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Sample records for synthesis 208pb64ni n271ds

  1. Organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.E.

    1991-01-01

    This paper reports on reactions of organoboranes. Organoboron routes to unsaturated hydrocarbons. Boronic ester homologation. Properties of organosilicon compounds. Alkene synthesis (Peterson olefination). Allylsilanes and acylsilanes.

  2. Fire Synthesis

    Indian Academy of Sciences (India)

    1000ºC or special infrastructure which require careful maintenance. In such a situation fire synthesis is a simpler method that can be adopted for the bulk production of high purity alumina and related oxides. Fire Synthesis. Preparation of Alumina ...

  3. Organic synthesis

    International Nuclear Information System (INIS)

    Lallemand, J.Y.; Fetizon, M.

    1988-01-01

    The 1988 progress report of the Organic Synthesis Chemistry laboratory (Polytechnic School, France), is presented. The laboratory activities are centered on the chemistry of natural products, which have a biological activity and on the development of new reactions, useful in the organic synthesis. The research works involve the following domains: the natural products chemistry which are applied in pharmacology, the plants and insects chemistry, the organic synthesis, the radical chemistry new reactions and the bio-organic physicochemistry. The published papers, the congress communications and the thesis are listed [fr

  4. Fire Synthesis

    Indian Academy of Sciences (India)

    her PhD degree from. Bangalore University. She is currently working as a Research Associate at the Department of. Inorganic and Physical. Chemistry, Indian. Institute of Science,. Bangalore, on the synthesis of .... This method uses the experiences of propellant chemistry in making the redox mixture. The . stoichiometry or ...

  5. Fire Synthesis

    Indian Academy of Sciences (India)

    special infrastructure which require careful maintenance. In such situation fire synthesis is a simpler method that can be adopted for the bulk production of high purity .... reaction between Ti and B to form titanium boride. The reaction between titanium (fuel- electron donor) and boron (oxidiser-electron acceptor) once initiated ...

  6. Fire Synthesis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Fire Synthesis - Preparation of Alumina Products. Tanu Mimani. Volume 16 Issue 12 December 2011 pp 1324-1332. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/016/12/1324-1332 ...

  7. Fire Synthesis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Fire Synthesis - Preparation of Alumina Products. Tanu Mimani. General Article Volume 5 Issue 2 February 2000 pp 50-57. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/005/02/0050-0057 ...

  8. Total synthesis of ciguatoxin.

    Science.gov (United States)

    Hamajima, Akinari; Isobe, Minoru

    2009-01-01

    Something fishy: Ciguatoxin (see structure) is one of the principal toxins involved in ciguatera poisoning and the target of a total synthesis involving the coupling of three segments. The key transformations in this synthesis feature acetylene-dicobalthexacarbonyl complexation.

  9. Synthesis of Mechanisms

    DEFF Research Database (Denmark)

    Hansen, John Michael

    1999-01-01

    These notes describe an automated procedure for analysis and synthesis of mechanisms. The analysis method is based on the body coordinate formulation, and the synthesis is based on applying optimization methods, used to minimize the difference between an actual and a desired behaviour......These notes describe an automated procedure for analysis and synthesis of mechanisms. The analysis method is based on the body coordinate formulation, and the synthesis is based on applying optimization methods, used to minimize the difference between an actual and a desired behaviour...

  10. Total Synthesis of Avrainvilleol.

    Science.gov (United States)

    Wegener, Aaron; Miller, Kenneth A

    2017-11-03

    The first total synthesis of the marine natural product avrainvilleol is reported. The total synthesis features the first application of the transition-metal-free coupling of a tosyl hydrazone and a boronic acid to the preparation of a complex natural product, and the first example of this coupling with a hindered diortho substituted hydrazone substrate.

  11. Difluoromethylenephosphonates: synthesis and transformations

    International Nuclear Information System (INIS)

    Chunikhin, Konstantin S; Kadyrov, A A; Pasternak, P V; Chkanikov, Nikolai D

    2010-01-01

    The data on the synthesis of organic compounds containing the difluoromethylenephosphonate group are analyzed and generalized. The attention is focused on the introduction of this group into various organic molecules and subsequent transformations of the compounds thus formed. Individual sections are devoted to the synthesis of heterocyclic compounds and analogues of natural substances containing difluoromethylenephosphonate groups.

  12. Synthesis of Isoiminosugars

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Godskesen, Michael Anders; Lundt, Inge

    1998-01-01

    A short synthesis of isoiminosugars have been developed. Bromolactones are diastereoselectively alkylated at C-2 followed by ring closure to the corresponding lactams. Reduction of these then gives isoiminosugars......A short synthesis of isoiminosugars have been developed. Bromolactones are diastereoselectively alkylated at C-2 followed by ring closure to the corresponding lactams. Reduction of these then gives isoiminosugars...

  13. Synthesis of oligonucleotide phosphorodithioates

    DEFF Research Database (Denmark)

    Beaton, G.; Brill, W. K D; Grandas, A.

    1991-01-01

    The synthesis of DNA containing sulfur at the two nonbonding internucleotide valencies is reported. Several different routes using either tervalent or pentavalent mononucleotide synthons are described.......The synthesis of DNA containing sulfur at the two nonbonding internucleotide valencies is reported. Several different routes using either tervalent or pentavalent mononucleotide synthons are described....

  14. VHDL for logic synthesis

    CERN Document Server

    Rushton, Andrew

    2011-01-01

    Many engineers encountering VHDL (very high speed integrated circuits hardware description language) for the first time can feel overwhelmed by it. This book bridges the gap between the VHDL language and the hardware that results from logic synthesis with clear organisation, progressing from the basics of combinational logic, types, and operators; through special structures such as tristate buses, register banks and memories, to advanced themes such as developing your own packages, writing test benches and using the full range of synthesis types. This third edition has been substantially rewritten to include the new VHDL-2008 features that enable synthesis of fixed-point and floating-point hardware. Extensively updated throughout to reflect modern logic synthesis usage, it also contains a complete case study to demonstrate the updated features. Features to this edition include: * a common VHDL subset which will work across a range of different synthesis systems, targeting a very wide range of technologies...

  15. Asymmetric synthesis v.4

    CERN Document Server

    Morrison, James

    1984-01-01

    Asymmetric Synthesis, Volume 4: The Chiral Carbon Pool and Chiral Sulfur, Nitrogen, Phosphorus, and Silicon Centers describes the practical methods of obtaining chiral fragments. Divided into five chapters, this book specifically examines initial chiral transmission and extension. The opening chapter describes the so-called chiral carbon pool, the readily available chiral carbon fragments used as building blocks in synthesis. This chapter also provides a list of 375 chiral building blocks, along with their commercial sources, approximate prices, and methods of synthesis. Schemes involving

  16. SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL ...

    African Journals Online (AJOL)

    Preferred Customer

    E-mail: a-ahmadi@kiau.ac.ir; ahmadikiau@yahoo.com. SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL EVALUATION OF. SOME NOVEL DERIVATIVES OF 2-BROMOMETHYL-BENZIMIDAZOLE. Abbas Ahmadi*. Department of Medicinal Chemistry, Pharmaceutical Sciences Branch, Islamic Azad University,.

  17. 2002 Annual report: synthesis

    International Nuclear Information System (INIS)

    2003-01-01

    This synthesis of the Annual Report 2002 presents information of the main activities on the scope of the radiation protection and nuclear safety of the Nuclear Regulatory Authority (ARN) of the Argentina during 2002

  18. 2001 Annual report: synthesis

    International Nuclear Information System (INIS)

    2001-01-01

    This synthesis of the Annual Report 2001 presents information of the main activities on the scope of the radiation protection and nuclear safety of the Nuclear Regulatory Authority (ARN) of the Argentina during 2001

  19. 2000 Annual report: synthesis

    International Nuclear Information System (INIS)

    2001-01-01

    This synthesis of the Annual Report 2000 present information of the main activities on the scope of the radiation protection and nuclear safety of the Nuclear Regulatory Authority (NRA) of the Argentina during 2000

  20. Synthesis of Acetylhomoagmatine

    Directory of Open Access Journals (Sweden)

    Carmenza Duque

    2006-08-01

    Full Text Available Abstract: The first total synthesis of acetylhomoagmatine, a natural product isolated form the methanolic extracts from the sponge Cliona celata, is performed in four steps in a very high yield.

  1. Instrument Modeling and Synthesis

    Science.gov (United States)

    Horner, Andrew B.; Beauchamp, James W.

    During the 1970s and 1980s, before synthesizers based on direct sampling of musical sounds became popular, replicating musical instruments using frequency modulation (FM) or wavetable synthesis was one of the “holy grails” of music synthesis. Synthesizers such as the Yamaha DX7 allowed users great flexibility in mixing and matching sounds, but were notoriously difficult to coerce into producing sounds like those of a given instrument. Instrument design wizards practiced the mysteries of FM instrument design.

  2. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    International Nuclear Information System (INIS)

    Dolmatov, Valerii Yu

    2007-01-01

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  3. Synthesis of phenanthrenes

    International Nuclear Information System (INIS)

    Clarke, C.

    1983-01-01

    A new and improved synthesis of 7-methoxy-12-methyl-2-oxo-2,3,4,9,10,12-hexahydrophenanthrene has been described. The compound is an important intermediate for the synthesis of many di- and tri-terpenes, and was required in this work for the synthesis of 17-acetyl-5α-etiojerva-12,14,16-trien-3β-ol. This compound is a known starting material for the synthesis of the veratrum alkaloids jervine, veratramine and verarine. Two synthetic routes to the synthesis of 7-methoxy-12-methyl-2-oxo-2,3,4,9,10,12-hexahydrophenanthrene were investigated. The first route required preparation of the intermediate 1-(5-methyl-2-furyl)-3-(3'-methoxyphenyl)propane which, by simple manipulation involving mainly the furan ring, gave the desired compound in 33% yield. All of the reactions involved are suitable for both large and small scale preparations. The synthesis of 17-acetyl-5α-etiojerva-12,14,16-trien-3B-ol can be achieved by the hyde and 3-methoxyacetophenone, followed by hydrogeneration and Wolff-Kishner reduction. A less successful synthesis of the above compound was achieved by condensing the Grignard derivative of 2-(3'-methoxyphenyl)ethyl bromide with 5-methylfurfuraldehyde to form a furyl alcohol, which was oxidized and reduced to give 1-(5-methyl-2-furyl)-3-(3'-methoxyphenyl)propane in only 7% overall yield, but the starting materials are inexpensive and readily available. The compound was also prepared in 40% yield by condensing 2-lithio-5-methylfuran with 3-(3'methoxyphenyl)propyl bromide. An appendix describes the reaction of 3-ethoxy-cyclohex-2-en-1-one with ethylmagnesium bromide, followed by aromatization. A second appendix describes the reductive alkylation of 8-methoxy-12-methyl-2-oxo-2,3,4,9,10,12-hexahydrophenanthrene

  4. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  5. Synthesis of organosilicon compounds

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, G. [Iowa State Univ., Ames, IA (United States)

    1996-01-01

    Silicon-containing polymers have been a focus of synthesis and study in Dr. Barton`s group because of their chemistry and properties which are not offered by other systems or materials. For example, the polymer -[-SiMe2C≡C-]n-can be easily processed to films or fibers from melt or solution, and thermally converted to a SiC-containing ceramic in high yield at high temperature. In recent years, carbosilane dendritic polymers have been of great interests in many research groups. However, no synthesis of carbosilane dendrimers with functionalties both inside and outside the dendrimer has been reported. Functionality is very important in the synthesis of preceramic polymers. This thesis will be devoted to exploring several new organosilicon polymer systems.

  6. Total Synthesis of Strychnine.

    Science.gov (United States)

    Lee, Geun Seok; Namkoong, Gil; Park, Jisook; Chen, David Y-K

    2017-11-16

    The total synthesis of the flagship Strychnos indole alkaloid, strychnine, has been accomplished. The developed synthetic sequence features a novel vinylogous 1,4-addition, a challenging iodinium salt mediated silyl enol ether arylation, a palladium-catalyzed Heck reaction, and a streamlined late-stage conversion to strychnine. Furthermore, an application of asymmetric counterion-directed catalysis (ACDC) in the context of target-oriented organic synthesis has been rendered access to an optically active material. The synthetic sequence described herein represents the most concise entry to optically active strychnine to date. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Supercritical Synthesis of Biodiesel

    Directory of Open Access Journals (Sweden)

    Michel Vaultier

    2012-07-01

    Full Text Available The synthesis of biodiesel fuel from lipids (vegetable oils and animal fats has gained in importance as a possible source of renewable non-fossil energy in an attempt to reduce our dependence on petroleum-based fuels. The catalytic processes commonly used for the production of biodiesel fuel present a series of limitations and drawbacks, among them the high energy consumption required for complex purification operations and undesirable side reactions. Supercritical fluid (SCF technologies offer an interesting alternative to conventional processes for preparing biodiesel. This review highlights the advances, advantages, drawbacks and new tendencies involved in the use of supercritical fluids (SCFs for biodiesel synthesis.

  8. Direct dimethyl ether synthesis from synthesis gas: The influence of methanol dehydration on methanol synthesis reaction

    OpenAIRE

    Dadgar, Farbod; Myrstad, Rune; Pfeifer, Peter; Holmen, Anders; Venvik, Hilde Johnsen

    2016-01-01

    Direct dimethyl ether (DME) synthesis from synthesis gas is studied with regard to potential effects of methanol dehydration on methanol formation and copper-based catalyst performance. For this, the influence of the operating conditions (space velocity, temperature, pressure, time-on-stream and syngas composition) on activity, selectivity and stability of the catalyst was studied and compared for methanol synthesis and direct DME synthesis. The advantage of the direct over the two-step DME s...

  9. An Approach to Interface Synthesis

    DEFF Research Database (Denmark)

    Madsen, Jan; Hald, Bjarne

    1995-01-01

    Presents a novel interface synthesis approach based on a one-sided interface description. Whereas most other approaches consider interface synthesis as optimizing a channel to existing client/server modules, we consider the interface synthesis as part of the client/server module synthesis (which...... may contain the re-use of existing modules). The interface synthesis approach describes the basic transformations needed to transform the server interface description into an interface description on the client side of the communication medium. The synthesis approach is illustrated through a point......-to-point communication, but is applicable to synthesis of a multiple client/server environment. The interface description is based on a formalization of communication events....

  10. Enzymatic synthesis of vanillin

    NARCIS (Netherlands)

    van den Heuvel, RHH; Fraaije, MW; Laane, C; van Berkel, WJH; Heuvel, Robert H.H. van den; Berkel, Willem J.H. van

    Due to increasing interest in natural vanillin, two enzymatic routes for the synthesis of vanillin were developed. The flavoprotein vanillyl alcohol oxidase (VAO) acts on a wide range of phenolic compounds and converts both creosol and vanillylamine to vanillin with high yield. The VAO-mediated

  11. Enzymatic synthesis of vanillin

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Fraaije, M.W.; Laane, C.; Berkel, van W.J.H.

    2001-01-01

    Due to increasing interest in natural vanillin, two enzymatic routes for the synthesis of vanillin were developed. The flavoprotein vanillyl alcohol oxidase (VAO) acts on a wide range of phenolic compounds and converts both creosol and vanillylamine to vanillin with high yield. The VAO-mediated

  12. Design synthesis exercise 2012

    NARCIS (Netherlands)

    Melkert, J.A.

    2013-01-01

    The design synthesis exercise forms the closing piece of the third year of the Bachelor degree curriculum of the Faculty of Aerospace Engineering at TU Delft. In this exercise the students learn to apply their acquired knowledge from all aerospace disciplines in one complete design. The object of

  13. Asymmetric synthesis of acetomycin

    NARCIS (Netherlands)

    Kinderman, S.S.; Feringa, B.L.

    1998-01-01

    The synthesis of (-)-acetomycin, a highly functionalized γ-lactone with antitumor activity, was achieved in five steps with nearly complete enantioselectivity. The key step was realized by a large scale lipase R catalyzed esterification of 5-hydroxy-4-methyl-2(5H)-furanone providing

  14. Synthesis de 1-dotriacotanol

    International Nuclear Information System (INIS)

    Hernandez, L.; Gonzalez, J.C.

    1996-01-01

    In order to prepare isotopic labeled long chain aliphatic primary alcohol's, the synthesis overall yielding and chemical purity of 1-dotriacotanol were 41% and 98%, respectively. This procedure is very useful for carbon-14 and tritium labeling at Beta position of saturated fatty alcohol's

  15. Synthesis of Camalexin

    Directory of Open Access Journals (Sweden)

    V. Kovacik

    2001-08-01

    Full Text Available In this paper we describe a new method for the synthesis of camalexin (1 based on the reaction of 1-(tert-butoxycarbonylindole-3-carboxaldehyde with methyl Lcysteinate hydrochloride, followed by oxidation and decarboxylation. Compounds 1, and intermediates 5-7 were identified by elemental analysis, 1H NMR, 13C NMR and mass spectroscopy.

  16. Synthesis of Camalexin

    OpenAIRE

    Dzurilla, M.; Kutschy, P.; Zaletova, J.; Ruzinsky, M.; Kovacik, V.

    2001-01-01

    In this paper we describe a new method for the synthesis of camalexin (1) based on the reaction of 1-(tert-butoxycarbonyl)indole-3-carboxaldehyde with methyl Lcysteinate hydrochloride, followed by oxidation and decarboxylation. Compounds 1, and intermediates 5-7 were identified by elemental analysis, 1H NMR, 13C NMR and mass spectroscopy.

  17. Synthesis of acrylic prepolymer

    International Nuclear Information System (INIS)

    Hussin bin Mohd Nor; Dahlan bin Haji Mohd; Mohamad Hilmi bin Mahmood.

    1988-04-01

    An acrylic prepolymer was synthesized from glycidyl methacrylate (GMA), butyl methacrylate (BMA), methyl methacrylate (MMA) and acrylic acid (AA). Butyl acetate (BAc), benzoyl peroxide (BzO), 4-methoxyphenol (MPh) and triethylamine (TEA) were used as solvent, initiator, inhibitor and catalyst respectively. Observations of the synthesis leading to the formation of acrylic prepolymer are described. (author)

  18. Synthesis, characterization and properties

    Indian Academy of Sciences (India)

    Unknown

    C−H⋅⋅⋅O bonds leading to an intricate hydrogen bonding network. Keywords. Synthesis .... in the refinement riding on their respective parent atoms. ..... nent peaks at 326 and 255 nm which can be assigned to transitions of the intramolecularly hydrogen-bon- ded salicylidenimino chromophore. Cotton effects of negative ...

  19. Synthesis of new radiotracers

    International Nuclear Information System (INIS)

    Chahed, Ahlem

    2008-01-01

    The brain's sensibility besides to the rigorous selectivity of changes taking place on brain's barriers leads us to synthesis specifics radiotracers based on diamine ethylene and marked with technetium radioisotope to form a radiotracer able to pass these barriers and diagnose illnesses in an early stage. These radiotracers are tested by a biodistribution on a small animal to be ratified. (Author)

  20. Synthesis of arabinoxylan fragments

    DEFF Research Database (Denmark)

    Underlin, Emilie Nørmølle; Böhm, Maximilian F.; Madsen, Robert

    , or production of commercial chemicals which are mainly obtained from fossil fuels today.The arbinoxylan fragments have a backbone of β-1,4-linked xylans with α-L-arabinose units attached at specific positions. The synthesis ultilises an efficient synthetic route, where all the xylan units can be derived from D...

  1. Total synthesis of aquatolide

    NARCIS (Netherlands)

    Saya, J.M.; Vos, K.; Klein Nijenhuis, R.A.; van Maarseveen, J.H.; Ingemann, S.; Hiemstra, H.

    2015-01-01

    A total synthesis of the sesquiterpene lactone aquatolide has been accomplished. The central step is an intramolecular [2 + 2]-photocycloaddition of an allene onto an alpha,beta-unsaturated delta-lactone. Other key steps are an intramolecular Horner-Wadsworth-Emmons reaction to close the lactone and

  2. The synthesis of gemcitabine.

    Science.gov (United States)

    Brown, Kylie; Dixey, Michael; Weymouth-Wilson, Alex; Linclau, Bruno

    2014-03-31

    Gemcitabine is a fluorinated nucleoside currently administered against a number of cancers. It consists of a cytosine base and a 2-deoxy-2,2-difluororibose sugar. The synthetic challenges associated with the introduction of the fluorine atoms, as well as with nucleobase introduction of 2,2-difluorinated sugars, combined with the requirement to have an efficient process suitable for large scale synthesis, have spurred significant activity towards the synthesis of gemcitabine exploring a wide variety of synthetic approaches. In addition, many methods have been developed for selective crystallisation of diastereomeric (including anomeric) mixtures. In that regard, the 2-deoxy-2,2-difluororibose sugar is one of the most investigated fluorinated carbohydrates in terms of its synthesis. The versatility of synthetic methods employed is illustrative of the current state of the art of fluorination methodology for the synthesis of CF2-containing carbohydrates, and involves the use of fluorinated building blocks, as well as nucleophilic and electrophilic fluorination of sugar precursors. Copyright © 2014. Published by Elsevier Ltd.

  3. Synthesis of the catalyst

    Indian Academy of Sciences (India)

    Admin

    62 11; Palhagen S, Canger R, Henriksen O, Van Parys J A, Riviere M E and Karolchyk M A 2001 Rufinamide: a double-blind, placebo-controlled proof of principle trial in patients with epilepsy; Epilepsy Res. 43, 115; Bakunov S A, Bakunova S M, Wenzler T, Ghebru M, Werbovetz K A, Brun R and Tidwell R R 2010 Synthesis ...

  4. Industrial scale gene synthesis.

    Science.gov (United States)

    Notka, Frank; Liss, Michael; Wagner, Ralf

    2011-01-01

    The most recent developments in the area of deep DNA sequencing and downstream quantitative and functional analysis are rapidly adding a new dimension to understanding biochemical pathways and metabolic interdependencies. These increasing insights pave the way to designing new strategies that address public needs, including environmental applications and therapeutic inventions, or novel cell factories for sustainable and reconcilable energy or chemicals sources. Adding yet another level is building upon nonnaturally occurring networks and pathways. Recent developments in synthetic biology have created economic and reliable options for designing and synthesizing genes, operons, and eventually complete genomes. Meanwhile, high-throughput design and synthesis of extremely comprehensive DNA sequences have evolved into an enabling technology already indispensable in various life science sectors today. Here, we describe the industrial perspective of modern gene synthesis and its relationship with synthetic biology. Gene synthesis contributed significantly to the emergence of synthetic biology by not only providing the genetic material in high quality and quantity but also enabling its assembly, according to engineering design principles, in a standardized format. Synthetic biology on the other hand, added the need for assembling complex circuits and large complexes, thus fostering the development of appropriate methods and expanding the scope of applications. Synthetic biology has also stimulated interdisciplinary collaboration as well as integration of the broader public by addressing socioeconomic, philosophical, ethical, political, and legal opportunities and concerns. The demand-driven technological achievements of gene synthesis and the implemented processes are exemplified by an industrial setting of large-scale gene synthesis, describing production from order to delivery. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Voice synthesis application

    Science.gov (United States)

    Lightstone, P. C.; Davidson, W. M.

    1982-04-01

    The military detection assessment laboratory houses an experimental field system which assesses different alarm indicators such as fence disturbance sensors, MILES cables, and microwave Racons. A speech synthesis board which could be interfaced, by means of a computer, to an alarm logger making verbal acknowledgement of alarms possible was purchased. Different products and different types of voice synthesis were analyzed before a linear predictive code device produced by Telesensory Speech Systems of Palo Alto, California was chosen. This device is called the Speech 1000 Board and has a dedicated 8085 processor. A multiplexer card was designed and the Sp 1000 interfaced through the card into a TMS 990/100M Texas Instrument microcomputer. It was also necessary to design the software with the capability of recognizing and flagging an alarm on any 1 of 32 possible lines. The experimental field system was then packaged with a dc power supply, LED indicators, speakers, and switches, and deployed in the field performing reliably.

  6. Synthesis of quantum dots

    Science.gov (United States)

    McDaniel, Hunter

    2017-10-17

    Common approaches to synthesizing alloyed quantum dots employ high-cost, air-sensitive phosphine complexes as the selenium precursor. Disclosed quantum dot synthesis embodiments avoid these hazardous and air-sensitive selenium precursors. Certain embodiments utilize a combination comprising a thiol and an amine that together reduce and complex the elemental selenium to form a highly reactive selenium precursor at room temperature. The same combination of thiol and amine acts as the reaction solvent, stabilizing ligand, and sulfur source in the synthesis of quantum dot cores. A non-injection approach may also be used. The optical properties of the quantum dots synthesized by this new approach can be finely tuned for a variety of applications by controlling size and/or composition of size and composition. Further, using the same approach, a shell can be grown around a quantum dot core that improves stability, luminescence efficiency, and may reduce toxicity.

  7. Prebiotic synthesis of histidine

    Science.gov (United States)

    Shen, C.; Yang, L.; Miller, S. L.; Oro, J.

    1990-01-01

    The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

  8. Distributed PROMPT-LTL Synthesis

    Directory of Open Access Journals (Sweden)

    Swen Jacobs

    2016-09-01

    Full Text Available We consider the synthesis of distributed implementations for specifications in Prompt Linear Temporal Logic (PROMPT-LTL, which extends LTL by temporal operators equipped with parameters that bound their scope. For single process synthesis it is well-established that such parametric extensions do not increase worst-case complexities. For synchronous systems, we show that, despite being more powerful, the distributed realizability problem for PROMPT-LTL is not harder than its LTL counterpart. For asynchronous systems we have to consider an assume-guarantee synthesis problem, as we have to express scheduling assumptions. As asynchronous distributed synthesis is already undecidable for LTL, we give a semi-decision procedure for the PROMPT-LTL assume-guarantee synthesis problem based on bounded synthesis.

  9. Microwave multicomponent synthesis.

    Science.gov (United States)

    Hügel, Helmut M

    2009-12-01

    In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS) that have been achieved over the last five years.

  10. Microwave Multicomponent Synthesis

    Directory of Open Access Journals (Sweden)

    Helmut M. Hügel

    2009-12-01

    Full Text Available In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS that have been achieved over the last five years.

  11. Microwave Multicomponent Synthesis

    OpenAIRE

    Helmut M. Hügel

    2009-01-01

    In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS) that have been achiev...

  12. Synthesis of functionalised sulfonamides

    OpenAIRE

    Mok, B. L.

    2008-01-01

    Sulfonamides are important therapeutic agents and have a diverse array of biological functions in biology and medicine. Their means of synthesis has often involved the use of unstable sulfonyl chloride species; however, recent research has established pentafluorophenyl (PFP) sulfonate esters as a useful stable alternative to such species. This thesis describes the use of PFP vinyl sulfonate in a [3+2] cycloaddition with a variety of N-methyl-nitrones, providing access to the corresponding...

  13. Phase contrast image synthesis

    DEFF Research Database (Denmark)

    Glückstad, J.

    1996-01-01

    A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

  14. Integrated methanol synthesis

    International Nuclear Information System (INIS)

    Jaeger, W.

    1982-01-01

    This invention concerns a plant for methanol manufacture from gasified coal, particularly using nuclear power. In order to reduce the cost of the hydrogen circuits, the methanol synthesis is integrated in the coal gasification plant. The coal used is gasified with hydration by means of hydrogen and the crude gas emerging, after cooling and separating the carbon dioxide and hydrogen sulphide, is mixed with the synthetic gas leaving the methane cracking furnace. This mixture is taken to the methanol synthesis and more than 90% is converted into methanol in one pass. The gas mixture remaning after condensation and separation of methanol is decomposed into three fractions in low temperature gas decomposition with a high proportion of unconverted carbon monoxide. The flow of methane is taken to the cracking furnace with steam, the flow of hydrogen is taken to the hydrating coal gasifier, and the flow of carbon monoxide is taken to the methanol synthesis. The heat required for cracking the methane can either be provided by a nuclear reactor or by the coke left after hydrating gasification. (orig./RB) [de

  15. Gold Nanoparticle Microwave Synthesis

    International Nuclear Information System (INIS)

    Krantz, Kelsie E.; Christian, Jonathan H.; Coopersmith, Kaitlin; Washington II, Aaron L.; Murph, Simona H.

    2016-01-01

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  16. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.

  17. Application of chalcones in heterocycles synthesis: Synthesis of 2 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 125; Issue 3. Application of chalcones in heterocycles synthesis: Synthesis of 2-(isoxazolo, pyrazolo and pyrimido) substituted analogues of 1,4-benzodiazepin-5-carboxamides linked through an oxyphenyl bridge. N Kaur D Kishore. Volume 125 Issue 3 May 2013 pp ...

  18. Gene Synthesis with HG Khorana

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 12. Gene Synthesis with H G Khorana. Marvin H Caruthers. General Article Volume 17 Issue 12 December 2012 pp ... Keywords. Chemical synthesis of genes for yeast alanine tRNA and E. coli supressor tRNA; Khorana's philosophy on science.

  19. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Blazer, R.M.; Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1982-01-01

    Described is a scheme for the synthesis of L-arginine-1- 13 C utilizing methods developed for the synthesis of L-ornithine-1- 13 C from L-ornithine-2- 13 C and then converting ornithine into arginine with the enzyme acylase

  20. Chemical synthesis on SU-8

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Taveras, Kennedy; Thastrup, Ole

    2011-01-01

    In this paper we describe a highly effective surface modification of SU-8 microparticles, the attachment of appropriate linkers for solid-supported synthesis, and the successful chemical modification of these particles via controlled multi-step organic synthesis leading to molecules attached...

  1. Organic Synthesis using Clay Catalysts

    Indian Academy of Sciences (India)

    His work includes organic synthesis and reaction mechanisms mainly in the area of organosilicon chemistry. Presently he is also working on organic synthesis under solvent- free conditions and using clay-catalyses. Keywords. Montmorillonite, ion-exchange, clay-nanomaterials, dehydration pyrolysis, rearrangement, steric.

  2. First total synthesis of Boehmenan

    Indian Academy of Sciences (India)

    The first total synthesis of dilignan Boehmenan has been achieved. A biomimetic oxidative coupling of the ferulic acid methyl ester in the presence of silver oxide is the crucial step in the synthesis sequence, generating the dihydrobenzofuran skeleton. Hydroxyl group was protected with DHP and reducted with LiAlH4 to ...

  3. SHORT COMMUNICATION SYNTHESIS AND ANTIBACTERIAL ...

    African Journals Online (AJOL)

    Admin

    a. sodium nitrite, b. ethylacetoacetate, c. phenyl hydrazine, d. hydrazine hydrate, e. hydroxyl- amine hydrochloride, f. Salycylaldehye, g. chloroacetyl chloride, h. thioglycollic acid. Scheme 1. Synthesis of heterocyclic derivatives of sulfanilamide. Synthesis of compound 1 and 2a-e were done as per the reported method [7-8] ...

  4. Total synthesis of proposed auranthine.

    Science.gov (United States)

    Kshirsagar, Umesh A; Puranik, Vedavati G; Argade, Narshinha P

    2010-04-16

    Starting from CBz-protected glutamic anhydride and Boc-protected o-aminobenzyl amine, the first total synthesis of proposed structure of auranthine has been reported. An intramolecular aza-Wittig reaction involving a lactam carbonyl group that delivered the diazepine core unit was the key step in the synthesis.

  5. First total synthesis of Boehmenan

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 3 ... The first total synthesis of dilignan Boehmenan has been achieved. A biomimetic oxidative coupling of the ferulic acid methyl ester in the presence of silver oxide is the crucial step in the synthesis sequence, generating the dihydrobenzofuran skeleton.

  6. Stereoselective total synthesis of sphingolipids

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 128; Issue 11. Stereoselective total synthesis of sphingolipids. PARAMESH JANGILI PERLA ... Keywords. 1,2-Diacetyl D-erythro-sphinganine; 1,2-diacetyl L-threo-sphinganine; D-erythro-sphinganine triacetate; sphingolipids; total synthesis; Garner aldehyde.

  7. Chemical Synthesis of Antimicrobial Peptides.

    Science.gov (United States)

    Münzker, Lena; Oddo, Alberto; Hansen, Paul R

    2017-01-01

    Solid-phase peptide synthesis (SPPS) is the method of choice for chemical synthesis of peptides. In this nonspecialist review, we describe commonly used resins, linkers, protecting groups, and coupling reagents in 9-fluorenylmethyloxycarbonyl (Fmoc) SPPS. Finally, a detailed protocol for manual Fmoc SPPS is presented.

  8. Methyltrioctylammonium chloride catalysed sonochemical synthesis ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 125; Issue 5. Methyltrioctylammonium chloride catalysed sonochemical synthesis of acridine diones ... The greener, clean and efficient protocol for the synthesis of acridine diones derivatives has been achieved by reacting aromatic aldehyde, dimedone and amines ...

  9. Lactobacillusassisted synthesis of titanium nanoparticles

    Directory of Open Access Journals (Sweden)

    Jha Anal

    2007-01-01

    Full Text Available AbstractAn eco-friendlylactobacillussp. (microbe assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  10. Microemulsion Synthesis of Nanoparticles

    Directory of Open Access Journals (Sweden)

    Gotić, M.

    2013-11-01

    Full Text Available Nanoparticles and nanomaterials have wide applications in electronics, physics, material design, being also utilized as sensors, catalysts, and more and more in biomedicine. Microemulsions are an exceptionally suitable medium for the synthesis of nanoparticles due to their thermodynamical stability, great solubility of both polar and nonpolar components, as well as their ability to control the size, dispersity and shape of the particles. This review presents microemulsion techniques for the synthesis of inorganic nanoparticles. It takes place in water-in-oil microemulsions by mixing one microemulsion with a cationic precursor, and the other with a precipitating or reducing agent, or by direct addition of reducing agents or gas (O2, NH3 ili CO2 into microemul sion (Fig. 1. Metal nanoparticles are used as catalysts, sensors, ferrofluids etc. They are produced by reducing the metal cation with a suitable reducing agent. In a similar way, one can prepare nanoparticles of alloys from the metal salts, provided that the metals are mutually soluble. The microemulsion technique is also suitable for depositing nanoparticles onto various surfaces. Highly active catalysts made from nanoparticles of Pt, Pd, Rh and other noble metals may be obtained in this way. Metal oxides and hydroxides may be prepared by hydrolysis or precipitation in the water core of microemulsion. Precipitation can be initiated by adding the base or precipitating agent into the microemulsion with water solution of metal ions. Similarly, nanoparticles may be prepared of sulphides, halogenides, cyanides, carbonates, sulphates and other insoluble metal salts. To prevent oxidation of nanoparticles, especially Fe, the particles are coated with inert metals, oxides, various polymers etc. Coating may provide additional functionality; e.g. coating with gold allows subsequent functionalization with organic compounds containing sulphur, due to the strong Au–S bond. Polymer coatings decrease

  11. Total Synthesis of Hyperforin.

    Science.gov (United States)

    Ting, Chi P; Maimone, Thomas J

    2015-08-26

    A 10-step total synthesis of the polycyclic polyprenylated acylphloroglucinol (PPAP) natural product hyperforin from 2-methylcyclopent-2-en-1-one is reported. This route was enabled by a diketene annulation reaction and an oxidative ring expansion strategy designed to complement the presumed biosynthesis of this complex meroterpene. The described work enables the preparation of a highly substituted bicyclo[3.3.1]nonane-1,3,5-trione motif in only six steps and thus serves as a platform for the construction of easily synthesized, highly diverse PPAPs modifiable at every position.

  12. Dibutylphosphoric acid synthesis

    International Nuclear Information System (INIS)

    Elias, H.; Boumaout, R.; Kellou, N.; Amedjkouh, A.; Hamidi, A.

    1995-09-01

    This work consists on the synthesis of dibutylphosphoric acis (DBP) by reaction of butanol with phosphorus pentoxid and on its separation by liquid-liquid extraction. It also deals with the characterization of DBP by some physicochemical analysis methods such as : chromatography, pH-metry and infrared and ultraviolet spectrophotometries. this study showed essentialy, that DBP can be formed in an appreciable amount (55%) when the reaction is realised with butanol/pentoxid molar ratio upper than 3 at temperature of 95 C

  13. Catalytic Oligopeptide Synthesis.

    Science.gov (United States)

    Liu, Zijian; Noda, Hidetoshi; Shibasaki, Masakatsu; Kumagai, Naoya

    2018-02-02

    Waste-free catalytic assembly of α-amino acids is fueled by a multiboron catalyst that features a characteristic B 3 NO 2 heterocycle, providing a versatile catalytic protocol wherein functionalized natural α-amino acid units are accommodated and commonly used protecting groups are tolerated. The facile dehydrative conditions eliminate the use of engineered peptide coupling reagents, exemplifying a greener catalytic alternative for peptide coupling. The catalysis is sufficiently robust to enable pentapeptide synthesis, constructing all four amide bond linkages in a catalytic fashion.

