WorldWideScience

Sample records for aqueous media renaissance

  1. Interfacial forces in aqueous media

    CERN Document Server

    van Oss, Carel J

    2006-01-01

    Thoroughly revised and reorganized, the second edition of Interfacial Forces in Aqueous Media examines the role of polar interfacial and noncovalent interactions among biological and nonbiological macromolecules as well as biopolymers, particles, surfaces, cells, and both polar and apolar polymers. The book encompasses Lifshitz-van der Waals and electrical double layer interactions, as well as Lewis acid-base interactions between colloidal entities in polar liquids such as water. New in this Edition: Four previously unpublished chapters comprising a new section on interfacial propertie

  2. Mukaiyama Aldol Reactions in Aqueous Media

    OpenAIRE

    Kitanosono, Taku; Kobayashi, Shū

    2013-01-01

    Mukaiyama aldol reactions in aqueous media have been surveyed. While the original Mukaiyama aldol reactions entailed stoichiometric use of Lewis acids in organic solvents under strictly anhydrous conditions, Mukaiyama aldol reactions in aqueous media are not only suitable for green sustainable chemistry but are found to produce singular phenomena. These findings led to the discovery of a series of water-compatible Lewis acids such as lanthanide triflates in 1991. Our understanding on these be...

  3. Recycled Renaissance

    Science.gov (United States)

    Armstrong, Wendy

    2010-01-01

    One of the author's goals this year was to turn all of the different pieces of research she has collected throughout the years into projects. This is when she thinks of bringing Renaissance quilling to her class. Quilling, or paper scrolling, uses strips of paper that are rolled up to create decorative designs. During the Renaissance, it was used…

  4. Reductive amination with zinc powder in aqueous media

    OpenAIRE

    Giovenzana, Giovanni B.; Daniela Imperio; Andrea Penoni; Giovanni Palmisano

    2011-01-01

    Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

  5. Reductive amination with zinc powder in aqueous media

    Directory of Open Access Journals (Sweden)

    Giovanni B. Giovenzana

    2011-08-01

    Full Text Available Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents.

  6. Propargylamine-isothiocyanate reaction: efficient conjugation chemistry in aqueous media

    DEFF Research Database (Denmark)

    Viart, Helene Marie-France; Larsen, T. S.; Tassone, Chiara;

    2014-01-01

    A coupling reaction between secondary propargyl amines and isothiocyanates in aqueous media is described. The reaction is high-yielding and affords cyclized products within 2-24 h. A functionalized ether lipid was synthesized in 8 steps, formulated as liposomes with POPC and conjugated to FITC un...

  7. Aqueous Media Oxidation of Alcohols with Ammonium Persulfate

    Institute of Scientific and Technical Information of China (English)

    IMANZADEH, Gholam Hassan; ZAMANLOO, Mohammad R.; MANSOORI, Yaghoob; KHODAYARI, Ali

    2007-01-01

    Oxidation of series of various primary and secondary alcohols to corresponding carbonyl compounds with ammonium persulfate in aqueous media was described. No over oxidation of primary alcohols to carboxylic acids and secondary alcohols to esters was observed. Under such conditions benzoin was converted to benzoic acid.

  8. Suspension polymerization of aniline hydrochloride in non-aqueous media

    Czech Academy of Sciences Publication Activity Database

    Konyushenko, Elena; Stejskal, Jaroslav; Trchová, Miroslava; Prokeš, J.

    2011-01-01

    Roč. 60, č. 5 (2011), s. 794-797. ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500905; GA AV ČR IAA100500902 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymer * polyaniline * non-aqueous media Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.902, year: 2011

  9. Colloidal stability of gadolinium-doped ceria powder in aqueous and non-aqueous media

    OpenAIRE

    López-Robledo, M. J.; Silva-Treviño, J.; Molina, Tamara; Moreno, Rodrigo

    2013-01-01

    In this work the colloidal behaviour of Ce0.9Gd0.1O2-δ powder in aqueous and non-aqueous media (ethanol) is studied. Commercial powder was characterised by particle size distribution, specific surface area measurements, X-ray diffraction and scanning electron microscopy. Diluted suspensions were characterised by particle size distribution and zeta potential, using dynamic light scattering and laser Doppler velocimetry principles, respectively. The solubility of the powder in water as a functi...

  10. Oxidation of magnetite in aerated aqueous media

    International Nuclear Information System (INIS)

    Metastable equilibria involving phases less stable than hematite can be significantly more oxidizing than the calculated equilibrium between well-crystallized hematite and magnetite. In this report, generalized solubility and stability relationships between magnetite and Fe2O3.xH2O phases are derived to describe the metastable equilibria. Experiments with synthetic magnetite powders in aerated aqueous solutions show that crystalline hematite is formed within days at temperatures above 100 C in pure water or solutions containing anions (e.g., Cl-, SO42-, HCO3-) that do not form very strong surface complexes with iron oxides. In the presence of dissolved phosphate or silica, however, the dissolution-precipitation route to hematite is strongly inhibited, and maghemite is a persistent metastable product. Thus, phosphate or silica are expected to delay the approach to magnetite-hematite equilibrium in aerated groundwaters conditioned by magnetite. These findings are presented in the context of nuclear fuel waste disposal. (author). 63 refs., 1 tab., 11 figs

  11. Recent advances in photocatalytic treatment of pollutants in aqueous media.

    Science.gov (United States)

    Reddy, P Anil Kumar; Reddy, P Venkata Laxma; Kwon, Eilhann; Kim, Ki-Hyun; Akter, Tahmina; Kalagara, Sudhakar

    2016-05-01

    Photocatalysis can be an excellent solution for resolving the world's energy and environmental problems. It has a wide range of applications for the decontamination of diverse hazardous pollutants in aqueous media. Technological progress in this research field has been achieved toward the improvement of the solar sensitivity to enhance the efficiency of pollutant decontamination. As a result, various strategies have been introduced to upgrade photocatalytic performance with the modification of prototypical photocatalyst such as doping, dye sensitization, semiconductor coupling, mesoporous supports, single site, and nano-based catalysts. In this review, a brief survey is presented to describe those strategies based on the evaluation made against various pollutants (such as pharmaceuticals, pesticides, heavy metals, detergents, and dyes) in aqueous media. PMID:26915711

  12. Synthesis of CZTS in Aqueous Media Using Microwave Irradiation

    OpenAIRE

    Madiraju, Alekhya Venkata; Taneja, Kshitij; Kumar, Manoj; Keshri, Anup Kumar; Mahajan, Sarang Balkrushna; Seelaboyina, Raghunandan

    2013-01-01

    Copper-Zinc-Tin-Sulfide (CZTS), a promising material for absorber layer application in thin film solar cells, has been synthesized in aqueous media by microwave irradiation technique. Compared to conventional synthesis methods, microwave irradiation is highly efficient, reliable, and less time consuming. The synthesized nanopowders were characterized for particle size by dynamic light scattering (DLS), phase by X-ray diffraction (XRD), and band-gap by UV-Vis-NIR spectroscopy. Various atmosphe...

  13. Dissolution of metal and metal oxide nanoparticles in aqueous media

    International Nuclear Information System (INIS)

    The dissolution of Ag (citrate, gelatin, polyvinylpyrrolidone and chitosan coated), ZnO, CuO and carbon coated Cu nanoparticles (with two nominal sizes each) has been studied in artificial aqueous media, similar in chemistry to environmental waters, for up to 19 days. The dissolved fraction was determined using DGT (Diffusion Gradients in Thin films), dialysis membrane (DM) and ultrafiltration (UF). Relatively small fractions of Ag nanoparticles dissolved, whereas ZnO dissolved nearly completely within few hours. Cu and CuO dissolved as a function of pH. Using DGT, less dissolved Ag was measured compared to UF and DM, likely due to differences in diffusion of organic complexes. Similar dissolved metal concentrations of ZnO, Cu and CuO nanoparticles were determined using DGT and UF, but lower using DM. The results indicate that there is a need to apply complementary techniques to precisely determine dissolution of nanoparticles in aqueous media. - Highlights: • Three different techniques used simultaneously to measure NPs dissolution. • ZnO-NPs are the most soluble, followed by CuO-NPs, carbon coated Cu-NPs and Ag-NPs. • Dissolution is an important process affecting the fate of nanoparticles. • Complementary techniques are needed to precisely determine dissolution of NPs. - Dissolution of several types of nanoparticles was examined in aqueous media using three complementary techniques

  14. Carbonated aqueous media for quench heat treatment of steels

    Science.gov (United States)

    Nayak, U. Vignesh; Rao, K. M. Pranesh; Pai, M. Ashwin; Prabhu, K. Narayan

    2016-07-01

    Distilled water and polyalkylene glycol (PAG)-based aqueous quenchants of 5 and 10 vol.% with and without carbonation were prepared and used as heat transfer media during immersion quenching. Cooling curves were recorded during quenching of an inconel 600 cylindrical probe instrumented with multiple thermocouples. It was observed that the vapor stage duration was prolonged and the wetting front ascended uniformly for quenching with carbonated media. The cooling data were analyzed by determining the critical cooling parameters and by estimating the spatially dependent probe/quenchant interfacial heat flux transients. The study showed significantly reduced values of heat transfer rate for carbonated quenchants compared to quenchants without carbonation. Further, the reduction was more pronounced in the case of PAG-based carbonated quenchants than carbonated distilled water. The results also showed the dependence of heat transfer characteristics of the carbonated media on polymer concentration. The effect of quench uniformity on the microstructure of the material was assessed.

  15. Microwave-assisted synthesis of bio-active heterocycles in aqueous media

    KAUST Repository

    Polshettiwar, Vivek

    2010-01-01

    Synthesis of bio-active heterocycles and fine chemicals in aqueous media are one of the best solutions for the development of green and sustainable protocols. To illustrate the advantages of aqueous MW chemistry in heterocycle synthesis, in this chapter, various synthetic pathways developed in recent years in aqueous reaction media using microwave irradiation are described.

  16. Teologie en Renaissance

    Directory of Open Access Journals (Sweden)

    J. H. van Wyk

    1990-06-01

    Full Text Available In this article some theological perspectives of the Renaissance period are highlighted and discussed. The conclusion arrived at is that we can hardly speak of a "theology of the Renaissance", and that much of the observations about and criticism of the Renaissance period consist of generalisations. Although the author has reservations concerning Renaissance thought in general, appreciation for certain facets is stated.

  17. Asymmetric Transfer Hydrogenation of ω -Bromo Acetophenones in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    Wang Fei; Liu Hui; Cui Xin; Cun Linfeng; Zhu Jin; Deng Jingen; Jiang Yaozhong

    2004-01-01

    Optical active ω-bromophenylethanols are useful building blocks for synthesis of various pharmaceuticals such as α 1-, β 2-, and β 3- adrenergic receptor agonists, which are always obtained though a biotransformative pathway and using boron reagent with rigorous conditions [1]. To our knowledge, the metal-catalysed transfer hydrogenation is seldom applied in this reaction. Recently we have developed a water-soluble chiral Ru-complex and applied successfully in transfer hydrogenation of ω-bromo acetophenones in aqueous media [2], which can not be performed in homogeneous system with HCOOH/NEt3 as hydrogen donor[3] .In this paper, we will report that asymmetric transfer hydrogenation of ω-bromo acetophenones was successfully performed in aqueous media by employing hydrophobic Rh-amido complex (TsDPEN-Rh) as catalyst and HCOONa as hydrogen donor. Moreover, marked increasing of activity and high enantioselectivity (up to 98%) of ω-bromo acetophenone 1a was found in the presence of different micelles or vesicles. This method was also applied successfully in preparation of the important chiral medicinal intermediates, such as the precursor of salbutamol, 2b and fermoterol, 2c with high enantioselectivity.

  18. Precipitation and Solubility of Calcium Soaps in Basic Aqueous Media.

    Science.gov (United States)

    Beneventi, Davide; Carré, Bruno; Gandini, Alessandro

    2001-05-01

    Measurements of the surface tension of aqueous media containing calcium salts of different fatty acids, whose structure only varied by the number of C=C unsaturations along their aliphatic chains, showed that their solubility increased as a function of this parameter going from near zero for calcium stearate to 4x10(-4) mol l(-1) for the linolenate homologue. The solubility product of the calcium soap corresponding to each tested fatty acid was estimated by using the anionic fatty acids adsorption isotherms in order to obtain the amount of dissolved ionic fatty acid at increasing concentration of calcium ions. These findings are discussed in terms of their serious repercussions on the operations related to flotation deinking in waste paper recycling. Copyright 2001 Academic Press. PMID:11334526

  19. Optical technique for broadband microwave absorption spectroscopy in aqueous media

    International Nuclear Information System (INIS)

    Precise measurements of microwave absorption over a large range of frequencies in aqueous media are difficult to obtain and can result in conflicting results as a consequences of small differences in instrumentation. Traditional methods of microwave spectroscopy that make use of time-domain spectrometers or network analyzer systems provide only indirect measurement of the microwave absorption coefficient because they measure the real and imaginary parts of the dielectric constant, ε' and ε'', separately. The absorption coefficient must then be calculated from ε' and ε'' taking into account the geometry (e.g., of the waveguide and mode) among other factors. It has been shown that direct measurement of the microwave absorption coefficient α is possible using phase fluctuation optical heterodyne spectroscopy. Taking advantage of this hybrid optical-microwave technique the authors report on a broadband spectrometer with demonstrated accurate operation from 3 to 20 GHz

  20. Atmospheric-pressure air microplasma jets in aqueous media for the inactivation of Pseudomonas fluorescens cells

    Science.gov (United States)

    Zhang, Xianhui; Liu, Dongping; Song, Ying; Sun, Yue; Yang, Si-ze

    2013-05-01

    The hollow fiber-based cold air microplasma jet array running at atmospheric pressure has been designed to inactivate Pseudomonas fluorescens (P. fluorescens) cells in vitro in aqueous media. The influences of electrode configurations, air flow rate, and applied voltage on the discharge characteristics of the single microplasma jet operating in aqueous media are presented, and the bactericidal efficiency of the hollow fibers-based and large-volume microplasma jet array is reported. Optical emission spectroscopy is utilized to identify excited species during the antibacterial testing of plasma in solutions. These well-aligned and rather stable air microplasma jets containing a variety of short-lived species, such as OH and O radicals and charged particles, are in direct contact with aqueous media and are very effective in killing P. fluorescens cells in aqueous media. This design shows its potential application for atmospheric pressure air plasma inactivation of bacteria cells in aqueous media.

  1. Atmospheric-pressure air microplasma jets in aqueous media for the inactivation of Pseudomonas fluorescens cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xianhui; Yang, Si-ze [Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Liu, Dongping [Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Song, Ying [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Sun, Yue [School of Physics, Changchun University of Science and Technology, Changchun 130022 (China)

    2013-05-15

    The hollow fiber-based cold air microplasma jet array running at atmospheric pressure has been designed to inactivate Pseudomonas fluorescens (P. fluorescens) cells in vitro in aqueous media. The influences of electrode configurations, air flow rate, and applied voltage on the discharge characteristics of the single microplasma jet operating in aqueous media are presented, and the bactericidal efficiency of the hollow fibers-based and large-volume microplasma jet array is reported. Optical emission spectroscopy is utilized to identify excited species during the antibacterial testing of plasma in solutions. These well-aligned and rather stable air microplasma jets containing a variety of short-lived species, such as OH and O radicals and charged particles, are in direct contact with aqueous media and are very effective in killing P. fluorescens cells in aqueous media. This design shows its potential application for atmospheric pressure air plasma inactivation of bacteria cells in aqueous media.

  2. Activation of Carbonyl-Containing Molecules with Solid Lewis Acids in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Román-Leshkov, Yuriy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Chemical Engineering; Davis, Mark E. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Chemical Engineering

    2011-09-28

    Current interest in reacting carbonyl-containing molecules in aqueous media is primarily due to the growing emphasis on conversion of biomass to fuels and chemicals. Recently, solid Lewis acids have been shown to perform catalytic reactions with carbonyl-containing molecules such as sugars in aqueous media. Here, catalysis mediated by Lewis acids is briefly discussed, Lewis acid solids that perform catalysis in aqueous media are then described, and the review is concluded with a few comments on the outlook for the future.

  3. Sonochemically induced decomposition of energetic materials in aqueous media.

    Science.gov (United States)

    Qadir, Lala R; Osburn-Atkinson, Elizabeth J; Swider-Lyons, Karen E; Cepak, Veronica M; Rolison, Debra R

    2003-03-01

    This study demonstrates that ultrasound rapidly degrades the energetic compounds RDX (cyclo-1,3,5-trinitramine-2,4,6-trimethylene) and ADN (ammonium dinitramide) in aqueous microheterogeneous media. The conditions for effective degradation of these nitramines, as monitored by UV absorption spectroscopy, were determined by varying sonication time, the heterogeneous phase and its suspension density, and the concentration of NaOH. In the presence of 5 mg/ml of aluminum powder and at pH approximately 12 (10 mM NaOH), 74% of the RDX and 86% of the ammonium dinitramide (ADN) in near-saturated solutions decompose within the first 20 min of sonication (20 kHz; 50 W; < or =5 degrees C). Sonication without Al powder and base yields minimal degradation of either RDX and ADN (approximately 5-10%) or the nitrite/nitrate ions that are expected byproducts during RDX and ADN degradation. Sonication at high pH in the presence of dispersed aluminosilicate zeolite, alumina, or titanium dioxide also yields minimal degradation. Preliminary electrochemical studies and product analyses indicate that in situ ultrasonic generation of metallic aluminum and/or aluminum hydride drives reductive denitration of the nitramines. Sonochemical treatment in the presence of a reductant offers an effective and rapid waste remediation option for energetic waste compounds. PMID:12531718

  4. Surface plasmon resonance enhanced upconversion luminescence in aqueous media for TNT selective detection.

    Science.gov (United States)

    Tu, Nina; Wang, Leyu

    2013-07-18

    We present a novel report on a surface plasmon resonance enhanced upconversion luminescence strategy in aqueous media for highly sensitive and selective detection of 2,4,6-trinitrotoluene (TNT). PMID:23739225

  5. Synergism and antagonism in extracting local anesthetics from aqueous media with mixtures of solvents

    Science.gov (United States)

    Sukhanov, P. T.; Chibisova, T. V.; Korenman, Ya. I.

    2014-12-01

    The extraction of local anesthetics from aqueous media with mixtures of solvent is examined and its synergistic and antagonistic effects are determined. Synergism parameters, separation factors, constants for the formation of anesthetic complexes, and solvate numbers are calculated.

  6. The interaction of bentonite and glass with aqueous media

    International Nuclear Information System (INIS)

    It has been demonstrated that Si(OH)4 is an important constituent of bentonite. In bentonites natural state the Si(OH)4 in the bentonite is permeable to the diffusible components of the aqeous medium in contact with it. As a consequence, the pH of the medium is a sensitive function of its ionic strength. Permeability of the Si(OH)4 to salt is lost, however, by pretreatment of the bentonite with dilute acid to protonate fully the Si(OH)4. The pH-producing property of the Si(OH)4 then is associated with its surface properties. The glasses (ABS-39 and ABS-Y Marcoule) studied in this research program also contain hydroxylated oxide as an important constituent. These materials, however, are not observed to exhibit gel-like (three-dimensional) properties prior to or after acid pretreatment. Instead they function always as a surface (two-dimensional) and are impermeable to the diffusible components of the aqueous media that come in contact with them. As a result, the pH of the medium is depentdent on ionic strength only so far as it affects the counter-ion screening efficiency of the charged surface. In both systems, bentonite and glass, the pH of the medium is affected by the presence of CO2. The lowering of medium pH by CO2 dissolution results in the neutralization of Si(OH)4 in the untreated bentonite gel phase or in the surface of the acid pretreated bentonite or glass in contact with the medium. If glass and bentonite are in contact the action of CO2 at their interface results in both systems striving to reach different equilibria. The result is enhanced chemical reactivity at the interface. To minimize such reactivity CO2 must be excluded from the atmosphere in contact with the solid-liquid phases. (author)

  7. A Schumpeterian Renaissance?

    OpenAIRE

    Chris Freeman

    2003-01-01

    In the last few decades of the twentieth century, the attention paid to technical innovation in the economics and management literature and in social science generally has justified some such description as "a Schumpeterian renaissance". This article, in justifying the concept of such a renaissance, distinguishes in particular Schumpeter's work on the clustering of innovations and technological revolutions as a major contribution to contemporary theory. As always during his lifetime, the rele...

  8. The Renaissance Teacher

    DEFF Research Database (Denmark)

    Hansen, Per Skafte

    2002-01-01

    The teacher of the new renaissance engineer must be able to draw on all of his or her possible resources, while inspiring students to do likewise. A somewhat pedestrian tabular method is proposed for analysing what skills and propensities are available or desirable and for managing their balanced...... embedding into the teaching activities. Also, to avoid the pitfall of intimidating students with the apparently massive renaissance-style demands, a method of camouflaging the learning tasks is outlined and briefly illustrated....

  9. Selectivity of colour reactions between elements and organic reagents in organo-aqueous acetic acid media

    International Nuclear Information System (INIS)

    Reasons, responsible for selectivity of photometric reactions in organo-aqueous acetic acid media, have been studied taking aluminium, gallium, and indium reactions as examples. Solution-and paper electrophoresis as well as distribution chromatography were used to examine the state of the elements in various media, including those for most selective determination of aluminium in the presence of gallium and indium. A high selectivity is due to the formation of an electrically neutral species of aluminium. And chloride complexes of gallium and indium in organo-aqueous acetic acid media. Coloured ternary complexes of aluminium with organic reagents and phosphoric acid are formed in the presence of the latter

  10. Social Research On Renaissance Period

    Institute of Scientific and Technical Information of China (English)

    张蕾蕾

    2009-01-01

    The historical period known as the Renaissance spans the fifteenth and siXteenth centuries. ‘Renaissance'means‘re-birth'in French and during this time Europe left behind the mindset of the Midge Ages and created the beginnings of the modern world.This thesis mainly rotates on the background,the main features and significance of Renaissance,especially focuses on the discovery of man and the humanism and the detailed unfolding of the society on several aspect in Renaissance.

  11. The Ionian Renaissance and Alexandria

    DEFF Research Database (Denmark)

    Pedersen, Poul

    2008-01-01

    kulturelle epoke - nu ofte kaldet Den Ioniske Renaissance - ikke kun omfattede arkitekturen, men også filosofi, digtning og kunst, samt at den ioniske Renaissance var en af hovedkilderne for det hellenistiske Alexandrias kunst og kultur. Udforskningen af Den Ioniske Renaissance er således af central...

  12. Aqueous citric acid as green reaction media for the synthesis of octahydroxanthenes

    Directory of Open Access Journals (Sweden)

    Camilo A. Navarro D.

    2013-08-01

    Full Text Available A simple, convenient and environmentally friendly one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthenes by the reaction of dimedone and aromatic aldehydes in aqueous citric acid is described. In this green synthetic protocol promoted by the reaction media, the use of any other catalysts and hazardous organic solvents are avoided, making the work up procedure greener and easier. The isolation of the products, obtained in good yields, is readily performed by filtration and crystallization from ethanol when required and the aqueous acidic media can be easily recycled and reused several times without significant loss of catalytic activity.

  13. Synthesis of iron oxide nanoparticles under oxidizing environment and their stabilization in aqueous and non-aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Maity, D. [Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Agrawal, D.C. [Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India)]. E-mail: agrwald@iitk.ac.in

    2007-01-15

    Synthesis of magnetite (Fe{sub 3}O{sub 4}) nanoparticles under oxidizing environment by precipitation from aqueous media is not straightforward because Fe{sup 2+} gets oxidized to Fe{sup 3+} and thus the ratio of Fe{sup 3+}:Fe{sup 2+}=2:1 is not maintained during the precipitation. A molar ratio of Fe{sup 3+}:Fe{sup 2+} smaller than 2:1 has been used by many to compensate for the oxidation of Fe{sup 2+} during the preparation. In this work, we have prepared iron oxide nanoparticles in air environment by the precipitation technique using initial molar ratios Fe{sup 3+}:Fe{sup 2+}{<=}2:1. The phases of the resulting powders have been determined by several techniques. It is found that the particles consist mainly of maghemite with little or no magnetite phase. The particles have been suspended in non-aqueous and aqueous media by coating the particles with a single layer and a bilayer of oleic acid, respectively. The particle sizes, morphology and the magnetic properties of the particles and the ferrofulids prepared from these particles are reported. The average particle sizes obtained from the TEM micrographs are 14, 10 and 9 nm for the water, kerosene and dodecane-based ferrofluids, respectively, indicating a better dispersion in the non-aqueous media. The specific saturation magnetization ({sigma}{sub s}) value of the oleic-acid-coated particles ({approx}53 emu/g) is found to be lower than that for the uncoated particles ({approx}63 emu/g). Magnetization {sigma}{sub s} of the dodecane-based ferrofluid is found to be 10.1 emu/g for a volume fraction of particles {phi}=0.019. Zero coercivity and zero remanance on the magnetization curves indicate that the particles are superparamagnetic (SPM) in nat0009u.

  14. Chemical forms of mercury, cadmium and zinc in natural aqueous media

    International Nuclear Information System (INIS)

    Literary material on chemical forms of mercury, cadmium and zinc in natural aqueous media (in water, suspended and colloid particles, bottom sediments, biota), their toxicology and biotransformations as well as ways and reasons for absorption and removal through the interfaces of the above phases, is generalized and critically analyzed. It is shown that chemical forms of these and other trace metals are the basis for the understanding of their geochemical cycles and at anthropogenic effects on the ecological equilibrium in natural media

  15. State of Supported Nickel Nanoparticles during Catalysis in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Chase, Zizwe; Kasakov, Stanislav; Shi, Hui; Vjunov, Aleksei; Fulton, John L.; Camaioni, Donald M.; Balasubramanian, Mahalingam; Zhao, Chen; Wang, Yong; Lercher, Johannes A.

    2015-11-09

    The state of Ni supported on HZSM-5 zeolite, silica, and sulfonated carbon was determined during aqueous phase catalysis of phenol hydrodeoxygenation using in situ extended X-ray absorption fine structure spectroscopy (EXAFS). On sulfonated carbon and HZSM-5 supports, the NiO and Ni(OH)2 were readily reduced to Ni(0) under reaction conditions (~35 bar H2 in aqueous phenol solutions containing up to 0.5 wt. % phosphoric acid at 473 K). On the silica support, less than 70% of the Ni was converted to Ni(0) under reaction conditions, which is attributed to the formation of Ni phyllosilicates. Over a broad range of reaction conditions there was no leaching of Ni from the supports. In contrast, rapid leaching of the Ni(II) from HZSM-5 was observed, when 15 wt. % aqueous acetic acid was substituted for the aqueous phenol solution. Once the metallic state of Ni was established there was no leaching in 15 wt. % acetic acid at 473 K and 35 bar H2. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences & Biosciences. The STEM was supported under the Laboratory Directed Research and Development Program: Chemical Imaging Initiative at Pacific Northwest National Laboratory (PNNL), a multi-program national laboratory operated for DOE by Battelle under Contract DE-AC05-76RL01830. STEM was performed at EMSL, a DOE Office of Science user facility sponsored by the Office of Biological and Environmental Research and located at PNNL.

  16. Uranium chemistry in blood and aqueous media. Techniques of studies

    International Nuclear Information System (INIS)

    The object of this report in a first step, is to understand the chemistry of uranium in aqueous phase by specifying the behavior of this element in function of several parameters such PH, concentration of present species, temperature, ionic force. In a second step, investigation techniques are reviewed: X rays diffraction, potentiometric titrations, polarography, spectrophotometry, NMR of 13C, 31P, 17O, capillary electrophoresis, laser detection. The third part brings elements to understand the uranium complexation in blood medium

  17. A soil science renaissance

    NARCIS (Netherlands)

    Hartemink, A.E.

    2008-01-01

    The renaissance was an intellectually-rich period following a period of stasis in the medieval period. Something analogous appears to be currently taking place in soil science where novel approaches to thought are combined with a revival of ideas from the past. Renewed interest in agriculture (food,

  18. The renaissance starts here

    Energy Technology Data Exchange (ETDEWEB)

    Nedderman, John

    1997-01-01

    The Asian Pacific Basin region has the highest rate of growth of anywhere in the world and its need for electricity is staggering. This is leading, noted a senior Korean official speaking at the 10th Pacific Basin Nuclear Conference, to a ``renaissance of nuclear power`` in Asia. Judging by the optimism in evidence at the conference, perhaps it has already started. (Author).

  19. Cyanide detection using a benzimidazole derivative in aqueous media

    Science.gov (United States)

    Li, Jian-Bin; Hu, Jing-Han; Chen, Juan-Juan; Qi, Jing

    2014-12-01

    A novel cyanide selective fluorescent chemosensor S1 based on benzimidazole group and naphthalene group as the fluorescence signal group had been designed and synthesized. The receptor could instantly detect CN- anion over other anions such as F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, SCN- and ClO4- by fluorescence spectroscopy changes in aqueous solution (H2O/DMSO, 8:2, v/v) with specific selectivity and high sensitivity. The fluorescence color of the solution containing sensor S1 induced a remarkable color change from pale blue to mazarine only after the addition of CN- in aqueous solution while other anions did not cause obvious color change. Moreover, further study demonstrates the detection limit on fluorescence response of the sensor to CN- is down to 8.8 × 10-8 M, which is far lower than the WHO guideline of 1.9 × 10-6 M. Test strips based on S1 were fabricated, which could act as a convenient and efficient CN- test kit to detect CN- in pure water for “in-the-field” measurement. Thus, the probe should be potential applications in an aqueous environment for the monitoring of cyanide.

  20. Morphology of protective film formed on steel in aqueous media inhibited with tetrazole

    International Nuclear Information System (INIS)

    Surface topography of low-carbon steel after its exposure in water solution of sodium sulfate containing tetrazole as inhibitor, is studied through the methods of screen-electron (SEM) and atom-power (APM) microscopy. The SEM data prove formation of the adsorption phase protection film on the surface of steel samples by their contact with corrosion aqueous media inhibited with tetrazole

  1. Smart surfaces with switchable superoleophilicity and superoleophobicity in aqueous media: Toward controllable oil/water separation

    KAUST Repository

    Zhang, L.

    2012-02-01

    Advanced materials with surfaces that have controllable oil wettability when submerged in aqueous media have great potential for various underwater applications. Here we have developed smart surfaces on commonly used materials, including non-woven textiles and polyurethane sponges, which are able to switch between superoleophilicity and superoleophobicity in aqueous media. The smart surfaces are obtained by grafting a block copolymer, comprising blocks of pH-responsive poly(2-vinylpyridine) and oleophilic/hydrophobic polydimethylsiloxane (i.e., P2VP-b-PDMS) on these materials. The P2VP block can alter its wettability and its conformation via protonation and deprotonation in response to the pH of the aqueous media, which provides controllable and switchable access of oil by the PDMS block, resulting in the switchable surface oil wettability in the aqueous media. On the other hand, the high flexibility of the PDMS block facilitates the reversible switching of the surface oil wettability. As a proof of concept, we also demonstrate that materials functionalized with our smart surfaces can be used for highly controllable oil/water separation processes.

  2. GREENER AND CONTROLLED SYNTHESIS OF NOBLE NANOSTRUCTURES IN AQUEOUS MEDIA USING MICROWAVE IRRADIATION

    Science.gov (United States)

    Microwave-assisted spontaneous reduction of gold salts is described using sugar solutions such as alpha-D-glucose, sucrose and maltose, etc. The expeditious reactions are conducted in aqueous media using microwave irradiation wherein the reduction occurs within 30 to 60 seconds ...

  3. Sorption of tetracycline antibiotics on hyper-crosslinked polystyrene from aqueous and aqueous-organic media

    Science.gov (United States)

    Udalova, A. Yu.; Dmitrienko, S. G.; Apyari, V. V.

    2015-06-01

    The sorption of tetracycline, oxytetracycline, chlortetracycline, and doxycycline on hyper-cross-linked polystyrene from aqueous and aqueous-organic solutions is studied under static and dynamic conditions in order to extend the range of the sorbents suitable for sorption isolation and the preconcentration of tetracycline antibiotics. Features of tetracycline sorption depending on the acidity of a solution and the nature and concentration of the compounds are explained. It is shown that hyper-crosslinked polystyrene can be used for the group sorption preconcentration of these compounds.

  4. Terahertz characteristics of electrolytes in aqueous Luria-Bertani media

    Science.gov (United States)

    Oh, Seung Jae; Son, Joo-Hiuk; Yoo, Ocki; Lee, Dong-Hee

    2007-10-01

    We measured the optical constants of aqueous biomaterial mixtures with various electrolyte concentrations using terahertz time-domain spectroscopy. The mixtures were divided into water and other electrolyte parts in mass fractions for analysis. The optical constants of the electrolyte, excluding water, were obtained by applying the ideal mixture equation, and the power absorption of the electrolyte was observed to be larger than that of water above 1THz. Data from the measurement were fitted with the modified double Debye model, and the reorientation and hydrogen-bond formation decomposition times were found to decrease as the electrolyte concentration increased.

  5. State of Supported Nanoparticle Ni during Catalysis in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Chase, Zizwe; Vjunov, Aleksei; Fulton, John; Camaioni, Donald; Balasubramanian, Mahalingam; Lercher, Johannes

    2015-11-09

    The state of Ni supported on HZSM-5 zeolite, silica, and sulfonated carbon was studied during aqueous-phase catalysis of phenol hydrodeoxygenation using in situ extended X-ray absorption fine structure spectroscopy. On sulfonated carbon and HZSM-5 supports, NiO and Ni(OH)(2) were readily reduced to Ni-0 under reaction conditions (approximate to 35bar H-2 in aqueous phenol solutions containing up to 0.5wt.% phosphoric acid at 473K). In contrast, Ni supported on SiO2 was not stable in a fully reduced Ni-0 state. Water enables the formation of Ni-II phyllosilicate, which is more stable, that is, difficult to reduce, than either -Ni(OH)(2) or NiO. Leaching of Ni from the supports was not observed over a broad range of reaction conditions. Ni-0 particles on HZSM-5 were stable even in presence of 15wt.% acetic acid at 473K and 35bar H-2.

  6. Theoretical Study on the Photosensitizer Mechanism of Phenalenone in Aqueous and Lipid Media.

    Science.gov (United States)

    Espinoza, César; Trigos, Ángel; Medina, Manuel E

    2016-08-11

    The photosensitizer ability of phenalenone was studied in aqueous and lipid media through the single electron transfer reactions, employing the density functional theory. Although phenalenone is a well-known photosensitizer and is widely used as an (1)O2 reference sensitizer, little is known about the reaction mechanism involved. In this study we carried out a single electron transfer reaction between the basal, excited, oxidized and reduced state of phenalenone with oxygen molecules such as (3)O2 and O2(•-). In aqueous media the photosensitizer capacity of phenalenone was measured through both type I and type II mechanisms. In lipid media the photosensitizer ability of phenalenone was attributed to the type II mechanism. The results indicated that the photosensitizer ability of phenalenone shows a heavy reliance on the media where the reaction occurs whether this is an aqueous or lipid media. Finally, this study supports the idea about that electron transfer reactions can be used to study the photosensitizer ability of molecules. PMID:27428932

  7. The dispersion and aggregation of graphene oxide in aqueous media

    Science.gov (United States)

    Wang, Meng; Niu, Yang; Zhou, Jihan; Wen, Hao; Zhang, Zhenyu; Luo, Da; Gao, Dongliang; Yang, Juan; Liang, Dehai; Li, Yan

    2016-07-01

    Graphene oxide (GO), as a typical two-dimensional material, possesses a range of oxygen-containing groups and shows surfactant and/or polyelectrolyte-like characteristics. Herein, GO sheets with narrow size distribution were prepared by an ultracentrifugation-based process and the aggregation behaviour of GO in pure water and an electrolyte aqueous solution were studied using laser light scattering (LLS). When adding common electrolytes, such as NaCl and MgCl2, into the GO dispersions, aggregation occurs and irreversible coagulation eventually occurs too. However, the GO dispersion can still remain stable when adding excess AlCl3. The zeta potential of the GO dispersion changes from negative to positive after the addition of access AlCl3, indicating that electrostatic repulsion is still responsible for the dispersion of GO, which is in good agreement with the LLS results. This finding on the dispersion of GO may be applied in the solution processing of GO. It also expands the scope of the design and preparation of new GO-based hybrid materials with different functions.Graphene oxide (GO), as a typical two-dimensional material, possesses a range of oxygen-containing groups and shows surfactant and/or polyelectrolyte-like characteristics. Herein, GO sheets with narrow size distribution were prepared by an ultracentrifugation-based process and the aggregation behaviour of GO in pure water and an electrolyte aqueous solution were studied using laser light scattering (LLS). When adding common electrolytes, such as NaCl and MgCl2, into the GO dispersions, aggregation occurs and irreversible coagulation eventually occurs too. However, the GO dispersion can still remain stable when adding excess AlCl3. The zeta potential of the GO dispersion changes from negative to positive after the addition of access AlCl3, indicating that electrostatic repulsion is still responsible for the dispersion of GO, which is in good agreement with the LLS results. This finding on the

  8. The dispersion and aggregation of graphene oxide in aqueous media.

    Science.gov (United States)

    Wang, Meng; Niu, Yang; Zhou, Jihan; Wen, Hao; Zhang, Zhenyu; Luo, Da; Gao, Dongliang; Yang, Juan; Liang, Dehai; Li, Yan

    2016-08-14

    Graphene oxide (GO), as a typical two-dimensional material, possesses a range of oxygen-containing groups and shows surfactant and/or polyelectrolyte-like characteristics. Herein, GO sheets with narrow size distribution were prepared by an ultracentrifugation-based process and the aggregation behaviour of GO in pure water and an electrolyte aqueous solution were studied using laser light scattering (LLS). When adding common electrolytes, such as NaCl and MgCl2, into the GO dispersions, aggregation occurs and irreversible coagulation eventually occurs too. However, the GO dispersion can still remain stable when adding excess AlCl3. The zeta potential of the GO dispersion changes from negative to positive after the addition of access AlCl3, indicating that electrostatic repulsion is still responsible for the dispersion of GO, which is in good agreement with the LLS results. This finding on the dispersion of GO may be applied in the solution processing of GO. It also expands the scope of the design and preparation of new GO-based hybrid materials with different functions. PMID:27432559

  9. A new polymeric adsorbent developing for uranium recovering and richment from aqueous media

    International Nuclear Information System (INIS)

    Using adsorbents is thought to be the most effective method for recovering the low concentrations of uranium in the aqueous media because of their fast and selective uptake of uranium, a sufficient adsorption capacity and high physical and chemical stability against the media. In this study, a new polymeric adsorbent bearing both hydrophilic groups providing swelling in water and amidoxime groups for chelating with uranyl ions (UO2''2+) has been developed and its adsorptive ability for uranium from aqueous media has been investigated. The polymers obtained by irradiating the solution of polyethylene glycol (PEG) in acrylonitrile (AN) are defined as Interpenetrating Polymer Networks (IPNs) and the adsorbent has been obtained by applying the amidoximation reaction to the IPNs with a conversion of % 60 approximately. Kinetics of the conversion reaction of nitrile (CN) group to amidoxime (HONCNH2) group has been studied by reacting with hydroxylamine (NH2OH) solution at a molar ratio of NH2OH/CN=1.25 in aqueous media at different temperatures, 30,40,50''0C, for 3-4 days. The degree of amidoximation was determined by UO2''2+ ion adsorption and FTIR spectrometer and the UO2''2+ ion adsorption values were found by both UV and gamma spectrometry and also by gravimetry. It was found that the polymeric adsorbent has a very high adsorption ability for uranium (∼ 540 mg U/g IPN/day)

  10. Proton Adsorption Selectivity of Zeolites in Aqueous Media: Effect of Si/Al Ratio of Zeolites

    OpenAIRE

    Moses Wazingwa Munthali; Mohammed Abdalla Elsheikh; Erni Johan; Naoto Matsue

    2014-01-01

    In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+) system. Although each zeolite has a constant amount of negative charge, the amount of Na+ adsorptio...

  11. An Electrochemical Investigation of the Redox Properties of Murexide in Aqueous and Non-Aqueous Media

    Directory of Open Access Journals (Sweden)

    Hossnia S. Mohran

    2009-01-01

    Full Text Available Knowledge of solvent effects on the redox properties of Murexide (Mu is important for understanding its role as an electron acceptor in analytical and inorganic chemistry. In the present study, an investigation of the electrochemical behavior of the compound by both Cyclic Voltammetry (CV and Electrochemical Impedance Spectroscopy (EIS in both aqueous and non-aqueous solutions was undertaken. It is suggested that, the reaction mechanism proceeds according to an Erev CE-rev-route. This reaction mechanism is confirmed by the CV behavior for barbituric acid, which is essentially represent a main part of murexide, under the same conditions. In DMSO, the one-electron reduction potential peak of murexide was found to shift positively by 223 mV to the value of the corresponding wave obtained in DMF under the same conditions. The shift is most readily explained by the presence of murexide aggregates in DMF. The one-electron oxidation potential position is relatively unaffected by aggregation. The data has also revealed that murexide decomposes in the level of radical anion at the N = C bond into two approximately equal units. In aqueous sodium perchlorate (NaClO4 solutions, it is suggested that the decomposion of murexide is relatively slow, leading to nearly a reversible 1e-transfer process (E-mechanism. In both KNO3 and KCl solutions, the one-electron transfer step of murexide was found to be an adsorption wave. The Electrochemical Impedance (EIS response of murexide is either low-frequency Warburg impedance or a capacitive semicircle behavior at high frequencies, depending on the medium.

  12. Aqueous and hydro-alcoholic media effects on polyols.

    Science.gov (United States)

    Asare-Addo, Kofi; Conway, Barbara R; Hajamohaideen, Mohamed J; Kaialy, Waseem; Nokhodchi, Ali; Larhrib, Hassan

    2013-11-01

    The ingestion of drug products with alcohol can have an adverse effect on drug levels in a patient's blood. The Food and Drug Agency (FDA) issued an alert in 2005 after hydromorphone was withdrawn from the market after clinical trials showed ingestion with alcohol to potentially result in lethal drug peak plasma concentrations. The potential impact of alcohol on extended release (ER) tablet matrices and the need to develop ER matrices robust to alcohol effects has then been of interest. This study investigated the compaction properties of polyols and their effect on drug release. Polyols (erythritol, xylitol, mannitol and maltitol) with increasing hydroxyl groups were used as diluents for HPMC matrices containing theophylline. Release profiles were determined in pH 1.2 and 6.8 dissolution media with hydro-alcoholic concentrations of 5-40%. Increases in the polyols' hydroxyl groups brought about an increase in tablet strength and a decrease in the drug release rates. This is likely due to stronger bond formation with increasing hydroxyls. The impact of alcohol on drug release was studied further for maltitol formulations. Maltitol was resilient to the presence of ethanol (5-40% v/v) at pH 1.2 (f2=57-74) but not at pH 6.8 (f2=36-48). Drug release was not different above 5% alcohol concentration at pH 6.8. The results of this in vitro study suggest that ethanol concentrations as high as 40% do not substantially alter the drug release properties of theophylline from maltitol matrix tablets. However, care and consideration should be given to the choice of polyol or mixture of polyols in obtaining a desired drug release profile. PMID:23777788

  13. Colour reactions of aluminium, titanium and other elements in organo-aqueous media containing acetic acid

    International Nuclear Information System (INIS)

    Colour reactions of titanium, aluminium, gallium, and indium in water-organic media, which also contain organic acids (acetic, formic, or their mixtures with acetone and propanol) are considered with the aim of using them in photometric methods for determining these elements. The reactants used were 2.7-bisazosubstituted components of chromotropic acid. It was established that the rate of development of colouring, the contrast and selectivity increase in water-organic media as compared with aqueous solutions. A favourable effect of acetic acid on the development of colour reactions is noted

  14. Preparation of polyynes by laser ablation of graphite in aqueous media

    International Nuclear Information System (INIS)

    Polyynes were prepared by liquid-phase laser ablation of a graphite target at 1064 nm and identified by analyzing UV absorption spectra in deionized water and various aqueous solutions. We observed that major UV absorption peaks coincide with the electronic transitions corresponding to linear hydrogen-capped polyynes (CnH2: n = 6, 8, 10). The peak intensities increased when polyynes were produced by irradiating the target immersed in acidic media, while those were relatively weak in basic media. This leads us to conclude that OH- or H+ ions play a certain role in the formation of polyynes.

  15. Aqueous citric acid as green reaction media for the synthesis of octahydroxanthenes

    OpenAIRE

    Camilo A. Navarro D.; Cesar A. Sierra; Cristian Ochoa-Puentes

    2013-01-01

    A simple, convenient and environmentally friendly one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthenes by the reaction of dimedone and aromatic aldehydes in aqueous citric acid is described. In this green synthetic protocol promoted by the reaction media, the use of any other catalysts and hazardous organic solvents are avoided, making the work up procedure greener and easier. The isolation of the products, obtained in good yields, is readily performed by filtration and crystal...

  16. Asymmetrical Self-assembly From Fluorinated and Sulfonated Block Copolymers in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun [ORNL; Hong, Kunlun [ORNL; Baskaran, Durairaj [University of Tennessee, Knoxville (UTK); Goswami, Monojoy [ORNL; Sumpter, Bobby G [ORNL; Mays, Jimmy [ORNL

    2011-01-01

    Block copolymers of fluorinated isoprene and partially sulfonated styrene form novel tapered rods and ribbon-like micelles in aqueous media due to a distribution of sulfonation sites and a large Flory-Huggins interaction parameter. A combination of microscopy, light scattering, and simulation demonstrates the presence of these unique nanostructures. This study sheds light on the micellization behavior of amphiphilic block polymers by revealing a new mechanism of self-assembly.

  17. Specific fluorescent sensing of aluminium using naphthalene benzimidazole derivative in aqueous media

    Science.gov (United States)

    Velmurugan, K.; Mathankumar, S.; Santoshkumar, S.; Amudha, S.; Nandhakumar, R.

    2015-03-01

    Naphthalene benzimidazole conjugate bearing a hydroxyl group was synthesized. Its binding properties towards various metal ions were examined and it showed a high selectivity and sensitivity towards Al3+ ions in aqueous media. The recognition processes follows a photo induced electron transfer (PET) mechanism assisted with the restricted intramolecular C-C single bond rotation and are scarcely influenced by other coexisting metal ions. In addition, determination of Al3+ in a variety of sewage water samples was also determined.

  18. Organic-inorganic hybrid materials for boron removal from aqueous media

    OpenAIRE

    SANFELIU CANO, CRISTINA

    2016-01-01

    [EN] The present PhD thesis is centred in the design (using concepts of supramolecular chemistry), synthesis and characterization of different hybrid organic-inorganic materials for boron removal from aqueous media. The interaction between boron and organic groups, polyols, used in the development of these new adsorbents is also studied. In the first part of the thesis it is presented a brief review of supramolecular chemistry concepts, chemistry of boron and also the main methods for bor...

  19. Mass-spectrometric determination of trace elements in aqueous media without preconcentration

    Energy Technology Data Exchange (ETDEWEB)

    Foss, G. O.

    1981-10-01

    Feasibility of using a low pressure glow discharge as an ion source for the mass spectrometric determination of trace elements in aqueous media was investigated. A cryogenically cooled hollow cathode ion source was developed to analyze aqueous samples without external preconcentration. Aqueous solutions containing seventy elements were analyzed and the detection limits, sensitivity factors, and linear regression correlation coefficients were determined. A standard test solution of trace elements in water was analyzed and the concentrations of trace elements were calculated using the sensitivity factors determined previously. The results compared favorably within the error limits predicted by the semiquantitative survey methods used. Tap water and natural lake water samples were examined and minimal interference effects due to organic compounds and biological compounds were noted. A research ion optical system (RIOS) was developed as a flexible mass analyzer for the development of new ion sources. The RIOS is a double focussing mass analyzer designed utilizing the Mattauch-Herzog geometry with externally adjustable slit assemblies.

  20. Monodisperse Cylindrical Micelles and Block Comicelles of Controlled Length in Aqueous Media.

    Science.gov (United States)

    Nazemi, Ali; Boott, Charlotte E; Lunn, David J; Gwyther, Jessica; Hayward, Dominic W; Richardson, Robert M; Winnik, Mitchell A; Manners, Ian

    2016-04-01

    Cylindrical block copolymer micelles have shown considerable promise in various fields of biomedical research. However, unlike spherical micelles and vesicles, control over their dimensions in biologically relevant solvents has posed a key challenge that potentially limits in depth studies and their optimization for applications. Here, we report the preparation of cylindrical micelles of length in the wide range of 70 nm to 1.10 μm in aqueous media with narrow length distributions (length polydispersities crystallization-driven self-assembly. Successful dispersion of these micelles into aqueous media was achieved by dialysis against deionized water. Furthermore, B-A-B amphiphilic triblock comicelles with PFS-b-poly(2-vinylpyridine) (P2VP) as hydrophobic "B" blocks and hydrophilic PFS-b-(PEO-g-TEG) "A" segments were prepared and their hierarchical self-assembly in aqueous media studied. It was found that superstructures formed are dependent on the length of the hydrophobic blocks. Quaternization of P2VP was shown to cause the disassembly of the superstructures, resulting in the first examples of water-soluble cylindrical multiblock comicelles. We also demonstrate the ability of the triblock comicelles with quaternized terminal segments to complex DNA and, thus, to potentially function as gene vectors. PMID:27049840

  1. Effect of passivation on the sensitivity and stability of pentacene transistor sensors in aqueous media

    KAUST Repository

    Khan, Hadayat Ullah

    2011-06-01

    Charge-detecting biosensors have recently become the focal point of biosensor research, especially research onto organic thin-film transistors (OTFTs), which combine compactness, a low cost, and fast and label-free detection to realize simple and stable in vivo diagnostic systems. We fabricated organic pentacene-based bottom-contact thin-film transistors with an ultra-thin insulating layer of a cyclized perfluoro polymer called CYTOP (Asahi Glass Co., Tokyo, Japan) on SiO2 for operation in aqueous media. The stability and sensitivity of these transistor sensors were examined in aqueous buffer media with solutions of variable pH levels after the passivation of perfluoro polymers with thicknesses ranging from 50 to 300nm. These transistor sensors were further modified with an ultra-thin film (5nm) functional layer for selective BSA/antiBSA detection in aqueous buffer media, demonstrating a detection capability as low as 500nM of concentrated antiBSA. The dissociation constant from the antiBSA detection results was 2.1×10-6M. Thus, this study represents a significant step forward in the development of organic electronics for a disposable and versatile chemical and bio-sensing platform. © 2011 Elsevier B.V.

  2. New chemistry of the uranyl ion in non aqueous media

    International Nuclear Information System (INIS)

    precipitation of insoluble MX salt (TlI in pyridine for example), reactions give mononuclear species like [UO2(py)5][I]. Once again, the results presented here highlight the advantage of handling uranyl(VI) compounds in strictly anhydrous and deoxygenated media and further demonstrate that uranyl chemistry will witness novel developments under such experimental conditions. (author)

  3. Renaissance of the Web

    Science.gov (United States)

    McCarty, M.

    2009-09-01

    The renaissance of the web has driven development of many new technologies that have forever changed the way we write software. The resulting tools have been applied to both solve problems and creat new ones in a wide range of domains ranging from monitor and control user interfaces to information distribution. This discussion covers which of and how these technologies are being used in the astronomical computing community. Topics include JavaScript, Cascading Style Sheets, HTML, XML, JSON, RSS, iCalendar, Java, PHP, Python, Ruby on Rails, database technologies, and web frameworks/design patterns.

  4. Aqueous media treatment and decontamination of hazardous chemical and biological substances by contact plasma

    International Nuclear Information System (INIS)

    Usage of non-equilibrium contact plasma for processes of decontamination and neutralization in conditions of manifestation of chemical, biological and radiation terrorism takes on special significance due to portability of equipment and its mobility in places where toxic liquid media hazardous for people's health are located. Processes of decontamination of aqueous media, seminated with pathogenic microorganisms and viruses, treatment of water containing toxic heavy metals, cyanides, surface-active substances, and heavy radioactive elements, are investigated. Examples of activation processes in infected water and toxic aqueous solutions present convincing evidence of the way, how new quality technological approach for achievement of high enough degree of the said media treatment is used in each specific case. Among new properties of water activated as a result of action of non-equilibrium contact plasma, it is necessary to mention presence of cluster structure, confirmed by well-known spectral and physical-chemical methods, presence of peroxide compounds, active particles and radicals. Anti-microbial activity which is displayed under action of plasma in aqueous media (chemically pure water, drinking water, aqueous solutions of sodium chloride, potassium iodide, as well as other inorganic compounds) towards wide range of pathogenic and conventionally pathogenic microorganisms allows use them as reliable, accessible and low-cost preparations for increasing the degree of safety of food products. Combination of such processes with known methods of filtration and ultra-filtration gives an efficient and available complex capable of withstanding any threats, which may arise for population and living organisms. Present-day level of machine-building, electrical engineering, and electronics allows predict creation of industrial plasma installations, adapted to conditions of various terrorist threats, with minimized power consumption and optimized technological parameters

  5. Composition and stability of a molybdenum-arsenic complex in aqueous-organic media

    Energy Technology Data Exchange (ETDEWEB)

    Kolli, N.Ya.; Morosanova, S.A.; Torshina, N.L.

    1986-11-01

    The process of complexation in the arsenic(V)-molybdenum(VI)-H/sub 3/O/sup +/-organic-solvent system has been studied. The results obtained by the mole ratio method, the method of modified isomolar series, and Bjerrum's method make it possible to assert that a molybdenum-arsenic complex of the 12 series forms in water-ethanol, water-dimethylformamide, and water-acetone media and that its apparent stability constants are higher than in an aqueous solution, being equal to 5.8 x 10/sup 6/, 3.9 x 10/sup 6/, and 2.5 x 10/sup 6/, respectively. The increase in the intensity of the absorption of the molybdenum-arsenic complex formed in the UV region and the decrease in the excess concentration of molybdate ions are attributed to the stabilization of the structure of the aqueous-organic solution formed. The 2,4,6-trimethylpyridinium molybdoarsenate has been isolated in its solid form. The fit between the IR spectrum of the compound obtained and the spectrum of sodium 12-molybdoarsenate described in the literature confirms the presence of a molybdenum-arsenic complex of the 12 series in aqueous-organic media studies.

  6. Proton Adsorption Selectivity of Zeolites in Aqueous Media: Effect of Si/Al Ratio of Zeolites

    Directory of Open Access Journals (Sweden)

    Moses Wazingwa Munthali

    2014-12-01

    Full Text Available In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+ system. Although each zeolite has a constant amount of negative charge, the amount of Na+ adsorption of each zeolite decreased drastically at low pH−pNa values, where pH−pNa is equal to log{(Na+/(H+}. By using the plot of the amount of Na+ adsorption versus pH−pNa, an index of the H+ selectivity, which is similar to the pKa of acids, of each zeolite was estimated, and the index tended to increase with decreasing Si/Al ratio of zeolites. These indicate that zeolites with lower Si/Al and higher negative charge density have higher H+ adsorption selectivity, and in fact, such a zeolite species (4A and X adsorbed considerable amount of H+ even at weakly alkaline pH region. The adsorption of H+ results in the decrease of cation adsorption ability, and may lead to the dissolution of zeolites in aqueous media.

  7. Multicatalytic colloids with highly scalable, adjustable, and stable functionalities in organic and aqueous media

    Science.gov (United States)

    Kim, Donghee; Cheong, Sanghyuk; Ahn, Yun Gyong; Ryu, Sook Won; Kim, Jai-Kyeong; Cho, Jinhan

    2016-03-01

    Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent media. Here, we report on layer-by-layer (LbL) assembled multicatalysts with high catalytic performance, showing high dispersion and recycling stability in organic and aqueous media. The remarkable advantages of our approach are as follows. (i) Various metal or metal oxide NPs with desired catalytic performance can be easily incorporated into multilayered shells, forming densely packed arrays that allow one colloid to be used as a multicatalyst with highly integrated and controllable catalytic properties. (ii) Additionally, the dispersion stability of catalytic colloids in a desired solvent can be determined by the type of ultrathin outermost layer coating each colloid. (iii) Lastly, the covalent bonding between inorganic NPs and dendrimers within multilayer shells enhances the recycling stability of multicatalytic colloids. The resulting core-shell colloids including OA-Fe3O4 NPs, TOABr-Pd NPs, and OA-TiO2 NPs exhibited excellent performance in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and photocatalysis in aqueous media and in the Sonogashira coupling reaction (99% yield) in organic media. Given that the catalytic properties of recyclable colloids reported to date have entirely depended on the functionality of a single catalytic NP layer deposited onto colloids in selective solvent media, our approach provides a basis for the design and exploitation of high-performance recyclable colloids with integrated multicatalytic properties and high dispersion stability in a variety of solvents.Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent

  8. Multicatalytic colloids with highly scalable, adjustable, and stable functionalities in organic and aqueous media.

    Science.gov (United States)

    Kim, Donghee; Cheong, Sanghyuk; Ahn, Yun Gyong; Ryu, Sook Won; Kim, Jai-Kyeong; Cho, Jinhan

    2016-03-24

    Despite a large number of developments of noble metal (or metal oxide) NP-based catalysts, it has been a great challenge to prepare high-performance recyclable catalysts with integrated functionalities that can be used in various solvent media. Here, we report on layer-by-layer (LbL) assembled multicatalysts with high catalytic performance, showing high dispersion and recycling stability in organic and aqueous media. The remarkable advantages of our approach are as follows. (i) Various metal or metal oxide NPs with desired catalytic performance can be easily incorporated into multilayered shells, forming densely packed arrays that allow one colloid to be used as a multicatalyst with highly integrated and controllable catalytic properties. (ii) Additionally, the dispersion stability of catalytic colloids in a desired solvent can be determined by the type of ultrathin outermost layer coating each colloid. (iii) Lastly, the covalent bonding between inorganic NPs and dendrimers within multilayer shells enhances the recycling stability of multicatalytic colloids. The resulting core-shell colloids including OA-Fe3O4 NPs, TOABr-Pd NPs, and OA-TiO2 NPs exhibited excellent performance in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and photocatalysis in aqueous media and in the Sonogashira coupling reaction (99% yield) in organic media. Given that the catalytic properties of recyclable colloids reported to date have entirely depended on the functionality of a single catalytic NP layer deposited onto colloids in selective solvent media, our approach provides a basis for the design and exploitation of high-performance recyclable colloids with integrated multicatalytic properties and high dispersion stability in a variety of solvents. PMID:26524289

  9. Some aspects of synergistic extraction of actinides and lanthanides from mixed aqueous-organic media

    International Nuclear Information System (INIS)

    Various aspects of the synergistic extraction and separation of actinides and lanthanides from mixed aqueous-organic solutions (polar media) have been reviewed. Notable recent developments as well as its current status in solvent extraction systems where the aqueous acidic phase contains an organic solvent which is completely miscible with water, are presented briefly. In general, extraction increases in the presence of an organic component. The less polar the additive, the higher is the tendency to form neutral metal complexes which ultimately brings about an increase in the extraction. In a polar media, synergism has mostly been observed, though antagonism is not uncommon. An attempt has been made to classify the factors that play an important role in polar phase extractions. Also, their influence particularly on the extractability of actinides and lanthanides is discussed. The discussion is limited to the factors affecting the extraction equilibria, effect of dielectric constant of the polar medium, solvation of the extracting agent and to the composition and stability of the metal complex in the organic phase. Hydroxyl (OHsup(-)) bearing organic additives, e.g. alcohols, and solvents not containing the hydroxyl group such as acetone, dimethylsulphoxide, tetrahydrofuran, amides and acetonitrile etc. are the two major classes of organic additives considered in these studies. Generally, synergistic effect in extraction of the ion-association (TBP, TOPO, sulphoxides etc.) or anion exchange (amines etc.) type is relatively more pronounced compared to other extractions. A tabular summary concerning extraction of actinides and lanthanides from polar media is appended for ready reference. (author)

  10. Extraction of lithium ion from alkaline aqueous media by a liquid surfactant membrane

    International Nuclear Information System (INIS)

    Extraction of lithium ion from aqueous alkaline media by a liquid surfactant membrane was performed using a mixture of LIX54 and TOPO as the extractant. Stripping of lithium from the kerosene solution to the acid solution was suppressed with increasing content of polyamine (ECA) surfactant. The extraction rate of lithium by the liquid membrane could be interpreted taking account of an interfacial resistance due to ECA. It was confirmed that swelling of the (W/O) emulsion drops by water permeation through the liquid membrane is evaluated in terms of a change in osmotic pressure gradient between the external and internal aqueous phases during the lithium extraction. In the present operation, the extraction ratio of Li+ from the external feed and the uptake into the internal phase reached as high as 95%. (author)

  11. Capillary electrophoresis separation of vinpocetine and related compounds: prediction of electrophoretic mobilities in partly aqueous media.

