Sample records for aqueous media renaissance

  1. Interfacial forces in aqueous media

    CERN Document Server

    van Oss, Carel J


    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 New in this Edition: Four previously unpublished chapters comprising a new section on interfacial propertie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. Photophysics of silicon phthalocyanines in aqueous media. (United States)

    Doane, Tennyson L; Chuang, Chi-Hung; Chomas, Andrew; Burda, Clemens


    Phthalocyanines have been used as photodynamic therapy (PDT) agents because of their uniquely favorable optical properties and high photostability. They have been shown to be highly successful for the treatment of cancer through efficient singlet-oxygen ((1)O(2)) production. However, due to their hydrophobic properties, the considerations of solubility and cellular location have made understanding their photophysics in vitro and in vivo difficult. Indeed, many quantitative assessments of PDT reagents are undertaken in purely organic solvents, presenting challenges for interpreting observations during practical application in vivo. With steady-state and time-resolved laser spectroscopy, we show that for axial ligated silicon phthalocyanines in aqueous media, both the water:lipophile ratio and the pH have drastic effects on their photophysics, and ultimately dictate their functionality as PDT drugs. We suggest that considering the presented photophysics for PDT drugs in aqueous solutions leads to guidelines for a next generation of even more potent PDT agents.

  3. Recycled Renaissance (United States)

    Armstrong, Wendy


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

  4. Investigation of aqueous stability of taxol in different release media. (United States)

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


    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.

  5. Medical Renaissance. (United States)

    Toledo-Pereyra, Luis H


    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.

  6. Chemical Stability of Laponite in Aqueous Media



    In this work stability of Laponite against dissolution in its aqueous dispersions is investigated as a function of initial pH of water before mixing Laponite, and concentration of Laponite. Dissolution of Laponite is quantified in terms of concentration of leached magnesium in the dispersions. Interestingly the solvent pH is observed to play no role in dissolution of Laponite in dispersion over the explored range of 3 to 10. Furthermore, contrary to the usual belief that Laponite dissolves wh...

  7. Aqueous Media Oxidation of Alcohols with Ammonium Persulfate

    Institute of Scientific and Technical Information of China (English)

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


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

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

    DEFF Research Database (Denmark)

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


    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...

  9. Rare Earth Elements in Global Aqueous Media (United States)

    Noack, C.; Karamalidis, A.; Dzombak, D. A.


    We are examining the occurrence and abundance of rare earth elements (REE) associated with produced waters from shale gas development, and factors controlling aqueous REE concentrations in geochemical environments, to provide information for: (1) potential recovery of REE as a valuable byproduct, and (2) utilization of unique REE signatures as a risk assessment tool. REE include the lanthanide series of elements - excluding short-lived, radioactive promethium - and yttrium. These elements are critical to a wide variety of high-tech, energy efficient applications such as phosphors, magnets, and batteries. Escalating costs of REE resulting from divergent supply and demand patterns motivates the first goal. The second goal relates to the search for a reliable, naturally occurring tracer to improve understanding of fluid migration and water-rock interactions during hydraulic fracturing and natural gas recovery. We compiled data from 100 studies of REE occurrence and concentrations in groundwaters, ocean waters, river waters, and lake waters. In the groundwater systems documented, total dissolved REE concentrations ranged over eight orders of magnitude; however the average concentrations across the lanthanides varied by less than two orders of magnitude. This leads to exceptional inter-element correlations, with a median correlation coefficient greater than 0.98, implying potential usefulness of REE ratios for groundwater signatures. Reports describing reactions governing REE solubilization were also investigated. We assembled information about important solution chemistries and performed equilibrium modeling using PHREEQC to examine common hypotheses regarding the factors controlling REE compositions. In particular, effects of pH, Eh, and common complexing ligands were evaluated. Produced and connate waters of the Marcellus shale are well characterized for their major chemical elements. There is a dearth of knowledge, however, regarding the occurrence of REE in

  10. Carbonated aqueous media for quench heat treatment of steels (United States)

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


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

    KAUST Repository

    Polshettiwar, Vivek


    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.

  12. 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


    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.

  13. Towards water compatible MIPs for sensing in aqueous media. (United States)

    Horemans, F; Weustenraed, A; Spivak, D; Cleij, T J


    When synthesizing molecularly imprinted polymers (MIPs), a few fundamental principles should be kept in mind. There is a strong correlation between porogen polarity, MIP microenvironment polarity and the imprinting effect itself. The combination of these parameters eventually determines the overall binding behavior of a MIP in a given solvent. In addition, it is shown that MIP binding is strongly influenced by the polarity of the rebinding solvent. Because the use of MIPs in biomedical environments is of considerable interest, it is important that these MIPs perform well in aqueous media. In this article, various approaches are explored towards a water compatible MIP for the target molecule l-nicotine. To this end, the imprinting effect together with the MIP matrix polarity is fine-tuned during MIP synthesis. The binding behavior of the resulting MIPs is evaluated by performing batch rebinding experiments that makes it possible to select the most suitable MIP/non-imprinted polymer couple for future application in aqueous environments. One method to achieve improved compatibility with water is referred to as porogen tuning, in which porogens of varying polarities are used. It is demonstrated that, especially when multiple porogens are mixed, this approach can lead to superior performance in aqueous environments. Another method involves the incorporation of polar or non-polar comonomers in the MIP matrix. It is shown that by carefully selecting these monomers, it is also possible to obtain MIPs, which can selectively bind their target in water.

  14. Cation exchange properties of zeolites in hyper alkaline aqueous media. (United States)

    Van Tendeloo, Leen; de Blochouse, Benny; Dom, Dirk; Vancluysen, Jacqueline; Snellings, Ruben; Martens, Johan A; Kirschhock, Christine E A; Maes, André; Breynaert, Eric


    Construction of multibarrier concrete based waste disposal sites and management of alkaline mine drainage water requires cation exchangers combining excellent sorption properties with a high stability and predictable performance in hyper alkaline media. Though highly selective organic cation exchange resins have been developed for most pollutants, they can serve as a growth medium for bacterial proliferation, impairing their long-term stability and introducing unpredictable parameters into the evolution of the system. Zeolites represent a family of inorganic cation exchangers, which naturally occur in hyper alkaline conditions and cannot serve as an electron donor or carbon source for microbial proliferation. Despite their successful application as industrial cation exchangers under near neutral conditions, their performance in hyper alkaline, saline water remains highly undocumented. Using Cs(+) as a benchmark element, this study aims to assess the long-term cation exchange performance of zeolites in concrete derived aqueous solutions. Comparison of their exchange properties in alkaline media with data obtained in near neutral solutions demonstrated that the cation exchange selectivity remains unaffected by the increased hydroxyl concentration; the cation exchange capacity did however show an unexpected increase in hyper alkaline media.

  15. Thermodynamic Modelling of Dolomite Behavior in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Tadeusz Michałowski


    Full Text Available The compact thermodynamic approach to the systems containing calcium, magnesium, and carbonate species is referred to dissolution of dolomite, as an example of nonequilibrium ternary salt when introduced into aqueous media. The study of dolomite is based on all attainable physicochemical knowledge, involved in expressions for equilibrium constants, where the species of the system are interrelated. The species are also involved in charge and concentration balances, considered as constraints put on a closed system, separated from the environment by diathermal walls. The inferences are gained from calculations performed with use of an iterative computer program. The simulated quasistatic processes occurred under isothermal conditions, started at a preassumed pH0 value of the solution where dolomite was introduced, and are usually involved with formation of other solid phases. None simplifying assumptions in the calculations were made.

  16. 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)


    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.

  17. Teologie en Renaissance

    Directory of Open Access Journals (Sweden)

    J. H. van Wyk


    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.

  18. Environmental Consequences of Nanotechnologies: Nanoparticle Dispersion in Aqueous Media: SOP-T-1 (United States)


    ER D C/ EL S R- 15 -2 Environmental Consequences of Nanotechnologies Nanoparticle Dispersion in Aqueous Media: SOP-T-1 En vi ro nm en...dispersions of nanoparticles (NPs) for use in bioassay media for exposures/characterizations are a crucial need in ecotoxicology assays. The present...protocol provides guidance and step-by-step methods for: (1) creating a working stock from nanoparticle powder and nanoparticle aqueous suspensions

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

    Directory of Open Access Journals (Sweden)

    Camilo A. Navarro D.


    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.

  20. Novel Syntheses of Aryl and Benzyl Selenides Promted by Metallic Zinc in Aqueous Media

    Institute of Scientific and Technical Information of China (English)


    @@ Introduction Recently, organometallic-type of reactions in aqueous media have attracted a considerable interest in organic syntheses[1-4]. The main advantage of making organometallic reactions in strictly anhydrous organic solvents took place in aqueous media is the ease of the reactions so as to obviate the need for inflammable anhydrous organic solvents and troublesome inert atmosphere. For some reactions, e.g., the alkylations of the carbonyl group in carbohydrates didnt need to be altered to take place in organic solvents[5]. The most commonly used metals are zinc, tin and indium[1-4].

  1. The Renaissance Teacher

    DEFF Research Database (Denmark)

    Hansen, Per Skafte


    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....

  2. Removal of amitriptyline from aqueous media using activated carbons


    Valente Nabais, Joao; Ledesma, Beatriz; Laginhas, Carlos


    This paper reports the removal of amitriptyline, a widely used tricyclic anti-depressant, from aqueous solutions by six activated carbons produced from cork, coffee endocarp and eucalyptus pulp. The results of this study showed that samples from cork and eucalyptus pulp, activated at 800 °C, exhibited the highest adsorption capacity of 120 mg/g and 110 mg/g, respectively. Samples produced from coffee endocarp showed the lowest capacity. Amitriptyline adsorption was almost in...

  3. 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.


    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.

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

    KAUST Repository

    Zhang, L.


    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.

  5. Specific acid catalysis and Lewis acid catalysis of Diels-Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, E.B.; Engberts, J.B.F.N.


    A comparative study of specific acid catalysis and Lewis acid catalysis of Diells-Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas hy

  6. Specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, Egid B.; Engberts, Jan B.F.N.


    A comparative study of specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas hyd

  7. Derivatization in gas chromatographic determination of phenol and aniline traces in aqueous media (United States)

    Gruzdev, I. V.; Zenkevich, I. G.; Kondratenok, B. M.


    Substituted anilines and phenols are the most common hydrophilic organic environmental toxicants. The principles of gas chromatographic determination of trace amounts of these compounds in aqueous media at concentrations extractive preconcentration and selective chromatographic detection. Among the known reactions, this condition is best met by electrophilic halogenation of compounds at the aromatic moiety. The bibliography includes 177 references.

  8. Calculation of Hamaker constants in non-aqueous fluid media

    Energy Technology Data Exchange (ETDEWEB)



    Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces.

  9. Terahertz characteristics of electrolytes in aqueous Luria-Bertani media (United States)

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


    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.

  10. Bioremediation techniques applied to aqueous media contaminated with mercury. (United States)

    Velásquez-Riaño, Möritz; Benavides-Otaya, Holman D


    In recent years, the environmental and human health impacts of mercury contamination have driven the search for alternative, eco-efficient techniques different from the traditional physicochemical methods for treating this metal. One of these alternative processes is bioremediation. A comprehensive analysis of the different variables that can affect this process is presented. It focuses on determining the effectiveness of different techniques of bioremediation, with a specific consideration of three variables: the removal percentage, time needed for bioremediation and initial concentration of mercury to be treated in an aqueous medium.

  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


    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. (United States)

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


    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.

  13. The Metadiscourse of Renaissance Humanism

    DEFF Research Database (Denmark)


    The case studies in this volume explore the Renaissance humanists' metadiscourse on translation, letter writing, Biblical criticism, poetry, and Latin grammar and composition. Especially, the papers examine the role played by metadiscourse in the dissemination of Renaissance humanism, and how...

  14. Social Research On Renaissance Period

    Institute of Scientific and Technical Information of China (English)



    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.

  15. The Ionian Renaissance and Alexandria

    DEFF Research Database (Denmark)

    Pedersen, Poul


    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 (United States)

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


    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

  17. A soil science renaissance

    NARCIS (Netherlands)

    Hartemink, A.E.


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

  18. Stabilities and partitioning of arenonium ions in aqueous media. (United States)

    Lawlor, D A; More O'Ferrall, R A; Rao, S N


    The phenathrenonium ion is formed as a reactive intermediate in the solvolysis of 9-dichloroacetoxy-9,10-dihydrophenanthrene in aqueous acetonitrile and undergoes competing reactions with water acting as a base and nucleophile. Measurements of product ratios in the presence of azide ion as a trap and 'clock' yield rate constants kp = 3.7 x 10(10) and kH2O = 1.5 x 10(8) s(-1), respectively. Combining these with rate constants for the reverse reactions (protonation of phenanthrene and acid-catalyzed aromatization of its water adduct) gives equilibrium constants pKa = -20.9 and pK(R) = -11.6. For a series of arenonium and benzylic cations, correlation of log kp with pKa, taking account of the limit to kp set by the relaxation of water (10(11) s(-1)), leads to extrapolation of kp = 9.0 x 10(10) s(-1) and pKa = -24.5 for the benzenonium ion and kp = 6.5 x 10(10) s(-1) and pKa = -22.5 for the 1-naphthalenonium ion. Combining these pKa's with estimates of equilibrium constants pKH2O for the hydration of benzene and naphthalene, and the relationship pKR = pKa + pKH2O based on Hess's law, gives pKR = -2.3 and -8.0 respectively, and highlights the inherent stability of the benzenonium ion. A correlation exists between the partitioning ratio, kp/kH2O, for carbocations reacting in water and KH2O the equilibrium constant between the respective reaction products, i.e., log(kp/kH2O) = 0.46pKH2O - 3.7. It implies that kp exceeds kH2O only when KH2O > 10(8). This is consistent with the proton transfer (a) possessing a lower intrinsic reactivity than reaction of the carbocation with water as a nucleophile and (b) being rate-determining in the hydration of alkenes (and dehydration of alcohols) except when the double bond of the alkene is unusually stabilized, as in the case of aromatic molecules.

  19. 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


    @@ 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

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

    KAUST Repository

    Khan, Hadayat Ullah


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

  2. 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


    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.

  3. Antioxidant activity of propyl gallate in aqueous and lipid media: a theoretical study. (United States)

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


    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.

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

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

    Directory of Open Access Journals (Sweden)

    Moses Wazingwa Munthali


    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.

  6. 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


    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.

  7. Role of solvent properties of aqueous media in macromolecular crowding effects. (United States)

    Ferreira, Luisa A; Madeira, Pedro P; Breydo, Leonid; Reichardt, Christian; Uversky, Vladimir N; Zaslavsky, Boris Y


    Analysis of the macromolecular crowding effects in polymer solutions show that the excluded volume effect is not the only factor affecting the behavior of biomolecules in a crowded environment. The observed inconsistencies are commonly explained by the so-called soft interactions, such as electrostatic, hydrophobic, and van der Waals interactions, between the crowding agent and the protein, in addition to the hard nonspecific steric interactions. We suggest that the changes in the solvent properties of aqueous media induced by the crowding agents may be the root of these "soft" interactions. To check this hypothesis, the solvatochromic comparison method was used to determine the solvent dipolarity/polarizability, hydrogen-bond donor acidity, and hydrogen-bond acceptor basicity of aqueous solutions of different polymers (dextran, poly(ethylene glycol), Ficoll, Ucon, and polyvinylpyrrolidone) with the polymer concentration up to 40% typically used as crowding agents. Polymer-induced changes in these features were found to be polymer type and concentration specific, and, in case of polyethylene glycol (PEG), molecular mass specific. Similarly sized polymers PEG and Ucon producing different changes in the solvent properties of water in their solutions induced morphologically different α-synuclein aggregates. It is shown that the crowding effects of some polymers on protein refolding and stability reported in the literature can be quantitatively described in terms of the established solvent features of the media in these polymers solutions. These results indicate that the crowding agents do induce changes in solvent properties of aqueous media in crowded environment. Therefore, these changes should be taken into account for crowding effect analysis.

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

    Crochet, Pascale; Cadierno, Victorio


    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.

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

    KAUST Repository

    Polshettiwar, Vivek


    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.

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

    Indian Academy of Sciences (India)

    J Lalitham; V R Vijayaraghavan


    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.

  11. Renaissance Learning Equating Study. Report (United States)

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


    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.…

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

    Directory of Open Access Journals (Sweden)

    Rui Liu


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

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

    Directory of Open Access Journals (Sweden)

    Daniela Dascălu


    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.

  14. Comparison of homogeneous and heterogeneous catalysts for glucose-to-fructose isomerization in aqueous media. (United States)

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


    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.

  15. Calix[4]arene based dipodal receptor nanohybrids for selective determination of chloride ions in aqueous media. (United States)

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


    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.

  16. Speciation of phytate ion in aqueous solution. Alkali metal complex formation in different ionic media. (United States)

    De Stefano, Concetta; Milea, Demetrio; Pettignano, Alberto; Sammartano, Silvio


    The acid-base properties of phytic acid [ myo-inositol 1,2,3,4,5,6-hexakis(dihydrogen phosphate)] (H(12)Phy; Phy(12-)=phytate anion) were studied in aqueous solution by potentiometric measurements ([H+]-glass electrode) in lithium and potassium chloride aqueous media at different ionic strengths (0iodide (Et(4)NI; e.g., at I=0.5 mol L(-1), log K(3)(H)=11.7, 8.0, 9.1, and 9.1 in Et(4)NI, LiCl, NaCl and KCl, respectively; the protonation constants in Et(4)NI and NaCl were already reported), owing to the strong interactions occurring between the phytate and alkaline cations present in the background salt. We explained this in terms of complex formation between phytate and alkali metal ions. Experimental evidence allows us to consider the formation of 13 mixed proton-metal-ligand complexes, M(j)H(i)Phy((12-i-j)-), (M+ =Li+, Na+, K+), with jstability of alkali metal complexes follows the trend Li+ > or =Na+K+. Some measurements were also performed at constant ionic strength (I=0.5 mol L(-1)), using different mixtures of Et(4)NI and alkali metal chlorides, in order to confirm the formation of hypothesized and calculated metal-proton-ligand complex species and to obtain conditional protonation constants in these multi-component ionic media.

  17. Electrodiffusion of molecules in aqueous media: a robust, discretized description for electroporation and other transport phenomena. (United States)

    Smith, Kyle C; Weaver, James C


    Electrically driven transport of molecules and ions within aqueous electrolytes is of long-standing interest, with direct relevance to applications that include the delivery/release of biologically active solutes to/from cells and tissues. Examples include iontophoretic and electroporation-mediated drug delivery. Here, we describe a robust method for characterizing electrodiffusive transport in physiologic aqueous media. Specifically, we treat the case of solute present in sufficiently low concentration as to negligibly contribute to the total ionic current within the system. In this limiting case, which applies to many systems of interest, the predominant electrical behavior due to small ions is decoupled from solute transport. Thus, electrical behavior may be characterized using existing methods and treated as known in characterizing electrodiffusive molecular transport. First, we present traditional continuum equations governing electrodiffusion of charged solutes within aqueous electrolytes and then adapt them to discretized systems. Second, we examine the time-dependent and steady-state interfacial concentration gradients that result from the combination of diffusion and electrical drift. Third, we show how interfacial concentration gradients are related to electric field strength and duration. Finally, we examine how discretization size affects the accuracy of these methods. Overall these methods are motivated by and well suited to addressing an outstanding goal: estimation of the net ionic and molecular transport facilitated by electroporation in biological systems.

  18. Graphene oxide as filter media to remove levofloxacin and lead from aqueous solution. (United States)

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


    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.

  19. Kinetics of naphthalene adsorption on an activated carbon: comparison between aqueous and organic media. (United States)

    Cabal, B; Ania, C O; Parra, J B; Pis, J J


    The purpose of this work was to explore the kinetics of naphthalene adsorption on an activated carbon from aqueous and organic solutions. Kinetic curves were fitted to different theoretical models, and the results have been discussed in terms of the nature and properties of the solvents, the affinity of naphthalene to the solutions, and the accessibility to the porosity of the activated carbon. Data was fitted to the pseudo-second order kinetic model with good correlation coefficients for all the solution media. The faster adsorption rate was obtained for the most hydrophobic solvent (heptane). The overall adsorption rate of naphthalene seems to be controlled simultaneously by external (boundary layer) followed by intraparticle diffusion in the porosity of the activated carbon when water, ethanol and cyclohexane are used as solvents. In the case of heptane, only two stages were observed (pore diffusion and equilibrium) suggesting that the limiting stage is the intraparticle diffusion. The low value of the boundary thickness supports this observation.

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

    Directory of Open Access Journals (Sweden)

    Sylvain Ballandras


    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.

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

    Institute of Scientific and Technical Information of China (English)


    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.

  2. 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


    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.

  3. 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.


    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.

  4. Microorganisms form exocellular structures, trophosomes, to facilitate biodegradation of oil in aqueous media. (United States)

    Dmitriev, Vladimir V; Crowley, David; Rogachevsky, Vadim V; Negri, Cristina Maria; Rusakova, Tatiana G; Kolesnikova, Svetlana A; Akhmetov, Lenar I


    Cytochemical staining and microscopy were used to study the trophic structures and cellular morphotypes that are produced during the colonization of oil-water interfaces by oil-degrading yeasts and bacteria. Among the microorganisms studied here, the yeasts (Schwanniomyces occidentalis, Torulopsis candida, Candida tropicalis, Candida lipolytica, Candida maltosa, Candida paralipolytica) and two representative bacteria (Rhodococcus sp. and Pseudomonas putida) produced exocellular structures composed of biopolymers during growth on petroleum hydrocarbons. Four of the yeasts including S. occidentalis, T. candida, C. tropicalis and C. maltosa excreted polymers through modified sites in their cell wall ('canals'), whereas C. lipolytica and C. paralipolytica and the two bacterial species secreted polymers over the entire cell surface. These polymers took the form of fibrils and films that clogged pores and cavities on the surfaces of the oil droplets. A three-dimensional reconstruction of the cavities using serial thin sections showed that the exopolymer films isolated the ambient aqueous medium together with microbial cells and oil to form both closed and open granules that contained pools of oxidative enzymes utilized for the degradation of the oil hydrocarbons. The formation of such granules, or 'trophosomes,' appears to be a fundamental process that facilitates the efficient degradation of oil in aqueous media.

  5. Development of a correlation for aqueous-vapor phase mass transfer in porous media (United States)

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


    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.

  6. Regioselective Propargylation of Aldehydes with Propargyl Bromide Mediated by Sn-In in Aqueous Media under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    Cheng Zhi GU; Qian Rong LI; Hao YIN


    Tin-indium were employed in the propargylations of various aldehydes with propargyl bromide in the presence of SnCl2 and C6 H5(CH3)3NBr under microwave irradiation to afford the corresponding homopropargyl alcohols exclusively in high yields. All the reactions were completed smoothly in predominantly aqueous media in 200 seconds only.

  7. 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


    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.

  8. β-Cyclodextrin as a Metal-anionic Porphyrin Complexation Accelerator in Aqueous Media. (United States)

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


    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.

  9. 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


    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

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

    Indian Academy of Sciences (India)

    Sankaran Anuradha; Venkatapuram Ramanujam Vijayaraghavan


    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.

  11. Controlled release of the pineal hormone melatonin from hydroxypropylmethylcellulose/sodium alginate matrices in aqueous media containing dioctyl sulfosuccinate. (United States)

    Vlachou, Marilena; Tsiakoulia, Athanasia; Eikosipentaki, Aphrodite


    An investigation of the controlled release profile of mono-layered formulations of the hormone melatonin in modified aqueous media is described. The tablets used were comprised of hydroxypropylmethylcellulose (HPMC K15M) and sodium alginate with melatonin (fully soluble in the dioctyl sulfosuccinate (DSS) containing simulated intestinal solution). Three different sets of tablets (diameters 7.5, 10.0 and 13.0 mm) were tested with respect to the influence of their sizes on the hormone's release; the general trend observed was that tablets with larger surface area values had lower % release. A decrease in the value of W(o), obtained from the ratio [H(2)O]/[DSS], results to the predominance of DSS conformers in the aqueous media, which are less likely to solubilize melatonin effectively.

  12. 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


    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.

  13. 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


    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.

  14. The Resonance of Renaissance Poetry. (United States)

    Greenblatt, Stephen


    Discusses reading and teaching Renaissance poetry in terms of the poem's "resonance," its capacity to speak to contemporary readers directly and draw them into its historical world. Advises teachers to expand the resonance to illuminate the poem's background, as exemplified by the poetry of Thomas Wyatt in the court of Henry VIII. (DF)

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

  16. 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


    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.

  17. Does excited-state proton-transfer reaction contribute to the emission behaviour of 4-aminophthalimide in aqueous media? (United States)

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


    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.

  18. Lipase in biphasic alginate beads as a biocatalyst for esterification of butyric acid and butanol in aqueous media. (United States)

    Ng, Choong Hey; Yang, Kun-Lin


    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.

