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 New in this Edition: Four previously unpublished chapters comprising a new section on interfacial propertie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. 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…

  3. Investigation of aqueous stability of taxol in different release media.

    Science.gov (United States)

    Amini-Fazl, Mohammad Sadegh; Mobedi, Hamid; Barzin, Jalal

    2014-04-01

    In the present study, the aqueous stability of taxol in different aqueous media and immiscible aqueous/organic systems at 37 °C was investigated. The aqueous media included phosphate buffered saline (PBS) and PBS containing 10% methanol, 10% ethanol, 10% hydroxypropyl β-cyclodextrin (HP-βCD), 1% sodium citrate and 1% Tween 80. The immiscible systems consisted of PBS/octanol, PBS/dichloromethane, PBS/chloroform and PBS/ethyl acetate. The concentrations of taxol and related derivatives in each of the media were determined through the high-performance liquid chromatography assay. Results showed that hydrolysis and epimerization were two major types of degradation for taxol in the aqueous media starting from the initial hours of contact (6 hours). Addition of Tween 80 to PBS moderately increased the aqueous stability of taxol. As well, using PBS containing 10% HP-βCD inhibited the taxol hydrolysis, while epimerization still in process. In the case of immiscible systems, except for PBS/ethyl acetate system, no evidences of taxol hydrolysis were observed. Meanwhile, epimerization of taxol in PBS/dichloromethane and PBS/chloroform systems underwent due to the ability of C-Cl bonds to form hydrogen bonding with the hydroxyl group of C7 of taxol.

  4. Medical Renaissance.

    Science.gov (United States)

    Toledo-Pereyra, Luis H

    2015-06-01

    The Medical Renaissance started as the regular Renaissance did in the early 1400s and ended in the late 1600s. During this time great medical personalities and scholar humanists made unique advances to medicine and surgery. Linacre, Erasmus, Leonicello and Sylvius will be considered first, because they fit the early classic Renaissance period. Andreas Vesalius and Ambroise Paré followed thereafter, making outstanding anatomical contributions with the publication of the "Human Factory" (1543) by Vesalius, and describing unique surgical developments with the publication of the "The Apologie and Treatise of Ambroise Paré." At the end of the Renaissance and beginning of the New Science, William Harvey, noted British medical doctor and cardiovascular researcher, discovered the general circulation. He published his findings in "The Motu Cordis" in 1628 (Figure 1). The Medical Renaissance, in summary, included a great number of accomplished physicians and surgeons who made especial contributions to human anatomy; Vesalius assembled detailed anatomical information; Paré advanced surgical techniques; and Harvey, a medical genius, detailed the circulatory anatomy and physiology.

  5. 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.

  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. 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

  8. 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

  9. 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...

  10. 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.

  11. 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

    2016-09-01

    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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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...

  3. 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....

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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...

  16. 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

  17. Mechanochemical Dispersion of Nanodiamond Aggregates in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    Xiangyang XU; Yongwei ZHU; Baichun WANG; Zhiming YU; Shengzhong XIE

    2005-01-01

    A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this paper is a purified product of nanometer-sized diamond synthesized by explosive detonation. As obvious aggregation and sediment were observed when the sample was added into deionized water, it is crucial to conduct deaggregation and dispersion investigations. Amid a series of mechanical treatments, I.e. Grinding, stirring, ultrasonic and classification, some reagents are introduced to modify the newly created surface during aggregates comminution. For the co-effects of mechanical forces and surfactants, the mean size of particles was reduced and a stable system containing ND with narrow size distribution was prepared. Mechanism of surface reaction and modification are discussed, while AFM, Zetasizer3000HS, XRD, XPS and FTIR are utilized for the analysis. The functional chemical structure of ND particle surface and surface electrical property changed during the modification processes, and the dispersion character and stability of suspension can consequently be improved.

  18. 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

  19. 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,

  20. 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.

  1. Small Peptides Catalyzed Direct Aldol Reactions of Aldehydes with Hydroxyacetone with Regiocontrol in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    TANG,Zhuo; YANG,Zhi-Hua; CUN,Lin-Feng; GONG,Liu-Zhu; MI,Ai-Qiao; JIANG,Yao-Zhong

    2004-01-01

    @@ Very recently, we[1] found that L-proline amides and dipeptides acted as efficient catalysts for the asymmetric direct aldol reaction. We report here that L-proline-based peptides 1~5 can catalyze the aldol reactions of hydroxyacetone with aldehydes 6 in aqueous media, to give 1,4-diols (7), the disfavored products with either aldolase or L-proline. Both peptides 3 and 4 give good results.

  2. 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...

  3. 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.

  4. 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.

  5. Reductive Cyclodimerization of Arylidenecyanoacetates Promoted by Sm/InCl3 ·4H2O System in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    Hua Yue WU; Jin Chang DING; Le Ping FANG; Jing GAO

    2004-01-01

    Promoted by active indium produced in situ by Sm/InCl3 · 4H2O system, arylidenecyano- acetates undergo reductive cyclodimerization to afford cyclopentamine derivatives with high stereoselectivity under mild conditions in aqueous media.

  6. 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

  7. Fundamental investigation of the transport properties of superacids in aqueous and non-aqueous media

    Science.gov (United States)

    Suarez, Sophia

    In the quest to develop more efficient energy providers one of the main focus of research has been on the improvement of ion transport. In lithium battery research this has led to the incorporation of various lithium salts, ceramics and plasticizers into the poly(ethylene)oxide (PEO) matrix, the polymer most used In Proton Conduction Membrane (PCM) fuel cell research this has led to the development of new membranes, which are designed with to replicate Nafion's ((c)DuPont) proton transport but also improve upon its deficiency of transporting intact fuel molecules and its dependence upon the presence of solvating water molecules. To better understand the process of ion transport, NMR was used to investigate dynamic properties such as D (self-diffusion coefficient) and T1 (spin-lattice relaxation time) of various proton and lithium ion-conducting systems. Ionic conductivity and viscosity measurements were also performed. The systems studied includes aqueous superacid solutions (trifluoromethanesulfonic (TFSA), para-toluenesulfonic (PTSA) and bis(trifluoromethanesulfonyl)imide (TFSI)); nano-porous (NP-) PCM's incorporating various ceramics and 3M fuel/2M H2SO4 solutions; and P(EO)20LiBETI (LiN(SO 2CF2CF3)2 composite incorporating SiO 2 ceramic nano particles. The objective of the study of the superacid solutions was to determine the effect of concentration on the transport. It was found that beyond the ionic conductivity maximum, fluctuations in both D and T1 supports the existence of local ordering in the ionic network, caused by the reduced solvent dielectric coefficient and increasing viscosity. Of the three superacids TFSA was the most conductive and most affected by reduced solvent concentration. For the P(EO)20LiBETI composite the aim was to determine the effect of the ceramic on the ion transport of the composite in a solvent free environment. Results show that the ceramic causes only modest increase in the lithium transport below 90°C. The objective in the

  8. Antioxidant activity of propyl gallate in aqueous and lipid media: a theoretical study.

    Science.gov (United States)

    Medina, Manuel E; Iuga, Cristina; Alvarez-Idaboy, Juan Raúl

    2013-08-21

    In this work, we have carried out a quantum chemistry and computational kinetics study on the reactivity of propyl gallate towards ˙OOH, ˙OOCH3 and ˙OOCHCH2 radicals, in aqueous and lipid media. We have considered three reaction mechanisms: hydrogen transfer (HT), radical adduct formation (RAF) and single electron transfer (SET). Rate constants and relative branching ratios for the different paths contributing to the overall reaction, at 298.15 K, are reported. Our results show that propyl gallate reacts mainly through the HT mechanism, independently of the solvent or the peroxyl radical, contrary to other phenols such as catechols and guayacols previously studied, which react mainly via the SET mechanism. In aqueous media at physiological pH, the calculated rate constants towards the ˙OOH, ˙OOCH3 and ˙OOCHCH2 radicals are 4.56 × 10(8), 1.59 × 10(6) and 4.05 × 10(8) M(-1) s(-1), while in lipid media the rate constants are 2.94 × 10(4), 7.73 × 10(3) and 9.94 × 10(5) M(-1) s(-1). Thus, a propyl gallate molecule acts as a very efficient peroxyl radical scavenger, both in aqueous and lipid media. Since the gallate moiety is a part of other naturally occurring polyphenols such as aflavine gallates and epigallocatechin gallates, the results of this study could be extrapolated to these compounds. Even if these compounds have other antioxidant structures or enhancers, the activity of the gallate moiety could be considered as a lower limit to their antioxidant activity.

  9. 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.

  10. 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.

  11. Extraction of Palladium (Ⅱ) with p-Methylphenylalkylsulfide from Aqueous Chloride Media

    Institute of Scientific and Technical Information of China (English)

    杨立; 章正熙; 刘旭辉; 郭亚莉; 二井晋; 竹内宽

    2005-01-01

    p-Methylphenylalkylsulfide of various alkyl chain length as extractant were synthesized and the extraction of palladium was examined in terms of equilibrium and kinetics. Distribution ratio of Pd was independent of alkyl chain length. For aqueous chloride media, there was a significant difference in distribution ratios for the solution of NaC1 and HC1. The results of loading test and the slope analysis suggest that the extractant and Pd (Ⅱ) form 2:1 complex. Furthermore, the extraction rate based on the volume of aqueous phase was obtained in a stirred vessel, and the rate equation was presented. Unfortunately, it was difficult to construct surfactant liquid membrane system by use of the present extractant.

  12. 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.

  13. 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.

  14. 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.

  15. Arene-ruthenium(II) complexes with hydrophilic P-donor ligands: versatile catalysts in aqueous media.

    Science.gov (United States)

    Crochet, Pascale; Cadierno, Victorio

    2014-09-01

    In the last few years there has been increasing interest in the use of water as a reaction medium for catalysis, and therefore in designing water-soluble transition-metal catalysts. Half-sandwich (η(6)-arene)-ruthenium(ii) complexes are a versatile and well-known family of ruthenium compounds that exhibit a rich catalytic and coordination chemistry. This Perspective article focuses on the catalytic applications in aqueous media of (η(6)-arene)-ruthenium(ii) complexes containing water-soluble phosphines, and related hydrophilic P-donor ligands.

  16. F. M. Dostoevsky - Russian Renaissance - Renaissance Human Myth

    Directory of Open Access Journals (Sweden)

    Fedorov A. A.

    2014-01-01

    Full Text Available The aesthetic and spiritual problems of a heritage of F. Dostoevsky in connection with the perception of his works in Russian culture of beginning of XXth century are considered in the article. N. Berdjaev’s estimation of value of Dostoevsky’s works for Russian Renaissance, when was active discussions the problems of the humanism and further development of the literature and culture, is given in the work. The author has paid attention to Dostoevsky’s activity in search of new opportunities of the literature for the direct image of a human ideal. The remarkable examples of such works were found by the writer in art of the European Renaissance. The opinion that humanism of Renaissance was formed by special type of the self-made man of art and spirit on the basis of the Renaissance myth of person is supported in the article. The author established a connection with humanistic ideas and aesthetic searches of Dostoevsky, Renaissance and Russian Renaissance of beginning of XXth century through the interpretation of a category “the Renaissance myth of man”. In Russian culture Dostoevsky can be estimated as the type of the artist corresponding late European Renaissance Typological aspects of a human myth in F. Dostoevsky’s prose can explain fixed attention to his works in beginning of XXth century. Constant and deep interest for a person and spiritual life ensured the high degree and important features of influence of his works on formation of views of Russian Renaissance on art, art creativity and understanding of the world and the person in terms of tragical humanism. As a result, Dostoevsky’s creative heritage with his humanistic myth of the Renaissance type became the important part of art and Russian spiritual culture of beginning of XXth century.

  17. Renaissance Learning Equating Study. Report

    Science.gov (United States)

    Sewell, Julie; Sainsbury, Marian; Pyle, Katie; Keogh, Nikki; Styles, Ben

    2007-01-01

    An equating study was carried out in autumn 2006 by the National Foundation for Educational Research (NFER) on behalf of Renaissance Learning, to provide validation evidence for the use of the Renaissance Star Reading and Star Mathematics tests in English schools. The study investigated the correlation between the Star tests and established tests.…

  18. 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.

  19. Comparison of homogeneous and heterogeneous catalysts for glucose-to-fructose isomerization in aqueous media.

    Science.gov (United States)

    Choudhary, Vinit; Pinar, Ana B; Lobo, Raul F; Vlachos, Dionisios G; Sandler, Stanley I

    2013-12-01

    Herein, the first comparison of the mechanisms of glucose-to-fructose isomerization in aqueous media enabled by homogeneous (CrCl3 and AlCl3 ) and heterogeneous catalysts (Sn-beta) by using isotopic-labeling studies is reported. A pronounced kinetic isotope effect (KIE) was observed if the deuterium label was at the C2 position, thus suggesting that a hydrogen shift from the C2 to C1 positions was the rate-limiting step with the three catalysts. (13) C and (1) H NMR spectroscopic investigations confirmed that an intra-hydride-transfer reaction pathway was the predominant reaction channel for all three catalysts in aqueous media. Furthermore, the deuterium atom in the labeled glucose could be mapped onto hydroxymethylfurfural and formic acid through reactions that followed the isomerization step in the presence of Brønsted acids. In all three catalysts, the active site appeared to be a bifunctional Lewis-acidic/Brønsted-basic site, based on a speciation model and first-principles calculations. For the first time, a mechanistic similarities between the homogeneous and heterogeneous catalysis of aldose-to-ketose isomerization is established and it is suggested that learning from homogeneous catalysis could assist in the development of improved heterogeneous catalysts.

  20. Anodic Voltammetry of Thioacetamide and its Amperometric Determination in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Daniela Dascălu

    2008-08-01

    Full Text Available TAA is a harmful, presumptive pollutant in tap waters and waste waters. Several alternatives have been tested as new possibilities for the anodic determination of TAA in aqueous solutions, simulated waste waters and tap water. The electrochemical behaviour of thioacetamide (TAA was investigated at a boron-doped diamond (BDD electrode both in unbuffered 0.1 M Na2SO4 and buffered solutions as supporting electrolytes. The anodic oxidation of TAA showed well-defined limiting currents or current peaks and a good linearity of the amperometric signal vs. concentration plots. The analytical parameters of sensitivity, RSD and LOD, obtained under various experimental conditions, suggest the suitability of the BDD electrode for electroanalytical purposes. Low fouling effects, good reproducibility and stability, as well as the sharpness of the amperometric signals in both unbuffered/ buffered acidic or neutral media, highly superior to those obtained using a glassy carbon (GC electrode, recommend the unmodified BDD electrode as a promising potential amperometric sensor for environmental applications, regarding the direct anodic determination of TAA in aqueous media.

  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

    2016-08-12

    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

  2. Calix[4]arene based dipodal receptor nanohybrids for selective determination of chloride ions in aqueous media.

    Science.gov (United States)

    Kaur, Harpreet; Singh, Jasminder; Chopra, Shweta; Kaur, Navneet

    2016-01-01

    A chemical sensor based on p-tert butyl calix[4]arene has been synthesized and characterized using an assortment of spectroscopic techniques such as (1)H NMR, (13)C NMR, and elemental analysis. For sensor application, organic nanoparticles (N1) of 1 have been primed by implementing re-precipitation technique, which were further employed for preparing organic-inorganic hybrid (H1) by decorating N1 with gold nanoparticles. Both N1 and H1 were characterized using UV-visible, fluorescence, and DLS studies. Photo-physical changes due to anion binding with H1 were scrutinized using UV-visible absorption spectrometer and found it to promptly and selectively recognize Cl(-) ions in aqueous media. Thus, H1 can be effectively used for recognition of Cl(-) ions in aqueous media over a wide pH range, in samples of real time importance with a detection limit of 2.84×10(-9) M with a linear detection range up to 50 μM.

  3. 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.

  4. 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)

  5. 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

  6. Oxytetracycline recovery from aqueous media using computationally designed molecularly imprinted polymers.

    Science.gov (United States)

    Rodríguez-Dorado, Rosalía; Carro, Antonia M; Chianella, Iva; Karim, Kal; Concheiro, Angel; Lorenzo, Rosa A; Piletsky, Sergey; Alvarez-Lorenzo, Carmen

    2016-09-01

    Polymers for recovery/removal of the antimicrobial agent oxytetracycline (OTC) from aqueous media were developed with use of computational design and molecular imprinting. 2-Hydroxyethyl methacrylate, 2-acrylamide-2-methylpropane sulfonic acid (AMPS), and mixtures of the two were chosen according to their predicted affinity for OTC and evaluated as functional monomers in molecularly imprinted polymers and nonimprinted polymers. Two levels of AMPS were tested. After bulk polymerization, the polymers were crushed into particles (200-1000 μm). Pressurized liquid extraction was implemented for template removal with a low amount of methanol (less than 20 mL in each extraction) and a few extractions (12-18 for each polymer) in a short period (20 min per extraction). Particle size distribution, microporous structure, and capacity to rebind OTC from aqueous media were evaluated. Adsorption isotherms obtained from OTC solutions (30-110 mg L(-1)) revealed that the polymers prepared with AMPS had the highest affinity for OTC. The uptake capacity depended on the ionic strength as follows: purified water > saline solution (0.9 % NaCl) > seawater (3.5 % NaCl). Polymer particles containing AMPS as a functional monomer showed a remarkable ability to clean water contaminated with OTC. The usefulness of the stationary phase developed for molecularly imprinted solid-phase extraction was also demonstrated. Graphical Abstract Selection of functional monomers by molecular modeling renders polymer networks suitable for removal of pollutants from contaminated aqueous environments, under either dynamic or static conditions. PMID:27488280

  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. Integrated Love Wave Device Dedicated to Biomolecular Interactions Measurements in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Sylvain Ballandras

    2007-09-01

    Full Text Available Mass-sensitive electro-acoustic devices such as surface acoustic wave (SAWmicro-balances, capable to operate with aqueous media are particularly favorable for thedevelopment of biosensors. Their dimensions and physical properties offer a large potentialin biological fluid investigations, especially for measuring physical phenomenon (massdeposition, adsorption, pressure.... In this work, we propose a specific gratingconfiguration to lower the influence of viscosity of fluids which reduces the signal dynamicsof the surface wave transducers. A dedicated liquid cell also has been developed to isolatethe electro-active part of the device. The fabrication of the cell is achieved using theSU-8TMphoto-resist, allowing for manufacturing thick structures preventing any contact between thetested liquids and the transducers. Furthermore, the sensing area has been optimized tooptimize the sensor gravimetric sensitivity. The operation of the sensor is illustrated bydetecting bovine serum albumin (BSA adsorption in the sensing area.