    Science.gov (United States)

    Mazák, K; Szakács, Z; Nemes, A; Noszál, B

    2000-07-01

    Offord's equation, a relationship between electrophoretic mobility and charge, size and shape of peptides, has been extended to quantitate the electrophoretic mobility of vinca alkaloids. Partly aqueous protonation constants and the derived theoretical mobilities have been proven to be able to predict experimental electrophoretic mobilities. In practice, seven vincamine derivatives of very low water-solubility were separated by capillary electrophoresis. Buffer total concentration, apparent pH and methanol content, the three most important parameters of the running buffer, were used in triangular resolution mapping to characterize separation. Even though electrophoresis is well known to slow down in partly aqueous media, under our optimized circumstances a baseline separation was achieved within 8 min in each case. PMID:10939454

  12. Kinetics of oxidation of nickel(II) aza macrocycles by peroxydisulphate in aqueous media

    Indian Academy of Sciences (India)

    J Lalitham; V R Vijayaraghavan

    2000-10-01

    The kinetics of the oxidation of nickel (II) hexaaza and nickel (II) pentaaza macrocycles by the peroxydisulphate anion, S2O8 2-, were studied in aqueous media. Effect of H on reaction rate was also studied. The rate increases with increase of S2OO8 2- concentration. Rates are almost independent of acid between H 4 and 2, giving overall a relatively simple second-order rate law followed by oxidation within the ion pair solvent shell. Using rate = +1/2 d[Ni(L)3+]/dt = k[Ni(L)2+][S2O8 2-], oxidation rate constants were determined.

  13. The study of CdSe colloidal quantum dots synthesized in aqueous and organic media

    International Nuclear Information System (INIS)

    The samples of CdSe colloidal quantum dots (CQDs) synthesized in aqueous and organic media are studied. The possibility of luminescence peak position control depending on nanoparticle growth process is demonstrated. The samples synthesized in organic medium revealed the luminescence color variation effect with nanoparticle growth. The relation of this effect with processes of nucleation and defect formation in nanoparticles is considered. The CQDs of CdSe coated with CdS shell are fabricated. The use of inorganic shell can provide a double increase of the luminescence quantum yield

  14. Baylis-Hillman Reaction Involving Substituted Cyclic Enones in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    LUO San-Zhong; WANG Peng G.; CHENG Jin-Pei

    2003-01-01

    @@ β-Substituted enones have been considered less reactive in Baylis-Hillman reaction. The reaction of cyclicenones is sluggish or does not occur at all under traditional conditions. [1] Therefore, substituted cyclic enones havebeen less explored in Baylis-Hillman reaction due to the extremely low reactivity. In this communication, we reported Baylis-Hillman reaction of substituted cyclic enones using our previously developed conditions with imidazole as catalyst. The reaction proceeded smoothly in aqueous media affording the desired product with good yields and moderate diastereoselectivity.

  15. Suzuki-Miyaura cross-coupling reactions in aqueous media: Green and sustainable syntheses of biaryls

    KAUST Repository

    Polshettiwar, Vivek

    2010-02-28

    Carbon-carbon cross-coupling reactions are among the most important processes in organic chemistry, and Suzuki-Miyaura reactions are among the most widely used protocols for the formation of carbon-carbon bonds. These reactions are generally catalyzed by soluble palladium complexes with various ligands. However, the use of toxic organic solvents remains a scientific challenge and an aspect of economical and ecological relevance. This Review will summarize various recently developed significant methods by which the Suzuki-Miyaura coupling was conducted in aqueous media, and analyzes if they are "real green" protocols. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Dissolution of sphene and sphene glass-ceramics in aqueous media

    International Nuclear Information System (INIS)

    Sphene (CaTiSiO/sub 5/) and sphene-based glass-ceramics were leached in different aqueous media over a wide range of pH values at 900C. Proton-Ca/sup 2+/ exchange and silica dissolution were the dominant leaching mechanisms for sphene in neutral and HCI solutions. In citric acid solutions, sphene dissolution was nearly congruent. The dissolution rate based on calcium extraction varied approximately as [H/sup +/]/sup 0.2/ in the pH range of 1 to 8.5. Anatase surface-layer formation in acid and neutral media did not greatly inhibit leaching. Alkaline (NaOH) or chloride solutions did not significantly enhance sphene dissolution relative to deionized water

  17. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    International Nuclear Information System (INIS)

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pKa values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase

  18. Preparation and Application of Titanate Nanotubes on Dye Degradation from Aqueous Media by UV Irradiation

    Directory of Open Access Journals (Sweden)

    Rui Liu

    2015-01-01

    Full Text Available Titanate nanotubes were synthesized by a hydrothermal method using commercial TiO2 powder and then used as a photocatalyst. The titanate nanotubes were synthesized by varying the hydrothermal temperature from 110°C to 180°C. The morphological changes and phase transformation of the TiO2 nanotubes were analyzed by X-ray diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The particles’ scattering behavior was investigated by Raman studies, and the surface area of the nanotubes was determined by a Brunauer, Emmett, and Teller (BET analysis. Comparative studies show that the surface area of nanotubes increases with increasing temperature up to 130°C. The catalytic behavior of the synthesized nanotubes was also studied. The as-prepared titanate nanotubes were applied to methylene blue (MB, an organic dye degradation in aqueous media by UV irradiation. Approximately 99% of the dye was removed from the aqueous media using 2 g/L titanate nanotube when the initial dye concentration was 9 mg/L. The total irradiation time was 2 h.

  19. Lifetime and dissolution kinetics of zinc oxide nanoparticles in aqueous media.

    Science.gov (United States)

    Wang, Ning; Tong, Tiezheng; Xie, Minwei; Gaillard, Jean-François

    2016-08-12

    We have assessed the persistence and lifetime of ZnO nanoparticles (ZnO-NPs) by performing dissolution experiments in three different aqueous media. These experiments were performed at ZnO-NP concentration levels close to the solubility of zincite (∼8 μM or 650 μg l(-1) of ZnO)-a concentration that is orders of magnitude higher than current estimated relevant environmental concentrations. The kinetics were followed by voltammetry, while maintaining the pH at about 7.5 using a CO2/N2 gas mixture to remove di-oxygen interference. Our results show that, under these conditions, ZnO-NPs readily dissolve with a lifetime expectancy that does not exceed 90 min. Water chemistry, especially the presence of dissolved organic matter (DOM), plays an important role in ZnO-NP dissolution. Dissolution rates significantly increase in the presence of strong chelating agents, EDTA and L-cysteine, while the addition of polymeric DOM, such as sodium alginate, has the opposite effect. Our results suggest that ZnO-NPs are unlikely to persist in natural aqueous media and that the toxicity should be primarily related to the released Zn(2+) ions rather than effects commonly associated to the presence of nanoparticles. PMID:27348603

  20. PolyMUMPs MEMS device to measure mechanical stiffness of single cells in aqueous media

    International Nuclear Information System (INIS)

    A method of experimentally determining the mechanical stiffness of single cells by using differential displacement measurements in a two stage spring system is presented. The spring system consists of a known MEMS reference spring and an unknown cellular stiffness: the ratio of displacements is related to the ratio of stiffness. A polyMUMPs implementation for aqueous media is presented and displacement measurements made from optical microphotographs using a FFT based displacement method with a repeatability of ∼20 nm. The approach was first validated on a MEMS two stage spring system of known stiffness. The measured stiffness ratios of control structures (i) MEMS spring systems and (ii) polystyrene microspheres were found to agree with theoretical values. Mechanical tests were then performed on Saccharomyces cerevisiae (Baker’s yeast) in aqueous media. Cells were placed (using a micropipette) inside MEMS measuring structures and compressed between two jaws using an electrostatic actuator and displacements measured. Tested cells showed stiffness values between 5.4 and 8.4 N m−1 with an uncertainty of 11%. In addition, non-viable cells were tested by exposing viable cells to methanol. The resultant mean cell stiffness dropped by factor of 3 × and an explicit discrimination between viable and non-viable cells based on mechanical stiffness was seen. (paper)

  1. Lifetime and dissolution kinetics of zinc oxide nanoparticles in aqueous media

    Science.gov (United States)

    Wang, Ning; Tong, Tiezheng; Xie, Minwei; Gaillard, Jean-François

    2016-08-01

    We have assessed the persistence and lifetime of ZnO nanoparticles (ZnO-NPs) by performing dissolution experiments in three different aqueous media. These experiments were performed at ZnO-NP concentration levels close to the solubility of zincite (∼8 μM or 650 μg l‑1 of ZnO)—a concentration that is orders of magnitude higher than current estimated relevant environmental concentrations. The kinetics were followed by voltammetry, while maintaining the pH at about 7.5 using a CO2/N2 gas mixture to remove di-oxygen interference. Our results show that, under these conditions, ZnO-NPs readily dissolve with a lifetime expectancy that does not exceed 90 min. Water chemistry, especially the presence of dissolved organic matter (DOM), plays an important role in ZnO-NP dissolution. Dissolution rates significantly increase in the presence of strong chelating agents, EDTA and L-cysteine, while the addition of polymeric DOM, such as sodium alginate, has the opposite effect. Our results suggest that ZnO-NPs are unlikely to persist in natural aqueous media and that the toxicity should be primarily related to the released Zn2+ ions rather than effects commonly associated to the presence of nanoparticles.

  2. The spironolactone renaissance.

    Science.gov (United States)

    Doggrell, S A; Brown, L

    2001-05-01

    Until recently, spironolactone was considered only as an antagonist at the aldosterone receptors of the epithelial cells of the kidney and was used clinically in the treatment of hyperaldosteronism and, occasionally, as a K(+)-sparing diuretic. The spironolactone renaissance started with the experimental finding that spironolactone reversed aldosterone-induced cardiac fibrosis by a cardiac action. Experimentally, spironolactone also has direct effects on blood vessels. Spironolactone reduces vascular fibrosis and injury, inhibits angiogenesis, reduces vascular tone and reduces portal hypertension. The rationale for the Randomized Aldactone Evaluation Study (RALES) of spironolactone in heart failure was that 'aldosterone escape' occurred through non-angiotensin II mechanisms. The RALES clinical trial was stopped early when it was shown that there was a 30% reduction in risk of death among the spironolactone patients. In RALES, spironolactone also reduced hospitalisation for worsening heart failure and improved the symptoms of heart failure. Other recent clinical trials have shown that spironolactone reduces cardiac and vascular collagen turnover, improves heart variability, reduces ventricular arrhythmias, improves endothelial dysfunction and dilates blood vessels in human heart failure and these effects probably all contribute to the increased survival in heart failure. Spironolactone may also be useful in the treatment of left ventricular hypertrophy, portal hypertension and cirrhosis. There have also been some recent small clinical trials of spironolactone as an anti-androgen showing potential in acne, hirsutism and precocious puberty. PMID:11322868

  3. Nuclear Energy's Renaissance

    Science.gov (United States)

    Kadak, Andrew C.

    2006-10-01

    Nuclear energy is about to enter its renaissance. After almost 30 years of new plant construction dormancy, utilities are seriously preparing for ordering new plants in the next two years. This resurgence in interest is based on improved plant performance, new Nuclear Regulatory Commission licensing processes, significant incentives introduced by Congress in the Energy Policy Act of 2005 to encourage new orders, and new technologies that are competitive, simpler to operate and safer. These new evolutionary light water reactors will pave the way to more advanced high temperature gas reactors such as the pebble bed or prismatic reactors that will provide improved efficiency and safety leading to more process heat applications in oil extraction or hydrogen production. The Next Generation Nuclear Plant (NGNP) also authorized by the Energy Policy act will provide the fundamental technical basis for the future of these technologies. Progress continues on the Yucca Mountain nuclear waste disposal site enabling this expansion. When coupled with the long term strategy of waste minimization through reprocessing and actinide destruction as proposed in the Global Nuclear Energy Partnership, the future of nuclear energy as part of this nation's energy mix appears to be assured.

  4. Mechanism of laser ablation for aqueous media irradiated under confined-stress conditions

    International Nuclear Information System (INIS)

    Pulsed laser ablation of aqueous medium irradiated under conditions of temporal confinement of thermal stress is described. Time-resolved measurements of laser-induced transient stress waves with simultaneous imaging of ablation process by laser-flash photography were performed. Stress transients induced in aqueous solution of K2CrO4 by ablative nanosecond laser pulses at 355 nm were studied by a broad-band lithium niobate acoustic transducer. Recoil momentum upon material ejection was measured from the temporal profiles of the acoustic transducer signal as a function of incident laser fluence. Cavitation bubbles produced in the irradiated volume during the tensile phase of thermoelastic stress were shown to drive material ejection at temperatures substantially below 100 degree C. Experimental data are evident that nanosecond-pulse laser ablation of aqueous media (when temporal stress-confinement conditions are satisfied) include the following two main stages of material ejection: (1) ejection of water microdroplets due to expansion and rupture of subsurface cavitation bubbles; (2) ejection of liquid streams with substantial volume upon collapse of initial crater and large cavitation bubbles in the depth of irradiated volume (after coalescence of smaller bubbles). copyright 1995 American Institute of Physics

  5. Synthesis and characterization of ferrous phosphate (vivianite) and its behavior in aqueous media

    International Nuclear Information System (INIS)

    The synthesis and characterization of materials that can be useful in Environmental Chemistry is very important because their characteristics are exposed and its behavior in chemical phenomena as the sorption in aqueous media is understand to use it in the human being benefit. With the object of using, in a future, the octa hydrated ferrous phosphate (vivianite) as a potential candidate for matrix confinement in contention walls for the storage of radioactive waste of long half life, it was synthesized and it characterized physico chemically and their properties of surface of this compound were evaluated. Presently work was carried out the synthesis and structural characterization of the iron phosphate II by infrared spectroscopy with having Fourier transform, high vacuum scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis, the BET multipoint surface area and Moessbauer spectroscopy; as well as, the determination between aqueous media of the isoelectric point and the density of sites of surface of the compound. The octa hydrated ferrous phosphate was obtained pure. The results indicate that the product corresponds to the prospective mineral, the vivianite. The thermal gravimetric analysis demonstrated that the ferrous phosphate is a stable salt after the lost of water. The isoelectric point is since an important parameter because allows to know the behavior of the surface of the material in aqueous systems, in this case the isoelectric point, of the octa hydrated ferrous phosphate, in distilled water is of pH 4.20 and in solution of potassium nitrate 0.5 M is of pH = 3.75. This indicates that the material has an amphoteric surface depending on the pH. On the other hand, the density of active sites of surface obtained by titrations acid-base is of 20 sites by nm2. (Author)

  6. Stability of melamine-exfoliated graphene in aqueous media: quantum-mechanical insights at the nanoscale.

    Science.gov (United States)

    Rodríguez, Antonio M; Muñoz-García, Ana B; Crescenzi, Orlando; Vázquez, Ester; Pavone, Michele

    2016-08-10

    In recent experiments, melamine (1,3,5-triazine-2,4,6-triamine) has been proposed as an effective exfoliating agent to obtain high quality graphene from graphite. After washing out the melamine in excess, small amounts (ppm) are still needed to stabilize the dispersion of graphene flakes in aqueous media. To understand the origin of this behaviour, we investigated the melamine-graphene-water system and the fundamental interactions that determine its structure and energetics. To disentangle the subtle interplay of hydrogen-bonding and dispersive forces we used state-of-the-art ab initio calculations based on density functional theory. First, we focused on the case of water molecules interacting with melamine-graphene assemblies at different melamine coverages. We found that water-melamine interactions provide the driving force for washing off the melamine from graphene. Then, we addressed the interaction of single and double layers of water molecules with the graphene surface in the presence of an adsorbed melamine molecule. We found that this melamine acts as a non-covalent anchor for keeping a number of water molecules conveniently close to the graphene surface, thus helping its stabilization in aqueous media. Our analysis helps understanding how competing weak forces can lead to a stable graphene water suspension thanks to small amounts of adsorbed melamine. From our results, we derive simple indications on how the water-graphene interfacial properties can be tuned via non-covalent adsorption of small functional molecules with H-bond donor/acceptor groups. These new hints can be helpful to prepare stable graphene dispersions in water and so to unlock graphene potential in aqueous environments. PMID:27452832

  7. A nanofiber functionalized with dithizone by co-electrospinning for lead (II) adsorption from aqueous media

    International Nuclear Information System (INIS)

    Highlights: ► We fabricated a composite electrospun nanofiber as a selective sorbent for lead (II) in PFSPE. ► The composite nanofiber was functionalized with the dithizone by co-electrospinning of the PS solution containing unbonded dithizone. ► The nanofiber was characterized by scanning electron microscope and IR spectra. ► We applied the nanofiber by packing in a cartridge. ► The nanofiber performed well in the absorption of lead (II) and was applied successfully in aqueous samples. - Abstract: An electrospun nanofiber was utilized as a sorbent in packed fiber solid phase extraction (PFSPE) for selective separation and preconcentration of lead (II). The nanofiber had a polystyrene (PS) backbone, which was functionalized with dithizone (DZ) by co-electrospinning of a PS solution containing DZ. The nanofiber exhibited its performance in a cartridge prepared by packing 5 mg of nanofiber. The nanofiber was characterized by a scanning electron microscope and IR spectra. The diameter of the nanofiber was less than 400 nm. After being activated by 2.0 mol L−1 NaOH aqueous solution, the nanofiber quantitatively sorbed lead (II) at pH 8.5, and the metal ion could be desorbed from it by three times of elution with a small volume of 0.1 mol L−1 HNO3 aqueous solution. The breakthrough capacity was 16 μg mg−1. The nanofiber could be used for concentration of lead (II) from water and other aqueous media, such as plasma with stable recovery in a simple and convenient manner.

  8. Fast and ultrafast spectroscopic investigation of tetracycline derivatives in organic and aqueous media.

    Science.gov (United States)

    Carlotti, Benedetta; Fuoco, Domenico; Elisei, Fausto

    2010-12-28

    The photophysical properties of seven tetracycline derivatives (tetracycline, oxytetracycline, demeclocycline, chlortetracycline, doxycycline, minocycline and meclocycline) in organic solvents and aqueous solution were studied using steady-state absorption and fluorescence techniques and transient absorption spectroscopies with nanosecond and femtosecond time resolution. The molecular structure, solvent and pH effects on the optical properties of this class of pharmaceutically interesting compounds were investigated in detail. The investigation furnished a complete description of the nature, the spectral and kinetic properties of the excited states formed upon irradiation. All the tetracycline derivatives exhibited a similar behaviour, and the photophysics of these molecules is different in organic solvents and in aqueous medium, where they exhibit a significant pH dependence. In water, compared to organic solvents, these compounds showed a blue-shifted bathochromic absorption band, a red-shifted emission spectrum, an increased Stokes shift and a decreased fluorescence quantum yield. These findings, together with the overall investigated solvent effect, suggested that in aqueous solvent additional fast and non-radiative deactivation processes, responsible for the large Stokes Shift and for the reduced fluorescence efficiency, are present. In fact, in organic media just two transients were observed during the ultrafast time-resolved investigation: the vibrationally hot S(1) state which was quickly stabilized by solvent reorganization to the relaxed S(1) state. This state showed lifetimes of tens of picoseconds and relaxed by fluorescence and internal conversion. No longer-lived transients were detected. In aqueous solution the excited-state deactivation of tetracyclines was found to be more complicated. Different protonated and tautomeric forms of the S(1) state were detected: a component which showed decay times of tens of picoseconds and a component which was

  9. Graphene oxide as filter media to remove levofloxacin and lead from aqueous solution.

    Science.gov (United States)

    Dong, Shunan; Sun, Yuanyuan; Wu, Jichun; Wu, Benjun; Creamer, Anne Elise; Gao, Bin

    2016-05-01

    There is an increasing need to develop novel and high-efficiency water purification technologies. This work systematically evaluated the potential of using graphene oxide (GO) directly as filter media for the removal of levofloxacin (LEV), an emerging contaminate, and lead (Pb), a heavy metal, from aqueous solution. Batch and fixed-bed experiments were conducted to determine the sorption behaviors of LEV and Pb onto the GO. In the batch system, GO showed strong sorption of the two contaminants with Langmuir maximum adsorption capacities of 256.6 and 227.2 mg g(-1), respectively. The removal of LEV and Pb by GO in fixed-bed columns was high under all tested conditions in both single and mixed solution systems. The removal efficiency of the two contaminants in the GO-sand columns increased with increasing GO content, but decreased with increasing injection flow rate. In the mixed solution system, although LEV and Pb competed for sorption, the GO media still had high removal efficiencies for them. The column experimental data were well described by the Bed Depth Service Time (BDST) model, suggesting the model can be used for the design of GO-sand filters in large-scale applications. Findings from this work demonstrated that GO is a promising nano-adsorbent that can be used as a high-efficiency filter media in water treatment to remove hazardous metal elements and emerging contaminants. PMID:26683821

  10. Synthesis and fluorescence properties of CdSe/CdS nanoparticles in aqueous media

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On the basis of unique structural characteristics of α-cyclodextrin,α-cyclodextrin modified CdSe/CdS nanoparticles have been successfully synthesized in aqueous media.Techniques of AFM,TEM,EDS,FTIR,UV-vis absorbance and photoluminescence spectra were used to characterize the morphology,composition and optical characteristics of the synthesized nanoparticles.The results showed that the as-synthesized nanoparticles were elliptical and composed of several small particles.Their average length and diameter were about 20 nm and 15 nm.CdSe/CdS nanoparticles had single well-crystallized hexagonal structure.Packaged with a shell of CdS on the surface,α-CD/CdSe-CdS nanoparticles exhibited a red shift in the absorption spectrum,intensity growth in the emission spectrum and a substantial increase in Quantum yields.The size distribution could be adjusted by precursor ratios in the presence of α-cyclodextrins.

  11. Thermodynamics and kinetics of adsorption of dyes from aqueous media onto alumina

    International Nuclear Information System (INIS)

    Use of alumina for the removal of industrially important dyes namely, methylene blue, methyl blue, bromophenol blue, malachite green, eriochrome black-T, phenol red and methyl violet from aqueous media at different shaking times, temperatures and pH values has been investigated. The adsorption data was fitted to both the pseudo-first-order and pseudo-second-order kinetic models and calculated values of amount adsorbed at equilibrium (q/sub e/) by pseudo-second-order equations were found to be in good agreement with the experimental values. The negative values of delta H and delta G indicates that the adsorption is exothermic and spontaneous, respectively. The adsorption data was fitted to Freundlich, B.E.T., Dubinin-Radushevich (D-R) and Langmuir isotherms and their corresponding adsorption parameters for each were calculated. The dyes were found to be chemisorbed onto alumina. (author)

  12. pH controlled dispersion and slip casting of Si3N4 in aqueous media

    Indian Academy of Sciences (India)

    R Ramachandra Rao; H N Roopa; T S Kannan

    2001-02-01

    The dispersion characteristics of commercial Si3N4 powder in aqueous media (deionized water) was studied as a function of pH in the range 2–11. The slip was characterized for its dispersion quality by various experimental techniques like particle size analysis, sedimentation phenomena, viscosity and flow behaviour and zeta potential analysis. The optimum dispersion was found to be in the pH region 9–11 wherein the slurry displayed minimum sedimentation height, minimum viscosity, near Newtonian flow behaviour and maximum zeta potential. The slip is highly agglomerated in the pH range 2–8 as manifested by higher sedimentation height, higher viscosity, lower zeta potential and thixotropic non-Newtonian flow behaviour. The 72 wt% (44 vol.%) Si3N4 slips made at pH = 10 resulted in green bodies having 53–59% of theoretical density after casting into plaster molds.

  13. The use of biosorbents for heavy metals removal from aqueous media

    International Nuclear Information System (INIS)

    Biomaterials, which could be adsorbed heavy metals, such bacteria, algae, yeasts, fungi and agricultural waste, is called Biomass. Recently, they are widely used for heavy metal removal from aqueous media, due to their large available quantities, low cost and good performance. The biosorbent, unlike mono functional ion exchange resins, contains variety of functional sites including carboxyl, imidazole, sulphydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl moieties. In this paper, the biosorbents word widely and nationally used for heavy metal removal were reviewed. Their biosorption performance, their pretreatment and modification, aiming to improve their sorption capacity, and regeneration/reuse was introduced and evaluated. The potential application of biosorption and biosorbents was discussed. (author)

  14. Water as a promoter and catalyst for dioxygen electrochemistry in aqueous and organic media.

    Energy Technology Data Exchange (ETDEWEB)

    Staszak-Jirkovsky, Jakub; Subbaraman, Ram; Strmcnik, Dusan; Harrison, Katherine L.; Diesendruck, Charles E.; Assary, Rajeev; Frank, Otakar; Kobr, Lukas; Wiberg, Gustav K.H; Genorio, Bostjan; Connell, Justin G.; Lopes, Pietro P.; Stamenkovic, Vojislav R.; Curtiss, Larry; Moore, Jeffrey S.; Zavadil, Kevin R.; Markovic, Nenad M.

    2015-11-01

    Water and oxygen electrochemistry lies at the heart of interfacial processes controlling energy transformations in fuel cells, electrolyzers, and batteries. Here, by comparing results for the ORR obtained in alkaline aqueous media to those obtained in ultradry organic electrolytes with known amounts of H2O added intentionally, we propose a new rationale in which water itself plays an important role in determining the reaction kinetics. This effect derives from the formation of HOad center dot center dot center dot H2O (aqueous solutions) and LiO2 center dot center dot center dot H2O (organic solvents) complexes that place water in a configurationally favorable position for proton transfer to weakly adsorbed intermediates. We also find that, even at low concentrations (<10 ppm), water acts simultaneously as a promoter and as a catalyst in the production of Li2O2, regenerating itself through a sequence of steps that include the formation and recombination of H+ and OH-. We conclude that, although the binding energy between metal surfaces and oxygen intermediates is an important descriptor in electrocatalysis, understanding the role of water as a proton-donor reactant may explain many anomalous features in electrocatalysis at metal-liquid interfaces.

  15. Self-assembly of light-harvesting crystalline nanosheets in aqueous media.

    Science.gov (United States)

    Shahar, Chen; Baram, Jonathan; Tidhar, Yaron; Weissman, Haim; Cohen, Sidney R; Pinkas, Iddo; Rybtchinski, Boris

    2013-04-23

    A methodology leading to facile self-assembly of crystalline aromatic arrays in dilute aqueous solutions would enable efficient fabrication and processing of organic photonic and electronic materials in water. In particular, soluble 2D crystalline nanosheets may mimic the properties of photoactive thin films and self-assembled monolayers, covering large areas with ordered nanometer-thick material. We designed such solution-phase arrays using hierarchical self-assembly of amphiphilic perylene diimides in aqueous media. The assemblies were characterized by cryogenic transmission electron microscopy (cryo-TEM), revealing crystalline order and 2D morphology (confirmed by AFM studies). The order and morphology are preserved upon drying as evidenced by TEM and AFM. The 2D crystalline-like structures exhibit broadening and red-shifted absorption bands in UV-vis spectra, typical for PDI crystals and liquid crystals. Photophysical studies including femtosecond transient absorption spectroscopy reveal that two of the assemblies are superior light-harvesters due to excellent solar spectrum coverage and fast exciton transfer, in one case showing exciton diffusion comparable to solid-state crystalline systems based on perylene tetracarboxylic dianhidride (PTCDA). PMID:23521176

  16. Silver nanoparticles embedded polymer sorbent for preconcentration of uranium from bio-aggressive aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sadananda [Department of Chemistry, University of Pune, Pune 411 007 (India); Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Pandey, Ashok K., E-mail: ashokk@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Athawale, Anjali A. [Department of Chemistry, University of Pune, Pune 411 007 (India); Subramanian, M. [Bio-organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Seshagiri, T.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Khanna, Pawan K. [Nanoscience Laboratory, Centre for Materials for Electronics Technology, Pune 411 008 (India); Manchanda, Vijay K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2011-02-28

    Adsorptive sorbent for bio-aggressive natural aqueous media like seawater was developed by one pot simultaneous synthesis of silver nanoparticles (Ag nps) and poly(ethylene glycol methacrylate phosphate) (PEGMP) by UV-initiator induced photo-polymerization. The photo-polymerization was carried out by irradiating N,N'-dimethylformamide (DMF) solution containing appropriate amounts of the functional monomer (ethylene glycol methacrylate phosphate), UV initiator ({alpha},{alpha}'-dimethoxy-{alpha}-phenyl acetophenone), and Ag{sup +} ions with 365 nm UV light in a multilamps photoreactor. To increase mechanical strength, nano-composite sorbent (Ag-PEGMP) was also reinforced with thermally bonded non-woven poly(propylene) fibrous sheet. Transmission electron microscopy (TEM) of the nano-composite sorbent showed uniform distribution of spherical Ag nanoparticles with particles size ranging from 3 to 6 nm. The maximum amount of Ag{sup 0} that could be anchored in the form of nanoparticles were 5 {+-} 1 and 10 {+-} 1 wt.% in self-supported PEGMP and poly(propylene) reinforced PEGMP matrices, respectively. Ag-PEGMP sorbent was found to be stable under ambient conditions for a period of six months. Ag-PEGMP composite sorbent did not exhibit growth at all after incubation with pre-grown Escherichia coli cells, and showed non-adherence of this bacteria to the composite. This indicated that composite sorbent has the bio-resistivity due to bacterial repulsion and bactericidal properties of Ag nanoparticles embedded in the PEGMP. Sorption of U(VI) in PEGMP and Ag-PEGMP nano-composite sorbents from well-stirred seawater was studied to explore the possibility of using it for uranium preconcentration from bio-aggressive aqueous streams. The nano-composite sorbent was used to preconcentrate U(VI) from a process aqueous waste stream.

  17. An efficient method for synthesis of phenacyl derivatives under homogeneous phase transfer catalyst condition in aqueous media

    Institute of Scientific and Technical Information of China (English)

    Soheil Sayyahi; Jafar Saghanezhad

    2011-01-01

    In this letter, a mild and efficient procedure for synthesis of phenacyl derivatives under homogenous catalysis in the presence of tetrabutylammonium bromide in aqueous media is described. The nucleophilic substitution reactions were performed under ecofriendly conditions and gave the corresponding products in high yields and short reaction times.

  18. Corrosion inhibitors for carbon steel in neutral aqueous media based on the products of sugar cane processing. 3. Combined inhibitors

    International Nuclear Information System (INIS)

    Combined (mixed) inhibitors of metal corrosion in aqueous media are developed on the fasis of mixtures of 5-nitro furancarboxylic acid salts (nitrofuroat) with inorganic passivators (nitrite, phosphate, tetraborate) or with nitrogen-containing derivatives of furfural (furfurine, furfurylamine). Their efficiency is confirmed by electrochemical and weighing investigations carried outn under lamoratory and industrial conditions

  19. How Hermetic was Renaissance Hermetism?

    NARCIS (Netherlands)

    W.J. Hanegraaff

    2015-01-01

    Based upon key publications by Paul Oskar Kristeller (1938) and especially Frances A. Yates (1964), it has been widely assumed that an important “Hermetic Tradition” emerged during the Renaissance and that Marsilio Ficino’s Latin translation of the Corpus Hermeticum (first ed. 1471) was at its origi

  20. Charcot's hysteria renaissant.

    OpenAIRE

    Critchley, E M; Cantor, H E

    1984-01-01

    The authenticity of Charcot's original descriptions of hysteria has been questioned in the popular media. None the less, it is still possible to encounter florid forms of hysteria in culturally deprived communities, and to answer Charcot's present day critics we present a selection of patients from Kentucky's Appalachian countries with hysterial neurological disease. Their case histories are contrasted with those Charcot himself described and thereby form a modern commentary on such condition...

  1. Influence of colloids in experimental solubility studies of Ni in natural and synthetic aqueous media

    International Nuclear Information System (INIS)

    The estimation of nickel solubility values for performance assessment is impaired by the lack of experimentally verified solubility values in conditions relevant to actual nuclear waste disposal sites. For this reason, experimental nickel solubility studies were conducted in conditions relevant to a possible Finnish disposal site, Olkiluoto. Using an initial nickel concentration of 10-3 M, nickel solubility was approached from over-saturation in three aqueous media - natural fresh groundwater, synthetic saline groundwater, and cement-conditioned groundwater with added ferrous iron and sulfide. In addition to the nickel solubility values, nickel association with the particle and colloidal phases was measured. Almost 100% of the initial nickel was found associated with the separated particle phase in the natural groundwater and the cement-conditioned groundwater, and in only the natural groundwater about 0.04% or 0.4% with the separated colloidal fraction depending on the initially added amount of ferrous iron and sulfide. In the synthetic saline groundwater, all the nickel was found in the soluble fraction except for a minor fraction sorbed onto the walls of the sample bottle. Colloid-bound nickel did not have any practical influence on the solubility values obtained. The inverse behavior of Ni solubility and sorption in the natural groundwater compared to that in the other two aqueous phases studied was suspected to be caused by the unidentified yellow color of the groundwater for which indications of both possible organic and inorganic nature was obtained. Based on the measured results, the presence of sulfide and ferrous iron would decrease the amount of mobile nickel, both soluble and colloidal, in non-saline natural and cement-conditioned groundwater, whereas in saline groundwater nickel remains in the mobile phases. Copyright (2001) Material Research Society

  2. 水相钯催化Suzuki反应%Palladium-Catalyzed Suzuki Reaction in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    刘宁; 刘春; 金子林

    2012-01-01

    The palladium-catalyzed Suzuki cross-coupling reaction has become one of the most powerful tools for sp2-sp2 carbon-carbon bond formation. This coupling reaction is increasingly being applied in the synthesis of Pharmaceuticals, natural products and advanced functional materials. In recent years, developing aqueous systems for the Suzuki reaction has attracted attention from many researchers. This paper reviews the recent progress in the Suzuki reaction using neat water and aqueous-organic co-solvent as reaction media. A large number of different strategies for the Suzuki reaction in water have been developed, in which the authors aim at the solutions to the enhancement of the reactivity of the palladium-catalyzed Suzuki reaction using water-soluble ligands, surfactants, microwave assistance, or ligand-free system.%钯催化的Suzuki反应是构建Csp2-Csp2键的主要方法之一,已广泛应用于医药、天然产物及先进功能材料等联芳类化合物的合成.近年来,水相Suzuki反应引起了人们的高度关注.对以纯水及水/有机混溶剂为介质的水相Suzuki反应的研究进展作一综述,特别是围绕如何解决水相Suzuki反应活性的问题,以催化体系为主线,重点介绍了水溶性配体/钯、表面活性剂、微波促进的非水溶性配体/钯及无配体钯等催化体系在水相Suzuki反应中的应用.

  3. The Renaissance Conception Regarding Technology

    Directory of Open Access Journals (Sweden)

    Robert Arnăutu

    2011-11-01

    Full Text Available The Renaissance creates a clear-cut distinction between mechanical arts, which will come to be considered applied science by Bacon and Descartes, and fine arts. Dealing with the Renaissance approach to technology, this paper will focus, on the one hand, on those domains that combine theoretical and practical skills in order to create artifacts or to transform materials, and, on the other hand, with authors who debate the status of technological practices and knowledge. Thus, we will look at the developments and arguments regarding mechanics, alchemy, natural magic, mining and metallurgy, and at authors such as Georgius Agricola, Paracelsus, Masilio Ficino, Nicholas of Cusa, Galileo Galilei. The aim is to reconstruct the arguments regarding technology that challenged the established Scholastic-Aristotelian framework and made possible the Modern approaches.

  4. Renaissance Neurosurgery: Italy's Iconic Contributions.

    Science.gov (United States)

    Nanda, Anil; Khan, Imad Saeed; Apuzzo, Michael L

    2016-03-01

    Various changes in the sociopolitical milieu of Italy led to the increasing tolerance of the study of cadavers in the late Middle Ages. The efforts of Mondino de Liuzzi (1276-1326) and Guido da Vigevano (1280-1349) led to an explosion of cadaver-centric studies in centers such as Bologna, Florence, and Padua during the Renaissance period. Legendary scientists from this era, including Leonardo Da Vinci, Andreas Vesalius, Bartolomeo Eustachio, and Costanzo Varolio, furthered the study of neuroanatomy. The various texts produced during this period not only helped increase the understanding of neuroanatomy and neurophysiology but also led to the formalization of medical education. With increased understanding came new techniques to address various neurosurgical problems from skull fractures to severed peripheral nerves. The present study aims to review the major developments in Italy during the vibrant Renaissance period that led to major progress in the field of neurosurgery. PMID:26585723

  5. Augustinian Perspectives in the Renaissance

    OpenAIRE

    Bergvall, Åke

    2001-01-01

    The study investigates four areas in which the Augustinian presence was felt throughout the Renaissance: psychology, epistemology, the arts, and politics (one chapter is dedicated to each area). Augustine’s intellectual and spiritual development is interpreted as consisting of an early Plotinian period (ca. 386-396), and a later Pauline period (ca. 386-430). These influences resulted in two partially contradictory perspectives: one predominantly vertical (incorporeal and a-historical), the ot...

  6. Glycolic Acid Ethoxylate Lauryl Ether Performance as Drag Reducing Agent in Aqueous Media Flow in Pipelines

    Directory of Open Access Journals (Sweden)

    H.A. Abdul Bari

    2008-01-01

    Full Text Available In this study, Glycolic Acid Ethoxylate Lauryl Ether (GAELE anionic surfactant performance as drag reducing agent in aqueous media flow in pipelines was investigated. Testing section length L to pipe diameter D ration (L/D, addive concentration and solution flow rates were the major variables to be investigated in the present study. All the experimental study was carried in a build up experimental rig with three pipe diameters (0.0127, 0.0254 and 0.0381 m inside diameter. The experimental results showed that the (GAELE anionic can perform as a good drag reducing agent with maximum percentage drag reduction of 73% obtained in 39.37 of L/D for 600 ppm of solution. In 26.24 L/D the highest drag reduction obtained was 53% for 600 ppm of solution. The drag reduction increases corresponding with the increasing of L/D. The setup point where the effect of the drag reducer starts to take action was at Reynolds Number Re of 21000 in L/D equals to 39.37 and at Re = 30000 in 26.24 of L/D. From experimental results, it was shown that the critical wall shear stress occur at Re = 25000 in L/D = 39.37 and at Re = 35000 in L/D = 26.24.

  7. Oxidation of hydrogen peroxide by [NiIII(cyclam)]3+ in aqueous acidic media

    Indian Academy of Sciences (India)

    Sankaran Anuradha; Venkatapuram Ramanujam Vijayaraghavan

    2013-09-01

    The kinetics of oxidation of H2O2 by [NiIII(cyclam)]3+, [NiIIIL1], was studied in aqueous acidic media at 25°C and I = 0.5M (NaClO4). The [NiIIIL1] to [NiIIL1] reduction was found to be fast in the presence of Cu(II) ion than the oxidation of the cyclam ligand by ·OH. The rate constant showed an inverse acid dependence on H+ ion at the pH range 1-1.5. The presence of sulphate retards the reaction. Macrocylic ligand oxidation was followed spectrophotometrically by examining the oxidation of nickel(II) complexes of macrocyclic ligands such as 1,8-bis(2-hydroxyethyl)-1,3,6,8,10,13-hexaazacyclotetradecane (L2), -5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L3), rac-Me6[14]-4,11-dieneN4 (L4) by reaction with hydrogen peroxide. The rate constant for the cross reaction is discussed in terms of Marcus relationship.

  8. Brain 'imaging' in the Renaissance.

    Science.gov (United States)

    Paluzzi, Alessandro; Belli, Antonio; Bain, Peter; Viva, Laura

    2007-12-01

    During the Renaissance, a period of 'rebirth' for humanities and science, new knowledge and speculation began to emerge about the function of the human body, replacing ancient religious and philosophical dogma. The brain must have been a fascinating mystery to a Renaissance artist, but some speculation existed at that time on the function of its parts. Here we show how revived interest in anatomy and life sciences may have influenced the figurative work of Italian and Flemish masters, such as Rafael, Michelangelo and David. We present a historical perspective on the artists and the period in which they lived, their fascination for human anatomy and its symbolic use in their art. Prior to the 16th century, knowledge of the brain was limited and influenced in a dogmatic way by the teachings of Galen(1) who, as we now know, conducted his anatomical studies not on humans but on animals.(2) Nemesus, Bishop of Emesa, in around the year 400 was one of the first to attribute mental faculties to the brain, specifically to the ventricles. He identified two anterior (lateral) ventricles, to which he assigned perception, a middle ventricle responsible for cognition and a posterior ventricle for memory.(2,3) After a long period of stasis in the Middle Ages, Renaissance scholars realized the importance of making direct observations on dissected cadavers. Between 1504 and 1507, Leonardo da Vinci conducted experiments to reveal the anatomy of the ventricular system in the brain. He injected hot wax through a tube thrust into the ventricular cavities of an ox and then scraped the overlying brain off, thus obtaining, in a simple but ingenious way, an accurate cast of the ventricles.(2,4) Leonardo shared the belief promoted by scholarly Christians that the ventricles were the abode of rational soul. We have several examples of hidden symbolism in Renaissance paintings, but the influence of phrenology and this rudimentary knowledge of neuroanatomy on artists of that period is under

  9. Corrosion inhibitors for neutral aqueous media based on the products on sugar cane processing. 1.Furfural derivatives as inhibitors

    International Nuclear Information System (INIS)

    A series of carboxy-, nitrogen- and nitroderivaties of furfural - the main product of sugar cane processing (furancasboxylic acid, 5-nitrofurancarboxylic acid and its salts, furfurine, furfurylamine) was studied as inhibitors of iron and copper, corrosion in aqueous-salt media. Nitrofuroates of sodium and ammonium, which decelerate anode process, intensity cathode one and provide the stable passive state, are considered to be the most effective

  10. An Aqueous Media Based Approach for the Preparation of a Biosensor Platform Composed of Graphene Oxide and Pt-Black

    OpenAIRE

    SHI, JIN; Zhang, Hangyu; Snyder, Alexandra; WANG, MEI-XIAN; Xie, Jian; Porterfield, D. Marshall; Stanciu, Lia A.

    2012-01-01

    The combination of Pt nanoparticles and graphene was more effective in enhancing biosensing than either nanomaterial alone according to previous reports. Based on the structural similarities between water soluble graphene oxide (GrOx) and graphene, we report the fabrication of an aqueous media based GrOx/Pt-black nanocomposite for biosensing enhancement. In this approach GrOx acted as a nanoscale molecular template for the electrodeposition of Pt-black, an amorphously nanopatterned isoform of...

  11. Enantiomeric Separation of Antidepressant Trimipramine by Capillary Electrophoresis Combined with Electrochemiluminescence Detection in Aqueous-organic Media

    Institute of Scientific and Technical Information of China (English)

    YU Cai-xia; YUAN Bai-qing; YOU Tian-yan

    2011-01-01

    The antidepressant trimipramine(Tri) enantiomers were successfully separated by capillary electrophoresis(CE) coupled with electrochemiluminescence(ECL) detection in aqueous-organic media. A dual cyclodextrin(CD)system combining β-CD and hydroxypropyl-β-cyclodextrin(HP-β-CD) was used as chiral selector. Acetonitrile(ACN)was added to the running buffer to improve the separation efficiency, detection sensitivity and repeatability. The method was also successfully applied to the chiral separation of Tri in spiked human urine sample.

  12. Lipase in biphasic alginate beads as a biocatalyst for esterification of butyric acid and butanol in aqueous media.

    Science.gov (United States)

    Ng, Choong Hey; Yang, Kun-Lin

    2016-01-01

    Esterification of organic acids and alcohols in aqueous media is very inefficient due to thermodynamic constraints. However, fermentation processes used to produce organic acids and alcohols are often conducted in aqueous media. To produce esters in aqueous media, biphasic alginate beads with immobilized lipase are developed for in situ esterification of butanol and butyric acid. The biphasic beads contain a solid matrix of calcium alginate and hexadecane together with 5 mg/mL of lipase as the biocatalyst. Hexadecane in the biphasic beads serves as an organic phase to facilitate the esterification reaction. Under optimized conditions, the beads are able to catalyze the production of 0.16 mmol of butyl butyrate from 0.5 mmol of butyric acid and 1.5 mmol of butanol. In contrast, when monophasic beads (without hexadecane) are used, only trace amount of butyl butyrate is produced. One main application of biphasic beads is in simultaneous fermentation and esterification (SFE) because the organic phase inside the beads is very stable and does not leach out into the culture medium. SFE is successfully conducted with an esterification yield of 6.32% using biphasic beads containing iso-octane even though the solvent is proven toxic to the butanol-producing Clostridium spp. PMID:26672465

  13. Layered Double Hydroxides as Effective Adsorbents for U(VI and Toxic Heavy Metals Removal from Aqueous Media

    Directory of Open Access Journals (Sweden)

    G. N. Pshinko

    2013-01-01

    Full Text Available Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA, diethylenetriaminepentaacetic acid (DTPA, and hexamethylenediaminetetraacetic acid (HMDTA and heat-treated form Zn4Al2O7, to adsorb uranium(VI and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to correlate with the stability of their complexes with the mentioned chelating agents in a solution. The synthesized layered double hydroxides (LDHs containing chelating agents in the interlayer space are rather efficient for sorption purification of aqueous media free from U(VI irrespective of its forms of natural abundance (including water-soluble bi- and tricarbonate forms and from heavy metal ions. [Zn4Al2(OH12]·EDTA·nH2O is recommended for practical application as one of the most efficient and inexpensive synthetic adsorbents designed for recovery of both cationic and particularly important anionic forms of U(VI and other heavy metals from aqueous media. Carbonate forms of LDHs turned out to be most efficient for recovery of Cu(II from aqueous media with pH0≥7 owing to precipitation of Cu(II basic carbonates and Cu(II hydroxides. Chromate ions are efficiently adsorbed from water only by calcinated forms of LDHs.

  14. Nonaqueous capillary electrophoresis with laser-induced fluorescence detection: a case study of comparison with aqueous media.

    Science.gov (United States)

    Zhou, Lei; Wang, Weiping; Wang, Shumin; Hui, Yang; Luo, Zhi; Hu, Zhide

    2008-03-24

    A novel method based on separation by nonaqueous capillary electrophoresis (NACE) combined with laser-induced fluorescence (LIF) detection was developed and compared with classic aqueous modes of electrophoresis in terms of resolution of solutes of interest and sensitivity of the fluorescence detection. Catecholamines derivatized with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) were chosen as test analytes for their subtle fluorescence properties. In aqueous systems, capillary zone electrophoresis (CZE) was not suitable for the analysis of test analytes due to complete fluorescence quenching of NBD-labeled catecholamines in neat aqueous buffer. The addition of micelles or microemulsion droplets into aqueous running buffer can dramatically improve the fluorescence response, and the enhancement seems to be comparable for micellar electrokinetic chromatography (MEKC) and microemulsion electrokinetic chromatography (MEEKC). As another alternative, NACE separation was advantageous when performing the analysis under the optimum separation condition of 20mM sodium tetraborate, 20mM sodium dodecyl sulfate (SDS), 0.1% (v/v) glacial acetic acid, 20% (v/v) acetonitrile (ACN) in methanol medium after derivatization in ACN/dimethyl sulfoxide (DMSO) (3:2, v/v) mixed aprotic solvents containing 20mM ammonium acetate. Compared with derivatization and separation in aqueous media, NACE-LIF procedure was proved to be superior, providing high sensitivity and short migration time. Under respective optimum conditions, the NACE procedure offered the best fluorescence response with 5-24 folds enhancement for catecholamines compared to aqueous procedures. In addition, the mechanisms of derivatization and separation in nonaqueous media were elucidated in detail. PMID:18328323

  15. Organic Reactions in Aqueous Media (by Chao-Jun Li and Tak-Hang Chan)

    Science.gov (United States)

    Rosan, Reviewed Alan M.

    2000-06-01

    This concise book joins the series of Wiley Interscience special topic publications. In seven chapters it selectively reviews the burgeoning literature on organic reactions conducted in water or in aqueous media as a reaction cosolvent, nicely complementing another recent book on the subject by Grieco. Following a short introduction there are six chapters that vary in length from 10 to 50 pages; they cover pericyclic reactions, nucleophilic additions and substitutions, metal-mediated reactions, transition metal-catalyzed reactions, oxidation and reduction reactions, and industrial applications. These chapters, each of which is prefaced with a short provocative quotation, also vary in depth, containing from 11 to more than 180 references. The literature is complete through 1996 and commendably includes citations of original papers by Barbier, Faraday, Frankland, Grignard, Kolbe, Lapworth, and Reformatsky as well as references to selected U.S. and foreign patents and the Russian literature. There is a subject index but no author index. This book is timely and effective. From the title, one might expect a broad discussion of the unique properties of water and water-soluble components (salts, surfactants, etc.) that would be thought to bear on organic reactivity. The first chapter opens by noting that water is the most abundant volatile material in comets and briefly describes those properties that suggest its utility as a solvent or cosolvent, summarizing the potential technical, economic, and environmental advantages. Also described are the remarkable changes in density, conductance, heat capacity, dielectric constant, and ionization constant that accompany the transition to the critical point, but the emphasis here is on the effect of water under non-critical conditions. Discussion of the structure of liquid water and the role of hydrogen bonding in mediating molecular recognition events is abbreviated. In fact, the term "hydrogen bond" is surprisingly absent from

  16. Control of electrostatic interactions between F-actin and genetically modified lysozyme in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Lori K.; Xian, Wujing; Guaqueta, Camilo; Strohman, Michael J.; Vrasich, Chuck R.; Luijten, Erik; Wong, Gerard C.L. (UIUC)

    2008-07-11

    The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

  17. Control of Electrostatic Interactions Between F-Actin And Genetically Modified Lysozyme in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, L.K.; Xian, W.; Guaqueta, C.; Strohman, M.; Vrasich, C.R.; Luijten, E.; Wong, G.C.L.

    2009-06-04

    The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

  18. Control of electrostatic interactions between F-actin and genetically modified lysozyme in aqueous media

    International Nuclear Information System (INIS)

    The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

  19. Control of Electrostatic Interactions Between F-Actin And Genetically Modified Lysozyme in Aqueous Media

    International Nuclear Information System (INIS)

    The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

  20. Adsorption of arsenic from aqueous media using lateritic minerals. Equilibrium, kinetic and thermodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Nasir; Daud, Muhammad [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.

    2014-07-01

    The sorption behavior of arsenic on minerals from a lateritic weathering has been investigated to evaluate its potential for the decontamination of arsenic ions from aqueous media. Various physicochemical parameters such as pH, equilibration time, adsorbent dose, concentration of adsorbate, effect of diverse ions and temperature were studied in order to simulate the best conditions under which this material can be used as an adsorbent, employing batch method and radiotracer technique. Maximum adsorption was observed in buffer solutions having pH of 2.0 and 8-9, using 0.5 g of adsorbent for 6.674 x 10{sup -5} mol L{sup -1} arsenic concentration in 10 min equilibration time. The sorption data followed the pseudo-second order reaction kinetics. The adsorption data fit both the Freundlich and Dubinin-Radushkevich isotherm equations over the range of 3.195 x 10{sup -5} to 3.195 x 10{sup -3} mol L{sup -1} arsenic concentration. The characteristic Freundlich constants i.e. 1/n = 0.427 ± 0.009 and K = 3.04 x 10{sup -4} ± 1.46 x 10{sup -5} mol g{sup -1} have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 12.00 ± 0.38 kJ mol{sup -1} indicating ion-exchange mechanism of chemisorption. The uptake of arsenic increases with the rise in temperature (278.16-323.16 K). Thermodynamic quantities i.e.ΔG, ΔS and ΔH have also been calculated for the system. The sorption process was found to be endothermic. (orig.)

  1. The Suzuki reaction in aqueous media promoted by P, N ligands.

    Science.gov (United States)

    Weeden, Jason A; Huang, Rongcai; Galloway, Kathryn D; Gingrich, Phillip W; Frost, Brian J

    2011-01-01

    The synthesis and structure of palladium complexes of trisubstituted PTA derivatives, PTA(R3), are described. Water-soluble phosphine ligands 1,3,5-triaza-7-phosphaadmantane (PTA), tris(aminomethyl)phosphine trihydrobromide, tri(aminomethyl) phosphine, 3,7-dimethyl-1,5,7-triaza-3-phosphabicyclo[3,3,1]nonane (RO-PTA), 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (DAPTA), lithium 1,3,5-triaza-7-phosphaadamantane-6-carboxylate (PTA-CO₂Li), 2,4,6-triphenyl-1,3,5-triaza-7-phosphatricyclo [3.3.1.1]decane, and 2,4,6-triphenyl-1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane were used as ligands for palladium catalyzed Suzuki reactions in aqueous media. RO-PTA in combination with palladium acetate or palladium chloride was the most active catalyst for Suzuki cross coupling of aryl bromides and phenylboronic acid at 80 °C in 1:1 water:acetonitrile. The activity of Pd(II) complexes of RO-PTA is comparable to PPh₂(m-C₆H₄SO₃Na) (TPPMS) and P(m-C₆H₄SO₃Na)₃ (TPPTS) and less active than tri(4,6-dimethyl-3-sulfonatophenyl)phosphine trisodium salt (TXPTS). Activated, deactivated, and sterically hindered aryl bromides were examined, with yields ranging from 50% to 90% in 6 h with 5% palladium precatalyst loading. X-ray crystal structures of (RO-PTA)PdCl₂, (PTA(R3))₂PdCl₂ (R = Ph, p-tert-butylC₆H₅), and PTA(R3) (R = p-tert-butylC₆H₅) are reported. PMID:21788930

  2. Modeling reactive geochemical transport of concentrated aqueous solutions in variably saturated media

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guoxiang; Zheng, Zuoping; Wan, Jiamin

    2004-01-28

    Concentrated aqueous solutions (CAS) have unique thermodynamic and physical properties. Chemical components in CAS are incompletely dissociated, especially those containing divalent or polyvalent ions. The problem is further complicated by the interaction between CAS flow processes and the naturally heterogeneous sediments. As the CAS migrates through the porous media, the composition may be altered subject to fluid-rock interactions. To effectively model reactive transport of CAS, we must take into account ion-interaction. A combination of the Pitzer ion-interaction and the ion-association model would be an appropriate way to deal with multiple-component systems if the Pitzer' parameters and thermodynamic data of dissolved components and the related minerals are available. To quantify the complicated coupling of CAS flow and transport, as well as the involved chemical reactions in natural and engineered systems, we have substantially extended an existing reactive biogeochemical transport code, BIO-CORE{sup 2D}{copyright}, by incorporating a comprehensive Pitzer ion-interaction model. In the present paper, the model, and two test cases against measured data were briefly introduced. Finally we present an application to simulate a laboratory column experiment studying the leakage of the high alkaline waste fluid stored in Hanford (a site of the U.S. Department of Energy, located in Washington State, USA). With the Pitzer ion-interaction ionic activity model, our simulation captures measured pH evolution. The simulation indicates that all the reactions controlling the pH evolution, including cation exchanges, mineral precipitation and dissolution, are coupled.

  3. Nuclear power renaissance or demise?

    Energy Technology Data Exchange (ETDEWEB)

    Dossani, Umair

    2010-09-15

    Nuclear power is going through a renaissance or demise is widely debated around the world keeping in mind the facts that there are risks related to nuclear technology and at the same time that is it environmentally friendly. My part of the argument is that there is no better alternative than Nuclear power. Firstly Nuclear Power in comparison to all other alternative fuels is environmentally sustainable. Second Nuclear power at present is at the dawn of a new era with new designs and technologies. Third part of the debate is renovation in the nuclear fuel production, reprocessing and disposal.

  4. Dissolution Mechanism of Upconverting AYF4:Yb,Tm (A = Na or K) Nanoparticles in Aqueous Media.

    Science.gov (United States)

    Lisjak, Darja; Plohl, Olivija; Vidmar, Janja; Majaron, Boris; Ponikvar-Svet, Maja

    2016-08-16

    The dissolution of upconverting AYF4:Yb,Tm (A = Na or K) nanoparticles (UCNPs) in aqueous media was systematically studied. UCNPs with a cubic structure and sizes of between 10 and 33 nm were synthesized solvothermally in ethylene glycol at 200 °C. The UCNPs of both compositions showed an upconversion fluorescence emission characteristic of Tm(3+). The effects of the A cation, the particle size, the temperature, the pH, and the composition of the aqueous medium on the dissolution of the UCNPs were evaluated. The degree of dissolution was determined from the fraction of dissolved fluoride (F(-)) using potentiometry. Unexpectedly, the composition of aqueous media had the most significant effect on the dissolution of the UCNPs. The highest degree of dissolution and rate were measured for the phosphate-buffered saline (PBS), which can be explained by the formation of stable lanthanide compounds with phosphates. The degree of dissolution was much lower in water and in the phthalate buffer, which was attributed to the release of F(-) as a result of the hydrolysis of the UCNPs' surfaces. PMID:27459496

  5. Non-invasive Technology to Study Local Passivity Breakdown of Metal Alloys in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Alan M. Shipley

    2005-03-09

    Little is known about the basic mechanisms of passive oxide breakdown, repair, and localized corrosion of metals. A non-invasive instrument and methods have been developed to study local events and mechanisms that initiate passivity breakdown and subsequent corrosion of metals in aqueous media. The ''difference viewer imaging technique'' (DVIT) is a rapid, real time, non-invasive assay to study metal surfaces in corrosive solutions. It has a spatial resolution of less than 10.0 ?m (1cm x 1cm sample, 1000 x 1000 pixel CCD) to observe initial corrosion processes of the order of seconds. DVIT is a software-controlled video microscopy system and methods to collect and analyze pixel changes in video images. These images are recorded from a digital CCD video camera and frame grabber package using visible light for illumination. The DVIT system detects changes in video images that represent initial corrosive events that lead to passivity breakdown and re-passivation on metal surfaces in situ. This visual technique is easy to use and apply. It compliments other metal surface measurement techniques and can be used simultaneously with them. DVIT has proven to be more sensitive in detecting changes than scanning microelectrode techniques. DVIT is also much easier than other methods to apply and operate. It has the further advantage of providing a real time image of the entire metal surface under study instead of waiting for a microelectrode to scan a number of data points over a sample then plot the results. This project has fulfilled all specifications as outlined in the Department of Energy solicitation responsible for this grant application and award and exceeded a number of the specifications. Applicable Electronics, Inc. now has a marketable instrument and software package available for sale now. Further development of the system will be ongoing as driven by customer needs and discoveries. This technology has immediate applications in corrosion labs

  6. Mass spectrometric detection of proteins in non-aqueous media : the case of prion proteins in biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Douma, M.D.; Kerr, G.M.; Brown, R.S.; Keller, B.O.; Oleschuk, R.D. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemistry

    2008-08-15

    This paper presented a filtration method for detecting protein traces in non-aqueous media. The extraction technique used a mixture of acetonitrile, non-ionic detergent and water along with filter disks with embedded C{sub 8}-modified silica particles to capture the proteins from non-aqueous samples. The extraction process was then followed by an elution of the protein from the filter disk and direct mass spectrometric detection and tryptic digestion with peptide mapping and MS/MS fragmentation of protein-specific peptides. The method was used to detect prion proteins in spiked biodiesel samples. A tryptic peptide with the sequence YGQGSPGGNR was used for unambiguous identification. Results of the study showed that the method is suitable for the large-scale testing of protein impurities in tallow-based biodiesel production processes. 33 refs., 6 figs.

  7. Influence of enzymes on the oil extraction processes in aqueous media

    Directory of Open Access Journals (Sweden)

    Ricochon Guillaume

    2010-11-01

    Full Text Available The methods of oil aqueous extraction process (AEP assisted by enzymes are, over the last 50 years, an alternative designed to replace traditional methods of extraction using organic solvents. To extract the oil using an AEP, the use of specific enzymes, able to hydrolyze some or all components of seeds, can significantly increase the yields of extraction. Hydrolyzing the different constituents of cell walls (cellulose, hemicellulose, pectins, proteins, etc., enzymes are able to enhance the liberation of the oil. A number of physico-chemical parameters must also be considered for the better expression of the enzymatic mixture, while maintaining the quality of oils and meals. This article presents the various factors influencing the release of oil in aqueous media and the main results obtained by this process on various substrates.

  8. Asymmetric Transfer Hydrogenation of Prochiral Ketones in Aqueous Media with New Water-Soluble Chiral Vicinal Diamine as Ligand

    Institute of Scientific and Technical Information of China (English)

    ZHU Jin; MA Ya-Ping; LIU Hui; CHEN Li; CUI Xin; DENG Jin-Gen

    2003-01-01

    @@ As a consequence of the increasing demand for atom economy and environmental friendly methods, the water soluble ligands and their metal complexes are of great interest in catalytic synthesis because of simpler product sepa ration and the possibility of recycling. [1] Unique reactivity and selectivity are often observed in aqueous reactions. [2]Recently, we have developed a new water-soluble chiral vicinal diamine and synthesized its mono-N-tosylated derivative for the first time. The application of its mono-N-tosylated derivative in catalytic asymmetric transfer hydrogenation of prochiral ketones was examined in aqueous media. High activity (up to > 99 % conv. ) and good enatioselectivity ( up to 98% ee ) were achieved for most of prochiral aromatic ketones in organic solvent free system. [3

  9. Stability of Colistin and Colistin Methanesulfonate in Aqueous Media and Plasma as Determined by High-Performance Liquid Chromatography

    OpenAIRE

    Jian LI; Milne, Robert W.; Nation, Roger L; Turnidge, John D.; Coulthard, Kingsley

    2003-01-01

    The stabilities of colistin and colistin methanesulfonate (CMS) in different aqueous media were studied by specific high-performance liquid chromatography (HPLC) methods. Colistin was stable in water at 4 and 37°C for up to 60 days and 120 h, respectively. However, degradation was observed when colistin was stored in isotonic phosphate buffer (0.067 M, pH 7.4) and human plasma at 37°C. The stability of CMS from three different sources in water was explored by strong-anion-exchange (SAX) HPLC ...