  19. Selective detection of Cu(2+) and Co(2+) in aqueous media: Asymmetric chemosensors, crystal structure and spectroscopic studies. (United States)

    Dogaheh, Samira Gholizadeh; Khanmohammadi, Hamid; Carolina Sañudo, E


    Two new azo-azomethine receptors, H2L(1) and H2L(2), containing hydrazine, naphthalene and different electron withdrawing groups, Cl and NO2, have been designed and synthesized for qualitative and quantitative detection of Cu(2+) and Co(2+) in aqueous media. The crystal structure of H2L(1)is reported. The H2L(1)was used as a chemosensor for selective detection of trace amount of Cu(2+) in aqueous media. H2L(2) was also applied to naked-eye distinction of Cu(2+) and Co(2+) from other transition metal ions in aqueous media. Detection limit of Cu(2+) is 1.13μM and 1.26μM, in water, for H2L(1) and H2L(2), respectively, which are lower than the World Health Organization (WHO) recommended level. The binuclear Cu(2+) and Co(2+) complexes of the receptors have been also prepared and characterized using spectroscopic methods and MALDI-TOF mass analysis. Furthermore, the binding stoichiometry between the receptors upon the addition Cu(2+) and Co(2+) has been investigated using Job's plot. Moreover, the fluorescence emission spectra of the receptors and their metal complexes are also reported.

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

    Rosan, Reviewed Alan M.


    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

  1. "Reactive" optical sensor for Hg(2+) and its application in environmental aqueous media and biological systems. (United States)

    Chen, Zhi; Chen, Jiayun; Pan, Dong; Li, Hongwei; Yao, Yunhui; Lyu, Zu; Yang, Liting; Ma, Li-Jun


    A new rhodamine B-based "reactive" optical sensor (1) for Hg(2+) was synthesized. Sensor 1 shows a unique colorimetric and fluorescent "turn-on" selectivity to Hg(2+) over 14 other metal ions with a hypersensitivity (detection limits are 27.6 nM (5.5 ppb) and 6.9 nM (1.4 ppb), respectively) in neutral buffer solution. To test its applicability in the environment, sensor 1 was applied to quantify and visualize low levels of Hg(2+) in tap water and river water samples. The results indicate sensor 1 is a highly sensitive fluorescent sensor for Hg(2+) with a detection limit of 1.7 ppb in tap water and river water. Moreover, sensor 1 is a convenient visualizing sensor for low levels of Hg(2+) (0.1 ppm) in water environment (from colorless to light pink). In addition, sensor 1 shows good potential as a fluorescent visualizing sensor for Hg(2+) in fetal bovine serum and living 293T cells. The results indicate that sensor 1 shows good potential as a highly sensitive sensor for the detection of Hg(2+) in environmental and biological samples. Graphical Abstract A new rhodamine B-based "reactive" optical sensor (1) for Hg(2+) was synthesized. 1 shows a unique colorimetric and fluorescent "turn-on" selectivity to Hg(2+) over 14 other metal ions with a hypersensitivity in water environment. And it is a convenient visualizing probe for low levels of Hg(2+) in environment aqueous media, fetal bovine serum and living 293T cells.

  2. 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)


    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.

  3. 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.


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guoxiang; Zheng, Zuoping; Wan, Jiamin


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

  5. Renaissance Neurosurgery: Italy's Iconic Contributions. (United States)

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


    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.

  6. The Renaissance Conception Regarding Technology

    Directory of Open Access Journals (Sweden)

    Robert Arnăutu


    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.

  7. Improvement of extraction capability of magnetic molecularly imprinted polymer beads in aqueous media via dual-phase solvent system. (United States)

    Hu, Yuling; Liu, Ruijin; Zhang, Yi; Li, Gongke


    In this study, a novel and simple dual-phase solvent system for the improvement of extraction capability of magnetic molecularly imprinted polymer (MIP) beads in aqueous sample was proposed. The method integrated MIP extraction and micro-liquid-liquid extraction (micro-LLE) into only one step. A magnetic MIP beads using atrazine as template was synthesized, and was applied to aqueous media by adding micro-volume of n-hexane to form a co-extraction system. The magnetic MIP beads preferred to suspend in the organic phase, which shielded them from the disturbance of water molecule. The target analytes in the water sample was extracted into the organic phase by micro-LLE and then further bound to the solid-phase of magnetic MIP beads. The beads specificity was significantly improved with the imprinting efficiency of template increasing from 0.5 to 4.4, as compared with that in pure aqueous media. The extraction capacity, equilibration process and cross-selectivity of the MIP dual-phase solvent extraction system were investigated. The proposed method coupled with high-performance liquid chromatography was applied to the analysis of atrazine, simazine, propazine, simetryn, prometryne, ametryn and terbutryn in complicated sample such as tomato, strawberry juice and milk. The method is selective, sensitive and low organic solvent-consuming, and has potential to broaden the range of MIP application in biological and environmental sample.

  8. 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.


    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Alan M. Shipley


    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

  10. Brain 'imaging' in the Renaissance. (United States)

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


    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. 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


    @@ 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

  12. 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


    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.

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

    Directory of Open Access Journals (Sweden)

    Ricochon Guillaume


    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.

  14. Selective separation of copper(II) and nickel(II) from aqueous media using the complexation-ultrafiltration process. (United States)

    Molinari, Raffaele; Poerio, Teresa; Argurio, Pietro


    The polyethylenimine (PEI) as complexing agent was used to study the complexation-ultrafiltration (CP-UF) process in the selective removal of Cu(II) from Ni(II) contained in aqueous media. Preliminary tests showed that optimal chemical conditions for Cu(II) and Ni(II) complexation by the PEI polymer were pH>6.0 and 8.0, respectively, and polymer/metal weight ratio of 3.0 and 6.0, respectively. The effect of some important operating parameters on process selectivity was studied by performing UF tests at different parameters: pH, polymer/metal weight ratio, transmembrane pressure (TMP), and membrane cut-off in a batch experimental set-up. It was observed that process selectivity was achieved by choosing the pH value for obtaining a preferential copper complexation (pH 6.0), and the polymer/metal ratio needed to bound only the copper ion (3.0). The selective separation by UF tests was performed by using both a laboratory aqueous solution and a real aqueous effluent (water from Emoli torrent, Rende (CS)). The Iris 30 membrane at TMP of 200 kPa (2 bar) for both aqueous media gave the best results. A complete nickel recovery was reached, and copper recovery was the highest for this membrane (94% and 92%). Besides at this pressure, a lower water amount was needed to obtain total nickel recovery by diafiltration. A little higher membrane fouling was obtained by using the river effluent due to the presence of dissolved organic and inorganic matter.

  15. The Kinetic Aspects of the Interaction of Nitrite Ions with Sulfanilic Acid and 1-Naphthylamine in Aqueous and Micellar Media (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  17. 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


    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.

  18. Halloysite nanotube with fluorinated lumen: non-foaming nanocontainer for storage and controlled release of oxygen in aqueous media. (United States)

    Cavallaro, Giuseppe; Lazzara, Giuseppe; Milioto, Stefana; Palmisano, Giovanni; Parisi, Filippo


    Halloysite clay nanotubes were selectivity modified by adsorbing perfluoroalkylated anionic surfactants at the inner surface. The modified nanotubes formed kinetically stable dispersions due to the enhanced electrostatic repulsions exercised between the particles. We proved that the modified nanotubes can be used as non-foaming oxygen nanocontainers in aqueous media. The gas release from supersaturated dispersions can be controlled by external stimuli and system composition. In conclusion, we managed to put forward an easy strategy to develop smart materials from natural nanoclays, which can endow important applications like the storage and delivery of gas.

  19. Olefin Metathesis in Homogeneous Aqueous Media Catalyzed by Conventional Ruthenium Catalysts (United States)

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


    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

  20. 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


    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.

  1. 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)


    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.

  2. 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


    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.

  3. Airship Renaissance: Considerations for Operational Warfare (United States)


    FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Airship Renaissance : Considerations for Operational Warfare 5a. CONTRACT...Airship Renaissance : Considerations for Operational Warfare by Daniel W. Smith III Major, United States Air Force A paper submitted...resources needed now on the battlefield…to get more intelligence, surveillance, and reconnaissance assets into the theatre .” 5 Recognizing budget

  4. The Harlem Renaissance in Black and White. (United States)

    Hutchinson, George

    Intended to expose the oversimplifications and misrepresentations of popular readings of the Harlem Renaissance, this book reveals the truly composite nature of American literary culture. Noting that a broader sense of the intellectual context of the Harlem Renaissance has been missing from literary histories, the book supplies an appreciation of…

  5. 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)


    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

  6. The renaissance of developmental biology. (United States)

    St Johnston, Daniel


    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.

  7. Nuclear power renaissance or demise?

    Energy Technology Data Exchange (ETDEWEB)

    Dossani, Umair


    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.

  8. Transport of cerium oxide nanoparticles in saturated silica media: influences of operational parameters and aqueous chemical conditions (United States)

    Zhang, Zhaohan; Gao, Peng; Qiu, Ye; Liu, Guohong; Feng, Yujie; Wiesner, Mark


    This paper aimed to investigate the influences of operational parameters and aqueous chemical conditions on transport behaviors of cerium oxides nanoparticles (CeO2-NPs) in saturated silica media. Results indicated that increasing rates of attachment efficiency (α) were related with cationic types, and critical deposition concentration (CDC) for divalent cation (Ca2+ and Mg2+) were more than 31-fold of that for monovalent cation (Na+ and K+). Increase or reduction of electrolyte pH could both promote the mobility of CeO2-NPs in glass beads, while influence was more evident at alkaline conditions. α increased linearly with NPs concentrations, while decreased linearly with flow velocity in the column, and effects were related with electrolyte contents. Presence of surfactants could sharply decreased α, and SDS was more effective to facilitate CeO2-NPs transport than Triton X-100. With DOMs concentrations increasing, α firstly kept constant, then sharply declined, and finally reduced very slowly. The influence of DOMs on NPs deposition was in order of SA > HA > TA >  BSA. Overall, this study revealed that aqueous chemical conditions was crucial to NPs transport in porous media, and would provide significant information for our understanding on the fate and transport of nanoparticles in natural environment.

  9. Impact of polymers on the crystallization and phase transition kinetics of amorphous nifedipine during dissolution in aqueous media. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  11. 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


    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.

  12. In vitro degradation of natural insoluble lignin in aqueous media by the extracellular peroxidases of Phanerochaete chrysosporium

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.N.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States); Hames, B.R. [National Renewable Energy Lab., Golden, CO (United States). Biomass Analysis Group; Grethlein, H.E. [Michigan State Univ., East Lansing, MI (United States)]|[Michigan Biotechnology Inst., Lansing, MI (United States)


    The lignin peroxidases (LIP) and manganese peroxidases (MNP) of Phanerochaete chrysosporium catalyze a wide range of lignin depolymerization reactions with lignin models and synthetic lignins in solution. However, their ability to degrade insoluble natural lignin in aqueous media has not been demonstrated. Insoluble isolated poplar lignin similar to natural lignin was treated in vitro in aqueous media for 12 h with LIP, MNP, and both. Treatment with MNP alone slightly increased the solid mass and produced measurable amounts of lignin-derived 2,6-dimethoxyhydroquinone and 2-methoxyhydroquinone but did not appreciably decrease the total lignin content. Treatment with LIP alone did not decrease the mass but produced measurable amounts of lignin-derived p-hydroxybenzoic acid and slightly decreased the lignin content. Finally, treatment with LIP and MNP together decreased the solid mass by 11%, decreased the lignin content by 5%, and released low-concentration compounds with mass spectra containing the typical lignin-derived electron-impact fragments of mass 107, 137, 151, 167, and 181. These results suggest that MNP increases the effectiveness of LIP-mediated lignin degradation.

  13. A novel double-layer molecularly imprinted polymer film based surface plasmon resonance for determination of testosterone in aqueous media (United States)

    Tan, Yuan; Jing, Lijing; Ding, Yonghong; Wei, Tianxin


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

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


    Basch, Angelika; Strnad, Simona


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

  15. Dithiooxamide Modified Glassy Carbon Electrode for the Studies of Non-Aqueous Media: Electrochemical Behaviors of Quercetin on the Electrode Surface

    Directory of Open Access Journals (Sweden)

    Ecir Yılmaz


    Full Text Available Electrochemical oxidation of quercetin, as an important biological molecule, has been studied in non-aqueous media using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. To investigate the electrochemical properties of quercetin, an important flavonoid derivative, on a different surface, a new glassy carbon electrode has been developed using dithiooxamide as modifier in non-aqueous media. The surface modification of glassy carbon electrode has been performed within the 0.0 mV and +800 mV potential range with 20 cycles using 1 mM dithioxamide solution in acetonitrile. However, the modification of quercetin to both bare glassy carbon and dithiooxamide modified glassy carbon electrode surface was carried out in a wide +300 mV and +2,800 mV potential range with 10 cycles. Following the modification process, cyclic voltammetry has been used for the surface characterization in aqueous and non-aqueous media whereas electrochemical impedance spectroscopy has been used in aqueous media. Scanning electron microscopy has also been used to support the surface analysis. The obtained data from the characterization and modification studies of dithioxamide modified and quercetin grafted glassy carbon electrode showed that the developed electrode can be used for the quantitative determination of quercetin and antioxidant capacity determination as a chemical sensor electrode.

  16. Impact of ionic strength on Cd(II) partitioning between alginate gel and Aqueous media

    NARCIS (Netherlands)

    Kalis, E.J.J.; Davis, T.A.; Town, R.M.; Leeuwen, van H.P.


    Alginate gel is representative of polysaccharide-based components of cell walls which contain a large number of negatively charged functional groups. The structural charge gives rise to a Donnan potential in the gel, which impacts significantly on the partitioning of ions between the aqueous medium

  17. Dissolution and Protection of Aluminium Oxide in Corrosive Aqueous Media - An Ellipsometry and Reflectometry Study

    NARCIS (Netherlands)

    Karlsson, P.M.; Postmus, B.R.; Palmqvist, A.E.C.


    Dissolution of alumina has been studied from wafers in aqueous solution by means of ellipsometry and reflectometry. It was discovered that the dissolution of aluminium oxide is promoted by ethanol amines like N,N-bis(2-hydroxyethyl)glycine and triethanolamine, and that this dissolution is retarded b


    Institute of Scientific and Technical Information of China (English)

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


    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.

  19. Characterization of Oxidation Product Films on Lead in Aqueous Media by In Situ Raman Spectroscopy (United States)


    to an aqueous exposure, one of three different methods was used: 1) immersion in dilute nitric acid solution for five miuutes to dissolve the surface...coated with beeswax to allow only a measured area -’A or the sample to come in contact with the solution. The coi=nection between the copper wire and the...before introduction of the sample, the slution was stirred and purged of reactive dissolved gdsses by bubbling nitrogen throuqh it. The gas purge and

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

    Institute of Scientific and Technical Information of China (English)


    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.

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


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


    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), ...

  2. Manipulation of cellulose nanocrystal surface sulfate groups toward biomimetic nanostructures in aqueous media. (United States)

    Zoppe, Justin O; Johansson, Leena-Sisko; Seppälä, Jukka


    We report a facile aqueous procedure to create multivalent displays of sulfonated ligands on CNCs for future applications as viral inhibitors. CNCs were decorated with model compounds containing sulfonate groups via reactions of epoxides and isothiocyanates with amines under alkaline conditions. At first, surface sulfate groups of CNCs were hydrolytically cleaved by alkaline hydrolysis to increase the number of available surface hydroxyls. Success of desulfation was confirmed via dynamic light scattering (DLS), zeta potential measurements and thermogravimetric analysis (TGA). CNC surface hydroxyl groups were then activated with epichlorohydrin before subsequent reactions. As proof of concept toward aqueous pathways for functionalizing nanoparticles with sulfonated ligands, 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt hydrate (CPSA) and 4-sulfophenyl isothiocyanate sodium salt monohydrate (4-SPITC) were chosen as model compounds to react with homobifunctional 2,2'-(ethylenedioxy)bis(ethylamine) (EBEA) molecular spacer. The approaches presented are not only applicable to polysaccharide nanocrystals, but also other classes of polymeric and inorganic substrates presenting surface hydroxyl groups, as in the case of poly(2-hydroxyethyl methacrylate) (PHEMA), silica or glass. CNCs carrying sulfonated ligands were characterized by ATR-FTIR and UV-vis spectroscopy. Surface chemical compositions of desired elements were determined via X-ray photoelectron spectroscopy (XPS). We anticipate that with these facile aqueous procedures as the proof of concept, a diverse library of target-specific functionalities can be conjugated to CNCs for applications in nanomedicine, especially related to viral inhibition.

  3. 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


    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.

  4. One pot four component sequential synthesis of hexahydroquinoline derivatives in aqueous media via enaminone intermediates: A green protocol

    Directory of Open Access Journals (Sweden)

    D. Patil


    Full Text Available A convenient green chemistry method through one pot four component tandem synthesis of hexahydroquinoline via enaminone intermediate using dimedone, ammonium acetate, aryl aldehydes and malononitrile has been described in aqueous media without the use of any external catalyst. The excess of ammonium acetate used acts as a reagent as well as catalyst. The incorporation of water as solvent along with eradication of external catalyst renders the protocol to comply with the green chemistry aspects. Shorter reaction time, high atom economy, easy work up and purification of products by non-chromatographic method are the crucial features of this methodology. The crystal structure of hexahydroquinoline basically shaped by chromatographic free selective reaction was determined by single crystal X-ray diffraction analysis.

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

    DEFF Research Database (Denmark)

    Rolle, Massimo


    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...... advection-dominated flow through conditions. When the solutes are charged species, besides the magnitude of their aqueous diffusion coefficients also their electrostatic interactions play a significant role in the displacement of the different species. Under flow-through conditions this leads...... to 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...

  6. A facile approach for cupric ion detection in aqueous media using polyethyleneimine/PMMA core-shell fluorescent nanoparticles (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yuan; Jing, Lijing; Ding, Yonghong; Wei, Tianxin, E-mail:


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

  8. Amine-functionalized, multi-arm star polymers: A novel platform for removing glyphosate from aqueous media. (United States)

    Samuel, Lianna; Wang, Ran; Dubois, Geraud; Allen, Robert; Wojtecki, Rudy; La, Young-Hye


    We describe a novel method for efficiently removing glyphosate from aqueous media via adsorption onto highly functionalized star-shaped polymeric particles. These particles have a polystyrene core with more than 35 attached methacrylate polymer arms, each containing a plurality of pendant amines (poly(dimethylamino ethyl methacrylate): PDMAEMA) that are partially protonated in water. Kinetic studies demonstrate that these star-polymers successfully remove up to 93% of glyphosate present in aqueous solution (feed concentration: 5 ppm), within 10 min contact time, outperforming activated carbon, which removed 33% after 20 min. On these star-polymers, glyphosate adsorption closely follows the Langmuir model indicating monolayer coverage at most. Ionic interaction between the protonated amines and glyphosate's dissociated carboxylic and phosphoric acid groups lead to effective glyphosate capture even at feed concentrations below 1 ppm. Surface charge of these star polymers and dissociation of glyphosate are both influenced by pH, thus glyphosate removal efficiency increases from 63% to 93% when pH increases from 4.2 to 7.7. NMR studies conducted with butylamine as a proxy for these polymeric particles confirm that the amine group binds with both glyphosate's carboxylic and phosphoric acid groups when its concentrations are in a 2:1 or higher molar ratio with glyphosate.


    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  10. Evoliution of Castle Palaces in Lithuanian Renaissance

    Directory of Open Access Journals (Sweden)

    Inga Genytė


    Full Text Available The article author examines the problem of architecture history associated with the evolution of castle palaces in the current territory of Lithuania in the Lithuanian Renaissance period. The article is based on research papers thematically close to the publication, other literature and archive documents. After prehistory review of castle palaces at a theoretical level and clarifying the conditions for their occurrence, significant development trends of castle palaces during the Renaissance period in current Lithuania territory is revealed. At the beginning of the sixteenth century, Italian, Flemish and Flanders Renaissance reached Lithuania and merged with the local tradition; in the light of the Lithuanian Renaissance castle palaces reached their prosperity period in Lithuania. Castle palaces were distinguished by the diversity of their structural and architectural forms, relatively meaningful connection between function and artistic expression and a sustainable link with the components of environment.Article in Lithuanian

  11. 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)


    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.

  12. High chemiluminescence activity of an Fe(III)-TAML activator in aqueous-organic media and its use in the determination of organic peroxides. (United States)

    Demiyanova, Alexandra S; Sakharov, Ivan Yu


    High activity of Fe(III)-TAML, peroxidase mimic, upon the catalytic oxidation of luminol in aqueous-organic media (ethanol, isopropanol and acetonitrile) was determined. Using Fe(III)-TAML the sensitive chemiluminescence assays for the determination of benzoyl peroxide and tert-butyl hydroperoxide in the presence of organic solvents were performed.


    Direct synthesis of 4,5-dihydro-pyrazole, pyrazolidine, and 1,2-dihydro-phthalazine derivatives via double alkylation of hydrazines by alkyl dihalides or ditosylates were accomplished in aqueous media under microwave irradiation conditions; the environmentally friendlier chemical...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kyzas, George Z. [Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Koltsakidou, Anastasia [Laboratory of Environmental Pollution Control, Department of Chemistry, Aristotle University of Thessaloniki, GR–541 24 Thessaloniki (Greece); Nanaki, Stavroula G.; 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: [Laboratory of Environmental Pollution Control, Department of Chemistry, Aristotle University of Thessaloniki, GR–541 24 Thessaloniki (Greece)


    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 (pH 2–10) and organic solvents. - Highlights: • Removal of beta-blockers by graphene oxide (GhO) from aqueous samples • Detailed adsorbent characterization and adsorption studies • Kinetic studies are performed and adsorption isotherms are determined and modeled. • GhO was proved to be an effective adsorbent for removal of atenolol and propranolol.

  15. Optimization of the electrochemical pre-concentration of trivalent lanthanum from aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Jamie L. [Washington State Univ., Pullman, WA (United States). Chemistry Dept.; Clark, Sue B. [Washington State Univ., Pullman, WA (United States). Chemistry Dept.; Pacific Northwest National Laboratory, Richland, WA (United States)


    Electrochemical pre-concentration has been shown to effectively increase sample sensitivity and decrease processing time; however, the basic mechanism and optimal conditions of the technique remain unknown, specifically for lanthanides. To gain a better understanding of the mechanism of action, the aqueous solution conditions required to maximize the electrochemical pre-concentration of lanthanum (La) were studied. Parameters investigated included pH, applied potential, and ionic strength. To further optimize and elucidate the mechanism of lanthanide pre-concentration, specific interactions of lanthanum with the mercury film electrode were studied. Three possible mechanisms were proposed based on preliminary observations, including ligand bridging, hydroxide formation, and amalgamation.

  16. Effect of buffer on heparin binding and sensing in competitive aqueous media


    Chan, Ching Wan; Smith, David K.


    Although buffer-specific effects on molecular recognition are known in biological science, they remain rare in supramolecular chemistry. The binding between a cationic dye, Mallard Blue (MalB), and polyanionic heparin in aqueous NaCl (150 mM) is studied in three commonly-used buffers (Tris-HCl, HEPES, Phosphate, each 10 mM). Although MalB has a very similar UV-Vis spectrum in each buffer, the sensory response towards heparin was different in each case. This can be ascribed to differences in t...

  17. Mesoporous silica functionalized with 1-furoyl thiourea urea for Hg(II) adsorption from aqueous media. (United States)

    Mureseanu, Mihaela; Reiss, Aurora; Cioatera, Nicoleta; Trandafir, Ion; Hulea, Vasile


    New organic-inorganic hybrid materials were prepared by covalently anchoring 1-furoyl thiourea on mesoporous silica (SBA-15). By means of various characterization techniques (X-ray diffraction, nitrogen adsorption-desorption, thermogravimetric analysis, and FTIR spectroscopy) it has been established that the organic groups were successfully anchored on the SBA-15 surfaces and the ordering of the inorganic support was preserved during the chemical modifications. The hybrid sorbents exhibited good ability to remove Hg(II) from aqueous solution. Thus, at pH 6, the adsorption capacity of mercury ions reached 0.61 mmol g(-1).

  18. 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


    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.

  19. Evidence for organic synthesis in high temperature aqueous media - facts and prognosis (United States)

    Simoneit, Bernd R. T.


    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.