  14. Learning via Query Synthesis

    KAUST Repository

    Alabdulmohsin, Ibrahim Mansour

    2017-05-07

    Active learning is a subfield of machine learning that has been successfully used in many applications. One of the main branches of active learning is query synthe- sis, where the learning agent constructs artificial queries from scratch in order to reveal sensitive information about the underlying decision boundary. It has found applications in areas, such as adversarial reverse engineering, automated science, and computational chemistry. Nevertheless, the existing literature on membership query synthesis has, generally, focused on finite concept classes or toy problems, with a limited extension to real-world applications. In this thesis, I develop two spectral algorithms for learning halfspaces via query synthesis. The first algorithm is a maximum-determinant convex optimization method while the second algorithm is a Markovian method that relies on Khachiyan’s classical update formulas for solving linear programs. The general theme of these methods is to construct an ellipsoidal approximation of the version space and to synthesize queries, afterward, via spectral decomposition. Moreover, I also describe how these algorithms can be extended to other settings as well, such as pool-based active learning. Having demonstrated that halfspaces can be learned quite efficiently via query synthesis, the second part of this thesis proposes strategies for mitigating the risk of reverse engineering in adversarial environments. One approach that can be used to render query synthesis algorithms ineffective is to implement a randomized response. In this thesis, I propose a semidefinite program (SDP) for learning a distribution of classifiers, subject to the constraint that any individual classifier picked at random from this distributions provides reliable predictions with a high probability. This algorithm is, then, justified both theoretically and empirically. A second approach is to use a non-parametric classification method, such as similarity-based classification. In this

  15. Synthesis of deuterated clenbuterol

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Ole [Risoe National Lab., Roskilde (Denmark). Solid State Physics Dept.; Egsgaard, Helge; Larsen, Elfinn [Risoe National Lab., Roskilde (Denmark). Science and Technology Dept.

    1996-11-01

    The synthesis of D{sub 9}-clenbuterol (I) and D{sub 3}-clenbuterol (II) is described. D{sub 9}-clenbuterol (I) was prepared from 4-amino-{alpha}-bromo-3, 5-dichloroacetophenone by reaction with D{sub 9}-tert-butylamine followed by reduction of the keto group with NaBH{sub 4}. D{sub 3}-clenbuterol (II) was prepared from 4-amino-{alpha}-tert-butylamino-3, 5-dichloroacetophenone by an exchange reaction of the {alpha}-hydrogens with deuterium followed by reduction of the keto group with NaBD{sub 4}. The eventual products were characterized by mass spectrometry and NMR. (author).

  16. Synthesis in land change science

    DEFF Research Database (Denmark)

    Magliocca, Nicholas R.; Rudel, Thomas K.; Verburg, Peter H.

    2015-01-01

    of these changes, land change science (LCS) draws on a wide array synthetic and meta-study techniques to generate global and regional knowledge from local case studies of land change. Here, we review the characteristics and applications of synthesis methods in LCS and assess the current state of synthetic research...... based on a meta-analysis of synthesis studies from 1995 to 2012. Publication of synthesis research is accelerating, with a clear trend toward increasingly sophisticated and quantitative methods, including meta-analysis. Detailed trends in synthesis objectives, methods, and land change phenomena......, synthesis methods based on local case studies will remain essential for generating systematic global and regional understanding of local land change for the foreseeable future, and multiple opportunities exist to accelerate and enhance the reliability of synthetic LCS research in the future. Demand...

  17. Reevaluating synthesis by biology.

    Science.gov (United States)

    Yadav, Vikramaditya G; Stephanopoulos, Gregory

    2010-06-01

    The two cornerstones of synthetic biology are the introduction of the new technology of chemical DNA synthesis and its subsequent emphasis on the use of standardized biological parts in the construction of genetic systems aimed at eliciting of desired cellular behavior. A number of high-impact applications have been proposed for this technology, notable among them being the biological synthesis of valuable compounds for chemical or pharmaceutical use. To this end, synthetic biologists propose assembling metabolic pathways in toto by combining genes isolated from a variety of sources. While pathway construction is similar to approaches established long ago by Metabolic Engineering, the two methods deviate significantly when it comes to pathway optimization. Synthetic biologists opt for gene-combinatorial methods whereby large numbers of pathways, comprising several combinations of genes from different sources, and their mutants, are evaluated in search for an optimal pathway configuration. Metabolic engineering, on the contrary, aims to optimize pathways by tuning the activity of the intermediate reaction steps. Both, rational methods based on kinetics and regulation, as well as combinatorial methods, typically in this order, are used to this end. We argue that a systematic approach consisting of fine-tuning the properties of individual pathway components, prominently enzymes, is a superior strategy to searches spanning large genetic spaces in engineering optimal microbes for the production of chemical and pharmaceutical products. Copyright 2010 Elsevier Ltd. All rights reserved.

  18. Synthesis of Lysophospholipids

    Directory of Open Access Journals (Sweden)

    Paola D’Arrigo

    2010-03-01

    Full Text Available New synthetic methods for the preparation of biologically active phospholipids and lysophospholipids (LPLs are very important in solving problems of membrane–chemistry and biochemistry. Traditionally considered just as second-messenger molecules regulating intracellular signalling pathways, LPLs have recently shown to be involved in many physiological and pathological processes such as inflammation, reproduction, angiogenesis, tumorogenesis, atherosclerosis and nervous system regulation. Elucidation of the mechanistic details involved in the enzymological, cell-biological and membrane-biophysical roles of LPLs relies obviously on the availability of structurally diverse compounds. A variety of chemical and enzymatic routes have been reported in the literature for the synthesis of LPLs: the enzymatic transformation of natural glycerophospholipids (GPLs using regiospecific enzymes such as phospholipases A1 (PLA1, A2 (PLA2 phospholipase D (PLD and different lipases, the coupling of enzymatic processes with chemical transformations, the complete chemical synthesis of LPLs starting from glycerol or derivatives. In this review, chemo-enzymatic procedures leading to 1- and 2-LPLs will be described.

  19. Oxygenates vs. synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  20. Synthesis of 2-phosphaadamantane derivatives

    International Nuclear Information System (INIS)

    Zemlyanoi, V.N.; Aleksandrov, A.M.; Kukhar', V.P.

    1986-01-01

    The authors describe the synthesis and properties of 2-phosphadamantane derivatives. For the synthesis of 2-phosphaadamantane derivatives they decided to use the methodology of the synthesis of 2-thiaadamantane. The IR spectra were determined on CHCl 3 solutions with a Specord 711R spectrometer, the PMR spectra were determined on Tesla BS-467 (60 MHz) and Bruker WP-200 (200 MHz) spectrometers, external standard hexamethyldisiloxane, the 31 P NMR spectra were determined on Tesla BS-487 C (30 MHz) and Bruker WP-200 (81 MHz) spectrometers, external standard 85% phosphoric acid, and the mass spectra were determined on an MS-1302 spectrometer

  1. Synthesis of C-vinylpyrroles

    International Nuclear Information System (INIS)

    Sobenina, Lyubov N; Demenev, Andrei P; Mikhaleva, Albina I; Trofimov, Boris A

    2002-01-01

    The latest advances in the synthesis of C-vinylpyrroles are generalised and systematised. Methods for the synthesis based on reactions of acylpyrroles and dicarbonyl compounds or their synthetic equivalents are still of most importance. New promising methods for the synthesis of C-vinylpyrroles are considered, among them the reactions of alkenyl ketone oximes with acetylene in the KOH-DMSO system and base-catalysed condensation of pyrrolecarbodithioates, which have recently become available, with CH-acids. The bibliography includes 195 references.

  2. Hypericin: chemical synthesis and biosynthesis.

    Science.gov (United States)

    Huang, Lin-Fang; Wang, Zeng-Hui; Chen, Shi-Lin

    2014-02-01

    Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of this unique compound. However, the synthetic strategies are challenging for organic and biological chemists. In this review, specific significant advances in total synthesis, semi-synthesis, and biosynthesis in the past decades are summarized. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  3. Synthesis of radium silicate

    International Nuclear Information System (INIS)

    Garibov, A.A; Agayev, T.N; Mansimov, Z.A

    2010-01-01

    Full text :One of the possible ways of implementation of the processes of molecular hydrogen radiologic of the elements in the differential heat of water as a catalyst for the collapse of the creation of a special nuclear reactors. A chemical process in radiation-4-oxide-silicon compounds, which is one of the radium, is of great importance. Research in the silicon-oxide-radiumun different activity-4 has been synthesized. As initial substances for the synthesis of tetra etiolate silicate and radium chloride solutions were used. At the same time to remove reaction products from the reaction intermediate in acetate acid was used. The intermediate product was reacted with ethyl alcohol ethyl acetate ether acetate acid that forms from the reaction of the temperature effect is broken. As a result, 4-oxide was initially pure silicon.

  4. The synthesis of clopidogrel

    Science.gov (United States)

    Huang, Yuanjun; Zhu, Qingxin

    2017-12-01

    Cardiac and cerebrovascular disease is a common disease. It is well recognized that antiplatelet agent is effective in the prevention and treatment of thrombosis. Clopidogrel is one of thieno pyridine derivatives, which can inhibit ADP-induced platelet aggregation. The preparation methods of Clopidogrel were reviewed and Clopidogrel was finally synthesized from 2-chlorobenzyl cyanide via bromination, condensation, hydrolyze, esterification, resolution, Finally with the sulfate, re-crystallization product of the target compound clopidogrel. The overall yield is 16%. Synthesis of the intermediate product and finally the structure of the product through ESI and 1H-NMR corroboration. The improved synthetic procedure has the advantage of low cost and is suitable for industrial production.

  5. Synthesis of cyclododeciptycene quinones.

    Science.gov (United States)

    Lou, Kaiyan; Prior, Allan M; Wiredu, Bernard; Desper, John; Hua, Duy H

    2010-12-15

    Cycloiptycenes are elusive and synthetically challenging molecules. We report the first synthesis of two substituted cyclododeciptycene tetraquinones via a sequence of intermolecular and intramolecular Diels-Alder reactions from cis,cis-heptiptycene tetraquinone 2 and substituted 7,16-dihydro-7,16-(o-benzeno)heptacenes 3. Heptiptycene tetraquinone 2 was made from triptycene bisquinone 4 and 1,4-dimethoxyanthracene in three steps, and 6,8,15,17-tetramethoxy-7,16-dihydro-7,16-(o-benzeno)heptacene (3a) was synthesized from triptycene bisquinone 4 and 1,4-dihydro-2,3-benzoxathiin-3-oxide in four steps. The structure of a cyclododeciptycene, 1a, was determined by a single-crystal X-ray analysis. The synthetic sequence is general and should allow the incorporation of various alkoxy and acetoxy substituents appended to the cycloiptycene framework.

  6. De Novo Glutamine Synthesis

    Science.gov (United States)

    He, Qiao; Shi, Xinchong; Zhang, Linqi; Yi, Chang; Zhang, Xuezhen

    2016-01-01

    Purpose: The aim of this study was to investigate the role of de novo glutamine (Gln) synthesis in the proliferation of C6 glioma cells and its detection with 13N-ammonia. Methods: Chronic Gln-deprived C6 glioma (0.06C6) cells were established. The proliferation rates of C6 and 0.06C6 cells were measured under the conditions of Gln deprivation along with or without the addition of ammonia or glutamine synthetase (GS) inhibitor. 13N-ammonia uptake was assessed in C6 cells by gamma counting and in rats with C6 and 0.06C6 xenografts by micro–positron emission tomography (PET) scanning. The expression of GS in C6 cells and xenografts was assessed by Western blotting and immunohistochemistry, respectively. Results: The Gln-deprived C6 cells showed decreased proliferation ability but had a significant increase in GS expression. Furthermore, we found that low concentration of ammonia was sufficient to maintain the proliferation of Gln-deprived C6 cells, and 13N-ammonia uptake in C6 cells showed Gln-dependent decrease, whereas inhibition of GS markedly reduced the proliferation of C6 cells as well as the uptake of 13N-ammoina. Additionally, microPET/computed tomography exhibited that subcutaneous 0.06C6 xenografts had higher 13N-ammonia uptake and GS expression in contrast to C6 xenografts. Conclusion: De novo Gln synthesis through ammonia–glutamate reaction plays an important role in the proliferation of C6 cells. 13N-ammonia can be a potential metabolic PET tracer for Gln-dependent tumors. PMID:27118759

  7. Vanillin Synthesis from 4-Hydroxybenzaldehyde

    Science.gov (United States)

    Taber, Douglass F.; Patel, Shweta; Hambleton, Travis M.; Winkel, Emma E.

    2007-01-01

    A regioselective, safe and efficient method for the synthesis of vanillin from 4-hydroxybenzaldehyde is being described. The vanillin derived from the process is cheap and can be used as a flavor or in the paper industry.

  8. Methyltrioctylammonium chloride catalysed sonochemical synthesis ...

    Indian Academy of Sciences (India)

    The greener, clean and efficient protocol for the synthesis of acridine diones derivatives has been achieved by reacting aromatic aldehyde, dimedone and amines using methyltrioctylammonium chloride (Aliquate 336) as a catalyst under ultrasonic irradiations.

  9. Green chemistry for nanoparticle synthesis.

    Science.gov (United States)

    Duan, Haohong; Wang, Dingsheng; Li, Yadong

    2015-08-21

    The application of the twelve principles of green chemistry in nanoparticle synthesis is a relatively new emerging issue concerning the sustainability. This field has received great attention in recent years due to its capability to design alternative, safer, energy efficient, and less toxic routes towards synthesis. These routes have been associated with the rational utilization of various substances in the nanoparticle preparations and synthetic methods, which have been broadly discussed in this tutorial review. This article is not meant to provide an exhaustive overview of green synthesis of nanoparticles, but to present several pivotal aspects of synthesis with environmental concerns, involving the selection and evaluation of nontoxic capping and reducing agents, the choice of innocuous solvents and the development of energy-efficient synthetic methods.

  10. Enzymatic synthesis of organophosphorus compounds

    International Nuclear Information System (INIS)

    Kolodiazhnyi, Oleg I

    2011-01-01

    Data on biocatalytic methods for the preparation of chiral organophosphorus compounds are generalized and described systematically. Various examples of enzymatic and microbiological synthesis of hydroxyphosphonates, aminophosphonates, phosphinites, phosphine oxides and tertiary phosphines are discussed. The bibliography includes 154 references.

  11. CLEAN CHEMICAL SYNTHESIS IN WATER

    Science.gov (United States)

    Newer green chemistry approach to accomplish chemical synthesis in water is summarized. Recent global developments pertaining to C-C bond forming reactions using metallic reagents and direct use of the renewable materials such as carbohydrates without derivatization are described...

  12. Gestural Control Of Wavefield synthesis

    DEFF Research Database (Denmark)

    Grani, Francesco; Di Carlo, Diego; Portillo, Jorge Madrid

    2016-01-01

    We present a report covering our preliminary research on the control of spatial sound sources in wavefield synthesis through gesture based interfaces. After a short general introduction on spatial sound and few basic concepts on wavefield synthesis, we presents a graphical application called sp......AAce which let users to con- trol real-time movements of sound sources by drawing tra- jectories on a screen. The first prototype of this application has been developed bound to WFSCollider, an open-source software based on Supercollider which let users control wavefield synthesis. The spAAce application has...... Wi- iMote game controller to “throw” sounding objects towards them. Aim of this project was to create a gestural interface for a game based on auditory cues only, and to investigate how convolution reverberation can affects people’s percep- tion of distance in a wavefield synthesis setup environment....

  13. Enzymatic synthesis of organophosphorus compounds

    Science.gov (United States)

    Kolodiazhnyi, Oleg I.

    2011-09-01

    Data on biocatalytic methods for the preparation of chiral organophosphorus compounds are generalized and described systematically. Various examples of enzymatic and microbiological synthesis of hydroxyphosphonates, aminophosphonates, phosphinites, phosphine oxides and tertiary phosphines are discussed. The bibliography includes 154 references.

  14. Essentials of inorganic materials synthesis

    CERN Document Server

    Rao, C N R

    2015-01-01

    This compact handbook describes all the important methods of synthesis employed today for synthesizing inorganic materials. Some features: Focuses on modern inorganic materials with applications in nanotechnology, energy materials, and sustainability Synthesis is a crucial component of materials science and technology; this book provides a simple introduction as well as an updated description of methods Written in a very simple style, providing references to the literature to get details of the methods of preparation when required

  15. Levulinic acid in organic synthesis

    International Nuclear Information System (INIS)

    Timokhin, Boris V; Baransky, V A; Eliseeva, G D

    1999-01-01

    Data concerning the methods of synthesis, chemical transformations and application of levulinic acid are analysed and generalised. The wide synthetic potential of levulinic acid, particularly as a key compound in the synthesis of various heterocyclic systems, saturated and unsaturated ketones and diketones, difficultly accessible acids and other compounds is demonstrated. The accessibility of levulinic acid from hexose-containing wood-processing and agricultural wastes is noted. The bibliography includes 260 references.

  16. Diamond Synthesis Employing Nanoparticle Seeds

    Science.gov (United States)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  17. Principles of digital image synthesis

    CERN Document Server

    Glassner, Andrew S

    1995-01-01

    Image synthesis, or rendering, is a field of transformation: it changesgeometry and physics into meaningful images. Because the most popularalgorithms frequently change, it is increasingly important for researchersand implementors to have a basic understanding of the principles of imagesynthesis. Focusing on theory, Andrew Glassner provides a comprehensiveexplanation of the three core fields of study that come together to formdigital image synthesis: the human visual system, digital signalprocessing, and the interaction of matter and light. Assuming no more thana basic background in calculus,

  18. Isolation and synthesis of curcumin

    OpenAIRE

    Zetterström, Susanna

    2012-01-01

    The aim of this thesis was to evaluate pre-existing methods for isolation and synthesis of curcumin. Two different isolation methods were used, where only the extraction step differs from each other. To obtain pure curcumin, column chromatography was needed to separate the compound from its analogues. As for the isolation the synthesis was also carried out by two different methods, the first in a conventional way and the second one by using irradiation of microwaves. The result of the experim...

  19. Synthesis of ferroelectric nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Roervik, Per Martin

    2008-12-15

    The increasing miniaturization of electric and mechanical components makes the synthesis and assembly of nanoscale structures an important step in modern technology. Functional materials, such as the ferroelectric perovskites, are vital to the integration and utility value of nanotechnology in the future. In the present work, chemical methods to synthesize one-dimensional (1D) nanostructures of ferroelectric perovskites have been studied. To successfully and controllably make 1D nanostructures by chemical methods it is very important to understand the growth mechanism of these nanostructures, in order to design the structures for use in various applications. For the integration of 1D nanostructures into devices it is also very important to be able to make arrays and large-area designed structures from the building blocks that single nanostructures constitute. As functional materials, it is of course also vital to study the properties of the nanostructures. The characterization of properties of single nanostructures is challenging, but essential to the use of such structures. The aim of this work has been to synthesize high quality single-crystalline 1D nanostructures of ferroelectric perovskites with emphasis on PbTiO3 , to make arrays or hierarchical nanostructures of 1D nanostructures on substrates, to understand the growth mechanisms of the 1D nanostructures, and to investigate the ferroelectric and piezoelectric properties of the 1D nanostructures. In Paper I, a molten salt synthesis route, previously reported to yield BaTiO3 , PbTiO3 and Na2Ti6O13 nanorods, was re-examined in order to elucidate the role of volatile chlorides. A precursor mixture containing barium (or lead) and titanium was annealed in the presence of NaCl at 760 degrees Celsius or 820 degrees Celsius. The main products were respectively isometric nanocrystalline BaTiO3 and PbTiO3. Nanorods were also detected, but electron diffraction revealed that the composition of the nanorods was

  20. Synthesis of nanostructured polyaniline

    Science.gov (United States)

    Surwade, Sumedh P.

    The organization of my thesis is as follows: (a) Chapter III describes the synthesis of bulk quantities of polyaniline nanofibers in one step using a simple and versatile high ionic strength aqueous system (HCl/NaCl) that permits the use of pure H2O2 as a mild oxidant without any added metal or enzyme catalyst. Polyaniline nanofibers obtained are highly conducting, sigma˜1--5 S/cm, and spectroscopically similar to conventional polyaniline synthesized using stronger oxidants. The synthesis method is further extended to the synthesis of oligoanilines of controlled molecular weight, e.g., aniline tetramer, octamer, and hexadecamer. Microns long tetramer nanofibers are synthesized using this method. (b) Chapter IV describes the mechanism of nanofiber formation in polyaniline. It is proposed that the surfaces such as the walls of the reaction vessel and/or intentionally added surfaces play a dramatic role in the evolution of nanofibrillar morphology. Nucleation sites on surfaces promote the accumulation of aniline dimer that reacts further to yield aniline tetramer, which (surprisingly) is entirely in form of nanofibers and whose morphology is transcribed to the bulk by a double heterogeneous nucleation mechanism. This unexpected phenomenon could form the basis of nanofiber formation in all classes of precipitation polymerization systems. (c) Chapter V is the mechanistic study on the formation of oligoanilines during the chemical oxidation of aniline in weakly acidic, neutral or basic media using peroxydisulfate oxidant. It is proposed that the reaction proceeds via the intermediacy of benzoquinone monoimine that is formed as a result of a Boyland-Sims rearrangement of aniline. The initial role of peroxydisulfate is to provide a pathway for the formation of benzoquinone monoimine intermediate that is followed by a conjugate Michael-type addition reaction with aniline or sulfated anilines. The products isolated in pH 2.5--10.0 buffers are intermediate species at various

  1. Electrifying Organic Synthesis.

    Science.gov (United States)

    Wiebe, Anton; Gieshoff, Tile; Möhle, Sabine; Rodrigo, Eduardo; Zirbes, Michael; Waldvogel, Siegfried R

    2018-01-02

    The direct synthetic organic use of electricity is currently experiencing a renaissance. More synthetically oriented laboratories working in this area are exploiting both novel and more traditional concepts, paving the way to broader applications of this niche technology. As only electrons serve as reagents, the generation of reagent waste is efficiently avoided. Moreover, stoichiometric reagents can be regenerated and allow a transformation to be conducted in an electrocatalytic fashion. However, the application of electroorganic transformations is more than minimizing the waste footprint, it rather gives rise to inherently safe processes, reduces the number of steps of many syntheses, allows for milder reaction conditions, provides alternative means to access desired structural entities, and creates intellectual property (IP) space. When the electricity originates from renewable resources, this surplus might be directly employed as a terminal oxidizing or reducing agent, providing an ultra-sustainable and therefore highly attractive technique. This Review surveys recent developments in electrochemical synthesis that will influence the future of this area. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  2. Synthesis of P005091

    Directory of Open Access Journals (Sweden)

    Ping YU

    2016-06-01

    Full Text Available To improve the synthesis method of P005091 (1-(5-((2,3-dichlorophenyl thio-4-nitro-2-thienyl ethanone, with 2-chlorothiophene as the starting material, acetyl chloride as the acetylation reagent and aluminium trichloride as the catalyst, acetyl is introduced in the 5th position of 2-chlorothiophene to get 2-acetyl-5-chlorothiophene (compound 2, and the yield is 91%; then with concentrated sulfuric acid as solvent and mixed acid as nitrating agent, 5-acetyl-2-chloro-3-nitrothiophene (compound 3 is obtained by nitration reaction with compound 2, and the yield is 64%; thioetherfication reaction of compound 3 and 2,3-dichlorobenzenethiol in DMF solution under the function of potassium carbonate takes place to obtain the target product P005091, and the yield is 76%. The structure of P005091 is confirmed by mp, 1H-NMR, 13C-NMR and MS, and the overall yield is 44%. The improved method has the advantages of low cost, simple operation, and a milder reaction condition compared with the former references, avoiding using the reagent with higher toxicity, and high yield on the premise that the product purity is assured.

  3. Synthesis of ammonia using sodium melt

    OpenAIRE

    Kawamura, Fumio; Taniguchi, Takashi

    2017-01-01

    Research into inexpensive ammonia synthesis has increased recently because ammonia can be used as a hydrogen carrier or as a next generation fuel which does not emit CO2. Furthermore, improving the efficiency of ammonia synthesis is necessary, because current synthesis methods emit significant amounts of CO2. To achieve these goals, catalysts that can effectively reduce the synthesis temperature and pressure, relative to those required in the Haber-Bosch process, are required. Although severa...

  4. Sustainable Process Synthesis-Intensification

    DEFF Research Database (Denmark)

    Babi, Deenesh Kavi; Holtbruegge, Johannes; Lutze, Philip

    2014-01-01

    Sustainable process design can be achieved by performing process synthesis and process intensification together. This approach first defines a design target through a sustainability analysis and then finds design alternatives that match the target through process intensification. A systematic......, multi-stage framework for process synthesis- intensification that identifies more sustainable process designs has been developed. At stages 1-2, the working scale is at the level of unit operations, where a base case design is identified and analyzed with respect to sustainability metrics. At stages 3......, a phenomena-based process synthesis method is applied, where the phenomena involved in each tasks are identified, manipulated and recombined to generate new and/or existing unit operations configured into flowsheets that are more sustainable from those found in the previous levels. An overview of the key...

  5. Synthesis through Trans-disciplinarity

    DEFF Research Database (Denmark)

    Hansen, Hanne Tine Ring

    2006-01-01

    , architecture and landscape provides a great architectural experience. Another is Jörn Utzon's church in Bagsvaerd, Denmark, where the treatment of construction, acoustics and daylight ingeniously fuses with the church's function and architectural expression, once again offering a unique architectural...... experience. In relation to ‘environmentally sustainable' architecture the importance of synthesis becomes even more apparent, however, as the success of the design depends on how, and if, a synthesis is achieved between technology and architectural design.[2] This understanding has led me to consider how...... synthesis is a requirement for creating successful ‘environmentally sustainable' architecture through the application of trans-disciplinarity, which leads to an increased awareness of the differences in decision-making as well as that of communication barriers between the different professions...

  6. Sustainable Process Synthesis-Intensification

    DEFF Research Database (Denmark)

    Babi, Deenesh Kavi; Holtbruegge, Johannes; Lutze, Philip

    2014-01-01

    Sustainable process design can be achieved by performing process synthesis and process intensification together. This approach first defines a design target through a sustainability analysis and then finds design alternatives that match the target through process intensification. A systematic, mu...... concepts and the framework are presented together with the results from a case study highlighting the application of the framework to the sustainable design of a production process for dimethyl carbonate.......Sustainable process design can be achieved by performing process synthesis and process intensification together. This approach first defines a design target through a sustainability analysis and then finds design alternatives that match the target through process intensification. A systematic......, multi-stage framework for process synthesis- intensification that identifies more sustainable process designs has been developed. At stages 1-2, the working scale is at the level of unit operations, where a base case design is identified and analyzed with respect to sustainability metrics. At stages 3...

  7. The KTH synthesis of singing

    Directory of Open Access Journals (Sweden)

    Johan Sundberg

    2006-01-01

    Full Text Available This is an overview of the work with synthesizing singing that has been carried out at the Speech Music Hearing Department, KTH since 1977. The origin of the work, a hardware synthesis machine, is described and some aspects of the control program, a modified version of a text-to-speech conversion system are reviewed. Three applications are described in which the synthesis system has paved the way for investigations of specific aspects of the singing voice. One concerns the perceptual relevance of the center frequency of the singer's formant, one deals with characteristics of an ugly voice, and one regards intonation. The article is accompanied by 18 sound examples, several of which were not published before. Finally, limitations and advantages of singing synthesis are discussed.

  8. Structural synthesis of parallel robots

    CERN Document Server

    Gogu, Grigore

    This book represents the fifth part of a larger work dedicated to the structural synthesis of parallel robots. The originality of this work resides in the fact that it combines new formulae for mobility, connectivity, redundancy and overconstraints with evolutionary morphology in a unified structural synthesis approach that yields interesting and innovative solutions for parallel robotic manipulators.  This is the first book on robotics that presents solutions for coupled, decoupled, uncoupled, fully-isotropic and maximally regular robotic manipulators with Schönflies motions systematically generated by using the structural synthesis approach proposed in Part 1.  Overconstrained non-redundant/overactuated/redundantly actuated solutions with simple/complex limbs are proposed. Many solutions are presented here for the first time in the literature. The author had to make a difficult and challenging choice between protecting these solutions through patents and releasing them directly into the public domain. T...

  9. Woodward's Synthesis of Vitamin B12

    Indian Academy of Sciences (India)

    The synthesis of this molecule was a landmark in organic synthesis. It involved the masterful control of shapes of molecules to create 9 chiral centres with known absolute and relative configurations. The concepts of absolute and induced asymmetric synthesis are here explained. Robert B. Woodward was one of the greatest ...

  10. STICS: surface-tethered iterative carbohydrate synthesis.

    Science.gov (United States)

    Pornsuriyasak, Papapida; Ranade, Sneha C; Li, Aixiao; Parlato, M Cristina; Sims, Charles R; Shulga, Olga V; Stine, Keith J; Demchenko, Alexei V

    2009-04-14

    A new surface-tethered iterative carbohydrate synthesis (STICS) technology is presented in which a surface functionalized 'stick' made of chemically stable high surface area porous gold allows one to perform cost efficient and simple synthesis of oligosaccharide chains; at the end of the synthesis, the oligosaccharide can be cleaved off and the stick reused for subsequent syntheses.

  11. Formal synthesis of naturally occurring norephedrine

    Indian Academy of Sciences (India)

    A concise and simple synthesis of 1-hydroxy-phenethylamine derivatives has been achieved following classical organic transformations using commercially available chiral pools. The said derivatives were explored for the synthesis of naturally occurring bio-active small molecules. Formal synthesis of norephedrine, virolin ...

  12. Ferroic materials synthesis and applications

    CERN Document Server

    Virk, Hardev Singh

    2015-01-01

    Ferroics is the generic name given to the study of ferromagnets, ferroelectrics, and ferroelastics. The basis of this study is to understand the large changes in physical characteristics that occur over a very narrow temperature range. In recent years, a new class of ferroic materials has been attracting increased interest. These multiferroics exhibit more than one ferroic property simultaneously in a single phase. The present volume: ""Ferroic Materials: Synthesis and Applications"" has ten Chapters, spread over areas as diverse as Magnetic Oxide Nanomaterials, Ferrites Synthesis, Hexaferrite

  13. Impaired glutathione synthesis in schizophrenia

    DEFF Research Database (Denmark)

    Gysin, René; Kraftsik, Rudolf; Sandell, Julie

    2007-01-01

    Schizophrenia is a complex multifactorial brain disorder with a genetic component. Convergent evidence has implicated oxidative stress and glutathione (GSH) deficits in the pathogenesis of this disease. The aim of the present study was to test whether schizophrenia is associated with a deficit...... of GSH synthesis. Cultured skin fibroblasts from schizophrenia patients and control subjects were challenged with oxidative stress, and parameters of the rate-limiting enzyme for the GSH synthesis, the glutamate cysteine ligase (GCL), were measured. Stressed cells of patients had a 26% (P = 0.......002) decreased GCL activity as compared with controls. This reduction correlated with a 29% (P schizophrenia in two...

  14. Sequential logic analysis and synthesis

    CERN Document Server

    Cavanagh, Joseph

    2007-01-01

    Until now, there was no single resource for actual digital system design. Using both basic and advanced concepts, Sequential Logic: Analysis and Synthesis offers a thorough exposition of the analysis and synthesis of both synchronous and asynchronous sequential machines. With 25 years of experience in designing computing equipment, the author stresses the practical design of state machines. He clearly delineates each step of the structured and rigorous design principles that can be applied to practical applications. The book begins by reviewing the analysis of combinatorial logic and Boolean a

  15. Tunable synthesis of copper nanotubes

    International Nuclear Information System (INIS)

    Kaniukov, E; Yakimchuk, D; Kozlovsky, A; Shlimas, D; Zdorovets, M; Kadyrzhanov, K

    2016-01-01

    Simple method of tunable synthesis of copper nanotubes based on template synthesis was developed. A comprehensive study of the structural, morphological and electrical characteristics of the obtained nanostructures was carried out. Characterization of structural features was made by methods of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry analysis. Evaluation of wall thickness is made by methods of gas permeability. Electrical conductivity of nanotubes was define in the study of their current-voltage characteristics. The possibility to control of copper nanotubes physical properties by variation of the deposition parameters was shown. (paper)

  16. A Short Synthesis of (+)-Cyclophellitol

    DEFF Research Database (Denmark)

    Hansen, Flemming Gundorph; Bundgaard, Eva; Madsen, Robert

    2005-01-01

    A new synthesis of (+)-cyclophellitol, a potent b-glucosidase inhibitor, has been completed in nine steps from D-xylose. The key transformations involve a zinc-mediated fragmentation of benzyl-protected methyl 5-deoxy-5-iodo-xylofuranoside followed by a highly diastereoselective indium-mediated c......-mediated coupling with ethyl 4-bromocrotonate. Subsequent ring-closing olefin metathesis, ester reduction, olefin epoxidation, and deprotection then afford the natural product. This constitutes the shortest synthesis of (+)-cyclophellitol reported to date....

  17. Synthesis of magnetic polymeric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2010-05-13

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  18. Synthesis of magnetic polymeric microspheres

    International Nuclear Information System (INIS)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I

    2010-01-01

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  19. β-Enaminonitriles in heterocylic synthesis: Synthesis of new ...

    Indian Academy of Sciences (India)

    WINTEC

    gicides and solvatochromatic dyes. Recently, a num- ber of papers and patents concerning the importance of β-enaminonitriles in the synthesis of biologically active compounds, dihydropyridines analogous to nifedipine and amlodipine as potential calcium channel blockers in the treatment of angina and hypertension have ...

  20. The Effect of Synthesis Parameters on the Catalytic Synthesis of ...

    African Journals Online (AJOL)

    NJD

    Synthesis of Multiwalled Carbon Nanotubes using. Fe-Co/CaCO. 3. Catalysts. Sabelo D. Mhlangaa,b, Kartick C. Mondala,b, Robin Cartera,b, Michael J. Witcombb,c and Neil J. Covillea,b*. aMolecular Sciences Institute and School of Chemistry, University of the Witwatersrand, Johannesburg, WITS 2050, South Africa.

  1. Plant mediated green synthesis: modified approaches

    Science.gov (United States)

    Das, Ratul Kumar; Brar, Satinder Kaur

    2013-10-01

    Plant mediated green synthesis of different metallic nanoparticles has emerged as one of the options for implementation of green chemistry principles, and successfully made an important contribution towards green nanotechnology. However, beyond the synthesis and application aspects, the science of green synthesis has carried some wrong perceptions in an unforeseen fashion. In this review, some of the key issues related to the green synthesis of metallic nanoparticles employing plants as reducing/capping agents have been addressed. Random selection of plants and its overall impact on the different aspects of green synthesis have been discussed. Emphasis is given to the setting of some standard selection criteria to be adopted for selecting a plant for use in green synthesis. How selection of a plant can positively or negatively influence both procedure and products of a green synthesis process is the prime concern of this article. In addition to selection, the key issue of biocompatibility associated with green synthesized metallic nanoparticles has been considered. Both selection of plant and biocompatibility were reconsidered for their minute details in terms of synthesis, analysis and data interpretation in the green synthesis approach. The key factors capable of fine tuning the core meaning of ``green'' in the synthesis of any metallic nanoparticles were taken into consideration. This article is an effort towards keeping the core meaning of green synthesis.

  2. Plant mediated green synthesis: modified approaches.

    Science.gov (United States)

    Das, Ratul Kumar; Brar, Satinder Kaur

    2013-11-07

    Plant mediated green synthesis of different metallic nanoparticles has emerged as one of the options for implementation of green chemistry principles, and successfully made an important contribution towards green nanotechnology. However, beyond the synthesis and application aspects, the science of green synthesis has carried some wrong perceptions in an unforeseen fashion. In this review, some of the key issues related to the green synthesis of metallic nanoparticles employing plants as reducing/capping agents have been addressed. Random selection of plants and its overall impact on the different aspects of green synthesis have been discussed. Emphasis is given to the setting of some standard selection criteria to be adopted for selecting a plant for use in green synthesis. How selection of a plant can positively or negatively influence both procedure and products of a green synthesis process is the prime concern of this article. In addition to selection, the key issue of biocompatibility associated with green synthesized metallic nanoparticles has been considered. Both selection of plant and biocompatibility were reconsidered for their minute details in terms of synthesis, analysis and data interpretation in the green synthesis approach. The key factors capable of fine tuning the core meaning of "green" in the synthesis of any metallic nanoparticles were taken into consideration. This article is an effort towards keeping the core meaning of green synthesis.

  3. Green chemistry for chemical synthesis

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign. PMID:18768813

  4. Efficient synthesis of substituted dihydrotetraazapentacenes.

    Science.gov (United States)

    Seillan, Claire; Brisset, Hugues; Siri, Olivier

    2008-09-18

    We describe a versatile and very efficient synthesis of previously unknown substituted 5,14-dihydro-5,7,12,14-tetraazapentacenes (DHTAPs). A structural study by NMR spectroscopy showed that the conjugated pi-system of the pentacyclic skeleton rearranges depending on the electronic effect of the substituent(s).

