Pressure-assisted combustion synthesis of red-emitting SrIn₂O₄: Eu3+ phosphor powders for applications in solid state white lamps

C.E. Rodríguez-García,N. Perea-López,S.P. DenBaars,G.A. Hirata 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.5

Red-emitting phosphor powders of SrIn2O4 activated with Eu3+ ions were synthesized by a high pressure assisted combustion method. X-ray diffraction analysis of the crystalline properties of these powders revealed single phase SrIn2O4 for Eu concentrations up to 4 atomic % of Eu. The photo and cathodoluminescence emission spectra of SrIn2O4: Eu3+ powder shows bright red emission mainly caused by the 5D0→7F2 intra-shell transition of Eu3+. Furthermore, photoluminescence excitation (PLE) spectroscopy revealed that an efficient energy transfer from the SrIn2O4 host lattice onto the Eu ions is accomplished in addition to the excitation band peaked at λ = 396 nm that directly excites the Eu ions, making this material an excellent candidate for applications in solid state white-emitting lamps. Red-emitting phosphor powders of SrIn2O4 activated with Eu3+ ions were synthesized by a high pressure assisted combustion method. X-ray diffraction analysis of the crystalline properties of these powders revealed single phase SrIn2O4 for Eu concentrations up to 4 atomic % of Eu. The photo and cathodoluminescence emission spectra of SrIn2O4: Eu3+ powder shows bright red emission mainly caused by the 5D0→7F2 intra-shell transition of Eu3+. Furthermore, photoluminescence excitation (PLE) spectroscopy revealed that an efficient energy transfer from the SrIn2O4 host lattice onto the Eu ions is accomplished in addition to the excitation band peaked at λ = 396 nm that directly excites the Eu ions, making this material an excellent candidate for applications in solid state white-emitting lamps.

Effects of D-002, a mixture of high molecular weight beeswax alcohols, on patients with nonalcoholic fatty liver disease

José Illnait,Iván Rodríguez,Sarahí Mendoza,Yolanda Fernández,Rosa Mas,Mirtha Miranda,Jesús Piñera,Julio César Fernández,Meilis Mesa,Lilia Fernández,Daisy Carbajal,Rafael Gámez 대한내과학회 2013 The Korean Journal of Internal Medicine Vol.28 No.4

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) is intimately related to insulin resistance and ranges from a benign course to liver fibrosis and cirrhosis. NAFLD management mainly involves dietary modification and weight loss. Although no fully successful pharmacological intervention is available, alternative therapies to treat NAFLD have shown promising results. Experimental studies have shown that D-002, a mixture of beeswax alcohols with antioxidant effects, is hepatoprotective. The aim of this study was to investigate the efficacy and safety of D-002 in patients with NALFD. Methods: Fifty patients with NAFLD were randomized to receive a placebo or D-002 (100 mg/day) for 24 weeks. The primary endpoint was a significant ultrasonography-detected reduction of liver fat infiltration versus a placebo. Secondary endpoints were decreases in the homeostatic model assessment (HOMA) index,insulin levels, serum liver enzymes, increases in plasma total antioxidant status (TAS) and improved clinical symptoms versus the placebo recipients. Results: At randomization, all indicators were comparable in both groups. At study completion, seven (28.0%) D-002-patients, but none of the placebo recipients,exhibited a normal liver echo pattern on ultrasonography (p < 0.01). Also,D-002 significantly reduced (p < 0.01 vs. baseline and placebo) the HOMA index and insulin levels and increased the TAS, but did not affect other parameters. The proportion of D-002-patients (12/25, 48.0%) showing symptom improvement was higher (p < 0.001) than that of the placebo group (1/25, 4.0%). The treatment was safe and well tolerated. Three patients in each group withdrew from the study. Conclusions: D-002 (100 mg/day) improved ultrasonographic findings, indicators of insulin resistance, plasma TAS and clinical evolution on NAFLD patients. Further studies, however, are needed to confirm these results.