  20. Responses of polar organic compounds to different ionic environments in aqueous media are interrelated. (United States)

    Ferreira, L A; Chervenak, A; Placko, S; Kestranek, A; Madeira, P P; Zaslavsky, B Y


    Solubilities of 17 polar organic compounds in aqueous solutions of Na2SO4, NaCl, NaClO4, and NaSCN at the salt concentrations of up to 1.0-2.0 M were determined and the Setschenow constant, ksalt, values were estimated. It was found that NaClO4 may display both salting-in and salting-out effects depending on the particular compound structure. The Setschenow constant values for all the polar compounds examined in different salt solutions are found to be interrelated. Similar relationships were observed for partition coefficients of nonionic organic compounds in aqueous polyethylene glycol-sodium sulfate two-phase systems in the presence of different salt additives reported previously [Ferreira et al., J. Chromatogr. A, 2011, 1218, 5031], and for the effects of different salts on optical rotation of amino acids reported by Rossi et al. [J. Phys. Chem. B, 2007, 111, 10510]. In order to explain the observed relationships it is suggested that all the effects observed originate as responses of the compounds to the presence of a given ionic environment and its interaction with the compounds by forming direct or solvent-separated ionic pairs. The response is compound-specific and its strength is determined by the compound structure and the type (and concentration) of ions inducing the response.

  1. Removal of beta-blockers from aqueous media by adsorption onto graphene oxide. (United States)

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


    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.

  2. Determination of micelle formation of ketorolac tromethamine in aqueous media by acoustic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Savaroglu, Gokhan, E-mail: [Eskisehir Osmangazi University, Department of Physics, 26480 Eskisehir (Turkey); Genc, Luetfi [Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Technology, 26470 Eskisehir (Turkey)


    Graphical abstract: Value of critical micelle concentration (CMC) were detected by speed of sound and determined by an analytical method based on the Phillips definition of the CMC. Highlights: Black-Right-Pointing-Pointer The aim of this study was to investigate the aggregation behaviour of KT. Black-Right-Pointing-Pointer Influence of KT concentration and temperature upon volumetric properties was studied. Black-Right-Pointing-Pointer CMC of KT aqueous solution was determined by using speeds of sound measurements. - Abstract: Density and speed of sound of ketorolac tromethamine in aqueous solutions have been measured as a function of concentration at atmospheric pressure and in the temperature range from 293.15 to 313.15 K. Apparent molar volumes, apparent isentropic compressibility and isentropic compressibility values have also been calculated from the experimental density and speed of sound data. Partial molar volume and partial molar isentropic compressibility are obtained from fitting procedures the data on apparent molar volume, V{sub {phi}}, and apparent isentropic compressibility, K{sub {phi}(S)}. Partial molar volume, V{sub {phi}}{sup 0}, and partial molar isentropic compressibility, k{sub {phi}(S)}{sup 0}, are informative thermodynamic characteristics that reflect solute hydration. The critical micelle concentration (CMC) was determined from speed of sound data by an analytical method based on the Phillips definition of the CMC. Using these results, it was possible to establish the solvent-drug interactions.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yunfei; Li, Yan, E-mail:; Zhong, Xinhua, E-mail:


    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.

  4. Lipase-catalyzed syntheses of sugar esters in non-aqueous media. (United States)

    Kobayashi, Takashi


    The lipase-catalyzed reaction is useful to obtain sugar esters with chemically defined structures and will contribute to the synthesis of sugar-based compounds by a chemo-enzymatic pathway. The synthesis of sugar esters in nonaqueous media has been attempted for a quarter century. To facilitate the reactions, they have been performed either in an organic solvent with/without a polar adjuvant or in an ionic liquid, or by using a hydrophobic sugar derivative. In this review, the following points are discussed: (1) various synthetic methods of sugar esters; (2) role of the solvents or adjuvants; and (3) improvement in the productivity.

  5. Effects of aqueous media on microbial removal of sulfur from dibenzothiophene in the presence of hydrocarbons

    Institute of Scientific and Technical Information of China (English)


    Effects of the aqueous components, pH, concentration of NaCl, and volume ratios of oil-to-water on the desulfurization activity of gram-negative desulfurizing bacterium, Pseudomonas delafieldii R-8, were investigated. R-8 showed high desulfurization activity even with a concentration of NaCl up to 60 g@L-1 or high content of dodecane over 83%. The addition of NADH could increase the desulfurization activity of the whole cells. The desulfurization of DBT could be proceeded in the presence of hydrocarbons with the carbon length ranging from 6 to16. Among them, the largest specific desulfurization activity was shown in dodecane, the value of which was 1.96 mg@g-1@h-1 similar to that of R. erythropolis IGTS8.

  6. Organo/Zn-Al LDH Nanocomposites for Cationic Dye Removal from Aqueous Media (United States)

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


    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.

  7. Solubilization and quantification of lycopene in aqueous media in the form of cyclodextrin binary systems. (United States)

    Vertzoni, Maria; Kartezini, Theodora; Reppas, Christos; Archontaki, Helen; Valsami, Georgia


    An optimized kneading method for the preparation of lycopene-cyclodextrin binary systems was developed leading to solubilization of lycopene in water and 5% (w/v) dextrose solution. Lycopene quantification in the prepared binary systems was performed by a developed spectrometric method that followed a successful single-step extraction with dichloromethane. Storage stability characteristics of the binary systems were studied at 4 degrees C in solution and at -20 degrees C in the lyophilized products. Lycopene content was monitored at lambda(max)=482 nm, the limit of detection was 0.41 microg/ml and relative standard deviation was less than 3.1%. The results obtained with the spectrometric method were confirmed by a HPLC method. In the presence of cyclodextrins, lycopene concentration in water was 8.0+/-1.0, 27.1+/-3.2 and 16.0+/-2.2 microg/ml for beta-CD, HP-beta-CD and Me-beta-CD, respectively. In 5% (w/v) aqueous dextrose solutions the corresponding values were 16.0+/-1.8, 48.0+/-5.1 and 4.0+/-0.5 microg/ml, respectively. At 4 degrees C, storage stability of lycopene-cyclodextrin binary systems in water or 5% (w/v) aqueous dextrose solutions, was limited (t(1/2)=1-4 days). Addition of the antioxidant sodium metabisulfite increased the stability of lycopene-HP-beta-CD binary system in water. At -20 degrees C, the lyophilized lycopene-cyclodextrin binary systems were stable for at least 2 weeks.

  8. Efficient isomerization of glucose to fructose over zeolites in consecutive reactions in alcohol and aqueous media. (United States)

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


    Isomerization reactions of glucose were catalyzed by different types of commercial zeolites in methanol and water in two reaction steps. The most active catalyst was zeolite Y, which was found to be more active than the zeolites beta, ZSM-5, and mordenite. The novel reaction pathway involves 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 chemicals like alkyl levulinates is viable at higher temperatures.

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

    Directory of Open Access Journals (Sweden)

    Elena M. Balboa


    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.

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

    Indian Academy of Sciences (India)

    P N Singh; D Tiwary; I Sinha


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

  11. A selective fluorescent 'turn-on' sensor for recognition of Zn2 + in aqueous media (United States)

    Ozdemir, Mecit


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yan, E-mail: [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)


    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.

  13. Pb (II) removal from aqueous media by EDTA-modified mesoporous silica SBA-15. (United States)

    Huang, Jin; Ye, Meng; Qu, Yuqi; Chu, Lianfeng; Chen, Rui; He, Qizhuang; Xu, Dongfang


    An organic-inorganic hybrid mesoporous silica material was synthesized by two-step post-grafting method of SBA-15 with 3-aminopropyltrimethoxy-silane (APTES) and thionyl dichloride (SOCl(2)) activated ethylenediaminetetraacetic acid (EDTA) in sequence and measured by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), elemental analysis (EA), transmission electron microscopy (TEM), nitrogen (N(2)) adsorption-desorption analysis and back titration. The material was found having the beneficial properties of mesoporous silica SBA-15 and EDTA. Adsorption potential of the material for Pb (II) removal from aqueous solution was investigated by varying experimental conditions such as pH, contact time and initial metal concentration. The removal efficiency of Pb(2+) was high under studied experimental conditions. The adsorption equilibrium could be reached within 20 min and the kinetic data were fitted well by pseudo-second-order and intraparticle diffusion model. The adsorbent exhibited a favorable performance and its maximum adsorption capacity calculated by the Langmuir model was 273.2 mg g(-1). Recycling experiments showed the adsorbent could be regenerated by acid treatment without altering its properties. The chemical states of the elements involved in the adsorption were analyzed by X-ray photoelectron spectroscopy (XPS). The results demonstrated that the adsorption mechanism of the material involved Na Pb ion-exchange and carboxyl group dominated surface complexation.

  14. Reusable fluorescent photocrosslinked polymeric sensor for determining lead ions in aqueous media (United States)

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


    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.

  15. 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:; 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)


    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.

  16. Interaction of inorganic anions with iron-mineral adsorbents in aqueous media--a review. (United States)

    Kumar, Eva; Bhatnagar, Amit; Hogland, William; Marques, Marcia; Sillanpää, Mika


    A number of inorganic anions (e.g., nitrate, fluoride, bromate, phosphate, and perchlorate) have been reported in alarming concentrations in numerous drinking water sources around the world. Their presence even in very low concentrations may cause serious environmental and health related problems. Due to the presence and significance of iron minerals in the natural aquatic environment and increasing application of iron in water treatment, the knowledge of the structure of iron and iron minerals and their interactions with aquatic pollutants, especially inorganic anions in water are of great importance. Iron minerals have been known since long as potential adsorbents for the removal of inorganic anions from aqueous phase. The chemistry of iron and iron minerals reactions in water is complex. The adsorption ability of iron and iron minerals towards inorganic anions is influenced by several factors such as, surface characteristics of the adsorbent (surface area, density, pore volume, porosity, pore size distribution, pHpzc, purity), pH of the solution, and ionic strength. Furthermore, the physico-chemical properties of inorganic anions (pore size, ionic radius, bulk diffusion coefficient) also significantly influence the adsorption process. The aim of this paper is to provide an overview of the properties of iron and iron minerals and their reactivity with some important inorganic anionic contaminants present in water. It also summarizes the usage of iron and iron minerals in water treatment technology.

  17. Removal of artificial sweetener aspartame from aqueous media by electrochemical advanced oxidation processes. (United States)

    Lin, Heng; Oturan, Nihal; Wu, Jie; Sharma, Virender K; Zhang, Hui; Oturan, Mehmet A


    The degradation and mineralization of aspartame (ASP) in aqueous solution were investigated, for the first time, by electrochemical advanced oxidation processes (EAOPs) in which hydroxyl radicals were formed concomitantly in the bulk from Fenton reaction via in situ electrogenerated Fenton's reagent and at the anode surface from the water oxidation. Experiments were performed in an undivided cylindrical glass cell with a carbon-felt cathode and a Pt or boron-doped diamond (BDD) anode. The effect of Fe(2+) concentration and applied current on the degradation and mineralization kinetics of ASP was evaluated. The absolute rate constant for the reaction between ASP and OH was determined as (5.23 ± 0.02) × 10(9) M(-1) s(-1) by using the competition kinetic method. Almost complete mineralization of ASP was achieved with BDD anode at 200 mA constant current electrolysis. The formation and generation of the formed carboxylic acids (as ultimate end products before complete mineralization) and released inorganic ion were monitored by ion-exclusion high performance liquid chromatography (HPLC) and ion chromatography techniques, respectively. The global toxicity of the treated ASP solution during treatment was assessed by the Microtox(®) method using V. fischeri bacteria luminescence inhibition.

  18. Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media (United States)

    Deshmukh, Ruchi; Mehra, Anurag


    Aggregation and self-assembly are influenced by molecular interactions. With precise control of molecular interactions, in this study, a wide range of nanostructures ranging from zero-dimensional nanospheres to hierarchical nanoplates and spindles have been successfully synthesized at ambient temperature in aqueous solution. The nanostructures reported here are formed by aggregation of spherical seed particles (monomers) in presence of quaternary ammonium salts. Hydroxide ions and a magnetic moment of the monomers are essential to induce shape anisotropy in the nanostructures. The cobalt nanoplates are studied in detail, and a growth mechanism based on collision, aggregation, and crystal consolidation is proposed based on a electron microscopy studies. The growth mechanism is generalized for rods, spindles, and nearly spherical nanostructures, obtained by varying the cation group in the quaternary ammonium hydroxides. Electron diffraction shows different predominant lattice planes on the edge and on the surface of a nanoplate. The study explains, hereto unaddressed, the temporal evolution of complex magnetic nanostructures. These ferromagnetic nanostructures represent an interesting combination of shape anisotropy and magnetic characteristics.

  19. Extremophile mediated hydrogen production for hydrogenation of substrates in aqueous media (United States)

    Anjom, Mouzhgun

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

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

    Directory of Open Access Journals (Sweden)

    L. Pappalardo


    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.

  1. O2 solubility in aqueous media determined by a kinetic method. (United States)

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


    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.

  2. 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


    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.

  3. 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


    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.

  4. Adsorptive micro-extraction techniques--novel analytical tools for trace levels of polar solutes in aqueous media. (United States)

    Neng, N R; Silva, A R M; Nogueira, J M F


    A novel enrichment technique, adsorptive μ-extraction (AμE), is proposed for trace analysis of polar solutes in aqueous media. The preparation, stability tests and development of the analytical devices using two geometrical configurations, i.e. bar adsorptive μ-extraction (BAμE) and multi-spheres adsorptive μ-extraction (MSAμE) is fully discussed. From the several sorbent materials tested, activated carbons and polystyrene divinylbenzene phases demonstrated the best stability, robustness and to be the most suitable for analytical purposes. The application of both BAμE and MSAμE devices proved remarkable performance for the determination of trace levels of polar solutes and metabolites (e.g. pesticides, disinfection by-products, drugs of abuse and pharmaceuticals) in water matrices and biological fluids. By comparing AμE techniques with stir bar sorptive extraction based on polydimethylsiloxane phase, great effectiveness is attained overcoming the limitations of the latter enrichment approach regarding the more polar solutes. Furthermore, convenient sensitivity and selectivity is reached through AμE techniques, since the great advantage of this new analytical technology is the possibility to choose the most suitable sorbent to each particular type of application. The enrichment techniques proposed are cost-effective, easy to prepare and work-up, demonstrating robustness and to be a remarkable analytical tool for trace analysis of priority solutes in areas of recognized importance such as environment, forensic and other related life sciences.

  5. 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


    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.

  6. High performing solution-coated electrolyte-gated organic field-effect transistors for aqueous media operation (United States)

    Zhang, Qiaoming; Leonardi, Francesca; Casalini, Stefano; Temiño, Inés; Mas-Torrent, Marta


    Since the first demonstration, the electrolyte-gated organic field-effect transistors (EGOFETs) have immediately gained much attention for the development of cutting-edge technology and they are expected to have a strong impact in the field of (bio-)sensors. However EGOFETs directly expose their active material towards the aqueous media, hence a limited library of organic semiconductors is actually suitable. By using two mostly unexplored strategies in EGOFETs such as blended materials together with a printing technique, we have successfully widened this library. Our benchmarks were 6,13-bis(triisopropylsilylethynyl)pentacene and 2,8-difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT), which have been firstly blended with polystyrene and secondly deposited by means of the bar-assisted meniscus shearing (BAMS) technique. Our approach yielded thin films (i.e. no thicker than 30 nm) suitable for organic electronics and stable in liquid environment. Up to date, these EGOFETs show unprecedented performances. Furthermore, an extremely harsh environment, like NaCl 1M, has been used in order to test the limit of operability of these electronic devices. Albeit an electrical worsening is observed, our devices can operate under different electrical stresses within the time frame of hours up to a week. In conclusion, our approach turns out to be a powerful tool for the EGOFET manufacturing.

  7. Curcumin-cysteine and curcumin-tryptophan conjugate as fluorescence turn on sensors for picric Acid in aqueous media. (United States)

    Gogoi, Bedanta; Sen Sarma, Neelotpal


    Rapid detection of picric acid in real sample is of outmost importance from the perspective of health, safety, and environment. In this study, a very simple and cost-effective detection of picric acid is accomplished by developing a couple of biobased conjugates curcumin-cysteine (CC) and curcumin-tryptophan (CT), which undergo efficient fluorescence turn on toward picric acid in aqueous media. Both the probes experience about 26.5-fold fluorescence enhancements at 70 nM concentration of the analyte. Here, the fluorescence turn on process is governed by the aggregation induced emission, which is induced from the electrostatic interaction between the conjugates with picric acid. The detection limit of CC and CT are about 13.51 and 13.54 nM of picric acid, respectively. Importantly, both the probes exhibit high selectivity and low interference of other analogues toward the detection of picric acid. In addition, the probes are highly photostable, show low response time and are practically applicable for sensing picric acid in real environmental samples, which is the ultimate goal of this work.

  8. Effect of Surface Charge on Surface-Initiated Atom Transfer Radical Polymerization from Cellulose Nanocrystals in Aqueous Media. (United States)

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


    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.

  9. Surfactant and Gelation Properties of Acetylsalicylate Based Room Temperature Ionic Liquid in Aqueous Media. (United States)

    Sastry, Nandhibatla V; Singh, Dipak K


    An amphiphilic room temperature ionic liquid (RTIL) containing acetylsalicylate anion of type 1-dodecyl-1-methylpiperidinium acetylsalicylate, [C12mpip][AcSa], is synthesized from the precursor [C12mpip][Cl] by an ion exchange process. The sample is characterized, and its surface active and aggregation behavior in water has been studied and explained. The critical aggregation concentrations (CACs) are determined by a variety of methods, namely, electrical conductivity, surface tension, steady state florescence, and isothermal titration calorimetry (ITC) at different temperatures. As compared to its precursor, [C12mpip][AcSa] has low CAC values, indicating enhanced favorable interactions between the [alkylmpip](+) cation···bulky [AcSa](-) anion and also hydrogen bonding of both of the ions with water. The free energy of aggregation ΔG(0)a is always negative, and both enthalpy and entropy of aggregation drive the aggregation process. The micelle-like aggregates are ellipsoidal in shape. The aggregation numbers are determined from translational diffusion coefficients and florescence quenching measurements. Aggregates of [C12mpip][AcSa] are larger than those of its precursor IL with chloride anion. Therefore, it is evident that the close interactions between the ion pairs of [C12mpip](+)···[AcSa](-) facilitate packing of more molecules in an aggregate. The steady state and oscillatory rheology measurements in aqueous solutions consisting of mixtures of [C12mpip][AcSa] and sodium salicylate (SS), an hydrotope additive, were carried out. The analysis of zero shear viscosity and moduli properties as a function of concentration and temperature reveals that the addition of SS promotes the growth of small ellipsoid aggregates into large worm-like structures with a typical viscoelastic gel behavior. The moduli properties vs temperature profiles are complex and no hysteresis was produced in heating and cooling modes, suggesting the thermoirreversibile and complex nature

  10. 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:; 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)


    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.

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

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

    Sarkar, Kangkana; Ansari, Zarina; Sen, Kamalika


    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.

  13. Renaissance architecture for Ground Data Systems (United States)

    Perkins, Dorothy C.; Zeigenfuss, Lawrence B.


    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

  14. Perceptions of beauty in Renaissance art. (United States)

    Haughton, Neil


    The Renaissance was a cultural revolution that spread from Florence, in 1400, throughout Italy and into the rest of Europe. Its impetus was the philosophy of Humanism, which strove to resurrect and emulate the literature and art of the ancient Greeks and Romans. Artists had previously been limited to formulaic religious iconography. They now began to reproduce descriptions of classical paintings and copy the antique statues that were being newly rediscovered. The Renaissance artist's perception of beauty was therefore determined by his philosophical environment, his visual experience (the 'period eye'), the demands of his patrons and by attempts to enhance his professional status in society to equal that of poets and architects. The image of Venus portrayed by Botticelli as the idealization of beauty in Renaissance Florence is significantly different from the Venus portrayed by the German artist, Lucas Cranach. The northern European Venus is much less voluptuous than her Italian counterpart but is still inspired by humanist principals and retains considerable sexuality. Raphael's paintings epitomise the idealization of female beauty of this period but, by his own admission they were rarely based on real models. Often the same facial type was repeated in many different paintings. Indeed Renaissance portrait artists tended to avoid realistic interpretation, emphasizing instead the positive attributes of their subjects, both physical and political. Thus, Bronzino's Portrait of a Young Man not only depicts his subject's idealized appearance but also his scholarship, background and potential. The depiction of beauty in Renaissance art is shown to be more complex than a mere photograph-like representation of sexuality or of a person's physical appearance. Instead, Renaissance art created physically perfect images resulting from scholarly expectation, the artist's ambitions and his developing skills.

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

    Basch, Angelika; Strnad, Simona


    This work investigated colloidal properties such as the zeta-potential, the electrophoretic mobilities and the wetting behaviour of alumina dispersed in non-aqueous media. Non-aqueous dispersions of alumina were prepared in the solvent N-methyl-2-pyrrolidinone (NMP). The wetting behaviour of alumina in NMP was characterized by the powder contact angle method and the Wilhemy plate method. The behaviour of the dispersion should provide information for the development of a substrate-induced coagulation (SIC) coating process of nano-sized alumina in non-aqeous media. SIC is a dip-coating process that coats pretreated but chemically different surfaces with nano-sized particles. It was found that the anionic surfactant dioctyl sulfosuccinate (AOT) had no stabilizing effect on alumina dispersed in NMP.

  16. Economic Globalization and a Nuclear Renaissance

    Energy Technology Data Exchange (ETDEWEB)

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


    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. An Efficient and Practical Process for Pd/Cu Cocatalyzed Homocoupling Reaction of Terminal Alkynes Using Sodium Percarbonate as a Dual Reagent in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    ZHOU, Lei; ZHAN, Hai-Ying; LIU, Hai-Ling; JIANG, Huan-Feng


    A new process for the Pd/Cu co-catalyzed homocoupling reaction of terminal alkynes was developed. The reaction was carried out in aqueous media with sodium percarbonate as both a clean oxidant and a base. Meanwhile, a palladium complex immobilized on a synthetic PS-PEG400-PPh2 resin was used as the catalyst, which may be recovered by simple filtration and reused for several times with high activity.

  18. Molecularly Imprinted Polymers with Bi-functional Monomers of Polymerizable Cyclodextrin Derivatives and 2-(Diethylamino)-ethyl Methacrylate for Recognition of Norfloxacin in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    Zhi Feng XU; Lan LIU; Qin Ying DENG


    A molecularly imprinted polymer was synthesized using 2-(diethylamino)ethylmethacry -late(DEM) and bismethacryloyl-β-cyclodextrin(BMA-β-CD) as bi-functional monomers and norfloxacin(NOF) as a template. The results of equilibrium binding experiments indicated that the polymer has affinity and specificity for NOF in aqueous media, and that its selective recognition ability for the template was higher than that of the imprinted polymers synthesized with a single functional monomer (BMA-β-CD or DEM).

  19. Philadelphia's Renaissance Schools Initiative after Four Years (United States)

    Stratos, Kati; Wolford, Tonya; Reitano, Adrienne


    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.…

  20. Rubus Iconography: Antiquity to the Renaissance (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...

  1. Manuel Chrysoloras and the Early Italian Renaissance

    Directory of Open Access Journals (Sweden)

    Ian Thomson


    Full Text Available Several of the major figures in the Renaissance reckoned Chrysoloras’ teaching in Florence (1397-1400 as the decisive step in the rebirth of learning; but he was there probably also as a diplomat, to encourage western support for the defense of the east.

  2. Humanism and Humanitarianism before the Renaissance. (United States)

    Weller, Allen S.


    The characteristics of the humanism and humanitarianism of the developed Renaissance are revival of classicism, delight in life, experimentalism, individualism, realism, love of beauty, increased secularism, and versatility of gifted individuals. An examination of artistic works created from 1260 to 1310 suggests that these qualities were evident…

  3. Paracelsus: the Hippocrates of the Renaissance. (United States)

    Siddiqui, Mumtaz A; Mehta, Nirav J; Khan, Ijaz A


    Paracelsus lived during the Renaissance. His sober spirit of scientific observation and critical reason were accompanied by emotional turbulence and a volcanic temperament. He remains both a mystery and an object of nostalgia. Paracelsus is today celebrated as the first modern medical scientist. Paracelsus' early life, achievements and latter years are described.