  5. Analysis and synthesis of laughter

    Science.gov (United States)

    Sundaram, Shiva; Narayanan, Shrikanth

    2004-10-01

    There is much enthusiasm in the text-to-speech community for synthesis of emotional and natural speech. One idea being proposed is to include emotion dependent paralinguistic cues during synthesis to convey emotions effectively. This requires modeling and synthesis techniques of various cues for different emotions. Motivated by this, a technique to synthesize human laughter is proposed. Laughter is a complex mechanism of expression and has high variability in terms of types and usage in human-human communication. People have their own characteristic way of laughing. Laughter can be seen as a controlled/uncontrolled physiological process of a person resulting from an initial excitation in context. A parametric model based on damped simple harmonic motion to effectively capture these diversities and also maintain the individuals characteristics is developed here. Limited laughter/speech data from actual humans and synthesis ease are the constraints imposed on the accuracy of the model. Analysis techniques are also developed to determine the parameters of the model for a given individual or laughter type. Finally, the effectiveness of the model to capture the individual characteristics and naturalness compared to real human laughter has been analyzed. Through this the factors involved in individual human laughter and their importance can be better understood.

  6. Methyltrioctylammonium chloride catalysed sonochemical synthesis ...

    Indian Academy of Sciences (India)

    Methyltrioctylammonium chloride catalysed sonochemical synthesis of acridine diones. BHUPINDER KAUR and HARISH KUMAR. ∗. Department of Chemistry, Sant Longowal Institute of Engineering and Technology, Longowal 148 106, India e-mail: choprahk67@gmail.com. MS received 21 May 2012; revised 30 January ...

  7. SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL ...

    African Journals Online (AJOL)

    Preferred Customer

    KEY WORDS: Monoacyl aniline, Synthesis, Density functional theory, Rotation barrier. INTRODUCTION ... on the electron density in the phenyl ring and the respective accelerating and decelerating effects on the rate of ... compounds were determined using Nujol mulls and of liquids either in dichloromethane or chloroform ...

  8. Hydrothermal synthesis, characterization and luminescent ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF 4 nanoparticles. JIGMET LADOL HEENA KHAJURIA SONIKA KHAJURIA ... Keywords. Citric acid; X-ray diffraction; down-conversion emission; energy transfer.

  9. Methanol synthesis beyond chemical equilibrium

    NARCIS (Netherlands)

    van Bennekom, J. G.; Venderbosch, R. H.; Winkelman, J. G. M.; Wilbers, E.; Assink, D.; Lemmens, K. P. J.; Heeres, H. J.

    2013-01-01

    In commercial methanol production from syngas, the conversion is thermodynamically limited to 0.3-0.7 leading to large recycles of non-converted syngas. This problem can be overcome to a significant extent by in situ condensation of methanol during its synthesis which is possible nowadays due to the

  10. Total Synthesis of a Gene

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 12. Total Synthesis of a Gene. H G Khorana. Classics Volume 17 Issue 12 December 2012 pp 1174-1197 ... Author Affiliations. H G Khorana1. Professor of Biology and Chemestry, Massachusetts Institute of Technology, Cambridge 02139.

  11. Brassinosteroids: synthesis and biological activities

    Czech Academy of Sciences Publication Activity Database

    Oklešťková, Jana; Rárová, Lucie; Kvasnica, Miroslav; Strnad, Miroslav

    2015-01-01

    Roč. 14, č. 6 (2015), s. 1053-1072 ISSN 1568-7767 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Brassinosteroids * Chemical synthesis * Plant biological activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.686, year: 2015

  12. Synthesis of partially stabilized leucite

    Czech Academy of Sciences Publication Activity Database

    Kloužková, A.; Mrázová, M.; Kohoutková, Martina

    2007-01-01

    Roč. 68, 5-6 (2007), s. 1207-1210 ISSN 0022-3697 R&D Projects: GA MPO 2A-1TP1/063 Institutional research plan: CEZ:AV0Z40320502 Keywords : ceramics * chemical synthesis * X-ray diffraction Subject RIV: CA - Inorganic Chemistry Impact factor: 0.899, year: 2007

  13. Methyltrioctylammonium chloride catalysed sonochemical synthesis ...

    Indian Academy of Sciences (India)

    of the researchers because of their use as drugs for car- diovascular diseases, such as angina pectoris,7 hyper- tension,8 antitumour agents,9–11 DNA-binding moieties and DNA-intercalating anticancer drugs.12,13 There- fore, the synthesis of ... properties of ionic liquids they are emerging as a 'green reaction media'. ∗.

  14. Protein synthesis controls phosphate homeostasis.

    Science.gov (United States)

    Pontes, Mauricio H; Groisman, Eduardo A

    2018-01-01

    Phosphorus is an essential element assimilated largely as orthophosphate (Pi). Cells respond to Pi starvation by importing Pi from their surroundings. We now report that impaired protein synthesis alone triggers a Pi starvation response even when Pi is plentiful in the extracellular milieu. In the bacterium Salmonella enterica serovar Typhimurium , this response entails phosphorylation of the regulatory protein PhoB and transcription of PhoB-dependent Pi transporter genes and is eliminated upon stimulation of adenosine triphosphate (ATP) hydrolysis. When protein synthesis is impaired due to low cytoplasmic magnesium (Mg 2+ ), Salmonella triggers the Pi starvation response because ribosomes are destabilized, which reduces ATP consumption and thus free cytoplasmic Pi. This response is transient because low cytoplasmic Mg 2+ promotes an uptake in Mg 2+ and a decrease in ATP levels, which stabilizes ribosomes, resulting in ATP consumption and Pi increase, thus ending the response. Notably, pharmacological inhibition of protein synthesis also elicited a Pi starvation response in the bacterium Escherichia coli and the yeast Saccharomyces cerevisiae Our findings identify a regulatory connection between protein synthesis and Pi homeostasis that is widespread in nature. © 2018 Pontes and Groisman; Published by Cold Spring Harbor Laboratory Press.

  15. Phytochelatin synthesis in tomato cells

    International Nuclear Information System (INIS)

    Goldsbrough, P.; Gupta, S.; Huang, B.; Scheller, H.

    1987-01-01

    Tomato cells that are exposed to cadmium and other heavy metals synthesize phytochelatins (PCs), a family of peptides that bind heavy metals and are structurally related to glutathione (GSH). PCs have the structure (γ-glutamyl-cysteinyl) glycine; for PCs, n=2-10; GSH, n=1. GSH levels decline rapidly in tomato cells exposed to Cd 2+ . Buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, prevents sustained synthesis of PC. However the addition of GSH to the medium of BSO-treated cells restores PC production. In vivo labeling studies indicate that 35 [S]-cysteine is incorporated into PC via GSH, rather than being added directly to GSH or pre-formed PC. Initial synthesis of PCs is not inhibited by cycloheximide. Tomato cell cultures that are tolerant of high levels of Cd 2+ contain large amounts of PCs. However, when sensitive and tolerant cells that have been grown in the absence of Cd 2+ are exposed to relatively low concentrations of Cd 2+ , they synthesize PCs at similar rates. These and other results suggest that, although PCs are necessary, increased PC synthesis is not sufficient for expression of the Cd 2+ tolerant phenotype

  16. Synthesis of Glucose Spiropiperazinone Derivatives

    OpenAIRE

    Vasiļjevs, D

    2013-01-01

    Piperazinone derivatives аге noticeable peptidometics; therefore, they сап replace peptides, such as RGD and Leu-enkephalin in different biological processes. Some piperazinone derivatives are anticoagulants, others act like neurotransmitters. Herein, we report an approach for the synthesis of поуеl piperazinone ring containing spiro-derivatives of glucose.

  17. Catalysis and prebiotic RNA synthesis

    Science.gov (United States)

    Ferris, James P.

    1993-01-01

    The essential role of catalysis for the origins of life is discussed. The status of the prebiotic synthesis of 2',5'- and 3'5'-linked oligomers of RNA is reviewed. Examples of the role of metal ion and mineral catalysis in RNA oligomer formation are discussed.

  18. SYNTHESIS AND CHARACTERIZATION OF FUNCTIONALIZED ...

    African Journals Online (AJOL)

    2016-07-30

    E-mail: b_mohtat@yahoo.com. This work is licensed under the Creative Commons ... Department of Chemistry, Islamic Azad University, Karaj Branch, Karaj, Iran. (Received July 30, 2016; revised ..... Chem. 2013, 9, 2846-2851. 7. Mohamed, K.S.; Soliman, M.A.; El-Remaily, M.A.A.; Abdel-Ghany, H. Eco-friendly synthesis of ...

  19. Northwest Forest Plan research synthesis.

    Science.gov (United States)

    Richard W. Haynes; Gloria E. Perez; [tech. eds.].

    2000-01-01

    This document synthesizes research accomplishments initiated and funded under the Northwest Forest Plan or the President’s Forest Plan (hereafter referred to as the Forest Plan) since its inception in 1994. Three major parts in this document cover, the context for this effort, eight Forest Plan research accomplishments, and a synthesis. The eight accomplishments...

  20. Multicomponent reactions in polymer synthesis.

    Science.gov (United States)

    Kakuchi, Ryohei

    2014-01-03

    More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. IONOTHERMAL SYNTHESIS, STRUCTURES AND SUPRAMOLE

    African Journals Online (AJOL)

    Preferred Customer

    2Department of Chemistry, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal. (Received October 14 ... The principal feature of ionothermal synthesis is that the ionic liquids (ILs) act as both the “designed” green solvents ... purification except [EMI]Br. [EMI]Br was synthesized from the reaction of ethylbromide with.

  2. Green chemistry for chemical synthesis

    OpenAIRE

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  3. Green chemistry for chemical synthesis.

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M

    2008-09-09

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  4. Synthesis of [14C] alaproclate

    International Nuclear Information System (INIS)

    Gawell, Lars

    1986-01-01

    The synthesis of carbon-14 labelled alaproclate from [2- 14 C]acetone in three steps is described. The label is introduced by the reaction of a benzylic Grignard reagent with the ketone yielding a tertiary alcohol. Subsequent esterification with an α-bromocarboxylic acid chloride and amination produced the title compound in a 13% overall radiochemical yield. (author)

  5. The Total Synthesis of Chlorophyll

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 7. The Total Synthesis of Chlorophyll. Setty Mallikarjuna Babu Subramania Ranganathan. General Article Volume 19 Issue 7 July 2014 pp 645-648. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Organic Synthesis using Clay Catalysts

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 1. Organic Synthesis using Clay Catalysts - Clays for 'Green Chemistry'. Gopalpur Nagendrappa. General Article Volume 7 Issue 1 January 2002 pp 64-77. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Hydrothermal synthesis, characterization and luminescent ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF 4 nanoparticles. JIGMET LADOL HEENA KHAJURIA SONIKA KHAJURIA HAQ NAWAZ SHEIKH. Volume 39 Issue 4 August 2016 pp 943-952 ...

  8. The Total Synthesis of Strychnine

    Indian Academy of Sciences (India)

    IAS Admin

    The Total Synthesis of Strychnine. Edited by Setty Mallikarjuna Babu and Subramania Ranganathan. Keywords. Strychnine. N. N. O. H. H. H. H. O. H. Strychnine! No other molecule has captured the popular imagina- tion as strychnine, perhaps because thousands of writers of fiction have used it to dispatch the recipient and ...

  9. SYNTHESIS, STRUCTURE AND PHOTOLUMINESCENCE OF ...

    African Journals Online (AJOL)

    Preferred Customer

    dimensional supramolecular framework. ... The growing interest in the field of the crystal engineering of inorganic-organic hybrid materials .... Synthesis, structure and photoluminescence of (HgCl3)n(C6NO2H6)n(C6NO2H5)n nH2O. Bull. Chem.

  10. Haber Process for Ammonia Synthesis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Haber Process for Ammonia Synthesis. Jayant M Modak. Volume 16 Issue 12 December 2011 pp 1159-1167. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/016/12/1159-1167. Keywords.

  11. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  12. Microstructured Reactors for Electroorganic Synthesis

    Czech Academy of Sciences Publication Activity Database

    Bouzek, K.; Jiřičný, Vladimír; Kodým, R.; Křišťál, Jiří; Bystroň, T.

    2010-01-01

    Roč. 55, č. 7 (2010), s. 8172-8181 ISSN 0013-4686. [Annual Meeting of ISE /60./. Beijing, 16.08.2009-21.08.2009] Institutional research plan: CEZ:AV0Z40720504 Keywords : microstructured reactor * bipolar * electroorganic synthesis Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.642, year: 2010

  13. Smooth transition from sudden to adiabatic states in heavy-ion fusion reactions at deep-subbarrier incident energies

    International Nuclear Information System (INIS)

    Takatoshi, Ichikawa; Kouichi, Hagino; Akira, Iwamoto

    2011-01-01

    We propose a novel extension of the standard coupled-channel (CC) model in order to account for the steep falloff of fusion cross sections at deep-subbarrier incident energies. We introduce a damping factor in the coupling potential in the CC model, simulating smooth transitions from sudden to adiabatic states in deep- subbarrier fusion reactions. The CC model extended with the damping factor can reproduce well not only the steep falloff of the fusion cross section but also the saturation of the logarithmic derivatives for the fusion cross sections at deep-subbarrier energies for the 16 O+ 208 Pb, 64 Ni+ 64 Ni, and 58 Ni+ 58 Ni reactions at the deep-subbarrier energies. The important point in our model is that the transition takes place at different places for each Eigen channel. We conclude that the smooth transition from the two-body to the adiabatic one-body potential is responsible for the steep falloff of the fusion cross section

  14. Synthesis of Polycyclic Natural Products

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tuan Hoang [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    With the continuous advancements in molecular biology and modern medicine, organic synthesis has become vital to the support and extension of those discoveries. The isolations of new natural products allow for the understanding of their biological activities and therapeutic value. Organic synthesis is employed to aid in the determination of the relationship between structure and function of these natural products. The development of synthetic methodologies in the course of total syntheses is imperative for the expansion of this highly interdisciplinary field of science. In addition to the practical applications of total syntheses, the structural complexity of natural products represents a worthwhile challenge in itself. The pursuit of concise and efficient syntheses of complex molecules is both gratifying and enjoyable.

  15. Stereoselective Halogenation in Natural Product Synthesis.

    Science.gov (United States)

    Chung, Won-jin; Vanderwal, Christopher D

    2016-03-24

    At last count, nearly 5000 halogenated natural products have been discovered. In approximately half of these compounds, the carbon atom to which the halogen is bound is sp(3) -hybridized; therefore, there are an enormous number of natural products for which stereocontrolled halogenation must be a critical component of any synthesis strategy. In this Review, we critically discuss the methods and strategies used for stereoselective introduction of halogen atoms in the context of natural product synthesis. Using the successes of the past, we also attempt to identify gaps in our synthesis technology that would aid the synthesis of halogenated natural products, as well as existing methods that have not yet seen application in complex molecule synthesis. The chemistry described herein demonstrates yet again how natural products continue to provide the inspiration for critical advances in chemical synthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Physical synthesis of quantum circuits using templates

    Science.gov (United States)

    Mirkhani, Zahra; Mohammadzadeh, Naser

    2016-10-01

    Similar to traditional CMOS circuits, quantum circuit design flow is divided into two main processes: logic synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit metrics because of no information sharing between logic synthesis and physical design processes, the concept of " physical synthesis" was introduced for quantum circuit flow, and a few techniques were proposed for it. Following that concept, in this paper a new approach for physical synthesis inspired by template matching idea in quantum logic synthesis is proposed to improve the latency of quantum circuits. Experiments show that by using template matching as a physical synthesis approach, the latency of quantum circuits can be improved by more than 23.55 % on average.

  17. Environment and hydroelectricity colloquium - Synthesis

    International Nuclear Information System (INIS)

    Aelbrecht, Denis; Abadie, Marc; Baril, Dominique; Delacoux, Jean-Yves; Delaunay, Alexis; Loudiere, Daniel; Penalba, Anne; Pont, Didier; Rocq, Sylvie; Roult, Didier; Sheibani, Neda; Thevenet, Regis; Weisrock, Ghislain

    2010-10-01

    This document proposes a synthesis of a colloquium dedicated to the interactions between hydroelectric installations and the environment. The four sessions respectively addressed the impacts of hydroelectric installations on ecosystems and more particularly on pisciculture populations (strategies for migration restoration, development of fish-friendly turbines), the sedimentary management of hydroelectric installations, the implementation of the Water Framework European Directive (Austrian experience, biological assessment criteria), and examples of environmental integration of existing or projected installations

  18. Macrocyclic cyclodiphosphazane : synthesis of chalcogen ...

    Indian Academy of Sciences (India)

    VITTHALRAO S KASHID

    2017-09-06

    Sep 6, 2017 ... Abstract. The synthesis of a Schiff base-appended macrocycle [{P(μ-tBuN)}2(O − m − C6H4CHNCH2)2]2. (1) containing cyclodiphosphazane moieties is described. Reactions of 1 with H2O2 and elemental selenium yielded derivatives tetrakis(oxide) [{P(O)(μ-tBuN)}2(O − m − C6H4CHNCH2)2]2 (2) and.

  19. Expertise synthesis on the CSPE

    International Nuclear Information System (INIS)

    Blonde, G.; Poizat, F.

    2008-01-01

    This document presents a synthesis of the results of an expertise realized on the CSPE, the compensation tax of the electric public service. This tax concerns the management of the electricity production additional costs in isolated areas, the solidarity, a policy to favor the energy efficiency and the renewable energies. The document explains the historical aspects of the tax elaboration, its financial importance, the consequences and the impacts on the competition. (A.L.B.)

  20. Asymmetric Synthesis of Apratoxin E.

    Science.gov (United States)

    Mao, Zhuo-Ya; Si, Chang-Mei; Liu, Yi-Wen; Dong, Han-Qing; Wei, Bang-Guo; Lin, Guo-Qiang

    2016-10-21

    An efficient method for asymmetric synthesis of apratoxin E 2 is described in this report. The chiral lactone 8, recycled from the degradation of saponin glycosides, was utilized to prepare the non-peptide fragment 6. In addition to this "from nature to nature" strategy, olefin cross-metathesis (CM) was applied as an alternative approach for the formation of the double bond. Moreover, pentafluorophenyl diphenylphosphinate was found to be an efficient condensation reagent for the macrocyclization.

  1. A Sustainable Multicomponent Pyrimidine Synthesis.

    Science.gov (United States)

    Deibl, Nicklas; Ament, Kevin; Kempe, Rhett

    2015-10-14

    Since alcohols are accessible from indigestible biomass (lignocellulose), the development of novel preferentially catalytic reactions in which alcohols are converted into important classes of fine chemicals is a central topic of sustainable synthesis. Multicomponent reactions are especially attractive in organic chemistry as they allow the synthesis of large libraries of diversely functionalized products in a short time when run in a combinatorial fashion. Herein, we report a novel, regioselective, iridium-catalyzed multicomponent synthesis of pyrimidines from amidines and up to three (different) alcohols. This reaction proceeds via a sequence of condensation and dehydrogenation steps which give rise to selective C-C and C-N bond formations. While the condensation steps deoxygenate the alcohol components, the dehydrogenations lead to aromatization. Two equiv of hydrogen and water are liberated in the course of the reactions. PN5P-Ir-pincer complexes, recently developed in our laboratory, catalyze this sustainable multicomponent process most efficiently. A total of 38 different pyrimidines were synthesized in isolated yields of up to 93%. Strong points of the new protocol are its regioselectivity and thus the immediate access to pyrimidines that are highly and unsymmetrically decorated with alkyl or aryl substituents. The combination of this novel protocol with established methods for converting alcohols to nitriles now allows to selectively assemble pyrimidines from four alcohol building blocks and 2 equiv of ammonia.

  2. Zeolite membranes for efficient synthesis of biofuels

    OpenAIRE

    Sandström, Linda

    2009-01-01

    The greenhouse effect and the limited fossil oil resources have increased the demand of renewable fuels. Zeolite membranes have potential applications in numerous separation processes, and could be useful in the development of efficient processes for renewable fuel production. Methanol synthesis from synthesis gas is equilibrium limited, and continuous removal of products in a zeolite membrane reactor could improve the productivity of a conventional methanol synthesis process. In this work, m...

  3. Automatic Synthesis of Multilevel Combinational Logic

    DEFF Research Database (Denmark)

    Andersen, Anders C.; Madsen, Jan; Madsen, J.R.

    1989-01-01

    This paper describes a system for the synthesis of multilevel combinational logic, transforming functional description into mask layout. The system includes a logic synthesis part, partly consisting of tools developed at Eindhoven University of Technology, which has been interfaced to the layout ...... synthesis part in the CATOE-system, developed at the DesignCenter of Electronics Institute. The various steps in the transformation are presented together with a complete design example, implementing a multi-output combinational decoder function....

  4. Synthesis by plasma of halogenated poly anilines

    International Nuclear Information System (INIS)

    Enriquez, M.A.; Olayo, M.G.; Cruz, G.J.

    2002-01-01

    In this work polymerization by plasma of aniline with iodine and chlorine bonded chemically to the aniline ring were realized. The results of the synthesis and characterizations are compared with those ones obtained starting from the poly aniline synthesis (P An) doped with iodine, where the dopant was aggregated in the moment of the polymerization. The objective is to study the dopant behavior in the synthesis by plasma in function of the properties of these polymers. (Author)

  5. Matrix-assisted peptide synthesis on nanoparticles.

    Science.gov (United States)

    Khandadash, Raz; Machtey, Victoria; Weiss, Aryeh; Byk, Gerardo

    2014-09-01

    We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides. The matrix-assisted synthesis on nanoparticles was proved by generating various biologically relevant peptides. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  6. Shape-Controlled Gold Nanoparticle Synthesis

    Science.gov (United States)

    2013-09-01

    Shankar, S. S.; Bhargava, S.; Sastry, M. Synthesis of Gold Nanospheres and Nanotriangles by the Turkevich Approach. Journal of Nanoscience and...Accounts of Chemical Research 2008, 41, 1587–1595. 22. Sun, Y.; Xia, Y. Shape-Controlled Synthesis of Gold And Silver Nanoparticles. Science...N.; Griep, M. H.; and Karna, S. P. Chemical vs. Sonochemical Synthesis and Characterization of Silver , Gold, and Hybrid Nanoparticles; ARL-TR-5764

  7. New Hybrid Route to Biomimetic Synthesis

    National Research Council Canada - National Science Library

    Morse, Daniel

    2003-01-01

    To develop economical low-temperature routes to biomimetic synthesis of high-performance composite materials, with control of composition and structure based on the molecular mechanisms controlling...

  8. Quest for the chemical synthesis of proteins.

    Science.gov (United States)

    Engelhard, Martin

    2016-05-01

    The chemical synthesis of proteins has been the wish of chemists since the early 19th century. There were decisive methodological steps necessary to accomplish this aim. Cornerstones were the introduction of the Z-protecting group of Bergmann and Zervas, the development of Solid-phase Peptide Synthesis of Merrifield, and the establishment of Native Chemical Ligation by Kent. Chemical synthesis of proteins has now become generally applicable technique for the synthesis of proteins with tailor made properties which can be applied not only in vitro but also in vivo .Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  9. Astrobiology - The New Synthesis

    Science.gov (United States)

    Sik, A.; Simon, T.

    á vált sötétebb helyekre való költöztetése: mélyen a föld alá helyezik, a forró vulkáni kőzetek hasadékaiba, ahol bőségesen találhatott magának ként, vasat, hidrogént és szenet. A genetikai bizonyítékok alapján a hő- és mélységkedvelők es- 4 nek legközelebb az egyetemes őshöz. [16]. The synthesis Mindezek alapján a földi extremofilek vizsgálata során deríthetjük ki, hogy más égitesteken (egyelőre a Naprendszerben) hol kell keresnünk az életet, és mit kell keresnünk a planetológiai kutatások során egyre jobban megismert szélsőséges környezetekben. Segítségükkel megtudhatjuk, melyek azok az alak- tani, geokémiai, esetleg biokémiai jegyek, amelyek életre utalhatnak; melyek az élet azon alapvető jellemzői, amelyek elég általánosak és biztonsággal kimu- tathatók, milyen műszerekkel kell felszerelnünk a jövő űrszondáit, milyen módszereket kell alkalmaznunk, hogy sikerrel kutathassunk a Földön kívüli élet után. References [1] H. Hargitai et. al., XXXIII. LPSC (2002), Houston, #1261; [2] Origins Roadmap, 2000, JPL; [3] http://www.obspm.fr/encycl/catalog.html [4] http://www.physics.sfsu.edu/~gmarcy/planetsearch/ upsand/upsand.html [5] http://tpf.jpl.nasa.gov/ [6] A. Kereszturi, and A. Sik, XXXI. LPSC (2000), Houston, #1216; [7] S. W. Squyres et. al. (1992) in H. H. Kieffer, et. al.: Mars, University of Arizona Press, Tucson, 523-554; [8] http://www.jpl.nasa.gov/europaorbiter/ [9] www.nineplanets.org [10] http://www.jpl.nasa.gov/cassini/ [11] http://www- curator.jsc.nasa.gov/curator/antmet/ marsmets/alh84001/sample.htm [12] P. Davies: The fifth miracle - The search for the origin of life (1998), Orion; [13] M. T. Madigan and B. L. Marrs: Extremophiles, Scientific American (1997), 276, 82-87; [14] J. A. Lake et al.: Methanococcus Genome, Science (1996), 274, 901-905; [15] N. C. Kyrpides and G. J. Olsen: Archaeal and bacterial hyperthermophiles: Horizontal gene exchange or common ancestry?, Trends in

  10. Web-Mediated Knowledge Synthesis for Educators

    Science.gov (United States)

    DeSchryver, Michael

    2015-01-01

    Ubiquitous and instant access to information on the Web is challenging what constitutes 21st century literacies. This article explores the notion of Web-mediated knowledge synthesis, an approach to integrating Web-based learning that may result in generative synthesis of ideas. This article describes the skills and strategies that may support…

  11. Heteropolyacids in synthesis of benzoyl hydrazone derivatives

    Directory of Open Access Journals (Sweden)

    Sodeh Sadjadi

    2009-12-01

    Full Text Available Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid hydrazide and aldehyde and ketone derivatives. The synthesis of N-acetyl and N-benzoyl derivatives has also been performed by the reaction of obtained benzoyl hydrazones with acylcholorides in presence of this kind of heteropolyacids.

  12. Synthesis and characterization of saturated polyester and ...

    Indian Academy of Sciences (India)

    Synthesis and characterization of saturated polyester and nanocomposites derived from glycolyzed PET waste ... construction industries. PET is widely used in the packaging of beverages and drugs. ... ing the synthesis of saturated polyester (from GPET waste). This has been done for the estimation of the maximum. 277 ...

  13. Natural Synthesis: Where culture met academics | Chinyere ...

    African Journals Online (AJOL)

    This study attempts a detailed analysis of Natural Synthesis, the first meeting point of culture and academics in Nigeria. The study contextualized Natural Synthesis and the Nigerian traditional art and culture in relations to its transformation through the proponents of the philosophy. It discusses in details the genesis of the ...

  14. Alum an Efficient Catalyst for Erlenmeyer Synthesis

    African Journals Online (AJOL)

    NICO

    found to be useful precursors for the synthesis of amino acids,2 peptides,3 and ... tuted imidazoles,21h etc. However, there are no examples of the use of alum as a catalyst for the synthesis of azlactone deriva- tives. 2. Result and Discussion .... 12 P.S. Rao and R.V. Venkataratnam, Indian J. Chem, 1994, 33B, 984–985.

  15. Synthesis of Lipophilic Guanine N-9 Derivatives

    DEFF Research Database (Denmark)

    Wamberg, Michael C; Pedersen, Pernille L; Löffler, Philipp M G

    2017-01-01

    the synthesis of five new guanine-N9 derivatives bearing alkyl chains with different attachment chemistries, exploiting a synthesis pathway that allows a flexible choice of hydrophobic anchor moiety. In this study, these guanine derivatives were functionalized with C10 chains for insertion into decanoic acid...

  16. Urea synthesis in patients with chronic pancreatitis

    DEFF Research Database (Denmark)

    Hamberg, Ole; Andersen, Vibeke; Sonne, J

    2001-01-01

    Up-regulation of urea synthesis by amino acids and dietary protein intake may be impaired in patients with chronic pancreatitis (CP) due to the reduced glucagon secretion. Conversely, urea synthesis may be increased as a result of the chronic inflammation. The aims of the study were to determine...

  17. Combustion synthesis and photoluminescence study of silicate ...

    Indian Academy of Sciences (India)

    Silicate based bioceramics are promising candidates as biomaterials for tissue engineering. The combustion synthesis method provides control on the morphology and particle size of the synthesized material. This paper discusses the combustion synthesis of akermanite (Ca2MgSi2O7 and Sr2MgSi2O7), which has been ...

  18. Woodward's Synthesis of Vitamin B12

    Indian Academy of Sciences (India)

    Woodward's Synthesis of Vitamin B12. Adil Ghani Khan is a final year student of BSc. (Honours) in Chemistry at. St. Stephen's College,. Delhi University. S V Eswaran is an accomplished Organic. Chemist and principal of. Deshbandhu College,. Delhi University. Keywords. Asymmetric synthesis, chira!. Adil Ghani Khan and ...

  19. Swelling of rat hepatocytes stimulates glycogen synthesis

    NARCIS (Netherlands)

    Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

    1990-01-01

    In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

  20. Novel Green Synthesis and Characterization of Nanopolymer ...

    African Journals Online (AJOL)

    Purpose: To develop a novel approach to green synthesis of nano-polymer porous gold oxide nanoparticles, and examine the effects of the temperatures on their surface. Methods: Green synthesis of nano-polymer porous gold oxide nanoparticles (GONPs) using cetyle trimethylammonium bromide (CTAB) surfactant with a ...

  1. Synthesis of graphene using gamma radiations

    Indian Academy of Sciences (India)

    Abstract. Considering the advantages of radiolytic synthesis such as the absence of toxic chemical as a reducing agent, uniform distribution of reducing agent and high purity of product, the synthesis of graphene (rGO) from graphene oxide (GO) by the gamma irradiation technique using a relatively low dose rate of 0.24 kGy ...

  2. Synthesis of graphene using gamma radiations

    Indian Academy of Sciences (India)

    Considering the advantages of radiolytic synthesis such as the absence of toxic chemical as a reducing agent, uniform distribution of reducing agent and high purity of product, the synthesis of graphene (rGO) from graphene oxide (GO) by the gamma irradiation technique using a relatively low dose rate of 0.24 kGy h−1 has ...

  3. Synthesis, spectroscopic characterization and electronic structure of ...

    Indian Academy of Sciences (India)

    Unknown

    Copper(I) carbene complex; carbene complex synthesis; Cu(I)–carbene electronic structure. 1. Introduction. Metal carbene complexes are arguably the most ver- satile organometallic reagents that have been devel- oped for organic synthesis.1 Different reactions of these complexes have been reported since their dis-.

  4. Sulfonated graphenes catalyzed synthesis of expanded porphyrins ...

    Indian Academy of Sciences (India)

    A newer synthesis of sulfonic acid functionalized graphenes have been developed, which have been characterized, examined as heterogeneous solid acid carbocatalyst in the synthesis of selected expanded porphyrins in different reaction conditions. This environment-friendly catalyst avoids the use of toxic catalysts and ...

  5. HMM Adaptation for child speech synthesis

    CSIR Research Space (South Africa)

    Govender, Avashna

    2015-09-01

    Full Text Available Hidden Markov Model (HMM)-based synthesis in combination with speaker adaptation has proven to be an approach that is well-suited for child speech synthesis. This paper describes the development and evaluation of different HMM-based child speech...

  6. Synthesis, characterization and application of semiconducting oxide ...

    Indian Academy of Sciences (India)

    Nanostructured; Cu2O nanostructures; electrolysis based oxidation; aligned ZnO nanorods. Abstract. In the present study, we report the synthesis, characterization and application of nanostructured oxide materials. The oxide ... The copper electrode served as a sacrificial anode for the synthesis of different nanostructures.

  7. Automatic Synthesis of Robust and Optimal Controllers

    DEFF Research Database (Denmark)

    Cassez, Franck; Jessen, Jan Jacob; Larsen, Kim Guldstrand

    2009-01-01

    In this paper, we show how to apply recent tools for the automatic synthesis of robust and near-optimal controllers for a real industrial case study. We show how to use three different classes of models and their supporting existing tools, Uppaal-TiGA for synthesis, phaver for verification...

  8. Synthesis of ammonia with microwave plasma

    International Nuclear Information System (INIS)

    Xu Wenguo; Yu Aimin; Liu Jun; Jin Qinhan

    1991-01-01

    THe synthesis of ammonia absorbed on 13X zeolite with the aid of microwave plasma is described. The ammonia molecule absorbed on 13X zeolite as ammonium ions were detected by IR spectroscopy. The results obtained show that the ammonia synthesis is facilitated by the surface reactions of NH x (x = 1, 2) radicals adsorbed on zeolite with hydrogen atoms

  9. Synthesis, Characterization and Antibacterial Activity of Imidazole ...

    African Journals Online (AJOL)

    NICO

    Synthesis, Characterization and Antibacterial Activity of. Imidazole Derivatives of 1,10-Phenanthroline and their .... Synthesis of Ligands (L1, L2). Ligands (L1. , L2) were synthesized by a method similar to one ... (50 mL). Dropwise addition of concentrated aqueaus ammonia to neutralize gave a yellow precipitate, which was ...

  10. Conceptual problems with remote element synthesis

    Indian Academy of Sciences (India)

    The notion of remote element synthesis has recently been modified to explain the presence of nucleogenetic isotopic anomalies and decay products of short-lived nuclides by injection of a small amount of exotic nucleogenetic material. Even with this modification, remote element synthesis seems inconsistent with the ...

  11. Standardized chemical synthesis of Pseudomonas aeruginosa pyocyanin

    Directory of Open Access Journals (Sweden)

    Rajkumar Cheluvappa

    2014-01-01

    As we have extracted pyocyanin both from P. aeruginosa cultures, and via chemical synthesis; we know the procedural and product-quality differences. We endorse the relative ease, safety, and convenience of using the chemical synthesis described here. Crucially, our “naturally endotoxin-free” pyocyanin can be extracted easily without using infectious bacteria.

  12. Heteropolyacids in synthesis of benzoyl hydrazone derivatives ...

    African Journals Online (AJOL)

    Keggin type of heteropolyacids as green reusable and efficient catalyst was used in the synthesis of benzoyl hydrazones from reaction of benzoic acid hydrazide and aldehyde and ketone derivatives. The synthesis of N-acetyl and N-benzoyl derivatives has also been performed by the reaction of obtained benzoyl ...

  13. MICROWAVE-ASSISTED SYNTHESIS OF SOME NITRO ...

    African Journals Online (AJOL)

    Chem. Life Sci. 2014, 347, 387-397. 32. Menteşe, E. Efficient microwave assisted synthesis of some new benzimidazoles containing the mebendazole nucleus. J. Chem. Res. 2013, 37, 168-170. 33. Menteşe, E.; Yılmaz, F.; Mutlu, F.; Kahveci, B. Synthesis of new coumarin containing benzimidazole derivatives. J. Chem. Res.

  14. Properties and synthesis of milrinone

    Directory of Open Access Journals (Sweden)

    Mirković Jelena M.

    2013-01-01

    Full Text Available Milrinone, 1,6-dihydro-2-methyl-6-oxo-[3,4’-bipyridine]-5-carbonitrile, is a positive inotropic cardiotonic agent with vasodilator properties that acts as selective phosphodiesterase 3 inhibitor in cardiac and vascular smooth muscle. Trade names of milrinone are Primacor, Corotrop, Corotrope, and Milrila. Milrinone, an amrinone derivative, is 20 to 50 times more active than amrinone and possesses reduced propensity to side effects. The use of milrinone has created controversy in the medical as the result of increased mortality rate among patients that received high amounts of milrinone in oral form. Reaserch show that it can be benifitial for patients with severe congestive heart failure when used as short-time intravenous therapy. Milrinone properties, stability, as well as mechanism of action and synthesis under laboratory and industry conditions have been described in this paper. For industrial purposes milrinone is synthesized by condensation of cyanoacetamide with 4-(dimethylamino-3-(4-pyridinyl-3-buten-2-one and 4-ethoxy-3-(4-pyridinyl-3-buten-2-one in presence of a base, or by the reaction of 1-(4-pyridinyl- 2-propanone with ethoxymethylenmalononitrile or 4-alkoxy-3-(4-pyridinyl-3-buten-2-one with malononitrile without the use of external base. The starting compound for these syntheses is 4-picoline. Alternative synthesis of milrinone starts from 2-methyl-3-(4-pyridylidiene-1,1,5-tricyano-1,4-pentadiene-5-carboxamide and 2-methyl-6-oxo-1,6-dihydro-3,4’-bipyridine-5-carboxamide. Lastly, methods for milrinone synthesis in laboratory, injection preparation and purification have been summarized.

