흐름주입법에 의한 Melamine 정량을 위한 Ruthenium-Ce(IV) 시스템의 백금 나노입자 증강 화학발광

이상학 ( Sang Hak Lee ),오상협 ( Sang Hyub Oh ),김영호 ( Young Ho Kim ),( M. Mahabub Khan ),( M. Arifur Rahman ),( Al Mahmnur Alam ),( Mohammad Kamruzzaman ) 한국공업화학회 2012 응용화학 Vol.16 No.1

A chemiluminescence (CL) method is reported for the determination of melamine by flow injection analysis (FIA). This method is based on the reaction of melamine with Ru(bipy)3 2+ and Ce(IV) in presence of colloidal platinum nanopartilces to produce CL. Under optimal condition, CL intensity was linearly related with melamine concentration. The calibration curve was linear over the range of 5.0×10-9-2.0×10-6 M with the limit of detection, 9.8×10-9 M. The relative standard deviation of 1.0×10-7 M melamine was found 2.5% (n=10).

Distribution of natural and anthropogenic radionuclides in northwest Mediterranean coastal sediments

Lee, Sang-Han,Povinec, Pavel P.,Chisholm, John R.M.,Levy, Isabelle,Miquel, Juan-Carlos,Oh, Jung-Suk Elsevier 2017 JOURNAL OF ENVIRONMENTAL RADIOACTIVITY Vol.172 No.-

<P><B>Abstract</B></P> <P>The distribution of radionuclides in NW Mediterranean coastal sediments, and the processes controlling their abundance were investigated in three cores taken near the island of Porquerolles and one offshore Monaco. The sediments collected near Porquerolles were strongly anoxic due to diagenetic processes involved in the decomposition of organic matter, whereas they transitioned from oxic to anoxic at a depth of 4 cm beneath the seawater interface at Monaco. Organic carbon (OC) was more abundant in sediments at Porquerolles (by about a factor of 3–5) than at Monaco and elsewhere in the coastal NW Mediterranean. Sediment cores collected NE of Porquerolles also possessed elevated uranium concentrations that correlated with high OC content and strong reducing conditions. The <SUP>239,240</SUP>Pu and <SUP>241</SUP>Am activities in surficial sediments ranged from 1 to 5.7 Bq kg<SUP>−1</SUP> and 0.3 to 1 Bq kg<SUP>−1</SUP>, respectively, while the <SUP>137</SUP>Cs activity ranged from 0.3 to 6.2 Bq kg<SUP>−1</SUP>. The mean activity ratios of <SUP>241</SUP>Am/<SUP>239,240</SUP>Pu and <SUP>238</SUP>Pu/<SUP>239,240</SUP>Pu in Porquerolles and Monaco sediments were similar to the global fallout ratios. Sediment inventories of global fallout <SUP>239,240</SUP>Pu (430–800 Bq m<SUP>−2</SUP>) and <SUP>241</SUP>Am (150–285 Bq m<SUP>−2</SUP>) were by about a factor of 5–10 higher at Porquerolles, whereas the inventory of <SUP>137</SUP>Cs (430–1000 Bq m<SUP>−2</SUP>) was substantially lower at the investigated stations than have been reported elsewhere at similar latitudes. Specific local conditions characterised by high OC sediment loads due to the growth and mortality of <I>Posidonia oceanica</I> have been responsible for deposition of large amounts of seagrass tissues at the NE corner of Porquerolles, which have had a profound effect on the distribution of radionuclides in the sediments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Radionuclides in coastal sediments of NW Mediterranean were investigated. </LI> <LI> <SUP>241</SUP>Am/<SUP>239,240</SUP>Pu and <SUP>238</SUP>Pu/<SUP>239,240</SUP>Pu ratios consistent with global fallout ratios. </LI> <LI> <SUP>137</SUP>Cs mostly dissolved, but <SUP>239,240</SUP>Pu and <SUP>241</SUP>Am are particle reactive elements. </LI> <LI> Inventories of <SUP>239,240</SUP>Pu (430–800 Bq m<SUP>−2</SUP>) and <SUP>241</SUP>Am (150–285 Bq m<SUP>−2</SUP>) are high. </LI> <LI> Inventories of <SUP>137</SUP>Cs are significantly lower at all stations investigated. </LI> </UL> </P>

Metal-organic frameworks as efficient catalytic systems for the synthesis of 1,5-benzodiazepines from 1,2-phenylenediamine and ketones

