PEDIATRIC DENTISTRY-PAST, PRESENT AND FUTURE

McDonald, Ralph E. 大韓小兒齒科學會 1990 大韓小兒齒科學會誌 Vol.17 No.2

Sulfur versus Iron Oxidation in an Iron−Thiolate Model Complex

McDonald, Aidan R.,Bukowski, Michael R.,Farquhar, Erik R.,Jackson, Timothy A.,Koehntop, Kevin D.,Seo, Mi Sook,De Hont, Raymond F.,Stubna, Audria,Halfen, Jason A.,Mü,nck, Eckard,Nam, Wonwoo,Que, American Chemical Society 2010 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.132 No.48

<P>In the absence of base, the reaction of [Fe<SUP>II</SUP>(TMCS)]PF<SUB>6</SUB> (<B>1</B>, TMCS = 1-(2-mercaptoethyl)-4,8,11-trimethyl-1,4,8,11-tetraazacyclotetradecane) with peracid in methanol at −20 °C did not yield the oxoiron(IV) complex (<B>2</B>, [Fe<SUP>IV</SUP>(O)(TMCS)]PF<SUB>6</SUB>), as previously observed in the presence of strong base (KO<SUP>t</SUP>Bu). Instead, the addition of 1 equiv of peracid resulted in 50% consumption of <B>1</B>. The addition of a second equivalent of peracid resulted in the complete consumption of <B>1</B> and the formation of a new species <B>3</B>, as monitored by UV−vis, ESI-MS, and Mössbauer spectroscopies. ESI-MS showed <B>3</B> to be formulated as [Fe<SUP>II</SUP>(TMCS) + 2O]<SUP>+</SUP>, while EXAFS analysis suggested that <B>3</B> was an O-bound iron(II)−sulfinate complex (Fe−O = 1.95 Å, Fe−S = 3.26 Å). The addition of a third equivalent of peracid resulted in the formation of yet another compound, <B>4</B>, which showed electronic absorption properties typical of an oxoiron(IV) species. Mössbauer spectroscopy confirmed <B>4</B> to be a novel iron(IV) compound, different from <B>2</B>, and EXAFS (Fe?O = 1.64 Å) and resonance Raman (ν<SUB>Fe?O</SUB> = 831 cm<SUP>−1</SUP>) showed that indeed an oxoiron(IV) unit had been generated in <B>4</B>. Furthermore, both infrared and Raman spectroscopy gave indications that <B>4</B> contains a metal-bound sulfinate moiety (ν<SUB>s</SUB>(SO<SUB>2</SUB>) ≈ 1000 cm <SUP>−1</SUP>, ν<SUB>as</SUB>(SO<SUB>2</SUB>) ≈ 1150 cm <SUP>−1</SUP>). Investigations into the reactivity of <B>1</B> and <B>2</B> toward H<SUP>+</SUP> and oxygen atom transfer reagents have led to a mechanism for sulfur oxidation in which <B>2</B> could form even in the absence of base but is rapidly protonated to yield an oxoiron(IV) species with an uncoordinated thiol moiety that acts as both oxidant and substrate in the conversion of <B>2</B> to <B>3</B>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2010/jacsat.2010.132.issue-48/ja1045428/production/images/medium/ja-2010-045428_0015.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja1045428'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja1045428'>ACS Electronic Supporting Info</A></P>

Test of the Rational Expectations Hypothesis in Korea : Determinants of Real GNP Fluctuations in Korea

McDONALD, Judy,Min, Hong Ghi THE INSTITUTE OF EAST AND WEST STUDIES YONSEI UNIV 1990 Global economic review Vol.19 No.1

Capture of Carbon Dioxidefrom Air and Flue Gas inthe Alkylamine-Appended Metal–Organic Framework mmen-Mg₂(dobpdc)

McDonald, ThomasM.,Lee, Woo Ram,Mason, Jarad A.,Wiers, Brian M.,Hong, Chang Seop,Long, Jeffrey R. American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.16