Internal modifications to reduce pollutant emissions from marine engines. A numerical approach

M.I. Lamas,C.G. Rodríguez,J.D. Rodríguez,J. Telmo 대한조선학회 2013 International Journal of Naval Architecture and Oc Vol.5 No.4

Taking into account the increasingly stringent legislation on emissions from marine engines, this work aims to analyze several internal engine modifications to reduce NOx (nitrogen oxides) and other pollutants. To this end,a numerical model was employed to simulate the operation cycle and characterize the exhaust gas composition. After a preliminary validation process was carried out using experimental data from a four-stroke, medium-speed marine engine,the numerical model was employed to study the influence of several internal modifications, such as water addition from 0 to 100% water to fuel ratios, exhaust gas recirculation from 0 to 100% EGR rates, modification of the overlap timing from 60 to 120°, modification of the intake valve closing from 510 to 570°, and modification of the cooling water temperature from 70 to 90 oC. NOx was reduced by nearly 100%. As expected, it was found that, by lowering the combustion temperature, there is a notable reduction in NOx, but an increase in CO (carbon monoxide), HC (hydrocarbons)and consumption.

A taxonomic and distributional study of the rhodolith-forming species Lithothamnion muelleri (Corallinales, Rhodophyta) in the Eastern Pacific Ocean

Néstor M. Robinson,G. I. Hansen,C. Fernández-García,R. Riosmena-Rodríguez 한국조류학회I 2013 ALGAE Vol.28 No.1

Lithothamnion muelleri is reported for the first time as one of the main components of rhodolith beds along the Eastern Pacific Ocean based on samples from Washington State (USA), Pacific Baja California (Mexico), southern Nicaragua, and Costa Rica. Individual rhodoliths ranged from fruticose to lumpy in morphology, and bi-sporangial, tetrasporangial, and gametangial plants were similar to those described from Australia and Brazil. Our study revealed a surprisingly wide latitudinal distribution of this species along the American continent. Its documentation in the Eastern Pacific will facilitate a more accurate interpretation of the ecology, biology, and biogeography of rhodolith beds worldwide.

Metal ion interaction of water-soluble copolymers containing carboxylic acid groups in aqueous phase by membrane filtration technique

Pizarro, Guadalupe Del C.,Marambio, Oscar G.,Jeria-Orell, Manuel,Huerta, Margarita R.,Rodrí,guez, Oscar O.,Rivas, Bernabé,L.,Geckeler, Kurt E. Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of applied polymer science Vol.105 No.5

<P>This article reports the synthesis of poly(N-maleoylglycine-co-itaconic acid) by radical copolymerization under different feed mole ratios and its properties to remove various metal ions, such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Pb(II), Cd(II), and Fe(III), in aqueous phase with the liquid-phase polymer-based retention(LPR) technique. The interactions of inorganic ions with the hydrophilic water-soluble polymer were determined as a function of pH and filtration factor. Metal ion retention was found to strongly depend on the pH. Metal ion retention increased as pH and MG content units in the macromolecular backbone increased. The copolymers were characterized by elemental analysis, FTIR, <SUP>1</SUP>H-NMR, and <SUP>13</SUP>C-NMR spectroscopy. Additionally, intrinsic viscosity, molecular weight, and polydispersity have been determined for the copolymers. Copolymer and polymer–metal complex thermal behavior was studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques under nitrogen atmosphere. The thermal decomposition temperatures (TDT) were influenced by the copolymer composition. The copolymers present lower TDT than the polymer–metal complex with the same copolymer composition. All copolymers present a single T<SUB>g</SUB>, indicating the formation of random copolymers. A slight deviation of the T<SUB>g</SUB> for the copolymers and its complexes can be observed. The copolymer T<SUB>g</SUB> is higher than the T<SUB>g</SUB> value for the polymer–metal complexes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007</P>