  11. 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.

  12. 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.

  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. 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

  15. Development of a correlation for aqueous-vapor phase mass transfer in porous media

    Science.gov (United States)

    Szatkowski, Andrew; Imhoff, Paul T.; Miller, Cass T.

    1995-03-01

    In many situations vapor-phase extraction procedures (e.g., soil venting, air sparging, and bioventing) may be suitable methods for remediating porous media contaminated by volatile organic compounds. This has led to increased study of operative processes in these systems, including aqueous-vapor phase mass transfer. Past work has shown the importance of the flow regime on this process, but a quantitative estimate of mass-transfer coefficients is lacking, especially for systems not confounded by uncertainties involving interfacial area between the phases. An experimental investigation was conducted to isolate the resistance to aqueous-vapor phase mass transfer at the phase boundary, using an ideal porous medium system. Mass-transfer coefficients were measured for toluene for a wide range of Reynolds numbers. An empirical model was fit to the data in dimensionless form. The mass-transfer model was coupled with an available interfacial area model, yielding a dimensionless expression for the mass-transfer rate coefficient. This expression was used to compare results from this work to three other experimental studies reported in the literature. These comparisons showed that for experiments where infiltrating water flowed uniformly within the porous medium, the predicted mass-transfer coefficients were within a factor of 5 of the measured coefficients. Mass transfer was significantly slower than the rate predicted, using the results from this work, in experiments where infiltrating water flowed nonuniformly.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. β-Cyclodextrin as a Metal-anionic Porphyrin Complexation Accelerator in Aqueous Media.

    Science.gov (United States)

    Ohtomo, Takao; Yokoyama, Aya; Konno, Mitsuyuki; Ohno, Osamu; Igarashi, Shukuro; Takagai, Yoshitaka

    2016-01-01

    The rate of the complexation reaction between anionic porphyrins and 11 metal ions was found to be accelerated by the presence of β-cyclodextrin (β-CD) in aqueous media at room temperature without the need for additional heating or sonication. The porphyrin complexation reaction with metal ions under aqueous conditions can be difficult due to the strong hydration energy between the metal ions and water. In this study, the specific role of β-CD as an accelerator was determined and found to enhance the typically slow reaction of the porphyrin with metal ions. A significant acceleration effect was exhibited when the model anionic porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphine-tetrasulfonic acid, and Pb(II) ions were combined in the presence of β-CD. Other than for Hg ion, the addition of β-CD decreased the metalation reaction time from 30 to 2 min. The order in the degree of acceleration was Pb > Zn, Cd > Cu > Fe, Pd > Sn > Ag, Co, Mn. Using Pb(II) as the model ion, it was determined that the complexation rate constant was enhanced by a factor of 2.4, while the dissociation rate constant was diminished by a factor of 135 in the presence of added β-CD relative to that in its absence. Overall, the complex was much more stable (formation equilibrium constant 324-fold greater in the β-CD medium. The formation of a ternary complex (cf. bicapped complex; (β-CD)2-porphyrin-metal ion) was demonstrated through the use of nuclear magnetic-resonance spectroscopy and mass spectrometry. This acceleration effect is expected to be applicable systems in which porphyrin ligands are employed for determining of metal ions in chemical analysis and separation science.

  1. 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.

  2. β-Cyclodextrin as a Metal-anionic Porphyrin Complexation Accelerator in Aqueous Media.

    Science.gov (United States)

    Ohtomo, Takao; Yokoyama, Aya; Konno, Mitsuyuki; Ohno, Osamu; Igarashi, Shukuro; Takagai, Yoshitaka

    2016-01-01

    The rate of the complexation reaction between anionic porphyrins and 11 metal ions was found to be accelerated by the presence of β-cyclodextrin (β-CD) in aqueous media at room temperature without the need for additional heating or sonication. The porphyrin complexation reaction with metal ions under aqueous conditions can be difficult due to the strong hydration energy between the metal ions and water. In this study, the specific role of β-CD as an accelerator was determined and found to enhance the typically slow reaction of the porphyrin with metal ions. A significant acceleration effect was exhibited when the model anionic porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphine-tetrasulfonic acid, and Pb(II) ions were combined in the presence of β-CD. Other than for Hg ion, the addition of β-CD decreased the metalation reaction time from 30 to 2 min. The order in the degree of acceleration was Pb > Zn, Cd > Cu > Fe, Pd > Sn > Ag, Co, Mn. Using Pb(II) as the model ion, it was determined that the complexation rate constant was enhanced by a factor of 2.4, while the dissociation rate constant was diminished by a factor of 135 in the presence of added β-CD relative to that in its absence. Overall, the complex was much more stable (formation equilibrium constant 324-fold greater in the β-CD medium. The formation of a ternary complex (cf. bicapped complex; (β-CD)2-porphyrin-metal ion) was demonstrated through the use of nuclear magnetic-resonance spectroscopy and mass spectrometry. This acceleration effect is expected to be applicable systems in which porphyrin ligands are employed for determining of metal ions in chemical analysis and separation science. PMID:27302582

  3. Electron transfer between excited states of some sulfonated phtha-locyanines and tyrosine as well as trptophan in homogeneous aqueous solution and aqueous micellar media

    Institute of Scientific and Technical Information of China (English)

    张先付; 许慧君; 沈涛

    1995-01-01

    Rate constants for electron transfer between excited states of several tetrasulfonated phthalocyanines (MTSPC, M = H2, Zn, ClAl, ClGa) and tyrosine or trptophan have been measured in homogeneous aqueous and aqueous micellar media. Cationic micelles formed by surfactant cetyl trimethyl ammonium chloride (CTAC) promote the electron transfer reaction, whereas neutral micelles formed by Triton X-100 depress this process. The calculated free energy change shows that phthalocyanines act as electron donors in the electron transfer reaction of its excited singlet states with tyrosine or trptophan (Type Is), whereas they act as electron acceptors in the reaction of its excited triplet states with tyrosine or trptophan (type IT). The two different electron transfer processes involving singlet and triplet of sensitizer respectively compete with each other and form different intermediates which may induce the formation of different products. Factors that govern the importance of Type Is in the whole reaction includ

  4. 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.

  5. 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...

  6. Ultrasonic-enhanced Stereoselective Debromination of vic-Dibromides to Alkenes with Metallic Zinc Powder in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    LI Pin-hua; RAO Wan-ping; WANG Min; WANG Lei

    2004-01-01

    Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vicdibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo- 1-phenylethane > 1,2-dibromo-1,2-dialkylethane.

  7. 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.

  8. The Extension of Colloid Chemistry from Aqueous to Non-Aqueous Media with Application to Nanofluid Research

    Science.gov (United States)

    Clary, Dan

    Cyclodextrins are cyclic molecules composed of glucose units. The inner cavity of cyclodextrins is noted for its ability to form stable inclusion complexes with a wide variety of guests. A cyclodextrin-glucose host-guest complex was prepared and utilized as both a salt reductant and a particle stabilizer in the generation of aqueous metal colloids including Ag, Au, Pd, and Pt. The resulting colloids demonstrated remarkable stability---3 years and running, in some cases---and have been evaluated for thermal conductivity. Evaluation of the reaction products when the complex is used to reduce Pd 2+ demonstrated a unique comproportionation reaction in which the guest undergoes a two electron oxidation to produce a Pd atom. The resulting atom reduces a neighboring Pd2+ ion to yield two Pd + ions. The monovalent species, in contrast to Pd2+, can then oxidize the host to form atoms which rapidly aggregate to yield particles. Highly stable, crystalline copper(II) oxide particles were prepared which can be isolated as a powder and redispursed in low dielectric media such as hydrocarbons or chloroform. Mass concentrations of up to 20% (1.65 M) were achieved in octane, dodecane, and eicosane and remained stable for at least ten days at room temperature as observed by visible spectroscopy. Quasi-spherical particle shape was observed with the largest fraction possessing a diameter of 9 nm and 90% of the population existing within the range of 5 to 15 nm. The colloidal systems were characterized using FAA, XRD, TEM, UV-Vis, DSC, and a simple device inspired by Newton's Law of cooling which was employed to measure cooling/heating rates. Thermodynamic measurements of sodium oleate-stabilized CuO particles suspended in dodecane and eicosane reveal a decrease in Cp, DeltaH fus , and cooling/heating rates of the resulting colloid with large increases in particle mass concentration. Irradiation with 350 nm photons of anhydrous, air-free octane or toluene solutions of copper(II) oleate

  9. 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

  10. Does excited-state proton-transfer reaction contribute to the emission behaviour of 4-aminophthalimide in aqueous media?

    Science.gov (United States)

    Khara, Dinesh Chandra; Banerjee, Sanghamitra; Samanta, Anunay

    2014-06-23

    4-Aminophthalimide (AP) is an extensively used molecule both for fundamental studies and applications primarily due to its highly solvent-sensitive fluorescence properties. The fluorescence spectrum of AP in aqueous media was recently shown to be dependent on the excitation wavelength. A time-dependent blue shift of its emission spectrum is also reported. On the basis of these findings, the excited-state solvent-mediated proton-transfer reaction of the molecule, which was proposed once but discarded at a later stage, is reintroduced. We report on the fluorescence behaviour of AP and its imide-H protected derivative, N-BuAP, to prove that a solvent-assisted excited-state keto-enol transformation does not contribute to the steady-state and time-resolved emission behaviour of AP in aqueous media. Our results also reveal that the fluorescence of AP in aqueous media arises from two distinct hydrogen-bonded species. The deuterium isotope effect on the fluorescence quantum yield and lifetime of AP, which was thought to be a reflection of the excited-state proton-transfer reaction in the system, is explained by considering the difference in the influence of H(2)O and D(2)O on the nonradiative rates and ground-state exchange of the proton with the solvent.

  11. 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.

  12. 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

  13. 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...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  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. 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

  20. 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

  1. 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

  2. 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.

  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. Transformations of polyols to organic acids and hydrogen in aqueous alkaline media

    NARCIS (Netherlands)

    Haasterecht, van T.; Deelen, van T.W.; Jong, de K.P.; Bitter, J.H.

    2014-01-01

    In this paper we show that carbon nanofiber supported copper and nickel nanoparticles can selectively transform ethylene glycol and glycerol into value added oxygenates (organic acids) under anaerobic aqueous conditions. During aqueous phase oxidation Cu based catalysts showed a nearly quantitative

  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. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. The Kinetic Aspects of the Interaction of Nitrite Ions with Sulfanilic Acid and 1-Naphthylamine in Aqueous and Micellar Media

    Science.gov (United States)

    Korneeva, O. I.; Chernova, R. K.; Doronin, S. Yu.

    2008-04-01

    The kinetics of the reaction of nitrite ions with sulfanilic acid and 1-naphthylamine in aqueous and micellar (sodium dodecyl sulfate) media was studied step-by-step. The diazotization of sulfanilic acid with the nitrite ion was found to occur virtually instantaneously. Anionic surfactant micelles did not influence the rate of this reaction. The calculated effective rate constants and activation energies of the azo coupling reaction between synthesized sulfophenyldiazonium and 1-naphthylamine showed that the passage from water into the micellar medium decelerated the reaction. It was found that sodium dodecyl sulfate micelles played the role of a reagent separator.

  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. Olefin Metathesis in Homogeneous Aqueous Media Catalyzed by Conventional Ruthenium Catalysts

    Science.gov (United States)

    Binder, Joseph B.; Blank, Jacqueline J.; Raines, Ronald T.

    2008-01-01

    Olefin metathesis in aqueous solvents is sought for applications in green chemistry and with the hydrophilic substrates of chemical biology, such as proteins and polysaccharides. Most demonstrations of metathesis in water, however, utilize exotic complexes. We have examined the performance of conventional catalysts in homogeneous water–organic mixtures, finding that the second-generation Hoveyda–Grubbs catalyst has extraordinary efficiency in aqueous dimethoxyethane and aqueous acetone. High (71–95%) conversions are achieved for ring-closing and cross metathesis of a variety of substrates in these solvent systems. PMID:17949009

  14. Corrosion-erosion resistance of Zn-Al co-cementation coatings on carbon steels in aqueous media

    Institute of Scientific and Technical Information of China (English)

    李德志; 何业东; 王德仁; 张召恩; 齐慧滨; 高唯

    2002-01-01

    A novel Zn-Al co-cementation coating was obtained by a pack cementation method. This coating possesses a two-layered structure. The outer layer is mainly composed of Fe2Al5 and FeAl intermetallics with a small amount of Zn, and the inner layer consists of Zn, Fe and a small amount of Al. The corrosion-erosion resistance of Zn-Al co-cementation coatings on carbon steel was studied by a rotary corrosion method in various NaCl and H2S containing solutions and relevant SiO2 containing media. The experimental results are compared with those of carbon steels and the sherardizing and aluminizing coatings, showing that the Zn-Al co-cementation coatings have excellent corrosion-erosion resistance in various aqueous media.

  15. 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.

  16. 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.

  17. 78 FR 16715 - Renaissance Capital Greenwich Funds, et al.; Notice of Application

    Science.gov (United States)

    2013-03-18

    ... COMMISSION Renaissance Capital Greenwich Funds, et al.; Notice of Application March 11, 2013. AGENCY... companies as the series to acquire Shares. Applicants: Renaissance Capital Greenwich Funds (``Trust''), Renaissance Capital LLC (``Adviser''), and Renaissance Capital Investments, Inc. (``Renaissance...

  18. 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

  19. 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.

  20. 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

  1. Impact of polymers on the crystallization and phase transition kinetics of amorphous nifedipine during dissolution in aqueous media.

    Science.gov (United States)

    Raina, Shweta A; Alonzo, David E; Zhang, Geoff G Z; Gao, Yi; Taylor, Lynne S

    2014-10-01

    The commercial and clinical success of amorphous solid dispersions (ASD) in overcoming the low bioavailability of poorly soluble molecules has generated momentum among pharmaceutical scientists to advance the fundamental understanding of these complex systems. A major limitation of these formulations stems from the propensity of amorphous solids to crystallize upon exposure to aqueous media. This study was specifically focused on developing analytical techniques to evaluate the impact of polymers on the crystallization behavior during dissolution, which is critical in designing effective amorphous formulations. In the study, the crystallization and polymorphic conversions of a model compound, nifedipine, were explored in the absence and presence of polyvinylpyrrolidone (PVP), hydroxypropylmethyl cellulose (HPMC), and HPMC-acetate succinate (HPMC-AS). A combination of analytical approaches including Raman spectroscopy, polarized light microscopy, and chemometric techniques such as multivariate curve resolution (MCR) were used to evaluate the kinetics of crystallization and polymorphic transitions as well as to identify the primary route of crystallization, i.e., whether crystallization took place in the dissolving solid matrix or from the supersaturated solutions generated during dissolution. Pure amorphous nifedipine, when exposed to aqueous media, was found to crystallize rapidly from the amorphous matrix, even when polymers were present in the dissolution medium. Matrix crystallization was avoided when amorphous solid dispersions were prepared, however, crystallization from the solution phase was rapid. MCR was found to be an excellent data processing technique to deconvolute the complex phase transition behavior of nifedipine.

  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. The renaissance of developmental biology.

    Science.gov (United States)

    St Johnston, Daniel

    2015-05-01

    Since its heyday in the 1980s and 90s, the field of developmental biology has gone into decline; in part because it has been eclipsed by the rise of genomics and stem cell biology, and in part because it has seemed less pertinent in an era with so much focus on translational impact. In this essay, I argue that recent progress in genome-wide analyses and stem cell research, coupled with technological advances in imaging and genome editing, have created the conditions for the renaissance of a new wave of developmental biology with greater translational relevance.

  4. 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.

  5. 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

  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. 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.

  9. 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 ...

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. A facile approach for cupric ion detection in aqueous media using polyethyleneimine/PMMA core-shell fluorescent nanoparticles

    Science.gov (United States)

    Chen, Jian; Zeng, Fang; Wu, Shuizhu; Su, Junhua; Zhao, Jianqing; Tong, Zhen

    2009-09-01

    A facile approach was developed to produce a dye-doped core-shell nanoparticle chemosensor for detecting Cu2+ in aqueous media. The core-shell nanoparticle sensor was prepared by a one-step emulsifier-free polymerization, followed by the doping of the fluorescent dye Nile red (9-diethylamino- 5H-benzo[alpha] phenoxazine-5-one, NR) into the particles. For the nanoparticles, the hydrophilic polyethyleneimine (PEI) chain segments serve as the shell and the hydrophobic polymethyl methacrylate (PMMA) constitutes the core of the nanoparticles. The non-toxic and biocompatible PEI chain segments on the nanoparticle surface exhibit a high affinity for Cu2+ ions in aqueous media, and the quenching of the NR fluorescence is observed upon binding of Cu2+ ions. This makes the core-shell nanoparticle system a water-dispersible chemosensor for Cu2+ ion detection. The quenching of fluorescence arises through intraparticle energy transfer (FRET) from the dye in the hydrophobic PMMA core to the Cu2+/PEI complexes on the nanoparticle surface. The energy transfer efficiency for PEI/PMMA particles with different diameters was determined, and it is found that the smaller nanoparticle sample exhibits higher quenching efficiency, and the limit for Cu2+ detection is 1 µM for a nanoparticle sample with a diameter of ~30 nm. The response of the fluorescent nanoparticle towards different metal ions was investigated and the nanoparticle chemosensor displays high selectivity and antidisturbance for the Cu2+ ion among the metal ions examined (Na+, K+, Mg2+, Ca2+, Zn2+, Hg2+, Mn2+, Fe2+, Ni2+, Co2+ and Pb2+). This emulsifier-free, biocompatible and sensitive fluorescent nanoparticle sensor may find applications in cupric ion detection in the biological and environmental areas.

