灌漑用水路의 水路損失率 算定에 관한 硏究

李基春,具滋雄,金在英,李宰泳,徐元明 전북대학교 농업과학기술연구소 1982 農大論文集 Vol.13 No.-

This study was carried out in order to estimate water losses in irrigation canals, which may be used to evaluate the water requirement for irrigation projects. The conveyance losses were measured by the inflow-outflow method, the seepage were measured by the ponding method, and the operation losses in the course of irrigation were calculated by comparing the two kinds of losses. The results obtained in this experiment were as follows : Conveyance losses per unit area of wetted perimeter per second by the main irrigation canal, the secondary irrigation canal and the tributary irrigation, canal, were 1.399x10-5m3/m3/sec, 5.154x10-5m3/m3/sec, and 2.670×10-5m3/m3/sec respectively in the Goong-sa area. And they were 1.934x10-5m3/m3/sec, 2.149x10-5m3/m3/sec, and 4.558x10-6m3/m3/sec respectively in the Seong-dug area. Seepage losses per unit area of wetted perimeter per second by the secondary irrigation canal and the tributary irrigation canal, were 2.180×10-6m3/m3/sec and 2.168×10-6m3/m3/sec in the Goons-sa area. 1.150x10-6m3/m3/sec and 1.084x10-6m3 /m3/sec in the Seong-dug area respectively. Operation losses per unit area of wetted perimeter per second by the secondary irrigation canal and the tributary irrigation canal, were 4.936×10-5m3/m3/sec and 2.453×10-5m3/m3/sec in the Goong-sa area, 2.034×10-5m3/m3/sec and 4.450×10-5m3/m3 /sec in the Seong-dug area respectively. Conveyance, seepage and operation losses in the Goong-sa area were 6.7%, 94.6%, and 14.0% more than those in the Seong-dug area. Operation losses amount to about 17 times as much as seepage losses in the Goons-sa area and about 29 times in the Seong-dug area .The seepage losses depend much on the soil texture. ranging from 7.437×10-7m3/m3/sec to 2.430x10-6 m3/m3/sec. Water loss rates in the main irrigation canal, the secondary irrigation canal and the tributary irrigation canal, were estimated as 8.49%. 37.27%, and 9.8l%, respectively in the Goong-sa area. And they were estimated as 15.10%, 32.67% and 13.73% respectively in the Seong-dug area.

Synthesis and Thermoelectric Properties of Ce1−z Pr z Fe4−x Co x Sb12 Skutterudites

Song, K. M.,Shin, D. K.,Jang, K. W.,Choi, S. M.,Lee, S.,Seo, W. S.,Kim, I. H. Springer Science + Business Media 2017 Journal of electronic materials Vol.46 No.5

<P>p-Type Ce1-z Pr (z) Fe4-x Co (x) Sb-12 skutterudites were prepared by encapsulated melting, quenching, annealing, and hot pressing. While the skutterudite phase was successfully synthesized, a small amount of the secondary phase (FeSb2) was observed. According to the scanning electron microscope analysis, (Ce,Pr)Sb-2 phases were also observed for Co-substituted specimens (x = 0.5). The electrical conductivity decreased with increasing temperature, implying a degenerate semiconductor behavior, and also decreased with increasing Co contents. All specimens showed p-type characteristics having positive signs of the Hall coefficient and the Seebeck coefficient. The Seebeck coefficient increased with increasing temperature and reached a maximum value at 823 K. The power factor (PF) increased with decreasing Co content and Ce0.75Pr0.25 Fe4Sb12 showed a peak value of PF = 3.2 mW m(-1) K-2 at 823 K. The electronic thermal conductivity decreased with increasing Co contents and the lattice thermal conductivity decreased with decreasing Ce and Co contents at high temperature. The thermal conductivity increased at temperatures above 623 K due to bipolar conduction. The dimensionless figurea of pound merit (ZT) showed a maximum value of ZT = 0.84 at 823 K for Ce0.25Pr0.75Fe4Sb12.</P>

Relationship Between K_trans and K₁ with Simultaneous Versus Separate MR/PET in Rabbits with VX2 Tumors

Lee, K. H.,Kang, S. K.,Goo, J. M.,Lee, J. S.,Cheon, G. J.,Seo, S.,Hwang, E. J. INTERNATIONAL INSTITUTE OF ANTICANCER RESEARCH 2017 Anticancer research Vol.37 No.3

