switching time decreases from $0.49{\mu}s$ to $0.12{\mu}s$. The activation energy ($E_a$) obtained from the relations between the switching time and the applied pulse voltage is evaluated as 209kV/cm. The switched charge densities at 5V obtained from the hysteresis loop and the polarization switching are $11.69{\mu}C/cm^2$ and $13.02{\mu}C/cm^2$, respectively, which agree relatively well with each other and show the difference of 10%. When the top electrode area increases from TEX>$3.14{\times}10^{-4}cm^2$ to $5.03{\times}10^{-3}cm^2$ and the load resistance increases from 50${\Omega}$ to 3.3$k{\Omega}$, the switching time increases from $0.12{\mu}s$ to $1.88{\mu}s$ and from $0.12{\mu}s$ to $9.7{\mu}s$, respectively. These switching characteristics indicate that PLT(10) thin film can be well applied in nonvolatile memory devices.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.78-94
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• 2005

Purpose. The purpose of this study was to compare the effects of various surface treatments by measuring resonance frequency and histomorphometric analyses. Material and methods. In 5 adult dogs, the mandibular premolar were extracted. Six months later, 30 screw titanium implants (Dentium Co., Seoul, Korea) 6mm in length and 3.4mm in diameter, were placed in the mandibles of 5 dogs. Implants were divided into five groups following to surface treatment methods ; Group 1 is machined controls, Group 2 is sandblasted with large grit and acid-etched (SLA), Group 3 is anodized (Autoelectric Co., Korea, 660Hz, Duty10), Group 4 is hydroxyapatite(HA) coated by ion beam assisted deposition(E-beam), Group 5 is hydroxyapatite(HA) coated with Sol-gel coating process. Resonance frequency was measured implant placement immediately, and 3, 6 weeks and 10 weeks of healing perods. With the animal subject's sacrifice 10 weeks after implantation, implants were removed on bloc and histologic and computer-based histomorphometric analyses were performed. Histomorphometric analysis involved quantification of the entire bone to metal contact around the implants. Statistical analyses were performed using the SPSS for Windows (ver. 9.0 SPSS Inc.) Statistical differences were considered significant at P<0.05. Results. The results were as follows : 1) In five groups, mean value of resonance frequency analysis(RFA) were highest in group 5 (Sol-gel implant) at implantation and those of group 4 (E-beam)was highest at 10 weeks . but there was no correlation between surface treatments and RFA. 2) In all surface treatment groups, the RFA values of implants decreased until 3 weeks and increased to 10 weeks. 3) The percentage of direct bone-to-implant contact (BIC) had statistical significance between five groups in cancellous bone, (P<0.05) the percentage of bone density inside the thread had no statistical significance between five groups. (P>0.05) 4) There was a significant difference between cortical bone and cancellous bone in BIC. (P<0.05) and bone density. (P<0.05) 5) There was a correlation between the RFA value of implants at 10 weeks and BIC in cancellous bone, and between the RFA value of implants at 10 weeks and bone density in cortical bone. (P<0.05). Conclusions. These results indicate that surface treatment does not affect the implant stability in case of good bone quality.

• Journal of the Korean Magnetics Society
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• v.19 no.3
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• pp.113-119
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• 2009

$^{57}Fe_xCu_{1-x}O$(x = 0.0, 0.02) powders were prepared by sol-gel method and their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction and $M{\ddot{o}}ssbauer$ spectroscopy (MS). The crystal structure of the samples is found to be monoclinic without any secondary phases and their lattice parameters increase with increasing annealing temperature ($T_A$), which is attributed to an increase in oxygen-vacancy content. MS measurements at room temperature indicate that $Fe^{3+}$ ions substitute $Cu^{2+}$ sites and ferromagnetic phase grow with increasing $T_A$. Magnetic hyperfine and quadrupole interactions of $^{57}Fe_{0.02}Cu_{0.98}O$ ($T_A=500^{\circ}C$) in the antiferromagnetic state at 17 K have been studied, yielding the following results: $H_{hf}=426.94\;kOe$, ${\Delta}E_Q=-3.67\;mm/s$, I.S.=0.32 mm/s, ${\theta}=65^{\circ}$, ${\phi}=0^{\circ}$, and ${\eta}=0.6$.

• 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.