• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.7
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• pp.543-551
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• 2012

In this study, transparent conducting Al-doped Zinc Oxide (AZO) films with a thickness of 150 nm were prepared on corning glass substrate by the RF magnetron sputtering with using a Al-doped zinc oxide (AZO), ($Al_2O_3$: 2 wt%) target at room temperature. This study investigated the effect of rapid thermal annealing temperature and oxygen ambient on structural, electrical and optical properties of Al-doped zinc oxide (AZO) thin films. The films were annealed at temperatures ranging from 400 to $700^{\circ}C$ by using Rapid thermal equipment in oxygen ambient. The effect of RTA treatment on the structural properties were studied by x-ray diffraction and atomic force microscopy. It is observed that the Al-doped zinc oxide (AZO) thin film annealed at $500^{\circ}C$ at 5 minute oxygen ambient gas reveals the strongest XRD emission intensity and narrowest full width at half maximum among the temperature studied. The enhanced UV emission from the film annealed at $500^{\circ}C$ at 5 minute oxygen ambient gas is attributed to the improved crystalline quality of Al-doped zinc oxide (AZO) thin film due to the effective relaxation of residual compressive stress and achieving maximum grain size.

• Geotechnical Engineering
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• v.10 no.4
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• pp.103-118
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• 1994

The rapid motion of granular material is microscopically observed, and investigated by continuum theory. From the binary collision phenomenon two different times are introduced : flying time and contact time. The former says the non -stationary motion and at a same time the variation of bulk volume. The latter is operative by a delayed time during the contact and describes the elastic properties of granular material. With both times a dynamic constitutive equation is postulated for four state variables : dispersive pressure, viscosity, thermal diffusivity and energy annihilation rate. The balance laws of mass, momentum and energy which are represented through above four variabls, are applied to the model, in which due to the elastic property the relaxation and energy absorption are explained.

• Journal of Veterinary Clinics
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• v.18 no.1
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• pp.22-28
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• 2001

A combined anesthesia in terms of balanced anesthesia has been widely used for enhancement of anesthetic potency, decrement of dosage, reduction of side effects and better muscle relaxation. Recently, tiletamine/zolazepam (T/Z) has been widely used for the general anesthesia in dogs, but there have been few studies on balanced anesthesia of this drug in combination with other drugs. In this experiment, the combinations of T/Z with acepromazine or fentanyl/xylazine/azaperone (F/X/A) have been compared for the anesthetic effects in dogs. Healthy 5 mongrel dogs were allocated into three treatment groups ; Group Z (atropine + T/Z), Group A + Z (atropine/acepromazine + T/Z) in runs of 10 replication. The rapid induction of anesthesia was shown in all three treatment groups. The maintenance time of anesthesia was significanty increased to 101.4$\pm$6.2 minutes (44 min. more than that of group Z) in Group A + Z and 127.4$\pm$4.7 minutes (70 min. more than that of group Z) in Group F + Z, respectively. The recovery from anesthesia was rapid in Group F + Z. In blood analysis, there was no significant variation in three groups but hyperglycemia in Group F + Z. These results indicate that the balanced anesthesia of T/Z with F/X/A was superior to other two methods for maintaining and recovering from the anesthesia, and could be applied for general anesthesia in dogs.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.85-87
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• 2014

We studied the characteristics of emissive state of the first (p-G1) and second (p-G2) generation of phenylacetylene dendrimers bearing stilbene as a core by using time-resolved fluorescence spectroscopy in cyclohexane (c-Hex) and N, N-dimethylformide (DMF), which are nonpolar and polar solvents, respectively. Time-dependent red-shift of emission spectra p-G2 both in c-Hex and DMF was observed in comparison with p-G1. Besides, the time constant of red-shift of spectra was found to be larger in DMF than in c-Hex. This indicates that the emissive state of p-G2 has a polar character in DMF as a result of charge delocalization from core to peripheral dendrons followed by stabilization of emissive state.