  10. On the importance of aqueous diffusion and electrostatic interactions in advection-dominated transport in saturated porous media

    DEFF Research Database (Denmark)

    Rolle, Massimo

    2015-01-01

    advection-dominated flow through conditions. When the solutes are charged species, besides the magnitude of their aqueous diffusion coefficients also their electrostatic interactions play a significant role in the displacement of the different species. Under flow-through conditions this leads to...... under different advection-dominated conditions and in homogeneous and heterogeneous porous media. The interpretation of the experimental results requires a multicomponent modeling approach with an accurate description of local hydrodynamic dispersion and explicitly accounting for the cross-coupling of...... dispersive fluxes due to the Coulombic interactions between the charged species....

  11. Study of the europium behavior in aqueous media; Estudio sobre el comportamiento del europio en medios acuosos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez R, E.; Jimenez R, M.; Solache R, M.; Martinez M, V. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    Europium as waste can produce a pollution problem in water that is in contact with it, what would has a heavy environmental impacts, because of the possibilities of diffusion of these wastes from their place of confinement or storage until the geo and biosphere. The solution of such problem requires of a lot of knowledge over the behavior of several chemical elements such as europium in aqueous solutions. In this work it was used a low ion force (0.02 M). The data set will allow extrapolate the hydrolytic behavior of europium in too much minors ion force media, such as the ground waters, including in ion force zero.

  12. Covalent and non-covalent functionalization and solubilization of double-walled carbon nanotubes in nonpolar and aqueous media

    Indian Academy of Sciences (India)

    L S Panchakarla; A Govindaraj

    2008-11-01

    Double-walled carbon nanotubes (DWNTs) have been functionalized by both covalent and non-covalent means. Covalent functionalization has been carried out by attaching an aliphatic amide function to DWNTs which enable solubilization in non-polar solvents. Solubilization in non-polar solvents has also been accomplished by non-covalent functionalization by using 1-pyrenebutanoicacid succinimidyl ester (PYBS). Non-covalent functionalization of DWNTs has been carried out by using polyethylene glycol (PEG) and polyoxyethylene(40)nonylphenyl ether (IGPAL), both of which enable solubilization in aqueous media. These functionalized DWNTs have been characterized by transmission electron microscopy, IR and Raman spectroscopy.

  13. Dissolution and reaction studies of CsZr2(PO4)3 and Zr phosphates in aqueous media

    International Nuclear Information System (INIS)

    Cs dissolution kinetics for CsZr2(PO4)3 in a variety of aqueous media at 700C approximately obeyed a first-order law. However in 0.1 M NaHCO3, a t/sup 1/2/ law was appropriate. The Cs extraction was a minimum under neutral conditions. In the pH range of 1 to 4, the Cs extraction varied approximately as [H+]03 and was a stronger function of pH in alkaline media. The survival of α-Zr phosphate gel in water at 3000C was essentially confirmed. ZrP2O7 reacted sluggishly with water at 200 to 3000C to produce an apparently fully protonated analogue of NaZr2(PO4)3

  14. Nuclear renaissance or premature try

    International Nuclear Information System (INIS)

    After the economic failure of the 70's and not having been able to solve for decades its multiple problems, the nuclear industry was suffering a slow but inescapable agony. However, the need to reduce CO2 emissions and the likely arrival of the worldwide peak of oil production have infused new life to the nuclear option, and it has again become one of the main topics of discussion in the worldwide energy debate. But in this debate we tend to forget that the causes of the abrupt end of the first nuclear era have not disappeared, and that for this reason it may well be that we are lead to a repetition of the events that induced its first demise. The much talked nuclear renaissance is thus likely to end up as a premature miscarriage. (Author)

  15. Investigation of Electrochemical Charging Behaviors of“Naked” Gold Nanoparticles Ensembles in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    程文龙; 韩晓军; 彭章泉; 董绍俊; 汪尔康

    2002-01-01

    Gold nanoparticles were imnoobilized onto the electrode surface by simple self-assembly technique.Interestingly,the ensembles of these nanoparticles exhibit quantized charging behaviors in aqueous solution.Possible mechanism for such behaviors was proposed.

  16. Investigation of Electrochemical Charging Behaviors of "Naked" Gold Nanoparticles Ensembles in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    CHENG,Wen-Long(程文龙); HAN,Xiao-Jun(韩晓军); PENG,Zhang-Quan(彭章泉); DOGN,Shao-Jun(董绍俊); WANG,Er-Kang(汪尔康)

    2002-01-01

    Gold nanoparticles were immobilized onto the electrode surface by simple self-assembly technique. Interestingly, the ensmbles of these nanoparticles exhibit quantized charging behaviors in aqueous solution. Possible mechanism for such behaviors was proposed.

  17. Lewis Acid Pairs for the Activation of Biomass-derived Oxygenates in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Yuriy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-09-14

    The objective of this project is to understand the mechanistic aspects behind the cooperative activation of oxygenates by catalytic pairs in aqueous media. Specifically, we will investigate how the reactivity of a solid Lewis acid can be modulated by pairing the active site with other catalytic sites at the molecular level, with the ultimate goal of enhancing activation of targeted functional groups. Although unusual catalytic properties have been attributed to the cooperative effects promoted by such catalytic pairs, virtually no studies exist detailing the use heterogeneous water-tolerant Lewis pairs. A main goal of this work is to devise rational pathways for the synthesis of porous heterogeneous catalysts featuring isolated Lewis pairs that are active in the transformation of biomass-derived oxygenates in the presence of bulk water. Achieving this technical goal will require closely linking advanced synthesis techniques; detailed kinetic and mechanistic investigations; strict thermodynamic arguments; and comprehensive characterization studies of both materials and reaction intermediates. For the last performance period (2014-2015), two technical aims were pursued: 1) C-C coupling using Lewis acid and base pairs in Lewis acidic zeolites. Tin-, zirconium-, and hafnium containing zeolites (e.g., Sn-, Zr-, and Hf-Beta) are versatile solid Lewis acids that selectively activate carbonyl functional groups. In this aim, we demonstrate that these zeolites catalyze the cross-aldol condensation of aromatic aldehydes with acetone under mild reaction conditions with near quantitative yields. NMR studies with isotopically labeled molecules confirm that acid-base pairs in the Si-O-M framework ensemble promote soft enolization through α-proton abstraction. The Lewis acidic zeolites maintain activity in the presence of water and, unlike traditional base catalysts, in acidic solutions. 2) One-pot synthesis of MWW zeolite nanosheets for activation of bulky substrates. Through

  18. Synthesis of Dendrimer-supported Chiral Bis(oxazoline) Ligands and Their Applications in Aldol Reaction via Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-min; YANG Bai-yuan; ZHANG Yi-li; QU Xue; FAN Qing-hua

    2004-01-01

    Chiral bis(oxazoline) ligands have been applied in many enatioselective reactions.Recently, studies of the immobilization of bis(oxazoline) on both soluble and insoluble supports have been of great interest. Among the different methods to anchor the homogeneous catadysts, a soluble, polymer-supported catalyst usually achieves higher stereoselectivity and activity because the catalysis can be separated and recycled via simple methods such as solvent precipitation.Dendrimers are highly branched macromolecules having precisely defined molecular structures with nano-scale size. Compared with soluble polymer supports, the dendrimer architecture may offer better control of the deposition of the catalytic species in soluble polymer-based catalysts. Therefore,such catalysts may fill the gap between homogeneous and heterogeneous catalysis and combine the advantages of both.In this paper, we report the synthesis of bis(oxazoline)-centered dendrimers and their application in Mukaiyama aldol reaction in aqueous media. It was found that the dendritic chiral bis(oxazolines)showed the similar reactivities and enantioselectivities in the asymmetric copper-catalyzed aldol reaction in aqueous media in comparison to the corresponding small molecular ligands.

  19. Mixed system of ionic liquid and non-ionic surfactants in aqueous media: Surface and thermodynamic properties

    International Nuclear Information System (INIS)

    Highlights: • Interaction of ionic liquid and ethylene oxide based non-ionic surfactants in aqueous media. • Evaluation of various surface properties and thermodynamic parameters. • Micellar growth ensues from exothermic to endothermic with increase in temperature. • Micelle formation is enthalpy driven at low temperature and entropy driven at higher temperature. • The micellization power and adsorption proficiency decreased at high IL concentrations. - Abstract: The mixed system of ionic liquid (IL) tetraethyl ammonium tetrafluoroborate [TEA(BF4)] and numerous ethylene oxide based non-ionic surfactants in aqueous media were studied using surface tension, viscosity and dynamic light scattering (DLS) measurements. Various surface properties like critical micelle concentration (cmc), maximum surface excess concentration (Γmax), minimum surface area per surfactant molecule (Amin), surface tension at the cmc (γcmc), adsorption efficiency (pC20), and effectiveness of surface tension reduction (πcmc) as well as thermodynamic parameters of micellization have been determined. DLS and viscosity measurements revealed that the micellar growth was attributed to the bridged solvophilicity of the POE chain in surfactants at elevated temperatures. In most of the cases, the progression ensues from exothermic to endothermic with increase in temperature of the mixed system. Thermodynamic parameter indicates that the micelle formation process is enthalpy driven at low temperature and entropy driven at higher temperature

  20. Removal of Cu(II) in aqueous media by biosorption using water hyacinth roots as a biosorbent material

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Jiachuan; Feng Huimin [Advanced Lab for Environmental Research and Technology, USTC-CityU, Suzhou, 215123 (China); Department of Chemistry, University of Science and Technology of China, Hefei, 230026 (China); Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong); Lam, Michael Hon-Wah, E-mail: bhmhwlam@cityu.edu.hk [Advanced Lab for Environmental Research and Technology, USTC-CityU, Suzhou, 215123 (China); Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong); Lam, Paul Kwan-Sing [Advanced Lab for Environmental Research and Technology, USTC-CityU, Suzhou, 215123 (China); Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong); Ding Yanwei [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, 230026 (China); Yu Hanqing, E-mail: hqyu@ustc.edu.cn [Advanced Lab for Environmental Research and Technology, USTC-CityU, Suzhou, 215123 (China); Department of Chemistry, University of Science and Technology of China, Hefei, 230026 (China)

    2009-11-15

    Water hyacinth roots were employed as a biosorbent to remove Cu(II) in aqueous media. Nitrogen adsorption/desorption analysis revealed that the biosorbent was mesoporous with a relatively small surface area. Equilibrium biosorption isotherms showed that the water hyacinth roots possessed a high affinity and sorption capacity for Cu(II) with a monolayer sorption capacity of 22.7 mg g{sup -1} at initial pH 5.5. Kinetics study at different temperatures revealed that the sorption was a rapid and endothermic process. The activation energy for Cu(II) sorption was estimated to be 30.8 kJ mol{sup -1}, which is typical of activated chemisorption processes. The sorption mechanism was investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, effect of pH and calcium release. These analyses suggested that the biosorption mainly involved the ion exchange of Cu(II) with cations and complex formation with functional groups on the surface of the roots. All the results showed that water hyacinth roots are an alternative low-cost biosorbent for the removal of Cu(II) from aqueous media.

  1. Removal of Cu(II) in aqueous media by biosorption using water hyacinth roots as a biosorbent material

    International Nuclear Information System (INIS)

    Water hyacinth roots were employed as a biosorbent to remove Cu(II) in aqueous media. Nitrogen adsorption/desorption analysis revealed that the biosorbent was mesoporous with a relatively small surface area. Equilibrium biosorption isotherms showed that the water hyacinth roots possessed a high affinity and sorption capacity for Cu(II) with a monolayer sorption capacity of 22.7 mg g-1 at initial pH 5.5. Kinetics study at different temperatures revealed that the sorption was a rapid and endothermic process. The activation energy for Cu(II) sorption was estimated to be 30.8 kJ mol-1, which is typical of activated chemisorption processes. The sorption mechanism was investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, effect of pH and calcium release. These analyses suggested that the biosorption mainly involved the ion exchange of Cu(II) with cations and complex formation with functional groups on the surface of the roots. All the results showed that water hyacinth roots are an alternative low-cost biosorbent for the removal of Cu(II) from aqueous media.

  2. Formation of magnetite (Fe3O4)in aqueous media and properties of the interface magnetite/solution

    International Nuclear Information System (INIS)

    The formation of Fe3O4 particles in aqueous media and the properties of the Fe3O4/aqueous solution interface are studied. This system is of particular interest in nuclear reactor chemistry, since Fe3O4 was identified as the main component of the corrosion products of nuclear power plants cooled with pressurized water, of the Atucha I and II, and Embalse type. Four methods for the synthesis of Fe3O4 are described: a) controlled oxidation of Fe(OH)2 in the presence of NaNO3 at 25 deg C; b) controlled oxidation of Fe(OH)2 in the presence of NaNO3 and N2H4 and at 100 deg C; c) alkalinization of a F2+ and Fe3+ solutions at 80 deg C; d) simultaneous oxidation and alkalinization of a Fe2+. The interfacial properties of Fe3O4 particles suspended in aqueous solutions of indifferent electrolytes are described. These properties are essential for the activity transport associated with the corrosion products. Finally, the adsorption of H3BO3, Hsub(n)PO4sup(n-3) and n Co(II) in the Fe3O4/solution interface at 30 deg C. It is concluded that the adsorbed species are chemically bonded to surface metal ions. (M.E.L.)

  3. Substrate-induced coagulation (SIC) of nano-disperse alumina in non-aqueous media: The dispersibility and stability of alumina in N-methyl-2-pyrrolidinone

    OpenAIRE

    Basch, Angelika; Strnad, Simona

    2011-01-01

    This work investigated colloidal properties such as the zeta-potential, the electrophoretic mobilities and the wetting behaviour of alumina dispersed in non-aqueous media. Non-aqueous dispersions of alumina were prepared in the solvent N-methyl-2-pyrrolidinone (NMP). The wetting behaviour of alumina in NMP was characterized by the powder contact angle method and the Wilhemy plate method. The behaviour of the dispersion should provide information for the development of a substrate-induced coag...

  4. Determination of uranyl nitrate diffusion coefficients in organic and aqueous media using the porous diaphragm method

    International Nuclear Information System (INIS)

    The diffusion coefficient is one of the parameters necessary for the obtention of the extraction exponential coefficients, that are contained within the H.T.U. (height of transfer unity) calculation expression, when operating with continuous organic phase. The organic phase used was tri-n-butyl-phosphate (TBP) and varsol in the 35% and 65% proportions respectively. After each experiment, the uranium content present in each compartment was spectrophotometrically determined and the quantities contained in the aqueous phases were determined by means of volumetric titration. It was found out that the uranyl ion diffusion coefficient is two and one half times less in organic phase, this just being attributed to the greater interactions of the uranyl ions in organic than in aqueous medium

  5. Studies on the Gamma-Initiated Polymerization of Vinyl Acetate in Aqueous Media

    International Nuclear Information System (INIS)

    1. Gamma-initiated Polymerization of Vinyl Acetate in an Aqueous Solution of Uranyl Acetate. From a consideration of the rate and degree of polymerization of the gamma- initiated polymerization of vinyl-acetate in three systems (vinyl acetate-acetic acid, vinyl acetate-acetic acid, water, and vinyl acetate-acetic acid-water-uranyl acetate), the G-values of each component for the initiation of polymerization are estimated as follows G vinylacetateinitiation = 10,6; G aceticacidinitiation = 52; G waterinitiation = 480; G uranylacetateinitiation = 23,000. 2. Gamma-initiated Polymerization of Vinyl Acetate in Aqueous Solutions of Detergents. The emulsion polymerization of vinyl acetate in the presence of anionic, cationic and non ionic detergents is discussed. The rate is found to be greatest for the anionic detergent lauryl benzene sulphonate. The rate and degree of polymerization increase with detergent concentration. It is found that the rate of polymerization is ∝ (Intensity)0.25.

  6. OXIDATIVE POLYMERIZATION BEHAVIOR OF 2,6-DIMETHYLPHENOL IN AQUEOUS MEDIA WITH POTASSIUM FERRICYANIDE

    Institute of Scientific and Technical Information of China (English)

    Cheng Gu; Jin-hua Zhu; Bao-qing Shentu; Qun Liu; Zhi-xue Weng

    2009-01-01

    The effects of potassium ferricyanide, sodium n-dodecyl sulfate, sodium hydroxide and temperature on the molecular weight and the yield of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) synthesized in an aqueous medium were studied. It was found that oxygen in air had little influence on the oxidative polymerization of 2,6-dimethylphenol (DMP) in the aqueous medium, and potassium ferricyanide was only an oxidant during the oxidative polymerization of DMP. Sodium n-dodecyl sulfate could stabilize polymer particles and facilitate the oxidative polymerization of DMP on the surface of polymer particles, which resulted in the increase of the molecular weight of PPO. The yield and molecular weight of PPO increased significantly with NaOH concentration at first and then decreased with NaOH concentration. The high molecular weight PPO with high yield was obtained at 50℃, but both the yield and molecular weight of PPO decreased with the further increase of temperature.

  7. Synthesis of Starch-Stabilized Ag Nanoparticles and Hg2+Recognition in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Fan Yingju

    2009-01-01

    Full Text Available Abstract The starch-stabilized Ag nanoparticles were successfully synthesized via a reduction approach and characterized with SPR UV/Vis spectroscopy, TEM, and HRTEM. By utilizing the redox reaction between Ag nanoparticles and Hg2+, and the resulted decrease in UV/Vis signal, we develop a colorimetric method for detection of Hg2+ion. A linear relationship stands between the absorbance intensity of the Ag nanoparticles and the concentration of Hg2+ion over the range from 10 ppb to 1 ppm at the absorption of 390 nm. The detection limit for Hg2+ions in homogeneous aqueous solutions is estimated to be ~5 ppb. This system shows excellent selectivity for Hg2+over other metal ions including Na+, K+, Ba2+, Mg2+, Ca2+, Fe3+, and Cd2+. The results shown herein have potential implications in the development of new colorimetric sensors for easy and selective detection and monitoring of mercuric ions in aqueous solutions.

  8. Synergistic extraction of transition metal cations from aqueous media by two separated organic phases

    International Nuclear Information System (INIS)

    We have therefore initiated novel approaches to the study of the mechanism of the synergistic extraction of metal ions by means of two separated organic phases, which are brought in contact with the same aqueous phase. The present work is concerned with the extraction of transition metals and actinides ions from nitric acid by chelating agents e.g., HTTA thenoyltrifluoroacetone in a diluent - the first organic phase, and by natural donor, e.g., TBP, tri-butyl phosphate in a diluent the second organic phase. The adduct formation was studied by means of spectrochemical and radiochemical methods. In the first approach the aqueous phase was attacked with both organic phases simultanously (the static or parallel extraction). In this method organic phase are separated one from the other. It was shown that even in the absence of mixing, synergism is observed under this experimental conditions. The results indicate, that adduct formation occurs in both organic phases. Nevertheless the enhanchment of extraction in the TBP phase is by far greater than that in the HTTA containing phase. This approach has one disadvatage, viz., the experiments are very time consuming, a typical experiment requiring over 10 days. In order to overcome this difficulty, the following experiments were carried out: the aqueous phase were first shaken with diluent containing an anionic ligand and the phases were allowed to separate. Then the aqueous solution were shaken with diluent containing a netural donor and the phase again were allowed to separate. The concentration of the metal ions in all the phases were determined. The experiments were repeated with an other diluent replacing the first diluent in one or both organic phases. In this way eight sequences of experiments were carried out for each concentration set chosen. The results thus point out that this experimental approach open new possibilities to investigate the mechanism and the kinetics of synergistic extraction processes. (author) the

  9. Basic Ionic Liquid: A Reusable Catalyst for Knoevenagel Condensation in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An efficient, environmentally friendly procedure was developed for the condensation of aldehydes/ketones and activated methylene compounds with basic ionic liquid as thecatalyst in water. This basic ionic liquid catalyst has a very high activity for Knoevenagel condensation to give the corresponding products in 70% -97% isolated yields under mild conditions. The basic ionic liquid catalyst in aqueous system can be reused for six times without any significant loss of activity.

  10. SINGLE AND DOUBLE IMPRINTED POLYMER FOR SELECTIVE RECOGNITION OF Cd(II) IONS IN AQUEOUS MEDIA

    OpenAIRE

    Ebru Birlik ÖZKÜTÜK; Elif ÖZALP; Gülgün İŞLER

    2010-01-01

    In this paper, we have reported the synthesis of a new single and double-imprinted polymeric material for the separation of Cd(II) ions in aqueous solutions. Chitosan has choosen as the Cd(II) metal complexing big polymer for single and double imprinted polymers. In the synthesis of single imprinted polymer, Cd(II)-complexed chitosan has crosslinked by epichlorohydrin. In the synthesis of double imprinted polymer, Cd(II)-complexed chitosan was reacted with 3-mercaptopropyl-trimethoxysilane. ...

  11. Nanoscopic surfactant behavior of the porin MspA in aqueous media

    OpenAIRE

    Perera, Ayomi S; Hongwang Wang; Tej B. Shrestha; Deryl L Troyer; Stefan H. Bossmann

    2013-01-01

    The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant. The extreme thermostability of MspA allows these investigations to be carried out at temperatures as high as 343 K, at which most other proteins would ...

  12. Stability of mineral matter in aqueous media of the Chernobyl Unit-4 Shelter: Thermodynamic evaluation

    International Nuclear Information System (INIS)

    A special geochemical environment exists within the Shelter (Sarcophagus) erected in 1986 over the destroyed Unit-4 of Chernobyl nuclear power plant (NPP). Based upon the available in situ and compositional data, thermodynamic models of solid-aqueous interactions were developed to clarify the leaching behavior of various materials within the Shelter. The Selektor-A code, based on a convex programming approach to Gibbs free energy minimization, was used for the calculations. A built-in flexible hybrid thermodynamic database for the system Na-K-Ca-Mg-Cl-S-N-H-O-Si-P-Fe-Al-Sr-Cs was extended with the critically selected and matched parameters for aqueous species and solid phases in the U-Zr-Si-O-H subsystem, secondary U-minerals, mineral phases of fully hydrated Portland cements and U-bearing zircons. Modeling results show that the Shelter Waters can selectively leach a significant quantity of U and Si from the fuel-containing masses, while Zr, Fe, Ca, Mg and some other components are rather insoluble. Serpentinite, assemblages of fully-hydrated phases of Portland cements, and oxidation products of steel structural elements are estimated to be sufficiently stable in the aqueous environment of the Shelter. Calculations also define some feasible pathways for secondary mineral formation from evaporation of Shelter water solutions and interactions between these waters with the mineral matter inside the Shelter

  13. The use of some local plants for removal of radioactive and trace elements from aqueous media

    International Nuclear Information System (INIS)

    The removal of metal ions from aqueous solutions by biosorption plays an important role in water pollution control. In this study, dried leaves of Barbary, Jew's mallow and poplar, branches of poplar trees and creeping club as biomass for removal of toxic elements (Cd, Pb and U) and some radionuclides (133Ba, 137Cs and 226Ra) from aqueous solution have been evaluated. The results show that all studied plants can be effectively used for removing U and Ba from aqueous solutions, while Pb was removed using branches of poplar trees. In addition, Cd was removed using Barbary, Jew's mallow and branches of poplar trees. The adsorption of U and Cd by leaves of Barbary reached 3.3 mg g-1 and 3.5 mg g-1, respectively. Moreover, the leaves of poplar trees were the best plant for biosorping Pb, its maximum capacity reached a value 1.7 mg g-1. On the other hand, the maximum capacity for studied radionuclide was less than 10-6 mg g-1. Further more, the effect of many factors such as, plant pretreatment, solution temperature, pH, plant particles size and contact time, on biosorption process were performed and the best conditions of biosorption were recognized. The studied plants were used for removing 226Ra and some trace elements from real polluted water. The results show that the method is effective.(author)

  14. Efficient Isomerization of Glucose to Fructose over Zeolites in Consecutive Reactions in Alcohol and Aqueous Media

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Paniagua, Marta; Melero, Juan A; Riisager, Anders

    2013-01-01

    -USY (Si/Al = 6) gave a remarkable 55% yield of fructose after the second reaction step. A main advantage of applying alcohol media and a catalyst that combines Brønsted and Lewis acid sites is that glucose is isomerized to fructose at low temperatures, while direct conversion to industrially important...

  15. Highly selective hydrogenation of phenol and derivatives over a Pd@carbon nitride catalyst in aqueous media.

    Science.gov (United States)

    Wang, Yong; Yao, Jia; Li, Haoran; Su, Dangsheng; Antonietti, Markus

    2011-03-01

    Cyclohexanone is an important intermediate in the manufacture of polyamides in chemical industry, but direct selective hydrogenation of phenol to cyclohexanone under mild conditions is a challenge. We report here a catalyst made of Pd nanoparticles supported on a mesoporous graphitic carbon nitride, Pd@mpg-C(3)N(4), which was shown to be highly active and promoted the selective formation of cyclohexanone under atmospheric pressure of hydrogen in aqueous media without additives. Conversion of 99% and a selectivity higher than 99% were achieved within 2 h at 65 °C. The reaction can be accelerated at higher temperature, but even at room temperature, 99% conversion and 96% selectivity could still be obtained. The generality of the Pd@mpg-C(3)N(4) catalyst for this reaction was demonstrated by selective hydrogenation of other hydroxylated aromatic compounds with similar performance. PMID:21294506

  16. DETERMINATION OF KINETICS OF DEGRADATION AND MOBILITY OF DITHIOCARBAMATES FUNGICIDES IN AQUEOUS MEDIA AND IN MOROCCAN SOIL

    Directory of Open Access Journals (Sweden)

    Said El Antri

    2010-07-01

    Full Text Available Contribution analysis of dithiocarbamates pesticides used on tomatoes treatment has been reported. The study is focused on analysis and determination of some dithiocarbamates like, Maneb, Mancozeb, Zineb and Propineb, in order to achieve accurate impact of theses pesticides on water and soil. Analysis method is based on decomposition of dithiocarbamate by heating under acidic attack to give carbon disulfide complexed with copper acetate solution in presence of diethanolamine. Complex formed is dosed spectrophotometrically at 435 nm. Degradation kinetic of dithiocarbamate in aqueous media have been realized and proved that dithiocarbamate are degraded by simple air exposition. In the other hand, pH affects also dithiocarbamate degradation by increasing hydroxyl ions to participate for dithiocarbamate instability. Dithiocarbamate mobility on Moroccan soils samples have been realised and don’t have the same degradation mode.

  17. Influence of Operating Conditions on the Removal Cd Ions from Aqueous Media by Adsorption Using Chlamydomonas Reinhardtii

    Institute of Scientific and Technical Information of China (English)

    Jiang Yongbin; Zhu Yi; Ji Hongbing

    2010-01-01

    Chlamydomonas reinhardtii(C.reinhardtii)was used to study adsorption of cadmium(Cd)from aqueous media within various experimental conditions.Results showed that the adsorption process was very fast,with most of the adsorption occurring within30 min of contact time and the equilibrium state was reached in about 60 min.The adsorption ability of the algae increases with the increasing adsorptions sites on cells.Maximum adsorption was observed at the initial Cd concentration of 100 mg/L and pH 6.0.The adsorption was markedly inhibited in the presence of calcium and magnesium ions at 10 mM and the Cd removal efficiency was reduced by 16.54% and 14.99% respectively.This study would be a finding of note with regard to practical wastewater treatment.

  18. Effect of Surface Charge on Surface-Initiated Atom Transfer Radical Polymerization from Cellulose Nanocrystals in Aqueous Media.

    Science.gov (United States)

    Zoppe, Justin O; Xu, Xingyu; Känel, Cindy; Orsolini, Paola; Siqueira, Gilberto; Tingaut, Philippe; Zimmermann, Tanja; Klok, Harm-Anton

    2016-04-11

    Cellulose nanocrystals (CNCs) with different charge densities were utilized to examine the role of electrostatic interactions on surface-initiated atom transfer radical polymerization (SI-ATRP) in aqueous media. To this end, growth of hydrophilic uncharged poly(N,N-dimethylacrylamide) (PDMAM) brushes was monitored by electrophoresis, (1)H NMR spectroscopy, and dynamic light scattering (DLS). Molecular weight and polydispersity of PDMAM brushes was determined by GPC analysis of hydrolytically cleaved polymers. Initiator and polymer brush grafting densities, and thus, initiator efficiencies were derived from elemental analysis. Higher initiator efficiency of polymer brush growth was observed for CNCs with higher anionic surface sulfate half-ester group density, but at the expense of high polydispersity caused by inefficient deactivation. PDMAM grafts with number-average molecular weights up to 530 kDa and polydispersity indices Cu-mediated SI-CRP are analogous to those conducted in solution. PMID:26901869

  19. A novel double-layer molecularly imprinted polymer film based surface plasmon resonance for determination of testosterone in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yuan; Jing, Lijing; Ding, Yonghong; Wei, Tianxin, E-mail: txwei@bit.edu.cn

    2015-07-01

    Highlights: • The in-situ photo-grafting polymerization method was used to prepare the polymer film. • The synthesized MIF was layer stucture film. • The MIF exhibited good imprinting effect and highly selectivity. - Abstract: This work aimed to prepare a novel double-layer structure molecularly imprinted polymer film (MIF) on the surface plasmon resonance (SPR) sensor chips for detection of testosterone in aqueous media. The film was synthesized by in-situ UV photo polymerization. Firstly, the modification of gold surface of SPR chip was performed by 1-dodecanethiol. Then double-layer MIF was generated on the 1-dodecanethiol modified gold surface. The non-modified and imprinted surfaces were characterized by atomic force microscopy (AFM), fourier transform infrared (FTIR) spectroscopy and contact angle measurements. Analysis of SPR spectroscopy showed that the imprinted sensing film displayed good selectivity for testosterone compared to other analogues and the non-imprinted polymer film (NIF). Within the concentrations range of 1 × 10{sup −12}–1 × 10{sup −8} mol/L, the coupling angle changes of SPR were linear with the negative logarithm of testosterone concentrations (R{sup 2} = 0.993). Based on a signal/noise ratio of three, the detection limit was estimated to be 10{sup −12} mol/L. Finally, the developed MIF was successfully applied to the seawater detection of testosterone. The results in the experiments suggested that a combination of SPR sensing with MIF was a promising alternative method for detection of testosterone in aqueous media.

  20. A novel double-layer molecularly imprinted polymer film based surface plasmon resonance for determination of testosterone in aqueous media

    International Nuclear Information System (INIS)

    Highlights: • The in-situ photo-grafting polymerization method was used to prepare the polymer film. • The synthesized MIF was layer stucture film. • The MIF exhibited good imprinting effect and highly selectivity. - Abstract: This work aimed to prepare a novel double-layer structure molecularly imprinted polymer film (MIF) on the surface plasmon resonance (SPR) sensor chips for detection of testosterone in aqueous media. The film was synthesized by in-situ UV photo polymerization. Firstly, the modification of gold surface of SPR chip was performed by 1-dodecanethiol. Then double-layer MIF was generated on the 1-dodecanethiol modified gold surface. The non-modified and imprinted surfaces were characterized by atomic force microscopy (AFM), fourier transform infrared (FTIR) spectroscopy and contact angle measurements. Analysis of SPR spectroscopy showed that the imprinted sensing film displayed good selectivity for testosterone compared to other analogues and the non-imprinted polymer film (NIF). Within the concentrations range of 1 × 10−12–1 × 10−8 mol/L, the coupling angle changes of SPR were linear with the negative logarithm of testosterone concentrations (R2 = 0.993). Based on a signal/noise ratio of three, the detection limit was estimated to be 10−12 mol/L. Finally, the developed MIF was successfully applied to the seawater detection of testosterone. The results in the experiments suggested that a combination of SPR sensing with MIF was a promising alternative method for detection of testosterone in aqueous media

  1. A water-soluble ruthenium glycosylated porphyrin catalyst for carbenoid transfer reactions in aqueous media with applications in bioconjugation reactions.

    Science.gov (United States)

    Ho, Chi-Ming; Zhang, Jun-Long; Zhou, Cong-Ying; Chan, On-Yee; Yan, Jessie Jing; Zhang, Fu-Yi; Huang, Jie-Sheng; Che, Chi-Ming

    2010-02-17

    Water-soluble [Ru(II)(4-Glc-TPP)(CO)] (1, 4-Glc-TPP = meso-tetrakis(4-(beta-D-glucosyl)phenyl)porphyrinato dianion) is an active catalyst for the following carbenoid transfer reactions in aqueous media with good selectivities and up to 100% conversions: intermolecular cyclopropanation of styrenes (up to 76% yield), intramolecular cyclopropanation of an allylic diazoacetate (68% yield), intramolecular ammonium/sulfonium ylide formation/[2,3]-sigmatroptic rearrangement reactions (up to 91% yield), and intermolecular carbenoid insertion into N-H bonds of primary arylamines (up to 83% yield). This ruthenium glycosylated porphyrin complex can selectively catalyze alkylation of the N-terminus of peptides (8 examples) and mediate N-terminal modification of proteins (four examples) using a fluorescent-tethered diazo compound (15). A fluorescent group was conjugated to ubiquitin via 1-catalyzed alkene cyclopropanation with 15 in aqueous solution in two steps: (1) incorporation of an alkenic group by the reaction of N-hydroxysuccinimide ester 19 with ubiquitin and (2) cyclopropanation of the alkene-tethered Lys(6) ubiquitin (23) with the fluorescent-labeled diazoacetate 15 in the presence of a catalytic amount of 1. The corresponding cyclopropanation product (24) was obtained with approximately 55% conversion based on MALDI-TOF mass spectrometry. The products 23, 24, and the N-terminal modified peptides and proteins were characterized by LC-MS/MS and/or SDS-PAGE analyses. PMID:20088517

  2. Phosphotungstic Acid Catalyzed One-Pot Synthesis of 2-amino-3,5-dicarbonitrile-6-thio-pyridines in Aqueous Media

    International Nuclear Information System (INIS)

    In this study, we report the one-pot synthesis of 2-amino-3,5-dicarbonitrile-6-thio-pyridines with benzaldehyde, malononitrile, and thiophenol by using phosphotungstic acid as an efficient catalyst to aqueous media. This method has the advantages of easy separation, high storage stability, and environmental friendliness. (author)

  3. Application of titania-silica microspheres for the sorption of Pu (IV) from aqueous media

    International Nuclear Information System (INIS)

    Porous titania-silica ion exchange material in the form of spherical particles has been prepared using internal gelation method. An anionic surfactant, cetrimide was added in the feed broth containing titanium oxychloride and sodium silicate to make the exchanger porous. The distribution ratio of Pu (IV) between titania-silica microspheres and aqueous carbonate medium has been determined. Strong sorption of plutonium from carbonate and bicarbonate medium indicates the feasibility of using this exchanger for removal of plutonium from carbonate waste solutions. (author)

  4. Imidazoles: Effective Catalysts for Baylis-Hillman Reaction in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    LUO San-Zhong; WANG Peng G.; CHENG Jin-Pei

    2003-01-01

    @@ β-Substituted enones have been considered less reactive in Baylis-Hillman reaction. The reaction of cyclic enones is sluggish or does not occur at all under traditional conditions. Various catalysts have been developed to pro mote the reaction of cyclic enones but with limited success. In previous study, we found that imidazole can catalyze the Baylis-Hillman reaction involving cyclic enones in aqueous THF solution.[1] In our continued efforts, we screened a variety of imidazoles to develop superior catalyst, and we found that the reaction could be greatly accelerated by adjusting the pH value of the water solution.

  5. Azoles: Effective Catalysts for Baylis-Hillman Reaction in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    LUO San-Zhong; WANG Peng G.; CHENG Jin-Pei

    2003-01-01

    @@ β-Substituted enones have been considered less reactive in Baylis-Hillman reaction. The reaction of cyclic enones is sluggish or does not occur at all under traditional conditions. Various catalysts have been developed to pro mote the reaction of cyclic enones but with limited success. In previous study, we found that imidazole can catalyze the Baylis-Hillman reaction involving cyclic enones in aqueous THF solution. [1] In our continued efforts, a variety of azole compounds were examined in Baylis-Hillman reaction. We found that the azoles act as effective catalysts in properly adjusted water solution.

  6. Disposal of heavy metal cations in aqueous media by adsorption on coal to Ghazni

    Directory of Open Access Journals (Sweden)

    О.М. Заславський

    2008-03-01

    Full Text Available  Adsorption of Pb and Cu cations and their mixture on the surface of modified and non-modified anti-gas coal trough different time intervals have been studied. The maximum adsorption capacity of coal relative to each cations have been determined. Absence  of concurrence between cations of Pb and Cu during adsorption from mixture is explained by difference of  types of their interaction with coal surface. The high effectiveness and perspectivities of application of anti-gas coal for neutralization of heavy metal cations in aqueous solution was shown.

  7. Multifunctional modification of wool using an enzymatic process in aqueous-organic media.

    Science.gov (United States)

    Hossain, Kh M Gaffar; González, María Díaz; Lozano, Guillem Rocasalbas; Tzanov, Tzanko

    2009-04-20

    An enzymatic method using laccases for grafting the water insoluble phenolic compound lauryl gallate on wool fabric was developed. To find the compromise conditions at which the substrate is soluble while the enzyme remains active, the reaction was carried out in an 80/20 (v/v, %) aqueous-ethanol mixture, where the enzyme retains 75-80% of its activity. The enzymatic coating of wool with lauryl gallate provided in a one-step process a multifunctional textile material with antioxidant, antibacterial and water repellent properties. PMID:19428731

  8. Photocatalytic hydrogen evolution with platinum loaded cadmium-iron-sulfide mixed crystal powders in aqueous media

    International Nuclear Information System (INIS)

    Mixed crystal powders based on Cd, Fe, and S have been synthesized by varying the ratio of CdS and FeS2 in order to find a suitable material useful for the effective conversion of solar energy. Hydrogen gas was evolved only with CdS/Pt by photocatalytic reaction under white light in an aqueous 1 M sodium sulfite solution. From electrochemical studies of semiconductor electrodes, it was shown that the onset potential shifted to the positive direction and that the bandgap energy also decreased as the molar ratio of Fe increased. A hydrogen evolution mechanism in terms of the conduction band potential and hydrogen evolution potential is proposed

  9. Polarographic studies about indium (III) behaviour in aqueous media of sodium azide

    International Nuclear Information System (INIS)

    The present study shows some polarographic behavior of indium (III) in azide media that is close those observed in a thiocyanate solution. The presence of azide ligand decreases the overpotential in the discharge of indium whose catalytic character can be explained by formation of an azide bridge between electrode and indium (III) increasing the speed of electron transfer. The discharge of indium in azide media is diffusion controlled. As the azide concentration is increased the half wave potential displaces in the cathodic direction. This displacement is due to complex formation. The number of electrons, n, involved in the total process was estimates by the reversible polarographic equation to be 2,7. The potentiostatic coulometry of indium in azide/hydrazoic acid buffer showed a catalytic process where the chemistry regeneration was performed by reaction of hydrazoic acid and indium amalgam. The electrochemistry evidence was the constancy of current as the electrolysis proceeded. The chemistry aspect was the presence of ammonium cation in electrolysed solution. The catalytic process with chemistry regeneration and the formation of a bridge by azide could explain the higher value of current in azide media compared to perchlorate solution. (author)

  10. Removal of beta-blockers from aqueous media by adsorption onto graphene oxide.

    Science.gov (United States)

    Kyzas, George Z; Koltsakidou, Anastasia; Nanaki, Stavroula G; Bikiaris, Dimitrios N; Lambropoulou, Dimitra A

    2015-12-15

    The aim of the present study is the evaluation of graphene oxide (GhO) as adsorbent material for the removal of beta-blockers (pharmaceutical compounds) in aqueous solutions. The composition and morphology of prepared materials were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Atenolol (ATL) and propranolol (PRO) were used as model drug molecules and their behavior were investigated in terms of GhO dosage, contact time, temperature and pH. Adsorption mechanisms were proposed and the pH-effect curves after adsorption were discussed. The kinetic behavior of GhO-drugs system was analyzed after fitting to pseudo-first and -second order equations. The adsorption equilibrium data were fitted to Langmuir, Freundlich and Langmuir-Freundlich model calculating the maximum adsorption capacity (67 and 116 mg/g for PRO and ATL (25 °C), respectively). The temperature effect on adsorption was tested carrying out the equilibrium adsorption experiments at three different temperatures (25, 45, 65 °C). Then, the thermodynamic parameters of enthalpy, free energy and entropy were calculated. Finally, the desorption of drugs from GhO was evaluated by using both aqueous eluants (pH2-10) and organic solvents. PMID:26282775

  11. Economic Globalization and a Nuclear Renaissance

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Thomas W.; Johnson, Wayne L.; Parker, Brian M.

    2001-10-22

    The phenomenon of globalization has become increasingly well recognized, documented, and analyzed in the last several years. Globalization, the integration of markets and intra-firm competition on a worldwide basis, involves complex behavioral and mindset changes within a firm that facilitate global competition. The changes revolve around efficient information flow and rapid deployment of technology. The objective of this report is to examine the probable characteristics of a global nuclear renaissance and its broad implications for industry structure and export control relative to nuclear technology. The question of how a modern renaissance would affect the trend toward globalization of the nuclear industry is addressed.

  12. Economic Globalization and a Nuclear Renaissance

    International Nuclear Information System (INIS)

    The phenomenon of globalization has become increasingly well recognized, documented, and analyzed in the last several years. Globalization, the integration of markets and intra-firm competition on a worldwide basis, involves complex behavioral and mindset changes within a firm that facilitate global competition. The changes revolve around efficient information flow and rapid deployment of technology. The objective of this report is to examine the probable characteristics of a global nuclear renaissance and its broad implications for industry structure and export control relative to nuclear technology. The question of how a modern renaissance would affect the trend toward globalization of the nuclear industry is addressed

  13. Silica coating of luminescent quantum dots prepared in aqueous media for cellular labeling

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yunfei; Li, Yan, E-mail: yli@ecust.edu.cn; Zhong, Xinhua, E-mail: zhongxh@ecust.edu.cn

    2014-12-15

    Graphical abstract: A facile route based on modified Stöber method was used for the synthesis of silica coated QDs (QD@SiO{sub 2}) starting from aqueously prepared CdTe/CdS QDs. The resultant QD@SiO{sub 2} exhibited a significant increase in emission efficiency compared with that of the initial QDs, along with a small size (∼5 nm in diameter), great stability and low cytotoxicity, which makes it a good candidate as robust biomarker. - Highlights: • We present a facile modified Stöber method to prepare highly luminescent QD@SiO{sub 2}. • The PL efficiency of QDs increases significantly after silica coating. • QD@SiO{sub 2} exhibits small size (∼5 nm) and great dispersibility in aqueous solution. • QD@SiO{sub 2} presents extraordinary photo and colloidal stability. • The silica shell eliminates QD cytotoxicity, providing the access of bioconjugation. - Abstract: Silica coating is an effective approach for rendering luminescent quantum dots (QDs) with water dispersibility and biocompatibility. However, it is still challenging to prepare silica-coated QDs (QD@SiO{sub 2}) with high emission efficiency, small size and great stability in favor for bioapplication. Herein, we reported a modified Stöber method for silica coating of aqueously-prepared CdTe/CdS QDs. With the coexistence of Cd{sup 2+} and thioglycolic acid (TGA), a thin silica shell was formed around QDs by the hydrolysis of tetraethyl orthosilicate (TEOS). The resultant QD@SiO{sub 2} with a small size (∼5 nm in diameter) exhibits significantly higher emission efficiencies than that of the initial QDs. Also, QD@SiO{sub 2} has extraordinary photo and colloidal stability (pH range of 5–13, 4.0 M NaCl solution). Protected by the silica shell, the cytotoxicity of QDs could be reduced. Moreover, the QD@SiO{sub 2} conjugated with folic acid (FA) presents high specific binding toward receptor-positive HeLa cells over receptor-negative A549 cells.

  14. Silica coating of luminescent quantum dots prepared in aqueous media for cellular labeling

    International Nuclear Information System (INIS)

    Graphical abstract: A facile route based on modified Stöber method was used for the synthesis of silica coated QDs (QD@SiO2) starting from aqueously prepared CdTe/CdS QDs. The resultant QD@SiO2 exhibited a significant increase in emission efficiency compared with that of the initial QDs, along with a small size (∼5 nm in diameter), great stability and low cytotoxicity, which makes it a good candidate as robust biomarker. - Highlights: • We present a facile modified Stöber method to prepare highly luminescent QD@SiO2. • The PL efficiency of QDs increases significantly after silica coating. • QD@SiO2 exhibits small size (∼5 nm) and great dispersibility in aqueous solution. • QD@SiO2 presents extraordinary photo and colloidal stability. • The silica shell eliminates QD cytotoxicity, providing the access of bioconjugation. - Abstract: Silica coating is an effective approach for rendering luminescent quantum dots (QDs) with water dispersibility and biocompatibility. However, it is still challenging to prepare silica-coated QDs (QD@SiO2) with high emission efficiency, small size and great stability in favor for bioapplication. Herein, we reported a modified Stöber method for silica coating of aqueously-prepared CdTe/CdS QDs. With the coexistence of Cd2+ and thioglycolic acid (TGA), a thin silica shell was formed around QDs by the hydrolysis of tetraethyl orthosilicate (TEOS). The resultant QD@SiO2 with a small size (∼5 nm in diameter) exhibits significantly higher emission efficiencies than that of the initial QDs. Also, QD@SiO2 has extraordinary photo and colloidal stability (pH range of 5–13, 4.0 M NaCl solution). Protected by the silica shell, the cytotoxicity of QDs could be reduced. Moreover, the QD@SiO2 conjugated with folic acid (FA) presents high specific binding toward receptor-positive HeLa cells over receptor-negative A549 cells

  15. Efficient Isomerization of Glucose to Fructose over Zeolites in Consecutive Reactions in Alcohol and Aqueous Media

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Paniagua, Marta; Melero, Juan A; Riisager, Anders

    2013-01-01

    glucose isomerization to fructose and subsequent reaction with methanol to form methyl fructoside (step 1), followed by hydrolysis to re-form fructose after water addition (step 2). NMR analysis with (13)C-labeled sugars confirmed this reaction pathway. Conversion of glucose for 1 h at 120 °C with H......-USY (Si/Al = 6) gave a remarkable 55% yield of fructose after the second reaction step. A main advantage of applying alcohol media and a catalyst that combines Brønsted and Lewis acid sites is that glucose is isomerized to fructose at low temperatures, while direct conversion to industrially important...

  16. Study of charge compensation during the redox process of self-doped polyaniline in aqueous media

    Directory of Open Access Journals (Sweden)

    Varela Hamilton

    2000-01-01

    Full Text Available One of the most important problems associated with use of polyaniline as a cathode material in rechargeable lithium batteries is related to energy density degradation due to the predomination of anion participation in the charge compensation process. This work describes the synthesis of a self-doped polyaniline, poly-(aniline-co-N-propanesulfonic acid-aniline, and evaluates its properties in aqueous acid solutions, with special attention to the increase of proton participation in the electroneutralization mechanism. The characterization was carried out using elemental analysis, FTIR and UV-vis spectroscopies. Electrochemical properties were investigated with the electrochemical quartz crystal microbalance and cyclic voltammetry. The results obtained show that proton participation was increased for the redox process of poly-(aniline-co- N-propanesulfonic-acid-aniline in relation to polyaniline.

  17. Organo/Zn-Al LDH Nanocomposites for Cationic Dye Removal from Aqueous Media.

    Science.gov (United States)

    Starukh, G; Rozovik, O; Oranska, O

    2016-12-01

    Cationic dye sorption by Zn-Al-layered double hydroxides (LDHs) modified with anionic surfactants was examined using methylene blue (MB) dye as a compound model in aqueous solutions. The modification of Zn-Al LDHs was performed by reconstruction method using dodecyl sulfate anion (DS) solutions. DS contained Zn-Al LDHs were characterized by XRD, FTIR, thermogravimetric, and SEM analysis. The reconstructed organo/Zn-Al LDHs comprise the crystalline phases (DS-intercalated LDHs, hydrotalcite), and the amorphous phase. The intercalation of DS ions into the interlayer galleries and DS adsorption on the surface of the LDHs occurred causing the MB adsorption on the external and its sorption in the internal surfaces of modified LDHs. The presence of DS greatly increased the affinity of organo/Zn-Al LDHs for MB due to hydrophobic interactions between the surfactants and the dye molecules. The optical properties of sorbed MB were studied. PMID:27119156

  18. Nanoscopic surfactant behavior of the porin MspA in aqueous media

    Directory of Open Access Journals (Sweden)

    Ayomi S. Perera

    2013-04-01

    Full Text Available The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant. The extreme thermostability of MspA allows these investigations to be carried out at temperatures as high as 343 K, at which most other proteins would quickly denature. The principles of vesicle formation of MspA as a function of temperature and the underlying thermodynamic factors are discussed here. The results obtained provide crucial evidence in support of the hypothesis that, during vesicle formation, nanoscopic surfactant molecules, such as MspA, deviate from the principles underlined in classical surface chemistry.

  19. Organo/Zn-Al LDH Nanocomposites for Cationic Dye Removal from Aqueous Media

    Science.gov (United States)

    Starukh, G.; Rozovik, O.; Oranska, O.

    2016-04-01

    Cationic dye sorption by Zn-Al-layered double hydroxides (LDHs) modified with anionic surfactants was examined using methylene blue (MB) dye as a compound model in aqueous solutions. The modification of Zn-Al LDHs was performed by reconstruction method using dodecyl sulfate anion (DS) solutions. DS contained Zn-Al LDHs were characterized by XRD, FTIR, thermogravimetric, and SEM analysis. The reconstructed organo/Zn-Al LDHs comprise the crystalline phases (DS-intercalated LDHs, hydrotalcite), and the amorphous phase. The intercalation of DS ions into the interlayer galleries and DS adsorption on the surface of the LDHs occurred causing the MB adsorption on the external and its sorption in the internal surfaces of modified LDHs. The presence of DS greatly increased the affinity of organo/Zn-Al LDHs for MB due to hydrophobic interactions between the surfactants and the dye molecules. The optical properties of sorbed MB were studied.

  20. Nanoscopic surfactant behavior of the porin MspA in aqueous media.

    Science.gov (United States)

    Perera, Ayomi S; Wang, Hongwang; Shrestha, Tej B; Troyer, Deryl L; Bossmann, Stefan H

    2013-01-01

    The mycobacterial porin MspA is one of the most stable channel proteins known to date. MspA forms vesicles at low concentrations in aqueous buffers. Evidence from dynamic light scattering, transmission electron microscopy and zeta-potential measurements by electrophoretic light scattering indicate that MspA behaves like a nanoscale surfactant. The extreme thermostability of MspA allows these investigations to be carried out at temperatures as high as 343 K, at which most other proteins would quickly denature. The principles of vesicle formation of MspA as a function of temperature and the underlying thermodynamic factors are discussed here. The results obtained provide crucial evidence in support of the hypothesis that, during vesicle formation, nanoscopic surfactant molecules, such as MspA, deviate from the principles underlined in classical surface chemistry. PMID:23766950

  1. Removal of murexide (dye) from aqueous media using rice husk as an adsorbent

    International Nuclear Information System (INIS)

    The use of low-cost and eco friendly adsorbent was investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. Rice husk was used as an adsorbent for the removal of Murexide from aqueous solutions. The rate of adsorption was investigated under various parameters such as size of adsorbent, contact time of solution with adsorbent, temperature, pH, adsorbent dose and stirring speed for the removal of this dye. Langmuir isotherm was also applied to evaluate maximum adsorption capacity of rice husk for Murexide. On the basis of results obtained, it is proposed that rice husk can be effectively used for the elimination of Murexide from waste water. (author)

  2. Spectroscopic and electrochemical properties of di-2-pyridyl ketone thiosemicarbazone [dpktsc] in non-aqueous media

    Science.gov (United States)

    Bakir, Mohammed; Brown, Ordel

    2011-12-01

    Spectroscopic measurements on non-aqueous solutions of [dpktsc] divulged high sensitivity of [dpktsc] to its surroundings. 1H NMR studies performed on d 6-dmso and d 6-acetone solutions of [dpktsc] disclosed inter-molecular hydrogen bond between the amine proton and the solvent oxygen atom. In non-protophilic solvent (CDCl 3), intra-molecular hydrogen bond between the amide proton and a nitrogen atom of a pyridine ring was elucidated. Electronic absorption measurements done on non-aqueous solutions of [dpktsc] revealed two intra-ligand charge transfer transitions (ILCT) due to n → π * and π → π * of the thione followed by thione to pyridine charge transfer. In protophilic solvents, a shoulder appeared at ˜400 nm along with the ILCT transitions. Spectrophotometric titrations of [dpktsc] with NaBX 4 (X = H or F) and thermo-optical measurements in dmf disclosed that deprotonation of [dpktsc] is not favorable. When stoichiometric amounts of [MCl 2] (M = Zn, Cd or Hg) were added to dmf solutions of [dpktsc], facile conversion of [dpktsc] to its conjugate base [dpktsc-H] - and in situ formation of [MCl 2(κ 3-N,N,S-dpktsc-H] - was observed. Dmf solutions of [dpktsc] are able to detect and determine [MCl 2] in concentrations as low as 1.00 × 10 -12 M. Protophilic solutions (dmf) of [dpktsc] show high affinity to [ZnCl 2], compared to [MCl 2] (M = Cd or Hg). Electrochemical measurements done on dmf solutions of [dpktsc] in the presence and absence of [MCl 2] show reductive decomposition of [dpktsc] in the absence of [MCl 2] and in the presence of [MCl 2] electrochemical signatures consistent with the in situ formation of [MCl 2(κ 3-N,N,S-dpktsc-H)] - were observed.

  3. Nucleophilic addition of amines to the activated ethylene bond in non-aqueous media

    International Nuclear Information System (INIS)

    The kinetics of addition of a number of primary and secondary aliphatic amines to trans-(2-furyl) nitro ethylene (1) has been studied in solvents of various polarities (from acetonitrile, ε 37.5, to heptane, ε 1.89). It has been shown that the reaction is catalysed both by the amine reagent and by tertiary amines. On the basis of analyzing the observed kinetic regularities a stepwise reaction mechanism has been proposed which involves formation of zwitterionic intermediate (3) at the first equilibrium step (k1, K1) which is then converted into the reaction product by means of proton transfer in parallel routes, the non-catalytic one (k2) and that catalysed by the initial (K3) or tertiary (K4) amine. The observed high values of the deuterium isotope effects in the reaction (KH/KD ∼ 2.3 - 8.9) confirm that proton transfer occurs in the rate-limiting step of the reaction (primary kinetic isotope effect). The third order by amine kinetic route is observed in low polar media which is due to participation of amine dimers (R2 NH HNR2) in the reaction. The observed kinetic regularities are compared with those for the nucleophilic aromatic substitution reactions in low-polar media, and the conclusion has been made that the reaction route of the third order by amine proceeds as reversible nucleophilic attack by amine dimer and following base-catalysed transformation of the intermediate into the product. (author)

  4. Solvent extraction of plutonium(IV) by sulphoxides from mixed aqueous-organic media

    International Nuclear Information System (INIS)

    Extraction behaviour of plutonium(IV) from nitric acid media by two long-chain aliphatic sulphoxides, namely, di-hexylsulphoxide and di-n-octylsulphoxide has been investigated in the presence of several water-miscible organic solvents to study their possible synergistic effect on metal ion extraction. Methanol, ethanol, n - and isopropanol, dioxane, acetone as well as acetonitrile were used as the organic components of the mixed (polar) phase. These additives affected the extraction to varying degrees. Thus, extractability of Pu increases 2-3 fold with increasing concentration (upto 20%) of acetonitrile, acetone, methanol and ethanol while it decreases with increasing concentration of n- and isopropanol. At high concentration of the former, the synergism changes into antagonism. Possible reasons for such behaviour are briefly discussed. Among these organic additives, maximum enhancement in the extraction of Pu(IV) was observed in the presence of acetonitrile. The relative increase in extraction was found to be more at lower sulphoxide concentrations. (author)

  5. Simultaneous Extraction and Depolymerization of Fucoidan from Sargassum muticum in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Elena M. Balboa

    2013-11-01

    Full Text Available The biomass components of the invasive seaweed Sargassum muticum were fractionated to allow their separate valorization. S. muticum (Sm and the solid residue remaining after alginate extraction of this seaweed (AESm were processed with hot, compressed water (hydrothermal processing to assess the effects of temperature on fucoidan solubilization. Fucose-containing oligosaccharides were identified as reaction products. Operating under optimal conditions (170 °C, up to 62 and 85 wt% of the dry mass of Sm and AESm were solubilized, respectively. The reaction media were subjected to precipitation, nanofiltration and freeze-drying. The dried products contained 50% and 85% of the fucoidan present in Sm and AESm, respectively; together with other components such as phenolics and inorganic components. The saccharidic fraction, accounting for up to 35% of the dried extracts, contained fucose as the main sugar, and also galactose, xylose, glucose and mannose. The concentrates were characterized for antioxidant activity using the TEAC assay.

  6. Protein imprinting and recognition via forming nanofilms on microbeads surfaces in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan, E-mail: yanlu2001@sohu.com [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China); Yan Changling [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China); Wang Xuejing [Chemistry and Chemical Engineer School, Henna Institute of Science and Technology, Xinxiang 453003 (China); Wang Gongke [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007 (China)

    2009-12-15

    In this paler, we present a technique of forming nanofilms of poly-3-aminophenylboronic acid (pAPBA) on the surfaces of polystyrene (PS) microbeads for proteins (papain and trypsin) in aqueous. Papain was chosen as a model to study the feasibility of the technique and trypsin as an extension. Obtained core-shell microbeads were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET methods. The results show that pAPBA formed nanofilms (60-100 nm in thickness) on the surfaces of PS microbeads. The specific surface area of the papain-imprinted beads was about 180 m{sup 2} g{sup -1} and its pore size was 31 nm. These imprinted microbeads exhibit high recognition specificity and fast mass transfer kinetics. The specificity of these imprinted beads mainly originates from the spatial effect of imprinted sites. Because the protein-imprinted sites were located at, or close to, the surface, the imprinted beads have good site accessibility toward the template molecules. The facility of the imprinting protocol and the high recognition properties of imprinted microbeads make the approach an attractive solution to problems in the field of biotechnology.

  7. Extraction of nitric acid from aqueous media with OφD(iB)CMPO-n-dodecane

    International Nuclear Information System (INIS)

    A study of the extraction characteristics of nitric acid with octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide [OφD(iB)CMPO or, simply, CMPO] was conducted. In the experimental program, CMPO was dissolved in n-dodecane to produce the organic extracting medium. The objectives of the project were to infer extraction stoichiometry and to estimate equilibrium constants for the extraction of nitric acid with the CMPO extractant. Experiments were performed over a limited range of concentrations to avoid conditions favoring formation of a third phase. Aqueous nitric acid concentrations were limited to 0.30 M at 25 C, 1.0 M at 40 C, and 3.0 M at 50 C. The data indicate that CMPO extracts nitric acid with a 1:1 stoichiometry. The value of the equilibrium constant is estimated at 2.66 ± 0.09 at 25 C. The enthalpy of the extraction is estimated to be -5.46 ± 0.46 kcal/mol

  8. Large pore diameter MCM-41 and its application for lead removal from aqueous media.

    Science.gov (United States)

    Idris, Salah A; Davidson, Christine M; McManamon, Colm; Morris, Michael A; Anderson, Peter; Gibson, Lorraine T

    2011-01-30

    A room temperature method to create large pore size and pore volume ordered mesoporous silica (MCM-41) is demonstrated. Template removal was achieved with a microwave digestion procedure using a solution of nitric acid and hydrogen peroxide. The silica product exhibited an ordered hexagonal mesostructure, large pore volume (up to 0.99 cm(3)/g), and large pore size (up to 6.74 nm) indicating its potential as a high capacity adsorbent. Surface modification, to enhance the ability of the material to extract potentially toxic metals (PTMs) from water was performed using different amino- and mercapto-functional groups. This paper reports on the extraction of lead ions from aqueous solution to demonstrate the material's significant improvement in adsorption capacity (up to 1000 μmol g(-1) for lead). Moreover, methods have been developed to regenerate the sorbent allowing 100% recovery of Pb and reuse of the sorbent material in subsequent extractions. The performance of the material was also demonstrated for environmental samples containing relatively high concentrations (ppmv) of mixed metal ions reducing them to lower values (<100 ppbv) indicating that the sorbent may have applicability for environmental remediation of polluted water. PMID:21035253

  9. A selective fluorescent 'turn-on' sensor for recognition of Zn2 + in aqueous media

    Science.gov (United States)

    Ozdemir, Mecit

    2016-05-01

    A new rhodamine-based fluorescent probe 'RhAP' was synthesized and successfully characterized using FT-IR, 13C NMR and 1H NMR spectroscopies, LC-MS/MS spectrometry and elemental analysis. The RhAP, a colorless and non-fluorescent compound, showed a selective fluorescent response and colorimetric change for Zn2 + in HEPES buffer (10 mM, EtOH:water, 2:1, v/v, pH 7.2). Upon the addition of two equivalents of Zn2 + to a solution of RhAP, a nearly 35-fold enhancement of the fluorescence intensity, with an emission maximum at 578 nm, was observed in comparison to the sensor alone under the same experimental conditions. The complex formation between RhAP and Zn2 + was found to have a 1:1 ratio based on calculations obtained from Job's plot and the mole ratio plot methods. The results showed that RhAP can be used as an effective fluorescent probe for selective detecting of Zn2 + in an aqueous medium.