<P>Background/Aim: To compare the relationship between Ktrans from DCE-MRI and K1 from dynamic (NNH3)-N-13- PET, with simultaneous and separate MR/PET in the VX-2 rabbit carcinoma model. Materials and Methods: MR/PET was performed simultaneously and separately, 14 and 15 days after VX-2 tumor implantation at the paravertebral muscle. The Ktrans and K-1 values were estimated using an in-house software program. The relationships between Ktrans and K-1 were analyzed using Pearson's correlation coefficients and linear/non-linear regression function. Results: Assuming a linear relationship, Ktrans and K-1 exhibited a moderate positive correlations with both simultaneous ( r=0.54-0.57) and separate ( r=0.53-0.69) imaging. However, while the Ktrans and K-1 from separate imaging were linearly correlated, those from simultaneous imaging exhibited a non-linear relationship. The amount of change in K-1 associated with a unit increase in Ktrans varied depending on Ktrans values. Conclusion: The relationship between K-trans and K-1 may be mis-interpreted with separate MR and PET acquisition.</P>

Hydrogen production by auto-thermal reforming of ethanol over nickel catalyst supported on metal oxide-stabilized zirconia

Youn, M.H.,Seo, J.G.,Song, I.K. Pergamon Press ; Elsevier Science Ltd 2010 International journal of hydrogen energy Vol.35 No.8

Metal oxide-stabilized mesoporous zirconia supports (M-ZrO<SUB>2</SUB> with different metal oxide stabilizer (M = Zr, Y, La, Ca, and Mg) were prepared by a templating sol-gel method. 20 wt% Ni catalysts supported on M-ZrO<SUB>2</SUB>(M = Zr, Y, La, Ca, and Mg) were then prepared by an incipient wetness impregnation method for use in hydrogen production by auto-thermal reforming of ethanol. The effect of metal oxide stabilizer (M = Zr, Y, La, Ca, and Mg) on the catalytic performance of supported nickel catalysts was investigated. Ni/M-ZrO<SUB>2</SUB>(M = Y, La, Ca, and Mg) catalysts exhibited a higher catalytic performance than Ni/Zr-ZrO<SUB>2</SUB> because surface oxygen vacancy of M-ZrO<SUB>2</SUB>(M = Y, La, Ca, and Mg) and reducibility of Ni/M-ZrO<SUB>2</SUB>(M = Y, La, Ca, and Mg) were enhanced by the addition of lower valent metal cation. Hydrogen yield over Ni/M-ZrO<SUB>2</SUB>(M = Zr, Y, La, Ca, and Mg) catalyst was monotonically increased with increasing both surface oxygen vacancy of M-ZrO<SUB>2</SUB>support and reducibility of Ni/M-ZrO<SUB>2</SUB>catalyst. Among the catalysts tested, Ni catalyst supported on yttria-stabilized mesoporous zirconia (Ni/Y-ZrO<SUB>2</SUB> showed the best catalytic performance.

고온기 초지의 예취관리에 관한 연구 6 . 고온기간중 예취높이와 질소 및 칼리추비가 혼파초지의 식생과 수량 및 목초품질에 미치는 영향

서성(S . Seo),조무환(M . H . Jo),박문수(M . S . Park),이종경(J . K . Lee),한영춘(Y . C . Han) 한국축산학회 1988 한국축산학회지 Vol.30 No.8

A field experiment was carried out to determine the effects of cutting height at the third cut and application of N and K₂O after cutting during mid-summer season on the soil temperature, plant height, grass coverage, percentages of grass and legume, yield and grass quality in orchardgrass dominated pasture. With three cutting heights (3, 6 and 9㎝) and 4 fertilizer levels (0, N 50㎏, K₂O 50㎏, and N 50㎏ + K₂O 50㎏ ㏊^(-1)), present experiment was conducted at Livestock Experiment Station, Suwon in 1987. 1. The soil temperature after the third cut was rapidly elevated, and lower value was observed with 9㎝ of cutting height through the regrowth period. Plant height after cutting was remarkably increased with higher stubble height regardless of fertilizer levels. 2. The grass coverage and percentage of grass were increased as stubble height was high, while the influence of fertilizer on those was very little. Application of N and K₂O with lower stubble height significantly increased the percentage of bareland. 3. The yield at the third cut was decreased with higher height. But the regrowth yield was significantly increased as the cutting height was increased regardless of fertilizer levels. Regrowth yield was great at N 50㎏ + K₂O 50㎏ $gt; 0 $gt; K₂O 50㎏, N 50㎏, in that order. However, there were not significantly different on regrowth yield among fertilizer treatment. 4. The contents of crude protein, crude fat, crude ash, P, K and Ca were decreased as stubble height was high, and that of crude fiber was increased at 9 ㎝ cutting height. Also the influence of N and K₂O fertilizer on grass quality was little.

