Effects of Y₂O₃ additions on the oxygen diffusion in top-seeded melt growth processed YBa₂Cu₃O_7-y superconductors

Jun, B.H.,Jung, S.A.,Park, S.D.,Park, B.J.,Han, Y.H.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

To understand the effect of Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211)/YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> (Y123) interfaces on the oxygen diffusion in single grain YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> superconductors, single grain Y123 superconductors with 0.05 and 0.3moles of Y<SUB>2</SUB>O<SUB>3</SUB> additions were fabricated by a top-seeded melt growth (TSMG) process. Y123 compacts with Y<SUB>2</SUB>O<SUB>3</SUB> additions were subjected to melt growth heating cycles with a cooling rate of 1<SUP>o</SUP>C/h through a peritectic temperature (1015<SUP>o</SUP>C) and then annealed at 450<SUP>o</SUP>C for 200h in flowing oxygen. The superconducting temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) were estimated for the three different regions (top surface (s), intermediate (i) and center (c)) of samples. The amount of Y211/Y123 interface area in single grain Y123 superconductors was successfully controlled by Y<SUB>2</SUB>O<SUB>3</SUB> additions. The T<SUB>c</SUB> values of s regions were higher than those of i and c regions, which indicates the presence of more oxygen at the sample surfaces. In addition, the T<SUB>c</SUB> values of i and c regions of the Y123 sample with 0.3mole Y<SUB>2</SUB>O<SUB>3</SUB> addition were higher than those of the same regions of the Y123 sample with 0.05mole Y<SUB>2</SUB>O<SUB>3</SUB> addition due to the promoted oxygen diffusion through Y211/Y123 interfaces and other related defects. In spite of the promoted oxygen diffusion by Y<SUB>2</SUB>O<SUB>3</SUB> addition, the large T<SUB>c</SUB> difference among the regions still existed, which suggests sluggish oxygen diffusion into single Y123 grains.

Effects of calcium doping on the superconducting properties of top-seeded melt growth processed Y_1.5Ba_2-xCa_xCu₃O_y superconductors

Park, S.D.,Kim, H.J.,Park, B.J.,Han, Y.H.,Jun, B.H.,Lee, J.S.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

The effect of calcium doping on the superconducting properties of top seeded melt growth (TSMG) processed Y<SUB>1.5</SUB>Ba<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>y</SUB> superconductors was studied in terms of calcium content (X<SUB>ca</SUB>). YBa<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>7-δ</SUB> (X<SUB>ca</SUB>=0, 0.005, 0.01, 0.02, 0.04, 0.1, 0.3) powders were synthesized by the powder calcination method. YBa<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>7-δ</SUB> powders were mixed with 0.25mole Y<SUB>2</SUB>O<SUB>3</SUB> powder and 1wt.% CeO<SUB>2</SUB> as Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) refiner, and finally made into Y<SUB>1</SUB>.<SUB>5</SUB>Ba<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>y</SUB> (Y1.5)+1wt.% CeO<SUB>2</SUB> composition. The single Y123 growth on the top surface was observed up to X<SUB>ca</SUB>=0.1, while the multiple Y123 growth was observed at X<SUB>ca</SUB>≥0.1. The superconducting transition temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) of TSMG processed Y1.5 samples were inversely proportional to X<SUB>ca</SUB>. The Y211 size increased with increasing X<SUB>ca</SUB> due to the enhancement of Y211 coarsening by calcium doping. No Y211 refining effect by CeO<SUB>2</SUB> was observed in the calcium doped samples. The T<SUB>c</SUB> and J<SUB>c</SUB> decrease by calcium doping are likely to be due to the calcium incorporation with the Y123 lattice and formation of coarse Y211 particles.