  15. A Concise Synthesis of Forskolin.

    Science.gov (United States)

    Hylse, Ondřej; Maier, Lukáš; Kučera, Roman; Perečko, Tomáš; Svobodová, Aneta; Kubala, Lukáš; Paruch, Kamil; Švenda, Jakub

    2017-10-02

    A 24-step synthesis of (±)-forskolin is presented, which delivered hundred milligram quantities of this complex diterpene in one pass. Transformations key to our approach include: a) a strategic allylic transposition, b) stepwise assembly of a sterically encumbered isoxazole ring, and c) citric acid-modified Upjohn dihydroxylation of a resilient tetrasubstituted olefin. The developed route has exciting potential for the preparation of new forskolin analogues inaccessible by semisynthesis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Cellulose Synthesis in Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Alan R. White; Ann G. Matthysse

    2004-07-31

    We have cloned the celC gene and its homologue from E. coli, yhjM, in an expression vector and expressed the both genes in E. coli; we have determined that the YhjM protein is able to complement in vitro cellulose synthesis by extracts of A. tumefaciens celC mutants, we have purified the YhjM protein product and are currently examining its enzymatic activity; we have examined whole cell extracts of CelC and various other cellulose mutants and wild type bacteria for the presence of cellulose oligomers and cellulose; we have examined the ability of extracts of wild type and cellulose mutants including CelC to incorporate UDP-14C-glucose into cellulose and into water-soluble, ethanol-insoluble oligosaccharides; we have made mutants which synthesize greater amounts of cellulose than the wild type; and we have examined the role of cellulose in the formation of biofilms by A. tumefaciens. In addition we have examined the ability of a putative cellulose synthase gene from the tunicate Ciona savignyi to complement an A. tumefaciens celA mutant. The greatest difference between our knowledge of bacterial cellulose synthesis when we started this project and current knowledge is that in 1999 when we wrote the original grant very few bacteria were known to synthesize cellulose and genes involved in this synthesis were sequenced only from Acetobacter species, A. tumefaciens and Rhizobium leguminosarum. Currently many bacteria are known to synthesize cellulose and genes that may be involved have been sequenced from more than 10 species of bacteria. This additional information has raised the possibility of attempting to use genes from one bacterium to complement mutants in another bacterium. This will enable us to examine the question of which genes are responsible for the three dimensional structure of cellulose (since this differs among bacterial species) and also to examine the interactions between the various proteins required for cellulose synthesis. We have carried out one

  17. Synthesis document of the presentations

    International Nuclear Information System (INIS)

    Vrousos, C.; Choudat, D.; Dutrillaux, B.

    2001-01-01

    This colloquium has been organized to answer questions from health professionals. They are more and more confronted to public information about public health and to patient anxiety. The aim of the interventions is to realize a clearly and comprehensive synthesis of events concerning the nuclear and health domain during 2000. The following three sessions deal with this subject: occupational diseases and ionizing radiation; the public information and attitude facing nuclear accidents and especially Chernobyl; medical and sanitary aspects of a nuclear accident: management and follow up of people. (A.L.B.)

  18. Ibuprofen: Synthesis, production and properties

    Directory of Open Access Journals (Sweden)

    Mijin Dušan Ž.

    2003-01-01

    Full Text Available Since its introduction in 1969, ibuprofen has become one of the most common painkillers in the world. Ibuprofen in an NSAID (non-steroidal anti-inflammatory drug and like other drugs of its class it possesses analgetic, antipyretic and anti-inflammatory properties. While ibuprofen is a relatively simple molecule, there is still sufficient structural complexity to ensure that a large number of different synthetic approaches are possible. Since the introduction of pharmaceutical products containing ibuprofen, industrial and academic scientists have developed many potential production processes. This paper describes the history, synthesis and production, as well as the properties and stability of ibuprofen.

  19. Biological synthesis of silver nanoparticles

    International Nuclear Information System (INIS)

    Maliszewska, I; Szewczyk, K; Waszak, K

    2009-01-01

    Fungus-mediated synthesis of silver nanoparticles is reported. The nanosilver was formed in contact with the cell-free filtrate of Penicillium strain studied. The nanoparticles were characterized by means of the UV-Vis spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The synthesized nanosilver showed a absorbed maximum at 425 nm in the visible region. The SEM characterization of the fungus cells treated with silver nitrite indicated that the protein might be responsible for the reduction of silver ions. Transmission electron microscopy (TEM) micrograph showed formation of silver nanoparticles in the range of 10-100 nm.

  20. EXOPOLYSACCHARIDES SYNTHESIS ON INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    T.P.

    2016-04-01

    Full Text Available Data from the literature and our own studies on the synthesis of microbial exopolysaccharides on various industrial waste (food industry, agricultural sector, biodiesel production, etc. are reviewed here. Utilization of industrial waste to obtain exopolysaccharides will solve not only the problem of secondary raw materials accumulation, but also will reduce the costs of the biosynthesis of practically valuable metabolites. In addition, some kinds of waste have a number of advantages compared to traditional carbohydrate substrates: aside from environmental health benefits, there are technological ones, like the presence of growth factors. There is also no need to use anti-foam substances and substrate sterilization in the latter case.

  1. The synthesis paradigm in genetics.

    Science.gov (United States)

    Rice, William R

    2014-02-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics--and other fields of biology--are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous "-omics" data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time.

  2. Computer Music Synthesis and Composition

    Science.gov (United States)

    Ayers, Lydia

    What is computer music composition? Composers are using the computer for everything from MIDI instruments communicating with computer sequencers, pitch trackers analyzing the sounds of acoustic instruments and converting them to pitch information, live performers with recorded music, performers with interactive computer programs, computer music produced by dancers using sensors, automatic music composition with the computer programs composing the music, composing with sounds or parts of sounds rather than notes, how to structure the use of time, composing with timbres, or the colors of sounds, and timbre morphing, such as a gong morphing to a voice, composing with textures and texture morphing, such as fluttertonguing morphing to pitch, granular synthesis, trills and convolution.

  3. Total Synthesis of Calophyline A.

    Science.gov (United States)

    Li, Guang; Xie, Xiaoni; Zu, Liansuo

    2016-08-22

    Reported herein is the total synthesis of calophyline A, an indoline natural product possessing distinct ring connectivity which has not been synthesized previously. The synthetic route features several key transformations, including an aza-pinacol rearrangement to construct the nitrogen-containing bridged [3.2.2] bicycle, a Heck cyclization to assemble the fused 6/5/6/5 ring system, and a challenging late-stage aldol reaction to generate both a neopentyl quaternary stereogenic center and an oxygen-containing bridged [3.2.1] bicycle. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Synthesis of colloidal silica dumbbells.

    Science.gov (United States)

    Johnson, Patrick M; van Kats, Carlos M; van Blaaderen, Alfons

    2005-11-22

    We describe the synthesis and characterization of stable suspensions of monodisperse fluorescently labeled silica dumbbell particles. Pure dispersions of silica dumbbells with center-to-center lengths from 174 nm to 2.3 microm were produced with a variety of aspect ratios. Individual particles in concentrated dispersions of these particles could be imaged with confocal microscopy. These particles can be used as a colloidal model system for addressing fundamental questions about crystal and glass formation of low-aspect-ratio anisotropic particles. They also have potential in photonic applications and electro-optical devices.

  5. Synthesis of Ru alkylidene complexes

    Directory of Open Access Journals (Sweden)

    Renat Kadyrov

    2011-01-01

    Full Text Available The present work describes the robust synthesis of Ru alkylidene complexes (PCy32Cl2Ru=CHR – precursors for metathesis catalysts. Moreover, the dynamic behavior of complexes where R = 2-naphthyl and 2-thienyl was studied. 1H NMR techniques were employed to establish the preferred conformations in solution for both complexes and the energy barrier for rotation around single (Ru=CH–C(thienyl bond was estimated (ΔG≠303K = 12.6 kcal/mol.

  6. Ammonia synthesis at low temperatures

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Logadottir, Ashildur; Nørskov, Jens Kehlet

    2000-01-01

    Density functional theory (DFT) calculations of reaction paths and energies for the industrial and the biological catalytic ammonia synthesis processes are compared. The industrial catalyst is modeled by a ruthenium surface, while the active part of the enzyme is modeled by a MoFe6S9 complex...... have been carried out to evaluate its feasibility. The calculations suggest that it might be possible to catalytically produce ammonia from molecular nitrogen at low temperatures and pressures, in particular if energy is fed into the process electrochemically. (C) 2000 American Institute of Physics....

  7. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  8. Synthesis of nanoparticles and nanomaterials biological approaches

    CERN Document Server

    Abdullaeva, Zhypargul

    2017-01-01

    This book covers biological synthesis approaches for nanomaterials and nanoparticles, including introductory material on their structure, phase compositions and morphology, nanomaterials chemical, physical, and biological properties. The chapters of this book describe in sequence the synthesis of various nanoparticles by microorganisms, bacteria, yeast, algae, and actynomycetes; plant and plant extract-based synthesis; and green synthesis methods. Each chapter provides basic knowledge on the synthesis of nanomaterials, defines fundamental terms, and aims to build a solid foundation of knowledge, followed by explanations, examples, visual photographs, schemes, tables and illustrations. Each chapter also contains control questions, problem drills, as well as case studies that clarify theory and the explanations given in the text. This book is ideal for researchers and advanced graduate students in materials engineering, biotechnology, and nanotechnology fields. As a reference book this work is also appropriate ...

  9. Protein chemical synthesis in drug discovery.

    Science.gov (United States)

    Liu, Fa; Mayer, John P

    2015-01-01

    The discovery of novel therapeutics to combat human disease has traditionally been among the most important goals of research chemists. After a century of innovation, state-of-the-art chemical protein synthesis is now capable of efficiently assembling proteins of up to several hundred residues in length from individual amino acids. By virtue of its unique ability to incorporate non-native structural elements, chemical protein synthesis has been seminal in the recent development of several novel drug discovery technologies. In this chapter, we review the key advances in peptide and protein chemistry which have enabled our current synthetic capabilities. We also discuss the synthesis of D-proteins and their applications in mirror image phage-display and racemic protein crystallography, the synthesis of enzymes for structure-based drug discovery, and the direct synthesis of homogenous protein pharmaceuticals.

  10. Feature-aware natural texture synthesis

    KAUST Repository

    Wu, Fuzhang

    2014-12-04

    This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis quality can be affected adversely if the texture elements in an example display spatially varied patterns, such as perspective distortion, the composition of different sub-textures, and variations in global color pattern as a result of complex illumination. This issue is common in natural textures and is a fundamental challenge for previously developed methods. Thus, we address it from a feature point of view and propose a feature-aware approach to synthesize natural textures. The synthesis process is guided by a feature map that represents the visual characteristics of the input texture. Moreover, we present a novel adaptive initialization algorithm that can effectively avoid the repeat and verbatim copying artifacts. Our approach improves texture synthesis in many images that cannot be handled effectively with traditional technologies.

  11. Synthesis in the liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    1943-03-11

    Justification is presented for an I.G. Farben patent on synthesis of hydrocarbons from carbon monoxide and hydrogen in the liquid phase. Tracing the history of the process, the report notes that Pier worked out the basic patent in 1928. Duftschmid of Farben/Oppau subsequently worked out a variation of the process using for the fluid medium a synthesis product consisting mainly of products vaporizing in the reaction. The process used fixed-bed catalysts. Ruhrchemie A.G. objected to this patent on grounds that the process was already known. Meanwhile, Michael of Farben/Ludwigshafen devised another variation using mainly a finely distributed sintered catalyst and very fast stirring. The process required a high boiling, practically non-volatile liquid phase to keep the finely distributed catalyst in motion in the liquid during the reaction. A good distribution of carbon monoxide, hydrogen, and catalyst was obtained by having the gases enter either through a filter plate or by a rapid stirring of the liquid. The report concludes that since Michael's process was not for fixed catalysts, it was in no way dependent on the Duftschmid process or on Oppau's patent rights. A detailed chronology of work on the processes is included.

  12. Homeobox genes and melatonin synthesis

    DEFF Research Database (Denmark)

    Rohde, Kristian; Møller, Morten; Rath, Martin Fredensborg

    2014-01-01

    Nocturnal synthesis of melatonin in the pineal gland is controlled by a circadian rhythm in arylalkylamine N-acetyltransferase (AANAT) enzyme activity. In the rodent, Aanat gene expression displays a marked circadian rhythm; release of norepinephrine in the gland at night causes a cAMP-based indu......Nocturnal synthesis of melatonin in the pineal gland is controlled by a circadian rhythm in arylalkylamine N-acetyltransferase (AANAT) enzyme activity. In the rodent, Aanat gene expression displays a marked circadian rhythm; release of norepinephrine in the gland at night causes a c......AMP-based induction of Aanat transcription. However, additional transcriptional control mechanisms exist. Homeobox genes, which are generally known to encode transcription factors controlling developmental processes, are also expressed in the mature rodent pineal gland. Among these, the cone-rod homeobox (CRX......) transcription factor is believed to control pineal-specific Aanat expression. Based on recent advances in our understanding of Crx in the rodent pineal gland, we here suggest that homeobox genes play a role in adult pineal physiology both by ensuring pineal-specific Aanat expression and by facilitating c...

  13. Mixed Alcohol Synthesis Catalyst Screening

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Mark A.; White, James F.; Stevens, Don J.

    2007-09-03

    National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

  14. Fluxnet Synthesis Dataset Collaboration Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Deborah A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Humphrey, Marty [Univ. of Virginia, Charlottesville, VA (United States); van Ingen, Catharine [Microsoft. San Francisco, CA (United States); Beekwilder, Norm [Univ. of Virginia, Charlottesville, VA (United States); Goode, Monte [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jackson, Keith [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rodriguez, Matt [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Weber, Robin [Univ. of California, Berkeley, CA (United States)

    2008-02-06

    The Fluxnet synthesis dataset originally compiled for the La Thuile workshop contained approximately 600 site years. Since the workshop, several additional site years have been added and the dataset now contains over 920 site years from over 240 sites. A data refresh update is expected to increase those numbers in the next few months. The ancillary data describing the sites continues to evolve as well. There are on the order of 120 site contacts and 60proposals have been approved to use thedata. These proposals involve around 120 researchers. The size and complexity of the dataset and collaboration has led to a new approach to providing access to the data and collaboration support and the support team attended the workshop and worked closely with the attendees and the Fluxnet project office to define the requirements for the support infrastructure. As a result of this effort, a new website (http://www.fluxdata.org) has been created to provide access to the Fluxnet synthesis dataset. This new web site is based on a scientific data server which enables browsing of the data on-line, data download, and version tracking. We leverage database and data analysis tools such as OLAP data cubes and web reports to enable browser and Excel pivot table access to the data.

  15. Clinical documentation: composition or synthesis?

    Science.gov (United States)

    Mamykina, Lena; Vawdrey, David K; Stetson, Peter D; Zheng, Kai; Hripcsak, George

    2012-01-01

    To understand the nature of emerging electronic documentation practices, disconnects between documentation workflows and computing systems designed to support them, and ways to improve the design of electronic documentation systems. Time-and-motion study of resident physicians' note-writing practices using a commercial electronic health record system that includes an electronic documentation module. The study was conducted in the general medicine unit of a large academic hospital. During the study, 96 note-writing sessions by 11 resident physicians, resulting in close to 100 h of observations were seen. Seven of the 10 most common transitions between activities during note composition were between documenting, and gathering and reviewing patient data, and updating the plan of care. The high frequency of transitions seen in the study suggested that clinical documentation is fundamentally a synthesis activity, in which clinicians review available patient data and summarize their impressions and judgments. At the same time, most electronic health record systems are optimized to support documentation as uninterrupted composition. This mismatch leads to fragmentation in clinical work, and results in inefficiencies and workarounds. In contrast, we propose that documentation can be best supported with tools that facilitate data exploration and search for relevant information, selective reading and annotation, and composition of a note as a temporal structure. Time-and-motion study of clinicians' electronic documentation practices revealed a high level of fragmentation of documentation activities and frequent task transitions. Treating documentation as synthesis rather than composition suggests new possibilities for supporting it more effectively with electronic systems.

  16. Abiogenic synthesis on terrestrial orbit

    Science.gov (United States)

    Simakov, Michael B.; Kuzicheva, Evgenia; Gontareva, Natalia

    Meteorites probably played a central role in the evolution of life. Due to the structure, they tend to adsorb organic compounds and catalyze a variety of organic reactions critical to scenarios of life’s origins. We have shown experimentally that extraterrestrial minerals can catalyze the formation of peptides and nucleotides. The present study was performed onboard different Russian space stations (BION, COSMOS, and MIR) with various duration, altitude, and radiation conditions. Irradiation of solid samples, free or admixed with certain minerals, was the major task of future space flight experiments, planned for performing onboard Russian space satellite Bion-M. The «simulated space ice conditions» experiments have shown the synthesis of simple biochemical compounds in the form of amino acid’s precursors and pyrimidine bases (uracil, cyrosine and thymine) of the nucleic acids. Our investigation dealt with further reaction of nucleic acid components to nucleotides - main components of RNA and DNA, and single aminoacids to oligopeptides. We investigated two types of reactions: (1) abiogenic synthesis of nucleotides from mixtures of nucleoside + inorganic phosphate; (2) abiogenic synthesis of dipeptides from mixtures of simple amino acids. The reaction mixture in the form of a solid film contains (1) nucleoside and dihydrogen phosphate; (2) two different amino acids. Seven different nucleosides (thymidine, cytidine, uracil, adenosine or deoxyadenosine, guanosine or deoxyguanosine) and four mixtures of aromatic (tyrosine or triptophan) and aliphatic (glycine or alanine) amino acids were investigated. Mixtures were irradiated as solid films with different sources of energy: (1) VUV-light of 145 nm; (2) high energy protons (2-6 MeV); and (3) were installed on the surface of biosputnik in outstanding container when they were exposed to the action of all spectra of the open space energy sources during the entire time of flight. We have shown experimentally that the

  17. Bioinspired synthesis of magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    David, Anand [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The synthesis of magnetic nanoparticles has long been an area of active research. Magnetic nanoparticles can be used in a wide variety of applications such as magnetic inks, magnetic memory devices, drug delivery, magnetic resonance imaging (MRI) contrast agents, and pathogen detection in foods. In applications such as MRI, particle uniformity is particularly crucial, as is the magnetic response of the particles. Uniform magnetic particles with good magnetic properties are therefore required. One particularly effective technique for synthesizing nanoparticles involves biomineralization, which is a naturally occurring process that can produce highly complex nanostructures. Also, the technique involves mild conditions (ambient temperature and close to neutral pH) that make this approach suitable for a wide variety of materials. The term 'bioinspired' is important because biomineralization research is inspired by the naturally occurring process, which occurs in certain microorganisms called 'magnetotactic bacteria'. Magnetotactic bacteria use biomineralization proteins to produce magnetite crystals having very good uniformity in size and morphology. The bacteria use these magnetic particles to navigate according to external magnetic fields. Because these bacteria synthesize high quality crystals, research has focused on imitating aspects of this biomineralization in vitro. In particular, a biomineralization iron-binding protein found in a certain species of magnetotactic bacteria, magnetospirillum magneticum, AMB-1, has been extracted and used for in vitro magnetite synthesis; Pluronic F127 gel was used to increase the viscosity of the reaction medium to better mimic the conditions in the bacteria. It was shown that the biomineralization protein mms6 was able to facilitate uniform magnetite synthesis. In addition, a similar biomineralization process using mms6 and a shorter version of this protein, C25, has been used to synthesize cobalt ferrite

  18. Method of production of ammonia synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    1943-09-10

    In the catalytic synthesis of complicated hydrocarbons from carbon monoxide and hydrogen at normal or slightly increased pressures by the Fischer--Tropsch process, or carried out at higher pressures in some other proposals, the synthesis gas was incompletely transformed. After the conclusion of the synthesis, the residual gas, upon the separation of the liquid constituents, contained, in addition to the unreacted carbon moxoxide and hydrogen, also considerable amounts of methane, carbon dioxide, and nitrogen from the original synthesis gas. This residual gas had been used as fuel. It was, however, pure and contained no sulfur or other catalyst poisons and burning it was considered uneconomical. It was proposed to make better use of it by using it as fuel. It was, however, pure and contained no sulfur or other catalyst poisons and burning it was considered uneconomical. It was proposed to make better use of it by using it as a raw material for the production of synthesis gas by decomposing the methane present in it with steam according to the equation CH/sub 4/ + H/sub 2/O = CO + 3H/sub 2/. This conversion was to be brought about either by a return to the producers or else in special splitting units. Also, it had been found that the residual gas, possibly even in the presence of oxygen compounds, could be conveniently used for the synthesis of ammonia. Several examples of ammonia synthesis were discussed.

  19. Synthesis of ammonia using sodium melt.

    Science.gov (United States)

    Kawamura, Fumio; Taniguchi, Takashi

    2017-09-14

    Research into inexpensive ammonia synthesis has increased recently because ammonia can be used as a hydrogen carrier or as a next generation fuel which does not emit CO 2 . Furthermore, improving the efficiency of ammonia synthesis is necessary, because current synthesis methods emit significant amounts of CO 2 . To achieve these goals, catalysts that can effectively reduce the synthesis temperature and pressure, relative to those required in the Haber-Bosch process, are required. Although several catalysts and novel ammonia synthesis methods have been developed previously, expensive materials or low conversion efficiency have prevented the displacement of the Haber-Bosch process. Herein, we present novel ammonia synthesis route using a Na-melt as a catalyst. Using this route, ammonia can be synthesized using a simple process in which H 2 -N 2 mixed gas passes through the Na-melt at 500-590 °C under atmospheric pressure. Nitrogen molecules dissociated by reaction with sodium then react with hydrogen, resulting in the formation of ammonia. Because of the high catalytic efficiency and low-cost of this molten-Na catalyst, it provides new opportunities for the inexpensive synthesis of ammonia and the utilization of ammonia as an energy carrier and next generation fuel.

  20. Exergy analysis of industrial ammonia synthesis

    International Nuclear Information System (INIS)

    Kirova-Yordanova, Zornitza

    2004-01-01

    Exergy consumption of ammonia production plants depends strongly on the ammonia synthesis loop design. Due to the thermodynamically limited low degree of conversion of hydrogen-nitrogen mixture to ammonia, industrial ammonia synthesis is implemented as recycle process (so-called 'ammonia synthesis loop'). Significant quantities of reactants are recycled back to reactor, after the removal of ammonia at low temperatures. Modern ammonia synthesis plants use well-developed heat- and cold recovery to improve the reaction heat utilisation and to reduce the refrigeration costs. In this work, the exergy method is applied to estimate the effect of the most important process parameters on the exergy efficiency of industrial ammonia synthesis. A specific approach, including suitable definitions of the system boundaries and process parameters, is proposed. Exergy efficiency indexes are discussed in order to make the results applicable to ammonia synthesis loops of various designs. The dependence of the exergy losses on properly selected independent process parameters is studied. Some results from detailed exergy analysis of the most commonly used ammonia synthesis loop design configurations at a wide range of selected parameters values are shown

  1. Drug Development of the Antimalarial Agent Artemisinin: Total Synthesis, Analog Synthesis, and Structure-Activity Relationship Studies

    Science.gov (United States)

    1990-08-15

    jHoluenesulfonyl hydrazide in tetrahydrofuran (THF), solvolysis of the ketal group and subsequent hydrazone formation was observed. Under base...ARTEMISININ: TOTAL SYNTHESIS , ANALOG SYNTHESIS , AND STRUCTURE-ACTIVITY RELATIONSHIP STUDIES mc Mitchell A. Avery, Ph.D. SRI International...Antimalarial Agent Artemisinin: Total Synthesis , Analog Synthesis and Structure-Activity Relationship Studies 12 PERSONAL AUTHOR(S) Mitchell A

  2. Synthesis

    International Nuclear Information System (INIS)

    Voinis, Sylvie; Lalieux, Philippe; Thury, Marc; Horseman, Steve

    2001-01-01

    To prevent radioactive contamination and undue exposure to the public, it is required that long-lived and/or high-level radioactive wastes be isolated from the human environment for a very long period of time. For the purpose of isolating such wastes, the basic concept of deep disposal is to place packaged waste in a geological formation such as clay. One of main functions of the geological formation is to isolate waste from moving groundwater, thus minimising lixiviation of waste and advective radionuclide transport and, hence the amount of radionuclides that could reach the human environment. Improving our understanding of processes that might affect the containment properties of the geological barrier can reduce uncertainties about the performance of the repository. In particular, during the stepwise development of the research programme, it is important to clarify if fractures that might be induced by the excavation of the underground facilities might have a significant impact on the radiological safety of a repository in a host formation such as clay. In this framework, the self- healing properties of argillaceous media - often quoted as one of the advantages of such host formations - play a major role, notably in reducing the long-term impacts of such induced fracturing. Twenty-six participants representing several national waste management organisations, regulatory authorities, government agencies and the academic community from the OECD member countries and the EC took part in the Topical Session. The session was mainly aimed at exchanging information on: The general point of view on self-healing from geomechanical and geochemical experts; The approaches that are or will be followed by the various organisations in order to deal with the self-healing. The geological settings covered in the presentations related to the whole range of argillaceous media relevant to the disposal of radioactive wastes, including poorly indurated clays and indurated mud-stones, and shales. The purpose of these proceedings is to provide on the one hand a brief summary of the technical presentations and a record of the main conclusions and outcomes and, on the other hand, a compilation of the presentations' abstracts. very informative presentations provided an overview of the spectrum of the topic; such multidisciplinary overview was - to the knowledge of the Clay Club members - not available before the session; they demonstrated the necessity to consider self-healing in all types of argillaceous media considered as potential host formation; they illustrated the need to reconcile the geomechanical and the geochemical approaches vis-a-vis the self-healing. The discussions focused initially on the clarification of the two phrases 'self-healing' and 'self-sealing'

  3. Synthesis,

    Directory of Open Access Journals (Sweden)

    Ganesan Vanangamudi

    2017-02-01

    Full Text Available Twelve 2,5-dimethyl-3-thienyl chalcones [E-1-(2,5-dimethyl-3-thienyl-3-(substituted phenyl-2-propen-1-ones] have been synthesized by Claisen–Schmidt condensation of 3-acetyl-2,5-dimethyl furon and substituted benzaldehydes. Yields of the chalcones are more than 80%. These chalcones were characterized by their physical constants and spectral data. The group frequencies of infrared ν(cm−1 of CO s-cis and s-trans, CH in-plane and out of plane, CHCH out of plane, >CC< out of plane modes, NMR chemical shifts δ(ppm of Hα, Hβ, CO, Cα and Cβ of these chalcones were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituents on the group frequencies are explained. Antibacterial, antifungal, antioxidant and insect antifeedant activities of these chalcones have been studied.

  4. Synthesis

    Directory of Open Access Journals (Sweden)

    Emel Pelit

    2016-05-01

    Full Text Available New optically active aminoalkylnaphthols were obtained by condensation of 2-naphthol, substituted aromatic and heteroaromatic aldehydes and (R-(+-1-phenylethylamine or (S-(−-1-phenylethylamine under conventional methods and ultrasonic irradiation. The enantiopure aminoalkylnaphthol derivatives were converted in ring-closure reaction with formaldehyde to the corresponding naphthoxazine derivatives.

  5. Synthesis of semiconductor polymers by inductive plasma

    International Nuclear Information System (INIS)

    Fernandez, G.; Cruz, G.; Olayo, M.G.; Morales, J.

    2003-01-01

    When carrying out the synthesis of semiconductor polymers by plasma it is important to consider the electric arrangement of the discharge since this it influences in the distribution of the energy of the particles in the reactor. The main electric arrangements in those that are developed the brightness discharges of radio frequency are resistive, capacitive and inductive. In the Laboratory of Materials processing by plasma of the ININ its have been worked different synthesis of polymers with resistive arrangements with good results. In this work the results of the synthesis and characterization of poly aniline and chlorate polyethylene by inductive plasma are presented. (Author)

  6. Sonochemical Synthesis of Cobalt Ferrite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Partha P. Goswami

    2013-01-01

    Full Text Available Cobalt ferrite being a hard magnetic material with high coercivity and moderate magnetization has found wide-spread applications. In this paper, we have reported the sonochemical synthesis of cobalt ferrite nanoparticles using metal acetate precursors. The ferrite synthesis occurs in three steps (hydrolysis of acetates, oxidation of hydroxides, and in situ microcalcination of metal oxides that are facilitated by physical and chemical effects of cavitation bubbles. The physical and magnetic properties of the ferrite nano-particles thus synthesized have been found to be comparable with those reported in the literature using other synthesis techniques.

  7. Thermodynamics of carbothermic synthesis of actinide mononitrides

    International Nuclear Information System (INIS)

    Ogawa, T.; Shirasu, Y.; Minato, K.; Serizawa, H.

    1997-01-01

    Carbothermic synthesis will be further applied to the fabrication of nitride fuels containing minor actinides (MA) such as neptunium, americium and curium. A thorough understanding of the carbothermic synthesis of UN will be beneficial in the development of the MA-containing fuels. Thermodynamic analysis was carried out for conditions of practical interest in order to better understand the recent fabrication experiences. Two types of solution phases, oxynitride and carbonitride phases, were taken into account. The Pu-N-O ternary isotherm was assessed for the modelling of M(C, N, O). With the understanding of the UN synthesis, the fabrication problems of Am-containing nitrides are discussed. (orig.)

  8. Synthesis of plant hormones labelled by tritium

    International Nuclear Information System (INIS)

    Sidorov, G.V.; Myasoedov, N.F.

    1999-01-01

    Reaction of solid-phase catalytic hydrogenation, isotopic exchange with enriched tritium water, catalytic heterogenous isotopic exchange with gaseous tritium, hydrogenolysis as applied to synthesis of plants labelled by tritium were studied. Auxins, cytokinins, gibberellins, fusicoccins - representatives of the basic hormones of plants - were objects of investigations. In dependence on synthesis method compounds labelled by tritium were prepared with molar radioactivity from 5 up to 155 Ci/mmol. Order of universal approaches to synthesis of plant hormones labelled by tritium was formulated [ru

  9. Total synthesis of (±)-antroquinonol d.

    Science.gov (United States)

    Sulake, Rohidas S; Jiang, Yan-Feng; Lin, Hsiao-Han; Chen, Chinpiao

    2014-11-21

    Total synthesis of (±)-antroquinonol D, which is isolated from very expensive and rarely found Antrodia camphorata and which has potential anticancer properties, was achieved from 4-methoxyphenol. In addition, a Michael addition to dimethoxy cyclohexadienones was studied. The main step involved chelation and substrate-controlled diastereoselective reduction of cyclohexenone and lactonization. Lactone synthesis facilitated the diastereoselective reduction of ketone, which help control the desired stereochemistry at the crucial stereogenic center in the natural product. Other key reactions in the synthesis involved a Michael addition of dimethyl malonate on cyclohexadienone, dihydroxylation, and Wittig olefination. A sesquiterpene side chain was synthesized through coupling with geranyl phenyl sulfide and Bouveault-Blanc reduction.

  10. Convenient synthesis of deuterated aluminium hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Pawelke, Roland H.; Felderhoff, Michael; Weidenthaler, Claudia [Max-Planck-Institut fuer Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Muelheim an der Ruhr (Germany); Schueth, Ferdi [Max-Planck-Institut fuer Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Muelheim an der Ruhr (Germany)], E-mail: schueth@mpi-muelheim.mpg.de

    2008-09-15

    We describe the ball-milling synthesis of alkali metal deuterides from commercial lithium aluminium deuteride. This reaction principle was exemplified by the mechanochemical synthesis of NaAlD{sub 4} and KAlD{sub 4}. NaAlD{sub 4} was prepared on the multi-gram scale by this procedure and purified by standard wet-chemical separation. Pure NaAlD{sub 4} was obtained and used for the synthesis of Ca(AlD{sub 4}){sub 2}. The formation of all products was verified by X-ray diffraction.

  11. Green chemistry oriented organic synthesis in water.

    Science.gov (United States)

    Simon, Marc-Olivier; Li, Chao-Jun

    2012-02-21

    The use of water as solvent features many benefits such as improving reactivities and selectivities, simplifying the workup procedures, enabling the recycling of the catalyst and allowing mild reaction conditions and protecting-group free synthesis in addition to being benign itself. In addition, exploring organic chemistry in water can lead to uncommon reactivities and selectivities complementing the organic chemists' synthetic toolbox in organic solvents. Studying chemistry in water also allows insight to be gained into Nature's way of chemical synthesis. However, using water as solvent is not always green. This tutorial review briefly discusses organic synthesis in water with a Green Chemistry perspective.

  12. Combinatorial synthesis of natural products

    DEFF Research Database (Denmark)

    Nielsen, John

    2002-01-01

    Combinatorial syntheses allow production of compound libraries in an expeditious and organized manner immediately applicable for high-throughput screening. Natural products possess a pedigree to justify quality and appreciation in drug discovery and development. Currently, we are seeing a rapid...... increase in application of natural products in combinatorial chemistry and vice versa. The therapeutic areas of infectious disease and oncology still dominate but many new areas are emerging. Several complex natural products have now been synthesised by solid-phase methods and have created the foundation...... for preparation of combinatorial libraries. In other examples, natural products or intermediates have served as building blocks or scaffolds in the synthesis of complex natural products, bioactive analogues or designed hybrid molecules. Finally, structural motifs from the biologically active parent molecule have...

  13. Synthesis and characterization of Taurine

    Directory of Open Access Journals (Sweden)

    B Bayarmaa

    2014-10-01

    Full Text Available Have been obtained 2-aminoethanesulfonic acid (taurine from ethanolamine, sulfuric acid and sodium sulfite during the synthesis in laboratory condition. The process involves two steps of reactions, the first was esterification of ethanolamine with sulfuric acid to produce the intermediate product of 2-aminoethyl ester which than was extended to the second step by sulfonation with sodium sulfite to produce 2-aminoethanesulfonic acid. Resulting product was analyzed using 1H-NMR, IR, FAB-MS analysis and examined purity characterizations of the synthesized products. DOI: http://dx.doi.org/10.5564/mjc.v14i0.200 Mongolian Journal of Chemistry 14 (40, 2013, p57-60

  14. Combustion synthesis continuous flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, G.D.; Chick, L.A.; Kurosky, R.P.

    1998-01-06

    The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor. 10 figs.

  15. Combustion synthesis continuous flow reactor

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, Gary D. (Richland, WA); Chick, Lawrence A. (West Richland, WA); Kurosky, Randal P. (Maple Valley, WA)

    1998-01-01

    The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor.

  16. Electrochemical synthesis of multisegmented nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Kuan-Ying; Ng, Inn-Khuan; Saidin, Nur Ubaidah [Malaysian Nuclear Agency, Bangi, 43000 Kajang (Malaysia)

    2012-11-27

    Electrochemical deposition has emerged as a promising route for nanostructure fabrication in recent years due to the many inherent advantages it possesses. This study focuses on the synthesis of high-aspect-ratio multisegmented Au/Ni nanowires using template-directed sequential electrochemical deposition techniques. By selectively removing the Ni segments in the nanowires, high-yield of pure gold nanorods of predetermined lengths was obtained. Alternatively, the sacrificial Ni segments in the nanowires can be galvanically displaced with Bi and Te to form barbells structures with Bi{sub x}Te{sub y} nanotubes attached to neighbouring gold segments. Detailed studies on the nanostructures obtained were carried out using various microscopy, diffraction and probebased techniques for structural, morphological and chemical characterizations.

  17. Total synthesis of mycalamide A.

    Science.gov (United States)

    Sohn, Jeong-Hun; Waizumi, Nobuaki; Zhong, H Marlon; Rawal, Viresh H

    2005-05-25

    This communication describes a concise and efficient total synthesis of mycalamide A by the convergent coupling of pederic acid unit with the mycalamine unit. The left-half, (+)-7-benzoylpederic acid, was synthesized from (2R,3R)-3-methylpent-4-en-2-ol in seven steps and 34.6% overall yield through a route that features a one-step Pd(II)-catalyzed tandem Wacker/Heck cyclization reaction to prepare the tetrahydropyran ring system. The right-half, the mycalamine unit, was synthesized in 21 steps and 10.5% overall yield from diethyl d-tartrate. Effective, stereoselective methods were developed for the assembly of the two parts to yield either mycalamide A or C(10)-epi-mycalamide A.

  18. Triboluminescence theory, synthesis, and application

    CERN Document Server

    Okoli, Okenwa; Fontenot, Ross; Hollerman, William

    2016-01-01

    This book expounds on progress made over the last 35 years in the theory, synthesis, and application of triboluminescence for creating smart structures. It presents in detail the research into utilization of the triboluminescent properties of certain crystals as new sensor systems for smart engineering structures, as well as triboluminescence-based sensor systems that have the potential to enable wireless, in-situ, real time and distributed (WIRD) structural health monitoring of composite structures. The sensor component of any structural health monitoring (SHM) technology — measures the effects of the external load/event and provides the necessary inputs for appropriate preventive/corrective action to be taken in a smart structure — sits at the heart of such a system. This volume explores advances in materials properties and structural behavior underlying creation of smart composite structures and sensor systems for structural health monitoring of critical engineering structures, such as bridges, aircraf...