High-temperature thermoelectric properties of polycrystalline CaMn_1-<i>x</i>Nb_<i>x</i>O_3-δ

Seo, J.W.,Kim, G.H.,Choi, S.-M.,Park, K. Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.8

<P><B>Abstract</B></P> <P>The structural and thermoelectric (TE) properties of polycrystalline CaMn<SUB>1-<I>x</I> </SUB>Nb<SUB> <I>x</I> </SUB>O<SUB>3-δ</SUB> (0.025 ≤ <I>x</I> ≤ 0.25) were studied with X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and electrical transport measurements, with an emphasis placed on the Nb<SUP>5+</SUP> content. The CaMn<SUB>1-<I>x</I> </SUB>Nb<SUB> <I>x</I> </SUB>O<SUB>3-δ</SUB> crystallized in an orthorhombic perovskite structure of the <I>Pnma</I> space group. The density and grain size of the CaMn<SUB>1-<I>x</I> </SUB>Nb<SUB> <I>x</I> </SUB>O<SUB>3-δ</SUB> samples gradually decreased when Nb<SUP>5+</SUP> ions substituted Mn<SUP>4+</SUP> ions. The CaMn<SUB>0.95</SUB>Nb<SUB>0.05</SUB>O<SUB>3-δ</SUB> sample contained charge-ordered domains, stacking faults, and micro-twins. The substitution of Nb<SUP>5+</SUP> for Mn<SUP>4+</SUP> up to <I>x</I> = 0.15 led to an increase in electrical conductivity, mainly due to an increased electron concentration. The CaMn<SUB>1-<I>x</I> </SUB>Nb<SUB> <I>x</I> </SUB>O<SUB>3-δ</SUB> samples with low Nb<SUP>5+</SUP> contents (0.025 ≤<I> x</I> ≤ 0.15) showed metallic behavior, whereas those with high Nb<SUP>5+</SUP> contents (0.2 ≤<I> x</I> ≤ 0.25) showed semiconducting behavior. The Nb<SUP>5+</SUP> substitution lowered the absolute value of the Seebeck coefficient for the CaMn<SUB>1-<I>x</I> </SUB>Nb<SUB> <I>x</I> </SUB>O<SUB>3-δ</SUB> samples due to an increased electron concentration. The largest power factor (1.19 × 10<SUP>−4</SUP> W m<SUP>−1</SUP> K<SUP>−2</SUP>) was obtained for CaMn<SUB>0.95</SUB>Nb<SUB>0.05</SUB>O<SUB>3-δ</SUB> at 800 °C. The partial substitution of Nb<SUP>5+</SUP> for Mn<SUP>4+</SUP> in CaMnO<SUB>3-δ</SUB> proved to be highly effective for improving high-temperature TE properties.</P>

Microstructure and piezoelectric properties of (Na_0.5K_0.5)NbO₃ lead-free piezoelectric ceramics with V₂O₅ addition

Seo, I.-T.,Park, H.-Y.,Dung, N.V.,Choi, M.-K.,Nahm, S.,Lee, H.-G.,Choi, B.-H. IEEE 2009 and Frequency Control Vol.56 No.11

<P>Various amounts of Nb<SUB>2</SUB>O<SUB>5</SUB> in the (Na<SUB>0.5</SUB>K<SUB>0.5</SUB>) NbO<SUB>3</SUB> (NKN) ceramic were replaced by V<SUB>2</SUB>O<SUB>5</SUB> to decrease its sintering temperature to below 950°C. A small V<SUB>2</SUB>O<SUB>5</SUB> content resulted in a dense microstructure with an increased grain size for the specimen sintered at 900°C due to the presence of a liquid phase. When V<SUB>2</SUB>O<SUB>5</SUB> was added to the NKN ceramics, their orthorhombic-to-tetragonal transition temperature increased from 178°C to around 200°C. However, their Curie temperature decreased from 402°C to around 330°C. The k<SUB>p</SUB>, <SUB>ε3</SUB> <SUP>T</SUP>/<SUB>ε0</SUB>, and Q<SUB>m</SUB> values increased with V<SUB>2</SUB>O<SUB>5</SUB> addition, probably due to the increased density and poling state, which was identified by the phase angle. The specimen with x = 0.05, sintered at 900°C for 8 h, exhibited the following piezoelectric properties: k<SUB>p</SUB> = 0.32, <SUB>ε3</SUB> <SUP>T</SUP>/<SUB>ε0</SUB> = 245, d<SUB>33</SUB> = 120 (pC/N), and Q<SUB>m</SUB> = 232.</P>