  10. Chromium removal from aqueous media by superparamagnetic starch functionalized maghemite nanoparticles

    Indian Academy of Sciences (India)

    P N Singh; D Tiwary; I Sinha

    2015-11-01

    Superparamagnetic starch functionalized maghemite nanoparticles (SMhNPs) were synthesised by a co-precipitation method via in situ functionalization and used as nano-adsorbents for the removal of Cr(VI) from aqueous waste. The characterization of the prepared nanoparticles was done by XRD, FTIR, TEM and VSM techniques. Adsorption of Cr(VI) on the surface of superparamagnetic starch functionalized maghemite nano-adsorbents was investigated and the removal was higher in acidic pH as compared to that exhibited in basic medium. The adsorption of Cr(VI) by the SMhNPs followed pseudo-second order kinetics and the adsorption isotherm data fits well the Freundlich adsorption isotherm. The F value for Cr(VI) removal by SMhNPs is found to be 24.76 mg.g−1, which is significantly better than the adsorption capacities reported in literature for maghemite nanoparticles. Thermodynamic studies revealed that the adsorption of Cr(VI) onto the superparamagnetic starch functionalized maghemite nano-adsorbents is spontaneous and endothermic in nature.

  11. SINGLE AND DOUBLE IMPRINTED POLYMER FOR SELECTIVE RECOGNITION OF Cd(II IONS IN AQUEOUS MEDIA

    Directory of Open Access Journals (Sweden)

    Ebru Birlik ÖZKÜTÜK

    2010-12-01

    Full Text Available In this paper, we have reported the synthesis of a new single and double-imprinted polymeric material for the separation of Cd(II ions in aqueous solutions. Chitosan has choosen as the Cd(II metal complexing big polymer for single and double imprinted polymers. In the synthesis of single imprinted polymer, Cd(II-complexed chitosan has crosslinked by epichlorohydrin. In the synthesis of double imprinted polymer, Cd(II-complexed chitosan was reacted with 3-mercaptopropyl-trimethoxysilane. Then, the polymeric beads have crosslinked with tetraethoxysilane (TEOS. The imprinted cadmium ions have removed from the polymeric matrix by 0.1M HNO3 (to prepare Cd(II templates. Optimum pH for rebinding of Cd(II on the single and double-imprinted polymers was 7.0. Equilibrium binding time and sorbent capacity have been found as 120 and 60 min, 342 and 172 mg g-1 for single and double imprinted polymers, respectively. In selectivity studies, it has been found that double imprinted results in increased affinity of the material toward Cd(II ion over other competitor metal ions with the same charge. The prepared single and double-imprinted polymers have repeatedly used and regenerated for thirty times without a significant decrease in polymer binding affinities.

  12. Colloidal properties and behaviors of 3 nm primary particles of detonation nanodiamonds in aqueous media.

    Science.gov (United States)

    Mchedlov-Petrossyan, N O; Kamneva, N N; Marynin, A I; Kryshtal, A P; Ōsawa, E

    2015-06-28

    This study was aimed to reveal the principal colloidal properties of the aqueous dispersion of extremely small primary single-crystalline diamond particles in water. Together with the non-diamond layer, the size of the colloidal species is 2.8 ± 0.6 nm as found via DLS of the initial 5.00 wt/vol% hydrosol. Anionic dyes are readily adsorbed on the colloidal species. This is in line with the positive zeta-potential. The critical coagulation concentrations of the 0.19 wt/vol% nanodiamond hydrosol were determined with a set of inorganic electrolytes and anionic surfactants. The data are in line with the Schulze-Hardy rule for "positive" sols. The fulfillment of the lyotropic (Hofmeister) series was also observed for single-charged anions. The abnormal influence of alkali gives evidence of the acidic nature of the positive charge of the nanodiamond species. Application of acid-base indicators allows estimating the value of the interfacial electrical potential of the nanodiamond particles. Upon dilution from 5.00% to 0.01%, the colloidal system under study exhibits unusual changes. The average size increases ca. ten-fold as determined by DLS. The TEM images support this observation. At the same time, the viscosity drops. This phenomenon was explained in terms of the so-called periodic colloidal structures (colloidal crystals) in concentrated solutions. PMID:26035732

  13. Protein imprinting and recognition via forming nanofilms on microbeads surfaces in aqueous media

    International Nuclear Information System (INIS)

    In this paler, we present a technique of forming nanofilms of poly-3-aminophenylboronic acid (pAPBA) on the surfaces of polystyrene (PS) microbeads for proteins (papain and trypsin) in aqueous. Papain was chosen as a model to study the feasibility of the technique and trypsin as an extension. Obtained core-shell microbeads were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET methods. The results show that pAPBA formed nanofilms (60-100 nm in thickness) on the surfaces of PS microbeads. The specific surface area of the papain-imprinted beads was about 180 m2 g-1 and its pore size was 31 nm. These imprinted microbeads exhibit high recognition specificity and fast mass transfer kinetics. The specificity of these imprinted beads mainly originates from the spatial effect of imprinted sites. Because the protein-imprinted sites were located at, or close to, the surface, the imprinted beads have good site accessibility toward the template molecules. The facility of the imprinting protocol and the high recognition properties of imprinted microbeads make the approach an attractive solution to problems in the field of biotechnology.

  14. Synthesis of assembled ZnO structures by precipitation method in aqueous media

    International Nuclear Information System (INIS)

    In this work, arrays of submicron ZnO structures were successfully synthesized using a one-step aqueous precipitation method. Snowflake-like and flower-like morphologies were obtained by changing the reaction temperature. X-ray diffraction (XRD) patterns indicated that the ZnO arrays have a wurtzite crystal structure. A possible growth mechanism based on the analysis done by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and high-angle annular dark field (HAADF) is proposed. Our findings suggest that the growth mechanism of the ZnO arrays is by self-aggregation, and that such an oriented aggregation is enhanced by increasing the reaction temperature. The results also revealed that the aggregation process introduces several structural defects such as differences in mass distribution and crystalline structure. In order to study the surface chemical composition the samples were also characterized by XPS. The results showed the presence of Zn(OH)2 and absorbed carbon species on the ZnO surface. In addition, the photoluminescence characterization showed that on UV excitation (λ = 360 nm) all samples present the characteristic UV emission centered at 390 nm, and for the sample synthesized at 60 deg. C, a visible emission was also observed

  15. A Simple Hydrophilic Palladium(II Complex as a Highly Efficient Catalyst for Room Temperature Aerobic Suzuki Coupling Reactions in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Mengping Guo

    2014-05-01

    Full Text Available A study on room temperature Suzuki cross-coupling in an aqueous medium was carried out using a simple hydrophilic palladium (II complex, trans-PdCl2(NH2CH2COOH2 as catalyst in the presence of K2CO3 in air. This approach with a comparatively inexpensive and hydrophilic catalyst, mild reaction condition and aqueous media exhibits excellent catalytic activity towards the Suzuki coupling of aryl bromides and arylboronic acids, and good yields were obtained in the Suzuki coupling of activated aryl chlorides.

  16. Extremophile mediated hydrogen production for hydrogenation of substrates in aqueous media

    Science.gov (United States)

    Anjom, Mouzhgun

    Catalytic hydrogenation reactions are pervasive throughout our economy, from production of margarine as food, liquid fuels for transportation and chiral drugs such as L-DOPA. H2 production from non-fossil fuel feedstocks is highly desirable for transition to the "Hydrogen Economy". Also, the rates of hydrogenation reactions that involve a substrate, H 2 gas and a catalyst are often limited by the solubility of H2 in solvent. The present research thus envisioned designing water-soluble catalysts that could effectively utilize biologically produced H2 in a coupled system to hydrogenate substrates in homogeneous mode (two-phase system). Biological production of H2 as an end product or byproduct of the metabolism of organisms that operate under strict anaerobic conditions has been proposed. However, contrary to what was previously observed, Thermotoga neapolitana, belonging to the order of Thermotogales efficiently produces H2 gas under microaerobic conditions (Van Ooteghem et al. 2004). For H2 production by T. neapolitana in the bacterial growth medium (DSM 5068) at an optimum temperature of 70 C, our results in batch mode show that: (1) H2 was produced from glucose though with 16% efficiency, the rest goes to biomass production, (2) H2 gas was produced even when the cultures were inoculated under microaerobic conditions (up to 8% (v/v) O2) suggesting a protective mechanism for one or more [Fe-Fe] hydrogenases in T. neapolitana, (3) H2 production was pH dependent but addition of simple, non-toxic physiological buffering additives such as Methylene succinic acid increased H2 production and (4) H2 production rate varied linearly in the 100--6800 kPa pressure range. We then screened various water-soluble metal catalysts in batch mode and selected the RhCl3.3H2O/TPPTS (TPPTS is a water-soluble ligand) system that achieved 86% hydrogenation of Methylene succinic acid (an olefin) in an aqueous medium pressurized with preformed H2. When water was replaced with the DSM 5068

  17. Removal and Recovery of Lead from Aqueous Solution by Low Cost Media

    Directory of Open Access Journals (Sweden)

    L. Pappalardo

    2011-01-01

    Full Text Available Problem statement: To remove Pb(II from wastewater using local UAE sand and then to recover the removed Pb(II. Approach: Removal efficiency of Pb(II from wastewater was investigated using white, yellow and red United Arab Emirates sand with pore sizes 3 intervals while continuously injecting 300 ppm Pb(II solution into the column. Pb(II concentrations were determined using inductively coupled plasma- atomic emission spectrometer (ICP-AES. Measurements were carried out until saturation of the column by Pb(II was attained. Recovery efficiency of Pb(II was initially investigated using distilled water, 0.100 mol dm−3 HNO3 and pH 8.0 aqueous solutions. Recovery via chelation with Ethylenediaminetetraacetic Acid (EDTA was then attempted. Results: Batch experiments showed that yellow sand was more efficient than either white or red sand in removing Pb(II, with a maximum removal capacity of 0.030 kg Pb(II per kg yellow sand. Accordingly, yellow sand was selected for column filtration experiments. In column filtration, the removal capacity rose to a maximum of 0.086 kg Pb(II per kg sand. When sand containing removed Pb(II in batch experiments was equilibrated overnight with EDTA solutions in stoichiometric excess, 86.6% recovery was observed. By comparison, recovery using EDTA in column filtration was 94.7%. Recovery by injection of either water or 0.100 mol dm−3 HNO3 solution was either negligible or much lower than that obtained with EDTA. Conclusion: Column filtration using UAE yellow sand is an efficient and inexpensive method to remove Pb(II from wastewaters. Pb(II can be efficiently recovered from yellow sand columns by chelation with EDTA.

  18. Surface degradation behaviour of sodium borophosphate glass in aqueous media: Some studies

    Indian Academy of Sciences (India)

    K V Shah; M Goswami; S Manikandan; V K Shrikhande; G P Kothiyal

    2009-06-01

    The degradation behaviour of phosphate glass with nominal composition, 40Na2O–10BaO–B2O3–(50–)P2O5, where 0 ≤ ≤ 20 mol%, was studied in water, HCl and NaOH solutions at room temperature to 60°C for different periods extending up to 300 h. These glasses were synthesized by conventional melt-quench technique. Dissolution rates were found to increase with B2O3 content in the glass. The dissolution rates for the glass having 10 mol% B2O3 were found to be 0.002 g/cm2 and 0.015 g/cm2 in distilled water and 5% NaOH solution, respectively, at room temperature after 225 h of total immersion period, whereas it increased considerably to 0.32 g/cm2 in 5% NaOH at 60°C after 225 h. However, glass samples with = 15 and 20 mol% B2O3 were dissolved in 5% HCl solution after 5 h immersion. The degradation behaviour has been correlated with the structural features present in the glass. The optical microscopy of the corroded surface revealed that the corrosion mechanism were different in acid and alkali media.

  19. Dithizone as novel and efficient chromogenic probe for cyanide detection in aqueous media through nucleophilic addition into diazenylthione moiety

    Science.gov (United States)

    Tavallali, Hossein; Deilamy-Rad, Gohar; Parhami, Abolfath; Kiyani, Sajede

    2014-03-01

    A new selective chemodosimeter probe was developed by the introduction of dithizone (DTZ) as a simple and available dye for detection of cyanide in aqueous media which enables recognition of cyanide over other competing anions such as acetate, dihydrogen phosphate, fluoride and benzoate through covalent bonding. The sensing properties of DTZ were investigated in DMSO/H2O (1:9) and have demonstrated a very high selectivity toward the cyanide anions. A reasonable recognition mechanism was suggested using UV-Vis, 1H NMR and FTIR spectroscopy techniques. Time dependent density function theory (TDDFT) computations of UV-Vis excitation for DTZ2-CN adduct agreed well with our experimental findings. The detection limit of the new chromogenic probe was measured to be 0.48 μmol L-1 which is much lower than most recently reported chromogenic probes for cyanide determination. The analytical utility of the method for the analysis of cyanide ions in electroplating wastewater (EPWW), human serum, tap and mineral water samples was demonstrated and the results were compared successfully with the conventional reference method. The short time response and the detection by the naked eye make the method available for the detection and quantitative determination of cyanide in a variety of real samples.

  20. Nanocomposite-based rapid, visual, and selective luminescence turn-on assay for Hg2+ sensing in aqueous media.

    Science.gov (United States)

    Cui, Jiabin; An, Mingyue; Wang, Leyu

    2013-10-15

    Composite nanospheres containing dithizone, luminescent LaVO4:Eu(3+) nanoparticles (NPs), and amphiphilic polymer have been composed for the rapid, selective, and visual luminescence turn-on detection of mercury ions (Hg(2+)) in water. Due to the absorption of dithizone, the strong red luminescence of LaVO4:Eu(3+) NPs encapsulated in nanospheres was quenched noticeably. As a result, these as-prepared nanocomposites (NCs) demonstrate very weak red luminescence. However, in the presence of Hg(2+), the red luminescence of nanocomposites was turned on dramatically, which can be attributed to the strong binding of mercury (II) ions by dithizone and forming a complex without absorption in the red emission range. Meanwhile, other cations have no influence on the detection of Hg(2+), suggesting a good selectivity for Hg(2+) sensing. Due to the high photostability and chemical stability of the nanocomposites, operation simplicity, low cost, and good selectivity, this newly developed method is highly desirable for field assay of Hg(2+) in aqueous media ranging from 40.0 nM to 4.0 μM with a limit of detection of 32.0 nM and a good linearity (r=0.9980). Therefore, a facile, rapid, selective, and visual luminescence turn-on technology has been successfully developed for Hg(2+) detection. PMID:24054626

  1. Borate complexes of x-ray iodinated contrast agents: characterization and sorption studies for their removal from aqueous media.

    Science.gov (United States)

    Rustighi, Isabella; Donati, Ivan; Ferluga, Matteo; Campa, Cristiana; Pasqua, Adele E; Rossi, Marco; Paoletti, Sergio

    2012-02-29

    Iodinated contrast media (ICM) are persistent and ubiquitous water pollutants. Because of their high water solubility and biochemical stability, their phase-separation and recovery from the aquatic environment is very difficult. Here, borate was chosen as a complexing agent of the two diagnostic aids iomeprol and iopamidol in order to provide them with a negative charge and to fix the resulting adducts on Dowex 1X4 ion exchangers. A systematic characterization study of the complex by means of capillary zone electrophoresis and 11B NMR revealed that iomeprol and iopamidol interact with borate anions in aqueous solutions giving a 1:1 single-charged adduct and that the association constant at 25 °C for both contrast agents is highest at pH 10.5. These findings allowed the proper calibration of experimental parameters for further batch adsorption-desorption trials, where the two ICM were shown to be almost completely removed from the water phase and released from the solid sorbents in mild conditions, enabling the recovery of functional resin. PMID:22245510

  2. A Simple and Effective Ratiometric Fluorescent Probe for the Selective Detection of Cysteine and Homocysteine in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Risong Na

    2016-08-01

    Full Text Available Biothiols such as cysteine (Cys and homocysteine (Hcy are essential biomolecules participating in molecular and physiological processes in an organism. However, their selective detection remains challenging. In this study, ethyl 2-(3-formyl-4-hydroxyphenyl-4-methylthiazole-5-carboxylate (NL was synthesized as a ratiometric fluorescent probe for the rapid and selective detection of Cys and Hcy over glutathione (GSH and other amino acids. The fluorescence intensity of the probe in the presence of Cys/Hcy increased about 3-fold at a concentration of 20 equiv. of the probe, compared with that in the absence of these chemicals in aqueous media. The limits of detection of the fluorescent assay were 0.911 μM and 0.828 μM of Cys and Hcy, respectively. 1H-NMR and MS analyses indicated that an excited-state intramolecular proton transfer is the mechanism of fluorescence sensing. This ratiometric probe is structurally simple and highly selective. The results suggest that it has useful applications in analytical chemistry and diagnostics.

  3. Highly selective probe based on imine linkage for Zn2+ and HSO3− in mixed aqueous media

    International Nuclear Information System (INIS)

    A simple salicylaldehyde derived Schiff base N, N′- bis (p-chloro salicylidene)-1, 2- ethylenediamine (L) was synthesized and characterized. The receptor demonstrates simultaneous dual channel chromogenic and fluorogenic signaling towards HSO3− and Zn2+ in mixed aqueous media. Solvatochromism was employed systematically for modulating its optoelectronic properties. The probe was successfully assessed to monitor HSO3− detection via UV–vis spectroscopy. DFT calculations and 1H NMR spectroscopy further support the results based on shifting of equilibrium. Moreover, the sensor showed large fluorescence enhancement with blue-shift of 48 nm after addition of Zn2+. The probe exhibits high selectivity over other competitive ions with high detection limit of 6.54×10−5 M and 3.21×10−6 M for HSO3− and Zn2+, respectively. Importantly, this is one of the rare reports in which Schiff base was utilized for the fabrication of chromogenic or fluorogenic sensor using solvent effect for multianalyte detection. - Highlights: • Easy synthesis of highly selective and sensitive Salicylideneaniline moiety. • Solvatochromism induced tautomerism between the enol-imine and keto-amine forms. • Computational studies revealing the effect of solvent on stability of NH form. • Discriminative detection of HSO3− and Zn2+ by different spectroscopic techniques. • Optical feedbacks as absorption transitions with HSO3− on bisulphite adduct formation. • Fluorescence enhancement for Zn2+ based on imine binding mechanism

  4. Role of Citrate Ions in the Phosphonate-based Inhibitor System for Mild Steel in Aqueous Chloride Media

    Directory of Open Access Journals (Sweden)

    G. Gunasekaran

    2005-01-01

    Full Text Available The corrosion inhibition efficiency of phosphonic acid and its derivatives for the inhibition of corrosion of mild steel in neutral chloride media is decided by its ability to form protectivefilm over the surface. In this context, the effect of addition of metal cations and certain organic compounds, such as citrate in conjugation with phosphonic acid to impart synergistic corrosion inhibition has been explored. The experiments were carried out using various concentrations of trisodium citrate and zinc ions in an aqueous solution of 2-carboxyethyl phosphonic acid (2CEPA at 25 ppm. The corrosion characteristics have been determined using electrochemical impedance spectroscopy together with determination of corrosion rate by weight-loss method. It has been observed that a combination of inhibitive ions, namely citrate, ZCEPA, and zinc ions at 25 ppm gives 96 per cent inhibition efficiency and this corrosion inhibition is due to the formation of a protective film. By increasing the concentration of citrate beyond 25 ppm, the corrosion inhibition efficiency decreases. This paper discusses the role of citrate and zinc ions in imparting added corrosion inhibition ability using 2CEPA on the basis of experimental results.

  5. O2 solubility in aqueous media determined by a kinetic method.

    Science.gov (United States)

    Reynafarje, B; Costa, L E; Lehninger, A L

    1985-03-01

    A kinetic method for the determination of O2 solubility in air-saturated aqueous solutions of widely varying composition and temperature is described. It is based on the precise molar stoichiometry between the rates of uptake of H+ and O2, measured with response-matched electrodes, in the reaction NADH + H+ + 1/2O2----NAD+ + H2O, catalyzed by an NADH oxidase preparation. To the initially anaerobic test system, which contains an excess of NADH and NADH oxidase in a buffered medium, an aliquot of the O2-containing solution to be tested is added and the rates of both O2 uptake and H+ uptake are recorded; the H+ electrode is calibrated against standard HCl. From these data the amount of O2 in the aliquot is calculated. Some representative values for O2 solubility at 25 degrees C and 760 mm in air-saturated systems are (i) distilled H2O, 516 nmol O/ml, (ii) 0.15 M KCl, 480 nmol O/ml, and (iii) 0.25 M sucrose, 458 nmol O/ml. Data and equations are also given for the solubility of O2 at 760 mm in air-saturated and lightly buffered 0.15 M KCl and 0.25 M sucrose over the range 5 to 40 degrees C. In the method described the rates of O2 and H+ uptake are precisely linear and stoichiometric when NADH is present in large excess over O2. However, when O2 is in excess and small additions of 340-nm-standardized NADH are made, as in earlier methods based on NADH oxidation, the endpoint is approached very gradually and tends to overestimate O2 solubility, owing to (i) the higher Km for NADH than for O2, (ii) the relatively slow response of the Clark O2 electrode, and (iii) the incomplete oxidation of NADH in the presence of 340-nm-absorbing inhibitory substances. PMID:4014672

  6. Biocompatible ZnS:Mn quantum dots for reactive oxygen generation and detection in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Diestra, Daysi; Beltran-Huarac, Juan, E-mail: juan.beltran1@upr.edu; Bracho-Rincon, Dina P.; González-Feliciano, José A.; González, Carlos I.; Weiner, Brad R.; Morell, Gerardo [University of Puerto Rico, Molecular Sciences Research Center (United States)

    2015-12-15

    We report here the versatility of Mn-doped ZnS quantum dots (ZnS:Mn QDs) synthesized in aqueous medium for generating reactive oxygen species and for detecting cells. Our experiments provide evidence leading to the elimination of Cd-based cores in CdSe/ZnS systems by substitution of Mn-doped ZnS. Advanced electron microscopy, X-ray diffraction, and optical spectroscopy were applied to elucidate the formation, morphology, and dispersion of the products. We study for the first time the ability of ZnS:Mn QDs to act as immobilizing agents for Tyrosinase (Tyr) enzyme. It was found that ZnS:Mn QDs show no deactivation of Tyr enzyme, which efficiently catalyzed the hydrogen peroxide (H{sub 2}O{sub 2}) oxidation and its eventual reduction (−0.063 V vs. Ag/AgCl) on the biosensor surface. The biosensor showed a linear response in the range of 12 μmol/L–0.1 mmol/L at low operation potential. Our observations are explained in terms of a catalase-cycled kinetic mechanism based on the binding of H{sub 2}O{sub 2} to the axial position of one of the active copper sites of the oxy-Tyr during the catalase cycle to produce deoxy-Tyr. A singlet oxygen quantum yield of 0.62 in buffer and 0.54 in water was found when ZnS:Mn QDs were employed as a photosensitizer in the presence of a chemical scavenger and a standard dye. These results are consistent with a chemical trapping energy transfer mechanism. Our results also indicate that ZnS:Mn QDs are well tolerated by HeLa Cells reaching cell viabilities as high as 88 % at 300 µg/mL of QDs for 24 h of incubation. The ability of ZnS:Mn QDs as luminescent nanoprobes for bioimaging is also discussed.Graphical Abstract.

  7. Biocompatible ZnS:Mn quantum dots for reactive oxygen generation and detection in aqueous media

    International Nuclear Information System (INIS)

    We report here the versatility of Mn-doped ZnS quantum dots (ZnS:Mn QDs) synthesized in aqueous medium for generating reactive oxygen species and for detecting cells. Our experiments provide evidence leading to the elimination of Cd-based cores in CdSe/ZnS systems by substitution of Mn-doped ZnS. Advanced electron microscopy, X-ray diffraction, and optical spectroscopy were applied to elucidate the formation, morphology, and dispersion of the products. We study for the first time the ability of ZnS:Mn QDs to act as immobilizing agents for Tyrosinase (Tyr) enzyme. It was found that ZnS:Mn QDs show no deactivation of Tyr enzyme, which efficiently catalyzed the hydrogen peroxide (H2O2) oxidation and its eventual reduction (−0.063 V vs. Ag/AgCl) on the biosensor surface. The biosensor showed a linear response in the range of 12 μmol/L–0.1 mmol/L at low operation potential. Our observations are explained in terms of a catalase-cycled kinetic mechanism based on the binding of H2O2 to the axial position of one of the active copper sites of the oxy-Tyr during the catalase cycle to produce deoxy-Tyr. A singlet oxygen quantum yield of 0.62 in buffer and 0.54 in water was found when ZnS:Mn QDs were employed as a photosensitizer in the presence of a chemical scavenger and a standard dye. These results are consistent with a chemical trapping energy transfer mechanism. Our results also indicate that ZnS:Mn QDs are well tolerated by HeLa Cells reaching cell viabilities as high as 88 % at 300 µg/mL of QDs for 24 h of incubation. The ability of ZnS:Mn QDs as luminescent nanoprobes for bioimaging is also discussed.Graphical Abstract

  8. Detoxification of Hg(II) from aqueous and enzyme media: Pristine vs. tailored calcium alginate hydrogels.

    Science.gov (United States)

    Sarkar, Kangkana; Ansari, Zarina; Sen, Kamalika

    2016-10-01

    Calcium alginate (CA) hydrogels were tailored using phenolic compounds (PC) like, thymol, morin, catechin, hesperidin, during their preparation. The PC incorporated gels show modified surface features as indicated by scanning electron microscopic images (SEM). The rheological studies show that excepting the hesperidin incorporated gels all the other kinds including calcium alginate pristine have similar mechanical strength. The hesperidine incorporated CA gels had the maximum capacity to adsorb Hg. The Freundlich adsorption isotherms show higher values of adsorption capacity for all PC incorporated CA beads than the pristine CA (PCA). The hesperidin incorporated CA gels were found to show the best adsorption condition at neutral pH and an optimum contact time of 2.5h at 25°C. Considering the possibility of ingested Hg detoxification from human alimentary tract, the hesperidin and morin incorporated CA beads were further modified through incorporation of cod liver oil as the digestion time of fat in stomach is higher. In vitro uptake capacities of Hg in pepsin and pancreatin containing enzyme media were studied with hesperidin and morin incorporated beads and their corresponding fat incorporated beads also. In the pepsin medium, there was no uptake by hesperidin and fat-hesperidin incorporated beads, which is possibly due to the higher acidity of the medium. But in pancreatin medium Hg was taken up by both kinds of beads. Morin and morin-fat incorporated beads were efficient to uptake Hg from both the pepsin and pancreatin medium. The tailored CA beads may therefore serve as efficient scaffolds to rescue Hg ingested individuals. PMID:27208797

  9. Electrochemical oxidation of synthetic tannery wastewater in chloride-free aqueous media

    International Nuclear Information System (INIS)

    The electrochemical treatment of a synthetic tannery wastewater, prepared with several compounds used by finishing tanneries, was studied in chloride-free media. Boron-doped diamond (Si/BDD), antimony-doped tin dioxide (Ti/SnO2-Sb), and iridium-antimony-doped tin dioxide (Ti/SnO2-Sb-Ir) were evaluated as anode. The influence of pH and current density on the treatment was assessed by means of the parameters used to measure the level of organic contaminants in the wastewater; i.e., total phenols, chemical oxygen demand (COD), total organic carbon (TOC), and absorbance. Results showed that faster decrease in these parameters occurred when the Si/BDD anode was used. Good results were obtained with the Ti/SnO2-Sb anode, but its complete deactivation was reached after 4 h of electrolysis at 25 mA cm-2, indicating that the service life of this electrode is short. The Ti/SnO2-Sb-Ir anode is chemically and electrochemically more stable than the Ti/SnO2-Sb anode, but it is not suitable for the electrochemical treatment under the studied conditions. No significant changes were observed for electrolyses performed at different pH conditions with Si/BDD, and this electrode led to almost complete mineralization after 4 h of electrolysis at 100 mA cm-2. The increase in current density resulted in faster wastewater oxidation, with lower current efficiency and higher energy consumption. Si/BBD proved to be the best electrodic material for the direct electrooxidation of tannery wastewaters.

  10. N-[Isononylphenoxypoly(ethyleneoxy)carbonylmethyl]ammonium chlorides as inhibitors of metal corrosion. 1. Inhibition of steel corrosion in aqueous hydrochloric media

    International Nuclear Information System (INIS)

    New ammonium compounds of the type N-[isononylphenoxypoly (ethyleneoxy) carbonylmethyl] ammonium chlorides were synthesized. The compounds were studied as inhibitors of steel corrosion in hydrochloric aqueous media. High efficiency of the corrosion inhibitors suggested is shown. Dependence of their inhibiting properties on the type of substituents at nitrogen atom, length of hydrocarbon radicals and number of ethyleneoxide groups in isononylphenoxypoly (ethyleneoxy) carbonylmethyl radical was revealed

  11. Conversion of carbohydrate biomass to γ-valerolactone by using water-soluble and reusable iridium complexes in acidic aqueous media.

    Science.gov (United States)

    Deng, Jin; Wang, Yan; Pan, Tao; Xu, Qing; Guo, Qing-Xiang; Fu, Yao

    2013-07-01

    Mild-mannered manipulation: A catalytic method for the conversion of carbohydrate biomass to γ-valerolactone in acidic aqueous media has been developed. The water-soluble iridium complexes were observed to be extremely catalytically active for providing γ-valerolactone in high yields with high TONs. The homogeneous catalysts can also be recycled and reused by applying a simple phase separation process. PMID:23757330

  12. Translational diffusion coefficients and hydrodynamic radii of normal corn starch in aqueous media from asymmetrical flow field-flow fractionation experiments

    OpenAIRE

    Juna, Shazia; Huber, Anton

    2015-01-01

    Starch is a highly disperse material with broad distributions of molecular sizes and geometries. Its dissolution in aqueous media is difficult to achieve and it tends to form aggregates through both inter- and intra-molecular interactions. Asymmetrical flow field-flow fractionation (AF4) is a suitable technique for the separation of such macromolecular and colloidal systems. A major advantage of AF4 is the direct correlation of translational diffusion coefficients with retention time and expe...

  13. Renaissance Music in Croatia, and beyond

    Directory of Open Access Journals (Sweden)

    Vasco Zara

    2010-10-01

    Full Text Available Depuis la fin de l’année 2009, la base de données Renaissance Music in Croatia [http://ricercar.cesr.univ-tours.fr/3-programmes/EMN/Croatie/] est désormais consultable en ligne, en accès libre. Il s’agit de l’issue finale d’un projet de recherche de longue haleine, mené depuis 2006 entre le Centre d’études supérieures de la Renaissance de Tours et l’Académie des sciences et des arts de Zagreb. Ce projet a été rendu possible grâce au soutien du Partenariat Hubert Curien, COGITO, du ministère ...

  14. Generation III reactors - the nuclear renaissance

    International Nuclear Information System (INIS)

    The European Pressurized Reactor - GEN III+, the PWR type reactor, remains the world's first and currently being built power reactor everywhere. ATMEA1, a new 1,100 MWe pressurized water reactor combines state-of-the art- technology from AREVA and Mitsubishi Heavy Industries to meet the challenges of the nuclear renaissance. Thus, the next evolutionary design of Generation III reactors will be deployed over many decades and will represent a large part of the worldwide fleet throughout the 21st century. Generation III reactors will equip the future NPPs ensuring improved safety and reliability, with passive safety systems and a very low probability for core melt. The Generation III Reactors as 'The Nuclear Renaissance' is presented in the paper. (author)

  15. The drivers of the nuclear renaissance

    International Nuclear Information System (INIS)

    The renaissance of the nuclear option for generating electric energy is stimulated by its economic competitiveness and its social and environmental benefits. Presently, nuclear energy is a key component to the rapid expansion of world electricity consumption. Drivers of the nuclear renaissance are: the growth of public acceptance as result of the historic demonstration of safety; the economic competitiveness in the costs of generation; the incorporation of innovations and technological advances with impacts on main barriers like the reducing of the capital investments and technological solutions for destination of the radioactive wastes. The nuclear retaken already affects the international Uranium market with records of negotiated volumes and a rise of prices. Brazil as detainer of some of the biggest reserves of Uranium in the world has much to profit with this retaken. (author)

  16. Liturgie, transformasie en die Afrika Renaissance

    Directory of Open Access Journals (Sweden)

    B. de Klerk

    2001-08-01

    Full Text Available The African Renaissance concerns the moral, cultural and spiritual transformation of the African human being. Liturgy has a decisive impact on the vision, aspirations and hopes of the believer. Therefore, liturgy can have a significant influence on the African Renaissance if it adheres to fixed liturgical principles, the response of the believers is culturally bound and liturgy attains an indigenous character. As liturgy has the ability to restore human dignity and bring about reconciliation, believers can consequently gain confidence to co-operate in the healing process of the continent. Aspects of African culture displaying a close resemblance to the Bible should be developed, for example celebrating the presence of God, utilising the power of Scripture reading in liturgy, delivering sermons full of imagery, establishing an ubuntu of faith, using symbols inherent both in the Gospel and African culture, creating space for movement, communion and festivity, as well as developing songs, music and dances in a creative way.

  17. A study in Renaissance psychotropic plant ointments.

    Science.gov (United States)

    Piomelli, D; Pollio, A

    1994-01-01

    Various historical sources from the Renaissance--including transcripts of trials for witchcraft, writings on demonology and textbooks of pharmaceutical botany--describe vegetal ointments prepared by women accused of witchcraft and endowed with marked psychoactive properties. Here, we examine the botanical composition and the possible pharmacological actions of these ointments. The results of our study suggest that recipes for narcotic and mind-altering salves were known to Renaissance folk healers, and were in part distinct from homologous preparations of educated medicine. In addition, our study reveals an unexpected connection of these vegetal psychotropes with archaic chtonic beliefs, confirming the tight association between rituals and cults entered on the Underworld and the image of the Medieval witch. PMID:7724723

  18. Studies on anodic corrosion of the electroplated CdSe in aqueous and non-aqueous media for photoelectrochemical cells and characterization of the electrode/electrolyte interface

    International Nuclear Information System (INIS)

    Polycrystalline n-CdSe thin films were prepared by electrodeposition at controlled current density on conducting substrates. The optical characteristics were determined through transmittance spectra. Scanning electron microscopy and atomic force microscopy were employed to study the morphology of the semiconductor (SC) surfaces. Chemical composition of the SC film was established by EDAX analysis. The n-CdSe/electrolyte junctions in water and non-aqueous solvents like acetonitrile (ACN), dimethyl formamide (DMF), dimethyl sulphoxide (DMSO) and propylene carbonate (PC) were characterized by Mott-Schottky analysis using frequency response analyzer. The stability of CdSe layers in water and in non-aqueous solvents was determined through anodic polarization studies. Anodic stripping voltammetry was employed to find out the dissoluted Cd2+ in solution. Photovoltage was measured under illuminated conditions using ferrocene-ferricenium couple in aqueous and non-aqueous solvents throughout the temperature range of 20-70 deg. C. The results are indicative of the potential use of the electrodeposited n-CdSe in selected non-aqueous medium for solar energy conversion by photoelectrochemical (PEC) devices

  19. Renaissance Humanists:Defenders of Medieval Christian worldview

    Institute of Scientific and Technical Information of China (English)

    刘玥婷

    2006-01-01

    The Renaissance is a new golden age of intellectual achievement with a sharp contrast with the Middle Ages.Though new secular and scientific values begin to supplant traditional religious belief,there exists the continuity between the Middle Ages and the Renaissance,and humanists bear strong Christian character.They never change their devotion to Christianity and keep making their effort to maintain the primacy of Jesus.Humanists in Renaissance are defenders of medieval Christian view of the world.

  20. Fabrication of a green porous lignin-based sphere for the removal of lead ions from aqueous media

    International Nuclear Information System (INIS)

    Highlights: • A porous lignin-based sphere was prepared from lignosulfonate by a gelation method. • The porous lignin-based sphere (PLS) had a high porosity and pore volume. • The PLS showed high adsorption efficiency for lead ions from aqueous media. • Bed column test proved the potential of PLS for continuous treatment of effluent. - Abstract: A green porous lignin-based sphere (PLS) had been fabricated by a feasible gelation-solidification method from lignosulfonate cross-linked with sodium alginate and epichlorohydrin. The prepared sphere was characterized by Fourier transform infrared spectrometry, scanning electron microscopy, mercury intrusion porosimetry, and thermo gravimetric analysis. The results demonstrated the PLS had a large amount of mesopores (d = 20.7 nm) with a high porosity of 87.66% and a total pore volume of 0.416 cm3/g. Batchwise adsorption experiments indicated the PLS possessed excellent adsorption efficiency (95.6 ± 3.5%) for lead ions at an initial concentration of 25.0 mg/L. The adsorption process could be well fitted by intra-particle diffusion model and Langmuir isotherm model. Application of the PLS in bed column mode for the continuous treatment of lead solution exhibited prolonged breakthrough time from 75 min to 100 min as the bed column heights increased from 0.5 cm to 2.5 cm which was much better than the alkaline lignin column (2.5 cm height, breakthrough time = 60 min). The results strongly suggested the high possibility of the porous sphere being applied for the continuous treatment of heavy metals rich wastewater in industry

  1. Two-photon excited fluorescent chemosensor for homogeneous determination of copper(II) in aqueous media and complicated biological matrix.

    Science.gov (United States)

    Liu, Lingzhi; Dong, Xiaohu; Xiao, Yan; Lian, Wenlong; Liu, Zhihong

    2011-05-21

    In the present work, a two-photon excited fluorescent chemosensor for Cu(2+) was prepared. The probe was constructed on the basis of internal charge transfer (ICT) principle with macrocyclic dioxotetraamine as the Cu(2+) receptor. The good water-solubility of the molecule enabled recognition and assay of Cu(2+) ions in biological media. The photophysical properties of the chemosensor were investigated in detail, exhibiting favorable fluorescence quantum yield and moderate two-photon absorption cross-section. The studies on binding thermodynamics demonstrated the formation of 1 : 1 complex between the chemosensor and Cu(2+) and an association constant of ca. 1.04 × 10(5) M(-1). Due to the rational design of the molecular structure, the sensor was highly specific to Cu(2+), which ensured high selectivity in Cu(2+) determination. Upon Cu(2+) binding, the intramolecular charge-transfer extent within the chromophore was weakened resulting in a remarkable quenching of fluorescence, based on which quantitative determination of Cu(2+) was performed. Good linearity was obtained between the fluorescence quenching value and Cu(2+) concentration ranging from 0.04 to 2.0 μM in aqueous solution. Benefiting from the merits of two-photon excitation, the chemosensor was free of interference from background luminescence in serum. A homogeneous quantitative determination of Cu(2+) was achieved in the serum medium with a linear range of 0.04 to 2.0 μM. Considering the structural flexibility of the sensor, this work also opens up the possibility to construct other two-photon excited chemosensors for direct homogeneous assay of various molecules/ions in complicated biological sample matrices. PMID:21416097

  2. Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

    2000-02-01

    The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

  3. Self-media

    DEFF Research Database (Denmark)

    Fausing, Bent

    2015-01-01

    The self and identity are not only topics related to the selfies. They are connected to the development of media since the renaissance, the self-media. This is the thesis of the following. The subject, the self, is most clearly exposed in the face, and face and identity becomes important in the...... media since the renaissance. The selfies is just the newest development is this tradition, which began with the invention of the mirror, the book (printing), and the small painting. They all put the subject as both maker and receiver in the center. It was the beginning of the modern subject. The...... development continued throughout the coming centuries. The selfies is the newest creation to discover, explore, visualize and find the self of the subject. The following will thus emphasis the self, the face, where the self is most noticeably expressed and seen, and the self-media, where the individual can...

  4. 77 FR 23756 - Grant of Individual Exemption Involving Renaissance Technologies, LLC (Renaissance, or the...

    Science.gov (United States)

    2012-04-20

    ... exemption in the Federal Register at 77 FR 3038 from the restrictions of section 406(a)(1)(A) and (D) of the... procedures set forth in 29 CFR Part 2570, Subpart B (76 FR 66637, October 27, 2011). Effective December 31... have joined (and left) Renaissance, through the normal process of employee turnover. As a...

  5. Einheimische und exotische Tiere im Prag der Renaissance / Indigenous and Exotic Animals in Renaissance Prague

    Czech Academy of Sciences Publication Activity Database

    Dobalová, Sylva

    Wien : KHM-Museumsverband, 2015 - (Haag, S.), s. 37-47 ISBN 978-3-99020-097-1 Institutional support: RVO:68378033 Keywords : menagerie * Renaissance * Prague Castle * exotic animals * Lion´s Court Subject RIV: AL - Art, Architecture, Cultural Heritage

  6. Facing the challenges of the nuclear renaissance

    International Nuclear Information System (INIS)

    The Nuclear Renaissance is stumbling at the very same time it should speed up in order to help control the climate change and meet a fast growing energy need in a large part of the world. Rising costs of projects, uncertainties about their completion, rocketing safety requirements, and financial constraints are key factors which slow down the Nuclear Renaissance. Furthermore, the legal infrastructure required from any country to enter a commercial nuclear programme (safety authorities, fuel cycle, and waste disposal) is a major hurdle s which impedes consideration for small to mid size reactors, well suited for many countries. The paper prepared and presented by Alain Bugat (Chairman of NucAdvisor and former Head of the French Atomic Energy Commission), Dominique Vignon (CEO of NucAdvisor and former President and CEO of AREVA NP) and Michel Lecomte (Co-founder NucAdvisor) reviews the present status of the Nuclear Renaissance. Based on an analysis of initial versus actual plans for all projects announced during the last three years, it scrutinizes some key factors behind the postponements of start-up dates of construction, and cost increases. On each of the issues which jeopardize new projects, the paper will propose an adequate course of actions, to be taken by vendors, operators, governments and safety authorities as well as investors, financial institutions and banks. - Recommendations are developed with respect to: - A needed coordination between the Kyoto and post Kyoto mechanisms, and the nuclear industry; a financial assessment of the potential of such coordination will be presented; - A transformation of the national licensing processes, under a common International framework; it will take into consideration the experience of the Airspace industry, and a systematic mutual acceptance of licensing certificates; - An easier access for nuclear projects to the financial markets, based on the support of major Financial institutions (World Bank; BEI; etc

  7. The Art of the Renaissance Capitalist State

    Directory of Open Access Journals (Sweden)

    Rebeka Vidrih

    2007-12-01

    This article also highlights the fact that the concept of art developed in Florence – a city-state that played an important role in the early-capitalist world of the Renaissance, but never assumed a leading role like Venice and Genoa. »Art« was thus created through Florence’s efforts to demonstrate its equality and importance and, although it failed to achieve this in the field of the (capitalist economy, it at least succeeded in the field of the (absolutist state that was subordinate to this economy.

  8. The thesaurus review, renaissance, and revision

    CERN Document Server

    Roe, Sandra K

    2013-01-01

    Use this single source to uncover the origin and development of the thesaurus! The Thesaurus: Review, Renaissance, and Revision examines the historical development of the thesaurus and the standards employed for thesaurus construction. This book provides both the history of thesauri and tutorials on usage to increase your understanding of thesaurus creation, use, and evaluation. This reference tool offers essential information on thesauri in the digital environment, including Web sites, databases, and software. For 50 years, the thesaurus has been a core reference book; The Thesaurus: Review,

  9. The Quiet Renaissance of Protein NMR

    Science.gov (United States)

    Barrett, Paul J.; Chen, Jiang; Cho, Min-Kyu; Kim, Ji-Hun; Lu, Zhenwei; Mathew, Sijo; Peng, Dungeng; Song, Yuanli; Van Horn, Wade D.; Zhuang, Tiandi; Sönnichsen, Frank D.; Sanders, Charles R.

    2013-01-01

    From roughly 1985 through the start of the new millennium, the cutting edge of solution protein nuclear magnetic resonance (NMR) spectroscopy was to a significant extent driven by the aspiration to determine structures. Here we survey recent advances in protein NMR that herald a renaissance in which a number of its most important applications reflect the broad problem-solving capability displayed by this method during its classical era during the 1970s and early 80s. “Without receivers fitted and kept in order, the air may tingle and thrill with the message, but it will not reach my spirit and consciousness.” Mary Slessor, Calabar, circa 1910 PMID:23368985

  10. Ordered mesoporous carbon film as an effective solid-phase microextraction coating for determination of benzene series from aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hui [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); School of Geography Science, Nantong University, Nantong 226001 (China); Li, Jiansheng, E-mail: lijsh@mail.njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Jiang, Mingyue; Lu, Rui; Shen, Jinyou; Sun, Xiuyun; Han, Weiqing [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2015-08-12

    The present work reports preparation of ordered mesoporous carbon (OMC) film supported on a graphite fiber as a new type of solid-phase microextraction (SPME) fiber for determination of benzene series from aqueous media. The strategy for the supported OMC film preparation was combined dip-coating technology with solvent evaporation-induced self-assembly (EISA) approach. A graphite fiber was immersed in an ethanol solution containing phenolic resin and Pluronic triblock copolymer. Upon solvent evaporation and subsequent pyrolysis under 700 °C, the phenolic resin and the surfactant self-assembled on the surface of the graphite fiber to form smooth OMC film. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen isothermal adsorption results indicate that the resultant OMC film possesses well-ordered two dimensional hexagonal mesostructure with pore diameters of 4.5 nm and BET surfaces of 630 m{sup 2}/g. Scanning electron microscopy (SEM) studies show the supported OMC film with thickness at 8.5 μm is continuous and defect-free. The SPME efficiency of the OMC fiber was evaluated by analysis of five benzene series (benzene, toluene, ethylbenzene, p-xylene and m-xylene) from water samples by gas chromatography-flame ionization detection (GC-FID). The analysis results indicate that the prepared OMC fiber has wide linear ranges (0.5–500 μg/L), low detection limits (0.01–0.05 μg/L) and good repeatabilities (4.0–5.8% for one fiber, 2.9–8.7% for fiber-to-fiber). Compared with commercial counterparts, the OMC fiber exhibits improved extraction efficiency for benzene series and PAHs. - Highlights: • Ordered mesoporous carbon film supported on graphite fiber was first reported as solid-phase microextraction coating. • The strategy for the film preparation was combined dip-coating technology with evaporation-induced self-assembly approach. • The obtained fiber showed enhanced thermal stability and organic solvents resistance. • The

  11. Ordered mesoporous carbon film as an effective solid-phase microextraction coating for determination of benzene series from aqueous media

    International Nuclear Information System (INIS)

    The present work reports preparation of ordered mesoporous carbon (OMC) film supported on a graphite fiber as a new type of solid-phase microextraction (SPME) fiber for determination of benzene series from aqueous media. The strategy for the supported OMC film preparation was combined dip-coating technology with solvent evaporation-induced self-assembly (EISA) approach. A graphite fiber was immersed in an ethanol solution containing phenolic resin and Pluronic triblock copolymer. Upon solvent evaporation and subsequent pyrolysis under 700 °C, the phenolic resin and the surfactant self-assembled on the surface of the graphite fiber to form smooth OMC film. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen isothermal adsorption results indicate that the resultant OMC film possesses well-ordered two dimensional hexagonal mesostructure with pore diameters of 4.5 nm and BET surfaces of 630 m2/g. Scanning electron microscopy (SEM) studies show the supported OMC film with thickness at 8.5 μm is continuous and defect-free. The SPME efficiency of the OMC fiber was evaluated by analysis of five benzene series (benzene, toluene, ethylbenzene, p-xylene and m-xylene) from water samples by gas chromatography-flame ionization detection (GC-FID). The analysis results indicate that the prepared OMC fiber has wide linear ranges (0.5–500 μg/L), low detection limits (0.01–0.05 μg/L) and good repeatabilities (4.0–5.8% for one fiber, 2.9–8.7% for fiber-to-fiber). Compared with commercial counterparts, the OMC fiber exhibits improved extraction efficiency for benzene series and PAHs. - Highlights: • Ordered mesoporous carbon film supported on graphite fiber was first reported as solid-phase microextraction coating. • The strategy for the film preparation was combined dip-coating technology with evaporation-induced self-assembly approach. • The obtained fiber showed enhanced thermal stability and organic solvents resistance. • The fiber

  12. Philadelphia's Renaissance Schools: Start up and Early Implementation. Executive Summary

    Science.gov (United States)

    Research for Action, 2011

    2011-01-01

    In April 2009, Superintendent Arlene Ackerman announced her reform plan for the School District of Philadelphia (the District)--"Imagine 2014". Among other major initiatives, "Imagine 2014" laid the groundwork for Philadelphia's Renaissance Schools Initiative. The Renaissance Initiative, set to enter its second year in 2011-12, is an effort to…

  13. Colorimetric and fluorogenic recognition of Hg2+ and Cr3+ in acetonitrile and their test paper recognition in aqueous media with the aid of rhodamine based sensors.

    Science.gov (United States)

    Patidar, Rajesh; Rebary, Babulal; Paul, Parimal

    2015-03-01

    Two new rhodamine derivatives (L1 and L2) were synthesized, characterized and their ion recognition property has been investigated. Both of the ionophores exhibit colorimetric and fluorogenic response for Hg(2+) and Cr(3+) ions among large number of alkali, alkaline earth and transition metal ions tested in acetonitrile. Detail studies on determination of binding constant, binding mode, reversibility of binding, lower detection limit have been carried out. Detection of metal ions in aqueous media has also been demonstrated by preparation of simple, convenient and disposable test paper sensors with two approaches viz. filter paper and membrane filter loaded with these ionophores. Both of these methods responded sharply to both the metal ions (Hg(2+) and Cr(3+)) in aqueous solution, detectable by bared-eye. For better sensing at low concentration of metal ions, reprecipitation followed by filtration enrichment of ligands on membrane filter was employed. PMID:25666715

  14. Thermal MEMS actuator operation in aqueous media/seawater: Performance enhancement through atomic layer deposition post processing of PolyMUMPs devices

    International Nuclear Information System (INIS)

    A method to enhance thermal microelectromechanical systems (MEMS) actuators in aqueous media by using dielectric encapsulation layers is presented. Aqueous media reduces the available mechanical energy of the thermal actuator through an electrical short between actuator structures. Al2O3 and TiO2 laminates with various thicknesses were deposited on packaged PolyMUMPs devices to electrically separate the actuator from the aqueous media. Atomic layer deposition was used to form an encapsulation layer around released MEMS structures and the package. The enhancement was assessed by the increase of the elastic energy, which is proportional to the mechanical stiffness of the actuator and the displacement squared. The mechanical stiffness of the encapsulated actuators compared with the noncoated actuators was increased by factors ranging from 1.45 (for 45 nm Al2O3 + 20 nm TiO2) to 1.87 (for 90 nm Al2O3 + 40 nm TiO2). Displacement measurements were made for all laminate combinations in filtered tap water and seawater by using FFT based displacement measurement technique with a repeatability of ∼10 nm. For all laminate structures, the elastic energy increased and enhanced the actuator performance: In seawater, the mechanical output energy increased by factors ranging from 5 (for 90 nm Al2O3) to 11 (for 90 nm Al2O3 + 40 nm TiO2). The authors also measured the long-term actuator stability/reliability in seawater. Samples were stored for 29 days in seawater and tested for 17 days in seawater. Laminates with TiO2 layers allowed constant operation over the entire measurement period

  15. Cooperative catalysis of noncompatible catalysts through compartmentalization: wacker oxidation and enzymatic reduction in a one-pot process in aqueous media.

    Science.gov (United States)

    Sato, Hirofumi; Hummel, Werner; Gröger, Harald

    2015-04-01

    A Wacker oxidation using CuCl/PdCl2 as a catalyst system was successfully combined with an enzymatic ketone reduction to convert styrene enantioselectively into 1-phenylethanol in a one-pot process, although the two reactions conducted in aqueous media are not compatible due to enzyme deactivation by Cu ions. The one-pot feasibility was achieved via compartmentalization of the reactions. Conducting the Wacker oxidation in the interior of a polydimethylsiloxane thimble enables diffusion of only the organic substrate and product into the exterior where the biotransformation takes place. Thus, the Cu ions detrimental to the enzyme are withheld from the reaction media of the biotransformation. In this one-pot process, which formally corresponds to an asymmetric hydration of alkenes, a range of 1-arylethanols were formed with high conversions and 98-99 % ee. In addition, the catalyst system of the Wacker oxidation was recycled 15 times without significant decrease in conversion. PMID:25704961

  16. Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

    International Nuclear Information System (INIS)

    Adsorbents obtained by hydrolysing the Fe3+, 6H2O ion are made of polymers with aquo (H2O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn2+, Co2+ and Mn2+ cations are exchanged with hydrogen from hydroxo groups. CrO42-, SeO32- and Sb(OH)6- anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn2+ and Sb(OH)6- associate with ferric hydroxides from oxidized Fe2+. 60Co, 54Mn and 51Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author)

  17. Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media - A study on zinc, copper and nickel

    International Nuclear Information System (INIS)

    Membrane filtration is commonly performed for solid-liquid separation of aqueous solutions prior to trace metal analysis and when assessing 'dissolved' metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples. Filtration using both non-cleaned and pre-cleaned filters revealed contamination and adsorption effects, in particular pronounced for zinc, evident for copper but non-significant for nickel. The results clearly show these artifacts to be non-systematic both for non-cleaned and pre-cleaned membranes. The applied pressure was of minor importance. Measurements of the labile fraction by means of stripping voltammetry clearly elucidate that membrane filtration followed by total metal analysis cannot accurately assess the labile or the dissolved metal fraction. - Highlights: → Membrane filtration for trace metal analysis can introduce significant artifacts. → The dissolved metal fraction cannot be assessed by membrane filtration. → Non-specified filtration procedures are inadequate for scientific studies. → Artifacts caused by membrane filtration need to be addressed by regulators. - Membrane filtration cannot be used to assess the dissolved metal fraction of aqueous media and needs to be defined in detail in standard tests.

  18. Synthesis and characterization of ferrous phosphate (vivianite) and its behavior in aqueous media; Sintesis y caracterizacion del fosfato ferroso (vivianita) y su comportamiento en medio acuoso

    Energy Technology Data Exchange (ETDEWEB)

    Diaz F, J.C

    2003-07-01

    The synthesis and characterization of materials that can be useful in Environmental Chemistry is very important because their characteristics are exposed and its behavior in chemical phenomena as the sorption in aqueous media is understand to use it in the human being benefit. With the object of using, in a future, the octa hydrated ferrous phosphate (vivianite) as a potential candidate for matrix confinement in contention walls for the storage of radioactive waste of long half life, it was synthesized and it characterized physico chemically and their properties of surface of this compound were evaluated. Presently work was carried out the synthesis and structural characterization of the iron phosphate II by infrared spectroscopy with having Fourier transform, high vacuum scanning electron microscopy, X-ray diffraction, thermal gravimetric analysis, the BET multipoint surface area and Moessbauer spectroscopy; as well as, the determination between aqueous media of the isoelectric point and the density of sites of surface of the compound. The octa hydrated ferrous phosphate was obtained pure. The results indicate that the product corresponds to the prospective mineral, the vivianite. The thermal gravimetric analysis demonstrated that the ferrous phosphate is a stable salt after the lost of water. The isoelectric point is since an important parameter because allows to know the behavior of the surface of the material in aqueous systems, in this case the isoelectric point, of the octa hydrated ferrous phosphate, in distilled water is of pH 4.20 and in solution of potassium nitrate 0.5 M is of pH = 3.75. This indicates that the material has an amphoteric surface depending on the pH. On the other hand, the density of active sites of surface obtained by titrations acid-base is of 20 sites by nm{sup 2}. (Author)

  19. Renaissance Energy Ltd. 1998 annual report

    International Nuclear Information System (INIS)

    Renaissance Energy Ltd. faced many economic challenges during 1998 mainly due to low world oil prices which severely impacted the Company's financial performance for the year. Nevertheless, the Company pursued a tightly focused capital investment program in 1998 resulting in additions to both their reserves and production volumes. The most significant event was the acquisition of Pinnacle Resources Ltd. The report presents a review of the current environment, future expectations and business initiatives in terms of exploration and development, non-traditional opportunities, cost efficiencies, technological innovations, property acquisitions/dispositions, and international ventures. Financial highlights and consolidated balance sheets for 1998 are provided, including operating and capital expenditures and associated amounts payable. tabs., figs

  20. Solvolysis of titanium tetrachloride in non-aqueous media as a method for producing titanium dioxide particles of different morphology

    OpenAIRE

    A. M Nemeryuk; M. M Lylina

    2015-01-01

    The processes of solvolysis of titanium tetrachloride in nonaqueous media were studied. The influence of the conditions of solvolysis on the size and morphology of the particles of titanium dioxide produced have been described.

  1. Determination of Roxithromycin Tablets by Capillary Electrophoresis Employing Non-aqueous Media with Square-wave Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method of determination for roxithromycin tablets by non-aqueous capillary electrophoresis (NACE) with square-wave amperometric detection was carried out. Several parameters affecting the NACE-AD determination were studied. The data was modified by spline wavelet least square (SWLS). The method is simple, rapid and highly reliable for routine analysis.

  2. On the influence of hydronium and hydroxide ion diffusion on the hydrogen and oxygen evolution reactions in aqueous media

    DEFF Research Database (Denmark)

    Wiberg, Gustav Karl Henrik; Arenz, Matthias

    2015-01-01

    We present a study concerning the influence of the diffusion of H+ and OH- ions on the hydrogen and oxygen evolution reactions (HER and OER) in aqueous electrolyte solutions. Using a rotating disk electrode (RDE), it is shown that at certain conditions the observed current, i.e., the reaction rate...

  3. Monitoring the Rate Solvolytic Decomposition of Benzenediazonium Tetrafluoroborate in Aqueous Media Using a pH Electrode

    Science.gov (United States)

    Wiseman, Floyd L.

    2005-01-01

    A lab rotary experiment using the pH measurements of an aqueous solution to monitor the course of a solvolytic reaction was conducted. This experiment allowed the students to gain experience in taking precise pH measurement, to use nonlinear analysis techniques for analyzing kinetic data and to use the Arrhenius equation for determination of…

  4. MICROWAVE-ASSISTED CHEMISTRY: SYNTHESIS OF AMINES AND HETEROCYCLES VIA CARBON-NITROGEN BOND FORMATION IN AQUEOUS MEDIA

    Science.gov (United States)

    Improved C-N bond formation under MW influence is demonstrated by a) solventless three-component coupling reaction to generate propargyl amines that uses only Cu (I); b) aqueous N-alkylation of amines by alkyl halides that proceeds expeditiously in the presence of NaOH to deliver...

  5. SELF-MEDIA

    DEFF Research Database (Denmark)

    Fausing, Bent

    2014-01-01

    The self and identity are not only issues connected to the selfies. They are connected to the development of media since the renaissance; this is the thesis of the following key-note. The subject, the self, is most clearly exposed in the face, and face and identity becomes important in the media...... continued throughout the coming centuries. The selfies is the latest invention to discover, explore, visualize and find the self of the subject. The following will therefore naturally focus on the self, the face where the self is most clearly expressed and seen, and the self-media, where the subject can...

  6. Architecture and the arts in Catalonia during the Renaissance

    OpenAIRE

    Joaquim Garriga

    2016-01-01

    This is an overview of the process of transformation of the architecture, sculpture and painting of Catalonia during the Renaissance. It attempts to reconstruct the fundamental era of changes when the late Gothic models were replaced by the new Renaissance paradigm gestated in Italy, thus ushering in the modern cycle of arts in the country. Despite the relative dearth of a Catalan historiographic tradition that studies and explains the cultural heritage from this period – which was decimated ...

  7. An abbreviated history of the ear: from Renaissance to present.

    OpenAIRE

    Hachmeister, Jorge E.

    2003-01-01

    In this article we discuss important discoveries in relation to the anatomy and physiology of the ear from Renaissance to present. Before the Renaissance, there was a paucity of knowledge of the anatomy of the ear, because of the relative inaccessibility of the temporal bone and the general perception that human dissections should not be conducted. It was not until the sixteenth century that the middle ear was described with detail. Further progress would be made between the sixteenth and eig...