  15. DEVELOPMENT OF PROTOTYPE TITANATE ION EXCHANGE LOADED MEMBRANES FOR STRONTIUM, CESIUM AND ACTINIDE DECONTAMINATION FROM AQUEOUS MEDIA

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L; Keisha Martin, K; David Hobbs, D

    2008-05-30

    We have successfully incorporated high surface area particles of titanate ion exchange materials (monosodium titanate and crystalline silicotitanate) with acceptable particle size distribution into porous and inert support membrane fibrils consisting of polytetrafluoroethylene (Teflon{reg_sign}), polyethylene and cellulose materials. The resulting membrane sheets, under laboratory conditions, were used to evaluate the removal of surrogate radioactive materials for cesium-137 and strontium-90 from high caustic nuclear waste simulants. These membrane supports met the nominal requirement for nonchemical interaction with the embedded ion exchange materials and were porous enough to allow sufficient liquid flow. Some of this 47-mm size stamped out prototype titanium impregnated ion exchange membrane discs was found to remove more than 96% of dissolved cesium-133 and strontium-88 from a caustic nuclear waste salt simulants. Since in traditional ion exchange based column technology monosodium titanate (MST) is known to have great affinity for the sorbing of other actinides like plutonium, neptunium and even uranium, we expect that the MST-based membranes developed here, although not directly evaluated for uptake of these three actinides because of costs associated with working with actinides which do not have 'true' experimental surrogates, would also show significant affinity for these actinides in aqueous media. It was also observed that crystalline silicotitanate impregnated polytetrafluoroethylene or polyethylene membranes became less selective and sorbed both cesium and strontium from the caustic aqueous salt simulants.

  16. 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

  17. 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)

  18. Synthesis of β -aminoesters and α -selenoesters via Active Metal Bismuth Produced by Sm/BiCl3 System in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Active metal bismuth is produced in situ via Sm/BiCl3 system in aqueous media. Promoted by this active species, β-aminoesters and α-selenoesters are synthesized via reaction of α-bromoesters with 1-(a -aminoalkyl ) benzotriazole and diselenides in moderate to good yields.

  19. 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.

  20. 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

  1. 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.

  2. Nano-Aluminum Powder Mediated Allylation of Carbonyl Compounds in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    YUAN Shi-Zhen; LIU Jin

    2008-01-01

    A new and effective Barbier-Grignard allylation of aldehydes or ketones has been carried out with nano-aluminum powder in aqueous 0.1 mol·L-1 NH4Cl (aq.) under an atmosphere of nitrogen. Aromatic carbonyl compounds gave homoallylic alcohols in good yields. The effectiveness of reaction was strongly influenced by the steric environment surrounding the carbonyl group. Aliphatic carbonyl compounds proceeded in low yields. The dominant stereoisomer was an erythro-isomer when an ortho-hydroxyl carbonyl compound was reacted under such a reaction condition.

  3. 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

  4. 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)

  5. Synthesis of Silver Nanoparticles Dispersed in Various Aqueous Media Using Laser Ablation

    Directory of Open Access Journals (Sweden)

    M. Tajdidzadeh

    2014-01-01

    Full Text Available The particle size, morphology, and stability of Ag-NPs were investigated in the present study. A Q-Switched Nd: YAG pulsed laser (λ = 532 nm, 360 mJ/pulse was used for ablation of a pure Ag plate for 30 min to prepare Ag-NPs in the organic compound such as ethylene glycol (EG and biopolymer such as chitosan. The media (EG, chitosan permitted the making of NPs with well dispersed and average size of Ag-NPs in EG is about 22 nm and in chitosan is about 10 nm in spherical form. Particle size, morphology, and stability of NPs were compared with distilled water as a reference. The stability of the samples was studied by measuring UV-visible absorption spectra of samples after one month. The result indicated that the formation efficiency of NPs in chitosan was higher than other media and NPs in chitosan solution were more stable than other media during one month storage. This method for synthesis of silver NPs could be as a green method due to its environmentally friendly nature.

  6. Evidence for organic synthesis in high temperature aqueous media - facts and prognosis

    Science.gov (United States)

    Simoneit, Bernd R. T.

    1995-01-01

    Hydrothermal systems are common along the active tectonic areas of the earth. Potential sites being studied for organic matter alteration and possible organic synthesis are spreading ridges, off-axis systems, back-arc activity, hot spots, volcanism, and subduction. Organic matter alteration, primarily reductive and generally from immature organic detritus, occurs in these high temperature and rapid fluid flow hydrothermal regimes. Hot circulating water (temperature range - warm to greater than 400 C) is responsible for these molecular alterations, expulsion and migration. Compounds that are obviously synthesized are minor components because they are generally masked by the pyrolysis products formed from contemporary natural organic precursors. The reactivity of organic compounds in hot water (200-350 C) has been studied in autoclaves, and supercritical water as a medium for chemistry has also been evaluated. This high temperature aqueous organic chemistry and the strong reducing conditions of the natural systems suggest this as an important route to produce organic compounds on the primitive earth. Thus a better understanding of the potential syntheses of organic compounds in hydrothermal systems will require investigations of the chemistry of condensation, autocatalysis, catalysis and hydrolysis reactions in aqueous mineral buffered systems over a range of temperatures from warm to greater than 400 C.

  7. 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.

  8. 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.

  9. 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;

    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...

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. Reusable fluorescent photocrosslinked polymeric sensor for determining lead ions in aqueous media

    Science.gov (United States)

    Çubuk, Soner; Taşci, Neşe; Kahraman, Memet Vezir; Bayramoğlu, Gülay; Yetimoğlu, Ece Kök

    2016-04-01

    In this study, 1-vinylimidazole units bearing photocured films were prepared as fluorescent sensors towards Pb2 + in aqueous solutions. The influence of experimental parameters such as pH, time and foreign ion concentrations were investigated. Sensor response was linear over a concentration range of 4.83 × 10- 8 to 4.83 × 10- 7 mol L- 1. The sensor was highly sensitive with a detection limit as low as 1.87 × 10- 8 mol L- 1, and having a selectivity of over four thousand fold. The response time of the sensor was found to be 5 min. When stored in a desiccator at room temperature the sensor showed good stability after a 5 month period. The fluorescence sensors were successful in the determination of Pb2 + in water samples as well as in the determination of the quantitative amount of lead and the results were satisfying. Compared with previously reported literature, the prepared new sensor is highly sensitive and selective.

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sepulveda-Guzman, S. [Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, UANL Km. 10 de la nueva carretera al Aeropuerto Internacional de Monterrey, PIIT Monterrey, Apodaca NL (Mexico); Facultad de Ingenieria Mecanica y Electrica de la UANL, Ciudad Universitaria San Nicolas de los Garza, Nuevo Leon C.P. 66451 (Mexico)], E-mail: ssepulveda@mail.uanl.mx; Reeja-Jayan, B. [Texas Materials Institute, University of Texas at Austin, 1 University Station C0803 (United States); Rosa, E. de la [Centro de Investigaciones en Optica, A.C. Loma del Bosque 115 Col. Lomas del Campestre, Leon Gto. C.P. 37150 (Mexico); Torres-Castro, A.; Gonzalez-Gonzalez, V. [Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia, UANL Km. 10 de la nueva carretera al Aeropuerto Internacional de Monterrey, PIIT Monterrey, Apodaca NL (Mexico); Facultad de Ingenieria Mecanica y Electrica de la UANL, Ciudad Universitaria San Nicolas de los Garza, Nuevo Leon C.P. 66451 (Mexico); Jose-Yacaman, M. [Physics and Astronomy Department, University of Texas at San Antonio, 1604 Campus San Antonio, TX 78249 (United States)

    2009-05-15

    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){sub 2} and absorbed carbon species on the ZnO surface. In addition, the photoluminescence characterization showed that on UV excitation ({lambda} = 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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 interfacial region at the onset of polymerization is proposed. The results presented here could have implications for other substrates that present surface charges and for the assumption that the kinetics of Cu-mediated SI-CRP are analogous to those conducted in solution.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. The Influence of the Anionic Counter-Ion on the Activity of Ammonium Substituted Hoveyda-Type Olefin Metathesis Catalysts in Aqueous Media

    Science.gov (United States)

    Gułajski, Łukasz; Grela, Karol

    Polar olefin metathesis catalysts, bearing an ammonium group are presented. The electron withdrawing ammonium group not only activates the catalysts electronically, but at the same time makes the catalysts more hydrophilic. Catalysts can be therefore efficiently used not only in traditional media, such as methylene chloride and toluene, but also in technical-grade alcohols, alcohol— water mixtures and in neat water. Finally, in this overview the influence of the anionic counter-ion on the activity of ammonium substituted Hoveyda-type olefin metathesis catalysts in aqueous media is presented.

  15. Renaissance architecture for Ground Data Systems

    Science.gov (United States)

    Perkins, Dorothy C.; Zeigenfuss, Lawrence B.

    1994-01-01

    The Mission Operations and Data Systems Directorate (MO&DSD) has embarked on a new approach for developing and operating Ground Data Systems (GDS) for flight mission support. This approach is driven by the goals of minimizing cost and maximizing customer satisfaction. Achievement of these goals is realized through the use of a standard set of capabilities which can be modified to meet specific user needs. This approach, which is called the Renaissance architecture, stresses the engineering of integrated systems, based upon workstation/local area network (LAN)/fileserver technology and reusable hardware and software components called 'building blocks.' These building blocks are integrated with mission specific capabilities to build the GDS for each individual mission. The building block approach is key to the reduction of development costs and schedules. Also, the Renaissance approach allows the integration of GDS functions that were previously provided via separate multi-mission facilities. With the Renaissance architecture, the GDS can be developed by the MO&DSD or all, or part, of the GDS can be operated by the user at their facility. Flexibility in operation configuration allows both selection of a cost-effective operations approach and the capability for customizing operations to user needs. Thus the focus of the MO&DSD is shifted from operating systems that we have built to building systems and, optionally, operations as separate services. Renaissance is actually a continuous process. Both the building blocks and the system architecture will evolve as user needs and technology change. Providing GDS on a per user basis enables this continuous refinement of the development process and product and allows the MO&DSD to remain a customer-focused organization. This paper will present the activities and results of the MO&DSD initial efforts toward the establishment of the Renaissance approach for the development of GDS, with a particular focus on both the technical

  16. 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.

  17. 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

  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. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhili; Ge, Yuanyuan, E-mail: geyy@gxu.edu.cn; Wan, Liang

    2015-03-21

    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 cm{sup 3}/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.

  2. Philadelphia's Renaissance Schools Initiative after Four Years

    Science.gov (United States)

    Stratos, Kati; Wolford, Tonya; Reitano, Adrienne

    2015-01-01

    In 2010-2011, the School District of Philadelphia (the District) launched its Renaissance Schools Initiative, a program designed to dramatically improve student achievement in the District's lowest performing schools. Some schools became Promise Academies, based on the federal turnaround model, and remained District-operated neighborhood schools.…

  3. Rubus Iconography: Antiquity to the Renaissance

    Science.gov (United States)

    Rubus images from late Antiquity to the Renaissance are described and assessed for botanical and horticultural information. The earliest surviving European blackberry (R. fruticosus L. sp. agg.) image is found on folio 83 in the Juliana Anicia Codex (Codex Vindobonensis) of 512 CE which contains cop...

  4. 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

  5. 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

  6. 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

  7. 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 m......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...

  8. 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.

  9. 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.

  10. 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 ...

  11. 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

  12. The Renaissance or the cuckoo clock.

    Science.gov (United States)

    Pines, Jonathon; Hagan, Iain

    2011-12-27

    '…in Italy, for thirty years under the Borgias, they had warfare, terror, murder and bloodshed, but they produced Michelangelo, Leonardo da Vinci and the Renaissance. In Switzerland, they had brotherly love, they had five hundred years of democracy and peace-and what did that produce? The cuckoo clock'. Orson Welles as Harry Lime: The Third Man. Orson Welles might have been a little unfair on the Swiss, after all cuckoo clocks were developed in the Schwartzwald, but, more importantly, Swiss democracy gives remarkably stable government with considerable decision-making at the local level. The alternative is the battling city-states of Renaissance Italy: culturally rich but chaotic at a higher level of organization. As our understanding of the cell cycle improves, it appears that the cell is organized more along the lines of Switzerland than Renaissance Italy, and one major challenge is to determine how local decisions are made and coordinated to produce the robust cell cycle mechanisms that we observe in the cell as a whole.

  13. 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.

  14. 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...... 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 miniature painting. They all put the subject as both maker and receiver in the center. This was the birth of the modern subject. The development...... 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...

  15. Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: a kinetic approach.

    Science.gov (United States)

    Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K; Mukherjee, Kakali; Saha, Bidyut

    2013-05-15

    The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation.

  16. 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)

  17. 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.

  18. 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.

  19. 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 rat...

  20. Lessons from the Renaissance: The Power of Multiple Knowledge Bases

    Science.gov (United States)

    Whitmire, Kathleen; Beck, Joanna

    2010-01-01

    This article applies the Renaissance paradigm of "Homo universalis" to a 30-year retrospective of services provided in education settings to children and youth with language disorders. It also proposes directions to take for the future. The Renaissance ideal of "Homo universalis" refers to an individual who acquires learning in a wide variety of…

  1. The dawn of the third renaissance in surgery.

    Science.gov (United States)

    Hackam, David J

    2015-08-01

    In this presidential address, I will share my belief that our proud and noble field stands at the dawn of a great renaissance. I further believe that this is the third such renaissance that has occurred in surgery. As described herein, the first renaissance in surgery occurred during the 1600s, which involved a transformation in operative care unlike anything that had been seen since Roman times. This first renaissance was triggered by tumultuous world events but was spurred on by the invention of the printing press. The second renaissance occurred during the 1980s and was triggered by the invention of the computer, which is of equal significance to the printing press 240 years earlier. I believe that this third renaissance shares with the earlier renaissances its transformative nature and its reaction to turmoil, both in the medical and nonmedical worlds. This is a renaissance driven by science, by creativity, and by innovation—resources that are never in short supply within our great profession.

  2. 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…

  3. Accelerated Reader/Reading Renaissance. What Works Clearinghouse Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2007

    2007-01-01

    The Accelerated Reader/Reading Renaissance program (now called Accelerated Reader Best Classroom Practices) is a guided reading intervention in which teachers direct student reading of text. It involves two components. Reading Renaissance, the first component, is a set of recommended principles on guided reading (or teachers' direction of…

  4. Seeing, Hearing and Doing the Renaissance (Part 2)

    Science.gov (United States)

    Osowiecki, Maria

    2005-01-01

    In the last edition of "Teaching History", Maria Osowiecki described in detail the fourth lesson in a five-lesson enquiry entitled: What was remarkable about the Renaissance? She also shared her resources for two lively, interactive activities--the Renaissance Party and a balloon debate. Here she complements that piece with a full…

  5. 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.

  6. 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,

  7. 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.

  8. Changing the Action of Iron from Stoichiometric to Electrocatalytic in the Hydrogenation of Ketones in Aqueous Acidic Media.

    Science.gov (United States)

    Gottardo, Marina; Easton, Max; Fabos, Viktoria; Guo, Si-Xuan; Zhang, Jie; Perosa, Alvise; Selva, Maurizio; Bond, Alan M; Masters, Anthony F; Maschmeyer, Thomas

    2015-11-01

    Cyclohexanone, a model compound chosen to conveniently represent small oxygenates present in the aqueous phase of biomass hydrothermal upgrading streams, was hydrogenated in the presence of electrodeposited iron(0) using aqueous formic or sulfuric acid as a hydrogen donor. Under these conditions, zero-valent iron is consumed stoichiometrically and serves as both a formic acid decomposition site and a hydrogen transfer agent. However, the resulting iron(II) can be used to continuously regenerate iron(0) when a potential is applied to the glassy carbon working electrode. Controlled potential electrolysis experiments show a 17% conversion of cyclohexanone (over 1000 seconds) to cyclohexanol with >80% efficiency of iron deposition from an iron(II) sulfate solution containing formic or sulfuric acid. In the absence of electrodeposited iron, formation of cyclohexanol could not be detected. PMID:26382111

  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. Studies on Micellization of a Polystyrene-b-poly(acrylic acid) Copolymer in Aqueous Media by Pyrene Fluorescence

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Pyrcnc probc and TEM have been employed to investigate the behavior of a polystyrenc-b-poly(acrylic aeid) (PS-b-PAA) copolymer in aqueous solution. A significant annealing temperature effect on the I1/I3 ratio of pyrene was observed and was interpreted in terms ofthe morphological change ofmicellar cores. Anncaling at a temperature higher than the glass transition temperature (Tg) of PS leads to densification ofthe hydrophobic core.

  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. NMR, surface tension and conductance study to investigate host-guest inclusion complexes of three sequential ionic liquids with β-cyclodextrin in aqueous media

    Science.gov (United States)

    Barman, Siti; Ekka, Deepak; Saha, Subhadeep; Roy, Mahendra Nath

    2016-08-01

    Host-guest inclusion complexes of three sequential cationic room temperature surface active ionic liquids, benzyltrialkylammonium chloride [(C6H5CH2)N(CnH2n+1)3Cl; where n = 1, 2, 4] with β-cyclodextrin in aqueous media have been studied using surface tension, conductance and NMR spectroscopy. All the studies have suggested that the hydrophobic benzyl group of ionic liquids is encapsulated inside into the cavity of β-cyclodextrin and played a crucial role in supporting the formation of inclusion complexes. The variation of the thermodynamic parameters with guest size, shape is used to draw inferences about contributions to the overall binding by means of the driving forces, viz., hydrophobic effect, steric hindrance, van der Waal force, and electrostatic force.

  13. 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。

  14. 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

  15. 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

  16. BER OPTIC SENSOR MODIFIED BY GRAFTING OF THE MOLECULARLY IMPRINTED POLYMER FOR THE DETECTION OF AMMONIUM IN AQUEOUS MEDIA

    Directory of Open Access Journals (Sweden)

    N. Lopes,

    2015-07-01

    Full Text Available Subject of Research.The paper deals with novel chemical sensors based on the polymeric optical fibers modified by grafting of the molecularly imprinted polymer for the detection of ammonium in aqueous solutions. Elevated concentrations of ammonium in surface waters lead to their eutrophication, that’s why, monitoring of the content of this ion is very important for the evaluation of surface water quality. However, currently in situ monitoring of relevant parameters in surface waters is constrained by the availability and cost of commercial sensors. Attractive approach to the development of chemical sensors for remote controls is the use of polymeric optical fibers. Polymer optical fibers have high mechanical resistance and low cost, and give the possibility for multiplexing and remote sensing. Method. Polymeric layer imprinted with ammonium ions was grafted on the surface of the methylmethacrylate fiber. Methacrylic acid was used as a monomer, ethylene glycol dimethacylate as a cross-linker, 2.2'-Azobis (2-ethylpropionamidine dihydrochloride as a radical initiator, ammonium as a template and water:ethanol 4:1 mixture as a solvent. Optimization of the imprinted polymer synthesis conditions was carried out using intensity of transmitted light, uniformity of the grafted polymeric layer and response in the aqueous ammonium solutions as optimization criteria. Main Results. Chemical sensors based on the polymeric optical fibers modified by grafting of the molecularly imprinted polymer for the detection of ammonium in aqueous solutions have been developed. New method of the grafting of the molecularly imprinted polymer on the surface of the methylmethacrylate optical fiber has been developed. It was found out, that high concentrations of the monomer and cross-linker in the polymerization solutions cause optical fiber damage while longer polymerization times result in the decrease of the intensity of transmitted light. Optical sensor demonstrating

  17. 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

    Diffusion and compound-specific mixing significantly affect conservative and reactive transport in groundwater. The variability of diffusion coefficients for different solutes has a relevant impact on their displacement at different scales, not only under diffusion-dominated regimes but also under...... to multicomponent ionic dispersion: the dispersive fluxes of the different ions are cross-coupled due to the effects of Coulombic interactions. Such effects are illustrated in flow-through experiments in saturated porous media. Simple strong electrolytes were selected as tracers and their transport was studied...... 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...