<P>Two new metal organic frameworks, M-2(dobpdc) (M = Zn (1), Mg (2); dobpdc(4-) = 4,4'-dioxido-3,3'-biphenyldicarboxylate), adopting an expanded MOF-74 structure type, were synthesized via solvothermal and microwave methods. Coordinatively unsaturated Mg2+ cations lining the 18.4-angstrom-diameter channels of 2 were functionalized with N,N'-dimethylethylenediamine (mmen) to afford Mg-2(dobpdc)-(mmen)(1.6)(H2O)(0.4) (mmen-Mg-2(dobpdc)). This compound displays an exceptional capacity for CO2 adsorption at low pressures, taking up 2.0 mmol/g (8.1 wt %) at 0.39 mbar and 25 degrees C, conditions relevant to removal of CO2 from air, and 3.14 mmol/g (12.1 wt %) at 0.15 bar and 40 degrees C, conditions relevant to CO2 capture from flue gas. Dynamic gas adsorption/desorption cycling experiments demonstrate that mmen-Mg-2(dobpdc) can be regenerated upon repeated exposures to simulated air and flue gas mixtures, with cycling capacities of 1.05 mmol/g (4.4 wt %) after 1 h of exposure to flowing 390 ppm CO2 in simulated air at 25(degrees)C and 2.52 mmol/g (9.9 wt %) after 15 min of exposure to flowing 15% CO2 in N-2 at 40 degrees C. The purity of the CO2 removed from dry air and flue gas in these processes was estimated to be 96% and 98%, respectively. As a flue gas adsorbent, the regeneration energy was estimated through differential scanning calorimetry experiments to be 2.34 MJ/kg CO2 adsorbed. Overall, the performance characteristics of mmen-Mg-2(dobpdc) indicate it to be an exceptional new adsorbent for CO2 capture, comparing favorably with both amine-grafted silicas and aqueous amine solutions.</P>

Korea's Growth and Her International Relations

McDonald.Donald S 연세대학교 동서문제연구소 1986 東西硏究 JOURNAL OF EAST AND WEST STUDIES Vol.15 No.2

In conclusion, let me summarize the points I have made. The modern international order can be visualized as a system in which the many national actors relate to one another by mutual demands and responses. Each state, by applying its own levers of national power and capability, seeks to maximize its benefits in this interplay of demands and responses. in doing so, hewever, it must concern itself not only with its own needs and internal equilibrium, but also with international equilibrium.

세계적 문제와 인간환경 개선

Mcdonald, Gordon 대한지방행정공제회 1971 도시문제 Vol.6 No.11

Thermal decomposition pathways of nitro-functionalized metal-organic frameworks

McDonald, K.,Ko, N.,Noh, K.,Bennion, J.,Kim, J.,Matzger, A. Royal Society of Chemistry 2017 Chemical communications Vol.53 No.55

Effects of alfalfa and alfalfa-grass mixtures with nitrogen fertilization on dry matter yield and forage nutritive value

( Iryna Mcdonald ),( Rudra Baral ),( Doohong Min ) 한국축산학회(구 한국동물자원과학회) 2021 한국축산학회지 Vol.63 No.2

Alfalfa (Medicago sativa L.) is an important forage legume grown in Kansas, USA and its productivity with cool-season grasses however is unknown. The objective of this study was to determine the dry matter yield (DMY) and forage nutritive value of alfalfa-grass mixtures compared to those of alfalfa and grasses grown in monoculture with and without nitrogen fertilization. Three different alfalfa varieties were planted (reduced-lignin alfalfa, Roundup Ready, and conventional alfalfa) and two kinds of cool-season grasses (smooth brome, Bromus inermis Leyss, and tall fescue, Festuca arundinacea Schreb) were planted as a monoculture or in alfalfa-grass mixtures. Nitrogen fertilizer (urea) was applied at green-up at a rate of 56 kg/ha and after the second cutting at a rate of 56 kg/ha in 2016 and 2017, respectively. and control treatments received no nitrogen. DMY was significantly higher in monoculture alfalfa and alfalfa-grass mixtures than in grass monocultures. Between alfalfa monoculture and alfalfa-grass mixtures, no significant differences in DMY were found. For all treatments, nitrogen application significantly increased DMY compared to the control. In 2016 and 2017, the low-lignin alfalfa monoculture had the lowest acid detergent fiber (ADF) and the grass monocultures had the highest ADF. In 2016 and 2017, neutral detergent fiber (NDF) in smooth bromegrass and tall fescue was higher than in other species treatments. A low-lignin alfalfa monoculture had significantly lower NDF concentration compared to alfalfa-grass mixtures. When averaged over 2016 and 2017, relative feed value (RFV) was highest in low-lignin alfalfa and lowest in the grass monocultures. In both years, nitrogen fertilizer application did not affect nutritive values.