  8. Metal catalysts impregnated on porous media for aqueous phenol decomposition within three-phase fluidized-bed reactor

    International Nuclear Information System (INIS)

    Performance of metal catalysts to decompose aqueous phenol was experimentally investigated. Comparison of the phenol decomposition rates within three-phase fluidized-bed reactors utilizing only O3, TiO2 deposited on silica beads, metal catalyst (Ni or Co) impregnated on mesoporous carbon beads, or O3 in combination with each catalyst was thoroughly examined. It was found that the use of Co catalyst with the presence of O3 led to the best removal condition which aqueous phenol was completely decomposed within 10 min (k = 0.1944 min-1). In contrast, the use of TiO2 without O3 resulted in the worst decomposition of phenol (k = 0.0066 min-1). Some intermediate products, such as hydroquinone and catechol, were also detected but their final concentrations were negligibly low.

  9. Recovery of metals from simulant spent lithium-ion battery as organophosphonate coordination polymers in aqueous media.

    Science.gov (United States)

    Perez, Emilie; Andre, Marie-Laure; Navarro Amador, Ricardo; Hyvrard, François; Borrini, Julien; Carboni, Michaël; Meyer, Daniel

    2016-11-01

    An innovative approach is proposed for the recycling of metals from a simulant lithium-ion battery (LIBs) waste aqueous solution. Phosphonate organic linkers are introduced as precipitating agents to selectively react with the metals to form coordination polymers from an aqueous solution containing Ni, Mn and Co in a hydrothermal process. The supernatant is analyzed by ICP-AES to quantify the efficiency and the selectivity of the precipitation and the materials are characterized by Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Thermogravimetric Analyses (TGA) and nitrogen gas sorption (BET). Conditions have been achieved to selectively precipitate Manganese or Manganese/Cobalt from this solution with a high efficiency. This work describes a novel method to obtain potentially valuable coordination polymers from a waste metal solution that can be generalized on any waste solution. PMID:27362538

  10. High acceleration of the direct aldol reaction cocatalyzed by BINAM-prolinamides and benzoic acid in aqueous media

    OpenAIRE

    Guillena Townley, Gabriela; Hita López, María del Carmen; Nájera Domingo, Carmen

    2006-01-01

    The enantioselective direct aldol reaction, organocatalyzed by recoverable BINAM-prolinamide derivatives can be highly accelerated by a catalytic amount of a carboxylic acid without a detrimental of the obtained enantioselectivities. From the study of suitable acids and reaction conditions, benzoic acid in aqueous DMF or in water was shown to give the best results with high yields and enantioselectivities. Thus, the reaction between p-nitrobenzaldehyde and acetone catalyzed by (Sa)-B...

  11. A Simple One-pot Synthesis of 3,5-Dicyano-1,2-dihydropyrid-2-ones in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    ZHUANG, Qi-Ya; XU, Jia-Ning; TU, Shu-Jiang; JIA, Run-Hong; ZHANG, Jun-Yong; LI, Chun-Mei; ZHOU, Dian-Xiang

    2007-01-01

    A simple and clean synthesis of 3,5-dicyano-1,2-dihydropyrid-2-ones by a one-pot three-component reaction of malononitrile, aromatic aldehydes and 2-cyanoacetamide or 2-cyanothioacetamide has been achieved in an aqueous solution with potassium carbonate as a base under microwave irradiation without a phase transfer reagent. This protocol has the advantages of short reaction time (5-8 min) and convenient work-up.

  12. 1D chain fluorescein-functionalized gold and silver nanoparticles as new optical mercury chemosensor in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Lodeiro, Javier; Nunez, Cristina; Oliveira, Elisabete; Capelo, Jose Luis; Lodeiro, Carlos, E-mail: cle@fct.unl.pt [University NOVA of Lisbon, BIOSCOPE Group, REQUIMTE/CQFB, Chemistry Department, Faculty of Science and Technology (Portugal)

    2013-08-15

    A colorimetric system using noble metal nanoparticles (NPs), for the detection of small concentrations of mercury ion (Hg{sup 2+}) in water is described. Fluorescein-functionalized Au and Ag NPs were self-assembled into networks of one-dimensional chains in the presence of mercury(II) by chelation process; this causes an easily optical measurable change in the absorption spectrum of the particles in aqueous solution.

  13. A Renaissance Depiction of a Tornado.

    Science.gov (United States)

    Hoinka, Klaus P.; de Castro, Manuel

    2005-04-01

    In the Renaissance, impressive weather features inspired considerable interest among artists. The depiction of a tornado and other weather features are discussed that appear on a sixteenth-century series of 12 huge tapestries (“Conquest of Tunis”) woven by the carpet manufacturer Willem de Pannemaker in Brussels, Belgium, between 1549 and 1551. The outstanding depiction of the tornado is presumably the earliest pictorial presentation of a tornado, at least in the Latin west.During the Renaissance, tapestries were an obligatory fixture of a European court and were used as an instrument for political propaganda and dynastic demonstration. The “Conquest of Tunis” tapestries are important pieces of Eu-ropean art commissioned by the Habsburgian emperor Charles V (1500–58), one of the most important ruling personalities in Euro-pean history. In 1535, he undertook a crusade to Tunis, Tunisia, in order to diminish the Ottoman emperor's power in the western Mediterranean region. Charles V wanted to ensure that the expedition would not be forgotten. In order to guarantee this, the emperor took along the Flemish painter Jan Cornelisz Vermeyen who painted sketches that were used as prototypes for the “Conquest of Tunis” tapestries. These present a highly detailed narrative of the expedition to Tunis.The depiction of a tornado, along with heavy rain and a sandstorm, raises the question of why these meteorological features are included in the scene. To the authors' knowledge, no mention is made of them in the art literature (except for the sandstorm, which actually occurred). This is particularly surprising because the tornado, at least, appears so prominently in one of the tapestries. Therefore, the weather features are discussed in terms of their meteorological, decorative, and symbolic importance. The tornado and the heavy rain seem to have been rendered in order to emphasize symbolically the beginning and ending of the military campaign. Although these weather

  14. The solubility of hydrous thorium(IV) oxide in chloride media: Development of an aqueous ion-interaction model

    International Nuclear Information System (INIS)

    The solubility of hydrous Th(IV) oxide was measured in NaCl solutions ranging in concentration form 0.6 to 3.0 M and in KCl at 0.6 M, over a wide range of hydrogen ion concentration (psub(cH+) 3 to 11)), and over equilibration times extending to more than one year. Our results show solubilities higher (by three to four orders of magnitude) than have been reported by other investigations in NaClO4 media. Our thermodynamic modelling calculations indicate that these differences in solubility are a result of differences in the ionic media and the ionic strength of the solutions. We have used the thermodynamic model of Pitzer and coworkers, which is valid to high ionic strengths, to analyze our data for solubility in both chloride and perchlorate media. The analysis required the use of specific ion-interaction parameters only for the bare Th4+ ion with the bulk anion Cl-. The final thermodynamic model gives a good representation of all of our solubility data in NaCl and KCl solutions below psub(cH+) of ∝ 7 as well as the solubility data in NaClO4 media and the osmotic data for ThCl4 solutions. (orig.)

  15. Turn-On Ratiometric Fluorescent Probe for Selective Discrimination of Cr(3+) from Fe(3+) in Aqueous Media for Living Cell Imaging.

    Science.gov (United States)

    Rasheed, Lubna; Yousuf, Muhammad; Youn, Il Seung; Yoon, Taeseung; Kim, Kwang-Youn; Seo, Young-Kyo; Shi, Genggongwo; Saleh, Muhammad; Hur, Jin-Hoe; Kim, Kwang S

    2015-11-01

    Pyrene-based turn-on ratiometric fluorescent probe 1 demonstrates high sensitivity and exceptional selectivity toward Cr(3+) in the presence of other metals, including Fe(3+) in aqueous media. Interaction of Cr(3+) with probe 1 brings pyrene moieties close enough to have better aligned π-π stacking, thus enhancing the excimer peak many fold. On the other hand, the interaction of Fe(3+) with probe 1 brings forth a negligible difference in stacking, resulting in an insignificant change in fluorescence intensity. Exceptional selectivity of probe 1 with Cr(3+) over Fe(3+) and other metals has been confirmed by theoretical studies in addition to experimental results. Imaging of HeLa cells observed by confocal fluorescence microscopy reveals that probe 1 can be used to monitor Cr(3+) in live cells to map its subcellular distribution. PMID:26418848

  16. Study on electrochemical reduction of styrene oxide in aqueous media%环氧苯乙烷的水相电化学还原反应

    Institute of Scientific and Technical Information of China (English)

    钟伟强; 梁向晖; 黄精美

    2016-01-01

    This paper describes a highly efficient and environmental friendly organic experiment,i.e.,the electrochemical reduction of styrene oxide in aqueous media, which was designed for the undergraduate explorative teaching.The reaction was carried out in a small scale,taking Zn as anode and cathode in aqueous media.The styrene oxide was reduced to styrene employing electons as redox reagents.Through determination by GC,1 H NMR and 1 3 C NMR,the yield was as high as 95%.By introducing the novel research result into undergraduate teaching,the interest and the capability of the students on the research are increased,which can obtain a good course evaluation.%以高效、绿色环保为目标,开展了“探索性实验”项目———环氧苯乙烷水相电化学还原反应。实验采用微量化反应,水为溶剂,以 Zn-Zn 为电极体系,电子作为氧化剂或还原剂,利用现场制备的具有三维空间结构的纳米锌,将环氧苯乙烷还原成苯乙烯目标产物。通过气相色谱、1 H NMR 和13 C NMR 等手段对产物进行表征并验证,产率达到95%。将该科研成果引入本科生实验教学,学生通过接触科学前沿以提高学习兴趣,培养学生的科研素质和增强学生的科研能力,教学效果好。

  17. Interactions of carbon nanotubes with aqueous/aquatic media containing organic/inorganic contaminants and selected organisms of aquatic ecosystems--A review.

    Science.gov (United States)

    Boncel, Sławomir; Kyzioł-Komosińska, Joanna; Krzyżewska, Iwona; Czupioł, Justyna

    2015-10-01

    Due to their unique molecular architecture translating into numerous every-day applications, carbon nanotubes (CNTs) will be ultimately an increasingly significant environmental contaminant. This work reviews qualitative/quantitative analyses of interactions of various types of CNTs and their chemically modified analogues with aqueous/aquatic media containing organic and inorganic contaminants and selected organisms of aquatic ecosystems. A special emphasis was placed on physicochemical interactions between CNTs as adsorbents of heavy metal cations and aromatic compounds (dyes) with its environmental consequences. The studies revealed CNTs as more powerful adsorbents of aromatic compounds (an order of magnitude higher adsorption capacity) than metal cations. Depending on the presence of natural organic matter (NOM) and/or co-contaminants, CNTs may act as Trojan horse while passing through biological membranes (in the absence of NOM coordinating metal ions). Nanotubes, depending on flow conditions and their morphology/surface chemistry, may travel with natural waters or sediment with immobilized PAHs or metals and/or increase cyto- and ecotoxicity of PAHs/metal ions by their release via competitive complexation, or cause synergic ecotoxicity while adsorbing nutrients. Additionally, toxicity of CNTs against exemplary aquatic microorganisms was reviewed. It was found for Daphnia magna that longer exposures to CNTs led to higher ecotoxicity with a prolonged CNTs excretion. SWCNTs were more toxic than MWCNTs, while hydrophilization of CNTs via oxidation or anchoring thereto polar/positively charged polymer chains enhanced stability of nanotubes dispersion in aqueous media. On the other hand, bioavailability of functionalized CNTs was improved leading to more complex both mechanisms of uptake and cytotoxic effects. PMID:26022284

  18. Fluorescent Detection of 2,4-DNT and 2,4,6-TNT in Aqueous Media by Using Simple Water-Soluble Pyrene Derivatives.

    Science.gov (United States)

    Kovalev, Igor S; Taniya, Olga S; Slovesnova, Nataliya V; Kim, Grigory A; Santra, Sougata; Zyryanov, Grigory V; Kopchuk, Dmitry S; Majee, Adinath; Charushin, Valery N; Chupakhin, Oleg N

    2016-03-01

    Pyrene-containing water-soluble probes for the fluorescent detection of nitroaromatic compounds (NACs), such as explosive components (2,4-DNT and 2,4,6-TNT) and herbicides (2,4-dinitrocresol, 2,4-DNOC), in aqueous media are reported. In the probes, the introduction of surface-active hydrophilic "heads" at the periphery of lipophilic (i.e., hydrophobic) pyrene "tails" resulted in the formation of highly fluorescent micelle-like aggregates/pre-associates in aqueous solutions at concentrations of ≤10(-5)  m. The enhanced fluorescence quenching of the herein reported architectures is achieved in the presence of ultra-trace amounts of TNT or 2,4-DNT with values of Stern-Volmer quenching constant close to 1×10(5)  m(-1) and a detection limit as low as 182 ppb. The most hydrophilic probes demonstrated higher response to 2,4-DNT over TNT. Filter paper test strips impregnated with 1×10(-5)  m solutions of the probes were able to detect TNT, 2,4-DNT, and other NACs at levels as low as 50 ppb in water. PMID:26757403

  19. Self-aggregation of ionic liquid 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [C4mmim][BF4] in aqueous media: A conductometric, volumetric and spectroscopic study

    International Nuclear Information System (INIS)

    Highlights: • Self-aggregation behaviour of [C4mmim][BF4] has been studied using various techniques. • Thermodynamic parameters showing aggregation is an entropy-driven process. • Volumetric analysis indicates aggregation is influenced by solute–solvent interactions. • 1H NMR revealed formation of loosely bound aggregates in the system. - Abstract: Aggregation behaviour of ionic liquid (IL), 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [C4mmim][BF4] in aqueous media has been studied by electrical conductivity, density and speed of sound measurements across temperature range (288.15–308.15) K. The critical aggregation concentration (cac), the standard Gibb’s free energy of aggregation, ΔG°agg, adiabatic compressibility, βS and changes in the adiabatic compressibility upon aggregation, ΔβS,agg for the IL in aqueous solution have been derived from the experimental data. Further to get the deeper insights into the aggregation process spectroscopic study using 1H NMR measurements have been carried out. The aggregation behaviour observed from conductance and volumetric approaches has been found to be in good agreement with each other. NMR study revealed the formation of loosely bound ion associates as aggregates in the system upon aggregation

  20. The nuclear renaissance: Is it real?

    International Nuclear Information System (INIS)

    Around five years ago there were fundamental changes underway in the energy industry. Then, electric utilities across the United states were dealing with the unintended consequences of a patchwork of deregulation efforts. Despite the condition of the U.S. economy, within the next decade, the country will need more electricity. And pollution free nuclear power has to be an important part of the mix. The article addresses the status of the nuclear renaissance in the U.S.A. Then it addresses the European nuclear revival after two decades during which the old Europe slid down the slope towards a nuclear power phase-out and the newly independent countries of central and eastern Europe struggled to maintain the nuclear plants they inherited from the Soviet era. Decision-makers in a growing number of countries are starting to talk openly about a new nuclear era for the European continent. The collapse of the Soviet bloc eventually brought six largely pro nuclear countries, heavily dependent on nuclear power and with long histories of power reactor operation, to the European Union. The fate of nuclear in Europe still has an immense impact on what happens elsewhere, if only because Europe was one of the cradles of nuclear power development, wields high political and economical influence, and hosts two of the world's four or five major nuclear reactor equipment vendors.

  1. The nuclear renaissance in the United States

    International Nuclear Information System (INIS)

    This document is not a true report but a succession of transparencies listing the main titles of subjects that have been developed in oral form at the international topical meeting: TopFuel'99. The different subjects developed during the lecture were: -why a renaissance? -how is the market place changing? -how is nuclear generation changing? -growing awareness of clean air contributions -what has changed for the existing U.S. plants -what has changed for future U.S. plants. A plot is given presenting the capacity factor (in %) for the operating and the all plants for the years 1980 to 1998. A chart presenting the costs (including the 1994-1996 production costs + estimated capital + general and administrative costs) in cents/kWh per plant is given. It shows how the plants are positioned relative to an assumed market clearing price of 2.0-3.0 cents/kWh. A few plants would be competitive at market clearing prices below 2.0 cents/kWh, a few would not be competitive even in a 3.0 cent/kWh market. The majority of U.S. nuclear power plants would be competitive if markets clear between 2.0 cents and 3.0 cents/kWh. (O.M.)

  2. Future studies on electron scattering; a renaissance

    International Nuclear Information System (INIS)

    2014 is the centenary of the first announcement of the Franck-Hertz experiment [1], now regarded as one of the pivotal experiments of modern physics. The Franck-Hertz experiment is widely regarded as an experiment that provided validation of the Bohr theory of atomic structure, itself only published in 2013, however it should also be viewed as the first quantitative experiment in electron scattering and the birth of scientific study of atomic and molecular phenomena by collisions. Today we recognize that electron-atom and electron- molecule collisions are prevalent across nature, describing disparate phenomena whilst the exploitation of such collisions underpins many of the technologies upon which modern society relies. The centenary of the Franck-Hertz experiment is thus a suitable opportunity to review both our current knowledge of electron interactions and to consider the directions of future research. In this article I therefore aim to both review our current state of knowledge and look forward, proposing that recent advances are providing something of a renaissance to the field and are vital for emerging technologies as well as answering some of the greatest scientific challenges of the 21st century

  3. Drivers for the renaissance of coal.

    Science.gov (United States)

    Steckel, Jan Christoph; Edenhofer, Ottmar; Jakob, Michael

    2015-07-21

    Coal was central to the industrial revolution, but in the 20th century it increasingly was superseded by oil and gas. However, in recent years coal again has become the predominant source of global carbon emissions. We show that this trend of rapidly increasing coal-based emissions is not restricted to a few individual countries such as China. Rather, we are witnessing a global renaissance of coal majorly driven by poor, fast-growing countries that increasingly rely on coal to satisfy their growing energy demand. The low price of coal relative to gas and oil has played an important role in accelerating coal consumption since the end of the 1990s. In this article, we show that in the increasingly integrated global coal market the availability of a domestic coal resource does not have a statistically significant impact on the use of coal and related emissions. These findings have important implications for climate change mitigation: If future economic growth of poor countries is fueled mainly by coal, ambitious mitigation targets very likely will become infeasible. Building new coal power plant capacities will lead to lock-in effects for the next few decades. If that lock-in is to be avoided, international climate policy must find ways to offer viable alternatives to coal for developing countries. PMID:26150491

  4. The Darker Side of the Renaissance

    Directory of Open Access Journals (Sweden)

    Walter Mignolo

    2009-01-01

    Full Text Available The Darker Side of the Renaissance focuses on coloniality rather than on Europe’s witch and alchemist hunt. Today I would dare to say also that this expression refers us to the historical foundation of coloniality. At the same time, coloniality statement is called into question, as well as the distinction between the known object and the knowing subject, an assumption on which the Eurocentric project of “modernity” and “modernization” disciplines lie. The preface marks the enunciation with which the statement is stated. That is, it rejects the "point zero epistemology" denounced by Santiago Castro-Gómez. This means the reader should be always pay attention to the ennunciation s/he states him/herself, to the hand drawing the hand. Those of us dwelling at Abya-Yala/America are surrounded by the historical foundation of modernity/coloniality, we are a living part of that process, which only “scientific” alignment can make us believe we are looking at something (e.g., colonization touching what we are today

  5. Charting a Course for the Infrasound Renaissance

    Science.gov (United States)

    Garces, M.; Bass, H.; Hedlin, M.; Hayward, C.; Bowman, R.; Brown, D.; Businger, S.; Butler, R.; Chouet, B.; Drob, D.; Hetzer, C.; Koyanagi, S.; Mattioli, G.; McCormack, D.; Merrifield, M.; Pack, D.; Swanson, D.; Veith, K.; Voight, B.; Willis, M.

    2003-12-01

    The turn of the 21st century marks the onset of a renaissance in the field of infrasound, which had been dormant for ~30 years. The ongoing deployment of a global infrasound network has reawakened the field to a world of high-resolution digital array data, rapid communication, and seemingly unlimited growth in computing power. Complex phenomena that could only be addressed in general terms three decades ago can now be measured, analyzed, and modeled with unprecedented fidelity. Many fundamental problems in infrasound are now being revisited, and infrasonic observations are being integrated with other technologies (such as seismic, strainmeter and infrared) for the discovery of new phenomena or the refinement of geophysical studies. On July 24-25, 2003, the National Science Foundation sponsored a group of infrasound experts and interdisciplinary researchers to convene in Waikoloa, Hawaii, and chart a course for basic US infrasound research. The conveners selected key projects that would lead to significant advances in our understanding of infrasound generated by effusive and explosive volcanoes, ocean swells, bolides, fauna, severe weather, and long-period atmospheric instabilities. Projects were also proposed to refine our knowledge of atmospheric dynamics and transport mechanisms. A sampling of these projects is discussed in light of their contributions to our fundamental scientific understanding and their impact on the geophysical community.

  6. CONSOLATIONS FOR MELANCHOLY IN RENAISSANCE HUMANISM

    Directory of Open Access Journals (Sweden)

    Angus GOWLAND

    2012-04-01

    Full Text Available This essay explores the role of melancholy within the consolatoryliterature of Renaissance humanism. It begins (sections I-II with a summary of thethemes and methods of humanist consolationes and their classical models, with particularattention to their moral psychology, and addresses their relationship with scripture andChristian spiritual literature. It then turns to the position of melancholy within humanistconsolations (sections III-VI. It is shown that whilst in many cases moralists andspiritual writers were reluctant invade the territory of the physicians by analysing ortreating a fundamentally somatic condition, discussions of the accidentia animi in Galenicmedicine provided the conceptual environment within which a moral-consolatorytherapy for melancholy could be formulated and applied. Here the role of theimagination was crucial: as the primarily affected part in the disease, it was the faculty ofthe soul that was primarily responsible for melancholic passions, but also the faculty thatpresented the physician and moralist with the opportunity to dispel or alleviate thosepassions. Hence, the imagination was at the centre of a moral psychology of melancholy.The final sections of the essay (V-VI show that the fullest implementation of thisapproach to the treatment of melancholy was in Robert Burton’s ‘ConsolatoryDigression’ in The Anatomy of Melancholy (1621, which both synthesises the various moral,spiritual and psychological elements of the humanist consolatory tradition, and contains anumber of idiosyncratic and paradoxical features.

  7. The business opportunities of the nuclear renaissance

    International Nuclear Information System (INIS)

    After 20 years of nuclear moratory, the renaissance of nuclear energy as a primary source for generating electric energy brings important developments for all organizations involved in the Brazilian nuclear sector with different business opportunities throughout the nuclear fuel cycle and nuclear power generation. In Brazil the uranium is found in association with other elements of great commercial value as, for example, the phosphate (agribusiness) and columbite tantalite (computer/communication). The efficiency of the processing and extraction of the elements is associated with the adaptation of technological processes which are appropriate to the genesis of the Brazilian ore. In the manufacture of advanced nuclear fuels, in addition to the new capacities for advanced calculation and designs, skills are necessary for the development of new alloys and materials. The decommissioning of nuclear power plants demands the development of decontamination of materials for the purpose of recycling and reutilization of sites for new use. This document analyzes the role of business opportunities and the future demands in the value chain of nuclear activities. Institutions of R and D and Brazilian universities play a important role for the formation of the new demanded knowledge and human resources. (author)

  8. Overcoming Phase-Transfer Limitations in the Conversion of Lipophilic Oleo Compounds in Aqueous Media-A Thermomorphic Approach.

    Science.gov (United States)

    Gaide, Tom; Dreimann, Jens M; Behr, Arno; Vorholt, Andreas J

    2016-02-01

    A new process concept has been developed for recycling transition-metal catalysts in the synthesis of moderately polar products via aqueous thermomorphic multicomponent solvent systems. This work focuses on the use of "green" solvents (1-butanol and water) in the hydroformylation of the bio-based substrate methyl 10-undecenoate. Following the successful development of a biphasic reaction system on the laboratory scale, the reaction was transferred to a continuously operated miniplant to demonstrate the robustness of this innovative recycling concept for homogenous catalysts. PMID:26822502

  9. Effectively designed molecularly imprinted polymers for selective isolation of the antidiabetic drug metformin and its transformation product guanylurea from aqueous media

    International Nuclear Information System (INIS)

    Highlights: • Preparation of novel MIPs with remarkable recognition properties. • Selective isolation and removal of metformin and guanylurea from aqueous media. • Detailed adsorbent characterization and adsorption studies. • Successful application of synthesized MIPs as dispersive SPE sorbents. • Estimation of expanded uncertainty following a bottom-up approach. - Abstract: In the present study, two novel molecularly imprinted polymers (MIPs) with remarkable recognition properties for metformin and its transformation product, guanylurea, have been prepared for their selective, enrichment, isolation and removal from aqueous media. The prepared adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and swelling experiments. The performance of the prepared MIPs was evaluated by various parameters including the influence of pH, contact time, temperature and initial compound concentration. The effects on the adsorption behavior of the removal process parameters were studied and the equilibrium data were fitted by the Langmuir and Freundlich models. Due to the imprinting effect, adsorption performance of MIPs was always superior to its corresponding NIP (non-imprinted polymer), with maximum adsorption capacity ∼80 mg g−1 for both MIPs. Stability and reusability of the MIPs up to the 5th cycle meant that they could be applied repeatedly without losing substantial removal ability. In the next step, the prepared MIP nanoparticles were evaluated as sorbents in a dispersive solid phase extraction (D-SPE) configuration for selective enrichment and determination of metformin and guanylurea in different aqueous matrices. Under the working extraction conditions, the D-SPE method showed good linearity in the range of 50–1000 ng L−1, repeatability of the extractions (RSD 2.1–5.1%, n = 3), and low limits of detection (1.5–3.4 ng L−1). The expanded uncertainty of the data obtained was estimated

  10. Effectively designed molecularly imprinted polymers for selective isolation of the antidiabetic drug metformin and its transformation product guanylurea from aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Kyzas, George Z.; Nanaki, Stavroula G. [Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Koltsakidou, Anastasia; Papageorgiou, Myrsini; Kechagia, Maria [Laboratory of Environmental Pollution Control, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Bikiaris, Dimitrios N. [Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Lambropoulou, Dimitra A., E-mail: dlambro@chem.auth.gr [Laboratory of Environmental Pollution Control, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece)

    2015-03-25

    Highlights: • Preparation of novel MIPs with remarkable recognition properties. • Selective isolation and removal of metformin and guanylurea from aqueous media. • Detailed adsorbent characterization and adsorption studies. • Successful application of synthesized MIPs as dispersive SPE sorbents. • Estimation of expanded uncertainty following a bottom-up approach. - Abstract: In the present study, two novel molecularly imprinted polymers (MIPs) with remarkable recognition properties for metformin and its transformation product, guanylurea, have been prepared for their selective, enrichment, isolation and removal from aqueous media. The prepared adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and swelling experiments. The performance of the prepared MIPs was evaluated by various parameters including the influence of pH, contact time, temperature and initial compound concentration. The effects on the adsorption behavior of the removal process parameters were studied and the equilibrium data were fitted by the Langmuir and Freundlich models. Due to the imprinting effect, adsorption performance of MIPs was always superior to its corresponding NIP (non-imprinted polymer), with maximum adsorption capacity ∼80 mg g{sup −1} for both MIPs. Stability and reusability of the MIPs up to the 5th cycle meant that they could be applied repeatedly without losing substantial removal ability. In the next step, the prepared MIP nanoparticles were evaluated as sorbents in a dispersive solid phase extraction (D-SPE) configuration for selective enrichment and determination of metformin and guanylurea in different aqueous matrices. Under the working extraction conditions, the D-SPE method showed good linearity in the range of 50–1000 ng L{sup −1}, repeatability of the extractions (RSD 2.1–5.1%, n = 3), and low limits of detection (1.5–3.4 ng L{sup −1}). The expanded uncertainty of the data obtained

  11. Generalized corrosion of nickel base alloys in high temperature aqueous media: a contribution to the comprehension of the mechanisms

    International Nuclear Information System (INIS)

    In France, nickel base alloys, such as alloy 600 and alloy 690, are the materials constituting steam generators (SG) tubes of pressurized water reactors (PWR). The generalized corrosion resulting from the interaction between these alloys and the PWR primary media leads, on the one hand, to the formation of a thin protective oxide scale (∼ 10 nm), and on the other hand, to the release of cations in the primary circuit, which entails an increase of the global radioactivity of this circuit. The goal of this work is to supply some new comprehension elements about nickel base alloys corrosion phenomena in PWR primary media, taking up with underlining the effects of metallurgical and physico-chemical parameters on the nature and the growth mechanisms of the protective oxide scale. In this context, the passive film formed during the exposition of alloys 600, 690 and Ni-30Cr, in conditions simulating the PWR primary media, has been analyzed by a set of characterization techniques (SEM, TEM, PEC and MPEC, XPS). The coupling of these methods leads to a fine description, in terms of nature and structure, of the multilayered oxide forming during the exposition of nickel base alloys in primary media. Thus, the protective part of the oxide scale is composed of a continuous layer of iron and nickel mixed chromite, and Cr2O3 nodules dispersed at the alloy / mixed chromite interface. The study of protective scale growth mechanisms by tracers and markers experiments reveals that the formation of the mixed chromite is the consequence of an anionic mechanism, resulting from short circuits like grain boundaries diffusion. Besides, the impact of alloy surface defects has also been studied, underlining a double effect of this parameter, which influences the short circuits diffusion density in oxide and the formation rate of Cr2O3 nodules. The sum of these results leads to suggest a description of the nickel base alloys corrosion mechanisms in PWR primary media and to tackle some

  12. Effects of self-aggregation on the hydration of an amphiphilic antidepressant drug in different aqueous media

    International Nuclear Information System (INIS)

    Apparent molal volumes and adiabatic compressibilities of aqueous solutions of the amphiphilic antidepressant drug clomipramine hydrochloride have been determined from density and ultrasound velocity measurements in the temperature range 288.15-313.15 K in buffered aqueous solution of pH 3.0 and 5.5. Critical concentrations of aggregation of this drug were obtained from inflections on the plots of the sound velocity against drug concentration. Apparent molal adiabatic compressibilities of the aggregates formed by the drug, calculated by combining the ultrasound velocity and density data, were typical of those for a stacked aggregate. From the temperature dependence of the critical concentration and using the mass action model combined with the Phillips definition of the critical concentration the thermodynamic standard quantities: free Gibbs energy, enthalpy and entropy of aggregate formation were calculated. The critical concentration and energy involved in the aggregation process of this drug have been also evaluated experimentally using isothermal titration calorimetry at 298.15 K. The solvent-drug interactions have been discussed from compressibility and calorimetry data

  13. Copper- or manganese-doped ZnS quantum dots as fluorescent probes for detecting folic acid in aqueous media

    International Nuclear Information System (INIS)

    3-Mercaptopropionic acid-capped core/shell ZnS:Cu/ZnS and ZnS:Mn/ZnS doped quantum dots (QDs) prepared through hydrothermal methods exhibit high photoluminescence intensity as well as good photostability. These water-dispersible nanoparticles exhibit high fluorescence sensitivity to folic acid due to the high affinity of the carboxylate groups and nitrogen atoms of folic acid towards the Zn surface atoms of the doped dots. Quenching of the fluorescence intensity of the QDs allows the detection of folic acid concentrations as low as 11 μM, thus affording a very sensitive system for the sensing of this biologically active molecule in aqueous solution. The possible quenching mechanism is discussed. - Graphical abstract: A sensitive method for the detection of folic acid based on the fluorescence quenching of Mn- or Cu-doped ZnS quantum dots was developed. Highlights: ► Quenching of the fluorescence intensity of doped ZnS QDs in the presence of folic acid. ► New fluorescent sensors for folic acid. ► Detection of folic acid concentrations as low as 11 μM in aqueous solution. ► The Perrin model and fluorescence lifetimes of ZnS:Mn QDs demonstrate a static quenching mechanism. ► Quenching efficiency of ZnS:Cu QDs correlates with the Stern-Volmer model.

  14. Effects of self-aggregation on the hydration of an amphiphilic antidepressant drug in different aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Taboada, Pablo; Gutierrez-Pichel, Manuel; Mosquera, Victor

    2004-03-08

    Apparent molal volumes and adiabatic compressibilities of aqueous solutions of the amphiphilic antidepressant drug clomipramine hydrochloride have been determined from density and ultrasound velocity measurements in the temperature range 288.15-313.15 K in buffered aqueous solution of pH 3.0 and 5.5. Critical concentrations of aggregation of this drug were obtained from inflections on the plots of the sound velocity against drug concentration. Apparent molal adiabatic compressibilities of the aggregates formed by the drug, calculated by combining the ultrasound velocity and density data, were typical of those for a stacked aggregate. From the temperature dependence of the critical concentration and using the mass action model combined with the Phillips definition of the critical concentration the thermodynamic standard quantities: free Gibbs energy, enthalpy and entropy of aggregate formation were calculated. The critical concentration and energy involved in the aggregation process of this drug have been also evaluated experimentally using isothermal titration calorimetry at 298.15 K. The solvent-drug interactions have been discussed from compressibility and calorimetry data.

  15. Photolysis of sulfamethoxypyridazine in various aqueous media: Aerobic biodegradation and identification of photoproducts by LC-UV–MS/MS

    International Nuclear Information System (INIS)

    Highlights: ► Sulfonamides are one of the most extensively used antibiotics in human and veterinary medicine. ► Sulfamethoxypyridazine (SMP) underwent photodegradation in three different media. ► SMP was not readily biodegradable. ► SMP and some of its degradation products were identified by LC-UV–MS/MS. -- Abstract: Sulfonamides are one of the most frequently used antibiotics worldwide. Therefore, mitigation processes such as abiotic or biotic degradation are of interest. Photodegradation and biodegradation are the potentially significant removal mechanisms for pharmaceuticals in aquatic environments. The photolysis of sulfamethoxypyridazine (SMP) using a medium pressure Hg-lamp was evaluated in three different media: Millipore water pH 6.1 (MW), effluent from sewage treatment plant pH 7.6 (STP), and buffered demineralized water pH 7.4 (BDW). Identification of transformation products (TPs) was performed by LC-UV–MS/MS. The biodegradation of SMP using two tests from the OECD series was studied: Closed Bottle test (OECD 301 D), and Manometric Respirometry test (OECD 301 F). In biodegradation tests, it was found that SMP was not readily biodegradable so it may pose a risk to the environment. The results showed that SMP was removed completely within 128 min of irradiation in the three media, and the degradation rate was different for each investigated type of water. However, dissolved organic carbon (DOC) was not removed in BDW and only little DOC removal was observed in MW and STP, thus indicating the formation of TPs. Analysis by LC-UV–MS/MS revealed new TPs formed. The hydroxylation of SMP represents the main photodegradation pathway

  16. Thermodynamical and excess thermoacoustical study on some monosaccharide (glucose) with enzyme amylase in aqueous media at 298.15 K

    Science.gov (United States)

    Nithiyanantham, S.; Palaniappan, L.

    2011-03-01

    Ultrasonic velocity (U), density (ρ) and viscosity (η) measurements have been carried out in three ternary mixtures of glucose with amylase in aqueous medium at 298.15 K. The experimental data have been used to calculate some derived parameters such as acoustical impedance (Z), relative association (RA), Rao's constant (R), Wada's constant (W), relaxation time (τ), relaxation amplitude (α/f2), relaxation strength (r), and some excess thermodynamical properties like excess adiabatic compressibility (βE), excess free length (LfE) excess free volume (VfE), excess internal pressure (πiE) and excess acoustical impedance (ZE). The above parameters have been evaluated and discussed in light of molecular interactions in the mixture.

  17. Iridium Cyclometalated Complexes in Host-Guest Chemistry: A Strategy for Maximizing Quantum Yield in Aqueous Media.

    Science.gov (United States)

    Alrawashdeh, Lubna R; Cronin, Michael P; Woodward, Clifford E; Day, Anthony I; Wallace, Lynne

    2016-07-01

    The weaker emission typically seen for iridium(III) cyclometalated complexes in aqueous medium can be reversed via encapsulation in cucurbit[10]uril (Q[10]). The Q[10] cavity is shown to effectively maximize quantum yields for the complexes, compared to any other medium. This may provide significant advantages for a number of sensor applications. NMR studies show that the complexes are accommodated similarly within the host molecule, even with cationic substituents attached to the ppy ligands, indicating that the hydrophobic effect is the dominant driving force for binding. Cavity-encapsulated 1:1 host-guest species dominate the emission, but 1:2 species are also indicated, which also give some enhancement of intensity. Results demonstrate that the enhancement is due primarily to much lower rates of nonradiative decay but also suggest that the encapsulation can cause a change in character of the emitting state. PMID:27315543

  18. Study of vanadium complex with pyrocatechol violet and 1.10-phenanthroline in aqueous and organic media

    International Nuclear Information System (INIS)

    Spectrophotometrically it has been established that in an aqueous phase in the system of vanadium-pyrocatechol violet (PV)-phenanthroline (Phen) two complexes are formed with the V:PV:Phen ratio equal to 1:1:1 and 1:2:2. The complex with the ration of 1:2:2 is extracted with n-butyl alcohol. Extraction constant of the complex is 8x107. Nolar extinction coefficient of the complex is 1.72x104 (n-butyl alcohol) and 1.39x104 (water). An extraction-photometric method has been developed for determining vanadium in binary aluminium-vanadium alloys with the content of the components of 10 to 90 at.% without preliminary separation of aluminium

  19. Laser-Based Spectroscopic Study on the Speciation of U(VI)-OH Complexes in Aqueous Media

    International Nuclear Information System (INIS)

    Chemical speciation of actinides is fundamental for improving our understanding of their behavior under natural aquatic conditions for the safety assessment of a nuclear waste disposal. In past decades, a number of spectroscopic techniques were developed for the direct speciation of ionic actinide species (hydrated metal ions, hydrolyzed ions and binary or ternary complexes) in an aqueous phase. Conventional absorption spectroscopy by using a UV/VIS spectrophotometer is a useful method for a speciation and most researchers are familiar with this method. But the poor detection sensitivity of a conventional UV/VIS spectrophotometer prevents the speciation of actinides in trace concentrations (-6 M). Therefore laser-based spectroscopic techniques with a much higher detection sensitivity, such as TRLIF (Time-Resolved Laser- Induced-Fluorescence) and LPAS (Laser Photo-acoustic Spectroscopy), have been developed in recent years

  20. Energy dispersive X ray fluorescence with graphite monochromator - uranium and plutonium analyses in aqueous or organic media

    International Nuclear Information System (INIS)

    We describe an energy dispersive X ray fluorescence apparatus equipped with a cylinder graphite monochromator developed in our laboratory. The graphite monochromator is inserted between the sample and the detector, it permits the selection of the fluorescence X radiation from the sample before collection by the Si-Li diode. Hence, the signal versus noise ratio of the fluorescence peak is increased and the limit of detection of our apparatus for uranium is 0.1 mg/l. This apparatus is perfectly adapted for the L rays of all the transuranium elements determinations. We also demonstrate the possibility of determination of uranium or plutonium in either aqueous or organic (TBP) phase. This apparatus is well adapted to control low levels of uranium and plutonium solutions originating from Purex process

  1. Studies on the low Gas-Flow-Rate foam separation of uranium (V I) and thorium (IV) from aqueous media

    International Nuclear Information System (INIS)

    The increasing need to uranium and thorium for nuclear energy programmes has stimulated the development of many methods for their separation both in large amount and in trace. Of these methods, precipitation, ion exchange, adsorption and solvent extraction are the most important. These techniques, though have found much application for the separation of uranium , they their limitations and new methods are, therefore, required for the separation of these elements from aqueous solutions especially when they are present in low concentrations . For this reason, the relatively new techniques: foam separations have been investigated. In foam separation processes, separation occurs by virtue of differences in the surface activity of the substances to be removed. Until about two decades ago, only naturally surface - active substances could be separated by foaming. Metal ions are not naturally surface-active but, lately, it was discovered that foaming could also concentrate inorganic solutions

  2. X-Ray Inactivation of Foot-and-Mouth Disease Virus and Vesicular Stomatitis Virus in Aqueous Media

    International Nuclear Information System (INIS)

    Radiation induced modifications to the biological activities and morphology of viruses are very dependent upon the techniques used in irradiation. Inactivation of foot-and-mouth disease virus and vesicular stomatitis virus by the effects of X-irradiation in dilute aqueous solutions has been studied and the post-irradiation effects and virus sensitization effects are described. Comparisons are made between X-radiation and hydrogen peroxide as virus inactivating agents. Survival curves resulting from these modes of inactivation give information on the reaction kinetics and on the function of the virus protein. Virus morphology, as detected in electron micrographs, is more readily changed by irradiation in solution (indirect effect) than by irradiation of the virus in the frozen state (direct effect). In each case the observed physical changes are related to loss of infectivity and the results are shown to be consistent with the inactivation processes previously inferred. (author)

  3. A Study on Renaissance Humanism’s Positive Ifluences on European Politics

    Institute of Scientific and Technical Information of China (English)

    李丽芳

    2008-01-01

    "Renaissance Humanism"is a very important philosophical and cultural movement in the history of the Middle Ages in Europe.This thesis tries to discuss the positive influences of Renaissance human- ism on European politics.

  4. Reading the Stars of the Renaissance. Fritz Saxl and Astrology

    Directory of Open Access Journals (Sweden)

    Rembrandt Duits

    2011-12-01

    Full Text Available This article discusses Fritz Saxl’s publications on astrological images from the western Middle Ages and Renaissance, from his early study on the representation of the planets (1912, via his catalogues of astrological and mythological manuscripts (1915 and 1927 and his contributions on the depiction of the children of the planets (1919, 1923, 1927 to his booklet on the astrological ceiling in the Villa Farnesina in Rome (1934. It aims to assess the importance of Saxl’s work and to show his development from a close follower of Aby Warburg to an independent theorist, with his own method and approach and his own answer to one of the central issues Warburg had raised – how the integrate the old image of the Renaissance as the revival of classical Antiquity with the new picture of the Renaissance as the birth of the modern rational world presented by Burckhardt during the nineteenth century.

  5. Final report on CCQM-K27.2: Second Subsequent study: determination of ethanol in aqueous media

    Science.gov (United States)

    Schantz, Michele M.; Parris, Reenie M.; May, Willie E.; Rosso, Adriana; Puglisi, Celia; Marques Rodrigues Caixeiro, Janaína; Massiff, Gabriela; Camacho Frías, Evangelina; Pérez Urquiza, Melina; Archer, Marcellé; Visser, M. S.; deVos, Betty-Jayne

    2013-01-01

    Ethanol is important both forensically ('drunk driving' or driving while under the influence, 'DWI', regulations) and commercially (alcoholic beverages). Blood- and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats or snowmobiles, or operators of commercial vehicles like trucks, planes and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances and locality. Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a key comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website. CCQM-K27 comprised three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g) and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS) and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35). A follow-on key comparison, CCQM-K27-Subsequent, was initiated in 2003 to accommodate laboratories that had not been ready to benchmark their methods in the original CCQM-K27 study or that wished to benchmark a different method. Four levels of ethanol in water were used in the

  6. Investigation of the charge-transfer in photo-excited nanoparticles for CO2 reduction in non-aqueous media

    Directory of Open Access Journals (Sweden)

    Dimitrijević Nada M.

    2013-01-01

    Full Text Available Photoinduced charge separation in TiO2 and Cu2O semiconductor nanoparticles was examined using Electron Paramagnetic Resonance spectroscopy in order to get insight into the photocatalytic reduction of CO2 in nonaqueous media. For dissolution/grafting of CO2 we have used carboxy-PEG4-amine, and as a solvent poly(ethylene glycol 200. We have found that, in this system, reduction of CO2 starts at potential of -0.5 V vs Ag/AgCl, which is significantly more positive than the potential for electrochemical reduction of CO2 in most organic solvents and water (-2.0 V vs. Ag/AgCl. The electron transfer from excited nanoparticles to CO2 is governed both by thermodynamic and kinetic parameters, namely by the redox potential of conduction band electrons and adsorption/binding of CO2 on the surface of nanoparticles.

  7. A PEGylated fluorescent turn-on sensor for detecting fluoride ions in totally aqueous media and its imaging in live cells.

    Science.gov (United States)

    Zheng, Fangyuan; Zeng, Fang; Yu, Changmin; Hou, Xianfeng; Wu, Shuizhu

    2013-01-14

    Owing to the considerable significance of fluoride anions for health and environmental issues, it is of great importance to develop methods that can rapidly, sensitively and selectively detect the fluoride anion in aqueous media and biological samples. Herein, we demonstrate a robust fluorescent turn-on sensor for detecting the fluoride ion in a totally aqueous solution. In this study, a biocompatible hydrophilic polymer poly(ethylene glycol) (PEG) is incorporated into the sensing system to ensure water solubility and to enhance biocompatibility. tert-Butyldiphenylsilyl (TBDPS) groups were then covalently introduced onto the fluorescein moiety, which effectively quenched the fluorescence of the sensor. Upon addition of fluoride ion, the selective fluoride-mediated cleavage of the Si-O bond leads to the recovery of the fluorescein moiety, resulting in a dramatic increase in fluorescence intensity under visible light excitation. The sensor is responsive and highly selective for the fluoride anion over other common anions; it also exhibits a very low detection limit of 19 ppb. In addition, this sensor is operative in some real samples such as running water, urine, and serum and can accurately detect fluoride ions in these samples. The cytotoxicity of the sensor was determined to be Grade I toxicity according to United States Pharmacopoeia and ISO 10993-5, suggesting the very low cytotoxicity of the sensor. Moreover, it was found that the senor could be readily internalized by both HeLa and L929 cells and the sensor could be utilized to track fluoride level changes inside the cells. PMID:23197478

  8. NEO-RENAISSANCE AND REVITALIZATION OF VOTIC – WHO CARES?

    OpenAIRE

    Margit Kuusk; Heinike Heinsoo

    2011-01-01

    The paper deals with the reason for the decline of the Votic language and neo-renaissance and revitalization of the Votic.The reason for the decline of the Votic language are the small number of people, traditionally sparse population and the assimilation – the speakers of Votic have always lived in the sphere of influence of the Russian language and culture. The reasons for neo-renaissance are the collapse of the Soviet Union, a general trend to look for one’s roots, enthusiastic votophiles ...

  9. Recoverable and recyclable water-soluble sulphonated salicylaldimine Rh(I) complexes for 1-octene hydroformylation in aqueous biphasic media.

    Science.gov (United States)

    Matsinha, Leah C; Mapolie, Selwyn F; Smith, Gregory S

    2015-01-21

    A series of water-soluble Rh(i) mononuclear complexes of general formula: [Rh(sulphsal-X-R)(COD)] [sulphsal = sulphonated salicylaldimine, COD = cyclooctadiene; where R = H, Cl, CH3 and X = H, (t)Bu] have been synthesized. All the compounds were characterised using various spectroscopic and analytical techniques such as nuclear magnetic resonance spectroscopy, infrared spectroscopy, single crystal X-ray diffraction (for complex ) and mass spectrometry. All the compounds display excellent water-solubility at room temperature and were tested as catalyst precursors in the aqueous biphasic hydroformylation of 1-octene. The catalysts could be easily recovered by phase separation and were used up to 5 times without any significant loss in activity and 1-octene conversion. Very high yields of the expected aldehydes were obtained without addition of any phase transfer agents, co-solvents or hydrophobic ligands. Excellent aldehyde chemoselectivity is observed for all the catalysts but this varied each time the catalysts were recycled, with the formation of a small amount of internal olefins. ICP-OES and mercury poisoning experiments show that a combination of homogeneous catalysis and catalysis mediated by nanoparticles is taking place in these systems. PMID:25415263

  10. Development of basic data for modelling the residual alteration rate in aqueous media of AVM nuclear glasses

    International Nuclear Information System (INIS)

    During their aqueous alteration, AVM French nuclear glasses exhibit a large range of behaviour, in spite of a small range of composition. AVM glasses alteration rates are controlled by two phenomena: (i) precipitation of secondary phases, mostly aluminous hectorites, and (ii) diffusion of water across a more or less protective gel. The magnesium contained in these glasses increases the precipitation of these secondary phases, leading to a partial or total dissolution of the gel layer. This dissolution increases the glass alteration rates. On the other hand, Mg also incorporates in the gel, increasing his passivation properties. The predominance of one of these two phenomena depends on the initial composition of the glass, the pH of the solution, and the alteration conditions. In presence of Bure geological disposal site water (Mg and Ca rich), AVM glasses undergo less alteration than in initially pure water, in spite of larger amounts of secondary phase precipitates. This results from incorporation of calcium in the gel instead of sodium and magnesium, improving its passivating properties. We have adapted the geochemical GRAAL model for AVM glasses. In spite of its limitations, this model allows us to describe the differences of behaviour between these glasses, in function of their composition. Moreover, GRAAL can be proposed as a basis of a future operational model for predicting the alteration of AVM glasses. (author)

  11. Lignin-assisted exfoliation of molybdenum disulfide in aqueous media and its application in lithium ion batteries.

    Science.gov (United States)

    Liu, Wanshuang; Zhao, Chenyang; Zhou, Rui; Zhou, Dan; Liu, Zhaolin; Lu, Xuehong

    2015-06-01

    In this article, alkali lignin (AL)-assisted direct exfoliation of MoS2 mineral into single-layer and few-layer nanosheets in water is reported for the first time. Under optimized conditions, the concentration of MoS2 nanosheets in the obtained dispersion can be as high as 1.75 ± 0.08 mg mL(-1), which is much higher than the typical reported concentrations (MoS2 nanosheets are applied as electrode materials for lithium ion batteries, they show much improved electrochemical performance compared with the pristine MoS2 mineral because of the enhanced ion and electron transfer kinetics. This facile, scalable and eco-friendly aqueous-based process in combination with renewable and ultra-low-cost lignin opens up possibilities for large-scale fabrication of MoS2-based nanocomposites and devices. Moreover, herein we demonstrate that AL is also an excellent surfactant for exfoliation of many other types of layered materials, including graphene, tungsten disulfide and boron nitride, in water, providing rich opportunities for a wider range of applications. PMID:25970569

  12. Synthesis of Poly(methacrylic acid)-functionalized SBA-15 and its Adsorption of Phenol in Aqueous Media

    International Nuclear Information System (INIS)

    Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and N2 adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied

  13. ROD-LIKE AGGREGATES FROM POLYSTYRENE-b-POLY(4-VINYLPYRIDINE)-b-POLYSTYRENE TRIBLOCK COPOLYMER IN AQUEOUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    Jian-jun Yuan; Rui Ma; Xiao-qin Li; Ke Zhuang; Shi-yuan Cheng; Lei Jiang; Lin-xian Feng; Zhi-qiang Fan

    2004-01-01

    The rod-like assembly from BAB block copolymer with hydrophilic middle block A in aqueous solution was described. The copolymer used is polystyrene (PS)39-b-poly(4-vinylpyridine)(P4VP)98-b-PS39 (the subscripts are the average polymerization degree of corresponding blocks) triblock copolymer with Mw/Mn = 1.15. The aggregates were characterized by transmission electron microscopy and atomic force microscopy. The dependence of rod-like aggregate formation on solvents, pH, and polymer concentrations was investigated. The rod-like aggregates were formed when using dioxane as initial solvent, while spherical micelles were formed using DMF. Elevating pH values from 4 to 5 to 7 and decreasing initial copolymer concentrations from 1.5 wt% to 1.0 wt% to 0.5 wt% were favorable for the formation of well-defined rod-like aggregates. In addition, the bicontinuous rods and lamellae were observed when preparing colloid solutions in appropriate conditions.

  14. Techniques and Protocols for Dispersing Nanoparticle Powders in Aqueous Media-Is there a Rationale for Harmonization?

    Science.gov (United States)

    Hartmann, Nanna B; Jensen, Keld Alstrup; Baun, Anders; Rasmussen, Kirsten; Rauscher, Hubert; Tantra, Ratna; Cupi, Denisa; Gilliland, Douglas; Pianella, Francesca; Riego Sintes, Juan M

    2015-01-01

    Selecting appropriate ways of bringing engineered nanoparticles (ENP) into aqueous dispersion is a main obstacle for testing, and thus for understanding and evaluating, their potential adverse effects to the environment and human health. Using different methods to prepare (stock) dispersions of the same ENP may be a source of variation in the toxicity measured. Harmonization and standardization of dispersion methods applied in mammalian and ecotoxicity testing are needed to ensure a comparable data quality and to minimize test artifacts produced by modifications of ENP during the dispersion preparation process. Such harmonization and standardization will also enhance comparability among tests, labs, and studies on different types of ENP. The scope of this review was to critically discuss the essential parameters in dispersion protocols for ENP. The parameters are identified from individual scientific studies and from consensus reached in larger scale research projects and international organizations. A step-wise approach is proposed to develop tailored dispersion protocols for ecotoxicological and mammalian toxicological testing of ENP. The recommendations of this analysis may serve as a guide to researchers, companies, and regulators when selecting, developing, and evaluating the appropriateness of dispersion methods applied in mammalian and ecotoxicity testing. However, additional experimentation is needed to further document the protocol parameters and investigate to what extent different stock dispersion methods affect ecotoxicological and mammalian toxicological responses of ENP. PMID:26397955

  15. Visible Light Induced Enhanced Photocatalytic Degradation of Industrial Effluents (Rhodamine B in Aqueous Media Using TiO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    J. O. Carneiro

    2016-01-01

    Full Text Available In recent years, new textile materials have been developed through the use of nanotechnology-based tools. The development of textile surfaces with self-cleaning properties has a large combined potential to reduce the environmental impact related to pollution. In this research work, three types of textiles substrates (cotton, Entretela, and polylactic acid (PLA were functionalized with titanium dioxide nanoparticles (TiO2 using chemical and mechanical processes (padding. During the functionalization process, two different methods were used, both of which allowed a good fixation of nanoparticles of TiO2 on textile substrates. The samples were examined for morphology and for photocatalytic properties under visible light irradiation. A study aimed at evaluating the effect of pH of the aqueous solution of TiO2 nanoparticles was performed in order to promote interaction between TiO2 and the dye solution rhodamine B (Rh-B. The TiO2 nanoparticles were characterized by X-ray diffraction (XRD. The measurement of the zeta potential of the TiO2 nanoparticle solution proved to be always positive and have low colloidal stability. Chromatography (HPLC and GC-MS analyses confirm that oxalic acid is the intermediate compound formed during the photodegradation process.

  16. Modification of magadiite surface by organofunctionalization for application in removing As(V) from aqueous media: Kinetic and thermodynamic

    International Nuclear Information System (INIS)

    A synthetic Na-magadiite sample has been modified by organofunctionalization process using synthetic route involved the reaction of 2-mercaptopyrimidine with 3-chloropropyltriethoxysilane. The ability of these materials to remove As(V) from aqueous solution was followed by a series of adsorption isotherms adjusted to the Langmuir equation at room temperature and pH 2.0. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second-order reaction with k2 in the 4.9-14.0 mmol-1 min-1 range for MMPY. The adsorption process was exothermic (ΔintH = -4.09 to -5.79 kJ mol-1) accompanied by increase in entropy (ΔintS = 41.29-61.80 J K-1 mol-1) and Gibbs energy (ΔintG = -22.34 to -24.19 kJ mol-1). The energetic effect caused by arsenic(V) cation adsorption was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.

  17. Synthesis of Poly(methacrylic acid)-functionalized SBA-15 and its Adsorption of Phenol in Aqueous Media

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Vien; Kim, Heejun; Kim, Hayeong; Kim, Youngmee; Kim, Sung Jin [Ewha Womans Univ., Seoul (Korea, Republic of)

    2013-12-15

    Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and N{sub 2} adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

  18. Radioactive waste management and the nuclear renaissance

    International Nuclear Information System (INIS)

    Full text: Full text: For many years, nuclear supporters have been talking of a possible nuclear power renaissance. Today there are definite signs that this is finally beginning to happen. New plants are being built or planned in China, Japan, Korea, Finland, France and even the USA. Phase-out policies are being rethought in countries like Sweden, Belgium and Germany. Countries like Vietnam, Indonesia, the Baltic States and even Australia are choosing or debating initiating a nuclear programme. Support for these nuclear power developments may be strongly influenced by the progress of waste management programmes, especially final disposal. Conversely, the growing realisation of the potential global benefits of nuclear power may well lead to increased support, effort and funding for initiatives to ensure that all nations have access to safe and secure waste management facilities. This implies that large nuclear programmes must make progress with implementation of treatment, storage and disposal facilities for all of their radioactive wastes. For small nuclear programmes (and for countries with nuclear applications other than power generation) such facilities are also necessary. For economic and other reasons, these small programmes may not be able to implement all of the required national facilities. Multinational cooperation is needed. This can be realised by large countries providing back-end services such as reprocessing and disposal, or by small countries forming regional or international partnerships to implement shared facilities for storage and/or disposal. This paper will trace through the past decades the mutual interactions between programmes in nuclear power and in waste management. The relevant issues of concern for both include radiological safety, environmental impacts and, most topically, non-proliferation and security. Debates on these issues have strongly affected national efforts to implement power plants and repositories, and also influenced the

  19. Bracing up for a global nuclear renaissance

    International Nuclear Information System (INIS)

    The nuclear new build market is dynamic: the nuclear renaissance is here. The challenge facing today the nuclear industry is to meet this strong demand: design and build new reactors..... and ensure an adequate fuel supply for the existing reactors and the new ones. AREVA is getting ready to meet those needs. To answer in the best possible way the call of several new customers, and to make the necessary investments AREVA has made the choice of complementing its own strength with new alliances. When it was created, AREVA has set a new model: an integrated group capable of supplying all parts of the nuclear cycle, from Uranium mining to reactor design construction and servicing, and then up to used fuel management and recycling. This merger of reactor activities and fuel cycle services has proved successful. Focused acquisitions have further strengthened our own capabilities. In addition, AREVA has set-up several alliances to further develop the nuclear market. In the United States, AREVA joined forces with the US utility Constellation to create Uni Star to promoting the EPR. Today, several US utilities are choosing the AREVA's US-EPR. They will benefit from the experience gained in licensing and building the EPR in Finland, in France and soon in China. And they will benefit of course from the unique features of the EPR: easier maintenance, shorter outage, enhanced safety. Willing to meet the growing demand of countries launching a new nuclear program, AREVA set up an alliance with MHI to design a mid-size reactor, ATEMEA 1. Such an alliance allows to speed-up time to market of this new product, which will offer the latest available technologies. In the fuel cycle, AREVA has also developed acquisitions and alliances. As an example, thanks to such an alliance, the new enrichment plant GB-2, could get access to the most efficient centrifugation process. In this fast growing global market, at AREVA we believe into the value of collaboration and partnership to best serve

  20. Effect of aqueous media on the copper-ion-mediated phototoxicity of CuO nanoparticles toward green fluorescent protein-expressing Escherichia coli.

    Science.gov (United States)

    Shang, Enxiang; Li, Yang; Niu, Junfeng; Guo, Huiyuan; Zhou, Yijing; Liu, Han; Zhang, Xinqi

    2015-12-01

    Quantitative comparison of different aqueous media on the phototoxicity of copper oxide nanoparticles (CuO NPs) is crucial for understanding their ecological effects. In this study, the phototoxicity of CuO NPs toward the green fluorescent protein-expressing Escherichia coli (GFP-E. coli) under UV irradiation (365 nm) was investigated in Luria-Bertani medium (LB), NaCl solution, deionized water (DI) and phosphate-buffered saline (PBS). The phototoxicity of CuO NPs toward GFP-E. coli decreased in the order of DI>NaCl>PBS>LB because of different released concentrations of Cu(2+). The 3h released Cu(2+) concentrations by 10mg/L CuO NPs in DI water, NaCl solution, LB medium, and PBS were 1946.3 ± 75.6, 1242.5 ± 47.6, 1023.4 ± 41.2, and 1162.1 ± 41.9 μg/L, respectively. Transmission electron microscope and laser scanning confocal microscope images of E. coli exposed to CuO NPs demonstrated that the released Cu(2+) resulted in fragmentation of bacterial cell walls, leakage of intracellular components, and finally death of bacteria in four media after UV light irradiation. In each medium, the bacterial mortality rate logarithmically increased with the releasing concentrations of Cu(2+) by CuO NPs (R(2)>0.90) exposed to 3h UV light. This study highlights the importance of taking into consideration of water chemistry when the phototoxicity of CuO NPs is assessed in nanotoxicity research. PMID:26283288

  1. Studies on the extraction behaviour of plutonium(IV) from mixed aqueous-organic media with sulphoxides

    International Nuclear Information System (INIS)

    The extraction behaviour of plutonium (IV) from nitric acid media by two long-chain aliphatic sulfoxides, namely, di-n-hexylsulfoxide and di-n-octylsulfoxide has been investigated in the presence of several water-miscible organic solvents to study their possible synergistic effect on metal ion extraction. Methanol, ethanol, n- and iso-proparnol, dioxane, acetone as well as acetonitrile were used as the organic component of the mixed (polar) phase. These additives affected the extraction to varying degrees. Thus the extractability of Pu increases 2-3 fold with increasing concentration (up to 20%) of acetonitrile, acetone, methanol and ethanol while it decreases with increasing concentration of n- and iso-propanol. At high concentration of the former, synergism changes into antagonism. Possible reasons for such behaviour are briefly discussed. Among these organic additives, the maximum enhancement in the extraction of Pu(IV) was observed in the presence of acetonitrile. The relative increase in extraction was found to be more at lower sulfoxide concentrations. (author)

  2. Dye-sensitized solar cells based on thick highly ordered TiO2 nanotubes produced by controlled anodic oxidation in non-aqueous electrolytic media

    International Nuclear Information System (INIS)

    Dye-sensitized solar cells (DSSCs) were prepared using TiO2 nanotubes, grown by controlled Ti anodic oxidation in non-aqueous media. Smooth, vertically oriented TiO2 nanotube arrays, presenting a high degree of self-organization and a length of 20 μm, have been grown using ethylene glycol electrolyte containing HF. As-grown nanotubes exhibit an amorphous structure, which transforms to the anatase TiO2 crystalline phase upon post-annealing in air at 450 deg. C. Atomic force microscopy (AFM) revealed the porous morphology together with high roughness and fractality of the surface. The annealed tubes were sensitized by the standard N719 ruthenium dye and the adsorption was characterized using resonance micro-Raman spectroscopy and adsorption-desorption measurements. The sensitized tubes were further used as active photoelectrodes after incorporation in sandwich-type DSSCs using both liquid and solidified electrolytes. The efficiencies obtained under air mass (AM) 1.5 conditions, using a back-side illumination geometry, were very promising: 0.85% using a composite polymer redox electrolyte, while the efficiency was further increased up to 1.65% using a liquid electrolyte

  3. Preparation of hybrid organic-inorganic mesoporous silicas applied to mercury removal from aqueous media: Influence of the synthesis route on adsorption capacity and efficiency.