TmSR-C, scavenger receptor class C, plays a pivotal role in antifungal and antibacterial immunity in the coleopteran insect Tenebrio molitor

Kim, S.G.,Jo, Y.H.,Seong, J.H.,Park, K.B.,Noh, M.Y.,Cho, J.H.,Ko, H.J.,Kim, C.E.,Tindwa, H.,Patnaik, B.B.,Bang, I.S.,Lee, Y.S.,Han, Y.S. Pergamon Press ; Elsevier Science Ltd 2017 Insect biochemistry and molecular biology Vol.89 No.-

Scavenger receptors (SRs) constitute a family of membrane-bound receptors that bind to multiple ligands. The SR family of proteins is involved in removing cellular debris, oxidized low-density lipoproteins, and pathogens. Specifically, class C scavenger receptors (SR-C) have also been reported to be involved in phagocytosis of gram-positive and -negative bacteria in Drosophila and viruses in shrimp. However, reports are unavailable regarding the role of SR-C in antifungal immune mechanisms in insects. In this study, a full-length Tenebrio molitor SR-C (TmSR-C) sequence was obtained by 5'- and 3'-Rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The TmSR-C full-length cDNA comprised 1671 bp with 5'- and 3'-untranslated regions of 23- and 107-bp, respectively. TmSR-C encodes a putative protein of 556 amino acid residues that is constitutively expressed in all tissues of late instar larvae and 2-day-old adults, with the highest transcript levels observed in hemocytes of larvae and adults. TmSR-C mRNA showed a 2.5-fold and 3-fold increase at 24 and 6 h after infection with Candida albicans and β-glucan, respectively. Immunoassay with TmSR-C polyclonal antibody showed induction of the putative protein in the cytosols of hemocytes at 3 h after inoculation of C. albicans. RNA interference (RNAi)-based gene silencing and phagocytosis assays were used to understand the role of TmSR-C in antifungal immunity. Silencing of TmSR-C transcripts reduced the survivability of late instar larvae at 2 days post-inoculation of C. albicans, Escherichia coli, or Staphylococcus aureus. Furthermore, in TmSR-C-silenced larvae, there was a decline in the rate of microorganism phagocytosis. Taken together, results of this study suggest that TmSR-C plays a pivotal role in phagocytosing not only fungi but also gram-negative and -positive bacteria in T. molitor.

Ion scattering spectroscopy study of the Si(001)c(4x4)-C surface reconstruction

Park J. Y.,Chae K. H.,Choi D. S.,Kim J. Y.,Kim S. S.,Seo J. H.,Whang C. N. 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.3

Reconstructed Si(001)c(4 4)-C surface has been studied by coaxial impact collision ion scattering spectroscopy (CAICISS). When 100L ethylene (C2H4) was exposed on Si(001)-(2 1) surface at 700 C, Si(001) dimer structures were changed by induced carbon (C) atoms. The experimental CAICISS spectra and simulation results reveal that the reconstructed Si(001)c(4 4)-C surface shows good agreement with the missing dimer model, rather than the Si-C heterodimer model, and adsorbed C atoms in uence only the reconstructed vertical plane of Si(001) surface. On comparing the azimuthal-scan curves for 100L C/Si(001) with those for clean Si(001), it can be suggested that C atoms occupy the fourth subsurface layer of Si(001) directly below the HB (bridge) site. These results are new evidence supporting the previous studies based on the C incorporation into Si(001) surface with missing dimers and the substitution of the fourth Si layers.

Ex-situ catalytic pyrolysis of citrus fruit peels over mesoporous MFI and Al-MCM-41

Kim, Y.M.,Jae, J.,Lee, H.W.,Han, T.U.,Lee, H.,Park, S.H.,Kim, S.,Watanabe, C.,Park, Y.K. Pergamon ; Elsevier Science Ltd 2016 Energy conversion and management Vol.125 No.-