  4. Renaissance Theatre in a General Education Program. (United States)

    Lenz, Carolyn R.; Hutchinson, P. William

    A course in Renaissance theatre offered within the general studies curriculum at Rhode Island College introduced students to the field of Jacobean and Elizabethan drama and to the dramatic arts, provided opportunities for students to help produce and act in scenes from several plays, and revealed to them the importance of vivid and detailed…

  5. Cp*Co(III) catalysts with proton-responsive ligands for carbon dioxide hydrogenation in aqueous media. (United States)

    Badiei, Yosra M; Wang, Wan-Hui; Hull, Jonathan F; Szalda, David J; Muckerman, James T; Himeda, Yuichiro; Fujita, Etsuko


    New water-soluble pentamethylcyclopentadienyl cobalt(III) complexes with proton-responsive 4,4'- and 6,6'-dihydroxy-2,2'-bipyridine (4DHBP and 6DHBP, respectively) ligands have been prepared and were characterized by X-ray crystallography, UV-vis and NMR spectroscopy, and mass spectrometry. These cobalt(III) complexes with proton-responsive ligands predominantly exist in their deprotonated [Cp*Co(DHBP-2H(+))(OH2)] forms with stronger electron-donating properties in neutral and basic solutions, and are active catalysts for CO2 hydrogenation in aqueous bicarbonate media at moderate temperature under a total 4-5 MPa (CO2:H2 1:1) pressure. The cobalt complexes containing 4DHBP ligands ([1-OH2](2+) and [1-Cl](+), where 1 = Cp*Co(4DHBP)) display better thermal stability and exhibit notable catalytic activity for CO2 hydrogenation to formate in contrast to the catalytically inactive nonsubstituted bpy analogues [3-OH2](2+) (3 = Cp*Co(bpy)). While the catalyst Cp*Ir(6DHBP)(OH2)(2+) in which the pendent oxyanion lowers the barrier for H2 heterolysis via proton transfer through a hydrogen-bonding network involving a water molecule is remarkably effective (ACS Catal. 2013, 3, 856-860), cobalt complexes containing 6DHBP ligands ([2-OH2](2+) and [2-Cl](+), 2 = Cp*Co(6DHBP)) exhibit lower TOF and TON for CO2 hydrogenation than those with 4DHBP. The low activity is attributed to thermal instability during the hydrogenation of CO2 as corroborated by DFT calculations.

  6. 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:; Wan, Liang


    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.

  7. Self-media

    DEFF Research Database (Denmark)

    Fausing, Bent


    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. 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: [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: [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)


    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

  9. Extraction and separation of tungsten (VI) from aqueous media with Triton X-100-ammonium sulfate-water aqueous two-phase system without any extractant. (United States)

    Yongqiang Zhang; Tichang Sun; Tieqiang Lu; Chunhuan Yan


    An aqueous two-phase system composed of Triton X-100-(NH4)2SO4-H2O was proposed for extraction and separation of tungsten(VI) from aqueous solution without using any extractant. The effects of aqueous pH, concentration of ammonium sulfate, Triton X-100 and tungsten, extracting temperature on the extraction of tungsten were investigated. The extraction of tungsten has remarkable relationship with aqueous pH and are to above 90% at pH=1.0-3.0 under studied pH range (pH=1.0-7.0) and increases gradually with increasing Triton X-100 concentration, but decreases slightly with increasing ammonium sulfate concentration. The extraction percentage of tungsten is hardly relevant to temperature but its distribution coefficient linearly increases with increasing temperature within 303.15-343.15K. The distribution coefficient of tungsten increases with the increase of initial tungsten concentration (0.1-3%) and temperature (303.15 K-333.15K). The solubilization capacity of tungsten in Triton X-100 micellar phase is independent of temperature. FT-IR analysis reveals that there is no evident interaction between polytungstate anion and ether oxygen unit in Triton X-100, and DLS analysis indicates that zeta potential of Triton X-100 micellar phase have a little change from positive to negative after extracting tungsten. Based on the above-mentioned results, it can be deduced that polytungstate anions are solubilized in hydrophilic outer shell of Triton X-100 micelles by electrostatic attraction depending on its relatively high hydrophobic nature. The stripping of tungsten is mainly influenced by temperature and can be easily achieved to 95% in single stage stripping. The tungsten (VI) is separated out from solution containing Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Al(III), Cr(III) and Mn(II) under the suitable conditions.

  10. Nanomolar detection of hypochlorite by a rhodamine-based chiral hydrazide in absolute aqueous media: application in tap water analysis with live-cell imaging. (United States)

    Goswami, Shyamaprosad; Das, Avijit Kumar; Manna, Abhishek; Maity, Anup Kumar; Saha, Partha; Quah, Ching Kheng; Fun, Hoong-Kun; Abdel-Aziz, Hatem A


    By employing the oxidation property of hypochlorite (OCl(-)), a novel rhodamine-based hydrazide of the chiral acid ((S)-(-)-2-pyrrolidone-5-carboxylic acid) (RHHP) was designed and synthesized for detection of OCl(-) absolutely in aqueous medium at nanomolar level. The structure of the chiral sensor was also proved by the X-ray crystallography. The bioactivity and the application of the probe for detection of OCl(-) in natural water system have been demonstrated. A plausible mechanism for oxidation of the sensor followed by hydrolysis is also proposed. The sensibility of the receptor toward OCl(-) was studied in absolute aqueous media, and the detection limit of hypochlorite-mediated oxidation to the receptor in nanomolar level makes this platform (RHHP) an ultrasensitive and unique system for OCl(-) oxidation.

  11. Liturgie, transformasie en die Afrika Renaissance

    Directory of Open Access Journals (Sweden)

    B. de Klerk


    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.

  12. A study in Renaissance psychotropic plant ointments. (United States)

    Piomelli, D; Pollio, A


    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.

  13. The Renaissance or the cuckoo clock. (United States)

    Pines, Jonathon; Hagan, Iain


    '…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.

  14. Aspects on the catalysis of lipase from porcine pancreas (type VI-s) in aqueous media: development of ion-pairs



    This article reports a first contribution for the elucidation of catalytic mechanism of Lipase from porcine pancreas, type VI-s (PPL), in hydrolyzing an ester substrate in aqueous media. The conclusions were based on the pH-profiles of Michaelis-Menten parameters k cat/Km, k cat and Km, as well as on the absolute temperature profile of k cat/Km, obtained during the hydrolysis of p-nitrophenyl laurate by PPL. It was found that (a) PPL performs catalysis by means of ion pairs formed either as S...

  15. Comparative Studies on Conventional and Ultrasound-Assisted Synthesis of Novel Homoallylic Alcohol Derivatives Linked to Sulfonyl Dibenzene Moiety in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Mohamed F. Mady


    Full Text Available Novel homoallylic alcohols incorporating sulfone moieties were synthesized by the treatment of different carbonyl compounds with allylic bromides in aqueous media via sonochemical Barbier-type reaction conditions. Sulfonation of α-bromoketones with sodium benzenesulfinate in presence of CuI/2,6-lutidine rapidly gave β-keto-sulfones in good yields. In general, ultrasound irradiation offered the advantages of high yields, short reaction times, and simplicity compared to the conventional methods. The structures of all the compounds were confirmed by analytical and spectral data.

  16. Renaissance Humanists:Defenders of Medieval Christian worldview

    Institute of Scientific and Technical Information of China (English)



    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.

  17. Cooperative catalysis of noncompatible catalysts through compartmentalization: wacker oxidation and enzymatic reduction in a one-pot process in aqueous media. (United States)

    Sato, Hirofumi; Hummel, Werner; Gröger, Harald


    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.

  18. Brain ‘imaging’ in the Renaissance (United States)

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


    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 Galen1 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


    DEFF Research Database (Denmark)

    Fausing, Bent


    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...

  20. Tailor-made micro-object optical sensor based on mesoporous pellets for visual monitoring and removal of toxic metal ions from aqueous media. (United States)

    El-Safty, Sherif A; Shenashen, M A; Shahat, A


    Methods for the continuous monitoring and removal of ultra-trace levels of toxic inorganic species (e.g., mercury, copper, and cadmium ions) from aqueous media such as drinking water and biological fluids are essential. In this paper, the design and engineering of a simple, pH-dependent, micro-object optical sensor is described based on mesoporous aluminosilica pellets with an adsorbed dressing receptor (a porphyrinic chelating ligand). This tailor-made optical sensor permits ultra-fast (≤ 60 s), specific, pH-dependent visualization and removal of Cu(2+) , Cd(2+) , and Hg(2+) at sub-picomolar concentrations (∼10(-11) mol dm(-3) ) from aqueous media, including drinking water and a suspension of red blood cells. The acidic active acid sites of the pellets consist of heteroatoms arranged around uniformly shaped pores in 3D nanoscale gyroidal mesostructures densely coated with the chelating ligand. The sensor can be used in batch mode, as well as in a flow-through system in which sampling, target ion recognition and removal, and analysis are integrated in a highly automated and efficient manner. Because the pellets exhibit long-term stability, reproducibility, and versatility over a number of analysis/regeneration cycles, they can be expected to be useful for the fabrication of inexpensive sensor devices for naked-eye detection of toxic pollutants.

  1. Development of a pH-responsive imprinted polymer for diclofenac and study of its binding properties in organic and aqueous media. (United States)

    Mohajeri, Seyed Ahmad; Malaekeh-Nikouei, Bizhan; Sadegh, Hasan


    Three different molecularly imprinted polymers (MIPs) for drug delivery of diclofenac in gastrointestinal tract were synthesized employing bulk polymerization method and their binding and release properties were studied in different pH values. Methacrylic acid (MAA), methacrylamide (MAAM) and 4-vinyl pyridine (4VP) were tested as functional monomers and ethylene glycole dimethacrylate (EDMA) was used as a cross-linker monomer in polymeric feed. Binding properties and imprinting factor (IF) of MIPs were studied in comparison with their non-imprinted ones (Blank) in organic and aqueous media. Diclofenac release in aqueous solvents at pH values of 1.5, 6.0 and 8.0, simulating gastrointestinal fluids, were also studied. The results indicated the specific binding of diclofenac to imprinted polymers. Duo to the stronger non-specific bounds in aqueous solutions, IF values decreased in water compared to acetonitrile as an organic medium. Our results proved that all polymers represented pH-responsive diclofenac delivery at above conditions. The data showed that imprinted polymer, prepared by MAA had superior properties, in comparison with other polymers, for minimum release (14%) of drug in gastric acid and maximum release (90%) in basic condition. The results indicated that diclofenac imprinted polymer could be used as a pH-responsive matrix in preparation of a new drug delivery system for diclofenac.

  2. 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. (United States)

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


    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.

  3. 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


    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)

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


    A. M Nemeryuk; M. M Lylina


    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.

  5. The dawn of the third renaissance in surgery. (United States)

    Hackam, David J


    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.

  6. Philadelphia's Renaissance Schools: Start up and Early Implementation. Executive Summary (United States)

    Research for Action, 2011


    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…

  7. Accelerated Reader/Reading Renaissance. What Works Clearinghouse Intervention Report (United States)

    What Works Clearinghouse, 2007


    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…

  8. Seeing, Hearing and Doing the Renaissance (Part 2) (United States)

    Osowiecki, Maria


    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…

  9. Lessons from the Renaissance: The Power of Multiple Knowledge Bases (United States)

    Whitmire, Kathleen; Beck, Joanna


    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…

  10. The thesaurus review, renaissance, and revision

    CERN Document Server

    Roe, Sandra K


    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,

  11. The Art of the Renaissance Capitalist State

    Directory of Open Access Journals (Sweden)

    Rebeka Vidrih


    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.

  12. Iba Techniques to Study Renaissance Pottery Techniques (United States)

    Bouquillon, A.; Castaing, J.; Salomon, J.; Zucchiatti, A.; Lucarelli, F.; Mando, P. A.; Prati, P.; Lanterna, G.; Vaccari, M. G.


    The application of Ion Beam Analysis, associated to Scanning Electron Microscopy is examined in connection with an extensive program on structural and chemical analyses of glazed terracotta's from the Italian Renaissance, launched by a French-Italian collaboration in the framework of the European COST-G1 scientific action. The objectives of the collaboration are reviewed. The compatibility of data from different specimen and various laboratories are discussed. Examples of the PIXE and statistical analyses on some artefacts of the "Robbiesche" type, supplied by the Louvre Museum of Paris and the Opificio delle Pietre Dure of Florence, are given to illustrate the performances of IBA in this particular field.

  13. 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)


    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.


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

  15. 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


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

  16. Water systems in the assumptions of Renaissance gardens

    Directory of Open Access Journals (Sweden)

    Margot Dudkiewicz


    Full Text Available The Renaissance took place in Europe in the XVth and XVIth centuries. As far as garden composition was concerned it reached excellence both in Italy, France, England and Germany. Initially there were three solutions observed in the area of the composition of water-based systems: swimming pools, waterfalls and fountains overflowing with water. Since 1600, a preference in aqueous systems was revealed for the use of a high column of water requiring special pressure equipment. The fountains were arranged in a pyramidal composition, similar to trees (“trees of life”. In the period water was supposed to be in constant motion. Fountains had a shaft on which tanks were suspended. They served the purpose of transmitting water to pour it. The fountain was supposed to be an architectural piece consisting of three parts which evolved into a slender form, with a high shaft and decorative sculptures. The main theme of sculptures-decorated fountains was the man, antique motives such as philosophers, as well as water, see and ocean deities – tritons and nymphs. The presence of the constructions emphasized the decorativeness and compositional significance of the successive places in the garden. XVIth century observed the fashion for water arts – an unaware person stepping or hand-touching a place or a detail could cause an abrupt gush of water, spraying yourself or people around. Water steps were constructed, too. They allowed to pass to the lower garden part, while water was flowing down in a stone trough. The Polish Renaissance garden art was characteristic for its symbolic presence of aesthetic elements and prevailing role of water as utility factor. The decorative elements were scarce. The real development of garden art was observed mainly around monasteries and castles. In the city of Oliwa there was an olive-tree-shaped fountain ejecting water from the fruits and tree leaves into a marble tank. The studies carried out within the framework of the

  17. Recovery of metals from simulant spent lithium-ion battery as organophosphonate coordination polymers in aqueous media. (United States)

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


    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.

  18. 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)


    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.

  19. Construction of a low-cost detector to identify dissolved metals in aqueous media by fluorescence spectroscopy: design and perspectives. (United States)

    González, M.; Montaño, M.; Hoyo, C.


    We have constructed a low cost fluorescence detector model to determine the presence of some heavy metals in an aqueous medium. In particular, we focus on metals which cause public health problems in our country. We did the first tests with standard samples of Hg (II). The innovative features of this instrument are its small dimensions (9 dm3) and the low cost of materials used in its construction.

  20. 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


    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.

  1. A wetting experiment as a tool to study the physicochemical processes accompanying the contact of hydrophobic and superhydrophobic materials with aqueous media. (United States)

    Boinovich, Ludmila; Emelyanenko, Alexandre


    In most fields of technological application of superhydrophobic materials, such as protection against corrosion, icing, and capillary condensation, or micro fluidics applications, a superhydrophobic surface has to operate in contact with aggressive aqueous media. Therefore, the peculiarities of behaviour of hydrophobic and superhydrophobic surfaces on prolonged contact with water and the mechanisms of possible degradation of superhydrophobicity need to be discussed. In this study, a consideration of the physicochemical processes accompanying the contact of hydrophobic and superhydrophobic materials with water, acid, alkaline and saline aqueous solutions is presented on the basis of experimental data on three-phase equilibrium obtained by the sessile drop method. It is shown that simultaneous analysis of the contact angle and contact diameter of the sessile drop and liquid/vapour surface tension allows one to attribute degradation of the superhydrophobic and hydrophobic state to reversible and irreversible processes such as hydrolysis of hydrophobic molecules, growth of an oxide layer and so on. A method for estimating both the portion of wetted area and the intrinsic wettability state (hydrophobic versus hydrophilic) of texture elements for a heterogeneous wetting regime is proposed and discussed.

  2. A water-soluble sulfonate-BODIPY based fluorescent probe for selective detection of HOCl/OCl⁻ in aqueous media. (United States)

    Kim, Jiyoung; Kim, Youngmi


    A new, water-soluble BODIPY dye 1, bearing sulfonate groups at the 2- and 6-positions was found to be a sensitive and selective fluorescent probe for the detection of HOCl/OCl(-) in aqueous buffer solution. The probe, which displays extremely weak fluorescence owing to efficient singlet excited state quenching by photoinduced electron transfer (PeT) from an electron-rich catechol group at a meso-position, responds to HOCl/OCl(-) through a dramatic enhancement of its fluorescence intensity.


    Directory of Open Access Journals (Sweden)

    N. Lopes,


    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

  4. Effect of Porous Media and Fluid Properties on Dense Non-Aqueous Phase Liquid Migration and Dilution Mass Flux (United States)


    system wettability that is directly related to contact angle. Fink (1970) experimentally measured breakthrough pressure for water repellent soils to...this study was to conduct water entry pressure, air and oil entry pressure tests for silica sand with various fractions of organic ( silane ) coated media... Water Repellency Based upon Contact Angle-Surface Tension Relationships, Soil Science Society of America Proceedings, 34:841-844, 1970. Wilson, J.L

  5. Pregnant Wit: ingegno in Renaissance England

    Directory of Open Access Journals (Sweden)

    Alexander Marr


    Full Text Available This article examines the protean nature of ingegno in Renaissance England. Beginning with dictionary definitions and period translations, it traces the semantics of ingegno in writings by Haydocke, Hilliard, Sidney, Harington, and Dee, and in images by Gheeraerts the elder and Hilliard. The term’s semantic elasticity carried over into English, changing shape to denote variously “wit”, “inborn talent”, “sharpness”, “swiftness”, “nobility”, “freedom”, and “ingenuity”. The article concludes by considering the socio-economics of ingenuity, and how the slippage between “ingenious” and “ingenuous” speaks to a newly emerging understanding of the liberal status of the artist and his craft.

  6. Optics at the dawn of the Renaissance (United States)

    Hockney, David; Falco, Charles M.


    Recently, one of us (DH) observed that certain drawings and paintings from as early as the Renaissance seemed almost "photographic" in detail. An extensive visual investigation of western art of the past 1000 years resulted in the revolutionary claim that artists even of the prominence of van Eyck and Bellini must have used optical aids. However, art historians insisted there was no supporting evidence for such a remarkable assertion. This paper presents some of the optical evidence we subsequently discovered that convincingly demonstrates optical instruments were in use - by artists, not scientists - nearly 200 years earlier than widely thought possible, and that accounts for the remarkable transformation in the reality of portraits that occurred early in the 15th century.

  7. The Network Metaphor & the New Renaissance

    Directory of Open Access Journals (Sweden)

    Foresta, Don


    Full Text Available This article is about art and science and a certain parallelism between them in the evolution of Western culture, particularly over the last 150 years. I will try to describe what changes have taken place in our society’s operational schema and our shared paradigm. My construct will be one of art, though a strong influence from science will be evident. I propose that we have been living through a second renaissance provoked by a profound change in the definition and representation of reality by both art and science. Throughout the 20th century, the ideas put forth by both have been extremely unconventional and the two have interacted in ways not always obvious, providing new metaphors, new patterns for defining the future shape of our culture.

  8. 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: [Laboratory of Environmental Pollution Control, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece)


    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

  9. Enhancement of Lipase Enzyme Activity in Non-Aqueous Media through a Rapid Three Phase Partitioning and Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    N. Saifuddin


    Full Text Available Three phase partitioning is fast developing as a novel bio-separation strategy with a wide range of applications including enzyme stability and enhancement of its catalytic activity. pH tuning of enzyme is now well known for use in non-aqueous systems. Tuned enzyme was prepared using a rapid drying technique of microwave dehydration (time required around 15 minutes. Further enhancement was achieved by three phase partitioning (TPP method. With optimal condition of ammonium sulphate and t-butanol, the protein appeared as an interfacial precipitate between upper t-butanol and lower aqueous phases. In this study we report the results on the lipase which has been subjected to pH tuning and TPP, which clearly indicate the remarkable increase in the initial rate of transesterification by 3.8 times. Microwave irradiation was found to increase the initial reaction rates by further 1.6 times, hence giving a combined increase in activity of about 5.4 times. Hence it is shown that microwave irradiation can be used in conjunction with other strategies (like pH tuning and TPP for enhancing initial reaction rates.

  10. 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: [Laboratoire Reactions et Genie des Procedes (LRGP), Nancy-University, CNRS, 1 rue Grandville, 54001 Nancy Cedex (France)


    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.

  11. Ideas in Context and the Idea of Renaissance Philosophy. (United States)

    Celenza, Christopher S


    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.

  12. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance (United States)

    Edwards, Howell G. M.


    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.

  13. Analytical Raman spectroscopic discrimination between yellow pigments of the Renaissance. (United States)

    Edwards, Howell G M


    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. 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: [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: [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, C13, DE-21335 Lüneburg (Germany)


    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.

  15. Iridium Cyclometalated Complexes in Host-Guest Chemistry: A Strategy for Maximizing Quantum Yield in Aqueous Media. (United States)

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


    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.

  16. Enhancement of a novel extracellular uricase production by media optimization and partial purification by aqueous three-phase system. (United States)

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


    Uricase (urate: oxygen oxidoreductase, EC, 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.

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


    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

  18. 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.


    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.

  19. 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)


    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.

  20. Surface modification of imprinted polymer microspheres with ultrathin hydrophilic shells to improve selective recognition of glutathione in aqueous media. (United States)

    Song, Renyuan; Hu, Xiaoling; Guan, Ping; Li, Ji; Du, Chunbao; Qian, Liwei; Wang, Chaoli


    A universal, effective approach addressing the classical limitations of hydrophobic molecularly imprinted polymer (MIP) microspheres was described. Two water-compatible MIP microspheres with ultrathin hydrophilic shells were synthesized by controllable surface-graft polymerization using a charged monomer (methacrylic acid) and uncharged monomer (N-isopropylacrylamide) as the hydrophilic functional monomers for the recognition of glutathione in the aqueous medium. The morphological and chemical characteristics of the as-prepared water-compatible MIP microspheres were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy and contact angle measurements. Their selective recognition properties were investigated by static binding tests and compared with those of the ungrafted MIP microspheres. The results of this study showed that the both as-prepared water-compatible MIP microspheres effectively decreased non-specific binding and enhanced the imprinting factor significantly, and the water-compatible MIP microspheres prepared using N-isopropylacrylamide as monomer exhibited a more remarkable recognition property. In addition, the thickness of surface-grafted hydrophilic layer was well controlled by adjusting the irradiation time to obtain the excellent recognition property. Finally, the applicability of the as-prepared water-compatible MIP microspheres as solid-phase extraction materials was investigated by competitive binding tests using a mixture of glutathione and its analogs.


    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


    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.

  2. Removal of graphene oxide nanomaterials from aqueous media via coagulation: Effects of water chemistry and natural organic matter. (United States)

    Duan, Lin; Hao, Rongjie; Xu, Zhu; He, Xizhen; Adeleye, Adeyemi S; Li, Yao


    With the increasing use of graphene oxide (GO) nanomaterials, its possible environmental release and human effects have received much attention. As GO may enter drinking or wastewater treatment systems like other carbonaceous nanomaterials, and have potential impact on human and/or environmental health, its removal efficiency during water treatment is important and requires investigation. In this study, the removal efficiency of GO during water treatment procedure via coagulation was evaluated, and the effects of solution chemistry and natural organic matter on the coagulation-based removal of GO nanomaterials were investigated. The results indicate that the removal efficiency of GO with alum coagulation can reach 80% with 20 mg/L alum dosage at neutral pH, and will not change significantly with higher concentration of alum. The coagulation mechanism and efficiency were strongly affected by the Al species in aqueous phase, which are controlled by pH. Co-existing cations (e.g. Na) may have minimal effect on GO removal efficiency, and the presence of humic acid (HA) suppresses coagulation remarkably at alum concentrations below 40 mg/L. The results from this study provide critical information for predicting the removal efficiency of GO nanomaterials during alum coagulation phase of water treatment procedure.

  3. 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


    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.

  4. A comparative study of semiconductor photocatalysts for hydrogen production by visible light using different sacrificial substrates in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Sabate, J.; Cervera-March, S.; Simarro, R.; Gimenez, J. (Barcelona Univ. (ES). Dept. of Chemical Engineering)


    Different semiconductor photocatalytic systems to produce H{sub 2} by visible light have been tested: (1) Pt/TiO{sub 2} plus sensitizers like Ru(bipy){sub 3}{sup 2+} and RuL{sub 3}{sup 2+} (L = 2,2'-bipyridine-4,4'dicarboxylate), (2) naked CdS, Pt/CdS and RuO{sub 2}/CdS, and (3) mixtures of CdS + Pt/TiO{sub 2}, and CdS and ZnS coprecipitated on {gamma}-Al{sub 2}O{sub 3}. EDTA, isopropanol, sulfide and sulfide/sulfite mixtures were used as sacrificial agents. The photocatalytic systems which used sensitizers showed a poor stability and they only produced H{sub 2} when EDTA was used as sacrificial agent. The mixture CdS + Pt/TiO{sub 2} gave the highest reaction rates for H{sub 2} production in isopropanol medium, and CdS, naked or with Pt deposits, produced the best results when sulfide or sulfide/sulfite as sacrificial agents were used. The addition of sulfite to a sulfide aqueous solution increased the H{sub 2} production rate about four times with respect to the case when only sulfide was employed. The maximum photochemical and energy efficiencies obtained were 13.2 and 5.0%, respectively, with reference to the wavelength range 300-520 nm. (author).

