Determination of surface properties and Gutmann’s Lewis acidity–basicity parameters of thiourea and melamine polymerized graphitic carbon nitride sheets by inverse gas chromatography

Sreekanth, T.V.M.,Basivi, Praveen Kumar,Nagajyothi, P.C.,Dillip, G.R.,Shim, J.,Ko, T.J.,Yoo, K. Elsevier 2018 Journal of chromatography Vol.1580 No.-

<P><B>Abstract</B></P> <P>Melamine and thiourea-derived graphitic carbon nitrides (M-GCN/T-GCN) were synthesized and characterized. The surface properties were investigated using inverse gas chromatography (IGC) and compared. Net retention volumes of M-GCN and T-GCN were measured with <I>n</I>-alkanes (C<SUB>5</SUB>–C<SUB>10</SUB>) and polar probes. The London dispersive surface free energies ( γ s d ), calculated using Schultz and Dorris–Gray methods, decreased linearly with increasing temperature. The specific components of the enthalpy and entropy of adsorption for the polar probes were obtained using the Schultz, Dong, and Sawyer–Brookman methods. The Gutmann’s Lewis acid–base parameters, <I>K<SUB>a</SUB> </I> and <I>K<SUB>b</SUB> </I>, were determined using the surface free energy ( Δ G a S ) via these methods. The surface character ‘<I>S’</I> values (<I>K<SUB>b</SUB> </I>/<I>K<SUB>a</SUB> </I>) of M-GCN and T-GCN using the respective methods are 4.04, 3.78, and 5.08 and 4.11, 5.27, and 2.86. Hence, the surfaces contain more basic than acidic sites and could interact strongly with acidic media. Thus, IGC elucidates the surface charges of the GCN matrix resulting from surface chemical modification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Graphitic carbon nitride was synthesized using two precursors, melamine and thiourea. </LI> <LI> Physicochemical properties were confirmed by XRD, XPS and BET. </LI> <LI> Inverse gas chromatography was employed to understand surface free energy of GCN. </LI> <LI> The London dispersive parameters were determined by Schultz/Dorris–Gray methods. </LI> <LI> The Lewis acid–base parameters, showing the more basic character of GCN. </LI> </UL> </P>

Hysteresis and fast timescales in transport relations of toroidal plasmas

Itoh, K.,Itoh, S.-I.,Ida, K.,Inagaki, S.,Kamada, Y.,Kamiya, K.,Dong, J.Q.,Hidalgo, C.,Evans, T.,Ko, W.H.,Park, H.,Tokuzawa, T.,Kubo, S.,Kobayashi, T.,Kosuga, Y.,Sasaki, M.,Yun, G.S.,Song, S.D.,Kasuya, International Atomic Energy Agency 2017 Nuclear fusion Vol.57 No.10

<P>This article assesses current understanding of hysteresis in transport relations, and its impact on the field. The rapid changes of fluxes compared to slow changes of plasma parameters are overviewed for both core and edge plasmas. The modulation ECH experiment is explained, in which the heating power cycles on-and-off periodically, revealing hysteresis and fast changes in the gradient–flux relation. The key finding is that hystereses were observed simultaneously in both the the gradient–flux and gradient–fluctuation relations. Hysteresis with rapid timescale exists in the channels of energy, electron and impurity densities, and plausibly in momentum. Advanced methods of data analysis are explained. Transport hysteresis can be studied by observing the higher harmonics of temperature perturbation <img ALIGN='MIDDLE' ALT='$\delta T_{\rm m}$ ' SRC='http://ej.iop.org/images/0029-5515/57/10/102021/nfaa796aieqn001.gif'/> in heating modulation experiments. The hysteresis introduces the term <img ALIGN='MIDDLE' ALT='$\delta T_{\rm m}$ ' SRC='http://ej.iop.org/images/0029-5515/57/10/102021/nfaa796aieqn002.gif'/>, which depends on the harmonic number <I>m</I> in an algebraic manner (not exponential decay). Next, the causes of hysteresis and its fast timescale are discussed. The nonlocal-in-space coupling works here, but does not suffice. One mechanism for ‘the heating heats turbulence’ is that the external source <I>S</I> in phase space for heating has its fluctuation in turbulent plasma. This coupling can induce the direct input of heating power into fluctuations. The height of the jump in transport hysteresis is smaller for heavier hydrogen isotopes, and could be one of the origins of isotope effects on confinement. Finally, the impacts of transport hysteresis on the control system are assessed. Control systems must be designed so as to protect the system from sudden plasma loss.</P>

Observation ofB0→pp¯K*0with a LargeK*0Polarization

Chen, J.-H.,Wang, M.-Z.,Adachi, I.,Aihara, H.,Arinstein, K.,Aulchenko, V.,Aushev, T.,Bakich, A. M.,Balagura, V.,Barberio, E.,Bay, A.,Bedny, I.,Belous, K.,Bitenc, U.,Bondar, A.,Bozek, A.,Brač,ko, American Physical Society 2008 Physical review letters Vol.100 No.25