The thermal and ex-situ catalytic pyrolysis of different citrus peels, Citrus paradisi peel, Citrus sinensis peel, Citrus unshiu peel, and Citrus limon peel, were studied by thermogravimetric, evolved gas analysis-mass spectrometry and tandem micro-reactor-gas chromatograph/mass spectrometry analyses. Kinetic analysis revealed more complicated reaction steps and a wider range of activation energies of citrus peels than those of wood powder due to the presence of pectin in the citrus peels. Large amounts of methanol formation from each citrus peel were also recorded by evolved gas analysis-mass spectrometry and fast pyrolysis-gas chromatograph/mass spectrometry analyses at the main decomposition temperature of pectin, between 150 and 250<SUP>o</SUP>C. Mesoporous MFI was found to be a more effective catalyst for the production of mono aromatic compounds (benzene, toluene, ethylbenzene, and xylene; 3.06-4.17C%) and light olefins (ethene, propene, butene, and butadiene; 8.13-9.13C%) than Al-MCM-41 (mono aromatic compounds 0.67-0.93C% and light olefins 3.61-4.58C%) because of its higher catalytic activity in deoxygenation and aromatization due to the stronger acidity of mesoporous MFI. The yield of mono aromatic compounds over mesoporous MFI was highest from C. paradisi peel (4.17C%), followed in order by C. sinensis peel (3.83C%), C. unshiu peel (3.61C%), and C. limon peel (3.06C%), due mainly to the different contents and properties of pectin in each citrus peel. The higher activities of mesoporous MFI than Al-MCM-41 were also maintained during the 7 times sequential catalytic pyrolysis of C. paradisi peel, demonstrating the stability of mesoporous MFI catalyst.

Effects of $BaCO_3$ purity on the superconducting properties of top seeded melt growth processed $Y_{1+x}Ba_2Cu_3O_y$ superconductors

Choi, J.S.,Park, S.D.,Jun, B.H.,Han, Y.H.,Sung, T.H.,Choo, K.N.,Kim, C.J. The Korean Society of Superconductivity and Cryoge 2009 한국초전도저온공학회논문지 Vol.11 No.2

Effects of $BaCO_3$ purity on the superconducting properties of top seeded melt growth (TSMG) processed $Y_{1+x}Ba_2Cu_3O_{7-y}$ (Y1+x, x=0.1 and 0.2) superconductors were investigated. $YBa_2Cu_3O_{7-y}$ (Y123) powder prepared using $BaCO_3$ with 99.75% purity and commercially available Y123 powder of 99.9% were used for the fabrication of single Y123 grain superconductors. $T_c$ values of the Y1+x samples prepared using low purity Y123 powder were slightly lower than those of the samples prepared using a high purity powder. In addition to the lower $T_c$, an anomalous peak effect in the intermediate magnetic fields was observed in Y1+x samples prepared using the low purity $BaCO_3$ powder. The slight decrease in $T_c$ and the anomalous peak effect are ascribed to the possible incorporation of a Y123 phase with impurity elements such as strontium and calcium included in the $BaCO_3$powder of 99.7%. The result suggests that the low purity $BaCO_3$ powder of a low price can be used as a raw power for the fabrication of single grain YBCO bulk superconductors.

육성돈에 미생물제제 급여시 분뇨 특성에 미치는 효과 연구

곽정훈,최동윤,박치호,김재환,정광화,양창범,유용희,라창식,Kwag, J.H.,Choi, D.Y.,Park, Ch.H.,Kim, J.H.,Jeong, K.H.,Yang, Ch.B.,Yoo, Y.H.,La, C.S. 한국축산환경학회 2007 축산시설환경학회지 Vol.13 No.1