  5. Surface modification of imprinted polymer microspheres with ultrathin hydrophilic shells to improve selective recognition of glutathione in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Song, Renyuan, E-mail:; Hu, Xiaoling; Guan, Ping; Li, Ji; Du, Chunbao; Qian, Liwei; Wang, Chaoli


    A universal, effective approach addressing the classical limitations of hydrophobic molecularly imprinted polymer (MIP) microspheres was described. Two water-compatible MIP microspheres with ultrathin hydrophilic shells were synthesized by controllable surface-graft polymerization using a charged monomer (methacrylic acid) and uncharged monomer (N-isopropylacrylamide) as the hydrophilic functional monomers for the recognition of glutathione in the aqueous medium. The morphological and chemical characteristics of the as-prepared water-compatible MIP microspheres were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy and contact angle measurements. Their selective recognition properties were investigated by static binding tests and compared with those of the ungrafted MIP microspheres. The results of this study showed that the both as-prepared water-compatible MIP microspheres effectively decreased non-specific binding and enhanced the imprinting factor significantly, and the water-compatible MIP microspheres prepared using N-isopropylacrylamide as monomer exhibited a more remarkable recognition property. In addition, the thickness of surface-grafted hydrophilic layer was well controlled by adjusting the irradiation time to obtain the excellent recognition property. Finally, the applicability of the as-prepared water-compatible MIP microspheres as solid-phase extraction materials was investigated by competitive binding tests using a mixture of glutathione and its analogs. - Highlights: • Ultrathin hydrophilic shell was synthesized by controllable SIP approach. • Low nonspecific binding, high imprinting factor and selectivity were achieved. • Value of imprinting factor was controlled by adjusting irradiation time. • Selective solid-phase extraction of glutathione from a mixed solution of peptides.

  6. Nitrogen-Doped Porous Carbons from Ionic Liquids@MOF: Remarkable Adsorbents for Both Aqueous and Nonaqueous Media. (United States)

    Ahmed, Imteaz; Panja, Tandra; Khan, Nazmul Abedin; Sarker, Mithun; Yu, Jong-Sung; Jhung, Sung Hwa


    Porous carbons were prepared from a metal-organic framework (MOF, named ZIF-8), with or without modification, via high-temperature pyrolysis. Porous carbons with high nitrogen content were obtained from the calcination of MOF after introducing an ionic liquid (IL) (IL@MOF) via the ship-in-bottle method. The MOF-derived carbons (MDCs) and IL@MOF-derived carbons (IMDCs) were characterized using various techniques and used for liquid-phase adsorptions in both water and hydrocarbon to understand the possible applications in purification of water and fuel, respectively. Adsorptive performances for the removal of organic contaminants, atrazine (ATZ), diuron, and diclofenac, were remarkably enhanced with the modification/conversion of MOFs to MDC and IMDC. For example, in the case of ATZ adsorption, the maximum adsorption capacity of IMDC (Q0 = 208 m(2)/g) was much higher than that of activated carbon (AC, Q0 = 60 m(2)/g) and MDC (Q0 = 168 m(2)/g) and was found to be the highest among the reported results so far. The results of adsorptive denitrogenation and desulfurization of fuel were similar to that of water purification. The IMDCs are very useful in the adsorptions since these new carbons showed remarkable performances in both the aqueous and nonaqueous phases. These results are very meaningful because hydrophobic and hydrophilic adsorbents are usually required for the adsorptions in the water and fuel phases, respectively. Moreover, a plausible mechanism, H-bonding, was also suggested to explain the remarkable performance of the IMDCs in the adsorptions. Therefore, the IMDCs derived from IL@MOF might have various applications, especially in adsorptions, based on high porosity, mesoporosity, doped nitrogen, and functional groups.

  7. Future studies on electron scattering; a renaissance (United States)

    Mason, Nigel J.


    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.

  8. The Darker Side of the Renaissance

    Directory of Open Access Journals (Sweden)

    Walter Mignolo


    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


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


    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.


    Directory of Open Access Journals (Sweden)

    Angus GOWLAND


    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.

  11. Translation and Manipulation in Renaissance England

    Directory of Open Access Journals (Sweden)

    John Denton


    Full Text Available This supplementary volume to JEMS is part of an ongoing research project which began with a series of articles published by the author in the 1990s on the translation of Classical historical texts in Renaissance England. The methodology followed is that of Descriptive Translation Studies as developed by scholars such as Lefevere and Hermans with the accent on manipulation of the source text in line with the ideological stance of the translator and the need to ensure that readers of the translation received the ‘correct’ moral lessons.  Particular attention is devoted to a case study of the strategies followed in Thomas North’s domesticating English translation of Jacques Amyot’s French translation of Plutarch’s Lives and the consequences for Shakespeare’s perception of Plutarch.Biography John Denton was associate professor of English Language and Translation at the University of Florence until retirement in 2015. He  has published on contrastive analysis, history of translation (with special reference to the Early Modern England, religious discourse, literary and audiovisual translation. 

  12. Drivers for the renaissance of coal. (United States)

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


    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.

  13. Dye-sensitized solar cells based on thick highly ordered TiO(2) nanotubes produced by controlled anodic oxidation in non-aqueous electrolytic media. (United States)

    Stergiopoulos, T; Ghicov, A; Likodimos, V; Tsoukleris, D S; Kunze, J; Schmuki, P; Falaras, P


    Dye-sensitized solar cells (DSSCs) were prepared using TiO(2) nanotubes, grown by controlled Ti anodic oxidation in non-aqueous media. Smooth, vertically oriented TiO(2) 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 TiO(2) crystalline phase upon post-annealing in air at 450 °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.

  14. Aspects on the catalysis of lipase from porcine pancreas (type VI-s in aqueous media: development of ion-pairs

    Directory of Open Access Journals (Sweden)

    Marina Kokkinou


    Full Text Available This article reports a first contribution for the elucidation of catalytic mechanism of Lipase from porcine pancreas, type VI-s (PPL, in hydrolyzing an ester substrate in aqueous media. The conclusions were based on the pH-profiles of Michaelis-Menten parameters k cat/Km, k cat and Km, as well as on the absolute temperature profile of k cat/Km, obtained during the hydrolysis of p-nitrophenyl laurate by PPL. It was found that (a PPL performs catalysis by means of ion pairs formed either as Ser152-Ο-/His263-Im+H and/or Carbonyl-Ο-/His263-Im+H, (b the parameter k cat/Km equals to k1 and thus ES is formed and destroyed in the course of a series of consecutive reactions governed by the dynamic constant K S = k2/k1, and (c the hydrolysis of substrate is assisted by a hydrogen bond developed between deprotonated Asp176 and the positively charged imidazole of His263 across a pKa-value 3.85, necessary for efficient catalysis.

  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. (United States)

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


    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. 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? (United States)

    Demetzos, Costas; Pippa, Natassa


    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.

  17. Modified Rice Straw as Adsorbent Material to Remove Aflatoxin B1 from Aqueous Media and as a Fiber Source in Fino Bread. (United States)

    Mohamed, Sherif R; El-Desouky, Tarek A; Hussein, Ahmed M S; Mohamed, Sherif S; Naguib, Khayria M


    The aims of the current work are in large part the benefit of rice straw to be used as adsorbent material and natural source of fiber in Fino bread. The rice straw was subjected to high temperature for modification process and the chemical composition was carried out and the native rice straw contained about 41.15% cellulose, 20.46% hemicellulose, and 3.91% lignin while modified rice straw has 42.10, 8.65, and 5.81%, respectively. The alkali number was tested and showed an increase in the alkali consumption due to the modification process. The different concentrations of modified rice straw, aflatoxin B1, and pH were tested for removal of aflatoxin B1 from aqueous media and the maximum best removal was at 5% modified rice straw, 5 ng/mL aflatoxin B1, and pH 7. The modified rice straw was added to Fino bread at a level of 5, 10, and 15% and the chemical, rheological, baking quality, staling, and sensory properties were studied. Modified rice straw induced an increase of the shelf life and the produced Fino bread has a better consistency.

  18. Comparison of antibacterial activity of Ag nanoparticles synthesized from leaf extract of Parthenium hystrophorus L in aqueous media and Gentamicin sulphate: in-vitro. (United States)

    Anwar, Mohammad F; Yadav, Deepak; Kapoor, Sumeet; Chander, Jagdish; Samim, Mohd


    Monodisperse silver (Ag) nanoparticles were synthesized by using Parthenium hystrophorus L leaf extract in aqueous media. The synthesized nanoparticles were characterized by using UV-vis spectrophotometer, X-ray diffracto-meter (XRD), transmission electron microscope (TEM), and dynamics light scattering (DLS). Size-dependent antibacterial activities of Ag nanoparticles were tested against Gram negative Pseudomonas aeruginosa and Gram positive Staphylococcus aureus. Ag nanoparticles having 20 ± 2 nm size in diameter show maximum zone of inhibition (23 ± 2.2 mm) in comparison to 40 nm and 70 nm diameter nanoparticles for Pseudomonas aeruginosa. The zone of inhibition against Staphylococcus aureus were 19 ± 1.8 mm, 15 ± 1.5 mm and 11 ± 1 mm for 20 nm, 40 nm, and 70 nm, respectively. In addition, affect of concentration of 20 nm size Ag nanoparticles on Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus species were also reported and results were compared with 10 µg/ml dose of Gentamicin sulphate. The Parthenium hystrophorus L leaf extract capped 20 ± 2 nm Ag nanoparticles (7.5 µg/ml) shows statistically significant antibacterial activity than Gentamicin sulphate (10 µg/ml) against Staphylococcus aureus.

  19. One-pot fabrication of FRET-based fluorescent probe for detecting copper ion and sulfide anion in 100% aqueous media (United States)

    Lv, Kun; Chen, Jian; Wang, Hong; Zhang, Peisheng; Yu, Maolin; Long, Yunfei; Yi, Pinggui


    The design of effective tools for detecting copper ion (Cu2 +) and sulfide anion (S2 -) is of great importance due to the abnormal level of Cu2 + and S2 - has been associated with an increase in risk of many diseases. Herein, we report on the fabrication of fluorescence resonance energy transfer (FRET) based fluorescent probe PF (PEI-FITC) for detecting Cu2 + and S2 - in 100% aqueous media via a facile one-pot method by covalent linking fluorescein isothiocyanate (FITC) with branched-polyethylenimine (b-PEI). PF could selectively coordinate with Cu2 + among 10 metal ions to form PF-Cu2 + complex, resulting in fluorescence quenching through FRET mechanism. Furthermore, the in situ generated PF-Cu2 + complex can be used to selectively detect S2 - based on the displacement approach, resulting in an off-on type sensing. There is no obvious interference from other anions, such as Cl-, NO3-, ClO4-, SO42 -, HCO3-, CO32 -, Br-, HPO42 -, F- and S2O32 -. In addition, PF was successfully used to determine Cu2 + and S2 - in human serum and tap water samples. Therefore, the FRET-based probe PF may provide a new method for selective detection of multifarious analysts in biological and environmental applications, and even hold promise for application in more complicated systems.

  20. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method (United States)

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


    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.

  1. 78 FR 68134 - Culturally Significant Objects Imported for Exhibition Determinations: “Renaissance to Goya... (United States)


    ... 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...

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


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

    Institute of Scientific and Technical Information of China (English)



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

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

    Directory of Open Access Journals (Sweden)

    Rembrandt Duits


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

  5. The first translations of Harlem renaissance poetry in Slovenia

    Directory of Open Access Journals (Sweden)

    Jerneja Petrič


    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. Brain, mind, and body: interactions with art in renaissance Italy. (United States)

    Ginn, Sheryl R; Lorusso, Lorenzo


    The Renaissance saw the first systematic anatomical and physiological studies of the brain and human body because scientists, for the first time in centuries, were allowed to dissect human bodies for study. Renaissance artists were frequently found at dissections and their attention to detail can be observed in their products. Scientists themselves were increasingly artistic, and they created astonishing anatomical models and illustrations that can still be studied. The cross-fertilization of art and science in the Renaissance resulted in more scientific analyses of neuroanatomy as well as more creative ways in which such analyses could be depicted. Both art and science benefited from the reciprocal ways in which the two influenced each other even as they provided new ways of explaining the mysteries of the human body and mind.

  7. 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. (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


    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

  8. 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:


    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.

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

    Shaker, Medhat A; Yakout, Amr A


    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.

  10. 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


    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

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

    DEFF Research Database (Denmark)

    Pedersen, Poul


    , 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...

  12. Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report (United States)

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


    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…

  13. Rediscovering Renaissance Research: Information Literacy Strategies for Success (United States)

    Gilchrist, Sarah Burns


    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…

  14. Peace parks in Southern Africa: bringers of an African Renaissance?

    NARCIS (Netherlands)

    H.C. Buscher


    textabstractThe pursuit of an African Renaissance has become an important aspect of regional cooperation between South Africa and its neighbours. Transfrontier conservation areas, or ‘Peace Parks’ as they are popularly called, have been identified as key instruments to promote the African Renaissanc

  15. A Brief Historical Development of Classical Mathematics before the Renaissance (United States)

    Debnath, Lokenath


    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,…

  16. Media for Reflection

    DEFF Research Database (Denmark)

    Knudsen, Morten


    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....

  17. Jean-Pierre Luminet: Renaissance Communicator (United States)

    Pullen, L.; Russo, P.


    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.

  18. Solvent effects on a Diels-Alder reaction involving a cationic diene: Consequences of the absence of hydrogen-bond interactions for accelerations in aqueous media

    NARCIS (Netherlands)

    van der Wel, Gerben K.; Wijnen, Jan W.; Engberts, Jan B.F.N.


    In order to study the influence of hydrogen-bond interactions on the accelerations of Diels-Alder reactions in water and highly aqueous mixed solvent systems, second-order rate constants for the Diels-Alder reaction of acridizinium bromide (1a) with cyclopentadiene (CP) have been measured in aqueous

  19. Solvent effects on a Diels-Alder reaction involving a cationic diene : Consequences of the absence of hydrogen-bond interactions for accelerations in aqueous media

    NARCIS (Netherlands)

    Wel, Gerben K. van der; Wijnen, Jan W.; Engberts, Jan B.F.N.


    In order to study the influence of hydrogen-bond interactions on the accelerations of Diels-Alder reactions in water and highly aqueous mixed solvent systems, second-order rate constants for the Diels-Alder reaction of acridizinium bromide (1a) with cyclopentadiene (CP) have been measured in aqueous

  20. New Insight into the Cosmic Renaissance Epoch (United States)


    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

  1. BOOK REVIEW: Galileo's Muse: Renaissance Mathematics and the Arts (United States)

    Peterson, Mark; Sterken, Christiaan


    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

  2. 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. (United States)

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


    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.

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

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


    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 530 nm 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.

  4. Reconstruction of skull defects in the middle ages and renaissance. (United States)

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


    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.

  5. The Influence of the Renaissance on Richard Hooker

    Directory of Open Access Journals (Sweden)

    Grislis Egil


    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.

  6. Théâtre de la Renaissance I


    Wild, Nicole


    Du 8 novembre 1838 jusqu’au 2 mai 1840, et à nouveau du 26 janvier au 16 mai 1841, Anténor Joly donne à l’entreprise qu’il inaugure salle Ventadour l’appellation de Théâtre de la Renaissance. Il fait représenter des drames, des comédies et des vaudevilles, ainsi que des « opéras de genre ». ZINGARO Opéra en 2 actes de Thomas Sauvage. Musique d’Uranio Fontana. Créé au Th. de la Renaissance (salle Ventadour) en 1840 1. Une maquette de costume par Saint-Ange Aquarelle préparatoire à la gravure. ...

  7. The Influence of Renaissance On Marvel Comics Movies

    Institute of Scientific and Technical Information of China (English)



    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.


    Directory of Open Access Journals (Sweden)

    Michael Landry


    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.

  9. The "Renaissance Child": High Achievement and Gender in Late Modernity (United States)

    Skelton, Christine; Francis, Becky


    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…

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

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, J.


    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)

  11. Joyful Miss: Gendered Perspectives on Marriage in Renaissance Italy


    Madrigal, Melina Rae


    My dissertation investigates the convoluted layers comprising profeminist and misogynist precepts through the optic of marriage during the Renaissance period, particularly the Cinque- and early Seicento. My specific intention is to overturn some commonly held beliefs about each respective ideology and in the process unveil how tightly woven together they are, for their divergences are transparent but their points of convergence and overlap are less so. In fact, while many studies, such as P...

  12. Truth and Fibble-Fable in Renaissance Satire

    Directory of Open Access Journals (Sweden)

    Branko Madžarevič


    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.

  13. Nuclear Operations Excellence: A Foundation for the Renaissance

    Energy Technology Data Exchange (ETDEWEB)

    Gex, P. [American Nuclear Society (United States); Luanco, E. [Ventyx France, Immeuble Central Gare, 1, Place Charles de Gaulle, 78180 Montigny Le Bretonneux (France)


    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

  14. The political uses of astrology: predicting the illness and death of princes, kings and popes in the Italian Renaissance. (United States)

    Azzolini, Monica


    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.


    NARCIS (Netherlands)



    The importance of solvation in determining substituent effects of alkyl groups has been assessed in a quantitative study of the medium effects of ethanol and 1-propanol on the neutral hydrolysis of 18 1-acyl-(3-substituted)-1,2,4-triazoles in highly aqueous solutions. The dependence of the pseudo-fi

  16. Program Fidelity and Teacher Decisions: A Case Study of the Renaissance Learning Program (United States)

    Putnam, Jennifer D.


    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…

  17. What Works Clearinghouse Quick Review: "Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report" (United States)

    What Works Clearinghouse, 2012


    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…

  18. From Accountability to Privatization and African American Exclusion: Chicago's "Renaissance 2010" (United States)

    Lipman, Pauline; Haines, Nathan


    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…

  19. The University of New Brunswick's Renaissance College: Curricular Evolution and Assessment at the Faculty Level (United States)

    Zundel, Pierre; Mengel, Thomas


    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…

  20. 75 FR 61232 - RIEF RMP LLC and Renaissance Technologies LLC; Notice of Application (United States)


    ... 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,...

  1. 75 FR 55613 - General Motors Corporation, Renaissance Center, Including On-Site Leased Workers From Accretive... (United States)


    ... 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...

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


    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…

  3. The Renaissance Engineer: Educating Engineers in a Post-9/11 World. (United States)

    Akay, Adnan


    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)

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

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


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

  5. The Renaissance Culture and the Arts. Grades 3-6, The Time Traveler Series. (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;…


    Directory of Open Access Journals (Sweden)

    I Komang Sudirga


    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.

  7. Utopia e Educacao no Renascimento (Utopia and Education in the Renaissance). (United States)

    da Silva, Joao Carlos


    Discusses education in utopian ideas of the Renaissance, privileging Thomas More's "Utopia," Tommaso Campanella's "City of the Sun," and Francis Bacon's "Nova Atlantis." Analyzes the importance Renaissance utopian thinkers had in the process of the construction of modern educational thinking, explaining how these…

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

    Energy Technology Data Exchange (ETDEWEB)

    Carelli, J.; Aycart, J.


    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)

  9. Anatomy and the Body in Renaissance Protestant Psychology. (United States)

    Cellamare, Davide


    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.

  10. Cultural Critique and Cultural Orthodoxy in Two Renaissance Plays

    Directory of Open Access Journals (Sweden)

    Akram Shalghin


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

  11. The Renaissance academies between science and the humanities. (United States)

    McNeely, Ian F


    The scientific academies of early modern Europe have long been recognized for their critical role in incubating and legitimating the Scientific Revolution. So also, academies dedicated to vernacular literature and language, opera and ballet, art and design, and speculative philosophy all contributed greatly to the emergence of new humanistic art forms. Rarely, though, have scholars asked whether a common institutional culture united the scientific and humanistic academies across disciplinary divides that "Renaissance men" famously refused to acknowledge. This essay, an interdisciplinary synthesis of existing scholarship, attempts just that, discerning a move toward practices of "objectivity" across the entire academy movement.

  12. 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.


    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.

  13. 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


    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.

  14. Foot deformities in Renaissance paintings. A mystery of symbolism, artistic licence, illusion and true representation in five renowned Renaissance painters. (United States)

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


    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.

  15. Breastfeeding and weaning in renaissance Italy: the Medici children. (United States)

    Giuffra, Valentina; Fornaciari, Gino


    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.

  16. On Architectural Practice and Arithmetic Abilities in Renaissance Italy

    Directory of Open Access Journals (Sweden)

    Giulia Ceriani Sebregondi


    Full Text Available The article examines the figure of the architect at work in Renaissance Italy, when a major change occurred in the practice of design with the spread of arithmetic. This deep scientific, technical, methodological, and cultural shift involved the image of the architect and his profession, his relationship with the patron, as well as the cultural conception of architecture. The essay, crossing disciplinary boundaries, analyses some technical aspects of architectural design in early modern Italy only marginally investigated. If proportional systems and architecture’s theoretical questions have been amply studied, the practical culture, the daily professional practice and its working tools, such as the operative arithmetic actually known to architects, have been only sporadically analysed. During the Renaissance, especially in Italy, an important development of mathematics occurred and arithmetic was clarified and simplified so to allow its diffusion, but at the same time those disciplines remained essentially despised by aristocratic and intellectual elites. What was the architects’ role in this moment of deep change? Which was the arithmetic usually employed by them in the design process? When did Hindu-Arabic numbers and fractions became familiar in the field of architecture? In the secular battle between geometry and arithmetic, which system was used in what professional cases? The essay illustrates how architects with different backgrounds responded to this change, through a comparative analysis of all the architectural drawings containing numbers and calculations made by Michelangelo Buonarroti (1475–1564, Baldassarre Peruzzi (1481–1536, and Antonio da Sangallo the Younger (1484–1546.

  17. The Nuclear Renaissance — Implications on Quantitative Nondestructive Evaluations (United States)

    Matzie, Regis A.


    The world demand for energy is growing rapidly, particularly in developing countries that are trying to raise the standard of living for billions of people, many of whom do not even have access to electricity. With this increased energy demand and the high and volatile price of fossil fuels, nuclear energy is experiencing resurgence. This so-called nuclear renaissance is broad based, reaching across Asia, the United States, Europe, as well as selected countries in Africa and South America. Some countries, such as Italy, that have actually turned away from nuclear energy are reconsidering the advisability of this design. This renaissance provides the opportunity to deploy more advanced reactor designs that are operating today, with improved safety, economy, and operations. In this keynote address, I will briefly present three such advanced reactor designs in whose development Westinghouse is participating. These designs include the advanced passive PWR, AP1000, which recently received design certification for the US Nuclear Regulatory Commission; the Pebble Bed Modular reactor (PBMR) which is being demonstrated in South Africa; and the International Reactor Innovative and Secure (IRIS), which was showcased in the US Department of Energy's recently announced Global Nuclear Energy Partnership (GNEP), program. The salient features of these designs that impact future requirements on quantitative nondestructive evaluations will be discussed. Such features as reactor vessel materials, operating temperature regimes, and new geometric configurations will be described, and mention will be made of the impact on quantitative nondestructive evaluation (NDE) approaches.

  18. Sappho's shifting fortunes from antiquity to the early Renaissance. (United States)

    Penrose, Walter


    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.

  19. Self-aggregation of ionic liquid 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [C{sub 4}mmim][BF{sub 4}] in aqueous media: A conductometric, volumetric and spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Amalendu, E-mail:; Pillania, Ankita


    Highlights: • Self-aggregation behaviour of [C{sub 4}mmim][BF{sub 4}] has been studied using various techniques. • Thermodynamic parameters showing aggregation is an entropy-driven process. • Volumetric analysis indicates aggregation is influenced by solute–solvent interactions. • {sup 1}H NMR revealed formation of loosely bound aggregates in the system. - Abstract: Aggregation behaviour of ionic liquid (IL), 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, [C{sub 4}mmim][BF{sub 4}] in aqueous media has been studied by electrical conductivity, density and speed of sound measurements across temperature range (288.15–308.15) K. The critical aggregation concentration (cac), the standard Gibb’s free energy of aggregation, ΔG°{sub agg}, adiabatic compressibility, β{sub S} and changes in the adiabatic compressibility upon aggregation, Δβ{sub S,agg} for the IL in aqueous solution have been derived from the experimental data. Further to get the deeper insights into the aggregation process spectroscopic study using {sup 1}H NMR measurements have been carried out. The aggregation behaviour observed from conductance and volumetric approaches has been found to be in good agreement with each other. NMR study revealed the formation of loosely bound ion associates as aggregates in the system upon aggregation.

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

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


    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).

  1. The effect of solvent on the kinetics of the oxidation of 3-methyl-2,6-diphenyl-piperidin-4-one by quinolinium fluorochromate in aqueous organic media

    Directory of Open Access Journals (Sweden)



    Full Text Available The kinetics of the oxidation of 3-methyl-2,6-diphenyl-piperidin-4-one by quinolinium fluorochromate (QFC have been investigated in aqueous solutions of dimethyl sulphoxide, 1,4-dioxane, tert-butanol and acetone. The influence of the added co-solvent on the reactivity were analysed in the light of various simple and multiple regression equations, viz the Laidler-Eyring, Grunwald-Winstein, Swain and Kamlet-Taft equations. The obtained results showed that the solvation phenomenon plays a dominant role on the reactivity.