<P>Using a 492 fb{-1} data sample collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{+}e{-} collider, we observe the decay B{0}-->ppK*0 with a branching fraction of (1.18{-0.25}{+0.29}(stat)+/-0.11(syst))x10{-6}. We study the decay dynamics of B{0}-->ppK*0 and compare with B{+}-->ppK*+. The K*0 meson is found to be almost 100% polarized (with a fraction of (101+/-13+/-3)% in the helicity zero state), while the K*+ meson has a (32+/-17+/-9)% fraction in the helicity zero state. The direct CP asymmetries for B{0}-->ppK*0 and B{+}-->ppK*+ are measured to be -0.08+/-0.20+/-0.02 and -0.01+/-0.19+/-0.02, respectively. In addition, we report improved measurements of the branching fractions B(B{+}-->ppK*+)=(3.38{-0.60}{+0.73}+/-0.39)x10{-6} and B(B{0}-->ppK{0})=(2.51{-0.29}{+0.35}+/-0.21)x10{-6}, which supersede our previous measurements.</P>

醫藥品 添加劑에 관한 연구 (Ⅰ) : 防腐劑에 관한 硏究 Determination of Preservatives in Various Dosage Forms by HPLC

金炯局,姜讚淳,具永三,崔寶慶,朴承熺,文炳佑,尹泰奎,高健一 국립보건연구원 1989 국립보건원보 Vol.26 No.

Thermal and Electrical Stabilities of Solid Nitrogen (SN2) Cooled YBCO Coated Conductors for HTS Magnet Applications

Song, J B,Kim, K J,Kim, K L,Lee, J H,Kim, H M,Lee, G H,Chang, H M,Park, D K,Ko, T K,Lee, H G IEEE 2010 IEEE transactions on applied superconductivity Vol.20 No.3

<P>Recently, a cooling system using a solid cryogen such as solid nitrogen (SN2), was introduced for high temperature superconducting (HTS) magnet applications. In order to apply the SN2 cooling system successfully to HTS applications, it is essential to obtain sufficient data regarding the characteristics of the SN2-cooled YBCO-coated conductor (CC), including the thermal and electrical properties. Therefore, this study examined the effect of SN2 on the thermal/electrical stability of YBCO CC tape. The SN2 was produced by conduction cooling using a GM-cryocooler and cooled to 58 K. The voltages and temperatures of the YBCO CC tapes were measured while applying an over-current. The results showed that the thermal and electrical stability of the YBCO CC tape were improved considerably in the SN2 cooling system compared to that in the conduction cooling system.</P>

이력 데이타베이스를 위한 물리적 데이타베이스 설계

고병오(B. O. Ko),조태남(T. N. cho),김기룡(K. L. Kim) 한국정보과학회 1991 한국정보과학회 학술발표논문집 Vol.18 No.2

많은 기억장소를 요구하는 이력 데이타베이스를 효율적으로 저장하고 액세스하기 위하여 본 연구에서는 첫째, 시속성의 유효시간의 시작점(Start time)만을 기록 관리 하도록 하여 기억 공간을 최소로 사용하도록 하였으며 둘째, 빠른 액세스를 하기 위하여 주로 많이 사용되는 이력 데이타베이스의 현재 데이타 부분(NDP)에, 대하여는 종래의 관계 DB에서 주로 사용하는 방법대로 DATA화일은 비순서 힘 화일(unordered heep file)로 구성하고, 인덱스 화일은 B^+ tree를 이용한다. 이력 데이타베이스에만 존재하는 늙은 데이타 부분(ODP)은 유효시간(T)과 속성의 값(A)의 두 필드를 갖는데, 유효시간 T에 대한 질의에 응답을 하기 위하여 1년 전후의 갱신 주기를 갖는 장주기 속성은 순차적 화일로 편성하여 집중화(clustering)하고, 단주기 속성은 년, 월, 일 단위로 다단계 인덱스 화일(multi-level index file)로 편성할 것을 제안하였다. 그리고 A필드에 대한 질의에 빠른 응답을 하기 위하여 B^+ tree 방법을 이용하도록 하였다.

Search for the H Dibaryon in (K-, K+) Reactions

Bahk,S. Y.,Chung,K. S,Chung,S. H.,Funahashi,H.,Hahn,C. H.,Hara,T.,Hirata,S.,Hoshino,K.,Ieiri,M.,Iijima,T.,Imai,K.,Ishigami,T.,Itow,Y.,Kazuno,M.,Kikuchi,K.,Kim,C. O.,Kim,D. C.,Kim,J. Y.,Kobayashi,M.,Ko 國立昌原大學校 基礎科學硏究所 1992 基礎科學硏究所論文集 Vol.3 No.-

We have studied(??) reactions from an emulsion target. The S--2H dibaryon has been searched for by the analysis of the ??? momentum spectrum together with emulsion data. No evidence of H production was observed in the mass range of 1.90-2.16 GeV/c². Upper limits for the production cross section of the H are (0.2-0.6)% of that for the quasifree ??? production at the 90% confidence level.

