Application of a wet oxidation method for the quantification of ³H and ¹⁴C in low-level radwastes

Ahn, H.J.,Song, B.C.,Sohn, S.C.,Lee, M.H.,Song, K.,Jee, K.Y. Pergamon Press ; Elsevier Science Ltd 2013 Applied radiation and isotopes Vol.81 No.-

Wet oxidation methods are utilized to separate and quantify <SUP>3</SUP>H and <SUP>14</SUP>C radionuclides in inorganic and organic radwastes generated at nuclear facilities. Because <SUP>3</SUP>H and <SUP>14</SUP>C are pure beta emitters with half-lives of 12.3 and 5,730 years, respectively, these radionuclides should be chemically separated from other radionuclides present in radwastes for accurate quantification. In particular, a collection technique for <SUP>14</SUP>C radionuclide in radwastes is needed because it is converted into <SUP>14</SUP>CO<SUB>2</SUB> gas by an oxidation reaction. To confirm the recoveries of <SUP>3</SUP>H and <SUP>14</SUP>C, various standard radioactive sources were used to verify the proposed method. Because the majority of <SUP>3</SUP>H radionuclides are distributed in tritiated water (HTO), only tritiated water was used as a standard for <SUP>3</SUP>H radionuclides. Additionally, <SUP>14</SUP>C-labeled methanol (<SUP>14</SUP>CH<SUB>3</SUB>OH), lauric acid (<SUP>14</SUP>CH<SUB>3</SUB>(CH<SUB>2</SUB>)<SUB>10</SUB>COOH), sodium bicarbonate (NaH<SUP>14</SUP>CO<SUB>3</SUB>), and toluene (C<SUB>6</SUB>H<SUB>5</SUB><SUP>14</SUP>CH<SUB>3</SUB>) were used as <SUP>14</SUP>C standards. The compounds were oxidized with chemical oxidants and then separated. The individual species were mixed with a scintillation cocktail and counted using a liquid scintillation counter. The recoveries of <SUP>14</SUP>C and <SUP>3</SUP>H were 82-97% and 98%, respectively. The wet oxidation method will be applied to RI wastes for clearance.

Accelerated cosmological expansion without tension in the Hubble parameter : Fast evolution of the Hubble parameter <i>H(z)</i>

van Putten, Maurice H.P.M.,Gwak, B.,Kang, G.,Kim, C.,Kim, H.-C.,Lee, C.-H.,Lee, J.,Lee, S.,Lee, W. EDP Sciences 2018 The European Physical Journal Conferences Vol.168 No.-

<P>The <I>H</I>0-tension problem poses a confrontation of dark energy driving latetime cosmological expansion measured by the Hubble parameter<I> H</I>(<I>z</I>) over an extended range of redshifts <I>z</I>. Distinct values <I>H</I>0 ≃ 73 km s<SUP>-1</SUP> Mpcs<SUP>-1</SUP> and <I>H</I>0 ≃ 68 km s<SUP>-1</SUP> Mpcs<SUP>-1</SUP> obtain from surveys of the Local Universe and, respectively, ΛCBM analysis of the CMB. These are representative of accelerated expansion with <I>H</I>′(0) ≃ 0 by [see formula in PDF] and, respectively, <I>H</I>′(0) > 0 in ΛCDM, where [see formula in PDF] is a fundamental frequency of the cosmological horizon in a Friedmann-Robertson-Walker universe with deceleration parameter <I>q</I>(<I>z</I>) = -1 + (1+z)<I>H</I><SUP>-1</SUP><I>H</I>′(z). Explicit solution <I>H</I>(z) = <I>H</I>0 [see formula in PDF] and, respectively, <I>H</I>(z) = <I>H</I>0[see formula in PDF] are here compared with recent data on <I>H</I>(<I>z</I>) over 0 ≲ z ≲ 2.The first is found to be free of tension with H0 from local surveys, while the latter is disfavored at 2:7σ A further confrontation obtains in galaxy dynamics by a finite sensitivity of inertia to background cosmology in weak gravity, putting an upper bound of <I>m</I> ≲ 10<SUP>-30</SUP> eV on the mass of dark matter. A <I>C</I><SUP>0</SUP> onset to weak gravity at the de Sitter scale of acceleration <I>adS</I> = <I>cH</I>(<I>z</I>), where <I>c</I> denotes the velocity of light, can be seen in galaxy rotation curves covering 0 ≲ <I>z</I> ≲ 2 Weak gravity in galaxy dynamics hereby provides a proxy for cosmological evolution.</P>