본 시험은 육성돈 사료에 미생물제제를 사료에 미생물제제 A 및 B 0.1 미생물제제 C를 0.2% 혼합 급여할 경우 사료섭취량 및 돈분의 오염물질 배설농도에 미치는 영향을 분석하기 위하여 4처리$\times$반복당 5두로서 총 20두를 공시하여 실시하였는데 그 결과를 요약하면 다음과 같다. 1. 육성비육돈의 일일 평균사료섭취량은 대조구 2.06kg/일.두였고 미생물 A, B, C 구는 각각 2.13kg/일.두, 2.17, 2.34로 미생물제제 C구에서 일일 사료섭취량이 가장 높게 조사되었으며(p<0.05), 2. 일일평균 음수량은 사료섭취량이 높았던 미생물 C구에서 2.89kg/일/두로 가장 높게 조사되었다(p<0.05). 3. 미생물제제 처리구별로 분뇨 배설량은 사료섭취량이 높았던 미생물제제 C 구에서 가장 많이 배설되는 것으로 조사되었으며 (0<0.05), 돈뇨의 배설량도 미생물제제 C구에서 2.31kg/일/두에서 높았다(p<0.05). 4. 육성돈의 성장단계별 돈분뇨의 수분 함량은 및 비료성분인 T-N, $P_2O_5,\;K_2O$ 성분도 처리간에 큰 차이를 보이지 않았다(p<0.05). 5. 육성돈 분뇨의 평균 BOD 농도는 돈분의 경우 미생물제제 A, B제제 급여구가 유의적으로 높게 조사되었다(p<0.05). 그리고 돈뇨의 BOD의 경우에도 미생물제제 A급 여구에서 $6,537mg/\ell$로 가장 높은 것으로 조사되었다(p<0.05). 6. COD의 경우에도 미생물 C급여구에서 가장 높게 조사되었으며(p<0.05). 돈뇨의 경우에는 미생물제제 A급여구에서 평균 $8,566mg\ell$로 가장 높았다(p<0.05). 7. SS 농도는 대조구에서 가장 높게 조사 되었으며(p<0.05), 그 다음이 미생물 B> 미생물 C> 대조구 순으로 조사되었다. 8. 돈분뇨중의 T-N 농도는 처리구간에 유의적인 차이가 나타나지 않았다(p<0.05). 9. 돈분중의 T-P 농도는 미생물제제 처리 구간별로 미생물제제 A, C 급여구에서 유의적인 차이가 나는 것으로 조사되었다(p<0.05). 이상의 결과를 요약해보면 육성돈에 미생물제제 혼합급여는 사료섭취량을 증가시키는데 효과가 있으나 비료성분 배설량에는 큰 차이를 보이지 않는 것으로 조사되었으며, 오염물질 배설량의 경우에는 사료섭취량이 높은 미생물제제 C 급여구에서 높은 것으로 조사되었다. The effects of microbial feedstuff additives on feed conversion rate and physical and chemical characteristics of excreta in growing pigs were investigated. Three different products (A, B and C) were compared. Microbial population tests showed B contained higher numbers of total bacteria, Lactobacillus spp. and yeasts. The amylase activity of B was also higher than that of A and C. The daily feed intake rates fer control, A, B and C were 2.06, 2.13, 2.17 and 2.34 kg, respectively. Pigs feed product C had the highest liveweight gain(2.89 kg). However, the results of feed conversion rate were not significantly different between treatments. Amount of faces excreted for control, A, B and C was 1.18, 1,19, 1.23 and 1.32 kg, respectively. Urine volume for control, A, B, and C was 1.91, 1.80, 2.19 and 2.31 kg respectively. Moisture content, T-N, $P_2O_5$ and $K_2O$ in pig manure were not significantly different between treatments. The range of BOD values was 63,453 to $73,758mg/\ell$ for faeces, and 5,678 to $7,428mg/\ell$, for urine. SS values of solid and liquid excreta ranged from 142,200 to 176,000 and from 710 to $1,025mg/\ell$, respectively.

Characterization of Phosphoinositide-3-kinase, Class 3 (PIK3C3) Gene and Association Tests with Quantitative Traits in Pigs

Kim, J.H.,Choi, B.H.,Lim, H.T.,Park, E.W.,Lee, S.H.,Seo, B.Y.,Cho, I.C.,Lee, J.G.,Oh, S.J.,Jeon, J.T. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.12

This study deals with the characterization of porcine PIK3C3 and association tests with quantitative traits. PIK3C3 belongs to the class 3 PI3Ks that participate in the regulation of hepatic glucose output, glycogen synthase, and antilipolysis in typical insulin target cells such as those in the such as liver, muscle system, and fat. On the analysis of full-length mRNA sequence, the length of the PIK3C3 CDS was recorded as 2,664 bps. As well, nucleotide and amino acid identities between human and pig subjects were 92% and 99%, respectively. Five SNPs were detected over 5 exons. We performed genotyping by using a SNP C2604T on exon24 for 145 F$_2$ animals (from a cross between Korean native boars and Landrace sows) by PCR-RFLP analysis with Hpy8I used to investigate the relationship between growth and fat depot traits. In the total association analysis, which doesn' consider transmission disequilibrium, the SNP showed a significant effect (p<0.05) on body weight and carcass fat at 30 weeks of age as well as a highly significant effect (p<0.01) on back fat. In an additional sib-pair analysis, C allele still showed positive and significant effects (p<0.05) on back fat thickness and carcass fat. Moreover, the effects of C allele on the means of within-family components for carcass fat and back fat were estimated as 2.76 kg and 5.07 mm, respectively. As a result, the SNP of porcine PIK3C3 discovered in this study could be utilized as a possible genetic marker for the selection of pigs that possess low levels of back fat and carcass fat at the slaughter weight.