  2. Robust Colloidal Nanoparticles of Pyrrolopyrrole Cyanine J-Aggregates with Bright Near-Infrared Fluorescence in Aqueous Media: From Spectral Tailoring to Bioimaging Applications. (United States)

    Yang, Cangjie; Wang, Xiaochen; Wang, Mingfeng; Xu, Keming; Xu, Chenjie


    Colloidal nanoparticles (NPs) containing near-infrared-fluorescent J-aggregates (JAGGs) of pyrrolopyrrole cyanines (PPcys) stabilized by amphiphilic block co-polymers were prepared in aqueous medium. JAGG formation can be tuned by means of the chemical structure of PPcys, the concentration of chromophores inside the polymeric NPs, and ultrasonication. The JAGG NPs exhibit a narrow emission band at 773 nm, a fluorescence quantum yield comparable to that of indocyanine green, and significantly enhanced photostability, which is ideal for long-term bioimaging.

  3. Kinetics and mechanism of OsOsub(4) catalyzed oxidation of chalcones by Cesub(4) in aqueous acetic sulfuric acid media

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasulu, P.V.; Adinarayana, M.; Sethuram, B.; Rao, T.N. (Osmania Univ., Hyderabad (India). Dept. of Chemistry)


    Kinetics of OsOsub(4) catalyzed oxidation of chalcones by Cesup(4+) was studied in aqueous acetic-sulfuric acid medium in the temperature range 313 to 338 K. The order in oxidant is zero while the order with respect to substrate and catalyst are each fractional. The rate of the reaction decreased with increase in percentage of acetic acid while (Hsup(+)) had practically no effect on the rate. The rates of various substituted chalcones are given. A mechanism in which formation of a cyclic ester between chalcone and OsOsub(4) in a fast step followed by its decomposition in a rate-determining step is envisaged.

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

    Directory of Open Access Journals (Sweden)

    Drozdova Yuliya


    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

  5. Synergistic Effect of Atmospheric-pressure Plasma and TiO2 Photocatalysis on Inactivation of Escherichia coli Cells in Aqueous Media (United States)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Li, Jiangwei; Wang, Xingquan; Chen, Qiang; Yang, Size; Chen, Zhong; Bazaka, Kateryna; (Ken) Ostrikov, Kostya


    Atmospheric-pressure plasma and TiO2 photocatalysis have been widely investigated separately for the management and reduction of microorganisms in aqueous solutions. In this paper, the two methods were combined in order to achieve a more profound understanding of their interactions in disinfection of water contaminated by Escherichia coli. Under water discharges carried out by microplasma jet arrays can result in a rapid inactivation of E. coli cells. The inactivation efficiency is largely dependent on the feed gases used, the plasma treatment time, and the discharge power. Compared to atmospheric-pressure N2, He and air microplasma arrays, O2 microplasma had the highest activity against E. coli cells in aqueous solution, and showed >99.9% bacterial inactivation efficiency within 4 min. Addition of TiO2 photocatalytic film to the plasma discharge reactor significantly enhanced the inactivation efficiency of the O2 microplasma system, decreasing the time required to achieve 99.9% killing of E. coli cells to 1 min. This may be attributed to the enhancement of ROS generation due to high catalytic activity and stability of the TiO2 photocatalyst in the combined plasma-TiO2 systems. Present work demonstrated the synergistic effect of the two agents, which can be correlated in order to maximize treatment efficiency. PMID:28004829

  6. Functionalized CMK-3 mesoporous carbon with 2-amino-5-mercapto-1,3,4-thiadiazole for Hg(II) removal from aqueous media. (United States)

    Anbia, Mansoor; Dehghan, Roghaye


    Ordered mesoporous carbon (CMK-3) was synthesized and functionalized with 2-amino-5-mercapto-1,3,4-thiadiazole groups (AMT-OCMK-3) for Hg(II) removal from aqueous solution. The modified CMK-3 was characterized by X-ray diffraction, N2 adsorption-desorption isotherm, scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of solution pH, contact time, initial Hg(II) concentration and matrix effect were studied. The adsorption data were successfully fitted with the Langmuir model, exhibiting high adsorption capacity of 450.45 mg/g of AMT-OCMK-3. In the solid-phase extraction system a series of experimental parameters such as sample flow rate, sample volume, eluent volume and concentration of the eluent solution have been investigated and established for preconcentration of Hg(II) in aqueous solution. The results showed that the enrichment factor for Hg(II) was 250, the precision (relative standard deviation (RSD), %) for six replicate measurements was 2.05% and the limit of detection for Hg(II) was achieved at 0.17 μg/L.

  7. Synergistic Effect of Atmospheric-pressure Plasma and TiO2 Photocatalysis on Inactivation of Escherichia coli Cells in Aqueous Media (United States)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Li, Jiangwei; Wang, Xingquan; Chen, Qiang; Yang, Size; Chen, Zhong; Bazaka, Kateryna; (Ken) Ostrikov, Kostya


    Atmospheric-pressure plasma and TiO2 photocatalysis have been widely investigated separately for the management and reduction of microorganisms in aqueous solutions. In this paper, the two methods were combined in order to achieve a more profound understanding of their interactions in disinfection of water contaminated by Escherichia coli. Under water discharges carried out by microplasma jet arrays can result in a rapid inactivation of E. coli cells. The inactivation efficiency is largely dependent on the feed gases used, the plasma treatment time, and the discharge power. Compared to atmospheric-pressure N2, He and air microplasma arrays, O2 microplasma had the highest activity against E. coli cells in aqueous solution, and showed >99.9% bacterial inactivation efficiency within 4 min. Addition of TiO2 photocatalytic film to the plasma discharge reactor significantly enhanced the inactivation efficiency of the O2 microplasma system, decreasing the time required to achieve 99.9% killing of E. coli cells to 1 min. This may be attributed to the enhancement of ROS generation due to high catalytic activity and stability of the TiO2 photocatalyst in the combined plasma-TiO2 systems. Present work demonstrated the synergistic effect of the two agents, which can be correlated in order to maximize treatment efficiency.

  8. The Renaissance and the universal surgeon: Giovanni Andrea Della Croce, a master of traumatology. (United States)

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


    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.

  9. 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


    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.

  10. Complete Transmetalation in a Metal-Organic Framework by Metal Ion Metathesis in a Single Crystal for Selective Sensing of Phosphate Ions in Aqueous Media. (United States)

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


    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.

  11. 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


    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.

  12. Synthesis of pure colloidal silver nanoparticles with high electroconductivity for printed electronic circuits: the effect of amines on their formation in aqueous media. (United States)

    Natsuki, Jun; Abe, Takao


    This paper describes a practical and convenient method to prepare stable colloidal silver nanoparticles for use in printed electronic circuits. The method uses a dispersant and two kinds of reducing agents including 2-(dimethylamino) ethanol (DMAE), which play important roles in the reduction of silver ions in an aqueous medium. The effect of DMAE and dispersant, as well as the factors affecting particle size and morphology are investigated. In the formation of the silver nanoparticles, reduction occurs rapidly at room temperature and the silver particles can be separated easily from the mixture in a short time. In addition, organic solvents are not used. Pure, small and relatively uniform particles with a diameter less than 10 nm can be obtained that exhibit high electroconductivity. The silver nanoparticles are stable, and can be isolated as a dried powder that can be fully redispersed in deionized water. This method of producing colloidal silver nanoparticles will find practical use in electronics applications.

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

    DEFF Research Database (Denmark)

    Shaw, Timothy Milton


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

  14. A scholarly intermediary between the Ottoman Empire and Renaissance Europe. (United States)

    Morrison, Robert


    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.

  15. History of allergy in the middle ages and renaissance. (United States)

    Ring, Johannes


    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.

  16. Raman spectroscopic study of "The Malatesta": a Renaissance painting? (United States)

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


    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.

  17. Ethiopia's Grand Renaissance Dam: Implications for Downstream Riparian Countries (United States)

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


    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.

  18. Renaissance of immunosuppressive therapy in the new millennium. (United States)

    Kahan, B D


    Immunosuppression in the next millennium will be based not merely on the survival of the patient and his graft, but more importantly on regimens that optimize the "Three C's": Co-morbidity, Cost, and Convenience. To meet these goals, the field of transplantation urgently requires new technologies: both new scientific tools of drug design, testing, and implementation, and informational tools including a categorical database and theoretical models to answer specific therapeutic questions. Just as the Renaissance marked a renewed interest in man himself after an age of Medieval spiritualism, so too will transplantation need to address the unique concerns of each patient to achieve an optimal outcome that includes self-reliance and the desired "texture of life." In weaving our tapestry for the 21st century, we must meet these challenges not merely with the 20th century tools at hand but with a strategic vision that searches for, readily adopts, and effectively harnesses unique technology.

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

    CERN Document Server


    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.

  20. 未来的Renaissance Schaumburg电缆

    Institute of Scientific and Technical Information of China (English)


    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.”

  1. 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. (United States)

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


    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.

  2. Modeling seismic stimulation: Enhanced non-aqueous fluid extraction from saturated porous media under pore-pressure pulsing at low frequencies (United States)

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


    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.

  3. MS PHD'S Professional Development Program: A Scientific Renaissance in Cyberspace (United States)

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


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

  4. Batch adsorptive removal of Fe(III, Cu(II and Zn(II ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

    Directory of Open Access Journals (Sweden)

    Abdul-Aleem Soliman Aboul-Magd


    Full Text Available Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III, Cd(II, Zn(II, Cu(II, Mn(II, Mg(II, and Pb(II from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion concentration, different proportions of some organic solvents, H+-ion concentrations and reaction temperature on the partition coefficients. The metal adsorption for the cation exchanger was found to be significant in different media for both nitric and hydrochloric acids, i.e., the adsorption up take of metal ions presented in this work is very significant depending on the characteristics of ions and on the external concentrations of solute. The presence of low ionic strength or low concentration of acids does have a significant adsorption of metal ions on ion-exchange resin. The results show that the ion exchanger could be employed for the preconcentration, separation and the determination.

  5. Chicago's Renaissance 2010: Building on School Reform in the Age of Accountability (United States)

    Duncan, Arne


    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.

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

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


    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.

  7. Self and Other in the Renaissance: Laonikos Chalkokondyles and Late Byzantine Intellectuals


    Akisik, Aslihan


    The capture of Constantinople by the Ottoman armies of Mehmed II in 1453 was a cataclysmic event that reverberated throughout Renaissance Europe. This event intensified the exodus of Byzantines to Italy and beyond and they brought along with them the heritage of Greek antiquity. Laonikos Chalkokondyles contributed to the Renaissance with his detailed application of Herodotos to the fifteenth century, Apodeixis Historion, and made sense of the rise of the Ottomans with the lens of ancient hist...

  8. Synthesis and crystal structure of imidazole containing amide as a turn on fluorescent probe for nickel ion in aqueous media. An experimental and theoretical investigation (United States)

    Annaraj, B.; Mitu, L.; Neelakantan, M. A.


    Imidazole containing amide fluorescence probe (PAIC) for Ni2+ was designed and successfully synthesized in good yield by reaction between 1-methyl-1H-imidazole-2-carboxylic acid and L-phenylalanine methyl ester. The probe was characterized by FTIR, 1H NMR, ESI-MS, UV-vis and fluorescence spectroscopy. Single crystal XRD analysis reveals that PAIC crystallizes in a monoclinic crystal lattice system with the space group of P21/n. Chemosensor property of PAIC was tested against different metal ions by UV-vis and fluorescent techniques in aqueous medium. Test results show that PAIC has high selectivity for Ni2+ compared to other metal ions (Na+, K+, Ca2+, Ag+, Co2+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Zn2+ and Pb2+). Time-dependent density functional theory (TD-DFT) and configuration interaction singles (CIS) calculations were carried out to understand the sensing mechanism. The practical applicability of PAIC was tested in real water samples.

  9. Degradation of antidepressant drug fluoxetine in aqueous media by ozone/H2O2 system: process optimization using central composite design. (United States)

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


    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.

  10. Fluorometric selective detection of fluoride ions in aqueous media using Ag doped CdS/ZnS core/shell nanoparticles. (United States)

    Boxi, Siddhartha Sankar; Paria, Santanu


    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).

  11. The Renaissance Concept of Space: Notes on the Interaction between Arts and Sciences in History

    Directory of Open Access Journals (Sweden)

    Rein Undusk


    Full Text Available “Renaissance concept of space” harbors surely some definite bonuses for anybody embarking on a study of the inventive role that philosophy has had, in its happiest moments of life, for human cognition. First, the new suppositions related to physical space emerge in the Renaissance as derivative from the theological-philosophical assumptions of the era: what Renaissance space is can be enunciated quite convincingly on the basis of the intellectual collisions that the era was allotted to deal with. Thus, as a re-generator of classical culture, the Renaissance had to a degree dug up the finite substructure of ancient thinking; however, as an inheritor of the Middle Ages, it had been requested to square finitism with transcendency. Second, much of what we can today fit under Renaissance space is in fact delivered to us in the artistic form of painting, which means that, in addition to the challenge set by philosophy to the spatial knowledge of the era, there was postulated as well a mediatory agency of art in the realization and conveyance of this new knowledge. Thus we can suppose that the solution offered by Renaissance art to the problem of space on its fictional plane comprised the germ of some modern knowledge about space in reality.

  12. Development of a new colorimetric assay for detection of bisphenol-A in aqueous media using green synthesized silver chloride nanoparticles: experimental and theoretical study. (United States)

    Khalililaghab, Shiva; Momeni, Safieh; Farrokhnia, Maryam; Nabipour, Iraj; Karimi, Sadegh


    In the present study, a cost-effective, green and simple synthesis method was applied for preparation of stable silver chloride nanoparticles (AgCl-NPs). The method was done by forming AgCl-NPs from Ag(+) ions using aqueous extract of brown algae (Sargassum boveanum) obtained from the Persian Gulf Sea. This extract served as capping agent during the formation of AgCl-NPs. Creation of AgCl-NPs was confirmed by UV-visible spectroscopy, powder X-ray diffraction, energy-dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy, while the morphology and size analyses were characterized using high-resolution transmission electron microscopy and dynamic light scattering. After optimization of some experimental conditions, particularly pH, a simple and facile system was developed for the naked-eye detection of bisphenol-A. Moreover, a theoretical study of AgCl interaction with bisphenol-A was performed at the density functional level of theory in both gas and solvent phases. Theoretical results showed that electrostatic and van der Waal interactions play important roles in complexation of bisphenol-A with AgCl-NPs, which can lead to aggregation of the as-prepared AgCl-NPs and results in color change from specific yellow to dark purple, where a new aggregation band induced at 542 nm appears. The absorbance at 542 nm was found to be linearly dependent on the bisphenol-A concentration in the range of 1 × 10(-6)-1 × 10(-4) M, with limit of detection of 45 nM. In conclusion, obtained results from the present study can open up an innovative application of the green synthesis of AgCl-NPs using brown algae extract as colorimetric sensors.

  13. Ionic Liquid Surfactant Mediated Structural Transitions and Self-Assembly of Bovine Serum Albumin in Aqueous Media: Effect of Functionalization of Ionic Liquid Surfactants. (United States)

    Singh, Gurbir; Kang, Tejwant Singh


    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.

  14. The occurrence of phi in dento-facial beauty of fine art from antiquity through the Renaissance. (United States)

    Wiener, R Constance; Wiener Pla, Regina M


    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.

  15. 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


    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.

  16. Gay re-readings of the Harlem Renaissance poets. (United States)

    Woods, G


    In the light of the long-established fact of their homosexuality or bisexuality, it is high time for the cluster of "Negro Renaissance" poets, Countee Cullen, Langston Hughes, Claude McKay, and Richard Bruce Nugent, to be reappraised by and for gay readers. This paper seeks to develop gay reading strategies in relation to the poems of these writers, in order to reveal for contemporary readers likely subtexts which, at the time of their writing, were publicly read as bearing on race alone. It is often possible to read a particular poem as referring (in images such as that of the social outcast) to either racial or sexual oppression, interchangeably; and possibly, therefore, to both at once, by way of an implicit comparison. Likewise, poems on miscegenation can just as well be read, via the theme of forbidden love, as referring to homosexuality. The fact that most published critical readings deal only with the racial issue does not invalidate the likelihood that the poem can be, and indeed requires to be, read as referring, also, to sexuality. Gay readings emerge, then, not merely from these writers' representations of attractive men and boys, but also in the midst of their most famously anti-racist themes.

  17. Babinski's sign in medieval, Renaissance, and baroque art. (United States)

    Massey, E W; Sanders, L


    In 1896, Joseph François Babinski first described his well-known sign of dorsiflexion of the big toe on stimulating the sole of the foot. However, unknown to Babinski, several painters had previously demonstrated this phenomenon in their paintings. Sandro Botticelli (1445-1510), a Florentine Renaissance painter, demonstrated this reflex in his Madonna and Child with Angels 400 years before the publication of Babinski's discovery. Botticelli used live infants as models for his paintings. Gentile da Fabriano (d 1427) in his Adoration of the Kings, demonstrates a similar response of toe extension in the infant Jesus when one of the Magi kisses the baby's foot. Similarly, Jacob Schick von Kempter, a 16th century German painter, in his Coronation of the Virgin demonstrates the extensor plantar response in the infant. Correggio (1492-1534), in northern Italy captured the extension and flare of the baby's toes in his Madonna and Child with Mary Magdalen. Raphael (1483-1520) presented the extensor plantar responses in the child when sole pressure is applied in Small Cowper Madonna. Leonardo da Vinci, with his nude model drawings (1503-1507) seemed to have been aware of this response. There is no indication that any of these artists fully understood the physiology behind the response; therefore, the value of this sign in neurologic disease must still rely on Babinski's demonstration several hundred years after its initial demonstration in artistic literature.

  18. Vasari’s progressive (but non-historicist Renaissance

    Directory of Open Access Journals (Sweden)

    Ian Verstegen


    Full Text Available This article examines the meanings of progress and the improvement of the arts in the writings of Giorgio Vasari, arguing that his vision of progress must be understood in a strictly non-historicist way. Using insights of Maurice Mandelbaum and Jörn Rüsen, the characteristics of the (pre-historicist exemplary mode of historical understanding are clarified, according to which history is spatial, which principles are timeless, and how the past is understood in terms of the present. Taking this paradigm for granted, many aspects of Vasari’s writings can be clarified for their historical meaning and his scholarly techniques, which are pioneeringly modern, can be divorced from his historical consciousness, which is pre-modern and non-historicist. Introducing the idea of ‘ordinal’ history as a way to understand progress in the Renaissance without passing over to historicism, both Vasari’s understanding of his contemporaries work, as well as the structure of his Lives, is clarified.

  19. 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)


    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)

  20. Patient-Reported Safety Information: A Renaissance of Pharmacovigilance? (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Eric J. Sharpe


    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.

  2. The Authoritarian Constitution versus the National Renaissance Front

    Directory of Open Access Journals (Sweden)

    Florin GRECU


    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.

  3. A brief historical development of classical mathematics before the Renaissance (United States)

    Debnath, Lokenath


    '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.

  4. Pseudobulbar paralysis in the Renaissance: Cosimo I de' Medici case. (United States)

    Arba, F; Inzitari, D; Lippi, D


    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.

  5. 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. (United States)

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


    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.

  6. Renaissance plays as a useful source for the comparison between English and Croatian early modern medicine. (United States)

    Atalic, Bruno


    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.

  7. The golden beauty: brain response to classical and renaissance sculptures. (United States)

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


    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).

  8. ‘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


    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.

  9. 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. (United States)

    Olguín, María Teresa; Deng, Shuguang


    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.

  10. Nietzsche, Burckhardt et la « question » de la Renaissance


    Gontier, Thierry


    Il n’y a pas eu de question plus cruciale que celle que posait la Renaissance – ma question est celle-là même qu’elle posait (meine Frage ist ihre Frage) (L’Antéchrist, § 61). La « question » de la Renaissance, et plus exactement de la Renaissance italienne, n’est pas premièrement pour Nietzsche la question d’une période de l’histoire de la philosophie caractérisée comme telle (comme c’est par exemple le cas dans la pensée italienne, héritée de Spaventa et de Fiorentino, de la même époque) : ...

  11. The Love Theme of the Renaissance——A Comment on Two Renaissance Poems

    Institute of Scientific and Technical Information of China (English)



    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.

  12. Andreas Vesalius as a renaissance innovative neuroanatomist: his 5th centenary of birth. (United States)

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


    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.

  13. Renaissance: A revolutionary approach for providing low-cost ground data systems (United States)

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


    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.

  14. Applying the World Water and Agriculture Model to Filling Scenarios for the Grand Ethiopian Renaissance Dam

    Energy Technology Data Exchange (ETDEWEB)

    Villa, Daniel L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    The World Water and Agriculture Model has been used to simulate water, hydropower, and food sector effects in Egypt, Sudan, and Ethiopia during the filling of the Grand Ethiopian Renaissance Dam reservoir. This unique capability allows tradeoffs to be made between filling policies for the Grand Ethiopian Renaissance Dam reservoir. This Nile River Basin study is presented to illustrate the capacity to use the World Water and Agriculture Model to simulate regional food security issues while keeping a global perspective. The study uses runoff data from the Intergovernmental Panel for Climate Change Coupled Model Inter-comparison Project Phase 5 and information from the literature in order to establish a reasonable set of hydrological initial conditions. Gross Domestic Product and population growth are modelled exogenously based on a composite projection of United Nations and World Bank data. The effects of the Grand Ethiopian Renaissance Dam under various percentages of water withheld are presented.

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

    Directory of Open Access Journals (Sweden)

    Marleide da Mota Gomes


    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.

  16. Realdo Colombo's "De Re Anatomica": the renaissance origin of the term "placenta" and its historical background. (United States)

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


    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.

  17. Renaissance Science and Literature: Benedetti, Ovid and the Transformations of Phaeton's Myth after Copernicus (United States)

    Omodeo, Pietro Daniel


    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.

  18. The Social Education Program to ]. L. Vives during the Age of the Renaissance

    Directory of Open Access Journals (Sweden)



    Full Text Available My objective in this paper consist to present the Social EducationProgram to J. L. Vives during the Age of the Renaissance. His experiences were gained in the society governing rank, to which by birth he belonged. Now it is to be remembered that the claim to respect which we make for the work of a pionner in any new branch of human to Renaissance: Education in Social Values, to charity, justice, peace, concord, understanding among the peoples. In this important respect, Vives suggest a new and significant subject to solve the social problems to Europe of modern times.

  19. Nickel hydroxide precipitation from aqueous sulfate media (United States)

    Sist, Cinziana; Demopoulos, George P.


    Hydrometallurgical processing of laterite ores constitutes a major industrial and R&D activity in extractive metallurgy. In some of the process flowsheets, nickel hydroxide precipitation is incorporated. For these operations, the optimization of nickel hydroxide precipitation is important to assure efficiency and product quality. The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulfate system using supersaturation controlled precipitation.

  20. The art of human anatomy: Renaissance to 21st century. (United States)

    Van Hee, Robrecht; Wells, F C; Ballestriero, Roberta; Richardson, Ruth; Mazzarello, Paolo; Cani, Valentina; Catani, Marco


    This session examines the relationship between the art and science of anatomy from the time of Vesalius to the present with particular emphasis on the role of the medical artist and the changing nature of anatomical illustration over the last five centuries. Pivotal changes in the art of anatomy will be examined including the evolution of media and brain imaging from Golgi to Geschwind.

  1. Art Appreciation, Farming, Measurement, Reading & Phonics, Renaissance: Daily Life, Sound & Light. (United States)

    Web Feet, 2002


    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)

  2. Chicago's Renaissance 2010: The Small Schools Movement Meets the Ownership Society (United States)

    Ayers, William; Klonsky, Michael


    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.)

  3. WWC Review of the Report "Philadelphia's Renaissance Schools Initiative: 18 Month Interim Report" (United States)

    What Works Clearinghouse, 2012


    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…

  4. Renaissance or a Backward Step? Disparities and Tensions in Two New Swedish Pathways in VET (United States)

    Berglund, Ingrid; Loeb, Ingrid Henning


    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…

  5. The New Saudi Educational Renaissance: In between the "Capacity to Aspire" and the "Capacity to Remember" (United States)

    Pavan, Annalisa


    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…

  6. Origin of the cannula for tracheotomy during the middle ages and Renaissance. (United States)

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


    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.

  7. 76 FR 43349 - General Motors Corporation, Renaissance Center, including On-Site Leased Workers From Accretive... (United States)


    ... 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...

  8. The Effect of School Renaissance on TAAS Scores in the McKinney ISD (United States)

    Nunnery, John A.; Ross, Steven M.; Goldfeder, Elizabeth


    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…

  9. Liberty of Ideas: Renaissance Copia and the Nature of Free Thought. (United States)

    Grudin, Robert


    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)

  10. Renaissance Architecture of Central Scheme: Jerónimo Quijano and his Immediate Environment

    Directory of Open Access Journals (Sweden)

    Antonio Luis López González


    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.