“Misted and Married Together”?: Diasporic Consciousness and Textual Form in Nineteenth-Century Irish Emigrant Letters from Australia

( Ronan Mcdonald ) 한국영어영문학회 2014 영어 영문학 Vol.60 No.4

This essay considers a selection of letters home to Ireland written by Irish emigrants to Australia in the second half of the nineteenth century, extracted from David Fitzpatrick’s acclaimed anthology, Oceans of Consolation (1994). It attends particularly to the descriptions of encounters with other ethnicities and races and to the challenges to the values of home posed by the opportunities of the new environment. Informed by theories of diasporic consciousness, and deploying methods of close textual anaylsis, it seeks to identify the ambivalent and layered nature of cultural encounter, veering as they do between recoil and attraction, even in the same sentence. It attends to the crisis of representation that these encounters often engender, struggling to articulate levels of experience outside the inherited discursive frames and within the straitened and conservative textual conventions of the “letter home.” In seeking to delineate an emergent diasporic consciousness, it discerns numerous productive and revealing tensions as value systems, and principles of allegiance and affiliation, shift, mutate and conflict. It finds complex compromises between home and away, a deracinated identity that alternately embraces and resists alternate cultures and values and that, often consciously, wagers familiar and familial values against the self-advancement and opportunity promised by capitalist structures in the new colonies.

Effect of a fall cut on dry matter yield, nutritive value, and stand persistence of alfalfa

( Iryna Mcdonald ),( Doohong Min ),( Rudra Baral ) 한국축산학회(구 한국동물자원과학회) 2021 한국축산학회지 Vol.63 No.4

Information is lacking about the effect of date of a fall cut of alfalfa (Medicago sativa L.) on dry matter yield (DMY), forage nutritive value, and stands persistence. The objective of this study was to determine the effect of timing of a fall cut on DMY, forage nutritive value and stand persistence of three alfalfa varieties: low-lignin Hi-Gest 360, Roundup Ready Tonica, and conventional Gunner in Northeastern Kansas in the United States. The field study was carried out by splitting plot in randomized complete block design with four replications. The harvesting data of different maturity stages were collected in each year from 2015 to 2018. Three cuts were harvested based on the stage of maturity, and the last (fourth) cut was done on September 15, September 30, October 15, and October 30 of each year. The persistence of the alfalfa stands was determined each fall after the last cut, and each spring after the first cut, by counting the number of live plants in a randomly placed quadrat in each plot. Alfalfa cut on September 15 and September 30 had a higher stand persistence compared to alfalfa cut on October 15 and October 30. The DMY of the first cut in 2016 was significantly higher in roundup ready than the low-lignin alfalfa variety. In the second cut, DMY was significantly higher in conventional alfalfa than the roundup ready. There were no significant differences in DMY between alfalfa varieties in the rest of seasonal cuttings in 2016 and 2017 and annual total yield in both years. In general, low lignin alfalfa variety had higher crude protein and relative feed value and lower acid detergent fiber and neutral detergent fiber contents than those in roundup ready and conventional alfalfa varieties. On average, nutritive value of alfalfa was generally affected by last cutting dates in 2017. Based on 3-year data the last cutting of alfalfa in the fall could be done by September 30-October 15 without harmful effect on DMY.