  18. 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

  19. 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

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Geszke-Moritz, Malgorzata [Laboratoire Reactions et Genie des Procedes (LRGP), Nancy-University, CNRS, 1 rue Grandville, 54001 Nancy Cedex (France); Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan (Poland); Clavier, Gilles [PPSM, ENS Cachan, CNRS, UniverSud, 61 avenue President Wilson, 94230 Cachan (France); Lulek, Janina [Department of Pharmaceutical Technology, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan (Poland); Schneider, Raphaeel, E-mail: raphael.schneider@ensic.inpl-nancy.fr [Laboratoire Reactions et Genie des Procedes (LRGP), Nancy-University, CNRS, 1 rue Grandville, 54001 Nancy Cedex (France)

    2012-04-15

    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 {mu}M, 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: Black-Right-Pointing-Pointer Quenching of the fluorescence intensity of doped ZnS QDs in the presence of folic acid. Black-Right-Pointing-Pointer New fluorescent sensors for folic acid. Black-Right-Pointing-Pointer Detection of folic acid concentrations as low as 11 {mu}M in aqueous solution. Black-Right-Pointing-Pointer The Perrin model and fluorescence lifetimes of ZnS:Mn QDs demonstrate a static quenching mechanism. Black-Right-Pointing-Pointer Quenching efficiency of ZnS:Cu QDs correlates with the Stern-Volmer model.

  2. 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.

  3. 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.

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Nareman D.H., E-mail: drndahshan@yahoo.com [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, C13, DE-21335 Lüneburg (Germany); Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522 (Egypt); Mahmoud, Waleed M.M. [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, C13, DE-21335 Lüneburg (Germany); Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522 (Egypt); Hadad, Ghada M.; Abdel-Salam, Randa A. [Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522 (Egypt); Kümmerer, Klaus, E-mail: Klaus.Kuemmerer@uni.leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, C13, DE-21335 Lüneburg (Germany)

    2013-01-15

    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.

  6. 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.

  7. 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.

  8. 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

  9. 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)

  10. 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

  11. Enhancement of a novel extracellular uricase production by media optimization and partial purification by aqueous three-phase system.

    Science.gov (United States)

    Ram, Senthoor K; Raval, Keyur; JagadeeshBabu, P E

    2015-01-01

    Uricase (urate: oxygen oxidoreductase, EC 1.7.3.3), an enzyme belonging to the class of oxidoreductases, catalyzes the enzymatic oxidation of uric acid to allantoin and finds a wide variety of application as therapeutic and clinical reagent. In this study, uricase production ability of the bacterial strains isolated from deep litter poultry soil is investigated. The strain with maximum extracellular uricase production capability was identified as Xanthomonas fuscans subsp. aurantifolii based on 16S rRNA sequencing. Effect of various carbon and nitrogen sources on uricase productivity was investigated. The uricase production for this strain was optimized using statistically based experimental designs and resulted in uricase activity of 306 U/L, which is 2 times higher than initial uricase activity. Two-step purification, such as ammonium sulfate precipitation and aqueous two-phase system, was carried out and a twofold increase in yield and specific activity was observed.

  12. Ideas in Context and the Idea of Renaissance Philosophy.

    Science.gov (United States)

    Celenza, Christopher S

    2014-10-01

    This contribution to the symposium marking the publication of the 100th volume in the series Ideas in Context (Cambridge University Press) assesses the significance of the series for work on Renaissance philosophy.

  13. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance.

    Science.gov (United States)

    Edwards, Howell G M

    2011-10-01

    The Renaissance represented a major advance in painting techniques, subject matter, artistic style and the use of pigments and pigment mixtures. However, most pigments in general use were still mineral-based as most organic dyes were believed to be fugitive; the historical study of artists' palettes and recipes has assumed importance for the attribution of art works to the Renaissance period. Although the application of diagnostic elemental and molecular spectroscopic techniques play vital and complementary roles in the analysis of art works, elemental techniques alone cannot definitively provide the data needed for pigment identification. The advantages and limitations of Raman spectroscopy for the definitive diagnostic characterisation of yellow pigments that were in use during the Renaissance is demonstrated here in consideration of heavy metal oxides and sulphides; these data will be compared with those obtained from analyses of synthetic yellow pigments that were available during the eighteenth and nineteenth Centuries which could have been used in unrecorded restorations of Renaissance paintings.

  14. 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 ...

  15. 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

  16. 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.

  17. 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

  18. 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)

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. Future studies on electron scattering; a renaissance

    Science.gov (United States)

    Mason, Nigel J.

    2014-12-01

    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.

  9. A RENAISSANCE PROMOTER OF MODERN SURGERY.

    Science.gov (United States)

    Velenciuc, I; Minea, Raluca; Duceac, Letiţia; Vlad, T

    2016-01-01

    The present paper aims, exploring the history of Renaissance medicine, to evoke the figure and work of the priest, surgeon and anatomist, Guido Guidi (Vidus Vidius) (1509-1569). The XVIth century is considered a period marked by artistic and scientific effervescence in the western part of Europe and Guido Guidi was a first order personality, grandson of Domenico Ghirlandaio and friend of Benvenuto Cellini. He was appointed by the King Francis I the first professor of anatomy and surgery at the newly founded College de France. On demand of the King, he wrote Chirurgia j Graeco in Latinum conversa Vido Vidio Florentino interprete, cum nonnullis eiusdem Vidii comentariis (1544), a beautifully illustrated original surgery book that became for the following two centuries the main source in teaching surgery. Our study realized a detailed assessment of the book and especially of its illustrations belonging to Francesco Salviati. Exploring the life of Guido Guidi, we were also able to point out other significant contributions in the field of anatomy and clinical medicine as De anatome the first book where are presented disarticulated, the bones of the skull base and also the discovery of the chickenpox. Some surgical personalities attributed to him both the elaboration of the term appendix vermiformis and the first description of an aneurysm, he treated with the help of Fallopio. Although forgotten today, Guido Guidi was a leading figure of the Renais sance medicine both in France and Italy.

  10. 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.

  11. 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.

  12. 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.

  13. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

    Science.gov (United States)

    Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

    2016-09-01

    The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

  14. Fractal analysis as a complementary approach to predict the stability of drug delivery nano systems in aqueous and biological media: a regulatory proposal or a dream?

    Science.gov (United States)

    Demetzos, Costas; Pippa, Natassa

    2014-10-01

    The morphology of drug nanocarriers correlates with their functionality, which is mainly shuttled on their surface where most of the interactions and interfacial phenomena occur. The quantification of their morphological fingerprint requires an analytical tool that should be established based on experimental data and can be correlated with their stability. The morphological quantification picture of the advanced Drug Delivery nano Systems (aDDnSs) could be achieved via fractal analysis and by introducing a novel proposed parameter, defined as ωD. This parameter is based on mathematical limits determined experimentally and on already existing theories on the colloidal fractal aggregation process which can correlate the morphological characteristics of aDDnSs with their physicochemical stability in aqueous and biological media. This review article proposes the fractal analysis and the ωD as an analytical tool and prediction parameter, respectively, which are able to promote an attractive and alternative path for studying drug delivery nanocarriers. Moreover, these approaches could facilitate the scale up process of pharmaceutical industry, and could shed more light in the quantification of drug delivery nanosystems.

  15. 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 (1.03 mmol g(-1) at pH 6). The prepared material could be potential sorbent for the extraction of this heavy metal from environmental and drinking waters.

  16. 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

  17. 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

  18. 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 (1.03 mmol g(-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

  19. 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

  20. 78 FR 68134 - Culturally Significant Objects Imported for Exhibition Determinations: “Renaissance to Goya...

    Science.gov (United States)

    2013-11-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Renaissance to Goya: Prints and... ``Renaissance to Goya: Prints and Drawings from Spain,'' imported from abroad for temporary exhibition...

  1. 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.

  2. 76 FR 70805 - Culturally Significant Objects Imported for Exhibition Determinations: “The Renaissance Portrait...

    Science.gov (United States)

    2011-11-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``The Renaissance Portrait From... ``The Renaissance Portrait from Donatello to Bellini,'' imported from abroad for temporary...

  3. 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

  4. Single-walled carbon nanotubes dispersed in aqueous media via non-covalent functionalization: effect of dispersant on the stability, cytotoxicity, and epigenetic toxicity of nanotube suspensions.

    Science.gov (United States)

    Alpatova, Alla L; Shan, Wenqian; Babica, Pavel; Upham, Brad L; Rogensues, Adam R; Masten, Susan J; Drown, Edward; Mohanty, Amar K; Alocilja, Evangelyn C; Tarabara, Volodymyr V

    2010-01-01

    As the range of applications for carbon nanotubes (CNTs) rapidly expands, understanding the effect of CNTs on prokaryotic and eukaryotic cell systems has become an important research priority, especially in light of recent reports of the facile dispersion of CNTs in a variety of aqueous systems including natural water. In this study, single-walled carbon nanotubes (SWCNTs) were dispersed in water using a range of natural (gum arabic, amylose, Suwannee River natural organic matter) and synthetic (polyvinyl pyrrolidone, Triton X-100) dispersing agents (dispersants) that attach to the CNT surface non-covalently via different physiosorption mechanisms. The charge and the average effective hydrodynamic diameter of suspended SWCNTs as well as the concentration of exfoliated SWCNTs in the dispersion were found to remain relatively stable over a period of 4 weeks. The cytotoxicity of suspended SWCNTs was assessed as a function of dispersant type and exposure time (up to 48 h) using general viability bioassay with Escherichia coli and using neutral red dye uptake (NDU) bioassay with WB-F344 rat liver epithelia cells. In the E. coli viability bioassays, three types of growth media with different organic loadings and salt contents were evaluated. When the dispersant itself was non-toxic, no losses of E. coli and WB-F344 viability were observed. The cell viability was affected only by SWCNTs dispersed using Triton X-100, which was cytotoxic in SWCNT-free (control) solution. The epigenetic toxicity of dispersed CNTs was evaluated using gap junction intercellular communication (GJIC) bioassay applied to WB-F344 rat liver epithelial cells. With all SWCNT suspensions except those where SWCNTs were dispersed using Triton X-100 (wherein GJIC could not be measured because the sample was cytotoxic), no inhibition of GJIC in the presence of SWCNTs was observed. These results suggest a strong dependence of the toxicity of SWCNT suspensions on the toxicity of the dispersant and point to

  5. The first translations of Harlem renaissance poetry in Slovenia

    Directory of Open Access Journals (Sweden)

    Jerneja Petrič

    2008-12-01

    Full Text Available From the present-day perspective Harlem Renaissance poetry represents an epoch-making contribution by America's black authors to the mainstream literature. However, in the post World War 1 era black authors struggled for recognition in their homeland. The publication of a German anthology Afrika singt in the late 1920s agitated Europe as well as the German-speaking authors in Slovenia. Mile Klopčič, a representative of the poetry of Social Realism, translated a handful of Har­ lem Renaissance poems into Slovene using, except in two cases, the German anthology as a source text. His translations are formally accomplished but fail to reproduce the cultural significance of the Harlem Renaissance poetry.

  6. 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.

  7. 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 ...

  8. 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

  9. 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.

  10. “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

  11. 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.

  12. 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

  13. 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

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

    DEFF Research Database (Denmark)

    Shaw, Timothy Milton

    2012-01-01

    . 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...

  15. 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...

  16. 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…

  17. Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report

    Science.gov (United States)

    Gold, Eva; Norton, Michael H.; Good, Deborah; Levin, Stephanie

    2012-01-01

    This report presents Year One (2010-11) school level achievement and attendance outcomes and case study findings from fall 2011 that focused on school leadership and instruction. Thirteen schools were included in the first year of Philadelphia's Renaissance Schools Initiative (2010-11). Of these schools: (1) Four K-8 schools were…

  18. A Brief Historical Development of Classical Mathematics before the Renaissance

    Science.gov (United States)

    Debnath, Lokenath

    2011-01-01

    This article deals with a short history of mathematics and mathematical scientists during the ancient and medieval periods. Included are some major developments of the ancient, Indian, Arabic, Egyptian, Greek and medieval mathematics and their significant impact on the Renaissance mathematics. Special attention is given to many results, theorems,…

  19. 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

  20. 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

  1. 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.

  2. 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 education....

  3. 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

  4. 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.

  5. 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

  6. '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

  7. 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

  8. 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

  9. 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

  10. The Influence of the Renaissance on Richard Hooker

    Directory of Open Access Journals (Sweden)

    Grislis Egil

    2014-06-01

    Full Text Available Like many writers after the Renaissance, Hooker was influenced by a number of classical and Neo-Platonic texts, especially by Cicero, Seneca, Hermes Trimegistus, and Pseudo-Dionysius. Hooker’s regular allusions to these thinkers help illuminate his own work but also his place within the broader European context and the history of ideas. This paper addresses in turn the reception of Cicero and Seneca in the early Church through the Middle Ages and Renaissance, Hooker’s use of Ciceronian and Senecan ideas, and finally Hooker’s use of Neo-Platonic texts attributed to Hermes Trismegistus and Dionysius the Areopagite. Hooker will be shown to distinguish himself as a sophisticated and learned interpreter who balances distinctive motifs such as Scripture and tradition, faith, reason, experience, and ecclesiology with a complex appeal to pagan and Christian sources and ideas.

  11. The Influence of Renaissance On Marvel Comics Movies

    Institute of Scientific and Technical Information of China (English)

    郭晨燕

    2016-01-01

    Nowadays, in the movie industry, marvel comics movies play an inevitable role, plenty of super heroes are becoming more and more popular to our spectators, such as:superman, Spider Man, Batman, lron Man, Captain America, Hulk, Thor even the alliances Fantastic 4, The Avengers, Guardians of The Galaxy and so on, and this kind of movies occupies a significant part in the movie market. So why people like the super stares so much? And what sort of national culture can we find in these mov-ies? This thesis concentrate on the questions l just mentioned, from the perspective of the renaissance, I will show you how and in what extent renaissance has influenced the marvel comics movies.

  12. 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.

  13. 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

  14. 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.

  15. 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...

  16. 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 ...

  17. Decisions in the Nuclear Renaissance; Decisiones ante el Renacimiento Nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, J.

    2007-07-01

    Taking into consideration the existing revitalization of nuclear projects, the author highlights some of the barriers that the industry will face in the initial phases of the new era. There are some issues such as the many different requirements imposed for a design to be licensed country by country, or the bottlenecks that may appear in this globalized industry. Thus, it is advisable that the Utilities make decisions in the long term, in order to assure their position in the Nuclear renaissance. (Author)

  18. 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.

  19. 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...

  20. The "Renaissance Child": High Achievement and Gender in Late Modernity

    Science.gov (United States)

    Skelton, Christine; Francis, Becky

    2012-01-01

    This paper draws on the concept of the "Renaissance Child" to illustrate the ways in which gender influences the opportunities and possibilities of high-achieving pupils. Using data from a study of 12-13-year high-achieving boys and girls based in schools in England, the paper considers the ways in which a group of popular boys was able to show an…

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Significant findings concerning the production of Italian Renaissance lustred majolica

    Science.gov (United States)

    Padeletti, G.; Fermo, P.

    2013-12-01

    In the present paper the main results obtained, over a period of more than ten years, from a series of studies concerning the characterization of Italian Renaissance lustred majolicas (from Gubbio and Deruta, Umbria, Italy) are presented. Lustre decoration is a well-known technique, consisting in the application of a thin metallic iridescent film, containing silver and copper nanoparticles, over a previously glazed ceramic object. The technique had its origin in Persia (IX century), was imported by Moorish in Spain, and then developed in central Italy during the Renaissance period. Numerous analytical techniques (among which, ETASS, XRD, UV-Vis, SEM-EDX) have been employed for the characterization of lustred ceramic shards, allowing one to acquire information on both lustre chemical composition and nanostructure. In this way it was shown how some technological parameters, such as the firing conditions, are mandatory to obtain the final result. The presence of a specific marker of the lustre Italian production, i.e., cosalite (Pb2Bi2S5), has been also highlighted. From the study of the ceramic body composition (by means of XRD and ICP-OES and in particular of chemometric techniques) acquired on more than 50 ceramic shards it was possible to discriminate between Deruta and Gubbio production, in this way allowing one to assign objects of uncertain provenance to a specific site. Finally, the most interesting results obtained studying excellent lustred masterpieces from Renaissance belonging to important museums are here presented. In particular, with the use of nondestructive techniques (PIXE, RBS, and portable XRD), the production of Mastro Giorgio Andreoli from Gubbio was investigated. By means of the same analytical approach, one of the first examples of lustre in Italy (the famous Baglioni's albarello) was examined, and the controversial question of its attribution to Italian production was scientifically faced.

  7. 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

  8. “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.

  9. Program Fidelity and Teacher Decisions: A Case Study of the Renaissance Learning Program

    Science.gov (United States)

    Putnam, Jennifer D.

    2011-01-01

    This dissertation was designed to examine the degree to which the fidelity of implementation of the Renaissance Learning program impacts teacher instruction, as well as teacher perception of student reading motivation and achievement. The teachers at a western North Carolina elementary school used the Renaissance Learning program for over 15…

  10. What Works Clearinghouse Quick Review: "Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report"

    Science.gov (United States)

    What Works Clearinghouse, 2012

    2012-01-01

    The study examined the effectiveness of Philadelphia's Renaissance Schools Initiative after one year of implementation. The Renaissance Schools Initiative, which began in the 2010-11 school year, aimed at improving low-performing schools by providing new management, additional resources, and new educational strategies. The study reported that…

  11. From Accountability to Privatization and African American Exclusion: Chicago's "Renaissance 2010"

    Science.gov (United States)

    Lipman, Pauline; Haines, Nathan

    2007-01-01

    This article analyzes Chicago's new Renaissance 2010 school plan to close public schools and reopen them as choice and charter schools. Grounding the analysis in participatory research methods, the authors argue that Chicago's education accountability policies have laid the groundwork for privatization. They furthermore argue that Renaissance 2010…

  12. The University of New Brunswick's Renaissance College: Curricular Evolution and Assessment at the Faculty Level

    Science.gov (United States)

    Zundel, Pierre; Mengel, Thomas

    2007-01-01

    The purpose of this chapter is to draw some general lessons on curricular evolution processes and practices at the faculty level emerging from the creation of Renaissance College at the University of New Brunswick and the implementation of its BPhil program. The authors proceed by induction, working from the specific case of Renaissance College to…

  13. 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...