  11. Ideas on Moral and Civil Upbringing of Personality in Italian and Ukrainian Pedagogy During the Renaissance

    Directory of Open Access Journals (Sweden)

    Petruk Natalia


    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.

  12. Multiple identifications and the dialogical self: Maori youngsters and the cultural renaissance

    NARCIS (Netherlands)

    Meijl, A.H.M. van


    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

  13. Organization and Regulation of Fencing in the Realm of France in the Renaissance

    Directory of Open Access Journals (Sweden)

    Dupuis Olivier


    Full Text Available During the nineteenth century, many sources were published about the regulation of fencing in Renaissance France. Comparing those sources shows significant though incomplete uniformity in the formalities observed in the training of students of fencing, particularly in the process followed by the neophyte in his passage to mastery of the art of defence.

  14. Preparing a Union List of Microforms on the Classical, Medieval, and Renaissance Periods. (United States)

    Henneman, John B., Jr.


    Describes a project of the Association of College and Research Libraries to compile a union list of microforms dealing with the classical, medieval, and Renaissance periods. Goals of the project, questionnaire development, survey response, and questions raised by the project are discussed. The union list, including 101 titles and 45 libraries, is…

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

    Directory of Open Access Journals (Sweden)

    Marko Uršič


    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.

  16. Study of Italian Renaissance sculptures using an external beam nuclear microprobe (United States)

    Zucchiatti, A.; Bouquillon, A.; Moignard, B.; Salomon, J.; Gaborit, J. R.


    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.

  17. 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. (United States)

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


    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.

  18. The art in Abel Salazar's life (1889-1946)--a Portuguese Renaissance spirit of the twentieth century. (United States)

    Nabais, João-Maria


    Abel Salazar was a true renaissance spirit, scientist, doctor, humanist, artist and writer. His paintings combined realism with a very strong social sense. This article looks at his art and the influence that he had through it on his contemporaries.

  19. La Renaissance de Carl Schmitt = The Renaissance of Carl Schmitt : about Ellen Kennedy book: «Constitutional failure : Carl Schmitt in Weimar»



    En Carl Schmitt en la República de Weimar. La quiebra de una Constitución la profesora Ellen Kennedy ha elaborado una grandiosa y sugerente contextualización del pensamiento y la obra de Schmitt. A la luz de nuevos materiales ha desvelado algunas de las más importantes claves del pensamiento del autor alemán, y ha puesto al descubierto las razones que explican la Schmitt’s Renaissance en el universo cultural anglosajón. La autora sitúa los textos constitucionales en el contexto de la Repúblic...

  20. 'Epidemic' of hand deformities in the French Renaissance paintings of Jean and François Clouet. (United States)

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


    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.

  1. 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


    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.

  2. Renaissance bookbindings on Slovene reformation prints from the Slovene National Museum in Ljubljana

    Directory of Open Access Journals (Sweden)

    Sonja Svoljšak


    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.

  3. 传统工艺“返老还童”%The Renaissance of Handicrafts

    Institute of Scientific and Technical Information of China (English)



    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”’。

  4. A classification of perceptual corrections of perspective distortions in renaissance painting. (United States)

    Verstegen, Ian


    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.

  5. Application of PIXE to the study of Renaissance style enamelled gold jewelry (United States)

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


    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.

  6. Report from the field: Overview of the Sixth Annual Vaccine Renaissance Conference. (United States)

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


    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.

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

    DEFF Research Database (Denmark)

    Catana, Leo


    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...... ethics, by then perceived as a legitimate form of Platonic ethics. Plotinus’ ethics had been transmitted through the Middle Ages through Macrobius’ Latin treatise In somnium Scipionis I.8, which relied heavily on Plotinus’ student, Porphyry, and his report of Plotinus’ ethics. In this article...... it is argued that the Florentine humanist and philosopher Marsilio Ficino carried on this tradition of Platonic, or rather Plotinian, ethics. He was familiar with Plotinus’ Enneads, since he had had access to it through Greek manuscripts from around 1462; his Latin translation of the Enneads was published...

  8. 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


    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.

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


    Spero, Denice; Levitz, Lauren


    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 tula...

  10. Some Renaissance, Baroque, and contemporary cultural elaborations of the art of memory. (United States)

    Bimler, David L


    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.

  11. Media education. (United States)

    Strasburger, Victor C


    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.

  12. Francis Bacon and the "Interpretation of Nature" in the late Renaissance. (United States)

    Serjeantson, Richard


    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.

  13. Media violence. (United States)

    Strasburger, V C


    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.


    NARCIS (Netherlands)



    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

  15. The Renaissance. Grade 7 Model Lesson for Standard 7.8. World History and Geography: Medieval and Early Modern Times. California History-Social Science Course Models. (United States)

    Zachlod, Michelle, Ed.

    California State Standard 7.8 is delineated in the following manner: "Students analyze the origins, accomplishments, and diffusion of the Renaissance," in terms of the way in which the revival of classical learning and the arts affected a new interest in humanism; the importance of Florence in the early stages of the Renaissance and the…

  16. Heather Clark. The Ulster Renaissance - Poetry in Belfast 1962-1972

    Directory of Open Access Journals (Sweden)

    Maryvonne BOISSEAU


    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 ...

  17. Difference in General Writing Characteristics between Famous Dramatists during English Renaissance

    Institute of Scientific and Technical Information of China (English)



    <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

  18. The renaissance begins with you ... the search is on for best practices. (United States)

    Kingston, M E


    A new spirit of innovation is arising in health care. Just as the historical renaissance opened new frontiers of European art, architecture, science, and literature, we have the opportunity to release a new wave of innovation that will revolutionize healthcare delivery. The means are near at hand. Never before has our knowledge been so deep, technology so powerful, or communications so fast and wide. Yet, like medieval scholars, isolated in our monasteries, we have so far had limited effect in positively changing the system. Real change begins today--as soon as we begin talking to one another, comparing our experiences, sharing our problems, devising solutions, and imagining the future together.

  19. The Renaissance of Nuclear Energy in the Shadow of Climate Change (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

  20. Corps, apparences vestimentaires et identités en France à la Renaissance

    Directory of Open Access Journals (Sweden)

    Isabelle Paresys


    Full Text Available Un corps vêtu spécifique émerge à la Renaissance en France et particulièrement à la Cour. Le vêtement impose sa marque sur le corps, accentue le dimorphisme sexuel des apparences, et donne à celles-ci rectitude ou distorsion, transformant le corps en une surface décorative sur laquelle peut s’exprimer la magnificence des souverains et celle de leur cour. Ce corps vêtu résulte de l’influence de modes européennes et de nouvelles normes de civilité qui construisent la présentation de soi. Elles trouvent leur pleine expression à la cour où le corps de mode aristocratique affiche une éloquence distinctive et cosmopolite. Dans le même temps, les identités qu’inculque le vêtement au corps paraissent menacées par les transferts de pratiques vestimentaires entre les sexes, entre les groupes sociaux et entre les nations, entraînant un malaise envers ce brouillage des apparences qui prend une couleur particulière durant les guerres civiles quand se pose de manière sanglante la question des identités et de la conscience nationale.Body, Dress and Identities in Renaissance France. A specific type of clothed body emerged in 16th century France especially at Court. Clothing put its mark on the body, accentuating sexual dimorphism, imposing either Renaissance rectitude or distortions, transforming the body into a decorative surface for displaying magnificence. Its specificity resulted from the influence of various vestimentary and decorative fashions, starting with the new kinds of civility circulating in Renaissance Europe, which fashioned self-presentation. It found its fullest expression on the bodies of cosmopolitan aristocrats seeking a distinctive eloquence for their particular identity. At the same time, the identities which clothes imprinted on their wearer seemed threatened by transfers of vestimentary practices between sexes, sexual groups, and/or nations. The unease created by this mixture of appearances reflects that of

  1. Surgically repaired cleft lips depicted in paintings of the late Gothic period and the Renaissance. (United States)

    Pirsig, W; Haase, S; Palm, F


    Paintings and drawings by Lucas Moser, Leonardo da Vinci, Albrecht Dürer, and Jacob Cornelisz van Oostsanen suggest that they employed people who had had cleft lips operated on as models for their works of art. Created between 1431 and 1520, the portraits show diagnostic facial profiles with a curved nasal dorsum, short columella, maxillary retrusion, and pseudoprogenia. The first medical illustration of cleft lip surgery was published in 1564 by Ambroise Paré. It was therefore late Gothic and Renaissance artists who depicted the conspicuous signs of surgically treated patients with cleft lip more than 130 years before the surgeons.

  2. Introduction to “Marriage and Elite Structure in Renaissance Florence, 1282-1500”



    El siguiente texto, salido de una ponencia de conferencia y escrito en 1994 es el primer borrador de un artículo publicado en el 2010 en Renaissance Quarterly y llamado “Open Elite? Social Mobility, Marriage, and Family in Florence, 1282-1494.” Esta introducción debate las justificaciones metodológicas para publicar un primer borrador, escrito seis años antes del artículo final más sofisticado. Al descubrir algunos de los pasos del proceso de investigación permite examinar la relación entre l...

  3. The outlook for nuclear energy in the United States dark ages, renaissance, or age of enlightenment?

    Energy Technology Data Exchange (ETDEWEB)

    Brodman, J.


    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

  4. Media Flow

    DEFF Research Database (Denmark)

    Kabel, Lars


    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....

  5. Generalized corrosion of nickel base alloys in high temperature aqueous media: a contribution to the comprehension of the mechanisms; Corrosion generalisee des alliages a base nickel en milieu aqueux a haute temperature: apport a la comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti-Sillans, L


    In France, nickel base alloys, such as alloy 600 and alloy 690, are the materials constituting steam generators (SG) tubes of pressurized water reactors (PWR). The generalized corrosion resulting from the interaction between these alloys and the PWR primary media leads, on the one hand, to the formation of a thin protective oxide scale ({approx} 10 nm), and on the other hand, to the release of cations in the primary circuit, which entails an increase of the global radioactivity of this circuit. The goal of this work is to supply some new comprehension elements about nickel base alloys corrosion phenomena in PWR primary media, taking up with underlining the effects of metallurgical and physico-chemical parameters on the nature and the growth mechanisms of the protective oxide scale. In this context, the passive film formed during the exposition of alloys 600, 690 and Ni-30Cr, in conditions simulating the PWR primary media, has been analyzed by a set of characterization techniques (SEM, TEM, PEC and MPEC, XPS). The coupling of these methods leads to a fine description, in terms of nature and structure, of the multilayered oxide forming during the exposition of nickel base alloys in primary media. Thus, the protective part of the oxide scale is composed of a continuous layer of iron and nickel mixed chromite, and Cr{sub 2}O{sub 3} nodules dispersed at the alloy / mixed chromite interface. The study of protective scale growth mechanisms by tracers and markers experiments reveals that the formation of the mixed chromite is the consequence of an anionic mechanism, resulting from short circuits like grain boundaries diffusion. Besides, the impact of alloy surface defects has also been studied, underlining a double effect of this parameter, which influences the short circuits diffusion density in oxide and the formation rate of Cr{sub 2}O{sub 3} nodules. The sum of these results leads to suggest a description of the nickel base alloys corrosion mechanisms in PWR primary

  6. Mass Media

    Institute of Scientific and Technical Information of China (English)



    @@ 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.

  7. The ReNAissanCe of mRNA-based cancer therapy. (United States)

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


    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.

  8. [Brief history of lead poisoning: from Egyptian civilization to the Renaissance]. (United States)

    Robles-Osorio, María Ludivina; Sabath, Ernesto


    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.

  9. Renaissance arabe et solidarité musulmane dans La Nation arabe

    Directory of Open Access Journals (Sweden)

    Anne-Claire de Gayffier-Bonneville


    Full Text Available Publiée à Genève de 1930 à 1938, la revue La Nation arabe voulait initialement s'adresser aux intellectuels européens. Les points de vue développés par les deux rédacteurs, Chekib Arslan et Ihsan al-Djabri, montrent toutefois que le lectorat visé était surtout arabe et musulman. Arslan et Djabri sont convaincus de la renaissance de la nation arabe, qu'ils attribuent en grande partie à la politique des puissances européennes dans les États arabes. Les signes de ce réveil sont rapportés, notamment l'intérêt mutuel que les Arabes se portent, la communion des peuples dans la souffrance, l'émergence de personnalités hors du commun. La revue avait une intention militante originale pour l'époque : elle entendait mobiliser les esprits en vue de mener le combat de la renaissance, arabe et musulmane, non seulement contre les puissances occupantes, mais aussi contre le projet sioniste qui menaçait l'intégrité territoriale de la Palestine, voire de la patrie arabe.

  10. Breast cancer surgery: an historical narrative. Part I. From prehistoric times to Renaissance. (United States)

    Sakorafas, George H; Safioleas, Michael


    Cancer was known as a disease since prehistoric times. Management of breast cancer evolved slowly through centuries in the ancient world up to the Renaissance. This period is marked by the absence of any scientifically verifiable understanding of the true nature of cancer and its natural history and consequently by a lack of effective treatment. Breast has been considered as a symbol of femininity, fertility and beauty. Hippocrates proposed that breast cancer, among other neoplasms, was a 'systemic disease' caused by an excess of black bile. The humoral theory was further supported by Galen and dominated for centuries in medicine. Fulguration and breast amputation by using various instruments to achieve a rapid operation were widely used up to the 18th century. The Renaissance was a revolutionary period, since it stimulated medical practice; at that time physicians started to scientifically study medicine. Vesalius greatly contributed in the advancement of surgery, and he vigorously opposed Galen's doctrines. Many great surgeons of that time (including Paré, Cabrol, Servetto, Scultetus, Tulp, Fabry von Hilded, etc.) advanced the science of surgery. Interestingly, Bartoleny Gabrol (1590) in Montpellier advocated radical mastectomy, which was popularised by Halsted, 300 years later. However, the lack of anaesthesia and the problem of wound infections (due to the lack of the aseptic techniques) generated significance and often problems for the surgeons of that time. Surgery was often 'heroic' but primitive and even inhumane by current standards. Therapeutic nihilism was the prevailing altitude regarding breast cancer, at least among the vast majority of surgeons.

  11. Cultural relations between Hungary and Albania during the period of Humanism and Renaissance

    Directory of Open Access Journals (Sweden)

    Muhamet Mala


    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.

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

    Directory of Open Access Journals (Sweden)

    Ibrahim Abushihab


    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

  13. Mixed Media (United States)

    Peterson, Erin


    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  14. Media places

    DEFF Research Database (Denmark)

    Linde, Per; Messeter, Jörn

    for the Media places project, give some brief insights into the themes of setting up temporary digital streams of media and mobile games. Considering the work-in-progress character of the research and the smaller format of text, no real in-depth analysis will be carried out. The goal is rather to position...

  15. Media darling

    CERN Multimedia

    Chalmers, Matthew


    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)

  16. Renaissance Science and Literature: Benedetti, Ovid and the Transformations of Phaeton's Myth after Copernicus (United States)

    Omodeo, Pietro Daniel


    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…

  17. On the origin of patterning in movable Latin type : Renaissance standardisation, systematisation, and unitisation of textura and roman type

    NARCIS (Netherlands)

    Blokland, F.E.


    This PhD-research is conducted to test the hypothesis that Gutenberg and consorts developed a standardised and even unitised system for the production of textura type, and that this system was extrapolated for the production of roman type in Renaissance Italy. For roman type, Humanistic handwriting

  18. 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


    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.

  19. Agricultural Renaissance

    Institute of Scientific and Technical Information of China (English)


    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

  20. "Renaissance Man" (United States)

    Smith, Susan


    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…

  1. Tang Renaissance

    Institute of Scientific and Technical Information of China (English)


    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,

  2. The environmental education in the Italian Renaissance: the geoethical model of Machiavelli (United States)

    Liserre, Battista; De Pascale, Francesco


    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

  3. Media violence. (United States)

    Cantor, J


    Research on the effects of media violence is not well understood by the general public. Despite this fact, there is an overwhelming consensus in the scientific literature about the unhealthy effects of media violence. Meta-analyses show that media-violence viewing consistently is associated with higher levels of antisocial behavior, ranging from the trivial (imitative violence directed against toys) to the serious (criminal violence), with many consequential outcomes in between (acceptance of violence as a solution to problems, increased feelings of hostility, and the apparent delivery of painful stimulation to another person). Desensitization is another well-documented effect of viewing violence, which is observable in reduced arousal and emotional disturbance while witnessing violence, the reduced tendency to intervene in a fight, and less sympathy for the victims of violence. Although there is evidence that youth who are already violent are more likely to seek out violent entertainment, there is strong evidence that the relationship between violence viewing and antisocial behavior is bidirectional. There is growing evidence that media violence also engenders intense fear in children which often lasts days, months, and even years. The media's potential role in solutions to these problems is only beginning to be explored, in investigations examining the uses and effects of movie ratings, television ratings, and the V-chip, and the effects of media literacy programs and public education efforts. Future research should explore important individual differences in responses to media violence and effective ways to intervene in the negative effects.

  4. Structure, dynamics, and hydration of a collagen model polypeptide, (L-prolyl-L-prolylglycyl)10, in aqueous media: a chemical equilibrium analysis of triple helix-to-single coil transition. (United States)

    Shikata, Toshiyuki; Minakawa, Ayako; Okuyama, Kenji


    The structure, dynamics, and hydration behavior of a collagen model polypeptide, (L-prolyl-L-prolylglycyl)(10) (PPG10), were investigated in pure water and dilute acetic acid over a wide temperature range using broadband dielectric relaxation (DR) techniques that spanned frequencies from 1 kHz to 20 GHz. All samples showed pronounced dielectric dispersion with two major relaxation processes around 3 MHz and 20 GHz. Because DR measurements sensitively probe dipoles and their dynamics, the structures and ionization states of the carboxy and amino termini of aqueous PPG10 were precisely determined from the relaxation times and strengths in the 3 MHz frequency range. In solution, PPG10 formed mixtures of monodisperse rods as triple helices with lengths and diameters of 8.6 and 1.5 nm, respectively, and monomeric random coils with radii of approximately 1.4 nm. Ionization of the C-terminus was suppressed by the addition of acetic acid in both states. The fraction of random coils (f(coil)) was found to be a function of temperature (T) and the concentration of PPG10 (c). At low temperatures, small f(coil) values were found, which increased with temperature to reach f(coil) = 1 at approximately 60 degrees C, irrespective of c. This phenomenon, well-known as a triple helix-to-single coil transition, is discussed on the basis of the chemical reaction, (PPG10)(3) 3PPG10, with an equilibrium constant of K = 3(c/55.6)(2)f(coil)(3)(1 - f(coil))(-1). The standard enthalpy change evaluated from Arrhenius plots (ln K versus T(-1)) was found to change dramatically at the same transition temperature that was previously determined by using optical rotation experiments. The other major DR process, observed at approximately 20 GHz, was assigned to free and hydrated water molecules and used to determine the average hydration number (m) per PPG10. The m values for the triple helix and random coil state at 25 degrees C were evaluated to be m(th) = 60-70 and m(coil) = 250-270. The m

  5. Shakespeare and other English Renaissance authors as characterized by Information Theory complexity quantifiers (United States)

    Rosso, Osvaldo A.; Craig, Hugh; Moscato, Pablo


    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.

  6. Raman spectroscopic study of “The Malatesta”: A Renaissance painting? (United States)

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


    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.

  7. Ulisse Aldrovandi's Pandechion epistemonicon and the use of paper technology in Renaissance natural history. (United States)

    Kraemer, Fabian


    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.

  8. "Being the world eternal ..." the age of the Earth in Renaissance Italy. (United States)

    Dal Prete, Ivano


    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.

  9. From the Flamm-Einstein-Rosen bridge to the modern renaissance of traversable wormholes (United States)

    Lobo, Francisco S. N.


    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’.

  10. Heavenly Networks. Celestial Maps and Globes in Circulation between Artisans, Mathematicians, and Noblemen in Renaissance Europe. (United States)

    Gessner, Samuel


    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.

  11. Dominique Brancher, Équivoques de la pudeur. Fabrique d’une passion à la Renaissance


    Chapuis-Després, Stéphanie


    Également auteure de Quand l’esprit vient aux plantes. Botanique sensible et subversion libertine (XVIe-XVIIIe s.), publié en 2015, Dominique Brancher, professeure de littérature à l’université de Bâle, étudie les rapprochements entre littérature et savoir à la Renaissance et met au jour la difficulté à classer les plantes dans une catégorie spécifique du vivant à l’époque moderne. Les Équivoques de la pudeur est le résultat de son travail d’habilitation. Écrit dans une langue érudite qui rév...

  12. The Trattato as Textbook: Francesco di Giorgio’s Vision for the Renaissance Architect

    Directory of Open Access Journals (Sweden)

    Elizabeth Mays Merrill


    Full Text Available In fifteenth-century Italy, the architect’s role lacked definition. The classical conception of the architect — the distinguished professional lauded by Vitruvius and Cicero, as theoretically versed as he was technically skilled — had faded in the medieval period. Even the term ‘'architectus'’, with its powerful connotations of creation and authorship, had fallen out of use (Kostof 1977: 60–61. Furthermore, there was no standard of training or apprenticeship for the architect. Depending on the context, the engineer, carpenter, patron, or building administrator might be considered the building’s architect (Hollingsworth 1984: 385–410. On the role of the architect in the Italian Renaissance and the development of an architectural profession, see Ackerman 1991, Ettlinger 1977, and Wilkinson 1977. But beginning around 1400, numerous artists, scholars, and patrons began to express the need for an established architectural profession.

  13. From the Flamm-Einstein-Rosen bridge to the modern renaissance of traversable wormholes

    CERN Document Server

    Lobo, Francisco S N


    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'.

  14. From Augmentation Media to Meme Media. (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…

  15. Community Media: Muting the Democratic Media Discourse?

    NARCIS (Netherlands)

    Carpentier, N.; Lie, R.; Servaes, J.


    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

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

    Directory of Open Access Journals (Sweden)

    Ann Haughton


    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.


    DEFF Research Database (Denmark)

    Fausing, Bent


    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...

  18. Social Media



    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...

  19. Media Bias


    Sendhil Mullainathan; Andrei Shleifer


    There are two different types of media bias. One bias, which we refer to as ideology, reflects a news outlet's desire to affect reader opinions in a particular direction. The second bias, which we refer to as spin, reflects the outlet's attempt to simply create a memorable story. We examine competition among media outlets in the presence of these biases. Whereas competition can eliminate the effect of ideological bias, it actually exaggerates the incentive to spin stories.

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

    Mengel, Thomas


    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. MIPs in Aqueous Environments. (United States)

    Wan, Ying-chun; Ma, Hui-ting; Lu, Bin


    When organic solvent-compatible molecularly imprinted polymers (MIPs) are used in aqueous environment, how to reduce nonspecific binding is a major challenge. By modifying the binding solvents and introducing appropriate washing and elution steps, even relatively hydrophobic MIPs can gain optimal rebinding selectivity in aqueous conditions. Furthermore, water-compatible MIPs that can be used to treat aqueous samples directly have been prepared. The use of hydrophilic co-monomers, the controlled surface modification through controlled radical polymerization, and the new interfacial molecular imprinting methods are different strategies to prepare water-compatible MIPs. By combining MIPs with other techniques, both organic solvent-compatible and water-compatible MIPs can display better functional performances in aqueous conditions. Intensive studies on MIPs in aqueous conditions can provide new MIPs with much-improved compatibilities that will lead to more interesting applications in biomedicine and biotechnology.

  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


    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.


    NARCIS (Netherlands)

    Wijnen, J.W; Steiner, R.A.; Engberts, J.B.F.N.


    Second-order rate constants for the cycloaddition of phenyl azide to norbornene were determined in aqueous solutions. In organic solvents this reaction shows a very small solvent effect. In highly aqueous media, however, remarkable accelerations are observed. The solvent dependence of the rate const

  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


    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


    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:

  6. Raman microscopy and x-ray fluorescence analysis of pigments on medieval and Renaissance Italian manuscript cuttings


    Burgio, Lucia; Clark, Robin J.H.; Hark, Richard R.


    Italian medieval and Renaissance manuscript cuttings and miniatures from the Victoria and Albert Museum were analyzed by Raman microscopy to compile a database of pigments used in different periods and different Italian regions. The palette identified in most manuscripts and cuttings was found to include lead white, gypsum, azurite, lazurite, indigo, malachite, vermilion, red lead, lead tin yellow (I), goethite, carbon, and iron gall ink. A few of the miniatures, such as the historiated capit...