• Proceedings of the Optical Society of Korea Conference
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• 1990.07a
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• pp.94-100
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• 1990

The rapid quenching dynamics of the F-center excitation by CN- defects in CsCl crystals were investigated by monitoring the ground state bleach recovery kinetics of F-centers, using a picosecond streak camera absorption spectrometer. The F-centers in CN- doped quenched samples show two bleach recovery components. Optical aggregation converts the slow component to the fast component. The slow one is due to the normal relaxation of the F*-centers as found in CN_ free crystals. The fast one is due to the energy transfer of the F-center electronic excitation to the vibrational energy levels of CN_ molecualr defects. The energy transfer occurs only in the F-center-CN_ defect pairs, FH(CN_)-centers.

• Tribology and Lubricants
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• v.12 no.2
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• pp.65-73
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• 1996

Rapid increase of Refrigeration and Air conditioning system in modem industries brings attention to the urgency of core technology development in the area. This paper presents theoretical investigation of the lubrication characteristics of rotary compressor for refrigeration and air conditioning. In order to analyze the lubrication characteristics of the main & sub bearing of rotary compressor, the bearing force and locus of shaft center are analyzed by the dynamic analysis of rotary compressor and numerical analysis of Reynolds equation as the operating condition is changed in various ways. In this paper, we used the Runge-Kutta method for the dynamic analysis of rotary compressor and the SOR (Successive OverRelaxation) method for the numerical analysis of Reynolds equation. The result shows that the operating condition of sub bearing is severer than that of main bearing, and eccentricity ratio grows as the bearing force increases. It is believed that the result can be applied to the design of alternative refrigerant rotary compressor.

• 전기의세계
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• v.25 no.2
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• pp.100-106
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• 1976

A comparative study on thermal, static mechanical and dielectric characteristics were made over a temperature range of ca.20.deg.C to 320.deg.C and a frequency range of KHZ to MHZ band on low density polyethylene specimens crosslinked, respectively, by radiation and chemical method. The thermal property of both specimens shows that softening point appears to unchange by crosslinking, however, melting and liquidizing temperatures attain rapid increase at the imitiation of crosslinking. Mechanical properties show little difference to both specimens crosslinked by different method, further the behaviors were discussed in connection with the relaxation of molecular segments in amorphous phase. Dose dependent dielectric characteristics observed at ambient temperature under several fixed frequencies exhibit extremities at ca. 20 Mrad and the behaviors also were interpreted qualitatively by taking into consideration of dipole concentration change in amorphous phase together with the role of specimen geometry to the depth of oxidative layer. Observing frequency dependent dielectric characteristics, it was also proved that ionic conduction loss is appreciably greater in the specimen prepared by chemical method than that by radiation.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.68-74
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• 1998

The complexation of ethylammonium ion by alkyl p-tert-butylcalix[6]aryl ester derivatives was studied via measurements of proton and carbon spin-lattice relaxation times $(T_1)$ and chemical shift changes in solution state $(CDCl_3)$. The results indicate that the endo-type complexes are formed and that the overall tumbling rates of these complexes are more rapid than those of the corresponding free hosts. The association constants for these complexes in $THF-d_8$ were determined by $^1H$ NMR titration at several different temperatures to estimate the relevant thermodynamic parameters. The logK's for ethylammonium complexes of methyl, ethyl, and propyl esters at 313 K, for example, were found to be 1.56, 3.41, and 3.08, respectively. The complexes formed may be thought of as being kinetically stable in view of their $^1H$ NMR behavior in 2 : 1 host/guest solution.

• International Journal of High-Rise Buildings
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• v.12 no.3
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• pp.195-201
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• 2023

This paper reviews the history of the birth and development of the skyscraper in Japan, mainly from the perspective of the legal system, and presents the following points: 1) After 1919, building height was limited to 31 m or less, which continued after the war and defined the skyline of Japan's major cities; 2) The 31-meter height limit became a problem during rapid economic growth. With the development of tall building construction technology, the height limit was eliminated, and skyscrapers were born in Japan in the 1960s; 3) Later, the number of skyscrapers increased more rapidly in the post-bubble period after the collapse of the bubble economy in the 2000s than in the boom years of the 1980s, when the floor-area ratio was relaxed for economic uplift and urban renewal. The number of skyscrapers increased rapidly against the backdrop of the deregulation of the floor-area ratio.

• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.