  14. 75 FR 61232 - RIEF RMP LLC and Renaissance Technologies LLC; Notice of Application

    Science.gov (United States)

    2010-10-04

    ... COMMISSION RIEF RMP LLC and Renaissance Technologies LLC; Notice of Application September 28, 2010. AGENCY... formed for the benefit of eligible employees of Renaissance Technologies LLC (``RTC'') and its affiliates... in condition 3. \\3\\ The investment objectives and program of one such Third Party Fund,...

  15. 75 FR 55613 - General Motors Corporation, Renaissance Center, Including On-Site Leased Workers From Accretive...

    Science.gov (United States)

    2010-09-13

    ... on May 20, 2010 (75 FR 28299). At the request of the State agency, the Department reviewed the... Employment and Training Administration General Motors Corporation, Renaissance Center, Including On-Site... of General Motors Corporation, Renaissance Center, including on-site leased workers from...

  16. Renaissance Schools Fund-Supported Schools: Early Outcomes, Challenges, and Opportunities

    Science.gov (United States)

    Young, Viki M.; Humphrey, Daniel C.; Wang, Haiwen; Bosetti, Kristin R.; Cassidy, Lauren; Wechsler, Marjorie E.; Rivera, Elizabeth; Murray, Samantha; Schanzenbach, Diane Whitmore

    2009-01-01

    Chicago's Renaissance 2010 seeks to create 100 new and autonomous schools by 2010. These new schools are expected to increase choice for parents and students, enact innovative practices, and help create a portfolio of schools designed to make the Chicago Public Schools (CPS) more diversified, responsive, and effective. Renaissance Schools Fund…

  17. The Renaissance Engineer: Educating Engineers in a Post-9/11 World.

    Science.gov (United States)

    Akay, Adnan

    2003-01-01

    Examines the role of engineers and their responsibilities in society, especially after the events of September 11, 2001. Suggests the need for a renaissance in engineering education and recommends cultivating a new generation of renaissance engineers based on the recognition of individual talent and customizing education accordingly. (Author/YDS)

  18. 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…

  19. 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;…

  20. 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.

  1. 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.

  2. Nuclear renaissance, the challenge; Renacimiento Nuclear, Los desafios

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, J.; Aycart, J.

    2009-07-01

    The Nuclear Industry has been able to get prepared for the Renaissance by overcoming many different challenges. Most of them related to shortage in capabilities and resources. However, as new builds approach, new challenges appear in the horizon. Now, those are mostly related to the risk management embedded in huge projects like these. This Article provides a vision on how to face those new challenges, so that the industry will not be damaged in its credibility by lack of commitments or failed executions. (Author)

  3. Anatomy and the Body in Renaissance Protestant Psychology.

    Science.gov (United States)

    Cellamare, Davide

    2014-01-01

    This article addresses the use of anatomical knowledge in Renaissance works on the soul produced at northern European universities, as well as the notions of 'body' and 'soul' that emerge from them. It examines specifically Philip Melanchthon's and Rudolph Snell van Royen's treatises on the soul. This analysis shows that a number of Protestant professors of arts and medicine generally considered the anatomical study of the body--which they conceived of as a teleologically organised machina (machine)--to be instrumental in studying the human soul. This article will, however, also document that the reasons motivating this conception were not uniform.

  4. Foot deformities in Renaissance paintings. A mystery of symbolism, artistic licence, illusion and true representation in five renowned Renaissance painters.

    Science.gov (United States)

    Lazzeri, D; Castello, M F; Grassetti, L; Dashti, T; Zhang, Y X; Persichetti, P

    2015-01-01

    Although Renaissance artists were skilled in representing normal anatomy, a close look at some paintings reveals anatomical variations in the depiction of the feet of human figures. A systematic review has identified 25 paintings by five artists in which the presumptive medico-artistic diagnosis of congenital or acquired foot deformity seems to be varyingly present. The connection between these five painters and what factors have influenced artists' style in the depiction of such deformities is discussed. The possible iconography and medical-historical meaning of such variations, as well as the possibility of artistic licence and real representation that drove the painters to depict these deformities, is explored and debated.

  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. 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.)

  7. 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.)

  8. Breastfeeding and weaning in renaissance Italy: the Medici children.

    Science.gov (United States)

    Giuffra, Valentina; Fornaciari, Gino

    2013-06-01

    Abstract Exploration of the Medici Chapels in the Basilica of San Lorenzo in Florence, Italy, revealed the burials of nine infantile members of the Medici family. Eight children were found in the intact tomb of the last Grand Duke GianGastone (1671-1737), and another child was exhumed from the Chapel of Grand Duke Ferdinando I (1549-1609). Skeletal ages ranged from newborn to 5 years, suggesting an identification with infantile members of the family. A paleonutritional study has been performed on the bone samples of all members of the Medici family exhumed so far. Carbon and nitrogen stable isotope analysis of bone collagen was used to detect the timing of the weaning process in this population. The (15)N values of the Medici children are significantly higher than those of adults, indicating that these infants were breastfed for a long time period. In particular, the levels of (15)N are high before the second year but decrease in older children, evidently after weaning, reaching the levels of adults. During the Renaissance, it was the common opinion that children should not be weaned before the second year of life. Archival documents suggest that the Medici children were never weaned before that age and, in most cases, even some months later. Combination of paleonutritional data and historical sources allowed reconstruction of the breastfeeding and weaning patterns of this aristocratic Renaissance class.

  9. 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.

  10. Green roofs and the urban renaissance in Britain

    Energy Technology Data Exchange (ETDEWEB)

    Frith, M. [Peabody Trust, London (United Kingdom); Farrell, J. [Greater London Authority (United Kingdom)

    2003-07-01

    Green roofs in Britain are not very widespread. Their entry into the main stream has been slow due to conservative architectural design, planning, and a general lack of knowledge in green building practices. The national government has not issued any legislation or guidance, nor has it offered incentives to developers. In 1999, the British Government initiated a wide-ranging program in urban renaissance to revitalize towns and cities. The program deals mainly with high density development located on brownfields. Green roof technology has not yet entered the urban renaissance initiative, and the importance of brownfield land for biodiversity and amenity has not been recognized. However, London has seen some progress in environmental urban design and green roofs. Links have been established between the benefits of green roofs and the cross-sectoral Biodiversity Action Plan of the Government. Construction is being reassessed, as are building designs, urban green spaces, and climate change. Sustainable development in the City of London is the responsibility of the Mayor. It was emphasized that opportunities exist for establishing policies that promote green roofs that offer social benefits. The voluntary and public sectors have come up with several innovative projects. 47 refs.

  11. 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).

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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)

  17. 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

  18. Complete Transmetalation in a Metal-Organic Framework by Metal Ion Metathesis in a Single Crystal for Selective Sensing of Phosphate Ions in Aqueous Media.

    Science.gov (United States)

    Asha, K S; Bhattacharjee, Rameswar; Mandal, Sukhendu

    2016-09-12

    A complete transmetalation has been achieved on a barium metal-organic framework (MOF), leading to the isolation of a new Tb-MOF in a single-crystal (SC) to single-crystal (SC) fashion. It leads to the transformation of an anionic framework with cations in the pore to one that is neutral. The mechanistic studies proposed a core-shell metal exchange through dissociation of metal-ligand bonds. This Tb-MOF exhibits enhanced photoluminescence and acts as a selective sensor for phosphate anion in aqueous medium. Thus, this work not only provides a method to functionalize a MOF that can have potential application in sensing but also elucidates the formation mechanism of the resulting MOF.

  19. 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.

  20. Vibrational analysis of amino acids and short peptides in aqueous media. V. The effect of the disulfide bridge on the structural features of the peptide hormone somatostatin-14.

    Science.gov (United States)

    Hernández, Belén; Carelli, Claude; Coïc, Yves-Marie; De Coninck, Joël; Ghomi, Mahmoud

    2009-09-24

    To emphasize the role played by the S-S bridge in the structural features of somatostatin-14 (SST-14), newly recorded CD and Raman spectra of this cyclic peptide and its open analogue obtained by Cys-->Ser substitution are presented. CD spectra of both peptides recorded in aqueous solutions in the 100-500 microM concentration range are strikingly similar. They reveal principally that random conformers constitute the major population in both peptides. Consequently, the S-S bridge has no structuring effect at submillimolar concentrations. In methanol, the CD spectrum of somatostatin-14 keeps globally the same spectral shape as that observed in water, whereas its open analogue presents a major population of helical conformers. Raman spectra recorded as a function of peptide concentration (5-20 mM) and also in the presence of 150 mM NaCl provide valuable conformational information. All Raman spectra present a mixture of random and beta-hairpin structures for both cyclic and open peptides. More importantly, the presence or the absence of the disulfide bridge does not seem to influence considerably different populations of secondary structures within this range of concentrations. CD and Raman data obtained in the submillimolar and millimolar ranges of concentrations, respectively, lead us to accept the idea that SST-14 monomers aggregate upon increasing concentration, thus stabilizing beta-hairpin conformations in solution. However, even at high concentrations, random conformers do not disappear. Raman spectra of SST-14 also reveal a concentration effect on the flexibility of the S-S linkage and consequently on that of its cyclic part. In conclusion, although the disulfide linkage does not seem to markedly influence the SST-14 conformational features in aqueous solutions, its presence seems to be necessary to ensure the flexibility of the cyclic part of this peptide and to maintain its closed structure in lower dielectric constant environments.

  1. Modeling seismic stimulation: Enhanced non-aqueous fluid extraction from saturated porous media under pore-pressure pulsing at low frequencies

    Science.gov (United States)

    Lo, Wei-Cheng; Sposito, Garrison; Huang, Yu-Han

    2012-03-01

    Seismic stimulation, the application of low-frequency stress-pulsing to the boundary of a porous medium containing water and a non-aqueous fluid to enhance the removal of the latter, shows great promise for both contaminated groundwater remediation and enhanced oil recovery, but theory to elucidate the underlying mechanisms lag significantly behind the progress achieved in experimental research. We address this conceptual lacuna by formulating a boundary-value problem to describe pore-pressure pulsing at seismic frequencies that is based on the continuum theory of poroelasticity for an elastic porous medium permeated by two immiscible fluids. An exact analytical solution is presented that is applied numerically using elasticity parameters and hydraulic data relevant to recent proof-of-principle laboratory experiments investigating the stimulation-induced mobilization of trichloroethene (TCE) in water flowing through a compressed sand core. The numerical results indicated that significant stimulation-induced increases of the TCE concentration in effluent can be expected from pore-pressure pulsing in the frequency range of 25-100 Hz, which is in good agreement with what was observed in the laboratory experiments. Sensitivity analysis of our numerical results revealed that the TCE concentration in the effluent increases with the porous medium framework compressibility and the pulsing pressure. Increasing compressibility also leads to an optimal stimulation response at lower frequencies, whereas changing the pulsing pressure does not affect the optimal stimulation frequency. Within the context of our model, the dominant physical cause for enhancement of non-aqueous fluid mobility by seismic stimulation is the dilatory motion of the porous medium in which the solid and fluid phases undergo opposite displacements, resulting in stress-induced changes of the pore volume.

  2. The Renaissance and the universal surgeon: Giovanni Andrea Della Croce, a master of traumatology.

    Science.gov (United States)

    Di Matteo, Berardo; Tarabella, Vittorio; Filardo, Giuseppe; Viganò, Anna; Tomba, Patrizia; Marcacci, Maurilio

    2013-12-01

    All the medical knowledge of all time in one book, the universal and perfect manual for the Renaissance surgeon, and the man who wrote it. This paper depicts the life and works of Giovanni Andrea della Croce, a 16th Century physician and surgeon, who, endowed with true spirit of Renaissance humanism, wanted to teach and share all his medical knowledge through his opus magnum, titled "Universal Surgery Complete with All the Relevant Parts for the Optimum Surgeon". An extraordinary book which truly represents a defining moment and a founding stone for traumatology, written by a lesser known historical personality, but nonetheless the Renaissance Master of Traumatology.

  3. 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)

  4. Ethiopia's Grand Renaissance Dam: Implications for Downstream Riparian Countries

    Science.gov (United States)

    Zhang, Y.; Block, P. J.; Hammond, M.; King, A.

    2013-12-01

    Ethiopia has begun seriously developing their significant hydropower potential by launching construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile River to facilitate local and regional growth. Although this has required substantial planning on Ethiopia's part, no policy dictating the reservoir filling rate strategy has been publicly issued. This filling stage will have clear implications on downstream flows in Sudan and Egypt, complicated by evaporative losses, climate variability, and climate change. In this study, various filling policies and future climate states are simultaneously explored to infer potential streamflow reductions at Lake Nasser, providing regional decision-makers with a set of plausible, justifiable, and comparable outcomes. Schematic of the model framework Box plots of 2017-2032 percent change in annual average streamflow at Lake Nasser for each filling policy constructed from the 100 time-series and weighted precipitation changes. All values are relative to the no dam policy and no changes to future precipitation.

  5. 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.”

  6. 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.

  7. A scholarly intermediary between the Ottoman Empire and Renaissance Europe.

    Science.gov (United States)

    Morrison, Robert

    2014-03-01

    This essay studies Moses Galeano, a Jewish scholar with ties to Crete and the Ottoman Sultan's court, who traveled to the Veneto around 1500. After describing Galeano's intellectual milieu, it focuses, first, on circumstantial evidence that he transmitted information central to the rise of Renaissance astronomy. Galeano knew of theories that strongly resemble portions of astronomy texts written by Giovanni Battista Amico and Girolamo Fracastoro at Padua a few decades later. He also knew about theories pioneered by the Damascene Ibn al-Shāţir (d. 1375) that strongly resemble portions of Copernicus's work. Next, the article turns to concrete evidence showing that Galeano was part of a network of Jewish scholars who did have contact with Christian scholars in Europe. The essay concludes that, while it is impossible to prove that Galeano had direct contact with Copernicus, he most likely had contact with some European astronomer(s) in the Veneto.

  8. 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.

  9. Raman spectroscopic study of "The Malatesta": a Renaissance painting?

    Science.gov (United States)

    Edwards, Howell G M; Vandenabeele, Peter; Benoy, Timothy J

    2015-02-25

    Raman spectroscopic analysis of the pigments on an Italian painting described as a "Full Length Portrait of a Gentleman", known also as the "Malatesta", and attributed to the Renaissance period has established that these are consistent with the historical research provenance undertaken earlier. Evidence is found for the early 19th Century addition of chrome yellow to highlighted yellow ochre areas in comparison with a similar painting executed in 1801 by Sir Thomas Lawrence of John Kemble in the role of Hamlet, Prince of Denmark. The Raman data are novel in that no analytical studies have previously been made on this painting and reinforces the procedure whereby scientific analyses are accompanied by parallel historical research.

  10. 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

  11. A fluorescent chemodosimeter for Hg2+ based on a spirolactam ring-opening strategy and its application towards mercury determination in aqueous and cellular media.

    Science.gov (United States)

    Kumar, Kempahanumakkagaari Suresh; Ramakrishnappa, Thippeswamy; Balakrishna, R Geetha; Pandurangappa, Mallingappagari

    2014-01-01

    A novel fluorescent chemosensor rhodamine B phenyl hydrazide (RBPH) for Hg(2+) was designed and synthesized. This probe is highly sensitive, selective, and irreversible for Hg(2+) and exhibits fluorescent response at 580 nm. RBPH also displayed detectable color change from colorless to pink upon treatment with Hg(2+). This property has been utilized as naked eye detection for Hg(2+) in various industrial samples. Fluorescence microscopic experiments demonstrated that this chemosensor is cell permeable and can be used for fluorescence imaging of Hg(2+) in cellular media. This probe can detect Hg(2+) with good linear relationships from 1 to 100 nM with r = 0.99983 and the limit of detection were found to be 0.019 nM with ± 0.91 % RSD at 10 nM concentrations.

  12. 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.

  13. 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)

  14. Degradation of antidepressant drug fluoxetine in aqueous media by ozone/H2O2 system: process optimization using central composite design.

    Science.gov (United States)

    Aghaeinejad-Meybodi, Abbas; Ebadi, Amanollah; Shafiei, Sirous; Khataee, Alireza; Rostampour, Mohammad

    2015-01-01

    The main objective of this work is the modelling and optimization of antidepressant drug fluoxetine degradation in aqueous solution by ozone/H2O2 process using central composite design. The operational parameters were ozone concentration, initial hydrogen peroxide concentration, reaction time and initial fluoxetine concentration. A good agreement between the predicted values of fluoxetine removal and experimental results were observed (R2=0.976 and Adj-R2=0.955). Pareto analysis indicated that all selected factors and some interactions were effective on the removal efficiency. It was found that the reaction time is the most effective parameter in the ozone/H2O2 process. The maximum removal efficiency (86.14%) was achieved at ozone concentration of 30 mg L(-1), initial H2O2 concentration of 0.02 mM, reaction time of 20 min and initial fluoxetine concentration of 50 mg L(-1) as the optimum conditions.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Chicago's Renaissance 2010: Building on School Reform in the Age of Accountability

    Science.gov (United States)

    Duncan, Arne

    2006-01-01

    In response to Mr. Ayers and Mr. Klonsky, Mr. Duncan argues that Chicago's Renaissance 2010 initiative is holding adults accountable by closing low-performing schools rather than trapping children in a failing educational environment.

  20. 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...

  1. Ionic Liquid Surfactant Mediated Structural Transitions and Self-Assembly of Bovine Serum Albumin in Aqueous Media: Effect of Functionalization of Ionic Liquid Surfactants.