Triplet state and phosphorescence of hole-transport layer and its triplet exciton confinement

Seo, J.H.,Han, N.S.,Shim, H.S.,Park, S.M.,Kwon, J.H.,Song, J.K. North Holland ; Elsevier Science Ltd 2010 Chemical physics letters Vol.499 No.4

The triplet state of 4,4',4''-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA) and the dynamics of the singlet and the triplet states were examined to understand the confinement effect of m-MTDATA as host materials for phosphorescent organic light-emitting diodes. The time-resolved photoluminescence spectra revealed phosphorescence at approximately 480nm (2.58eV). The time constant of the T<SUB>1</SUB> state was 1.2μs. The dynamics of delayed fluorescence was closely related to that of phosphorescence. The triplet energy of a green phosphorescent sensitizer was well-confined in the m-MTDATA host, which suggests the application of m-MTDATA as possible host materials.

The inhibitory effects of quercetin on obesity and obesity-induced inflammation by regulation of MAPK signaling

Seo, M.J.,Lee, Y.J.,Hwang, J.H.,Kim, K.J.,Lee, B.Y. Butterworths ; Elsevier Science Ltd 2015 The Journal of nutritional biochemistry Vol.26 No.11

Quercetin is a flavonoid found in fruits, vegetables, leaves and grains. It has inhibitory, antiviral, antiasthma, anticancer and antiinflammatory effects. Research has suggested that obesity is linked to metabolic disorders. In this study, we examined the inhibitory effect of quercetin on lipid accumulation and obesity-induced inflammation using 3T3-L1, RAW264.7, zebrafish and mouse models. Quercetin suppressed protein levels of the key adipogenic factors C/EBPβ, C/EBPα, PPARγ and FABP4 and the TG-synthesis enzymes lipin1, DGAT1 and LPAATθ. Activation of m-TOR and p70S6K, which are related to insulin and adipogenesis, was down-regulated during adipogenesis in 3T3-L1 cells. Recent research suggested that MAPK signaling factors were involved in adipogenesis and inflammation and that the adipokines MCP-1 and TNF-α attracted macrophages into adipose tissue. Our data showed that quercetin inhibited the MAPK signaling factors ERK½, JNK and p38MAPK and MCP-1 and TNF-α in adipocytes and macrophages. Quercetin also inhibited secretion of the inflammatory cytokines IL-1β and IL-6 and stimulated that of IL-10, an antiinflammatory cytokine. In this study, we confirmed the inhibitory effects of quercetin in adipogenesis and inflammation using a mouse model. In mice, quercetin reduced body weight (almost 40%) and suppressed expression of adipogenic, lipogenic and inflammation-related cytokines. Our data demonstrated that quercetin inhibits lipid accumulation and obesity-induced inflammation in the cell and animal models. Our study suggested that quercetin may represent a potential therapeutic agent for other metabolic disorders by regulating obesity and obesity-induced inflammation.

Highly Porous Silica Nanoaerogels for Ultrafast Nonlinear Optical Applications

Seo, Jae Tae,Ma, S.M.,Lee, K.,Brown, H.,Jackson, A.,Skyles, T.,Cubbage, N.M.,Tabibi, B.,Yoo, K.P.,Kim, Suk Young,Jung, S.S.,Namkung, M. Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.287 No.-

<P>Highly porous silica nanoaerogels with low apparent density of ~0.1 g/cm3 and ~0.07 g/cm3 were synthesized through two-step sol-gel processing and low temperature supercritical fluid drying. The nonlinear refraction (γ) of silica nanoaerogels was estimated to be ~ -3.4 x 10-16 m2/W for ~0.1 g/cm3 and ~0.07 g/cm3 apparent densities with a signal-beam femtosecond z-scan spectroscopy. The third-order nonlinear refraction coefficient of nanostructure silica nanoaerogels was almost four orders larger than that of bulk silica materials. The large nonlinearrefraction with high nonlinear figure of merit (γ/βλ, β~2×10-10 m/W for 0.07 g/cm3 apparent density, β~6×10-10 m/W for 0.1 g/cm3 apparent density, λ~0.775 µm) is an ideal optical property for nonlinear applications of homeland security, battlefield enhancement, and industrial uses.</P>