N₂/ CH₄가스비에 따른 Hydrogenated Amorphous Carbon Nitride 박막의 특성

장홍규(H. K. Jang),김근식(G. S. Kim),황보상우(S. W. Whangbo),이연승(Y. S. Lee),황정남(C. N. Whang),유영조(Y. Z. Yoo),김효근(H. G. Kim) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.3

DC saddle-field-plasma-enhanced chemical-vapor deposition(PECVD) 장치를 이용하여 상온에서 p-type Si (100) 기판위에 hydrogenated amorphous carbon nitride [a-C:H(N)]박막을 증착하였다. 원료가스인 CH₄과 N₂의 전체압력은 90 mTorr로 고정하고 N₂/CH₄비를 0에서 4까지 변화하면서 제작한 a-C:H(N) 박막의 미세 구조의 변화를 연구하였다. 진공조의 도달 진공도는 1×10^(-6) Torr이고, 본 실험시 CH₄+N₂가스의 유량은 5 sc㎝으로 고정하고 배기량을 조절하여 진공조의 가스 압력을 90 mTorr로 고정하였으며 기판에 200 V의 직류 bias 전압을 인가하였다. α-step과 X-ray photoelectron spectroscopy(XPS)를 이용한 분석결과 N₂/CH₄비가 0에서 0.5로 증가함에 따라 박막 두께는 4840 Å에서 2600 Å으로 급격히 감소하였으며, 박막내의 탄소에 대한 질소함유량(N/C비)는 N₂/CH₄비가 4일때 최대 0.25로 증가하는 것을 확인하였다. 또한 XPS 스펙트럼의 fitting 결과 N₂/CH₄비가 증가할수록 CN결합이 증가하였다. Fourier Transformation Infrared (FT-IR) 분석결과 N₂/CH₄비가 증가함에 따라 박막내의 C-H 결합은 감소하고, N-H, C≡N 결합은 증가하였다. Optical bandgap 측정 결 과 N₂/CH₄비가 0에서 4로 증가함에 따라 a-C:H(N)박막의 bandgap 에너지는 2.53 eV에서 2.3 eV로 감소하는 것을 확인하였다. Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with substrate bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of N₂to CH₄(N₂/CH₄), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at N₂/CH₄> 0.5, the thickness of the film gradually decreased with the increase of the N₂/CH₄. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of N₂/CH₄. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of N₂/CH₄. Optical band gap energy of the film decreased from 2.53 eV deposited with pure methane to 2.3 eV at the ratio of N₂/CH₄=4.

Intramolecular energy flow and bond dissociation in iodoacetylene and iododiacetylene

Ree,J.,Shin,H. K,Lee,C. S.,Kim,Y.H. 國立昌原大學校 基礎科學硏究所 1994 基礎科學硏究所論文集 Vol.6 No.-

Intermolecular and intramolecular energy flow and subsequent bond dissociation in collinear collisions Ⅰ-C≡C-H+Ar and Ⅰ-C≡C-C≡C-H+Ar have been studied by classical trajectory techniques over the collision energy range of 0 to 10 eV. When the molecule is initially in the ground state, the overall energy transfer in Ⅰ-C≡C-H+Ar is very small, but in Ⅰ-C≡C-C≡C-H+Ar it is large. The collisionally perturbed C-H bond stores a large amount of energy from translation for a brief period during the early stage of collision and transfers most of it to the inner region of the molecule, specifically to the low frequency C-I vibration. Thus the high-frequency vibration of the perturbed C-H bond during the collision plays a crucial role in determining the extent of intramolecular energy transfer and, in turn, C-I dissociation. But in nondissociative collisions, there is another series of the C-H vibration at the latter stage of collision. transferring energy back to translation. This study also considers collision-induced intramolecular energy flow in the molecule with an initially excited C-H bond. The relaxation of the low-lying C-H excitation is significantly weakened, thus becoming comparable to that of the triple bond, in which case the isolating effect of the adjacent C≡C bond is no longer important and intramolecular energy flow becomes efficient.