    Science.gov (United States)

    Singh, Gurbir; Kang, Tejwant Singh

    2015-08-20

    The self-assembly of globular protein bovine serum albumin (BSA) has been investigated in aqueous solutions of ionic liquid surfactants (ILSs), 1-dodecyl-3-methyl imidazolium chloride, [C12mim][Cl], and its amide, [C12Amim][Cl], and ester, [C12Emim][Cl], functionalized counterparts. Dynamic light scattering (DLS) has provided insights into the alterations in hydrodynamic radii (D(h)) of BSA as a function of concentration of ILSs establishing the presence of different types of BSA-ILS complexes in different concentration regimes of ILSs. Isothermal titration calorimetry (ITC) has been exploited to quantify the ILSs interacting with BSA in dilute concentration regime of ILSs. The zeta-potential measurements shed light on changes in the charged state of BSA. The morphology of various self-assembled structures of BSA in different concentration regimes of ILSs have been explored using confocal laser scanning microscopy (CLSM) and scanning electron microscopy. The structural variations in ILSs have been found to produce remarkable effect on the nature and morphology of self-assembled structures of BSA. The presence of nonfunctionalized [C12mim][Cl] IL at all investigated concentrations has led to the formation of unordered large self-assembled structures of BSA. On the other hand, in specific concentration regimes, ordered self-assembled structures such as long rods and right-handedly twisted helical amyloid fibers have been observed in the presence of functionalized [C12Amim][Cl] and [C12Emim][Cl] ILSs, respectively. The nature of the formed helical fibers as amyloid ones has been confirmed using FTIR spectroscopy. Steady-state fluorescence and circular dichroism (CD) spectroscopy have provided insights into folding and unfolding of BSA as fashioned by interactions with ILSs in different concentration regimes supporting the observations made from other studies.

  2. Facile synthesis of magnetic biochar/Fe3O4 nanocomposites using electro-magnetization technique and its application on the removal of acid orange 7 from aqueous media.

    Science.gov (United States)

    Jung, Kyung-Won; Choi, Brian Hyun; Jeong, Tae-Un; Ahn, Kyu-Hong

    2016-11-01

    This study introduces a new methodology to synthesize magnetic biochar/Fe3O4 nanocomposites (M-BC) from marine macroalgae using a facile electro-magnetization technique. M-BC was prepared by stainless steel electrode-based electrochemical system, followed by pyrolysis. Physical and chemical analyses revealed that the porosity and magnetic properties were simultaneously improved via the electro-magnetization process, which enabled not only higher adsorption performance, but also easier separation/recovery from aqueous media at post-adsorption stage using a bar magnet. The adsorption equilibrium studies reveal that the Sips model satisfactorily predicts the adsorption capacity, which found to be 190, 297, and 382mgg(-1) at 10, 20, and 30°C, respectively. The overall findings indicate that one-step electro-magnetization technique can be effectively utilized for the fabrication of biochar with concurrent acquisition of porosity and magnetism, which can bring about new directions in the practical use of adsorption process in environment remediation and mitigate crises originating from it. PMID:27638463

  3. 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

  4. 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

  5. The occurrence of phi in dento-facial beauty of fine art from antiquity through the Renaissance.

    Science.gov (United States)

    Wiener, R Constance; Wiener Pla, Regina M

    2012-01-01

    External beauty is a complex construct that influences lives and may be impacted by dentists. Beauty is not easily quantified, but one cited anthropometric of beauty is the ratio phi, the number 1.618033(...). This study examined phi as a measure of female frontal facial beauty in classic Western art, using pre- Renaissance (N = 30), and Renaissance (N = 30) artwork. Four horizontal and five vertical ratios were determined in the works of art, which were then compared with the phi ratio. All horizontal ratios for both pre-Renaissance and Renaissance artwork were similar to each other, but did not contain the phi ratio (P Renaissance and Renaissance art-work did contain the phi ratio within their confidence intervals with the exception of the vertical ratio, "intereye point to soft tissue menton/ intereye point to stomion", that was found to be less than phi in the Renaissance group. The study provides evidence of the presence of the phi ratio in vertical aspect of females in artwork from pre-Renaissance through the Renaissance demonstrating consistent temporal preferences. Therefore, the phi ratio seems to be an important consideration in altering vertical facial dimensions in full mouth rehabilitation and reconstructive orthognathic surgery involving females.

  6. Reformation and/or Renaissance? A comparison between John Calvin’s and Thabo Mbeki’s ideas of renewal

    Directory of Open Access Journals (Sweden)

    B.J. van der Walt

    2002-08-01

    Full Text Available This essay compares the differences and similarities between the European Renaissance (±1300 – ±1600 and the African Renaissance in order to determine what an apposite Christian attitude would be. The first section describes the European Renaissance as a reaction to the Middle Ages and a return to the original sources of Western civilisation. Two different trends are distinguished, viz. classical humanism and evangelical humanism. The ideas of the great Renaissance thinker and evangelical humanist, John Calvin, about reformation receive special attention in this regard. He learned much from his contemporaries, but did so in a critical, independent way. From the five different Christian worldviews which crystallised during the Renaissance epoch, his Reformational worldview was the most strongly biblically founded one. The second main part of the essay first asks some critical questions about the African Renaissance and then provides a brief historical survey of past efforts at an African Renaissance, followed by an exposition and evaluation of Thabo Mbeki’s ideas about an African Renaissance. The third main section of the essay poses the question as to what role Christianity can and should play in the African Renaissance. Similar to the attitude of Calvin, we should both learn from it and contribute to it from the perspective of a Christian worldview.

  7. 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)

  8. 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.

  9. 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)

  10. Pseudobulbar paralysis in the Renaissance: Cosimo I de' Medici case.

    Science.gov (United States)

    Arba, F; Inzitari, D; Lippi, D

    2014-07-01

    Cosimo I de' Medici (1519-1574) was the first Grand Duke of Tuscany. He was one of the most important members of the Medici family. He was an excellent conqueror and a good politician. Moreover, he was able to attract and encourage artists, scientists and architects to promote Florence as the cultural capital of the Italian Renaissance. Historical chronicles report that he suffered from a stroke when he was 49 years old. Together with the acute manifestation of stroke, he displayed peculiar symptoms. He had gait disturbances and sphincter dysfunctions. His language became poor and hard to understand. His mood was very fluctuating and in the last years of his life he was a short-tempered man. In addition, he had a characteristic symptom, so-called pathological laughing and crying. The course of his disease was slow and stuttering. Taken together, these data seem to be one of the first reports of pseudobulbar paralysis. The disease of Cosimo I was probably due to a chronic cerebral vasculopathy, known as small vessels disease. We discuss this hypothesis regarding an ancient clinical case, with the support of current studies.

  11. Patient-Reported Safety Information: A Renaissance of Pharmacovigilance?

    Science.gov (United States)

    Härmark, Linda; Raine, June; Leufkens, Hubert; Edwards, I Ralph; Moretti, Ugo; Sarinic, Viola Macolic; Kant, Agnes

    2016-10-01

    The role of patients as key contributors in pharmacovigilance was acknowledged in the new EU pharmacovigilance legislation. This contains several efforts to increase the involvement of the general public, including making patient adverse drug reaction (ADR) reporting systems mandatory. Three years have passed since the legislation was introduced and the key question is: does pharmacovigilance yet make optimal use of patient-reported safety information? Independent research has shown beyond doubt that patients make an important contribution to pharmacovigilance signal detection. Patient reports provide first-hand information about the suspected ADR and the circumstances under which it occurred, including medication errors, quality failures, and 'near misses'. Patient-reported safety information leads to a better understanding of the patient's experiences of the ADR. Patients are better at explaining the nature, personal significance and consequences of ADRs than healthcare professionals' reports on similar associations and they give more detailed information regarding quality of life including psychological effects and effects on everyday tasks. Current methods used in pharmacovigilance need to optimise use of the information reported from patients. To make the most of information from patients, the systems we use for collecting, coding and recording patient-reported information and the methodologies applied for signal detection and assessment need to be further developed, such as a patient-specific form, development of a severity grading and evolution of the database structure and the signal detection methods applied. It is time for a renaissance of pharmacovigilance.

  12. The Authoritarian Constitution versus the National Renaissance Front

    Directory of Open Access Journals (Sweden)

    Florin GRECU

    2013-06-01

    Full Text Available On February 27th, 1938 the Constitution laid the ideological and theoretical foundations for the birth of the sole party, called by the new regime The National Renaissance Front (NRF and proclaimed as the only political entity in the state. The NRF was strongly militarized in all its management structures starting with the Directorate to the Superior National Council, because of its corporate-like structure according to constitutional principles and because people were only allowed and granted positions in the party, state or Parliament if they actually had a job. The constitutional order of the monarchy overwrote the stately European or native authoritarian theories by overestimating the state and minimalizing individual rights and freedom. At that time one would not know what regime people who voted for the new regime consecrated by the 27th of February 1938 Constitution had been living in and some of the parliament declarations of the regime’s representatives, when analysed critically, would try to bring light on the article ahead.

  13. Avatara and Sakti : Traditional symbols in the Hindu renaissance

    Directory of Open Access Journals (Sweden)

    Eric J. Sharpe

    1975-01-01

    Full Text Available The Hindu Renaissance is commonly regarded as having begun seriously in the 1870's, consequent upon the foundation in 1875 of the Ārya Samāj in the West of India.' But this is in many ways a date of convenience. The roots of the movement go back, particularly as far as Bengal is concerned, to the time of Rammohun Roy, when on the one hand there was created a serious, though small-scale. Hindu reform movement, and on the other there was introduced into Calcutta the remarkable catalyst of Western education. Hindu reform and Western education were closely linked for the greater part of the nineteenth century. The early Hindu reform movements to a very great extent shared the same characteristics: small-scale and elitist, they were not designed to appeal, and did not appeal, to the masses. The Brāhma Samāj, for instance, never succeeded in achieving popularity; it began and continued very largely as a somewhat rarefied worship-society. But the years between 1893 and 1897 were the years of Swāmi Vivekānanda's "mission" to the World's Parliament of Religions in Chicago and his tours in the countries of the West. Perhaps it was in the figure of the Swāmi that the Indian national movement found its first powerful human symbol.

  14. A brief historical development of classical mathematics before the Renaissance

    Science.gov (United States)

    Debnath, Lokenath

    2011-07-01

    'If you wish to foresee the future of mathematics our proper course is to study the history and present condition of the science.' Henri Poincaré 'It is India that gave us the ingenious method of expressing all numbers by ten symbols, each symbol receiving a value of position, as well as an absolute value. We shall appreciate the grandeur of the achievement when we remember that it escaped the genius of Archimedes and Apollonius.' P.S. Laplace 'The Greeks were the first mathematicians who are still 'real' to us today. Oriental mathematics may be an interesting curiosity, but Greek mathematics is the real thing. The Greek first spoke of a language which modern mathematicians can understand.' G.H. Hardy This article deals with a short history of mathematics and mathematical scientists during the ancient and medieval periods. Included are some major developments of the ancient, Indian, Arabic, Egyptian, Greek and medieval mathematics and their significant impact on the Renaissance mathematics. Special attention is given to many results, theorems, generalizations, and new discoveries of arithmetic, algebra, number theory, geometry and astronomy during the above periods. A number of exciting applications of the above areas is discussed in some detail. It also contains a wide variety of important material accessible to college and even high school students and teachers at all levels. Included also is mathematical information that puts the professionals and prospective mathematical scientists at the forefront of current research.

  15. Differentially selective chemosensor with fluorescence off-on responses on Cu(2+) and Zn(2+) ions in aqueous media and applications in pyrophosphate sensing, live cell imaging, and cytotoxicity.

    Science.gov (United States)

    Anbu, Sellamuthu; Ravishankaran, Rajendran; Guedes da Silva, M Fátima C; Karande, Anjali A; Pombeiro, Armando J L

    2014-07-01

    A new benzoyl hydrazone based chemosensor R is synthesized by Schiff base condensation of 2,6-diformyl-4-methylphenol and phenyl carbohydrazide and acts as a highly selective fluorescence sensor for Cu(2+) and Zn(2+) ions in aqueous media. The reaction of R with CuCl2 or ZnCl2 forms the corresponding dimeric dicopper(II) [Cu2(R)(CH3O)(NO3)]2(CH3O)2 (R-Cu(2+)) and dizinc(II) [Zn2(R)2](NO3)2 (R-Zn(2+)) complexes, which are characterized, as R, by conventional techniques including single-crystal X-ray analysis. Electronic absorption and fluorescence titration studies of R with different metal cations in a CH3CN/0.02 M HEPES buffer medium (pH = 7.3) show a highly selective binding affinity only toward Cu(2+)and Zn(2+) ions even in the presence of other commonly coexisting ions such as Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Fe(2+), Fe(3+), Co(2+), Ni(2+), Cd(2+), and Hg(2+). Quantification of the fluorescence titration analysis shows that the chemosensor R can indicate the presence of Cu(2+)and Zn(2+) even at very low concentrations of 17.3 and 16.5 ppb, respectively. R-Zn(2+) acts as a selective metal-based fluorescent sensor for inorganic pyrophosphate ion (PPi) even in the presence of other common anions such as F(-), Cl(-), Br(-), I(-), CH3COO(-), CO3(2-), HCO3(-), N3(-), SO4(2-), PPi, AMP, ADP, and ATP in an aqueous medium. The propensity of R as a bioimaging fluorescent probe to detect Cu(2+) and Zn(2+) ions in human cervical HeLa cancer cell lines and their cytotoxicity against human cervical (HeLa), breast cancer (MCF7), and noncancer breast epithelial (MCF10a) cells have also been investigated. R-Cu(2+) shows better cytotoxicity and sensitivity toward cancer cells over noncancer cells than R and R-Zn(2+) under identical conditions, with the appearance of apoptotic bodies.

  16. 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...

  17. Renaissance plays as a useful source for the comparison between English and Croatian early modern medicine.

    Science.gov (United States)

    Atalic, Bruno

    2012-01-01

    This paper evaluates the differences between English and Croatian views of early modern medicine through the respective Renaissance plays. As Renaissance made no particular distinction between arts and sciences, plays of that time provide a very common source of medical narrative. During Renaissance both languages produced high literary achievements, which makes them exemplars among their Germanic and Slavic counterparts, and justifies this comparison, regardless of their significant differences. One should bear in mind that while England was a unified kingdom, with London as the major cultural centre, Croatia's division among the neighbouring powers produced several prominent cultural centres such as Zadar, Šibenik, Split, Hvar, Korčula, and the most important one, Dubrovnik. One should also bear in mind that the golden age of Croatian Renaissance plays had finished as early as 1567 with the death of Marin DrŽić, before it even started in England with the foundation of the first permanent theatrical companies in 1576. Along these lines, this paper compares their early modern attitudes toward medicine in general and men and women practitioners in particular. In this respect, it evaluates the influences of the origin, patronage, and religion of their authors. Special attention is given to William Shakespeare (1564-1616) and Marin DrŽić (1508-1567) as the exemplars of English and Croatian Renaissance literature.

  18. “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.

  19. 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。

  20. Ce-Fe-modified zeolite-rich tuff to remove Ba(2+)-like (226)Ra(2+) in presence of As(V) and F(-) from aqueous media as pollutants of drinking water.

    Science.gov (United States)

    Olguín, María Teresa; Deng, Shuguang

    2016-01-25

    The sorption behavior of the Ba(2+)-like (226)Ra(2+) in the presence of H2AsO4(-)/HAsO4(2-) and F(-) from aqueous media using Ce-Fe-modified zeolite-rich tuff was investigated in this work. The Na-modified zeolite-rich tuff was also considered for comparison purposes. The zeolite-rich tuff collected from Wyoming (US) was in contact with NaCl and CeCl3-FeCl3 solutions to obtain the Na- and Ce-Fe-modified zeolite-rich tuffs (ZUSNa and ZUSCeFe). These zeolites were characterized by scanning electron microscopy and X-ray diffraction. The BET-specific surface and the points of zero charge were determined as well as the content of Na, Ce and Fe by neutron activation analysis. The textural characteristics and the point of zero charge were changed by the presence of Ce and Fe species in the zeolitic network. A linear model described the Ba(2+)-like (226)Ra(2+) sorption isotherms and the distribution coefficients (Kd) varied with respect to the metallic species present in the zeolitic material. The As(V) oxianionic chemical species and F(-) affected this parameter when the Ba(2+)-like (226)Ra(2+)-As(V)-F(-) solutions were in contact with ZUSCeFe. The H2AsO4(-)/HAsO4(2-) and F(-) were adsorbed by ZUSCeFe in the same amount, independent of the concentration of Ba(2+)-like (226)Ra(2+) in the initial solution.

  1. 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

  2. The golden beauty: brain response to classical and renaissance sculptures.

    Science.gov (United States)

    Di Dio, Cinzia; Macaluso, Emiliano; Rizzolatti, Giacomo

    2007-01-01

    Is there an objective, biological basis for the experience of beauty in art? Or is aesthetic experience entirely subjective? Using fMRI technique, we addressed this question by presenting viewers, naïve to art criticism, with images of masterpieces of Classical and Renaissance sculpture. Employing proportion as the independent variable, we produced two sets of stimuli: one composed of images of original sculptures; the other of a modified version of the same images. The stimuli were presented in three conditions: observation, aesthetic judgment, and proportion judgment. In the observation condition, the viewers were required to observe the images with the same mind-set as if they were in a museum. In the other two conditions they were required to give an aesthetic or proportion judgment on the same images. Two types of analyses were carried out: one which contrasted brain response to the canonical and the modified sculptures, and one which contrasted beautiful vs. ugly sculptures as judged by each volunteer. The most striking result was that the observation of original sculptures, relative to the modified ones, produced activation of the right insula as well as of some lateral and medial cortical areas (lateral occipital gyrus, precuneus and prefrontal areas). The activation of the insula was particularly strong during the observation condition. Most interestingly, when volunteers were required to give an overt aesthetic judgment, the images judged as beautiful selectively activated the right amygdala, relative to those judged as ugly. We conclude that, in observers naïve to art criticism, the sense of beauty is mediated by two non-mutually exclusive processes: one based on a joint activation of sets of cortical neurons, triggered by parameters intrinsic to the stimuli, and the insula (objective beauty); the other based on the activation of the amygdala, driven by one's own emotional experiences (subjective beauty).

  3. ‘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.

  4. 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.

  5. Renaissance: A revolutionary approach for providing low-cost ground data systems

    Science.gov (United States)

    Butler, Madeline J.; Perkins, Dorothy C.; Zeigenfuss, Lawrence B.