발화합성용액의 pH 가 Y1Ba2Cu3O7-x 초전도상 생성 속도에 미치는 영향

박정식,김영순,양석우,김춘영,신형식 ( J . S . Park,Y . S . Kim,S . W . Yang,C . Y . Kim,H . S,Shin ) 한국공업화학회 1998 공업화학 Vol.9 No.2

Y₂O₃(99.9%)와 BaCO₃(99.9%) 및 CuO(99.9%)를 사용하여 Y₁Ba₂Cu₃O_(7-x)(123) 분말을 발화합성법에 의해 제조하였다. 발화전 용액을 여러 가지 pH로 변화시켜 제조하였으며, 이 분말을 성형하여 열처리 온도와 시간 변화에 따른 상형성과 반응특성을 조사하였다. 시료의 조성과 조직의 특성은 ICP와 SEM을 이용하여 측정하였고, Y-Ba-Cu-O계의 상형성과 전화율을 결정하기 위해 X선 회절분석을 하였다. 발화합성법을 이용하여 pH 7(±0.3)에서 제조된 123 분말이 순도와 균일성 및 반응특성에서 가장 좋은 결과를 보였다. pH 7(±0.3)에서 제조된 분말을 이용한 123 상생성에 따른 활성화에너지(ΔE_n)는 191 kJ/mol으로서 고상반응법의 230 kJ/mol에 약 13% 정도 더 낮았다. The Y₁Ba₂Cu₃O_(7-x)(123) superconductor powders were prepared by pyrophoric synthesis method(PSM) using Y₂O₃(99.9%), BaCO₃(99.9%), and CuO(99.9%) powders. The phase formation and reaction kinetics of 123 superconductor manufactured with powders prepared in various pHs of pyrophoric synthetic solution have been studied through the experiments at various heat treatment temperatures and times. Inductively coupled plasma(ICP) spectroscopy and scanning electron microscopy(SEM) measurements were performed to examine the composition and morphology of the sample. X-ray diffraction(XRD) analysis was done to determine phase formation and conversion ratio of Y-Ba-Cu-O systems. The 123 powder prepared at pH 7(±0.3) yields the best result in terms of purity, homogeneity, and reactivity. The activation energies(ΔE_n) of 123 phase formation were found to be 191 kJ/mol and 230 kJ/mol in solid state reaction method and pyrophoric synthesis method, respectively.

Reduced water vapor transmission rates of low-temperature-processed and sol-gel-derived titanium oxide thin films on flexible substrates

Park, S.,Kim, L.H.,Jeong, Y.J.,Kim, K.,Park, M.,Baek, Y.,An, T.K.,Nam, S.,Jang, J.,Park, C.E. Elsevier Science 2016 Organic electronics Vol.36 No.-

<P>Sol-gel-derived, crack-free, and condensed TiOx thin films with improved barrier properties were successfully fabricated on polymeric substrates with a simple two-step heat treatment at low temperatures. To assess the barrier properties of the TiOx thin films, Ca corrosion tests were conducted and their water vapor transmission rates (WVTRs) were measured. We found that the two-step heat treatment (at 45 degrees C for 90 min and 110 degrees C for 60 min) produces a close-packed TiOx structure that substantially reduces the WVTRs of the coated polymeric substrates. The WVTRs of 86 nm thick TiOx thin films on polyethylene naphthalate (PEN) substrates at a relative humidity (RH) of 90% were found to be 0.133 g m(-2) day(-1) at 38 degrees C and 0.0387 g m(-2) day(-1) at 25 degrees C. In addition, the WVTR value of the TiOx thin films on PEN substrates are stable with respect to bending: it was found to increase by only similar to 13% after 100 repetitions of bending with a 20 mm radius. (C) 2016 Elsevier B.V. All rights reserved.</P>