Effect of Anodic Gas Compositions on the Overpotential in a Molten Carbonate Fuel Cell

Lee C.G.,Kim D.H.,Hong S.W.,Park S.H.,Lim H.C. The Korean Electrochemical Society 2006 한국전기화학회지 Vol.9 No.2

Anodic overpotential has been investigated with gas composition changes in a $100cm^2$ class molten carbonate fuel cell. The overpotential was measured with steady state polarization, reactant gas addition (RA), inert gas step addition (ISA), and electrochemical impedance spectroscopy (EIS) methods at different anodic inlet gas compositions, i.e., $H_2:CO_2:H_2O=0.69:0.17:0.14\;atm\;and\;H_2:CO_2:H_2O=0.33:0.33:0.33\;atm$, at a fixed $H_2$ flow rate. The results demonstrate that the anodic overpotential decreases with increasing $CO_2\;and\;H_2O$ flow rates, indicating the anode reaction is a gas-phase mass-transfer control process of the reactant species, $H_2,\;CO_2,\;and\;H_2O$. It was also found that the mass-transfer resistance due to the $H_2$ species slightly increases at higher $CO_2\;and\;H_2O$ flow rates. EIS showed reduction of the lower frequency semi-circle with increasing $H_2O\;and\;CO_2$ flow rate without affecting the high frequency semi-circle.

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.

돼지 H-FABP 유전자의 다형성 및 경제 형질과의 연관성 구명

최봉환,김태헌,이지웅,조용민,이혜영,조병욱,정일정 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.5

The purpose of this study was to detect association between genetic variation and economic trait in the porcine heart type fatty acid-binding protein gene as a candidate gene for the traits related with growth and meat quality in pigs. The H-FABP is a 15-kDa protein expressed in several tissues with high demand for fat metabolism such as cardiac and skeletal muscle and lactating mammary gland. H-FABP is small intracellular protein involved in fatty acid transport from the plasma membrane to the site of β-oxidation and/or triacylglycerol or phospholipid synthesis. In this study, H-FABP PCR-RFLP was performed in F_(2) population composed of 214 individuals form an intercross between Korean Native Boars and Landrace sows. PCR products form tow primer sets within H-FABP gene were amplified in 850bp and 700bp. Digestion of PCR products with the restriction digestion enzymes HaeⅢ and Hinf Ⅰ, revealed fragment length polymorphisms(RFL. Ps). The genotype frequencies from H-FABP/HaeⅢ was .29 for genotype DD, .53 for genotype Dd, and .15 for genotype dd, respectively. The genotype frequencies of HH, Hh, and hh from H-FABP(hinf Ⅰ was .38, .41, and .20, respectively, in the population.Relationships between their genotypes and economic traits were estimated. In H-FABP/HaeⅢ locus, there were specific genotypes(Dd and dd) associated with economic traits such as body weight. In H-FABP/Hinf Ⅰ Iocus, Genotypes of HH and Hh associated with growth traits such as body weights at 5, 12, and 30 week of age (p<.05 or p<.001) and back fat thickness, body fat including abdominal and trimmed fat (p<.001) and intramuscular fat(p<.05). The 'H'allele was positivecly associated with gaining of body weight and fatness deposition. In conclusion, a significant association of the H-FABP gene from its genetic variation was found on body weight, intramuscular fat and backfat thickness.

On the zeolitic imidazolate framework-8 (ZIF-8) membrane for hydrogen separation from simulated biomass-derived syngas

Yin, H.,Lee, T.,Choi, J.,Yip, A.C.K. Elsevier 2016 Microporous and mesoporous materials Vol.233 No.-

<P>Hydrogen separation from biomass-derived syngas is a critical step in the utilization of gasification technology. Compared with the traditional methods, membrane technology provides an effective and low-cost solution for adjusting the gas composition and collecting H-2 in syngas environments. In this study, a zeolitic imidazolate framework-8 (ZIF-8)-based membrane, which is a potential candidate for H-2 separation from biomass-derived syngas, was successfully fabricated through the seeded (secondary) growth method and the subsequent post-treatments. The prepared ZIF-8 membrane exhibited a modest H-2 separation performance for H-2/CO2 and H-2/CO, with separation factors of 4.95 and 6.08, respectively, and a H-2 permeance of 7.81 x 10(-8) mol m(-2) s(-1) Pa-1 at 200 degrees C in the simulated biomass-derived syngas environments (H-2/CO2/CO) with the presence of steam. In particular, the H-2/CO2 and H-2/CO separation factors were increased by 36% and 97%, respectively, with respect to those obtained through bare supports. Despite the promising H2 perm-selectivity, the H-2/CO2 and H-2/CO separation factors of ZIF-8 membranes at 200 degrees C under water-containing syngas environments were maintained up to 10 h but the longer exposure led to the gradual degradation and eventual reduction toward those of bare supports after 15 h seemingly due to the water-involved membrane degradation. This study provides the availability and limitation of ZIF-8 membranes for H-2 separations in stimulated biomass-derived syngas environments. (C) 2015 Elsevier Inc. All rights reserved.</P>