Timofeeva, M.N.,Panchenko, V.N.,Prikhod'ko, S.A.,Ayupov, A.B.,Larichev, Yu.V.,Khan, Nazmul Abedin,Jhung, Sung Hwa Academic Press 2017 Journal of catalysis Vol.354 No.-

<P><B>Abstract</B></P> <P>Benzodiazepines and their derivatives are a very important class of nitrogen-containing heterocyclic compounds with biological activity that are widely used in medicine. In this study, we demonstrated synthesis of 1,5-benzodiazepines from 1,2-phenylenediamine and ketones (acetone, cyclohexanone, acetophenone, methyl ethyl ketone) in the presence of isostructural porous metal-benzenetricarboxylates of the families MIL-100(M) (M: V<SUP>3+</SUP>, Al<SUP>3+</SUP>, Fe<SUP>3+</SUP> and Cr<SUP>3+</SUP>) and three porous aluminium trimesates Al-BTCs (MIL-96(Al), MIL-100(Al) and MIL-110(Al)). A combination of catalytic, theoretical and physicochemical methods showed that reaction rates and yields of 1,5-benzodiazepines were adjusted by the type of metal ions and accessibility of active sites. The yield of 1,5-benzodiazepines in the presence of MIL-100(M) was comparable with zeolites, such as HY, H-ZSM−5, β-zeolite and heulandite.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of 1,5-benzodiazepines over MIL-100(M), MIL-110 and MIL-96 was studied. </LI> <LI> Effect of Brønsted and Lewis acidity on MIL’s performance was investigated. </LI> <LI> Lewis acidity of MIL-100(Fe, Cr, Al, V) was studied by EPR spectroscopy. </LI> <LI> The type of M<SUP>3+</SUP>(Al, Fe, Cr, V) and structure of MILs affect the yield of product. </LI> <LI> MIL-100(M) samples perform well in compared with zeolites. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

미세각막절개도 헤드의 선택을 통한 맞춤식각막절개방식의 라식

강민호,송유미,강성민,박영숙,최철영,이윤정,이병로.Min Ho Kang. M.D.. Yoo Mi Song. M.D.. Sung Min Kang. M.D.. Young Sook Park. M.D.. Chul Young Choi. M.D.. Yoon Jung Lee. M.D.. Byung Ro Lee. M.D. 대한안과학회 2006 대한안과학회지 Vol.47 No.2

Purpose: To compare the intraoperative and postoperative complication rates and visual outcomes with M2 130 head (thick flap group) and M2 110 head (thin flap group). Methods: One-hundred-ninety-five eyes of 104 patients who underwent LASIK with the Moria M2 microkeratome and Allegretto-wave laser were reviewed retrospectively. Selection of M2 heads was based on preoperative pachymetry and estimated ablation depth. Intraoperative and postoperative flap-related complications, mean postoperative uncorrected visual acuity (UCVA), and mean spherical equivalent (MSE) were evaluated and compared. Results: Mean follow-up was 8.1 months. The number of eyes, preoperative MSE and mean corneal thickness of M2 130 were 115, -4.04±1.63diopter (D) and 549.40±39.16??m, and 85, -6.61±3.43D and 525.16±24.53 ?m, respectively, in the 110 head group. Mean UCVA and MSE at postoperative 1 week, 3 months and 6 months were 1.00±0.18, -0.26±0.49D; 1.07±0.68, -0.40±0.51D; and 1.01±0.22, -0.51±0.50D, respectively, in the 130 head group, and 0.90±0.23, -0.46±1.02D; 0.91±0.23, -0.67±0.79D; 0.85±0.46, -0.75±0.88D, respectively, in the 110 head group. There were no significant differences in intraoperative and postoperative flap-related complication rates between the two groups (p=0.316). There were no statistically significant differences in postoperative mean UCVA or MSE between the two groups (p>0.05), except for MSE at the third and sixth postoperative months (p=0.005, 0.013). Conclusions: Proper selection of M2 heads by preoperative pachymetry allowed for an adequate residual stroma bed with good visual outcome. Utilizing one single microkeratome and switching between two heads was advantageous and cost-effective.