  19. Fluid Mechanics Optimising Organic Synthesis

    Science.gov (United States)

    Leivadarou, Evgenia; Dalziel, Stuart

    2015-11-01

    The Vortex Fluidic Device (VFD) is a new ``green'' approach in the synthesis of organic chemicals with many industrial applications in biodiesel generation, cosmetics, protein folding and pharmaceutical production. The VFD is a rapidly rotating tube that can operate with a jet feeding drops of liquid reactants to the base of the tube. The aim of this project is to explain the fluid mechanics of the VFD that influence the rate of reactions. The reaction rate is intimately related to the intense shearing that promotes collision between reactant molecules. In the VFD, the highest shears are found at the bottom of the tube in the Rayleigh and the Ekman layer and at the walls in the Stewardson layers. As a step towards optimising the performance of the VFD we present experiments conducted in order to establish the minimum drop volume and maximum rotation rate for maximum axisymmetric spreading without fingering instability. PhD candidate, Department of Applied Mathematics and Theoretical Physics.

  20. Synthesis of B6 vitamin

    Directory of Open Access Journals (Sweden)

    Vučijak Nevena Ž.

    2009-01-01

    Full Text Available The importance of vitamin B6 has been known since its discovery in the 1940's. Chemical tests, elestrometric titration determinations, and absorption spectrum studies showed that this vitamin exists in three major chemical forms: pyridoxine (an alcohol, pyridoxal (an aldehyde, and pyridoxamine (a primary amine. Vitamin B6 is needed for more than 100 enzymes involved in protein metabolism, and it is assumed that this vitamin is cofactor of metabolic processes more important than any other substance. A deficiency of vitamin B6 in the human diet leads to severe disorders. Vitamin B6 is necessary for the proper function of the immune and nervous system, and helps the body convert protein to energy. This paper describes the history, properties and applications of vitamin B6, elucidation of chemical structure, and different procedures for synthesis of pyridoxine and pyridoxamine.

  1. Solution synthesis of germanium nanocrystals

    Science.gov (United States)

    Gerung, Henry [Albuquerque, NM; Boyle, Timothy J [Kensington, MD; Bunge, Scott D [Cuyahoga Falls, OH

    2009-09-22

    A method for providing a route for the synthesis of a Ge(0) nanometer-sized material from. A Ge(II) precursor is dissolved in a ligand heated to a temperature, generally between approximately 100.degree. C. and 400.degree. C., sufficient to thermally reduce the Ge(II) to Ge(0), where the ligand is a compound that can bond to the surface of the germanium nanomaterials to subsequently prevent agglomeration of the nanomaterials. The ligand encapsulates the surface of the Ge(0) material to prevent agglomeration. The resulting solution is cooled for handling, with the cooling characteristics useful in controlling the size and size distribution of the Ge(0) materials. The characteristics of the Ge(II) precursor determine whether the Ge(0) materials that result will be nanocrystals or nanowires.

  2. Silica Aerogel: Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    Jyoti L. Gurav

    2010-01-01

    Full Text Available Silica aerogels have drawn a lot of interest both in science and technology because of their low bulk density (up to 95% of their volume is air, hydrophobicity, low thermal conductivity, high surface area, and optical transparency. Aerogels are synthesized from molecular precursors by sol-gel processing. Special drying techniques must be applied to replace the pore liquid with air while maintaining the solid network. Supercritical drying is most common; however, recently developed methods allow removal of the liquid at atmospheric pressure after chemical modification of the inner surface of the gels, leaving only a porous silica network filled with air. Therefore, by considering the surprising properties of aerogels, the present review addresses synthesis of silica aerogels by the sol-gel method, as well as drying techniques and applications in current industrial development and scientific research.

  3. Control synthesis of switched systems

    CERN Document Server

    Zhao, Xudong; Niu, Ben; Wu, Tingting

    2017-01-01

    This book offers its readers a detailed overview of the synthesis of switched systems, with a focus on switching stabilization and intelligent control. The problems investigated are not only previously unsolved theoretically but also of practical importance in many applications: voltage conversion, naval piloting and navigation and robotics, for example. The book considers general switched-system models and provides more efficient design methods to bring together theory and application more closely than was possible using classical methods. It also discusses several different classes of switched systems. For general switched linear systems and switched nonlinear systems comprising unstable subsystems, it introduces novel ideas such as invariant subspace theory and the time-scheduled Lyapunov function method of designing switching signals to stabilize the underlying systems. For some typical switched nonlinear systems affected by various complex dynamics, the book proposes novel design approaches based on inte...

  4. Synthesis gas method and apparatus

    Science.gov (United States)

    Kelly, Sean M.; Kromer, Brian R.; Litwin, Michael M.; Rosen, Lee J.; Christie, Gervase Maxwell; Wilson, Jamie R.; Kosowski, Lawrence W.; Robinson, Charles

    2013-01-08

    A method and apparatus for producing a synthesis gas product having one or more oxygen transport membrane elements thermally coupled to one or more catalytic reactors such that heat generated from the oxygen transport membrane element supplies endothermic heating requirements for steam methane reforming reactions occurring within the catalytic reactor through radiation and convention heat transfer. A hydrogen containing stream containing no more than 20 percent methane is combusted within the oxygen transport membrane element to produce the heat and a heated combustion product stream. The heated combustion product stream is combined with a reactant stream to form a combined stream that is subjected to the reforming within the catalytic reactor. The apparatus may include modules in which tubular membrane elements surround a central reactor tube.

  5. SPARSE FARADAY ROTATION MEASURE SYNTHESIS

    International Nuclear Information System (INIS)

    Andrecut, M.; Stil, J. M.; Taylor, A. R.

    2012-01-01

    Faraday rotation measure synthesis is a method for analyzing multichannel polarized radio emissions, and it has emerged as an important tool in the study of Galactic and extragalactic magnetic fields. The method requires the recovery of the Faraday dispersion function from measurements restricted to limited wavelength ranges, which is an ill-conditioned deconvolution problem. Here, we discuss a recovery method that assumes a sparse approximation of the Faraday dispersion function in an overcomplete dictionary of functions. We discuss the general case when both thin and thick components are included in the model, and we present the implementation of a greedy deconvolution algorithm. We illustrate the method with several numerical simulations that emphasize the effect of the covered range and sampling resolution in the Faraday depth space, and the effect of noise on the observed data.

  6. Synthesis of nanoparticles using ethanol

    Science.gov (United States)

    Wang, Jia Xu

    2017-01-24

    The present disclosure relates to methods for producing nanoparticles. The nanoparticles may be made using ethanol as the solvent and the reductant to fabricate noble-metal nanoparticles with a narrow particle size distributions, and to coat a thin metal shell on other metal cores. With or without carbon supports, particle size is controlled by fine-tuning the reduction power of ethanol, by adjusting the temperature, and by adding an alkaline solution during syntheses. The thickness of the added or coated metal shell can be varied easily from sub-monolayer to multiple layers in a seed-mediated growth process. The entire synthesis of designed core-shell catalysts can be completed using metal salts as the precursors with more than 98% yield; and, substantially no cleaning processes are necessary apart from simple rinsing. Accordingly, this method is considered to be a "green" chemistry method.

  7. Synthesis and characterization of tetraethylammonium tetrachloro ...

    Indian Academy of Sciences (India)

    Unknown

    Synthesis and characterization of tetraethylammonium tetrachloro- cobaltate crystals. M A KANDHASWAMY and V SRINIVASAN*. Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, India. MS received 7 February 2000; revised 27 December 2001. Abstract.

  8. Synthesis, Spectroscopic and Pharmacological Studies of Bivalent ...

    African Journals Online (AJOL)

    Synthesis, Spectroscopic and Pharmacological Studies of Bivalent Copper, Zinc and Mercury Complexes of Thiourea. ... All the metal complexes were characterized by elemental chemical analysis, molar conductance, magnetic susceptibility measurements and IR spectroscopy. Cu(II) complexes were additionally ...

  9. Biological synthesis and characterization of silver nanoparticles ...

    Indian Academy of Sciences (India)

    Biological synthesis and characterization of silver nanoparticles using. Eclipta alba leaf extract and evaluation of its cytotoxic and antimicrobial potential. PARAMASIVAM PREMASUDHA1, MUDILI VENKATARAMANA2,∗, MARRIAPPAN ABIRAMI3,. PERIYASAMY VANATHI4, KADIRVELU KRISHNA2 and RAMASAMY ...

  10. Iterative perceptual learning for social behavior synthesis

    NARCIS (Netherlands)

    de Kok, I.A.; Poppe, Ronald Walter; Heylen, Dirk K.J.

    We introduce Iterative Perceptual Learning (IPL), a novel approach to learn computational models for social behavior synthesis from corpora of human–human interactions. IPL combines perceptual evaluation with iterative model refinement. Human observers rate the appropriateness of synthesized

  11. Iterative Perceptual Learning for Social Behavior Synthesis

    NARCIS (Netherlands)

    de Kok, I.A.; Poppe, Ronald Walter; Heylen, Dirk K.J.

    We introduce Iterative Perceptual Learning (IPL), a novel approach for learning computational models for social behavior synthesis from corpora of human-human interactions. The IPL approach combines perceptual evaluation with iterative model refinement. Human observers rate the appropriateness of

  12. An introduction to statistical parametric speech synthesis

    Indian Academy of Sciences (India)

    - like models, has become competitive with established concatenative techniques over the last few years. This paper offers a non-mathematical introduction to this method of speech synthesis. It is intended to be complementary to the wide ...

  13. Synthesis of dehydrobenzoannulenes with pyrene core

    Indian Academy of Sciences (India)

    -diethynylpyrene and. 1,3,6,8-tetraethynylpyrene as building blocks is reported. A sequence involving Sonogashira coupling, Corey–. Fuchs reaction and oxidative coupling (Eglinton coupling) is used for the synthesis of pyrene-based dehy-.

  14. Combustion synthesis of bulk nanocrystalline iron alloys

    Directory of Open Access Journals (Sweden)

    Licai Fu

    2016-02-01

    Full Text Available The controlled synthesis of large-scale nanocrystalline metals and alloys with predefined architecture is in general a big challenge, and making full use of these materials in applications still requires greatly effort. The combustion synthesis technique has been successfully extended to prepare large-scale nanocrystalline metals and alloys, especially iron alloy, such as FeC, FeNi, FeCu, FeSi, FeB, FeAl, FeSiAl, FeSiB, and the microstructure can be designed. In this issue, recent progress on the synthesis of nanocrystalline metals and alloys prepared by combustion synthesis technique are reviewed. Then, the mechanical and tribological properties of these materials with microstructure control are discussed.

  15. Allyl functionalized phosphinite and phosphonite ligands: Synthesis ...

    Indian Academy of Sciences (India)

    Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions. SINGAPPAGUDEM GOVINDARAJUa, GUDDEKOPPA S ANANTHNAGa, SUSMITA NAIKa,. SHAIKH M MOBINb and MARAVANJI S BALAKRISHNAa,∗. aPhosphorus Laboratory, Department of ...

  16. FUNCTIONALIZED CALIXSPHERANDS - SYNTHESIS AND PEPTIDE COUPLING

    NARCIS (Netherlands)

    BAKKER, WII; HAAS, M; DENHERTOG, HJ; VERBOOM, W; DEZEEUW, D; BRUINS, AP; REINHOUDT, DN

    1994-01-01

    Calixspherands, like 1, form kinetically stable complexes with alkali metal cations. For practical in vivo applications coupling of these complexes with carrier molecules is mandatory, Therefore, a general method for the synthesis of functionalized calixspherand 17 was developed starting from

  17. Polymer nanotube nanocomposites: synthesis, properties, and applications

    National Research Council Canada - National Science Library

    Mittal, Vikas

    2010-01-01

    ... in these commercially important areas of polymer technology. It sums up recent advances in nanotube composite synthesis technology, provides basic introduction to polymer nanotubes nanocomposite technology for the readers new to this field, provides valuable...

  18. Synthesis of asymmetrical multiantennary human milk oligosaccharides

    NARCIS (Netherlands)

    Prudden, Anthony R; Liu, Lin; Capicciotti, Chantelle J.; Wolfert, Margreet A; Wang, Shuo; Gao, Zhongwei; Meng, Lu; Moremen, Kelley W; Boons, Geert-Jan

    2017-01-01

    Despite mammalian glycans typically having highly complex asymmetrical multiantennary architectures, chemical and chemoenzymatic synthesis has almost exclusively focused on the preparation of simpler symmetrical structures. This deficiency hampers investigations into the biology of glycan-binding

  19. Synthesis and biological activities of substituted N ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... The present study describes the synthesis, antioxidant and antibacterial activities of substituted N'- benzoylhydrazone derivatives, to ... addition, the dramatically rising prevalence of multidrug- resistant microbial infections has ...... extract of Chinese green tea (Camellia sinensis) on Listeria monocytogenes.

  20. Copper catalysed synthesis of indolylquinazolinone alkaloid ...

    Indian Academy of Sciences (India)

    We describe the total synthesis of indolylquinazolinone alkaloid bouchardatine and some of the quinazolinone derivatives. The aerobic oxidation induced by copper(I) bromide, followed by Vilsmeier-Haack formylation gives the natural product bouchardatine alkaloid in good yield.

  1. Non-covalent synthesis of organic nanostructures

    NARCIS (Netherlands)

    Prins, L.J.; Timmerman, P.; Reinhoudt, David

    1998-01-01

    This review describes the synthesis, characterization and functionalization of hydrogen bonded, box-like assemblies. These assemblies are formed upon mixing bismelamine calix[4]arenes with a complementary barbiturate in apolar solvents. Various techniques for the characterization have been used,

  2. SHORT COMMUNICATION CONVENIENT AND MILD SYNTHESIS ...

    African Journals Online (AJOL)

    Preferred Customer

    , Synthesis. INTRODUCTION. Schiff bases are reagents, which are becoming increasingly important in the pharmaceutical, dye and plastic industries as well as for liquid-crystal technology and mechanistic investigations of the drugs used in ...

  3. Synthesis algorithm of VLSI multipliers for ASIC

    Science.gov (United States)

    Chua, O. H.; Eldin, A. G.

    1993-01-01

    Multipliers are critical sub-blocks in ASIC design, especially for digital signal processing and communications applications. A flexible multiplier synthesis tool is developed which is capable of generating multiplier blocks for word size in the range of 4 to 256 bits. A comparison of existing multiplier algorithms is made in terms of speed, silicon area, and suitability for automated synthesis and verification of its VLSI implementation. The algorithm divides the range of supported word sizes into sub-ranges and provides each sub-range with a specific multiplier architecture for optimal speed and area. The algorithm of the synthesis tool and the multiplier architectures are presented. Circuit implementation and the automated synthesis methodology are discussed.

  4. Diagnosis, Synthesis and Analysis of Probabilistic Models

    NARCIS (Netherlands)

    Han, Tingting

    2009-01-01

    This dissertation considers three important aspects of model checking Markov models: diagnosis — generating counterexamples, synthesis — providing valid parameter values and analysis — verifying linear real-time properties. The three aspects are relatively independent while all contribute to

  5. Synthesis methodology and applied heterocyclic chemistry

    International Nuclear Information System (INIS)

    Suzenet, F.

    2007-11-01

    Among the researches activities presented in this work, is described the synthesis of extracting molecules for the reprocessing of nuclear wastes. The use of some elaborated ligands for the detection of metallic cations has been considered. (O.M.)

  6. Albumin synthesis in protein energy malnutrition

    International Nuclear Information System (INIS)

    Duggan, C.; Hardy, S.; Kleinman, R.E.; Lembcke, J.; Young, V.E.

    1994-01-01

    The dietary treatment of protein-energy malnutrition (PEM) has been designed on an empirical basis, with outcomes for successful management including body weight gain and resolution of apathy. We propose using the measurements of protein synthesis as a more objective measure of renourishment. We will therefore randomize a group of malnourished children (weigh-for-height Z score 13 C-leucine and serial measurements of 13 C-enrichment of albumin. Isotope infusions will be performed on days one and three, following a standard three hour fast. Since albumin synthesis is reduced under the influence of cytokines which mediate the inflammatory response, results will be stratified according to the presence or absence of clinically apparent infections. We hypothesize that the provision of added dietary protein will optimize albumin synthesis rates in PEM as well as attenuate the reduction in albumin synthesis seen in the presence of infections. (author). 20 refs

  7. Anthrax carbohydrates, synthesis and uses thereof

    Science.gov (United States)

    Carlson, Russell W.; Boons, Geert-Jan; Quinn, Conrad; Vasan, Mahalakshmi; Wolfert, Margreet A.; Choudhury, Biswa; Kannenberg, Elmar; Leoff, Christine; Mehta, Alok; Saile, Elke; Rauvolfova, Jana; Wilkins, Patricia; Harvey, Alex J.

    2013-04-16

    The present invention presents the isolation, characterization and synthesis of oligosaccharides of Bacillus anthracis. Also presented are antibodies that bind to such saccharide moieties and various methods of use for such saccharide moieties and antibodies.

  8. Solving fault diagnosis problems linear synthesis techniques

    CERN Document Server

    Varga, Andreas

    2017-01-01

    This book addresses fault detection and isolation topics from a computational perspective. Unlike most existing literature, it bridges the gap between the existing well-developed theoretical results and the realm of reliable computational synthesis procedures. The model-based approach to fault detection and diagnosis has been the subject of ongoing research for the past few decades. While the theoretical aspects of fault diagnosis on the basis of linear models are well understood, most of the computational methods proposed for the synthesis of fault detection and isolation filters are not satisfactory from a numerical standpoint. Several features make this book unique in the fault detection literature: Solution of standard synthesis problems in the most general setting, for both continuous- and discrete-time systems, regardless of whether they are proper or not; consequently, the proposed synthesis procedures can solve a specific problem whenever a solution exists Emphasis on the best numerical algorithms to ...

  9. Microwave chemistry for inorganic nanomaterials synthesis.

    Science.gov (United States)

    Bilecka, Idalia; Niederberger, Markus

    2010-08-01

    This Feature Article gives an overview of microwave-assisted liquid phase routes to inorganic nanomaterials. Whereas microwave chemistry is a well-established technique in organic synthesis, its use in inorganic nanomaterials' synthesis is still at the beginning and far away from having reached its full potential. However, the rapidly growing number of publications in this field suggests that microwave chemistry will play an outstanding role in the broad field of Nanoscience and Nanotechnology. This article is not meant to give an exhaustive overview of all nanomaterials synthesized by the microwave technique, but to discuss the new opportunities that arise as a result of the unique features of microwave chemistry. Principles, advantages and limitations of microwave chemistry are introduced, its application in the synthesis of different classes of functional nanomaterials is discussed, and finally expected benefits for nanomaterials' synthesis are elaborated.

  10. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael

    2006-01-01

    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  11. Synthesis, mechanical, thermal and chemical properties of ...

    Indian Academy of Sciences (India)

    Unknown

    Synthesis, mechanical, thermal and chemical properties of polyurethanes based on cardanol. C V MYTHILI, A MALAR RETNA and S GOPALAKRISHNAN*. Department of Chemistry, Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli 627 012, India. MS received 28 August 2003; revised 19 February 2004.

  12. Microbiological synthesis of methyl ethyl ketone

    Directory of Open Access Journals (Sweden)

    Astashkina Anna

    2016-01-01

    Full Text Available Optimal conditions for the microbiological synthesis of methyl ethyl ketone (MEK on the mineral medium with butanol-1, butanol-2, 2-methylpropanol-2 by hydrocarbon-oxidizing bacteria Pseudomonas spp. were chosen. Optimal conditions for microbiological synthesis are liquid mineral Adkins’ medium containing 3% (vol. of the substrate, stirring speed – 80-100 rev/min, temperature – 37° C, and synthesis time 24-48 hours. The specific growth rate and time of culture generation during the microbial synthesis were determined. It was found that methyl ethyl ketone is formed in the reaction mixture after 8, 48 and 72 hours when using 2-methylpropanol-2, butanol-2, butanol-1 as substrates, respectively. Maximum methyl ethyl ketone yield in the reaction mixture is observed after 12 hours in the case of using 2-methylpropanol-2 as a carbon source and accounts for 10%.

  13. Synthesis, characterization and ion exchange properties of ...

    Indian Academy of Sciences (India)

    –1 dry exchanger, respectively. The material ... been found to have better properties than the simple salts of metals. The selectivity may be enhanced ... capacity and higher stability at elevated temperature. This paper deals with the synthesis, ...

  14. Iridium catalysed synthesis of piperazines from diols

    DEFF Research Database (Denmark)

    Nordstrøm, Lars Ulrik Rubæk; Madsen, Robert

    2007-01-01

    A green and atom-economical method has been developed for the synthesis of piperazines by cyclocondensation of diols and amines in aqueous media in the presence of a catalytic amount of [Cp*IrCl2]2....

  15. Synthesis, antioxidant and antimicrobial evaluation of thiazolidinone ...

    Indian Academy of Sciences (India)

    Vol. 124, No. 2, March 2012, pp. 469–481. c Indian Academy of Sciences. Synthesis, antioxidant and antimicrobial evaluation of thiazolidinone, azetidinone encompassing indolylthienopyrimidines. ANAND RAGHUNATH SAUNDANE. ∗. , MANJUNATHA YARLAKATTI,. PRABHAKER WALMIK and VIJAYKUMAR KATKAR.

  16. Variational inference & deep learning : A new synthesis

    NARCIS (Netherlands)

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  17. Surface active monomers synthesis, properties, and application

    CERN Document Server

    Borzenkov, Mykola

    2014-01-01

    This brief includes information on the background?of and development of synthesis of various types of surface active monomers. The authors explain the importance of utilization of surface active monomers for creation of surface active polymers? and the various biomedical applications of such compounds . This brief introduces techniques for the synthesis of novel types of surface active monomers, their colloidal and polymerizable properties and application for needs of medicine and biology.

  18. Embedded System Synthesis under Memory Constraints

    DEFF Research Database (Denmark)

    Madsen, Jan; Bjørn-Jørgensen, Peter

    1999-01-01

    This paper presents a genetic algorithm to solve the system synthesis problem of mapping a time constrained single-rate system specification onto a given heterogeneous architecture which may contain irregular interconnection structures. The synthesis is performed under memory constraints, that is......, the algorithm takes into account the memory size of processors and the size of interface buffers of communication links, and in particular the complicated interplay of these. The presented algorithm is implemented as part of the LY-COS cosynthesis system....

  19. Synthesis of disk-on-rod antennas

    Science.gov (United States)

    Dubrovka, F. F.; Lenivenko, V. A.

    1993-05-01

    The analysis and synthesis of disk-on-rod antennas (DORAs) with canonical and stepwise disk shapes are considered. A comparison of theoretical and experimental results shows that mathematical models and software developed by solving the appropriate boundary value problems can be used for the design of optimal DORAs. A broadband centimeter-wave DORA is considered as an example of the application of the proposed method for the constructive synthesis of DORAs using multicriterial optimization.

  20. Protein synthesis in the growing rat lung

    International Nuclear Information System (INIS)

    Kelley, J.; Chrin, L.

    1986-01-01

    Developmental control of protein synthesis in the postnatal growth of the lung has not been systematically studied. In male Fischer 344 rats, lung growth continues linearly as a function of body weight (from 75 to 450 g body weight). To study total protein synthesis in lungs of growing rats, we used the technique of constant intravenous infusion of tritiated leucine, an essential amino acid. Lungs of sacrificed animals were used to determine the leucine incorporation rate into newly synthesized protein. The specific radioactivity of the leucine associated with tRNA extracted from the same lungs served as an absolute index of the precursor leucine pool used for lung protein synthesis. On the basis of these measurements, we were able to calculate the fractional synthesis rate (the proportion of total protein destroyed and replaced each day) of pulmonary proteins for each rat. Under the conditions of isotope infusion, leucyl-tRNA very rapidly equilibrates with free leucine of the plasma and of the extracellular space of the lung. Infusions lasting 30 minutes or less yielded linear rates of protein synthesis without evidence of contamination of lung proteins by newly labeled intravascular albumin. The fractional synthesis rate is considerably higher in juvenile animals (55% per day) than in adult rats (20% per day). After approximately 12 weeks of age, the fractional synthesis rate remains extremely constant in spite of continued slow growth of the lung. It is apparent from these data that in both young and adult rats the bulk of total protein synthesis is devoted to rapidly turning over proteins and that less than 4 percent of newly made protein is committed to tissue growth

  1. Organosilicon and organogermanium peroxides: synthesis and reactions

    International Nuclear Information System (INIS)

    Terent'ev, Alexander O; Platonov, Maksim M; Levitsky, D O; Dembitsky, V M

    2011-01-01

    The methods of synthesis and reactions of organosilicon and organogermanium peroxides are surveyed. The emphasis is placed on the studies reported in the last two decades, because in this period, the use of singlet oxygen and the Isayama–Mukaiyama reaction for the synthesis of organosilicon peroxides started. The use of these compounds in the development of antiparasitic agents is considered. The bibliography includes 220 references.

  2. Hypoxia. 3. Hypoxia and neurotransmitter synthesis

    OpenAIRE

    Kumar, Ganesh K.

    2011-01-01

    Central and peripheral neurons as well as neuroendocrine cells express a variety of neurotransmitters/modulators that play critical roles in regulation of physiological systems. The synthesis of several neurotransmitters/modulators is regulated by O2-requiring rate-limiting enzymes. Consequently, hypoxia resulting from perturbations in O2 homeostasis can affect neuronal functions by altering neurotransmitter synthesis. Two broad categories of hypoxia are frequently encountered: continuous hyp...

  3. ANALYTICAL SYNTHESIS OF CHEMICAL REACTOR CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    Alexander Labutin

    2017-02-01

    Full Text Available The problem of the analytical synthesis of the synergetic control system of chemical reactor for the realization of a complex series-parallel exothermal reaction has been solved. The synthesis of control principles is performed using the analytical design method of aggregated regulators. Synthesized nonlinear control system solves the problem of stabilization of the concentration of target component at the exit of reactor and also enables one to automatically transfer to new production using the equipment.

  4. Synthesis of Polyfunctionalized 4H-Pyrans

    Directory of Open Access Journals (Sweden)

    Manisha Bihani

    2013-01-01

    Full Text Available Amberlyst A21 catalyzed one-pot three-component coupling of aldehyde and malononitrile with active methylene compounds such as acetylacetone and ethyl acetoacetate for the synthesis of pharmaceutically important polyfunctionalized 4H-pyrans has been reported. Simple experimental procedure, no chromatographic purification, no hazardous organic solvents, easy recovery and reusability of the catalyst, and room temperature reaction conditions are some of the highlights of this protocol for the synthesis of pharmaceutically relevant focused libraries.

  5. An improved pattern synthesis algorithm based on metric modes

    Science.gov (United States)

    Tan, Yongqian; Zeng, Fanju; Zhang, Song; Yang, Yongliang

    2017-08-01

    Based on the principle of texture image synthesis of block splicing, the application of texture synthesis algorithm in pattern synthesis is studied. Through the study of the characteristics of texture image and texture pattern, it is found that texture is a special image with both localization and stability, and the pattern is a kind of whole structure with stronger structure. Texture synthesis algorithm in the more texture image synthesis, can achieve a more satisfactory results, but the synthesis of the pattern cannot achieve better synthesis results. In this paper, through the study of the characteristics of the pattern, on the basis of the texture synthesis algorithm, by improving the measurement method, when judging the similarity of two matching blocks, while the color and gradient of the image block as the two matching blocks are similar between the important parameters. Experiments show that the improved algorithm can achieve better synthesis effect when synthesizing most of the patterns.

  6. Histidine as a catalyst in organic synthesis: A facile in situ synthesis ...

    Indian Academy of Sciences (India)

    Unknown

    Nitrones are versatile synthetic intermediates in organic synthesis 1–8. Some nitrones are used for trapping and identification of reactive free radicals 9, particularly in biomedical research 10. They are also used in the synthesis of many nitrogen-containing biologically active compounds 11,12. Recently, we synthesized ...

  7. Biocatalyzed Regioselective Synthesis in Undergraduate Organic Laboratories: Multistep Synthesis of 2-Arachidonoylglycerol

    Science.gov (United States)

    Johnston, Meghan R.; Makriyannis, Alexandros; Whitten, Kyle M.; Drew, Olivia C.; Best, Fiona A.

    2016-01-01

    In order to introduce the concepts of biocatalysis and its utility in synthesis to organic chemistry students, a multistep synthesis of endogenous cannabinergic ligand 2-arachidonoylglycerol (2-AG) was tailored for use as a laboratory exercise. Over four weeks, students successfully produced 2-AG, purifying and characterizing products at each…

  8. Histidine as a catalyst in organic synthesis: A facile in situ synthesis ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 4. Histidine as a catalyst in organic synthesis: A facile in situ synthesis of , N-diarylnitrones. H Mallesha K R Ravi Kumar B K Vishu Kumar K Mantelingu K S Rangappa. Organic Volume 113 Issue 4 August 2001 pp 291-296 ...

  9. Synthesis of polyaryl rigid-core carbosilane dendrimers for supported organic synthesis

    NARCIS (Netherlands)

    Wander, M.; Hausoul, P.J.C.; Sliedregt, L.A.J.M.; van Steen, B.J.; van Koten, G.; Klein Gebbink, R.J.M.

    2009-01-01

    Carbosilane dendrimers can be used as soluble supports for organic synthesis, since their structure allows separation of excess reagents from the supported products, eventually yielding products of high purity and in high yield, as in solid-phase organic synthesis (SPOS). In previous studies often

  10. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A

    International Nuclear Information System (INIS)

    Mallinger, A.

    2008-11-01

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A

  11. Effect of hemodialysis on protein synthesis.

    Science.gov (United States)

    Löfberg, E; Essén, P; McNurlan, M; Wernerman, J; Garlick, P; Anderstam, B; Bergström, J; Alvestrand, A

    2000-10-01

    Earlier studies have shown that hemodialysis (HD) treatment stimulates net protein catabolism. Several factors associated with HD affect protein catabolism, such as an inflammatory effect due to blood-membrane contact and loss of amino acids and glucose into the dialysate. We have studied protein synthesis in skeletal muscle of healthy volunteers (n = 9) before and after a single heparin-free HD. Protein synthesis (PS) was studied, using 2 independent techniques: the incorporation of labeled 2H5-phenylalanine into muscle protein, which gives a quantitative measure of the fractional synthesis rate of muscle proteins, and the concentration and size distribution of ribosomes, which gives a qualitative estimate of protein synthesis. Furthermore, free amino acid concentrations were determined in muscle and plasma. The rate of PS, expressed as the fractional synthesis rate, decreased by 13% during HD (p muscle free amino acid concentrations were determined at four time points; before and after the phenylalanine incorporation period, before dialysis and before and after the second incorporation period after dialysis. Immediately after dialysis, there was a decrease in plasma asparagine, histidine, alanine, taurine, valine and tryptophane. In muscle, no changes occurred except for a slight increase in leucine after dialysis. In blood, the glucose concentration decreased and the total amount of glucose lost to the dialysate was 21 +/- 3.0 g. In summary, one single hemodialysis treatment decreases fractional protein synthesis rate in skeletal muscle. The results demonstrate substantial losses of amino acids and glucose to the dialysate and decreased amino acid concentrations in plasma, but only minimal changes in the intracellular amino acid concentrations in muscle, suggesting that the decreased PS is caused not by lack of amino acid precursors at the site of the synthesis activity, but by other mechanisms.

  12. Sustainable processes synthesis for renewable resources

    International Nuclear Information System (INIS)

    Halasz, L.; Povoden, G.; Narodoslawsky, M.

    2005-01-01

    Renewable resources pose special challenges to process synthesis. Due to decentral raw material generation, usually low transport densities and the perishable character of most renewable raw materials in combination with their time dependent availability, logistical questions as well as adaptation to regional agricultural structures are necessary. This calls for synthesis of structures not only of single processes but of the whole value chain attached to the utilisation of a certain resource. As most of the innovative technologies proposed to build on a renewable raw material base face stiff economic competition from fossil based processes, economic optimality of the value chain is crucial to their implementation. On top of this widening of the process definition for synthesis, many processes on the base of renewable resources apply technologies (like membrane separations, chromatographic purification steps, etc.) for which the heuristic knowledge is still slim. This reduces the choice of methods for process synthesis, mainly to methods based on combinatorial principles. The paper investigates applicability as well as impact on technology development of process synthesis for renewable raw material utilisation. It takes logistic considerations into account and applies process synthesis to the case study of the green biorefinery concept. The results show the great potential of process synthesis for technology development of renewable resource utilisation. Applied early in the development phase, it can point towards the most promising utilisation pathways, thus guiding the engineering work. On top of that, and even more important, it can help avoid costly development flops as it also clearly indicates 'blind alleys' that have to be avoided

  13. Ammonia Synthesis at Low Pressure.

    Science.gov (United States)

    Cussler, Edward; McCormick, Alon; Reese, Michael; Malmali, Mahdi

    2017-08-23

    Ammonia can be synthesized at low pressure by the use of an ammonia selective absorbent. The process can be driven with wind energy, available locally in areas requiring ammonia for synthetic fertilizer. Such wind energy is often called "stranded," because it is only available far from population centers where it can be directly used. In the proposed low pressure process, nitrogen is made from air using pressure swing absorption, and hydrogen is produced by electrolysis of water. While these gases can react at approximately 400 °C in the presence of a promoted conventional catalyst, the conversion is often limited by the reverse reaction, which makes this reaction only feasible at high pressures. This limitation can be removed by absorption on an ammine-like calcium or magnesium chloride. Such alkaline metal halides can effectively remove ammonia, thus suppressing the equilibrium constraints of the reaction. In the proposed absorption-enhanced ammonia synthesis process, the rate of reaction may then be controlled not by the chemical kinetics nor the absorption rates, but by the rate of the recycle of unreacted gases. The results compare favorably with ammonia made from a conventional small scale Haber-Bosch process.

  14. Mechanochemical synthesis of bismuth ferrite

    Directory of Open Access Journals (Sweden)

    Marinković-Stanojevića Z.

    2013-01-01

    Full Text Available A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld’s structure refinement method. The resulting lattice parameters, relative phase abundances, crystallite sizes and crystal lattice microstrains were determined as a function of milling time. Microstructural analysis showed a little difference in morphology of obtained powders. The primary particles, irregular in shape and smaller than 400 nm are observed clearly, although they have assembled together to form agglomerates with varying size and morphology. Dense BFO ceramics were prepared by conventional solid-state reaction at the temperature of 810ºC for 1h followed immediately by quenching process. [Projekat Ministarstva nauke Republike Srbije, br. III45007: Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processing

  15. Asymmetric catalysis in organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, S.D.; Click, D.R.; Grumbine, S.K.; Scott, B.L.; Watkins, J.G.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of the project was to prepare new catalyst systems, which would perform chemical reactions in an enantioselective manner so as to produce only one of the possible optical isomers of the product molecule. The authors have investigated the use of lanthanide metals bearing both diolate and Schiff-base ligands as catalysts for the enantioselective reduction of prochiral ketones to secondary alcohols. The ligands were prepared from cheap, readily available starting materials, and their synthesis was performed in a ''modular'' manner such that tailoring of specific groups within the ligand could be carried out without repeating the entire synthetic procedure. In addition, they have developed a new ligand system for Group IV and lanthanide-based olefin polymerization catalysts. The ligand system is easily prepared from readily available starting materials and offers the opportunity to rapidly prepare a wide range of closely related ligands that differ only in their substitution patterns at an aromatic ring. When attached to a metal center, the ligand system has the potential to carry out polymerization reactions in a stereocontrolled manner.

  16. De novo Synthesis of Monosaccharides

    Science.gov (United States)

    Vogel, Pierre; Robina, Inmaculada

    Recent approaches to asymmetric total synthesis of monosaccharides and derivatives are reviewed. They imply biochemical methods or chemical methods, or combinations of both. Aldoses, alditols, deoxysugars, aminodeoxymonosaccharides, and their analogues are considered, including aza- and thiosugars (with nitrogen and sulfur in the pyranose or furanose ring). Most common monosaccharides have three to six carbon-chains, but examples of long-chain and branched-chain carbohydrates will also be described. Organization of the review is based on the synthetic methodology rather than on the types of targeted sugar, starting with aldolase-catalyzed aldol reactions of achiral precursors, and the now popular amino-acid-catalyzed aldol and Mannich reactions. Chain elongations of small aldose derivatives with one, two, three, or four carbons remain very useful approaches as they allow one to reach a large structural and stereochemical diversity. Other methods apply Diels-Alder or hetero-Diels-Alder additions. Enantiomerically pure monosaccharides have been derived from achiral alkene, diene, and triene derivatives. Almost any targeted natural or non-natural sugar and derivative can be obtained in a few synthetic steps from inexpensive starting materials.