    Science.gov (United States)

    Pérez-Quintanilla, Damián; Sánchez, Alfredo; Sierra, Isabel

    2016-06-15

    New hybrid organic-inorganic mesoporous silicas were prepared by employing three different synthesis routes and mercury adsorption studies were done in aqueous media using the batch technique. The organic ligands employed for the functionalization were derivatives of 2-mercaptopyrimidine or 2-mercaptothiazoline, and the synthesis pathways used were post-synthesis, post-synthesis with surface ion-imprinting and co-condensation with ion-imprinting. The incorporation of functional groups and the presence of ordered mesopores in the organosilicas was confirmed by XRD, TEM and SEM, nitrogen adsorption-desorption isotherms, (13)C MAS-NMR, (29)Si MAS-NMR, elemental and thermogravimetric analysis. The highest adsorption capacity and selectivity observed was for the material functionalized with 2-mercaptothiazoline ligand by means the co-condensation with ion-imprinting route (1.03mmolg(-1) at pH 6). The prepared material could be potential sorbent for the extraction of this heavy metal from environmental and drinking waters. PMID:27023632

  4. Chemical enrichment and separation of uranyl ions in aqueous media using novel polyurethane foam chemically grafted with different basic dyestuff sorbents.

    Science.gov (United States)

    El-Shahat, M F; Moawed, E A; Farag, A B

    2007-01-15

    The new type of the grafted polyurethane foam sorbents were prepared by coupling polyether polyol, toluene diisocyanate and basic dyestuff (Methylene blue, Rhodamine B and Brilliant green). The Me.B-PUF, Rh.B-PUF and Br.G-PUF were characterized using UV/vis, IR and TGA. The adsorption properties and chromatographic behaviour of these new adsorbents for preconcentration and separation of uranium(VI) ions at low concentrations from aqueous thiocyanate media were investigated by a batch process. The maximum sorption of U(VI) was in the pH ranges 1-4. The kinetics of sorption of the U(VI) by the Grafted-PUF were found to be fast with half life of sorption (t(1/2)) in 2.43min. The average sorption capacity of different sorbents 0.124meqg(-1) for uranyl ions, enrichment factors approximately 40 and the recovery 98-100% were achieved (R.S.D. approximately 0.73%). The basic dyestuff Grafted-PUF could be used many times without decreasing their capacities significantly. The value of the Gibbs free energy (DeltaG) for the sorbents is -7.3kJmol(-1), which reflects the spontaneous nature of sorption process. The sorption mechanism of the metal ion onto Grafted-PUF was also discussed. PMID:19071294

  5. Sono-assisted photocatalytic degradation of styrene-acrylic acid copolymer in aqueous media with nano titania particles and kinetic studies.

    Science.gov (United States)

    Saien, J; Delavari, H; Solymani, A R

    2010-05-15

    The ultrasonic irradiation (28 kHz, 50 W) in pre-cavitations regime was employed to enhance the degradation rate of styrene-acrylic acid copolymer in aqueous media with nano titania photocatalyst particles. A stainless steel cylindrical sono-photo reactor with capacity of about 1.25 L, equipped with a UV lamp (250 W) was used. The influence of operational parameters, i.e. catalyst concentration, pH and temperature was studied and the role of active species was also distinguished. For an initial substrate concentration of 30 mg L(-1), under mild applied conditions of 30 mg L(-1) of photocatalyst, 25 degrees C and natural pH, a degradation and mineralization conversion of 96% and 91%, respectively, was achieved using sono-assisted photocatalysis process in about only 60 min. These efficiencies are much higher than those obtained with only photocatalysis process. Meanwhile, the threshold of cavitations was found corresponded to catalyst concentration of about 70 mg L(-1). Kinetic studies based on Langmuir-Hinshelwood and power law models in addition to the results from radical scavenger usage revealed that for sono-assisted process, the substrate undergoes degradation mainly via electron-hole redox on the surface of titania particles. It is while for the only photocatalysis process, the reaction proceeds via hydroxyl radicals in the solution bulk. PMID:20092940

  6. Treatment of aqueous outflows by complexation in micellar media and precipitation with a sol-gel process

    International Nuclear Information System (INIS)

    Being able to deal with aqueous outflows from treatment sites in the Hague is a major environmental issue. These outflows are contaminated with organic substances and elements with residual radioactivity. This work deals with the development and optimization of the process of de-polluting, and we aim at removing all pollution from the outflow, and produce a final waste compatible with traditional conditioning matrices in the nuclear area. The separation process consists of two steps: dissolving the pollution in the surfactants micelles, and precipitating a mineral phase via sol-gel transition. Within this thesis, only pollution originating from radionuclides is studied. During the first step, our strategy is to use complexing molecules able to interact with ions and to form mainly solvable complexes at the core of surfactant micelles. Thereafter, the second step consisted to add silica precursor which, after hydrolyse and polycondensation, makes it possible to aggregate those micelles that contain complexes together, and to form a silica phase which precipitates in an in-situ fashion. The goal to de-pollute the outflow was achieved, and the final waste thus produced is a silica powder that contains the micelles and the pollution which, after calcination, is compatible with conditioning matrices such as glass or concrete. A reference system for which the separation process is optimal was defined throughout various studies. This system contains a non-ionic surfactant (P123), an ion that surrogates radionuclides (neodymium), a complexing agent (HDEHP) and a silica precursor (TEOS). Hence, this system was further studied in order to broaden the application scope of the separation process, as well as to understand the mechanisms involved, during the complexation of the ions and the micellar solubilization and during the formation of the silica powder. This study was performed using diffusion, imaging and spectrometry techniques.To conclude, the alternative de

  7. The Poetry of Titian’s "Poesie": The Renaissance View

    Czech Academy of Sciences Publication Activity Database

    Konečný, Lubomír

    Szeged: JATEPress, 2012 - (Szönyi, G.; Maczelka, C.), s. 223-230 ISBN 978-963-315-079-5. [Renaissance and Renascences. Conference of East-Central European Mellon Fellows. Szeged (HU), 10.07.2003-13.07.2003] Institutional research plan: CEZ:AV0Z80330511 Keywords : Titian * mythology * poetry Subject RIV: AL - Art, Architecture, Cultural Heritage

  8. Rediscovering Renaissance Research: Information Literacy Strategies for Success

    Science.gov (United States)

    Gilchrist, Sarah Burns

    2016-01-01

    While remaining cognizant of several aspects of current information literacy (IL) instruction methods, including threshold concepts, the author re-created experiences shared by students as she searched for, analyzed, and compiled resources pertaining to the Renaissance. Good IL instruction supports education of the whole person, develops new modes…

  9. The 4th Century BC 'Ionian Renaissance' and Karian Identity

    DEFF Research Database (Denmark)

    Pedersen, Poul

    2013-01-01

    , arkaiske kultur. Der argumenteres for, at der nok skete en opblomstring af den lokale kariske kultur, men at den genoplivede, arkaiske, græske kultur var det vigtigste, overordnede træk i Den ioniske Renaissance og at dette kom til at præge den arkaiske og klassisk græske kulturs efterliv i hellenistisk og...

  10. Nuclear Operations Excellence: A Foundation for the Renaissance

    International Nuclear Information System (INIS)

    The world is poised for a nuclear power renaissance. Countries with dormant or phased-out nuclear energy programs are reactivating their plans for building a new generation of safe and economical nuclear plants. Countries with no nuclear programs are actively working to establish them. The renaissance is being driven by a variety of factors, foremost of which are instabilities in the cost and supply of oil and gas, and increasing political pressures to prevent continued global warming as a result of the use of fossil fuels. Nuclear is now seen as a necessary component of a renewable, non-carbon producing energy portfolio along with hydro, wind and solar. So what is required to turn these plans into reality? Most observers, both inside and outside of the industry would agree that the foundation of the renaissance is first and foremost the continued safe and economical operation of the world's existing 436 reactors in 30 countries. Although operating experience varies across existing reactors, it can be confidently said that since the accident at Chernobyl, the vast majority of the world's reactor operators have demonstrated continuous improvements in plant operations. If however, another Chernobyl or TMI type accident were to occur, it would have a devastating impact on nuclear programs all over the world, and seriously jeopardize the plans for a nuclear renaissance for many years to come. Given the premise that continuing improvements in plant operations, or nuclear operations excellence, is a necessary first step in creating a sustained renaissance, what exactly is nuclear operations excellence, how is it measured, how is it achieved, and what are the requirements for the next generation of plants to be built? This paper will attempt to answer these questions, first in a broad sense based upon the 50+ years of combined nuclear industry experience of the authors, and also in a more focused exploration of information technology tools that are supporting the current

  11. Jean-Pierre Luminet: Renaissance Communicator

    Science.gov (United States)

    Pullen, L.; Russo, P.

    2009-02-01

    As science communicators dealing with astronomy we often find a strong interest amongst the public in astrology - how the stars and planets directly affect our individual lives. Nowadays astrology is at odds with the scientific nature of astronomy, but this has not always been the case. Presented here is a background to astrology, to give a deeper understanding of where it has come from and why it has such an enduring place in all forms of global media.

  12. Pyrene and imidazole functionalized luminescent bimetallic Ru(II) terpyridine complexes as efficient optical chemosensors for cyanide in aqueous, organic and solid media.

    Science.gov (United States)

    Karmakar, Srikanta; Maity, Dinesh; Mardanya, Sourav; Baitalik, Sujoy

    2015-11-14

    We report in this work the anion recognition and sensing aspect of a new family of bimetallic Ru(ii) complexes derived from a symmetrical bridging 5,11-bis(4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)-4,12-dihydropyreno[4,5-d:9,10-d']diimidazole (tpy-H2PhImzPy-tpy) terpyridine ligand in solution as well as in the solid sate through different channels such as absorption, steady state and time-resolved emission, and (1)H NMR spectroscopic techniques. Interestingly, the complexes exhibit luminescence in the red region with moderately long lifetimes compared with the related terpyridine complexes of Ru(ii). In DMSO, complexes 1 and 2 act as sensors for F(-) and to a lesser extent for AcO(-), CN(-) and H2PO4(-), whereas 3 acts as a sensor for F(-), AcO(-), CN(-) and to some extent for H2PO4(-). In contrast to DMSO, all the complexes exhibit very high selectivity towards cyanide ions in the presence of an excess of other anions in aqueous medium. The complexes display visual detection of cyanide with the detection limit lying in the range of 1.01 × 10(-7) to 9.79 × 10(-8) M. Equilibrium constants for the interaction of the complexes with the anions were evaluated from absorption and emission titration profiles and were found to lie in six orders of magnitude. It is observed that the excited-state lifetimes of the complexes were modulated to a significant extent by the selected anions in all the three media proving the utility of such complexes to act as lifetime-based sensors for anions. The fact that all the complexes can selectively sense cyanide in the presence of other anions with their detection limits lying in the range of 10(-7) M-10(-8) M in aqueous solution is particularly important for their practical applicability. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) studies were performed to understand the nature of the ground and excited states of the complexes with detailed assignments of the orbitals involved in absorption

  13. New Insight into the Cosmic Renaissance Epoch

    Science.gov (United States)

    2003-08-01

    VLT Discovers a Group of Early Inhabitants and Find Signs of Many More [1] Summary Using the ESO Very Large Telescope (VLT) , two astronomers from Germany and the UK [2] have discovered some of the most distant galaxies ever seen . They are located about 12,600 million light-years away. It has taken the light now recorded by the VLT about nine-tenths of the age of the Universe to traverse this huge distance. We therefore observe those galaxies as they were at a time when the Universe was very young, less than about 10% of its present age . At this time, the Universe was emerging from a long period known as the "Dark Ages" , entering the luminous "Cosmic Renaissance" epoch. Unlike previous studies which resulted in the discovery of a few, widely dispersed galaxies at this early epoch, the present study found at least six remote citizens within a small sky area, less than five per cent the size of the full moon! This allowed understanding the evolution of these galaxies and how they affect the state of the Universe in its youth. In particular, the astronomers conclude on the basis of their unique data that there were considerably fewer luminous galaxies in the Universe at this early stage than 500 million years later. There must therefore be many less luminous galaxies in the region of space that they studied, too faint to be detected in this study. It must be those still unidentified galaxies that emit the majority of the energetic photons needed to ionise the hydrogen in the Universe at that particularly epoch. PR Photo 25a/03 : Colour-composite of the sky field with the distant galaxies. PR Photo 25b/03 : Close-Up images of some of the most distant galaxies known in the Universe. PR Photo 25c/03 : Spectra of these galaxies. From the Big Bang to the Cosmic Renaissance Nowadays, the Universe is pervaded by energetic ultraviolet radiation, produced by quasars and hot stars. The short-wavelength photons liberate electrons from the hydrogen atoms that make up the

  14. BOOK REVIEW: Galileo's Muse: Renaissance Mathematics and the Arts

    Science.gov (United States)

    Peterson, Mark; Sterken, Christiaan

    2013-12-01

    Galileo's Muse is a book that focuses on the life and thought of Galileo Galilei. The Prologue consists of a first chapter on Galileo the humanist and deals with Galileo's influence on his student Vincenzo Viviani (who wrote a biography of Galileo). This introductory chapter is followed by a very nice chapter that describes the classical legacy: Pythagoreanism and Platonism, Euclid and Archimedes, and Plutarch and Ptolemy. The author explicates the distinction between Greek and Roman contributions to the classical legacy, an explanation that is crucial for understanding Galileo and Renaissance mathematics. The following eleven chapters of this book arranged in a kind of quadrivium, viz., Poetry, Painting, Music, Architecture present arguments to support the author's thesis that the driver for Galileo's genius was not Renaissance science as is generally accepted but Renaissance arts brought forth by poets, painters, musicians, and architects. These four sets of chapters describe the underlying mathematics in poetry, visual arts, music and architecture. Likewise, Peterson stresses the impact of the philosophical overtones present in geometry, but absent in algebra and its equations. Basically, the author writes about Galileo, while trying to ignore the Copernican controversy, which he sees as distracting attention from Galileo's scientific legacy. As such, his story deviates from the standard myth on Galileo. But the book also looks at other eminent characters, such as Galileo's father Vincenzo (who cultivated music and music theory), the painter Piero della Francesca (who featured elaborate perspectives in his work), Dante Alighieri (author of the Divina Commedia), Filippo Brunelleschi (who engineered the dome of the Basilica di Santa Maria del Fiore in Florence, Johannes Kepler (a strong supporter of Galileo's Copernicanism), etc. This book is very well documented: it offers, for each chapter, a wide selection of excellent biographical notes, and includes a fine

  15. Optimization, isotherm, kinetic and thermodynamic studies of Pb(II) ions adsorption onto N-maleated chitosan-immobilized TiO2 nanoparticles from aqueous media

    Science.gov (United States)

    Shaker, Medhat A.; Yakout, Amr A.

    2016-02-01

    Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51 ± 3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, 1H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r2) and non-linear Chi-square (χ2) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters.

  16. Optimization, isotherm, kinetic and thermodynamic studies of Pb(II) ions adsorption onto N-maleated chitosan-immobilized TiO₂ nanoparticles from aqueous media.

    Science.gov (United States)

    Shaker, Medhat A; Yakout, Amr A

    2016-02-01

    Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51±3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, (1)H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r(2)) and non-linear Chi-square (χ(2)) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters. PMID:26520475

  17. “Turn on/off” proton transfer based fluorescent sensor for selective detection of environmentally hazardous metal ions (Zn2+, Pb2+) in aqueous media

    International Nuclear Information System (INIS)

    Sensing ability of fluorescence based chemosensor: Indole-7-carboxaldehyde (I7C) for environmentally hazardous metal ions (Xn+=Zn2+, Pb2+, Co2+, Ni2+, Cu2+, Cd2+, Cr3+, and Fe3+) has been investigated. Based on excited state proton transfer (ESPT) phenomenon, the sensing capability of I7C is verified experimentally (UV–vis, FTIR, NMR) and theoretically (DFT, TD-DFT) in aqueous media. Chemical hardness (η), electrophilicity (ω) and electronic chemical potentials (μ) confirm the selective reactivity of I7C (Nc and Nt conformers) in the presence of metal ions by the formation of (1:1) metal ion: I7C complex (MX, MX⁎). MX, MX⁎ are found to display excellent sensing capability for Zn2+ and Pb2+ ions. “Turn-On” response for Zn2+ is observed through the appearance of a new enhanced fluorescence at ~430 nm. By strong blue emission I7C establishes its strong candidature as “blue emitter”. “Turn-Off” response is observed for Pb2+ through the quenching of the existing fluorescence peak. - Highlights: • Indole-7-carboxaldehyde (I7C) shows “Turn-on” and “Turn-off” sensing for Zn2+ and Pb2+ ions. • I7C forms complex with metal ions (MX⁎). • 27-Fold strong blue fluorescence due to MZn⁎ formation indicates I7C as a good candidature to be used as blue emitter. • Computed (UV–vis absorption/emission, FTIR, NMR) data validate the experimental facts

  18. Highly selective probe based on imine linkage for Zn{sup 2+} and HSO{sub 3}{sup −} in mixed aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Kamaljot; Chaudhary, Savita; Singh, Sukhjinder; Mehta, S.K., E-mail: skmehta@pu.ac.in

    2015-04-15

    A simple salicylaldehyde derived Schiff base N, N′- bis (p-chloro salicylidene)-1, 2- ethylenediamine (L) was synthesized and characterized. The receptor demonstrates simultaneous dual channel chromogenic and fluorogenic signaling towards HSO{sub 3}{sup −} and Zn{sup 2+} in mixed aqueous media. Solvatochromism was employed systematically for modulating its optoelectronic properties. The probe was successfully assessed to monitor HSO{sub 3}{sup −} detection via UV–vis spectroscopy. DFT calculations and {sup 1}H NMR spectroscopy further support the results based on shifting of equilibrium. Moreover, the sensor showed large fluorescence enhancement with blue-shift of 48 nm after addition of Zn{sup 2+}. The probe exhibits high selectivity over other competitive ions with high detection limit of 6.54×10{sup −5} M and 3.21×10{sup −6} M for HSO{sub 3}{sup −} and Zn{sup 2+}, respectively. Importantly, this is one of the rare reports in which Schiff base was utilized for the fabrication of chromogenic or fluorogenic sensor using solvent effect for multianalyte detection. - Highlights: • Easy synthesis of highly selective and sensitive Salicylideneaniline moiety. • Solvatochromism induced tautomerism between the enol-imine and keto-amine forms. • Computational studies revealing the effect of solvent on stability of NH form. • Discriminative detection of HSO{sub 3}{sup −} and Zn{sup 2+} by different spectroscopic techniques. • Optical feedbacks as absorption transitions with HSO{sub 3}{sup −} on bisulphite adduct formation. • Fluorescence enhancement for Zn{sup 2+} based on imine binding mechanism.

  19. HAUPT, Barbara, BUSSE, Wilhelm G., Pilgerreisen in Mittelalter und Renaissance

    OpenAIRE

    Péricard-Méa, Denise

    2013-01-01

    Sous le titre Pèlerins au Moyen Age et à la Renaissance, les éditions Droste ont publié en 2006, dans la collection Studia Humanoria, un recueil de conférences prononcées à l’Institut de recherche sur le Moyen Âge et la Renaissance de l’université Heinrich-Heine à Düsseldorf pendant l’hiver 1997-98. Cette publication a été faite à la mémoire du professeur Anne-Marie Schimmel (décédée en janvier 2003). D’Anne-Marie Schimmel elle-même, cet ouvrage publie l’article « Pèlerinage – un voyage au ce...

  20. Reconstruction of skull defects in the middle ages and renaissance.

    Science.gov (United States)

    Missori, Paolo; Currà, Antonio; Paris, Harry S; Peschillo, Simone; Fattapposta, Francesco; Paolini, Sergio; Domenicucci, Maurizio

    2015-06-01

    In Egyptian, Greco-Roman, and Arabic medicine, the closure of a skull defect was not provided at the end of a therapeutic trepanation or in cases of bone removal. The literature from the Middle Ages and Renaissance disclosed some striking and forgotten practices. Gilbertus Anglicus (c. 1180 to c. 1250) cites the use of a piece of a cup made from wooden bowl (ciphum or mazer) or a gold sheet to cover the gap and protect the brain in these patients; this citation probably reflected a widely known folk practice. Pietro d'Argellata introduced the use of a fixed piece of dried gourd for brain protection to reconstruct a skull defect. In the late Renaissance, the negative folklore describing this outlandish practice likely led to the use of silver and lead sheets. Nevertheless, for centuries, large numbers of surgeons preferred to leave the dura mater uncovered after bone removal, and failed to apply any brain protection. PMID:25403799

  1. NEO-RENAISSANCE AND REVITALIZATION OF VOTIC – WHO CARES?

    Directory of Open Access Journals (Sweden)

    Margit Kuusk

    2011-01-01

    Full Text Available The paper deals with the reason for the decline of the Votic language and neo-renaissance and revitalization of the Votic.The reason for the decline of the Votic language are the small number of people, traditionally sparse population and the assimilation – the speakers of Votic have always lived in the sphere of influence of the Russian language and culture. The reasons for neo-renaissance are the collapse of the Soviet Union, a general trend to look for one’s roots, enthusiastic votophiles and the local activities. In the earlier times Votic national movement originated from local people, but recently there has been interest in the Votic affairs on the state level.The plans for the near future are under common title the Votic project.

  2. Alternative (Potentially Green) Separations Media: Aqueous Biphasic and Related Systems Extending the Frontier Final Report For Period September 1, 2002 January 31, 2007

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Robin D

    2007-06-25

    Through the current DoE-BES funding, we have extended our fundamental understanding of the critical phase separation of aqueous polymer solutions at the molecular level, and have developed a similar understanding of their application as novel solvent systems. Our principal aims included mode of delivery of the aqueous biphasic system (ABS) solvent system and the application of this system to problems of reactive extraction. In the former case we have developed novel solid phase analogues, in the form of cross-linked polyethylene glycol hydrogels, and in the latter case we have examined the role that ABS might play in reaction engineering, with a view to greener, simpler, and safer processes. We have also developed a new salt/salt ABS and have extended our understanding of this system as well. The major outcomes are as follows: (1) Through the use of variable temperature phase diagrams, coupled with differential scanning calorimetry (DSC) measurements of the phases, a better understanding of the thermodynamics of phase formation was obtained. Evidence to the existence and role of an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) (or both) in these systems was gained. With variable temperature solute partitioning, thermodynamic parameters were calculated, and inter-system comparisons were made. Through the use of Abraham's linear solvation energy regression (LSER) the solvent-solute properties of liquid/liquid ABS were examined. We have shown that ABS are indeed very tunable and LSERs have been used as a tool to compare these systems to traditional organic/water and other liquid/liquid systems. (2) We have successfully shown the development of novel reaction media for chemical synthesis and reaction; Aqueous Biphasic Reactive Extraction (ABRE). As a proof of concept, we have shown the synthesis of adipic acid from cyclohexene in an ABS, which represents an important development in the exploitation of this technology

  3. Compositio and the Materiality of Architecture in the Italian Renaissance

    OpenAIRE

    Payne, Alina

    2009-01-01

    The sources which Renaissance architects used to develop their architectural compositions were not strictly architectural but were drawn from a wider visual field, and often involved heterogeneous material. This was so because the ancient models, imperfectly preserved as amputated fragments and often only apprehensible through a great effort of the imagination, needed to be fleshed out by other means: by architectural representations on ancient coins, plaquettes, sculptural reliefs, cameos et...

  4. Manufacturing Renaissance : Return of manufacturing to western countries

    OpenAIRE

    Kianian, Babak; Larsson, Tobias; Tavassoli, Mohammad

    2013-01-01

    This paper argues that the location of manufacturing is gradually shifting to the west again, i.e. Manufacturing Renaissance. Such claim is based on the recent observed trend and the discussion is contextualized within the established theory that has been able to explain the location of manufacturing, i.e. Product Life Cycle Model (PLC). Then the paper identifies and discusses the four main drivers of this new phenomenon. Finally, it is noted that the rerun of manufacturing should be kept in ...

  5. Core value deployment: the need for a new renaissance

    DEFF Research Database (Denmark)

    Dahlgaard, Jens Jørn; Dahlgaard, Su Mi Park

    1998-01-01

    In a recent articel (Su Mi Park Dahlgaard et al: "Core values - the pre-condition for business excellence") defined a Profound Leadership System as consisting of two subsystems: 1. The core value subsystem and 2. The competence subsystem. It was concluded that the core value subsystem is the most...... answer to this question is found when comparing the difference in focus from the Middle Ages to the Renaissance and until today. Udgivelsesdato: JUL...

  6. The Ionian Renaissance and the Hellenistic Architecture of Kos

    DEFF Research Database (Denmark)

    Pedersen, Poul

    2015-01-01

    I artiklen påvises det, at både det gamle og det nye tempel i helligdommen for lægeguden Asklepios på den græske ø Kos har tekniske særegenheder (det karisk-ioniske løftehul), som viser at de to templer blev bygget af håndværkere fra det vestlige Lilleasien, som arbejdede i den ioniske renaissances...

  7. RAILROAD RENAISSANCE: THE POST-1970 SHORT LINE MOVEMENT

    Directory of Open Access Journals (Sweden)

    Michael Landry

    2001-01-01

    Full Text Available Since 1970 and especially since railroad deregulation in 1980, there has been a proliferation of hundreds of new short line rail companies. These railroads range in length from about a mile to more than a thousand miles (those over 350 miles are called “regionals”. They were mainly formed when major Class 1 rail systems spun off marginal trackage. This paperdiscusses the reasons for the short line renaissance.

  8. Cultural Critique and Cultural Orthodoxy in Two Renaissance Plays

    OpenAIRE

    Akram Shalghin

    2014-01-01

    At a time of historically monumental events in England, most notably the transition from feudalism to capitalism and establishing colonies abroad, there had been cultural oscillation between the old mode of life and the new understanding of life. Renaissance literary texts showed signs of criticism of the old tenets but could not register a substantial break up with them. Literary texts were engaged also in the act of colonisation taking place remotely from the English shores, their engagemen...

  9. Truth and Fibble-Fable in Renaissance Satire

    Directory of Open Access Journals (Sweden)

    Branko Madžarevič

    2011-12-01

    Full Text Available Throughout the years of my close involvement with wor(lds’ transactions, as a translator, in the triangle of the Renaissance doctors Rabelais, Montaigne, and, yes, Louis-Ferdinand Céline, the French author of the novel Journey to the End of Night (1932, their views on satire can be considered from a rather unconventional angle. By means of an imaginary morbid epistolary medical council, the impromptu introduction tries to entangle this peculiar trio in a freewheeling alliance, leading to the assumption that every translation defies the interpretational ambiguities of the utopian Thelema motto “Do as you will”. In the satirical context of all source and target faces, it is always acting on the verge of the paradoxical encomium, the hypothetical pasticcio, and obscurantist reversals of the original text. Of course, the issue at stake here is one of the convolutions of Erasmus’ Praise of Folly, Rabelais’ utopian Thelema Abbey, and the German Epistles of Obscure Men in pathetically wretched Latin. This paper deals with Renaissance and humanist satire, focusing on Rabelais’ five books of Gargantua and Pantagruel (1532–1564 and the interplay between the ideas of truth, truthfulness, and seriousness. In addition, the paper deals with how the Renaissance spirit of this satirical contemporary and ally of ours challenges the issue of verbal boundaries and the materiality of language.

  10. Media for Reflection

    DEFF Research Database (Denmark)

    Knudsen, Morten

    2016-01-01

    This article develops the concept media for reflection in the interest of conceptualizing the interpretative frames that enable and limit reflection in management and leadership education. The concept ‘media for reflection’ allows us to conceptualize the social and cultural mediation of reflection...... without reducing reflection to an effect of the social structures and cultural norms in which it is embedded. Based on the developed theoretical framework, this article analyses how a renaissance ‘mirror for princes’ and contemporary research-based management education mediate reflection. The content of...... the mediations is analysed as well as the societal and organizational background. Furthermore, the means by which the two media enable and limit reflection in different ways is compared. Finally, the article discusses possible implications of the analysis in terms of management and leadership...

  11. Phase behavior, diffusion, structural characteristics, and pH of aqueous hydrophobic ionic liquid confined media: insights into microviscosity and microporsity in the [C4C4im][NTf2] + water system.

    Science.gov (United States)

    Nanda, Raju; Kumar, Anil

    2015-01-29

    We present our studies on the physicochemical properties of water confined in Dibutylimidazolium bis(trifluoromethanesulfonylimide) ([C4C4im][NTf2]) reverse micelles through the NMR relaxation measurements that provide us an understanding of microviscosity and pH in the confined condition. We present experimental results on phase behavior, diffusion, structural characteristics and pH in aqueous ionic liquid-confined media. The ternary phase diagram was constructed by the cloud point measurements and the microheterogeneous regions were detected by the measurement of bulk viscosity and diffusion coefficients of K4[Fe(CN)6] inside the homogeneous microemulsion systems through the cyclic voltammetric (CV) measurements. The size of the microemulsion systems was characterized by the dynamic light scattering (DLS) method. The (1)H NMR spectra of homogeneous microemulsion systems were taken which indicates the presence of bound and free water molecules inside the microemulsion system. The NMR spin-lattice relaxation time (T1) of water molecules in its homogeneous microemulsion systems were measured and the reorientational correlation time (τc) of water molecules obtained from it indicates that the fluidity of homogeneous confined media decreases with the decrease in the composition of water. Microviscosity of the aqueous confined media was calculated from the measured T1 relaxation time values by applying the Debye-Stokes equation and correlated with the bulk viscosity of the samples. It was observed that both the microviscosity and bulk viscosity show inverse relationship. The fraction of bound and free water molecules were calculated from the measured T1 values. NMR spin-spin relaxation time (T2) of water molecules in its homogeneous microemulsion systems were measured with the varying pH of the aqueous core. A change in the T2 relaxation time of the water proton was observed proposing an exchange of proton between the H2O and -OH group of the TX-100 molecules. Finally

  12. 'PET' vs. 'push-pull' induced ICT: a remarkable coumarinyl-appended pyrimidine based naked eye colorimetric and fluorimetric sensor for the detection of Hg2+ ions in aqueous media with test trips.

    Science.gov (United States)

    Goswami, Shyamaprosad; Das, Avijit Kumar; Maity, Sibaprasad

    2013-12-14

    A novel colorimetric and fluorescent chemosensor based on 7-(diethylamino)-3-(pyrimidin-4-yl)-2H-chromen-2-one (PYC) has been designed and synthesized for the detection of Hg(2+) in the presence of other competing metals in mixed aqueous media. The PYC exhibits naked eye color change from green to red, and the fluorescence color changes from yellowish green to light orange with Hg(2+). It also shows a red shift in wavelength of about 80 nm in absorption spectra. Test strips based on PYC were fabricated, which could act as convenient and efficient Hg(2+) test kits. PMID:24096453

  13. Magnetically recoverable catalysts based on mono- or bis-(NHC) complexes of palladium for the Suzuki-Miyaura reaction in aqueous media: two NHC-Pd linkages are better than one.

    Science.gov (United States)

    Martínez-Olid, Francisco; Andrés, Román; de Jesús, Ernesto; Flores, Juan C; Gómez-Sal, Pilar; Heuzé, Karine; Vellutini, Luc

    2016-08-01

    Pre-synthesized mono- and bis(NHC) palladium complexes have been grafted onto magnetic core/shell γ-Fe2O3/silica particles and tested as catalysts in model Suzuki-Miyaura coupling reactions. The bis(NHC) immobilized complex was found to be a robust catalyst that can operate under mild conditions in aqueous media, even for the activation of chloroarene, whereas the mono(NHC) counterpart rapidly deactivates. Moreover, it can be readily recovered by magnetic separation and reused many times, providing very high productivities, and with so low leaching of palladium that the crude products obtained contain ≤10 ppm Pd. PMID:27365169

  14. Ultrasound promoted one-pot synthesis of 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile scaffolds in aqueous media: a complementary 'green chemistry' tool to organic synthesis.

    Science.gov (United States)

    Banitaba, Sayed Hossein; Safari, Javad; Khalili, Shiva Dehghan

    2013-01-01

    A green and simple approach to assembling of 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile scaffolds via three-component reaction of kojic acid, malononitrile, and aromatic aldehydes in aqueous media under ultrasound irradiation is described. The combinatorial synthesis was achieved for this methodology with applying ultrasound irradiation while making use of water as green solvent. In comparison to conventional methods, experimental simplicity, good functional group tolerance, excellent yields, short routine, and selectivity without the need for a transition metal or base catalyst are prominent features of this green procedure. PMID:22939001

  15. A highly selective colorimetric and "turn-on" fluorimetric chemosensor for detecting CN(-) based on unsymmetrical azine derivatives in aqueous media.

    Science.gov (United States)

    Sun, You; Hu, Jing-Han; Qi, Jing; Li, Jian-Bin

    2016-10-01

    A novel highly selective chemosensor S1 for cyanide based on unsymmetrical azine derivative was successfully designed and synthesized, which showed both colorimetric and fluorescence turn-on responses for cyanide ions in aqueous. This structurally simple chemosensor could detect CN(-) anion over other anions in aqueous solution DMSO/H2O (v/v=3:2) undergo deprotonation reaction. Results showed that the chemosensor S1 exhibited 50 fold enhancement in fluorescence at 530nm and showed an obvious change in color from colorless to yellow that could be detected by naked eye under the UV-lamp after the addition of CN(-) in aqueous solution. Moreover, the detection limit on fluorescence response of the sensor to CN(-) is down to 6.17×10(-8)M by titration method. Test strips based on S1 were obtain, which could be used as a convenient and efficient CN(-) test kit to detect CN(-) in aqueous solution. PMID:27261890

  16. The political uses of astrology: predicting the illness and death of princes, kings and popes in the Italian Renaissance.

    Science.gov (United States)

    Azzolini, Monica

    2010-06-01

    This paper examines the production and circulation of astrological prognostications regarding the illness and death of kings, princes, and popes in the Italian Renaissance (ca. 1470-1630). The distribution and consumption of this type of astrological information was often closely linked to the specific political situation in which they were produced. Depending on the astrological techniques used (prorogations, interrogations, or annual revolutions), and the media in which they appeared (private letters or printed prognostica) these prognostications fulfilled different functions in the information economy of Renaissance Italy. Some were used to legitimise the rule of a political leader, others to do just the opposite. Astrological prorogations and interrogations were often used to plan military and political strategies in case of the illness or death of a political leader, while astrological prognostications were generally written to promote certain political leaders while undermining others. While certainly often partisan to this game, astrologers, for their part, worked within a very well established tradition that gave authority to their forecasts. This paper argues that, as indicators of deeper political tensions otherwise not always explicitly manifest, these prognostications are privileged sources of information providing a better understanding of the political history of the period. PMID:20513625

  17. A Postmodern Thanatic Triad: Crisis, Pornography and Renaissance of Death

    Directory of Open Access Journals (Sweden)

    Ilona Zakowicz

    2011-06-01

    Full Text Available In every age we can find a different attitude of man towards the end of life, instanced in varied stances and imaginations regarding death. In postmodernism, which makes a broader context for this work, it is impossible to present one unified image of death, because the attitude of contemporary men towards death and the visual forms of it are greatly varied. The subject of my analysis is a presentation of death shown in three occurrences the crisis, the pornography and the renaissance of death which combine to form the postmodern thanatic triad.

  18. Africa's Quest for Developmental States: 'renaissance' for whom?

    DEFF Research Database (Denmark)

    Shaw, Timothy Milton

    2012-01-01

    After a generally disappointing half-century since recapturing formal independence, at the turn of the second decade of the 21st century, Africa(s) may now be able to seize unanticipated emerging opportunities to move from `fragile' or `failed' towards `developmental' political economies. The...... continent displays innovations in terms of sources of finance, new regionalisms & transnational governance leading to distinctive insights for analysis & policy, both state & non-state. Its potential for renaissance is reinforced by South Africa's accession as the fifth of the BRICS at the dawn of the...

  19. Cultural Critique and Cultural Orthodoxy in Two Renaissance Plays

    Directory of Open Access Journals (Sweden)

    Akram Shalghin

    2014-10-01

    Full Text Available At a time of historically monumental events in England, most notably the transition from feudalism to capitalism and establishing colonies abroad, there had been cultural oscillation between the old mode of life and the new understanding of life. Renaissance literary texts showed signs of criticism of the old tenets but could not register a substantial break up with them. Literary texts were engaged also in the act of colonisation taking place remotely from the English shores, their engagement was subversive at times but contained at others. 

  20. Low-power critical facilities: their role in the nuclear renaissance

    International Nuclear Information System (INIS)

    This paper discusses the role of low power critical facilities and their role in the nuclear renaissance. It outline the role of human capital in some detail. sufficient conditions for the renaissance are that nuclear power is safe, sustainable, economical and proliferation resistant.

  1. Readings of Platonic Virtue Theories from the Middle Ages to the Renaissance

    DEFF Research Database (Denmark)

    Catana, Leo

    2014-01-01

    It is commonly known that ancient schools of ethics were revived during the Renaissance: The texts pertaining to Platonic, Aristotelian, Stoic and Epicurean ethics were edited, translated and discussed in this period. It is less known that the Renaissance also witnessed a revival of Plotinian...

  2. “PASANTIAN”IN BALI AND ITS RENAISSANCE IN GLOBALIZATION ERA

    Directory of Open Access Journals (Sweden)

    I Komang Sudirga

    2013-02-01

    Full Text Available Pasantian, which means reading and reciting a literary work, is growing, developing and resurrecting resistively in the life of the Balinese community in the globalization era. This study tries to answer the following questions: (1 what was the renaissance of pasantian in the globalization era in Bali like; (2 what factors contributed to the renaissance of pasantian in the globalization era in Bali; (3 what was the meaning of the renaissance of pasantian in the globalization era in Bali? This study in which qualitative method was used. It was intended to identify the existence of pasantian and its dynamism through its renaissance in the globalization era. The theory of deconstruction (Derrida, in Norris, 2008, the theory of practice (Bourdieu in Takwin, 2009 and Fashri, 2007, the theory of postmodern (Piliang, 2004, and Piliang, 2004a, and the theory of hegemony (Gramsci, in Barker, 2005 were eclectically used to analyze the data. The result showed that the renaissance of pasantian took place in three periods; the initial renaissance took place from 1979 to 1990, the second from 1991 to 1998, and the third from 1999 to 2010s. Such a renaissance was supported by cultural factors. In addition, political and economic factors also contributed to the renaissance of pasantian. It had socio-cultural, and economic effects, which led to multi-meanings such as educational meaning, entertainment meaning, the meaning of politics of image, the meaning of hypermorality, and the meaning of maintenance of socio-cultural meanings.

  3. The Renaissance Culture and the Arts. Grades 3-6, The Time Traveler Series.

    Science.gov (United States)

    Pofahl, Jane

    This resource guide encourages grade 3-6 students to explore the social structure, government, culture and art forms, scientific discoveries, and historic personalities of the European Renaissance. The work is organized into 10 topics: (1) The Renaissance; (2) Art; (3) Leonardo da Vinci; (4) The Medicis; (5) Michelangelo; (6) Printing; (7) Music;…

  4. Philadelphia's Renaissance Schools: A Report on Start up and Early Implementation

    Science.gov (United States)

    Gold, Eva; Good, Deborah; Robertson-Kraft, Claire; Callahan, M. Kate

    2011-01-01

    In April 2009, Superintendent Arlene Ackerman announced her reform plan for the School District of Philadelphia (the District)--"Imagine 2014". Among other major initiatives, "Imagine 2014" laid the groundwork for Philadelphia's Renaissance Schools Initiative. The Renaissance Initiative, set to enter its second year in 2011-12, is an effort to…

  5. A Nuclear Energy Renaissance in the U.S.?

    International Nuclear Information System (INIS)

    Is it time for a nuclear energy renaissance? Among other things, nuclear power is a carbon neutral source of base load power. With the growth in energy use expected over the next 20 years and the growing negative impacts of global climate changes, the cost of oil and gas, energy security and diversity concerns, and progress on advanced reactor designs, it may be the right time for nuclear power to enter a new age of growth. Asia and Russia are both planning for a nuclear renaissance. In Europe, Finland and France have both taken steps to pursue new nuclear reactors. U.S. utilities are preparing for orders of new reactors; one submitted a request to the U.S. Nuclear Regulatory Commission (NRC) to review its request to construct a new reactor on an existing site. What has the industry been doing since nuclear energy was birthed in the 1960s? In those days a bold new industry boasted that nuclear power in the United States was going to be ''too cheap to meter'', but as we all know this did not come about for many reasons. Eventually, it became clear that industry had neglected to do its homework. Critiques of the industry were made on safety, security, environment, economic competitiveness (without government support), and nonproliferation. All of these factors need to be effectively addressed to promote the confidence and support of the public - without which a nuclear power program is not feasible.

  6. Sappho's shifting fortunes from antiquity to the early Renaissance.

    Science.gov (United States)

    Penrose, Walter

    2014-01-01

    Although Sappho was revered as the greatest woman poet of all time by the Greeks, in later antiquity and the Middle Ages, her love of women was considered shameful and overshadowed her excellent reputation. She was also called a prostitute, and fictional accounts of her affairs with men further "tarnished" her reputation. Dual representations of Sappho existed within two centuries of her death. On the one hand, she was a role model for other poets to follow in their quest for fame, on the other she was the quintessential representation of female vice, which, at least by the Roman period, brought her infamy. Late antique and medieval Christian authors inherited this latter view, and vilified Sappho's sexuality, while church authorities, at least according to legend, had her works publicly burned. In the initial stages of the Renaissance, then, the humanist desire to reconnect with the pagan past had to proceed in the context of late medieval Christianity. Sappho's homoeroticism was erased, ultimately, in order that her skill could be lauded to fight misogyny. Hence, the humanists "rehabilitated" Sappho's virtue in a Christian context where same-sex love was considered an "unmentionable" vice. In order to argue that women were smart and capable, the humanists needed Sappho. She was perhaps the most famous, and most skilled, woman who had ever lived, and her example was used in an attempt to improve the lot of women in the early Renaissance. PMID:25298101

  7. The renaissance of nuclear power. Causes and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Hillriches, Christian [AREVA NP GmbH, Erlangen (Germany)

    2008-07-01

    An increase in the use of nuclear energy for power generation is predicted worldwide. Confirmation of this trend can already be found today in extensions to nuclear power plant operating licenses and projects for nuclear plant upgrading and uprating. Numerous countries have decided to build new nuclear power plants or are planning to do so, even countries that have not used nuclear energy in the past. The reasons for this global renaissance include a growing demand for electric power all over the world, awareness that our fossil resources are limited, the desire by many countries to reduce their dependence on energy imports, and the drive to combat climate change. The nuclear industry is rising to this challenge by offering advanced reactors of the 3rd generation, by consolidating and restructuring manufacturing capacities, by building up staffing levels and investing in production facilities and the fuel cycle. Standardizing technology, progressively harmonizing safety requirements across national borders and setting up long-term cooperation agreements between vendors and plant operators are options that can help turn the global renaissance of nuclear power into a sustainable success. (orig.)

  8. The logic of physiognomony in the late Renaissance.

    Science.gov (United States)

    Maclean, Ian

    2011-01-01

    This article studies the advances made in the logic of Renaissance physiognomy from the state of the subject in antiquity and the Middle Ages. The properties and accidents of the human body are investigated in the context of the signs selected by physiognomers, whether univocal or in syndromes, strong or weak in character, negative or positive, consistent with each other or contradictory. When these signs are translated into propositions, the construction of argument which flows from them is shown to be ut plurimum reasoning, in which an element of quasi-mathematical proto-probability and hermeneutical thinking (in the treatment of ambiguity and obscurity) may be detected. These allow the question "is x more likely to be the case than y or z?" to be answered through a variety of procedures. Renaissance physiognomy is shown to be a discipline in which a novel combination of rational procedures come together, and a site of conceptual change in respect of property and accidence. PMID:22073751

  9. The renaissance of nuclear power. Causes and challenges

    International Nuclear Information System (INIS)

    An increase in the use of nuclear energy for power generation is predicted worldwide. Confirmation of this trend can already be found today in extensions to nuclear power plant operating licenses and projects for nuclear plant upgrading and uprating. Numerous countries have decided to build new nuclear power plants or are planning to do so, even countries that have not used nuclear energy in the past. The reasons for this global renaissance include a growing demand for electric power all over the world, awareness that our fossil resources are limited, the desire by many countries to reduce their dependence on energy imports, and the drive to combat climate change. The nuclear industry is rising to this challenge by offering advanced reactors of the 3rd generation, by consolidating and restructuring manufacturing capacities, by building up staffing levels and investing in production facilities and the fuel cycle. Standardizing technology, progressively harmonizing safety requirements across national borders and setting up long-term cooperation agreements between vendors and plant operators are options that can help turn the global renaissance of nuclear power into a sustainable success. (orig.)

  10. Extraction of scandium from various media with triisoamyl phosphate. Communication 1. extraction of Sc and impurity metals from aqueous nitric acid solutions

    International Nuclear Information System (INIS)

    The main features of extraction of Sc from aqueous nitric acid solutions with triisoamyl phosphate (TIAP) were studied. It was shown that Sc passes into the organic phase in the form of Sc(NO3)3·3TIAP. The extraction isotherms of Sc from its aqueous HNO3 solutions and from those containing salting-out agents (LiNO3, NH4NO3) with TIAP in dodecane were obtained. The distribution factor of Sc was studied in relation to the concentrations of TIAP, salting-out agent, and HNO3. The extraction of Sc and impurity metals (Zr, Th, REE) with TIAP was studied using a tracer technique at widely varied HNO3 concentration in the aqueous phase. The separation factors of Sc from impurity metals were determined

  11. A Declining Region: Provincial Renaissance Revisited (Case of Volgograd Region

    Directory of Open Access Journals (Sweden)

    Drozdova Yuliya

    2014-12-01

    Full Text Available The paper analyzes findings yielded by the empirical study performed in the framework of an RGNF grant entitled “Image of a region as a communicative strategy for the authorities and mass media”. The methods of study included expert survey and formal survey (N=1000, July-September 2013, studying the opinion of respondents who were either internal experts residing in the Volgograd region (N=20; May-September 2013 or external experts who reside outside the region but maintain stable ties with the representatives of state and municipal authorities, regional mass media and business. The findings indicate that the Volgograd region has fallen behind other modernized Russian regions, that young people tend to leave it, that a negative image of the region as a declining territory persists. Answers to the open question “What is unacceptable for you in the existing image of the Volgograd region?” revealed major problems determining the local context of a declining region, and those were issues associated with inefficient regional/municipal administration: “the condition of the roads”, “constant replacement of people in the administration”, “politics as a whole”, “a destitute region without a good manager”, “unemployment”, “countryside is dying off”, “indifference of the authorities”, “roads, housing and public utilities and the administration”, “the authorities are not responsible for the people”, “the authorities do not solve the problems of the city or its people”, “thieving”, “dishonest authorities”, “the region goes to rack and ruin, no kindergartens or jobs”, “one cannot even walk in the streets”, “corruption”, “a stagnant region with low pay”, “no perspectives in the future”, “the region is stagnating due to corruption among officials”. According to the local Census Bureau, the Volgograd region can be classified as a declining territory where the population decline

  12. Analysis of comparison between the theoretical and experimental solubilities of the ThO2 and CeO2 in different aqueous media

    International Nuclear Information System (INIS)

    The present work shows the effect of the complexity of the surrounding aqueous medium that will surround the nuclear fuel stored in the solubility of the and Ce. In the case of Th, this influence is clearly accused, and the difference between the experimental and the theoretical solubility of parent company pure phase, is due to the formation of actinide-hidroxo-carbonate complex.

  13. THE SYNTHESIS OF IMIDAZOLES VIA THE RADZISZEWSKI REACTION IN AQUEOUS MEDIA DIE Synthese von Imidazolen ÜBER DAS Radziszewski Reaktion in wässrigen Medien

    Directory of Open Access Journals (Sweden)

    July A.Hernández Muñoz,Bruno Dias de C. F. dos Santos,Renata F. Soares,Erika M. de Carvalho,Joel Jones Junior and Flavia M. da Silva

    2011-10-01

    Full Text Available A new, simple and eco-friendly protocol has been developed for the preparation of trisubstituted imidazoles through the Radziszewski reaction between formaldehyde (37% aqueous solution, amines, ammonium carbonate and biacetyl. The synthesis was conductedat room temperature using water as the solvent.

  14. La Renaissance d’Alberto Tenenti (1924-2002)

    OpenAIRE

    Ossola, Carlo

    2014-01-01

    Pour le dixième anniversaire de la mort d’Alberto Tenenti, le Collège de France – où enseignèrent deux de ses maîtres, Lucien Febvre et Fernand Braudel –, l’École des hautes études en sciences sociales, où il accomplit l’essentiel de sa carrière, et Florida State University, où enseigne aujourd’hui un de ses anciens élèves, ont rendu hommage à un des plus importants historiens de l’économie, de la culture et de l’État à la Renaissance. Copyright : Patrick Imbert, Collège de France Le colloqu...

  15. Nuclear power 2009. Renaissance of an energy source?

    International Nuclear Information System (INIS)

    In spite of some setbacks, the peaceful use of nuclear energy has been quite successful in its fifty years of history. In 2008, there were 438 nuclear reactors world-wide, which generated about 13 % of the total power generated that year; 2.5 thousand million tonnes of CO2 emissions were prevented, and fossil resources in the range of about 1.35 thousand million tonnes t.c.e were saved. In the overall power mix, nuclear power has ensured price stability as it is still one of the least costly energy sources. (In the USA, nuclear power is indeed the least costly energy source, with a price of 1.87 US cents per kWH, followed by coal at 2.75 US cent per kWH). There is also a current trend towards reviewing the option of new power plants, which may indeed herald a renaissance. (orig.)

  16. 未来的Renaissance Schaumburg电缆

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    伊利诺斯州新近开业的Renaissance Schaum—burg酒店和会议中心是用想象中的未来技术建造的。“我们准备了现在还只是梦想的事物,”复兴酒店和度假村多产业系统经理Eric Ventura说道。“当IP上的声音和IP上的图像技术投入消费者市场时.基础设施就已在我们的建筑中存在,以满足这些技术需求.”

  17. SNE-TP strategic research agenda - The nuclear renaissance

    International Nuclear Information System (INIS)

    INR Pitesti has become on September 21, 2007 a partner in the Sustainable Nuclear Energy Technology Platform (SNE-TP), an European Technology Platform aimed at promoting the research, development and demonstration (RD and D) of European nuclear fission technologies (http://www.snetp.eu). To achieve this objective, the SNE-TP has worked out its Strategic Research Agenda (SRA) which identifies and prioritises the research topics. Over 150 scientists, researchers and engineers have contributed to the drafting of the SRA. They come from the 60 or more member organizations of the SNE-TP, including INR Pitesti, representing industry, research organizations, technical safety organizations and academia. The SRA is a living document open for revision every 3 to 4 years. The Generation III Reactors as 'The Nuclear Renaissance' will be presented in the paper. (authors)

  18. Sampling theory, a renaissance compressive sensing and other developments

    CERN Document Server

    2015-01-01

    Reconstructing or approximating objects from seemingly incomplete information is a frequent challenge in mathematics, science, and engineering. A multitude of tools designed to recover hidden information are based on Shannon’s classical sampling theorem, a central pillar of Sampling Theory. The growing need to efficiently obtain precise and tailored digital representations of complex objects and phenomena requires the maturation of available tools in Sampling Theory as well as the development of complementary, novel mathematical theories. Today, research themes such as Compressed Sensing and Frame Theory re-energize the broad area of Sampling Theory. This volume illustrates the renaissance that the area of Sampling Theory is currently experiencing. It touches upon trendsetting areas such as Compressed Sensing, Finite Frames, Parametric Partial Differential Equations, Quantization, Finite Rate of Innovation, System Theory, as well as sampling in Geometry and Algebraic Topology.

  19. History of allergy in the middle ages and renaissance.

    Science.gov (United States)

    Ring, Johannes

    2014-01-01

    In the Middle Ages little innovative medical literature came from Western Europe. The Greek-Roman tradition with the scriptures of Hippocrates and Galenos was preserved in Byzantium and then in the Middle East by Arabic medicine; it then returned to Europe in Latin translations mostly made in Italy and Spain. There were innovative developments in Arabic medicine also with regard to the history of allergy, especially with the first description of 'rose fever', which is described as very similar in symptomatology to hay fever. Under Arabic influence, the first medical university in Salerno was famous for its well-known text Tacuinum sanitatis in which a description of asthma can be found. With the beginning of renaissance new developments were also registered in Europe, with new observations and a new way of thinking. PMID:24925380

  20. MS PHD'S Professional Development Program: A Scientific Renaissance in Cyberspace

    Science.gov (United States)

    Powell, J. M.; Williamson, V. A.; Griess, C. A.; Pyrtle, A. J.

    2004-12-01

    This study is a component of a four-year investigation of MS PHD'S Professional Development Program's virtual community through the lenses of underrepresented minority students in Earth system science and engineering fields. In this presentation, the development, assessment and projected utilization of the ongoing study will be discussed. The overall goal of this study is to examine the effectiveness of virtual team building methods and understand how the development of a communal cyberinfrastructure acts as an integral part of the emergence of a Scientific Renaissance. The exemplar, Minorities Striving and Pursuing Higher Degrees of Success in Earth System Science (MS PHD'S), provides professional development experiences to facilitate the advancement of students of color achieving outstanding Earth system careers. Undergraduate and graduate students are supported through access to scientific conferences, mentorship and virtual community building. Framed by critical theory, this ethnographic exploration uses a mixed methods research design to record, observe, and analyze both the processes and products of the website, listserv and synchronous web-based dialogue. First, key findings of the formative evaluation and annual reports of the successfully implemented 2003 MS PHD'S Pilot Project are presented. These findings inform future evaluations of the use of technological resources and illustrate how this public space provides peer support and enriched research opportunities. Quantitative methods such as statistical analysis, academic and professional tracking and evaluative tools for scientific content and competency are complimented by qualitative methods that include observations, heuristic case studies and focus group interviews. The findings of this ongoing investigation will provide insight on how national organizations, higher education practitioners, community-based support systems and underrepresented minorities in the sciences promote diversity by developing

  1. Chemical stability of ecomustine, a new antitumor agent in aqueous and biological media as assessed by high-performance liquid chromatography.

    Science.gov (United States)

    el Abed, I; Roger, P; Gosse, C; Atassi, G; Gouyette, A

    1991-01-01

    Ecomustine, or CY233 (NSC-609224), is a new water-soluble nitrosoureido sugar derived from acosamine. A high-performance liquid chromatographic assay (HPLC) developed to quantify the unchanged drug in aqueous solutions and biological specimens enabled us to study the chemical stability as a function of pH, light, and temperature. In buffered aqueous solutions, the kinetics of degradation of CY233 is a first-order process. The log k-pH profile demonstrated hydroxide ion-catalyzed solvolysis. The drug is most stable at pH 4, more stable than some other nitrosoureas in 5% glucose (t1/2, 62-67 h) and in 0.9% isotonic saline (t1/2, 25-37 h) solutions. Based on these findings, blood samples should be collected in cold tubes (4 degrees C) containing citrate buffer (pH 4) and all manipulations should be protected from heat and light. PMID:1998985

  2. C(sp2)–C(sp2) cross coupling reaction catalyzed by a palladacycle phosphine complex: A simple and sustainable protocol in aqueous media

    Indian Academy of Sciences (India)

    Seyyed Javad Sabounchei; Marjan Hosseinzadeh

    2015-11-01

    The Heck reactions of various aryl halides with olefins using {[Ph2PCH2PPh2CH=C(O)(C10H7)] PdCl2} as efficient catalyst has been investigated. The mononuclear palladacycle complex showed excellent activity in aqueous phase including the C(sp2)–C(sp2) cross coupling reactions. The advantages of the protocol are high yields, short reaction time, a cleaner reaction profile and notable simplicity.

  3. One-pot, three-component synthesis of a library of spirooxindole-pyrimidines catalyzed by magnetic nanoparticle supported dodecyl benzenesulfonic acid in aqueous media.

    Science.gov (United States)

    Deng, Jia; Mo, Li-Ping; Zhao, Fei-Yang; Zhang, Zhan-Hui; Liu, Shou-Xin

    2012-05-14

    Dodecyl benzenesulfonic acid functionalized silica-coated magnetic nanoparticles (γ-Fe2O3@SiO2-DDBSA) were readily prepared and identified as an efficient catalyst for the synthesis of a library of spirooxindole-pyrimidine derivatives by three-component condensation reaction of barbituric acids, isatins and cyclohexane-1,3-diones. The aqueous reaction medium, easy recovery of the catalyst using an external magnet, and high yields make the protocol sustainable and economic. PMID:22533528

  4. Diammonium hydrogen phosphate as a versatile and efficient catalyst for the one-pot synthesis of pyrano[2,3-d]pyrimidinone derivatives in aqueous media.

    Science.gov (United States)

    Balalaie, Saeed; Abdolmohammadi, Shahrzad; Bijanzadeh, Hamid Reza; Amani, Ali Mohammad

    2008-05-01

    Diammonium hydrogen phosphate, (NH4)2HPO4, was used as a catalyst for one-pot, three-component condensation reactions consisting of aromatic aldehydes, malononitrile and barbituric/thiobarbituric acid in aqueous ethanol at room temperature. This method has the advantages of a simple operation, mild reaction conditions, high yields, by using a less toxic and low cost chemical as a catalyst. PMID:18512127

  5. Uranium chemistry in blood and aqueous media. Techniques of studies; Chimie de l`uranium en milieux aqueux et sanguin. Techniques d`etudes

    Energy Technology Data Exchange (ETDEWEB)

    Scapolan, St.

    1996-11-01

    The object of this report in a first step, is to understand the chemistry of uranium in aqueous phase by specifying the behavior of this element in function of several parameters such PH, concentration of present species, temperature, ionic force. In a second step, investigation techniques are reviewed: X rays diffraction, potentiometric titrations, polarography, spectrophotometry, NMR of {sup 13}C, {sup 31}P, {sup 17}O, capillary electrophoresis, laser detection. The third part brings elements to understand the uranium complexation in blood medium.

  6. Forms of Government in the Renaissance: Uniqueness of the Dubrovnik Model

    OpenAIRE

    Grubiša, Damir

    2011-01-01

    The author looks into the forms of political government in the Renaissance, and the typology thereof as provided by Niccolo Machiavelli in The Prince and in Discourses on Livy. The article aims to examine whether there is a differentia specifica distinguishing the Dubrovnik form of political order from similar forms of political government in Renaissance times. Republican forms of political government are analysed here, and the author stresses the existence of forms situated...

  7. Myths of Male Same-Sex Love in the Art of the Italian Renaissance

    OpenAIRE

    Ann Haughton

    2015-01-01

    Visual culture has much to contribute to an understanding of the history of sexuality. Yet, to date, the depiction of pederasty in the art of the Renaissance has not been covered adequately by dominant theoretical paradigms. Moreover, the interpretive approach of traditional art historical discourse has been both limited and limiting in its timidity toward matters concerning the representation of sexual proclivity between males. This article will address the ways in which Italian Renaissance ...

  8. The Harlem Renaissance and the story behind the fiction of Carl Van Vechten

    OpenAIRE

    Lau, Suet-wing; 劉雪穎

    2014-01-01

    The Harlem Renaissance was the most celebrated African American cultural movement throughout the history of the United States owing to the massive and remarkable literature output by African American artists. Yet, attention to the white participants is limited. One of the most significant white patrons and writers, Carl Van Vechten and his fifth novel Nigger Heaven (1926) have cast noteworthy influences on African Americans, the American society and the Harlem Renaissance. To examine Van Vech...