    1996-01-01

    The NASA is changing its attention from large missions to a greater number of smaller missions with reduced development schedules and budgets. In relation to this, the Renaissance Mission Operations and Data Systems Directorate systems engineering process is presented. The aim of the Renaissance approach is to improve system performance, reduce cost and schedules and meet specific customer needs. The approach includes: the early involvement of the users to define the mission requirements and system architectures; the streamlining of management processes; the development of a flexible cost estimation capability, and the ability to insert technology. Renaissance-based systems demonstrate significant reuse of commercial off-the-shelf building blocks in an integrated system architecture.

  6. 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.

  7. Andreas Vesalius as a renaissance innovative neuroanatomist: his 5th centenary of birth.

    Science.gov (United States)

    Gomes, Marleide da Mota; Moscovici, Mauricio; Engelhardt, Eliasz

    2015-02-01

    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.

  8. 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.

  9. Realdo Colombo's "De Re Anatomica": the renaissance origin of the term "placenta" and its historical background.

    Science.gov (United States)

    Pizzi, M; Fassan, M; Cimino, M; Zanardo, V; Chiarelli, S

    2012-08-01

    Over the centuries, great interest has been devoted to the placenta and to its highly symbolic significance. The Renaissance represented the age of historical and cultural transition between classical and modern scientific paradigms. In the medical setting, Realdo Colombo represents one of the protagonists of this revolution. In his masterpiece, "De Re Anatomica", he revolutionized the former medical perspective. We present a passage from this book, which carries invaluable information on the Renaissance viewpoint on pregnancy and placental biology. The connections between Colombo's theories and the previous medical tradition are also analysed.

  10. 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

  11. 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

  12. The Making of the New Negro : Black Authorship, Masculinity, and Sexuality in the Harlem Renaissance

    NARCIS (Netherlands)

    Pochmara, Anna

    2011-01-01

    The Making of the New Negro onderzoekt zwarte mannelijkheid in de periode van de Harlem Renaissance, die lange tijd weinig wetenschappelijke aandacht trok, totdat in de jaren negentig veel geleerden ontdekten hoe complex, belangrijk en boeiend deze tijd was. Anna Pochmara maakt gebruik van Afro-Amer

  13. Art Appreciation, Farming, Measurement, Reading & Phonics, Renaissance: Daily Life, Sound & Light.

    Science.gov (United States)

    Web Feet, 2002

    2002-01-01

    This annotated subject guide to Web sites for grades K-8 focuses on art appreciation, farming, measurement, reading and phonics, renaissance daily life, sound and light, and calendar connections for June observances. Specific grade levels are indicated for each annotation. (LRW)

  14. 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…

  15. 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.

  16. 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.

  17. Chicago's Renaissance 2010: The Small Schools Movement Meets the Ownership Society

    Science.gov (United States)

    Ayers, William; Klonsky, Michael

    2006-01-01

    Would-be reformers need to beware of those who would co-opt the language of reform to undermine its ideals. Mr. Ayers and Mr. Klonsky examine how Chicago's Renaissance 2010 initiative has used the terms of the small schools movement to promote privatization and the erosion of public space. (Contains 5 endnotes.)

  18. WWC Review of the Report "Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report"

    Science.gov (United States)

    What Works Clearinghouse, 2012

    2012-01-01

    The study reviewed in this report examined the effects of Philadelphia's "Renaissance Schools Initiative" on students in K-8 schools after one year of implementation. Schools were selected for participation based on their School Performance Index (SPI) at the start of the 2010-11 school year. The SPI rates every school in Philadelphia from one to…

  19. 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…

  20. The New Saudi Educational Renaissance: In between the "Capacity to Aspire" and the "Capacity to Remember"

    Science.gov (United States)

    Pavan, Annalisa

    2014-01-01

    In the Kingdom of Saudi Arabia investments in higher education have increased exponentially in recent years, and the New Saudi Educational Renaissance is attracting the attention of international academia. The purpose of this study is to draw on Saudi sources, with the aim of allowing Saudi voices to introduce their strategies for the design of a…

  1. Origin of the cannula for tracheotomy during the middle ages and Renaissance.

    Science.gov (United States)

    Missori, Paolo; Brunetto, Giacoma M; Domenicucci, Maurizio

    2012-04-01

    The purpose of this article was to trace the historical origin of the inserted cannula during tracheotomy. Tracheotomy is mentioned in most ancient medical texts, but the origin of cannula insertion into the windpipe is unclear. We reviewed the incunabula and Renaissance texts reporting the utilization of surgical cannulas and tracheotomy. The incunabula disclosed extended use of surgical cannulas during the middle ages and Renaissance. Although tracheotomy was advocated in acutely suffocating patients for a disease of the throat termed squinantia or angina, the first report of the procedure was found only at the end of the middle ages and a second during the middle Renaissance. The introduction of cannula use in tracheotomy was supported by a semantic misinterpretation by Antonio Musa Brasavola. The historical origin for tracheotomy in the middle ages and Renaissance is conflicting. Antonio Brasavola wrongly interpreted Avicenna's oral cannula introduced into the windpipe for angina. This misinterpretation allowed Giulio Casserio to draw the first curved cannula introduced for used during tracheotomy.

  2. 76 FR 43349 - General Motors Corporation, Renaissance Center, including On-Site Leased Workers From Accretive...

    Science.gov (United States)

    2011-07-20

    ... the Federal Register on May 20, 2010 (75 FR 28299). The notice was amended on August 31, 2010 to... Register on September 13, 2010 (75 FR 55613-55614). At the request of the State agency, the Department... Employment and Training Administration General Motors Corporation, Renaissance Center, including...

  3. Liberty of Ideas: Renaissance Copia and the Nature of Free Thought.

    Science.gov (United States)

    Grudin, Robert

    1993-01-01

    Discusses the Renaissance idea of "copia," a rhetorical and literary term indicating enthralling richness in terms of detail, variation, and figures of speech, which might now be termed "copias thinking." Offers examples from Erasmus, Rabelais, Montaigne, and Shakespeare. Discusses the uses for copias thinking. (SR)

  4. 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

  5. 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

  6. 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)

  7. The Gaze of the Soul and of the Angel in the Renaissance Philosophy of Marsilio Ficino

    Directory of Open Access Journals (Sweden)

    Marko Uršič

    2015-04-01

    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.

  8. A facile environment-friendly one-pot two-step regioselective synthetic strategy for 3,7-diarylpyrazolo[1,5-a]pyrimidines related to zaleplon and 3,6-diarylpyrazolo[1,5-a]pyrimidine-7-amines assisted by KHSO[Formula: see text] in aqueous media.

    Science.gov (United States)

    Devi, Asem Satyapati; Kaping, Shunan; Vishwakarma, Jai Narain

    2015-11-01

    3-Aminopyrazoles required for the synthesis of pyrazolo[1,5-a]pyrimidines were obtained by the reaction of enaminonitriles with hydrazine hydrate. The resulting aminopyrazoles are reacted with formylated acetophenones under reflux at [Formula: see text] assisted by KHSO[Formula: see text] in aqueous media to form regioselectively 3,7-diarylpyrazolo[1,5-a]pyrimidines and 3,6-diarylpyrazolo[1,5-a]pyrimidine-7-amines. X-ray crystallography of selected compounds 5b and 7i further confirmed the regioselective formation of these products.

  9. 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

  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. A sociological view of the Russian religious renaissance at the end of the twentieth century: Its scope, limits and tendencies

    Directory of Open Access Journals (Sweden)

    Blagojević Mirko 1

    2004-01-01

    Full Text Available In this article I have dealt with empirical proofs for the Russian religious renaissance which came after the fall of the Soviet socialistic empire and carried on all through the nineties as a pro-religious (pro-orthodox consensus and a religious belief. Likewise, I have dealt with proofs suggesting certain limitations of the renaissance in question which manifested mainly in irregular fulfillment of religious duties.

  12. ‘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 ...

  13. 'Epidemic' of hand deformities in the French Renaissance paintings of Jean and François Clouet.

    Science.gov (United States)

    Weisz, G M; Albury, W R; Matucci-Cerinic, M; Lazzeri, D

    2016-09-01

    This article analyses the nature of the multiple finger anomalies found in portraits by the French Renaissance artistic dynasty, the Clouets. The multiplicity of finger anomalies could be either innocent congenital variants, or pathological and traumatic deformities. In view of the presence of such `beautifying variations' in the works of other Renaissance artists, the authors decided that these features were not the result of an epidemic of deformities, but instead represented a stylistic approach in paintings of this period at the French Court.

  14. 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.

  15. Application of PIXE to the study of Renaissance style enamelled gold jewelry

    Science.gov (United States)

    Weldon, M.; Carlson, J.; Reedy, S.; Swann, C. P.

    1996-04-01

    This study examines and compares three pieces of Renaissance style gold and enamelled jewelry owned by the Walters Art Gallery, Baltimore, MD, USA. These are a 16th century Hat Badge of Adam and Eve, a 19th century Fortitude Pendant and a Diana Pendant presumed to be of the 16th century (The Walters Art Gallery, Jewelry, Ancient to Modern (Viking, New York, 1979)), Ref. [1]. PIXE spectroscopy was applied to examine the elemental composition of the gold and of the enamels. Compositional differences, including the use of post-Renaissance colorants, were found between the enamels in separate regions of each of the three pieces. The modern colorant, chromium, was, in fact, found in all of the pieces and uranium was found in only the Diana Pendant. There are some differences in the gold purity of the three objects; there are significant differences in the solders used even within one object, the Fortitude Pendant.

  16. 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”’。

  17. Report from the field: Overview of the Sixth Annual Vaccine Renaissance Conference.

    Science.gov (United States)

    Spero, Denice; Levitz, Lauren; De Groot, Anne S

    2013-07-01

    The Sixth Annual Vaccine Renaissance Conference, hosted by the Institute for Immunology and Informatics (iCubed) at the University of Rhode Island (URI), took place on October 15-17, 2012. This conference provides a forum for the review of current progress in the discovery and development of vaccines, and creates an environment for the exchange of ideas. Dr. Joel McCleary opened the conference with a warning about the importance of preparing for well-defined biowarfare threats, including tularemia and Staphylococcal enterotoxin B. Following the keynote address, sessions explored biodefense and preparation for pandemic and biowarfare threats; vaccines for emerging and re-emerging neglected tropical diseases; animal vaccines and human health; and vaccine vectors and the human microbiome. In this issue of Human Vaccines and Immunotherapeutics, seven Vaccine Renaissance Conference speakers will showcase their work; here, we describe a few of the conference highlights.

  18. A classification of perceptual corrections of perspective distortions in renaissance painting.

    Science.gov (United States)

    Verstegen, Ian

    2010-01-01

    In an attempt to address major debates in perspective studies, this study brings perceptual research to bear on the problem of the status of perspective in the Renaissance. Between one school that sees perspective as mathematically rigorous but imperfectly applied and another that regards perspective as an incoherent discipline, this study argues that errors in the use of perspective are consistent and can be classified into two tendencies: first, the tendency to normalize a foreshortened form towards frontality and, second, the tendency to flatten a three-dimensional object to reveal its hidden sides. These tendencies find confirmation both in the Renaissance doctrine of the judgment of the eye (giudizio dell'occhio) as well as in Gestalt-oriented perceptual research. Numerous examples of their application are given with regard to the representation of human figures, architecture, and the relation of figures to space.

  19. 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".

  20. 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.

  1. Some Renaissance, Baroque, and contemporary cultural elaborations of the art of memory.

    Science.gov (United States)

    Bimler, David L

    2013-12-01

    The target article addresses historical and present-day mnemotechnics as a practice. It also deserves scrutiny as culture writ small. For would-be Hermetic adepts of the Renaissance and Baroque, the ancient art of memory (AAOM) provided both an iconography and a projective-test vision of possibilities. In contemporary fiction, Memory Palaces become a metaphor for the workings of mind, of culture, and of information technology. PMID:24304748

  2. Some Renaissance, Baroque, and contemporary cultural elaborations of the art of memory.

    Science.gov (United States)

    Bimler, David L

    2013-12-01

    The target article addresses historical and present-day mnemotechnics as a practice. It also deserves scrutiny as culture writ small. For would-be Hermetic adepts of the Renaissance and Baroque, the ancient art of memory (AAOM) provided both an iconography and a projective-test vision of possibilities. In contemporary fiction, Memory Palaces become a metaphor for the workings of mind, of culture, and of information technology.

  3. 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,...

  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 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 ...

  6. 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...

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. KINETICS OF NEUTRAL HYDROLYSIS OF 1-BENZOYL-3-PHENYL-1,2,4-TRIAZOLE IN HIGHLY AQUEOUS-MEDIA - ANALYSIS OF EFFECTS OF ADDED ETHANOL AND PROPAN-1-OL IN TERMS OF PAIRWISE GROUP-INTERACTION PARAMETERS

    NARCIS (Netherlands)

    BENAK, H; ENGBERTS, JBFN; BLANDAMER, MJ

    1992-01-01

    Over the range 288.15 less-than-or-equal-to T/K less-than-or-equal-to 333.15, the first-order rate constant for the neutral hydrolysis of 1-benzoyl-3-phenyl-1,2,4-triazole in aqueous solutions (pH ca. 4) decreases when either ethanol or propan-1-ol is added. The kinetic data are analysed in terms of

  13. Media violence.

    Science.gov (United States)

    Strasburger, V C

    1999-01-01

    For decades, media violence has been viewed as largely a Western problem. New studies indicate that Indian children have increasing access to the media and that media violence will subject them to the same problems as Western children: imitation, desensitization, fear, and inappropriate attitudes about violence and aggression. Solutions exist but will have to be implemented within the next decade to protect Indian children and adolescents from the harmful effects of media violence.

  14. 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

  15. 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

  16. 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

  17. 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 ...

  18. 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

  19. The Anonymous Plotter in the Routines of Renaissance Theatre and Drama

    OpenAIRE

    Paola Pugliatti

    2012-01-01

    Renaissance theatre, both in England and Italy, was a commercial enterprise and, therefore, it utilized procedures of division of labour to meet the challenge of the market. One of these procedures was the compilation of preparatory texts of various kinds. But, while about one thousand scenari of the commedia dell’arte (some anonymous, some with the author’s name) survive, of the ‘plots’ compiled by the English ‘plotters’ in preparation of plays to be written only one incomplete specimen and ...

  20. [Burn treatment in the renaissance by Fabricius Hildanus--a historical appraisal].

    Science.gov (United States)

    Rennekampff, H-O

    2009-12-01

    A first comprehensive textbook on burns treatment was written in 1607 by Fabry of Hilden (Fabricius Hildanus). This monograph describes cause, diagnosis, treatment, and complications of burn injuries. Besides a variety of topical ointments with promising herbal ingredients like onion and camphor, surgical procedures like necrectomies, escharotomies and syndactely treatment are described for the first time ever. Scar management including splinting devices is another interesting topic. Some of the therapeutic procedures are still valid today. Thus this renaissance piece of medical writing belongs to the pedigree of surgery. PMID:20017089

  1. 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

  2. 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....

  3. Marriage in Renaissance Drama: Defiance of Patriarchal Authority and Social Conventions

    Directory of Open Access Journals (Sweden)

    Ibrahim Abushihab

    2016-09-01

    Full Text Available This paper focuses on the miserable position of women and marriage issues in Renaissance drama. Women were generally considered as a threat to male authority. Girls did not have the right to choose their future husbands and were mostly obliged to marry men they did not like because their choice was based on the principles of the law and norms. Under these miserable conditions, some writers of the period strived to change the negative position of society and challenged the tyranny of male authority. In Elizabeth Cary’s  The Tragedy of Mariam  (1613  and  John Webster's The Duchess of Malfi (1612, Mariam and the Duchess reject the demands of  their society to be obedient, and raise voices to assert their selfhood.  Mariam decides to get rid of these restrictions by breaking the convention of the silent women and to challenge her husband’s authority, and that of her patriarchal society. On a parallel line, The Duchess attempts to deny the authority of social conventions and impose her identity in a patriarchal society. They are rebellious women who refuse to be under male authority and represent the contradictions of female identity in patriarchal cultures. They could not bear their humiliation in their society, and they want to lead a normal life without being controlled. Both die at the end and pay their lives for defying patriarchal authority and social conventions.Keywords: Feminism, Renaissance, Drama, Rebellious women 

  4. 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.

  5. The ReNAissanCe of mRNA-based cancer therapy.

    Science.gov (United States)

    Van Lint, Sandra; Renmans, Dries; Broos, Katrijn; Dewitte, Heleen; Lentacker, Ine; Heirman, Carlo; Breckpot, Karine; Thielemans, Kris

    2015-02-01

    About 25 years ago, mRNA became a tool of interest in anticancer vaccination approaches. However, due to its rapid degradation in situ, direct application of mRNA was confronted with considerable skepticism during its early use. Consequently, mRNA was for a long time mainly used for the ex vivo transfection of dendritic cells, professional antigen-presenting cells known to stimulate immunity. The interest in direct application of mRNA experienced a revival, as researchers became aware of the many advantages mRNA offers. Today, mRNA is considered to be an ideal vehicle for the induction of strong immune responses against cancer. The growing numbers of preclinical trials and as a consequence the increasing clinical application of mRNA as an off-the-shelf anticancer vaccine signifies a renaissance for transcript-based antitumor therapy. In this review, we highlight this renaissance using a timeline providing all milestones in the application of mRNA for anticancer vaccination.

  6. [Brief history of lead poisoning: from Egyptian civilization to the Renaissance].

    Science.gov (United States)

    Robles-Osorio, María Ludivina; Sabath, Ernesto

    2014-01-01

    The exposition to lead in the Antiquity is one of the first environmental health risks in the history of the mankind. In the ancient cultures of Egypt, Crete and Sumer there was no reports of an important exposition to this metal. The first clinical data is described in the Corpus Hipocraticcus, however was Nicandrus of Colophon the first to make a thorough description of the clinical manifestations of this disease. There was an increase in the exposition to this metal in times of the Roman empire and even some researchers propose that Julius Cesar and Octavio had clinical manifestations associated with lead poisoning. Paul of Aegina in the 7th century (a.C.) describes the first epidemic associated with lead intoxication, however in the Middle Ages the use of lead decrease until the Renaissance period in which lead poisoning affects mostly painters, metal-smithers and miners. Some studies done in the ice-layers of Greenland showed that the environmental pollution by lead during the Roman empire and the Renaissance was important.