Planck Cold Clumps in the <i>λ</i> Orionis Complex. II. Environmental Effects on Core Formation

Yi, Hee-Weon,Lee, Jeong-Eun,Liu, Tie,Kim, Kee-Tae,Choi, Minho,Eden, David,II, Neal J. Evans,Francesco, James Di,Fuller, Gary,Hirano, N.,Juvela, Mika,Kang, Sung-ju,Kim, Gwanjeong,M. Koch, Patrick,Lee, American Astronomical Society 2018 The Astrophysical journal, Supplement series Vol.236 No.2

<P>Based on the 850 mu m dust continuum data from SCUBA-2 at James Clerk Maxwell Telescope (JCMT), we compare overall properties of Planck Galactic Cold Clumps (PGCCs) in the lambda Orionis cloud to those of PGCCs in the Orion A and B clouds. The Orion A and B clouds are well-known active star-forming regions, while the A Orionis cloud has a different environment as a consequence of the interaction with a prominent OB association and a giant H-II region. PGCCs in the lambda Orionis cloud have higher dust temperatures (T-d = 16.13 +/- 0.15 K) and lower values of dust emissivity spectral index (beta = 1.65 +/- 0.02) than PGCCs in the Orion A (T-d = 13.79 +/- 0.21 K, beta = 2.07 +/- 0.03) and Orion B (T-d = 13.82 +/- 0.19 K, beta =1.96 +/- 0.02) clouds. We find 119 substructures within the 40 detected PGCCs and identify them as cores. Out of a total of 119 cores, 15 cores are discovered in the lambda Orionis cloud, while 74 and 30 cores are found in the Orion A and B clouds, respectively. The cores in the lambda Orionis cloud show much lower mean values of size R = 0.08 pc, column density N(H-2) (9.5 +/- 1.2) x 10(22)cm(-2) , number density n(H-2) - (2.9 +/- 0.4) x 10 5 CM -3 , and mass M-core = 1.0 +/- 0.3 M(circle dot)compared to the cores in the Orion A [R = 0.11 pc, N(H-2) = (2.3 +/- 0.3) x 10(23) cm(-2), n(H-2) = (3.8 +/- 0.5) x 10(5)cm(-3) , and M-core = 2.4 +/- 0.3 M-circle dot] and Orion B [R = 0.16 pc, N(H-2) (3.8 +/- 0.4) x 10(23) cm(-2), n(H-2) = (15.6 +/- 1.8) x 10(5) cm(-3) , and M-core = 2.7 +/- 0.3 M-circle dot] clouds. These core properties in the A Orionis cloud can be attributed to the photodissociation and external heating by the nearby H rr region, which may prevent the PGCCs from forming gravitationally bound structures and eventually disperse them. These results support the idea of negative stellar feedback on core formation.</P>

Characteristics of total gaseous mercury (TGM) concentrations in an industrial complex in South Korea: impacts from local sources

Seo, Yong-Seok,Jeong, Seung-Pyo,Holsen, Thomas M.,Han, Young-Ji,Choi, Eunhwa,Park, Eun Ha,Kim, Tae Young,Eum, Hee-Sang,Park, Dae Gun,Kim, Eunhye,Kim, Soontae,Kim, Jeong-Hun,Choi, Jaewon,Yi, Seung-Muk Copernicus GmbH 2016 Atmospheric Chemistry and Physics Vol.16 No.15

<P>Abstract. Total gaseous mercury (TGM) concentrations were measured every 5 min in Pohang, Gyeongsangbuk-do, Korea, during summer (17-23 August 2012), fall (9-17 October 2012), winter (22-29 January 2013), and spring (26 March-3 April 2013) to (1) characterize the hourly and seasonal variations of atmospheric TGM concentrations; (2) identify the relationships between TGM and co-pollutants; and (3) identify likely source directions and locations of TGM using the conditional probability function (CPF), conditional bivariate probability function (CBPF) and total potential source contribution function (TPSCF). The TGM concentration was statistically significantly highest in fall (6.7 ± 6.4 ng m−3), followed by spring (4.8 ± 4.0 ng m−3), winter (4.5 ± 3.2 ng m−3) and summer (3.8 ± 3.9 ng m−3). There was a weak but statistically significant negative correlation between the TGM concentration and ambient air temperature (r = −0.08, p<0.05). Although the daytime temperature (14.7 ± 10.0 °C) was statistically significantly higher than that in the nighttime (13.0 ± 9.8 °C) (p<0.05), the daytime TGM concentration (5.3 ± 4.7 ng m−3) was statistically significantly higher than that in the nighttime (4.7 ± 4.7 ng m−3) (p<0.01), possibly due to local emissions related to industrial activities and activation of local surface emission sources. The observed ΔTGM ∕ ΔCO was significantly lower than that of Asian long-range transport, but similar to that of local sources in Korea and in US industrial events, suggesting that local sources are more important than those of long-range transport. CPF, CBPF and TPSCF indicated that the main sources of TGM were iron and manufacturing facilities, the hazardous waste incinerators and the coastal areas. </P>