  9. The synthesis of (N 2O 2S 2)-Schiff base ligands and investigation of their ion extraction capability from aqueous media

    Science.gov (United States)

    Zoubi, Wail A. L.; Kandil, Farouk; Chebani, Mohamad Khaled

    2011-09-01

    Two new Schiff bases (I) and (II) containing nitrogen-sulfur-oxygen donor atoms were designed and synthesized in a multi-step reaction sequence. The Schiff base (I) was used in solvent extraction of metal chlorides such as Cu 2+ and Cr 3+ as well as metal picrates such as Hg 2+ and UO 22+ from aqueous phase to the organic phase. The influences of the parameter functions, such as pH, solvent, ionic strength of aqueous phase, aqueous to organic phase and concentration of the extractant were investigated to shed light on their chemical extracting properties upon the extractability of metal ions. The effect of chloroform, dichloromethane and nitrobenzene as organic solvents over the metal chlorides extraction was investigated at 25 ± 0.1 °C by using flame atomic absorption and the result is that the ability of extraction in solvents as follows: C 6H 5NO 2 > CHCl 3 > CH 2Cl 2 and the compositions of the extracted species have been determined. The metal picrate extraction was investigated at 25 ± 0.1 °C by using UV-visible spectrometry. As well that the extraction of picrates metal such as UO 22+ and Hg 2+ with Schiff base(I) in absence and presence of 2-(2-aminoethyl) pyridine was investigated in chloroform. The extraction results revealed the presence of neutral donors 2-(2-aminoethyl) pyridine shifts the extraction percentage curves towards higher pH region, indicating a synergistic effect of this donors on extraction of UO 22+ and Hg 2+ by the studied Schiff base (I).

  10. Formulation of ternary complexes of glyburide with hydroxypropyl-β-cyclodextrin and other solubilizing agents and their effect on release behavior of glyburide in aqueous and buffered media at different agitation speeds.

    Science.gov (United States)

    Singh, Sachin Kumar; Srinivasan, K K; Singare, Dhananjay S; Gowthamarajan, K; Prakash, Dev

    2012-11-01

    Glyburide, a sulfonylurea derivative, widely used as hypoglycaemic agent. In the present study, an attempt has been made to investigate the most effective third component which can be used with hydroxylpropyl-β-cyclodextrin (HPβCd) to form a ternary complex with glyburide in order to enhance its dissolution rate, as well as reduce the amount of HPβCd used for formulating the binary complex with glyburide. Moreover, the objective of this study was also to develop a discriminatory dissolution media in order to discriminate the effect of the different solubilizing agents used for formulating the ternary complex system. Sodium lauryl sulphate, Poloxamer-188, Polyvinylpyrrolidone K-30, lactose and L-arginine were used to formulate ternary system along with HPβCd and glyburide. The ternary system formulated with glyburide:HPβCd:L-arginine in a proportion of 1:1:0.5 has shown the fastest dissolution rate when compared to other solubilizing agents. Unbuffered aqueous media with stirring speed 50 rpm has produced the most discriminatory dissolution profiles. The DSC thermograms and the powder X-ray analysis revealed the decrease in crystallinity of the drug. This was an indication of amorphous solid dispersion or molecular encapsulation of the drug into the cyclodextrin cavity. PMID:22283512

  11. Risks of using membrane filtration for trace metal analysis and assessing the dissolved metal fraction of aqueous media--a study on zinc, copper and nickel.

    Science.gov (United States)

    Hedberg, Yolanda; Herting, Gunilla; Wallinder, Inger Odnevall

    2011-05-01

    Membrane filtration is commonly performed for solid-liquid separation of aqueous solutions prior to trace metal analysis and when assessing "dissolved" metal fractions. Potential artifacts induced by filtration such as contamination and/or adsorption of metals within the membrane have been investigated for different membrane materials, metals, applied pressures and pre-cleaning steps. Measurements have been conducted on aqueous solutions including well-defined metal standards, ultrapure water, and on runoff water from corroded samples. Filtration using both non-cleaned and pre-cleaned filters revealed contamination and adsorption effects, in particular pronounced for zinc, evident for copper but non-significant for nickel. The results clearly show these artifacts to be non-systematic both for non-cleaned and pre-cleaned membranes. The applied pressure was of minor importance. Measurements of the labile fraction by means of stripping voltammetry clearly elucidate that membrane filtration followed by total metal analysis cannot accurately assess the labile or the dissolved metal fraction. PMID:21367497

  12. An Environmentally Benign System for Synthesis of β-Hydroxylketones: L-Histidine Asymmetrically Catalyzed Direct Aldol Reactions in Aqueous Micelle and Water-like Media

    Institute of Scientific and Technical Information of China (English)

    PENG Yi-Yuan; PENG Shu-Jun; DING Qiu-Ping; WANG Qi; CHENG Jin-Pei

    2007-01-01

    The first histidine catalyzed direct aldol reactions of ketones with nitrobenzaldehydes in water and in poly(ethylene glycol) (PEG) were reported. It reveals that histidine is a good aldol catalyst for synthesis of β-hydroxylketones in water and in PEG, giving good to excellent yields of the respective products. Better enantioand regioselectivity were achieved using low molecular weight PEG as the media. The results show that histidine and PEG-200 or -300 may constitute a promising environmentally benign system for asymmetric synthesis of β-hydroxylketones.

  13. Carboxylate Functionalized Chitosan/Bentonite Composite Matrix as a Cation Exchanger for the Removal of Pb(II From Aqueous Media: Kinetic and Equilibrium Studies

    Directory of Open Access Journals (Sweden)

    T. S. Anirudhan

    2015-06-01

    Full Text Available A novel composite matrix polymethacrylic acid-grafted Chitosan/Bentonite (PMAA-g-CS/B was prepared through graft copolymerization reaction of methacrylic acid and chitosan in the presence of bentonite and N,N’- methylene-bisacrylamide as cross linker. The composite was well characterized using FTIR, XPS, SEM, TG/DTG, surface area analyzer and potentiometric titrations. The adsorption behavior of the composite towards Pb(II from water and simulated battery manufacturing wastewater was studied under varying operating conditions. The kinetics of adsorption as well as adsorption isotherms at different temperatures was studied. Adsorption-desorption experiments over four cycles illustrate the feasibility of the repeated uses of this composite for the extraction of Pb(II from aqueous solutions.

  14. Use of chemically derivatized n-type silicon photoelectrodes in aqueous media: photooxidation of iodide, hexacyanoiron(II), and hexaammineruthenium(II) at ferrocene-derivatized photoanodes

    Energy Technology Data Exchange (ETDEWEB)

    Bocarsly, A.B.; Walton, E.G.; Wrighton, M.S.

    1980-05-07

    A procedure is described for the chemical derivatization of the surface of n-type semiconductor photoanodes to yield photosensitive interfaces for use in a large number of thermodynamically uphill oxidation processes. (1,1'-ferrocenediyl)dichlorosilane was used to derivatize n-type Si to yield a photoanode that can be used under conditions where the naked (nonderivatized) n-type Si undergoes photoanodic corrosion yielding an insulating SiO/sub x/ surface layer. The results of use of this derivatized n-type Si in aqueous solutions to investigate the photooxidation of iodide, hexacyanoiron(II), and hexaammineruthenium(II) are reported. This type photoelectrode has an operation range that is nearly ideal from the point of solar energy conversion. (BLM)

  15. The self-assembly of copolymers with one hydrophobic and one polyelectrolyte block in aqueous media: a dissipative particle dynamics study.

    Science.gov (United States)

    Lísal, Martin; Limpouchová, Zuzana; Procházka, Karel

    2016-06-28

    The reversible self-assembly of symmetrical block copolymers consisting of one hydrophobic block and one ionizable polyelectrolyte block of the same length has been studied in aqueous solutions by dissipative particle dynamics simulations. In addition to three standard dissipative particle dynamics forces (conservative soft repulsion, dissipative and stochastic forces), explicit interaction between smeared charges on ions and on ionized polymer beads described by the electrostatic potential with appropriately localized charges was taken into account. The self-assembly and properties of formed core-shell micelles were investigated as functions of the degree of ionization for systems differing in the hydrophobicity of the non-ionized polyelectrolyte block and in the compatibility of the polymer blocks. This study shows that micelles undergo massive dissociation with increasing degree of ionization. The simulation data compare well with the predictions of scaling theories for systems with soluble polyelectrolytes on a semi-quantitative level and broaden the knowledge of systems in poor solvents. PMID:27254381

  16. Synthesis of Novel Polymeric Resins by Gamma Irradiation for Separation of In(III) ions from Cd(II) in Aqueous Media

    International Nuclear Information System (INIS)

    In this work, Zn(II)polymethacrylates and poly(acrylamide-acrylic acid) were prepared by gamma irradiation polymerization technique of the corresponding monomer at 30 kGy. The polymeric resins were mixed with Indium ions to determine its capacity in aqueous solutions using batch experiment. The adsorption efficiency of obtained polymeric resins toward In(III) and Cd(II) in different experimental conditions was established. Batch and column methods were applied for separation of indium and cadmium. The effects of various eluants such as H2SO4, NH4NO3, HNO3 and HCl on the recovery of both metal ions were studied. The polymeric resins may be regenerated using 3M HCl solutions.

  17. Nuclear renaissance, public perception and design criteria: An exploratory review

    International Nuclear Information System (INIS)

    There is currently an international drive to build new nuclear power plants, bringing about what is being termed a 'nuclear renaissance'. However, the public perception of nuclear energy has historically been, and continues to be, a key issue, particularly in light of the Fukushima nuclear incident. This paper discusses the disparity between perceived and calculated risks based on the last four decades of research into risk perception. The leading psychological and sociological theories, Psychometric Paradigm and Cultural Theory, respectively, are critically reviewed. The authors then argue that a new nuclear-build policy that promotes a broader approach to design incorporating a wider range of stakeholder inputs, including that of the lay public, may provide a means for reducing the perceived risk of a nuclear plant. Further research towards such a new approach to design is proposed, based on integrating expert and lay stakeholder inputs and taking into account broader socio-cultural factors whilst maintaining the necessary emphasis on safety, technological development, economics and environmental sustainability. - Highlights: → Globally, a number of countries are investing in or considering building new nuclear plants. → Public acceptance of nuclear safety is important to continuing new nuclear build efforts. → Theories are discussed attempting to explain the public perception of nuclear safety. → A socially informed design process is proposed which could assist in ensuring public support. → Further research to understand how this design process might be performed is proposed.

  18. Nuclear Renaissance in an Era of Anthropogenic Climate Change

    International Nuclear Information System (INIS)

    This paper substantiates the anthropogenic origin of climate change, demonstrates the resulting consequences, and thereby establishes the need for a nuclear renaissance over the next thirty years. First, the mechanisms behind the natural cycles in global warming, specifically, cycles of precession and eccentricity in Earth's orbit, as measured in ice cores, are compared to the mechanisms of anthropogenic warming, revealing the scientific basis for the observed correlation between carbon dioxide and temperature. Second, the resulting climate change is exemplified by key results from experiments performed by the author in the Arctic and at the South Geographic Pole, and the author's experience of Switzerland's costliest natural catastrophe - the flash flood of 2005. Third, although facing barriers such as research and development requirements, political will and public acceptance, the potential for nuclear power to triple to 1,000 GWe by 2050 would mitigate climate change by holding carbon dioxide concentration below 500 ppm, thereby challenging the younger nuclear generation to contribute to the most important issue facing humanity. (authors)

  19. Nuclear renaissance, public perception and design criteria: An exploratory review

    Energy Technology Data Exchange (ETDEWEB)

    Goodfellow, Martin J., E-mail: Martin.Goodfellow@postgrad.manchester.ac.uk [School of Chemical Engineering and Analytical Science, The Mill, Sackville Street, University of Manchester, Manchester M13 9PL (United Kingdom); Rolls-Royce, SINA-CNB-1, PO Box 31, Derby DE24 8BJ (United Kingdom); Williams, Hugo R. [Space Research Centre, University of Leicester, University Rd., Leicester LE1 7RH (United Kingdom); Azapagic, Adisa [School of Chemical Engineering and Analytical Science, The Mill, Sackville Street, University of Manchester, Manchester M13 9PL (United Kingdom)

    2011-10-15

    There is currently an international drive to build new nuclear power plants, bringing about what is being termed a 'nuclear renaissance'. However, the public perception of nuclear energy has historically been, and continues to be, a key issue, particularly in light of the Fukushima nuclear incident. This paper discusses the disparity between perceived and calculated risks based on the last four decades of research into risk perception. The leading psychological and sociological theories, Psychometric Paradigm and Cultural Theory, respectively, are critically reviewed. The authors then argue that a new nuclear-build policy that promotes a broader approach to design incorporating a wider range of stakeholder inputs, including that of the lay public, may provide a means for reducing the perceived risk of a nuclear plant. Further research towards such a new approach to design is proposed, based on integrating expert and lay stakeholder inputs and taking into account broader socio-cultural factors whilst maintaining the necessary emphasis on safety, technological development, economics and environmental sustainability. - Highlights: > Globally, a number of countries are investing in or considering building new nuclear plants. > Public acceptance of nuclear safety is important to continuing new nuclear build efforts. > Theories are discussed attempting to explain the public perception of nuclear safety. > A socially informed design process is proposed which could assist in ensuring public support. > Further research to understand how this design process might be performed is proposed.

  20. Gay re-readings of the Harlem Renaissance poets.

    Science.gov (United States)

    Woods, G

    1993-01-01

    In the light of the long-established fact of their homosexuality or bisexuality, it is high time for the cluster of "Negro Renaissance" poets, Countee Cullen, Langston Hughes, Claude McKay, and Richard Bruce Nugent, to be reappraised by and for gay readers. This paper seeks to develop gay reading strategies in relation to the poems of these writers, in order to reveal for contemporary readers likely subtexts which, at the time of their writing, were publicly read as bearing on race alone. It is often possible to read a particular poem as referring (in images such as that of the social outcast) to either racial or sexual oppression, interchangeably; and possibly, therefore, to both at once, by way of an implicit comparison. Likewise, poems on miscegenation can just as well be read, via the theme of forbidden love, as referring to homosexuality. The fact that most published critical readings deal only with the racial issue does not invalidate the likelihood that the poem can be, and indeed requires to be, read as referring, also, to sexuality. Gay readings emerge, then, not merely from these writers' representations of attractive men and boys, but also in the midst of their most famously anti-racist themes. PMID:8113612

  1. The renaissance of primary aldosteronism: what has it taught us?

    Science.gov (United States)

    Stowasser, Michael; Gordon, Richard Douglas

    2013-06-01

    The growing realisation since the early 1990s that primary aldosteronism (PA) is a much more common cause of hypertension than previously thought, and that aldosterone excess has adverse effects that are at least partly independent of blood pressure, has been the main driving force for a renaissance in clinical and research interest in PA. This has generated a wealth of new knowledge regarding (1) PA's high prevalence, (2) the extent of non-BP dependent cardiovascular and renal organ damage and morbidity and reduced quality of life associated with PA, all of which appear to be at least partly ameliorated by specific treatment (especially surgical) directed against excessive aldosterone action, (3) the diversity of adrenal histopathology associated with PA and the need to subdivide patients based on glucocorticoid remediability (by genetic testing for the hybrid gene mutation causing familial hyperaldosteronism type I, FH-I) and lateralisation on adrenal venous sampling in order to ensure optimal treatment, (4) the value of elucidating genetic bases for PA in terms of improving detection, understanding of pathogenesis and treatment, as illustrated by the determination of the genetic basis of FH-I, and (5) the genetic basis of more common forms including aldosterone-producing adenoma. From the clinical perspective, the principal lesson learnt is that PA, being a common cause of cardiovascular morbidity and reduced quality of life reversible by specific treatment, is worth looking for. PMID:23402683

  2. Can we have a nuclear renaissance without nuclear proliferation?

    International Nuclear Information System (INIS)

    Nuclear energy holds the potential of a sustainable, affordable, and carbon-free source available this century on a scale that can help meet the world's growing need for energy and slow the pace of global climate change. However, the factor of millions gain in energy release from nuclear fission compared to all conventional energy sources has also been used to create explosives of unprecedented lethality and, hence, poses a serious challenge to the global expansion of nuclear energy. The promise and peril of nuclear energy share a common technological foundation. Pursuit of a civilian fuel cycle-making fuel, reactors to burn the fuel, and the back end to deal with nuclear waste, including the option of recycling some of the valuable byproducts of burning reactor fuel-allows nations to develop the capability to produce fuel for nuclear weapons; either highly enriched uranium (HEU) or plutonium. However, restricting supply of nuclear technologies through international treaties, norms and arrangements will only slow down, but not stop determined proliferators. In the long term, it will be imperative to curb the demand for nuclear weapons. A nuclear renaissance will be possible only if nations of the world cooperate to control the proliferation of nuclear weapons and, eventually, to eliminate them. The 2010 Non-Proliferation Conference will be a good place to demonstrate that such cooperation is possible

  3. Nuclear energy renaissance and reactor physics. Enlightenment of PHYSOR'08

    International Nuclear Information System (INIS)

    In relation to world's growing energy demands and concerns on global warming, nuclear energy as a sustainable resource is in its new period of renaissance. This is reflected in the record number of 447 papers on the International Conference on the Physics of Reactors--PHYSOR'08 held in Switzerland in 2008. The contents of these papers include the developments and frontiers in various directions of reactor physics. Featured by vast area of subjects, these emphasize the fact that the scope of the reactor physicist's R and D interests has expands considerably in recent years. The main keynote addresses and technical plenary lectures are briefly introduced. Some items concerned by the conference, such as: the status and perspective of nuclear energy's R and D, deployment and policy in main nuclear nations, the potential role of nuclear energy in mitigation global warming and slow down the GHG release, the sustainability of resource for nuclear energy utilization. Status and outlook about the needs of research and test facilities required in nuclear energy development, etc. are discussed. (authors)

  4. Nuclear Renaissance in an Era of Anthropogenic Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Bird, John [Bruce Power, Box 3000 B06, Tiverton, Ontario N0G 2T0 (Canada)

    2008-07-01

    This paper substantiates the anthropogenic origin of climate change, demonstrates the resulting consequences, and thereby establishes the need for a nuclear renaissance over the next thirty years. First, the mechanisms behind the natural cycles in global warming, specifically, cycles of precession and eccentricity in Earth's orbit, as measured in ice cores, are compared to the mechanisms of anthropogenic warming, revealing the scientific basis for the observed correlation between carbon dioxide and temperature. Second, the resulting climate change is exemplified by key results from experiments performed by the author in the Arctic and at the South Geographic Pole, and the author's experience of Switzerland's costliest natural catastrophe - the flash flood of 2005. Third, although facing barriers such as research and development requirements, political will and public acceptance, the potential for nuclear power to triple to 1,000 GWe by 2050 would mitigate climate change by holding carbon dioxide concentration below 500 ppm, thereby challenging the younger nuclear generation to contribute to the most important issue facing humanity. (authors)

  5. Preliminary findings of the effect of surface finish and coatings on PuO2 contamination hold-up and ease of decontamination in aqueous and non-aqueous media

    International Nuclear Information System (INIS)

    The application of temporary and permanent coatings for the reduction of α-activity hold-up and increased ease of decontamination has been reviewed and a variety of surface treatments and coatings identified as being worthy of investigation. A range of specimens have been prepared with hard coatings and smooth surfaces. A number of adhesive films, paints and lacquers have been applied to mild and stainless steel substrates. In order to compare the different surfaces, a standard contamination technique using a mechanical wiper has been developed to reproducibly contaminate the materials with PuO2. A standard decontamination test using water/Decon 75 or Arklone X is being used to compare the ease of decontamination. Preliminary experiments have shown that the smoothest surface finishes have the lowest activity hold-up and are more easily cleaned. Due to the superior level of micro-smoothness attainable on metals, these showed a significantly lower activity retention than the organic coatings examined to date. A comparison of the relative efficiency of cleaning in Decon 75 and Arklone X showed that generally speaking metal surfaces were cleaned equally well by both media, while the unaged organic surfaces were decontaminated more thoroughly in Arklone X, though the differences were somewhat marginal. (author)

  6. Calix[4]arene functionalized gold nanoparticles for colorimetric and bare-eye detection of iodide in aqueous media and periodate aided enhancement in sensitivity

    International Nuclear Information System (INIS)

    A water- soluble p-sulphonatocalix[4]arene was synthesized and anchored onto the surface of gold nanoparticles (AuNPs) in aqueous medium. The conjugate was characterized by IR, UV–Vis and TEM analysis. This material responds to iodide in giving a color change from pink to blue which is easily detectable with bare eyes. While periodate itself does not cause any spectral changes, a substantial spectral change can be seen in the presence of traces of iodide. The lower detection limit for iodide in the absence of periodate is 2.5 μM, which is further lowered to 80 nM in presence of periodate. A mechanistic study revealed that the chemisorption of the ions I− and I3−, formed by the reaction I− and periodate on the surface of AuNPs resulted in spontaneous oxidation of the anions. The electron transfer changes the size and morphology of the nanoparticles and results in the color change. The method is specific for iodide. It was successfully applied to the determination of I− in (spiked) waters and in solutions of iodized edible salt. (author)

  7. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Silvia [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Taboada, Pablo [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)]. E-mail: fmpablo@usc.es; Mosquera, Victor [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)

    2005-04-04

    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 {sup o}C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, {delta}HITCi, entropy, {delta}SITCi, Gibbs energy, {delta}GITCi, binding constant, KITCi and the number of binding sites, n{sub i}, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and n{sub i} were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  8. Synthesis and crystal structure of imidazole containing amide as a turn on fluorescent probe for nickel ion in aqueous media. An experimental and theoretical investigation

    Science.gov (United States)

    Annaraj, B.; Mitu, L.; Neelakantan, M. A.

    2016-01-01

    Imidazole containing amide fluorescence probe (PAIC) for Ni2+ was designed and successfully synthesized in good yield by reaction between 1-methyl-1H-imidazole-2-carboxylic acid and L-phenylalanine methyl ester. The probe was characterized by FTIR, 1H NMR, ESI-MS, UV-vis and fluorescence spectroscopy. Single crystal XRD analysis reveals that PAIC crystallizes in a monoclinic crystal lattice system with the space group of P21/n. Chemosensor property of PAIC was tested against different metal ions by UV-vis and fluorescent techniques in aqueous medium. Test results show that PAIC has high selectivity for Ni2+ compared to other metal ions (Na+, K+, Ca2+, Ag+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Zn2+ and Pb2+). Time-dependent density functional theory (TD-DFT) and configuration interaction singles (CIS) calculations were carried out to understand the sensing mechanism. The practical applicability of PAIC was tested in real water samples.

  9. Synthesis and self-assembly behavior of amphiphilic diblock copolymer dextran-block-poly(ε-caprolactone (DEX-b-PCL in aqueous media

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available An amphiphilic diblock copolymer, dextran-block-poly(ε-caprolactone (DEX-b-PCL, with a series of welldefined chain lengths of each block was prepared by conjugating a dextran chain with a PCL block via aza-Michael addition reaction under mild conditions. For the dextran block, samples with relatively uniform molecular weight, 3.5 and 6.0 kDa, were used, and the PCL blocks were prepared via ring-opening polymerization at defined ratios of ε-caprolactone to initiator in order to give copolymers with mass fraction of dextran (fDEX ranging from 0.16 to 0.45. When these copolymers were allowed to self-assemble in aqueous solution, the morphology of assembled aggregates varied as a function of fDEX when characterized by transmission electron microscope (TEM, fluorescence microscope (FM and dynamic laser scattering (DLS. As fDEX decreases gradually from 0.45 to 0.16, the morphology of the copolymer assembly changes from spherical micelles to worm-like micelles and eventually to polymersomes, together with an increase in particle sizes.

  10. Extraction of molybdenum by the di-n-butyl 2.2.N.hydroxyhexanamide (tri-n-butylacetohydroxamic acid) from aqueous acidic media

    International Nuclear Information System (INIS)

    The design of a new industrial process for the production of the fission product 99 Mo, led to study of the extraction of 99Mo(VI) by the tri-n-butylacetohydroxamic acid (TBAH). Due to the large affinity of TBAH for Mo(VI), the study was conducted with unusual experimental conditions : the concentrations of the extracting molecule and metallic ion were very low, typically CTBAH = 10-5 M and CMo(VI) = 10-8 M. The overall extraction system was described using a mathematical model quite simple, which, in particular, takes into account all the Mo(VI) species present in the aqueous phase. When the extractions were carried out from a perchloric acid medium, two different extraction mechanisms of Mo(VI) were identified : for CHC104 3, the extraction of Mo(VI) corresponds to a cationic exchange, whereas for CHC104 > 3 mol/dm3, a neutral Mo(VI) compound is extracted. Moreover it was found that the extracting system Mo(VI)/TBAH is extremely sensitive to the temperature. It is thus possible to change the way of the transfer of Mo(VI) between the two phases, by control of the temperature of the mixture : the extraction is carried out at room temperature and the back-extraction at elevated temperature

  11. Bioinspired thermo- and pH-responsive polymeric amines: multimolecular aggregates in aqueous media and matrices for silica/polymer nanocomposites.

    Science.gov (United States)

    Danilovtseva, Elena N; Aseyev, Vladimir; Belozerova, Olga Yu; Zelinskiy, Stanislav N; Annenkov, Vadim V

    2015-05-15

    Polymeric amines have been intensively studied for application in smart systems and as matrices for the design of composite materials, including bioinspired substances. A new thermo- and pH-responsive polymer was obtained by radical polymerization of N-(3-(diethylamino)propyl)-N-methylacrylamide. Upon heating, the polymer precipitated from aqueous solutions above pH 9; the observed cloud point was dependent on the polymer concentration and decreased from 95°C at pH 9 to 40°C at pH 11. The basicity of the polymer decreased at elevated temperatures owing to an increase in the hydrophobicity-driven compaction of the macromolecules. Dynamic light scattering analysis demonstrated that the formation of large multimolecular associates with radius 1000-2000 nm was initiated from 1 to 2°C below the cloud point. The new polymer is demonstrated to be an effective matrix for various siliceous composite structures, including 200-300 nm solid spherical raspberry-like particles and hollow hemispherical particles of more than 1000 nm diameter. Condensation of silicic acid in the presence of polymeric amines is a model reaction in biosilicification studies, and the obtained data are also discussed from the perspective of the matrix hypothesis for biosilica formation. PMID:25646785

  12. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study

    Science.gov (United States)

    Barbosa, Silvia; Taboada, Pablo; Mosquera, Victor

    2005-04-01

    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 °C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, ΔHITCi, entropy, ΔSITCi, Gibbs energy, ΔGITCi, binding constant, KITCi and the number of binding sites, ni, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and ni were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  13. Fluorometric selective detection of fluoride ions in aqueous media using Ag doped CdS/ZnS core/shell nanoparticles.

    Science.gov (United States)

    Boxi, Siddhartha Sankar; Paria, Santanu

    2016-01-14

    The presence of fluoride ions in drinking water plays an important role in human health. For that reason, maintaining the optimum concentration of fluoride ions in drinking water is essential, as both low and excess (above the permissible level) concentrations can cause different health problems, such as fluorosis, urolithiasis, kidney failure, cancer, and can even lead to death. So, development of a simple and low cost method for the detection of fluoride ions in water is highly desirable. In this study, a fluorometric method based on Ag-CdS/Ag-ZnS core/shell nanoparticles is developed for fluoride ion detection. The method was tested in aqueous solution at different pH values. The selectivity and sensitivity of the fluorescence probe was checked in the presence of other anions (Cl(-), Br(-), I(-), NO3(-) SO4(2-), HCO3(-), HPO4(2-), CH3COO(-), and H2PO4(-)) and found there is no significant interference of these associated ions. The fluoride ion concentration was varied in the range 190-22 800 μg L(-1) and a lower detection limit was obtained as 99.7 μg L(-1). PMID:26645767

  14. Vesalius and the emergence of veridical representation in Renaissance anatomy.

    Science.gov (United States)

    Russell, Gül A

    2013-01-01

    The Renaissance marks the introduction of veridical representation of anatomical structure into printed books. For centuries, anatomy that had relied solely on textual description and the authority of the written word was transformed. An existing graphic tradition only visualized function within a humoral theory, schematically "naming the parts" or mapping the "uses of the parts" for mnemonic purposes. In the sixteenth century, anatomists and artist began to apply their knowledge and skills to present the "fabric" of the dissected human body with increasing detail and accuracy, exemplified by the naturalistic illustrations of the brain in Vesalius' De humani corporis fabrica (Basel, 1543). How did this transformation occur? Among the causal factors, the importance the humanist textual scholarship will be shown not only in the recovery of the anatomical writings of Galen (129-ca. 216), in particular, but also in providing a model in establishing anatomical "truth" by a method of "comparison." It will be argued that Vesalius' comparative approach in dissection, using both human and animal preparations against Galen's textual description, paved the way for cumulative observations of greater detail, which in turn required the representational skills of artists. An analysis of Vesalius' views between 1538 and 1543 shows a shift in the use of illustrations from serving as a visual record to compensate for limited access to cadavers in teaching, to becoming an indispensable tool to accurately convey detailed anatomical structure through the medium of printing. With the Fabrica, morphology became divorced from humoral function and enduring paradigms established that dominated until the nineteenth century. PMID:24041275

  15. Smart Approach for In Situ One-Step Encapsulation and Controlled Delivery of a Chemotherapeutic Drug using Metal-Organic Framework-Drug Composites in Aqueous Media.

    Science.gov (United States)

    Adhikari, Chandan; Chakraborty, Anjan

    2016-04-01

    Controlled release of an anticancer drug, doxorubicin (dox), from metal-organic framework (MOF)-drug composites is demonstrated under different external stimuli. 1,3,5-Benzenetricarboxylic acid (H3 BTC) is used as an organic ligand, and iron acetate and zinc nitrate are used as metal sources to synthesize Fe-BTC and Zn-BTC MOFs, which are known to be biocompatible. The in situ formation of MOF-drug composites demonstrates high drug loading capacity compared to conventional methods. The present methodology is devoid of any extra steps for loading the drug after synthesis. Moreover, the drug loading is also independent of pore size of the MOF as the drug molecules are embedded inside the MOF during their in situ formation. The drug release was monitored under external stimuli including change to acidic pH and the presence of biocompatible liposomes for a period of more than 72 h. Steady-state fluorescence spectroscopy is used to monitor the drug release as a function of time and confocal laser scanning microscopy is used to unravel the post-release fate of doxorubicin in the presence of liposomes. It is found that drug release rate is higher for the Zn-BTC-dox composite than for the Fe-BTC-dox composite. This is attributed to the stronger binding between dox and Fe-BTC than that between dox and Zn-BTC. This study highlights a novel approach for the preparation of MOF-drug composites in an aqueous medium for future biomedical applications. PMID:26752093

  16. Andreas Vesalius as a renaissance innovative neuroanatomist: his 5th centenary of birth

    Directory of Open Access Journals (Sweden)

    Marleide da Mota Gomes

    2015-02-01

    Full Text Available Andreas Vesalius (1514-1564 is considered the Father of Modern Anatomy, and an authentic representative of the Renaissance. His studies, founded on dissection of human bodies, differed from Galeno, who based his work on dissection of animals, constituted a notable scientific advance. Putting together science and art, Vesalius associated himself to artists of the Renaissance, and valued the images of the human body in his superb work De Humani Corporis Fabrica.This paper aims to honor this extraordinary European Renaissance physician and anatomist, who used aesthetic appeal to bind text and illustration, science and art. His achievements are highlighted, with an especial attention on neuroanatomy. Aspects about his personal life and career are also focused.

  17. The Love Theme of the Renaissance——A Comment on Two Renaissance Poems

    Institute of Scientific and Technical Information of China (English)

    李国英

    2009-01-01

    Poetry is one of the most important literary forms in the English Renaissance.Love is an eternal theme of the tremendous amount of the English Renaissance poems.In the two famous love poems,Valediction:Forbidding Mourning and The Passionate Shepherd to His Love,the poets express their strong feelings in different ways.By employing the method of literature review and centering around the two vivid love poems,this paper attempts to explore their images,themes and many other literary characteristics.The objective of it is to help us to have a deeper understanding about the literature in the English Renaissance,and know more about love which is a beautiful emotion.

  18. ‘The 19th-century construction of the Renaissance’: Katherine Wheeler, Victorian Perceptions of Renaissance Architecture, Farnham England and Burlington, Vermont: Ashgate, 2014

    Directory of Open Access Journals (Sweden)

    Medina Lasansky

    2014-12-01

    Full Text Available Katherine Wheeler’s Victorian Perceptions of Renaissance Architecture provides a study of the architecture profession and the history of Renaissance architecture in nineteenth century England. Establishing a canon of Renaissance architectural history was key to the rise of architectural professionalism as well as the education of the architect. As we discover, the study of the Renaissance influenced design in England on all scales while also influencing the design of the architect himself.

  19. Renaissance Science and Literature: Benedetti, Ovid and the Transformations of Phaeton's Myth after Copernicus

    Science.gov (United States)

    Omodeo, Pietro Daniel

    2014-03-01

    This paper aims at showing the close ties between Renaissance literature and science as emerge from the use and the transformation, in a post-Copernican context, of the myth of Phaeton—according to Greek mythology: the boy who tried to conduct the chariot of the Sun and died in this attempt. G.B. Benedetti's analysis and criticism of Ovid's Metamorphoses, book two, provides an insight into this literary and scientific issue. Astronomical poems and variations of Phaeton's myth by other illustrious Renaissance men—including T. Brahe and King James of Scotland and England—are taken into account, as well.

  20. Coding one-sided violence from media reports

    OpenAIRE

    Otto, Sabine

    2013-01-01

    Event datasets on political violence, which are comprised of coded collected news reports, have enjoyed a renaissance within the academic community. The inclusion of civilian fatalities within these datasets is a promising and welcomed advancement regarding the availability of data on one-sided violence. However, these datasets are often criticised due to their heavy reliance on media records, which may be tainted by biases. So far, little attention has been paid to the specific problems that...

  1. Differentiation and characterization of isotopically modified silver nanoparticles in aqueous media using asymmetric-flow field flow fractionation coupled to optical detection and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gigault, Julien [National Institute of Standards and Technology, Material Measurement Laboratory, 100 Bureau Drive Stop 8520, Gaithersburg, MD 20899-8520 (United States); Hackley, Vincent A., E-mail: vince.hackley@nist.gov [National Institute of Standards and Technology, Material Measurement Laboratory, 100 Bureau Drive Stop 8520, Gaithersburg, MD 20899-8520 (United States)

    2013-02-06

    Highlights: ► Isotopically modified and unmodified AgNPs characterization by A4F-DAD-MALS–DLS-ICP-MS. ► Size-resolved characterization and speciation in simple or complex media. ► Capacity to detect stable isotope enriched AgNPs in a standard estuarine sediment. ► New opportunities to monitor and study fate and transformations of AgNPs. -- Abstract: The principal objective of this work was to develop and demonstrate a new methodology for silver nanoparticle (AgNP) detection and characterization based on asymmetric-flow field flow fractionation (A4F) coupled on-line to multiple detectors and using stable isotopes of Ag. This analytical approach opens the door to address many relevant scientific challenges concerning the transport and fate of nanomaterials in natural systems. We show that A4F must be optimized in order to effectively fractionate AgNPs and larger colloidal Ag particles. With the optimized method one can accurately determine the size, stability and optical properties of AgNPs and their agglomerates under variable conditions. In this investigation, we couple A4F to optical absorbance (UV–vis spectrometer) and scattering detectors (static and dynamic) and to an inductively coupled plasma mass spectrometer. With this combination of detection modes it is possible to determine the mass isotopic signature of AgNPs as a function of their size and optical properties, providing specificity necessary for tracing and differentiating labeled AgNPs from their naturally occurring or anthropogenic analogs. The methodology was then applied to standard estuarine sediment by doping the suspension with a known quantity of isotopically enriched {sup 109}AgNPs stabilized by natural organic matter (standard humic and fulvic acids). The mass signature of the isotopically enriched AgNPs was recorded as a function of the measured particle size. We observed that AgNPs interact with different particulate components of the sediment, and also self-associate to form

  2. Differentiation and characterization of isotopically modified silver nanoparticles in aqueous media using asymmetric-flow field flow fractionation coupled to optical detection and mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► Isotopically modified and unmodified AgNPs characterization by A4F-DAD-MALS–DLS-ICP-MS. ► Size-resolved characterization and speciation in simple or complex media. ► Capacity to detect stable isotope enriched AgNPs in a standard estuarine sediment. ► New opportunities to monitor and study fate and transformations of AgNPs. -- Abstract: The principal objective of this work was to develop and demonstrate a new methodology for silver nanoparticle (AgNP) detection and characterization based on asymmetric-flow field flow fractionation (A4F) coupled on-line to multiple detectors and using stable isotopes of Ag. This analytical approach opens the door to address many relevant scientific challenges concerning the transport and fate of nanomaterials in natural systems. We show that A4F must be optimized in order to effectively fractionate AgNPs and larger colloidal Ag particles. With the optimized method one can accurately determine the size, stability and optical properties of AgNPs and their agglomerates under variable conditions. In this investigation, we couple A4F to optical absorbance (UV–vis spectrometer) and scattering detectors (static and dynamic) and to an inductively coupled plasma mass spectrometer. With this combination of detection modes it is possible to determine the mass isotopic signature of AgNPs as a function of their size and optical properties, providing specificity necessary for tracing and differentiating labeled AgNPs from their naturally occurring or anthropogenic analogs. The methodology was then applied to standard estuarine sediment by doping the suspension with a known quantity of isotopically enriched 109AgNPs stabilized by natural organic matter (standard humic and fulvic acids). The mass signature of the isotopically enriched AgNPs was recorded as a function of the measured particle size. We observed that AgNPs interact with different particulate components of the sediment, and also self-associate to form

  3. The Gaze of the Soul and of the Angel in the Renaissance Philosophy of Marsilio Ficino

    Directory of Open Access Journals (Sweden)

    Marko Uršič

    2015-05-01

    Full Text Available The Renaissance rediscovered the soul as the focus of the universe. Marsilio Ficino calls the soul the “bond of the world” (copula mundi, because it connects the earth and the heaven, immanence and transcendence, time and eternity. On the other hand, the centre of the world becomes more and more relative during the Renaissance period, and individual souls live more and more in their particular times and spaces. In Renaissance paintings, a soul's point of view is determined by perspective, as developed by Masaccio, Fra Angelico, Piero della Francesca et al., and the very position of the eye also features as a “symbolic form” (Erwin Panofsky. However, above each individual and “mobile” soul there are the wings of the “motionless” angel: super animam mobilem est immobilis angelus, as Ficino says in his renaissance Christianity, in reviewing the Platonic-Gnostic myth of the omnipresent angelic gaze. In the archetype of the angel Ficino perceives a metaphor for the all-knowing Intellect, towards which the human soul ascends. Following the iconology of Ernst Gombrich, this paper also takes notice of the influence of Ficino's philosophy on Botticelli's paintings.

  4. The Effect of School Renaissance on TAAS Scores in the McKinney ISD

    Science.gov (United States)

    Nunnery, John A.; Ross, Steven M.; Goldfeder, Elizabeth

    2003-01-01

    The present research is a third-party study of the effects of the School Renaissance (SR) comprehensive school reform (CSR) model on student achievement in 11 elementary and middle schools in Texas. The primary measures used in the study were the Texas Learning Index (TLI) reading and mathematics scores obtained through administration of the Texas…

  5. Renaissance or a Backward Step? Disparities and Tensions in Two New Swedish Pathways in VET

    Science.gov (United States)

    Berglund, Ingrid; Loeb, Ingrid Henning

    2013-01-01

    This article builds on results from studies of two new pathways in Swedish upper secondary VET. A major reform was launched in 2011 and the restructuring was presented by the Minister of Education as a "renaissance for VET education". The conclusion of the Upper Secondary Commission is that "students shall be more specialised within…

  6. Renaissance Architecture of Central Scheme: Jerónimo Quijano and his Immediate Environment

    Directory of Open Access Journals (Sweden)

    Antonio Luis López González

    2015-10-01

    As references to Quijano´s architectural approach in his Hispanic environment, it should reflect upon certain reminiscences to Renaissance works in Eastern Andalusia, his direct influence in the Government of Orihuela and subsequently some of his possible influences in the Valencian territory.

  7. Italian Renaissance and Japanese Zen Gardens: An Approach for Introducing Cultural Landscapes.

    Science.gov (United States)

    Purkayastha, Bandana

    1995-01-01

    Presents a method for teaching about cultural landscapes in introductory geography classes by comparing Italian Renaissance gardens with Japanese Zen gardens. Discusses the background and attributes of both garden types. Maintains that, by contrasting the two traditions, it is possible to illustrate cultural landscapes. (CFR)

  8. Renaissance Educational Consortium Ensuring Individualized Progress in Technology and Science (RECEIPTS)

    Science.gov (United States)

    Caddell, Esther Harte; And Others

    1975-01-01

    Describes the rationale for, development of, and activities of the Renaissance Educational Consortium Ensuring Individualized Progress in Technology and Science (RECEIPTS). The effort is designed to build a consortium of community resources with a focus on science and technology in order to combat the problems of low academic motivation and…

  9. Multiple identifications and the dialogical self: Maori youngsters and the cultural renaissance

    NARCIS (Netherlands)

    Meijl, A.H.M. van

    2006-01-01

    The renaissance of Maori culture and tradition has played a significant role in the political campaigns of New Zealand's indigenous population over the past few decades. At the same time, however, it has brought to light that many Maori youngsters are unable to construct a cultural identity in terms

  10. Ideas on Moral and Civil Upbringing of Personality in Italian and Ukrainian Pedagogy During the Renaissance

    Directory of Open Access Journals (Sweden)

    Petruk Natalia

    2015-12-01

    Full Text Available Important aspects of moral and civic upbringing of personality based on studying the experience of humanist pedagogy establishment in the Italian Renaissance in XIV-XV centuries and the Ukrainian Renaissance in XVI-XVII centuries have been reviewed in the article. It has been found out that under the influence of Renaissance in XVI-XVII centuries Ukrainian pedagogy progressed not only in the Orthodox Christian paradigm of thinking, but was greatly enriched by the humanistic ideas of European origin as well and the matter of a person, a bright personality, endowed with unique personality traits, high ethical and Christian virtues, active and dynamic, was crucial for the forming of humanistic pedagogy. This resulted in increasing interest of Ukrainian philosophers to human problems, establishment of the value of personality, awareness of the importance of education and science in life. Intellect, education, moral virtues and work became the greatest personal qualities in works of Italian and Ukrainian humanists. Pedagogical culture during the Renaissance was also determined by ideas of civil humanism, need for patriotic education and personal action for the common good. Formation of civic sense and responsibility for own actions were of great importance.

  11. Study of Italian Renaissance sculptures using an external beam nuclear microprobe

    International Nuclear Information System (INIS)

    The use of an extracted proton micro-beam for the PIXE analysis of glazes is discussed in the context of the growing interest in the creation of an analytical database on Italian Renaissance glazed terracotta sculptures. Some results concerning the frieze of an altarpiece of the Louvre museum, featuring white angels and cherubs heads, are presented

  12. “Turn on/off” proton transfer based fluorescent sensor for selective detection of environmentally hazardous metal ions (Zn{sup 2+}, Pb{sup 2+}) in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Nidhi; Tripathi, Ashish; Rana, Meenakshi [Department of Physics and Materials Science & Engineering, Jaypee Institute of Information Technology, Noida 201307, Uttar Pradesh (India); Kishore Goswami, Sudipta [Bruker India Scientific Pvt. Ltd., 22B Ruby Park South, Kolkata 700078, West Bengal (India); Pathak, Anirban [Department of Physics and Materials Science & Engineering, Jaypee Institute of Information Technology, Noida 201307, Uttar Pradesh (India); RCPTM, Joint Laboratory of Optics of Palacky University and Institute of Physics of Academy of Science of the Czech Republic, Faculty of Science, Palacky University, 17. listopadu 12, 771 46 Olomouc (Czech Republic); Chowdhury, Papia, E-mail: papia.chowdhury@jiit.ac.in [Department of Physics and Materials Science & Engineering, Jaypee Institute of Information Technology, Noida 201307, Uttar Pradesh (India)

    2015-09-15

    Sensing ability of fluorescence based chemosensor: Indole-7-carboxaldehyde (I7C) for environmentally hazardous metal ions (X{sup n+}=Zn{sup 2+}, Pb{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Cd{sup 2+}, Cr{sup 3+}, and Fe{sup 3+}) has been investigated. Based on excited state proton transfer (ESPT) phenomenon, the sensing capability of I7C is verified experimentally (UV–vis, FTIR, NMR) and theoretically (DFT, TD-DFT) in aqueous media. Chemical hardness (η), electrophilicity (ω) and electronic chemical potentials (μ) confirm the selective reactivity of I7C (N{sub c} and N{sub t} conformers) in the presence of metal ions by the formation of (1:1) metal ion: I7C complex (M{sub X}, M{sub X}{sup ⁎}). M{sub X}, M{sub X}{sup ⁎} are found to display excellent sensing capability for Zn{sup 2+} and Pb{sup 2+} ions. “Turn-On” response for Zn{sup 2+} is observed through the appearance of a new enhanced fluorescence at ~430 nm. By strong blue emission I7C establishes its strong candidature as “blue emitter”. “Turn-Off” response is observed for Pb{sup 2+} through the quenching of the existing fluorescence peak. - Highlights: • Indole-7-carboxaldehyde (I7C) shows “Turn-on” and “Turn-off” sensing for Zn{sup 2+} and Pb{sup 2+} ions. • I7C forms complex with metal ions (M{sub X}{sup ⁎}). • 27-Fold strong blue fluorescence due to M{sub Zn}{sup ⁎} formation indicates I7C as a good candidature to be used as blue emitter. • Computed (UV–vis absorption/emission, FTIR, NMR) data validate the experimental facts.

  13. Progress in Asymmetric Hydrogenation and Transfer Hydrogenation in Aqueous Media%水相不对称氢化及转移氢化反应研究进展

    Institute of Scientific and Technical Information of China (English)

    隋岩; 朱敏; 付雯

    2008-01-01

      Water has many advantages over the usual organic solvents in the catalytic reactions, for its safety, economy and no environmental pollution. From the industrial application point of view, the use of a two-phase system allows an easy separation of the products from the poisonous and usually expensive catalysts by simple phase separation. In this paper, the progress in organometallic-catalyzed asymmetric hydrogenation and transfer hydrogenation in aqueous media is reviewed. The emphasis is laid on the asymmetric hydrogenation and transfer hydrogenation of prochiral substrates such asα-acetamidoacrylic acid esters andβ-ketoesters in water. Their application is anticipated.%  在催化反应中以水代替常用的有机溶剂具有安全、经济、无环境污染等优点,而且在工业应用上,使用两相体系可以在反应完成之后,通过简单的相分离分离出产物和回收有毒的通常也是昂贵的催化剂,因此具有重要意义。本文综述了近年来以水为溶剂的不对称氢化及转移氢化反应的研究进展,重点介绍了前手性底物α-氨基丙烯酸酯及前手性酮的水相不对称氢化及转移氢化反应,并对其应用前景进行了展望。

  14. The World Nuclear University - A pillar of the nuclear renaissance

    International Nuclear Information System (INIS)

    The World Nuclear University was founded with the support of four leading international nuclear institutions - two of them inter-governmental organisations (IAEA and OECD/NEA), the other two bodies serving the industry and its operators (WNA and WANO). Inaugurated in September 2003 on the 50. anniversary of President Eisenhower's Atoms for Peace speech, the WNU started working a year later upon the arrival of the first staff members. Today there is a tremendous disparity in the nuclear industry between the pace of the unfolding nuclear renaissance, which is gathering momentum by the day, and the slower pace at which we are educating a new generation of nuclear scientists and engineers. The WNU aims to be instrumental in creating a network of leading institutions of nuclear learning in order to help fill this gap. The emerging worldwide partnership aims to: - Enhance nuclear education amongst its members, - Establish globally accepted standards in academic and professional qualification, and - Elevate the prestige of the nuclear profession. Prior to the establishment of WNU, many leading educational institutions of nuclear learning had already launched cooperation on a regional basis, as follows (country or region/network): United States/NEDHO (Nuclear Engineering Department Head Organization); Canada/UNENE (University Network of Excellence in Nuclear Engineering in Canada); Asia/ANENT (Asian Network for Education in Nuclear Technology); Europe/ENEN (European Nuclear Education Network); Russia/WNU Russian Branch. Thus the WNU can be seen to a certain extent as a 'network of networks', although it should be stressed that many of the current WNU members did not belong to already existing networks. By creating a global network, the WNU avoids the duplication of efforts and limits the total number of staff required. The WNU does not lose sight of the fact, however, that local problems should be solved locally. Ten Working Groups share between them the activities of the

  15. Cationic speciation in nonaqueous media

    International Nuclear Information System (INIS)

    Electronic spectra of solutions of d transition elements in the superacids HF, H2SO4, HSO3F, and CF3SO3H and in chloroaluminate melts indicate that in acidic monaqueous media the elements are present as solvated cations, whereas in basic media the speciation is anionic, the same situation as in aqueous solutions. Further, in very highly acidic media, cations in very low oxidation states are stable (e.g., Ti2+), but these disproportionate on addition of base to the system. In this paper spectra, where available, of U, Np, and Pu in oxidation states III and IV in aqueous media, in protonic superacids, and in chloroaluminates are presented to postulate cationic speciation of these early actinides in highly acidic media

  16. "Shall I compare thee to a summer's day?": intralocution and the teaching of Renaissance poetry in Taiwan

    OpenAIRE

    Yang, Chih-chiao Joseph

    2006-01-01

    This thesis examines the educational role of English literature in Taiwan and proposes a method of reading and teaching English Renaissance poetry for Taiwanese students and teachers. Based upon the idea of integrating literature and language, this thesis suggests a stylistic approach to reading as well as interpreting literary texts. The thesis will argue that the prevalent communicational features of Renaissance poetry will, during the reading process, allow Taiwanese students to explor...

  17. ‘A fare bella’: the visual and material culture of cosmetics in Renaissance Italy (1450-1540)

    OpenAIRE

    Spicer, Jacqueline Nicole

    2015-01-01

    This thesis maps out the roles of cosmetic use in Renaissance Italy from the period c.1450-1540, using books containing cosmetic recipes as the primary source material. Their content, dissemination, and use is explored as a means of creating a new understanding of a practice central to daily life and integral to ongoing arguments about the body. Recent scholarship has seen a rise in interest in books of recipes and secrets in the Renaissance and Early Modern periods, but there ...

  18. Application of surfactant-templated ordered mesoporous material as sorbent in micro-solid phase extraction followed by liquid chromatography-triple quadrupole mass spectrometry for determination of perfluorinated carboxylic acids in aqueous media.

    Science.gov (United States)

    Lashgari, Maryam; Basheer, Chanbasha; Kee Lee, Hian

    2015-08-15

    In the present study, micro-solid phase extraction (µ-SPE) followed by liquid chromatography-triple tandem mass spectrometery (LC-MS/MS) was developed for the determination of perfluorocarboxylic acids (PFCAs) at trace levels in water samples. The µ-SPE device comprised of a porous polypropylene membrane bag containing 5mg sorbent. The membrane bag acted as a clean-up filter and prevented matrix compounds from interfering with the extraction process. Analysis was carried out by LC-MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring. Calcined and non-calcined MCM-41, as silica-ordered mesoporous materials, were used as sorbents in µ-SPE for the extraction of five PFCAs-perfluoropentanoic acid (PFPA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA)-from aqueous media. The performances of these two sorbents were compared with other sorbents such as octadecylsilane (C18) modified silica, HayeSep-A, HayeSep-B, and Porapak-R. It was found that non-calcined MCM-41 showed better extraction performance for the analytes considered. Parameters influencing extraction efficiency, such as desorption time, extraction time, desorption solvent, and salt concentration, were investigated. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Only minor effects on ionization efficiencies were observed. The developed method proved to be convenient and offered good sensitivity and reproducibility. The limits of detection ranged from 0.02 to 0.08ng L(-1), with a relative standard deviations between 1.9 and 10.5. It was successfully applied to the extraction of PFCAs in river and rain water samples. As expected from the ubiquitous nature of PFCAs, contamination at low levels was detected for some analytes in the samples (with the highest concentration recorded for PFOA). Satisfactory relative recoveries ranging

  19. Renaissance bookbindings on Slovene reformation prints from the Slovene National Museum in Ljubljana

    Directory of Open Access Journals (Sweden)

    Sonja Svoljšak

    2004-01-01

    Full Text Available Four of these prints: two Dalmatin’s Bibles, Dalmatin’s Lepe karszhanske molitve and Trubar’s Hishna postilla have leather stiff board decorative renaissance bindings while Bohorič’s Arcticae horulae succisivae has a stiff board vellum binding.A short overview of the European renaissance bookbindnig characteristics and decorative motives development is presented in the first part, followed by the codicological census. The second part of the research consists of decorative tools and motives clasiffication and an individual motive analysis. An overview of the decorative motives on four decorative reformation bindings in the context of the European reformation book decoration styles with special emphasis on the Wittemberg reformation book decoration style is given in the final analysis.

  20. The African Renaissance and its relation to the geosciences: a South African perspective

    Science.gov (United States)

    Mtimkulu, M. N.; Motloung, M.; Graham, I. T.; Eriksson, P. G.; Bumby, A. J.

    2001-08-01

    Implicit in the African Renaissance is the synergy between government, the private sector, the educated minority and the disadvantaged majority. For this concept to work, belief and commitment must arise first from the African individual, whatever his or her potential contribution may be. The geosciences in South Africa provide a currently vibrant example of such cooperation, which has the potential to contribute significantly to the upliftment of the country and its neighbouring states. Based largely on personal interviews with various role players, from the Presidency of South Africa, through ministerial levels, the corporate sector and down to the individual, we present a spectrum of viewpoints and initiatives which are starting to result in practical implementation of the African revival. An end to conflict and xenophobia, the entrenchment of democratic government and corporate expression of the entrepreneurial spirit are essential to provide the framework within which the individual African can become a "Renaissance Man or Woman".

  1. 传统工艺“返老还童”%The Renaissance of Handicrafts

    Institute of Scientific and Technical Information of China (English)

    翟新颖

    2012-01-01

    As a powerhouse of culture, Shandong has rich traditional bhandicraft resources, which inrecent years have received much attention from all walks of life and undergone a momentum renaissance. However, the renaissance of the traditional handicrafts still has a long way to go.%作家老舍写过一个短篇《断魂枪》,里面写镖局变成了客栈,镖师沙子龙深夜独练“五虎断魂枪”。面对现代文明的侵袭,沙子龙“用手指慢慢摸着冰凉的枪身”,“微笑里甩出斩钉截铁的四个字‘不传不传”’。

  2. Consumer Identity Renaissance: The Resurgence of Identity-Inspired Consumption in Retirement

    OpenAIRE

    Hope Jensen Schau; Gilly, Mary C; Mary Wolfinbarger

    2009-01-01

    Using multimethod data, we investigate retirement as a life stage centered on consumption, where cultural scripts are particularly contested and in flux and where we witness an increase in breadth and depth of identity-related consumption, which we term consumer identity renaissance. While prior research on older consumers focuses on corporeal and cognitive decline and its impact on individual decision-making situations, our attention is drawn to the competency and growth potential of those w...

  3. Recent advances in catalytic asymmetric hydrogenation:Renaissance of the monodentate phosphorus ligands

    Institute of Scientific and Technical Information of China (English)

    GUO Hongchao; DING Kuiling; DAI Lixin

    2004-01-01

    The history for the development of chiral phosphorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent advances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced a renaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.

  4. La renaissance de l'histoire de la comptabilité

    OpenAIRE

    Colasse, Bernard

    2010-01-01

    Texte de la conférence d'ouverture des XVèmes journées d'histoire de la comptabilité et du management (Université Paris-Dauphine, 24-25 mars 2010) prononcée par l'auteur : il y évoque la renaissance en France de l'histoire de la comptabilité dans les années 1980 et 1990.

  5. The Ingenium Radiancy. Cosmological Representations and Nature Generative Power during the Renaissance

    OpenAIRE

    Vélez Posada, Andrés

    2015-01-01

    This paper offers an approximation to the notion of ingenium in the context of art and philosophy during the European Renaissance. Given its lexical recurrence, its visual representation and the spectrum of ideas covered by it, the ingenium is a paradigmatic notion that calls the attention of specialists in the history of philosophical concepts and researchers in the field of the cultural history of knowledge. To demonstrate this idea, the article intertwines philosophical commentary, mainly,...

  6. The Not-Forgotten Empire: Images of Persia in English Renaissance Writing

    OpenAIRE

    Grogan, Jane

    2010-01-01

    This essay argues that the image of Persia is a familiar, largely positive and particularly compelling one for English Renaissance readers and writers. It surveys the range of sources of information available, and the kinds of uses to which they were put. Challenging the weight of recent scholarship on the Ottomans which presents them writ large as the representatives of the 'East' for English audiences and readers, I hope to show that the distinctiveness of Persia in the English imagination ...

  7. Play it again, Sam: Die Renaissance der Industriepolitik in der Großen Rezession

    OpenAIRE

    Christian Reiner

    2012-01-01

    Die bereits vor der Krise einsetzende Renaissance der Industriepolitik wurde durch die Krise vollendet. Eine aktive Beeinflussung der Wirtschaftsstruktur ist mittlerweile wieder ein weithin anerkanntes wirtschaftspolitisches Instrument. Dabei spielt die deutsche Entwicklung in der Krise eine wichtige Rolle. Die sinkenden Arbeitslosenquoten in der größten Wirtschaftskrise seit den 1930er-Jahren, die hohen Leistungsbilanzüberschüsse sowie das weiterhin bestehende erstklassige Rating der Staatsf...

  8. Shepherding the Flock: Pope Julius II’s Renaissance Vision of a Unified Italy

    OpenAIRE

    Fishburne, James

    2012-01-01

    Renaissance Italy was a politically fragmented peninsula that was controlled by an array of princes while foreign powers occupied vast territories. Nonetheless, one sixteenth-century figure had a vision of political unity, albeit under ecclesiastical leadership. Pope Julius II, reigning from 1503-1513, was an ambitious theocratic monarch who controlled the Papal States and was the leader of Western Christianity. His primary goals were to expel foreign forces and create a Universal Church with...

  9. Francis Bacon and the "Interpretation of Nature" in the late Renaissance.

    Science.gov (United States)

    Serjeantson, Richard

    2014-12-01

    The "interpretation of nature" (interpretatio naturae) is the leading idea in Francis Bacon's natural philosophy. But by contrast with his ideas about method, induction, or experiment, the significance of the "interpretation of nature" has received very little scholarly attention. This essay tests the originality of Bacon's idea by means of a focused survey of existing forms of Renaissance natural knowledge-Aristotelian and anti-Aristotelian natural philosophy, Galenic and Paracelsian medicine, natural magic, physiognomy, natural history-before turning to consider the much more prominent place of "interpretation" in the fields of Renaissance logic, revealed and natural theology, and law. It finds that Bacon's application of the idea of "interpretation" to nature was highly original, but also that certain important aspects of his conception have analogies in Renaissance civil law. The essay concludes by exploring the implications of these findings for a recent body of scholarship in the history of the sciences that invokes the notion of the "interpretation of nature" to characterize pre-Baconian natural philosophy more generally. PMID:25665379

  10. Flow of Aqueous Humor

    Science.gov (United States)

    ... Facebook Twitter Google Plus Email Print this page Flow of Aqueous Humor Most, but not all, forms ... aqueous humor) produced by the eye's ciliary body flows out freely (follow blue arrow). Aqueous humor flows ...

  11. Media Pedagogy: Media Education, Media Socialisation and Educational Media

    OpenAIRE

    Lars Qvortrup

    2007-01-01

    The aim of this paper is to examine the relationship between education and media. These two concepts can be combined in three ways: one can think of media education, i.e. education in the subject of mass media. One can think of media socialisation, i.e. education within the context of a media society in which pupils and students are experienced media users. Finally, one can think of educational media, i.e. media used for educational purposes.After having specified these three subject areas, t...