  17. Stereodivergent synthesis with a programmable molecular machine

    Science.gov (United States)

    Kassem, Salma; Lee, Alan T. L.; Leigh, David A.; Marcos, Vanesa; Palmer, Leoni I.; Pisano, Simone

    2017-09-01

    It has been convincingly argued that molecular machines that manipulate individual atoms, or highly reactive clusters of atoms, with Ångström precision are unlikely to be realized. However, biological molecular machines routinely position rather less reactive substrates in order to direct chemical reaction sequences, from sequence-specific synthesis by the ribosome to polyketide synthases, where tethered molecules are passed from active site to active site in multi-enzyme complexes. Artificial molecular machines have been developed for tasks that include sequence-specific oligomer synthesis and the switching of product chirality, a photo-responsive host molecule has been described that is able to mechanically twist a bound molecular guest, and molecular fragments have been selectively transported in either direction between sites on a molecular platform through a ratchet mechanism. Here we detail an artificial molecular machine that moves a substrate between different activating sites to achieve different product outcomes from chemical synthesis. This molecular robot can be programmed to stereoselectively produce, in a sequential one-pot operation, an excess of any one of four possible diastereoisomers from the addition of a thiol and an alkene to an α,β-unsaturated aldehyde in a tandem reaction process. The stereodivergent synthesis includes diastereoisomers that cannot be selectively synthesized through conventional iminium-enamine organocatalysis. We anticipate that future generations of programmable molecular machines may have significant roles in chemical synthesis and molecular manufacturing.

  18. Synthesis of Siloxanes Directly from Amorphous Silica

    International Nuclear Information System (INIS)

    Myint Sandar Win

    2011-12-01

    A direct synthesis of oligomeric-siloxanes from amorphous silica has been achieved. The compound prepared was caedonal-siloxane. Cardonal is a mono hydroxyphenolic compound with a bulky group in the meta position. It was derived as a by-product from the renewable resources cashew nut shell liquid (CNSL). In the synthesis, one pot synthesis was carried out by using ethylene glycol (EG) as solvent. In the reaction ethylene glycol served as a primary precursor chelating ligand in the synthesised product. The one pot synthesis was enhanced by the strong base, triethylenetetramine (TETA) which served as the promoter catalyst. In the synthesis, optimal conditions were established on the basic of the yield percent of organo-siloxane compounds with respect to the variation of the weight fraction of TETA and to the variation of reaction time. Experimental runs were carried out at (ca 210 2c) which was nearly above the boiling point of the solvent. The substituted organo-silicon compounds obtained were characterized by FT- ir, Thermal analysis, XRD and SEM.

  19. Microwave mediated synthesis of semiconductor quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Afrasiabi, Roodabeh; Sugunan, Abhilash; Shahid, Robina; Toprak, Muhammet S.; Muhammed, Mamoun [Division of Functional Materials, Royal Institute of Technology (KTH), Stockholm (Sweden)

    2012-07-15

    Colloidal quantum dots (QD) have tuneable optoelectronic properties and can be easily handled by simple solution processing techniques, making them very attractive for a wide range of applications. Over the past decade synthesis of morphology controlled high quality (crystalline, monodisperse) colloidal QDs by thermal decomposition of organometallic precursors has matured and is well studied. Recently, synthesis of colloidal QDs by microwave irradiation as heating source is being studied due to the inherently different mechanisms of heat transfer, when compared to solvent convection based heating. Under microwave irradiation, polar precursor molecules directly absorb the microwave energy and heat up more efficiently. Here we report synthesis of colloidal II-VI semiconductor QDs (CdS, CdSe, CdTe) by microwave irradiation and compare it with conventional synthesis based on convection heating. Our findings show that QD synthesis by microwave heating is more efficient and the chalcogenide precursor strongly absorbs the microwave radiation shortening the reaction time and giving a high reaction yield (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Modelling of the enzymatic kinetically controlled synthesis of cephalexin

    NARCIS (Netherlands)

    Schroën, C.G.P.H.; Fretz, C.B.; Bruin, de V.H.; Berendsen, W.; Moody, H.M.; Roos, E.C.; Roon, van J.L.; Kroon, P.J.; Strubel, M.; Janssen, A.E.M.; Tramper, J.

    2002-01-01

    In this study the influence of diffusion limitation on enzymatic kinetically controlled cephalexin synthesis from phenylglycine amide and 7-aminodeacetoxycephalosporinic acid (7-ADCA) was investigated systematically. It was found that if diffusion limitation occurred, both the synthesis/hydrolysis

  1. Sustainable Alternatives for the Synthesis of Organics and Nanomaterials

    Science.gov (United States)

    The presentation summarizes recent activity in eco-friendly chemical synthesis, which involves benign alternatives, such as the use of supported reagents, and greener reaction medium in aqueous or solvent-free conditions. The synthesis of heterocyclic compounds, coupling reaction...

  2. RNA synthesis during cleavage of the Lymnaea egg

    NARCIS (Netherlands)

    Biggelaar, J.A.M. van den

    In eggs of Lymnaea RNA synthesis can be detected autoradiographically from the 8- to the 16-cell stage. From the 16- to the 24-cell stage distinct nucleoli reappear which are immediately engaged in RNA synthesis.

  3. Versatile three-component procedure for combinatorial synthesis of ...

    Indian Academy of Sciences (India)

    10. In recent years, several methods for the synthesis of spiro-oxindoles with fused 4H-chromenes via multi- component condensation reactions have been reported. The conventional synthesis involves a three-component condensation of ...

  4. PROTEIN SYNTHESIS INHIBITION AND MEMORY: FORMATION VS AMNESIA1

    OpenAIRE

    Gold, Paul E.

    2007-01-01

    Studies using protein synthesis inhibitors have provided key support for the prevalent view that memory formation requires the initiation of protein synthesis as a primary element of the molecular biology of memory. However, many other interpretations of the amnesia data have received far less attention. These include: a) Protein synthesis may play a constitutive role in memory formation, providing proteins prior to an experience that can be activated by training; b) Protein synthesis may be ...

  5. Synthesis of radio-metallofullerenols

    International Nuclear Information System (INIS)

    Keisuke Sueki; Yu Iwai

    2005-01-01

    Water-soluble fullerene derivatives have been investigated to date mostly within the framework of biological and medical applications. For example, C 60 derivatives have been applied as HIV inhibitors, radical scavenging capabilities and anti-cancer. The C 60 fullerenols, C 60 (OH) n , have been synthesized and have shown excellent water solubility. Kitazawa and co-workers also reported a more efficient reaction to obtain C 60 (OH) n , using NaOH aq and tetrabutylammonium hydroxide as a phase transfer catalyst. Water-soluble endohedral metallofullerene derivatives are particularly interesting because of their possible applications to radiotracers and magnetic resonance imaging (MRI) contrast agents. We investigate to trace the synthesis process of metallofullalnols using radioactivity, and obtain the effective process of radio-metallofullerenols. Carbon soot containing Sm endohedoral metallofullerenes was produced by the dc arc discharge method. The resulting soot was extracted with o-dichlorobenzene by reflux for 5 h. The obtained crude was irradiated for 30 min in the JRR4, After irradiation, crude was dissolved by toluene and filtrated by 0.2 μm pore size filter. The separation of the Sm doped C 82 including 153 Sm tracer from the crude was achieved by HPLC method which is a HPLC process on the Buckyprep column. We obtained fraction containing of three kinds of Sm doped C 82 . Details of the syntheses of endohedral metallofullerenols have been reported elsewhere. Briefly, toluene solutions of isolated Sm doped C 82 including 153 Sm with C 60 were vigorously vibrated with saturation KOH aq containing few drops of TBAH (10 % in water) as catalyst at room temperature. The reaction times were changed from l minute to 8 hours. The reaction mixture was filtrated by 0.2 μm filter. The residue was rinsed with methanol to ensure the removal of the catalyst and KOH. The rinsed residue was dissolved in water for 7 hours. The resultant brown- solution was the passed down

  6. Synthesis of Zirconium Lower Chlorides

    International Nuclear Information System (INIS)

    Gaviria, Juan P.

    2002-01-01

    This research is accurately related to the Halox concept of research reactor spent fuel element treatment.The aim of this project is to work the conditioning through selected chlorination of the element that make the spent fuel element. This research studied the physical chemistry conditions which produce formation of the lower zirconium chlorides through the reaction between metallic Zr and gaseous ZrCl 4 in a silica reactor.This work focused special attention in the analysis and confrontation of the published results among the different authors in order to reveal coincidences and contradictions.Experimental section consisted in a set of synthesis with different reaction conditions and reactor design. After reaction were analyzed the products on Zr shavings and the deposit growth on wall reactor.The products were strongly dependent of reactor design. It was observed that as the distance between Zr and wall reactor increased greater was tendency to lower chlorides formation.In reactors with small distance the reaction follows other way without formation of lower chlorides.Analysis on deposit growth on reactor showed that may be formed to a mixture of Si x Zr y intermetallics and zirconium oxides.Presence of oxygen in Zr and Zr-Si compounds on wall reactor reveals that there is an interaction between quartz and reactants.This interaction is in gaseous phase because contamination is observed in experiences where Zr was not in contact with reactor.Finally, it was made a global analysis of all experiences and a possible mechanism that interprets reaction ways is proposed

  7. Quantum chemistry-assisted synthesis route development

    International Nuclear Information System (INIS)

    Hori, Kenji; Sumimoto, Michinori; Murafuji, Toshihiro

    2015-01-01

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF 3 as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings

  8. Quantum chemistry-assisted synthesis route development

    Energy Technology Data Exchange (ETDEWEB)

    Hori, Kenji; Sumimoto, Michinori [Graduate School of Science and Engineering, Yamaguchi University, Tokiwadai, Ube, Yamaguchi 755-8611 (Japan); Murafuji, Toshihiro [Graduate School of Medicine, Yamaguchi University, Yamaguchi, Yamaguchi 753-8512 (Japan)

    2015-12-31

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF{sub 3} as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings.

  9. Green Chemistry Techniques for Gold Nanoparticles Synthesis

    Science.gov (United States)

    Cannavino, Sarah A.; King, Christy A.; Ferrara, Davon W.

    Gold nanoparticles (AuNPs) are often utilized in many technological and research applications ranging from the detection of tumors, molecular and biological sensors, and as nanoantennas to probe physical processes. As these applications move from the research laboratory to industrial settings, there is a need to develop efficient and sustainable synthesis techniques. Recent research has shown that several food products and beverages containing polyphenols, a common antioxidant, can be used as reducing agents in the synthesis of AuNPs in solution. In this study, we explore a variety of products to determine which allow for the most reproducible solution of nanoparticles based on the size and shapes of particles present. We analyzed the AuNPs solutions using extinction spectroscopy and atomic force microscopy. We also develop a laboratory activity to introduce introductory chemistry and physics students to AuNP synthesis techniques and analysis.

  10. Inorganic materials synthesis in ionic liquids

    Directory of Open Access Journals (Sweden)

    Christoph Janiak

    2014-01-01

    Full Text Available The field of "inorganic materials from ionic liquids" (ILs is a young and dynamically growing research area for less than 10 years. The ionothermal synthesis in ILs is often connected with the preparation of nanomaterials, the use of microwave heating and in part also ultrasound. Inorganic material synthesis in ILs allows obtaining phases which are not accessible in conventional organic or aqueous solvents or with standard methods of solid-state chemistry or under such mild conditions. Cases at hand include "ligand-free" metal nanoparticles without added stabilizing capping ligands, inorganic or inorganic-organic hybrid solid-state compounds, large polyhedral clusters and exfoliated graphene from low-temperature synthesis. There are great expectations that ILs open routes towards new, possibly unknown, inorganic materials with advantageous properties that cannot (or only with great difficulty be made via conventional processes.

  11. An efficient synthesis of loline alkaloids

    Science.gov (United States)

    Cakmak, Mesut; Mayer, Peter; Trauner, Dirk

    2011-07-01

    Loline (1) is a small alkaloid that, in spite of its simple-looking structure, has posed surprising challenges to synthetic chemists. It has been known for more than a century and has been the subject of extensive biological investigations, but only two total syntheses have been achieved to date. Here, we report an asymmetric total synthesis of loline that, with less then ten steps, is remarkably short. Our synthesis incorporates a Sharpless epoxidation, a Grubbs olefin metathesis and an unprecedented transannular aminobromination, which converts an eight-membered cyclic carbamate into a bromopyrrolizidine. The synthesis is marked by a high degree of chemo- and stereoselectivity and gives access to several members of the loline alkaloid family. It delivers sufficient material to support a programme aimed at studying the complex interactions between plants, fungi, insects and bacteria brokered by loline alkaloids.

  12. A review: radiolabeled synthesis of pesticides

    International Nuclear Information System (INIS)

    Li Juying; Han Ailiang; Wang Haiyan; Wang Wei; Ye Qingfu

    2010-01-01

    Isotope tracer technique has been widely applied in studies of metabolism, mode action, fate and environmental behavior of pesticides. In such studies, the key point is to obtain suitable radiolabelled compounds. However, the radiotracers, especially the labelled pesticides which are novel compounds with complex structures and longer synthesis routes, are usually unavailable from domestic and /or foreign markets. Therefore, it is essential to explore the synthesis methods of radiolabelled pesticides, which are quite different from the conventional nonradiosynthesis, and are requested to obtain higher yield. This article is a review on current status of choosing the available radionuclide and labelled position, the main synthesis methods and problems in the process of preparing radiolabelled pesticides. (authors)

  13. Computer-assisted spectral design and synthesis

    Science.gov (United States)

    Vadakkumpadan, Fijoy; Wang, Qiqi; Sun, Yinlong

    2005-01-01

    In this paper, we propose a computer-assisted approach for spectral design and synthesis. This approach starts with some initial spectrum, modifies it interactively, evaluates the change, and decides the optimal spectrum. Given a requested change as function of wavelength, we model the change function using a Gaussian function. When there is the metameric constraint, from the Gaussian function of request change, we propose a method to generate the change function such that the result spectrum has the same color as the initial spectrum. We have tested the proposed method with different initial spectra and change functions, and implemented an interactive graphics environment for spectral design and synthesis. The proposed approach and graphics implementation for spectral design and synthesis can be helpful for a number of applications such as lighting of building interiors, textile coloration, and pigment development of automobile paints, and spectral computer graphics.

  14. Mapping Out Biogenetic Hypotheses by Chemical Synthesis.

    Science.gov (United States)

    Liffert, Raphael; Gademann, Karl

    2017-12-01

    Synthesis of natural products via their postulated or established biosynthetic intermediates ('biomimetic synthesis' or 'bio-inspired synthesis') has the power to identify both yet undiscovered intermediates and undiscovered mechanistic pathways for their formation. In this account, we report on our recent studies on unusual hypotheses for biosynthetic transformations, such as a late-stage aldol reaction (periconianone A), benzilic acid rearrangement (taiwaniaquinone H), a redox-neutral light-driven C-H activation (taiwaniaquinol A and cyclocoulterone), a hetero Diels-Alder reaction (obtusinones), aziridinium chemistry (Securinega alkaloids), and a [3+2] nitrone olefin cycloaddition (virosaine A). All these studies provided evidence on the molecular level for the feasibility of these transformations, and suggest that further studies investigating the relevance of these hypotheses in biological systems are warranted.

  15. Processing of hydroxyapatite obtained by combustion synthesis

    International Nuclear Information System (INIS)

    Canillas, M.; Rivero, R.; García-Carrodeguas, R.; Barba, F.; Rodríguez, M.A.

    2017-01-01

    One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties. [es

  16. Processing of hydroxyapatite obtained by combustion synthesis

    Directory of Open Access Journals (Sweden)

    M. Canillas

    2017-09-01

    Full Text Available One of the reasons of implants failure are the stress forces appearing in the material–tissue interface due to the differences between their mechanical properties. For this reason, similar mechanical properties to the surrounding tissue are desirable. The synthesis of hydroxyapatite by solution combustion method and its processing have been studied in order to obtain fully dense ceramic bodies with improved mechanical strength. Combustion synthesis provides nanostructured powders characterized by a high surface area to facilitate the following sintering. Moreover, synthesis was conducted in aqueous and oxidizing media. Oxidizing media improve homogenization and increase the energy released during combustion. It gives rise to particles whose morphology and size suggest lower surface energies compared with aqueous media. The obtained powders were sintered by using a controlled sintering rate schedule. Lower surfaces energies minimize the shrinkage during sintering and relative densities measurements and diametral compression test confirm improved densification and consequently mechanical properties.

  17. Asymmetric synthesis II more methods and applications

    CERN Document Server

    Christmann, Mathias

    2012-01-01

    After the overwhelming success of 'Asymmetric Synthesis - The Essentials', narrating the colorful history of asymmetric synthesis, this is the second edition with latest subjects and authors. While the aim of the first edition was mainly to honor the achievements of the pioneers in asymmetric syntheses, the aim of this new edition was bringing the current developments, especially from younger colleagues, to the attention of students. The format of the book remained unchanged, i.e. short conceptual overviews by young leaders in their field including a short biography of the authors. The growing multidisciplinary research within chemistry is reflected in the selection of topics including metal catalysis, organocatalysis, physical organic chemistry, analytical chemistry, and its applications in total synthesis. The prospective reader of this book is a graduate or undergraduate student of advanced organic chemistry as well as the industrial chemist who wants to get a brief update on the current developments in th...

  18. Synthesis and processing of nanostructured materials

    International Nuclear Information System (INIS)

    Siegel, R.W.

    1992-12-01

    Significant and growing interest is being exhibited in the novel and enhanced properties of nanostructured materials. These materials, with their constituent phase or grain structures modulated on a length scale less than 100 nm, are artificially synthesized by a wide variety of physical, chemical, and mechanical methods. In this NATO Advanced Study Institute, where mechanical behavior is emphasized, nanostructured materials with modulation dimensionalities from one (multilayers) to three (nanophase materials) are mainly considered. No attempt is made in this review to cover in detail all of the diverse methods available for the synthesis of nanostructured materials. Rather, the basic principles involved in their synthesis are discussed in terms of the special properties sought using examples of particular synthesis and processing methodologies. Some examples of the property changes that can result from one of these methods, cluster assembly of nanophase materials, are presented

  19. Synthesis, Transfer, and Characterization of Nanoscale 2-Dimensional Materials

    Science.gov (United States)

    2015-09-01

    stack is floating on top of the DDI water surface. Instead of removing the stack with the target substrate, a graphene/copper foil substrate (graphene...demonstrated the synthesis of graphene, hexagonal boron nitride, and bismuth telluride using chemical and physical vapor deposition techniques. Making...for material synthesis, transfer, and characterization. 15. SUBJECT TERMS graphene, hexagonal boron nitride, bismuth telluride, synthesis, transfer

  20. Microwave-assisted rapid synthesis of Si-MCM-41

    Indian Academy of Sciences (India)

    Administrator

    synthesis of inorganic porous solids like zeolites has been reported to reduce the synthesis time significantly. Recently, Chen-Guey Wu and Thomas Bein have reported the synthesis of Al-MCM-41 using temperature control microwave ovens within about. 1 h with tetramethylammonium silicate and Hi Sil T600 as a source of ...

  1. Importance of Synthesis and Role of synthetic organic chemist

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Synthesis of natural products is taken up as: Synthesis of natural products is taken up as: Natural sources are limited; The compounds are available in very small quantities; To achieve efficient synthesis. Synthesize target molecule of importance/ interest using existing tools of ...

  2. Chemo-enzymatic peptide synthesis : bioprocess engineering aspects

    NARCIS (Netherlands)

    Vossenberg, P.

    2012-01-01

    Peptides, in particular oligopeptides, play an important role in the fields of health care, nutrition and cosmetics. Chemical synthesis is currently the most mature technique for the synthesis of peptides that range in length from 5 to 80 amino acids. Chemical synthesis is, however,

  3. SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6 ...

    African Journals Online (AJOL)

    SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6-DISUBSTITUTED-1,2,4-. TRIAZOLO-1,3 ... Thus, many chemists reported synthesis and antimicrobial activity of some 1,2,4-triazolothiadiazole derivatives in ..... N.H. Synthesis and biological activity of oxadiazole and triazolothiadiazole derivatives as tyrosinase inhibitors.

  4. Nickel nanoparticles: A highly efficient catalyst for one pot synthesis ...

    Indian Academy of Sciences (India)

    synthesis of tetraketones and biscoumarins. JITENDER M KHURANA. ∗ ... designed wherein, polyvinyl pyrrolidone (PVP) stabilized nickel nanoparticles have been used as a catalyst for promoting the synthesis of 2,2 -aryl-methylene ..... synthesis of tetraketones (3) and bis- coumarins (4) using air stable PVP coated nickel.

  5. An environmentally benign one pot synthesis of substituted ...

    Indian Academy of Sciences (India)

    Organic synthesis generally required large amount of solvent, avoiding the use of organic solvents in synthesis is a paradigm shift directed at developing more benign chemistry, and with ionic liquids surprisingly can lead to access to new compounds. An elegant one-pot synthesis of quinoline derivatives has been achieved ...

  6. Uncertainty analysis: an evaluation metric for synthesis science

    Science.gov (United States)

    Mark E. Harmon; Becky Fasth; Charles B. Halpern; James A. Lutz

    2015-01-01

    The methods for conducting reductionist ecological science are well known and widely used. In contrast, those used in the synthesis of ecological science (i.e., synthesis science) are still being developed, vary widely, and often lack the rigor of reductionist approaches. This is unfortunate because the synthesis of ecological parts into a greater whole is...

  7. Protein Synthesis Initiation Factors: Phosphorylation and Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Karen S. Browning

    2009-06-15

    The initiation of the synthesis of proteins is a fundamental process shared by all living organisms. Each organism has both shared and unique mechanisms for regulation of this vital process. Higher plants provide for a major amount of fixation of carbon from the environment and turn this carbon into food and fuel sources for our use. However, we have very little understanding of how plants regulate the synthesis of the proteins necessary for these metabolic processes. The research carried out during the grant period sought to address some of these unknowns in the regulation of protein synthesis initiation. Our first goal was to determine if phosphorylation plays a significant role in plant initiation of protein synthesis. The role of phosphorylation, although well documented in mammalian protein synthesis regulation, is not well studied in plants. We showed that several of the factors necessary for the initiation of protein synthesis were targets of plant casein kinase and showed differential phosphorylation by the plant specific isoforms of this kinase. In addition, we identified and confirmed the phosphorylation sites in five of the plant initiation factors. Further, we showed that phosphorylation of one of these factors, eIF5, affected the ability of the factor to participate in the initiation process. Our second goal was to develop a method to make initiation factor 3 (eIF3) using recombinant methods. To date, we successfully cloned and expressed 13/13 subunits of wheat eIF3 in E. coli using de novo gene construction methods. The final step in this process is to place the subunits into three different plasmid operons for co-expression. Successful completion of expression of eIF3 will be an invaluable tool to the plant translation community.

  8. Alternative Fuels and Chemicals From Synthesis Gas

    Energy Technology Data Exchange (ETDEWEB)

    none

    1998-07-01

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  9. Alternative fuels and chemicals from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1998-08-01

    The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

  10. Low Temperature Synthesis of Magnesium Aluminate Spinel

    International Nuclear Information System (INIS)

    Lebedovskaya, E.G.; Gabelkov, S.V.; Litvinenko, L.M.; Logvinkov, D.S.; Mironova, A.G.; Odejchuk, M.A.; Poltavtsev, N.S.; Tarasov, R.V.

    2006-01-01

    The low-temperature synthesis of magnesium-aluminum spinel is carried out by a method of thermal decomposition in combined precipitated hydrates. The fine material of magnesium-aluminium spinel with average size of coherent dispersion's area 4...5 nanometers is obtained. Magnesium-aluminum spinel and initial hydrates were investigated by methods of the differential thermal analysis, the x-ray phase analysis and measurements of weight loss during the dehydration and thermal decomposition. It is established that synthesis of magnesium-aluminum spinel occurs at temperature 300 degree C by method of the x-ray phase analysis

  11. Synthesis and structures of metal chalcogenide precursors

    Science.gov (United States)

    Hepp, Aloysius F.; Duraj, Stan A.; Eckles, William E.; Andras, Maria T.

    1990-01-01

    The reactivity of early transition metal sandwich complexes with sulfur-rich molecules such as dithiocarboxylic acids was studied. Researchers recently initiated work on precursors to CuInSe2 and related chalcopyrite semiconductors. Th every high radiation tolerance and the high absorption coefficient of CuInSe2 makes this material extremely attractive for lightweight space solar cells. Their general approach in early transition metal chemistry, the reaction of low-valent metal complexes or metal powders with sulfur and selenium rich compounds, was extended to the synthesis of chalcopyrite precursors. Here, the researchers describe synthesis, structures, and and routes to single molecule precursors to metal chalcogenides.

  12. Tomo-synthesis. Bibliographic study report

    International Nuclear Information System (INIS)

    2016-01-01

    Tomo-synthesis is a recent technique for breast imaging. This technique, qualified as 'pseudo-3D', draws the attention of health professionals. Indeed, this technique could offer a gain in sensibility and in specificity in the detection of breast cancers compared to 2D mammography, thanks to the reduction of the tissues' overlapping in particular. Although its place and its clinical indication are not still clearly defined, tomo-synthesis is already used in France. The introduction of this technique within the national breast cancer screening program, seems to be foreseen by the authorities in the coming years. IRSN, in the scope of its mission of evaluation of the dose impact of innovative techniques, is closely interested in this technique and has proceeded in 2015 to a bibliographical review of the state of the art in tomo-synthesis. This review paid specific attention to the following points: conception of the installations, dose, image quality and quality control. it has highlighted several points of attention, which incite IRSN to formulate certain recommendations to accompany the spreading of this new technique in France. Most of the clinical trials validating the use of tomo-synthesis were realized on systems of a single manufacturer. However, manufacturers' strategies of design are heterogeneous. There is no unique technique of tomo-synthesis but several, of which equivalence in terms of technical and clinical performances is not demonstrated. Due to the heterogeneity of the different models available on the French market, IRSN recommends not to extrapolate the results of clinical studies obtained on a specific system but to consolidate them for all the available systems. In many imaging departments, tomo-synthesis is already implemented in addition or in substitution of 2D mammography without any regulatory quality control and periodic technical checks. The European reference standard for quality control of these devices is not yet

  13. Camera-enabled techniques for organic synthesis

    Directory of Open Access Journals (Sweden)

    Steven V. Ley

    2013-05-01

    Full Text Available A great deal of time is spent within synthetic chemistry laboratories on non-value-adding activities such as sample preparation and work-up operations, and labour intensive activities such as extended periods of continued data collection. Using digital cameras connected to computer vision algorithms, camera-enabled apparatus can perform some of these processes in an automated fashion, allowing skilled chemists to spend their time more productively. In this review we describe recent advances in this field of chemical synthesis and discuss how they will lead to advanced synthesis laboratories of the future.

  14. Diamond synthesis by lasers: recent progress

    Directory of Open Access Journals (Sweden)

    Gordana S. Ristić

    2012-01-01

    Full Text Available This paper provides an up-to-date critical review of methods for diamond synthesis by lasers. A provisional classification of synthesizing methods is carried out, in order to present a varied and heterogeneous experimental work that is as clear as possible. Laser diamond CVD methods involve chemical processes in a carbon-containing system induced by specific absorption of laser radiation, while diamond PVD methods involve physical processes induced by an intense, highly-directed laser beam. Different methods involving coupled, simultaneous action of lasers and classic CVD agents are suggested and discussed as prospective approaches for diamond synthesis.

  15. Synthesis of isotopically labeled threat agents

    International Nuclear Information System (INIS)

    Ott, D.G.; Reisfeld, M.J.; Whaley, T.W.

    1986-01-01

    The blister agents, bis(2-chloroethyl) sulfide (HD or sulfur mustard) and dichloro(2-chlorovinyl)arsine (L or Lewisite) were prepared with carbon-14 at all carbon atoms. The synthesis of HD proceeded from 2-bromoethanol. In the Lewisite synthesis, chloro(2-chlorovinyl)mercury, from acetylene, was converted to L, along with the bis- and tris-(chlorovinyl) compounds, which were separated by thin layer chromatography. The nerve agents, isopropyl methylphosphonofluoridate (GB or sarin) and pinacolyl methylphosphonofluoridate (GD or soman) were labeled in the methyl group attached to phosphorus with either deuterium, tritium, or carbon-14 starting from the labeled iodomethane. 4 refs

  16. Cooperative catalysis designing efficient catalysts for synthesis

    CERN Document Server

    Peters, René

    2015-01-01

    Written by experts in the field, this is a much-needed overview of the rapidly emerging field of cooperative catalysis. The authors focus on the design and development of novel high-performance catalysts for applications in organic synthesis (particularly asymmetric synthesis), covering a broad range of topics, from the latest progress in Lewis acid / Br?nsted base catalysis to e.g. metal-assisted organocatalysis, cooperative metal/enzyme catalysis, and cooperative catalysis in polymerization reactions and on solid surfaces. The chapters are classified according to the type of cooperating acti

  17. Advanced frequency synthesis by phase lock

    CERN Document Server

    Egan, William F

    2011-01-01

    "An addendum to the popular Frequency Synthesis by Phase Lock, 2nd ed, this book describes sigma-delta, a frequency synthesis technique that has gained prominence in recent years. In addition, Simulink will be employed extensively to guide the reader. Fractional-n, the still-used forerunner to sigma-delta, is also discussed. Sequences of simulated results allow the reader to gain a deeper understanding while detailed appendices provide information from various stages of development. Simulation models discussed in the chapters that are available online."--Provided by publisher.

  18. Many Putative Endocrine Disruptors Inhibit Prostaglandin Synthesis

    DEFF Research Database (Denmark)

    Kristensen, David M.; Skalkam, Maria L.; Audouze, Karine Marie Laure

    2011-01-01

    Background: Prostaglandins (PGs) play key roles in development and maintenance of homeostasis of the adult body. Despite these important roles, it remains unclear whether the PG pathway is a target for endocrine disruption. However, several known endocrine disrupting compounds (EDCs) share a high...... of endocrine disruption. Results: We found that many known EDCs inhibit the PG pathway in a mouse Sertoli cell line and in human primary mast cells. The EDCs also reduced PG synthesis in ex vivo rat testis and it was correlated with a reduced testosterone production. The inhibition of PG synthesis occurs...

  19. Synthesis of new radiotracers based on aniline

    International Nuclear Information System (INIS)

    Ayari, Issra

    2008-01-01

    There are several possible applications of radioactivity, we cite: the study of the functional and neurochirnical aspects related to the brain. This study requires the synthesis of specific radiotracers able to cross their target tissue. The synthesis methods need to be constantly updated to respond to the big demand of this domain. The development of the chemistry of metal complexes helped us to find a stable radiotracer based on aniline and marked with technetium. This stability aI 10wed us to realize a possible biodistribution and to envisage to count the radioactivity and to valid the radiopharmaceutical. (Author)

  20. Synthesis of pure Portland cement phases

    DEFF Research Database (Denmark)

    Wesselsky, Andreas; Jensen, Ole Mejlhede

    2009-01-01

    Pure phases commonly found in Portland cement clinkers are often used to test cement hydration behaviour in simplified experimental conditions. The synthesis of these phases is covered in this paper, starting with a description of phase relations and possible polymorphs of the four main phases...... in Portland cement, i.e. tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium alumino ferrite. Details of the The process of solid state synthesis are is described in general including practical advice on equipment and techniques. Finally In addition, some exemplary mix compositions...

  1. Synthesis of Nano-Particles in Flames

    DEFF Research Database (Denmark)

    Johannessen, Tue

    The scope of this work is to investigate the synthesis of aluminum oxide particles in flames from the combustion of an aluminum alkoxide precursor.A general introduction to particles formation in the gas phase is presented with emphasis on the mechanisms that control the particle morphology after...... energy expression.Furthermore, the model is validated by comparison with experimental data of the flame synthesis of titania by combustion of TiCl4 previously presented by Pratsinis et al. (1996).The combination of particle dynamics and CFD simulations has proved to be an efficient method...

  2. Synthesis of solid solutions of perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Dambekalne, M.Y.; Antonova, M.K.; Perro, I.T.; Plaude, A.V.

    1986-03-01

    The authors carry out thermographic studies, using a derivatograph, in order to understand the nature of the processes taking place during the synthesis of solid solutions of perovskites. Based on the detailed studies on the phase transformations occurring in the charges of the PSN-PMN solid solutions and on the selection of the optimum conditions for carrying out their synthesis, the authors obtained a powder containing a minimum quantity of the undesirable pyrochlore phase and by sintering it using the hot pressing method, they produced single phase ceramic specimens containing the perovskite phase alone with a density close to the theoretical value and showing zero apparent porosity and water absorption.

  3. Defining Life: Synthesis and Conclusions

    Science.gov (United States)

    Gayon, Jean

    2010-04-01

    The first part of the paper offers philosophical landmarks on the general issue of defining life. §1 defends that the recognition of “life” has always been and remains primarily an intuitive process, for the scientist as for the layperson. However we should not expect, then, to be able to draw a definition from this original experience, because our cognitive apparatus has not been primarily designed for this. §2 is about definitions in general. Two kinds of definition should be carefully distinguished: lexical definitions (based upon current uses of a word), and stipulative or legislative definitions, which deliberately assign a meaning to a word, for the purpose of clarifying scientific or philosophical arguments. The present volume provides examples of these two kinds of definitions. §3 examines three traditional philosophical definitions of life, all of which have been elaborated prior to the emergence of biology as a specific scientific discipline: life as animation (Aristotle), life as mechanism, and life as organization (Kant). All three concepts constitute a common heritage that structures in depth a good deal of our cultural intuitions and vocabulary any time we try to think about “life”. The present volume offers examples of these three concepts in contemporary scientific discourse. The second part of the paper proposes a synthesis of the major debates developed in this volume. Three major questions have been discussed. A first issue (§4) is whether we should define life or not, and why. Most authors are skeptical about the possibility of defining life in a strong way, although all admit that criteria are useful in contexts such as exobiology, artificial life and the origins of life. §5 examines the possible kinds of definitions of life presented in the volume. Those authors who have explicitly defended that a definition of life is needed, can be classified into two categories. The first category (or standard view) refers to two conditions

  4. Mo-catalyzed asymmetric olefin metathesis in target-oriented synthesis: Enantioselective synthesis of (+)-africanol

    Science.gov (United States)

    Weatherhead, Gabriel S.; Cortez, G. A.; Schrock, Richard R.; Hoveyda, Amir H.

    2004-01-01

    Catalytic asymmetric ring-opening metathesis (AROM) provides an efficient method for the synthesis of a variety of optically enriched small organic molecules that cannot be easily prepared by alternative methods. The development of Mo-catalyzed AROM transformations that occur in tandem with ring-closing metathesis are described. The utility of the Mo-catalyzed AROM/ring-closing metathesis is demonstrated through an enantioselective approach to the synthesis of (+)-africanol. PMID:15056762

  5. Synthesis of 4-Halogenated 3-Fluoro-6-methoxyquinolines: Key Building Blocks for the Synthesis of Antibiotics

    DEFF Research Database (Denmark)

    Flagstad, Thomas; Petersen, Mette Terp; Hinnerfeldt, Daniel Michael

    2014-01-01

    A practical and scalable 4-step route is presented for the synthesis of 4-bromo-3-fluoro-6-methoxyoquinoline and 3-fluoro-4-iodo-6-methoxyoquinoline from readily available 2,4-dichloro-3-fluoroquinoline with an overall yield of 81-85%. Halogenated quinoline building blocks have found much use in ...... in antimicrobial drug discovery, and the method reported here would be useful for the synthesis of these compounds. © Georg Thieme Verlag....

  6. Recent advances in microwave initiated synthesis of nanocarbon materials

    Science.gov (United States)

    Zhang, Xinyu; Liu, Zhen

    2012-01-01

    This Feature Article focuses on the recent advances in synthesis of nanostructured carbon materials using microwave irradiation as the heating source. Although the microwave approach to chemical synthesis is relatively mature in organic synthesis, it is still in the early stage for nanomaterials synthesis, especially nanocarbons. Due to the energy efficient nature of microwave heating, there is a great opportunity to apply microwave irradiation to nanocarbon production, which normally requires high temperature, high vacuum or inert gas protections. Using microwave irradiation will give a green feature to the nanocarbon synthesis, since it offers high efficiency heating and fast carbonization. With our recent discovery, multi-walled carbon nanotubes can be synthesized through the microwave process even in air. Background about nanocarbons and microwave chemistry are introduced, the application of microwaves in synthesis of different types of nanocarbons is discussed and finally, the perspectives in the future research directions of microwave assisted nanocarbon synthesis are deliberated as well.

  7. Synthesis and characterization of nanophased silver tungstate

    Indian Academy of Sciences (India)

    of silver tungstate nanoparticles. 2. Experimental. Silver tungstate nanoparticles were synthesized by reacting AR grade silver nitrate. (AgNO3) and sodium tungstate (Na2WO4) using distilled water as solvent at room temperature. The method followed for this synthesis is similar to that used by. Takahashi et al [9]. However ...