  7. Assessment of hydrological changes in the Nile River due to the construction of Renaissance Dam in Ethiopia

    Directory of Open Access Journals (Sweden)

    Mohammed El Bastawesy


    Full Text Available This paper assesses impact of the Renaissance Dam on Ethiopia; on the Nile discharge ultimately reaches Egypt downstream. The Landsat-8 satellite images of 2013 were obtained and interpreted to identify locations for the construction sites for the Renaissance Dam. Then the Shuttle Radar Topography Mission (SRTM data were obtained and processed to create a digital elevation model (DEM for the Blue Nile upstream areas that will be submerged. Different scenarios for the dams’ heights and resulting storages were simulated to estimate the resulting abstraction of the Blue Nile flows until completion of the project and the annual losses due to evaporation thereafter. The current site (506 m asl for the Renaissance Dam allows the creation of a 100 m deep reservoir with a total storage of 17.5 km3; overflows will occur at that lake’s level (606 m asl from the north western part of the developed lake into Rosaires downstream. Construction of the spillway dam to control the overflow area can allow the creation of a 180 m deep lake that store up to 173 km3 in a lake that will cover 3130 km2. The analysis of Tropical Rainfall Monitoring Mission (TRMM suggests that the variation of total annual rainfall could reach 20%, thus the resulting hydrological fluctuations could affect the estimated filling time, the operational functions and discharge downstream. The negative hydrological impacts of the Renaissance Dam will increase by increasing the height of its spillway dam, as increasing the storage capacity could affect the strategic storage for the reservoirs in Egypt and Sudan. It is strongly recommended that an agreement should be reached to compromise the storage capacities and water supplies for all dams on the Nile to thoroughly satisfy the necessary needs.

  8. Social Media (United States)


    Digital Marketing and Ecommerce Professionals. 29 January 2010. 20 May 2010. < media...Statistics Revisited.” Econsultancy | Community of Digital Marketing and Ecommerce Professionals. 29 Jan. 2010. 20 May 2010. <

  9. Streaming Media (United States)

    Pulley, John


    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…

  10. An approach to Renaissance margins: some representations of the labyrinth on the Elizabethan stage

    Directory of Open Access Journals (Sweden)

    Sophie ALATORRE


    Full Text Available Alors que la notion de centre, très liée à celle du pouvoir, a longtemps été au cœur des enjeux culturels, sociaux et littéraire, l’importance des marges, lieu métamorphique de transition et de différence, est désormais réhabilitée. Durant la Renaissance, l’espace marginal s’assimile fréquemment à celui du labyrinthe, figure mythique tant attractive que répulsive, ré-inventée et remaniée à l’envi comme tant d’autres mythes au cours du seizième siècle. Les textes de trois grands dramaturges que furent Marlowe, Peele et Shakespeare en témoignent : lorsqu’ils abordent des thèmes tels que la réclusion, l’intimité, la déviance ou les stratégies de l’oblique, l’image du labyrinthe est convoquée et permet de décrire une réalité marginale où la parole se délie et le regard critique se développe, et qui, insensiblement, se mue peu à peu vers le centre. On peut dès lors se demander si les méandres où évoluent les personnages ne constituent pas, dans une moindre mesure, une véritable passerelle vers le pouvoir : errer dans l’espace liminal des marges, à la Renaissance, revient aussi à conquérir une individualité et une liberté qu’il faut parfois payer au prix fort. C’est cette thématique féconde et complexe à la fois  que nous nous proposons d’aborder dans cet article, en prenant appui sur les textes de l’époque, afin de mieux comprendre les sensibilités et les représentations des contemporains de Shakespeare.

  11. [The neuroanatomy of Juan Valverde de Amusco and medicine at the time of the Spanish renaissance]. (United States)

    Martín Araguz, A; Bustamante Martínez, C; Toledo León, D; López Gómez, M; Moreno Martínez, J M

    Juan Valverde de Amusco (c. 1525-c. 1564) is considered to have been the most important Spanish anatomist of the XVI century. A follower of Vesalius, he increased and divulged knowledge of anatomy during the Renaissance and his book The history of the composition of the human body was printed in Rome in 1556. The objective of this paper is to study the neuroanatomy in this book and present unpublished biographical data and describe the main contributions of this Castilian doctor to the neurosciences, in the context of Spanish medicine during the Renaissance period. He was born in the town of Hamusco (today Amusco) in the province of Palencia, which belonged to the Crown of Castile. Juan Valverde emigrated to Italy to improve his scientific knowledge. He carried out anatomical studies using the then revolutionary method of direct observation, as opposed to the Galenic criteria of authority inherited from the Medieval period. He trained in Padua under Realdo Colombo and lived in Rome where he practiced medicine until his death, becoming deservedly famous. He did not return to Spain since in the Spanish universities of the time there was a mentality which was reactionary to modern anatomy. His works, published in Italy but in the Spanish language, give an idea of the power of the Crown of Castile in the Europe of that period. The book is profusely illustrated with the first illustrations ever published in the history of printing, drawn by Nicolas Beatrizet. The book was sold widely and was translated and reedited on many occasions, until well into the XVIII century. For the first time Valverde made precise references to the minor circulation. He was the first anatomist to describe the muscles for movement of the eye correctly and the intracranial course of the carotid arteries. In his work he made the first drawing of the stapes, described by the Valencian Luis Collado. Vesalius and Valverde contributed decisively to the beginnings of modern neuroanatomy. Thanks to

  12. [Chronic otitis mediaChronic Otitis Media]. (United States)

    Kohles, N; Schulz, T; Eßer, D


    There are 2 different kinds of chronic otitis media: Otitis media chronica mesotympanalis and otitis media chronica epitympanalis (cholesteatoma). The incidence of chronic otitis media as reported in literature differs in a wide range. The incidence rates vary between 0.45 and 46%. Both, otitis media chronica mesotympanalis and cholesteatoma, lead to eardrum perforation due to lengthy and recurring inflammations. Furthermore, chronic otitis media is characterized by frequently recurring otorrhea and conductive hearing loss.

  13. Otitis media with effusion (United States)

    OME; Secretory otitis media; Serous otitis media; Silent otitis media; Silent ear infection; Glue ear ... fluid drains from the tube and is swallowed. Otitis media with effusion (OME) and ear infections are ...

  14. The Coming Nuclear Renaissance for Next Generation Safeguards Specialists--Maximizing Potential and Minimizing the Risks

    Energy Technology Data Exchange (ETDEWEB)

    Eipeldauer, Mary D [ORNL


    This document is intended to provide an overview of the workshop entitled 'The Coming Nuclear Renaissance for the Next Generation Safeguards Experts-Maximizing Benefits While Minimizing Proliferation Risks', conducted at Oak Ridge National Laboratory (ORNL) in partnership with the Y-12 National Security Complex (Y-12) and the Savannah River National Laboratory (SRNL). This document presents workshop objectives; lists the numerous participant universities and individuals, the nuclear nonproliferation lecture topics covered, and the facilities tours taken as part of the workshop; and discusses the university partnership sessions and proposed areas for collaboration between the universities and ORNL for 2009. Appendix A contains the agenda for the workshop; Appendix B lists the workshop attendees and presenters with contact information; Appendix C contains graphics of the evaluation form results and survey areas; and Appendix D summarizes the responses to the workshop evaluation form. The workshop was an opportunity for ORNL, Y-12, and SRNL staff with more than 30 years combined experience in nuclear nonproliferation to provide a comprehensive overview of their expertise for the university professors and their students. The overall goal of the workshop was to emphasize nonproliferation aspects of the nuclear fuel cycle and to identify specific areas where the universities and experts from operations and national laboratories could collaborate.

  15. The renaissance of bacillosamine and its derivatives: pathway characterization and implications in pathogenicity. (United States)

    Morrison, Michael J; Imperiali, Barbara


    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.

  16. A RAS renaissance: emerging targeted therapies for KRAS-mutated non-small cell lung cancer. (United States)

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


    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.

  17. Probing the Ultraviolet Luminosity Function of the Earliest Galaxies with the Renaissance Simulations (United States)

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


    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.

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


    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.

  19. New β-lactamase inhibitors: a therapeutic renaissance in an MDR world. (United States)

    Drawz, Sarah M; Papp-Wallace, Krisztina M; Bonomo, Robert A


    As the incidence of Gram-negative bacterial infections for which few effective treatments remain increases, so does the contribution of drug-hydrolyzing β-lactamase enzymes to this serious clinical problem. This review highlights recent advances in β-lactamase inhibitors and focuses on agents with novel mechanisms of action against a wide range of enzymes. To this end, we review the β-lactamase inhibitors currently in clinical trials, select agents still in preclinical development, and older therapeutic approaches that are being revisited. Particular emphasis is placed on the activity of compounds at the forefront of the developmental pipeline, including the diazabicyclooctane inhibitors (avibactam and MK-7655) and the boronate RPX7009. With its novel reversible mechanism, avibactam stands to be the first new β-lactamase inhibitor brought into clinical use in the past 2 decades. Our discussion includes the importance of selecting the appropriate partner β-lactam and dosing regimens for these promising agents. This "renaissance" of β-lactamase inhibitors offers new hope in a world plagued by multidrug-resistant (MDR) Gram-negative bacteria.

  20. Joining the Nuclear Renaissance with the Engineering Business Unit of AREVA

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, Nathalie; Menguy, Stephane [SGN, AREVA Group, 1 rue des Herons, 78182 Saint-Quentin en Yvelines Cedex (France); Valery, Jean-Francois [AREVA NC, AREVA Group, Tour AREVA, 1 place de la Coupole, 92084 Paris La Defense Cedex (France)


    The reality of the nuclear renaissance is no longer a question. All over the world, new nuclear plants are going to be deployed; the whole fuel cycle has to be adjusted to fulfil their needs, the front-end to produce the fuel and the back-end to properly manage radioactive waste. AREVA fuel cycle engineering teams have been involved in the design of a variety of industrial plants covering the entire fuel cycle for 50 years. The consistency of the French nuclear policy has been a major factor to acquire and renew the competencies and workforce of AREVA Engineering Business Unit. Our partnership with our customers, French ones but also Japanese, Americans and from other countries, has led us to develop a comprehensive approach of the services that we can deliver, in order to give them the best answer. SGN teams have been involved in the R and D phases in order to take into account the industrialisation aspects as early as possible, and our work does not end with the delivery of the plants; it includes assistance to the operators to optimise and keep their facilities in line with the changing rules and constraints, which ensures the integration of a wide operational experience feedback and the ability to design flexible facilities. This paper will present through our experience how this global approach has been developed and continuously improved and how we are preparing our teams to be ready to answer to the coming needs. (authors)

  1. Our unacknowledged ancestors: dream theorists of antiquity, the middle ages, and the renaissance. (United States)

    Rupprecht, C S


    Exploring the dream world from a modern, or post-modern, perspective, especially through the lens of contemporary technologies, often leads us as researchers to see ourselves as engaged in a new and revolutionary discourse. In fact, this self-image is a profoundly ahistorical one, because it ignores the contributions of ancient, medieval and Renaissance oneirologists who wrote extensively, albeit in different terms and images of lucidity, prerecognition, day residue, wish fulfillment, incubation, problem solving, REM, obe, and the collective unconscious. There are also analogues in these early accounts to anxiety, recurrent, mirror, telepathic, shared, flying, and death dreams. Dream interpretation through music, analysis of dream as narrative, sophisticated theories about memory and language and symbolization are all part of the tradition. Further, early texts pose many issues in sleep and dream research which are not currently being pursued. We dream workers of the late twentieth century should therefore fortify ourselves with knowledge of the oneiric past as one important way to enhance our dream work in the twenty-first century.

  2. Medieval and Renaissance anatomists: the printing and unauthorized copying of illustrations, and the dissemination of ideas. (United States)

    Lanska, Douglas J; Lanska, John Robert


    The vanguard that began to question Galenic anatomical dogma originated in northern Italy in the latter half of the thirteenth century, and not coincidentally this was where human dissection was introduced, which in turn eventually fostered the origins of realistic anatomical illustration in the late fifteenth century. With the advent of the printing press and moveable type at this time, printed books began to supersede hand-copied medieval manuscripts, and labor-intensive techniques were soon developed to integrate text and illustrations on the printed page. The same technology was used to pirate the illustrations of prior authors with varying fidelity. Specific medieval and Renaissance anatomical illustrations can often be traced from their inceptions through different stages of development to the final printed images, and then through subsequent pirated versions in various abridgements or other compendia. The most important milestone in the development of anatomy and anatomical illustration was the publication in 1543 by Andreas Vesalii of De humani corporis fabrica (On the Fabric of the Human Body), commonly referred to simply as the Fabrica. With this work, Vesalii succeeded in coordinating a publication production team (author, artists, block cutters, publisher, and typesetters) to achieve an unprecedented integration of scientific discourse, medical illustration, and typography. However, despite Vesalii's valiant efforts to prevent unauthorized duplication, the illustrations from the Fabrica were extensively plagiarized. Although Vesalii found such piracy frustrating and annoying, the long-term effect was to make Vesalii's ideas known to a wider readership and to help solidify his own revolutionary contributions to anatomy.

  3. An Assessment of Reservoir Filling Policies under a Changing Climate for Ethiopia's Grand Renaissance Dam (United States)

    King, A.; Block, P. J.


    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.

  4. 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


    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 ...

  5. Late Pop III Star Formation During the Epoch of Reionization: Results from the Renaissance Simulations (United States)

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


    We present results on the formation of Population III (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 Mpc3, 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 ˜3 × 107 M ⊙. We quantify the properties of these Pop III galaxies and their Pop III star formation environments. We look for analogs to the recently discovered luminous Ly α emitter CR7, which has been interpreted as a Pop III star cluster within or near a metal-enriched star-forming galaxy. We find and discuss a system similar to this in some respects, however, the Pop III star cluster is far less massive and luminous than CR7 is inferred to be.

  6. Continuum mechanics through the ages from the renaissance to the twentieth century : from hydraulics to plasticity

    CERN Document Server

    Maugin, Gérard A


    Mixing scientific, historic and socio-economic vision, this unique book complements two previously published volumes on the history of continuum mechanics from this distinguished author. In this volume, Gérard A. Maugin looks at the period from the renaissance to the twentieth century and he includes an appraisal of the ever enduring competition between molecular and continuum modelling views. Chapters trace early works in hydraulics and fluid mechanics not covered in the other volumes and the author investigates experimental approaches, essentially before the introduction of a true concept of stress tensor. The treatment of such topics as the viscoelasticity of solids and plasticity, fracture theory, and the role of geometry as a cornerstone of the field, are all explored. Readers will find a kind of socio-historical appraisal of the seminal contributions by our direct masters in the second half of the twentieth century. The analysis of the teaching and research texts by Duhem, Poincaré and Hilbert on cont...

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

    Directory of Open Access Journals (Sweden)

    Paola Pugliatti


    Full Text Available 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 a few fragments have been preserved; their nature, therefore, remains dubious. Furthermore, anonymous documents of a different nature, also confusingly called ‘plots’, but compiled as reminders for the actors’ entrances during performance, have survived in six, mostly fragmentary, manuscripts. This article discusses these three kinds of preparatory texts in order to characterize their different nature and argues that, although suggestive, the idea of a derivation of the two kinds of English ‘plots’ from the scenari appears unconvincing; indeed, the compilation, in both contexts, of preparatory texts was simply an obvious and necessary measure in order to speed up procedures.

  8. The Renaissance Kidney-Nephrology in and about the Sixteenth Century. (United States)

    Eknoyan, Garabed


    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.

  9. Projectile motion in Diego Hurtado de Mendoza's Mecánica and new Renaissance dynamics

    Directory of Open Access Journals (Sweden)

    Iommi Echeverría, Virginia


    Full Text Available This article considers Diego Hurtado de Mendoza’s translation of the Aristotelian Mechanics in relation to the humanistic and scientific Italian environment of the Renaissance. From the analysis of the last problems on dynamics, it demonstrates the affinity with the works of Piccolomini and Cardano. It also shows the originality of the exegesis made by the Spanish author of Problem XXXIV, in which he combines latemedieval physics with the Aristotelian explanation.Este artículo examina la traducción hecha por Diego Hurtado de Mendoza de la Mecánica aristotélica en el contexto del ambiente científico-humanista italiano de mediados del siglo XVI. A partir del análisis de los últimos problemas sobre dinámica, se demuestra su estrecha relación con las obras de Piccolomini y Cardano; sugiriéndose además la originalidad de la interpretación hecha por el autor español del problema XXXIV basada en la combinación de la física tardomedieval y la explicación aristotélica.

  10. Galaxy Properties and UV Escape Fractions During Epoch of Reionization: Results from the Renaissance Simulations

    CERN Document Server

    Xu, Hao; Norman, Michael L; Ahn, Kyungjin; O'Shea, Brian W


    Cosmic reionization is thought to be primarily fueled by the first generations of galaxies. We examine their stellar and gaseous properties, focusing on the star formation rates and the escape of ionizing photons, as a function of halo mass, redshift, and environment using the full suite of the {\\it Renaissance Simulations} with an eye to provide better inputs to global reionization simulations. This suite, carried out with the adaptive mesh refinement code Enzo, is unprecedented in terms of their size and physical ingredients. The simulations probe overdense, average, and underdense regions of the universe of several hundred comoving Mpc$^3$, each yielding a sample of over 3,000 halos in the mass range $10^7 - 10^{9.5}~\\Ms$ at their final redshifts of 15, 12.5, and 8, respectively. In the process, we simulate the effects of radiative and supernova feedback from 5,000 to 10,000 metal-free (Population III) stars in each simulation. We find that halos as small as $10^7~\\Ms$ are able to form stars due to metal-l...

  11. Babson, Bahnson, the DeWitts and the General Relativity Renaissance (United States)

    Carter, Hamilton


    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.

  12. Media matters. (United States)

    Martinez, L M


    The impact of the mass media on woman's status was addressed at two 1995 conferences: the Fourth World Conference on Women, held in Beijing, China, and the Congress of the World Association for Christian Communication, held in Puebla, Mexico. The globalization process facilitated by the mass media has served to increase the power of patriarchy, with no advantages to the cause of women's rights. Coverage of popular movements has been suppressed out of deference to male-controlled governments. Coverage of the Beijing Conference highlighted celebrities and personal stories, to the exclusion of the economic and political issues under debate. Television has commodified women, reinforcing their oppression. On the other hand, the alternative media, which tend to be decentralized, democratic, low-cost, and low in technology, are presenting women as subjects rather than objects and deconstructing gender stereotypes. Of concern, however, is the tendency of computer technology to widen the gap between social classes and developed and developing countries. Women must use information networks to disseminate information on women's rights and strengthen the links between women throughout the world.

  13. Media Education Initiatives by Media Organizations: The Uses of Media Literacy in Hong Kong Media (United States)

    Chu, Donna; Lee, Alice Y. L.


    As more media organizations have engaged in media education, this paper investigates the goals and practices of these activities. This article coins media education initiatives by media organizations with the term "media-organization media literac"y (MOML). Four MOML projects in Hong Kong were selected for examination. Built on critical…

  14. Style and non-style in anatomical illustration: From Renaissance Humanism to Henry Gray. (United States)

    Kemp, Martin


    Style is a familiar category for the analysis of art. It is less so in the history of anatomical illustration. The great Renaissance and Baroque picture books of anatomy illustrated with stylish woodcuts and engravings, such as those by Charles Estienne, Andreas Vesalius and Govard Bidloo, showed figures in dramatic action in keeping with philosophical and theological ideas about human nature. Parallels can be found in paintings of the period, such as those by Titian, Michelangelo and Hans Baldung Grien. The anatomists also claimed to portray the body in an objective manner, and showed themselves as heroes of the discovery of human knowledge. Rembrandt's painting of Dr Nicholas Tulp is the best-known image of the anatomist as hero. The British empirical tradition in the 18th century saw William Cheselden and William Hunter working with techniques of representation that were intended to guarantee detailed realism. The ambition to portray forms life-size led to massive volumes, such as those by Antonio Mascagni. John Bell, the Scottish anatomist, criticized the size and pretensions of the earlier books and argued for a plain style adapted to the needs of teaching and surgery. Henry Gray's famous Anatomy of 1858, illustrated by Henry Vandyke Carter, aspired to a simple descriptive mode of functional representation that avoided stylishness, resulting in a style of its own. Successive editions of Gray progressively saw the replacement of Gray's method and of all his illustrations. The 150th anniversary edition, edited by Susan Standring, radically re-thinks the role of Gray's book within the teaching of medicine.

  15. A vaccinia virus renaissance: new vaccine and immunotherapeutic uses after smallpox eradication. (United States)

    Verardi, Paulo H; Titong, Allison; Hagen, Caitlin J


    In 1796, Edward Jenner introduced the concept of vaccination with cowpox virus, an Orthopoxvirus within the family Poxviridae that elicits cross protective immunity against related orthopoxviruses, including smallpox virus (variola virus). Over time, vaccinia virus (VACV) replaced cowpox virus as the smallpox vaccine, and vaccination efforts eventually led to the successful global eradication of smallpox in 1979. VACV has many characteristics that make it an excellent vaccine and that were crucial for the successful eradication of smallpox, including (1) its exceptional thermal stability (a very important but uncommon characteristic in live vaccines), (2) its ability to elicit strong humoral and cell-mediated immune responses, (3) the fact that it is easy to propagate, and (4) that it is not oncogenic, given that VACV replication occurs exclusively within the host cell cytoplasm and there is no evidence that the viral genome integrates into the host genome. Since the eradication of smallpox, VACV has experienced a renaissance of interest as a viral vector for the development of recombinant vaccines, immunotherapies, and oncolytic therapies, as well as the development of next-generation smallpox vaccines. This revival is mainly due to the successful use and extensive characterization of VACV as a vaccine during the smallpox eradication campaign, along with the ability to genetically manipulate its large dsDNA genome while retaining infectivity and immunogenicity, its wide mammalian host range, and its natural tropism for tumor cells that allows its use as an oncolytic vector. This review provides an overview of new uses of VACV that are currently being explored for the development of vaccines, immunotherapeutics, and oncolytic virotherapies.

  16. Stroke in Renaissance time: the case of Francesco I de' Medici. (United States)

    Arba, Francesco; Inzitari, Domenico; Barnett, Henry Joseph Macaulay; Lippi, Donatella


    Francesco I de' Medici (1541-1587), the second Grand Duke of Tuscany, was one of the members of the Medici family who ruled Florence during the centuries of the Renaissance. When, in 1857, all members of the Medici family were exhumed and definitively buried in the place where they still lie buried today, a painter, Giuseppe Moricci (Florence 1806-1879), who attended the ceremony, depicted the corpse of Francesco I in a perfect state of preservation. The painting shows a right spastic hemiparesis with a facial droop, a claw-hand appearance, the right shoulder internally rotated, the calf muscle wasted and the clubfoot confirmed by an orthopedic footwear in the coffin. The hemiparesis and consequent disability were likely concealed when Francesco I was alive, since in official portraits the Grand Duke appeared in perfect physical condition. However, chronicles reported that he had suffered from malaria and syphilis. Later in his life, temper and behavioral changes as well as emotional instability were documented, together with handwriting deterioration and seizures. We postulate that Francesco I had suffered from a stroke consequent to syphilis, a new aggressive and rapidly spreading infectious disease at that time in Italy. Francesco's governmental skills were presumably altered due to these diseases. Disability consequent to stroke was likely concealed by official portrayers and biographers of Francesco I during his life, consistent with the King's two bodies theory common since the Middle Ages: while the King's physical body is destined to die, the political one is everlasting. Infectious diseases have remained a leading cause of stroke in underdeveloped countries until recently, but noncommunicable causes are now prevailing worldwide.

  17. Books authored/co-authored and edited/co-edited by members of staff of the Department of Medieval/Medieval and Renaissance Archaeology, Aarhus University, 1971-2014

    DEFF Research Database (Denmark)

    Roesdahl, Else


    Chronologically organized list of books authored/co-authored and edited/co-edited by members of staff of the Department of Medieval and Renaissance Archaeology, Aarhus University, 1971-2014......Chronologically organized list of books authored/co-authored and edited/co-edited by members of staff of the Department of Medieval and Renaissance Archaeology, Aarhus University, 1971-2014...

  18. Corrosion problems with aqueous coolants, final report

    Energy Technology Data Exchange (ETDEWEB)

    Diegle, R B; Beavers, J A; Clifford, J E


    The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

  19. Under a Starry Vault. Warburg, Jung and the Renaissance of Ancient Paganisms at the Beginning of the 20th Century

    Directory of Open Access Journals (Sweden)

    Manuela Pallotto Strickland


    Full Text Available The paper tackles the controversial question of the affinities between the work of Aby Warburg and Carl Gustav Jung. Instead of focussing her interest exclusively on the concepts of collective memory and primordial images, though, the author critically compares the different ways Warburg and Jung looked at the renaissance of ancient practices of Paganism at the beginning of the Twentieth century, and questions the extent to which the cultural crisis heralded by Modernity, and the challenges brought about by secularisation influenced their reading of the revivals.

  20. The feasibility of a nuclear renaissance: A cost-benefit analysis of nuclear energy as a source of electricity



    Purpose: This article evaluates a possible global nuclear renaissance in the provision of electrical energy.Problem investigated: Several countries, such as South Africa, are experiencing problems in the provision of electricity and the maintenance of the infrastructure to answer growing demand. This article investigates an alternative, which was popular in the 1970s and provides clean energy.Methodology: The study firstly evaluates the main arguments set by anti-nuclear activists critically....