Interactive effect of indole-3-acetic acid and diethyl aminoethyl hexanoate on the growth and fatty acid content of some microalgae for biodiesel production

Salama, El-Sayed,Jeon, Byong-Hun,Chang, Soon Woong,Lee, Sang-hun,Roh, Hyun-Seog,Yang, Il-Seung,Kurade, Mayur B.,El-Dalatony, Marwa M.,Kim, Do-Hyeon,Kim, Ki-Hyun,Kim, Sunjoon Elsevier 2017 Journal of cleaner production Vol.168 No.-

<P><B>Abstract</B></P> <P>Enhancement of microalgal growth and fatty acid production is essential for development of a microalgae-based biodiesel production platform. Three different microalgal species (<I>Scenedesmus obliquus</I> GU732418, <I>Ourococcus multisporus</I> GU732424 and <I>Chlorella vulgaris</I> FR751187) were individually cultivated in media containing both indole-3-acetic acid (IAA) and diethyl aminoethyl hexanoate (DAH) at concentrations of 10<SUP>−8</SUP>−10<SUP>−4</SUP> M. Combined phytohormones (10<SUP>−8</SUP> to 10<SUP>−5</SUP> M) increased the growth of all three species compared to growth in media without phytohormones. IAA and DAH supported the maximum growth of <I>S</I>. <I>obliquusi</I> (38.12 × 10<SUP>6</SUP> cells mL<SUP>−1</SUP>) at 10<SUP>−8</SUP> M, <I>O</I>. <I>multisporus</I> (85.89 × 10<SUP>6</SUP> cells mL<SUP>−1</SUP>) at 10<SUP>−6</SUP> M, and <I>C. vulgaris</I> (4.09 × 10<SUP>6</SUP> cells mL<SUP>−1</SUP>) at 10<SUP>−5</SUP> M. Addition of 10<SUP>−7</SUP> M IAA and DAH also assisted the removal of Zn<SUP>2+</SUP> (97%), K<SUP>+</SUP> (88%) and Mg<SUP>2+</SUP> (99%) from the media by <I>S</I>. <I>obliquus</I>. The highest removal of Zn<SUP>2+</SUP>, K<SUP>+</SUP>, and Mg<SUP>2+</SUP> by <I>C</I>. <I>vulgaris</I> was achieved at 10<SUP>−5</SUP> M IAA and DAH. Under all experimental conditions (10<SUP>−8</SUP>−10<SUP>−4</SUP> M IAA and DAH) the amounts of poly-unsaturated fatty acids were significantly increased. Palmitic acid, linoleic acid and γ-linolenic acid were the major fatty acids, accounting for 11.75–21.55%, 2.55–6.73%, and 52.93–75.89% of the total fatty acid content, respectively. The fatty acids that accumulated in <I>O</I>. <I>multisporus</I> and <I>C</I>. <I>vulgaris</I> were found to be suitable for production of high quality biodiesel with characteristics equivalent to crop seed oil-derived biodiesel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> IAA and DAH in the range of 10<SUP>−8</SUP>−10<SUP>−5</SUP> M enhanced the growth of algae. </LI> <LI> PUFAs was increased by growth in medium containing both IAA and DAH. </LI> <LI> Accumulated fatty acids in algae are suitable for production of high quality biodiesel. </LI> </UL> </P>

Effect of Fe Doping on Ferroelectric and Ferromagnetic Properties of Sr0.5Ba0.5Nb2-xFexO6 Ceramics

Sung Yong Cho,Jin Soo Kim,M. S. Jang,Sang-Bock Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