  8. Synthesis and Characterization of Colloidal MCM-41

    Czech Academy of Sciences Publication Activity Database

    Rathouský, Jiří; Zukalová, Markéta; Kooyman, P. J.; Zukal, Arnošt

    2004-01-01

    Roč. 241, - (2004), s. 81-86 ISSN 0927-7757 Institutional research plan: CEZ:AV0Z4040901 Keywords : colloidal MCM-41 * homogeneous precipitation * salt effect in the synthesis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.513, year: 2004

  9. Total synthesis of sannanine and analogues thereof

    Indian Academy of Sciences (India)

    BADHER NAVEEN

    2018-03-02

    Mar 2, 2018 ... concise manner. The key strategies involve Friedländer quinoline synthesis, demethylation, in situ oxidation and amination process. ..... (b) Hargreaves R, David C L, Whitesell L and Skibo E. B 2003 Design of Quinolinedione-Based Geldanamycin. Analogues Bioorg. Med. Chem. Lett. 13 3075; (c) Arg-.

  10. Synthesis and spectroscopic properties of homo- and ...

    Indian Academy of Sciences (India)

    Unknown

    Mehrotra. Synthesis and spectroscopic properties of homo- and heterobimetallic complexes of oxovanadium(V). † ... Spectroscopic (IR, UV–Vis and (1H, 27Al, 51V) NMR) properties of the new com- plexes have been investigated and their ... refluxed under a fractionating column (10 cm), fol- lowed by continuous azeotropic ...

  11. Colloidal phytosterols: synthesis, characterization and bioaccessibility

    NARCIS (Netherlands)

    Rossi, L.; Seijen ten Hoorn, J.W.M.; Melnikov, S.M.; Velikov, K.P.

    2010-01-01

    We demonstrate the synthesis of phytosterol colloidal particles using a simple food grade method based on antisolvent precipitation in the presence of a non-ionic surfactant. The resulting colloidal particles have a rod-like shape with some degree of crystallinity. The colloidal dispersions display

  12. Woodward's Synthesis of Vitamin B12

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 6. Woodward's Synthesis of Vitamin B12. Adil Ghani Khan S V Eswaran. General Article Volume 8 Issue 6 June 2003 pp 8-16. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/06/0008-0016 ...

  13. Total synthesis of sannanine and analogues thereof

    Indian Academy of Sciences (India)

    BADHER NAVEEN

    2018-03-02

    Mar 2, 2018 ... The key strategies involve Friedländer quinoline synthesis, demethylation, in situ oxidation and amination process. ... dramatic changes in biological as well as photo-physical properties of quinoline-5,8-dione. Due to ..... intention of choosing the substitution in the quinoline-. 5,8-dione core was to develop ...

  14. Total synthesis of insect antifeedant drimane sesquiterpenes

    NARCIS (Netherlands)

    Jansen, B.J.M.

    1993-01-01

    The investigations described in this thesis deal with the total synthesis of sesquiterpenes of the drimane family, named for their widespread occurrence in the stem bark of South American Drimys species. These compounds contain the bicyclofarnesol nucleus

  15. Synthesis and Characterization of Nanostructured Sulfated Zirconias

    Czech Academy of Sciences Publication Activity Database

    Lutecki, M.; Šolcová, Olga; Werner, S.; Breitkopf, C.

    2010-01-01

    Roč. 53, č. 1 (2010), s. 13-20 ISSN 0928-0707 Grant - others:DFG(DE) BR2068/2-1; DFG(DE) BR2068/2-2 Institutional research plan: CEZ:AV0Z40720504 Keywords : sulfated zirconia * template assisted synthesis * porous materials Subject RIV: CA - Inorganic Chemistry Impact factor: 1.525, year: 2010

  16. The electrochemical synthesis of europium boride

    Directory of Open Access Journals (Sweden)

    Bukatova G.A.

    2003-01-01

    Full Text Available The electroreduction of boron, europium and the electrochemical synthesis of europium boride have been investigated in NaCl-KCl-NaF(10 wt. % melt on silver and molybdenum electrodes. The parameters of boron reduction in the chloride-fluoride melt have been obtained and the character of its joint deposition with europium has been studied.

  17. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    Nanoparticles are produced by various methods like physical, chemical, mechanical and biological. Biological me- thods of ... Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced ... for the biomimetic synthesis and characterization of protein capped silver nanoparticles.

  18. Microwave assisted template synthesis of silver nanoparticles

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Easier, less time consuming, green processes, which yield silver nanoparticles of uniform size, shape and morphology are of interest. Various methods for synthesis, such as conventional temperature as- sisted process, controlled reaction at elevated temperatures, and microwave assisted process have been evalu ...

  19. Vitamins and aging: pathways to NAD+ synthesis.

    Science.gov (United States)

    Denu, John M

    2007-05-04

    Recent genetic evidence reveals additional salvage pathways for NAD(+) synthesis. In this issue, Belenky et al. (2007) report that nicotinamide riboside, a new NAD(+) precursor, regulates Sir2 deacetylase activity and life span in yeast. The ability of nicotinamide riboside to enhance life span does not depend on calorie restriction.

  20. Ionothermal synthesis and structural characterization of [Cu ...

    Indian Academy of Sciences (India)

    bSchool of Chemistry and Chemical Engineering, Harbin Normal University, No. 1 Shida Road Limin development Zone, Harbin 150025, P. R. China e-mail: caiqinghai@yahoo.com. MS received 29 December 2014; revised 2 April 2015; accepted 3 April 2015. Abstract. The ionothermal synthesis and spectroscopic, thermal ...

  1. Design, synthesis and computational validation of novel ...

    Indian Academy of Sciences (India)

    The design and synthesis of benzimidazolyl and indolyl linked -alkoxy phenylpropanoic acid derivatives and the -keto ester analogues in an effort to develop novel peroxisome proliferator activated receptors ligands expected to exhibit PPAR and PPAR partial agonism in the management of hyperglycemia and ...

  2. Bridging polymer synthesis and ease in processing

    NARCIS (Netherlands)

    Romano, Dario

    2017-01-01

    High Performance polymeric materials are a subject of considerable interest due to their high mechanical performances when combined with their versatility in processing and synthesis. In order to achieve high mechanical properties, scientist focuses on increasing the molecular weight of the polymer

  3. Synthesis of Tetracyclic Diterpenoids with Pharmacologic Relevance

    Czech Academy of Sciences Publication Activity Database

    Šíša, Miroslav; Vaněk, Tomáš

    2016-01-01

    Roč. 22, č. 12 (2016), s. 1767-1807 ISSN 1381-6128 R&D Projects: GA MŠk(CZ) LD15006 Institutional support: RVO:61389030 Keywords : Diterpenoids * synthesis * biological activity Subject RIV: CE - Biochemistry Impact factor: 2.611, year: 2016

  4. Biological synthesis of nanoparticles in biofilms.

    Science.gov (United States)

    Tanzil, Abid H; Sultana, Sujala T; Saunders, Steven R; Shi, Liang; Marsili, Enrico; Beyenal, Haluk

    2016-12-01

    The biological synthesis of nanoparticles (NPs) by bacteria and biofilms via extracellular redox reactions has received attention because of the minimization of harmful chemicals, low cost, and ease of culturing and downstream processing. Bioreduction mechanisms vary across bacteria and growth conditions, which leads to various sizes and shapes of biosynthesized NPs. NP synthesis in biofilms offers additional advantages, such as higher biomass concentrations and larger surface areas, which can lead to more efficient and scalable biosynthesis. Although biofilms have been used to produce NPs, the mechanistic details of NP formation are not well understood. In this review, we identify three critical areas of research and development needed to advance our understanding of NP production by biofilms: 1) synthesis, 2) mechanism and 3) stabilization. Advancement in these areas could result in the biosynthesis of NPs that are suitable for practical applications, especially in drug delivery and biocatalysis. Specifically, the current status of methods and mechanisms of nanoparticle synthesis and surface stabilization using planktonic bacteria and biofilms is discussed. We conclude that the use of biofilms to synthesize and stabilize NPs is underappreciated and could provide a new direction in biofilm-based NP production. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Structured synthesis of MEMS using evolutionary approaches

    DEFF Research Database (Denmark)

    Fan, Zhun; Wang, Jiachuan; Achiche, Sofiane

    2008-01-01

    In this paper, we discuss the hierarchy that is involved in a typical MEMS design and how evolutionary approaches can be used to automate the hierarchical synthesis process for MEMS. The paper first introduces the flow of a structured MEMS design process and emphasizes that system-level lumped...... the integrated design automation idea using these evolutionary approaches....

  6. Synthesis and NMR Elucidation of Novel Pentacycloundecane ...

    African Journals Online (AJOL)

    Herein we report the synthesis and NMR elucidation of five novel pentacycloundecane (PCU)-derived short peptides as potential HIV protease inhibitors. 1H and 13C spectral analysis show major overlapping of methine resonance of the PCU 'cage' thereby making it extremely difficult to assign the NMR signals. Attachment ...

  7. Patterns of urease synthesis in developing soybeans.

    Science.gov (United States)

    Polacco, J C; Sparks, R B

    1982-07-01

    An examination of in vivo polysome-bound activity indicates that soybean (Glycine max, cv. Prize) seed urease is synthesized on large polysomes (n >/= 15). In vitro urease synthesis is directed by a large RNA (3,000-3,300 nucleotides). Urease synthesis occurs throughout the normal protein biosynthetic phase of the developing seed. Surprisingly, the activity/antigen ratios of urease increase throughout development. Urease appears to be in a more highly polymerized state in mature beans versus beans in early development.During the 55 days from pollination to maturity, urease specific antigen (antigen versus total seed protein) is greatest on the 20th day, representing 0.6% of total extractable protein. Its synthesis proceeds until the end of the protein biosynthetic phase, approximately day 40. In contrast, the appearance of urease enzyme activity lags that of antigen during early development (11-20 days) and plateaus in late development. Mixing experiments suggest no role for putative urease inhibitors or activators during development. However, several electrophoretically slow migrating forms are unique to the urease of mature beans. It is not known if these are more active species.An active urease species exhibits an RNAse-sensitive cosedimentation with a heavy polyribosome class (n >/= 15). Polyadenylated RNA, size-fractionated to 3,000 to 3,300 bases, directed the synthesis in vitro of a major translational product electrophoretically and immunologically similar to the in vivo-synthesized urease subunit.

  8. Synthesis and optical characterization of copper nanoparticles ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 1. Synthesis and optical characterization of copper nanoparticles prepared by laser ablation. SAMIRA MONIRI MAHMOOD GHORANNEVISS MOHAMMAD REZA HANTEHZADEH MOHSEN ASADI ASADABAD. Volume 40 Issue 1 February 2017 pp 37-43 ...

  9. Synthesis, spectral characterization and in vitro antibacterial ...

    African Journals Online (AJOL)

    Shafqat Nadeem

    2015-12-17

    Dec 17, 2015 ... Petra/Osiris/Molinspiration analysis. Abstract The paper emphasizes on the synthesis of Palladium(II) iodide complexes containing based ligands. The new compounds .... The spectral conditions were as follows: 32 K data points,. 1.822 s acquisition time, 2.00 s pulse delay and 6.00 ls pulse width. The 13C ...

  10. Benzodiazepine Synthesis and Rapid Toxicity Assay

    Science.gov (United States)

    Fletcher, James T.; Boriraj, Grit

    2010-01-01

    A second-year organic chemistry laboratory experiment to introduce students to general concepts of medicinal chemistry is described. Within a single three-hour time window, students experience the synthesis of a biologically active small molecule and the assaying of its biological toxicity. Benzodiazepine rings are commonly found in antidepressant…

  11. Synthesis and pharmaceutical importance of 2-azetidinone ...

    Indian Academy of Sciences (India)

    The compound 2 on further reaction with several substituted aromatic aldehydes produced N-[3-(10H- phenothiazin-1-yl)propyl]-N ... Synthesis; 2-azetidinone; phenothiazine; antimicrobial. 1. Introduction. The β-lactam ring is the ..... Samadhiya P S, Sharma R, Srivastava S K and Srivastava. S D 2011 J. Chem. Sci. 123(5) ...

  12. The synthesis of ammonia from its elements

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 9. The Synthesis of Ammonia from its Elements. Fritz Haber. Classics Volume 7 Issue 9 September 2002 pp 86-94. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/007/09/0086-0094 ...

  13. The Synthesis of Carbon Nanomaterials using Chlorinated ...

    African Journals Online (AJOL)

    NICOLAAS

    Formation of 'bamboo-like' structures for the MWCNTs generated from TCE and TTCE was also observed, facilitated by the ... growth mechanism. KEYWORDS. Multi-walled carbon nanotubes, CVD, synthesis, chlorine, benzenes, ethanes. 1. Introduction. Nanotechnology is a topic that is attracting the interest of scientists in ...

  14. Synthesis and characterization of gold nanoparticles incorporated ...

    Indian Academy of Sciences (India)

    Synthesis and characterization of gold nanoparticles incorporated bentonite clay for electrocatalytic sensing of arsenic(III). Pankaj Kumar Rastogi Dharmendra Kumar Yadav Shruti Pandey Vellaichamy Ganesan Piyush Kumar Sonkar Rupali Gupta. Regular Articles Volume 128 Issue 3 March 2016 pp 349-356 ...

  15. Combustion synthesis and preliminary luminescence studies of ...

    Indian Academy of Sciences (India)

    The polycrystalline sample of LiBaPO4 : Tb3+ (LBPT) was successfully synthesized by solution combustion synthesis and studied for its luminescence characteristics. The thermoluminescence (TL) glow curve of LBPT material consists of two peaks at 204.54 and 251.21°C. The optimum concentration was 0.005 mol to ...

  16. Efficient microwave irradiation enhanced stereoselective synthesis ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 122; Issue 4. Efficient microwave irradiation enhanced stereoselective synthesis and antitumor activity of indolylchalcones and their pyrazoline analogs. Magdy A H Zahran Hanan F Salama Yasmin G Abdin Amira M Gamal-Eldeen. Full Papers Volume 122 Issue 4 ...

  17. Synthesis, spectroscopy and supramolecular structures of two ...

    Indian Academy of Sciences (India)

    TECS

    2007-05-16

    May 16, 2007 ... Indian Academy of Sciences. 243. #. Dedicated to Prof. Dr. Werner Weisweiler on the occasion of his 69th birthday. *For correspondence. Synthesis, spectroscopy and supramolecular structures of two magnesium 4-nitrobenzoate complexes. #. BIKSHANDARKOIL R SRINIVASAN,. 1,. * JYOTI V SAWANT,.

  18. Microwave assisted template synthesis of silver nanoparticles

    Indian Academy of Sciences (India)

    Administrator

    Various methods for synthesis, such as conventional temperature as- sisted process, controlled reaction at elevated temperatures, and microwave assisted process have been evalu- ated for the kind of silver nanoparticles synthesized. Starch has been employed as a template and reducing agent. Electron microscopy ...

  19. Spontaneous unscheduled DNA synthesis in human lymphocytes

    International Nuclear Information System (INIS)

    Forell, B.; Myers, L.S. Jr.; Norman, A.

    1979-01-01

    The rate of spontaneous unscheduled DNA synthesis in human lymphocytes was estimated from measurements of tritiated thymidine incorporation into double-stranded DNA (ds-DNA) during incubation of cells in vitro. The contribution of scheduled DNA synthesis to the observed incorporation was reduced by inhibiting replication with hydroxyurea and by separating freshly replicated single-stranded DNA (ss-DNA) from repaired ds-DNA by column chromatography. The residual contribution of scheduled DNA synthesis was estimated by observing effects on thymidine incorporation of: (a) increasing the rate of production of apurinic sites, and alternatively, (b) increasing the number of cells in S-phase. Corrections based on estimates of endogenous pool size were also made. The rate of spontaneous unscheduled DNA synthesis is estimated to be 490 +- 120 thymidine molecules incorporated per cell per hour. These results compare favorably with estimates made from rates of depurination and depyrimidination of DNA, measured in molecular systems if we assume thymidine is incorporated by a short patch mechanism which incorporates an average of four bases per lesion

  20. Supramolecular assembly based on a heteropolyanion: Synthesis ...

    Indian Academy of Sciences (India)

    Unknown

    crystal structure of Na3(H2O)6[Al(OH)6Mo6O18]⋅2H2O. VADDYPALLY SHIVAIAH and SAMAR K DAS*. School of Chemistry, University of Hyderabad, Hyderabad 500 046, India e-mail: skdsc@uohyd.ernet.in. MS received 8 November 2004; revised 25 December 2005. Abstract. Synthesis and structural characterization of ...

  1. Is Glycogenin Essential for Glycogen Synthesis?

    Science.gov (United States)

    Oldfors, Anders

    2017-07-05

    Glycogen synthesis requires a priming oligosaccharide, formed by autoglucosylation of glycogenin, a core protein in glycogen particles. In this edition of Cell Metabolism, Testoni et al. (2017) challenge this generally accepted concept by demonstrating that glycogenin inactivation in mice results in an increased amount of glycogen and not glycogen depletion. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Synthesis of several new carbapenem antibiotics.

    Science.gov (United States)

    Ohtani, M; Watanabe, F; Narisada, M

    1985-05-01

    A synthesis of several carbapenem antibiotics including 9-methoxythienamycin is described. The final deprotection of C-3 esters was accomplished by a novel procedure using aluminum trichloride under a very mild condition. The antibacterial activity against Gram-positive and Gram-negative bacteria is shown.

  3. Synthesis of Trishomocubane Amino Acid Derivatives | Govender ...

    African Journals Online (AJOL)

    The synthesis of four novel trishomocubane amino acid derivatives is described. The hydantoin precursor and bis-Boc protected hydantoin (>95% yield) were previously reported. A mild hydrolysis of the bis-Boc hydantoin with lithium hydroxide at room temperature quantitatively yielded the corresponding novel cage amino ...

  4. Straightforward synthesis of hyperbranched polymer/graphene ...

    Indian Academy of Sciences (India)

    Straightforward synthesis of hyperbranched polymer/graphene nanocomposites from graphite oxide via in situ grafting from approach. QIUHONG XU1, YIWEN GONG1, YUAN FANG2, GUOHUA JIANG1,3,∗. , YIN WANG1,3,. XINKE SUN1,3 and RIJING WANG1,3. 1Department of Materials Engineering, College of Materials ...

  5. Synthesis of ‘unfeasible’ zeolites

    Czech Academy of Sciences Publication Activity Database

    Mazur, Michal; Wheatley, P. S.; Navarro, M.; Roth, Wieslaw Jerzy; Položij, M.; Mayoral, A. M.; Eliášová, Pavla; Nachtigall, P.; Čejka, Jiří; Morris, R. E.

    2016-01-01

    Roč. 8, č. 1 (2016), s. 58-62 ISSN 1755-4330 R&D Projects: GA ČR GBP106/12/G015 EU Projects: European Commission(XE) 604307; European Commission(XE) 312483 Institutional support: RVO:61388955 Keywords : synthesis * transformation * frameworks Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 25.870, year: 2016

  6. Chaos synthesis by means of evolutionary algorithms

    Czech Academy of Sciences Publication Activity Database

    Zelinka, I.; Chen, G.; Čelikovský, Sergej

    2008-01-01

    Roč. 18, č. 4 (2008), s. 911-942 ISSN 0218-1274 R&D Projects: GA ČR(CZ) GA102/08/0186 Institutional research plan: CEZ:AV0Z10750506 Keywords : Chaos * evolution * synthesis Subject RIV: BC - Control Systems Theory Impact factor: 0.870, year: 2008

  7. Synthesis, characterization and photochemistry of a new ...

    Indian Academy of Sciences (India)

    Abstract. The synthesis, crystal structure, redox characteristics and photochemistry of a new heptamolyb- date supported magnesium-aqua coordination complex viz. (hmtH)2[{Mg(H2O)5}2{Mo7O24}]·3H2O 1 (hmt. = hexamethylenetetramine) is reported. The cyclic voltammogram reveals quasireversible redox behaviour.

  8. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    ... nontoxic, safe, biocompatible and environmentally acceptable. In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent ...

  9. ECO-FRIENDLY SYNTHESIS OF SILVER NANOPARTICLES ...

    African Journals Online (AJOL)

    userpc

    thermal and antibacterial properties of silver nanoparticles have made them suitable for many industrial applications as such it is being rated as being amongst the most commercialized metallic nanoparticles. Quite a number of studies have reported either the extracellular or intracellular synthesis of silver nanoparticles ...

  10. Process synthesis and intensification of hybrid separations

    DEFF Research Database (Denmark)

    Errico, Massimiliano

    2017-01-01

    as applied to the separation of biobutanol from its fermentation broth. The synthesis of alternative hybrid flowsheets is reported, showing that one configuration can realize a 43% reduction in the total annual cost. Bioalcohol production by fermentation perfectly represents the casewhere distillation alone...

  11. Synthesis, characterization, antimicrobial activity and molecular ...

    African Journals Online (AJOL)

    Synthesis, characterization, antimicrobial activity and molecular docking studies of combined pyrazol-barbituric acid pharmacophores. Assem Barakat, Bandar M. Al-Qahtani, Abdullah M. Al-Majid, M. Ali Mohammed Rafi Shaik, Mohamed H.M. Al-Agamy, Abdul Wadood ...

  12. Synthesis and characterization of a reduced heteropoly ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 114; Issue 2. Synthesis and characterization of a ... Shivaiah Samar K Das. Inorganic and Analytical Volume 114 Issue 2 April 2002 pp 107-114 ... Compound (1) crystallizes in a cubic space group 3 ¯ , with = 22.2001(6) Å and = 8. The anion [VVO4W 10 VI V 2 ...

  13. Methanol synthesis mechanism over zirconium dioxide

    International Nuclear Information System (INIS)

    Ekerdt, J.G.; Silver, R.G.; Jackson, N.B.

    1986-01-01

    The source and role of oxygen in the formation of carbonates, formate, methoxide, and methanol were studied over zirconia via infrared spectroscopy and /sup 18/O-labeled reactants. The studies are consistent with a formate-to-methoxide mechanism for methanol synthesis and suggest the nature of the active sites involved

  14. MCR synthesis of a tetracyclic tetrazole scaffold

    NARCIS (Netherlands)

    Patil, Pravin; Khoury, Kareem; Herdtweck, Eberhardt; Dömling, Alexander

    2015-01-01

    Scaffold diversity is key in the ongoing exercise of discovery of novel bioactive compounds using high throughput screening (HTS). Based on the Ugi tetrazole synthesis we have designed novel bi- and tri-cyclic scaffolds featuring interesting pharmacophore properties. The compounds of the scaffold

  15. An extended synthesis for evolutionary biology.

    Science.gov (United States)

    Pigliucci, Massimo

    2009-06-01

    Evolutionary theory is undergoing an intense period of discussion and reevaluation. This, contrary to the misleading claims of creationists and other pseudoscientists, is no harbinger of a crisis but rather the opposite: the field is expanding dramatically in terms of both empirical discoveries and new ideas. In this essay I briefly trace the conceptual history of evolutionary theory from Darwinism to neo-Darwinism, and from the Modern Synthesis to what I refer to as the Extended Synthesis, a more inclusive conceptual framework containing among others evo-devo, an expanded theory of heredity, elements of complexity theory, ideas about evolvability, and a reevaluation of levels of selection. I argue that evolutionary biology has never seen a paradigm shift, in the philosophical sense of the term, except when it moved from natural theology to empirical science in the middle of the 19th century. The Extended Synthesis, accordingly, is an expansion of the Modern Synthesis of the 1930s and 1940s, and one that--like its predecessor--will probably take decades to complete.

  16. Hybrid principle with applications to synthesis

    International Nuclear Information System (INIS)

    Nanneh, M.M.

    1991-01-01

    The theory of hybrid principles is presented together with the transformation rule for converting odd-parity approximations into even-parity approximations. This rule leads to a method which provides rigorous upper and lower bounds for the disadvantage factor for a reactor lattice cell. With these bounds very precise benchmarks have been constructed for representative lattices. It is found that a combination of even and odd-parity solutions for the neutron flux is much more efficient than solutions based on either the even-parity or odd-parity. This is the basis of one synthesis scheme. In another synthesis method, a hybrid principle with trial functions for both the even- and odd- parity angular flux is used in conjunction with a classical principle with an odd-parity trial function. The synthesis process is efficient because the largest set of equations to be solved, i.e. the frame work, involves as few as one unknown per node of the finite element mesh. The effectiveness of the synthesis method is demonstrated for a thick shield problem. (author)

  17. Total synthesis of (±)-divanillyltetrahydrofuran ferulate

    Indian Academy of Sciences (India)

    Administrator

    malaria parasite. 9. Two sesquilignans Chushizisins H and I exhibited antioxidant activities against H2O2- induced impairment in PC12 cell. 10. Although many sesquilignans have been found in plants and some showed potent biological activities, only a few have been synthesized. A paper has reported the synthesis.

  18. Synthesis of nanocrystalline fluorinated hydroxyapatite by ...

    Indian Academy of Sciences (India)

    Fluorinated hydroxyapatite, (FHA, Ca10(PO4)6(OH)2-F), possesses higher corrosion resistance in biofluids than pure HA and reduces the risk of dental caries. The present work deals with the synthesis of nanocrystalline FHAs by microwave processing. The crystal size and morphology of the nanopowders were ...

  19. Synthesis, characterization and antimicrobial activity of mixed ...

    African Journals Online (AJOL)

    Synthesis, characterization and antimicrobial activity of mixed ascorbic acid - nicotinamide metal complexes. ... The result of the antimicrobial studies showed that the mixed complexes have higher inhibitory activity than the original ligands against the tested bacteria and fungi species. KEY WORDS: Ascorbic acid, ...

  20. Hydrothermal synthesis, crystal structure and luminescence property ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 12. Hydrothermal synthesis, crystal structure and luminescence property of a three dimensional Sm(III) coordination polymer with 2,5-pyridinedicarboxylic acid. Kranthi Kumar Gangu Anima S Dadhich Saratchandra Babu Mukkamala. Volume 127 Issue 12 ...

  1. Synthesis of the ICT4RED initiative

    CSIR Research Space (South Africa)

    Herselman, M

    2014-12-01

    Full Text Available This section will provide a synthesis of the ICT4RED initiative and will highlight certain important elements of success. It will re-address the aims and objectives which were provided in Section 1 and also address some significant changes which...

  2. synthesis and characterisation of octahydroacridine based ...

    African Journals Online (AJOL)

    DR. AMINU

    refluxing of mesityl imidazole and 4-chlorooctahydroacridine in THF at 90 oC in a pressure tube for two week allowing the synthesis of a ... 2002], it was of interest to form a ligand that would have increased hemilability as well as a ... atmosphere of dry argon or in nitrogen glove box. Glassware were dried overnight in an ...

  3. Combustion synthesis and photoluminescence study of silicate ...

    Indian Academy of Sciences (India)

    Eu2+. Keywords. Biomaterials; silicates; akermanite; combustion synthesis; photoluminescence. 1. Introduction. It is essential to develop biocompatible, bioactive, biore- sorbable and durable materials for orthopaedic and dental implants, that are capable of bearing high stress and loads, and that invoke positive cellular and ...

  4. Synthesis and the Nobel Prize in Chemistry

    Science.gov (United States)

    Seeman, Jeffrey I.

    2017-10-01

    The question often arises as to who may have deserved a Nobel Prize but was not awarded one. Rarely is this discussion extended to who should have received more than one Nobel Prize, but in the field of organic synthesis there are some compelling candidates.

  5. Synthesis, spectroscopic characterization and catalytic oxidation ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 3. Synthesis, spectroscopic characterization and catalytic oxidation properties of ONO/ONS donor Schiff base ruthenium(III) complexes containing PPh3/AsPh3. Priyarega M Muthu Tamizh R Karvembu R Prabhakaran K Natarajan. Volume 123 Issue 3 May ...

  6. Strange matter and Big Bang helium synthesis

    International Nuclear Information System (INIS)

    Madsen, J.; Riisager, K.

    1985-01-01

    Stable strange quark matter produced in the QCD phase transition in the early universe will trap neutrons and repel protons, thus reducing primordial helium production, Ysub(p). For reasonable values of Ysub(p), the radius of strange droplets must exceed 10 -6 cm if strange matter shall solve the dark-matter problem without spoiling Big Bang helium synthesis. (orig.)

  7. Control of Ribosome Synthesis in Escherichia coli

    DEFF Research Database (Denmark)

    Molin, Søren; Meyenburg, K. von; Måløe, O.

    1977-01-01

    The rate of ribosome synthesis and accumulation in Escherichia coli during the transition after an energy source shift-down was analyzed. The shift was imposed on cultures of stringent and relaxed strains growing in glucose minimal medium by the addition of the glucose analogue {alpha...

  8. Biological synthesis and characterization of silver nanoparticles ...

    Indian Academy of Sciences (India)

    eral plant extracts, particularly Lantana camara, Moringa oleifera, Catharanthus roseus, Eucalyptus hybrid, Cassia auriculata.23 However, potential of the plants as biologi- cal materials for the synthesis of nanoparticles is still under exploitation. In the present study, we developed an optimized method for syntheses of silver ...

  9. Nitroketene dithioacetal chemistry: Synthesis of coumarins ...

    Indian Academy of Sciences (India)

    Nitroketene dithioacetals 2, prepared from carbon disul- fide, nitromethane and alkylating agents in a two-step process, are extremely useful two carbon synthons for the synthesis of heterocyclic compounds incorporating diverse functional groups.1 We have been investigat- ing on the alkylation of dipotassium salt of ...

  10. Sulfamides in the synthesis of heterocyclic compounds

    International Nuclear Information System (INIS)

    Gazieva, Galina A; Kravchenko, Angelina N; Lebedev, Oleg V

    2000-01-01

    A comparative analysis of the structures and physicochemical properties of sulfamides and ureas has been performed. New procedures for the synthesis of heterocyclic compounds containing the sulfamide fragment are surveyed and the properties of the resulting compounds are described. The bibliography includes 112 references.

  11. A Computer Program for Organic Synthesis.

    Science.gov (United States)

    Long, Alan K.; And Others

    1983-01-01

    The current organic synthesis program at Harvard University is called the Logic and Heuristics Applied to Synthetic Analysis (LHASA). Discusses this program in detail, focusing on retrosynthetic analysis approach, LHASA hardware, graphical input/perception, strategy control, transform evaluation, and LHASA enhancement. (JN)

  12. Concise Synthesis of Thapsigargin from Nortrilobolide

    DEFF Research Database (Denmark)

    Crestey, François; Toma, Maddalena; Christensen, Søren Brøgger

    2015-01-01

    Herein, we wish to describe for the first time an expedient synthesis of the hexaoxygenated guaianolide thapsigargin (1), a potent inhibitor of the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), from the natural product nortrilobolide (2). This innovative protocol involves three key steps: a one...

  13. Synthesis, characterization and antimicrobial screening of hybrid ...

    Indian Academy of Sciences (India)

    sants.20 Comparative structure of drugs and reported bio-active quinoline derivatives shown in figure 1. As a result of remarkable pharmacological efficiency of quinoline, pyrimidine and morpholine derivatives, our studies have been focused towards the synthesis and bio-evaluation of these derivatives by hybrid approach.

  14. Polyamidoamines as Drug Carriers: Synthesis of Polymers ...

    African Journals Online (AJOL)

    NJD

    The versatile polymerization of bisacrylamides with mono- and difunctional amines, first investigated and greatly expanded in. Ferruti's laboratory,1–3 is utilized in the present project for the synthesis of macromolecular drug carriers. Specifically, we report on the preparation of linear polyamidoamines possessing primary ...

  15. Synthesis, characterization and photochemistry of a new ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 9. Synthesis, characterization and photochemistry of a new heptamolybdate supported magnesium-aqua coordination complex. Savita S Khandolkar Pallepogu Raghavaiah Bikshandarkoil R Srinivasan. Volume 127 Issue 9 September 2015 pp 1581-1588 ...

  16. DNA Assisted Synthesis of Chitosan/ α

    Indian Academy of Sciences (India)

    68

    nitrate, sodium hydroxide and DNA powder were obtained from MERCK and Chitosan was obtained from Matsyafed chitin and Chitosan plant Neendakara Kollam. 2.1 Synthesis of α-Fe2O3 (FD)Nanoparticles. Hematite nanoparticles were prepared by arrested co-precipitation method using ferric nitrate, sodium hydroxide ...

  17. Hydrothermal synthesis and electrochemical properties of a ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 128; Issue 5. Hydrothermal synthesis and electrochemical properties of a coordination polymer based on dinuclear (Pyrazinyl tetrazolate) Copper(II) cations and βOctamolybdate Anions. SHAOBIN LI LI ZHANG HUIYUAN MA HAIJUN PANG. Regular Article Volume ...

  18. A different approach to enantioselective organic synthesis

    DEFF Research Database (Denmark)

    Lennartson, Anders; Olsson, Susanne; Sundberg, Jonas

    2009-01-01

    Voilà, optical activity: Both enantiomers of 1-chloroindene have been synthesized in high selectivity from solely achiral starting materials, and without using optically active catalysts (see scheme). These symmetry-breaking syntheses provide a proof-of-concept for a new approach to asymmetric sy...... synthesis. NCS=N-chlorosuccinimide....

  19. Speech Synthesis Applied to Language Teaching.

    Science.gov (United States)

    Sherwood, Bruce

    1981-01-01

    The experimental addition of speech output to computer-based Esperanto lessons using speech synthesized from text is described. Because of Esperanto's phonetic spelling and simple rhythm, it is particularly easy to describe the mechanisms of Esperanto synthesis. Attention is directed to how the text-to-speech conversion is performed and the ways…

  20. HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF A ...

    African Journals Online (AJOL)

    Preferred Customer

    HYDROTHERMAL SYNTHESIS AND CHARACTERIZATION OF A BINUCLEAR. COMPLEX AND A COORDINATION POLYMER OF COPPER(II). Masoumeh Tabatabaee1*, Reza Mohamadinasab1, Kazem Ghaini1 and Hamid Reza Khavasi2. 1Department of Chemistry, Islamic Azad University, Yazd Branch, Yazd, Iran.

  1. Magnetically retrievable catalysts for organic synthesis

    Science.gov (United States)

    The use of magnetic nanoparticles (MNPs) as a catalyst in organic synthesis has become a subject of intense investigation. The recovery of expensive catalysts after catalytic reaction and reusing it without losing its activity is an important feature in the sustainable process de...

  2. Superheavy nuclei – cold synthesis and structure

    Indian Academy of Sciences (India)

    Abstract. The quantum mechanical fragmentation theory (QMFT), given for the cold synthesis of new and superheavy elements, is reviewed and the use of radioactive nuclear beams (RNB) and targets (RNT) is discussed. The QMFT is a complete theory of cold nuclear phenomena, namely, the cold fission, cold fusion and ...

  3. A Synthesis-Oriented VHDL Course

    Science.gov (United States)

    d'Amore, Roberto

    2010-01-01

    This article proposes a VHDL language course that establishes a strong correlation between the language statements and their use in circuit synthesis. Two course modules are described: a basic module that contains the essential concepts of the language, sufficient for students to describe medium complexity circuits, followed by a second module…

  4. Synthesis, spectroscopic characterization and catalytic oxidation ...

    Indian Academy of Sciences (India)

    Oxidation of alcohols to carbonyl compounds is one of the most pivotal functional group transformations in organic synthesis. Three important natural enzymes ..... 6. Benzyl alcohol. Benzaldehyde. 57. 1-Phenylethanol. Acetophenone. 65. Cyclohexanol. Cyclohexanone. 49 a Reaction time, 5 h. b Yields based on substrate.

  5. Synthesis of novel spiro-β-lactams

    Indian Academy of Sciences (India)

    Administrator

    Since β-lactam antibiotics are a group of drugs of unparallel importance in chemotherapy, consider- able efforts have been made in the development of novel and biologically more active compounds. The search for improved antibiotics also includes design- ing of new methodology for the total synthesis as well as the ...

  6. Synthesis, characterizations and applications of some nanomaterials

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 65; Issue 4. Synthesis, characterizations and applications of some nanomaterials (TiO2 and SiC nanostructured films, organized CNT structures, ZnO structures and CNT{blood platelet clusters). O N Srivastava A Srivastava D Dash D P Singh R M Yadava P R Mishra J ...

  7. Synthesis, characterization and photoluminescence properties of ...

    Indian Academy of Sciences (India)

    Synthesis of a new nano hybrid of 5,10,15,20-mesotetra(4-aminophenyl) porphyrin (TAP) functionalized with multi-walled carbon nanotubes (MWCNTs) through an amide linkage is reported for the first time. ThisMWCNT-TAP hybrid was characterized by Raman, Fourier transform infrared (FT-IR), Transmissionelectron ...