Preparation of [bis(amido)-phosphine] and [amido-phosphine sulfide or oxide] hafnium and zirconium complexes for olefin polymerization

Lee, C.S.,Park, J.H.,Hwang, E.Y.,Park, G.H.,Go, M.J.,Lee, J.,Lee, B.Y. Elsevier Sequoia 2014 Journal of organometallic chemistry Vol.772 No.-

New phosphine-based bidentate ligands, 2-Me-8-Ph<SUB>2</SUB>P(X)C<SUB>9</SUB>H<SUB>8</SUB>NH (3, X = O; 4, X = S) and N-R-2-Ph<SUB>2</SUB>P(X)C<SUB>6</SUB>H<SUB>4</SUB>NH (5, R = Et, X = O; 6, R = Me, X = S; 7, R = Et, X = S) were prepared via ortho-lithiation of 1,2,3,4-tetrahydroquinaldine (2-Me-C<SUB>9</SUB>H<SUB>9</SUB>NH) and aniline derivatives (N-R-C<SUB>6</SUB>H<SUB>5</SUB>NH). Reaction of the ortho-lithiated compounds with 0.5 equiv of PhP(OPh)<SUB>2</SUB> afforded the bis(amido)-phosphine ligands (2-Me-C<SUB>9</SUB>H<SUB>8</SUB>NH-8-yl)<SUB>2</SUB>PPh (8) and (N-R-C<SUB>6</SUB>H<SUB>4</SUB>NH-2-yl)<SUB>2</SUB>PPh (9, R = Me; 10, R = Et). Using these ligands, [amido-phosphine oxide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB>, [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB>, [bis(amido)-phosphine]MX<SUB>2</SUB> (M = Hf, Zr; X = CH<SUB>2</SUB>Ph, Cl, Me), and [amido-phosphine-amine]MCl<SUB>3</SUB> complexes were prepared. The molecular structures of [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> (13) (prepared using 6), [bis(amido)-phosphine]ZrMe<SUB>2</SUB> (22) (prepared using 8), and [amido-phosphine-amine]MCl<SUB>3</SUB> (23, M = Hf; 24, M = Zr; prepared using 9) were confirmed by X-ray crystallography. Most of the prepared complexes exhibited negligible or low activity for ethylene/1-octene copolymerization. The [amido-phosphine sulfide]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> complex (13) exhibited relatively high copolymerization activity (19 x 10<SUP>6</SUP> g/mol-Hf h); however, this activity was unsatisfactory compared to that of the related [amido-phosphine]Hf(CH<SUB>2</SUB>Ph)<SUB>3</SUB> complexes (up to 48 x 10<SUP>6</SUP> g/mol-Hf h).

Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II

Lee, K‐,E,Kang, H‐,Y,Lee, S‐,K,Yoo, S‐,H,Lee, J‐,C,Hwang, Y‐,H,Nam, KH,Kim, J‐,S,Park, J‐,C,Kim, J‐,W Blackwell Publishing Ltd 2011 Clinical genetics Vol.79 No.4

<P>Lee K‐E, Kang H‐Y, Lee S‐K, Yoo S‐H, Lee J‐C, Hwang Y‐H, Nam KH, Kim J‐S, Park J‐C, Kim J‐W. Novel dentin phosphoprotein frameshift mutations in dentinogenesis imperfecta type II.</P><P>The dentin sialophosphoprotein (<I>DSPP</I>) gene encodes the most abundant non‐collagenous protein in tooth dentin and DSPP protein is cleaved into several segments including the highly phosphorylated dentin phosphoprotein (DPP). Mutations in the <I>DSPP</I> gene have been solely related to non‐syndromic form of hereditary dentin defects. We recruited three Korean families with dentinogenesis imperfecta (DGI) type II and sequenced the exons and exon–intron boundaries of the <I>DSPP</I> gene based on the candidate gene approach. Direct sequencing of PCR products and allele‐specific cloning of the highly repetitive exon 5 revealed novel single base pair (bp) deletional mutations (c.2688delT and c.3560delG) introducing hydrophobic amino acids in the hydrophilic repeat domain of the DPP coding region. All affected members of the three families showed exceptionally rapid pulp chambers obliteration, even before tooth eruption. Individuals with the c.3560delG mutation showed only mild, yellowish tooth discoloration, in contrast to the affected individuals from two families with c.2688delT mutation. We believe that these results will help us to understand the molecular pathogenesis of DGI type II as well as the normal process of dentin biomineralization.</P>