6-Trifluoromethyl-2-thiouracil possesses anti-Toxoplasma gondii effect in vitro and in vivo with low hepatotoxicity

Choi, H.J.,Yu, S.T.,Lee, K.I.,Choi, J.K.,Chang, B.Y.,Kim, S.Y.,Ko, M.H.,Song, H.O.,Park, H. Academic Press 2014 Experimental parasitology Vol.143 No.-

Since pyrimethamine, the general therapeutic drug for toxoplasmosis, presents several adverse side effects, the need to develop and evaluate new drugs for the condition is critical. In this study, anti-Toxoplasma gondii activities of 3-[{2-((E)-furan-2-ylmethylene)hydrazinyl}methylene]-1,3-dihydroindol-2-one (ATT-5126) and 6-trifluoromethyl-2-thiouracil (KH-0562) were evaluated in vitro using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and in vivo by measuring amount of the tachyzoites in mice ascites. Biochemical parameters such as lipid peroxidation (LPO), glutathione (GSH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were also evaluated in livers of mice at 4days post-infection. As a result, the ATT-5126 and KH-0562 showed anti-T. gondii activity in vitro. Treatment of ATT-5126 or KH-0562 decreased the amount of tachyzoites in T. gondii infected ICR mice. The relative weight of liver and spleen increased by T. gondii infection were decreased by treatment of ATT-5126 or KH-0562. The levels of LPO, ALT and AST, which are biochemical parameters involved in liver injury, were also significantly recovered by treatment of ATT-5126 or KH-0562 (p<0.05). In particular, the recovered levels by KH-0562 were similar to those of pyrimethamine-treated group (p<0.05). However, the level of GSH, which is an antioxidant indicator, showed insignificant statistics. The results suggest that KH-0562 show anti-T. gondii activities in vitro and in vivo with low hepatotoxicity. Therefore, KH-0562 may be a useful candidate for treating T. gondii infection.

Elevated LDH and paranasal sinus involvement are risk factors for central nervous system involvement in patients with peripheral T-cell lymphoma

Yi, J. H.,Kim, J. H.,Baek, K. K.,Lim, T.,Lee, D. J.,Ahn, Y. C.,Kim, K.,Kim, S. J.,Ko, Y. H.,Kim, W. S. Oxford University Press 2011 ANNALS OF ONCOLOGY Vol.22 No.7

<P><B>Background:</B> The incidence and risk factors of central nervous system (CNS) involvement in peripheral T-cell lymphomas (PTCLs) are still unclear.</P><P><B>Patients and methods:</B> We analyzed 228 patients with PTCLs, excluding cases of extranodal natural killer/T-cell lymphoma and primary cutaneous T-cell lymphoma, by retrospectively collecting the clinical features and outcomes of the patients.</P><P><B>Results:</B> Twenty events (8.77%, 20/228) of CNS involvement were observed during a median follow-up period of 13.9 months (range 0.03–159.43). Based on univariate analysis, elevated serum lactate dehydrogenase (LDH) level [<I>P</I> = 0.019, relative risk (RR) 5.904, 95% confidence interval (CI) 1.334–26.123] and involvement of the paranasal sinus (<I>P</I> = 0.032, RR 3.137, 95% CI 1.105–8.908) adversely affect CNS involvement. In multivariate analysis, both were independently poor prognostic factors for CNS relapse [elevated LDH level: <I>P</I> = 0.011, hazard ratio (HR) 6.716, 95% CI 1.548–29.131; involvement of the paranasal sinus: <I>P</I> = 0.008, HR 3.784, 95% CI 1.420–10.083]. The survival duration of patients with CNS involvement was significantly shorter than that of the patients without CNS involvement (<I>P</I> = 0.009), with median overall survival of 7.60 months (95% CI of 4.92–10.28) versus 27.43 months (95% CI of 0.00–57.38), respectively.</P><P><B>Conclusions:</B> Elevated LDH level and involvement of the paranasal sinus are two risk factors for CNS involvement in patients with PTCLs. Considering the poor prognoses after CNS relapse, prophylaxis should be considered with the presence of any risk factor.</P>

공기취출방식에 따른 온열쾌적감 평가에 관한 연구

고경태,정석윤,김경훈 경희대학교 자연과학종합연구원 1998 자연과학논문집 Vol.4 No.-

The purpose of this study was to examine theory about indoor thermal comfort environment by air-conditioning system. Specially we laid emphasis on it that the under floor and the over ceiling air-conditioning systems had an effect on the thermal comfort. So we determined thermal sensation and physical responses for men in summer indoor environment, under various air temperature and relative humidity. As a result of this study we had about the comfortable range for SET^(*)=25.2℃, - 0.87 < PMV < +0.95 by the over ceiling air-conditioning system and had about it for SET^(*)=25.7℃, - 0.88 PMV < +0.96 by the under floor air-conditioning system.