  8. Hydroxyapatite, a biomaterial: Its chemical synthesis ...

    Indian Academy of Sciences (India)

    Hydroxyapatite, a biomaterial: Its chemical synthesis, characterization and study of biocompatibility prepared from shell of garden snail,. Helix aspersa. ANJUVAN SINGH. Department of Biotechnology and Biosciences, Lovely Professional University, Phagwara 144 411, India. MS received 10 February 2010; revised 20 July ...

  9. Translesion synthesis : cellular and organismal functions

    NARCIS (Netherlands)

    Temviriyanukul, Piya

    2014-01-01

    To cope with DNA damages induced by endogenous and exogenous agents, cells employ both DNA repair and DNA damage tolerance (DDT) mechanisms. Translesion synthesis (TLS) is an important DDT mechanism in mammalian cells. Mammalian TLS is performed by at least five key proteins. These TLS DNA

  10. Synthesis of (/sup 3/H) Zolpidem

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.; Parent, G.; Tizot, A.

    1986-08-01

    Zolpidem is a novel hypnotic agent possessing a substituted imidazo (1,2-a) pyridine structure. The synthesis of the tritium labelled compound with a specific activity of 60.5 Ci/mmol is described. This new radioligand was initially used to establish and characterize the binding properties of Zolpidem in the rat brain.

  11. Synthesis of (/sup 14/C)Zolpidem

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J.; Tizot, A.

    1986-04-01

    The synthesis of (/sup 14/C)Zolpidem, a new hypnotic agent having a non-benzodiazepine structure, is described. This compound was synthesised in a 64% overall radiochemical yield from potassium (/sup 14/C)cyanide and with a specific radioactivity of 56 mCi/mmol. It was used for pharmacokinetic and drug metabolism studies.

  12. Synthesis of (+)-Antroquinonol: An Antihyperglycemic Agent.

    Science.gov (United States)

    Sulake, Rohidas S; Lin, Hsiao-Han; Hsu, Chia-Yu; Weng, Ching-Feng; Chen, Chinpiao

    2015-06-19

    The total synthesis of antroquinonol has been accomplished through Suzuki-Miyaura cross-coupling and Barton-McCombie reaction, and the α,β-unsaturation was achieved through selenylation and oxidation protocols. In vitro and in vivo studies on the glucose-lowering properties of antroquinonol indicate that it is a potential antidiabetic agent.

  13. Green Synthesis of a Fluorescent Natural Product

    Science.gov (United States)

    Young, Douglas M.; Welker, Jacob J. C.; Doxsee, Kenneth M.

    2011-01-01

    Synthesis of 4-methylumbelliferone via the acid-catalyzed Pechmann condensation introduces students to several types of organic reactions: transesterification, electrophilic aromatic substitution, and alcohol dehydration. Performed with a recyclable, solid catalyst and under solvent-free conditions, the experiment illustrates many of the…

  14. Room temperature synthesis of biodiesel using sulfonated ...

    Science.gov (United States)

    Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature. Prepared for submission to Royal Society of Chemistry (RSC) journal, Green Chemistry as a communication.

  15. Synthesis, spectral, thermal, optical dispersion and dielectric ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Bulletin of Materials Science; Volume 39; Issue 1. Synthesis, spectral, thermal, optical dispersion and dielectric properties of nanocrystalline dimer complex (PEPyr–diCd) thin films as novel organic semiconductor. Ahmed Farouk Al-Hossainy. Volume 39 Issue 1 February 2016 pp 209-222 ...

  16. Design, synthesis and computational validation of novel ...

    Indian Academy of Sciences (India)

    Abstract. The design and synthesis of benzimidazolyl and indolyl linked α-alkoxy phenylpropanoic acid derivatives and the β-keto ester analogues in an effort to develop novel peroxisome proliferator activated recep- tors ligands expected to exhibit PPARα and PPARγ partial agonism in the management of hyperglycemia.

  17. Synthesis, stabilization, and characterization of metal nanoparticles

    Science.gov (United States)

    White, Gregory Von, II

    Wet chemical synthesis techniques offer the ability to control various nanoparticle characteristics including size, shape, dispersibility in both aqueous and organic solvents, and tailored surface chemistries appropriate for different applications. Large quantities of stabilizing ligands or surfactants are often required during synthesis to achieve these nanoparticle characteristics. Unfortunately, excess reaction byproducts, surfactants, and ligands remaining in solution after nanoparticle synthesis can impede application, and therefore post-synthesis purification must be employed. A liquid-liquid solvent/antisolvent pair (typically ethanol/toluene or ethanol/hexane for gold nanoparticles, GNPs) can be used to both purify and size-selectively fractionate hydrophobically modified nanoparticles. Alternatively, carbon dioxide may be used in place of a liquid antisolvent, a "green" approach, enabling both nanoparticle purification and size-selective fractionation while simultaneously eliminating mixed solvent waste and allowing solvent recycle. We have used small-angle neutron scattering (SANS) to investigate the ligand structure and composition response of alkanethiol modified gold and silver nanoparticles at varying anti-solvent conditions (CO2 or ethanol). The ligand lengths and ligand solvation for alkanethiol gold and silver NPs were found to decrease with increased antisolvent concentrations directly impacting their dispersibility in solution. Calculated Flory-Huggins interaction parameters support our SANS study for dodecanethiol dispersibility in the mixed organic solvents. This research has led to a greater understanding of the liquid-liquid precipitation process for metal nanoparticles, and provides critical results for future interaction energy modeling.

  18. Microwave Assisted Synthesis and Photoluminescence Properties of ...

    Indian Academy of Sciences (India)

    46

    Microwave Assisted Synthesis and Photoluminescence Properties of. ZnS:Pb2+ Nanophosphor for Solid State Lighting. D.N.Game1*, C.B. Palan3, N.B.Ingale2 and S.K.Omanwar3. 1Cusrow Wadia Institute of Technology, Pune, India. 2 Prof. Ram Meghe Institute of Technology and Research, Badnera, Amravati, India.

  19. SYNTHESIS OF MCM-41 NANOMATERIAL FROM ALGERIAN ...

    African Journals Online (AJOL)

    T. Ali-Dahmane

    1 mai 2017 ... Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0. International License. Libraries Resource Directory. We are listed under Research Associations category. SYNTHESIS OF MCM-41 NANOMATERIAL FROM ALGERIAN BENTONITE:.

  20. SHORT COMMUNICATION SYNTHESIS OF TRIBUTYL CITRATE ...

    African Journals Online (AJOL)

    Preferred Customer

    It is a plasticizer permitted in the field of food additives, food contact materials and medical products and is widely used in cosmetics [2] and biodegradable polymers [3]. Moreover, TBC is an environmentally, friendly plasticizer because the materials used for synthesis are available from renewable resources by fermentation.

  1. Dynamic analysis of pipings by Modal Synthesis

    International Nuclear Information System (INIS)

    Augusto, O.B.; Mattar Neto, M.

    1986-01-01

    A Modal Synthesis method, the component modes, and its implementation as a post-processor of finite element program is presented. Examples of calculations of stationary and transient vibrations for monitoring pipelines of nuclear power plants are analysed. (M.C.K.) [pt

  2. Synthesis, characterization and electrochemical performance of ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 6. Synthesis, characterization and electrochemical performance of Li 2 Ni x Fe 1 − x SiO 4 cathode materials for lithium ion batteries. A Y SHENOUDA M M S SANAD. Volume 40 Issue 6 October 2017 pp 1055-1060 ...

  3. Synthesis, characterization and antibacterial evaluation of ...

    African Journals Online (AJOL)

    The synthesis, characterization and anti-bacterial evaluation of two palmitoyl amino acids is reported in this work. The reported antimicrobial activity of some fatty acid derivatives encouraged the investigation of the possible influence of an aromatic group substituent on a saturated fatty acid residue. The compounds were ...

  4. Efficient and convenient synthesis of symmetrical carboxylic ...

    African Journals Online (AJOL)

    An efficient and convenient procedure for the synthesis of symmetrical carboxylic anhydrides from carboxylic acids with sulfated zirconia by PEG-1000 phase transfer catalysis has been developed. The reactions proceeded under mild and solvent-free conditions to provide the carboxylic anhydrides in good to excellent ...

  5. Synthesis of dehydrobenzoannulenes with pyrene core

    Indian Academy of Sciences (India)

    Synthesis of polyacetylene precursors. 17 and 20 for DBAs 10 and 11, respectively, was ham- pered due to incomplete elimination of 16 and 19 under a variety of conditions and also presumably due to the instability of polyacetylenic derivatives 17 and 20 under reaction and ambient conditions. Acknowledgements.

  6. ASAM: Automatic architecture synthesis and application mapping

    DEFF Research Database (Denmark)

    Jozwiak, Lech; Lindwer, Menno; Corvino, Rosilde

    2013-01-01

    This paper focuses on mastering the automatic architecture synthesis and application mapping for heterogeneous massively-parallel MPSoCs based on customizable application-specific instruction-set processors (ASIPs). It presents an overview of the research being currently performed in the scope...

  7. Synthesis, crystal structure, thermal analysis and dielectric

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 39; Issue 5. Synthesis, crystal structure, thermal analysis and dielectric properties of two mixed trichlorocadmiates (II).

  8. Synthesis, Characterization and Application of Nano Lepidocrocite ...

    African Journals Online (AJOL)

    NICO

    were finely ground with a pestle in an agate mortar and were stored in an airtight bottle. 2.3. Synthesis of Magnetite (Fe3O4) Nanoparticles. Fe3O4 nanoparticles were synthesized in a similar fashion as mentioned for FeOOH except that the washing was done 3–4. RESEARCH ARTICLE. A. Agarwal, H. Joshi and A. Kumar,.

  9. Synthesis and characterization of silver molybdate nanowires ...

    Indian Academy of Sciences (India)

    Wintec

    approaches have been proved to provide an alternative route for the synthesis of 1-D nanomaterials (Buhro et al ... magnetic stirring to form a homogeneous greenish-yellow precipitate. The resulting precipitate was ... the size-dependent optical properties of the nanomaterials, due to the quantum confinements of the photo- ...

  10. Synthesis and Characterisation of Aluminophosphate Molecular Sieves

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, E.N.

    1996-02-01

    Catalysts are very important in petrochemical processes. One of the properties that make crystalline, microporous materials attractive for catalytic purposes is their well-defined structure and ability to act as shape selective catalysts. This doctoral thesis presents the synthesis and characterization of a number of crystalline, microporous aluminophosphates and silicoaluminophosphates. 99 refs., 50 figs., 12 tabs.

  11. SUPPLEMENTARY INFORMATION (SI) Synthesis and comparing ...

    Indian Academy of Sciences (India)

    Synthesis and comparing the antibacterial activities of pyrimidine derivatives. ANDREWS B*,a,b, KOMATHI Kb and MOHAN Sb. aPG and Research Department of Chemistry, Islamiah College, Vaniyambadi 635 752, India. Affiliated to Thiruvalluvar University, Vellore, Tamil Nadu, India. bPriyadarshini Engineering College, ...

  12. Synthesis, characterizations and applications of some ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 65; Issue 4. Synthesis, characterizations and applications of some nanomaterials (TiO2 and SiC nanostructured films, organized CNT structures, ZnO structures and CNT{blood platelet clusters). O N Srivastava A Srivastava D Dash D P Singh R M Yadava P R Mishra J ...

  13. Solvent-Free Synthesis of Chalcones

    Science.gov (United States)

    Palleros, Daniel R.

    2004-01-01

    The synthesis of twenty different chalcones in the absence of solvent is presented. The results indicated that out of the twenty different chalcones investigated seventeen can be obtained in a matter of minutes by mixing the corresponding benzaldehyde and acetophenone in the presence of solid NaOH in a mortar with pestle.

  14. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  15. Synthesis of pterostilbene by Julie Olefination

    Science.gov (United States)

    A simple, stereoselective route for the synthesis of the biologically active compounds trans-pterostilbene and tetramethoxy stilbene from the readily available starting materials 3,5-dimethoxy benzyl alcohol and 4-hydroxy benzaldehyde was developed using Julia olefination as a key reaction....

  16. Synthesis of 7-dehydrocholesterol through hexacarbonyl ...

    African Journals Online (AJOL)

    Synthesis of 7-dehydrocholesterol through hexacarbonyl molybdenum catalyzed elimination reaction. ... Bulletin of the Chemical Society of Ethiopia ... molybdenum catalyzed elimination reaction of the allylic acetates has been improved by the presence of O,N-bis(trimethylsilyl) acetamide in the reaction medium.

  17. Efficient synthesis of phosphonodepsipeptides derived from norleucine

    Czech Academy of Sciences Publication Activity Database

    Pícha, Jan; Buděšínský, Miloš; Hančlová, Ivona; Šanda, Miloslav; Fiedler, Pavel; Vaněk, Václav; Jiráček, Jiří

    2009-01-01

    Roč. 65, č. 31 (2009), s. 6090-6103 ISSN 0040-4020 R&D Projects: GA ČR GA203/06/1405; GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z40550506 Keywords : phosphonate * pseudopeptide * inhibitor * synthesis * norleucine Subject RIV: CC - Organic Chemistry Impact factor: 3.219, year: 2009

  18. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    Unknown

    disposal or to minimize the environmental impact. One of the approaches is the conversion of fly ash to zeolites, which have wide applications in ion exchange, as mole- cular sieves, catalysts, and adsorbents (Breck 1974). The present study is concerned with the synthesis of zeolite from coal fly ash and its characterization ...

  19. Controlled synthesis and electrochemical properties of vanadium ...

    Indian Academy of Sciences (India)

    Vanadium oxides; nanostructured materials; chemical synthesis; electrochemical property; VO2(M). 1. Introduction. In the past decade, much attention has been paid on low dimensional nanomaterials with novel morphologies includ- ing nanobelts, nanotubes, nanowires, nanosheets, etc. They exhibit specific physical and ...

  20. Location-dependent optimal biorefinery synthesis

    DEFF Research Database (Denmark)

    Bertran, Maria-Ona; Woodley, John M.; Gani, Rafiqul

    2017-01-01

    In this paper, we present an extended framework for synthesis of biorefinery networks. The extension of the framework responds to the needs of: automatically generating problem-specific superstructures from an in-house database in an efficient and reliable way, as well as obtaining and analysing...

  1. Approaches to chemical synthesis of pectic oligosaccharides

    DEFF Research Database (Denmark)

    Nepogodiev, Sergei A.; Field, Robert A.; Damager, Iben

    2011-01-01

    at the formation of specific glycosidic linkages as they are present in the target oligosaccharides. Challenges in synthesis of pectic oligosaccharides are associated with often poor stereoselectivity of glycosylation reactions between GA and GD, in particular for the construction of 1,2-cis-glycosidic linkages...

  2. Synthesis of azaphenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Hansen, Henriette Møller; Lysén, M.; Begtrup, M.

    2005-01-01

    A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

  3. Synthesis and pharmaceutical importance of 2-azetidinone ...

    Indian Academy of Sciences (India)

    633–637. c Indian Academy of Sciences. Synthesis and pharmaceutical importance of 2-azetidinone derivatives of phenothiazine. RITU SHARMA, PUSHKAL SAMADHIYA. ∗. , S D SRIVASTAVA and S K SRIVASTAVA. Synthetic Organic Chemistry Laboratory, Department of Chemistry, Dr. H S Gour University (A Central.

  4. Combustion synthesis and preliminary luminescence studies of ...

    Indian Academy of Sciences (India)

    bustion synthesis and studied for its luminescence characteristics. The thermoluminescence (TL) glow curve of. LBPT material consists of two peaks at 204.54 and 251.21◦C. The optimum concentration was 0.005 mol to obtain the higher TL intensity compared to commercial TLD-100 phosphor. The peak shape method was ...

  5. Selectivity of lipases for estolides synthesis

    NARCIS (Netherlands)

    Todea, Anamaria; Frissen, A.E.; Otten, Linda G.; Arends, I.; Peter, F.; Boeriu, C.G.

    2015-01-01

    Lipase-catalyzed synthesis of estolides starting from different saturated (C16 16OH, C18 12OH) and unsaturated (C18:1 9 cis 12-OH) hydroxy-fatty acids was investigated. For this reason, the catalytic efficiency of several native and immobilized lipases in different organic reaction media at

  6. Combustion synthesis and preliminary luminescence studies of ...

    Indian Academy of Sciences (India)

    6, October 2015, pp. 1527–1531. c Indian Academy of Sciences. Combustion synthesis and preliminary luminescence studies of. LiBaPO4 : Tb. 3+ phosphor. C B PALAN1,∗, N S BAJAJ1, ... MS received 28 April 2015; accepted 8 June 2015. Abstract. ... In CW-OSL mode its sensitivity for beta expo- sure was found to be ...

  7. An introduction to statistical parametric speech synthesis

    Indian Academy of Sciences (India)

    in speech synthesis by listening tests, depends critically on choosing an appropriate configu- ration. The two most important aspects of this configuration are the parameterization of the speech signal (the 'observations' of the model, in HMM terminology) and the choice of mod- elling unit. Since the modelling unit is typically ...

  8. Synthesis of 14C-dehydrocorydaline chloride

    International Nuclear Information System (INIS)

    Zhang Rui; Wang Ding

    1988-01-01

    A method for synthesis of 14 C-dehydrocorydaline chloride is described. In the presence of sodium hydroxide, acetonylpalmatine is reacted with 14 C-methyl iodide in sealed glass ampoule to give 14 C-13-methylpalmatine iodide which is then converted to chloride. The radiochemical purity of 14 C-dehydrocorydaline determined by TLC is over 98% and the labelling efficiency is 54%

  9. Two synthesis methods based on cepstral parametrization

    Czech Academy of Sciences Publication Activity Database

    Přibil, Jiří; Madlová, A.

    2002-01-01

    Roč. 11, č. 2 (2002), s. 35-39 ISSN 1210-2512 R&D Projects: GA MŠk OC 258.10; GA ČR GV102/96/K087 Institutional research plan: CEZ:AV0Z2067918 Keywords : speech processing * speech synthesis * signal processing Subject RIV: JD - Computer Applications, Robotics

  10. Synthesis and electrochemical studies of phenylazo substituted ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 6. Synthesis and electrochemical studies of phenylazo substituted tetraaza macrocyclic complexes of Ni(II). Randhir Singh Suresh Kumar Amarendra Bhattacharya. Inorganic and Analytical Volume 112 Issue 6 December 2000 pp 601-605 ...

  11. Methods of synthesis of deuterium labelled lipids

    International Nuclear Information System (INIS)

    Bragina, N.A.; Chupin, V.V.

    1997-01-01

    Methods for synthesis of deuterium-labelled hydrophobic and hydrophilic lipid molecules and ways of obtaining selectively and completely deuterized phospholipids and their analogues are considered. The deuterium-labelled lipids are used for studies on structural organization and functioning of biological membranes, including studies with the NMP and neutron-diffraction methods of lipid-lipid and lipid-protein interactions

  12. Synthesis, spectroscopic characterization and catalytic oxidation ...

    Indian Academy of Sciences (India)

    tion in the development of catalysis, magnetism, molec- ular architectures and materials chemistry. Oxidation of alcohols to carbonyl compounds is one of the most pivotal functional group transformations in organic synthesis. Three important natural enzymes used for oxidation reactions are cytochrome P-450, per- oxidases ...

  13. Actionable climate knowledge: from analysis to synthesis

    NARCIS (Netherlands)

    Meinke, H.B.; Nelson, R.; Kokic, P.; Stone, R.; Selvaraju, R.; Baethgen, W.

    2006-01-01

    The traditional reductionist approach to science has a tendency to create `islands of knowledge in a sea of ignorance¿, with a much stronger focus on analysis of scientific inputs rather than synthesis of socially relevant outcomes. This might be the principal reason why intended end users of

  14. Microfibrous Matrices: Optimization of Synthesis Conditions

    Directory of Open Access Journals (Sweden)

    Amogh N. Karwa

    2012-01-01

    Full Text Available This study focuses on the process of optimization for carbon nanofiber synthesis at the exterior and the interior of 3-dimensional sintered nickel microfibrous networks. Synthesis of carbon nanofibers (CNF by catalytic decomposition of acetylene (ethyne was conducted at atmospheric pressure and short reaction times (10 min. Two factors evaluated during the study were (a CNF quality (observed by SEM and Raman spectroscopy and (b rate of reaction (gravimetrically measured carbon yield. Independent optimization variables included redox faceting pretreatment of nickel, synthesis temperature, and gas composition. Faceting resulted in an 8-fold increase in the carbon yield compared to an untreated substrate. Synthesis with varying levels of hydrogen maximized the carbon yield (9.31 mg C/cm2 catalyst. The quality of CNF was enhanced via a reduction in amorphous carbon that resulted from the addition of 20% ammonia. Optimized growth conditions that led to high rates of CNF deposition preferentially deposited this carbon at the exterior layer of the nickel microfibrous networks (570°C, 78% H2, 20% NH3, 2% C2H2, faceted Ni.. CNF growth within the 3-dimensional nickel networks was accomplished at the conditions selected to lower the gravimetric reaction rate (470°C, 10% H2, 88% N2, 2% C2H2, nonfaceted Ni.

  15. Ammonia synthesis from first principles calculations

    DEFF Research Database (Denmark)

    Honkala, Johanna Karoliina; Hellman, Anders; Remediakis, Ioannis

    2005-01-01

    The rate of ammonia synthesis over a nanoparticle ruthenium catalyst can be calculated directly on the basis of a quantum chemical treatment of the problem using density functional theory. We compared the results to measured rates over a ruthenium catalyst supported on magnesium aluminum spinet...

  16. Green synthesis of silver nanoparticles and biopolymer ...

    Indian Academy of Sciences (India)

    2018-03-29

    Mar 29, 2018 ... Recent trends in developing green-triggered technologies for the nanoma- terial synthesis portray the enormous importance in material science and technology, also considerable status attributed to a wide variety of ... also other organic nutrients that make it ideal for keeping good health. In addition ...

  17. Synthesis of fluorescent diblock copolymer nanoparticle supported ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... PCL is reviewed in this paper. In 2005, PCL-based liquid crys- talline DBC was synthesized and characterized thoroughly. [3]. A RAFT technique was adopted for the synthesis of PCL- based DBC [4]. A DBC between PCL and MMA was prepared by living ring opening polymerization (ROP) method [5].

  18. Organosilicon Reagents in Natural Product Synthesis

    Indian Academy of Sciences (India)

    Product Synthesis. Hari Prasad S teaches post graduate students medicinal organic chemistry and organic spectroscopy at the. Chemistry Department, ..... Structure 2. P.'-NH2. OH. KF/HCI/MeOH. JJ~. B~ H~ .. Tf = tli fluoromethane sui tonate. Nap = naphthyl. (R)-Isoprotcrenol. The silyl enol ethers undergo reaction with ...

  19. Gene Synthesis with H G Khorana

    Indian Academy of Sciences (India)

    IAS Admin

    Why synthesize genes? Because of the naiveté of biologists and molecular biologists in 1965 when Gobind Khorana initiated synthesis of the yeast alanine tRNA gene, this was a valid question. At that time, we could deduce the sequence of only one gene – the yeast alanine tRNA gene as the corresponding tRNA.

  20. Guided Synthesis of Control Programs Using UPPAAL

    DEFF Research Database (Denmark)

    Hune, T.; Larsen, Kim Guldstrand; Pettersson, P.

    2000-01-01

    the transitions with extra guards. Applying this technique have made synthesis of control programs feasible for a plant producing as many as 60 batches. In comparison, we could only handle plants producing two batches without using guides. The synthesized control programs have been executed in a physical plant...

  1. Superheavy nuclei–cold synthesis and structure

    Indian Academy of Sciences (India)

    The quantum mechanical fragmentation theory (QMFT), given for the cold synthesis of new and superheavy elements, is reviewed and the use of radioactive nuclear beams (RNB) and targets (RNT) is discussed. The QMFT is a complete theory of cold nuclear phenomena, namely, the cold fission, cold fusion and cluster ...

  2. Synthesis, Characterization and Antibacterial Evaluations of the ...

    African Journals Online (AJOL)

    MBI

    2014-06-05

    Jun 5, 2014 ... 39. Synthesis, Characterization and Antibacterial Evaluations of the Schiff. Base 2-(1-(2-(Piperazin-1-yl)ethylimino)ethyl)Phenol and its Complexes of. Mn(II), Ni(II) and Zn(II). Salga, M. S., Sada, I. and Abdullahi, A. Department of Pure and Industrial Chemistry, Umaru Musa 'Yar Adua University, Katsina.

  3. synthesis, characterization, thermal behavior and antimicrobial

    African Journals Online (AJOL)

    The present work deals with the synthesis and characterization of Co, Ni, Cd, Zn and Cu(II) complexes of 3-methyl benzoic acid with/without hydrazine. EXPERIMENTAL. The chemicals and solvents used were of AR grade received from Fluka Chemicals. The double distilled water was used for the preparation and chemical ...

  4. Synthesis, Characterization and Antimicrobial Activities of Some ...

    African Journals Online (AJOL)

    user

    of metal ions with vitamin.111: Synthesis and infrared spectra of metal complexes with pyridoxamine and pyridoxine. Inorg. Chim. Acta, 46, 191-197. Gary, J and Adeyemo, A (1981) Interaction of vitamin B1 with Zn(II), Cd (II) and Hg(II) in. Deuterated Dimethyl Sulfoxide. Inorg. Chim. Acta, 55, 93-98. Gohzalez-vergara, E ...

  5. Synthesis, Spectroscopic and Pharmacological Studies of Bivalent ...

    African Journals Online (AJOL)

    NICO

    Synthesis, Spectroscopic and Pharmacological Studies of. Bivalent Copper, Zinc and Mercury Complexes of Thiourea. Shikha Parmar*, Yatendra Kumar and Ashu Mittal. I.T.S Paramedical College (Pharmacy), Delhi Meerut Road, Muradnagar, Ghaziabad 201206, India. Received 4 June 2010, revised 14 June 2010, ...

  6. Green Synthesis of Nanomaterials: Environmental Aspects

    Science.gov (United States)

    There is always a search for reliable and environmentally friendly processes to manufacture metal and metal oxide nanoparticles minimizing or even eliminating the use of hazardous chemicals. The only way to develop these “green” processes is to adapt benign synthesis approaches t...

  7. Room temperature synthesis of colloidal platinum nanoparticles

    Indian Academy of Sciences (India)

    Unknown

    1988) and application also in optical, electronic and mag- netic devices (Schon and Simon 1995). The catalytic reacti- vity depend on size and shape of nanoparticles and therefore synthesis of controlled shapes and size of colloidal platinum particles could be critical for these applications. Nanostructured materials promise ...

  8. Synthesis of functionalized pyrazolopyran derivatives: comparison of ...

    Indian Academy of Sciences (India)

    Administrator

    added to the reaction mixture and the contents of the flask stirred for about 1 h. The solid precipitate was sub- jected to a similar work up as in method A. Figure 3. Intermediate Knoevenagel condensation product 2. 2.1c Method C (MVA synthesis): The reactants were added in the microwave in a similar fashion as in method.

  9. Gene Synthesis with H G Khorana

    Indian Academy of Sciences (India)

    IAS Admin

    National Medal of Science. (2006). His research interests include the chemical synthesis of the nucleic acids and their analogs as well as the biological and biochemical properties of DNA and. RNA. “I wish to conclude by hazarding the following rather long range predictions. In the years ahead, genes are going to be.

  10. Synthesis, characterisation, nuclease and cytotoxic activity of ...

    Indian Academy of Sciences (India)

    GULZAR A BHAT

    2018-02-07

    Feb 7, 2018 ... Synthesis, characterisation, nuclease and cytotoxic activity of phosphate-free and phosphate-containing copper. 4 -(N-methylpyridinium)-2,2 :6 ,2 terpyridine complexes. GULZAR A BHATa, RAIHANA MAQBOOLb and RAMASWAMY MURUGAVELa,∗. aDepartment of Chemistry, Indian Institute of ...

  11. SYNTHESIS AND ANTIBACTERIAL EVALUATION OF SOME ...

    African Journals Online (AJOL)

    General procedure for the synthesis of Mannich Bases (III-V). Benzimidazolylthioacetic acid. (II) (0.002 mol) dissolved in ethanol and 3-4 drops of conc. HCl was added and reaction mixture was kept for stirring. To the stirring reaction mixture, formaldehyde (0.002 mol) was added drop wise and stirring was continued for 10 ...

  12. Supramolecular assembly based on a heteropolyanion: Synthesis ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 117; Issue 3. Supramolecular assembly based on a heteropolyanion: Synthesis and crystal structure of Na3(H2O)6[Al(OH)6Mo6O18] ⋅ 2H2O. Vaddypally Shivaiah Samar K Das. Volume 117 Issue 3 May 2005 pp 227-233 ...

  13. Synthesis, properties and supramolecular structure of ...

    Indian Academy of Sciences (India)

    Synthesis, properties and supramolecular structure of piperazinediium thiosulfate monohydrate. +. BIKSHANDARKOIL R SRINIVASANa*, ASHISH R NAIKa. , SUNDER N DHURIa. ,. CHRISTIAN NÄTHERb and WOLFGANG BENSCHb. aDepartment of Chemistry, Goa University, Goa 403 206, India. bInstitut für ...

  14. Templated, carbothermal reduction synthesis of mesoporous silicon ...

    Indian Academy of Sciences (India)

    2018-02-05

    Feb 5, 2018 ... 1Center for Electrochemical Science and Engineering, Department of Chemical and Biological Engineering, Illinois. Institute of Technology, Chicago 60616, .... Schematic diagram of mesoporous silica shell synthesis on the CNT surface using self-assembly method. of the silica shell. The composition of Si ...

  15. Synthesis and electrochemical studies of phenylazo substituted ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Synthesis and characterization of some phenyl azo substituted tetraaza macrocyclic complexes of Ni(II) are reported. Electrochemical behaviour of these macrocyclic complexes has been examined using polarographic, voltammetric and spectroscopic techniques. These studies show that both the ligand and the ...

  16. Synthesis and characterization of a reduced heteropoly ...

    Indian Academy of Sciences (India)

    Pope and Flynn reported a series of such compounds of the general formula VtVnW12−n. −+. )3(. 40. O n. (where Vt is the vanadium in the center of the tertrahedron, n = 2, 3, 4)5,6. The synthesis and characterization of these heteropolytungstovanadates have been described many years ago, but the reduced analogue of ...

  17. Synthesis and testing of nanosized zeolite Y

    Science.gov (United States)

    Karami, Davood

    This work focuses on the synthesis and testing of nanosized zeolite Y. The synthesis formulations of faujasite-type structure of zeolite Y prepared in nanosized form are described. The synthetic zeolite Y is the most widely employed for the preparation of fluid catalytic cracking (FCC) catalysts. The synthesis of zeolite Y is very complicated process. The mean particle size of zeolite Y is 1800 nm. The major challenge of this work involved reducing this average particle size to less than 500 nm. The preliminary experiments were conducted to obtain the pure zeolite Y using the soluble silicates as a silica source. This was achieved by applying the experimental design approach to study the effects of many parameters. The ageing time turned out to be the most significant variable affecting product purity. Based on the preliminary results, a detailed investigation was carried out to determine the effects of silica-alumina precursor preparations on zeolite Y synthesis. Aluminosilicate precursors were prepared by gelling and precipitation of soluble silicate. The as-prepared precursors were used for the hydrothermal synthesis of zeolite Y. The procedure of the precipitation of soluble silicate yielded pure zeolite Y at the conventional synthesis conditions. The extent of purity of zeolite Y depends on the surface areas of aluminosilicate precursors. A novel approach to zeolite Y synthesis was employed for the preparation of the pure nanosized zeolite Y. This was achieved by applying the method of impregnation of precipitated silica. This novel method of impregnation for zeolite Y preparation allows eliminating the vigorous agitation step required for the preparation of a homogeneous silica solution, thereby simplifying the synthesis of zeolite Y in one single vessel. In case of the synthesis of nanosized zeolite Y, the effect of varying the organic templates on the formation of nanosized particles of zeolite Y was investigated, while all other reaction parameters were

  18. Cytomatrix synthesis in MDCK epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.J.; Low, R.B.; Woodcock-Mitchell, J.L. (Univ. of Vermont, Burlington (USA))

    1990-06-01

    Detailed information regarding the synthesis rates of individual protein components is important in understanding the assembly and dynamics of the cytoskeletal matrix of eukaryotic cells. As an approach to this topic, the dual isotope technique of Clark and Zak, was employed to measure fractional synthesis rates (FSRs) in growing and quiescent cultures of MDCK epithelial cells. Cell protein was labeled to equilibrium with (14C)leucine over several days and then pulse-labeled for 4 hours with (3H)leucine. FSRs (as percent per hour) were calculated from the 3H/14C ratio of cell extracts or individual proteins separated by two-dimensional polyacrylamide gel electrophoresis and the 3H/14C ratio of free leucine in the medium. Synthesis of total cell protein rose from approximately 1.4%/hour in quiescent cells to 3.5%/hour in the growing cultures. The latter rate was sufficient to account for the rate of protein accumulation and a low level of turnover in the growing cultures. The FSR of the buffered-Triton soluble extract was higher and the cytoskeletal FSR significantly lower than that for total protein in quiescent monolayers. This difference, however, was not observed in growing cultures. A distinct pattern of differences was seen in the FSRs of individual cytoskeletal proteins in the quiescent cultures. Vimentin synthesis was significantly lower than that of the keratins and the keratin FSRs were not obviously matched in pairwise fashion. Unexpectedly, the FSRs of alpha- and beta-tubulin diverged in quiescent cells with alpha-tubulin turnover exceeding beta-tubulin. Likewise, components of the microfilament lattice showed unequal fractional synthesis rates, myosin and alpha-actinin being faster than actin. In addition, the FSR for globular actin exceeded that of the cytoskeletal associated form.

  19. Software Synthesis for High Productivity Exascale Computing

    Energy Technology Data Exchange (ETDEWEB)

    Bodik, Rastislav [Univ. of Washington, Seattle, WA (United States)

    2010-09-01

    Over the three years of our project, we accomplished three key milestones: We demonstrated how ideas from generative programming and software synthesis can help support the development of bulk-synchronous distributed memory kernels. These ideas are realized in a new language called MSL, a C-like language that combines synthesis features with high level notations for array manipulation and bulk-synchronous parallelism to simplify the semantic analysis required for synthesis. We also demonstrated that these high level notations map easily to low level C code and show that the performance of this generated code matches that of handwritten Fortran. Second, we introduced the idea of solver-aided domain-specific languages (SDSLs), which are an emerging class of computer-aided programming systems. SDSLs ease the construction of programs by automating tasks such as verification, debugging, synthesis, and non-deterministic execution. SDSLs are implemented by translating the DSL program into logical constraints. Next, we developed a symbolic virtual machine called Rosette, which simplifies the construction of such SDSLs and their compilers. We have used Rosette to build SynthCL, a subset of OpenCL that supports synthesis. Third, we developed novel numeric algorithms that move as little data as possible, either between levels of a memory hierarchy or between parallel processors over a network. We achieved progress in three aspects of this problem. First we determined lower bounds on communication. Second, we compared these lower bounds to widely used versions of these algorithms, and noted that these widely used algorithms usually communicate asymptotically more than is necessary. Third, we identified or invented new algorithms for most linear algebra problems that do attain these lower bounds, and demonstrated large speed-ups in theory and practice.

  20. Fatty acid synthesis by spinach chloroplasts, 2

    International Nuclear Information System (INIS)

    Yamada, Mitsuhiro; Nakamura, Yasunori

    1975-01-01

    By incorporation of 3 H 2 O into the fatty acid chain in the presence of unlabelled precursor, we showed that fatty acids are synthesized from PGA, PEP and pyruvate by intact spinach chloroplasts in the light. 13 C-tracer experiments confirmed that 1-C of pyruvate is decarboxylated and 2-C is incorporated into fatty acids by the chloroplasts. The patterns of fatty acids synthesized from PGA and pyruvate were the same as that from acetate. The highest rate of fatty acid synthesis was reached at the physiological concentration of PGA (3 mM) and pyruvate (1 mM). These results indicate the operation of the following path in the chloroplasts in light: PGA→PEP→pyruvate→acetylCoA→fatty acids. Since citrate and OAA were much less active and malate and glyoxylate were inert as precursors for fatty acid synthesis, PEP or pyruvate carboxylation, citrate lyase reaction and malate synthetase reaction are not involved in the formation of acetylCoA and fatty acids. Since pyruvate was much more effective as a substrate for fatty acid synthesis than lactate, acetaldehyde or acetate, direct decarboxylation path is considered to be the primary path from pyruvate to acetylCoA. The insignificant effect of chloroplast-washing on fatty acid synthesis from PGA and pyruvate indicates that the glycolytic path from PGA to pyruvate is associated with the chloroplasts. Since pyruvate was more effectively incorporated into fatty acids than acetylCoA, it is unlikely that pyruvate decarboxylation to acetylCoA is due to mitochondria contaminating the chloroplast preparation. On the basis of measurements of 3 H 2 O incorporation in the light and dark, the activity of fatty acid synthesis in spincah leaves appears to be shared by the activities in chloroplasts (87%) and other organelles (13%). (author)