Tungsten bronze structured Sr0.5Ba0.5Nb2.xFexO6 (SBNF) ceramics are prepared by a solidstate reaction method, and their dielectric constant and ferroelectric and ferromagnetic hysteresis loops are measured in the composition range from x = 0 to x = 0.2. The presence of single phases of SBNF ceramics is confirmed by X-ray diffraction. The phase transition temperature of SBNF ceramics shifts toward low temperature with an increase in Fe concentration. Particularly, the SBNF ceramics with low Fe doping exhibit a ferroelectric P-E and a ferromagnetic M-H hysteresis loops. The effect of Fe doping on the dielectric, ferroelectric, and ferromagnetic properties of Sr0.5Ba0.5Nb2.xFexO6 ceramics is investigated.l

Study of historical Chinese lacquer culture and technology - Analysis of Chinese Qin-Han dynasty lacquerware

Sung, M.,Jung, J.,Lu, R.,Miyakoshi, T. Elsevier 2016 Journal of cultural heritage Vol.21 No.-

<P>A Chinese Qin-Han dynasty lacquerware was analyzed by cross-section, field emission scanning electron microscope with energy dispersive X-ray spectrometry (EDX), strontium isotope ratios (Sr-87/Sr-86), carbon-14 age determination, and pyrolysis-gas chromatography-mass spectrometry. The carbon-14 analysis results showed that the wood base was from a Zelkova schneideriana tree grown in the Yangtze River area about 2300 years ago, and the film was sap collected from lacquer tree about 2200-2250 years ago. The Sr-87/Sr-86 isotope ratio was 0.71146 consistent with that of the Chinese mainland ( >0.71). Pyrolysis GC-MS detected 3-heptylphenol and 3-pentadecylphenol in the mass chromatograms at m/z=108, and palmitic acid and stearic acid were detected at m/z=60, suggesting that the sap collected from Toxicodendron vernicifluum tree and that many additives had been added. The cross-section and EDX revealed the coating technique and pigment species of lacquerware. Based on these results, the Chinese Qin-Han Dynasty lacquer culture is discussed. (C) 2016 Elsevier Masson SAS. All rights reserved.</P>

Evaluation of Volatile Compounds Isolated from Pork Loin (Longissimus dorsi) as Affected by Fiber Type of Solid-phase Microextraction (SPME), Preheating and Storage Time

Sung Yong Park,Young Mo Yoon,M. Wes Schilling,Koo Bok Chin 한국축산식품학회 2009 한국축산식품학회지 Vol.29 No.5

This study was conducted to investigate the effects of heating, fiber type used in solid-phase microextraction (SPME, two phase vs three phase) and storage time on the volatile compounds of porcine M. longissimus dorsi (LD). Volatile compounds were measured using a gas chromatography and mass spectrometry (GC/MS) with a quadrupole mass analyzer. Among the volatile compounds identified, aldehydes (49.33%), alcohols (24.63%) and ketones (9.85%) were higher in pre-heated loins (100oC/30 min), whereas, alcohols (34.33%), hydrocarbons (22.84%) and ketones (16.88%) were higher in non-heated loins. Heating of loins induced the formation of various volatile compounds such as aldehydes (hexanal) and alcohols. The total contents of hydrocarbons, alcohols, and carboxylic acids were higher in two phase fibers, whereas those of esters tended to be higher in three-phase fibers (p<0.05). Most volatile compounds increased (p<0.05) with increased storage time. Thus, the analysis of volatile compounds were affected by the fiber type, while heating and refrigerated storage of pork M. longissimus dorsi increased the volatile compounds derived from lipid oxidation and amino acid catabolism, respectively. This study was conducted to investigate the effects of heating, fiber type used in solid-phase microextraction (SPME, two phase vs three phase) and storage time on the volatile compounds of porcine M. longissimus dorsi (LD). Volatile compounds were measured using a gas chromatography and mass spectrometry (GC/MS) with a quadrupole mass analyzer. Among the volatile compounds identified, aldehydes (49.33%), alcohols (24.63%) and ketones (9.85%) were higher in pre-heated loins (100oC/30 min), whereas, alcohols (34.33%), hydrocarbons (22.84%) and ketones (16.88%) were higher in non-heated loins. Heating of loins induced the formation of various volatile compounds such as aldehydes (hexanal) and alcohols. The total contents of hydrocarbons, alcohols, and carboxylic acids were higher in two phase fibers, whereas those of esters tended to be higher in three-phase fibers (p<0.05). Most volatile compounds increased (p<0.05) with increased storage time. Thus, the analysis of volatile compounds were affected by the fiber type, while heating and refrigerated storage of pork M. longissimus dorsi increased the volatile compounds derived from lipid oxidation and amino acid catabolism, respectively.