  12. Mercury removal from aqueous and organo-aqueous solutions by natural Mexican erionite

    International Nuclear Information System (INIS)

    The sorption of Hg(II) from aqueous and organo aqueous solutions was investigated by Mexican natural erionite. The mercury chemical species (anionic, cationic or neutral) were determined by high voltage electrophoresis, and the mercury chemical species present in the aqueous media were simulated by a program MEDUSA. The mercury sorption process was monitored during 48 hours. The mercury content was determined by neutron activation analysis. Mixtures of benzene/water[Hg(II)], toluene/water[Hg(II)] and ethanol/water[Hg(II)] were chosen as organo-aqueous media. It was found that both the mercury chemical species and the dielectric constant of solvents play an important role in the mercury sorption by erionite. (author)

  13. Die Erfindung und Verabschiedung eines Zeitalters. Zur Renaissance bei Hugo von Hofmannsthal, Rainer Maria Rilke und Heinrich Mann // The Invention of and Departure from an Era. On Renaissance in Hugo von Hofmannsthal, Rainer Maria Rilke and Heinrich Mann

    OpenAIRE

    Brittnacher, Hans Richard

    2012-01-01

    Der Beitrag fragt nach den Gründen für die ’Entdeckung’ der Renaissance in der Historiographie des 19. Jahrhunderts und für die ästhetische Besetzung des Themas zumal in der Dekadenzliteratur. Gerade die Erfahrung der eigenen Krisen, die historisch, ästhetisch oder erotisch unterschiedlich erfahren werden, lässt die Zeitgenossen anfällig werden für den mit der Renaissance assoziierten Kult von Kraft und Größe, eines hemmungslosen Individualismus und einer ruchlosen Amoral. An drei charakteris...

  14. The Renaissance of Nuclear Energy in the Shadow of Climate Change

    Science.gov (United States)

    Conolley, Heather L.

    In the last decade, nuclear energy has experienced a renaissance of interest across the globe. Even in the wake of the Fukushima disaster, numerous countries have reaffirmed their commitment to building nuclear reactors. Why? Why are countries willing to take on the risk of nuclear energy production, given the potential devastation that can result from nuclear catastrophes, the increased risk of nuclear weapons proliferation, and unresolved issues of radioactive waste disposal? What determines a country's nuclear energy policy, and more specifically, is climate change a major driver of the renaissance? This dissertation offers a multi-method approach to answering these questions, with particular emphasis on the relationship between nuclear energy and climate change. A look at the history of nuclear energy worldwide reveals a remarkable consistency of issues, actors and events that have shaped the nuclear debate. Concerns about energy security and the need to meet growing electricity demand have been enduring motivations since the 1950s -- as have clandestine desires for acquiring nuclear weapons capabilities. Unique to the contemporary period are concerns about global warming. Yet despite the popular and widespread assertion that climate change is a driver of the renaissance, the search for evidence produces mixed results. Ultimately, this study uses quantitative statistical methods to determine the factors that influence nuclear energy policy. The results indicate that climate change mitigation is not a primary motivation for most countries to pursue nuclear energy, but mitigation may be a driver for those countries already in the advanced planning and construction phases of nuclear reactors since 2005. Other factors are important as well, including future energy needs, level of development, desalination, export development strategies, and whether or not the country has a strategic rival. Climate change is the global issue of our time. Yet in using nuclear energy

  15. Heather Clark. The Ulster Renaissance - Poetry in Belfast 1962-1972

    Directory of Open Access Journals (Sweden)

    Maryvonne BOISSEAU

    2007-06-01

    Full Text Available The idea of what has been termed an Ulster Renaissance to refer to the surge of new poetry in the North of Ireland in the late 1960s and 1970s together with what is known as the Belfast Group is often dismissed by the poets themselves and serious critics as a mere shorthand and inaccurate way to describe the vitality of that decade. Heather Clark’s study, originally a PhD dissertation, challenges this and argues for the significant impact of Hobsbaum’s group, later Heaney’s group, as well as ...

  16. The outlook for nuclear energy in the United States dark ages, renaissance, or age of enlightenment?

    International Nuclear Information System (INIS)

    According to the World Nuclear Association (WNA), today there are some 439 nuclear power reactors operating in 31 countries (including Taiwan), with a combined capacity of over 370 GWe. These reactors provided about 15% of the world's electricity in 2007. Nuclear energy was responsible for more than 25% of the total electricity supply in 16 countries. In kWh, the US, France, Russia and Korea were the largest producers of nuclear energy in 2008. As of August 2009, some 52 nuclear power units were under construction in 14 countries, and most of these were being built in China (16), Russia (9), India (6), and S. Korea (5). After being suspended in 1985, construction of the Tennessee Valley Authority's (TVA) Watts Bar Unit 2 resumed in 2008, making it the only nuclear unit under construction in the US at this time. In addition to those under construction, many more reactors (100 +) have been proposed and are in various stages of the pre-construction planning and licensing process. As of September 1, 2009, this includes 18 construction and operating license (COL) applications that have been filed with the Nuclear Regulatory Commission (NRC) for 28 new units in the US alone. Furthermore, according to the International Atomic Energy Agency (IAEA) and the WNA, approximately 30 additional countries are exploring the possibility of starting nuclear energy programs as an option for meeting their future electricity needs. In a global sense, this certainly looks like a 'renaissance' to a casual observer or to someone who is inclined to see it that way. However, most of the renaissance is occurring elsewhere, and the US and some other countries are still struggling to launch substantial new nuclear build programs. The renaissance is also a cause of concern to some. The growing number of reactors in a growing number of countries, many with relatively limited nuclear experience, also increases the risk of a safety-related accident or terrorist incident. While we have seen from the

  17. Corps, apparences vestimentaires et identités en France à la Renaissance

    Directory of Open Access Journals (Sweden)

    Isabelle Paresys

    2012-02-01

    Full Text Available Un corps vêtu spécifique émerge à la Renaissance en France et particulièrement à la Cour. Le vêtement impose sa marque sur le corps, accentue le dimorphisme sexuel des apparences, et donne à celles-ci rectitude ou distorsion, transformant le corps en une surface décorative sur laquelle peut s’exprimer la magnificence des souverains et celle de leur cour. Ce corps vêtu résulte de l’influence de modes européennes et de nouvelles normes de civilité qui construisent la présentation de soi. Elles trouvent leur pleine expression à la cour où le corps de mode aristocratique affiche une éloquence distinctive et cosmopolite. Dans le même temps, les identités qu’inculque le vêtement au corps paraissent menacées par les transferts de pratiques vestimentaires entre les sexes, entre les groupes sociaux et entre les nations, entraînant un malaise envers ce brouillage des apparences qui prend une couleur particulière durant les guerres civiles quand se pose de manière sanglante la question des identités et de la conscience nationale.Body, Dress and Identities in Renaissance France. A specific type of clothed body emerged in 16th century France especially at Court. Clothing put its mark on the body, accentuating sexual dimorphism, imposing either Renaissance rectitude or distortions, transforming the body into a decorative surface for displaying magnificence. Its specificity resulted from the influence of various vestimentary and decorative fashions, starting with the new kinds of civility circulating in Renaissance Europe, which fashioned self-presentation. It found its fullest expression on the bodies of cosmopolitan aristocrats seeking a distinctive eloquence for their particular identity. At the same time, the identities which clothes imprinted on their wearer seemed threatened by transfers of vestimentary practices between sexes, sexual groups, and/or nations. The unease created by this mixture of appearances reflects that of

  18. Difference in General Writing Characteristics between Famous Dramatists during English Renaissance

    Institute of Scientific and Technical Information of China (English)

    杨晓丽

    2015-01-01

    <正>The Renaissance is a cultural movement,which started in Italy in the Late Medieval period and later spread to the rest of Europe.It had a great influence on literature,philosophy,art and other aspects of intellectual inquiry.Drama is a performing art and primarily written for theater.Actors and the directors not only use words but also depend on the power of spectacle to bring out the desired effect of the play and to realize the intended goal of the dramatist.The

  19. Analisys Of The Main Character In Oliver Bowden’s Novel Assassin’s Creed Renaissance

    OpenAIRE

    Fadillah, Tengku Danu Rizky

    2013-01-01

    This paper entitled “The Analysis of Main Characters In Oliver Bowden’s Novel Assassin’s Creed Renaissance. This novel tells the story of a boy who did everything possible to defend the dignity of his family who had been in slander and sentenced to death. There are four main characters in the novel “Assassin’s Creed Renaissance” namely: Ezio Auditore da Firenze, Cristina Calfucci, Leonardo da Vinci, and Rodrigo Borgia. Ezio is the son of Giovanni Auditore who is the owner of the largest banks...

  20. NAPLES, 1629: BUREAUCRACY, WAR FINANCE AND THE “RENAISSANCE STATE”

    Directory of Open Access Journals (Sweden)

    Antonio Calabria

    2003-01-01

    Full Text Available This essay examines the financial situation of the Kingdom of Naples in 1629 through an analysis of the state budget for that year. It details the difficult condition of the exchequer in Naples on the cusp of the economic crisis of the seventeenth century and of the all-consuming hostilities of the Thirty Years’ War. It highlights the idiosyncratic link between bureaucracy and warfinance in Naples and shows that strong elements of tradition and innovation were tightly entwined in the workings of the “Renaissance state”.

  1. Introduction to “Marriage and Elite Structure in Renaissance Florence, 1282-1500”

    Directory of Open Access Journals (Sweden)

    John F. Padgett

    2011-12-01

    Full Text Available The following conference paper, written in 1994, is the first draft of an article eventually published in 2010 in Renaissance Quarterly, entitled “Open Elite? Social Mobility, Marriage, and Family in Florence, 1282-1494.” This introduction discusses the methodological justifications for publishing a first draft, written sixteen years before the final, more sophisticated article. By unveiling some steps of the actual process of research, it allows a discussion of the relationships between the two styles of “interpretation” in history and “testing hypotheses” in social science.

  2. The outlook for nuclear energy in the United States dark ages, renaissance, or age of enlightenment?

    Energy Technology Data Exchange (ETDEWEB)

    Brodman, J.

    2009-07-01

    According to the World Nuclear Association (WNA), today there are some 439 nuclear power reactors operating in 31 countries (including Taiwan), with a combined capacity of over 370 GWe. These reactors provided about 15% of the world's electricity in 2007. Nuclear energy was responsible for more than 25% of the total electricity supply in 16 countries. In kWh, the US, France, Russia and Korea were the largest producers of nuclear energy in 2008. As of August 2009, some 52 nuclear power units were under construction in 14 countries, and most of these were being built in China (16), Russia (9), India (6), and S. Korea (5). After being suspended in 1985, construction of the Tennessee Valley Authority's (TVA) Watts Bar Unit 2 resumed in 2008, making it the only nuclear unit under construction in the US at this time. In addition to those under construction, many more reactors (100 +) have been proposed and are in various stages of the pre-construction planning and licensing process. As of September 1, 2009, this includes 18 construction and operating license (COL) applications that have been filed with the Nuclear Regulatory Commission (NRC) for 28 new units in the US alone. Furthermore, according to the International Atomic Energy Agency (IAEA) and the WNA, approximately 30 additional countries are exploring the possibility of starting nuclear energy programs as an option for meeting their future electricity needs. In a global sense, this certainly looks like a 'renaissance' to a casual observer or to someone who is inclined to see it that way. However, most of the renaissance is occurring elsewhere, and the US and some other countries are still struggling to launch substantial new nuclear build programs. The renaissance is also a cause of concern to some. The growing number of reactors in a growing number of countries, many with relatively limited nuclear experience, also increases the risk of a safety-related accident or terrorist incident. While

  3. Evil Media

    OpenAIRE

    Fuller, Matthew; Goffey, Andrew (translated by)

    2012-01-01

    Evil Media develops a philosophy of media power that extends the concept of media beyond its tried and trusted use in the games of meaning, symbolism, and truth. It addresses the gray zones in which media exist as corporate work systems, algorithms and data structures, twenty-first century self-improvement manuals, and pharmaceutical techniques. Evil Media invites the reader to explore and understand the abstract infrastructure of the present day. From search engines to flirting strategies, f...

  4. Media education.

    Science.gov (United States)

    Strasburger, Victor C

    2010-11-01

    The American Academy of Pediatrics recognizes that exposure to mass media (eg, television, movies, video and computer games, the Internet, music lyrics and videos, newspapers, magazines, books, advertising) presents health risks for children and adolescents but can provide benefits as well. Media education has the potential to reduce the harmful effects of media and accentuate the positive effects. By understanding and supporting media education, pediatricians can play an important role in reducing harmful effects of media on children and adolescents. PMID:20876180

  5. Lesson and learn from 'Fukushima Daiichi' 180 day's tweets. Inevitable NPP renaissance of the culture and technology

    International Nuclear Information System (INIS)

    Tweeting for severe reactor accident of Toden-EPCO Fukushima Daiichi due to the Eastern Japan M9 earthquake brought me 'Nuclear Renaissance'. Along to the twitter-time-line of the accident consequences, the spent fuel pool, containment, hydrogen explosion, destroyed core, and contamination have been discussed as Inferno. 'Hairo' and back fitting of existing NPPs have been discussed as Purgatorio. NPP Renaissance through nuclear energy synergetics has been discussed as Paradiso. Through these discussions, the East Asia Rim Community takes the role of the 'KOU(one of the keywords in traditional East Asian game 'GO') for realizing 'Nuclear Renaissance' by the 22 Century, resulting in becoming the keystone of the development to the 'All Asia Community'. (author)

  6. Cultural relations between Hungary and Albania during the period of Humanism and Renaissance

    Directory of Open Access Journals (Sweden)

    Muhamet Mala

    2016-07-01

    Full Text Available Cultural Hungarian-Albanian relations during the Middle Ages are characterized by a relatively poor intensity. Actually, relations between these two countries are more intense in the political field and especially through the partnership between Gjergj Kastrioti Skanderbeg and John Hunyadi. Regarding the origin, the Hungarian culture identity is rather distinct from the Albanian one. Lack of cultural contacts, among others, was conditioned also by the fact that these relations were held under war circumstances and their primary aim was the common defense from Ottoman attacks. Actually, the Albanian medieval culture remained a Mediterranean culture with elements of Byzantine influence in the continental and southern areas. Meanwhile, Hungary belonged to Central Europe, which, even though far away from Mediterranean cultural mainstream, sought to be influenced by this culture, namely by the Renaissance that emanated exactly in the Mediterranean region. It was Matthias Corvinus effort, regarding the cultural influence of the Mediterranean and Renaissance in Hungary but also the fact that Hungary possessed some of the most important towns of the Adriatic coast and particularly Ragusa. This city was the center where cultural relations between Albanian and Hungary started and became intensified in the religious, intellectual and human field.

  7. Renaissance Scientists: Collaboration across disciplines to meet the world's water-related challenges.

    Science.gov (United States)

    Dwelle, M. C.

    2014-12-01

    Water is the source for pressures throughout the world as supplies of freshwater become more scarce and stressed. These pressures can be realized through the lens of water science, policy, geopolitics, food security, and even military conflicts. Combined with a boom in global population, these pressures provide wide-reaching problems that need to be addressed presently and in the future across many disciplines including the sciences, engineering, economics, and policy. These issues lead to a complex system of problems that cannot be addressed without a multidisciplinary approach. As we enter a world where regions of water scarcity become the norm, water scientists and engineers need to be at the table - with experts in other fields - shaping solutions in the areas of policy, disaster response, and management. I will argue that, as early-career scientists, there are exciting new challenges that are open, or will be opening, to us as experts in our respective fields. I will also provide my insights and opinions as to what we can do to position ourselves to impact these issues. These beliefs form the basis of the "Renaissance scientist," taking its name from the polymaths of the Renaissance and Enlightenment. The name suggests that we need to not only leverage our own area expertise, but also be able to effectively learn from and communicate with experts in seemingly diverse fields to meet the world's water-related challenges.

  8. Bioprospecting the African Renaissance: The new value of muthi in South Africa

    Directory of Open Access Journals (Sweden)

    Reihling Hanspeter CW

    2008-03-01

    Full Text Available Abstract This article gives an overview of anthropological research on bioprospecting in general and of available literature related to bioprospecting particularly in South Africa. It points out how new insights on value regimes concerning plant-based medicines may be gained through further research and is meant to contribute to a critical discussion about the ethics of Access and Benefit Sharing (ABS. In South Africa, traditional healers, plant gatherers, petty traders, researchers and private investors are assembled around the issues of standardization and commercialization of knowledge about plants. This coincides with a nation-building project which promotes the revitalization of local knowledge within the so called African Renaissance. A social science analysis of the transformation of so called Traditional Medicine (TM may shed light onto this renaissance by tracing social arenas in which different regimes of value are brought into conflict. When medicinal plants turn into assets in a national and global economy, they seem to be manipulated and transformed in relation to their capacity to promote health, their market value, and their potential to construct new ethics of development. In this context, the translation of socially and culturally situated local knowledge about muthi into global pharmaceuticals creates new forms of agency as well as new power differentials between the different actors involved.

  9. Media Literacy

    OpenAIRE

    Gelu Mihai LEICU; Laura Rita PITARIU

    2015-01-01

    Media are part of our lives today. Our pupils watch TV, play online games, blog, upload videos on YouTube, use Facebook, etc. Messages transmitted by the media flow constantly into our and their minds. Media literacy provides us with a range of information and abilities which help us analyse, evaluate, and even create messages in various modes of the media. Students are encouraged to think critically about the media they consume. Hobbs has found out that media literacy implies: a set of skill...

  10. Imatinib intermediate as a two in one dual channel sensor for the recognition of Cu²⁺ and I⁻ ions in aqueous media and its practical applications.

    Science.gov (United States)

    Patil, Samadhan R; Nandre, Jitendra P; Jadhav, Devising; Bothra, Shilpa; Sahoo, S K; Devi, Manisha; Pradeep, Chullikkattil P; Mahulikar, Pramod P; Patil, Umesh D

    2014-09-21

    An imatinib intermediate, 6-methyl-N-[4-(pyridin-3-yl)pyrimidin-2-yl]benzene-1,3-diaminepyridopyrimidotoluidine (PPT-1), was developed for the colorimetric sensing of Cu(2+) ions in aqueous solution. With Cu(2+), the receptor PPT-1 showed a highly selective naked-eye detectable color change from colorless to red over the seventy other tested cations. The colorimetric sensing ability of PPT-1 was successfully utilized in the preparation of test strips and supported silica for the real samples analysis to detect Cu(2+) ions from 100% aqueous environment. Moreover, the iodide-sensing ability of receptor PPT-1 was explored among the ten examined anions. PMID:25056090

  11. Tang Renaissance

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China’s ancient capital Xi’an, famous for the Terracotta Warriors, is going through a cultural and economic revival Xi’an, the provincial capital of Shaanxi Province in central China, is one of the most important cities in the country’s history. Under the name of Chang’an,

  12. Agricultural Renaissance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An old Chinese proverb says that "poverty gives rise to the desire for change," and this may in part explain why 18 farmers from a rural village in east China’s Anhui Province made the bold decision in 1978 to fix farm output quotas per

  13. Renaissance Science and Literature: Benedetti, Ovid and the Transformations of Phaeton's Myth after Copernicus

    Science.gov (United States)

    Omodeo, Pietro Daniel

    2014-01-01

    This paper aims at showing the close ties between Renaissance literature and science as emerge from the use and the transformation, in a post-Copernican context, of the myth of Phaeton--according to Greek mythology: the boy who tried to conduct the chariot of the Sun and died in this attempt. G.B. Benedetti's analysis and criticism of…

  14. Garin and Paul Oskar Kristeller: Existentialism, Neo-Kantianism and the Post-War Interpretation of Renaissance Humanism

    OpenAIRE

    Hankins, James

    2011-01-01

    Eugenio Garin and Paul Oskar Kristeller were the most important interpreters of Renaissance humanism in the half century following the Second World War. This article explores the differences between their two interpretations from a biographical perspective, making use of their unpublished correspondence. Key passages from their correspondence are published in an appendix.

  15. The environmental education in the Italian Renaissance: the geoethical model of Machiavelli

    Science.gov (United States)

    Liserre, Battista; De Pascale, Francesco

    2016-04-01

    The importance of the environmental and geoethical education is also present in the thought of one of the greatest intellectuals of the Italian Renaissance: the philosopher Niccolò Machiavelli (1469-1527). In the "Discorsi" of Machiavelli, the natural character of the place where a city is built is a determining factor in the overall measure of the need on the character of the citizens; but the barren place, if can keep away the people from idleness, and thereby constitute an essential tool of virtuous civic life, prevents the development of the power which can be fostered only by the fertility of the site. It may give rise own laziness which hinders the development of virtue; and then, according to Machiavelli, laws must be to impose the need to produce good behavior through education. Already in the Renaissance, Machiavelli recognized the importance of establishing a harmonious relationship between man and environment and suggested that the institutions should give a virtuous model of environmental education. The physiognomy of the geographical and natural environment conditions in an essential way the exercise of civil life and the development of virtues. If the Rome's model imposes the primacy of fertile places, it happens, however, that, in his general conception of virtue and of historical dialectic, Machiavelli tended toward ultimately to increased functionality of the desolate places, which make difficult the life, and through the exercise of the need, make men more virtuous, keeping them away from the destructive threat of idleness. This aspect emerges from a different perspective, but convergent in "Asino" of Machiavelli (Chapter V). The link between the natural places and civic life that takes place isn't something absolutely default. Men's work, orders underpinning their collective life, laws that place the compulsion of necessity by the behavior of citizens, change the data of nature. Although the structure of a territory unequally, according to

  16. Transport in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Dickenson, Eric [Univ. of California, Davis, CA (United States)

    1996-05-01

    A novel non-intrusive fluorescence imaging technique is used to study microscopic transport within porous media. The system consists of a column packed with heterogeneous-transparent particles and a refractive index-matched aqueous fluid seeded with fluorescent tracer particles or an organic dye. The flow through the column is illuminated by a planar sheet of laser beam and details of flow and transport through the porous regions can be observed microscopically and qualitative and quantitative transport information can be obtained. Various geometric, flow, and concentration quantities can be determined over a three dimensional volume within the column. The quantities include local and volumetrically averaged porosities, velocity and concentration fields, microscopic and volumetrically averaged dispersive fluxes and the dispersion coefficient. The qualitative and quantitative results will provide a better understanding for modeling of transport in porous media.

  17. From the Flamm-Einstein-Rosen bridge to the modern renaissance of traversable wormholes

    CERN Document Server

    Lobo, Francisco S N

    2016-01-01

    We consider the possibility of multiply-connected spacetimes, ranging from the Flamm-Einstein-Rosen bridge, geons, and the modern renaissance of traversable wormholes. A fundamental property in wormhole physics is the flaring-out condition of the throat, which through the Einstein field equation entails the violation of the null energy condition. In the context of modified theories of gravity, it has also been shown that the normal matter can be imposed to satisfy the energy conditions, and it is the higher order curvature terms, interpreted as a gravitational fluid, that sustain these non-standard wormhole geometries, fundamentally different from their counterparts in general relativity. We explore interesting features of these geometries, in particular, the physical properties and characteristics of these `exotic spacetimes'.

  18. From the Flamm-Einstein-Rosen bridge to the modern renaissance of traversable wormholes

    Science.gov (United States)

    Lobo, Francisco S. N.

    2016-05-01

    We consider the possibility of multiply-connected spacetimes, ranging from the Flamm-Einstein-Rosen bridge, geons, and the modern renaissance of traversable wormholes. A fundamental property in wormhole physics is the flaring-out condition of the throat, which through the Einstein field equation entails the violation of the null energy condition (NEC). In the context of modified theories of gravity, it has also been shown that the normal matter can be imposed to satisfy the energy conditions, and it is the higher order curvature terms, interpreted as a gravitational fluid, that sustain these nonstandard wormhole geometries, fundamentally different from their counterparts in general relativity (GR). We explore interesting features of these geometries, in particular, the physical properties and characteristics of these ‘exotic spacetimes’.

  19. [Female responsibilities: midwives, nurses and mothers in the works of some antique and Renaissance physicians].

    Science.gov (United States)

    Bacalexi, Dina

    2005-01-01

    In his De morborum causis Galen presents the very moment of childbirth, in order to emphasise that the midwife's act of reception is instrumental in preventing malformations of the infant's "humid" limbs; nurses are also responsible for future malformations. The role of the midwife as the physician's assistant with female patients is stressed by Hippocrates and Soranos. The French Renaissance physicians Simon de Vallambert, Jacques and Charles Guillemeau refer to Galen in order to criticise the incompetence of midwives and nurses, as opposed to biological mothers, who have to breast-feed their babies because nurses lack moral integrity. Galen's commentator François Valleriole explains that nurses swaddle girls differently from boys because they aim at artificial (immoral) beauty. Leonhart Fuchs underlines that improper swaddling causes girls to lose their femininity. Thus, medical commentary changes into moralising remarks in order to maintain the moral and social status quo concerning women. PMID:16201319

  20. L’exemplarité de Didon dans les Vies de femmes illustres à la Renaissance1

    OpenAIRE

    Clavier, Tatiana

    2012-01-01

    Les recueils de Vies de femmes illustres, genre littéraire à succès à la Renaissance, utilisent l’exemplarité à des fins didactiques tout autant que polémiques. L’étude de la figure particulière de Didon permet d’envisager les enjeux et modalités de la construction de l’exemplarité féminine. Entre l’amoureuse éplorée de Virgile et l’intransigeante uniuira de Justin, la balance n’est pas égale. Seule Christine de Pizan entreprend de louer l’héroïne virgilienne, tandis que Champier mélange les ...

  1. Erasmus of Rotterdam (1466-1536): renaissance advocate of the public role of medicine.

    Science.gov (United States)

    Albury, W R; Weisz, G M

    2003-08-01

    The great Renaissance scholar Erasmus of Rotterdam was a pioneering advocate of the importance of medicine for social as well as individual welfare. Erasmus' "Oration in praise of the art of medicine" (1518) illustrates his literary approach to this topic. Although the original version of his text did not address the state's role in promoting the health of the populace, Erasmus inserted new material on this topic into the "Oration" for a 1529 edition. This new material and references in some of his other writings from the same period indicate that it was in the 1520s that Erasmus first became a strong advocate of government intervention in public health matters. It is suggested that medical events in Erasmus' own life-his experiences both as a patient and as an observer of diseases-may explain why his interest in public health legislation increased significantly around this time. PMID:12870034

  2. Integration of Hybrid Outdoor and Indoor Surveying. A Case Study in Spanish Renaissance Style Towers

    Directory of Open Access Journals (Sweden)

    J. I. Sánchez

    2011-12-01

    Full Text Available The fusion of different image- and range-based techniques is acknowledged as the best option for threedimensional surveying of objects displaying a complicated geometry at different scales and/or resolutions. A special case deserving still several challenges involves to towers which represent a compendium of constructive elements and, consequently, a large amount of problems related to conservation or maintenance interventions. In this work, we display an extended photogrametric approach which includes elements information systems in Architecture with a special regard to structural analysis and some aspects of materials analysis. We illustrate our approach with several examples regarding a hybrid surveying of architectural Renaissance towers which have been constructed in several agrarian zones of the kingdom of Castilla (Spain along 16th and 17th centuries.

  3. Shakespeare and other English Renaissance authors as characterized by Information Theory complexity quantifiers

    Science.gov (United States)

    Rosso, Osvaldo A.; Craig, Hugh; Moscato, Pablo

    2009-03-01

    We introduce novel Information Theory quantifiers in a computational linguistic study that involves a large corpus of English Renaissance literature. The 185 texts studied (136 plays and 49 poems in total), with first editions that range from 1580 to 1640, form a representative set of its period. Our data set includes 30 texts unquestionably attributed to Shakespeare; in addition we also included A Lover’s Complaint, a poem which generally appears in Shakespeare collected editions but whose authorship is currently in dispute. Our statistical complexity quantifiers combine the power of Jensen-Shannon’s divergence with the entropy variations as computed from a probability distribution function of the observed word use frequencies. Our results show, among other things, that for a given entropy poems display higher complexity than plays, that Shakespeare’s work falls into two distinct clusters in entropy, and that his work is remarkable for its homogeneity and for its closeness to overall means.

  4. Myths of Male Same-Sex Love in the Art of the Italian Renaissance

    Directory of Open Access Journals (Sweden)

    Ann Haughton

    2015-09-01

    Full Text Available Visual culture has much to contribute to an understanding of the history of sexuality. Yet, to date, the depiction of pederasty in the art of the Renaissance has not been covered adequately by dominant theoretical paradigms. Moreover, the interpretive approach of traditional art historical discourse has been both limited and limiting in its timidity toward matters concerning the representation of sexual proclivity between males. This article will address the ways in which Italian Renaissance artistic depictions of some mythological narratives were enmeshed with the period’s attitudes toward sexual and social relationships between men.Particular attention is paid here to the manner in which, under the veneer of a mythological narrative, certain works of art embodied a complex set of messages that encoded issues of masculine behaviour and performance in the context of intergenerational same-sex erotic relationships.  The primary case studies under investigation for these concerns of gender and sexuality in this particular context are Benvenuto Cellini’s marble Apollo and Hyacinth (1545, and Giulio Romano’s drawing of Apollo and Cyparissus (1524. By incorporating pictorial analysis, social history, and gender and sexuality studies, new possibilities will be offered for evaluating these artworks as visual chronicles of particular sexual and cultural mores of the period. Furthermore, this article will consider how visual representation of these mythic narratives of erotic behaviour between males conformed to the culturally defined sexual and social roles relating to the articulation of power that permeated one of the greatest milestones in art history.

  5. Generalized corrosion of nickel base alloys in high temperature aqueous media: a contribution to the comprehension of the mechanisms; Corrosion generalisee des alliages a base nickel en milieu aqueux a haute temperature: apport a la comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti-Sillans, L

    2007-11-15

    In France, nickel base alloys, such as alloy 600 and alloy 690, are the materials constituting steam generators (SG) tubes of pressurized water reactors (PWR). The generalized corrosion resulting from the interaction between these alloys and the PWR primary media leads, on the one hand, to the formation of a thin protective oxide scale ({approx} 10 nm), and on the other hand, to the release of cations in the primary circuit, which entails an increase of the global radioactivity of this circuit. The goal of this work is to supply some new comprehension elements about nickel base alloys corrosion phenomena in PWR primary media, taking up with underlining the effects of metallurgical and physico-chemical parameters on the nature and the growth mechanisms of the protective oxide scale. In this context, the passive film formed during the exposition of alloys 600, 690 and Ni-30Cr, in conditions simulating the PWR primary media, has been analyzed by a set of characterization techniques (SEM, TEM, PEC and MPEC, XPS). The coupling of these methods leads to a fine description, in terms of nature and structure, of the multilayered oxide forming during the exposition of nickel base alloys in primary media. Thus, the protective part of the oxide scale is composed of a continuous layer of iron and nickel mixed chromite, and Cr{sub 2}O{sub 3} nodules dispersed at the alloy / mixed chromite interface. The study of protective scale growth mechanisms by tracers and markers experiments reveals that the formation of the mixed chromite is the consequence of an anionic mechanism, resulting from short circuits like grain boundaries diffusion. Besides, the impact of alloy surface defects has also been studied, underlining a double effect of this parameter, which influences the short circuits diffusion density in oxide and the formation rate of Cr{sub 2}O{sub 3} nodules. The sum of these results leads to suggest a description of the nickel base alloys corrosion mechanisms in PWR primary

  6. Media Flow

    DEFF Research Database (Denmark)

    Kabel, Lars

    2015-01-01

    News and other kinds of journalistic stories, 16-17 hours a day, all year round, on all platforms, also the moderated social media. The key research thesis behind this article is that the continuous and speedy stream of news stories and media content now is becoming the centre of the production...... processes and the value creation in converged multimedia newsrooms. The article identify new methods and discuss editorial challenges in handling media flow....

  7. Media Literacy

    OpenAIRE

    O' Neill, Brian; Hagen, Ingun

    2009-01-01

    Across Europe and beyond, the promotion of media literacy, for children and adults, has acquired an important public urgency. Traditional literacy is seen to be no longer sufficient for participation in today’s society. Citizens need to be media literate, it is claimed, to enable them to cope more effectively with the flood of information in today’s highly mediated societies. As teachers, politicians and policy makers everywhere struggle with this rapid shift in media culture, greater respons...

  8. Mass Media

    Institute of Scientific and Technical Information of China (English)

    叶全荣

    2006-01-01

    @@ Every day,we are all influenced by the mass media.Although some critics of the media claim that these means of communication are used mainly to control our thinking and get us to buy products that we don't need,the media also contribute to keeping people informed.In other words,while dangers do exist,the benefits of the media far outweigh(超过)the disadvantages.Most of the messages brought to viewers,listeners,and readers are designed either to inform or to entertain,and neither of these goals can be considered dangerous or harmful.

  9. Matte Svart Kristiansen & Kate Giles (eds., Dwellings, Identities and Homes. European Housing Culture from the Viking Age to the Renaissance (Hojbjerg: Jutland Archeological Society, 2014

    Directory of Open Access Journals (Sweden)

    Thomas Hoeren

    2016-03-01

    Full Text Available Book review of: Matte Svart Kristiansen & Kate Giles (eds., Dwellings, Identities and Homes. European Housing Culture from the Viking Age to the Renaissance (Hojbjerg: Jutland Archeological Society, 2014

  10. Mixed ligand two dimensional Cd(ii)/Ni(ii) metal organic frameworks containing dicarboxylate and tripodal N-donor ligands: Cd(ii) MOF is an efficient luminescent sensor for detection of picric acid in aqueous media.

    Science.gov (United States)

    Rachuri, Yadagiri; Parmar, Bhavesh; Bisht, Kamal Kumar; Suresh, Eringathodi

    2016-05-01

    Two dimensional metal organic frameworks (MOFs) [Cd(5-BrIP)(TIB)]n () and [Ni2(5-BrIP)2(TIB)2]n (), involving the aromatic polycarboxylate ligand 5-bromo isophthalic acid (H2BrIP), flexible tripodal ligand 1,3,5-tris(imidazol-1-ylmethyl)benzene (TIB) and Cd(ii)/Ni(ii) metal nodes have been synthesized by different methods. These compounds were characterized by various analytical methods, and variable temperature X-ray diffraction data showed thermal stability of both MOFs up to 350 °C. Phase purity as well as water stability of the MOFs were established by powder X-ray diffraction, and the structural diversity of the compounds were investigated by single-crystal X-ray diffraction. Both the MOFs are mixed ligand 2D nets, and the topology of the network can be described as a binodal 3,5-c connected net with 3,5L2 topology having the point symbol {4(2)·6(7)·8}{4(2)·6}. Sensing of picric acid [2,4,6-trinitrophenol, TNP] by luminescence quenching among a large range of nitroanalytes in aqueous phase by the Cd(ii) luminescent MOF (LMOF) were been investigated. Structural studies on 1 : 1 co-crystals () of TIB and TNP were carried out. The selective and sensitive fluorescence quenching response of towards electron-deficient TNP over other nitro analytes in aqueous phase was demonstrated by fluorescence quenching titration. Concomitant occurrence of electron transfer/energy transfer processes and electrostatic interaction favours the selective sensing of TNP. A Cd(ii) LMOF ()-coated paper strip that we developed demonstrated fast and selective response to TNP, by the complete quenching of the blue fluorescence upon excitation of the paper strip at 365 nm radiation in its presence. PMID:27067118

  11. Print media vs internet media

    OpenAIRE

    Koganuramath, M. M.; Angadi, Mallikarjun

    1999-01-01

    The Information Technology has revolutionised the communication media with the emergence of Internet. This paper describes the pace of change in print media to On-line journalism. The process has began with On-line journalism utilising Internet wherein websites are replacing the print media. Most of the On-line newspapers are free, interactive and archival in nature and it provides users to search the information on newspapers through various access points i.e. by contributors, title, and dat...

  12. Avaliação do desempenho de surfactantes para a solubilização de fases líquidas não aquosas em meio aquoso Evaluating surfactant performance as solubilizer of non-aqueous phase liquids within aqueous media

    Directory of Open Access Journals (Sweden)

    Elizabeth Fátima de Souza

    2010-01-01

    Full Text Available The presence of non-aqueous phase liquids (NAPLs in the subsurface is a threat to public health as well as a serious environmental issue. NAPLs may remain adsorbed or form lenses floating on aquifers causing long-term contaminations. Surfactants may increase NAPLs solubility, enhancing the pump-and-treatment performance. Size, shape, hydration and ionization degree of the micelles define the affinity and the space available for the solubilization of a particular contaminating agent. The tests carried out at laboratory scale, taking into account the NAPL to be removed and the medium characteristics were useful to select surfactants and evaluate their efficiency as NAPLs solubilizers.

  13. Mixed Media

    Science.gov (United States)

    Peterson, Erin

    2010-01-01

    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  14. Media darling

    CERN Multimedia

    Chalmers, Matthew

    2008-01-01

    He is the media-friendly face of particle physics, appearing on countless TV and radio shows in the run-up to the opening of CERN's Large Hadron Collider. Matthew Chalmers discovers how Brian Cox finds the time to be both a physicist and a media personality. (2 pages)

  15. Italy as the Cradle of the Renaissance:From the Perspective of Its Partic-ular Reasons

    Institute of Scientific and Technical Information of China (English)

    HUANG Mei

    2015-01-01

    The Renaissance is a period from the 14th to the 17th centuries, considered as a shift from Middle Ages to Modern times of European history. It developed from Middle Ages which laid its political, economical, cultural and social foundation. Owing to the development of capitalist production relations in Europe during the late Middle Ages, bourgeoisie initiated this cultural movement whose essence is humanism as a fight against feudalism.The Renaissance originated in the form of a cultural movement from Italy in the 14th century and swept over the whole Europe. Apart from the common factors contributing to this movement, the peculiar reasons why Italy became the bellwether of this essential cultural movement are as follows:direct inherit of ancient Roman tradi⁃tion, the favorable geographical position, the unparalleled cities with the development of commerce, city republics and secularism.

  16. From nuclear stagnation to renaissance: The challenge of transferring regulatory knowledge

    International Nuclear Information System (INIS)

    Full text: Around 20 years ago there was a de facto nuclear stagnation of the peaceful uses of atomic energy in the West. At the time, governmental institutions for nuclear research and regulation, as well as the nuclear industry, had a nuclear 'intelligentsia' and many well qualified specialists available. Moreover, universities were ready and able to educate the next generation of professionals. The decline of the nuclear industry was therefore damaging both for individuals and the schools educating them. The options were few: for the workers, to restart a working life in other industries or to try to hang on until retirement; for the educational institutions, to abandon researching and teaching nuclear subjects. Now, however, an emerging energy crisis and growing environmental concerns about the burning of fossil fuels are inducing Western politicians to rethink the soundness of the decision to curtail the nuclear power industry. It therefore seems that there will be a nuclear renaissance, but that the qualified personnel to carry this out are no longer available, since in the intervening years they have changed jobs, retired or died. Put simply, the plentiful workforce responsible for last century's nuclear miracle is no longer there. Moreover, a cultural gap exists between the past and present generations, and such a lack of cultural continuity creates a difficult challenge for the traditional inter-generational knowledge transfer that has enabled development in the past. There are many reasons for this situation, and it will be for historians to explain them, but it is obvious that the Chernobyl accident and the public belief that nuclear installations were not safely regulated played a crucial role. At the time, nuclear regulatory authorities were less demanding, and in many countries they simply did not exist. Concepts such as regulatory independence and strengthening and safety culture are generally post-Chernobyl phenomena. Moreover, over the past decades

  17. Social media

    OpenAIRE

    Sova, Ondřej

    2012-01-01

    This thesis deals with social media and is trying to characterize them with focus on their development which led to the creation of social networks. The history of the internet is very short, but its development was giant, and only few people can imagine the world without it. Social media grew in parallel to the internet, so they are its integral part from the beginning. Social media were slowly replacing press, because they gave us a new dimension in the form of immediate feedback. They also...

  18. Community Media: Muting the Democratic Media Discourse?

    NARCIS (Netherlands)

    Carpentier, N.; Lie, R.; Servaes, J.

    2003-01-01

    Focuses on the concept of community media. Components that construct the identity of community media; Multi-theoretical approaches for analysis of community media; Definition of community media based on the concept of alternative media; Link between community media and civil society; Problems faced

  19. From Augmentation Media to Meme Media.

    Science.gov (United States)

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  20. Media violence.

    Science.gov (United States)

    Willis, E; Strasburger, V C

    1998-04-01

    American media are the most violent in the world, and American society is now paying a high price in terms of real life violence. Research has confirmed that mass media violence contributes to aggressive behavior, fear, and desensitization of violence. Television, movies, music videos, computer/video games are pervasive media and represent important influences on children and adolescents. Portraying rewards and punishments and showing the consequences of violence are probably the two most essential contextual factors for viewers as they interpret the meaning of what they are viewing on television. Public health efforts have emphasized public education, media literacy campaign for children and parents, and an increased use of technology to prevent access to certain harmful medial materials. PMID:9568012

  1. Guelphs, Ghibellines and Etruscans: Archaeological Discoveries and Civic Identity in Late Medieval and Early Renaissance Tuscany

    Directory of Open Access Journals (Sweden)

    Lucy Shipley

    2013-04-01

    Full Text Available This paper examines the rediscovery of the ancient Etruscans, in central Italy, during the thirteenth, fourteenth and fifteenth centuries AD. Knowledge about the Etruscans from this earlier period was overshadowed by the interest in Etruscan antiquities promoted by Pope Leo X (1513–1521 and Cosimo I de Medici (1519–1574 during the late Renaissance. I argue that the sixteenth century appropriation of the Etruscan past would not have been possible without the discoveries of earlier generations of Tuscans, and, more particularly, without a reversal in attitudes towards the Etruscan past that began during the late thirteenth century. Prior to this, the Etruscans were perceived negatively, as allied to darkness and paganism. In this paper, I argue that this change in the perception of the Etruscans was closely allied to the particular political situation of the city-state of Florence, and that the origins of Etruscan archaeology can be elucidated in the centre of the maelstrom of war, famine and plague that characterised the fourteenth century in central Italy.

  2. Joining the Nuclear Renaissance with the Engineering Business Unit of AREVA

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, Nathalie; Menguy, Stephane [SGN, AREVA Group, 1 rue des Herons, 78182 Saint-Quentin en Yvelines Cedex (France); Valery, Jean-Francois [AREVA NC, AREVA Group, Tour AREVA, 1 place de la Coupole, 92084 Paris La Defense Cedex (France)

    2008-07-01

    The reality of the nuclear renaissance is no longer a question. All over the world, new nuclear plants are going to be deployed; the whole fuel cycle has to be adjusted to fulfil their needs, the front-end to produce the fuel and the back-end to properly manage radioactive waste. AREVA fuel cycle engineering teams have been involved in the design of a variety of industrial plants covering the entire fuel cycle for 50 years. The consistency of the French nuclear policy has been a major factor to acquire and renew the competencies and workforce of AREVA Engineering Business Unit. Our partnership with our customers, French ones but also Japanese, Americans and from other countries, has led us to develop a comprehensive approach of the services that we can deliver, in order to give them the best answer. SGN teams have been involved in the R and D phases in order to take into account the industrialisation aspects as early as possible, and our work does not end with the delivery of the plants; it includes assistance to the operators to optimise and keep their facilities in line with the changing rules and constraints, which ensures the integration of a wide operational experience feedback and the ability to design flexible facilities. This paper will present through our experience how this global approach has been developed and continuously improved and how we are preparing our teams to be ready to answer to the coming needs. (authors)

  3. Galaxy Properties and UV Escape Fractions During Epoch of Reionization: Results from the Renaissance Simulations

    CERN Document Server

    Xu, Hao; Norman, Michael L; Ahn, Kyungjin; O'Shea, Brian W

    2016-01-01

    Cosmic reionization is thought to be primarily fueled by the first generations of galaxies. We examine their stellar and gaseous properties, focusing on the star formation rates and the escape of ionizing photons, as a function of halo mass, redshift, and environment using the full suite of the {\\it Renaissance Simulations} with an eye to provide better inputs to global reionization simulations. This suite, carried out with the adaptive mesh refinement code Enzo, is unprecedented in terms of their size and physical ingredients. The simulations probe overdense, average, and underdense regions of the universe of several hundred comoving Mpc$^3$, each yielding a sample of over 3,000 halos in the mass range $10^7 - 10^{9.5}~\\Ms$ at their final redshifts of 15, 12.5, and 8, respectively. In the process, we simulate the effects of radiative and supernova feedback from 5,000 to 10,000 metal-free (Population III) stars in each simulation. We find that halos as small as $10^7~\\Ms$ are able to form stars due to metal-l...

  4. Our unacknowledged ancestors: dream theorists of antiquity, the middle ages, and the renaissance.

    Science.gov (United States)

    Rupprecht, C S

    1990-06-01

    Exploring the dream world from a modern, or post-modern, perspective, especially through the lens of contemporary technologies, often leads us as researchers to see ourselves as engaged in a new and revolutionary discourse. In fact, this self-image is a profoundly ahistorical one, because it ignores the contributions of ancient, medieval and Renaissance oneirologists who wrote extensively, albeit in different terms and images of lucidity, prerecognition, day residue, wish fulfillment, incubation, problem solving, REM, obe, and the collective unconscious. There are also analogues in these early accounts to anxiety, recurrent, mirror, telepathic, shared, flying, and death dreams. Dream interpretation through music, analysis of dream as narrative, sophisticated theories about memory and language and symbolization are all part of the tradition. Further, early texts pose many issues in sleep and dream research which are not currently being pursued. We dream workers of the late twentieth century should therefore fortify ourselves with knowledge of the oneiric past as one important way to enhance our dream work in the twenty-first century. PMID:2197652

  5. Continuum mechanics through the ages from the renaissance to the twentieth century : from hydraulics to plasticity

    CERN Document Server

    Maugin, Gérard A

    2016-01-01

    Mixing scientific, historic and socio-economic vision, this unique book complements two previously published volumes on the history of continuum mechanics from this distinguished author. In this volume, Gérard A. Maugin looks at the period from the renaissance to the twentieth century and he includes an appraisal of the ever enduring competition between molecular and continuum modelling views. Chapters trace early works in hydraulics and fluid mechanics not covered in the other volumes and the author investigates experimental approaches, essentially before the introduction of a true concept of stress tensor. The treatment of such topics as the viscoelasticity of solids and plasticity, fracture theory, and the role of geometry as a cornerstone of the field, are all explored. Readers will find a kind of socio-historical appraisal of the seminal contributions by our direct masters in the second half of the twentieth century. The analysis of the teaching and research texts by Duhem, Poincaré and Hilbert on cont...

  6. Babson, Bahnson, the DeWitts and the General Relativity Renaissance

    Science.gov (United States)

    Carter, Hamilton

    2012-03-01

    During the 1950s the efforts of an unlikely group composed of two colorful businessmen, a handful of physicists, and Air Force representatives helped to create a renaissance in general relativity research. Industrialist Agnew Bahson was an air conditioning magnate with connections to leading scientists, and the Air Force. In addition to his contribution to ``respectable'' physics, his life and death are shrouded in a cloak of UFO and anti-gravity conspiracy theories. Business theorist Roger Babson was driven to search for a solution to anti-gravity after first his sister and later his grandson drowned tragically as children. This presentation tells of the globe spanning, harrowing adventure of mountainside crashes, an international love affair, physicists masquerading as secretaries, the founding of Les Houches, the development of the first radar defense system and how Bahnson and Babson became benefactors of mainstream physics, leading to the creation of the Institute of Field Physics at the University of North Carolina Chapel Hill led by Cecile and Bryce DeWitt and ultimately to the groundbreaking research that predicted the Higgs boson.

  7. The Coming Nuclear Renaissance for Next Generation Safeguards Specialists--Maximizing Potential and Minimizing the Risks

    Energy Technology Data Exchange (ETDEWEB)

    Eipeldauer, Mary D [ORNL

    2009-01-01

    This document is intended to provide an overview of the workshop entitled 'The Coming Nuclear Renaissance for the Next Generation Safeguards Experts-Maximizing Benefits While Minimizing Proliferation Risks', conducted at Oak Ridge National Laboratory (ORNL) in partnership with the Y-12 National Security Complex (Y-12) and the Savannah River National Laboratory (SRNL). This document presents workshop objectives; lists the numerous participant universities and individuals, the nuclear nonproliferation lecture topics covered, and the facilities tours taken as part of the workshop; and discusses the university partnership sessions and proposed areas for collaboration between the universities and ORNL for 2009. Appendix A contains the agenda for the workshop; Appendix B lists the workshop attendees and presenters with contact information; Appendix C contains graphics of the evaluation form results and survey areas; and Appendix D summarizes the responses to the workshop evaluation form. The workshop was an opportunity for ORNL, Y-12, and SRNL staff with more than 30 years combined experience in nuclear nonproliferation to provide a comprehensive overview of their expertise for the university professors and their students. The overall goal of the workshop was to emphasize nonproliferation aspects of the nuclear fuel cycle and to identify specific areas where the universities and experts from operations and national laboratories could collaborate.

  8. Production of gold and ruby-red lustres in Gubbio (Umbria, Italy) during the Renaissance period

    Science.gov (United States)

    Padeletti, G.; Fermo, P.

    The aim of this work is to gain a further insight into the knowledge of the production process of lustre-decorated ancient majolicas. Lustre is a sophisticated technique employed in the decoration of majolicas as used in central Italy during the Renaissance period. It consists of a beautiful iridescent gold or ruby-red thin metallic film, containing silver, copper and other substances and obtained in a reducing atmosphere on a previously glazed ceramic. Nowadays, it is not possible to replicate the outstanding results obtained by the ancient ceramicists, since the original recipes were lost. It is quite interesting to study lustre-production technology by means of analytical techniques now employed for advanced research on materials (XRD, ETAAS, ICP-OES, TEM-EDX-SAED and UV-Vis). In this work, we have focussed our attention on ceramic fragments decorated with both gold and ruby-red lustres, which were difficult to obtain due to complex reduction conditions required and which were a prerogative of Gubbio production. The two lustre colours differ in their chemical composition as well in their nanostructure. The presence of bismuth was disclosed and it was ascertained to be a distinctive feature of the Italian production.

  9. United Kingdom from past leadership to the renaissance of nuclear industry

    International Nuclear Information System (INIS)

    United-Kingdom has developed a long tradition of know-how in the domain of nuclear energy since 1956 when the first power reactor entered into service at Calder Hall site. From 1956 till now 45 reactors have been successively connected to the grid. All the sectors of nuclear industry were developed: uranium conversion, enrichment, fuel fabrication, MOX fabrication, spent fuels reprocessing and radioactive waste management. Now British nuclear industry is slowly getting out of a 20 year long period of lethargy due mainly to the lost competition with the oil and gas from the North sea fields. Since 2008 and because the North sea resources are waning, U.K. has become again an oil importer. The new energy policy of the government is to favor renewable energies and to support at least the renewal of the today's reactors. 19 reactors are operating but most are old: 14 reactors will have to be stopped by 2018 unless service life extensions are allowed. The French EDF company who purchased British-Energy in 2009 has announced the construction of 4 EPR by 2025. The renaissance of the nuclear industry in U.K. is all the easier as the past was glorious. (A.C.)

  10. Joining the Nuclear Renaissance with the Engineering Business Unit of AREVA

    International Nuclear Information System (INIS)

    The reality of the nuclear renaissance is no longer a question. All over the world, new nuclear plants are going to be deployed; the whole fuel cycle has to be adjusted to fulfil their needs, the front-end to produce the fuel and the back-end to properly manage radioactive waste. AREVA fuel cycle engineering teams have been involved in the design of a variety of industrial plants covering the entire fuel cycle for 50 years. The consistency of the French nuclear policy has been a major factor to acquire and renew the competencies and workforce of AREVA Engineering Business Unit. Our partnership with our customers, French ones but also Japanese, Americans and from other countries, has led us to develop a comprehensive approach of the services that we can deliver, in order to give them the best answer. SGN teams have been involved in the R and D phases in order to take into account the industrialisation aspects as early as possible, and our work does not end with the delivery of the plants; it includes assistance to the operators to optimise and keep their facilities in line with the changing rules and constraints, which ensures the integration of a wide operational experience feedback and the ability to design flexible facilities. This paper will present through our experience how this global approach has been developed and continuously improved and how we are preparing our teams to be ready to answer to the coming needs. (authors)

  11. A Nuclear Renaissance: The Role of Nuclear Power in Mitigating Climate Change

    Science.gov (United States)

    Winslow, Anne

    2011-06-01

    The U. N. Framework Convention on Climate Change calls for the stabilization of greenhouse gas (GHG) emissions at double the preindustrial atmospheric carbon dioxide concentration to avoid dangerous anthropogenic interference with the climate system. To achieve this goal, carbon emissions in 2050 must not exceed their current level, despite predictions of a dramatic increase in global electricity demand. The need to reduce GHG emissions and simultaneously provide for additional electricity demand has led to a renewed interest in the expansion of alternatives to fossil fuels—particularly renewable energy and nuclear power. As renewable energy sources are often constrained by the intermittency of natural energy forms, scale-ability concerns, cost and environmental barriers, many governments and even prominent environmentalist turn to nuclear energy as a source of clean, reliable base-load electricity. Described by some as a "nuclear renaissance", this trend of embracing nuclear power as a tool to mitigate climate change will dramatically influence the feasibility of emerging nuclear programs around the world.

  12. Late Pop III Star Formation During the Epoch of Reionization: Results from the Renaissance Simulations

    CERN Document Server

    Xu, Hao; O'Shea, Brian W; Wise, John H

    2016-01-01

    We present results on the formation of Pop III stars at redshift 7.6 from the Renaissance Simulations, a suite of extremely high-resolution and physics-rich radiation transport hydrodynamics cosmological adaptive-mesh refinement simulations of high redshift galaxy formation performed on the Blue Waters supercomputer. In a survey volume of about 220 comoving Mpc$^3$, we found 14 Pop III galaxies with recent star formation. The surprisingly late formation of Pop III stars is possible due to two factors: (i) the metal enrichment process is local and slow, leaving plenty of pristine gas to exist in the vast volume; and (ii) strong Lyman-Werner radiation from vigorous metal-enriched star formation in early galaxies suppresses Pop III formation in ("not so") small primordial halos with mass less than $\\sim$ 3 $\\times$ 10$^7$ M$_\\odot$. We quantify the properties of these Pop III galaxies and their Pop III star formation environments. We look for analogues to the recently discovered luminous Ly $\\alpha$ emitter CR7 ...

  13. The nuclear renaissance and AREVA's reactor designs for the 21st century. EPR and SWR-1000

    International Nuclear Information System (INIS)

    Hydro and nuclear energy are the most environmentally benign way of producing electricity on a large scale. Nuclear generated electricity releases 38 times fewer greenhouse gases than coal, 27 times fewer than oil and 15 times fewer than natural gas [9]. On a global scale nuclear power annually saves about 10% of the global CO2 emission. European nuclear power plants save amount of CO2 emissions corresponding with the annual emission of CO2 from all European passenger cars [16]. Also, that is approximately twice the total estimated quantity to be avoided in Europe under the Kyoto Protocol during the period 2008-2012. In respect to main drivers - such as concerns of the global warming effect, population growth, and future energy supply shortfall, low operating costs, reduced dependence on imported gas - it is clear that 30 new nuclear reactors currently being constructed in 11 countries and another 35 and more planed during next 10 years confirm the nuclear renaissance. Participation in the construction of 100 reactors out of 443 worldwide operated in January 2006 and supplying fuel to 148 of them AREVA helps meet the 21st century's greatest challenges: making energy available to all, protecting the planet, and acting responsibly towards future generations. With EPR and SWR-1000, AREVA NP has developed advanced design concepts of Generation III+ nuclear reactors which fully meet the most stringent requirements in terms of nuclear safety, operational reliability and economic performance. (author)

  14. Social Media

    OpenAIRE

    Weller, Katrin; Meckel, Martin Sebastian; Stahl, Matthias

    2013-01-01

    Anlässlich der 10. Wissenschaftlichen Tagung „Soziale Medien“ am 27. und 28. Juni 2013 im Statistischen Bundesamt in Wiesbaden und in Fortsetzung des 2010 erschienenen Recherche Spezial Web 2.0 – Alle machen mit! werden in dieser Ausgabe in sechs Kapiteln Nachweise zu Veröffentlichungen und Forschungsprojekte der letzten drei Jahre zusammengestellt, die sich mit der Rolle von Social Media in verschiedenen Nutzungskontexten befassen. Social-Media-Dienste sind mittlerweile fester Bestandtei...

  15. Determinação das propriedades catalíticas em meio aquoso e orgânico da lipase de Candida rugosa imobilizada em celulignina quimicamente modificada por carbonildiimidazol Assessment of catalytic properties in aqueous and organic media of lipase from Candida rugosa immobilized on wood cellulignin activated with carbonyldiimidazole

    Directory of Open Access Journals (Sweden)

    Fabrício M. Gomes

    2006-07-01

    Full Text Available Microbial lipase from Candida rugosa was immobilized by covalent binding on wood cellulignin (Eucaliptus grandis chemically modified with carbonyldiimidazole. The immobilized system was fully evaluated in aqueous (olive oil hydrolysis and organic (ester synthesis media. A comparative study between free and immobilized lipase was carried out in terms of pH, temperature and thermal stability. A higher pH value (8.0 was found optimal for the immobilized lipase. The optimal reaction temperature shifted from 37 °C for the free lipase to 45 °C for the immobilized lipase. The pattern of heat stability indicated that the immobilization process tends to stabilize the enzyme. Kinetics tests at 37 °C following the hydrolysis of olive oil obeyed the Michaelis-Menten rate equation. Values for Km = 924.9 mM and Vmax = 198.3 U/mg were lower than for free lipase, suggesting that the affinity towards the substrate changed and the activity of the immobilized lipase decreased during the course of immobilization. The immobilized derivative was also tested in the ester synthesis from several alcohols and carboxylic acids.

  16. Medieval and Renaissance anatomists: the printing and unauthorized copying of illustrations, and the dissemination of ideas.

    Science.gov (United States)

    Lanska, Douglas J; Lanska, John Robert

    2013-01-01

    The vanguard that began to question Galenic anatomical dogma originated in northern Italy in the latter half of the thirteenth century, and not coincidentally this was where human dissection was introduced, which in turn eventually fostered the origins of realistic anatomical illustration in the late fifteenth century. With the advent of the printing press and moveable type at this time, printed books began to supersede hand-copied medieval manuscripts, and labor-intensive techniques were soon developed to integrate text and illustrations on the printed page. The same technology was used to pirate the illustrations of prior authors with varying fidelity. Specific medieval and Renaissance anatomical illustrations can often be traced from their inceptions through different stages of development to the final printed images, and then through subsequent pirated versions in various abridgements or other compendia. The most important milestone in the development of anatomy and anatomical illustration was the publication in 1543 by Andreas Vesalii of De humani corporis fabrica (On the Fabric of the Human Body), commonly referred to simply as the Fabrica. With this work, Vesalii succeeded in coordinating a publication production team (author, artists, block cutters, publisher, and typesetters) to achieve an unprecedented integration of scientific discourse, medical illustration, and typography. However, despite Vesalii's valiant efforts to prevent unauthorized duplication, the illustrations from the Fabrica were extensively plagiarized. Although Vesalii found such piracy frustrating and annoying, the long-term effect was to make Vesalii's ideas known to a wider readership and to help solidify his own revolutionary contributions to anatomy. PMID:24041276

  17. Radiological protection system in the era of nuclear renaissance expectation for development of radiological protection system

    International Nuclear Information System (INIS)

    The current radiological protection system, which was established mainly by the ICRP and UNSCEAR, has contributed to the prevention of potential radiological health hazards, and has been a fundamental concept during the development of nuclear energy. Through a detailed discussion regarding the new ICRP recommendations, the world nuclear industry has reached a consensus that the current radiological protection system keeps its integrity in principle although it involves some remaining issues, such as the disposal of radioactive waste. In order to maximize the advantages of nuclear energy while keeping the integrity of radiological protection system, it is essential to address the characteristics of radiation, which is specific to nuclear energy, so that nuclear energy can coexist with other energy sources. The three basic principles of radiological protection (i.e., justification, optimization and dose limits), which were completed in the 1990 recommendations of ICRP, should be retained as the basic concepts for the future radiological protection system in order to maintain the continuity and consistency of the radiological protection system. The radiological protection system can be furthermore developed only by combining the above three principles with best practices extracted from utilities' field experience. The significant reduction of radiation exposures received by members of the public and radiation workers in the field has resulted from the efforts by the world utilities to achieve the optimization. In order to correctly apply the theory to the work practices, it is essential to see how the theory is practically used in the field. Such a process should be also emphasized in the revision work of the IAEA Basic Safety Standards (BSS), which is currently under progress. Integrating the theory in the work practices is the key to the true development of nuclear renaissance, which could lead to the establishment of the nuclear safety regime. (author)

  18. Media Training

    CERN Document Server

    CERN. Geneva

    2009-01-01

    With the LHC starting up soon, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. The training is open for everybody. Make sure you arrive early enough to get a seat - there are only 200 seats in the Globe. The session will also be webcast: http://webcast.cern.ch/

  19. Streaming Media

    Science.gov (United States)

    Pulley, John

    2009-01-01

    At a time when the evolutionary pace of new media resembles the real-time mutation of certain microorganisms, the age-old question of how best to connect with constituents can seem impossibly complex--even for an elite institution plugged into the motherboard of Silicon Valley. Identifying the most effective vehicle for reaching a particular…

  20. Media democracy

    OpenAIRE

    Pels, D.

    2008-01-01

    The present article compendiously presents the interlinked and abruptly developing processes of media democracy and political matters’ personalization. The writer expressly opts for these processes which can radically rejuvenate communication and trust among citizens and politicians and therefore reinforce, up to a certain extend, modern democracy’s function itself.