  7. The Metaphysic of Encounter of Space at the Meet of Persian Miniature with Renaissance Painting

    Directory of Open Access Journals (Sweden)

    abdollah aghaie

    2015-03-01

    Full Text Available Persian miniature was showing itself as dynamic during dialogue with “other” visual traditions (Specially Eastern ones. But it seems that meet renaissance painting was a kind of “encounter” to a strange matter for it. The most substantial part of this encounter is incompatibility of whose perception of space. Since that the conception of space is related to basic principle of representation. What this paper has focused on, is “the reason” of this encounter. With the help of philosophical approach this paper is trying to answer the question. So is to shed light on metaphysics foundation that make possible rise of conception of space in both side. By using the conception of “the mathematical” in Heidegger philosophy, it is shown that how ascend of modern metaphysic was lead to quantitative perception of space in renaissance painting, and at the other hand how using a qualitative perception of space in Persian miniature opposing to modern perspective of space.

  8. 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.

  9. 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.

  10. 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.

  11. Bioreversible Derivatives of Phenol. 1. The Role of Human Serum Albumin as Related to the Stability and Binding Properties of Carbonate Esters with Fatty Acid-like Structures in Aqueous Solution and Biological Media

    Directory of Open Access Journals (Sweden)

    Claus Larsen

    2007-10-01

    Full Text Available With the overall objective of assessing the potential of utilizing plasma protein binding interactions in combination with the prodrug approach for improving the pharmacokinetics of drug substances, a series of model carbonate ester prodrugs of phenol, encompassing derivatives with fatty acid-like structures, were characterized in vitro. Stability of the derivatives was studied in aqueous solution, human serum albumin solution, human plasma, and rat liver homogenate at 37°C. Stability of the derivatives in aqueous solution varied widely, with half-lives ranging from 31 to 1.7 × 104 min at pH 7.4 and 37°C. The carbonate esters were subject to catalysis by plasma esterases except for the t-butyl and acetic acid derivatives, which were stabilized in both human plasma and human serum albumin solutions relative to buffer. In most cases, however, hydrolysis was accelerated in the presence of human serum albumin indicating that the derivatives interacted with the protein, a finding which was confirmed using the p-nitrophenyl acetate kinetic assay. Different human serum albumin binding properties of the phenol model prodrugs with fatty acid-like structure and neutral carbonate esters were observed. In the context of utilizing plasma protein binding in combination with the prodrug approach for optimizing drug pharmacokinetics, the esterase-like properties of human serum albumin towards the carbonate esters potentially allowing the protein to act as a catalyst of parent compound regenerations is interesting.

  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. 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...

  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. 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…

  16. 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.

  17. 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…

  18. 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

  19. "Renaissance Man"

    Science.gov (United States)

    Smith, Susan

    2012-01-01

    A photo gallery of noteworthy graduates stretches across two walls in the office of the Community College Leadership Program, or CCLP, at the University of Texas at Austin. Dr. John Roueche, the director of CCLP, points to the photos with pride, listing the accomplishments of his former students. Scanning the portraits, one of his greatest…

  20. 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,

  1. 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

  2. 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...

  3. Raman spectroscopic study of “The Malatesta”: A Renaissance painting?

    Science.gov (United States)

    Edwards, Howell G. M.; Vandenabeele, Peter; Benoy, Timothy J.

    2015-02-01

    Raman spectroscopic analysis of the pigments on an Italian painting described as a "Full Length Portrait of a Gentleman", known also as the "Malatesta", and attributed to the Renaissance period has established that these are consistent with the historical research provenance undertaken earlier. Evidence is found for the early 19th Century addition of chrome yellow to highlighted yellow ochre areas in comparison with a similar painting executed in 1801 by Sir Thomas Lawrence of John Kemble in the role of Hamlet, Prince of Denmark. The Raman data are novel in that no analytical studies have previously been made on this painting and reinforces the procedure whereby scientific analyses are accompanied by parallel historical research.

  4. Ulisse Aldrovandi's Pandechion epistemonicon and the use of paper technology in Renaissance natural history.

    Science.gov (United States)

    Kraemer, Fabian

    2014-01-01

    Reconstructing the formation and use of the hitherto neglected Pandechion epistemonicon, Ulisse Aldrovandi's (152-1605) extant manuscript encyclopaedia, this article shows that early modern naturalists in many ways shared a world of paper with the members of several other professions. An analysis of the Pandechion suggests that Renaissance naturalists who applied the humanist jack-of-all-trades, the commonplace book, in their own field sometimes considerably altered its form. Aldrovandi tested and recombined different techniques so as to arrive at the paper technology that he considered to be the most fit for his purposes. He thereby drew on administrative practices as well as on the bookkeeping practices of early modern merchants that he knew first-hand.

  5. 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'.

  6. "Being the world eternal ..." the age of the Earth in Renaissance Italy.

    Science.gov (United States)

    Dal Prete, Ivano

    2014-06-01

    Scholarship on the early modern period assumes that the Creation story of Genesis and its chronology were the only narratives openly available in Renaissance Europe. This essay revisits the topic by exploring a wide range of literature on the age and nature of the Earth in early modern Italy. It suggests that, contrary to received notions, in the early 1500s an Aristotelian ancient world characterized by slow geological change was a common assumption in discourse on the Earth. These notions were freely disseminated by popularizations and didactic literature in the vernacular, which made them available to a large readership. Counter-Reformation cultural policies eventually called for a tighter integration of theology and natural philosophy; however, the essay argues that even then the creation of the world was usually placed in a remote and undetermined past, not necessarily tied to the short timescales of contemporary chronology.

  7. 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’.

  8. Heavenly Networks. Celestial Maps and Globes in Circulation between Artisans, Mathematicians, and Noblemen in Renaissance Europe.

    Science.gov (United States)

    Gessner, Samuel

    2015-01-01

    The aim of this paper is to examine the iconography on a set of star charts by Albrecht Dürer (1515), and celestial globes by Caspar Vopel (1536) and Christoph Schissler (1575). The iconography on these instruments is conditioned by strong traditions which include not only the imagery on globes and planispheres (star charts), but also ancient literature about the constellations. Where this iconography departs from those traditions, the change had to do with humanism in the sixteenth century. This "humanistic" dimension is interwoven with other concerns that involve both "social" and "technical" motivations. The interplay of these three dimensions illustrates how the iconography on celestial charts and globes expresses some features of the shared knowledge and shared culture between artisans, mathematicians, and nobles in Renaissance Europe.

  9. 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 ...

  10. "Being the world eternal ..." the age of the Earth in Renaissance Italy.

    Science.gov (United States)

    Dal Prete, Ivano

    2014-06-01

    Scholarship on the early modern period assumes that the Creation story of Genesis and its chronology were the only narratives openly available in Renaissance Europe. This essay revisits the topic by exploring a wide range of literature on the age and nature of the Earth in early modern Italy. It suggests that, contrary to received notions, in the early 1500s an Aristotelian ancient world characterized by slow geological change was a common assumption in discourse on the Earth. These notions were freely disseminated by popularizations and didactic literature in the vernacular, which made them available to a large readership. Counter-Reformation cultural policies eventually called for a tighter integration of theology and natural philosophy; however, the essay argues that even then the creation of the world was usually placed in a remote and undetermined past, not necessarily tied to the short timescales of contemporary chronology. PMID:25154134

  11. The influences of the hurly-burly renaissance world in the formation of camonian thematics

    Directory of Open Access Journals (Sweden)

    Paulo Rogério souza

    2015-04-01

    Full Text Available Current article proposes a reading of poetic texts produced by Camões based on his experience as a man of the Renaissance. Luíz Vaz de Camões (1524-1580 experienced the social conflicts brought about by structural and organizational changes in 16th century Portuguese society, which developed into world confusion. Such an experience may be observed in Rhymes and in the epic poem The Lusiads with different themes. It reveals a man divided between contradictory feelings and social conflicts experienced at that historical moment. The selected poems and the historical-biographical references on the poet produce the hurly-burly world immortalized in his verses and in the great changes of the 16th century.

  12. 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.

  13. 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.

  14. Magnetically Separable Fe3O4@DOPA-Pd: A Heterogeneous Catalyst for Aqueous Heck Reaction

    Science.gov (United States)

    Magnetically separable Fe3O4@DOPA-Pd catalyst has been synthesized via anchoring of palladium over dopamine-coated magnetite via non-covalent interaction and the catalyst is utilized for expeditious Heck coupling in aqueous media.

  15. 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.

  16. 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

  17. 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

  18. 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…

  19. 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...

  20. The Scholarship of Teaching and Learning (SoTL) at Renaissance College (University of New Brunswick): A Case Study of SoTL at the Faculty Level

    Science.gov (United States)

    Mengel, Thomas

    2016-01-01

    This chapter presents the case study of Renaissance College at the University of New Brunswick, discussing the faculty's achievements, challenges, and outlook for the future in the context of the scholarship of teaching and learning in Canada.

  1. 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

  2. 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.

  3. Synthesis of New Conductive Polyaniline Aqueous Dispersion and its Electroactivity in Alkline Media%新型水溶性导电聚苯胺的合成及其在碱性条件下电化学行为研究

    Institute of Scientific and Technical Information of China (English)

    张玉梅; 曹菊琴; 刘建平; 张逢源

    2011-01-01

    以含短链亲水基团的酸性磷酸酯为掺杂剂合成新型导电聚苯胺纳米水分散液,通过透射电子显微镜、循环伏安法对其形貌和电化学性能进行表征。研究表明:合成的聚苯胺为直径20-80nm且均匀分散的球状粒子;分散液在碱性介质中仍保持较好的电化学活性及稳定性。该研究为水溶性导电聚苯胺在抗腐蚀等碱性环境中的应用提供了更广阔的思路。%Nanoscale conductive polyaniline aqueous dispersion was prepared by acidic phosphate ester with a short hydrophilic unit as a dopant and characterized by Transmission Electron Microscope and Cylic Voltammograms. The results showed that spherical particles of polyaniline were distributed uniformly and the size ranged from 20 nm to 80 nm. In addition, electrochemical activity of the conductive polymer dispersion was still kept in alkaline media and it displayed an excellent stability upon cycling. The investigation broadens fields of prospective application of conductive polyaniline in alkaline solution such as anticorrosion.

  4. 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.

  5. 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/

  6. 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

  7. 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…

  8. 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.

  9. Modeling of aqueous foam blast wave attenuation

    Science.gov (United States)

    Del Prete, E.; Chinnayya, A.; Hadjadj, A.; Domergue, L.; Haas, J.-F.; Imbert, B.

    The use of aqueous foams enables the mitigation of blast waves induced by the explosion of energetic materials. The two-phase confinement gives rise to interphase interactions between the gaseous and liquid phases, which role have been emphasized in shock-tube studies with solid foams [1, 2]. Multifluid formalism enables the thermo-mechanical disequilibria between phases to be taken into account. The flow model ensures the correct estimation of the acoustic impedance of the two-phase media. As for the numerical scheme, Riemann solvers are used to describe the microscopic fluid interactions, the summation of which provides the multiphase flux. The role of the different transfer mechanisms is evaluated in the case where the liquid ligaments of the foam matrix have been shattered into droplets by the shock impingement. Characteristics of blast waves in heterogeneous media leads to a decrease of overpressure. The numerical results have been compared favorably to experimental data [3, 4].

  10. The Renaissance Kidney-Nephrology in and about the Sixteenth Century.

    Science.gov (United States)

    Eknoyan, Garabed

    2012-07-01

    The endeavor to understand the workings of the human body is as old as civilization; but it is in the intellectual movement of the Renaissance that its actual scientific study began in earnest and has not ceased growing since then. It was in the 16th century that the study of organs was launched and with it that of the kidney, which was then conceived as an accessory organ to clear the excess water ingested with food. The study of the structural basis of kidney function was launched by Bartolomeo Eustachio (1514-1574); the elements of its physiology and pathology were promulgated by Jean Fernel (1497-1558), and that of the chemical study of urine and of the principal cause of kidney disease then, calculi, instigated by Joan Baptista Van Helmont (1577-1644). The methodological approaches of these and their contemporary investigators, which were crystallized and formulated by Francis Bacon (1561-1626), opened the gates of the Scientific Revolution that followed in the 17th century, beginning with that of describing the circulation in 1628 by William Harvey (1564-1657) that would finally free the kidney from the shackles imposed on it as a mere accessory organ to the liver in Galen's physiology.

  11. An Assessment of Reservoir Filling Policies under a Changing Climate for Ethiopia's Grand Renaissance Dam

    Science.gov (United States)

    King, A.; Block, P. J.

    2012-12-01

    Climate variability and change cause unsteady hydrologic response, commonly experienced through varying river flows. These variations affect the performance and reliability of water resources dependent systems, including domestic, agriculture, energy, and the environment, with economic implications. Long-term design and operation of these systems is therefore inherently uncertain, producing copious risks at time-scales of months to decades. Yet evaluation of system performance under non-stationary climate conditions is typically ignored. Here we demonstrate the potential performance of Ethiopia's forthcoming Grand Renaissance hydropower dam on the Blue Nile River, subject to coincident climate change and reservoir filling policies. Presently, no agreed-upon reservoir retention policy exists between Ethiopia and downstream countries, even though construction has already begun. We will present a tool designed to allow users to select expected future climate conditions and reservoir filling rates, from a stochastic perspective. Additionally, the maximum reservoir volume may also be varied. Major outputs include hydropower generation and downstream flow for use by policy-makers. Ethiopia's desire to rapidly expand hydropower dams on the Nile constitutes an enormous financial investment and latent risk, with further implications on streamflow reduction to Sudan and Egypt, and a need for multi-national energy contracts, necessitating proper advanced planning.

  12. 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.

  13. 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.

  14. 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.

  15. 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.)

  16. The renaissance of bacillosamine and its derivatives: pathway characterization and implications in pathogenicity.

    Science.gov (United States)

    Morrison, Michael J; Imperiali, Barbara

    2014-02-01

    Prokaryote-specific sugars, including N,N'-diacetylbacillosamine (diNAcBac) and pseudaminic acid, have experienced a renaissance in the past decade because of their discovery in glycans related to microbial pathogenicity. DiNAcBac is found at the reducing end of oligosaccharides of N- and O-linked bacterial protein glycosylation pathways of Gram-negative pathogens, including Campylobacter jejuni and Neisseria gonorrhoeae. Further derivatization of diNAcBac results in the nonulosonic acid known as legionaminic acid, which was first characterized in the O-antigen of the lipopolysaccharide (LPS) in Legionella pneumophila. Pseudaminic acid, an isomer of legionaminic acid, is also important in pathogenic bacteria such as Helicobacter pylori because of its occurrence in O-linked glycosylation of flagellin proteins, which plays an important role in flagellar assembly and motility. Here, we present recent advances in the characterization of the biosynthetic pathways leading to these highly modified sugars and investigation of the roles that each plays in bacterial fitness and pathogenicity.

  17. A RAS renaissance: emerging targeted therapies for KRAS-mutated non-small cell lung cancer.

    Science.gov (United States)

    Vasan, Neil; Boyer, Julie L; Herbst, Roy S

    2014-08-01

    Of the numerous oncogenes implicated in human cancer, the most common and perhaps the most elusive to target pharmacologically is RAS. Since the discovery of RAS in the 1960s, numerous studies have elucidated the mechanism of activity, regulation, and intracellular trafficking of the RAS gene products, and of its regulatory pathways. These pathways yielded druggable targets, such as farnesyltransferase, during the 1980s to 1990s. Unfortunately, early clinical trials investigating farnesyltransferase inhibitors yielded disappointing results, and subsequent interest by pharmaceutical companies in targeting RAS waned. However, recent advances including the identification of novel regulatory enzymes (e.g., Rce1, Icmt, Pdeδ), siRNA-based synthetic lethality screens, and fragment-based small-molecule screens, have resulted in a "Ras renaissance," signified by new Ras and Ras pathway-targeted therapies that have led to new clinical trials of patients with Ras-driven cancers. This review gives an overview of KRas signaling pathways with an emphasis on novel targets and targeted therapies, using non-small cell lung cancer as a case example.

  18. Probing the Ultraviolet Luminosity Function of the Earliest Galaxies with the Renaissance Simulations

    Science.gov (United States)

    O'Shea, Brian W.; Wise, John H.; Xu, Hao; Norman, Michael L.

    2015-07-01

    In this paper, we present the first results from the Renaissance Simulations, a suite of extremely high-resolution and physics-rich AMR calculations of high-redshift galaxy formation performed on the Blue Waters supercomputer. These simulations contain hundreds of well-resolved galaxies at z˜ 25-8, and make several novel, testable predictions. Most critically, we show that the ultraviolet luminosity function of our simulated galaxies is consistent with observations of high-z galaxy populations at the bright end of the luminosity function ({M}1600≤slant -17), but at lower luminosities is essentially flat rather than rising steeply, as has been inferred by Schechter function fits to high-z observations, and has a clearly defined lower limit in UV luminosity. This behavior of the luminosity function is due to two factors: (i) the strong dependence of the star formation rate (SFR) on halo virial mass in our simulated galaxy population, with lower-mass halos having systematically lower SFRs and thus lower UV luminosities; and (ii) the fact that halos with virial masses below ≃ 2× {10}8 {M}⊙ do not universally contain stars, with the fraction of halos containing stars dropping to zero at ≃ 7× {10}6 {M}⊙ . Finally, we show that the brightest of our simulated galaxies may be visible to current and future ultra-deep space-based surveys, particularly if lensed regions are chosen for observation.

  19. Historical perspective of traditional indigenous medical practices: the current renaissance and conservation of herbal resources.

    Science.gov (United States)

    Pan, Si-Yuan; Litscher, Gerhard; Gao, Si-Hua; Zhou, Shu-Feng; Yu, Zhi-Ling; Chen, Hou-Qi; Zhang, Shuo-Feng; Tang, Min-Ke; Sun, Jian-Ning; Ko, Kam-Ming

    2014-01-01

    In recent years, increasing numbers of people have been choosing herbal medicines or products to improve their health conditions, either alone or in combination with others. Herbs are staging a comeback and herbal "renaissance" occurs all over the world. According to the World Health Organization, 75% of the world's populations are using herbs for basic healthcare needs. Since the dawn of mankind, in fact, the use of herbs/plants has offered an effective medicine for the treatment of illnesses. Moreover, many conventional/pharmaceutical drugs are derived directly from both nature and traditional remedies distributed around the world. Up to now, the practice of herbal medicine entails the use of more than 53,000 species, and a number of these are facing the threat of extinction due to overexploitation. This paper aims to provide a review of the history and status quo of Chinese, Indian, and Arabic herbal medicines in terms of their significant contribution to the health promotion in present-day over-populated and aging societies. Attention will be focused on the depletion of plant resources on earth in meeting the increasing demand for herbs.

  20. 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 ...